JP2011256933A - Friction transmission structure, friction clutch, and differential lock device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a relative rotation speed between friction surfaces to be smaller than a relative rotation speed between two members to be frictionally engaged.SOLUTION: A rotatable floating plate 109 is provided between friction surfaces provided to an outer plate 111 and an inner plate 113 that are relatively rotatable. Theoretically, the relative rotation speed between the floating plate 109 and the friction surfaces of the outer and inner plates 111, 113 may be caused to be 1/2 the relative rotation speed between the outer and inner plates 111, 113. Accordingly, the relative rotation speed between the friction surfaces may be caused to be lower than the relative rotation speed between the outer and inner plates 111, 113.

Description

The present invention relates to a friction transmission structure, a friction clutch, and a differential lock device.

  Conventionally, there is a friction clutch described in Patent Document 1. This friction clutch controls the fastening of a multi-plate main clutch that is engaged between a pair of rotating members including a case on the outer peripheral side and a shaft on the inner peripheral side.

  In this friction clutch, when the electromagnet is excited, the armature is attracted and the pilot clutch is engaged and adjusted. The cam mechanism works by this pilot clutch engagement adjustment and is converted into a thrust force, and a predetermined engagement force is applied to the main clutch.

  However, there has been a problem that the relative rotational speed between the friction surfaces of the pilot clutch cannot be made lower than the relative rotational speed between the outer plate and the inner plate that are frictionally engaged with each other.

  For this reason, the viscosity resistance due to the lubricating oil of the pilot clutch cannot be lowered at low temperatures when the viscosity of the lubricating oil is high, and a large drag torque is generated. Needed a drop.

  In addition, at the time of high speed rotation, the relative rotational speed between the friction surfaces of the pilot clutch is high, and there is a possibility that the pilot clutch may operate due to viscous resistance, so there is a limit to the use of high speed rotation.

  Furthermore, there is a problem that the relative rotational speed between the friction surfaces is high and it is disadvantageous to wear. Such a problem is not limited to the above-described structure, and is similar between brake friction surfaces.

JP 2005-76699 A

  The problem to be solved is that the relative rotational speed between the friction surfaces cannot be made lower than the relative rotational speed between the two members frictionally engaged.

  The present invention makes it possible to make the relative rotational speed between the friction surfaces lower than the relative rotational speed between the two members that are frictionally engaged. A friction transmission structure for performing frictional engagement, characterized in that a rotatable floating plate is interposed between the friction surfaces.

  The present invention is a friction transmission structure that allows frictional engagement of friction surfaces provided in a pair of relatively rotatable members, and a rotatable floating plate is interposed between the friction surfaces.

  Therefore, theoretically, the relative rotational speed between the friction surface and the floating plate can be lower than the relative rotational speed of the pair of members, and the relative rotational speed between the friction surfaces can be reduced between the pair of members. It can be made lower than the relative rotational speed.

It is sectional drawing of a deceleration drive device. Example 1 It is a principal part expanded sectional view. Example 1 Of the deceleration drive. (Example 2) FIG. 4 is a cross-sectional view illustrating a differential lock device, in which an upper half portion shows a differential lock release state and a lower half portion shows a differential lock state. (Example 3)

  The purpose of enabling the relative rotational speed between the friction surfaces to be lower than the relative rotational speed between the two frictionally engaging members has been realized with a floating plate.

  FIG. 1 is a cross-sectional view of a reduction driving device to which a friction transmission structure according to a first embodiment of the present invention is applied.

  As shown in FIG. 1, the speed reduction drive device 1 includes an electric motor or a motor generator 3 as a drive source, and is provided with a carrier case 5 that is supported on the vehicle body side and fixed on a fixed side, and is a first-stage reduction gear set. , Second reduction mechanisms 7 and 9, a friction clutch 11, and a rear differential device 13.

  The feature of the embodiment of the present invention is that the friction clutch 11 is provided with a floating plate, which will be described later.

  The carrier case 5 supports the motor generator 3, the first and second speed reduction mechanisms 7 and 9, the friction clutch 11, and the rear differential device 13, and includes a case main body 15 and a case cover 17. It has a combined structure. The case main body portion 15 and the case cover portion 17 are fastened and connected by bolts 19.

