JPH084796A - Clutch control device - Google Patents

Abstract

(57) [Abstract] [Purpose] Fail-safe that prevents slipping of the clutch and enables accurate synchronization control even when an abnormality such as a failure occurs in the signal system of the rotation speed detector of the clutch output shaft. Provided is a clutch control device for a continuously variable transmission equipped with a mechanism. [Arrangement] An engine speed detector, a clutch output shaft speed detector, an accelerator pedal on / off detection device,
The throttle opening detector is provided, and when the accelerator pedal on / off detection device indicates the accelerator on state when the shift position is in the travelable position, the throttle opening is detected when an abnormality in the clutch output speed is detected. The engine speed is estimated using the degree as a parameter. When the engine speed is higher than the estimated value, the clutch is directly connected, and when the engine speed is lower than the estimated value, the clutch engagement control is performed based on the throttle opening and the engine speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle clutch control device.

[0002]

2. Description of the Related Art In a conventional belt type continuously variable transmission, when a clutch is engaged, control is performed to determine the synchronization based on the rotational speed of the input / output shaft of the clutch to bring the clutch into a directly connected state.

More specifically, in the clutch control device, the clutch transmission torque is, as shown in FIG. 4, an output signal from the engine speed detector which is an output signal from the engine speed detector and an output signal from the throttle opening detector. The clutch pressure is controlled so that it is determined by a function of a certain throttle opening, and the engine speed output from the engine speed detector and the clutch output shaft speed output from the clutch output shaft speed detector. When they are equal (that is, in the synchronous state), the clutch control pressure is increased to the maximum pressure and held at the position where the clutch transmission torque is maximum, as shown by the dotted line in FIG. 5-2029
49).

[0004]

However, in such a clutch control device, in the unlikely event that an abnormality such as disconnection or short circuit of the signal system of the clutch output shaft rotation detector occurs,
When the clutch output shaft speed is not input, it is considered that the clutch output shaft is not rotating.For example, when the clutch output shaft speed is zero, the engine speed and the clutch output shaft speed cannot be equal, Therefore, the synchronous control of the clutch becomes impossible.

Under the condition that the rotation speeds of the input shaft and the output shaft of the clutch cannot be determined, for example, when the slip ratio of the clutch is 95%, the clutch control pressure is increased to the maximum pressure to maximize the clutch transmission torque. When the vehicle continues to run without holding the clutch in the slipping state, the clutch plate burns and the clutch plate is welded, and the clutch cannot be released.

Therefore, the present invention solves the above problems and provides a clutch control device for a continuously variable transmission that determines the synchronization between the engine speed and the clutch output shaft speed to control the engagement of the clutch. Provided is a clutch control device equipped with a fail-safe mechanism that prevents slipping of the clutch and enables accurate synchronous control even when an abnormality such as a failure occurs in the signal system of the output shaft rotation speed detector. The purpose is to

[0007]

In order to achieve the above object, the present invention provides a clutch control device for a continuously variable transmission, which is connected to an engine via a clutch, and includes a sensor for detecting at least the engine speed. It is equipped with a sensor that detects the number of revolutions of the clutch output, an accelerator pedal on / off detector, and a throttle opening detector. When the shift position is in the travelable position, the accelerator pedal on / off detector is the accelerator pedal. Provided is a clutch control device characterized in that when an abnormality in the clutch output speed is detected when the on state is indicated, the engine speed is estimated using the throttle opening as a parameter and the clutch engagement control is performed. .

Further, in the clutch control device of the present invention, when the abnormality in the clutch output speed is detected, the engine speed from the sensor for detecting the engine speed is lower than the engine speed estimated from the throttle opening. If it is too large, control to connect the clutch directly.

Further, in the clutch control device of the present invention, when the abnormality in the clutch output speed is detected, the engine speed from the sensor for detecting the engine speed is equal to or lower than the engine speed estimated from the throttle opening. When
The clutch engagement control is performed based on the throttle opening and the engine speed.

