JPS6329638Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic pressure control device for controlling the rear wheel brake fluid of a two-system brake of an automobile, and more specifically, it includes a body and a pair of parallel brake fluids slidably housed within the body. A hydraulic pressure responsive piston, a pair of valves respectively linked to the pair of hydraulic pressure responsive pistons, and a coil spring that biases both hydraulic pressure responsive pistons in the valve opening direction via an equalizer guided by a guide rod. The present invention relates to an improvement of a hydraulic pressure control device equipped with a hydraulic pressure control device.

In this type of device, the tension of the coil spring affects the hydraulic control performance of the device.
It is desirable to be able to adjust and compensate for deviations from set values caused by dimensional tolerances of each component during assembly of the device. In this way, being able to adjust the tension of the coil spring when assembling the device means that the hydraulic control performance of the device can be changed, and costs can be reduced by sharing parts between devices with different hydraulic control performance. It is desired from the point of view.

However, the conventional device is not configured to be able to adjust the tension of the coil spring. The purpose of the present invention is to enable the tension of the coil spring to be adjusted to an arbitrary value.One end of the coil spring is locked to one end of a guide rod, and the other end of the guide rod is formed with a male thread. A female thread that threadably engages with the male thread is formed on the body so that the coil spring is compressed as the threaded engagement progresses, and a tightening allowance is provided between the female thread and the male thread so that the friction between the two causes the coil spring to be compressed. The gist is that it is fixed at an arbitrary relative position.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the body 10 has one brake system port 11 and a wheel cylinder connection port 12.
and the other brake system master cylinder connection port 1
3 and a foil cylinder connection port 14, a cylinder hole 15 communicating with the master cylinder connection port 11 and the foil cylinder connection port 12, and a cylinder hole 16 communicating with the master cylinder connection port 13 and the foil cylinder connection port 14 are formed. There is. The cylinder hole 15 accommodates a hydraulic responsive piston 20 which is integrally formed with a cup-shaped valve seat 17 and a valve body 19 that constitutes a valve 18 with the valve seat 17 . Also,
A hydraulic response piston 24 is housed in the cylinder hole 16 and is integrally formed with a valve body 23 that forms a valve 22 together with a cup-shaped valve seat 21 . Hydraulically responsive pistons 20, 24 are parallel to each other and their right ends project through plugs 25, 26 and retainer 27 into cover 28. The guide rod 30 in the air chamber 39 in the cover 28 has a male thread 31 formed at its left end, and this male thread 31 threadably engages with a female thread 32 formed in the body 10.
The guide rod 30 is fixed to the body 10 by this threaded engagement. An equalizer 33 is slidably supported on the guide rod 30, and a coil spring 36 is stretched between the equalizer 33 and a retainer 35 that is in contact with the guide rod head 34. The pressure-responsive pistons 20, 24 are biased to the left, that is, in the direction of opening the valves 18, 22. A gap is provided between the sliding portion of the equalizer 33 and the guide rod 30 to allow the equalizer 33 to swing by a predetermined amount. This rocking of the equalizer 33 is caused by the hydraulic response pistons 20 and 24
It does not allow movement to the right until it is closed.

In order to adjust the tension of the coil spring 36 to an arbitrary value, the male thread 31 of the guide rod 30 has a second
~ As shown in Figure 4, the left triangular screw portion 31a,
The right trapezoidal thread portion 31b has a root diameter _D2 larger than the root diameter _D1 of the triangular screw portion 31a. On the other hand, the female thread 32 of the body is a triangular thread having the same effective diameter as the triangular thread portion 31a of the male thread 31. Therefore, a tightening margin exists between the trapezoidal thread portion 31b of the male thread 31 and the female thread 32. The triangular threaded part 31a of the male thread 31 is for facilitating the screwing operation of the male thread 31 into the female thread 32. If the screws are stopped at this stage, the trapezoidal screw portion 31b and the female screw 32 are fixed by friction between the two due to the tightness between them. Therefore, the tension of the coil spring 36 can be adjusted as desired during the assembly process of the device.

