JPS63159169A - Wheel lock preventing device - Google Patents

Abstract

PURPOSE:To prevent a driver from feeling unpleasant, by a method wherein a power- liquid pressure feed source and a regulator valve are situated, an opening closing switching valve is located in a brake liquid pressure circuit, and a brake liquid pressure is introduced through a check valve to a brake liquid pressure circuit situated between the opening closing switching valve and a feed discharge switching valve. CONSTITUTION:Under an antiskid working state, a regulator valve 60 regulates a liquid pressure, fed from a power liquid pressure feed source 70 based on liquid pressure in a master cylinder 12 or a pressure equivalent thereto, serving as a reference pressure, to a regulator liquid pressure approximately equivalent to a reference value to output it. A liquid pressure (a regulator liquid pressure) from the regulator valve is repeatedly and intermittently fed to a wheel cylinder through the switching action of feed discharge switching valves 31, 33, and 35, where occasion demands. Therefore, although a regulator liquid pressure itself is sometimes fluctuated, since the regulator liquid pressure is not used for assisting working of the master cylinder 12, a fluctuation in working of the master cylinder is prevented from occurring due to a fluctuation in the regulator liquid pressure and a driver is prevented from feeling unpleasant due to pedal vibration.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wheel lock prevention device, a so-called anti-skid device. a supply/discharge switching valve that is switched in response to a signal from a control device that detects the hydraulic pressure applied to the wheel cylinder by connecting the wheel cylinder to a reservoir or the master cylinder; This invention relates to a wheel opening prevention device that prevents wheel locking that may occur when braking a vehicle.

[Conventional technology]

In this type of wheel lock prevention device, the operation of the master cylinder can be assisted by a hydraulic servo motor, and the supply/discharge switching valve is connected to a brake hydraulic circuit connecting the master cylinder and the supply/discharge switching valve. In the anti-skid operating state, the connection between the supply and exhaust switching valve and the master cylinder is disconnected and the normal state (anti-skid non-operating state) is established.
Then, an on-off switching valve connecting the supply/discharge switching valve and the master cylinder is provided, and fluid from the hydraulic servo motor is supplied via a check valve into the brake hydraulic circuit between the on-off switching valve and the supply/discharge switching valve. A device designed to guide pressure was developed in 1986.
This is proposed in Publication No.-10219.

[Problem that the invention seeks to solve]

In the conventional device described above, when the anti-skid is in operation, the on-off switching valve disconnects the supply/discharge switching valve from the master cylinder, and the hydraulic pressure led from the hydraulic servo motor via the check valve switches the supply/discharge switching. As the wheel cylinders are repeatedly and intermittently supplied to the wheel cylinders as needed by the valve switching operation, the hydraulic medium remains in the pressure chamber of the master cylinder without being consumed, which is an advantage. Large pressure fluctuations occur due to the intermittent supply of hydraulic pressure to the assisting hydraulic servo motor, which causes fluctuations in the operation of the master cylinder, induces pedal sickness (vibration) in the brake pedal, and causes discomfort to the driver.

[Means for solving problems]

The present invention has been made in order to solve the above-mentioned problem, and has a brake fluid pressure circuit connecting a master cylinder and a wheel cylinder that is switched in response to a signal from a control device that detects a locked state of a wheel. A wheel lock prevention device that is provided with a supply/discharge switching valve that controls the hydraulic pressure applied to the wheel cylinder by connecting a cylinder to a reservoir or the master cylinder to prevent wheel lock that may occur when braking a vehicle. A power hydraulic pressure supply source whose hydraulic medium is the same as the hydraulic medium in the brake hydraulic pressure circuit is attached, and the hydraulic pressure in the master cylinder or a pressure equivalent thereto is set as a reference pressure and the power supply source is set as a reference pressure. A brake fluid pressure circuit is provided with a regulator valve that adjusts the fluid pressure supplied from the fluid pressure supply source to a regulator fluid pressure substantially equal to the reference pressure and outputs the same, and also connects the master cylinder and the supply/discharge switching valve. An on-off switching valve is interposed which disconnects the supply/discharge switching valve from the master cylinder in an anti-skid operating state in which the supply/discharge switching valve switches and operates, and connects the supply/discharge switching valve and the master cylinder in a normal state; The present invention is characterized in that the regulator hydraulic pressure output from the regulator valve is introduced into the brake hydraulic pressure circuit between the on-off switching valve and the supply/discharge switching valve via a check valve.