[0010]

According to the clutch control device of the present invention having the above-described structure, when the abnormality is detected in the signal system of the rotation speed detector of the clutch output shaft when the accelerator is on, the throttle opening which is the output signal of the throttle opening detector is detected. The engine speed at the time of synchronization is estimated with reference to a predetermined map (a table or a function showing the correspondence between the throttle opening and the engine speed at the time of synchronization) based on the degree of rotation, and this estimated value and the engine speed detector. If the actual engine speed is higher than the estimated value, the clutch pressure is controlled to maximize the clutch transmission torque and the clutch is directly connected. It is possible to prevent the clutch from slipping, which improves durability.

[0011]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, reference numeral 1 on the left side of the drawing represents a skeleton diagram of a transmission device of a continuously variable transmission for transmitting engine power to drive wheels (not shown), and a control block on the right side of the drawing is a hydraulic control circuit of the continuously variable transmission. It represents.

The transmission device 1 includes an input shaft 2, which is connected to an output shaft of an engine via a flywheel damper, a starting clutch 3 including a multi-plate clutch 3a and a multi-plate brake 3b, and a clutch 3. A drive pulley (driving pulley) 4 to which the torque of the input shaft 2 is transmitted, and a differential gear 6 that decelerates the torque of a driven pulley (driven pulley) 5 and transmits the decelerated torque to the axle.

Further, the input shaft 2 is provided with a rotation sensor 11 for detecting the number of revolutions of the engine, and the drive pulley 4 and the driven pulley 5 are provided with rotation sensors 12, 13 for detecting their respective revolutions. A detector 14 for detecting the on / off state of the accelerator, a sensor 15 for detecting the throttle opening, and a shift position detector 16 for identifying the shift position are provided, and the outputs of these sensors are input to the control circuit 20. . The rotation speed of the output shaft of the clutch 3 is detected by the rotation sensor 12 of the drive pulley 4, and the vehicle speed is the rotation speed of the driven pulley 5 detected by the rotation sensor 13 and the known differential ratio and wheel diameter. It is calculated from The vehicle speed can also be calculated by a vehicle speed sensor that detects the rotation speed of a general wheel.

Next, referring to FIG. 1, the hydraulic control circuit will be described. The pressure oil discharged from the oil pump 21 passes through the reduction valve 23 and the clutch control valve 2
5 is input to the input port of the clutch control valve 25, the spool position of the clutch control valve 25 is moved by the control pressure from the solenoid valve SOL3, and the clutch hydraulic pressure is output from the oil passage L3 to the starting clutch 3 via the shift valve 26. Do. The solenoid valve SOL3 is a normally open linear solenoid valve, and is controlled by a signal from the control circuit 20.

The shift valve 26 has a shift position (L,
2, D, N, R, P), the spool position is changed to connect the oil passage corresponding to the shift position, and the pressure oil from the oil passage L3 from the clutch control valve 25 is transferred to the multi-plate clutch 3a or It acts on the hydraulic servo of the multi-plate brake 3b.

Pressure oil is supplied to the solenoid valve SOL1 from the reduction valve 23, and the shift control valve 24 composed of a spool valve is connected to the solenoid valve SOL1.
The hydraulic pressure output to the drive pulley 4 is adjusted by the control pressure from. The solenoid valve SOL1 is a normally open linear solenoid valve, and is controlled by a signal from the control circuit 20. More specifically, the control circuit 20 supplies a control signal to the solenoid valve SOL1 with the vehicle speed and the throttle opening as parameters, adjusts the hydraulic pressure output to the drive pulley 4, and changes the pulley width to change the gear ratio. Control to achieve desired fuel economy and acceleration performance.

Pressure oil is supplied from the reduction valve 23 to the solenoid valve SOL2, and the regulator valve 22 for inputting the line pressure adjusts the hydraulic pressure output to the driven pulley 5 by the control pressure from the solenoid valve SOL2. The solenoid valve SOL2 is a normally closed linear solenoid valve, and has a control circuit 20.
Controlled by the signal from. More specifically, the control circuit 20 obtains the pressing force of the pulley required to prevent belt slip from the map corresponding to the torque and the gear ratio, supplies a control signal to the solenoid valve SOL2, and drives the driven pulley 5 Control the hydraulic pressure output to.

