JPH05180027A - Control device for engine - Google Patents

Abstract

PURPOSE:To enhance the responsiveness of torque-down control in an engine in which the output torque is lowered upon a slip at drive wheels, by controlling a supercharged pressure regulating means so as to lower the supercharged pressure of a supercharger during torque-down control. CONSTITUTION:In an engine in which a first throttle valve 12 opened and closed by an actuator 11, and a second throttle valve 13 opened and closed in association with the operation of an accelerator pedal, are disposed in series in an intake passage 2, and which incorporates superchargers 4, 7 so as to super- charge intake-air, torque-down control is carried out in such a way that when a slip occurs at drive wheels, the first throttle valve 12 is controlled in the closing direction so as to lower the output torque. In this case, a supercharged pressure regulating means 28 such as a waste gate vale for regulating the supercharged pressure of intake-air is incorporated. During such an operation that the output torque of the engine 1 is lowered by the torque-down control, a super-charged pressure control means 1 controls the supercharged pressure regulating means 28 so as to lower the supercharged pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device, and more particularly to an engine control device which detects a slip of a driving wheel of a vehicle to reduce an output torque of the engine.

[0002]

2. Description of the Related Art Conventionally, a slip of driving wheels is detected during acceleration of a vehicle, and when a slip occurs, the output torque of an engine is reduced to suppress the slip so as to secure a traction force of the vehicle. The so-called traction control is known.

As a control device for controlling the output of this engine, as disclosed in Japanese Patent Laid-Open No. 62-67257, when an engine torque down condition is satisfied due to a slip of a driving wheel, the intake passage of the engine is provided. An electric control throttle valve that is arranged in series with a normal throttle valve and is driven to open and close by an actuator is closed, and at the same time, the ignition timing of the engine is corrected to the retard side,
It is known that the synergistic effect of the two increases the torque reduction rate of the output torque of the engine.

[0004]

By the way, for example, in an engine with a supercharger equipped with a turbocharger for driving a compressor by the exhaust energy of the engine to supercharge the intake air, during the supercharging of the intake air by the supercharger. However, even if an attempt is made to reduce the output torque of the engine due to the occurrence of a slip of the drive wheel, the supercharger is in the operating state, so even if the electrically controlled throttle valve in the intake passage is closed, the supercharging pressure does not immediately decrease. However, there is a problem that the response of the torque down control is poor.

The present invention has been made in view of the above problems, and an object thereof is, in the engine with a supercharger as described above, when there is a request for reducing the torque of the engine,
By controlling the supercharger in addition to controlling the electrically controlled throttle valve, the torque of the engine with the supercharger can be quickly reduced, and the response of the torque down control is improved.

[0006]

In order to achieve this object, according to the invention of claim 1, when an engine torque down condition is satisfied, an electric control throttle valve driven by an actuator is closed, and at the same time, a supercharger. It was made to reduce the intake supercharging pressure.

That is, according to the present invention, as shown in FIG. 1, a first throttle valve 12 is provided in the intake passage 2 and is opened and closed by being driven by an actuator 11, and the first throttle valve is provided in the intake passage 2. Arranged in series with 12,
The first throttle valve 12 is provided with a second throttle valve 13 that opens and closes in conjunction with an accelerator pedal, and superchargers 4 and 7 that supercharge intake air, when a drive wheel of the vehicle slips. It is premised on the engine 1 in which the torque down control is performed by controlling the engine in the closing direction to reduce the output torque.

With respect to the engine 1 with the supercharger, the supercharging pressure adjusting means 28 for adjusting the supercharging pressure of intake air supercharged by the superchargers 4 and 7, and the output of the engine 1 by the torque down control. A supercharging pressure control means 71 is provided for controlling the supercharging pressure adjusting means 28 so that the supercharging pressure of intake air is reduced when the torque is reduced.

According to the second aspect of the present invention, the supercharging pressure control means 71 is controlled by the supercharging pressure adjusting means 2 during execution of the torque down control.
8 is configured to be released.

In the invention of claim 3, the superchargers 4, 7 are turbochargers, and the supercharging pressure adjusting means 28 is a wastegate valve for controlling exhaust energy to the turbochargers 4, 7. The supercharging pressure control means 71 is configured to release the control on the waste gate valve 28 in synchronization with the stop timing of the torque down control predicted by the change in the slip amount of the drive wheels of the vehicle. ..

