JPH0361070B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a lock-up clutch control system for a transmission, and more particularly to a system for preferentially releasing a lock-up clutch in the event of wheel slip. When a vehicle with a transmission equipped with a lock-up clutch slips while driving on snowy roads, sandy roads, etc., the wheel rotation speed increases rapidly, the apparent vehicle speed increases, and the lock-up clutch is activated. . If the driver who feels the vehicle slips in this state applies the brakes, the wheels are suddenly locked by the brakes before the lock-up clutch is released because the inertia of the vehicle is small, causing the engine to stall. Such engine stalling is undesirable because it reduces the operability of the torque converter vehicle. It also causes damage to various parts of the drive system. Also, if the wheels get stuck in sandy or muddy ground while the vehicle is running in a locked-up state, and the load on the wheels suddenly increases and the wheels slip, if the driver applies the brakes, the engine may stall in the same way as mentioned above. spoil one's sexuality. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a means for releasing the lock-up clutch in the event of wheel slip. That is, according to the present invention, there is an instruction means for instructing the operation of the lock-up clutch device of a torque converter with a lock-up clutch according to the driving condition of the vehicle, and an instruction means for instructing the lock-up clutch device to operate or deactivate according to the instruction from the instruction means. a switching means for switching to operation; a wheel rotation speed detection means provided on the plurality of wheels and detecting the corresponding wheel rotation speed;
a slip detection means having a comparison means for comparing the wheel rotation speed detection signals detected by the wheel rotation speed detection means with each other, and detecting wheel slip by the comparison means and outputting a slip detection signal; A lock-up clutch control device for a torque converter is provided, comprising converting means for disabling the lock-up clutch device in priority over an instruction from an indicating means when a desired slip detection signal is output from the slip detecting means. Further, the slip detection means of the present invention outputs a slip detection signal when the wheel rotation speed detection signal from the wheel rotation speed detection means deviates from a desired range. Therefore, when an automobile having a transmission equipped with a lock-up clutch slips while driving on a snowy road or sandy road, the apparent vehicle speed increases and the indicating means instructs the switching means to operate the lock-up clutch device. Also, since the lock-up clutch device can be quickly released by the slip detection means and the speed change means, engine stalling in the event of a slip is prevented. Therefore, the operability of the torque converter vehicle is improved, and various parts of the drive system are not damaged. The present invention will be described in detail below based on drawings showing examples. The control device for the lock-up clutch device of a torque converter according to the present invention shown in FIG. 1 is also related to the speed change control device of the transmission, and is supplied to a servo mechanism that engages or releases various clutches and brakes in the transmission. regulator valve (not shown)
Use the line pressure that has already been regulated. As is well known, the lock-up clutch device directly connects the pump impeller 11 and turbine impeller 12 of the torque converter 10, which constitutes a part of the transmission, and the turbine impeller 12 is connected to the input shaft, and the pump impeller 12 is connected to the input shaft. The impeller 11 is connected to an output shaft connected to an auxiliary transmission. The control device according to the invention is used, for example, in a lock-up clutch device that is engaged or disengaged by switching the direction of flow of torque converter hydraulic fluid. As shown in FIGS. 1 and 2, the control device for the lockup clutch device 13 according to the first embodiment of the present invention includes a lockup instruction circuit 35 for instructing the lockup clutch device 13 to operate the lockup, and a lockup instruction circuit 35 for instructing the lockup clutch device 13 to operate the lockup. Switching devices 45 and 50 that switch the lock-up clutch device 13 into activation or deactivation according to instructions from the instruction circuit 35, and sensors 1 that detect wheel rotational speeds corresponding to a plurality of wheels.
5a to 15c, and a slip detection circuit 20 that detects the slip of the wheel 14 based on the output signals from these sensors 15a to 15c and outputs a slip detection signal.
The converter circuit 40 is comprised of a conversion circuit 40 which takes priority over the lockup instruction circuit 35 and deactivates the lockup clutch device 13 when a desired slip detection signal is output from the slip detection circuit 20. Note that these circuits show each rotation inside the ECU shown in FIG. The lock-up instruction circuit 35 instructs the lock-up clutch device 13 to operate the lock-up.