The starting clutch 3 includes a clutch control valve 25.
When the multi-plate clutch 3a is engaged by the clutch pressure from the sun gear Sa and the carrier C that rotate integrally with the input shaft 2.
a is directly connected, whereby the torque of the input shaft 2 is transmitted to the drive pulley 4 directly connected to the carrier Ca at a speed reduction ratio of 1, and acts as a forward drive clutch.

When the multi-plate brake 3b is engaged by the clutch pressure from the clutch control valve 25, the ring gear Li
Is fixed to the brake housing, whereby the torque of the input shaft 2 is transmitted from the sun gear Sa to the planetary pinion, and the carrier Ca is reversed at a predetermined reduction ratio, which acts as a reverse drive clutch.

In the N (neutral) range and the P (parking) range, both the clutch 3a and the brake 3b are released, and the engine torque is the drive pulley 4
Not transmitted to.

FIG. 2 is a sectional view showing the mechanism of the transmission device 1 of FIG. The hydraulic pressure of the forward clutch 3a is determined by the through hole 10
By introducing a and 10b into the cylinders 8a and 8b as oil passages, the hydraulic pressure is increased at the time of engagement to cause the pistons 9a and 9b to slide, thereby engaging a plurality of alternately arranged friction members and plates. The torque from the engine is transmitted to the drive pulley 4 via the starting clutch 3 (multi-plate clutch 3a or multi-plate brake 3b). The transmission torque of the starting clutch 3 is determined by the pressing force of the pistons 9a and 9b.

Further, in FIG. 2, the pistons 4b, 5b are
Presses the movable portions of the drive pulley 4 and the driven pulley 5 by sliding in the cylinders 4a and 5a in the axial direction, and variably controls the pulley widths 4c and 5c that determine the diameters of the respective belts. The oil pressure P1 of the drive pulley 4 is the oil passage L3.
Is introduced into the cylinder 4a of the two chambers through the piston 4b
Slides and is set to a predetermined value. The hydraulic pressure P2 of the driven pulley 5 is introduced into the cylinder 5a through the oil passage L4,
The piston 5b slides and is set to a predetermined value. The V-belts (4d, 5d) are engaged with the drive pulley 4 and the driven pulley 5 to transmit the driving force between them, and the V-shaped belt side portion is provided in accordance with the variation of each pulley groove width. The engagement position with respect to the pulley groove is changed, and the drive is transmitted at a gear ratio corresponding to the drive pulley diameter and the driven pulley diameter.

In order to minimize the drive pulley diameter (the pulley groove width 4C is the maximum), the control current supplied to the solenoid valve SOL1 which is a normally open linear solenoid valve is set to the minimum (that is, OFF) and the cylinder 4a is controlled. The output drive pulley pressure P1 is minimized, and the movable portion of the drive pulley 4 and the piston 4b are moved rightward in the drawing to minimize the pulley diameter.

Further, in order to maximize the drive pulley diameter (the pulley groove width 4C is the minimum), the control current of the solenoid valve SOL1 which is a normally open linear solenoid valve is maximized (that is, turned on) and output to the cylinder 4a. The drive pulley pressure P1 is maximized, and the movable portion of the drive pulley 4 and the piston 4b are moved leftward in the figure to maximize the pulley diameter.

On the other hand, in order to minimize the driven pulley diameter (the pulley groove width 4C is maximum), the control current of the solenoid valve SOL2, which is a normally closed linear solenoid valve, is maximized (that is, turned on) and output to the cylinder 5a. The drive pulley pressure P2 is minimized, and the movable portion of the driven pulley 5 and the piston 5b are moved leftward in the drawing to minimize the pulley diameter.

Further, in order to maximize the driven pulley diameter (the pulley groove width 4C is the minimum), the control current of the solenoid valve SOL2 which is a normally closed linear solenoid valve is minimized (that is, turned off) and output to the cylinder 5a. The driven pulley pressure P2 is maximized, and the movable portion of the driven pulley 5 and the piston 5b are moved rightward in the figure to maximize the pulley diameter.

