WO2020240952A1

WO2020240952A1 - Transfer

Info

Publication number: WO2020240952A1
Application number: PCT/JP2020/007762
Authority: WO
Inventors: 木村　淳; 小林　正幸
Original assignee: 株式会社Ｉｊｔｔ
Priority date: 2019-05-30
Filing date: 2020-02-26
Publication date: 2020-12-03
Also published as: JP2020193696A

Abstract

Provided is a transfer capable of preventing deterioration of responsiveness.　A transfer 1 comprises a multiplate clutch 11 provided in a drive system to distribute driving force, an actuator 12 for driving the multiplate clutch 11, and a control device 34 for controlling the actuator 12, wherein the actuator 12 includes a pressing part 25 that presses clutch plates 20, 21 of the multiplate clutch 11, and the control device 34, when switching the multiplate clutch 11 from a connected state to a disconnected state, controls the actuator 12 in such a manner that the pressing part 25 separates from the multiplate clutch 11 in the connected state by a predetermined distance x.

Description

transfer

This disclosure relates to the transfer provided in the drive system.

As the transfer, those described in Patent Documents 1 and 2 are known. This type of transfer includes a multi-plate clutch, a pressing portion that presses the multi-plate clutch when the multi-plate clutch is engaged and is separated from the multi-plate clutch when the disengagement is performed, and a motor that drives the pressing portion. ..

Republished WO2008 / 096438 Japanese Unexamined Patent Publication No. 2011-89610

By the way, in the above-mentioned type of transfer, when the multi-plate clutch is disengaged from contact, the pressing portion is moved to a predetermined standby position to separate it from the multi-plate clutch. For this reason, if the assembly accuracy of the multi-plate clutch varies, or if the multi-plate clutch is worn, the distance from the standby position to the clutch contact position will not be constant, and the responsiveness at the start (from the transfer cutoff). Responsiveness when contacting) may deteriorate.

Therefore, this disclosure was devised in view of such circumstances, and its purpose is to provide a transfer capable of suppressing deterioration of responsiveness.

According to one aspect of the present disclosure
A multi-plate clutch provided in the drive system for distributing the driving force, an actuator for driving the multi-plate clutch, and a control device for controlling the actuator are provided.
The actuator includes a pressing portion that presses the clutch plate of the multi-plate clutch.
The control device is characterized in that when the multi-plate clutch is switched from contact to disconnect, the transfer controls the actuator so that the pressing portion is separated from the contacted multi-plate clutch by a preset distance. Provided.

Preferably, when the engine of the vehicle to which the transfer is applied is started, the control device engages the multi-plate clutch and then switches to disconnection.

Preferably, the actuator comprises a drive device comprising a DC motor with an encoder, a servomotor or a stepping motor.
When the multi-plate clutch is switched from contact to disconnection, the control device rotates the drive device in a direction opposite to that when the multi-plate clutch is switched from contact to contact by a preset angle.

According to the above aspect, deterioration of responsiveness can be suppressed.

It is the schematic top view of the vehicle to which the transfer which concerns on one Embodiment of this disclosure is applied. It is sectional drawing of the transfer. It is an enlarged view of the main part of FIG. It is sectional drawing which cut the cam part at the time of disengagement of a clutch at the position of line AA of FIG. It is sectional drawing which cut the cam part at the time of clutch engagement at the position of line AA of FIG. It is explanatory drawing which looked at the cam part and the actuator in the direction of an arrow from the position of line BB of FIG. It is an enlarged view of the main part of FIG. It is a graph explaining the variation of the response time of the conventional transfer. It is a graph explaining the variation of the response time of the transfer which concerns on this embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In addition, each direction in the embodiment described later refers to each direction of the vehicle to which the transfer according to the present embodiment is applied. However, it should be noted that each of these directions is merely defined for convenience of explanation and represents the relative positional relationship between the members.

FIG. 1 is a schematic top view of the vehicle C to which the transfer 1 according to the present embodiment is applied.

