JP3417715B2 - Powertrain controls - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for a power train having an engine and an automatic transmission.

[0002]

2. Description of the Related Art Generally, when the engine speed falls below a predetermined value due to a deceleration operation such as releasing an accelerator pedal, there is a risk of engine misfire. For this reason, conventionally, in order to prevent the engine speed from dropping excessively as described above, when the engine speed drops below a predetermined value, a preset target speed (generally approximately equal to the above-mentioned predetermined value In order to bring the engine rotational speed closer to the engine rotational speed), feedback control is performed such as adjusting the engine torque by changing the intake air amount.

[0003]

In a power train having an automatic transmission, generally, the automatic transmission automatically shifts down as the vehicle speed decreases due to the deceleration operation (for example, Japanese Patent Laid-Open No. 2-245571). See the gear shift map in FIG. Therefore, in the device in which the engine speed feedback control is performed as described above, the target speed No, the turbine speed Ntb that is the output shaft speed of the automatic transmission, and the intake air amount Q corresponding to the engine torque are set. The relationship of is theoretically as shown in the time chart of FIG.

That is, the turbine rotational speed Ntb is temporarily increased during downshifting, but is generally gradually decreased, and the engine rotational speed behaves similarly. Therefore, when the control to bring the engine speed closer to the target speed No is executed, the intake air amount Q is gradually increased during the normal operation other than the downshift, and the downshift is performed, as shown by the broken line in the figure. Sometimes you should lose weight.

However, in actuality, there is a considerable response delay before the turbine speed Ntb actually starts to increase after the shift down is started and further the engine speed starts to increase. Therefore, actually, the intake air amount Q is increased for a while after the shift down is started, and the peak of the intake air amount Q and the peak of the engine torque are reached during the shift down.

In other words, since a downshift operation is performed when the engine torque increases, a large shift shock will occur when the clutch or the like for this downshift is engaged. Especially in the driving range where the vehicle speed is sufficiently low,
Increase in engine torque because the engine torque is effectively transmitted to the vehicle side through the automatic transmission even if the throttle valve is fully closed (that is, the engine torque positively contributes to driving the wheels). The increase in gear shift shock due to is marked.

In view of such circumstances, the present invention is a device for feedback controlling the engine speed in a low engine speed region, and is a power train control device capable of effectively reducing a shift shock due to a downshift in the above region. The purpose is to provide.

[0008]

According to the present invention, an engine speed detecting means for detecting an engine speed and an engine speed which is preset when the detected engine speed falls below a predetermined value. In a power train control device including an engine torque adjusting unit that changes an engine torque to perform feedback control to bring the engine speed closer to a target rotation speed, an automatic transmission provided in the power train downshifts with a decrease in vehicle speed. The engine torque adjusting means may be provided with an engine torque limiting means for inputting a limitation command for an engine torque increasing operation (claim 1).

More specifically, as the engine torque limiting means, feedback inhibiting means for inputting an inhibition command for feedback control of the engine speed to the engine torque adjusting means at the time of downshifting accompanying a decrease in vehicle speed is preferable. There is (claim 2).

More preferably, the engine torque adjusting means performs feedback control of the engine speed only when the throttle valve is fully closed (claim 3).
In this case, a vehicle speed detecting means is provided, and the engine torque adjusting means is provided only when the detected vehicle speed is less than the vehicle speed that is substantially equal to the minimum value of the vehicle speed that does not contribute to the driving of the wheels when the throttle valve is fully closed. More preferably, the engine torque limiting means is configured to input the limit command for the engine torque increasing operation (claim 4).

Further, the automatic transmission is provided with a speed ratio detecting means for detecting a speed ratio and a speed ratio predicting means for predicting a speed ratio after downshifting. The lower the speed ratio based on the speed ratio, the lower the engine ratio. The engine torque adjusting means is configured to correct the torque adjustment amount to a higher value, and the engine torque adjustment amount is corrected based on the detected speed ratio during the feedback control and based on the predicted speed ratio during feedback control restriction. By configuring the engine torque adjusting means so as to achieve the above, a more excellent effect as described below can be obtained (claim 5).