[0011]

With the above construction, according to the first aspect of the invention, when the torque down request condition of the engine 1 is satisfied due to the occurrence of the slip of the drive wheels of the vehicle, the first throttle of the intake passage 2 is executed by executing the torque down control. The valve 12 is closed and the amount of intake air to the engine 1 is reduced, and its output torque is reduced. Simultaneously with the execution of this torque down control, the supercharging pressure control means 71 is operated to control the supercharging pressure adjusting means 28 so that the supercharging pressure of the intake air by the superchargers 4 and 7 is reduced. The output torque of the engine 1 decreases due to the decrease in pressure. Therefore, in this way, the first throttle valve 1
By decreasing the intake supercharging pressure in synchronization with the closing operation of 2,
The responsiveness of the torque down control of the engine 1 can be improved.

In the invention of claim 2, the boost pressure control means 71.
As a result, the control for the supercharging pressure adjusting means 28 is released during the execution of the torque down control, so that the output torque of the engine 1 is maintained even if the first throttle valve 12 is closed, that is, the supercharging pressure increases. Will return to the normal supercharging pressure control state when it is difficult to increase rapidly, and when the output torque of the engine 1 suddenly increases when the torque down control is released, the feeling of runaway of the vehicle and the recurrence of the slip of the drive wheels are effective. Can be prevented.

In the invention of claim 3, the boost pressure control means 71
As a result, the control of the wastegate valve 28 is released in synchronization with the stop timing of the torque down control predicted by the change in the slip amount of the drive wheels of the vehicle. Since the supercharging pressure due to is increased, it is possible to prevent the supercharging pressure from increasing in the closed state of the first throttle valve 12 and the throttle valve 12 from entering the surging state due to the supercharging pressure. 1
The reliability of 2 can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG.

(Embodiment 1) FIG. 2 shows the overall construction of Embodiment 1 of the present invention, in which 1 is a rotary engine mounted on a front-wheel drive vehicle, 2 is an intake passage for supplying intake air to the engine 1. , The upstream end of the intake passage 2 is connected to an air cleaner (not shown), and the intake passage 2 on the downstream side of the air cleaner is connected.
An air flow meter 3 for detecting the amount of intake air is arranged in the. The intake passage 2 is divided into two first and second branch passages 2a and 2b on the downstream side of the air flow meter 3 and then assembled together, and a primary turbocharger that supercharges intake air in the middle of the first branch passage 2a. A compressor 5 of No. 4 and a compressor 8 of the same secondary turbocharger 7 are arranged in the middle of the second branch passage 2b.
In the intake passage 2 on the downstream side of both the branch passages 2a and 2b, an intercooler 10 for cooling the intake air pressurized by the compressors 5 and 8 of the superchargers 4 and 7, a servomotor, a stepping motor, etc. An electric control throttle valve 12 as a first throttle valve that is driven by an actuator 11 to open and close the intake passage 2, and a machine as a second throttle valve that opens and closes the intake passage 2 in conjunction with an accelerator pedal (not shown). Control throttle valve 13 and surge tank 1
4 are arranged in the order described.

Further, the intake passage 2 on the downstream side of the surge tank 14 is branched into two independent intake passages 2c, 2c, and each independent intake passage 2c is connected to each cylinder via an intake port of the engine 1. An injector 15 for injecting and supplying fuel is arranged in each independent intake passage 2c.

Reference numerals 16 and 17 denote exhaust passages for exhausting exhaust gas in the cylinders of the engine 1.
17 is provided independently for each cylinder of the engine 1, and one of the exhaust passages 16 and 17 is provided with the primary turbocharger 4 described above.
Of the secondary turbocharger 7 is arranged on the other side, and the turbine 6 of the secondary turbocharger 7 is arranged on the other side.
Reference numeral 9 is connected to the compressors 5 and 8 so as to rotate together. Both exhaust passages 16 and 17 are assembled together on the downstream side of the turbines 6 and 9 and are connected to a silencer (not shown).

