JP3473168B2 - Failure determination method for lock-up function of hydraulic control AT - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining a failure of a lock-up function of a hydraulic control AT, and more particularly to a failure determination of a lock-up control mechanism added to an automatic transmission. The present invention relates to a failure determination method for a lock-up function of a hydraulic control AT which can enhance a self-diagnosis function of a vehicle. 2. Description of the Related Art Some vehicles are equipped with an automatic transmission in order to automatically convert and extract the driving force of an engine in accordance with a running state. [0003] Some automatic transmissions include a torque converter that increases and transmits torque through a fluid by a pump, a turbine, and a stator. In this torque converter, a lock-up clutch is provided for connecting / disconnecting the pump and the turbine to directly connect / separate the pump and the turbine to control lock-up of the torque converter. The lock-up of the torque converter is as follows:
Various signals from various sensors and various switches for detecting the engine operating state and various signals from various sensors and various switches for detecting the vehicle operating state are input to the control means,
The control means controls the operation of the lock-up control mechanism based on the various signals described above to adjust the oil pressure to the lock-up clutch. This is performed by connecting the pump and the turbine directly by connecting and operating the lock-up clutch by a difference in hydraulic pressure acting on both sides of the plate. That is, as shown in FIGS. 6 to 8, in a three-speed automatic transmission 102 connected to a vehicle engine (not shown), an input shaft 104, an intermediate shaft 106, and an output shaft 108 are coaxial. Is provided. The input shaft 104 has a torque converter 116 including a pump 110, a turbine 112, and a stator 114, and a lock-up clutch 11 for connecting / disconnecting the torque converter 116.
8 and an oil pump 120 are provided. A second clutch 122 is provided on the input shaft 104. This second clutch 12
2, a reverse clutch 124 is provided in communication therewith. Also, a third clutch 126 is provided on the input shaft 104.
Are connected. The one-way clutch 128 is in communication with the third clutch 126. The one-way clutch 128 is connected to the intermediate shaft 106. The intermediate shaft 106 is provided with a planetary input sun gear 130. A short pinion 134 supported by a planetary gear carrier 132 is attached to the planetary input gear 130.
Are engaged. Further, the planetary gear carrier 132
, A long pinion 136 is supported. The long pinion 136 meshes with the short pinion 134 and also meshes with the rear sun gear 138.
It meshes with the planetary ring gear 140. The rear sun gear 138 is connected to the planetary sun gear 142. This planetary sun gear 14
Reference numeral 2 denotes a low brake (low band) 144 whose rotation is suppressed. The output shaft 108 has a governor hub 14.
A governor 148 for detecting the vehicle speed via the motor 6 is provided. The governor hub 146 is provided with a parking lock ball 150. Further, an oil pan 152 is provided below the automatic transmission 102. This oil pan 152
Inside, a valve body 154 is provided. The automatic transmission 102 is constituted by a hydraulic circuit as shown in FIG. That is, in the automatic transmission 102, the hydraulic pressure from the oil pump 120 is controlled to control the torque converter 1
16, and a lock-up control valve 156, a pressure regulator valve 158, a manual valve 160,
1-2 shift control valve 162, 2-3 shift control valve 164, 3-2 control valve 166
, A low speed control valve 168, a high speed control valve 170, a servo 172, a vacuum modulator 174 operated by engine negative pressure, a detent pressure regulator valve 176, a detent valve 178, and a low reverse control valve 180.
, An accumulator 182 and a 1-2 accumulator 184. The lock-up control valve 156
Is provided with a lock-up solenoid valve 188 of a lock-up control mechanism 186. This lock-up solenoid valve 188
It is provided in the middle of the high-speed side gear oil passage, and is operated by control means (engine controller) 190 as shown in FIGS. A throttle opening sensor 192 and a vehicle speed sensor 194 are connected to an input side of the control means 190 so as to detect an engine operating state and a vehicle running state. In addition to the lock-up control valve 188 on the output side, the control means 190 has first and second solenoids 196 provided on a valve body 154 of the automatic transmission 102 for performing a shift operation. , 198 have been contacted. The program of the control means 190 is shown in FIG.
