JP2002266999A - Transmission control device for infinite gear ratio continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission control device for infinite gear ratio continuously variable transmission which is capable of performing recovery to GNP with a quick response to the wheel speed change at hard braking, without need for upsizing of the step motor. SOLUTION: This transmission control device includes a step motor 36 serving as a transmission actuator, a motor shaft structure with the following two shafts; an outside shaft 72 which converts a rotational amount given by a motor rotor 71 to a traveling amount in the axial direction and moves in the axial direction; and an inside shaft 74 which is located at the inside of the outside shaft 72 and of which one end is linked to a transmission link 37, an electromagnetic clutch 70 which is capable of engaging the outside shaft 72 and inside shaft 72 in one body, recovery springs 75 and 76 which forcefully moves the inside shaft 74 to GNP in the case where the integration of inside shaft 74 and outside shaft 72 disengages.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infinitely variable speed ratio transmission (hereinafter referred to as IVT: Infi.
nitely Variable Transmission).

[0002]

2. Description of the Related Art Conventionally, as a continuously variable transmission with an infinite transmission ratio, for example, a transmission described in Japanese Patent Application Laid-Open No. 10-325559 has been known.

[0003] As shown in FIG.
A toroidal type continuously variable transmission that continuously changes the gear ratio by tilting the power roller held between the input and output disks and a constant transmission are connected to the unit input shaft, respectively, and the toroidal type continuously variable transmission is also connected. And an infinite speed ratio continuously variable transmission in which the output shaft of a constant transmission is connected to a unit output member via a planetary gear mechanism, a power circulation mode clutch and a direct connection mode clutch.

In such a continuously variable transmission with an infinite transmission ratio,
By connecting the power circulation mode clutch and disengaging the direct connection mode clutch, the IVT according to the difference between the CVT speed ratio of the toroidal type continuously variable transmission (CVT = continuously variable transmission) and the speed ratio of the fixed transmission is determined. Gear ratio (Fig. 7 is 1 / IVT
Transmission ratio = IVT speed ratio characteristic is infinite from negative value to positive value (geared neutral point: GNP)
And a power-circulation mode in which gearshift control is continuously performed, and a power-circulation mode clutch is disconnected, and a direct-coupled mode clutch is connected to perform gearshift control in accordance with the CVT gear ratio of the toroidal-type continuously variable transmission. By selectively using the direct connection mode, it is possible to obtain an IVT transmission region in which the CVT transmission region is further expanded (see FIG. 7).

Here, the toroidal type continuously variable transmission has a hydraulic cylinder for displacing a power roller sandwiched by an input / output disk in a tilt axis direction via a trunnion, and a shift command for generating a control hydraulic pressure to the hydraulic cylinder. A transmission mechanism is provided which includes a valve, a step motor for driving and controlling the transmission command valve, and a transmission link for mutually connecting a precess cam for feeding back the displacement of the trunnion and the tilt angle of the power roller (FIGS. 2 and 3). 3).

[0006] By outputting a control command to a step motor of the transmission mechanism so as to attain a target gear ratio in accordance with the driving state of the vehicle, a control oil pressure to a hydraulic cylinder is generated by a shift control valve, and the trunnion is controlled. Is shifted in the tilt axis direction to tilt the power roller, and the tilt angle of the power roller is fed back to the shift control valve via the precess cam, and C is adjusted according to the control command.
Shift control for obtaining the VT gear ratio is performed.

[0007]

However, in a conventional shift control device for a continuously variable transmission with an infinite transmission ratio, a stepping motor having a response speed required for normal shift control is used. At the time of rapid braking in the circulation mode, the movement of the motor shaft of the step motor from the IVT gear ratio position on the forward side or the reverse side to the GNP is delayed due to a sudden change in the wheel speed. As shown in the torque flow at the time of D range coasting, the engine stall is caused by the braking torque from the drive wheels acting on the engine via the infinitely variable speed ratio transmission in which the power paths are mechanically coupled. There is a problem of inviting.

Therefore, if a step motor having a high response is used to follow such a change in the wheel speed, the above problem can be solved. However, since the response is unnecessary in the normal shift control, the step motor is unnecessary. There is a problem that the size is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. An object of the present invention is to provide a GNP capable of responding quickly to changes in wheel speed during sudden braking without increasing the size of a step motor. SUMMARY OF THE INVENTION It is an object of the present invention to provide a shift control device for a continuously variable transmission with an infinitely variable gear ratio that can be returned to a constant speed.

[0010]

To achieve the above object, according to the first aspect of the present invention, a toroidal type in which a power ratio held between an input / output disk is tilted to continuously change a gear ratio is provided. The continuously variable transmission and the constant transmission are connected to the unit input shaft, respectively, and the output shaft of the toroidal type continuously variable transmission and the constant transmission is connected to the unit output via a planetary gear mechanism, a power circulation mode clutch and a direct connection mode clutch. A gearless infinitely variable transmission connected to the members,
A hydraulic cylinder that displaces the power roller of the toroidal-type continuously variable transmission in a tilt axis direction via a trunnion;
A shift command valve that creates control oil pressure to the hydraulic cylinder, a step motor that drives and controls the shift command valve, and a shift link that connects a precess cam that feeds back the displacement of the trunnion and the tilt angle of the power roller, A shift control unit for outputting a control command to the step motor so as to achieve a target gear ratio according to a driving state of the vehicle. An outer shaft that converts the amount of rotation given by the motor rotating unit into an axial movement amount and moves in the axial direction, and is coaxially arranged at an inner position of the outer shaft,
A motor shaft structure having two shafts, one end of which is connected to the speed change link, and an engagement / disengagement structure provided between the outer shaft and the inner shaft so that the inner shaft and the outer shaft can be integrally engaged. When,
And a GNP forced return structure for forcibly moving the inner shaft to the geared neutral point position when the integration of the inner shaft and the outer shaft is released.

According to a second aspect of the present invention, in the shift control device for an infinitely variable speed ratio transmission according to the first aspect,
The step motor engagement / disengagement structure is a means using a clutch that performs engagement release according to an instruction from the outside. In the normal shift control, the clutch integrates an inner shaft and an outer shaft by clutch engagement to form a power path. Is provided with a clutch release control means for releasing the integration of the inner shaft and the outer shaft by releasing the clutch when the deceleration of the drive wheel is large via the infinitely variable speed ratio transmission in which the gears are mechanically coupled. It is characterized by the following.

