JP2007196732A - Vehicular brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular brake device capable of preventing a rollover or the like by accurately and properly detecting a dangerous state without requiring additional installation of an electronic component and an electronic control. <P>SOLUTION: Ride height detectors 13_L, 13_R arranged on a vehicle (for example, a tractor) frame 1_1 output air pressures AP13_L, AP13_R corresponding to the vehicle height for each of right and left rear wheels 1_3L, 1_3R. A pressure regulating valve 14 always inputs, for example, a maximum air pressure MAX_AP of an air tank, inputs the air pressures AP13_L, AP13_R, and outputs the maximum air pressure MAX_AP when a pressure difference between the air pressures AP13_L and AP13_R exceeds a predetermined threshold. In this case, instead of an operation state of a foot brake, the maximum air pressure MAX_AP is forcibly supplied to the brake portion as an operation pressure through a double check valve, or the corresponding operation pressure input to a trailer control valve is supplied to the brake portion on the trailer side, thus generating a brake force. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle brake device, and more particularly to a device that detects a rollover danger state in a vehicle such as a tractor that pulls a trailer and prevents rollover.

  Examples of the vehicle rollover prevention technology as described above include those according to conventional examples [1] to [4] shown below.

Conventional example [1]:
Calculate the roll angle and roll angular velocity using the electronic control unit from the output of the height sensor installed between the left and right chassis and the suspension, and calculate the roll angle and roll angular velocity that are expected to exceed the rollover limit. When threshold 1 is exceeded, an alarm is issued to prompt the driver to slow down the vehicle speed, and when threshold 2 near the limit is exceeded, deceleration control is performed from the electronic control unit to prevent rollover (for example, , See Patent Document 1).

Conventional example [2]:
Based on the output of the vehicle speed sensor and lateral acceleration sensor installed in the vehicle, whether the vehicle speed exceeded a certain threshold and the lateral acceleration exceeded a certain threshold using a program control circuit including a CPU for a predetermined time If it continues, it is determined that there is a risk of vehicle rollover, and the vehicle is automatically decelerated to prevent rollover (see, for example, Patent Document 2).

Conventional example [3]:
It was judged that there was a risk of rollover from the map that associates the output of the vehicle speed sensor, steering angle sensor, and load sensor installed in the vehicle with the vehicle speed, steering angle, load capacity and rollover risk area prepared in advance. In some cases, an alarm is issued to prompt the driver to decelerate and prevent rollover (see, for example, Patent Document 3).
JP 2002-166745 A JP 2001-58563 A Japanese Patent Laid-Open No. 10-100773

  Regarding the above-mentioned Patent Documents 1 and 2, electronic control using an electronic control unit or a program control circuit is performed, respectively, and in particular, Patent Document 2 describes new electronic components such as a rotation sensor and a lateral acceleration sensor. It needs to be installed. When performing such electronic control, adjustment is required for each type and type of vehicle, and the adjustment requires a great deal of time and associated costs. In addition, since electronic parts are precision machines, they are fragile and their mounting is not excellent in terms of cost performance.

  Furthermore, in both Patent Documents 1 and 2, since the braking force by the deceleration control is intermittent, the driver feels uncomfortable or, in extreme cases, the driver is surprised and dangerous such as a sudden handle. There is a possibility of driving operation.

  With respect to the above-mentioned Patent Document 3, it is merely an alarm generation device, and the actual rollover prevention operation is left to the driver, and rollover prevention may not be possible unless the driver notices it. Even if the warning is replaced with the braking operation as it is, the vehicle posture is predicted from the vehicle speed, the steering angle, and the load, and the accuracy of the rollover prevention control is not possible because the accuracy is low.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vehicle brake device that does not require mounting of new electronic components or electronic control and can accurately detect a dangerous state and prevent rollover or the like. To do.

