EP1035950A1

EP1035950A1 - Device for driving a fastening element into a base and use of said device

Info

Publication number: EP1035950A1
Application number: EP98962387A
Authority: EP
Inventors: Achim Weihrauch
Original assignee: Kellner Gerd
Current assignee: Kellner Gerd
Priority date: 1997-12-04
Filing date: 1998-11-23
Publication date: 2000-09-20
Anticipated expiration: 2018-11-23
Also published as: HUP0102013A2; PT1035950E; CZ20002069A3; DE19800847A1; DE59802676D1; CN1283145A; HUP0102013A3; AU732265B2; CZ296853B6; HK1031354A1; WO1999029472A1; CA2312353C; US6457624B1; JP2001525262A; ES2170546T3; CA2312353A1; AU1756999A; ATE211958T1; DK1035950T3; EP1035950B1

Abstract

The invention relates to a device for driving fastening elements into a base for the purpose of fastening structural components. Said device has a working piston whose range of acceleration and deceleration can be adapted to different conditions whilst maintaining an optimal driving depth (31) and minimal piston length (32). This applies to mechanical, pyrothechnical, pneumatic, electromagnetic and electrothermal working piston drive mechanisms. These devices can be configured for manual use or for production robots, and are characterised mainly in that the working stroke is limited by a piston sleeve (35) which is connected to the piston plate (11), a land (39) which is connected to a ring element (38) or a combination of the two. A chamber is therefore formed on the piston plate side (48a) and the ring side (48b). Said chamber accommodates an e.g. mechanical return device (8) which is subjected to its own load only during the driving-in and gauging processes. The remaining piston energy is cushioned by a buffer (30). The modular configuration of the piston plate (11) and the piston shaft (10) means that the components can be optimised independently in terms of shape and material. The piston mass can be varied considerably. The device can be configured with any degree of rigidity and can be adapted to different fastening elements, bases and driving-in conditions.

Description

description

Device for placing a fastening element in a setting surface and using the device

The invention relates to a device for placing a fastening element in a setting surface according to the preamble of claim 1 and to the use of this device for fastening components to the setting surface with the aid of the fastening elements according to the preamble of claim 26

Numerous devices of this type, which are used to fasten a wide variety of components on setting bases of various types by means of fastening elements such as bolts, rivets, nails, are known. Depending on the design, the devices work in individual operation, semi-automatically or fully automatically. In principle, all devices are constructed identically A working piston is accelerated mechanically or under the pressure of a medium, for example under pyrotechnically generated gas pressure. This working piston in turn drives the actual fastening element. The devices also point Additional devices which fulfill certain additional functions or which serve to ensure the safety of their function or handling. An example of such an additional function is the resetting of the working piston after a setting process. Further additional devices serve, for example, to feed the fastening elements and to dampen or buffer them. seteile functionally perform secondary tasks

The object of the present invention is then seen

to create a device of the type mentioned at the outset, which is designed in such a way that it not only optimally fulfills the basic function but also various additional functions, and which is designed in such a way that numerous vanants are possible in the design and use of the device, and - one Suggest using this device

This object is achieved by the features of the characterizing part of patent claim 1 and of patent claim 26. Advantageous further developments and preferred exemplary embodiments of the device according to the invention are defined by the patent claims dependent on patent claim 1

The principle of the invention and the advantages achieved with it are described in detail below with the aid of examples and with reference to the drawing, not only the invention but also basic theories of setting technology and the prior art are explained. It shows

Fig. 1 shows a conventional device with its essential

Components, in a simplified, schematic representation,

2 shows another conventional device,

3A em device according to the invention, with the working piston in its starting position, ie before the working stroke, 3B shows the device shown in FIG. 3A, with the working piston in its end position, that is to say after the working stroke and before the return,

4A and 4B two devices with vanants of the stroke limitation according to the invention,

5A to 5F several devices with different embodiments of mechanical reset points,

6 shows a device with a piston plate designed as a step plate,

7A and 7B devices with reinforcements of the piston skirt in the area of the attachment of the piston plate,

8 shows a vanante of the device shown in FIG. 3A, with a working piston in a special embodiment,

9 shows a further variant of the device shown in FIG. 3A, with a working piston in a further, special embodiment,

10A to 10E devices with design options for changing the working stroke of the working piston,

11 A to 11 C three devices with exemplary embodiments for the arrangement of the return spring according to FIG. 5E,

12A and 12B two exemplary embodiments of devices with working pistons with damping, 13A to 13B two devices with tandem systems in which the working piston contains a secondary piston, and

14A and 14B devices with electromagnetic Antneb of the piston

At this point, it should be pointed out that components arranged in the various devices, which fulfill corresponding functions, are sometimes provided with different reference symbols depending on the device, and that not all components are provided with reference symbols for each device

1 shows the essential components of a conventional device. A working piston 3 is smeared into a housing 1 by means of an auxiliary medium 2. This working piston 3 drives a fastening element 4 to be set, for example a nail or bolt, into a setting base 6, specifically by or for a component 5 to be fastened, which is to be fastened on the setting base 6 by means of the fastening element 4. The working piston 3 moves in a piston guide sleeve 7. The working piston 3 is reset by means of a return device 8. The working piston 3 strikes a damping device 9 , which also serves as a stroke limiter. The working piston 3 has a piston shaft 10 and a piston plate 11. The sealing against a medium-loaded space 2 behind the piston plate 11 is carried out by means of a sealing element 12. The fastening element 4 to be set essentially consists of a bolt shaft 4a, a Bolt base 14 and a guide area 15. An additional device serves as a pin magazine 13. The piston skirt 10 and the fastening element 4 run in a shaft guide sleeve 16. The control takes place via a control device 17. A housing 18 forms a secondary component. A damping element 19 is located between the piston guide sleeve 7 and a mounting sleeve 20.

Performance-determining properties of such devices are the working piston output and the piston working path or working piston stroke. mär determined by the mass of the working piston m _κ and the piston speed V _K. The piston energy E _κ and the piston pulse I _κ are transmitted to the fastening element and to the housing when the working piston is accelerating and during the setting process. The piston energy E _κ and the piston pulse I _{κ are} calculated as follows:

E _κ = m _κ II v _κ ²

I _κ = m _κ vκ

The properties of the fastener - always sufficient dimensional stability when

Assuming the setting process - can be described or defined by the desired depth of penetration into the setting surface and by the type of setting channel. If one assumes that the kinetic energy E required to displace a volume element V in the subsurface remains constant in the first approximation - this statement has become widespread in so-called Cranz's model law in end ballistics - the relationship E / V = k where k is a constant, the most important criteria for the setting power and from this fundamental considerations for the devices. This is explained in the following using a comparatively simple example.

Given a given conception of the bolt, a certain depth of insertion is specified. For example, the kinetic energy of the working piston required for this can be estimated according to Richter's theory, which was further developed at the ISL. This theory was developed for penetrating stane cores of different tip or ogive shape and takes into account not only the material strength but also inertia and frictional forces; The theory originally set up for homogeneous targets was also extended to targets with a multilayer arrangement, for which reference is made to the ISL-Beήcht R 120/83 * a tank formula for non-deformable ogive projectiles and their extension to deformable projectiles * by K. Hoog. The theory deals with the analytical treatment of end ballistic questions in non-deformable penetrators. With a setting depth of 10 mm in a setting base made of structural steel and a bolt with a diameter of 4 mm and with a tip in the form of an ogive, if this ogive is slim, the following relationship applies:

E / V * 2

REPLACEMENT BI ATT (RULE 26) An energy of 0.25 kJ is therefore required to set the bolt. This energy can be provided, for example, by a device with a mass of bolts and working pistons of 0J kg at a speed of 72 m / s, or with twice the mass of bolts and working pistons of 0.2 kg at a speed of about 50 m / s. According to Richter's theory, with constant energy, the depth power increases with decreasing impact speed, namely by about 20% when the impact speed decreases from 72 m / s to 50 m / s according to the example mentioned above; As a result of the lower energy requirement, the latter should not be 50 ms but only about 40 m / s for the intended setting depth at a lower impact speed. These relationships must be taken into account when designing the devices with regard to the mass of the working piston and the speed. The corresponding considerations are also important because in connection with a possible kink, which will be discussed below, it can be shown that a critical, device-specific speed must not be exceeded or that the design of the device pushes the limits for the dynamic sizes.

In connection with the question of an advantageous piston speed for a given piston energy, the interaction between the working piston and the surrounding device should also be considered. The following considerations serve this purpose: With a mass ratio of piston to housing of 1 to 10 or a piston mass of 0.1 kg and a housing mass of 1 kg and at a piston speed of 30 m / s, the fact that pistons and Housing a return speed of the housing after acceleration of the working piston of 3 m / s. The kinetic energy of the piston is 45 j, the kinetic energy of the housing is 4.5 J, and the sum of the kinetic energies is therefore 49.5 J. The ratio of the kinetic energy of the piston to the total kinetic energy is 49/4, 5 or almost 11. If the piston mass is now increased to 0.2 kg and at the same time the housing mass is reduced to 0.9 kg so that the total mass does not change, the result is if the total energy is to remain the same and taking into account that the impulses of the piston and the housing must be the same, a piston speed of 20 m / s and a return speed of the housing of 4.5 m / s. The kinetic energy of the cob is 40.5 J and that of the housing 9 J. This now corresponds to a ratio the kinetic energy of the piston to the total kinetic energy of 49.5 / 9 or about 5.5. This means that when the mass of the working piston is doubled from 0.1 kg to 0.2 kg, the energy transmitted to the housing as the recoil energy is increased doubled, namely from about 10% of the total energy to about 20% of the total energy

The above energy considerations do not support a high piston speed, in contrast to Richter's theory explained above, according to which a narrow piston speed is preferable. In practice, a design-related change in the piston mass leads to significantly smaller mass differences between the working piston and To calculate the housing than with the mass differences mentioned above, so that the ratio of the energies of the working piston and housing can only be 3 to 5% less favorable if the piston speed decreases.Thus, the final ballistic arguments, according to Richter's Theone, favor a lower piston speed In addition, there are the considerations of buckling and the permissible material stresses, both of which also limit the piston speed. These considerations also show that the mass and energy distribution have an impact on the shock load on the housing can be called

The treatment of device- and material-specific questions and the corresponding calculations can generally be best carried out for substances whose mechanical-dynamic behavior can be described, for example, by means of analytical relationships. Much more complex and accordingly, setting processes are more difficult to treat or to calculate to which the fastening elements or bolts are placed in inhomogeneous and non-metallic substrates such as concrete, in particular reinforced concrete, concrete with stone inclusions, porous and brittle or hard materials, as well as multi-layer structures. Another technically demanding problem when installing fastening elements or bolts is then given , if the component to be fastened, for example cladding, insulation mats or metal plates, and the setting substrate differ greatly in structure and mechanical properties From the above explanation of the problems, it is inevitable that the essential components of the devices, namely the working piston unit, must be designed and implemented in such a way that they correspond to the different operating conditions occurring. Furthermore, the working piston unit must be changed without changing the concept or by means of relative means Simple modification of individual components can be optimally adapted to various requirements. The above requirements are further emphasized by the fact that changing safety regulations must be observed

Setting performance, reliable function with different material pairings and pre-determined setting depth to be observed are, in connection with the ability of the individual device components to vanish, are decisive prerequisites for a technically optimal solution

