JPH08277931A - Failure determination method for lockup function of hydraulic control AT - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a lockup failure determination method for an automatic transmission by checking the ratio of engine speed to vehicle speed in response to a command from a control means. It is possible to check the lock-up function of and to enhance the self-diagnosis function of the vehicle. Therefore, according to the present invention, the failure determination of the lockup control mechanism is performed based on the failure determination region set by the engine negative pressure state, the engine operating state, and the vehicle traveling state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining a failure of a lockup function of a hydraulic control AT, and more particularly to a failure determination of a lockup control mechanism added to an automatic transmission and a self-diagnosis function of a vehicle. The present invention relates to a failure determination method of a lockup function of a hydraulic control AT that can be increased.

[0002]

2. Description of the Related Art Some vehicles are equipped with an automatic transmission in order to automatically convert the driving force of an engine according to the running state and take it out.

Some automatic transmissions are equipped with a torque converter for increasing and transmitting a rotational force through a fluid by means of a pump, a turbine and a stator.

In this torque converter, there is provided a lock-up clutch for performing lock-up control of the torque converter by connecting / disconnecting the pump and the turbine for direct connection / separation.

The lockup of this torque converter is
Various signals from various sensors and various switches that detect the engine operating state and various signals from various sensors and various switches that detect the vehicle operating state are input to the control means,
This control means controls the lock-up control mechanism based on the various signals described above to adjust the hydraulic pressure to the lock-up clutch, and when the predetermined lock-up region set by the engine operating state and the vehicle operating state is reached, the clutch The lockup clutch is connected by the hydraulic pressure difference acting on both sides of the plate to directly connect the pump and the turbine.

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 with each other. It is located at. The input shaft 104 includes a torque converter 116 including a pump 110, a turbine 112, and a stator 114, and a lockup clutch 11 that connects and disconnects 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
A reverse clutch 124 is provided in communication with the vehicle 2. Further, the input shaft 104 has a third clutch 126.
Are connected. A one-way clutch 128 is connected to the third clutch 126.

The one-way clutch 128 is connected to the intermediate shaft 106. A planetary input sun gear 130 is provided on the intermediate shaft 106. The planetary input gear 130 includes a short pinion 134 supported by a planetary gear carrier 132.
Are in mesh.

Also, this planetary gear carrier 132
A long pinion 136 is supported by. The long pinion 136 meshes with the short pinion 134, meshes with the rear sun gear 138, and
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
In No. 2, the rotation is suppressed by the low brake (low band) 144.

The output shaft 108 also has a governor hub 14
A governor 148 for detecting the vehicle speed via 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
A valve body 154 is provided inside.

The automatic transmission 102 is composed of 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, a lock-up control valve 156, a pressure regulator valve 158, a manual valve 160, and the like so as to operate 16 or operate components to perform a gear shift operation.
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 detinting valve 178, and a low / reverse control valve 180.
An accumulator 182 and a 1-2 accumulator 184 are provided.

Further, the lock-up control valve 156
A lockup solenoid valve 188 of the lockup control mechanism 186 is provided to control the operation of the lockup control mechanism 186.

The lockup solenoid valve 188 is
It is provided in the middle of the high speed side gear oil passage and is operated by the control means (engine controller) 190 as shown in FIGS.

A throttle opening sensor 192 and a vehicle speed sensor 194 are connected to the input side of the control means 190 so as to detect the engine operating state and the vehicle running state.

In addition to the lock-up control valve 188 on the output side of the control means 190, first and second solenoids 196 are provided on the 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 on region and a lock-up off region for lock-up control / non-lock-up control of the lock-up clutch 118 are set depending on the vehicle speed state and the throttle opening state.

The shift control of the automatic transmission 102 is performed as shown in FIG.

Further, the control means 190 has a failure determination section 19
At 0a, the failure determination of the lockup control mechanism 186 is performed by comparing ON / OFF of the lockup solenoid valve 188 and activation / non-operation of the lockup clutch 118.

