JPH07300066A - Proportioning valve - Google Patents

Abstract

PURPOSE:To prevent a valve from interfering with a piston of a master cylinder to eliminate generating an abnormal sound and further to improve reliability of brake operation by improving assembly workability of a spring, pressing the valve, and forming workability of a valve retainer. CONSTITUTION:A valve retainer 23 is provided in an opening end part of a valve body 16 mounted in a housing 2a of a master cylinder 2, and a valve 32, pressed to a side of a plunger 25 by a pressing spring 30 to come into contact with and to separate from a valve seat 31, is arranged in the valve retainer 23.1 In a proportioning valve 1 formed 4 to shaft part of the valve 32 in order to protrude in a cylinder 4 to place the valve 32 in an opened condition by a flange 13a of a tubular member 13 fitted to a piston 6 according to an excessive moving distance of the piston 6 of the master cylinder 2, an engaging piece 34, bent after the valve 32 and the pressing spring 30 are inserted to be arranged, is provided in a point end part of the valve retainer 23, to arrange the engaging piece 34 engageably with the valve 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proportioning valve attached to a master cylinder.

[0002]

2. Description of the Related Art Conventionally, a proportioning valve of this type has been arranged in the middle of a hydraulic passage from a master cylinder to a rear wheel brake cylinder. Then, as shown in FIG. 5, the proportioning valve applies the same braking force to the rear wheels as the front wheels when the braking force is low at the beginning of braking,
When the braking force exceeds a predetermined value (actuation start point A in the figure), a smaller braking force is applied to the rear wheels at a predetermined ratio than the front wheels, thereby preventing rear wheel lock and ensuring stable braking. Is configured to obtain.

More specifically, as shown in FIG. 6, the proportioning valve 51 is a housing 52 of a master cylinder 52.
The valve body 53 is attached to a, and the valve body 53 is provided with a large-diameter through hole (not shown). A valve retainer 55 having a small diameter through hole 54 is provided at the opening end of the large diameter through hole on the master cylinder side. The stepped plunger 56 having the large diameter portion 56a and the small diameter portion 56b is provided in the large diameter through hole of the valve body 53 and the small diameter through hole 54 of the valve retainer 55.
Are slidably arranged. This plunger 56
It is biased in one direction by the return spring 57 and is normally held in the inoperative position.

Moreover, in the plunger 56, a communication passage 59 for communicating a brake fluid pressure passage 58 on the small diameter portion 56b side and a brake fluid pressure passage (not shown) on the large diameter portion 56a side.
Is formed, and one end small diameter portion 5 of the plunger 56 is formed.
6b and the large diameter portion 56a at the other end are respectively acted on by a brake fluid, and the plunger 56 is displaced from the non-actuated position against the urging force of the return spring 57 due to the difference in pressure receiving area.

Further, in the valve retainer 55, a valve 61 which is pressed toward the plunger 56 by a pressing spring 60 and comes into contact with and separates from a valve seat 56c at one end of a communication passage 59 of the plunger 56 is arranged in a loosely inserted state. Therefore, the valve 61 is opened when the plunger 56 is not operated, and the valve 61 is opened and closed when the plunger 56 is operated.

On the other hand, this proportioning valve 51
When the brake is attached, in the event of an abnormality, for example, when the front wheel brake system is leaked with oil and the braking becomes defective, a sufficient braking force does not act on the rear wheel brake system. For this reason, the master cylinder 52 and the proportioning valve 51 are provided with a mechanism that stops the operation of the proportioning valve 51 and applies a sufficient braking force to the rear wheel side.

That is, in the cylinder 62 of the master cylinder 52, a piston 63 of a front wheel brake system and a piston (not shown) of a rear wheel brake system that move with a constant stroke during normal operation are slidably arranged. A cylindrical member 64 having a flange 64a as a valve operation stopping mechanism is provided at the rear end of the piston 63 of the front wheel brake system.
Is fitted. Further, the shaft portion 61a of the valve 61 located on the opposite side of the plunger 56 from the valve seat 56c.
Are formed to protrude into the cylinder 62 of the master cylinder 52 for a predetermined length L.

