JPH0410142Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a master cylinder used in a clutch or brake device of a vehicle or the like.

[Conventional technology]

Conventionally, as a master cylinder whose cylinder body is formed using a synthetic resin material, for example,
There is one described in Publication No. 59-49082.

In this master cylinder, a union sheet is inserted into the stepped hole of the piping connection part in which the threaded member that serves as the piping connection aid is integrally molded, and the union sheet is used to seal between the cylinder body and the piping connection part. This is done by a sealing member fitted between the cylinder body and the piping is sealed by pressing the end of the piping against a union sheet.

[The problem that the idea aims to solve]

With this seal structure, there is a risk of liquid leakage due to peeling at the mating surface between the threaded member and the resin side, so the above sealing member is essential.
In addition, the union sheet cannot be omitted because it requires a means for transmitting and supporting the tightening force for fixing the piping to the threaded member.Therefore, the number of parts is large, and the sealing member is Since it has to be inserted and placed deep inside the housing, assembly work is troublesome, costs are high, and productivity is poor.

Furthermore, there are three sealed locations: between the cylinder body and the sealing member, between the sealing member and the union seat, and between the union seat and the piping.As there are many sealed locations, hydraulic pressure is generated when the master cylinder operates. This increases the possibility of liquid leakage from the sealed area due to poor sealing.

In addition, the cylinder body formed from the constituent resin material deforms due to repeated stress and thermal history, so
If pressure or heat history is repeatedly applied between the union sheet fitted with the sealing member and the cylinder body,
There was also the problem that the gap between the union sheet and the cylinder body was widened, and the force pressing against the sealing member was weakened, resulting in poor sealing between the cylinder body and the sealing member, which could result in liquid leakage.

This invention was devised to solve the above problems.The number of parts required for piping connection is small, and the piping connection work is simple and easy. To provide a master cylinder which has a low possibility of liquid leakage from a sealed part due to the leakage and which does not cause sealing failure even if a cylinder body is deformed.

[Means to solve the problem]

In order to achieve the above object, the present invention divides a pressure chamber by slidably inserting a piston into a cylinder hole of a cylinder body formed from a synthetic resin material, and divides the hydraulic fluid reservoir and pressure chamber according to the movement of the piston. The communication is cut off to generate liquid pressure in the pressure chamber, which is communicated with the pressure chamber and can be discharged from the piping connection part provided in the cylinder body.In addition, the piping connection part is made with an inner hole when the cylinder body is molded. The formed auxiliary device is integrally buried, and the inner hole of the auxiliary device has a protrusion whose inner diameter is reduced toward the pressure chamber side, and the end of the pipe is crimped on the outside toward the protrusion. In the master cylinder, each having a threaded surface onto which a piping fixture is screwed, a cylindrical portion extending from the pressure chamber side of the cylinder body into the inner hole of the auxiliary tool, and an end of this cylindrical portion. An annular protrusion that is continuous with the inner surface of the protrusion of the auxiliary tool and has an enlarged diameter in a tupular shape so that the end can be press-contacted to the end of the piping. The structure is such that it is formed simultaneously and integrally with the cylinder body when it is buried in the body.

[Effect]

In the present invention, the protruding end of the piping protruding from the piping fixture is press-fitted around the entire circumference with the lug-shaped inner surface of the end of the annular protrusion, and both are compressed by the protrusion of the auxiliary tool and the piping fixture. , the piping connection structure is such that the entire circumference of the annular protrusion is in pressure contact with each other and the entire outer circumference of the end portion of the annular protrusion is in pressure contact with the protrusion of the auxiliary tool.

[Embodiment] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a master cylinder embodying the present invention, and FIGS. 2 and 3 show enlarged structures of the piping connections.

In each figure, reference numeral 1 denotes a cylinder body of a master cylinder, which is made of synthetic resin material and has a cylinder hole 2 that is open at one end. Reference numeral 3 denotes a hydraulic fluid reservoir, the main body of which is integrally formed with the cylinder body 1 and communicates with the cylinder hole 2 through a through hole 4 formed in the peripheral wall of the cylinder body 1. 5 is a synthetic resin lid of the hydraulic fluid reservoir 3, and 6 is a seal ring. 7 is a piston, as shown in FIG. 4, it has a plate-shaped space 8 that penetrates in the radial direction and expands in the axial direction;
It is slidably inserted into the cylinder hole 2 from the open end side, and a pressure chamber A is defined at the closed end side of the cylinder hole 2. On the open end side of the cylinder hole 2, a rod seat member 10 is integrally fitted to the end 9 of the piston 7 with a lip-type sealing member 11 interposed therebetween, which fits around the outer periphery of the end 9.
12 is a boot, and 13 is an operating rod.

