JPS6250703B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Technical Field The present invention relates to a torque converter used by being inserted into a power transmission system such as an automatic transmission for a vehicle, and in particular to a torque converter that adjusts the relative rotation (slip) between its input and output elements to an appropriate setting value. The present invention relates to a slip control device for a torque converter that is capable of such slip control.

(2) Prior art A torque converter transfers power between its input and output elements via hydraulic oil, and has a torque increasing function and a torque fluctuation absorbing function. power transmission efficiency is poor. Therefore, under conditions where torque fluctuation is still a problem but the torque increase function is hardly required, slip control is possible so that the relative rotation between input and output elements is the minimum necessary (set value) to absorb torque fluctuation. Some slip control type torque converters are already in use, which are capable of increasing power transmission efficiency while ensuring the necessary torque fluctuation absorption function of the torque converter.

This type of torque converter generally includes an input element driven by a power source and an output element driven by hydraulic fluid stirred by the input element,
It is common to be able to control the slip between the input and output elements by appropriately sliding a lock-up clutch so that the relative rotation becomes a set amount of slip.

By the way, if the lock-up clutch is poorly connected during sliding connection or if the clutch facing is unevenly worn, it will generate a connection vibration called yudder. Since the lock-up clutch maintains a sliding connection, once this jamder occurs, it tends to continue to occur during slip control, and during this time vibrations and abnormal noises are generated, causing discomfort to the occupants. In this sense, if judder occurs during slip control, it is preferable to stop the control by disabling the lock-up clutch.

(3) Purpose of the Invention From this point of view, an object of the present invention is to provide a slip control device for a torque converter that can solve the above-mentioned problems of vibration and abnormal noise by canceling slip control when jamder occurs in the lockup clutch. do.

(4) Structure of the invention For this purpose, the slip control device of the present invention is
Input element 2 driven by power source 1 as shown in the figure
and an output element 3 driven by the hydraulic oil stirred thereby, and a lock-up clutch 5 is provided so that the relative rotation between the input and output elements detected by the slip amount detection means 4 becomes a set value. In a slip control type torque converter provided with a clutch control means 6 for slidingly coupling the clutch, there is provided a jamder detecting means 7 for detecting the jaggedness of the lockup clutch 5 from the degree of variation in the relative rotation, and a jaggedness detecting means 7 for detecting the jaggedness of the lockup clutch 5 when detected by the means. said clutch control means 6 to discontinue the sliding connection of the clutch;
The present invention is characterized in that it is provided with a slip control canceling means 8 for effecting the slip control.

(5) Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 2 shows the slip control device of the present invention together with a torque converter in a vehicle automatic transmission to be controlled by the slip control device, in which 10 is an engine as a power source, 11 is its crankshaft, 12 is a flywheel, and 13 is a The torque converter 14 is a torque converter output shaft. During operation, the engine 10 moves the crankshaft 11 to the flywheel 12.
The torque converter 13 has a pump impeller (input element) 13a which is drive-coupled to the crankshaft 11 via the flywheel 12 and is constantly driven by the engine, and a turbine runner (output element) 13b opposed to this. , a stator (reaction force element) 13c, and a turbine runner 13b is drivingly connected to an output shaft 14, and the stator 13c is placed on a hollow fixed shaft 16 via a one-way clutch 15. In the torque converter 13, the working fluid from the pump 17 is supplied to the internal converter chamber 13d via the supply path 18, and this working fluid is returned to the reservoir 20 via the return path 19, and is cooled by a radiator 21 provided on the way. do. Note that a pressure holding valve (not shown) is inserted into the return path 19, thereby keeping the inside of the converter chamber 13d at a pressure (converter pressure) Pc below a certain value. Thus, as described above, the pump impeller 13a driven by the engine stirs the internal working fluid, causes it to collide with the turbine runner 13b, and then flows through the stator 13c, during which time the turbine runner 13b is torqued under the reaction force of the stator 13c. Rotate while increasing. During operation in such a converter state, the torque converter 13 can transmit the power of the engine 10 to the output shaft 14 while suppressing vibration and increasing torque while generating slip (relative rotation) between the input and output elements 13a and 13b. The power from the output shaft 14 is changed in speed by the gear transmission mechanism 42 to rotate the drive wheels of the vehicle, thereby allowing the vehicle to travel.

The torque converter 13 further includes a clutch (lock-up clutch) 22 for controlling and canceling the slip in a slip control type and a lock-up type, which is connected to a torsional damper 23.
The lock-up chamber 24 is drivingly coupled to the output shaft 14 via the shaft and is movable in the axial direction on this shaft. The clutch 22 moves to the left in the figure in response to the lock-up pressure PL/u in the lock-up chamber 24 and the converter pressure Pc in the converter chamber 13d, and operates the input/output element 1 with a force corresponding to this differential pressure.
It is assumed that the slip of the torque converter 13 can be controlled and stopped by drivingly coupling between 3a and 13b.

The lockup pressure PL/u is adjusted as described below by the slip control valve 25. For this purpose, the lockup chamber 24 is communicated with the port 25a of the slip control valve 25 through the hollow hole of the shaft 14 and the circuit 26. The valve 25 is separately connected to the converter pressure.
Port 25b led to PC by circuit 27
and a drain port 25c, and the spool 25
When d is in the neutral position shown in the figure, port 25a is blocked from both ports 25b and 25c, when spool 25d moves to the left in the figure, port 25a becomes port 25b, and when spool 25d moves to the right in the figure, port 25a becomes a port. 25c, respectively.

The spool 25d has a converter pressure Pc that acts on the pressure receiving area difference of the spool lands in the chamber 25e.
and the lock-up pressure PL/u that acts on the pressure-receiving area difference of the spool land in the chamber 25f.
The control pressure Ps is generated by the control pressure generating circuit 28 and the solenoid valve 29 as follows in response to the force exerted by the control pressure Ps and the force exerted by the control pressure Ps acting on the left end surface of the spool in the chamber 25g.

That is, the control pressure generation circuit 28 has one end 28a.
more reference pressure (e.g. line pressure in the case of automatic transmission)
P _L is supplied and this line pressure is applied to the orifice 28.
It drains from the other end 28b of the circuit 28 through channels c and 28d. By determining this drain amount by the duty-controlled solenoid valve 29, the orifice 28
A control pressure Ps can be created between c and 28d, which is led to chamber 25g by circuit 30.

The electromagnetic valve 29 includes a plunger 29a and a solenoid 29b that moves the plunger 29a to the left in the drawing when it is energized. When the solenoid 29b is energized, the plunger 29a moves to the left, thereby closing the drain opening end 28b. Then, energizing (energizing) the solenoid valve solenoid 29b
is a slip control computer 3 that performs slip control of a torque converter, which is the object of the present invention.
The duty control is performed so that the pulse width (ON time) of the pulse signal as shown in FIGS. 1 to 3A and 3B is repeated. However,
As shown in FIG. 3a, when the duty (%) is small, the time for the solenoid valve 29 to close the drain opening end 28b is short, and therefore the control pressure Ps is the difference between the pressure receiving areas of the orifices 28c and 28d as shown in FIG. It is a constant value determined only by Duty (%) is shown in Figure 3b
As the pressure increases as shown in FIG. 4, the solenoid valve 29 closes the drain opening end 28b for a long time, and the control pressure Ps gradually increases as shown in FIG. 4 and finally becomes equal to the line pressure _PL .

In FIG. 2, as the control pressure Ps increases, this control pressure causes the spool 25d to move to the right as shown in FIG. . On the other hand, as the control pressure Ps decreases, the spool 25d is moved to the left as shown in FIG.
5a is gradually opened to the port 25b, and the lockup pressure PL/u increases. By the way, the control pressure Ps increases as the duty (%) increases as shown in Figure 4, so the lock-up pressure
PL/u is the duty (%) as shown in Figure 6.
It is maintained equal to the converter pressure Pc in a small region of , decreases as the duty (%) increases, and finally changes to zero.

The slip control computer 31 is operated by the power supply +V, and receives an engine cooling water temperature signal S _T from the temperature sensor 32, an engine rotation speed (rotation speed of the input element 13a) signal Sir from the rotation speed sensor 33,
Output rotation speed of the gear transmission mechanism 42 from the rotation speed sensor 34 (the rotation speed of the output element 13b is determined by multiplying this rotation speed by the gear ratio of the gear transmission mechanism 42) signal
Sor, engine throttle opening signal S _TH from throttle opening sensor 35, and gear position sensor 4
Gear position (gear ratio) of gear transmission mechanism 42 from 3
The duty control of the electromagnetic valve 29 is performed as described below in response to the signals Sg related to the electromagnetic valve 29, respectively.

