JP4215783B2 - Throttle valve control device for internal combustion engine - Google Patents

Description

  The present invention relates to a throttle valve control device that controls an intake air flow rate of an internal combustion engine.

  An electronically controlled throttle device that controls opening / closing of a throttle valve of an internal combustion engine by an electric actuator (for example, a DC motor, a stepping motor, a torque motor, or a brushless motor) has been put into practical use.

  The electronically controlled throttle device controls an optimum throttle valve angle (throttle valve opening) according to the engine state based on an accelerator pedal opening signal and a traction control signal. Therefore, a sensor for detecting the angle of the throttle valve, a so-called throttle sensor (sometimes referred to as an opening meter or a throttle position sensor) is attached to the throttle body.

  A potentiometer system is generally used for the throttle sensor, and a potential difference signal (sensor detection signal) corresponding to the throttle valve opening is obtained when a brush (slider) that rotates with the throttle valve shaft slides on a resistor. (See, for example, JP-A-7-343878 and JP-A-9-32588).

JP-A-7-343878 JP-A-9-32588

  This type of throttle sensor conventionally used has a brush that contacts and slides on a variable resistor and a conductor formed on a resistor substrate. For this reason, the lifetime of a sensor is short and there are many failures. Although sensor failure detection and mutual backup are performed using a double sensor system, this is not a fundamental solution.

  Further, the conventional automobile has a high possibility of such a failure, and the control parameters are controlled by the output of a sensor having a short life, so that the operation control accuracy of the internal combustion engine is poor.

  Japanese Patent No. 2845884 is known as a means for detecting the opening degree of the throttle valve in a non-contact manner, but it has not been put into practical use because it has no device for practical use as a throttle control valve device.

  An object of the present invention is to provide a throttle valve control device provided with a throttle sensor that has few failures and a long life.

  In particular, several ideas for compactly mounting a non-contact sensor as a part of the throttle control device are proposed.

  We also propose a device to remove magnetic noise and adverse effects on magnetic properties.

  Another object is to improve the operation control accuracy of the internal combustion engine by improving the throttle sensor which is one of the control parameters of the control parameters of the internal combustion engine.

In order to achieve the above object, the present invention proposes the following throttle valve control device.
(1) A throttle valve shaft, a final gear fixed to the throttle valve shaft and transmitting the driving force of the motor to the throttle valve shaft, a throttle body that supports the throttle valve shaft, and rotation of the throttle valve shaft A throttle sensor that detects an angle; and a cover that is attached to the throttle body and covers the final gear. The throttle sensor is a magnetic type that includes a magnet and a Hall element that detects a change in magnetic flux of the magnet. The throttle valve control of the internal combustion engine, wherein the magnet and the hall element are disposed between a surface of the gear fixed to the throttle valve shaft on the side facing the throttle body and an inner surface of the cover. apparatus.

In particular,
(2) The throttle valve control device for an internal combustion engine, wherein the magnet is attached to the throttle valve shaft, and the hall element is attached to the cover.
(3) A throttle valve control device for an internal combustion engine, wherein the output of the Hall element is a function of the opening of the throttle valve.
(4) A throttle valve control device for an internal combustion engine in which a command value of the motor is adjusted by an electric signal output from the throttle sensor.
(5) The gear includes a metal plate fixed to the throttle valve shaft and a synthetic resin portion that forms teeth. The synthetic resin portion is formed by insert-molding the metal plate. And a throttle valve control device for an internal combustion engine formed integrally with the engine.
(6) The rotation shaft of the motor and the throttle valve shaft are arranged in parallel, and the rotation of the rotation shaft of the motor is transmitted to the throttle valve shaft via a reduction gear. A throttle valve control device for an internal combustion engine in which a support shaft of an intermediate gear located in the middle of a torque transmission path between the throttle valve shaft and a magnetic material is formed.
(7) A throttle valve control device for an internal combustion engine, wherein the cover is provided with the Hall element and a signal processing circuit for converting the output of the Hall element into a predetermined electric signal.
(8) A throttle valve control device for an internal combustion engine, in which a spring is mounted around the throttle valve shaft to hold the magnet in a predetermined opening position when the motor is de-energized.
(9) The throttle valve control device for an internal combustion engine, wherein the Hall element is composed of two elements arranged under the magnetic influence of the magnet and is configured to back up each other.

