JPS624666A - Antilock apparatus - Google Patents

Abstract

PURPOSE:To prevent the reduction of brake power by applying brake onto front wheels by a master cylinder hydraulic pressure itself when rear wheels are locked precedently to front wheels in each hydraulic brake system of an X-piping hydraulic brake apparatus. CONSTITUTION:An antilock circuit 19 controls a bypass valve solenoid 17a by adding a rear-wheel lock detecting means 22 onto a module 21 for controlling an actuator 8. The rear-wheel lock detecting means 22 detects that rear wheels 4 are locked precedently to front wheels by a hydraulic brake system including a left front wheel 1 and a rear wheel 4, and is equipped with a wheel-speed calculating circuits 23 and 24 for this purpose. A comparator 27 outputs the H-level when rear wheels 4 are easily locked in comparison with front wheels 1, and an AND-gate 37 outputs the H-level by the output at the H-level of a calculator 28 and a comparator 35, and the bypass valve 17 is set to 17c by the urging of the solenoid 17a, and antilock control is carried out for only the rear wheels 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an anti-lock device for a two-system hydraulic brake system, particularly an X-pipe hydraulic brake system.

(Prior art) The X-piped hydraulic brake system supplies master cylinder hydraulic pressure from both systems from the tandem master turn ring to the left front wheel and right rear wheel cylinder, and the right front wheel and left rear wheel cylinder, respectively. It brakes the wheels.

When an anti-lock device for preventing wheel locking is used in such a hydraulic brake device, for example, Japanese Patent Laid-Open No. 59-206
As shown in No. 248, Japanese Unexamined Patent Publication No. 59-81242,
Preventing each wheel from locking by individually controlling the brake fluid pressure to the wheel cylinder of each wheel would result in an expensive anti-lock device. It is advantageous to control the brake fluid pressure for the right rear wheel in common, and also for the right front wheel and the left rear wheel to prevent wheel lock.

(Problem to be solved by the invention) However, in this case, when braking with only the front and rear wheels on the right or left side riding on a low-friction road, the front and rear wheels on the opposite side are also subjected to anti-lock control unnecessarily. , the braking force of these front and rear wheels is reduced in the same way as the front and rear wheels on a low-friction road, and it is unavoidable that the braking distance becomes longer.

In particular, in a hydraulic brake system where the rear wheels ride on a low-friction road, the braking force is reduced to the front wheels with a large braking force distribution as described above, so the above-mentioned problem of a longer braking distance becomes noticeable.

(Means for Solving the Problem) From this point of view, the present invention provides brakes using master cylinder hydraulic pressure itself without anti-lock control for the front wheels when the rear wheels lock before the front wheels in each hydraulic brake system. Based on the recognition that In an X-piped hydraulic brake system configured to supply water to the left rear wheel cylinder, each hydraulic brake system includes a rear wheel lock detection means for detecting when the rear wheel locks before the front wheel, and a rear wheel lock detection means for detecting when the rear wheel locks before the front wheel. and a bypass valve configured to supply master cylinder hydraulic pressure to the front wheel cylinder by bypassing the anti-lock device actuator in response to a signal from the rear wheel lock detection means in the locked state. It is what it is.

(Operation) Master cylinder hydraulic pressure from both systems from the tandem master cylinder is supplied to the left front wheel and right rear wheel cylinders, and the right front wheel and left rear wheel cylinder, respectively, to brake each wheel. When the wheels tend to lock due to this braking, the anti-lock actuator reduces the brake fluid pressure in the corresponding system to prevent the wheels from locking.

By the way, at this time, if the rear wheels try to lock before the front wheels, the pump-pass valve responds to a signal from the rear wheel lock detection means that detects this, and activates the anti-lock device;
・Bypass the motor and supply master cylinder hydraulic pressure to the front wheel cylinders. (For each hydraulic brake system, if the rear wheels lock before the front wheels, anti-lock control is not applied to the front wheels to prevent the meaningless reduction in braking force.
The aforementioned problem of long braking distance can be avoided.

(Example) - Hereinafter, an example of the present invention will be described in detail based on the drawings.

The drawing shows an X-piped hydraulic brake system for an automobile equipped with the anti-lock device of the present invention, 1.2 is the left and right front wheels, 3.4 is the left and right rear wheels, la to 4a are the wheel cylinders of wheels 1 to 4, respectively, and 5 is the left and right front wheels. A tandem master cylinder, 6 indicates a brake pedal, respectively.

Both master cylinder hydraulic pressures Pm from the master cylinder 5 generated by depressing the brake pedal 6 are as follows.
Pipe line 7, anti-lock device actuator 8, pipe line 9
．． 10.11 to the wheel cylinders la, 4a, and via line 12, anti-lock device actuator 13, line 14.15.16 to the wheel cylinders 2a, 3.
a, and can brake wheels 1, 4 and 2, 3.

