JPH07151218A - Speed change control device for toroidal type continuously variable transmission - Google Patents

Abstract

PURPOSE:To restrict any displacement of a trunnion for supporting a power roller even when the power roller receives a tangential force from an input disc and an output disc while transmitting torque. CONSTITUTION:Control is carried out by outputting, a control signal responding to the neutral position of a spool valve 10 calculated from a target speed ratio and an input torque value and a control signal responding to a deviation between the target speed ratio and an actual speed ratio, to solenoid valves 13a, 13b. Even if a tangential force F acts on a trunnion 4, the trunnion 4 is maintained at its neutral position by generating a pressure difference counterbalancing the tangential force F in cylinder rooms 8a, 8b, and is not allowed to begin a speed change again after the speed change terminates, when the trunnion 4 receives a tangential force F from an input disc 3 and an output disc while transmitting torque.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention continuously changes the rotation of an input disk according to a tilt angle with respect to an input disk and an output disk which are arranged opposite to each other, and transmits the rotation to the output disk. The present invention relates to a speed change control device for a toroidal type continuously variable transmission including a speed change unit including a pair of power rollers.

[0002]

2. Description of the Related Art As a toroidal type continuously variable transmission mounted on an automobile, a double cavity type toroidal type continuously variable transmission in which two transmission units are arranged on the same axis is generally used. This toroidal type continuously variable transmission is
An input shaft to which an engine output is input, a pair of input disks rotatably supported with respect to the input shaft, and a pair of rotatably supported with respect to the input shaft, arranged to face each of the input disks. Output disc, a pair of opposing input discs, a tiltable power roller arranged between the output discs and transmitting torque from the input discs to the output disc, and a pair of opposing output discs are integrally connected to each other. A connecting member, a pair of flanges provided on the input shaft, and a pressing means arranged between the input disc and acting on each of the input discs to change the pressure contact force of the power roller according to the magnitude of the input torque. By tilting the power roller, the rotation of the input disk can be steplessly changed and transmitted to the output disk according to the tilt angle. It has been made.

In the toroidal type continuously variable transmission as described above, the tilting of the power roller is performed by the shift control device. Various speed change control devices have been conventionally used (Japanese Patent Laid-Open No. 61-82065 and Japanese Patent Laid-Open No. 63-20395).
No. 7) is known, and there is, for example, a shift control device as shown in FIG. Note that FIG. 4 shows the shift control device for one shift unit for the sake of simplicity. However, in the case of a double-cavity toroidal type continuously variable transmission, hydraulic pressure is another shift unit. The description will be omitted because it is only necessary that the hydraulic cylinder can be supplied to the hydraulic cylinder.

As shown in FIG. 4, a pair of power rollers 2 and 2 in the transmission unit 1 face each other so as to be sandwiched between an input disk 3 and an output disk (not shown) which are arranged to face each other. They are arranged and rotatably supported by support members called trunnions 4 and 4, respectively.
That is, the power rollers 2 and 2 are supported by the trunnions 4 and 4 by the eccentric shafts 5 and 5. The trunnions 4 and 4 are rotatably and axially supported by a transmission casing (not shown). That is, each of the trunnions 4 and 4 has the tilting shafts 6 and 6, and can move in the axial direction of the tilting shafts 6 and 6 and can rotate about the tilting shafts 6 and 6. it can. Pistons 7, 7 are fixed to the tilting shafts 6, 6 of the trunnions 4, 4, and the pistons 7, 7 are slidably provided in hydraulic cylinders 8, 8 formed in the transmission casing. There is. Two cylinder chambers 8a, 8b defined by the pistons 7, 7 are formed in the hydraulic cylinders 8, 8.

Each cylinder chamber 8a of the hydraulic cylinders 8,
8b communicates with the spool valve 10 by the pipe lines 9a and 9b. Spool 11 arranged in the spool valve 10
Are held in the neutral position by springs 12 arranged at both ends in the axial direction. The spool valve 10 has Sa at one end.
A port is formed, an Sb port is formed at the other end, pilot pressure is supplied to the Sa port via the solenoid valve 13a, and the Sb port is connected to the solenoid valve 13b.
Pilot pressure is supplied via. Further, the spool valve 10 has a P port connected to the pilot pressure and a pipe line 9a.
A port connected to the cylinder chamber 8a through the pipe 9
It has a B port connected to the cylinder chamber 8b via b and a T port connected to the drain. The solenoid valves 13a and 13b are configured to operate according to a control signal output from the controller 14.

