JPH112147A - Intake air flow adjusting device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To normally open and close a throttle valve in a machine where an air throttle valve is rotated by a reluctance motor, by locating the air throttle valve on a rotary position where the reluctance motor can generate the maximum torque at an opening side of the air throttle valve when the air throttle valve has the almost minimum opening. SOLUTION: A throttle valve 2 mounted on the way of an intake duct 3, comprises a return spring 4 for energizing the throttle valve 2 in a valve closing direction through a shaft 7, and the throttle valve 2 is driven to be opened and closed through the gears 9, 8 by a reluctance motor 1. On this occasion, they are assembled in such manner that an angle of rotation of a rotor of the reluctance motor 1 is set within a range from (90×N-15) to (90×N) degree, when the throttle valve 2 is located on the totally-closed position (minimum opening) where the throttle valve 2 has the possibility of fixing by deposite or the like. Further the torque at the start of power supply, is determined, so that an energization phase which can be optionally generated at an opening side of the throttle valve 2, is provided with the specific (a) phase and (b) phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an intake air amount adjusting device for an engine in which an air throttle valve is driven by an electric motor.

[0002]

2. Description of the Related Art In an automobile engine or the like, an intake air amount adjusting device that opens and closes a throttle valve via an electric motor according to operating conditions independently of the operation of an accelerator pedal. There is.

Conventionally, as this type of intake air amount adjusting device, for example, one disclosed in Japanese Patent Application Laid-Open No. Hei 2-25639, a throttle valve is driven by a DC motor with a brush.

However, deposits (combustion products) and the like adhere to the throttle valve and the surrounding intake passage wall,
If the throttle valve sticks to the intake passage wall near its fully closed position, the operability of opening and closing the throttle valve may be deteriorated.

To cope with this, for example, Japanese Patent Laid-Open No. 5-126 is disclosed.
No. 016 discloses an electric motor for opening and closing a throttle valve, and a diaphragm type actuator for opening a throttle valve fixed by a deposit or the like by a negative suction pressure of an engine.

However, by providing the electric motor and the diaphragm type actuator together, the structure becomes complicated and the cost is increased.

To cope with this, it is conceivable to use a reluctance motor capable of obtaining a torque required to open a throttle valve fixed by deposit or the like.

However, since the maximum torque that can be generated in the reluctance motor varies according to its rotational position, the torque required to open the throttle valve fixed by deposit or the like is obtained depending on the position where the reluctance motor is assembled. There is a problem that there is not (see JP-A-2-206391).

The present invention has been made in view of the above-described problems. Even when a throttle valve is fixed to an intake passage wall by a deposit or the like, an intake air amount of an engine which can be normally opened and closed via a reluctance motor. It is an object to provide an adjusting device.

[0010]

According to a first aspect of the present invention, there is provided an engine intake air amount adjusting apparatus comprising: a return spring for urging an air throttle valve in a valve closing direction; and a reluctance motor for rotatingly driving the air throttle valve. In the intake air amount adjusting device for an engine provided, the reluctance motor is at a rotational position where the maximum torque can be generated on the opening side of the air throttle valve when the air throttle valve is near the minimum opening.

According to a second aspect of the present invention, there is provided an engine intake air amount adjusting apparatus according to the first aspect, further comprising a three-phase reluctance motor that rotationally drives the air throttle valve, and sets the air throttle valve to a minimum opening degree. The torque of the reluctance motor can be generated on the open side of the air throttle valve when the reluctance motor is in the open state, and the torque can be generated on the open side of the air throttle valve at the start of energization of the reluctance motor. A start-up control means for supplying a maximum current to predetermined two phases is provided.

According to a third aspect of the present invention, in the engine intake air amount adjusting apparatus according to the second aspect of the present invention, the start-up control means continuously applies the torque to the air for a predetermined time1 when the reluctance motor is energized. The maximum current is supplied to two predetermined phases that can be generated on the opening side of the throttle valve.

