JP2010254036A - Vehicle stop determination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle stop determination device for reducing vibration generated when a lockup function and a fuel cut function are released. <P>SOLUTION: A vehicle vibration reduction device 1 includes an ECU 2 which controls the lockup function of an automatic transmission 15 and the fuel cut function of an engine 11. In this ECU 2, when the lockup function and the fuel cut function are released, the release timing of the fuel cut function is set to be delayed in a 1/2 cycle of the drive system resonance frequency of a vehicle X from the release timing of the lockup function. Thus, the fluctuations of L/U longitudinal acceleration and F/C longitudinal acceleration act on each other to offset each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle vibration reducing device for reducing vibration of a vehicle such as an automobile.

  2. Description of the Related Art Conventionally, a vehicle vibration reduction device for reducing vibrations in a vehicle including an automatic transmission having a lockup function and an engine having a fuel cut function has been developed (see, for example, Patent Document 1). In such a vehicle vibration reducing device, when releasing the lockup function and the fuel cut function, the response time until the differential pressure of the lockup clutch becomes substantially zero and the response until the engine output torque rises to substantially zero. A relative delay time is provided for the release timing of the lockup function and the fuel cut function so that the times coincide with each other.

JP 2007-314209 A

  Here, in recent vehicle vibration reduction devices, it is desired to reduce vibration generated when the lockup function and the fuel cut function are canceled.

  Then, this invention makes it a subject to provide the vehicle stop determination apparatus which can reduce the vibration which arises when canceling | releasing a lockup function and a fuel cut function.

  In order to achieve the above object, a vehicle vibration reduction device according to the present invention is a vehicle vibration reduction device for reducing vibration of a vehicle including an automatic transmission having a lockup function and an engine having a fuel cut function. Control means for controlling the lock-up function and the fuel cut function, and when the control means releases the lock-up function and the fuel cut function, the control means determines the release timing of the fuel cut function from the release timing of the lock-up function. The delay time is set so as to be delayed by approximately [n + 1/2] period (n is an integer) of the drive system resonance period.

  In this vehicle vibration reduction device, the release timing of the fuel cut function can be delayed by approximately [n + 1/2] period of the vehicle drive system resonance period from the release timing of the lockup function. Therefore, the vibration caused by the release of the lockup function (hereinafter referred to as “lockup release vibration”) and the vibration caused by the release of the fuel cut function (hereinafter referred to as “fuel cut release vibration”) cancel each other. Become. As a result, it is possible to reduce vibrations that occur when releasing the lockup function and the fuel cut function.

  The control means preferably corrects the release timing of the fuel cut function according to the combustion cycle of the engine and the fuel injection method. In this case, the release timing of the fuel cut function can be accurately approximated to a timing delayed by approximately [n + 1/2] period of the drive system resonance period from the release timing of the lockup function.

  Preferably, the control means sets the fuel injection amount after the release of the fuel cut function so that the amplitude of the vibration caused by the release of the fuel cut function is equal to the amplitude of the vibration caused by the release of the lockup function. In this case, since the lock-up release vibration and the fuel cut release vibration act so as to cancel each other out more, it is possible to further reduce the vibration generated when the lock-up function and the fuel cut function are released.

  In addition, when the accelerator operation is performed in a state where the fuel cut function is activated, the control means preferably estimates the drive system resonance period based on the drive system state when the accelerator operation is performed. In this case, the lock-up release vibration and the fuel cut release vibration act to cancel each other in accordance with a drive system state (for example, a gear ratio) that changes when the accelerator operation is performed.

  A vehicle vibration reduction device according to the present invention is a vehicle vibration reduction device for reducing vibration of a vehicle including an automatic transmission having a lockup function and an engine having a fuel cut function, the lockup function and A control means for controlling the fuel cut function is provided. When the lock up function or the fuel cut function is released, the control means uses the vibration caused by the release of either the lock up function or the fuel cut function as the vibration caused by the release of the other. It is characterized by controlling to reduce.

  According to this vehicle vibration reducing device, since either one of the lockup release vibration and the fuel cut release vibration is controlled to be reduced on the other side, the vibration generated when releasing the lockup function and the fuel cut function is reduced. It becomes possible to do.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to reduce the vibration which arises when canceling | releasing a lockup function and a fuel cut function.

1 is a schematic configuration diagram of a vehicle vibration reduction device according to a first embodiment of the present invention. It is a flowchart which shows the process sequence of the vehicle vibration reduction apparatus of FIG. It is a figure which shows the relationship between the time in a process of the vehicle vibration reduction apparatus of FIG. 1, and a counter. It is a figure explaining an example of the control outline | summary of the vehicle vibration reduction apparatus of FIG. It is another figure explaining an example of the control outline | summary of the vehicle vibration reduction apparatus of FIG. It is a schematic block diagram of the vehicle vibration reducing device which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the process sequence of the vehicle vibration reduction apparatus of FIG. It is a figure which shows the relationship between the time in the process of the vehicle vibration reduction apparatus of FIG. 6, a counter, and a crank angle. It is a figure explaining an example of the control outline | summary of the vehicle vibration reduction apparatus of FIG. It is a flowchart which shows the process sequence of the vehicle vibration reduction apparatus which concerns on 3rd Embodiment of this invention. It is a figure explaining an example of the control outline of the vehicles vibration reduction device concerning a 3rd embodiment of the present invention. It is a schematic block diagram of the vehicle vibration reducing device which concerns on 4th Embodiment of this invention. It is a flowchart which shows the process sequence of the vehicle vibration reduction apparatus of FIG. It is a figure explaining an example of the control outline | summary of the vehicle vibration reduction apparatus of FIG. It is another figure explaining an example of the control outline | summary of the vehicle vibration reduction apparatus of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

[First Embodiment]
First, a first embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram of a vehicle vibration reduction device according to the first embodiment of the present invention. As shown in FIG. 1, a vehicle vibration reduction device 1 according to the present embodiment is mounted on a vehicle X such as an automobile to reduce the vibration of the vehicle X, and includes, for example, a CPU, a ROM, a RAM, and the like. An ECU (Electronic Control Unit) 2 as a controller is provided.

  The vehicle X here is a so-called CVT (Continuously Variable Transmission) vehicle. The vehicle X includes at least an engine 11 as a drive source and an automatic transmission 15 having a torque converter 12 and a continuously variable transmission (CVT) 13 as a drive system D. The engine 11 includes a plurality of fuel injectors 11 a for supplying fuel to the engine 11.

  The engine 11 is configured so that fuel supply from the fuel injector 11a can be reduced (cut) by controlling the fuel injector 11a by the ECU 2 in order to improve fuel efficiency when the vehicle X is coasting with the accelerator off, for example. Has been. That is, the engine 11 has a fuel cut function (F / C function).

  The automatic transmission 15 is a speed change mechanism having a function of automatically changing the speed ratio. The torque converter 12 includes a lock-up clutch 12a for engaging (directly connecting) the engine 11 and the continuously variable transmission 13 to enter a lock-up state. The torque converter 12 is configured so that the lockup clutch 12a can be engaged with the lockup clutch 12a by controlling the lockup clutch 12a by the ECU 2 in order to prevent the engine 11 from stalling, for example, when coasting with the accelerator off (locked clutch 12a). Configured to be up). That is, the automatic transmission 15 has a lockup function (L / U function). The continuously variable transmission 13 is connected to drive wheels 16.

  The ECU 2 controls the fuel cut function and the lockup function, and is connected to the fuel injector 11a and the lockup clutch 12a. For example, when the vehicle speed of the vehicle X detected by the vehicle speed sensor 17 is equal to or lower than a predetermined value, the ECU 2 releases the lockup function (L / C release) and the fuel cut function (F / C return). To do. At this time, the release timing of the fuel cut function is set to be delayed from the release timing of the lockup function by [n + 1/2] period (n is an integer of 0 or 1 or more) of the drive system resonance period of the vehicle (details). Is described later).

  In the vehicle vibration reduction device 1 configured as described above, for example, when the vehicle X travels inertially with the accelerator off, the ECU 2 controls the lockup clutch 12a in order to improve fuel efficiency while preventing the engine 1 from stalling. The lockup function is activated and the fuel injector 11a is controlled to activate the fuel cut function. At this time, the ECU 2 performs the following control.

  First, the counter N is initialized to 0. Then, for example, it is determined whether or not the lockup function is released based on the situation such as the hydraulic pressure of the lockup clutch 12 (S1). When the lockup function is released, it is determined whether or not the fuel cut function is operating (S2). If the lockup function has not been released, and if the fuel cut function has not been activated, the processing is terminated. Note that other processes may be adopted instead of the processes of S1 and S2 as long as the process can start the subsequent process when the lockup function is released.

  Subsequently, when the fuel cut function is activated, it is determined whether or not the counter N is 0 (that is, whether or not the control is the first calculation) (S3). If the counter N is not 0, the process proceeds to S6. On the other hand, when the counter N is 0, the drive system resonance period Td is acquired. The drive system resonance period Td is a resonance period in the drive system D of the gear ratio when the lock-up function and the fuel cut function are released when the vehicle X is coasting with the accelerator off, and is obtained based on design values and experimental results. Has been. At the same time, a control calculation frequency f for expressing the count number of the counter N by time (time conversion) is acquired (S4).

Then, based on the drive system resonance period Td and the control calculation frequency f, a counter threshold A (hereinafter also simply referred to as “threshold A”), which is a threshold for deriving the release timing of the fuel cut function, is acquired (S5). Here, as shown in FIG. 3, the threshold A is the number of computations necessary for delaying the drive system resonance period by 1/2 of the timing when the lockup function is released (that is, the number of counters N). The following formula (1) is obtained.
A = f × Td / 2 (1)

  Subsequently, the counter N is incremented (N = N + 1) (S6). Subsequently, when the counter N is equal to or less than the threshold value A, the process proceeds to S1 again (S7). On the other hand, when the counter N is larger than the threshold value A, a cancel command for canceling the fuel cut function is output to the fuel injector 11a to return the fuel injection amount. As a result, the fuel cut function is canceled and the process is terminated (S8).

  FIG. 4 is a diagram for explaining an example of a control outline of the vehicle vibration reduction device of FIG. In the figure, a solid line indicates a value obtained by the vehicle vibration reduction device 1 of the present embodiment, and a broken line indicates a conventional vehicle vibration reduction device that releases the lockup function and the fuel cut function simultaneously (hereinafter simply referred to as “conventional device”). ). The longitudinal acceleration is the acceleration of the vehicle X, and the forward acceleration is positive and the backward acceleration is negative. These are the same in FIG. Since the transmission model from the drive system D to the drive wheel 16 can be approximated by a second-order lag model with respect to the input, the behavior of the longitudinal acceleration here is shown as a step response of the second-order lag system.

  In the graph on the upper left in the figure, from when the lockup function is activated and the lockup state is 100% (the lockup clutch 12a is completely engaged), this function is being released (disengaged), and at time t0. It is completely released (disengaged) at that time. Also, from this time t0, that is, from the release timing t0 when the lockup function is completely released, the longitudinal acceleration of the vehicle X due to the release of the lockup function (lockup release vibration: hereinafter referred to as “L / U longitudinal acceleration”) It can be seen that it fluctuates with the drive system resonance period.

  Here, as shown in the lower left graph in the figure, in the conventional apparatus, the fuel cut function is released at the release timing t0 when the lockup function is released, and the fuel injection amount is increased. Therefore, the variation in the longitudinal acceleration of the vehicle X (fuel cut cancellation vibration: hereinafter referred to as “F / C longitudinal acceleration”) due to the cancellation of the fuel cut function is in phase with the variation in the L / U longitudinal acceleration. Therefore, as shown in the graph on the right side of the figure, the total longitudinal acceleration generated in the vehicle X is amplified and increased.