A precess cam 1 is provided at the tip of one tilting shaft 6.
5 are connected to each other, one end of a lever 16 pivotally attached to the central portion abuts on the recess cam 15, and the other end of the lever 16 is connected to a potentiometer 17. The potentiometer 17 detects an axial displacement and a tilt angle of the tilt shaft 6 of the trunnion 4 as a combined displacement amount, and inputs a detection signal to the controller 14. Further, in addition to this, the shift control device also includes a vehicle speed sensor 18, an engine rotation sensor 19, a throttle opening sensor (TPS) 20.
Various sensors such as the above are provided, and the shift information signals such as the vehicle speed, the engine speed, and the throttle opening detected by these sensors are input to the controller 14.

In the toroidal type continuously variable transmission, the trunnions 4 and 4 are tilted from the neutral position (the position where the rotation center axes of the power rollers 2 and 2 intersect the rotation center axes of the input disc 3 and the output disc) to either one. When the trunnions 4 and 4 are displaced in the direction of the axis of rotation (that is, the axial direction of the tilt axis), the trunnions 4 and 4 tilt around the tilt axes 6 and 6 at a direction and speed corresponding to the direction and the amount of displacement. The shift control is performed by utilizing the property that the shift is performed by.

Next, the operation of the shift control device will be described. First, the controller 14 calculates the actual gear ratio from the combined displacement amount of the trunnions 4 and 4 detected by the potentiometer 17, and the gear ratio and the target gear ratio. The target displacements of the trunnions 4 and 4 are set in accordance with the deviation between and, and a control signal is output to the solenoids 13a and 13b. Along with this, the hydraulic pressures Sa and Sb are supplied from the solenoid valves 13a and 13b to both ends of the spool valve 10. At that time, the relation between the hydraulic pressures Sa and Sb supplied to the spool valve 10 is Sa> Sb.
4, the spool 11 is shifted to the left side in FIG. 4, the pipe line 9a communicates with the pressure source P through the P port, the pipe line 9b communicates with the drain through the T port, and
The pressure Pa of a becomes larger than the pressure Pb of the pipe line 9b (Pa> Pb). As a result, the left trunnion 4 is displaced downward and the right trunnion 4 is displaced upward in FIG. 4 due to the pressure difference between the cylinder chambers 8a and 8b. In accordance with this displacement, the trunnions 4 and 4 are respectively tilted shafts 6 and 6.
Tilting around, the gear shift operation is started. Then, the controller 14 is operated so that the actual gear ratio approaches the target gear ratio.
Feedback control is performed by. As the actual gear ratio approaches the target gear ratio, the target displacements of the trunnions 4, 4 approach zero, and when the actual gear ratio matches the target gear ratio, the target displacements of the trunnions 4, 4 become zero. The gear shifting operation ends.

[0009]

According to the above conventional shift control device, when the actual gear ratio matches the target gear ratio and the target displacements of the trunnions 4 and 4 are zero, both ends of the spool valve 10 are connected. The pressures become equal (Sa = Sb),
The spool 11 of the spool valve 10 returns to the neutral position, and the pressures of the two cylinder chambers 8a and 8b become equal (Pa =
Pb).

However, during torque transmission, the power rollers 2, 2 receive a tangential force F from the input disk 3 and the output disk in the direction of arrow F shown in FIG. This tangential force F
When the power rollers 2 and 2 receive
The trunnions 4 and 4 supporting 2 are slightly displaced in the tilt axis direction by receiving the tilt axis direction force F corresponding to the transmission torque and the gear ratio. As a result, the axial displacement of the tilt shaft 6 provided integrally with the trunnions 4 and 4 is detected by the potentiometer 17, and the controller 14 sends a control signal to the solenoid valve 13 in order to restart the gear shift.
It will be output to a and 13b. In this way, the conventional shift control device is
When the tangential force F is received, the gear shift is restarted, the gear shift control is not stable, and the gear shift efficiency is lowered. Therefore, there is a problem that the heat generation amount is increased by the repeated side slips. there were.

Therefore, in order to solve the above problem, when the tangential force F acts on the power roller, pressure is applied to the piston so as to cancel the tangential force F so that the trunnion is not displaced in the tilt axis direction. It is only necessary to solve the problem of configuring.