In the hydraulic control device configured as described above, when the brake is not applied, the hydraulic response pistons 20 and 24 are prevented from moving leftward by the body 10 due to the tension of the coil spring 36, and when the valves 18 and 22 are open, It is held in the position shown in Figure 1. During braking, each hydraulic pressure responsive piston 20, 24 is biased to the right by hydraulic pressure, and this biasing force is the biasing force of the coil spring 36 (1/2 tension of the coil spring 36).
When this is overcome, the liquid response pistons 20, 24 move to the right and the valves 18, 22 close. The fluid pressure at this time is generally called the break point fluid pressure. Thereafter, since the effective sealing diameter of the valve bodies 19, 23 is larger than the diameter of the fitting portion of the hydraulic pressure responsive plungers 20, 24 to the plugs 25, 26, the hydraulic responsive plungers 2
0 and 24 reciprocate as the pressure of the master cylinder connection ports 11 and 13 increases, opening and closing the valves 18 and 22, and the hydraulic pressure of the wheel cylinder connection ports 12 and 14 becomes the hydraulic pressure of the master cylinder connection ports 11 and 13. On the other hand, the pressure is reduced at a constant ratio and the pressure is increased while being controlled to a certain value.

The above is the operation when both brake systems are normal, but when one brake system is defective,
The rightward movement of the hydraulic response piston 20 or 24 (in FIG. 1) due to the normal hydraulic pressure of the other brake system resists the tension of the coil spring 36, so that the hydraulic pressure at the turning point is normal for both brake systems. This is twice the value compared to the original brake system, and compensates for the lack of braking force due to a defect in one brake system.

In one embodiment described above, the body 10
The female thread 32 of the guide rod 30 is a triangular thread with a single effective diameter, and the male thread of the guide rod 30 is composed of a triangular thread part 31a with the same effective diameter as the female thread 32 and a trapezoidal thread part 31b with a larger effective diameter. 31
Although a tightening allowance was provided between b and the female thread 32, the male thread 3
1 is a single effective triangular thread, and female thread 32
This can be implemented by comprising a right triangular thread portion having the same effective diameter as the male thread 31 and a left trapezoidal thread portion having a smaller effective diameter. Also, connect the male thread 31 of the guide rod 30 to the equalizer 33.
The guide rod 30 is fixed to the body 10 by engaging the male screw 31 with the female screw of the body 10 until the step between the male screw 31 and the guide portion comes into pressure contact with the body 10. It is possible to replace the portion 34 with a nut that threadably engages the guide rod 30, and to form the female thread of this nut and the male thread of the guide rod in the same manner as the male thread 31 and the female thread 32 of FIG. Furthermore, when such a nut is provided, the tension of the coil spring is equally divided into two by reducing the gap between the sliding parts of the equalizer and the guide rod and pivoting the guide rod to the body so that it can swing by a predetermined amount. It can be implemented in such a way that it can be applied to individual hydraulically responsive pistons.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of one embodiment of the present invention, FIG. 2 is a view showing a guide rod, and FIGS. 3 and 4 are views of the second embodiment.
FIG. 1 is a partially enlarged view of the figure.
8, 22 ... valve; 20, 24 ... hydraulic response piston;
30: guide rod; 31: male thread; 32: female thread; 33: equalizer; 36: coil spring.

Claims (1)

[Scope of utility model registration request] a body, a pair of hydraulic response pistons that are slidably housed in the body and are parallel to each other, a pair of valves that respectively operate in conjunction with the pair of hydraulic response pistons, and an equalizer that is guided by a guide rod. In a two-system brake hydraulic control device comprising a coil spring that biases both hydraulic response pistons in the opening direction of the valve, one end of the coil spring is locked to one end of the guide rod, and one end of the coil spring is locked to one end of the guide rod. A male thread is formed at the other end, a female thread that engages with the male thread is formed in the body so that the coil spring is compressed as the threaded engagement progresses, and further between the female thread and the male thread. A hydraulic pressure control device for a two-system brake that fixes both at an arbitrary relative position by applying a tightening margin and using friction between the two.