JPH0241100Y2 - - Google Patents

Description

[Detailed description of the invention] The invention relates to a hydraulic pressure control valve, and in particular, when the hydraulic pressure introduced from the master cylinder rises above a predetermined value, the valve is activated in two symmetrically provided hydraulic pressure chambers. This is a hydraulic pressure control valve whose piston slides in the direction of closing the brake fluid flow path to control the hydraulic pressure.In particular, it prevents wear and damage of the seal members that close each of these hydraulic pressure chambers, and improves the sealing effect. This relates to a hydraulic control valve that can be connected for a long period of time.

Generally, in the speed braking mechanism of an automobile, the force applied from the brake pedal is converted into hydraulic pressure in the master cylinder, and this hydraulic pressure is applied to the front and rear brake units using a hydraulic pressure control valve. But the pressure is converted to fit the rear wheel.

In other words, the maximum hydraulic pressure transmitted to the rear wheels is controlled to be lower than the hydraulic pressure transmitted to the front wheels, and ideally, the front brake unit becomes more effective as the braking force increases. The relationship between the front wheel braking force and the rear wheel braking force is 2.
Preferably, the braking force is distributed as represented by the following curve. Therefore, in order to bring this braking force closer to the ideal distribution, a hydraulic pressure control valve shown in FIG. 1 is used.

FIG. 1 is a vertical cross-sectional view of an example of a conventional hydraulic control valve, in which brake fluid sent from a master cylinder (not shown) is branched into two parts, and each brake fluid is supplied to each inlet 1, Enter from 2, each hydraulic pressure chamber A,
At B, after adjusting the hydraulic pressure, each brake fluid is discharged from each outlet 3, 4 and sent to a rear wheel brake unit (not shown). The two hydraulic pressure chambers are formed symmetrically, and valve pistons 5 and 6 (hereinafter simply referred to as pistons 5 and 6) are slidably disposed in each of the hydraulic pressure chambers A and B, respectively. Each piston 5,
For example, poppet valves 7 and 8 are provided at one end of 6, respectively.
A hydraulic pressure control means such as the above is provided, and the hydraulic pressure is adjusted to a predetermined value while the brake fluid passes through the poppet valves 7 and 8. That is, each poppet valve 7, 8 has a valve body 7a, 8a, a valve seat 7b, 8b, a valve stem 7c, as usual.
8c and springs 7d, 8d, and when each piston 7, 8 slides toward the center so as to approach each other in each hydraulic pressure chamber A, B,
While the valve bodies 7a and 8a approach the valve seats 7b and 8b, respectively, and the flow passages are blocked, when the pistons 7 and 8 slide into contact with each other so as to be separated from each other,
The flow path is opened and the hydraulic pressure of the brake fluid is regulated in this way.

In addition, sliding members 9 and 10 are provided on the outer periphery of each piston 5 and 6 so as to be slidable, and the shoulder portions 9a and 10a of each of the sliding members 9 and 10 are engaged with elastic material such as rubber synthetic resin or other material. Elastic member 1 made of material
1 and 12 are arranged, and each elastic member 11 and 12 is opposed to the end surface of each piston 5 and 6. Therefore,
If one side fails, one of the sliding members 9 and 10 slides toward the center by hydraulic pressure and presses the elastic members 11 and 12, thereby removing the piston-facing surface of the elastic member. bulges out, thereby preventing each piston 5, 6 from sliding. Therefore, the poppet valves 7 and 8 are maintained in an open state, and a so-called cut action does not occur.

Further, the two hydraulic chambers A and B are sealed by cup-shaped seal members 13 and 14, that is, so-called cup seals 13 and 14, respectively, and these seal members 13 and 14 prevent brake fluid from leaking. Ru. Each sealing member 13, 14 is arranged between the piston 5, 6 and the sliding member 9, 10, and the second
As shown enlarged in the figure, the sealing member 13,
14 is held, and each sealing member 13, 14 is
As shown in the figure, the inner circumferential surface side protrudes, and this protruding portion is held down by pressing members 15, 16, and the inner circumferential surfaces of the protruding portions contact the pistons 5, 6 to be completely sealed.

However, when controlling the brake fluid, since the seal members 13 and 14 are structured as described above, the inner circumferential surface of the protruding portion is in complete contact with the outer circumferential surface of each piston 5 and 6. When sliding, the paths of the seal members 15, 16 and the paths of the presser members 15, 16 overlap. Therefore, the inner circumferential surface of each seal member 13, 14 comes into contact with the outer circumferential surface of each piston 5, 6, which has been roughened by the sliding of each presser member 15, 16. , 14 is accelerated, the sealing effect is rapidly lost, and this often leads to automobile accidents. From this point, as shown in FIG. 2, the inner diameter of the presser members 15, 16 is set to be smaller than the outer diameter of the pistons 5, 6 so that the inner circumferential surfaces of the presser members 15, 16 do not contact the outer circumferential surfaces of the respective pistons 5, 6. Attempts have been made to make it larger, that is, looser, but it is difficult to assemble, and furthermore, machining is also performed to minimize damage to the inner circumferential surface. However, the former method deteriorates the ease of assembly, and the latter method increases the number of manufacturing steps, which is undesirable.

