JP2504090B2 - Reflux type anti-skid device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a reflux type anti-skid device, and more particularly to reduction of operating noise of a pump.

Conventional technology The recirculation type anti-skid device is designed to keep the wheel slip properly by automatically controlling the hydraulic pressure of the brake cylinder. An example is given on pages 4-95, issued on January 21, 2000. This reflux type anti-skid device is provided in (a) a master cylinder, (b) a master cylinder reservoir that stores brake fluid under atmospheric pressure and supplies the brake fluid to the master cylinder, and (c) wheels. A state in which a brake cylinder of a brake, (d) a recirculation reservoir that stores brake fluid under a constant pressure, and (e) a master cylinder, a brake cylinder, and a recirculation reservoir are provided so that the brake cylinder communicates with the master cylinder. And (g) a pump that can switch the state of communicating with the recirculation reservoir to a state of communicating with the recirculation reservoir, and (f) a pump that pumps up the brake fluid discharged from the brake cylinder to the recirculation reservoir and returns it to the master cylinder side from the solenoid valve device. ) A rotation sensor that detects the rotation speed of the wheel, and (h) the solenoid valve device is switched based on the detection result of the rotation sensor. Controlled, and a skid control means maintain proper wheel slip.

In this anti-skid device, the pump is started during anti-skid control to return the brake fluid stored in the recirculation reservoir to the master cylinder.However, even when the anti-skid control is completed, the brake fluid remains in the recirculation reservoir. In some cases, the pump can be operated for a certain period of time even after the end of the anti-skid control because the pump may remain.

Problems to be Solved by the Invention Therefore, there is a problem that the operating noise of the pump causes noise. In particular, when the vehicle is stopped, the operating noise of other devices, such as the engine rotation noise, is reduced, so that it is inevitable that the operating noise of the pump is audibly noticeable.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention connects a recirculation reservoir and a master cylinder reservoir by a liquid passage, and provides an electromagnetic opening / closing valve in the liquid passage, and The electromagnetic on-off valve is provided with a solenoid on-off valve control means that is closed when the anti-skid control is performed and that is opened for at least a fixed time after the anti-skid control is completed.

Action and effect The brake fluid is stored under a constant pressure in the recirculation reservoir and at the atmospheric pressure in the master cylinder reservoir, so the electromagnetic fluid provided in the fluid passage that connects the recirculation reservoir and the master cylinder reservoir is stored. When the on-off valve is opened, the brake fluid in the recirculation reservoir will be naturally discharged to the master cylinder reservoir. Therefore, the brake fluid remaining in the recirculation reservoir can be returned to the master cylinder without opening the pump after the end of anti-skid control by opening the electromagnetic on-off valve for at least a certain time after the end of anti-skid control. Even after the skid control is finished, the pump is prevented from being operated and causing noise.

Since the electromagnetic on-off valve is closed during anti-skid control, the brake fluid discharged from the brake cylinder is stored in the recirculation reservoir as usual, and is returned to the master cylinder side by the pump from the solenoid valve device, Skid control is performed without any problems.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a system diagram of a hydraulic brake device equipped with a reflux type anti-skid device according to an embodiment of the present invention. In the figure, 8 is a brake pedal, and this pedal 8 operates a master cylinder 10. The master cylinder 10 includes two pressurizing chambers 12 and 14 independent of each other, and a master cylinder reservoir 16 that supplies brake fluid to the pressurizing chambers 12 and 14 is attached to the upper side thereof. This reservoir
The space inside 16 is in communication with the atmosphere, and the brake fluid is stored under atmospheric pressure.

The brake pedal 8 is pressed in the pressurizing chamber 1 based on the depression operation.
Generates the same level of hydraulic pressure on 2,14. The hydraulic pressure generated in one of the pressurizing chambers 12 is supplied to front wheel cylinders 22 and 24 of brakes provided on the left front wheel 18 and the right front wheel 20, respectively. The hydraulic pressure generated in the other pressurizing chamber 14 is the left rear wheel.
It is supplied to the rear wheel cylinders 30 and 32 of the brakes provided on the wheel 26 and the right rear wheel 28, respectively. This hydraulic brake device has a front and rear two-system type. The left and right front wheels 18 and 20 are steering wheels, and the left and right rear wheels 26 and 28 are drive wheels.

