JP2015140864A - Centrifugal cancellation structure of power transmission clutch for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal cancellation structure of a power transmission clutch for an automatic transmission, capable of always holding a working medium in a centrifugal cancellation chamber without using an oil pump, and capable of obtaining a centrifugal pressure sufficient to cancel a centrifugal pressure generated in a working fluid in an engagement hydraulic chamber irrespective of a clutch engagement state.SOLUTION: A centrifugal cancellation structure (46) of a power transmission clutch for an automatic transmission comprises: an input shaft (14) to which power is input; a transmission mechanism (16) disposed around the input shaft (14); and a power transmission clutch (18, 20, 22) including an engagement hydraulic chamber (58) to which a working fluid is supplied, an engagement piston (56) receiving a hydraulic pressure by this working fluid, and a centrifugal cancellation chamber (64) provided on an opposite side to the engagement hydraulic chamber (58) across the engagement piston (56), a volumetric change permission unit (68) permitting a volumetric change of an interior of the centrifugal cancellation chamber (64) in response to movement of the engagement piston (56) receiving the hydraulic pressure of the engagement hydraulic chamber (58) being provided at the centrifugal cancellation chamber (64).

Description

  The present invention relates to a centrifugal cancel structure for a power transmission clutch, and more particularly to a centrifugal cancel structure for a power transmission clutch for an automatic transmission.

  Conventionally, an automatic transmission that shifts and outputs power generated by an engine is known. The automatic transmission includes an input shaft to which power generated by the engine is input via a fluid transmission device, a plurality of planetary gear sets for increasing and decreasing the speed of power input to the input shaft, and A clutch for connecting / disconnecting the input shaft to the rotating element included in the planetary gear set, and a brake for fixing the rotating element. By selectively engaging and controlling the clutch and the brake, a plurality of forward shift speeds and reverse gears are provided. The gear stage is realized.

  The clutch includes a friction plate that frictionally fastens the input shaft and the rotating element, a fastening piston that presses the friction plate in the axial direction of the input shaft, and a fastening that is supplied with hydraulic pressure (hydraulic oil) for pressing the fastening piston. It has a hydraulic chamber. Since the engagement hydraulic chamber of the clutch rotates around the input shaft, a centrifugal pressure is generated in the hydraulic oil supplied to the engagement hydraulic chamber. Due to the centrifugal pressure, the fastening piston presses the friction plate in the fastening direction, and the clutch may be erroneously fastened. Therefore, in order to prevent erroneous engagement of the clutch due to centrifugal pressure, a centrifugal cancel chamber is provided on the opposite side of the fastening hydraulic chamber with respect to the fastening piston in the direction in which the input shaft extends (see, for example, Patent Document 1). .

  Further, by providing a check valve in the oil passage through which hydraulic oil is supplied to and discharged from the centrifugal cancel chamber, an oil pump that supplies hydraulic oil to the clutch engagement hydraulic chamber and the centrifugal cancel chamber when the engine is stopped. Even when the operation is stopped, a predetermined amount of hydraulic oil is always stored in the centrifugal cancel chamber (see, for example, Patent Document 2).

JP 2010-048318 A Japanese Patent Laid-Open No. 1-210623

  However, since the hydraulic oil must be continuously supplied to the centrifugal cancel chamber as described above using an oil pump driven by an engine or a motor, it causes a deterioration in fuel consumption.

  Accordingly, it is conceivable that the centrifugal cancel chamber is hermetically sealed, and the hydraulic oil is enclosed in the centrifugal cancel chamber in advance, thereby making it unnecessary to supply the hydraulic oil to the centrifugal cancel chamber. Since the volume of the centrifugal cancel chamber changes according to the movement of the fastening piston and becomes the minimum when the clutch is engaged, the volume of hydraulic oil pre-filled in the centrifugal cancel chamber is the volume of the centrifugal cancel chamber at the minimum. It is necessary to do the following. In this case, when the clutch is released and the volume of the centrifugal cancel chamber becomes maximum, the amount of hydraulic oil in the centrifugal cancel chamber is insufficient, and is sufficient to offset the centrifugal pressure generated in the hydraulic fluid in the fastening hydraulic chamber. Centrifugal pressure may not be obtained.

  The present invention has been made to solve the above-described problems of the prior art, and can improve fuel efficiency by always holding the working medium in the centrifugal cancel chamber without using an oil pump, and To provide a centrifugal cancel structure of a power transmission clutch for an automatic transmission capable of obtaining a centrifugal pressure sufficient to cancel out the centrifugal pressure generated in the hydraulic oil in the engagement hydraulic chamber regardless of the engagement state of the clutch. Objective.

In order to achieve the above object, a centrifugal cancel structure for a power transmission clutch according to the present invention is a centrifugal cancel structure for a power transmission clutch for an automatic transmission, to which power generated by a power source is input. An input shaft, a speed change mechanism arranged around the input shaft, a power transmission clutch that transmits power to the speed change mechanism, a fastening hydraulic chamber to which hydraulic oil is supplied, and a hydraulic pressure by the hydraulic oil Power transmission having a fastening piston having a pressure receiving surface and a centrifugal canceling chamber provided on the opposite side of the fastening hydraulic chamber with respect to the fastening piston along the direction in which the input shaft extends, and in which a fluid medium is enclosed. The centrifugal cancel chamber is provided with a volume change permitting portion that allows a volume change in the centrifugal cancel chamber accompanying the movement of the fastening piston that receives the hydraulic pressure of the fastening hydraulic chamber. It is characterized in.
In the present invention configured as described above, the centrifugal cancel chamber is provided with a volume change allowing portion that allows a volume change in the centrifugal cancel chamber accompanying the movement of the fastening piston that receives the hydraulic pressure of the fastening hydraulic chamber. Even if the volume of the centrifugal cancel chamber changes according to the movement of the piston, the inside of the centrifugal cancel chamber can always be maintained in a state filled with the fluid medium, and the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber is offset. A sufficient centrifugal pressure can be applied to the fastening piston. Accordingly, fuel efficiency can be improved by constantly holding the working medium in the centrifugal cancel chamber without using an oil pump, and the centrifugal pressure generated in the hydraulic fluid in the engagement hydraulic chamber can be reduced regardless of the clutch engagement state. Sufficient centrifugal pressure can be obtained to cancel.

