JP2004060750A - Clutch device of hydraulic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a clutch device of a hydraulic transmission while securing sealability of a hydraulic chamber. <P>SOLUTION: An elastic member 84 is covered over the inner surface of a small cylinder section 32 of a support plate 3, and is compressed while providing a predetermined fastening allowance with a small cylinder section 12 of the housing 1. This can prevent leakage of operation oil and infiltration of wear debris, an installation space of an O-ring is not required to be secured in an axial midway of an engaging region between the support plate 3 and the housing 1 differently from the prior art, and the clutch device can be miniaturized. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a clutch device for a hydraulic transmission.
[0002]
[Prior art]
FIG. 6 shows an upper half of a clutch device of a hydraulic transmission according to a conventional example. In the figure, 71 is a housing, 72 is a piston, 73 is a support plate, 74 is a reverse spring, 75 is a C-shaped retaining ring, and 76 and 77 are O-rings.
[0003]
The housing 71 has a large cylindrical portion 78, a small cylindrical portion 79, and an annular wall portion 80. The O-rings 76 and 77 seal the fitting portions of the small cylinder portion 79 with the piston 72 and the support plate 73, and are provided in circumferential grooves 81 and 82 provided on the outer peripheral surface of the small cylinder portion 79. It is installed.
[0004]
[Problems to be solved by the invention]
In the above-mentioned conventional example, it is necessary to secure an installation space for the O-rings 76 and 77 in the axial direction halfway of the fitting area between the small cylinder portion 79 of the housing 71 and the piston 72 and the support plate 73. This is a factor of the increase in size and complexity. In addition, it is pointed out that a step of forming the peripheral grooves 81 and 82 in which the O-rings 76 and 77 are provided is required, and the manufacturing cost is increased.
[0005]
[Means for Solving the Problems]
The present invention provides a housing that forms an annular space by connecting one axial side of a large cylindrical portion and a small cylindrical portion that are concentrically arranged with an annular wall portion, and includes a housing inside the large cylindrical portion with respect to the annular space. A piston which is slidably accommodated in the axial direction using the peripheral surface and the outer peripheral surface of the small cylinder portion as a guide surface to form a hydraulic chamber between the opposing surfaces of the annular wall portion, and the piston on the outer peripheral surface of the small cylinder portion. A support plate that is externally mounted slidably only in a direction approaching the annular wall portion with respect to a position axially separated from the annular wall portion by a predetermined distance, and an axial direction between the support plate and the piston. A reverse spring that is interposed in a compressed state and presses the piston toward the annular wall by an elastic restoring force, and a fitting surface between the support plate and the small cylinder portion is provided on an inner periphery of the support plate. One elastic member to seal It has been applied to.
[0006]
In this case, unlike the conventional example, it is not necessary to provide a circumferential groove for installing an O-ring in the axial direction of the fitting portion between the support plate and the housing, so that the axial dimension of the fitting portion is reduced. As a result, the size of the clutch device can be reduced. Further, the labor for machining the circumferential groove can be saved, and the O-ring mounting step which requires accurate and careful work is not required, so that the manufacturing cost can be reduced.
[0007]
Meanwhile, an elastic member that seals a fitting surface between the piston and the small cylinder portion can be integrally attached to an inner periphery of the piston.
[0008]
In this case, in addition to the above-described functions and effects, the axial dimension of the fitting portion between the piston and the housing can be shortened, and the size of the clutch device can be further reduced.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
1 and 2 show a first embodiment of the present invention.
[0010]
The clutch device for a hydraulic transmission according to the present embodiment includes a housing 1, a piston 2, a support plate 3, and a reverse spring 4.
[0011]
The housing 1 has a shape in which one side in the axial direction of a small cylindrical portion 12 and a large cylindrical portion 13 arranged concentrically is connected by an annular wall portion 11. Further, the large cylindrical portion 13 has a shape having a small diameter portion 13a and a large diameter portion 13b.
[0012]
The piston 2 is manufactured by bending a metal plate, and the one side in the axial direction of the small cylindrical portion 22 and the large cylindrical portion 23 that are arranged concentrically is substantially the same as the shape of the housing 1 in an annular wall portion. It is a shape connected at 21.