However, when the piston of the rear wheel brake system (not shown) has moved an excessive stroke due to oil leakage of the front wheel brake system, etc., the tubular member 64 which moves in advance with the piston of the rear wheel brake system is moved. The flange 64a comes into contact with the shaft portion 61a of the valve 61 constituting the proportioning valve 51 to open the valve 61, and the proportioning valve 51 stops operating.
Therefore, the hydraulic pressure proportional to the pedaling force applied to the brake pedal is directly sent to the rear wheel brake cylinder (broken line in FIG. 5).

[0009]

However, in the above-described conventional proportioning valve 51, the peripheral groove 65 for preventing the pressing spring 60 from coming off is provided on the inner peripheral surface of the valve retainer 55, and the valve is concerned. Valve 6 that constitutes part
1. Among the members of the valve seat 56c and the pressing spring 60, one end of the pressing spring 60 is fitted into the stepped portion 61b of the valve 61, and the other end is fitted into the circumferential groove 65 of the valve retainer 55 to be assembled. Since the other end of the pressing spring 60 must be bent in an elliptical shape, it is difficult to assemble the pressing spring 60, and the forming of the circumferential groove 65 is troublesome. .

Also, the conventional proportioning valve 5
In No. 1, since the valve retainer 55 or the like is not provided with a stopper that prevents the valve 61 from moving toward the master cylinder 52 side, the piston 63 is not released when the brake is suddenly opened.
When a sudden return occurs, the tip portion of the shaft portion 61a of the valve 61 drawn into the cylinder 62 of the master cylinder 52 and the outer peripheral surface of the tubular member 64 may come into contact with each other and interfere with each other. Has a problem in that it produces abnormal noise, and wear of the valve 61 reduces reliability of brake operation.

The present invention has been made in view of the above circumstances, and an object thereof is to improve the assemblability of a spring for pressing a valve and the workability of a valve retainer, and at the same time, to provide a piston for a valve and a master cylinder. An object of the present invention is to provide a proportioning valve capable of preventing the occurrence of abnormal noise by preventing the interference with the and improving the reliability of the brake operation.

[0012]

In order to solve the above-mentioned problems of the prior art, in the present invention, a valve body attached to the housing of the master cylinder is provided, and a large-diameter through hole is provided in the valve body. A valve retainer having a small diameter through hole is provided at the master cylinder side opening end of the large diameter through hole, and a step having a large diameter portion and a small diameter portion is provided in the large diameter through hole of the valve body and the small diameter through hole of the valve retainer. A plunger is slidably disposed, and the plunger is urged in one direction by a spring to normally hold the plunger in a non-operating position, and the brake fluid pressure passage on the small diameter side and the large diameter portion side are provided in the plunger. A communication passage that communicates with the brake fluid pressure passage is formed, and a brake fluid pressure is applied to each of the one end small diameter portion and the other end large diameter portion of the plunger,
The pressure receiving area difference causes the plunger to be displaced from the non-actuated position against the biasing force of the spring, and is pushed into the valve retainer by the pressing spring toward the plunger side so that one end of the communicating path of the plunger is A valve that comes into contact with and separates from the valve seat is disposed in a loosely inserted state, the valve is opened when the plunger is not operating, and the valve is opened and closed when the plunger is operating,
A valve shaft formed on the opposite side of the valve seat of the plunger so as to project into the cylinder of the master cylinder, and the valve fitted to the piston of the master cylinder due to excessive movement of the piston. In a proportioning valve that opens the valve by an operation stopping mechanism, an engaging piece that is bent after the valve and the pressing spring are inserted and arranged is provided at a tip end portion of the valve retainer that is located on the master cylinder side. A joint piece is arranged to be engageable with the valve.

