JPS6027718Y2 - Automotive load-responsive braking hydraulic control valve device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a brake hydraulic pressure control valve for an automobile, particularly to a live load responsive dual brake hydraulic pressure control valve device, and further to a structure of a live load detection spring thereof.

Braking systems for automobiles have already been provided which are equipped with two hydraulic control valves, or hydraulic proportioning valves, for two separate hydraulic circuits for the purpose of braking safety.

Conventionally, in this type, each body of the two hydraulic proportioning valves was made into a single body, making the assembly of the dual proportioning valve easier and more efficient, but the load detection spring Two are attached to each proportioning valve separately.

This proposal aims to further improve the efficiency and ease of assembly, work, and other handling by unifying this detection spring.

However, when the detection spring is unified, when the strokes of the valves that it interlocks are different, especially when the hydraulic pressure circuit to which one of the valves belongs is damaged, the load detection operation of the detection spring becomes erroneous and the hydraulic pressure control is affected. Has a tendency to go crazy.

In order to avoid this tendency, the present invention divides a unified detection spring into two spring pieces by a partition hole, and each spring piece is individually linked to each valve.

The main idea will be explained below with reference to the figures.

In FIG. 1, the right arm 1 is pivotally connected by a hole 2 at its lower end to a so-called unsprung part of an automobile body, such as a part of a rear differential gearbox.

One end of a detection spring 4 for detecting a vehicle's payload is pivotally connected to the pin 3 at the upper end of the arm 1 through an eye 24 thereof.

The eye 23 at the other end of the detection spring 4 is pivoted by a pin 5 at a suitable location on a so-called sprung portion 6 of the vehicle.

Reference numeral 7 denotes a hydraulic control valve (hereinafter also referred to as a hydraulic proportioning valve or P valve), which is fixed to the sprung portion 6 of the vehicle.

As shown in FIG. 2, two P valves 7 are provided in parallel in a double arrangement in a body 8, each having a valve 9.

Both valves 9 have one end exposed to the outside and are abutted and engaged with the detection spring 4.

Each valve 9 has a valve portion 10.

The valve portion 10 is located facing an annular rubber sheet 11.

The valve part 11 and the seat 11 cooperate to perform a valve function,
The brake fluid pressure is controlled as described later.

The shaft 12 of the valve 9 slidably passes through the plug 13 to expose one end to the outside and engages the detection spring 4 as described above.

A valve mechanism consisting of a valve part 10 and a seat 11
A chamber 14 and a chamber 15 are defined within the valve.

The chamber 14 communicates with the brake mask cylinder via a through hole 16 shown in dotted lines.

The other chamber 15 communicates via a through hole 17 with the brake of the rear wheel.

During braking, if the hydraulic pressure generated in the brake mask cylinder is below a predetermined value, the valve 9 is pushed by the spring force of the detection spring 4 as shown on the right side of FIG. 2, and its upper end touches the inner wall of the chamber 15. It is touching and stationary.

In this state, the valve portion 10 is separated from the seat 11 and opened, so that both chambers 14 and 15 are in communication.

By the way, when the pressurized liquid in the mask cylinder is supplied into the body 8 through the through hole 16, the pressure inside the body increases.

The valve 9 receives the hydraulic pressure inside the body 8 through the cross-sectional area of its shaft 12, and as a result, it slides against the plug 13 and is pushed out of the body 8.

The detection spring 4 opposes this pushing out.

The valve 9 is pushed out by hydraulic pressure and pushed into the body by the detection spring 4.

This pushing out and pushing in is repeated in a micro-vibratory manner with a stroke S, and as explained below, the opening and closing of the valve 10 is repeated in the same micro-vibrating manner, and an output is generated from the through hole 17 to brake the rear wheels. The hydraulic pressure supplied to the pump is controlled to a predetermined pressure increase rate.

18 is a seal, and 19 is a boot.

After the start of braking, the upper ends of both valves 9 are kept in contact with the inner surface of the chamber 15, like the right valve 9 in FIG. 2, until the inside of the body 8 reaches a predetermined pressure.

The reason why the left and right valves 9 in FIG. 2 occupy different positions is due to the operation of the detection spring 4 in the event of a failure, as will be described later.

During normal operation, both valves 9 perform the same operation.

However, using the state shown in Figure 2 at the time of failure,
The normal operation will be explained below.

When the brake pedal is depressed and the hydraulic pressure in the mask cylinder is supplied into the body 8 through the through hole 16, the pressure in the body increases.

This increased pressure is received by the cross section of the shaft 12 as described above, and each valve 9 receives a force that is pushed outward from the body while resisting the detection spring 4 together.

When the pressure rise reaches a predetermined value, both valves 9 change from the state where the valve part 10 was open like the valve 9 on the right to the state where the valve part 10 is closed like the valve 9 on the left. being pushed out.

When the valve part 10 is open like the valve 9 on the right side, the two way holes 16 and 17 are in communication, so the hydraulic pressure in the brake mask cylinder remains the same and is applied to the rear wheel brake without being restricted. is transmitted to brake the rear wheels.

Therefore, the pressure increase in the rear wheel brake is the same as the pressure increase in the brake mask cylinder until the predetermined value is reached.

After increasing the pressure to a predetermined value, the moment the valve portions 10 of both valves 9 close like the left valve, a pressure difference is created between the chambers 14 and 15 as described below.

The hydraulic pressure in the chamber 15 is applied to the entire area of the seal diameter of the seat 11.

