JP4314151B2 - Coasting control device for continuously variable transmission - Google Patents

Description

  In the present invention, a vehicle equipped with a continuously variable transmission represented by a V-belt type continuously variable transmission or a toroidal type continuously variable transmission is coasted (coast travel) in an accelerator pedal release state (a state where the accelerator pedal is depressed). The present invention relates to a device for suitably controlling the continuously variable transmission including the lockup release control of the torque converter.

  Vehicles must satisfy the requirements of a trade-off relationship between improved power performance and improved fuel efficiency and drivability, such as a V-belt continuously variable transmission and a toroidal continuously variable transmission. The step transmission is very useful as a means for satisfying these requirements at a high level.

By the way, as described in Patent Document 1, the continuously variable transmission is usually controlled in accordance with a predetermined shift line that defines a target input rotational speed with respect to the vehicle speed for each depression amount of the accelerator pedal.
As will be described in detail with reference to FIG. 13 (a), the shift lines are set in advance as the target input speed tNpri for the vehicle speed VSP for each accelerator pedal depression amount APO (0/8 to 8/8). Then, the target input rotational speed tNpri is obtained from the accelerator pedal depression amount APO and the vehicle speed VSP, and the continuously variable transmission is subjected to shift control so that the actual input rotational speed Npri matches the target input rotational speed tNpri.

As a measure for improving the power performance for such a continuously variable transmission, which is described in Patent Document 1, a shift line during coasting where the accelerator pedal depression amount APO is set to 0 as indicated by α in FIG. A countermeasure for changing the coast shift line in the direction of increasing the target input rotation as indicated by β is known.
In this way, when the coast shift line is raised, the transmission input rotational speed is kept high during coasting, so that the responsiveness at the time of reacceleration can be improved and the power performance can be improved.

  On the other hand, continuously variable transmissions typically receive engine rotation via a lock-up torque converter, and this torque converter is a lock-up that is directly connected between torque converter input and output elements at a higher vehicle speed than the lock-up vehicle speed. The lockup release state where the direct connection between the torque converter input / output elements is released at a low vehicle speed equal to or lower than the lockup release vehicle speed.

  By the way, when the vehicle speed at which the lock-up is released is as low as possible, the lock-up time becomes longer, and the decrease in engine rotation during coasting can be delayed. This also stops engine fuel supply during coasting. (Fuel cut) This is preferable in the sense that the fuel consumption can be improved by extending the time.

However, there are the following restrictions to reduce the lockup release vehicle speed during coasting.
Γ in FIG. 13 (b) indicates the highest input speed tNpri and vehicle speed VSP shown in FIG. 13 (a) by coasting with the accelerator pedal depression amount APO set to 0 with the torque converter locked up. The generation state of the vehicle deceleration G when decreasing in the direction of the arrow along the line and the coast shift line α of APO = 0 is shown.
In addition, G0 in FIG. 13 (b) illustrates an allowable deceleration limit value. When the vehicle deceleration G exceeds the allowable deceleration limit value G0, the occupant is drawn in and the driving feeling deteriorates and the vehicle performance decreases. If the speed G does not exceed the allowable deceleration limit value G0, the occupant is drawn and the feeling does not feel strange.
Therefore, when the coast shift line is normal as indicated by α, the coast lockup release vehicle speed needs to be determined so as not to be less than VSP1 in relation to drivability.
JP 2002-048224 A

By the way, when the coast shift line α is changed in the target input rotation increasing direction as indicated by β for improving the power as described above, in the case of a normal engine in which the engine intake amount is controlled by the throttle opening, the engine As a result of increasing the intake resistance of the engine by the increase in rotation,
When the torque converter is locked up and coasting is performed with the accelerator pedal depression amount APO set to 0, the target input rotational speed tNpri and the vehicle speed VSP are in the direction of the arrow along the highest shift line and the coast shift line β in FIG. The vehicle deceleration G that occurs when the vehicle speed decreases to a larger value than the γ characteristic in the case of the normal coast shift line α, as indicated by δ in FIG.
Therefore, when the coast shift line is set higher than the normal coast shift line α as indicated by β, the coast lock-up release vehicle speed must be determined so as not to be less than VSP2 (> VSP1) in relation to the drivability described above. There is.