Reference numeral 14 denotes a shaft member, which has a threaded portion on one end side, is inserted radially into the cylinder hole 2 from the peripheral wall of the cylinder body 1, penetrates the plate-shaped space 8, and is inserted radially into the cylinder hole 2. It is inserted into a hole 15 that penetrates the plate-like space 8 and opens into the hydraulic fluid reservoir 3 in the peripheral wall of the cylinder body 1, and is fixed to the cylinder body 1 by the threaded portion. Reference numeral 16 denotes a valve plunger, which has a valve portion 16A at the tip end of the shaft, and the rear end of the shaft portion loosely fits the head 17 of the piston 7 in the axial direction, and extends and abuts and engages with the shaft member 14. . The head 17 has a stepped portion 17A on the circumferential surface on one end surface side for receiving a cap-shaped spring receiver 18.
The piston 7 is pressed rearward by a return spring 19 via the piston 7. A valve spring 20 is interposed between the spring receiver 18 and the valve portion 16A.

In FIGS. 2 and 3, reference numeral 30 denotes a piping connection part, which includes a cylindrical part (boss part) 32 having a hole 31 opening on the outer end side, and a cylinder body arranged concentrically with the hole 31 in the hole 31. It has an annular protrusion 33 having an end 33A that protrudes from the first side and expands into a bulging shape, and is formed integrally with the cylinder body 1 on the pressure chamber A side of the cylinder body 1. This annular protrusion 3
3 has a through hole 34, which communicates with the pressure chamber A and the hole 31. Reference numeral 35 denotes an auxiliary tool having an inner hole 36, which is provided during the above-mentioned integral molding, is inscribed in the hole 31 and fixedly held by the flange 35A, and has an annular shape inside one end of the inner hole 36. An end portion 33A of the protrusion 33 protrudes. A protrusion 38 is formed at one end of the inner hole 36 and protrudes inward from the hole by forming a flap-shaped surface 37 that is press-fitted with the flap-shaped outer surface of the annular projection 33. has a threaded surface. Numeral 39 is a piping fixture, which has a hole 40 through which a piping 41 can be passed tightly.

To explain the procedure for connecting the piping 41, the piping fixture 39 is inserted onto the piping 41 in advance, the end of the piping 41 is processed to form the protruding end 42, and the piping fixture 39 is rotated by the auxiliary tool 35. Screw in until it stops. As the tightening rotation of the piping fixture 39 progresses,
The protruding end portion 42 of the pipe 41 protruding from the pipe fixture 39 is press-fitted and engaged with the above-mentioned latch-shaped inner surface of the end portion 33A of the annular protrusion 33 over the entire circumference, and both of them are connected to the auxiliary tool 35.
The end 3 of the annular protrusion 33 is pinched by the protrusion 38 and the piping fixture 39, and is in pressure contact with each other around the entire circumference.
The entire outer circumference of 3A comes into pressure contact with the protrusion 38.

To briefly explain the operation of this master cylinder, when the clutch pedal (not shown) is depressed,
The actuating rod 13 is driven to the left in the figure.
As a result, the piston 7 moves in the same direction against the elasticity of the return spring 19, and the movement of the piston 7 drives the head 17 toward the valve portion 16A, and the head 17 moves toward the valve portion 16A.
6A is seated on the valve seat of the valve head, the pressure chamber A and the hydraulic fluid reservoir 3 are cut off, and hydraulic pressure is generated in the pressure chamber A. The generated hydraulic pressure is discharged from the piping connection 30 and supplied to the clutch operating cylinder through the piping 41.

In this embodiment, the protruding end portion 42 of the pipe 41 is pressed against the wrapper-shaped inner surface of the end portion 33A of the annular protrusion 33 over the entire circumference, so that the cylinder body 1 and the pipe 41
, that is, between the cylinder body 1 and the piping connection part 3
0 and the end 33A of the annular protrusion 33.
The outer surface portion of is pressed against the protrusion 38. In addition, although the union sheet described above is not used, the annular protrusion 33
The end portion 33A supports the pipe 41 and transmits the tightening force.

