JPH01224415A - Exhaust brake controller - Google Patents

Abstract

PURPOSE:To prevent the lock of car wheels by conducting a training for the opening of an exhaust brake valve, and generating the force of exhaust brake in opposition to a predetermined deceleration on the basis of the weight of a vehicle and the resistance of travel sought by a movement equation using a car speed and the revolution number of an engine at this time. CONSTITUTION:AT the time of the necessity of the force of exhaust brake in which an exhaust brake switch 9, an acceleration switch 10 and a clutch switch 11 are all 'ON', a training is conducted by means of a controller 8 at the time of the operation of a vehicle. That is to say, a step motor 7 is controlled so that the valve opening of an exhaust brake valve 6 may become two opening values previously set, and the outputs of a revolution number sensor 4 and a car speed sensor 5 at the time of each opening control are read in. Next, the force of temporary brake added on a drive shaft at every valve opening is calculated, and the resistance of travel and the weight of a vehicle are obtained by using a movement equation from its calculated value. And the exhaust brake valve 6 is controlled so that the force of exhaust brake opposing a predetermined deceleration may be generated from the resistance of travel and the weight of the vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust brake control device, and particularly to a device that controls exhaust brake force by opening and closing an exhaust brake valve provided in an exhaust passage of an engine. be.

[Prior Art] As a device for controlling exhaust braking force by opening and closing exhaust brake valves, the present applicant has developed a device for controlling braking force by selectively opening and closing a plurality of exhaust brake valves.
JP-A-60-88 which controls braking force by controlling the opening of an exhaust brake valve and the device shown in Japanese Patent Publication No. 2929.
proposed a device shown in Japanese Patent No. 827.

In the device disclosed in Japanese Patent Application Laid-open No. 60-88827, as shown in FIG.
The solenoid valve 23 is actuated by the output signal of the control unit 8 which controls the exhaust brake motor based on the signal from the deceleration sensor 28, and the air from the air tank 24 drives the air cylinder 22.
The exhaust brake valve 6 provided in the exhaust pipe 2 moves via the servo motor 25, and the opening degree of the exhaust brake valve 6 is controlled by a servo motor 25 based on an output signal from the control unit 8.
The gearbox 26 controls the position of the stroke adjustment disc 27, and the stroke adjustment disc 27 controls the stroke amount of the link machine [21].

Also, as a means of constant speed driving, Japanese Patent Application Laid-Open No. 61-92936
In the device disclosed in the publication, the exhaust brake force is controlled by opening and closing the exhaust brake valve using a vacuum cylinder that operates based on a signal from a control unit ° that controls the exhaust brake force based on a vehicle speed signal. It was done.

[Problems to be Solved by the Invention] In the conventional device as described above, the exhaust brake valve is controlled to achieve the set vehicle speed or deceleration, but the vehicle weight and running resistance are not taken into consideration. If the vehicle is operated using the vehicle speed and engine speed as parameters when the vehicle is running lightly, such as when the vehicle is empty or with only a tractor head, the braking force will be too large, causing the tires to lock and slip, or in the worst case scenario, cause the brake to roll over. There was a point.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an exhaust brake control device that can control exhaust brake force corresponding to all types of vehicles and running conditions by taking vehicle weight and running resistance into consideration.

[Means for Solving the Problems] As a means for solving the above problems, the exhaust brake control device according to the present invention includes an engine rotation speed sensor, a vehicle speed sensor, and a means for adjusting the opening degree of the exhaust brake valve. By training the valve opening when the exhaust brake switch is activated, an exhaust brake force corresponding to a predetermined deceleration is generated based on the engine speed and vehicle speed at that time, as well as the vehicle weight and running resistance determined from the vehicle's equation of motion. and a controller for controlling the adjusting means so as to control the adjustment means.

[Function] In the present invention, when the exhaust brake switch is activated, the opening degree of the exhaust brake valve is trained, and the engine speed and vehicle speed from each sensor at this time are used to determine the vehicle's equation of motion. The weight and running resistance are calculated, and based on these calculated values, the opening degree of the exhaust brake valve installed in the engine's exhaust system is controlled to obtain an exhaust brake force corresponding to a preset deceleration.

[Example] Hereinafter, an example of the exhaust brake control device according to the present invention will be described.

FIG. 1 is an overall configuration diagram of an embodiment of an exhaust brake control device according to the present invention, in which 1 is an engine, and 2 is an engine 1
, 3 is the transmission of the engine 1, 4 is the rotation speed sensor of the engine 1, 5 is the propeller rotation speed sensor as a vehicle speed sensor, 6 is the exhaust brake valve installed in the exhaust pipe 2, 7 is the exhaust brake valve 6 is a step motor as an opening adjustment means, 8 is a controller, 9 is an exhaust brake switch, 10 is an accelerator switch that is turned on when the driver is not pressing the accelerator pedal, and 11 is turned on when the clutch is connected. The clutch switch is shown in the figure below.