Electromagnetic control valves 36, 38 are provided in the middle of the main fluid passage connecting the pressurizing chamber 12 and the front wheel cylinders 22 and 24, whereby the main fluid passage serves as the master cylinder side passage 40 and the wheel cylinder side passage. It is divided into 42 and 44. Master cylinder side passage 40 and wheel cylinder side passage
Return passages 46 and 48 are respectively connected between the passages 42 and 44, and the flow of the brake fluid from the wheel cylinder side passages 42 and 44 to the master cylinder side passage 40 is connected to the return passages 46 and 48, respectively. Check valves 50, 52 are provided which allow but block reverse flow.

A recirculation reservoir 58 is connected to the electromagnetic control valves 36, 38 via reservoir passages 54, 56. In the housing 60 of the reservoir 58, a piston 62 is fitted in a liquid-tight and slidable manner, and a hydraulic chamber 64 connected to the reservoir passage 54 and an atmospheric pressure chamber 66 communicating with the atmosphere are formed. . A spring 68 is arranged in the atmospheric pressure chamber 66 to urge the piston 62, so that the brake fluid is stored in the hydraulic chamber 64 under a constant pressure.

The electromagnetic control valves 36, 38 are three-position directional control valves, and have a state in which the front wheel cylinders 22, 24 are in communication with the pressurizing chamber 12, a state in which they are in communication with the recirculation reservoir 58, and a state in which they are not in communication with any of them. Can be switched to. Solenoid control valve 3
6,38 constitute the solenoid valve device. When the front wheel cylinders 22 and 24 are in communication with the reservoir 58, the brake fluid discharged from the front wheel cylinders 22 and 24 is stored in the reservoir 58. Then, the brake fluid stored in the reservoir 58 is pumped up by the pump 74 having the check valves 70 and 72, and is supplied to the master cylinder side passage 40 via the pump passage 76.

The front system has been described above, but the rear system also has electromagnetic control valves 80, 82, master cylinder side passage 84, rear wheel cylinder side passages 86, 88, return passages 90, 92, check valve 94, as in the front system. , 96, reservoir passages 98, 100, recirculation reservoir 102, check valves 104, 106, and pump 108. However, the proportioning valve 110 is provided in the master cylinder side passage 84, and the hydraulic pressure generated in the pressurizing chamber 14 is reduced at a constant ratio to allow the rear wheel cylinder 3 to move.
Supplied to 0,32. Further, from the proportioning valve 110 of the passage 84 on the master cylinder side, the rear wheel cylinder 3
An electromagnetic opening / closing valve 112 is provided on the 0, 32 side.
By opening and closing the solenoid on-off valve 112, the rear wheel cylinder 30,
The valve 32 is switched between a state in which it communicates with the pressurizing chamber 14 and a state in which it is blocked, and the electromagnetic on-off valve 112 is opened during the anti-skid control.

The rotation speeds of the left and right front wheels 18, 20, and the left and right rear wheels 26, 28 are detected by the rotation sensors 116, 118, 120, 122, respectively, and the detection signals are supplied to the controller 124. The controller 124 calculates the slip ratio of each wheel based on the detection signals from these sensors, and controls the electromagnetic control valves 36, 38, 80, 82 based on the result.

The antiskid control of the system of the left front wheel 18 will be described representatively. When the depression force of the brake pedal 8 is low in relation to the friction coefficient of the road surface and the slip ratio of the left front wheel 18 is low, the controller 124 uses the electromagnetic force. As shown in the figure, the control valve 36 is maintained in a pressurization permitting state that allows the hydraulic pressure of the front wheel cylinder 22 to rise, and the brake fluid discharged from the pressurizing chamber 12 is supplied to the front wheel cylinder 22 to brake. It operates and brakes the left front wheel 18.

However, when the stepping force of the brake pedal 8 is large in relation to the friction coefficient of the road surface, the slip ratio of the left front wheel 18 increases beyond the appropriate range, so the controller 12
4 supplies current to the solenoid of the solenoid control valve 36 to make the solenoid control valve 36 in the cut-off state shown in the center of the figure or the pressure-decreasing permissible state shown on the right side (when the hydraulic pressure of the wheel cylinder decreases). The drive motor of the pump 74 is started while switching to the (allowable state).