  According to the present invention, the non-contact type sensor can be compactly assembled to the throttle body.

  According to another invention, a non-contact type throttle sensor can be compactly arranged between the cover of the throttle body and the gear.

  In another invention, the electromagnetic non-contact type throttle sensor can be assembled to the throttle body with a configuration that is hardly affected by the electromagnetic noise of the motor.

  The control parameters of the engine can be adjusted with the throttle opening signal with little secular change, so an automobile with good control accuracy was obtained.

  An embodiment according to the present invention will be described below with reference to the drawings.

As shown in FIG. 1, an electronically controlled throttle valve device (throttle valve device) includes a throttle body (hereinafter also simply referred to as a body) 1, a throttle valve 4 and a motor that drives a throttle valve 4 (throttle valve drive). Device; electric actuator) 22, reduction gear mechanism 100, opening angle (opening) of throttle valve 4, that is, sensor (throttle sensor) 80 for measuring the rotation angle of throttle valve shaft 3, throttle valve shaft 3, motor 22, The cover 16 that protects the reduction gear mechanism 100 is configured as a main element.

  The body 1 is formed by integrally forming a storage portion (intake bore) 2 of the throttle valve 4 and a storage portion (motor housing) 1c of the motor 22.

  The throttle valve 4 is attached to the throttle valve 4 shaft 3 by screws 5, and the shaft 3 is supported by bearings 6 and 26 provided on the body 1.

  In this embodiment, the bearing 6 is a ball bearing and the bearing 26 is a cap-shaped plain bearing. The reason and details will be described later. The ball bearing 6 is attached to the bearing boss 1 a via the seal ring 8. Further, the inner ring 6a of the ball bearing 6 is press-fitted into the outer periphery of the throttle valve shaft 3, and the outer ring 6b is intermediately fitted (stop fit) to the inner circumference of the bearing boss 1a.

  Only one end of the throttle valve shaft 3 protrudes from the side wall of the body 1. A spring 10, a lever 9, a spring 11, and a final gear (driven gear) 12 of the reduction gear mechanism 100, which will be described later, are mounted on one end of the throttle valve shaft that protrudes outside the side wall.

  Throttle valve-related parts (hereinafter referred to as the throttle valve mechanism) such as the throttle valve shaft 3, the reduction gear mechanism 100, and the motor 22 are accommodated in an accommodating portion (case) 1d formed on the side wall of the body 1, and the accommodating portion 1d is covered with a synthetic resin cover 16. The plain bearing 26 is attached by press fitting.

  That is, the throttle valve mechanism is disposed so as to be protected by one cover 16, and the opening (motor mounting opening) 1c 'of the motor housing 1c is positioned so as to face the housing portion 1d. The motor 22 is accommodated in the housing through the opening, and the end bracket 22a of the motor is fixed around the opening 1c ′ by screws 37 (see FIGS. 3 and 4).

  The motor terminal 23 provided on the end bracket 22a is located near one side of the side wall of the housing portion 1d, is disposed toward the cover 16 side, and is connected to the relay terminal 24a provided on the cover 16 side via the relay connector 33. Has been. The relay connector 33 may have various forms. In this embodiment, a sleeve made of a conductive material is used as the relay connector 33, and slits 34 and 35 are provided at both ends thereof that are shifted by 90 degrees, and the relay terminal 24a and the motor terminal 23 are inserted into the slits. . These terminals 24a and 23 are also displaced by 90 degrees in accordance with the directions of the slits 34 and 35.

