JPH0721309B2 - Belt ratio controller for continuously variable transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt ratio control device for a continuously variable transmission, and in particular, a vehicle operating state shifts from a normal start mode when starting to a complete running state and a clutch. The present invention relates to a belt ratio control device for a continuously variable transmission that controls the belt ratio by the integrated amount of the target engine speed when the drive mode is entered, which is the case where the gears are completely connected.

[Prior Art] In a vehicle, a transmission is interposed between an internal combustion engine and driving wheels. This transmission system changes the driving force of the drive wheels and the traveling speed in accordance with the traveling condition of the vehicle that changes in a wide range, and makes the internal combustion engine fully exhibit its performance. The transmission is formed between both pulley part pieces of a pulley having a fixed pulley part piece fixed to the rotary shaft and a movable pulley part piece mounted on the rotary shaft so as to be able to come into contact with and separate from the fixed pulley part piece. There is a continuously variable transmission that changes the gear ratio (belt ratio) by increasing or decreasing the radius of rotation of a belt wound around a pulley by increasing or decreasing the width of a groove to transmit power. Examples of this continuously variable transmission include, for example, JP-A-57-186656, JP-A-59-43249, JP-A-59-77159, and JP-A-59-77159.
No. 61-233256, respectively.

[Problems to be Solved by the Invention] By the way, in a conventional belt ratio control device for a continuously variable transmission, a target engine speed NESPR for gear shift control is used.
In controlling the engine speed NE, proportional / integral control is adopted, but it always operates in drive mode.

However, in order to improve the controllability of the engine speed NE, the target engine speed NESPR of Target engine speed NE without changing the integration correction amount
The belt ratio is controlled by the predetermined integral amount of SPR.

In order to set the ratio to full low F / L in the normal start mode, open loop control RDIMOD is performed to drive the ratio solenoid with a duty of 0%.

Further, in the drive mode, the closed loop control RNEMOD for feedback controlling the engine speed NE to the target engine speed NESPR is performed.

Therefore, when the vehicle operating state shifts from the normal start mode to the drive mode, the shift control of the continuously variable transmission shifts from the open loop control RDIMOD to the closed loop control RNEMOD.

In this open loop control RDIMOD, the ratio solenoid is driven with a constant duty of 0%, and oil is not supplied to the primary sheave.

Further, in the closed loop control RNEMOD, feedback control, which is proportional / integral control for controlling the engine speed NE to the target engine speed NESPR, is performed, and the ratio solenoid is driven by the intermediate duty to supply oil to the primary sheave. It is being supplied.

For this reason, when supplying oil to a large-volume primary sheave, it is assumed that the drive mode is continuous when the shift control is performed from the state where the primary hydraulic pressure is zero, which shifts from the normal start mode to the drive mode. If the primary hydraulic pressure is not zero, the shift control of the former one is delayed, which is disadvantageous in practical use.

Also, due to the delay in the shift control, it becomes difficult for the engine speed NE to converge to the target engine speed NESPR, so the integral correction amount is accumulated, and the primary hydraulic pressure rises sharply. There is an inconvenience of giving an adverse effect and causing various adverse effects on the clutch control.

Further, in the shift control, since the proportional / integral gain is set with the normal drive mode as a reference, it is not suitable for the vehicle operating state shifting from the normal start mode to the drive mode, and the engine speed NE
Has the inconvenience of causing hunting.

Therefore, in order to eliminate the above-mentioned inconvenience, an object of the present invention is to shift the belt ratio control device of a continuously variable transmission from a normal start mode at the time of starting to a complete running state and completely engage the clutch. This is the case when the drive mode, which is the case when the drive mode is changed, is provided with a control unit for increasing the integral correction amount of the target engine speed for a predetermined time and controlling the belt ratio. The engine speed can be quickly converged to the target engine speed, a rapid increase in the primary pressure is prevented, the adverse effect on the line pressure and the clutch pressure is prevented, and hunting occurs in the drive mode. A continuously variable transmission that can be reduced and can be dealt with only by improving a part of the program in the control unit. It is to realize the Lu ratio control device.

[Means for Solving the Problems] In order to achieve this object, the present invention is directed to a space between both pulley part pieces of a fixed pulley part piece and a movable pulley part piece that is attached to and detachable from the fixed pulley part piece. In the belt ratio control device of the continuously variable transmission for controlling the gear change to change the gear ratio by increasing or decreasing the radius of rotation of the belt wound around the pulleys by increasing or decreasing the groove width of the It is characterized in that a control unit is provided to control the belt ratio by increasing the integral correction amount of the target engine speed for a predetermined time when the drive mode, which is the case where the clutch is completely engaged after changing the various running states, is set. To do.

[Operation] According to the above-described invention, when the normal start mode at the start is shifted to the complete running state and the drive mode is shifted to the case where the clutch is completely engaged, the control unit controls the primary sheave for a predetermined time. Supply a large amount of oil, quickly converge the engine speed to the target engine speed, prevent a sudden increase in primary pressure,
The adverse effect on the line pressure and the clutch pressure is prevented to reduce the occurrence of hunting in the drive mode, and only a part of the program of the control unit is improved.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 3 show an embodiment of the present invention. Third
In the figure, 2 is a belt drive type continuously variable transmission, 2A is a belt, 4 is a drive side pulley, 6 is a drive side fixed pulley part,
Reference numeral 8 is a drive side movable pulley section piece, 10 is a driven side pulley section, 12 is a driven side fixed pulley section piece, and 14 is a driven side movable pulley section piece. As shown in FIG. 4, the drive side pulley 4 includes a drive side fixed pulley portion 6 fixed to a rotary shaft 16 and a rotary shaft 16.
And a drive side movable pulley portion 8 mounted on the rotary shaft 16 so as to be movable in the axial direction and not rotatable. Also,
Like the drive pulley 4, the driven pulley 10 also has a driven fixed pulley portion 12 and a driven movable pulley portion 14.

The drive side movable pulley part 8 and the driven side movable pulley part
First and second housings 18 and 20 are attached to 14 respectively, and first and second hydraulic chambers 22 and 24 are formed respectively. At this time, in the second hydraulic chamber 24 on the driven side, the second hydraulic chamber 24
An urging means 26 including a spring or the like for urging the second housing 20 in the expanding direction is provided.

An oil pump 28 is provided on the rotary shaft 16, and the oil pump 28 is communicated with the first and second hydraulic chambers 22 and 24 by the first and second oil passages 30 and 32, respectively. A primary pressure control valve 34, which is a shift control valve that controls the primary pressure, which is the sheave pressure of the input shaft, is interposed in this.
The control in the line pressure by the third oil passage 36 to the first oil passage 30 of the oil pump 28 side of the primary pressure control valve 34 (typically 5~25kg / cm ²⁾ to a constant pressure (3-4 kg / cm ²⁾ Communicating with the constant pressure control valve 38,
34 for the primary oil pressure control by the 4th oil passage 40
The three-way solenoid valve 42 is communicated.

Further, a line pressure control valve 44 having a relief valve function for controlling the line pressure that is a pump pressure is connected in the middle of the second oil passage 32 by a fifth oil passage 46, and the line pressure control valve 44
The sixth oil passage 48 connects the second three-way solenoid valve 50 for controlling the line pressure.

Further, the line pressure control valve 44 has a second position
A clutch pressure control valve 52 for controlling the clutch pressure is connected in the middle of the second oil passage 32 on the hydraulic chamber 24 side by a seventh oil passage 54, and the clutch pressure control valve 52 is controlled by an eighth oil passage 56 for clutch pressure control. The third direction solenoid valve 58 is communicated.

Further, the primary pressure control valve 34, the first solenoid valve 42 for primary pressure control, the constant pressure control valve 38, the sixth oil passage 48,
The second solenoid valve 50 for line pressure control and the clutch pressure control valve 52 are connected by the ninth oil passage 60, respectively.

The clutch pressure control valve 52 is connected to the hydraulic starting clutch 62 by a tenth oil passage 64, and a pressure sensor 68 is connected in the middle of the tenth oil passage 64 by an eleventh oil passage 66. The pressure sensor 68 can directly detect the hydraulic pressure when controlling the clutch pressure in the hold and start modes, and contributes to commanding the detected hydraulic pressure to be the target clutch pressure. Further, since the clutch pressure becomes equal to the line pressure in the drive mode, it also contributes to the line pressure control.

An input shaft rotation detection gear 70 is provided outside the first housing 18, and a first rotation detector 72 on the input shaft side is provided near the outer peripheral portion of the input shaft rotation detection gear 70. An output shaft rotation detection gear 74 is provided outside the second housing 20, and a second rotation detector 76 is provided on the output shaft side near the outer peripheral portion of the output shaft rotation detection gear 74. Then, the first rotation detector 72 and the second rotation detector
The detection signal from the rotation detector 76 is output to the control unit 82, which will be described later, to grasp the engine speed and the belt ratio.

