JPH08108837A - Antilock brake device - Google Patents

Abstract

PURPOSE: To enable a new rotary type control valve to be used by controlling to open/close a brake fluid passage according to relative positional relation of a sleeve and a piston, so as to obtain pressure reducing, pressure maintaining, and pressurizing conditions. CONSTITUTION: Because a rotary type control valve 10 is used as a solenoid valve used in an antilock brake device, pressure reducing, pressure maintaining, and pressurization in a wheel cylinder by antilock control can be controlled in a short time, in addition to pressure relaxation and quick pressurization of the brake, and pressurization delay at braking can be prevented. Further, this control valve 10 can be applied to any antilock brake device irrespective of a large-sized vehicle and an ordinary vehicle, and the antilock brake device can be more miniaturized. Furthermore, contact sound between a valve seat and a valve rod at opening/closing the passage can be removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antilock brake device, and more particularly to an antilock brake device which is small in size and employs a control valve with no pressurization delay.

[0002]

2. Description of the Related Art Conventionally, many modified examples of an antilock brake device have been known. For example, JP-A-6
The anti-lock brake device disclosed in Japanese Patent Application Laid-Open No. 127359 discloses a hydraulic pump 50, a reservoir 51, and a normally open hold valve 5 in a brake circuit as shown in FIG.
2. A normally closed decay valve 53 and the like are provided. During normal braking, the hydraulic pressure from the master cylinder is supplied to the wheel cylinders through the hold valve, and when the antilock control is started, the electronic control unit is started. The decay valve and the hold valve are opened and closed in response to a command from the hydraulic pressure pump 50, and at the same time as the hydraulic pressure pump 50 sucks the brake fluid from the reservoir 51, the brake pressure in the wheel cylinder is reduced, held, and increased to lock the wheels. Can be avoided.

[0003]

By the way, as the hold valve and the decay valve used in the conventional antilock brake device including the above device, a two-position switching type solenoid valve as shown in FIG. 7 is adopted. Therefore, the following problems have been pointed out. That is, since the two-position switching type hold valve used in the antilock brake device needs to realize the slow pressurization at the pressurizing rate in the brake pressurizing state during the antilock control, a valve having a throttle is used. Has been done. In other words, when a valve without a throttle is used, the brake pressure rises abruptly only by opening the valve for a short time during pressurization, and it is not possible to pressurize the brake slowly. For this reason, a valve having a throttle is used as the hold valve.

However, since the hold valve is normally provided in the brake circuit as described above, the brake fluid from the master cylinder is always supplied to the wheel cylinder through the hold valve even during the non-antilock control. (1) If there is a throttle in the hold valve, a pressurization delay occurs during normal braking. (2) Especially when the amount of brake fluid is large, as in a large vehicle, it is necessary to enlarge the passage of the hold valve in order to prevent delay in pressurization during normal braking. It inevitably grows. Also, such hold valves are too large to be applied to passenger cars. (3) When the entire hold valve becomes large, the entire antilock brake device becomes large as a result. (4) The contact noise between the valve seat and the valve rod when opening and closing the passage is large. There were problems such as. Therefore, an object of the present invention is to solve the above problems by using a novel rotary type control valve instead of the conventionally used two-position type solenoid valve.

[0005]

For this reason, the present invention provides an anti-lock brake system for controlling a brake fluid pressure in a wheel cylinder by a control valve according to a rotation state of a wheel, wherein the control valve is a sleeve, A piston disposed rotatably in the sleeve, and opening / closing control of the brake fluid passage by the relative positional relationship between the sleeve and the piston, so that depressurized, held, and pressurized states in the wheel cylinder can be obtained. The present invention is characterized in that it is used as a means for solving the problem.

