JPH05164143A - Hydraulic clutch - Google Patents

Abstract

PURPOSE:To prevent a clutch from being rotated under the influence of agitation oil due to the rotation of a clutch cover at the time when the clutch is disengaged, regardless of the oil temperature in a clutch chamber. CONSTITUTION:A clutch disc 17 in a clutch chamber 16 is spline-fitted in an input shaft 23 through a hub 26, a piston 28 is inserted into a recessed groove 4b of a rear cover 14, and a valve 29 for connecting or disconnecting a hole 14c from the back face of the piston is inserted into a recessed part 28a. A hydraulic mechanism for circulating oil in the clutch chamber drives the piston, and a shape memory coil spring 37 between the piston and the valve decreases the total length of the piston including the valve at the time when the oil temperature is less than a specified value to lock an abutting plate 39 to the piston. A bias spring 41 between the input shaft and the hub separates the disc from a front cover 13 by a specified distance (s), and a shape memory spring 42 of the hub deforms the shape memory spring at the time when the oil temperature is less than the specified value to separate the disc from the front cover more and more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic clutch for connecting / disconnecting a torque of a crankshaft of an engine to a transmission.

[0002]

2. Description of the Related Art As a hydraulic clutch of this type, a clutch disc is provided in a clutch cover fixed to the rear end of a crankshaft, and a piston is pressed against the clutch cover by a piston via a hydraulic mechanism. What has been done is known. As shown in FIG. 5, the hydraulic clutch includes a front cover 1a having a clutch cover 1 fixed to a rear end of a crankshaft 2 via a flex plate 3, a rear cover 1b joined to the cover, both covers 1a, A ring-shaped receiving plate 4 that has a clutch chamber 1c formed between 1b and is splined to the inner peripheral surface of the rear cover 1b is closely attached to the inner surface of the front cover 1a. The clutch disc 6 is spline-fitted to the input shaft 5 of the transmission provided on the same axis as the crankshaft 2 via the hub 6a so as to be movable in the axial direction of the input shaft 5, and the clutch disc 6 of the rear cover 1b is provided.
An annular piston 7 that can press the clutch disc 6 against the plate 4 is housed in the groove 1d formed on the side surface facing the. Also, the clutch disc 6 of the piston 7
The contact plate 8 fixed to the surface opposed to is spline-inserted into the inner peripheral surface of the rear cover 1b.

The hydraulic mechanism 9 has a control valve 9a and an oil pump 9b provided at the rear of the rear cover 1b, and a port 9c of the control valve 9a communicates with the back surface of the piston 7 through an oil passage 9d. 9e is communicated with the clutch chamber 1c. The clutch chamber 1c is filled with oil, and the oil is supplied to the control valve 9a, the oil passage 9e, and the oil pump 9b.
It circulates back to the oil pump 9b through the clutch chamber 1c and an oil passage (not shown). When the clutch pedal is not depressed, that is, when the clutch is connected, oil having a pressure higher than that of the oil in the clutch chamber 1c is supplied to the back surface of the piston 7 via the oil passage 9d, and the piston 7 passes through the contact plate 8. Since the clutch disc 6 is pressed against the receiving plate 4 by means of the clutch disc 6, the rotational force of the crankshaft 2 is transmitted to the input shaft. When the clutch pedal is depressed, that is, when the clutch is disengaged, the control valve 9a is switched and the hydraulic pressure on the back surface of the piston 7 drops below the hydraulic pressure in the clutch chamber 1c.
The clutch disc 6 moves toward the rear cover 1b and the piston 7 is pushed into the recessed groove 1d. As a result, the contact plate 8 separates from the clutch disc 6, and the clutch disc 6 separates from the receiving plate 4, so that the crankshaft 2
Is no longer transmitted to the input shaft 5.

[0004]

However, in the above hydraulic clutch, the clutch disc may be in the state of being close to the receiving plate even though the clutch is disengaged, and the rotation of the front cover and the receiving plate causes the clutch chamber to move. There was a problem that the oil of No. 1 was stirred by its viscous resistance and dragged by the flow of this oil to rotate the clutch disc. Also, in cold regions, disengage the clutch,
Moreover, even if the clutch disc is located almost in the center of the distance between the receiving plate and the abutting plate, the oil temperature in the clutch chamber is low and the viscous resistance of the oil is large. There was a problem that it was dragged and rotated.

An object of the present invention is to provide a hydraulic clutch capable of reducing the rotation of the clutch disc dragged by oil agitation accompanying the rotation of the clutch cover when the clutch is disengaged, regardless of whether the oil temperature in the clutch chamber is high or low. To do.

