JP3475730B2 - Relief valve structure of fastening clutch - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relief valve structure for a fastening clutch which maintains a constant pressure of a working fluid applied to the piston when the piston engages with a multiple disc clutch.

[0002]

2. Description of the Related Art An automatic transmission is provided with a control valve for adjusting an operating pressure supplied to a transmission mechanism incorporated in a transaxle and for switching a hydraulic circuit. This control valve is usually mounted at the bottom of the automatic transmission so as to be hidden in the oil pan.

Inside the control valve, like the valve body 1 shown in FIG. 5, a groove (hydraulic circuit) intricately integrated like a honeycomb, a spring and a cylindrical valve (not shown) are arranged. ing. A part of the hydraulic circuit is connected to a speed change mechanism such as a fastening clutch and a brake, and an oil pump.

Here, the valve body 1 has a structure shown in FIGS.
As shown in (1), the relief valve 2 is provided to lower the hydraulic oil to the set pressure when the hydraulic oil to be supplied to the engagement clutch is boosted for some reason.

The relief valve 2 has a cylindrical relief hole 3 formed in the valve body 1, and a drain hole 4 for communicating the relief hole 3 with the outside is formed at the bottom of the relief hole 3. Then, the spring 5 is provided on the bottom side of the relief hole 3.
Is inserted, the ball 6 is arranged on the opening side of the relief hole 3, and the relief hole 3 is closed by the closing plate 7 having the through hole 7a. Then, when the hydraulic oil in the oil passage 8 becomes equal to or higher than the set pressure, the hydraulic pressure acts on the ball 6 against the biasing force of the spring 5.
Since the working oil is pushed up and the working oil flows out through the relief hole 3 and the drain hole, the working oil held at the set pressure is always supplied to the engagement clutch.

[0006]

However, since the relief valve 2 described above is arranged in the valve body 1 in which the hydraulic circuit is complicated, the number of valves can be increased and the arrangement position can be freely laid out. Difficult to do.

Further, usually, the relief hole 3 and the drain hole 4
Is formed by drilling in the final step of manufacturing the valve body 1. However, the facets generated at that time may enter the groove forming the hydraulic circuit, and the facets may be completely removed after the hole is formed. It takes a lot of work to remove it.

Therefore, the present invention has been made by paying attention to the unsolved problem of the above-mentioned conventional example, and the degree of freedom of layout can be improved, and the number of relief valves can be appropriately increased or decreased, and easily. An object of the present invention is to provide a relief valve structure for an engagement clutch that can be manufactured.

[0009]

In order to achieve the above object, the invention of claim 1 is such that a clutch drum that rotates together with an input shaft and a part of the clutch members are engaged with the clutch drum, and an axial direction A multi-disc clutch that can be fastened to each other by movement and transmitted to the output side of the rotational force transmitted to the clutch drum; and a multi-disc clutch that is coaxially arranged inside the clutch drum and moves toward the multi-disc clutch member. Possible piston, a cylinder chamber provided between the clutch drum and the opposing wall of the piston and supplied with working fluid, and arranged at a predetermined interval on a predetermined circumference centered on the axis of the piston A plurality of return springs that come into contact with the wall surface of the piston that does not face the clutch drum and presses the piston in a direction away from the multi-plate clutch member In conclusion clutch with a door,
The piston is formed with a relief hole penetrating from the wall surface with which the return spring is in contact toward the cylinder chamber, and a relief ball is brought into contact with the opening of the relief hole opened on the return spring side, and the relief is formed. A predetermined return spring directed toward the hole presses the relief ball to close the relief hole, and a predetermined return pull pressing the relief ball is pressed so that the pressure of the working fluid in the cylinder chamber becomes a predetermined value or more. The spring constant was set to release the blockage of the relief hole by the relief ball when it reached.

According to a second aspect of the present invention, in the relief valve structure for a fastening clutch according to the first aspect, the relief hole, the relief ball, and the predetermined return spring for pressing the relief ball are connected to the shaft of the piston. At least one pair is disposed at positions symmetrical to each other.