  However, in general, the lockup release vehicle speed is usually fixed at a certain vehicle speed, and the coast shift line is lowered as indicated by α during driving when power performance is not important, and during driving when power performance is important. When the value is made variable as shown by β, the following problem arises.

  That is, when the coast lock-up release vehicle speed is set to the vehicle speed indicated by VSP1 in FIG. 13 (b), when the coast shift line is increased as indicated by β for driving in which power performance is important, in the vehicle speed range VSP2 to VSP1. The torque converter continues to be locked up, resulting in a problem that the drivability deteriorates due to the feeling of pulling in.

  On the other hand, when the coast lock-up release vehicle speed is set to the vehicle speed indicated by VSP2 in FIG. 13 (b), when the coast shift line is lowered as indicated by α for driving where power performance is not important, torque is applied in the vehicle speed range VSP2 to VSP1. Even if the converter is locked up, the drivability does not deteriorate due to the pull-in feeling, but the lock-up is released in the vehicle speed range, resulting in a problem that fuel consumption deteriorates.

The present invention allows the desired power performance to be obtained by changing the coast shift line according to the degree of emphasis on the power performance. Proposed a coasting control device for a continuously variable transmission that can control the coast lockup release vehicle speed so as not to cause problems related to fuel consumption deterioration,
Accordingly, it is an object of the present invention to solve all of the above problems and to achieve both a high-performance improvement in power performance and a improvement in fuel consumption and drivability that are in a trade-off relationship.

For this purpose, the coasting control device for a continuously variable transmission according to the present invention is as described in claim 1,
With a continuously variable transmission that receives engine rotation via a lock-up torque converter,
The continuously variable transmission is shift-controlled according to a planned shift line that defines a target input rotational speed with respect to the vehicle speed for each accelerator pedal depression amount,
The above-mentioned lockup type torque converter is premised on a power train that is in a lockup release state in which the direct connection between the torque converter input and output elements is released at a low vehicle speed below the lockup release vehicle speed,
A power performance emphasis degree calculating means for obtaining a degree of emphasis on the power performance from the driving state and the driving environment;
The coast shift line changing means for changing the coast shift line when the accelerator pedal depression amount is 0 so that the target input rotational speed is higher as the power performance importance determined by this means is higher;
A coast lockup release vehicle speed changing means for changing the coast lockup release vehicle speed when the accelerator pedal depression amount is 0 to the higher vehicle speed side is provided as the power performance importance degree is higher.

  According to the configuration of the present invention, the coast shift line changing means has a higher target input rotational speed for the coast shift line as the power performance emphasis degree is higher in accordance with the power performance emphasis degree obtained by the power performance emphasis degree computing means. Therefore, the power performance as required can be obtained during operation where power performance is important.

Further, the higher the emphasis on power performance, the more the coast lockup release vehicle speed changing means changes the coast lockup release vehicle speed when the accelerator pedal depression amount is 0 to the higher vehicle speed side,
When changing the coast shift line described above for power performance, the coast lockup release vehicle speed also changes according to the deceleration that changes with this change, and the coast lockup release vehicle speed decreases when the coast shift line rises. It is possible to solve the above-described problem that the drivability deteriorates due to too much, and the above-mentioned problem that the coast lockup release vehicle speed is too high when the coast shift line is lowered and the fuel consumption is deteriorated.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 shows a power train of a vehicle including a continuously variable transmission control device according to an embodiment of the present invention, and a control system thereof. The power train is composed of an engine 1 and a continuously variable transmission 2. .
Although the engine 1 is a gasoline engine, the throttle valve 3 is not mechanically connected to the accelerator pedal 4 operated by the driver, and is separated from the throttle pedal 3 so that the opening degree of the throttle valve 3 is electronically controlled by the throttle actuator 5. Eggplant.

The operation amount of the throttle actuator 5 is controlled by an engine controller 22 that responds to a command related to a target throttle opening tTVO, which is determined by the general controller 21 as will be described later, whereby the opening of the throttle valve 3 is controlled by the target throttle opening. The output of the engine 1 is basically controlled so as to become a value corresponding to the operation of the accelerator pedal 4 in accordance with tTVO, but can be controlled by factors other than the operation of the accelerator pedal as necessary.
The engine controller 22 not only performs the throttle opening control via the throttle actuator 5, but is not shown in the figure, but other fuel injection amount control, fuel cut control, ignition timing required for the operation of the engine 1 are also shown. Control shall also be performed.

