JPH0810017B2 - Hydraulic clutch - Google Patents

Description

The present invention relates to a hydraulic clutch, and particularly to calculating a proper gear position, and automatically shifting the gear position by an actuator so as to obtain a value obtained by this calculation. The present invention relates to a hydraulic clutch suitable for use in combination with an automatic transmission adapted to change

[Outline of Invention]

The present invention detects the hydraulic pressure applied to a hydraulic clutch attached to an automatic transmission by a sensor, and feeds back the detection value of this sensor to control the hydraulic pressure. Moreover, when the sensor fails, the sensor The hydraulic pressure is controlled without feeding back the output, so that the control can be continued even if the hydraulic pressure sensor fails.

[Conventional technology]

Automatic transmissions have been proposed in order to avoid the driver's cumbersome shifting operations. This automatic transmission selects a gear used by a computing unit such as a microcomputer according to a vehicle speed, an accelerator opening degree, etc., and meshes the gear selected by an actuator to automatically obtain a predetermined gear ratio. It was done. By equipping an automobile with such an automatic transmission, it is almost unnecessary to operate a lever for a shift operation of a driving vehicle.

[Problems to be solved by the invention]

For example, a hydraulic clutch is attached to such an automatic transmission. The hydraulic clutch is automatically disengaged to change the gear position. The hydraulic pressure of the hydraulic clutch is detected by a hydraulic sensor, and the detected value is fed back to control the hydraulic pressure. Therefore, according to such an automatic transmission, if the hydraulic pressure sensor fails, the control of the hydraulic clutch is disabled and the vehicle moves.

The present invention has been made in view of the above problems, and a hydraulic clutch that is configured to be continuously controlled even if a hydraulic sensor fails, thereby preventing the vehicle from becoming stuck. It is intended to provide.

[Means for solving problems]

The present invention relates to a hydraulic clutch having a single-plate type clutch main body in which a clutch disc is interposed between a flywheel fixed to a flex plate attached to one end of a crankshaft and a clutch cover. The clutch body is connected by frictionally engaging the clutch disc with the pressure receiving surface of the clutch cover by pressing the piston plate through the pressure plate, and the friction engagement portion of the clutch disc is provided by the oil spray means. Oil is injected into the hydraulic cylinder, the hydraulic pressure generated by the hydraulic pressure generating means is supplied to the hydraulic cylinder and the oil spray means, and the hydraulic pressure of the hydraulic pressure generating means is controlled by the hydraulic valve. Oil pressure on the output side of In addition to the detection by the sensor, when the hydraulic pressure sensor fails, the failure detection means detects it, and normally the first hydraulic pressure control means feeds back the detection value of the hydraulic pressure sensor to generate the hydraulic pressure by the hydraulic valve. The hydraulic pressure on the output side of the means is feedback-controlled, and when the hydraulic sensor fails, the second hydraulic control means controls the hydraulic valve in an open loop without feeding back the detected value of the hydraulic sensor. is there.

[Action]

The clutch body is switched to the connected state by frictionally engaging the clutch disc with the pressure receiving surface of the clutch cover via the pressure plate by the piston of the hydraulic cylinder operated by the hydraulic pressure generated by the hydraulic pressure generating means. On the other hand, when the hydraulic pressure to the hydraulic cylinder is released, the frictional engagement between the clutch disc and the pressure receiving surface of the clutch cover is released, and the clutch is switched to the disengaged state. Then, oil is sprayed to the friction engagement portion of the clutch disc by the oil spraying means to lubricate the friction engagement portion.

The hydraulic pressure applied to the hydraulic cylinder and the oil spray means is controlled by a hydraulic valve. Normally, the first hydraulic control means feeds back the detection value of the hydraulic sensor to control the hydraulic valve. The oil pressure on the output side of the oil pressure generating means is controlled. On the other hand, if the oil pressure sensor fails, the second value is returned without feeding back the detection value of the oil pressure sensor.
The hydraulic pressure control means controls the hydraulic valve in an open loop, so that even when the hydraulic pressure sensor fails, the output side of the hydraulic pressure generation means generates an almost appropriate hydraulic pressure.

〔Example〕

One embodiment of the present invention will be described below. FIG. 2 shows an engine of an automobile equipped with an automatic transmission according to an embodiment of the present invention, which is composed of a diesel engine 10 for trucks. The diesel engine 10 is equipped with a fuel injection pump 11, which sequentially supplies fuel to each cylinder of the engine 10. The combustion injection pump 11 is driven by the engine 10 via a timer 12, and the timing of fuel injection is adjusted by the timer 12. Further, the fuel injection pump 11 is provided with a governor 13, and this governor 13
The fuel injection amount is adjusted accordingly.

On the rear side of the engine 10 is a flywheel housing 14
The flywheel fixed to the end of the crankshaft is accommodated in the housing 14. A hydraulic clutch 30 is provided on the rear side of the franc wheel, and the flywheel housing 14 is connected to the clutch 30.
A transmission 15 is mounted on the rear side of the transmission. The transmission 15 changes the rotation speed of the engine 10 to a predetermined value and transmits the rotation to the drive wheels via a propeller shaft 16.

The transmission 15 constitutes an automatic transmission, and a shift actuator is provided above the transmission.
17 and a select actuator 18 are provided. Further, a hydraulic actuator 19 for controlling connection and disconnection of the clutch 30 mounted on the rear side of the flywheel is mounted on the flywheel in the housing 14. Further, on the front end side of the fuel injection pump 11, there is provided a fuel control actuator 20 for adjusting the position of the control rack to control the fuel supply amount. These four actuators 17, 18, 1
The 9 and 20 are driven based on an instruction from the microcomputer 21 via driving means.

The input side of the microcomputer 21 is connected to a control box 22. The control box 22 has a speed change lever 23. Further, the micro computer 21 is connected to an accelerator sensor 25 that detects the accelerator opening degree or the depression amount of the accelerator pedal 24. Further, the microcomputer 21 is connected to the vehicle speed sensor 26, the engine rotation sensor 27, the rack sensor 28, the clutch sensor 29, and the oil temperature sensor 31, respectively.

The vehicle speed sensor 26 is provided on the side surface of the transmission 15, and the vehicle speed is detected by the number of rotations on the output side of the transmission 15. The engine rotation sensor 27 is mounted on the front side of the engine 10 and detects the number of revolutions of the engine 10.
The rack sensor 28 is attached to the tip end side of the actuator 20 and detects the position of the control rack of the fuel injection pump 11. Further, the clutch sensor 29 is attached to the distal end side of the clutch actuator 19, and detects the connection and disconnection states of the clutch 30. The oil temperature sensor 31 is attached to the oil pan of the clutch 30 so as to detect the oil temperature of the clutch 30.

Next, the structure of the hydraulic clutch 30 will be described with reference to FIG. 3. A rear end of a crankshaft 35 is inserted into the front end of the flywheel housing 14, and a flex plate 36 is attached to the crankshaft 35.
Is stuck. A ring gear 37 is fixed to the outer peripheral side of the flex plate. A flywheel 38 is fixed to the flex plate 36. The hydraulic cylinder 19 is provided on the flywheel 38, and slidably supports the piston 40.

The piston 40 has an arm 41 and this arm
The pressure plate 42 is supported by 41. The pressure plate 42 engages the clutch facing 44 attached to the clutch disc 43 with the clutch cover 45.
To the pressure receiving surface. The clutch disc 43 is connected to a hub 47 via a buffer spring 46.

An oil pump 49 is provided in a clutch housing 48 fixed to the flywheel housing 14, and the oil pump 49 is a gear fixed to the clutch cover 45.
The pump 51 is driven via a drive gear 52 of a pump 49. Also, the oil pump 49 is a strainer 53.
And the strainer 53 sucks the oil in the oil pan 54. Further, the oil pump 49 is connected to an oil spray hole 55 so as to inject oil to the clutch facing 44.

Retainer 56 attached to the outer periphery of clutch shaft 50
A pair of ports 57 and 58 are formed in the a and the sleeve 56b, respectively, and these ports 57 and 58 are connected to the port 49a of the oil pump 49 via a switching valve (not shown). Further, the ports 57 and 58 are connected to the oil supply holes 61 and 62 of the flywheel 38 via passages 60 inside the pipe 59 and outside the pipe 59, respectively.

Next, the operation of the automatic transmission having the above configuration will be described. This operation is performed based on a program preset in the microcomputer 21, and when the position of the speed change lever 23 of the control box 22 is the automatic position, the speed change operation is automatically performed. There is. On the other hand, when the shift lever 23 is at the manual position, the shift operation manually selected is performed via the actuators 17 and 18.