The present invention solves the above problems and, even if the power roller receives a tangential force from the input disk and the output disk during torque transmission, the trunnion supporting the power roller is not displaced and a stable gear ratio is improved. An object of the present invention is to provide a shift control device for a toroidal type continuously variable transmission that can be efficiently obtained and generates less heat.

[0013]

In order to achieve the above object, the present invention is configured as follows. That is, according to the present invention, the input disc and the output disc that are arranged to face each other, and a pair of the transmission of the rotation of the input disc that is steplessly changed according to the change of the tilt angle with respect to the both discs. A power roller, a pair of trunnions rotatably supporting the power roller and tilting about a tilt axis from a neutral position, a hydraulic cylinder having two cylinder chambers and displacing the trunnion in the tilt axis direction, A spool valve that shuts off the cylinder chambers in the neutral position and connects the cylinder chambers to the hydraulic pressure source and the tank in the displaced state from the neutral position, respectively.
A solenoid valve for controlling the spool position of the spool valve, and a control signal according to the neutral position of the spool valve calculated from the target speed ratio and the input torque value, and control according to the deviation between the target speed ratio and the actual speed ratio. A controller for controlling the operation of the solenoid valve in response to a signal, and a shift control device for a toroidal-type continuously variable transmission.

In the shift control device for the toroidal type continuously variable transmission, the controller inputs the detection value relating to the shift information detected by the shift information detector to calculate the input torque value, the input torque calculating means, Target speed ratio calculating means for inputting a detected value related to speed change information and calculating a target speed ratio, and speed ratio calculating means for inputting a combined displacement amount of the tilt shaft of the trunnion detected by a potentiometer to calculate an actual speed ratio. Spool valve neutral position calculating means for calculating the neutral position of the spool valve according to the magnitude of the tangential force received by the trunnion based on the input torque value and the target transmission ratio, the target transmission ratio and the actual transmission Deviation calculating means for calculating the deviation of the ratio, and the solenoid valve by setting a control signal according to the neutral position and a control signal according to the deviation And it has a solenoid valve operation control means for outputting.

Here, the shift information detector means a sensor such as an engine rotation sensor for detecting the engine speed, a throttle opening sensor for detecting the throttle opening, a vehicle speed sensor for detecting the vehicle speed, and the like. is there. The input torque value is calculated by experimentally obtaining the relationship between the engine speed, the throttle opening, and the input torque value, storing this in the controller as a map, that is, a table, and using this table. Alternatively, it may be calculated by the controller based on the detection value detected by the sensor. In calculating the input torque value, an engine suction negative pressure or a torque sensor may be used.

The solenoid valve may be a duty valve, a proportional valve or the like as long as it can electrically control the hydraulic pressure, and may be a two-way valve or a three-way valve. Further, the solenoid valve may be any one that can supply hydraulic pressure to both ends of the spool valve. Therefore, one solenoid valve may be connected to each end of the spool valve. Alternatively, one solenoid valve may be connected to only one end of the spool valve, and a constant hydraulic pressure may be applied to the other end of the spool valve, or a spring may be provided at the other end. In that case, the spring force needs to be set high.

Alternatively, according to the present invention, as a direct-acting type speed change control device, the input disc and the output disc, which are arranged to face each other, and the rotation of the input disc is continuously changed according to the change of the tilt angle with respect to the both discs. A pair of power rollers for shifting the speed to be transmitted to the output disc and a pair of trunnions for rotatably supporting the power rollers and displacing in the tilt axis direction from the neutral position, A hydraulic cylinder that has two cylinder chambers and that displaces the trunnion in the tilt axis direction; a solenoid valve that controls the hydraulic pressure supplied to the two cylinder chambers;
And a controller that controls the solenoid valve in response to a control signal according to the magnitude of the tangential force received by the trunnion from both the disks and a control signal according to the deviation between the target gear ratio and the actual gear ratio. The present invention relates to a shift control device for a toroidal-type continuously variable transmission.

