JP2007038867A - Brake device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a stop distance of a vehicle without a delay in brake response during an emergency brake operation.
A brake chamber is connected in communication with a main air tank via a drive air passage. A relay valve 16 provided in the drive air circuit has a signal pressure chamber connected to the main air tank via a signal air passage 14, and this relay valve has a pressure of compressed air supplied to and discharged from the signal pressure chamber. Compressed air with a corresponding pressure is supplied to and discharged from the brake chamber. Also, a brake valve 18 for supplying and discharging compressed air with a pressure corresponding to the amount of depression of the brake pedal 17 to the signal pressure chamber is provided in the signal air passage, and one end is connected to the signal air passage near the brake chamber and has a short length. An auxiliary air tank 21 is connected in communication with the other end of the auxiliary air passage 19. Further, a double check valve 31 is provided at the connection portion of the auxiliary air passage to the signal air passage, and the controller 26 controls the electromagnetic valve 22 provided in the auxiliary air passage based on the detection output of the depression amount sensor 24.
[Selection] Figure 1

Description

  The present invention relates to a brake device that brakes a wheel or releases a brake of a wheel by supplying and discharging compressed air to and from a brake chamber of a vehicle such as a bus or a truck according to a depression amount of a brake pedal.

Conventionally, as this type of device, a brake actuator for braking a wheel or releasing the braking of the wheel is connected to an air tank via a driving air passage, and connected to the air tank via a first signal air passage. A relay valve is provided in the drive air passage for supplying and discharging compressed air having a pressure corresponding to the pressure of compressed air supplied to and discharged from the control chamber to the brake actuator, and a brake pedal is connected to the brake actuator. An electrically controlled air brake system (see, for example, Patent Document 1) in which a brake valve for supplying and discharging compressed air having a pressure corresponding to the amount of pedal depression to a control chamber is provided in a first signal air passage is disclosed. In this electrically controlled air brake system, a normally open control signal pressure leakage prevention valve comprising an electromagnetic valve is provided in the first signal air passage that connects the brake valve and the control chamber of the relay valve, and this control signal pressure leakage prevention is provided. In parallel with the valve, a one-way valve is provided that allows only the flow of compressed air from the upstream side to the downstream side when the pressure difference between the upstream side and the downstream side of the control signal pressure leakage prevention valve is equal to or greater than a predetermined pressure. A second signal air passage connecting the control chamber of the relay valve and the air tank is provided with a normally closed control signal pressure supply valve made up of an electromagnetic valve, and one end of the third signal air passage connected to the control chamber. A normally closed control signal pressure discharge valve comprising an electromagnetic valve for discharging the control signal pressure of the control chamber is provided at the end. A drive air circuit in which a first pressure sensor for detecting the pressure of the first signal air passage is provided in the first signal air passage between the brake valve and the control signal leakage prevention valve, and the relay valve and the brake actuator are connected in communication. A second pressure sensor for detecting the pressure of the drive air circuit is provided, and a normally open pedal switch that is turned on when the brake pedal is depressed is provided on the brake pedal. Further, the electronic control unit is configured to control the control signal pressure leakage prevention valve, the control signal pressure supply valve, and the control signal pressure discharge valve based on the detection outputs of the first pressure sensor, the second pressure sensor, and the pedal switch, respectively. The
In the electric control air brake system configured as described above, when the brake pedal is depressed, the electronic control device quickly closes the control signal pressure leakage valve, so that the control signal pressure on the output side of the brake valve increases rapidly. The control signal pressure is detected by the first pressure sensor with little delay, and the electronic control unit controls the control signal pressure based on the electrical signal of the control signal pressure and the electrical signal of the brake pressure of the brake actuator detected by the second pressure sensor. The pressure supply valve and the control signal pressure discharge valve are controlled to open and close. As a result, the brake can be operated with almost no delay in response, and good response can be obtained.
JP 11-43040 A (Claim 1, paragraph [0019])

