DE102012023272A1 - Adjustment device for axial piston machine of hybrid vehicle i.e. passenger car, has piston provided with return device and return pin, return spring connected with pivoting cradle, and return bolts and sleeve that are arranged in housing - Google Patents

Abstract

The device (1) has a pivoting cradle (12) provided with an actuating cylinder (6) and a counter-cylinder (4). An actuating chamber (24) of the actuating cylinder is fixed with a control valve (28). The control valve comprises a control oil source, and is connected to a control oil sink. A control piston (30) is provided with a return device (42) and a return pin. An intermediate return spring (38) is connected with the pivoting cradle. Return bolts and a fixed sleeve are arranged in a housing. A terminal plate is secured in a case.

Description

The invention relates to an adjusting device which is provided for adjusting the stroke volume of a hydraulic axial piston machine and which has the features according to the preamble of claim 1, and a hydraulic axial piston machine with such an adjusting device.

Such a hydraulic axial piston machine is for example from the DE 10 2008 038 435 A1 known. This axial piston machine has an engine with a plurality of axial pistons, which are guided within a cylinder drum and each define a working space therewith. Piston-foot-side end portions of the pistons are supported by sliding shoes on a pivoting cradle, the pivot angle is adjustable to adjust the delivery / absorption volume. This adjustment takes place via an adjusting device, with an actuating piston and an opposed piston. The actuating piston engages directly or indirectly on the pivoting cradle and acts on it in an adjustment direction; in the opposite direction, the counter-piston of a counter-cylinder acts. The adjusting device may further be provided with a spring arrangement, which ensures that the pivoting cradle occupies a basic position in the unpressurized state.

The counter-cylinder is acted upon by the pump or system pressure, so that the pivoting cradle is not swung when pump (stand-by), for example, to a minimum swing angle or fully swung and then can be swung out or back via a control of the actuating cylinder.

The actuation of the actuating cylinder via a control valve, via which a control chamber of the actuating cylinder with a control oil source or a control oil can be connected to actuate the actuating cylinder accordingly. The pivot angle of the pivoting cradle is fed back via a mechanical feedback device to the control valve, so that adjusts a pivot angle in a control position of the control piston, which is proportional to the force applied to the piston force. The control valve can be adjusted for example via a proportional solenoid, which thus acts against the force applied via the feedback device in such an EP adjustment.

In the JP 4523720 B2 an axial piston machine is shown, in which the return device has a pin which is guided in a housing of the axial piston machine and is in operative connection with a counter-spring, which in turn acts against a control piston of a control valve against the adjustment direction.

The disadvantage of this solution is that the integrated into the housing guide can be realized only with considerable effort. If, for example, the housing is produced by casting, the demolding of this guide causes considerable problems.

In contrast, the present invention seeks to provide an adjusting device for a hydraulic axial piston machine and a hydraulic axial piston machine, which allow a simplified production and / or assembly.

This object is achieved with respect to the adjusting device by the feature combination of claim 1 and in view of the axial piston machine by the features of claim 10.

Advantageous developments of the invention are the subject of the dependent claims.

According to the invention, the adjusting device has a pivoting cradle, which is acted upon by means of an actuating cylinder in one direction and preferably by means of a counter-cylinder in the other pivoting direction. A control chamber of the actuating cylinder can be connected via a control valve with a control oil source or a control oil well to adjust a control piston. The adjusting device further has a return device, which acts on the control piston. This feedback device has a return pin, which rests directly or indirectly on the pivoting cradle and is connected via a return spring with the control piston of the control valve in operative connection.

According to the invention, the return pin is guided in a sleeve which is fixed to the housing. The complex guide section is thus placed in the region of the sleeve, which can be fixed without considerable installation effort on the housing. It is particularly advantageous that a simple adjustment of the guide to different bolt geometries without changing the housing geometry is made possible, since only the sleeve must be adjusted. Such a solution can be compared to the prior art much easier to manufacture and assemble. In addition, the sleeve can be tribologically optimized, so that the friction of the bolt is minimized. It is particularly advantageous that the sleeve can be finished prior to installation and is installed later. In the described prior art, this fine machining must be done on the housing.

