JPH0144382Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a hydraulic pressure regulating valve used in a two-system controlled hydraulic pressure circuit of a vehicle.

In hydraulic brake systems for vehicles, especially automobiles, in order to properly distribute the braking force between the front and rear wheels, after the hydraulic pressure supplied from the master cylinder exceeds a certain value (pressure reduction start pressure), A hydraulic pressure regulating valve is used that reduces the hydraulic pressure supplied to the rear wheels proportionally to the input hydraulic pressure.

There are various types of such hydraulic pressure regulating valves, but from the standpoint of automobile safety, the piping system from the master cylinder to the brakes is divided into two systems.
What is used in the so-called diagonal split brake system, which connects the right front wheel and left rear wheel to one system, and the left front wheel and right rear wheel to the other system, is as follows:
In order to ensure sufficient braking power, when one hydraulic system fails, the system has a "failure compensation function" that stops the pressure reduction in the other system and supplies the rear wheels with the same hydraulic pressure as the front wheels. It is desirable that there be.

In line with this requirement, this type of hydraulic pressure regulating valve has been actively developed for some time, and among them, the valve shown in FIG. 1, which was proposed earlier by the applicant, has a simple structure, good performance, and low manufacturing cost. It also has the advantage of being inexpensive. This hydraulic pressure regulating valve has two input ports 1,
1' and an output port 2, 2' that communicates with each input port individually, a hollow piston 5 fluid-tightly inserted into a cylinder 4 that connects both hydraulic circuits, and a coaxial valve of the main body 3. Lip seals 7, 7' engage with seats 6, 6' formed symmetrically on the upper side.
A pair of plungers 9, 9' whose rear ends are liquid-tightly guided by the piston 5 and which bring the front valve heads 8, 8' into contact with the lip seals 7, 7' to reduce pressure, and inside the piston 5, both The set spring 11 is interposed between spring retainers 10 and 10' engaged with the plungers 9 and 9', and biases each plunger in the opposite direction, that is, in the direction in which the passage is always open. The operation when the hydraulic pressures P _M and P _M ' supplied to the input ports 1 and 1' are constant values (this pressure is P _N , the load of the spring 11 is F, and the small diameter of the plunger inserted into the piston 5 is If the cross-sectional area of the part is S, then P _N =F/S)
When the pressure is exceeded, a depressurizing action is started in which the spring 11 is compressed and the plungers 9, 9' move toward each other.

On the other hand, if one of the hydraulic pressure circuits fails, that is, if the right hydraulic system fails, the input hydraulic pressure P _M ′ = 0, so the fluid acting on the piston 5 Piston 5 due to pressure imbalance
is pushed to the right, and this movement is transmitted to the plunger 9 via the snap spring 13, so
When the force pushing the piston 5 to the right becomes greater than the set load of the spring 11, the piston 5 and plunger 9 compress the spring 11 and move to the right until the piston comes into contact with the stopper 12' of the main body. In this process, the plunger 9
When the valve head 8 passes through the lip seal 7, the pressure reducing function disappears, and even if the input hydraulic pressure P _M rises above the normal pressure reducing action start pressure, the relationship P _M = P _R (output hydraulic pressure) is maintained. It will be done. If the other hydraulic system fails (P _M =0), the piston 5 comes into contact with the stopper 12 on the opposite side, and P _M '=P _R '.

In the hydraulic pressure regulating valve described above, in order to make the axial dimension of the valve body as short as possible, the stopper 12, which the piston 5 contacts, is located to the left of the input port 1, and the stopper 12' is located to the left of the input port 1'. Although it is installed on the right side, it may not be possible to bleed air from the remaining systems after removing air from one system. That is,
Bleeding air from one system is done without any problem, but
When air is removed from other systems next, the hydraulic pressure in the former becomes higher than that in the latter, so the piston 5 moves until it hits the stopper, closing the hydraulic pressure circuit in the latter (for example, when the piston 5 hits the stopper). 12', the hydraulic circuit from input port 1' to output port 2' is closed as shown by the chain line)
When such a situation occurs, it becomes impossible to bleed air from the latter.

