DE102008040206A1 - Form-fitting clutch arrangement for use in power train of vehicle, has clutch part held in engaged condition as resting position over fork, where clutch part is movable over actuator against spring action of fork in disengaged condition - Google Patents

Abstract

The arrangement has a driven clutch part (1) e.g. shift collar (5), and a driving clutch part (2) movable by an axial movement between an engaged condition and a disengaged condition. The axial movement is realizable by a spring-tensioned shift fork (6) and an actuator. One of the clutch parts is held in the engaged condition as a resting position over the pretensioned shift fork. The driven clutch part is movable over the actuator against a spring action of the pretensioned shift fork in the disengaged condition. The shift fork is coaxially arranged at an actuating piston (9).

Description

The The present invention relates to a positive coupling arrangement for a transfer case and / or a differential, in particular for activating and deactivating a differential lock and / or an all-wheel drive, in a drive train of a vehicle according to the preamble of claim 1 closer defined type.

For example, from the document EP 0 510 457 B1 is known a positive clutch for a transfer case and a differential gear of motor vehicles and a method for the actuation thereof. Trained as a dog clutch clutch assembly consists of a driving coupling part, which communicates with the drive train and a Radantriebsstrang and a driven coupling part which is connected to a wheel drive train to be activated and is designed as a sliding sleeve to be moved via an engaging member by means of a shift fork , The engagement member includes a piston having a piston rod and a fluid cylinder. At the front end of the piston rod, the shift fork is attached. The piston is acted upon only on one side with fluid and on the other side, a compression spring is supported. In the rest position, the shift fork is pressed by the compression spring to the left and brings the clutch in a retracted state. The disengaged state of the coupling is achieved by the piston rod is moved to the right by a corresponding pressurization until the coupling parts are positively connected with each other.

Furthermore, from the document DE 103 34 450 A1 a positive clutch for transfer case and differential for vehicles known. The known clutch is actuated by a double-acting shift cylinder. In this case, during the engagement process of the clutch or the differential lock of the shift cylinder is controlled such that the lock is moved almost without drag in the locked position, ie in the engaged state of the clutch. The counterforce, which allows the automatic disengagement, is achieved only by completion of the engagement process by pressurizing the other side of the cylinder.

If for example, the vehicle is parked in an inclined position, The wheels of the left and right side of the vehicle can over the transverse and / or longitudinal differential relative to each other rotate. To prevent this, the insertion of a differential lock should ensured when parking a vehicle with built-in parking brake on the transmission output become. Usually, this should be a so-called failsafe solution be used. This would have a pressure-free state Lock operation done. This can be done with the known coupling can not be realized because they are in the pressure-free state in disengaged position, ie in unlocked position the clutch or the lock is located.

Of the The present invention is based on the object, a clutch assembly to propose the genus described in the introduction, which additionally the lock function for the parking brake device in Drive train of the vehicle supported.

These Task is solved by the features of claim. Further advantageous embodiments will be apparent from the dependent claims and the drawings.

Therefore is a positive coupling arrangement for a transfer case and / or a differential gear, in particular to enable and disable a differential lock and / or a All-wheel drive in a drive train of a vehicle with at least a driven clutch part and with at least one driving Proposed coupling part, wherein the coupling parts by axial Movement between an engaged state and a disengaged state are movable and wherein the axial Movement by a spring-loaded shift fork or the like and an actuator is realized. According to the invention the driven coupling part in the engaged or locked state as rest position over the prestressed Shift fork are held, the driven coupling part if necessary or optionally via the actuator against the spring force the preloaded shift fork in the disengaged respectively unlocked state is movable.

On this way can with the inventively proposed Coupling arrangement in the rest position, ie in the pressure-free state the differential lock operation or the four-wheel operation stay activated. This can be done simultaneously in an advantageous manner the lock function for the parking brake management in the frame the initially described safety aspect can be realized.

At the Vehicle can be a vehicle with conventional steering Front wheels or to act on a articulated vehicle.

As part of a possible embodiment of the invention can be provided that is provided as an actuator, a switching cylinder or the like with a pressurizable via a valve pressure chamber. In the pressure chamber is an actuating piston or the like chen guided guided on which the preloaded shift fork is supported. There are also other structural design conceivable to bring the clutch in the engaged state by the shift fork in the rest position. As pressure medium, any suitable medium can be used.

Preferably the shift fork can be arranged coaxially with the actuating piston be. The actuating piston can, for example, on a held in a housing of the shift cylinder rod or the like. The formed in the shift cylinder Pressure chamber, for example, by a closing the housing Lid be formed. The lid can, for example, a pressure medium supply include, connected to a valve for supplying pressure medium is. As a valve can z. B. 3/2-way valve or the like used become.

It it is also possible to turn the shift fork to store, on the one hand, the actuating piston and on the other the coupling is articulated and the shift fork around the fulcrum rotates.

A possible embodiment of the invention can provide that the form-locking coupling arrangement as Claw clutch or the like is formed, this one driven coupling part and driving coupling part comprises. It Other positive clutch arrangements are also usable.

If the coupling arrangement according to the invention for activating and deactivating an all-wheel drive is used, for example, the driven coupling part as on a Vorderachsantriebswelle axially be slidably mounted and rotatably mounted shift sleeve, which for axial displacement with the shift fork on any Way is coupled. The driving coupling part can with be connected to a drive shaft of the drive train. For example can be provided that the driving coupling part constantly is coupled to a rear axle drive shaft or the like. Other arrangements are possible.

