JPH03125031A - Control device for automatic take-off clutch - Google Patents

Abstract

PURPOSE:To prevent generation of engine stop and the like when an engine speed is over a prescribed quantity against a target value and the rate of change is negative by restraining increase of a feed forward quantity corresponding to a throttle opening. CONSTITUTION:At take-off, a target engine speed is instituted by a deciding means 103 corresponding to a throttle opening theta, PI computation 106 is performed with deviation from the actual engine speed Ne, a feed forward quantity from a deciding means 101 is adjusted, PID computation 109 is performed with deviation from clutch pressure Pc, and a take-off clutch is duty controlled. Further, the target line pressure is instituted by a setting means 111. When the engine speed Ne is over a prescribed quantity against the target value and the rate of change is negative, a control deciding means 114 opens a switch 115, the value before opening is held with a first-order lag filter 102, and increase of the feed forward quantity is restrained. Thus, generation of engine stop and the like can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention provides a method for determining the feedforward amount based on the throttle opening, when the engine rotational speed is lower than a certain amount with respect to the target engine rotational speed. The present invention relates to a control device for an automatic starting clutch that stops increasing the amount of feedforward when the engine speed is low and the time rate of change of the engine speed is negative.

[Prior Art] FIG. 9 is a block diagram showing the configuration of a conventional belt-driven variable transmission. In FIG. 9, 2 is a belt-driven variable transmission, and 2A is a belt.

The bell) 2A is stretched between a fixed pulley piece 6 on the driving side and a fixed boolean piece 12 on the driven side. The drive-side pulley 4 is mainly composed of a drive-side fixed pulley piece 6 and a drive-side boob movable piece 8.

The driven pulley 10 is mainly composed of a fixed driven pulley piece 12 and a movable driven pulley piece 14 .

The drive side fixed pulley part 6 of the drive side pulley 4 is connected to the rotation shaft 16
The drive-side movable pulley piece 8 is movable in the axial direction of the rotating shaft 16 and is mounted on the rotating shaft 16 so as to be non-rotatable.

Drive side movable pulley piece 8 and driven side movable pulley piece 14
and, respectively, the first. A second housing 18.20 is attached.

This first. The second housing 18.20 allows the first . A second hydraulic chamber 22,24 is formed.

In the second hydraulic chamber 24 of the driven pulley lO, a biasing means 26 made of a spring or the like is provided for biasing the 27th arm housing 20 in the direction of expansion of the second hydraulic chamber 24.

Further, an oil pump 28 is provided on the rotating shaft 16. This oil pump 28 is connected to the first and second hydraulic chambers 2.
1st on 2.24. They are communicated by second oil passages 30 and 32, respectively.

A primary pressure control valve 34 is provided in the middle of the first oil passage Fa30. This primary pressure control valve 34 is a speed change control valve that controls the primary pressure that is the input shaft sheave pressure.

From this primary pressure control valve 34, a line pressure (generally 5 to 25 kg/cd) is supplied to the first oil passage 30 on the oil pump 28 side by a third oil passage 36 at a constant pressure (3 to 4 kg/cnf). The primary pressure control valve 34 is connected to a first three-way solenoid valve 42 for controlling the primary pressure through a fourth oil passage 40 .

In addition, the middle of the second oil passage 32 and the seventh oil passage 5
A fifth oil passage 46 communicates with the middle of the fourth oil passage, and a line pressure control valve 44 is provided between the fifth oil passage 46 and the sixth oil passage 4. This line pressure control valve 44 has a relief valve function to control line pressure.

The line pressure control valve 44 communicates with a second three-way solenoid valve 50 for line pressure control via a sixth oil passage 48.

Further, the seventh oil passage 54 is connected to the clutch pressure control valve 52.
It communicates with the eighth oil passage 56 via. This clutch pressure control valve 52 controls clutch pressure.