A particular problem with the devices known hitherto consists in the required braking of the working piston. When dealing with this problem, a distinction must be made between setting processes in which fastening elements are actually used and setting processes in which no fastening elements are set, the latter being feared by the device manufacturers and are referred to as 'empty shots' Such empty shots occur, for example, when there is no attachable fastening element when the device is triggered, or when the intended setting surface is a cavity (e.g. gap) or has a cavity As is known, a certain part of the setting process becomes Transfer the piston energy or the piston pulse to the fastening element and the setting surface. Braking the working piston and maintaining a certain setting depth play a role here. In the event of empty shots, the entire piston energy in the device itself must be compensated usually leads to peak loads in the affected components of the device and requires corresponding damping devices or the provision of piston brakes

These damping problems are of great importance for manually operated devices, their solution requires a technically balanced interplay of the individual components of the device with the aim that only unavoidable external forces occur or the load profile is optimized For devices that are not intended for manual operation , this requirement is withdrawn. cause that the tension in some components of the devices increases when there is no need for damping or elements, which must be taken into account when designing them

The present invention takes into account not only the theoretical considerations mentioned above but also all aspects relevant in connection with the implementation of the devices.This means that the new device not only satisfies all the technical requirements relating to this area in terms of the design area of the working piston, but also Allowing a maximum possible vanation of optional training vanants in every relationship. For example, the new device can be optimized with regard to the anti-fog, which can be mechanical, pyrotechnical, pneumatic or electronic. Furthermore, the new device can be manufactured in a previously unrealized minimal device construction length that is practically only is determined by the desired setting depth Furthermore, the new device has a constructive concept that allows a wide variety of device designs, it can be used as a manually operated device as well as a device for extreme requirements or n are manufactured according to very specific specifications, examples include use as a heavy-duty device, for example for setting larger fastening elements in steel construction or for use in production robots, but also in particularly light or miniaturized versions

Another requirement that is very important for the design of the devices is their robustness in use

It is also desirable that perfectly functioning devices are manufactured without having to look back at highly specialized materials. These are mostly in very limited areas of application with a corresponding margin of safety. are cost-intensive, often difficult to dispose of over a long period of time, difficult to process and, in combination with other materials, also often problematic A sophisticated, universally applicable and at the same time inexpensive solution means that the individual components require a minimum of mechanical processing and that complex material treatments and surface processing are largely avoided In the case of automatically operating devices, the return of the working piston must be ensured after each setting process. A number of processes are known for this, which extend from the exhaust gas return pipe (Hilti) to metallic spring elements and return springs made of elastomer material (Wurth). Systems with exhaust piston return technically comparatively complex and limited in their area of application and in their functional reliability. For example, they require an accelerating medium with gas generation. Furthermore, the resetting process in the event of malfunctions or in border areas is difficult to ensure. In the case of metallic and elastomeric return springs, it must be ensured that the stroke do not withdraw too much energy and thus adversely affect the setting power in relation to the energy used. Furthermore, metal springs must not be subjected to excessive accelerations, since the mechanical stress is There are limits to the properties of the materials. Elastomers or rubber-like restoring elements with buffer functions also influence the overall length of a system and require a relatively large volume of functions. Furthermore, like emissions with exhaust gas recirculation, they also limit the design scope

Fundamentally, restoring devices or restoring elements must be more functional, should have a small mass to avoid inertial forces and negative influences on the setting process, should only be mechanically loaded by themselves, should only apply the relatively small restoring forces, require a small construction volume and are technical Changes - e.g. when modifying individual elements - can be easily adapted

For the device type to which the known device shown in FIG. 1 belongs, a number of possibilities for damping or limiting the travel of the working piston 3 and also for steaming the entire device are known. The piston steaming takes place in previously known solutions, for example via a Friction clamping between the damping and stroke limiting device 9 and the piston skirt 10 according to Hilti or by axial buffering, for example by means of a cone solution according to Kellner Wurth, the energy or the momentum of the working piston 3 via the return spring 8 on the damping or Stroke limitation 9 transferred This restricts the design of the return spring 8 significantly and also leads to impermissible stresses in the damping and stroke limiting device 9 and in the piston skirt 10 in the event of a power surplus in the working piston, as occurs, for example, in the case of empty shots when the piston rod 10 is clamped by means of the damping - and stroke limiting device 9 there is no defined braking. Furthermore, such friction-related processes are fundamentally not the same or are subject to serious changes in the course of the period of use and, for example, also due to the surface condition

Fig. 2 goes a little closer to the solution of the damping problem according to Kellner / Wurth, which corresponds to the current state of the art. Essential elements in this device are the travel limitation of the working piston 21 by means of a piston rod cone 22 and an elastomeric return spring 27. To brake the Working piston 21 places the piston rod cone 22 in a conical ring-like element 25. This conical ring-like element 25 is buffered by a buffer element 26. The opening angle 28a or 28b determines the radial and axial components of the piston energy. The area of the piston rod cone 22 results from the ratio of the diameters of the rear piston rod part 23 and the front piston rod part 24. It is obvious that the conical surface which is decisive for the material load cannot be changed or enlarged arbitrarily. On the one hand, it is positioned near the axis, so a change in radius has an effect the F laugh relatively small from The smallest possible diameter of the front piston rod part 24 is determined by the requirements when setting the fastening element. The diameter of the rear piston rod part 23 cannot be increased arbitrarily, since otherwise the remaining working volume for a return element 27 would be too small. This concept results inevitably that the piston sleeve is relatively long

If larger opening angles 28a or 28b are selected, the conical surface of the piston rod cone 22 becomes smaller, which has the consequence that the stress on the material quickly exceeds the permissible stresses. At small opening angles 28a or 28b, the radial component of the piston energy Dies increases results in high compressive stresses in the piston rod cone 22. The component in the conical ring-like element 25 leads to high tensile stresses there. All in all, with such a solution, it is only possible to adapt or optimize the decisive parameters to a limited extent if the device is intended to have wider working areas.

