JPH07109233B2 - Pressure valve drive control method for continuously variable transmission for vehicle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure valve drive control method for a continuously variable transmission for a vehicle, and particularly when the vehicle travels at low speeds, the drive frequency of the pressure control valve means is higher than that at high speeds. In addition to the changeover to the clutch pressure change control, the durability of the pressure control valve means at the time of high speed traveling is improved and the vehicle body vibration caused by the pressure fluctuation at the time of low speed traveling is improved. TECHNICAL FIELD The present invention relates to a pressure valve drive control method for a continuously variable transmission for a vehicle that is prevented.

[Conventional technology]

In a vehicle, a transmission is interposed between an internal combustion engine and driving wheels. This transmission changes the driving force of the driving wheels and the traveling speed in accordance with the traveling condition of the vehicle that changes over a wide range, and thus the performance of the internal combustion engine is fully exhibited. In the transmission, for example, a fixed pulley part fixed to the rotary shaft and a movable pulley part mounted on the rotary shaft so as to be able to come into contact with and separate from the fixed pulley part are formed between both pulley part of the pulley. There is a continuously variable transmission that changes the gear ratio (belt ratio) by increasing and decreasing the radius of rotation of a belt wound around a pulley by hydraulically reducing the width of the belt to transmit power. This continuously variable transmission is disclosed, for example, in JP-A-57-186656, JP-A-59-43249, JP-A-59-77159 and JP-A-61-233256.

[Problems to be solved by the invention]

By the way, the drive control of the continuously variable transmission that changes the transmission using the above hydraulic pressure is performed by the line pressure of the hydraulic circuit (line), and the primary pressure (ratio) acting on the movable pulley piece to actually change the gear ratio. And, the clutch pressure (clutch) acting on the hydraulic clutch is divided into neutral mode, hold mode, normal start mode, special start mode and drive mode control mode as shown in Table 1, and the open loop, closed loop and output values are It is controlled with a constant duty ratio. And the frequency of this duty output value,
In other words, the pressure control valve means consisting of a solenoid valve that controls the hydraulic pressure in the hydraulic circuit is controlled at a relatively high frequency of 100 Hz in order to control the control characteristics of the hydraulic clutch and the vibration when the hydraulic clutch is slid and engaged. Being driven.

However, in a low temperature state (for example, -10 ° C or less), the viscosity in the hydraulic circuit becomes large. Therefore, when the drive frequency of the pressure control valve means is 100 Hz, the shift control valve of the pressure control valve means is driven. It is not possible to obtain sufficient output pressure of the solenoid valve to control it.Therefore, even when trying to start the vehicle, the clutch pressure, etc. will not be in the proper state, and as a result, the hydraulic clutch will be disconnected and the vehicle will run smoothly. It caused the inconvenience of not being able to call.

Therefore, the applicant of the present invention switches the drive frequency of the pressure control valve means in order to change the oil pressure according to the oil temperature state of the hydraulic circuit, secures an appropriate oil pressure at a low temperature when the oil viscosity is large, and We have already applied for a hydraulic control method that maintains proper pressure and improves drivability.

However, when the pressure control valve means is driven at a drive frequency of 100 Hz, there is a disadvantage that the durability of the pressure control valve means is reduced.

In addition, the drive frequency is 50Hz during low speed running at room temperature and high temperature.
When the pressure control valve means is driven by switching to, the pressure fluctuation in the hydraulic circuit occurs, and this pressure fluctuation causes vibration of the vehicle body, which gives an occupant an uncomfortable feeling.

[Object of the Invention]

Therefore, the object of the present invention is to eliminate the above-mentioned inconveniences.
The drive frequency of the pressure control valve means for controlling the hydraulic pressure during low speed traveling is switched to a value higher than that during high speed traveling, and this switching control operation is performed at times other than the clutch pressure change control, so that the pressure control valve means during high speed traveling. It is an object of the present invention to realize a pressure valve drive control method for a continuously variable transmission for a vehicle, which can improve the durability of the vehicle and can prevent vehicle body vibration due to pressure fluctuation during low speed traveling.

[Means for solving problems]

To achieve this object, the present invention is characterized in that the groove width between the fixed pulley portion piece and the movable pulley portion piece mounted on the fixed pulley portion piece so as to be able to come into contact with and separate from each other is increased by hydraulic pressure to increase the groove width. In a continuously variable transmission for a vehicle that performs gear shift control so as to change the gear ratio by increasing or decreasing the radius of gyration of the belt wound around both pulleys, a vehicle control detection means that detects the vehicle speed by providing a pressure control valve means that controls the hydraulic pressure. Is provided, the drive frequency of the pressure control valve means is switched to a larger value when the vehicle is traveling at a low speed than when the vehicle is traveling at a high speed, and this switching control operation is performed at times other than the clutch pressure change control.

