JP2762180B2 - Poppet valve for master cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a poppet valve for a master cylinder which opens and closes a relief port of a master cylinder used for operating a hydraulic clutch or brake of an automobile, and more particularly, to a poppet valve formed at one end of a valve rod. In the umbrella body,
The present invention relates to an improvement of an umbrella portion formed by joining a seal member capable of sitting on a valve seat facing a hydraulic chamber of a master cylinder.

[0002]

2. Description of the Related Art Such a poppet valve is disclosed in
It is already known as disclosed in JP-A-39167.

[0003]

In the poppet valve disclosed in the above publication, an umbrella portion is formed by molding and joining an elastic seal member to an umbrella portion main body connected to a valve rod so as to cover the entire outer peripheral surface thereof. Therefore, every time the pressure in the hydraulic chamber facing the umbrella portion increases, the elastic seal member receives a high oil pressure on its entire outer peripheral surface and generates a large distortion, and the repetition deteriorates the durability of the seal member. There are drawbacks.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide the master cylinder poppet valve having high durability while avoiding distortion of the seal member due to high hydraulic pressure.

[0005]

In order to achieve the above object, the present invention provides an umbrella body having an annular groove opening at an end surface of the umbrella body, and an annular groove extending from the outer peripheral surface of the umbrella body to the annular groove. 1
An anchor hole, and a second anchor hole traversing the core of the umbrella body surrounded by the annular groove, wherein both anchor holes are annular grooves.
The annular groove and the first and second anchor holes are filled with and joined to the seal member, and the annular groove and the first and second anchor holes are joined together .
The sealing member has a valve protruding from the end face of the umbrella body.
It is characterized in that a seal ridge that can be brought into and away from the seat is formed .

[0006]

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

In FIG. 1 and FIG.
1 shows a tandem master cylinder for a systematic hydraulic brake, in which a cylinder body 1 is mounted on the front surface of a booster shell Bs of a negative pressure booster B. This cylinder body 1
A front piston 2f and a rear piston 2r are fitted in series in the cylinder hole 1a, a front hydraulic chamber 3f is provided between the front piston 2f and the front end wall of the cylinder hole 1a, and a rear hydraulic chamber is provided between the pistons 2f and 2r. Each of the hydraulic chambers 3r is defined.
Then, two brake hydraulic circuits are connected to the output ports 4f, 4r of the two hydraulic chambers 3f, 3r.

The rear piston 2r contacts the front end surface of the bearing 5 fitted to the rear end of the cylinder hole 1a to restrict the retreat limit of the piston 2r;
The piston rod 2b is slidably supported on the output rod Bo of the negative pressure booster B.
Are connected.

Each of the pistons 2f and 2r has a cylinder bore 1a.
The cup seals 5f and 5r are in close contact with each other, and the intermediate portions thereof have small diameters so as to define front and rear supply oil chambers 6f and 6r in the cylinder hole 1a. Oil holes 7f, 7r are formed in each of the pistons 2f, 2r to connect the supply oil chambers 6f, 6r to the back surfaces of the cup seals 5f, 5r.

A front return spring 8f for urging the front piston 2f in the backward direction is provided in the front hydraulic chamber 3f, and a rear return spring for urging the rear piston 2r in the backward direction between the two pistons 2f and 2r. 8r are respectively contracted.

A cylindrical auxiliary oil tank 9 is integrally connected to the upper part of the cylinder body 1 adjacent to the front supply oil chamber 6f.
A main oil tank 10 made of synthetic resin is fitted and connected to the upper end.

The inside of the auxiliary oil tank 9 is divided into front and rear oil reservoirs 9f and 9r by a partition 11 integral with the cylinder body 1, and the front oil reservoir 9f has a through hole 12f penetrating the bottom wall thereof.
The front replenishment oil chamber 6f communicates with the front replenishment oil chamber 6f via an elongate hole 13f which traverses an intermediate portion of the front piston 2f and a central portion of the front piston 2f extending from the elongate hole 13f. Through the relief port 14f that opens to the valve seat 20 on the front surface of the front hydraulic chamber 3f. The long hole 13f is provided with a longer diameter than the sliding stroke of the front piston 2f toward the axial direction of the piston 2f.