However, in the electric control air brake system disclosed in Patent Document 1 above, the electronic control device closes the control signal pressure leakage valve based on the detection output of the pedal switch, so that the control signal pressure on the output side of the brake valve is reduced. However, if the first signal air passage from the brake valve to the control signal pressure leakage valve is long, it takes time for the pressure in the first signal air passage to reach a predetermined pressure, and the vehicle is stopped urgently. For this reason, there is a risk that a response delay of the brake may occur during an emergency brake operation in which the brake pedal is depressed deeply and deeply.
In the electric control air brake system disclosed in the above-mentioned conventional patent document 1, the electronic control device opens and closes the control signal pressure supply valve and the control signal pressure discharge valve based on the detection outputs of the first and second pressure sensors. However, if the second signal air passage connecting the control chamber of the relay valve and the air tank is long, it takes time for the pressure in the second signal air passage to reach a predetermined pressure. There was a risk of response delay.
Furthermore, since the electric control air brake system disclosed in the above-mentioned conventional patent document 1 requires the first and second pressure sensors in addition to the pedal switch, the control circuit becomes complicated and is already manufactured and practically used. However, it is difficult to incorporate an electrically controlled air brake system into a vehicle used for the vehicle.
An object of the present invention is to provide a vehicle brake device that can prevent a response delay of a brake during an emergency brake operation and can shorten a stop distance of the vehicle.
Another object of the present invention is to provide a brake device for a vehicle that can be configured with a relatively simple control circuit and can be incorporated into a vehicle that has already been manufactured and put into practical use.

In the invention according to claim 1, as shown in FIG. 1, a brake chamber 11 for braking a wheel or releasing a wheel brake is connected to a main air tank 13 through a drive air passage 12, and a signal is sent to the main air tank 13. A relay valve 16 that has a signal pressure chamber connected in communication via an air passage 14 and supplies / discharges compressed air having a pressure corresponding to the pressure of compressed air supplied / discharged to / from the signal pressure chamber is driven. A vehicle is provided with a brake valve 18 provided in the air passage 12 and connected to the brake pedal 17 and supplying and discharging compressed air having a pressure corresponding to the amount of depression of the brake pedal 17 to and from the signal pressure chamber. It is an improvement of the brake device.
The characteristic configuration is that one end of the auxiliary air passage 19 is connected to the signal air passage 14 between the brake valve 18 and the relay valve 16 and the other end of the auxiliary air passage 19 is connected to the other end. Provided to the brake chamber 11 is a compressed air having a high pressure among the compressed air from the brake valve 18 and the compressed air from the auxiliary air tank 21 that is provided in the air tank 21 and the connecting portion of the auxiliary air passage 19 to the signal air passage 14. The double check valve 31 is provided in the auxiliary air passage 19 so as to communicate with the auxiliary air tank 21 and the double check valve 31, or the auxiliary air tank 21 and the drive air passage 12 are blocked and the double check valve 31 is communicated with the atmosphere. When the brake pedal 17 is quasi-steadily depressed, the maximum pressure of compressed air is set to the signal pressure. A depression amount sensor 24 for detecting that reaches the depression amount supplied to, there is to provided with a controller 26 for controlling the solenoid valve 22 based on the detection output of the depression amount sensor 24.

