JPH09136625A - Braking device for combination of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply required braking pressure for each axle or wheel of respective trailers at a proper braking timing without a braking lag due to piping length from a front trailer to a rear frailer, in combination of vehicle provided with a plurality of trailers to be towed subsequent to a tractor. SOLUTION: A brake pressure modulator 9 which has a solenoid valve and its control system is disposed for each axle or wheel as a means for controlling brake pressure to the brake cylinders of a tractor and respective trailers. A pedal angle sensor for detecting the pedaling angle of a brake pedal, and a control unit 15 for transmitting the control command value of braking pressure to the respective modulators 9 from the detected value through a serial communication line 14 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking system for a combination vehicle.

[0002]

2. Description of the Related Art A connected vehicle is generally long and has piping at the connecting portion, so that there is a delay before the braking force acts on the trailer, and the jack knife phenomenon in which the connecting point of the vehicle bends is likely to occur. There was a point. for that reason,
In Japanese Patent Publication No. 4-33659, a trailer is provided with a dolly equipped with a power unit (engine) and its auxiliary braking device, and the auxiliary braking device of the dolly is activated during braking, and then the auxiliary braking device of the tractor is activated. What has been done is proposed.

[0003]

By the way, with respect to the service brake, the braking pressure supplied through the brake valve interlocking with the brake pedal has been conventionally distributed to the trailing vehicle. As the number of vehicles increases and the length of the brake piping increases, a longer delay time occurs in the braking timing from the front vehicle to the rear vehicle. Therefore, there is a possibility that a rear-end vehicle is likely to generate a rear-end collision impact during braking, and the jack knife phenomenon may impair the stability of the vehicle.

The present invention aims to solve such problems.

[0005]

According to a first aspect of the present invention, in a combination vehicle having a plurality of towed vehicles following one tow vehicle, a solenoid valve is used as a means for controlling a braking pressure applied to a brake cylinder of a wheel. And a brake pressure modulator incorporating the control system are arranged for each axle or each wheel, while means for detecting the stepping angle of the brake pedal and the control command value of the braking pressure to each modulator from this detected value are serial communication line. A control unit is provided for transmitting via.

According to a second aspect of the present invention, in the first aspect of the present invention, the tank and the compressor of the towing vehicle are used as the main pressure supply source, and the sub-tank that stores the pressure of the main pressure supply source in each towed vehicle and supplies it to the brake pressure modulator. To provide.

According to a third aspect of the invention, in the first aspect of the invention, the towing vehicle and each towed vehicle are provided with independent tanks and compressors as main pressure supply sources for each vehicle.

According to a fourth aspect of the invention, the control unit in the first aspect of the invention issues a control command of the braking timing to each of the brake pressure modulators so that the braking is effected in order from the rear vehicle to the front vehicle in accordance with the connecting order of the vehicles. It has a function to send a value.

In the fifth invention, the control unit in the fourth invention has a function of calculating the changing speed of the pedal depression angle detection signal and correcting the braking timing control command value in accordance with the calculated speed. .

According to a sixth aspect of the present invention, in the first aspect, a brake valve that interlocks with the brake pedal, a backup circuit that guides tank pressure to each brake pressure modulator via the brake valve, and a brake circuit in each brake pressure modulator are provided. Detects the control pressure of the backup solenoid valve and each brake pressure modulator that opens the passage that connects the input port of the backup circuit to the output port of the solenoid valve for braking pressure control, and opens it when the modulator drive power is off and closes it when it is on. Means, means for determining the presence or absence of an abnormality from the detection signal and the control command value of the braking pressure, and means for turning off the drive power supply of the brake pressure modulator subject to the abnormality determination.

[0011]

According to the first aspect of the present invention, when the control command value of the braking pressure is transmitted from the control unit through the serial communication line, each brake pressure modulator applies the braking pressure corresponding to the control command value to the brake cylinder. Supply. In this case, since the brake pressure modulator that controls the braking pressure for each wheel or each axle is provided, the braking delay does not increase from the front vehicle to the rear vehicle, and each axle or each wheel of each vehicle does not The braking force can be generated with proper control pressure and timing.

