JPH07108656B2 - Brake fluid pressure control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a brake fluid pressure control device used for an automobile or the like.

<Prior Art> As a conventional brake fluid pressure control device, for example, the actual development 54
The one disclosed in Japanese Patent Publication No. 111030 is known.

A conventional hydraulic pressure control device will be described with reference to FIG.
A differential piston e having a large-diameter pressure receiving part b that receives the hydraulic pressure of the outflow chamber a that communicates with the brake cylinder side, and a small diameter pressure receiving part d that receives the hydraulic pressure of the inflow chamber c that communicates with the hydraulic pressure generation source;
A valve mechanism that senses a predetermined deceleration and controls the source pressure of the hydraulic pressure on the outflow chamber a side; and an adjusting piston f that opens the valve mechanism when the hydraulic pressure in the inflow chamber c further rises and reaches a predetermined pressure. Made of.

The above-mentioned valve mechanism is composed of a valve seat g provided at the end of the differential piston e on the inflow chamber c side and a ball h, and the ball h is brought into contact with and separated from the valve seat g to move from the inflow chamber c to the outflow chamber a. It is configured to control the opening and closing of the flow path communicating with the.

The hydraulic pressure control operation in the above-described configuration will be outlined. In the differential piston e, when the brake hydraulic pressure starts to increase and the hydraulic pressure acting on the large diameter pressure receiving portion b and the small diameter pressure receiving portion d reaches a predetermined force, the inflow chamber When the pressure shifts to the c side, and at this time reaches a predetermined deceleration, the ball h rolls to enable the opening and closing action of the valve mechanism to control the hydraulic pressure on the outflow chamber a side at a constant rate. When the hydraulic pressure in the inflow chamber c further rises and the differential piston e is returned to its original position by the adjusting piston f, the follower of the rolling ball h is blocked by the stopper k, so that the inflow chamber c and the outflow chamber a. The fluid pressure in the inflow chamber c and the fluid pressure in the outflow chamber a are made to be the same.

<Problems to be Solved by the Present Invention> The conventional brake fluid pressure control device has the following problems.

(A) It is ideal to control the distribution of the brake fluid pressure of the front and rear wheels in accordance with the ideal fluid pressure distribution curve according to various conditions such as the axle weight of the front and rear wheels of the vehicle.

However, the conventional brake hydraulic pressure control device has a small number of refraction times during one brake operation, and in the latter half, the hydraulic pressure of the brake cylinder rises in proportion to the hydraulic pressure of the hydraulic pressure generation source.

Therefore, it is difficult to approximate the ideal fluid pressure distribution curve that draws a parabola.

(B) During brake operation, the seal member i provided on the outer periphery of the differential piston e and the seal member j provided on the adjusting piston f make minute reciprocating motions under different pressure environments on both axial sides thereof. .

Therefore, the rubber seal members i and j are easily deteriorated.

<Object of the present invention> The present invention has been made in view of the above problems, and an object of the present invention is to control the hydraulic pressure on the outflow chamber side during one brake operation in multiple stages. Brake cylinder hydraulic pressure can be approximated to the ideal hydraulic pressure distribution curve,
Moreover, it is an object of the present invention to provide a brake fluid pressure control device that can improve the durability of the seal member by limiting the piston movement during pressurization to one direction.

<Means for Solving Problems> The above object is to provide a brake fluid pressure control device with a valve mechanism for opening and closing a fluid path connecting an inflow chamber and an outflow chamber based on detection of a predetermined deceleration and a load. This can be achieved by configuring with a piston interposed between the chamber and the outflow chamber, and a support member that regulates the movement amount of the piston.

<Operation> During braking, the hydraulic pressure in the outflow chamber rises in proportion to the inflow chamber, and when a predetermined deceleration or load is detected, the valve mechanism closes the flow path to keep the hydraulic pressure on the outflow chamber side constant. To be done.