[Effect]

In the wheel lock prevention device according to the present invention, in a normal state (a state in which anti-skid is not activated), the on-off switching valve connects the supply/discharge switching valve and the master cylinder, and when the supply/discharge switching valve is in an inactive state, the wheel cylinder Since it is connected to the on-off switching valve, and at this time, the hydraulic pressure in the brake hydraulic pressure circuit between the on-off switching valve and the supply/discharge switching valve is approximately equal to the hydraulic pressure in the master cylinder, and the regulator valve It is approximately equal to the regulator fluid pressure output from the
Since pressure fluid does not flow out or flow in through the check valve, the fluid pressure in the master cylinder caused by pressing the brake pedal is transmitted to the wheel cylinders via the hydraulic pressure switching valve and the supply/discharge switching valve, and normally braking action can be obtained.

In addition, when a locked state of the wheels is detected in the braking state described above and the supply/discharge switching valve is switched in response to a signal from the control device, the on-off switching valve is switched to the supply/discharge switching valve at the same time or prior to this. In order to disconnect the master cylinder and allow the regulator hydraulic pressure output from the regulator valve to be introduced into the supply/discharge switching valve, the wheel cylinder is connected to the reservoir by the switching operation of the supply/discharge switching valve to reduce the hydraulic pressure. The pressure may be increased by the regulator fluid pressure introduced through the check valve. This prevents wheel locking that may occur when braking the vehicle, and the vehicle is appropriately braked.

By the way, in the anti-skid operating state where the above-mentioned supply/discharge switching valve switches, the on-off switching valve disconnects the supply/discharge switching valve from the master cylinder, so the hydraulic medium is consumed in the pressure chamber of the master cylinder. This has the advantage that it remains unaffected. In addition, in the same anti-skid operating state, the hydraulic pressure in the master cylinder or a pressure equivalent thereto is used as a reference pressure, and the hydraulic pressure supplied from the power hydraulic pressure supply source is regulated to a regulator hydraulic pressure that is approximately equal to the reference pressure. The output hydraulic pressure from the regulator valve (regulator hydraulic pressure) is repeatedly and intermittently supplied to the wheel cylinder as needed by the switching operation of the supply/discharge switching valve, so the regulator hydraulic pressure itself may fluctuate. Since this regulator fluid pressure is not used to assist the operation of the master cylinder, the master cylinder operation will not fluctuate due to fluctuations in the regulator fluid pressure, causing discomfort to the driver via the brake pedal. will not be given.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a first embodiment of the present invention, in which the front pressure chamber of a tandem brake master cylinder (hereinafter simply referred to as master cylinder) 12 operated by a brake pedal 10 and a hydraulic booster 11 is shown in FIG. The left and right front wheel brake cylinders (
(hereinafter simply referred to as wheel cylinders) 21.22, and the rear pressure chamber of the master cylinder 12 is connected to the left and right rear wheel cylinders 23.22 through the rear brake fluid pressure circuit.
24 shows a wheel lock prevention device that is applied to a vehicle connected to a wheel cylinder 24 to independently control the hydraulic pressure applied to each wheel cylinder 21, 22, 23, and 24. Note that a known proportioning valve 19 is interposed in the rear brake hydraulic circuit.

