JP2010007749A - Transmission controller of continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission controller of a continuously variable transmission improving acceleration feeling even when acceleration demanded by a driver is not high. <P>SOLUTION: The transmission controller comprises the continuously variable transmission continuously transmitting and outputting engine rotation speed and a control means which selects one mode between a normal transmission mode and a false stepped up-shift mode according to the magnitude of acceleration demanded by the driver and controls a transmission ratio of the continuously variable transmission based on the selected mode, wherein when the control means selects the false stepped up-shift mode and controls the speed change ratio, the more the demanded acceleration is low, the more it performs up-shift at a low engine rotation speed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In conventional transmission control of a continuously variable transmission, a shift pattern according to the vehicle speed and the amount of accelerator operation is stored as a map of the target input shaft rotation speed, and the target gear ratio is determined from the target input shaft rotation speed according to the driving state. It was.

  In such conventional shift control, when a kick down operation is performed to increase the accelerator operation amount suddenly with the intention of rapid acceleration, the target gear ratio is set so that the engine speed increases rapidly according to the accelerator operation amount. Is determined.

  When the accelerator operation amount is increased in this way, the speed ratio is set to the maximum to increase the engine rotation speed to the maximum area in the low vehicle speed area, and then gradually reduce the speed ratio to accelerate. Shift based on a simple map.

  However, when gear change control is performed by such a kick-down operation, the engine speed does not change, and only the vehicle speed increases, which gives the passenger a sense of incongruity and increases engine noise. There is a problem that occurs.

  When it is determined that sudden acceleration is required for such a problem, the engine speed is increased by controlling the gear ratio stepwise so that the vehicle speed increases while gradually increasing and decreasing the engine speed. A speed change control device for a continuously variable transmission that prevents an uncomfortable feeling that only the vehicle speed increases without running and prevents the generation of noise due to the engine speed being maintained in a high speed range for a long time (Patent Document) 1) is disclosed.

In this way, although it is a continuously variable transmission, as in the case of a stepped transmission, a speed change mode in which the engine rotation speed is increased and an upshift is performed in conjunction with the increase in the vehicle speed is referred to as “pseudo stepped up”. This is called “shift mode”.
JP-A-5-332426

  The technique disclosed in Patent Document 1 described above provides acceleration feeling by performing pseudo stepped upshift control in which the engine speed increases in conjunction with the increase in vehicle speed at the time of kickdown in which rapid acceleration is required. It is improving.

  However, in the invention disclosed in the cited document 1, since it is determined that the kick-down operation has been performed and the speed ratio is controlled, the control for repeatedly increasing and decreasing the speed ratio as described above is performed on the engine. This is done only when the rotation speed is high. Therefore, when the accelerator operation amount is not so large (for example, an intermediate opening), such a gear ratio control is not performed.

  However, even if the accelerator opening is an intermediate opening, an operating state in which only the vehicle speed increases without increasing the engine rotation speed during acceleration as shown in the map shown in FIG.

  Therefore, when the driver's acceleration request is small, as described above, a driving state occurs in which only the vehicle speed increases and the engine rotation speed does not change, and the driver feels uncomfortable and the acceleration feeling decreases. There was a problem to do.

  SUMMARY OF THE INVENTION The present invention has been made in view of such a problem. Even when the driver's acceleration request is not large, the speed change control device for a continuously variable transmission can improve the acceleration feeling and improve the fuel efficiency. The purpose is to provide.

  According to one embodiment of the present invention, a continuously variable transmission that continuously outputs and outputs an engine rotational speed, and a normal shift mode and a pseudo stepped upshift mode according to the magnitude of a driver's acceleration request. Control means for selecting one of the modes and controlling the transmission ratio of the continuously variable transmission based on the selected mode, and the control means selects the quasi-stepped upshift mode to control the transmission ratio. In this case, as the acceleration request is smaller, the upshift is performed at a lower engine speed.

  According to the present invention, when performing pseudo stepped upshift control, the engine speed is increased in association with the increase in vehicle speed by controlling the gear ratio to the upshift side at a lower engine rotation speed as the detected acceleration request is smaller. Since the traveling state in which the rotational speed increases repeatedly occurs, the acceleration feeling of the driver can be improved, and the engine rotational speed is prevented from becoming excessive, so that the fuel efficiency can be improved.

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

  In general, when a kickdown operation is performed to increase the accelerator operation amount suddenly with the intention of sudden acceleration from a steady running state with a relatively small accelerator operation amount at almost constant vehicle speed, it corresponds to the accelerator operation amount at this time It takes a certain amount of time for the actual gear ratio to reach the target gear ratio. Therefore, the driving force does not increase in spite of an increase in the engine speed immediately, and the engine is in a state of being blown in the meantime, which gives the driver a feeling of strangeness.

  As a countermeasure, it is conceivable to suppress a change in gear ratio when acceleration demand is large. For example, a technique (so-called linear mode) is known in which the gear ratio is fixed when the throttle opening exceeds a threshold value. Yes. In this way, by fixing the gear ratio before reaching a large gear ratio, the driving force is quickly increased in response to the increase in engine rotation speed, so the time from when the throttle increases until acceleration is obtained. The target delay is shortened.

  However, in such a method for determining the constant gear ratio, the throttle opening remains maintained at the constant gear ratio unless the throttle opening is returned from the threshold value and the hysteresis setting, and after the driver's initial acceleration intention is satisfied. However, since there is no change in the gear ratio, this will cause a sense of incongruity. In other words, in order to generate a gear ratio change, an operation of intentionally returning the accelerator pedal to a large degree is required.

  With respect to such problems, the applicant of the present invention aims to reliably provide an increase in the vehicle speed according to the driver's intention to accelerate at the time of kickdown acceleration regardless of increase in running resistance due to traction or the like. When the acceleration request is larger than a predetermined threshold, after downshifting to a downshift target gear ratio that is suppressed from the calculated target gear ratio, upshifting by the upshift target gear ratio based on the upshift gear characteristics Acceleration control means for performing acceleration, acceleration state determination means for determining an acceleration state after a downshift by the acceleration control means, and when the acceleration state is equal to or less than a preset value, the target gear ratio of the upshift is set to the acceleration state Control device for a continuously variable transmission (Japanese Patent Application No. 2002-329140) having an upshift target gear ratio correction means for correcting to the downshift side according to Later, it proposes a call) and the "prior invention".

