JPH0637165B2 - Driving force control device for self-propelled vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a driving force control device for a self-propelled vehicle such as an automobile, which has a small slip by controlling the rotational speed of driving wheels. It has been devised to obtain various driving forces and can be applied to automobiles, tractors, motorcycles and the like.

[Conventional technology]

As a driving force control device, a slip characteristic of a driving wheel or a traveling characteristic value such as a rotation speed is compared with a threshold value set based on the rotation speed of a driven wheel, and a constant value is set with respect to this threshold value. Related to this, there is known a control device that controls the braking force acting on the drive wheels so that the traveling characteristic value of the drive wheels is maintained.

[Problems to be solved by the invention]

For example, if the clutch is disengaged due to gear change, etc., the driving force that has been transmitted until now will not be transmitted to the driving wheels, and the driving force of the driving wheels will suddenly decrease. For example, since the brakes are constantly applied to the drive wheels, there is a problem in that the rotational speed of the drive wheels rapidly decreases as the clutch is cut off, causing the drive wheels to enter a locking state and excessively slipping.

[Means for solving problems]

This invention has been devised so as to prevent the drive wheels from becoming locked when the clutch is turned off during braking force control.The structure is such that the rotation speed detecting means (1) of the drive wheels (1) is 19), a brake device (B) that applies a braking force corresponding to the brake pressure to the wheels, a threshold value setting means (20) for setting a threshold value, and a driving wheel (1) for this threshold value. A control unit (23) configured to instruct the brake device (B) to increase or decrease or maintain the brake pressure in order to control the rotation speed of the drive wheel (1) by comparing the traveling characteristic values. In the driving force control device,
A clutch disconnection detector that detects the clutch disconnection operation of the clutch part (C) that connects and disconnects the power from the engine to the traveling speed change mechanism.
(S ₃ ) is provided, and the control unit (23) is configured to output a command for discharging the brake pressure to the brake device (B) by the detection operation of the clutch disconnection detector (S ₃ ). Is a driving force control device for a self-propelled vehicle.

[Action]

When the clutch unit (C) is in the connected state, the brake pressure is controlled by the command of the control unit (23) so that the traveling characteristic value of the drive wheel (1) approaches the threshold value, and the braking device ( B)
Controls the rotation speed of the drive wheel (1), and stable travel is performed by the drive wheel (1) to which an appropriate drive force has been transmitted. If part (C) is turned off, the clutch off detector
(S ₃ ) performs a detection operation, and the control unit (23) outputs a command to discharge the brake pressure to the braking device (B) accordingly, so that the lock of the driving wheel (1) by the brake is prevented. Thus, for example, a smooth gear shift operation is performed.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. Second
FIG. 1 shows a circuit diagram of a driving force control device applied to an automobile as an example of a self-propelled vehicle, and FIG. 1 shows a block diagram thereof, for example, rear left and right drive wheels (1), (1) and the front driven wheels (2) and (2) are such that the braking force acts by the action of the brake device (B), and the exemplified brake device (B) is the above-mentioned respective wheels. In the brake cylinder (4) provided corresponding to the rotor (3) of (1) and (2), the pressure oil of the master cylinder (6) is transferred to the proportional valve (4) as the brake pedal (5) is depressed. PV) and the gate valve (GV), or the pressure of the pump (7) by the opening or closing operation of the hold valve (HV) and the decay valve (DV) controlled as described below. As the oil is supplied, the brake piston (8) has a structure in which the brake shoe is brought into pressure contact with the rotor (3). Therefore, the proportional valve (PV) has a function of changing the ratio of the amount of pressure oil supplied to each of the wheels (1) and (2), and the gate valve (GV) has its opening function. The pressure oil of the master cylinder (6) can be supplied to the brake cylinder (4) by the operation or closing operation, or
Hold valve
(HV) has a function of supplying pressure oil of the pump (7) to the brake cylinder (4) by its opening operation or closing operation, or interrupting the supply, and the decay valve (DV) has its opening operation or By the closing operation, the pressure oil in the brake cylinder (4) is discharged or the discharge is shut off.

In addition, the illustrated throttle device has a fuel control valve (10) according to an operation amount of an accelerator operation member (9) such as an accelerator pedal.
Is opened, and the amount of fuel corresponding to this opening is supplied to the engine. The clutch part (C) that connects and disconnects the power from the engine to the traveling speed change mechanism is a friction plate (14) that is constantly pressed against the clutch case (12) connected to the crankshaft (11) by a spring (13). ), The power is transmitted to the clutch output shaft (15), and the friction plate (14) is separated from the clutch case (12) by the depression operation of the clutch pedal (16), and the clutch is cut off. As a clutch disconnection detector (S ₃ ) configured to detect the clutch disconnection operation, for example, a micro switch that is turned on by the depression operation of the clutch pedal (16) is provided.

