JPH1071942A - Antilock brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of an abnormal sound and vibration by pulsation of brake pressure, and prevent leakage of the brake pressure by forming an expanding chamber in the middle of a fluid pressure circuit of an antilock brake device, and housing an elastic member in the expanding chamber. SOLUTION: In an expanding chamber 48 arranged in the middle of a fluid pressure circuit, a recessed part 49 is bored from an outer periphery of a housing 1a so as to expand a passage 12, and an opening part of the recessed part 49 is blocked up by a collar 50, a plug 51 and a nut 52. A seal groove is arranged on an outer periphery of the plug 51, and a part between the plug 51 and the recessed part 49 is sealed by a seal ring 57 installed in the seal groove, and airtightness of the expanding chamber 48 is secured. An elastic member 58 housed in the expanding chamber 48 is formed in a hollow spherical shape, and is held inside a hole formed in the plug 51. Therefore, the elastic member 58 housed in the expanding chamber 48 reduces and expands according to a change in brake fluid pressure, and can restrain pulsation of the brake fluid pressure. Even if the elastic member 58 is degraded with the lapse of time, sealing performance is not impaired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-lock brake device for controlling a brake hydraulic pressure of a vehicle.

[0002]

2. Description of the Related Art Conventionally, there is known an anti-lock brake device for controlling a brake fluid pressure of a vehicle in order to prevent a wheel from being locked during braking of the vehicle. This anti-lock brake device is provided in a master cylinder that generates brake fluid pressure in accordance with the pedaling force applied to a brake petal, a main passage that guides the brake fluid pressure of the master cylinder to a wheel cylinder, and provided in the middle of the main passage. A normally open inlet valve, a return passage communicating the wheel cylinder with the reservoir chamber, a normally closed outlet valve provided in the middle of the return passage, and a main passage for supplying the brake fluid in the reservoir to the main passage. A hydraulic circuit is constituted by a pump for refluxing the fluid.

If the wheels are likely to be locked during the braking operation by depressing the brake petal, the inlet valve is closed, the outlet valve is opened, and the brake fluid in the wheel cylinder is supplied to the reservoir via the return passage. When the brake fluid flows in, the brake fluid pressure is controlled to reduce the pressure to avoid locking the wheels.

More specifically, this antilock control is to reduce, maintain, and reduce the brake fluid pressure in order to obtain an optimal braking state.
The pressure increase is repeated. Therefore, the opening and closing operations of the inlet valve and the outlet valve are repeated. As a result, pulsation of the brake fluid occurs in the hydraulic circuit,
Noise and vibration may occur during antilock control.

As a countermeasure for this, there is a conventional hydraulic circuit in which a damper chamber is provided between a pump and a main passage.
The damper chamber is formed by fitting an elastic member to the open end of a damper recess formed from the outer surface of the housing of the antilock brake device.

In this conventional example, the elastic member in the damper chamber contracts and expands in accordance with a change in the brake fluid pressure in the hydraulic circuit, thereby suppressing the pulsation of the brake fluid and causing abnormal noise during antilock control. And vibrations are prevented.

A configuration similar to that of the conventional example is described in Japanese Patent Application Laid-Open No. 7-47946.

[0008]

However, in the conventional example, the damper chamber is formed by closing the opening of the damper recess formed in the housing by the elastic member. Thus, the sealing performance of the damper chamber may be impaired, and the brake fluid in the hydraulic circuit may leak out.

Further, in order to enhance the effect of suppressing the pulsation of the brake fluid, it is necessary to increase the volume of the elastic member. This increases the size of the damper chamber, which hinders miniaturization of the antilock brake device. I have.

The present invention has been made in view of the above-described situation, and is an anti-lock brake device capable of preventing generation of abnormal noise and vibration due to pulsation of brake fluid and preventing leakage of brake fluid. The primary purpose is to provide

It is a second object of the present invention to provide an antilock brake device which can prevent generation of abnormal noise and vibration due to pulsation of brake fluid in a hydraulic circuit and can be downsized. I do.