For this purpose, the computer 31 uses, for example, a seventh
The microcomputer shown in the block diagram in the figure is a microprocessor unit (MPU) 36 including a random access memory (RAM) as usual, and a read-only memory (ROM) 37.
and input/output interface circuit (I/O) 38
and an A/D converter 39. This microcomputer receives the signals Sir and Sor from the sensors 33 and 34 after being waveform-shaped by the waveform shaping circuit 40, and also inputs the signals S _T and S _TH from the sensors 32 and 35 by the A/D converter 39. The signal Sg from the sensor 43 is inputted after being converted into a digital signal, and the control program shown in FIG. 8 is executed based on these input signals to control the solenoid valve solenoid 29b via the amplifier 41. do.

FIG. 8 shows an interrupt routine, in which the following arithmetic processing is performed every time an interrupt signal is received from a timer (not shown) at regular time intervals ΔT in step 50, and the torque converter 13 is adjusted to the slip amount curve shown in FIG. 10, for example. Control the slip according to the diagram. 1st
Figure 0 shows the vehicle speed and the throttle opening of the engine 10.
That is, it represents the operating mode of the torque converter 13 that should be achieved for each operating state of the engine 10, and here, complete C/V means that the lock-up clutch 22 is completely deactivated and the torque converter 13 is operated in the input/output elements 13a, 13b is not directly connected to the converter (maximum slip amount), and complete L/U means that the lock-up clutch 22 is fully actuated and the torque converter 13 connects the input/output elements 13a and 13b. This is a lock-up region where power is transmitted in a directly connected lock-up state (zero slip amount), and in addition, S/
A lock-up clutch 22 is slidably connected to L, and the torque converter 1 is adjusted by adjusting the joint force.
This is the slip control region where the slip amount (relative rotational speed of the input/output elements 13a, 13b) of No. 3 should be set as the set value.

First, in step 51 of Figure 8, MPU3
Step 6 reads the gear position of the gear transmission mechanism 42 based on the signal Sg from the sensor 43, and in the next step 52, checks whether the cooling water temperature of the engine 10 is low enough to indicate that the engine is being warmed up based on the signal _ST from the sensor 32. Determine. If so, since the engine 10 is being warmed up and the torque fluctuation is large, control proceeds to step 53, where the output duty is set to 0%. As is clear from Figure 6, this output duty of 0% means that the lockup pressure PL/u is equal to the converter pressure.
Same as PC, so lockup clutch 2
2 is inactive, the torque converter 13 operates in a converter (C/V) state, allowing smooth power transmission while absorbing large torque fluctuations.

If it is determined in step 52 that the engine 10 has completed warm-up, the control proceeds to step 54.
Then, the vehicle speed is read based on the signal Sor from the sensor 34, and in the next step 55, the engine throttle opening is read based on the signal _STH from the sensor 35, and then the process proceeds to step 56. control is advanced. In step 56, the MPU 36 uses table data stored in the ROM 37 that corresponds to the diagram in FIG.
It is determined whether the operating state should be in the range, S/L range, or complete L/u range.

If it is in the complete C/V range, step 57 is selected, and here, the brake flag JFLG, which will be described later, is reset to 0, and in the next step 53, the output duty is set to 0%, and the torque converter 1 is reset in the same manner as described above.
3 to function as specified in the converter state. If it is a complete L/u region, step 58 is selected, and here too, the jamder flag JELG, which will be described later, is reset to 0, and in the next step 59, the output duty is set to 100%. This output duty of 100% keeps the solenoid valve solenoid 29b in the energized state via the amplifier 41,
In this way, the lockup pressure PL/u is brought to the minimum value as is clear from FIG. Therefore, the lock-up clutch 22 is fully engaged and allows the torque converter 13 to function as specified in the lock-up state with zero slip.

If it is in the S/L region, control proceeds to step 60;
Here, it is determined whether the jamder flag JFLG has already been reset to 1 or not. The brake clutch JFLG is a lock-up clutch 2 as described below.
A flag indicating that 2 has caused a jadder.
If no judder occurred last time and JFLG = 0, the output duty calculation for slip control is performed in step 61, and torque converter 1 is calculated as shown below.
The slip coupling force of the lock-up clutch 22 is feedback-controlled so that the slip amount of the lock-up clutch 22 is maintained at the set value.