[0013]
The support plate 3 is manufactured by bending a metal plate. The support plate 3 includes a small tube portion 32 and a large tube portion 33 which are concentric and extend in the axial direction opposite to each other on the inner and outer circumferences of the annular plate portion 31 along the radial direction. It has a provided shape. Further, the large cylinder portion 33 is provided with a flange 34 extending from its free end toward the outer diameter side. The support plate 3 is fitted on the outer peripheral surface of the small tube portion 12 of the housing 1 at a position axially separated from the annular wall portion 11 by a predetermined distance. Is contacted with a C-shaped retaining ring 6 provided on the outer diameter portion of the small cylindrical portion 22 of the housing 1 so that the support plate 3 can slide only in a direction approaching the annular wall portion 11. Are positioned away from the annular wall portion 11.
[0014]
The reverse spring 4 is interposed between the support plate 3 and the piston 2 while being compressed in the axial direction. The reverse spring 4 presses the piston 2 toward the annular wall 11 of the housing 1 by its elastic restoring force.
[0015]
The piston 2 is axially slidably accommodated in the annular space 18 of the housing 1 with the inner peripheral surface of the large cylindrical portion 13 of the housing 1 and the outer peripheral surface of the small cylindrical portion 12 as guide surfaces. The hydraulic chamber 7 is formed between the annular wall 11 of the housing 1 and the opposed surface of the annular wall 21 of the piston 2. In order to ensure the tightness of the hydraulic chamber 7, a lip 81 and an O-ring 82 are provided at predetermined positions between the housing 1 and the surface facing the piston 2.
[0016]
The lip 81 is attached so as to extend obliquely outward in the radial direction at the corner of the boundary between the annular plate portion 21 and the large cylindrical portion 23 on the outer surface of the piston 2, and is provided on the inner peripheral surface of the large cylindrical portion 13 of the housing 1. Is in contact with
[0017]
The O-ring 82 is housed in a peripheral groove 16 provided on the outer peripheral surface of the small cylindrical portion 12 of the housing 1, and is in contact with the inner peripheral surface of the small cylindrical portion 22 of the piston 2.
[0018]
A lip 83 and an elastic member 84 are provided at predetermined positions on the support plate 3.
[0019]
The lip 83 is attached to the outer peripheral edge of the flange 34 of the support plate 3 so as to extend diagonally outward in the radial direction, and is in contact with the inner peripheral surface of the large cylindrical portion 23 of the piston 2.
[0020]
The elastic member 84 is attached to the inner peripheral surface of the small tubular portion 32 of the support plate 3 and is in contact with the outer peripheral surface of the small tubular portion 12 of the housing 1.
[0021]
Suitable materials for the lip 81, the O-ring 82, the lip 83, and the elastic member 84 include, for example, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), elastomer, and synthetic rubber. Hydrogenated nitrile rubber (HNBR), which is excellent in both heat resistance and heat resistance, is most preferable.
[0022]
Here, the elastic member 84 will be described in detail.
[0023]
The elastic member 84 has a gasket shape, and is vulcanized and bonded to the inner peripheral surface of the small cylindrical portion 32 of the support plate 3. The elastic member 84 is compressed with a predetermined interference a between the small tube portion 32 of the support plate 3 and the small tube portion 12 of the housing 1. The degree of compression is adjusted by appropriately managing the interference a from the viewpoint of preventing leakage of operation oil and intrusion of wear powder. Preferably, the interference a is set to 0.08 to 0.16 mm and the compression ratio is set to 10 to 20% with respect to the maximum thickness b of the elastic member 84 = 0.8 mm.
[0024]
Next, the operation of the clutch device of the hydraulic transmission will be described.
[0025]
Operation oil is supplied to or recovered from the hydraulic chamber 7 through an oil supply passage 17 provided in the small cylinder portion 12 of the housing 1. By controlling the supply and recovery of the operation oil, the piston is controlled. 2 is slid to the right or left in FIG. By this sliding operation, the clutch plate 51 disposed at the end of the large cylindrical portion 23 of the piston 2 is brought into a pressed state or a separated state with respect to the clutch disk 52 so that power is transmitted or power is interrupted. Has become.