A control device for such an automatic transmission is disclosed, for example, in Japanese Patent Laid-Open No. 2-176265 and Japanese Patent Publication No. 1-60711. JP-A-2-
In the one described in Japanese Patent No. 176265, 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 device, and the electronic control device Based on the transmission input rotation speed and the engine rotation speed during the signal output of the lockup control solenoid, a means for obtaining the difference between the engine rotation speed and the transmission input rotation speed, and an actual operating state of the lockup clutch. And a means for determining, by which, in addition to detecting an electrical failure of the lockup solenoid of the automatic transmission,
The mechanical failure of the lockup control system can be detected, and the distinction can be made. Japanese Patent Examination 1-6071
The one disclosed in Japanese Patent Publication No. 1 has a line pressure adjusting valve for adjusting the working oil supplied from the oil pump to a predetermined line pressure and for supplying the surplus oil to the releasing oil chamber, and the surplus oil for setting the predetermined converter pressure. A converter pressure adjusting valve for adjusting the pressure, a shift valve for selectively supplying / discharging the line pressure to / from a hydraulic engagement device of the gear shift mechanism according to vehicle traveling conditions to shift the gear shift mechanism to a predetermined shift speed, and a shift valve A direct-connection clutch control valve that selectively supplies and discharges the line pressure supplied and discharged via the valve to and from the engagement oil chamber according to the vehicle traveling conditions, and the shift valve shifts the gear transmission mechanism between high speed stages. By supplying the line pressure to the direct coupling clutch control valve when it is switched to, even if the direct coupling clutch control valve is stuck on the side where the direct coupling clutch is engaged, the direct coupling clutch is released when the vehicle starts and a smooth start is achieved. It is intended to function.

[0023]

However, in the failure determination of the conventional lockup control mechanism, when the lockup clutch is electronically controlled, it is easy to check the lockup function, but hydraulic control is performed. In an automatic transmission, a lock-up control mechanism is added to the torque converter later, so lock-up control using oil in the hydraulic circuit on the highest speed gear side, that is, lock-up of the torque converter by turning on / off by the control means Since the lock-up solenoid valve that sends hydraulic pressure to the up-clutch is provided in the middle of the gear oil passage on the highest speed side, the control means turns the lock-up solenoid valve on / off and the actual operation / non-operation of the lock-up clutch. It may happen that there is no one-to-one correspondence. In other words, when the lockup solenoid valve shown in FIG. 13 is reached, the lockup solenoid valve is turned on, but when the oil is not guided to the highest speed side gear oil passage in which the lockup solenoid valve is provided, Had the inconvenience that lock-up control was not actually performed, resulting in erroneous determination of the lock-up function.

[0024]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention provides an engine mounted on a vehicle with an automatic transmission provided with a torque converter connected thereto. A lock-up clutch for connecting / disconnecting the pump and the turbine to directly connect / disconnect the lock-up clutch is provided to operate the lock-up clutch by adjusting hydraulic pressure to the lock-up clutch and to this lock-up control valve. A lock-up control mechanism including a lock-up solenoid valve that is turned on and off to cut off the oil pressure is provided, and when the lock-up region set by the engine operating state and the vehicle running state is reached, the lock-up control mechanism is used. To operate the lockup clutch to lock the torque converter. A control means is provided for causing the up,
The lockup solenoid valve is provided in the middle of the high speed side gear oil passage, and the failure determination of the lockup control mechanism is performed by comparing ON / OFF of the lockup solenoid valve and operation / non-operation of the lockup clutch. In the failure determination method of the lockup function of the hydraulic control AT performed by the failure determination unit of the control means, based on the failure determination region set by the failure determination unit according to the engine negative pressure state, the engine operating state, and the vehicle running state. The failure determination of the lock-up control mechanism is performed.

[0025]

According to the method of the present invention, the engine negative pressure, which is one of the shift control factors of the automatic transmission, is added to the failure determination condition of the lockup control mechanism so that the engine can respond to the command from the control means. The function of the lockup control mechanism can be checked by confirming the ratio of the number of revolutions to the vehicle speed, which can enhance the self-diagnosis function of the vehicle.

[0026]

Embodiments of the present invention will be described in detail and specifically 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 connected to the engine 2.
It is an automatic transmission for high speed.

The automatic transmission 4 includes a torque converter 6 and first and second solenoids 8 and 10 for performing a shift operation.
Is provided.

The torque converter 6 is, as shown in FIG.
It consists of 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
Is connected to the input shaft 20 of the automatic transmission 4. The stator 16 is held by a one-way clutch 22.

The torque converter 6 is provided with a lockup 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 that is axially movable and non-rotatably spline-coupled to the input shaft 20 so as to contact and separate from the joint member 26, and a clutch hydraulic chamber 30 formed between the cover member 18 and the clutch plate 28. have. Further, the converter hydraulic chamber 3 is provided between the turbine 14 and the clutch plate 28.
2 is formed. The lockup clutch 24 is connected / released to directly connect / separate the pump 12 and the turbine 14.

One end of the first oil passage 34 communicates with the clutch hydraulic chamber 30. The other end of the first oil passage 34 communicates with the lockup control mechanism 36. Also,
One end 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 lockup control mechanism 36.

The lockup control mechanism 36 comprises a lockup control valve 40 and a lockup solenoid valve 42.