As already explained, it is particularly advantageous if the material of the sleeve is optimized with regard to the sliding guide.

The structure of the adjusting device is further simplified if the return spring dips into the sleeve and thus rests within the sleeve on the guide pin. In such an embodiment can be dispensed with a guide bolt side spring plate.

In one embodiment of the invention can also be dispensed with the rule piston-side spring plate, although the control piston is immersed in the sleeve, so that the entire return spring is received in the sleeve.

In a variant of the invention, it is provided to attach the sleeve to a connection plate of the control valve, so that the assembly is very easy, since the sleeve is mounted with the attachment of the connection plate.

The assembly cost is further reduced when the sleeve is pressed.

In an advantageous embodiment of the invention, it is provided to form the sleeve such that it represents a pivoting angle limit for the pivoting cradle.

The construction according to the invention makes it possible to form the control piston of the control valve as far as possible symmetrical.

The term "sleeve" does not necessarily mean a tubular body, but it may also be a component with any, adapted to the housing contour peripheral contour, which is designed with a guide for the guide pin.

The axial piston machine according to the invention is designed with an adjusting device in the sense of the above statements.

Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings.

Show it

1 a circuit diagram of an axial piston machine according to the invention,

2 a schematic diagram of a realized in the adjusting device according to the invention feedback device,

3 the return device according to 2 with pivoted swivel cradle and

4 a further embodiment of a return device of an adjusting device according to the invention.

According to the in 1 Schematics shown has an adjustment 1 for adjusting the delivery / absorption volume of an axial piston machine, in the present case an axial piston pump 2 , a counter-cylinder 4 and a positioning cylinder 6 , whose counter-piston 8th or actuator piston 10 on a pivoting cradle 12 attack. The opposing piston 8th delimits a chamber 14 that have a control line 16 with a pressure line leading to the system or pump pressure 18 connected is. A suction connection of the axial piston pump 2 is connected to a tank T. The opposing piston 8th is thus by the one in the chamber 14 acted upon effective pump pressure, against the force of a counter spring 20 acts in accordance with the illustration 1 the opposing piston 8th in the direction of pivoting the pivoting cradle 12 applied.

The diameter of the counter-piston 8th is lower than that of the actuator piston 10 executed. This is about a spring 22 in the sense of reducing the swivel angle of the swivel cradle 12 acted upon and thus acts on the pivoting cradle 12 against the opposing spring 20 , The two springs 20 . 22 are matched to one another such that when the pump is not running, the pivoting cradle is set to a predetermined basic position, which may correspond for example to a neutral position or the fully swung-out position or an intermediate position.

One from the actuator piston 10 limited control chamber 24 of the adjusting cylinder 6 is via a control channel 26 with the output port A of a proportionally adjustable control valve 28 connected. The adjustment of a control piston 30 This control valve is via two single-acting proportional solenoids 32 . 34 , In addition, the control piston 30 via a control spring 36 and a return spring 38 biased in the direction of its illustrated home position, in which the outlet port A and a feed port P throttled with a connected to the tank T tank port T are in fluid communication. The inlet connection P is via a channel 40 with the pressure line 18 connected so that at the entrance of the control valve 28 the pump or system pressure is applied. The pivoting movement of the pivoting cradle 12 is via a mechanical feedback device 42 on the return spring 38 transfer. In a control position of the control piston 30 the magnetic force applied by the driven magnet is in equilibrium with that via the feedback device 42 initiated drag.

When the proportional solenoid is energized 34 becomes the control piston 30 shifted to the right (view after 1 ), so that the pressure medium connection between the inlet port P and the outlet port A is opened and the connection to the port T is controlled and control oil into the control chamber 24 can flow in. When the magnet is switched off 34 and / or actuation of the magnet 32 a control oil connection from the output port A to the tank port T is opened and the control oil connection to the inlet port A is controlled, so that the control oil from the control chamber 24 can flow out to the tank T.