[0012]

In order to achieve the first object, the present invention is directed to a master cylinder which generates a brake hydraulic pressure in accordance with a depression force applied to a brake pedal, A main passage that guides the hydraulic pressure to the wheel cylinder, a normally-open inlet valve provided in the middle of the main passage, a return passage communicating the wheel cylinder with the reservoir, and a return passage provided in the middle of the return passage. In an anti-lock brake device comprising a normally closed type outlet valve and a pump for returning the brake fluid in the reservoir to the main passage, an expansion chamber is formed in the middle of the hydraulic circuit. Then, an elastic member is accommodated in the expansion chamber.

In the above configuration, during antilock control, the pressure reduction, holding, and pressure increase of the brake fluid pressure are repeated.
Further, for this reason, the opening and closing operations of the inlet valve and the outlet valve are repeated, and the brake fluid pressure in the hydraulic circuit changes, but the elastic member shrinks and contracts according to the change in the brake fluid pressure in the hydraulic circuit. By repeating the expansion, the pulsation of the brake fluid can be suppressed. Further, since the expansion chamber is sealed irrespective of the elastic member, even if the elastic member deteriorates with time, the sealing performance of the hydraulic circuit is not impaired.

Therefore, it is possible to prevent the generation of abnormal noise and vibration due to the pulsation of the brake fluid and to prevent the leakage of the brake fluid.

In order to achieve the second object,
According to the second aspect of the invention, in addition to the configuration of the first aspect,
The elastic member is formed in a hollow spherical shape. In this case, in addition to obtaining the same operation and effect as the first aspect of the present invention, the elasticity of the elastic member is increased by filling gas inside the elastic member. For this reason, even if the size of the elastic member is reduced, a sufficient pulsation suppressing effect of the brake fluid can be obtained, and the volume of the expansion chamber can be reduced.

Accordingly, the antilock brake device can be downsized.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of an antilock brake device showing an embodiment of the present invention. In the drawing, reference numeral 1 denotes an anti-lock brake device, and the anti-lock brake device 1 includes a master cylinder port 2 to which a master cylinder (not shown) is connected on the outer periphery of a housing 1a.
A wheel cylinder port 3 to which a wheel cylinder (not shown) is connected is formed. Further, inside the housing 1a, a hydraulic circuit 4 for communicating between the master cylinder port 2 and the wheel cylinder port 3 and controlling a brake hydraulic pressure transmitted from the master cylinder to the wheel cylinder is formed.

The hydraulic circuit 4 communicates between the master cylinder port 2 and the wheel cylinder port 3 and guides the hydraulic pressure of the master cylinder (not shown) to the wheel cylinder (not shown). 5, a normally open inlet valve 6 provided in the middle of the wheel cylinder port 2
, A return passage 8 communicating with the reservoir 7, a normally-closed outlet valve 9 provided in the middle of the return passage 8, and a pump 10 for returning the brake fluid in the reservoir 7 to the main passage 5. Have been.

The main passage 5 includes a passage 11 having one end opened to the master cylinder port 2, and a passage 12 having one end connected to the passage 11 and the other end opened to the wheel cylinder port 3. In the middle of the main passage 5, that is,
Between the passage 11 and the passage 12, an inlet valve housing hole 13 formed from the outer periphery of the housing 1a is formed, and the inlet valve 6 is housed in the inlet valve housing hole 13.

As shown in FIG. 2, the inlet valve 6 includes a cylindrical cylinder 15 having a solenoid 14 mounted on the outer periphery. One end 15a of the cylinder 15 is sealed with a cap 16 and the other end 15b is connected to a body. 17
Sealed by. The body 17 has a sliding hole 18 that communicates with the inside of the cylinder 15 and penetrates in the axial direction.
A flow path 19 orthogonal to the sliding hole 18 and communicating with the sliding hole 18 is provided. The flow path 19 communicates with the passage 12 with the inlet valve 6 housed in the inlet valve housing hole 13. A plug 21 having a flow path 20 communicating with the flow path 19 is inserted and fixed in the slide hole 18 on the upstream side of the flow path 19. The flow path 20 communicates with the passage 11 in a state where the inlet valve 6 is housed in the inlet valve housing hole 13.

An armature 22 that operates by controlling the power supply to the solenoid 14 is slidably inserted into the cylinder 15.

