JP2006312974A - Controller for lock-up clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a lock-up clutch which improves fuel economy at the time of low speed running by which lock-up vibration is caused while preventing the lock-up vibration. <P>SOLUTION: The controller for a lock-up clutch has a control portion which compares the vibration level difference between the vibrations of a suspension mounting part and a car body with a preset setting value, and operates the lock-up clutch if a vehicle runs in the state that an occupant hardly senses the lock-up vibration and does not operates the lock-up clutch if the vehicle runs in the state that the occupant easily senses the lock-up vibration. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for a lockup clutch.

  The lock-up clutch is a friction clutch provided in almost all torque converters. For example, the lock-up clutch is operated when the vehicle speed and the engine load (engine speed) reach preset values. The input side and the output side are mechanically connected. When this lock-up clutch is operated, power loss due to slip (torque slip) of a torque converter that transmits engine torque via fluid is avoided, and transmission efficiency of engine torque is improved.

  However, in the above-described conventional lockup clutch control device, when the lockup clutch is operated, the torque fluctuation of the engine is transmitted to the automatic transmission without being absorbed and alleviated by the torque converter. Therefore, in the low speed and low rotation range, there is a problem that the lockup vibration, that is, the vehicle body vibration such as the top throw vibration and the rattling vibration, and the booming noise are generated, so that the full lockup cannot be performed.

  In order to solve such a problem, for example, in Patent Document 1, a booming sound detected by a microphone or a vibration of a vehicle body detected by a G sensor attached to a seat or the like is larger than a preset setting value, that is, It is disclosed that the lock-up clutch is set to a semi-operating state (an intermediate state between the fluid coupling and the mechanical coupling) when adversely affecting the comfort. However, according to such a method, the lockup clutch is in a semi-operating state even when the lockup vibration is not anxious, that is, the road surface condition is bad or the surroundings are noisy. There is a problem that it is difficult.

Japanese Patent Laid-Open No. 06-193727

  Accordingly, an object of the present invention is made to solve the above-described problems of the prior art, and while improving the fuel efficiency during low-speed traveling where lock-up vibration occurs while preventing lock-up vibration. An object of the present invention is to provide a control device for a lockup clutch that can be used.

In order to achieve the above object, according to the first aspect of the present invention, a lock-up clutch incorporated in a torque converter that transmits engine power to the automatic transmission side via a fluid is activated or deactivated according to vehicle speed and engine load. In the lockup clutch control device,
The control device includes first detection means for detecting vibration of the suspension mounting portion and second detection means for detecting vibration of the vehicle body, and the detected value detected by the first detection means and the first detection means. The vibration level difference between the suspension mounting portion and the vehicle body is calculated based on the detection value detected by the two detection means. If the vibration level difference is larger than a preset value, the lockup is performed. When the clutch is operated and the vibration level difference is equal to or smaller than a preset value, a control unit is provided to deactivate the lockup clutch.

  In order to achieve the above object, in the invention described in claim 2, in addition to the configuration of the invention described in claim 1, the set value is easy for the occupant to detect lock-up vibration that occurs during low-speed driving and low load. It includes a vibration level region.

  In order to achieve the above object, according to a third aspect of the present invention, in addition to the configuration of the first or second aspect of the present invention, when the control unit deactivates the lockup clutch, The lockup vehicle speed at which the lockup clutch is engaged is moved to the high speed running side until the level difference becomes larger than a set value.

  According to the first or second aspect of the present invention, when the vibration level difference between the suspension mounting portion and the vehicle body vibration is larger than a preset set value, that is, in a state where it is difficult for the occupant to detect the lock-up vibration. If present, the lockup clutch is actuated by the control device, and the power loss due to the torque converter slip is avoided to mechanically connect the input side and the output side of the torque converter. On the other hand, if the vibration level difference is less than or equal to the preset value, that is, if the occupant can easily detect the lock-up vibration, the lock-up clutch is deactivated by the control device, and the lock-up clutch is locked. The vibration is absorbed and alleviated by a torque converter that transmits power by fluid. As a result, the time during which full lockup occurs during driving when lockup vibration occurs increases, so that fuel consumption can be improved, and lockup clutch control that can prevent occurrence of lockup vibration in advance. An apparatus can be provided.

  According to the third aspect of the present invention, when the lock-up clutch is deactivated, the control unit increases the lock-up vehicle speed at which the lock-up clutch is engaged until the vibration level difference becomes larger than the set value. Move to the travel side. As a result, in addition to the operational effects of the first or second aspect of the invention, it is possible to further improve fuel efficiency while preventing the occurrence of lockup vibration.

  The lock-up clutch is activated when the vehicle is in a vehicle running state where it is difficult for the occupant to detect the lock-up vibration, and the lock-up clutch is deactivated when the vehicle is in a vehicle driving state where the occupant can easily detect the lock-up vibration. Improved vibration and fuel consumption.

  An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing a control device for a lockup clutch to which the present invention is applied, and FIG. 2 is a flowchart showing control contents of the lockup clutch to which the present invention is applied.

  As shown in FIG. 1, the lockup clutch 10 is a hydraulic single plate type, and is attached to a turbine 14 (output side) of a torque converter 13 disposed between an engine 11 and an automatic transmission 12. The lock-up clutch 10 locks up based on a control device (ECU) 15 having a built-in microcomputer for outputting a control signal for activating / deactivating the lock-up clutch 10 and a control signal output from the control device 15. And a hydraulic lock-up clutch actuator 16 that operates and deactivates the clutch 10.

  The control device 15 includes an automatic transmission output shaft rotational speed sensor 17 that detects an output rotational speed (vehicle speed) of the automatic transmission 12, an engine rotational speed sensor 18, an engine torque sensor 19, a kick down switch 20, and an accelerator pedal. Throttle valve angle sensor 21 interlocking with stepping allowance, select position sensor 22 for detecting the position of the AT select lever, and first detection means for detecting vibrations of at least one of the front and rear suspension mounting portions. Suspension mounting portion vibration detection sensor 23, for example, an output value from vehicle body vibration detection sensor 24 as a second detection means attached to the vehicle body floor near the seating position of the occupant and detecting vehicle body vibration, various other sensors, Each signal of a switch (not shown) is input. Then, the control device 15 determines the timing for operating and inactivating the lockup clutch 10 based on the signals input from the sensors and switches, and the control unit 150 operates and inactivates the lockup clutch actuator 16. An operation control signal is output.

  The lockup clutch actuator 16 includes a lockup duty solenoid valve, a lockup regulator valve, and a lockup control valve (not shown).

When an operation control signal for operating the lockup clutch is input from the control unit 150, the lockup clutch actuator 16 operates the lockup duty solenoid valve so as to lower the lockup duty pressure. Then, the lock-up control valve is pushed down by the action of the pilot pressure due to the decrease in the lock-up duty pressure, and connects the release circuit of the torque converter 13 (the oil passage, hereinafter the same) to the drain circuit. Further, since the hydraulic pressure from the lock-up regulator valve is guided to the apply circuit of the torque converter 13, a pressure difference is generated between the apply pressure and the release pressure. Due to this pressure difference, a lock-up piston (not shown) is operated to press-fit the lock-up clutch 10 to the impeller cover (drive plate) 25. Thereby, the impeller 26 (input side) of the torque converter 13 and the turbine 14 (output side) are mechanically connected.
The operating hydraulic pressure is supplied from a hydraulic pump 28 connected to the impeller cover 25 via a pump drive shaft 27.

  The lockup clutch actuator 16 operates the lockup duty solenoid valve so as to increase the lockup duty pressure when a non-operation control signal for deactivating the lockup clutch 10 from the control unit 150 is input. Then, the lock-up duty solenoid valve is pushed up by an increase in the lock-up duty pressure, and applies an operating pressure to the release circuit side. Moreover, since the connection circuit side is connected to the oil cooler circuit, a pressure difference is generated between the lockup release pressure and the lockup fastening pressure. Due to this pressure difference, the lock-up piston is detached from the impeller cover 25 side. Thereby, the impeller 26 of the torque converter 13 and the turbine 14 are connected via the fluid.

  Further, the control unit 150 of the control device 15 specifically reads the detection value from the suspension mounting portion vibration detection sensor 23 (S101) as shown in the flowchart of FIG. The detected value is read (S102), the vibration level difference between the suspension mounting portion and the vehicle body is calculated (S103), and the calculated vibration level difference is compared with a preset set value (S104). The set value is set in advance so as to include a vibration level region in which the occupant can easily detect lock-up vibration that occurs during low-speed running and low load.

  And, if the vibration level difference during low-speed driving and low-load is larger than the preset value, for example, the road surface is extremely uneven and the lock-up vibration that occurs during low-speed driving and low-load is difficult for passengers to detect If it is determined, the operation control signal is output to the lockup clutch actuator 16 (S105).

  When a clutch engagement signal is output from the control unit 150, the lockup clutch actuator 16 operates the lockup piston toward the impeller cover 25 so that the lockup clutch 10 is pressed against the impeller cover 25. The 13 impellers 26 and the turbine 14 are mechanically coupled without a fluid, and transmit engine torque to the automatic transmission in a state where power loss due to torque converter slip is avoided.