When the pressure on the inflow chamber side increases, the piston moves to the outflow chamber side, and the hydraulic pressure on the outflow chamber side increases at a constant rate.

When the movement of the piston is restricted by the support member, the fluid pressure on the outflow chamber side, which had risen at a constant rate due to the valve mechanism closing the flow path, is maintained at a constant pressure, and the pressure on the inflow chamber side further rises. The support member moves to the outflow chamber side together with the piston, and the hydraulic pressure on the outflow chamber side rises again at a constant rate.

<First Embodiment> First, a first embodiment applied to a valve type that senses a deceleration of a vehicle and cuts hydraulic pressure in an outflow chamber will be described with reference to FIGS.

<B> Configuration of brake hydraulic pressure control device 1 is a housing having a stepped hole 1a with a bottom, and a small-diameter inflow chamber communicating with the hydraulic pressure generation (not shown) via a connection port 1b formed at the bottom. 1c and cap 2 attached to the opening
And a large-diameter outflow chamber 1d communicating with a brake cylinder (not shown) via a connection port 2a.

A plurality of grooves 1e are formed on the inner surface of the housing 1 forming the inflow chamber 1c, and the inertia balls 3 are movably accommodated therein.

Reference numeral 4 denotes a flow plate having openings, which regulates the retracted position of the inertial ball 3 and controls the flow of the brake fluid.

Reference numeral 5 is a piston having a communication hole 5a therein, and an inflow chamber 1c thereof.
The valve seat 6 attached to the side and the inertia ball 3 constitute a valve mechanism for controlling the opening / closing of the communication from the inflow chamber 1c to the outflow chamber 1d.

Reference numeral 7 denotes a support member having a hydraulic pressure receiving portion of different diameter slidably fitted in the stepped hole 1a of the housing 1.

The support member 7 slidably inserts the piston 5 into a stepped hole 7a formed therein, and a stepped portion 7b formed in the stepped hole 7a regulates the movement of the piston 5 to the inflow chamber 1c side. ing.

Further, the support member 7 has a small diameter portion 7c disposed on the inflow chamber 1c side and a large diameter portion 7d disposed on the outflow chamber 1d side, and the side surface of the large diameter portion 7d abuts against the stepped surface 1f of the housing 1 The movement of the member 7 to the inflow chamber 1c side is restricted.

Reference numeral 8 denotes a stopper that restricts the movement of the piston 5 toward the outflow chamber 1d, and is provided in the stepped hole 7a of the support member 7 so as to project from the piston 5 at a predetermined interval.

Reference numeral 9 is a spring member that connects the piston 5 and the support member 7 to the inflow chamber 1c.
Always urged towards the side.

Reference numeral 10 is a bleeding disc that controls the flow of the brake fluid in the outflow chamber 1d.

Reference numerals 11 to 13 denote annular seal members, which are attached to the outer circumference of the piston 5 and the outer circumferences of the small diameter portion 7c and the large diameter portion 7d of the support member 7, respectively.

<B> Operation Next, the operation will be described.

The brake fluid pressure control device of the present invention is mounted on the spring portion of the vehicle with the bottom side (right side in FIG. 1) lowered by θ °.

Therefore, the inertia ball 3 is maintained in a state of contacting the flow plate 4 by its own weight.

Now, when the brake pedal is depressed, the hydraulic pressure is supplied due to the hydraulic pressure generated by a master cylinder or the like (not shown), but the inertia ball 3 does not move until a predetermined deceleration is reached.

As a result, a certain clearance is secured between the inertia ball 3 and the valve seat 6, and the hydraulic pressure passes through this clearance to allow the hydraulic pressure to flow into the inflow chamber 1c and the piston 5.
It is sent to a brake cylinder (not shown) through the communication hole 5a, the outflow chamber 1d, and the connection port 2a of the cap 2.

The hydraulic pressures of the inflow chamber 1c and the outflow chamber 1d in this state increase proportionally at the same pressure.