  In the vehicle brake device according to the first aspect, when the driver depresses the brake pedal 17 strongly and deeply in order to stop the vehicle urgently, the amount of depression of the brake pedal 17 is reduced to the signal pressure. The depression amount sensor 24 detects that the depression amount to be supplied to the room has been reached. At this time, when the controller 26 controls the electromagnetic valve 22 to communicate between the auxiliary air tank 21 and the double check valve 31 based on the detection output of the depression amount sensor 24, the compressed air from the auxiliary air tank 21 is compressed from the compressed air from the brake valve 18. Since the pressure is higher, the double check valve 84 shuts off the brake valve 18 and the signal pressure chamber of the relay valve, and communicates the auxiliary air tank 21 and the signal pressure chamber of the relay valve 16. As a result, the compressed air in the auxiliary air tank 21 is instantaneously supplied to the signal pressure chamber of the relay valve 16, so that the compressed air in the main air tank 13 quickly passes through the drive air passage 12 and the relay valve 16 to the brake chamber 11. Supplied. On the other hand, when the driver releases the depression of the brake pedal 17 to restart the vehicle, the depression amount of the brake pedal 17 is less than the depression amount for supplying the compressed air with the maximum pressure to the signal pressure chamber. The sensor 24 detects it. At this time, the controller 26 controls the electromagnetic valve 22 based on the detection output of the depression amount sensor 24 to shut off the auxiliary air tank 21 and the double check valve 31 and communicates the double check valve 31 to the atmosphere. Compressed air in the signal pressure chamber is discharged from the electromagnetic valve 22 to the atmosphere. Thereby, the compressed air in the brake chamber 11 is discharged from the relay valve 16 to the atmosphere. “Quasi-steady” in “when the brake pedal 17 is depressed quasi-steadily” means “gradually”, specifically, the compressed air in the main air tank or the auxiliary air tank It means that the propagation speed of pressure is so slow that it can be ignored.

The invention according to claim 3 is the invention according to claim 1, and further, as shown in FIG. 1, the capacity of the auxiliary air tank 21 is 1 to 2 liters.
In the vehicle brake device described in claim 3, even if the capacity of the auxiliary air tank 21 is reduced to 1 to 2 liters, the compressed air in the auxiliary air tank 21 is supplied to the signal pressure chamber of the relay valve 16 having a small volume. Because it is only done, there is no shortage of capacity.
The invention according to claim 4 is the invention according to claim 1, and further, as shown in FIG. 1, in order to make the pressure in the main air tank 13 and the pressure in the auxiliary air tank 21 the same, It is further characterized by further comprising a same pressure air passage 27 for connecting the air tank 21 in communication.
In the vehicle brake device according to the fourth aspect, since the main air tank 13 and the auxiliary air tank 21 are connected to each other by the same pressure air passage 27, not only the main air tank 13 but also the driver normally operates the brake pedal 17. The compressed air in the auxiliary air tank 21 can be supplied to the brake chamber 11 through the relay valve 16.

  As described above, according to the present invention, one end of the short auxiliary air passage is connected to the signal air passage between the brake valve and the relay valve, and the auxiliary air tank is connected to the other end of the auxiliary air passage. In addition, a double check valve is provided in the communication connection portion of the auxiliary air passage to the signal air passage, an electromagnetic valve is provided in the auxiliary air passage, and the controller controls the electromagnetic valve based on the detection output of the depression amount sensor. When the depressing amount sensor detects that the depressing amount of the brake pedal has reached the depressing amount for supplying the compressed air with the maximum pressure to the signal pressure chamber, the controller controls the electromagnetic valve to communicate between the auxiliary air tank and the double check valve. . As a result, the compressed air from the auxiliary air tank has a higher pressure than the compressed air from the brake valve, so the double check valve shuts off the brake valve and the signal pressure chamber of the relay valve, and the signal pressure of the auxiliary air tank and the relay valve. Communicate with the room. As a result, the compressed air in the auxiliary air tank is instantaneously supplied to the signal pressure chamber of the relay valve through the relatively short auxiliary air passage without being discharged from the brake valve, so that the compressed air in the main air tank is driven. The air is supplied to the brake chamber quickly through the air passage and the relay valve. As a result, it is possible to prevent a delay in the response of the brake during an emergency brake operation, thereby shortening the stop distance of the vehicle. Further, since the first and second pressure sensors are required in addition to the pedal switch, the control circuit becomes complicated, and the conventional electric control air brake system that is difficult to be incorporated into a vehicle that has already been manufactured and put into practical use In comparison, the present invention can be configured with a relatively simple control circuit and can be incorporated into a vehicle that has already been manufactured and is in practical use.

