JPH0613288B2 - Dual-system proportioning valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proportioning valve for two systems, and more particularly to a proportioning valve having a function of releasing pressure reduction control of the other system when the hydraulic system of one system fails. .

[Conventional technology]

Proportioning valves are used for the purpose of approximating the braking force distribution between the front and rear wheels of a vehicle to an ideal braking force distribution ratio, and various types have been conventionally provided.

As one of such proportioning valves, it is suitable for a vehicle having a double-pipe type brake hydraulic system, and is a proportioning system for two systems in which a so-called break point spring is shared by two proportioning valves. Various valves have also been proposed.

By the way, regarding such a proportioning valve for two systems, as a countermeasure against hydraulic pressure failure of one system, the proportioning function of the other system should not be hindered, and more desirably, the proportioning of the other system should be performed. In many cases, it is required to devise measures such as canceling the function to compensate for the insufficient braking force of the entire vehicle.

[Problems to be Solved by the Invention]

The present invention has been made based on such a viewpoint, and an object of the present invention is to provide a proportioning valve for two systems in which one breaking spring is shared, in the case where a hydraulic pressure failure of one system occurs, Proportioning valve for dual system that can release the proportioning operation of the proportional valve of the system and transmit large brake hydraulic pressure to the rear wheels of the normal system to compensate for insufficient braking force of the entire vehicle is provided. Where it is.

[Outline of Invention]

Therefore, the characteristic of the dual system poro proportioning valve according to the present invention made for such a purpose is that the rear wheel brake oil pressure is moved by moving in the cylinder by the balance of the biasing spring force and the hydraulic action. Proportioning valves with a control piston for opening and closing the valve part that controls decompression compared to hydraulic pressure are provided in two sets for independent two-system brake piping, and these are arranged in parallel, and these two sets of proportioning valves in parallel are arranged. Straddling the end of each control piston,
A movable spring seat, which is moved in parallel when both control pistons move simultaneously, and tilted when only one of the control pistons moves, is engaged with the ends of the two control pistons in an associated manner. Further, there is provided a two-system proportioning valve in which a coil-type folding point spring, which has a spring force acting uniformly on both control pistons as the biasing spring force, is engaged with the movable spring seat. An extension shaft extending inside the coil type break point spring is provided, and at the valve fixing part,
Where a recess is provided to receive the movement of the tip of the extension shaft when the movable spring seat moves in parallel, and an engaging portion that prevents the movement of the tip of the extension shaft when the movable spring seat is tilted. is there.

[Action]

According to the configuration of the present invention described above, if the proportioning valves of the two systems are both normal, the characteristic of the pressure reducing output is commonly obtained by the common break spring, and if there is a failure in the one system, the spring seat The movement is blocked, and the pressure reduction control of the rear wheel brake hydraulic pressure in the normal system is released.

Example of Invention

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

In the figure, reference numeral 1 is a body, and 2 is a casing fixed to the body, and two sets of proportioning valve mechanisms having exactly the same function are incorporated in the casing.
In the following description, unless otherwise specified, the proportioning valve mechanism on the upper side of the drawing will be described, and the other proportioning valve mechanism on the lower side will be described by adding 100 to the same member. The description was omitted.

Reference numeral 3 denotes a large-diameter cylinder formed in the body 1. Two cylinders having a stepped large diameter are sequentially formed from the large-diameter cylinder 3 toward the casing 2, and the cylinder having the largest diameter is a sleeve fixing cylinder. 4, a fixed sleeve 5 fixed by a stopper ring 7 is attached. Reference numeral 6 denotes a small-diameter cylinder of the inner cylinder portion of the fixed sleeve 5, which is concentric with the large-diameter cylinder 3 and is opposed to the large-diameter cylinder 3 with difficulty.

Reference numeral 8 denotes a first portion of the control piston which is slidably fitted through the small diameter cylinder 6, and 8'is a second portion of the control piston which is slidably fitted to the large diameter cylinder 3. The first portion 8 and the second portion 8'is united by caulking. (Hereinafter, these are collectively referred to as the control piston 8).

The control piston 8 has a built-in on-off valve 9 that opens and closes the flow path by the movement of the piston 8, and the control piston and the input oil chamber A _i facing the central portion of the shaft of the control piston 8 through the valve 9. One end of 8 (the tip in the large-diameter cylinder 3) communicates with the output oil chamber A _o facing and is connected so as to be able to be shut off. The input oil chamber A _i is connected to a hydraulic chamber of a tandem master cylinder (not shown) via an input port 14, and the output oil chamber A _o is connected to a rear wheel brake device via an output port 15.

The on-off valve 9 is composed of a combination of a ball valve body 10, a hold spring 11, a valve seat 12, and a locking rod 13.
In the illustrated normal state, the locking rod 13 pushes the ball valve body 10 against the hold spring 11 to separate it from the valve seat 12 and open the flow path (thus, the input / output oil chambers A _i , A _o Communication), and when the control piston 8 moves to the left in the figure, the ball valve element 10 by the locking rod 13
Is pressed to engage the valve seat 12, and the flow path is closed (thus, the input / output oil chambers A _i and A _o are shut off).

Reference numeral 16 is a piston cup, and 23 and 24 are husband and wife seal rings, which are used for pressure-sealing the oil chambers A _i and A _o .