[0006]

[Operation] [Normal braking] The brake fluid pressure generated in the master cylinder is changed from the connection port 1 to the first passage 1 of the sleeve 11.
2 → Hole 19 formed in the piston → Flow passage 18 formed in the center of the piston → Passage 21 → Supply to the wheel cylinder through the connection port 2 and brake is applied. In addition, when it is desired to reduce the pressurizing rate when the brake is operated, the servo motor is operated to rotate the piston 14, and the first flow path 12 and the throttle 20 formed in the piston are opposed to each other.
The brake can be operated in a state where the pressurization rate is small.

[During Antilock Control] When the wheels fall into the locked state during brake operation and the piston 14 is rotated by the servomotor to move to the state shown in FIG.
2, the communication between the second flow path 13 and the passage 21 is cut off, and the brake fluid pressure is maintained. When the piston 14 is in the state shown in FIG. 6B, the hole 19 of the piston 14 and the second flow passage 13 of the sleeve 11 communicate with each other, and as a result, the wheel cylinder → the passage 21.
→ The brake fluid pressure flows back to the flow path 18 in the piston → the hole 19 → the reservoir 4, and the pressure in the wheel cylinder is reduced to weaken the brake. When the piston 14 is in the state of FIG. 6C, the throttle 20 of the piston 14 and the second flow passage 13 of the sleeve 11 communicate with each other, and as a result, the wheel cylinder → passage 2
1 → flow passage 18 in piston 14 → throttle 21 formed in piston → second flow passage 13 of sleeve 11 → reservoir 4, and brake fluid pressure in the wheel cylinder is reduced at a low pressure reduction rate. The brake is weakened.
Further, when pressurization is required during antilock control, the piston 14 is moved to the state shown in FIG. 5A by the servo motor, and the liquid from the hydraulic pump is supplied to the wheel cylinder to operate the brake. You can

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an antilock brake device according to an embodiment of the present invention. The figure shows a brake piping system connecting the master cylinder and one wheel cylinder, and the piping systems for other wheel cylinders have the same configuration. Since the electronic control device for controlling the valve is the same as the conventional one, the description thereof will be omitted here.

In the figure, 1 is a connection port for connecting to a master cylinder, 2 is a connection port for connecting to a wheel cylinder, and a control valve 10 having a structure described later is provided in a flow path connecting the master cylinder 1 and the wheel cylinder 2. Is provided,
Further, a check valve 5 is arranged in the flow path that bypasses the control valve 10. A known hydraulic pump 3 is provided between the connection port 1 of the master cylinder and the control valve 10, and the suction port 3a of the hydraulic pump 3 is connected to the valve 10 and the reservoir 4. The discharge port 3b of the hydraulic pump 3 is a connection port 1 to the master cylinder.
It is connected to the. When the anti-lock control of the hydraulic pump 3 is started and a motor (not shown) is driven, the suction port 3a
The brake fluid can be sucked from the reservoir via the reservoir, or directly from the wheel cylinder via the control valve 10, and can be recycled to the master cylinder or to the wheel cylinder for repressurization. In addition,
Since the operation of the hydraulic pump and the opening / closing timing of the hold valve and the decay valve are conventionally known and are not the features of the present invention, detailed description thereof will be omitted here.

The structure of the control valve 10 will be described with reference to FIGS. 2 to 4. FIG. 2 is a plan sectional view of the control valve (FIG. 3).
3 is a sectional view taken along the line C-C in FIG. 3, FIG. 3 is a sectional view taken along the line AA in FIG. 2, and FIG. 4 is a sectional view taken along the line BB in FIG. In FIG. 2, the control valve 10 is provided with a cylindrical valve sleeve 11, in which the first passage 12,
The second passage 13 is formed. A piston 14 is liquid-tightly and rotatably provided in the valve sleeve 11, and an output shaft 16 of a servomotor 15 relatively rotates at one axial end of the piston 14 as shown in FIG. It is permanently attached. That is, the tip end portion of the output shaft 16 has a flat shape as shown in FIG. 4, and this portion fits into the slit formed in the piston 14 so that both cannot rotate. Further, a seal 17 is attached to a connecting portion between the output shaft 16 of the servo motor and the piston 14 to prevent leakage of brake fluid pressure. The servo motor 15 has a rotational position detection function, and controls the rotational amount of the piston 14 by this.