In the present invention, it is preferable that the volume change allowing portion is a protrusion fluidly connected to the centrifugal cancel chamber, and the protrusion of the centrifugal cancel chamber is the centrifugal cancel chamber when the fastening piston moves in the fastening direction. A part of the hydraulic oil is accumulated, and when the fastening piston moves in the direction opposite to the fastening direction, the hydraulic oil accumulated in the protruding portion is returned to the centrifugal cancel chamber.
In the present invention configured as described above, the volume change allowing portion is a protruding portion that is fluidly connected to the centrifugal cancel chamber, and the protruding portion of the hydraulic oil in the centrifugal cancel chamber is moved in accordance with the movement of the fastening piston. A part of the hydraulic oil accumulated in the protruding portion is returned to the centrifugal cancel chamber, so that even if the volume of the centrifugal cancel chamber changes according to the movement of the fastening piston, the inside of the centrifugal cancel chamber is always fluid. The state in which the medium is filled with the medium can be maintained, and sufficient centrifugal pressure can be applied to the fastening piston to offset the centrifugal pressure caused by the hydraulic oil in the fastening hydraulic chamber.

In the present invention, it is preferable that the volume change allowing portion is an elastic deforming portion that allows a volume change in the centrifugal cancel chamber accompanying the movement of the fastening piston by elastic deformation, and the elastic deforming portion of the centrifugal cancel chamber is an input. It is configured to expand and contract in the same direction as the direction in which the shaft extends to allow a volume change in the centrifugal cancel chamber.
In the present invention configured as described above, the volume change allowing portion elastically deforms so as to expand and contract in the same direction as the direction in which the input shaft extends to allow the volume change in the centrifugal cancel chamber accompanying the movement of the fastening piston. Therefore, even if the volume in the centrifugal cancel chamber changes according to the movement of the fastening piston, the fluid medium inside the volume change allowable portion can be pushed out into the centrifugal cancel chamber by the elastic force of the volume change allowable portion. The centrifugal cancellation chamber can be reliably maintained in a state filled with a fluid medium, and a centrifugal pressure sufficient to cancel the centrifugal pressure caused by the hydraulic oil in the fastening hydraulic chamber can be applied to the fastening piston. it can.
Further, when the volume change allowing portion (elastic deformation portion) of the centrifugal cancel chamber is configured to expand and contract in the radial direction of the input shaft, the volume is generated by centrifugal force generated by the rotation of the centrifugal cancel chamber around the input shaft. The change allowance portion expands and unnecessarily accommodates the fluid medium in the centrifugal cancel chamber inside the volume change allowance portion. In the present invention, the volume change allowance portion is in the same direction as the direction in which the input shaft extends. Since it is elastically deformed so as to expand and contract, it is possible to prevent the centrifugal cancel chamber from being affected by the centrifugal force rotating around the input shaft.

  According to the centrifugal cancel structure of the power transmission clutch for an automatic transmission according to the present invention, the fuel consumption can be improved by always holding the working medium in the centrifugal cancel chamber without using an oil pump, and the clutch. A centrifugal pressure sufficient to cancel out the centrifugal pressure generated in the hydraulic oil in the fastening hydraulic chamber can be obtained regardless of the fastening state.

It is the skeleton figure which looked at the horizontal section which passes along the central axis of the automatic transmission which applied the centrifugal cancellation structure by a 1st embodiment of the present invention from the upper part. 2 is a fastening table of the automatic transmission shown in FIG. 1. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 1st Embodiment of this invention is applied. It is a perspective view of the elastic deformation part of the centrifugal cancellation structure by 1st Embodiment of this invention. It is a perspective view of the elastic deformation part of the centrifugal cancellation structure by 1st Embodiment of this invention. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 1st Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 1st Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 2nd Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 2nd Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 2nd Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 3rd Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 3rd Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 3rd Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 4th Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 4th Embodiment of this invention is applied. It is a partial expanded sectional view of the clutch for power transmission to which the centrifugal cancellation structure by 4th Embodiment of this invention is applied.

Hereinafter, a centrifugal cancel structure of a power transmission clutch for an automatic transmission according to an embodiment of the present invention will be described with reference to the accompanying drawings.
First, an overall configuration of an automatic transmission to which the centrifugal cancel structure according to the first embodiment of the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a skeleton diagram of a horizontal section passing through the central axis of an automatic transmission to which a centrifugal canceling structure according to a first embodiment of the present invention is applied, and FIG. 2 is an automatic transmission shown in FIG. This is a conclusion table.

First, in FIG. 1, the code | symbol 1 has shown the powertrain structure. This powertrain structure 1 is applied to a front-wheel drive vehicle (FF vehicle) in which an engine 2 is mounted horizontally on the front portion of the vehicle. An arrow FR in FIG. 1 indicates the traveling direction of the FF vehicle to which the powertrain structure 1 is applied.
An automatic transmission 8 is connected to the output shaft 4 of the engine 2 which is a power source of the vehicle via a torque converter 6. A counter mechanism 10 is connected to the output side of the automatic transmission 8, and the differential mechanism 12 is driven by power output from the automatic transmission 8 via the counter mechanism 10.

The automatic transmission 8 includes an input shaft 14 to which power generated by the engine 2 is input via the torque converter 6, and a transmission mechanism 16 is disposed around the input shaft 14.
The automatic transmission 8 includes a first clutch 18, a second clutch 20, and a third clutch 22 that transmit power input from the output shaft 4 of the engine 2 to the input shaft 14 of the automatic transmission 8 to the transmission mechanism 16. I have. The second clutch 20 transmits the power input to the input shaft 14 to the transmission mechanism 16, the first clutch 18 and the third clutch 22. The first clutch 18 and the third clutch 22 transmit the power input from the second clutch 20 to the transmission mechanism 16. In addition, the automatic transmission 8 includes a first brake 24 and a second brake 26 that limit the operation of a rotating element included in the transmission mechanism 16.
Further, an output gear 28 that outputs power from the transmission mechanism 16 is disposed between the transmission mechanism 16 and the second clutch 20.

  The input shaft 14, the transmission mechanism 16, the clutches 18, 20 and 22, the brakes 24 and 26, and the output gear 28 are stored in the transmission case 30. The transmission case 30 includes a case portion 32 formed around the input shaft 14, the transmission mechanism 16, the clutches 18, 20 and 22, the brakes 24 and 26, and the output gear 28, and the case portion 32 on the engine 2 side. And a housing portion 34 attached to the end surface of the housing. The housing portion 34 is formed so that the outer diameter increases from the end surface of the case portion 32 toward the engine 2. The torque converter 6 is accommodated in the housing portion 34.