A bypass valve 17.18 is inserted into each line 10.15. When the solenoid 17a is de-energized, the valve 17 becomes the port arrangement 17b shown in the figure and opens the pipe line 10, and the solenoid 17a
When the solenoid 18a is energized, the port arrangement 17C is used to supply the master cylinder hydraulic pressure Pm of the conduit 7 to the wheel cylinder 1a, bypassing the actuator 8, and the valve 18 is set to the boat arrangement 18b shown when the solenoid 18a is deenergized. Then, the pipe 15 is opened, and when the solenoid 18a is energized, the port arrangement 18C is set, and the master cylinder hydraulic pressure Pm of the pipe 12 is transferred to the wheel cylinder 2 by bypassing the actuator 13.
It shall be supplied to a.

Actuator 8 turns on and off the solenoid 17a.
The ON/OFF state of the solenoid 18a is controlled by the anti-lock control circuit 20 together with the actuator 13.

The anti-lock control circuit 19 has a module 21 that controls the actuator 8 as a main component, but in the present invention, a rear wheel lock detection means 22 is added thereto to control the bypass valve solenoid 17a. The rear wheel lock detection means 22 serves to detect when the rear wheel 4 is locked before the front wheel 1 in the hydraulic brake system including the left front wheel 1 and the right rear wheel 4, and for this purpose, a wheel speed calculation circuit is used. 23
．． Includes 24.

The circuit 23 includes a rotation sensor 2 that detects the rotation speed of the left front wheel l.
The peripheral speed (wheel speed) of the front wheel 1 is determined from the frequency (rotation speed) and the rotation radius of the front wheel 1.
Vw, and the circuit 24 receives a pulse signal S from a rotation sensor 26 that detects the rotation speed of the right rear wheel 4.

Based on , the wheel speed vII14 of the right rear wheel 4 is calculated in the same manner.

A comparator 27 and a subtractor 28 are provided after the circuits 23 and 24, and the comparator 27 outputs an H level when Vw≧vI114, that is, when the rear wheel 4 has a tendency to lock more than the front wheel 1, , <Vw4, that is, when the front wheel 1 is more likely to lock than the rear wheel 4, the L level is output. Comparator 27
On the other hand, the output of
It is supplied to the gate of analog switch 31 as it is, and on the other hand, it is supplied to the gate of analog switch 31 via inverter 32.
In addition to supplying it to ND gate 33 by one person, A
Supply to ND gate 34 by one person.

AND game) 33. The output of the comparator 35 is supplied to the external power of 34, and this comparator receives the subtraction result of the subtractor 28, that is, V
lol.

and Vw, absolute difference value l Vw, -Vw41 force setting difference value △
Outputs H level for a period of vw or more. The output of the AND gate 33 is: It outputs an H level for a set time in synchronization with the rise of the output, or it is connected to the output of the AND gate 37 via the triggerable timer 36, and the output of the AND gate 34 is connected to the AND gate 37. Connect to the power of others. AND gate 3
7 performs a logical product of the H level output of the AND gate 34 and the L level output of the retriggerable timer 36 to output an H level signal, which energizes the solenoid 17a.

Nafu, analog switches 30 and 31 are turned on when the gate power is at H level, and when they are turned on, Vw or Vw4
is selectively input as the wheel speed Vw to be controlled by the hair lock in the module 21.

The anti-lock control circuit 20 is the anti-lock control circuit 19
The pulse signal S2 from the rotation sensor 38 that detects the rotation speed of the right front wheel 20 and the pulse signal S3 from the rotation sensor 39 that detects the rotation speed of the left rear wheel 3 are manually input to the actuator 13 and the solenoid. A control signal of 18a is output.

Next, the operation of the above-mentioned embodiment will be representatively explained with respect to the hydraulic brake system relating to the front left wheel 1 and the rear right wheel 4.

In a situation where the front wheels 1 and the rear wheels 4 do not lock together or lock at the same time, the respective wheel speeds Vw,
, Vw, there is almost no difference between them, so the absolute difference value 1ΔVwl−ΔVwal between the two calculated by the subtracter 28 is ΔV
Comparatively, the output of 35 is at L level, which is smaller than w. Therefore, the output of AND game) 33.34 is also L level and A
The ND gate 37 is connected to the solenoid 17 by the L level output.
a is deenergized, and the bypass valve 17 is placed in a port configuration 17b.

On the other hand, when Vw≧Vw4, the comparator 27 turns on the analog switch 31 with an H level output, and turns on the analog switch 30 to set the lower wheel speed Vw as the anti-lock control target wheel speed Vw. , <Vw4 comparator 27
turns on the analog switch 30 by L level output,
The analog switch 31 is turned OFF and the lower wheel speed vWl is set as the anti-lock control target wheel speed Vw. Therefore, the lower of Vw, , Vw (select low wheel speed),
In other words, the wheel speed of the wheel that has a tendency to lock becomes the anti-lock control target wheel speed Vw. Based on this, the module 21 detects locking of the wheel 1 or 4 by a well-known method, and if locking occurs, the actuator 8 is notified. The hydraulic pressure to the wheel cylinders la and 4a is reduced to prevent the wheels 1.2 from locking.

