JPH0313104B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antilock braking system for a vehicle, particularly a braking force applying system that applies braking force to front wheels and rear wheels, and a braking force applying system that applies braking force to the front wheels when the braking force to the front wheels is too large. A front wheel antilock control device that suppresses power, and a rear wheel antilock control device that is independent of the front wheel antilock control device and suppresses the braking force to the rear wheels when the braking force to the rear wheels is too large. The present invention relates to an anti-lock braking device for four-wheeled vehicles of the same type.

Conventionally, in this type of anti-lock braking device, when the anti-lock control device fails, its control function is completely disabled, so that the anti-lock braking device operates as a normal braking device without an anti-lock control function. It has been proposed to install a safety device to prevent the brakes from stopping, but with the conventional safety device, if either the front wheel or rear wheel antilock control device fails and loses its braking force suppression function, It is not configured to override the other anti-lock control device which is in the normal state, so that the other anti-lock control device remains activated. Therefore, if the driver applies excessive braking force especially when the rear wheel anti-lock control device is in the above-mentioned failure state, the front and rear wheels are more likely to lock, which is already different due to the difference in braking load distribution. In other words, while the front wheels are strongly braked without locking up, the rear wheels tend to lock up early, resulting in a problem in that the steering stability of the vehicle deteriorates.

The present invention can solve the above-mentioned problems associated with a failure of the rear wheel antilock control device, and moreover, if the front wheel antilock control device fails while the braking force is being suppressed, the operation of the control device is immediately disabled. It is an object of the present invention to provide an anti-lock braking device for a four-wheeled vehicle with a simple structure, which can contribute to ensuring braking force and improving steering stability by making it possible to improve steering stability.

In order to achieve this object, the present invention provides a braking force application system that applies braking force to the front wheels and rear wheels, and a front wheel system that suppresses the braking force to the front wheels when the braking force to the front wheels is too large. An antilock control device for a four-wheeled vehicle, comprising an antilock control device and a rear wheel antilock control device independent from the front wheel antilock control device, which suppresses the braking force to the rear wheel when the braking force to the rear wheel is too large. In the braking system, if the front wheel antilock control device fails while the braking force is being suppressed, the front wheel safety device detects the failure and immediately shuts off the operating source of the front wheel antilock control device; The vehicle is characterized by having a rear wheel safety device that detects the failure and immediately shuts off the operating source of the front wheel antilock control device when the rear wheel antilock control device fails to the point where it loses its braking force suppression function. shall be.

According to the present invention, the front wheel antilock control device and the rear wheel antilock control device operate independently of each other, and the front wheel antilock control device for the front wheels, which generally has a relatively large distribution of braking force, suppresses the braking force. In the event of a failure, the front wheel safety device completely disables the front wheel anti-lock control device and secures braking force for the front wheels.
In addition, if the rear wheel anti-lock control device, which generally distributes a relatively small amount of braking force to the rear wheels, breaks down without losing its braking force suppression function, the rear wheel safety device will override the function of the front wheel anti-lock control device. maintains vehicle steering stability by disabling the

The anti-lock braking device includes a braking force transmission device that transmits braking force and applies braking force to the wheels;
When the braking force applied to the wheels by this braking force transmission device is too large, an anti-lock control device acts on the braking force transmission device to suppress the braking force based on preselected control input factors. Equipped with. The anti-lock control device is
Typically, a fluid such as hydraulic oil is used as a control pressure transmission medium, and such fluid is introduced into the control pressure action chamber via a pressure guiding valve and discharged from the control pressure action chamber via a discharge pressure valve. . The pressure impulse valve and the exhaust pressure valve are each operated by an electromagnetic actuator.The electromagnetic actuator for the pressure impulse valve opens the impulse valve when energized and closes the impulse valve when it is not energized. The electromagnetic actuator closes the exhaust pressure valve when energized, and opens the exhaust pressure valve when not energized. Therefore, when both the electromagnetic actuator for the pressure guiding valve and the electromagnetic actuator for the exhaust pressure valve are energized, the amount of fluid in the control pressure action chamber continues to increase, and as a result, the braking force increases regardless of the driver's will. reduced. In addition, the electromagnetic actuator for the pressure guiding valve is not energized,
When only the electromagnetic actuator for the exhaust pressure valve is energized, the fluid in the control pressure action chamber is sealed, and as a result, the braking force is kept constant regardless of the driver's intention. Furthermore, when both the electromagnetic actuator for the pressure guiding valve and the electromagnetic actuator for the exhaust pressure valve are not energized, the fluid in the control pressure action chamber is in a state where it can be freely discharged, and as a result, the braking force is controlled according to the driver's will. Therefore, it can be increased.