The continuously variable transmission 2 is a well-known V-belt continuously variable transmission, and includes a primary pulley 7 that is drive-coupled to the output shaft of the engine 1 via a lock-up torque converter 6, and a secondary pulley 8 that is aligned with the primary pulley 7. And a V-belt 9 spanned between the two pulleys.
Then, the differential gear device 11 is drivingly coupled to the secondary pulley 8 via the final drive gear set 10, and a wheel (not shown) is rotationally driven by these.

The speed change operation of the continuously variable transmission 2 is such that, among the flanges forming the V-grooves of the primary pulley 7 and the secondary pulley 8, one movable flange is brought relatively close to the other fixed flange to make the V-groove width. Narrowing the width or conversely increasing the V groove width,
The stroke positions of both movable flanges are determined by the ratio of the primary pulley pressure Ppri and the secondary pulley pressure Psec from the transmission control hydraulic circuit 12.

The transmission control hydraulic circuit 12 includes a step motor 13 as a transmission actuator, and the transmission controller 23 is driven to a step position corresponding to a target transmission ratio tRTO, which will be described later. The continuously variable transmission is performed so that the ratio matches the target transmission ratio tRTO.
The transmission controller 23 further outputs a lockup (L / U) signal, which will be described later, to the transmission control hydraulic circuit 12, and the transmission control hydraulic circuit 12 directly connects the torque converter 6 and the input / output elements in response to this signal. It shall also be used to enter into a locked-up state or to release this lock-up.

When the transmission controller 23 calculates the target speed ratio tRTO, the target input rotation is determined from the accelerator pedal depression amount (hereinafter also referred to as accelerator opening) APO and the vehicle speed VSP based on the shift line illustrated in FIG. The target gear ratio tRTO is obtained by dividing the target input speed (target primary pulley speed) tNpri by the transmission output speed No (which can be obtained from the vehicle speed VSP). .
Here, the coast shift line α shown in FIG. 13A is appropriately changed as illustrated by β according to a change command Cup described later from the general controller 21.

  When the transmission controller 23 determines the lockup (L / U) signal, the lockup (L / U) signal is output while the vehicle speed VSP is higher than the lockup vehicle speed, and the torque converter 6 Command lockup, and command the lockup release of the torque converter 6 by not outputting the lockup (L / U) signal while the vehicle speed VSP is below the lockup release vehicle speed VSPo determined as described below. It shall be.

The target throttle opening tTVO command to the engine controller 22, the coast shift line change Cup command, and the coast lockup release vehicle speed VSPo command to the transmission controller 23 are respectively obtained by the calculation described later by the integrated controller 21.
Therefore, the general controller 21 has a signal from the accelerator opening sensor 24 that detects the depression amount (accelerator opening) APO of the accelerator pedal 4, and
A signal from the vehicle speed sensor 25 that detects the vehicle speed VSP from the rotation speed of the wheel,
When the accelerator pedal 4 is released (accelerator opening APO = 0), a signal from the idle switch 26 that is turned on is input.
These signals are also supplied to the engine controller 22 and the transmission controller 23 via the general controller 21, and are used for the above-described control by these controllers.

As shown in FIG. 2, the general controller 21 is composed of a calculation unit 21a and an output unit 21b. The calculation unit 21a further includes a continuously variable transmission (CVT) control unit, an engine (ENG ) Consists of a control unit.
The sporty degree calculation unit 31 constituting the CVT control unit corresponds to the power performance importance degree calculation means in the present invention, and calculates the required sporty degree Srto from the driving state and the driving environment by the processing shown in FIG. The result is output as shown in FIG.

In step S1 of FIG. 3, it is determined whether or not shift control is being performed in the forward automatic shift (D) range where the sporty degree Srto should be calculated. In step S2, the vehicle speed VSP calculates the sporty degree Srto. It is determined whether or not the power vehicle speed range VSPLo ≦ VSP <VSPHi. In step S3, it is determined whether or not the accelerator opening APO is the accelerator opening region APO ≧ APO1 where the sporty degree Srto should be calculated.
If these three conditions are not met, the control returns to step S1 and waits. When the three conditions are met, the sporty degree Srto is calculated as follows.