As shown in FIG. 3, a lock-up area and a lock-up off area for performing lock-up control / non-lock-up control of the lock-up clutch 118 are set according to the vehicle speed state and the throttle opening degree state. The shift control of the automatic transmission 102 is performed as shown in FIG. The control means 190 includes a
At 0a, the failure of the lock-up control mechanism 186 is determined by comparing the on / off of the lock-up solenoid valve 188 with the operation / non-operation of the lock-up clutch 118. Further, such a control device for an automatic transmission is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-176265 and Japanese Patent Publication No. 1-60711. JP-A-2-
Japanese Patent Publication No. 176265 discloses a system in which a transmission input rotation speed signal from a transmission input rotation speed sensor and an engine rotation speed signal from an engine rotation speed sensor are input to an electronic control unit. A means for calculating a difference between the engine speed and the transmission input speed based on the transmission input speed and the engine speed during the signal output of the lock-up control solenoid, and an actual operation state of the lock-up clutch. Determining means for detecting an electrical failure of the lock-up solenoid of the automatic transmission,
It can detect a mechanical failure of the lock-up control system and distinguish it. 1-6071
No. 1 discloses a line pressure regulating valve that regulates hydraulic oil supplied from an oil pump to a predetermined line pressure and supplies excess oil to a release oil chamber, and converts the excess oil to a predetermined converter pressure. A converter pressure adjusting valve for adjusting pressure, a shift valve for selectively supplying and discharging line pressure to a hydraulic engagement device of the gear transmission mechanism according to vehicle running conditions to shift the gear transmission mechanism to a predetermined gear position, and a shift valve. A direct-coupled clutch control valve for selectively supplying / discharging line pressure supplied / discharged via the valve to / from the engagement oil chamber in accordance with a vehicle traveling condition, wherein the shift valve shifts the gear transmission mechanism to a high speed stage. By supplying the line pressure to the direct-coupled clutch control valve when it is switched to, even if the direct-coupled clutch control valve is stuck on the engagement side of the direct-coupled clutch, the direct-coupled clutch is released when the vehicle starts, and the vehicle starts smoothly. It is intended to function. However, in the failure judgment of the conventional lock-up control mechanism, it is easy to check the lock-up function when the lock-up clutch is electronically controlled. In a controlled automatic transmission, a lock-up control mechanism is added to the torque converter later, so that lock-up control using oil in the hydraulic circuit on the highest speed gear side, that is, torque is turned on and off by the control means, The lock-up solenoid valve that sends oil pressure to the lock-up clutch of the converter is provided in the middle of the highest-speed gear oil passage, so that the control means turns on and off the lock-up solenoid valve and activates or deactivates the actual lock-up clutch. It happens that the operation does not correspond one-to-one. That is, when the lock-up solenoid valve is turned on as shown in FIG. 13, the lock-up solenoid valve is turned on. However, when the oil is not guided to the highest-speed gear oil passage in which the lock-up solenoid valve is provided. However, the lock-up control is not actually performed, and there is a disadvantage that the lock-up function is erroneously determined. In order to eliminate the above-mentioned disadvantages, the present invention provides an engine mounted on a vehicle connected to an automatic transmission provided with a torque converter. A lock-up clutch that is connected and released to directly connect and disconnect the pump and the turbine of the torque converter, adjusts oil pressure to the lock-up clutch to operate the lock-up clutch, and a lock-up control valve that operates the lock-up clutch. A lock-up control mechanism including a lock-up solenoid valve that is turned on and off so as to supply and cut off the hydraulic pressure to the control valve is provided. When the lock-up region is set by the throttle opening and the vehicle speed, the lock-up control mechanism is activated. The lock-up clutch is actuated via the By providing control means for performing a lock-up, providing the lock-up solenoid valve in the middle of the high-speed gear oil passage, and comparing the on / off of the lock-up solenoid valve with the operation / non-operation of the lock-up clutch. In the failure determination method of the lock-up function of the hydraulic control AT, in which the failure determination of the lock-up control mechanism is performed by the failure determination unit of the control unit, a command for performing the lock-up of the control unit by the failure determination unit and an actual An engine negative pressure is added to a failure determination condition in order to determine a failure in a state where the operation of the lock-up clutch is not different, and the engine negative pressure is added to a failure determination condition based on the engine negative pressure state and a failure determination region set by the throttle opening and the vehicle speed. The failure determination of the lockup control mechanism is performed. According to the method of the present invention, by adding the engine negative pressure, which is one of the shift control factors of the automatic transmission, to the failure determination condition of the lock-up control mechanism, it is possible to respond to a command from the control means. Thus, the function of the lock-up control mechanism can be checked by checking the ratio between the engine speed and the vehicle speed, whereby the self-diagnosis function of the vehicle can be enhanced. Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 5 show an embodiment of the present invention. In FIG. 3, reference numeral 2 denotes an engine mounted on the vehicle, and 4 denotes, for example, 3
It is an automatic transmission for speed. The automatic transmission 4 has first and second solenoids 8 and 10 for performing a speed change operation with the torque converter 6.
