JP2013221540A - Driving force transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving force transmission device in which cost can be reduced in more simplified configuration while using a hydraulic pump.SOLUTION: A driving force transmission device 1 includes: a cylindrical outer rotary member 10; an inner rotary member 20 which is disposed coaxially within the outer rotary member 10 to be relatively rotatable; a main clutch 30 which transmits torque between the outer rotary member 10 and the inner rotary member 20; a piston 40 capable of pressing the main clutch 30; a hydraulic pump 50 which presses the piston 40 to the side of the main clutch 30 by supplying hydraulic oil into a cylinder chamber 50a in accordance with a rotation difference between the outer rotary member 10 and the inner rotary member 20; and a valve element 63 which opens/closes a flow passage 54c through which the oil returns from the cylinder chamber 50a to a reserve chamber 50b.

Description

  The present invention relates to a driving force transmission device.

  Japanese Patent Laid-Open No. 2008-232368 (Patent Document 1) describes a device that uses a piston driven by hydraulic pressure to engage a main clutch as a device that transmits driving force. This apparatus controls the transmission torque of the main clutch by supplying pressure oil to the piston by driving a hydraulic pump by a motor.

JP 2008-232368 A

However, since a motor is used to drive the hydraulic pump, the apparatus becomes complicated and the cost increases.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a driving force transmission device that can achieve cost reduction with a simpler configuration while using a hydraulic pump.

  (Claim 1) A driving force transmission device according to this means includes a cylindrical outer rotating member, an inner rotating member coaxially disposed in the outer rotating member so as to be relatively rotatable, the outer rotating member, and the Pressure oil is supplied to the cylinder chamber in accordance with the rotational difference between the main clutch that transmits torque to and from the inner rotating member, the piston that can press the main clutch, and the outer rotating member and the inner rotating member. A hydraulic pump that presses the piston toward the main clutch, and a valve body that opens and closes a flow path for returning oil from the cylinder chamber to the reserve chamber.

  (Claim 2) The driving force transmission device includes an electromagnetic actuator for driving the valve body, and the cylinder chamber includes an inner peripheral surface of the outer rotating member, an outer peripheral surface of the inner rotating member, and the hydraulic pump. And an area formed by one end face of the piston, and the reserve chamber includes an inner peripheral face of the outer rotating member, an outer peripheral face of the inner rotating member, the other end face of the hydraulic pump, and It may be a region formed by one end face of the electromagnetic actuator.

  (Claim 1) According to the present means, the rotation difference between the outer rotating member and the inner rotating member is used as a drive source of the hydraulic pump. This eliminates the need for a separate drive source such as a motor. Therefore, the configuration is simpler than in the prior art, and the cost can be reduced because no motor is used. Further, the sliding amount of the piston can be arbitrarily set. Therefore, the drag torque of the main clutch can be reliably reduced by setting the sliding amount of the piston large.

  (Claim 2) By forming the cylinder chamber and the reserve chamber in the region between the outer rotating member and the inner rotating member, the above configuration can be realized without supplying oil from the outside. Therefore, it is not necessary to separately provide a hydraulic pressure supply device or the like outside the outer rotating member, and the device can be downsized.

It is an axial sectional view of the driving force transmission device of this embodiment. It is radial direction sectional drawing of the hydraulic pump of FIG. It is radial direction sectional drawing of a hydraulic pump in case the outer member and inner member of a hydraulic pump are rotating without a rotation difference. It is radial direction sectional drawing of a hydraulic pump in case the outer member and inner member of a hydraulic pump have a rotation difference. FIG. 2 is an axial sectional view of the driving force transmission device in a state where pressure oil is supplied to a cylinder chamber with respect to FIG. 1. FIG. 6 is a cross-sectional view in the axial direction of the driving force transmission device with the pressure oil slightly returned from the cylinder chamber to the reserve chamber with respect to FIG. 5.

