JP7227037B2 - Gear control device for continuously variable transmission - Google Patents

Description

The present invention relates to a shift control device for a continuously variable transmission mounted on a vehicle.

In recent years, belt-type continuously variable transmissions (CVTs) have been widely put into practical use as automatic transmissions for vehicles (for example, , see Patent Document 1). Here, the belt-type continuously variable transmission has a primary pulley (drive pulley) provided on the input shaft, a secondary pulley (driven pulley) provided on the output shaft, and a belt stretched over these pulleys. , the gear ratio is changed steplessly by changing the groove width of each pulley to change the winding diameter of the belt. Belts include, for example, chains, metal belts, and dry composite belts. In such a continuously variable transmission, for example, a target gear ratio is set according to parameters indicating the operating state of the vehicle, such as accelerator opening and vehicle speed (or engine speed), and the gear ratio is controlled.

In a belt-type continuously variable transmission, driving force generated by an engine is transmitted from a primary pulley to a secondary pulley via a belt. Here, the pulley side pressure (clamping force) applied to the primary pulley and the secondary pulley is controlled according to the engine torque transmitted by the belt (see Patent Document 2, for example). At this time, if the pulley side pressure is insufficient, the belt slips, hindering power transmission and deteriorating the durability of the belt. Conversely, if the pulley side pressure becomes excessive, the load on the hydraulic source side increases, which in turn causes deterioration in the fuel consumption of the vehicle. Therefore, it is necessary to control the pulley side pressure of the continuously variable transmission so as not to cause the belt to slip and not to be excessive.

JP-A-2004-125072 Japanese Patent Application Laid-Open No. 2001-208183

By the way, in a continuously variable transmission, abnormal noise may occur in a specific operating range. Therefore, it has been desired to prevent the generation of abnormal noise that can occur in a specific driving range without deteriorating drivability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The purpose is to provide an apparatus.

As a result of extensive studies on the above-mentioned problems, the inventors have found that, for example, the abnormal noise is caused by the rocker pins and pulley cone surfaces that constitute the chain of the variator, in an operating region in which the transmission torque is large and the shift speed is high. It was found that a minute slippage occurs between the chain and the vibration force that causes the chain and pulleys to vibrate, resulting in noise. In addition, the inventors have found that pulley rigidity, transmission torque, rocker pin end face angle, clamping force (hydraulic pressure), gear shift speed, oil characteristics, and the like are factors that affect noise generation.

Therefore, a shift control apparatus for a continuously variable transmission according to the present invention comprises accelerator operation amount detection means for detecting the amount of accelerator operation by the driver, vehicle speed detection means for detecting the speed of the vehicle, and a required torque acquisition means for acquiring a driver's required torque; and shift control for controlling the gear ratio by setting a target gear ratio based on the accelerator operation amount or the required torque and the vehicle speed or input rotation speed. wherein the shift control means obtains a change value of the required torque, and when the change value of the required torque is equal to or greater than a first threshold value, the shift control means is compared with the case where the change value is less than the first threshold value. The target gear ratio is set so that the speed becomes gentler.

According to the shift control device for a continuously variable transmission according to the present invention, the change value of the required torque is obtained, and when the change value of the required torque is equal to or greater than the first threshold value, the change value is less than the first threshold value. The target gear ratio is set so that the shift speed becomes gentler than in the case. Therefore, in an operating region where abnormal noise can occur (region where the change value of the required torque is large), the shift speed is moderated, thereby preventing the occurrence of abnormal noise. On the other hand, in the operating region where abnormal noise does not occur, the gear shifting speed is not moderated, that is, the gear shifting speed does not change, so deterioration of drivability can be suppressed. As a result, it is possible to achieve both prevention of abnormal noise that may occur in a specific driving range and drivability.

A gear shift control apparatus for a continuously variable transmission according to the present invention comprises gear ratio acquisition means for acquiring a gear ratio of the continuously variable transmission, accelerator operation amount detection means for detecting an accelerator operation amount by a driver, and vehicle speed. A vehicle speed detection means for detecting a target and shift control means for setting a gear ratio and controlling the gear ratio, wherein the gear shift control means obtains a change value of the gear ratio, and if the change value of the gear ratio is equal to or greater than a second threshold value, the gear ratio is determined. The target gear ratio is set so that the shift speed becomes gentler than when the speed is less than the second threshold value.