In step S4, the accelerator depression speed coefficient d for calculating the sportiness degree (Srto) is retrieved from the accelerator pedal depression speed (d / dt) APO based on the map of FIG.
In step S5, an accelerator opening coefficient t for calculating a sportiness degree (Srto) is searched from the accelerator opening APO based on the map of FIG.
In step S6, the vehicle speed coefficient v for calculating the sportiness degree (Srto) is searched from the vehicle speed VSP based on the map of FIG.

Next, in step S7, the sportiness degree Srto (= d × t × v) is calculated by multiplying the accelerator depression speed coefficient d, the accelerator opening coefficient t, and the vehicle speed coefficient v.
This sporty degree Srto represents the degree of importance of power performance according to the driving state, and not only from the driving state such as the accelerator pedal depression speed (d / dt) APO, accelerator opening APO, vehicle speed VSP, but also from the car navigation system Needless to say, it can also be determined by the driving environment such as road information and traffic jam information.
After the sporty degree Srto is calculated as described above, 1 is set to the sporty degree calculation flag Sfrg in step S8 to indicate this.

In step S9, it is checked whether or not the accelerator pedal is released depending on whether or not the idle switch 26 is ON.
When the accelerator pedal is in the released state, the holding time of the sportiness degree Srto by the above calculation is set in the timer Timer in step S10. However, if the accelerator pedal is not in the released state, the control is performed because the holding of the sporty degree Srto is unnecessary. Return to S9 and wait.

After the setting of the sporty degree holding time timer Timer is completed in step S10, it is checked in step S11 whether or not the accelerator pedal is released depending on whether or not the idle switch 26 is ON. In step S12, the sporty degree is maintained. Whether or not the holding time of the sportiness degree Srto has elapsed is checked based on whether or not the time timer Timer has become 0, and control is returned to step S11 until it has elapsed .

  If it is determined in step S11 that the accelerator pedal has been depressed or if it is determined in step S12 that the holding time of the sporty degree Srto has elapsed, the sporty degree holding time timer Timer is set to 0 in step S13. The sporty degree Srto is cleared to 0, the sporty degree calculation flag Sfrg is set to 0, the control is returned to step S1, and the above loop is repeated.

The sporty degree Srto obtained as described above is output as shown in FIG.
First, in step S21, it is checked whether or not the sporty degree calculation flag Sfrg is 1, whether or not the sporty degree Srto has been calculated. If it has been calculated, the calculated sporty degree Srto is stored in Srto in step S22. If not, Srto is set to 0 in step S23.
And Srto calculated | required as mentioned above in step S22 or step S23 is output as sportiness degree Srto in step S24.

  The coast shift line increase rate calculation unit 32 and the coast shift line increase amount calculation unit 33 constituting the CVT control unit of FIG. 2, and the coast shift line change command Cup output unit 34 in the output unit 21b of FIG. Corresponding to the shift line changing means, based on the sporty degree Srto from the sporty degree calculating unit 31, a command Cup for changing the coast shift line is obtained by the process as shown in FIG. Output to the controller 23.

The coast shift line increase rate calculation unit 32, the coast shift line increase amount calculation unit 33, and the coast shift line change command Cup output unit 34 will be described in detail with reference to FIG.
The coast shift line increase rate calculating unit 32 obtains the coast shift line increase rate Uprto from the sporty degree Srto based on the map exemplified in the step in the coast shift line increase rate calculating step 41 of FIG. The line increase rate Uprto is increased in response to the fact that the higher the sporty degree Srto is, the more important the driving performance is.

  In the coast shift line calculation processing step 42 in FIG. 8, the coast shift line increase amount calculation unit 33 does not place importance on power performance and desires luxury travel, as exemplified in the step, so that the sporty degree Srto = From the target input speed tNpri corresponding to the coast shift line α (same as α in FIG. 13) and the coast shift line increase rate Uprto at 0% (coast shift line increase rate Uprto = 0%), coast shift is performed. The amount of line rise Δup is obtained.