The eighth oil passage 56 communicates with a third three-way solenoid valve 58 for clutch pressure control.

The first three-way solenoid valve 42 for clutch pressure control, the second three-way solenoid valve 50 for clutch pressure control, and the third three-way solenoid valve 58 for clutch pressure control each communicate with the ninth oil passage 60. and a primary pressure control valve 34, respectively.
, line pressure control valve 44, and clutch pressure control valve 52.

One end of the seventh oil passage 54 communicates with the second hydraulic chamber 24 .

Furthermore, the clutch pressure control valve 52 communicates with the hydraulic starting clutch 62 through a tenth oil passage 64, and communicates with the pressure sensor 6 through an eleventh oil passage 66.
It is connected to 8.

This pressure sensor 68 can directly control the oil pressure when controlling the clutch pressure in hold and start modes, and contributes to giving a command to set the detected oil pressure as the target clutch pressure.

Furthermore, in the drive mode, the clutch pressure becomes equal to the line pressure, so it contributes to line pressure control.

Furthermore, an input shaft rotation detection gear 70 is provided outside the first housing 18 . A first rotation detector 72 on the human power shaft side is located near the outer circumference of the input shaft rotation detection gear 70.
is provided.

On the other hand, an output shaft rotation detection gear 74 is provided outside the second housing 20. A second rotation detector 76 on the output shaft side is provided near the outer periphery of the output shaft rotation detection gear 74.

Detection signals from the first rotation detector 72 and the second rotation detector 76 are sent to a control unit 82 (ECU) to determine the engine rotation speed and belt ratio.

Further, the hydraulic start clutch 62 is provided with an output transmission gear. A third rotation detector 80 is provided near the outer periphery of the output transmission gear 78 to detect rotation of the final output shaft.

This third rotation detector 80 includes a reduction gear, a differential, a drive machine,
It detects the rotation of the final output shaft, which is directly connected to the tires, and is capable of detecting vehicle speed.

By the second rotation detector 76 and the third rotation detector 80,
It is also possible to detect rotations before and after the hydraulic starting clutch 62, which contributes to detecting the amount of clutch slip.

In addition, the throttle opening of the vehicle's carburetor (not shown) and the
~ The control unit 82 is provided which inputs various conditions such as engine rotation and vehicle speed from the third rotation detector 72, 76, 80, changes the duty rate, and performs gear change control. A first three-way solenoid valve 42 and a constant pressure control valve 38 for pressure control. It is configured to control the opening and closing operations of the second three-way solenoid valve 50 for line pressure control and the third three-way solenoid valve 58 for clutch pressure control, and also to control the pressure sensor 68.

The various signals input to the control section 82 and the functions of the input signals are as follows.

(1) Shift lever position detection signal, this is rR
The line pressure, ratio, and clutch required for each range are controlled by each range signal such as l, rRl, rNJ, rDJ, rLJ, etc.

(2) Carburetor throttle opening detection signal, which detects engine torque from memory input into the program in advance and determines the target ratio or target engine speed.

(3) Carburetor idle position detection signal, which is used to correct the carburetor throttle opening sensor and improve accuracy in control.

(4) Accelerator pedal signal: This detects the driver's intention based on the state of depression of the accelerator pedal, and determines control when driving or starting.

(5) Brake signal: This detects whether or not the brake pedal is depressed,
Determines control direction such as clutch disengagement.

(6) Power mode option signal, which is used as an option to make the performance of the vehicle more sporty (or more economical).

The control unit 82 inputs a detection signal of the vehicle speed NCO, and when the vehicle speed NCO becomes equal to or higher than a predetermined vehicle speed trigger value NCOTR, the control unit 82 changes the speed change control method from oven loop control to closed loop control even in the normal start mode. It changes the

Note that 84 is a piston of the hydraulic starting clutch 62;
6 is an annular spring; 88 is a first pressure coupler; 90
9 is a flixilan plate, 92 is a second pressure plate, 9
4 is an oil pan, 96 is an oil filter, and 69 is an oil temperature sensor for detecting the temperature of the oil in the oil pan 94, the output of which is output to the control section 82.