The transmission mechanism 16 includes a first planetary gear set 36, a second planetary gear set 38, a third planetary gear set 40, and a fourth planetary gear set 42 disposed around the input shaft 14. Of these planetary gear sets 36, 38, 40, 42, the second planetary gear set 38 is disposed so as to overlap the outer periphery of the third planetary gear set 40, and the second planetary gear set 38, the third planetary gear set 40, Thus, a multi-stage planetary gear set 44 is configured.
These planetary gear sets 36, 38, 40, 42 are arranged in a multi-stage planetary gear set 44, a first planetary gear set 36, a fourth planetary gear from the side far from the engine 2 toward the engine 2 along the direction in which the input shaft 14 extends. The output gear 28 is arranged adjacent to the engine 2 side of the fourth planetary gear set 42.
Each planetary gear set 36, 38, 40, 42 includes an external gear sun gear 36a, 38a, 40a, 42a, a plurality of planetary pinions meshed with the sun gears 36a, 38a, 40a, 42a, and these planetary pinions. Carriers 36b, 38b, 40b, 42b to be supported and ring gears 36c, 38c, 40c, 42c of internal gears meshed with pinions are provided.

  The input shaft 14 is connected to the carrier 40b of the third planetary gear set 40, the carrier 38b of the second planetary gear set 38 and the carrier 42b of the fourth planetary gear set 42 are connected, and the carrier of the first planetary gear set 36 is connected. 36b and the ring gear 42c of the fourth planetary gear set 42 are coupled, and the carrier 42b of the fourth planetary gear set 42 and the output gear 28 are coupled.

  The second clutch 20 is disposed on the engine 2 side of the output gear 28, the first clutch 18 and the third clutch 22 are adjacent to the multi-stage planetary gear set 44, and the first clutch 18 is connected to the third clutch 22. It arrange | positions so that it may overlap with the outer peripheral part.

The sun gear 36 a, the first clutch 18, and the third clutch 22 of the first planetary gear set 36 are respectively connected to the output shaft 20 a of the second clutch 20, whereby the input shaft is connected via the second clutch 20. 14 is connected to be connectable.
Further, the ring gear 38c of the second planetary gear set 38 is connected to the output shaft 18a of the first clutch 18, so that it can be connected to the input shaft 14 via the first clutch 18 and the second clutch 20. Has been.
The sun gear 38a of the second planetary gear set 38 (that is, the ring gear 40c of the third planetary gear set 40) is connected to the output shaft 22a of the third clutch 22, whereby the third clutch 22 and the second clutch 20 are connected. It is connected to the input shaft 14 via the via.

The first brake 24 is fixed to the inner periphery of the case portion 32 between the second clutch 20 and the output gear 28, and the sun gear 40a of the third planetary gear set 40 and the sun gear 42a of the fourth planetary gear set 42 Connected to limit the operation of these sun gears 40a, 42a.
The second brake 26 is fixed to the inner periphery of the case portion 32 at the outer periphery of the ring gear 36c of the first planetary gear set 36, and is connected to the ring gear 36c of the first planetary gear set 36 to operate the ring gear 36c. Limit.

  A desired forward shift speed or reverse shift speed is obtained by a combination of the engagement states of the first clutch 18, the second clutch 20, the third clutch 22, the first brake 24, and the second brake 26 described above. The automatic transmission 8 of the present embodiment can output eight forward speeds and reverse speeds as shown in the fastening table of FIG. 2 indicates that the clutches 18, 20, 22 or the brakes 24, 26 are in the engaged state, and no mark indicates that the clutches 18, 20, 22 or the brakes 24, 26 are in the released state. It shows that there is.

  For example, at the first speed of the automatic transmission 8, the first clutch 18 and the third clutch 22 are released, and the second clutch 20, the first brake 24, and the second brake 26 are engaged. Thereby, the rotation of the input shaft 14 is transmitted to the carrier 40 b of the third planetary gear set 40 and also transmitted to the sun gear 36 a of the first planetary gear set 36 via the second clutch 20. The rotation of the sun gear 36 a is decelerated and output from the carrier 36 b of the first planetary gear set 36 to the ring gear 42 c of the fourth planetary gear set 42. The rotation of the ring gear 42c is decelerated and output from the carrier 42b of the fourth planetary gear set 42 to the output gear 28.

Next, a centrifugal canceling structure of a power transmission clutch for an automatic transmission according to a first embodiment of the present invention will be described with reference to FIGS.
The centrifugal cancel structure according to the first embodiment can be applied to any of the first clutch 18, the second clutch 20, and the third clutch 22. FIGS. 3 to 6 show the centrifugal cancel according to the first embodiment. The 3rd clutch 22 to which the structure was applied is illustrated. Specifically, FIG. 3 is a partially enlarged cross-sectional view showing the third clutch 22 in an opened state when the input shaft 14 is stopped, and FIG. 6 is a diagram when the input shaft 14 is rotating. FIG. 7 is a partial enlarged cross-sectional view showing the third clutch 22 in the released state, and FIG. 7 is a partial enlarged cross-sectional view showing the third clutch 22 in the engaged state when the input shaft 14 is rotating. FIGS. 4 and 5 are perspective views of the elastically deforming portion of the centrifugal cancel structure shown in FIGS. 3, 6, and 7.

First, as shown in FIGS. 3, 6, and 7, the third clutch 22 to which the centrifugal cancel structure 46 according to the present embodiment is applied includes a clutch drum 48 coupled to the input shaft 14, and the third clutch. And a clutch hub 50 coupled to 22 output shafts 22a.
A spline 50a extending along the axial direction of the input shaft 14 is provided on the outer periphery of the clutch hub 50, and a plurality of friction plates 52 are slidably fitted along the spline 50a. A spline 48a extending along the axial direction of the input shaft 14 is provided on the inner periphery of the clutch drum 48, and a plurality of friction mating plates 54 extend along the spline 48a so as to sandwich the friction plates 52 alternately. Are slidably fitted. Further, the friction mating plate 54 (the rightmost friction mating plate 54 in FIGS. 3, 6, and 7) located at one end in the extending direction of the input shaft 14 is a snap ring fixed to the clutch drum 48. 48b regulates sliding along the spline 48a.