 [1] In order to achieve the above object, a vehicle brake device according to the present invention includes a foot brake operating unit, an air tank, and a vehicle frame that is installed in a vehicle frame and that corresponds to each of the left rear wheel and the right rear wheel. A vehicle height position detecting unit that detects a vehicle height position and outputs a first air pressure and a second air pressure respectively corresponding to the detected vehicle height position, and inputs a predetermined air pressure of the air tank, A pressure adjusting valve that outputs a predetermined air pressure when a pressure difference between the first air pressure and the second air pressure exceeds a predetermined threshold value; Outputs a control air pressure from the foot brake actuating portion as it is, and when the predetermined air pressure is received from the pressure adjusting valve, a double check valve that switches to forcibly output the predetermined air pressure; Connect to check valve Is, the control air pressure or is characterized in that a brake unit to provide a braking force corresponding receiving the predetermined air pressure as the operating pressure in the rear wheel.

  As described above, the vehicle brake device according to the present invention does not require electronic components such as a rotation sensor and a lateral acceleration sensor and does not require electronic control, and accurately detects a rollover danger state accurately and automatically. It is possible to prevent a rollover by generating a braking force on the rear wheel.

 [2] The vehicle brake device according to the present invention is installed on a tractor-side foot brake operating unit, a tractor-side air tank, a trailer-side air tank, a trailer-side brake unit, and a frame of the tractor. A vehicle height position detecting unit that detects a vehicle height position of the tractor frame with respect to each of the left rear wheel and the right rear wheel and outputs a first air pressure and a second air pressure respectively corresponding to the detected vehicle height position. And a predetermined air pressure of the tractor-side air tank and a first air pressure and a second air pressure are input, and a pressure difference between the first air pressure and the second air pressure exceeds a predetermined threshold value. The pressure adjusting valve that outputs the predetermined air pressure, and the normal control air pressure from the foot brake operating part is output as it is, and when the predetermined air pressure is received from the pressure adjusting valve, the predetermined air pressure is output. Force pressure A double check valve that switches to output to the tractor side air tank, and the tractor side air tank that is connected to the double check valve and that corresponds to the control air pressure or the predetermined air pressure output from the double check valve When the air pressure output from the trailer control valve is received as a signal pressure, it is disposed between the trailer control valve that outputs the air pressure and the trailer side air tank, the trailer side brake unit, and the trailer control valve. And a relay valve that supplies air pressure of the trailer-side air tank as an operating pressure to the trailer-side brake portion to generate a braking force.

  In general, the connecting point of a vehicle composed of a tractor and a trailer is located behind the center of gravity of the tractor. Therefore, when braking force is generated on both the tractor and the trailer during turning, the braking of the tractor When it becomes larger than braking, it becomes a state of jackknife phenomenon in which the tractor and the trailer bend each other, and it is easy to roll over.

  However, in the vehicle brake device according to the present invention, it is possible to generate a braking force only on the trailer side, so that a force toward the linear state can be applied to the tractor and the trailer during turning while decelerating. As a result, the state of the jackknife phenomenon can be avoided.

  Further, since the relay valve is disposed on the trailer side in some vehicles, in this case, the present invention can be applied without changing the brake air control system on the trailer side.

 [3] Also, in the above [1] or [2], the pressure adjusting valve has an input port for inputting the predetermined air pressure, the first air pressure, and the second air pressure, and two discharge ports. And the first and second elastic bodies fixed on the chamber wall surfaces on both sides and having the same elastic modulus, and the first and second elastic bodies in the normal time when the first air pressure and the second air pressure are equal to each other. When the elastic force is balanced, the discharge port is closed, and when the pressure difference between the first air pressure and the second air pressure exceeds the threshold value, the elastic force is not balanced, thereby the discharge port. An input chamber having a first spool valve that moves so as to discharge the predetermined air pressure from the discharge port, an input port communicating with the discharge port, an output port, an air release port, and a chamber wall surface A third elastic body fixed to the base, and in the normal time, the input port is closed by the elastic force of the third elastic body and the atmosphere is opened. When the predetermined air pressure is received from the input port via the exhaust port, the air release port is closed against the elastic force of the third elastic body and the air release port is closed. An output pressure chamber having a second spool valve that moves to output a predetermined air pressure from the output port may be provided.