Next, the operation will be explained. In the belt-driven continuously variable transmission 2, an oil pump 28 located on the rotating shaft 16 operates in accordance with the drive of the rotating shaft 16, and sono oil is absorbed from an oil pan 94 in the transmission control section via an oil filter 96. Ru.

The pressure of this oil pump 28, that is, the line pressure is controlled by a line pressure control valve 44.
If the amount of leakage from the line pressure control valve 44 is large, the line pressure will be low;
Line pressure increases.

Further, the line pressure control valve 44 has a shift control characteristic that performs three-step control to change the line pressure in a full low state, a full over top state, and a fixed ratio state.

The operation of the line pressure control valve 44 is controlled by a dedicated second three-way solenoid valve 50.
This second three-way solenoid valve 50
The line pressure control valve 44 operates following the operation.

The second three-way solenoid valve 50 is controlled at a constant frequency duty rate. In other words, the duty rate of 0% means that the second three-way i
The M1 valve 50 is not operating at all, the output side is connected to the atmosphere, and the output oil pressure is zero.

Also, 100% duty rate means that the second three-way solenoid valve 50
operates, the output side is isolated from the atmosphere side, the maximum output oil pressure is the same as the control pressure, and the output oil pressure is varied depending on the duty rate.

Therefore, the characteristics of the second three-way solenoid valve 50 are almost linear, and it becomes possible to operate the line pressure control valve 44 in an analog manner, and by arbitrarily changing the duty rate of the second three-way solenoid valve 50, the line pressure control valve 44 can be operated in an analog manner. Pressure can be controlled.

The operation of this second three-way solenoid valve 50 is controlled by a control section 82.

The primary pressure for speed change control is controlled by a primary pressure control valve 34, and like the line pressure control valve 44, this primary pressure control valve 34 is also controlled by a dedicated first three-way solenoid valve 42.

This first three-way solenoid valve 42 is used to conduct the primary pressure to the line pressure, or to conduct the primary pressure to the atmospheric side, and to conduct the belt ratio to the full overdrive side or to the atmospheric side by conducting the primary pressure to the line pressure. This causes conduction to occur and the transition to the full low side.

On the other hand, the clutch pressure control valve 52 controls the clutch pressure, and connects it to the line pressure when the maximum clutch pressure is required, and connects it to the atmosphere side when the minimum clutch pressure is required. It is.

This clutch pressure control valve 52 also has a dedicated third three-way solenoid valve 5, similar to the line pressure control valve 44 and the primary pressure control valve 34.
The operation is controlled by 8, and the explanation will be omitted.

Clutch pressure varies within a range from minimum atmospheric pressure (zero) to maximum line pressure. There are four basic patterns for clutch pressure control, which will be described later, and these basic patterns are as follows.

(1) Neutral mode In this mode, when the clutch is completely disengaged at the shift position (NJ or [PJ), the clutch pressure is the lowest pressure (zero).

(2) Hold mode In this mode, the shift position is fDJ, [LJ or rRJ,
When you release the throttle and have no intention of driving, or when you slow down while driving and want to cut off engine torque, the clutch pressure is at a low enough level that the clutch contacts.

(3) Start mode This mode changes the clutch pressure to the engine-generated torque (clutch input torque) that prevents the engine from revving and allows the vehicle to operate smoothly when starting or when attempting to re-engage the clutch after the clutch has been disengaged. It is at an appropriate level.

(4) Drive mode There are four high levels of clutch pressure that are sufficient to withstand engine torque when the clutch is fully engaged and the clutch is fully engaged.

This basic pattern (1) is performed by a dedicated switching valve (not shown) that is linked to the shift operation, and the other basic pattern (1) is
2), (3), and (4) are performed by controlling the duty ratio of the first to third three-way solenoid valves 42, 50, and 58 by the control unit 82.