According to a fourth aspect of the present invention, in the engine intake air amount adjusting device according to the second aspect of the present invention, there is provided a means for detecting an opening degree of an air throttle valve, and the starting control means comprises:
Torque can be continuously generated on the open side of the air throttle valve until the opening of the air throttle valve exceeds a predetermined value at the start of energization of the reluctance motor or until the difference from the opening before the start of energization exceeds the predetermined value. The maximum current was supplied to two predetermined phases.

According to a fifth aspect of the present invention, there is provided an apparatus for adjusting an intake air amount of an engine, the intake passage for guiding air to be taken into the engine, and the amount of air taken into the engine being rotatably interposed in the intake passage. Means for detecting the rotor position of the reluctance motor, wherein the means for detecting the rotor position of the reluctance motor corresponds to the rotor position at the start of energization of the reluctance motor. In this case, there is provided a start-up control means for supplying a maximum current to two phases having the same sign of the differential value of the inductance with respect to the rotation direction.

According to a sixth aspect of the present invention, in the engine according to the fifth aspect of the present invention, the start-up control means may be configured such that the sign of the differential value of the inductance with respect to the rotation direction at the start of energization of the reluctance motor. The maximum current is continuously supplied to the same two phases for a predetermined time time1.

According to a seventh aspect of the present invention, in the engine intake air amount adjusting device according to the fifth aspect of the present invention, there is provided means for detecting an opening degree of an air throttle valve, and the starting control means comprises:
At the start of energization of the reluctance motor, until the opening of the air throttle valve exceeds a predetermined value, or the difference from the opening before energization exceeds a predetermined value, in two phases in which the sign of the differential value of the inductance with respect to the rotation direction is the same. Until the maximum current is supplied.

According to an eighth aspect of the present invention, in the engine intake air amount adjusting device according to the fourth or seventh aspect, the opening degree of the air throttle valve does not exceed a predetermined value or the opening degree before the start of energization. The elapsed time from the start of energization of the reluctance motor without exceeding the predetermined value is a predetermined value time_e.
Means for determining an abnormal time exceeding rr is provided.

[0018]

According to the present invention, the reluctance motor opens the air throttle valve against the return spring, and the air throttle valve is independent of the operation of the accelerator pedal. Open and close.

When the engine is stopped, the air throttle valve is held at the minimum opening degree by the urging force of the return spring. Therefore, the air throttle valve may adhere to the intake passage wall via a deposit or the like. To cope with this, a reluctance motor that can obtain a torque necessary to open the air throttle valve fixed by deposit or the like is used.

However, since the generated torque of the reluctance motor fluctuates according to its rotational position, there is a possibility that the air throttle valve fixed by a deposit or the like cannot be opened at the time of startup depending on the assembly position of the reluctance motor. .

In view of this, the present invention restricts the mounting position of the reluctance motor with respect to the minimum opening of the air throttle valve, so that the air throttle valve is held at the minimum opening by the biasing force of the return spring. At startup, the reluctance motor can generate maximum torque. Thus, even when the air throttle valve is fixed to the intake passage wall due to a deposit or the like, the air throttle valve is encouraged to come out of the fixed state, and the opening and closing operation can be normally performed via the reluctance motor.

In the engine intake air amount adjusting device according to the second aspect, when the air throttle valve is at the minimum opening degree, 3
Assembling such that the exciting phase which can generate the torque of the phase reluctance motor on the opening side of the air throttle valve becomes two predetermined phases,
With the configuration in which current is supplied to two predetermined phases that can generate torque at the opening side of the air throttle valve at the start of energization of the reluctance motor, the reluctance motor can generate maximum torque at startup. Therefore, even when the air throttle valve is stuck to the intake passage wall due to deposit or the like, the air throttle valve is encouraged to come out of the stuck state, and can be normally opened and closed via the reluctance motor.

In the engine intake air amount adjusting device according to the third aspect, the reluctance motor generates a maximum torque for a predetermined period of time at the time of starting, thereby prompting the air throttle valve to come out of a fixed state, thereby promoting reluctance. Opening and closing operation can be normally performed via the motor.