According to the shift control device for a continuously variable transmission according to the present invention, the change value of the gear ratio is obtained, and when the change value of the gear ratio is equal to or greater than the second threshold, The target gear ratio is set so that the shift speed becomes gentler than in the case. Therefore, in an operating region where abnormal noise can occur (region where the gear ratio change value is large), the gear shift speed is moderated, thereby preventing the occurrence of abnormal noise. On the other hand, in the operating region where abnormal noise does not occur, the gear shifting speed is not moderated, that is, the gear shifting speed does not change, so deterioration of drivability can be suppressed. As a result, it is possible to achieve both prevention of abnormal noise that may occur in a specific driving range and drivability.

A gear shift control apparatus for a continuously variable transmission according to the present invention comprises gear ratio acquisition means for acquiring a gear ratio of the continuously variable transmission, accelerator operation amount detection means for detecting an accelerator operation amount by a driver, and vehicle speed. A vehicle speed detection means for detecting a target and shift control means for setting a gear ratio and controlling the gear ratio, wherein the gear shift control means obtains a change value of the required torque and a change value of the gear ratio, and the change value of the required torque is equal to or greater than the first threshold value. and the target gear ratio is set such that the shift speed becomes gentler when the change value of the gear ratio is equal to or greater than the second threshold value.

According to the shift control device for a continuously variable transmission according to the present invention, the change value of the required torque and the change value of the gear ratio are obtained, the change value of the required torque is equal to or greater than the first threshold value, and the gear ratio is greater than or equal to the second threshold value, the target gear ratio is set so that the shift speed becomes more moderate. Therefore, in an operating region where abnormal noise can occur (region where the change value of the required torque is large and the change value of the gear ratio is large), the gear shift speed is moderated, thereby preventing the occurrence of abnormal noise. . On the other hand, in the operating region where abnormal noise does not occur, the gear shifting speed is not moderated, that is, the gear shifting speed does not change, so deterioration of drivability can be suppressed. In particular, in this case, it is possible to further limit the conditions under which abnormal noise is generated, so that it is possible to further limit the operating range in which the shift speed is moderated. As a result, it is possible to achieve both prevention of abnormal noise that may occur in a specific driving range and drivability at a higher level.

In the shift control device for a continuously variable transmission according to the present invention, when the shift control means sets the target gear ratio so that the shift speed becomes gentler, the accelerator operation amount or the required torque and the vehicle speed or the input rotation speed , the target gear ratio map in which the relationship with the target gear ratio is determined is preferably switched from the target gear ratio map during normal control to the target gear ratio map set so that the shift speed becomes gentler.

In this way, a target gear ratio map in which the relationship between the accelerator operation amount or the required torque, the vehicle speed or the input rotation speed, and the target gear ratio is determined is converted from the target gear ratio map during normal control to the shift speed. By switching to the target gear ratio map that is set to be gentler, the target gear ratio can be set so that the shift speed becomes gentler.

In the shift control apparatus for a continuously variable transmission according to the present invention, when the speed of the vehicle is equal to or higher than the predetermined speed, the shift control means sets the determination condition (abnormal noise occurrence determination condition, i.e., whether or not to moderate the shift speed). It is preferable to prohibit setting the target gear ratio so that the shift speed becomes gentler even if the judgment condition) is satisfied.

By the way, the higher the vehicle speed, the greater the noise such as road noise and engine noise. That is, in a high vehicle speed region where the vehicle speed is equal to or higher than a predetermined speed, road noise, engine noise, and the like increase, and the sense of incongruity caused by the abnormal noise is relatively reduced. Therefore, in areas where the vehicle speed is high and road noise is large, setting the target gear ratio so that the gear shifting speed becomes moderate is prohibited (not executed), thereby reducing the gear shifting speed (i.e., deteriorating drivability). ) can be avoided.

In the shift control device for a continuously variable transmission according to the present invention, when the shift control means selects the manual shift mode in which the shift ratio is changed according to the driver's manual shift operation, the determination condition (abnormal noise generation determination) is selected. It is preferable to prohibit setting the target gear ratio so as to make the shift speed more moderate even if the condition (that is, the condition for judging whether or not to moderate the shift speed) is satisfied.

