JPH0645318B2 - 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 shift control device for a continuously variable transmission, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. 58-170958. The shift control device of the continuously variable transmission is configured to start discharging the hydraulic pressure on the drive pulley side at the same time when the brake is depressed to start shifting to the higher gear ratio side. Also,
Japanese Unexamined Patent Publication (Kokai) No. 58-170959 discloses a shift control device that starts shifting to the higher gear ratio side when the throttle is fully closed. These shift control devices obtain the engine braking effect by predicting the need of engine braking from a specific driving condition (that is, using the brake or fully closing the throttle) and immediately starting the shift to the higher gear ratio side. It is something to try. This makes it possible to obtain the engine braking effect relatively quickly even in the case of a continuously variable transmission having a slow speed change.

(C) Problems to be Solved by the Invention In the conventional control device for a continuously variable transmission as described above, although the shift response to the higher gear ratio side is improved to some extent, the operating speed of the sudden braking is increased. Since the output speed does not rotate when the wheels are locked by applying a sudden brake, for example, the detected vehicle speed becomes 0 and the gear ratio tends to change to a large side. . However, when the output shaft does not rotate and the pulley does not rotate, the gear shift response is particularly poor.Therefore, if the accelerator pedal is pressed and the throttle is opened after the gear shift is started, the gear ratio is still higher. Since the gear is being changed and the oil is being discharged from the drive pulley, the frictional force does not sufficiently act on the V-belt. As a result, the V-belt slips, power cannot be transmitted, and the V-belt wears. In addition, since the downshift is started in anticipation of the need for engine braking, a shift to the higher gear ratio side is performed even when the driver does not desire, which causes a strange feeling. The present invention aims to solve such problems.

(D) Means for Solving the Problems The invention of the present application is to drive a gear shift actuator to a position corresponding to a predetermined gear ratio at the same time as the brake operating state is released or the throttle is opened. Solves the above problems. That is, the control device for a continuously variable transmission according to the first aspect of the present invention includes a sudden braking detecting unit that can detect a sudden braking state, a brake release detecting unit that detects a release of the brake, and a sudden braking state after the sudden braking state is detected. When the brake is released, it is detected by the brake release pulley state detection means that calculates or detects the position of the movable cone plate of the drive pulley or the driven pulley, and the brake release pulley state detection means at the same time when the brake is released. And a post-brake shift actuator driving means for driving the shift actuator at a gear ratio position corresponding to the pulley state.

A control device for a continuously variable transmission according to a second aspect of the present invention includes a sudden braking detecting unit capable of detecting a sudden braking state, a throttle opening detecting unit detecting an throttle opening state of an engine,
Throttle open state detection means for calculating or detecting the position of the movable conical plate of the drive pulley or driven pulley when the throttle is opened after the sudden braking state is detected, and the throttle open pulley at the same time when the throttle is opened. And a post-throttle shift gear motor driving means for driving the gear shift actuator at a gear ratio position corresponding to the pulley state detected by the state detecting means.