According to the second invention, the supply pressure to the brake pressure modulator of each towed vehicle can be stably maintained by the sub tanks.

According to the third aspect of the invention, even if one of the main pressure piping systems fails, the tank and the compressor are provided independently for each vehicle, so that the braking pressure of the entire combined vehicle is not lost. It is possible to secure good safety and reliability.

According to the fourth aspect of the present invention, since the braking force is sequentially generated from the rear vehicle to the front vehicle, the front vehicle stops so as to drag the rear vehicle, so that the jack knife that bends at the connecting point of the vehicle is used. The phenomenon can be effectively prevented.

According to the fifth aspect of the invention, when the control command value of the braking timing is corrected to be small according to the changing speed of the pedal angle, the braking force is synchronously generated in the entire combined vehicle. The braking distance can be shortened.

According to the sixth aspect, when it is determined that the brake pressure modulator is abnormal, the modulator power supply is turned off. As a result, the solenoid valve for controlling the braking pressure is stopped, but the solenoid valve for backup opens the passage, so that pressure corresponding to the pedal depression angle is supplied from the brake valve to the brake cylinder via the brake pressure modulator. . That is, it is possible to secure a fail-safe against a failure of the brake pressure modulator.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an external view showing an example of a combination vehicle, and FIG. 2 is a schematic view of a brake system thereof. Reference numeral 1 denotes a tractor of a combination vehicle, in which a semi-trailer 2 is connected to a rear portion of the tractor 1 and two full trailers 4 having a dolly 3 behind the tractor 1 are sequentially connected. A main tank 5 and an engine-driven compressor 6 are mounted on the tractor 1, and a pedal angle sensor (1 in FIG. 5) for detecting a pedal angle (stroke) of the brake valve 7 for controlling backup air.
0) is provided. FIG. 3 shows an example of operating characteristics of the brake valve.

Brake cylinders 8 are arranged on the wheels of the tractor 1 and the trailers 2, 4, and these cylinders 8 are connected to a brake pressure modulator 9 for each axle. The brake pressure modulator 9 has two input ports for one output port, and the main air circuit 11 is connected to one input port and the backup air circuit 12 is connected to the other input port.

The main air circuit 11 is connected to the main tank 5 of the tractor 1, and sub-tanks 13 for accumulating the pressure from the main tank 5 are provided in branch circuits to the brake pressure modulators 9 of the trailers 2 and 4, respectively. The brake valve 7 is connected to the main tank 5 and controls the supply pressure to the backup circuit 12 according to the pedal angle.

A control unit 15 is connected to each brake pressure modulator 9 via a serial communication line 14. The control unit 15 sets the braking pressure and the braking timing for each axle based on the detection signal of the pedal angle sensor 10, and transmits these control command values to each brake pressure modulator 9 via the serial communication line 14. Each brake pressure modulator 9 receives the braking pressure and the control command value of the braking timing from the serial communication line 14, and controls the braking pressure to the brake cylinder 8 after the lapse of each delay time.

Each brake pressure modulator 9 transmits the detected value (actual pressure) of the braking pressure to the control unit 15 via the serial communication line 14. The control unit 15 receives the actual pressures from the serial communication line 14, determines whether or not these are in the normal range, and if even one is abnormal, turns off the drive power source of the brake pressure modulator 9 to be determined.

As shown in FIG. 4, the brake pressure modulator 9 includes a solenoid valve 18 for controlling the pressure from the input port 16a of the main air circuit 11 to the output port 17, and an input of the backup air circuit 12 from the input port 16b to the output port 17. Solenoid valve 19 for opening and closing the passage, and these solenoid valves 18, 1
9, valve driving means 20, a pressure sensor 21 for detecting the pressure of the output port 19, a serial communication means 22 for exchanging signals with the control unit 15,
The target pressure setting means 23 for setting the target value of the braking pressure from the received data, and the solenoid valve 18 of the main air circuit PID via the valve drive unit 20 so that the pressure detected by the pressure sensor 21 matches the target pressure. And a pressure control means 24 for controlling. Solenoid valve 19 for backup air circuit
Is closed when the power source of the valve drive means 20 is turned on and is opened when the power source is turned off.