On the other hand, the hydraulic pressure in the opposing chamber 14 is determined by the axis 12 from this total area.
Add to the annular area minus the cross-sectional area of .

In short, the hydraulic pressures in both chambers 14 and 15 are applied against different pressure-receiving areas, and the hydraulic pressures in both chambers are kept in balance.

As a result, the pressure in chamber 14 is higher than that in chamber 15, and the total pressure in both chambers is balanced.

In other words, the hydraulic pressure of the rear wheel brake is controlled to be lower than the hydraulic pressure in the mask cylinder.

However, the above-mentioned closed state is broken instantly.

That is, as long as the brake pedal continues to be depressed, the pressure in the chamber 14 continues to increase.

As a result, the hydraulic pressure in the chamber 14 overcomes the hydraulic pressure in the chamber 15, pushing each valve 9 upward in FIG.
Open the door.

By opening the valve, both chambers 14 and 15 communicate with each other, and both valves return to the state of the valve 9 on the right side of FIG. 2 again.

In this state, each valve 9 is again pushed back downward in the figure against the detection spring 4.

Therefore, like the valve 9 on the left, it returns to the closed state.

As long as the brake pedal continues to be depressed, the above-mentioned valve closing and opening are repeated in a micro-vibration manner, and the pressure inside the chamber 14 continues to rise.

During this time, the pressure in the chamber 15 also continues to increase, but the increase in pressure is compared to the increase in pressure in the chamber 14 and is controlled to the ratio of the above-mentioned receiving areas.

As explained above, the brake fluid pressure supplied to the rear wheel brakes of the automobile is restricted from rising above a predetermined value, thereby preventing the rear wheels from slipping due to forward movement of the center of gravity of the vehicle during braking.

Since the distance between the sprung portion 6 and the unsprung portion changes depending on the loaded load, the spring force of the detection spring 4 on each valve 9 also changes, and the braking hydraulic pressure is controlled in response to the loaded load.

The reason why a pair of valves 9 is provided in a dual arrangement as shown in FIG. 2 is for safety purposes.

This is because the brake hydraulic circuit is separated into two systems, and when one system is damaged, only the remaining circuit maintains braking safety.

Both valves 9 belong to separate hydraulic circuits.

The body 8 does not necessarily have to be one single body, but it is also possible to have one body for each P valve 7, but the assembly is shown in the figure for convenience of handling during work and other times. Adopts a single body format.

By the way, as mentioned above, the detection spring 4 can also be of a two-separate type, one for each P valve 7, but the assembly is handled at certain times, and the handling at other times is different. As shown in Figure 3, the dual system is easier to handle and more efficient.

However, a problem with such a detection spring 4 is that when the strokes of the valves 9 do not match, it is difficult to respond appropriately to each valve.

In extreme cases, stroke mismatch may occur if one of the hydraulic systems is damaged, or if it is due to part manufacturing tolerances.

FIG. 2 shows the state of each P valve when the hydraulic circuit to which the right valve 9 belongs is damaged.

Since the damaged hydraulic circuit loses hydraulic pressure, the right valve 9 is pushed by the detection spring 4 and remains at the rest position shown, and the left valve 9 receives input hydraulic pressure from the through hole 16 as shown. death,
A controlled output hydraulic pressure is delivered through the through hole 17.

In order to operate appropriately in the event of a failure as described above, the detection spring 4 of the present invention is provided with a partition hole 20 extending in the vertical direction to form left and right spring pieces 21 and 22, as shown in FIG. .

Both spring pieces 21 and 22 have eye portions 23 and 24 for pivoting at both ends.
are integrally connected.

According to the detection spring 4 of the present invention, it will be assembled later, and if the hydraulic circuit to which the right valve 9 belongs is damaged as shown in FIG. The rest position is maintained, and the left spring piece 22 causes the left valve 9 to perform the normal control operation as shown.

However, the left valve 9 can be operated without being affected by the right spring piece 21 as if both valves were operating normally.

Therefore, normally controlled hydraulic pressure is supplied to the rear wheel brake of the circuit to which the left valve 9 belongs, and braking safety is maintained.

Note that the same effect can be obtained even if the detection spring 4 of the present invention is separated so that the spring pieces 21 and 22 are completely separated from each other at the eye 24 as shown by the dotted line as shown in FIG.

[Brief explanation of drawings]

Figure 1 is a front view of the entire hydraulic pressure control device, and Figure 2 is a front view of the entire hydraulic pressure control device.
A cross-sectional view taken along the line ■-■ in the figure, and FIG. 3 is a partial perspective view. 1... Arm, 2... Hole, 3...
...Pin, 4...Detection spring, 5...Zen, 6...Spring upper part, 7...Hydraulic pressure flow portioning valve, 21, 22・・・・・・Spring piece.

Claims (1)

[Scope of utility model registration request] A plate-shaped detection spring has one end pivoted to the unsprung portion of the vehicle body and the other end to the sprung upper portion of the vehicle body, and the protruding end of the valve is arranged so as to abut and engage with a portion of the detection spring other than the above-mentioned two ends. In a control valve device having two hydraulic proportioning valves arranged in parallel, the above-mentioned detection spring is parallel to a long partition hole extending along its length, leaving at least its upper end. 1. A load-responsive braking hydraulic pressure control valve device for an automobile, which comprises long spring pieces, each of which abuts and engages the protruding ends of the two valves.