US3365879A - Hydraulic transmission power plants and liquid fuel injection devices for internal combustion engines - Google Patents

Description

' Jan. 30, 1968 P. PANHARD 3,365,879 HYDRAULIC TRANSMISSION POWER PLANTS AND'LIQUID FUEL INJECTION DEVICES FOR INTERNAL COMBUSTION ENGINES Original Filed Nov. 19, 1965 5 Sheets-Sheet I.

5 l Q N i 564/ pan/2am! ATTORNEYS P. PA NHARD 3,365,879 HYDRAULIC TRANSMISSION POWER PLANTS AND LIQUID Jan. 30, 1968 FUEL INJECTION DEVICES FOR INTERNAL COMBUSTION ENGINES Original Filed Nov. 19, 1965 5 Sheets-Sheet 2 R O N E v m Pqa/ l d/Marc! mam ATTORNEY S P. PAN HA RD 3,365,879 HYDRAULIC TRANSMISSION POWER PLANTS AND LIQUID Jan. 30, 1968 FUEL INJECTION DEVICES FOR INTERNAL COMBUSTION ENGINES Original Filed Nov. 19, 1965 5 Sheets-Sheet 3 P. PAN HARD 3,365,879 HYDRAULIC TRANSMISSION POWER PLANTS AND LIQUID 7 Jan. 30, 1968 FUEL INJECTION DEVICES FOR INTERNAL (-OMBUSTION ENGINES Original Filed Nov. 19, 1965 5 Sheets-Sheet 4 ATTORNEYS Jan. 30, 1968 P. PANHARD 3,365,379

HYDRAULIC TRANSMISSION POWER PLANTS AND LIQUID FUEL INJECTION DEVICES FOR INTERNAL COMBUSTION ENGINES Original Filed Nov. 19, 1965 5 Sheets-Sheet 5 ATTORNEYS United States Patent ()fiice 3,365,8l Patented Jan. 36, 1968 3,365,879 HYDRAULIC TRANSMISSTUN POWER PLANT; AND LIQUID FUEL INJECTEGN DEVICES 113R INTERNAL 'COMBUSTQEON ENGRNES Paul Panhard, Paris, France, assignor to Socicte Anonyme Andre Citroen, Paris, France, a French society Continuation of application Ser. No. 514,731, Nov. 19,

1965. This application Apr. 18, 1967, Ser. No. 633,671 Claims priority, application France, Nov. 25, 1%4, 996,284, 996,285 8 Claims. (Cl. nth-14) ABSTRACT (F THE DISILDSURE A hydraulic transmission power plant including an internal combustion engine having a cylinder and piston slidable therein. A hydraulic generator is operatively connected to be driven by the engine and includes-at least one tubular plunger riding in a liquid filled cylinder. A closed hydraulic circuit is provided from a delivery valve to a suction valve both of which are mounted on the generator cylinder. A hydraulic receiver is provided in the hydraulic circuit and a. damping capacity is connected with said circuit upstream of said suction valve and a further damping capacity is connected with the hydraulic circuit downstream of said delivery valve. A holding capacity of variable volume is connected with said generator cylinder between said two valves. The capacities are arranged with their respective axes disposed in star-shaped arrangement about the axis of the hydraulic generator cylinder.

An internal combustion having a compression cylinder and an engine provided with a tubular casing rigid with the engine cylinder head and extending coaxially therein, and a different sized, double headed metering member therein coaxially slidable in said casing. A tubular plunger is provided rigid with the piston riding in said cylinder such that the plunger fits slidably about said casing. The casing and plunger are provided with at least one orifice and passage so that when the piston nears its outer dead center, an annular space in the casing communicates with the engine compression cylinder so that the metering member is displaced by pressure applied on one end thereof to effect injection into the engines cylinder 21 This application is a continuation of application Ser. No. 514,731, filed Nov. 19, 1965.

The present invention concerns hydraulic transmission power plants including an internal combustion engine, a hydraulic generator (or pump) having pistons (or plungers) and driven by said engine and a receiver (or hydraulic motor) fed from said generator and coupled with the parts to be driven by the power plant, which parts may comprise, in particular, of wheels of an automobile vehicle on which the power plant: is fitted.

A-m'ain object of the invention is to provide a power plant of this type which is better adapted than those existing at the present time to meet the requirements of practice, in particular concerning its simplicity of construction.