The exhaust passages 16 and 17 on the upstream side of the turbochargers 4 and 7 are communicated with each other through a communication passage 18 having a relatively small cross-sectional area, and the exhaust passage 17 on the secondary turbocharger 7 side is connected to the exhaust passage 17. A normally closed exhaust cut valve 19 that opens and closes the exhaust passage 17 by being driven by a diaphragm-type actuator 20 is provided immediately downstream of the opening position of the passage 18. The pressure chamber of the actuator 20 is connected to the output port of the electromagnetic solenoid type three-way valve 22 via the passage 21. One input port of the three-way valve 22 is connected via a passage 25 to a negative pressure tank 24 into which intake negative pressure downstream of the throttle valves 12 and 13 is introduced via a check valve 23, and the other input port. Is open to the atmosphere.
When the three-way valve 22 is off, the actuator 2
When the passage 21 communicating with the 0 pressure chamber is communicated with the negative pressure tank 24 side, negative pressure is supplied to the actuator 20 to close the exhaust cut valve 19, while the three-way valve 22 is in the ON state, and the passage 21 is exposed to the atmosphere. Exhaust cut valve 19 when opened to
Is opened to perform supercharging by the secondary turbocharger 7.

A bypass passage 26 connects the midway of the communication passage 18 and the exhaust passages 16 and 17 that are gathered on the downstream side of both turbines 6 and 9, and is driven by a diaphragm type actuator 29 in the bypass passage 26. A wastegate valve 28 is provided as a boost pressure adjusting means for opening and closing the bypass passage 26. The pressure chamber of the actuator 29 is connected to the output port of the electromagnetic solenoid type three-way valve 31 via the passage 30. One input port of the three-way valve 31 is connected to a first branch passage 2a downstream of the compressor 5 of the primary turbocharger 4 via a passage 35 described later, and the other input port is open to the atmosphere. There is. Then, when the three-way valve 31 is in the ON state, supercharging pressure is introduced into the pressure chamber of the actuator 29 to open the waste gate valve 28, and a part of the exhaust gas is caused to flow down by bypassing the turbines 6 and 9. , Turbine 6,
9 and the compressors 5 and 8 driven by the turbines 6 and 9 are reduced in rotation speed to reduce intake supercharging pressure. When the three-way valve 31 is in the OFF state, the pressure chamber of the actuator 29 is opened to the atmosphere and the wastegate valve 28 is opened.
Is closed to increase the intake supercharging pressure.

Further, the bypass passage 26 upstream of the wastegate valve 28 and the exhaust passage 17 upstream of the turbine 9 of the secondary turbocharger 7 and downstream of the exhaust cutoff valve 19 have an exhaust leakage passage 32. The exhaust leakage passage 32 is provided with a normally closed exhaust leakage valve 33 which is driven by a diaphragm type actuator 34 to open and close the exhaust leakage passage 32. The pressure chamber of the actuator 34 has a passage 3 in the first branch passage 2a downstream of the compressor 5 of the primary turbocharger 4.
When the pressure on the downstream side of the compressor 5 becomes equal to or higher than a predetermined value, the exhaust leak valve 33 is opened by the operation of the actuator 34, and a small amount of the exhaust cut valve 19 is closed. Exhaust gas is supplied to the turbine 9 of the secondary turbocharger 7 through the bypass passage 26, the secondary turbocharger 7 is pre-rotated before the exhaust cut valve 19 is opened, and the exhaust cut valve 19 is opened. It is designed to improve the transient response at the time.

On the other hand, in the second branch passage 2b on the downstream side of the compressor 8 of the secondary turbocharger 7, an intake cut valve 36 which is driven by a diaphragm type actuator 37 to open and close the second branch passage 2b is arranged. The pressure chamber of the actuator 37 is connected to the output port of the electromagnetic solenoid type three-way valve 39 via the passage 38. One input port of the three-way valve 39 is connected to the negative pressure tank 24 via a passage 40, and the other input port is connected to the differential pressure detection valve 42.
Are connected to the respective output ports via the passage 41. Although not shown, the differential pressure detection valve 42 also has first and second input ports and an atmosphere opening port, and the first input port is a passage 43 in the intake passage 2 downstream of the intake cut valve 36.
And the second input port is connected to the second branch passage 2b on the upstream side of the intake cut valve 36 via the passage 44, respectively. The output port of the differential pressure detection valve 42 is opened when the pressure difference introduced from both input ports exceeds a predetermined value. That is, when the three-way valve 39 connected to the output port is in the ON state, the passage 38 that communicates with the pressure chamber of the actuator 37 for driving the intake cut valve 36.
And the passage 41 communicating with the output port of the differential pressure detection valve 42 are in communication with each other, the pressure on the upstream side of the intake cut valve 36, that is, the supercharging pressure by the secondary turbocharger 7 is the primary turbocharger 4. When the pressure difference between the two supercharging pressures disappears due to approaching the supercharging pressure due to, the two pressures are further reversed and the pressure difference becomes larger than a predetermined value.
Atmospheric air is introduced into the intake valve 24 to open the intake cut valve 36, while the three-way valve 39 is turned off, and the passage 38 is connected to the negative pressure tank 24.
When they are communicated with each other, a negative pressure is introduced into the actuator 37 to close the intake cut valve 36.