That is, the toroidal type continuously variable transmission is constructed so that the hydraulic pressure is supplied to the cylinder chamber of the hydraulic cylinder via the spool valve, and the trunnion is displaced in the tilt axis direction accordingly. Although the pilot drive system is adopted, a direct drive system in which the hydraulic pressure supplied to the cylinder chamber is directly controlled by a solenoid valve may be adopted. In the case of the direct-acting type shift control device, the hydraulic pressure supplied to each cylinder chamber is equal to the hydraulic pressure supplied to both ends of the spool valve in the pilot drive system.

[0019]

Since the present invention is constructed as described above,
It works as follows. First, a pilot drive type shift control device according to the present invention will be described. As described above, the controller sends the control signal corresponding to the neutral position of the spool valve calculated from the target gear ratio and the input torque value and the control signal corresponding to the deviation between the target gear ratio and the actual gear ratio to the solenoid valve. It is configured to output. That is, this controller is the same as the above-mentioned conventional controller in that it outputs a control signal corresponding to the deviation to the solenoid valve, but it determines the neutral position of the spool valve from the target gear ratio and the input torque value and The difference is that a control signal corresponding to the position is also output to the solenoid valve. Therefore, since the neutral position of the spool valve is shifted from the original neutral position, when a control signal corresponding to the deviation is output to the solenoid valve, a pressure difference occurs between the two cylinder chambers. This pressure difference cancels out the tangential force that the trunnion receives from the input disk and the output disk, so that the trunnion is maintained at the neutral position in the tilt axis direction and does not start shifting again.

The operation of the above controller will be described more concretely. First, the target speed ratio calculating means calculates the target speed ratio, and the input torque calculating means calculates the input torque value based on the detected values relating to various information detected by the speed change information detector. Then, the spool valve neutral position calculation means calculates the neutral position of the spool valve according to the magnitude of the tangential force received by the trunnion from the target gear ratio and the input torque value.

On the other hand, the gear ratio calculating means calculates the actual gear ratio from the combined displacement amount of the trunnions detected by the potentiometer. Then, the deviation calculation means calculates the deviation between the target speed ratio and the actual speed ratio.

The solenoid valve operation control means sets a control signal according to the neutral position of the spool valve calculated by the spool valve neutral position calculating means, and sets a control signal according to the deviation calculated by the deviation calculating means, The sum of these control signals is output to the solenoid valve.

When a control signal is input to the solenoid valve from the solenoid valve actuation control means, a hydraulic pressure difference is generated between the solenoid valve and both ends of the spool valve, and the spool is displaced to a position where the hydraulic pressure difference and the spring force are balanced. According to the displacement of the spool, the hydraulic pressure P is supplied to one cylinder chamber of the hydraulic cylinder, and the other cylinder chamber communicates with the drain. As a result, the piston moves, and the trunnion is displaced in the tilt axis direction from the neutral position. When the trunnion is displaced from the neutral position, the power roller receives the force in the velocity vector direction from the input disc and the output disc and begins to tilt with the displacement.

Then, as the gear ratio approaches the target gear ratio, the target displacement of the trunnion approaches zero, and when the gear ratio matches the target gear ratio, the target displacement of the trunnion becomes zero, the spool valve is closed, and the hydraulic pressure is reduced. The supply of hydraulic pressure to the output is stopped, and the gear shift ends. At this time, although the hydraulic pressures of the two cylinder chambers do not match, the tangential force received by the trunnion from the input / output disk and this hydraulic pressure difference cancel each other out, so that the trunnion is maintained in the neutral position and the gear shift is not started again.

Also, the direct drive type speed change control device according to the present invention is similar to the pilot drive type speed change control device, and the tangential force that the trunnion receives from the input disk and the output disk is the hydraulic pressure difference between the two cylinder chambers. The trunnion is maintained in the neutral position and does not start shifting again.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a shift control device for a toroidal type continuously variable transmission according to the present invention will be described below with reference to the drawings. 1 is a block diagram showing an embodiment of a shift control device according to the present invention, FIG. 2 is a flowchart showing a procedure of shift control in the shift control device of FIG. 1, and FIG.
6 is a flowchart showing a procedure for setting a solenoid valve control signal in the shift control device of FIG. Further, the shift control device for a toroidal-type continuously variable transmission according to the present invention has substantially the same configuration as the conventional one shown in FIG. 4 except for the configuration of the controller, and therefore, the same reference numerals are given to the same parts. Therefore, detailed description will be omitted.

The controller 21 of this shift control device is
As shown in FIG. 1, input torque calculation means 23 for calculating the input torque value by inputting the detection value related to the shift information detected by the shift information detector 22 and the detection value related to the shift information detected by the shift information detector 22. A target gear ratio calculating means 24 for inputting and calculating a target gear ratio, a combined displacement amount of the tilt shafts 6, 6 of the trunnions 4, 4 detected by the potentiometer 17, that is, an axial displacement and tilt of the tilt shafts 6, 6. The gear ratio calculation means 25 for calculating the actual gear ratio by inputting the combined displacement amount with the tilt angles of the rolling shafts 6, 6, the input torque value input from the input torque calculation means 23, and the target gear ratio calculation means 24. Spool valve neutral position calculating means 26 for calculating the neutral position of the spool valve 10 according to the magnitude of the tangential force F received by the trunnions 4, 4 based on the target speed ratio input from Deviation calculating means 27 for calculating a deviation of the input target speed ratio and the actual gear ratio input from the speed change ratio computing unit 25, the spool valve neutral position calculating means 2
6 sets a control signal corresponding to the neutral position of the spool valve input from 6 and sets a control signal corresponding to the deviation input from the deviation calculating means 27, and sums the control signals to the solenoid valves 13a and 13b. It has a solenoid valve operation control means 28 for outputting to.

The shift information detector 22 is composed of a vehicle speed sensor 18 for detecting a vehicle speed, an engine rotation sensor 19 for detecting an engine speed, a throttle opening sensor 20 for detecting a throttle opening, and the like.

The input torque calculating means 23 previously obtains the relationship between the engine speed, the throttle opening and the input torque value by experiments, and stores this as a table. Then, the input torque calculation means 23 uses the engine rotation sensor 1
The engine speed detected in 9 and the throttle opening detected by the throttle opening sensor 20 are input, and the input torque value is obtained using the stored table.

The target gear ratio calculating means 24 is provided for each sensor 1
The optimum gear ratio determined by the vehicle speed, engine speed, throttle opening, etc. detected in 8, 19, and 20 is calculated and set as the target gear ratio.

The gear ratio calculating means 25 inputs the combined displacement amount of the trunnion detected by the potentiometer and calculates the actual gear ratio. Since the combined displacement amount of the potentiometer when the power rollers 2 and 2 are in the neutral position and the gear ratio is 1 is used as a reference, the gear ratio is calculated from the tilt angle when the power rollers 2 and 2 are in the neutral position. can do.

The spool valve neutral position calculation means 26 inputs the input torque value calculated by the input torque calculation means 23 and the target speed change ratio calculated by the target speed change ratio calculation means 24, and the trunnions 4, 4 input the disk 3 and the input disk 3. The neutral position of the spool valve 10 according to the magnitude of the tangential force F received from the output disk is calculated. The spool valve neutral position calculation means 26
Stores a relationship between the target gear ratio, the input torque value, and the spool valve neutral position, which is obtained in advance by an experiment, as a table.

The deviation calculating means 27 calculates a deviation between the target speed ratio calculated by the target speed ratio calculating means 24 and the actual speed ratio calculated by the speed ratio calculating means 25.

The solenoid valve actuation control means 28 sets a control signal corresponding to the spool valve neutral position input from the spool valve neutral position calculating means 26, and at the same time, outputs a control signal according to the deviation input from the deviation calculating means 27. Set
The sum of these control signals is output to the solenoid valves 13a and 13b.

Next, the procedure of the shift control in this shift control device will be described with reference to the flowchart of FIG. Before the gear shifting operation is started, the trunnions 4, 4
Is the center of rotation of the power rollers 2 and 2 and the input disk 3
And the center axis of rotation of the output disk intersects, so-called neutral position (START).

(1) Calculation of target gear ratio (step 1):
The shift information detector 22 detects shift information such as engine speed, throttle opening, vehicle speed, and the like. Based on the detected gear shift information, the target gear ratio calculation means 24 calculates an optimum gear ratio and sets it as the target gear ratio e ₀ .

(2) Calculation of actual gear ratio (step 2): In this state, first, the potentiometer 17
Thus, the combined displacement amount of the tilting shaft 6 of the trunnion 4 is detected. The actual gear ratio e at the present time is calculated from this combined displacement amount.

(3) Deviation calculation (step 3): The deviation (e ₀ -e) between the actual gear ratio e calculated in step 1 and the target gear ratio e ₀ calculated in step 2 is calculated.

