JPH09210164A - Toroidal type continuously variable transmission - Google Patents

Abstract

The present invention provides a toroidal type that uses an electromagnetic solenoid of low resolution and enables fine control equivalent to the case of using an electromagnetic solenoid of high resolution by performing feedback control with a position signal of a sleeve. Provide a continuously variable transmission. SOLUTION: This toroidal type continuously variable transmission is provided with a sleeve position sensor 22 for detecting a position of a sleeve 11 having a resolution higher than that of an electromagnetic solenoid 19, and a target sleeve position of the sleeve 11 is set according to a target gear ratio. Setting, the actual position of the sleeve 11 is detected by the sleeve position sensor 22, and the electromagnetic solenoid 19
Is corrected by the difference between the target sleeve position and the actual sleeve position, the corrected duty control value is output, and the position of the sleeve 11 that determines the gear ratio is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal type continuously variable transmission having a sleeve for controlling hydraulic pressure provided in a control valve for controlling a gear ratio.

[0002]

2. Description of the Related Art Generally, a toroidal type continuously variable transmission includes a toroidal transmission unit 1 as shown in FIG. The toroidal transmission unit 1 of the toroidal type continuously variable transmission continuously rotates the input disk 2 in response to a change in the tilt angle with respect to the input disk 2 and the output disk 3, and the disks 2 and 3, which are arranged to face each other. A pair of power rollers 4 (only one of which is shown) that changes speed and transmits to the output disk 3, and a pair of trunnions 6 (only one of which supports the power roller 4 rotatably and can be tilted about a tilt shaft 5). (Illustration).

Normally, the trunnion 6 is in the neutral position at a certain gear ratio. That is, the trunnion 6 is at a position where the rotation center line A-A of the input disk 2 and the output disc 3 and the rotation center line BB of the power roller 4 intersect (= neutral position).
It is in. Gear shifting is performed by displacing the trunnion 6 from the neutral position in the axial direction of the tilt shaft 5. When the trunnion 6 is displaced in the tilt axis direction, the trunnion 6 is tilted around the tilt axis 5 in a direction and at a speed corresponding to the displacement direction and the displacement amount, and the trunnion 6 is moved to the input disk 2 and the power roller 4. Radius drawn by the contact points of the output disk 3 and the power roller 4
Gear shifting is performed by changing the ratio with the radius drawn by the contact point with.

In the toroidal type continuously variable transmission, for example, the tilting drive of the power roller 4 is performed by the control valve 10.
The control valve 10 is driven by an electromagnetic solenoid control device, and various types are known in the related art. For example, as shown in FIG. 3, the control valve 10 is slidably arranged in a hole formed in the valve case 12. The sleeve 1 and the spool 13 slidably inserted through the sleeve 11 with the return spring 16 interposed therebetween are displaced integrally with the trunnion 6 and the spool 1
Precess cam 18 for displacing 3 in the axial direction, spool 1
3 and the sleeve 11 are displaced relative to each other in the axial direction, whereby hydraulic pressure is supplied or discharged to displace the trunnion 6 in the direction of the tilt axis 5, and the piston 7 is moved to displace the hydraulic cylinder 8 and the sleeve 11 in the axial direction. Therefore, a solenoid valve 21 that is operated to supply hydraulic fluid, an electromagnetic solenoid 19 that electromagnetically drives the solenoid valve 21 to operate the solenoid valve 21, and a controller 20 that sends a control signal according to a target gear ratio to the electromagnetic solenoid 19 are provided. I have it.

The spool 13 is slidably arranged in the sleeve 11, and a return spring 16 is provided between the sleeve 11 and the spool 13. The return spring 16 is in contact with one end of the spool 13, the spool 13 is biased to the right by a spring force, and the other end of the spool 13 is in contact with one end of a lever 17 pivotally attached to the other end of the lever 17. Is in contact with a precess cam 18 attached to the tip of the tilting shaft 5. Therefore, the spool 13
The trunnion 6 is displaced in the axial direction of the tilt shaft 5, or is displaced in the axial direction by rotating around the tilt shaft 5.