[0006]

A configuration of the present invention for achieving the above object will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. The hydraulic clutch of the present invention includes a front cover 13 fixed to a rear end of a crankshaft 18 of an engine, a rear cover 14 joined to the cover, and both covers 1.
A clutch cover 12 having a clutch chamber 16 formed between Nos. 3 and 14 and an input shaft 23 provided on the same axis as the crankshaft 18 are spline-fitted via a hub 26 to be provided in the clutch chamber 16. The clutch disc 17 that is movable in the axial direction of the input shaft 23 and the ring-shaped groove 14b formed on the side surface of the rear cover 14 that faces the clutch disc 17 can be pressed against the front cover 13 by inserting the clutch disc 17 into the front cover 13. Ring-shaped piston 2
8 and a plurality of holes 14c formed in the bottom surface of the concave groove 14b and the back surface of the piston 28 to communicate or cut off each other.
The valve 29 inserted in the recess 28a formed on the back surface of the
The oil is circulated in the clutch chamber 16 and the piston 28
A shape memory coil spring 37 that is mounted between the hydraulic mechanism driving the piston 28 and the valve 29 and that urges the piston 28 including the valve 29 so as to reduce the total length when the oil temperature in the clutch chamber 16 falls below a predetermined value. And the piston 28
Of the contact plate 39 fixed to the surface facing the clutch disc 17 and splined on the inner peripheral surface of the clutch cover 12 and the clutch disc 17 mounted between the input shaft 23 and the hub 26 at a predetermined distance from the front cover 13. Bias spring 41 for urging to separate by t
And a shape memory spring 42 that is attached to the hub 26 and biases the bias spring 41 so as to further separate the clutch disc 17 from the front cover 13 when the oil temperature in the clutch chamber 16 falls below a predetermined value. It is a thing.

[0007]

When the oil temperature in the clutch chamber 16 is above a predetermined value, the shape memory coil spring 37 increases the total length of the piston 28 including the valve 29, and the shape memory spring 42 having a small spring constant almost biases the bias spring 41. do not do. When the clutch is disengaged in this state, the abutment plate 39 causes the front cover 1 to move due to the oil pressure in the clutch chamber 16.
The clutch disc 17 is stopped at a predetermined distance h which is relatively small from 3, and the clutch disc 17 is stopped at a position away from the front cover 13 by a predetermined distance t, that is, substantially at the center of the distance h. When the oil temperature in the clutch chamber 16 becomes lower than a predetermined value, the shape memory coil spring 37 reduces the total length of the piston 28 including the valve 29, and the shape memory spring 42 having a large spring constant moves the clutch disc 17 from the front cover 13 to the front cover 13. The bias spring 41 is biased in the separating direction. When the clutch is disengaged in this state, the contact plate 39 causes the front cover 13 to move due to the hydraulic pressure in the clutch chamber 16.
To a distance H larger than the predetermined distance h, and the clutch disk 17 is stopped at a position approximately in the center of the distance H.

[0008]

An embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 to 4, a hydraulic clutch 11 is provided at the rear end of the engine. Hydraulic clutch 11
Includes a clutch cover 12 and a clutch disc 17 provided in the clutch cover. The clutch cover 12 has a flex plate 19 at the rear end of the crankshaft 18.
It has a front cover 13 fixed through the cover, a rear cover 14 joined to this cover, and a clutch chamber 16 formed between both covers 13, 14. A ring gear 21 is fixed to the outer peripheral surface of the flex plate 19, and an inner spline 14a is formed on the inner peripheral surface of the rear cover 14. An outer spline 22a capable of meshing with the inner spline 14a is provided on the outer periphery of the ring-shaped receiving plate 22.
The receiving plate 22 is spline-inserted into the inner peripheral surface of the rear cover 14, and is closely attached to the inner surface of the front cover 13.

An input shaft 23 of the transmission located on the same axis as the crankshaft 18 is inserted into the clutch chamber 16, and the tip end of the input shaft 23 is held by the front cover 13 via a bearing 24. In addition, the external spline 2 is attached to the input shaft 23.
3a is formed, and a hub 26 having an inner spline 26a capable of meshing with the outer spline is spline-fitted to the input shaft 23 so as to be movable in the axial direction. The clutch disc 17 is attached to the hub 26 via a torsion rubber 27. A ring-shaped concave groove 14b is formed on the side surface of the rear cover 14 facing the clutch disk 17, and the clutch disk 17 is formed in the concave groove 14b.
A ring-shaped piston 28 which can be pressed against is inserted.
A plurality of holes 14c are formed on the bottom surface of the concave groove 14b, and three holes are formed at equal intervals in this example. Recesses 28a are formed on the back surface of the piston 28 at positions facing the three holes 14c, and valves 29 are inserted into the recesses. A seal rubber 29a is attached to the center of the bottom portion of the valve 29 so that the hole 14c and the recess 28a are communicated or blocked by the movement of the valve (FIGS. 1 and 3).