In addition, in order to prevent the cup seals 13, 13' fitted to both ends of the piston from coming off, conventionally the seal holders 14, 14' are caulked, etc.
This makes the process time-consuming and economically disadvantageous.

Therefore, the first purpose of this invention is to provide a hydraulic pressure regulating valve that solves the problem of air bleeding without increasing the axial length of the valve body, and the second purpose is to: To provide a hydraulic pressure regulating valve which can prevent a cup seal from coming off without attaching a special seal holder and improves workability.

This invention is based on the piston 5 as shown in FIG.
An appropriate number of grooves 5a, 5a' are provided on both end faces of the first
On the other hand, the second object is achieved by forming projections 5b and 5b', which are partially deformed pistons, in front of the cup seals 13 and 13', respectively. In this way, when the piston 5 comes into contact with the stopper 12' of the main body, for example, as shown by the chain line in FIG. Therefore, the remaining air from other systems can be vented without any problem, and the cup seals 13 and 13 can be removed without any special seal holders because of the protrusions 5b and 5b' which are modified pistons 5.
13' is prevented from coming off.

Here, each of the grooves 5a, 5a' and the projections 5b, 5
b' may be provided by individual machining, but in the present invention, the set spring and its retainer may be assembled inside the piston, and since the piston 5 is formed separately and press-fitted together, press work is required. Therefore, the piston member 5c shown in FIG.
When press-fitting 5c', attach a groove-shaped wedge to the press jig, and at the same time as press-fitting, use this wedge to form grooves 5a, 5a' as shown in FIG. ' is also formed at the same time by plastic deformation of the piston 5, and an operation that normally requires three strokes can be completed in one operation.

Further, although the piston 5 is divided into two parts in the embodiment, it may be divided into more parts as shown in FIG.

Note that the other configurations and operations of the embodiment shown in FIG. 2 are the same as those in FIG. 1, so the same reference numerals are given to the figures and their explanations will be omitted.

This idea is as explained above, and according to this, even if the piston deflects in one direction, a passage for brake fluid is formed between the piston and the valve body, so there is no problem with air bleeding. Furthermore, the presence of the protrusion, which is a modified version of the piston, allows the cup seal to be held without the need for a special seal holder. Furthermore, if the groove that serves as a path for brake fluid and the protrusion that serves as a holder are formed at the same time as the piston is press-fitted, the machining process is omitted and productivity is improved.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional hydraulic pressure regulating valve, Figure 2
The figure is a perspective view showing the length of the piston according to the present invention before connection, FIG. 3 is a completed view of the same, and FIG. 4 is a sectional view showing an example of the hydraulic pressure regulating valve of the present invention. 1, 1'... Input port, 2, 2'... Output port, 3... Valve body, 5... Piston, 7, 7'...
...lip seal, 9,9'...plunger, 10,
10'... Spring retainer, 11... Set spring, 13, 13'... Cup seal, 5
a, 5a'...groove, 5b, 5b'...protrusion, 5c, 5
c′……Piston member.

Claims (1)

[Claims for Utility Model Registration] (1) A valve body having two input/output ports, a pair of lip seals arranged symmetrically on the same axis inside the body, and a valve head in contact with the seals. A plunger that performs a pressure reducing action, a piston that is inserted into a cylinder inside the valve body and fluid-tightly guides the rear end of the plunger, and a retainer that engages each plunger and moves each plunger in opposite directions. When one hydraulic circuit fails, the piston is deflected to the failed side,
In a two-system hydraulic pressure regulating valve in which the valve head of the plunger passes through a lip seal by transmitting the movement to the plunger in the normal circuit, the piston is attached to the stopper of the valve body on both end surfaces of the piston. A two-system controlled dynamic hydraulic pressure regulating valve, characterized in that a groove is provided to form a passage for brake fluid between the two when in contact with the two. (2) Utility model registration claim 1, characterized in that the piston is partially deformed and provided on the inner surface of both ends of the piston to function as a holder for a cup seal interposed between the plunger and the piston. The two-system controlled hydraulic pressure regulating valve described above. (3) The two-system controlled dynamic hydraulic pressure regulating valve according to claim 2 of the utility model registration claim, characterized in that the groove is formed by press molding, and the bulge of a piston that is plastically deformed at that time is used as the protrusion. .