As the engine torque adjusting means, intake air amount adjusting means (claim 6) for adjusting the intake air amount of the engine and ignition timing adjusting means (claim 8) for adjusting the ignition timing of the engine are preferable. In this case, if the intake air amount adjusting means and the ignition timing adjusting means are configured so as to maintain the actual intake air amount at the time of inputting the limit command at the intake air amount or the ignition timing corresponding to the target rotation speed, It is preferable (claims 7 and 9).

[0013]

According to the apparatus of the present invention, in the low engine speed range where the engine speed is equal to or lower than a predetermined value, the engine speed is adjusted by adjusting the engine torque during a normal shift-down operation due to a decrease in vehicle speed. By performing the feedback control to bring the engine speed close to the target engine speed, it is possible to prevent the engine speed from dropping excessively. On the other hand, when the downshift is performed due to the decrease in the vehicle speed even in the low speed region, the engine torque increasing operation for controlling the engine speed is limited, and the shift shock accompanying the downshift is reduced accordingly.

Particularly, in the apparatus according to the second aspect, the feedback control of the engine speed is prohibited at the time of downshifting due to the decrease of the vehicle speed, so that the shift shock at the downshifting is further reduced.

According to the third aspect of the present invention, when the throttle valve is fully closed even if the engine speed is below a predetermined value,
That is, the feedback control of the engine speed is performed only when the driver has no intention of accelerating. Therefore, the situation in which the engine speed is controlled to approach the target speed against the driver's will does not occur.

In the apparatus according to claim 4, the actual vehicle speed is
Only when the engine torque is less than the vehicle speed that is substantially equal to the minimum value of the vehicle speed that does not contribute to the driving of the wheels when the throttle valve is fully closed, that is, only when the engine torque is in an operating state in which an increase in the engine torque directly leads to a shift shock ,
When the engine torque increasing operation for controlling the engine speed is limited, and in other cases, that is, when there is almost no effect on the shift shock due to the increase of the engine torque, the engine speed is feedback-controlled as usual. .

In the above power train, the lower the speed ratio in the automatic transmission (that is, the higher the torque ratio), the more the drive energy of the engine is consumed by the torque converter, so that the same engine speed can be ensured.
A lower speed ratio requires a larger engine torque.
Therefore, it is appropriate that the lower the speed ratio, the higher the adjustment amount of the engine torque is corrected.

Here, in the apparatus according to the fifth aspect, the correction of the adjustment amount is based on the current detected speed ratio during feedback control, and when the feedback control is limited, the predicted speed ratio after downshifting (that is, the current detected speed ratio). Since the speed is lower than the speed ratio, the engine torque adjustment amount is set lower when feedback control is limited, and this correction also sets the target engine speed after feedback limitation is released. It can be brought closer to the rotation speed quickly.

According to the sixth and eighth aspects of the present invention, the engine torque is adjusted by changing the intake air amount of the engine and the ignition timing, thereby controlling the engine speed.

In the device according to the seventh and ninth aspects, when the limit command is input, the actual intake air amount and the ignition timing are maintained at the intake air amount corresponding to the target rotational speed.
The engine torque is set in consideration of the target rotation speed while prohibiting the feedback.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

The power train shown in FIG.
And an automatic transmission AT. The automatic transmission AT is
A torque converter 2, a transmission mechanism (multi-stage transmission mechanism in this embodiment) 10, and a hydraulic control circuit 30 are provided.
The torque converter 2 has an input shaft, that is, a pump shaft, connected to an output shaft of the engine E, and an output shaft, that is, a turbine shaft, connected to an input shaft of the speed change mechanism 10. It is connected to the wheels via a differential gear or the like.

The speed change mechanism 10 includes various friction elements (clutch, brake), and changes the power transmission path by switching these friction elements on and off to switch the shift speed. The release is controlled by the hydraulic control device 30.

The intake system of the engine E is provided with an air flow meter 53, a throttle valve 54, a surge tank 55, etc. in this order from the upstream side. A spark plug 56 is provided in each cylinder of the main body of the engine E.
6 is connected to a common distributor 57.

The upstream side and the downstream side of the throttle valve 54 are ISC (idle speed control).
This ISC passage 5 is bypassed via passage 58
An ISC valve 59 is provided in the middle of 8, and the intake air amount Q can be adjusted by opening and closing the ISC valve 59 even when the throttle valve 54 is fully closed.

