JPH11124018A - Brake control system having a hill starting aid device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make piping and attachment to the vehicle easier as well as to reduce costs, by reducing the number of parts and thus simplifying as much as possible the ABS and HSA(Hill Start Aid). SOLUTION: When the vehicle is stopped with the ordinary brake by pressing down a brake pedal 1, the HSA ECU closes an ABS holding valve 51, which is always open, of ABS modulators 8, 18, 19 by the wheel velocity detection signal of each wheel velocity sensor 25-28, and the air pressure is maintained by brake actuators 11, 22, 23. As a result, the brake remains on even when the brake pedal 1 is released. Pressing down the accelerator pedal causes the HSA ECU to open an ABS pressure regulator 52, which is always closed, of the ABS modulators 8, 18, 19. As a result, as the brake actuator air is discharged the ABS holding valve 51 is opened and the brake is released. In this way, the HSA is activated using the ABS modulator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-skid brake control system (hereinafter also referred to as "ABS") for adjusting a braking force in order to prevent a braked wheel from being locked during braking, and to idle a driving wheel at the time of starting or sudden acceleration. A traction control system (hereinafter, also referred to as TRC) that adjusts the driving force of the drive wheels by brake control in order to prevent hills, and a hill start assist device (Hill Start) that enables hill start to be easily performed by brake control.
Aid: hereinafter also referred to as HSA) belongs to the technical field of a brake control system including an HSA, and particularly belongs to the technical field of a brake control system in which an ABS modulator performs the function of the HSA.

[0002]

2. Description of the Related Art In recent years, in an automobile brake control system, an anti-skid control modulator (hereinafter referred to as A
An ABS that adjusts the braking force so as to cancel the wheel lock during braking by a BS modulator) and a traction control valve (hereinafter also referred to as a TRC valve) eliminates idling of the driving wheels at the time of starting or sudden acceleration. A brake control system has been developed in which a TRC that adjusts the driving force and an HSA that facilitates starting on a slope by using a slope start assist valve (hereinafter also referred to as an HSA valve) are integrally incorporated.

[0003] Such ABS, TRC and HSA
As an example of a conventional brake control system provided with a brake control system, there is a brake control system disclosed in Japanese Patent Application Laid-Open No. HEI 8-91118.
No. 45334 discloses an HSA valve.

FIG. 9 is a diagram showing a brake control system disclosed in Japanese Patent Application Laid-Open No. Hei 8-91118, and FIG. 10 is an HSA disclosed in Japanese Patent Application Publication No. Hei 6-45334.
It is a figure showing a valve.

In FIGS. 9 and 10, during normal braking,
When the brake pedal 1 is depressed to operate the dual brake valve 2, the compressed air (hereinafter, also referred to as air) in the air tank 3 flows from the dual brake valve 2 to the input port 5 of the HSA valve 4, the open check valve 6. ,
The air is supplied to the brake actuators 11 of the non-driven wheels 9, 10 through the output port 7 and the ABS modulator 8 on the front wheel side, and the air in the air tank 3 'is supplied from the dual brake valve 2 to the input port of the HSA valve 12. 13, an open check valve 14, an output port 15, double check buckles 16 and 17, front and rear wheels (hereinafter, also simply referred to as drive wheels) 20, which are drive wheels through ABS modulators 18 and 19 on the rear wheel side. 21 and the brake actuators 22, 23 of the rear wheels 20 ', 21' which are non-drive wheels, the brake actuators 11, 22, 23 generate brake hydraulic pressure. , 10,20,20 ', 21,21' are introduced into brake cylinders (not shown), and each wheel 9,10,20,20 ',
The brakes 21, 21 'operate.

In order to release braking, the brake pedal 1
Is released to bring the dual brake valve 2 into the non-operating position, the air supplied to the brake actuators 11, 22, and 23 reverses the air supplied to the brake actuators 11, 22, and 19, and the HSA valves 4, and 19, respectively. The air is discharged from the dual brake valve 2 to the atmosphere through the air passage 12.
As a result, the brake actuators 11, 22, and 23 are deactivated, so that the wheels 9, 10, 20, 20 ', 2
The brake of 1,21 'is released.

During braking, the ABS / TRC ECU 24
When it is determined that at least one of the wheels 9, 10, 20, 20 ', 21, 21' has a tendency to lock based on the wheel speeds from the wheel speed sensors 25, 26, 27, 28, Of the ABS modulators 8, 18, and 19, at least an ABS modulator corresponding to a wheel that tends to lock is operated to perform anti-skid control that adjusts the braking force so that the locking tendency is eliminated.

Also, when starting or accelerating, the ABS / TR
The C ECU 24 is provided with the respective wheel speed sensors 2 for the drive wheels 20 and 21.
When it is determined that at least one of the drive wheels 20, 21 has a tendency to idle based on the wheel speeds from the wheels 7, 28, the TRC valve corresponding to the drive wheel among the normally closed TRC valves 29, 30 Control the opening and closing of the air tank 3
Is supplied to the brake actuator via the double check valve and the ABS modulator on the side of the driving wheel that tends to run idle, and the driving force is applied so that the braking of the driving wheel that tends to run idle is applied to eliminate the tendency to spin. Perform traction control to adjust.

Further, the HSA operates as follows.
First, the HSA operation switch 31 is turned on and the parking brake is released. The release of the parking brake is detected by the parking brake switch 32, and the parking brake release signal is output from the HSA ECU 33.
Sent to Next, when the brake pedal 1 is depressed,
Air is output from the dual brake valve 2, and the pressure of the air is detected by the pressure switches 34 and 35.
The brake activation signal from the pressure switches 34 and 35 is HSA
It is supplied to the ECU 33. Further, similarly to the above-described normal brake, air is supplied from the dual brake valve 2 to the brake actuators 11, 22, and 23, and the respective wheels 9,
The brakes at 10, 20, 20 ', 21, 21' operate.

If the brake pedal 1 is continuously depressed for a predetermined time (eg, one second) when the vehicle is stopped, the HSA EC
U33 excites the solenoids 36 of the HSA valves 4 and 12 to activate the armature 37, opening the first on-off valve 38 and closing the second on-off valve 39. As a result, the pressure chambers 40 and 41 communicate with the chamber 46 that constantly communicates with the air tank 3 and are cut off from the atmosphere, so that the air in the air tank 3 is introduced into the pressure chambers 40 and 41. With this air, both control pistons 42 and 43 operate to close both check valves 6 and 14, and as a result, the flow of air from output ports 7 and 15 to input ports 5 and 13 is blocked. HSA valve 4,12
Simultaneously with the excitation of the solenoid 36, the HSA ECU 33 turns on the pilot lamp 44 to notify the driver that the HSA valves 4 and 12 are on. The driver releases the brake pedal 1 after seeing the lighting of the pilot lamp 44. When the brake pedal 1 is released, the brake actuator 1
The air introduced into the brake actuators 1, 2, 23 is blocked by the check valves 6, 14 from flowing toward the dual brake valve 2.
The air is held in 2, 23, and the brake is held in the operating state.

In order to release the brake operation by turning off the HSA valves 4 and 12, for example, the depression of the accelerator pedal is detected and the excitation of the solenoid 36 is released. Thereby, the first on-off valve 38 is closed and the second on-off valve 39 is closed.
Is opened, and the air supplied to the pressure chambers 40 and 41 is
5, the control pistons 42, 43 return to the inactive position, and the check valves 6, 14 open. Therefore, the air introduced into the brake actuators 11, 22, and 23 respectively passes through the check valves 6 and 14 to the atmosphere from the discharge port of the dual brake valve 2 to the atmosphere in the same manner as in the case of the normal brake release described above. Ejected and brake released.

[0012]

In such a conventional brake control system, the ABS modulators 8, 18, 19, the TRC valves 29, 30, and the HSA valves 4, 12 are separately provided. For this reason, not only the number of parts is large, but also their piping is complicated, and it is difficult and troublesome to attach them to a vehicle, resulting in high cost.

In addition, the check valves 6 of the HSA valves 4 and 12
Although the control pistons 42 and 43 for controlling the operation of the piston 14 are formed of stepped pistons, such a structure of the stepped piston requires a large number of seal portions and requires the first and second on-off valves 38 and 39. For this reason, the HSA valves 4 and 12 have to have not only a complicated structure but also a higher cost.

The present invention has been made in view of such circumstances, and has as its object to reduce the number of parts and reduce the AB
An object of the present invention is to provide a brake control system provided with a slope start assist device that can simplify installation of the S and the HSA as much as possible, thereby facilitating attachment to piping and a vehicle and reducing costs.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an invention according to claim 1 includes an air tank for storing compressed air, a brake operation member for performing a brake operation, and a brake operation of the brake operation member. A brake valve that operates and outputs, and a brake actuator that is supplied with air at an output pressure of the brake valve or air at a pressure controlled by controlling the air pressure of the air tank according to the output pressure of the brake valve to generate a brake pressure; It is possible to supply air to the brake actuator by opening the air of the output pressure of the brake valve or the air pressure of the air tank in accordance with the output pressure of the brake valve by opening at normal time and when increasing the pressure of the anti-skid control. At the same time, the anti-skid control is closed and the brake An anti-skid control holding valve for holding the air pressure of the heater, and closing at normal time and at the time of holding and increasing the pressure of the anti-skid control, and opening at the time of reducing the pressure of the anti-skid control to exhaust the air of the brake actuator, An anti-skid control modulator having an anti-skid control pressure reducing valve for reducing the air pressure of the brake actuator, a first pressure detecting means for detecting an output pressure of the brake valve, and detecting an air pressure of the brake actuator Second pressure detecting means;
A wheel speed sensor for detecting a wheel speed of a wheel, an accelerator padal depression detection sensor for detecting depression of an accelerator pedal, and at least one wheel locked based on a wheel speed detection signal from the wheel speed sensor during braking of the wheel. When it is determined that there is a tendency, the anti-skid control holding valve and the anti-skid control pressure-reducing valve are controlled to maintain, reduce, and increase the air pressure of the brake actuator. An anti-skid control device that controls the anti-skid modulator so that the brake operation of the brake operating member is performed, and when the vehicle stops, the anti-skid control holding valve is closed to close the anti-skid control holding valve. By holding the air pressure, the brake In the brake operation holding state, based on the accelerator pedal depression detection signal of the accelerator pedal depression detection sensor, the anti-skid control pressure reducing valve is opened, and the anti-skid control holding valve is opened to open the brake. And a brake operation holding control device for canceling the operation holding state.

The invention of claim 2 comprises a two-brake system having a dual brake valve, and the two-brake system is provided with the anti-skid control modulator and the brake actuator, respectively. And the first
And a second pressure detecting means.

Further, the invention of claim 3 is characterized in that both the first and second pressure detecting means are constituted by pressure sensors. Further, in the invention according to claim 4, the first pressure detecting means is constituted by a pressure switch, and a plurality of predetermined pressures serving as references for adjusting a brake holding pressure in a brake operation holding state are set. It is characterized by.

According to a fifth aspect of the present invention, the first and second pressure detecting means are both constituted by pressure switches, and at least the pressure switch of the second pressure detecting means has an on-pressure and an off-pressure. And has a hysteresis. The invention according to claim 6 is characterized in that the first pressure detecting means is constituted by a pressure switch for a stop lamp.

[0019]

According to the present invention thus constructed, the HSA operation can be easily performed by the ABS modulator of the conventional brake control system having the ABS. At this time, the conventional HSA valve is not required, so that the number of parts is reduced and the piping is simplified. Therefore, even if the brake control system having the ABS has the HSA function, the system configuration is simplified. .

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an example of an embodiment of a brake control system including a slope start assist device according to the present invention. The same components as those in the brake control system shown in FIG. 9 described above are denoted by the same reference numerals, and a detailed description thereof will be omitted.

As shown in FIG. 1, this brake control system includes an air tank 3 in a front wheel side brake system.
Is transmitted through an air passage 47 and a relay valve 49 provided in the air passage 47 to the ABS modulator 8 on the front wheel side.
It is connected to the. In the rear wheel side brake system, the air tank 3 ′ is connected to the air passage 48,
The rear wheel-side ABS modulator 18,
19 is connected. Since the relay valves 49 and 50 have exactly the same structure as each other and are conventional general well-known relay valves and are not directly related to the present invention, their detailed description will be omitted.

The ABS modulators 8, 18, and 19 have exactly the same structure and are conventionally known.
Since this is directly related to the present invention, a brief description will be given. As shown in FIG. 2, these ABS modulators 8, 18, and 19 include an ABS holding valve 51 and an ABS exhaust valve 52. The ABS holding valve 51 is provided with a communication position I and a cutoff position II, and is normally constituted by a normally-open electromagnetic open / close valve set at the communication position I. The ABS exhaust valve 52 is provided with a cutoff position I and a communication position II. And a normally closed solenoid on-off valve normally set at the shut-off position I.

An inlet 51a of the ABS holding valve 51 is connected to the relay valve 49 or the double check valve 17, and an outlet 51b of the ABS holding valve 51.
Are connected to the brake actuators 11, 22, 23. The inlet 52a of the ABS exhaust valve 52 is connected to the brake actuators 11, 22, and 23, and the outlet 52b of the ABS exhaust valve 52 is an exhaust port that opens to the atmosphere.

Further, the ABS holding valve 51 and the ABS exhaust valve 5
Although not shown, each of the solenoids 51c and 52c is connected to the ABS / TRC ECU 24 and to the HSA ECU 33, similarly to the conventional brake control system shown in FIG. In the case of the first example, the ABS / TRC ECU 24 and the HSA
It is connected to the ECU 33 so that data can be exchanged with each other. The ABS / TRC ECU 24
It is needless to say that the HSA ECU 33 and the HSA ECU 33 may be integrally configured as one controller, that is, one controller may perform the ABS control, the TRC control, and the HSA control.

The output side of the brake valve 2 is connected to the command pressure inlet 49a of the relay valve 49 via a passage 53 in the front wheel brake system, and is connected to the relay valve 50 via a passage 54 in the rear wheel brake system. It is connected to the indication pressure inlet 50a. A pressure sensor 55 for detecting the output pressure of the brake valve 2 is provided in a passage 54 of the rear wheel brake system, and a pressure sensor 55 for detecting the output pressure of the brake valve 2 is provided in the passage between the ABS modulator 19 and the brake actuator 23 on the right side of the rear wheel brake system. , ABS modulator 1
9, the output pressure of the brake actuators 11, 22, 2
A pressure sensor 56 for detecting the air pressure of No. 3 is provided. Although not shown, these pressure sensors 55 and 56 are both connected to the HSA ECU 33.

On the other hand, the TR branched from the passage 48 on the rear wheel side
The C passage 57 is connected to another input port of the double check valve 17. The TRC passage 57 has a TR
A C electromagnetic switching valve 58 is provided. This TRC electromagnetic switching valve 58 is a conventionally known one, and its detailed description is omitted, but its solenoid 58d is made of ABS / TRCEC.
The input port 58a and the output port 58b are normally shut off by the ABS / TRC ECU 24 and the output port 58b and the exhaust port 58c are communicated by the ABS / TRC ECU 24, and the input port 58a and the output port are used during traction control. 58b, and the output port 58b and the exhaust port 58
c is cut off and the traction control command pressure is output.

Further, the rear rear wheel 2 which is a non-drive wheel on the rear wheel side
Hydraulic passages 59, 6 connecting brake cylinders 0 ', 21' (not shown) and brake actuators 22, 23
TRC cut valves 61 and 62 in which a communication position I and a shut-off position II are set at 0 are provided. These TRs
Indicating pressure introducing portions 61a, 62a of C cut valves 61, 62
Is the double check valve 1 from the TRC electromagnetic switching valve 58.
7 is connected to the TRC passage 57 on the 7 side, and the communication position is normally set when the command pressure is not introduced through the TRC passage 57.
In addition, when the command pressure is introduced through the TRC passage 57 during traction control, the setting is switched to the cutoff position II.

Further, in the brake control system of the first example, although not shown, an accelerator pedal depression detecting sensor for detecting depression of an accelerator pedal is provided, and the accelerator pedal depression detecting sensor is connected to the HSAE.
It is connected to CU33. And ABS / TRC
The ECU 24 controls each wheel speed sensor 25,
When it is detected based on the wheel speeds from 26, 27, and 28 that the wheel speed has become 0 due to the vehicle stop, the detection signal is output to the HSA ECU 33 and the HSA E
The CU 33 activates each of the ABS holding valves 51 of the ABS modulators 8, 18, and 19 based on the output signal from the ABS / TRC ECU 24 so as to be in the brake operation holding state, and based on the detection signal from the accelerator pedal depression detection sensor. Then, the ABS exhaust valve 52 is set to the communication position II to release the brake operation holding state, and the HSA function of setting the ABS holding valve 51 to the communication position II is performed. At this time, the setting of the ABS holding valve 51 to the communication position II is performed simultaneously with or after the setting of the ABS exhaust valve 52 to the communication position II. In addition,
When the wheel speed becomes 0 due to vehicle stop, HS
Instead of performing the action of A, H
It is also possible to use an SA operation switch.

In this case, the ABS / TRC ECU 24
Are the wheel speed sensors 25, 26, 27,
When it is determined that the wheel speed has become zero due to the wheel lock based on the wheel speed from No. 28, the detection signal of the wheel speed 0 is not output to the HSA ECU 33, and thus the HSA ECU 33 does not output the detection signal.
The ECU 33 does not hold the brake operation, that is, does not perform the HSA operation.

Further, based on the pressure detection signal of the output pressure of the ABS modulator 19 from the pressure sensor 56, the HSA ECU 33 determines that the initial brake holding pressure at the time of the brake holding state is a predetermined pressure (for example, 2 .5kg / cm
² ) If it is determined that the brake holding pressure is larger than the predetermined value, the ABS exhaust valve 52 is controlled to reduce the brake holding pressure to the predetermined pressure, and it is determined that the initial brake holding pressure is equal to or lower than the predetermined pressure. In this case, the brake holding pressure is held as it is.

At the initial brake holding pressure, the stop holding of the vehicle, for example, when the vehicle starts moving on a slope or the like, is insufficient. Therefore, when the driver depresses the brake pedal again,
The HSA ECU 33 detects the additional depression of the brake pedal based on the pressure detection signal of the output pressure of the brake valve 2 from the pressure sensor 55, and when the additional depression is detected, the ABS holding valve 51
To increase the pressure to a pressure corresponding to the output pressure of the brake valve 2. That is, HSA
The ECU 33 stops adjusting the subsequent brake holding pressure to the above-mentioned predetermined pressure when detecting an additional depression of the brake pedal 1. However, when the brake holding pressure is equal to or lower than a predetermined pressure when the brake pedal 1 is further depressed, the HSA ECU 33 sets the ABS modulators 8, 1
Even if the ABS holding valve 51 of 8, 19 is set to the communication position I,
When it is determined based on the pressure detection signal of the pressure sensor 56 that the brake holding pressure does not increase so much, the ABS holding valve 51 is immediately set to the shut-off position II again.

When the ABS exhaust valve 52 is set to the communication position II in order to release the brake operation holding state based on the detection signal from the accelerator pedal depression detection sensor, the HSA ECU 33 detects the pressure from the pressure sensor 56. When it is determined from the signal that the pressure of the brake actuator 23 has decreased to a predetermined pressure (for example, 0), the ABS exhaust valve 52 is set to the shut-off position I and the ABS holding valve 51 is set to the communication position I at the same time. I have.

In the case of the first example, the ABS exhaust valve 52 can be set to the communication position II and the ABS holding valve 51 can be set to the communication position I when the accelerator pedal is depressed. In addition, A at the time of starting this vehicle
The closing control of the BS exhaust valve 61 may be performed when the operation time of the ABS exhaust valve 61 (that is, the time set to open) reaches a predetermined time.

Another configuration of the brake control system of the first example is the same as that of the conventional brake control system shown in FIG.
6, TRC valves 29, 30 and pressure switch 34,
Although not shown in FIG. 1 except that 35 is omitted, it is substantially the same as the configuration of the brake control system in FIG.

The operation of the brake control system of the first example thus configured will be described. When the brake is not operated, the components in the brake control system are as shown in FIG.
And the state shown in FIG. In this state, when the brake pedal 1 is depressed and a brake operation is performed, the brake valve 2 adjusts and outputs the pressure of the air in the air tanks 3 and 3 ′ according to the depression of the brake pedal 1. The air of the output pressure of the brake valve 2 is introduced into the indicated pressure inlets 49a and 50a of the relay valves 49 and 50 via the passages 53 and 54, respectively. Then, the relay valves 49 and 50 adjust and output the pressure of the air in the air tanks 3 and 3 ′ according to the output pressure of the brake valve 2.

The air of the output pressure of the relay valve 49 on the front wheel side is supplied to the brake actuator 11 via the ABS holding valve 51 of the ABS modulator 8. Thus, the brake actuator 11 generates a brake fluid pressure, and the brakes of the front wheels 9 and 10 are operated by the brake fluid pressure.

At the same time, the air at the output pressure of the relay valve 50 on the rear wheel side is supplied to the double check valve 17 and each A
It is supplied to each brake actuator 22, 23 via each ABS holding valve 51 of the BS modulator 18, 19. As a result, the brake actuators 22, 23 generate brake fluid pressure, and the brake fluid pressure causes the rear front wheels (drive wheels) 20, 21; and the rear rear wheels (non-drive wheels) 20 ', 2
Each brake 1 'operates.

To release the braking, the brake pedal 1
Is released to bring the brake valve 2 to the non-operating position, the air introduced into the command pressure introduction ports 49a, 50a of the relay valves 49, 50 is discharged to the atmosphere from the exhaust port 2a of the brake valve 2, respectively. Then, each relay valve 4
9 and 50 are inactive positions, and the air supplied to each of the brake actuators 11, 22, and 23 is A
Each of the relay valves 49 and 5 passes through the BS holding valve 51 (and the double check valve 17 on the rear wheel brake system side).
The exhaust ports 49b, 50b are discharged to the atmosphere. Thereby, the brake actuators 11, 22, 2
Since 3 is in the inactive position, the brakes on each wheel are released.

During braking, if the ABS / TRC ECU 24 determines that at least one wheel has a tendency to lock based on each wheel speed signal from each wheel speed sensor 25, 26, 27, 28, ABS / TRC ECU 24 The TRC ECU 24 controls the ABS of the ABS modulator corresponding to the wheels that tend to lock.
The holding valve 51 is actuated to the shut-off position II. As a result, each of the brake actuators 11, 22, and 23 is cut off from each of the input ports 51a, and the brake is held. However, if the ABS / TRC ECU 24 determines that the locking tendency has not been eliminated yet, the ABS / TRC ECU 24 then operates the ABS exhaust valve 52 to set the communication position II. As a result, the air supplied to the brake actuators 11, 22, and 23 is exhausted from the exhaust port 52b of the ABS exhaust valve 52, and the brake is depressurized.

Thus, the ABS / TRC ECU 24
Determines that the tendency to lock the wheels has been eliminated,
The holding valve 51 and the ABS exhaust valve 52 are set to the inoperative position. Then, the ABS holding valve 51 is at the communication position I, the ABS exhaust valve 52 is at the shutoff position I, and the brake pressure is increased.

The ABS / TRC ECU 24
By repeatedly controlling the operation of the ABS holding valve 51 and the ABS exhaust valve 52 until the tendency to lock the wheels is completely eliminated, the control of pressure reduction, holding or pressure increase with respect to the supply air pressure of the brake actuators 11, 22, and 23 is performed. Is repeatedly performed.

The ABS / TRC ECU 24 determines that at least one of the drive wheels tends to idle when starting or accelerating based on the wheel speeds from the wheel speed sensors 27 and 28 of the drive wheels 20 and 21. When it is determined that the time has been reached, the TRC electromagnetic switching valve 58 is operated. Then, the input port 58a and the output port 58b of the TRC electromagnetic switching valve 58 communicate with each other, and the air in the air tank 3 'flows into the passage 48, the TRC passage 57, the TRC electromagnetic switching valve 58, the passage 57, the double check valve 17, and It is supplied to each brake actuator 22, 23 via the ABS holding valve 51 of the ABS modulator 18, 19. Then, the brake actuators 22 and 23 generate brake fluid pressure in exactly the same manner as in the case of the normal brake described above. At this time, the air in the air tank 3 'is simultaneously released from the TRC electromagnetic switching valve 58 to each TRC cut valve 6
1, 62 are also introduced into the indicated pressure introduction sections 61a, 62a, respectively. Then, each TRC cut valve 61, 62 is set to the shut-off position II, and the brake actuator 22,
23 and the non-driven wheels 20 ', 21' are shut off.

Therefore, each brake actuator 2
2, 23 brake fluid pressures are supplied to the wheel cylinders (not shown) of the respective drive wheels 20, 21 so that the respective drive wheels 20, 21
Of the non-driven wheels 20 ', 21' are not supplied to the wheel cylinders (not shown) of the non-driven wheels 20 ', 21', and the brakes of the non-driven wheels 20 ', 21' are not operated. . Thereby, the driving force of the driving wheels 20, 21 is reduced.

The ABS / TRC ECU 24
The TRC electromagnetic switching valve 58 is repeatedly controlled between non-operation and operation based on the wheel speeds of the drive wheels 20 and 21 to control the braking force of the drive wheels 20 and 21 and eliminate the tendency of the drive wheels to spin. Control the driving force appropriately. In this example, the left and right drive wheels 20, 21
Brake force is controlled at the same time, but TR
C electromagnetic switching valve 58 is provided separately for the left and right driving wheels 2
The braking force of 0,21 can also be independently adjusted according to the degree of the idling tendency of the left and right drive wheels 20,21.

When the ABS / TRC ECU 24 determines that the idling tendency of the drive wheels has been completely eliminated, the ABS / TRC ECU 24 sets the TRC electromagnetic switching valve 58 to the inoperative position. Then, the output port 58
b communicates with the exhaust port 58c, and the air supplied to each of the brake actuators 22 and 23 is supplied to the ABS
The air is exhausted from the exhaust port 58c to the atmosphere via the ABS holding valve 51, the double check valve 17, and the output port 58b of the modulators 18 and 19, and the air from the command pressure introducing portions 61a and 62a of the TRC cut valves 61 and 62 is also reduced. ,
The exhaust gas is discharged from the exhaust port 58c of the TRC electromagnetic switching valve 58 to the atmosphere. Thereby, each brake actuator 22, 2
3, the brake fluid pressure of the drive wheels 20, 21 is released, and the TRC cut valve 61,
62 is set to the communication position I, the brake actuators 22, 23 communicate with the wheel cylinders of the non-driving wheels 20 ', 21', and the brakes of the non-driving wheels 20 ', 21' can be operated. .

Further, the HSA operates as follows.
Now, the vehicle is stopped by the normal brake by depressing the brake pedal 1. When the vehicle stops, the HSA ECU
33 (same as FIG. 9) are wheel speed sensors 25, 26, 27,
When it is determined that the wheel speed has become 0 based on the wheel speed detection signal input from the ABS / TRC ECU 24 through the ABS / TRC ECU 24, the ABS holding valves 51 of all the ABS modulators 8, 18, and 19 are operated and the shut-off position is determined. II. Then, the brake pressures of the brake actuators 11, 22, and 23 are held as in the case of the brake pressure holding in the ABS control described above. At this time, the brake pedal 1 is still depressed, but even if the brake pedal 1 is released at this time, each of the ABS modulators 8, 18, 19
Is set to the shut-off position II, the brake pressure holding state is maintained.

Then, the first brake holding pressure at this time is detected by the pressure sensor 56, and based on the pressure detection signal from the pressure sensor 56, the HSA
If the ECU 33 determines that the initial brake holding pressure is higher than the predetermined pressure, the ECU 33 connects the ABS exhaust valve 52 to the communication position.
Set to II and reduce the initial brake holding pressure to this predetermined pressure. If the HSA ECU 33 determines that the initial brake holding pressure is lower than the predetermined pressure,
The S holding valve 51 and the ABS exhaust valve 52 are both held at the shut-off position.

It is assumed that the driver has depressed the brake pedal 1 more than when the vehicle was stopped in a case where the initial brake holding pressure is considerably lower than the predetermined pressure and the stop holding is not sufficient. The output pressure of the brake valve 2 at this time is detected by the pressure sensor 55, and based on the pressure detection signal from the pressure sensor 55, the HSA EC
U33 determines whether or not the brake pedal 1 has been further depressed. If it is determined that the brake pedal 1 has been depressed further, AB
The S holding valve 51 is set to the communication position I to increase the brake holding pressure. In this case, the HSA ECU 33 stops adjusting the subsequent brake holding pressure to the above-described predetermined pressure, and increases the brake holding pressure to a value larger than the predetermined pressure.

Although not shown, a further warning device is provided in the driver's cab, and when the HSA ECU 33 determines that the initial brake holding pressure is lower than a predetermined pressure, the HSA ECU 33 activates this further warning device to operate the vehicle. It may be made to notify a person of the need for additional steps.

When the vehicle starts, an accelerator pedal depression sensor (not shown) detects depression of the accelerator pedal.
The HSA ECU 33 sets the ABS exhaust valve 52 to the communication position II based on the detection signal from the accelerator pedal depression detection sensor. Then, the air supplied to the brake actuators 11, 22, and 23 is discharged into the atmosphere from the exhaust port 52b of the ABS exhaust valve 52 in the same manner as in the case of the pressure reduction in the ABS control described above, and the brake actuators 11, 22, and 23 are released. Pressure drops. Pressure sensor 5
6, when the pressure of the brake actuators 11, 22, and 23 decreases to a predetermined pressure, the ABS holding valve 51 is moved to the communication position.
When set to I, the ABS exhaust valve 52 is shut off to position II
And the air of the brake actuators 11, 22, and 23 is relayed through the ABS holding valve 51 to the relay valves 49, 5
0 is exhausted from the exhaust ports 49b and 50b. As a result, the brake holding state is released, and the vehicle enters a startable state.

As described above, according to the brake control system of the first example, the HSA operation can be performed without a significant design change using the ABS modulator of the brake control system having the conventional ABS. Become like Therefore, since the conventional HSA valves 4 and 12 can be omitted, the number of parts can be reduced and the piping can be extremely simplified. Thus, even if the brake control system has the HSA function, the configuration of the system can be simplified and the cost can be reduced.

The pressure switch 55 for detecting the output pressure of the brake valve 2 can also be used as the stop lamp pressure switch conventionally used. In this case, when the vehicle starts, the ABS exhaust valve 52 and the ABS holding valve 51 of the ABS modulator may both be opened so that the stop lamp is not turned on at that time.

FIG. 3 is a view similar to FIG. 1 showing a second embodiment of the present invention. The same components as those in the above-described first example are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the first example, the relay valves 49, 5
0, the output pressure of the brake valve 2 is used as the command pressure of these relay valves 49, 50, and the output pressure of the relay valves 49, 50 is used as the ABS modulators 8, 1.
Brake actuators 11, 22, 2 via 8, 19
3, the brake control system according to the second example, as shown in FIG.
Is supplied directly to the brake actuators 11, 22, and 23 via the ABS modulators 8, 18, and 19, and the relay valves 49 and 50 are omitted. Other configurations of the brake control system of the second example are the same as those of the first example.

In the brake control system of the second example configured as described above, the relay valves 49 and 50 are eliminated, so that the number of parts is further reduced and the configuration is further simplified. However, the responsiveness of the brake control system of the first example including the relay valves 49 and 50 is better. Another operation and effect of the brake control system of the second example is as follows.
Same as the example.

FIG. 4 is a view similar to FIG. 1 showing a third embodiment of the present invention. The same components as those in the above-described first example are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the above-described first example, the ABS modulators 8, 18, and 19 and the relay valves 49 and 50 are provided separately. However, in the brake control system of the third example, FIG. As shown in FIG. 7, ABS modulators 8, 18, and 19 with a relay valve in which an ABS modulator and a relay valve are integrated are used. A with relay valve
The BS modulators 8, 18, and 19 are conventionally known, and an example thereof is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-125619. Since the ABS modulators 8, 18, and 19 with relay valves can be understood by referring to this publication, a detailed description thereof will be omitted here.
First, a brief explanation.

In the ABS modulators 8, 18, and 19 having no relay valve in the first and second examples, the air supplied to the brake actuators 11, 22, and 23 is supplied to the ABS holding valve 51 and the ABS exhaust valve during the ABS control. The ABS modulators 8, 18, and 19 with the relay valve control the air at the indicated pressure for operating the relay valve during the ABS control with the ABS holding valve 51 and the ABS.
The control is performed by the S exhaust valve 52. Therefore, the command pressure of the relay valve is controlled by the ABS holding valve 51 and the ABS exhaust valve 52 during the ABS control,
As a result, the output pressure of the relay valve supplied to the brake actuators 11, 22, 23 is controlled.

In the brake control system of the third example,
Since the ABS modulator and the relay valve are integrated, the number of parts is reduced and the configuration of the system is simplified. Other configurations, operation and effects of the brake control system of the third example are the same as those of the first example.

In a vehicle such as an automobile, the output pressure of the brake valve 2 is generally detected by a pressure switch (not shown), and the stop lamp of the vehicle is turned on when the brake is activated. At the time of release, the air of the brake actuators 11, 22, and 23 is discharged from the brake valve 2 through the passages 53 and 54, respectively.
In the third example, when the brake operation is released, the air at the pressure indicated by the ABS modulators 8, 18, and 19 with relay valves is discharged from the brake valve 2 through the passages 53 and 54, respectively. When the ABS exhaust valve 52 is set to the communication position II at the same time when the pedal is depressed and the ABS holding valve 51 is set to the communication position I, the air of the brake actuators 11, 22, 23 and the ABS modulators 8, 18, 19 with the relay valves are set. The air of the indicated pressure is discharged from the brake valve 2 through the passages 53 and 54, respectively, and the stop lamp of the vehicle may be lit by the air pressure. Thus, in these second and third examples, the ABS holding valve 51 is set to the communication position I with a delay after the ABS exhaust valve 52 is set to the communication position II by depressing the accelerator pedal. In this case, as described above, when the pressures of the brake actuators 11, 22, and 23 and the command pressures of the ABS modulators with relay valves 8, 18, and 19 decrease, and the ABS exhaust valve 52 is set to the shut-off position I again. At the same time, it is desirable to set the ABS holding valve 51 to the communication position I.

FIG. 5 is a view similar to FIG. 1 showing a fourth embodiment of the present invention. The same components as those in the above-described first example are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the first example described above, the pressure sensor 55 is used to detect the output pressure of the brake valve 2. However, in the brake control system of the fourth example, as shown in FIG. The pressure switch 63 which operates when the output pressure becomes a predetermined pressure serving as a reference of the brake holding pressure is used. This pressure switch 63
It is connected to CU33.

The pressure switch 63, unlike the pressure sensor, cannot detect the actual value of the output pressure of the brake valve 2. Therefore, in the fourth example, a first predetermined pressure and a second predetermined pressure (first predetermined pressure <second predetermined pressure) are set as predetermined pressures serving as references for the brake holding pressure, respectively. And the second predetermined pressure is HSAE
It is stored in the CU 33.

The first predetermined pressure is set as a reference for the initial brake holding pressure when the vehicle is stopped, and is determined by the HSA ECU.
The controller 33 operates the ABS holding valve 51 to adjust the initial brake holding pressure to the first predetermined pressure when the wheel speed becomes 0 when the vehicle stops. When the brake pedal is further depressed, the HSA ECU 33 operates the ABS holding valve 51 to increase the brake holding pressure to the second predetermined pressure by the ON signal of the pressure switch 63 when the brake pedal is further depressed. Adjust to Note that three or more predetermined pressures serving as a reference for the brake holding pressure can be set as necessary.

In the brake control system of the fourth example,
Since the pressure switch 63, which is cheaper than the pressure sensor, is used, the system can be configured at lower cost. Other configurations, operation and effects of the brake control system of the fourth example are the same as those of the first example.

FIG. 6 is a view similar to FIG. 5 showing a fifth example of the embodiment of the present invention. The same components as those in the above-described fourth example are denoted by the same reference numerals, and a detailed description thereof will be omitted.

In the above-described fourth example, the pressure switch 63 is used only for detecting the output pressure of the brake valve 2. However, in the brake control system of the fifth example, as shown in FIG. The pressure switch 63 is used not only to detect the output pressure of the ABS modulator 19 but also to detect the output pressure of the ABS modulator 19 (that is, the air pressure of the brake actuator 23). . HSA of this pressure switch 64
It is connected to the ECU 33.

In this case, in the fifth example, the predetermined pressure serving as the reference of the brake holding pressure as described above is not set variously. Instead, the ON pressure of the pressure switch 64 for detecting the output pressure of the ABS modulator 19 is set. And the off pressure has a hysteresis.

When the pressure switch 64 is turned on by the initial brake holding pressure, the HSA ECU 33 sets the ABS exhaust valve 52 of the ABS modulator to the communication position II until the pressure switch 64 is turned off. The first brake holding pressure is reduced.
Further, when the pressure switch 64 is turned off by the initial brake holding pressure, the HSA ECU 33 holds the ABS exhaust valve 52 at the shut-off position I as it is, and holds the initial brake holding pressure as it is. .

Further, when the pressure switch 63 on the brake valve 2 side is turned on by further depressing the brake pedal 1, the HSA ECU 33 sets the ABS modulator ABS.
The holding valve 51 is set at the communication position I for a certain period of time to increase the brake holding pressure. Other configurations, operation and effects of the brake control system of the fifth example are the same as those of the first example.

FIG. 7 is a view similar to FIG. 1 showing a sixth embodiment of the present invention. The same components as those in the above-described first example are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the above-described first example, the pressure sensor 55 is provided on the output side of the brake valve 2 of the rear wheel brake system, and the pressure sensor 56 is provided on the right side AB of the rear wheel brake system.
Although provided on the output side of the S modulator 19, the sixth
In the example brake control system, as shown in FIG. 6, in addition to the pressure sensors 55 and 56 of the rear wheel brake system, a pressure sensor 65 is further provided on the output side of the brake valve 2 of the front wheel brake system. 66 is provided on the output side of the ABS modulator 8 of the front wheel brake system, and a pressure sensor 67 is provided on the left side of the rear wheel brake system.
It is also provided on the output side of the BS modulator 18. These pressure sensors 65, 66 and 67 are also HSA EC
It is connected to U33.

In each of the first to fifth examples described above, each of the rear wheel brake systems is one system and the other front wheel brake system performs the HSA operation by estimation control.
In the example brake control system, the HSA control is individually performed for each brake system. Other configurations, operational effects, and effects of the brake control system of the sixth example are the same as those of the first example.

FIG. 8 is a view similar to FIG. 5 showing a seventh embodiment of the present invention. The same components as those in the above-described fourth example are denoted by the same reference numerals, and a detailed description thereof will be omitted.

In the above-mentioned fourth example, the pressure switch 63 for detecting the output pressure of the brake valve 2 is provided separately from the pressure switch for the stop lamp. However, in the brake control system of the seventh example, the brake valve The pressure switches for detecting the output pressure of the passages 2 and 3
, And generally used stop lamp pressure switches 68 and 69 are used. The stop lamp pressure switches 68 and 69 are connected to the HSA ECU 33.
Other configurations of the brake control system of the seventh example are the same as those of the fourth example.