The hydraulic pressure characteristics at this time are 0 to A (when the vehicle is empty) or 0 to A '(when the vehicle is loaded), as shown in FIG.

In the hydraulic pressure characteristic diagram of FIG. 2, the horizontal axis represents the inflow chamber hydraulic pressure, and the vertical axis represents the outflow chamber hydraulic pressure. In the figure, a is the ideal hydraulic pressure distribution curve when the vehicle is empty, and b is the vehicle hydraulic pressure when the vehicle is loaded. The ideal hydraulic pressure distribution curve of is shown.

Then, when the hydraulic pressure of the hydraulic pressure source rises and the deceleration of the vehicle reaches a predetermined value, the inertia ball 3 rolls to the piston 5 side due to inertia and sits on the valve seat 6, closing the communication hole 5a. Therefore, the break point is obtained at B (when the vehicle is empty) or B ′ (when the vehicle is loaded) shown in FIG.

Therefore, even if the hydraulic pressure in the inflow chamber 1c rises, the piston 5 does not move until the hydraulic force acting on the piston 5 overcomes the biasing force of the spring member 9, and the hydraulic pressure in the outflow chamber 1d becomes constant. The hydraulic pressure characteristics of C (when empty) or C ′ (when loaded) shown in FIG. 2 are obtained.

Subsequently, when the hydraulic pressure in the inflow chamber 1c rises and the hydraulic force acting on the piston 5 reaches a first predetermined pressure that overcomes the biasing force of the spring member 9, D shown in FIG. 2 (when empty) Or, at the corner of D '(when loaded), the piston 5 moves to the outflow chamber 1d.
Inertia ball 3 in the direction of reducing the volume (left side in FIG. 1)
And the hydraulic pressure on the outflow chamber 1d side is increased at a constant rate until the piston 5 contacts the stopper 8.

By the way, the support member 7 with the stopper 8 attached has a small diameter portion.
Since the piston 5 is pressed in the direction of the inflow chamber 1c due to the difference in the hydraulic force acting on the 7c and the large diameter portion 7d, the piston 5 is temporarily stopped when it comes into contact with the stopper 8, and the hydraulic pressure in the outflow chamber 1d is It is maintained at a constant pressure again.

Therefore, the hydraulic characteristics at this time are E-break point to F (when the vehicle is empty) or E'break point to F '(when the vehicle is loaded).

The hydraulic pressure in the inflow chamber 1c continues to rise, and the small diameter portion of the support member 7
When the hydraulic force acting on 7c reaches a second predetermined pressure that overcomes the hydraulic force acting on the large diameter portion 7d, G shown in FIG.
A direction in which the piston 5, the support member 7, and the inertia ball 3 are integrated to reduce the volume of the outflow chamber 1d by obtaining a break point (when the vehicle is empty) or G '(when the vehicle is loaded) (left side in FIG. 1). A hydraulic characteristic is obtained in which the hydraulic pressure on the side of the outflow chamber 1d is increased at a constant rate by moving to.

<Modification 1> Next, a modification of the present invention will be described with reference to FIGS.

It should be noted that the same parts as those in the figure are denoted by the numeral of 100 and the description thereof is omitted.

While the embodiment shown in FIG. 3 has a structure in which the support member 7 of the embodiment shown in FIG. 1 is arranged so as to surround the piston 5, this modification is supported on the outflow chamber 101d side of the piston 105. This is a structure in which the members 107 are arranged in series.

In the case of this modification, the support member 107 when the brake is not operated is of a type in which it is urged toward the inflow chamber 101c by the residual pressure, but of course the support member 107 and the bleeding disc 1 are used.
A weak spring may be contracted between 10 and 10.

Further, the ball guide 115 is press-fitted into the stepped hole of the housing 101 to accommodate the inertial ball 103 slidably, and the support member 107 is provided at the front end portion 115a and the piston 105 is provided at the central step portion 115b. It supports and regulates the movement of both to the inflow chamber 101c side.