The hydraulic starting clutch 62 is provided with an output transmission gear 78,
A third rotation detector 80 for detecting the rotation of the final output shaft is provided near the outer peripheral portion of the gear 78. That is, the third rotation detector 80 detects the rotation of the reduction gear, the differential gear, the drive shaft, and the final output shaft directly connected to the tire, and can detect the vehicle speed. The second rotation detector 76 and the third rotation detector 80 can also detect the rotation around the hydraulic starting clutch 62, which contributes to the detection of the clutch slip amount.

Further, a throttle opening of a carburetor (not shown) of the vehicle, engine rotation from the first to third rotation detectors 72, 76, 80,
A control unit 82 for inputting various conditions such as vehicle speed and changing the duty ratio to perform shift control is provided. The control unit 82 controls the first three-way solenoid valve 42 for primary pressure control, the constant pressure control valve 38, and the line pressure control first. The two-way three-way solenoid valve 50 and the third three-way solenoid valve 58 for clutch pressure control are controlled to open and close, and the pressure sensor 68 is also controlled. Further, the various signals input to the control unit 82 and the functions of the input signals will be described in detail. The detection signals of the shift lever position ... P, R, N, D, L, etc. Required line pressure, ratio, clutch control, carburetor throttle opening detection signal ... Engine torque is detected from the memory input in the program in advance, target ratio or target engine speed is determined, carburetor idle position detection signal …… Compensation of the carburetor throttle position sensor and improvement of control accuracy, accelerator pedal signal …… Detects the driver's intention based on the accelerator pedal depression state, determines the control direction during running or starting, and brake signal …… Detects whether the brake pedal is depressed or not, determines the control direction such as clutch disengagement, and Mode option signal …… The performance of the vehicle is sports (or economy)
Use as an option for

The control unit 82, the target engine speed NESPR of the predetermined engine speed for a predetermined time when the vehicle operating state transitions from the normal start mode when the vehicle is starting to the complete traveling state and when the clutch is completely engaged to the drive mode. It is configured to control the belt ratio by increasing the integral correction amount.

More specifically, the control unit 82 has first and second integration loops A and B as shown in FIG. 1, and when the vehicle operating state shifts from the normal start mode to the drive mode, For example, target engine speed NE for RNETIM seconds only
The first and second integration loops A and B are used in order to increase the integral correction amount of SPR.

Reference numeral 84 is a piston of the hydraulic starting clutch 62, 86 is an annular spring, 88 is a first pressure plate, 90 is a friction plate, 92 is a second pressure plate, 94 is an oil pan,
96 is an oil filter.

Next, the operation will be described.

In the belt drive type continuously variable transmission 2, as shown in FIG. 4, the oil pump 28 located on the rotary shaft 16 operates in response to the drive of the rotary shaft 16, and the oil is oil pan 94 at the bottom of the transmission. Is absorbed through the oil filter 96. The line pressure, which is the pump pressure, is controlled by the line pressure control valve 44, and if the leakage amount from the line pressure control valve 44, that is, the escape amount of the line pressure control valve 44 is large, the line pressure becomes low,
On the contrary, if it is small, the line pressure will be high.

Further, the line pressure control valve 44 has a shift control characteristic that changes the line pressure in the full low state, the full over top state, and the fixed ratio state to perform three-stage control.

The operation of the line pressure control valve 44 is performed by a dedicated second three-way solenoid valve 50.
The line pressure control valve 44 operates following the operation of the second three-way solenoid valve 50. The second three-way solenoid valve 50 is controlled at a duty ratio of a constant frequency. . That is, when the duty ratio is 0%, the second three-way solenoid valve 50 does not operate at all, the output side is connected to the atmosphere side, and the output hydraulic pressure becomes zero. Also, the duty ratio is 100%
Means that the second three-way solenoid valve 50 operates so that the output side is connected to the atmosphere side, 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 50 is substantially linear, and the line pressure control valve 44 can be operated in an analog manner.
The line pressure can be controlled by arbitrarily changing the duty ratio of the second three-way solenoid valve 55. The operation of the second three-way solenoid valve 50 is controlled by the controller 82.

The primary pressure for shift control is the primary pressure control valve 34
Similarly to the line pressure control valve 44, the operation of the primary pressure control valve 34 is controlled by the dedicated first three-way solenoid valve 42. This first three-way solenoid valve 42
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 52 that controls the clutch pressure is connected to the line pressure side when the maximum clutch pressure is required, and is connected to the atmosphere side when the minimum clutch pressure is set. Like the line pressure control valve 44 and the primary pressure control valve 34, the clutch pressure control valve 52 is also a dedicated third three-way solenoid valve.
The operation is controlled by 58, and the explanation is deleted. The clutch pressure varies within the range from the minimum atmospheric pressure (zero) to the maximum line pressure.