A plunger 23 operably connected to the armature 22 is slidably inserted into the sliding hole 18. This plunger 23 is armature 2
It comprises a body portion 24 on the second side and a small diameter portion 25 connected to the body portion 24 with a stepped portion 24a. The tip 25a of the small diameter portion 25 comes into contact with and separates from the plug 21 provided with the flow path 20, and It can be opened and closed. A compression spring 26 is provided between the step portion 24a and the spring seat 21a of the plug 21. The compression spring 26 urges the plunger 23 toward the armature 22 to open the flow path 20 in a normal state. Thus, the passage 11 and the passage 12 forming the main passage 5 are communicated with each other.

The reservoir 7 is formed by inserting a reservoir piston 32 into a recess 30 formed from the outer periphery of the housing 1a under the bias of a spring 31. The end of the spring 31 is supported by a plug 34 fixed to the opening end of the recess 30 by a snap ring 33.

The return passage 8 includes a passage 12, a passage 35 communicating with the passage 12 through the passage 19 of the inlet valve 6, and a passage 36 having one end communicating with the passage 35 and the other end opening to the reservoir 7. Consists of An outlet valve housing hole 37 formed from the outer periphery of the housing 1a is formed in the middle of the return passage 8, that is, between the passage 35 and the passage 36.
The outlet valve 9 is housed in the inside 7.

As shown in FIG. 2, the outlet valve 9 includes a cylindrical cylinder 39 having a solenoid 38 mounted on an outer periphery thereof. One end 39a of the cylinder 39 is sealed with a cap 40 and the other end 39b is connected to the body. 4
1 sealed. The body 41 is provided with a flow path 42 penetratingly formed in the axial direction. The flow path 42 communicates with the passage 36 with the outlet valve 9 housed in the outlet valve housing hole 37.

A plunger 43, which operates by controlling the power supply to the solenoid 38, is slidably inserted into the cylinder 39. The body 41 of this plunger 43
The side end is formed in a substantially conical shape, and forms a flow path 44 communicating with the flow path 42 between the body 41 and the body 41. The flow path 44 communicates with the passage 35 with the outlet valve 9 housed in the outlet valve housing hole 37. A spherical valve member 45 is attached to the center of the end of the plunger 43 on the body 41 side.
Are in contact with and separated from the body 41, and can open and close the flow path 42 of the body 41. The plunger 43 has a spring receiving hole 46 formed in the axial direction from the end of the cap 40 side, and a compression spring 47 is provided between the spring receiving hole 46 and the cap 40.
The compression spring 47 causes the plunger 4 to move.
3 is urged toward the body 41 side, and
Is closed, and the return passage 8 is shut off.

The pump 10 is provided in the middle of the passage 36, and a discharge port (not shown) of the pump communicates with the main passage 5 via a reflux passage (not shown).

Reference numeral 48 denotes an expansion chamber provided in the middle of the hydraulic circuit. The expansion chamber 48 has a recess 49 formed in the outer periphery of the housing 1a to expand the passage 12, and the opening of the recess 49 is formed with a collar 50. , Plug 51 and nut 52. The concave portion 49 has a large-diameter portion 53 on the opening side as shown in FIG.
The large diameter portion 53 has a thread groove 55 on the open end side. This recess 49
The collar 50 and the plug 51 are fitted into the large-diameter portion 53.
2 is screwed. As a result, the collar 50 and the plug 51 are sandwiched and fixed between the step 53a of the recess 49 and the nut 52. A seal groove 56 is provided on the outer periphery of the plug 51, and the space between the plug 51 and the concave portion 49 is sealed by a seal ring 57 mounted in the seal groove 56, and the airtightness of the expansion chamber 48 is secured. ing.

Reference numeral 58 denotes an elastic member housed in the expansion chamber 48. The elastic member 58 is formed in a hollow spherical shape, and is held inside a hole 59 formed in the plug 51.

A motor 60 is provided integrally with the housing 1a.
Is driven. Reference numeral 61 denotes a relay box that electrically connects the control unit of the antilock brake device 1 (not shown) and the motor 60.

