JPH05240070A - Throttle actuator and intake air quantity controller of internal combustion engine - Google Patents

Abstract

PURPOSE:To produce a sufficient force simply and accurately without increasing the selection of pole numbers and rotation and requiring a high precision detector by transmitting the rotation of a rotor being rotated by a magnetic flux variation in stator winding to a throttle valve after being decelerated. CONSTITUTION:A throttle valve 4 is supported by a bearing 40 in an intake passage 2 of an internal combustion engine, while in the passage 2 a return spring 29, energizes this valve so as to put back in the closing direction, and a sensor 28 detects this opening. On the other hand, a throttle actuator 5 is equipped with a brushless motor 25 which is composed of a stator 23 consisting of a stator core 39 wound with a stator winding 42 and a magnetic rotor 24 consisting of a permanent magnet. In addition, the brushless motor 25 varies a current to the stator winding 42 by an output signal out of a pole position detector 27. In this case, a rotation of the magnetic rotor 24 is transmitted to the throttle valve 4 after being decelerated by a gear or a speed reducing means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle actuator for rotating a throttle valve arranged in an intake passage of an internal combustion engine, and intake air amount control means for controlling an intake air amount supplied to the internal combustion engine.

[0002]

2. Description of the Related Art A throttle valve is arranged in an intake passage for supplying intake air to an internal combustion engine. Traditionally, this throttle valve has been mechanically connected to the accelerator pedal by a wire. However, in recent years, attempts have been made to control a throttle valve with a motor or the like for control such as traction control and auto cruise, and for purification of exhaust gas and improvement of fuel consumption. As an example of this, as is known from Japanese Patent Laid-Open No. 62-91640, a technique for controlling a throttle valve by connecting a throttle valve to a DC machine through a gear and operating a voltage applied to the DC machine. There is.

A DC machine supplies a current to the armature winding via a brush commutator to generate a rotational force with the permanent magnet field. Since the brush is pressed against the rotor in this way, hysteresis friction occurs in the forward rotation direction and the reverse rotation direction of the DC machine, making it difficult to control the position of the throttle valve. Further, since the armature was pressed, the DC machine did not start rotating unless the force to overcome this force was generated, and the reaction characteristics were poor.

Therefore, it has been conceived to open and close the throttle valve by using a brushless motor (AC machine) that rotates a rotor without using a brush. Such a technique is described in JP-A-1-315641 and the like. In the one disclosed in this publication, the throttle valve is directly fixed to the rotor of the brushless motor.

[0005]

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention
In the technique described in Japanese Patent No. 1, since the throttle valve is directly fixed to the rotor of the brushless motor,
In order to increase the force generated by the motor, the number of poles must be increased. When the number of poles of the brushless motor is increased, the current supplied to the fixed winding due to the rotation of the rotor must be switched at a fine angle, which becomes remarkable especially when the motor rotates at high speed. However, there is a problem that the control of switching the current cannot be sufficiently followed. Moreover, since the angle of the rotor for switching the current becomes small, a highly accurate motor rotation angle detector is required.

A first object of the present invention is to provide a throttle actuator for an internal combustion engine and an intake air for the internal combustion engine in which the angle of switching the current to the winding element is not small and a highly accurate motor rotation angle detector is not required. It is to provide a quantity control device.

Further, generally, in order to reduce iron loss, punched silicon steel sheets are laminated and used for the stator core around which the stator winding of the conventional brushless motor is wound. However, since they are laminated, air enters in the axial direction to form a magnetic resistance. Therefore, there is a problem that the output of the brushless motor is lowered and the responsiveness is lowered.

A second object of the present invention is to provide a throttle actuator for an internal combustion engine which eliminates the reduction in output of the brushless motor and has sufficient responsiveness.

Further, in the conventional brushless motor, generally, the stator core of the stator and the magnet of the magnet rotor are formed to have the same distance in the axial direction. A winding is wound around the stator core, but when the winding is wound, the axial distance of this winding becomes longer than the axial distance of the magnet. Then, the magnetic flux generated by the stator winding is not effectively used, the output of the brushless motor is reduced, the force is not produced, and the responsiveness is reduced.

A third object of the present invention is to provide a throttle actuator for an internal combustion engine which eliminates the reduction in output of the brushless motor and has sufficient responsiveness, like the second object.

Further, in the technique described in the above-mentioned JP-A-1-315641, the four-pole magnet is fixed to the output shaft of the rotor,
This magnet is detected by a detection element, and the current supplied to the stator is switched based on the output of this detection element. However, in order to accurately switch the voltage supplied to the stator when the brushless motor rotates at a high speed, it is necessary to improve the working accuracy of the magnet and to accurately match the magnet and the rotor.

A fourth object is to provide an intake air amount control device in which a signal for switching the current supplied to the stator of the brushless motor can be obtained relatively easily.

Further, in the technique described in the above-mentioned Japanese Patent Laid-Open Publication No. 1-315641, the current supplied to the stator of the brushless motor is switched by logically operating the detection signal of the detection element. As described above, since the current supplied to the brushless motor is switched by performing a logical operation or the like on the output of the detection element, at least a device for performing a logical operation is required, which is complicated and expensive.

A fifth object is to provide an intake air amount control device which is simple and inexpensive for switching the current supplied to the brushless motor.

Further, in the above-mentioned prior art, sufficient attention has not been paid to the detection of a failure.

A sixth object is to provide an intake air amount control device for an internal combustion engine capable of detecting a failure.

[0017]

In order to achieve the first object, according to a first aspect of the present invention, a stator winding, a rotor rotating by a change in magnetic flux of the stator winding, and an internal combustion engine are provided. In a throttle actuator of an internal combustion engine having an intake passage for supplying intake air and a throttle valve arranged in the intake passage to increase or decrease the intake air, a deceleration means for decelerating rotation of the rotor and transmitting it to the throttle valve. Is configured to have.