According to a fourth aspect of the present invention, there is provided an apparatus for adjusting an intake air amount of an engine, wherein the reluctance motor is driven at a maximum torque until the opening of an air throttle valve exceeds a predetermined value or a difference between the opening and the opening before energization is started. By generating the air throttle valve until it exceeds the predetermined value, the air throttle valve is encouraged to come out of the fixed state, and can be normally opened and closed via the reluctance motor. At the same time, since it is possible to detect that the fixed state has been released, the operation for releasing from the fixed state can be completed promptly, and the mode can be promptly shifted to the mode for controlling the opening degree of the air throttle valve.

According to a fifth aspect of the present invention, at the start of energization of the reluctance motor, the maximum current is supplied to two phases having the same sign of the differential value of the inductance with respect to the rotation direction according to the rotor position. As a result, the maximum torque is generated according to the rotation angle θ of the rotor, and it is urged that the air throttle valve is released from the fixed state.

According to a sixth aspect of the present invention, in the apparatus for adjusting the amount of intake air for an engine, the reluctance motor generates a maximum torque for a predetermined period of time at the time of starting, so that the air throttle valve is fixed in accordance with the rotation angle θ of the rotor. , And can be normally opened and closed via the reluctance motor.

According to a seventh aspect of the present invention, when the reluctance motor is started, the maximum torque is adjusted according to the rotation angle θ of the rotor until the opening of the air throttle valve exceeds a predetermined value or the energization is started. When the difference from the previous opening degree exceeds a predetermined value, the air throttle valve is encouraged to come out of the fixed state, and the opening and closing operation can be normally performed via the reluctance motor. At the same time, since it is possible to detect that the fixed state has been released, the operation for releasing from the fixed state can be completed promptly, and the mode can be promptly shifted to the mode for controlling the opening degree of the air throttle valve.

In the engine intake air amount adjusting device according to the present invention, the reluctance is maintained while the opening of the air throttle valve does not exceed a predetermined value or the difference from the opening before the start of energization does not exceed a predetermined value. It is possible to notify the driver that the air throttle valve has become stuck by determining that the time elapsed after the start of energization of the motor exceeds the predetermined value time_err as an abnormal time.

[0029]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, an engine 14 mounted on an automobile draws intake air (air-fuel mixture) from an intake passage 3 into a cylinder as an intake valve 17 is opened, and the intake air is compressed by a piston 15. After ignition and combustion via the ignition plug 12, exhaust gas is discharged to the exhaust passage 13 as the exhaust valve 18 is opened, and each of these steps is continuously repeated. The reciprocating motion of the piston 15 is converted via a connecting rod 16 into a rotational motion of a crankshaft (not shown).

In the middle of the intake passage 3, there are provided a throttle valve 2 for restricting intake air and an injector 11 for injecting fuel.

As shown in FIG. 2, the butterfly type throttle valve 2 has a disc-shaped valve body connected to a shaft 7. The shaft 7 is rotatably supported via a bearing 5. A return spring 4 for urging the throttle valve 2 in a valve closing direction via a shaft 7 is provided.

The throttle valve 2 is opened and closed by the reluctance motor 1 via gears 9 and 8. Gear 9,
Reference numeral 10 decelerates the rotation of the reluctance motor 1 and transmits it to the shaft 7 of the throttle valve 2.

As shown in FIG. 3, a rotor 34 is connected to a shaft 7 of the three-phase reluctance motor 1, and four salient poles project from the rotor 34 at regular intervals in the circumferential direction. The pinching angle of each salient pole of the rotor 34 is 90 degrees.

A stator 36 is arranged around the rotor 34. The stator 36 has six salient poles projecting at a constant interval in the circumferential direction. The angle between each of the salient poles of the stator 36 is 60 degrees. Common windings 31, 32, and 33 are wound around salient poles of the stator 36 facing each other, so that a magnetic flux is generated in the same direction.

An encoder-type rotation angle sensor 37 is provided at one end of the rotation shaft 35 of the rotor 34. The encoder-type rotation angle sensor 37 detects the rotation position of the rotor 34 with respect to the stator 36.