(Configuration of driving force transmission device)
The driving force transmission device 1 of the present embodiment will be described with reference to FIGS. For example, in a four-wheel drive vehicle, the drive force transmission device is applied to a drive force transmission system to the auxiliary drive wheel to which the drive force is transmitted according to the traveling state of the vehicle. More specifically, in a four-wheel drive vehicle, the driving force transmission device 1 includes, for example, a propeller shaft to which engine driving force is transmitted and a rear differential as an auxiliary driving wheel, or a rear differential and a drive shaft. It is connected between. In the following description, the former case will be described as an example. The driving force transmission device 1 transmits the driving force transmitted from the propeller shaft to the auxiliary driving wheel while changing the transmission ratio. The driving force transmission device 1 acts to reduce the rotation difference when, for example, a rotation difference between the front wheels and the rear wheels occurs.

  As shown in FIG. 1, the driving force transmission device 1 includes an outer case 10 as an outer rotating member, an inner shaft 20 as an inner rotating member, a main clutch 30, a piston 40, a hydraulic pump 50, and an electromagnetic valve. Device 60.

  The outer case 10 is supported on the inner peripheral side of a cylindrical hole cover (not shown) so as to be rotatable with respect to the hole cover. The outer case 10 is formed of, for example, an aluminum alloy of a nonmagnetic material mainly composed of aluminum, and is formed in a bottomed cylindrical shape. The outer peripheral surface of the cylindrical portion of the outer case 10 is rotatably supported on the inner peripheral surface of the hole cover via a bearing. Furthermore, the bottom part (the left side of FIG. 1) of the outer case 10 is connected to the vehicle rear end side of the propeller shaft (not shown). That is, it arrange | positions so that the bottomed cylindrical opening side of the outer case 10 may face the vehicle rear side. A female spline 11 a is formed at the axially central portion of the inner peripheral surface of the outer case 10.

  The inner shaft 20 is formed in an axial shape having a male spline 20a at the axially central portion of the outer peripheral surface. The inner shaft 20 is disposed in the outer case 10 so as to be relatively rotatable on the same axis and with its axial position regulated. Furthermore, the vehicle rear end side (the right side in FIG. 1) of the inner shaft 20 is connected to a differential gear (not shown).

  The main clutch 30 transmits torque between the outer case 10 and the inner shaft 20. The main clutch 30 is a wet multi-plate friction clutch formed of an iron-based material. The main clutch 30 is disposed between the inner peripheral surface of the cylindrical portion of the outer case 10 and the outer peripheral surface of the inner shaft 20. The main clutch 30 includes a plurality of inner main clutch plates 31 and a plurality of outer main clutch plates 32, which are alternately arranged in the axial direction. Each inner main clutch plate 31 has a female spline 31 a formed on the inner peripheral side, and is fitted to the male spline 20 a of the inner shaft 20. Each outer main clutch plate 32 has a male spline 32 a formed on the outer peripheral side, and is fitted to the female spline 11 a of the outer case 10.

  The piston 40 is formed in a hollow and thick disk shape. The piston 40 is disposed between the outer case 10 and the inner shaft 20 and adjacent to the vehicle rear end side of the main clutch 30. The piston 40 is provided so as to be relatively movable in the axial direction with respect to the outer case 10 and the inner shaft 20. It has been. The piston 40 moves to the left side in FIG. 1, thereby pressing the main clutch 30 to frictionally engage the inner main clutch plate 31 and the outer main clutch plate 32. Then, when the piston 40 is separated from the main clutch 30, the frictional engagement between the inner main clutch plate 31 and the outer main clutch plate 32 is released.

