JP2019163813A - Power transmission device - Google Patents

Abstract

To detect excessive wear of a clutch part.SOLUTION: A power transmission device 100 includes a housing 20, a clutch part 6, and a position sensor 8. Torque from a driving source is transmitted to the housing 20 and the housing 20 is rotatably disposed. The clutch part 6 has a friction surface which frictionally engages with a side wall part of the housing 20. Further, the clutch part 6 is disposed in the housing 20 so as to be movable in an axial direction. The position sensor 8 detects a position of the clutch part 6 in the axial direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power transmission device.

  The power transmission device includes a casing that rotates with torque from a drive source, and a lockup clutch that can rotate relative to the casing in the casing. For example, the torque converter has a front cover, an impeller, a turbine, and a lockup device. The front cover and the impeller shell constitute a casing.

  The lockup device has a clutch portion that frictionally engages with the front cover. When the clutch portion frictionally engages with the front cover, torque from the front cover can be output without using hydraulic oil.

JP 2011-220374 A

  When the friction material is worn in the clutch portion of the lock-up device as described above, there is a possibility that problems such as wear powder generated by the wear being clogged in the drain or abnormal vibrations may occur. Then, the subject of this invention is providing the power transmission device which can detect the excessive wear of a clutch part.

  A power transmission device according to an aspect of the present invention is configured to transmit torque from a driving source to driving wheels. The power transmission device includes a housing, a clutch unit, and a position sensor. The casing is arranged to be able to rotate by receiving torque from the drive source. The clutch portion has a friction surface facing the first direction. The clutch portion is disposed so as to be movable in the first direction within the housing, and can be engaged with the housing. The position sensor detects the position of the clutch portion in the first direction.

  According to this configuration, excessive wear of the friction surface of the clutch portion can be detected based on the position of the clutch portion detected by the position sensor. Therefore, excessive wear of the clutch portion can be suppressed by replacing the wear surface before the clutch portion is excessively worn.

  Preferably, the first direction is along the rotation axis of the housing.

  Preferably, the position sensor is attached to a side wall portion of the housing facing the friction surface, and detects a distance from the clutch portion.

  Preferably, the position sensor is attached to the outer peripheral wall portion of the housing that is radially outward from the friction surface, and detects the presence or absence of the clutch portion.

  Preferably, a control unit that acquires position information of the clutch unit detected by the position sensor is further provided.

  Preferably, when the control unit determines that the position of the clutch unit is closer to the side wall portion of the housing than the threshold value based on the position information, the control unit displays a warning.

  Preferably, when the control unit determines that the position of the clutch unit is closer to the side wall portion of the housing than the threshold based on the position information, the clutch portion is configured to release the frictional engagement between the friction surface and the side wall portion of the housing. Move.

  According to the present invention, excessive wear of the clutch portion can be detected.

Sectional drawing of a power transmission device. The flowchart which shows operation | movement of a control part. Sectional drawing of the power transmission device which concerns on a modification. Sectional drawing of the power transmission device which concerns on a modification.

Hereinafter, embodiments of a power transmission device according to the present invention will be described with reference to the drawings.
[overall structure]
FIG. 1 is a cross-sectional view of a power transmission device 99 according to an embodiment of the present invention. The power transmission device 99 includes a torque converter 100. In the following description, “axial direction” means a direction in which the rotation axis O of the torque converter 100 extends. Further, “circumferential direction” means a circumferential direction of a circle around the rotation axis O, and “radial direction” means a radial direction of the circle around the rotation axis O. The inner side in the radial direction means the side approaching the rotation axis O in the radial direction, and the outer side in the radial direction means the side away from the rotation axis O in the radial direction. Although not shown, an engine is arranged on the left side of FIG. 1, and a transmission is arranged on the right side of FIG. The axial direction in the present embodiment corresponds to the first direction of the present invention.

  Torque converter 100 is configured to transmit torque from an engine as a drive source to drive wheels. The torque converter 100 can rotate around the rotation axis O. The torque converter 100 includes a front cover 2, an impeller 3, a turbine 4, a stator 5, a lockup device 10, and a dynamic vibration absorber 15. The power transmission device 99 includes a torque converter 100, a position sensor 8, a power reception unit 11, a power transmission unit 12, and a control unit 13.

[Front cover 2]
Torque from the engine (an example of a drive source) is input to the front cover 2. The front cover 2 has a disc portion 21 and a first cylindrical portion 22. The first cylindrical portion 22 extends in the axial direction from the outer peripheral end of the disc portion 21 to the impeller 3 side.

[Impeller 3]
The impeller 3 includes an impeller shell 31, a plurality of impeller blades 32, and an impeller hub 33. An outer peripheral end portion of the impeller shell 31 is fixed to a distal end portion of the first cylindrical portion 22 of the front cover 2. For example, the impeller shell 31 is fixed to the front cover 2 by welding.