  This will be described using the operating principle of the pressure regulating valve of the present invention shown in FIG. First, as a structure, the pressure adjustment valve 14 may be collectively referred to as, for example, a maximum air pressure MAX_AP as a predetermined air pressure of the air tank, and vehicle height position detectors 13_L and 13_R (hereinafter, reference numeral 13) disposed in the vehicle frame 1_1. ) Output air pressures AP13_L and AP13_R (hereinafter collectively referred to as AP13), respectively, are input ports 14_2C, 14_2L, and 14_2R, two discharge ports 14_3L and 14_3R, and chambers on both sides. An input pressure chamber 14_1 having elastic bodies 14_4L and 14_4R fixed to the wall 14_12 surface and having the same elastic coefficient, and a spool valve 14_5 connected to the elastic bodies 14_4L and 14_4R, and one outlet communicating with the discharge ports 14_3L and 14_3R An output port 14_7, an output port 14_8, an air release port 14_9, an elastic body 14_10 fixed to the surface of the chamber wall 14_12, and an output pressure chamber 14_6 having a spool valve 14_11 connected to the elastic body 14_10. Yes.

  In operation, since the air pressures AP13_L and AP13_R are equal to each other when the vehicle is traveling normally, the elastic forces of the elastic bodies 14_4L and 14_4R inside the input pressure chamber 14_1 are balanced as shown in FIG. Thus, the spool valve 14_5 closes the discharge ports 14_3L and 14_3R, and the spool valve 14_11 closes the input port 14_7 communicating with the discharge ports 14_3L and 14_3R and the atmosphere opening port 14_9 by the elastic force of the elastic body 14_10 inside the output pressure chamber 14_6. Is opened and communicated with the output port 14_8, the pressure adjustment valve 14 outputs nothing.

  On the other hand, when the vehicle is in danger of overturning while turning, etc., the pressure difference between the air pressure AP13_L and the air AP13_R becomes large (in the example shown, AP13_L << AP13_R ) As a result, the elastic force of the elastic bodies 14_4L and 14_4R is not balanced, so the spool valve 14_5 moves to the left to open the discharge port 14_3L, for example, and discharges the maximum air pressure MAX_AP from the discharge port 14_3L . In this case, the spool valve 14_11 that has received the maximum air pressure MAX_AP from the input port 14_7 of the output pressure chamber 14_6 via the exhaust port 14_3L moves to the right against the elastic force of the elastic body 14_10. 14_9 is closed, and the input port 14_7 and the output port 14_8 are made to communicate with each other, so that the pressure adjustment valve 14 outputs the maximum air pressure MAX_AP from the output port 14_8.

  As described above, the pressure adjustment valve 14 does not require electronic control, can have a mechanical and simple structure, and can accurately detect a dangerous state such as rollover with high accuracy.

 [4] In the above [3], the threshold value is moved from the normal position to the position where at least one of the discharge ports is opened from the closed state by the pressure difference. It is possible to correspond to the movement distance necessary to make it.

  That is, for example, when the interval between the discharge ports 14_3L and 14_3R shown in FIG. 1 is set to be narrower than the illustrated state, the spool valve 14_5 is a distance shorter than the moving distance L as the threshold shown in FIG. It is possible to open the discharge port 14_3L by moving it against the elastic force of the elastic body 14_L, and conversely, the interval between the discharge ports 14_3L and 14_3R is wider than the illustrated state When installed, the spool valve 14_5 needs to move a distance longer than the moving distance L in order to open the discharge port 14_3L.

  In this way, depending on the installation positions of the discharge ports 14_3L and 14_3R, it is necessary to move the spool valve 14_5 against the elastic force of the elastic body 14_4L or 14_4R, the pressure difference that the air pressure AP13_L and the air pressure AP13_R must satisfy It is possible to correspond to a long moving distance.

  Therefore, when the present invention is applied to a different vehicle, it is only necessary to adjust the installation position of the discharge port according to the type and model of the vehicle, so that the adjustment can be easily performed.

