JP2006266288A - Variable speed control of continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reacceleration performance after operation by releasing an accelerator in a vehicle provided with a continuously variable transmission. <P>SOLUTION: Values equivalent to demand torque of a driver (amount of accelerator operation, opening of throttle) are detected and recorded (S1), and a coast line on a higher rotational speed side than a usual coast line corresponding to zero of a value equivalent to demand torque stored in a speed change map is set in accordance with the recorded value equivalent to demand torque when the value equivalent to demand torque becomes zero to change speed to the set coast line on a high rotational speed side (S7, S10). Since rotational speed of an engine is high when compared with change speed to the usual coast line during coast running and a speed change ratio is maintained on a low side, satisfactory acceleration performance is achieved when stepping on an accelerator pedal for reacceleration after that. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to shift control of a continuously variable transmission, and more particularly to shift control when a vehicle is in a coasting state when a foot is released from an accelerator pedal.

As a continuously variable transmission, a belt type continuously variable transmission that includes a pair of pulleys and a belt that spans between the pulleys and realizes a continuously variable transmission by changing the groove width of each pulley has been put into practical use. . In a vehicle equipped with such a belt-type continuously variable transmission, as described in Patent Document 1, a shift is performed according to a shift line set according to the accelerator operation amount during traveling.
JP 2000-309236 A

  In the belt-type continuously variable transmission, when the accelerator pedal is released, the operating point of the transmission moves to the shift line (coast line) set to the highest side, and the engine rotation speed is greatly reduced.

  However, in a situation where the driver demands acceleration and the accelerator pedal is depressed and reaccelerated immediately after the accelerator pedal is released, the gear ratio at the time of reacceleration is the highest in a transmission that performs the above-described shift control. Since the engine speed is changed to the high side and the engine speed is low, the acceleration performance is deteriorated, and the acceleration response intended by the driver cannot be obtained.

  The present invention has been made in view of such technical problems of the prior art, and an object of the present invention is to improve the reacceleration performance after an accelerator pedal release operation in a vehicle equipped with a continuously variable transmission.

  Detects and records the required torque equivalent value such as the driver's accelerator operation amount and throttle opening, and when the required torque equivalent value becomes zero, stores it in the shift map according to the recorded required torque equivalent value. A coast line on the higher rotational speed side than the normal coast line, which is a shift line corresponding to the required torque equivalent value of zero, is set, and a shift is made to the coast line on the higher rotational speed side.

  Compared to the case of shifting to a normal coast line, the engine speed during coasting is higher and the gear ratio is maintained at the low side. Acceleration performance can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a schematic configuration of a vehicle equipped with a continuously variable transmission according to the present invention. The engine 1 as a power source is an internal combustion engine such as a gasoline engine or a diesel engine. The power of the engine 1 is transmitted to the drive wheels 7 via the torque converter 2, continuously variable transmission 3, and differential unit 6.

  The continuously variable transmission 3 interposed in the middle of the power transmission path of the engine 1 is a so-called belt-type continuously variable transmission, and includes a primary pulley 4 and a secondary pulley 5 with adjustable groove widths, and pulleys 4 and 5. It is composed of a metal belt that runs between them. The pulleys 4 and 5 are supplied with hydraulic pressure from a hydraulic circuit (not shown) to change the groove width, thereby changing the gear ratio of the continuously variable transmission 3.

  The engine 1 and the pulleys 4 and 5 are provided with rotational speed sensors 11 to 13, respectively. The engine rotational speed, the primary rotational speed, and the secondary rotational speed detected by the rotational speed sensors 11 to 13 are based on the driving state of the vehicle. It is input to the controller 20 as a signal to indicate.

  In addition to this, the controller 20 includes an accelerator operation amount sensor 14 for detecting the operation amount of the accelerator pedal, a vehicle speed sensor 15 for detecting the vehicle speed from the rotational speed of the drive wheels 7, and an air conditioner for detecting the operation state (ON / OFF) of the air conditioner. A detection signal from a throttle opening sensor 17 that detects the opening of a throttle valve that adjusts the intake amount of the switch 16 and the engine 1 is also input. In the following control, the accelerator operation amount is used as the driver's required torque equivalent value, but the throttle opening may be used instead.

