JP2000039036A - Clutch control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically absorb the change of clutch friction coefficient to improve the riding comfort by detecting the torque of the driving force transmission system on and after a clutch, and controlling the pressing of a clutch plate so as to keep a prescribed value after the torque reaches it. SOLUTION: When the start gear set of a transmission 25 is detected by a gear position sensor 14, and the brake pedal release is detected by a brake sensor 12, a clutch control means 7 controls an electronic governor 23 according to a manipulated variable of an accelerator pedal and controls the clutch plate pressing of a clutch 20 while adjusting the fuel from a fuel injection device 24. In this control, the driving force system torque on and after the clutch 20 is detected, the torque to be transmitted to a propeller shaft 22 at a prescribed value until the vehicle speed reaches a prescribed value after the driving force system torque reaches a prescribed value, and the clutch plate pressing is largely controlled according to the lapse of time when it exceeds this value. Accordingly, even if the friction coefficient of the clutch plate is changed depending on using condition, the change can be absorbed within the control system to smoothly control the connection and disconnection of the clutch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention is applied to automobiles.
The present invention is applied to a vehicle using a mechanical automatic clutch. The present invention relates to an improvement in a method and an apparatus for automatically controlling clutch plate pressing when a vehicle starts moving.

[0002]

2. Description of the Related Art There is known an apparatus which uses a mechanical clutch and automatically controls the pressing of the clutch plate by a program control circuit when the vehicle starts moving. One of the conventional techniques is to calculate a difference between an engine rotation speed and a clutch plate rotation speed with a control circuit so that the difference between the engine rotation speed and the clutch plate rotation speed decreases over time according to a pre-programmed control map. The position of the clutch plate is controlled by the pressure (JP-A-4-337159). There is known a control map that is further devised, performs control based on the rate of change of the rotational speed difference, and performs an operation based on a transfer function model (Japanese Patent Application Laid-Open No. 7-305763).

In a vehicle equipped with such a device, the driver does not need to depress the clutch pedal each time the vehicle starts or shifts, and the pressing of the clutch plate is automatically controlled. Even in a vehicle provided with a clutch pedal in the driver's seat, the clutch pedal is an emergency and does not need to be used in normal driving. The driver is free from troublesome operation of the clutch pedal and can perform smooth driving.

[0004] However, in a vehicle such as a large vehicle in which the use conditions of the clutch greatly change according to the load, if a disturbance occurs in the clutch control system for some reason, the engagement control of the clutch may not be performed smoothly. At this time, a phenomenon of uncomfortable riding such as so-called "hiccup" may appear. With conventional clutch control systems, there is no such uncomfortable riding phenomenon in all situations, including changes in the frequency of use of the clutch due to changes in the load, changes in the clutch temperature, aging, and other changes in operating conditions. It has not been reached.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have studied in detail from various angles a case where the clutch engagement control is not smooth. Then, attention was paid to a phenomenon in which the friction coefficient of the clutch plate changes with the use of the clutch. And it was observed that the coefficient of friction of the clutch plate fluctuated considerably during the half-clutch period in which the clutch plate was slipping. It was found that when the friction coefficient of the clutch plate changed for some reason, the control parameters fluctuated and the control system was temporarily disturbed, causing phenomena such as hiccups.

To suppress this, it is conceivable to reduce the variation in the friction coefficient of the clutch plate. However, it has been found that the variation in the friction coefficient of the clutch plate is complicated and cannot be easily controlled. Was.

The present invention has been made in view of such a background, and an object of the present invention is to provide a control logic that does not directly affect clutch control even if the friction coefficient of the clutch plate changes. And It is an object of the present invention to provide a method and an apparatus that can absorb a change in the friction coefficient of a clutch plate in a control system and smoothly perform clutch control. SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus capable of smoothly performing clutch control even when the temperature or the like of a clutch plate rapidly changes depending on use conditions and the friction coefficient of the clutch plate changes accordingly. And An object of the present invention is to provide a control method and a control device capable of performing clutch control that is convenient for driving operation without the necessity of performing delicate clutch control by pedal operation when an accelerator pedal is not depressed. I do.