By the way, when the manual shift mode in which the gear ratio is changed according to the driver's manual shift operation is selected, it is preferable to give priority to ensuring the power performance required by the driver. Therefore, when the manual shift mode is selected, even if the determination condition is satisfied, by prohibiting (not executing) the setting of the target gear ratio so as to slow the gear shifting speed, the gear shifting speed is reduced. (that is, deterioration of drivability) can be avoided.

In the shift control device for a continuously variable transmission according to the present invention, the shift control means may correct the first threshold value and/or the second threshold value according to the oil temperature of the continuously variable transmission. preferable.

By the way, the conditions under which abnormal noise is generated can be affected by the oil temperature of the continuously variable transmission, that is, by the lubrication state. Therefore, by correcting the first threshold value and/or the second threshold value according to the oil temperature of the continuously variable transmission, it is possible to more appropriately determine the abnormal noise generation condition.

According to the present invention, it is possible to achieve both prevention of abnormal noise that may occur in a specific driving range and drivability.

1 is a block diagram showing the configuration of a shift control device for a continuously variable transmission according to an embodiment together with the configuration of the continuously variable transmission; FIG. It is a figure which shows the gear ratio setting of the continuously variable transmission which concerns on embodiment. FIG. 4 is a diagram showing a shift line (transition of a target gear ratio) during normal control and a shift line (transition of a target gear ratio) when an abnormal noise generation determination condition is satisfied; FIG. 4 is a diagram showing an overview of a target gear ratio map for noise prevention; 5 is a flowchart showing a processing procedure of shift control (abnormal noise prevention target gear ratio setting processing) by the shift control device for a continuously variable transmission according to the embodiment;

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Further, in each figure, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

First, with reference to FIG. 1, the configuration of a speed change control device 1 for a continuously variable transmission according to an embodiment will be described. FIG. 1 is a block diagram showing the configuration of a transmission control device 1 for a continuously variable transmission and a continuously variable transmission 30 to which the transmission control device 1 is applied.

The continuously variable transmission 30 is a continuously variable transmission that automatically and steplessly shifts the gear ratio according to the operating state of the vehicle. The continuously variable transmission 30 is connected to the output shaft 15 of the engine 10, converts the driving force from the engine 10, and outputs it.

The continuously variable transmission 30 includes a primary shaft 32 connected to the output shaft 15 of the engine 10 via a torque converter 20 having a clutch function and a torque amplifying function and a reduction gear 31, and arranged parallel to the primary shaft 32. and a secondary shaft 37 .

A primary pulley 34 is provided on the primary shaft 32 . The primary pulley 34 has a fixed pulley 34a that is joined to the primary shaft 32, and a movable pulley 34b that faces the fixed pulley 34a and is slidably mounted in the axial direction of the primary shaft 32. It is configured such that the distance between the cone surfaces of the pulleys 34a and 34b, that is, the pulley groove width can be changed. On the other hand, the secondary shaft 37 is provided with a secondary pulley 35 . The secondary pulley 35 has a fixed pulley 35a joined to the secondary shaft 37 and a movable pulley 35b slidably mounted in the axial direction of the secondary shaft 37 so as to face the fixed pulley 35a. It is configured so that the width can be changed.

A chain 36 for transmitting driving force is stretched between the primary pulley 34 and the secondary pulley 35 . By changing the groove widths of the primary pulley 34 and the secondary pulley 35 to change the ratio of the winding diameter of the chain 36 to the pulleys 34 and 35 (pulley ratio), the gear ratio can be changed steplessly. Here, if the winding diameter of the chain 36 around the primary pulley 34 is Rp and the winding diameter of the chain 36 around the secondary pulley 35 is Rs, the gear ratio i is expressed as i=Rs/Rp. Therefore, the gear ratio i is obtained by dividing the primary pulley rotation speed Np by the secondary pulley rotation speed Ns (i=Np/Ns).

A hydraulic chamber 34c is formed in the primary pulley 34 (movable pulley 34b). On the other hand, a hydraulic chamber 35c is formed in the secondary pulley 35 (movable pulley 35b). The groove widths of the primary pulley 34 and the secondary pulley 35 are set and changed by adjusting the primary hydraulic pressure introduced into the hydraulic chamber 34c of the primary pulley 34 and the secondary hydraulic pressure introduced into the hydraulic chamber 35c of the secondary pulley 35. be done.