[Action]

According to the method of the present invention, when the vehicle is traveling at a low speed other than the clutch pressure changing control, the drive frequency of the pressure control valve means is controlled to be switched to be larger than that at the high speed traveling, and the durability of the pressure control valve means during the high speed traveling The vehicle vibration is prevented due to pressure fluctuations during low speed running.

〔Example〕

Hereinafter, a practical example of the present invention will be described in detail and specifically with reference to the drawings.

1 to 8 show an embodiment of the present invention.
In FIGS. 5 and 6, 2 is a continuously variable transmission, 4 is a belt, 6 is a drive side pulley, 8 is a drive side fixed pulley part, and 10
Is a driving side movable pulley section piece, 12 is a driven side pulley section, 14 is a driven side fixed pulley section piece, and 16 is a driven side movable pulley section piece. The drive side pulley 6 is, as shown in FIGS.
A drive-side fixed pulley portion piece 10 fixed to the rotation shaft 18 and a drive-side movable pulley portion piece 10 mounted on the rotation shaft 18 such that the rotation shaft 18 can move in the axial direction but cannot rotate. Also,
The driven pulley 12 has the same structure as the driving pulley 6 and includes a driven fixed pulley portion 14 and a driven movable pulley portion 16.

The driving side movable pulley section piece 10 and the driven side movable pulley section piece
First and second housings 20 and 22 are attached to 12 respectively, and first and second hydraulic chambers 24 and 26 are formed respectively. Inside the second hydraulic chamber 26 on the driven side, there is provided a pressing spring 28 for urging the driven side movable pulley section piece 16 toward the driven side fixed pulley section piece 14.

An oil pump 30 is provided at the end of the rotary shaft 18. This oil-on pump 30 puts oil into the oil pan 32
The oil is supplied to the first and second hydraulic chambers 24 and 26 through the oil filter 34 and the first and second oil passages 38 and 40 forming the hydraulic circuit 36. In the middle of the first oil passage 38, a primary pressure control valve 44, which is a shift control valve that constitutes the pressure control valve means 42 for controlling the primary pressure (ratio) which is the input shaft sheave pressure, is provided. Further, in the first oil passage 38 on the oil pump 30 side of the primary pressure control valve 44, the line pressure (generally 5 to 25
constant pressure control valve 48 for controlling the kg / cm ²⁾ to a constant pressure (4~5kg / cm ²⁾ is continuously provided. Furthermore, in the primary pressure control valve 44,
A first three-way solenoid valve 52 for primary pressure control is connected in series via a fourth oil passage 50.

Further, a line pressure control valve 54 having a relief valve function for controlling a line pressure (line) that is a pump pressure is connected in the middle of the second oil passage 40 via a fifth oil passage 56. The line pressure control valve 54 is provided with a second line pressure control second three-way solenoid valve 60 connected in series through a sixth oil passage 58.

Further, the line pressure control valve 54 has a second position
A clutch pressure control valve 62 for controlling the clutch pressure (clutch) is connected in the middle of the second oil passage 40 on the hydraulic chamber 26 side via a seventh oil passage 64. A third three-way clutch pressure controlling solenoid valve 68 is connected to the clutch pressure control valve 62 via an eighth oil passage 66.

Further, the primary pressure control valve 44, the first solenoid valve 52 for primary pressure control, the constant pressure control valve 48, the sixth oil passage 58,
The second three-way solenoid valve 60 for line pressure control and the clutch pressure control valve 62 are communicated with each other by a ninth oil passage 70.

The clutch pressure control valve 62 communicates with the hydraulic clutch 74 via the tenth oil passage 72, and also communicates with the pressure sensor 78 midway through the tenth oil passage 72 via the eleventh oil passage 76. The pressure sensor 78 can directly detect the hydraulic pressure when controlling the clutch pressure in various modes such as the hold and start modes, and has a function of instructing the detected hydraulic pressure to be the target clutch.

Further, since the clutch pressure becomes substantially equal to the line pressure in the drive mode, it also contributes to the line pressure control.

The hydraulic clutch 74 includes a piston 80 and an annular spring.
82, first pressure plate 84, friction plate 86,
It is composed of the second pressure plate 88 and the like.