According to a third aspect of the present invention, in the shift control device for an infinitely variable speed ratio transmission according to the first aspect,
The stepping motor engaging and disengaging structure has an inner shaft formed with an axial groove and a circumferential groove communicating with each other, and an outer shaft formed with a pin engaging with the axial groove and the circumferential groove at an inner circumferential position thereof. A linear-rotation conversion mechanism for converting an axial force received from the power roller into a rotational force of the inner shaft is provided at a transmission link connecting portion at an inner shaft end, and when the axial force is less than a set value, a circumferential direction By maintaining the pin engagement with the groove, the inner shaft and the outer shaft are integrated, and when the axial force is equal to or greater than the set value, the transition from the circumferential groove to the pin engagement with the axial groove allows the inner shaft to be engaged. And means for releasing the integration between the shaft and the outer shaft.

According to a fourth aspect of the present invention, in the shift control apparatus for an infinitely variable speed ratio transmission according to any one of the first to third aspects, the GNP forced return structure of the step motor has one end thereof. It is characterized in that it has an elastic body that applies an urging force to the inner shaft connected to the speed change link so as to move to the geared neutral point.

According to a fifth aspect of the present invention, in the shift control device for an infinitely variable speed ratio transmission according to the fourth aspect,
The GNP forced return structure of the step motor restricts the movement of the inner shaft past the geared neutral point position by the biasing force of the elastic body at the time of the forced return, and the position control that maintains the inner shaft at the geared neutral point. It is a structure having members.

[0015]

According to the first aspect of the present invention, at the time of shifting, the shift control means outputs a control command to the step motor so as to attain a target speed ratio according to the driving state of the vehicle. . At the time of this shift control, when the inner shaft and the outer shaft constituting the motor shaft of the step motor are integrally engaged by an engagement / disengagement structure, the amount of rotation given by the motor rotating portion is applied in the axial direction. The outer shaft, which is converted into the amount of movement and moves in the axial direction, and the inner shaft, one end of which is connected to the speed change link, operate integrally. That is, the motor operates in the same manner as the conventional one-axis motor shaft.

On the other hand, when the integration of the inner shaft and the outer shaft constituting the motor shaft of the step motor is released by the engagement / disengagement structure during the speed change control, one end is connected to the speed change link by the GNP forced return structure. The forced inner shaft is moved to the geared neutral point.

That is, when a step motor needs to promptly return to the GNP while using a step motor having a normal shift control response. For example, when the drive wheel is locked, the inner shaft and the outer shaft are disengaged by the engagement / disengagement structure. By simply canceling the integration with the shaft, the GNP return can be achieved by the high response speed of the inner shaft connected to the speed change link.

Therefore, the motor can be returned to the GNP with good response by sufficiently following the wheel speed change at the time of sudden braking without increasing the size of the step motor.

According to the second aspect of the present invention, the engaging / disengaging structure of the stepping motor is a clutch that performs engagement / disengagement in response to an external command. When the deceleration of the drive wheels is large through the infinitely variable speed ratio transmission in which the inner shaft and the outer shaft are integrated by the clutch engagement and the power path is mechanically coupled, the inner shaft and the outer shaft are released by the clutch release. The integration with the shaft is released.

Therefore, whether or not it is necessary to immediately return to GNP is monitored by a sensor signal or the like, and when it is determined that it is necessary to immediately return to GNP, a clutch release command is output from the outside to quickly It is possible to return to GNP with good response following the change in wheel speed during braking.

According to the third aspect of the present invention, the stepping motor engaging and disengaging structure is such that an axial groove and a circumferential groove communicating with each other are formed on the inner shaft, and the shaft is formed on the inner shaft at the outer shaft. A pin that engages with the directional groove and the circumferential groove is provided, and a direct-rotation conversion mechanism that converts an axial force received from the power roller into a rotational force of the inner shaft is provided at a transmission link connecting portion at an inner shaft end. Structure. When the axial force is less than the set value, for example, during normal shift control, the inner shaft and the outer shaft are integrated by maintaining the pin engagement with the circumferential groove, and it is necessary to immediately return to the GNP. In some situations, when the axial force is greater than or equal to the set value, the transition from the circumferential groove to the pin engagement with the axial groove releases the integration of the inner shaft and the outer shaft.

Therefore, a simple and maintenance-free engagement / disengagement structure utilizing the torque acting on the power roller without using a control means such as a clutch allows the GNP to respond satisfactorily by following the wheel speed change during sudden braking. Can be restored.

According to the fourth aspect of the present invention, the GNP forcible return of the step motor is performed such that one end of the step motor moves to a geared neutral point with respect to an inner shaft connected to the speed change link. This is done by an elastic body that gives power.

Therefore, the GNP forced return of the inner shaft with high response can be achieved with a simple structure using the urging force of the elastic body.

According to the fifth aspect of the present invention, when the step motor is forcibly returned to the GNP, the position of the inner shaft is restricted from moving by the biasing force of the elastic body past the position of the geared neutral point. The inner shaft position is maintained at the geared neutral point.

Therefore, when the GNP is forcibly returned due to a high response, the inner shaft is prevented from swinging before and after the GNP, and the inner shaft can be reliably stopped at the GNP.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment for realizing a shift control device for a continuously variable transmission with an infinite speed ratio according to the present invention will be described.
A first embodiment corresponding to claims 1, 2 and 4;
A second embodiment corresponding to the second and fourth embodiments;
And a fourth embodiment corresponding to claims 1 and 3.
A description will be given based on an embodiment and a fifth embodiment corresponding to claims 1 and 3.

(First Embodiment) First, the configuration will be described.

FIG. 1 is an overall configuration diagram showing an infinitely variable speed ratio continuously variable transmission according to a first embodiment.
Between a VT input shaft 1 (unit input shaft) and an IVT output shaft 2 (unit output member) connected to driving wheels, a double-cavity toroidal-type continuously variable transmission mechanism 4 composed of a half toroidal, and a constant A transmission 5 and a single planetary planetary gear mechanism 6 are arranged. Note that a differential 3 is interposed between the IVT output shaft 2 and the drive wheels.

