JPH0433463Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an improvement of a hydraulic clutch device.

Prior Art An input shaft and an output shaft, a clutch case that rotates together with one of the input shaft and the output shaft,
a rotor that rotates together with the other of the input shaft and the output shaft; and a piston that is slidably fitted into a cylinder bore formed in the clutch case and connects the input shaft and the output shaft by pressing the rotor. A hydraulic clutch device is known which is equipped with a clutch case and in which cooling hydraulic oil is allowed to flow into the clutch case. This has the advantage that the portion that generates heat due to friction with the rotor is cooled by the hydraulic oil flowing into the clutch case.

However, in conventional hydraulic clutch devices of this type, the clutch case is a closed type, so the hydraulic fluid that flows into the clutch case flows out of the clutch case through the outflow oil path. The clutch case is constantly filled with hydraulic fluid. This has resulted in a disadvantage that the clutch drag torque increases due to the viscosity of the hydraulic oil.

On the other hand, as described in Japanese Patent Laid-Open No. 59-131035, for example, it is conceivable to create a release type clutch by forming a discharge port on the outer circumference of the clutch case to discharge the hydraulic oil to the outside.

However, if the clutch case is a release type as described above, centrifugal oil pressure is generated in the cylinder bore of the clutch case where the piston is fitted due to the rotation of the clutch case, and this centrifugal oil pressure acts in the direction in which the piston is pushed. Therefore, there arises a disadvantage that the disengagement characteristics of the clutch are deteriorated. Although it is possible to strengthen the biasing force of the return spring to return the piston, it is possible to increase the piston diameter to prevent an increase in the clutch size due to an increase in the size of the return spring and a related decrease in responsiveness. Alternatively, it may be necessary to increase the hydraulic pressure.

Means for Solving the Problems The present invention was developed against the background of the above circumstances, and its gist is to provide an input shaft, an output shaft, and a clutch that rotates together with one of the input shaft and output shaft. A case, a rotor that rotates together with the other of the input shaft and the output shaft, and a rotor that is slidably fitted into a cylinder bore formed in the clutch case and connects the input shaft and the output shaft by pressing the rotor. In a hydraulic clutch device of a type in which hydraulic oil for cooling is allowed to flow into the clutch case, the hydraulic clutch device is provided with a discharge port for discharging the hydraulic oil that has flowed into the clutch case to the outside. A sealing member is provided on the outer periphery of the clutch case, has a groove that opens toward the inner periphery to store a predetermined amount of hydraulic fluid, and is elastically deformed as the piston moves.

Function and Effect of the Invention With this structure, a discharge port for discharging the hydraulic oil that has flowed into the clutch case to the outside is provided on the outer circumference of the clutch case, while a groove that opens toward the inner circumference is provided. Since a seal member is provided in the clutch case and is elastically deformed with the movement of the piston, centrifugal hydraulic pressure is also generated in the hydraulic fluid stored in the seal member. Since this sealing member is arranged to be elastically deformed as the piston moves, the centrifugal hydraulic pressure generated in the stored hydraulic oil urges the piston in the counter-pressing direction, and this urging force causes the inside of the cylinder bore to be compressed. The biasing force generated by the centrifugal hydraulic pressure is canceled out. Therefore, it is not necessary to increase the piston diameter or increase the working oil pressure in order to prevent an increase in the clutch size due to an increase in the size of the return spring and a related decrease in response, and the piston's breaking characteristics can be reduced. will be resolved.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

In FIG. 1, power from a vehicle engine 10 is transmitted to drive wheels via a hydraulic multiple clutch device 12, a transmission (not shown), a differential gear device, etc. The above transmission is similar to that described in Japanese Patent Application No. 60-254353, for example.

The multiple clutch device 12 includes an input shaft 16 that is the crankshaft of the engine 10 and an output shaft 18 that is connected to the input shaft of a stepped transmission, and between the input shaft 16 and the output shaft 18, Between the input shaft 16 and the output shaft 18, a first clutch 22 for power transmission having two sets of frictional engagement devices, that is, a one-way clutch 20 that transmits power only in the direction from the engine 10 to the stepped transmission. A second clutch 24 for engine braking is provided in parallel.