  The hydraulic pump 50 is disposed between the outer case 10 and the inner shaft 20 so as to form a cylinder chamber 50a on the vehicle rear side (one axial direction) of the piston 40. That is, a region surrounded by the axial end surface of the hydraulic pump 50, the outer case 10, the inner shaft 20, and the axial end surface of the piston 40 is the cylinder chamber 50a. The hydraulic pump 50 supplies pressure oil to the cylinder chamber 50a according to the rotation difference between the outer case 10 and the inner shaft 20, and presses the piston 40 toward the main clutch 30 side. At this time, the hydraulic pump 50 continuously supplies pressure oil to the cylinder chamber 50a by sucking oil from the reserve chamber 50b formed on the vehicle rear side (the other in the axial direction).

  The hydraulic pump 50 includes a pump outer member 51, a pump inner member 52, an outer fixing member 53, an inner fixing member 54, an outer oil seal 55, and an intermediate oil seal 56. The pump outer member 51 and the pump inner member 52 constitute a vane pump, as shown in FIG. That is, the inner peripheral surface of the pump outer member 51 is formed in an elliptical shape, for example, and the outer peripheral surface of the main body portion 52a of the pump inner member 52 is formed in a circular shape. The pump inner member 52 is provided with a plurality of vanes 52b that can protrude radially outward from the main body 52a. The tip of each vane 52b always presses the inner peripheral surface of the pump outer member 51. Therefore, the adjacent vane 52b partitions the pump outer member 51 and the main body 52a of the pump inner member 52 into a plurality of regions in the circumferential direction.

  The outer fixing member 53 fixes the main body 52 a of the pump inner member 52 to the outer case 10. The outer fixing member 53 is provided closer to the cylinder chamber 50a than the pump inner member 52, and a plurality of communication holes 53a are formed in the circumferential direction.

  The inner fixing member 54 fixes the pump outer member 51 to the inner shaft 20. In addition, a plurality of suction ports 54a are formed in the circumferential direction on the side of the reserve chamber 50b of the inner fixing member 54 to suck oil stored in the reserve chamber 50b into the pump chamber. As shown in FIG. 2, the suction port 54a is formed in the vicinity of an elliptical long axis. Further, on the cylinder chamber 50 a side of the inner fixing member 54, a discharge port 54 b is formed between the outer fixing member 53 and the radial direction. A plurality of discharge ports 54b are formed in the circumferential direction. The pressure oil discharged by the pump outer member 51 and the pump inner member 52 passes through the discharge port 54b of the inner fixing member 54 and is supplied to the cylinder chamber 50a.

  Further, the inner fixing member 54 is formed with a return flow path 54c for communicating the cylinder chamber 50a and the reserve chamber 50b and returning oil from the cylinder chamber 50a to the reserve chamber 50b. A plurality of return channels 54c are formed in the circumferential direction. A concave groove 54d is formed over the entire circumference of the inner fixing member 54 on the cylinder chamber 50a side in the return channel 54c. Further, the inner fixing member 54 is formed with a communication passage 54e that allows the cylinder chamber 50a and the reserve chamber 50b to communicate with each other and that allows a connecting column portion 63c of a second valve body 63 described later to be movably inserted. A plurality of communication paths 54e are formed in the circumferential direction.

  The outer oil seal 55 is attached to the inner peripheral surface of the outer case 10 and seals with the outer peripheral surface of the outer fixing member 53 opposed in the radial direction. The intermediate oil seal 56 is attached to the inner peripheral surface of the inner fixing member 54, and seals with the surface of the outer fixing member opposed in the radial direction.

  The electromagnetic valve device 60 includes an electromagnetic actuator 61, a first valve body 62, a second valve body 63, and a coil spring 64. The electromagnetic actuator 61 is fixed to a hole cover (not shown), and supports the outer case 10 and the inner shaft 20 so as to be relatively rotatable. A region surrounded by the axial end surface of the electromagnetic actuator 61, the outer case 10, the inner shaft 20, and the axial end surface of the hydraulic pump 50 is a reserve chamber 50b. The electromagnetic actuator 61 is formed by an electromagnetic coil, and generates an axial magnetic force by supplying a current.