  Similarly, in the coast shift line calculation processing step 42 of FIG. 8, the coast shift line change command Cup output unit 34 converts the coast shift to the target input speed tNpri corresponding to the coast shift line α, as exemplified in the step. The line increase amount ΔUp is added to obtain a new coast shift line (in the coast shift line calculation processing step 42 in FIG. 8, for the sake of convenience, the coast shift line increase rate Uprto = 100% is shown as the coast shift line β). Then, a coast shift line change command Cup for changing the coast shift line to the new coast shift line is output to the transmission controller 23 in FIG.

  The coast lockup (L / U) release vehicle speed VSPo calculation unit 35 constituting the ENG control unit of FIG. 2 and the coast lockup (L / U) release vehicle speed VSPo output unit 36 in the output unit 21b of FIG. 9 corresponds to the coast lockup release vehicle speed changing means in FIG. 9, based on the coast shift line increase rate Uprto from the coast shift line increase rate calculation unit 32 (corresponding to the sporty degree Srto from the sporty degree calculation unit 31). The coast lock-up release vehicle speed VSPo is obtained by a process as specified, and this is output to the transmission controller 23 of FIG.

The coast lockup (L / U) release vehicle speed VSPo calculation unit 35 and the coast lockup (L / U) release vehicle speed VSPo output unit 36 will be described in detail with reference to FIG.
First, the coast lock-up (L / U) release vehicle speed VSPo calculation unit 35 calculates the coast shift line increase rate Uprto (calculated in the coast shift line increase rate calculation processing step 41 in FIG. 9 (the same as step 41 in FIG. 8)). The coaster lockup (L / U) release vehicle speed VSPo calculation processing step 43 shown in the figure from the sporty degree Srto), the air conditioner (A / C) illustrated in this step is activated (ON) or not activated The coast lockup (L / U) release vehicle speed VSPo is obtained based on a different map depending on whether (OFF).
The coast lock-up (L / U) release vehicle speed VSPo output unit 36 is also used in the coast lock-up (L / U) release vehicle speed VSPo calculation processing step 43 in FIG. ) The release vehicle speed VSPo is output to the transmission controller 23 in FIG.

Here, the reason why the coast lockup (L / U) release vehicle speed VSPo is increased in accordance with the increase in the coast shift line increase rate Uprto (sporty degree Srto) as illustrated in step 43 of FIG. 9 will be described below. .
As shown in FIG. 13, when the coast shift line is increased from α to β, the coast lockup (L / U) release vehicle speed is not increased from VSP1 to VSP2 as the coast shift line is increased. Therefore, the coast lockup (L / U) release vehicle speed VSPo is increased in accordance with the increase in the coast shift line increase rate Uprto (sporty degree Srto).

In addition, the deterioration of drivability due to the feeling of being pulled in becomes more pronounced when the air conditioner (A / C) is activated (ON) than when it is not activated (OFF). ) As shown in step 43 in FIG. 9, the release vehicle speed VSPo is set higher during operation (ON) than during operation (OFF) of the air conditioner (A / C).
However, in any case, the coast lockup (L / U) release vehicle speed VSPo has a deceleration in the lockup state that occurs while the vehicle speed decreases along the coastline changed as described above. Needless to say, it is necessary to increase the vehicle speed to the allowable deceleration limit value G0 exemplified in the above.

  The coast travel target throttle opening tTVO calculation unit 37 constituting the ENG control unit of FIG. 2 and the coast travel target throttle opening tTVO output unit 38 in the output unit 21b of FIG. Based on the coast shift line increase rate Uprto (corresponding to the sporty degree Srto from the sporty degree calculating unit 31), the target throttle opening tTVO during coasting is obtained by the process as shown in FIG. 1 to the engine controller 22.

The target throttle opening tTVO calculation unit 37 during coasting and the target throttle opening tTVO output unit 38 during coasting will be described in detail with reference to FIG.
First, the coast travel target throttle opening tTVO calculation unit 37 calculates the coast shift line increase rate Uprto (which is the same as the step 41 in the coast shift line increase rate calculation processing step 41 in FIG. 10 (the same as step 41 in FIGS. 8 and 9)). In the target throttle opening calculation processing step 44 in the figure from the corresponding sporty degree Srto), the map for each coast lock-up (L / U) release vehicle speed VSPo illustrated in this step (here, air conditioner A / C) 9 shows the target throttle opening tTVO during coasting based on the map of VSPo = 15 Km / h to VSPo = 25 Km / h shown in FIG.