Basically, resetting the working piston by means of an elastic element such as a rubber spring is a technically interesting solution. However, such a solution has two disadvantages. First, this results in long piston rods 21, because behind the piston rod cone 22, because of the function of the restoring element 27, there must still be a rear piston rod part 23 corresponding to the required piston travel; however, the working piston is the most critical element of the device with regard to stress; the length of the piston rod is therefore always a decisive criterion. Secondly, the working piston is a critical element even when there is a high excess of energy or when there are no shots, in particular the point at the transition to the front, thinner piston rod part 24. These points, which are particularly critical in the case of dynamic stress, make it necessary to use high-quality materials for the entire working piston use, so that the working piston forms a very demanding and therefore expensive component. Corresponding considerations also apply to the conical ring-like element 25. In summary, for this solution it is true that the design of the working piston with a piston rod cone in connection with the conical ring-like element makes an optimal design difficult and a variation of the device design only permits to a limited extent.

It is particularly important to design the working piston in such a way that it has sufficient security against buckling, since very small axis deviations of the working piston lead to failure of the device due to the dynamics of the setting process. In the case of the dynamic loading of slim bodies, a distinction must be made between static and dynamic buckling problems with regard to security against buckling. For static buckling problems, a corresponding buckling load can be calculated according to Euler. Dynamic buckling problems occur with components that are primarily highly dynamic and impact-like and lead to so-called dynamic-plastic buckling. For this we refer to the ZS report RT 13/70 with the study examinations for plastic buckling of slim metal cylinders when hitting metallic targets * by G. Weihrauch et al. In contrast to static or Euler buckling, the length or slenderness of the body is irrelevant for dynamic plastic buckling, since the dynamic buckling process occurs between the butt surface and the spreading plastic front play According to experimental investigations, slender, high-strength bodies at impact speeds at hard targets with speeds of up to about 100 m / s can be assumed that - provided the plasticity limit is not exceeded - buckling problems can be treated according to Euler

When accelerating fasteners there are two areas in the device where kinking can occur, firstly the area between the piston plate and the front guide in the setting head, and secondly the area between the front guide in the setting head and the fastening element or bolt or nail

Furthermore, buckling also occurs in the fastener itself, i.e. in the bolt or nail. The above-mentioned buckling in the area between the front guide in the setting head and the fastening element is very complex, since the free part of the leading bolt shaft becomes continuously longer when the bolt is being inserted, which means the buckling mentioned therefore be considered in particular when hitting the fastener and during the setting process together with this fastener

By means of analytical methods, therefore, only a few basic estimates can be made; more precise considerations are necessary, since lateral movements are no longer axis-symmetrical arrangements for carrying out 3-dimensional FE calculations

When estimating the buckling load according to Euler, it is assumed as a first approximation that the buckling problems mentioned above under the first and second are a mixture between two buckling types, namely, on the one hand, a buckling with free, axially guided rod ends and on the other hand, around a kink with a clamped and a freely movable rod end, so that the The free buckling length mentioned is between 1 and 2. The stress occurring in the components considered as a bar is calculated from σ = E π / 4 (r / L) ² where E is the modulus of elasticity, r is the radius, and L is the length of the bar. For a ratio from length to diameter of 10 or from corresponding length to radius of 20 there is, for example, a limit of approximately 1300 N / mm ² for the occurrence of static stresses

The tension induced when the working piston strikes the fastening element or the bolt is generally determined according to the following equation σ = v (E p) ', where E is the modulus of elasticity, v is the impact speed and p is the density The limit stress is reached for a certain material. This is around 35 m / s for the selected example. Consider that materials with higher strengths, for example 1500 N / mm ² , are used for the working piston and that with dynamic processes with higher ones Limit stresses can be calculated, whereby in the present case the limit stresses can be higher by a factor of 1.5, this results in a speed of approximately 60 m / s. At higher speeds of the front piston shaft or the fastening element, the elastic limit is exceeded and the limit is released local flow in addition, buckling according to Euler is to be expected

The above estimate is of fundamental importance for the design of the devices. In particular, it underlines that the free length of the working piston should be kept as short as possible.This is important in connection with a central pushing of the pin / nail. In addition, the speed should be avoided in order to avoid artificial tension selected too high This means that the required setting power can be set by vanating other agents, e.g. via the piston mass

3A and 3B schematically show the design of the area of the working piston for a device for setting fastening elements according to the invention. The new device designed in this way combines a number of advantages, with which not only the problems set out above are largely solved, but also a high degree of possibilities for structurally diverse variants is guaranteed. The main features of this concept are shown in FIG. 3A. Then, to limit the working stroke 31, a stroke limitation device acting on the piston plate 11 is provided This is designed such that a stop surface is arranged on the piston plate 11, which comes into contact with a counter surface arranged on the cylinder in the end position of the piston, ie after the working stroke

The stop surface can be formed by the front end surface 37 of a piston sleeve 35. The counter surface 43 can be formed by the end surface of an intercept sleeve 38 connected to the piston plate 11. It is possible to use only the piston sleeve 35, only the ring element 39 to be provided with the interception sleeve 38 or a combination of piston sleeve 35 and ring element 39 / interception sleeve 38. The interception sleeve can also be designed in the form of a web

This arrangement forms a space which serves as a spring chamber 44, through which the return device 8 can be inserted.This return position 8 is only used during the setting process and during the instruction shot by its own load.The impact transmitted to the piston sleeve 35 or the ring element 38 acts via a Tragemng 29, which in turn can be shock-buffered again if necessary against the housing by means of a damping element

The advantages of the new device are listed below, without claiming to be complete

- The length of the piston skirt 34 becomes minimal

- The construction can be adapted to the different reset options. Because of the spring chamber 44, which can be varied within wide limits, only all mechanical reset devices, for example metal springs or elastomeric systems, are possible, but also other reset devices, for example with a driving medium, especially gas - The concept is basically suitable for various types of working pistons, in particular for an electromagnetic or electrothermal device

- The piston speed can be changed within wide limits with constant powder energy via the vanation of the piston mass

