JPS6338067A - Control of pressurization of brake hydraulic pressure in antiskid control - Google Patents

Abstract

PURPOSE:To realize the proper hydraulic control state and improve durability of a solenoid valve by pressurizing the brake hydraulic pressure which is decompressed by the sharp reduction of the wheel speed in brake application at a low speed through the repetition of the pressurization and the holding of the transmission of the hydraulic pressure by controlling the opening/closing of a solenoid valve. CONSTITUTION:In the ordinary brake operation state, a hold valve 2 and a reducing valve 3 are in the opened and closed states, respectively, and when the wheel decelera tion speed exceeds a certain set value, the hold valve 2 and the reducing valve 3 are switched to the closed and opened states by a control circuit 9. Therefore, the reduction of the brake hydraulic pressure and the pumping-up to an accumulator 12 are carried out, and then a gate valve 1 closes a main passage 4. When the wheel deceleration speed lowers a certain value, outputting a signal S2 is suspended, and the brake hydraulic pressure is maintained in the held state. When the wheel speed reaches the acceleration speed state, outputting a signal S1 is suspended, and the pressurized oil supplied from the accumulator 12 is transmitted to a wheel cylinder W/C by opening the hold valve 2.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an anti-skid control method for preferably controlling wheel rotation behavior during vehicle braking, and more specifically, the present invention relates to an anti-skid control method for preferably controlling wheel rotation behavior during vehicle braking. The present invention relates to a method for preferably pressurizing.

[Background of the invention]

As is well known, anti-skid control reduces the brake hydraulic pressure in order to avoid wheel braking problems that may lead to wheel locking, and then increases the pressure in order to prevent unnecessary extension of the braking distance. Various proposals have been made, including, for example, a system in which the pressurization mode of the brake oil pressure can be selected from among several different pressurization rates. In addition, as a specific device for changing the pressurization rate, a solenoid valve device that can open and close at a relatively high frequency is installed in the brake hydraulic pressure system, and a multivibrator is installed in the drive control system of this solenoid valve device. There is also a known system (British Patent No. 1305430) in which a pulse train generator is provided, and the timing for driving the solenoid valve device is determined based on the wheel acceleration signal by the pulse train signal output from the multivibrator. It is being

By the way, 12 as mentioned above! In a system in which a mother valve device is installed in the brake hydraulic anti-skid pressure system and is opened and closed by introducing a predetermined flat pulse train signal, the valve seat and valve body collide many times within a minute time. Due to repeated engagement and separation, the durability of the expensive @ solenoid valve is compromised, and the solenoid valve is only switched on and off at relatively low frequencies or only at the start and end of pressurization, holding, and depressurization. In the method of doing
Because the timing of opening and closing the solenoid valve results in a rough slope determination, the wheel speed changes moment by moment, and the brake hydraulic pressure is controlled as ideally as possible based on, for example, deceleration information obtained from the wheels. There was a problem that it was not possible to provide enough characteristics.

[Purpose of the invention]

The present invention has been made from this point of view, and its purpose is to conveniently drive and control the solenoid valve provided in the anti-skid pressure system of the brake hydraulic pressure, thereby realizing a suitable hydraulic control state and controlling the electromagnetic valve. It is an object of the present invention to provide a pressurization control method that improves the durability of a valve and also enables spring control.

[Summary of the invention]

Therefore, the method of pressurizing the brake oil pressure in anti-skid control according to the present invention, which has been made for this purpose, controls the brake oil pressure reduced due to a sudden drop in wheel speed during vehicle braking by controlling the opening and closing of a solenoid valve. A pressurization control method that repeatedly maintains and pressurizes hydraulic pressure transmission from a hydraulic source to a brake device, and pressurizes brake hydraulic pressure at a slow speed,
The opening/closing of the solenoid valve is driven at a power frequency higher than the mechanical response frequency of the solenoid valve, and the opening/closing ratio during the anti-skid cycle can be varied as necessary. Nichiru.

It goes without saying that the slow pressurization control of the brake oil pressure in the present invention may be combined with a method of rapidly pressurizing the brake oil pressure by keeping the solenoid valve fully open as necessary.

Further, in the present invention, the frequency higher than the mechanical response frequency of the solenoid valve is usually 100 Hz or higher, preferably 250 to 250 Hz.
A frequency of 1000 Hz is preferably chosen. By driving the solenoid valve to open and close at such a high frequency, the 'tJL solenoid valve is maintained substantially stationary in a position where the valve body is separated from the valve seat, and the 'tJL solenoid valve is maintained substantially stationary at a position where the valve body is separated from the valve seat. The magnetic valve acts as a throttle valve according to the distance between the valve body and the valve seat, and can obtain a slow increase in brake oil pressure, as well as improve durability by repeatedly facing the valve seat and valve body. The difficulty of sexual decline is also realized.

Furthermore, the opening/closing of a solenoid valve at high frequency, the throttle valve-like action by one pulse, can be changed by allowing the ratio of between/close, and -1 function is the ratio K (=opening). /Close) greater than 1 will give a relatively rapid increase in brake oil pressure, and if it is less than 1, a relatively slow increase in brake oil pressure will be given.
(-1 to 0.06. Preferably K -0.5 to 0.06
It is preferable to vary it within the range of .

[Embodiments of the invention]

The present invention will be explained in more detail below based on the drawings.

The first shows an example of the general configuration of an anti-skid control device to which the method of the present invention is applied. In the figure, 1 is a date pulp, 2 is a solenoid valve device for both pressurization and holding (hereinafter simply referred to as a hold pulp), and 3 4 is a solenoid valve device for depressurization (hereinafter simply referred to as a depressurizing pulp), and 4 is a wheel brake device W/C (both are not shown) from a mask cylinder hVc (not shown) through a dirt pulp 1 and a pressurized pulp 2. This is the main path for transmitting brake hydraulic pressure connected to the brake valve (as shown).