In order to achieve the second object, in the second invention, a magnet rotor in which a magnet is arranged around an axis, a stator winding for giving a magnetic flux to the magnet rotor, and an intake coil for an internal combustion engine are provided. In a throttle actuator of an internal combustion engine having an intake passage for supplying air and a throttle valve that is rotated by the magnet rotor to increase and decrease intake air, a stator core around which the stator winding is wound is axially arranged. Composed of continuous metal.

In order to achieve the third object, in the third invention, a magnet rotor in which a magnet is arranged around an axis, a stator winding for giving a magnetic flux to the magnet rotor, and an intake coil for an internal combustion engine are provided. In a throttle actuator of an internal combustion engine having an intake passage for supplying air and a throttle valve that is rotated by the magnet rotor to increase or decrease intake air, portions in which axial lengths of winding portions of the stator core are opposed to each other. It is configured to be shorter than the axial length of the magnet rotor.

In order to achieve a fourth object, in the fourth invention, a stator winding, a rotor that rotates by a change in magnetic flux of the stator winding, and an intake air that supplies intake air to an internal combustion engine. In the intake air amount control device for an internal combustion engine, which includes a passage, a throttle valve arranged in the intake passage to increase and decrease intake air, and a throttle control unit for controlling the throttle valve, the stator winding is generated. The throttle control unit has a counter electromotive voltage detector for detecting a counter electromotive voltage, and the throttle control unit is configured to control the throttle valve based on an output of the counter electromotive voltage detector.

In order to achieve the fifth object, in the fifth invention, a stator winding, a rotor that rotates by a change in the magnetic flux of the stator winding, and an intake air that supplies intake air to an internal combustion engine. An intake air amount control device for an internal combustion engine, comprising: a passage; a throttle valve arranged in the intake passage to increase or decrease intake air; and a throttle control unit for supplying a current to the stator winding. The throttle control unit is configured to supply a current to the stator winding when an output of the current switching detector is present, the current switching detector indicating a point of time when the current is supplied to the line.

In order to achieve the sixth object, according to the sixth aspect of the invention, drive means for generating a rotational force, an intake passage for supplying intake air to the internal combustion engine, and intake air arranged in the intake passage are provided. A throttle valve for increasing and decreasing the throttle valve, and a throttle control unit for controlling the driving means. In an intake air amount control device for an internal combustion engine, a deceleration means for decelerating the rotation of the driving means and transmitting the deceleration to the throttle valve; Detecting means for detecting the start of opening from the fully closed state, second detecting means for detecting the rotation angle of the driving means in response to generation of a detection signal from the first detecting means, and It is configured to have a first abnormality detecting unit that detects an abnormality based on the output of the second detecting unit.

Further, a sixth object is, as in the seventh invention, a drive means for generating a rotational force, an intake passage for supplying intake air to an internal combustion engine, and the drive means for rotating the intake air. In an intake air amount control device for an internal combustion engine having a throttle valve that increases and decreases and a throttle control unit that controls the drive means, a third detection means that detects a rotation angle of the drive means, and an opening degree of the throttle valve. It is also possible to have a fourth detection means for detecting the above and a second abnormality detection means for comparing the output of the fourth detection means with the output of the fourth detection means to detect an abnormality. Can be achieved.

[0024]

According to the first configuration, the rotation of the rotor is transmitted as the rotational force of the throttle valve via the speed reducing means.
Therefore, a sufficient force can be generated without increasing the number of magnetic poles, and the current switching control can be sufficiently followed. Further, it is not necessary to reduce the angle of the rotor that switches the current, and it becomes possible to eliminate the need for a highly accurate motor rotation angle detector.

According to the second structure, since the stator core of the stator winding is composed of a continuous body of iron, the stator core can be structured so as not to form a gap in the axial direction. , The magnetic flux generated in the stator winding can be used effectively, and the throttle valve can be moved quickly to the target opening.

According to the third structure, since the axial length of the winding portion of the stator core is made shorter than the axial length of the magnet rotor of the facing portion, the winding wound around the stator core. The axial length of the rotor and the axial length of the rotor magnet can be made almost the same, the magnetic flux generated in the winding can be used effectively, and the throttle valve can be quickly opened to the target opening. It becomes possible to move.

According to the fourth structure, the throttle control unit controls the throttle valve based on the output of the counter electromotive voltage detector. Therefore, it becomes possible to switch the current supplied to the stator of the brushless motor without providing a complicated detection device.

According to the fifth configuration, the signal of the current switching detector can be used as it is as the switching signal of the voltage supplied to the stator of the brushless motor. In this way, since the signal of the detector can be used as it is as the control signal, a simple and inexpensive intake air amount control device can be obtained.

According to the sixth configuration, the abnormality can be detected by the rotation angle of the driving means when the throttle valve starts to open from the fully closed state.

According to the seventh configuration, the abnormality can be detected by comparing the rotation angle of the driving means and the opening degree of the throttle valve.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. First, a system configuration diagram of this embodiment is shown in FIG. The intake air taken in through the air cleaner 10 is controlled by the throttle valve 4 provided in the throttle chamber 6, and is guided to the cylinder of the engine 1 through the intake passage 2. On the other hand, the fuel supplied from the injection valve 16 is mixed with the intake air to form an air-fuel mixture, which is guided to the cylinder of the engine 1. The air-fuel mixture is discharged to the outside from the exhaust passage 3 after the compression and explosion strokes.

The depression amount ACC of the accelerator 9 is measured by the accelerator sensor 8, and the water temperature TM of the engine 1 is measured by the water temperature sensor 1.
2, the rotation angle NP of the crankshaft 18 is determined by the crank angle sensor 13, and the rotation angle PF of the throttle valve 4 is determined by the crank angle sensor 13.
Is the throttle opening sensor 17, and the rotation speed VF of the front wheels and the rotation speed VR of the rear wheels are
20 and the respective detection signals are input to the control unit 14. The engine control unit 14 calculates the intake air amount by calculating the signals from the sensors. Further, the engine control unit 14 drives the throttle actuator 5 on the basis of this calculation result to control the intake air. Further, the intake air amount QA actually supplied to the engine is detected by the intake air amount sensor 7, and this signal is input to the engine control unit 14. The engine control unit 14 calculates the fuel supply amount Ti based on the output signal of the intake air amount sensor 7 and drives the injection valve 16 to control the fuel supply.