- The dimensioning can be adapted to the materials used. Connections, for example due to changing performance requirements, are easily possible in terms of behavior

- The piston skirt 34 can be made as stiff as desired - The piston plate 11 together with the piston sleeve 35 is an extremely rigid component

- Piston guide and piston seal in the area of the piston plate 11 can advantageously be carried out

- By changing the diameter of the piston skirt 10 or the mass of the working piston by changing the dimensions and or the choice of materials with different densities, the performance of the device can be improved while the Antneb remains the same, which is a particularly important point in terms of technology the details of the structural design are adapted to the final ballistic specifications of the setting process - piston skirt 10 or 34 and piston plate 11 can be separate components. This allows separate optimization for these two components, for example with regard to surface processing, material, mass and dimensions Dental design of the shaft can, for example, be used for materials which are subjected to special treatments to achieve certain mechanical properties, for example high breaking strength, which are only possible with dental bodies, for example strain hardening rchhammern Among other things, nitrogen-alloyed steels are available in the dimensions in question here with strengths of up to close to 3000 N / mm ²

- Different piston shafts can be combined with various piston plates

Multi-gradient materials can be used in the highly stressed areas, which are denoted by circles in FIG. 3B. These are materials in which, for example, the mechanical properties, for example the hardness, changes in one direction between predetermined limit values, for example on the finished body in the axial or radial direction, but generally not in two orthogonal directions

- The concept can be optimally adapted to different requirements for setting depth and setting performance. Because of the short piston rods and their high rigidity, not only very large setting depths can be realized, but also very high setting forces can be handled

- Only a few surfaces can be processed with high quality. These are particularly easy to carry out. - Due to the above-mentioned vanation possibilities in the area of the working piston, the device can also be optimized with regard to external forces, for example with regard to the shape and size of the load when setting

- The concept optimally does justice to the circumstances, since the required restoring forces are relatively low. This follows solely from the piston dimensions, which, for example, were allowed to move between 50 and 300 grams for devices for manual operation. The reset device must therefore be primarily one Ensure that the piston can be reset sufficiently quickly and securely and that the piston is fixed in the starting position. The range of applications can be expanded according to the possibilities introduced by the invention to include miniaturized devices with dynamically moving masses in the gram range, for example through the use of high-strength non-metallic components dynamically stressed components up to heavy or massive arrangements for special requirements, for example when very high impact or hammer forces are required - the piston skirt can be provided with a hole, for example to accommodate an egg ner signal line or an additional mechanical device Here, for example, it can be considered to trigger a further function via an inner rod or after the actual setting process. A hollow piston can also accommodate an inner or secondary piston, as shown in FIG. 11

3B, the working piston is shown in its foremost position. The abutment surface of the piston sleeve 35 and the counter surface of the interception sleeve 38 abut one another, so that the piston sleeve 35 together with the ring element 39 of the interception sleeve 38 forms the spring chamber 44 which is closed here and which accommodates the resetting device, for example a resetting spring or other resetting elements.

Calculations using simulation calculations, which can be carried out 2-dimensionally for rotationally symmetric parts and also 3-dimensionally for estimating the dynamic load for asymmetrical parts, and which were also carried out at the ISL at the suggestion of the inventor for the sake of orientation, have not only the above considerations for buckling and too confirms the material stress with regard to the occurring speeds, but also shows that during the setting process itself, i.e. when the working piston strikes the fastener to be set and when driving it forward, as well as when braking and especially during the teaching shot, sudden loads occur that affect the dynamic behavior determine the components involved and also the occurring or permissible material stresses. In addition, locally high tensions can occur, for example due to the superimposition of shocks, until the yield point is exceeded, which can be avoided by means of design measures. It is an advantage of the new device that such measures are particularly simple due to the possibility of varying the individual components.

As already mentioned, the dynamically highly loaded zones are shown circled in FIG. 3B. It is about:

- The end face of the working piston 45a driving the fastening element or the bolt; - The stop and counter surfaces meeting in area 45b;

- Zone 45c, which is particularly stressed by the inertia of piston skirt 34 during the training shot;

- The transition area 45d between piston skirt 34 and piston plate 11;

- The transition region 45e between the piston plate 11 and the piston sleeve 35; the transition zone 45f between the front sleeve surface 41 and the sleeve buffer 30 or between the sleeve buffer and the ring 29. FIGS. 4A and 4B show a zone 48A or chamber 48B containing the reset device 8, which is indicated by an arrow, in two borderline cases. According to FIG. 4A, zone 48a is formed solely by a long piston sleeve 35a; according to FIG. 4B, chamber 48b is created solely by a long catch sleeve 39a. The counter ring 50 becomes correspondingly flat in the first case according to FIG. 4A and the piston plate 51 in the second case according to FIG. 4B.

4A also shows examples of the supply of a working medium, for example a working gas. In addition to a conventional, central feed 46, the feed can also take place via passages 47a distributed over the circumference or via a plurality of bores 47b.

Also shown in FIG. 4A are examples of various seals in the area of the working piston with respect to the media space, which are necessary when using fluid drive means. This can be, for example, an annular seal 49a or a labyrinth seal 49b, which are shown as an example in the upper half of FIG. 4A; long piston sleeves are advantageously guided only at their ends, as shown in the lower half of Fig. 4A; a special sealing element can be dispensed with due to the cavity 49c.

As has already been mentioned several times, particular attention must be paid to the limitation of the stroke 31 of the working piston shown in FIG. 3A with a high setting power and the damping in the case of an empty shot. With regard to damping, a distinction must be made between damping for the moving components and damping for the other components, such as the housing.

The moving components can be damped

- Via the piston sleeve 38, which transfers the residual energy of the working piston; by means of damping devices in the piston plate 11 ;.

- About the elasticity of the materials of the interception sleeve 38 and the piston sleeve 35;

- partly via the reset device 8;

- By placing the surface 37 of the piston sleeve 35 directly on the ring 29 or directly on the inner surface of the piston sleeve 7 or on the mounting sleeve 20.