(4) Judgment as to whether or not shift control is completed (step 4): It is judged whether or not the deviation is zero.
If the deviation is zero, it means that the target gear ratio e ₀ has already been achieved, so the gear shift control ends (EN
D). If the deviation is not zero, the process proceeds to the next step 5, and the shift control is continued.

(5) Setting of control signal output to solenoid valve (step 5): Setting of control signal output to solenoid valves 13a and 13b will be described later.

(6) Solenoid valve operation (step 6):
The control signals τ _a and τ _b set in step 5 are output from the controller 21 to the solenoid valves 13a and 13b. For example, the case of deceleration will be described. By inputting the control signals τ _a and τ _b , the solenoid valves 13a and 13a
b is actuated, the pressure applied to both ends of the spool valve 10 is Sa
> Sb, so that the spool valve 10
One of the cylinder chambers 8a of the hydraulic cylinder 8 is communicated with the P port through which a hydraulic pressure is supplied, and the other cylinder chamber 8a
b communicates with the tank. This allows the trunnions 4, 4
Is displaced from the neutral position in the axial direction of the tilt axis by a predetermined amount.
When the speed is greatly reduced, the displacement amount in the tilt axis direction is large, and when the speed is slightly reduced, the displacement amount in the tilt axis direction is small. When the trunnion 4 is displaced in the tilt axis direction, the power rollers 2 and 2 start to tilt by receiving a force in the velocity vector direction from the input disk 3 and the output disk.

(7) Feedback control (step 6 →
Step 2): Subsequently, the gear ratio e is calculated from the combined displacement amount detected by the potentiometer 17 (step 2), and the deviation between the gear ratio e and the target gear ratio e ₀ calculated in step 1 is calculated ( In step 3), it is judged whether or not the deviation is zero (or within a minute predetermined range) (step 4). When the deviation is not zero, the control signal τ to the solenoid valves 13a and 13b is again set.
_a and τ _b are set, and this is the solenoid valve 13a,
13b (step 5), the solenoid valve 13
a and 13b are controlled and operated (step 6). By repeating this control, the deviation approaches zero, and the trunnions 4, 4 gradually return to the neutral position accordingly. Then, the shift operation ends when the deviation becomes zero. As the gear ratio approaches the target gear ratio, the control signals τ _a and τ _b to both solenoid valves 13a and 13b approach τ _{a 0} and τ _{b 0} , respectively, and when the gear shift ends, τ
Matches _{a 0} and τ _{b 0} .

In this feedback control, the control signals τ _a and τ _b are sent to the solenoid valves 13a and 13b with _a predetermined feedback gain. The feedback gain does not have to be fixed, and may be controlled to change depending on, for example, the gear ratio, the input rotation speed, the output rotation speed, or the like. Further, the differential value and integrated value of the deviation may be fed back.

Next, the procedure for setting the control signal to be output to the solenoid valves 13a and 13b will be described with reference to the flowchart of FIG. (1) Input torque calculation (step 7): The engine rotation speed detected by the engine rotation sensor 19 and the throttle opening detected by the throttle opening sensor 20 are input to the input torque calculation means 23, and the engine rotation speed and the throttle opening are opened. Input torque calculation means 23 based on a table which is obtained by experiments and stored beforehand regarding the relationship between the degree and the input torque value.
Calculates the input torque value T.

(2) Setting of spool valve neutral position (step 8): Steps based on a table stored beforehand regarding the relationship between the target gear ratio e ₀ , the input torque value T and the spool valve neutral position x ₀ The target gear ratio e ₀ calculated in 1 and the input torque value T calculated in step 7 are input to the spool valve neutral position calculation means 26, and the tangential force F received by the trunnions 4 and 4 from the input disk 3 and the output disk is input. The neutral position x ₀ of the spool valve 10 according to the size, that is, x ₀ = f _x (T, e ₀ ) is calculated.

(3) Setting of control signal according to neutral position of spool valve (step 9): Solenoid valve 13a, depending on neutral position x ₀ of spool valve 10 calculated in step 8
The control signals τ _{a 0} and τ _{b 0} output to 13b, that is, τ _{a 0} = f _a (x ₀ ) τ _{b 0} = f _b (x ₀ ) are set. Here, since the neutral position of the spool valve 10 is shifted to the right side in FIG. 4 from the original neutral position, there is a relationship of τ _{a 0} <τ _{b 0} .