Although details will be described later, in this embodiment,
A brushless motor is used as the motor of the throttle actuator 5, and the throttle valve 4 is opened and closed by supplying a current to the stator winding (three phases) of this motor.

Details of the engine control unit 14 are shown in FIG. The engine control unit 14 is the fuel control unit 2
1 and the throttle control unit 22.
The fuel control unit 21 calculates and outputs the fuel supply amount Ti and the throttle opening designation PS based on the output of each sensor. On the other hand, the throttle control unit 22 uses the throttle opening command PS, the magnetic pole position MP of the brushless motor, and the current value I of the brushless motor to output the duty PWM of the current to the brushless motor and the switching signal for each phase of the rotor of the brushless motor. The throttle actuator 5 is driven by calculating A, B and C.

Details of the throttle actuator 5 and the throttle control unit 22 are shown in FIG. The brushless motor 25 (three phases) is composed of a stator 23 and a magnet rotor 24. A reduction gear 26 is provided on the central axis of the magnet rotor 24.
Are connected. As a result, the torque of the magnet rotor 24 is transmitted to the throttle valve 4. The rotation of the magnet rotor 24 is detected by the magnetic pole position detector 27.
The throttle valve 4 is biased in the closing direction by the return spring 29. The voltage of the power supply 31 is controlled by the driver 30 and supplied to the stator 25. The current I is detected by the current detector 32.

The throttle control unit 22 is composed of an input section composed of A / D converters 33 and 35 and a waveform shaper 34, and a one-chip microcomputer 38. The one-chip microcomputer 38 functionally has the two functions of the magnetic pole detection means 36 and the throttle opening control means 37. The output I of the current detector 32 is passed through the A / D converter 35, and the output PF of the throttle opening sensor 28 is passed through the A / D converter 33.
Input to 7. The throttle opening control means 37 has a throttle opening command PS (output from the fuel control unit 21),
PW based on the throttle opening PF and the motor current value I
M is calculated and output to the driver 30. The output of the magnetic pole position detector 27 is waveform shaped by the waveform shaping circuit 34 and input to the magnetic pole position detecting means 36. The magnetic pole position detection means 36 outputs the phase switching signals A, B, C of the stator 23 to the driver 30 based on the signals (A, B, C). The brushless motor 25 has a gear ratio of 8 and four poles. In other words, the valve opening is approximately 90 degrees in two rotations. Here, a 120-degree energization type permanent magnet brushless motor is used. The upper and lower energization patterns of each arm of the driver 30 are assigned based on the positional relationship between the stator 23 and the magnet rotor 24. The energization mode for each arm is a cycle of one electrical angle. The brushless motor 2
If 5 is 4 poles, the frequency will be smaller than that of 8 poles or more, so iron loss will be reduced, the number of windings will be smaller, and magnetization will be easier, so the amount of magnetic flux will be larger and used for servo. The inertia becomes smaller. The two poles further improve the performance.

Here, the gear 26 is used to increase the driving force of the brushless motor 25. this is,
Especially, since the control of the throttle valve is position control,
It is necessary to constantly supply a current to the brushless motor 25 to control the opening of the throttle valve 4, and the force of the return spring 29 must be strengthened in order to speed up recovery in the event of a failure. In the direct connection method, the torque is small and the motor size is large,
Power consumption increases. This is because there is such a problem.

The details of the throttle actuator 5 are shown in FIG.
Shown in. A throttle valve 4, which is supported by a bearing 41 in the intake passage 2 that guides air to the engine, controls the amount of air by rotating in a range of about 90 degrees, and an attempt to always return the throttle valve 4 in the closing direction. Throttle spring sensor 28 indicating the opening of the return spring 29 and the throttle valve 4 for generating the force
And a throttle valve 4 via a gear 26 which is a converter.
And a brushless motor 25 that generates a force to open and close the. Here, as the brushless motor 25, a permanent magnet type three-phase brushless motor is used. The brushless motor 25 is composed of a stator 23 composed of a stator core 39 around which a stator winding 42 is wound, and a magnet rotor 24 composed of a permanent magnet. The brushless motor 25 changes the current to the three-phase stator winding 42 according to the output signal of the magnetic pole position detector 27. Also, this magnet rotor 2
4 is connected to the gear 4 and is supported via a bearing 40.

The details of the stator 23 and the rotor 24 of the brushless motor 25 are shown in FIG. The brushless motor 25 includes a stator 23 mainly composed of a dust core and a stator winding 42 wound around a stator core 39, and a rotor 24 (N, S, N, S) composed of permanent magnets. ) And. Here, the axial length of the winding portion of the stator core 39 is
The configuration is made shorter than the permanent magnet side (inner diameter side) facing this. As a result, the length of the winding can be shortened, power consumption can be reduced, and the total length of the motor can be shortened.

In the stator core 39 of the brushless motor, conventionally, thin silicon steel plates are punched and laminated for use. This is to reduce iron loss at high speeds. On the other hand, since the maximum movement angle of the throttle actuator is 90 degrees, the operation during high-speed rotation is
It is a short time, the use of the dust core is not disadvantageous, and further, low power consumption and miniaturization can be achieved as described above. Further, in the inner-rotation type motor of the laminated core, the circular core on the inner side after punching out the stator core 42 is not used, which is wasteful, but the dust core is economical because there is no waste of material.

