JPH10119741A - Method of controlling brake system for vehicle mounted with retarder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retarder brake system control method actuating a retarder control switch interlockingly with the operation of a brake valve and obtaining braking force following the operation of the brake valve in a method of controlling a brake system for a vehicle mounted with a retarder. SOLUTION: A brake valve 11 and a retarder control switch are interlocked with each other. The brake valve 11 for controlling the braking force of a service brake 15 and a retarder R by a brake pedal 7, and a relay valve with differential pressure 33 are provided in parallel. When the brake pedal 7 is depressed, air pressure reduced to the set pressure corresponding to specifications in relation to instructed pressure from the brake valve 11 is supplied to an air master 16, and when the brake pedal 7 is put back, air pressure on the input side of the air master 16 is reduced following the operation of the brake pedal 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electromagnetic retarder,
The present invention relates to a control method of a brake system for a vehicle equipped with a retarder, including a brake means for generating a braking force, such as a fluid type retarder.

[0002]

2. Description of the Related Art As is well known, for example, an electromagnetic retarder, a fluid type retarder, or the like is used as a retarder of a vehicle equipped with a conventional retarder, and ON / OFF of the retarder and adjustment of a braking force are as follows. The decision is made by the driver. FIGS. 7 and 8 show the hydraulic retarder of the above vehicle equipped with a retarder.
The retarder is an auxiliary brake that can be used continuously on a continuous downhill or a highway.

That is, as shown in FIGS. 7 and 8, a retarder R is connected to an engine E and a transmission M connected to the axle 1. An air suspension tank R7 is connected to the retarder R via an air valve R5. By switching the retarder control switch R14 in the driver's seat, a signal output from the retarder control switch R14 is input, and the return of the retarder R is performed. A signal is input from a temperature sensor R11 for detecting the temperature of the cooling water on the side, and a retarder controller R9 for adjusting the opening of the air valve R5 is provided.

The fluid type retarder R is formed, for example, as shown in detail in FIG. 8, and its operation will be described. That is, when the hand lever HR of the retarder control switch R14 in the driver's seat is selected from the switching positions 1 to 4 as shown by arrows in FIG. 7, the air valve R5 is activated, and the output of the four stages is different. Of compressed air to the retarder body.

The hydraulic oil is filled from the oil tank T into the retarder R by the pressure, and the operation of the retarder R is started. At this time, the air inside the retarder R is
It is formed so as to be able to exit quickly from 19. When adjusting the braking force of the retarder R, if the operation oil is filled in the retarder R, the braking torque increases only as the rotation speed increases.

[0006] Therefore, air pressure is adjusted by electronic control to change the filling rate of the above-mentioned hydraulic oil to maintain a stable torque.
The optimum braking ability can be exhibited. When the retarder R is turned off, the hydraulic oil returns to the oil tank T promptly. At this time, the inside of the retarder R is filled with air,
The above-mentioned air also generates a vortex as in the case of the hydraulic oil, and generates an idling torque (about 1/1000 of the case where the hydraulic oil is full).

The idling loss is reduced by using the stator pin R13, though not shown in detail. That is, if there is no hydraulic oil, as shown in FIG. 8, the head of the stator pin R13 protrudes to reduce the vortex of air, and when hydraulic oil enters, it is pushed out of the flow path by the pressure, and Has no effect.

A return cooling water pipe R from the retarder R
A temperature sensor R11 mounted on the monitor 17 monitors the temperature of the cooling water and sends a signal to the retarder control unit R9 so that the temperature of the cooling water determined by the operation of the temperature sensor R11 is not exceeded. .
If the temperature of the cooling water returning to the retarder R becomes equal to or higher than the preset temperature T1 as shown in FIG. 8 (B), the adjusted air pressure decreases linearly, and the position of the hand lever HR of the control switch R14 changes. A certain highest step (position 4 in FIG. 7)
In the case of (stage), the temperature is adjusted in the range of 8 ° C.