The toroidal-type continuously variable transmission 4 has two sets of input disks 41 and 41 connected to the input shaft 1 and two sets of output disks 4 connected to the output belt mechanism 42.
3, 43 and two power rollers 44, 44 sandwiched between the input / output disks 41, 43. The power rollers 44, 44 are respectively supported by trunnions 45, 45 (see FIG. 2), and the power rollers 44, 44 are tilted to the power rollers 44, 44 by slightly displacing the trunnions 45, 45 in the tilt axis direction. By applying a force and tilting until the tilt angle becomes a tilt angle according to the control command, the CVT speed ratio determined by the tilt angle of the power rollers 44, 44 is changed steplessly.

The constant transmission 5 is provided with an input gear 51 fixed to the IVT input shaft 1 and meshes with the input gear 51.
The output gear 52 is rotatably supported on the output shaft 2 and includes a reduction gear mechanism.

The planetary gear mechanism 6 includes a sun gear 61 rotatably supported on the IVT output shaft 2, a pinion carrier 62 supporting a pinion, and a ring gear 63 fixed to the IVT output shaft 2. I have.

The pinion carrier 6 of the planetary gear mechanism 6
A power circulation mode clutch 8 is disposed between the output gear 52 of the fixed transmission 5 and the output belt mechanism 42 of the toroidal type continuously variable transmission mechanism 4 and the IVT output shaft 2. Are located. The engagement force of the direct connection mode clutch 9 is determined by the hydraulic pressure supplied to the first hydraulic servo 91 from the first solenoid valve 92, and the engagement force of the power circulation mode clutch 8 is determined by the second hydraulic servo 93.
Is determined by the oil pressure supplied from the second solenoid valve 94.

A CVT input rotation sensor 10 is disposed at a position close to the teeth of the input gear 51 of the constant transmission 5, and a CVT input rotation sensor is disposed at a position close to the output belt mechanism 42 of the toroidal type continuously variable transmission 4. An output rotation sensor 11 is disposed, and a sensor gear 1 provided on the IVT output shaft 2
An output rotation sensor 12 (vehicle speed sensor) is disposed at a position close to the third tooth portion.

FIGS. 2 and 3 show a C for controlling the shift of the IVT.
FIG. 3 is a diagram illustrating a VT transmission mechanism. The power roller 44 is supported by a trunnion 45 from the back. The speed change by the toroidal-type continuously variable transmission mechanism 4 is performed by displacing the trunnion 45 up and down from the equilibrium point. The roller 44 tilts.

The trunnion 45 is connected to the servo piston 31 of the hydraulic servo 30,
In the Hi-side cylinder 30a and the Low-side cylinder 30
It is displaced by the differential pressure of the oil in b. The hydraulic pressure of the Hi-side cylinder 30a and the hydraulic pressure of the Low-side cylinder 30b are controlled by a shift command valve 46.

When the spool 46S in the valve is displaced, the shift command valve 46 is moved to the line pressure port 46L.
Is supplied to one of the Hi-side port 46Hi and the Low-side port 46Lo, and the other Low-side port 46Lo.
Alternatively, the differential pressure in the hydraulic servo 30 is changed by causing oil to flow from the Hi-side port 46Hi to the drain port 46L.

A precess cam 35 is attached to one of the trunnions 45.
5 is grooved. The groove of the precess cam 35 is in contact with one end of the L-shaped link 38, and one end of the L-shaped link 38 is freely supported by one end of the speed change link 37. Therefore, the displacement and the tilt angle of the trunnion 45 are fed back to the speed change link 37. The other end of the transmission link 37 is connected to a step motor 36, and the transmission command valve 4
The sixth spool 46S is freely supported on the speed change link 37. Therefore, the displacement of the spool 46S is determined from the displacement of the step motor 36 and the feedback from the precess cam 35.

FIG. 4 is a view showing an IVT electronic control system. The IVT controller 20 outputs a control command based on input information, and the trunnion 4 supporting the power roller 44.
5, a stepping motor 36 as a speed change control actuator, a low clutch solenoid 21 as a control actuator for engaging and disengaging the power circulation mode clutch 8, and a high as a control actuator for engaging and releasing the direct connection mode clutch 9. Clutch solenoid 22
And an electromagnetic clutch solenoid 26 for engaging and releasing an electromagnetic clutch 70 described later.

The IVT controller 20 receives a range signal from an inhibitor switch (not shown) and the CVT
A CVT input rotation signal from the input rotation sensor 10, a CVT output rotation signal from the CVT output rotation sensor 11, and an output shaft rotation (vehicle speed) from the output rotation sensor 12.
Signal, a throttle opening signal from a throttle opening sensor (not shown), and idle S from an idle switch (not shown).
W signal and brake SW from brake switch (not shown)
A signal, an oil temperature sensor signal from the oil temperature sensor 24, other signals, and information such as a target idle speed, an idle control flag, an acceleration stall determination signal, and the like from the engine controller 25 are input.

The IVT controller 20 includes a mode switching control section for controlling switching between a power circulation mode and a direct connection mode, a CVT speed ratio control section for controlling a speed ratio of the toroidal type continuously variable transmission mechanism 4, and a step motor. An electromagnetic clutch release / engagement control unit that outputs a control command to release / engage the 36 electromagnetic clutches 70 is provided.

In the mode switching control section, the GN having an infinite IVT gear ratio is established by engaging the power circulation mode clutch 8.
A power-circulating mode for transmitting power including P, and a toroidal-type continuously variable transmission mechanism 4
And a CVT direct connection mode (= power direct connection mode) for transmitting power in accordance with the output of the clutch is controlled at a rotation synchronization point (RSP; also referred to as a mode switching point) at which the IVT speed ratio matches. The low clutch solenoid 21 of the second solenoid valve 94 is calculated based on the calculation processing result.
Then, a control command is output to the high clutch solenoid 22 of the first solenoid valve 92.

In the CVT speed ratio control section, the target IVT
A target IVT speed ratio is determined based on the input speed and the detected output speed (actual IVT output speed), and speed ratio control for controlling the speed ratio of the toroidal type continuously variable transmission mechanism 4 is performed so as to achieve the target IVT speed ratio. A control command is output to the step motor 36 based on the result of the arithmetic processing.

In the electromagnetic clutch release / engagement control section,
The engine speed, vehicle speed, brake operation, and the like are monitored, and when the drive wheels are likely to lock (for example, when the engine speed is low or when the engine stall determination is likely to be ON), the electromagnetic clutch solenoid 26 is actuated. A control command to release the electromagnetic clutch 70 of the step motor 36 is output, and if the time from the start of clutch release to the release of the brake is shorter than the set time, the clutch is engaged simultaneously with the release of the brake, and the brake is released from the start of the clutch release. If the time until is more than the set time, the step motor 36
After confirming that the electromagnetic clutch 70 has been moved to P, a control command for engaging the released electromagnetic clutch 70 is output.