The electromagnetic solenoid 19 electromagnetically drives the solenoid valve 21, and the opening / closing drive of the solenoid valve 21 controls the magnitude of the hydraulic pressure sent through the pipe line 14 acting on the end portion of the sleeve 11. The solenoid valve 21 controls the magnitude of the pressure Ps acting on the left end of the sleeve 11 based on the output signal from the controller 20. The spool 13 is connected to a trunnion 6 supporting the power roller 4 via a recess cam 18 and a lever 17, and is held at a position corresponding to a combined value of the tilt angle of the trunnion 6 and the displacement in the direction of the tilt shaft 5. The solenoid valve 21 outputs a pressure Ps acting on the left end of the sleeve 11 based on a signal from the controller 20, and the sleeve 1 is operated by the pressure Ps.
1 is pushed to the right, return spring 1 to the left
The sleeve 11 is pushed by 5, and the sleeve 11 is controlled to a position where the forces applied to the sleeve 11 are balanced. Therefore, when hydraulic pressure acts on the left end of the sleeve 11 via the solenoid valve 19, the sleeve 11 moves to a position where the hydraulic pressure Ps and the force of the return spring 15 are balanced.

In the electromagnetic solenoid control device for the control valve 10, the controller 20 sends an output signal to the electromagnetic solenoid 19 of the solenoid valve 21 according to the target gear ratio. That is, as shown in the process flow chart of FIG. 4, the electromagnetic solenoid control is started, and the target gear ratio e ₀ is calculated based on the gear shift information in the main routine (step 11). When the target gear ratio e ₀ is calculated, the controller 20 calculates the duty according to the calculated target gear ratio e ₀ (step 12). When the duty is calculated,
The calculated duty is output to the solenoid valve 19 (step 13). Next, the electromagnetic solenoid control returns to the start of the main routine again (step 14).

Next, the operation of the toroidal type continuously variable transmission during shifting will be described. Hereinafter, the case of shifting to the deceleration side will be described with reference to FIG. (1) The solenoid valve 19 is actuated by a signal from the controller 20, the pressure Ps acts on the left end of the sleeve 11 through the conduit 14, and the sleeve 11 moves to the right of the state of FIG. The relative position between the sleeve 11 and the spool 13 changes, the communication passage between the Pd circuit and the PL circuit opens, and the line pressure PL is supplied from the hydraulic pressure source to the deceleration side cylinder chamber 8b through the pipe line 9b. On the other hand, the communication passage between the Pu circuit and the drain circuit is opened, and the hydraulic pressure in the acceleration side cylinder chamber 8a is drained to the tank through the pipe line 9a. As a result, (Pd hydraulic pressure)> (Pu hydraulic pressure), Trunnion 6
Offset downwards. At this time, the power roller 4 causes the arrow down about the tilt shaft 5 due to the side slip force.
Start tilting in the direction of. (2) As the power roller 4 tilts, the spool 1
3 is shifted to the right in FIG. 3 by a combined value of the displacement of the power roller 4 in the tilt axis direction and the tilt angle, and the communication path between the Pd circuit and the PL circuit and the communication path between the Pu circuit and the drain circuit are reduced. As a result, when the relative position between the sleeve 11 and the spool 13 becomes neutral, the hydraulic pressure of the Pd circuit and the hydraulic pressure of the Pu circuit become equal. (3) However, since the power roller 4 is still offset in the tilt axis direction in the above state, the power roller 4 continues tilting due to the side slip force. As a result, the spool 13 moves to the right of the neutral position with respect to the sleeve 11, and conversely, the communication path between the Pd circuit and the drain and the communication path between the Pu circuit and the PL circuit are opened, and Pd <Pu, and the trunnion 6 Is displaced upward, the displacement of the power roller 4 in the tilting axis direction becomes small, and the side slip force also weakens accordingly, and the tilting speed decreases. (4) As the trunnion 6 reciprocates up and down about the neutral position, the amplitude becomes smaller, the displacement of the power roller 4 in the tilt axis direction is zero, and the position of the spool 13 is neutral with respect to the sleeve 11. The shift ends when is reached.

