JP2867826B2 - Brake force control method for auxiliary brake device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a braking force of an auxiliary brake device of a vehicle equipped with an antilock brake system.

[0002]

2. Description of the Related Art A large vehicle such as a truck is provided with auxiliary brake means such as an exhaust brake mechanism, an electromagnetic retarder mechanism, and a power tard mechanism in order to improve the durability and reduce the size of the vehicle by assisting a service brake device. A brake device is installed. This auxiliary brake means reduces the driving force transmitted from the engine to the driving wheels to generate an auxiliary braking force, and operates independently of the service brake device.

Therefore, in a truck or the like in which an anti-lock brake system (hereinafter, referred to as ABS) is mounted on a service brake device, when the auxiliary brake means is operated, the ABS is operated and the brake pressure of the service brake device is increased. When the increase / decrease control is started, the controller of the auxiliary brake device automatically releases the operation of the auxiliary brake means to avoid the interference between the braking force of the auxiliary brake means and the operation of the ABS.

[0004]

By the way, the braking force of the auxiliary brake means does not disappear immediately after its operation is released due to the structure of the auxiliary brake means, and it takes some time until it actually disappears. I need it. For this reason, in the conventional braking force control method of the auxiliary brake device, A
Even when the BS starts to operate, the brake force of the auxiliary brake means may remain for a while, and the remaining brake force interferes with the operation of the ABS, and adversely affects the brake pressure control of the ABS. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a brake force control method for an auxiliary brake device which can completely avoid interference with the operation of an ABS. I do.

[0006]

According to the present invention, there is provided a method for controlling a braking force of an auxiliary brake device according to the present invention, which comprises an auxiliary brake device mounted on a vehicle in addition to an anti-lock brake system. When releasing the operation while the anti-lock brake system is operating, set the automatic release condition that is satisfied before the anti-lock brake system starts operating, and when the automatic release condition is satisfied, the auxiliary brake The operation of the device is automatically released.

At this time, it is desirable that the automatic release condition is satisfied when a depression operation of a brake pedal provided in a driver's seat is detected. Preferably, the automatic release condition is satisfied when the deceleration of the drive wheel becomes larger than a predetermined value.

[0008]

Due to its structure, the auxiliary brake device requires some time from when its operation is released to when the auxiliary brake force actually disappears. In the brake force control method for the auxiliary brake device according to the present invention, the operation of the auxiliary brake device is released when an automatic release condition that is satisfied before the start of the operation of the ABS is satisfied. Therefore, after the braking force of the auxiliary brake device completely disappears, the ABS starts to operate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of an auxiliary brake device for implementing a braking force control method according to the present invention. In the drawing, reference numeral 1 denotes an engine. Is transmitted to the rear wheel R via the Reference numeral 5 denotes an anti-lock brake system (ABS). The ABS 5 is controlled by an ABS controller 6 to increase or decrease the brake pressure of a wheel cylinder 7 of a service brake device, and to brake the wheels F and R. To prevent Note that the ABS 5 and the ABS controller 6 are already known, and a detailed description thereof will be omitted. The wheel cylinders 7 are provided for each front wheel F and each rear wheel R.

The auxiliary brake device 10 comprises auxiliary brake means, various sensors, an auxiliary brake controller 14, etc. The auxiliary brake means comprises an exhaust brake mechanism 16, an electromagnetic retarder mechanism 17, and a power tard mechanism 18
It is provided with. The exhaust brake mechanism 16 is a brake means for providing an on-off valve in an exhaust pipe of the engine 1 and reducing a passage area in the exhaust pipe to increase engine exhaust pressure to obtain a braking force. Electromagnetic retarder mechanism 1
Numeral 7 includes, for example, a rotor that rotates integrally with the propeller shaft 3, and a coil that is fixed to the vehicle body and applies a magnetic field to the rotor. The rotor 7 converts the rotational energy of the rotor into heat energy and emits it to release braking force. It is a braking means to get. The power tard mechanism 18 cuts fuel of the engine 1 and adjusts valve timing and the like. When the piston is raised, a positive pressure is generated in the combustion chamber, and when the piston is lowered, a negative pressure is generated in the cylinder to obtain a braking force. Means.