  According to this prior invention, when the acceleration request is large (for example, at the time of kickdown acceleration), the downshift is performed at the downshift target speed ratio with the downshift speed characteristics suppressed more than the normal speed determined by the speed ratio determining means. After that, the upshift target speed ratio based on the upshift speed characteristics is upshifted to the lower side of the speed ratio, thereby suppressing an excessive increase in the engine speed during acceleration and a decrease in the vehicle acceleration, thereby reducing the vehicle acceleration. The vehicle acceleration according to the driver's intention to accelerate can be reliably obtained by balancing the rising and falling of the vehicle.

  When acceleration growth slows down after downshifting, the upshift target gear ratio is corrected to the downshift side according to the slowdown of acceleration, so even if the running resistance such as traction or climbing increases, it will always accelerate An acceleration feeling according to the intention can be obtained, and the drivability of a vehicle equipped with a continuously variable transmission can be greatly improved.

  By the way, in this prior invention, since the upshift is performed gradually after the downshift, the engine speed gradually converges to a substantially constant speed during the acceleration when the acceleration is prolonged.

  Further, even when the engine rotation speed at the time of determining kick-down is relatively high, during acceleration in the linear mode, the engine rotation speed gradually converges to a substantially constant speed during acceleration.

  Thus, in the acceleration state, the driver may feel uncomfortable due to the deterioration of the acceleration feeling due to the engine rotation speed not increasing despite the increase in the vehicle speed.

  Here, the above-described conventional technique performs a pseudo stepped upshift only when the acceleration request is high, and the pseudo stepped upshift is performed in a region where the acceleration request is not high (the accelerator opening is an intermediate opening). Absent. In order to solve this problem, if the area where the pseudo step-up shift is performed is simply expanded to an area where the acceleration request is not high, the following problem occurs.

  In other words, if the acceleration request is not high, there is no need to increase the engine rotation speed, but if the area is simply expanded, the engine rotation speed will rise to the high rotation speed area, and a pseudo step upshift will be performed. The driving force becomes excessive with respect to the acceleration request, and the fuel consumption is deteriorated by the excessive amount.

  Therefore, in the embodiment of the present invention, there is provided a control device for a continuously variable transmission that can improve acceleration feeling and improve fuel efficiency by performing control as described below.

<First Embodiment>
FIG. 1 is a block diagram centering on a control device for a continuously variable transmission for a vehicle according to a first embodiment of the present invention.

  The engine 11 is connected to a continuously variable transmission 10 including a torque converter 12.

  The engine 11 and the continuously variable transmission 10 include a controller 1 that controls the output of the engine 11 and the gear ratio of the continuously variable transmission 10 so as to be in an optimum driving state according to the traveling state. The continuously variable transmission mechanism of the continuously variable transmission 10 can employ a V-belt type or a toroidal type.

  The controller 1 performs fuel injection amount control, ignition timing control, and the like of the engine 11 according to the operating state. Further, the gear ratio of the continuously variable transmission 10 is controlled steplessly according to the driving state. Thereby, the rotational speed of the engine 11 is controlled. That is, the controller 1 is configured as a control unit that controls the continuously variable transmission based on the rotational speed of the engine.

  The controller 1 includes a throttle valve opening sensor 5 (throttle valve opening detecting means) that detects a throttle valve opening TVO based on an accelerator pedal operation, and a vehicle speed sensor that detects a vehicle traveling speed (hereinafter referred to as “vehicle speed VSP”). 4 (vehicle speed detection means), an engine rotation sensor 2 (engine rotation speed detection means) for detecting the engine rotation speed Ne of the engine 11, an input shaft rotation sensor 3 for detecting the input shaft rotation speed Nt of the continuously variable transmission 10, An output shaft rotational speed for detecting the output rotational speed OutRev of the step transmission 10 is connected. The controller 1 detects the driving state of the vehicle based on the values acquired from these sensors.

  The controller 1 is connected to a travel mode changeover switch 13. The travel mode change-over switch 13 is configured to be switchable in, for example, three stages (A, B, C), and is configured so that any one of the three stages can be selected by the driver.

  The controller 1 determines the travel mode based on the switching state of the travel mode switch 13. For example, when the travel mode switch 13 is switched to “A”, the travel mode is set to “sport mode”, and the engine speed Ne and the gear ratio are controlled to be higher than those in the normal mode. When the travel mode changeover switch 13 is switched to “C”, the travel mode is set to “eco mode” and the engine speed Ne and the gear ratio are controlled so that the fuel consumption rate is minimized. It should be noted that when the travel mode switch 13 is switched to “B”, the “normal mode” is set.

  The vehicle speed VSP is detected by, for example, detecting the output shaft rotational speed OutRev of the continuously variable transmission 10 and multiplying it by a constant (such as a tire radius) according to the final reduction ratio or the vehicle specification.

  Further, since the input shaft rotation speed Nt and the engine rotation speed Ne of the continuously variable transmission 10 can be regarded as the same when the torque converter 12 is in the lock-up state, in the control of this embodiment described below, the engine rotation speed A description will be given using Ne.

  Next, the operation of the control device for the continuously variable transmission according to the first embodiment of the present invention will be described.

  FIG. 2 is a flowchart of the shift control process according to the first embodiment of the present invention.

  The process of the flowchart shown in FIG. 2 is executed by the controller 1 at a predetermined cycle (for example, every several tens of msec).

  The control according to this flowchart is based on a control mode (hereinafter referred to as “normal transmission mode”) that variably controls the transmission ratio according to the driving state, and the speed of the vehicle as if it is a continuously variable transmission. The continuously variable transmission 10 is controlled while switching between a control mode (hereinafter referred to as “pseudo stepped upshift mode”) in which the engine speed is increased in conjunction with the increase and an upshift is performed.

