KR20020007503A - Structure of piston of clutch release cylinder for car - Google Patents

Abstract

PURPOSE: Piston structure of a clutch release cylinder for a vehicle is provided to prevent oil leakage and lowering of hydraulic pressure in the release cylinder by restricting a parting line in a mold with making a piston of synthetic resin, and to improve strength against tension of a spring by modifying the structure. CONSTITUTION: A piston is supported elastically by a return spring(42) in a cylinder, and divided into a piston body(41a) and a return spring supporting part(43). The spring supporting part and the piston body are manufactured individually, and combined integrally by an assembling unit. The assembling unit consists of an assembling protrusion(44) formed in the inner periphery of the spring supporting part, and an assembling groove(45) formed in the outer periphery of the piston body. The piston body is combined with the spring supporting part by inserting the assembling protrusion to the assembling groove, and by pressing elastic grooves(41c) with the inner periphery of the spring supporting part. The parting line of a mold is eliminated, and burr is not formed in the cup installation surface of the piston body with manufacturing the spring supporting part and the piston body individually. Oil leakage, lowering of hydraulic pressure and the breakage of the piston are prevented with improving the strength against tension of the spring by modifying the structure.

Description

Structure of piston of clutch release cylinder for car

The present invention relates to a clutch release cylinder for an automobile, and more particularly, to a piston installed in a clutch release cylinder for operating a release fork while being loaded along a cylinder by hydraulic pressure.

In general, the clutch (cluch) is a device that is installed between the engine and the transmission to perform power transmission and power cut, divided into a friction clutch, a fluid clutch, a power clutch, an electromagnetic clutch, etc., the operation mechanism for operating such a clutch Mechanical and hydraulic controls with levers and cables are used.

On the other hand, commonly used hydraulic operation mechanisms include a clutch pedal (1), a clutch master cylinder (2), a hydraulic pipe and connecting hose (3), a clutch release cylinder (cluch release cylinder) 4, and the like. It is composed.

When the clutch pedal 1 is depressed from such a configuration, the pedal force is transmitted to the piston of the clutch master cylinder 4 via the push rod, and hydraulic pressure is formed in the pressure chamber of the clutch master cylinder by the compression force of the piston.

This hydraulic pressure acts on the piston of the clutch release cylinder 4 via the hydraulic pipe and the connecting hose 3, and the operating rod installed on the piston operates the release fork 5 to separate the clutch pressure plate (not shown). .

On the other hand, when the foot is released from the clutch pedal 1, the clutch pressure plate returns to its original position by the tension of the clutch pressure spring.

On the other hand, the clutch release cylinder (hereinafter referred to as "release cylinder") 4, which is one of the clutch operating mechanisms, is connected to the master cylinder 2 by a hydraulic pipe and a connection hose 3, as shown in FIG. A cylinder body 40, a piston 41 installed in the cylinder body and operated by hydraulic pressure introduced from the master cylinder 2, a return spring 42 for elastically supporting the piston, and the return piston and release It consists of a working rod 43 for connecting the fork (5).

Accordingly, when the clutch pedal 1 is pressed, hydraulic pressure is generated in the master cylinder 2 due to the stepping force, and the hydraulic pressure is transmitted to the release cylinder 4 through the hydraulic pipe and the connection hose 3, and the release cylinder body. The piston 41 installed in the 40 is pushed in the direction of the release fork 5, and the release fork 5 connected to the piston 41 by the operating rod 43 also flows in the same direction as the piston 41. do.

On the other hand, the piston 41 is returned to the initial position by the tension of the return spring 42 which elastically supports the piston 41 with the foot from the clutch pedal 1.

The piston 41 material of the release cylinder 4, which plays such a role, has previously used aluminum (Al) whose surface has been polished by anodizing.

For reference, anodizing refers to a treatment method in which a metal is placed on an anode side in an electrolyte and a current is passed through an inert metal as a cathode in cleaning, polishing, or oxidizing a metal surface.

However, since the piston 41 made of aluminum is not only expensive but has to go through a multi-stage work process, the piston 41 has not only lowered productivity but also increased the price of the product.

In recent years, a product was developed in which the material of the piston 41 was replaced with a synthetic resin (plastic). This product has a moderate strength and low cost, and is easy to manufacture. .

However, as the tension of the return spring 42 is continuously acting on the support jaw 40a formed integrally on the outer circumferential surface of the cylinder body 40 such that the piston 41 of the synthetic resin material is also supported by the return spring 42. In case of long-term use, the load is concentrated to the part and it has been a cause of crack or breakage.

On the other hand, the center of the body of the conventional piston 41 is provided with an installation groove 400 for the cup 410 (CUP) installation along the longitudinal direction of the body.

At this time, the cup 410 is made of a flexible material such as EPDM in the form of a ring, and serves to prevent the leakage of oil and to generate a hydraulic pressure.

On the other hand, the conventional piston 41 is injection molded in one piece (piece), due to the parting line of the mold (not shown) after molding the burr (burr) along the longitudinal direction of the piston 41 outer surface Is formed.

