JPH0659796B2 - Controller for continuously variable transmission - Google Patents

Description

Description: (a) Field of Industrial Application The present invention relates to a control device for a continuously variable transmission.

(B) Conventional Technology As a conventional control device for a continuously variable transmission, for example, Japanese Patent Laid-Open No.
There is one disclosed in Japanese Unexamined Patent Publication No. 8-180867. That is, in the case of a control device that operates the shift motor by the shift command signal to control the gear ratio, when noise is input to the signal and an error occurs, the error is accumulated and the shift command signal and the actual rotational position of the shift motor are increased. And may not correspond. To prevent this, the shift reference switch detects that the shift motor has reached a predetermined rotation position,
When the shift reference switch is actuated, the shift command signal is always reset by the actuation signal to a state corresponding to the rotational position of the shift motor. This makes it possible to prevent the accumulation of errors.

(C) Problems to be solved by the invention However, since the shift command signal is conventionally calibrated based on the operation of the shift reference switch, if this fails, the resetting of the shift command signal is completed. Will not do. For example, if the gear shift reference switch remains on, the gear shift actuator moves to the side of the minimum gear ratio and it becomes impossible to start. Conversely, if the gear shift reference switch remains off, the gear shift actuator is fixed at the maximum gear ratio. The gear will not be changed.

(D) Means for Solving the Problems In the present invention, when the gear shift command signal is not calibrated within a predetermined time due to a malfunction of the gear shift reference position sensor, the position of the gear shift actuator at that time is set as the reference position. The above problem is solved by calibrating the shift command signal so as to correspond to the reference position. That is, the control device for a continuously variable transmission according to the present invention has a gear shift actuator that operates according to a gear shift command signal, and controls the continuously variable transmission in which the gear ratio is continuously controlled according to the operating state of the gear shift actuator. A gear shift reference position sensor for detecting that the gear shift actuator is at a predetermined signal calibration position, and a gear shift command signal based on a signal from the gear shift reference position sensor in a state corresponding to the signal calibration position. It is applied to a device having a signal calibrating means for operating the speed change actuator to a signal calibrating position in a predetermined case to cause the signal calibrating means to act, according to a command from the initial setting means. If the calibration operation is not completed within a predetermined time after the calibration of the shift command signal is started, the shift actuator at the time when the predetermined time has elapsed is actuated. Failure-time signal calibration means for calibrating the operating position of the shift command signal as a predetermined reference position in a state that corresponds to the reference position, and a.

(E) Action When the signal calibration operation is not completed within a predetermined time after the signal calibration operation is started by the command from the initial setting means,
It is determined that the gear shift reference position sensor is out of order, and the operating position of the gear shift actuator at the time when the predetermined time has elapsed is set as the reference position. At this point in time, the gear shift actuator is operating up to the mechanically movable limit position on the small gear ratio side or the large gear ratio side, for example. The fault signal calibrating means sets the shift command signal to a state corresponding to the mechanical limit position. As a result, it is possible to prevent a large error from occurring between the shift command signal and the actual operating state of the shift actuator.

(F) Embodiment FIG. 2 shows a power transmission mechanism of a continuously variable transmission. This continuously variable transmission includes a fluid coupling 12 and a forward / reverse switching mechanism 1.
5, the V-belt type continuously variable transmission mechanism 29, the differential device 56 and the like are provided, and 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. . This continuously variable transmission includes a fluid coupling 12 (lock-up oil chamber 12a, pump impeller 12
b, the turbine runner 12c, etc.), the rotary shaft 1
3, drive shaft 14, forward-reverse switching mechanism 15, drive pulley 16
(Fixed cone plate 18, drive pulley cylinder chamber 20 (chamber 2
0a, chamber 20b), movable cone plate 22, groove 22a, etc.), planetary gear mechanism 17 (sun gear 19, pinion gear 21, pinion gear 23, pinion carrier 25,
Internal gear 27, etc.), V belt 24, driven pulley 26 (composed of fixed conical plate 30, driven pulley cylinder chamber 32, movable conical plate 34, etc.), driven shaft 28,
Forward clutch 40, drive gear 46, idler gear 4
8, a reverse brake 50, an idler shaft 52, a pinion gear 54, a final gear 44, a pinion gear 58, a pinion gear 60, a side gear 62, a side gear 64, an output shaft 66, an output shaft 68, etc. The detailed description of is omitted. Regarding the structure of the part of which description is omitted, Japanese Patent Application No.
9-226706.

