JP7039129B2 - Control device for continuously variable transmission - Google Patents

Description

The present disclosure relates to a control device for a continuously variable transmission.

Conventionally, when a linear solenoid (hydraulic control valve) is not used for shifting, a dither current is supplied to the linear solenoid to cause a piston movement in the hydraulic control valve, etc., and an automatic transmission for vehicles that removes foreign matter such as sand grains. The control device of the above is disclosed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 11-82724

In the conventional device, when the dither current is supplied to multiple linear solenoids in the same phase, the median value of the actual current is higher than the median value of the current command, and the actual pressure is lower than the command hydraulic pressure for the current command value. There is a problem that it ends up.

The present disclosure has focused on the above problem, and an object of the present disclosure is to suppress a decrease in actual pressure when a dither command is output for two or more base current command values.

In order to achieve the above object, the present disclosure includes a plurality of hydraulic control valves and a controller. The plurality of hydraulic control valves control the pulley hydraulic pressure to the primary pulley and the secondary pulley to which the belt is laid. The controller sets the base current command value to be output to each solenoid of the plurality of hydraulic control valves based on the pulley hydraulic pressure command value to the primary pulley and the secondary pulley. The plurality of hydraulic control valves are a line pressure solenoid valve, a primary pressure solenoid valve, and a secondary pressure solenoid valve. The controller has a power supply voltage fluctuation correction unit that corrects the base current command value when the power supply voltage fluctuates, and a dither control unit that outputs a dither command that superimposes a dither current on the base current command value. When the dither control unit outputs a dither command for three base current command values, it executes a phase shift that shifts the phase of the dither command with respect to at least one other base current command value. do.
When the dither control unit of the present invention 1 outputs dither commands to the three base current command values, the phase shift angle is set to 120 degrees with respect to each other's base current command values.
When the dither control unit of the present invention 2 outputs a dither command to three base current command values, the base current command value of the line pressure solenoid valve is changed to the base current command value of the primary pressure solenoid valve and the secondary pressure solenoid valve. The phase shift angle is set to 180 degrees with respect to the base current command value of.

By executing the phase shift that shifts the phase of the dither command in this way, when the dither command is output for two or more base current command values, the base current command value output to each solenoid becomes equally high. It can be suppressed. Therefore, it is possible to suppress a temporary increase in the current consumption of the controller and suppress a decrease in the power supply voltage. In this way, by suppressing the decrease in the power supply voltage, the correction by the power supply voltage fluctuation correction unit to increase the base current command value is suppressed, the increase in the base current command value is suppressed, and the median current command value is suppressed. It is possible to suppress the median value of the actual current from becoming higher than that of the actual current, and it is possible to suppress the decrease in the actual pressure. According to the present invention 1, by setting the phase shift angle to 120 degrees, it is possible to effectively suppress the decrease in the actual pressure when the dither command is output for the three base current command values. In the second invention of the present application, the decrease in the actual pressure can be suppressed by setting the phase shift angle of one base current command value to 180 degrees with respect to the other two base current command values.

It is an overall system diagram which shows the belt type continuously variable transmission to which the control device of this disclosure is applied. It is a block diagram which shows the structure of the dither control system included in the CVT controller and the hydraulic control valve of this disclosure. It is a current waveform diagram which shows an example of the current waveform applied to the solenoid at the time of dither ON by the dither operation determination from the dither control unit. It is a flowchart which shows the flow of the control process by the dither command executed in the dither control part of the CVT controller of this disclosure. FIG. 3 is a current waveform diagram of the dither command used in the control process by the dither command of the first embodiment and showing the angle of the phase shift. It is a figure which shows the solenoid drive voltage, the solenoid current value, and the hydraulic pressure in the control of the comparative example. It is a current waveform diagram of the dither command used in the control process by the dither command of the comparative example, and the angle of a phase shift is in phase. It is a time chart which shows each characteristic of a current value, a line pressure PL, a secondary pressure Psec, and a primary pressure Ppri in the control of a comparative example. It is a time chart which shows each characteristic of the current value, the line pressure PL, the secondary pressure Psec, and the primary pressure Ppri in the control of Example 1. FIG. FIG. 3 is a current waveform diagram of the dither command used in the control process by the dither command of the second embodiment and showing the angle of the phase shift. It is a time chart which shows each characteristic of the current value, the line pressure PL, the secondary pressure Psec, and the primary pressure Ppri in the control of Example 2. FIG.

Hereinafter, the best mode for realizing the continuously variable transmission control device of the present disclosure will be described with reference to Examples 1 and 2 shown in the drawings.

The control device for the continuously variable transmission according to the first embodiment is applied to an engine-equipped vehicle such as an engine vehicle or a hybrid vehicle in which the transmission is a belt-type continuously variable transmission and the engine is mounted as a driving drive source for traveling.