As shown in FIG. 1, in the present embodiment, the vehicle C is an AWD (All Wheel Drive) vehicle based on an FR vehicle (front engine / rear drive vehicle). The rotational driving force from the engine E mounted on the front portion of the vehicle is transmitted to the propeller shaft 2 via the transmission T / M and the transfer 1. The rotational driving force transmitted to the propeller shaft 2 is transmitted to the rear wheels 4a via a differential gear (not shown) housed in the differential case 3. Further, the transfer 1 is configured to selectively distribute and transmit the rotational driving force from the transmission T / M to the input shaft 5 of the differential gear for driving the front wheels. That is, the front wheel 4b becomes a driving wheel when the driving force is transmitted from the transfer 1 to the input shaft 5, and becomes a driven wheel when the driving force is not transmitted to the input shaft 5.

FIG. 2 is a top sectional view of the transfer 1. FIG. 3 is an enlarged view of a main part of FIG. As shown in FIGS. 2 and 3, the transfer 1 includes a housing 6 attached to the transmission T / M, a first shaft 7 rotatably provided in the housing 6, and an inner rotating member provided on the first shaft 7. 8 and a multi-plate that connects the first sprocket 9 rotatably provided on the first shaft 7, the outer rotating member 10 provided on the first sprocket 9, and the inner rotating member 8 to and from the outer rotating member 10. It includes a clutch 11, an actuator 12 that drives the multi-plate clutch 11, and a control device 34 that controls the actuator 12.

Further, the transfer 1 includes a second shaft 13 rotatably provided in the housing 6, a second sprocket 14 provided on the second shaft 13, and a chain 15 hung around the first sprocket 9 and the second sprocket 14. And further prepare. The second shaft 13 is connected to the input shaft 5 of the differential gear for driving the front wheels.

The front end of the first shaft 7 is connected to the output shaft (not shown) of the transmission T / M. Further, the rear end portion of the first shaft 7 is connected to the propeller shaft 2. The inner rotating member 8 is formed in a tubular shape substantially coaxial with the first shaft 7. An outer peripheral spline 16 is formed on the outer peripheral surface of the inner rotating member 8. The outer rotating member 10 has a disk portion 17 arranged between the first sprocket 9 and the inner rotating member 8 extending outward in the radial direction, and an outer cylinder portion 18 formed extending rearward from the outer peripheral end of the disk portion 17. And. The outer cylinder portion 18 is arranged so as to cover the outer periphery of the outer peripheral spline 16. An inner peripheral spline 19 is formed on the inner peripheral surface of the outer cylinder portion 18. That is, the outer peripheral spline 16 and the inner peripheral spline 19 face each other in the radial direction.

The multi-plate clutch 11 includes an annular first clutch plate 20 that is spline-fitted to the outer peripheral spline 16 and an annular second clutch plate 21 that is spline-fitted to the inner peripheral spline 19. The first clutch plate 20 and the second clutch plate 21 are alternately arranged in the front-rear direction. Further, a clutch receiving portion 22 for receiving the multi-plate clutch 11 is formed on the inner rotating member 8 in front of the multi-plate clutch 11.

As shown in FIGS. 3, 4, 5, and 6, the actuator 12 is interposed between the cam mechanism 23, the drive device 24 for driving the cam mechanism 23, the cam mechanism 23, and the multi-plate clutch 11. A pressing portion 25 is provided.

The cam mechanism 23 includes a fixed cam block 26 fixed to the housing 6, a movable cam block 27 disposed in front of the fixed cam block 26, and a ball disposed between the fixed cam block 26 and the movable cam block 27. 28 and a thrust bearing 29 provided on the front surface of the movable cam block 27 are provided.

The fixed cam block 26 is formed in an annular shape having an inner diameter larger than the outer diameter of the first shaft 7 and in a plate shape. The fixed cam block 26 is arranged coaxially with the first shaft 7. Further, a plurality of fixed cam grooves 30 for accommodating the rear portion of the ball 28 are formed on the front surface of the fixed cam block 26. The fixed cam groove 30 is formed in an arc shape coaxial with the first shaft 7. The fixed cam groove 30 is formed so that the center in the circumferential direction is the deepest and the fixed cam groove 30 becomes shallower toward both ends. Further, the plurality of fixed cam grooves 30 are arranged at equal intervals in the circumferential direction.

