JPH08258693A - Brake device of vehicle - Google Patents

Abstract

PURPOSE: To suppress a rise of the temp. of main brake device and reduce wear of a brake pad or lining by furnishing a main brake device and an aux. brake device, actuating the aux. brake device in the case of small braking force, and actuating at least the main brake device in the case of large braking force. CONSTITUTION: When the temp. of a main brake device 14 has risen, the driver is given an alarm for generation of a condition in which the main brake device is likely to make fading. The brake pedal stepping-on amount is sensed by a pedal sensor 1 while the braking air pressure is sensed by an air pressure sensor 4. The target braking amount is calculated from the brake pedal stepping-on amount, and an aux. brake device is actuated when the target braking force can be obtained only from the aux. brake device 8. When such can not be attained with the aux. 8 solely, the target braking air pressure is calculated. In case the target is higher than the internal pressure of an air tank, the target braking air pressure is made equal to the tank air pressure, and a solenoid valve 7 is operated so that a braking force is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle braking device, and more particularly to a technique for integrally controlling a main braking device and an auxiliary braking device.

[0002]

Brake devices installed in commercial vehicles such as buses and trucks include, for example, air-over-hydraulic or full-air type main brake devices that use air pressure to brake the vehicle, and retarders and exhaust brakes. Auxiliary brake devices such as are known.

Further, in recent years, due to advances in electronic control technology, a brake CBW (Contro) capable of independently and freely controlling the braking force of four wheels as a vehicle braking force distribution control device.
It is also known to perform braking force distribution control of a wheel load proportional type using an l-By-Wire system ("HOND").
A R & D Technical Review ”Vo
l. 5 (1993)).

[0004]

By the way, in a vehicle in which a conventional auxiliary brake device and an air-type main brake device are used together, a driver operates a brake pedal to embody the driver's intention to brake the vehicle. Only the main brake device operates regardless of the amount of pedal operation.
In this case, only the main brake device causes an increase in brake temperature and wear of the brake pad or lining.

A brake C for distributing the braking force of the vehicle
In the BW system, there is a problem that the brake temperature of the main brake device of the wheel having a large distribution of the braking force is more likely to rise than the main brake device of the other wheels, and the brake pad or the lining is worn out severely. In view of the above problems, it is an object of the present invention to reduce the increase in the brake temperature of the main brake device and the wear of the brake pads or the lining.

[0006]

Therefore, the invention according to claim 1 is a brake pedal operation amount detecting means for detecting an operation amount of a brake pedal in a vehicle in which an auxiliary brake device and an air-type main brake device are used together. And an air tank air pressure detection means for detecting the air pressure of the air tank in the operating air circuit of the main brake device, a brake air pressure detection means for detecting the brake air pressure of the main brake device, and a brake temperature detection for detecting the brake temperature of the main brake device. Means, a brake control means for controlling the main brake device of the vehicle on the basis of the detected brake pedal operation amount, air tank air pressure, brake air pressure and brake temperature, and an auxiliary brake device if the braking force is small, If the braking force is large, use the less And also the brake switching control means for actuating the main brake device, and comprise configured braking device of the vehicle.

According to a second aspect of the invention, the main braking device is a braking device for a vehicle according to the first aspect, in which a braking force is distributed.

[0008]

In the invention described in claim 1, when the braking force is small, for example, when the operation amount of the brake pedal is small,
When the braking force of the auxiliary braking device is large, for example, when the operation amount of the brake pedal is large, at least the main braking device of the auxiliary braking device and the main braking device is operated to reduce the load on the main braking device,
It is possible to suppress the fade due to the temperature rise of the main brake device and reduce the wear of the pad or the lining.

According to the second aspect of the invention, when the braking force distributed to each wheel of the system for distributing the braking force of the vehicle is small, the auxiliary braking device is used. When the distributed braking force is large, the auxiliary braking device is used. By operating at least the main braking device of the auxiliary braking device and the main braking device, the load on the main braking device of the wheel having a large distribution of the braking force is reduced, and the fade due to the temperature rise of the main braking device is suppressed, and the pad is also provided. Or the wear of the lining can be reduced.

Further, since the auxiliary brake device is used more frequently, the consumption of air used in the main brake device can be reduced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an overall system configuration diagram when the present invention is used in a vehicle using an air-over-hydraulic main brake device. A main brake device 14 that applies hydraulic pressure to each wheel of the vehicle to perform braking
(14a to 14d) are provided, and these main brake devices 14 are each provided with hydraulic piping through an air booster 1 of an operating air circuit.
3 (13a to 13d). The air booster 13 supplies a hydraulic pressure proportional to the input air pressure to the main brake device 14, and is connected to the air tank 11 (11a, 11b) through a solenoid valve 7 (7a-7d). When the control device 2 described later outputs a signal corresponding to the braking force, the solenoid valve 7 supplies the air booster 13 with an air pressure proportional to the signal.