Relief port 14f of front piston 2f
A front relief port valve Vf is provided on the front piston 2f to open and close the valve. This relief port valve Vf
Valve box 15, poppet valve 16, valve spring 17 and valve-opening rod 18
Consists of

The valve box 15 has a cup shape having a through hole 19 in the peripheral wall, and is fitted to the front end of the front piston 2f.

The poppet valve 16 comprises an umbrella portion 16a and a valve rod 16b for supporting the umbrella portion 16a. The umbrella portion 16a is opposed to the valve seat 20 on the front face of the front piston 2f. The valve rod 16b is loosely inserted into the relief port 14f.

The valve spring 17 is housed in the valve box 15 so as to urge the poppet valve 16 toward the valve seat 20, that is, in the valve closing direction.

The valve-opening rod 18 is a long hole 1 of the front piston 2f.
3 and is fixed to the cylinder body 1 so as to open the poppet valve 16 at the retreat limit of the front piston 2f.
6b is adapted to receive the rear end.

On the other hand, the rear oil reservoir 9r communicates with the rear oil supply chamber 6r through a through hole 12r passing through the upper wall of the cylinder body 1, and the rear oil supply chamber 6r is connected to an intermediate portion of the rear piston 2r. It communicates with the rear hydraulic chamber 3r via a transverse through hole 13r and a relief port 14r opening from the center of the rear piston 2r to the valve seat 21 on the front surface.

A rear relief port valve Vr is provided on the rear piston 2r for opening and closing the relief port 14r. As shown in FIG. 3, the rear relief port valve Vr includes a valve box 25, a poppet valve 26, a valve spring 27, and a retainer 28 as a valve opening member.

The valve box 25 has a cup shape having a through hole 29 in the peripheral wall and a guide hole 30 in the end wall.
r is fitted to the front end.

The poppet valve 26 comprises an umbrella portion 26a and a valve rod 26b for supporting the umbrella portion.
An enlarged portion 33 is formed at the front end of. And umbrella part 26a
Is accommodated in the valve box 25 so as to face the valve seat 21 on the front surface of the rear piston 2r, and the valve rod 26b is loosely inserted into the guide hole 30.

The valve spring 27 is housed in the valve box 25 so as to bias the poppet valve 26 toward the valve seat 21, that is, in the valve closing direction.

The retainer 28 has a guide hole 34 at the center thereof, into which the valve rod 26b is loosely inserted, and is prevented from being pulled out by the enlarged portion 33. The rear return spring 8r is contracted between the retainer 28 and the valve box 25. A larger set load is applied to the rear return spring 8r than to the front return spring 8f.

The retainer 28 is fitted to the rear end of the rear piston 2r, while the enlarged portion 33 is slidably fitted in a bag-shaped center hole 35 opened in the rear end surface of the piston 2r.

The structure of the umbrella portion 26a of the poppet valve 26 will be described with reference to FIGS.

As shown in FIGS. 3 and 4, the umbrella 26a
Is composed of an umbrella body 40 integral with the valve rod 26b, and a seal member 41 joined to the umbrella body 40. The umbrella body 40 has a shallow circular recess 42 at its end face, and a deep annular groove 43 that opens along the periphery of the recess 42, and further reaches the annular groove 43 from the outer peripheral surface of the umbrella body 40. One or a plurality of first anchor holes 44 and a core 4 of the umbrella body 40 surrounded by the annular groove 43
One or a plurality of second anchor holes 45 crossing Oa are formed. The first and second anchor holes 44, 45
Are formed all at once by drilling, are arranged on a coaxial line , and are formed near the bottom of the annular groove 43 (see FIG. 5). The rubber seal member 4 is inserted into the recess 42, the annular groove 43, and the first and second anchor holes 44 and 45.
1 is filled and baked. At this time, the sealing member 41 projects from the end face of the umbrella section main body 40 to the valve seats 20 and 21.
An annular seal ridge 41a that can be brought into contact with the ring is formed.