[0011]

According to the first aspect of the present invention, a relief hole communicating with the cylinder chamber is formed in the piston, which is a component of the engaging clutch of the cylinder chamber, and the relief ball is brought into contact with the opening of the relief hole. Since a relief valve that closes the relief hole is formed by pressing the relief ball using a predetermined return spring,
Compared with the structure in which a relief valve is provided in the control valve as in the prior art, the degree of freedom in layout is improved, and the number of relief valves can be freely set according to the setting of relief pressure.

According to the second aspect of the present invention, at least a pair of predetermined return springs for pressing the relief ball are arranged at positions symmetrical to each other with respect to the axis of the piston. It is possible to normally press the piston together with other return springs without giving a biased pressing force to the.

Further, since at least a pair of relief balls are arranged at positions symmetrical to each other with respect to the axis of the piston, the weight balance when the piston rotates can be normally maintained.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a transaxle incorporating a continuously variable automatic transmission mechanism, which includes a torque converter 20, a forward / reverse switching mechanism 22, a V-belt continuously variable transmission mechanism 24, a differential device 26, and the like.

The input side of the torque converter 20 is connected to the rotary shaft 28a of the engine 28, and the output side thereof is connected to the input shaft 23 of the forward / reverse switching mechanism 22. Further, the forward / reverse switching mechanism 22 includes the planetary gear mechanism 30 and the forward clutch 3
2 and a reverse clutch 34, an output shaft 38 is connected to a sun gear of a planetary gear mechanism 30, which will be described later, and a drive pulley 40 of the V-belt type continuously variable transmission mechanism 24 is provided on the output shaft 38. .

The V-belt type continuously variable transmission mechanism 24 comprises a drive pulley 40, a V-belt 42 and a driven pulley 44. The drive pulley 40 is composed of a fixed conical plate 46 that rotates integrally with the output shaft 38, and a movable conical plate 48 that is movable in the axial direction of the output shaft 38. Further, the drive pulley 40 is connected to a driven pulley 44 by a V belt 42 so as to be able to be transmitted. The driven pulley 44 has a driven shaft 50.
And a movable conical plate 54 that is movable in the axial direction of the driven shaft 50.

The driven shaft 50 has a parking 56.
And the drive gear 58 are fixed to each other, and the drive gear 58 meshes with the idler gear 62 on the idler shaft 60.
Further, the pinion 64 provided on the idler shaft 60 always meshes with the final gear 66. In addition, the final gear 66 includes a pair of pinions 6 that constitute the differential device 26.
8 and 70 are attached, the pinions 68 and 70 mesh with the pair of side gears 72 and 74, and the output shafts 76 and 78 are connected to the side gears 72 and 74, respectively.

The rotational force input from the output shaft 28a of the engine 28 is transmitted to the forward / reverse switching mechanism 22 via the torque converter 22 and the input shaft 23, and the forward clutch 32 is engaged and the reverse clutch is engaged. When 34 is released, the rotational force of the input shaft 23 is transmitted to the output shaft 38 in the same rotation direction via the planetary gear mechanism 30 that is in the integrally rotating state.

On the other hand, when the forward clutch 32 is released and the reverse clutch 34 is engaged, the rotational force of the input shaft 23 is reversed by the action of the planetary gear mechanism 30. It is transmitted to the output shaft 38. The rotational force of the output shaft 38 is transmitted to the differential device 26 via the drive pulley 40, the V belt 42, the driven pulley 44, the driven shaft 50, the drive gear 58, the idler gear 62, the idler shaft 60, the pinion 64, and the final gear 66. And the left and right drive shafts 76, 78 rotate in the forward or reverse direction.

During this power transmission, the drive pulley 40, the movable conical plate 48 and the movable conical plate 54 of the driven pulley 44 are controlled by the hydraulic pressure supply control to the hydraulic chamber 41 of the drive pulley 40 and the hydraulic chamber 45 to the driven pulley 44. The rotation ratio between the drive pulley 40 and the driven pulley 44 can be changed by moving in the axial direction to change the contact position radius with the V belt 42.

Next, FIG. 2 shows a specific structure of the forward / reverse switching mechanism 22, which is a transaxle case 80.
Inside, an input shaft 23 and an output shaft 38 are coaxially arranged on the axis S. A planetary gear mechanism 30 is arranged on the outer circumference of the output shaft 38, and the input shaft 23 and the output shaft 38 can be appropriately coupled via the planetary gear mechanism 30 and the forward clutch 32, and the planetary gear mechanism 30 can be appropriately connected. Gear mechanism 30
And the input shaft 23 and the output shaft 3 via the reverse clutch 34.
8 and 8 can be combined appropriately.

That is, the planetary gear mechanism 30 has the output shaft 3
8, a sun gear 30S splined with the outer periphery of the ring 8, a ring gear 30R disposed on the outer periphery of the sun gear 30S, a plurality of pinions 30P meshing between the sun gear 30S and the ring gear 30R, and a pinion 30P at a disc portion orthogonal to the axis S. It is a simple planetary gear set composed of a cylindrical reverse clutch hub 34a that is rotatably supported.

Further, the reverse clutch 34 engages with the outer periphery of the cylindrical portion of the reverse clutch hub 34a to transmit the rotational force of the reverse clutch hub 34a, so that the drive plate is slidable in the direction of the axis S. 34b, a driven plate 34c that engages with the inner circumference of the transaxle case 80 and is slidable in the direction of the axis S, and alternately enters between the drive plates 34b, and a retainer plate that holds the drive plate 34b and the driven plate 34c. 2d, the reverse clutch piston 34e that brings the drive plate 34b and the driven plate 34c into the engaged state by moving to the right in the direction of the axis S in FIG. 2, and the direction away from the drive plate 34b and the driven plate 34c (the axis line in FIG. 2). Push the reverse clutch piston 34e to the left side in the S direction) A return spring 34f, the predetermined pressure hydraulic fluid and a reverse clutch cylinder chamber 34g to move the reverse clutch piston 34e in the drive plate 34b and the driven plate 34c side by supplying that.

On the other hand, the forward clutch 32 is a cylindrical body which is disposed inside the reverse clutch hub 34a and rotates integrally with the input shaft 6, and the ring gear 30R of the planetary gear mechanism 30 is provided on the inner periphery of the distal end of the cylindrical portion. Clutch drum 3 with fixed
2a, the forward clutch hub 32b disposed inside the clutch drum 32a while rotating integrally with the sun gear 30S of the planetary gear mechanism 30, and the rotational force of the clutch drum 32a engaged with the inner peripheral side of the clutch drum 32a. Is transmitted, and the rotational force of the forward drive clutch hub 32b is transmitted by engaging with the plurality of driven plates 32c slidable in the axial direction S and the outer peripheral side of the forward drive clutch hub 32b, and the rotational force of the forward drive clutch hub 32b is transmitted. A plurality of drive plates 3 which are slidable in the space and alternately enter between the driven plates 32c.
2d and a retaining plate 32e that holds the driven plate 32c and the drive plate 32d.

Then, as shown in FIG. 3, the driven plate 32c and the drive plate 32d are provided inside the clutch drum 32a by the leftward movement in the direction of the axis S in the drawing.
A forward clutch piston 32f that disengages the vehicle is disposed. The forward clutch piston 32f includes a plurality of return springs 32 arranged on a predetermined circumference.
The return spring 32h is pressed to the right in the axial direction of the drawing by h, and each return spring 32h is held by a spring retainer 32g engaged with the inner diameter portion of the clutch drum 32a.

