JP2910325B2 - Control device for lock-up device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lock-up control device.

[0002]

2. Description of the Related Art As a control device of a conventional lock-up device, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 63-172058. The control device of the lock-up device shown here is configured to smoothly engage a lock-up clutch for engaging a pump impeller of a fluid transmission device and a turbine runner. That is, when the lock-up clutch is engaged, a predetermined duty ratio signal is output to the lock-up clutch control duty solenoid. It is controlled accordingly. The duty ratio is the initial value, the value corresponding to the deviation between the target value and the actual value (the value obtained by adding the value proportional to the deviation between the target slip rotation speed and the actual slip rotation speed and the value obtained by integrating the deviation). ) Is added. Therefore, the duty ratio gradually increases from the initial value, and finally becomes a constant value. As the duty ratio increases, the lock-up clutch is gradually engaged (the slip rotation speed gradually decreases).
By doing so, the lock-up clutch can be loosely engaged.

[0003]

However, the control device of the conventional lock-up device as described above has a problem that the engine is blown when the lock-up clutch is engaged at the time of starting. That is, since the conventional control targets the rotational speed difference between the pump impeller and the turbine runner, the target is set at a low speed immediately after the start even though the rotational speed of the turbine runner (that is, the rotational speed of the wheels) is low. In order to realize the rotation speed difference, the rotation speed on the pump impeller side (that is, the engine rotation speed) increases. This increase in the engine rotation speed is perceived as idling, and the driving feeling is not favorable. Even if the target rotational speed difference is set very small,
Accordingly, the deviation becomes very small, so that the rotational speed difference cannot be controlled as desired with stable accuracy.
In addition, the present applicant has solved the above-mentioned problem,
Japanese Patent Application No. 2-92668 discloses a technique of controlling the engine speed at the time of starting such that the target speed is set in advance according to, for example, the engine load. Thus, the above-described problem can be solved. However, if the same control is applied to the case where the lock-up clutch is engaged during running (for example, the case where the lock-up clutch released in the coasting state is engaged when re-accelerated), the following problem occurs. Occurs. That is, the target engine rotation speed is set to be appropriate at the time of starting and is independent of the target input rotation speed (ie, the target turbine rotation speed) on the transmission mechanism side. The engine speed is greatly different from the engine speed, and the deviation of the feedback becomes excessive, so that smooth control cannot be performed. In addition, the engine speed is controlled so as to be the target engine speed while the lock-up clutch is engaged, and is controlled so as to be the target input speed determined by the transmission mechanism after the lock-up clutch is engaged. And the feeling is not good. An object of the present invention is to solve such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by setting a target engine speed in accordance with the engine load at the time of starting and setting the target input speed of the transmission mechanism as the target engine speed during running. Solve. That is, the control device of the lock-up device according to the present invention includes first target engine speed setting means for setting a target engine speed when the lock-up clutch is engaged when starting, and a target engine when the lock-up clutch is engaged during traveling. Second target engine rotational speed setting means for setting a rotational speed, actual engine rotational speed detecting means for detecting an actual engine rotational speed, and first target engine rotational speed setting means or a second target according to the time of starting or running. Feedback control means for outputting an operation signal to the electric actuator so that the difference between the target engine speed set by the engine speed setting means and the actual engine speed becomes zero, The engine speed setting means is configured to output the target engine speed at least according to the engine load. And the second target engine speed setting means sets a target rotation speed of the turbine runner determined by the control device of the transmission mechanism to which the rotation of the turbine runner of the fluid transmission device is input as a target engine rotation speed. It is configured as follows.

[0005]

When the lock-up clutch is engaged at the time of starting, the engine speed is controlled so that the target engine speed is set in accordance with the engine load, thereby preventing the occurrence of engine idling. On the other hand, when the lock-up clutch is engaged during traveling, control is performed by setting the target input rotation speed of the transmission mechanism as the target engine rotation speed. Therefore, the deviation of the engine speed during this control is relatively small, and the feedback control is performed smoothly. In addition, the engine speed does not greatly change before and after the lock-up clutch is engaged.

[0006]