When the electromagnetic control valve 36 is switched to the shutoff state,
The front wheel cylinder 22 is blocked from both the pressurizing chamber 12 and the recirculation reservoir 58 so that the hydraulic pressure is kept constant and the braking force on the left front wheel 18 is kept constant.
Further, when the electromagnetic control valve 36 is switched to the pressure reduction allowable state, the front wheel cylinder 22 causes the recirculation reservoir 58
The brake fluid is discharged from the front wheel cylinder 22 and stored in the reservoir 58 under a constant fluid pressure. The brake fluid stored in the reservoir 58 is pumped up by the pump 74 and returned to the master cylinder side passage 40.

In this way, the controller 124 switches the electromagnetic control valve 36 to an appropriate state among pressure increase, cutoff, and pressure decrease according to the slip ratio of the wheels, whereby the hydraulic pressure of the front wheel cylinder 22 is controlled within an appropriate range, The slip ratio of the left front wheel 18 is kept within an appropriate range. The controller 124 constitutes the control means for the anti-skid control, and the solenoid control valve 3
6,38,80,82, the recirculation reservoirs 58,102, the pumps 74,108, etc. constitute an anti-skid device.

The rear wheels 26, 28, which are the driving wheels, are subjected to acceleration slip control. Acceleration slip control is accumulator 130
Is used as a hydraulic pressure source. The accumulator 130 includes an electromagnetic opening / closing valve 112 and electromagnetic control valves 30, 82 in the master cylinder side passage 84.
The liquid passage 131 is connected to a portion between and via an electromagnetic opening / closing valve 132. The solenoid on-off valve 132 is closed during anti-skid control and opened during acceleration slip control. The brake fluid in the master cylinder reservoir 16 is pumped up by the pump 134 and stored in the accumulator 130 at high pressure.

The slip during acceleration of the rear wheels 26, 28 is the rotational speed of the rear wheels 26, 28 and the vehicle body speed (the rotational speed of the front wheels 18, 20 that are non-driving wheels).
It is detected based on and. When the rotation speed of the rear wheels 26, 28 is higher than the vehicle body speed, the slip state is present, and the slip state is eliminated by suppressing the rotation of the rear wheels 26, 28. When in the slip state, the controller 124 excites the solenoids of the solenoid on-off valves 112 and 132 to disconnect the rear wheel cylinders 30 and 32 from the pressurizing chamber 14, while
It communicates with the accumulator 130. As a result, the brake fluid is supplied from the accumulator 130 to the rear wheel cylinders 30 and 32, and the rotation thereof is suppressed, and the controller 124 either increases the pressure of the electromagnetic control valves 80, 82, shuts it down, or lowers it according to the slip state. Then, the rotation of the rear wheels 26, 28 is controlled to eliminate the slip state.

The brake fluid stored in the reservoir 102 is returned to the master cylinder reservoir 16 by switching the electromagnetic control valves 80 and 82 to the pressure-decreasing allowable state during the acceleration slip control. Therefore, the reservoirs 102 and 16 are connected by a liquid passage 136, and the liquid passage 136 is provided with an electromagnetic opening / closing valve 138. The opening / closing of the electromagnetic opening / closing valve 138 is controlled by the controller 124, and is closed during the anti-skid control so that the brake fluid in the reservoir 102 is pumped.
While being returned to the master cylinder side passage 84 by 08, it is opened during acceleration slip control. Reservoir 10
Brake fluid is stored under constant pressure in 2
Therefore, the brake fluid in the reservoir 102 is returned to the reservoir 16 when the electromagnetic opening / closing valve 138 is opened.

It should be noted that the accumulator 130 of the liquid passage 131 and the solenoid on-off valve 13
The portion between 2 and the portion of the liquid passage 136 on the reservoir 16 side of the electromagnetic opening / closing valve 138 are connected by the liquid passage 140. The fluid passage 140 is provided with a relief valve 142 so that the brake fluid is returned to the reservoir 16 when the fluid pressure of the accumulator 130 becomes abnormally high. In addition, a pressure sensor 144 is provided in the liquid passage 140 so that the accumulator 130 can store the brake liquid at an appropriate height.