A forward clutch cylinder chamber 32j is formed between the inner wall of the clutch drum 32a and the wall surface of the forward clutch piston 32f facing the inner wall, and an oil passage is formed in the forward clutch cylinder chamber 32j. 82
When hydraulic oil of a predetermined pressure (hereinafter referred to as fastening pressure P ₁ ) is supplied from the above, the forward clutch piston 32f moves to the left side in the direction of the axis S in the figure against the biasing force of the return spring 32h. The driven plate 32c and the drive plate 32d are brought into a fastening state.

Here, the forward clutch 32 is provided with a relief valve 82 for setting the maximum pressure of the hydraulic oil in the forward clutch cylinder chamber 32j (a pressure significantly higher than the engagement pressure P ₁ ).

That is, FIG. 4 shows the spring retainer 3
Although the forward clutch piston 32f is shown from the 2g side, a ring groove 32k is formed in the forward clutch piston 32f, and the bottom of the ring groove 32k penetrates toward the forward clutch cylinder chamber 32j. Four relief holes 84 are formed. These relief holes 84 have an axis line S between the two relief holes 84.
Are provided at positions symmetrical to each other. Then, as shown in FIG. 3, the opening of each relief hole 84 on the spring retainer 32g side is closed by a relief ball 86, and a plurality of return springs 3 are provided.
Of the 2h, the four return springs 32h corresponding to the relief holes 84 pass the relief balls 86 through the through holes 84.
Pressing towards.

As a result, the relief valve 82 has a relief hole 84 formed in the forward clutch piston 32f, a relief ball 86 that closes one opening of the relief hole 84, and the relief ball 86 directed toward the relief hole 84. The return spring 32h configured to press the return ball 32h that presses the relief ball 86 is the forward clutch cylinder chamber 32j.
When the hydraulic oil of _{No. 1} holds the closed state of the relief hole 84 by the relief ball 86 at the fastening pressure P ₁ or lower, the relief ball 86 relieves when the hydraulic oil of the forward clutch cylinder chamber 32j reaches the maximum pressure. The spring constant is set so as to release the closed state of the hole 84.

When the forward movement is selected, the forward movement clock is selected.
Fastening pressure P is applied to the latch cylinder chamber 32j. ₁Hydraulic fluid is supplied
For forward movement against the biasing force of the return spring 32h
The clutch piston 32f moves to the left side in FIG.
Therefore, the driven plate 32c is pressed to drive the drive plate.
The seat 32d and the driven plate 32c are in the fastening state.
It As a result, the forward rotation force of the input shaft 23 is
Drum 32a, driven plate 32c, drive pre
Via the gear 32d and the forward clutch hub 32b
The sun gear 30S is transmitted to the sun gear 30S of the vehicle mechanism 30.
The normal rotational force of S is transmitted to the output shaft 38.

When the reverse operation is selected, hydraulic oil is supplied to the reverse clutch cylinder chamber 34g, and the reverse clutch piston 34e moves to the right side in FIG. 2 against the biasing force of the return spring 34f. As a result, the front end portion of the reverse clutch piston 34e is moved to the drive plate 3
4b, the drive plate 34b and the driven plate 34c are brought into the engaged state, and the reverse clutch hub 3
4a is fixed. Then, the normal rotational force of the input shaft 23 is transmitted to the ring gear 30R of the planetary gear mechanism 30 via the clutch drum 32a, and the pinion 30P is fixed by the reverse clutch hub 34a. Is transmitted to the output shaft 38 via the sun gear 30S as a rotational force for reverse rotation.

Then, if the hydraulic oil supplied to the forward clutch cylinder chamber 32j rises above the fastening pressure P _{1 for} some reason, the return spring 32h pressing the relief ball 86 operates with the hydraulic pressure. Then, the relief ball 86 is pressed and contracted, and the closed state of the relief hole 84 by the relief ball 86 is released. As a result, the hydraulic fluid in the forward clutch cylinder chamber 32j flows out from the relief 84 to the outside, so that the forward clutch cylinder chamber 32j can be obtained in a short time.
j can be returned to the fastening pressure P ₁ .