This device includes a vehicle speed sensor 61 for detecting a vehicle speed V and an opening of the throttle valve 54 (throttle opening) TVO.
A throttle sensor 62 for detecting the engine speed, an engine speed (rotation speed of the engine output shaft per unit time) Ne, an engine speed sensor 63 for detecting Ne, a turbine speed (the rotation speed of the turbine shaft of the torque converter 2 per unit time)
Various sensors such as a turbine speed sensor 64 for detecting Ntb are provided, and detection signals of these are input to an ECU (engine control unit) 70.

The control unit 70 is provided with gear shift control means 71, feedback inhibiting means 72, speed ratio calculating means 73, and intake air amount adjusting means 74 as shown in FIG. There is.

The shift control means 71 outputs an appropriate control signal to the shift solenoid valve 31 of the hydraulic control circuit 30 on the basis of a shift map using the vehicle speed V and the throttle opening TVO as parameters to shift up the shift mechanism 10. In addition to executing the shift down, the duty solenoid valve 32 is appropriately output a control signal to control the line pressure.

For downshifting, the shift control means 71, for example, in the D range, when the throttle opening TVO increases, when the vehicle speed decreases,
When the shift lever is operated, the shift-down flag sdf is switched from 0 to 1 and the transmission mechanism 10 is downshifted for a predetermined time required for switching.

The feedback inhibiting means 72 has the above-mentioned
In this case, when the vehicle speed V is reduced and the vehicle speed V is downshifted, and the vehicle speed V is less than the predetermined value α, the speed ratio calculation means 73 only during the period when the downshift flag sdf is 1. Also, a feedback inhibition command is input to the intake air amount adjusting means 74. Here, the predetermined value α is set to a vehicle speed that is substantially equal to the minimum vehicle speed at which the output torque of the engine E does not contribute to the driving of the wheels (that is, the engine brake acts) when the throttle valve 54 is fully closed. ing.

The speed ratio calculating means (speed ratio detecting means and speed ratio predicting means) 73 is provided with the feedback prohibiting means 72.
During the period when the feedback prohibition command is not input from the engine speed sensor 63 and the turbine speed sensor 64, the current speed ratio e (= Ntb / Ne) is detected.
On the other hand, in the period in which the feedback prohibiting command is input from the feedback prohibiting means 72, the speed ratio e _f after the shift down is completed in this period.
For predictive calculation.

In the intake air amount adjusting means 74, the throttle valve 54 is fully closed and the detected engine speed Ne is a predetermined value N1.
In the following cases, the feedback inhibiting means 72
During the period in which the feedback prohibition command is not input from, the opening degree of the ISC valve 59 is adjusted so as to adjust the intake air amount Q so that the engine speed Ne approaches the target speed No that is a value close to the predetermined value N1. (That is, feedback control of the engine speed Ne is performed by adjusting the engine torque), while maintaining the intake air amount Q at a constant value during the period in which the feedback prohibiting command is input from the feedback prohibiting means 72. Is.

The magnitude of this constant value will be described later.

Next, a specific engine speed control operation performed by the control unit 70 will be described with reference to the flowcharts of FIGS. 3 and 4.

First, the throttle opening TVO and the engine speed Ne are taken in, and the throttle opening TVO is 0% (that is, the throttle valve is fully closed; Y in step S1).
ES) and when the engine speed Ne is equal to or lower than the predetermined value N1 (YES in step S2), the engine speed N1 is controlled by operating the ISC valve 59 (that is, by adjusting the intake air amount Q and thus the engine torque). To execute.

In controlling the engine speed, a characteristic of the apparatus of this embodiment is that the vehicle speed V is equal to or higher than a predetermined value α (that is, the engine torque is not contributing to the driving of the wheels; NO in step S3), Alternatively, when the downshift flag sdf is not 1 (that is, when the downshift is not performed; NO in step S4), feedback control of the engine speed N1 is performed (steps S5 to S8) while the vehicle speed V is set to a predetermined value. When the value is less than α (that is, the engine torque contributes to the driving of the wheels; YES in step S3) and the downshift flag sdf is 1 (that is, the downshift is performed due to the decrease in the vehicle speed. If yes; Y in step S4
In ES, the feedback control of the engine speed N1 is prohibited, and the control for keeping the intake air amount Q constant (no feedback control) is performed (step S9).