Of course, if no lock has occurred, the module 21 will not actuate the actuator 8 and will not activate the wheel cylinders la, 4.
The braking force is increased by increasing the hydraulic pressure to a until it becomes the same as the master cylinder hydraulic pressure Pm.

When the front wheel 1 locks before the rear wheel 4, the calculation result of the subtracter 28 is lVw, and when Vw<l is greater than or equal to △Vw, the comparator 35 supplies an H level signal to the AND gates 33 and 34. . Also, the comparator 27 becomes L due to Vw, >Vw.
Therefore, the analog switch 30 is turned on, and the lower Vw is input to the module 21 as Vw, and an H level signal is output to the AND gate 33, and the AN
An L level signal is input to the D gate 34. This is why A
The ND gate 34 outputs L level, and the AND gate 37
Since the solenoid 17a also outputs the L level, the bypass valve 17 becomes the port arrangement 17b by deenergizing the solenoid 17a. on the other hand,
The module 21 performs the above-mentioned anti-lock control via the actuator 8 based on Vw (Vw, ) and prevents the wheels 1.4 from locking due to the port arrangement 17b of the valve 17. Furthermore, the AND gate 33 outputs an H level, and in synchronization with the rising instant of this output (the instant the front wheels are locked), the retriggerable timer 36 outputs an H level for a set time, during which time the H level output from the AND gate 37 is disabled. prohibit. As a result, even if the AND gate 34 may temporarily output an H level due to the front opening of the rear wheel 4, which will be described later, the bypass valve 17 is set to the current position, assuming that it will return to the front opening of the front wheel 1. The anti-lock control of both the front and rear wheels 1.4 continues.

Conversely, in a situation where the rear wheels 4 lock before the front wheels 1, the calculation result lVw, -Vw, l of the subtractor 28 becomes △
Above Vw, comparator 35 AND K) 33.34
2HL/bell signal is supplied. Also, the comparator 27 is vwl>
The analog switch 31 is turned ON, and the lower Vw is inputted to the module 21 as Vw, and the L level signal is input to the AND gate 33. Also, the H level signal is input to the AND gate 34. do. Therefore, the output of the AND gate 33 is at the L level, and the retriggerable timer 36 continues to output the L level.
Since the D gate 34 outputs an H level, the AND gate 37 outputs an H level, and the bypass valve 17 is placed in the port configuration 17C by energizing the solenoid 17a. On the other hand, the module 21 operates the actuator 8 based on Vw (Vw4).
However, since the valve 17 has a port arrangement 17c, the anti-lock control is performed only for the rear wheels 4. On the other hand, the master cylinder hydraulic pressure Pm of the pipe 7 is supplied to the wheel cylinder 1a of the unlocked front wheel 1, bypassing the actuator 8, and a braking force corresponding to this master cylinder hydraulic pressure is generated in the front wheel 1. . In this way, the braking force of the front wheels 1 with a large braking force distribution is not reduced due to meaningless anti-lock control, and it is possible to prevent the braking distance from increasing.

In addition, regarding the hydraulic brake system related to the front right wheel 2 and the rear left wheel 3, the same effect as described above is obtained by the anti-lock control circuit 20 via the actuator 13 and the bypass valve 18, and the desired purpose is achieved. can do.

(Effects of the Invention) As described above, the anti-lock device of the present invention brakes the front wheels using the master cylinder hydraulic pressure itself when the rear wheels lock before the front wheels in each hydraulic brake system of the X-piped hydraulic brake device. With this structure, the braking force is not reduced due to meaningless anti-lock control even though the front wheels, which have a large braking force distribution, are not locked, and the problem of a long braking distance can be avoided.

[Brief explanation of drawings]

The drawing is a system diagram of an X-piping hydraulic brake system for an automobile equipped with an anti-lock device according to the present invention. 1.2... Left and right front wheels 3.4... Left and right rear wheels 5... Tandem master cylinder 6... Brake pedal 8.13... Anti-lock device actuator 17
, 18... Bypass valve 19, 20... Anti-lock control circuit 21... Module 22... Rear wheel lock detection means

Claims (1)

[Claims] 1. While adjusting the master cylinder hydraulic pressure of both systems from the tandem master cylinder by individual anti-lock device actuators, the left front wheel and right rear wheel cylinders, and the right front wheel and left rear wheel In the X-piped hydraulic brake system configured to supply water to the wheel cylinders, a rear wheel lock detection means detects when the rear wheels are locked before the front wheels in each hydraulic brake system; and a bypass valve configured to supply master cylinder hydraulic pressure to the front wheel cylinder by bypassing the anti-lock device actuator in response to a signal from the rear wheel lock detection means in the locked state. Features an anti-lock device.