  Inside the clutch drum 48, it operates in the fastening direction (the right direction in FIGS. 3, 6, and 7) that presses the friction plate 52 and the friction counterpart plate 54 together along the axial direction of the input shaft 14. A cylindrical fastening piston 56 is provided. The fastening piston 56 is in close contact with the inner periphery of the clutch drum 48 via a seal ring 56 a provided on the outer periphery thereof, and is formed to be slidable along the axial direction of the input shaft 14. A pressing portion 56b that presses the friction mating plate 54 is formed at a position opposite to. A fastening hydraulic chamber 58 to which hydraulic oil for controlling the fastening of the fastening piston 56 is supplied is formed between the fastening piston 56 and the clutch drum 48. The surface of the fastening piston 56 that faces the fastening hydraulic chamber 58 is a pressure receiving surface 56 c that receives the hydraulic pressure of the hydraulic oil supplied to the fastening hydraulic chamber 58. The hydraulic oil is supplied to the fastening hydraulic chamber 58 from the valve body disposed in the vicinity of the automatic transmission 8 through the oil passage 60.

  A seal plate 62 is provided on the opposite side of the fastening hydraulic chamber 58 with respect to the fastening piston 56 along the direction in which the input shaft 14 extends so as to face the pressure receiving surface 56 c of the fastening piston 56. The seal plate 62 is fixed to the input shaft 14 by a snap ring 62a, and is formed so as to be in close contact with the inner periphery of the cylindrical fastening piston 56 via a seal ring 62b provided on the outer periphery thereof. A centrifugal cancel chamber 64 is formed as a sealed region surrounded by the seal plate 62, the fastening piston 56, and the outer periphery of the input shaft 14. Inside the centrifugal cancel chamber 64 is fixed to the seal plate 62 and attached in a releasing direction (leftward in FIGS. 3, 6, and 7) that moves the fastening piston 56 away from the friction plate 52 and the friction counterpart plate 54. A return spring 66 is provided.

  Further, the centrifugal cancel chamber 64 has a volume change allowing portion 68 (elastic deformation portion) that allows a volume change in the centrifugal cancel chamber 64 due to the movement of the fastening piston 56 that receives the hydraulic pressure of the fastening hydraulic chamber 58 by elastic deformation. Is provided. As shown in FIGS. 3 and 4, the volume change allowing portion 68 is a cylindrical shape formed so as to protrude from the seal plate 62 to the opposite side of the centrifugal cancel chamber 64 along the axial direction of the input shaft 14. An opening 62c is formed in the seal plate 62 so as to include a side wall portion 70 and an end surface 72 covering the tip of the side wall portion 70 so that the inside of the volume change allowing portion 68 is in fluid communication with the centrifugal cancel chamber 64. Yes. A fluid medium similar to the hydraulic oil supplied to the fastening hydraulic chamber 58 is enclosed in the centrifugal cancel chamber 64 and the volume change allowing portion 68. The surface of the fastening piston 56 that faces the centrifugal cancel chamber 64 is a pressure receiving surface 56 d that receives the pressure of the fluid medium sealed in the centrifugal cancel chamber 64.

The side wall portion 70 is formed of, for example, a metal or nonmetal (rubber or resin) bellows, and extends in the same direction as the direction in which the input shaft 14 extends as shown in FIG. As shown in (b), it contracts to allow the volume change in the centrifugal cancel chamber 64 to be allowed. That is, the length by which the side wall part 70 expands and contracts and the inner diameter of the side wall part 70 are set based on the amount of change in the volume in the centrifugal cancel chamber 64 as the fastening piston 56 moves. More specifically, the volume change amount of the volume change allowing portion 68 according to the expansion and contraction of the side wall portion 70 is set to be equal to the volume change amount in the centrifugal cancel chamber 64.
The side wall portion 70 urges the end surface 72 in the contraction direction toward the centrifugal cancel chamber 64 (leftward in FIGS. 3, 6, and 7) by its elastic force. In addition, the side wall part 70 may be formed by the coil spring extended along the axial direction of the input shaft 14, and the flexible member which covers the coil spring from the outer peripheral side.

  As shown in FIG. 4, the seal plate 62 is provided with a plurality (14 in FIG. 4) of cylindrical volume change allowances 68 formed as described above at equal intervals in the circumferential direction. . Alternatively, as shown in FIG. 5, one annular volume change allowing portion 68 arranged around the input shaft 14 may be attached to the seal plate 62.

Next, the operation of the centrifugal cancel structure 46 according to the first embodiment of the present invention described above will be described.
First, when the input shaft 14 is stopped and hydraulic oil is not supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement piston 56 of the third clutch 22 is moved in the engagement direction (right in FIG. 3). As shown in FIG. 3, the engagement piston 56 of the third clutch 22 moves in the release direction (left direction in FIG. 3) due to the elastic force of the return spring 66, causing friction. The plate 52 and the friction counterpart plate 54 are maintained in a non-contact release state.

  At this time, the volume of the centrifugal cancel chamber 64 increases as the distance between the fastening piston 56 and the seal plate 62 increases. Along with this, the side wall 70 of the volume change allowing portion 68 contracts due to its elastic force and pushes the fluid medium stored in the volume change allowing portion 68 into the centrifugal cancel chamber 64. Thereby, the inside of the centrifugal cancel chamber 64 is maintained in a state filled with the fluid medium.

Next, when the input shaft 14 is rotating and hydraulic oil is not supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement hydraulic chamber 58 of the third clutch 22 is also rotated together with the input shaft 14. Therefore, a centrifugal pressure is generated in the hydraulic oil in the fastening hydraulic chamber 58, and the fastening piston 56 is pressed in the fastening direction (in the right direction in FIG. 6) to press the friction plate 52 and the friction counterpart plate 54 by this centrifugal pressure. The
On the other hand, since the centrifugal cancel chamber 64 also rotates together with the input shaft 14, a centrifugal pressure is generated in the fluid medium in the centrifugal cancel chamber 64, and this centrifugal pressure is released in the release direction (leftward in FIG. 6). ) To cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58.
As described above, the inside of the centrifugal cancel chamber 64 is maintained in a state filled with the fluid medium pushed into the centrifugal cancel chamber 64 from the volume change allowing portion 68. Accordingly, a centrifugal pressure sufficient to cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58 acts on the fastening piston 56 from the centrifugal cancel chamber 64.
As a result, the engagement piston 56 of the third clutch 22 is reliably pressed in the release direction (leftward in FIG. 6) by the return spring 66 as shown in FIG. 6, and the friction plate 52 and the friction counterpart plate 54 do not contact each other. Maintained in the released state.