The control circuit 19 of the reluctance motor 1
A signal from an accelerator opening sensor 20 for detecting an amount of depression of an accelerator pedal 22, a signal from a potentiometer type throttle opening sensor 6 for detecting an opening of the throttle valve 2,
The drive current of the reluctance motor 1 is controlled by inputting the signal of the encoder type rotation angle sensor 37 of the rotor 34 and the like. The control circuit 19 includes a CPU, a ROM, a RAM,
The microcomputer includes a microcomputer including an I / O, a timer, and the like, and a drive circuit for separately exciting the three phases 31, 32, and 33 of the reluctance motor 1.

As shown in FIG. 4, the drive circuit is driven by a battery 41 mounted on a vehicle from a winding 4 of each phase 31, 32, 33.
The current supplied to 5, 46, 47 is interrupted via each switching element 42, 43, 44. The PWM signal generating circuit 55 receives the signal of the encoder type rotation angle sensor 37 of the rotor 34 and
A PWM signal for turning on and off the switches 3 and 44 is output.
The supply current to each phase 31, 32, 33 is the PWM DUT
Adjustment is made by changing the Y ratio.

As shown in FIG. 5A, in the reluctance motor 1, when the three exciting phases are a phase, b phase, and c phase, the inductances La, Lb, and Lc of each phase are shifted by 30 degrees from each other. 34, and the excitation current to the a-phase, the b-phase, and the c-phase is varied by I
When a, Ib, and Ic are used, a torque determined by the following equation (1) is generated in the rotation direction.

Torque ≒ (1/2) × Ia ² × (dLa / dθ) + (1/2) × Ib ² × (dLb / dθ) + (1/2) × Ic ² × (dLc / dθ) (1) where θ is the rotation angle of the rotor 34, and La, Lb, and Lc are the self-inductance of each phase. Also, the effect of the mutual inductance of each phase is ignored as being sufficiently small.

Therefore, when the positive direction of the rotation angle of the rotor 34 is set to the direction in which the throttle valve 2 opens, the excitation phase capable of generating torque in the direction to open the throttle valve 2 is shown in FIG. As shown in FIG.
4 in order according to the rotation angle θ.

As shown in FIG. 5C, when the rotation angle of the rotor 34 is in a range up to (90 × N-30) degrees where N is an integer, the phase a for generating a positive torque is maximized. It is excited by current T ₁ only torque does not occur. On the other hand, when the rotation angle of the rotor 34 is in a range up to (90 × N) degrees, the a-phase and the b-phase generating the positive torque are excited by the maximum current to obtain about 2 × T ₁ . Torque is generated.

Therefore, according to the present invention, when the throttle valve 2 is in a fully closed position (minimum opening degree) where there is a possibility that the throttle valve 2 is fixed by deposit or the like, the rotation angle of the rotor 34 is (90 × N) in FIG. -15) The motor is assembled so as to be positioned in the range from (degrees) to (90 × N) degrees, so that the excitation phases that can generate torque on the opening side of the throttle valve 2 at the start of energization become predetermined a-phase and b-phase. Set to. Then, at the start of energization, the phases a and b are excited with the maximum current.

As a result, a torque of about 2 × T ₁ is generated, and even if the throttle valve 2 is fixed by deposit or the like, it can be easily removed.

FIG. 6 is a flow chart showing a routine for driving the reluctance motor 1.
9 is executed every 5 ms period.

To explain this, first, in step 6
At 02, it is determined whether or not the elapsed time after the start of energization reaches a predetermined value time1.

Here, the predetermined value time1 is determined, for example, in advance by an experiment or the like as to the time during which the throttle valve 2 can be reliably released from the state where the throttle valve 2 is fixed at the fully closed position.
s.

The elapsed time from the start of energization is a predetermined value time1.
In step 603, the phase a and the phase b of the reluctance motor 1 are excited with the maximum current. As a result, a torque of about 2 × T ₁ is generated, and it is urged that the throttle valve 2 is released from the state of being fixed at the fully closed position.

