JP2016011746A - Wet type clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wet type clutch capable of reducing a hydraulic pressure necessary for an oil chamber in an engagement state.SOLUTION: When a hydraulic pressure is supplied to an oil chamber 16 from an oil supply passage 17, by the hydraulic pressure, a clutch piston 10 moves to a clutch plate 7 side, and a press part 13 of the clutch piston 10 presses the clutch plate 7. By the pressing force, the clutch plate 7 and a clutch disc 9 come into a press-contact, a wet type clutch 1 comes into an engagement state, and the rotation of an input axis 2 is transmitted to a clutch hub 4. After the engagement of the wet type clutch 1, according to the rotation of a clutch drum 3, the amount of a hydraulic oil in a space 25 decreases, and the volume in a canceller chamber, which is a portion filled with the hydraulic oil in the space 25, decreases.

Description

  The present invention relates to a wet clutch.

  For example, automatic clutches and continuously variable transmissions for vehicles use wet clutches that operate by hydraulic pressure.

  FIG. 3 is a cross-sectional view showing a configuration of a conventional wet clutch.

  In the wet clutch 101, a plurality of clutch plates 105 and clutch disks 106 are interposed between a clutch drum 103 fixed to the rotary shaft 102, and a clutch hub 104 fixed to the rotary shaft 102 and another rotary shaft (not shown). Are arranged alternately. Each clutch plate 105 is supported by a clutch drum 103, and each clutch disk 106 is supported by a clutch hub 104. A clutch piston 107 is disposed inside the clutch drum 103 so as to be movable in the axial direction, and an oil chamber 108 is formed between the clutch drum 103 and the clutch piston 107. A centrifugal hydraulic canceller 109 is disposed on the opposite side of the oil chamber 108 across the clutch piston 107, and a canceller chamber 110 filled with hydraulic oil is provided between the clutch piston 107 and the centrifugal hydraulic canceller 109. Is formed. A return spring 111 is interposed between the clutch piston 107 and the centrifugal hydraulic canceller 109 to urge them in a direction away from each other.

  When hydraulic pressure is supplied into the oil chamber 108, the clutch piston 107 moves toward the clutch plate 105, and the clutch piston 107 presses the clutch plate 105. By this pressing, the clutch plate 105 and the clutch disc 106 are pressed against each other, and the wet clutch 101 is engaged. When the hydraulic oil in the oil chamber 108 is removed from this engaged state (when the hydraulic pressure is released), the clutch piston 107 moves to the clutch drum 103 side by the urging force of the return spring 111, and the clutch by the clutch piston 107 is moved. The pressing of the plate 105 is released. As a result, the pressure contact between the clutch plate 105 and the clutch disk 106 is released, and the wet clutch 101 is released.

  When the rotating shaft 102 rotates, the clutch drum 103 and the clutch piston 107 rotate, so that centrifugal force acts on the hydraulic oil in the oil chamber 108. Therefore, centrifugal oil pressure is generated in the oil chamber 108, and the clutch piston 107 is biased toward the clutch plate 105 by this centrifugal oil pressure. Since the canceller chamber 110 is formed on the opposite side of the oil chamber 108 across the clutch piston 107, centrifugal oil pressure is also generated in the canceller chamber 110 when the rotating shaft 102 rotates. The centrifugal hydraulic pressure in the oil chamber 108 can be canceled (cancelled) by the centrifugal hydraulic pressure in the canceller chamber 110. Therefore, the wet clutch 101 can prevent the centrifugal hydraulic pressure in the oil chamber 108 from hindering the movement of the clutch piston 107 when the wet clutch 101 is released. Further, seizure of the clutch plate 105 and the clutch disk 106 due to the clutch piston 107 moving and pushing the clutch plate 105 only by rotation (centrifugal hydraulic pressure) can be prevented.

JP 2013-130249 A

  However, when the wet clutch 101 is engaged, the clutch piston 107 is pressed against the clutch plate 105 against the urging force of the return spring 111 and the centrifugal oil pressure generated in the canceller chamber 110 as the oil pressure in the oil chamber 108. High hydraulic pressure that can be needed. The oil pressure supplied into the oil chamber 108 is generated by an oil pump driven by the power of the engine of the vehicle. Therefore, the high oil pressure required in the engaged state contributes to the deterioration of the fuel consumption of the vehicle. Yes.

  The objective of this invention is providing the wet clutch which can reduce the hydraulic pressure required for an oil chamber in an engagement state.

  In order to achieve the above object, a wet clutch according to the present invention is a wet clutch that is engaged / released by hydraulic pressure, and is disposed in a clutch drum that rotates integrally with a rotating body. A clutch piston provided to be movable in the rotation center line direction of the drum, and an oil chamber that is formed on one side of the rotation center line direction with respect to the clutch piston and is supplied with hydraulic pressure for moving the clutch piston for engagement And a centrifugal hydraulic canceller that is disposed on the other side of the rotation center line direction with respect to the clutch piston and forms a canceller chamber filled with hydraulic oil with the clutch piston, and a reduction that reduces the volume of the canceller chamber after engagement. Mechanism.