According to the above-mentioned structure, the forward clutch piston 32f is provided with the relief hole 84 communicating with the forward clutch cylinder chamber 32j, the relief ball 86 is brought into contact with the opening of the relief hole 84, and the return spring 32h is provided. Since the relief ball 86 is pressed to block the relief hole 84 to form a relief valve,
Relief valve 8 in the control valve as in the prior art
Compared with the structure in which two are provided, the degree of freedom in layout is improved and the number of relief valves 82 can be set freely.

Two pairs of four return springs 32h, which press the relief balls 86, are arranged at positions symmetrical to each other with respect to the axis S of the forward clutch piston 32f. Does not give a biased pressing force to the forward clutch piston 32f, and can normally press the forward clutch piston 32f together with the other return spring 32h.

Further, since four pairs of the four relief balls 86 are also arranged at positions symmetrical to each other with respect to the axis S of the forward clutch piston 32f, the weight balance when the forward clutch piston 32f rotates. Can be held normally.

In this embodiment, the driven plate 32c and the drive plate 32d correspond to the multi-plate clutch according to claim 1, the forward clutch piston 32f corresponds to the piston according to claim 1, and the forward yaw clutch cylinder is used. The chamber 32j corresponds to the cylinder chamber described in claim 1.

Further, in this embodiment, the forward clutch 3
2 has a relief valve structure, but the reverse clutch 34
Even if the relief valve structure is applied to, the same effect can be obtained.

Further, even if the structure of the present invention is applied to the clutch structure of another power transmission section, the same effect can be obtained.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing a power transmission unit of an automatic transmission according to the present invention.

FIG. 2 is a cross-sectional view showing a forward / reverse switching mechanism used in the automatic transmission of FIG.

FIG. 3 is a sectional view showing details of a forward clutch of the forward / reverse switching mechanism.

FIG. 4 is a view showing the forward clutch piston of the forward clutch from the return spring side.

FIG. 5 is a view showing a valve body of a conventional control valve provided with a relief valve.

6 is a cross-sectional view taken along the line VI-VI of FIG.

[Explanation of symbols]

23 Input axis 30 Planetary gear mechanism 32 Forward clutch 32a clutch drum 32b Forward clutch hub 32c driven plate 32d drive plate 32f Forward clutch piston 32h return spring 32j Forward clutch cylinder chamber 34 Reverse clutch 38 Output shaft 84 Relief hole 86 relief ball

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-7-119759 (JP, A) JP-A-1-120436 (JP, A) JP-A-5-164143 (JP, A) JP-A-8- 338455 (JP, A) Actual Kaihei 5-52370 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16D 25/06-25/12

Claims (2)

(57) [Claims] 1. A clutch drum that rotates together with an input shaft and a part of the clutch member are engaged with the clutch drum and fastened together by axial movement to transmit the rotational force transmitted to the clutch drum to the output side. And a piston that is coaxially arranged inside the clutch drum and is movable toward the multi-disc clutch member, and that is provided between the opposing walls of the clutch drum and the piston. Cylinder chamber to which the working fluid is supplied,
The pistons are arranged at a predetermined interval centered on the axis of the piston at a predetermined interval, contact the wall surface of the piston that does not face the clutch drum, and press the piston in a direction away from the multi-plate clutch member. A plurality of return springs, wherein the piston is provided with a relief hole penetrating from the wall surface on which the return spring is in contact toward the cylinder chamber, and the return spring is opened. A relief ball is brought into contact with the opening of the relief hole, and the relief ball is pressed by a predetermined return spring directed to the relief hole to close the relief hole, and a predetermined return pulling that presses the relief ball is provided. , When the pressure of the working fluid in the cylinder chamber reaches a certain value or more A relief valve structure for a fastening clutch, wherein a spring constant is set to release the blockage of the relief hole by the relief ball. 2. At least one pair of the relief hole, the relief ball, and the predetermined return spring for pressing the relief ball are arranged at positions symmetrical to each other with respect to the axis of the piston. The relief valve structure for the engagement clutch according to Item 1.