  The coast driving target throttle opening tTVO output unit 38 also outputs the coast driving target throttle opening tTVO obtained as described above to the engine controller 22 of FIG. 1 in the target throttle opening tTVO calculation processing step 44 of FIG. Output.

  According to the above-described configuration of the present embodiment, as shown in FIG. 11, the higher the sporty degree (power performance emphasis degree) Srto is, the higher the sporty degree (power performance emphasis degree) Srto is, the more the coast shift line becomes the target input rotation speed. Since tNpri is changed in the direction of the arrow from α to β so as to increase tNpri, it is possible to obtain the required power performance during operation in which power performance is emphasized.

In addition, the higher the sporty degree (power performance importance degree) Srto, the higher the accelerator pedal depression amount APO is, the coast lock-up release vehicle speed VSPo is VSPo = VSPo1, VSPo = VSPo2, VSPo = VSPo3, VSPo = VSPo4, VSPo = From VSPo5 to change to the high vehicle speed side in the direction of the arrow,
When the coast shift line is changed to ensure the required power performance, the coast lockup release vehicle speed VSPo also changes in accordance with the deceleration that changes as described above with reference to FIG. The above-mentioned problem that the coast lockup release vehicle speed VSPo is too low when the shift line is raised and the drivability is deteriorated, and the coast lockup release vehicle speed VSPo is too high when the coast line is lowered and the above problem is that the fuel consumption is deteriorated Can be eliminated.

Moreover, even during coasting with the accelerator pedal depression amount APO set to 0, the throttle valve 3 is opened by the coasting target throttle opening tTVO obtained in the coasting target throttle opening calculation processing step 44 in FIG. Because it increases the opening of the engine intake passage,
The increase in deceleration due to the rise of the coast shift line is mitigated, and the coast lock-up release vehicle speed VSPo can be further reduced, and further improvement in fuel consumption can be achieved.

In the above-described embodiment, the case where the engine 1 (see FIG. 1) increases the engine intake passage opening by increasing the opening of the throttle valve 3 has been described.
As described in JP 2003-206769 A, when the engine is capable of non-throttle operation in which the opening of the throttle valve 3 is fixed near the maximum opening and the intake amount is controlled by controlling the intake valve lift characteristics,
As described above, the higher the sportiness degree (power performance importance degree) Srto, the higher the target input speed and the coast lockup release vehicle speed VSPo are changed to the higher vehicle speed side. It is good to operate the above-mentioned non-throttle operation.

The reason will be described below with reference to FIGS.
12 (a) and 12 (b) show how the vehicle deceleration G is generated when the coast shift line is increased from α to β as in FIGS. 13 (a) and 13 (b). Shows a comparison between a case where non-throttle operation is not performed and a case where non-throttle operation is performed.

That is, γ in FIG. 12 (b) is the same as that shown in FIG. 13 (b), and the accelerator pedal depression amount is obtained when the engine does not perform non-throttle operation and the torque converter is locked up. The vehicle deceleration when the target input speed tNpri and the vehicle speed VSP decrease in the direction of the arrow along the highest shift line in FIG. 12A and the coast shift line α with APO = 0 by coast driving with APO set to 0. The occurrence situation of G is shown.
Δ in FIG. 12 (b) is the same as that shown in FIG. 13 (b) by the same sign, and the accelerator pedal depression amount is obtained when the engine does not perform non-throttle operation and the torque converter is locked up. The vehicle deceleration when the target input speed tNpri and the vehicle speed VSP decrease in the direction of the arrow along the highest shift line in FIG. 12A and the coast shift line β with APO = 0 by coast running with APO set to 0. The occurrence situation of G is shown.