FIG. 9 shows the details of step 61. First, in step 70, the engine rotation speed (the rotation speed of the input element 13a) N _E is calculated based on the signal Sir from the sensor 33, and then in step 71, the engine rotation speed (the rotation speed of the input element 13a) N E is calculated based on the signal Sir from the sensor 33. The rotation speed N _T of the output element 13b is calculated by multiplying the output rotation speed of the gear transmission mechanism 42 based on the signal Sor and the gear ratio based on the gear position read in step 51. Next, in step 72, the input/output element 13
The rotation difference between a and 13b, that is, the torque converter 13
Calculate the slip amount ΔNn by ΔNn = N _E − N _T ,
In the next step 73, the slip amount ΔNn is set to A.
Store in RAM. The RAM stores the previous slip amount ΔNn _-1 as B, the previous slip amount ΔNn _-2 as C, and the previous slip amount ΔNn _-3 as D.

In the next step 74, the slip amount ΔNn is calculated from the slip amount setting value in the S/L region in FIG.
The slip error ΔX is calculated by subtracting the slip error ΔX. Control then proceeds to step 75 where the slip error Δ
Depending on whether or not X is larger than a certain value, for example 50 rpm, it is determined how far the slip control is progressing. If the slip control has progressed considerably and the lock-up clutch 22 is in a slippingly connected state, this lock-up clutch may generate a yudder, and of course ΔX≦50 rpm, so step 76~
80 are selected in sequence, and the occurrence of jitter is determined in these steps.

Now, to consider the phenomenon when the lock-up clutch 22 generates yaddle and when it does not, the output shaft torque and slip amount of the torque converter 13 during slip control when no yaddle is generated are shown in FIG. As shown in FIG. 13, the fluctuations are small in both cases, and therefore the fluctuation in the slip amount ΔN between calculation intervals is within 10 rpm as shown in FIG. On the other hand, the output shaft torque and slip amount of the torque converter 13 during slip control when a yander is generated repeats large hunting in a short period of time as shown in FIG. The fluctuation repeatedly exceeds 10 rpm as shown in FIG.

In steps 76 to 80, this phenomenon is used to determine the presence or absence of jitter, but in steps 76 to 78, the slip amount ΔN between calculation intervals is determined.
It is determined whether fluctuations of 10 rpm or more have occurred three times in a row, and in steps 79 and 80, it is determined whether or not the fluctuations are in a hunting state. That is, in steps 76 to 78 |A-B|, |B-C| and |C-
Determine whether D| is 10 rpm or more, and select one
If the speed is always below 10 rpm, it means that no jitter is occurring, and in this case, a PI calculation is performed in step 81, and the calculated value is updated in step 82. The PI calculation determines the output duty (%) so that the slip amount of the torque converter 13 approaches the set value, and thus the torque converter slip amount is ultimately maintained at the set value. In steps 79 and 80, (A-B), (B-C) and (B
-C)・(C-D) is positive or negative, that is, whether (A-B) and (B-C) are also (B-C)
It is determined whether and (C-D) have the same sign or different signs, and if even one is positive, the direction of change in slip amount is the same, so there is a fluctuation of 10 rpm or more in slip amount. However, since this is not a hunting state, it means that no jadder is occurring.
In this case as well, normal slip control is executed by selecting steps 81 and 82.

By the way, the discrimination results from steps 76 to 78 are |
A-B｜＞10rpm, |B-C｜＞10rpm, |C-
D | > 10 rpm, and in addition, the discrimination results from steps 79 and 80 are (A-B)・(B-C)<(B-C)・
If (C-D) < 0, the slip amount fluctuation between the calculation intervals is large three times in a row, and this fluctuation is a hunting state, so
As mentioned above with reference to FIG. 4, it is clearly seen that the lock-up clutch 22 is jamming.
The control at the time of determining the yawder proceeds to step 83, where the output duty is set to 0% and the torque converter 13 is set in the converter state even in the S/L region.
It is possible to prevent vibrations and abnormal noises from occurring due to the jamder. Thereafter, control proceeds to step 84, where a flag JFLG indicating the occurrence of a jitter is set to 1.

Once such a jadder occurs, JFLG
= 1, so step 60 in FIG. 8 does not execute the control program in FIG. 9, and the control proceeds to step 53 to maintain the torque converter 13 in the converter state even in the S/L region and eliminate vibrations and abnormal noises caused by the yudder. The occurrence of this can be continuously prevented as long as the S/L region continues.