The overall system configuration of the belt-type continuously variable transmission CVT will be described with reference to FIG.

The belt-type continuously variable transmission CVT includes a primary pulley 1, a secondary pulley 2, and a belt 3.

The primary pulley 1 is formed by a combination of a fixed pulley 11 having a sheave surface 11a and a drive pulley 12 having a sheave surface 12a. Drive torque from a traveling drive source (engine, motor, etc.) is input to the primary pulley 1. The drive pulley 12 is formed with a primary pressure chamber 13 that hydraulically drives the drive pulley 12 with respect to the fixed pulley 11.

The secondary pulley 2 is formed by a combination of a fixed pulley 21 having a sheave surface 21a and a drive pulley 22 having a sheave surface 22a. The secondary pulley 2 outputs drive torque to the drive wheels via the final reducer or the like. The drive pulley 22 is formed with a secondary pressure chamber 23 that hydraulically drives the drive pulley 22 in the axial direction with respect to the fixed pulley 21.

The belt 3 is hung on the sheave surfaces 11a and 12a of the primary pulley 1 and the sheave surfaces 21a and 22a of the secondary pulley 2. The belt 3 shifts steplessly by changing the facing distance between the sheave surfaces 11a and 12a and the facing distance between the sheave surfaces 21a and 22a. The belt 3 is formed of, for example, a chain belt or the like in which two pins having an arcuate surface are stacked back to back and torque is transmitted by pulling them connected by a large number of links. When the belt 3 has the highest gear ratio, the contact radius with respect to the primary pulley 1 is the maximum radius, and the contact radius with respect to the secondary pulley 2 is the minimum radius. When the belt 3 has the lowest gear ratio, the contact radius with respect to the primary pulley 1 is the minimum radius, and the contact radius with respect to the secondary pulley 2 is the maximum radius.

The hydraulic control system of the belt type stepless transmission CVT includes an oil pump 4, a line pressure solenoid valve 5 (one of a plurality of hydraulic control valves), and a primary pressure solenoid valve 6 (one of a plurality of hydraulic control valves). ) And a secondary pressure solenoid valve 7 (one of a plurality of hydraulic control valves). Each of these three valves (hereinafter referred to as hydraulic control valves 5, 6 and 7) has a solenoid movable portion such as a spool that is movable by a solenoid current applied to the solenoids 5a, 6a and 7a. The hydraulic control valves 5, 6 and 7 have a form in which the control pressure at which the command current is output at the minimum is maximized and the control pressure at which the command current is output at maximum is minimized.

The line pressure solenoid valve 5 regulates the line pressure PL as the shifting pressure. More specifically, the line pressure solenoid valve 5 regulates the line pressure PL, which is the highest hydraulic pressure as the shift pressure, based on the pump discharge pressure from the oil pump 4.

The primary pressure solenoid valve 6 regulates the primary pressure Ppri of the primary pulley 1. More specifically, the primary pressure solenoid valve 6 uses the line pressure PL as the main pressure and regulates the primary pressure Ppri leading to the primary pressure chamber 13. For example, at the highest gear ratio, the primary pressure Ppri is set to the line pressure PL, and the gear ratio is set to be lower as it shifts to the lower gear ratio side.

The secondary pressure solenoid valve 7 regulates the secondary pressure Psec of the secondary pulley 2. More specifically, the secondary pressure solenoid valve 7 uses the line pressure PL as the main pressure and regulates the secondary pressure Psec leading to the secondary pressure chamber 23. For example, at the lowest gear ratio, the secondary pressure Psec is set to the line pressure PL, and the gear ratio is set to be lower as it shifts to the higher gear ratio side.

The electronic control system of the belt-type continuously variable transmission CVT includes a CVT controller 8 (controller) that controls the gear ratio of the belt-type continuously variable transmission CVT. The input sensor to the CVT controller 8 includes a vehicle speed sensor 81, an accelerator opening degree sensor 82, a CVT input rotation speed sensor 83, and a CVT output rotation speed sensor 84. Further, as the input sensor to the CVT controller 8, a primary pressure sensor 85, a secondary pressure sensor 86, an oil temperature sensor 87, an inhibitor switch 88 and the like are provided. Furthermore, the CVT controller 8 is provided with information necessary for control such as engine torque information, engine rotation speed information, battery power supply voltage information, etc. from another vehicle-mounted controller 90 via the CAN communication line 91.