On the other hand, when the difference in vibration level during low-speed driving and low load is less than the preset value (S104), that is, the road surface is smooth and low-speed driving and lock-up vibration that occurs during low load is easily detected by the occupant. If it is determined that this is the state, a non-operation control signal is output (S106).
When a non-operation control signal is output from the control unit 150, the lockup clutch 10 is disengaged from the impeller cover 25 and the engine torque output from the engine 11 is impeller cover 25 connected to the crankshaft 29. And, as a rotational driving force is transmitted from the impeller 26 to the turbine 14 via the fluid, the engine torque fluctuation (lock-up vibration) is transmitted to the automatic transmission 12 side while being absorbed and relaxed by the fluid of the torque converter 13. Is done.

  Further, when the lock-up clutch 10 is inactivated, the control unit 150 increases the lock-up vehicle speed VON for engaging the lock-up clutch 10 by ΔV until the vibration level difference becomes larger than the set value (S107). By adding, it is set to move in a stepwise manner toward the high speed running side (S108). That is, the control unit 150 can variably set the lockup vehicle speed, and is configured to operate the lockup clutch 10 as much as possible without generating lockup vibration.

The control unit 150 is set so that the engine torque is transmitted by the fluid by deactivating the lock-up clutch 10 in order to use the torque amplification action of the torque converter 13 during low speed running and high load. Has been.
Furthermore, the control device 150 is set so as to temporarily deactivate the lockup clutch 10 when the gear position of the automatic transmission 12 is switched (during gear shift), and transmits power with fluid. To prevent shift shock.
Furthermore, the control device 150 is set to mechanically transmit the engine torque by operating the lock-up clutch 10 in order to avoid power loss due to torque converter slip during high speed running and low load. Yes.

  According to the lockup clutch control device having such a configuration, it occurs when the vibration level difference between the suspension mounting portion and the vehicle body vibration during low-speed running and low load is larger than a preset value, that is, during low-speed running. If it is difficult for the occupant to detect the lock-up vibration, the lock-up clutch 10 is actuated by the control unit 150 and the power loss due to the torque converter slip is avoided because the impeller 26 of the torque converter 13 and the turbine 14 are mechanically connected. Is done. On the other hand, if the vibration level difference is equal to or smaller than a preset value, that is, if the occupant can easily detect the lock-up vibration that occurs during low-speed driving, the lock-up clutch 10 is deactivated by the control unit 150. As a result, the lock-up vibration is absorbed and mitigated by the torque converter 13 that transmits power by the fluid. As a result, the time for full lock-up during low-speed running where lock-up vibration occurs increases, so that fuel consumption can be improved and the lock-up clutch that can prevent the occurrence of lock-up vibration can be prevented. A control device can be provided.

  Further, when the lock-up clutch 10 is deactivated, the control unit 150 moves the lock-up vehicle speed at which the lock-up clutch 10 is engaged to the high-speed travel side until the vibration level difference becomes larger than the set value. As a result, it is possible to further improve fuel efficiency while preventing the occurrence of lockup vibration.

It is the schematic which showed the control apparatus of the lockup clutch to which this invention was applied. It is the flowchart which showed the control content of the lockup clutch to which this invention was applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lockup clutch 13 Torque converter 15 Control apparatus 150 Control part 16 Lockup clutch actuator 23 Suspension attachment part vibration detection sensor (1st detection means)
24 vehicle body vibration detection sensor (second detection means)

Claims (3)

In a lockup clutch control device that operates and deactivates a lockup clutch incorporated in a torque converter that transmits engine power to the automatic transmission side via a fluid according to vehicle speed and engine load,
The control device includes first detection means for detecting vibration of the suspension mounting portion and second detection means for detecting vibration of the vehicle body, and the detected value detected by the first detection means and the first detection means. The vibration level difference between the suspension mounting portion and the vehicle body is calculated based on the detection value detected by the two detection means. If the vibration level difference is larger than a preset value, the lockup is performed. A control device for a lockup clutch, comprising: a control unit that operates a clutch and deactivates the lockup clutch when the vibration level difference is equal to or less than a preset value.   2. The control device for a lockup clutch according to claim 1, wherein the set value includes a vibration level region in which a rider can easily sense a lockup vibration that occurs during low speed running and low load.   When the lock-up clutch is deactivated, the control unit moves the lock-up vehicle speed at which the lock-up clutch is engaged to the high-speed running side until the vibration level difference becomes larger than a set value. The control device for a lockup clutch according to claim 1 or 2, wherein the control device is a lockup clutch.

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