JPH09292014A - Continuously variable transmission - Google Patents

Abstract

[PROBLEMS] To provide a continuously variable transmission that eliminates delay in shifting time when the vehicle starts and does not slow down the speed at which hydraulic pressure in the input side chamber is released. Clutch 1 for transmitting driving force
2, input side chamber 11f, input side movable pulley 11
a, an input side pulley mechanism 11A having an input side fixed pulley 11b, an output side chamber 11g, an output side movable pulley 11
d, an output side pulley mechanism 11B having an output side fixed pulley 11e, and a transmission belt 11c for transmitting a driving force,
A continuously variable transmission 11 that shifts the driving force from the clutch 12 and transmits the driving force after shifting, and the movable pulleys 11a and 11a.
The oil pump 5 and the speed change control valve 2 capable of introducing and discharging the fluid into and from the chambers 11f and 11g to operate the respective d.
1. The solenoid valve 23 and the control device 6 for controlling these operations are provided, and the control device 6 introduces the fluid into the input side chamber 11f immediately after the engine is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for a continuously variable transmission of a vehicle.

[0002]

2. Description of the Related Art As a conventional continuously variable transmission, a primary pulley and a secondary pulley are connected by a belt, hydraulic pressure is applied to each pulley to move the pulleys in an axial direction, and a gear is changed according to a pressure difference applied to each pulley. It is generally known to do so. However, in the continuously variable transmission of this type, for example, when a vehicle having the continuously variable transmission stops traveling and the engine is turned off, the hydraulic pressure gradually escapes from a small gap or the like in the continuously variable transmission. Therefore, if the engine is off for a long time, the amount of hydraulic pressure released also increases, and there is a problem that the shift time is delayed when shifting the gear when the engine is started next time.

Therefore, as a technique for solving this problem,
SUBARU REX660 New model car manual ('90.
There is a continuously variable transmission described in 3). FIG. 3 shows a hydraulic circuit diagram of the continuously variable transmission described in the prior art. In this technique, a primary pulley 50 and a secondary pulley 60 are connected by a belt 70, hydraulic pressure is applied to the pulleys 50, 60 to move the pulleys 50 in the axial direction, and a gear shift is performed according to a pressure difference applied to the pulleys 50, 60. If the primary chamber 51 of the primary pulley 50 is in a low state and not filled with oil, a delay in the shift time occurs at the start of the shift, so the gear ratio shifts from the high side to the low side. At this time, and when it is completely on the low side, the shift control valve 80 has a structure for introducing the lubricating oil pressure of the oil passage 81 into the primary chamber 51 so that the delay of the shift time is eliminated at the start of the shift.

[0004]

Here, in the continuously variable transmission of the type in which the pulley and the belt are used for shifting as shown in the technique of FIG. 3, the continuously variable transmission is introduced into the primary pulley 50 and the secondary pulley 60. The gear ratio is set according to the difference between the hydraulic pressures to perform the gear shift control. However, since the continuously variable transmission of FIG. 3 introduces the lubricating pressure into the primary chamber 51, when introducing the hydraulic pressure required for gear shifting into the secondary chamber 61, in addition to the pressure difference required for gear shifting, It is necessary to introduce an extra hydraulic pressure to generate the same pressing force as the pulley pressing force generated by the lubricating pressure introduced into the chamber 51. As described above, according to the above-described technique, the pump efficiency of the oil pump 82 and the efficiency of the belt 70 between the pulleys, which are sufficient to introduce an extra hydraulic pressure into the secondary chamber 61, are reduced. It decreases by the increment. Further, when the continuously variable transmission shifts from the high side to the low side, the shift control valve 80 is switched to release the hydraulic pressure introduced into the primary chamber 51, but at the same time, the lubricating pressure is supplied from the oil passage 81. Since the structure is such that it is introduced into the primary chamber 51, the hydraulic pressure in the primary chamber 51 at the time of shifting from the high side to the low side escapes as compared with the conventional continuously variable transmission that does not introduce the lubricating pressure into the primary chamber. There is a problem that the speed becomes slower, and the shift from the high side to the low side becomes slower accordingly.

Therefore, it is a technical object of the present invention to provide a continuously variable transmission that eliminates the delay of the shift time when the vehicle starts and solves the above problems.