A clutch case 26 that accommodates a first clutch 22, a second clutch 24, and the shaft end of the output shaft 18 is fixed to the input shaft 16. This clutch case 26 is composed of structural members 26a and 26b that are integrally connected to each other by bolts 27, and in this embodiment, together with a friction plate 40, a pressing plate 42, pistons 46, 50, etc., which will be described later, constitute a drive-side rotating body. are doing. The output shaft 18 and the clutch case 26 are provided to be rotatable relative to each other, and a second hub 32 that supports a second rotor 30 via a second damper 28 is spline-fitted to the output shaft 18 . Further, a first hub 34 is provided on the outer circumferential surface of the second hub 32 so as to be relatively rotatable via a one-way clutch 20, and a first rotor 38 is rotated by the first hub 34 via a first damper 36. Supported. An annular friction plate 40 is fixedly installed in the clutch case 26 and is located between the first rotor 38 and the second rotor 30.
A press plate 42 for pinching the plate 8 is provided so as to be movable in the axial direction. The above friction plate 4
The first rotor 38 and the second rotor 38 disposed on both sides of the
In this embodiment, the rotor 30 functions as a clutch plate for the first clutch 22 and the second clutch 24, and is provided with a friction material. Further, in this embodiment, the pressing plate 42 is moved to frictionally engage the driving side rotary body and the driven side rotary body with each other.

A cylinder bore 44 is formed on the inner circumferential surface of the output shaft 18 side portion of the clutch case 26, and the cylinder bore 44 receives hydraulic pressure supplied through an oil passage (not shown) formed in the transmission housing 45. an annular first piston 46 that moves in the axial direction by acting on the chamber 56;
are slidably fitted, and the pressing plate 42 is directly driven by the first piston 46. Similarly, clutch case 2
The cylinder bore 47 formed in the engine 10 side part in the engine 10 side communicates with another oil passage (not shown) formed in the transmission housing 45, and is supplied through an oil passage 48 formed in the output shaft 18. An annular second piston 50 that moves in the axial direction when hydraulic pressure is applied to the pressure chamber 58 is slidably fitted to the second piston 50.
and the friction platen 40.
is starting to be squeezed. In addition, 52 is a bearing, 53 is an oil seal, 54 is a first return spring that biases the first piston 46, and 5
5 is a second return spring that biases the second piston 50. In addition, the transmission housing 4
5 may be a clutch housing depending on the type of housing.

The first piston 46 has the cylinder bore 44
A control oil passage 62 is formed that connects the pressure chamber 56 formed therein and a discharge oil passage (not shown) formed in the transmission housing 45 and communicating with the drain. Further, although the control oil passage 62 is always closed, when the first piston 46 approaches a predetermined constant position with respect to the pressing plate 42, the first piston 46 An on-off valve 64 is provided that opens the control oil passage 62 in relation to its relative position with the pressing plate 42 . That is, a recessed hole, that is, a relatively shallow circular hole 66 is formed on the pressure receiving surface of the first piston 46, in other words, on the surface facing the pressure chamber 56.
A control oil passage 62 is opened at the bottom surface of the piston 6, and a through hole 68 passing through the first piston 46 is opened. A shaft portion 72 of a valve element 70 is fitted into the through hole 68 so as to be movable in the axial direction and in a fluid-tight manner. The valve element 70 includes a disk-shaped flange portion 74 that is loosely fitted into the circular hole 66. When the flange portion 74 closes the opening of the control oil passage 62, the shaft portion 72 is attached to the first piston 46. It is formed to protrude by a slight dimension C, for example, about 0.5 mm, from the input shaft 16 side end. Therefore, when the first piston 46 is brought close to the press plate 42, the shaft portion 72 that contacts the press plate 42
Since the valve element 70 is pushed back against the biasing force of the plate spring 76, the flange portion 74 is pushed back against the control oil passage 6.
Open the opening of 2 by about 0.5mm. Accordingly, in this embodiment, when the hydraulic pressure is supplied to the pressure chamber 56, the first piston 46 is positioned at the pressing start point.
Also, by closing the space between the control oil passage 62 and the drain, the first clutch 22 is brought into engagement.