[0008]

SUMMARY OF THE INVENTION According to the present invention, even if the coefficient of friction of a clutch provided in a vehicle using a mechanical automatic clutch greatly changes, the change is automatically absorbed to facilitate clutch control. And improve ride comfort.

That is, a first feature of the present invention is that when it is detected that the starting gear is set in the transmission and the brake pedal is released, the fuel supply amount to the engine is adjusted according to the operation amount of the accelerator pedal. In the clutch control method for controlling the clutch plate pressing while detecting, the torque of the driving force transmission system after the clutch is detected, and after the torque reaches a predetermined value (τ ₁ ), the torque is increased to the predetermined value (τ ₁ ). The pressure of the clutch plate is controlled so as to maintain the pressure.

[0010] By adjusting the isochronous control the fuel supply amount, the vehicle speed maintaining said torque to a predetermined value (V ₁₎ to said predetermined value (tau _1), the vehicle speed is a predetermined value (V ₁₎ When it exceeds, the clutch plate pressing is controlled to be large according to the passage of time, and the operation amount of the accelerator pedal after the brake pedal is released is set to a predetermined value (S
₁ ) When it is below, it is desirable to prohibit the control by the torque and control the clutch plate pressing so that the vehicle speed is maintained at the creep speed (Vc).

The control logic that does not directly affect clutch control even when the friction coefficient of the clutch plate changes is as follows. That is, when the driving torque of the engine is constant, the torque τ of the drive system (for example, the propeller shaft) after the clutch is given by τ = kμf (k) where μ is the friction coefficient of the clutch plate and f is the pressing force of the clutch plate. Is a proportionality constant. Therefore, by performing feedback control of the control system so that the torque τ is constant over the most important period of the clutch control from when the clutch is slipping until the vehicle starts, the friction coefficient μ fluctuates over time. However, since the pressing force f is controlled in inverse proportion thereto, stable control can be performed as a whole.

By performing isochronous control of the engine, the engine is controlled so as to have a constant driving torque (not a constant rotation speed). Therefore, the above equation holds over a wide range of the engine speed.

When the vehicle starts after the delicate period of the control of slipping of the clutch, the pressure on the clutch plate is increased with the passage of time to improve the acceleration characteristics of the vehicle.

After the brake pedal is released,
When the accelerator pedal is not depressed, it is necessary to perform the clutch control so as to maintain the vehicle at the creep speed without immediately entering the clutch control with a constant driving torque, which is a feature of the present invention. It is convenient.

A second feature of the present invention is a means for detecting that the starting gear is set in the transmission and the release of the brake pedal, and a means for controlling the engine according to the operation amount of the accelerator pedal after the release of the brake pedal. A clutch control device having a means for adjusting the fuel supply amount and controlling clutch plate pressing, wherein a means for detecting a torque of a driving force transmission system after the clutch is provided, and the means for controlling the clutch plate pressing includes detecting the torque includes means for controlling the clutch plate pressing so as to maintain the vehicle speed is a predetermined value the predetermined value and the torque to reach a (V ₁₎ (τ ₁₎ after a predetermined value (tau ₁₎ It is characterized by.

The means for adjusting the fuel supply amount includes an isochronous control means. The means for detecting the torque of the driving force transmission system includes means for detecting rotation at two points on the rotary drive shaft, and means for detecting the rotation at the two points. Means for comparing the phases of rotation, and the rotation drive shaft is preferably a propeller shaft.

When the brake pedal is released and the accelerator pedal is operated, the isochronous control mode is set, and the torque of the driving force system after the clutch is detected. After the detected torque indicates the predetermined value (τ ₁ ), the pressing force of the clutch plate is controlled so as to maintain the torque (τ ₁ ) until the vehicle speed reaches the predetermined value (V ₁ ).