[0013]

In the proportioning valve according to the present invention,
An engaging piece that is bent after the valve and the pressing spring are inserted and arranged is provided at the tip of the valve retainer located on the master cylinder side, and the engaging piece is arranged so as to be engageable with the valve. If the engaging piece at the tip is bent after inserting the pressure spring, the pressure spring will not come out securely from the valve retainer without providing a circumferential groove as in the past, and the valve will engage when the brake is suddenly opened. It prevents the movement toward the master cylinder side by engaging with one side, so that even if the piston suddenly returns, a gap is secured between the tip of the valve shaft and the outer peripheral surface of the piston, and they interfere with each other. Will not happen.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

1 to 4 show an embodiment of a proportioning valve according to the present invention. 1 and 2
In, the proportioning valve 1 is detachably attached to the hydraulic pressure outlet 3 provided in the housing 2 a of the master cylinder 2. In the cylinder 4 of the master cylinder 2, a primary piston 5 and a secondary piston 6 are slidably arranged at intervals along the axial direction, and these pistons 5 and 6 allow two hydraulic chambers 7, 8 are defined.

When the brake pedal (not shown) connected to the master cylinder 2 is stepped on, the primary piston 5 moves forward, whereby the brake fluid pressure generated in the fluid pressure chamber 7 of the master cylinder 2 is reduced. The liquid is supplied from the hydraulic pressure outlet 3 to the rear wheel brake cylinder (not shown) via the proportioning valve 1. At the same time, the secondary piston 6 also moves forward, and the brake fluid pressure generated in the other fluid pressure chamber 8 of the master cylinder 2 is supplied to the front wheel brake cylinder (not shown) via the other fluid pressure outlet 9. ing.

A central portion of a retainer 11 is supported by a bolt 10 on the front end side of the primary piston 5, and the retainer 11 is provided so as to be movable in the axial direction relative to the bolt 10. There is. A return spring 12 for the primary piston 5 is arranged on the outer circumference of the retainer 11. On the other hand, a plastic cylindrical member 13 forming a part of the secondary piston 6 is fitted at the rear end of the secondary piston 6, and a valve is provided at the end of the cylindrical member 13 on the primary piston 5 side. A flange 13a as an operation stopping mechanism is provided so as to project in the outer peripheral direction. In addition, in FIG. 1 and FIG.
Reference numerals 4 and 15 are seal members.

The proportioning valve 1 is provided with a substantially cylindrical valve body 16 which is attached to the housing 2a of the master cylinder 2. The valve body 1
In the inside of 6, the upper through hole 17 and the intermediate through hole 1 are sequentially arranged in the direction away from the hydraulic pressure outlet 3 of the master cylinder 2.
8, the large diameter through hole 19, the lower through hole 20 and the output side hydraulic passage 21 are provided on the same axis. The large diameter portion 23a of the valve retainer 23 having the small diameter through hole 22 is fixed to the upper through hole 17 of the valve body 16 by caulking, and the small diameter portion 23b of the valve retainer 23 is inserted into the hydraulic pressure outlet 3. It has become so. A seal member 24 is fitted on the outer peripheral surface of the small diameter portion 23b of the valve retainer 23.

Further, the large-diameter through hole 19 of the valve body 16
Also, the stepped plunger 2 having the large diameter portion 25a and the small diameter portion 25b is provided in the small diameter through hole 22 of the valve retainer 23.
5 is slidably arranged, and a seal member 26 is fitted to the large diameter portion 25a located on the opposite side of the master cylinder 2. On the other hand, the small diameter portion 25b located on the master cylinder 2 side includes the valve retainer 23 and the valve retainer 2
The seal member 27 provided side by side with No. 3 is slidably penetrated, and the tip end thereof is arranged so as to project into the valve retainer 23. Moreover, the return spring 28 is disposed in the intermediate through hole 18 of the valve body 16 and between the valve retainer 23 and the flange portion 25c of the plunger 25, and by the urging force of the return spring 28, Normally, the plunger 25 is the inner wall surface 19a of the large-diameter through hole 19 on the hydraulic pressure output side.
Is held in a non-actuated position in which it abuts against.
Further, a communication passage 29 is formed inside the plunger 25 along the axial direction, and through the communication passage 29, the hydraulic pressure outlet port 3 side of the master cylinder 2, the lower through hole 20, and the output side hydraulic pressure are provided. It communicates with the passage 21.