The lock-up control valve 40 has a valve body 44 and a valve body 46 that moves in the valve body 44 in the axial direction. The base end side of the valve body 46 is connected to a bottomed cylindrical piston portion 48. A valve spring 52 is arranged in a valve hydraulic chamber 50 formed in the piston portion 48. Further, the valve body 46 has the first, second, and third land portions 54, 56, 58 sequentially from the tip side.
Are formed. The valve body 46 has a line pressure from the first line oil passage 60 on the base end side and the second line oil passage 6 on the tip end side.
It is held by the line pressure from 2 and is axially moved by the lockup solenoid valve 42. This valve body 4
Due to the axial movement state of 6, the piston portion 48 connects and disconnects the first line oil passage 60, and the first land portion 54 makes 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. The configuration is intermittent.

The first line oil passage 60 has a valve hydraulic chamber 50.
Through the connecting oil passage 70 and the lock-up solenoid valve 42
Is connected to the solenoid side drain oil passage 72.

The lock-up solenoid valve 42 includes a solenoid main body 74 which is energized and a solenoid main body 7 which is energized.
4 is energized / de-energized to move axially to connect oil passage 7
It is composed of a solenoid valve body 76 for opening and closing 0 and a solenoid spring 78 for urging the solenoid valve body 76.

The lockup solenoid valve 42, as shown in FIG. 2, is used for the automatic transmission 4 and the lockup control mechanism 3.
The operation is controlled by a control means (ECM) 80 that operates the control unit 6.

A throttle opening sensor 82, a vehicle speed sensor 84, and an engine negative pressure detection sensor 86 are connected to the input side of the control means 80 in order to detect the engine operating state and the vehicle running state. In addition to the lockup solenoid valve 42, the first and second solenoids 8 and 10 are connected to the output side of the control means 80.

The control means 80 actuates and controls the lockup control mechanism 36 in accordance with the engine operating state and the vehicle running state, and as shown in FIG. 1, for example, a predetermined value set by the throttle opening and the vehicle speed. When the lock-up region is reached, the lock-up control mechanism 36 is operated to engage the lock-up clutch 24 to lock-up the torque converter 6.

The control means 80, as shown in FIG.
A failure determination unit 80a is provided, and the failure determination unit 80a locks up based on the ON failure determination region and the OFF failure determination region (see FIG. 1) set by the engine load state, the engine operating state, and the vehicle traveling state. Control mechanism 3
The failure determination of No. 6 is performed.

In FIG. 1, in order to execute the detection of the failure determination of the lock-up function without making an erroneous determination, for example, an engine negative pressure of 300 〓 is used as the 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.

In the control means 80, the lockup solenoid valve 42 is energized when a predetermined lockup region set by the engine operating state and the vehicle running state is reached.

When the lockup solenoid valve 42 is energized, as shown in FIG. 4, the solenoid valve element 76 retracts to open the communication oil passage 70, and thus the valve element 46 also retracts. 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 cut off.
6 connects the second oil passage 38 and the secondary oil passage 66, and the third land portion 58 connects the first oil passage 34 and the valve side drain oil passage 68. As a result, the hydraulic pressure from the secondary oil passage 66 acts on the converter hydraulic chamber 32 via the second oil passage 38 and the torque converter 6, and the clutch plate 2
8 is pushed toward the cover member 18 to move axially on the input shaft 20, and the oil pressure in the clutch hydraulic chamber 30 is guided from the first oil passage 34 to the valve side drain oil passage 68 to join the clutch plate 28 to the joining member. 26, and the torque converter 6 is locked up.

Then, when it comes out of the lock-up area,
As shown in FIG. 5, when the energization of the lock-up solenoid valve 42 is stopped (OFF), and the energization of the lock-up solenoid valve 42 is stopped, the solenoid valve body 76 is pushed by the urging force of the solenoid spring 78. Then, the communication oil passage 70 is shut off and the valve body 46 is pushed forward. By pushing the valve body 46 forward, 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. Together with connecting the first oil passage 34 and the secondary oil passage 66,
The land portion 58 shuts off the first oil passage 34 and the valve side drain oil passage 68. Thereby, the oil pressure from the secondary oil passage 66 acts on the clutch oil pressure chamber 30 via the first oil passage 34,
Further, the oil pressure in the converter oil pressure chamber 32 is guided to the cooler oil passage 64 via the second oil passage 38, so that the clutch plate 28 separates from the joining member 26, and the lockup of the torque converter 6 is released.