Further, the valve seat 106 is attached to the piston 105 by the seal retainer 116.
Is stuck to.

<Modification 2> In the modification shown in FIG. 4, instead of removing the spring member 9 of FIG. 1, the piston 205 is formed to have a hydraulic pressure receiving portion having a different diameter, and the residual pressure of the liquid passage is used. The piston 205 and the support member 207 are biased toward the inflow chamber 201c.

That is, a small-diameter portion 205b on the inflow chamber 201c side, a piston 205 having a large-diameter portion 205c formed on the outflow chamber 201d side is fitted into the stepped hole 207a of the support portion 207, and a valve attached to the rear end of the small-diameter portion 205b. seat
A seal portion integrally formed with 206 is liquid-tightly fitted in the stepped hole 207a.

<Modification 3> In the modification shown in FIG. 5, the support member 307 is formed into a plate shape, and the support member 307 is provided with a strong second spring member 317 to inflow the chamber 30.
It is urged toward the 1c side, and the first spring member 309 causes the inflow chamber 3
It is adjacent to the outflow chamber 301d side of the piston 305 biased toward the 01c side.

The pressure reduction gradient can be appropriately set by changing the spring force of the first and second spring members 309 and 317.

The above-described modifications 1 to 3 have almost the same characteristics as the hydraulic characteristics shown in FIG.

<Modification 4> In a modification shown in FIG. 6, a piston 405, a supporting member 407, etc. are arranged in the same manner as in FIG. 1, and a second piston 418 having a hydraulic pressure receiving portion having a different diameter is further added. Thus, more multistage hydraulic characteristics can be obtained.

That is, the second piston 418 having the small diameter portion 418a on the inflow chamber 401c side and the large diameter portion 418b on the outflow chamber 401d side is arranged on the outflow chamber 401d side of the support member 407 and receives the movement of the support member 407 When the predetermined pressure is reached, the volume of the outflow chamber 401d moves in a direction of reducing the volume, and the hydraulic pressure on the outflow chamber 401d side is increased again at a constant rate.

The second piston 418 has the same support member 4 as in the above modification.
It may be arranged on the outer periphery of 07, or may be biased toward the inflow chamber 401c by a spring member without having different diameters.

<Second Embodiment> Next, FIGS. 7 to 9 show an example applied to a valve type for detecting a vehicle load in the second embodiment.

<A> Configuration First, the configuration of the present embodiment will be described with reference to FIG.

Reference numeral 519 denotes a plunger slidably accommodated in the housing 501, which has a load receiving portion 519a protruding from the housing 501 at one end and a valve seat 5 attached to the piston 505 at the other end.
It has a valve head 519b that forms a valve mechanism in cooperation with 06.

A seal member 520 seals the housing 501 and the load receiving portion 519a, and has a diameter smaller than the pressure receiving diameter of the valve head 519b.

521 is a retaining plate that prevents the seal member 520 from retaining, and 522 is a valve spring that biases the valve mechanism in the valve opening direction.

Since the configuration other than the above is the same as that of the previous embodiment, its description is omitted.

<B> Operation Next, the operation will be described.

Now, when the hydraulic pressure is supplied to the inflow chamber 501c, the valve mechanism is in the open state until the predetermined hydraulic pressure is reached, so that the valve mechanism is directly fed to the outflow chamber 501d, and is shown as J (when the vehicle is empty) or J shown in FIG. Obtain the hydraulic characteristics of ′ (when loaded).

Then, the hydraulic pressure in the inflow chamber 501c rises, and the load receiving portion 51
When the hydraulic force acting on 9a overcomes the acting force W corresponding to the loaded load and the load of the valve spring 522, the plunger 519 moves to the right in the drawing and the valve head 519b temporarily moves the valve seat 506. Although the valve head 519b is closed, the pressure receiving area of the valve head 519b is larger than the pressure receiving area of the load receiving portion 519a, so the plunger 519 moves to the left and the valve head 519b separates from the valve seat 506 to supply the hydraulic pressure to the outflow chamber 501d. Will be sent.