In the above, date pulp 1 is moved by differential pressure ♂ stone 5
When the cylinder 6.7 has a built-in cylinder and moves to the left in the diagram due to differential pressure? The valve 8 part of this date is closed. When the r-t valve 8 is closed, the mask cylinder 4J! 11 and the Gutparg downstream (foil cylinder 0) are pressure-blocked.

The hold pulp 2 is normally open and is switched to a closed state by a hydraulic pressure holding signal St from the control circuit 9.
The main path is shut off (hydraulic pressure maintained).

The reduced pressure pulp 3 is normally closed and is switched to an open state by the reduced pressure signal St from the control circuit. Pump up the pressure oil to y-topulg 1 and hold pulp 20 to return this pumped pressure oil to pi-f.
is connected to the bus path 13. In addition, 14 is a check valve,
13 is a relief valve; 15 is a wheel speed detector (speed sensor), which is attached to the wheel 16 and inputs detected information to the control circuit 9;

FIG. 2 shows the state of the anti-skid control performed by the above anti-skid control device using the signals S1 and S.
2, and the brake oil pressure P (internal pressure in the wheel cylinder). Using the wheel speed v7 as the information source, the control circuit 9 turns on and off the signals S1 + S2 as follows. Control.

During normal braking, the hold pulp 2 and vacuum pulp shown in FIG. 1 are normally open and normally closed, respectively, and the mask cylinder M/C and the foil cylinder are maintained in a communicating state. Therefore, brake hydraulic pressure is generated and transmitted in accordance with the road to the brake pedal (not shown), and a brake force is generated (until time t1).

In the anti-skid control pressure reduction control circuit, for example, when the wheel deceleration exceeds a predetermined constant value (-g=), a signal S! S! is simultaneously output, the hold valve 2 is closed and the pressure reducing valve 30 is opened, thereby reducing the υ brake oil pressure and pumping it up to the pressure accumulator 12, and in conjunction with this, the y-topulp closes the main path 4. When the wheel deceleration falls below the constant value (-gl) due to this brake oil pressure reduction, the output of the signal S2 is stopped and the brake oil pressure is maintained (at the time tilt, ~ts
).

During pressurization for anti-skid control, for example, when the wheel speed becomes accelerated, the output of the signal S0 is stopped, and the hold valve 2 is opened, so that the pressure oil from the pressure accumulator 12 is transmitted to the wheel cylinder of the brake device.
Brake oil pressure is increased. The brake hydraulic pressure at this time is increased rapidly by fully opening the hold valve 2.
It can be divided into slow pressurization in an open state like a throttle valve at a frequency exceeding the response frequency of the hold valve 2, and gentle pressurization in an open state like a throttle valve.
By changing the opening/closing ratio of the excitation drive of the hold valve, different gentle pressurization gradients as shown in FIG. 2A and B can be obtained.

To determine such a gentle pressurization gradient, various methods can be used, such as detecting wheel deceleration every few m3 to several tens of mm, and reading out the opening/closing ratio corresponding to the detected deceleration from memory. It can be implemented by using and applying it.

Now’d! Considering the structure of a magnetic valve as shown in Figure 3, the balance when opening and closing the valve is as follows.

In addition, the transient change in electromagnetic attraction force is explained in Figure 4. If hydraulic pressure + ta suction car SP force = F, the acceleration of the armature is α = - < m: mass of the armature).
When tt < t < tz, I'j1'r! If one magnetic valve is driven, the square becomes half-open, or an island.

Also, the open/close ratio can be changed as shown in the table below depending on the magnitude of the wheel acceleration (2) obtained by differentiating the wheel speed.

α,>V K<0.1 α2≧VW≧αH0,1(K (1 VW>α2 Open)According to the above configuration, the increase in brake hydraulic pressure in anti-skid?til control can be controlled by changing the behavior of the actual wheel speed. In addition, since the information for pressurization control can be obtained in a simplified form, various effects such as easier circuit design can be obtained. .

[Background of the invention]

According to the present invention, the brake oil pressure can be pressurized smoothly during anti-skid control, and repeated collisions between the valve body and the valve seat of the solenoid valve are prevented, which improves durability. This has the effect of providing a significant improvement.

[Brief explanation of drawings]

The drawings are for explaining the present invention; the first section is a diagram showing an overview of the configuration of an anti-skid control device to which the method of the present invention is applied, and the second section is a diagram showing an example of the configuration of an anti-skid control device to which the method of the present invention is applied;
Figure 3 is a diagram explaining the change characteristics of the output of 82 and brake oil pressure, Figure 3 is a diagram explaining the movement of the armature of the solenoid valve,
FIG. 4 is a diagram showing a transient state of the ta attraction force acting on the armature immediately after the start of energization. 1: f-) No. 2: Hold pulp 3: Decompression pulp 8: Date section 9: Control circuit 15 Speed sensor
Small Hiragishi 1) Masayuki □. -m-Yuzu Shinbu Koji □-Ko--” 〉Electromagnetic book attraction

Claims (1)

[Claims] The brake hydraulic pressure, which has been reduced due to a sudden drop in wheel speed during vehicle braking, is controlled by opening and closing of a solenoid valve to maintain and pressurize the hydraulic pressure from the hydraulic source to the brake system, thereby increasing the brake hydraulic pressure at a slow speed. A pressurization control method for skid control, in which the opening and closing of the solenoid valve is driven at a power frequency higher than the mechanical response frequency of the solenoid valve, and the opening/closing ratio during the anti-skid cycle is variable. A brake hydraulic pressure control method in anti-skid control, characterized in that: