JPH062854Y2 - Proportioning valve for vehicle braking - Google Patents

Description

Detailed Description of the Invention a. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle braking proportioning valve, and more particularly to a proportioning valve interposed in a rear wheel braking hydraulic system.

b. 2. Description of the Related Art In an automobile, a proportioning valve is interposed in a braking hydraulic system to obtain a nearly ideal braking pressure characteristic in a wheel cylinder.

FIG. 3 shows a master cylinder integrally provided with such a proportioning valve.

This master cylinder a is a tandem master cylinder,
The cylinder housing b has two pressure chambers c and d, and the pistons e and
f is provided. A spring g is provided between the pistons e and f and between the pistons f and the cylinder housing b.
h is interposed, and the pistons e, f are placed in a non-actuated state by the biasing forces of the springs g, h. Also,
Proportioning valves i and j are arranged in the cylinder housing b of the master cylinder a, and the output ports k and l of the cylinder housing b are connected to the rear wheel cylinder RHC and the front wheel cylinder through the proportioning i and j. Each is connected to FHC.

Then, in the master cylinder a, the piston e is operated leftward in FIG. 1 by the depression force of a brake pedal (not shown), and accordingly, the piston f is also operated leftward in FIG. As a result, the oil liquid in the pressure chambers c and d is sent out from the output ports k and l, is sent under pressure to the wheel cylinders RHC and FHC via the proportioning valves i and j, and acts on the rear wheels and the front wheels. When the brake pedal is released, the oil liquid becomes wheel cylinders RHC, F.
It is returned to the pressure chambers c and d of the cylinder housing b through the proportioning valves i and j and the output ports k and l by the reaction force of the spring of HC or the like.

c. DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In such a master cylinder a, in the wheel cylinders FHC and RHC of the front and rear wheels, in order to obtain optimum braking pressure characteristics, for example, to prevent rear wheel locking, The strengths of the springs g and h for urging e and f, the strength of springs (not shown) in the proportioning valves i and j, etc. are appropriately set.

However, when the oil liquid instantaneously flows as in the case of sudden braking, there is a possibility that the braking pressure characteristic may deviate from the desired one. However, even in this case, the rear wheel lock should be avoided. An anti-skid system is used to reliably prevent the rear wheel lock, but the device is complicated and expensive.

An object of the present invention is to provide a proportioning valve having a simple structure and a function of reliably preventing rear wheel lock.

d. In the proportioning valve for vehicle braking of the present invention, the inlet of the valve housing is formed by a plurality of holes, and an elastic plate is provided so as to leave a part of the holes and cover the other part. When the braking operation is performed, the oil liquid is guided into the valve housing through only a part of the hole, and when the braking operation is released, the oil liquid passing through the other part of the hole pushes open the elastic plate. The oil liquid is guided to the master cylinder side through all the holes.

e. In the proportioning valve for vehicle braking of the present invention, for normal braking operation, a required amount of oil liquid flows in through a part of the hole forming the inlet, and during sudden braking, the part of the hole serves as an orifice. It works to prevent the amount of oil flowing to the rear wheels to prevent the rear wheels from being locked, and when releasing the braking operation, all the holes forming the inlet are used, and the oil liquid is quickly returned to the master cylinder.

f. Embodiment FIG. 1 and FIG. 2 show a proportioning valve for vehicle braking according to the present invention.

The housing 2 of the proportioning valve 1 is composed of a body 3 and a plug 4. Large, medium, and small diameter holes 5, 6, and 7 are formed in series in the body body 3, and an outlet passage 8 that is continuous with the small diameter hole 7 and opens to the end surface of the body body 3 is formed. A valve seat 9 is arranged in an annular elastic portion formed by the medium diameter hole 6 and the small diameter hole 7 of the body body 3. A piston 10 is housed in the large, medium and small holes 5, 6, 7 of the body body 3. The piston 10 has a valve body 11 and a sliding portion 12 located in the small diameter hole 7, and a flange portion 13 located in the medium diameter hole 6, and the piston 10 has a valve body 11 and a sliding portion 12.
A through hole 14 is formed in each of the outer peripheral surfaces and communicates with the outlet passage 8. Then, the spring 15 is placed on the flange portion 13 of the piston 10, the retainer 16 is placed on the end portion of the spring 15, and then the plug 4
Is fitted into the large diameter portion 5 of the body body 3. This fit is
This is performed by press-fitting the protrusion 17 formed on the peripheral surface of the plug 4 into the inner peripheral surface of the large diameter portion 5. The plug 4 is made of synthetic resin or the like, and as shown in FIG.
Individual holes 18a and 18b. Also, this plug 4
Has a projection 19 on its end face, and an elastic plate 20 made of, for example, synthetic rubber is locked to the projection 19. The elastic plate 20 has a hole 21 in a part thereof, and the hole 21 is formed in the hole 18 of the plug 3.
It is arranged so as to match a and cover the other hole 18b.