A valve body (control valve) 50 controls the hydraulic pressure for shifting the continuously variable transmission 30 , that is, the primary hydraulic pressure and the secondary hydraulic pressure described above. The valve body 50 adjusts the hydraulic pressure discharged from the oil pump by opening and closing an oil passage formed in the valve body 50 using a spool valve and a solenoid valve (electromagnetic valve) that moves the spool valve. It is supplied to the hydraulic chamber 34 c of the primary pulley 34 and the hydraulic chamber 35 c of the secondary pulley 35 . The valve body 50 also supplies hydraulic pressure to, for example, a forward/reverse switching mechanism that switches the vehicle between forward and reverse.

Shift control of continuously variable transmission 30 is performed by a transmission control unit (hereinafter referred to as “TCU”) 40 . That is, the TCU 40 adjusts the hydraulic pressure supplied to the hydraulic chamber 34c of the primary pulley 34 and the hydraulic chamber 35c of the secondary pulley 35 by controlling the driving of the solenoid valves that constitute the valve body 50 described above. , to change the gear ratio of the continuously variable transmission 30 .

Here, the TCU 40 is connected to an engine control unit (hereinafter referred to as "ECU") 60 for comprehensively controlling the engine 10, for example, through a CAN (Controller Area Network) 100 so as to be able to communicate with each other.

The ECU 60 is connected to an accelerator pedal sensor 62 (corresponding to accelerator operation amount detection means) for detecting the depression amount (operation amount) of the accelerator pedal, that is, the opening degree of the accelerator pedal. Also connected to the ECU 60 are various sensors such as a crank angle sensor 12 for detecting the rotational position of the crankshaft, an air flow meter for detecting the amount of intake air, a water temperature sensor for detecting the temperature of engine cooling water, and an air-fuel ratio sensor. ing.

Here, the ECU 60 determines the cylinder from the output of the cam angle sensor and obtains the engine speed from the output of the crank angle sensor 12 . Further, the ECU 60 acquires various types of information such as the amount of intake air, the degree of opening of the accelerator, the air-fuel ratio of the air-fuel mixture, and the water temperature of the engine based on the detection signals input from the various sensors described above. Then, the ECU 60 comprehensively controls the engine 10 by controlling various devices such as fuel injection amount, ignition timing, electronically controlled throttle valve, etc. based on the acquired various information. Further, the ECU 60 acquires the driver's requested torque according to the accelerator opening. In other words, the ECU 60 functions as a required torque acquisition means set forth in the claims. The ECU 60 transmits information such as the engine speed, the degree of accelerator opening, and the required torque to the TCU 40 via the CAN 100 . Note that the calculation of the required torque described above may be performed on the TCU 40 side.

On the other hand, the TCU 40 includes an output shaft rotation sensor 58 attached near the output shaft (secondary shaft 37) of the continuously variable transmission 30 for detecting the rotation speed of the output shaft, and a primary pulley sensor for detecting the rotation speed of the primary pulley 34. A rotation speed sensor 57, a turbine rotation speed sensor 56 for detecting the turbine rotation speed of the torque converter 20, and the like are connected.

Here, a shift lever (select lever) 51 is provided on the vehicle floor or the like for receiving an operation by the driver to selectively switch between an automatic shift mode (“D” range) and a manual shift mode (“M” range). is provided. A range switch 59 is attached to the shift lever 51 so as to move in conjunction with the shift lever 51 to detect the selected position of the shift lever 51 . The range switch 59 is connected to the TCU 40 , and the detected selected position of the shift lever 51 is read into the TCU 40 . In addition to the "D" range and "M" range, the shift lever 51 can be selectively switched between the parking "P" range, the reverse "R" range, and the neutral "N" range.

The shift lever 51 is turned on when the shift lever 51 is positioned on the "M" range side, i.e., when the manual shift mode in which the gear ratio is switched according to the shift operation of the driver is selected, and the shift lever 51 is turned on. An M range switch 52 is incorporated that is turned off when positioned on the "D" range side, that is, when an automatic transmission mode is selected in which the transmission gear ratio is automatically changed according to the operating conditions of the vehicle. M range switch 52 is also connected to TCU 40 .

