JP2003172157A - Electronic control throttle device and operation control method thereof - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide an electronically controlled throttle device capable of reducing a detection error of a throttle sensor and improving detection accuracy of an air flow rate. Further, the present invention provides an operation control method of an electronically controlled throttle device which can ensure responsiveness without impairing reliability in use under a high-voltage power supply environment when the above-mentioned device is used. An electronically controlled throttle device according to the present invention comprises:
The motor 4 is a brushless DC motor in which a stator 42 is arranged on the outer periphery of a rotor 41 and a throttle sensor 5
Is disposed between the throttle valve 2 and the rotor 41. Also, in the operation control method of the electronic control throttle device according to the present invention, in the device, when controlling the voltage applied to the brushless DC motor 4 as a duty waveform input by PWM control, the upper limit value of the duty voltage is limited. use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled throttle device used in an internal combustion engine for automobiles and an operation control method thereof.

[0002]

2. Description of the Related Art An electronically controlled throttle device is conventionally a DC
A 12V or 24VDC battery is used as a power source, the actual opening of the throttle valve is detected by the throttle sensor provided on the throttle shaft, and the necessary drive voltage is calculated by the control circuit based on the deviation from the target opening. A method of applying a duty waveform input to a motor is generally known.

A brush DC motor or a brushless DC motor is used as the motor, and the motor shaft and the throttle shaft are connected via a gear transmission mechanism that gives a reduction ratio to obtain a predetermined rotational torque on the throttle shaft, It is common to open and close the throttle valve. On the other hand, the power supply voltage for automobiles is currently 12V or 24V, but it is expected that the power supply voltage will be increased to 36V DC in the future to adapt to the increase in power consumption in the vehicle, and at the same time, each electronic device mounted in the vehicle. It is required to reduce the power consumption, in other words, the current consumption.

A conventional technique relating to an electronically controlled throttle device and its control method is disclosed in, for example, Japanese Patent Laid-Open No. 5-163.
No. 988 is disclosed.

[0005]

By the way, with a brush D
The electronic control throttle device using the C motor has the following problems. (1) Since the DC motor with a brush switches the energization of the armature coil by sliding the brush on the commutator (so-called rectification), an increase in the potential during rectification under high voltage causes an increase in spark generation, and The wear life of the commutator is reduced. (2) The electronically controlled throttle device has a structure in which the throttle valve is returned to the closing direction by the mechanical load of the spring so that the vehicle does not run out of control even if the motor becomes inoperative. In the motor, there is a frictional resistance due to the sliding between the brush and the commutator, so the spring must put a load to overcome the frictional resistance. Therefore, the current consumption in the electronically controlled throttle device using the brushed DC motor is , This spring load will be higher.

On the other hand, in the electronically controlled throttle device using the brushless DC motor, although the problems shown in the above (1) and (2) cannot occur, the above item 3 is compared with the device using the brush DC motor. Although advantageous to the problems, there were the following problems.

That is, in the electronically controlled throttle device, as described above, the structure in which the throttle valve is returned to the closing direction by the mechanical load of the spring so that the vehicle does not run away even if the motor becomes inoperative. However, in the past, since the throttle sensor is provided at the end of the throttle shaft, the torsional displacement of the shaft caused by the load of the spring causes the throttle sensor to move according to the length of the shaft between the spring and the throttle sensor. An error occurs in the detection result of the sensor.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronically controlled throttle device using a brushless DC motor, in which the throttle sensor has a torsional displacement of the shaft caused by a load of a spring that returns the throttle valve to the closing direction when the motor is inoperative. An object of the present invention is to provide an electronically controlled throttle device that can reduce the detection error and increase the air flow detection accuracy.

Another object of the present invention is to provide an electronically controlled throttle device which, when using the above-mentioned device, is capable of ensuring responsiveness for use in a high voltage power source environment without impairing reliability. It is to provide an operation control method.

[0010]

An electronically controlled throttle device according to the present invention comprises a throttle valve, a throttle sensor, and a control circuit for inputting a predetermined voltage to a motor to control the rotation and holding of the throttle valve. , A brushless D in which the motor is provided with a stator on the outer circumference of the rotor
A C motor is used, and the throttle sensor is arranged between the throttle valve and the rotor.

The operation control method of the electronically controlled throttle device according to the present invention is the device described above, wherein the brushless D
When the voltage applied to the C motor is controlled as a duty waveform input by PWM control, the upper limit value of the duty voltage is limited and used.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of an electronically controlled throttle device according to the present invention.

Reference numeral 1 denotes an air passage, and bodies 1 and 2 finished by aluminum die casting are throttle valves for opening and closing the air passage, 3 is a throttle shaft for supporting the throttle valve 2, and 4 is for driving the throttle valve 2. A brushless DC motor, 5 is a throttle sensor for detecting the opening of the throttle valve 2, 6 is a spring for mechanically closing the throttle valve 2 when the motor is not operating, 7 is an opening value detected by the throttle sensor 5 and an accelerator pedal (Fig. (Not shown) A control for calculating a necessary drive voltage based on a deviation from a target opening signal including a depression amount, and inputting a predetermined duty voltage to the motor 4 by PWM control to control rotation and holding of the throttle valve 2. Reference numeral 8 is a circuit for electrically connecting the control circuit 7, the throttle sensor 5, and the brushless DC motor 4. Is Ness.

Here, in this embodiment, a brushless DC
The motor 4 has a magnet 41b on the motor shaft 41a.
A rotor 41 in which a stator 42 is arranged around the rotor 41.
A brushless motor with a throttle sensor 5
Is provided between the throttle valve 2 and the rotor 41, is provided on the motor shaft 41a, and directly connects the throttle shaft 3 and the motor shaft 41a using a joint 9.