The purpose of this invention is to solve the above-mentioned drawbacks, and specifically, the present invention is a hydraulic control valve that greatly improves the durability of the hydraulic control valve by preventing damage to the sealing member that seals each hydraulic chamber. propose.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

The hydraulic control valve according to the present invention has the same structure as that of the conventional example shown in FIG. 1, except for the structure of the seal member and presser member, which will be described later. Each hydraulic pressure chamber A, B of the hydraulic pressure control valve configured as shown in FIG.
As shown in FIGS. 3 and 4 (in each of these figures, only the hydraulic pressure chamber A is shown for convenience of explanation), a brake fluid chamber is provided that engages with the sliding member 9. Seal member 13 to prevent leakage
A notch 13a is formed in a part of the inner circumferential surface of the
The portion where the seal member 13 contacts the outer circumferential surface of the piston 5 and the portion where the inner circumferential surface of the presser member 15 contacts the outer circumferential surface of the piston 5 are prevented from overlapping. That is, the sealing member 13 is formed in an annular shape as in the conventional example, but as shown in FIG. The outer peripheral side is made to protrude, and the presser member 5 is brought into contact with the end face of the protrusion 13b with a gap as desired, and the seal member 13 is held down by the presser member 15 through the protrusion 13b. Note that instead of the configuration shown in FIG. 3, as shown in FIG. 4, one end of the holding member 15 may be bent and the tip of this bent portion may be inserted into the sealing member 13 to hold the sealing member 13. .

Furthermore, the notch portion 13a is formed over a length l ₁ corresponding to the sliding length l ₁ of the holding member 15 on the piston 5 (that is, the sliding length of the holding member 15 during hydraulic pressure control). When the seal member 13 slides on the piston 5, the inner circumferential surface of the seal member 13 is prevented from contacting the area where the holding member 15 contacts the outer circumferential surface of the piston 5 during sliding.

For example, in the conventional example shown in FIG. 1, when pressure is generated in the hydraulic chambers A and B, the pistons 5 and 6 move by l ₁ toward the center with a predetermined stroke, as shown in FIG. In some cases _, in the conventional hydraulic control valve shown in FIG.
also slides by l ₁ ′. Since the holding member 15 is made of a metal plate, the sliding movement of the holding member 15 causes the area _l2 of the outer peripheral surface of the piston 5 to come into contact with a hard metal plate, and the surface is worn and roughened. Therefore, when the inner peripheral surface of the seal member 13 comes into contact with this damaged part,
The contact surfaces are damaged and the sealing effect is rapidly lost.

On the other hand, in the present invention, since a notch 13a is provided in a part of the inner peripheral surface of the seal member ₁₃ as shown in FIG. Since there is no overlap in the sliding range _l1 of 15, the sealing member 13 is not damaged and the sealing effect is not rapidly lost.

Further, when the sealing member 15 is configured as shown in FIG. 4 as described above and the support portion 15a of the holding member 15 is inserted into the sealing member 13, the holding member 15 is attached to the outer peripheral surface of the piston 5. Without contact, the sealing member 13, the sliding range l ₁ ' and the holding member 1
The same effect can be achieved without overlapping the sliding range _l1 of No.5.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a conventional hydraulic control valve;
Figure 2 is an enlarged view of a part of it, Figures 3 and 4.
The figure is a partially enlarged view of a hydraulic control valve according to each embodiment of the present invention. Codes 1, 2...Each inlet, 3, 4...Each outlet, 5, 6...Valve piston, 7, 8...Poppet valve, 7a, 8a...Valve body, 7b, 8b...Valve seat , 7c, 8c... Valve stem, 7d, 8d... Spring, 9, 10... Sliding member, 9a, 10a...
Shoulder part, 11, 12... Each elastic part, 13, 14...
Seal member, 15a...Support part, 15, 16...
A cup-shaped holding member. 17, 18...Spring.

Claims (1)

[Claim for Utility Model Registration] When the hydraulic pressure introduced from the master cylinder rises above a predetermined value, the valve piston is slid in the direction of closing the brake fluid flow path within two symmetrically provided hydraulic pressure chambers. controlling the introduction liquid pressure, and
In the hydraulic control valve, each of the hydraulic pressure chambers is sealed on the outer periphery of the valve piston by a cup-shaped sealing member, and each of these sealing members is held down by a pressing member, wherein at least the inner peripheral surface of the sealing member is cut out over a length corresponding to the length of the portion where the holding member makes sliding contact on the valve piston, and the holding member holds down the other portion of the sealing member except for the inner circumferential surface thereof. A hydraulic control valve characterized by: