JPH0667695B2 - Control device for automatic starting clutch - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic starting clutch, and more particularly to a control device for an automatic starting clutch that can arbitrarily control a transmission torque capacity.

2. Description of the Related Art Conventional technology and its problems Conventionally, as an automatic starting clutch control device capable of arbitrarily controlling a transmission torque capacity by an actuator, for example, one disclosed in Japanese Patent Laid-Open No. 175828 / SHO is known. This control device supplies to the clutch a hydraulic pressure that rises corresponding to the engine speed only when the vehicle starts, and supplies a high hydraulic pressure that completely engages the clutch when the vehicle is running after the start of the vehicle, even in the low engine speed range. The vehicle is driven with the clutch engaged.

In the control device for the automatic starting clutch, a high hydraulic pressure for completely engaging the starting clutch is introduced during running as described above, and if the vehicle is gradually decelerated from this state, the engine immediately before the engine stall is normally considered in consideration of fuel consumption. The starting clutch is held in the engaged state until the rotation speed is reduced. However, in such control, when the vehicle is suddenly braked and stopped, the disconnection of the starting clutch may be delayed and the engine may stall. The reason is that the transmission torque capacity when the starting clutch is engaged is designed with a certain margin so that slip does not occur even at the maximum engine torque,
This is because there will be a time delay even if an attempt is made to suddenly disconnect from this completely engaged state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems,
It is an object of the present invention to provide a control device for an automatic starting clutch that speeds up the disconnection of the starting clutch at the time of sudden stop.

In order to achieve the above object, the present invention, as shown in FIG. 7, is an automatic starting clutch control device capable of arbitrarily controlling a transmission torque capacity by an actuator, and a means for detecting a throttle opening and a throttle opening. Means for determining whether the opening is fully closed or in the vicinity thereof, means for detecting the engine speed, means for detecting a complete engagement state based on the speeds before and after the starting clutch, and the throttle opening determining means. Signals are input from the engine speed detection means and the clutch engagement detection means, and a clutch control means for controlling the actuator based on these signals is provided, and the throttle opening degree determination means is provided when the clutch engagement detection means detects complete engagement. When the signal output indicates that the throttle opening is fully closed or in the vicinity thereof, the clutch control means described above corresponds to the engine speed. The actuator is controlled so that the transmission torque capacity is slightly higher than the engine absorption torque.

That is, the torque that acts on the starting clutch during normal running, especially when the throttle opening is fully closed or in the vicinity thereof, has the largest reverse drive torque during engine braking, and this reverse drive torque is much higher than the maximum torque of the engine. small.
Therefore, when the starting clutch is controlled so that the transmission torque capacity is slightly larger than the reverse drive torque when the throttle opening is fully closed or in the vicinity thereof, the engaging force of the starting clutch can be lowered to a necessary minimum level, The starting clutch can be instantly disengaged even when sudden braking is applied to stop.

Description of Embodiments FIG. 1 shows a V equipped with an automatic starting clutch according to the present invention.
A belt type continuously variable transmission is shown, which includes a crankshaft 2 of an engine 1.
Is connected to the input shaft 4 via the damper mechanism 3. An external gear 5 is fixed to an end portion of the input shaft 4, and the external gear 5 meshes with an internal gear 6 fixed to a drive shaft 11 of the continuously variable transmission 10, so that the power of the input shaft 4 is transmitted. Drive shaft 11 with deceleration
Have been communicated to.

The continuously variable transmission 10 includes a drive pulley 12 provided on a drive shaft 11,
The driven shaft 13 is composed of a driven pulley 14 and a V belt 15 wound between the pulleys. Drive pulley 12
Has a fixed sheave 12a and a movable sheave 12b, and a torque cam device 16 and a compression spring 17 are provided behind the movable sheave 12b. The torque cam device 16 generates a thrust force proportional to the input torque, and the compression spring 17 generates V
The belt 15 generates an initial thrust that does not slacken, and these thrusts apply the belt tension required for torque transmission to the V-belt 15. On the other hand, the driven pulley 14 is also the drive pulley 12
Similarly, it has a fixed sheave 14a and a movable sheave 14b, and behind the movable sheave 14b is a hydraulic chamber 18 for gear ratio control.
Is provided. The hydraulic pressure to the hydraulic chamber 18 is controlled by a pulley control valve 43 described later.

A hollow shaft 19 is rotatably supported on the outer periphery of the driven shaft 13, and the slave coaxial 13 and the hollow shaft 19 are connected and disconnected by an automatic starting clutch 20 composed of a wet multi-plate clutch. The hydraulic pressure to the automatic start clutch 20 is controlled by a start control valve 45 described later. A forward gear 21 and a reverse gear 22 are rotatably supported on the hollow shaft 19, and a dog clutch for forward / reverse switching is provided.
By means of 23, either the forward gear 21 or the reverse gear 22 is connected to the hollow shaft 19. A reverse drive idler gear 25 that meshes with the reverse drive gear 22 and another reverse drive idler gear 26 are fixed to the reverse drive idler shaft 24. The counter shaft 27 has a counter gear 28 that meshes with the forward gear 21 and the reverse idler gear 26 at the same time.
The final reduction gear 29 is fixed, and the final reduction gear 29 meshes with a ring gear 31 of the differential device 30 to transmit power to the output shaft 32.

