JPH0445970Y2 - - Google Patents

Description

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

[Conventional technology]

A conventional master cylinder valve device of this type is disclosed in Japanese Utility Model Application Laid-Open No. 59-184260. This valve device connects fluid operated equipment (brake device) from the pressure chamber of the master cylinder into the chamber of the valve body.
A one-way valve member equipped with a valve port that only allows fluid to flow toward the fluid-operated device;
A one-way valve member can be seated on a valve seat formed at the chamber-side end of the outlet, and the opening is communicated with an opening connected to the pressure chamber only when the one-way valve member is separated from the valve seat. The one-way valve member is connected to a valve spring in order to prevent the residual pressure function from working during air purge work performed prior to filling hydraulic fluid into the brake system. A support member is provided that locks the valve seat so as to move it away from the valve seat against the urging force of the valve seat. This support member has a shaft portion that passes through the one-way valve member, and a truncated conical locking portion is formed at the tip of the shaft portion, over which the lip portion of the valve port of the one-way valve member can ride. The one-way valve member is locked by the locking portion.

When vacuum-filling the brake system of a brake system with brake fluid on a factory automatic assembly line, the first step is to suck the air in the brake system from the reservoir opening of the master cylinder using a vacuum pump. When vacuum is drawn from the master cylinder side,
Since the one-way valve member is separated from the valve seat,
Through the communication passage, air from the wheel cylinder side of the brake system quickly flows to the master cylinder side, and the air within the brake system is extracted in a short time until a sufficient vacuum state is achieved.

Once the air in the brake system has been sufficiently removed, hydraulic fluid is pumped into the brake system from the reservoir opening of the master cylinder.The pressure of the hydraulic fluid acts on the one-way valve member, and this fluid pressure causes the one-way valve to close. The member moves over the locking portion and seats on the valve seat, and the valve port is pushed open to force the hydraulic fluid to the end of the wheel cylinder.

[Problem that the invention attempts to solve]

In this way, in the conventional valve device described above, the one-way valve member is locked to the support member until the hydraulic fluid is force-fed from the master cylinder side to the brake system side.
The inlet and outlet of the valve body are communicated to block the residual pressure function from working, and the blocking of the residual pressure function is released by pressurizing the hydraulic fluid, but one-way valves The shaft portion of the support member passes through the lip portion of the valve port of the member,
Since the lip portion slides on the shaft portion during assembly or during the recovery operation of the residual pressure function, there is a problem in that the lip portion may be damaged and the sealing performance may be impaired.

The present invention has been made to solve the above problem, and allows the valve body to be seated without sliding on the member that holds the valve body in a position separated from the valve seat when positive pressure is applied. An object of the present invention is to provide a valve device for a master cylinder.

[Means for solving problems]

In order to achieve the above object, the present invention has a holding member that is movable between a forced open position where the valve body is removed from the valve seat and a normal use position where the valve body is placed on and removed from the valve seat. a base part having an annular shape surrounding a seating part for the valve seat and capable of contacting the valve body from the outlet side; and a base part formed on the base part to force the holding member against the biasing force of the valve spring. and a leg portion that retains the holding member in the open position and displaces the holding member from the forced open position to the normal use position when a predetermined positive pressure is applied to the valve body from the inlet side, and then locks the holding member in the normal use position. It's a thing.

[Effect]

In the present invention, when a predetermined positive pressure is applied to the valve body from the inlet side, the valve body exerts a pushing force on the holding member and moves together with the holding member to the seating position, and as in the conventional case, the valve body moves against the supporting member. Since it does not move relative to the material placement position, there is no damage to the seal portion due to sliding.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a cylinder body of a master cylinder, which integrally has a valve body part 3 extending from a cylinder bottom wall 2, and the tip of the valve body 3 is screwed into the tip. It is closed by a fitted valve cover 4, and a valve chamber 5 is defined between the valve cover 4 and the cylinder bottom wall 2. The valve chamber 5 communicates with a pressure chamber 7 defined within the cylinder body 1 by a piston (not shown) through a through hole (inlet of the valve device) 6 formed in the cylinder bottom wall 2. The valve cover 4 has a connection port (outlet of the valve device) 8 to which a pipe (not shown) is connected, and communicates with a wheel cylinder of a brake device (not shown) through the pipe. This valve lid 4 has a block portion 9 that is reduced in diameter and projects into the valve chamber 5.
On the outer periphery of the tip of the block portion 9, a flange-shaped engagement portion 10 with a tapered circumferential surface that expands in diameter from the tip toward the rear is formed, and a circumferential protrusion is formed at a position slightly away from the engagement portion 10. A locking portion 11 having a shape is formed, and a valve hole 12 communicating with the outlet 8 is provided therethrough.