That is, when the accelerator pedal is operated, the isochronous control mode is set, and when the rotation speed of the internal combustion engine is in a low rotation speed range below a certain value,
The fuel supply amount is rapidly increased to maintain a predetermined target rotational speed. When the rotation speed is maintained and the torque of the internal combustion engine reaches a predetermined value (τ ₁ ), the pressing force of the clutch plate is increased to bring the clutch into a half-clutch state. In the half-clutch state, a load is applied to the internal combustion engine, the rotation speed decreases, and the vehicle speed shows a predetermined value (V ₁ ) or less. However, since the isochronous control is performed, the fuel supply amount is automatically increased and the predetermined torque is increased. (Τ ₁ ) is maintained.

When the vehicle is in the half-clutch state until the vehicle speed reaches a predetermined value (V ₁ ), the pressing force of the clutch plate is controlled in this way to maintain a predetermined torque (τ ₁ ), and the vehicle speed is maintained at a predetermined value (V ₁ ). When (V ₁ ) is reached, the clutch plate is completely meated.

As described above, the torque (τ) of the driving force transmission system is obtained from the friction coefficient (μ) of the clutch plate and the pressing force (f) of the clutch plate. Therefore, even if the friction coefficient (μ) varies, the predetermined value (τ ₁ ) can be maintained by controlling the pressing force (f) of the clutch plate.

The torque (τ) of the driving force transmission system is determined by detecting rotation at two positions on the propeller shaft, which is a rotary drive shaft, and comparing the phases of the rotations at the two positions. The detection accuracy can be improved by increasing the interval between the two positions where rotation is detected.

As described above, by controlling the torque of the driving force transmission system to be constant by changing the pressing force of the clutch plate, even if the friction coefficient of the clutch plate changes due to temperature and other factors, the control system is controlled. It is possible to smoothly control the clutch, and if the accelerator pedal is not depressed, the engine rotation is automatically controlled by isochronous control. The driving operation can be performed smoothly without delicate operation of the pedal and the accelerator pedal.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

[0024]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a main part of an embodiment of the present invention.

The embodiment of the present invention comprises a control means 1, a torque detecting means 2 for detecting a torque of a propeller shaft (rotary drive shaft) 22 connected to a differential gear 21, and a main pressing force applied to the clutch plate of the clutch 20. And a step motor 4 for applying an auxiliary pressing force to the clutch plate.

The torque detecting means 2 is connected to the propeller shaft 22
It comprises a rotation detecting means 5 for detecting each rotation at each location, and a comparing means 6 for taking the detection output and comparing the phases of the rotations at the two locations.

FIG. 2 is a diagram showing the structure of the rotation detecting means in the embodiment of the present invention. The rotation detecting means 5 includes a first detecting means 5a including a rotating plate and a pickup, and a second detecting means 5b.

Further, the control means 1 includes a comparing means 6 and
A clutch control means 7 for controlling the clutch 20; an isochronous control means 8 for sending a control signal to the electronic governor 23 to control the electronic governor 23 to adjust the amount of fuel supplied to the fuel injection device 24; And an observer 9 for calculating and setting the pressing force applied to the clutch plate so as to maintain the torque (τ) detected as a predetermined value (τ ₁ ).

The clutch control means 7 includes a means for detecting that the starting gear is set in the transmission 25 and the release of a brake pedal (not shown), and the operation of the accelerator pedal (not shown) after the release of the brake pedal. Means are provided for adjusting the fuel supply amount of the engine 26 to the fuel injection device 24 and controlling the clutch plate pressing in accordance with the manipulated variable.

The means for controlling the position of the clutch plate includes:
After the detected torque (tau) has reached a predetermined value (τ _1), until the vehicle speed reaches the predetermined value (V _1), controls the clutch plate pressing so as to maintain the torque at a predetermined value (tau ₁₎ Means to do so is included.