FIG. 3 shows a hydraulic control device for a continuously variable transmission. This hydraulic control device includes an oil pump 101, a line pressure regulating valve 10
2, a manual valve 104, a shift control valve 106, an adjusting pressure switching valve 108, a shift motor (shift actuator) 110,
Gear change operation mechanism 112, throttle valve 114, constant pressure regulating valve 116, solenoid valve 118, coupling pressure regulating valve 12
0, a lock-up control valve 122, etc., which are connected to each other as shown in the figure, and also a forward clutch 40, a reverse brake 50, a fluid coupling 12, a lock-up oil chamber 12a, a 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 omitted from the explanation are the aforementioned Japanese Patent Application No. 5
9-226706. Each reference numeral in FIG. 3 indicates the following member. Pinion gear 110
a, tank 130, strainer 131, runner 132, relief valve 133, valve hole 134, ports 134a-e, spool 136, lands 136a-b, runner 138, one-way orifice 139, runner 140, runner 142, One-way orifice 143, valve hole 146, ports 146a-g,
Spool 148, lands 148a-e, sleeve 15
0, spring 152, spring 154, pressing member 1
58, oil passage 164, oil passage 165, orifice 166, orifice 170, valve hole 172, ports 172a-e, spool 174, lands 174a-c, spring 17
5, oil passage 176, orifice 177, lever 178, oil passage 179, pin 181, rod 182, land 182a
-B, rack 182c, pin 183, pin 185, valve hole 186, ports 186a-d, oil passage 188, oil passage 18
9, oil passage 190, valve hole 192, ports 192a-g, spool 194, lands 194a-e, negative pressure diaphragm 198, orifice 199, orifice 202, orifice 203, valve hole 204, ports 204a-e, spool 206, land 206a-b, spring 208, oil passage 209, filter 211, orifice 216, port 222, solenoid 224, plunger 224a, spring 225, valve hole 230, port 230a-e, spool 232, land 232a-b, spring 23.
4, oil passage 235, orifice 236, valve hole 240, ports 240a to h, spool 242, land 242a to
e, oil passage 243, oil passage 245, orifice 246, orifice 247, orifice 248, orifice 249,
Choke type throttle valve 250, relief valve 251, choke type throttle valve 252, pressure holding valve 253, oil passage 254, cooler 256, cooler pressure holding valve 258, orifice 25
9. Changeover detection switch 278.

Next, the shift control device 300 that controls the operation of the step motor 110 and the solenoid 224 will be described. As shown in FIG. 4, the shift control device 300 includes an engine speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, and a shift position switch 3.
04, turbine rotation speed sensor 305, changeover detection switch 298 (shift reference position sensor), engine cooling water temperature sensor 306, and brake sensor 307. Engine speed sensor 30
1 detects the engine rotation speed from the ignition pulse of the engine, and the vehicle speed sensor 302 detects the vehicle speed from the rotation of the output shaft of the continuously variable transmission. The throttle opening sensor 303 detects the throttle opening of the engine as a voltage signal. The shift position switch 304 is
The position of the manual valve 104 at P, R, N, D, L is detected. Turbine rotation speed sensor 305
Detects the rotational speed of the turbine shaft of the fluid coupling 12. The change detection switch 298 is a switch that is turned on when the rod 182 of the speed change operation mechanism 112 further moves beyond the position where the gear ratio is largest (that is, in the overstroke region). The engine cooling water temperature sensor 306 generates a signal when the temperature of the engine cooling water is below a certain value. The brake sensor 307 is
Detects if the vehicle brakes are used.
Engine speed sensor 301, vehicle speed sensor 302
The signals from the turbine rotation speed sensor 305 are sent to the input interface 311 through the waveform shapers 308, 309 and 322, respectively, and the voltage signal from the throttle opening sensor 303 is converted into a digital signal by the AD converter 310 and input. Interface 3
Sent to 11. The shift control device 300 includes an input interface 311, a CPU (central processing unit) 313, a reference pulse generator 312, and a ROM (read only memory) 3.
14, 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 reference pulse generator 312 generates a reference pulse for operating the CPU 313. The ROM 314 stores a program for controlling the step motor 110 and the solenoid 224, and data necessary for the control. The RAM 315 temporarily stores information from each sensor and switch, parameters necessary for control, and the like. The output signal from the shift control device 300 is the amplifier 31.
7 to the step motor 110, and also to the solenoid 224.