On the other hand, a flow passage 18 is formed in the central portion of the piston 14 in the vertical direction, and a hole 19 communicating with the flow passage 18 is formed at a position apart from the side wall of the piston 14 in the circumferential direction. The diaphragm 20 is formed so as to penetrate therethrough. The flow passage 18 is in constant communication with the wheel cylinder via a passage 21, and the hole 19 and the throttle 20 are connected.
Are provided at height positions corresponding to the first flow passage 12 and the second flow passage 13 formed in the sleeve 11. Therefore, for example, when the piston 14 rotates and the first flow passage 12 formed in the sleeve 11 and the hole 19 formed in the piston 14 face each other, the first flow passage 12 → hole 19 → flow passage 18 → passage 21
Communicates with. In this case, the diaphragm 20 is the sleeve 11
The flow path is closed by. Further, the first passage 12 formed in the sleeve 11 and the throttle 2 formed in the piston 14
If 0 corresponds, the first flow path 12 → diaphragm 20 → flow path 18
→ Communication with the passage 21. In this case hole 19 is sleeve 1
The flow path is closed by 1. In addition, piston 1
4 rotates, and the hole 19 and the second flow path 13 or the restrictor 20 and the second flow path 13 face each other, the passage 21 and the flow path 18 pass through the hole 19 or the restrictor 20 to generate the second flow. It communicates with the road 13.

The operation of the control valve having the above structure will be described in association with the antilock control. In this case, the first flow path 12 of the sleeve 11 is the connection port 1 with the master cylinder.
The second flow path 13 of the sleeve 12 communicates with the suction port 3 a of the hydraulic pump 3, and the flow path 18 of the piston 14 communicates with the connection port 2 with the wheel cylinder via the passage 21. [During Normal Braking] Since the piston 14 is located at the position shown in FIG. 5A, the brake fluid pressure generated in the master cylinder is generated by the connection port 1 → the first passage 12 of the sleeve 11 → the hole formed in the piston. 19 → Flow passage 18 formed in the center of the piston → Passage 21 → Supply to the wheel cylinder through the connection port 2 and brake is applied. Further, when it is desired to reduce the pressurization rate during brake operation, the servo motor is operated to rotate the piston 14 to the state shown in FIG. 5B, and the first flow path 12 and the throttle 20 formed in the piston are connected. Face each other. In this state, the brake fluid pressure generated in the master cylinder is changed from the connection port 1 to the first passage 12 of the sleeve 11.
→ Throttle 20 formed in the piston → Flow passage 18 formed in the center of the piston → Passage 21 → Supply to the wheel cylinder through the connection port 2, and the brake can be operated in a state where the pressurization rate is small. By rotating the piston as described above, the pressurization rate during normal braking can be changed. It should be noted that the pressurizing rate can be finely changed by forming a plurality of throttles on the side wall of the piston in which the diameter of the throttle 20 is changed little by little.

[During Antilock Control] When the wheels fall into a locked state during braking, a detection device (not shown) detects the locking of the wheels, and the electronic control device outputs a drive signal to the servomotor. The servomotor causes the piston 14 to move as shown in FIG.
In the state (a), the first flow path 12, the second flow path 13, and the passage 21 are disconnected from each other. That is, the communication between the wheel cylinder and the master cylinder and between the wheel cylinder and the reservoir is cut off, and the brake pressure at that time is held in the wheel cylinder. In this way, the brake fluid pressure holding state is obtained. After that, when the locked state of the wheels is still not avoided, the servo motor is driven again and the piston 14 is moved to the position shown in FIG.
In the state (b), the hole 19 of the piston 14 and the second flow path 13 of the sleeve 11 communicate with each other, and as a result, the brake fluid flows from the wheel cylinder → the passage 21 → the flow passage 18 in the piston → the hole 19 → the reservoir 4. The pressure returns. The brake fluid in the reservoir 4 is circulated to the master cylinder cylinder by the hydraulic pump that operates almost at the same time. In this way, the pressure in the wheel cylinder is reduced and the brake is weakened.