(E) Action When the vehicle brakes suddenly act and the wheels are locked while the vehicle is running in a state where the gear ratio is relatively small, the detected vehicle speed becomes 0, so that the gear ratio increases rapidly. A shift command is issued and the shift actuator (motor) rotates. As a result, the spool of the shift control valve moves via the link, and the hydraulic pressure acting on the drive pulley begins to be discharged.
Although the movable cone of the drive pulley moves as the hydraulic pressure decreases, the movement of the movable cone causes a slight time delay after the decrease in hydraulic pressure. Therefore, even if the hydraulic pressure in the drive pulley cylinder chamber is almost zero, the drive pulley The movable cone plate of is still in the process of moving. When the operation of the brake is released in this state, this is detected by the brake release detecting means, and this signal activates the pulley state detecting means during brake release. The brake release pulley state detection means detects the state of the pulley when the brake is released, that is, the gear ratio. This is calculated, for example, based on the gear ratio position of the transmission motor when the sudden braking is started and the elapsed time from the sudden braking start to the brake release.
This calculation is based on the fact that the moving speed of the movable cone plate of the pulley is almost constant during a sudden shift to the higher gear ratio side. The state of the pulley at the time of releasing the brake, that is, the position of the movable conical plate of the drive pulley may be detected by providing a position sensor for detecting the position of the movable conical plate. After releasing the brake, the shift motor driving means rotates the shift motor to a position corresponding to the gear ratio detected by the brake release time pulley state detecting means at the same time when the brake operation is released. As a result, the shift control valve also comes to a position corresponding to this gear ratio, and a predetermined hydraulic pressure is supplied to the drive pulley cylinder chamber. When the engine throttle is opened in this state, the drive pulley and driven pulley are in a gear ratio that should be set when the brake is released and the wheels start to rotate. Since tension is applied to the V-belt, the V-belt does not slip. Further, since the gear ratio is also the gear ratio in the traveling condition, the gear is not changed at the same time when the throttle is opened, and the re-driving is started without causing a feeling of strangeness.

The above is the description of the operation of the first invention, but substantially the same operation can be obtained for the second invention. However, in the case of the second invention, the shift motor is driven to the position corresponding to the predetermined gear ratio at the same time when the throttle is opened.
In this case, it is possible to drive the shift motor to a position slightly higher than the predetermined gear ratio at the same time as the brake is released.

(F) Embodiment (Embodiment of the first invention) 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, manual valve 104, shift control valve 106, adjusting pressure switching valve 108, shift motor (step motor) 110, shift operating mechanism 112, throttle valve 114, constant pressure pressure regulating valve 1
16, a solenoid valve 118, a coupling pressure regulating valve 120, a lockup control valve 122, etc., which are connected to each other as shown in the drawing, and the forward clutch 4
0, reverse brake 50, fluid coupling 12,
The lockup oil chamber 12a, the drive pulley 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. Regarding the part of which description is omitted, the above-mentioned Japanese Patent Application No. 59-
No. 226706. Each reference numeral in FIG. 3 indicates the following member. Pinion gear 110a, tank 130, strainer 131, oil passage 132, relief valve 133, valve hole 134, ports 134a to e, spool 136, lands 136a and b, oil passage 138, one-way orifice 139, oil passage 140, oil passage. 142, one-way orifice 143, valve hole 146, ports 146a-g, spool 148, lands 148a-e, sleeve 150, spring 152, spring 154, gear ratio detection member 15
8, 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 1
79, pin 181, rod 182, land 182a ...
b, rack 182c, pin 183, pin 185, valve hole 1
86, ports 186a-d, oil passage 188, oil passage 189,
Oil passage 190, valve hole 192, ports 192a-g, spool 194, lands 194a-e, negative pressure diaphragm 19
8, orifice 199, orifice 202, orifice 203, valve hole 204, ports 204a to e, spool 2
06, land 206a-b, spring 208, oil passage 2
09, filter 211, orifice 216, port 2
22, solenoid 224, plunger 224a, spring 225, valve hole 230, ports 230a-e, spool 232, lands 232a-b, spring 234, oil passage 235, orifice 236, valve hole 240, port 24.
0a-h, spool 242, lands 242a-e, oil passage 243, oil passage 245, orifice 246, orifice 2
47, orifice 248, orifice 249, choke type throttle valve 250, relief valve 251, choke type throttle valve 252, pressure holding valve 253, oil passage 254, relief valve 255, cooler 256, cooler pressure holding valve 258, orifice 259, changeover detection switch 278. The relief valve 255 is provided in the oil passage 176 communicating with the drive pulley cylinder chamber 20.

