DE102011119614A1 - Device for monitoring mixture drum of concrete mixer vehicle, has electronic sensing unit that is arranged on lid or maintenance aperture to monitor close state of lid and connected to mixture drum to control drum drive - Google Patents

Abstract

The device comprises a maintenance aperture (4) that is provided for entrance of a mixture drum (1) and is rotated over a drum drive (2). The maintenance aperture is locked over a lid (5) by a releasable screwed joint. An electronic sensing unit (6) is arranged on a portion of the lid or maintenance aperture for monitoring a close state of the lid and is connected to the mixture drum over a communication link for controlling the drum drive. Independent claims are included for the following: (1) concrete mixer vehicle; and (2) method for monitoring mixture drum of concrete mixer vehicle.

Description

The invention relates to a device for monitoring at least one maintenance opening arranged on a mixing drum of a truck mixer for accessing the mixing drum rotatable via a drum drive for maintenance purposes, wherein the maintenance opening can be closed by means of a detachable screw connection via a cover. In addition, the invention also encompasses a truck mixer comprising such a monitoring device and a method for carrying out the monitoring of the maintenance opening.

The field of application of the invention extends to truck mixers for transporting pulpy building materials, in particular fresh concrete. For this purpose, the fresh concrete is transported from a stationary concrete mixing plant in a rotating mixing drum to the site to prevent segregation or early setting of the fresh concrete.

In order to carry out a cleaning or maintenance of the mixing drum, this has a closable with a lid from the outside maintenance opening, which is usually designed in the form of a so-called manhole, through which a person can get into the mixing drum. However, maintenance openings can also be formed with other geometric dimensions. In addition, the invention can generally also apply to other provided with maintenance openings mixing drums, tanks and the like.

From the EP 2 216 151 A1 A truck mixer with a revolving mixing drum for fresh concrete installed on a vehicle emerges. The drum drive is controlled by a central electronic control, ie switched on or off.

In addition, hydraulic drum drives also emerge from the general state of the art, in which a hydraulic motor connected to the hydraulic circuit causes the mixing drum to rotate as required.

Usually, at least one maintenance opening in the form of a manhole for maintenance purposes is provided on the outside of the mixing drum. The maintenance opening is closed by means of a detachable screw connection with a lid. The releasable screw connection is usually realized by a plurality of screws arranged along the edge region of the cover. After removing all screws, the cover can be removed from the maintenance opening so that a person can enter the mixing drum for maintenance or repair purposes.

For safety reasons, the mixing drum must first be mechanically locked in order to prevent inadvertent rotation of the mixing drum when entering or staying in the mixing drum. For this purpose, mechanical locking devices are used, which can secure the mixing drum against rotation due to an imbalance; in hydraulic drum drives, however, these locking devices can be overcome because of the large drive torque. Thus, known locking devices do not ensure a standstill of the mixing drum under all circumstances. Rather, it depends on the operator whether suitable measures are taken to prevent inadvertent activation of the drum drive during maintenance. This results in an accident risk during maintenance work within the mixing drum.

It is therefore the object of the present invention with simple technical means to prevent inadvertent or negligent starting the mixing drum of a truck mixer during maintenance.

The object is achieved on the basis of a device according to the preamble of claim 1 in conjunction with its characterizing feature. The following dependent claims give advantageous developments of the invention. Technically, the object is achieved by claim 12.

The invention includes the technical teaching that an electronic sensor unit for monitoring the closed state of the lid is arranged on the part of the lid or on the maintenance opening of the mixing drum, which communicates via a communication link with a central control unit for controlling the drum drive.

The advantage of the solution according to the invention lies, in particular, in the fact that the closing state of the lid can be reliably determined by means of technical monitoring means in order in principle to prevent starting of the drum drive when the maintenance opening is open. Because the removal of the cover from the maintenance opening is a prerequisite for monitoring that a person can get into the mixing drum. Since the solution according to the invention acts on this necessary condition for carrying out maintenance work, a reliable accident protection is made possible.

According to a preferred embodiment, the electronic sensor unit comprises an electrical switch for detecting the Closed state of the lid, a power supply for producing a running over the electrical switch monitoring circuit and a communication interface for data connection with the outside of the mixing drum arranged central control unit. The electronic sensor unit should be housed in a protected against dirt and water housing, which is preferably located within the mixing drum. The communication interface of the electronic sensor unit to the central control unit may be formed depending on the nature of the data transmission channel.