  On the input part side of the carrier case 5, a through body 20 is provided in the case body 15, and a mounting flange 21 is provided on the outer periphery of the through body 20. The motor / generator 3 is mounted on the mounting flange 21 and fastened and fixed by bolts. A seal member 23 is attached to the penetrating portion 20.

  Boss portions 27 and 29 are provided on the left and right of the output side of the carrier case 5. Seal members 31 and 33 are attached to the boss portions 27 and 29.

  The first and second speed reduction mechanisms 7 and 9 decelerate and output the driving force of the motor / generator 3, and the first speed reduction mechanism 7 constitutes a front stage of a plurality of speed reduction gear sets, and is a carrier. -It is supported by the input part side of case 5.

  The first reduction mechanism 7 includes a first small diameter gear 35 and a first large diameter gear 37.

  The first small diameter gear 35 is provided integrally with the input shaft 39. The input shaft 39 is rotatably supported by the carrier case 5 by bearings 41 and 43. The output shaft of the motor / generator 3 is coupled to one end of the input shaft 39, and the seal member 23 is in contact with the outer periphery of the end of the input shaft 39.

  The first large-diameter gear 37 is press-fitted and supported by the intermediate shaft 45. One end of the intermediate shaft 45 is supported on the case cover 17 by a ball bearing 47, and the other end is supported on the case main body 5 by a needle bearing 49. An oil seal 51 is disposed between one end side of the intermediate shaft 45 and the case cover portion 17 to prevent oil leakage to the outside. An end portion of the intermediate shaft 45 projects out of the case / cover portion 17 and a rotation detecting gear 53 is attached.

  The second speed reduction mechanism 9 is composed of a second small diameter gear 55 and a second large diameter gear 57 that are meshed with each other. The second small diameter gear 55 is integrally formed with the intermediate shaft 45, and the second large diameter gear 57 is welded to the end of the outer differential case 59 of the rear differential 31.

  The output torque of the motor / generator 3 is decelerated by the first and second deceleration mechanisms 7 and 9 to the traveling rotational speed range of the rear wheels, and the torque is amplified to rotate the outer differential case 59 of the rear differential 13. It is like that.

  The friction clutch 11 includes an outer differential case 59, an inner differential case 61, a multi-plate main clutch 63, a ball cam 65 as a fastening mechanism, a pressure plate 67, a cam ring 69, and a multi-plate pilot. A clutch 71, a return spring 73, an armature 75, and an electromagnet 77 are included.

  The second large-diameter gear 57 of the outer differential case 59 is supported on the inner differential case 61 by ball bearings 79 and 81. The outer differential case 59 has a floating structure in which only the torque transmission by the second large-diameter gear 57 is performed and the member supporting function is released.

  In the inner differential case 61, a boss portion 83 at one end is supported by the case cover portion 17 by a ball bearing 85, and a boss portion 87 at the other end is supported by a ball bearing 89 and a core 91 of an electromagnet 77. It is supported by the main body 5. The core 91 is fixed to the case body 5.

  A rotor 93 formed of a magnetic material is disposed on the outer periphery of the boss portion 87 and is positioned in the axial direction by a snap ring 95. The rotor 93 is formed with a nonmagnetic portion 93a.

  The main clutch 63 is disposed between the outer differential case 59 and the inner differential case 61. The outer plate of the main clutch 63 is spline engaged with the inner periphery of the outer differential case 59, and the inner plate is spline engaged with the outer periphery of the inner differential case 61.

  The pilot clutch 71 is disposed between the outer differential case 59 and the cam ring 69 as the friction transmission structure of this embodiment. An outer plate (described later) of the pilot clutch 71 is spline-engaged with the inner periphery of the outer differential case 59, and the inner plate is spline-engaged with the outer periphery of the cam ring 69. In the outer plate and the inner plate, a circumferential long hole that forms a nonmagnetic portion is formed in the radially intermediate portion.

  The ball cam 65 is formed between a pressure plate 67 as a pressing member and a cam ring 69. The pressure plate 67 is splined to the outer periphery of the inner differential case 61 so as to be axially movable, and receives the cam thrust force of the ball cam 65 to press the main clutch 63.

  A thrust bearing 97 is disposed between the cam ring 69 and the rotor 93. The thrust bearing 97 receives the cam reaction force of the ball cam 65 and allows relative rotation between the cam ring 69 and the rotor 93.