Next, when the input shaft 14 is rotating and hydraulic fluid is supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement hydraulic chamber 58 of the third clutch 22 is also rotating together with the input shaft 14. Therefore, a centrifugal pressure is generated in the hydraulic oil in the fastening hydraulic chamber 58, and the fastening piston 56 is pressed in the fastening direction (in the right direction in FIG. 7) that presses the friction plate 52 and the friction counterpart plate 54 by this centrifugal pressure. . However, since the centrifugal cancel chamber 64 also rotates together with the input shaft 14, a centrifugal pressure is generated in the fluid medium in the centrifugal cancel chamber 64, and this centrifugal pressure is released from the fastening piston 56 (leftward in FIG. 7). ) To cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58. As a result, as shown in FIG. 7, the engagement piston 56 of the third clutch 22 moves in the engagement direction (rightward in FIG. 7) due to the hydraulic pressure of the hydraulic oil supplied from the valve body to the engagement hydraulic chamber 58. The plate 52 and the friction mating plate 54 are maintained in the fastened state in contact with each other. That is, the engagement state of the third clutch 22 is appropriately controlled according to the hydraulic control by the valve body.
Moreover, when the fastening piston 56 of the third clutch 22 moves in the fastening direction, the distance between the fastening piston 56 and the seal plate 62 is reduced, and the volume of the centrifugal cancel chamber 64 is reduced accordingly. Accordingly, the side wall portion 70 of the volume change allowing portion 68 expands against the elastic force, and the fluid medium pushed out from the centrifugal cancel chamber 64 is accommodated in the volume change allowing portion 68. Accordingly, even when the volume of the centrifugal cancel chamber 64 is reduced by moving the fastening piston 56 in the fastening direction as shown in FIG. 7, the movement of the fastening piston 56 is prevented by the fluid medium in the centrifugal cancel chamber 64. Absent.

Next, effects of the centrifugal cancel structure 46 according to the first embodiment of the present invention described above will be described.
First, since the volume change allowing portion 68 that allows the volume change in the centrifugal cancel chamber 64 due to the movement of the fastening piston 56 that receives the hydraulic pressure of the fastening hydraulic chamber 58 is provided in the centrifugal cancel chamber 64, Even if the volume in the centrifugal cancel chamber 64 changes according to the movement, the inside of the centrifugal cancel chamber 64 can always be maintained in a state filled with the fluid medium, and the centrifugal pressure by the hydraulic oil in the fastening hydraulic chamber 58 can be maintained. Sufficient centrifugal pressure can be applied to the fastening piston 56 to offset Thereby, the fuel consumption can be improved by always holding the working medium in the centrifugal cancel chamber 64 without using an oil pump, and the engagement hydraulic chamber 58 regardless of the engagement state of the clutches 18, 20, 22. Sufficient centrifugal pressure can be obtained to offset the centrifugal pressure generated in the hydraulic fluid.

In particular, the volume change allowing portion 68 is elastically deformed so as to expand and contract in the same direction as the direction in which the input shaft 14 extends. The centrifugal cancel chamber 64 can be reliably maintained in a state filled with the fluid medium, which is sufficient to cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58. Centrifugal pressure can be applied to the fastening piston 56.
Further, when the volume change allowing portion 68 is configured to expand and contract in the radial direction of the input shaft 14, the volume change allowing portion 68 is caused by the centrifugal force generated by the rotation of the centrifugal cancel chamber 64 around the input shaft 14. The fluid medium in the centrifugal cancel chamber 64 is unnecessarily accommodated inside the volume change allowing portion 68, but in the first embodiment of the present invention, the volume change allowing portion 68 extends from the input shaft 14. Since it is elastically deformed so as to expand and contract in the same direction as the direction, it is possible to prevent the centrifugal cancel chamber 64 from being influenced by the centrifugal force generated around the input shaft 14 from rotating.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the configuration of the volume change allowing portion 68 in the first embodiment described above is different, and the other configurations are the same. Therefore, only different points will be described here. FIG. 8 is a partial enlarged cross-sectional view showing the third clutch 22 in the released state when the input shaft 14 is stopped, and FIG. 9 is a diagram showing the first state in the opened state when the input shaft 14 is rotating. FIG. 10 is a partially enlarged sectional view showing the third clutch 22, and FIG. 10 is a partially enlarged sectional view showing the third clutch 22 in the engaged state when the input shaft 14 is rotating.

  According to the second embodiment, as shown in FIGS. 8 to 10, the centrifugal cancel chamber 64 has a volume change in the centrifugal cancel chamber 64 due to the movement of the fastening piston 56 that receives the hydraulic pressure of the fastening hydraulic chamber 58. A volume change allowing portion 68 (protruding portion) is provided. As shown in FIGS. 8 to 10, the volume change allowing portion 68 includes a cylindrical side wall portion 70 formed so as to protrude to the opposite side of the centrifugal cancel chamber 64 along the axial direction of the input shaft 14, and An opening 62c is formed in the seal plate 62 so that the inside of the volume change allowing portion 68 is in fluid communication with the centrifugal cancel chamber 64. The side wall portion 70 of the volume change allowing portion 68 is formed of a rigid body that does not deform, and the length and inner diameter in the longitudinal direction are based on the amount of change in the volume in the centrifugal cancel chamber 64 as the fastening piston 56 moves. Is set. More specifically, the volume of the volume change allowing portion 68 is set to be equal to or larger than the change amount of the volume in the centrifugal cancel chamber 64.

  A compressive fluid 74 (for example, a gas such as air) is sealed inside the volume change allowable portion 68, and the volume change allowable portion 68 and the volume change allowable portion 68 are expanded or compressed. A change in volume in the centrifugal cancel chamber 64 that is in fluid communication is allowed.

Next, the operation of the centrifugal cancel structure 46 according to the second embodiment of the present invention described above will be described.
First, when the input shaft 14 is stopped and hydraulic oil is not supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement piston 56 of the third clutch 22 is moved as shown in FIG. The elastic force of the return spring 66 moves in the release direction (leftward in FIG. 8), and the friction plate 52 and the friction counterpart plate 54 are maintained in a non-contact release state.

  At this time, the volume of the centrifugal cancel chamber 64 increases as the distance between the fastening piston 56 and the seal plate 62 increases. Along with this, the compressive fluid 74 in the volume change allowing portion 68 expands and pushes the fluid medium stored in the volume change allowing portion 68 into the centrifugal cancel chamber 64. Thereby, the inside of the centrifugal cancel chamber 64 is maintained in a state filled with the fluid medium.

