JPH045412Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial application field The invention consists of a cylinder body and a cylinder body that is slidably fitted into a cylinder hole of the cylinder body to define a hydraulic chamber in the cylinder hole. A relief port valve for a master cylinder, which is composed of a piston and a replenishment oil chamber that communicates with an oil tank in the cylinder hole by the intermediate part of the piston, and is configured such that the hydraulic chamber and the replenishment oil chamber communicate with each other. A poppet valve that can open and close a relief port drilled in the piston, a valve spring that biases the poppet valve in the closing direction, and a through hole that passes through the middle part of the piston in the horizontal direction are loosely fitted to A fixed bearing that has a valve opening rod that faces the poppet valve to open the poppet valve at the retraction limit, and a pair of supporting holes that support both ends of the valve opening rod, and that slidably supports the rear part of the piston. This invention relates to an improvement in a stopper ring that is attached to a piston to limit the retraction limit of the piston by coming into contact with the piston, and a separation spring that is interposed between the stopper ring and the piston and biases them in the direction of separation.

(2) Prior Art This type of relief port valve has already been proposed by the present applicant (see Utility Model Application No. 62-32922).

(3) Problems to be solved by the invention In the relief port valves that have already been proposed, in order to prevent the valve-opening rod from coming out of the stopper ring, a coil spring whose inner circumferential surface faces opposite ends of the valve-opening rod is attached to the stopper ring. Although the coil spring is wound around an annular groove on the outer periphery, the coil spring is a small part and installation work is extremely troublesome.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide the above-mentioned relief port valve that is easy to assemble and has a simple structure.

B. Structure of the device (1) Means for solving the problem In order to achieve the above object, the present invention includes a cylindrical portion whose inner circumferential surface faces both ends of the valve opening rod, and a cylindrical portion that stands up from the rear end of the cylindrical portion. A retainer having a flange for receiving the rear end of the separation spring is fitted around the outer periphery of the stopper ring. It is characterized by a retaining claw.

(2) Effect According to the above configuration, the retainer is held in the stopper ring without play by the contact of the rear end of the elastic locking claw with the rear side wall of the annular groove and the repulsive force exerted on the flange of the separation spring. This retainer performs two functions: preventing the valve opening rod from coming off the stopper ring, and serving as a seat for the separation spring.

Furthermore, when assembling this retainer, it is simply fitted to the outer periphery of the stopper ring together with the separation spring from the rear end side, and the elastic locking pawl can be engaged with the annular groove of the stopper ring by its elasticity. .

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. The master cylinder M shown in FIG. 1 is a tandem type master cylinder for a two-system hydraulic brake of an automobile. A front piston 2 ₁ and a rear piston 2 ₂ are provided in the cylinder hole 1a.
are slid together in series, a front hydraulic chamber 3 ₁ is defined between the front piston 2 ₁ and the front end wall of the cylinder 1a, and a rear hydraulic chamber 3 ₂ is defined between both pistons 2 ₁ and 2 ₂ . Two brake hydraulic circuits are connected to output ports 4 ₁ and 4 ₂ connected to the hydraulic chambers 3 ₁ and 3 ₂ , respectively.

Each piston 2 ₁ , 2 ₂ is provided with a cup seal 5 ₁ , 5 ₂ that is in close contact with the cylinder hole 1a, and the intermediate portion of each piston 2 1 , 2 2 has front and rear supply oil chambers 6 ₁ , 6 ₂ in the cylinder hole 1a. It has a small diameter to define the area. Oil holes 7 that communicate these supply oil chambers 6 ₁ , 6 ₂ with the backs of the cup seals 5 ₁ , 5 _2
1 and 7 ₂ are drilled into each piston 2 ₁ and 2 ₂ .

The front hydraulic chamber 3 ₁ includes a return spring 8 ₁ that urges the front piston 2 ₁ in the backward direction, and both pistons 2 ₁ ,
_{A return spring 8 2 is} provided between each of the pistons 2 2 to urge the rear piston 2 ₂ in the backward direction.

At the top of the cylinder body 1, there is a front oil supply chamber _61.
A cylindrical auxiliary oil tank 9 is integrally provided adjacent to the auxiliary oil tank 9, and a main oil tank 10 made of synthetic resin is fitted into the upper end of the auxiliary oil tank 9 and connected thereto.