As shown in FIG. 5, the control unit 15 inputs the processing means 25 for reading the detection signal of the pedal angle sensor 10 and the braking pressure setting for setting the braking pressure according to the processing signal (pedal angle signal) for each axle. Means 26, braking timing setting means 27 for setting proper braking timing for each axle, serial communication unit 28 for exchanging signals with the brake pressure modulator 9, and braking for each axle based on the received data. A modulator abnormality determining means 29 for determining whether the pressure is within the normal range and a fail safe means 30 for turning off the drive power source of the brake pressure modulator 9 to be determined if there is even one abnormality are provided.

The braking pressure setting means 26 stores a control map as shown by (a) in the memory in the memory, and by searching this data (table lookup),
A standard value of the braking pressure according to the detection signal of the pedal angle sensor 10 is obtained. Then, the correction coefficient is set for each axle,
By multiplying these by the standard value of the braking pressure, the braking pressure is calculated for each axle. When the vehicle load (load) changes, the required braking pressure also changes, so a load sensor (not shown) that detects the load of each vehicle is provided, and the correction coefficient for each axle is determined according to the detection signal. Change. The reference value of the braking pressure may be obtained by calculation processing of a relational expression, without depending on the data search.

The braking timing setting means 27 is the tractor 1
The delay time is set to sequentially generate the braking force from the rear vehicle to the front vehicle in accordance with the connection order including the. Then, the rate of change is calculated from the detection signal of the pedal angle sensor 10, and each delay time is corrected to a small value according to this calculated value. As a result, the delay time at the time of sudden braking is shortened, and the brake cylinders 8 of the respective wheels are operated synchronously.

6 and 7 are flow charts for explaining the control contents performed by the control unit 15. FIG. 6 shows a main program repeatedly executed at a predetermined control cycle, and FIG. 7 shows a processing request from a main control timer. Accordingly, it is an interrupt process executed every predetermined time.

In FIG. 6, the detection signal of the pedal angle sensor 10 is read, and the braking pressure is set for each axle from the detection signal (step 1.01, step 1.0).
2). The braking pressure of each axle is calculated by obtaining the standard value of the braking pressure according to the pedal angle as described above and multiplying this standard value by the correction coefficient of each axle according to the load capacity. Next, the braking timing is set for each axle (step 1.03). By correcting the delay time set for each vehicle according to the changing speed of the pedal angle, the braking timing for each axle is determined. Then, the control command values of the braking timing and the braking pressure are output for each axle, and the serial data is transmitted to the brake pressure modulator 9 (step 1.04, step 1.05).

In FIG. 7, the detection signal of the pressure sensor 10 transmitted from the brake pressure modulator 9 via the serial communication line 14 is received (step 2.0).
1). Then, based on the detection signal of the pressure sensor 10,
Whether or not the control pressure is within the normal range is determined for each axle, and if there is any abnormality, the drive power source of the brake pressure modulator that is the subject of determination is turned off (step 2.02, step 2.03). As a result, when the driving power of the brake pressure modulator 9 is turned off, the solenoid valve 18 of the main air circuit 11 is closed and the solenoid valve 19 of the backup air circuit 12 is opened, so that the control pressure from the brake valve 7 to the brake cylinder 8 is applied. Supplied with. That is, it is possible to secure a fail-safe against a failure of the brake pressure modulator 9.

8 and 9 show the brake pressure modulator 9
8 is a flowchart illustrating the control content performed in FIG.
Is a main program repeatedly executed in a predetermined control cycle, and FIG. 9 is an interrupt process executed in response to a processing request from the main control timer.

In FIG. 8, the detection signal of the pressure sensor 10 is read, the deviation between the detected pressure and the target value of the braking pressure is calculated to obtain the PID control amount, and the control amount is converted into a current value to obtain the electromagnetic value. Control the current to the valve (Step 3.0
1 to 3.06). As a result, the pressure supplied to the brake cylinder 8 is controlled so as to match the target value of the control pressure, and an appropriate braking force is generated for each axle at a predetermined braking timing.

In FIG. 9, the control unit 1
5, the target value is set from the control command value of the braking pressure, and the setting is updated if necessary (steps 4.01 to 4.03). And the detection signal of the pressure sensor 10 (feedback signal of the actual pressure)
Is transmitted to the control unit 15 as serial data (step 4.04).