  On the other hand, in the present embodiment, the fuel cut function is released with a delay of half the drive system resonance period (Td / 2) from the release timing t0 of the lockup function. That is, the release timing of the fuel cut function is set so as to be delayed by a half cycle of the drive system resonance cycle with respect to the release timing of the lockup function. Therefore, the F / C longitudinal acceleration as a so-called acceleration shock has an opposite phase to the L / U longitudinal acceleration, and the fluctuation of the total longitudinal acceleration generated in the vehicle X is offset and reduced.

  FIG. 5 is another diagram for explaining an example of the control outline of the vehicle vibration reducing device of FIG. In the example shown in FIG. 5, the vehicle X has an accelerator pedal opening degree of 0% (accelerator Off), the lockup function is activated and the lockup state is 100%, and the fuel cut function is activated at time 0. The vehicle is coasting with the fuel injection amount cut. Then, the vehicle speed and the longitudinal acceleration are gradually decreased (period P11). For example, when the vehicle speed becomes a predetermined value or less, a lock-up function release command is issued and the lock-up state is being released (period P12). The lockup function is released (period P13).

  Here, in this embodiment, the release timing for releasing the fuel cut function and returning the fuel injection amount is half the drive system resonance period from the release timing t0 when the lockup function is 0% and the lockup function is completely released. The delayed time (t0 + Td / 2) is set. Therefore, the F / C longitudinal acceleration fluctuation and the L / U longitudinal acceleration fluctuation work in opposite phases and cancel each other. As a result, in this embodiment, the fluctuation of the longitudinal acceleration is reduced with respect to the conventional device. That is, the vibration caused by the release of one of the lockup function and the fuel cut function is reduced by the vibration caused by the other release.

  As described above, according to this embodiment, the fluctuations in the L / U longitudinal acceleration and the fluctuations in the F / C longitudinal acceleration act so as to cancel each other. It is possible to reduce acceleration fluctuation (vibration). That is, by controlling each of the release timing of the fuel cut function and the release timing of the lockup function, it is possible to reduce vibration due to the release of these functions.

  Note that in a CVT vehicle such as the vehicle X of the present embodiment, the resonance frequency of the drive system D is low due to its structure, and unpleasant vibration is likely to occur. Therefore, the present embodiment that can reduce fluctuations in the longitudinal acceleration that occurs when releasing the lockup function and the fuel cut function is particularly effective.

  It is also conceivable that the fuel injection amount is increased by a certain amount during the operation of the fuel cut function, thereby reducing the torque step when releasing the fuel cut function and reducing fluctuations in the longitudinal acceleration. However, in this case, since the L / U longitudinal acceleration and the F / C longitudinal acceleration are superimposed so as to increase, the longitudinal acceleration variation still remains. In this respect, in the present embodiment, the L / U longitudinal acceleration and the fluctuation of the F / C longitudinal acceleration are in opposite phases and act so as to cancel each other, so that the present embodiment can be said to be effective.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the description of the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 6 is a schematic configuration diagram of a vehicle vibration reducing device according to the second embodiment of the present invention. The vehicle vibration reducing device of the present embodiment is different from the above-described vehicle vibration reducing device 1 in that logic for correcting the release timing of the fuel cut function according to the combustion cycle of the engine 11 and the fuel injection method is incorporated. ing. As shown in FIG. 6, in the vehicle vibration reducing device 20, a crank angle sensor 21 that detects a crank angle and a crank angular speed of the engine 11 is connected to the ECU 2. The engine 11 is a simultaneous injection method in which fuel is simultaneously injected into all cylinders when the crank angle is 0 deg.