  A navigation system 18 is attached to the vehicle. The navigation system 18 compares the current position of the vehicle measured by GPS with the map information stored in the navigation system 18 or obtainable from the outside, so that the gradient of the currently traveling road, that is, the currently traveling road Is an uphill road, a downhill road, or a flat road, and the determination result is transmitted to the controller 20.

  The controller 20 performs output control of the engine 1 and shift control of the transmission 3 based on these input signals. A shift map as shown in FIG. 2 is stored in the memory of the controller 20, and in the shift control, a target shift ratio (refer to this shift line map based on the input vehicle speed and accelerator operation amount ( The target primary rotational speed) is set, and the groove widths of the primary pulley 3 and the secondary pulley 4 are changed so that the actual speed ratio of the transmission 3 approaches the target speed ratio.

  By the way, if the foot is released from the accelerator pedal while traveling with the accelerator pedal depressed, the operating point of the transmission 3 moves to the coast line set to the highest side in the conventional shift control. As a result, the transmission ratio of the transmission 3 was changed to the highest side, and the primary rotational speed was greatly reduced. However, in such a configuration, the driver's intention to accelerate is strong, and even if the accelerator pedal is released, it will not accelerate even if the accelerator pedal is depressed in a situation where the accelerator pedal is depressed and then reaccelerated immediately. The acceleration response intended by the driver cannot be obtained.

  Therefore, in the present invention, the strength of the driver's intention to accelerate is determined from the operation history of the accelerator pedal until the accelerator pedal is released, and when the accelerator pedal is released, the normal coasting is performed according to the driver's acceleration intention. A limit coast line (FIG. 6) or a variable coast line (FIG. 7) is set on the higher rotational speed side than the line, and the shift is performed so that the operating point of the transmission 3 is on the limit coast line or the variable coast line. To do.

  FIG. 2 and FIG. 3 are flowcharts of a part of the shift control performed by the controller 20 relating to the shift control when the accelerator pedal is released and the vehicle enters the coast running state (hereinafter referred to as “coast shift control”). The shift control when entering the coasting state will be described with reference to this.

  FIG. 2 is a flowchart relating to a start portion of coast shift control. According to this, first, in step S1, it is determined whether or not the vehicle speed VSP exceeds the control start vehicle speed VSPlow1, and if it exceeds, the process proceeds to step S2. The control start vehicle speed VSPlow1 is set to a value of about 20 km / h, for example.

  When the processing proceeds to step S2, monitoring of the accelerator operation amount APO is started and the result is recorded in the memory in the controller 20. This is based on the history of the accelerator operation amount until the accelerator pedal is released and the accelerator operation amount APOz immediately before the accelerator pedal is released (hereinafter referred to as the accelerator operation amount immediately before the accelerator is turned off) APOz. Because.

  The driver's acceleration intention can be determined based on, for example, the average value of the accelerator operation amount APO recorded until the accelerator pedal is released. The higher the average value, the higher the acceleration intention, and vice versa. Is determined to be low. The method of determining the acceleration intention is not limited to this, and the determination may be made based on the maximum value of the accelerator operation amount APO during the monitoring period, the fluctuation range of the accelerator operation amount APO, variation, and the like. Alternatively, these parameters may be comprehensively determined to increase the determination accuracy of the acceleration intention.

  Further, the driver's intention to accelerate can be determined from the accelerator operation amount APOz immediately before the accelerator is turned off, and it can be determined that the driver's intention to accelerate is larger as the accelerator operation amount APOz just before the accelerator is turned off.

  In step S3, it is determined whether or not the accelerator pedal is released. If it is determined that the accelerator operation amount APO is zero and the accelerator pedal is released, the process proceeds to step S4. If not, the process returns to step S3 and the accelerator operation amount is determined. Continue monitoring APO.

  In step S4, it is determined whether or not the accelerator operation amount APOz immediately before the accelerator is off exceeds the permitted APO. The permission APO is a value set near zero. It is determined whether or not the permitted APO has been exceeded. When the accelerator operation amount APOz immediately before the accelerator is OFF is lower than the permitted APO, the operating point of the transmission 3 is close to the normal coast line, and a variable coast line as described later is used. This is because even if it is set, it is the same as the normal coast line, or even on the low rotational speed side, and there is no point in setting the variable coast line. For this reason, when the accelerator operation amount APOz immediately before the accelerator OFF is below the permission APO, the routine proceeds to step S5, where the normal shift control, that is, the shift line is set to the normal coast line, and the operating point of the transmission 3 is set to the normal coast line. Change the speed so that it is on the line.