A feature of the invention relates to power plants of this type where the cylinder, or at least one of the cylinders, of the hydraulic generator cooperates, on the one hand, with two damping capacities connected, respectively, upstream of a suction valve and downstream of a delivery valve of said generator and, on the other hand, with a holding capacity branched between these two valves to receive a variable portion of the liquid ill delivered, on every cycle, from said hydraulic generator cylinder, thus determining a variable ratio of transmission between said generator and said receiver. This feature consists in mounting the respective axes of said three capacities (two damping capacities and a holding capacity) in star-shaped fashion about the geometrical axis of said generator cylinder, said three respective axes being advantageously located, at least approximately, in a plane intersecting said generator cylinder.

Advantageously, the internal combustion engine is of the double action type including a single free piston slidable in a cylinder having two opposed cylinder heads, said free piston carrying, on either side thereof, a rod constituting a plunger for the hydraulic generator, the cylinder of which is rigid with that of said engine, the unit formed by said two cylinders being free to oscillate in the axial direction about a position of equilibrium and being thrown, on every motor stroke, in a direction opposed to that of the movement of the piston and rods unit, the displacements of said two units being inversely proportional to their respective masses, the ratio of which advantageously averages 20/1 (cylinder unit mass to piston and rods 'unit mass).

Another feature of the invention relates to power plants of the above-mentioned type where the cylinder, or at least one of the cylinders, of the hydraulic generator communicates with a holding capacity consisting of a shell divided by a movable or deformable partition into two chambers one of which communicates permanently with the hydraulic generator upstream of the delivery valve thereof, whereas the other chamber is placed in communication, at the end of every suction stroke of the generator pistons, with a source of gas at variable pressure, whereby, on every cycle, a first portion of the liquid delivered by the generator is admitted into the first-mentioned chamber of said holding capacity until the respective pressures on opposite sides of said delivery valve become equal to each other, after which a second portion of the liquid delivered by the generator is delivered through this delivery valve. This other feature of the invention consists in making said movable or deformable partition in the form of a rubber (or other elastomer) membrane mounted on a rigid support constituted by a perforated tube and carrying on its end a check valve which cooperates wiih a seat disposed between the second-mentioned chamber and said source of gas at variable pressure, said check valve being mounted to open toward said second chamber.

A second aspect of the invention relates to feed devices for internal combustion engines of the kind where liquid fuel is injected into the cylinders of said engines. The invention is more especially, but not exclusively, concerned with fuel feed devices for free piston engines and more especially in the case where the pistons of said engines are rigid with the pistons or plungers of generators (or pumps) for hydraulic transmission systems.

The object of the second aspect is to provide a device of this kind which is simpler and less expensive in its construction.

According to the second aspect, the feed device is characterized by the combination of at least three features which are as follows: First, in a tubular sheath fixed with respect to the internal combustion engine cylinder, there is disposed a metering member consisting of a rod provided with two heads slidable in fluid-tight contact with said sheath with a limited length of stroke, the head nearest to the engine cylinder, hereinafter called big head, having a cross section greater than that of the other head and being subjected, on. its side farthest from said other head, to the pressure existing in the compression chamber of said engine cylinder; secondly, a pipe for the feed of fuel under low pressure through a check valve opens into the annular space between the fuel metering member rod, as limited by said heads and the sheath that surrounds said rod; and, thirdly, said sheath is disposed inside a tubular plunger rigid with the engine piston and adapted to open at least one orifice provided in said sheath, and thus to connect the above-mentioned annular space with said compression chamber when the engine piston is near its Outer dead center position, whereby the metering member, which was fixed in position by the column of liquid in said above-mentioned annular space, can be displaced by the gaseous pressure applied on the big head thereof and thus inject into the engine cylinder a volume of fuel equal to the difference between the volumes displaced respectively by said two heads.

A preferred embodiment of the invention will be hereinafter described with reference to the appended drawings, given merely by way of example, and in which:

FIG. 1a diagrammatically shows a power plant according to the invention, the hydraulic generator of which is shown in axial section, the left-hand side of this section corresponding to the section line Ia1a of FIG. 2a and the right-hand side of this section to the section line 117-112 of FIG. 221;

FIG. 2a is a radial cross section on the line II--II of FIG. la; and

FIG. 3a is a curve illustrating the operation of this power plant.