Inside the auxiliary oil tank 9 is a bulkhead 1 that is integrated with the cylinder body 1.
1 into front and rear oil reservoir chambers 9 ₁ and 9 ₂ , and the front oil reservoir chamber 9 ₁ is connected to the front supply oil chamber 6 ₁ through a through hole 12 ₁ penetrating its bottom wall. The front replenishment oil chamber 6 ₁ communicates with a through hole 13 ₁ that passes laterally through the middle part of the front piston 2 ₁ , and this through hole 13 ₁ .
It communicates with the front hydraulic chamber 3 1 through the center of the piston 2 ₁ and through a relief port 14 ₁ that opens to the valve seat 19 ₁ on the front surface of the piston 2 ₁ . The through hole 13 ₁ is
The long diameter is longer than the sliding stroke of the front piston 2 ₁ and is oriented in the axial direction of the front piston 2 ₁ .

A conventional relief port valve V ₁ is provided in the front piston 2 ₁ to open and close said relief port 14 ₁ . This relief port valve V ₁ is composed of a valve case 15 ₁ , a poppet valve 16 ₁ , a valve spring 17 ₁ and a valve opening rod 18 ₁ .

The valve case 15 ₁ has a cup shape and is fitted onto the front end of the front piston 2 ₁ via a seal member 20 ₁ .

The poppet _valve 16 ₁ consists of a rubber umbrella part 21 ₁ and a valve rod _{22 2 that} supports the umbrella part 21 ₁ . ₁ is arranged so as to be loosely inserted into the relief port ₁₄₁ .

The valve spring 17 ₁ is attached to the valve case 15 ₁ so as to bias the poppet valve 16 ₁ toward the valve seat 19 ₁ , that is, in the valve closing direction.

The valve opening rod 18 ₁ is connected to the through hole 13 ₁ of the front piston 2 ₁
The poppet valve 16 1 is fixed to the cylinder body 1 through the rear end of the valve rod 22 ₁ so as to receive the rear end of the valve rod 22 ₁ so as to open the poppet valve 16 ₁ at the retraction limit of the front piston 2 1 .

On the other hand, the rear oil reservoir chamber 9 ₂ communicates with the rear replenishment oil chamber 6 ₂ via a through hole 12 ₂ passing through the upper wall of the cylinder body 1, and the rear replenishment oil chamber 6 ₂ also communicates with the rear piston 2 _{2 .} A through hole 13 ₂ that passes through the middle part of the
and communicates with the rear hydraulic chamber 3 ₂ via a relief port 14 ₂ that passes through the center of the rear piston 2 ₂ and opens into a valve seat 19 ₂ on the front surface thereof.

The rear piston ₂₂ consists of a piston part 24 fitted with the cup seal ₅₂ , and a rod part 25 connected to the rear end of the piston part 24. The rod portion 25 has a bearing 2 fitted to the rear end of the cylinder body 1 concentrically with the cylinder hole 1a.
7 through a seal member 28, and its rear end is connected to an output rod of a booster (not shown). The through hole ₁₃₂ is bored in this rod portion.

A relief port valve V ₂ of the present invention is installed on the rear piston 2 ₂ to open and close the relief port 14 ₂ .

As shown in FIGS. 2 and 3, this relief port valve V ₂ has a valve case 15 ₂ and a poppet valve 16.
₂ , valve spring 17 ₂ , valve opening rod 18 ₂ , stopper ring 29,
It is composed of a retainer 31 and a separation spring 32.

The valve case 15 ₂ has a cup shape and is fitted onto the front end of the rear piston 2 ₂ via a seal member 20 ₂ .

The poppet valve 16 ₂ consists of a rubber umbrella part 21 ₂ and a valve rod 22 ₂ that supports the umbrella part 21 ₂ , with the umbrella part 21 ₂ facing the valve seat 19 ₂ and the valve rod 22 ₂ . is arranged so as to be loosely inserted into the relief port ₁₄₂ .

The valve spring 17 ₂ connects the poppet valve 16 ₂ to the valve seat 19 ₂
The valve case _{152 is attached to the valve case 152} so as to be biased toward the valve closing direction.

The valve opening rod 18 ₂ is the valve rod 22 ₂ of the poppet valve 16 ₂
It is loosely inserted into the through hole 13 ₂ of the rear piston 2 ₂ so that the rear end can be pushed or moved away from them.

The stopper ring 29 is made of synthetic resin and is slidably fitted to the rod portion 25 in front of the bearing 27, and contacts the front end of the bearing 27 to receive the piston portion 24, thereby stopping the rear piston ₂₂ . The retraction limit can be regulated. This stopper ring 29 has a pair of supporting holes 33 that support both ends of the valve opening rod ₁₈₂ .
33 are provided.