Next, specific control contents of the step motor 110 and the solenoid 224 performed by the shift control device 300 will be described.

A control routine for the step motor 110 and the solenoid 224 is shown in FIGS. First, the computer is initialized, that is, the timers TM ₁ and TM ₂ are settled (step 501), then the shift position is read from the shift position switch 304 (step 502), and then steps 902 and 904.
In determining whether or not and switching the detecting switch 298 pulse number P _A of the current stepper motor 110 (the shift command signal of the shift actuator) is 0 is on, even though a P _A = 0 Changeover detection switch 2
If 98 is off, the initialization completion flag is cleared (at step 906) and the routine proceeds to step 908. In cases other than the above, the process proceeds to step 908 without clearing the initialization completion flag. In steps 908, 910 and 912, P ₁ is set as the value of P _A when the change detection switch 298 is on and the EDGE flag is set. Step 91 is to proceed to steps 908, 910 and 912.
4 and the operation of step 916, the changeover detection switch 2
Only when 98 goes from off to on. With this, when the changeover detection switch 298 is turned on,
P _A is calibrated to have a corresponding number of pulses P ₁ . That is, the initial setting is performed. Then step 9
18, the vehicle speed V is read, and then the vehicle speed V is smaller than a predetermined small value V ₁ (id.
0), and whether or not the initialization end flag is set (at 922). If the vehicle speed V is lower than V ₁ and the initialization end flag is not set, the sixth
The process proceeds to step 924 shown in the figure, and when the vehicle speed V is V ₁ or more and the initial setting flag is set, the process proceeds to step 504 and the steps shown in FIG.

At steps 924, 926 and 928 shown in FIG. 6, whether the changeover detection switch 298 is on or not,
Whether the BSTP flag for determining whether to reverse the step motor to the downshift side is set, and P
It is determined whether or not _A = 0, and the changeover detection switch 29
8 is on, BSTP flag is set,
When P _A = 0, the initialization completion flag is set (at step 930). Next, the BSTP flag is cleared (see 93
2), proceed to step 504 onward in FIG. That is,
In the case of proceeding to steps 924 → 926 → 928 → 930 → 932, the pulse number P _A is set to 0 when the change detection switch 298 is turned on, and the initial setting is completed. In step 924, the changeover detection switch 298
Is off, after setting the BSTP flag (see
4) Also, if P _A = 0 is not established in step 928, the process immediately proceeds to step 936, whether the value of the timer TM ₁ is larger than a predetermined value T _O , that is, whether a predetermined time has elapsed from the start of initialization. To judge. If the predetermined time T _O has not elapsed, the process proceeds to step 620 and thereafter shown in FIG. 8 to move the step motor 110 in the downshift direction. If the predetermined time T _O has elapsed in step 936, the initialization end flag is set (see
38), the value of P _A is set to 0 (at 940), the BSTP flag is settled (at 942), the first setting first error flag is set (at 944), and the process proceeds to step 504 and thereafter. If the BSTP flag is not set in step 926, it is determined whether the value of the timer TM ₂ is larger than the predetermined value T ₁ , that is, whether the predetermined time T ₁ has elapsed from the start of the initialization (the same). 946), if the time T ₁ has not elapsed, the process proceeds to step 632 shown in FIG. 8 to move the step motor 110 in the upshift direction. When the predetermined time T ₁ has passed in step 946, the number of pulses P _X at that time is set as P _A (see 94
8), and set the second error flag for initial setting (see
0), the initial setting end flag is set (at step 952), and the process proceeds to step 504 and thereafter.