The According to the invention proposed coupling arrangement can also enable and disable a differential lock for example, an intermediate differential or a transverse lock used become. There are also other fields of application of the invention Coupling arrangement possible.

following The invention will be explained in more detail with reference to the drawings. Show it:

1 a sectional view of a possible embodiment of a clutch assembly according to the invention in an engaged state as a rest position;

2 a sectional view of the clutch assembly with beginning pressurizing agent still in the engaged state; and

3 a sectional view of the clutch assembly with pressurizing in the disengaged state.

In the 1 to 3 a possible embodiment of a clutch assembly according to the invention is exemplified, wherein the clutch assembly is shown in various states.

The inventive coupling arrangement is z. B. Part of a not further illustrated transfer case or differential gear in a drive train of a vehicle. The coupling arrangement For example, you can enable and disable a differential lock and / or an all-wheel drive are used.

The exemplary designed as a dog clutch clutch assembly comprises a driven coupling part 1 and a driving coupling part 2 , Which have at the mutually facing areas a claw toothing or the like, which engage positively in the engaged state of the Kupplungsanord arrangement. The driving coupling part 2 is with a drive shaft 3 connected to a drive train not shown. The driven coupling part 1 is rotatably but axially displaceable on a Vorderachsantriebswelle 4 as a shift sleeve 5 stored and is with a shift fork 6 coupled for axial movement.

The sliding sleeve 5 is via an actuator and the shift fork 6 operated to move the clutch assembly between the engaged or locked state and the disengaged or unlocked state. As actuator is a switching cylinder 7 provided with the shift fork 6 is coupled. The shift cylinder 7 includes a housing 8th by an actuating piston 9 movable on a guide rod 15 is held. The actuating piston 9 is over a pressure room 10 subjected to a pressure medium. The pressure room 10 is through that with a lid 11 closed housing 8th educated. The lid 11 has a pressure medium supply 12 on which with a 3/2-way valve 13 connected to the pressure medium supply.

The shift fork 6 is coaxial with the actuating piston 9 of the shift cylinder 7 arranged, with the shift fork 6 via a compression spring 14 ge conditions the actuating piston 9 is pressed. In this way, the actuating piston is located 9 in the rest position with the shift fork 6 right at the stop. The rest position, which corresponds to the engaged or locked state of the clutch assembly is in 1 shown. In this state, the pressure chamber 10 pressure-free. If the clutch assembly is used to actuate an intermediate differential, not shown, the differential lock can be activated in the rest position, so that so that the parking brake management is supported and the otherwise required components for the realization of the lock function are not needed.

In 2 the clutch assembly is also shown in the engaged or locked state. However, it is just through the directional control valve 13 Pressure medium in the pressure chamber 10 of the shift cylinder 7 supplied and a corresponding pressure on the actuating piston 9 exercised.

3 then shows the clutch assembly in the disengaged state by the actuating piston 9 against the spring force of the compression spring 14 the shift fork 6 located on the left, so that too with the shift fork 6 connected shift sleeve 5 has been moved to the left, so that the two coupling parts 1 . 2 no longer engaged.

1

driven coupling part

2

driving coupling parts

3

drive shaft

4

Vorderachsantriebswelle

5

shift sleeve

6

shift fork

7

switching cylinder

8th

casing

9

actuating piston

10

pressure chamber

11

cover

12

Pressure medium feed

13

way valve

14

compression spring

15

guide rod

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0510457 B1 [0002]
• - DE 10334450 A1 [0003]

Claims (8)

Positive coupling arrangement for a transfer case and / or a differential, in particular for activating and deactivating a differential lock and / or an all-wheel drive, in a drive train of a vehicle, with a driven coupling part ( 1 ) and with a driving coupling part ( 2 ), wherein the coupling parts ( 1 . 2 ) are movable by axial movement between an engaged state and a disengaged state, and wherein the axial movement by a spring-loaded shift fork ( 6 ) and an actuator is realized, characterized in that one of the coupling parts ( 1 ) in the engaged state as a rest position on the preloaded shift fork ( 6 ) and this driven coupling part ( 1 ) optionally via the actuator against the spring force of the biased shift fork ( 6 ) is movable in the disengaged state. Coupling arrangement according to Claim 1, characterized in that a switching cylinder ( 7 ) with one via a valve ( 13 ) can be acted upon by a pressure medium pressure chamber ( 10 ) is provided, in which an actuating piston ( 9 ) is movably guided on which the preloaded shift fork ( 6 ) is supported. Coupling arrangement according to claim 2, characterized in that the shift fork ( 6 ) coaxial with the actuating piston ( 9 ) is arranged. Coupling arrangement according to claim 2 or 3, characterized in that the pressure chamber ( 10 ) by a with a lid ( 11 ) closed housing ( 8th ) is formed. Coupling arrangement according to claim 4, characterized in that the cover ( 11 ) a pressure medium supply ( 12 ) with a 3/2-way valve ( 13 ) connected is. Coupling arrangement according to one of the preceding claims, characterized in that the driven coupling part ( 1 ) than on a front axle drive shaft ( 4 ) axially displaceable and non-rotatably mounted shift sleeve ( 5 ) is formed, which for axial displacement with the shift fork ( 6 ) is coupled. Coupling arrangement according to one of the preceding claims, characterized in that the driving coupling part ( 2 ) with a drive shaft ( 3 ) of the drive train is connected. Coupling arrangement according to one of the preceding claims, characterized in that the driven coupling part ( 1 ) as on a Hinterachsantriebswelle axially displaceable and non-rotatably mounted shift sleeve ( 5 ) is formed, which for axial displacement with the shift fork ( 16 ) is coupled.