  The first valve body 62 is formed in a cylindrical shape from a magnetic material, and is attracted to the electromagnetic actuator 61 side by supplying a current to the electromagnetic actuator 61. The second valve body 63 is integrally connected to the first valve body 62. Specifically, the second valve body 63 is sandwiched between the first valve body 62 and the disk portion 63a positioned in the reserve chamber 50b, and the cylinder chamber 50a, and the concave groove 54d of the inner fixing member 54 extends over the entire circumference. A circumferential claw portion 63b that can be closed, and a connecting column portion 63c that connects the disk portion 63a and the circumferential claw portion 63b in the axial direction and is inserted into the communication passage 54e.

  The coil spring 64 generates a biasing force with respect to the first valve body 62 in a direction in which the first valve body 62 moves away from the electromagnetic actuator 61. Accordingly, the axial positions of the first valve body 62 and the second valve body 63 are determined by the urging force of the coil spring 64 and the attractive force of the electromagnetic actuator 61. When the suction force by the electromagnetic actuator 61 is small, the return valve 54c is opened by the second valve body 63 being separated from the concave groove 54d, and the cylinder chamber 50a and the reserve chamber 50b are communicated. On the other hand, when the suction force by the electromagnetic actuator 61 is large, the second valve body 63 closes the concave groove 54d, thereby closing the return flow path 54c, and the cylinder chamber 50a and the reserve chamber 50b are not in communication with each other. Become. Further, by adjusting the supply current to the electromagnetic actuator 61, the opening area of the return flow path 54c can be adjusted, and the hydraulic pressure of the cylinder chamber 50a can be adjusted.

  Here, by forming the cylinder chamber 50a and the reserve chamber 50b in the region between the outer case 10 and the inner shaft 20, the above configuration can be realized without supplying oil from the outside. Accordingly, it is not necessary to separately provide a hydraulic pressure supply device or the like outside the outer case 10, and the device can be downsized.

(Hydraulic pump operation)
Next, the operation of the hydraulic pump will be described with reference to FIGS. When the outer case 10 and the inner shaft 20 rotate in the same direction at the same speed from the state shown in FIG. 2, there is no rotational difference between the outer case 10 and the inner shaft 20. In this case, it becomes as shown in FIG. That is, there is no rotational difference between the pump outer member 51 and the pump inner member 52. Therefore, the oil in the pump chamber between the pump outer member 51 and the pump inner member 52 does not fluctuate and is not discharged from the pump chamber to the cylinder chamber 50a.

  On the other hand, when a rotation difference occurs between the outer case 10 and the inner shaft 20, for example, as shown in FIG. FIG. 4 shows a case where the pump inner member 52 fixed to the outer case 10 rotates and the pump outer member 51 fixed to the inner shaft 20 is stopped. By this operation, the oil in the reserve chamber 50b is sucked into the pump chamber through the suction port 54a and compressed in the pump chamber, and then the pressure oil is supplied from the discharge port 54b to the cylinder chamber 50a. As described above, when a rotational difference occurs between the outer case 10 and the inner shaft 20, the pressure oil is supplied to the cylinder chamber 50a.

(Operation of driving force transmission device)
Subsequently, the operation of the driving force transmission device 1 will be described mainly with reference to FIGS. 1 and 5 to 6. It is assumed that there is a rotational difference between the outer case 10 and the inner shaft 20 from the state shown in FIG. Then, the operation of the hydraulic pump 50 is as shown in FIG. That is, the oil in the reserve chamber 50b is sucked into the pump chamber through the suction port 54a and compressed in the pump chamber, and then the pressure oil is supplied from the discharge port 54b to the cylinder chamber 50a.

  At this time, as shown in FIG. 5, current is supplied to the electromagnetic actuator 61, and the first valve body 62 is attracted to the electromagnetic actuator 61 side. Then, the circumferential claw portion 63b of the second valve body 63 closes the concave groove 54d of the inner fixing member 54 over the entire circumference. Accordingly, the return flow path 54c is closed, and oil from the cylinder chamber 50a to the reserve chamber 50b cannot return.