In step 504 shown in FIG. 7, it is judged whether or not the shift position is in the traveling position (that is, the D, L or R range) (step 504), and if it is not in the traveling position, the duty ratio of the solenoid 224 is set to 0. Set to (50
6), and proceeds to step 630 described later. When the shift position is in the traveling position, the throttle opening sensor 30
3, the throttle opening TH is read (step 508), the vehicle speed V is read from the vehicle speed sensor 302 (step 510), and the engine speed N _E is read from the engine speed sensor 301.
Is read (512), and the turbine rotational speed Nt is read from the turbine rotational speed sensor 305 (514). Next, the difference N _D between the engine rotation speed N _E and the turbine rotation speed Nt is calculated (step 516), and then the lockup ON vehicle speed V _ON and the lockup OFF vehicle speed V
A search for _OFF is performed (step 518). The lock-up on vehicle speed V _ON and the lock-up off vehicle speed V _OFF have predetermined characteristics stored as a function of the vehicle speed V and the throttle opening TH. Next, it is judged whether or not the lockup flag LUF is set (at step 520), and the flag L is set.
When UF is not set, it is determined whether the actual vehicle speed V is higher than the lockup ON vehicle speed V _ON (the same 5
22), in the case of V> V _ON to set the N _D -NM ₁ as e (the 524). Nm ₁ is the engine speed N _E
Is a target value of the deviation between the turbine rotation speed Nt and the turbine rotation speed Nt. Then, the feedback control gain G ₁ is searched based on the value of e (step 526). Next, it is judged whether N _D is smaller than a predetermined small value N _O (at 528).
N _O is a rotation difference for which feedback control is performed when N _D is larger than this and feed forward control is performed when N _D is smaller than this. When N _D <N _O , a value obtained by adding a small value α% to the current duty ratio is set as a new duty ratio (at 530), and then it is determined whether the duty ratio is less than 100% ( 532), if it is less than 100%, the operation proceeds to step 602 described later, while if it is 100% or more, the duty ratio is set to 100% (534) and then the lockup flag LUF is set (536). ), Similarly, the process proceeds to step 602 described later (that is, feedforward control is performed). N _D in step 528 above
When ≧ N _O , the deviation e and the feedback gain G ₁
The duty ratio is determined based on the above (step 538), and the routine proceeds to step 602 (that is, feedback control is performed). If V ≦ V _ON in step 522, the duty ratio is set to 0% (at 540), and then the lockup flag LUF is cleared (at 542).
This releases the operation of the lockup mechanism. Further, in step 520 described above, the lockup flag LUF
Is set, it is determined whether the vehicle speed V is lower than the lockup off vehicle speed V _OFF (step 544), and V
<V _OFF proceeds to steps 540 and 542 (lockup release), and when V ≧ V _OFF , the duty ratio is set to 100% (step 546) (this holds the lockup state) ).

Steps 532, 536, 538, 542 and 5 above
From 46, the process proceeds to step 602. In step 602, it is determined whether the vehicle speed V is smaller than a predetermined small value V _O (for example, 2 to 3 km / h, which is smaller than the above-mentioned V _ON and V _OFF ), and V <V _O creep control is performed in the case of, so that the shift control is performed in the case of V ≧ V _O. First, in the case of V <V _O determines whether the throttle opening TH is smaller than a predetermined small value TH _O (same 604), sets the duty ratio to 0% when the throttle is not in the idle state Shi (same as 60
6) (By this, the forward clutch 40 is completely engaged), the target pulse number P _D of the step motor 110 is set to P ₁
Is set to (step 608). After step 608, the routine proceeds to step 630, where control is performed so that the actual position of the step motor 110 becomes the position of the pulse number P ₁ . If the throttle is in the idle state in step 604, it is judged whether or not the changeover detection switch 298 is on (step 610). If it is on, the difference between the engine speed N _E and the turbine speed Nt is determined. The difference between N _D and the target deviation Nm ₂ is set as e (at 612), and the feedback gain G ₂ is searched based on the value of this e (at 614). Then, the duty ratio is set based on the deviation e and the feedback gain G ₂ (at the same step 61).
6) Next, the target pulse number P _D is set to 0 (step 618) and the step motor drive signal is output (step 63).
6), and also outputs a solenoid drive signal (63)
8). In step 610, the changeover detection switch 298 is selected.
When is off, the stepping motor drive signal is moved in the downshift direction (at 620), and a value obtained by subtracting 1 from the current pulse number P _A is newly set as the pulse number P _A (at 622). Outputs the motor drive signal (same as 6
36), and outputs a solenoid drive signal (at 638).

Shift position in the case of V ≧ V _O at step 602 described above, it is judged whether the D range (the 62
4) If it is in the D range, the D range shift pattern is searched (at 626), and if it is determined that it is not at the D range (at 624), it is determined that it is in the L range (at 639). Performs an L range shift pattern search (step 628) and, if it is determined in step 639 that the L range shift pattern is not in the L range, searches for an R range shift pattern (step 640), thereby obtaining the target pulse. Number P
Determine _D. Next, the searched target pulse number P _D
And the actual pulse number P _A are compared (at 630),
When P _D = P _A , steps 636 and 638 are performed as they are.
Then, the step motor drive signal and the solenoid drive signal are output. If P _A <P _D , the step motor drive signal is moved in the upshift direction (at 632), and then the current pulse number P _A plus 1 is newly set as the pulse number P _A (at the same time). 634), the step motor drive signal and the solenoid drive signal are output in steps 636 and 638. In the case of P _A <P _D to move the stepper motor drive signal to downshift direction (the 620), then sets the obtained by subtracting 1 from the current number of pulses P _A as the new pulse number P _A (same 622) and proceeds to steps 636 and 638 to output the step motor drive signal and the solenoid drive signal.