Conventionally, there is a linear pulse motor disclosed in Japanese Patent Application Laid-Open No. 63-11058 which increases the resolution. The linear pulse motor increases the operating resolution of the scale by mounting the fine movement mechanism in two stages on the scale. In addition, Japanese Unexamined Patent Publication
In the hydraulic control device for an automatic transmission disclosed in Japanese Patent Laid-Open No. 21063, while the clutch mechanism is operating, the pressure reducing means reduces the hydraulic pressure to a low set value, and the duty is controlled to adjust the clutch pressure. After the operation is completed, the hydraulic shock is reduced to reduce the shift shock.
Furthermore, the variable displacement pump / motor displacement control device disclosed in Japanese Utility Model Laid-Open No. 2-131091 enables high-speed control and high resolution of the variable displacement pump at the same time.

[0010]

However, in the toroidal type continuously variable transmission described above, the resolution of the gear ratio depends on the resolution of the signal output to the solenoid valve 21, but the device that outputs this signal, that is, the solenoid. The valve drive circuit is
A PWM (pulse width modulation) control circuit is generally used because of its high reliability and low cost. However, the resolution of a general PWM control circuit is 1/1
Since it is about 00, the resolution of the gear ratio is limited to 1/100 or less, and the finer gear shift control cannot be performed. Further, a PWM control circuit having higher resolution is also known, but the PWM control circuit becomes expensive and the PW
The advantages of M control are diminished.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to change the sleeve position of the sleeve for controlling the gear ratio by supplying hydraulic pressure to the sleeve. Resolution higher than that of the electromagnetic solenoid that controls the solenoid valve, eg 1/25
6, etc., and the output signal to the electromagnetic solenoid is corrected according to the deviation between the detection value by the sleeve position sensor and the target value, and the low resolution, for example, about 1/100 An object of the present invention is to provide a toroidal type continuously variable transmission that can control a gear ratio with high resolution by using an electromagnetic solenoid.

According to the present invention, a solenoid valve actuated by an electromagnetic solenoid for supplying hydraulic pressure to a sleeve for setting a gear ratio provided in a control valve in a hydraulic circuit for gear shift control, the resolution of which is higher than the resolution of the electromagnetic solenoid is provided. A sleeve position sensor that detects the position of the sleeve, and a controller that controls the hydraulic pressure that sets the position of the sleeve to control the gear ratio that corresponds to the driving situation are provided, and the controller is set according to the target gear ratio. A toroidal control for correcting the duty control value of the electromagnetic solenoid and outputting the corrected duty control value based on the difference between the target sleeve position of the sleeve and the actual sleeve position of the sleeve detected by the sleeve position sensor. Type continuously variable transmission.

Further, this toroidal type continuously variable transmission continuously changes the rotation of the input disk in accordance with the change of the tilt angle with respect to the input disk and the output disk and the both disks which are arranged to face each other. It has a power roller that transmits to the output disk, a trunnion that rotatably supports the power roller and that can be displaced in the tilt axis direction, and a hydraulic cylinder that displaces the trunnion in the tilt axis direction.

Further, in this toroidal type continuously variable transmission, the shift control hydraulic circuit supplies the hydraulic pressure controlled by the control valve to the hydraulic cylinder to control the gear ratio, and the position of the sleeve. The hydraulic oil for displacing is supplied to the sleeve by driving the solenoid valve operated by the electromagnetic solenoid.

In the toroidal type continuously variable transmission according to the present invention, as described above, the solenoid valve for controlling the hydraulic pressure to the sleeve for determining the gear ratio is controlled by using the electromagnetic solenoid of low resolution. Depending on the sleeve position, the output signal to the electromagnetic solenoid is corrected in response to the deviation between the detected value of the sleeve and the target value, and the effect of ensuring fine shift control equivalent to that using an electromagnetic solenoid of high resolution can be achieved. Further, in this toroidal type continuously variable transmission, since the solenoid valve for controlling the supply of hydraulic oil is corrected as described above, an inexpensive electromagnetic solenoid control device having a resolution of about 1/100 is used to operate an electromagnetic solenoid having a high resolution. The gear ratio can be controlled as used.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a toroidal type continuously variable transmission according to the present invention will be described below with reference to FIGS. FIG. 1 is a schematic explanatory view showing an embodiment of the toroidal type continuously variable transmission according to the present invention, and FIG. 2 is a process flow chart showing an embodiment of the toroidal type continuously variable transmission of FIG. The toroidal-type continuously variable transmission shown in FIG. 1 has the same configuration as that of the toroidal-type continuously variable transmission shown in FIG. 3 except that a sleeve position sensor is provided. Is attached.