According to the present invention, there is no need to mount electronic components such as a rotation sensor and a lateral acceleration sensor and electronic control, and it is possible to detect a dangerous state accurately and accurately to prevent a rollover or the like. It is possible to reduce the time required for adjustment for each type and type and improve cost performance.
In addition, when the present invention is applied to a vehicle composed of a tractor and a trailer, a braking force can be generated only on the trailer side, thereby preventing a jackknife phenomenon and preventing the vehicle from overturning. be able to. Further, in the case of a vehicle in which the relay valve is arranged on the trailer side, it can be applied without changing the brake air control system on the trailer side, thereby improving the operational freedom and operating rate of the trailer. .

  Further, since the pressure adjustment valve has a mechanical and simple structure, it can be easily applied to and adjusted in different types and types of vehicles.

  Embodiments [1] and [2] of the vehicle brake device according to the above inventions [1] and [2] will be described below with reference to FIGS. The embodiment [1] is applied to a single vehicle, and the embodiment [2] is applied to a connected vehicle including a tractor and a trailer.

  In Examples [1] and [2], the pressure adjustment valve 14 shown in FIG. 1 is used in common.

Example [1]: FIGS. 2 and 3 (single vehicle)
[1.1] Example of overall configuration: Fig. 2
First, the overall configuration of the present embodiment [1] will be described with reference to FIG.

  The brake device of the vehicle 1 shown in FIG. 2 includes a foot brake valve 11 that outputs a control air pressure according to the depression force of the foot brake pedal, an air tank 12, and the left rear wheel 1_3L and the right rear wheel 1_3R. While detecting the vehicle height position and outputting the air pressure AP13_L and AP13_R respectively corresponding to the vehicle height position, the vehicle height position detectors 13_L and 13_R, and the predetermined air pressure of the air tank 12, for example, the maximum air pressure MAX_AP is input The pressure adjustment valve 14 for inputting the air pressures AP13_L and AP13_R, the double check valve 15 connected to the foot brake valve 11 and the pressure adjustment valve 14, and the output from the double check valve 15 are received as the operating pressure as a braking force. The brake unit 16 is applied to the rear wheel 1_3 of the vehicle 1.

  Note that the vehicle height position detection unit 13 can use the vehicle height position detection function of LSPV (load sensing proportioning valve) currently installed in many vehicles as it is. There is no need to install a vehicle height sensor or the like.

[1.2] Example of overall operation: Fig. 3
Next, the overall operation of the embodiment [1] will be described with reference to FIG. 2 described above and FIG. 3 showing a part of the configuration of the embodiment [1].

  FIG. 3 (1) shows a case where the foot brake is operated when the vehicle 1 is traveling normally in the embodiment [1], and the air pressures AP13_L and AP13_R output from the vehicle height position detectors 13_L and 13_R are mutually connected. The block diagram in the case of being equal is shown. That is, the control air pressure CP11 from the foot brake valve 11 is supplied as an operating pressure OP from the output port 15_3 to the brake unit 16 via one input port 15_1 of the double check valve 15, and the brake unit 16 is Generate braking force on wheel 1_3.

  At this time, the other input port 15_2 of the double check valve 15 is connected to the pressure adjusting valve 14, but the output port 14_8 of the pressure adjusting valve 14 is connected to the atmosphere opening port 14_9, so that atmospheric pressure is input. It is in a state. Accordingly, the double check valve 15 automatically selects and outputs the control air pressure CP11 from the foot brake valve 11.

  Fig. 2 (2) shows a case where the vehicle 1 falls into a rollover danger while turning, etc., for example, the vehicle height position of the vehicle frame 1_1 with respect to the right rear wheel 1_3R as shown in Fig. 1 (2) is A block diagram when the vehicle frame 1_1 is higher than the vehicle height position of the wheel 1_3L and a large pressure difference is generated between the corresponding air pressure AP13_L and air pressure AP13_R is shown.