In addition, damping elements can be provided by vulcanization both in the area of the interception sleeve 38 and the piston plate 11 or the piston sleeve 35.

The damping in the area of the housing surrounding the work area can be influenced

- by a certain ratio between the moving mass to be braked and the resting mass;

- By special damping devices on the housing, preferably elastomeric elements;

The 'degree of filling' can e.g. due to the special dynamic properties of rubber in a rubber damper in combination with the damping element, any damping function can be set through material and shape, up to 'shock-resistant' behavior when fully filled.

A technically particularly demanding variant that is also interesting due to its simplicity is the case that no special damping measures are provided. The forces that occur must then be absorbed solely through design measures and material properties. Due to the modular structure and the special features of the invention, the use of materials with extreme properties in terms of design, density and resilience is possible. This is illustrated by the following examples: - The interception sleeve 38 consists entirely or partially of heavy or hard metal, ceramic, light metal or fiber-reinforced materials according to the properties hard, heavy, light, steaming.

the piston skirt 34 is made of hard metal or ceramic, possibly only in the area on the bolt side, corresponding to the properties hard, light,

the piston plate 11 contains elements made of glass fiber-reinforced materials, for example, according to the properties light, steaming,

a vulcanization layer is introduced into the piston plate 11,

- The piston shaft 34 is mounted in the piston plate 11 with shock absorption, - The interception sleeve 38, the piston shaft 34 or the piston plate 11 with the piston sleeve 35 consists of a multi-gradient material

In particular with larger diameters of both the moving and the still parts, it can be advantageous to use materials of low density such as light metal, fiber-reinforced plastics or malleable ceramics. Constructive solutions are also conceivable in which the bodies are made hollow and, for example, with foamed ones if necessary Metals are combined as a link of a lightweight construction with high rigidity

Due to the possible two-part design of piston skirt 34 and piston plate 11, piston plate 11 can be produced using a casting technique. This is particularly advantageous in the case of non-rotationally symmetrical shapes or a more complex design of piston plate 11 and piston sleeve 35 in connection with piston shaft 34. The connection between piston plate 11 and piston shaft 34 can be detachable or non-detachable and can be implemented, for example, by means of threads, soldering, gluing, vulcanizing, friction welding, interface sintering, clamping or shrinking

5A to 5E show examples of devices with mechanical reset devices or reset elements

5A, the restoring elements are a simple rubber sleeve or a hose 52, consisting, for example, of a homogeneous elastomeric material or of foamed material. Appropriate guides 52a must be provided for the piston strokes. Such simple arrangements are only suitable for relatively short working strokes 31. It must also be ensured, for example by the design of the spring chamber, that the movement of the piston sleeve 35 takes place undisturbed. A thin sleeve 52b can contribute to this.

5B, the restoring element consists either of a system with rubber hollow chambers 53a, as shown in the upper half of FIG. 5B, or of a bellows-like element 53b, as shown in the lower half of FIG. 5B.

FIG. 5C contains a reset device corresponding to that of FIG. 2, but without the rubber spring 54a having to apply braking effects or a force to limit the stroke. The rings or disks 54b serve here as fixing elements.

5D, the reset device is a metal spiral spring 55a.

5E, the resetting device is formed by a metal spring with a square cross section / flat wire 55b. The metal springs are fixed by the surfaces 56a, 56b and 56c.

An example of multi-stage or multi-part reset devices is shown in FIG. 5F. It is a combination of an element 57a on the head or sleeve side, an element 57b on the piston plate side and a separating element 57c. This element can also serve as a buffer between the end faces 37 and 43.

6 shows, as an example of a special embodiment of the piston plate, a step plate 60, which is composed of a front piston plate part 61 and a rear piston plate part 62. The piston chamber sleeve or piston guide sleeve 64 for receiving this step plate 60 is adapted accordingly. This embodiment is advantageous if, for example, a load change is to be achieved during the working stroke. The outer region of the front piston plate part 61 then expediently takes over the tasks of the guide and the media seal 63. In this way, it is possible in principle between the driven piston part and the

ERSATZBUVTT (RULE 26) guided or steamed or reset part, a structural separation can be carried out. The rear part of the piston chamber sleeve or piston guide sleeve 64 is particularly suitable here, for example, to accommodate an adjustment device 64a for changing the output chamber volume

FIGS. 7A and 7B show devices with possible reinforcements of the piston skirt in the area of the piston plate. This concept is suitable for absorbing the increased dynamic stresses occurring in the transition area between the piston plate and piston skirt, which also includes FIG. 3B the zones 45c, 45d and 45e shown there

7A, the diameter of the shaft 66 increases towards the rear. The rear piston shaft part 66a is connected, for example, by means of a thread 66b to the correspondingly designed piston plate 69. The piston plate 69 and the piston shaft 66 or the rear piston shaft part 66a can be designed in this way That the rear piston shaft part 66a extends through the piston plate 69 or is only inserted into the piston plate 69. The piston shaft part 66a which is continuous in this example contains a bore 67 on the side of the anti-abrasive fluid for media guidance. The volume thereof can be changed by a screwed-in element 68

7B shows a working piston with a cylindrical piston shaft 70 inserted into the piston plate 71 and mounted in a corresponding piston shaft holder 71a in the piston plate 71. The connection between the piston shaft 70 and the piston shaft holder 71a can be made, for example, by means of threads, soldering or mounting. shrinking take place In this example, the piston plate 71 has a recess 72, for example in the form of a rotation for media guidance or for changing the original media volume

Fig. 8 shows a working piston for a device according to Fig. 3 with a continuous piston shaft 73. The piston shaft 73 is purely cylindrical and thus has the simplest possible shape. A bore 74 can also be made in the piston shaft 73, which, if necessary, also protects against media space a plug 75 can be closed. Such a bore can also be used, among other things, for medium to guide the shaft 73 onto the fastening element to be placed. The piston plate 76 and its area for receiving the piston skirt or guide 76a are configured accordingly.