  The motor 22 is driven in accordance with an accelerator signal, a traction control signal, a constant speed travel signal, and an idle speed control signal related to the depression amount of the accelerator pedal, and the power of the motor 22 is reduced to the speed reduction gear mechanism 100 (motor pinion 21, intermediate gear 20, final). It is transmitted to the throttle valve shaft 3 via the step gear 12). The pinion 21 is attached to the motor shaft 27, and the intermediate gear 20 is freely fitted to the conductive shaft 19 fixed to the throttle body 1. Of the intermediate gear 20, the larger diameter gear 20 a meshes with the pinion 21, and the smaller diameter gear 20 b meshes with the gear 12.

  The last gear 12 is a sector gear as shown in FIGS.

  The relationship between the gear 12 and the lever 9 will be described. As shown in FIG. 3, the gear 12 has a hole 12h through which one end of the throttle valve shaft 3 passes, and the hole 12h has a shape engageable with one end of the throttle valve shaft 3a ′ (having at least two planes). Yes, it rotates together with the throttle valve shaft.

The lever 9 is freely fitted on the outer periphery (circumferential surface) of the throttle valve shaft 3, but is engaged with the gear 12 via the spring 11. For example, the protrusion indicated by reference numeral 12 f in FIG. 4 engages with a protrusion (not shown) of the lever 9. The protrusion 12 f is formed inside the gear 12.

  A spring 10 is a return spring of the throttle valve, and has one end locked to a spring locking portion (not shown) provided on the body 1 and the other end locked to a lever 9.

  The spring 10 applies a return force to the throttle valve shaft via the lever 9 and the gear 12, and further, in cooperation with the spring 11 and the lever 9, constitutes a so-called default opening setting mechanism that is already known.

The default opening setting mechanism is for holding the initial opening of the throttle valve 4 at a predetermined opening larger than the fully closed position when the engine key is off (in other words, when the electric actuator 22 is not energized).

  From the default opening position to the fully open control position, the throttle valve opening is determined by the balance between the torque of the motor 22 and the closing force of the spring (return spring) 10.

  When the throttle valve opening is controlled to be smaller than the default opening, the movement of the lever 9 is restricted by a default opening stopper (not shown), and only the gear 12 and the throttle valve shaft 3 are resisted against the force of the spring 11. This is done by rotating in the fully closed direction.

  The fully closed position is determined by contacting a movable stopper 12d provided on one side of the sector gear 12 with a fully closed stopper (not shown) that defines the mechanical fully closed position of the throttle valve.

  As for the material of the gear 12 in this embodiment, the central part is a metal plate 12a, and the part 12b forming the teeth and the remaining part are integrally formed of synthetic resin (reinforced plastic).

  In this case, the metal plate 12a is insert-molded in the resin portion of the gear 12.

  The gear 12 side end of the magnet 82 faces the resin portion of the gear.

  For this reason, the magnetic flux of the magnet 82 can be prevented from leaking to the gear 12.

The metal plate 12a at the center of the gear 12 is pressed against the throttle body 1a by the magnet holder 81. However, since the magnet holder 81 itself is a resin material, there is no leakage of magnetic flux even if it contacts the metal plate 12a.

  A movable-side stopper 12d formed on one of the cut end faces of the gear 12 is integrally connected to the metal plate 12a.

  The movable side stopper 12d is made of metal in order to achieve wear resistance and shock resistance. That is, the mechanical fully closed position of the throttle valve serves as a control reference point, and the stopper element 12d hits the fixed side fully closed stopper 25 once every time the operation starts or ends. For this reason, the movable stopper 12d is made of metal so that it can withstand a relatively high collision frequency.

  12 i is a guide for engaging the gear 12 with the lever 9.

  A resin magnet holder 81 is press-fitted and fixed to the tip of the throttle valve shaft 3, and a magnet 82 is integrally attached to the magnet holder 81 by molding.

  The end of the magnet holder 81 presses the end surface of the gear 12 against the stepped portion 3d side of the throttle shaft 3 and also serves to prevent the gear 12 from coming off.