The gear ratio control executed by the CVT controller 8 determines the target primary rotation speed by the operating point on the shift schedule specified by the vehicle speed VSP and the accelerator opening APO. The vehicle speed VSP is detected by the vehicle speed sensor 81, and the accelerator opening degree APO is detected by the accelerator opening degree sensor 82. Next, in the gear ratio control, the target primary rotation speed is converted into a hydraulic pressure command value, and the hydraulic pressure command value is converted into a base current command value by the ripple current by PWM control. Subsequently, the gear ratio control is performed by controlling the primary pressure Ppri and the secondary pressure Psec by PWM frequency synchronization type two-degree-of-freedom control (FF + PID). In addition, "PWM control" means pulse width modulation control by a predetermined frequency. "PWM" is an abbreviation for "Pulse Width Modulation". "FF" stands for feedforward control. "PID" is feedback control (FB control) by proportionality (P), integral (I), and derivative (D).

A detailed configuration of a dither control system for superimposing a dither on a ripple current waveform by PWM frequency synchronization type two-degree-of-freedom control (FF + PID) will be described with reference to FIGS. 2 and 3.

As shown in FIG. 2, the CVT controller 8 includes a hydraulic pressure / current conversion unit 18, an electronic caliber correction unit 28, a solenoid current control unit 38, SOL drive ICs 51, 61, 71, and an IF / control switching unit 48. And a dither control unit 58. As the "control cycle", a PWM frequency synchronization function is provided so that the dither frequency can be set by even-numbered division of PWM in order to prevent the swell phenomenon due to dither.

The solenoid current control unit 38 includes an FF compensator 38a, a dither signal output unit 38b, a first adder 38c, a phase matching unit 38d, a subtractor 38e, a PD compensator 38f, and a second adder 38g. , A power supply voltage fluctuation correction unit 38h, and a third adder 38i.

The FF compensator 38a ensures current responsiveness. The dither signal output unit 38b outputs a dither signal to the first adder 38c while a dither operation request is input from the dither control unit 58. This dither signal has an amplitude that reduces the mechanical hysteresis of the hydraulic control valves 5, 6 and 7, and the amplitude is used as a parameter (base current command value, power supply voltage, ENG rotation, PL pressure command value, oil temperature). I remember it as a schedule. The first adder 38c is a dither-separated type that adjusts the dither amplitude only by the amplitude command value.

The phase matching unit 38d performs plant dynamics, a communication delay between the IC and the microcomputer, and phase matching for the current averaging process. The phase matching unit 38d has a gain schedule (FF, phase matching, PD compensation). The PD compensation unit 38f compensates for the current deviation from the subtractor 38e by PD compensation and improves the attenuation characteristics. The power supply voltage fluctuation correction unit 38h corrects the command current when the power supply voltage fluctuates to ensure disturbance suppression. The power supply voltage fluctuation correction unit 38h raises the base current command value output to the solenoids 5a, 6a, 7a when the power supply voltage drops, and lowers the base current command value output to the solenoids 5a, 6a, 7a when the power supply voltage rises. Let me.

The SOL drive ICs 51, 61, 71 transmit the PWM control command value to the solenoid body. Here, the SOL drive ICs 51, 61, 71 have current detection circuits 51a, 61a, 71a for detecting the actual current, and FB controllers 51b, 61b, 71b by the integral I.

The dither control unit 58 acquires belt slip determination information (hydraulic deviation, etc.) for determining the possibility of belt slip occurring during pulley hydraulic control. Then, when it is determined based on the belt slip determination information that there is a high possibility that the belt slip will occur, the dither operation (dither operation) in which the dither current is superimposed on the base current command value output to the solenoids 5a, 6a, 7a. = Outputs a dither operation request to execute dither ON). That is, when it is determined that there is no possibility of belt slip or a situation where the possibility of belt slip is low, the dither operation request is not output and the dither current is sent to the solenoids 5a, 6a, 7a. The base current command value (= dither OFF) that is not superimposed is output. The dither operation request is a "dither command".

Here, when "Diza ON" is set, the current waveform applied to the solenoids 5a, 6a, 7a of the hydraulic control valves 5, 6 and 7 is the ripple current waveform according to the base current command value as shown in FIG. It is switched to the dither operating waveform formed by superimposing the dither current waveform. The "diza current waveform" refers to a rectangular current waveform having a lower frequency (for example, about several tens of Hz) than the ripple current waveform (for example, about several hundred Hz).

When the dither control unit 58 outputs a dither command for two or more base current command values, the phase of shifting the dither command phase from one base current command value to at least one other base current command value. Perform a shift. More specifically, the phase shift is executed by shifting the output timing of the dither command with respect to at least one other base current command value for one base current command value. The dither control unit 58 outputs dither commands to the three base current command values output to the solenoids 5a, 6a, and 7a.