Therefore, when the gear ratio is set to the lowest side, the drive pulley pressure P1 becomes the minimum pressure and the driven pulley pressure P2 becomes the maximum pressure. When the gear ratio is set to the highest side, the drive pulley pressure P1 becomes the maximum pressure,
The driven pulley pressure P2 becomes the minimum pressure. The solenoid valves SOL1 and SOL2 are off.

The minimum and maximum pressures of the drive pulley pressure P1 or the driven pulley pressure P2 are naturally different depending on the design of the continuously variable transmission, and the vehicle speed v, the throttle opening Θ, the torque T, etc. are traveled. It is also controlled by the state.

Next, the operation of the clutch control device according to the present invention will be described with reference to the flowchart of FIG. The process shown in FIG. 3 corresponds to the clutch control according to the subject of the present invention in the control of the continuously variable transmission by the ECU, and is represented as a subroutine of a main routine (not shown) that controls the entire control. ing.

In the clutch control process, first, it is determined whether or not the range is set to the runnable state based on the detection signal from the shift position detector (step 10).
1). If the range is not in a runnable state, the process directly returns to the main routine.

When the range is in a travelable position such as the D range, it is determined whether or not the accelerator is on by a signal from the accelerator on / off state detector 14 (step 1).
02).

When the accelerator is on, it is determined whether or not an abnormality is detected in the sensor 12 that detects the rotational speed NO of the output shaft of the clutch 3, that is, the rotational speed NO of the drive pulley 4 (step 103). It is determined to be abnormal when, for example, a disconnection or short circuit of the signal system of the rotation sensor 12 is detected, or when the rotation speed of the drive pulley 4 is not input and is zero.

When an abnormality in the signal system of the sensor 12 is detected, the engine speed at the time of synchronization is estimated as a function of the throttle opening Θ output from the sensor 15 for detecting the throttle opening. (Θ) and the actual engine speed Ne output from the engine speed sensor 11
And are compared (step 104). It should be noted that the estimated engine speed f (Θ) is obtained by referring to a corresponding map of the throttle opening value Θ and the predicted value of the engine speed that is likely to be synchronized with this value Θ.

When the actual engine speed Ne is larger than the estimated value f (Θ) of the engine speed, the engine speed is assumed to be in the synchronous state and the clutch 3 is directly connected (step 105). That is, the control current of the solenoid valve SOL3 is maximized in order to maximize the clutch control pressure from the clutch control valve 25 so as to maximize the transmission torque of the clutch.

On the other hand, the actual engine speed Ne
Is smaller than or equal to the estimated value f (Θ) of the engine speed, it is not judged to be in the synchronous state, the transmission torque of the clutch is not immediately increased to the maximum, and the line shown in FIG. According to the figure, the transmission torque of the clutch is controlled as a function of the throttle opening and the engine speed (step 106). That is, the control current is supplied from the control circuit 20 to the solenoid valve SOL3 as a function of the throttle opening Θ and the engine speed Ne.

Next, at step 102, when the accelerator is off, the control current supplied to the solenoid valve SOL3 is minimized to minimize the clutch control pressure from the clutch control valve 25, thereby releasing the clutch 3 (step 107).

In step 103, the sensor 1
When no abnormality is detected in the signal system of No. 2 (normal time), it is determined whether the rotational speeds of the input shaft and the output shaft of the clutch, that is, the engine rotational speed Ne and the rotational speed NO of the drive pulley 4 are equal, When these are equal to each other, the control current of the solenoid valve SOL3 is maximized and the clutch control pressure from the clutch control valve 25 is maximized to directly connect the clutch (step 108).

If the engine speed Ne does not match the engine speed NO of the drive pulley 4 in the comparison of step 108, the transmission torque of the clutch is set to the throttle opening and the engine speed according to the diagram shown in FIG. 4, for example. (Step 106). That is, the control current is supplied to the solenoid valve SOL3 as a function of the throttle opening Θ and the engine speed Ne (step 106).

The steps 108 and 109 relate to clutch control during normal operation and are not directly related to the subject of the present invention, but are described for the purpose of clearly showing the overall control.