  According to this configuration, when hydraulic pressure is supplied to the oil chamber, the clutch piston moves to the other side in the rotation center line direction, and the wet clutch is engaged. After this engagement, the volume of the canceller chamber filled with hydraulic oil is reduced by the action of the reduction mechanism, and accordingly, the centrifugal hydraulic pressure generated in the canceller chamber (the centrifugal hydraulic pressure acting on the clutch piston from the canceller chamber side) is reduced. To do. Therefore, the hydraulic pressure required for the oil chamber can be reduced in the engaged state. As a result, the output of an oil pump that supplies hydraulic pressure to the oil chamber can be reduced, and the fuel efficiency of a vehicle equipped with a wet clutch can be improved.

  The reduction mechanism is provided between the clutch piston and the centrifugal hydraulic canceller, and is pressed against the clutch piston and the centrifugal oil chamber canceller in an engaged state to divide the space between the clutch piston and the centrifugal hydraulic canceller. A configuration including a seal, a space on the outer side in the radial direction with respect to the seal, and a communication path communicating with the space opposite to the clutch piston side with respect to the centrifugal hydraulic canceller may be employed.

  According to this configuration, in the engaged state, the annular seal is pressed against the clutch piston and the centrifugal oil chamber canceller, and the space between the clutch piston and the centrifugal hydraulic canceller is the outer space in the rotational radial direction with the seal as a boundary. And the inner space. The space outside the rotational radial direction with respect to the seal communicates with the space on the opposite side to the clutch piston side with respect to the centrifugal hydraulic canceller by the communication path. Therefore, in the engaged state, the hydraulic oil is discharged through the communication path from the outer space in the rotational radial direction with respect to the seal, and the space is no longer a canceller chamber filled with the hydraulic oil. As a result, in the engaged state, the volume of the canceller chamber filled with hydraulic oil can be gradually reduced, and the centrifugal hydraulic pressure generated in the canceller chamber can be reduced.

  According to the present invention, the hydraulic pressure required for the oil chamber can be reduced in the engaged state. As a result, the output of an oil pump that supplies hydraulic pressure to the oil chamber can be reduced, and the fuel efficiency of a vehicle equipped with a wet clutch can be improved.

It is sectional drawing which cut | disconnected the wet clutch which concerns on one Embodiment of this invention by the plane containing a rotation centerline, and shows the releasing state of a wet clutch. It is sectional drawing which cut | disconnected the wet clutch shown by FIG. 1 by the plane containing a rotation centerline, and shows the engagement state of a wet clutch. It is sectional drawing which cut | disconnected the conventional wet clutch by the plane containing a rotation centerline.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  1 and 2 are cross-sectional views of the wet clutch 1 according to one embodiment of the present invention cut along a plane including the rotation center line C. FIG. 1 and 2 show only one side of the wet clutch 1 with respect to the rotation center line C.

  The wet clutch 1 is incorporated in, for example, an automatic transmission or a continuously variable transmission, and rotates the input shaft 2 that is a rotating body to which driving force is input, so that the input shaft 2 and the rotation center line C are shared. Used to transmit / cut off a rotating body (not shown).

  The wet clutch 1 includes a clutch drum 3 fixed to the input shaft 2 and a clutch hub 4 fixed to another rotating body.

  The clutch drum 3 has a direction substantially perpendicular to the rotation center line C, that is, a substantially disk-shaped disk portion 5 extending in the rotation radial direction, and a direction parallel to the rotation center line C on the outer peripheral side of the disk portion 5, that is, A cylindrical portion 6 having a substantially cylindrical shape extending in the rotation center line direction is integrally provided. A plurality of annular clutch plates 7 are arranged at intervals inside the cylindrical portion 6, and the outer peripheral portion of each clutch plate 7 is spline-fitted to the cylindrical portion 6.

  The clutch hub 4 has a facing portion 8 that faces the cylindrical portion 6 of the clutch drum 3 in the rotational radial direction. Between the cylindrical portion 6 and the facing portion 8, a plurality of annular clutch disks 9 are arranged alternately with the clutch plate 7 in the rotation center line direction. The inner peripheral part of this is spline-fitted.

  A clutch piston 10 is provided inside the clutch drum 3 and at a position closer to the disc portion 5 side of the clutch drum 3 than the clutch plate 7 so as to be movable in the direction of the rotation center line. The clutch piston 10 includes a substantially disc-shaped disc portion 11 extending in the rotational radial direction, a substantially cylindrical outer peripheral cylindrical portion 12 extending from the outer peripheral end of the disc portion 11 toward the clutch plate 7 in the rotational center line direction, It integrally has a flange-shaped pressing portion 13 extending outward in the rotational radial direction from the end of the outer peripheral cylindrical portion 12 on the clutch plate 7 side. The pressing portion 13 faces the clutch plate 7 in the rotation center line direction.