The details of the magnetic pole position detector 27 are shown in FIG.
The magnetic pole position detector 27 includes a position detecting rotor 50 and Hall elements 51 to 53. The position detecting rotor 50 is composed of four-pole magnets (N, S, N, S) and is rotated integrally with the magnet rotor 24. Hall elements 51 to 53 are arranged around the position detecting rotor 50 at every 120 degrees (mechanical angle). The Hall elements 51 to 53 are position detecting rotors 50.
Detected the rotational position of A phase, as shown in FIG.
Outputs B-phase and C-phase. Further, the Hall elements 51 to
The output of 53 is shaped by the waveform shaping circuit 34 into a pulse-shaped signal as shown in FIG.

The details of the driver 30 are shown in FIG. As described above, the throttle control unit 22 inputs the signals PF, PS and I to the analog input ports AN0 to AN2, respectively, to generate the PWM signal, and the magnetic pole position detector 27.
In response to the outputs A, B, and C, the switching signals A, B, and C for each phase are generated. The switching A, B, and C signals of each phase of the throttle control unit 22 are transmitted to the inverter 54a,
It is input to 54b and 54c. This inverter 54a,
The outputs of 54b and 54c are AND gates 55a and 55b,
55c is input to one side. AND gate 55a, 55
The P and M signals are input to the other of b and 55c. The outputs of the AND gates 55a, 55b, 55c are resistors 57a, 5
Drive transistors 59a, 59 via 7b, 57c
It is input to the bases of b and 59c. The emitters of the drive transistors 59a, 59b, 59c are input to FETs (upper arms) 61a, 61b, 61c. Inverter 5
The outputs of 4a, 54b, 54c are NAND gates 58a, 5
It is input to one of 8b and 58c. Nand Gate 58
The other of a, 58b and 58c is the throttle control unit 2
The switching A, B, and C signals of the respective phases output by 2 are input. The outputs of the NAND gates 58a, 58b, 58c are input to the bases of the drive transistors 60a, 60b, 60c via the resistors 63a, 63b, 63c. The drive transistors 60a, 60b, 60c have emitters of F
Input to ET (lower arm) 62a, 62b, 62c.
In FIG. 7, the output signal of the magnetic pole position detector 27 (waveform shaping circuit 34) and the FETs (upper arms) 61a, 61b, 6 are shown.
1c and the switching states of the FETs (lower arms) 62a, 62b, 62c are shown. In this figure, the expressions A, B, and C indicate that the switching of the FET of each phase is in the ON state. If not expressed, it indicates that the switching state of the FET of each phase is off. Explaining with an example, when the magnetic pole position detector 27 is outputting as shown in (a) of FIG. 7, the FETs 61a to 61c (upper arm).
Among them, only 61c (C phase) is on, and other FETs
(Upper arm) 61a (A phase) and 61b (B phase) are in the off state. In addition, FETs (lower arms) 62a to 62
In c, only 62b (B phase) is on, and the other FETs (lower arm) 62a (A phase) and 62c (C phase) are off.

As described above, the driver 30 first performs AND, NAND, and NAND signals from the ABC signal which replaces the magnetic pole position detection signal.
The INV logic produces signals that control the upper and lower arms of the FET. In this case, the signal of the upper arm is the PW calculated by the one-chip microcomputer 14.
The M signal is superimposed. Furthermore, this signal is FET
(Upper arm) drive transistors 59a, 59b,
59c and the drive transistors 60a, 60b, 60c of the FET (lower arm), respectively.

Next, the calculation operation of the throttle control unit 22 will be described with reference to the flow charts of FIGS. 9 to 11. First, the operation of calculating the PWM duty is shown in FIG.
Shown in. First, in step 901, it is determined whether the current value I detected by the current detector 32 is larger than a predetermined value IC. If the current value I is larger than the predetermined value I, the overcurrent is FETs 61a to 6
1c, 62a to 62c, so step 907
Then, the process proceeds to step S6 and the predetermined amount L (quite large) is subtracted from the previous PWM duty, and this flow is ended. Step 901
If the overcurrent is not detected in step 902, the throttle-related command PS from the fuel control unit 21 is fetched in step 902, and further, in step 903, the throttle opening sensor 2
The detection value PF of 8 is fetched. Deviation PE in step 904
And the PWM duty is calculated in step 905. In step 906, this calculated value is set in the register and output. Although an example of proportional control is shown here, PID control is adopted as necessary. Moreover, you may put speed control in a minor loop. Here, K is a proportional constant of control. The frequency of the PWM signal is determined in consideration of noise of the motor, switching loss of the transistor, and the like.

Next, FIG. 10 shows the calculation of the throttle opening based on the output of the magnetic pole position detector 14 and the failure diagnosis based on the calculation. First, in step 1001, the pulses A, B, and C (three phases) obtained by shaping the output of the magnetic pole position detector 27 are acquired. In step 1002, it is determined whether there is a change in any of the signals A, B and C. If there is no change, jump to step 1006. On the other hand, step 10
If it changes to any of the signals A, B, and C at 0, it is judged at step 1003 whether it is normal rotation or reverse rotation. If it is normal rotation, the C counter is incremented by 1 at step 1004, and if it is reverse rotation. In step 1005, the value is decremented by 1, and the process proceeds to step 1006. In step 1006, the inference value THE of the throttle opening is calculated based on the C counter value.
Ask for TA. When the actual throttle opening PF is acquired in step 1007, the throttle opening PF is acquired in step 1008.
Judge whether is zero. If it is zero, failure diagnosis is not performed. If the actual throttle opening PF is not zero in step 1009, the actual throttle opening PF and the inferred value THE
Fault diagnosis is performed based on TA. That is, if the actual throttle opening PF and the inferred value THETA are more than a predetermined value (C), it is determined that there is a failure and the flag NGFLAG indicating failure is set to 1 in step 1010. Also, step 10
If no failure is recognized in 09, the process proceeds to step 1011. Finally, the pulse detected by the magnetic pole position detector 27 is used as it is as the switching signals A, B, C of each phase and the driver 3
Output to 0.