  That is, the maximum air pressure MAX_AP of the air tank 12 is input to the pressure adjustment valve 14 through the input port 14_2C, and the air pressures AP13_L and AP13_R are input through the input ports 14_2L and 14_2R, respectively. When the elastic force of the elastic bodies 14_4L and 14_4R is not balanced by the pressure difference between the pressure AP13_L and the air pressure AP13_R, the spool valve 14_5 moves to the left by the movement distance L so as to open the discharge port 14_3L (air When the pressure difference between the pressure AP13_L and the air pressure AP13_R exceeds a threshold value), the maximum air pressure MAX_AP is discharged from the discharge port 14_3L. Although not shown, when the air pressure AP13_L is larger than the air pressure AP13_R and the pressure difference exceeds the threshold value, the spool valve 14_5 moves rightward to open the discharge port 14_3R and the maximum air pressure MAX_AP is increased. Discharge from outlet 14_3R.

  At this time, the spool valve 14_11, which has received the maximum air pressure MAX_AP from the input port 14_7 of the output pressure chamber 14_6 via the exhaust port 14_3L, moves to the right against the elastic force of the elastic body 14_10. 14_9 is closed, and the input port 14_7 and the output port 14_8 are made to communicate with each other. As a result, the pressure adjusting valve 14 outputs the maximum air pressure MAX_AP from the output port 14_8 to the double check valve 15.

  Accordingly, the maximum air pressure MAX_AP is forcibly supplied to the brake unit 16 as the operating pressure OP via the double check valve 15, and the brake unit 16 generates the maximum braking force on the rear wheel 1_3 of the vehicle 1.

  At this time, the input port 15_1 of the double check valve 15 is connected to the foot brake valve 11, but since the maximum air pressure MAX_AP is given from the pressure adjustment valve 14, the foot brake is operated simultaneously. However, the control air pressure CP11 from the foot brake valve 11 is invalidated, and the maximum air pressure MAX_AP from the pressure adjustment valve 14 is automatically selected and output.

  In this way, when a risk of rollover is detected, it is possible to prevent the rollover by automatically generating a braking force on the rear wheel regardless of the operation of the foot brake.

Example [2]: FIGS. 4 to 6 (connected vehicle)
[2.1] Example of overall configuration: Fig. 4
First, the overall configuration of the embodiment [2] will be described with reference to FIG.

  The vehicle brake device applied to the tractor 2 and trailer 3 shown in FIG. 4 includes a foot brake valve 11 that outputs a control air pressure corresponding to the depression force of the foot brake pedal on the tractor 2 side, a tractor side air tank 12, and a tractor. Vehicle height position detectors 13_L and 13_R for detecting the vehicle height position of the tractor 2 for each of the left rear wheel 1_3L and the right rear wheel 1_3R and outputting air pressures AP13_L and AP13_R respectively corresponding to the vehicle height positions; For example, the maximum air pressure MAX_AP is input as the predetermined air pressure of the tractor-side air tank 12, and the pressure adjustment valve 14 for inputting the air pressures AP13_L and AP13_R, and the double check valve connected to the foot brake valve 11 and the pressure adjustment valve 14 15 and the tractor-side air tank 12 and the double check valve 15 are connected to the tractor-side air tank in response to the output from the double check valve 15. The trailer control valve 21 that outputs the air pressure, the trailer side air tank 31, the trailer side brake unit 32, and the trailer control valve 21 are arranged between the trailer control valve 21 and the trailer control valve 21 that receives the air pressure output from the trailer control valve 21 as a signal pressure. A relay valve valve 33 for supplying the air pressure of the side air tank 31 to the trailer side brake unit 32 as an operating pressure and generating a braking force.

  In order to simplify the drawing, the description of the brake unit on the tractor 2 side and the brake air control system related thereto, and the description of the front wheel on the trailer 3 side are omitted.

[2.1.1] Trailer control valve structure and operation: Fig. 5
Next, the overall operation of the embodiment [2] will be described. Before that, the structure and operation of the trailer control valve 21 used in this embodiment will be described with reference to FIG.