The proportioning valve 1 configured in this way is
It is installed in the cylinder housing b so as to be connected to the constituent-side output port k of the master cylinder a. In the proportioning valve 1 in this state, the valve body portion 11 of the piston 10 is separated from the valve seat 9 of the housing 2 by the urging force of the spring 15, and the pressure chamber c of the master cylinder a.
Is communicated with the outlet passage 8 through the hole 18a of the plug 4, the gap 22 between the medium-diameter hole 6 of the body 3 and the piston 10, the gap 23 between the small-diameter hole 7 and the piston 10, and the through hole 14, and is not shown. It is connected to the rear wheel cylinder RHC.

When the brake pedal is depressed, the oil liquid in the pressure chamber c passes through the proportioning valve 1 and the rear wheel cylinder RH.
C, the rear wheels are braked, and the oil in the pressure chamber d is also fed to the front wheel cylinder FHC.
Braking the front wheels.

When the depression force of the brake pedal is released, the oil liquid is returned to the pressure chambers c and d of the cylinder housing b by the reaction force of the springs of the wheel cylinders RHC and FHC. At that time, in the rear wheel hydraulic system, the oil liquid pushes up the elastic plate 20 by the pressure, so that the oil liquid is also returned to the cylinder housing b from the hole 18b.

When sudden braking is performed, the oil liquid in the pressure chambers c and d instantly tries to flow out to the wheel cylinders RHC and FHC, but in the proportioning valve 1 on the rear wheel side, the hole 18b is closed. Therefore, the outflow of the oil liquid is restricted. Therefore, the operation of the rear wheel cylinder RHC with respect to the front wheel cylinder FHC tends to be delayed, and the rear wheel lock is prevented.

In the above embodiment, the proportioning valve 1 is directly installed in the cylinder housing b of the master cylinder a, but the proportioning valve 1 according to the present invention is shown.
Is the wheel cylinder RHC from the master cylinder a to the rear wheel.
It is possible to intervene at an appropriate position of the hydraulic system up to.

Further, in the above embodiment, the proportioning valve 1 having the inlet at one end of the valve housing and the outlet at the other end is shown, but the present invention is not limited to the valve of the above embodiment.

Furthermore, in the above-mentioned embodiment, the example in which the normal proportioning valve is also provided in the front wheel side hydraulic system has been described, but the front wheel side hydraulic system does not have a proportioning valve, that is, the rear wheel side hydraulic system. Of course, it can be applied to a braking system having a proportioning valve only in the system.

g. Effect of the Invention As described above, the proportioning valve for vehicle braking according to the present invention prevents a large amount of oil liquid from intruding into the valve instantaneously, thus preventing rear wheel lock and braking operation. After the release, the oil liquid can be smoothly returned to the master cylinder, and the structure is extremely simple.

[Brief description of drawings]

FIG. 1 is a sectional view showing a proportioning valve for vehicle braking according to the present invention, FIG. 2 is a plan view of the valve, and FIG. 3 is a sectional view showing a master cylinder having a proportioning valve. 1 ... Proportioning valve, 2 ... Housing, 3 ... Body body, 4 ... Plug, 5, 6, 7 ... Hole, 8 ... Outlet passage, 9 ... Valve seat, 10 ... Piston, 11 ... Valve body, 12 ... Sliding Part, 13 ... Flange part, 14 ... Through hole, 15 ... Spring, 16 ... Retainer, 17 ... Projection, 18 ... Inlet, 18a, 18b ... Hole, 19 ... Projection part, 20 ... Elastic plate, 21 ... Hole.

Claims (1)

[Scope of utility model registration request] In a proportioning valve for vehicle braking interposed in a rear wheel hydraulic system between a master cylinder and a rear wheel cylinder, an inlet of a valve housing is constituted by a plurality of holes, and the holes of these holes are formed. An elastic plate is arranged so as to cover the other part while leaving a part, and the oil liquid is introduced into the valve housing through only a part of the hole at the time of braking operation. A proportioning valve for vehicle braking, wherein the oil liquid that has passed through the portion pushes the elastic plate open to guide the oil liquid to the master cylinder side through all of the holes.