The hydraulic mechanism 31 has a control valve 32 and an oil pump 33 provided behind the rear cover 14. The port 32a of the control valve 32 communicates with the back surface of the piston 28 via the oil passage 34 and the hole 14c, and the port 32b of the control valve 32 has an oil passage 36.
Through the clutch chamber 16. Also clutch room 1
6 is filled with oil, and this oil is supplied to the control valve 32, the oil passage 36, the clutch chamber 16 by the oil pump 33.
And an oil passage (not shown) to return to the oil pump 33 for circulation. When the clutch pedal (not shown) is not depressed, oil having a pressure higher than that of the oil in the clutch chamber 16 is supplied to the rear surface of the piston 28 through the oil passage 34 and the hole 14c, and the clutch pedal is depressed. Then, the control valve 32 is switched and the piston 2
The oil pressure on the back surface of the clutch 8 is smaller than that of the clutch chamber 16 (FIG. 4).

A shape memory coil spring 37 is mounted between the piston 28 and the valve 29, and the spring 37 has a first coil spring 37a having a large free length when the oil temperature falls below a predetermined value.
And a second coil spring 37b having a small free length.
Here, the predetermined value of the oil temperature is 20 ° C. in this example. The first coil spring 37a is mounted at a position sandwiched by the inner peripheral surface of the piston 28 and the outer peripheral surface of the valve 29, and the second coil spring 37b is mounted between the inner bottom of the valve 29 and the bottom of the recess 28a. One end of the first coil spring 37a has a valve 2
9 is engaged with a flange 29b formed on the edge of the opening,
The other end is locked to a snap ring 38 attached to the edge of the recess 28a of the piston 28. Shape memory coil spring 37
Urges the piston 28 including the valve 29 to have a smaller total length when the oil temperature in the clutch chamber 16 becomes lower than a predetermined value. Further, an outer spline 39a capable of meshing with the inner spline 14a formed on the inner peripheral surface of the rear cover 14 is formed on the outer periphery of the ring-shaped contact plate 39,
The rear cover 14 is splined into the inner spline 14a and fixed to the surface of the piston 28 facing the clutch disc 17.

A bias spring 41 is attached between the inner ring of the bearing 24 holding the tip of the input shaft 23 and the hub 26. In this example, the spring 41 has a ring-shaped base portion 41a and six elastic portions 41b which are integrally formed on the base portion and are radially formed at equal intervals. Distance t
Energize so that it only separates. One end of the shape memory spring 42 is fixed to the hub 26 near the tip of the elastic portion 41b, and the other end of the shape memory spring 42 biases the bias spring 41 toward the center of the input shaft 23. The shape spring 42 has an oil temperature of 20 in the clutch chamber 16.
When the oil temperature is lower than 20 ° C., the spring constant becomes small, the bias spring 41 is hardly deformed, and when the oil temperature is lower than 20 ° C., the spring constant becomes large.
1 is deformed (FIGS. 1 and 2).

The operation of the hydraulic clutch thus configured will be described. When the oil temperature in the clutch chamber 16 is 20 ° C. or higher, the shape memory coil spring 37 increases the total length of the piston 28 including the valve 29, and the shape memory spring 42 having a small spring constant hardly biases the bias spring 41. When the clutch is disengaged from the connected state (FIG. 2) (FIG. 1), the control valve 32 is switched and the hydraulic pressure on the back surface of the piston 28 falls below the hydraulic pressure in the clutch chamber 16, so that the contact plate 39 is removed from the clutch disc 17. It moves in the direction of separating, and stops at a position separated from the receiving plate 22 that is in close contact with the front cover 13 by a predetermined distance h. At the same time, the clutch disc 17 is biased by the bias spring 41 and moves in a direction away from the receiving plate 22, and stops at a position moved by a predetermined distance t from the receiving plate 22, that is, at a substantially center of the interval h.
Although the distance t between the clutch disc 17 and the receiving plate 22 and the contact plate 39 is relatively small, the clutch chamber 16
Since the oil has a low viscous resistance, even if the receiving plate 22 and the contact plate 39 rotate, the oil is stirred only in a narrow range, and the clutch disc 17 is hardly dragged and rotated by the stirred oil.