Next, FIG. 11 shows a failure diagnosis when the throttle opening is zero. First, in step 1101, it is determined whether the throttle valve 4 is loaded by the brushless motor 25 (whether the throttle valve 4 is sufficiently biased by the return spring 29). 11
In 01, it is judged whether the actual throttle opening is zero.
It is determined whether the M duty is zero. If the conditions are not satisfied even on the other hand, the process directly proceeds to step 1104. When both of the conditions are satisfied, the flag CFLAG indicating the failure diagnosis capability is set to 1 in step 1103. In step 1104, it is determined whether CFLAG is 1. If CFLAG is not 1, the flow ends as it is.

Here, the method of failure diagnosis shown in the flowchart of FIG. 11 will be briefly described. The movement range of the advance angle due to the rotation of the brushless motor 25 with the opening of the throttle valve being zero depends on the backlash of the gear 26.
Is the range that can be moved. This is shown in FIG.
That is, in other cases than the above, the brushless motor 25 receives a force in the closing direction due to the force of the return spring 29 and has no rattling, but within the range of the rattling movement angle of the gear 26, the throttle valve 4 is provided with a stopper (not shown). However, since the stopper receives all the force of the return spring 29, the brushless motor 25 can move by the amount of the backlash of the gear 26. Especially, when the gear ratio is large, this distance becomes large. Focusing on this range, an appropriate drive torque is applied to the brushless motor 25 in the closing direction or the opening direction before and after the engine is started. As a result, the brushless motor 25 moves, and as a result, a switching signal for switching between the upper arm and the lower arm is generated every 60 electrical degrees, as shown in FIG. The number is counted, and when it reaches a predetermined number, it can be determined that the brushless motor 25 and the drive device are sound. Furthermore, by checking whether the order of the energization modes is maintained during this period, the soundness of the driver 30, the magnetic pole position detector 27, etc. can be further confirmed, and the reliability of the diagnosis can be further enhanced.

In step 1105, it is determined whether CFLAG is 1. If CFLAG is not 1, this flow ends. If CFLAG is 1 in step 1105, it is determined in step 1105 whether the previous actual throttle opening PF was zero. If it is not zero, this flow ends. In step 1105, the previous actual throttle opening P
If F is not zero, it is determined in step 1106 whether the actual throttle opening PF this time is larger than zero. If it is not greater than zero, this flow ends. If the actual throttle opening PF this time is larger than zero in step 1106, it is judged in step 1007 whether the C counter is larger than a predetermined value CN. If it is larger, it is determined that the entire throttle actuator 5 is normal, and in step 1009 CFLAG is returned to zero again, and this flow is ended. Step 1007
If the C counter is not greater than CN, it is determined that there is a failure, and NGFLAG is set to 1 in step 1008. Step 1
In step 009, CFLAG is returned to zero, and this flow ends.

Further, the effect of this embodiment will be described. The torque Tmotor generated by the brushless motor 25 is expressed by the following equation.

Tmotor = Tacc + Tsp + Tfr (1) Here, Tacc represents torque for accelerating the throttle valve by overcoming the inertia of the motor, gear, and valve. Tsp is the torque to balance the force of the spring, T
fr represents the friction torque of the throttle system including the actuator. In the conventional DC machine system, particularly, a system using a gear, the value of Tfr becomes particularly large due to the frictional force between the brush and the commutator. Since this friction torque has a hysteresis characteristic, positioning becomes difficult. Further, when viewed from the valve side, this is a multiple of the gear ratio of the actual friction torque, so the friction torque viewed from the valve side becomes large and positioning becomes difficult. Also, the presence of the friction torque has a drawback that it takes a long time to return the valve to the closed state when the throttle valve actuator fails. In practice, it is necessary to return the spring within a certain time, so it is necessary to increase the strength of the spring used, and there is also a drawback that the motor is made larger than necessary. The disadvantage of using a DC machine as the gear ratio is increased is large, and the effect becomes more remarkable when the gear ratio is 5 or more.

Furthermore, a stator core 3 which uses a dust core material as the stator core 39 and is used together with the dust core material
By forming 9 as a shape having different axial lengths, it is possible to configure an efficient motor and reduce performance deterioration.

Further, although it is important to reduce the friction torque of the entire device, by using a crane-shaped spring as shown in FIG. 1 as the return spring 29 that acts in the closing direction of the throttle valve 4, the entire throttle device can be used. The friction torque of can be reduced.

As shown in FIGS. 1 and 2, the brushless motor 25, the output torque of the brushless motor 25 are amplified, and the meshing type gear 26 and the throttle valve 4 are arranged on substantially the same straight line. Also, the friction torque of the entire throttle actuator can be reduced.

The second embodiment will be described with reference to FIGS. 13 to 15. In the second embodiment, a magnetic pole position detector that outputs linearly with respect to the rotation angle is used. In the first embodiment, the driver 30 includes the FETs 61a to 61c and 62a to 62.
Although the energization mode of c has been determined, in the second embodiment, the throttle control unit 22 uses the FETs 61a to 61c, 62.
The energization modes a to 62c are calculated. In FIG.
The outputs of the A, B, and C phases (upper arm) of the throttle control unit 22 are input to AND gates 55a to 55c, respectively. PW is provided at the other ends of the AND gates 55a to 55c.
M output is input. Also, the throttle control unit 2
The outputs of the A, B, and C phases (lower arm) of 2 are directly applied to the bases of the drivers 60a to 60c. The output of the magnetic pole position detector 27 is input to the analog input port AN3 of the throttle control unit 22, and the throttle control unit 22 is A / D converted and taken into a one-chip microcomputer.

Next, the operation will be described. In place of the operation shown in the flowchart of FIG. 10 of the first embodiment, FIG.
The operation shown in the flowchart of 4 is performed. Step 14
At 01, take in the motor rotation angle PM. Step 1402
FETs 61a to 61c corresponding to the motor rotation angle PM,
62a to 62c energization mode (switching signal A for each phase,
B, C) are calculated. In this case, the energization mode for the motor rotation angle PM as shown in FIG. 15 is stored in the ROM in advance and is read out.

