JPH07332389A - Liquid pressure type clutch release cylinder device - Google Patents

Abstract

PURPOSE:To reduce the quantity liberated through the evaporation of the working liquid and suppress the reduction of the working liquid by installing a seal means in close contact in liquid seal form with the inner surface of each cylinder, at the inner end part in the axial direction of a piston and the intermediate part, keeping the equal interval to the necessary stroke of a clutch release cylinder device. CONSTITUTION:A liquid pressure type clutch release cylinder device 1 has a cylinder 2 having an annular groove 3 which is coaxial with an input shaft 7, set along the axis line direction of the input shaft 7 of a transmission and is constituted by fitting a cylindrical piston 4 into the annular groove 3, and a release bearing 6 is fixed at the outer side edge of the piston 4. In this case, sealing means 20, 28, and 29 which are closely attached in liquidtight form with the inner surface of the annular groove are formed at the inner end part in the axis line direction and the intermediate part of the piston 4, keeping the equal interval to the necessary stroke of the device 1. The dimension in the axis lime direction of the intermediate part seal means 28 and 29 from the annular groove 3 when the piston 4 is at the full stroke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic clutch release cylinder device, and more particularly to a hydraulic cylinder release cylinder device in which a slave cylinder is provided coaxially with an input shaft of a transmission and a release bearing is directly driven by a piston of the slave cylinder. The present invention relates to a clutch release cylinder device.

[0002]

2. Description of the Related Art The output transmission capacity of a clutch must be increased as the output of an engine increases, and for that purpose, it is necessary to strengthen the coupling force of the clutch. This strengthening of clutch coupling force is accompanied by an increase in release operation force,
In recent years, reduction of operating force has been raised as one of the important issues in designing a release mechanism.

As a release mechanism capable of reducing the pedal effort of the clutch pedal, a CSC (Concentric Slave Cylinder) type release device in which a release bearing can be directly driven by a slave cylinder concentrically provided with an input shaft is provided. Proposed in US Pat. No. 4,983,332 and the like. This is to accommodate a cylindrical piston slidably in an axial direction in a slave cylinder consisting of an annular groove, and to supply the hydraulic pressure of a master cylinder from the bottom of the slave cylinder. By using the piston, a large pressure receiving area can be obtained without hindering compactness.

In the CSC type release device, when the piston is pushed out, the slave cylinder is filled with the working fluid, but when the piston is pulled in, the working fluid is not completely scraped off and remains on the inner surface of the annular groove. Then, a thin film is formed. On the other hand, in order to ensure the smoothness of the sliding movement, a predetermined gap is indispensable between the piston and the annular groove, so the hydraulic fluid adhering to the inner surface of the annular groove evaporates when the outside air is hot Dissipate from.

[0005]

In the CSC type release device in which the piston has a cylindrical shape and the slave cylinder has an annular groove, the area of the mutual sliding contact surface between the piston and the cylinder is significantly larger than that of the conventional type. However, there is an inconvenience that the amount of hydraulic fluid reduced due to such diffusion is larger than that of the conventional type.

The present invention has been devised in order to eliminate such disadvantages of the prior art, and its main purpose is to:
It is an object of the present invention to provide a hydraulic clutch release cylinder device configured to reduce the amount of decrease in the clutch hydraulic fluid.

[0007]

According to the present invention, such an object is to provide a cylinder having an annular groove deep along the axial direction of the input shaft of the transmission and coaxial with the input shaft, and an annular groove. In a hydraulic clutch release cylinder device having a tubular piston that is received and pushed out by the hydraulic pressure in the annular groove, and a release bearing fixed to the outer end of the piston, and the required stroke of the clutch release cylinder device. Sealing means are provided at the inner end of the axial direction of the piston and the intermediate portion at equal intervals so as to make liquid-tight contact with the inner surface of the annular groove, and when the piston makes a full stroke, the sealing means of the intermediate portion is annular. This is accomplished by setting the axial dimension of the cylinder to a length that does not slip out of the groove.