On the other hand, on the rear side of the steering wheel 53, a plus (+) paddle switch 54 and a minus (-) paddle switch 55 are provided for accepting a shift operation (shift request) by the driver in the manual shift mode ( Hereinafter, the plus paddle switch 54 and the minus paddle switch 55 may be collectively referred to as "paddle switches 54 and 55"). The plus paddle switch 54 is used for manual upshifting, and the minus paddle switch 55 is used for manual downshifting. The positive paddle switch 54 and the negative paddle switch 55 are connected to the TCU 40 , and switch signals of the paddle switches 54 and 55 output from the paddle switches 54 and 55 are read into the TCU 40 .

The TCU 40 includes a microprocessor that performs calculations, an EEPROM that stores programs for causing the microprocessor to execute various processes, a shift map (target gear ratio map), and the like, a RAM that stores various data such as calculation results, and a battery. It is configured with a backup RAM that retains memory contents, an input/output I/F, and the like.

When the automatic shift mode is selected, the TCU 40 follows the shift map and adjusts the operating conditions of the vehicle, such as throttle opening (or required torque) and vehicle speed (or input speed: engine speed, turbine speed). The gear ratio is automatically changed in a stepless manner. A shift map corresponding to the automatic shift mode is stored in the EEPROM within the TCU 40 . Here, FIG. 2 shows a shift characteristic diagram showing the relationship between the engine speed and the vehicle speed. In FIG. 2, the horizontal axis is the vehicle speed (km/h) and the vertical axis is the engine speed (rpm). Each of the eight solid lines indicates the relationship between the engine speed and the vehicle speed when the gear ratio is kept constant (that is, the gear ratio characteristics in the manual shift mode). In the automatic shift mode, any gear ratio between 1st (low) and 8th (overdrive) shown in FIG. automatically set according to On the other hand, when the manual shift mode is selected, the TCU 40 controls the gear ratio based on the shift operation accepted by the paddle switches 54,55.

In particular, the TCU 40 has a function to achieve both prevention of abnormal noise that may occur in a specific operating region, for example, an operating region in which transmission torque is large and shift speed is high, and drivability (shift speed). ing. Therefore, the TCU 40 functionally has a control parameter acquisition section 41 and a shift control section 42 . In the TCU 40, each function of the control parameter acquisition section 41 and the shift control section 42 is realized by executing the program stored in the EEPROM by the microprocessor.

The control parameter acquisition unit 41 acquires the output shaft rotation speed (vehicle speed) from the detection signal of the output shaft rotation speed sensor 58 . That is, the output shaft rotation speed sensor 58 and the control parameter acquisition section 41 function as vehicle speed detection means described in the claims. The vehicle speed may be obtained from wheel speed sensors attached to the wheels. In addition, the control parameter acquisition unit 41 acquires the gear ratio from the primary pulley rotation speed and the secondary pulley rotation speed (output shaft rotation speed). In other words, the control parameter acquiring section 41 also functions as gear ratio acquiring means described in the claims. Furthermore, the control parameter acquisition unit 41 reads the accelerator opening and the required torque transmitted from the ECU 60 via the CAN 100 . The acquired various control parameters are output to the shift control section 42 .

The shift control unit 42 sets a target gear ratio of the continuously variable transmission 30 based on the accelerator opening (or the required torque) and the vehicle speed (or the input rotation speed: engine rotation speed, turbine rotation speed), Control the gear ratio. That is, the shift control section 42 functions as shift control means described in the claims. In particular, the shift control unit 42 controls the change value (differential value , that is, the amount of change per unit time) and the change value of the gear ratio (differential value, that is, the amount of change per unit time). Also, when the change value (differential value) of the gear ratio is equal to or greater than the second threshold value, that is, when the abnormal noise generation determination condition is satisfied, the gear shift speed is targeted to become gentler than normal. Set the gear ratio. On the other hand, when the change value (differential value) of the required torque is less than the first threshold and/or when the change value (differential value) of the gear ratio is less than the second threshold, the shift control unit 42 sets the target transmission ratio so that the normal transmission speed is obtained.

