JPH0611262Y2 - Brake fluid pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is a brake fluid pressure control that is attached to a rear wheel brake system of a brake device of an automobile or the like and controls the brake fluid pressure according to the deceleration of the automobile. It relates to the device.

(Prior Art) Four-wheeled vehicles such as automobiles are equipped with a brake device for all wheels, but since the wheels are affected by the inertial force that acts during traveling, the brake fluid must be applied when operating this. It is necessary to change the pressure between the front wheels and the rear wheels. That is, in the initial state of braking, the same pressure is applied to both the front and rear wheels, but when the braking force is applied, the inertia of the vehicle body affects the front wheels, so the pressure on the rear wheels must be weakened. There is a risk that the wheel will lock. For this reason, a brake fluid pressure control valve is provided between the master cylinder and the wheel cylinder,
The effect of hydraulic pressure on the rear wheels is changed to the effect on the front wheels.

A brake fluid pressure control valve, which is a premise of the brake fluid pressure control device according to the present invention, will be described with reference to FIG. Reference numeral 1 denotes a housing, which is actually mounted on the vehicle body with the right side in the figure raised by an appropriate angle with respect to the left side. A connection port 2 to a wheel cylinder (not shown, the same applies hereinafter) is formed at the front end of the housing 1, and a cap 3 attached to the rear end is connected to a master cylinder (not shown). A mouth 4 is formed. A piston 6 having a hole 5 in the center is slidably fitted inside the housing 1. Further, a ball 7 for controlling the opening / closing of a hole 5 provided at the center of the piston 6 is movably accommodated on the side of the connection port 4 from the piston 6 to the master cylinder.

More specifically, a cylinder portion 8 in which a piston 6 is slidably inserted in a part of the inside of the housing 1
And a housing portion 9 for the ball 7 are integrally formed, and a cylindrical body 10 is inserted from the left side of the drawing. A flow plate 11 for restricting the returning position of the ball 7 is assembled between the cylindrical body 10 and the cap 3 through an O-ring 12 for sealing.

The flow plate 11 regulates the returning position of the ball 7, and the surface of the flow plate 11 changes the flow of the brake fluid and suppresses the pressure rise of the brake fluid to stabilize the movement of the ball 7. Has been drilled. Hole 13
As shown in FIG. 6, the flow plate 11 is provided at one place at the center of the surface portion and at four symmetrical positions near the outer peripheral portion, for a total of five places. The hole 13 at the center is the connection port 4 of the cap 3.
It faces a hole 14 provided in the center of the.

A ball guide portion 15 and a plurality of grooves 16 are formed in the storage portion 9 for the balls 7 of the cylindrical body 10. As shown in FIG. 6, a plurality of ball guide portions 15 are radially formed with respect to the center line of the cylindrical body 10. A seal member 17 is provided around the hole 5 in a portion of the piston 6 at the center end portion thereof on the ball 7 side. When the ball 7 moves to the right in FIG. To completely close the hole 5.

A bleeding disc 19 is provided in a chamber 18 formed on the right side of the piston 6 inside the housing 1. The bleeding disc 19 is provided with a protrusion (not shown) or the like so as not to hinder the flow of the brake fluid.

The brake fluid pressure control valve having such a configuration is mounted on the vehicle body with the right side of the housing 1 in the drawing raised by a predetermined angle with respect to the left side as described above. A rear wheel and a wheel cylinder (not shown) are connected to the connection port 2, and a master cylinder (not shown) is connected to the connection port 4.
The wheel cylinder of the front wheel is directly connected to the master cylinder without such a brake fluid pressure control valve.

When a brake pedal (not shown) is depressed to generate hydraulic pressure in the master cylinder, this hydraulic pressure is applied directly to the front wheel cylinders and to the rear wheel cylinders via this brake hydraulic pressure control valve. Will be done.
Therefore, the braking force of the front wheels is proportional to the depression angle of the brake pedal, but the braking force of the rear wheels is affected by the brake fluid pressure control valve.

When the depression angle of the brake pedal is small and the braking force is still not large, the brake fluid from the master cylinder is supplied from the connection port 4 to the hole 14, as shown by the arrow in FIG.
The hole 13 of the float plate 11, the groove 16 formed in the accommodating portion 9 of the ball 7 of the cylindrical body 10, and the surface of the ball 7 into the hole 5 of the piston 6 to reach the connection port 2 from the chamber 18, It will flow to the wheel cylinder of the wheel. The pressure relationship at this time is shown by P ₁ and P ₂ in FIG. 7, and is represented by a straight line a. The rear wheels are thereby braked.

At this time, since the ball 7 is on the left side in the drawing due to its own weight, the hole 5 of the piston 6 is not closed, and the ball 7 acts as described above. When the brake pedal is further depressed to increase the braking force, the ball 7 moves up the inclined surface in the cylindrical body 10 by the inertial force and comes into close contact with the seal member 17 of the piston 6 to close the hole 5. As a result, the brake fluid pressure acting on the wheel cylinders of the rear wheels is closed at the portion beyond the hole 5 of the piston 6, and as shown by the straight line b in FIG. 7, the hydraulic pressure on the master cylinder side, that is, the connection port 4 side increases. It will remain unchanged regardless of the situation.