The outline of the automatic shift operation will be described. The microcomputer 21 detects whether or not the position of the shift lever 23 of the control box 22 is the automatic position, and in the case of the automatic position, the accelerator pedal 24 is depressed at a constant cycle. The amount or accelerator opening and the vehicle speed are read from the accelerator sensor 25 and the vehicle speed sensor 26, respectively. Further, the microcomputer 21 reads a map stored in the memory and, based on this map, calculates whether automatic shift is possible or not. If automatic gear shifting is possible, a gear shifting operation is performed to obtain the calculated gear ratio. On the other hand, when it is determined that the automatic shift is impossible, the shift operation is not performed.

The specific operation of automatic shifting is performed by the microcomputer 21.
, The shift actuator 17 and the select actuator 18 are actuated via drive means (not shown) to select the gears of the transmission 15.
Of the selected gears is achieved. Therefore, a predetermined gear ratio can be obtained in this way. During this gear shifting operation, the clutch 30 is temporarily switched to the disengaged state by the hydraulic actuator 19, and the clutch 30 is brought into the engaged state again in synchronization with the end of the gear shifting operation.

Next, the operation of the hydraulic clutch 30 will be described.
The oil accumulated in 54 is sucked through the strainer 53, and the oil is pressurized and sent out.
The pressurized oil is sprayed to the clutch facing 44 through the oil spray hole 55, thereby lubricating and cooling the friction portion of the clutch facing 44, and a half-clutch state such as creep running continues for a long time. However, the clutch is configured to be sufficiently durable.

Further, the oil pump 49 is connected to the ports 57 and 58 of the retainer 56a and the sleeve 56b via a switching valve (not shown). When connected to port 57, the hydraulic cylinder through pipe 59 and oil passage 61
By supplying oil to the anterior chamber of 19, this will push the piston 40 rearward. Therefore, the pressure plate 42 covers the clutch facing 44 and the clutch cover
Press the 45 pressure receiving surface to switch the clutch to the connected state.

On the other hand, another port 5 of the sleeve 56b is operated by a switching valve (not shown) in which the oil pump 49 is linked with the control device.
When in communication with 8, the piston will pass through the passage 60 outside the pipe 59 and the oil supply hole 62 in the flywheel 38.
Oil will be supplied to the rear chamber of 40. Therefore, in this case, the piston 40 moves forward, and the pressing of the clutch facing 44 by the pressure plate 42 is released. As a result, the clutch 30 is switched to the disconnected state.

The hydraulic clutch 30 that performs the switching operation in this manner
The hydraulic pressure of the working oil is controlled by a feedback loop as shown in FIG.
That is, the hydraulic pressure applied to the actuator 19 of the clutch 30 is detected by the hydraulic pressure sensor, and the detected value is fed back to the target hydraulic pressure side.
Then, the target current is set from the two hydraulic data, and the current applied to the solenoid coil is controlled by the current control. Note that duty control is performed here, whereby the opening of the hydraulic valve is controlled and the hydraulic clutch 30 is controlled. By such feedback control, the actuator 19 of the hydraulic clutch 30 is always operated with an appropriate hydraulic pressure according to the operation.

The output characteristic of the hydraulic sensor is as shown in FIG. 5, and when it is operating normally, an output is produced between the upper and lower abnormal regions. Therefore, when the hydraulic pressure sensor indicates values in the upper and lower abnormal regions, the microcomputer 21 determines that the hydraulic pressure sensor has failed, and switches from closed loop feedback control to open loop control.

FIG. 1 shows this open loop, and a target hydraulic pressure is given in response to a signal from the control unit of the clutch. Then, the microcomputer 21 reads the current value corresponding to the target hydraulic pressure from the map stored in advance in the memory, and controls the duty of the solenoid coil so that this current value is obtained. Therefore, the opening degree of the hydraulic valve is controlled by the open loop, and thus the control of the hydraulic clutch 30 is continued. Therefore, even if the oil pressure sensor fails, the vehicle can be allowed to travel and the vehicle can be prevented from becoming stuck.
That is, the closed-loop feedback control, which is more appropriately controlled during normal operation, is performed, and when the hydraulic sensor fails, the open-loop control of the hydraulic valve opening is performed in an emergency evacuation to control the vehicle opening. It is possible to run.

〔The invention's effect〕

As described above, according to the present invention, by supplying the hydraulic pressure generated by the hydraulic pressure generating means to the hydraulic cylinder and pressing the clutch disc through the pressure plate by the piston, the clutch disc is rubbed against the pressure receiving surface of the clutch cover. By engaging them, the clutch body is connected. On the other hand, when the supply of hydraulic pressure to the hydraulic cylinder is released, the frictional engagement between the clutch disc and the pressure receiving surface of the clutch cover is released, and the clutch body is switched to the disengaged state. Therefore, it becomes possible to provide a hydraulic clutch in which the contact and separation are automatically switched by the operation of the hydraulic cylinder.

In addition, since oil is sprayed by the oil spray means to the friction engagement portion between the pressure receiving surface of the clutch cover and the clutch disc, the friction engagement portion is lubricated by such oil, and the clutch Even if the disk slips, it is possible to prevent the abrasion of the facing of the clutch disk. Further, it becomes possible to maintain the half-clutch state for a long time, which makes it possible to perform a special operation such as creep running.

Further, the hydraulic pressure of the hydraulic pressure generating means for generating the hydraulic pressure supplied to the hydraulic cylinder and the oil spray means is controlled by the first hydraulic pressure control means, and the detection value detected by the hydraulic pressure sensor is fed back. By controlling the hydraulic valve, the hydraulic pressure is maintained at an appropriate value. Therefore, proper hydraulic pressure is supplied to the hydraulic cylinder and the oil spray means, respectively.

Further, when the hydraulic sensor fails, the second hydraulic control means controls the hydraulic valve in an open loop without feeding back the detected value of the hydraulic sensor. It becomes possible to continuously supply an almost appropriate hydraulic pressure. Therefore, even if the oil pressure sensor fails, the oil pressure clutch can perform its function almost normally, and it is possible to prevent the vehicle from becoming stuck due to the oil pressure sensor failure.

[Brief description of drawings]

FIG. 1 is a block diagram showing the open loop control of a hydraulic clutch provided in an automatic transmission according to an embodiment of the present invention, FIG. 2 is a block diagram showing the overall configuration of the automatic transmission, and FIG. FIG. 4 is a vertical sectional view of the hydraulic clutch, FIG. 4 is a block diagram showing feedback control of the hydraulic clutch, and FIG. 5 is a graph showing output characteristics of the hydraulic sensor. In the reference numerals used in the drawings, 17 ... shift actuator 18 ... select actuator 19 ... clutch actuator (hydraulic cylinder) 21 ... microcomputer 30 ... clutch 35 ... crankshaft 36 ... flex plate 38 ... … Flywheel 40 …… Piston 42 …… Pressure plate 43 …… Clutch disc 44 …… Clutch facing 45 …… Clutch cover 49 …… Oil pump 55 …… Oil spray hole.

 -------------------------------------------------------------------------------------------------------------- --- Continuation of the front page (56) Reference JP-A-60-215143 (JP, A) JP-A-60-249760 (JP, A) JP-A-62-1090 (JP, A) JP-A-60- 183233 (JP, A) JP 62-41404 (JP, A) JP 61-197825 (JP, A) JP 59-142450 (JP, A) JP 61-41066 (JP, A) Actual Development Sho 60-131733 (JP, U) Japanese Patent Sho 54-41664 (JP, B2)

Claims (1)

[Claims] 1. A single plate type clutch main body in which a clutch disc is interposed between a flywheel fixed to a flex plate attached to one end of a crankshaft and a clutch cover, and the clutch disc is prestressed by a piston. A hydraulic cylinder that connects the clutch body by frictionally engaging the clutch disc with the pressure receiving surface of the flywheel cover by pressing through a plate, and oil that injects oil to the friction engagement portion of the clutch disc Spraying means, hydraulic pressure generating means for generating hydraulic pressure to be supplied to the hydraulic cylinder and the oil spraying means, hydraulic valve for controlling the hydraulic pressure of the hydraulic pressure generating means, and hydraulic pressure sensor for detecting the hydraulic pressure on the output side of the hydraulic valve. And if the oil pressure sensor fails, Failure detection means for detecting, first hydraulic control means for feeding back the detection value of the hydraulic pressure sensor to feedback control the hydraulic pressure on the output side of the hydraulic pressure generation means by the hydraulic valve, and when the hydraulic pressure sensor fails Is a second hydraulic control means for controlling the hydraulic valve in an open loop without feeding back the detection value of the hydraulic sensor.