FIG. 1 shOWS, with portions shown in elevation and portions in axial section, a power plant according to the second aspect of the invention with a hydraulic transmission, made according to the invention;

FIG. 2 shows, on an enlarged scale and in axial section, a detail of FIG. 1; and

FIG. 3 shows a portion of FIG. 2 but with a different position of the parts.

The hydraulic transmission power plant illustrated by FIGS. la, 2a, and 3a is adapted to drive an automobile vehicle.

Concerning the general structure of the power plant, it is made according to the indications of the French Patent No. 1,350,753 of Dec. 15, 1962.

The system comprises the following elements:

(a) an internal combustion engine A;

(b) a hydraulic generator including two opposed groups each comprising a cylinder 101, a plunger 102, a suction valve 193, and a delivery valve 164, said hydraulic generator being driven by engine A as it will be hereinafter explained;

(c) a receiver, or hydraulic motor, B, the intake of which is connected, through pipes such as 105' (FIG. 2a), with the delivery valves 1614 of the hydraulic generator and the delivery of which is connected, through pipes such as 106 and a tank 107, with the suction valves 103 of said hydraulic generator, said receiver B being coupled with the delivery wheels (not shown) of the vehicle;

(d) two damping chambers C and D communicating with each hydraulic generator cylinder 101, respectively upstream of the suction valve 103 and downstream of the delivery valve 104 thereof; and

(e) a holding chamber E connected to each of the cylinders 101 of the hydraulic generator between valves 103 and 164.

The axes of the three chambers C, D, and E are disposed in star-shaped arrangement about the geometrical axis of each cylinder 101 and preferably, as shown, in a plane intersecting this cylinder.

Each of the capacities C and D comprises a bell-shaped vessel 108 and a base portion 109 between which is tightly held a diaphragm 110 the deformations of which are limited in both directions by rigid perforated cupshaped supports 111 and 112. In the drawings, the reference numerals of the elements relative to capacities C and D are followed by letters and d, respectively. In each base portion 169 there is provided a valve seat 113 cooperating with valve 1553 or 1114. Capacity E comprises an external shell 114.

Each bell-shaped vessel 1180 is subjected, through a pipe 137, to a gaseous pressure corresponding to the mean valve of the suction, and every bell-shaped vessel 168d is subjected, through a pipe 13-8, to a gaseous pressure corresponding to the mean delivery pressure.

As shown by FIG. 2a, bell- shaped vessels 1080, 108d and 114 corresponding to a cylinder 1111 of the hydraulic generator may be fixed upon the same block 115 through nuts 116 or 117 in such manner that their respective axes makes an angle of about degrees with one another in a plane perpendicular to the axis of said cylinder 101, which cylinder is itself formed in block 115. Said block 115 further carries the suction and delivery connections 118a and 118d for pipes 1136 and 105, respectively.

Each of the holding chambers E comprises a bellshaped shell 114 and a movable or deformable partition 1211 which separates the inside of said shell 114 into two chambers 119 and 121 chamber 119 being connected permanently through an orifice 126 with the portion of the corresponding cylinder 101 between valves 10?) and 104, whereas chamber 120 is placed in communication, at the end of every suction stroke of plunger 102, with a source S of gas under variable pressure, this pressure being preferably proportional to the torque supplied by engine A. Advantageously, this source S is made as indicated in French Patent No. 1,350,753. Deformable partition 121 consists of a membrane, for instance of rubber, surrounding a perforated rigid tube 122. fixed in shell 114 coaxially therewith. Membrane 121 carries, fixed to the bottom thereof, a check valve 123 the seat 124- of which is rigid with shell '114 and is interposed between chamber 120 and gas source S. To the bottom end of tube 122 there is fixed an ogive 125 in the bottom portion of which there is' provided a cylindrical housing communicating through a passage 127 with chamber 119 and accommodating a piston '127 subjected to the action of a spring 128 and bearing against the bottom of membrane 121, so that check valve 123 closes during the delivery stroke of plunger 102 as soon as the pressure of oil in chamber 119 is equal to that of the gas present in chamber 120' and reopens during the suction stroke of plunger 102.