FIG. 9 shows a working piston for a device according to FIG. 3, which has a separate ring element 77 in the area of the piston plate 78. This can, for example, reinforce the piston skirt in this area or also serve to change the piston mass. In addition, it can serve as a special damping element when it hits the inner web 80 of the correspondingly adapted collecting sleeve 79. In this way, for example, the placement process in the area of the piston sleeve 78 and the outer web 81 of the collecting sleeve 79 and the combination of the ring element 77 and the inner web 80 of the collecting sleeve 79 can take place at different times.

From the above explanations, it can be seen that in the new device, the working piston with its possible variations represents the central component of the device. It is particularly important to divide it into a stem area and a piston plate area. It is only this subdivision that gives the constructive and material scope that has already been described, which enables optimal adaptation to the respective load situations.

FIGS. 10A to 10E show some examples for varying the working stroke 31 or the setting depth. The setting depth or the working stroke 31 can be varied, for example

- by changing the length of the entire working piston;

by the choice of piston shafts of different lengths, for which reference is made to the corresponding representations of FIGS. 7, 8, 10A and 10B;

by shaft extensions 83 of different lengths, which are either permanently connected to the piston shaft 84, for example soldered, glued or metallically connected, or which are interchangeable and mortised, screwed together via a pin 85 of the shaft attachment 83 or a pin 86 of the piston shaft 84, for which reference is made to FIG. IOC;

- By changing the length of the piston sleeve 35, for which reference is made to Fig. 10D; by changing the length of the sleeve web 39 or the collecting sleeve, for which reference is made to FIG. 10E;

by different mounting depths of the piston skirt 70 in the piston plate 71 with a sufficient height of the piston plate, for which reference is made, for example, to FIG. 7B;

- by suitable combinations of the individual options just mentioned.

For a number of possible uses of the new device, it can be assumed with the principle proposed here that damping, even with empty shots, can be dispensed with. In this case, the overall length of the working piston unit is reduced to a minimum. Corresponding implementations of the device are shown in FIGS. 11A to 11C. According to FIG. HA, the piston sleeve 35 is placed directly on a ring 87, which is followed only by an attenuator for the device 19, as shown in FIG. 1. A flat wire spring was arranged in the spring chamber 55b as a spring element, for which purpose reference is made to FIG. 5e.

11B shows a further variant of the new device. Here, the piston sleeve 35 rests directly on the front boundary surface of the piston chamber 87a.

In order to increase the working stroke, the ring 87 can be omitted for a given length of the piston sleeve 35 and the front end face of the spring element 55b can be moved correspondingly far forward by directly placing it on the mounting sleeve 89, for which purpose reference is made to FIG. 11C.

In principle, it is also conceivable for the piston shaft 34 to be resiliently mounted via an inner piston plate 90 in a correspondingly designed outer piston plate 91. This can be done for example by means of a piston plate spring 92 or via an elastomeric damping element 90a, for which reference is made to FIG. 12A. 12B shows a variant in which the piston plate 90, which is sprung, for example, via a piston plate spring 92 or an elastomeric layer 90b, is acted upon directly by the gas force. 13A and 13B relate to an embodiment of the new device for highly specialized applications.These are tandem systems with a working piston plate 97, in which there is a further piston or secondary piston 94. According to FIG. 13A, the secondary piston 94 is running, and one of them has the associated piston rod 95, which is arranged in the piston shaft 96 of the outer working piston. In this example, the secondary piston 94 and the outer working piston can be separated separately, for example via a media feed 46 for the sel piston and 94 and a media feed 47 a for the outer working piston, for which reference is also made to FIG. 4A

In the example in FIG. 13B, the inner piston 94 moves in a rear piston sleeve closed by a cover 98

In the devices shown in FIGS. 13A and 13B, the piston rod 95 of the secondary piston 94 can perform a movement over a distance 99 relative to the piston shaft 96 of the working piston. This makes it possible, for example, to use a correspondingly designed fastening element or bolt To trigger additional function

In the embodiments of the new device described so far, it was assumed that the working piston is driven by an auxiliary fluid, for example a gas generated by pyrotechnic technology.As already mentioned, in addition to this generally customary propulsion by means of gas power, there are other possible additions. Particularly interesting is certainly interesting electromagnetic smearings The possible uses of these should be described in the following in a sketchy manner, ie without circuits and power supply, whereby the relevant basics are available in the CCG course from Sterzelmeier

In principle, so-called coil accelerators come into consideration here, which work in the form of a pulse with induction for a limited time. In the application under discussion, a so-called flat coil accelerator, as is known from electrodynamics, primarily comes into consideration. The principle based on ZENZ's principle exists as is well known, then, that it is well

REPLACEMENT SHEET (RULE 26) the ring, which is in magnetic coupling with a coil, a current pulse is conducted. Both parts repel each other with great force. The principle can be applied to both ring-shaped and flat elements. A distinction can be made here:

- Coil system in the piston sleeve or ring accelerator;

- Coil system in the piston plate or flat coil accelerator;

- electromagnetic braking device.

Control is a particular advantage of electrical equipment. For example, the energy can be set according to the required setting power. Due to the very short signal propagation times, it is also possible to control the system itself during the setting process.

Two possibilities are shown in FIG. 14A. A primary coil 100 accelerates a secondary coil 101 in the bottom of the piston plate. Alternatively or in parallel, the working piston can also be driven via a radial coil system 102.

It is also possible to reset the working piston via corresponding coil systems 103 and 104 with the secondary coil 105, housed in a ring 106, for which reference is made to FIG. 14B.

Basically, an electromagnetic drive with axially shorter, more preferably laterally extended systems is recommended. On the one hand, the efficiency increases with larger coil systems, on the other hand, with higher accelerations, larger radial forces have to be absorbed by the material surrounding the coils.