Each step of the control process by the dither command will be described with reference to FIG. The control process in FIG. 4 is performed under the determination permission conditions (brake SW = 0, Sec pressure F / B region, other than N range, spin determination other than, inhibitor SW abnormality, normal hydraulic control mode, Eng rotation allowable region). ,, etc.) is satisfied, processing is permitted. Even if the judgment permission condition is satisfied, the process ends when the abnormal failure condition (Sec pressure sensor abnormality, ETC fail, accelerator opening abnormality, CAN abnormality, Sec rotation sensor abnormality, etc.) is satisfied.

In step S1, the hydraulic pressure deviation (= command pressure-sensor pressure) of the secondary pressure Psec is calculated, and the process proceeds to step S2.

Here, the "command pressure" is when the target primary rotation speed Npri * obtained by the operating point (VSP, APO) in the gear ratio control is converted into the hydraulic pressure command value (Pri pressure command value, Sec pressure command value). , Sec pressure command value (= target Sec pressure) is used. As the "sensor pressure", the Sec sensor pressure (≈actual pressure, actual oil pressure) detected by the secondary pressure sensor 86 is used.

In step S2, following the calculation of the hydraulic pressure deviation in step S1, it is determined whether or not the hydraulic pressure deviation is equal to or higher than the predetermined pressure. If YES (hydraulic pressure deviation ≥ predetermined pressure), the process proceeds to steps S3 and S9, and if NO (hydraulic pressure deviation <predetermined pressure), the process proceeds to step S8.

Here, the "predetermined pressure" is set to a dissociation width (for example, about 0.25 Mpa) at which it can be detected that a dissociation has occurred between the command pressure of the secondary pressure Psec and the sensor pressure. If YES (hydraulic pressure deviation ≥ predetermined pressure), there is a possibility that belt slippage will occur or there is a high possibility that belt slippage will occur. On the contrary, in the case of NO (hydraulic pressure deviation <predetermined pressure), there is no possibility of belt slippage or belt slippage is unlikely to occur.

In step S3, following the determination that the hydraulic pressure deviation ≥ the predetermined pressure in step S2, the phase shift angle is set, and the process proceeds to step S4.

Here, the dither control unit 58 sets the phase shift angle to 360 degrees / n, where n is the number of base current command values that output dither commands. In step S3, the dither control unit 58 outputs dither commands for the three base current command values. Therefore, as shown in FIG. 5, the dither control unit 58 sets the phase shift angle to 120 degrees (360 degrees / 3) with respect to each other's base current command values. That is, the dither control unit 58 shifts the output timing of the dither command with respect to the solenoids 5a, 6a, 7a of the hydraulic control valves 5, 6 and 7.

In step S4, following the setting of the phase shift angle in step S3 or the determination that the end condition is not satisfied in step S5, the dither is turned on and the process proceeds to step S5.

Here, "diza ON" means superimposing the dither current waveform on the ripple current waveform according to the base current command value applied to the solenoids 5a, 6a, 7a of the hydraulic control valves 5, 6 and 7 (). See Figure 3). While the dither is turned on, it is preferable to execute the torque regulation control of the engine according to the actual secondary hydraulic pressure by simultaneous control with the dither operation control. In this case, the occurrence of belt slip is promptly suppressed.

In step S5, following the dither ON in step S4, it is determined whether or not the end condition is satisfied. If YES (the end condition is satisfied), the process proceeds to step S6, and if NO (the end condition is not satisfied), the process returns to step S4.

Here, the "end condition" is defined as when the operation timer count from the dither ON reaches a predetermined time (for example, about 1 sec). The "end condition" may be given under a condition indicating that the slipperiness of the belt 3 has disappeared, such as when the hydraulic pressure deviation <predetermined pressure and a predetermined time has elapsed.

In step S6, following the determination that the end condition is satisfied in step S7 or the determination that NO in step S2, the dither is turned off and the process proceeds to return.

Here, "dither OFF" means applying a ripple current waveform according to a base current command value to the solenoids 5a, 6a, 7a of each hydraulic control valve 5, 6, 7 without superimposing the dither current waveform. To say.

Next, the operation of the first embodiment will be described separately for "control by dither command and its problem in the comparative example" and "control processing action by dither command".

Based on FIGS. 6 to 8, the control by the dither command in the comparative example and its problem will be described.

First, it is known that when a foreign substance enters the hydraulic control valve, it is effective to supply a dither current to the solenoid to cause a piston movement in the valve spool to remove the foreign substance (contamination) (contaminance). See JP-A No. 11-82724, etc.).

For example, as shown in FIG. 6, a case where a current is supplied to a primary pressure solenoid (one example) will be described. The characteristics of the primary pressure solenoid (example) in FIG. 6 are the same in the line pressure solenoid and the secondary pressure solenoid. Therefore, in FIG. 6, the case where the current is supplied to the three solenoids will be described.