  The controller 1 detects the throttle valve opening TVO, the vehicle speed VSP, the engine speed Ne, and the like based on the detection values from the sensors in the background, separately from the processing of this flowchart.

  First, the controller 1 acquires the current throttle valve opening TVO, vehicle speed VSP, and engine rotation speed Ne (S101).

  Next, based on the pseudo stepped upshift mode flag F, the controller 1 determines whether the current control mode is “normal shift mode” or “pseudo stepped upshift mode” (S102).

  When the pseudo stepped upshift mode flag F is set (the value of F is 1), it is determined that the control mode is the pseudo stepped upshift mode, and the process proceeds to step S110. If the pseudo stepped upshift mode flag F is not set (the value of F is 0), it is determined that the pseudo stepped upshift mode is not set, and the process proceeds to step S103.

  The pseudo stepped upshift mode flag F has an initial value of 0, and is set in the process of step S107 when it is determined that the control mode is the pseudo stepped upshift mode in the subsequent process of step S103. Is done.

  In step S103, based on each value acquired in step S101, it is determined whether the current control mode is the normal shift mode or the pseudo stepped upshift mode. When it is determined that the normal shift mode is set, the process proceeds to step S104. When it is determined that the pseudo stepped upshift mode is selected, the process proceeds to step S107.

  Specifically, the controller 1 determines that the throttle valve opening TVO is equal to or higher than a predetermined threshold (throttle valve opening threshold) and the throttle valve operating speed dTVO is equal to or higher than a predetermined threshold (throttle valve operating speed threshold). In some cases, it is determined that there is an acceleration request by the driver, and the pseudo stepped upshift mode is determined. The throttle valve operating speed dTVO is obtained by a differential value of the throttle valve opening TVO by unit time.

  These predetermined threshold values are threshold values for determining that there is an acceleration request from the driver. When the throttle valve opening TVO can be detected in eight stages, for example, an opening (2/8 or 3/8) of about two or three of the eight stages is set as the throttle valve opening threshold. Further, the throttle valve operating speed dTVO threshold is set to 60 [deg / s] in the stepping direction, for example.

  When the throttle valve opening TVO and the throttle valve operating speed dTVO are both below these thresholds, for example, it is determined that the driver is requesting traveling that matches the road load, and the normal shift mode is determined. . If it is determined that the transmission mode is the normal transmission mode, the process proceeds to step S104 to set the transmission ratio in the normal transmission mode.

  The speed ratio in the normal speed change mode is determined by a conventionally known method based on the throttle valve opening TVO, the vehicle speed VSP, and the engine speed Ne.

  As a specific example, similarly to the method described in the above-mentioned prior invention (Japanese Patent Application No. 2002-329140), the controller 1 determines the vehicle speed VSP and the accelerator operation amount (throttle valve opening TVO) based on the map. To obtain the corresponding target input shaft rotational speed (engine initial rotational speed Ne0). By setting the engine initial rotational speed Ne0, the gear ratio in the normal transmission mode is determined.

  Next, the controller 1 sets the set engine initial rotational speed Ne0 as a new target engine rotational speed tNe (S105).

  Next, the controller 1 shifts the continuously variable transmission 10 so that the engine rotational speed Ne matches the target engine rotational speed tNe (S106). After the process of step S106, the process according to this flowchart is temporarily terminated.

  If the throttle valve opening TVO and the throttle valve operating speed dTVO are both equal to or higher than these threshold values in the process of step S103 described above, it is determined that the driver has requested acceleration and the pseudo stepped upshift mode is determined. . If it is determined that the pseudo stepped upshift mode is selected, the process proceeds to step S107, and the controller 1 first sets the pseudo stepped upshift mode flag F to 1.

  Next, the controller 1 sets the downshift amount of the gear ratio so as to satisfy the driver's acceleration request (step S108).

  Specifically, the driver's intention to accelerate is obtained from a map from the throttle valve opening TVO and the throttle valve operating speed dTVO, as in the technique described in the above-mentioned prior invention. Then, the shift characteristic of the downshift corresponding to this acceleration intention is selected. Then, a change amount of the gear ratio for the downshift is obtained from the selected speed change characteristic according to the vehicle speed VSP.

  In the present embodiment, a new target engine speed tNe is calculated by calculating not the speed ratio change amount but the engine speed change amount ΔNe1 and adding this to the current target engine speed tNe. (S109).

  Then, based on the newly calculated target engine rotation speed tNe, shift control is performed in step S106. After the process of step S106, the process according to this flowchart is temporarily terminated.

  Note that the acceleration control by the first downshift performed after the transition to the pseudo stepped upshift mode by the processing in steps S108, S109, and S106 is referred to as "initial acceleration". With this initial acceleration, first, downshift control is performed so as to respond to the driver's acceleration request. In step S112, which will be described later, until the engine rotation speed Ne reaches the upshift determination rotation speed, acceleration control is performed in step S113 and S114 while suppressing the change in the gear ratio, and the vehicle is accelerated. The process from the initial acceleration to the acceleration control that suppresses the change in the gear ratio is called “linear shift”.

  If it is determined in the process of step S102 described above that the control mode is the pseudo stepped upshift mode, in step S110, the controller 1 determines whether or not the pseudo stepped upshift mode is continued.

  In this flowchart, if it is first determined in step S103 to shift to the pseudo stepped upshift mode, the pseudo stepped upshift mode flag is set in step S107. In the subsequent processing, it is determined in step S102 that the pseudo stepped upshift mode flag is set, and the process proceeds to S110. The process of shifting from step S102 to step S110 is continued until the end of the pseudo stepped upshift mode is determined and the pseudo stepped upshift mode flag is reset.

  More specifically, in step S110, the controller 1 determines that the throttle valve opening TVO is less than a predetermined threshold (second throttle valve opening threshold) or the throttle valve operating speed dTVO is a predetermined threshold. If it is equal to or greater than (second throttle valve operation speed threshold), it is determined that the driver's request for acceleration has ended and the pseudo stepped upshift mode has ended. If it is not the end of the pseudo stepped upshift mode, it is determined that the pseudo stepped upshift mode is continued.