In particular, in the state (4), the clutch control valve 25 connects the seventh oil passage 54 and the tenth oil passage 64 to create a maximum pressure generation state, and the clutch pressure becomes the same as the line pressure.

In addition, the primary pressure control valve 34, the line pressure control valve 44,
The clutch pressure control valve 52 includes the first to third three-way solenoid valves 42 and 5.
These first to third three-way solenoid valves 42, 50.58 are controlled by the output oil pressure from 0.58, respectively.
The control oil pressure that controls the is a constant oil pressure created by a constant pressure control valve 38.

This control oil pressure is lower than the line pressure, but is a stable and constant pressure.

Further, the control oil pressure is used to stabilize the primary pressure control valve 34, the line pressure control valve 44, and the clutch pressure control valve 52.

Next, electronic control of the heald drive type continuously variable transmission 112 will be explained. This heald drive type continuously variable transmission 2 is hydraulically controlled, and according to commands from the control unit 82, appropriate line pressure for belt protection and torque transmission, primary pressure and clutch for changing the gear ratio are controlled. Clutch pressure for reliable engagement is ensured in each case.

FIG. 4 shows a control section 82 of a conventional automatic starting clutch control device.
FIG. 2 is a block diagram showing the configuration of a feedback system and a feedforward system.

The shift control duty is 0% in the start mode. The line pressure control 11 determines a target line pressure using a target line pressure determining means 111 in accordance with the throttle opening degree θ, and outputs the determined target line pressure to a −th order lag filter 112 . This -order lag filter 112
Then, filter processing is performed to delay the target line pressure by one order, and the result is output to the pressure/duty conversion means 113. This pressure/duty conversion means 113 determines the duty corresponding to the target pressure and outputs the line pressure control duty.

Next, the clutch pressure control duty will be explained. In the clutch control n, the target engine speed determining means 103 determines the target engine speed according to the throttle opening θ,
It passes through the -order lag filter 104, performs -order lag filter processing, and adds it to the subtracter 105.

This subtracter 105 calculates the output of the -order lag filter 104 and the actual engine rotational speed Ne to obtain the deviation and outputs it to the Pl@ control means 106.

This Pr1J control means 106 inputs the output of the subtracter 105, that is, the deviation between the target engine speed and the actual engine speed Ne, performs proportional and integral calculations, and outputs it to the subtracter 107 as a target pressure correction value. .

On the other hand, in the feed forward loop, the forward amount determining means 101 determines a temporary target clutch pressure according to the throttle opening degree θ, and the -th lag filter 102 performs filter processing for the -th lag. and outputs it to the subtracter 107.

This subtracter 107 subtracts the temporary target clutch pressure from the target pressure correction value, corrects the temporary target clutch pressure by the target pressure correction value, and outputs the corrected target clutch pressure to the subtractor 10B.

The subtracter 108 subtracts this target clutch pressure from the actual clutch pressure Pc to obtain a deviation, and this deviation is calculated as PID.
It is output to the control means 109.

With this PID control means 109, after proportional and differential integral calculations,
It is output to the subtracter 110. In this subtracter 110, PI
The output of the D control means 109 is subtracted from the offset duty value, the deviation is taken, and the clutch pressure control duty, which is the manipulated variable, is output.

The characteristics shown in FIG. 5 show the relationship between the throttle opening (θ) and the target engine speed in the target engine speed determining means 103.

The feedforward amount determining means 101 calculates and outputs a clutch pressure that can transmit an engine torque corresponding to a target engine speed determined by the throttle opening θ.

FIG. 7 shows an example of the target engine speed determined by the target engine speed determining means 103 on an engine characteristic diagram, and shows the target engine speed corresponding to the throttle opening and the l corresponding to the speed. Engine torque Ten
I understand.