An inflow oil passage 78 is formed in the transmission housing 45 to allow hydraulic oil to flow into the inner circumferential portion of the clutch case 26.
Discharge ports 80 and 82 are formed in the outer circumference of the clutch case 26 for discharging the hydraulic fluid flowing into the clutch case 26 to the outside. As a result, within the clutch case 26, the hydraulic oil flows from the inner circumferential portion to the outer circumferential portion, and the first rotor 3
8. The second rotor 30 is cooled. In the clutch case 26, a cross section U having an annular groove 84 opening toward the inner circumference is formed on the outer circumferential side between the friction plate 40 and the pressing plate 42.
An annular elastic member 86 is inserted therein, and the cross section U has an annular groove 88 similar to the above on the outer peripheral side between the friction plate 40 and the second piston 50.
A letter-shaped annular elastic member clutch 0 is inserted. These elastic members 86 and 90 are made of relatively thin rubber and are easily elastically deformed as the pressing plate 42 and the second piston 50 move, thereby operating the first clutch 22 and the second clutch 24. has become unaffected.

The elastic members 86 and 90 function as sealing members, and are provided between the friction plate 40 and the pressing plate 42 and between the friction plate 40 and the pressure plate 42.
The through holes 92 and 94 are provided between the press plate 42 and the second piston 50 to store a predetermined amount of hydraulic oil between the press plate 42 and the second piston 50. It is formed on the outer periphery. Therefore, between the friction plate 40 and the pressure plate 42, the hydraulic oil stored by the elastic member 86 flows out through the through hole 92 to maintain a constant oil amount, while the friction plate 40 and the second The hydraulic oil stored by the elastic member 90 flows through the through hole 94 between the piston 50 and the piston 50 .
A constant amount of oil is maintained by flowing out through. In this way, while the input shaft 16 is rotating, a certain amount of oil is stored between the friction plate 40 and the pressing plate 42 and between the friction plate 40 and the second piston 50, so that the amount of oil in the cylinder bore 44 is This effectively suppresses deterioration in the disengagement characteristics of the clutch due to centrifugal oil pressure generated in the pressure chamber 56 and the pressure chamber 58 in the cylinder bore 47, respectively.

That is, for example, as shown in FIG. 2, if the clutch case 26 is of an open type with discharge ports 80 and 82 on its outer periphery, the density of the hydraulic fluid for the first piston 46 is ρ, and the angular velocity is is ω, the inner and outer diameters of the first piston 46 are r ₁ and r ₂ , and the biasing force of the first return spring 54 is
f ₁ , the pressure chamber 5 for driving the first piston 46
When the hydraulic pressure applied to the first piston 6 is Pa, the driving force F ₁ of the first piston 46 is expressed by the following equation (1).

F ₁ = 1/4・πρω ² (r ₂ ⁴ − r ₁ ⁴ ) + πPa (r ₂ ² − _{r 1} ² ) − f ₁ ...(1) In other words, the first term on the right side of equation (1) is the pressure chamber This is the acting force of the centrifugal oil pressure generated in the pressure chamber 56 due to centrifugal force, and even if the working oil pressure Pa acting on the pressure chamber 56 becomes zero, the first return spring 54's biasing force f ₁ The returning force of the piston 46 was not sufficient, and the disengagement characteristics of the first clutch 22 were degraded.

Regarding the second piston 50, the second piston 5
The inner diameter and outer diameter of the piston 50 are r ₃ and r ₄ , the biasing force of the second return spring 55 is f ₂ , and the second piston 50 is
If the hydraulic pressure applied to the pressure chamber 58 to drive is Pb, the driving force of the second piston 50 is F ₂
is shown in the following equation (2), and the first piston F ₂ = 1/4・πρω ² (r ₄ ⁴ − r ₃ ⁴ ) + πPb (r ₄ ² − r ₃ ² ) − f ₂ ...(2 ) As in the case of engine 46, the clutch disengagement characteristics were degraded.