There are four basic patterns for clutch pressure control that will be described later. These basic patterns are: (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: If the shift position is D or R and the throttle is released and there is no intention to run, or if you want to decelerate and cut the engine torque while running, the clutch pressure is low enough to contact the clutch ( 3), Start mode: When starting (normal start) or when trying to re-engage the clutch after clutch disengagement (special start), the engine pressure generated to prevent the engine pressure from rising and to operate the vehicle smoothly. Appropriate level according to (clutch input torque) (4), drive Mode: When the vehicle is in full running and the clutch is fully engaged, there are four clutch pressure levels: high enough to withstand the engine torque. The basic pattern (1) is performed by a dedicated switching valve (not shown) that is interlocked with the shift operation. , 50, 58 duty ratio control. Particularly, in the state (4), the clutch pressure control valve 52 connects the seventh oil passage 54 and the tenth oil passage 64 so that the maximum pressure is generated, and the clutch pressure becomes the same as the line pressure.

Further, the primary pressure control valve 34 and the line pressure control valve 44,
The clutch pressure control valve 52 is the first to third three-way solenoid valve 4
Although controlled by the output hydraulic pressures from 2, 50 and 58, the control hydraulic pressures for controlling the first to third three-way solenoid valves 42, 50 and 58 are constant hydraulic pressures produced by the constant pressure control valve 38. This control oil pressure is always higher than the line pressure, but is a stable and constant pressure. Further, the control oil pressure is also introduced into the respective control valves 34, 44, 52 to stabilize these control valves 34, 44, 52.

Next, electronic control of the belt drive type 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 82, an appropriate line pressure for belt holding and torque transmission, a primary pressure for changing a gear ratio, and a clutch are reliably connected. The respective clutch pressures are set to be applied.

The belt ratio control of the belt drive type continuously variable transmission 2 will be described with reference to FIG.

First, the target engine speed NESPR
Then, the first error between the target engine speed NESPR and the actual engine speed NE is calculated (100). At this time,
When the first error becomes large, the duty ratio becomes large as a result, the opening degree of the primary pressure control valve 34 becomes large, and the shift speed becomes high. The first error is multiplied by a proportional gain (102) to obtain a second error.

Then, it is determined whether the vehicle operating state is the drive mode (104), and the third error is obtained from the second error by the first integral correction amount calculated by the first integration loop A when the drive mode is entered ( 106).

Explaining the first integration loop A, the first error is multiplied by the integration gain (108) to obtain the first integral correction amount.

Further, it is judged whether RNETIM, which makes the integral correction amount large, has become 0 (110), and when RNETIM ≠ 0, the second integration correction amount calculated by the second integration loop B is used to calculate the second error from the second error. 4 Find the error (112).

That is, explaining the second integration loop B, the second error is multiplied by the integration gain (114) to obtain the second integral correction amount, and when the vehicle operating state is the drive mode, the second error is added to the second integral correction amount. And the fourth error is calculated (112).

Then, NNOMR (ratio solenoid null duty value) is added to the fourth error to obtain the fifth error (116), and it is determined whether the open loop control RDIMOD state is the control mode in which the ratio solenoid is driven with a constant duty value. Depending on the value, the error and duty value are selected (11
8), output duty OPWRAT and output duty O
Each solenoid valve is excited by PWRAT.

A belt ratio control flowchart of the belt drive type continuously variable transmission 2 will be described with reference to FIG.

First, a belt ratio control program is started (200) by driving the belt drive type continuously variable transmission 2.

Next, it is judged whether the vehicle is in the normal start mode (202). If YES, the clutch slip
Compare CLUSLP with clutch slip trigger value CSTR (20
4) If NO, determine whether it is in drive mode (20
6) Do.

Then, in the comparison of clutch slip CLUSLP and clutch slip trigger value CSTR (204), if CLUSLP> CSTR, the vehicle operating state is set to open loop control RDIMOD (208), and the return (208) is entered, and CLUSLP is set. ≤
In the case of CSTR, set to drive mode and initialize RNETIM (210).

If the judgment (206) as to whether or not the drive mode is YES, whether or not RNETIM is 0 is judged (212), and if NO (NO), RNETIM is input (214) and the return (208) is executed. ).

Also, RNETIM remains 0 even after the initialization (210) of RNETIM described above.
This leads to a judgment (212).

Then, if the judgment as to whether RNETIM is 0 (212) is NO, 1 is subtracted from RNETIM to make a new RNETIM (216), YES
In this case, the process (216) for subtracting 1 from RNETIM to obtain a new RNETIM is skipped, and the process (218) is reached. In this process (218), the closed loop control RNEMOD is set, the target engine speed NESPR is determined, and then the process proceeds to the return (208).