Even if the capacity of the auxiliary air tank is reduced to 1 to 2 liters, the compressed air in the auxiliary air tank is only supplied to the signal pressure chamber of the relay valve having a small capacity, so that the capacity does not become insufficient. As a result, there is little space for installing the auxiliary air tank.
Furthermore, if the main air tank and the auxiliary air tank are connected to each other via the same pressure air passage in order to make the pressure in the main air tank and the auxiliary air tank equal, if only the main air tank is used during normal operation of the brake pedal by the driver, The compressed air of the auxiliary air tank can be supplied to the brake chamber through the relay valve. As a result, the capacity of the main air tank can be reduced.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
As shown in FIG. 1, a brake device for a vehicle is connected to a brake chamber 11 for braking or releasing a wheel by supplying and discharging compressed air, and the brake chamber 11 through a drive air line 12. A main air tank 13 in which compressed air is stored, a relay valve 16 having a signal pressure chamber connected to the main air tank 13 via a signal air line 14 and provided in the drive air line 12; A brake valve 18 mechanically connected to the brake pedal 17 and provided in the signal air line 14. The brake chamber 11 is configured such that the chamber plunger 11a protrudes and retracts from the chamber case 11b by the supply and discharge of compressed air and the elastic force of a built-in spring (not shown). Although not shown in the figure, the brake shoe provided in the wheel of the wheel is configured to be brought into pressure contact with the brake drum or to be detached from the brake drum due to the appearance of the chamber plunger 11a.

  On the other hand, the relay valve 16 includes a first port 16a connected to the driving air conduit 12 on the main air tank 13 side, a second port 16b connected to the driving air conduit 12 on the brake chamber 11 side, and a signal pressure chamber. And a signal port 16c connected to the signal air pipe 14 and an exhaust port 16d opened to the atmosphere. The base end of the brake pedal 17 is pivotally mounted on the upper surface of the brake valve 18 so that compressed air having a pressure corresponding to the depression amount of the brake pedal 17 is supplied to and discharged from the signal pressure chamber. Further, the relay valve 16 supplies / discharges compressed air having a pressure corresponding to the pressure of compressed air supplied / discharged to / from the signal pressure chamber to the brake chamber 11, that is, based on the signal pressure from the brake valve 18, It is comprised so that the compressed air in 13 may be supplied and discharged. Specifically, when the air pressure in the signal pressure chamber gradually increases, compressed air having a pressure proportional to the air pressure is supplied from the main air tank 13 to the brake chamber 11 through the first port 16a and the second port 16b. When the air pressure in the signal pressure chamber gradually decreases, the compressed air in the brake chamber 11 is supplied to the second port 16b and the exhaust port so that the air pressure in the brake chamber 11 becomes a pressure proportional to the air pressure in the signal pressure chamber. It is configured to be discharged into the atmosphere through 16d.

  On the other hand, one end of a short auxiliary air line 19 is connected in communication with the signal air line 14 between the brake valve 18 and the signal pressure chamber of the relay valve 16 in the vicinity of the relay valve 16. An auxiliary air tank 21 is connected in communication with the other end of the auxiliary air line 19. A double check valve 31 is provided at the connecting portion of the auxiliary air passage 19 to the signal air passage 14, and an electromagnetic valve 22 is provided in the auxiliary air passage 19. The double check valve 31 includes a check case 31a and a check piston 31b slidably accommodated in the case 31a. The case 31 a includes a first check port 31 c connected to the brake valve 18, a second check port 31 d connected to the first solenoid valve port 22 a of the solenoid valve 22, and a signal from the relay valve 16. A check third port 31e connected to the pressure chamber is provided. The double check valve 31 is configured to supply high-pressure compressed air from the compressed air from the brake valve 18 and the compressed air from the auxiliary air tank 21 to the signal pressure chamber of the relay valve 16. That is, when the air pressure from the brake valve 18 is higher than the air pressure from the auxiliary air tank 21, the check piston 31b moves to the check second port 31d side, and the check first port 31c and the check third port. When the port 31e communicates and the air pressure from the brake valve 18 is lower than the air pressure from the auxiliary air tank 21, the check piston 31b moves to the check first port 31c side and the check second port 31d. And the third port 31e for checking are configured to communicate with each other.