Note that the slip error ΔX at the time of transition from the C/V region to the S/L region is large, and the calculated value of the PI calculation performed in step 81 based on this slip error is large, resulting in a decrease in the amount of slip between the calculation intervals |A −B|, |B-C|, |C-D| are 10 rpm
As mentioned above, if this is mistakenly determined to be a jitter occurrence, slip control becomes impossible. However, at this time, since the slip error ΔX is larger than 50 rpm, step 75 unconditionally causes normal slip control to be performed by selecting steps 81 and 82, thereby preventing the above-mentioned erroneous judgment. In addition, even though no judder occurs at ΔX≦50rpm, |A-B|>
10rpm, ｜B-C｜＞10rpm, ｜CD｜＞
During slip control such as 10 rpm, misjudgment of the yander can be prevented by determining the direction of change in the amount of slip in steps 79 and 80, as described above.

(6) Effects of the Invention Thus, as described above, in the slip control device of the present invention, when the lock-up clutch 22 generates a yaw, even in the slip control region, the lock-up clutch is released to control the torque converter 13.
Since the torque converter 13 is configured to be in the converter state, the torque converter 13 does not generate vibrations or abnormal noises due to the jitter of the lockup clutch 22 during slip control, and the commercial value of the slip control type torque converter can be increased.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram showing the device of the present invention, Figure 2 is a system diagram showing an embodiment of the device of the present invention, and Figure 3 a.
FIG. 4 is a time chart showing changes in the duty output from the slip control computer that performs the lock-up control of the present invention, FIG. 4 is a change characteristic diagram of control pressure with respect to duty, and FIG.
Figures a and b are explanatory diagrams of the operation of the slip control valve;
Fig. 6 is a characteristic diagram of changes in lockup pressure with respect to duty, Fig. 7 is a block diagram of the slip control computer, Figs. 8 and 9 are flowcharts showing the control program of the slip control computer, and Fig. 10. 11 is a control pattern diagram of the torque converter, FIGS. 11 and 12 are waveform diagrams showing the torque converter output shaft torque and slip amount when no judder occurs and when judder occurs, respectively.
FIG. 3 and FIG. 14 are waveform diagrams showing the slip amount calculation values when no judder occurs and when judder occurs, respectively. DESCRIPTION OF SYMBOLS 1...Power source, 2...Input element, 3...Output element, 4...Slip amount detection means, 5...Lock-up clutch, 6...Clutch control means, 7...
Yadder detection means, 8... Slip control canceling means, 10... Engine (power source), 11... Crankshaft, 12... Flywheel, 13...
Torque converter, 13a...Pump impeller (input element), 13b...Turbine runner (output element), 14...Torque converter output shaft, 17...
...Oil pump, 21...Oil cooler, 22...
... Lockup clutch, 24 ... Lockup chamber, 25 ... Slip control valve, 28 ... Control pressure generation circuit, 29 ... Solenoid valve, 31 ... Slip control computer, 32 ... Engine cooling water temperature sensor, 33 ... ...Engine speed sensor, 34...Gear transmission mechanism output speed sensor, 35...Engine throttle opening sensor, 36...Microprocessor unit (MPU), read-only memory (ROM), 38...Input/output Interface circuit (I/O), 39... A/D converter, 40... Waveform shaping circuit, 41... Amplifier, 42... Gear transmission mechanism, 43... Gear position sensor.

Claims (1)

[Claims] 1.Equipped with an input element driven by a power source and an output element driven by hydraulic oil stirred by the input element, the relative rotation between the input and output elements detected by the slip amount detection means is a set value. A slip control type torque converter is provided with a clutch control means for slidingly coupling a lockup clutch so that the lockup clutch is coupled to the slip control type torque converter, the slip control type torque converter is provided with a clutch control means for slidingly coupling a lockup clutch, and a slip control type torque converter is provided with a slip control type torque converter that detects a swerving of the lockup clutch from the fluctuation state of the relative rotation, and a swerving detecting means for detecting the swerving of the lockup clutch from the fluctuation condition of the relative rotation, and a locking when the swerving is detected by the means. 1. A slip control device for a torque converter, comprising slip control canceling means for activating said clutch control means to cancel sliding engagement of an up clutch.