When a current is supplied to the three solenoids, the solenoid drive voltage fluctuates and the power supply voltage also fluctuates. Even if the power supply voltage fluctuates, the voltage fluctuation is suppressed by correcting the steady current command value in the section without dither (no dither command) in FIG. That is, when the power supply voltage drops, the current command value output to the solenoid is increased, and when the power supply voltage rises, the current command value output to the solenoid is decreased. As a result, as shown in the section without dither in FIG. 6, the actual current value along with the current command value is output.

On the other hand, in the section with dither (with dither command) in FIG. 6, dither currents are supplied to the three solenoids in the same phase as shown in FIG. That is, the timing of supplying the dither current for each solenoid is the same. Therefore, as shown in FIG. 7, when the dither command rises all at once, the current consumption also rises all at once, so that the voltage fluctuation of the solenoid becomes worse in the section with dither in FIG. 6 than in the section without dither.

Here, if the steady-state current command value is corrected as in the section without dither in FIG. 6, the voltage fluctuation is suppressed even in the section with dither.

However, in the section with dither, the dither current waveform is superimposed on the ripple current waveform (see FIG. 3). Then, if the voltage rises when the dither current waveforms of the three solenoids are all 0 mA, the current command value output to the three solenoids is 0 mA, so that the voltage cannot be further lowered. That is, since the dither current waveforms of the three solenoids are 0 mA, the correction of the voltage fluctuation does not work even if the voltage rises. Therefore, as shown in the section with dither in FIG. 6, the median value of the actual current is higher than the median value of the current command. As a result, as shown in the same section, the actual pressure is lower than the command hydraulic pressure with respect to the median value of the current command.

In the comparative example, the characteristics of the actual pressure with respect to the command hydraulic pressure of each hydraulic pressure are as shown in FIG. That is, the line pressure, the primary pressure, and the secondary pressure are lower than the command hydraulic pressure. The time t1 or later corresponds to the dither ON of the first embodiment. Further, FIG. 8 shows the current value of the secondary pressure solenoid as an example. The characteristics of the current value of the secondary pressure solenoid in FIG. 8 are the same in the current values of the line pressure solenoid and the primary pressure solenoid.

As described above, when a dither command is output to a plurality of solenoids in the same phase, there is a problem that the hydraulic pressure drops. Further, as shown in FIG. 8, the fluctuation of the actual pressure is a situation in which a belt slip may occur or a situation in which a belt slip is likely to occur. That is, as shown in FIG. 8, the actual pressure of the secondary pressure fluctuates and becomes lower than the command hydraulic pressure, so that the supply of dither current may promote belt slippage.

The control processing action by the dither command will be described.

In the case of the above comparative example, the present disclosure focuses on the problem that the hydraulic pressure drops when a dither current is supplied to a plurality of solenoids at the same time. On the other hand, when the dither control unit 58 of the first embodiment outputs dither commands to the three base current command values, the phase shift angle is set to 120 degrees with respect to each other's base current command values.

Next, the control processing action by the dither command will be described with reference to FIG.

When the process is started when the determination permission condition is satisfied, the process proceeds from step S1 to step S2 in the flowchart of FIG. If the determination in step S2 is denied, the process proceeds from step S2 to step S6. In step S6, the dither is turned off by applying the ripple current waveform according to the base current command value without superimposing the dither current waveform on the solenoids 5a, 6a, 7a of the hydraulic control valves 5, 6 and 7. After the dither is turned off, the process proceeds from step S6 to return. Therefore, in FIG. 4, when the determination in step S2 is denied, the above flow is repeated.

On the other hand, in FIG. 4, if the determination in step S2 is affirmed, the process proceeds from step S2 to step S3. In step S3, the dither control unit 58 sets the phase shift angle to 120 degrees (360 degrees / 3) with respect to each other's base current command values, as shown in FIG. After setting the phase shift angle to 120 degrees, the process proceeds from step S3 to step S4.

In step S4, when the dither is turned on and the dither control operation request flag is output based on the dither ON, the base current command value applied to the solenoids 5a, 6a, 7a of the hydraulic control valves 5, 6 and 7 is obtained. The dither current waveform is superimposed on the ripple current waveform due to. At this time, the dither current waveform is superimposed on the ripple current waveform for each solenoid 5a, 6a, 7a by shifting the phase shift angle in step S3 (see FIG. 5). After turning on the dither, the process proceeds from step S4 to step S5.

If the determination in step S5 is denied, the flow from step S4 to step S5 is repeated. If the determination in step S5 is affirmed, the process proceeds from step S5 to step S6, the dither is turned off in step S6, and then the process proceeds from step S6 to return.