[0006]

In order to solve the above problems, a first aspect of the present invention is directed to a clutch for transmitting a driving force of an engine, an input side movable pulley which operates according to a fluid introduced into an input side chamber, and an input. Output side pulley mechanism having an input side pulley mechanism having an output side movable pulley and an output side fixed pulley that operates according to the fluid introduced into the output side chamber, and the driving force of the input side pulley mechanism is output. And a transmission belt for transmitting to the side pulley mechanism, introducing fluid into the input side chamber and the output side chamber to change the driving force output from the clutch, and to transmit the changed driving force to the driving wheels. And a fluid supply device capable of introducing and discharging fluid to and from the input side chamber and the output side chamber to operate the input side movable pulley and the output side movable pulley, respectively. In the continuously variable transmission and a control unit for controlling the operation, the control device immediately after the start of the engine, and a fluid supply device to introduce fluid into the input chamber to actuate.

According to the first aspect of the present invention, when the engine is stopped and the engine is started again, even if the hydraulic pressure of the primary pulley has been exhausted, when the control circuit detects the start of the engine, the shift control is performed. Since the hydraulic pressure is controlled so as to be introduced into the input side pulley mechanism, it is possible to eliminate the delay in the shift time when the vehicle starts.

Further, since the continuously variable transmission according to the present invention controls the operation of the fluid supply device so that the fluid is introduced immediately after the engine is started, when the fluid in the input side chamber is to be drained, as shown in FIG. The lubricating pressure is not introduced in the opposite direction to the fluid drain direction. Therefore, the pump efficiency of the oil pump and the belt efficiency between the pulleys do not decrease even if control is performed to eliminate the delay in the shift time when the vehicle starts. There is no delay in shifting.

According to a second aspect of the present invention, in the continuously variable transmission according to the first aspect, the control device introduces the fluid into the input side chamber after the engine is started and before the continuously variable transmission shifts. The fluid supply device was activated.

According to a third aspect of the present invention, in the continuously variable transmission according to the first aspect, the control device introduces fluid into the input side chamber during a period from when the engine is started to when the idling speed of the engine is reached. The fluid supply device was activated.

According to claims 2 and 3, claim 1
In addition, the input side chamber can be filled with the fluid immediately after the engine is started, and it is possible to reliably eliminate the delay in the shift time when the vehicle starts.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a shift control device according to the present embodiment. In FIG. 1, a continuously variable transmission 1 including a transmission 11 and a clutch 12 is arranged between an engine (not shown) and wheels (not shown). As shown in FIG. 1, the transmission 11 of the continuously variable transmission 1 increases or decreases the rotation speed on the engine side and transmits the rotation speed to the wheel side, is connected to the engine side, and is connected to the input side chamber 11f. An input side pulley mechanism 11A having an input side movable pulley 11a and an input side fixed pulley 11d whose effective diameter is variable according to the introduced fluid, is connected to the wheel side, and is connected to the output side chamber 11
It is wound around an output side pulley mechanism 11B having an output side movable pulley 11b and an output side fixed pulley 11e whose effective diameter is variable according to the fluid introduced into g, and an input side pulley mechanism 11A and an output side pulley mechanism 11B. Transmission belt 11
c. The clutch 12 disconnects or connects the transmission from the engine to the wheels on the engine side of the transmission 11, and is composed of a vehicle forward clutch 12a and a vehicle reverse clutch 12b. The driving force introduced and output from the clutch 12 is changed in speed, and the changed driving force is transmitted to the driving wheels.

In the present embodiment, the fluid supply device is composed of the oil pump 5, the shift control valve 21, and the solenoid valve 23, and these operations cause the fluid to be introduced into or discharged from the input side chamber 11f, thereby inputting the fluid. The side movable pulley 11a is operated. The operation of these fluid supply devices is performed by the control circuit 6 as a control device. The shift control valve 21 and the solenoid valve 23
The operation of will be described later.

The operation of the continuously variable transmission 1 will be described. The operation of the transmission 11 is controlled by the speed change control unit 2 including the speed change control valve 21 and the regulator valve 22 that are connected to the oil pump 5, and is connected to the oil pump 5 through the reduction valve 4 to be described later. The operation of the clutch 12 is controlled by the clutch control unit 3 including the control valve 31 and the like.

