JPH02277931A - Exhaust brake control device - Google Patents

Abstract

PURPOSE:To perform an easy drive by controlling an exhaust brake actuator based on signals from a car speed judging means, a brake pedal judging means, an accelerator pedal judging means, and an acceleration state judging means. CONSTITUTION:When a car speed is very low or an accelerator pedal 3 is not depressed, an exhaust brake is not required, thus it is not operated. When a brake pedal 1 is depressed, the exhaust brake is operated as an aid. When the pedals 1 and 3 are not depressed and the relation between the car speed and the acceleration is in a region A, an engine brake is required, thus the exhaust brake is operated. When the relation is in a region B, no engine brake is required, thus no exhaust brake is applied. In the region C, the engine brake is required or not required depending on the load quantity and the surrounding situation, thus the current exhaust brake state is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exhaust brake control device for controlling an exhaust brake employed in large vehicles such as trucks and buses.

(Prior Art) In a manual transmission vehicle, a conventional exhaust brake is configured to operate when the exhaust brake switch is turned on and the accelerator pedal and clutch pedal are not depressed.

In addition, in vehicles with automatic transmission, the exhaust brake operates when the exhaust brake switch is on and the accelerator pedal is not depressed, or when the exhaust brake switch is on and the accelerator pedal is not depressed. The exhaust brake was configured to operate when the vehicle speed exceeded a set value.

(Problems to be Solved by the Invention) In the above-mentioned conventional configuration, the driver has to judge the driving state and operate the exhaust brake switch on and off, making the operation complicated and troublesome.

(Means for Solving the Problems) In order to solve the above problems, the exhaust brake control device of the present invention includes a brake pedal determining means 2 for determining whether or not the brake pedal 1 is depressed, as shown in FIG. , an accelerator pedal determining means 4 that determines whether the accelerator pedal 3 is depressed, a medium speed determining means 5 that determines the vehicle speed, an acceleration determining stage 6 that determines the acceleration of the vehicle, and an accelerator pedal determining means 4 that determines whether the accelerator pedal 3 is depressed. Preset size 2t-1! A storage means 7 for storing acceleration setting values of the same type, and signals from the vehicle speed judgment means 5, acceleration judgment means 6, and storage means 7 indicate whether the current acceleration is in a first state equal to or larger than the larger setting value. Alternatively, an acceleration state determining means 8 is provided for determining whether the value is a second state that is less than or equal to the smaller set value or a third state that is intermediate therebetween, and the vehicle speed determining means 5, the brake pedal determining means 2, and the accelerator Controlling the exhaust brake actuator 9 based on the signals from the pedal determining means 4 and the acceleration state determining means 8,
When the vehicle speed is below a very low predetermined value and when the accelerator pedal 3 is depressed, the exhaust brake is not activated, and when the vehicle speed is higher than the predetermined value and the accelerator pedal 3 is not depressed, the brake pedal is activated. When l is depressed, the exhaust brake is operated, and when the width speed is higher than the predetermined value and neither the accelerator pedal 3 nor the brake pedal 1 is depressed, the current acceleration is in the first state. The exhaust brake actuator control means is provided for operating the exhaust brake, not operating the exhaust brake in the second state, and maintaining the current state of the exhaust brake in the third state.

(Function) The exhaust brake does not operate when the vehicle speed is below a very low predetermined value and when the accelerator pedal 3 is depressed. When the vehicle speed is higher than a predetermined value and the accelerator pedal 3 is not depressed, but the brake pedal 1 is depressed, the exhaust brake is activated. When the vehicle speed is higher than a predetermined value and neither the accelerator pedal 3 nor the brake pedal 1 is depressed, the exhaust brake operates if the current acceleration is in the first state, and the second
If this is the case, the exhaust brake will not operate and the third
If the condition is , the current exhaust brake condition is maintained.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 2 to 4.

FIG. 2 is a schematic configuration diagram of a vehicle control device employing an exhaust brake control device according to an embodiment of the present invention.
The microcomputer 13 has a CPU 14 (central processing unit), a RAM 15 (random access memory), and an RO.
It is composed of an M16 (read-only memory), a human power interface 17, and an output interface 18. The input terminal of the CPU 14 is the human power interface 17
are connected to various output ends of the shift tower 19, the output end of the exhaust brake switch 20, the output end of the brake pedal stroke sensor 22 that detects that the brake pedal 21 is depressed, and the vehicle speed sensor 23 that detects the vehicle speed. and an output end of an accelerator pedal stroke sensor 24 that detects that the accelerator pedal is depressed. The output end of the CPU 14 is connected via the output interface 18 to various solenoids for switching gears of the transmission 25 and to a solenoid of the exhaust brake actuator 26.