On the other hand, the failure determination section 80a of the control means 80 is based on the on / off failure determination area (see FIG. 1) set by the engine load state, the engine operating state, and the vehicle running state, that is, The control means 80 makes an ON failure to check the state where the lockup solenoid valve 42 is ON even though the lockup solenoid valve 42 is an OFF command, or the control means 80 is an ON command to the lockup solenoid valve 42. Then, the lock-up solenoid valve 42 is turned off to check the off state. At this time, the failure of the lockup control mechanism 36 is determined by checking the ratio of the engine speed to 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 carried out 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 FIGS. 6 to 14 of the related art). Here, for example, in the automatic transmission 4 of the third speed,
The lockup is executed by guiding the hydraulic pressure for the third speed to the lockup clutch 24 by the lockup solenoid valve 42 provided in the oil passage for the third speed, which is the high speed gear side. Solenoid valve 42
If the command to the command is as shown in FIG.
As is clear from A of No. 2, the command of the control means 80 and the actual operation of the lockup clutch 24 are different (unmatched) in the region.

Therefore, in this embodiment, considering that the failure determination is made in the state where there is no difference (unmatch), in order to do so, the engine negative pressure, which is one of the shift control factors of the hydraulic control, is set. This is added to one of the failure determination conditions. Normally, the control means 80 originally inputs the engine negative pressure for the purpose of controlling the entire engine 2, so this engine negative pressure is used. 1, the lockup function is checked by defining the failure determination area and confirming the ratio between the engine speed and the vehicle speed in response to the command from the control means 80. In other words, engine negative pressure is not used for the entire lockup control,
It is used only for determining the failure of the lockup control mechanism 36. Further, the engine negative pressure is used as one of the failure determination conditions, and the on / off of the lockup solenoid valve 42 is compared with the vehicle speed of the engine speed.

As a result, the lockup function of the electronically operated lockup control mechanism 36 added to the hydraulically controlled automatic transmission 4 can be checked, and the self failure determination function of the vehicle can be enhanced. it can.

Further, the failure determination of the lockup control can be dealt with only by changing the program of the control means 80, and the structure is simple and the cost can be reduced.

In this embodiment, the idea is that the engine load may be input as one of the control factors from the beginning by the control means 80 of the lockup solenoid valve 42. This is the engine load. Is a factor that changes extremely sensitively even to small changes in the accelerator opening, so it is difficult to use because of the inconvenience that it is easily linked to hunting for lockup, etc., and here the engine load is It is a good idea to use it as one of the criteria for the lockup function.

[0050]

As is apparent from the above detailed description, according to the present invention, the lockup is performed by the failure determination unit based on the failure determination region set by the engine negative pressure state, the engine operating state, and the vehicle running state. In the lockup control mechanism added to the hydraulically controlled automatic transmission by determining the failure of the control mechanism, the lockup control mechanism is confirmed by checking the ratio of the engine speed and the vehicle speed in response to the command from the control means. It is possible to check the lockup function of the vehicle, which can enhance the self-diagnosis function of the vehicle.

Further, the present invention can be realized by only slightly changing the program of the control means, has a simple structure, and can be inexpensive.

[Brief description of 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 during lockup.

FIG. 5 is a hydraulic circuit diagram when lockup is released.

FIG. 6 is a configuration diagram of a conventional automatic transmission for three speeds.

7 is a configuration diagram of components of the automatic transmission of FIG.

FIG. 8 is a diagram illustrating a planetary gear portion of FIG.

FIG. 9 is a diagram illustrating the operation of the components of the automatic transmission of 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.

12 is a block diagram of the lockup control mechanism of FIG. 6. FIG.

FIG. 13 is a diagram illustrating a lockup area in FIG. 6;

14 is a diagram illustrating shift control of the automatic transmission of FIG.

[Explanation of symbols]

 2 engine 4 automatic transmission 6 torque converter 24 lockup clutch 36 lockup control mechanism 40 lockup control valve 42 lockup solenoid valve 80 control means 80a failure determination unit 82 throttle opening sensor 84 vehicle speed sensor 86 engine negative pressure sensor

Claims (1)

[Claims] 1. A lock-up clutch which is provided by connecting an automatic transmission equipped with a torque converter to an engine mounted on a vehicle, and which is connected / released to directly connect / separate a pump and a turbine of the torque converter. A lock-up control valve that is provided to adjust the hydraulic pressure to the lock-up clutch to operate the lock-up clutch and a lock-up solenoid valve that is turned on and off to cut off the hydraulic pressure to the lock-up control valve. A lock-up control mechanism that controls the lock-up of the torque converter by operating the lock-up clutch via the lock-up control mechanism when the lock-up region is set by the engine operating state and the vehicle running state. Means to raise the lockup solenoid valve. A failure determination of the lockup control mechanism is made by comparing the ON / OFF of the lockup solenoid valve with the operation / non-operation of the lockup clutch provided in the middle of the high speed side gear oil passage. In a failure determination method for a lockup function of a hydraulic control AT performed by a lockup control mechanism, the lockup control mechanism is based on a failure determination region set by the failure determination section according to an engine negative pressure state, an engine operating state, and a vehicle running state. The failure determination method for the lock-up function of the hydraulic control AT is characterized by performing the failure determination.