The wheel lock prevention device includes a supply/discharge switching valve 31. which is provided in the brake fluid pressure circuit P1 leading to the left front wheel cylinder 21. A slow/slow switching valve 32 and a supply/discharge switching valve 33 provided in the brake fluid pressure circuit P2 leading to the front right wheel cylinder 22. Slow/slow switching valve 3
4, and a supply/discharge switching valve 35.4 provided in the brake hydraulic pressure circuit P3 leading to the left and right rear wheel cylinders 23.24. Slow feed switching valve 3
6, sensors 41, 42, 43, 44 that detect the rotational speed of each wheel, a switch 45 that detects the depression of the brake pedal 1o, and a switch 45 that is activated by the operation of the switch 45 when the brake pedal 10 is depressed. Sensor 41~
44 to detect the locked state of each wheel (amount of change in wheel speed) and prevent each wheel from locking appropriately (a microcomputer 50 is provided as a control device that issues a signal to each switching valve 31 to 36). The wheel lock prevention device also includes a brake fluid pressure circuit P4 that connects both brake fluid pressure circuits PI and P2 to the front pressure chamber of the master cylinder 12.
an on-off switching valve 37 provided in the brake hydraulic pressure circuit P5 that connects the brake hydraulic pressure circuit P3 to the rear pressure chamber of the master cylinder 12;
．． Check valves Vl and V2 are interposed in the hydraulic pressure circuit between 38 and each supply/discharge switching valve 31, 33.35, and the regulator valve 6 supplies the regulator hydraulic pressure through the hydraulic pressure circuit P6.
0, and a hydraulic circuit P7.0 to the hydraulic booster 11 and regulator valve 60. A power hydraulic pressure supply device 7o is provided for supplying power hydraulic pressure through P8.

Each supply/discharge switching valve 31, 33.35 is an electromagnetic switching valve,
During demagnetization, each wheel cylinder 21, 22, 23, 24
are connected to each on-off switching valve 37, 38, and each wheel cylinder 21, 22, 23, 24 is connected to a reservoir 12A attached to the master cylinder 12 during excitation. Each speed changeover valve 32, 34, 36 is connected to each wheel cylinder 2.
1.22.23.24 and each supply/discharge switching valve 31, 33.35
It is an electromagnetic switching valve interposed between each wheel cylinder 21, 22, 23, 24 and each supply/discharge switching valve 31,
33.35 are communicated without throttling, and during excitation, each wheel cylinder 21, 22° 23.24° and each supply/discharge switching valve 31, 33, 35 are connected to each throttle 32a, 34a, 36a.
communicate through.

Each on-off switching valve 37, 38 is an electromagnetic switching valve, and when demagnetized, each hydraulic pressure circuit Pi, P2. P3 to each hydraulic pressure circuit P4. P
5 so that the master cylinder hydraulic pressure is introduced into each supply/discharge switching valve 31, 33, 35, and when energized, each hydraulic pressure circuit Pi, P2 . P3 to each hydraulic pressure circuit P4. Cut off from P5. Therefore, the switching operation (demagnetization) of each on-off switching valve 37, 38 is performed.

Excitation) is controlled by the microcomputer 50 together with the switching operation of each switching valve 31 to 36, and when the amount of decrease in wheel rotational speed per unit time during vehicle braking exceeds a set value, each switching valve 31 In the anti-skid operating state in which the switching valves 31 to 36 are activated simultaneously with or prior to the switching operation (repetition of demagnetization and excitation) of 36 to 36, the master cylinder hydraulic pressure is applied to each supply/discharge switching valve 31, 33, and 35. In order to prevent this from being introduced, the supply/discharge switching valves 31, 33. are demagnetized (in normal conditions) at times other than the above.
35 so that the master cylinder hydraulic pressure is introduced.

As shown in FIGS. 1 and 2, the regulator valve 60 receives hydraulic pressure from the hydraulic booster 11 through a hydraulic circuit P9 including a throttle 0 (this hydraulic pressure is applied to the operation of the master cylinder 12). The power hydraulic pressure applied from the power hydraulic pressure supply device 70 through the hydraulic pressure circuit P8 is approximately equal to the master cylinder hydraulic pressure. It adjusts the pressure to the regulator hydraulic pressure and outputs it to the hydraulic pressure circuit P6, and includes a housing 61 having four boats, and the housing 6
1. Piston 62. It is composed of a valve 63 and a check valve 64.