  The electromagnetic valve 22 is a three-port two-position switching electromagnetic valve. The electromagnetic valve 22 is connected to the auxiliary air tank 21 and connected to the check second port 31d of the double check valve 31. It has the 2nd port 22b for valves, and the exhaust port 22c for solenoid valves open | released by air | atmosphere. When the auxiliary solenoid valve 22 is operated, the first solenoid valve port 22a and the second solenoid valve port 22b communicate with each other to communicate between the auxiliary air tank 21 and the double check valve 31, and the double check valve 31 from the atmosphere. When the auxiliary solenoid valve 22 is shut off and the solenoid side solenoid valve 22 is deactivated, the solenoid valve second port 22b and the solenoid valve exhaust port 22c communicate with each other to shut off the auxiliary air tank 21 and the double check valve 31, and It is configured to communicate with the atmosphere. Here, the length of the auxiliary air line 19 is set to 0.5 to 2 m, preferably 0.5 to 1 m, and the length of the signal air line 14 from the double check valve 31 to the signal pressure chamber of the relay valve 16 is set. Is set to 0.5 to 2 m, preferably 0.5 to 1 m, and the length of the drive air pipe 12 from the relay valve 16 to the brake chamber 11 is set to 1 to 3 m, preferably 1 to 2 m. . The reason that the length of the auxiliary air pipe 19 is limited to the range of 0.5 to 2 m is that the auxiliary air tank 21 cannot be connected to the signal air pipe 14 if the length is less than 0.5 m, and if the length exceeds 2 m, the inside of the auxiliary air tank 21 This is because the time until the compressed air is supplied to the signal pressure chamber of the relay valve 16 becomes longer. In addition, the length of the signal air line 14 from the double check valve 31 to the signal pressure chamber of the relay valve 16 is limited to the range of 0.5 to 2 m. This is because it cannot be connected to the pipe line 14 and if it exceeds 2 m, the time until the compressed air in the auxiliary air tank 21 is supplied to the signal pressure chamber of the relay valve 16 becomes longer. Furthermore, the length of the drive air line 12 from the relay valve 16 to the brake chamber 11 is limited to a range of 1 to 3 m. If the length is less than 1 m, the drive air line 12 cannot be connected to the brake chamber 11 and 3 m This is because if it exceeds, the time until the compressed air in the main air tank 13 is supplied to the brake chamber 11 becomes longer.

  On the other hand, a depression amount sensor 24 is provided for detecting that the depression amount for supplying the compressed air having the maximum pressure (the same pressure as that in the main air tank 13) to the signal pressure chamber when the brake pedal 17 is depressed quasi-steadily. It is done. Specifically, a depression amount sensor 24 that detects that the depression amount of the brake pedal 17 is 70% or more of the full stroke of the brake pedal 17 is provided. Here, the amount of depression of the brake pedal 17 is limited to a range of 70% or more of the full stroke of the brake pedal 17 because the maximum pressure (same as that in the main air tank 13) when the brake pedal is depressed quasi-steadily. This is because the amount of depression of the compressed air supplied to the signal pressure chamber of the relay valve 16 reaches 70% of the full stroke. In this embodiment, the depression amount sensor 24 is a limit switch, and is configured such that the sensor plunger 24a protrudes and retracts from the sensor case 24b by the elastic force of a built-in spring (not shown). The detection output of the stepping amount sensor 24 is connected to the control input of the controller 26, and the control output of the controller 26 is connected to the electromagnetic valve 22. Further, in order to make the pressure in the main air tank 13 and the pressure in the auxiliary air tank 21 the same, the main air tank 13 and the auxiliary air tank 21 are connected in communication by the same-pressure air line 27. The capacity of the auxiliary air tank 21 is set to 1 to 2 liters, preferably 1.5 to 2 liters. Here, the capacity of the auxiliary air tank 21 is limited to the range of 1 to 2 liters. If less than 1 liter, a sufficient amount of compressed air cannot be supplied to the signal pressure chamber of the relay valve. This is because the amount of storage of the vehicle becomes excessive, and more vehicle space must be secured. In addition, the code | symbol 29 in FIG. 1 is a module of an anti-lock brake system (ABS).