  An inner peripheral portion of the disc portion 11 is bent and extended toward the clutch plate 7 side, and is bent and extended toward the input shaft 2 side. An end portion of the disc portion 11 extends between the disc portion 11 and the input shaft 2. An annular seal 14 for sealing is provided. Further, an annular seal 15 is provided on the outer periphery of the outer cylinder portion 12 to seal between the outer cylinder portion 12 and the clutch drum 3. Regardless of the position of the clutch piston 10, the seals 14 and 15 are always in contact with the input shaft 2 and the clutch drum 3, respectively. Thus, an oil chamber 16 closed by the input shaft 2, the clutch drum 3, the clutch piston 10 and the seals 14, 15 is formed between the clutch drum 3 and the clutch piston 10. The oil chamber 16 communicates with an oil passage 17 formed in the input shaft 2, and hydraulic pressure is supplied / released to the oil chamber 16 through the oil passage 17.

  A centrifugal hydraulic canceller 18 is disposed on the opposite side of the oil chamber 16 with the clutch piston 10 interposed therebetween. The centrifugal hydraulic canceller 18 has a substantially disc-shaped spring receiving portion 19 extending in the rotational radial direction, and extends from the outer peripheral end of the spring receiving portion 19 toward the disc portion 11 of the clutch piston 10. And an outer peripheral portion 21 that is bent outwardly and extends toward the outer peripheral cylindrical portion 12 of the clutch piston 10.

  A return spring 22 is interposed between the clutch piston 10 and the centrifugal hydraulic canceller 18. Due to the urging force of the return spring 22, the clutch piston 10 and the centrifugal hydraulic canceller 18 are elastically urged in a direction away from each other. By this urging, the centrifugal hydraulic canceller 18 abuts on the snap ring 23 attached to the input shaft 2 and the movement in the rotation center line direction is restricted.

  An annular seal 24 that seals between the outer peripheral portion 21 and the outer peripheral cylindrical portion 12 of the clutch piston 100 is provided on the outer periphery of the outer peripheral portion 21 of the centrifugal hydraulic canceller 18. Thereby, a space 25 closed by the clutch piston 10, the centrifugal hydraulic canceller 18 and the seal 24 is formed between the clutch piston 10 and the centrifugal hydraulic canceller 18. The space 25 communicates with an oil passage 26 formed in the input shaft 2, and hydraulic oil is supplied to the space 25 through the oil passage 26. When the space 25 is filled with hydraulic oil, the space 25 filled with the hydraulic oil becomes a canceller chamber.

  An annular seal 27 is provided at the bent portion 20 of the centrifugal hydraulic canceller 18. An oil discharge hole 28 having a minute cross-sectional area is formed in the outer peripheral end portion of the outer peripheral portion 21 of the centrifugal hydraulic canceller 18 so as to penetrate the outer peripheral portion 21 in the thickness direction.

  When the oil pressure in the oil chamber 16 is released, the clutch piston 10 is positioned closest to the disc portion 5 of the clutch drum 3 as shown in FIG. At this time, the clutch plate 7 and the clutch disk 9 are not in pressure contact, the wet clutch 1 is in the released state, and transmission of rotation between the input shaft 2 and the rotating body to which the clutch hub 4 is fixed is cut off. Is done. Further, the seal 27 provided at the bent portion 20 of the centrifugal hydraulic canceller 18 is separated from the disc portion 11 of the clutch piston 10. A space 25 between the clutch piston 10 and the centrifugal hydraulic canceller 18 is filled with hydraulic oil supplied through the oil passage 26, and the entire space 25 is a canceller chamber.

  The hydraulic oil in the space 25 is discharged to the outside through the oil discharge hole 28, but the cross-sectional area of the oil discharge hole 28 is very small, and the flow rate of the hydraulic oil discharged from the oil discharge hole 28 is the oil flow path. Since the flow rate of the hydraulic oil supplied from 26 is extremely small, the state where the entire space 25 is filled with the hydraulic oil is maintained.

  When hydraulic pressure is supplied from the oil flow path 17 to the oil chamber 16, the hydraulic pressure causes the clutch piston 10 to move toward the clutch plate 7, and the pressing portion 13 of the clutch piston 10 is moved to the clutch plate as shown in FIG. 7 is pressed. By this pressing, the clutch plate 7 and the clutch disk 9 are pressed against each other, the wet clutch 1 is engaged, and the rotation of the input shaft 2 is transmitted to the clutch hub 4. In this engaged state, the seal 27 provided on the bent portion 20 of the centrifugal hydraulic canceller 18 comes into liquid-tight contact (pressure contact) with the disc portion 11 of the clutch piston 10. As a result, the space 25 between the clutch piston 10 and the centrifugal hydraulic canceller 18 is divided (divided) into an outer space 25A and an inner space 25B in the rotational radial direction with the seal 27 as a boundary.