The brake pedal 21 corresponds to the brake pedal 1 in FIG. 1, the brake pedal stroke sensor 22 corresponds to the brake pedal determining means 2 in FIG. 1, and the accelerator pedal stroke sensor 24 corresponds to the accelerator pedal determining means 4 in FIG.
Correspondingly, the vehicle speed sensor 23 corresponds to the vehicle connection judgment stage 5 in FIG. 1, and the exhaust brake actuator 26 corresponds to the exhaust brake actuator 9 in FIG. The acceleration determination means 6, acceleration state determination means 8, and exhaust brake actuator control means 10 shown in FIG. 1 are realized by the CPU 14, and the storage means 7 is realized by the ROM 16.

That is, in the ROM 16, the set values of acceleration relative to vehicle speed are stored in the form of a function or a map, not shown by solid lines a and b in Fig. 3.
The type is memorized, and the CPU 14 determines whether the current acceleration is in areas A, B, or C in FIG. The exhaust brake actuator 26 is controlled based on the determination result and signals from the exhaust brake switch 20, the brake pedal stroke sensor 22, and the accelerator pedal stroke sensor 24.

Next, the operation will be explained. Exhaust brake switch 2
When 0 is off, the CPU 14 does not output a drive signal to the exhaust brake actuator 26, and the exhaust brake does not operate.

When the exhaust brake switch 20 is on, if the vehicle speed is less than a predetermined low speed value of, for example, 7 km/h,
CPU14 is exhaust brake actuator 2
No drive signal is output to 6, and the exhaust brake does not operate. Furthermore, even if the exhaust brake switch 20 is on and the vehicle speed is above a predetermined value, the CPU 1.4 does not output a drive signal to the exhaust brake actuator 26 when the accelerator pedal is depressed.
Exhaust brake does not work. Also, when the exhaust brake switch 20 is on and the vehicle speed is above a predetermined value,
When the accelerator pedal is not depressed, the CPU 4 outputs a drive signal to the exhaust brake actuator 26 by depressing the brake pedal 21 to operate the exhaust brake. Further, when the exhaust brake switch 20 is on, the vehicle speed is above a predetermined value, and the accelerator pedal and the brake pedal 21 are not depressed, the CPU 14 determines whether the current acceleration is in the area A in FIG.
(first state), outputs a drive signal to the exhaust brake actuator 26 to operate the exhaust brake, and if region B (second state), outputs a drive signal to the exhaust brake actuator 26. If it is in region C (third state), the output state to the exhaust brake actuator 26 is continued as it is, and the state of the exhaust brake is maintained as it is.

That is, when the vehicle speed is very low or when the accelerator pedal is depressed, the exhaust brake is not needed and is not activated. Further, when the brake pedal 21 is depressed, the exhaust brake is operated as an auxiliary operation. By the way, in a coasting state where neither the brake pedal 21 nor the accelerator pedal is depressed, the higher the vehicle speed is, the more effective engine braking is needed even if the acceleration is small, and the lower the vehicle speed is, the less the engine brake is needed even if there is some acceleration. . Furthermore, if the deceleration of the vehicle is large (if the absolute value of the negative acceleration is large), no further engine braking is required. Therefore, when the relationship between vehicle speed and acceleration is in region A in FIG. 3, the engine brake needs to be effective, so the exhaust brake is operated. Furthermore, in the case of region B, the engine brake is not required to be effective, so the exhaust brake is not operated. Note that in region C, engine braking may or may not be necessary depending on the load, surrounding circumstances, etc., so the current state of the exhaust brake is maintained. By doing this, in region C, for example, when the exhaust brake is released and deceleration is required, the driver depresses the brake pedal 21 to decelerate, but at that moment the exhaust brake is activated and the driver Since the exhaust brake continues to operate even if the driver releases the brake pedal 21, the effect of engine braking has increased compared to before the brake pedal 21 was depressed. The action of stepping on the button is reduced. Also, in region C, for example, if the exhaust brake is operating and the engine brake does not need to be as effective, if left as it is, the vehicle speed will decrease and move from point P1 to point 22 in Fig. Enter B.

Or the driver depresses the accelerator pedal due to a decrease in vehicle speed. At that moment, the exhaust brake is released and the effectiveness of the engine brake is reduced, so the decrease in vehicle speed becomes smaller, and from then on, the need to press the accelerator pedal to increase the vehicle speed becomes less frequent.

Regarding the operation of the CPU 14 to realize the above control,
This will be explained with reference to the flowchart shown in FIG. C.P.
Under normal conditions, U14 enters the exhaust brake subroutine at predetermined time intervals, and first in step a reads detection signals from the exhaust brake switch 20, brake pedal stroke sensor 22, vehicle speed sensor 23, and accelerator pedal stroke sensor 24, and The acceleration setting value corresponding to the vehicle speed is read from the ROM 16. Next, the process proceeds to step b, where the acceleration is calculated from the vehicle speed, and the process proceeds to step C, where it is determined whether the exhaust brake switch 20 is on. If it is on, proceed to step d to determine whether the vehicle speed is 7 Kll/h or higher, and if it is above, proceed to step e to determine whether the accelerator opening is zero, that is, whether the accelerator pedal is depressed. Decide whether or not.