In the toroidal type continuously variable transmission according to this embodiment, the input disk 2 and the output disk 3, which are arranged opposite to each other, rotate the input disk 2 in accordance with the change of the tilt angle with respect to both disks 2 and 3. A power roller 4 that continuously changes the speed and transmits to the output disk 3, a trunnion 6 that rotatably supports the power roller 4 and is displaceable in the tilt axis direction, and a hydraulic cylinder 8 that displaces the trunnion 6 in the tilt axis direction.
(8a, 8b), control valve 10 for controlling the hydraulic pressure to hydraulic cylinder 8, hydraulic oil for displacing control valve 10
A solenoid valve 21 which is operated by an electromagnetic solenoid 19 for supplying to the solenoid, and a sleeve 11 which controls a hydraulic pressure for controlling a gear ratio. In particular, the sleeve 11 has a resolution higher than that of the electromagnetic solenoid 19.
The sleeve position sensor 22 for detecting the position of the sleeve 11 is provided, and the target sleeve position of the sleeve 11 is set according to the target gear ratio.
Detecting the actual sleeve position of the
The ty control value is corrected by the difference between the target sleeve position and the actual sleeve position, and the corrected duty control value is output.

In this embodiment, the sleeve position sensor 2
Reference numeral 2 is a potentiometer configured to contact the end surface of the sleeve 11 and detect the position of the sleeve 11. The sleeve position sensor 22 detects the position of the sleeve 11, feeds back the detected value to the controller 20, controls the controller 20 with the resolution, and turns on / off the electromagnetic solenoid 19 to maintain the position of the sleeve 11. There is. The resolution of the drive circuit of the electromagnetic solenoid 19 is inferior to that of the sleeve position sensor 22. However, if the resolution of the electromagnetic solenoid 19 is increased, it becomes expensive, and the resolution is generally 1/100.
It can be used at a low cost. On the other hand, the resolution of the sleeve position sensor 22 is generally 8 bits or more, and the resolution is about 1/250.
Therefore, if the opening / closing of the solenoid valve 21 by the electromagnetic solenoid 19 is fed back to the controller 20 by the detection signal of the position of the sleeve 11 of the sleeve position sensor 22 to control the solenoid valve 21, it is as if the resolution of the electromagnetic solenoid 19 is enhanced. It is possible to control with, and it is possible to achieve fine control with high precision.

The operation of this toroidal type continuously variable transmission will be described with reference to FIG. In the toroidal type continuously variable transmission of this embodiment, the detection signal of the position of the sleeve 11 of the sleeve position sensor 22 is input to the controller 20. In the main control routine, the target gear ratio e0 is determined by the vehicle speed, accelerator opening, engine speed, etc. (step 1). The controller 20 determines the target gear ratio e
The target sleeve position V0 is determined according to 0 (step 2). The sleeve position sensor 22 allows the sleeve 11
Is detected, that is, the actual sleeve position V is detected (step 3). The controller 20 includes a sleeve position sensor 22.
The duty correction amount of the output signal to the electromagnetic solenoid 19 for driving the solenoid valve 21 is determined by the deviation between the actual sleeve position V and the target sleeve position V0 according to the signal from (step 4). Therefore, the duty output signal to the electromagnetic solenoid 19 determined according to the target gear ratio e0 is added with the duty correction amount depending on the sleeve position, and the corrected duty output signal is output to the electromagnetic solenoid 19,
The solenoid valve 21 is opened and closed to control the position of the sleeve 11 that determines the gear ratio (step 5).