  On the other hand, if the accelerator operation amount APOz immediately before the accelerator OFF exceeds the permission APO, the process proceeds to step S6, and it is determined whether the accelerator operation amount APOz immediately before the accelerator OFF exceeds the limit APO. The limit APO is set to a value of about 4/8, for example. Whether the limit APO is exceeded or not is determined when the accelerator operation amount APOz immediately before the accelerator is off exceeds the limit APO. Although the driver's intention to accelerate is considered strong, the accelerator immediately before the accelerator is OFF as described later. When the variable coast line is set by offsetting the shift line corresponding to the manipulated variable APOz, and the shift is performed so that the operating point of the transmission 3 comes to the variable coast line after releasing the accelerator pedal, the primary rotational speed (≈ engine rotational speed) ) Does not decrease so much, and the gear ratio of the transmission 3 remains low, so that the engine brake acts excessively and causes the driver to feel uncomfortable.

  Therefore, if the accelerator operation amount APOz immediately before the accelerator is off exceeds the limit APO, the process proceeds to step S7, and the shift line is set to a limit coast line set so that the primary rotation speed remains in the middle rotation speed range. Shifting is performed so that the operating point of the machine 3 is on the limit coast line. Specifically, as shown in FIG. 6, the limit coast line is set by offsetting the shift line corresponding to the limit APO to the low rotation speed side (high side).

  As a result, when the accelerator pedal is released and the vehicle is in a coasting state, a shift is performed so as to move on the limit coast line. Compared to conventional shift control that shifts to the normal coast line when the accelerator pedal is released, the primary rotation speed is maintained at a higher level and the gear ratio is maintained at the low side. Good acceleration performance can be obtained even when In addition, although the primary rotation speed is maintained high, it is moderately reduced as compared to before the accelerator operation amount APO becomes zero, so that excessive engine braking can be suppressed.

  On the other hand, if the accelerator operation amount APOz immediately before the accelerator OFF is less than the limit APO in step S6, the process proceeds to step S8 and subsequent steps, and the shift line corresponding to the accelerator operation amount APOz immediately before the accelerator OFF is offset to the low rotation speed side to be variable. Set the coast line.

  In step S8, the offset amount Hs is set. As the offset amount Hs, a map for calculating the offset amount Hs is selected based on the operating state of the air conditioner and the gradient information of the road that is currently running, and the primary amount immediately before the accelerator pedal is released with reference to the selected map. It is set by reading out the rotation speed and Hs corresponding to the driver's acceleration intention. Here, the driver's intention to accelerate is determined by the average accelerator operation amount calculated based on the history of the accelerator operation amount APO recorded in step S2. However, as already described, the driver's intention to accelerate is You may make it judge with a parameter.

  FIG. 5 shows an example of a map selected based on the operating state of the air conditioner and the gradient information of the currently traveling road. The map stores an offset amount in the primary rotation speed and the average accelerator operation amount.

  The offset amount Hs is set to a smaller value as the primary rotation speed is lower and as the average accelerator operation amount is larger. This is because when the primary rotational speed is high, the rotational speed of the engine 1 is high, so that the offset amount Hs is increased to increase the amount of decrease in the primary rotational speed so that excessive engine braking does not act. On the other hand, when the average accelerator operation amount is large, the driver's intention to accelerate is strong, so that the speed reduction ratio is kept as low as possible by suppressing the drop in the primary rotation speed, and the acceleration response when the accelerator pedal is depressed next time Is to increase

  Six types of maps similar to those shown in FIG. 5 are prepared according to the operation state of the air conditioner (ON or OFF) and the slope of the road surface (whether it is an uphill road, a downhill road or a flat road). Both maps have the same characteristics for the primary rotation speed and the average accelerator operation amount, and the offset amount obtained by referring to the map as the primary rotation speed is lower and the average accelerator operation amount is larger. Hs becomes smaller.

  However, at the same primary rotation speed and average accelerator operation amount, the offset amount Hs obtained by referring to the air conditioner ON map is smaller than the offset amount Hs obtained by referring to the air conditioner OFF map. This is because when the air conditioner is ON, the engine brake becomes larger than when the air conditioner is OFF, so that the offset amount Hs is reduced to suppress an increase in the engine brake.

  At the same primary rotation speed and average accelerator operation amount, the offset amount Hs obtained by referring to the map of the uphill road is smaller than the offset amount Hs obtained by referring to the map of the flat road. This is because uphill roads require higher acceleration response than flat roads, so reducing the offset Hs keeps the primary rotation speed high and keeps the gear ratio low, thereby reacceleration. This is to increase the acceleration response at the time. On the contrary, the offset amount Hs obtained by referring to the map of the downhill road is larger than the offset amount Hs obtained by referring to the map of the flat road or the uphill road. This is because the downhill road is less noticeable in acceleration performance than the uphill road and the flat road, and so high acceleration response is not required.

  Here, it is assumed that the offset amount Hs obtained by referring to the map of the downhill road is larger than the offset amount Hs obtained by referring to the map of the flat road or the uphill road. It will be less effective. Therefore, when emphasizing engine braking on downhill roads, the offset amount Hs obtained by referring to the downhill road map is equal to the offset amount Hs obtained by referring to the flat road or uphill road map, Alternatively, it may be set to a smaller value.

  After the offset amount Hs is set in this way, the process proceeds to step S9, and a shift line (APOz = 2/8 in this example) corresponding to the accelerator operation amount APOz immediately before the accelerator OFF is set in step S8 as shown in FIG. The variable coast line is set by offsetting to the low rotational speed side (high side) by the offset amount Hs. In step S10, a shift is performed so that the operating point of the transmission 3 is on the variable coast line set in step S9.

  Therefore, when the accelerator pedal is released and the vehicle enters the coast running state, a shift is performed so as to move on the variable coast line. When the accelerator pedal is released, the primary rotation speed is kept higher and the gear ratio is kept low compared to when shifting to the normal coast line, so when the accelerator pedal is subsequently depressed. In addition, good acceleration performance can be obtained.

  The flowchart of FIG. 3 that is executed subsequent to the flowchart of FIG. 2 is a flowchart relating to the release portion of the coast shift control started in FIG.

  First, in step S11, it is determined whether the vehicle is traveling on a limit coast line or a variable coast line. When traveling on the limit coast line or variable coast line, the process proceeds to step S12. Otherwise, normal control has already been performed, and the release process described below is unnecessary, so the process ends.

  In step S12, it is determined whether the vehicle speed VSP has become lower than the release vehicle speed VSPlow2. This is because when the vehicle speed VSP decreases, the influence of the engine brake gradually increases. Therefore, when the vehicle speed VSP becomes lower than the release vehicle speed VSPlow2, the traveling on the limit coast line or the variable coast line is stopped. This is for shifting to the normal shift control. The release vehicle speed VSPlow2 is set to a vehicle speed at which the influence of the engine brake starts to increase, for example, a value of about 35 km / h. If it is determined in step S12 that the vehicle speed VSP is lower than the release vehicle speed VSPlow2, the process proceeds to step S13 and shifts to normal shift control.

  On the other hand, if it is determined in step S12 that the vehicle speed VSP is not lower than the release vehicle speed VSPlow2, the process proceeds to step S14 to determine whether or not the accelerator pedal is depressed.

  If it is determined that the accelerator pedal is depressed, the process proceeds to step S15, and monitoring of the operation amount of the accelerator pedal is started. Otherwise, the process returns to step S12. In step S16, it is determined whether or not the accelerator operation amount APO exceeds the accelerator operation amount APOz immediately before it is determined in step S3 that the accelerator pedal has been released. Transition to control. Step S15 is repeated until the accelerator operation amount APO exceeds the accelerator operation amount APOz immediately before the accelerator OFF, whereby the accelerator operation amount APO is on the limit coast line or the variable coast line until the accelerator operation amount APO exceeds the accelerator operation amount APOz immediately before the accelerator OFF. Shift control is continued.

  Therefore, when the accelerator pedal is released and the vehicle is in a coasting state, a limit coast line or a variable coast line is set as the shift line, and the shift control is started so that the operating point of the transmission 3 is on it. The shift control is continued until one of the following two conditions is satisfied.

Condition 1: Vehicle speed VSP falls below release vehicle speed VSPlow2 Condition 2: The accelerator pedal is depressed, and the accelerator operation amount APO is greater than the accelerator operation amount APOz immediately before the accelerator pedal is released and coasting starts. When the condition is satisfied and the shift from the limit coast line or variable coast line to normal shift control is performed, the operating point of the transmission 3 is set on the limit coast line or Shift control is performed so as to gradually move from a point on the variable coast line to a point on the shift line set by normal shift control.

  Next, the operation of performing the above shift control will be described.

  FIG. 6 shows the state of the shift operation when the accelerator pedal operation amount APOz immediately before the accelerator pedal is released exceeds the limit APO.

  When the accelerator operation amount APOz immediately before the accelerator is off exceeds the limit APO (shaded area I in the figure), the driver's intention to accelerate is considered strong. Although it is necessary to set the coast line on the higher rotational speed side than the coast line, it is necessary to suppress the occurrence of excessive engine braking. Therefore, in such a case, the limit coast line set slightly lower than the shift line corresponding to the limit APO is set as the shift line so that the operating point of the transmission 3 is on the limit coast line. Shifting is performed.

  As a result, during coasting, the primary rotational speed is maintained higher and the gear ratio remains low compared to when shifting to the normal coast line. Good acceleration performance can be obtained. Further, since the primary rotation speed is appropriately reduced, excessive engine braking does not act.

  FIG. 7 shows the state of the shifting operation when the accelerator pedal operation amount APOz immediately before that exceeds the permitted APO but is below the limit APO (shaded area II in the figure) when the accelerator pedal is released. Is. In this case, the variable coast is set by offsetting the shift line corresponding to the accelerator operation amount APOz immediately before the accelerator OFF to the low rotation speed side by an offset amount Hs determined according to the driver's intention to accelerate, the primary rotation speed, and the vehicle speed. A line is set, and a shift is performed so that the operating point of the transmission 3 comes to this variable coast line.

  Therefore, during coasting, when the primary rotation speed is maintained higher and the gear ratio stays low compared to when shifting to the normal coast line, the accelerator pedal is depressed and reaccelerated. Can obtain good acceleration performance.

  FIG. 8 is a time chart showing a state when the shift control is performed. In the figure, the solid line indicates a comparative example in which the shift control is performed, and the broken line indicates a comparative example in which the shift control is not performed (when a normal coast line is used during coasting).

  When the accelerator pedal is depressed at time t1 and the vehicle starts, monitoring of the accelerator operation amount is started when the vehicle speed exceeds the control start vehicle speed VSPlow1.

  Thereafter, when the accelerator pedal is released at time t2, a limit coast line or a variable coast line is set based on the accelerator operation amount APOz immediately before the accelerator is turned off, and the speed is changed so that the operating point of the transmission 3 comes to the limit coast line or the variable coast. Is done.

  The vehicle enters the coasting state by releasing the accelerator pedal (time t2 to t3), but the primary coasting speed is set because the limit coast line or the variable coast line is set higher than the normal coasting line. Is maintained higher than in the case where the shift control of the present invention is not performed. However, since the engine brake is stronger than when the conventional shift control is performed, the drop in the vehicle speed is increased.

  When the accelerator pedal is depressed at time t3, the vehicle starts reacceleration. In the comparative example in which the speed change control of the present invention is not performed, it takes time to increase the depressed primary rotational speed due to the inertia of the engine, and the vehicle speed at the start of re-acceleration is performed by the speed change control of the present invention. Although it is higher than the case, it can be seen that the subsequent increase in vehicle speed is delayed. On the other hand, when the speed change control of the present invention is performed, the primary rotational speed during coasting is kept high and the speed ratio is kept low, which is good when the accelerator pedal is depressed and reaccelerated. Acceleration performance can be obtained.