As a result, when the vehicle driving state shifts from the normal start mode to the drive mode, the first for RNETIM seconds,
Target engine speed NESP by the second integral loop A, B
The integral correction amount of R is made large, a large amount of oil is supplied to the primary sheave for RNETIM seconds, and the engine speed NE can be quickly converged to the target engine speed NESPR, preventing a rapid increase in the primary pressure. In addition, it is possible to prevent the influence of the line pressure and the clutch pressure and reduce the occurrence of hunting in the drive mode, which is practically advantageous.

In addition, the stability of the vehicle can be improved by preventing a rapid increase in the primary pressure when the vehicle operating state shifts from the normal start mode to the drive mode.

Further, since it can be dealt with only by improving a part of the program in the control unit 82, the configuration is not complicated, the size is not increased, the manufacturing is easy, the cost can be kept low, and it is economically advantageous. Is.

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, the first and second integration loops A to increase the integral correction amount of the target engine speed NESPR for a predetermined time when the vehicle operating state shifts from the normal start mode to the drive mode. , B are provided, and the belt ratio is controlled by the integral correction amount doubled by the first and second integration loops A, B. However, when the normal start mode is switched to the drive mode, the control is performed. It is also possible to adopt a configuration in which the integral correction amount of the target engine speed NESPR is simply increased for a predetermined time by the section, and the belt ratio is controlled by the increased integral correction amount.

[Effects of the Invention] As described in detail above, according to the present invention, in the case where the belt ratio control device of the continuously variable transmission shifts from the normal start mode at the start to the complete running state and the clutch is completely engaged. When a certain drive mode is entered, the target engine speed integral correction amount is increased for a predetermined time to provide a control unit to control the belt ratio, so when the vehicle operating state changes from the normal start mode to the drive mode, the target Increase the amount of engine speed integral correction,
A large amount of oil is supplied to the primary sheave for a predetermined time by the control unit, and the engine speed can be quickly converged to the target engine speed to prevent a rapid increase in the primary pressure. It is possible to prevent the adverse effect on the drive mode and reduce the occurrence of hunting in the drive mode. Further, the stability of the vehicle can be improved by preventing a rapid increase in the primary pressure when the vehicle operating state shifts from the normal start mode to the drive mode. Further, since it can be dealt with only by improving a part of the program in the control unit, the structure is not complicated and the cost can be kept low, which is economically advantageous.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, and FIG. 1 is an explanatory view for calculating a target engine speed and a target ratio value.
FIG. 3 is a flow chart for ratio control of the belt drive type continuously variable transmission, and FIG. 3 is a block diagram of the belt drive type continuously variable transmission. In the figure, 2 is a belt drive type continuously variable transmission, 2A is a belt, 4 is a drive side pulley, 10 is a driven side pulley, 30 is a first oil passage, 32 is a second oil passage, and 34 is a primary pressure control valve. , 36 is a third oil passage, 38 is a constant pressure control valve, 40 is a fourth oil passage, 42 is a first three-way solenoid valve, 44 is a line pressure control valve, 46 is a fifth oil passage, 48 is a sixth oil passage, 50 is a second three-way solenoid valve, 52 is a clutch pressure control valve, 54 is a seventh oil passage, 56 is an eighth oil passage, 58 is a third three-way solenoid valve, 60 is a ninth oil passage, 62 is a hydraulic starting clutch, 64 is a 10th oil passage, 66 is an 11th oil passage, 68 is a pressure sensor, 72 is a first rotation detector, 76 is a second rotation detector, 80 is a third rotation detector, 82 is a control unit, and 94 is The oil pan and 96 are oil filters.

Front page continuation (72) Inventor Tatsumi Takumi 840 Chiyoda-cho, Himeji-shi, Hyogo Prefecture Mitsubishi Electric Co., Ltd. Himeji Plant (72) Inventor Hiroaki Yamamoto 1-13 13 Sadamoto-cho, Himeji-shi, Hyogo Mitsubishi Electric Control Software Himeji Corporation Inside the office

Claims (1)

[Claims] Claim: What is claimed is: 1. A fixed pulley portion and a movable pulley portion mounted on the fixed pulley portion so as to be able to come into contact with and separate from each other, so that the groove width between the pulley portions is increased to increase the width of the belt wound around the pulleys. A belt ratio control device for a continuously variable transmission that controls gear shifting to change the gear ratio by increasing / decreasing the radius of gyration. A belt ratio control device for a continuously variable transmission, characterized in that a control unit is provided for increasing the integral correction amount of a target engine speed for a predetermined time when shifting to a mode and controlling a belt ratio.