  Here, in the vehicle vibration reducing device 1, when the counter N reaches the threshold value A, a fuel cut function release command is output to the fuel injector 11 a, the fuel injection amount is restored, and the fuel injected with this fuel injection amount The fuel cut function is released by burning. Therefore, the release timing of the fuel cut function is limited in terms of the combustion cycle of the engine 11 and the fuel injection method.

  Therefore, in some cases, when the fuel cut function is canceled before the counter N reaches the threshold value A, the fuel cut function is released at a timing delayed from the lockup function release timing t0 by half of the drive system resonance period. The timing may be close. That is, referring to FIG. 8, for example, when the time t1 is closer to the time Td / 2 than the time t2, the fuel cut function is released at the previously released release timing fc2 as compared with the case where the fuel cut function is released at the release timing fc2. It may be preferable to deactivate the function.

  Therefore, in this embodiment, as shown in FIG. 7, after obtaining the threshold value A in S5, the calculation margin value A1 is set (S21). This calculation margin value A1 defines a time margin for performing a calculation required before canceling the fuel cut function (that is, a calculation for selecting which combustion cycle to cancel the fuel cut function in repeated combustion cycles). This is the setting value.

  Subsequently, it is determined whether or not “counter N = threshold A−calculation margin value A1” (S22). If “counter N = threshold A−calculation margin value A1” is not established, the process proceeds to S6. On the other hand, if “counter N = threshold A—calculation margin value A1”, the crank angle sensor 21 causes the crank angular speed dAc and crank The angle Ac is acquired (S23). When the engine 11 is 4 strokes and 1 cycle, the crank angle Ac is 0 to 720 deg.

Subsequently, the crank angle Acf at the future release timing of the fuel cut function is estimated based on the crank angular velocity dAc and the crank angle Ac (S24). Specifically, the crank angle Acf is calculated based on the following equation (2).
Acf = (dAc × A1 / f + Ac) (crank angle for one cycle)
The remainder after dividing by (2)

Subsequently, it is determined whether or not correction is necessary at the release timing of the fuel cut function. Specifically, when the estimated crank angle Acf is 360 degrees or more, the process proceeds to S6 as it is (S25). On the other hand, when the crank angle Acf is smaller than the estimated crank angle Acf, the advance calculation value A3 is calculated as shown in the following expression (3) in order to advance the release timing of the fuel cut function for the reason described above (S26). ). Then, as shown in the following equation (4), the threshold value A is corrected with the preceding calculation value A3, and the process proceeds to S6 (S27).
A3 = Acf / dAc × f (3)
A = A−A3 (4)

  FIG. 8 is a diagram illustrating a relationship among time, a counter, and a crank angle in the processing of the vehicle vibration reducing device of FIG. 6, and FIG. 9 is a diagram illustrating an example of a control outline of the vehicle vibration reducing device of FIG. In the vehicle vibration reduction device 20, as shown in FIG. 8, because of the combustion cycle of the engine 11 and the fuel injection method, the feasible release timings of the fuel cut function are the release timings fc1 and fc2. On the other hand, the ideal target release timing th is a timing delayed by half (Td / 2) the drive system resonance period from the release timing t0 when the lockup function is released.

  In the example shown in FIG. 9, the release timing of the fuel cut function is closer to the ideal target release timing th at the release timing fc1 than at the release timing fc2. Therefore, the fluctuation of the F / C longitudinal acceleration at the release timing fc1 (solid line in the figure) is more of the fluctuation of the L / U longitudinal acceleration than the fluctuation of the F / C longitudinal acceleration at the release timing fc2 (broken line in the figure). The phase is approaching.

  Therefore, in this embodiment, the release timing of the fuel cut function is advanced and the release timing fc1 is selected, and the fuel cut function is released at this release timing fc1. As a result, the phase shift is small with respect to the opposite phase of the fluctuation of the L / U longitudinal acceleration, and the fluctuation of the total longitudinal acceleration generated in the vehicle X is reduced.