Further, a control unit 90 for inputting various conditions such as a throttle opening of a carburetor (not shown) of the vehicle and engine rotation to change the duty ratio to perform shift control is provided, and the control unit 90 controls the primary pressure control first three-way electromagnetic The valve 52 and the constant pressure control valve 48, the line pressure control second three-way solenoid valve 60, and the clutch pressure control third three-way solenoid valve 68 are configured to control the opening / closing operation and also the pressure sensor 78. There is. Further, the various signals input to the control unit 90 and the functions of the input signals will be described in detail. The detection signal of the shift lever position ... Each range signal such as P, R, N, D, L Control of required line pressure (line), ratio (primary pressure), clutch (clutch pressure), detection signal of caplet throttle opening .... Engine torque is detected from the memory input in the program in advance, target ratio or target Determination of engine speed, detection signal of carburetor idle position …… Improvement of accuracy in correction and control of carburetor throttle opening sensor, accelerator pedal signal …… Detects driver's intention based on the accelerator pedal depression state, and when driving Determines the control direction when starting, brake signal ...... Detects whether the brake pedal is depressed or not, Determining a disconnection or the like control the direction of the pressure clutch 74, sportiness performance para-mode option signal ...... vehicle (or economy property)
It is used as an option to set the oil pressure signal, etc .... There is a signal according to the oil temperature condition of the hydraulic circuit.

The hydraulic pressure signal is output from, for example, an oil temperature sensor 92 installed in the oil pan 32.

Further, the control unit 90, for example, according to the starting state of the vehicle and the oil temperature state in the hydraulic circuit 36, for example, the first, second and third three-way solenoid valves 52, 60 of the pressure control valve 42, It has the function of switching the drive frequency of 68. That is, as shown in a separate table, the control unit 90 sets the range of the oil temperature according to the schedule 1 until the vehicle starts for the first time after the engine is started and the hydraulic clutch 74 is completely locked up after the ignition switch (not shown) is turned on. First, second, depending on the state
The drive frequencies of the third three-way solenoid valves 52, 60, 68 are switched, and when the vehicle is not started for the first time, the first, second, and third three-way solenoid valves 52 are set according to the oil temperature state in which the range is set according to Schedule 2. , 60, 68 for switching the drive frequency.

That is, when the temperature is low, the viscosity of the oil is large, and at the time of start-up, the initial friction is generated by the air existing in each valve and each passage, so that the clutch pressure decreases and the hydraulic clutch 74
Therefore, in this embodiment, the drive frequencies of the first, second and third three-way solenoid valves 52, 60, 68 are switched according to the oil temperature state, and the hydraulic clutch 74 is operated.
This is to obtain an appropriate hydraulic pressure without slipping.

Here, the relationship based on the experimental results of the duty ratio, the output pressure, and the drive frequency at the oil temperature of -25 ° C will be described with reference to FIG. That is, the output pressure characteristics with the drive frequency at an oil temperature of -25 ° C show that the open / close time per cycle is short when the drive frequency is high, the oil viscosity is large, and the output pressure rise / fall response is high. Time is getting longer.
If the dew rate is small, the output pressure will not rise and
Therefore, the pressure does not rise easily. On the other hand, when the duty ratio is large, the fall is delayed and the pressure cut becomes worse. Therefore, if the driving frequency is lowered, the opening / closing time per cycle becomes longer, and the influence of the pressure response delay is reduced, so that the output pressure can be controlled in the duty cycle.

An input shaft rotation detection gear 93 is provided outside the first housing 20, and an input shaft side second rotation detector 94 is provided in the vicinity of the outer peripheral portion of the input shaft rotation detection gear 93. An output shaft rotation detection gear 95 is provided outside the second housing 22, and a second rotation detector on the output shaft side is provided in the vicinity of the outer peripheral portion of the output shaft rotation detection gear 95.
96 will be provided. Then, the detection signals of the first rotation detector 9 and the second rotation detector 96 are output to the control unit 90 to grasp the engine speed and the belt ratio.

The hydraulic clutch 74 is provided with an output transmission gear 97, and a third output detecting gear 97 is provided near the outer periphery of the gear 97 to detect the rotation of the final output shaft.
A rotation detector 98 is provided. That is, this third rotation detector 98
Detects the rotation of the reduction gear and differential gear, the drive shaft, and the final output shaft directly connected to the tire, and can detect the vehicle speed. Further, the rotation of the front and rear of the hydraulic clutch 74 can be detected by the second rotation detector 96 and the third rotation detector 98, which contributes to the detection of the clutch slip amount.