Thus, on every cycle, the first portion of the liquid de livered by a plunger 1152 is admitted into chamber 119', causing membrane 121 to expand and to compress the gas present in chamber 1211, check valve 123 being then closed. Then the respective pressures on the opposed sides of delivery valve 104 become equal. Delivery valve 104 then opens, and the second portion, i.e., the remainder of the liquid driven by plunger 1112, is discharged past said valve 194. The power supplied to receiver B and the ratio of transmission depend upon the respective values of the two above-mentioned liquid portions and, therefore, upon the pressure of source 15. During the next suction stroke of plunger 102, the energy corresponding to the compression of gas in chamber 120 is restored to said plunger 102. Then check valve 123 reopens.

As shown by FIGS. 1a and 2a, membrane 121 and tube 122 are held between bell-shaped shell 1 14 and block 115 by means of nut 117.

The internal combustion engine A is of the double action type and includes a single free piston 129 mounted in a cylinder 139 having two cylinder heads 136. This piston 129 carries, fixed thereto on each opposite side thereof, a rod 102 forming a plunger for the hydraulic generator, each cylinder 1611 of which is formed in a block 115 rigid with cylinder 130. The unit formed by cylinder 131), blocks 1-15 and the parts rigid therewith is arranged to be freely oscillable in the axial direction, about a position of equilibrium, by being thrown, on every motor stroke, in a direction opposed to that in which oscillates the unit formed by piston 129 and rods 102, the displacements of the two units being inversely prooprtional to their respective masses. Advantageously, the ratio of the mass of the first unit 130-115 and of the mass of the second unit 129 1112 averages 20/1.

In order to enable the first unit to move freely in this manner, it may be suspended, through parallel connecting rods 131, to spindles 132 carried by a fixed frame. When these connecting rods 131 are disposed on either side respectively, of the movable unit (as shown by FIG. 111), most of the surface of this unit is free and can be fitted with cooling tins 133 of large dimensions. Besides, cooling is improved by the fact that the cylinder unit is moving in air.

FIG. 1a shows an intake pipe 134 and an exhaust pipe 135 for internal combustion engine A, the respective ports corresponding to said pipes being controlled by piston 129. These ports may be the same for both sides of the engine or, as shown by the drawings, be separate if it is desired to give them an inclination in order to improve the guiding of the gaseous streams and to reduce the temperature of the cylinder at this place. The fuel feed system and possibly the ignition system have not been shown in the drawings and may be of any type applied in the case of free piston engines. The whole of piston 129 and plungers 102 is shown in solid lines on the right-hand side, i.e., near the end of the rightward stroke of the piston. The end of the leftward stroke of said piston is shown in dot-and-dash lines on the left-hand side of FIG. 1a.

In the embodiment illustrated by FIGURES 1a, 2a, and 3a of the drawings, the movable unit includes, on either side, star-disposed capacities C, D, and E. Pipes 105 and 106 must include a flexible portion in order to permit the displacement of said movable unit.

In the case where the power plant is intended to be used on an automobile vehicle, the group shown in FIG. 1a is preferably disposed in such manner that the axis of cylinder 130 corresponds to the axis of maximum inertia of the support, that is to say, to the longitudinal axis of the vehicle.

The operation and the advantages of the power plant according to the invention are as follows:

The operation is very different from that of usual free piston engines.

As a matter of fact, in said engines, in order to obtain a good balancing, use is made of two opposed pistons mounted in a common cylinder and which oscillate under the effect of two forces. These forces are, on the one hand, that resulting from the combustion of the fuel and air mixture, and on the other hand, a resilient return force capable of supplying the energy necessary for com pression of this mixture. For practical purposes, such an arrangement is suitable for engines running at nearly constant speed, because the variable load is balanced by injecting a variable amount of fuel.

On the contrary, in the internal combustion engine according to the invention, piston 1'29 oscillates constantly between two exactly symmetrical and simultaneously variable forces, the piston receiving always on one of its end faces the energy of explosion or combustion, whereas the other end face serves to compress the mixture or an amount of air, and plunger 102, which forms an extension of said piston, supplies a hydraulic work identical for every half stroke thereof.

If the operation is analyzed by calculation, it is found that it is possible, While maintaining a constant stroke of the piston, to vary the number of reciprocations thereof per minute to a considerable degree and that to every speed of reciprocation corresponds an exactly given power.

Calculation for an engine having a cylinder bore of 85 mm. and a stroke of 75 mm. shows, for instance, that with a weight of the piston movable unit equal to 1.250 kgs, the number of reciprocations for a power equal to zero is about 2600, whereas it passes to 3600 for a power of HP collected hydraulically, to 4200 for HP and to 4600 for HP.