The clutch control means 7 includes a temperature sensor 11 for detecting a temperature of the clutch, a brake sensor 12 for detecting a brake operation, an accelerator sensor 13 for detecting an accelerator operation, and a gear position of the transmission 25. The outputs of the gear position sensor 14, the engine rotation sensor 15 for detecting the rotation speed of the engine 26, and the gradient sensor 16 for detecting the road surface gradient are connected.

Step motor 4 and hydraulic cylinder 3
The hydraulic pressure source 10 that supplies hydraulic pressure to the control unit 10 performs a control operation according to a control signal from the clutch control unit 7.

Next, the operation of the embodiment of the present invention configured as described above will be described. 3 is a diagram showing a flow of a clutch control operation in the embodiment of the present invention, FIG. 4 (a) is a diagram showing a change in a stroke in a clutch plate pressing direction by control of the device of the embodiment of the present invention, and FIG. 4 (b) is a propeller shaft torque. (C) is a diagram showing changes in the engine speed and the vehicle speed.

The clutch control means 7 includes the gear position sensor 1
4 detects that the starting gear has been set in the transmission 25, and detects that the brake pedal has been released by the output of the brake sensor 12, and controls the electronic governor 23 in accordance with the operation amount of the accelerator pedal. Thus, the clutch plate pressing of the clutch 20 is controlled while adjusting the fuel supplied from the fuel injection device 24 to the engine 26.

This clutch plate pressing control is performed by the clutch 20
Thereafter, the torque (τ) of the driving force system is detected, and after the torque (τ) reaches a predetermined value (τ ₁ ), the clutch plate pressing is controlled so as to maintain the torque (τ ₁ ).
That is, the vehicle speed (V) is a predetermined value (V ₁₎ to until the torque transmitted to the propeller shaft 22 (tau) the predetermined value (tau ₁₎
When the vehicle speed (V) exceeds a predetermined value (V ₁ ), the clutch plate pressing is controlled to be large as the time (t) elapses.

When the operation amount (S) of the accelerator pedal after the brake pedal is released falls below a predetermined value (S ₁ ), the control based on the torque (τ) is prohibited, and the vehicle speed becomes the creep speed (V _C ). The clutch plate pressing is controlled so as to be maintained.

Here, the clutch control operation will be described in more detail with reference to FIG.

As shown in FIG. 4 (a), when the accelerator pedal is operated, the clutch plate is pressed according to the amount of operation, and when the pressing stroke reaches the position (L ₁ ), the clutch plate is pressed. As shown in (b), the torque (τ) transmitted to the propeller shaft 22 increases. When the pressing stroke (L) becomes (L ₂ ), the clutch 20 enters the half-clutch state. As the torque (τ) increases, the engine speed (N) decreases as shown in FIG.

When the clutch 20 is in the half-clutch state,
The friction of the clutch plate generates heat, and the friction coefficient (μ) is reduced, causing slippage. If the pressing force (f) of the clutch plate remains constant due to this slip, the torque (τ) to be transmitted
Becomes smaller. The clutch control means 7 captures this change in torque from the torque detection means 2 and controls the torque so as to maintain a predetermined value (τ ₁ ).

The torque τ of the propeller shaft 22 is
When the drive torque of No. 6 is constant, the friction coefficient of the clutch plate is μ, and when the pressing force of the clutch plate is f, there is a relationship of τ = kμf (k is a proportional constant).

Therefore, when the friction coefficient μ changes, the torque τ can be kept constant by changing the pressing force f of the clutch plate in accordance with the value.
This clutch plate pressing control can take in the output of the temperature sensor 11 and control the pressing force according to the temperature change.

The torque τ of the propeller shaft 22 is detected by the torque detecting means 2. As described above, the torque detecting means 2 includes the rotation detecting means 5 shown in FIG. 2 and the comparing means 6 provided in the control means 1 shown in FIG.