Further, the control unit 90 is configured to detect vehicle speed, for example, the first to the first.
The vehicle speed detection signals from the third rotation detectors 94, 96, 98 are input, and the driving frequencies of the first, second, and third three-way electric shaft valves 52, 60, 68 of the pressure control valve means 42 are set at low speed traveling. It has a function of switching to a greater degree than during high-speed running and a function of performing this switching control operation at times other than clutch pressure change control. That is, the control unit 90 controls the drive frequency of the first, second, and third solenoid valves 52, 60, 68 from the basic frequency of 100 Hz to 50 Hz when the vehicle speed becomes, for example, 60 km / H or more. In addition, when the vehicle speed drops below 55km / H, the switching frequency is controlled to return to the basic frequency of 100Hz.

Further, the time other than the clutch pressure change control indicates the time of clutch lockup or the drive mode.

The primary pressure control valve 44, as shown in FIG.
It has a spool valve 104 that reciprocates in 102, and is configured so that the relationship between the primary side diameter D of this spool valve 104 and the clutch side diameter d is D> d. A first atmosphere opening 106, a first oil passage 38, a second oil passage 40, a second atmosphere opening 108, and a ninth oil passage 70 are provided in the main body 102 from the left side in FIG. A fourth oil passage 50 is provided in the. In addition, the first and second springs 110 and 112 are arranged in the main body 102 so that the spool valve 104 is biased from the left and right sides to a predetermined position, that is, in a state where the passages are not communicated as shown in FIG. Are provided respectively.

Since the first, second and third three-way solenoid valves 52, 60 and 68 have the same structure, only the schematic structure of the first three-way solenoid valve 52 will be described in detail here with reference to FIG. First three-way solenoid valve
Reference numeral 52 denotes a case 114, two electromagnetic coils 116 in the case 114, and a plunger 118 that moves between the electromagnetic coils 116.
And a steel sphere 120 at the tip of the plunger 118, and this sphere 12
The seat portion 122 surrounding 0, the input / output ports 124 and 126 and the atmosphere port 128 provided in the seat portion 122, and the spring 130 for urging the plunger 118 in the atmosphere release blocking direction.
Have and. That is, when the electromagnetic coil 116 is not energized, the plunger 1 is urged by the urging force of the spring 130.
18 is moved downward, the input port 124 is closed by the sphere 120 to connect the output port 126 and the atmospheric port 128, and at the time of energization, a magnetic field is generated in the electromagnetic coil 116 to resist the urging force of the spring 130 and the plunger. It is configured to move 118 upwards and block the atmospheric port 128 with the sphere 120 so that the input / output ports 124, 126 are in communication. Although the sphere 120 is normally in a free state when energized, the sphere 120 is pressed by the hydraulic pressure from the input port 124 so as to close the atmosphere port 128.

Next, the drive frequency switching control according to the oil temperature state in this embodiment will be described.

In the continuously variable transmission 2, as shown in FIG. 6, an oil pump 30 located on the rotary shaft 18 operates in response to the drive of the rotary shaft 18, and the oil is supplied from an oil pan 32 at the bottom of the transmission to an oil filter 34. Be absorbed through. The line pressure, which is the pump pressure, is controlled by the line pressure control valve 54.If the amount of leakage from the line pressure control valve 54, that is, the escape amount of the line pressure control valve 54 is large, the line pressure becomes low, and conversely. If it is small, the line pressure will be high.

The operation of the line pressure control valve 54 is performed by a dedicated second three-way solenoid valve 60.
The line pressure control valve 54 is operated following the operation of the second three-way solenoid valve 60. The second three-way solenoid valve 60 is controlled at a duty ratio of a predetermined frequency. To be done. That is, the duty ratio of 0% means that the second three-way solenoid valve 60 does not operate at all, the output side is connected to the atmosphere side, and the output hydraulic pressure becomes zero. Also, the duty 100
The percentage means that the second three-way solenoid valve 60 operates so that the output side is connected to the input side, and the maximum output hydraulic pressure is the same as the control pressure, and the output hydraulic pressure is varied according to the duty ratio. Therefore, the characteristic of the second three-way solenoid valve 60 makes it possible to operate the line pressure control valve 54 in an analog manner, and the duty factor of the second three-way solenoid valve 60 is arbitrarily changed to control the line pressure. be able to. The operation of the second three-way solenoid valve 60 is controlled by the controller 90.

The primary pressure for shift control is the primary pressure control valve 44
Similarly to the line pressure control valve 54, the operation of the primary pressure control valve 44 is controlled by the dedicated first three-way solenoid valve 52. This first three-way solenoid valve 52
Used to connect the primary pressure to the line pressure or the primary pressure to the atmosphere side. Conduct the line pressure to shift the belt ratio to the full overdrive side, or to the atmosphere side to shift to the full low side. It is what makes me.