Is provided. The torque converter 6, as shown in FIG.
It comprises a pump 12, a turbine 14, and a stator 16.
The pump 12 is connected to a crankshaft (not shown) of the engine 2 via a cover member 18. Turbine 14
Are connected to the input shaft 20 of the automatic transmission 4. Stator 16 is held by one-way clutch 22. The torque converter 6 is provided with a lock-up clutch 24. This lockup clutch 2
4 is a joining member 2 attached to the inner surface of the cover member 18.
6, a clutch plate 28 axially movably and non-rotatably spline-coupled to the input shaft 20 to contact and separate from the joining member 26, and a clutch hydraulic chamber 30 formed between the cover member 18 and the clutch plate 28. have. The converter hydraulic chamber 3 is provided between the turbine 14 and the clutch plate 28.
2 are formed. The lock-up clutch 24 is connected and released to directly connect and disconnect the pump 12 and the turbine 14. One end of a first oil passage 34 communicates with the clutch hydraulic chamber 30. The other end of the first oil passage 34 communicates with a lock-up control mechanism 36. Also,
One end side of the second oil passage 38 communicates with the converter hydraulic chamber 32. The other end of the second oil passage 38 communicates with the lock-up control mechanism 36. The lock-up control mechanism 36 includes a lock-up control valve 40 and a lock-up solenoid valve 42. The lock-up control valve 40 has a valve body 44 and a valve body 46 which moves in the valve body 44 in the axial direction. The base end of the valve body 46 is connected to a bottomed cylindrical piston portion 48. A valve spring 52 is disposed in a valve hydraulic chamber 50 formed in the piston portion 48. The first, second, and third land portions 54, 56, 58 are sequentially provided on the valve body 46 from the distal end side.
Are formed. The valve body 46 is connected to the line pressure from the first line oil passage 60 on the proximal end and the second line oil passage 6 on the distal end side.
2 and is moved axially by a lock-up solenoid valve 42. This valve body 4
6, the piston portion 48 interrupts the first line oil passage 60, and the first land portion 54 connects the second oil passage 38.
And the cooler oil passage 64, the second land portion 56 connects and disconnects the secondary oil passage 66 and the first oil passage 34, and the third land portion 58 connects the first oil passage 34 and the valve-side drain oil passage 68. Is intermittent. The first line oil passage 60 is connected to the valve hydraulic chamber 50.
Through the communication oil passage 70 and the lock-up solenoid valve 42
Is connected to the drain oil passage 72 on the solenoid side. The lock-up solenoid valve 42 includes a solenoid body 74 to be energized and a solenoid body 7
4 moves in the axial direction by energizing / de-energizing 4
The solenoid valve includes a solenoid valve body that opens and closes the solenoid valve 0 and a solenoid spring 78 that biases the solenoid valve body. The lock-up solenoid valve 42 includes an automatic transmission 4 and a lock-up control mechanism 3 as shown in FIG.
The operation is controlled by a control means (ECM) 80 for operating the motor 6. An input side of the control means 80 is connected to a throttle opening sensor 82, a vehicle speed sensor 84, and an engine negative pressure detection sensor 86 for detecting an engine operating state and a vehicle running state. The output side of the control means 80 is connected to the first and second solenoids 8, 10 in addition to the lock-up solenoid valve 42. The control means 80 controls the operation of the lock-up control mechanism 36 in accordance with the engine operating state and the vehicle running state. As shown in FIG. 1, for example, a predetermined value set by the throttle opening and the vehicle speed is set. When the lock-up region is reached, the lock-up control mechanism 36 is operated to connect the lock-up clutch 24 to lock-up the torque converter 6. As shown in FIG. 2, the control means 80
A failure determination unit 80a is provided. The failure determination unit 80a determines the failure of the engine negative pressure in order to determine a failure in a state in which a command for performing lockup as described later does not differ from the actual operation of the lockup clutch 24. In addition to the conditions, the failure determination of the lockup control mechanism 36 is performed based on the ON failure determination region and the OFF failure determination region (see FIG. 1) set based on the engine negative pressure state, the throttle opening, and the vehicle speed. . In FIG. 1, in order to execute the detection of the failure determination of the lock-up function without erroneous determination, for example, the engine negative pressure is set to 300 ° as a determination condition for the OFF failure determination region. Hg or more, and the engine negative pressure is set to 350 as a determination condition for the ON failure determination region.