The first detecting means 5a and the second detecting means 5b of the rotation detecting means 5 detect the rotation speed of the propeller shaft 22. When the torque of the propeller shaft 22 is zero,
As shown in FIG. 5A, no phase difference appears in the rotation waveform detected by the first detecting means 5a and the second detecting means 5b. When a torque is applied to the propeller shaft 22, the propeller shaft 22 is twisted according to the magnitude of the torque, and as shown in FIG. 5B, the first detection means 5a and the second detection means 5b Produces a phase difference (Δω) in the detection output of

Since the phase difference (.DELTA..omega.) And the torque (.tau.) Are in a proportional relationship as shown in FIG. 6, the comparing means 6 takes in the detection outputs of the first detecting means 5a and the second detecting means 5b. , And calculates the torque τ by comparing the rotational phases at two points on the propeller shaft 22.

The calculated torque value is output from the comparing means 6 to the observer 9, and the observer 9 determines the pressing force of the clutch plate necessary for maintaining the torque of a predetermined value (τ ₁ ) for the vehicle model. Calculate and send the value to the clutch control means 7. The clutch control means 7 uses the pressing force as the clutch operation amount as the hydraulic power source 10 and the step
Output to the motor 4.

The hydraulic pressure source 10 supplies pressure oil to the hydraulic cylinder 3 according to the operation amount and presses the clutch plate of the clutch 20. At the same time, the step motor 4 finely adjusts the pressing force by Δf to press the clutch plate.

On the other hand, as shown in FIG. 4C, when the clutch 20 is in the half-clutch state, a load is applied to the engine 26, and its rotation speed (N) decreases. Therefore, the clutch control means 7 activates the isochronous control means 8 when the clutch 20 is in the half-clutch state, and sets the isochronous control mode over the half-clutch period.

When the isochronous control mode is set, fuel injection to the engine 26 is performed according to the isochronous control curve shown in FIG. In the normal control mode, fuel is supplied in accordance with the curve shown by the thin solid line. In the isochronous control mode, when the engine speed decreases to, for example, x in FIG. As shown in the figure, the fuel supply amount is rapidly increased, and control is performed so as to maintain the target rotation speed.

Thus, the isochronous control means 8
When the engine speed drops below a predetermined value in the half-clutch state, the electronic governor 23 is controlled to increase the fuel injection amount from the fuel injection device 24 to the engine 26 to increase the engine speed.

By performing such control of the pressing force of the clutch plate and the isochronous control at the same time, the torque of the propeller shaft 22 is maintained at a predetermined value (τ ₁ ), and phenomena such as “hiccup” at the time of starting are prevented. You.

When the pressing stroke reaches L ₃ , the clutch 20
Is in a complete meet state, the propeller shaft 22 and the differential gear 21 are directly connected, and the vehicle speed increases with an increase in the torque (τ) to enter a running state.

In the isochronous control mode, the output of the gradient sensor 16 is fetched, and the magnitude of the upward gradient indicated by the output, for example, as shown by the thick line in FIG.
, 10%,..., Can be controlled according to a characteristic curve set in accordance with. This can be implemented in a vehicle equipped with a slope start assist device by also using the control software.

[0053]

As described above, according to the present invention, even if the friction coefficient of the clutch plate changes due to the use condition, the change is absorbed in the control system by performing the isochronous control, and The connection / disconnection control can be performed smoothly, and the phenomenon that the ride comfort is deteriorated due to “hiccup” can be eliminated. Also, when the accelerator pedal is not depressed, the engine rotation is automatically controlled by isochronous control, so the driver must perform the driving operation smoothly without delicately operating the clutch pedal and the accelerator pedal. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a rotation detecting unit in the embodiment of the present invention.

FIG. 3 is a diagram showing a flow of a clutch control operation in the embodiment of the present invention.