According to a preferred embodiment, the communication link is formed wirelessly by the electronic sensor unit comprises a transmission / reception module as a communication interface, which communicates with a corresponding on the part of the central control unit outside the mixing drum arranged transmitting / receiving module via radio data transmission. Advantage of the wireless communication connection is that a cabling between the sensor unit and the central control unit can be omitted, which would be technically complicated especially because of the rotating mixing drum. In the case of a wireless communication link, the power supply is preferably designed as a battery. The battery can be combined with a self-sufficient power supply, for example via an induction circuit. As the battery can be recharged, there is no need for replacement. It is also conceivable to realize a self-sufficient power supply via a solar cell or the like.

According to another embodiment, the communication connection between the sensor unit and the central control unit can also be designed as a control line laid at least partially along the mixing drum. In order to electrically connect the sensor unit mounted on the mixing drum to the central control unit mounted outside the mixing drum by means of a wired communication interface, it is proposed that an electrical rotary feedthrough be provided for the control line in the region of the drum drive. In the case of a wired communication connection, the power supply of the sensor unit can also be done via the control cable, so that a battery can be omitted by the sensor unit.

Preferably, the integrated in the sensor unit electrical switch should be designed as an opener. This ensures that the monitoring circuit is interrupted when the cover is removed from the maintenance opening. The triggering of the monitoring by circuit interruption ensures an increased level of security of the monitoring device according to the invention, since contact errors remain out of consideration.

According to a preferred embodiment, the electrical switch consists of a part of the maintenance opening on the mixing drum in the sensor unit integrated electrical socket which cooperates with a corresponding and arranged on the side of the lid electrical contact plug. The contact plug can be designed as a bridge member to bridge two adjacent poles of the socket. In addition, it is also conceivable that the two poles are arranged one behind the other, so that the electrical contact plug in the form of a contact pin can be designed, which is fixedly attached to the lid to be pulled out with removal of the lid from the electrical socket, whereby the switch opens.

According to another embodiment, the electrical switch can also be formed in a simple manner between the lid made of metal and the maintenance opening of the drum also made of metal. In this case, the cover is the one pole of the switch and the edge region of the maintenance drum represents the other part of the switch. Both require that one pole of the switch is formed by an electric cable attached to the cover and the other pole of the switch through the Mixing drum is formed. In addition, it is also conceivable to form the electrical switch in another way, for example by using prefabricated electrical contact switches, which function as normally closed contacts and are sufficiently robust for the application according to the invention.

According to another measure improving the invention, it is proposed that the electronic sensor unit, designed to be particularly compact, is integrated directly into at least one of the screws of the screw connection between the cover and the maintenance opening. For example, the electronic control unit may be integrated into a screw head to monitor the closed state of the lid by removing the screw via a wireless communication link with the central control unit signaling an open service opening.

• – Vor Einschalten des Trommelantriebs wird zunächst durch die zentrale Steuereinheit ein Kontrollanforderungssignal an die elektronische Steuereinheit der Mischtrommel gesendet. Hierdurch wird also keine permanente Überwachung des Schließzustandes der Wartungsöffnung vorgenommen; diese erfolgt nur auf Anforderung, nämlich vorzugsweise dann, wenn der Trommelantrieb in Betrieb genommen werden soll.
• – Durch die elektronische Steuereinheit wird anschließend ein Stromimpuls über einen den elektrischen Schalter beinhaltenden Überwachungsstromkreis zur Detektion des Schließzustandes des Deckels gegeben. Hiermit über eine einfache Stromkreisprüfung der Schließzustand des Deckels ermittelt.
• – Stellt die elektronische Steuereinheit einen geschlossenen Überwachungsstromkreis fest, wird an die zentrale Steuereinheit ein Startfreigabesignal für den Trommelantrieb gesendet. Hierdurch wird sichergestellt, dass der Trommelantrieb erst dann in Betrieb genommen werden kann, wenn dieser Prüfalgorithmus positiv durchlaufen worden ist.