Due to the structure of the auxiliary brake means, it takes some time until the auxiliary brake force actually disappears after its operation is released. The auxiliary brake controller (hereinafter, simply referred to as a controller) 14 includes a microcomputer, a storage device such as a ROM / RAM, an input / output device, and the like. On the input side of this controller 14,
Various sensors such as a wheel speed sensor 12, an auxiliary brake switch 20, a stop lamp switch 22, and the like are electrically connected.

A wheel speed sensor 12 is provided for each wheel F, R. The wheel speed sensor 12 includes a grooved rotor that rotates integrally with the wheel, a pickup coil fixed to the vehicle body, and facing the grooved rotor. The rotation speed of the grooved rotor is magnetically sensed by the pickup coil. Then, the wheel rotation speed ω is detected. Controller 14
Calculates the wheel speed Vw of each wheel by converting the rotational speed ω detected by each wheel speed sensor 12 into a speed corresponding to the vehicle running speed, and calculates the fastest wheel speed Vw among these wheel speeds Vw. From the vehicle speed V.

The auxiliary brake switch 20 is provided on the operation panel of the driver's seat, and is turned on by the driver when the auxiliary brake device 10 is operated. The auxiliary brake switch 20 that has been turned on supplies an ON signal to the controller 20, and the controller 14 that has received the ON signal repeatedly executes a control program described later.

The stop lamp switch 22 is provided in the middle of the pneumatic circuit of the service brake device, and supplies an ON signal to the controller 14 when detecting a pressure generated by a depression operation of a brake pedal (not shown). The wheel speed sensor 12 and the stop lamp switch 22
Are also electrically connected to the input side of the ABS controller 6. Accordingly, similarly to the controller 14, the ABS controller 6 determines the wheel speed Vw of each wheel based on the rotation speed ω detected by each wheel speed sensor 12, and determines the fastest wheel among the wheel speeds Vw. The vehicle speed V is estimated from the speed Vw.

An exhaust brake mechanism 16, an electromagnetic retarder mechanism 17, and a power tard mechanism 18 are electrically connected to the output side of the controller 14. Therefore, the controller 14 can operate and release the operation of the exhaust brake mechanism 16, the electromagnetic retarder mechanism 17, and the power tard mechanism 18. Further, the controller 14 is also electrically connected to the ABS controller 6. Therefore, the controller 14 can recognize whether or not the ABS controller 6 controls the brake pressure of the wheel cylinder 7 through the ABS 5.

The ABS controller 6 calculates the slip ratio of each wheel with respect to the estimated vehicle speed V, and monitors the slip ratio repeatedly at a predetermined time period. Then, when the slip ratio becomes larger than the set value, that is, when the operation start condition of the ABS 5 is satisfied, the operation of decreasing the brake pressure of the wheel cylinder 7 is started.

The storage device of the controller 14 stores an auxiliary brake control program. Hereinafter, the auxiliary brake control program will be described with reference to FIG. This control program is executed by the auxiliary brake switch 20
Is repeatedly executed when is turned on. When the auxiliary brake switch 20 is turned on, the controller 14 first determines whether or not the ABS controller 6 has started the brake pressure increase / decrease control of the wheel brake 7 via the ABS 5 in step S30. Now
Immediately after the auxiliary brake switch 20 is turned on, in this case, when the service brake device is not operating, the slip ratio of each wheel is smaller than the set value, and the ABS controller 6 controls the brake pressure increase / decrease. Has not been implemented. Therefore, in this state, step S
30 is negative (No), the controller 1
4 proceeds to step S32.

Next, in step S32, the controller 14 determines whether or not the automatic release condition of the operation of the auxiliary brake means has been satisfied, that is, whether or not the stop lamp switch 32 has been switched on. Now, since the brake pedal has not been depressed, the stop lamp switch 32 is in the OFF state, so that the determination result of step S32 is negative, and the controller 14 proceeds to step S34.

In step S34, the controller 14
Are auxiliary brake means, that is, the exhaust brake mechanism 16,
When the electromagnetic retarder mechanism 17 and the power tard mechanism 18 are already operating, they maintain their operations, and when the auxiliary brake means is not operating, they start this operation. That is, after executing step S34, the auxiliary brake means is always in the operating state, and the auxiliary brake force acts on the drive wheel R.