Next, when the input shaft 14 is rotating and hydraulic oil is not supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement hydraulic chamber 58 of the third clutch 22 is also rotated together with the input shaft 14. Therefore, a centrifugal pressure is generated in the hydraulic oil in the fastening hydraulic chamber 58, and the fastening piston 56 is pressed in the fastening direction (in the right direction in FIG. 9) to press the friction plate 52 and the friction counterpart plate 54 by this centrifugal pressure. The
On the other hand, since the centrifugal cancel chamber 64 also rotates together with the input shaft 14, a centrifugal pressure is generated in the fluid medium in the centrifugal cancel chamber 64, and this centrifugal pressure is released in the release direction (leftward in FIG. 9). ) To cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58.
As described above, the inside of the centrifugal cancel chamber 64 is maintained in a state filled with the fluid medium pushed into the centrifugal cancel chamber 64 from the volume change allowing portion 68. Accordingly, a centrifugal pressure sufficient to cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58 acts on the fastening piston 56 from the centrifugal cancel chamber 64.
As a result, the engagement piston 56 of the third clutch 22 is reliably pressed in the release direction (leftward in FIG. 9) by the return spring 66 as shown in FIG. 9, and the friction plate 52 and the friction counterpart plate 54 do not contact each other. Maintained in the released state.

Next, when the input shaft 14 is rotating and hydraulic fluid is supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement hydraulic chamber 58 of the third clutch 22 is also rotating together with the input shaft 14. Therefore, a centrifugal pressure is generated in the hydraulic oil in the fastening hydraulic chamber 58, and the fastening piston 56 is pressed in the fastening direction (rightward in FIG. 10) that presses the friction plate 52 and the friction counterpart plate 54 by this centrifugal pressure. . However, since the centrifugal cancel chamber 64 also rotates together with the input shaft 14, a centrifugal pressure is generated in the fluid medium in the centrifugal cancel chamber 64, and this centrifugal pressure is released in the release direction (leftward in FIG. 10). ) To cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58. As a result, as shown in FIG. 10, the engagement piston 56 of the third clutch 22 is moved in the engagement direction (rightward in FIG. 10) by the hydraulic pressure of the hydraulic oil supplied from the valve body to the engagement hydraulic chamber 58, and friction is generated. The plate 52 and the friction mating plate 54 are maintained in the fastened state in contact with each other. That is, the engagement state of the third clutch 22 is appropriately controlled according to the hydraulic control by the valve body.
Moreover, when the fastening piston 56 of the third clutch 22 moves in the fastening direction, the distance between the fastening piston 56 and the seal plate 62 is reduced, and the volume of the centrifugal cancel chamber 64 is reduced accordingly. Accordingly, the compressible fluid 74 in the volume change allowing portion 68 is compressed, and the fluid medium pushed out from the centrifugal cancel chamber 64 is accommodated in the volume change allowing portion 68. Therefore, even when the volume of the centrifugal cancel chamber 64 is reduced due to the fastening piston 56 moving in the fastening direction as shown in FIG. 10, the movement of the fastening piston 56 is prevented by the fluid medium in the centrifugal cancel chamber 64. Absent.

  As described above, according to the second embodiment, the volume change allowing portion 68 is a protruding portion that is in fluid communication with the centrifugal cancel chamber 64, and is enclosed in the volume change allowing portion 68 according to the movement of the fastening piston 56. The compressed compressive fluid 74 is compressed or expanded, so that a part of the hydraulic oil in the centrifugal cancel chamber 64 is accumulated, or the hydraulic oil accumulated in the volume change allowing portion 68 is accumulated in the centrifugal cancel chamber 64. Therefore, even if the volume in the centrifugal cancel chamber 64 changes according to the movement of the fastening piston 56, the inside of the centrifugal cancel chamber 64 can always be maintained in a state filled with the fluid medium, and the fastening hydraulic chamber 58 can be maintained. Sufficient centrifugal pressure can be applied to the fastening piston 56 to cancel out the centrifugal pressure caused by the hydraulic fluid inside.

  Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, the configuration of the volume change allowing portion 68 in the second embodiment described above is different, and the other configurations are the same. Therefore, only the different points will be described here. FIG. 11 is a partially enlarged cross-sectional view showing the third clutch 22 in the released state when the input shaft 14 is stopped, and FIG. 12 is a diagram showing the first state in the opened state when the input shaft 14 is rotating. FIG. 13 is a partially enlarged sectional view showing the third clutch 22, and FIG. 13 is a partially enlarged sectional view showing the third clutch 22 in an engaged state when the input shaft 14 is rotating.

  According to the third embodiment, as shown in FIGS. 11 to 13, the volume change allowing portion 68 is formed to protrude to the opposite side of the centrifugal cancel chamber 64 along the axial direction of the input shaft 14. A cylindrical side wall 70, an end surface 72 that covers the tip of the side wall 70, a piston 76 that slides on the inner periphery of the side wall 70 along the longitudinal direction of the side wall 70, and the piston 76 and the end surface 72 And a spring 78 that urges the piston 76 toward the centrifugal cancel chamber 64 (left side in FIGS. 11 to 13), and the inside of the volume change allowing portion 68 is connected to the centrifugal cancel chamber 64 and the fluid. An opening 62c is formed in the seal plate 62 so as to communicate with each other. The side wall portion 70 of the volume change allowing portion 68 is formed of a rigid body that does not deform. The piston 76 of the volume change allowance portion 68 moves and the volume in the volume change allowance portion 68 fluctuates, so that the volume change in the centrifugal cancel chamber 64 that is in fluid communication with the volume change allowance portion 68 is allowed. It is supposed to be.

Next, the operation of the centrifugal cancel structure 46 according to the above-described third embodiment of the present invention will be described.
First, when the input shaft 14 is stopped and the hydraulic oil is not supplied to the engagement hydraulic chamber 58 of the third clutch 22, as shown in FIG. The elastic force of the return spring 66 moves in the release direction (left direction in FIG. 11), and the friction plate 52 and the friction counterpart plate 54 are maintained in a non-contact release state.

  At this time, the volume of the centrifugal cancel chamber 64 increases as the distance between the fastening piston 56 and the seal plate 62 increases. Along with this, the piston 76 in the volume change allowing portion 68 moves to the centrifugal cancel chamber 64 side (leftward in FIG. 11) by the elastic force of the spring 78 and is stored in the volume change allowing portion 68. The medium is pushed into the centrifugal cancel chamber 64. Thereby, the inside of the centrifugal cancel chamber 64 is maintained in a state filled with the fluid medium.