The device described above for monitoring the maintenance opening on the mixing drum is preferably operated via the sequence of special control technology monitoring steps, namely:

• - Before switching on the drum drive, a control request signal is first sent by the central control unit to the electronic control unit of the mixing drum. hereby So no permanent monitoring of the closed state of the maintenance opening is made; this takes place only on request, namely preferably when the drum drive is to be put into operation.
• - By the electronic control unit is then given a current pulse via a circuit containing the electrical switch monitoring circuit for detecting the closed state of the lid. Hereby determined by a simple circuit test of the closed state of the lid.
• - If the electronic control unit detects a closed monitoring circuit, a start enable signal for the drum drive is sent to the central control unit. This ensures that the drum drive can not be put into operation until this test algorithm has passed through positively.

On the other hand, if the cover is removed from the maintenance opening, the monitoring circuit is opened and the central control unit can not generate a start enable signal for the drum drive, so that commissioning of the mixing drum is prevented.

In the case of a wireless communication connection between the sensor unit and the central control unit, the safety algorithm can be completed by detecting that the monitoring circuit is not closed when the sensor unit is removed or empty, so that a start release for the drum drive is omitted until the battery has been replaced so that the electronic sensor unit is operational again. A battery change should be possible from the outside.

Further measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention with reference to FIGS. It shows:

1 1 a schematic side view of a truck mixer with a mixing drum provided with a maintenance opening,

2 a schematic side view of an installed in the maintenance opening of the mixing drum electronic sensor unit,

2a a schematic side view of an integrated in a screw head electronic control unit,

3 a block diagram representation of a wireless monitoring device, and

4 a block diagram representation of a wired monitoring device.

According to 1 is the mixing drum 1 a truck mixer via a stationary to the truck mixer arranged drum drive 2 set in rotary motion. The drum drive 2 is via a centralized electronic control 3 controlled in accordance with the operator. Next to it acts the central control unit 3 also with technical means for monitoring one of the mixing drum 1 arranged maintenance opening 4 in terms of closing state together. The maintenance opening 4 is normally, ie during operation of the mixing drum 1 , with a lid 5 closed by a detachable screw connection.

For safety reasons, ensure that the drum drive 2 the mixing drum 1 with open maintenance opening 4 is not activatable, is from the maintenance opening 4 the mixing drum 1 an electronic sensor unit 6 arranged, which the closed state of the lid 5 on the maintenance opening 4 supervised. The electronic sensor unit 6 is via a communication link between the sensor unit 6 and central control unit 3 serving control line 7 with - not shown - electrical rotary feedthrough in the field of drum drive 2 in connection.

According to 2 includes the screw connection of the lid 5 at the mixing drum 1 several edges along the lid 5 arranged single screws 8th , The next to the screws 8th inside the mixing drum 1 arranged electronic sensor unit 6 includes one in a closed housing 9 housed electrical switch 10 for detecting the closing state of the lid 5 , This is the electrical switch 10 designed as an opener to interrupt a monitoring circuit when the lid 5 from the maintenance opening 4 Will get removed. The electric switch 10 consists in this embodiment of a side of the maintenance opening 4 stationary to the mixing drum 1 arranged electrical socket 11 , which with one on the cover 5 arranged electrical contact plug 12 corresponds.

Furthermore, the electronic sensor unit comprises 6 a power supply in the form of a battery 13 for making the over the electrical switch 10 extending monitoring circuit and a communication interface 14 for data connection with the - not shown here - central control unit.

According to the in 2a illustrated alternative embodiment is a miniaturized electronic sensor unit 6 ' directly into the head of a screw 8th' the screw connection between lids 5 and in the mixing drum 1 integrated maintenance opening integrated. The miniaturized electronic sensor unit 6 ' includes the same components and functional scope of the electronic sensor unit described above 6 ,

The communication connection between sensor unit 6 and central control unit 3 may be formed according to two different embodiments:
After the in 3 illustrated preferred embodiment, this communication connection between the sensor unit 6 and central control unit 3 designed wirelessly, in which the sensor unit 6 as communication interface next to the switch 10 , the battery 13 a transceiver module 14 comprising, which by radio data transmission with a corresponding part of the central control unit 3 outside the mixing drum 1 arranged transceiver module 15 communicated.

After the in 4 The other embodiment shown is the communication connection between the sensor unit 6 and the central control unit 3 over the control line 7 with in the range - not shown here - drum drive arranged rotary electrical feedthrough 15 educated. The at the mixing drum 1 assembled sensor unit 6 further includes a wired communication interface 16 at which the outside along the - not shown here - mixing drum laid control line goes out to the electrical rotary feedthrough 17 to the central control unit 3 to get.