The braking force decreases until the amount of heat generated by the braking force and the amount of heat radiated from the cooling system of the vehicle are balanced. This function is called down regulation. If the cooling water temperature exceeds the down regulation range of 8 ° C., the braking force is completely lost, and no heat is generated to protect the cooling system of the vehicle.

The operation of the retarder R is performed by the hand lever H of the retarder control switch R14 shown in FIG.
The braking force can be adjusted in four steps by R, so that a braking force suitable for the running situation can be obtained. Also, the retarder main switch R15 shown in FIG.
Is set to ON during normal running, and when the driver operates the retarder control switch R14 from OFF to the position 1, a retarder indicator lamp (not shown) is turned on and the retarder R is activated.

Further, the retarder control switch R1
The hand lever HR of No. 4 is designed to obtain a higher braking force as the number increases in positions 2, 3, and 4. For example, under the condition of continuous use on a continuous downhill or an expressway, the driver's The magnitude of the braking force of the retarder R is selected from the positions 1 to 4 according to the required braking force.

To release the retarder R, the hand lever HR of the retarder control switch R14 is turned off.

[0013]

However, since the ON / OFF of the conventional retarder R and the adjustment of the braking force are left to the driver's judgment, the conditions of use and the frequency of use are limited. That is, the hand lever HR of the retarder control switch R14 of the conventional retarder R is used.
And the brake pedal are not interlocked, so that the operation for braking the brake pedal and the operation of the retarder control switch R14 must be performed separately to operate the retarder R.
Is formed so as not to operate.

For example, the driver must operate the hand lever HR of the retarder control switch R14 as necessary to select the above-described four-stage braking force of the retarder R. For the driver, extra operation is required during traveling. It is a burden. Further, in the normal service brake by the brake petal 7, relative matching between the service brake 15 and the retarder R is difficult to be performed effectively, particularly when the brake pedal 7 is used continuously on a long continuous downhill or a highway. Therefore, there is a possibility that the wear of the brake lining may be accelerated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is configured so that the operation of a retarder control switch and the operation of a brake pedal are interlocked to operate a retarder, and the amount of braking force generated by the operation of the retarder is reduced. Provided is a method of controlling a brake system for a retarder-equipped vehicle that can reduce the braking force of a service brake by only depressing a brake pedal and control the output of a retarder with respect to the amount of depression of a brake pedal. With the goal.

[0016]

According to the first aspect of the present invention, there is provided a method of controlling a brake system for a vehicle equipped with a retarder, comprising: controlling a braking force of a service brake and a retarder type auxiliary brake by a brake pedal; A relay valve with a differential pressure connected from the air tank to the supply port, a bypass passage that bypasses the relay valve with the differential pressure, and a bypass valve that opens and closes the bypass passage, between the valve and the air master of the service brake, In the method of controlling a brake system for a vehicle equipped with a retarder, the service brake is actuated only for a short time when the brake pedal is depressed, and then the relay valve with differential pressure is controlled by increasing the depression amount of the brake pedal to thereby control the air master. Air pressure on the input side of the valve according to the specifications of the relay valve with differential pressure The bypass pressure is controlled to a predetermined pressure equal to or lower than a set pressure, and when the auxiliary bouquet is operated and a braking force is applied, the bypass valve is turned on, and the air pressure from the brake valve is set as an instruction pressure and the differential pressure is set. The air pressure on the input side of the air master is reduced when the brake pedal is returned by supplying the air pressure reduced by a value corresponding to the specification to the indicated pressure. It is characterized in that the pressure is increased and decreased following the operation of the brake valve.