The movable cam block 27 includes a facing portion 27a that faces the fixed cam block 26 in the axial direction, and a lever portion 27b that extends outward in the radial direction from the facing portion 27a.

The facing portion 27a is formed in a shape symmetrical with respect to the fixed cam block 26. That is, the facing portion 27a is formed in an annular shape having an inner diameter larger than the outer diameter of the first shaft 7 and in a plate shape. The facing portion 27a is arranged coaxially with the first shaft 7. On the rear surface of the movable cam block 27, a movable cam groove 31 having a shape and arrangement symmetrical with the fixed cam groove 30 is formed. Specifically, the movable cam groove 31 accommodates the front portion of the ball 28, and is formed in an arc shape coaxial with the first shaft 7. The movable cam groove 31 is formed so that the center in the circumferential direction is the deepest and the movable cam groove 31 becomes shallower toward both ends. Further, the plurality of movable cam grooves 31 are arranged at equal intervals in the circumferential direction. The distance between the movable cam grooves 31 adjacent to each other in the circumferential direction is the same as the distance between the fixed cam grooves 30 adjacent to each other in the circumferential direction.

The lever portion 27b is formed in a fan shape centered on the central axis CA of the first shaft 7. On the outer peripheral surface of the lever portion 27b, teeth 32 that mesh with the worm gear 33 described later are formed. That is, the movable cam block 27 constitutes a sector gear (fan-shaped gear) that rotates around the central axis CA. The fixed cam groove 30 and the movable cam groove 31 are not limited to this. For example, the fixed cam groove 30 may be formed so that one end in the circumferential direction is the deepest and the fixed cam groove 30 becomes shallower toward the other end. In this case, the movable cam groove 31 may be formed so as to be asymmetrical with the fixed cam groove 30, that is, one end in the circumferential direction is the shallowest and the movable cam groove 31 becomes deeper toward the other end.

The pressing portion 25 is interposed between the thrust bearing 29 and the multi-plate clutch 11. The pressing portion 25 includes a plate portion 25a formed in an annular shape having an inner diameter larger than the outer diameter of the first shaft 7 and formed in a plate shape, and a pad portion 25b provided on the plate portion 25a. The pad portion 25b is composed of a thrust bearing and is arranged close to the multi-plate clutch 11. Further, a spring 35 for pressing the plate portion 25a rearward is provided between the plate portion 25a and the inner rotating member 8. The spring 35 is composed of a coil spring and is provided between the plate portion 25a and the inner rotating member 8 in a compressed state. The spring force of the spring 35 is set to a weak force that allows the pressing portion 25 to follow the movable cam block 27 when it is moved rearward by the driving force from the driving device 24. The pressing portion 25 is not limited to this. For example, the plate portion 25a of the pressing portion 25 may be formed integrally with the movable cam block 27.

The drive device 24 is composed of a DC motor with an encoder. A worm gear 33 is provided on the drive shaft 24a of the drive device 24. The worm gear 33 meshes with the teeth 32 of the movable cam block 27. The drive device 24 is not limited to this. The drive device 24 may be configured as long as the rotation angle can be controlled by the control device 34 described later, and may be composed of, for example, a stepping motor or a servomotor.

The control device (ECU: Electronic Control Unit) 34 controls the drive device 24. The control device 34 controls the drive device 24 so that the multi-plate clutch 11 is brought into contact with the vehicle when the angular velocity difference between the rear wheels 4a and the front wheels 4b becomes equal to or higher than a preset upper limit value. The rotation of the drive device 24 at this time is set to forward rotation for convenience. As a result, the driving force can be transmitted not only to the rear wheels 4a but also to the front wheels 4b on a slippery road surface such as a snowy road, and the vehicle C can be all-wheel drive (AWD).

Further, the control device 34 reversely rotates the drive device 24 to disengage the multi-plate clutch 11 when the angular velocity difference between the rear wheels 4a and the front wheels 4b becomes equal to or less than a preset lower limit value. As a result, the front wheel 4b can be used as a driving wheel on a non-slip road surface.