  A circuit board 84 of the throttle sensor 80 is fixed by a welding pin 86 at a position facing the end of the throttle shaft 3 on the inner surface of the cover 16.

  A pair of half-moon shaped stators 83 are fixed to the circuit board 84 so as to face each other with a predetermined gap 87 so as to surround the magnet 82. Reference numeral 85 denotes a guide for the stator 83 provided integrally with the circuit board 84.

  A Hall element 86 is attached to an interval 87 portion between the pair of half-moon shaped stators 83.

The three terminals of the Hall element 86 are mechanically held on the circuit board 84 and are connected to a signal processing circuit such as an amplifier or an analog / digital converter (not shown) disposed on the circuit board 84.

The signal processing circuit disposed on the circuit board 84 is connected to the conductor 24 integrally molded with the cover 16 and via the electrical terminals 40 (connected to the conductor 24) of the connector 16b integrally molded with the cover. Signals can be sent to external devices.

  When the throttle valve shaft 3 rotates and the magnet 82 rotates, the hall element 86 detects a change in the magnetic field and generates a hall voltage.

  This voltage is amplified by an amplifier or converted into a signal (including amplification) by an analog / digital converter and sent to an external circuit via the conductor 24 and the terminal 40.

  An automobile engine control unit (not shown) includes a coupler and a signal line connected to the connector 16b, and a signal from the terminal 40 is input to the control unit.

  Based on the throttle opening and the vehicle speed detected by the change in the magnetic field as the magnetic physical quantity of the magnet 82, the control unit corrects the control parameters such as fuel and throttle valve opening, and the shift point of the auto transmission. Take control.

  When the motor 12 is de-energized, the spring 11 urges the gear 12 in the opening direction of the gear 12 and forcibly opens the sensor magnet 82 to a predetermined opening position.

Thus, the automobile equipped with the throttle control device of this embodiment receives the magnetic signal of the magnet attached to the shaft end of the throttle valve and receives the electrical signal output from the hall element 86 in relation to the opening of the throttle valve. Changes in the engine control parameters are adjusted.

  Since the sensor is a non-contact type, the opening signal of the throttle valve 4 as a change in the electrical signal output from the Hall element 86 has few elements that cause a secular change, so that the control parameters of the internal combustion engine can be adjusted accurately over a long period of time. Yes.

  The principle of the sensor will be described with reference to FIG.

  A magnet 82 as a rotor of the throttle sensor 80 is fixed to the magnet holder 81 with a pair of arc-shaped magnets having different polarities facing each other.

  When the magnet holder 81 is fixed to the throttle valve 3 and the throttle valve shaft 3 is rotated, the joint surface of both magnets rotates relative to the Hall element. FIG. 7 shows changes in the magnetic field lines in this state.

  A pair of Hall elements 86 installed on the joint surface portion of the magnetic pole outputs a signal that is a function of the rotation angle in response to the change in the magnetic field lines accompanying the change in the rotation angle of the throttle valve shaft 3.

  Since the gear 12 is made of synthetic resin, the magnetic field generated by the magnet 82 is not adversely affected by the gear 12.

  In the embodiment, the central portion fitted to the throttle valve shaft 3 is made of metal, but if all are formed of a synthetic resin material, the magnetic adverse effect is further reduced.

Even if the shape of the gear 12 is an irregular shape such as a fan shape, the magnetic field is not biased, so that the sensitive characteristic of the Hall element 86 can be obtained uniformly regardless of the rotation angle of the throttle shaft.

  As shown in FIG. 5, the Hall element 86 is attached outside the area of the arc S drawn around the rotation center of the motor with the dimension between the rotation axis center of the motor and the throttle rotation center as the radius.

  As a result, the Hall element 86 is not easily affected by the electromagnetic effect due to the change in the drive current of the motor, and the detection accuracy of the Hall element 86 is not easily disturbed.

  Since the stator 83 is attached to the circuit board 84 and fixed to the inner surface of the cover 16, the assembly work of the stator 83 is easy.