FIG. 4 shows a shift control device 300 that controls the operations of the step motor 110 and the solenoid 224. The shift control device 300 includes an input interface 311, a reference pulse generator 312, a CPU (central processing unit) 313, and a ROM.
(It has a read only memory 314, a RAM (random access memory) 315, and an output interface 316, which are connected by an address bus 319 and a data bus 320. This shift control device 30
Reference numeral 0 indicates an engine speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, a shift position switch 304, a turbine speed sensor 30.
5, the signals from the engine cooling water temperature sensor 306, the brake sensor 307 and the changeover detection switch 298 are input directly or through the waveform shapers 308, 309 and 322 and the AD converter 310, while stepping through the amplifier 317 and the lines 317a-d. A signal is output to the motor 110 and a signal is also output to the solenoid 224, but detailed description thereof will be omitted. Incidentally, regarding the configuration of the part whose description is omitted, the above-mentioned Japanese Patent Application No.
-226706.

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 shift position is read from the shift position switch 304 (step 502), it is determined whether the shift position is in the traveling position (D, L or R range) (step 504), and if it is not in the traveling position (P). Or N range) solenoid 2
The duty ratio of 24 is set to 0 (step 506) and the process proceeds to step 630 (FIG. 8) described later. When the shift position is in the traveling position, the throttle opening sensor 303
The throttle opening TH is read from the vehicle speed (508), the vehicle speed Vn is read from the vehicle speed sensor 302 (510), and it is determined whether the vehicle speed Vn is 10 km / h or more (8).
02), if Vn ≧ 10 km / h, step 804
Step 512 (6th
Figure). When Vn <10 km / h, the turbine rotation speed Nt is read (804) and then it is determined whether the turbine rotation speed Nt is 600 rpm or higher (806). If Nt ≧ 600 rpm, the process immediately proceeds to step 512, and if Nt <600 rpm, Vd = V−Vn is calculated (808). V
Is the vehicle speed in the previous routine, and Vn is the vehicle speed in this routine, so Vd indicates the rate of change of the vehicle speed. Next, the Vn read this time is set to V (step 810), and then it is determined whether the throttle opening TH is larger than a predetermined small value THo (step 81).
2) If TH ≧ THo, sudden braking determination flag F
BR is set to 0 (step 814) and the process proceeds to step 512. When TH <THo, it is determined whether the flag FBR is set to 1 (step 816) and the flag FBR is set.
When BR is set, a value obtained by adding 1 to the timer value Tb is set as a new timer value Tb.
8) and proceeds to step 512. When the flag FBR is not set, Vd indicating the changing speed of the vehicle speed is the predetermined value Vd.
It is determined whether or not it is greater than or equal to o (at 820). Vd ≧
In the case of Vdo (that is, a sudden braking condition in which the vehicle speed is rapidly reduced), the flag FBR is set to 1 (82
2) Then, the timer value Tb is settled to 0 (step 82)
4) Next, the current pulse number P _A of the step motor drive signal is set and stored as P _H (step 826). In addition,
If Vd <Vdo in step 820, the process directly proceeds to step 512.