Claims

Patent claims:

1. Device for setting a fastening element (4) into a setting base (6), with a comprising a piston rod (34) and a piston plate (11)

Working piston for loading the fastening element (4) when setting, the piston plate being displaceable in a piston guide sleeve (7) during a working stroke (31) from a rest position to an end position, characterized in that a stop surface (37.) On the working piston (11, 34) ) is arranged, which in the

End position on a counter surface (43) arranged on the piston guide sleeve (7)

System comes to limit the working stroke (31).

2. Device according to claim 1, characterized in that the stop surface (37) is formed by the front end surface of a piston sleeve (34) connected to the piston plate (11) and surrounding the piston rod (34) concentrically.

3. Device according to at least one of the above claims, characterized in that the counter surface (43) through the piston facing free surface of a with the piston guide sleeve (7) connected parallel to the longitudinal axis of the piston rod (34) in the guide sleeve (7) protruding sleeve (38, 39) is formed.

4. Device according to at least one of the above claims, characterized in that the piston sleeve (35) and / or the interception sleeve (38) have web-like partial surfaces arranged centrally symmetrically to the longitudinal axis of the piston.

5. Device according to at least one of the above claims, characterized in that the stop surface (37) and the counter surface (43) are annular or conical

6. Device according to at least one of the above patent claims, characterized in that the space delimited by the piston sleeve (35) or the intercept sleeve web (39) and the piston rod (34) forms a spring chamber (44), with which a reset position (8 ) is arranged to push the working piston (11, 34) back from the end position into the starting position

7. Device according to at least one of the above claims, characterized in that anti-additives are provided for driving the working piston (11, 34), which are based on a chemical / pyrotechnic basis or on pressure fluid or on an electromagnetic basis or on an electrothermal basis

8 • Device according to at least one of the above claims, characterized in that the piston shaft (34) on its front surface contains a protruding or thickening device and / or a receiving part making contact with the fastening element (4) and / or as a hollow or solid punching tool is formed, wherein its front area differs in diameter and / or shape from its rear area

9. Device according to at least one of the above claims, characterized in that the piston skirt (34) or the piston plate (11) or the piston sleeve (35) is cast, turned, forged or drawn and made of heavy metal. Steel, light metal such as duralumin or titanium, a ceramic material, a fiber composite material, a hammered or work-hardened metallic material or a multi-gradient material.

10. The device according to at least one of the above claims, characterized in that the piston shaft (34) has a bore and / or consists of a central cylindrical core and a shaft sleeve enclosing this and / or is variable in diameter and length and / or one has any cross section.

11. Device according to at least one of the above claims, characterized in that the piston plate (11) on the side of the drive means is flat or contains a recess on at least one side and / or on the side of the drive means a device for media guidance and / or distribution.

12. Device according to at least one of the above claims, characterized in that the piston plate (11) has an element inserted into a bore (67).

13. Device according to at least one of the above claims, characterized in that the piston plate (11) is sealed against the media space (46) by means of a ring (49a) or a labyrinth seal (49b).

14. Device according to at least one of the above claims, characterized in that the piston skirt (34) and the piston plate (11) by thread, soldering, gluing, vulcanizing, clamping or shrinking, friction welding, or on the mutual contact surfaces metallic, for example by sintering or bonding

15. Device according to at least one of the above claims, characterized in that an elastomeric buffer, a metallic element, a friction clamp, a spring element and / or a ring element is arranged for braking the working piston (3), the ring element being clean on at least one side is cylindrical and / or contains a recess on at least one side

16. Device according to at least one of the above claims, characterized in that the ring element or the interception sleeve has an outer web and / or a male web

17. Device according to at least one of the above claims, characterized in that the supply of the working fluid is carried out centrally or decentrally, for example via feeds distributed over the circumference

18. Device according to at least one of the above claims, characterized in that the return device (8) is a rubber sleeve or a rubber hose (52), a hollow-chamber rubber system (53a), for example a metallic or polymeric resilient bellows (53b), a rubber spring (54a), a spiral spring (55a), a flat wire spring (55b) and / or multi-part or multi-stage spring elements (57), the latter possibly having a guide (57c).

19. Device according to at least one of the above claims, characterized in that the piston plate (11) is designed as a step plate (60) with a front piston plate part and a rear piston plate part, the drive being carried out simultaneously via at least one of the two stages.

20. Device according to at least one of the above claims, characterized in that the steps of the step plate (60) consist of the same, preferably homogeneous material or of different materials and by soldering, welding, screwing or vulcanizing or metallic on their contact surfaces, for example by sintering or bonding.

21. Device according to at least one of the above claims, characterized in that a ring element (77) is connected to a piston skirt (73) or a piston plate (78) which serves to change the mass, the ring element (77) preferably having resilient properties and is preferably supported directly on the collecting sleeve (79).

22. Apparatus according to at least one of the above claims, characterized in that the working piston (97) contains a secondary piston (94) arranged in it, and that preferably the working piston (97) and the secondary piston (94) can be driven, the secondary piston in an open or closed system is movable.

23. Device according to at least one of the above claims, characterized in that a damping element (92) is located between the piston skirt (34) and piston plate (90).

24. Device according to at least one of the above claims, characterized in that at least two piston shafts are fastened in the piston plate (11).

25. Device according to at least one of the above claims, characterized in that a damping element (92), for example with a metallic spring or with an elastomeric element, is arranged between the piston plate (90) and a piston plate cover (90a).

26. Use of the device according to at least one of claims 1 to 25 for fastening a component (5) to the surface of a setting substrate (6) by means of a fastening element (4), characterized in that the component (5) to be fastened to the surface of the Setzgrundes (6) is brought that the device with its shaft guide sleeve (16) on the component (5) is stopped, with the working piston (3) is in its rest position, and that the working piston (3) is driven until he reaches his end position in order to put the fastening element (4) through the component (5) into the setting surface (6).