The pressure regulating valve 40 regulates the hydraulic pressure discharged from the oil sump 41 by the oil pump 42 and outputs it as a line pressure to the pulley control valve 43 and the start control valve 45. The pulley control valve 43 and the start control valve 45 actuate the solenoids 44 and 46 by the duty control signal output from the electronic control unit 60 to control the line pressure to control the hydraulic chamber 18 and the start clutch 20 of the driven pulley 14, respectively. The control oil pressure is output to.

Specific structures of the control valves 43 and 45 are, for example, a combination of a spool valve 50 and a solenoid valve 52 as shown in FIG.
As shown in the figure, the ball-shaped valve body 53 may selectively open and close the input port 54 and the drain port 55 to output the control hydraulic pressure to the output port 56, which may be a single 3-port solenoid valve. For example, when the control valves 43 and 45 are composed of the spool valve 50 and the solenoid valve 52 as shown in FIG. 2, if the duty ratio output from the electronic control unit 60 to the solenoid valve 52 is D, the spool valve The output hydraulic pressure P _{OUT of} 50 is given by the following equation.

_{P OUT × A 1 = P L} × D × A 2 + F ... (1) In the above formula, A _1, A ₂ are lands 5 of the spool valve 50, respectively
The pressure receiving areas of 0a and 50b, P _L is the line pressure, and F is the spring load of the spring 51.

Further, when the control valves 43, 45 are composed of a single solenoid valve as shown in FIG. 3, the output hydraulic pressure P _OUT is given by the following equation.

P _OUT = P _L × D (2) In formulas (1) and (2), A ₁ , A ₂ , P _L and F are constant values, so the duty ratio D and the output hydraulic pressure P _OUT are proportional. To do.
On the other hand, since the gear ratio of the continuously variable transmission 10 and the transmission torque capacity of the starting clutch 20 can be controlled by the output hydraulic pressure P _OUT , the duty ratio D eventually determines the gear ratio of the continuously variable transmission 10 and the transmission torque capacity of the starting clutch 20. It can be controlled freely.

FIG. 4 shows a block diagram of the electronic control unit 60, in which 61 is a block diagram.
Is a sensor for detecting the engine speed (may be the speed of the input shaft 4), 62 is a sensor for detecting the vehicle speed, and 63 is the driven shaft 13
A sensor for detecting the number of revolutions (which may be the input number of revolutions of the starting clutch 20 or the number of revolutions of the driven pulley 14), 64 is P, R, N,
A sensor for detecting each shift position of D and L, and a sensor 65 for detecting a throttle opening, the signals of the sensors 61 to 64 are input to an input interface 66, and the signal of the sensor 65 is an A / D converter 67. Is converted into a digital signal by. 68 is a central processing unit (CPU), 69 is a pulley control solenoid 4
4 and a read-on memory (RO that stores programs and various data for controlling the start control solenoid 46)
M), 70 is a random access memory (RAM) for temporarily storing the signals and parameters sent from each sensor, 71 is an output interface, and CPU 68, ROM 69, RA
M70, output interface 71, input interface 6
The 6 and A / D converter 67 are interconnected by a bus 72. The output of the output interface 71 is output to the pulley control solenoid 44 and the start control solenoid 46 as a duty control signal via the output driver 73.

In the control device for the automatic starting clutch having the above structure, the starting clutch 20 is completely engaged during traveling, and the transmission torque capacity thereof is much larger than the torque actually transmitted through the starting clutch 20. Especially, when the vehicle is traveling at or near the throttle opening fully closed and at a high speed ratio, the difference between the transmission torque capacity and the actual transmission torque is even greater, which means that the starting clutch should be engaged with more force than necessary. This means that the breaking performance during sudden braking is impaired. Therefore, the present invention provides a starting clutch 20 when the throttle opening is fully closed or in the vicinity thereof.
The transmission torque capacity of is reduced to such an extent that slip does not occur, and the starting clutch 20 disengagement performance is improved. Therefore, in the present invention, the starting clutch 20 is controlled so that the transmission torque capacity is slightly higher than the engine absorption torque at the time of engine reverse driving, which is the maximum torque at or near the throttle opening fully closed.

The transmission torque capacity T of the starting clutch 10 in this case is calculated by the following equation.

In (3), Nin engine speed, N _OUT is driven shaft rotational speed (clutch input rotational speed), A, B, C are respectively constant. The constants A, B, and C are determined according to the engine absorption torque characteristics during engine braking, but the general engine absorption torque linearly increases as the engine speed increases, as shown in FIG.