Next, when the input shaft 14 is rotating and hydraulic oil is not supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement hydraulic chamber 58 of the third clutch 22 is also rotated together with the input shaft 14. Therefore, a centrifugal pressure is generated in the hydraulic oil in the fastening hydraulic chamber 58, and the fastening piston 56 is pressed in the fastening direction (in the right direction in FIG. 12) to press the friction plate 52 and the friction counterpart plate 54 by this centrifugal pressure. The
On the other hand, since the centrifugal cancel chamber 64 also rotates together with the input shaft 14, a centrifugal pressure is generated in the fluid medium in the centrifugal cancel chamber 64, and this centrifugal pressure is released from the fastening piston 56 (leftward in FIG. 12). ) To cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58.
As described above, the inside of the centrifugal cancel chamber 64 is maintained in a state filled with the fluid medium pushed into the centrifugal cancel chamber 64 from the volume change allowing portion 68. Accordingly, a centrifugal pressure sufficient to cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58 acts on the fastening piston 56 from the centrifugal cancel chamber 64.
As a result, the engagement piston 56 of the third clutch 22 is reliably pressed in the releasing direction (leftward in FIG. 12) by the return spring 66 as shown in FIG. 12, and the friction plate 52 and the friction counterpart plate 54 do not contact each other. Maintained in the released state.

Next, when the input shaft 14 is rotating and hydraulic fluid is supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement hydraulic chamber 58 of the third clutch 22 is also rotating together with the input shaft 14. Therefore, a centrifugal pressure is generated in the hydraulic oil in the fastening hydraulic chamber 58, and by this centrifugal pressure, the fastening piston 56 is pressed in the fastening direction (rightward in FIG. 13) that presses the friction plate 52 and the friction counterpart plate 54 together. . However, since the centrifugal cancel chamber 64 also rotates together with the input shaft 14, a centrifugal pressure is generated in the fluid medium in the centrifugal cancel chamber 64, and this centrifugal pressure is released from the fastening piston 56 (leftward in FIG. 13). ) To cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58. As a result, as shown in FIG. 13, the engagement piston 56 of the third clutch 22 moves in the engagement direction (rightward in FIG. 13) by the hydraulic pressure of the hydraulic oil supplied from the valve body to the engagement hydraulic chamber 58, causing friction. The plate 52 and the friction mating plate 54 are maintained in the fastened state in contact with each other. That is, the engagement state of the third clutch 22 is appropriately controlled according to the hydraulic control by the valve body.
Moreover, when the fastening piston 56 of the third clutch 22 moves in the fastening direction, the distance between the fastening piston 56 and the seal plate 62 is reduced, and the volume of the centrifugal cancel chamber 64 is reduced accordingly. Along with this, the piston 76 in the volume change allowing portion 68 moves away from the centrifugal cancel chamber 64 against the elastic force of the spring 78 (rightward in FIG. 13), and the fluid pushed out of the centrifugal cancel chamber 64 The medium is accommodated in the volume change allowing portion 68. Therefore, even when the volume of the centrifugal cancel chamber 64 is reduced by moving the fastening piston 56 in the fastening direction as shown in FIG. 13, the movement of the fastening piston 56 is prevented by the fluid medium in the centrifugal cancel chamber 64. Absent.

  As described above, according to the third embodiment, the volume change allowing portion 68 is a projecting portion in fluid communication with the centrifugal cancel chamber 64, and the piston in the volume change allowing portion 68 is moved according to the movement of the fastening piston 56. As a result of the movement of 76, a part of the hydraulic oil in the centrifugal cancel chamber 64 is accumulated, or the hydraulic oil accumulated in the volume change allowing portion 68 is returned to the centrifugal cancel chamber 64. Even if the volume in the centrifugal cancel chamber 64 changes accordingly, the inside of the centrifugal cancel chamber 64 can always be maintained in a state filled with the fluid medium, and the centrifugal pressure by the hydraulic oil in the fastening hydraulic chamber 58 can be reduced. Sufficient centrifugal pressure can be applied to the fastening piston 56 to cancel. Therefore, the same effect as the second embodiment described above can be obtained.

  Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment, the configuration of the volume change allowing portion 68 in the first embodiment described above is different, and the other configurations are the same. Therefore, only the different points will be described here. FIG. 14 is a partially enlarged cross-sectional view showing the third clutch 22 in the released state when the input shaft 14 is stopped, and FIG. 15 is a diagram showing the third clutch 22 in the opened state when the input shaft 14 is rotating. FIG. 16 is a partially enlarged sectional view showing the third clutch 22, and FIG. 16 is a partially enlarged sectional view showing the third clutch 22 in the engaged state when the input shaft 14 is rotating.

  According to the fourth embodiment, as shown in FIGS. 14 to 16, the volume change allowing portion 68 is formed so as to protrude to the opposite side of the centrifugal cancel chamber 64 along the axial direction of the input shaft 14. A cylindrical side wall 70 and an end surface 72 covering the tip of the side wall 70 are provided, and an opening 62c is formed in the seal plate 62 so that the inside of the volume change allowing portion 68 is in fluid communication with the centrifugal cancel chamber 64. Is formed. The side wall portion 70 of the volume change allowing portion 68 is formed of a rigid body that does not deform, and the length and inner diameter in the longitudinal direction are based on the amount of change in the volume in the centrifugal cancel chamber 64 as the fastening piston 56 moves. Is set. More specifically, the volume of the volume change allowing portion 68 is set to be equal to or larger than the change amount of the volume in the centrifugal cancel chamber 64.

  Further, a film member 80 (diaphragm) having elasticity is provided so as to close the opening 62c formed in the seal plate 62. The membrane member 80 bulges to the centrifugal cancel chamber 64 side or bulges to the volume change allowance portion 68 side, and the volume in the volume change allowance portion 68 fluctuates. The volume change in the centrifugal cancel chamber 64 that is in communication is allowed.

Next, the operation of the centrifugal cancel structure 46 according to the above-described fourth embodiment of the present invention will be described.
First, when the input shaft 14 is stopped and the hydraulic oil is not supplied to the engagement hydraulic chamber 58 of the third clutch 22, as shown in FIG. The elastic force of the return spring 66 moves in the release direction (leftward in FIG. 14), and the friction plate 52 and the friction counterpart plate 54 are maintained in a non-contact release state.

  At this time, the volume of the centrifugal cancel chamber 64 increases as the distance between the fastening piston 56 and the seal plate 62 increases. Along with this, the membrane member 80 of the volume change allowing portion 68 expands toward the centrifugal cancel chamber 64 and pushes the fluid medium stored in the volume change allowing portion 68 into the centrifugal cancel chamber 64. Thereby, the inside of the centrifugal cancel chamber 64 is maintained in a state filled with the fluid medium.