  A return spring 73 is disposed between the pressure plate 67 and the inner differential case 61. The pressure plate 67 is urged in the direction of releasing the connection of the main clutch 63 by a return spring 73.

  The armature 75 is formed in a ring shape and is disposed between the pressure plate 67 and the pilot clutch 71 so as to be axially movable.

  The lead wire of the electromagnet 77 is drawn out of the case body 5 via a grommet and connected to the battery 37 side by a connector.

  An appropriate air gap is formed between the core 91 of the electromagnet 77 and the rotor 93. The air gap, the rotor 93, the pilot clutch 71, and the armature 75 constitute a magnetic path of the electromagnet 77. When the electromagnet 77 is energized and controlled, a magnetic flux loop is formed on the magnetic path.

  The differential mechanism of the rear differential 13 includes a pinion shaft 101, a pinion gear 103, and output side gears 105 and 107.

The side gears 105 and 107 are splined to the left and right axle shafts, respectively.
[Torque transmission]
The output of the motor generator 3 is transmitted from the input shaft 39 to the outer differential case 59 via the first and second reduction mechanisms 7 and 9. The outer differential case 59 is transmitted to the inner differential case 61 via the friction clutch 11.

  The rotation of the inner differential case 61 is distributed from the pinion shaft 101 to the side gears 105 and 107 via the pinion gear 103, and further transmitted from the axle shaft to the left and right rear wheels.

  When a driving resistance difference occurs between the rear wheels on a rough road or the like, the driving force of the motor generator 3 is differentially distributed to the left and right rear wheels by the rotation of the pinion gear 103.

  The engagement control of the friction clutch 11 is performed by energization control of the electromagnet 77 as follows, for example.

  The controller performs energization control of the electromagnet 77 according to the road surface state detected by various sensors, traveling conditions such as start, acceleration, and turning of the vehicle, and steering conditions.

  The energization control of the electromagnet 77 is performed together with the operation control of the motor / generator 3, and the energization stop of the electromagnet 77 is performed when the motor / generator 3 is stopped.

  When the electromagnet 77 is excited, the armature 75 is attracted by the magnetic flux loop, and the pilot clutch 71 is engaged with the rotor 93 to generate pilot torque. When the pilot torque is generated, a motor is applied to the ball cam 65 via the cam ring 69 connected to the outer differential case 59 by the pilot clutch 71 and the pressure plate 67 on the inner differential case 61 side. -The transmission torque from the generator 3 side acts. The ball cam 65 converts the transmission torque into a cam thrust force while amplifying the transmission torque, and moves the pressure plate 67 to fasten the main clutch 63.

  When the friction clutch 11 is thus connected, the torque of the motor generator 3 transmitted to the second large-diameter gear 57 is transmitted from the outer differential case 59 to the inner differential case 61, and its rotation is differential. It is distributed to the left and right rear wheels by the mechanism, and the vehicle enters a four-wheel drive state.

  At this time, when the excitation current of the electromagnet 77 is controlled, the slip rate of the pilot clutch 71 changes, the cam thrust force of the ball cam 65 changes, and the transmission torque to the rear wheel side is controlled. When such transmission torque control is performed during turning, for example, the turning performance and the stability of the vehicle body can be greatly improved.

  When the excitation of the electromagnet 77 is stopped, the pilot clutch 71 is released, the cam thrust force of the ball cam 65 disappears, the pressure plate 67 is returned by the urging force of the return spring 73, and the main clutch 63 is released. Thus, the coupling of the friction clutch 11 is released, and the vehicle enters a two-wheel drive state with front wheel drive.

  Since the release operation of the friction clutch 11 is performed simultaneously with the stop operation of the motor generator 3 as described above, in the two-wheel drive state, the outer differential case 59, the speed reduction mechanisms 7 and 9, the motor generator 3 Is separated from the rotation of the rear wheel and is prevented from being mechanically rotated.

Accordingly, the speed reduction mechanisms 7 and 9, the motor / generator 3, and the circuit elements of the integrated circuit such as the bearings, the battery, and the regulator are protected from the adverse effects caused by the accompanying rotation of the rear wheels, and the durability is improved.
[Floating plate]
FIG. 2 is an enlarged cross-sectional view of a main part.

  As shown in FIG. 2, one rotatable floating plate 109 is interposed between the friction surfaces of the pilot clutch 71, which is a friction clutch. The friction surface is formed on an outer plate 111 and an inner plate 113 which are a pair of members that can rotate freely.