  The impeller blade 32 is fixed to the inner surface of the impeller shell 31. The impeller hub 33 is fixed to the inner peripheral portion of the impeller shell 31 by welding or the like.

  The impeller shell 31 and the front cover 2 constitute a casing 20 of the torque converter 100. The housing 20 is filled with fluid. Specifically, the casing 20 is filled with hydraulic oil. The casing 20 is arranged to be able to rotate by receiving torque from the engine.

[Turbine 4]
The turbine 4 is disposed to face the impeller 3. The turbine 4 includes a turbine shell 41, a plurality of turbine blades 42, and a turbine hub 43. The turbine blade 42 is fixed to the inner surface of the turbine shell 41 by brazing or the like.

  The turbine shell 41 is fixed to the turbine hub 43 by rivets 101. A spline hole 433 is formed in the inner peripheral surface of the turbine hub 43. The transmission input shaft is spline-fitted into the spline hole 433.

[Stator 5]
The stator 5 is configured to rectify the hydraulic oil that returns from the turbine 4 to the impeller 3. The stator 5 is rotatable around the rotation axis O. The stator 5 includes a stator carrier 51 and a plurality of stator blades 52.

[Lock-up device 10]
The lockup device 10 is configured to mechanically transmit torque from the front cover 2 to the turbine hub 43. The lockup device 10 is disposed between the front cover 2 and the turbine 4 in the axial direction. Further, the lockup device 10 is disposed in the housing 20. The lockup device 10 includes a clutch unit 6 and a damper mechanism 7.

  The clutch unit 6 includes a piston 61 and a friction material 62. The piston 61 has a disk shape. The piston 61 has a through hole at the center. The turbine hub 43 extends in the through hole of the piston 61. The space between the outer peripheral surface of the turbine hub 43 and the inner peripheral surface of the piston 61 is sealed.

  The piston 61 is disposed so as to be rotatable relative to the housing 20. The piston 61 is disposed so as to be rotatable relative to the turbine hub 43. The piston 61 is disposed so as to be movable in the axial direction. Specifically, the piston 61 can slide on the turbine hub 43 in the axial direction.

  The piston 61 has a piston main body 611 and a second cylindrical portion 612. The piston main body 611 has a disc shape and faces the disc portion 21 of the front cover 2. The second cylindrical portion 612 extends in the axial direction from the outer peripheral end of the piston main body 611. Specifically, the second cylindrical portion 612 extends in a direction away from the front cover 2 from the outer peripheral end portion of the piston main body portion 611. The outer peripheral surface of the second cylindrical portion 612 is opposed to the inner peripheral surface of the first cylindrical portion 22 of the front cover 2.

  The friction material 62 is annular. The friction material 62 is fixed to the piston 61. Specifically, the friction material 62 is fixed to the outer peripheral end portion of the piston 61. The friction material 62 is disposed so as to face the disc portion 21 of the front cover 2. The friction material 62 and the disc portion 21 of the front cover 2 face each other in the axial direction. The surface of the friction material 62 facing the disc portion 21 corresponds to the friction surface of the present invention.

  The clutch portion 6 is movable in the axial direction between the friction engagement position and the release position. The clutch portion 6 frictionally engages with the housing 20 when in the friction engagement position. Specifically, when the clutch portion 6 moves in the axial direction to the front cover 2 side (left side in FIG. 1), the friction material 62 of the clutch portion 6 comes into contact with the disk portion 21 of the front cover 2. Friction engagement. As a result, the clutch portion 6 enters a friction engagement state and rotates integrally with the front cover 2. In this friction engagement state, the torque input to the front cover 2 is output from the turbine hub 43 via the lockup device 10.

  The clutch unit 6 releases the frictional engagement between the friction material 62 and the housing 20 when in the release position. Specifically, when the clutch portion 6 moves to the side away from the front cover 2 in the axial direction (the right side in FIG. 1), the friction material 62 of the clutch portion 6 is separated from the disc portion 21 of the front cover 2 and the friction is caused. The material 62 is not in contact with the disc portion 21. As a result, the clutch portion 6 is in a released state in which the frictional engagement between the friction material 62 and the disc portion 21 is released, and can be rotated relative to the front cover 2. In this released state, the torque input to the front cover 2 is output from the turbine hub 43 via the impeller 3 and the turbine 4.

  Moreover, the clutch part 6 can take a slip state. In this slip state, in the clutch portion 6, the friction material 62 and the disc portion 21 are in contact with each other, but are frictionally engaged with a weaker force than in the friction engagement state. For this reason, the friction material 62 and the disc part 21 are frictionally engaged while slipping. In this slip state, part of the torque input to the front cover 2 is output from the turbine hub 43 via the impeller 3 and the turbine 4, and the other is output from the turbine hub 43 via the lockup device 10.