At this time, when the burr formed on the outer surface of the piston 41 is not completely removed, a burr occurs between the cup 410 outer peripheral surface of the piston 41 and the cup 410 due to the burr. Oil leakage in the pressure chamber will occur.

Therefore, the burr on the surface of the piston 41 must be machined and removed.

However, it takes a lot of time and cost to remove the burr on the surface of the piston 41, there was a problem that the workability is degraded during machining.

That is, in the related art, the piston 41 has a problem in that it takes a lot of time and money due to the unevenness (자) in the shape itself and to remove the burrs manually by hand.

In particular, the burr located in the groove portion in which the cup 410 for generating hydraulic pressure and preventing oil leakage is difficult to be removed. Accordingly, the burr is not properly removed, causing oil leakage and pressure drop in the master cylinder as described above. There was a very high concern.

The present invention has been made to solve the above-mentioned conventional problems, the object of which is to improve the corresponding strength of the piston to the tension of the return spring in the release cylinder.

On the other hand, another object of the present invention is to prevent the oil leakage and the hydraulic pressure drop in the release cylinder by preventing the parting line in the mold portion corresponding to the cup installation surface during the design and manufacture of the mold.

In order to achieve the above object, the present invention provides a piston of an automobile clutch release cylinder in which a piston elastically installed by a return spring in a cylinder is divided into two parts, and the divided parts are joined by a coupling means to integrate the piston.

1 is a schematic configuration diagram of a clutch and its operating system

Figure 2 is a longitudinal sectional view showing a schematic configuration of a conventional clutch release cylinder

Figure 3 is a perspective view showing a separate piston of the clutch release cylinder according to the present invention

4 is a longitudinal cross-sectional view of FIG.

5 is a longitudinal cross-sectional view of the coupled state of FIG.

* Explanation of symbols for main parts of the drawings

41a: piston body 41b: hollow portion

41c: elastic groove 42: return spring

43: spring support 44: engaging projection

45: coupling groove 46: support protrusion

46a: support surface

Figure 3 is a perspective view showing the piston of the clutch release cylinder according to the present invention separately, Figure 4 is a longitudinal cross-sectional view of Figure 3, Figure 5 is a longitudinal cross-sectional view of the engaged state of Figure 4, with reference to these accompanying drawings of the present invention The piston structure of the vehicle clutch release cylinder will be described in detail as follows.

In the present invention, as shown in Figs. 4 and 5, the spring support portion 43, which is a portion in which the return spring 42 is supported in the release cylinder 4, and the remaining portion of the piston body 41a are separately manufactured, and these are combined. It is an improvement to the structure integrated by combining by means.

The coupling means includes a coupling protrusion 44 formed on one of the coupling surfaces of the piston body 41a and the spring support 43, and a coupling groove formed on the opposite surface to insert the coupling protrusions 44 into each other. 45).

That is, although the coupling groove 45 is formed in one outer peripheral surface of the piston body 41a and the coupling protrusion 44 is formed in the inner peripheral surface of the spring support 43 in FIGS. 4 and 5, the coupling means is opposite. Of course, it is provided that may be coupled by force indentation.

On the other hand, the formation position of the coupling groove 45 in the above is more preferably formed along the outer peripheral surface of the piston body (41a), because the thickness of the spring support 43 is not so thick coupling groove 45 in this portion This is because the strength of the spring support itself may be weakened if it is formed.

In addition, the piston 41 is improved by the tension of the return spring by improving the surface facing the centerline of the piston body 41a in the coupling protrusion 44 to have a shape that opposes the tension of the return spring 42. To prevent damage.

As described above, the shape against the tension of the return spring 42 is a surface facing the center line of the piston body 41a of the coupling protrusion 44 and the surface of the coupling groove 45 in contact therewith. Is a gradient angle in the direction opposite to the tension direction acting on the piston body (41a) from the return spring (42).

Accordingly, it is possible to prevent the piston 41 including the piston body 41a and the spring support 43 from being damaged by improving the force against the tension of the return spring 42.

In addition, a support protrusion 46 is formed on the outer circumferential surface of the spring support 43 to directly contact the return spring 42. The support surface 46a supporting the return spring 42 is supported by the support protrusion 46. Is inclined at right angles to the inclination angle of the return spring of cone type (see FIG. 5).

Accordingly, the tension of the return spring 42 acts perpendicularly to the support surface 46a of the support protrusion 46 to improve the strength of the support protrusion 46 against the return spring 42.

In addition, a hollow portion 41b is formed at a coupling portion of the piston body 41a with the spring support 43, and a plurality of coupling portions are elastically compressed in the centerline direction of the piston body around the hollow portion 41b. The elastic groove 41c was formed.

The elastic groove 41c is formed for easy coupling as it is elastically compressed at the time of coupling the piston body 41a and the spring support 43.

Meanwhile, in the present invention, the parting line of the mold is eliminated by separately manufacturing the spring support 43 and the remaining piston body 41a, which are parts of the release cylinder 4, on which the return spring 42 is supported. It is comprised so that a burr may not be formed on the cup installation surface of the piston body 41a.

Referring to the operation of the present invention having such a configuration as follows.