A signal is output to the solenoid valve 45 of the switching device according to a predetermined gear ratio, vehicle speed, etc. or the running state of the vehicle when a specific manual lever is operated. It can be constructed from a circuit like this. The wheel rotational speed detecting sensors 15a to 15c are, for example, comprised of a magnet 16 fixed to the axle and a reed switch 17 opened and closed by the magnet 16, as shown in FIG. These sensors 15 are provided on at least two or more wheels 14. These sensors 15a to 15c are preferably attached to all of the driving wheels and at least one of the driven wheels, and do not need to be attached to all of the driven wheels. For example, in the case of four-wheel drive, it is preferable to attach sensors to all four wheels. The embodiment of the present invention is applied to rear wheel drive, and a sensor 15a consisting of a magnet 16 and a reed switch 17 is attached to the right rear wheel, and sensors 15b and 15c are attached to the left rear wheel and front wheel, respectively. They are provided on each side. The slip detection circuit 20 is a circuit that detects the slip of the wheel 14 from the output of the sensor 15, and is composed of a frequency/voltage transmission 21 and a comparison circuit 18 at the next stage, and in the example shown in FIG. 18
Three sets are provided. Frequency/voltage transformer (F/
V) 21 is the reed switch 17 of each sensor 15.
The pulse frequency generated by the reed switch 17, which opens and closes, is converted into voltage by the magnet 16, which is connected to the reed switch 17 and is connected to the reed switch 17, which can be constructed from a conventional digital/analog converter and rotates with the wheel. That is, a voltage proportional to the wheel rotation speed is generated at its output terminal. (Note that this output can be input not only to the slip detection but also to the lock-up instruction circuit 35 or the transmission control device (not shown). The next-stage comparison circuit 18 includes a first comparator 22a,
A pair of second comparators 2 connected to this output terminal
6, 27, and an AND circuit 32a connected to its output terminal. Since the other two comparison circuits 18b and 18c in the description are similarly configured, only the configuration of the comparison circuit 18a will be described. At the input terminal of the first comparator 22a of the comparison circuit 18a,
Respective output voltages V _A and V _B from converters 21a and 21b are input. That is, the output terminal of the converter 21a is connected to the first comparator 22a via the resistor 23.
The output terminal of the converter 21b is connected via the resistor 23 to the inverting input terminal of the first comparator 22a. First comparator 22
Voltage dividing resistors 24 and 25 that determine the reference voltage V ₁ are connected to the non-inverting input terminal of a. Therefore, the first comparator 22a outputs a voltage V _A as shown in FIG.
and V _B , and outputs a voltage V _C proportional to the input voltage difference V _A - V _B with the reference voltage as the center. The first comparators 22b and 22c of the other comparison circuits also perform comparison operations in the same way. The output terminal of the first comparator 22a is connected to the non-inverting input terminal of one comparator 26 and the inverting input terminal of the other comparator 27 of a pair of second comparators 26 and 27 in the next stage. A first reference voltage determined by voltage dividing resistors 28 and 29 is connected to the inverting input terminal of the comparator 26.
V ₃ is input, and the comparator 26 compares the output voltage V _C of the first comparator 22a in the previous stage with this first reference voltage V ₃ , and when V _C > V ₃ , the comparator 26 outputs “H” to its output terminal. ” symbol and outputs an “L” signal when V _C <V ₃ . On the other hand, a second reference voltage V ₂ (V ₂ >V ₃ ) determined by the voltage dividing resistors 30 and 31 is input to the non-inverting input terminal of the comparator 27.
This comparator 27 compares the output voltage V _C of the first comparator 22a in the previous stage with the second reference voltage V ₂ , and outputs an "L" symbol to its output terminal when V _C > V _{2 and} when V _C < _V2
When this happens, the "H" symbol is output. The reference voltage range V ₂ -V ₃ corresponds to a predetermined range of rotation speed difference between normal wheels that are not in a slip state. And V _C
is within this predetermined range, the second comparators 26, 27
outputs an "H" symbol, and when it deviates from a predetermined range, outputs an "L" symbol. Therefore, when V _C <V ₃ or V _C >V ₂ , an "L" signal is output as a slip state, but when V _C <
V ₃ indicates a slip condition in a region where the rotational speed difference between the rear right wheel and the rear left wheel is negative.