  The damper mechanism 7 is disposed between the piston 61 and the turbine 4 in the axial direction. The damper mechanism 7 includes a drive plate 71, a driven plate 72, and a plurality of torsion springs 73.

  The drive plate 71 is formed in a disc shape, and its outer peripheral end is engaged with the piston 61. For this reason, the drive plate 71 rotates integrally with the piston 61. Further, the drive plate 71 and the piston 61 move relative to each other in the axial direction. The drive plate 71 has a plurality of accommodating portions 711 that are arranged at intervals in the circumferential direction.

  The driven plate 72 is formed in a disc shape. The driven plate 72 is fixed to the turbine hub 43. Specifically, the inner peripheral end of the driven plate 72 is fixed to the turbine hub 43 by welding or the like. The driven plate 72 has a plurality of accommodating portions 721 that are arranged at intervals in the circumferential direction. The housing portion 721 of the driven plate 72 is disposed so as to overlap the housing portion 711 of the drive plate 71 when viewed in the axial direction.

  The torsion spring 73 is accommodated in the accommodating portion 711 of the drive plate 71 and the accommodating portion 721 of the driven plate 72. The torsion spring 73 elastically connects the drive plate 71 and the driven plate 72.

  With the above configuration, the torque input to the clutch unit 6 is output from the turbine hub 43 via the drive plate 71, the torsion spring 73, and the driven plate 72.

[Dynamic vibration absorber]
The dynamic vibration absorber 15 is disposed between the lockup device 10 and the turbine 4. The dynamic vibration absorber 15 is attached to the turbine 4. Specifically, the dynamic vibration absorber 15 is attached to the turbine hub 43.

[Position sensor]
The position sensor 8 is attached to the housing 20. Specifically, the position sensor 8 is attached to the side wall portion of the housing 20. That is, the position sensor 8 is attached to the disc portion 21 of the front cover 2.

  The position sensor 8 detects the position of the clutch unit 6 in the axial direction. Specifically, the position sensor 8 detects the distance between the position sensor 8 and the piston 61 of the clutch unit 6. That is, the position sensor 8 is a distance sensor.

[Power receiving unit]
As shown in FIG. 1, the power reception unit 11 is electrically connected to the position sensor 8. Specifically, the power receiving unit 11 and the position sensor 8 are connected by wire with a wire or the like. The power receiving unit 11 is attached to the outer peripheral surface of the housing 20. Specifically, the power receiving unit 11 is attached to the outer peripheral surface of the first cylindrical portion 22 that constitutes the outer peripheral wall of the housing 20. The power receiving unit 11 is configured by, for example, a power receiving coil.

[Power transmission section]
The power transmission unit 12 is arranged at a distance from the power reception unit 11 outside the power reception unit 11 in the radial direction. For example, the power transmission unit 12 can be attached to the inner wall surface of the housing that houses the torque converter 100. The power transmission unit 12 is configured to transmit power to the power reception unit 11 in a contactless manner. That is, the power transmission unit 12 transmits power to the power reception unit 11 by wireless power feeding. Note that the wireless power feeding method between the power transmission unit 12 and the power receiving unit 11 may be a magnetic field coupling method, an electric field coupling method, or an electromagnetic field coupling method. The power transmission unit 12 is configured by a power transmission coil, for example.

[Control unit]
The control unit 13 acquires the position information of the clutch unit 6 detected by the position sensor 8. Specifically, the control unit 13 acquires the distance between the position sensor 8 and the piston 61 as position information of the clutch unit 6. Then, the control unit 13 displays a warning for warning that the friction material is worn based on the distance between the position sensor 8 and the piston 61 acquired by the position sensor 8.

  Next, the operation of the control unit 13 will be described. First, as shown in FIG. 2, the control unit 13 acquires the position information of the clutch unit 6 detected by the position sensor 8 by wireless communication (step S1). Specifically, the control unit 13 acquires information about the distance between the position sensor 8 and the piston 61 detected by the position sensor 8 by wireless communication. For this wireless communication, the torque converter 100 is provided with a wireless chip and an antenna (not shown), and the control unit 13 is provided with an antenna (not shown) to perform a digital modulation or analog modulation wireless communication system. Can be built. Note that this wireless communication may be a load modulation communication system via the power receiving unit 11 and the power transmission unit 12.

  The controller 13 determines whether or not the distance between the position sensor 8 detected by the position sensor 8 and the piston 61 is equal to or less than a preset threshold value (step S2).

  When the control unit 13 determines that the distance between the position sensor 8 detected by the position sensor 8 and the piston 61 is not equal to or less than the threshold value (No in step S2), the control unit 13 executes the process in step S1 again.