Each electromagnetic actuator follows the output signal of an antilock control circuit that generates a control output signal by performing arithmetic processing based on preselected control factors such as vehicle speed, wheel speed increase/decrease, and wheel slip rate. energization is controlled.

The operation of the safety device in the present invention can be implemented in software using a microcomputer, but it can also be implemented using hard logic circuits.

Hereinafter, specific examples of circuits that can be used in implementing the present invention will be described.

In the figure, a wheel speed detector 101 for the right front wheel and a wheel speed detector 102 for the left front wheel each detect the circumferential speed of the corresponding front wheel in the form of a pulse signal, and their output signals are sent to a frequency-voltage converter 103, respectively. , 104. The output signals of the frequency-voltage converters 103 and 104 are respectively sent to the front wheel anti-lock control circuit 105, which performs arithmetic processing and processing based on various control factors as described below. After making the determination, an output signal for antilock control is sent to the front wheel pressure guiding valve actuating device 106 and the front wheel exhaust pressure valve actuating device 107. The front wheel antilock control circuit 105, the front wheel pressure guide valve actuating device 106, and the front wheel exhaust pressure valve actuating device 107 cooperate with each other to constitute the front wheel antilock control device of the present invention.

Next, the front wheel antilock control device will be explained in more detail. The front-stage signal processing section 110 of the front wheel anti-lock control circuit 105 performs preselected types of control such as vehicle speed, wheel increase/decrease speed, wheel slip rate, etc. based on wheel speed signals obtained from the wheel speeds of the left and right front wheels. After the control factors are calculated and a judgment is made according to preset judgment criteria based on these control factors, the output section 111 outputs a pressure valve intermittent operation signal, and the output section 112 outputs a pressure valve intermittent operation signal. A pressure guiding valve continuous activation signal is sent out. At this time, the pressure impulse valve intermittent operation signal sent from the output section 111 is a signal for controlling the pressure impulse valve to gradually increase the control pressure by repeatedly opening and closing the pressure impulse valve intermittently, and
The continuous pressure valve operation signal sent from the output part 112 is sent to the oscillator 113 only when the pressure valve continuous operation signal is not sent from the output part 112, whereas the pressure valve continuous operation signal sent from the output part 112 is controlled by continuously opening the pressure valve. This is a signal for controlling the pressure to increase instantaneously, and is sent to the OR circuit 114 together with the output signal of the oscillator 113. And this OR circuit 1
The output signal of 14 is sent to an AND circuit 115.

In addition, the output unit 116 outputs a front wheel side vehicle speed for controlling the control pressure so that the control pressure can be increased only when the vehicle body speed estimated based on the circumferential speed of the left and right front wheels is equal to or higher than a preset speed. A response signal is sent out, and this front wheel vehicle speed response signal is sent to a pair of AND circuits 115 and 125.

Further, the output section 121 outputs an intermittent operation signal for the exhaust pressure valve, and the output section 122 outputs a continuous operation signal for the exhaust pressure valve. At this time, the exhaust pressure valve intermittent operation signal sent from the output section 121 is
This is a signal for controlling the control pressure to gradually decrease by repeatedly opening and closing the exhaust pressure valve intermittently, and only when the exhaust pressure valve continuous operation signal is not sent from the output section 122, the oscillator 12
On the other hand, the exhaust pressure valve continuous operation signal sent from the output section 122 is a signal for controlling the exhaust pressure valve to continuously close and prevent the control pressure from decreasing. It is sent to the OR circuit 124 together with the output signal. The output signal of this OR circuit 124 is then sent to an AND circuit 125.

The pair of AND circuits 115 and 125 are connected to a rear wheel antilock control circuit 20, which will be described later.
Control pressure is controlled so that the control pressure can be increased only when the signal sent from the output section 216 of No. 5, that is, the vehicle speed estimated based on the circumferential speed of the left and right rear wheels, is equal to or higher than a preset speed. The rear wheel side vehicle speed response signal for this purpose is also received as an input signal.

After the output signal of the AND circuit 115 is inverted, it is sent to the base of the power transistor 133 of the front wheel pressure control valve operating device 106 via the output section 131 of the front wheel antilock control circuit 105. The emitter side of the power transistor 133 is connected to the battery power source 132, and the collector side is connected to the front wheel pressure guiding valve electromagnetic actuator 134.