In addition, the recirculation reservoir 58 of the front system is also connected to the liquid passage 15
0 is connected to the master cylinder reservoir 16. An electromagnetic opening / closing valve 152 is provided in the liquid passage 150, and opening / closing of the opening / closing valve 152 is controlled by the controller 124. The controller 124 also constitutes electromagnetic opening / closing valve control means.

In the hydraulic brake device configured as described above, when the slip of the wheel exceeds the set value during braking, anti-skid control is performed, and anti-skid control provided in the controller 124 is executed at the same time when the anti-skid control is started. Flag is set. In addition, the brake pedal 8
The above flag is reset when the depression of the vehicle is released or the anti-skid control ends when the vehicle speed falls below a certain low speed. At the same time, as shown in FIG. 2, the drive motors for the pumps 74 and 108 are driven. Is stopped, the solenoids of the electromagnetic control valves 36, 38, 80, 82 are demagnetized, and the electromagnetic opening / closing valves 152, 138 are excited for a certain period of time to cause the recirculation reservoirs 58, 102 to communicate with the master cylinder reservoir 16. As a result, if the brake fluid remains in the recirculation reservoirs 58, 102, the brake fluid will be stored in the fluid passage 15
Since it returns to the master cylinder reservoir 16 through 0, 136, the brake fluid can be returned regardless of the use of the pumps 74, 108.
It is avoided that the 4,108 is activated causing noise.

Further, in the hydraulic brake device of the present embodiment, a liquid passage 136 and an electromagnetic opening / closing valve 138 are provided for returning the brake fluid to the master cylinder reservoir 16 during the acceleration slip control. The brake fluid in the recirculation reservoir 102 can be returned to the master cylinder reservoir 16 by using the 136 and the electromagnetic opening / closing valve 138, and only the liquid passage 150 and the electromagnetic opening / closing valve 152 need be provided in the front system. The cost increase of the device can be suppressed to a low level.

In the above embodiment, the solenoid valve device is composed of the three-position directional control valve, but it may be composed of a combination of the electromagnetic opening / closing valve and the electromagnetic directional control valve, or may be composed of only the electromagnetic directional control valve. It is possible.

Further, in the above embodiment, the solenoid on-off valves 138, 152 are designed to be opened for a certain period of time after the end of the anti-skid control, but they may be opened at all times except during the anti-skid control.

In addition, although not exemplified, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a system diagram of a hydraulic brake device equipped with a reflux type anti-skid device according to an embodiment of the present invention. FIG. 2 is a time chart showing the control of the controller provided in the hydraulic brake device. 10: Master cylinder 16: Master cylinder reservoir 18: Left front wheel, 20: Right front wheel 22,24: Front wheel cylinder 26: Left rear wheel, 28: Right rear wheel 30,32: Rear wheel cylinder 36, 38: Electromagnetic control Valve, 58: Reflux reservoir 74: Pump, 80, 82: Electromagnetic control valve 102: Reflux reservoir, 108: Pump 116, 118, 120, 122: Rotation sensor 124: Controller, 136: Liquid passage 138: Electromagnetic on-off valve, 150: Liquid passage 152 : Solenoid valve

Claims (1)

(57) [Claims] 1. A master cylinder, a master cylinder reservoir for storing brake fluid under atmospheric pressure and supplying the brake fluid to the master cylinder, a brake cylinder for a brake provided on a wheel, and a constant pressure of the brake fluid. And a solenoid valve provided between the master cylinder, the brake cylinder, and the recirculation reservoir for switching between a state in which the brake cylinder communicates with the master cylinder and a state in which the brake cylinder communicates with the recirculation reservoir. Device, pump for pumping the brake fluid discharged from the brake cylinder to the recirculation reservoir and returning it to the master cylinder side from the solenoid valve device, rotation sensor for detecting the rotation speed of the wheel, and detection of the rotation sensor Based on the result, switching control of the solenoid valve device is performed, and slip of the wheel is adjusted. In a reflux type anti-skid device having positive anti-skid control means, the recirculation reservoir and the master cylinder reservoir are connected by a liquid passage, and an electromagnetic opening / closing valve is provided in the liquid passage, and A recirculation type anti-skid device, characterized in that the electromagnetic on-off valve is provided with an electromagnetic on-off valve control means that is closed when anti-skid control is performed and that is opened for at least a fixed time after the end of anti-skid control.