  When the control unit 13 determines that the distance between the position sensor 8 detected by the position sensor 8 and the piston 61 is equal to or less than the threshold value (Yes in step S2), the control unit 13 executes a warning display. For example, the control unit 13 performs a warning display to the effect that the friction material 82 is worn on the display device, and prompts the driver or maintenance worker to replace the friction material 82 or the torque converter 100.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention.

Modification 1
In the above embodiment, the position sensor 8 is attached to the side wall portion of the housing 20, but the attachment position is not limited to this. For example, the position sensor 8 may be attached to the outer peripheral wall portion of the housing 20 as shown in FIG. Specifically, the position sensor 8 is attached to the first cylindrical portion 22 of the front cover 2. The position sensor 8 faces the second cylindrical portion 612 of the piston 61.

  The position sensor 8 does not detect the distance between the position sensor 8 and the piston 61 but detects the presence or absence of the clutch portion 6. For this reason, the position sensor 8 faces the outer peripheral surface of the second cylindrical portion 612 of the piston 61 when the wear of the friction material 82 is not more than a certain amount, and the position sensor 8 The two cylindrical portions 612 are provided at positions that do not face the outer peripheral surface. When the second cylindrical portion 612 is no longer detected by the position sensor 8, the control unit 13 determines that the piston 61 has come closer to the disc portion 21 of the front cover 2 than a predetermined threshold value, and executes a warning display.

Modification 2
When the control unit 13 determines that the position of the clutch unit 6 is closer to the disk unit 21 of the front cover 2 than the threshold based on the position information of the clutch unit 6 detected by the position sensor 8, the friction member 82 and the disk The clutch portion 6 may be moved so as to release the frictional engagement with the portion 21.

Modification 3
In the above embodiment, the torque converter 100 has one position sensor 8, but the number of position sensors 8 is not limited to this. For example, as shown in FIG. 4, the torque converter 100 may include two position sensors 8a and 8b. The 1st position sensor 8a is attached to the side wall part 21 of the housing | casing 20, and has the structure similar to the position sensor 8 of the said embodiment. The second position sensor 8b is attached to the outer peripheral wall portion 22 of the housing 20, and has the same configuration as the position sensor 8 of the first modification.

  According to this configuration, the following control can be performed. When the distance between the position sensor 8 detected by the first position sensor 8a and the piston 61 is equal to or smaller than the threshold value, and the second cylindrical portion 612 is detected by the second position sensor 8b, the control unit 13 It is determined that the friction material 82 is not worn, but the piston 61 is deformed by the hydraulic pressure applied to the piston 61. That is, the control unit 13 determines that the hydraulic pressure applied to the piston 61 is an abnormal value. Then, the control unit 13 controls the control valve 14 in order to reduce the hydraulic pressure applied to the piston 61.

Modification 4
Although the outer peripheral wall part of the housing | casing 20 is mainly comprised by the 1st cylindrical part 22 of the front cover 2, it is not limited to this in particular. For example, the impeller shell 31 may have a disc part and a cylindrical part like the front cover 2. And the outer peripheral wall part of the housing | casing 20 may be comprised by the cylindrical part of this impeller shell 31, or a housing | casing is comprised by both the 1st cylindrical part 22 of the front cover 2, and the cylindrical part of the impeller shell 31. You may comprise 20 outer peripheral wall parts.

6: Clutch part 8: Position sensor 13: Control part 20: Housing 21: Side wall part 22: Outer peripheral wall part

Claims (7)

A power transmission device that transmits torque from a driving source to driving wheels,
Torque from the drive source is transmitted, and a housing that is rotatably arranged;
A clutch portion having a friction surface facing a first direction, arranged to be movable in the first direction in the housing, and engageable with the housing;
A position sensor for detecting the position of the clutch portion in the first direction;
A power transmission device comprising:
The first direction is along the rotation axis of the housing,
The power transmission device according to claim 1.
The position sensor is attached to a side wall portion of the casing facing the friction surface, and detects a distance from the clutch portion.
The power transmission device according to claim 2.
The position sensor is attached to an outer peripheral wall portion of the housing that is radially outward from the friction surface, and detects the presence or absence of the clutch portion.
The power transmission device according to claim 2.
A control unit that acquires position information of the clutch unit detected by the position sensor;
The power transmission device according to any one of claims 1 to 4.
When the control unit determines that the position of the clutch unit is closer to the side wall portion of the housing than the threshold value based on the position information, a warning is displayed.
The power transmission device according to claim 5.
When the control unit determines that the position of the clutch unit is closer to the side wall portion of the housing than the threshold based on the position information, the control portion releases the frictional engagement between the friction surface and the side wall portion of the housing. Move the clutch section so that
The power transmission device according to claim 5 or 6.

Images