On the other hand, in the valve retainer 23, a valve 32, which is pressed toward the plunger 25 by a pressing spring 30 and comes into contact with and separates from a valve seat 31 formed at one end of the communication passage 29, is arranged in a loosely inserted state. The valve 32
A passage 33 is provided on the outer peripheral portion of. Further, the shaft portion 32a of the valve 32 located on the side opposite to the valve seat 31 of the plunger 25 extends along the valve axial direction so as to slightly project into the cylinder 4 of the master cylinder 2 (length L in FIG. 2). The flange 1 of the tubular member 13 is formed long and the tip of the shaft portion 32a is arranged in the master cylinder 2.
It is arranged so as to contact with 3a. Then, when the shaft portion 32a of the valve 32 comes into contact with the flange 13a of the tubular member 13 as the valve operation stopping mechanism, the valve 32 is tilted and opened accordingly.

Therefore, as shown in FIGS. 3 and 4, the valve retainer 23 is manufactured into a substantially cylindrical shape by cold forging or cutting using an iron material, an aluminum material or the like as a material. Further, the valve 32 and the pressing spring 30 are provided at the tip of the valve retainer 23 located on the master cylinder 2 side.
After being inserted and disposed, the three engaging pieces 34 that are bent and function as stoppers for the valve 32 and the pressing spring 30 are integrally provided.

The engagement pieces 34 are formed by the valve retainer 23.
Extends from the tip end portion of the same to the outer peripheral surface of the small diameter portion 23b along the axial direction for a predetermined length, and is arranged at intervals along the peripheral edge of the tip end portion. Moreover, each engaging piece 3
Bent grooves 35 are respectively formed on the outer peripheral surface of No. 4 along the lateral direction. Therefore, when the valve 32 and the pressing spring 30 are inserted into the valve retainer 23 and then the engaging pieces 34 are bent toward the axial center of the valve retainer 23 from the bending groove 35, the engaging pieces 34 are As shown in FIG. 2, the valve 32 is arranged so as to be engageable with the valve 32 at an upper position in the valve retainer 23. Also, the pressing spring 30
Is disposed between the step portion 32b formed on the outer peripheral surface of the valve 32 and the bent engagement piece 34 while being prevented from coming off from the valve retainer 23.
2 is a valve retainer 23 due to the urging force of the pressing spring 30.
It is configured to be pressed toward the inner step portion 23c.

In the operating state of the stepped plunger 25, the valve 32 is the valve seat 3 of the plunger 25.
1 is seated by abutting on 1 to close the communication passage 29. Therefore, the urging force of the pressing spring 30 is set to be smaller than the urging force of the return spring 28, so that the plunger 25 causes the inner wall surface 19 of the large-diameter through hole 19 of the valve body 16.
In the non-actuated state in which it is in contact with a, the valve 32 is moved away from the valve seat 31 to hold the communication passage 29 in an open state. At this time, the outer peripheral portion of the valve 32 is in contact with the inner step portion 23c of the valve retainer 23.

In the proportioning valve 1 of this embodiment, when the brake hydraulic pressure is supplied from the hydraulic pressure outlet 3 of the master cylinder 2, the brake hydraulic pressure is applied to the passage 33 of the valve 32, the valve 32 and the valve seat 31. Through the gap between the bottom, the communication passage 29 of the plunger 25, and the lower through hole 22,
It is sent to a rear wheel brake cylinder (not shown) via the output side hydraulic passage 21. Then, when the brake fluid pressure rises and exceeds a predetermined value (operation starting point A in FIG. 5), this brake fluid pressure is supplied to the large diameter portion 25a of the plunger 25, so that the large diameter portion 25a side Pressure receiving area and small diameter part 25b
Due to the difference from the pressure receiving area on the side, the plunger 25 moves upward in FIGS. 1 and 2. Along with this, the valve 32 is closed and the increase of the brake fluid pressure to the rear wheel brake cylinder is stopped.