FIG. 2 shows a power transmission mechanism of a continuously variable transmission. The continuously variable transmission includes a fluid coupling 12, a forward / reverse switching mechanism 15, a V-belt type continuously variable transmission mechanism 29, a differential gear 56.
And the like, so that the rotation of the output shaft 10a of the engine 10 can be transmitted to the output shafts 66 and 68 at a predetermined gear ratio and rotation direction. The continuously variable transmission includes a fluid coupling 12 (having a lock-up oil chamber 12a, a pump impeller 12b, a turbine runner 12c, a lock-up clutch 12d, etc.), a rotating shaft 13, a drive shaft 14, and a forward / reverse switching mechanism. 15, drive pulley 16 (fixed cone member 1)
8, drive pulley cylinder chamber 20 (chamber 20a, chamber 20
b), comprising a movable cone member 22, a groove 22a, etc.),
Planetary gear mechanism 17 (sun gear 19, pinion gear 21,
A pinion gear 23, a pinion carrier 25, an internal gear 27, etc.), a V-belt 24, a driven pulley 2
6 (fixed cone member 30, driven pulley cylinder chamber 32,
Driven cone 28, forward clutch 40, drive gear 46, idler gear 48, reverse brake 50, idler shaft 52, pinion gear 54,
Final gear 44, pinion gear 58, pinion gear 60, side gear 62, side gear 64, output shaft 66,
Although it is composed of the output shaft 68 and the like, a detailed description thereof will be omitted. The configuration of the parts not described is described in Japanese Patent Application Laid-Open No.
No. 5353.

FIGS. 3, 4, 5 and 6 show a hydraulic control device for a continuously variable transmission. This hydraulic control device includes an oil pump 10
1. Line pressure regulating valve 102, manual valve 104, shift control valve 106, regulating pressure switching valve 108, step motor 11
0, transmission operation mechanism 112, throttle valve 114, constant pressure regulating valve 116, solenoid valve 118, coupling pressure regulating valve 1
20, a lock-up control valve 122, etc., which are connected to each other as shown in the drawing. The forward clutch 40, the reverse brake 50, the fluid coupling 12, the lock-up oil chamber 12a, the drive pulley The cylinder chamber 20 and the driven pulley cylinder chamber 32 are also connected as shown. Detailed description of these valves and the like will be omitted. The parts for which the description has been omitted are described in the above-mentioned JP-A-61-105353. 3, 4 and 5 indicate the following members. Pinion gear 110a, tank 130, strainer 131, oil passage 132, relief valve 133, valve hole 134, port 13
4a-e, spool 136, land 136a-b, oil passage 138, one-way orifice 139, oil passage 140, oil passage 1
42, one-way orifice 143, valve hole 146, port 1
46a-g, spool 148, lands 148a-e, sleeve 150, spring 152, spring 154,
Transmission ratio transmission member 158, oil passage 164, oil passage 165, orifice 166, orifice 170, valve hole 172, ports 172a-e, spool 174, lands 174a-c,
Spring 175, oil passage 176, orifice 177, lever 178, oil passage 179, pin 181, rod 182,
Lands 182a-b, rack 182c, pin 183, pin 185, valve hole 186, ports 186a-d, oil passage 18
8, oil passage 189, oil passage 190, valve hole 192, port 19
2a-g, spool 194, lands 194a-e, negative pressure diaphragm 198, orifice 199, orifice 2
02, orifice 203, valve hole 204, port 204a
-E, spool 206, lands 206a-b, spring 208, oil passage 209, filter 211, orifice 216, port 222, solenoid 224, plunger 224a, spring 225, valve hole 230, port 23
0a-e, spool 232, land 232a-b, spring 234, oil passage 235, orifice 236, valve hole 2
40, ports 240a-h, spool 242, land 2
42a-e, oil passage 243, oil passage 245, orifice 24
6, orifice 247, orifice 248, orifice 249, choke-type throttle valve 250, relief valve 25
1. Choke type throttle valve 252, pressure holding valve 253, oil passage 25
4, cooler 256, cooler pressure holding valve 258, orifice 2
59, changeover detection switch 278.

FIGS. 7, 8 and 9 show an electronic control unit 30 for controlling the operation of the step motor 110 and the solenoid 224.
Indicates 0. The electronic control unit 300 includes an input interface 311, a reference pulse generator 312, a CPU (central processing unit) 313, a ROM (read only memory) 314,
It has a RAM (random access memory) 315 and an output interface 316, which are connected by an address bus 319 and a data bus 320. The shift control device 300 includes an engine rotation speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, a shift position switch 304, a turbine rotation speed sensor 305, an engine coolant temperature sensor 306, a brake sensor 307, and a switching detection switch 298. Is directly or by the waveform shapers 308, 30
9 and 322 and input through the A / D converter 310, while signals are output to the stepper motor 110 through the amplifier 317 and lines 317a-d, and the solenoid 2
Signals are also output to 24, but a detailed description thereof will be omitted. The configuration of a portion whose description is omitted is described in the above-mentioned Japanese Patent Application Laid-Open No. 61-105353.