  As described above, also in this embodiment, the above-described effect of reducing the fluctuation (vibration) of the longitudinal acceleration that occurs when the lockup function and the fuel cut function are canceled is achieved.

  Further, in the present embodiment, as described above, the threshold value A is corrected by the advance calculation value A3 for increasing the release timing of the fuel cut function. That is, the release timing of the fuel cut function is corrected according to the combustion cycle of the engine and the fuel injection method. Therefore, although the release timing of the fuel cut function is limited depending on the combustion cycle of the engine 11 and the fuel injection method, the ideal timing (delayed by 1/2 of the drive system resonance cycle from the release timing of the lockup function) Timing). As a result, it is possible to suppress the remaining L / U longitudinal acceleration and F / U longitudinal acceleration that are offset from each other, and to reduce fluctuations in longitudinal acceleration that occur when the lockup function and the fuel cut function are canceled. It becomes possible to raise.

  In the present embodiment, as described above, the fuel injection method is the simultaneous injection method, and the correction for selecting the combustion cycle for realizing the fuel cut function cancellation is performed at the release timing. However, the present invention is not limited to this. Is not to be done.

  For example, each cylinder of the engine 11 is divided into a plurality of groups according to the ignition order, and a group injection method is performed in which fuel injection is performed in accordance with the intake process for each group, and a group that realizes release of the fuel cut function is selected based on the combustion cycle. Such correction may be performed. In addition, for example, an independent injection system that performs fuel injection independently in accordance with the suction process of each cylinder of the engine 11 is performed, and correction is performed so that a cylinder that realizes the release of the fuel cut function is selected based on the combustion cycle. It may be broken.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In the description of the present embodiment, differences from the first embodiment will be mainly described.

  The vehicle vibration reduction device of the present embodiment has a fuel cut function with respect to the vehicle vibration reduction device 1 described above so that the generation gain (amplitude) of F / C longitudinal vibration is equal to the generation gain of L / U longitudinal acceleration. The difference is that the fuel injection amount after release is set.

  That is, in the vehicle vibration device of this embodiment, as shown in FIG. 10, when the counter N is larger than the threshold A (Yes in S7), the peak gain C of the L / U longitudinal acceleration is estimated (S31). . Specifically, the L / U longitudinal acceleration is obtained based on theoretical or experimental data, and the negative peak gain (maximum) at the time of 3/4 period of the drive system resonance period Td in the fluctuation of the L / U longitudinal acceleration. Amplitude) is stored as peak gain C.

  Subsequently, based on the engine model obtained by modeling the engine 11 and the map of the fuel injection amount, the fuel injection that generates the F / C longitudinal acceleration that causes the fluctuation having the plus-side peak gain having the same absolute value as the peak gain C. The amount D is calculated (S32). Then, fuel of the fuel injection amount D is injected from the fuel injector 11a. As a result, the fuel cut function is canceled and the process is terminated (S33).

  FIG. 11 is a diagram for explaining an example of the control outline of the vehicle vibration reducing device according to the third embodiment of the present invention. In the figure, a solid line indicates a value obtained by the vehicle vibration reducing device of the present embodiment, and a broken line indicates a value obtained by a normal vehicle vibration reducing device. As shown in FIG. 11, in a normal vehicle vibration reduction device, the fuel injection amount after the release of the fuel cut function is set to maintain the idling of the engine 11.

  On the other hand, in the vehicle vibration reducing device of the present embodiment, as described above, the fuel injection amount after the release of the fuel cut function is made larger than the idling maintenance amount and is equal to the peak gain C plus side peak gain The fuel injection amount D is such that the F / C longitudinal acceleration is generated so as to vary. As a result, the L / U longitudinal acceleration and the F / C longitudinal acceleration have the same generated gain and are overlapped in opposite phases. Therefore, in this embodiment, the variation in the L / U longitudinal acceleration and the variation in the F / C longitudinal acceleration work so as to cancel each other out further, and the variation in the total longitudinal acceleration generated in the vehicle X is further reduced. It will be.