Since the other parts are the same as those in the first embodiment, the description thereof will be omitted.

A third embodiment will be described with reference to FIGS. 16 to 17. In the third embodiment, the throttle opening sensor 2
FETs 61a to 61c, 62a based on the output PF of 8
The energization modes of ~ 62c are calculated. The throttle control unit 22 performs the operation shown in the flowchart of FIG. 16 instead of the operation shown in the flowchart of FIG. That is, in step 1601, the output PF of the throttle opening sensor 28 is fetched. In step 1602, the energization modes of the FETs 61a to 61c and 62a to 62c are calculated based on the detected value RF. That is, the FETs 61a to 61c and 62a to 6 for the throttle opening RF as shown in FIG.
The energization mode of 2c is stored in the ROM in advance, and the stored value is read from this ROM. Step 14
At 03, A, B and C are output to the driver 10.

Since the other parts are the same as those in the second embodiment, the description thereof will be omitted.

Next, a fourth embodiment will be described. In the fourth embodiment, the rotational position of the brushless motor 25 is detected. The opening speed of the throttle actuator valve is 0 to 90 degrees and performance of 0.1 second or less is required. On the other hand, it is advantageous to increase the number of poles for increasing the torque of the permanent magnet brushless motor, and four or more poles may be selected. In this case, assuming that the speed linearly increases from 0 to 45 degrees and linearly decreases from 45 to 90 degrees, it is estimated that the maximum number of rotations reaches about 3000. An electrical angle of 60 hours at this speed is approximately 50
It becomes 0 μs, and at least 5 out of 60 electrical angle is needed to find the timing of switching 60 electrical angle by software.
The above sampling is required. In order to achieve this, it is necessary to use a high-speed microprocessor, and there is the inconvenience that processing of the system other than detection of the energization mode becomes impossible. As the number of revolutions increases,
The time required for an electrical angle of 60 degrees becomes shorter. As a control method for compensating for the above-mentioned drawbacks, it is possible to provide a mechanism for generating the timing of switching the energization to each phase winding of the brushless motor on the motor side or the opening degree sensor side at a high rotational speed. This may be used as an interrupt signal to switch to the control arithmetic unit. In the embodiment, the back electromotive voltage of the motor is used, and the timing of the phase change of 60 electrical degrees is detected by hardware.

The detailed structure of the back electromotive voltage position detector 73 is shown in FIG.
8 (a). The voltage of each phase of the winding is input to one of the comparators 71a to 71c via the first-order lag filter 70, and the other side is connected to a neutral point star-connected from the winding of each phase via a resistor. .. The potential of the star-connected neutral point becomes the average value of each phase voltage, and by comparing this with the winding voltage of each phase, it is possible to find the phase switching point at an electrical angle of 60 degrees. The output of each comparator is shown in FIG.
As shown in (b) and (c), a rectangular wave signal having a phase difference of 120 degrees is obtained, and these three rectangular wave signals are converted into the rising and falling detectors 72.
A signal with an electrical angle of 60 degrees is shown in the diagram in Figure 1.
8 (b) (d) can be synthesized. By using this signal as an interrupt signal of the one-chip microcomputer 38, it is possible to instantaneously switch the energization mode at a phase change angle of 60 electrical degrees. At this time, the data of the energization mode of the phase change angle of 60 electrical degrees may use the data of the back electromotive force position detector or may indicate the energization information from the throttle opening sensor 28.

Throttle control unit 2 of the fourth embodiment
The operation of No. 2 will be described. In the fourth embodiment, FIG. 1 is used instead of the operation shown in the flowchart of FIG. 16 of the third embodiment.
The operation shown in the flowchart of 9 is performed. When the pulse generated by the counter electromotive voltage detector 72 is input to the IRQ terminal of the one-chip microcomputer 38, it is determined in step 1901 whether it is normal rotation.
At 2, the D counter is incremented by 1, and this flow ends. On the other hand, if it is not determined to be normal in step 1901, D
The counter is decremented by 1, and this flow ends.

In another routine, step 19
At 10, it is determined whether the rotation speed is larger than the predetermined value NS. If it is larger than the predetermined value NS, the energization mode of each arm is calculated according to the D counter. That is, D shown in FIG.
The energization mode for the counter is stored in the ROM in advance, and the energization mode is obtained by reading this. When the rotational speed is not higher than the predetermined value NS in step 1910, the output RF of the throttle sensor 28 is fetched. Further, in step 1911, the energization mode of each arm is obtained based on the actual throttle opening RF (similar to the third embodiment). In step 1912, the switching signals A, B, C for each phase are output, and this flow ends.

Next, a fifth embodiment will be described. The fifth embodiment uses a magnetic pole position detector 27 in which the brushless motor 25 generates a pulse every 15 degrees (mechanical angle). The details of the magnetic pole position detector 27 are shown in FIG. Rotating body 27 having 24 protrusions every 15 degrees over the entire circumference
Is detected by the detection coil 76. The detection coil 76 outputs a signal as shown in FIG. 21B, and the waveform shaping circuit 77 shapes the waveform to generate a pulse as shown in FIG. 21C.

In the fifth embodiment, this waveform shaping circuit 77 is used.
Output pulse of one-chip microcomputer 3
8 (Interrupt (IRQ)), this pulse is counted D, the rotation angle of the brushless motor is calculated by counting down and counting down, and based on this, A,
The signals of the B and C phases are output to the driver 20 (the steps 1910, 1911 and 1912 are omitted in FIG. 19).

Next, a sixth embodiment will be described with reference to FIG. In the sixth embodiment, a variable reluctance type rotor 78 is used instead of the permanent magnet rotor 32. Here, the rotor 78 is shown as an example of a salient pole shape made of a magnetic material. The permanent magnet rotor 32 is based on the principle of utilizing the attraction and repulsion between the magnetic pole created by the stator winding and the permanent magnet rotor, while this is the magnetic pole created by the stator winding and salient pole rotation. Although only the suction force of the child is used, the efficiency is poor, but the motor has a simple structure and a low price. Since this structure also has no friction torque due to sliding, the same effect as described above can be expected. Further, the need for the magnetic pole position detector is the same as in the case of the permanent magnet rotor. The other parts are the same as those in the first to fifth embodiments and will not be described.