〓Hg or more. Next, the operation of this embodiment will be described. The control means 80 energizes the lock-up solenoid valve 42 when a predetermined lock-up region set by the throttle opening and the vehicle speed is reached. When the lock-up solenoid valve 42 is energized, as shown in FIG. 4, the solenoid valve body 76 retreats and the communication oil passage 70 is opened, so that the valve body 46 also retreats. Therefore, the first line oil passage 60 is cut off by the piston portion 48, the second oil passage 38 and the cooler oil passage 64 are cut off by the first land portion 54, and the second land portion 5 is closed.
6 connects the second oil passage 38 to the secondary oil passage 66, and the third land 58 connects the first oil passage 34 to the valve-side drain oil passage 68. As a result, the hydraulic pressure from the secondary hydraulic passage 66 acts on the converter hydraulic chamber 32 via the second hydraulic passage 38 and the torque converter 6, and the clutch plate 2
8 is moved toward the cover member 18 to move in the axial direction on the input shaft 20, the hydraulic pressure in the clutch hydraulic chamber 30 is guided from the first oil passage 34 to the valve-side drain oil passage 68, and the clutch plate 28 is connected to the joining member. 26 to lock up the torque converter 6. Then, when it comes out of the lockup area,
As shown in FIG. 5, when the power supply to the lock-up solenoid valve 42 is stopped (turned off) and the power supply to the lock-up solenoid valve 42 is stopped, the solenoid valve body 76 is pushed by the urging force of the solenoid spring 78. And the communication oil passage 70 is shut off, so that the valve body 46 is pushed forward. Due to the pushing of the valve body 46, the first land portion 54 connects the second oil passage 38 and the cooler oil passage 64, and the second land portion 56 shuts off the second oil passage 38 and the secondary oil passage 66. To connect the first oil passage 34 and the secondary oil passage 66,
The land 58 blocks the first oil passage 34 from the valve-side drain oil passage 68. Thereby, the hydraulic pressure from the secondary hydraulic passage 66 acts on the clutch hydraulic chamber 30 via the first hydraulic passage 34,
Further, the hydraulic pressure in the converter hydraulic chamber 32 is guided to the cooler oil passage 64 via the second oil passage 38, so that the clutch plate 28 is separated from the joining member 26, and the lock-up of the torque converter 6 is released. On the other hand, the failure judging section 80a of the control means 80 is based on the on / off failure judging region (see FIG. 1) set by the engine negative pressure state, the throttle opening degree state and the vehicle speed state. When the control unit 80 issues an ON command to the lock-up solenoid valve 42 to check that the lock-up solenoid valve 42 is ON while the control unit 80 issues an OFF command to the lock-up solenoid valve 42, An off fault is performed to check that the lock-up solenoid valve 42 is off when there is. At this time, the failure of the lockup control mechanism 36 is determined by checking the ratio between the engine speed and the vehicle speed in response to the command from the control means 80. That is, conventionally, the shift control of the hydraulically controlled automatic transmission 4 is usually performed by the engine negative pressure corresponding to the engine load state and the governor pressure generated in the governor of the output shaft corresponding to the vehicle speed. (See conventional FIGS. 6 to 14). Here, for example, in the three-speed automatic transmission 4,
The lock-up is performed by guiding the hydraulic pressure for the third speed to the lock-up clutch 24 by the lock-up solenoid valve 42 provided in the oil passage for the third speed, which is the high-speed gear side. Solenoid valve 42
In the case where the command to is as shown in FIG.