In the former feedback control, first, the engine speed sensor 63 and the turbine speed sensor 64.
The current speed ratio e (= Ntb / Ne) is calculated from the detection result by (step S5), and the deviation (control deviation) Δ between the current detected engine speed Ne and the target speed No.
N is calculated (step S6). Then, the speed ratio correction coefficient K, which is a function of the speed ratio e, is added to the basic intake air amount Qo.
The target intake air amount Q is set by multiplying (e) and adding the feedback correction amount f (ΔN) which is a function of the control deviation ΔN to the target intake air amount Q (step S7). A control signal is output to the actuator of the ISC valve 59 (step S8).

Here, as shown in FIG. 5A, the basic intake air amount Qo is required to obtain the target rotational speed No when the speed ratio e is 0.98 (almost neutral). The intake air amount is set. Therefore, the higher the target rotation speed No, the larger the basic intake air amount Qo is set. Further, the speed ratio correction coefficient K (e) is shown in FIG.
As shown in, when the speed ratio e is about 1.0 or more, 1.0
In the region where the speed ratio e is lower than this, the speed ratio e is set to a large value that is small. Therefore, the smaller the speed ratio e, the larger the intake air amount Q is set.

The contents of the latter no-feedback control (step S9) are as shown in FIG. First, the turbine speed Ntbf after the current downshift is completed is predicted from the current turbine speed Ntb (step S1).
0). The predicted turbine speed Ntb can be calculated by the following equation using the gear ratio Rf of the transmission mechanism 10 after downshifting and the gear ratio Ro of the transmission mechanism 10 before downshifting.

[0040]

[Formula 1] Ntbf = Ntb × (Rf / Ro) Next, the predicted speed ratio e _f (= Ntbf / No) after completion of the downshift is calculated based on the predicted turbine speed Ntb (step S11). . Then, in the same manner as described above, the basic intake air amount Q determined based on the target rotation speed No.
o in the Figure 5 (b) at the indicated speed ratio correction coefficient K (e _f)
And the target intake air amount Q (step S
12), so as to maintain this target intake air amount Q from beginning to end I
A control signal is output to the actuator of the SC valve 59 (step S13).

As described above, in this device, even when the predetermined engine speed feedback condition is satisfied, when the downshift is executed due to the decrease of the vehicle speed in the low speed running state, the engine speed is synchronized with this. Since the engine torque increasing operation for control is limited, there is an effect that the shift shock accompanying the downshift can be significantly reduced.

FIG. 6 (a) shows the behavior of the turbine speed Ntb and the intake air amount Q in the conventional device, and FIG. 6 (b).
Shows the behavior of the turbine speed Ntb and the intake air amount Q in the apparatus of this embodiment.

As shown in FIG. 3A, in the conventional device,
Since the feedback control is always performed in the low rotation speed region, the intake air is delayed due to the response delay of the feedback control even when the turbine rotation speed Ntb and the engine rotation speed Ne actually increase at the time of downshifting due to the vehicle speed decrease. The amount Q continues to increase (that is, the engine torque continues to increase), and when the engine torque increases, there is engagement or disengagement of the friction element for downshifting, which causes a significant shift shock. However, in this embodiment, as shown in FIG. 2B, the shift shock is significantly reduced because the intake air amount Q and the engine torque are prohibited from increasing at the same time when the downshift is started. It becomes possible to do.

Further, in this embodiment, the speed ratio correction coefficient K (e) is introduced so that the lower the actual speed ratio e (that is, the higher the torque ratio and the energy loss in the torque converter 2 during the feedback control). The higher),
The lower the expected speed ratio e _f after the shift down when the feedback prohibition, since so as to increase the intake air quantity Q, is it possible to bring the engine speed Ne more rapidly to the target speed No There is. Moreover, since the expected speed ratio e _f after the shift-down is lower than the actual speed ratio e, the case of performing the correction, so that the target intake air amount Q is set lower than when the feedback control at the time of the feedback prohibit .

Next, a second embodiment will be described with reference to FIG. In this embodiment, an ignition timing adjusting means 75 is provided as an engine torque adjusting means in place of the intake air amount adjusting means 74 in the first embodiment. The ignition timing adjusting means 75 adjusts the ignition advance angle Ig of each spark plug 56 by outputting a control signal to the distributor 57.