However, according to this embodiment, as described above, the sealing action of the elastic members 86 and 90 and the evacuation action of the through holes 92 and 94 are utilized to create a gap between the friction plate 40 and the pressing plate 42 and Since a certain amount of hydraulic oil is stored between the second piston 50 and the second piston 50, problems caused by centrifugal hydraulic pressure are suitably eliminated. That is, in FIG. 1, the distances from the center of rotation to the liquid surface and the bottom surface of the hydraulic oil stored by the elastic member 86 are r ₁₁ and r ₁₂ , respectively, and the distances from the center of rotation to the elastic member 9 are r 11 and r 12 , respectively.
If the distances to the liquid level and the bottom of the hydraulic oil stored by 0 are r ₂₃ and r ₂₄ , respectively, then the stored hydraulic oil is affected by the centrifugal hydraulic pressure shown in the following equations (3) and (4). Forces f _C1 and f _C2 are generated, respectively.

f _C1 = 1/4・πρω ² (r ₁₂ ² − r ₁₁ ² ) ² ……(3) f _C2 = 1/4・πρω ² (r ₂₄ ² − r ₂₃ ² ) ² ……(4) The above action Since the forces f _C1 and f _C2 act in a direction to assist the biasing force f ₁ of the first return spring 54 and the biasing force f ₂ of the second return spring 55, the above equations (1) and (2) are satisfied. It is added to the right side of the expression with a negative sign. For this reason, the above acting force
f _C1 and f _C2 are canceled out by the first term on the right side of equations (1) and (2), and the first piston 4 in the rotating state
6 and the second piston 50 are increased so that the first clutch 22 and the second clutch 24
The cutting characteristics are improved.

Although one embodiment of the present invention has been described above based on the drawings, the present invention can also be applied to other aspects.

For example, in the above-described embodiment, the elastic members 86 and 90 are formed in an annular shape, but they may be discontinuous members in the circumferential direction with grooves opening on the inner circumferential side.

Additionally, in the embodiments described above, the first clutch 22 and the second clutch 24 are provided with elastic members 86 and 90.
are respectively provided, but there is no problem even if only one clutch is provided.

Further, in the above embodiment, the elastic member 86 is located between the pressing plate 42 and the friction plate 40, and the elastic member 90 is located between the friction plate 40 and the second piston 50.
Although it is configured to be elastically deformed between the two members, it may also be compressed via another member. In short, the first piston 46 or the second piston 50
It suffices if it is disposed at a position where it is compressed as it moves forward.

In addition, the elastic members 86 and 90 may each store a predetermined amount of hydraulic oil;
The through holes 92 and 94 do not necessarily need to be provided as long as the hydraulic oil overflows from the annular grooves 84 and 88.

Also, although the above-described embodiment is a multi-clutch device having a first clutch 22 and a second clutch 24, a device having a single clutch may also be used.

The above-mentioned embodiment is merely an embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a multiple clutch device according to an embodiment of the present invention. FIG. 2 is a diagram corresponding to FIG. 1 showing a conventional multiple clutch device. 12... Multiple clutch device (hydraulic clutch device) 16... Input shaft, 18... Output shaft, 26...
Clutch case, 30...Second rotor, 38...
First rotor, 44, 47... Cylinder bore, 46
...First piston, 50 ...Second piston, 8
0, 82... Discharge port, 84, 88... Annular groove (groove), 86, 90... Elastic member (sealing member).

Claims (1)

[Claims for Utility Model Registration] An input shaft and an output shaft, a clutch case that rotates together with one of the input shaft and the output shaft,
a rotor that rotates together with the other of the input shaft and the output shaft; and a piston that is slidably fitted into a cylinder bore formed in the clutch case and connects the input shaft and the output shaft by pressing the rotor. In a hydraulic clutch device of a type in which hydraulic oil for cooling is allowed to flow into the clutch case, a discharge port for discharging the hydraulic oil that has flowed into the clutch case to the outside is provided in the clutch case. A hydraulic type, characterized in that a sealing member is provided on the outer periphery and has a groove that opens toward the inner periphery to store a predetermined amount of hydraulic oil, and is elastically deformed as the piston moves. clutch device.