The clutch pressure control valve 62 that controls the clutch is connected to the line pressure side when the maximum clutch pressure is required and to the atmosphere side when the minimum clutch pressure is set.
Like the line pressure control valve 54 and the primary pressure control valve 44, the operation of the clutch pressure control valve 62 is also controlled by the dedicated third three-way solenoid valve 68, and therefore the description thereof is omitted here. The clutch pressure varies within the range from the minimum atmospheric pressure (zero) to the maximum line pressure.

There are five patterns for controlling the clutch pressure.

This pattern is as follows: (1) Neutral mode ...... When the shift position is N or P and the clutch is completely disengaged, the clutch pressure is the minimum pressure (zero) (2), Hold mode ...... Shift position is D, L or R If you have no intention of traveling by releasing the throttle with or if you want to decelerate and reduce the engine torque while traveling, the clutch pressure is at a low level (3) where the clutch comes into contact, the start mode ...... Again after starting or disengaging the clutch. When attempting to connect the clutch, the clutch pressure can be prevented from rising and the vehicle can operate smoothly. An appropriate level (4) according to the engine generated torque (clutch input torque), special start mode. ), The shift lever is D → N when the vehicle speed is 8 km / h or more.
→ Repeated use with D, or (b) the state where the brake state is released at 8km / h <vehicle speed 15km / h during deceleration operation (5) Drive mode …… The drive state shifts to the complete running state and the clutch is complete. There are five high levels of clutch pressure that are sufficient to withstand the engine torque. (1) of this pattern is performed by a dedicated switching valve (not shown) that is interlocked with the shift operation, and the other (2), (3), (4), and (5) are the first, second, and The duty ratio control of the third three-way solenoid valves 52, 60, 68 is performed. Particularly in the state (5), the clutch pressure control valve 62 causes the seventh oil passage 64 and the
10 The oil pressure is communicated with the oil passage 72, and the maximum pressure is generated, and the clutch pressure becomes the same as the line pressure.

Further, the primary pressure control valve 44 and the line pressure control valve 54,
The clutch pressure control valve 62 is controlled by the output hydraulic pressures from the first, second and third three-way solenoid valves 52, 60 and 68, respectively. These first, second and third three-way solenoid valves 52, 60, 68
The control oil pressure for controlling the is a constant oil pressure adjusted by the constant pressure control valve 48. This control oil pressure is always lower than the line pressure, but is a stable and constant pressure.
The control oil pressure is also introduced into each control valve 44, 45, 54, 62 to stabilize these control valves 44, 54, 62.

Next, electronic control according to the oil temperature state of the continuously variable transmission 2 will be described.

The continuously variable transmission 2 is hydraulically controlled, and in response to a command from the control unit 90, an appropriate line pressure for belt holding and torque transmission, a primary pressure for changing a gear ratio, and a hydraulic clutch 74 are set. The respective clutch pressures for ensuring the engagement are secured.

Next, a hydraulic control method according to the oil temperature state of this embodiment will be described based on the flowchart of FIG.

When the ignition switch is turned on and the program starts (step 201), it is first determined whether or not the vehicle is starting for the first time (202).

If step 202 is YES on the first start, step 20
In 3, the oil temperature is detected, the value of the oil temperature is replaced with ETEMP, and the FLG register counter shown in FIG. 2 is set to "00000001".

Then, the process proceeds to step 204. In this step 204, since the ignition switch is turned on, the vehicle starts after the engine is started and the hydraulic clutch 74 is completely engaged so that the lockup is performed. As shown, each solenoid valve 52, 6 according to the set schedule 1
The drive frequency of 0 and 68 is switched. In this step 204, the oil temperature of 0 ° C is replaced with TEMP1, and the oil temperature of -10 ° C is changed to TEM.
Replace with P2, and replace oil temperature of -20 ° C with TEMP3.

Next, in step 205, ETEMP is compared with TEMP1. In this step 205, when ETEMP ≧ TEMP1 and the oil temperature is equal to or higher than the predetermined value of 0 ° C., the viscosity of the oil is relatively small, so the FLG register count is left as it is (count is “00000001”) ( 211), the end (21
After 2), the first, second and third three-way solenoid valves 52, 60, 68 are driven at a frequency of 100 Hz.

In step 205, ETEMP <TEMP1 and the oil temperature is 0 ° C.
If less than, the viscosity of the oil is small, so
The count of the FLG register is shifted to the left by one (the count is "00000001") (206).