Numeral 13 is a leg-shaped member (hereinafter referred to as leg-shaped member in the description of the embodiment) made of synthetic resin as a holding member, and as shown in FIGS. An annular pedestal 14 having a large outer diameter smaller than the inner diameter inside the valve body 3, and this pedestal 14.
It has a shape consisting of three legs 15 of a predetermined length that protrude from the inner periphery of the back surface at predetermined intervals in the circumferential direction, and the tips of the legs 15 have claws 1 that protrude inwardly.
6 is formed, this leg-like member 13 has a leg portion 1
The tapered surface of the pawl 16 of No. 5 is connected to the engaging portion 1 of the block portion 9.
engaged with the tapered surface of 0 and disposed within the valve chamber 5,
The valve body 17 is received on the surface of the base portion 14. This valve body 17 is made up of a base plate 18 and a rubber-like elastic body 19 that covers part of the side and bottom surfaces of the base plate 18, and the valve cover 4 side openings of the two small holes 18a penetrating the base plate 18 are covered with elastic body 19. A lip portion 19a around the valve port 20 of the body 19 is closed to form a check valve.
19b is a seat portion formed to protrude so as to surround the valve port 20. This valve body 17 has one end connected to the cylinder bottom wall 2.
The valve spring 21 engaged with the valve spring 21 urges the leg-like member 13 toward the leg-like member 13 and presses against the base 14 of the leg-like member 13. separated by a certain distance. Note that the engagement force between the claw 16 of the leg portion 15 of the leg member 13 and the engagement portion 10 of the block portion 9 is greater than the pushing force from the valve spring 21 received via the valve body 17, and a predetermined liquid The engagement between the two is not released until pressure is applied.

A case will be described in which the vacuum is drawn as described above before the brake system of a vehicle brake system to which this valve device is attached is vacuum-filled with hydraulic fluid. In the illustrated state, the opening of the valve hole 12 on the valve chamber 5 side is open, and between the legs 15, between the base 14 and the inner peripheral surface of the valve body 3, and between the valve body 17 and the valve body 3. It communicates with the inlet 6 through the communication passage 22 which is formed between the valve cover 4, the valve hole 12 and the communication passage when the vacuum is drawn. 22, flows rapidly through the inlet 6 into the pressure chamber 7 of the cylinder body 1;
The air within the brake system is sufficiently sucked in a short period of time, creating a sufficient vacuum state within the brake system. When this evacuation is completed, the hydraulic fluid is pumped from the reservoir opening (not shown) of the master cylinder. When the hydraulic fluid is pumped, the hydraulic pressure of the hydraulic fluid acts on the valve body 17, and this hydraulic pressure causes the valve body to 17 is pressed toward the valve lid 4 side and exerts a pressing force on the leg member 13,
This pressing force causes the claws 16 of the leg portions 15 of the leg-shaped member 13 to
moves over the tapered surface of the engaging portion 10.
The leg member 13 moves until the seat portion 19b of the valve body 17 is seated on the end surface of the block portion 9, and at this time, the claw 1
6 is locked to the locking part 11. In this way, the hydraulic fluid urges the valve body 17 toward the valve cover 4, and also presses the valve port 2.
Push open the lip part 19a of 0 to open the small hole 18a,
It flows out from the valve port 20, the valve hole 12, and the outlet 8 into a pipe (not shown), and is pumped through the pipe to the end of the wheel cylinder. When the valve body 17 is seated on the end face of the block portion 9, the communication passage 22 is blocked, and a residual pressure function is established.
is locked by the block part 9 in a state where it fits into the outside of the block part 9.

Next, the operation when the brake is applied will be explained.

When hydraulic pressure is generated in the pressure chamber 7 of the cylinder body 1 by depressing a brake pedal (not shown), this hydraulic pressure flows into the valve chamber 5 from the inlet 6 and acts on the valve body 17. When the valve body 17 is seated on the valve seat, the communication path 22 that communicates the inlet 6 and the valve hole 12 is blocked, but since hydraulic pressure acts on the lip portion 19a through the small hole 18a, the lip portion 19a is closed. The hydraulic fluid is forced to expand and flows from the valve port 20 through the valve hole 12 to the pipe from the outlet 8, and is fed to the wheel cylinder. This causes the wheel cylinder to operate and apply braking force to the wheels of the vehicle.