  Therefore, the pressure of the oil in the cylinder chamber 50a increases, and the piston 40 presses the main clutch 30. As a result, the inner main clutch plate 31 and the outer main clutch plate 32 constituting the main clutch 30 are frictionally engaged, and torque is transmitted between the outer case 10 and the inner shaft 20. Therefore, the rotation difference between the outer case 10 and the inner shaft 20 becomes smaller. Thus, since the hydraulic pump 50 is driven using the rotational difference between the outer case 10 and the inner shaft 20, it is not necessary to separately provide a drive source such as a motor. Therefore, the configuration becomes very simple, and the cost can be reduced because no motor is used.

  Subsequently, in order to release the engagement of the main clutch 30, it is necessary to reduce the oil pressure in the cylinder chamber 50a. In this case, the current supplied to the electromagnetic actuator 61 is reduced as shown in FIG. Then, the first valve body 62 moves away from the electromagnetic actuator 61 by the urging force of the coil spring 64. As a result, the circumferential claw portion 63b of the second valve body 63 is separated from the concave groove 54d of the inner fixing member 54, and the return channel 54c is opened. Since the oil pressure in the cylinder chamber 50a is higher than the oil pressure in the reserve chamber 50b, the oil flows from the cylinder chamber 50a to the reserve chamber 50b. In this way, the engagement of the main clutch 30 is released by reducing the oil pressure in the cylinder chamber 50a.

  Here, the sliding amount (movement amount) of the piston 40 can be arbitrarily set. Therefore, by setting the sliding amount of the piston 40 to be large, the inner main clutch plate 31 and the outer main clutch plate 32 are sufficiently separated in a disengaged state. Therefore, the drag torque of the main clutch 30 can be reliably reduced.

  Further, the axial position of the second valve body 63 can be controlled by controlling the current supplied to the electromagnetic actuator 61. As a result, the opening area of the circumferential claw 63b of the second valve body 63 and the return channel 54c is controlled. By controlling the opening area, the pressure of the oil in the cylinder chamber 50a can be controlled. That is, when a rotational difference between the outer case 10 and the inner shaft 20 occurs, the transmission torque of the main clutch 30 can be controlled by controlling the supply current to the electromagnetic actuator 61.

1: driving force transmission device, 10: outer case (outer rotating member), 20: inner shaft (inner rotating member), 30: main clutch, 40: piston, 50: hydraulic pump, 50a: cylinder chamber, 50b: reserve chamber 54a: suction port, 54b: discharge port, 54c: return flow path, 61: electromagnetic actuator, 62: first valve body, 63: second valve body, 63b: circumferential claw portion

Claims (2)

A cylindrical outer rotating member;
An inner rotating member disposed coaxially within the outer rotating member so as to be relatively rotatable;
A main clutch that transmits torque between the outer rotating member and the inner rotating member;
A piston capable of pressing the main clutch;
A hydraulic pump that supplies pressure oil to a cylinder chamber and presses the piston toward the main clutch according to a rotational difference between the outer rotating member and the inner rotating member;
A valve body for opening and closing a flow path for returning oil from the cylinder chamber to the reserve chamber;
A driving force transmission device comprising: The driving force transmission device includes an electromagnetic actuator that drives the valve body,
The cylinder chamber is a region formed by an inner peripheral surface of the outer rotating member, an outer peripheral surface of the inner rotating member, one end surface of the hydraulic pump, and one end surface of the piston,
2. The drive according to claim 1, wherein the reserve chamber is a region formed by an inner peripheral surface of the outer rotating member, an outer peripheral surface of the inner rotating member, the other end surface of the hydraulic pump, and one end surface of the electromagnetic actuator. Power transmission device.

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