The elapsed time from the start of energization is a predetermined time1
Is reached, the routine proceeds to step 604, where the routine shifts to a routine for driving the reluctance motor 1 in the normal mode.
In the normal mode, control is performed to suppress the torque fluctuation generated by the reluctance motor 1.

As another embodiment, the control circuit 19 controls the throttle valve 2 when the reluctance motor 1 starts energizing.
In this configuration, the a-phase and the b-phase capable of continuously generating torque on the opening side of the throttle valve 2 are excited with the maximum current until the opening of the throttle valve exceeds a predetermined value.

FIG. 7 is a flowchart showing a routine for driving the reluctance motor 1.
9 is executed every 5 ms period.

To explain this, first, in step 7
At 02, it is determined whether the current has just started.

If it is determined that power has just been supplied, the routine proceeds to step 703, where the minimum opening X0 of the throttle valve 2 detected by the throttle opening sensor 6 is read.

Next, the routine proceeds to step 706, where the a phase and the b phase of the reluctance motor 1 are excited with the maximum current.

Then, the process proceeds to a step 707, wherein it is determined whether or not the energizing time for exciting the a phase and the b phase of the reluctance motor 1 with the maximum current exceeds a predetermined value time_err.

If the energization time does not exceed the predetermined value time_err, the routine proceeds to step 704, where the minimum opening X1 of the throttle valve 2 detected by the throttle opening sensor 6 is read.

Then, the program proceeds to a step 705, wherein it is determined whether or not the opening | X1-X0 | of the throttle valve 2 reaches a predetermined value Xsl.

Thus, the opening of the throttle valve 2 |
X1-X0│ is to reach a predetermined value Xsl is reluctance motor 1 generates a torque of about 2 × T _1, the throttle valve 2 prompts that to escape from the state of being stuck in the fully closed position.

Opening of throttle valve 2 | X1-X0 |
Has reached the predetermined value Xsl, the routine proceeds to step 709, where the routine shifts to a routine for driving the reluctance motor 1 in the normal mode. In the normal mode, control is performed to suppress the torque fluctuation generated by the reluctance motor 1.

On the other hand, the opening degree | X1-
If the energization time exceeds the predetermined value time_err without X0│ reaching the predetermined value Xsl, the process proceeds to step 708 to set an abnormality flag, and proceeds to step 709 to turn on a warning lamp on a monitor panel (not shown). . Thus, the driver is notified that the throttle valve 2 is stuck at the fully closed position.

As another embodiment, the throttle valve 2 is kept at a predetermined opening other than the fully closed position when the reluctance motor 1 is not energized, and the rotation direction is changed according to the rotor position when the reluctance motor 1 is energized. The maximum current is supplied to the two phases having the same sign of the differential value of the inductance for a predetermined time.

FIG. 8 is a flow chart showing a routine for driving the reluctance motor 1.
9 is executed every 5 ms period.

To explain this, first, in step 8
At 02, it is determined whether or not the elapsed time after the start of energization reaches a predetermined value time1.

The elapsed time from the start of energization is a predetermined time1.
Until the current reaches the step 803, the process proceeds to step 803, where the rotor 34 at the start of energization is supplied by a signal from the rotation angle sensor 37.
Is read. The reading of the rotation angle θ of the rotor 34 is performed only immediately after the start of energization.

The elapsed time from the start of energization is a predetermined value time1.
To step 804 until the rotor 34
If it is determined that the rotation angle θ is in the range of (45 × N) degrees to (45 × N + 15) degrees where N is an integer, the process proceeds to step 806 to excite the c-phase or a-phase with the maximum current. I do.

If it is determined that the rotation angle θ of the rotor 34 is in the range of (45 × N + 15) degrees to (45 × N + 30) degrees where N is an integer, the process proceeds to step 808, where the phase b or phase c is determined. Is excited at the maximum current.