LIST OF REFERENCE NUMBERS

1

mixing drum

2

drum drive

3

central control unit

4

maintenance opening

5

cover

6

electronic sensor unit

7

control line

8th

screw

9

casing

10

switch

11

Rifle

12

contact plug

13

battery

14

Send / receive module

15

Send / receive module

16

Communication Interface

17

Rotary union

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2216151 A1 [0004]

Claims (12)

Device for monitoring at least one of a mixing drum ( 1 ) of a truck mixer arranged maintenance opening ( 4 ) for access via a drum drive ( 2 ) rotatable mixing drum ( 1 ) for maintenance purposes, the maintenance opening ( 4 ) via a lid ( 5 ) is closable by means of a releasably screw connection, characterized in that on the part of the lid ( 5 ) or from the maintenance opening ( 4 ) of the mixing drum ( 1 ) an electronic sensor unit ( 6 ) for monitoring the closed state of the lid ( 5 ) which is connected via a communication link to a central control unit ( 6 ) for controlling the drum drive ( 2 ). Device according to claim 1, characterized in that the electronic sensor unit ( 6 ) an electrical switch ( 10 ) for detecting the closed state of the lid ( 5 ), a power supply for making a via the electrical switch ( 10 ) running monitoring circuit and a communication interface ( 14 ) for data connection to the central control unit ( 3 ). Apparatus according to claim 1, characterized in that the communication connection between the sensor unit ( 6 ) and central control unit ( 3 ) is formed wirelessly by the electronic sensor unit ( 6 ) as a communication interface, a transceiver module ( 14 ) associated with a corresponding part of the central control unit ( 3 ) outside the mixing drum ( 1 ) arranged transceiver module ( 15 ) communicates via radio data transmission. Apparatus according to claim 1, characterized in that the communication connection between the sensor unit ( 6 ) and central control unit ( 3 ) as an at least partially outside along the mixing drum ( 1 ) misplaced control line ( 7 ) with electrical rotary feedthrough ( 15 ) in the area of the drum drive ( 2 ) is adapted to the at the mixing drum ( 1 ) mounted sensor unit ( 6 ) via a wired communication interface ( 16 ) with the outside of the mixing drum ( 1 ) mounted central control unit ( 3 ) electrically connect. Apparatus according to claim 2, characterized in that the power supply as one in the sensor unit ( 6 ) integrated battery ( 13 ) is trained. Device according to claim 2, characterized in that the electrical switch ( 10 ) is designed as an opener to interrupt the monitoring circuit when the lid ( 5 ) from the maintenance opening ( 4 ) is removed. Device according to claim 2, characterized in that the electrical switch ( 10 ) from one side of the lid ( 5 ) or the maintenance opening ( 4 ) arranged electrical socket ( 11 ) and a corresponding thereto and from the maintenance opening ( 4 ) or lid ( 5 ) arranged electrical contact plug ( 12 ) consists. Apparatus according to claim 2, characterized in that the electrical switch between the metal lid ( 5 ) and the maintenance opening ( 4 ) also consisting of metal mixing drum ( 1 ) is formed. Apparatus according to claim 1, characterized in that the screw connection a plurality of edges along the lid ( 5 ) arranged screws ( 8th ). Apparatus according to claim 9, characterized in that the electronic sensor unit ( 6 ' ) in at least one of the screws ( 8th' ) of the screw connection between covers ( 5 ) and maintenance opening ( 4 ) is integrated. Truck mixer with a mixing drum arranged on a vehicle ( 1 ) for building materials whose at least one maintenance opening ( 4 ) is equipped with a device according to one of the preceding claims. Method for monitoring at least one of a mixing drum ( 1 ) of a truck mixer arranged maintenance opening ( 4 ) for access via a drum drive ( 2 ) rotatable mixing drum ( 1 ) for maintenance purposes via a device according to one of claims 1 to 10, characterized by the following monitoring steps: - before switching on the drum drive ( 2 ) is controlled by the central control unit ( 3 ) a control request signal to the electronic control unit ( 6 ), - by the electronic control unit ( 6 ) is then a current pulse via an electrical switch ( 10 ) including monitoring circuit for detecting the closed state of the lid ( 5 ), - the electronic control unit ( 6 ) detects a closed monitoring circuit, is sent to the central control unit ( 3 ) a start enable signal for the drum drive ( 2 ) Posted.

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