The reliability of the throttle actuator is very important for controlling the heart of the automobile engine. For this reason, it is possible to provide a clutch on the output shaft of the motor so that when the motor locks and does not move, the clutch disconnects the motor from the valve, and the accelerator wire provided separately can be used for control. In this case, when the clutch is used, the positional relationship between the magnetic poles of the motor and the positional relationship of the opening sensor are deviated from each other and cannot be established. Therefore, by using a clutch mechanism that always returns the motor side and the valve side to fixed positions as the clutch, a throttle actuator having stable characteristics can be obtained regardless of the use of the clutch. others,
It is also possible to learn from the movement of the opening sensor and the movement of the counter electromotive voltage position detector to learn and correct the movement of the opening sensor and the movement of the counter electromotive voltage position detector in real time.

In the system using a microcomputer as a control arithmetic unit, analog information of the opening sensor is taken in as a digital amount via an A / D converter. Although the digital amount of the electrical angle of 60 degrees is calculated, if an A / D converter with a small number of bits is used, the electrical angle of 6 degrees is calculated beforehand.
By synchronizing the digital amount corresponding to 0 degree with an integral multiple of the minimum resolution of the A / D converter, it is possible to operate with a small number of bits and without degrading the performance.

Although the permanent magnet brushless motor has been described, the present invention may be applied to a variable reluctance type brushless motor or to a type in which closed loop operation is performed by detecting the position of the step motor.

Although the throttle valve opening / closing device has been described, it can be applied to other valve opening / closing devices. Further, it can be applied to a control device for a brushless motor other than the valve opening / closing device.

[0070]

As described above, according to the first invention,
The angle of switching the current to the armature is not small, and it is possible to eliminate the need for a highly accurate motor rotation angle detector. In the second invention and the third invention, the output of the brushless motor is prevented from decreasing, the responsiveness is sufficient, and the throttle valve can be quickly moved to the target throttle opening. In the fourth invention, it is possible to switch the current supplied to the stator of the brushless motor without providing a complicated detection device. In the fifth aspect, the entire device can be made simple and inexpensive. In the sixth invention and the seventh invention, it is possible to detect an abnormality in the entire system.

[Brief description of drawings]

FIG. 1 is a diagram showing a throttle actuator and a throttle control unit.

FIG. 2 is a system configuration diagram.

FIG. 3 is a diagram showing details of a control unit.

FIG. 4 is a diagram showing details of a throttle actuator.

FIG. 5 is a diagram showing details of a brushless motor.

FIG. 6 is a diagram showing details of a magnetic pole position detector.

FIG. 7 is a diagram showing an output of a magnetic pole position value detector and a switching state of an FET.

FIG. 8 is a diagram showing details of a driver.

FIG. 9 is a flowchart showing the operation of the throttle control unit.

FIG. 10 is a flowchart showing the operation of the throttle control unit.

FIG. 11 is a flowchart showing the operation of the throttle control unit.

FIG. 12 is a diagram showing a relationship between a throttle opening and a rotation angle of a brushless motor.

FIG. 13 is a diagram showing details of a driver of the second embodiment.

FIG. 14 is a flowchart showing the operation of the throttle control unit of the second embodiment.

FIG. 15 is a diagram showing a rotation angle and a switching state of the brushless motor according to the second embodiment.

FIG. 16 is a flowchart showing the operation of the throttle control unit of the third embodiment.

FIG. 17 is a diagram showing a throttle opening and a switching state of an FET according to a third embodiment.

FIG. 18 is a diagram showing details of a counter electromotive voltage position detector.

FIG. 19 is a diagram showing a throttle opening and a switching state of an FET according to a fourth embodiment.

FIG. 20 is a diagram showing switching states of a D counter and a FET according to the fourth embodiment.

FIG. 21 is a diagram showing details of a magnetic pole position detector of a fifth embodiment.

FIG. 22 is a diagram of the variable reluctance of the sixth embodiment.

[Explanation of symbols]

2 ... Intake passage, 4 ... Throttle valve, 5 ... Throttle actuator, 22 ... Throttle control unit, 24
... magnet rotor, 26 ... reducer, 27 ... magnetic pole position detector,
28 ... Throttle opening sensor, 42 ... Stator winding, 73
… Back electromotive force detector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Sasaki 2520, Takaba, Katsuta-shi, Ibaraki Pref., Automotive Equipment Division, Hitachi, Ltd. Tachi Works Hitachi Research Laboratory

Claims (20)