According to a second aspect of the present invention, there is provided a method of controlling a brake system for a vehicle equipped with a retarder according to the first aspect, wherein the relay valve with differential pressure comprises a supply port connected to the air tank, and the supply port. A valve body having a discharge port connected to the air master for discharging air pressure from the air master, an exhaust port for discharging air pressure supplied to the discharge port, and an input port for receiving a command pressure from the brake valve; An inlet valve provided in the valve body so as to open and close the communication path between the supply port and the discharge port and to urge the communication path in the closing direction, and opens and closes the communication path by the instruction pressure. A piston that is urged in the opening direction and that is capable of closing the exhaust port when air pressure is input from the brake valve and that is provided in the valve body. It is characterized by comprising a.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a first embodiment of the present invention, and is an explanatory diagram showing a configuration of a control system of a brake system for a vehicle equipped with a retarder, and FIG. 2 is an explanatory diagram showing a state of the relay valve with differential pressure in FIG. FIG. 3 is an explanatory view showing a stable state of the differential pressure-added relay valve of FIG. 2, FIG. 4 is an explanatory view showing a released state of the differential pressure-added relay valve of FIG. 2, and FIG.
FIG. 6 is a flowchart showing the operation of the brake control of FIG. 1, and FIG. 6 is a flowchart showing the operation of the retarder control of FIG.
(A) is a map showing the extremely low speed determination hysteresis used in step B4, (b) is a map showing the brake pressure / retarder output used in step B5, and (c) is a retarder output based on the cooling water temperature used in step B6. It is a map showing the degree of squeezing.

A control method of a brake system for a vehicle equipped with a retarder according to an embodiment of the present invention will be described with reference to FIG. 1. The brake device on the front side Fr and the brake device on the rear side Re have substantially the same configuration. Front side Fr
Will be described. Further, the same parts as those in the above-mentioned conventional example are denoted by the same reference numerals and described.

The brake valve 11 for controlling the brake system for a vehicle equipped with a retarder shown in FIG.
0 is connected to the input port 33a of the differential pressure-added relay valve 33, and the output port 33b of the differential pressure-added relay valve 33 can be connected to the air master 16 of the service brake 15 via the position 20A of the bypass valve 20. ing.

The air master 16 is connected to a main brake device 17 provided on the wheel 1a. or,
The pressure sensor 14 is attached to the air passage 30, and a bypass passage 31 that bypasses the relay valve 33 with differential pressure is provided.
Is connected to the downstream side of the pressure sensor 14, and the other end can be connected to the air master 16 via the bypass valve 20.

Also, as shown in FIG.
4. The bypass valve 20 is connected to the control unit 9, and the control unit 9 is electrically connected to the retarder R as the auxiliary brake 10.
The brake valve 11 is configured to change the degree of opening according to the amount of depression of the brake pedal 7, and to supply the air pressure from the inside of the air tank 12 to the air passage 30.

In the case of the present embodiment of a multi-stage embodiment in which a signal based on the magnitude of the air pressure from the pressure sensor 14 provided in the air passage 30 is input to the controller unit 9 and controlled, and the retarder R outputs the signal. The four-stage braking force is converted into an output signal and input to the air valve R5. In addition, the output signal of the braking force in four stages may be input to the control unit 9 as the output signal in a stepless manner, so that the output of the retarder R can be controlled in a stepless manner.

The air valve R5 is configured such that the magnitude of the valve opening is changed in accordance with the magnitude of the output signal from the control unit 9, and the magnitude of the braking force by the retarder R is determined. Next, the operation of the relay valve 33 with differential pressure will be described with reference to FIGS.
When the air pressure (instruction pressure) from the brake valve 11 shown in FIG.
The lower end 41a of 1 moves downward, sits on the upper surface of the C chamber of the inlet valve 43, and closes the exhaust passage 39a.

Further, the inlet valve 43 is pushed down while the springs 45a and 45b are pushed and contracted by the piston 41, and the air supply valve seat 51 of the valve body 50 is opened as shown in FIG. Therefore, the air pressure in the chamber B communicating with the supply port 35 flows into the chamber A communicating with the discharge port 37 via the air supply valve seat 51, and the bypass valve 20 shown in FIG.
Is supplied to the air master 16 via the.

When the command pressure from the brake valve 11 is maintained at a constant pressure, the air pressure flowing from the discharge port 37 to the air master 16 as described above also depends on the command pressure as shown in FIG. And stable. That is, as shown in FIG. 3, the air pressure in the chamber A passes through the air passage 40 and acts on the lower surface of the piston 41, and the lower end 41a of the piston 41 and the upper surface of the inlet valve 43 are kept in close contact with each other from the position in FIG. It is pushed up to the position of FIG.

When the inlet valve 43 comes into contact with the air supply valve seat 51 of the valve body 50 as shown in FIG. 3, the supply port 35 is closed, the supply of air pressure from the air tank 12 stops, and the air flows into the air master 16. The air pressure stabilizes according to the command pressure. Next, when the brake pressure is released, as shown in FIG. 4, when the brake pedal 7 is returned and the command pressure from the brake valve 11 to the input port 33a decreases, the piston 41 is moved to the springs 45a and 45b and the discharge port 37. Pushed up by the air pressure in the chamber A on the side, the exhaust valve seat 52 at the lower end 41a of the piston 41 is separated from the upper surface of the inlet valve 43, and the exhaust passage 39a is opened.

Accordingly, as shown in FIG. 4, the air pressure in the air chamber A of the discharge port 37 is exhausted from the exhaust port 39 to the atmosphere through the central exhaust passages 39a and C. Further, as shown in FIG. 1, one end of the supply port 35 of the relay valve 33 with differential pressure is provided.
And an air passage 33c having the other end connected to the air tank 12 for braking.

The differential pressure-added relay valve 33 opens when the air pressure at the input port 33a shown in FIG. 1 becomes higher than the air pressure at the output port 33b. Supply air pressure to Further, the air master 16 drives the main brake device 17 in accordance with the air pressure supplied from the air tank 12 via the relay valve 33 with differential pressure to apply a braking force to the wheels 1a.

The pressure sensor 14 detects the air pressure (primary air pressure) P ₁ in the air passage 30, outputs a corresponding pressure signal (brake signal), and inputs the pressure signal to the control unit 9. Further, the bypass valve 20 is formed by a three-way solenoid valve, and is controlled to be switched by the control unit 9. When the solenoid 20s is deenergized, it is switched to the position 20A by the spring force of the return spring 20d, and the solenoid 20s is attached. When energized, it is switched to position 20B.

The bypass valve 20 is located at the position 2
When it is switched to 0A, the output port 33b of the differential pressure-added relay valve 33 is closed and the bypass passage 31 is opened to communicate with the air master 16. When it is switched to the position 20B, the output port 33b of the differential pressure-added relay valve 33 and the air master 16 are connected. And the bypass passage 31 is closed.

A pressure sensor 21 is provided in an air passage 32 connecting the discharge port of the bypass valve 20 and the input port 16a of the air master 16. The pressure sensor 21 detects an air pressure (secondary air pressure) P ₂ supplied to the air master 16 and applies a corresponding pressure signal to the control unit 9. In the embodiment of the present invention, as described above, the air pressure (instruction pressure) from the brake valve 11 flows through the air passage 30 according to the depression amount of the brake pedal 7 as shown in FIG. The pressure is supplied to the input port 33a of the relay valve 33 with differential pressure, and the piston 41 is lowered against the urging force of the springs 45a and 45b.

Then, as shown in FIG.
When the lower end 41a of the first member 41 comes into contact with the upper surface of the inlet valve 43, the piston 41 and the inlet valve 43 are integrally lowered against the urging force of the springs 45a and 45b.
The air supply valve seat 51 between the supply port 35 and the discharge port 37 is opened, and the air pressure supplied from the air tank 12 to the supply port 35 is reduced to flow to the discharge port 37 as shown by the arrow. I have.

For example, if the air pressure from the brake valve 11 to the input port 33a of the relay valve 33 with differential pressure is 2 kg / cm ² , the opening of the air supply valve seat 51 of the relay valve 33 with differential pressure will cause 0 air pressure .5kg / cm ² under reduced pressure by 1.5 kg / cm ² is supplied to the Eamasuta 16 from the discharge port 37. This 1.5 kg / cm ² is the same as the brake pressure of a standard vehicle in which the control method of the brake system for a vehicle with a retarder of the present invention is not adopted.

The reduced pressure difference of 0.5 kg / cm ² is determined by setting the spring constants of the springs 45a and 45b. Therefore, the air supply valve seat 52 is opened by taking a differential pressure with respect to the reduced air pressure,
Alternatively, as shown in FIG. 4, the air supply valve seat 51a is opened so that the air pressure in the air passage 32 on the input side of the air master 16 can be discharged to the exhaust passage 39a.

That is, the piston 41 is lowered to overcome the springs 45a and 45b, and the air supply valve seat 51 is opened.
The structure is such that the reduced air pressure can be supplied from the supply port 35 to the discharge port 37 from the air tank 12 through the air passage 33c. As described above, the piston 41 descends to open the supply valve seat 51 of the inlet valve 43, and the air pressure coming from the air tank 12 is adjusted by the degree of opening of the air supply valve seat 51, that is, the spring constant of the springs 45a and 45b. Can be changed by setting.

The air pressure from the air tank 12 is always maintained at a substantially constant pressure (about 9 kg / cm ² ). For example, when the pressure is supplied from the brake valve 11 at 2 kg / cm ² (indicated pressure), the discharge port 37 has a pressure of 0.5 kg / cm ^2.
The pressure is reduced to m ² and an air pressure of 1.5 kg / cm ² is supplied to the air master 16.

Then, 0.5 k of the reduced pressure difference is applied.
g / cm ² by weakening the service brake,
The braking force is compensated by the braking force of the retarder R. In addition, from the stable state shown in FIG. 3, when the command pressure from the brake valve 11 decreases, the piston 41 rises and the contact between the lower end 41a of the piston 41 and the upper end of the inlet valve 43 is released. As shown in FIG. 4, when the piston 41 rises, the air pressure at the discharge port 37 is changed from the discharge port 39 to the atmosphere via the exhaust passage 39a and the C chamber through the gap 52a between the air supply valve seat 52 and the valve body 50. Is discharged.

The relay valve 33 with differential pressure according to the embodiment of the present invention is provided between the air supply port 35 and the exhaust port 39.
It is formed so that it can be opened and closed when a slight differential pressure occurs. Therefore, the differential pressure relay valve 33 adjusts the air pressure on the inlet side of the air master 16 according to the amount of depression of the brake pedal 7 when the amount of depression of the brake pedal changes and the indicated pressure rises and falls. Can be.

Next, the operation of the front brake control will be described with reference to the flowchart shown in FIG. The brake control on the front side determines in step A1 whether an error has occurred in each part of the brake control (not shown). If the determination result is affirmative (YES), the brake control is not performed. Returning to step A1, if no error has occurred in each of the brake control parts, if the answer to the question in step A1 is negative (NO), it is determined in step A2 whether the retarder R is operating. When the answer is (NO), the routine returns without performing the brake control in the same manner as described above, and it is determined that the retarder R is being controlled. When the answer is (YES), the cooling water temperature is determined in step A3. It is determined whether or not is a high temperature.

Since the retarder R is formed so that the brake control is not performed when the coolant temperature is high, the brake control is performed in the same manner as described above when it is determined in step A3 that the coolant temperature is high. Not
If it is determined that the temperature is low, the process proceeds to the next step A4, where it is determined whether or not the brake is abrupt. Then, since the brake control is not performed at the time of sudden braking, it is determined that the sudden braking is performed at step A4,
When the answer is affirmative (YES), the brake control is not performed in the same manner as described above, and when the brake is not abrupt, the answer is negative (NO), and it is determined in step A5 whether the brake pressure change amount is large. Is determined.

Next, in step A5, the magnitude of the change in brake pressure, that is, the magnitude of the change in brake pressure from the brake pressure sensor 14 is determined. If the amount of depression of the brake pedal 7 is small, the bypass is performed in step A6. Valve 20
Turn ON. At this time, as described above with reference to FIG. 2, the air pressure from the brake valve 11 is input to the input port 33a of the relay valve 33 with differential pressure as the above-mentioned instruction pressure, the air supply valve seat 51 is opened, and the air tank 12 is opened. Air pressure
The air supply valve seat 51 is depressurized (for example, 0.
5 kg / cm ² ) and supply the air to the air master 16 via the discharge port 37.

If the determination in step A5 is that the depression amount is large (fast), that is, if the brake pressure change amount is large, the torque of the retarder R immediately rises according to the depression speed of the brake pedal 7. Therefore, the air pressure of the normal service brake is applied first, and when the braking force of the retarder R rises, the bypass valve 20 is turned on to apply the air pressure of the differential pressure to the air master 16. Have been.

When it is determined in step A5 that the amount of change in brake pressure is large, a time set according to the specification is set in a timer in step A7. Next, in step A8, it is determined whether or not the bypass valve 20 may be turned on. If the determination result is affirmative (YES), it is determined that the retarder braking is possible, and in step A6, the bypass valve 20 is turned on. If it is set to ON and the torque of the retarder R has not risen, the answer to the determination is negative (NO), and if the bypass valve 20 is OFF, step A
In step 9, it is determined whether or not the set time set by the timer in step A7 has elapsed. If the set time has elapsed, the determination result is affirmative (YES), and step A6 is performed.
To turn on the bypass valve 20.

If the set time has not elapsed, the answer to the determination in step A9 is negative (NO), and in step A10, the bypass valve 20 is turned off so that the service brake is actuated. To recycle. That is, the normal service brake is applied until the braking force by the retarder R rises as described above.

Further, after the bypass valve 20 is turned on in step A6, the time set in accordance with the specification in step A11 is set by a timer, and it is determined whether or not the set time set in the timer in step A12 has elapsed. If the set time has not elapsed, the answer is negative (NO), the routine returns, the brake control is performed, and if the answer is affirmative (YES), the bypass valve 20 is turned on. Has elapsed, it is determined in step A13 whether or not there is a braking output of the retarder R.

Regarding the determination of the presence or absence of the braking output of the retarder R, the control force of the retarder R in the above-mentioned brake control is to judge immediately before stopping, that is, the braking output of the retarder R is If not, it is determined that the vehicle is in a state immediately before stopping. This is because, when it is determined that the answer at step A13 is negative (NO), the bypass valve 20 is turned off at step A14 to stop the operation of the auxiliary brake 10, and the answer at step A13 is affirmative. When it is determined to be (YES), the control returns and the brake control of the retarder is performed, and the air master 1 follows the operation of the depression amount by the depression and return operations of the brake pedal 7.
The air pressure P ₂ of 6 to the input port 16a of the can slightly adjust.

Next, the retarder control will be described with reference to the flowchart of FIG. In the front side brake control, in step B1, it is determined whether or not each part of the retarder control (not shown) has an error. If the determination result is affirmative (YES), the retarder control is not performed. To return. If no error has occurred in each of the brake control parts, the answer to the question of step B1 is negative (N
In the case of O), the process proceeds to step B2, where the brake pressure is set to 0.
It is determined whether it is larger than 2 kg / cm ² and step B
If the answer to the question 2 is that the brake pressure is less than 0.2 kg / cm ² , it is determined that the braking force of the retarder R is not in a state where the braking is possible, and the routine returns without performing the brake control. When it is determined that the braking force is .2 kg / cm, it is determined that the braking force of the retarder R is in a brakeable state.

Next, at step B3, it is determined whether or not the ABS (anti-skid brake) is operating. If the answer is affirmative (YES), braking of the retarder R is performed during the ABS operation. Since the brake is not formed, the brake braking is not performed, and if the answer to the determination is negative (NO), it is determined that the braking force of the retarder R is in a brakeable state.

Then, in step B4, it is determined whether the vehicle speed is extremely low or not. According to the extremely low speed determination listeristic characteristic of the map shown in FIG. In the same manner as above, the routine returns without performing the brake braking. When the vehicle speed is about 10 km / h or more, it is determined that the vehicle is not at a low speed, the determination result is negative (NO), and the braking force of the retarder R is reduced. It is determined that the state is possible.