Constructive details of such an arrangement are in the prior art, for example in the DE 10 2008 038 435 A1 explained, so that reference can be made to the relevant statements for simplicity.

2 shows in a greatly simplified form a constructive design of the feedback device 42 , With the reference number 12 indicated is the pivoting cradle 12 , The control valve 28 is in a connection plate 44 the housing of the axial piston integrated, wherein the control piston 30 in a valve bore 46 is guided. A tank channel 48 as well as the control channel 26 and the channel 40 are at least partially in the connection plate 44 formed and open in the valve bore 46 , In the illustration according to 2 is used instead of the two single-acting proportional solenoids 32 . 34 a double-acting proportional solenoid 50 used, over which the control piston 30 is adjustable out of its illustrated basic or control position to the channels 26 . 28 respectively. 26 . 40 connect with each other and lock the other channel on the other hand. In the illustrated basic position, for example, a throttled connection of the connections P and A to the tank connection T should be present. In principle, of course, a blocking position can be taken.

The upward control takes place via two control edges 52 . 54 which are formed by two annular grooves.

The in 2 right end section 56 of the control piston 30 is in a manner not shown on the double-acting proportional magnet 50 coupled, so that the control piston 30 left or right (view after 2 ) is movable. The the control piston 30 in this area acting rule spring 36 is in the illustration according to 2 merely hinted.

At the opposite end portion of the control piston 30 grips the return spring 38 in turn on a return bolt 58 acts, in the illustrated embodiment, directly to the pivoting cradle 12 attacks. This is in the illustration according to 2 set to a neutral position (minimum delivery volume). This neutral position is assumed, for example, when the control valve 28 is not driven and the pump is running in stand-by mode, so in the parking chamber 14 a signal pressure of for example 30 bar is applied, which is sufficient, the pivoting cradle 12 to swing from the fully swung-out position in the illustrated neutral position. The return spring 38 and the return bolt 58 are in a sleeve according to the invention 60 that resulted in a recording 62 the connection plate 44 is used.

The sleeve 60 is here tubular, but the invention is not limited to such a geometry.

In the illustrated embodiment, the sleeve 60 coaxial with the control piston 30 arranged, taking the picture 62 a radial extension of the valve bore 46 is. The connection can, for example, by pressing the sleeve 60 in the connection plate 44 respectively. Of course, a cohesive connection, a non-positive or a positive connection, eg. By screwing, gluing, welding, clamps or the like done.

The material of the sleeve 60 is optimized for minimizing friction and for maximum wear resistance and machinability. The sleeve according to the invention 60 can easily before inserting into the receptacle 62 be finished, so that the processing cost is minimal. Because the return spring 38 completely in the sleeve 60 can be accommodated on spring plate in the contact area on the guide pin 58 and to the control piston 30 be waived. The sleeve 60 can also be stepped, so that a larger spring can be used with the same guide pin diameter.

From the illustrated stand-by position of the pivoting cradle 12 can by energizing the proportional magnet 50 or the single-acting proportional solenoid 34 in 1 Control oil in the control chamber 24 be initiated so that the actuator piston 10 against the force of the spring 22 extends and the pivoting cradle 12 swings. This pivoting movement takes place against the force of the opposing piston 8th and is about the return device 42 , in the present case the guide pin 58 and the return spring 38 on control piston 30 so that it assumes a control position when the forces acting on it are balanced.

This position is in the illustration according to 3 shown. The pivoting cradle 12 is swung out, with the return bolt 58 in the sleeve 60 pushed in and according to the return spring 38 is compressed. The resulting spring force then acts on the control piston 30 against the force of the proportional magnet 50 and against the force of the control spring 36 , Here, the maximum swivel angle is by running the swivel cradle 12 on the face 64 the sleeve 60 limited. In principle, on the sleeve 60 also a stop for the guide pin 58 be provided so that then the swivel angle limit by cooperation of the guide pin 58 with the sleeve 60 he follows.