A relief passage 45, which bypasses the compressor 8 of the secondary turbocharger 7, is branched and connected to the second branch passage 2b, and the relief passage 45 is driven by a diaphragm type actuator 47 to drive the relief passage. Normally closed intake relief valve 46 that opens and closes 45
Are arranged. The pressure chamber of the actuator 47 is connected to the output port of an electromagnetic solenoid type three-way valve 49 via a passage 48. One input port of the three-way valve 49 is connected to the negative pressure tank 24 via a passage 50, and the other input port is open to the atmosphere. When the three-way valve 49 is OFF, the actuator 4
When the passage 48 that communicates with the pressure chamber of No. 7 communicates with the negative pressure tank 24 side, negative pressure is supplied to the actuator 47 to open the intake relief valve 46, while the three-way valve 49 is turned on.
In this state, when the pressure chamber of the actuator 47 is opened to the atmosphere, the intake relief valve 46 is closed. As a result, by opening the relief passage 45 by the intake relief valve 46 until a predetermined time before the exhaust cut valve 19 and the intake cut valve 36 are opened, the secondary turbocharger 7 is driven by the exhaust gas flowing through the exhaust leakage passage 32. When pre-rotating,
The pressure upstream of the intake cut valve 36 is increased to prevent it from entering the surging region, and the rotation of the compressor 8 of the secondary turbocharger 7 is increased.

The above four three-way valves 22, 31, 39, 4
9. The actuator 11 for driving the electrically controlled throttle valve 12 and the injector 15 are the control unit 61.
It is controlled by. The control unit 61 includes an output signal of the air flow meter 3, an output signal of a rotation speed sensor 63 for detecting an engine rotation speed based on a rotation angle of an output shaft of the engine 1, and a downstream side of the mechanical control throttle valve 13. Output signal of the pressure sensor 64 that detects the intake negative pressure (boost) of the electric rottle valve 1
The output signal of the electric control throttle sensor 65 which detects the opening degree of 2 and the output signal of the mechanical control throttle sensor 66 which detects the opening degree of the mechanical control throttle valve 13 and the front wheels and the rear wheels which are the driven wheels of the vehicle. Various signals including at least the output signal of the wheel speed sensor 67 (only one is shown) that detects the number of revolutions (none of which is shown) (for example, a water temperature sensor that detects the cooling water temperature of the engine 1 and the like) Signal) is being input.

The control unit 61 has a built-in traction control unit 62, and the traction control unit 62 causes the drive wheels (front wheels) of the vehicle to slip, thereby requesting a predetermined torque reduction of the engine 1. When the condition is satisfied, the electric control throttle valve 12 is controlled in the closing direction to reduce the supply of intake air to the engine 1, thereby performing the torque down control for reducing the output torque of the engine 1. There is. The presence or absence of slippage of the drive wheels is detected by comparing the difference between the front and rear wheel rotation speeds detected by the wheel speed sensor 67 with a predetermined value.

The control procedure for the three-way valve 31 for controlling the wastegate valve 28 in the control unit 61 will be described with reference to FIG. First, in the first step S1 after the start, the traction control unit 6
At 2, it is determined whether or not traction control is being performed in order to reduce the output torque of the engine 1 due to the slip of the drive wheels. If this determination is NO, the process ends, but Y
In case of ES, the process proceeds to step S2, and the three-way valve 31 O
The wastegate valve 28 is fully opened by N operation. Next, in step S3, the electric control throttle sensor 65 is
It is determined whether or not the opening degree of the electric control throttle valve 12 detected by the above is a target opening degree set according to the slip amount of the driving wheel. If the determination is NO, the process returns to step S2. On the other hand, if the determination is YES, step S
In step 4, it is determined whether the intake negative pressure detected by the pressure sensor 64 is less than or equal to a predetermined target value, and if this determination is NO, the process returns to step S2. Judgment is YES
If so, the routine proceeds to step S5, and the supercharging pressure control by the waste gate valve 28 is returned to the normal control.