The operation of the thus configured vehicle brake device will be described.
When the driver depresses the brake pedal 17 strongly and deeply in order to stop the vehicle urgently, the depressing amount is reached that the maximum pressure of compressed air is supplied to the signal pressure chamber when the brake pedal 17 is quasi-steadily depressed. The amount sensor 24 detects that the amount of depression of the brake pedal 17 is 70% or more of the full stroke of the brake pedal 17. At this time, the controller 26 controls the electromagnetic valve 22 based on the detection output of the depression amount sensor 24 so as to communicate between the auxiliary air tank 21 and the double check valve 31 and to block the double check valve 31 from the atmosphere. As a result, the pressure of the compressed air from the auxiliary air tank 21 becomes higher than that of the compressed air from the brake valve 18, so that the check piston 31b of the double check valve 31 moves to the check first port 31c side to check The second port 31d and the check third port 31e communicate with each other. As a result, the brake valve 18 and the signal pressure chamber of the relay valve 16 are shut off, and the auxiliary air tank 21 and the signal pressure chamber of the relay valve 16 communicate with each other, so that the compressed air in the auxiliary air tank 21 Without being discharged from the exhaust port 16 d, it is instantaneously supplied to the signal pressure chamber of the relay valve 16 through the relatively short auxiliary air line 19 and the signal air line 14. Accordingly, the first and second ports 16a and 16b of the relay valve 16 communicate with each other, and the compressed air in the main air tank 13 is promptly supplied to the brake chamber 11 through the drive air line 12 and the relay valve 16. Brake response delay during emergency brake operation can be prevented, and the stopping distance of the vehicle can be shortened.

  When the driver releases the depression of the brake pedal 17 in order to restart the vehicle, the depression amount of the brake pedal 17 is a depression that supplies the compressed air of the maximum pressure to the signal pressure chamber when the brake pedal 17 is quasi-steady depression. The depression amount sensor 24 detects that the depression amount is less than the amount, that is, the depression amount sensor 24 detects that the depression amount of the brake pedal 17 is less than 70% of the full stroke of the brake pedal 17. At this time, the controller 26 controls the electromagnetic valve 22 based on the detection output of the depression amount sensor 24 to shut off the auxiliary air tank 21 and the double check valve 31 and communicate the double check valve 31 to the atmosphere. As a result, the compressed air in the brake chamber 11 is discharged from the relay valve 16 to the atmosphere, and the compressed air in the brake chamber 11 is discharged to the atmosphere from the exhaust port 16d of the relay valve 16 through the driving air conduit 12. The brake is released immediately.

  On the other hand, when the driver steps on the brake pedal 17 gently and relatively shallowly to stop the vehicle gradually, the amount of depression of the brake pedal 17 is less than 70% of the full stroke of the brake pedal 17. The state detected by the sensor 24 is maintained. Therefore, the controller 26 controls the electromagnetic valve 22 based on the detection output of the stepping amount sensor 24 to shut off the auxiliary air tank 21 and the double check valve 31, and keep the double check valve 31 in communication with the atmosphere. As a result, the pressure of the compressed air from the auxiliary air tank 21 becomes higher than the pressure of the compressed air from the brake valve 18, so that the check piston 31b of the double check valve 31 moves to the check second port 31d side to check. The first port 31c and the check third port 31e communicate with each other. As a result, the auxiliary air tank 21 and the double check valve 31 are shut off, and the brake valve 18 and the double check valve 31 communicate with each other, so that the compressed air in the main air tank 13 and the same pressure air line 27 in the auxiliary air tank 21 are connected. After the compressed air passing through is adjusted to a pressure corresponding to the depression amount of the brake pedal 17 by the relay valve 16, it is supplied to the brake chamber 11 through the driving air pipe 12, and the vehicle is gradually decelerated and stopped.