With this configuration, since the brake pressure modulator 9 for controlling the braking pressure for each wheel or each axle is provided through the serial communication with the control unit 15, the length of the pipe from the front vehicle to the rear vehicle is reduced. There is no braking delay involved, and the required braking pressure can be supplied at appropriate braking timing for each axle or each wheel of each vehicle.

The braking force of each vehicle is sequentially generated from the rear vehicle to the front vehicle in accordance with the delay time, and the tractor is stopped so as to drag the trailer. Therefore, the jack knife phenomenon during braking is effectively performed. It can be prevented. During sudden braking, the braking force is applied to each vehicle synchronously by correcting the delay time, so that the braking distance can be shortened while suppressing the jack knife phenomenon.

Since the sub-tank 13 is provided for each brake pressure modulator 9 of each trailer 2, 4 with respect to the main tank 5 of the tractor 1, the main tank 5 is supplied to the brake pressure modulator 9 without increasing the capacity of the main tank 5. Each pressure can be stably maintained. If the brake pressure modulator 9 is provided for each wheel, the braking state of the combined vehicle can be controlled more finely.

In order to prevent a delay in the supply of backup air,
A relay valve that operates using the pressure of the backup air circuit 12 as a pilot pressure is provided immediately upstream of each brake pressure modulator 9, and the pressure of the main air circuit 11 is supplied to the input port 16b of the modulator 9 in accordance with the pilot pressure. Is also good.

FIG. 10 shows another embodiment. Separately from the main tank 5 and the compressor 6 of the tractor 1, each of the trailers 2 and 4 has a tank 31 and an independent tank 31 as a main air supply source to the brake pressure modulator 9. A compressor 32 is provided. In this case, the compressor 32 is of an electric type operated by the motor 33, but may be driven by rotation of the wheels of the trailers 2 and 4.

According to this, 1 of the main air system of the combined vehicle
Even if one fails, the main air of the entire connected vehicle will not fail and high safety and reliability can be secured. The same parts as those in FIG. 2 are designated by the same reference numerals, and the duplicated description will be omitted.

[0038]

According to the first aspect of the invention, in a combination vehicle including a plurality of towed vehicles following one tow vehicle, an electromagnetic valve and its means are provided as means for controlling braking pressure applied to brake cylinders of wheels. A brake pressure modulator with a built-in control system is arranged for each axle or each wheel, while means for detecting the depression angle of the brake pedal and the braking pressure control command value to each modulator from this detected value are sent via a serial communication line. Since a control unit for sending by
There is no braking delay associated with the length of the pipe from the front vehicle to the rear vehicle, and it is possible to supply the required braking pressure for each axle or each wheel of each vehicle at appropriate braking timing.

According to the second invention, in the first invention, the tank and the compressor of the towing vehicle are used as the main pressure supply source, and the pressure of the main pressure supply source is accumulated in each towed vehicle and supplied to the brake pressure modulator. Since a sub-tank is installed, without increasing the size of the towing vehicle tank,
It is possible to stably secure the supply pressure to the brake pressure modulator of each towed vehicle.

According to the third aspect of the invention, in the first aspect of the invention, the towing vehicle and each towed vehicle are provided with independent tanks and compressors as main pressure supply sources for each vehicle.
Even if one of the main pressure piping systems fails, the braking pressure of the entire combined vehicle does not fail, and good safety and reliability can be secured.

According to the fourth aspect of the invention, the control unit of the first aspect of the invention issues a braking timing control command to each of the brake pressure modulators so that braking is effected in order from the rear vehicle to the front vehicle in accordance with the connection order. Since the vehicle has a function of transmitting the value, the front vehicle stops like dragging the rear vehicle during braking, so that the jack knife phenomenon or the like can be effectively prevented.

According to the fifth aspect of the invention, the control unit of the fourth aspect of the invention calculates the speed of change from the pedal depression angle detection signal and corrects the braking timing control command value in accordance with this calculated value. Since the control command value of the braking timing is corrected to be small, the braking force of each vehicle is generated synchronously, so that the braking distance at the time of sudden braking can be shortened.