Then, in step 207, ETEMP and TEMP2 are compared. In this step 207, when ETEMP ≧ TEMP2 and the oil temperature is 0 ° C. to −10 ° C., the FLG register count is left as it is (count is “00000010”) (211),
Pass each solenoid valve 52, 60, 68 through the end (212) at a frequency of 50H.
Drive at z to raise the oil pressure slightly and obtain a predetermined oil pressure.

In step 207, when ETEMP <TEMP1, the oil temperature is -10.
If the temperature is below ℃, the viscosity of the oil will be even higher.
The count of the G register is further shifted to the left by one (the count is "00000100") (208).

Then, in step 209, ETEMP and TEMP3 are compared. In this step 209, when ETEMP ≧ TEMP3 and the oil temperature is −10 ° C. to −20 ° C., the FLG register count is left as it is (“00000100”) (211) and the end (21
After 2), each solenoid valve 52, 60, 68 is driven at a frequency of 25 Hz to further increase the hydraulic pressure to obtain a predetermined hydraulic pressure.

In step 209, the oil temperature is −20 when ETEMP <TEMP3.
If the temperature is lower than 0 ° C, the viscosity of the oil is higher than that in the above case, and therefore the process proceeds to step 210 and shifts ((
0001000 ") (211), and through the end (212), each solenoid valve 52, 60, 68 is driven at a frequency of 25 Hz to raise the hydraulic pressure to obtain a predetermined hydraulic pressure.

On the other hand, if the vehicle is not the first start,
In the case of O, the process proceeds to step 213 and, as shown in Appendix 2,
According to the set schedule 2, each solenoid valve 52, 60, 68
Change the drive frequency of. In this step 213, the detected oil temperature is replaced with TEMP, the oil temperature -5 ° C is replaced with TEMP2, and the oil temperature -15 ° C is replaced with TEMP3, and the count of the FLG register shown in Fig. 2 is set to "00000001". To do.

Then, in step 214, TEMP is compared with TEMP2. In this step 214, if TEMP ≧ TEMP2 and the oil temperature is −5 ° C. or higher, the process proceeds to step 215, where TEMP is replaced with the code A, and this code A is replaced with ETEMP in step 225. , Step 207
To jump to the same process as above. in this way,
When the oil temperature is -5 ° C or higher, which is the predetermined value in this case,
The FLG register count is unchanged (the count is "00000
001 ") and the solenoid valve is driven at a frequency of 100 Hz.

In step 214, TEMP <TEMP2 and the oil temperature is -5 ° C.
If less, proceed to step 216.

In this step 216, TEMP and TEMP3 are compared with a temperature value obtained by adding, for example, −3 ° C. as hysteresis. In this step 216, in the case of a temperature value obtained by adding -3 ° C as hysteresis to TEMP ≤ TEMP3, the process proceeds to step 215, TEMP is replaced with the code A in this step 215, and this code A is replaced with ETEMP in step 225. Replacement,
The process jumps to step 207 and is processed as described above. In this way, when the oil temperature is low, the FLG register count is shifted to "0000100" and each solenoid valve 52, 6
A predetermined hydraulic pressure is obtained by driving 0 and 68 at a frequency of 25 Hz.

If the temperature value obtained by adding -3 ° C as hysteresis to TEMP> TEMP3 in step 216, step 21
Proceed to 7. In this step 217, TEMP and TEMP
Compare with 3. In this step 217, TEMP ≧ TE
If MP3, proceed to step 218. This step
The 218 odor has a hysteresis of -3 on ETEMP and TEMP2.
Compare the temperature value with the addition of ° C. This step 218
At ETEMP ≤ ETEMP2 as a hysteresis of -3 ℃
In the case of the added temperature value, TEMP is replaced with the code A in step 215, and this code A is replaced with ETEMP in step 225, and the process jumps to step 207 and is processed in the same manner as described above. In this case, each of the first, second and third three-way solenoid valves 52, 6
0 and 68 are driven at a frequency of 50 Hz.

If the temperature value obtained by adding -3 ° C as hysteresis to ETEMP> TEMP2 in the above step 218,
Proceed to 219 to compare TEMP and TEMP2. This step
In 219, when TEMP <TEMP2 and the oil temperature is less than -5 ° C, the process proceeds to step 220, and the temperature value obtained by adding -3 ° C as hysteresis to TEMP2 in this step 220 is replaced with the code A, and this code A Is replaced with ETEMP in step 225, the process jumps to step 207, and is processed in the same manner as described above.

In step 219, the oil temperature is -5 ° C when TEMP ≤ TEMP2.
In the above case, the code A is replaced with the TEMP29 code A in step 221, the code A is replaced with ETEMP in step 225, and the process jumps to step 207 to perform the same processing as described above.