  Regarding the structure, as shown in Fig. 1 (1), the trailer control valve 21 is provided with a brake valve (secondary) port 21_1, a brake valve (primary) port 21_2, a parking valve port 21_3, and an air tank port 21_4 as input ports. As an output port, a trailer service port 21_5 and a trailer emergency port 21_6 are provided.

  The trailer-side brake unit 32 is connected to the air piping on the tractor 2 side to ensure safety when not connected to the tractor 2 (when the tractor-trailer is connected). Only when the tractor and trailer are disconnected (when no air pressure is supplied), the brake is forcibly set.

  Next, regarding the operation of the trailer control valve 21, the following braking types (a) to (c) are exhibited as shown in FIG.

(a) Release brake force to trailer (tractor / trailer connected):
When the tractor 2 and trailer 3 are connected and the air pressure from the tractor-side air tank 12 begins to be input to the air tank port 21_4, the signal pressure from the trailer emergency port 21_6 to the trailer-side brake unit 32 passes through the relay valve 33. The brake force is released by the trailer side brake unit 32. As a result, the trailer 3 is ready to travel. Hereinafter, it will be described that the air pressure to the air tank port 21_4 remains input during the connection of the tractor 2 and the trailer 3.

(b) Generation of braking force on trailer by foot brake:
When the control air pressure from the foot brake valve 11 by the foot brake operation is input to the brake valve (secondary) port 21_1 and the brake valve (primary) port 21_2, the control from the trailer service port 21_5 to the trailer side brake unit 32 is performed. A signal pressure corresponding to the air pressure is output via the relay valve 33, and a braking force is generated by the trailer side brake unit 32.

(c) Generation of braking force on trailer by parking brake:
When the control air pressure from the parking brake valve (not shown) by the parking brake operation is input to the parking valve port 21_3 (when the parking valve port 21_3 is at atmospheric pressure), the air pressure input to the air tank port 21_4 is A signal pressure corresponding to the control air pressure is supplied to the service port 21_5 from the trailer service port 21_5 to the trailer side brake unit 32 via the relay valve 33, and the brake force is generated by the trailer side brake unit 32. The

[2.2] Overall operation example: Fig. 6
Next, the overall operation of the embodiment [2] will be described with reference to FIGS. 4 and 5 described above and FIG. 6 which shows a part of the configuration of the embodiment [2].

  FIG. 6 (1) shows the air pressure AP13_L output by the vehicle height position detectors 13_L and 13_R when the foot brake is operated when the tractor 2 and the trailer 3 are normally running in the embodiment [2]. A block diagram in case AP13_R is mutually equal is shown.

  That is, the control air pressure CP11 from the foot brake valve 11 is connected to the brake valve (secondary) port 21_1 and the brake valve (primary) port of the trailer control valve 21 from the output port 15_3 via one input port 15_1 of the double check valve 15. When applied to 21_2 at the same time, air pressure AP12 from the tractor-side air tank 12 has already been applied to the air tank port 21_4 and the trailer-side brake section 32 is in an operable state, as described with reference to FIG. The signal pressure SP corresponding to the control air pressure CP13 is output from 21_5, and the relay valve 33 receiving the signal pressure SP supplies the trailer side brake unit 32 with the air pressure of the trailer side air tank 31 as an operating pressure. Generate braking force on the side.

  At this time, the other input port 15_2 of the double check valve 15 is connected to the pressure adjusting valve 14, but the output port 14_8 of the pressure adjusting valve 14 is connected to the atmosphere opening port 14_9, so that atmospheric pressure is input. It is in a state. Accordingly, the double check valve 15 automatically selects and outputs the control air pressure CP11 from the foot brake valve 11.

  Although not shown, the braking force due to the foot brake operation naturally occurs on the tractor 2 side.

  Fig. 2 (2) shows a case where the tractor 2 and trailer 3 are in a rollover danger state during turning, etc., and a large pressure difference is generated between the air pressure AP13_L and the air pressure AP13_R as in the above embodiment [1]. The block diagram in the case of being is shown.