  The throttle valve opening TVO is set to the same value as step S103 described above, that is, for example, an opening (2/8 or 3/8) of about 2 or 3 out of 8 stages is used as the second throttle valve opening threshold. . Also, the second throttle valve operation speed threshold is set to 60 [deg / s] in the step-back direction (or -60 [deg / s] in the step-down direction), for example.

  When the throttle valve opening degree TVO or the throttle valve operating speed dTVO satisfies these threshold values, the controller 1 determines that the pseudo stepped upshift mode has ended, and proceeds to step S117. If it is determined that the pseudo stepped upshift mode has not ended (the pseudo stepped upshift mode continues), the process proceeds to step S111.

  In step S111, first, an upshift determination rotational speed is set.

  The upshift determination rotational speed is a value that can determine at what timing the upshift is performed after the shift control is performed based on the downshift set in step S108 described above.

  The controller 1 refers to the upshift determination rotational speed map illustrated in FIG. 3 from the throttle valve opening TVO acquired in step S101 and the current vehicle speed VSP, and acquires the upshift determination rotational speed.

  As will be described later with reference to FIG. 3, the upshift determination rotational speed map is set such that the smaller the driver's acceleration request, the lower the upshift determination rotational speed. Further, the upshift determination rotational speed can be changed according to the travel mode selected by the travel mode switch 13.

  Next, the controller 1 compares the engine rotation speed Ne acquired in step S101 with the upshift determination rotation speed acquired in step S111, and determines whether or not the engine rotation speed Ne has exceeded the upshift determination rotation speed. (S112).

  When the engine rotational speed Ne is equal to or lower than the upshift determination rotational speed, the process proceeds to step S113. If the engine rotation speed Ne exceeds the upshift determination rotation speed, the process proceeds to step S115.

  In step S113, a change amount of the gear ratio in the linear shift is set.

  Specifically, after the above-described initial acceleration, the shift control is performed while suppressing the amount of change in the gear ratio.

  In this control, the controller 1 obtains the driver's intention to accelerate from the throttle valve opening TVO and the throttle valve operating speed dTVO in the same manner as the technique described in the preceding invention. Then, the shift characteristic of the upshift corresponding to this acceleration intention is selected. Then, the amount of change in the gear ratio in the upshift is obtained from the selected speed change characteristic according to the vehicle speed VSP.

  At this time, as in the preceding invention, the control may be gradually performed to the upshift side corresponding to the increase in the vehicle speed, or may be controlled to the downshift side when the driving force is insufficient. Thus, by controlling so as to suppress the change in the gear ratio, the engine rotation speed Ne increases in conjunction with the increase in the vehicle speed VSP, and the acceleration feeling can be improved.

  In the present embodiment, a new target engine speed tNe is calculated by calculating the engine speed change amount ΔNe2, not the speed ratio change amount, and adding this to the current target engine speed tNe. (S114).

  Then, based on the newly calculated target engine rotation speed tNe, shift control is performed in step S106. After the process of step S106, the process according to this flowchart is temporarily terminated.

  As described above, after the controller 1 determines that the pseudo stepped upshift mode is used, the engine rotational speed is increased by performing control so as to suppress the change in the gear ratio in the linear shift.

  If the engine rotational speed Ne exceeds the upshift determination rotational speed in step S112 described above, the process proceeds to step S115, and the controller 1 performs upshift control.

  Specifically, the controller 1 sets an engine rotation speed change amount ΔNe3 corresponding to the upshift amount. The amount of change ΔNe3 is set so that the newly set target engine speed tNe is higher than the target engine speed tNe set at the time of the first downshift control determined as the pseudo stepped upshift mode. Is set. That is, the controller 1 sets the new target engine speed tNe, which is a value obtained by subtracting the amount of change ΔNe3 from the engine initial speed Ne0, to the target set at the time of the first downshift control that is determined to be the pseudo stepped upshift mode. ΔNe3 is set so as to be a value higher than the engine speed tNe.

  Similarly, the amount of change ΔNe3 set thereafter is set to be higher than the target engine speed tNe that is newly calculated from the target engine speed tNe at the time of upshift control set in the previous step S114. The

  The vehicle speed VSP is higher than that after the previous upshift by the shift control according to the acceleration request by the driver. Therefore, the running resistance (for example, air resistance and the internal resistance of the continuously variable transmission 10 and the engine 11) is increased by the increase in the vehicle speed VSP. Therefore, the controller 1 sets, as ΔNe3, a value obtained by correcting the target engine speed tNe at the time of the previous upshift so as to be higher by the driving force deficiency due to the increase in travel resistance.

  By performing the upshift control in this manner, the engine speed is temporarily reduced. Thereby, an acceleration feeling like an upshift of the stepped transmission can be given to the driver.

  Next, the controller 1 calculates a new target engine rotational speed tNe having a downshift characteristic by subtracting the set ΔNe3 from the current target engine rotational speed tNe (S116).

  Based on the newly calculated target engine speed tNe, the controller 1 performs shift control in step S106. After the process of step S106, the process according to this flowchart is temporarily terminated.

  Thus, after the controller 1 suppresses the change in the gear ratio and increases the engine rotational speed Ne, the controller 1 controls the gear ratio to the upshift side to decrease the engine rotational speed Ne. This is called “shift shifting”. This step upshift is repeatedly performed under the control of steps S110 to S116 while the acceleration request is continued (while the pseudo stepped upshift mode is continued).

  If it is determined in step S110 that the pseudo stepped upshift mode has ended, the process proceeds to step S117, and the controller 1 resets the pseudo stepped upshift mode flag F (sets the value of F to 0). .

  After resetting the pseudo stepped upshift mode flag F, the controller 1 sets the gear ratio in the normal speed change mode and sets the engine initial rotational speed Ne0 in the same manner as in step S104 described above (S118).

  Then, the controller 1 sets the set engine initial rotational speed Ne0 as the target engine rotational speed tNe (S119).

  Then, based on the newly calculated target engine speed tNe, shift control is performed in step S106. After the process of step S106, the process according to this flowchart is temporarily terminated.