If it is determined that the rotation angle θ of the rotor 34 is other than that, the process proceeds to step 807, and the phase a or phase b is excited with the maximum current. Here, the direction of the generated torque is determined according to the position of the rotor. For example,
When θ = 20 degrees, a positive direction torque is generated by exciting the b phase and the c layer, but when θ = 65 degrees, a negative direction torque is generated by exciting the b phase and the c phase, The throttle valve 2 is driven in a valve closing direction.

As a result, the maximum torque is generated in accordance with the rotation angle θ of the rotor 34, and it is urged that the throttle valve 2 is released from the fixed state at the fully closed position.

The elapsed time from the start of energization is a predetermined time1.
Is reached, the routine proceeds to step 809, where the routine shifts to a routine for driving the reluctance motor 1 in the normal mode.
In the normal mode, control is performed to suppress the torque fluctuation generated by the reluctance motor 1.

As another embodiment, the throttle valve 2 is maintained at a predetermined opening other than the fully closed position when the reluctance motor 1 is not energized. , The maximum current is continuously excited in two phases having the same sign of the differential value of the inductance with respect to the rotation direction until the opening of the throttle valve 2 exceeds a predetermined value.

FIG. 9 is a flow chart showing a routine for driving the reluctance motor 1.
9 is executed every 5 ms period.

To explain this, first, in step 9
At 02, it is determined whether the current has just started.

If it is determined that the current has just been supplied, the routine proceeds to step 903, where the minimum opening X0 of the throttle valve 2 detected by the throttle opening sensor 6 is read.

Subsequently, the routine proceeds to step 906, where the rotation angle θ of the rotor 34 at the start of energization is read from the signal from the rotation angle sensor 37 immediately after the start of energization. The reading of the rotation angle θ of the rotor 34 is performed only immediately after the start of energization.

Subsequently, the routine proceeds to step 907, where the rotor 3
If it is determined that the rotation angle θ of 4 is in the range of (45 × N) degrees to (45 × N + 15) degrees where N is an integer, the process proceeds to step 909, where the c-phase or a-phase is set to the maximum current. Excite.

In step 908, if the rotation angle θ of the rotor 34 is N, the rotation angle θ is (4 × N + 15) degrees to (4
If it is determined that it is in the range up to 5 × N + 30) degrees,
Proceeding to step 911, the phase b or phase c is excited with the maximum current.

If it is determined that the rotation angle θ of the rotor 34 is other than that, the routine proceeds to step 910, where the phase a or phase b is excited with the maximum current. Here, the direction of the generated torque is determined according to the position of the rotor. For example,
When θ = 20 degrees, a positive direction torque is generated by exciting the b phase and the c layer, but when θ = 65 degrees, a negative direction torque is generated by exciting the b phase and the c phase, The throttle valve 2 is driven in a valve closing direction.

As a result, the maximum torque is generated in accordance with the rotation angle θ of the rotor 34, and it is urged that the throttle valve 2 is released from the state of being fixed at the fully closed position.

Subsequently, the routine proceeds to step 904, where the throttle valve 2 detected by the throttle opening sensor 6
Is read.

Then, the program proceeds to a step 905, wherein it is determined whether or not the opening | X1-X0 | of the throttle valve 2 reaches a predetermined value Xsl.

Opening of throttle valve 2 | X1-X0 |
Until the value reaches the predetermined value Xsl, the aforementioned step 9
With the routine current after 07, the reluctance motor 1 generates the maximum torque in accordance with the rotation angle θ of the rotor 34, and urges the throttle valve 2 to come out of the fixed state at the fully closed position.

Opening of throttle valve 2 | X1-X0 |
Has reached the predetermined value Xsl, the routine proceeds to step 912, where the routine shifts to a routine for driving the reluctance motor 1 in the normal mode. In the normal mode, control is performed to suppress the torque fluctuation generated by the reluctance motor 1.

The opening of the throttle valve 2 | X1-
If the power supply time exceeds the predetermined value time_err without X0 | not reaching the predetermined value Xsl, an abnormality flag may be set and a warning lamp (not shown) on a monitor panel may be turned on. As a result, the driver can be notified that the throttle valve 2 is stuck at the fully closed position.