If the brake pedal 21 has not been depressed, the process proceeds to step f, where it is determined whether or not the brake pedal 21 has been depressed.If it has not been depressed, the process proceeds to step g, where it is determined whether the acceleration is in region A or not. If the acceleration is not in the area A, the process proceeds to step h, where it is determined whether the acceleration is in the area B, and if the acceleration is not in the area B, the process returns. If the exhaust brake switch 20 is off in step C, the process proceeds to step i, and if a drive signal to the exhaust brake actuator 26 is being output, it is stopped, and the process returns. If the vehicle speed is less than 7KII/h in step d, the process proceeds to step i. If the accelerator opening degree is not zero in step e, that is, if the accelerator pedal is depressed, the process proceeds to step i. If the brake pedal 21 is depressed in step f, the process advances to step j, and if the drive signal to the exhaust brake actuator 26 is not output, it is output, and the process returns. If the acceleration is in region A in step g, the process advances to step J. If the acceleration is in region B in step h, the process advances to step i.

In this way, just by turning on the exhaust brake switch 20, the exhaust brake is appropriately controlled according to the driving situation, so the driver can judge whether or not the exhaust brake is necessary while driving and turn the exhaust brake switch 20 on. This eliminates the need for frequent operation, allowing for easy driving.

(Another Example) In the above example, the acceleration was calculated by the CPU 14 based on the signal from the vehicle speed sensor 23, but the present invention is not limited to such a configuration, and an acceleration sensor may be provided. It may be configured to detect acceleration.

Further, in the above embodiment, the exhaust brake switch 20 is provided so that the exhaust brake is not always operated, but the present invention is not limited to such a structure, and the exhaust brake switch 20 is not provided. The exhaust brake may be automatically controlled at all times.

Further, in the above embodiment, an example in which the present invention is applied to a vehicle equipped with an automatic transmission 25 has been described, but it goes without saying that the present invention can also be applied to a vehicle equipped with a manual transmission.

(Effects of the Invention) As explained above, according to the present invention, the exhaust brake is appropriately controlled according to the driving situation, so that the driver can judge whether or not the exhaust brake is necessary while driving and press the exhaust brake switch. It eliminates the need for frequent operations and enables easy driving.

[Brief explanation of drawings]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a schematic configuration diagram of a control device for a vehicle that employs an exhaust brake control device according to an embodiment of the present invention, and Fig. 3 is a diagram showing the vehicle speed stored in the storage means. FIG. 4 is a flowchart showing the operation of the CPU. DESCRIPTION OF SYMBOLS 1... Brake pedal, 2... Brake pedal judgment means, 3... Accelerator pedal, 4... Accelerator pedal judgment means, 5... Vehicle speed judgment means, 6... Acceleration judgment means, 7. . . . Storage means, 8. Acceleration state determination means, 9. Exhaust brake actuator,
10...Exhaust brake actuator control means Patent applicant: Daikin Seisakusho Co., Ltd. Figure 2 Figure 1

Claims (1)

[Claims] 1. A brake pedal determining means for determining whether a brake pedal is depressed; an accelerator pedal determining means for determining whether an accelerator pedal is depressed; a vehicle speed determining means for determining vehicle speed; and a vehicle speed determining means for determining vehicle acceleration. acceleration judgment means, and a magnitude 2 preset according to the vehicle speed.
A storage means for storing set values of acceleration of each type, and signals from the vehicle speed determining means, the acceleration determining means, and the storing means determine whether the current acceleration is in a first state, which is greater than or equal to the larger set value, or which is smaller. acceleration state determining means for determining whether the second state is below a set value or a third state intermediate therebetween, and the vehicle speed determining means, the brake pedal determining means, the accelerator pedal determining means, and the acceleration state determining means. The exhaust brake actuator is controlled based on a signal from the means, and when the vehicle speed is below a very low predetermined value or when the accelerator pedal is depressed, the exhaust brake is not operated and the vehicle speed is reduced to the predetermined value. When the vehicle speed is higher than the predetermined value and neither the accelerator pedal nor the brake pedal is depressed, the exhaust brake is activated when the brake pedal is depressed, and when the vehicle speed is higher than the predetermined value and neither the accelerator pedal nor the brake pedal is depressed. Exhaust brake system that operates the exhaust brake if the current acceleration is in the first state, does not operate the exhaust brake if it is in the second state, and maintains the current exhaust brake state if the current acceleration is in the third state. An exhaust brake control device comprising an actuator control means.