  The floating plate 109 is made of a magnetic material such as steel, and is not engaged with any of the outer differential case 59 and the inner differential case 61. In the floating plate 109, a long hole in the circumferential direction that forms a nonmagnetic portion is formed in the intermediate portion in the radial direction.

When the outer plate 111 and the inner plate 113 rotate relative to each other, the outer plate 111 and the inner plate 113 rotate relative to the floating plate 109. Theoretically, the outer plate 111, the inner plate 113, and the floating plate 109 Relative rotational speed between the outer plate 111 and the inner plate 113 can be halved.
[Effect of Example]
In the embodiment of the present invention, a rotatable floating plate 109 is interposed between the friction surfaces provided on the outer plate 111 and the inner plate 113 that can be relatively rotated.

  Theoretically, the relative rotational speed between the friction surfaces of the outer plate 111 and the inner plate 113 and the floating plate 109 is ½ of the relative rotational speed of the outer plate 111 and the inner plate 113 (a plurality of sheets). It is possible to reduce the relative rotational speed between the friction surfaces to be lower than the relative rotational speed between the outer plate 111 and the inner plate 113 by interposing the floating plate 109. it can.

  For this reason, it is not necessary to use a normal viscosity oil instead of a low-viscosity oil as the lubricating oil, or to reduce the oil level height. That is, since the relative rotational speed between the friction surfaces can be lowered, the viscosity resistance due to the lubricating oil of the pilot clutch 71 can be lowered even at low temperatures when the viscosity of the lubricating oil is high, and the generation of drag torque can be suppressed. it can.

  Since it can be made difficult to be affected by the oil level, layout requirements can be relaxed.

  In addition, the relative rotational speed between the friction surfaces of the pilot clutch 71 can be made lower than in the past even during high speed rotation, and the possibility of the pilot clutch 71 being operated by viscous resistance is suppressed, and the limit of high speed rotation that can be used Can be increased.

  Furthermore, the relative rotational speed between the friction surfaces can be substantially reduced, which is advantageous for wear.

  FIG. 3 is a cross-sectional view of a reduction driving device according to the second embodiment of the present invention. The basic configuration is the same as that of the first embodiment, and the same or corresponding components are denoted by the same reference numerals, or the same reference numerals are denoted by A, and redundant description is omitted.

  The deceleration drive device 1A of the present embodiment is such that the friction clutch 11A is hydraulically driven.

  A cylinder portion 115 is formed in the case main body portion 15A, and a piston 117 is disposed. An oil passage 119 communicating with the cylinder portion 115 is formed in the case main body portion 15A.

  The pilot clutch 71 is received by a pressure receiving plate 121 engaged with the outer differential case 59 in the rotational direction and the axial direction.

  The cam ring 69 is received in the axial direction by a support plate 123 via a thrust bearing 97, and a return spring 125 is interposed between the support plate 123 and the piston 117.

  Also in this embodiment, a rotatable floating plate 109 is interposed between the friction surfaces provided on the outer plate 111 and the inner plate 113 of the pilot clutch 71, respectively.

  Then, by supplying hydraulic pressure from the oil passage 119 into the cylinder portion 115, the piston 117 moves to the pilot clutch 71 side, and the pilot clutch 71 is fastened to the pressure receiving plate 121.

  When the supply of hydraulic pressure is lost, the piston 117 returns to the original position by the urging force of the return spring 125.

  Therefore, also in this embodiment, the relative rotational speed between the friction surfaces of the outer plate 111 and the inner plate 113 and the floating plate 109 is theoretically 1 of the relative rotational speed of the outer plate 111 and the inner plate 113. / 2 and the same effects as those of the first embodiment can be obtained.

  FIG. 4 is a cross-sectional view illustrating a differential lock device according to a third embodiment of the present invention, in which the upper half portion is in a differential lock release state and the lower half portion is in a differential lock state. The basic configuration is the same as that of the first embodiment, and the same or corresponding components are denoted by the same reference numerals, or the same reference numerals are denoted by B, and redundant description is omitted.

  The friction transmission structure of the present embodiment is applied as a differential lock device of the differential device 13B, and causes frictional engagement between the friction surfaces provided in the electromagnet 125 and the armature 127, which are a pair of relatively rotatable members, respectively. Is.