In this embodiment, step S in the above flow.
With 1 to S5, with the execution of the torque down control,
When the output torque of the engine 1 is reduced by reducing the opening degree of the electric control throttle valve 12, at the same time, the opening degree of the waste gate valve 28 is controlled to be fully open so that the supercharging pressure of intake air is reduced. The supercharging pressure control means 71 is configured to release the control of the wastegate valve 28 during the torque down control.

Therefore, in the above embodiment, the traction control is performed when the front wheel, which is the driving wheel, slips and the output torque down request condition of the engine 1 is satisfied with the opening degree of the mechanical control throttle valve 13 being large during acceleration of the vehicle. Therefore, the torque reduction control of the engine 1 is performed.
That is, when the torque down control signal is output from the traction control unit 62 as shown in FIG.
As shown in (a), the opening degree of the electric control throttle valve 12 is once fully closed from the fully opened state and then positioned at a target opening degree with a small opening degree. This reduces the output torque of the engine 1. Simultaneously with the adjustment of the opening degree of the electrically controlled throttle valve 12, the three-way valve 31 is switched to the ON state to introduce the boost pressure into the pressure chamber of the actuator 29.
By operating the actuator 29, the waste gate valve 2
8 is switched from the fully closed state to the fully open state as shown in FIG. 4 (c), and the supercharging pressure generated by the turbochargers 4 and 7 is reduced. As a result, the intake charge amount to the engine 1 is significantly reduced, the output torque of the engine 1 is reduced, and the slip of the front wheels is suppressed.

In this case, the wastegate valve 28 is opened in synchronization with the closing operation of the electrically controlled throttle valve 12, and the intake supercharging pressure is reduced. Therefore, even in the engine 1 with a supercharger, the torque reduction control is performed. The responsiveness can be enhanced.

During execution of this torque down control,
When the opening degree of the electrically controlled throttle valve 12 is at the target opening degree and the intake negative pressure detected by the pressure sensor 64 becomes equal to or less than the target value as shown in FIG. 4D, the three-way valve 31 is turned off. By switching, the pressure chamber of the actuator 29 is opened to the atmosphere, and by stopping the operation of the actuator 29, the wastegate valve 28 is switched from the fully open state to the original fully closed state as shown in FIG. The supercharging pressure control of the machines 4 and 7 is performed as usual. In this way, the engine 1 is controlled even when the control for the waste gate valve 28 is executing the torque down control, that is, the electric control throttle valve 12 is close to the target opening degree and the boost pressure increases.
Is canceled when it is difficult to increase the output torque rapidly. Therefore, when the torque down control is canceled, the output torque of the engine 1 suddenly increases due to the increase of the supercharging pressure. It can be effectively prevented and good accelerator feeling can be maintained during re-acceleration.

(Embodiment 2) FIG. 5 shows Embodiment 2 of the present invention in which the return of the supercharging pressure to the normal control is synchronized with the stop of the torque down control. The basic configuration of this embodiment is the same as that of the first embodiment (see FIG. 2), and only the signal processing procedure in the control unit 61 is different. That is, as shown in FIG. 5, in the first step S11, it is determined whether or not the traction control is being performed. If the determination is NO, the process ends, but if YES, the process proceeds to step S12, and the three-way valve 31 is turned on to cause the wastegate to be turned on. Valve 28
Fully open. Next, in step S13, the release timing of the torque down control is predicted by obtaining the change in the slip amount from the difference between the wheel speeds detected by the front and rear wheel speed sensors 67, and in the next step S14, the torque down control is released. It is determined whether or not When this determination is NO, the same step S14 is repeated, but when the torque down control is canceled and the determination becomes YES, the routine proceeds to step S15, and the supercharging pressure control by the waste gate valve 28 is returned to normal control.

In this embodiment, steps S11 to S15 are performed.
The supercharging pressure control means 71 'is constituted by the supercharging pressure control means 71', and the supercharging pressure control means 71 'is synchronized with the stop timing of the torque down control predicted by the change in the slip amount of the drive wheels of the vehicle. Is configured to release control over.