Here, FIG. 3 shows a shift line (transition of the target gear ratio) during normal operation and a shift line (transition of the target gear ratio) when the abnormal noise generation determination condition is satisfied. The horizontal axis in FIG. 3 is time, and the vertical axis is gear ratio. In FIG. 3, the normal shift line (transition of the target gear ratio) is indicated by a dashed line, and the shift line (transition of the target gear ratio) when the abnormal noise generation determination condition is satisfied is indicated by a solid line. As shown in FIG. 3, when the abnormal noise generation determination condition is satisfied, the time during which the engine is held low (the time during which the speed is not changed) is longer than in the normal state (when the abnormal noise generation determination condition is not satisfied). is lengthened, and/or the slope (transmission speed) at which the gear ratio changes is moderated.

When setting the target gear ratio so that the shift speed becomes gentler, the shift control unit 42 determines that the relationship between the accelerator opening (or the required torque), the vehicle speed (or the engine speed), and the target gear ratio is A predetermined target gear ratio map is switched from a target gear ratio map for normal control to a noise prevention target gear ratio map in which a target gear ratio is set so as to make the gear shifting speed more gentle. Here, FIG. 4 shows an outline of the target gear ratio map for noise prevention. In FIG. 4, the horizontal axis is vehicle speed (km/h) (or engine speed (rpm)), and the vertical axis is accelerator opening (deg) (or required torque (Nm)). In the abnormal noise prevention target gear ratio map, a target gear ratio is given for each combination (lattice point) of accelerator opening (or required torque) and vehicle speed (or engine speed). In this abnormal noise prevention target gear ratio map, the target gear ratio is set so that the gear shift speed becomes gentler than in the target gear ratio map used normally. Note that the shift control unit 42 retrieves the noise prevention target gear ratio map based on the accelerator opening (or the required torque) and the vehicle speed (or the engine speed). A gear ratio is obtained.

However, when the vehicle speed is equal to or higher than a predetermined speed, that is, when road noise, engine noise, or the like increases and the sense of strangeness caused by the abnormal noise relatively decreases, the above-described abnormal noise generation determination condition is set. Even if this is satisfied, it is prohibited to set the target gear ratio so that the shift speed becomes gentler. Therefore, the transmission gear ratio is changed at the normal transmission speed.

Further, when the manual shift mode in which the gear ratio is changed according to the driver's manual shift operation is selected, that is, when it is preferable to prioritize securing the power performance required by the driver, the shift control unit 42 To prohibit setting a target gear ratio so as to make a gear shift speed more moderate even if an abnormal noise generation determination condition is satisfied. Therefore, the transmission gear ratio is changed at the normal transmission speed.

Note that the shift control unit 42 corrects (changes) the first threshold value and/or the second threshold value according to the oil temperature of the continuously variable transmission 30 (in consideration of the oil temperature). to) is preferred.

Next, the operation of the speed change control device 1 for the continuously variable transmission will be described with reference to FIG. FIG. 5 is a flowchart showing a processing procedure of shift control (abnormal noise prevention target gear ratio setting process) by the shift control device 1 for a continuously variable transmission. This process is repeatedly executed in the TCU 40 every predetermined time (for example, every 10 ms).

First, in step S100, the output shaft rotation speed (vehicle speed) is acquired from the detection signal of the output shaft rotation speed sensor 58. FIG. Also, the gear ratio is acquired from the primary pulley rotation speed and the secondary pulley rotation speed (output shaft rotation speed). Further, the accelerator opening and the required torque transmitted from the ECU 60 are read via the CAN 100 .

Next, in step S102, it is determined whether or not a manual shift mode is selected in which the gear ratio is changed according to the driver's manual shift operation. Here, when the manual shift mode is selected, the process proceeds to step S110. On the other hand, when the manual shift mode has not been selected, the process proceeds to step S104.

In step S104, it is determined whether or not the vehicle speed is equal to or higher than a predetermined speed. Here, when the vehicle speed is equal to or higher than the predetermined speed, the process proceeds to step S110. On the other hand, when the vehicle speed is less than the predetermined speed, the process proceeds to step S106.