  Through the above processing, shift control based on the driver's acceleration request is performed.

  FIG. 3 is an explanatory diagram of an example of the above-described upshift determination rotation speed map.

  The upshift determination rotational speed map illustrated in FIG. 3 is a map in which the correspondence between the vehicle speed VSP and the engine rotational speed Ne is set for each throttle valve opening TVO.

  The throttle valve opening TVO is set so as to be detected in eight stages as described above. In the example shown in FIG. 3, the correspondence between the vehicle speed VSP and the engine rotational speed Ne for each of the six stages of throttle valve opening TVO from 3/8 to 8/8, which is the determination condition of the pseudo stepped upshift mode. The relationship is shown.

  According to the upshift determination rotational speed map, the lower the throttle valve opening TVO, that is, the smaller the acceleration request from the driver, the lower the upshift determination rotational speed is selected, and the upshift control is performed at a lower engine rotational speed Ne. Is set to be done.

  When the travel mode is changed by the travel mode switch 13, the value of the upshift determination rotational speed may be changed corresponding to the travel mode. Specifically, when the sports mode is selected, the driver's request for acceleration is higher, so the upshift determination rotational speed is corrected to the larger side. On the other hand, when the eco mode is selected, since the fuel efficiency is given priority over the driver's acceleration request, the upshift determination rotational speed is corrected to the small side. Thus, the magnitude of the driver's acceleration request can also be determined based on other than the throttle valve opening TVO and the vehicle speed.

  Next, the operation of this embodiment will be described.

  FIG. 4 is a time chart of this embodiment.

  This time chart shows the throttle valve opening TVO, the pseudo stepped upshift mode determination flag F, the engine rotation speed Ne, the vehicle speed VSP, and the vehicle acceleration G from the upper side in the time axis from the left to the right. , Showing each state.

  First, the vehicle is traveling in the normal shift mode. In other words, in this state, the throttle valve opening TVO and the throttle valve operating speed dTVO are small enough not to satisfy the criteria for the pseudo stepped upshift mode.

  Here, when the throttle valve opening TVO is operated by the driver, the determination criterion in step S103 of the flowchart of FIG. 2 is satisfied, and it is determined that the controller 1 has shifted to the pseudo stepped upshift mode (timing A In step S109, the target engine speed tNe for initial acceleration is set. By this initial acceleration, the vehicle speed VSP is gradually accelerated. Further, the vehicle acceleration G derived from the inclination of the vehicle speed VSP also increases.

  After this initial acceleration, it is determined in step S112 in FIG. 2 whether or not the engine rotation speed has exceeded the upshift determination rotation speed. When the engine rotation speed is less than the upshift determination rotation speed, the gear shift control at the gear ratio set in step S113 is performed in the linear shift (timing B).

  If the engine rotation speed Ne increases and is determined to be equal to or higher than the upshift determination rotation speed (timing C), an upshift amount is set in step S115, and shift control based on the upshift amount is performed. . The target engine speed tNe at this time is set to a value that takes into account the increase in travel resistance compared to the initial target engine speed tNe (timing B) when the pseudo stepped upshift mode is entered.

  By executing this step-up shift shift, the target engine speed tNe is temporarily lowered. However, the actual engine speed Ne is also increased along with the subsequent increase in the vehicle speed VSP, and the acceleration G is also drawn in a correspondingly upward graph.

  As described above, the engine rotational speed Ne increases in conjunction with the increase in the vehicle speed VSP, and the acceleration G increases accordingly, thereby improving the acceleration feeling.

  After that, when it is determined that the target engine speed tNe has increased again and reached the upshift determination rotational speed (timing D), the upshift is performed again in step S115. The upshift control at this time is set to a value slightly higher than the target engine speed tNe (timing C) at the time of the previous upshift control, taking into account the increase in running resistance. As described above, in the step-up upshift, the control to the upshift is repeatedly performed.

  In this way, in the quasi stepped upshift mode, the stepwise upshift is performed after the linear shift, so that the state in which the engine rotational speed Ne increases in conjunction with the increase in the vehicle speed VSP is continuously performed. Feeling can be improved.

  FIG. 5 is an explanatory diagram showing a relationship among the engine speed Ne, the engine torque, the fuel consumption rate, and the output horsepower in the gear ratio control according to the present embodiment.

  In the diagram shown in FIG. 5, the equal fuel consumption rate is indicated by a solid line corresponding to the engine speed Ne and the engine torque, and the center portion of the contour line is the driving condition with the best fuel consumption. . Further, corresponding to the engine rotation speed Ne and the engine torque, the equal horsepower line of the engine 11 is shown by a dotted line.

  In the present embodiment, in steps S111 and S112 in FIG. 2, when the engine rotational speed Ne exceeds the upshift determination rotational speed, an upshift is performed and the engine rotational speed Ne is controlled to decrease.

  By controlling in this way, an increase in the engine speed Ne can be suppressed, an appropriate engine output corresponding to the throttle valve opening TVO can be achieved, and the operation can be continued near the optimum fuel consumption conditions. .

  More specifically, after the initial acceleration after shifting to the quasi stepped upshift mode, the route indicated by line A in FIG. 5 is followed. Thereafter, when an upshift is performed, the engine rotational speed Ne decreases, and a path such as the line B in FIG. 5 is obtained. When the upshift is performed again, a path like the line C in FIG. 5 is obtained.

  As described above, since the engine rotational speed Ne is not increased more than necessary than the step-up shift shift, it is possible to always use a region where both the engine torque and the fuel consumption rate are efficient.

  FIG. 6 is an explanatory diagram showing the relationship between the engine rotational speed Ne and the output horsepower in the gear ratio control according to the present embodiment.

  The output horsepower of the engine 11 has a characteristic line with respect to the engine rotation speed Ne for each throttle valve opening TVO.

  Usually, the peak of output horsepower is in the vicinity of a predetermined engine speed Ne (indicated by a dotted line in the figure). For example, when the engine speed is around 4000 to 6000 [rpm], the output horsepower peak. By bringing the operating state of the engine 11 close to the peak of the output horsepower, the efficiency of the power performance of the engine 11 becomes the highest.