According to a sixth invention, in the first invention, a brake valve interlocked with the brake pedal, a backup circuit for guiding the tank pressure to each brake pressure modulator via the brake valve, and each brake pressure modulator. The solenoid valve for backup that closes the passage that connects the input port of the backup circuit with the output port of the solenoid valve for braking pressure control by turning off the drive power of the modulator, and the control pressure of each brake pressure modulator Since the means for detecting, the means for determining the presence or absence of an abnormality from the detection signal and the control command value of the braking pressure, and the means for turning off the drive power source of the brake pressure modulator subject to the abnormality determination, the brake pressure modulator The solenoid valve for braking pressure control is stopped in the event of an abnormality, but the solenoid valve for backup is To open the, the pressure corresponding to the pedal depression angle from the brake valve is supplied via a brake pressure modulator to the brake cylinder can be ensured failsafe against failure of the brake pressure modulator.

[Brief description of the drawings]

FIG. 1 is an external view of a combination vehicle that represents an embodiment of the present invention.

FIG. 2 is a schematic diagram of a brake system of the same.

FIG. 3 is an operating characteristic diagram of the brake valve of the same.

FIG. 4 is a block diagram of a brake pressure modulator.

FIG. 5 is a block diagram of a control unit of the same.

FIG. 6 is also a main control flow of the control unit.

FIG. 7 is likewise an interrupt flow of the control unit.

FIG. 8 is a main control flow of the brake pressure modulator.

FIG. 9 is also an interrupt flow of the brake pressure modulator.

FIG. 10 is a schematic diagram of a brake system that represents another embodiment.

[Explanation of symbols]

 1 tractor 2, 4 trailer 3 dolly 5 main air tank 7 brake valve 8 brake cylinder 9 brake pressure modulator 10 pedal angle sensor 11 main air circuit 12 backup circuit 13 sub tank 14 serial communication line 15 control unit 18 solenoid valve of main air circuit 19 backup Circuit solenoid valve 20 Valve driving means 21 Pressure sensor 22 Serial communication means 23 Target pressure setting means 24 Pressure control means 25 Pedal angle signal input processing means 26 Braking pressure setting means 27 Braking timing setting means 28 Serial communication means 29 Modulator abnormality judgment Means 30 Fail-safe means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuyoshi Okada 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Toru Takagi 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd.

Claims (6)

[Claims] 1. A combined vehicle including a plurality of towed vehicles following one tow vehicle, a brake pressure modulator having a solenoid valve and a control system thereof as means for controlling a braking pressure applied to a brake cylinder of a wheel. While arranging for each axle or each wheel, a means for detecting the depression angle of the brake pedal and a control unit for transmitting the control command value of the braking pressure to each modulator from this detected value via the serial communication line are provided. A braking device for a combined vehicle characterized by the above. 2. A sub-tank for storing the pressure of the main pressure supply source in each towed vehicle and supplying it to the brake pressure modulator, using the tank and compressor of the towing vehicle as the main pressure supply source. The braking device according to 1. 3. The braking device according to claim 1, wherein the towing vehicle and each towed vehicle are provided with independent tanks and compressors for each vehicle as main pressure supply sources. 4. The control unit has a function of transmitting a control command value of a braking timing to each brake pressure modulator so that braking is effected in order from a rear vehicle to a front vehicle in accordance with a vehicle connection order. The braking device according to claim 1, which is characterized in that 5. The control unit is provided with a function of calculating a changing speed of the pedal depression angle detection signal from the detection signal and correcting a braking timing control command value in accordance with the calculated value. The described braking device. 6. A brake valve interlocking with a brake pedal, a backup circuit for guiding tank pressure to each brake pressure modulator via the brake valve, and an input port of the backup circuit in each brake pressure modulator for controlling the braking pressure. The solenoid valve for backup that opens the passage communicating with the output port of the solenoid valve of the modulator when the drive power of the modulator is off and closes it when it is on, the means for detecting the control pressure of each brake pressure modulator, and the detection signal and the braking pressure Means for determining the presence or absence of an abnormality from the control command value,
The braking device according to claim 1, further comprising means for turning off a driving power source of the brake pressure modulator that is the abnormality determination target.