Further, in the processing of step 107 which is performed when the range is in the travelable position and the accelerator is in the off state, the clutch 3 is immediately conditioned on the condition that the accelerator is off.
Without releasing, for example, Japanese Patent Laid-Open No. 5-202949
As disclosed in the publication, when the vehicle speed is below a first set value, the clutch pressure is controlled as a function of the engine speed and the transmission torque of the clutch, and when the vehicle speed is below a second set value, Of course, the clutch pressure may be controlled so that the clutch transmission torque becomes substantially zero.

In this embodiment, a map for estimating the engine speed that is expected to be in synchronization based on the throttle opening when the rotation speed of the clutch output shaft cannot be obtained is obtained by, for example, an experiment. In addition to the above-described data, the relationship between the engine speed and the throttle opening at the time of synchronization during normal operation may be learned and stored, and this may be configured as a map.

[0043]

As described above, according to the clutch control apparatus of the present invention, when the rotation speed of the clutch output shaft cannot be obtained when an abnormality occurs in the signal system of the rotation speed detector of the clutch output shaft. Also estimates the engine speed that is expected to be in synchronization based on the throttle opening and controls the clutch engagement to prevent clutch slippage, thus ensuring vehicle safety and durability. It raises to. According to the present invention, the estimated value of the engine speed expected to be in the synchronous state is compared with the measured value of the engine speed output from the engine rotation sensor, and the actual engine speed is estimated. When it is larger, the clutch pressure is controlled so that the transmission torque of the clutch is maximized, and the clutch is directly connected.
Even if the rotation speed of the clutch output shaft cannot be obtained, it is possible to determine the clutch synchronization, reliably avoid the slip of the clutch, and particularly enhance the safety and durability of the vehicle.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a system according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a transmission device for a continuously variable transmission according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a control process of the clutch control device of the present invention.

FIG. 4 shows an example of a conventional clutch control method (Japanese Patent Application Laid-Open No. Hei 5-
FIG.

[Explanation of symbols]

 1 Transmission device 2 Input shaft 3 Clutch 3a Forward clutch (multi-disc clutch) 3b Reverse clutch (multi-disc brake) 4 Drive pulley 4a Cylinder 4b Piston 4c Pulley width 5 Driven pulley 5a Cylinder 5b Piston 5c Pulley width 6 Differential gear 7 Flywheel damper 8a, 8b Cylinder 9a, 9b Piston 10 Through hole 11 Engine rotation sensor 12 Drive pulley rotation sensor 13 Driven pulley rotation sensor 14 Accelerator on / off detector 15 Throttle opening sensor 16 Shift position detector 17 Throttle 18 Engine 20 Control Circuit 21 Oil Pump 22 Regulator Valve 23 Reduction Valve 24 Shift Control Valve 25 Clutch Control Valve 26 Shift Valve SOL1, SOL2, SOL Solenoid valves L1, L2, L3, L4 oil passage Sa sun Ca carrier Li ring gear

Claims (3)

[Claims] 1. A clutch control device for a continuously variable transmission coupled to an engine via a clutch, comprising at least an engine speed detector, a clutch output shaft speed detector, and an accelerator pedal on / off detector. ,
A throttle opening detector, and detects an abnormality in the clutch output shaft rotation speed detector when the accelerator pedal on / off detector indicates an accelerator on state when the shift position is in the travelable position. In this case, the clutch control device estimates the engine speed at the time of synchronization based on the throttle opening, which is the output signal of the throttle opening detector, and performs clutch engagement control. 2. When an abnormality of the clutch output shaft speed detector is detected, when the engine speed from the engine speed detector is higher than the engine speed estimated from the throttle opening, The clutch control device according to claim 1, wherein the clutch is controlled so as to be directly connected. 3. When the abnormality of the clutch output shaft speed detector is detected, when the engine speed from the engine speed detector is equal to or lower than the engine speed estimated from the throttle opening, the throttle is opened. The clutch control device according to claim 1 or 2, wherein engagement of the clutch is controlled based on an opening degree and an engine speed.