For example, in this toroidal type continuously variable transmission, an electromagnetic solenoid 19 that drives a solenoid valve 21.
Is 1/100, the resolution of the sleeve position sensor 22 is 1/200, and the signal of the sleeve position sensor 22 corresponding to the duty ratio 50%, 51% of the output signal to the electromagnetic solenoid 19 of the solenoid valve 21 is 100/200. ,
102/200, and the target gear ratio e0 at this time is converted into a signal of the sleeve position sensor 22 by 101/200.
In this case, the sleeve 11 reciprocates between 100/200 and 102/200 in terms of the signal of the sleeve position sensor 22, but it is sufficiently faster than the responsiveness of the toroidal transmission unit 1, and as a result, 100 / 200 and 102/200
The toroidal transmission unit 1 is controlled to a transmission ratio corresponding to the average value of 101/200. Therefore, the gear ratio of the toroidal transmission unit of the toroidal type continuously variable transmission can be finely controlled with high accuracy.

[0021]

As described above, the toroidal type continuously variable transmission according to the present invention includes the sleeve position sensor for detecting the position of the sleeve for determining the gear ratio having a resolution higher than that of the electromagnetic solenoid for driving the solenoid valve. Since the duty output signal to the electromagnetic solenoid is corrected according to the difference between the target sleeve position and the actual sleeve position according to the target gear ratio and the corrected duty control value is output, the resolution is 1/100. A low-priced electromagnetic solenoid can drive the solenoid valve with a higher resolution, can control the gear ratio with high accuracy and finely, and can reduce the cost of the toroidal-type continuously variable transmission. Moreover, since the position signal based on the sleeve position is fed back and corrected, even if a disturbance such as a change in oil temperature occurs, the gear ratio can be immediately controlled.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an embodiment of a toroidal type continuously variable transmission according to the present invention.

FIG. 2 is a process flow chart showing an embodiment of the operation of the toroidal type continuously variable transmission according to the present invention.

FIG. 3 is a schematic explanatory view showing a conventional toroidal type continuously variable transmission.

FIG. 4 is a process flow chart showing an operation of a conventional toroidal type continuously variable transmission.

[Explanation of symbols]

 1 Toroidal Transmission 2 Input Disc 3 Output Disc 4 Power Roller 5 Tilt Shaft 6 Trunnion 8 Hydraulic Cylinder 10 Control Valve 11 Sleeve 19 Electromagnetic Solenoid 20 Controller 21 Solenoid Valve 22 Sleeve Position Sensor

Claims (3)

[Claims] 1. A solenoid valve operated by an electromagnetic solenoid for supplying hydraulic pressure to a sleeve for setting a gear ratio provided in a control valve in a hydraulic circuit for gear shift control, and a sleeve valve having a resolution higher than that of the electromagnetic solenoid. A sleeve position sensor for detecting a position, and a controller for controlling a hydraulic pressure for setting the position of the sleeve for controlling to a gear ratio corresponding to an operating condition are provided, and the controller has the sleeve set according to a target gear ratio. The duty control value of the electromagnetic solenoid is corrected by the difference between the target sleeve position of the above and the actual sleeve position of the sleeve detected by the sleeve position sensor,
A toroidal type continuously variable transmission that performs control to output a corrected duty control value. 2. An input disc and an output disc, which are arranged to face each other, and a power roller for transmitting the rotation of the input disc to the output disc by steplessly changing the rotation of the input disc in accordance with a change of a tilt angle with respect to the both discs. The toroidal type continuously variable transmission according to claim 1, further comprising: a trunnion that rotatably supports the power roller and is displaceable in a tilt axis direction, and a hydraulic cylinder that displaces the trunnion in a tilt axis direction. 3. The shift control hydraulic circuit supplies a hydraulic pressure controlled by the control valve to the hydraulic cylinder to control a gear ratio, and hydraulic oil for displacing the position of the sleeve to the electromagnetic solenoid. 3. The toroidal type continuously variable transmission according to claim 1, wherein the toroidal type continuously variable transmission is configured by a circuit that supplies the sleeve by driving the solenoid valve that is operated by.