Subsequently, the control processing action by the dither command will be described with reference to FIGS. 5 and 9. Note that FIG. 9 shows the current value of the secondary pressure solenoid 7a as an example. Further, the characteristics of the current value of the secondary pressure solenoid 7a in FIG. 9 are the same in the current values of the line pressure solenoid 5a and the primary pressure solenoid 6a.

In this way, the dither current waveform is superimposed on the ripple current waveform for each solenoid 5a, 6a, 7a by shifting the phase shift angle in step S3. As a result, unlike the case of the comparative example, the dither current waveforms of the three solenoids 5a, 6a, and 7a do not become 0 mA all at once (FIG. 5). For example, even if the dither current waveform of two solenoids 6a, 7a is 0 mA among the three solenoids 5a, 6a, 7a, the dither current waveform of one solenoid 5a is larger than 0 mA. Then, even if the voltage rises due to the voltage fluctuation, the base current command value on which the dither current waveform is superimposed can be lowered. That is, even if the voltage rises due to the voltage fluctuation, the correction of the voltage fluctuation is effective. Therefore, the median value of the actual current is higher than the median value of the base current command on which the dither current waveform is superimposed after the time t11 in FIG. 9, which is the dither ON, than after the time t1 in the comparative example. It is suppressed from coming out. As a result, the actual pressure (line pressure PL, primary pressure Ppri, It is possible to effectively suppress the decrease of the secondary pressure Psec).

In addition, at the time before the time t11 in FIG. 9, the actual pressure of the secondary pressure Psec fluctuates. This is a situation in which a belt slip may occur or a situation in which a belt slip is likely to occur. However, after the time t11 when the dither current is supplied, the fluctuation of the actual pressure of the secondary pressure Psec converges as time elapses. Further, the actual pressure of the secondary pressure Psec converges to the command hydraulic pressure. Therefore, the occurrence of belt slip is effectively suppressed by the supply of the dither current in the comparative example, and the occurrence of the belt slip is effectively suppressed by the supply of the dither current in the first embodiment.

As described above, in the control device of the belt type continuously variable transmission CVT of the first embodiment, the effects listed below can be obtained.

(1) A plurality of hydraulic control valves 5, 6 and 7 and a controller (CVT controller 8) are provided.
The plurality of hydraulic control valves 5, 6 and 7 control the pulley hydraulic pressure to the primary pulley 1 and the secondary pulley 2 to which the belt 3 is hung.
The controller (CVT controller 8) outputs base current command values to the solenoids 5a, 6a, 7a of the plurality of hydraulic control valves 5, 6 and 7 based on the pulley hydraulic pressure command values to the primary pulley 1 and the secondary pulley 2. To set.
The controller (CVT controller 8) includes a power supply voltage fluctuation correction unit 38h that corrects the base current command value when the power supply voltage fluctuates, and a dither control unit 58 that outputs a dither command that superimposes a dither current on the base current command value. Has.
When the dither control unit 58 outputs a dither command for two or more base current command values, the dither control unit 58 shifts the output timing of the dither command with respect to at least one other base current command value. Performs a phase shift.

In this way, by performing a phase shift that shifts the phase by shifting the output timing of the dither command, when the dither command is output for two or more base current command values, the base current command value that is output to each solenoid. Can be suppressed to be equally high. Therefore, it is possible to suppress a temporary increase in the current consumption of the controller and suppress a decrease in the power supply voltage. In this way, by suppressing the decrease in the power supply voltage, the correction by the power supply voltage fluctuation correction unit to increase the base current command value is suppressed, the increase in the base current command value is suppressed, and the median current command value is suppressed. It is possible to suppress the median value of the actual current from becoming higher than that of the actual current, and it is possible to suppress the decrease in the actual pressure.

(2) The dither control unit 58 sets the phase shift angle to 360 degrees / n, where n is the number of base current command values that output dither commands.

In this way, even if the number of base current command values is a variable, by setting the phase shift angle according to the number, when outputting dither commands to multiple base current command values, the actual pressure The decrease can be suppressed.

(3) The plurality of hydraulic control valves 5, 6 and 7 are a line pressure solenoid valve 5, a primary pressure solenoid valve 6, and a secondary pressure solenoid valve 7.
The controller (CVT controller 8) sets the base current command values to be output to the solenoids 5a, 6a, 7a of the line pressure solenoid valve 5, the primary pressure solenoid valve 6, and the secondary pressure solenoid valve 7 based on the pulley hydraulic pressure command value. do.
When the dither control unit 58 outputs dither commands for the three base current command values, the dither control unit 58 sets the phase shift angle to 120 degrees with respect to each other's base current command values.