  FIG. 9 shows a case where the vehicle speed is shifted to the normal shift control because the vehicle speed is lower than the release vehicle speed VSPlow2 when traveling on the variable coast line. If the accelerator pedal remains released, the shift line is set to the normal coast line in the normal shift control after the transition, but the operating point of the transmission 3 immediately moves from the variable coast line to the normal coast line. If shifting is performed in this manner, the gear ratio may change suddenly and the engine rotational speed may change suddenly, or the engine brake may suddenly stop working, which may cause the driver to feel uncomfortable. For this reason, in the shift control of the present invention, when shifting from the state of traveling on the variable coast line to the normal shift control, the shift ratio gradually approaches the shift ratio on the shift line set by the normal shift control. So that the speed is changed. Thereby, the uncomfortable feeling given to the driver can be reduced. FIG. 9 shows a case where the shift control on the variable coast line is canceled, but the same control is performed when the shift control on the limit coast line is canceled and the shift to the normal shift control is performed.

  As mentioned above, although embodiment of this invention was described, it becomes as follows when the effect of this invention is put together.

  The required torque equivalent value (accelerator operation amount, throttle opening, etc.) is detected and recorded. When the required torque equivalent value becomes zero, it is stored in the shift map according to the recorded required torque equivalent value. A coast line (limit coast line or variable coast line) on the higher rotational speed side than the normal coast line corresponding to the required torque equivalent value zero is set, and the gear is shifted to the coast line set on the higher rotational speed side. As a result, when coasting, the engine speed is higher and the gear ratio is kept low compared to when shifting to the normal coast line. Can obtain good acceleration performance.

  When the required torque equivalent value immediately before the required torque equivalent value becomes zero is larger than the first predetermined value (limit APO), the shift line corresponding to the first predetermined value stored in the shift map is used. Also shifts to the limit coast line (FIG. 6) set on the low rotational speed side. As a result, during coasting, the primary rotational speed is increased and the gear ratio is kept low compared to when shifting to the normal coast line. Good acceleration performance can be obtained even when accelerating. Moreover, although the primary rotational speed is maintained at a high level, it is moderately reduced as compared with the value before the required torque equivalent value becomes zero, so that excessive engine braking can be suppressed.

  Further, when the required torque equivalent value immediately before the required torque equivalent value becomes zero is smaller than the first predetermined value, the shift line corresponding to the immediately preceding required torque equivalent value is set to be offset to the low rotational speed side. A variable coast line (FIG. 7) is set, and a shift is performed so that the operating point of the transmission is on the variable coast line. Therefore, when coasting, the primary rotational speed is maintained higher and the gear ratio is kept low compared to when shifting to the normal coast line. Excellent acceleration performance can be obtained.

  Furthermore, when setting the variable coast line, the driver's acceleration request is judged from the history of the required torque equivalent value until the required torque equivalent value becomes zero, and the offset amount is increased as the driver's acceleration request becomes stronger. Make it smaller. As a result, when the driver's intention to accelerate is strong, the drop in the primary rotation speed is suppressed so that the gear ratio stays low, and the responsiveness when the required torque equivalent value increases and accelerates is increased. Can do. As for the acceleration request, for example, it is determined that the acceleration request of the driver is stronger as the average value or the maximum value of the required torque equivalent value until the required torque equivalent value becomes zero. The acceleration request may be determined in consideration of variations in the required torque equivalent value.

  Further, the offset amount is set according to the operating state of the air conditioner and the slope of the road that is currently running. By reducing the amount of offset when the air conditioner is operating compared to when the air conditioner is not operating, the effect of increased engine braking when the air conditioner is operating can be mitigated. As a result, acceleration performance on the uphill road can be improved.

  Further, when the value corresponding to the required torque immediately before becoming zero is smaller than the second predetermined value (permission APO), the shift is performed according to the normal coast line. This is the same as the normal coast line (shift line corresponding to zero accelerator operation amount) even if the variable coast line is set when the required torque equivalent value that becomes zero is below the second predetermined value, or This is because there is no point in setting a variable coast line because the rotation speed is further lowered.

  Further, when the vehicle speed becomes lower than a predetermined low vehicle speed (VSPlow2), the shift line is changed from the limit coast line or the variable coast line to the normal coast line. When the vehicle speed decreases, the influence of the engine brake gradually increases. When the vehicle speed becomes lower than the predetermined low vehicle speed in this way, the shift line is changed to the normal coast line and the engine is shifted excessively. It is possible to prevent the driver from feeling uncomfortable due to the brake.