Also in this configuration, the target intake air amount Q, the basic intake air amount Qo, and the speed ratio correction coefficient K (e) in the first embodiment are set to the target ignition advance Ig, the basic ignition advance Igo, and the speed ratio, respectively. By replacing the correction coefficient K (Ig) with the control operation shown in the flowcharts of FIGS. 3 and 4, the same effect as that of the first embodiment can be obtained.

The present invention is not limited to the above embodiments, and the following modes can be taken as examples.

(1) In the above embodiment, the engine speed feedback control is completely prohibited at the time of downshifting due to the decrease in vehicle speed. However, instead of this, the increase amount of the engine torque by the feedback control is kept below a certain value. By limiting the shift shock, it is possible to reduce the shift shock.

(2) In the present invention, it is not always necessary to fully close the throttle valve as a feedback execution condition. However, if the above feedback control is executed only when the throttle valve is fully closed, it is possible to ensure that the engine speed will be close to the target speed despite the driver's intention to accelerate. Can be prevented.

(3) Regarding the feedback limiting condition,
It is also possible to determine whether or not the feedback limitation is possible based on whether or not the shift down is executed without the condition based on the vehicle speed. However, only when the actual vehicle speed V is less than the vehicle speed that is substantially equal to the minimum value of the vehicle speed at which the engine torque is not transmitted to the wheel side when the throttle valve is fully closed as in the above embodiment, that is, the engine torque If the engine torque increasing operation is limited only when the increase greatly affects the shift shock, the vehicle speed is relatively high and the increase in engine torque has almost no effect on the shift shock. When the performance is low, it is possible to bring the engine speed close to the target speed with high accuracy by the usual feedback control.

[0051]

As described above, according to the present invention, in the low engine speed range where the engine speed is equal to or lower than a predetermined value, the engine speed is set to the target engine speed during normal operation when downshifting due to the decrease in vehicle speed is not performed. While the feedback control that changes the engine torque to bring it closer to the engine speed prevents the engine speed from dropping excessively, while performing a downshift due to a decrease in vehicle speed in the low speed range, the engine speed is synchronized with this. By limiting the engine torque increasing operation for control, there is an effect that the shift shock accompanying the downshift can be significantly reduced.

Particularly, in the device according to the second aspect, the feedback control of the engine speed is prohibited at the time of downshifting due to the decrease of the vehicle speed, so that the shift shock due to the increase of the engine torque at the downshifting can be further reduced. is there.

According to the third aspect of the present invention, the feedback control of the engine speed is performed only when the engine speed is less than or equal to a predetermined value and the throttle valve is fully closed, that is, when the driver does not intend to accelerate. Therefore, it is possible to prevent the control to bring the engine speed closer to the target speed against the driver's will.

Further, in the device according to the fourth aspect, only when the actual vehicle speed is less than the vehicle speed substantially equal to the minimum value of the vehicle speed at which the engine torque is not transmitted to the wheel side when the throttle valve is fully closed, that is, Only when the increase in the engine torque has a large effect on the shift shock, the engine torque increasing operation for controlling the engine speed is limited. Therefore, the vehicle speed is relatively high, and the shift shock due to the increase in the engine torque is prevented. When there is almost no effect of, that is, when the need for torque limitation is low,
As usual, the engine speed can be accurately approached to the target speed by feedback control.

According to the fifth aspect of the present invention, the correction of the adjustment amount is based on the current detected speed ratio during feedback control, and when the feedback control is limited, the predicted speed ratio after downshifting (that is, rather than the current detected speed ratio). Since it is based on (low speed ratio), the engine torque adjustment amount can be set lower when feedback control is limited,
Moreover, this correction has an effect that the engine speed after the feedback restriction is released can be brought closer to the target speed more quickly.

According to the seventh and ninth aspects of the present invention, by holding the actual intake air amount and the ignition timing at the intake air amount corresponding to the target rotation speed when the limit command is input, the target rotation speed can be obtained while the feedback is prohibited. There is an effect that the engine torque can be set in consideration of the above.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a powertrain control device according to a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a power train in the above embodiment.

FIG. 3 is a flowchart showing an engine speed control operation performed by the control device.

FIG. 4 is a flowchart showing an engine speed control operation performed by the control device.