The regulator valve 22 is operated by a solenoid valve 24 which is duty-controlled by a control circuit 6 which is a microcomputer for performing overall control in the present embodiment, and the hydraulic pressure from the oil pump 5 is supplied to the solenoid valve 24. The line pressure PL of the shift control unit 2 is determined by adjusting the pressure based on the solenoid pressure P2. The hydraulic circuit is configured so that the output side movable pulley 11b is moved by the line pressure PL.

The shift control valve 21 is operated by a solenoid valve 23 whose duty is controlled by the control circuit 6, and regulates the pressure based on the solenoid pressure P1 of the solenoid valve 23 to determine the control pressure PI of the input side movable pulley 11a. The hydraulic circuit is configured to do so. The solenoid valve 23 is a normally open valve that does not generate the solenoid pressure P1 in the non-energized state, and the shift control valve 21 generates a minimum control pressure PI when the current flowing through the solenoid valve 23 is a predetermined current value or less. Become. Further, the solenoid valve 24 is a normally closed valve that generates the maximum solenoid pressure P2 in the non-energized state, and the regulator valve 22 generates the maximum line pressure PL when the current flowing through the solenoid valve 24 is a predetermined current value or less. Become. Therefore, in the transmission 11, the effective diameter of the input side movable pulley 11a is the minimum, and the effective diameter of the output side movable pulley 11b is the minimum stage at the currents below the predetermined current values of the solenoid valve 23 and the solenoid valve 24. There is.

The reduction valve 4 regulates the line pressure PL of the shift control unit 2 to control the clutch control valve 31,
A constant pressure is introduced to the solenoid valve 23, the solenoid valve 24, and the solenoid valve 32. The clutch control valve 31 of the clutch control unit 3 is operated by a solenoid valve 32 whose duty is controlled by the control circuit 6, and determines the control pressure PE of the clutch control unit 3. Switching valve 7
When the solenoid valve 32 is not defective, the control pressure PE is introduced into the switching valve 7 and the control pressure PC ′ is changed to the shift valve 8
When the solenoid valve 32 fails, the control valve PC is operated to introduce the control pressure PC into the switching valve 7 to supply the control pressure PE ′ from the switching valve 7 to the shift valve 8. This control pressure P
C'or control pressure PE 'is set to the clutch hydraulic pressure PFC or the clutch hydraulic pressure PRC, and the clutch hydraulic pressure PFC or the clutch hydraulic pressure PRC connects the forward clutch 12a or the reverse clutch 12b to the hydraulic system via the shift valve 8. There is.

The control circuit 6 controls the duty ratios of the solenoid valve 23, the solenoid valve 24, and the solenoid valve 32, and receives the output from the shift position signal generating means 10 for detecting the position of the shift lever 9. .
Further, the rotation speed of the shaft of the input side pulley mechanism 11A is detected by the input side rotation detector 13, and the output side pulley mechanism 11B is also detected.
The rotation speed of the shaft is detected by the input side rotation detector 14 and the outputs thereof are input to determine the current gear ratio. Furthermore,
The operation signal of the idle switch is being input.

Next, a flow chart of the control circuit 6 in the present embodiment is shown in FIG. When the ignition switch is turned on in step 101, control is started. In step 102, the program is initialized so that the speed change control valve 21 moves from the oil pump to the input side chamber 11
The state in which the oil passage to f is opened is flag 1 = 0. Next, the routine proceeds to step 103, where it is determined whether or not flag 1 = 1, and if flag 1 = 0, then the routine proceeds to step 104. Step 1
In 04, it is determined whether the engine speed is equal to or higher than the set speed Ne0 (in the present embodiment, the set speed Ne0 is an idling speed), and the engine speed is Ne.
When it is smaller than 0, the process proceeds to step 105. In step 105, the duty ratio of the solenoid valve 23 is set to the maximum (1
00%), the hydraulic pressure is introduced into the input side chamber 11f at once. As a result, the hydraulic pressure in the input-side chamber 11f that has escaped between the previous run and the current run is filled. The introduction of hydraulic pressure into the input side chamber 11f is as shown in FIG.
As shown in the flow chart of No. 1, the process is performed until the engine speed reaches the set speed Ne0. Then, when the engine speed reaches the set speed Ne0, the shift control that has been conventionally performed conventionally (detailed description thereof is omitted because it is not the purpose of the present invention). Then, when the ignition switch is turned off, the control of FIG. 3 ends. The flag 1 set in step 102 in the present embodiment
Once the flag 1 is established (flag 1 = 1), the flag 1 is maintained until the next initialization.