(4) Setting of control signal according to deviation (step 10): Control signal Δτ output to the solenoid valves 13a and 13b according to the deviation calculated in step 3, that is, Δτ = G (e ₀ -E) is set. Here, G is a coefficient.

(5) Setting of control signal output to solenoid valve (step 11): Sum τ _a , τ _{b of} control signals set in step 9 and step 10, that is, τ _a = τ _{a 0} −Δτ τ Set _b = τ _{b 0} + Δτ. Then, the set control signals τ _a and τ _b are output to the solenoid valves 13a and 13b (step 6).

Now, returning to the procedure of the shift control shown in FIG. 2, the shift control will be concretely described again. When the actual gear ratio e is larger than the target gear ratio e ₀ (e ₀
-E <0), that is, the case of deceleration control will be described. In this case, the relationship between the control signals τ _a and τ _b is
Since τ _a > τ _b , the relationship between the pressures Sa and Sb applied to both ends of the spool valve 10 is Sa> Sb. Therefore,
Since the hydraulic pressure is supplied to the cylinder chamber 8a and the hydraulic pressure is discharged from the cylinder chamber 8b, the trunnions 4 and 4 are displaced in the direction away from the neutral position (in FIG. 4, the trunnion on the right side is upward and the trunnion on the left side is downward. Displaced in the direction). With this displacement, the trunnions 4 and 4 start to tilt, so that the deviation (e ₀ −e) becomes smaller. Meanwhile, the feedback control of steps 2 to 6 of FIG. 2 is repeated. Then, when τ _a <τ _b , the relationship between the pressures Sa and Sb applied to both ends of the spool valve 10 reverses to Sa <Sb, so that the hydraulic pressure to the cylinder chamber 8b is reversed. Is supplied, the hydraulic pressure is removed from the cylinder chamber 8a, and the trunnions 4 and 4 return toward the neutral position. Then, as the feedback control is repeated, the gear ratio e eventually becomes equal to the target gear ratio e ₀ , and the spool valve 10 is closed. At that time, the trunnions 4 and 4 are in the neutral position in balance with the tangential force F. The control signals τ _a and τ _b output to the solenoid valve are τ _a = τ _{a 0} and τ _b = τ _{b 0} , respectively. When the gear ratio e is smaller than the target gear ratio e ₀ (e ₀ −e>
0), that is, the case of performing the speed-up control is the reverse of the case of the above-described deceleration control, and thus the description thereof is omitted.

As described above, the controller 21 controls the control signals τ _{a 0} and τ _{b 0} according to the neutral position of the spool valve calculated from the target gear ratio e ₀ and the input torque value T, the target gear ratio e ₀ and the actual value. Control signal Δτ according to the deviation from the gear ratio e of
And τ _a and τ _b are output to the solenoid valves 13a and 13b. That is, this controller 2
1 is a solenoid valve 13 which outputs a control signal Δτ corresponding to the deviation.
Although the output to a and 13b is the same as that of the conventional controller 21, the neutral position x ₀ of the spool valve 10 is obtained from the target gear ratio e ₀ and the input torque value T, and the control signal τ corresponding to the neutral position is obtained. _{The a 0} and τ _{b 0} are also output to the solenoid valves 13a and 13b together. Therefore, when the tangential force F is applied, the neutral position x ₀ of the spool 11 is set to be shifted to the right of the original neutral position in FIG. 4, so that the hydraulic pressure supplied to the cylinder chamber 8b is supplied. The amount is slightly larger than the hydraulic pressure supply amount supplied to the cylinder chamber 8a. Therefore, when the tangential force F is acting, the two cylinder chambers 8a, 8b are
Is caused by a hydraulic pressure difference (Pa <Pb), and the tangential force F received by the trunnions 4 and 4 from the input disc 3 and the output disc cancels each other out, so that the trunnions 4 and 4 are maintained at the neutral position and are again restored. It never starts shifting. Therefore, since unnecessary gear shifting is not performed after the gear shifting ends, the amount of heat generated due to the side slip of the power rollers 2 and 2 at the time of gear shifting is suppressed to the minimum.