  In this embodiment, a single floating plate 109B is provided between the electromagnet 125 and the armature 127.

  The electromagnet 125 is supported on the fixed side, and the inner peripheral surface thereof is received by the outer peripheral surface of the receiving member 129 supported by the outer periphery of the boss portion of the differential case 61B via the bush 131. The armature 127 is engaged with the cam ring 69B of the ball cam 65B.

  One end of the lock pin 133 is arranged opposite to the inner peripheral side of the pressure plate 67B, and the other end of the lock pin 133 is configured to be engaged with and disengaged from the recess 105Ba of the side gear 105B.

  A circumferential groove 135 is formed at one end of the lock pin 133 and the inner peripheral side of the spring receiving plate 137 is engaged.

  On the outer peripheral side of the pressure plate 67B, the end of the return spring 139 is opposed to the spring receiving plate 137, and a plurality of the return springs 139 are arranged in the circumferential direction and accommodated in the hole 61Ba of the differential case 61B. ing.

  The ball cam 65B, the pressure plate 67B, the cam ring 69B, the electromagnet 125, and the armature 127 constitute a fastening mechanism in this embodiment.

  When the electromagnet 125 is energized, the armature 127 is attracted and frictionally engaged.

  Due to this frictional engagement, the cam ring 69B is subjected to rotation restriction, and the pressure plate 67B receives a thrust force toward the lock pin 133 with respect to the receiving member 129 by the action of the ball cam 65B.

  With this thrust force, the lock pin 133 moves against the urging force of the return spring 139 and engages with the recess 105Ba of the side gear 105B.

  By this engagement, the side gear 105B cannot rotate relative to the differential case 61B, and the differential lock state is established.

  When the energization of the electromagnet 125 is released, the armature 127 is attracted to the electromagnet 125, and the spring receiving plate 137 and the pressure plate 67B are pushed back by the urging force of the return spring 139.

  When the spring receiving plate 137 is pushed back, the lock pin 133 is not engaged with the recess 105Ba, and the differential lock is released.

  When the energization of the electromagnet 125 is released, the electromagnet 125 and the armature 127 rotate relative to each other. The relative rotational speed at this time can theoretically be halved by the floating plate 109B as in the first embodiment.

Therefore, this embodiment can achieve the same effects as those of the first embodiment.
[Others]
The friction transmission structure can be configured as a brake. Further, a plurality of floating plates 109 can be provided in an overlapping manner in the inner and outer plates of the friction clutch, and the relative rotational speed of the friction clutch in this case can be further reduced.

59 Outer differential case (outside rotating member)
61 Inner differential case (inner rotating member)
63 Main clutch 65, 65B Ball cam 67, 67B Pressure plate (pressing member, fastening mechanism)
69,69B Cam ring (fastening mechanism)
71 Pilot clutch (friction transmission structure, fastening mechanism)
75,127 Armature (fastening mechanism)
77,125 Electromagnet (fastening mechanism)
109, 109B Floating plate 111 Outer plate (member that can rotate relative)
113 Inner plate (member capable of relative rotation)

Claims (4)

A friction transmission structure that causes frictional engagement of friction surfaces provided in a pair of relatively rotatable members,
A rotatable floating plate is interposed between the friction surfaces.
Friction transmission structure characterized by that. The friction transmission structure according to claim 1,
The friction surface is provided in a friction clutch interposed between the pair of relatively rotatable members.
Friction transmission structure characterized by that. A multi-plate main clutch interposed between inner and outer rotating members capable of relative rotation;
A pressing member that presses the main clutch to control torque transmission between the inner and outer rotating members;
A friction clutch comprising a fastening mechanism interposed between the pressing member and one of the inner and outer rotating members and configured to press the pressing member due to frictional engagement of a friction surface by fastening of a pilot clutch; ,
A rotatable floating plate is interposed between the friction surfaces of the pilot clutch.
A friction clutch characterized by that. A locking member that is interposed between rotating members that can rotate relative to each other;
A pressing member that presses the locking member to lock the relative rotation between the rotating members;
A differential lock device comprising a fastening mechanism interposed between the pressing member and a fixed side and configured to press the pressing member due to frictional engagement of a friction surface by fastening;
A rotatable floating plate is interposed between the friction surfaces.
A differential lock device characterized by that.

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