When the oil temperature in the clutch chamber 16 becomes lower than 20 ° C., the shape memory coil spring 37 reduces the total length of the piston 28 including the valve 29, and the shape memory spring 4 becomes smaller.
2 biases the bias spring 41 in the direction of separating the clutch disc 17 from the receiving plate 22. When the clutch is disengaged (FIG. 3), the contact plate 39 stops at a position separated from the receiving plate 22 by a distance H larger than the predetermined distance h. At the same time, the clutch disc 17 moves in a direction away from the receiving plate 22 by the elastic force of the bias spring 41 urged by the shape memory spring 42, and moves by a distance T larger than the predetermined distance t, that is, the distance H is almost the same. Centrally located and stopped. Although the viscous resistance of the oil in the clutch chamber 16 increases, the clutch disc 17, the receiving plate 22, and the contact plate 39
Since the gap between and is large, even if the receiving plate 22 and the contact plate 39 rotate and the oil is agitated over a wide range, the clutch disc 17 is hardly dragged and rotated by the agitated oil.

It should be noted that the numerical values such as the temperatures mentioned in the embodiments are merely examples and are not limited to these numerical values.

[0016]

As described above, according to the present invention, the clutch disc provided in the clutch chamber of the clutch cover is spline-fitted to the input shaft via the hub, and the ring-shaped groove is formed in the ring-shaped groove of the rear cover. Insert the piston
A valve that connects or shuts off the hole at the bottom of the groove and the back of the piston is inserted into the recess of the piston, and a hydraulic mechanism that circulates oil in the clutch chamber drives the piston and the shape memory installed between the piston and the valve. When the oil temperature falls below a predetermined value, the coil spring urges the piston, including the valve, to shorten the total length, and the contact plate is fixed to the piston.
A bias spring between the input shaft and the hub urges the clutch disc away from the front cover by a predetermined distance, and the shape memory spring attached to the hub deforms the shape memory spring when the oil temperature falls below a predetermined value. Since the clutch disc is urged further away from the front cover, even if the clutch cover is disengaged even if the oil temperature in the clutch chamber changes, even if the front cover and contact plate rotate and the oil is agitated, the clutch The disc is separated from the front cover and contact plate by an appropriate distance. As a result, the clutch disc is hardly dragged by the agitated oil to rotate.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a portion A of FIG. 4 showing a state in which an oil temperature in a clutch chamber of a hydraulic clutch according to an embodiment of the present invention is a predetermined value or more and the clutch is disengaged.

FIG. 2 is a sectional view corresponding to FIG. 1, showing a state in which the oil temperature in the clutch chamber of the hydraulic clutch is lower than a predetermined value and the clutch is disengaged.

FIG. 3 is a cross-sectional view corresponding to FIG. 1, showing a state in which the oil temperature in the clutch chamber of the hydraulic clutch is equal to or higher than a predetermined value and the clutch is engaged.

FIG. 4 is a sectional view of a main part including the hydraulic clutch.

FIG. 5 is a sectional view corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

 11 hydraulic clutch 12 clutch cover 13 front cover 14 rear cover 14b concave groove 14c hole 16 clutch chamber 17 clutch disc 18 crankshaft 23 input shaft 26 hub 28 piston 28a recess 29 valve 31 hydraulic mechanism 37 shape memory coil spring 39 contact plate 41 bias Spring 42 Shape memory spring

Claims (1)

[Claims] 1. A clutch formed between a front cover (13) fixed to a rear end of a crankshaft (18) of an engine, a rear cover (14) joined to the cover, and the both covers (13, 14). A clutch cover (12) having a chamber (16) and an input shaft (2) provided on the same axis as the crankshaft (18).
3) a clutch disc (17) fitted in the clutch chamber (16) by spline fitting via a hub (26) and movable in the axial direction of the input shaft (23), and the rear cover (14) A ring-shaped piston (28) which is inserted into a ring-shaped groove (14b) formed on the side surface of the clutch disk (17) and which can press the clutch disk (17) against the front cover (13). And a plurality of holes (14c) formed in the bottom surface of the recessed groove (14b) and the back surface of the piston (28) to communicate or cut off the piston.
Valve inserted in the recess (28a) formed on the back of (28)
(29), the oil is circulated in the clutch chamber (16) and the piston
A hydraulic mechanism (31) for driving (28), and a piston including a valve (29) mounted between the piston (28) and the valve (29) when the oil temperature in the clutch chamber (16) falls below a predetermined value. A shape memory coil spring (37) for urging so as to reduce the total length of (28), and an inner circumference of the clutch cover (12) fixed to a surface of the piston (28) facing the clutch disc (17). The contact plate (39) splined into the surface and the clutch disc (17) mounted between the input shaft (23) and the hub (26) are separated from the front cover (13) by a predetermined distance (t). Bias spring (4
1) and when the oil temperature in the clutch chamber (16) attached to the hub (26) falls below the predetermined value, the bias spring (41)
And a shape memory spring (42) for urging the clutch disk (17) to be further separated from the front cover (13) by deforming the clutch.