The piston 41 is divided into a spring support 43 for supporting the piston body 41a and the return spring 42, but when it is coupled to the spring by the coupling groove 45 formed on one outer peripheral surface of the piston body 41a. As the coupling protrusion 44 formed on the inner circumferential surface of the support 43 is inserted, the coupling force between the two members can be obtained.

Then, the hollow portion 41b is formed at the engaging portion with the spring support 43 of the piston body 41a, and the engaging portion is elastically compressed in the centerline direction of the piston body 41a around the hollow portion 41b. The plurality of elastic grooves 41c were formed as much as possible.

Accordingly, when the spring support 43 is inserted into the piston body 41a, the elastic groove 41c is elastically contracted while being pressed by the inner circumferential surface of the spring support 43 so that the two members can be easily coupled. .

If there is no elastic groove (41c), when the spring support 43 is inserted into the outer circumferential surface of the piston body (41a) can not be forced to fit, there is a difficulty in the coupling operation.

In addition, the surface facing the center line of the piston body 41a of the coupling protrusion 44 and the surface of the coupling groove 45 in contact therewith are gradientd in the reaction force direction of the tension of the return spring 42, which is the return spring 42. Even though the tension of) acts on the spring support 43 and the piston body 41a, it is possible to prevent the damage caused by the spring tension by having a structural strength corresponding thereto.

The reason why such a coupling structure is required is that the return spring 42 has a cone shape, and thus the spring tension acts at an angle to the cone shape, thereby corresponding to the structure.

In addition, the support surface 46a which is formed on the outer circumferential surface of the spring support part 43 and contacts the return spring in the support protrusion 46 supporting the return spring 42 has an appropriate gradient so as to be perpendicular to the inclination of the return spring 42. Since the spring tension acting on the piston 41 can be made uniform according to the angle, it is possible to improve the accuracy of the component operation associated with it.

In addition, since the spring tension direction and the corresponding direction of the support protrusion 46 coincide, the corresponding strength of the support protrusion can be improved.

Then, the hollow portion 41b is formed at the engaging portion with the spring support 43 of the piston body 41a, and the engaging portion is elastically compressed in the centerline direction of the piston body 41a around the hollow portion 41b. The plurality of elastic grooves 41c were formed as much as possible.

Accordingly, when the spring support 43 is inserted into the piston body 41a, the elastic groove 41c is elastically contracted while being pressed by the inner circumferential surface of the spring support 43 so that the two members can be easily coupled. .

Unlike in the above embodiment, the piston 41 is divided into a spring support 43 for supporting the piston body 41a and the return spring 42, but does not form the engaging projection 44 and the engaging groove 45. Instead, the piston body 41a may be made of a harder material than the spring supporter 43, and the piston body 41a may be forced into the spring supporter 43 to allow the two members to be coupled together.

On the other hand, in the present invention, since the spring support 43 and the remaining portion of the piston body 41a are manufactured separately, the mold located on the cup installation surface of the piston body 41a can be pulled back.

Therefore, in the present invention, the mold corresponding to the cup installation surface side of the piston body 41a can be formed in one piece, whereby the parting line of the mold is eliminated, and thus the cup installation surface of the piston body 41a. No burr is formed on the phase.

As described above, in the structure in which the piston of the release cylinder is changed from aluminum to synthetic resin, the piston is divided into a piston body and a spring support and improved to a reinforcement structure to withstand the spring tension. It is possible to exhibit the effect of preventing damage by.

Thus, the side effect of extending the life of the piston to improve the reliability of the product can also be obtained.

In addition, according to the present invention, since no parting line is formed in the mold part corresponding to the cup installation surface during the design and manufacture of the metal mold, no Ever occurs on the cup installation surface of the piston body, thereby effectively preventing oil leakage and hydraulic pressure drop. It becomes possible.

Claims (6)

A clutch clutch release cylinder for a vehicle in which a piston is elastically supported by a return spring in the cylinder; A piston structure of an automobile clutch release cylinder in which said piston is separated into a piston body and a return spring support portion on which a return spring is supported, and these are integrated by a coupling means. The method of claim 1, Joining means, A coupling protrusion formed on any one surface of the piston body and the return spring support unit coupled thereto; Piston structure of the clutch release cylinder for a vehicle consisting of a coupling groove formed so that the coupling projection is inserted into the opposite surface formed with the coupling projection. The method according to claim 1 or 2, A piston structure of a clutch release cylinder for an automobile in which the engaging projection has a surface facing the center line of the piston body and a surface of the engaging groove in contact therewith with a draft angle parallel to the reverse direction of the tension direction acting on the piston body from the return spring. The method of claim 1, Piston structure of the clutch master cylinder for automobiles formed in the return spring support so that the support surface is perpendicular to the inclination angle of the return spring. The method of claim 1, The piston structure of the clutch release cylinder for automobiles is made of synthetic resin. The method of claim 1, A piston structure of an automobile clutch release cylinder having a plurality of elastic grooves formed in the coupling portion with the spring support of the piston body, and the coupling portion is elastically compressed in the direction of the center line of the piston body.