The control when the lock-up clutch 12d is engaged is performed by the electronic control unit 300 in accordance with the control flow shown in FIG. First, the engine speed Ne, the vehicle speed VSP, and the throttle opening TVO are read (step 102), and then it is determined whether the vehicle speed VSP is higher than a predetermined vehicle speed VLU (a vehicle speed at which engagement of the lock-up clutch 12d is permitted). (Ibid. 104),
If VSP is greater than VLU, throttle opening T
It is determined whether VO is greater than TLU (10
6) If TVO is higher than TLU, it is determined whether or not engine speed Ne is higher than predetermined value NLU (108). If Ne is greater than NLU, T · NIN is set as the second target engine speed TNe2 (110). T · NIN is a target input rotation speed of the V-belt type continuously variable transmission mechanism 29 (that is, a target turbine rotation speed). Next, the first target engine speed T · Ne1 is set (112). As the first target engine rotation speed T · Ne1, a value that positively correlates to the throttle opening TVO is set in advance as shown in FIG. 11, and is obtained from this value. Next, T ・ Ne1 and T
The magnitude of Ne2 is compared (114), and when T · Ne1 is large, the target engine rotational speed T · Ne is set to the first value.
The target engine speed T · Ne1 is set (11
6) On the other hand, when T · Ne2 is large, T · Ne2 is set as the target engine rotation speed T · Ne (11).
8). Next, a deviation e between the actual engine rotation speed Ne and the target engine rotation speed T · Ne is determined (at 120),
Next, the duty ratio DU is calculated by the equation shown in step 122.
TY is obtained (122). Kp and Ki are feedback constants, and C is an initial value. Next, the solenoid 224 is driven with the duty ratio DUTY thus obtained (124), and the routine returns. If the conditions are not satisfied in steps 104, 106 and 108, the duty ratio DUTY is set to the minimum value M
IN (this corresponds to the disengagement state of the lock-up clutch 12d), and the process returns (126). As a result, the engagement state of the lock-up clutch 12d is controlled by the above control so that the actual engine speed Ne at the time of starting becomes the first target engine speed T · Ne1. Further, the engagement of the lock-up clutch 12d during traveling is determined by the actual engine speed Ne.
Is controlled to the second target engine rotation speed T · Ne2. Therefore, at the time of starting, the engine does not blow out, and since the engine rotation speed which is a sufficiently large value is to be controlled, the control is stable and the accuracy is high. Further, during traveling, the engagement of the lock-up clutch 12d is controlled so that the actual engine rotation speed Ne becomes the target input rotation speed of the continuously variable transmission mechanism. Therefore, the deviation in the feedback control is relatively small, and the controllability is improved.
Further, since the fluctuation of the target engine rotation speed before and after the engagement of the lock-up clutch 12d is small, the fluctuation of the engine rotation speed is small, and the feeling is improved.

[0010]

As described above, according to the present invention, the engine speed is controlled so as to be the first target engine speed corresponding to the engine load at the time of starting, and the target of the speed change mechanism at the time of running is controlled. Since the engine speed is controlled so as to be the second target engine speed determined from the gear ratio, the engine does not blow at the time of starting, and the feedback control during running is smoothly performed. The fluctuation of the engine speed before and after the lock-up clutch is engaged is also reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between components of the present invention.

FIG. 2 is a skeleton diagram of a continuously variable transmission.

FIG. 3 is a diagram showing a left part of a hydraulic control device of the continuously variable transmission.

FIG. 4 is a diagram showing a central portion of a hydraulic control device of the continuously variable transmission.

FIG. 5 is a diagram showing a right part of a hydraulic control device of the continuously variable transmission.

FIG. 6 is a diagram showing an arrangement relationship of FIGS. 3, 4, and 5;

FIG. 7 is a diagram showing a left part of the control unit.

FIG. 8 is a diagram showing a right part of the control unit.

FIG. 9 is a diagram showing an arrangement relationship between FIGS. 7 and 8;

FIG. 10 is a diagram showing a control flow.

FIG. 11 is a diagram showing characteristics of a first target engine rotation speed.

[Explanation of symbols]

 12 Fluid coupling 12b Pump impeller 12c Turbine runner 12d Lock-up clutch 224 Solenoid (electric actuator) 300 Control unit

Claims (1)

(57) [Claims] 1. A control device for a lock-up device having an electric actuator for controlling an engagement capacity between a pump impeller side and a turbine liner side, wherein a first target for setting a target engine rotation speed when the lock-up clutch is engaged at the time of starting. Engine rotation speed setting means, second target engine rotation speed setting means for setting a target engine rotation speed when the lock-up clutch is engaged during traveling, actual engine rotation speed detection means for detecting the actual engine rotation speed, and starting The electric actuator so that the difference between the target engine rotation speed set by the first target engine rotation speed setting means or the second target engine rotation speed setting means and the actual engine rotation speed becomes 0 according to the time or the running time. Feedback control means for outputting an operation signal. The target engine speed setting means sets the target engine speed in accordance with at least the engine load, and the second target engine speed setting means is determined by the control device of the transmission mechanism to which the rotation of the turbine runner of the fluid transmission is input. A control device for a lock-up device, which is configured to set a target rotation speed of a turbine runner as a target engine rotation speed.