In step S106, the change value of the required torque (differential value dT/dt) and the change value of the gear ratio (differential value di/dt) are calculated. Then, in subsequent step S108, it is determined whether or not the change value (differential value) of the required torque is equal to or greater than the first threshold value and the change value (differential value) of the gear ratio is equal to or greater than the second threshold value. , that is, it is determined whether or not the abnormal noise generation determination condition is satisfied. Here, if the change value (differential value) of the required torque is equal to or greater than the first threshold value and the change value (differential value) of the gear ratio is equal to or greater than the second threshold value, the process proceeds to step S112. migrates. On the other hand, when the change value (differential value) of the required torque is less than the first threshold value and/or when the change value (differential value) of the gear ratio is less than the second threshold value, the process proceeds to step S110. do.

In step S110, a normal target gear ratio map is selected, and the target gear ratio is set so as to achieve a normal shift speed. As a result, the gear ratio transitions as indicated by the dashed line in FIG. After that, the process exits.

On the other hand, if the abnormal noise occurrence determination condition is satisfied, in step S112, a noise prevention target gear ratio map is selected in which the target gear ratio is set so that the gear shift speed becomes gentler. The target gear ratio is set so that the shift speed becomes gentler. Therefore, the gear ratio transitions as indicated by the solid line in FIG. After that, the process exits.

As described in detail above, according to the present embodiment, the change value (differential value) of the required torque is equal to or greater than the first threshold value, and the change value (differential value) of the gear ratio is the second threshold value. The target gear ratio is set so that the shift speed becomes gentler when it is equal to or greater than the threshold value. Therefore, in an operating region where abnormal noise can occur (region where the change value of the required torque is large and the change value of the gear ratio is large), the gear shift speed is moderated, thereby preventing the occurrence of abnormal noise. . On the other hand, in the operating region where abnormal noise does not occur, the gear shifting speed is not moderated, that is, the gear shifting speed does not change, so deterioration of drivability can be suppressed. In particular, in this case, it is possible to further limit the conditions under which abnormal noise is generated, so that it is possible to further limit the operating range in which the shift speed is moderated. As a result, it is possible to achieve both prevention of abnormal noise that may occur in a specific driving range and drivability.

According to the present embodiment, in an operating region where abnormal noise may occur, a target gear ratio map that defines the relationship between accelerator operation amount (or required torque), vehicle speed (or engine speed), and target gear ratio However, since the target gear ratio map for normal control is switched to the noise prevention target gear ratio map that is set so that the gear shifting speed becomes gentler, the target gear ratio is set so that the gear shifting speed becomes gentler. can be set.

According to the present embodiment, in a region where the vehicle speed is high and road noise and the like are large (that is, a region where the sense of discomfort caused by abnormal noise is relatively low), even if the abnormal noise generation determination condition is satisfied, the gear shift speed is moderate. Since it is prohibited to set the target gear ratio so as to be , it is possible to avoid a decrease in the shift speed (that is, a deterioration in drivability).

Further, according to the present embodiment, when the manual shift mode is selected (that is, when it is preferable to prioritize securing the power performance required by the driver), it is assumed that the abnormal noise generation determination condition is satisfied. Also, since it is prohibited to set the target gear ratio in such a way that the shift speed becomes moderate, it is possible to avoid a decrease in the shift speed (that is, deterioration of drivability).

According to this embodiment, the first threshold value and/or the second threshold value are corrected (changed) according to the oil temperature of the continuously variable transmission 30 (in consideration of the oil temperature). ), the abnormal noise generation condition can be determined more appropriately.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible. For example, in the above embodiments, the present invention is applied to a chain-type continuously variable transmission (CVT), but instead of the chain-type continuously variable transmission, it is also applicable to, for example, a metal belt-type continuously variable transmission. can do.

Further, in the above embodiment, when the change value (differential value) of the required torque is equal to or greater than the first threshold value and the change value (differential value) of the gear ratio is equal to or greater than the second threshold value, the shift speed However, when the change value of the required torque is equal to or greater than the first threshold value, the target gear ratio is set so that the shift speed becomes gentler. may be Similarly, when the change value of the gear ratio is equal to or greater than the second threshold value, the target gear ratio may be set so that the shift speed becomes gentler.

In the above embodiment, the required torque is calculated on the ECU 60 side and received via the CAN 100, but it may be calculated on the TCU 40 side. Further, in the above embodiment, the TCU 40 that controls the continuously variable transmission 30 and the ECU 60 that controls the engine 10 are configured as separate pieces of hardware, but they may be configured as one piece of hardware.