In molding such a seal member 41, first, as shown in FIG.
The umbrella body 40 of the poppet valve 26 is installed in the cavity 48 formed on the opposing surfaces of
The first part of the umbrella part body 40 is attached to the runner 49 formed on the facing surface of
Align the anchor holes 44. Thereafter, a rubber serving as the seal member 41 is injected from the runner 49 into the first anchor hole 44, and the rubber is injected into the second anchor hole 45, the annular groove 43, and the concave portion 42.
And baking.

The umbrella portion 16a of the poppet valve 16 in the front relief port valve Vf also has the same structure as the umbrella portion 26a of the poppet valve 26, as shown in FIG. The same reference numerals are given to the portions corresponding to and the detailed description of the structure is omitted.

Next, the operation of this embodiment will be described.

When the negative pressure booster B is at rest, the front piston 2f is caused to retain the retainer 2 by the elastic force of the front return spring 8f.
8 and is held at the retreat limit in contact with the rear piston 2r.
Is held at the retreat limit contacting the bearing 24 by the elastic force of the rear return spring 8r. In this case, since the set load of the return spring 8r is set to be larger than that of the front return spring 8f as described above, the rear return spring 8r moves the poppet valve 26 to the position where the poppet valve 26 is fully opened. The retainer 34 is pressed forward together with the front piston 2f against the force. The fully opened position of the poppet valve 26 is
The front end surface 32 a is regulated by contacting the peripheral edge of the guide hole 30 of the valve box 25.

On the other hand, at the retreat limit of the front piston 2f, the valve-opening rod 18 receives the valve rod 16b of the poppet valve 16 and holds the valve 16 in the open position.

When the negative pressure booster B is operated from such a state and the rear piston 2r is advanced by the output rod Bo, first, the front piston 2r is moved via the rear return spring 8r.
is advanced to compress the front return spring 8f.

According to the forward movement of the front piston 2f, first, at the front relief port valve Vf, the poppet valve 16 is separated from the valve-opening rod 18 and simultaneously seated on the valve seat 20 by the force of the valve spring 17. Since the relief port 14f is closed, hydraulic pressure is generated in the front hydraulic chamber 3f as the front piston 2f continues to advance, and the hydraulic pressure is supplied from the output port 4f to the corresponding wheel brake.

When hydraulic pressure is generated in the front hydraulic chamber 3f,
As the rear piston 2r advances, the compression of the rear return spring 8r starts. Then, first, at the rear relief port valve Vr, the poppet valve 26 is released from the retainer 34 and a valve closing operation is given from the valve spring 27, so that the seal ridge 41a of the seal member 41 is seated on the valve seat 21. The relief port 14r is closed. When the rear relief port valve Vr is closed in this way, a hydraulic pressure is generated in the rear hydraulic chamber 3r by the subsequent forward movement of the rear piston 2r, and the hydraulic pressure is supplied from the output port 4r to the corresponding wheel brake. During this time, the enlarged portion 33 of the valve rod 26b slides forward through the center hole 35 of the front piston 2f, and thus does not hinder the forward movement of the rear piston 2f.

When the pressure in the front and rear hydraulic chambers 3f, 3r is increased, the sealing ridges 41a of the sealing members 41 of the poppet valves 16, 26 correspond to the corresponding valve seats 20 by the hydraulic pressure acting on the front surfaces of the umbrella sections 16a, 26a. , 21 so as to more securely close the relief ports 14f, 14r. The seal member 41 is disposed near the concave portion 42 and the annular groove 43 of the umbrella portion main body 40 and near the bottom of the groove 43.
Since the first and second anchor holes 44 and 45 are filled and baked, the bonding strength with the umbrella body 40 is strong, and the first anchor hole 44 opened on the outer peripheral surface of the umbrella body 40 crosses. Since the seal member 41 has only a very small area and receives only the oil pressure of the hydraulic chambers 3f and 3r through the first anchor hole 44, the distortion of the seal member 41 caused by the seal member 41 is extremely small.