The retainer 31 is made of steel pipe and has support holes 33, 3.
A cylindrical portion 31a is fitted to the outer periphery of the stopper ring 29 so that the inner periphery thereof faces both ends of the valve opening rod ₁₈₂ fitted to the valve opening rod 182, and a flange 31b stands up from the rear end of the cylindrical portion 31a. The cylindrical portion 31a has a plurality of elastic locking claws 34, 3 cut and raised so as to extend rearward and radially inward.
4... are provided at equal intervals in the circumferential direction, and these are engaged with an annular groove 35 on the outer peripheral surface of the stopper ring 29.

The separation spring 32 is compressed between the piston portion 24 and the flange 31b so as to surround the cylindrical portion 31a. The separation spring 32 applies an elastic force in the separation direction to the piston portion 24 and the stopper ring 29 via the retainer 31, and its set load is set to be weaker than that of the return spring ₈₂ . Therefore, the separation spring 32 does not in any way impede the backward movement of the rear piston 2 ₂ by the return spring 8 ₂ .

Next, the operation of this embodiment will be explained.

When assembling the relief port valve V ₂ , first attach the poppet valve 16 ₂ and the valve spring 17 ₂ to the piston portion 24.
and the valve box 15 ₂ , and then fit the stopper ring 29 into the rod portion _{25 and insert the valve opening rod 18 2 into} the support holes 33 , 33 and the through hole 13 ₂ .
Align both end surfaces of the stopper ring 29 with the outer peripheral surface of the stopper ring 29.
After this, when the retainer 31 and the separation spring 32 are fitted into the stopper ring 29 from the rear end side, the locking claws 34, 34... group are elastically deformed in the radial direction until they reach the annular groove 35 of the stopper ring 29. It slides on the outer circumferential surface of the stopper ring 29, and when it reaches the annular groove 35, it contracts in diameter due to its own elasticity and engages with each groove 35. At this stage, the separation spring 32 is attached to the piston portion 24.
and flange 31b, and a set load is applied.

In this way, the retainer 31 has the locking claws 34, 34
... It is held in the stopper ring 29 without play by the contact of the rear end of the group with the rear side wall of the annular groove 35 and the repulsive force exerted on the flange 31b of the separation spring 32. Further, it can have two functions: to prevent the valve opening rod 18 ₂ from coming off, and to serve as a seat for the separation spring 32.

When the rear piston 2 ₂ is at the backward limit, the second
As shown in the figure, the separation spring 32 is moved between the piston portion 24 and the flange 31b by the return force of the return spring ₈₂ .
The stopper ring 29 is compressed between the piston portion 24
and the bearing 27, and accordingly the valve opening rod 1
8 ₂ is fixed. The rear end of the poppet valve 16 ₂ is received by the valve opening rod 18 ₂ so that the poppet valve 16 2 is in an open state.

Now, if the rear piston ₂₂ is moved forward by the operation of a booster (not shown), the separation spring 32 will initially be moved forward.
resists the adhesive force of the hydraulic oil interposed between the contact surfaces of the piston portion 24 and the stopper ring 29.
4 and 29 and move the stopper ring 29 to the bearing 2.
7, thereby opening the through hole 13.
Movement of the valve opening rod 18 ₂ is prevented within the range of play at ₂ .

Therefore, at the same time as the rear piston ₂₂ moves forward, the poppet valve ₁₆₂ is released from the valve opening rod ₁₈₂ and moved to the seating position with the valve seat ₁₉₂ by the valve spring ₁₇₂ , that is, the valve closing position, and the relief port 14 ₂ can be closed. When the poppet valve ₁₆₂ closes,
As the rear piston ₂₂ continues to move forward, the rear wall of the through hole ₁₃₂ comes into contact with the valve opening rod ₁₈₂ , so that the valve opening rod 1
8 ₂ , rear piston 2 ₂ with stopper ring 29 etc.
moves forward.

This forward movement of the rear piston 2 ₂ generates hydraulic pressure in the rear hydraulic chamber 3 ₂ , and this hydraulic pressure is output from the output port 4 ₂ to operate the corresponding wheel brake.

On the other hand, the front piston 2 ₁ moves forward in response to the forward force of the rear piston 2 ₂ applied to the return spring 8 ₂ and the hydraulic pressure generated in the rear hydraulic chamber 3 ₂ , and accordingly the poppet valve 16 ₁ opens. The valve stem 18 ₁ is released, the valve spring 17 ₁ moves the valve to the closed position, and the relief port 14 ₁ is closed, so that as the front piston 2 ₁ continues to move forward, hydraulic pressure is generated in the front hydraulic chamber 3 ₁ .
The oil pressure is outputted from the output port ₄₁ to operate the corresponding wheel brake. During this time, the valve opening rod 18
₁ moves relatively within the through hole 13 ₁ and does not hinder the forward movement of the front piston 2 ₁ .

