JPS6330596Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic pressure control device for double piping in a vehicle brake system.

It has long been known that when braking a vehicle, the braking force on the front and rear wheels needs to be reduced by a predetermined percentage compared to the front wheel due to the difference in the pressing force of the wheels against the road surface. .

For this purpose, a proportioning type (or limiting type) hydraulic pressure control device that distributes and controls front and rear wheel brake fluid pressure is provided.
Furthermore, in order to improve vehicle safety, an active proportioning valve mechanism is installed for one system, and the other system is connected to the active proportioning valve mechanism. A hydraulic control device has also been provided that includes an interlocking valve mechanism that performs pressure reduction control.

Such a hydraulic pressure control device for double piping has the effect of improving safety because even if one system fails, the braking force is secured by the hydraulic pressure of the other system. When one system fails, the entire vehicle's brake system tends to be insufficient. Therefore, in this case, it is desirable to cancel the pressure reduction control of the rear wheel brake fluid pressure in the normal system and transmit the same fluid pressure as the front wheel side to the rear wheel side to compensate for the lack of braking force of the entire vehicle. The present invention provides a configuration suitable for this purpose.

That is, one of the hydraulic pressure control devices for double piping equipped with this type of interlocking valve mechanism provided by the applicant is a valve that is divided into two hydraulic pressure systems, A system and B system. A control piston that moves against the spring force of a control spring due to the hydraulic action in the A system with respect to two normally stationary valve seats that constitute the valve parts of each of the A and B systems in the cylinder;
A balance piston that moves in the same direction as the control piston is installed so as to balance the output hydraulic pressures of both systems A and B, and the control piston and the valve seat on the A system side actively control the input pressure of the A system. There is a system in which the output hydraulic pressure is controlled to be reduced, and the B-system input/output hydraulic pressure is passively controlled to be reduced by the cooperation of the B-system side valve seat of the balance piston. In a hydraulic pressure control device for double piping with such a configuration, in order to cancel pressure reduction control in the other system due to a failure in one system, hydraulic pressure control is performed between the control piston and the valve seat of the balance piston. What is necessary is to release the relative movement that brings about the cooperation (opening and closing of the valve part). For example, under normal conditions, the control by the two pistons can be performed independently, but if a fluid pressure failure occurs on the B system side, the balance piston is activated in only one direction (from the A system side to the B system side). If the pressure reduction control operation of the control piston is canceled by utilizing the large movement of the ballast piston due to hydraulic pressure, at least the pressure reduction control on the A system side will be possible when the B system fails. This will compensate for the lack of braking force in the entire vehicle.

For the purpose of canceling such relative movement, it is conceivable to provide, for example, a fail clip that links these two pistons (control piston and balance piston) so as to restrict their separation to below a certain value.

The present invention was made precisely to solve the above-mentioned problems, and in particular, it is a hydraulic pressure control for double piping that is sufficient to link the two pistons and has a structure as simple as possible. The purpose is to provide equipment.

To achieve this purpose, the double piping hydraulic control device of the present invention is characterized by being slidably fitted to the valve cylinder and having a balance cylinder formed at both ends in the center of the cylinder. The open cylindrical plunger is slidably fitted to the balance cylinder to divide the inside of the valve into A and B2 hydraulic systems, and
The A system is controlled by a balance piston that operates to balance the hydraulic pressure in the output liquid chambers of both systems, a hold spring that presses and biases the plunger toward the B system side, and a control piston that moves backward from the plunger under the action of hydraulic pressure. The proportioning valve mechanism in system A controls the pressure reduction between the input and output liquid chambers in the system, and the balance piston moves in the same direction as the control piston under the action of hydraulic pressure to control the input and output in system B. It is equipped with an interlocking valve mechanism in the B system that controls the pressure reduction between the liquid chambers, and a fail-safe clip that limits the separation of the control piston and balance piston to a certain length or less, and the fail-safe clip is attached to the side panel. The opposing left and right edges of the two legs of the letter shape are provided so as to form circular inner surfaces interspersed with opposing arcuate portions, and one of the opposing arcuate portions is fitted and fixed in the circumferential groove of the control piston, and The opposing arcuate portion is configured to loosely fit into the circumferential groove of the balance piston with a certain degree of freedom in the axial direction.

The present invention will be described below based on embodiments shown in the drawings.