After the output signal of the AND circuit 125 is inverted, it is sent to the base of the power transistor of the front wheel exhaust valve operating device 107 via the output section 141 of the front wheel antilock control circuit 105. The circuit configuration of this front wheel exhaust pressure valve actuating device 107 is basically the same as the circuit configuration of the front wheel pressure guiding valve actuating device 106, so illustration thereof is omitted. However, the emitter side of the power transistor of the front wheel exhaust pressure valve actuating device 107 is connected to the battery power supply 132, while the collector side is connected to the front wheel exhaust pressure valve electromagnetic actuator.

The wheel speed detector 201 for the right rear wheel and the wheel speed detector 202 for the left rear wheel each detect the circumferential speed of the corresponding rear wheel in the form of a pulse signal, and send these output signals to the frequency-voltage converter 203, respectively. ,2
Send to 04. Each frequency-voltage converter 203, 20
The output signals of 4 are respectively sent to the rear wheel antilock control circuit 205, which, like the front wheel antilock control circuit 105, performs arithmetic processing and judgment based on various control factors. After performing this, an output signal for anti-lock control is sent to the rear wheel pressure guiding valve actuating device 206 and the rear wheel exhaust pressure valve actuating device 207. The rear wheel anti-lock control circuit 205, the rear wheel pressure guiding valve actuating device 206, and the rear wheel exhaust pressure valve actuating device 207,
They cooperate with each other to constitute the rear wheel antilock control device of the present invention.

Next, the rear wheel antilock control system will be explained in more detail. Anti-lock control circuit 2 for rear wheels
In the pre-stage signal processing unit 210 of 05, preselected types of control factors such as vehicle speed, wheel speed increase/decrease, and wheel slip rate are calculated based on the wheel speed signals obtained from the wheel speeds of the left and right rear wheels. Based on these control factors, judgments are made according to preset criteria, and then
The output section 211 outputs a pressure guiding valve intermittent operation signal, and the output section 212 outputs a pressure guiding valve continuous operation signal. At this time, the pressure impulse valve intermittent operation signal sent from the output section 211 is a signal for controlling the pressure impulse valve to gradually increase the control pressure by repeatedly opening and closing the pressure impulse valve intermittently. Whereas the continuous actuation signal is sent to the oscillator 213 only when the continuous actuation signal is not being sent out, the pressure valve continuous actuation signal sent from the output section 212 continuously opens the pressure valve and instantly increases the control pressure. This signal is sent to the OR circuit 214 together with the output signal of the oscillator 213. The output signal of this OR circuit 214 is then sent to an AND circuit 215.

Further, the output section 221 outputs an intermittent operation signal for the exhaust pressure valve, and the output section 222 outputs a continuous operation signal for the exhaust pressure valve. At this time, the exhaust pressure valve intermittent operation signal sent from the output section 221 is
This is a signal for controlling the control pressure to gradually decrease by repeatedly opening and closing the exhaust pressure valve intermittently, and only when the exhaust pressure valve continuous operation signal is not sent from the output section 222, the oscillator 22
On the other hand, the exhaust pressure valve continuous operation signal sent from the output section 222 is a signal for controlling the exhaust pressure valve to continuously close and prevent the control pressure from decreasing. It is sent to the OR circuit 224 together with the output signal. The output signal of this OR circuit 224 is then sent to an AND circuit 225.

Furthermore, the output unit 216 outputs rear wheel output for controlling the control pressure such that the control pressure can be increased only when the vehicle body speed estimated based on the peripheral speed of the left and right rear wheels is equal to or higher than a preset speed. A side vehicle speed response signal is sent out, and this rear wheel side vehicle speed response signal is sent to a pair of AND circuits 115, 125 of the front wheel antilock control circuit 105 and a pair of AND circuits 215, 225 of the rear wheel antilock control circuit 205.
are sent to each.

After the output signal of the AND circuit 215 is inverted, it is sent to the base of the power transistor 233 of the rear wheel pressure guiding valve operating device 206 via the output section 231 of the rear wheel antilock control circuit 205. The emitter side of the power transistor 233 is connected to the battery power source 232, and the collector side is connected to the rear wheel pressure guiding valve electromagnetic actuator 234.

Further, the output signal of the AND circuit 225 is inverted and then passed through the output section 235 of the rear wheel antilock control circuit 205 to the rear wheel exhaust pressure valve operating device 207.
is sent to the base of the power transistor 237.
The emitter side of the power transistor 237 is connected to a battery power source 236, and the collector side is connected to a rear wheel exhaust valve electromagnetic actuator 238.