FIG. 2 is a flowchart of an exhaust brake control program stored and executed by the controller 8 of FIG. 1, and the operation of the configuration of FIG. 1 will be explained based on this flowchart.

First, the controller 8 performs step 8 of FIG. 2 to check whether exhaust braking force is required.
In steps 1 to S3, it is checked whether the exhaust brake switch 9 (which is turned on and off by the driver of the vehicle), the accelerator switch 10, and the clutch switch 11 are all on. In this case, if even one of these switches is off, it is determined that the exhaust brake force is not necessary and therefore there is no need to control the exhaust brake force, and the exhaust brake is released (exhaust brake valve opening degree is 90"). , (same step 51
2) Skip this control program.

Normally, when exhaust braking force is required, the driver is likely to be stepping on the foot brake pedal (not shown), but when the foot brake is also used, the vehicle speed may suddenly decrease. Therefore, when controlling in this case, if only the exhaust brake force is considered without considering the foot brake force, the combined brake force of both will become too large against the vehicle and cause the wheels to lock, so the foot brake force will be During use, if the exhaust braking force is gradually increased to supplement the foot braking force, the foot braking force will work effectively, there will be less danger, and the driver will have a good feeling.

Therefore, it is preferable to perform the subroutine P shown in FIG. 3 after step S3 in FIG. 2. That is, in step S21 in FIG. When it is determined that the foot brake is being used, the step motor 3 is gradually operated to increase the exhaust brake force little by little (step 522), and the step S23 is again checked to see if the foot brake is being used. > If it is determined that the foot brake is still in use, the process returns to step S22 and the step motor is further activated to increase the exhaust brake force, but if it is determined that the foot brake is not in use, subroutine P is ended and the process shown in FIG. Proceed to step S4.

If all of the above switches are on, exhaust braking force is required and its control is also required, so the process proceeds to step S4.

In step S4, the controller 8 performs training, which is a preliminary step to ultimately finding the vehicle weight W and running resistance R in step S5.
The controller 8 controls the step motor 7 so that the opening degree α of the exhaust brake valve 6 becomes the preset small opening degree values of 80° and 70°. Then, the engine rotation speed and vehicle speed during each opening control are read from the rotation speed sensor 4 and vehicle speed sensor 5, respectively. At the same time, the read engine rotation speed (Nl, N2) and the valve opening of the exhaust brake valve 6 are read. Based on the angles of 80° and 70°, the exhaust brake forces Bl' and B2' at the respective valve opening degrees are determined from the exhaust brake levers shown in FIG. 6 (points X and Y in the figure).

Since these exhaust braking forces Bl' and B2' are not values on the drive shaft, the engine rotational speed (Nl, N2
), the gear ratio in the transmission 3 calculated from the vehicle speed (Vl, V2), the final gear ratio and tire radius stored in the controller 8 in advance, and the following calculation formula (1
) to calculate the provisional braking forces B1 and B2 actually applied to the drive shaft of the vehicle.

Incidentally, the vertical axis of the map shown in FIG. 6 may be set to a value converted using equation (1).

On the other hand, the vehicle decelerations ΔVl/Δt and ΔV2/Δt are determined from the change in vehicle speed when the valve openings are set to 80° and 70°, and the following is calculated based on the provisional braking forces B1 and B2 determined above. Running resistance R and vehicle weight W are calculated using simultaneous equations of motion (2) (step S5).

To W U B 1-R=″1″ Δt...Formula (2)%Formula% Here, the above equation of motion (2) is the known equation of motion F=
It is an equation based on mα, and since G indicates gravitational acceleration, W/G represents - (mass), and 8V/Δt represents α (acceleration).On the other hand, the braking force B is in the opposite direction to the vehicle. Since it acts as a driving force F, the value obtained by subtracting the running resistance R from the braking force B becomes the force acting on the vehicle.

By calculating the simultaneous equations as described above, the running resistance R and the vehicle weight W, which are unknown quantities, are obtained.

As mentioned above, since the running resistance R and vehicle weight W have been determined through training, the controller 8 uses these values R, W and an appropriate deceleration A (this is measured in advance) stored in the ROM of the controller 8 in advance. The exhaust braking force B, which corresponds to the optimum value for the riding comfort of the human being, is calculated from the above equation of motion (2) (in this case, there is no need to make simultaneous equations) (step S6).