According to this embodiment, the following effects can be obtained by disposing the throttle sensor 5 between the throttle valve 2 and the rotor 41.

That is, the electronically controlled throttle device has a structure in which the throttle valve is returned to the closing direction by the mechanical load of the spring so as to prevent the vehicle from running out of control even if the motor becomes inoperative. In that case, since the throttle sensor is provided at the end of the throttle shaft, the torsional displacement of the shaft caused by the load of the spring causes the detection result of the throttle sensor to change depending on the length of the shaft between the spring and the throttle sensor. It causes an error.

On the other hand, if the throttle sensor 5 is arranged between the throttle valve 2 and the rotor 41 as in the present embodiment, the distance between the spring 6 and the throttle sensor 5 can be made shorter than in the prior art. Throttle sensor 5 due to shaft torsional displacement caused by load 6
It is possible to reduce the detection error of and improve the accuracy of detecting the air flow rate.

When controlling the rotation and holding of the throttle valve 2 based on the target opening signal of the throttle valve 2 according to the operating state, that is, the brushless DC
When controlling the voltage applied to the motor 4 as a duty waveform input by PWM control, by limiting the upper limit value of the duty voltage and using it, a coil or the like can be used even in a high voltage power supply environment such as DC36V. It is possible to secure responsiveness without impairing the reliability of.

FIG. 2 differs from the embodiment shown in FIG. 1 in that the throttle shaft holding the throttle valve 2 and the motor shaft are integrally formed, and the throttle sensor 5 is provided between the throttle valve 2 and the rotor 41. It is positioned and disposed on the throttle / motor integrated shaft 10. With this configuration, the same effect as that in FIG. 1 described above can be obtained.

FIG. 3 shows a control circuit which uses a Hall element for detecting a change in magnetic flux density of the rotor 41 as the throttle sensor 5 in comparison with the embodiment shown in FIG. 2 and controls rotation and holding of the throttle valve 2. 7 is attached to the aluminum die cast body 1 integrally with the throttle sensor 5 by screws or the like.

According to this embodiment, the above-described FIGS. 1 and 2 are used.
In addition to the same effect as the above, the throttle sensor 5 and the control circuit 7
By eliminating the harness between the motor and the motor 4, the commutation delay time of the motor 4 is shortened and the heat deterioration of the hall element is prevented by heat dissipation to the aluminum die casting, and the heat dissipation of the transistor that controls the applied voltage is maintained. be able to.

[0023]

According to the present invention, in an electronically controlled throttle device using a brushless DC motor, the throttle caused by the torsional displacement of the shaft caused by the load of the spring that returns the throttle valve to the closing direction when the motor becomes inoperable. It is possible to reduce the detection error of the sensor and improve the detection accuracy of the air flow rate.

Further, according to the present invention, when the above-mentioned device is used, it is possible to secure the responsiveness to the use under a high voltage power source environment without impairing the reliability.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of an electronically controlled throttle device according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

1 ... Body, 2 ... Throttle valve, 3 ... Throttle shaft, 4 ... Brushless DC motor, 41 ... Rotor, 4
1a ... Motor shaft, 41b ... Magnet, 42 ... Stator, 5 ... Throttle sensor, 6 ... Spring, 7 ...
Control circuit, 8 ... Harness, 9 ... Joint, 10 ... Shaft / motor integrated shaft.

Continued front page    F-term (reference) 3G065 CA34 CA35 DA05 FA06 HA12                       HA22 KA35                 3G301 JA03 JA20 JB02 LA03 LC03                       LC10 ND41 NE17

Claims (5)

[Claims] Claim: What is claimed is: 1. A throttle valve for opening and closing an air flow rate in an intake passage of an internal combustion engine, a throttle sensor for detecting a throttle valve opening, and a motor based on a target opening signal of the throttle valve according to an operating state. And a control circuit for controlling rotation and holding of a throttle valve by inputting a predetermined voltage to the motor, wherein the motor is a brushless DC motor having a stator on the outer circumference of the rotor, and the throttle sensor is An electronically controlled throttle device is disposed between the throttle valve and the rotor. 2. The electronically controlled throttle device according to claim 1, wherein a throttle shaft holding a throttle valve is directly connected to a motor shaft, and a throttle sensor is arranged on the motor shaft. 3. The electronically controlled throttle device according to claim 1, wherein a throttle shaft holding a throttle valve and a motor shaft are integrally formed, and a throttle sensor is arranged on the throttle / motor integrated shaft. 4. The throttle sensor according to claim 1, wherein the throttle sensor is a Hall element that detects a change in magnetic flux density of a rotor provided in the brushless DC motor, and the throttle sensor has a control circuit that controls rotation and holding of the throttle valve. An electronically controlled throttle device attached to the aluminum die-cast body integrally with the. 5. A PWM based on a throttle valve for opening / closing adjusting an air flow rate in an intake passage of an internal combustion engine, a throttle sensor for detecting a throttle valve opening, and a target opening signal of the throttle valve according to an operating state. A brushless D having a control circuit for controlling rotation and holding of a throttle valve by inputting a predetermined duty voltage to the motor under control, the motor being a brushless D having a stator on the outer circumference of the rotor.
A method of controlling the operation of an electronically controlled throttle device in which a C motor is used and the throttle sensor is arranged between the throttle valve and the rotor, wherein a voltage applied to the brushless DC motor is input as a duty waveform input by PWM control. When controlling, Dut
An operation control method for an electronically controlled throttle device, which is used by limiting an upper limit value of y voltage.