Next, the front wheel safety device will be explained. This front wheel safety device is a front wheel pressure valve actuation device 106.
a front wheel pressure guiding valve side failure detection device 108 that operates using the collector side output signal of the power transistor 133 as an input signal, and a front wheel exhaust pressure valve actuating device 107.
A front wheel exhaust pressure valve side failure detection device 109 which operates using the collector side output signal of the power transistor as an input signal, a front wheel pressure guide valve side failure detection device 108 and a front wheel exhaust pressure valve side failure detection device 109.
An OR circuit 301 that receives an output signal from the OR circuit 301 operates in response to the output signal of this OR circuit 301 to abnormally suppress the braking force in either the front wheel pressure guide valve actuating device 106 or the front wheel exhaust pressure valve actuating device 107. When it is determined that the front wheel anti-lock control device has failed due to continued
7, and a safety relay 302 that shuts off the battery power supply 132 that is the operating source of 7.

The circuit configuration of the front wheel exhaust pressure valve side failure detection device 109 is basically the same as the circuit configuration of the front wheel pressure guide valve side failure detection device 108, so illustration thereof is omitted. Therefore, the front wheel pressure guiding valve side failure detection device 108 will be described in more detail below.

When the front wheel pressure guiding valve electromagnetic actuator 134 is energized, the one-shot circuit 135 is activated at the same time, and its output signal is inverted and sent to the AND circuit 136. The output signal of the power transistor 133 is also directly sent to an AND circuit 136, and the operation of the one shot circuit 135 causes the AND circuit 136 to operate the front wheel pressure induction valve electromagnetic actuator 134.
The power transistor 133 does not generate an output signal until a preset time has elapsed after the power transistor 133 is energized, and if the power transistor 133 continues to generate an output signal even after the preset time has elapsed, the front wheel antilock control device takes control. OR circuit 137 and OR circuit 3 are determined to have failed with the power still suppressed.
A signal is sent to the safety relay 302 through 01 to cut off the battery power supply 132.

The output signal of the power transistor 133 is further sent in an inverted state to a retrigger type one-shot circuit 138 and also directly to an AND circuit 139. One shot circuit 13
8 always generates an output signal while the pulse interval of the output signal of the power transistor 133 is equal to or less than a preset interval, and as a result, the AND circuit 139 generates the output signal as the output signal of the power transistor 133 is interrupted. and sends its output signal to the counter circuit 140. Counter circuit 140
counts the number of pulses of the input signal, and when the number of pulses reaches a preset value, it is determined that the front wheel antilock control device has failed while suppressing the braking force, and the OR circuit 137 and the OR circuit 137 and A signal is sent to the safety relay 302 through the circuit 301 to cut off the battery power supply 132.

The output signal of the one-shot circuit 138 is inverted and sent to the counter circuit 140, so that
The counter circuit 140 is placed in a reset state, and if the pulse interval of the output signal of the power transistor 133 exceeds the set interval before the number of pulses counted by the counter circuit 140 reaches the set value, one shot is activated. The output signal of circuit 138 is interrupted, and as a result, counter circuit 140 is placed in a reset state so that it does not generate an output signal and antilock control continues.

Next, the rear wheel safety device will be explained. This rear wheel safety device includes a rear wheel pressure guiding valve side failure detection device 208 that detects abnormal operation of a rear wheel pressure guiding valve actuating device 206, and a rear wheel pressure valve side failure detection device 208 that detects abnormal operation of a rear wheel exhaust pressure valve actuating device 207. Exhaust pressure valve side failure detection device 209
It operates according to the output signal of the OR circuit 301 which receives the output signals of the rear wheel pressure guiding valve side failure detection device 208 and the rear wheel exhaust pressure valve side failure detection device 209, and operates the rear wheel pressure guiding valve actuating device 206 or When it is determined that the rear wheel anti-lock control device has failed in a state where either one of the rear wheel exhaust pressure valve actuating devices 207 has lost the braking force suppression function, the front wheel pressure valve actuating device 106 and the front wheel exhaust valve actuating device 106 are activated. Battery power supply 13 which is the operation source of the pressure valve actuation device 107
2, and a safety relay 302 that shuts off the power. However, the OR circuit 301 and the safety relay 302 are shared with the front wheel safety device.

The circuit configuration of the rear wheel exhaust pressure valve side failure detection device 209 is basically the same as the circuit configuration of the rear wheel pressure guide valve side failure detection device 208, so illustration thereof is omitted. Therefore, the rear wheel pressure guiding valve side failure detection device 208 will be described in more detail below.