It reads the engine rotational speed _{N E} from step 512 (FIG. 6), the engine rotational speed sensor 301. Then
Difference N between the engine rotational speed N _E and the turbine rotational speed Nt
_D is calculated (step 516), and the lock-up on vehicle speed V _ON and the lock-up on vehicle speed V _OFF are searched (step 518). The lock-up on vehicle speed V _ON and the lock-up off vehicle speed V _OFF are stored as characteristics of the function shown in FIG. 9 as a function of the vehicle speed V and the throttle opening TH. Next, it is determined whether or not the lockup flag LUF is set (at 520), and if the flag LUF is not set, it is determined whether or not the actual vehicle speed V is higher than the lockup ON vehicle speed V _ON ( Same 52
2), in the case of V> V _ON to set the _N D -NM ₁ as e (the 524). Note that Nm ₁ is the engine speed N
It is a target value of the deviation between _E and the turbine rotation speed Nt. Then, based on the value of e, the feedback control gain G ₁
Is searched (at 526). Then, it is determined whether N _D is smaller than a predetermined small value No (step 52).
8). No is a rotation difference in which feedback control is performed when N _D is larger than this, and feedforward control is performed when N _D is smaller than this. N _D
In the case of <No, a value obtained by adding a minute value α% to the current duty ratio is set as a new duty ratio.
0), then it is judged whether the duty ratio is less than 100% (step 532), and if it is less than 100%, the process proceeds to step 602 (FIG. 8) described later, while 100%.
In the above cases, the duty ratio is set to 100% (see 5 above).
34), then the lockup flag LUF is set (step 536), and similarly, the process proceeds to step 602 described later (that is, feedforward control is performed). If N _D ≧ No in step 528, the duty ratio is determined based on the deviation e and the feedback gain G ₁ (step 538) and the process 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, Step 5 when the vehicle speed V is determined whether the lock-up off vehicle speed V _OFF is smaller than the (same 544), V <V _OFF when it is configured as a lock-up flag LUF in step 520 described above
40 and 542 (lockup release), V ≧
In the case of V _OFF , the duty ratio is set to 100% (step 546) (this holds the lockup state).

Next, at step 840 (FIG. 7), the flag FBR is set to 1
If it is not set, the process proceeds to step 602. If it is set, the signal from the brake sensor 307 is read (step 842), and the brake is activated. determines whether there (at 844), the value when the brake is applied the process proceeds to step 602, and when the brake is not operating by subtracting a multiplied by the constant k in the timer value Tb from P _H Is set to Ps (same 846), then Tb is set to 0 (same 848), and the value of Ps obtained by the above calculation is P
₁ (this P ₁ corresponds to the maximum gear ratio position) is determined (step 850). Ps> For _{P 1} to (if not the maximum gear ratio) to set the value of Ps as the value of _{P D} (same 852), a flag FSPU 1
(Step 854), and step 630 (eighth step) described later.
Figure). If Ps ≦ P ₁ in step 850 (that is, if the maximum gear ratio is achieved), the flag FBR is cleared to 0 (step 856) and the process proceeds to step 602.

From steps 840, 844 and 856, the process proceeds to step 602 and subsequent steps shown in FIG. First, in step 602, the vehicle speed V is a predetermined small value Vo (for example, 2 to 3 km /
h, which is a value smaller than V _ON and V _{OFF as} shown in FIG. ), It is determined that V <V
When o, creep control is performed, and when V ≧ Vo, shift control is performed. First, V <Vo
In the case of, the throttle opening TH is a predetermined small value THo
If the throttle is not idle, the duty ratio is set to 0% (step 606).
Is completely engaged), and the target pulse number P _D of the step motor 110 is set to P ₁ (step 608). Here, as shown in FIG. 10, the pulse number P ₁ of the step motor 110 corresponds to the gear ratio maximum position (that is, the boundary position between the gear shift region and the overstroke region). 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 the changeover detection switch 298 is on (step 61).
0), when it is on, the difference N _D between the engine rotation speed N _E and the turbine rotation speed Nt and the difference between the target deviation Nm ₂ are set as e (step 612), and based on the value of this e. The feedback gain G ₂ is searched (at 614).
Next, the duty ratio is set based on the deviation e and the feedback gain G ₂ (at 616), then the current pulse number P _A is set at 0 (at 618), and the step motor drive signal is output (at 636). Also, a solenoid drive signal is output (step 638). Switch 298 out switching換検in step 610 described above to move the stepper motor drive signal to downshift direction when off (the 620), a new pulse number P _A of those obtained by subtracting 1 from the current number of pulses P _A (Step 622), the step motor drive signal is output (step 636), and the solenoid drive signal is output (step 638).