Further, when the brake pedal is depressed and the hydraulic pressure on the master cylinder side rises, this hydraulic pressure acts on the pressure receiving surface of the piston 6 (the surface on the ball 7 side), and the hole 5 is kept closed by the ball 7. The piston 6 is pressed to the right in the figure while keeping the above condition. As a result, the chamber from the hole 5 of the piston 6
The brake fluid inside 18 and further in the pipeline leading to the wheel cylinder receives pressure, and the wheel cylinder is increased in hydraulic pressure as indicated by a straight line c in FIG. 7. By such an action, the brake fluid pressure to the rear wheels is controlled, and the rear wheels are prevented from locking.

(Problems to be solved by the invention) However, in the above-mentioned brake fluid pressure control valve of the conventional brake fluid pressure control device, the flow direction of the brake fluid flowing into the ball storage portion is the same as the moving direction of the ball moved by inertial force. Therefore, when the brake pedal is depressed, there is a problem that the moving speed of the ball tends to change depending on the flow velocity of the brake fluid. In particular, when the brake pedal is pressed at a high speed, the flow velocity and pressure increase speed of the brake fluid are also increased, the movement of the ball becomes unstable, and the speed at which the piston hole of the ball is blocked varies, resulting in the specified characteristics being obtained. There was a problem that I could not do.

A brake fluid pressure control valve that is installed in the brake system of the rear wheels and controls the brake fluid pressure in response to the deceleration of the vehicle is used as a brake fluid pressure control valve between the inlet chamber into which the brake fluid flows and the control chamber that changes the pressure direction. In addition, a throttling passage for throttling is provided until the control piston reaches a predetermined moving amount.
61-22055), but this is not a throttle valve for stably moving a ball as in the present invention.

The present invention has been made to solve the above-mentioned conventional problems, and the valve is opened / closed between the master cylinder of the brake system of the rear wheel and the brake fluid pressure control valve according to the speed at which the brake pedal is depressed. It is therefore an object of the present invention to provide a brake fluid pressure control device that stabilizes the moving speed of a ball inside the brake fluid pressure control valve by interposing a brake fluid pressure control auxiliary valve that controls the pressure increase rate of the brake fluid.

(Means for Solving the Problem) The present invention provides a brake fluid pressure control device including a brake fluid pressure control valve 23 between a master cylinder 21 and a wheel cylinder 22 that closes a brake fluid passage according to deceleration. At the front end of the housing 24, the brake fluid pressure control valve 23
Connection port 25 to the master cylinder 21 at the rear end.
A spring 30 for slidably fitting a piston 30 having a through hole 28, 29 formed in the vicinity of the center and the outer peripheral portion of the housing 24 and having a connection port 27 formed therein. 31 is inserted, the brake fluid pressure control auxiliary valve 20 having a seal member 32 disposed in one of the front end 30a of the piston 30 and the inside of the housing 24 facing the front end 30a of the piston 30 is provided, The brake fluid pressure control auxiliary valve 20 is arranged between the master cylinder 21 and the brake fluid pressure control valve 23.

(Operation) Since such a brake fluid pressure control auxiliary valve 20 is arranged between the master cylinder 21 of the rear wheel brake system and the brake fluid pressure control valve 23, the brake pedal depression speed is normally high. At the time, it is the connection port 27 with the master cylinder 21.
The brake fluid that has flowed in from flows through the through holes 28 and 29 provided in the center of the piston 30 and in the vicinity of the outer periphery, and then flows into the brake fluid pressure control valve 23 from the connection port 25. When the depression speed becomes faster, the hydraulic pressure of the brake fluid flowing from the master cylinder 21 into the brake fluid pressure control auxiliary valve 20 is
The piston 30 is pushed forward against the spring 31. As a result, the piston 30 comes into contact with the seal member 32 disposed inside the housing 24 facing the front end portion 30a of the piston 30 and closes the passage through the through hole 29 formed near the outer peripheral portion of the piston 30a. The passage is only through holes 28 and 29 formed in the center of the piston 30. Therefore, the brake fluid is throttled by the through holes 28, 29, and the brake fluid flowing into the brake fluid pressure control valve 23 becomes gentle,
The flow velocity is constant and the ball is stable.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3 and the same members as those in FIG. As shown in the block diagram of FIG. 3, the brake fluid pressure control device of the present invention includes a brake fluid pressure control valve 23 between a master cylinder 21 of a rear wheel brake system and a wheel cylinder 22. The pressure control auxiliary valve 20 is interposed.

The brake fluid pressure control auxiliary valve 20 will be described. First
In the figure, 24 is a housing. This housing 24
Has a connection port 25 to the brake fluid pressure control valve 23 connected to the wheel cylinder 22 at the front end (right side in the figure), and a master cylinder on the cap 26 attached to the rear end (left side in the figure). A connection port 27 to 21 is formed. And
A piston (see FIG. 2) 30 having an H shape in a side view is slidably fitted inside the housing 24.