As is clear from A, the command from the control means 80 and the actual operation of the lock-up clutch 24 are different (unmatched) in the region. Therefore, in this embodiment, considering that a failure is determined in a state where there is no difference (unmatch), the engine negative pressure, which is one of the shift control factors of the hydraulic control, is considered. This is added to one of the failure determination conditions. Normally, the control unit 80 originally inputs the engine negative pressure for controlling the entire engine 2. 1, the lock-up function is checked by checking the ratio between the engine speed and the vehicle speed in response to a command from the control means 80. That is, the engine negative pressure is not used for the entire lock-up control,
It is used only for the failure determination of the lockup control mechanism 36. The engine negative pressure is set as one of the failure determination conditions, and the on / off of the lock-up solenoid valve 42 and the vehicle speed of the engine speed are compared. This makes it possible to check the lock-up function of the electronically activated lock-up control mechanism 36 added to the hydraulically controlled automatic transmission 4, and to enhance the self-failure judgment function of the vehicle. it can. Further, the failure judgment of the lock-up control can be dealt with only by changing the program of the control means 80, so that the configuration is simple and the cost can be reduced. In this embodiment, the idea is that the engine load may be input to one of the control factors by the control means 80 of the lock-up solenoid valve 42 from the beginning. Is a factor that changes extremely sensitively to a small change in the accelerator opening.Therefore, there is an inconvenience that it easily leads to hunting of lock-up, etc., so it is difficult to adopt it.Here, the engine load is It is advisable to use it as one of the conditions for determining the lock-up function. As is apparent from the above detailed description, according to the present invention, the state in which the command for locking up the control means is not different from the actual operation of the lock-up clutch by the failure determination unit. Hydraulic control is performed by adding an engine negative pressure to a failure determination condition in order to determine a failure in the lockup control mechanism based on the engine negative pressure state, the throttle opening, and the vehicle speed based on a failure determination area. In the lock-up control mechanism added to the automatic transmission, it is possible to check the lock-up function of the lock-up control mechanism by confirming the ratio between the engine speed and the vehicle speed in response to a command from the control means. The self-diagnosis function of the vehicle can be enhanced. Further, the present invention can be realized by slightly changing the program of the control means, so that the configuration is simple and the cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a lockup failure determination area. FIG. 2 is a block diagram of a lockup failure determination device. FIG. 3 is a schematic diagram of an engine and an automatic transmission. FIG. 4 is a hydraulic circuit diagram at the time of lock-up. FIG. 5 is a hydraulic circuit diagram at the time of lock-up release. FIG. 6 is a configuration diagram of a conventional automatic transmission for three speeds. FIG. 7 is a configuration diagram of components of the automatic transmission of FIG. 6; FIG. 8 is a view for explaining a planetary gear section in FIG. 6; FIG. 9 is a diagram illustrating the operation of the components of the automatic transmission in FIG. 6; FIG. 10 is a hydraulic circuit diagram of the automatic transmission of FIG. 11 is a configuration diagram of the lock-up control mechanism of FIG. FIG. 12 is a block diagram of the lock-up control mechanism of FIG. FIG. 13 is a diagram illustrating a lock-up area in FIG. 6; FIG. 14 is a diagram illustrating shift control of the automatic transmission in FIG. 6; [Description of Signs] 2 Engine 4 Automatic transmission 6 Torque converter 24 Lock-up clutch 36 Lock-up control mechanism 40 Lock-up control valve 42 Lock-up solenoid valve 80 Control means 80a Failure determination unit 82 Throttle opening sensor 84 Vehicle speed sensor 86 Engine Negative pressure sensor

Continuation of front page (56) References JP-A-5-126247 (JP, A) JP-A-3-74671 (JP, A) JP-A-2-176265 (JP, A) JP-A-58-24651 (JP) JP-A-63-57947 (JP, A) JP-A-60-1457 (JP, A) JP-A-59-187165 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) F16H 61/12 F16H 61/14

Claims (1)

(57) [Claim 1] An automatic transmission provided with a torque converter is connected to an engine mounted on a vehicle and provided to directly connect / separate a pump and a turbine of the torque converter. A lock-up clutch for connection and release operation is provided, a lock-up control valve for adjusting the oil pressure to the lock-up clutch to operate the lock-up clutch, and an on / off switch for supplying and disconnecting the oil pressure to the lock-up control valve. A lock-up control mechanism including a lock-up solenoid valve that is turned off is provided, and when the lock-up region is set according to the throttle opening and the vehicle speed , the lock-up clutch is operated via the lock-up control mechanism. Control means for performing lock-up of the torque converter. The control means determines the failure of the lock-up control mechanism by comparing the on / off of the lock-up solenoid valve with the operation / non-operation of the lock-up clutch by providing a solenoid valve in the middle of the high-speed gear oil passage. In the failure determination method for the lock-up function of the hydraulic control AT performed by the failure determination unit, the failure determination unit locks the control unit.
Command to perform lock-up and the actual lock-up
Switch to determine the failure in a state where the operation of the switches does not differ.
Add the down negative pressure to the failure determination condition, the hydraulic pressure control, characterized in that the failure determination of the lock-up control mechanism on the basis of the failure determination area set by the this engine negative pressure throttle opening and the vehicle speed AT lockup function failure determination method.