When the brake pedal is released, the hydraulic pressure in the pressure chamber 7 decreases, but the valve spring 21
While the hydraulic pressure on the wheel cylinder side is higher than the force applied by the biasing force of to bias. As a result, the communication path 2
2 opens, the valve hole 12 and the inlet 6 communicate through the communication passage 22, and the working fluid from the wheel cylinder side flows to the master cylinder side. After that, the hydraulic pressure on the wheel cylinder side decreases, and the hydraulic pressure is applied to the valve spring 21.
When the pressure drops below the predetermined pressure set by
The valve body 17 moves toward the valve hole 12 side by the biasing force of the valve spring 21 and seats on the end face of the block portion 9, and the inlet 6
and exit 8. As a result, a constant residual pressure set by the valve spring 21 is maintained in the brake system on the wheel cylinder side, which prevents paper lock from occurring in the brake system and air from entering. I can do it.

In this way, in this embodiment, the leg-like member 13 is used as a member for preventing the residual pressure function from working, and the valve body 17 is simply made to face the leg-like member 13. 17 receives a predetermined pressure (positive pressure from the inlet 6 side), it does not move relative to the leg-shaped members 13 but moves together with the leg-shaped members 13 and sits down. There is no sliding, and therefore, the valve body 17 is not damaged by the leg-like members 13. Furthermore, by arranging the leg member 13 radially outward from the seat portion 19b of the valve body 17, the pawl 16 of the leg portion 15 is once locked in the locking portion 11, and then supplied to the outlet 8 side. Even if the hydraulic pressure acts to separate the seat portion 19b of the valve body 17 from the end face of the block portion 9 when the hydraulic pressure is released to the inlet 6 side, the leg-shaped member 13 is not affected by the hydraulic pressure. Since it is not subjected to any force, it will not return to the state shown in Figure 1.

In addition, in the above embodiment, the leg-like member 13 is connected to the valve lid 4.
Although the valve body 17 is taperedly engaged with the valve body 17, the engagement structure between the two may be such that the engagement is released when the valve body 17 receives a predetermined positive pressure.

[Effect of idea]

As explained above, the present invention uses a holding member as a means for keeping the communication path communicating between the inlet and the outlet open until a predetermined operating pressure is applied from the pressure source. The open state is maintained simply by pressing the valve body, and the open state is released without sliding on the holding member, so when setting the valve body or releasing the open state, , it is possible to prevent the sealing portion from being adversely affected. In addition, since the holding member is arranged to surround the seating portion of the valve seat on the valve body, once the valve body is displaced to a position where it can be seated and removed from the valve seat, it returns from the outlet side to the inlet side. The valve device is not returned to the position where the valve is kept open due to hydraulic pressure, and the intended function of the valve device is not inhibited.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2a is a plan view of the leg-shaped member in the above embodiment,
Figure b is a side view of the leg-shaped member. 1... Cylinder body, 4... Valve lid, 5... Valve chamber, 6... Inlet, 7... Pressure chamber, 8... Outlet, 1
2... Valve hole, 13... Leg-shaped member (holding member), 1
4... Base part, 15... Leg part, 17... Valve body, 19
...Elastic body constituting the check valve, 19b... Seat part,
21...Valve spring.

Claims (1)

[Scope of utility model registration request] an inlet connected to the pressure chamber of the master cylinder;
an outlet connected to a brake device, a valve hole formed in communication with the inlet and the outlet, a valve seat formed on the outlet side of the valve hole, and biased by a valve spring to be seated on the valve seat. a check valve formed on the valve body that allows liquid to move from the inlet side to the outlet side when seated on the valve seat; and a forced open position that causes the valve body to leave the valve seat. and a holding member that is displaced to a normal use position that allows the valve body to be seated and removed from the valve seat, wherein the holding member is a seating portion of the valve body with respect to the valve seat. a pedestal portion having an annular shape surrounding the valve body and capable of abutting the valve body from the outlet side; a pedestal portion formed on the pedestal portion to resist the biasing force of the valve spring and retain the holding member in the forcibly opened position; A master cylinder valve device comprising a leg portion that displaces the holding member from the forced open position to the normal use position when a predetermined positive pressure is applied to the valve body from the inlet side, and then locks the holding member in the normal use position.