In the figure, 1 is the valve body, 2, 2',
2'' is a valve cylinder formed at one end of the valve chamber, and 3 is a blind hole cylinder formed at the other end of the valve chamber to face these valve cylinders 2, 2', 2''; It opens at the inner end of the plug 4 that closes the plug. Reference numerals 5 and 5' designate cylindrical fail-safe pistons (plungers) that are slidably fitted to the valve cylinders 2, 2', and 2'', and a middle cylinder 6 is formed in the first portion 5 of the fail-safe piston. The balance piston 7 is slidably fitted to divide the valve chamber into A and B2 system liquid chambers, and the fail-safe piston 5,
5' is biased by a small spring force of a hold spring 14 through the valve seat 13 described below, and is pressed into engagement with the body wall surface of the B system side liquid chamber on the valve cylinder 2, 2', 2'' side. .

Further, the balance piston 7 is formed with extending portions on both left and right sides, and the extending portion into the B system chamber is a valve body portion 8 that cooperates with the valve seat 24 described below to form a driven valve mechanism. and the other A
The extending portion into the system chamber is provided with a circumferential groove 9 into which a fail-safe clip 30 (described below) is loosely fitted in the axial direction with a certain degree of freedom.

Next, the valve mechanisms of the A and B systems will be explained. In the A system, the tip head faces the end of the balance piston 7, and the rear end small diameter part is fitted into the blind hole cylinder 3. A control piston 10 that is slidably fitted, a control spring 12 that presses the control piston 10 toward the distal end, and the control piston 1
The input/output liquid chamber a ₁ is inserted into the A system chamber by loosely fitting into the shaft part of 0.
a ₂ and a valve seat 13 that cooperates with a valve body portion 11 formed at the top end of the control piston 10 to form a proportioning type active valve mechanism. 16,17,1
8 is the spring seat, 19 is the piston cup, 20
indicates input liquid chamber _a1 and A-system master cylinder (not shown)
21 is an output port that connects the output liquid chamber _a2 to the A-series rear wheel brake system (not shown).

The operation of such a valve mechanism is known, and the seal cross-sectional area of the valve body 11 is A ₁ , the cross-sectional area of the blind hole cylinder 3 is A ₂ , the spring force of the control spring 12 is F, and input/output The liquid pressure in liquid chambers a ₁ and a ₂ is Pa ₁ ,
If pa ₂ , then Pc (=Pa ₁ , Pa ₂ ) = F/A ₂ At the corner value Pc, the control piston 10 starts moving to the left in the figure, and the valve body 11 comes into contact with the valve seat 13. to close the communication between the input and output liquid chambers a ₁ and a ₂ , and after this, the output liquid pressure Pa ₂ is slowly increased with respect to the input liquid pressure Pa ₁ at an angle of taθ = (A ₁ − A ₂ ) / A ₂ .

On the other hand, in the B-system interlocking valve mechanism, a valve seat 24 assembled inside the cylinder of the fail-safe piston 5' divides the B-system chamber into input and output liquid chambers b ₁ and b ₂ , and the balance piston 7 The valve body portion 8 is configured to come into close contact with the valve seat 24 due to the movement, thereby controlling opening and closing of communication between the input and output liquid chambers b ₁ and b ₂ . That is, the valve body portion 8 of the balance piston 7 is provided so as to have the same sealing cross-sectional area A3 as the middle cylinder 6 with which the balance piston 7 is slidably engaged, and therefore the hydraulic action is controlled by _A3 in the left-right direction in the figure. The system moves so that the system output hydraulic pressure Pa ₂ and the B system output liquid chamber Pb ₂ are balanced, and as the A system hydraulic pressure control starts, the A system output hydraulic pressure Pa ₁ changes to the A system input hydraulic pressure.
When the pressure is reduced relative to Pa ₁ (same as the B system input hydraulic pressure Pb ₁ ), the balance piston 7 moves to the left in the figure (in the same direction as the movement of the control piston 10), and the valve body 8 moves toward the valve seat 24. , the communication between the input and output liquid chambers b ₁ and b ₂ is closed, and after this, the A and B system output liquid pressure Pa ₂ ,
Raise Pb ₂ to the same pressure. 25 is valve seat 2
4 is the hold spring, 26 is the spring seat,
27 is an input port that connects the input fluid chamber b ₁ to the B-system master cylinder, and 28 is an output port that connects the output fluid chamber b ₂ to the B-system rear wheel brake device.