Thereafter, the controller 14 ends the execution of the control program. On the other hand, if the driver depresses the brake pedal while the auxiliary brake means is operating,
The stop lamp switch 22 switches to the ON state.
Therefore, the determination result of step S32 is affirmative (Yes), and the controller 14 proceeds from step S32 to step S36.

In step S36, the controller 14 cancels the operation of the auxiliary brake means if it has been activated, and maintains this state if the operation of the auxiliary brake means has already been released. . That is,
After executing step S36, the auxiliary brake means is always in the operation release state. Therefore, when the brake pedal is depressed, the operation of the auxiliary brake means is released,
Instead of this auxiliary braking force, the braking force of the wheel cylinder 7 of the service brake device starts to act on the rear wheel R. At this time, since the service brake device has just been applied, the slip ratio of each wheel is smaller than the set value, and therefore, the operation start condition of the ABS 5 is not satisfied.

Thereafter, the controller 14 ends the execution of the control program. On the other hand, when the braking force of the wheel cylinder 7 of the service brake device increases and the slip ratio of each wheel increases and becomes larger than a set value, that is, when the operation start condition of the ABS 5 is satisfied,
The ABS 5 starts the control for increasing or decreasing the brake pressure of the wheel cylinder 7. The controller 14 has already executed step S36.
Is executed to release the operation of the auxiliary brake means, and the auxiliary brake force that requires some time to actually disappear has completely disappeared at this time. Therefore, the auxiliary braking force does not interfere with the brake pressure increase / decrease control of the ABS controller 6.

Then, when the ABS 5 starts the control for increasing or decreasing the brake pressure of the wheel cylinder 7, the result of the determination in step S30 becomes affirmative, and the controller 14 proceeds from step S30 to step S36. Therefore, during the operation of the ABS 5, the auxiliary brake means is maintained in the released state. Thereafter, the controller 14 ends the execution of the control program.

FIG. 3 shows another embodiment of the brake force control method of the auxiliary brake control device to which the present invention is applied. This control program is also repeatedly executed when the auxiliary brake switch 20 is turned on, similarly to the control program of FIG. First, in step S40, the controller 14 determines whether or not the ABS 5 is performing control to increase or decrease the brake pressure of the wheel cylinder 7. If the determination result is negative, the controller 14 proceeds to step S42, and determines whether the automatic release condition of the operation of the auxiliary brake unit is satisfied, that is, whether the deceleration of the rear wheel R is large. Is determined.

More specifically, the controller 14
First, after calculating an average wheel speed Va of the wheel speeds Vwl and Vwr of the left and right rear wheels R, a deceleration Ga which is a time differential value of the average wheel speed Va is calculated.
There determines greater or not than the set value G _1. The set value G ₁ is set to a value (for example, a value equivalent to 0.75 G (gravitational acceleration)) that is sufficiently smaller than the deceleration G ₀ corresponding to the slip ratio set value used under the operation start condition of the ABS 5. . Accordingly, when the brake is applied to the vehicle and the deceleration Ga starts to increase, the deceleration Ga is first set to the set value G.
After reaching _1, it reaches the deceleration G ₀ considerable slip ratio setting value.

If the deceleration Ga is smaller than the set value G ₁ , the controller 14 determines whether the deceleration G
a is determined not to be large, so that the result of the determination in step S42 is negative, and steps S42 to S44
Proceed to. In step S44, the controller 14 maintains this operating state when the auxiliary brake means is already operating, and activates it when the auxiliary brake means is not operating. That is, after executing step S44, the auxiliary brake means is always in the operating state, and the auxiliary brake force acts on the rear wheel R.

Thereafter, the controller 14 ends the execution of the control program. On the other hand, in step S42, in the case of deceleration Ga is set value G ₁ or more, the controller 14 determines that the deceleration Ga of the rear wheel R is larger,
Therefore, the determination result of step S42 becomes affirmative, and the process proceeds from step S42 to step S46. Step S46
Then, it is determined whether or not a significant slip has occurred in the rear wheel R. To be more specific, the speed differences ΔVl, Δ between the wheel speeds Vwl, Vwr of the left and right rear wheels R and the estimated vehicle speed V.
Vr and the speed differences ΔVl, ΔVr
And the set value ΔV ₁ are compared. Then, at least one of the speed differences ΔVl and ΔVr is used.
Is equal to or greater than the set value ΔV ₁ , the controller 14
It is determined that a remarkable slip has occurred.