1 Transmission Control Device for Continuously Variable Transmission 10 Engine 12 Crank Angle Sensor 20 Torque Converter 30 Continuously Variable Transmission 34 Primary Pulley 35 Secondary Pulley 36 Chain 40 TCU
41 Control parameter acquisition unit 42 Shift control unit 52 M range switch 54 Plus paddle switch 55 Minus paddle switch 56 Turbine speed sensor 57 Primary pulley speed sensor 58 Output shaft speed sensor 59 Range switch 60 ECU
62 accelerator pedal sensor 100 CAN

Claims (7)

accelerator operation amount detection means for detecting the amount of accelerator operation by the driver;
vehicle speed detection means for detecting the speed of the vehicle;
request torque acquisition means for acquiring a driver's request torque according to the accelerator operation amount;
a shift control means for setting a target gear ratio and controlling the gear ratio based on the accelerator operation amount or required torque and the speed or input speed of the vehicle;
The shift control means obtains a change value of the required torque, and if the change value of the required torque is equal to or greater than a first threshold value at which abnormal noise may be generated from the continuously variable transmission , the change value is less than the first threshold value. A gear change control device for a continuously variable transmission, characterized in that a target gear ratio is set so that the gear change speed becomes gentler than in the case of (1). a gear ratio acquiring means for acquiring a gear ratio of the continuously variable transmission;
accelerator operation amount detection means for detecting the amount of accelerator operation by the driver;
vehicle speed detection means for detecting the speed of the vehicle;
request torque acquisition means for acquiring a driver's request torque according to the accelerator operation amount;
a shift control means for setting a target gear ratio and controlling the gear ratio based on the accelerator operation amount or required torque and the speed or input speed of the vehicle;
The shift control means obtains a change value of the gear ratio, and if the change value of the gear ratio is equal to or larger than a second threshold value at which abnormal noise may be generated from the continuously variable transmission , the second threshold value A gear change control device for a continuously variable transmission, wherein a target gear ratio is set so that a gear change speed becomes gentler than in a case of less than. a gear ratio obtaining means for obtaining a gear ratio of the continuously variable transmission;
accelerator operation amount detection means for detecting the amount of accelerator operation by the driver;
vehicle speed detection means for detecting the speed of the vehicle;
request torque acquisition means for acquiring a driver's request torque in accordance with the accelerator operation amount;
a shift control means for setting a target gear ratio and controlling the gear ratio based on the accelerator operation amount or required torque and the speed or input speed of the vehicle;
the shift control means obtains a change value of the required torque and a change value of the gear ratio, and the change value of the required torque is equal to or greater than a first threshold value at which abnormal noise may be generated from the continuously variable transmission ; Further, the target gear ratio is set so that the speed change becomes gentler when the change in the gear ratio is equal to or greater than a second threshold at which abnormal noise may be generated from the continuously variable transmission. A gear control device for a continuously variable transmission. When setting the target gear ratio so that the gear shift speed becomes gentler, the gear shift control means sets a target in which the relationship between the accelerator operation amount or the required torque, the vehicle speed or the input rotation speed, and the target gear ratio is determined. 4. The gear ratio map according to any one of claims 1 to 3, characterized in that the target gear ratio map for normal control is switched to a target gear ratio map set so that the shift speed becomes gentler. A speed control device for a continuously variable transmission. The shift control means is characterized in that when the speed of the vehicle is equal to or higher than a predetermined speed, even if the judgment condition is satisfied, the target gear ratio is prohibited from being set so that the shift speed becomes gentler. A shift control device for a continuously variable transmission according to any one of claims 1 to 4. When a manual shift mode for changing the gear ratio in accordance with a manual gear shift operation by the driver is selected, the gear shift control means controls the target gear shift so that the gear shift speed becomes gentler even if the determination condition is satisfied. 6. A speed change control device for a continuously variable transmission according to claim 1, wherein setting of a ratio is prohibited. 7. The shift control means corrects the first threshold value and/or the second threshold value according to the oil temperature of the continuously variable transmission. 2. A speed change control device for a continuously variable transmission according to item 1.

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