  As described above, also in this embodiment, the above-described effect of reducing the fluctuation (vibration) of the longitudinal acceleration that occurs when the lockup function and the fuel cut function are canceled is achieved.

  Further, in the present embodiment, as described above, the lock-up is performed in order to cancel the fuel cut function so that the fuel injection amount D is not excessive or insufficient in order to cancel the fluctuation of the L / U longitudinal acceleration after the cancellation. It is possible to further reduce the fluctuation of the longitudinal acceleration that occurs when the function and the fuel cut function are canceled.

  The “equal generation gain” in the present embodiment includes not only completely equal gains but also substantially equal gains.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. In the description of the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 12 is a schematic configuration diagram of a vehicle vibration reducing device according to the fourth embodiment of the present invention. In the vehicle vibration reducing device of the present embodiment, in contrast to the above-described vehicle vibration reducing device 1, when the driver turns on the accelerator when the fuel cut function is activated, the drive system resonance period is based on the state of the drive system D at that time. It is different in that the logic to estimate is expected.

  As shown in FIG. 12, in the vehicle vibration reduction device 40 of the present embodiment, an accelerator sensor 41 that detects the accelerator On or Off is connected to the ECU 2. Further, the ECU 2 is connected to the continuously variable transmission 13 and receives a signal relating to the gear stage of the drive system D.

  In this vehicle vibration reducing device 40, as shown in FIG. 13, when the fuel cut function is operating (Yes in S2), when the accelerator sensor 41 does not detect the accelerator Off, the current drive system gear stage E Is detected (S41, 42). Subsequently, the drive system resonance period Td ′ is estimated and acquired based on the detected drive system gear stage E using, for example, a drive system model or a drive system gear stage map (S43).

Then, as shown in the following formula (5), the threshold A, which is a threshold for deriving the release timing of the fuel cut function, is acquired (updated) again based on the drive system resonance period Td ′ and the control calculation frequency f ( S44). Thereafter, the process proceeds to S6.
A = f × Td ′ / 2 (5)

  FIG. 14 is a diagram for explaining an example of a control outline of the vehicle vibration reduction device of FIG. In the example in the figure, the accelerator is turned on when a lockup function release command is issued. In addition, the solid line in the figure shows the value based on the drive system resonance period obtained from the drive system gear stage E in the state of the accelerator On, that is, the value obtained by the vehicle vibration reducing device 40 of the present embodiment. The broken line in the figure indicates a value based on a normal vehicle vibration reduction device, that is, a value based on the drive system resonance period obtained from the drive system gear stage E in the accelerator-off state. These are the same in FIG.

  As shown in FIG. 14, when the accelerator is turned on when the fuel cut function is activated, the drive system gear stage E changes and the gear ratio changes, so the drive system resonance period that depends on this gear ratio also changes. . In this regard, in a normal vehicle vibration reduction device, the change in the drive system resonance cycle is not taken into account, so the fuel cut function is released after being shifted from the half cycle of the fluctuation of the L / U longitudinal acceleration. ing. Accordingly, the total longitudinal acceleration generated in the vehicle X still has fluctuations due to such deviation.

  On the other hand, in this embodiment, since the drive system resonance period can be changed with the change of the drive system gear stage E, the fuel cut function is accurately canceled at the time of 1/2 period of the fluctuation of the L / U longitudinal acceleration. It is possible to do. As a result, the L / U longitudinal acceleration fluctuations and the F / C longitudinal acceleration fluctuations work reliably so as to cancel each other, and the total longitudinal acceleration generated in the vehicle X is reliably reduced.