If V ≧ Vo in step 602, it is determined whether or not the shift position is in the D range (step 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 target pulse number P retrieved
_D is compared with the actual pulse number P _A (63
0), and when P _D = P _A , the plug FSPU is settled to 0 (step 902) and the process proceeds to steps 636 and 638.
The step motor drive signal and the solenoid drive signal are output. When P _A <P _D , it is determined whether or not the flag FSPU is set (step 904). If it is set, the step motor drive signal is moved in the upshift direction (step 906) and the current _{A value obtained} by adding 2 to the pulse number P _A is newly set as the pulse number P _A (
8) In step 636 and step 638, the step motor drive signal and the solenoid drive signal are output. If the flag FSPU is not set in step 904, the step motor drive signal is moved in the upshift direction (at step 632), and then the current pulse number P _A plus 1 is newly added to the pulse number P _A. Set as
4) The step motor drive signal and the solenoid drive signal are output in steps 636 and 638. When P _A > P _D , the flag FSPU is cleared to 0 (at 910), the step motor drive signal is moved in the downshift direction (at 620), and then 1 is subtracted from the current pulse number P _A. Is set as a new pulse number P _A (at 622),
In step 636 and 638, the step motor drive signal and the solenoid drive signal are output.

Eventually, the following control will be performed by steps 602-638. That is, when the vehicle speed is very low, the throttle is idle, and the changeover detection switch 298 is on, the solenoid 22 is controlled so that the fluid coupling 12 has a predetermined slippage.
4 controls the transmission torque capacity of the forward clutch 40 (creep control, steps 612 to 618). When the vehicle speed is low but the throttle is not in the idle state, the step motor 110 is operated to the pulse number P ₁ position. , The lockup control can be started immediately. As described above, by controlling the throttle pressure during low vehicle speed idling to control the transmission torque capacity of the forward clutch 40, it is possible to make the vehicle slowly creep. In cases other than the above, the step motor 1
The gear ratio is controlled by 10.

Next, a description will be given of the control that is performed when the sudden braking is activated to such an extent that the wheels are locked, the brake is then released, and the accelerator pedal is depressed (that is, the throttle is opened). Sudden braking is activated during driving,
When the vehicle speed rapidly decreases, the flag FBR is set, the timer value Tb is settled, and the pulse signal P _A at that time is stored as P _H (step 820).
→ 822 → 824 → 826). Next, in the next routine, the routine proceeds from step 816 to step 818, and the timer value Tb is measured. Therefore, the timer value Tb continues to be measured while the sudden braking state continues. During this period, the detected vehicle speed Vn is extremely low,
The step motor drive signal commands the rotation to the high gear ratio side, the shift control valve 106 moves to the high gear ratio side, and the hydraulic pressure in the drive pulley cylinder chamber 20 starts to be rapidly discharged. In response to this, the drive pulley 16 and the driven pulley 26 try to shift to a state where the gear ratio is high. When the brake operation is released in this state, a value obtained by multiplying the timer value Tb at that time by a constant k is subtracted from P _H , and this is set as Ps (steps 844 → 846).
The calculated Ps is set as the target pulse number P _D (step 852), and the actual position of the step motor 110 is controlled so as to reach the value of this P _D , so the step motor 110 corresponds to the value of Ps. Rotate to the position you want. The gear ratio indicated by the value of Ps corresponds to the gear ratio actually formed by the drive pulley 16 and the driven pulley 26 at that time. This is because the moving speeds of the movable conical plates 22 and 34 toward the high gear ratio side when the pulleys 16 and 26 are not rotating are substantially constant (corresponding to a constant k).
Since it has been confirmed by the experiment that the time elapsed after the sudden braking state is known, step 84
This is because the actual states of the drive pulley 16 and the driven pulley 26 can be known by the calculation shown in FIG. Step motor 1
The shift control valve 106 moves according to the movement of 10, and hydraulic pressure is supplied to the drive pulley cylinder chamber 20 so that the movable conical plate 22 of the drive pulley 16 is in a state corresponding to Ps. Therefore, when the throttle is opened in this state, the rotational force can be immediately transmitted. This is because a predetermined hydraulic pressure has already been supplied to the drive pulley cylinder chamber 20 and the V-belt 24 is in tension. Further, since the gear ratio at this time is in the state of the gear ratio that should be instructed according to the driving condition at that time, it is not possible that the gear is changed to the smaller gear ratio at the same time when the throttle is opened. Instead, the re-driving state can be achieved very smoothly. Note that such control is performed only in a low speed state where the wheels are locked (steps 802 and 80).
6). Further, the rotation of the step motor 110 in the upshift direction at the time of the above control is performed at a speed twice that in the case of the normal shift control (step 854 and step 90).
4 → 906 → 908).