A through hole 28 for the brake fluid and a through hole 29 made of an orifice are provided at the center of the piston 30, and two through holes 29 made of the orifice are provided at two symmetrical positions near the outer circumference. Furthermore, inside the housing 24 there is a piston
A spring 31 for urging 30 backward is fitted and inserted. Further, the seal member 32 is provided on the inner wall portion 24a inside the housing 24 facing the front end portion 30a of the piston 30 on the connection port 25 side of the housing 24.
Is attached. In the figure, 33 is an O-ring and 34 is a bleeder plug.

Such a brake fluid pressure control auxiliary valve 20 is interposed between the master cylinder 21 and the brake fluid pressure control valve 23 of the brake system for the rear wheels to form a brake fluid pressure control device. In the connection, the brake fluid pressure control valve 23 connected to the rear wheel and the wheel cylinder 22 is connected to the connection port 25 on the front end side of the housing 24 of the brake fluid pressure control auxiliary valve 20. The master cylinder 21 is connected to the connection port 27 on the rear end side. Now, when the brake pedal is depressed and hydraulic pressure is generated in the master cylinder 21, this hydraulic pressure is applied to the wheel cylinders 22 of the rear wheels via the brake hydraulic pressure control auxiliary valve 20 and the brake hydraulic pressure control valve 23. It will be.

During a normal gentle brake operation, the brake fluid flows from the connection port 27 provided in the cap 26 to the housing 24 of the brake fluid pressure control auxiliary valve 20, as shown by the solid line in FIG.
It enters the inside and flows into the brake fluid pressure control valve 23 through the connection port 25 from the through hole 28 formed in the center of the piston 30, the through hole 29 formed of the orifice, and the through hole 29 formed of the orifice formed in the vicinity of the outer peripheral portion.

On the other hand, when the brake pedal is suddenly depressed, the piston
A through hole 29 formed of an orifice formed near the central portion and the outer peripheral portion of 30 increases the hydraulic pressure on the master cylinder 21 side and decreases the hydraulic pressure on the brake hydraulic pressure control valve 23 side, so that the piston 30 brakes. By the liquid pressure of the liquid, the first
It is pushed to the right side in the figure and pressed against the seal member 32 (see FIG. 4).

As a result, the passage passing through the through hole 29 formed of the orifice formed near the outer peripheral portion of the piston 30 is closed, and
As shown by the solid line in the figure, the brake fluid flows from the through hole 28 formed in the center and the through hole 29 formed of the orifice, and flows into the brake fluid pressure control valve 23 from the connection port 25.

Therefore, even if the brake pedal is suddenly depressed, the pressure increase rate of the brake fluid by the brake fluid pressure control auxiliary valve 20 becomes slow, and the ball 7 of the brake fluid pressure control valve 23 on the downstream side is affected by this brake fluid. Disappears. This stabilizes the basic performance of the brake fluid pressure control valve 23.

(Effects of the Invention) As described above, according to the present invention, the brake fluid pressure control auxiliary valve in which the piston having the through hole is slidably inserted is provided between the master cylinder and the brake fluid pressure control valve. The hydraulic pressure of the brake fluid flowing into the brake fluid pressure control valve can be controlled by this through hole. Therefore, the brake fluid pressure does not suddenly increase at any speed of the brake operation, the flow velocity of the brake fluid is always constant, and the movement of the ball of the brake fluid pressure control valve is stable. Further, since the pressure increase rate of the brake fluid is suppressed in this manner, the ball is stabilized and each member constituting the brake system is protected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
3 is a perspective view of the piston of the brake fluid pressure control auxiliary valve shown in FIG.
FIG. 4 is a block diagram showing an arrangement position of the brake fluid pressure control auxiliary valve of the rear wheel brake system, and FIG. 4 is a sectional view of the brake fluid pressure control auxiliary valve showing the operation of the piston when the brake is suddenly depressed. 5 is a sectional view of the brake hydraulic pressure control valve, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5, and FIG. 7 is a graph for explaining the operation of the brake hydraulic pressure control valve. 20 …… Brake fluid pressure control auxiliary valve 21 …… Master cylinder 22 …… Wheel cylinder 23 …… Brake fluid pressure control valve 24 …… Housing 25,27 …… Connection port 28,29 …… Through hole 30 …… Piston 31 ...... Spring 32 …… Seal member

Claims (1)

[Scope of utility model registration request] 1. A brake fluid pressure control device comprising a brake fluid pressure control valve between a master cylinder and a wheel cylinder for closing a brake fluid passage in accordance with deceleration, wherein the brake fluid pressure is provided at a front end of a housing. A piston with a through hole near the center and outer circumference is slidably inserted into the housing by forming a connection port to the control valve and a connection port to the master cylinder at the rear end. Along with
A brake fluid pressure control auxiliary valve having a seal member is provided by inserting a spring for urging the piston into one of the front end portion of the piston and the inside of the housing facing the front end portion of the piston. A brake fluid pressure control device, wherein a fluid pressure control auxiliary valve is connected between the master cylinder and the brake fluid pressure control valve.