After that, when the brake hydraulic pressure from the hydraulic pressure outlet 3 of the master cylinder 2 further increases, the plunger 25 descends with the increase, and therefore the vertical reciprocating motion is repeated, depending on the ratio of the pressure receiving area difference. As a result, the brake fluid pressure is transmitted to the rear wheel brake cylinder at a low rate of increase with respect to the rate of increase of the brake fluid pressure to the front wheel brake cylinder.

The above operation is performed when the brake system for the front wheels and the rear wheels is normal. However, if a defect such as oil leak occurs in the brake system for the front wheels, the pressure in the hydraulic chamber 8 of the master cylinder 2 decreases. Therefore, the secondary piston 6 moves extremely leftward in FIG. Also, this secondary piston 6
Moves to the left by an excessive amount, the primary piston 5 also moves largely in the same direction.

At this time, the cylindrical member 1 on the master cylinder 2 side is positioned so that it does not abut against each other under normal conditions.
The flange 13a of No. 3 abuts on the shaft portion 32a of the valve 32 projecting from the hydraulic pressure outlet port 3 into the cylinder 4 by the length L, and presses it to the left. Therefore, the valve 32
Is tilted and held in the open state, hydraulic pressure proportional to the pedaling force of the brake pedal is continuously supplied to the rear wheel brake cylinder, and sufficient braking force can be applied to the vehicle even if the front wheel brake does not operate. Will be able to.
Also, when a defect occurs in the rear wheel brake system,
The hydraulic pressure from the secondary piston 6 is sent to the front wheel brake cylinder, so that a sufficient braking force can be applied to the vehicle.

Further, in the proportioning valve 1 of this embodiment, the hydraulic pressure chamber 7 of the master cylinder 2 is in a negative pressure state when the brake is suddenly opened, and the valve 32 resists the urging force of the pressing spring 30. As shown by the chain line, the valve 32 is drawn into the cylinder 4 and rises by a certain amount, but thereafter, the valve 32 engages with the engagement piece 34 and is prevented from moving to the master cylinder 2 side. Therefore, even if the secondary piston 6 suddenly returns, a gap is ensured between the tip of the shaft portion 32a of the valve 32 and the outer peripheral surface of the tubular member 13, so that the shaft portion 32a is held by the tubular member 13. Does not hit the outer peripheral surface of.

In the proportioning valve 1 of this embodiment, since the engaging pieces 34 are bent after the valve 32 and the pressing spring 30 are inserted into the valve retainer 23, the pressing spring 30 is inserted into the valve retainer 23. It is possible to easily dispose of it and to prevent it from coming off. Moreover, since the engagement piece 34 of this embodiment serves as a stopper that prevents the valve 32 from moving toward the master cylinder 2 side when the brake is suddenly released, the shaft portion 32 of the valve 32 is prevented.
It can prevent that a and the outer peripheral surface of the cylindrical member 13 contact each other. In addition, the valve retainer 23 of this embodiment
Does not have a complicated structure even if the engaging piece 34 is provided,
Since it can be easily manufactured using an iron material, an aluminum material, or the like, there is no fear of increasing the cost of parts.

The embodiment of the present invention has been described above.
The present invention is not limited to the embodiments described above, and various modifications and changes can be made based on the technical idea of the present invention.

For example, a bending groove 35 is formed in the engaging piece 34 of the valve retainer 23 in the above-mentioned embodiment, but the engaging piece portion of the valve retainer 23 can be easily bent. If so, such a bent groove 3
5 does not have to be formed on the engagement piece 34. Further, in the present embodiment, as shown in FIGS. 3 and 4, the wall surface of the engagement piece 34 is formed in a linear shape, but it may be formed in an arc shape. With this shape, the engagement piece 34 can be easily manufactured.