(Embodiment of the Second Invention) FIG. 11 shows an embodiment of the second invention. The only difference between the embodiment of the first invention and the embodiment of the second invention described above is that step 851 and step 853 are provided between step 850 and step 854. The other structure is similar to that of the first embodiment of the invention. Determine whether the throttle is in the open in step 851, a value obtained by subtracting a predetermined value △ P from the value of Ps when the throttle is not in the open set to P _D (same 853),
Go to step 854. The traveling Ps when the throttle is opened is set to _{P D} (same 852) Step 854. By doing so, when the brake operation is released, the step motor 110 rotates to a position on the side of the gear ratio larger by ΔP than the position corresponding to the state of the pulley at that time. Then, when the throttle is opened, the throttle is rotated to a position corresponding to the state of the pulley at that time. After all, by releasing the brake, the step motor 110 is not immediately rotated to the position corresponding to the state of the pulley at that time as in the embodiment of the first invention, but once the gear ratio is slightly higher than the final target position. Stop at, and move to the final target position only after the throttle opens. This is because there is some time between the release of the brake and the opening of the throttle.While the wheels are rotating without locking during that time, the gear responsiveness is restored. Step motor 110 to move to
Also, the speed change response is improved by moving the speed change control valve 106 to a slightly higher speed ratio side, and the step motor 110 is rotated in advance to near the final target position to open the step motor when the throttle is opened. 11
The rotational position of 0 and the position of the movable conical plate 22 of the drive pulley 16 are made to correspond promptly.

In the embodiments of the first and second inventions described above, the relief valve 25 is provided in the oil passage 176 communicating with the drive pulley cylinder chamber 20.
Since 5 is provided, it is possible to prevent an excessive hydraulic pressure from acting on the drive pulley cylinder chamber 20 even when the above-described control for releasing the sudden brake is performed. That is, when the step motor 110 is rapidly moved to the smaller gear ratio side when the brake is released, the spool 174 of the gear control valve 106 is moved.
Rapidly moves to the smaller gear ratio side, and the line pressure directly acts on the drive pulley cylinder chamber 20. In this case, since the drive pulley 16 and the driven pulley 26 are not rotating, the feedback of the gear ratio via the link 178 is delayed, the throttling effect of the spool 174 of the gear change control valve 106 does not occur, and the line pressure remains unchanged. Will be supplied. However, since the relief valve 255 is provided,
The hydraulic pressure in the drive pulley cylinder chamber 20 does not become higher than a predetermined value. Therefore, as shown in FIG. 2, even if the drive pulley cylinder chamber 20 has a large pressure receiving area in the two chambers 20a and 20b, excessive tension is prevented from acting on the V-belt 24, damage to the V-belt, and pulley damage. It is possible to prevent the occurrence of problems such as breakage. It should be noted that the set pressure of the relief valve 255 may be set to be slightly higher than the maximum pressure of the drive pulley cylinder chamber 20 required for normal gear shifting in which the pulley is rotating. In each of the above-described embodiments, the feedback of the pulley position to the speed change control valve 106 is performed via the link 178, but the speed change control valve is driven only by the electric actuator. Sho 5
The present invention can be applied even if it is the same as that disclosed in 8-170958 or the like.