If a slip occurs on the rear wheels R during braking of the vehicle, the speed difference ΔV reaches the set value ΔV ₁ before the condition for starting the operation of the ABS 5 is normally satisfied. Therefore, when the rear wheel R slips during braking, first, the determination condition of step S46 is satisfied, and then the operation start condition of the ABS 5 is satisfied. The set value ΔV ₁ is, for example, experimentally obtained and is stored in the storage device of the controller 14 in advance.

If the rear wheel R has a slight slip and the road surface gripping force of the rear wheel R is sufficiently secured, the auxiliary braking force acting on the rear wheel R is released. It is not necessary to do so, and it is not expected that the starting condition of the ABS 5 will be satisfied in the near future. Therefore, in this case, it is not preferable to release the auxiliary brake force even if the automatic release condition of the operation of the auxiliary brake means in step S42 is satisfied. For this reason,
In this case, the determination result of step S46 is negative, and the controller 14 proceeds to step S44. After that, the controller 14 ends the execution of the control program.

On the other hand, when the rear wheel R has a large slip and the rear wheel R loses the road grip force, it is expected that the operation start condition of the ABS 5 will be satisfied in the near future. In this case, the determination result of step S46 becomes affirmative, and the controller 14 proceeds to step S48. In step S48, the controller 14 cancels the operation of the auxiliary brake means if it has been activated, and maintains this state if the operation of the auxiliary brake means has already been released. That is, after executing step S48, the auxiliary brake means is always in the operation release state. Thereby, the operation of the auxiliary brake means is released before the operation of the ABS 5 is started. After this, the controller 1
4 ends the execution of this control program.

Then, when the slip occurring on the rear wheel R further increases and the condition for starting the operation of the ABS 5 is satisfied, the ABS 5 operates. At this point, the operation of the auxiliary brake means has been released, and the braking force has completely disappeared. Therefore, the braking force of the auxiliary brake means does not interfere with the operation of the ABS 5. Then, since the determination result of step S40 becomes positive, the controller 14 proceeds to step S48 without executing steps S42 and S46. Thus, A
During the operation of BS5, the auxiliary brake means is maintained in the released state. Thereafter, the controller 14 ends the execution of the control program.

[0032]

As described above, in the braking force control method according to the present invention, in addition to the anti-lock brake system, the operation of the auxiliary brake device mounted on the vehicle is controlled by the operation of the anti-lock brake system. If the automatic release condition is satisfied before starting the operation of the anti-lock brake system, the automatic release condition is set, and when the automatic release condition is satisfied, the operation of the auxiliary brake device is automatically released. Thus, there is an excellent effect that interference between the braking force of the auxiliary brake device and the operation of the ABS can be completely avoided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an auxiliary brake device in which a brake force control method according to the present invention is implemented.

FIG. 2 is a flowchart showing a braking force control program executed by the controller of FIG. 1 according to an embodiment of the braking force control method according to the present invention.

FIG. 3 is a flowchart of a braking force control program executed by the controller of FIG. 1, showing another embodiment of the braking force control method according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 engine 5 anti-lock brake system (ABS) 6 ABS controller 7 wheel cylinder 10 auxiliary brake device 12 wheel speed sensor 14 auxiliary brake controller 16 exhaust brake mechanism 17 electromagnetic retarder mechanism 18 power tard mechanism 20 auxiliary brake switch 22 stop lamp switch F Front wheel R Rear wheel

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60T 7/12 B60T 8/00

Claims (3)

(57) [Claims] 1. A brake force control method for an auxiliary brake device that releases an operation of an auxiliary brake device mounted on a vehicle in addition to an antilock brake system while the antilock brake system is operating. A brake for an auxiliary brake device characterized by setting an automatic release condition that is satisfied before the operation of the brake system is started, and automatically releasing the operation of the auxiliary brake device when the automatic release condition is satisfied. Power control method. 2. The brake force control method for an auxiliary brake device according to claim 1, wherein the automatic release condition is satisfied when a depression operation of a brake pedal disposed in a driver's seat is detected. 3. The brake force control method for an auxiliary brake device according to claim 1, wherein the automatic release condition is satisfied when the deceleration of the drive wheel becomes larger than a predetermined value.