The piston 62 has a liquid chamber R communicating with the hydraulic circuit P9 on both sides.
1 and forms a liquid chamber R2 communicating with the hydraulic pressure circuit P6,
A passage 62 in which the liquid chamber R2 can be communicated with the return circuit PIO
It has a. The valve 63 is connected to the passage 6 of the piston 62.
The through hole 63 is integrally provided with a ball 63a that can open and close the check valve 2a and a rod 63b that can open and close the check valve 64.
It is equipped with c. ” In such a regulator valve 60, when the liquid pressure in the liquid chamber R1 becomes higher than the liquid pressure in the liquid chamber R2, the piston 62 is pushed to the right in the figure and pushes the valve 63 (at this time, the piston 62 (the passage 62a is closed by the ball 63a), the rotor 3 pushes open the check valve 64, the power hydraulic pressure flows into the liquid chamber R2 through the through hole 63c, and the hydraulic pressure in the liquid chamber R2 increases. is obtained, and when the liquid pressure in the liquid chamber R2 becomes higher than the liquid pressure in the liquid chamber R1,
The piston 62 is pushed to the left in the figure to open the passage 62a (at this time, the check valve 64 is closed), and the liquid chamber R2 is opened.
The liquid pressure in the liquid chamber R2 is discharged to the return circuit P10 through the passage 62a and returned to the reservoir 12A, and the liquid pressure in the liquid chamber R2 is reduced, and the liquid pressure in the liquid chamber R2 (regulator liquid pressure ) is always regulated to be approximately equal to the liquid pressure in the liquid chamber R1.

The power hydraulic pressure supply device 70 generates power hydraulic pressure and supplies hydraulic medium (
The hydraulic medium is the same as brake fluid), and is composed of a hydraulic pump 72 driven by an electric motor 71, a check valve 73, an accumulator 74, etc., and the hydraulic pressure of the hydraulic booster 11 is It also serves as a source. In this power hydraulic pressure supply device 70, starting and stopping of the electric motor 71 are controlled by the microcomputer 50 in accordance with the pressure inside the achievator 74.
When the hydraulic pressure in the accumulator 74 falls below the set value, the electric motor 71 starts and the hydraulic pump 7
2, and when the hydraulic pressure in the accumulator 74 exceeds the set value, the electric motor 71 stops and the hydraulic pump 7
2 is stopped.

In this embodiment configured as described above, in the normal state (state in which anti-skid is not activated), each on-off switching valve 37, 38 is demagnetized and each supply/discharge switching valve 31 is demagnetized, as shown in FIG. .33.35, the master cylinder hydraulic pressure is introduced, and each switching valve 31-36 is in an inoperative state (demagnetized state),
4 is connected to each on-off switching valve 3C38, and at this time, each on-off switching valve 37.38 and supply/discharge switching valve 31
．． The hydraulic pressure in the brake hydraulic pressure circuit between 33 and 35 is approximately equal to the master cylinder internal hydraulic pressure, and is approximately equal to the regulator hydraulic pressure output from the regulator valve 60, and each check valve ■1 , brake pedal 1 because there is no pressure fluid flowing out or flowing in through V2.
The hydraulic pressure in the master cylinder 12 generated by depressing the wheel is transferred to each wheel cylinder 21 to 21 through each switching valve 31 to 38.
24, and normal braking action is obtained.

In addition, the microcomputer 50 detects the locked state of each wheel in the braking state, and responds to a signal from the microcomputer 50 to control the switching valves 31 to 36.
When the switching operation is performed, at the same time or prior to this, each on-off switching valve 37, 38 is energized and the connection between each switching valve 31 to 36 and the master cylinder 12 is cut off, and each supply/discharge switching valve 31, 3
In order to introduce the regulator hydraulic pressure output from the regulator valve 60 at 3.35, each wheel cylinder 21 to 24 is connected to the reservoir 12A by energizing each supply/discharge switching valve 31, 33, and 35. The hydraulic pressure is reduced, and the hydraulic pressure is increased by the regulator hydraulic pressure introduced through each check valve V], V2 by demagnetizing each supply/discharge switching valve 31, 33.35,
When the hydraulic pressure is reduced or increased, each of the slow/sudden switching valves 32, 34.
The pressure is slowly decreased or increased by the excitation of 36.