1 is a schematic configuration diagram of a vehicle equipped with a continuously variable transmission according to the present invention. It is an example of a shift map. It is a flowchart of the part regarding the start of coast shift control. It is a flowchart of the part regarding cancellation | release of coast shift control. It is a map for setting the offset amount Hs. It is the figure which showed the operation | movement in the case of shifting to a limit coast line. It is the figure which showed the operation | movement in the case of shifting to a variable coast line. It is a time chart for demonstrating the effect of this invention. It is the figure which showed a mode that the vehicle speed fell and the gear shift on a variable coast line was cancelled | released.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter 3 Continuously variable transmission 4 Primary pulley 5 Secondary pulley 7 Drive wheel 11 Engine rotational speed sensor 12 Primary rotational speed sensor 13 Secondary rotational speed sensor 14 Accelerator operation amount sensor 15 Vehicle speed sensor 16 Air conditioner switch 17 Throttle opening sensor 18 Navigation system 20 Controller

Claims (12)

An engine as a power source,
Drive wheels to which the engine power is transmitted;
A continuously variable transmission that is provided between power transmission paths from the engine to the drive wheels and that can continuously change a speed ratio that is a rotational speed ratio between an input side and an output side;
Means for detecting the driver's required torque equivalent value;
Means for storing the detected required torque equivalent value;
A shift map storing shift lines defining the relationship between the vehicle speed and the gear ratio of the continuously variable transmission for each required torque equivalent value;
Shift control means for controlling a gear ratio of the continuously variable transmission;
With
The shift control means is a shift line corresponding to the required torque equivalent value zero stored in the shift map in accordance with the recorded required torque equivalent value when the required torque equivalent value becomes zero. A continuously variable transmission-equipped vehicle, characterized in that a coast line on a higher rotational speed side than a normal coast line is set and a shift is made to the coast line on the higher rotational speed side.   When the required torque equivalent value immediately before the required torque equivalent value becomes zero is greater than a first predetermined value, the shift control means is configured as a coast line on the higher rotational speed side than the normal coast line. 2. The continuously variable transmission according to claim 1, wherein a limit coast line set to a lower rotational speed side than a shift line corresponding to the first predetermined value stored in the shift map is set. vehicle.   When the required torque equivalent value immediately before the required torque equivalent value becomes zero is smaller than a first predetermined value, the shift control means is configured as a coast line on the higher rotational speed side than the normal coast line. The variable coast line set by offsetting the shift line corresponding to the required torque equivalent value immediately before the required torque equivalent value becomes zero to the low rotational speed side is set. Vehicle with a continuously variable transmission.   The shift control means determines the strength of the driver's acceleration request from the history of the required torque equivalent value until the required torque equivalent value becomes zero. 4. The continuously variable transmission vehicle according to claim 3, wherein the offset amount is reduced.   5. The shift control means determines that the driver's acceleration request is stronger as the average value of the required torque equivalent value until the required torque equivalent value becomes zero is larger. Vehicle with a continuously variable transmission.   The shift control means determines that the driver's acceleration request is stronger as the maximum value of the required torque equivalent value becomes larger until the required torque equivalent value becomes zero. Vehicle with a continuously variable transmission.   The continuously variable transmission-equipped vehicle according to any one of claims 3 to 6, wherein the shift control means makes the offset amount due to the offset smaller when the air conditioner is activated than when the air conditioner is not activated.   The continuously variable transmission-equipped vehicle according to any one of claims 3 to 7, wherein the shift control means changes an offset amount by the offset according to a gradient of a road on which the vehicle is currently traveling.   The shift control means does not set a coast line on the higher rotation speed side than the normal coast line when the required torque equivalent value immediately before the required torque equivalent value becomes zero is smaller than a second predetermined value. The vehicle with a continuously variable transmission according to any one of claims 1 to 8, wherein the vehicle shifts to the normal coast line.   Even when the shift control means is traveling on a coast line on a higher rotational speed side than the normal coast line, the shift line is set to the normal coast line when the vehicle speed is lower than a predetermined low vehicle speed. The vehicle with a continuously variable transmission according to any one of Claims 1 to 9, wherein the vehicle is changed to   The vehicle with a continuously variable transmission according to any one of claims 1 to 10, wherein the required torque equivalent value is an operation amount of an accelerator pedal.   The continuously variable transmission vehicle according to any one of claims 1 to 11, wherein the required torque equivalent value is a throttle opening.

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