By setting the phase shift angle to 120 degrees in this way, it is possible to effectively suppress the decrease in the actual pressure when the dither command is output for the three base current command values. That is, when the dither command is output for the three base current command values, the voltage fluctuation can be smoothly suppressed, so that the decrease in the actual pressure can be effectively suppressed.

In the second embodiment, similarly to the step S3 of the first embodiment, following the determination that the hydraulic pressure deviation ≧ the predetermined pressure in the step S2, the phase shift angle is set, and the process proceeds to step S4. However, the phase shift angle of Example 2 is different from the phase shift angle of Example 1. That is, in the second embodiment, when the dither control unit 58 outputs a dither command for two or more base current command values, one base current command value is phase-shifted with respect to the other base current command values. Set the angle to 180 degrees. In the second embodiment as well, the dither control unit 58 outputs dither commands to the three base current command values as in the first embodiment. Therefore, as shown in FIG. 10, the dither control unit 58 has a phase of the base current command value output to the solenoid 5a of the line pressure solenoid valve 5 with respect to the base current command value output to the other solenoids 6a and 7a. Set the shift angle to 180 degrees. That is, the dither control unit 58 shifts the output timing of the dither command with respect to the solenoids 5a, 6a, 7a of the hydraulic control valves 5, 6 and 7. Since other configurations are the same as those in the first embodiment, illustration and description will be omitted.

The control processing action by the dither command will be described.

In the case of the above comparative example, the present disclosure focuses on the problem that the hydraulic pressure drops when a dither current is supplied to a plurality of solenoids at the same time. On the other hand, when the dither control unit 58 of the second embodiment outputs a dither command for two or more base current command values, the dither control unit 58 shifts the phase of one base current command value with respect to the other base current command values. Set the angle of to 180 degrees.

Next, a portion different from that of the first embodiment will be described with respect to the control processing action by the dither command based on FIG.

In step S3, as shown in FIG. 10, the dither control unit 58 sets the phase shift angle of the base current command value output to the solenoid 5a with respect to the base current command value output to the other solenoids 6a and 7a by 180. Set to degree. After setting the phase shift angle, the process proceeds from step S3 to step S4.

In step S4, when the dither is turned on and the dither control operation request flag is output based on the dither ON, the base current command value applied to the solenoids 5a, 6a, 7a of the hydraulic control valves 5, 6 and 7 is obtained. The dither current waveform is superimposed on the ripple current waveform due to. At this time, the dither current waveform is superimposed on the ripple current waveform for each solenoid 5a, 6a, 7a by shifting the phase shift angle in step S3 (see FIG. 10).

Subsequently, the control processing action by the dither command will be described with reference to FIGS. 10 and 11. Note that FIG. 11 shows the current value of the secondary pressure solenoid 7a as an example. Further, the characteristics of the current value of the secondary pressure solenoid 7a in FIG. 11 are the same in the current values of the line pressure solenoid 5a and the primary pressure solenoid 6a.

In this way, the dither current waveform is superimposed on the ripple current waveform for each solenoid 5a, 6a, 7a by shifting the phase shift angle in step S3. As a result, unlike the case of the comparative example, the dither current waveforms of the three solenoids 5a, 6a, and 7a do not become 0 mA all at once (FIG. 10). For example, even if the dither current waveform of two solenoids 6a, 7a is 0 mA among the three solenoids 5a, 6a, 7a, the dither current waveform of one solenoid 5a is larger than 0 mA. Then, even if the voltage rises due to the voltage fluctuation, the base current command value on which the dither current waveform is superimposed can be lowered. That is, even if the voltage rises due to the voltage fluctuation, the correction of the voltage fluctuation is effective. Therefore, the median value of the actual current is higher than the median value of the base current command on which the dither current waveform is superimposed when the dither is ON after the time t21 in FIG. 11 than after the time t1 in the comparative example. It is suppressed from coming out. As a result, the actual pressure (line pressure PL, primary pressure Ppri, It is possible to suppress the decrease of the secondary pressure Psec).

In addition, the decrease in the actual pressure is suppressed after the time t21 in FIG. 11 than after the time t1 in the comparative example. Therefore, in the second embodiment, the occurrence of belt slip is suppressed by the supply of the dither current than in the comparative example.

As described above, in the control device for the belt-type continuously variable transmission CVT of the second embodiment, the following effects can be obtained in addition to the effect of (1) of the first embodiment.

(4) When the dither control unit 58 outputs a dither command for two or more base current command values, the phase shift angle of one base current command value with respect to the other base current command value is 180 degrees. Set to.
In this way, by setting the phase shift angle of one base current command value to 180 degrees with respect to the other two base current command values, it is possible to suppress a decrease in the actual pressure. In other words, if the phase shift angle of one base current command value is set to 180 degrees with respect to the other base current command values, the actual pressure will drop when dither commands are output for multiple base current command values. Can be suppressed.