If such a unit is mounted on a vehicle where the hydraulic receiver B requires 2600 reciprocations at full rate at a speed of kin/11., it is seen that, for all speeds below 95 km./h., one may apply to the wheels a power varying 6 from 0 to 60 HP (with the restriction that the adhesion at very small speed practically does not permit utilization of all the power that is available).

Above 95 km./h., it is not possible to utilize the powers ranging from 0 HP to the minimum power corresponding to full rate at the corresponding number of reciprocations. This is visible on FIG. 3a.

This figure shows, at a, the curve (in dotted lines) giving the relation between the number or" reciprocations (N per minute) and the power supplied by the engine (p in HP) which is a characteristic of this kind of engine.

Curve 1; shows (in solid lines) the curve of the power necessary for obtaining a predetermined speed of the vehicle (V in km./h.).

The ordinate AA corresponding to the speed of km./h. intersects curve a at H and curve b at M. It is seen that, at 120 krn./h., the number of reciprocations at full rate is 3295 and the power is 12 HP. It follows that, at 120 km./h., it is possible to use all the powers ranging from 12 to 60 HP. In a likewise manner at km./h. the power available ranges between 26 and 60 HP.

As it is an important condition that every speed can be maintained without either acceleration or slowing down, curve a must not intersect curve 1) within the whole zone of possible use of the vehicle.

The invention does not require: the use of devices such as crank shafts, connecting rods or any other mechanisms for transforming the movement. It permits, at a cost much lower than that of conventional systems (engine-clutchgear-box transmission), obtaining an operation which is automatic in all circumstances, the driver adjusting merely the power brought into play in engine A, without having to intervene otherwise if the gradient of the road or the driving circumstances undergo modifications. The power plant is very compact and permits reducing the space generally reserved for the engine and its accessories. Finally, the freedom of the power cylinder avoids the usual reactions upon the body of the vehicle and increases the comfort of the passengers by reducing vibrations and noises.

The system illustrated in FIGURES 1, 2 and 3 comprises the following elements:

(a) An internal combustion engine A;

(b) A hydraulic generator (or pump), including two opposed groups each comprising a cylinder 1, a plunger (or rod) 2, a suction valve 3 and a delivery valve 4, said hydraulic generator being driven by engine A, as it will be hereinafter explained;

(c) A receiver, or hydraulic motor, B the intake of which is connected, through pipes 5, with the delivery valves 4 of the hydraulic generator and the delivery of which is connected, through pipes 6, with the suction valves 3 of said hydraulic generator, said receiver B being coupled with the delivery wheels (not shown) of the vehicle;

(d) Two damping chambers C and D communicating with each cylinder 1 and connected respectively upstream of the suction valve 3 and downstream of the delivery valve 4 thereof; and

(e) A holding chamber E connected to each of the cylinders 1 between valves 3 and 4 so as to receive a variable portion of the liquid delivered on every cycle from said cylinder 1, thus determining the ratio of transmission between engine A and receiver 13.

According to the disclosure of the invention of FIG- URES la, 2a, and 3a herein, and the invention disclosed in [1.8. Patent application Ser. No. 508,670, filed Nov. 19, 1965, in the same name, the three chambers C, D and E are disposed in star-shaped manner about the geometrical axis of each cylinder it and preferably at the same transverse level as this cylinder. In FIG. 1 the cross section plane for the upper part of the drawing is the same for both of the units and therefore shows both of the chambers D located on the right hand and on the left hand, whereas the cross sections corresponding to the lower portion of FIG. 1 are made, respectively for the right-hand side and the left-hand side, through two planes symmetrical with respect to said vertical plane and making between them an angle of 120 degrees so that the lefthand portion shows a chamber E and the right-hand portion a chamber C.

According to the disclosures referred to in the preceding paragraph, the internal combustion engine is of the double-action type and includes a single free piston 7 mounted in a cylinder 8 having two cylinder heads 9. This piston carries, fixed thereto on each opposite side thereof, a plunger or rod 2 and the hydraulic generator cylinders 1 cooperating with said rods 2 are provided in blocks 10 rigid with cylinder heads 9. The whole of cylinder 8, cylinder heads 51 and blocks 10 is arranged to be freely oscillable along its axis in a direction opposed to that in which oscillates the whole of piston 7 and plungers 2. The internal combustion engine intake pipes are designated by reference numeral 11 and the exhaust pipes by 12, the corresponding ports being controlled by piston 7.