The feature of the present invention is that the control piston 10 and the balance piston 7, which constitute the valve mechanisms of the A and B systems as described above, are connected via a fail-safe clip 30 having the following configuration, so that the relative This is because the separation is restricted to a certain length l ₁ or less.

That is, the fail-safe clip 30 has a U-shape on the side, and has substantially semicircular or similar arcuate portions 32, 32 facing each other at the portions where the left and right edges of both sides 31, 31 face each other. The opposing arcuate portions 32, 32 are fitted and fixed into the circumferential groove 15 formed in the head of the control piston 10, and the other opposing arcuate portions 32, 32 are fitted into the circumferential groove 9 of the balance piston 7.
It is provided so that it is loosely fitted with a degree of freedom of a constant length _l1 in the axial direction.

Due to this configuration of the fail-safe clip 30, the separation of the balance piston 7 from the control piston 10 is restricted to a constant length _l1 , and therefore, a hydraulic pressure failure occurs in one of the A and B systems. In this case, A
When the system fails, the fail-safe pistons 5, 5' easily press the hold spring 14, which has a small load, and move together with the balance piston 7, so that control with small loss is performed. Further, when the B system fails, the control piston 10 is pulled to the left by the balance piston 7 via the failsafe clip 30, and hydraulic pressure control is canceled. By arranging the shape of the failsafe clip 30 as described above,
Normally, the fail-safe clip 30 fits loosely into the balance piston 7 without contacting it, so that the effect is obtained that the sliding resistance at this portion does not affect the control characteristics of the device operation.

In this example, the control spring 12 of the control piston 10 is connected to the fail-safe clip 30 and the fail-safe pistons 5, 5'.
However, this may be configured to be locked by the balance piston 7.

As described above, the double piping hydraulic pressure control device of the present invention ensures stable valve operation to reduce the output hydraulic pressure during normal times, and cancels the valve operation of the normal system when one system fails. This makes it possible to obtain a sufficient increase in the output hydraulic pressure, that is, the rear wheel brake hydraulic pressure, and the practical benefits thereof are extremely large.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of a hydraulic pressure control device for double piping showing an embodiment of the present invention, and Fig. 2 A and B are views showing fail-safe clips, A is a side view and B is a rear view. It is a diagram. 1... Valve body, 2, 2', 2''... Valve cylinder, 3... Blind hole cylinder, 4... Plug,
5, 5'...Fail-safe piston, 6...Balance cylinder, 7...Balance piston, 8...
... Valve body part, 9 ... Circumferential groove, 10 ... Control piston,
11... Valve body portion, 12... Control spring, 13
... Valve seat, 14 ... Hold spring, 15 ... Circumferential groove, 16, 17, 18 ... Spring seat, 19 ... Piston cup, 20 ... Input port, 21 ... Output port, 24 ... Valve seat , 25...Hold spring, 26...Spring seat, 27...Input port, 28...Output port, 30...Fail-safe clip, 31
... Leg, 32 ... arcuate part.

Claims (1)

[Scope of utility model registration request] A cylindrical plunger with open ends at both ends that is slidably fitted to the valve cylinder and has a balance cylinder formed in the center of the cylinder, and a cylindrical plunger that is slidably fitted to the balance cylinder and divides the inside of the valve into two hydraulic systems, A system and B system. At the same time, a balance piston operates to balance the liquid pressures in the output liquid chambers of both systems, and a hold spring presses and biases the plunger toward the B system side.
A proportioning valve mechanism in the A system that performs pressure reduction control between the input and output liquid chambers in the A system by a control piston that moves backward from the plunger under the action of hydraulic pressure; An interlocking valve mechanism in the B system that performs pressure reduction control between the input and output liquid chambers in the B system by the balance piston moving in the same direction, and a valve mechanism that limits the separation of the control piston and balance piston to a certain length or less. The fail-safe clip is provided such that the opposing left and right edges of both legs having a U-shape on the side form a circular inner surface that is interspersed with opposing arcuate portions, and one opposing arcuate portion. is fitted and fixed in the circumferential groove of the control piston, and the other opposing arcuate part is configured to loosely fit into the circumferential groove of the balance piston with a certain degree of freedom in the axial direction. Hydraulic pressure control device for heavy piping.