  FIG. 15 is another diagram for explaining an example of the control outline of the vehicle vibration reducing device of FIG. In the example shown in FIG. 15, at the time tp when the lockup function release command is issued, the drive system gear stage E is changed by changing to the accelerator On, the speed ratio is changed, and the drive system resonance period is changed. ing. In this regard, in this embodiment, the release timing of the lockup function is set to a time point (t0 + Td ′ / 2) based on the drive system resonance period Td ′ in consideration of such a change. Therefore, the F / C longitudinal acceleration and the L / U longitudinal acceleration are in opposite phases and reliably operate so as to cancel each other with accuracy, and fluctuations in longitudinal acceleration are reliably reduced.

  As described above, also in the present embodiment, the above-described effect of reducing fluctuations in the longitudinal acceleration that occurs when the lockup function and the fuel cut function are canceled is achieved.

  In the present embodiment, as described above, when the accelerator is turned on in the state where the fuel cut function is activated, the drive system resonance period Td ′ is estimated based on the state of the drive system D at this time. Therefore, the fluctuation of the L / U longitudinal acceleration and the fluctuation of the F / C longitudinal acceleration act so as to cancel each other in accordance with the drive system state that changes when the accelerator operation is performed. As a result, even when the accelerator operation is performed in a state where the fuel cut function is activated, it is possible to reliably reduce fluctuations in the longitudinal acceleration.

  The preferred embodiments of the present invention have been described above, but the vehicle vibration reducing device according to the present invention is not limited to the vehicle vibration reducing 1, 20, 40 according to the embodiments, and is described in each claim. It may be modified without changing the gist or applied to other things.

  For example, in the above embodiment, the presence or absence of the lockup function is determined based on the situation such as the hydraulic pressure of the lockup clutch 12, but a lockup sensor that detects the engagement state of the lockup clutch 12a is provided. Whether or not the lockup function is activated may be determined from the detection result of the lockup sensor.

  In the above embodiment, the automatic transmission 15 has the continuously variable transmission 13, but the automatic transmission 15 is not limited to this. For example, the drive system gear stage is automatically and stepwise. You may have the transmission etc. which switch E. That is, the vehicle X may not be a CVT vehicle but may be an AT vehicle.

  Further, in the above embodiment, the release timing of the fuel cut function is delayed from the release timing of the lockup function by ½ period of the drive system resonance period, but [n + 1/2] period (n is an integer). You can delay. Note that the ½ period includes not only ½ period but also approximately ½ period (the same applies to the [n + ½] period).

  DESCRIPTION OF SYMBOLS 1,20,40 ... Vehicle vibration reduction apparatus, 2 ... ECU (control means), 11 ... Engine, 15 ... Automatic transmission, X ... Vehicle.

Claims (5)

A vehicle vibration reduction device for reducing vibration of a vehicle including an automatic transmission having a lockup function and an engine having a fuel cut function,
Control means for controlling the lock-up function and the fuel cut function,
When releasing the lockup function and the fuel cut function, the control means sets the release timing of the fuel cut function from the release timing of the lockup function to approximately [n + 1/2] of the drive system resonance period of the vehicle. A vehicle vibration reduction device that is set to be delayed by a period (n is an integer).   2. The vehicle vibration reduction device according to claim 1, wherein the control means corrects the release timing of the fuel cut function according to a combustion cycle and a fuel injection method of the engine.   The control means sets the fuel injection amount after the release of the fuel cut function so that the amplitude of vibration caused by the release of the fuel cut function is equal to the amplitude of vibration caused by the release of the lockup function. The vehicle vibration reduction device according to claim 1 or 2.   When the accelerator operation is performed in a state where the fuel cut function is activated, the control means estimates the drive system resonance period based on a drive system state when the accelerator operation is performed. The vehicle vibration reduction device according to any one of claims 1 to 3. A vehicle vibration reduction device for reducing vibration of a vehicle including an automatic transmission having a lockup function and an engine having a fuel cut function,
Control means for controlling the lock-up function and the fuel cut function,
The control means, when releasing the lockup function and the fuel cut function, controls to reduce the vibration caused by the release of one of the lockup function and the fuel cut function by the vibration caused by the other release. A vehicle vibration reduction device characterized by the above.

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