[0008]

With this structure, the thin film of the hydraulic fluid formed on the inner surface of the annular groove does not come into contact with the outside air when the piston slides. Therefore, the amount of evaporation and diffusion is reduced, and the reduction of hydraulic fluid is suppressed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to specific embodiments shown in the accompanying drawings.

FIGS. 1 and 2 show a clutch release cylinder device constructed according to the present invention. The upper side from the center line in FIG. 1 shows the clutch disengaged state, and the lower side shows the clutch engaged state. This clutch release cylinder device 1
Is a cylinder 2 fixed to the transmission housing side, a cylindrical piston 4 that slides in an annular groove 3 formed in the cylinder 2, and a release bearing 6 fixed to the outer end of the piston 4 via a bearing seat 5. And is mounted coaxially with the input shaft 7 of the transmission.

The cylinder 2 has cylindrical portions 8a and 8b and flange portions 9a and 9b formed outward at one end of the cylindrical portions.
It is a combination of two members consisting of and. These two members are formed by drawing a metal material, the cylindrical portions 8a and 8b have different diameters, and the flange portions 9a and 9b have the same outer contour. A deep annular groove 3 is formed along the axis of the input shaft 7 between the two cylindrical parts 8a and 8b that are double-sided. Again 2
The flange portions 9a and 9b of one member are liquid-tightly joined by sandwiching the gasket 10 therebetween.

The flange portions 9a and 9b are provided with a pair of ears 11 on a radial line. Then, in the round hole 12 formed in the ear portion formed in the flange portion 9a of the member having the cylindrical portion 8a located on the outer peripheral side of the two members,
The connector member 13 is fitted through the O-ring 14.

The connector member 13 has a pipe joint 15 bent in an L-shape, and an O-ring 16 at the end thereof.
It has been fitted after being attached. A flange portion 17 is formed at an end portion of the pipe joint 15, and a pin 18 having a pin shape is inserted into the connector member 13 so as to press the flange portion 17, thereby the pipe joint 1
It is designed so that 5 does not come out. In addition, gasket 1
0 is arranged so as to circumvent the portion of the connector member 13 to the outside, whereby a gap 19 is formed between the flange portions 9a and 9b. The gap 19 forms a hydraulic passage extending from the pipe joint 15 to the annular groove 3.

The piston 4, which is slidably received in the annular groove 3 along the axial direction, is liquid-tightly fitted in the annular groove 3 with a seal member 20 provided at the inner end thereof. Further, the piston 4 is a diaphragm spring 2 that is displaced according to wear of a clutch facing (not shown).
A preload spring 22, which is compressed around the cylinder 2 so as to press the release bearing 6 so as to follow the inner end position of 1, is constantly urged in the pushing direction with a low load.

The preload spring 22 has one end 2
2a is locked to the outer end of the piston 4, and the other end 22b is locked to the connector member 13. The torsional resistance of the preload spring 22 prevents the piston 4 from rotating together. Further, the outer peripheral portion of the preload spring 22 is surrounded by a bellows-shaped dust boot 23 connected between the retainer member 25 integrally formed with the caulking metal fittings of the flange portions 9a and 9b and the outer end portion of the piston 4. The dust and the like are prevented from adhering to the piston 4. Note that the preload spring 22 and the dust boot 23 are not shown in FIG.

The release bearing 6 has a self-aligning mechanism, and the contact flange 24 fixed to the inner race is brought into uniform contact with the center of the diaphragm spring 21 in the circumferential direction.

Next, the operating procedure of the above-mentioned device will be described. When the clutch pedal is not depressed, that is, the hydraulic pressure is not applied, the release spring 6 is pressed by the diaphragm spring 21 and is located on the transmission housing side. In this state, the reaction force of the diaphragm spring 21 causes the pressure plate (not shown) to press the clutch disc toward the flywheel, and the power of the engine is transmitted to the transmission.

Hydraulic pressure from a master cylinder (not shown) is passed through one pipe joint 15 to both flange portions 9a.
When entering the annular groove 3 through the gap 19 between the 9b, the annular piston 4 is pushed out. As a result, the release bearing 6 is pushed out together with the bearing seat 5 provided integrally with the piston 4, and the central portion of the diaphragm spring 21 is pushed to release the pushing force of the pressure plate. This disengages the clutch disc from the flywheel and interrupts the transmission of engine power to the transmission.