[0026]
As described above, in this embodiment, the elastic member for sealing the inner peripheral surface of the small tube portion 32 of the support plate 3 between the small tube portion 32 and the small tube portion 12 of the housing 1. 84 is attached. In this case, unlike the conventional example, there is no need to provide a circumferential groove for installing an O-ring in the axial direction of the fitting portion between the support plate 3 and the housing 1, so that the axial dimension of the fitting portion is not required. Can be shortened, and the size of the clutch device can be reduced. Further, the labor for machining the circumferential groove can be saved, and the O-ring mounting step which requires accurate and careful work is not required, so that the manufacturing cost can be reduced.
[0027]
Note that the present invention is not limited to the above-described embodiment, but can be applied to the embodiments described below.
[0028]
(1) Embodiment 2 is shown in FIG. In the second embodiment, the small cylindrical portion 32 on the inner peripheral edge of the annular plate portion 31 of the support plate 3 is omitted. Then, the elastic member 85 is attached to the inner peripheral edge of the annular plate portion 31.
[0029]
The elastic member 85 is attached to the inner peripheral edge of the annular plate portion 31 of the support plate 3 from the inner diameter side to the hydraulic chamber side, and has a predetermined interference between the small cylindrical portion 12 of the housing 1 in the radial direction. Compressed while holding.
[0030]
In this case, in addition to the operation and effect of the first embodiment, since the small cylindrical portion 32 is not provided on the inner peripheral edge of the annular plate portion 31 of the support plate 3, the axial dimension of the clutch device can be further reduced accordingly.
[0031]
Further, as shown in FIG. 4, a lip 87 may be integrally attached to the elastic member 85. In this case, the lip 87 is compressed with a predetermined radial interference with the outer peripheral surface of the small cylindrical portion 12 of the housing 1.
[0032]
(2) Embodiment 3 is shown in FIG. In the third embodiment, in addition to the configuration of the first embodiment, an elastic member 86 is also attached to the inner peripheral surface of the small cylindrical portion 22 of the piston 2.
[0033]
The attachment form and shape of the elastic member 86 are the same as those of the elastic member 84 attached to the small tubular portion 32 of the support plate 3.
[0034]
In this case, in addition to the functions and effects of the first embodiment, the small cylinder portion 22 of the piston 2 can be further shortened in the axial direction, so that the clutch device can be further reduced in size.
[0035]
【The invention's effect】
As described above, in the clutch device for a hydraulic transmission according to the present invention, the operation oil is prevented from leaking or abrasion powder infiltrating along the fitting surface between the housing and the support plate. The axial dimension of the fitting surface between the housing and the support plate can be reduced. Therefore, the size of the device can be reduced while ensuring the sealing performance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a clutch device according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view illustrating a main part of FIG. 1; FIG. FIG. 4 is a sectional view of a main part of a clutch device according to a second embodiment of the present invention; FIG. 5 is a sectional view of a clutch device according to a third embodiment of the present invention; FIG. 6 is a sectional view showing a conventional clutch device; Explanation of code]
DESCRIPTION OF SYMBOLS 1 Housing 2 Piston 3 Support plate 4 Reverse spring 7 Hydraulic chamber 12 Small cylinder part 32 Small cylinder part 84 Elastic member

Claims (2)

A housing that forms an annular space by connecting one axial side of the large cylindrical portion and the small cylindrical portion that are concentrically arranged with an annular wall portion,
A piston that is slidably housed in the annular space so that the inner peripheral surface of the large cylinder portion and the outer peripheral surface of the small cylinder portion can be slid in the axial direction and forms a hydraulic chamber between the opposed surfaces of the annular wall portion; ,
A support plate that is externally mounted so as to be slidable only in a direction approaching the annular wall portion, at a position axially separated from the annular wall portion on the outer peripheral surface of the small cylinder portion by a predetermined distance,
A reverse spring that is interposed between the support plate and the piston in a state where the piston is compressed in the axial direction and presses the piston toward the annular wall by elastic restoring force;
A clutch device for a hydraulic transmission, wherein an elastic member that seals a fitting surface between the support plate and the small cylinder portion is integrally attached to an inner periphery of the support plate. The clutch device for a hydraulic transmission according to claim 1, wherein an elastic member that seals a fitting surface between the piston and the small cylinder portion is integrally attached to an inner periphery of the piston.

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