Further, when the drive device 24 is rotated forward and reverse, the control device 34 rotates the drive device 24 at a constant speed. This speed is set to a maximum speed that is generally determined by various conditions such as the drive device 24 and the power supply (not shown). As a result, the multi-plate clutch 11 is quickly engaged and disconnected.

However, in the conventional transfer (not shown), the position of the pressing portion in the front-rear direction (hereinafter referred to as the standby position) when the multi-plate clutch is disengaged is a fixing mechanism such as a housing (the multi-plate clutch is not included). Is constant against. Therefore, if the assembly accuracy of the multi-plate clutch varies, or if the multi-plate clutch is worn, the distance from the standby position to the clutch contact position is not constant. Therefore, the distance from the standby position to the multi-plate clutch may be longer than the design value. In this case, as shown in FIG. 8, the time T2 from the standby position until the pressing portion 25 reaches the multi-plate clutch becomes longer than the expected time T1 by ΔT, and the responsiveness of the transfer deteriorates. The transfer responsiveness can be improved by using a highly accurate clutch, but the manufacturing cost increases.

Therefore, in the transfer 1 according to the present embodiment, when the multi-plate clutch 11 is switched from contact to disconnection, the pressing portion 25 is separated from the multi-plate clutch 11 in the contact state by a preset distance x (see FIG. 7). Controls the drive device 24 of the actuator 12. Specifically, when the multi-plate clutch 11 is switched from contact to disconnection, the control device 34 of the transfer 1 reversely rotates the DC motor with an encoder, which is the drive device 24, by a preset angle θ. As a result, the distance x from the multi-plate clutch 11 to the standby position becomes constant regardless of variations in assembly accuracy of the multi-plate clutch 11 and wear of the multi-plate clutch 11. Therefore, as shown in FIG. 9, the time T2 from the standby position until the pressing portion 25 reaches the multi-plate clutch 11 can be made the same as the desired time T1, and the response time of the transfer 1 can be made constant. .. Then, the response time of the transfer 1 can be made constant without using the highly accurate multi-plate clutch 11, and the responsiveness of the transfer 1 can be improved while suppressing the manufacturing cost of the transfer 1.

Further, when the engine E is started, the control device 34 engages the multi-plate clutch 11 and then switches to disconnection. That is, after the multi-plate clutch 11 is brought into contact with the multi-plate clutch 11 for a moment, the control device 34 reversely rotates the drive device 24 by an angle θ. As a result, the pressing portion 25 can be moved to the standby position (a position separated from the multi-plate clutch 11 by a distance x) in advance before the vehicle C starts traveling.

Next, the operation of this embodiment will be described.

When the engine E is started, the control device 34 rotates the drive device 24 in the forward direction. As a result, the movable cam block 27 is rotated in the clutch contact direction (counterclockwise in FIG. 6). As shown in FIG. 4, when the ball 28 is in a relatively deep position of the fixed cam groove 30 and the movable cam groove 31 before the engine is started, the ball 28 moves to a relatively shallow position as shown in FIG. Will be done. As a result, the movable cam block 27 is moved forward to move the pressing portion 25 forward. The pressing portion 25 moved forward presses the multi-plate clutch 11 forward. As a result, the first clutch plate 20 and the second clutch plate 21 are sandwiched between the pressing portion 25 and the clutch receiving portion 22 and are in contact with each other, and the pressing portion 25 is restricted from moving forward.

After that, the control device 34 reversely rotates the drive device 24 by a preset angle θ. As a result, the pressing portion 25 is moved rearward from the multi-plate clutch 11 by a distance x (see FIG. 7) according to the angle θ. That is, the position separated rearward by the distance x from the multi-plate clutch 11 serves as the standby position of the pressing portion 25, and the pressing portion 25 is positioned.