Eventually, the following control is performed by the control routines 902 to 954. If the changeover detection switch 298 remains off after the initial setting is started (steps 924 → 934) or if the changeover detection switch 298 is turned on but P _A does not become 0 (step 924). (→ 926 → 928 → 936), that is, when the change detection switch 298 does not change from OFF to ON even after a predetermined time T _O has elapsed from the start of initial setting, or when P _A = 0 does not occur even if the change detection switch 298 changes. At that time, the pulse number P _A is calibrated to 0 and the error flag is set because the initial setting is completed (step 936).
→ 944). The predetermined time T _O stepper motor 110 is a sufficient time to operate the full stroke. Since the step motor 110 proceeds from between step 936 until the predetermined time T _O elapses in step 620 operates the downshift direction, after T _O time step motor 1
10 has reached the mechanical movable limit position on the high gear ratio side,
P _A = 0 will be set corresponding to this position,
The pulse number P _A and the operating position of the step motor 110 substantially correspond to each other. Further, if the changeover detection switch 298 remains on after starting the initial setting (step 924 → 926 → 946), that is, the changeover detection switch 298 does not turn off even after the elapse of the predetermined time T _1. In this case, the number of pulses P _A is set to a predetermined value P _X and the error flag is set because the initial setting is completed (step 946 → 954). The predetermined time T ₁ is sufficient for the step motor 110 to operate the entire stroke. Until the predetermined time T ₁ elapses, the process proceeds from step 946 to step 632 and the step motor 1
Since 10 operates in the upshift direction, the step motor 110 reaches the mechanical movable limit position on the side of the minimum gear ratio at the time point when T ₁ time has elapsed. Since the value of P _X is set in advance so as to correspond to this mechanical limit position, the pulse number P _A and the operating position of the step motor 110 substantially correspond to each other. Therefore, regardless of whether the changeover detection switch 298 has a failure in the ON state or a failure in the OFF state, the initial setting can be performed for the time being and the subsequent operation can be continued.

The initial setting first and second flags set in steps 944 and 950 described above can be used as signals for failure monitoring, and the monitor lamp is turned on by determining when these flags are set. It is possible to improve repair serviceability by adding the flow of. Note that these flags may be settled as appropriate by turning off the power or resetting the switches.

(G) Effect of the Invention As described above, according to the present invention, when the initial setting of the shift command signal is not completed within the predetermined time, the shift command signal is generated based on the position of the shift actuator at the time when the predetermined time has elapsed. Since the calibration is performed, the shift control can be continued without causing a large error even if the shift reference position sensor fails.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between components of the present invention, FIG. 2 is a diagram showing a power transmission mechanism of a continuously variable transmission, FIG. 3 is a diagram showing a hydraulic control device of the continuously variable transmission, and FIG. The figure shows a shift control device for a continuously variable transmission, and FIGS. 5, 6, 7 and 8 show a control routine. 110 ... Gear change actuator (step motor), 29
8: Gear shift reference position sensor (switch detection switch).

Claims (1)

[Claims] 1. A control device for a continuously variable transmission, comprising: a gear shift actuator which operates in response to a gear shift command signal; wherein a gear ratio is continuously controlled in accordance with an operating state of the gear shift actuator, wherein the gear shift actuator has a predetermined size. Of the gear shift reference position sensor for detecting that it is in the signal calibration position, and signal calibration means for calibrating the gear shift command signal to a state corresponding to the signal calibration position based on the signal from the gear shift reference position sensor; In a control device for a continuously variable transmission, further comprising: initial setting means for actuating the speed change actuator to a signal calibration position to operate the signal calibration means, and the calibration of the speed change command signal is started by a command from the initial setting means. If the calibration operation is not completed within a predetermined time from, the operating position of the gear shift actuator at the time when the above predetermined time has elapsed is set to the predetermined reference position. And a failure signal calibrating means for calibrating the shift command signal to a state corresponding to the reference position.