4A is a diagram illustrating a change in a stroke in a clutch plate pressing direction under control of the apparatus according to the embodiment of the present invention, FIG. 4B is a diagram illustrating a change in a propeller shaft torque, and FIG. 4C is a diagram illustrating an engine rotation speed and a vehicle; The figure which shows the change of speed.

5A is a diagram illustrating a phase difference of a rotation waveform when torque of a propeller shaft is zero in the embodiment of the present invention, and FIG. 5B is a diagram illustrating a phase difference of a rotation waveform when torque is generated.

FIG. 6 is a diagram illustrating a relationship between a phase difference of a rotation waveform of a propeller shaft and torque according to the embodiment of the present invention.

FIG. 7 is a diagram showing an isochronous control curve and a normal control curve according to the embodiment of the present invention.

FIG. 8 is a diagram showing an isochronous control curve and a normal control curve corresponding to a vehicle gradient according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control means 2 Torque detection means 3 Hydraulic cylinder 4 Step motor 5 Rotation detection means 5a First detection means 5b Second detection means 6 Comparison means 7 Clutch control means 8 Isochronous control means 9 Observer 10 Hydraulic source 11 Temperature sensor 12 Brake sensor 13 Accelerator sensor 14 Gear position sensor 15 Engine rotation sensor 16 Gradient sensor 20 Clutch 21 Differential gear 22 Propeller shaft (rotary drive shaft) 23 Electronic governor 24 Fuel injection device 25 Transmission 26 Engine

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Kiyoaki Miyazaki 3-1-1, Hinodai, Hino-shi, Tokyo Hino Automotive Industry Co., Ltd. Ground F-term (reference) 3J057 AA04 BB04 GA74 GB02 GB05 GB19 GB22 GB27 GB30 GB32 GD02 HH02 JJ01

Claims (8)

[Claims] When a start gear is set in a transmission and a release of a brake pedal is detected, a clutch for controlling clutch plate pressing while adjusting a fuel supply amount to an engine in accordance with an operation amount of an accelerator pedal. the control method, a clutch plate pressed into detects the torque of the driving force transmission system since the clutch, is after the torque has reached a predetermined value (tau ₁₎ the torque to maintain the predetermined value (tau ₁₎ A clutch control method characterized by controlling. 2. The clutch control method according to claim 1, wherein the fuel supply amount is adjusted by isochronous control. 3. The torque is maintained at the predetermined value (τ ₁ ) until the vehicle speed reaches a predetermined value (V ₁ ).
3. The clutch control method according to claim 1, wherein when the value exceeds ₁ ), the pressure of the clutch plate is controlled to increase with time. 4. The clutch control method according to claim 1, wherein
When the operation amount of the accelerator pedal after the release of the brake pedal is equal to or less than a predetermined value (S ₁ ), the control by the torque is prohibited, and the clutch plate pressing is performed so that the vehicle speed is maintained at the creep speed (Vc). A clutch control method to control. 5. A means for detecting that a start gear has been set in a transmission and a brake pedal has been released, and that the fuel supply to the engine is adjusted according to the operation amount of an accelerator pedal after the brake pedal is released. A clutch control device comprising: means for controlling clutch plate pressing; means for detecting torque of a driving force transmission system after a clutch, wherein the means for controlling clutch plate pressing determines that the detected torque is a predetermined value ( τ ₁ ), the vehicle speed becomes a predetermined value (V ₁ )
And means for controlling the pressing of the clutch plate so as to maintain the torque at the predetermined value (τ ₁ ) until the pressure reaches the predetermined value (τ ₁ ). 6. The clutch control device according to claim 1, wherein the means for adjusting the fuel supply amount includes an isochronous control means. 7. The means for detecting the torque of the driving force transmission system includes means for detecting rotation at two points on the rotary drive shaft, and means for comparing the phases of the rotations at the two points. The clutch control device according to any one of the preceding claims. 8. The clutch control device according to claim 7, wherein said rotary drive shaft is a propeller shaft.