[0032]

As described above, in the proportioning valve according to the present invention, the valve retainer is provided at the opening end of the valve body attached to the housing of the master cylinder, and the pressure retainer is provided in the valve retainer to the stepped plunger side. A valve which is pressed to come into contact with and separates from the valve seat is provided, and a shaft portion of the valve is formed so as to project into the cylinder of the master cylinder. A valve operation stopping mechanism that is fitted so as to open the valve, and an engaging piece that is bent after the valve and the pressing spring are inserted and arranged is provided at a tip end portion of the valve retainer located on the master cylinder side. The engaging piece is provided so as to be engageable with the valve. Therefore, according to the proportioning valve of the present invention, the pressing spring of the valve can be easily assembled, and the retaining of the pressing spring can be reliably prevented without providing a groove in the valve retainer as in the conventional case. The assembling workability and the workability of the valve retainer can be improved. Moreover, when the brake is suddenly released, the valve engages with the engagement piece and is prevented from moving toward the master cylinder side.Therefore, even if the piston suddenly returns, the tip of the valve shaft and the master cylinder piston are Interference does not occur, abnormal noise due to wear of both is eliminated, and the reliability of brake operation can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a proportioning valve according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the proportioning valve.

FIG. 3 is a perspective view showing an entire valve retainer that constitutes the proportioning valve.

FIG. 4 is a plan view showing the valve retainer.

FIG. 5 is a characteristic diagram showing a relationship between an input pressure and an output pressure in a proportioning valve.

FIG. 6 is a sectional view showing a conventional proportioning valve.

[Explanation of symbols]

 1 Proportioning Valve 2 Master Cylinder 2a Housing 3 Fluid Pressure Outlet 4 Cylinder 5 Primary Piston 6 Secondary Piston 13 Cylindrical Member 13a Flange 16 Valve Body 19 Large Through Hole 21 Output Side Hydraulic Passage 22 Small Through Hole 23 Valve Retainer 25 Stages Plunger with 25a Large diameter part 25b Small diameter part 28 Return spring 29 Communication passage 30 Pressing spring 31 Valve seat 32 Valve 32a Shaft portion 32b Step portion 33 Passage 34 Engagement piece 35 Bending groove

Claims (2)

[Claims] 1. A valve retainer having a valve body attached to a housing of a master cylinder, having a large-diameter through hole in the valve body, and having a small-diameter through hole at an opening end of the large-diameter through hole on a master cylinder side. A stepped plunger having a large diameter portion and a small diameter portion is slidably disposed in the large diameter through hole of the valve body and the small diameter through hole of the valve retainer, and the plunger is biased in one direction by a spring. And usually keep it in the inoperative position,
A communication passage that connects the brake fluid pressure passage on the small diameter portion side and the brake fluid pressure passage on the large diameter portion side is formed in the plunger,
Brake fluid pressure is applied to one small diameter portion and the other large diameter portion of the plunger respectively, and the plunger is displaced from the non-actuated position against the biasing force of the spring by the difference in pressure receiving area, and Inside the valve retainer, a valve that is pressed toward the plunger side by a pressing spring and comes in contact with and separates from the valve seat at one end of the communication passage of the plunger is arranged in a loosely inserted state, and the valve is opened when the plunger is not operating. State, the valve is opened and closed when the plunger is operated, and the shaft portion of the valve on the side opposite to the valve seat of the plunger is formed so as to project into the cylinder of the master cylinder. When the amount of movement of the valve is excessive, a propeller that opens the valve by a valve operation stopping mechanism fitted to the piston is opened. In the tensioning valve, an engaging piece that is bent after inserting and arranging the valve and the pressing spring is provided at a tip portion of the valve retainer located on the master cylinder side, and the engaging piece is arranged to be engageable with the valve. Proportioning valve characterized by that. 2. A plurality of engagement pieces of the valve retainer are arranged at intervals along a peripheral edge of a tip end portion, and a bent groove is formed on each outer wall surface. The proportioning valve according to claim 1.