FIGS. 5 and 6 are sectional views showing the stepping motor 36 of the first embodiment. The stepping motor 36 converts the amount of rotation given by the motor rotating unit 71 into the amount of movement in the axial direction, and Outer shaft 7 having moving screw portion 72a
2 and a motor shaft structure comprising two shafts coaxially arranged inside the outer shaft 72 and having one end (link connecting portion 73) connected to the speed change link 37. An electromagnetic clutch 70 (an engagement / disengagement structure) capable of integrally engaging the inner shaft 74 and the outer shaft 72 by applying an electromagnetic clutch powder to the inner surface and the outer surface of the inner shaft 74 and energizing;
The release of the electromagnetic clutch 70 allows the inner shaft 74 and the outer shaft 72
The two return springs 75, 76 (elastic bodies) forcibly moving only the inner shaft 74 to the geared neutral point (hereinafter referred to as GNP) at the same time as the unification of the inner shaft 74 is released. Is provided.

The return springs 75 and 76 are a pair of cone coil springs. One end on the spring top side is connected to the other end of the inner shaft 74, and the other end on the spring bottom side is the motor case 77.
When the electromagnetic clutch is disengaged and the inner shaft 74 is not restrained by the outer shaft 72, as shown in FIG. 6, the biasing force balanced positions of the two return springs 75 and 76 become GNP (GNP forced return structure).

Next, the operation will be described.

[IVT Gear Ratio Control Action] The IV shown in FIG.
The IVT speed ratio control operation will be described based on T speed ratio characteristics (the vertical axis is 1 / IVT speed ratio = output shaft speed / input shaft speed, and the horizontal axis is CVT speed ratio).

In the mode switching control section of the IVT controller 20, in the power circulation mode in which the power circulation mode clutch 8 is engaged and the direct connection mode clutch 9 is released, the pinion carrier 62 of the planetary gear mechanism 6 is connected to the power circulation mode clutch 8 By the engagement, the IVT input rotation speed rotates at a constant rotation speed reduced by the constant transmission 5, the sun gear 61 changes its rotation speed in accordance with the change in the CVT transmission ratio, and the rotation of the ring gear 63 changes infinitely. The output shaft rotation of the machine.

Therefore, the CVT of the IVT controller 20
In the speed ratio control unit, the CVT speed ratio is changed from high to low by a command to the step motor
By controlling the VT gear ratio, the 1 / IVT gear ratio changes as shown in the power circulation mode characteristic of FIG.
The rotation of the output shaft of T is reverse → neutral → forward.

In the CVT direct connection mode in which the power circulation mode clutch 8 is released and the direct connection mode clutch 9 is engaged in the mode switching control section of the IVT controller 20, the pinion carrier 62 of the planetary gear mechanism 6 is connected to the power circulation mode clutch. 8, the ring gear 63 can be freely rotated, and the ring gear 63 is connected to the sun gear 61 by the engagement of the direct connection mode clutch 9 and rotates at the same rotation speed.

Therefore, the CVT of the IVT controller 20
In the gear ratio control unit, a command to the step motor 36 is set so that the CVT gear ratio changes from low to high.
By controlling the VT speed ratio, the 1 / IVT speed ratio changes as shown in the CVT direct connection mode characteristic of FIG.
The VT gear ratio changes from low to high in the forward direction.

[Electromagnetic clutch release control processing] FIG.
Each step will be described below with a flowchart illustrating a flow of an electromagnetic clutch release control process executed by the electromagnetic clutch release / engagement control unit of the T controller 20.

In step 100, the input speed (eg, engine speed), output speed (eg, vehicle speed), brake O
N / OFF (eg, a brake SW signal) and an acceleration stall determination signal (from the engine control controller 25) are read.

In step 101, it is determined whether or not the detected value of the acceleration due to the time change of the vehicle speed or the longitudinal acceleration is equal to or less than the set deceleration G, that is, whether or not the vehicle is rapidly decelerating. The process proceeds to NO in the case of NO.

At step 102, it is determined from the brake switch signal whether or not the brake is ON (at the time of brake operation). If YES, the process proceeds to step 104, where NO
If, go to END.

In step 103, it is determined whether or not the detected vehicle speed exceeds the set vehicle speed V.
If ES, proceed to END; if NO, step 1
Go to 04.

In step 104, if the brake operation is performed while the vehicle is in a rapid deceleration state, or if the vehicle is not in a rapid deceleration state but has a vehicle speed close to a stop, it is determined that the engine speed has decreased. Proceed to step 105. This determination is based on the fact that the engine speed Neng is equal to the set speed N
Less than (Neng <N) or engine speed change △
Neng is negative and the engine speed change amount △ Neng exceeds the set change amount △ N (△ Neng <0, and, △
Neng> △ N).

In step 105, the engine speed is reduced (Neng <N) in step 104, or the engine stall determination is likely to be ON ({Neng <0, and, {Neng>}).
It is determined whether at least one condition of N) is satisfied. If YES, the process proceeds to a step 106, and if NO, the process proceeds to an END.

In step 106, a command to release the electromagnetic clutch 70 is output.

In step 107, only the inner shaft 74 moves to GNP due to the release of the electromagnetic clutch 70, so that a stroke difference occurs between the outer shaft 72 and the inner shaft 74 of the step motor 36, and the stroke difference increases. In order to prevent the step-out determination, a control start signal for shifting control for moving the outer shaft 72 in the direction toward GNP by the motor rotating unit 71 is output.

[Electromagnetic clutch engagement control process] FIG.
Each step will be described below with a flowchart showing the flow of the electromagnetic clutch engagement control process executed by the electromagnetic clutch release / engagement control unit of the T controller 20.

In step 108, the input speed (eg, engine speed), output speed (eg, vehicle speed), brake O
N / OFF (eg, a brake SW signal), acceleration, and accelerator pedal ON / OFF (eg, an idle SW signal) are read.

In step 109, the time T from the release of the electromagnetic clutch 70 to the release of the brake is calculated.

In step 110, the time T from the start of release of the electromagnetic clutch 70 to the release of the brake is equal to the set time T
It is determined whether it is less than 1. If YES, the process proceeds to a step 111, and if NO, the process proceeds to a step 114.