V _C >V ₂ indicates a slip condition in a region where the rotational speed between the rear right wheel and the rear left wheel is positive. The outputs of these second comparators 26 and 27 are
It is input to the AND gate 32a. AND gate 3
The output terminal of 2a outputs an "H" signal when an "H" signal is input to the twin input terminals, and if an "L" signal is input to one of the input terminals, the output becomes "L". ”. That is, AND gate 32
A detects a slip condition by checking whether the rotational speed between wheels provided with sensors 15a and 15b is within a predetermined range. AND gates 32a~ of each comparison circuit 18a~c
Since the output terminal of c is connected to the input terminal of one output AND gate 33, if a slip larger than a predetermined value occurs between any of the wheels, the output of the gate 33, that is, the control unit 20 becomes "L". , if all the speed differences between the wheels are within a predetermined range, an "H" level is output. Therefore, the slip state can be detected sensitively without impairing the driving performance of the vehicle, and the lock-up clutch device 13 can be quickly released by the conversion circuit 40, which will be described later. The output terminal of the slip detection circuit 20 and the output terminal of the lockup instruction circuit 35 are connected to the output terminal of the conversion circuit 40.
The output A of the slip detection circuit 20 and the lockup instruction circuit 35 are connected to the AND gate 41.
The relationship between the output B and the output F of the AND gate 41 is
As shown in the table below.

[Table] Therefore, even if the lock-up command signal "H" is output from the lock-up command circuit 35 of output B, if slip occurs between any of the wheels,
A slip detection signal "L" is output from the slip detection circuit 20 of output A, and the AND gate 41 outputs "L".
Output a signal. As a result, the conversion circuit 40 preferentially releases the lockup clutch device 13. Referring again to FIG. The switching device is a solenoid valve 45 that is opened and closed by a lock-up instruction circuit 35.
and a switching valve 50 that switches the flow direction of hydraulic oil to the torque converter 10. The switching valve 50 is a spool valve as shown in the figure, and the first land 5
1, a first input that has a second land 52 and a third land 53, includes a spool 54 biased by a spring 67, and is connected to a line 55 that supplies pressure oil whose pressure is regulated by a pressure regulating valve; A port 56, a second input port 58 communicating with a chamber 57 provided at one end, and a first torque converter hydraulic oil port 59 and a second torque converter hydraulic oil port provided on both sides of the first input port 56. 60 and a first exhaust port 61 connected to an oil cooler (not shown). The first and second torque converter hydraulic oil ports 59 and 60 are
The second input port 58 is connected to the torque converter 10 through lines 62 and 63, respectively.
It is connected to the line 55 via an orifice 64. The solenoid valve 45 is a normally closed type valve in which a valve hole 66 is closed by a spring 65 when the current is not energized, and the orifice 64 and the second input port 5
8 and communicates with the chamber 57. Next, the operation of this control device will be described. First, after the vehicle is started, the transmission control device (not shown) automatically changes gears according to the vehicle speed and the amount of depression of the accelerator pedal, and the gear is automatically changed to a state suitable for lock-up. Then, an exciting current is applied to the solenoid valve 45 from the lock-up instruction circuit 35 of the electronic control unit ECU, and the valve hole 66 is opened. Therefore, the pressure oil accumulated in the chamber 57 is removed from the valve hole 6 of the solenoid valve 45.
6, the internal pressure of the chamber 57 decreases, the spool 54 is urged upward in the drawing by the spring 67, and the switching valve 50 is in the right half state. Therefore, the second land 52 is located between the first torque converter hydraulic oil port 59 and the first discharge port 61, and the third land 53 is located between the first input port 56 and the second torque converter hydraulic oil port 60. located in between. Therefore, the pressure oil from the line 55 passes through the first input port 56, the first torque converter hydraulic oil port 59, and the line 62.
is sent to the torque converter 10 and then to the line 6.
3 and is discharged through the second torque converter hydraulic oil port 60. Therefore, the lock-up clutch device 13 is engaged and the turbine impeller 12 is engaged.
and the pump impeller 11 are directly connected. In such a lock-up state, if the difference in rotation speed between the vehicles is within a predetermined range, lock-up is maintained even if the rotation speeds of the left and right wheels are slightly different during cornering, for example. Therefore, it is possible to accurately discriminate between a slip state and a cornering state, and since the lockup is not released during cornering, the behavior of the vehicle is stabilized. Next, if the wheels 14 slip and the rotational speed difference between the wheels deviates from the predetermined range, the AND
Since the "L" signal is input to the gate 41, the excitation current of the solenoid valve 45 is cut off preferentially (ie, even if the lock-up clutch device 13 is engaged).