If the booster is deactivated, both pistons 2 ₁ ,
2 ₂ is returned to a predetermined retraction limit by the return force of each return spring 8 ₁ , 8 ₂ , and in the return process, the hydraulic chambers 3 ₁ ,
3 ₂ is depressurized, the outer periphery of the cup seals 5 ₁ and 5 ₂ bends forward due to the pressure difference between the front and rear, creating a gap between the inner surface of the cylinder hole 1a and the gap between each piston 2 ₁ and 2 ₂ . Hydraulic oil is supplied from the supply oil chambers 6 ₁ , _{6 2 to} the hydraulic chambers 3 ₁ , 3 2 _through the oil holes 7 1 , 7 ₂ . At that time, if excessive replenishment is performed, the excess oil is supplied to the replenishing oil through the relief ports 14 ₁ , 14 ₂ which are opened by the poppet valves 16 ₁ , 16 ₂ when each piston 2 ₁ , 2 ₂ returns to the retraction limit. room 6
_1,6 Returned to ₂ .

C. Effect of the invention As described above, according to the invention, a cylindrical part whose inner peripheral surface faces both ends of the valve opening rod, and a flange that stands up from the rear end of this cylindrical part and receives the rear end of the separation spring. Fitting the retainer having the retainer around the outer periphery of the stopper ring,
This retainer is provided with an elastic locking pawl that extends rearward and radially inward and engages with an annular groove on the outer periphery of the stopper ring, so that when the retainer is fitted to the stopper ring on the rear end side with a release spring, With an extremely simple operation, you can simultaneously prevent the valve opening rod from coming out of the stopper ring and set the separation spring.
It is extremely easy to assemble, and since one retainer has the dual functions of preventing the valve opening rod from coming out and serving as a seat for the separation spring, the structure is simple and can contribute to cost reduction.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional side view of a tandem type master cylinder, and FIG.
The figure is an enlarged view of the main part of the relief port valve of the present invention in the master cylinder, and FIG. 3 is an exploded perspective view of the main part. M...Master cylinder, _V2 ...Relief port valve, 1...Cylinder body, 1a...Cylinder hole, 2 ₂ ...Piston, 3 ₂ ...Hydraulic chamber, 6 ₂ ...
Supply oil chamber, 13 ₂ ... Through hole, 14 ₂ ... Relief port, 15 ₂ ... Valve box, 16 ₂ ... Poppet valve, 1
7 ₂ ... Valve spring, 18 ₂ ... Valve opening rod, 27 ... Bearing, 29 ... Stopper ring, 31 ... Retainer, 3
1a... Cylindrical part, 31b... Flange, 32...
Separation spring, 33... Strut hole, 34... Elastic locking claw,
35...Annular groove.

Claims (1)

[Scope of utility model registration request] It consists of a cylinder body and a piston that is slidably fitted into a cylinder hole of the cylinder body to define a hydraulic chamber in the cylinder hole, and the supply oil is communicated with the oil tank in the cylinder hole through the intermediate part of the piston. A relief port valve of a master cylinder defining a chamber, and a poppet valve that can open and close a relief port bored in a piston so as to communicate between a hydraulic chamber and a replenishment oil chamber, and a poppet valve that can open and close the relief port that is formed in a piston so as to communicate between a hydraulic chamber and a replenishment oil chamber. a valve spring that biases the valve; and a valve opening rod that is loosely fitted into a through hole that passes through the intermediate portion of the piston in the lateral direction and faces the poppet valve in order to open the poppet valve at the retraction limit of the piston.
It has a pair of support holes that support both ends of this valve opening rod,
A stopper ring is attached to the piston to limit the retraction limit of the piston by coming into contact with a fixed bearing that slidably supports the rear part of the piston, and a stopper ring is interposed between the stopper ring and the piston to move the two apart. A retainer comprising a cylindrical part whose inner circumferential surface faces both ends of the valve opening rod, and a flange that stands up from the rear end of the cylindrical part and receives the rear end of the separation spring. A relief for a master cylinder, which is fitted onto the outer periphery of a stopper ring, and the retainer is provided with an elastic locking pawl that extends rearward and radially inward and engages with an annular groove on the outer periphery of the stopper ring. Port valve.