Feedforward amount determining means 10], based on the relationship shown in FIGS. 7 and 6 (characteristic diagram of clutch oil pressure vs. clutch transmission torque), throttle opening target engine speed - nominal engine torque - required clutch transmission torque - clutch pressure (See the characteristic diagram of throttle opening versus feedforward amount in Figure 8).

[Problem to be solved by the invention]

Changes in engine characteristics due to usage conditions, environment, changes over time and variations in products, actual engine output fluctuations due to operating conditions of auxiliary equipment, light and heavy electrical loads, and changes in clutch oil pressure vs. transmission torque characteristics shown in Figure 6. Due to variations, etc., the amount of feedforward (temporary target crunch pressure)
If the deviation from the feedback loop becomes large, the amount of correction in the feedback loop will be insufficient (because there is an upper limit to the control gain of the feedback loop due to the stability of the feedback loop, there is also a limit to the amount of correction), and there is a delay. Due to a delay in clutch engagement, the engine speed may start to rise.

On the other hand, if the clutch is engaged too early, it may cause the clutch to engage too quickly, causing the engine to sluggish, and in the worst case scenario,
This will cause a so-called engine stall.

This invention was made in order to solve the above-mentioned problems, and without impairing the characteristics of feedforward control that is free from control delay and hunting, it is possible to eliminate sluggish start due to the discrepancy between the appropriate operation amount and the feedforward amount, Another object of the present invention is to provide a control device for an automatic starting clutch that can prevent engine stalling and improve the controllability of the automatic starting clutch.

[Means to solve the problem]

The automatic starting clutch control device according to the present invention has an engine rotation speed lower than a certain amount relative to a target rotation speed,
In addition, a control section is provided that limits the feedforward amount determined according to the throttle opening when the time rate of change of the engine speed is negative.

[For production]

The control unit in this invention determines the feedforward amount according to the throttle opening degree, and the engine speed is lower than the target engine speed by a certain amount, and the time rate of change of the engine speed is negative. To become and,
It acts to stop this increase in the feedforward amount and to suppress the sluggishness in starting due to the discrepancy between the appropriate operation amount and the feedforward amount.

[Embodiments] Hereinafter, embodiments of the automatic starting clutch control device of the present invention will be described based on the drawings. FIG. 1 is a block diagram showing the configuration of the control section in one embodiment. In FIG. 1, the same parts as in FIG. 4 are given the same reference numerals, and the parts different from FIG. State it to the subject.

As is clear from comparing Figure 1 with Figure 4,
In the figure, a limit determining means 114 and a switch 115 are newly added to the configuration of FIG. 4.

That is, the switch 115 is inserted between the feedforward amount determining means 101 and the first-order lag filter 102, and the opening of this switch 115 is controlled by the output of the limit determining means 114.

The input terminal of the limit determining means 114 is connected to the engine rotation speed Ne.
and the output of the subtracter 105 are input.

With this configuration, the feedforward amount determining means 101 inputs the feedforward amount corresponding to the throttle opening θ, that is, the necessary pressure value, to the first-order lag filter 102 via the normally open switch 115, The operation is as already described in the [Prior Art] column of FIG.

On the other hand, the target engine rotation speed corresponding to the throttle opening θ determined by the target engine rotation speed determination means 103 passes through the first-order lag filter 104, and in the subtracter 105,
The deviation is calculated by subtracting from the engine rotation speed Ne.

This deviation is output to the limit determining means 114 and the PI control means 106, and the engine rotational speed Ne is also input to the limit determining means 114.

The limit determining means 114 opens the switch 115 when the deviation is larger than a predetermined amount and the time rate of change (difference in digital processing) of the engine speed Nc becomes negative.

As a result, the feedforward amount is no longer input to the first-order lag filter 102. As a result, the -order lag filter 102 retains the value before the switch 115 was opened. In other words, an increase in the amount of feedforward is suppressed.