After that, when the vehicle C is driven and the angular velocity difference between the rear wheels 4a and the front wheels 4b becomes equal to or more than the upper limit value, the control device 34 rotates the drive device 24 in the forward direction. As a result, the movable cam block 27 and the pressing portion 25 are moved forward to bring the multi-plate clutch 11 into contact. At this time, the pressing portion 25 reaches the multi-plate clutch 11 by moving forward by a distance x. Therefore, the time from when the control device 34 starts driving the drive device 24 until the pressing portion 25 reaches the multi-plate clutch 11 is a constant time according to the rotation speed and the distance x of the drive device 24.

After that, when the vehicle C is further driven and the angular velocity difference between the rear wheels 4a and the front wheels 4b becomes equal to or less than the lower limit value, the control device 34 reversely rotates the drive device 24 by a preset angle θ. As a result, the pressing portion 25 is moved rearward from the multi-plate clutch 11 by a distance x (see FIG. 7) according to the angle θ.

After that, the above control is repeated according to the difference in angular velocity between the rear wheels 4a and the front wheels 4b.

In this way, when the multi-plate clutch 11 is switched from contact to disconnect, the control device 34 controls the actuator 12 so that the pressing portion 25 is separated from the multi-plate clutch 11 in the contact state by a preset distance x. Therefore, the position separated from the multi-plate clutch 11 by the distance x is set as the standby position of the pressing portion 25, and the time until the pressing portion 25 in the standby position reaches the multi-plate clutch 11 is made constant. It is possible to suppress deterioration of responsiveness due to variation and wear of the multi-plate clutch 11. In other words, the standby position can be updated according to the variation and wear of the multi-plate clutch 11.

Further, when the engine E of the vehicle C to which the transfer 1 is applied is started, the control device 34 engages the multi-plate clutch 11 and then switches to disconnection. As a result, even if the drive device 24 rotates and the standby position shifts for some reason while the engine E is stopped, the standby position can be returned to the original appropriate position when the engine is started. Then, the responsiveness of the transfer 1 can be improved immediately after the engine is started.

Although the embodiments of the present disclosure have been described in detail above, the present disclosure may also include the following other embodiments.

(1) When the engine E is started, the control device 34 controls the multi-plate clutch 11 to be engaged and then switched to disconnect, but this control may be omitted. This is because even if the standby position shifts while the engine is stopped, the standby position can be returned to the original appropriate position once the multi-plate clutch 11 is engaged and disengaged after the engine is started.

(2) The drive device 24 is provided with a worm gear 33, but the present invention is not limited to this. The drive device 24 may be provided with a spur gear (not shown) instead of the worm gear 33. By doing so, the drive device 24 is likely to rotate while the engine E is stopped, and the standby position is likely to shift. However, the shift can be eliminated by engaging and disengaging the multi-plate clutch 11 when the engine is started.

(3) In the above-described embodiment, the transfer 1 applied to the FR vehicle-based AWD has been described, but the present invention is not limited to this. For example, the transfer 1 may be applied to an AWD based on an FF vehicle. Further, although the multi-plate clutch 11 of the transfer 1 is provided on the propeller shaft 2, it may be provided on another drive system.

The configurations of the above-described embodiments can be partially or wholly combined unless there is a particular contradiction. The embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications, applications, and equivalents included in the ideas of the present disclosure defined by the scope of claims are included in the present disclosure. Therefore, this disclosure should not be construed in a limited way and can be applied to any other technique that belongs within the scope of the ideas of this disclosure.

Claims

A multi-plate clutch provided in the drive system to distribute the driving force, an actuator for driving the multi-plate clutch, and a control device for controlling the actuator are provided.
The actuator includes a pressing portion that presses the clutch plate of the multi-plate clutch.
The control device is a transfer that controls the actuator so that when the multi-plate clutch is switched from contact to disconnect, the pressing portion is separated from the contacted multi-plate clutch by a preset distance.
The transfer according to claim 1, wherein the control device switches to disengagement after engaging the multi-plate clutch when the engine of the vehicle to which the transfer is applied is started.
The actuator includes a drive device including a DC motor with an encoder, a servo motor, or a stepping motor.
The control device claims that when the multi-plate clutch is switched from contact to disengagement, the drive device is rotated by a preset angle in a direction opposite to that when the multi-plate clutch is switched from contact to disengagement. The transfer according to 1 or 2.