In step 111, when T <T1 in the determination of step 110, a command to engage the electromagnetic clutch 70 is output.

In step 112, the routine proceeds to electromagnetic clutch release control (FIG. 8).

At step 113, corresponding to step 107 of the electromagnetic clutch release control, a control end signal to the shift control is output.

In step 114, when T ≧ T1 in the determination in step 110, the step motor 36 moves the CVT speed ratio in each IVT mode in the GNP direction.

In step 115, the step motor 36
Is determined to be GNP, and if YES,
The process proceeds to steps 111 to 113, and if NO, the process proceeds to step 116.

In step 116, the driver's intention to accelerate is determined based on whether the detected acceleration value (time change in vehicle speed or longitudinal acceleration) exceeds the set value G1 or whether the accelerator pedal is turned on. , To step 117, and to NO in the case of NO.

In step 117, the electromagnetic clutch 70 is temporarily engaged.

[Shift operation by step motor] IVT
The CVT gear ratio control unit of the controller 20 determines the target IVT gear ratio based on the target IVT input rotation speed and the actual IVT output rotation speed according to the operating state of the vehicle (vehicle speed and throttle opening), and toroidally sets the target IVT gear ratio. A speed ratio control for controlling the speed ratio of the die-type continuously variable transmission mechanism 4 is performed, and a control command is output to the step motor 36 based on the result of the arithmetic processing.

In the normal speed change of this speed change control, FIG.
As shown in FIG. 7, the inner shaft 74 and the outer shaft 72 constituting the motor shaft of the step motor 36 are integrally engaged by the electromagnetic clutch 70, and the amount of rotation given by the motor rotating unit 71 is converted into the amount of axial movement. The outer shaft 72, which converts and moves in the axial direction, and the inner shaft 74, one end of which is connected to the speed change link 37, operate integrally. That is, the motor operates in the same manner as the conventional one-axis motor shaft.

On the other hand, at the time of sudden braking or sudden deceleration, when the engine stall is likely to occur due to the locking of the drive wheels, in the flowchart of FIG.
Step 101 → Step 102 (or Step 10)
3) → Step 104 → Step 105 → Step 10
6 → Step 107
6, the electromagnetic clutch 70 is released, and the inner shaft 7 constituting the motor shaft of the step motor 36 by releasing the clutch.
4 and the outer shaft 72 are released, and at the same time as the release of the integration, the urging forces of the two return springs 75 and 76 for moving to the GNP act on the inner shaft 74, and only the inner shaft 74 is forcibly forced to GNP. The inner shaft 7 is moved as shown in FIG.
4 is a GNP which is a position where the two return springs 75 and 76 are balanced.
Is maintained.

That is, as the step motor 36,
When an engine stall is likely to occur due to locking of the drive wheels while using a gear that can provide normal shift control responsiveness, release of the electromagnetic clutch 70 merely releases the integration of the inner shaft 74 and the outer shaft 72, GNP return is achieved by the high response speed of the inner shaft 74 connected to the speed change link 37.

When the time T from the start of the release of the electromagnetic clutch 70 to the release of the brake is shorter than the set time T1, step 108 in the flowchart of FIG.
→ Step 109 → Step 110 → Step 111 →
The flow proceeds from step 112 to step 113,
In step 111, the electromagnetic clutch 70 is engaged simultaneously with the release of the brake. In other words, when the brake is depressed for a moment, the inner shaft 74 and the outer shaft 72 are integrated again at the same time as the brake is released, and the shift control state by the step motor 36 is entered.

When the time T from the start of disengagement of the electromagnetic clutch 70 to the brake OFF is equal to or longer than the set time T1 and the outer shaft position has reached GNP by driving the step motor 36, in step 108 in the flowchart of FIG. Step 109 → step 110 → step 114 → step 115 → step 111 → step 112 → step 113. In step 111, the electromagnetic clutch 70 is engaged simultaneously with the determination of GNP. At the same time that the driver's intention to accelerate is determined, the electromagnetic clutch 70 is engaged. In other words, even if the brake is released, the inner shaft 74 and the outer shaft 7
Since the axial displacement with respect to the shaft 2 has occurred, after correcting the positional displacement, the inner shaft 74 and the outer shaft 72 are integrated, and the shift control state by the step motor 36 is started.

Further, when the time T from the start of release of the electromagnetic clutch 70 to the release of the brake is equal to or longer than the set time T1, even if the step motor 36 is driven, the outer shaft position is GNP.
If the accelerator pedal is depressed in that state, the step 108 → step 109 → step 110 → step 114 → step 115 → step 116 → step 1 in the flowchart of FIG.
At step 117, the electromagnetic clutch 70 is engaged at the same time as the determination of the driver's intention to accelerate at step 116. In other words, the inner shaft 74 and the outer shaft 72 are integrated while giving priority to the driver's intention to accelerate and allow some displacement in the axial direction, and the shift control state by the step motor 36 is entered.

[Electromagnetic clutch release / engagement control operation] The release / engagement control operation of the electromagnetic clutch 70 when sudden braking is performed during traveling will be specifically described with reference to a time chart shown in FIG.

First, when the brake is suddenly depressed at time t1, the input speed (engine speed) is reduced, and the output speed (vehicle speed) is also reduced. At time t2 when all of the conditions of step 101), the brake operation condition (step 102), and the engine speed reduction condition (step 105) are satisfied, the electromagnetic clutch 70 is released. Due to the release of the electromagnetic clutch 70, only the inner shaft 74 is forcibly forced to G as described above.
By being moved to NP, the 1 / IVT speed ratio sharply decreases from the time t2, and at the time t3 when the 1 / IVT speed ratio becomes 0, the power circulation mode clutch 8 is released, and the drive wheels and the engine And the power transmission path is cut off.

GNP by releasing the electromagnetic clutch 70
After the time point t3, the engine speed gradually decreases and then rises to prevent engine stall due to the release of the power circulation mode clutch 8 accompanying the forced movement of the clutch.

At time t4 when the brake release operation is performed
At a time point t5 at which the outer shaft 72 is returned to GNP by the driving of the step motor 36, the electromagnetic clutch 70 and the power circulation mode clutch 8 are simultaneously engaged,
The control state of the IVT gear ratio in the normal power circulation mode is entered.

Next, the effects will be described.