By the way, when the engine performs non-throttle operation, the target input speed tNpri and the vehicle speed VSP are along the highest shift line and the coast shift line α with APO = 0 in FIG. The vehicle deceleration G generated when the speed decreases in the direction of the arrow is a non-non-stop as shown by γ 'in FIG. 12 (b) because the non-throttle operation is an operation near the full throttle opening and the intake resistance is small. It is smaller than the vehicle deceleration G indicated by γ during throttle operation (normal operation) in the entire vehicle speed range during coasting.
Even when the coast shift line is raised as indicated by β as shown in FIG. 12 (a), the vehicle generated when coasting in the lock-up state is performed while the engine is performing non-throttle operation. The deceleration G is smaller in the entire vehicle speed range during coasting than the vehicle deceleration G indicated by δ during non-non-throttle operation (normal operation) as indicated by δ ′ in FIG.

Therefore, the target input rotational speed tNpri and the vehicle speed VSP are set to the highest shift line in FIG. 12A and the coast shift line α with APO = 0 by coast driving in the lock-up state without causing the engine to perform non-throttle operation. Along the direction of the arrow, when the vehicle deceleration G reaches the allowable deceleration limit value G0, the vehicle speed VSP1 was pulled in, and it was necessary to release the lockup to prevent feeling.
When the engine is operated in a non-throttle operation, the lock-up release can be delayed until the vehicle speed VSP1 'is lower than the vehicle speed VSP1 even under the same conditions.

Even when the coast shift line is raised as indicated by β in FIG.
Without causing the engine to perform non-throttle operation, the target input rotational speed tNpri and the vehicle speed VSP are set along the highest shift line in FIG. 12A and the coast shift line β of APO = 0 by coast driving in the lock-up state. When decreasing in the direction of the arrow, when the vehicle deceleration G reached the vehicle speed VSP2 that reached the allowable deceleration limit value G0, it was necessary to release the lockup to prevent feeling.
When letting the engine perform non-throttle operation, the lock-up release can be delayed until the vehicle speed VSP2 'is lower than the vehicle speed VSP2 even under the same conditions.

As is clear from the above, as described above, as the sportiness degree (power performance importance degree) Srto increases, the coast shift line is changed so that the target input rotational speed increases, and the coast lockup release vehicle speed VSPo is increased. When changing the vehicle speed side to run the engine non-throttle,
The coast lock-up release vehicle speed VSPo can be made lower than when non-throttle operation (normal operation) is performed.
Such a reduction in coast lockup release vehicle speed VSPo can delay the decrease in engine speed during coasting by extending the lockup time, and this also stops engine fuel supply during coasting (fuel cut). The time can be lengthened and further improvement in fuel consumption can be realized.

When the engine is operated in a non-throttle manner, the opening of the engine intake passage is increased by the coasting target throttle opening tTVO obtained in the coasting target throttle opening calculation processing step 44 of FIG. ,
Rather than relying on the operation of the throttle valve 3 as in the above-described embodiment, the opening of the engine intake passage is increased by controlling the intake valve lift characteristics to mitigate the increase in deceleration due to the rise of the coast shift line. Needless to say.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system diagram showing a power train for a vehicle including a coasting control device for a continuously variable transmission according to an embodiment of the present invention, together with its control system. It is a block diagram according to the function of the comprehensive controller in the power train control system. It is a flowchart which shows the sporty degree calculation program which the sporty degree calculating part shown in FIG. 2 performs. It is a flowchart which shows the sporty degree output program which the sporty degree calculating part performs. It is a change characteristic diagram of the accelerator pedal depression speed coefficient used in the calculation of the sporty degree. It is a change characteristic diagram of the accelerator opening coefficient used in calculating the sporty degree. It is a change characteristic diagram of the vehicle speed coefficient used in calculating the sporty degree. 3 is a flowchart showing a control program related to a coast shift line change process executed by a coast shift line increase rate calculation unit, a coast shift line increase amount calculation unit, and a coast shift line change command output unit shown in FIG. It is a flowchart which shows the control program regarding the coast lockup vehicle speed change process which the coast lockup cancellation vehicle speed calculating part shown in FIG. 2 and a coast lockup vehicle speed output part perform. It is a flowchart which shows the control program regarding the target throttle opening change process which the target throttle opening calculating part shown in FIG. 2 and the target throttle opening output part perform. FIG. 11 is a shift diagram showing a change state of a coast shift line and a change state of a coast lockup release vehicle speed according to the embodiment shown in FIGS. The situation of vehicle deceleration when the engine is operated in a non-throttle mode is shown in comparison with that during normal operation. (A) is a shift diagram having two cost shift lines. b) is an operational characteristic diagram showing the state of occurrence of vehicle deceleration when the engine is operated non-throttle and the state of occurrence of vehicle deceleration when the engine is normally operated for each coast shift line. . The example of the change of the coast shift line and the generation situation of the vehicle deceleration for each coast shift line are shown. (A) is a shift line diagram having two cost shift lines, and (b) is the coast shift line. It is an operation characteristic figure showing the occurrence situation of vehicle deceleration for every line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Continuously variable transmission 3 Throttle valve 4 Accelerator pedal 5 Throttle actuator 6 Lock-up torque converter 7 Primary pulley 8 Secondary pulley 9 V belt
10 Final drive gear set
11 Differential gear unit
12 Shift control hydraulic circuit
13 Step motor
21 General controller
22 Engine controller
23 Transmission controller
24 Accelerator position sensor
25 Vehicle speed sensor
26 Idle switch
31 Sporty degree calculator
32 Coast shift line rise rate calculation section
33 Coast shift line ascent calculation section
34 Coast shift line change command output section
35 Coast lockup release vehicle speed calculator
36 Coast lockup release vehicle speed output section
37 Target throttle opening calculator
38 Target throttle opening output section