In the anti-lock brake device 1 having the above-described structure, a master cylinder (not shown) generates a brake fluid pressure in accordance with a pedaling force applied to a brake pedal (not shown) of the vehicle. The brake fluid pressure generated in the master cylinder is guided to a wheel cylinder (not shown) through the main passage 5,
As a result, the wheels are braked. If the wheels are likely to lock during this braking operation, a control unit (not shown) of the anti-lock brake device 1 supplies a control current to the solenoid 14 of the inlet valve 6 to control the armature 22 and the plunger 23. When driven, the leading end 25a of the small diameter portion 25 of the plunger 23 closes the flow path 20 to shut off the main passage 5 and supplies a control current to the solenoid 38 of the outlet valve 9 to drive the plunger 43, 43 valve members 45
2, the return passage 8 constituting the return passage 8
5 and the passage 36. As a result, the brake fluid in the wheel cylinder flows out to the reservoir 7, and the brake fluid pressure decreases. The brake fluid stored in the reservoir 7 is
The pump 10 is operated by the suitable motor 60 and returned to a master cylinder (not shown).

Thereafter, when the locking of the wheels is avoided due to the decrease in the brake fluid pressure, the supply of the control current to the solenoid 38 of the outlet valve 9 is stopped, and the return passage 8
And shut off the brake fluid pressure.

When the brake fluid pressure drops and the braking force of the wheels becomes insufficient, the supply of control current to the solenoid 14 of the inlet valve 6 is cut off, and the plunger 23 of the inlet valve 6 cuts off the flow path. Open 20. As a result, the main passage 5 is connected again, and the high-pressure brake fluid from the master cylinder flows into the wheel cylinder again, and the brake fluid pressure increases.

As described above, the anti-lock brake device 1 reduces the brake fluid pressure during the anti-lock control.
Holding and increasing the pressure are repeated. In addition, the opening and closing operations of the inlet valve 6 and the outlet valve 9 are repeated, causing a change in the brake fluid pressure in the hydraulic circuit 4. The brake fluid pressure is accommodated in the expansion chamber 48 according to the change in the brake fluid pressure. Since the elastic member 58 contracts and expands, pulsation of the brake fluid can be suppressed.

Further, since the expansion chamber 48 is sealed irrespective of the elastic member 58, even if the elastic member 58 deteriorates with time, the sealing performance is not impaired.

Further, since the elastic member 58 is formed in a hollow spherical shape, gas is sealed inside the elastic member 58 and the elasticity of the elastic member 58 is increased. For this reason, even if the elastic member 58 is miniaturized, a sufficient brake fluid pulsation suppressing effect can be obtained, and the volume of the expansion chamber 48 can be reduced.

Therefore, it is possible to prevent the generation of abnormal noise and vibration during the antilock control and to prevent the leakage of the brake fluid. Also, by reducing the volume of the expansion chamber 48,
The miniaturization of the antilock brake device 1 becomes possible.

[0039]

As described in detail above, claim 1 is as follows.
According to the antilock brake device described above, it is possible to prevent generation of abnormal noise and vibration due to pulsation of the brake fluid during antilock control, and to prevent leakage of the brake fluid.

According to the antilock brake device of the second aspect, the same effect as that of the antilock brake device of the first aspect can be obtained, and the antilock brake device can be downsized.

[Brief description of the drawings]

FIG. 1 is a sectional view of an antilock brake device showing an embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG. 1 and is an enlarged view of a housing portion of an inlet valve and an outlet valve.

FIG. 3 is an enlarged view of a plug and an elastic member installed in the expansion chamber.

[Explanation of symbols]

 1 Anti-lock brake device. Reference Signs List 4 hydraulic circuit 5 main passage 6 inlet valve 7 reservoir 8 return passage 9 outlet valve 10 pump 48 expansion chamber 58 elastic member

Claims (2)

[Claims] A master cylinder for generating a brake fluid pressure in accordance with a depression force applied to a brake pedal; a main passage for guiding the fluid pressure of the master cylinder to a wheel cylinder;
A normally open inlet valve provided in the middle of the main passage, a return passage communicating the wheel cylinder to the reservoir, a normally closed outlet valve provided in the middle of the return passage, An anti-lock brake device comprising a hydraulic circuit constituted by a pump for returning the brake fluid to the main passage,
An anti-lock brake device, wherein an expansion chamber is formed in the middle of the hydraulic circuit, and an elastic member is accommodated in the expansion chamber. 2. The antilock brake device according to claim 1, wherein said elastic member is formed in a hollow spherical shape.