Further, in step B5, FIG.
The retarder output according to the brake pressure, that is, the retarder braking force, is calculated using the brake pressure-retarder output map shown in FIG. Next, in step B6, the retarder M is determined by the characteristic of reducing the retarder output based on the cooling water temperature shown in FIG.
The AX output is calculated, and the process proceeds to step B7.
The retarder output calculated in 6 and 7 is compared with the retarder MAX output, and in step B8, the lower retarder output is output as the retarder output, and the control of the retarder is terminated.

[0052] Therefore, since there is provided the differential pressure relay valve 33, following the depression amount of operation by depressing and returning operations of the brake pedal 7, fine adjustment of the air pressure P ₂ of the input port 16a of Eamasuta 16 It can be performed.
In the above-described embodiment, a three-way solenoid valve is used as the bypass valve 20. However, the present invention is not limited to this. Although not shown, for example, as described in JP-A-6-1220 as a conventional example, For example, an electromagnetic valve or the like that simply opens and closes the bypass passage may be used.

Therefore, in the embodiment of the present invention, only the bypass valve 20 is electrically controlled,
By replacing the differential pressure valve for ON / OFF control, which is not shown, for example, in JP-A-6-1220 as a conventional example, with the mechanically operated relay valve 33 with differential pressure, the conventional valve is used. The exhaust valve and the control unit for controlling the exhaust valve can be omitted.

[0054]

As described above in detail, according to the control method of the brake system for a vehicle equipped with a retarder according to the present invention, the braking force of the service brake and the retarder type auxiliary brake is controlled by the brake pedal. A relay valve with a differential pressure connected from the air tank to the supply port, a bypass passage that bypasses the relay valve with the differential pressure, and a bypass valve that opens and closes the bypass passage, between the brake valve and the air master of the service brake. In the control method of the brake system for a retarder-equipped vehicle, the service brake is operated only for a short time when the brake pedal is depressed, and thereafter, the relay valve with differential pressure is controlled with an increase in the depression amount of the brake pedal. Adjust the air pressure on the input side of the air master according to the specifications of the relay valve with differential pressure. The bypass pressure is controlled to a predetermined pressure equal to or lower than a set pressure, and when the auxiliary bouquet is operated and a braking force is applied, the bypass valve is turned on, and the air pressure from the brake valve is set as an instruction pressure and the differential pressure is set. The air pressure on the input side of the air master is reduced when the brake pedal is returned by supplying the air pressure reduced by a value corresponding to the specification to the indicated pressure. Since the pressure is increased / decreased following the operation of the brake valve, the retarder is turned on when the brake pedal is depressed, and the bypass valve is turned off and the normal service brake is activated until the braking force of the retarder reaches the indicated value. When the retarder brake reaches the indicated value, the bypass valve is turned on to reduce the service brake braking force, It is possible to adjust the braking force of the retarder according to the depression amount of over key.

Further, since the retarder is controlled in conjunction with the operation of the brake pedal, the burden on the driver is reduced, and the frequency of using the retarder is increased, so that the life of the brake lining can be extended.
Further, the air pressure at the input port of the air master can be finely adjusted by following the operation of the depression amount by the depression and return operations of the brake pedal.

Therefore, in the present invention, only the above-mentioned bypass valve is electrically controlled, and by using a mechanically operated relay valve with a differential pressure, the exhaust valve and the exhaust valve which are conventionally used are controlled. According to the method of controlling the brake system for a vehicle equipped with a retarder according to the present invention, the method according to the present invention,
The relay valve with differential pressure includes a supply port connected to the air tank, a discharge port that discharges air pressure from the supply port, a discharge port connected to the air master, and an exhaust port that discharges the air pressure supplied to the discharge port. A valve body having an opening and an input port for receiving an instruction pressure from the brake valve; and a valve for opening and closing a communication path between the supply port and the discharge port and for urging the communication path in a closing direction. An inlet valve provided in the main body, the communication path can be opened and closed by the indicated pressure and the communication path can be urged in the opening direction, and the exhaust port can be closed when air pressure is input from the brake valve. And the piston provided in the valve body, the air pressure supplied from the discharge port to the air master can be exhausted with high responsiveness from the exhaust port.