[Claims] 1. A stator winding, a rotor that rotates by a change in magnetic flux of the stator winding, current control means that controls a current supplied to the stator winding, and intake air to an internal combustion engine. In a throttle actuator of an internal combustion engine having a supply intake passage and a throttle valve arranged in the intake passage to increase and decrease intake air, a deceleration means for decelerating rotation of the rotor and transmitting the decelerated rotation to the throttle valve is provided. A throttle actuator for an internal combustion engine characterized by the above. 2. A stator winding, a rotor that rotates by a change in magnetic flux of the stator winding, current control means for controlling a current supplied to the stator winding, and intake air for an internal combustion engine. In a throttle actuator of an internal combustion engine having a supply intake passage and a throttle valve arranged in the intake passage to increase and decrease intake air, the rotation of the rotor is transmitted to the throttle valve via a gear. A throttle actuator for an internal combustion engine, characterized in that 3. A throttle actuator for an internal combustion engine according to claim 1, wherein the rotor, the deceleration means and the throttle valve are arranged so as to ride on substantially one axis. 4. A throttle actuator for an internal combustion engine according to claim 1, further comprising a return spring for urging the throttle valve in a closing direction, and further using a spiral spring as the return spring. 5. A magnet rotor having magnets arranged around the shaft, a stator winding for giving a magnetic flux to the magnet rotor, an intake passage for supplying intake air to an internal combustion engine, and a rotor for rotating the magnet rotor. In a throttle actuator of an internal combustion engine having a throttle valve for increasing / decreasing intake air, the stator core around which the stator winding is wound is made of a metal continuous in the axial direction. Throttle actuator. 6. The throttle actuator for an internal combustion engine according to claim 5, wherein the stator core is a dust core. 7. The throttle actuator for an internal combustion engine according to claim 6, wherein the axial length of the stator core is substantially the same as the axial length of the magnet rotor. 8. A magnet rotor having magnets arranged around the shaft, a stator winding for giving a magnetic flux to the magnet rotor, an intake passage for supplying intake air to an internal combustion engine, and a rotor for rotating the magnet rotor. In a throttle actuator of an internal combustion engine having a throttle valve for increasing / decreasing intake air, the axial length of the winding portion of the stator core is made shorter than the axial length of the magnet rotor at the facing portion. A throttle actuator for an internal combustion engine characterized by the above. 9. A stator winding, a rotor that rotates due to a change in magnetic flux of the stator winding, current control means that controls a current supplied to the stator winding, and intake air to an internal combustion engine. An intake air amount control device for an internal combustion engine, comprising: a supply intake passage; a throttle valve arranged in the intake passage to increase or decrease intake air; and a throttle control unit for controlling the throttle valve. 2. An intake air amount control device for an internal combustion engine, comprising: a deceleration means for decelerating and transmitting the deceleration to the throttle valve. 10. A stator winding, a rotor that rotates due to a change in magnetic flux of the stator winding, an intake passage that supplies intake air to an internal combustion engine, and an intake air that is disposed in the intake passage. In an intake air amount control device for an internal combustion engine having a throttle valve that increases and decreases and a throttle control unit that controls the throttle valve, a counter electromotive voltage detector that detects a counter electromotive voltage generated by the stator winding. The intake air amount control device for an internal combustion engine, wherein the throttle control unit is configured to control the throttle valve based on an output of the counter electromotive voltage detector. 11. A second rotation state detector for detecting a rotation state of the rotor according to claim 10, wherein the throttle control unit includes the counter electromotive voltage detector or the second rotation state detection. An intake air amount control device for an internal combustion engine, wherein the throttle valve is controlled based on one of the outputs of the engine. 12. The throttle control unit according to claim 10, wherein the throttle valve is controlled based on an output of the reverse voltage detector when the rotor is rotating at a high speed. An intake air amount control device for an internal combustion engine, comprising: 13. A stator winding, a rotor that rotates due to a change in magnetic flux of the stator winding, an intake passage for supplying intake air to an internal combustion engine, and an intake air arranged in the intake passage for supplying intake air. In an intake air amount control device for an internal combustion engine having a throttle valve that increases and decreases and a throttle control unit that supplies a current to the stator winding, a current switching detector that indicates a time point at which a current is supplied to the stator winding. The intake air amount control device for an internal combustion engine, wherein the throttle control unit is configured to supply a current to the stator winding when the output of the current switching detector is present. 14. The intake system according to claim 13, wherein the throttle control unit includes a microcomputer, and the microcomputer is interrupted when the output of the current switching detector is output. Air volume control device. 15. A drive means for generating a rotational force, an intake passage for supplying intake air to an internal combustion engine, a throttle valve arranged in the intake passage for increasing or decreasing intake air, and a throttle for controlling the drive means. In an intake air amount control device for an internal combustion engine having a control unit, a first deceleration means for decelerating the rotation of the drive means and transmitting the deceleration to the throttle valve, and a first deceleration means for detecting that the throttle valve starts to open from a fully closed state. Abnormality is detected based on the output of the detection means, the second detection means for detecting the rotation angle of the drive means in response to the generation of the detection signal of the first detection means, and the output of the second detection means. An intake air amount control device for an internal combustion engine, comprising a first abnormality detecting means. 16. A drive means for generating a rotational force, an intake passage for supplying intake air to an internal combustion engine, a throttle valve that is rotated by the drive means to increase or decrease intake air, and a throttle control for controlling the drive means. In an intake air amount control device for an internal combustion engine having a unit, third detecting means for detecting a rotation angle of the driving means, fourth detecting means for detecting an opening of the throttle valve, and the third detecting means. An intake steam amount control device for an internal combustion engine, comprising: second abnormality detecting means for comparing the output of the detecting means with the output of the fourth detecting means to detect an abnormality. 17. A stator winding, a rotor that rotates due to a change in magnetic flux of the stator winding, an intake passage that supplies intake air to an internal combustion engine, and an intake air that is disposed in the intake passage. In a throttle actuator of an internal combustion engine having a throttle valve that increases and decreases, the number of poles of the rotor is set to P
A throttle actuator for an internal combustion engine, wherein K <P * 3 is satisfied, where K is the number of repetitions of the energization mode to the stator. 18. A stator winding, a rotor that rotates due to a change in magnetic flux of the stator winding, an intake passage for supplying intake air to an internal combustion engine, and an intake air disposed in the intake passage to intake air. A throttle actuator for an internal combustion engine having an increasing / decreasing throttle valve, wherein the rotation angle of the rotor is larger than the rotation angle of the throttle valve. 19. A rotor having a plurality of magnetic poles, a stator having the same number of magnetic poles as the rotor, and a control device for controlling a current supplied to a stator winding of the stator. In a throttle actuator of an internal combustion engine having an intake passage for supplying intake air to an internal combustion engine and a throttle valve rotated by the rotor to increase and decrease intake air, the rotation of the rotor is decelerated and transmitted to the throttle valve. A throttle actuator for an internal combustion engine, comprising a speed reducing means. 20. The throttle actuator for an internal combustion engine according to claim 19, wherein the number of magnetic poles is 4 or less.