As is apparent from the equation (3), the transmission torque capacity T when the throttle opening is fully closed is determined by the gear ratio (Nin / N) of the continuously variable transmission 10.
_OUT ) and engine speed Nin. For example, the transmission torque capacity T is adjusted to the lowest when the vehicle is running in the high speed ratio range where the gear ratio is small and the low engine speed range. Therefore, even if sudden braking is applied from this state, the starting clutch 20 can be instantaneously disengaged at the engine speed immediately before the engine stall.

In addition, using a hydraulic clutch as the starting clutch 20,
When the start control valve 45 for supplying the clutch hydraulic pressure is configured as shown in FIGS. 2 and 3, the transmission torque capacity (clutch hydraulic pressure) is proportional to the duty ratio. Can be replaced with

In the equation (4), D is the duty ratio input to the start control solenoid 46, and a, b, and c are constants. If the transmission torque capacity is replaced by the duty ratio as in the equation (4), the transmission torque capacity can be arbitrarily controlled only by the electric signal, so that the control becomes extremely simple.

Next, an example of the operation of the control device for the automatic starting clutch will be described with reference to FIG.

When started, first the operation signals from various sensors, that is, the engine rotational speed Nin, the clutch input rotational speed N _OUT, the vehicle speed V, the
The throttle opening θ etc. are detected (80). Among these operation signals, the throttle opening θ and the small value θ ₀ (for example, θ ₀
= 81%) (81), and if θ ≤ θ ₀ , it means that the throttle opening is fully closed or in the vicinity thereof. Value (| N
A value obtained by dividing _OUT −V |) by the clutch input speed N _OUT is compared with a constant value ε (eg, ε = 0.1) (82). If the starting clutch 20 is completely engaged and is in a running state, Therefore, in this case, the duty ratio D for generating a transmission torque capacity slightly higher than the engine absorption torque is subsequently calculated from the equation (4) (83). Then, the duty ratio D calculated above is output to the start control solenoid 46 (8
4), end the control.

The starting clutch of the present invention is not limited to the wet clutch, and a dry clutch or an electromagnetic clutch can be used as long as the clutch can control the transmission torque capacity arbitrarily.
Further, in the embodiment, the solenoid for duty control is used as the actuator and the transmission torque capacity is controlled by the duty ratio, but the invention is not limited to this.

Further, the starting clutch may be arranged not only on the downstream side of the continuously variable transmission but also on the upstream side. In this case, the factor of the gear ratio in the equation (3) may be deleted. The control of the present invention is more effective when the starting clutch is provided on the downstream side of the continuously variable transmission. That is, if the start clutch is provided on the downstream side of the continuously variable transmission, the pulley rotates even during neutral, so there is an advantage that the gear can be easily shifted to the low speed ratio side even when the gear ratio is smaller than the minimum speed ratio when the vehicle is stopped. However, at the low speed ratio, the engine torque is doubled and transmitted to the starting clutch, so that the transmission torque capacity of the starting clutch must be increased.
Therefore, the excess transmission torque capacity of the starting clutch at a high speed ratio becomes extremely large, and there is a high possibility that the breaking performance at the time of sudden stop will be hindered. However, the transmission torque capacity control of the present invention can solve such a problem.

As is apparent from the above description, according to the present invention, by controlling the transmission torque capacity of the starting clutch at or near the throttle opening fully closed to a value slightly higher than the engine absorption torque, the starting clutch It is possible to reduce the fastening force to the minimum necessary level without causing slippage. As a result, even when the vehicle is suddenly braked and stopped, the starting clutch can be instantly disengaged and engine stalling can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of a V-belt type continuously variable transmission to which the present invention is applied, and FIGS. 2 and 3 are specific structural views of a control valve.
FIG. 4 is a block diagram of the electronic control unit, FIG. 5 is an engine absorption torque characteristic diagram, FIG. 6 is a flow chart diagram of an example of the method of the present invention, and FIG. 7 is a block diagram showing components of the present invention. 1 ... Engine, 4 ... Input shaft, 10 ... Continuously variable transmission,
20 …… Automatic start clutch, 32 …… Output shaft, 45 …… Start control valve, 46 …… Start control solenoid, 60 …… Electronic control unit, 61 …… Engine speed sensor, 62 …… Vehicle speed sensor,
63 …… Driven shaft speed sensor, 65 …… Throttle opening sensor.

Claims (1)

[Claims] 1. A control device for an automatic starting clutch capable of arbitrarily controlling a transmission torque capacity by an actuator,
A means for detecting the throttle opening, a means for determining whether the throttle opening is at or near the fully closed position, a means for detecting the engine speed, and a complete engagement state by the speeds before and after the starting clutch. Means, a clutch control means for inputting signals from the throttle opening degree determining means, the engine speed detecting means, and the clutch engagement detecting means and controlling the actuator based on these signals. At the time of engagement detection, when the throttle opening discriminating means outputs a signal of the throttle opening fully closed or the vicinity thereof, the clutch control means makes the transmission torque capacity slightly higher than the engine absorption torque corresponding to the engine speed. An automatic starting clutch control device characterized by controlling an actuator.