Therefore, in the case of this embodiment, unlike the first embodiment, the release of the control for the wastegate valve 28 is synchronized with the stop timing of the torque down control predicted by the change in the slip amount of the drive wheels of the vehicle. Since the supercharging pressure by the turbochargers 4 and 7 increases at the same time as the end of the torque down control, the supercharging pressure rises with the electric control throttle valve 12 closed, and the turbocharging pressure increases the throttle pressure. There is an advantage that the valve 12 can be prevented from entering a surging state and the reliability of the electrically controlled throttle valve 12 can be improved.

In the above embodiment, the case where the electric control throttle valve 12 is arranged upstream of the mechanical control throttle valve 13 in the intake passage 2 has been described, but also in the case where it is arranged downstream. It can be applied and the same effect can be obtained.

The present invention can also be applied to an engine with superchargers 4 and 7 equipped with one turbocharger or a supercharger driven by an engine.

Although the above embodiment is for the rotary engine 1, the present invention can also be applied to a reciprocating engine.

[0036]

As described above, according to the invention of claim 1, when the drive wheels of the vehicle slip,
For an engine with a supercharger in which a throttle valve driven by an actuator is closed to reduce the output torque of the engine, supercharging pressure adjusting means for adjusting the supercharging pressure of the supercharger is provided, and the torque down control is performed. At the same time, the supercharging pressure adjusting means is controlled to lower the supercharging pressure, so that the intake supercharging pressure can be quickly reduced in synchronization with the closing operation of the throttle valve, and the torque of the engine with the supercharger can be reduced. It is possible to improve the responsiveness of the down control.

According to the second aspect of the present invention, the control for the supercharging pressure adjusting means is released during the torque down control, so that the output torque of the engine rapidly increases with the throttle valve closed. When it is difficult, it is possible to return to the normal supercharging pressure control state, and it is possible to effectively prevent a reckless feeling of the vehicle and a recurrence of the slip of the drive wheels due to a sudden increase in the output torque of the engine when the torque down control is released.

According to the third aspect of the present invention, the turbocharger is used as a turbocharger, and the supercharge pressure is adjusted by a wastegate valve that controls exhaust energy for the turbocharger. In synchronization with the stop time of the torque down control predicted by the change in the slip amount of the driving wheels,
Since the control for the waste gate valve is released, surging of the throttle valve when the boost pressure increases with the throttle valve closed can be prevented, and the reliability of the throttle valve can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of the present invention.

FIG. 2 is a system diagram showing a configuration of a first embodiment of the present invention.

FIG. 3 is a flowchart showing an algorithm of supercharging pressure control processed by a control unit in the first embodiment.

FIG. 4 is a characteristic diagram showing changes in various states during engine torque down control in the first embodiment.

FIG. 5 is a view corresponding to FIG. 3 showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 engine 2 intake passage 4, 7 supercharger 11 actuator 12 electric control throttle valve (first throttle valve) 13 mechanical control throttle valve (second throttle valve) 28 wastegate valve (supercharging pressure adjusting means) 29 actuator 61 control unit 62 traction control unit 71, 71 'supercharging pressure control means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display area F02D 41/22 310 E 9039-3G 43/00 301 K 7536-3G R 7536-3G Y 7536-3G 45/00 345 G 7536-3G

Claims (3)

[Claims] 1. A first throttle valve which is arranged in an intake passage and is opened and closed by being driven by an actuator, and a first throttle valve which is arranged in series in the intake passage and is opened and closed in conjunction with an accelerator pedal. A second throttle valve and a supercharger for supercharging intake air are provided, and when the drive wheels of the vehicle slip, the first throttle valve is controlled in the closing direction to reduce the engine output torque. In an engine configured to perform a torque down control, a supercharging pressure adjusting means for adjusting a supercharging pressure of intake air supercharged by the supercharger, and an intake air when reducing an output torque of the engine by the torque down control. And a supercharging pressure control means for controlling the supercharging pressure adjusting means so as to reduce the supercharging pressure of the engine. 2. The engine control device according to claim 1, wherein the supercharging pressure control means is configured to release the control for the supercharging pressure adjusting means during execution of the torque down control. Control device for the engine. 3. The engine control device according to claim 1, wherein the supercharger is a turbocharger, and the supercharging pressure adjusting means is a wastegate valve that controls exhaust energy for the turbocharger. The supply pressure control means is configured to release the control on the waste gate valve in synchronization with the stop timing of the torque down control predicted by the change in the slip amount of the drive wheels of the vehicle. Engine control unit.