(1) In the transmission control device for a continuously variable transmission with an infinite speed ratio, the step motor 36 is
An outer shaft 72 that converts the amount of rotation given by into an axial movement amount and moves in the axial direction, and an inner shaft 74 that is coaxially arranged at an inner position of the outer shaft 72 and has one end connected to the speed change link 37. An electromagnetic clutch 70 that can integrally engage the outer shaft 72 and the inner shaft 74 with each other;
When the integration of the inner shaft 74 and the outer shaft 72 is released,
At the same time as the release of this integration, only the inner shaft 74 is forcibly GN
Since the speed change actuator has the return springs 75 and 76 for moving to P, it is possible to follow the change in wheel speed at the time of sudden braking and to return to GNP with good response without increasing the size of the step motor 36.

(2) The engagement / disengagement structure of the step motor 36 is an electromagnetic clutch 70 that engages and disengages according to an external command. The electromagnetic clutch disengagement / engagement control unit of the IVT controller 20 engages the clutch during normal shift control. When the deceleration of the drive wheels is large through the infinitely variable speed ratio continuously variable transmission in which the power path is mechanically combined with the inner shaft 74 and the outer shaft 72, the inner shaft 74 and the outer shaft 72 are disengaged by disengaging the clutch. Since the control for canceling the integration with the 72 is performed, a change in the wheel speed at the time of sudden braking is monitored by a sensor signal or the like.
By outputting the clutch release command from the outside, it is possible to follow the wheel speed change at the time of sudden braking and to return to GNP with good response.

(3) The GNP forced return structure of the step motor 36 is constituted by return springs 75 and 76 which apply an urging force to the inner shaft 74 whose one end is connected to the speed change link 37 so as to move to the GNP. The return spring 7
With a simple structure using the urging force of 5,76, GNP forced return of the inner shaft with high response can be achieved.

(Second Embodiment) In the second embodiment, as shown in FIGS. 11 and 12, the GNP forced return structure of the step motor 36 is connected at one end on the spring top side to the other end of the inner shaft 74. A return spring 78 formed by a conical coil spring having the other end on the spring bottom side fixed to the motor case 77; a return spring 79 formed by a cylindrical coil spring having one free end and the other end fixed to the motor case 77; This is an example in which a stopper plate 80 is fixed at a free end position (GNP) 79. Since the other configuration is the same as that of the first embodiment, illustration and description are omitted.

Further, the operation and effect of the second embodiment are the same as those of the first embodiment, so that the description will be omitted.

(Third Embodiment) In a third embodiment, as shown in FIGS. 13 and 14, the GNP forced return structure of the step motor 36 is connected at one end on the spring top side to the other end of the inner shaft 74. The return end of the spring bottom is fixed to the motor case 77. The return spring 78 is formed by a conical coil spring. This is an example constituted by a forward position regulating actuator 81 (position regulating member) to be maintained and a backward position regulating actuator 82 (position regulating member). Here, the forward position regulating actuator 81 is a solenoid actuator that regulates the inner shaft 74 to GNP by projecting during forward traveling in the power circulation mode. The backward position regulating actuator 82 is a solenoid actuator that regulates the inner shaft 74 to GNP by projecting when the vehicle is moving backward in the power circulation mode and when the CVT speed ratio is higher than the GNP speed ratio in the CVT direct connection mode. It is. Since the other configuration is the same as that of the first embodiment, illustration and description are omitted.

Next, the operation will be described.

FIG. 15 is a flowchart showing the flow of the position regulating actuator control processing executed by the position regulating actuator control section of the IVT controller 20.
Each step will be described.

In step 200, the current selector lever position, the previous selector lever position, and the target CVT gear ratio are read.

At step 201, it is determined whether or not the current selector lever position is the same as the previous selector lever position. If YES, the process proceeds to step 202, where NO
In the case of, the process proceeds to step 206.

At step 202, it is determined whether or not the current selector lever position is at the D range position. If YES, the process proceeds to step 203, and if NO, the process proceeds to step 205.

In step 203, it is determined whether or not the target CVT speed ratio is less than the CVT speed ratio corresponding to GNP.
In the CVT direct connection mode, it is determined whether or not the gear ratio is higher than the GNP gear ratio. If YES, the process proceeds to step 204 and N
If O, go to END.

In step 204, the forward position restricting member is pulled in by a command to the forward position restricting actuator 81, and the backward position restricting member is protruded by a command to the backward position restricting actuator.

At step 205, the previous state of the forward position restricting member and the backward position restricting member is maintained.

At step 206, it is determined whether the current selector lever position is at the P range position or the N range position. If YES, the process proceeds to step 207, and NO
In the case of, the process proceeds to step 208.

In step 207, the forward position restricting member is pulled in by a command to the forward position restricting actuator 81, and the backward position restricting member is pulled in by a command to the backward position restricting actuator. That is, the position restriction function is not performed at the P range position or the N range position.

At step 208, it is determined whether or not the current selector lever position is at the R range position. If YES, the process proceeds to a step 209, and if NO, the process proceeds to a step 210.

In step 209, the forward position restricting member is pulled in by a command to the forward position restricting actuator 81, and the backward position restricting member is protruded by a command to the backward position restricting actuator.

In step 210, it is determined whether or not the target CVT speed ratio is less than the CVT speed ratio corresponding to GNP.
In the CVT direct connection mode, it is determined whether or not the gear ratio is higher than the GNP speed ratio.
In the case of O, the process proceeds to step 212.

In step 211, the forward position restricting member is pulled in by a command to the forward position restricting actuator 81, and the backward position restricting member is protruded by a command to the backward position restricting actuator.

In step 212, the forward position restricting member is protruded by a command to the forward position restricting actuator 81, and the backward position restricting member is retracted by a command to the backward position restricting actuator.

Therefore, for example, if the target CVT speed ratio is GN
When the electromagnetic clutch 70 is disengaged during forward movement of the D range on the lower side than the CVT speed ratio corresponding to P, the return spring 78
The inner shaft 74 is moved from the position in FIG.
And the rear end face of the inner shaft 74 abuts on the forward position restricting member of the forward position restricting actuator 81, whereby the movement of the inner shaft 74 is restricted. The other operations are the same as those of the first embodiment, and the description is omitted.

As described above, the shift control device for a continuously variable transmission with an infinitely variable gear ratio according to the third embodiment has the following advantages in addition to the effects (1) and (2) of the first embodiment. The effect is obtained.