  In the present embodiment, when the engine speed Ne exceeds the upshift determination rotational speed determined for each throttle valve opening TVO, an upshift is performed and the engine rotational speed Ne is controlled to decrease. As a result, an increase in the engine rotational speed Ne is suppressed, and the operation can be continued in a region where the power performance efficiency of the engine 11 is high.

  More specifically, after the initial acceleration after shifting to the pseudo stepped upshift mode, the route indicated by line A in FIG. 6 is followed. Thereafter, when an upshift is performed, the engine rotational speed Ne decreases, and a path such as the line B in FIG. 6 is obtained. When the upshift is performed again, a route like the line C in FIG. 6 is obtained.

  Thus, since the engine rotational speed Ne is not increased, a state where the engine output horsepower is high can be maintained, and a region where the engine power performance is always efficient can be used.

  As described above, in the first embodiment of the present invention, when there is a request for acceleration, the process shifts to the pseudo stepped upshift mode, first performs a downshift in a linear shift, performs an initial acceleration, and then performs a shift. Control that suppresses the change in the ratio is executed to reduce noise and an uncomfortable feeling to the driver due to an increase in the engine rotation speed.

  Thereafter, when the engine rotation speed Ne exceeds the upshift determination rotation speed set in step S111, by performing the upshift control, the engine rotation speed Ne once decreased increases again as the vehicle speed VSP increases. Acceleration feeling can be improved.

  Further, since this upshift control is repeatedly performed (stepped upshift), it is possible to always perform control so that the engine speed Ne does not increase excessively, and by using a region where the engine efficiency is high even during acceleration, Fuel consumption can be improved.

  Further, since the upshift control is performed at a lower engine speed Ne as the driver's acceleration request is smaller, the engine speed Ne is not increased even when the acceleration request is small, and fuel consumption is prevented from deteriorating. Can do.

Second Embodiment
Next, a second embodiment will be described.

  The second embodiment of the present invention differs from the first embodiment described above in terms of upshift determination criteria. Since the basic configuration is the same as that of the first embodiment, the description thereof is omitted.

  The shift control process of the second embodiment is substantially the same as the flowchart of the shift control process of the first embodiment shown in FIG. 2, but the upshift determination (steps S111 and S112) is different. This difference will be described.

  If it is determined in step S110 of FIG. 2 that the pseudo stepped upshift mode has not ended, the controller 1 starts counting up the timer (corresponding to step S111).

  Next, the controller 1 determines whether or not the timer value has expired the upshift determination rotational speed timer value (corresponding to step S112). When the timer value is less than the upshift determination rotation speed timer value, the process proceeds to step S113. When the timer value expires the upshift determination rotational speed timer value, the timer value is once cleared and the process proceeds to step S115. Then, upshift control is performed as in the first embodiment.

  Thereafter, the timer value starts to be counted up again in the process corresponding to step S111.

  As described above, in the first embodiment, after the execution of the linear shift, the upshift shift is performed step by step when the engine rotation speed Ne exceeds the upshift determination rotation speed.

  On the other hand, in the second embodiment, after a predetermined time has elapsed after the execution of the linear shift (after the upshift determination rotational speed timer value has expired), the upshift is performed step by step.

  Thus, by performing upshift control at predetermined time intervals, upshifts are periodically performed in the pseudo stepped upshift mode, and driver drivability is not impaired.

  The upshift determination rotation speed timer value of the present embodiment may be a unique value, for example, but may be changed according to the driver's acceleration request.

  FIG. 7 is an explanatory diagram illustrating an example of a map of upshift determination rotation speed timer values according to the second embodiment.

  The map shown in FIG. 7 shows the relationship among the vehicle speed VSP, the throttle valve opening TVO, and the upshift determination rotational speed timer value.

  Specifically, when at least one of the vehicle speed VSP and the throttle valve opening TVO is small, the upshift determination rotational speed timer value is set small.

  By setting the upshift determination rotational speed timer value in this manner, when the acceleration request by the driver is small or the vehicle speed is low, the upshift determination rotational speed timer value is set small, thereby gradually increasing the upshift speed change. The upshift interval is reduced, and upshift control is performed at a lower engine speed Ne.

  As in the first embodiment described above, when the travel mode is changed by the travel mode switch 13, the upshift determination rotational speed timer value may be changed corresponding to the travel mode.

  Next, the operation of this embodiment will be described.

  FIG. 8 is a time chart of this embodiment.

  This time chart shows the time from the left to the right for the throttle valve opening TVO, the pseudo stepped upshift mode determination flag F, the timer value, the engine speed Ne, the vehicle speed VSP, and the vehicle acceleration G from the top of the figure. Each state on the axis is shown.

  First, the vehicle is traveling in the normal shift mode. In other words, in this state, the throttle valve opening TVO and the throttle valve operating speed dTVO are small enough not to satisfy the criteria for the pseudo stepped upshift mode.

  Here, when the throttle valve opening TVO is operated by the driver, the determination criteria in step S103 of the flowchart of FIG. 2 are satisfied, and the controller 1 has shifted to the pseudo stepped upshift mode, as in the first embodiment. If it is determined (timing A), the target engine speed tNe for initial acceleration is set in step S109. By this initial acceleration, the vehicle speed VSP is gradually accelerated. Further, the vehicle acceleration G derived from the inclination of the vehicle speed VSP also increases.

  After this initial acceleration, the timer value starts to be counted up in a process corresponding to step S111 in FIG. Then, in a process corresponding to step S112 in FIG. 2, it is determined whether or not this timer value has expired the upshift determination rotational speed timer value. If the upshift determination rotational speed timer value is not reached, first, the shift control set in step S113 is performed (timing B).

  If the timer value counts up and it is determined that the upshift determination rotational speed timer value has expired (timing C), an upshift amount is set in step S115, and a shift based on the upshift amount is performed. Control is made. The target engine rotational speed tNe at this time is set to a value that takes into account the increase in travel resistance compared to the initial target engine rotational speed tNe (timing B) at the time of linear shift execution.