Next, a mechanism for urging a spring force for generating a break point on the control piston 8 will be described. In the apparatus of this example, two sets of mechanisms including the control vistons 8 and 118 are provided in the body 1. The other ends of the control pistons 8 and 118 that are juxtaposed and extend from the small diameter cylinders 6 and 116 to the casing 2 side are provided so as to form projections 8a and 108a having a semicircular cross section. The movable spring seat 18 into which the recesses 18a and 118a having a semicircular cross section corresponding to are fitted is assembled, and one folding point spring 19 is engaged with the movable spring seat 18. Reference numeral 17 is a spring accommodating chamber in the casing 2, and 20 is a fixed spring seat that supports the other end of the break point spring 19.

The movable spring seat 18 includes one break point spring 1
With the center line of 9 as the symmetry line, the two control pistons 8 and 108 arranged in parallel are engaged with each other, so that the biasing spring force is evenly applied to both control pistons 8 and 108. .

In addition, the movable spring seat 18 of this example is the break point spring 1
9 has a shaft portion 18b extending inside, and the shaft portion 118b.
The tip of the is opposed to the recess 21 of the fixed spring seat 20,
When the movable spring seat 18 is moved by receiving a substantially uniform pressing reaction force from two parallel control pistons, it can be inserted into the recess 21 in a loosely fitted state. The wall portion of the recess 21 has stepped portions 22 and 122 with which the extended tips are engaged when the movable spring seat 18 is tilted.
Are provided as a pair, and the movable spring seat 18 is prevented from moving to the left in the figure by engaging with the stepped portion.

The tilting of the movable spring seat 18 is caused by the movement of only one of the two control pistons 8 and 108 arranged in parallel, and the state shown by the imaginary line in the figure shows the case where only the upper control piston 18 moves. It shows a tilted state. Such a state occurs when the hydraulic system related to the lower proportioning valve mechanism in the figure fails, and conversely, when the hydraulic system related to the upper proportioning valve mechanism fails, the movable spring seat 18 tilts in the opposite direction ( (Clockwise direction in the figure).

According to the above configuration, if the hydraulic pressure in each system of the double pipe is normal, the spring force of one break point spring acts evenly on the two control pistons 8 and 108 in parallel, Normally, the braking pressure reduction control of the rear wheel side brake hydraulic pressure is generated, but when one of the hydraulic systems fails, the movable spring seat 18 is tilted, and therefore, the extension shaft portion 18 of the movable spring seat 18 is tilted.
Stepped portion 22 whose tip of b is formed on the fixed spring seat 20
(Or 122), the movement of the movable spring seat 18 is blocked, and thus the movement of the control piston 18 of the normal system (the side of the upper proportioning valve mechanism in the figure) is locked, and the control piston The braking pressure reducing operation of the brake hydraulic pressure on the rear wheel side due to the movement of 18 is released.

It is needless to say that the movable spring seat 18 is provided in such a dimensional relationship that the shutoff operation of the opening / closing valve portion in the control piston 8 (or 108) does not occur due to the tilting of the movable spring seat 18.

Further, the present invention is not intended to be limited to such an embodiment, and for example, each proportioning valve mechanism may be applied in combination with a known inertial valve mechanism, or for one-system fail detection. A switch for detecting the tilt of the movable spring seat may be attached.

According to the above proportioning valve for two systems, 2
In addition to the effect of sharing a part of the proportioning valves of the set, a preferable control state in which the break pressure reducing control of the other system is released when the failure of one system is obtained, and further The effect is that the configuration for the purpose is extremely simple and easy.

〔The invention's effect〕

According to the present invention, by adopting and utilizing a simple structure in which the posture of the movable spring erected over two sets of proportioning valves arranged in parallel is tilted when the hydraulic pressure of one system is lost, Since the proportioning operation of the system can be released, the number of parts is small, and the assembling work is easy, it can be provided as an extremely inexpensive product and the effect of its practical use is extremely great.

[Brief description of drawings]

The drawing is a schematic vertical sectional view of the configuration of a proportioning valve showing an embodiment of the present invention. 1: Body 2: Casing 3,103: Large diameter cylinder 4,104: Sleeve fitting cylinder 5,105: Fixed sleeve 6,106: Small diameter cylinder 7,107: Stopper ring 8,108: Control piston (Part 1) ) 8 ', 108': Control piston (second part) 9, 109: Open / close valve part 10, 110: Ball valve body 11, 111: Hold spring 12, 112: Valve seat, 13, 113: Locking rod 14, 114: input port 15,115: output port 16,116: piston cup 17: spring accommodating chamber 18: movable spring seat

Claims (1)

[Claims] 1. A proportioning valve having a control piston for opening and closing a valve portion for controlling the rear wheel brake hydraulic pressure to be reduced compared to the front wheel brake hydraulic pressure by moving in a cylinder by a balance between an urging spring force and a hydraulic action. When two sets of independent two-system brake pipes are provided and they are arranged in parallel, straddling the ends of the control pistons of these two sets of proportioning valves in parallel, and when these control pistons move simultaneously, A movable spring seat, which is translated in parallel and is tilted when only one of the control pistons moves, is engaged with the ends of the control pistons in cooperation with each other, and the spring force is the biasing spring force. A proportioning valve for two systems, in which a coil type break point spring that acts equally on both control pistons is engaged with the movable spring seat as The movable spring seat is provided with an extension shaft portion that extends inside the coil-shaped break point spring, and the fixed portion of the valve is a recess that receives movement of the extension shaft end when the movable spring seat moves in parallel. And a proportioning valve for two systems, which is provided with an engaging portion that prevents movement of the tip of the extension shaft portion when the movable spring seat is tilted.