Referring new again to FIGS. l3, herein, the liquid fuel feed device of the internal combustion engine is made, on either side of piston 7, in the following manner:

There is disposed, inside a tubular sheath 14, fixed with respect to cylinder 8, a metering member 15 consisting of a rod 15a provided with two heads 15]) and 150 adapted to slide, with a limited amplitude, in fluid-tight contact with the inner face of sheath 14 and with a surface in line therewith provided in a cap 16 fixed to block 10. The cross section S of the head 15b nearer the cylinder 8 is greater than the cross section s of the other head 15c and it is acted upon, on its surface farthest to said other head (on the left-hand side in FIGS. 2 and 3) by the pressure existing in the compression chamber 34 of cylinder 8.

A fuel feed pipe 18 for fuel under pressure, provided with a check valve 19, opens into the annular space 17 between sheath 14 and the rod 15a of metering member 15 (between heads 15b and 150).

Sheath 14 is located inside a tubular sleeve rigid with piston 7 and capable, when piston 7 is nearing its outer dead center position (i.e., its extreme position toward the right in FIGS. 2 and 3), of opening orifices 21 and 22 provided in sheath 14 so as thus to connect the annular space 17 with the compression chamber 34.

In the embodiment of the invention illustrated by the drawings, cap 16 is fixed to block 10 through bolts 23 and nuts 24, sheath 14 being welded to cap 16. Said cap is provided with a bore 25 of a diameter smaller than the inner diameter of sheath 14, and intended to accommodate the small head 150 of metering member 15.

The above-mentioned tubular sleeve rigid with piston 7 is formed by the plunger 2 of the hydraulic generator, whereby the useful pumping cross section of this plunger 2 is reduced by an amount equal to the external cross section of sheath 14.

Said tubular plunger 2 includes, on its inner wall, a sleeve 26 secured thereto by means of a nut 2tl, the inner edge of said sleeve 26 being located on the left of orifices 21, 22 when the internal combustion engine piston 7 is in its outer dead center position (FIG. 2). Means are provided for making fluid-tight, on the one hand, the surfaces of contact (without relative sliding displacement) between the inner wall of plunger 2 proper and the outer wall of sleeve 26 and, on the other hand, the surfaces of contact (with sliding relative displacement) between the inner wall of sleeve 26 and the outer wall of sheath 1 so as thus to separate from each other the fuel circuit and the transmission liquid circuit.

In order to limit the displacement of metering member 15 with respect to fixed sheath 14, there is provided, on the one hand, at the end of the big head 15b, a flange 27 projecting to the outside of sheath 14 and, on the other hand, at the end of the small head 150, a washer 28 cooperating with a fixed but adjustable abutment. Such an abutment consists, in the embodiment illustrated by the drawings, of the inner transverse face of a hollow screw 29 through which small head extends and which is engaged in a threaded portion of cap 16, said screw 29 being rigid with a manually or automatically controlled lever 30.

In order to permit the pressure existing in the compression chamber 34 of cylinder 8 to be transmitted to the big head 151), there is provided at least one passage 31 connecting the external surface of piston 7 with the inside of tubular plunger 2, this passage being provided in an axial plane and being slightly inclined, as shown by FIG. 2 so as to open tangentially to the curved end face of piston 7.

As shown there is further provided, in the wall of tubular plunger 2, at least one fuel injection passage 32, positioned to open opposite orifices 21 and 22 when piston 7 is close to its outer dead center position. Passage 32 may open directly into chamber 34 but preferably, as shown by the drawings, it opens into an annular turbulence chamber 33 provided in cylinder head 9 and surrounding plunger 2.. Advantageously, as shown, said orifice 32 is inclined from the inside toward the outside in the direction away from piston 7 so as to open tangentially to the portion of the wall of chamber 33 that is most remote from piston 7. Advantageously, as shown, sleeve 26 has a bevelled edge 26a in line with the corresponding edge of orifice 32.

