JPH0351938B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control method for a continuously variable transmission.

In the gear change control of a continuously variable transmission installed in a vehicle, the actual gear ratio is generally detected, the difference between this and the target gear ratio is calculated, and the gear change actuator (for example, A rotary motor for speed change control) is controlled.

In conventional shift control methods, when a signal instructing a rapid shift is given to a shift actuator,
The transmission actuator was adapted to operate at a very high speed, regardless of the actual transmission ratio change of the continuously variable transmission. However, in the case of a continuously variable transmission in which the hydraulic pressure in the pulley cylinder chamber of the V-belt continuously variable transmission mechanism is controlled by a speed change valve operated by a speed change actuator, the speed change actuator is operated as described above. Operating at high speeds causes the following problems. In other words, the speed at which the speed change valve moves is faster than the actual speed change of the continuously variable transmission mechanism, and the oil pressure in one of the pulley cylinder chambers temporarily decreases, causing the tension applied to the V-belt to disappear, causing the V-belt to This caused problems such as damage to the V-belt and decreased durability.

The present invention has been made by focusing on the above-mentioned problems in the conventional continuously variable transmission control method, and the maximum movement speed of the speed change valve, that is, the maximum rotation speed of the speed change control rotary motor, is The signal that commands the rotation speed of the rotary motor for speed change control is based on the target speed ratio (or target engine speed) and the actual speed ratio (or actual engine speed). The purpose of the present invention is to improve the substantial speed change response by making the difference proportional to the sum of the deviation and the differential value of the deviation, thereby solving the above-mentioned problems.

Hereinafter, the present invention will be explained based on FIGS. 1 and 2 of the accompanying drawings.

FIG. 1 shows a block diagram of a configuration for implementing the method of the present invention. Target gear ratio calculation device 100
Various signals 10 (for example, a vehicle speed signal, an engine rotational speed signal, a throttle opening signal, etc.) indicating the driving state of the vehicle are inputted to the input signal 10, and a target gear ratio signal 11 is calculated according to a predetermined calculation method. This target gear ratio signal 11 is input to a gear ratio deviation calculation device 110. The actual speed ratio signal 21 calculated by the actual speed ratio calculation device 220 is also input to the speed ratio deviation calculation device 110 . The gear ratio deviation calculation device 110 calculates a deviation E ₀ between the target gear ratio signal 11 and the actual gear ratio signal 21. A signal 12 indicating the deviation E ₀ is input to a multiplier 120 and a differentiator 130 . In the multiplier 120, the deviation E ₀ is multiplied by the first constant K ₁ . The differentiator 130 calculates a differential value dE ₀ /dt of the deviation E ₀ . Next, multiplication section 1
At step 40, the differential value dE ₀ /dt is multiplied by the second constant K ₂ . The value K ₁ ·E ₀ from the multiplier 120 and the value K ₂ ·dE ₀ /dt from the multiplier 140 are added in the adder 150, and the added value K ₁ ·E ₀ +K ₂ ·dE ₀ /dt is is sent to comparator 160. The comparison unit 160 compares the above-mentioned added value with a predetermined value (rotating motor rotational speed upper limit value C), and if the added value is larger, the rotating motor rotational speed from the motor rotational speed upper limit value setter 190 is Upper limit value C is changed by speed command device 1
Send to 80. On the other hand, if the added value is smaller than the predetermined value, the added value is transferred to the shift speed command device 180.
send to The shift speed command device 180 includes a comparison unit 16
Rotary motor 2 for speed change control based on the signal from 0
Command a rotation speed of 00. As a result, the speed change speed of the continuously variable transmission 210 is controlled.

FIG. 2 is a flowchart showing the functions from the gear ratio deviation calculation device 110 to the gear change speed command device 180, which is constructed by a microcomputer. First, calculate the difference between the target gear ratio and the actual gear ratio, and set this as the deviation E ₀₅₆
1. Next, the deviation E ₀ is multiplied by the first constant K ₁ to obtain 56
2. Next, the difference between the deviation E ₀ and the deviation E _-1 from the previous calculation is multiplied by a second constant K ₂ 563. Then,
564. Add K ₁ · E ₀ and K ₂ · (E ₀ -E _-1 ) and use this as a shift speed signal. Next, it is determined 565 whether the above-mentioned added value is equal to or greater than a predetermined rotary motor rotation speed upper limit value C. If the above-mentioned added value exceeds the rotary motor rotational speed upper limit value C, the rotary motor rotational speed upper limit value C is set as the speed change signal 566. If the added value is less than or equal to the rotary motor rotational speed upper limit value, the added value is directly used as the speed change signal. Next, E ₀ is replaced with E _-1 for the next calculation 567. Note that the rotary motor rotation speed upper limit value C given by the motor rotation speed upper limit value setter 190 allows the V-belt to follow the speed change operation without slipping when the speed change control rotary motor is controlled based on this value. It is set to the limit value that can be used. Therefore, since the speed change control rotary motor does not rotate at a rotation speed higher than the rotary motor rotation speed upper limit value C, the speed change valve moves too fast and the oil pressure in the pulley cylinder chamber temporarily decreases.
No belt slippage occurs.