In step 217, if TEMP <TEMP3, ETEMP
If is less than −15 ° C., the process proceeds to step 222, and in this step 222, ETEMP and TEMP3 are compared. In this step 222, if ETEMP <TEMP3, step 223
In step 225, the temperature value obtained by adding -3 ° C as a hysteresis to TEMP3 is replaced with the code A, and this code A is E in step 225.
Instead of TEMP, jump to step 207 and perform the same processing as above.

In step 222, if ETEMP ≧ TEMP3,
In step 224, TEMP3 is replaced with the code A, and this code A is replaced with ETEMP in step 225, and the process jumps to step 207 to be processed as described above.

Next, the hydraulic control method according to the vehicle speed in this embodiment will be described based on the flowchart of FIG.

When the program starts (step 301), it is determined whether the clutch is locked up, that is, when the clutch pressure change control is not performed, that is, whether the drive mode has been entered (302).

If step 302 is NO, exit this program (3
If the answer is YES, it is determined whether the drive frequency of the first, second and third three-way solenoid valves 52, 60, 68 is 100 Hz which is the basic frequency (303). And step 303
If YES, it is judged whether the vehicle speed is 60 km / H or higher (304).

If the vehicle speed is less than 60 km / H in step 304, the program is ended (306), and if the vehicle speed is 60 km / H or more, the drive frequency is switched from the basic frequency of 100 Hz to 50 Hz (305), and the program is ended (305). 306) Let me.

Further, if the judgment in step 303 is NO, it is judged whether or not the drive frequency is 50 Hz (307), and if the step 307 is NO, the program is ended (306),
If YES, determine whether the oil temperature is -5 ° C or higher (3
08). If the oil temperature is less than -5 ° C in step 308, the program ends (306), and if the oil temperature is -5 ° C or more, it is determined whether the vehicle speed is 55 km / H or less (30
9).

Then, in step 309, when the vehicle speed exceeds 55 km / h, the drive frequency is switched from 50 Hz to the basic frequency of 100 Hz (310), and the program ends (306).

As a result, the drive frequencies of the first, second and third three-way solenoid valves 52, 60 and 68 can be switched according to the vehicle speed, and the first, second and third three-way solenoid valves which are pressure control valve means during high speed traveling. Five
The durability of 2, 60, 68 can be improved, which is economically advantageous. Actually, drive frequency is 100Hz when driving at high speed
By switching to 50Hz or 50Hz, the durability is doubled.

In addition, when traveling at a low speed of 55 km / H or less, the first, second,
By setting the drive frequency of the third three-way solenoid valves 552, 60, 68 to 100 Hz, which is a fundamental frequency higher than that during high-speed running, pressure fluctuations in the hydraulic circuit can be reduced, which causes vehicle occupant discomfort. Can be reliably prevented.

Furthermore, when the vehicle runs at a high speed of 60 km / H or more, the drive frequency of the first, second, and third three-way solenoid valves 52, 60, 68 is changed from the basic frequency of 100 Hz to 50 Hz, which is smaller than the hydraulic frequency. Even if the pressure of the circuit fluctuates, there is no inconvenience because the vibration generated in the steering wheel, seat, etc. due to the speed becomes large.

Furthermore, in general, the clutch hydraulic pressure chamber is smaller than the shift sheep chamber, so that the clutch pressure change control is more susceptible to the hydraulic pulsation than the shift control, and the cause of vibration to the vehicle is also increased. However, when the drive frequency of the pressure control valve means for controlling the hydraulic pressure during low speed traveling is switched to a value higher than during high speed traveling, this switching control operation is performed at times other than the clutch pressure changing control, thereby changing the clutch pressure as described above. Vibrations caused by control can be suppressed.

The present invention is not limited to the above-mentioned embodiments, and various application modifications are possible.

For example, in the embodiment of the present invention, each solenoid valve 52, 6
The drive frequency can be switched between 0 and 68 at any time, but when transmitting the torque by sliding the clutch in the normal start mode and the special start mode,
In order to prevent the occurrence of driving and shock, it is possible to limit the time in the neutral mode, the hold mode, and the drive mode other than the start mode.

Further, in this embodiment, the first vehicle speed detecting means is used.
-Although the method of using the desired vehicle speed detection signal of the third rotation detector is used, various devices can be used as long as they can detect the vehicle speed, and a new vehicle speed detector should be provided at a desired portion. You can also

〔The invention's effect〕

As is apparent from the above detailed description, according to the present invention,
The drive frequency of the pressure control means that controls the hydraulic pressure during low speed traveling is switched to a value higher than that during high speed traveling, and this switching control operation is performed at times other than the clutch pressure change control, so that the pressure control means during high speed traveling is controlled. It is possible to improve durability and is economically advantageous.