FIG. 5A is a graph showing a relationship between a target rotational speed introduced in the engine rotational speed control and a basic intake air amount, and FIG. 5B is a graph showing a speed and a speed ratio correction coefficient introduced in the control. It is a graph which shows a relationship.

FIG. 6 (a) is a time chart showing the behavior of the target rotation speed, turbine rotation speed, and intake air amount under the control of the conventional apparatus, and FIG. 6 (b) is the target rotation speed under the control of the above-described apparatus of the embodiment. 3 is a time chart showing the behavior of the turbine speed and the intake air amount.

FIG. 7 is a block diagram showing the overall configuration of a powertrain control device according to a second embodiment of the present invention.

[Explanation of symbols]

AT Automatic transmission E Engine 2 Torque converter 10 Transmission mechanism 30 Hydraulic control device 54 Throttle valve 56 Spark plug 57 Distributor 58 ISC passage 59 ISC valve 61 Vehicle speed sensor 62 Throttle sensor 63 Engine speed sensor (speed ratio detection means) 64 Turbine rotation Number sensor (speed ratio detecting means) 70 Control unit 71 Shift control means 72 Feedback prohibiting means 73 Speed ratio calculating means (speed ratio detecting means and speed ratio predicting means) 74 Intake air amount adjusting means 75 Ignition timing adjusting means

Continuation of the front page (56) Reference JP 63-65145 (JP, A) JP 63-111245 (JP, A) JP 1-159437 (JP, A) JP 3-88928 (JP , A) JP-A-6-1163 (JP, A) JP-A-58-91332 (JP, A) JP-A-58-172445 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) F02D 29/00 F02D 41/00-45/00 F02P 5/15

Claims (9)

(57) [Claims] 1. An engine speed detecting means for detecting an engine speed and a feedback control for bringing the engine speed close to a preset target speed when the detected engine speed drops to a predetermined value or less. In a power train control device including engine torque adjusting means for changing the engine torque to perform the engine torque adjustment means, when the automatic transmission provided in the power train performs a downshift accompanying a vehicle speed decrease, A control device for a power train, comprising engine torque limiting means for inputting a limit command for torque increasing operation. 2. The power train control device according to claim 1, wherein the engine torque limiting means issues an instruction to prohibit the engine speed feedback control to the engine torque adjusting means when a downshift is performed due to a decrease in vehicle speed. A control device for a power train, which is a feedback inhibiting means for inputting. 3. The power train control device according to claim 1, wherein the engine torque adjusting means is configured to perform feedback control of the engine speed only when the throttle valve is fully closed. Power train control device. 4. The powertrain control device according to claim 3, further comprising a vehicle speed detecting means, wherein the detected vehicle speed is substantially the minimum value of the vehicle speed at which the engine torque does not contribute to driving the wheels when the throttle valve is fully closed. A control device for a power train, characterized in that the engine torque limiting means is configured to input the engine torque increasing operation limiting command to the engine torque adjusting means only when the vehicle speed is less than an equal value. 5. The powertrain control device according to claim 1, wherein speed ratio detecting means for detecting a speed ratio in the automatic transmission and speed ratio for predicting a speed ratio after downshifting. With the predicting means, the engine torque adjusting means is configured to correct the adjustment amount of the engine torque higher as the speed ratio is lower based on the speed ratio, and at the time of the feedback control, based on the detected speed ratio, The power train control device is characterized in that the engine torque adjusting means is configured to correct the engine torque adjustment amount based on the predicted speed ratio when feedback control is limited. 6. The powertrain control device according to claim 1, wherein the engine torque adjusting means is an intake air amount adjusting means for adjusting an intake air amount of the engine. Powertrain controller. 7. The power train control device according to claim 6, wherein the intake air amount adjusting means is configured to maintain an actual intake air amount at an intake air amount corresponding to the target rotation speed when the limit command is input. A power train control device characterized by the above. 8. The powertrain control device according to claim 1, wherein the engine torque adjusting means is an ignition timing adjusting means for adjusting an ignition timing of the engine. Control device. 9. The power train control device according to claim 8, wherein the ignition timing adjusting means is configured to maintain an actual ignition timing at an ignition timing commensurate with the target rotational speed when the limit command is input. Characteristic power train control device.