In the end, the following operation is obtained by the above-mentioned control. From a steady driving state where the target gear ratio matches the actual gear ratio,
For example, if a deviation occurs between the target gear ratio and the actual gear ratio due to depressing the accelerator pedal, the rotation motor for gear change control will produce K ₁ · E ₀ + K ₂ ·
It is driven at a rotational speed proportional to dE ₀ /dt for a period of time until the deviation becomes 0. If the value of the deviation E ₀ is large or (and) the differential value of E ₀ is large,
The speed change control rotary motor rotates at a rotational speed that is a rotational motor rotational speed upper limit value. The rotational displacement of the speed change control rotary motor is transmitted to the speed change valve via a link mechanism or the like. By doing this, the oil pressure in the pulley cylinder chamber of the continuously variable transmission is controlled, and the gear ratio of the continuously variable transmission is changed. As mentioned above, since the maximum rotational speed of the speed change control rotary motor is limited to the upper limit value of the rotary motor rotational speed, slippage of the V-belt does not occur. Although the maximum rotational speed of the rotational motor for speed change control is limited to the rotational motor rotational speed upper limit value, since a differential term is added to the signal that commands the rotational speed, good speed change responsiveness can be obtained. Note that since the speed change control rotary motor is driven for a period of time until the deviation becomes 0, a large steady deviation from the target value does not occur (that is, the speed ratio does not settle to the target value).

In the above embodiment, control is performed based on the deviation between the target gear ratio and the actual gear ratio, but when the vehicle speed is constant, the gear ratio and engine rotational speed have a predetermined relationship, so the target gear ratio is It is clear that the same control as above can be performed based on the deviation between the engine rotation speed and the actual engine rotation speed.

As explained above, according to the present invention, the target gear ratio (or target engine speed) of the continuously variable transmission is determined according to the driving condition of the vehicle, and the actual gear ratio (or actual speed ratio) of the continuously variable transmission is determined. detects the engine rotation speed) and controls the rotary motor for gear change control of the continuously variable transmission based on the target gear ratio (or target engine rotation speed) and the actual gear ratio (or actual engine rotation speed). In a control method for a continuously variable transmission that controls the gear ratio by Multiply by a first constant, calculate the differential value of the deviation, multiply the differential value by a second constant,
A value obtained by multiplying the deviation by a first constant and a value obtained by multiplying the differential value by a second constant are added, and a signal is generated to command the rotational speed of the rotary motor for speed change control according to the added value. At the same time, the signal that commands this rotational speed is restricted from exceeding the limit value that prevents the V-belt from slipping, so the rotating motor for speed change control is rotated at the fastest speed within the range where the V-belt will not slip. In addition, good shift response can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a configuration for implementing the method of the present invention, and FIG. 2 is a diagram showing a flowchart of calculations according to the method of the present invention. DESCRIPTION OF SYMBOLS 100... Target gear ratio calculation device, 110... Gear ratio deviation calculation device, 120... Multiplication part, 130... Differentiation part, 140... Multiplication part, 150... Addition part, 160...
Comparison unit, 180... Shift speed command device, 190... Motor rotation speed rotating motor rotation speed upper limit value setter,
200...Rotating motor, 210...Continuously variable transmission, 22
0...Actual gear ratio calculation device.

Claims (1)

[Scope of Claims] 1. Determining the target gear ratio or target engine rotation speed of the continuously variable transmission according to the driving state of the vehicle, and detecting the actual gear ratio or the actual engine rotation speed of the continuously variable transmission, Control of a continuously variable transmission that controls a gear ratio by controlling a rotary motor for gear change control of the continuously variable transmission based on a target gear ratio or target engine rotation speed and an actual gear ratio or actual engine rotation speed In the method, a deviation between a target gear ratio or a target engine rotational speed and an actual gear ratio or an actual engine rotational speed is calculated, the deviation is multiplied by a first constant, and a differential value of the deviation is calculated, Multiply the differential value by a second constant, add the value obtained by multiplying the deviation by the first constant, and the value obtained by multiplying the differential value by the second constant, and adjust the speed change control rotation according to this added value. A control method for a continuously variable transmission, comprising: generating a signal for commanding the rotational speed of a motor; and restricting the signal for commanding the rotational speed from exceeding a limit value at which a V-belt will not slip. 2. The continuously variable transmission according to claim 1, wherein the rotation amount of the speed change control rotary motor is determined based on the rotation speed of the speed change control rotary motor and the driving time until the deviation becomes zero. control method.