(4) The GNP compulsory return structure of the step motor 36 restricts the movement of the inner shaft 74 past the GNP by the urging force of the return spring 78 at the time of forcible return.
4 is a structure having a position regulating member for maintaining GNP, so that when the GNP is forcibly returned due to a high response, the inner shaft 74 is prevented from swinging before and after the GNP, and moreover, the inner shaft 74 is reliably stopped at the GNP. Can be achieved.

(Fourth Embodiment) In the first to third embodiments, the electromagnetic clutch 70 is used as the engagement / disengagement structure of the step motor.
On the other hand, the fourth embodiment uses the axial force received by the inner shaft 74 from the link connecting portion 73 in accordance with the magnitude of the braking torque transmitted to the power roller 44 when the driving wheels are locked, This is an example of a structure in which the integration of the inner shaft 74 and the outer shaft 72 is released.

That is, in the engagement / disengagement structure of the stepping motor of the fourth embodiment, as shown in FIG. 19, an axial groove 83 communicating with each other and a circumferential groove 84 in a 90-degree range are formed on the inner shaft 74. As shown in FIG. 18, a pin 85 and a rolling element 86 are provided at the inner peripheral position of the outer shaft 72 at the inner peripheral position thereof to engage the axial groove 83 and the circumferential groove 84. As shown in FIG. The axial force received by the inner shaft 74, which is elastically supported at both ends of the link connecting portion 73 by the disc springs 87, 87 and the snap rings 88, 88, is converted into the rotational force of the inner shaft 74. A direct-rotation conversion mechanism 89 is provided by a turning groove having a large number of balls interposed therebetween, and a return spring 90 is interposed between the inner shaft 74 and the motor case 77 as shown in FIG. . Here, the return spring 90 simultaneously releases the integration of the inner shaft 74 and the outer shaft 72, forcibly returns the inner shaft 74 to GNP, and
It has a function to regulate the shaft position.

Therefore, when the axial force is less than the set value during normal shift control or the like, the axial force from the link connecting portion 73 is converted to the rotational force of the inner shaft 74 by the direct-rotation conversion mechanism 89. However, the rotation angle of the inner shaft 74 does not reach 90 degrees, and the pin 85 maintains the engagement with the circumferential groove 84. Therefore, the inner shaft 74 and the outer shaft 72 are
The CVT speed ratio control by the stepping motor 36 is performed as in the related art by the engagement of the step 5 with the circumferential groove 84.

On the other hand, in a situation where the deceleration of the drive wheels is large, the braking torque transmitted to the power roller 44 increases as shown in FIG.
When the axial force from the link connecting portion 73 is converted into the rotational force of the inner shaft 74, the inner shaft 74 rotates 90 degrees, and the pin 85 shifts from the circumferential groove 84 to the engagement with the axial groove 83. As a result, the integration of the inner shaft 74 and the outer shaft 72 is released, and the pin 85 is forced into the axial groove 8 by the biasing force of the return spring 90.
Move along 3 to GNP.

As described above, in the shift control device for a continuously variable transmission with an infinitely variable gear ratio according to the fourth embodiment, the following effect is obtained in addition to the effect (1) of the first embodiment. .

(5) An axial groove 83 and a circumferential groove 84 communicating with each other are formed on the inner shaft 74, and the outer shaft 72 is engaged with the axial groove 83 and the circumferential groove 84 at the inner circumferential position. Pin 8
5 is provided, and the inner shaft 7
Since the direct-rotation conversion mechanism 89 for converting the axial force received by the motor 4 into the rotation force of the inner shaft 74 is provided, it is simple and simple using the torque acting on the power roller 44 without using a control means such as a clutch. The maintenance-free engagement / disengagement structure allows the vehicle to return to the GNP with a good response following the wheel speed change at the time of sudden braking.

(Fifth Embodiment) The fifth embodiment is basically the same as the fourth embodiment, except that the width of the axial groove is increased as it approaches the circumferential groove 84. 'Is an example. Note that other configurations and operations are described in the fourth section.
The description is omitted because it is similar to the embodiment.

Therefore, in the transmission control apparatus for a continuously variable transmission with an infinitely variable gear ratio according to the fifth embodiment, the power roller 44
When the axial torque from the link connecting portion 73 is converted into the rotational force of the inner shaft 74 in the direct-rotation conversion mechanism 89, the pin 85 is moved from the circumferential groove 84 in the axial direction. The transition to engagement with the groove 83 'becomes smooth, and it is possible to reliably return to GNP with a good response by following the wheel speed change during sudden braking.

(Other Embodiments) The shift control apparatus for an infinitely variable speed ratio transmission according to the present invention has been described based on the first embodiment and the second embodiment.
The present invention is not limited to these embodiments, and changes and additions of the design are allowed without departing from the gist of the present invention described in each claim of the claims.

For example, in the first to third embodiments, the example in which the electromagnetic clutch is used as the engagement / disengagement structure of the step motor has been described. However, an example in which a clutch using another driving method such as a hydraulic clutch is used. good.

In the fourth and fifth embodiments, the axial grooves 83
Although the structure for engaging and disengaging the step motor by the peripheral groove 84, the pin 85, and the direct-rotation conversion mechanism 89 has been described, the structure for engaging and disengaging the step motor by another structure may be used.

[Brief description of the drawings]

FIG. 1 is an overall system diagram showing an infinitely variable speed ratio transmission to which a transmission control device according to a first embodiment is applied.

FIG. 2 is a diagram illustrating a transmission mechanism of the toroidal-type continuously variable transmission according to the first embodiment.

FIG. 3 is a diagram illustrating a transmission mechanism of the toroidal-type continuously variable transmission according to the first embodiment.

FIG. 4 shows the IVT of the continuously variable transmission with infinite gear ratio according to the first embodiment.
FIG. 3 is a block diagram showing a speed ratio control system.

FIG. 5 is a cross-sectional view showing a step motor during a normal shift operation of the first embodiment.

FIG. 6 is a cross-sectional view illustrating the step motor during GNP movement according to the first embodiment.

FIG. 7 shows an IVT of the continuously variable transmission with an infinite gear ratio according to the first embodiment.
It is a figure showing a speed ratio characteristic.

FIG. 8 is a flowchart illustrating an electromagnetic clutch release control process performed by an electromagnetic clutch release / engagement control unit of the IVT controller according to the first embodiment.

FIG. 9 is a flowchart illustrating an electromagnetic clutch engagement control process performed by an electromagnetic clutch release / engagement control unit of the IVT controller according to the first embodiment.