In this way, since the annular protrusion 33 serves as both the sealing member and the union sheet, the number of parts can be reduced.

Furthermore, there is only one sealed location between the end 33A of the annular protrusion 33 and the protruding end 42 of the pipe 41, and when the master cylinder is operated, hydraulic pressure is generated in the through hole 34 and the pipe 41. There is also a low possibility of liquid leakage due to poor sealing, and since the annular protrusion 33 is integrated with the cylinder body 1, poor sealing will not occur even if the cylinder body 1 is deformed due to repeated pressure or heat history.

Furthermore, in this embodiment, when the temperature changes, the auxiliary tool 39
Even if a difference in deformation occurs between the cylinder body 1 and the annular protrusion 33 due to the difference in thermal expansion coefficient, the pressure chamber A is No liquid leaks from the annular protrusion 33, and the sealing performance is always stable.

Note that the annular protrusion 33 can be formed by only partially changing the molded shape of the cylinder mold.

Further, in order to enhance the sealing effect of the end portion 33A of the annular protrusion 33 and improve its durability, it is preferable to form the end portion 33A as thin as possible to reduce the amount of deformation.

[Effect of idea]

As explained above, the present invention has an annular protrusion that is integrally formed with the cylinder body and that can be press-contacted with the end of the piping on the inner surface and can be press-contacted with the inner circumferential surface of the auxiliary tool on the entire outer circumference, and protrudes into the piping connection part. As a result, there is no need to use sealing members or union sheets as in the past, which reduces the number of parts and makes piping connection work simpler and easier than before. , reduce the price,
Productivity can be improved.

Furthermore, since there is only one sealed location, even if fluid pressure is generated when the master cylinder is activated, there is less chance of fluid leaking from the sealed location due to poor sealing, and there is less chance of fluid leaking from the sealed location due to repeated stress or thermal history. Even if the cylinder body is deformed by the piping, a sealing failure will not occur, and even if there is a difference in the amount of deformation between the auxiliary tool, the cylinder body, and the annular protrusion due to the difference in the coefficient of thermal expansion, the piping end and the auxiliary From between the protrusion of the tool to the pressure chamber,
Since no liquid leaks from the annular protrusion, stable and good sealing performance can always be ensured.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention;
The figure is an enlarged sectional view of the pipe connection part in the above embodiment, FIG. 3 is a plan view of the pipe connection part in the above embodiment, and FIG. 4 is a perspective view of the piston in the above embodiment. 1...Cylinder body, 2...Cylinder hole, 7...
... Piston, 30 ... Piping connection part, 32 ... Boss part, 33 ... Annular protrusion, 33A ... End part, 34 ...
...Through hole, 35...Auxiliary tool, 36...Inner hole, 39...
...Piping fixture, 41...Piping, 42...Protruding end.

Claims (1)

[Claim for Utility Model Registration] A piston is slidably inserted into a cylinder hole of a cylinder body formed from a synthetic resin material to partition a pressure chamber, and the hydraulic fluid reservoir and the pressure chamber communicate with each other according to the movement of the piston. The liquid pressure is generated in the pressure chamber by shutting off the liquid pressure, and it is communicated with the pressure chamber and can be discharged from the piping connection part provided in the cylinder body.In addition, an inner hole is formed in the piping connection part when the cylinder body is molded. An auxiliary tool is integrally buried, and the inner hole of the auxiliary tool has a protrusion with a reduced inner diameter on the pressure chamber side, and a piping fixing device that crimps the end of the piping toward the protrusion on the outside side. In the master cylinder, each having a threaded surface onto which the tool is screwed, a cylindrical portion extending from the pressure chamber side of the cylinder body into the inner hole of the auxiliary tool, and an end of this cylindrical portion are provided. An annular protrusion that is connected to the cylinder body of the auxiliary tool and has an end that has a diameter enlarged in a tupular shape so that the end can be pressed against the end of the piping by covering the inner surface of the protrusion of the auxiliary tool. The master cylinder is formed simultaneously and integrally with the cylinder body when it is buried.