  That is, the maximum air pressure MAX_AP of the tractor-side air tank 12 is input to the pressure adjustment valve 14 through the input port 14_2C, and the air pressures AP13_L and AP13_R are input through the input ports 14_2L and 14_2R, respectively. When the elastic force of the elastic bodies 14_4L and 14_4R is not balanced by the pressure difference between AP13_L and air pressure AP13_R, the spool valve 14_5 moves to the left by the moving distance L so as to open the outlet 14_3L. The pressure MAX_AP is discharged from the outlet 14_3L.

  At this time, the spool valve 14_11, which has received the maximum air pressure MAX_AP from the input port 14_7 of the output pressure chamber 14_6 via the exhaust port 14_3L, moves to the right against the elastic force of the elastic body 14_10. 14_9 is closed, and the input port 14_7 and the output port 14_8 are made to communicate with each other. As a result, the pressure adjusting valve 14 outputs the maximum air pressure MAX_AP from the output port 14_8 to the double check valve 15.

  Accordingly, the maximum air pressure MAX_AP is simultaneously applied to the brake valve (secondary) port 21_1 and the brake valve (primary) port 21_2 of the trailer control valve 21 via the double check valve 15. At this time, the air pressure (maximum air pressure) AP12 from the tractor-side air tank 12 has already been applied to the air tank port 21_4, and the trailer-side brake part 32 is in an operable state, so the maximum air pressure from the trailer service port 21_5 The signal pressure SP corresponding to MAX_AP is output, and the relay valve 33 receiving it supplies the air pressure of the trailer side air tank 31 as the operating pressure to the trailer side brake part 32, so that only the trailer 3 (rear wheel) side is supplied. Generates the maximum braking force.

  At this time, the input port 15_1 of the double check valve 15 is connected to the foot brake valve 11, but since the maximum air pressure MAX_AP is given from the pressure adjustment valve 14, the foot brake is operated simultaneously. However, the control air pressure CP11 from the foot brake valve 11 is invalidated, and the maximum air pressure MAX_AP from the pressure adjustment valve 14 is automatically selected and output.

  In this way, when a rollover danger state is detected, it is possible to generate a braking force only on the trailer 3 (rear wheel) side. As a result, since the tractor 2 and the trailer 3 are decelerated and go straight, the vehicle can avoid the jackknife phenomenon.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that various modifications can be made by those skilled in the art based on the description of the scope of claims.

It is the block diagram which showed the principle of operation of the pressure control valve used for the brake device of the vehicle which concerns on this invention. 1 is a block diagram showing an embodiment [1] of the overall configuration of a vehicle brake device according to the present invention. FIG. FIG. 3 is a block diagram showing a part of the configuration according to the embodiment [1] of the present invention. FIG. 3 is a block diagram showing an embodiment [2] of the overall configuration of the vehicle brake device according to the present invention. It is the figure which showed the structure and operation | movement of the trailer control valve used for the brake device of the vehicle which concerns on this invention. FIG. 5 is a block diagram showing a part of the configuration according to an embodiment [2] of the present invention.

Explanation of symbols

1 Vehicle
1_1 Vehicle frame
1_2 Rear axle
1_3 Rear wheel
1_3L Left rear wheel
1_3R right rear wheel
1_4, 1_4L, 1_4R Operating arm
11 Foot brake valve
12 Air tank, Tractor side air tank
13, 13_L, 13_R Vehicle height position detector
14 Pressure adjustment valve
14_1 Input pressure chamber
14_2, 14_2L, 14_2C, 14_2R, 14_7 input port
14_3, 14_3L, 14_3R outlet
14_4, 14_4L, 14_4R, 14_10 elastic body
14_5, 14_11 Spool valve
14_6 Output pressure chamber
14_8 output port
14_9 Air opening
14_12 Room wall
15 Double check valve
15_1, 15_2 input port
15_3 output port
16 Brake part
2 Tractor
21 Trailer control valve
21_1 Brake valve (secondary) port
21_2 Brake valve (primary) port
21_3 Parking valve port
21_4 Air tank port
21_5 Trailer service port
21_6 trailer emergency port
3 Trailer
31 Trailer side air tank
32 Trailer side brake
33 Relay valve
AP12 Air pressure
AP13, AP13_L, AP13_R Air pressure
CP11 Control air pressure
L Travel distance
MAX_AP Maximum air pressure
OP working pressure
SP signal pressure In the figure, the same reference numerals indicate the same or corresponding parts.