Next, an example of the control means will be described. Each drive wheel (1)
The rotation speed is measured by the rotation sensor (S ₁ ) and the rotation speed calculation unit (1
The rotational speed detecting means (19) for detecting the rotational speed (V _D ) as an example of the traveling characteristic value of the drive wheel (1) (for example, rotational speed, slip rate, adjustment rate, etc.) is configured in 8). . A first threshold value (V ₁ ) as a desired rotation speed for controlling the rotation speed of the drive wheel (1) and a second threshold value (V ₁ ) faster than this
_{In the} illustrated example as the threshold setting means (20) for setting ₂ ),
The rotation speed detected by the rotation sensor (S ₂ ) is calculated as the rotation speed (V _T ) of the driven wheel (2) by the rotation speed calculation unit (21), and the third speed is calculated.
As illustrated in the upper part of the figure, the speed (ΔV ₁ ) and (ΔV ₂ ) are added to this rotation speed (V _T ) respectively, and the first threshold value (V ₁ ) and the second threshold value (V ₂ ) are calculated and set respectively, and the threshold value setting means (20)
Is composed of a micro computer (17).

The control unit (23) provided in the microcomputer (17) controls the rotation speed (V _D ) of the drive wheel (1) to the first threshold value (V ₁ ) and the second threshold value (V ₂ ). On the other hand, the opening / closing control of each of the gate valve (GV), the hold valve (HV), and the delay valve (DV) can be instructed by determining the size of the gate valve (GV) and the acceleration state. That is, the upper part of FIG. 3 shows the variation of the rotation speed (V _D ) of the drive wheel (1), the middle part of the diagram shows the progress of the opening / closing state of the gate valve (GV), and the lower part of the diagram. , The progress of the brake pressure in the brake cylinder (4) is illustrated, and the control command of the control unit (23) is illustrated as a flow chart in FIG.

When the self-propelled vehicle is started, control is opened (step),
With the gate valve (GV) still open, hold valve (H
V) and the D-valve (DV) are both closed (step), the braking operation by the brake pedal (5) remains possible, and the rotation speed (V _D ) is the first threshold value (V _D ). The initial acceleration (α) of the drive wheel (1) is calculated by the initial acceleration calculation unit (18) only within the time (to) until it reaches ₁ ), and the threshold setting means (20) When the set initial acceleration value (α ₁ ) is exceeded, or when the rotational speed (V _D ) exceeds the first threshold value (V ₁ ) (step), the gate valve (GV ) Is closed (step) to disable the operation of the brake pedal (5).

Except for a sudden accelerator depression on a very low coefficient of friction road, the control is sufficient to start at the time when the rotation speed (V _D ) exceeds the first threshold value (V ₁ ). In such a case as well, in order to start the control earlier, the acceleration is determined even in the range of V _D ≦ V ₁ , and when α ≧ α ₁ , the case is Judge and hold valve (HV)
Is opened for a short Δt seconds (step), and a light pressure oil is applied to the brake cylinder (4) beforehand. As a result, the brake piston (8) is slightly moved to eliminate the play between the brake shoe and the rotor (3), and the braking force is quickly increased when a sudden slip occurs due to a sudden start on a slippery road surface. To be able to work. When the clutch unit (C) is in the clutch state and the control start time has passed, it is detected whether the rotation speed (V _D ) is increasing or not, and the difference between the previous time and the current time of the rotation speed (V _D ) is detected. If the speed is increasing, the rotation speed (V _D ) becomes the first threshold value (V
When it exceeds ₁ ) (t _a , t _b , t _{c in} Fig. 3), the hold valve (HV) is opened and the decay valve (DV) is closed (step). The pressure oil is supplied to the brake cylinder (4) to increase the brake pressure. When the rotation speed (V _D ) is below the first threshold value (V ₁ ) while it is increasing (te in FIG. 3), the hold valve (HV) is closed and the decay valve (DV) is opened (step). ) Notably, the brake cylinder
The pressure oil in (4) is discharged and the brake pressure is reduced,
When the rotation speed (V _D ) is not increasing, the rotation speed (V _{D
When D} ) does not exceed the first threshold (V ₁ ) (t _{f in} Fig. 3)
When the rotation speed (V _D ) exceeds the first threshold value (V ₁ ) and does not reach the second threshold value (V ₂ ), the braking pressure is reduced like step ( Tg, tn, t in Fig. 3
i) means that both the hold valve (HV) and the delay valve (DV) are closed (step), which means that the brake cylinder
The pressure oil in (4) is retained, and when the rotation speed (V _D ) exceeds the second threshold value (V ₂ ) during deceleration (tj, tk), the hold valve (HV) is closed and the delay valve (DV) ) Is opened (step), and the brake pressure is reduced.