According to the brake control system of the seventh example, since the stop lamp pressure switches 68 and 69 generally used in the past are used, it is not necessary to provide a special pressure switch for exclusive use. Therefore, cost can be reduced. Further, since both the stop lamp pressure switches 68 and 69 of the front and rear wheel brake systems can be used, the reliability is further improved. Other operational effects of the brake control system of the seventh example are the same as those of the fourth example.

In the fourth to seventh examples, one pressure switch and one pressure sensor are combined, two pressure switches 63 and 64 are combined, or two stop lamp pressure switches 68 and 69 are combined with one pressure switch. It goes without saying that the combination with the pressure sensor 56 can be applied to the brake control systems of the second and third examples, respectively, instead of the pressure sensors 55 and 56.

[0078]

As is apparent from the above description, according to the brake control system provided with the slope start assist device according to the present invention, the conventional ABS control-based brake control system utilizes the ABS modulator. The HSA function can be performed without any significant design change. Therefore, since the conventional HSA valve can be omitted, the number of parts can be reduced, and the piping becomes extremely simple. Thus, even if the brake control system has the HSA function, the configuration of the system can be simplified and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first example of an embodiment of a brake control system including a slope start assist device according to the present invention.

FIG. 2 is a diagram schematically showing an example of a conventionally known ABS modulator used in the brake control system shown in FIG.

FIG. 3 is a view similar to FIG. 1, showing a second example of the embodiment of the present invention.

FIG. 4 is a view similar to FIG. 1, showing a third example of the embodiment of the present invention.

FIG. 5 is a view similar to FIG. 1, showing a fourth example of the embodiment of the present invention.

FIG. 6 is a view similar to FIG. 5, illustrating a fifth example of the embodiment of the present invention.

FIG. 7 is a view similar to FIG. 1, showing a sixth example of the embodiment of the present invention.

FIG. 8 is a view similar to FIG. 1, showing a seventh example of the embodiment of the present invention.

FIG. 9 is a diagram showing an example of a brake control system provided with a conventional slope start assist device.

FIG. 10 is a sectional view showing an example of a conventional HSA valve.

[Explanation of symbols]

1: Brake pedal, 2: Dual brake valve,
3, 3 '... air tank, 8, 18, 19 ... ABS modulator, 9, 10 ... front wheel, 11, 22, 23 ... brake actuator, 17 ... double check valve, 20, 21
... front and rear wheels (drive wheels), 20 ', 21' ... rear rear wheels (non-drive wheels), 24 ... ABS / TRC ECU, 25, 26, 27,
28: Wheel speed sensor, 47, 48, 53, 54, 57: Air passage, 49, 50: Relay valve, 51: ABS holding valve, 52: ABS pressure reducing valve, 55, 56, 65, 66, 67 ...
Pressure sensor, 58: TRC electromagnetic switching valve, 61, 62 ... T
RC cut valve, 63, 64, 68, 69… Pressure switch

Claims (6)

[Claims] 1. An air tank for storing compressed air, a brake operation member for performing a brake operation, a brake valve which is operated and output by a brake operation of the brake operation member, and an air having an output pressure of the brake valve or the air tank. A brake actuator for supplying air at a pressure controlled in accordance with the output pressure of the brake valve to generate a brake pressure, and a brake actuator which is opened during normal and anti-skid control pressure increase to reduce the output pressure of the brake valve. Air or the air pressure of the air tank controlled according to the output pressure of the brake valve can be supplied to the brake actuator, and the anti-skid control is maintained and closed when the pressure is reduced to reduce the air pressure of the brake actuator. An anti-skid control holding valve for holding; An anti-skid control pressure reducing valve that closes at all times and at the time of holding and increasing the pressure of the anti-skid control and opens at the time of pressure reduction of the anti-skid control to exhaust the air of the brake actuator and reduce the air pressure of the brake actuator An anti-skid control modulator, first pressure detecting means for detecting an output pressure of the brake valve, second pressure detecting means for detecting an air pressure of the brake actuator, and a wheel speed for detecting a wheel speed of a wheel. A sensor, an accelerator padal depression detection sensor for detecting depression of an accelerator pedal, and when braking, when it is determined that at least one wheel has a tendency to lock based on a wheel speed detection signal from the wheel speed sensor, Holding valve for anti-skid control and pressure reducing for anti-skid control Controlling the anti-skid modulator so as to eliminate the locking tendency by holding, reducing, and increasing the air pressure of the brake actuator; and When the vehicle is stopped by the brake operation by the brake operation, the anti-skid control holding valve is closed and the air pressure of the brake actuator is maintained to maintain the brake operation state, and in this brake operation holding state, A brake operation holding control device that opens the anti-skid control pressure reducing valve and opens the anti-skid control holding valve to release the brake operation holding state based on an accelerator pedal depression detection signal of the accelerator pedal depression detection sensor. That you have Brake control system with a hill-start assist to symptoms. 2. A two-brake system having a dual brake valve, wherein the two-brake system is provided with the modulator for anti-skid control and a brake actuator, respectively. The brake control system provided with the slope start assist device according to claim 1, further comprising a second pressure detection means and a second pressure detection means. 3. The brake control system according to claim 1, wherein both the first and second pressure detecting means are constituted by pressure sensors. 4. The apparatus according to claim 1, wherein the first pressure detecting means comprises a pressure switch, and a plurality of predetermined pressures serving as references for adjusting a brake holding pressure in a brake operation holding state are set. A brake control system provided with the slope start assist device according to claim 1 or 2. 5. The first and second pressure detecting means are each constituted by a pressure switch, and at least the pressure switch of the second pressure detecting means has a hysteresis in an on-pressure and an off-pressure. A brake control system provided with the slope start assist device according to claim 1 or 2. 6. The brake control system according to claim 1, wherein said first pressure detecting means comprises a pressure switch for a stop lamp.