When the piston 14 is brought into the state shown in FIG. 6C by driving the servomotor, the throttle 20 of the piston 14 and the second flow passage 13 of the sleeve 11 communicate with each other, and as a result, the wheel cylinder → passage 21 → The brake fluid pressure recirculates from the flow passage 18 in the piston 14 to the throttle 21 formed in the piston to the second flow passage 13 of the sleeve 11 to the reservoir 4.
In this case, the brake fluid pressure in the wheel cylinder is reduced at a low pressure reduction rate, and the brake is weakened. Further, when pressurization is required during the antilock control, the communication between the hydraulic valve 10 and the master cylinder is cut off,
By setting the piston 14 in the state shown in FIG. 5A by the servomotor, the liquid from the hydraulic pump can be supplied to the wheel cylinder to operate the brake. As described above, according to the present invention, since the servomotor is used to control the rotary type control valve, it is possible to realize an antilock brake device having good responsiveness. In the control valve 10 described above, the first flow path formed in the sleeve is connected to the master cylinder, and the second flow path is connected to the reservoir side. However, the first flow path is connected to the reservoir and the second flow path is connected to the reservoir. The same effect can be obtained by connecting the path to the master cylinder side. Also, various shapes and numbers of the diaphragm 20 can be adopted.

[0015]

As described in detail above, according to the present invention,
Since a rotary type control valve is used as the solenoid valve used in the anti-lock brake device, it is possible to quickly and quickly pressurize the brake, and easily depressurize, hold and pressurize the wheel cylinder by anti-lock control in a short time. It is possible to prevent the delay of pressurization at the time of braking. Further, the present control valve can be applied to any antilock brake device regardless of whether it is a large vehicle or a normal vehicle, and the antilock brake device can be further downsized. Further, the contact noise between the valve seat and the valve rod when opening and closing the passage can be eliminated. It is possible to obtain excellent effects such as.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an anti-lock control device according to an embodiment of the present invention.

FIG. 2 is a plan sectional view of a control valve.

3 is a cross-sectional view taken along the line AA in FIG.

4 is a sectional view taken along line BB in FIG.

FIG. 5 is an explanatory view of the operation of the control valve at the normal time,
(A) is a figure which shows a normal state, (B) is a figure which shows the state which made the pressurization rate low.

6A and 6B are operation explanatory diagrams of a control valve during antilock control, in which FIG. 6A shows a hold state, FIG. 6B shows a large depressurization rate, and FIG. 6C shows a small depressurization rate. It is a figure.

FIG. 7 is a configuration diagram of a conventional antilock control device.

[Explanation of symbols]

 1 Connection Port to Master Cylinder 2 Connection Port to Wheel Cylinder 3 Hydraulic Pump 4 Reservoir 5 Check Valve 10 Control Valve 11 Sleeve 12 First Flow Path 13 Second Flow Path 14 Piston 15 Servo Motor 16 Servo Motor Output Shaft 18 Piston central flow path 19 Piston formed hole 20 Piston formed throttle

Claims (3)

[Claims] 1. An anti-lock brake system in which a brake fluid pressure in a wheel cylinder is controlled by a control valve in accordance with a wheel rotation condition, wherein the control valve includes a sleeve and a piston rotatably arranged in the sleeve. The anti-lock brake device is characterized in that the brake fluid passage is controlled to be opened / closed by the relative positional relationship between the sleeve and the piston, and pressure reduction, holding, and pressurization in the wheel cylinder can be obtained. . 2. The sleeve has a flow passage communicating with a master cylinder and a reservoir respectively, and the piston has a hole and a throttle which are always communicated with a wheel cylinder and can be connected to the flow passage of the sleeve. The antilock brake device according to claim 1, wherein the brake fluid pressure passage is opened and closed by controlling the rotational position. 3. The antilock brake device according to claim 2, wherein the control of the rotational position of the piston is performed by a servomotor.