The present invention can be applied not only to the throttle valve but also to an auxiliary air control valve for adjusting the idle speed, an EGR valve for adjusting the exhaust gas recirculation amount, and the like.

[Brief description of the drawings]

FIG. 1 is a system diagram of an engine showing an embodiment of the present invention.

FIG. 2 is a sectional view of the intake air amount adjusting device.

FIG. 3 is a perspective view of the reluctance motor.

FIG. 4 is a circuit diagram of a driving circuit.

FIG. 5 is a characteristic diagram of torque and the like generated by a reluctance motor.

FIG. 6 is a flowchart showing control contents.

FIG. 7 is a flowchart showing another embodiment.

FIG. 8 is a flowchart showing still another embodiment.

FIG. 9 is a flowchart showing still another embodiment.

[Explanation of symbols]

 Reference Signs List 1 reluctance motor 2 throttle valve 3 intake passage 4 return spring 6 throttle opening sensor 19 control circuit 20 accelerator opening sensor

Claims (8)

[Claims] 1. An intake air amount adjusting device for an engine, comprising: a return spring for urging an air throttle valve in a valve closing direction; and a reluctance motor for rotatingly driving the air throttle valve, wherein the air throttle valve has a minimum opening degree. An intake air amount adjusting device for an engine, characterized in that the reluctance motor is at a rotational position where the maximum torque can be generated on the opening side of the air throttle valve when the motor is in the vicinity. 2. A motor according to claim 1, further comprising a three-phase reluctance motor for driving the air throttle valve to rotate, wherein an excitation phase capable of generating torque of the reluctance motor on the opening side of the air throttle valve when the air throttle valve is at a minimum opening degree. It is assembled so as to have a predetermined two-phase, and has a start-up control means for supplying a maximum current to a predetermined two-phase which can generate a torque on the opening side of the air throttle valve when the reluctance motor is energized. The engine intake air amount adjusting device according to claim 1. 3. The start-up control means is configured to supply a maximum current to a predetermined two phases that can generate a torque on the opening side of the air throttle valve continuously for a predetermined time time1 at the start of energization of the reluctance motor. 3. The intake air amount adjusting device for an engine according to claim 2, wherein: 4. A start-up control means for detecting an opening degree of the air throttle valve, wherein the start-up control means sets the opening degree of the air throttle valve to a value exceeding a predetermined value at the start of energization of the reluctance motor, or the opening degree before the start of energization. 3. The engine according to claim 2, wherein a maximum current is supplied to two predetermined phases that can generate torque continuously on the open side of the air throttle valve until the difference between the two degrees exceeds a predetermined value. Intake air volume adjustment device. 5. An intake passage for guiding air taken into the engine, an air throttle valve rotatably interposed in the intake passage to adjust the amount of air taken into the engine, and rotating the air throttle valve. And a means for detecting a rotor position of the reluctance motor, wherein the sign of the differential value of the inductance with respect to the rotation direction according to the rotor position at the start of energization of the reluctance motor is the same. An intake air amount adjusting device for an engine, comprising: a start-up control means for supplying a maximum current to the two phases. 6. The start-up control means is configured to supply a maximum current continuously for a predetermined time1 to two phases having the same sign of the differential value of the inductance with respect to the rotation direction at the start of energization of the reluctance motor. The engine intake air amount adjusting device according to claim 5, characterized in that: 7. A start-up control means for detecting an opening degree of the air throttle valve, wherein the start-time control means includes a two-phase air throttle valve having the same sign of the differential value of inductance with respect to the rotation direction at the start of energization of the reluctance motor. 6. The engine according to claim 5, wherein the maximum current is continuously supplied until the opening of the engine exceeds a predetermined value or until the difference from the opening before the start of energization exceeds the predetermined value. Intake air volume adjustment device. 8. An elapsed time after the start of energization of the reluctance motor is set to a predetermined value time_err while the opening of the air throttle valve does not exceed a predetermined value or the difference from the opening before the start of energization does not exceed a predetermined value. 8. The apparatus according to claim 4, further comprising means for judging an abnormal time exceeding the predetermined value.