As a result, locking of each wheel that may occur when braking the vehicle is optimally prevented, and the vehicle is appropriately braked.

By the way, in the anti-skid operating state in which the above-mentioned switching valves 31 to 36 switch, each on-off switching valve 37, 38
Since the switching valves 31 to 36 are disconnected from the master cylinder 12, there is an advantage that the hydraulic medium remains in both pressure chambers of the master cylinder 12 without being consumed. In addition, in the same anti-skid operating state, the regulator valve 60
The regulator hydraulic pressure from each supply/discharge switching valve 31, 33.3
5 is repeatedly and intermittently supplied to each wheel cylinder 21 to 24 as needed, so the regulator hydraulic pressure itself may fluctuate, but this regulator hydraulic pressure assists the operation of the master cylinder 12. Since it is supplied only to each wheel cylinder 21 to 24 without being used for the purpose of It does not cause any discomfort.

FIG. 3 shows a second embodiment of the present invention, in which a well-known negative pressure booster IIA is adopted in place of the hydraulic booster 11 of the first embodiment, and FIGS. The regulator valve 80 shown in FIGS. 3 and 4 is used in place of the regulator valve 60 shown in FIG.

The regulator valve 80 connects the hydraulic circuit P5 to the hydraulic circuit pH.
The power hydraulic pressure applied from the power hydraulic pressure supply device 90 through the hydraulic pressure circuit P12 is regulated to a regulator hydraulic pressure approximately equal to the master cylinder hydraulic pressure using the master cylinder hydraulic pressure applied through the power hydraulic pressure supply device 90 as a reference pressure, and the power hydraulic pressure applied through the hydraulic pressure circuit P12 is adjusted to the hydraulic pressure circuit P6. A housing 81 having four ports, and a piston 82 built into the housing 81. valve 83
and a spring 84.

The piston 82 has a hydraulic chamber R3 communicating with the hydraulic circuit Pil and a hydraulic pressure R4 communicating with the hydraulic circuits P6 and PI3 on both sides, and is biased toward the hydraulic chamber R4 by a spring 84. It has a passage 82a therein that allows the liquid chamber R4 to communicate with the return circuit PLO. The valve 83 is integrally provided with a ball 83a that can open and close the passage 8'2a of the piston 82, and is immovably assembled within the housing 81.

In such a regulator valve 80, when the liquid pressure in the liquid chamber R4 becomes higher than the sum of the liquid pressure in the liquid chamber R3 and the pressure due to the biasing force of the spring 84 (which is extremely small), the piston 82 moves as shown in the figure. The piston 82 is pushed to the left.
Since the passage 82a of the liquid chamber R4 is opened, the liquid pressure in the liquid chamber R4 is discharged to the return circuit PLO through the passage 82a and is discharged to the reservoir 1.
2△, the liquid pressure in the liquid chamber R4 is reduced, and the liquid pressure (regulator pressure) in the liquid chamber R4 is reduced to the liquid chamber R3.
The pressure is regulated approximately equal to the hydraulic pressure inside. Note that if the liquid pressure in the liquid chamber R4 is lower than the sum of the liquid pressure in the liquid chamber R3 and the pressure due to the biasing force of the spring 84, the above-mentioned effect cannot be obtained, and the passage 82a of the piston 82 is filled with pulp. It is held in a closed state by the ball 83a of 83, and the hydraulic pressure from the power hydraulic pressure supply device 90 is directly supplied to the hydraulic pressure circuit P6.