Next, when the input shaft 14 is rotating and hydraulic oil is not supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement hydraulic chamber 58 of the third clutch 22 is also rotated together with the input shaft 14. Therefore, a centrifugal pressure is generated in the hydraulic oil in the fastening hydraulic chamber 58, and the fastening piston 56 is pressed in the fastening direction (in the right direction in FIG. 15) to press the friction plate 52 and the friction counterpart plate 54 by this centrifugal pressure. The
On the other hand, since the centrifugal cancel chamber 64 also rotates together with the input shaft 14, a centrifugal pressure is generated in the fluid medium in the centrifugal cancel chamber 64, and this centrifugal pressure is released from the fastening piston 56 (leftward in FIG. 15). ) To cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58.
As described above, the inside of the centrifugal cancel chamber 64 is maintained in a state filled with the fluid medium pushed into the centrifugal cancel chamber 64 from the volume change allowing portion 68. Accordingly, a centrifugal pressure sufficient to cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58 acts on the fastening piston 56 from the centrifugal cancel chamber 64.
As a result, the engagement piston 56 of the third clutch 22 is reliably pressed in the release direction (leftward in FIG. 15) by the return spring 66 as shown in FIG. 15, and the friction plate 52 and the friction counterpart plate 54 do not contact each other. Maintained in the released state.

Next, when the input shaft 14 is rotating and hydraulic fluid is supplied to the engagement hydraulic chamber 58 of the third clutch 22, the engagement hydraulic chamber 58 of the third clutch 22 is also rotating together with the input shaft 14. Therefore, a centrifugal pressure is generated in the hydraulic oil in the fastening hydraulic chamber 58, and by this centrifugal pressure, the fastening piston 56 is pressed in the fastening direction (rightward in FIG. 16) that presses the friction plate 52 and the friction counterpart plate 54 together. . However, since the centrifugal cancel chamber 64 also rotates together with the input shaft 14, a centrifugal pressure is generated in the fluid medium in the centrifugal cancel chamber 64, and this centrifugal pressure is released from the fastening piston 56 (leftward in FIG. 16). ) To cancel the centrifugal pressure due to the hydraulic oil in the fastening hydraulic chamber 58. As a result, as shown in FIG. 16, the engagement piston 56 of the third clutch 22 moves in the engagement direction (rightward in FIG. 16) by the hydraulic pressure of the hydraulic oil supplied from the valve body to the engagement hydraulic chamber 58, and the friction is generated. The plate 52 and the friction mating plate 54 are maintained in the fastened state in contact with each other. That is, the engagement state of the third clutch 22 is appropriately controlled according to the hydraulic control by the valve body.
Moreover, when the fastening piston 56 of the third clutch 22 moves in the fastening direction, the distance between the fastening piston 56 and the seal plate 62 is reduced, and the volume of the centrifugal cancel chamber 64 is reduced accordingly. Along with this, the membrane member 80 of the volume change allowing portion 68 expands toward the volume change allowing portion 68, and the fluid medium pushed out from the centrifugal cancel chamber 64 is accommodated inside the volume change allowing portion 68. Therefore, even when the volume of the centrifugal cancel chamber 64 is reduced by moving the fastening piston 56 in the fastening direction as shown in FIG. 16, the movement of the fastening piston 56 is prevented by the fluid medium in the centrifugal cancel chamber 64. Absent.

  Thus, according to the fourth embodiment, the membrane member 80 provided between the centrifugal cancel chamber 64 and the volume change allowing portion 68 bulges toward the centrifugal cancel chamber 64 or the volume change allowing portion 68 side. Since the volume in the volume change allowance portion 68 fluctuates and the volume change in the centrifugal cancel chamber 64 that is in fluid communication with the volume change allowance portion 68 is allowed. Even if the volume in the centrifugal cancel chamber 64 changes according to the movement of the piston 56, the inside of the centrifugal cancel chamber 64 can always be maintained in a state filled with the fluid medium, and the hydraulic oil in the fastening hydraulic chamber 58 can be maintained. A sufficient centrifugal pressure can be applied to the fastening piston 56 to cancel out the centrifugal pressure due to. Therefore, the same effect as the first embodiment described above can be obtained.

DESCRIPTION OF SYMBOLS 1 Powertrain structure 2 Engine 8 Automatic transmission 14 Input shaft 16 Transmission mechanism 18 1st clutch 20 2nd clutch 22 3rd clutch 46 Centrifugal cancellation structure 56 Fastening piston 56c Pressure-receiving surface 58 Fastening hydraulic chamber 64 Centrifugal cancellation chamber 66 Return spring 68 Volume change allowance (elastic deformation, protrusion)
70 Side Wall 72 End Face 74 Compressible Fluid 76 Piston 78 Spring 80 Membrane Member

Claims (3)

A centrifugal cancel structure of a power transmission clutch for an automatic transmission,
An input shaft to which power generated by a power source is input;
A speed change mechanism disposed around the input shaft;
A power transmission clutch that transmits power to the speed change mechanism, and includes a fastening hydraulic chamber to which hydraulic oil is supplied, a fastening piston having a pressure receiving surface for hydraulic pressure by the hydraulic oil, and a direction in which the input shaft extends. The power transmission clutch having a centrifugal cancellation chamber provided on the opposite side of the fastening hydraulic chamber with respect to the fastening piston and enclosing a fluid medium therein,
For the automatic transmission, the centrifugal cancel chamber is provided with a volume change allowing portion for allowing a volume change in the centrifugal cancel chamber in accordance with the movement of the fastening piston that receives the hydraulic pressure of the fastening hydraulic chamber. Centrifugal canceling structure for power transmission clutch. The volume change allowing portion is a protruding portion fluidly connected to the centrifugal cancel chamber,
When the fastening piston moves in the fastening direction, the protruding portion of the centrifugal cancellation chamber accumulates a part of the hydraulic oil in the centrifugal cancellation chamber, and when the fastening piston moves in the direction opposite to the fastening direction. 2. The centrifugal cancel structure for a power transmission clutch for an automatic transmission according to claim 1, wherein the hydraulic oil accumulated in the protrusion is returned to the centrifugal cancel chamber. The volume change allowing portion is an elastic deformation portion that allows a volume change in the centrifugal cancel chamber accompanying the movement of the fastening piston by elastic deformation,
The automatic transmission according to claim 1 or 2, wherein the elastically deforming portion of the centrifugal cancel chamber is configured to expand and contract in the same direction as the direction in which the input shaft extends to allow a volume change in the centrifugal cancel chamber. Centrifugal cancellation structure for power transmission clutch.

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