The feed device above described works as follows:

If it is supposed that area S is equal to 24 rnm. (diameter of about 5.5 mm.) and that area s is equal to 16 mm. (diameter of about 4.5 mm.), for a displacement of metering member 15 of 1 mm. toward the left of FIGS. 1 and 2, the volume of annular space 17 increases by (2416) mm. 1 mm.=8 mm. If the maximum stroke of metering member 15 is supposed to be 5 mm., the maximum volume of fuel displaced by said metering member is five times greater, that is to say 40 mmfi. Fuel is fed through pipe 13 under a relatively small pressure (some kgs./cm. which overcomes the inertia of the fuel column and the inertia of metering number 15. In order to reduce this last-mentioned inertia, the metering member may be made of a light metal so as to have a weight of only some grams. Besides, the end 15d of metering member 15 may be pushed by a small spring if it is desired to reduce the pressure of the fuel arriving through pipe 18.

When the pressure has dropped in chamber 34, which occurs when piston 7 is near its inner dead center position, i.e., toward the left of FIGS. 2 and 3, the pressure in pipe 18, possibly added to the action of the last-mentioned spring, opens check valve 19 and pushes metering member 15 toward the left of FIGS. 2 and 3 until washer 28 comes into contact with hollow screw 29. There is thus admitted into annular space 17 a volume of fuel proportional to the displacement 1 of metering member 15, which displacement is adjusted by lever 39, that is to say a volume of 8X1 mm. in the example that has been considered (1 being expressed in millimeters).

At the end of the compression stroke in cylinder 8, the pressure in compression chamber 34 is transmitted through orifice 31 to the big head 15b of metering member 15. As soon as the movement of piston 7 and plunger 2 causes the bevelled edge 26a of sleeve 26 to clear orifice 21 (FIG. 3), metering member 15, which was kept in position by the column of fuel enclosed in annular space 17, is released and driven toward the right by said pressure in chamber 34 until orifice 21 is closed.

A portion of said volume of fuel is injected. The injected fuel, driven by the air stream through passages 31 and 32 (as shown by the arrows of FIG. 3), mixes with air in turbulence chamber 33, where it is ignited either by suitable ignition means, or, when the compression ratio is sufficiently high, by spontaneous ignition.

When orifice 22 is subsequently cleared (near the outer dead center position, FIG. 2), the remainder of said fuel volume is injected and, at this time, the combustion in 9 chamber 33 reverses the direction of fiow through passages 32 and 31 (as shown by the arrows of FIG. 2) and causes an ignited fuel mixture to be injected into compression chamber 34 where it finds the amount of air necessary to finish its combustion.

When, at the beginning of injection, there is, for instance, a pressure of 5 kgs./cm. in compression chamber 33, 34, this pressure acts upon head 15b (area S is equal to 24 mm. as above indicated. As the area s of head 150 is 16 mm. the pressure exerted by the fuel contained in annular space 17 is equal to =15 kgs./cn1.

As soon as orifice 21 is opened, fuel is injected under the difference of the pressures existing respectively in said space 17 and in chamber 33, which difference is equal to kgs./cm. The pressure at the end of injection may be much higher (either end of compression or beginning of combustion).

If the stroke and, consequently, the volume of fuel that is injected are small (case of low loads), the orifice 21 of FIG. 3 remains covered by head b and injection takes place only when orifice 22 is cleared by sleeve 26. Combustion takes place only in chamber 33, which ensures a correct operation even with an explosion cycle, the richness of fuel in the mixture being then sufiicient, since only a small portion of the air admitted into cylinder 8 is mixed with fuel.

It will be noted that, since plunger 2 is surrounded with the oil of the hydraulic transmission device (under pressure during the delivery stroke), the operation remains correct even with a fuel (gasoline) having bad lubricating properties.

To sum up, the fuel injection device according to the present invention performs the same functions as the conventional fuel injection devices, but with a greater simplicity and at a lower cost.

In a general manner, while the above description discloses what is deemed to be a practical and efiicient embodiment of the present invention, said invention is not limited thereto as there might be. changes made in the arrangement, disposition and form of the parts without departing from the principle of the invention as comprehended within the scope of the appended claims.