By repeating such an operation, the hydraulic pressure in the outflow chamber 501d is reduced at a constant rate with respect to the rise in the inflow chamber 501c.

The decompression starting point of this hydraulic pressure characteristic is the point K (when empty) or K ′ (when loaded) in FIG. 8 and is L (when empty) or L ′.
It is decompressed as (when loaded).

When the hydraulic pressure in the inflow chamber 501c continues to rise and the hydraulic force acting on the piston 505 reaches a first predetermined pressure that overcomes the biasing force of the spring member 509, the piston 505 is integrated with the valve seat 506 in the figure. The valve mechanism is closed as it moves to the left of
Get (empty) or M '(when loaded).

This break point M or M'corresponds to D or D'in the diagram shown in FIG. 2 of the first embodiment.

Since the subsequent operation is the same as that of the first embodiment, its explanation is omitted.

<Modification> Next, a modification of the second embodiment will be described with reference to FIG.

In this modification, the load receiving portion 619a is arranged in the outflow chamber 601d.

That is, when the hydraulic pressure in the inflow chamber 601c rises and the hydraulic pressure acting on the load receiving portion 619a overcomes the acting force W corresponding to the loaded load and the load of the valve spring 622, the plunger 619 moves to the left in the figure. Since the valve head 619b continues to close the valve seat 606 as it moves toward the other side, the fluid pressure in the outflow chamber 601d is maintained at a constant pressure, and exhibits fluid pressure characteristics as shown by the dotted line in FIG.

Thereafter, the same hydraulic characteristics as described above are obtained by the action of the piston 605 and the support member 607.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be obtained.

(B) By controlling the hydraulic pressure in the outflow chamber with respect to the hydraulic pressure in the inflow chamber in multiple stages, the ideal hydraulic pressure distribution curve can be extremely approximated.

Therefore, the effect of preventing early locking of the wheels is significantly improved, and the braking effect can be effectively exerted.

(B) The sealing member only moves in one direction during braking.

Therefore, the durability of the seal member is improved as compared with the related art, and reliable hydraulic pressure control can be performed for a long period of time.

[Brief description of drawings]

 FIG. 1 is a sectional view of a first embodiment according to the present invention. FIG. 2 is a hydraulic pressure characteristic diagram of the first embodiment. FIGS. 3 to 6 are main parts of a modification of the first embodiment. Sectional view FIG. 7: Sectional view of the second embodiment FIG. 8: Hydraulic characteristic diagram of the second embodiment FIG. 9: Sectional view of essential parts of a modification of the second embodiment. FIG. 10: Cross-sectional view of conventional brake fluid pressure control device

Claims (1)

[Claims] 1. A brake fluid pressure control device for a vehicle, wherein a fluid pressure in an outflow chamber communicating with a brake cylinder is reduced with respect to a fluid pressure in an inflow chamber communicating with a fluid pressure generating source. A valve mechanism that senses a load and depressurizes the hydraulic pressure on the outflow chamber side, and when this valve mechanism is in a depressurized operating state and the hydraulic pressure in the inflow chamber rises to reach a first predetermined pressure, A piston that moves in the direction of reducing the volume to increase the hydraulic pressure on the outflow chamber side at a constant rate; and a support member that regulates the movement amount of the piston to cut off the increase in pressure on the outflow chamber side, When the hydraulic pressure in the inflow chamber rises and reaches the second predetermined pressure,
The brake fluid pressure control device, wherein the piston and the support member are configured to move in a direction of reducing the volume of the outflow chamber to re-pressurize the fluid pressure on the outflow chamber side at a constant rate.