  When the driver depresses the brake pedal 17 further and the depressing amount sensor 24 detects that the depressing amount of the brake pedal 17 is 70% or more of the full stroke of the brake pedal 17, the controller 26 depresses the depressing amount sensor 24. Based on the detected output, the electromagnetic valve 22 is controlled to communicate between the auxiliary air tank 21 and the double check valve 31, and the double check valve 31 is shut off from the atmosphere. At this time, since the pressure of the compressed air from the brake valve 18 and the pressure of the compressed air from the auxiliary air tank 21 are substantially the same, the check piston 31b of the double check valve 31 is moved to the check second port 31d side. The first port 31c for checking and the third port 31e for checking are kept in communication with each other. As a result, the auxiliary air tank 21 and the double check valve 31 are kept in a disconnected state, and the brake valve 18 and the double check valve 31 are kept in communication, so that the compressed air in the main air tank 13 and the auxiliary air tank 21 Compressed air passing through the same pressure air pipe 27 is supplied to the brake chamber 11 through the relay valve 16 and the driving air pipe 12 without being reduced in pressure by the relay valve 16, and is supplied to the brake chamber 11. The braking force is further increased. In this state, when the driver releases the depression of the brake pedal 17 to restart the vehicle, the depression amount sensor 24 indicates that the depression amount of the brake pedal 17 is less than 70% of the full stroke of the brake pedal 17. To detect. At this time, the controller 26 controls the electromagnetic valve 22 based on the detection output of the depression amount sensor 24 to shut off the auxiliary air tank 21 and the double check valve 31, and the check second port 31d of the double check valve 31 is set to the atmosphere. Communicate. However, since the check piston 31b is positioned on the check second port 31d side, the compressed air in the signal pressure chamber of the relay valve 16 passes through the check third port 31e and the check first port 31c to the brake valve. 18 exhaust ports 18a. As a result, the compressed air in the brake chamber 11 passes through the drive air conduit 12 and is discharged from the exhaust port 16d of the relay valve 16 to the atmosphere, so that the brake is released quickly.

Next, examples of the present invention will be described in detail together with comparative examples.
<Example 1>
The brake device of the present invention was mounted on a truck loaded with 15 tons of luggage on the loading platform. This track was referred to as Example 1. Specifically, as shown in FIG. 1, one end of the auxiliary air pipe 19 having a length of 1 m is connected to the signal air pipe 14 between the brake valve 18 and the relay valve 16. The auxiliary air tank 21 was connected in communication with the other end. In addition, a check valve 31 that is doubled is provided at a communication connection portion of the auxiliary air line 19 to the signal air line 14, a solenoid valve 22 that switches between three ports and two positions is provided in the auxiliary air line 19, and a depression amount sensor 24 is a brake pedal. 17 is configured to detect that the depression amount of the brake pedal 17 is 70% or more of the full stroke of the brake pedal 17. Further, the controller 26 is configured to control the electromagnetic valve 22 based on the detection output of the depression amount sensor 24. Note that the length of the auxiliary air line 19 is set to 1 m, the length of the signal air line 14 from the double check valve 31 to the signal pressure chamber of the relay valve 16 is set to 1 m, and the brake valve is connected to the brake chamber. The length of the drive air duct 12 up to 11 was set to 2 m.
<Comparative Example 1>
A truck having the same configuration as that of Example 1 was used as Comparative Example 1 except that the auxiliary air line, the auxiliary air tank, and the solenoid valve were not used.