Next, if the operation of the negative pressure booster B is released,
Both pistons 2f, 2r are returned to the predetermined retreat limit by the force of the respective return springs 8f, 8r, and during the retreat process, the hydraulic chambers 3f, 3r
When the pressure is reduced, the outer peripheral portions of the cup seals 5f and 5r bend forward due to a pressure difference between the front and rear thereof to form a gap between the inner surface of the cylinder hole 1a and the gap and each of the pistons 2f and 2r.
The working oil is supplied from the supply oil chambers 6f, 6r to the hydraulic chambers 3f, 3r through the oil holes 7f, 7r. If the hydraulic oil is excessively replenished at that time, when each piston 2f, 2r returns to the retreat limit, the excess amount is supplied to the replenishing oil chambers 6f, 6r through the relief ports 14f, 14r opened by the poppet valves 16, 26. Returned to

[0037]

As described above, according to the present invention, an annular groove opening on the end surface of the umbrella portion main body, a first anchor hole reaching the annular groove from the outer peripheral surface of the umbrella portion main body, A second anchor hole that traverses the core of the umbrella body surrounded by the annular groove is formed by positioning both anchor holes near the bottom of the annular groove.
The annular groove and the first and second anchor holes are filled and joined with the sealing member.
A seal projection that protrudes from the end surface of the umbrella body and can come and go with the valve seat
Due to the formation of the ridge, the annular groove and the first and second anchor holes effectively increase the bonding strength of the sealing member to the umbrella body , and the sealing member by the hydraulic pressure applied to the outer peripheral surface of the umbrella part. Can be effectively prevented, thereby improving the durability of the seal member. And especially both
By making the anchor hole near the bottom of the annular groove, the sealing member
So that the corresponding portion of the anchor hole is also offset toward the bottom of the annular groove.
And project the anchor hole corresponding portion from the end surface of the umbrella portion main body.
Since it can be separated as much as possible from the seal ridge, the anchor hole
Minimize the effect of the corresponding part on the elasticity of the seal ridge.
And always have good elasticity over the entire seal ridge.
The anchor hole can be specially provided.
The closing performance of the poppet valve is not affected.
No.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a master cylinder embodying the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a longitudinally enlarged side view of a main part of a poppet valve of the rear relief port valve in FIG.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a longitudinal sectional enlarged side view of a main part of the poppet valve before a seal member is baked.

FIG. 6 is an explanatory diagram of a molding method of a seal member of the poppet valve.

FIG. 7 is a longitudinally enlarged side view of a main part of the poppet valve of the front relief port valve in FIG.

[Explanation of symbols]

 3f, 3r Hydraulic chamber 16 Poppet valve 16a Head part 16b Valve rod 20, 21 Valve seat 26 Poppet valve 26a Head part 26b Valve rod 40 Head part main body 41 Seal member 43 Annular groove 44, 45 First and second anchor holes M master Cylinder

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60T 11/16-11/21 F16K 1/32-1/46

Claims (1)

(57) [Claims] 1. A valve seat (20, 21) facing a hydraulic chamber (3f, 3r) of a master cylinder (M) on an umbrella body (40) formed at one end of a valve rod (16b, 26b). Umbrella sections (16a, 26)
a) the poppet valve for a master cylinder, wherein the umbrella body (40) is provided with an annular groove (43) opening at an end surface of the umbrella body, and an annular groove (4) extending from the outer peripheral surface of the umbrella body.
First anchor hole reaching 3) (44), and the core portion of the bevel portion body which is surrounded by an annular groove (43) (the second anchor hole traversing 40a) (45), the two anchor holes ( 4
4, 45) are located near the bottom of the annular groove (43).
The annular groove (43) and the first and second anchor holes (44, 45) are filled and joined with the sealing member (41). The sealing member (41) has the umbrella body (4).
0) can protrude from the end face and come into contact with or separate from the valve seat (20, 21).
Characterized in that a sealing ridge (41a) is formed .
Poppet valve for master cylinder.