What is claimed is:

1. A hydraulic transmission power plant which comprises, in combination,

an internal combustion engine comprising a cylinder and a piston slidable in said cylinder,

a hydraulic generator comprising at least one tubular plunger operatively connected with said engine piston and a cylinder adapted to cooperate with said plunger, said hydraulic generator cylinder being filled with a liquid,

a delivery valve mounted on said generator cylinder,

a suction valve mounted on said generator cylinder,

a closed hydraulic circuit extending from said delivery valve to said suction valve,

a hydraulic receiver in said hydraulic circuit,

a damping capacity connected with said circuit upstream of said suction valve,

a damping capacity connected with said circuit downstream of said delivery valve,

21 holding capacity of variable volume connected with said generator cylinder between said two valves, and

means for varying said holding capacity variable volume,

said three capacities having their respective axes disposed in star-shaped arrangement about the axis of said hydraulic generator cylinder.

2. A power plant according to claim 1 wherein the respective axes of said three capacities are located substantially in a plane intersecting said hydraulic generator cylinder.

5 kgs./cm. X

3. A hydraulic transmission power plant which cornprises, in combination,

a double action internal combustion engine comprising a cylinder having two opposed cylinder heads and a single free piston slidable in said cylinder.

a hydraulic generator comprising at least one tubular plunger rigid with said piston and a cylinder, rigid with said internal combustion engine cylinder, adapted slidably to accommodate said plunger, said hydraulic generator cylinder being filled with a liquid,

a delivery valve mounted on said generator cylinder,

a suction valve mounted on said generator cylinder,

a closed hydraulic circuit extending from said delivery valve to said suction valve,

a hydraulic receiver in said hydraulic circuit,

a damping capacity connected with said circuit upstream of said suction valve,

a damping capacity connected with said circuit down stream of said delivery valve,

a holding capacity of variable volume connected with I said generator cylinder between said two valves, and means for varying said holding capacity variable volume,

said three capacities having their respective axes disposed in star-shaped arrangement about the axis of said hydraulic generator cylinder.

4. A power plant according to claim 3 wherein the Whole of said cylinders forms a unit capable of oscillating freely in the axial direction about. a position of equilibrium, said unit being thrown, on every motor stroke, in a direction opposed to that of the movement of the unit formed by said piston and said rods, the displacements of said two units being in inverse ratio to their respective masses.

5. A power plant according to claim 4, wherein the ratio of the mass of the first unit to that of the mass of the second unit approximates 20.

6. A power plant according to claim 4 for use in an automobile vehicle, wherein the axis of the internal combustion cylinder and of the hydraulic generator cylinders corresponds to the maximum inertia axis of the support, i.e., to the longitudinal axis of the vehicle.

7. A hydraulic transmission power plant which comprises, in combination,

an internal combustion engine comprising a cylinder and a piston slidable in said cylinder,

a hydraulic generator operatively connected with said engine so as to be driven by it and comprising at least one tubular plunger and a cylinder adapted slidably to accommodate said plunger, said hydraulic generator cylinder being filled with a liquid, delivery valve mounted on said generator cylinder, suction valve mounted on said generator cylinder, closed hydraulic circuit extending from said deivery valve to said suction valve,

a hydraulic receiver in said hydraulic circuit,

a liquid holding capacity connected with said generator cylinder between said valves, said liquid holding capacity including:

a rigid shell,

a resilient deformable membrane of general tubular shape mounted in said shell to divide it into two chambers, a first one and a second one, said first chamber being in permanent free communication with said generator cylinder,

a rigid perforated tube fixed in, said shell inside said membrane for limiting the inward deformations thereof,

a valve seat carried by said shell and opening into said second chamber,

a source of gas under variable pressure arranged on the outside of said shell and adapted to communicate with said second chamber through said valve seat,

a check valve adapted to cooperate with said valve seat and opening toward the inside of said shell into 1 1 said second chamber thereof, said check valve being carried by the end of said membrane so as to be applied on said seat when said membrane expands, and means responsive to the pressure in said first chamber for opening said check valve in response to a suction in said first chamber.

8. A power plant according to claim 7 further comprising a rigid ogive fixed to said tube, said ogive having a flat base located substantially in the same plane as the free end of said tube and the point of said ogive being turned toward said generator cylinder, said ogive being provided with a cylindrical recess opening in the direction of said check valve, a piston slidable in said cylindrical recess and bearing against the end of said mem- References Cited UNITED STATES PATENTS Fraser 123-4399 Petersen 123-1399 Van Der Lely et al. 10354 Johnson et a1 60-44 Anderson et al. 6019 WENDELL E. BURNS, Primary Examiner.

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