<Comparative test 1 and evaluation>
In the state where the truck of Example 1 and Comparative Example 2 is traveling at a speed of 90 km / hour, the deceleration with respect to time when the brake pedal is stepped strongly and deeply to make an emergency stop, and the vehicle speed with respect to the travel distance Changes were measured. The results are shown in FIGS.
As is clear from FIG. 2, it was found that the deceleration in Example 1 was improved over that in Comparative Example 1. Further, as is clear from FIG. 3, it was found that the vehicle speed decreased in Example 1 at a shorter distance than Comparative Example 1.
<Test 2 and evaluation>
In a state where the truck of Example 1 was traveling at a speed of 90 km / hour, a change in pressure in the brake chamber was measured when the brake pedal was strongly and deeply depressed to make an emergency stop. The result is shown in FIG.
As apparent from FIG. 4, when the depression amount of the brake pedal became 50 mm and the depression amount sensor was turned on, the pressure in the brake chamber increased to the maximum pressure almost simultaneously. As a result, it was found that the compressed air in the main air tank passed through and quickly supplied to the brake chamber.

It is a circuit block diagram containing the brake device of the vehicle of embodiment of this invention. It is a figure which shows the change of the deceleration of the vehicle with respect to the time after operating the brake of Example 1 and Comparative Example 1. FIG. It is a figure which shows the change of the vehicle speed with respect to the distance which a vehicle advances after operating the brake of Example 1 and Comparative Example 1. FIG. It is a figure which shows the change of the pressure of the compressed air in a brake chamber with respect to the stroke of the brake pedal of Example 1. FIG.

Explanation of symbols

11 Brake chamber 12 Drive air line (drive air path)
13 Main air tank 14 Signal air line (Signal air passage)
16 Relay valve 17 Brake pedal 18 Brake valve 19 Auxiliary air pipeline (auxiliary air passage)
21 Auxiliary air tank 22 Solenoid valve 24 Depression amount sensor 26 Controller 27 Same pressure air pipe (same pressure air passage)
31 Double check valve

Claims (4)

A brake chamber (11) for braking the wheel or releasing the braking of the wheel is connected to the main air tank (13) through the drive air passage (12), and the signal air passage (14) is connected to the main air tank (13). A relay valve (16) having a signal pressure chamber communicated with each other and supplying and discharging compressed air having a pressure corresponding to the pressure of compressed air supplied to and discharged from the signal pressure chamber to the brake chamber (11) Is provided in the drive air passage (12), connected to the brake pedal (17), and a brake valve (18 for supplying and discharging compressed air having a pressure corresponding to the depression amount of the brake pedal (17) to the signal pressure chamber. ) In the vehicle brake device provided in the signal air passage (14),
A short auxiliary air passage (19) having one end connected to the signal air passage (14) between the brake valve (18) and the relay valve (16);
An auxiliary air tank (21) connected in communication with the other end of the auxiliary air passage (19);
High pressure compression of the compressed air from the brake valve (18) and the compressed air from the auxiliary air tank (21) provided in the communication connection portion of the auxiliary air passage (19) to the signal air passage (14) A double check valve (31) for supplying air to the brake chamber (11);
Provided in the auxiliary air passage (19) to communicate between the auxiliary air tank (21) and the double check valve (31) or to block between the auxiliary air tank (21) and the drive air passage (12) and A solenoid valve (22) for switching the double check valve (31) to communicate with the atmosphere;
A depressing amount sensor (24) for detecting that the depressing amount for supplying the compressed air with the maximum pressure to the signal pressure chamber when the brake pedal (17) is depressed quasi-steadily;
A vehicle brake device comprising: a controller (26) that controls the electromagnetic valve (22) based on a detection output of the depression amount sensor (24).   The length of the auxiliary air passage (19) is 0.5 to 2 m, and the length of the signal air pipe (14) from the double check valve (31) to the signal pressure chamber of the relay valve (16) is 0. The vehicle brake device according to claim 1, wherein the length of the drive air passage (12) from the relay valve (16) to the brake chamber (11) is 1 to 3 m.   The vehicle brake device according to claim 1, wherein the capacity of the auxiliary air tank (21) is 1 to 2 liters.   In order to make the pressure in the main air tank (13) and the pressure in the auxiliary air tank (21) the same, the air pressure passage (27) further connecting the main air tank (13) and the auxiliary air tank (21) is further provided. The vehicle brake device according to claim 1.

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