  By this upshift, the target engine speed tNe is temporarily lowered, but the actual engine speed Ne is also increased along with the subsequent increase of the vehicle speed VSP, and the acceleration G is also drawn to the right correspondingly.

  As described above, the engine rotational speed Ne increases in conjunction with the increase in the vehicle speed VSP, and the acceleration G increases accordingly, thereby improving the acceleration feeling.

  Thereafter, the timer value is counted up again, and when it is determined that the upshift determination rotational speed timer value has expired again (timing D), the upshift is performed again in step S115. The upshift control at this time is set to a value slightly higher than the target engine speed tNe (timing C) at the time of the previous upshift control, taking into account the increase in running resistance.

  In this way, by performing the upshift, the state in which the engine rotation speed Ne increases in conjunction with the increase in the vehicle speed VSP is continuously performed, and the acceleration feeling can be improved.

  As described above, in the second embodiment of the present invention, similarly to the first embodiment described above, when there is an acceleration request, the process shifts to the quasi stepped upshift mode, and first in the linear shift control, After downshifting and initial acceleration, control to suppress the gear ratio is executed to reduce noise and discomfort to the driver due to increase in engine speed.

  After that, when the timer value expires the upshift determination rotation speed timer value, the acceleration feeling is caused by increasing the engine rotation speed Ne once decreased along with the increase in the vehicle speed VSP by executing the upshift shift step by step. Can be improved.

  Further, since this upshift control is repeatedly performed by counting up the timer value, it is possible to perform control so that the engine rotational speed Ne does not always increase, and by using a region where the engine efficiency is high even during acceleration, fuel consumption can be reduced. Can be improved.

  Further, the smaller the driver's acceleration request is, the smaller the value of the upshift determination rotational speed timer value is. As a result, the engine rotational speed Ne for performing the next upshift control becomes low, and the engine is reduced when the acceleration request is small. It is possible to prevent the fuel efficiency from deteriorating without increasing the rotational speed Ne.

  Furthermore, in the second embodiment, since the upshift timing of the step-up shift is regular, it is easy for the driver to grasp the rhythm of the shift, and the drivability can be improved as well as the acceleration feeling is improved. In addition, it is possible to further reduce discomfort to the driver.

<Third Embodiment>
Next, a third embodiment will be described.

  The third embodiment of the present invention differs from the first embodiment described above in the process for upshift determination. Since the basic configuration is the same as that of the first embodiment, the description thereof is omitted.

  The shift control process of the third embodiment is almost the same as the flowchart of the shift control process of the first embodiment shown in FIG. 2, but the process (steps S111 and S112) at the time of upshift determination is different. This difference will be described.

  First, in step S111 of FIG. 2 described above, the controller 1 refers to the upshift determination rotation speed map from the throttle valve opening TVO and the vehicle speed VSP, and acquires the upshift determination rotation speed.

  Next, the controller 1 executes the following process in the process corresponding to step S112 described above.

  First, the controller 1 compares the engine rotation speed Ne with the upshift determination rotation speed to determine whether or not the engine rotation speed Ne has exceeded the upshift determination rotation speed. When the engine rotational speed Ne is equal to or lower than the upshift determination rotational speed, the process proceeds to step S113.

  On the other hand, when it is determined that the engine rotational speed Ne has exceeded the upshift determination rotational speed, the controller 1 sets the target engine rotational speed tNe that can be set when the upshift control is to be performed and the current engine rotational speed Ne. It is further determined whether or not the difference value is greater than or equal to a predetermined value.

  This process will be specifically described.

  The controller 1 performs control so that the engine rotational speed Ne does not decrease more than necessary when performing a shift to the Hi side (upshift) in the step-up shift shift. This is to prevent the output shaft torque of the continuously variable transmission 10 from decreasing with a decrease in the engine rotational speed Ne.

  Specifically, the controller 1 sets a Hi side limit line, and performs control so that the target engine speed tNe does not fall below the Hi side limit line.

  The Hi-side limit line is set by the controller 1 based on the vehicle speed VSP, the uphill slope, the turning angle during cornering, and the like. For example, when the vehicle speed VSP is high, the running resistance increases, so the Hi side limit line is set high to resist this. Also, when the uphill slope is large, the running resistance increases due to the uphill resistance, so the Hi-side limit line is similarly set high. In addition, when the corner turning angle is large (that is, when the steering angle is large), running resistance is generated due to turning of the wheel, and rising acceleration after corner running is required. Set high.

  The controller 1 has in advance maps, functions, and the like corresponding to the vehicle speed VSP, the uphill slope, and the steering angle, and sets the Hi-side limit line based on these detected values. The uphill slope may be calculated from the difference in torque between the front and rear axles, or the vehicle may be provided with a sensor that detects the slope, or the slope may be detected from the road conditions at the current position acquired by GPS. Good. Further, as the corner turning angle, the steering angle of the steering wheel may be acquired, or the turning angle may be acquired from the road condition of the current position acquired by GPS.

  When it is determined in step S112 that the engine rotation speed Ne has exceeded the upshift determination rotation speed, the controller 1 performs the downshift control by the same process as the process executed in steps S115 and S116. A target engine speed tNe that can be set is calculated.

  Then, it is determined whether or not a difference value dNe between the calculated target engine speed tNe and the engine speed Ne corresponding to the Hi side limit line is equal to or greater than a predetermined value. If it is determined that the difference value dNe is less than the predetermined value, the process proceeds to step S113 without proceeding to step S115.

  That is, even when the engine rotational speed Ne exceeds the upshift determination rotational speed, if the difference value dNe is smaller than a predetermined value, the controller 1 does not perform an upshift at that time, and performs a pseudo stepped upshift. Continue control while suppressing the gear ratio by mode.

  On the other hand, when it is determined that the difference value dNe is equal to or greater than the predetermined value, the process proceeds to step S115, and the upshift control is performed as described above.

  By such control, when the upshift control is restricted by the Hi-side limit line and the amount of upshift becomes excessive, the shift timing can be delayed to achieve sufficient upshift control.