Therefore, the valve hole 66 is closed and pressure oil is introduced into the chamber 57 via the orifice 64. As a result, the spool 54 is pressed downward in the drawing against the spring 67, and the spool 54 is located at the position shown in the left half. The second land 52 is
The third land 53 is located between the input port 56 and the first hydraulic oil port 59, and the third land 53 is located between the input port 56 and the first hydraulic oil port 59.
0 and the second discharge port 68. As a result, pressure oil from line 55 is transferred to first input port 5
6. The second hydraulic oil is sent through the port 60 and the line 63 in the opposite direction to that during lock-up, and after being supplied to the torque converter 10, the first hydraulic oil is sent through the line 62.
The oil is sent to an oil cooler (not shown) through the hydraulic oil port 59 and the first discharge port 61. Therefore,
The direction of hydraulic fluid feed to the torque converter 10 is reversed and the lock-up clutch device 13 is released. After that, torque transmission is done by torque converter 10
This prevents the engine from stalling when braking, and also prevents the engine from stalling even when the vehicle is rocked back and forth on muddy ground, etc., greatly improving the operability of torque converter vehicles with a lock-up clutch. can be improved. In the first embodiment described above, wheel slip is detected by an electric circuit and the lock-up state is released preferentially, but in the second embodiment shown in FIGS. 4 to 7, wheel slip is detected by a hydraulic circuit. The system detects this and releases the lockup state preferentially. As is clear from FIG. 4, in the second embodiment, the solenoid valve 45 is constantly controlled only by the lock-up instruction circuit 35 of the ECU, while the output of the slip detection hydraulic circuit 20' is directly input to the switching valve 50'. It is becoming more and more common. FIG. 5 shows a hydraulic circuit diagram of the sensor (governor valve) 15' and the slip detection hydraulic circuit 20'. The sensor 15' consists of a housing 71 that is integrally fixed to a wheel shaft 70, a valve body 72 that can reciprocate within the housing 71, and a shaft 74 that moves together with the valve body 72 and has a weight 73 attached to its tip. When the wheel 14 rotates, the shaft 74 and the valve body 72 move outward due to the centrifugal force applied to the weight 74, causing the valve body 72 and the housing 71 to move outward.
The distance between the two wheels increases, and a pressure corresponding to the rotational speed of the wheel is generated at the outlet port 75. The slip detection hydraulic circuit 20' consists of valve devices 80 and 90 corresponding to the comparison circuit 18 and AND gates 32 and 33, respectively, of FIG. The comparison valve device 80a is a pilot-operated three-port switching valve, and outputs from sensors 15'a and 15'b are applied as pilot pressure to both ends. Therefore, if the speed difference between the rear right wheel and the rear left wheel is within a predetermined range, the left and right pressures are almost the same, so the comparison valve device 80a is in the state shown, and no pressure is generated in the line 81a. . If a slip occurs and the rotational speed of one of the wheels changes, and the pressure difference supplied to both sides of the comparison valve device 80a goes out of a predetermined range, the comparison valve device 80a moves in either direction, causing pressure to flow into the line 81a. Pressure from source 82 is generated. Configurations of the other two comparison valve devices 80b and 80c,
Since the operation is also the same, the explanation will be omitted. The outputs 81a to 81c of each comparison valve device 80 are input to the valve device 90 to form an OR gate, and when pressure is generated in any of the lines 81a to 81c, the spool is pressed downward and the output line 91
pressure is generated. That is, if a slip exceeding a predetermined range occurs between any of the wheels, pressure is generated in the output line 91. Referring again to FIG. The switching valve 50' of the embodiment shown in this figure is almost the same as the switching valve of FIG. An independent valve body 9 is provided between the chamber 57 and the chamber 57.