Further, when the vehicle is traveling at low speed, the drive frequency of the pressure control valve means is switched to be larger than that when traveling at high speed, whereby the pressure fluctuation of the hydraulic circuit can be reduced, and it is possible to surely avoid the inconvenience of causing vehicle passengers to feel uncomfortable. It is a thing.

Further, even if the drive frequency of the pressure control valve means is switched to a small basic frequency during high-speed traveling, pressure fluctuations in the hydraulic circuit occur, and large vibrations also occur in the handle, seat, etc. depending on the speed, so there is no inconvenience. Is.

Furthermore, when the drive frequency of the pressure control valve means for controlling the hydraulic pressure during low speed traveling is switched to a value higher than that during high speed traveling, this switching control operation is performed at times other than the clutch pressure changing control, so that the clutch pressure changing control is performed. It is possible to suppress vibration caused by.

[Brief description of drawings]

1 to 8 show an embodiment of the present invention, FIG. 1 is a flow chart for explaining a hydraulic pressure control method according to a vehicle speed, FIG. 2 is a flow chart for explaining a hydraulic pressure control method according to an oil temperature state, and FIG. FIG. 4 is an explanatory view of FLG register counting, FIG. 4 is a view showing solenoid valve output pressure characteristics according to drive frequency, and FIG.
Fig. 6 is a schematic diagram of a continuously variable transmission, Fig. 6 is a schematic diagram illustrating a hydraulic circuit and a control unit of the continuously variable transmission, Fig. 7 is a sectional view of a primary control valve, and Fig. 8 is a sectional view of a three-way solenoid valve. It is a figure. In the figure, 2 is a continuously variable transmission, 4 is a belt, 6 is a driving side pulley, 12 is a driven side pulley, 18 is a rotating shaft, 30 is an oil pump, 38 is a first oil passage, 40 is a second oil passage. , 42 is a pressure control valve means, 44 is a primary pressure control valve, 46
Is a third oil passage, 48 is a constant pressure control valve, 50 is a fourth oil passage, 52 is a first three-way solenoid valve for primary pressure control, 54 is a line pressure control valve, 56 is a fifth oil passage, and 58 is a sixth oil passage. A passage, 60 is a second three-way solenoid valve for line pressure control, 62 is a clutch pressure control valve, 64 is a seventh oil passage, 66 is an eighth oil passage,
Reference numeral 68 is a third three-way solenoid valve for controlling clutch pressure, 70 is a ninth oil passage, 72 is a tenth oil passage, 74 is a hydraulic clutch, 78 is a pressure sensor, 90 is a control unit, 92 is an oil temperature sensor, and 93 is an input. A shaft rotation detection gear, 94 is a first rotation detector, 95 is an output shaft rotation detection gear, 96 is a second rotation detector, 97 is an output transmission gear, and 98 is a third rotation detector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsumi Takumi 840 Chiyoda-cho, Himeji City, Hyogo Prefecture Mitsubishi Electric Co., Ltd. Himeji Manufacturing Co., Ltd. (72) Inventor Hiroaki Yamamoto 1 at 13 Sadamoto-cho, Himeji City, Hyogo Prefecture Mitsubishi Electric Control Software Himeji Business Co., Ltd. (56) Reference JP-A-62-52267 (JP, A)

Claims (2)

[Claims] Claim: What is claimed is: 1. A groove width between the fixed pulley portion piece and a movable pulley portion piece that is attached to the fixed pulley portion piece so as to be able to come into contact with and separated from the fixed pulley portion piece is increased by hydraulic pressure and wound around the both pulleys. In a continuously variable transmission for a vehicle that performs gear shift control to change the gear ratio by increasing or decreasing the radius of gyration of the belt, pressure control valve means for controlling the hydraulic pressure is provided, and vehicle inspection detection means for detecting the vehicle speed is provided. The control unit switches the drive frequency of the pressure control valve means to a value higher than that during high-speed traveling, and this switching control operation is executed at times other than the clutch pressure change control, and the pressure valve of the vehicle continuously variable transmission is characterized. Drive control method. 2. The control unit sets the drive frequency of the pressure control valve means to a basic frequency of 10 when the vehicle speed becomes 60 km / H or more.
The pressure valve drive control method for a vehicle continuously variable transmission according to claim 1, which is a control unit that controls switching from 0 Hz to 50 Hz.