Here, in order to make the obtained exhaust brake force BS correspond to the deceleration A described above and to make the control safer and more comfortable, the fourth section is performed in which the exhaust brake force BS is corrected by a coefficient based on the coefficient of friction of the road. Preferably, subroutine Q is executed.

To briefly explain subroutine Q in FIG. 4, first, the driver selects a road surface condition selection switch (not shown) from among a plurality of road conditions R (for example, rainy, snowy, gravel, etc.). Read the position (step 531 in Figure 4), and multiply the exhaust brake force BS obtained in step S6 in Figure 2 by a coefficient (for example, 0.8) corresponding to this position ML (step 532 in Figure 2). The exhaust braking force BR is calculated by taking into account the frictional force of the road. Then, subroutine Q ends.

Next, the controller 8 generates an exhaust brake force Bs' (this is the obtained BS
The valve opening degree αS of the exhaust brake valve 6 is determined based on the value calculated backward from equation (1) and the engine speed (step S7 in FIG. 2), and the valve opening signal corresponding to the valve opening degree αS is sent to the step motor. 7 (step S8).

Then, since the deceleration actually deviates from the set deceleration A, the deceleration A' at this point must be calculated from ΔV/Δt (step S9), and the deceleration A must be checked to see if it has reached the preset deceleration A. 510), if it is determined that A'≠A, steps 86 to SIO are repeated to control the exhaust braking force Bs to match the deceleration A.

When it is determined that A' = A, the same step 5 is repeated in which it is checked whether the exhaust brake switch 9 is off or not.
ll), if it is determined to be off, the exhaust brake is released (all exhaust brake valves t7Ff) (step 5L2), and the exhaust brake force control program is ended.

If the driver turns on the constant speed running switch (not shown) in order to exit the vehicle at a constant speed when the running resistance R and vehicle weight W are determined in step S5 of FIG. 2 above, the above braking force control program You can drive at a constant speed using the same method.

To briefly explain this based on subroutine R shown in FIG. 5, the controller 8 first determines whether a constant speed running switch (not shown) is on (step 54 in FIG. 5).
1), and when it is determined that this switch is on, the vehicle speed at this point is read and from the above equation of motion (2),
Find the exhaust braking force Bc to keep the vehicle speed constant (step 542). This is because the deceleration △V/Δt is zero when driving at a constant speed in the equation of motion (2).
It is determined from C=B=R.

Then, similarly to step S7 in FIG. 2, the exhaust brake valve opening degree αC is determined from the exhaust brake lever shown in FIG. 6, and the opening degree of the exhaust valve 6 is controlled by the step motor 7 (step 543).

In this case, Bc is equal to the running resistance R, so it is a constant value, but when the running condition of the vehicle changes, the
As shown in Publication No. 92936, normal constant speed driving control (step 544) in combination with fuel injection control is performed, or
Alternatively, the running resistance R may be recalculated. During constant speed running, steps 842 to S44 are repeatedly executed, and if it is determined that the constant speed running switch is off, step S1 in FIG.
The process advances to step 2 and subroutine R is ended.

[Effects of the Invention] As described above, in the exhaust brake control device of the present invention, the exhaust brake valve opening degree is trained, and the running resistance and vehicle weight are determined by the equation of motion using the engine speed and vehicle speed at this time. Since the exhaust braking force is generated in accordance with the preset deceleration, the braking force is too large even for light vehicle conditions such as an empty car or a tractor head only, preventing the wheels from locking and slipping. This eliminates the occurrence of accidents and falls, and it is possible to achieve the effect of realizing safe and comfortable driving.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing one embodiment of an exhaust brake control device according to the present invention, FIG. 2 is a flowchart of a program executed by a controller used in the present invention, and FIGS. FIG. 6 is a flowchart of a program preferably executed by the controller used in the invention, FIG. 6 is a map diagram for exhaust brake force control according to the invention, and FIG. 1 is a configuration diagram of a conventional exhaust brake control device. In FIG. 1, 1 is an engine, 2 is an exhaust pipe, 4 is a rotational speed sensor, 5 is a vehicle speed sensor, 6 is an exhaust brake valve, 7 is a step motor, 8 is a controller, 9 is an exhaust brake switch, In the figures, the same symbols indicate the same or equivalent parts.

Claims (1)

[Claims] By training the engine rotation speed sensor, vehicle speed sensor, means for adjusting the opening degree of the exhaust brake valve, and the valve opening degree when the exhaust brake switch is activated, the engine rotation speed, vehicle speed, and vehicle motion at that time can be determined. An exhaust brake control device comprising: a controller that controls the adjustment means to generate an exhaust brake force corresponding to a predetermined deceleration based on vehicle weight and running resistance determined from an equation.