FIG. 10 is a time chart showing a release / engagement control operation of the electromagnetic clutch during a brake operation in the first embodiment.

FIG. 11 is a cross-sectional view illustrating a step motor during a normal shift operation according to a second embodiment.

FIG. 12 is a cross-sectional view illustrating a step motor during GNP movement according to a second embodiment.

FIG. 13 is a cross-sectional view illustrating a step motor during a normal shift operation according to a third embodiment.

FIG. 14 is a cross-sectional view illustrating a step motor during GNP movement according to a third embodiment.

FIG. 15 is a flowchart illustrating a position regulation actuator control process performed by a position regulation actuator control unit of the IVT controller according to the third embodiment.

FIG. 16 is an overall sectional view showing a step motor of a fourth embodiment.

FIG. 17 is a partial cross-sectional view illustrating a link connecting portion of a step motor according to a fourth embodiment.

FIG. 18 is a partial cross-sectional view showing a joint between an inner shaft and an outer shaft of a step motor according to a fourth embodiment.

FIG. 19 is a partial sectional view showing an inner shaft of a step motor according to a fourth embodiment.

FIG. 20 is a partial cross-sectional view showing an inner shaft of the step motor of the fifth embodiment.

FIG. 21 is a diagram showing a torque flow during D range coasting in a conventional infinitely variable speed ratio transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IVT input shaft 2 IVT output shaft (unit output member) 3 Differential 4 Toroidal-type continuously variable transmission mechanism 5 Constant transmission 6 Planetary gear mechanism 8 Power circulation mode clutch 9 Direct connection mode clutch 10 CVT input rotation sensor 11 CVT output rotation sensor 12 Output rotation (vehicle speed) sensor 13 Sensor gear 20 IVT controller 21 Low clutch solenoid 22 High clutch solenoid 24 Oil temperature sensor 25 Engine control controller 30 Hydraulic servo 30a Hi side cylinder 30b Low side cylinder 31 Servo piston 35 Precess cam 36 Step motor 37 Speed change link 38 L-shaped link 41 input disk 42 output belt mechanism 43 output disk 44 power roller 45 trunnion 46 shift command valve 46S spool 46Hi Hi side Port 46Lo Low side port 46L Line pressure port 46D Drain port 51 Input gear 52 Output gear 61 Sun gear 62 Pinion carrier 63 Ring gear 70 Electromagnetic clutch (clutch) 71 Motor rotating part 72 Outer shaft 74 Inner shaft 75, 76 Return spring (elastic body) ) 77 Motor case 91 1st hydraulic servo 92 1st solenoid valve 93 2nd hydraulic servo 94 2nd solenoid valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 63:06 F16H 63:06

Claims (5)

[Claims] 1. A toroidal type continuously variable transmission for continuously changing a gear ratio by tilting a power roller held between an input / output disk and a constant transmission are connected to a unit input shaft, respectively. An infinitely variable speed ratio transmission in which the output shafts of a continuously variable transmission and a constant transmission are connected to a unit output member via a planetary gear mechanism, a power circulation mode clutch and a direct coupling mode clutch, and the toroidal continuously variable transmission A hydraulic cylinder for displacing the power roller of the machine in the tilt axis direction via a trunnion; a shift command valve for generating a control oil pressure to the hydraulic cylinder; a step motor for driving and controlling the shift command valve; A transmission link that connects the displacement and the precess cam that feeds back the tilt angle of the power roller to each other, and a target transmission according to the driving state of the vehicle And a shift control means for outputting a control command to the step motor so as to obtain a ratio of the step motor, wherein the step motor has a rotation provided by a motor rotating unit. Motor shaft structure comprising two shafts: an outer shaft that converts the amount into an axial movement amount and moves in the axial direction, and an inner shaft that is coaxially arranged at an inner position of the outer shaft and has one end connected to the speed change link. And an engagement / disengagement structure provided between the outer shaft and the inner shaft and capable of integrally engaging the inner shaft and the outer shaft. When the integration of the inner shaft and the outer shaft is released, the inner shaft is A shift control device for a continuously variable transmission with an infinitely variable gear ratio, comprising: a GNP forced return structure forcibly moving to a position of a geared neutral point. 2. The speed change control device for a continuously variable transmission with an infinite speed ratio according to claim 1, wherein the engagement / disengagement structure of the step motor is a means using a clutch that performs engagement / disengagement in response to an external command. During normal shift control, when the clutch is engaged, the inner shaft and the outer shaft are integrated, and when the deceleration of the drive wheels is large through the infinitely variable speed ratio transmission in which the power path is mechanically coupled, A shift control device for a continuously variable transmission with an infinite gear ratio, comprising: clutch release control means for releasing the integration of the inner shaft and the outer shaft by releasing the clutch. 3. The shift control device for a continuously variable transmission with an infinite speed ratio according to claim 1, wherein the engagement / disengagement structure of the step motor forms an axial groove and a circumferential groove communicating with each other on the inner shaft. The outer shaft is provided with a pin at its inner circumferential position for engaging with the axial groove and the circumferential groove, and the speed change link connecting portion at the inner shaft end receives an axial force received from the power roller to rotate the inner shaft. A linear-rotation conversion mechanism that converts the force into force is provided.When the axial force is less than the set value, the inner shaft and the outer shaft are integrated by maintaining the pin engagement with the circumferential groove, and the axial force is reduced. When the value is equal to or greater than the set value, the means is a means for releasing the integration of the inner shaft and the outer shaft by shifting to a pin engagement from the circumferential groove to the axial groove, wherein the gear ratio is infinitely variable. Gear shift control device. 4. The shift control device for an infinitely variable speed ratio transmission according to claim 1, wherein the GNP forced return structure of the step motor has an inner end connected to a speed change link at one end thereof. Geared to axis
A shift control device for a continuously variable transmission with an infinitely variable transmission ratio, wherein said transmission control device has a structure having an elastic body that applies an urging force to move to a position of a neutral point. 5. The transmission control device for a continuously variable transmission with an infinitely variable gear ratio according to claim 4, wherein the GNP forced return structure of the step motor has a structure in which the inner shaft is driven by an urging force of an elastic body during forced return. A shift control device for a continuously variable transmission with an infinite transmission ratio, wherein the shift control device has a position regulating member that regulates movement past the position of the neutral point and maintains the inner shaft at the geared neutral point.