Although the control device for the continuously variable transmission of the present disclosure has been described above based on the first and second embodiments, the specific configuration is not limited to these embodiments, and each claim is within the scope of the claims. Design changes and additions are permitted as long as they do not deviate from the gist of the invention according to the section.

In the first embodiment, when the number of base current command values for outputting the dither command is n, the dither control unit 58 sets n to 3 and sets the phase shift angle to 120 degrees (360 degrees / 3). showed that. However, n is not limited to 3. For example, n may be a numerical value such as 2 or 4. When n is 2, the phase shift angle may be set to 180 degrees (360 degrees / 2). Further, when n is 4, the phase shift angle may be set to 90 degrees (360 degrees / 4). In short, when the dither command is output for two or more base current command values, the phase shift angle may be set to an angle at which the dither current waveform does not become 0 mA all at once. In other words, when the dither command is output for two or more base current command values, if the phase shift angle is set to an angle where the dither current waveform is larger than 0 mA (during the dither operation). good. Here, "when n is 2" is, for example, when a dither command is output with respect to the base current command value output to each solenoid of the line pressure solenoid valve and the primary pressure solenoid valve.

In Examples 1 and 2, an example in which the continuously variable transmission control device of the present disclosure is applied to an engine-equipped vehicle such as an engine vehicle or a hybrid vehicle is shown. However, the continuously variable transmission control device of the present disclosure can be applied to an electric vehicle, a fuel cell vehicle, or the like as long as the vehicle is equipped with a continuously variable transmission by hydraulic control.

CVT Belt type continuously variable transmission 1 Primary pulley 2 Secondary pulley 3 Belt 4 Oil pump 5 Line pressure solenoid valve (one of multiple hydraulic control valves)
5a Solenoid (line pressure solenoid)
6 Primary pressure solenoid valve (one of multiple hydraulic control valves)
6a Solenoid (primary pressure solenoid)
7 Secondary pressure solenoid valve (one of multiple hydraulic control valves)
7a Solenoid (secondary pressure solenoid)
8 CVT controller (controller)
58 dither control unit

Claims (2)

Multiple hydraulic control valves that control the pulley hydraulic pressure to the primary and secondary pulleys to which the belt is hung,
A controller that sets a base current command value to be output to each solenoid of the plurality of hydraulic control valves based on the pulley hydraulic pressure command values for the primary pulley and the secondary pulley.
In the control device of a continuously variable transmission equipped with
The plurality of hydraulic control valves are a line pressure solenoid valve, a primary pressure solenoid valve, and a secondary pressure solenoid valve.
The controller sets the base current command value to be output to each solenoid of the line pressure solenoid valve, the primary pressure solenoid valve, and the secondary pressure solenoid valve based on the pulley hydraulic command value, and the controller sets the base current command value to be output to each solenoid of the line pressure solenoid valve, the primary pressure solenoid valve, and the secondary pressure solenoid valve. It has a power supply voltage fluctuation correction unit that corrects the base current command value, and a dither control unit that outputs a dither command that superimposes the dither current on the base current command value.
The dither control unit is characterized in that when the dither command is output to the three base current command values, the phase shift angle is set to 120 degrees with respect to each other's base current command values. Control device for continuously variable transmission. Multiple hydraulic control valves that control the pulley hydraulic pressure to the primary and secondary pulleys to which the belt is hung,
A controller that sets a base current command value to be output to each solenoid of the plurality of hydraulic control valves based on the pulley hydraulic pressure command values for the primary pulley and the secondary pulley.
In the control device of a continuously variable transmission equipped with
The plurality of hydraulic control valves are a line pressure solenoid valve, a primary pressure solenoid valve, and a secondary pressure solenoid valve.
The controller sets the base current command value to be output to each solenoid of the line pressure solenoid valve, the primary pressure solenoid valve, and the secondary pressure solenoid valve based on the pulley hydraulic command value, and the controller sets the base current command value to be output to each solenoid of the line pressure solenoid valve, the primary pressure solenoid valve, and the secondary pressure solenoid valve. It has a power supply voltage fluctuation correction unit that corrects the base current command value, and a dither control unit that outputs a dither command that superimposes the dither current on the base current command value.
When the dither control unit outputs the dither command to the three base current command values, the base current command value of the line pressure solenoid valve is used as the base current command value of the primary pressure solenoid valve and the secondary pressure. A control device for a stepless transmission characterized in that the phase shift angle is set to 180 degrees with respect to the base current command value of the solenoid valve .

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