Figure 2 shows an example of starting data when the feedforward amount is within an appropriate range, and Figure 2 (b) shows the clutch pressure for the throttle opening in Figure 2 (a). and the broken line is the feedforward portion, as shown in Figure 2 (C
) shows the engine speed, and the broken line is the target engine speed. FIG. 2(d) shows the relationship between time and vehicle speed.

In addition, Fig. 3 shows an example of data for starting when the amount of feedforward is excessive for some reason.
Figure 3(d) shows clutch pressure, engine speed,
Indicates vehicle speed.

It should be noted that the PID control means 109 and the PI control means 106 in FIG. 1 may be of any type as long as they can appropriately realize their respective feedback control, and are of course not essential structural conditions of the present invention.

[Effects of the Invention] As described above, according to the present invention, when the engine speed is a certain amount or more with respect to the target engine speed and the time rate of change of the engine speed is negative, the throttle is opened. Since the increase in the feedforward amount determined according to the amount of operation is suppressed, while taking advantage of the characteristics of feedforward control that there is no control delay or hunting, there is no delay in starting due to the discrepancy between the appropriate operation amount and the feedforward amount. This has the effect of preventing engine stalling and improving the controllability of the automatic start clutch.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the feedback system and feedforward system of the control unit of the automatic starting clutch control device according to an embodiment of the present invention, and Fig. 2 shows that the feedforward amount in the above embodiment is within an appropriate range. FIG. 3 is an explanatory diagram showing an example of data when the feedforward amount is excessive in the same embodiment as above. FIG. A block diagram of the feedback system and the feedforward system. Figure 5 is a characteristic diagram showing the relationship between the throttle angle and target engine speed to explain the feedbank system and feedforward system in Figure 4. Figure 6 is a characteristic diagram showing the relationship between the throttle distance and the target engine speed. Figure 4 is a characteristic diagram showing the relationship between clutch oil pressure and clutch transmission torque to explain the feedback system and feedforward system, and Figure 7 is a characteristic diagram showing the relationship between engine speed and clutch transmission torque to explain the feedback system and feedforward system in Figure 4. A characteristic diagram showing the relationship between engine torque; FIG. 8 is a characteristic diagram showing the relationship between throttle opening and feedforward amount to explain the feedback system and feedforward system in FIG. 4;
FIG. 9 is a block diagram of a conventional belt-driven continuously variable transmission. 2... Belt driven continuously variable transmission, 34... Primary pressure control valve, 3rd... Constant pressure control valve, 42... First three-way solenoid valve, 44... Line pressure control valve, 50 ...
Second three-way solenoid valve, 52... Franch pressure control valve, 58...
...Third three-way solenoid valve, 62...Hydraulic starting clutch, 6
8...Pressure sensor, 69...Oil temperature sensor, 82...
- Control unit, 101... Feedforward amount determining means, 103... Target engine rotation speed determining means, 105,
107°110...Subtractor, 111...Target line pressure determining means, 113...Pressure/duty conversion means,
114...Limit determination means, 115...Switch. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] a primary pressure control valve that controls the primary pressure of the hydraulic starting clutch; a line pressure control valve that controls the line pressure of the hydraulic starting clutch; a clutch pressure control valve that controls the clutch pressure of the hydraulic starting clutch; a first to third three-way solenoid valve that individually controls the control valve, the line pressure control valve, and the clutch pressure control valve; and a second three-way solenoid valve that controls the first to third three-way solenoid valves and the second three-way solenoid valve. On the other hand, a target line pressure is determined according to the throttle opening degree, and control is performed based on the line pressure control duty, and feedforward control of the engine speed is performed on the third three-way solenoid valve, and the engine speed is controlled based on the target line pressure. and a control unit that suppresses the feedforward amount and calculates the clutch pressure control duty when the time rate of change of the engine speed is negative at a predetermined amount or less with respect to the target engine speed. Device.