Claims (5)

With a continuously variable transmission that receives engine rotation via a lock-up torque converter,
The continuously variable transmission is shift-controlled according to a planned shift line that defines a target input rotational speed with respect to the vehicle speed for each accelerator pedal depression amount,
In the power train in which the lockup torque converter is in a lockup release state in which the direct connection between the torque converter input / output elements is released at a low vehicle speed equal to or lower than the lockup release vehicle speed
A power performance emphasis degree calculating means for obtaining a degree of emphasis on the power performance from the driving state and the driving environment;
Coast shift line changing means for changing the coast shift line when the accelerator pedal depression amount is 0 so that the target input rotational speed is higher as the degree of emphasis on power performance obtained by the means is higher;
A continuously variable transmission comprising: a coast lockup release vehicle speed changing means for changing the coast lockup release vehicle speed when the accelerator pedal depression amount is 0 to a higher vehicle speed as the degree of emphasis on power performance is higher. Coast running control device. In the coasting control device for the continuously variable transmission according to claim 1,
The coast lockup release vehicle speed changing means is configured to reduce the coast lockup release vehicle speed to a deceleration in a lockup state that occurs while the vehicle speed decreases along the coast shift line changed by the coast shift line change means. A coasting control device for a continuously variable transmission, characterized in that the vehicle speed is increased to a limit value. The coasting control device for continuously variable transmission according to claim 1 or 2,
When the coast shift line changing means changes the coast shift line so as to increase the target input rotational speed, and the coast lockup release vehicle speed changing means changes the coast lockup release vehicle speed to the high vehicle speed side, the intake air of the engine A coasting control device for a continuously variable transmission, characterized in that the vehicle deceleration is suppressed by increasing the road opening and decreasing the intake resistance. The coast of the continuously variable transmission according to claim 3, wherein the engine is an engine capable of non-throttle operation in which the throttle opening is fixed near the maximum opening and the intake amount is controlled by controlling the intake valve lift characteristics. In the running control device,
When the coast shift line changing means changes the coast shift line so that the target input rotational speed becomes high, and the coast lockup release vehicle speed changing means changes the coast lockup release vehicle speed to the high vehicle speed side, the engine is set to non- A coasting-time control device for a continuously variable transmission, characterized in that an increase in engine intake passage opening degree is realized by controlling the intake valve lift characteristics by performing throttle operation. In the coast running control device for a continuously variable transmission according to any one of claims 1 to 4,
The power performance emphasis degree calculating means obtains the degree of emphasis on power performance based on the accelerator pedal depression amount, the accelerator pedal depression speed, and the vehicle speed immediately before shifting to coasting where the accelerator pedal depression amount is zero. A coasting control device for a continuously variable transmission, characterized by being a thing.

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