(G) Effect of the Invention As described above, according to the present invention, when the brake is released after the sudden braking or the throttle is opened, the shift motor is driven so as to correspond to the gear ratio formed by the pulleys. , The power can be immediately transmitted without causing the V-belt to slip, the durability of the V-belt and the pulley can be improved, and the discomfort due to the shift during re-driving does not occur.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the constituent elements of the first invention, and FIG.
The figure shows the power transmission mechanism of the continuously variable transmission, FIG. 3 shows the hydraulic control device of the continuously variable transmission, and FIG. 4 shows the gear change control device of the continuously variable transmission. , 7 and 8 are diagrams showing a control routine of the shift control device, FIG. 9 is a diagram showing a lock-up on vehicle speed and a lock-up off vehicle speed, and FIG. 10 is a diagram showing a relationship between a gear ratio and a step motor position, First
FIG. 1 is a diagram showing an embodiment of the second invention, and FIG. 12 is a diagram showing a relationship between constituent elements of the second invention. 16 ... Drive pulley, 24 ... V belt, 26 ... Followed pulley, 106 ... Gear change control valve, 110 ... Gear change actuator (step motor), 158 ... Gear ratio detection member, 178 ... Link, 182 ... …rod.

Claims (6)

[Claims] 1. A drive pulley and a driven pulley, each of which comprises a fixed cone plate and a movable cone plate, a V-belt wound around both pulleys, a gear shift actuator, and a movable cone of both pulleys according to movement of the gear shift actuator. In a control device for a continuously variable transmission having a shift control valve capable of controlling hydraulic pressure acting on a plate, a sudden brake detecting unit capable of detecting a sudden braking state, and a brake release detecting unit detecting a brake release. ,
Brake release time pulley state detection means for calculating or detecting the position of the movable conical plate of the drive pulley or driven pulley when the brake is released after the sudden brake state is detected, and the brake release at the same time when the brake is released. A control device for a continuously variable transmission, comprising: after-brake-release gearshift actuator driving means for driving the gearshift actuator at a gear ratio position corresponding to a pulley state detected by the time-blur state detection means. 2. A brake release time pulley state detecting means is based on a gear ratio position of a gear shift actuator when a sudden braking state is detected, and an elapsed time from this time until the brake operation is released. The control device for a continuously variable transmission according to claim 1, which calculates a pulley state when the brake is released. 3. The continuously variable transmission according to claim 1, wherein the shift actuator driving means after releasing the brake drives the shift actuator at a speed higher than a driving speed of the shift actuator during a normal shift. Control device. 4. A relief valve for preventing hydraulic pressure from rising above a predetermined level is provided in an oil passage for supplying hydraulic pressure from the shift control valve to the drive pulley.
A control device for a continuously variable transmission according to the item. 5. A drive pulley and a driven pulley, each of which is a fixed cone plate and a movable cone plate, a V belt wound between the pulleys, a speed change actuator, and a movable cone plate of both pulleys according to movement of the speed change actuator. A control device for a continuously variable transmission having a shift control valve capable of controlling a hydraulic pressure that acts on a sudden braking state detecting means for detecting a sudden braking state, and a throttle opening detecting means for detecting a throttle opening state of an engine. , When the throttle is opened after the sudden braking state is detected, the pulley state detection means for calculating or detecting the position of the movable conical plate of the driving pulley or the driven pulley, and the throttle opening state and the throttle opening state at the same time The shift actuator is set to the gear ratio position corresponding to the pulley state detected by the pulley state detecting means. A control device for a continuously variable transmission, comprising: 6. The throttle-opened shift actuator driving means has a gear ratio larger than the gear ratio position corresponding to the pulley state detected by the throttle open pulley state detecting means when the brake is released by a predetermined value. 6. The control device for a continuously variable transmission according to claim 5, wherein the speed change actuator is driven in advance to the position, and the speed change actuator is driven to the speed change ratio position at the same time when the throttle is opened.