The power hydraulic pressure supply device 90 includes an electric motor 91 that is started and stopped by signals from a microcomputer (not shown) and is driven in the anti-skid operating state, and a hydraulic pump 92 that is driven by the electric motor 91. It is composed of a check valve 93 and the like, and the electric motor 9
When the hydraulic pump 92 is driven by 1, it is possible to generate a power hydraulic pressure that is equal to or higher than the maximum value of the brake hydraulic pressure, which causes a state close to wheel lock.

In addition, other components are omitted from illustration (electrical circuit)
This embodiment is also the same as the first embodiment shown in FIG. Further, the operation obtained in the second embodiment is substantially the same as the operation in the first embodiment described above, and since it is thought to be easily understood, the explanation will be omitted.

In each of the above embodiments, each supply/discharge switching valve 31, 33.
35 and each slow/sudden switching valve 32, 34, 36 are used to control the hydraulic pressure of each wheel cylinder 21, 22, 23, 24. It is also possible to implement the invention by controlling the hydraulic pressure of 21, 22, 23, 24.

〔Effect of the invention〕

In the wheel lock prevention device according to the present invention, in an anti-skid operating state in which the supply/discharge switching valve switches during braking when the brake pedal is depressed, the on-off switching valve disconnects the supply/discharge switching valve from the master cylinder, and By ensuring that a predetermined amount of hydraulic medium remains in the pressure chamber, not only can unnecessary strokes of the brake pedal be prevented, but also the hydraulic pressure in the master cylinder or equivalent pressure in the anti-skid operating state. The hydraulic pressure supplied from the power hydraulic pressure supply source is adjusted to a regulator hydraulic pressure approximately equal to the reference pressure, and the regulator hydraulic pressure from the regulator valve is guided to the supply/discharge switching valve via the check valve. The regulator fluid pressure fluctuates each time it is consumed, but this regulator fluid pressure is not used to assist the operation of the master cylinder, so the regulator fluid pressure is The operation of the master cylinder does not vary due to fluctuations in hydraulic pressure, and it is possible to prevent shock to the brake pedal due to fluctuations in the operation of the master cylinder, thereby improving the operational feeling of the brake pedal.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, FIG. 2 is an enlarged sectional view of the regulator valve shown in FIG. 1, and FIG. 3 is a schematic configuration diagram showing a second embodiment of the present invention. , Figure 4 is the third
FIG. 3 is an enlarged cross-sectional view of the regulator valve shown in the figure. Explanation of symbols 12...Master cylinder, 12A...Reservoir, 2
1 to 24...Wheel cylinder, 31°33.35.
...Supply/exhaust switching valve, 37.38... Open/close switching valve, 50.
...Microcomputer (control value, 60.80
...Regulator valve, 70.90...°Power hydraulic pressure supply device, P1 to P5...Brake hydraulic pressure circuit, Vl,
V2... Che, Riben.

Claims (1)

[Claims] The brake fluid pressure circuit that connects the master cylinder and the wheel cylinder is switched in response to a signal from a control device that detects the locked state of the wheel, and connects the wheel cylinder to the reservoir or the master cylinder. In a wheel lock prevention device that is provided with a supply/discharge switching valve that controls the hydraulic pressure applied to the brake fluid pressure circuit and prevents wheel locking that may occur during vehicle braking, the brake fluid pressure circuit A power hydraulic pressure supply source using a hydraulic medium as a hydraulic medium is attached, and the hydraulic pressure in the master cylinder or a pressure equivalent thereto is set as a reference pressure, and the hydraulic pressure supplied from the power hydraulic pressure supply source is set as the reference pressure. In an anti-skid operating state, a regulator valve is attached to adjust and output substantially equal regulator fluid pressure, and the supply/discharge switching valve switches in a brake fluid pressure circuit connecting the master cylinder and the supply/discharge switching valve. An on-off switching valve that disconnects the supply/discharge switching valve from the master cylinder and connects the supply/discharge switching valve and the master cylinder under normal conditions is installed, and brake fluid pressure between the on-off switching valve and the supply/discharge switching valve is interposed. A wheel lock prevention device characterized in that a regulator hydraulic pressure output from the regulator valve is introduced into a circuit via a check valve.