Further, the air tank 11 (11a, 11b)
A compressor 9 for filling the air tank with air is connected to the air tank 11b. The air tank 11b is connected to the electromagnetic valve 7 (7a to 7d) and the air booster 1 via the electromagnetic valve 12 for emergency stop.
It is connected to the piping between 3 (13a-13d). As the detection means necessary for control, a pedal sensor 1 for detecting the operation amount of the brake pedal, an air pressure sensor 3 for detecting the air pressure of the air tank, an air pressure sensor 4 for detecting the air pressure output from the solenoid valve 7, and a vehicle A temperature sensor 5 for detecting the temperature of the main brake device provided for each wheel is provided at the location shown in FIG.

FIG. 2 is a control block diagram of the system according to the first aspect of the present invention. The output of the pedal sensor 1 as the brake pedal operation amount detecting means is
Target brake air pressure calculation means 16 via input means 15
The output of the air pressure sensor 4 as a brake air pressure detecting means is input to the brake air pressure checking means 18 via the input means 15 and the output of the temperature sensor 5 as a brake temperature detecting means is input to the auxiliary brake drive signal generating means 17. To the brake temperature checking means 19 via the means 15,
The output of the air pressure sensor 3 as the air tank air pressure detection means is input to the air tank air pressure check means 20 via the input means 15, respectively. The output of the target brake air pressure calculation means 16 is branched and input to the brake air pressure check means 18, and the output of the air tank air pressure check means 20 is branched and input to the brake air pressure check means 18.

The outputs of the target brake air pressure calculating means 16 and the brake air pressure checking means 18 are output to the control signal switching means 6 via the output means 21, and the output of the control signal switching means 6 is output to the solenoid valve 7. The output of the auxiliary brake drive signal generating means 17 is sent to the auxiliary brake means 8 via the output means 21 and to the brake air pressure checking means 18.
Output of the emergency stop solenoid valve 12 via the output means 21.
In addition, the brake air pressure check means 18, the brake temperature check means 19, and the air tank air pressure check means 2
The output of 0 is transmitted to the alarm display means 10 for notifying the driver of an abnormality of the brake system system such as a decrease in the air pressure of the air tank to the air tank air pressure check means 20 via the output means 21.
Are output to the compressor 9 via the output means 21, respectively.

Next, the control contents of the embodiment according to the first aspect of the invention will be described. The flowcharts shown in FIGS. 4 and 5 show the control contents of the main braking device and the auxiliary braking device by the control device 2. Step 1 (in the figure,
It is abbreviated as S1. In the following (same), predetermined initialization is performed when the control device is started by the ignition key.

In step 2, the air pressure sensor 3 detects the air tank air pressure and the temperature sensor 5 detects the main brake temperature. In step 3, it is determined whether or not the air tank air pressure is within the specified range, and if it is not within the specified range, in step 4, it is determined whether or not the air tank air pressure has decreased to an extent that hinders traveling, and is decreased. If it is necessary to issue an alarm at this time, in step 5, an air tank air pressure shortage alarm is displayed on the alarm display device 10, and the process proceeds to step 7. If the air tank air pressure does not hinder the running, the air tank air pressure shortage alarm display of the alarm display device 10 is canceled in step 6. In step 7, since it is determined in step 3 that the air tank air pressure is not within the specified range, the air tank 11
After starting the compressor 9 to fill (11a, 11b) with air, the process proceeds to step 9. On the other hand, when it is determined in step 3 that the air tank air pressure is within the specified range, in step 8, the compressor 9
Stop and proceed to step 9. That is, step 3
At step 8, control and alarm display for maintaining the air pressure in the air tank for braking the vehicle at a predetermined pressure are performed.

In step 9, it is judged whether or not the brake temperature detected in step 2 is within the specified range. If it is not within the specified range, in step 10, a fade alarm is displayed on the alarm display device 10, and in step 12 Go to. When the brake temperature is within the specified range, the fade alarm display of the alarm display device 10 is canceled in step 11, and the process proceeds to step 12. That is, in steps 9 to 11, when the temperature of the main braking device 14 rises, control is performed to warn the driver that the main braking device is in a state where the main braking device is likely to cause a fade.

In step 12, the brake pedal operation amount is detected by the pedal sensor 1 and the brake air pressure is detected by the air pressure sensor 4. In step 13, the target braking force is calculated from the brake pedal operation amount. In step 14, it is judged whether or not the target braking force can be achieved only by the auxiliary braking device. If the target braking force can be achieved, in step 15, a drive signal for the auxiliary braking device is generated, and in step 16, the operation and alarm of the auxiliary braking device are activated. Display device 10
After the auxiliary brake operation is displayed on the screen, the process returns to step 2.