The output signal of the AND circuit 239, which uses the base voltage and collector voltage of the power transistor 233 as input signals, is sent to the delay circuit 240. If this continues, the delay circuit 240 indicates that the power transistor 233 is short-circuited or that the rear wheel pressure guiding valve solenoid actuator 2 is short-circuited.
34 is determined to be disconnected, and sends an output signal to the one-shot circuit 241. When the one-shot circuit 241 receives a signal from the delay circuit 240, it generates an output signal for a preset time.

When the one-shot circuit 241 generates an output signal, the output signal of the oscillator 243 is output to the AND circuit 244.
to the base of transistor 245 through
Transistor 245 is intermittently turned on. If the power transistor 233 is short-circuited at this time, the collector voltage of the power transistor 233 is inverted and sent to the AND circuit 242, so the AND circuit 242 does not generate an output signal.
However, if the rear wheel pressure guiding valve electromagnetic actuator 234 is disconnected, by making the size of the resistance R ₁ sufficiently smaller than the size of the resistance R ₂ ,
When the output signal of the oscillator 243 is at a high level, the collector potential of the power transistor 233 is at a low level. It is determined that the wheel anti-lock control device has lost its braking force suppression function and has failed, and the output signal of the one-shot circuit 241 is sent through the OR circuit 301 to the safety maintenance relay 302.
source of the anti-lock control system for the front wheels,
For example, the battery power supply 132 is shut off.

As described above, according to the present invention, there is provided a braking force applying system that applies braking force to the front wheels and rear wheels, and a front wheel antilock control that suppresses the braking force to the front wheels when the braking force to the front wheels is too large. and a rear wheel antilock control device independent from the front wheel antilock control device, which suppresses the braking force to the rear wheel when the braking force to the rear wheel is too large. a front wheel safety device that detects the failure and immediately shuts off the operating source of the front wheel antilock control device when the front wheel antilock control device fails while the braking force is being suppressed; When the anti-lock control device for the front wheels malfunctions to the point where it loses its braking force suppression function, the rear wheel safety device detects the failure and immediately shuts off the operating source of the anti-lock control device for the front wheels. If the anti-lock control system malfunctions to the point where it loses its braking force suppression function, the operation of the anti-lock control system for the front wheels can be immediately disabled and the braking state can be switched to normal. By minimizing the difference as much as possible, it is possible to avoid early locking of only the rear wheels and ensure the steering stability of the vehicle. On the other hand, even if the front wheel antilock control device fails while the braking force is being suppressed, the operation of the front wheel antilock control device can be immediately disabled and the braking condition can be switched to normal. It is possible to always secure the necessary braking force for the large front wheels.

[Brief explanation of the drawing]

The figure is a circuit diagram of an anti-lock braking system with safety devices for front and rear wheels according to an embodiment of the present invention. 105... Front wheel antilock control circuit constituting the front wheel antilock control device, 106... Front wheel pressure guiding valve actuating device, 107... Front wheel exhaust pressure valve actuating device, 108... Front wheel constituting the front wheel safety device. 109...Front wheel exhaust pressure valve side detection device, 132...Battery power source forming the operating source of the front wheel antilock control device, 205...Rear wheel forming antilock control device Wheel antilock control circuit, 206...
Rear wheel pressure guiding valve operating device, 207... Rear wheel exhaust pressure valve operating device, 208... Rear wheel pressure guiding valve failure detection device constituting the rear wheel safety device, 209... Rear wheel exhaust valve actuating device, Pressure valve side detection device, 301...OR circuit shared by the front wheel safety device and the rear wheel safety device, 302...safety maintenance relay.

Claims (1)

[Claims] 1. A braking force application system that applies braking force to the front wheels and rear wheels, and front wheel antilock control devices 105 to 107 that suppress the braking force to the front wheels when the braking force to the front wheels is too large;
For a four-wheel vehicle, the vehicle is equipped with a rear wheel antilock control device 205 to 207 independent of the front wheel antilock control devices 105 to 107, which suppresses the braking force to the rear wheel when the braking force to the rear wheel is too large. In the anti-lock braking device, the front wheel anti-lock control device 105-1
07 fails while the braking force is being suppressed, front wheel safety devices 108, 109, and 30 detect the failure and immediately cut off the operating source of the front wheel antilock control devices 105 to 107.
1,302, when the rear wheel antilock control devices 205 to 207 fail to the point where they lose their braking force suppression function, the failure is detected and the operating source 132 of the front wheel antilock control devices 105 to 107 is immediately turned on. Rear wheel safety device 20 to shut off
8, 209, 301, 302.