  In a state where the clutch drum 3 rotates integrally with the input shaft 2, centrifugal force acts on the hydraulic oil in the spaces 25A and 25B. Since the seal 27 is in liquid-tight contact with the disc part 11 of the clutch piston 10, centrifugal force acts on the hydraulic oil in the space 25B inside the seal 27, and centrifugal hydraulic pressure is generated in the space 25B. However, hydraulic fluid does not flow from the space 25B into the space 25A outside the seal 27. Accordingly, the space 25B is filled with hydraulic oil. On the other hand, when centrifugal force acts on the hydraulic oil in the space 25 </ b> A, the hydraulic oil is gradually discharged to the outside through the oil discharge hole 28. Therefore, after the engagement of the wet clutch 1, the amount of hydraulic oil in the space 25 </ b> A gradually decreases as the clutch drum 3 rotates, and the portion filled with the hydraulic oil in the space 25 </ b> A gradually decreases. Since the portion not filled with the hydraulic oil in the space 25 </ b> A is not a canceller chamber for generating centrifugal oil pressure, the volume of the canceller chamber gradually decreases as the clutch drum 3 rotates. When the volume of the canceller chamber filled with hydraulic oil is gradually reduced, the centrifugal hydraulic pressure generated in the canceller chamber (the centrifugal hydraulic pressure applied to the clutch piston 10 from the canceller chamber side) is gradually reduced accordingly. Therefore, the hydraulic pressure required for the oil chamber 16 in the engaged state can be reduced. As a result, the output of the oil pump that supplies hydraulic pressure to the oil chamber 16 can be reduced, and the fuel efficiency of the vehicle on which the wet clutch 1 is mounted can be improved.

  When the hydraulic pressure in the oil chamber 16 is released from the engaged state, the clutch piston 10 moves to the clutch drum 3 side by the urging force of the return spring 22. When the clutch piston 10 moves slightly and the liquid-tight contact between the seal 27 and the disc portion 11 of the clutch piston 10 is released, hydraulic oil flows from the space 25B into the space 25A, and the space 25A is activated. Filled with oil. Thereby, the space 25A returns to the canceller chamber, and centrifugal hydraulic pressure is generated again in the space 25A. As a result, since the centrifugal hydraulic pressure generated in the canceller chamber increases, the centrifugal hydraulic pressure in the oil chamber 16 can be canceled (cancelled) by this centrifugal hydraulic pressure. Therefore, it is possible to prevent the centrifugal oil pressure in the oil chamber 16 from obstructing the movement of the clutch piston 10 when the wet clutch 1 is released.

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, the number of oil discharge holes 28 may be one or plural.

  Further, by omitting the oil discharge hole 28 and adjusting the sealing performance (pressure contact force) of the seal 24 provided on the outer periphery of the outer peripheral portion 21 of the centrifugal hydraulic canceller 18, the outer peripheral portion 21 and the outer peripheral cylindrical portion of the clutch piston 100 are adjusted. The hydraulic oil may be discharged at a minute flow rate from between the two.

  In the above-described embodiment, the configuration in which the volume of the canceller chamber gradually decreases after the wet clutch 1 is engaged has been described. .

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1 Wet clutch 3 Clutch drum 10 Clutch piston 18 Centrifugal hydraulic canceller 25 Space (canceller room)
25A space (canceller room)
25B space (canceller room)
27 Seal C Rotation center line

Claims (2)

A wet clutch engaged / released by hydraulic pressure,
A clutch drum that rotates integrally with the rotating body;
A clutch piston disposed in the clutch drum and provided so as to be movable in a rotation center line direction of the clutch drum;
An oil chamber that is formed on one side of the rotation center line direction with respect to the clutch piston and is supplied with hydraulic pressure that moves the clutch piston for engagement;
A centrifugal hydraulic canceller that is disposed on the other side of the rotation center line direction with respect to the clutch piston and forms a canceller chamber filled with hydraulic fluid with the clutch piston;
And a reduction mechanism for reducing the volume of the canceller chamber after engagement. The reduction mechanism is:
The space between the clutch piston and the centrifugal hydraulic canceller is provided between the clutch piston and the centrifugal hydraulic canceller and is pressed against the clutch piston and the centrifugal oil chamber canceller in an engaged state. An annular seal,
2. The wet clutch according to claim 1, comprising a space on the outer side in the rotational radial direction with respect to the seal and a communication passage communicating with the space opposite to the clutch piston side with respect to the centrifugal hydraulic canceller.

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