4 shows a variant of the return device 42 , wherein a stronger return spring 38 is provided, which has a larger diameter than the above-described return spring 38 according to 3 Has. In this embodiment, the sleeve is relatively short 60 in a suitable manner by frictional connection, positive connection and / or material connection on the indicated housing 66 attached to the axial piston machine, on which also said connection plate 44 is fixed, which thus forms a part of the housing. The sleeve 60 only serves as a guide for the return bolt 58 , the bilateral from the sleeve 60 protrudes. The in 4 left end section is in turn on the pivoting cradle 12 at. At the other end portion is a first spring plate 68 provided on which the return spring 38 which in turn has a second spring plate 70 on the control piston 30 is supported. The diameter of the spring plate 68 . 70 is significantly larger than that of the guide pin 58 and the control piston 30 , Also in this embodiment, the end face 64 the sleeve 60 as swivel angle limitation for the swivel cradle 12 serve. The spring plates 68 and 70 can be of identical shape.

Otherwise, this corresponds to 4 illustrated embodiment of the embodiment described above, so that further explanations are unnecessary.

Disclosed are an adjusting device and an axial piston machine designed therewith, in which the return of a pivoting angle of a pivoting cradle to a control piston of a control valve via a return bolt, which is guided in a sleeve which is fixed on the housing side.

The invention is also particularly applicable in so-called hybrid vehicles, for example in a passenger car, with an internal combustion engine and a hydraulic drive train including hydraulic pump, hydraulic accumulator and one or more hydraulic motors between the engine and an axle. A hydraulic pump or a hydraulic motor can be designed according to the invention.

LIST OF REFERENCE NUMBERS

1

adjustment

2

axial piston pump

4

opposing cylinder

6

actuating cylinder

8th

opposed piston

10

actuating piston

12

pivoting cradle

14

chamber

16

control line

18

pressure line

20

against spring

22

spring

24

setting chamber

26

control channel

28

control valve

30

control piston

32

magnet

34

magnet

36

control spring

38

Return spring

40

channel

42

Return means

44

connecting plate

46

valve bore

48

tank channel

50

Proportional magnet double acting

52

control edge

54

control edge

56

End portion of the control piston

58

Feedback pin

60

shell

62

admission

64

face

66

casing

68

first spring plate

70

second spring plate

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

• DE 102008038435 A1 [0002, 0031]
• JP 4523720 B2 [0005]

Claims (9)

Adjusting device for an axial piston machine, with a pivoting cradle ( 12 ), which by means of an actuating cylinder ( 6 ) at least in one direction and preferably by means of a counter-cylinder ( 4 ) is acted upon in the other pivoting direction, wherein a control chamber ( 24 ) of the adjusting cylinder ( 6 ) via a control valve ( 28 ) is connectable to a control oil source or a control oil well whose control piston ( 30 ) via a return device ( 42 ) with a return bolt ( 58 ) and an intermediate return spring ( 38 ) in operative connection with the pivoting cradle ( 12 ), characterized in that the return bolt ( 58 ) in a sleeve fixed to the housing ( 60 ) is guided. Adjusting device according to claim 1, wherein the sleeve material is optimized with a view to minimizing the friction. Adjusting device according to claim 2, wherein the return spring ( 38 ) in the sleeve ( 60 ) and in this on the guide pin ( 58 ) is present. Adjusting device according to claim 3, wherein the control piston ( 30 ) in the sleeve ( 60 immersed). Adjusting device according to one of the preceding claims, wherein the sleeve ( 60 ) on a connection plate ( 44 ) is attached. Adjusting device according to one of the preceding claims, wherein the sleeve ( 60 ) is pressed in on the housing side. Adjusting device according to one of the preceding claims, wherein the sleeve ( 60 ) as a stop for pivoting angle limitation of the pivoting cradle ( 12 ) serves. Adjusting device according to one of the preceding claims, wherein the control piston ( 30 ) is formed largely symmetrical. Axial piston machine with an adjusting device according to one of the preceding claims.

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