Therefore, it is possible to finely adjust the air pressure at the input port of the air master following the operation of the amount of depression by the operation of depressing and returning the brake pedal.

[Brief description of the drawings]

FIG. 1 illustrates an embodiment of the present invention, and is an explanatory diagram illustrating a configuration of a control system of a brake system for a vehicle equipped with a retarder.

FIG. 2 is an explanatory diagram showing a state when the relay valve with differential pressure in FIG. 1 is operated.

FIG. 3 is an explanatory diagram showing a state when the relay valve with differential pressure in FIG. 2 is stable.

FIG. 4 is an explanatory diagram showing a state when the relay valve with differential pressure in FIG. 2 is released.

FIG. 5 is a flowchart showing the operation of the brake control of FIG. 1;

6 is a flowchart showing the operation of the retarder control of FIG. 1, wherein (a) is a map showing an extremely low speed determination hysteresis used in step B4, and (b) is a brake pressure / retarder output used in step B5. A map showing
(C) is a map used in step B6 and showing the degree to which the retarder output is reduced by the cooling water temperature.

FIG. 7 is an explanatory diagram showing the configuration of a conventional vehicle brake system equipped with a retarder.

FIG. 8 is an explanatory diagram showing a configuration of the retarder of FIG. 7,
(A) is an operation explanatory diagram showing the operation of the retarder, and (B) is a down regulation characteristic diagram showing a relationship between the cooling water temperature and the braking torque of the retarder of FIG. 8 (A).

[Explanation of symbols]

 Reference Signs List 1 axle 7 brake pedal 9 control unit 10 auxiliary brake 11 brake valve 12 air tank 14 brake pressure sensor 15 service brake 16 air master 20 bypass valve 21 air master pressure sensor 30 air passage 31 bypass passage 33 differential pressure relay valve R retarder R5 air valve R7 air suspension Tank R11 Cooling water temperature sensor R19 Ventilation pipe

Claims (2)

[Claims] A brake valve controls a braking force of a service brake and a retarder type auxiliary brake by a brake pedal. A relay valve with a differential pressure connected to a supply port from an air tank is provided between a brake valve and an air master of the service brake. A method of controlling a brake system for a vehicle equipped with a retarder, comprising: a bypass passage that bypasses the relay valve with differential pressure; and a bypass valve that opens and closes the bypass passage, wherein the service brake is operated only for a short time when the brake pedal is depressed. Then, as the depression amount of the brake pedal increases, the relay valve with differential pressure is controlled to adjust the air pressure on the input side of the air master to a predetermined pressure equal to or less than a set pressure set according to the specification of the relay valve with differential pressure. Pressure, and when the auxiliary bouquet operates and braking force is applied, the The bypass valve is switched ON, the air pressure from the brake valve is input as an instruction pressure to the relay valve with differential pressure, and the air pressure reduced by a value according to the specification from the instruction pressure is supplied to the air master. Control of the brake system for a vehicle equipped with a retarder, wherein when the brake pedal is returned, the air pressure on the input side of the air master is increased or decreased following the operation of the brake valve. Method. 2. The relay valve with differential pressure, comprising a supply port connected to the air tank, an air pressure discharged from the supply port, a discharge port connected to the air master, and an air supplied to the discharge port. A valve body having an exhaust port for exhausting pressure, an input port for receiving an instruction pressure from the brake valve, and a communication path between the supply port and the discharge port are opened and closed, and the communication path is urged in a closing direction. When the air pressure is input from the brake valve while opening and closing the communication path by the indicated pressure and urging the communication path in the opening direction as described above, the inlet valve provided in the valve body is provided. A piston provided on the valve body and formed so as to be able to close the exhaust port,
A method for controlling a brake system for a vehicle equipped with a retarder according to claim 1.