Now, in the case of the clutch release cylinder device having the above structure, the annular groove 3 is formed when the piston 4 is pushed out.
When the piston 4 is drawn in, the working fluid is filled therein, and the working fluid is scraped off by the seal member 20 at the end of the piston and returns to the reservoir, but in reality, all of the working fluid is scraped off from the annular groove 3. However, a part of the working fluid remains attached and forms a thin film of the working fluid on the inner surface of the annular groove 3. When this evaporates and dissipates from the gap between the annular groove 3 and the piston 4, the working fluid is reduced for a long period of time, and the influence becomes apparent.

Therefore, in the present invention, as shown enlarged in FIG. 3, the inner and outer peripheries of the piston 4 at a position spaced from the seal member 20 at the inner end in the axial direction by a distance A equivalent to the piston stroke. The circumferential grooves 26, 27 are provided on the surface, and intermediate seals 28, 29, which are O-rings that are liquid-tightly adhered to the inner surface of the annular groove 3, are mounted in the circumferential grooves 26, 27, and the piston is The axial dimension of the cylinder 2 is set to a length such that the intermediate seals 28 and 29 do not slip out of the annular groove 3 when the full stroke of 4 is made.

As a result, the working fluid adhering portion on the inner surface of the annular groove 3 is sealed, and the evaporation / dissipation of the working fluid is prevented.

The gap G between the seal member 20 at the inner end in the axial direction and the intermediate seals 28 and 29 may be a cavity as it is, but if grease or the like is filled in, a sealing property and smoothness of sliding are provided. Is preferred, which is preferable.

The intermediate seal is not limited to the above-mentioned O-ring, and the protrusions 31 and 32 are provided at both ends of the tubular body 30 having the axial dimension equivalent to the piston stroke as shown in FIG. In other words, the seal member at the inner end of the piston and the intermediate seal may be integrally formed on the base of the tubular body.

[0024]

As described above, according to the present invention, the amount of the thin film of the working fluid formed on the inner surface of the annular groove of the cylinder when the piston slides is reduced because it does not come into contact with the outside air and evaporates and diffuses. , Is effective in suppressing the decrease in hydraulic fluid.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a hydraulic clutch release cylinder device according to the present invention.

FIG. 2 is a partially cutaway side view of a hydraulic clutch release cylinder device according to the present invention.

FIG. 3 is a partial enlarged sectional view of a piston seal portion according to the present invention.

FIG. 4 is a partial enlarged cross-sectional view of another embodiment of the present invention.

[Explanation of symbols]

 1 Hydraulic clutch release cylinder device 2 Cylinder 3 Annular groove 4 Piston 5 Bearing seat 6 Release bearing 7 Input shaft 8a / 8b Cylindrical part 9a / 9b Flange part 10 Gasket 11 Ear part 12 Round hole 13 Connector member 14 O-ring 15 Pipe joint 16 O-ring 17 Collar 18 Pin 19 Gap 20 Sealing member 21 Diaphragm spring 22 Preload spring 23 Dust boot 24 Contact flange 25 Retainer member 26/27 Circumferential groove 28/29 Intermediate part seal 30 Cylindrical body 31/32 Projection

Claims (1)

[Claims] 1. A cylinder having an annular groove deep along the axial direction of the input shaft of the transmission and coaxial with the input shaft, and a cylinder received in the annular groove and pushed out by hydraulic pressure in the annular groove. A hydraulic clutch release cylinder device having a piston-shaped piston and a release bearing fixed to the outer end of the piston, and in the axial direction of the piston at an interval equal to the required stroke of the clutch release cylinder device. The end portion and the intermediate portion are each provided with sealing means that is in liquid-tight contact with the inner surface of the annular groove, and the sealing means of the intermediate portion does not come out of the annular groove when the piston makes a full stroke. A hydraulic clutch release cylinder device characterized in that the axial dimension of the cylinder is set.