[0051]

Since the present invention is constructed as described above, it has the following effects. That is, the shift control device for the toroidal continuously variable transmission responds to the control signal corresponding to the neutral position of the spool valve calculated from the target gear ratio and the input torque value and the deviation between the target gear ratio and the actual gear ratio. When the trunnion receives a tangential force F from the input disk and the output disk during torque transmission, the pressure difference that cancels the tangential force F is applied to the two cylinders. Since the trunnion is generated in the chamber, even if the tangential force F acts on the trunnion, the trunnion is maintained in the neutral position, and the unnecessary gear shift is not started after the gear shift is completed. Therefore, a stable gear ratio can be maintained during torque transmission, and heat generation due to side slip of the power roller is reduced by the amount of unnecessary and unnecessary gear shift unlike the conventional art, resulting in a highly efficient toroidal. It becomes possible to provide a continuously variable transmission.

[Brief description of drawings]

FIG. 1 is a block diagram of a shift control device for a toroidal type continuously variable transmission according to the present invention.

FIG. 2 is a flowchart showing a procedure of shift control in the shift control device of FIG.

3 is a flowchart showing a procedure for setting a solenoid valve control signal in the shift control device of FIG.

FIG. 4 is a cross-sectional view showing a shift control device for a conventional toroidal type continuously variable transmission.

[Explanation of symbols]

 1 Transmission Unit 2 Power Roller 3 Input Disc 4 Trunnion 6 Tilting Shaft 8 Hydraulic Cylinders 8a, 8b Cylinder Chamber 13a, 13b Solenoid Valve 17 Potentiometer 21 Controller 22 Shift Information Detector 23 Input Torque Calculator 24 Target Speed Ratio Calculator 25 Speed Ratio calculation means 26 Spool valve neutral position calculation means 27 Deviation calculation means 28 Solenoid valve operation control means

Claims (3)

[Claims] 1. An input disk and an output disk, which are arranged to face each other, and a pair of powers for continuously changing the rotation of the input disk in response to changes in a tilt angle with respect to the both disks and transmitting the rotation to the output disk. Roller, a pair of trunnions that rotatably support the power roller and tilt around a tilt axis from a neutral position, a hydraulic cylinder that has two cylinder chambers, and that displaces the trunnion in the tilt axis direction, a neutral A spool valve that shuts off the cylinder chamber in the state of being in a position and communicates each cylinder chamber with a hydraulic source and a tank in a state of being displaced from the neutral position, a solenoid valve that controls the spool position of the spool valve, and Of the control signal corresponding to the neutral position of the spool valve calculated from the target gear ratio and the input torque value, the target gear ratio, and the actual gear ratio. A shift control device for a toroidal-type continuously variable transmission, comprising: a controller that controls the operation of the solenoid valve in response to a control signal corresponding to the deviation. 2. The controller is configured to input a detection value related to shift information detected by a shift information detector to calculate an input torque value, and input a detection value related to the shift information to a target gear ratio. Target gear ratio calculating means for calculating, gear ratio calculating means for calculating the actual gear ratio by inputting the combined displacement amount of the tilt shaft of the trunnion detected by the potentiometer, based on the input torque value and the target gear ratio A spool valve neutral position calculating means for calculating a neutral position of the spool valve according to a magnitude of a tangential force received by the trunnion, a deviation calculating means for calculating a deviation between the target speed ratio and the actual speed ratio, and the neutral position. It has a solenoid valve operation control means for setting a control signal according to the position and a control signal according to the deviation and outputting the control signal to the solenoid valve. The shift control device for the toroidal type continuously variable transmission according to claim 1. 3. An input disk and an output disk, which are arranged to face each other, and a pair of powers for continuously changing the rotation of the input disk in response to a change in a tilt angle with respect to the both disks and transmitting the rotation to the output disk. The roller and the power roller are rotatably supported, and have a pair of trunnions that tilt around the tilt axis by displacing from the neutral position in the tilt axis direction, and have two cylinder chambers and tilt the trunnion. A hydraulic cylinder that is displaced in the axial direction, a solenoid valve that controls the hydraulic pressure supplied to the two cylinder chambers, a control signal according to the magnitude of the tangential force that the trunnion receives from the two disks, and the target gear ratio and the actual gear shift. A toroidal controller configured to control the solenoid valve in response to a control signal corresponding to a deviation from the ratio Type continuously variable transmission shift control device.