Claims (4)

A foot brake actuator,
An air tank,
A vehicle height position of the vehicle frame with respect to each of the left rear wheel and the right rear wheel installed on the vehicle frame is detected, and a first air pressure and a second air pressure respectively corresponding to the detected vehicle height position are output. A vehicle height position detection unit;
When the predetermined air pressure of the air tank is input and the first air pressure and the second air pressure are input, and the pressure difference between the first air pressure and the second air pressure exceeds a predetermined threshold, A pressure adjustment valve that outputs a predetermined air pressure;
A normal check air pressure output from the footbrake operating portion as it is, and a double check valve that switches to forcibly output the predetermined air pressure when the predetermined air pressure is received from the pressure adjustment valve;
A brake part connected to the double check valve, for receiving the control air pressure or the predetermined air pressure as an operating pressure and applying a corresponding braking force to the rear wheel;
A brake device for a vehicle comprising: In a vehicle brake device composed of a tractor and a trailer,
A foot brake actuating part on the tractor side,
The air tank on the tractor side,
An air tank on the trailer side,
The brake part on the trailer side,
A vehicle height position of the tractor frame that is installed on the frame of the tractor to detect each of the left rear wheel and the right rear wheel is detected, and a first air pressure and a second air pressure respectively corresponding to the detected vehicle height positions are detected. A vehicle height position detector to output,
When the predetermined air pressure of the tractor-side air tank is input and the first air pressure and the second air pressure are input, and the pressure difference between the first air pressure and the second air pressure exceeds a predetermined threshold A pressure adjusting valve for outputting the predetermined air pressure;
A normal check air pressure output from the footbrake operating portion as it is, and a double check valve that switches to forcibly output the predetermined air pressure when the predetermined air pressure is received from the pressure adjustment valve;
A trailer control valve that is connected to the tractor-side air tank and the double check valve and that outputs the control air pressure output from the double check valve or the air pressure of the tractor-side air tank in response to the predetermined air pressure;
The trailer-side air tank, the trailer-side brake unit, and the trailer control valve are disposed, and when the air pressure output from the trailer control valve is received as a signal pressure, the air pressure of the trailer-side air tank is A relay valve that generates brake force by supplying operating pressure to the brake side,
A vehicle brake device characterized by comprising: In claim 1 or 2,
The pressure regulating valve is
First and second elasticity having the same elastic modulus fixed to the input port for inputting the predetermined air pressure, the first air pressure, and the second air pressure, the two discharge ports, and the wall surfaces on both sides, respectively. When the body and the first air pressure and the second air pressure are equal to each other, the discharge force is closed by the elasticity of the first and second elastic bodies being balanced, and the first air pressure and the second air pressure are When the pressure difference with the second air pressure exceeds the threshold value, the elastic force is not balanced and the first spool moves so as to open the discharge port and discharge the predetermined air pressure from the discharge port. An input chamber having a valve;
An input port communicating with the discharge port, an output port, an air opening port, a third elastic body fixed to the wall surface of the room, and normally, the input port is closed by the elastic force of the third elastic body. When the predetermined air pressure is received from the input port through the exhaust port, the open port to the atmosphere is opened against the elastic force of the third elastic body. And an output pressure chamber having a second spool valve that moves so as to close and close the predetermined air pressure from the output port;
A brake device for a vehicle comprising: In claim 3,
The threshold value corresponds to a movement distance required to move the first spool valve from the normal position to a position where at least one of the discharge ports is changed from the closed state to the open state by the pressure difference. A brake device for a vehicle.

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