  Note that the predetermined value used as a criterion for determining the difference value dNe is a value that can be appropriately determined so that the amount of upshift is appropriate. That is, the shift control is performed by the upshift control so that the amount of upshift is given to give the driver an acceleration feeling like a shift change of the stepped transmission, and the interval of the upshift control is shortened. It is preferable to set a predetermined value so as not to be complicated.

  FIG. 9 is a time chart showing only the portion related to the engine rotational speed Ne of the third embodiment.

  First, the vehicle is traveling in the normal shift mode. In other words, in this state, the throttle valve opening TVO and the throttle valve operating speed dTVO are small enough not to satisfy the criteria for the pseudo stepped upshift mode.

  Here, when the throttle valve opening TVO is operated by the driver, the determination criteria in step S103 of the flowchart of FIG. 2 are satisfied, and the controller 1 has shifted to the pseudo stepped upshift mode, as in the first embodiment. If it is determined (timing A), the target engine speed tNe for initial acceleration is set in step S109, and acceleration is started.

  After this initial acceleration, it is determined whether or not the engine rotational speed Ne has exceeded the upshift determination rotational speed by the same processing as step S112 in FIG. Further, it is determined whether or not a difference value dNe between the target engine speed tNe and the engine speed Ne corresponding to the Hi side limit line is below a predetermined value.

  When the engine rotational speed Ne is less than the upshift determination rotational speed, first, the shift control set in step S113 is performed (timing B).

  When it is determined that the engine rotational speed Ne is equal to or higher than the upshift determination rotational speed and the difference value dNe exceeds a predetermined value (timing C), an upshift amount is set in step S115. Shift control based on the shift amount is performed. As described above, the target engine speed tNe at this time is set to a value that takes into account the increase in running resistance, compared to the initial target engine speed tNe (timing B) at the time of shifting to the pseudo stepped upshift mode. The

  Thereafter, when the target engine speed tNe increases and the vehicle speed VSP also increases, the Hi-side limit line also increases.

  Here, when the engine rotational speed Ne again becomes equal to or higher than the upshift determination rotational speed, when it is determined that the difference value dNe is below a predetermined value (timing D), the controller 1 performs upshift control. Instead, the control in which the change in the gear ratio in the linear shift is suppressed is continued by the processing in steps S113 and S114.

  Then, in the process corresponding to step S112, the determination as to whether or not the difference value dNe exceeds a predetermined value is repeated. When it is determined that the difference value dNe exceeds the predetermined value (timing E), the process proceeds to step S115. Shift control to upshift is performed.

  In this way, by performing the upshifting step by step, a state in which the engine rotation speed Ne increases continuously in conjunction with the increase in the vehicle speed VSP can improve the acceleration feeling.

  As described above, in the third embodiment of the present invention, it is possible to obtain the same effect as that of the first embodiment described above.

  As a feature of the third embodiment, for example, when the vehicle speed VSP is high and the Hi-side limit line is increasing, the upshift amount of the upshift is not reduced step by step, and the acceleration feeling is reduced. It can be prevented from decreasing.

  In addition, when the amount of upshift is not sufficient due to restriction by the Hi side limit line, the interval until the next upshift control becomes small, and a small amount of upshift occurs in a short period of time. This may give the driver an uncomfortable feeling like hunting.

  In the third embodiment, such a sense of incongruity to the driver can be prevented, and the acceleration feeling can be improved.

  In the third embodiment, the Hi-side limit line is determined together with the determination of the upshift determination rotational speed as in the first embodiment, but the upshift determination rotational speed timer value is determined as in the second embodiment. It may be configured such that the Hi-side limit line is determined at the expiration determination.

It is a block diagram centering on the continuously variable transmission of 1st Embodiment of this invention. It is a flowchart of the shift control of 1st Embodiment of this invention. It is explanatory drawing of an example of the upshift determination rotational speed map of 1st Embodiment of this invention. It is a time chart in the linear shift of 1st Embodiment of this invention. It is explanatory drawing which shows the relationship between the engine speed of the 1st Embodiment of this invention, an engine torque, a fuel consumption rate, and an output horsepower. It is explanatory drawing which shows the relationship between the engine speed of 1st Embodiment of this invention, and output horsepower. It is explanatory drawing of an example of the map of the upshift determination rotational speed timer value of the 2nd Embodiment of this invention. It is a time chart in the linear shift of the 2nd Embodiment of this invention. It is a time chart in the linear shift of the 3rd Embodiment of this invention.

Explanation of symbols

1 controller 2 engine rotation sensor 3 input shaft rotation sensor 4 vehicle speed sensor 5 throttle valve opening sensor 10 continuously variable transmission 11 engine 12 torque converter 13 travel mode changeover switch

Claims (5)

A continuously variable transmission that continuously outputs and outputs an engine rotation speed;
Control means for selecting one of the normal transmission mode and the quasi-stepped upshift mode according to the magnitude of the driver's acceleration request and controlling the transmission ratio of the continuously variable transmission based on the selected mode When,
With
When the control means selects the pseudo stepped upshift mode and controls the gear ratio, the control means performs the upshift at a lower engine speed as the acceleration request is smaller. . The control means includes
The smaller the acceleration request, the lower the upshift determination rotational speed is set,
2. When the pseudo stepped upshift mode is selected to control a gear ratio, an upshift is performed when a current engine rotational speed reaches the set upshift determination rotational speed. A control device for a continuously variable transmission according to claim 1.   The control device for a continuously variable transmission according to claim 1, wherein the control means performs upshift at a predetermined time interval when the pseudo geared upshift mode is selected and the gear ratio is controlled.   4. The continuously variable transmission control apparatus according to claim 3, wherein the control means sets the predetermined time to be smaller as the acceleration request is smaller.   When the control means selects the pseudo stepped upshift mode and controls the gear ratio, a difference value between a current engine speed and an engine speed that can be taken when an upshift is performed is a predetermined value. The control device for a continuously variable transmission according to any one of claims 1 to 4, wherein an upshift is performed when the value exceeds.