If it is determined in step 14 that the target braking force cannot be achieved by the auxiliary braking device alone, the process proceeds to step 17. In step 17, the target brake air pressure is calculated, and in step 18,
It is determined whether the target brake air pressure is higher than the air tank air pressure. If not, the routine proceeds to step 20. On the other hand, when it is high, in step 19, the target brake air pressure is made equal to the air tank air pressure. In steps 18 to 19, step 21 described later is performed.
~ Pre-processing for detecting abnormality of the electronically controlled braking device in step 23 is performed.

In step 20, the solenoid valve 7 is operated to generate a braking force. In step 21, it is judged whether or not the brake air pressure reaches the target brake air pressure within a fixed time. If it reaches, it is judged that the braking is normally performed, and the process returns to step 2. On the other hand, if the target brake air pressure is not reached within the fixed time, it is determined that some failure or the like has occurred in the brake system, and in step 22, the alarm display device 10 displays an alarm display indicating that the electronically controlled brake device is abnormal. 23, solenoid valve for emergency stop 1
After activating 2 to stop the vehicle, the procedure returns to step 2. That is, in steps 21 to 23, when some abnormality occurs in the brake system, emergency control is performed to stop the vehicle on the spot in order to ensure safety.

In the process of calculating the braking force from the operation amount of the brake pedal (step 13 in FIG. 4), the braking force map for the pedal depression angle is used as shown in FIGS. 5 (a) and 5 (b). It is also possible to determine at what rate the auxiliary braking device should be used. In addition, the invention according to claim 2 relates to step 1 in FIG. 4 for each wheel of the system for distributing the braking force of the vehicle.
In the process of 4, the process is the same as the invention according to claim 1 except the process of determining whether the distributed braking force can be achieved only by the auxiliary braking device instead of the target braking force. .

In the above case, the processing of steps 12 to 13 in FIG. 4 is unnecessary, but in step 13, the processing is calculated instead of calculating the target braking force from the operation amount of the brake pedal. For the braking force, a braking force map as shown in FIGS. 5A and 5B may be used to determine at what ratio the auxiliary braking device is used.

[0023]

As described above, according to the first aspect of the invention, when the braking force is small, the auxiliary braking device is used, and when the braking force is large, at least the auxiliary braking device and the main braking device are used. Since the main braking device is operated, it is possible to suppress the fade due to the temperature rise of the main braking device and reduce the wear of the pad or the lining, and improve the safety and maintainability of the vehicle.

According to the second aspect of the invention, when the braking force distributed to each wheel of the system for distributing the braking force of the vehicle is small, the auxiliary braking device is used and when the distributed braking force is large. Since at least the main braking device is operated among the auxiliary braking device and the main braking device, the load on the main braking device of the wheel having a large braking force distribution is reduced, and the fade due to the temperature rise of the main braking device is suppressed. Also, the wear of the pad or the lining can be reduced, and the safety and maintainability of the vehicle can be improved.

Further, since the auxiliary brake device is used more frequently, the consumption of air used in the main brake device can be reduced and the economical efficiency can be improved.

[Brief description of drawings]

FIG. 1 is an overall system configuration diagram of an embodiment of the present invention

FIG. 2 is a control block diagram of the above embodiment.

FIG. 3 is a flowchart showing the control contents of the above embodiment.

FIG. 4 is a flowchart showing the control contents of the above embodiment.

FIG. 5 An example of a braking force map with respect to the brake pedal depression angle

[Explanation of symbols]

 1 Brake pedal sensor 2 Control device 3 Air pressure sensor 4 (4a-4d) Air pressure sensor 5 (5a-5d) Temperature sensor 8 Auxiliary brake device

Claims (2)

[Claims] 1. In a vehicle using both an auxiliary brake device and an air-type main brake device, a brake pedal operation amount detecting means for detecting an operation amount of a brake pedal and an air pressure of an air tank in an operating air circuit of the main brake device are detected. An air tank air pressure detection means, and a brake air pressure detection means for detecting the brake air pressure of the main brake device,
Brake temperature detecting means for detecting the temperature of the brake of the main brake device, and brake control means for controlling the main brake device of the vehicle based on the detected brake pedal operation amount, air tank air pressure, brake air pressure and brake temperature. When the braking force is small, the auxiliary braking device is included, and when the braking force is large, the auxiliary braking device and the brake switching control means for activating at least the main braking device of the main braking device are included. A characteristic vehicle braking device. 2. The braking device for a vehicle according to claim 1, wherein the main braking device distributes a braking force.