By only adding the above control to the conventional shift control, it is possible to eliminate the delay of the shift time at the start of the shift, and the inside of the input side chamber 11f at the time of shifting the gear ratio from the high side to the low side. When draining the fluid
Since the hydraulic pressure is not supplied in the direction opposite to the drain direction of the fluid, it is not necessary to improve the pump efficiency of the oil pump and the efficiency of the belt between the pulleys, and moreover from the high side to the low side of the continuously variable transmission. There is no delay in shifting.

In the above embodiment, the control circuit is adapted to introduce the hydraulic pressure into the input side chamber from the time when the ignition switch is turned on until the engine speed reaches the idling speed, but the idling speed is not detected. Instead, the time from when the engine speed reaches the idling speed immediately after the engine starts is set in advance, and the above-mentioned flag 1 = 0 is set by the timer to maximize the duty ratio of the solenoid valve 23. Such control may be used.

[0023]

According to the first aspect of the present invention, when the engine is stopped and then restarted, even if the hydraulic pressure of the primary pulley has been exhausted, the control circuit detects the start of the engine before performing the shift control. Since the hydraulic pressure is controlled so as to be introduced into the input side pulley mechanism, it is possible to eliminate the delay in the shift time when the vehicle starts.

Further, since the operation of the fluid supply device is controlled so that the fluid is introduced immediately after the engine is started, when the fluid in the input side chamber is drained, the drain direction of the fluid is changed as in the technique of FIG. On the contrary, no lubricating pressure is introduced. Therefore, even if the control is performed so as to eliminate the delay in the shift time when the vehicle starts, the pump efficiency of the oil pump,
The efficiency of the belt between the pulleys does not decrease, and the shifting of the continuously variable transmission from the high side to the low side does not slow down.

According to claim 2 and claim 3, claim 1
In addition, the input side chamber can be filled with the fluid immediately after the engine is started, and it is possible to reliably eliminate the delay in the shift time when the vehicle starts.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart of a control circuit according to the present embodiment.

FIG. 3 is a hydraulic circuit diagram of a conventional continuously variable transmission.

[Explanation of symbols]

1 ... continuously variable transmission 2 ...
・ Shift control unit 6 ・ ・ ・ Control circuit 11 ・
..Transmission 11a ... Input side movable pulley 11b
... Input side fixed pulley 11c ... Conduction belt 11d
... Output side movable pulley 11e ... Output side fixed pulley 11f
... Input side chamber 11g ... Output side chamber 11A
・ ・ ・ Input side pulley mechanism 11B ・ ・ ・ Output side pulley mechanism 12 ・
..Clutch 23, 24, 32 ... Solenoid valve

Claims (3)

[Claims] 1. An input side pulley mechanism having a clutch for transmitting a driving force of an engine, an input side movable pulley and an input side fixed pulley which operate according to a fluid introduced into the input side chamber, and an input side pulley mechanism. An output side pulley mechanism having an output side movable pulley and an output side fixed pulley that operate according to the fluid to be discharged, and a transmission belt that transmits the driving force of the input side pulley mechanism to the output side pulley mechanism, A continuously variable transmission that introduces fluid into the input side chamber and the output side chamber to change the driving force output from the clutch and transmits the changed driving force to the driving wheels, the input side movable pulley and the Output side pulley A fluid supply device capable of introducing and discharging a fluid to and from the input side chamber and the output side chamber to operate the movable pulley, and the operation of the fluid supply device is controlled. And a control device for controlling the fluid supply device, wherein the control device operates the fluid supply device so as to introduce the fluid into the input side chamber immediately after the engine is started. Continuously variable transmission. 2. The control device operates the fluid supply device so as to introduce a fluid into the input side chamber between the start of the engine and the speed change of the continuously variable transmission. The continuously variable transmission according to claim 1. 3. The control device operates the fluid supply device so as to introduce a fluid into the input side chamber during a period from when the engine is started to when an idling speed of the engine is reached. The continuously variable transmission according to claim 1, which is characterized in that.