3 are fitted together so that they can reciprocate. This valve body 93
and spool 54 are independent of each other, and the fifth
In the state shown in the figure, the valve body 93 and the spool 54 are simply in contact with each other. The operation of the embodiment shown in FIG. 4 will be described. First, when no wheel slip is detected, that is, when no pressure is generated in the output line 91 from the slip detection hydraulic circuit 20', no pressure is applied to the port 92 either. In this state, when a predetermined gear ratio and vehicle speed are obtained or the lock-up manual lever is operated, a lock-up signal is issued from the lock-up instruction circuit 35 of the ECU. The solenoid of the solenoid valve 45 for this purpose is energized, the valve hole 66 is opened, and the line pressure in the line 55 is drained through the orifice 64 and the valve hole 66, so that no pressure is applied to the chamber 57. Therefore, the spool 54 is held in the position shown in the right half of the switching valve 50' in FIG. It is discharged from port 68. When a slip is detected under such lock-up operating conditions and pressure is generated in the output line 91 from the slip detection hydraulic circuit 20' and pressure is applied to the port 92, the valve body 93 and the spool 54 are moved by the force of the spring 67. It is pushed downward against the force, the torque converter hydraulic oil supply line is reversed, and the lockup is released. In the embodiment shown in FIG. 6, each output of the comparison valve device shown in FIG. 5 is applied directly to the switching valve 50'' to release lock-up preferentially. A first port 101, a second port 102, and a third port 103 are provided in the valve hole 95 that communicates with the valve hole 95, and the outputs 81a to 81c of the comparison valve device 80 in FIG. 5 are connected to these ports,
Inside the valve hole 95, there are first, second and third valve bodies 104, 105, 1 which are independent of each other and correspond to each port.
06 is slidably fitted. This switching device is the same as the switching device shown in FIG. 4 except for the portion above the chamber 57 of the switching valve 50''. Lockup instruction circuit 3 of the ECU
When a lock-up signal is issued from 5, the spool 54 is pressed upward in the drawing by the spring 67, and the valve bodies 104, 105, and 106 are also pressed upward, but a slip is detected and the line 81
When pressure is generated in any one of a to c, one of the valve bodies 104, 105, and 106 is pressed downward in the drawing and pushes down the spool 54, so that the lockup is released. FIG. 7 shows yet another embodiment. This conversion device 40'' is based on a patent application filed by the applicant of the present application.
This is the same as that disclosed in No. 56-572785, and due to the pressure difference between the vehicle speed signal applied to the switching valve 110 and port 111 and the throttle signal (including the throttle kickdown signal) applied to the port 112, It is now possible to perform lock-up control,
The output 91 of the slip detection hydraulic circuit 20' is applied to the port 113 to release the lockup preferentially.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a first embodiment of a lock-up clutch control device according to the present invention, which detects a slip using an electric circuit and releases the lock-up state preferentially, and FIG. An electric circuit diagram showing the electronic control unit in detail, Figure 3 is a graph showing the relationship between the input of the comparator and its output, and Figure 4 is a hydraulic circuit that detects a slip and releases the lock-up state preferentially. A diagram showing a second embodiment of the lock-up control device according to the present invention, FIG. 5 shows a hydraulic circuit of the sensor and slip detection means, and FIG. 6 shows another embodiment of the transmission means of FIG. 4. figure,
FIG. 7 is a diagram showing another embodiment of the switching valve device. 10...Torque converter, 13...Lockup clutch device, 15...Wheel rotation speed sensor (wheel rotation speed detection means), 18...Comparison circuit (comparison means), 20...Slip detection circuit (slip detection means) , 35... Lockup instruction circuit (instruction means), 40... Conversion circuit (conversion means), 45...
...Solenoid valve (switching means), 50... Hydraulic oil switching valve (switching means).

Claims (1)

[Scope of Claims] 1. An instruction means for instructing the operation of a lock-up clutch device of a torque converter with a lock-up clutch according to the driving condition of the vehicle, and an instruction means for instructing the operation of the lock-up clutch device of a torque converter with a lock-up clutch according to the instruction of the instruction means. A switching means for switching to non-operation, a wheel rotation speed detecting means provided on a plurality of wheels and detecting the corresponding wheel rotation speed, and a wheel rotation speed detection signal detected by the wheel rotation speed detecting means mutually. a slip detection means which has a comparison means for comparison, and which detects wheel slip by the comparison means and outputs a slip detection signal; and when the slip detection means outputs a desired slip detection signal, the slip detection means a lock-up clutch control system for a torque converter, comprising converting means for deactivating said lock-up clutch system over the instructions of said means. 2. The lock-up clutch control device for a torque converter according to claim 1, wherein said slip detection means outputs a slip detection signal when the wheel rotation speed detection signal from said wheel rotation speed detection means deviates from a desired range.