When the clutch cut detector (S ₃ ) detects the clutch cut operation of the clutch section (C) during the above control (time t in FIG. 3).
l), close the hold valve (HV) and open the decay valve (DV) (step,) discharge the brake pressure (tm),
When the clutch part (C) is operated again to enter the clutch (tn), the control returns to the above-mentioned control (after tp in FIG. 3). Then, by repeating such control operation, the rotational speed (V _D ) of the drive wheel (1) gradually reaches a certain relationship in which it approaches the first threshold value (V ₁ ) ((tg in FIG. 3). )). When the rotation speed (V _D ) does not exceed the first threshold value (V ₁ ) even after a certain time t ₁ seconds has elapsed since the hold valve (HV) opened (see FIG. 3). Tx) is the short time (t
₂ ) Only the decay valve (DV) is left open to discharge the high pressure oil in the brake cylinder, which causes the high pressure oil in the brake cylinder (4) to flow back into the master cylinder (6). Make sure the pins inside the cylinder are not damaged and release the brake completely. After that, open the gate valve (GV) (step,
,,), Drive wheels as control ends
In the case of (1), the stable drive state with a small slip is maintained without exceeding the first threshold value (V ₁ ).

If the brake pedal (5) is depressed during the above control operation, the decay valve (DV) is opened for t ₂ seconds to drain all the pressure oil in the brake cylinder (4) and the master cylinder (6). The pressure oil inside is prevented from flowing backward, and then the gate valve (GV) is opened to restore the brake operation by the brake pedal (5).

Further, in the above-described embodiment, the drive wheel (1) is a single,
Any of a plurality may be used, a generator type rotation sensor may be used as the rotation speed detection means (19), and the braking device (B)
Can be either air or hydraulic, and threshold setting means (2
0) is not limited to the illustrated example, and the first threshold value (V ₁ ) and the second threshold value (V ₂ ) are set to a constant speed (ΔV ₁ ) with respect to the rotation speed of the driven wheel (2). ), (ΔV ₂ ) as well as variable speeds may be added respectively, and the values may be set to values not related to the driven wheels (2).

In FIG. 2, reference numeral (24) is a pressure switch, and reference numeral (25) is an accumulator.

〔The invention's effect〕

The driving force control device for a self-propelled vehicle according to the present invention is configured as described above, and when the clutch portion (C) is in the connected state, the driving characteristic value of the driving wheel (1) is a threshold value. The brake pressure is controlled by the command of the control unit (23) so that the braking device (B) controls the rotation speed of the driving wheel (1) so that an appropriate driving force is transmitted. The driving wheel (1) ensures stable running, and when the clutch part (C) is turned off during this braking force control, the clutch off detector (S ₃ ) detects the operation. As a result, the control unit (23) outputs a command to discharge the brake pressure to the brake device (B), so that the lock of the drive wheel (1) due to the brake is prevented and the smooth shift operation is performed. It will be carried out and prevents excessive slipping during starting and running of the self-propelled vehicle Tree, effective driving force control can be achieved.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a block diagram of a control device, FIG. 2 is a circuit diagram of the control device, FIG. 3 is a control characteristic diagram, and FIG. 4 is a flow chart. Symbol explanation (1) …… Drive wheel, (19) …… Rotation speed detecting means (20) …… Threshold setting means, (23) …… Control unit (B) …… Brake device, (C) …… Clutch section (S ₃ ) …… Clutch break detector

Claims (1)

[Claims] 1. A driving wheel rotational speed detecting means, a braking device for applying a braking force corresponding to a brake pressure to the wheel, a threshold value setting means for setting a threshold value, and a driving wheel for the threshold value. In order to control the rotational speed of the drive wheels by comparing the traveling characteristic values of, in the driving force control device having a control unit configured to instruct the brake device to increase or decrease or maintain the brake pressure, A clutch disconnection detector that detects the clutch operation of the clutch part that connects and disconnects the power from the engine to the traveling speed change mechanism is provided, and the command to output the brake pressure is output to the brake device by the detection operation of this clutch disconnection detector. A driving force control device for a self-propelled vehicle, characterized in that a control unit is configured in the.