  Note that the stator can be directly fixed to the cover 16.

  In this case, the control circuit is shifted and fixed to the side of the stator, but there is an advantage that the axial dimension can be shortened.

  Since the rotation support shaft 19 of the intermediate gear 20 positioned between the motor 22 and the magnetic non-contact sensor 80 is made of a magnetic material, the rotation support shaft 19 shields electromagnetic influences due to changes in the drive current of the motor 22. The Hall element 86 is hardly affected by the electromagnetic influence of the motor 22 and the detection accuracy of the Hall element 86 is hardly disturbed.

  As shown in FIG. 6, the throttle valve shaft 3, the springs 10 and 11, the lever 9, the final gear 12, the magnet holder 81, and the magnet 82 can be assembled to the throttle body 1 as subassemblies, so that the assembling work is easy.

1 is a cross-sectional view of a throttle valve control device according to an embodiment of the present invention. FIG. 5 is another cross-sectional view of a throttle valve control device according to an embodiment of the present invention. 1 is an exploded perspective view of a throttle valve control device according to one embodiment of the present invention. The exploded perspective view seen from another angle of the throttle valve control device which becomes one example of the present invention. The figure for demonstrating the characteristic of the structure of an Example. The drawing which shows a throttle valve shaft assembly. (A), (b) is drawing for demonstrating the movement of a magnet and the positional relationship of a Hall element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Throttle body, 2 ... Bore, 3 ... Throttle valve shaft, 4 ... Throttle valve, 9 ... Lever, 10, 11 ... Spring, 12 ... Final gear, 16 ... Cover, 22 ... Motor, 80 ... (Non-contact type) ) Throttle sensor, 81... Magnet holder, 82 .. magnet, 83 .. stator, 84 .. circuit board, 86.

Claims (8)

A throttle valve shaft,
A final gear fixed to the throttle valve shaft and transmitting the driving force of the motor to the throttle valve shaft;
A throttle body that supports the throttle valve shaft;
A throttle sensor for detecting a rotation angle of the throttle valve shaft;
A cover attached to the throttle body and covering the final gear;
The throttle sensor is a magnetic type including a magnet and a Hall element that detects a change in magnetic flux of the magnet,
The magnet and the hall element are disposed between a surface of the final gear fixed to the throttle valve shaft on the side facing the throttle body and an inner surface of the cover ,
The cover is integrally formed with a connection terminal protruding toward the motor,
An output gear attached to the output shaft of the motor is located between the connection terminal and the throttle sensor ,
Furthermore, the rotating shaft of the motor and the throttle valve shaft are arranged in parallel,
The rotation of the rotation shaft of the motor is transmitted to the throttle valve shaft through a reduction gear including the output gear and a final gear,
A throttle valve control device for an internal combustion engine, wherein a support shaft of an intermediate gear located in the middle of a torque transmission path between the output gear and the final gear is formed of a magnetic material . In claim 1,
The magnet is attached to the throttle valve shaft;
The hall element is a throttle valve control device for an internal combustion engine attached to the cover. In claim 1,
A throttle valve control device for an internal combustion engine, wherein the output of the Hall element is a function of the opening of the throttle valve. In claim 1,
A throttle valve control device for an internal combustion engine, wherein a command value of the motor is adjusted by an electric signal output from the throttle sensor. In claim 1,
The final gear is composed of a metal plate fixed to the throttle valve shaft, and a synthetic resin portion that forms teeth,
The throttle valve control device for an internal combustion engine, wherein the synthetic resin portion is formed integrally with the metal plate by insert molding of the metal plate. What is claimed in claim 1
A throttle valve control device for an internal combustion engine, wherein the cover is provided with the Hall element and a signal processing circuit for converting the output of the Hall element into a predetermined electric signal. In claim 1,
A throttle valve control device for an internal combustion engine, wherein a spring for holding the magnet at a predetermined opening position when the motor is de-energized is mounted around the throttle valve shaft. In claim 1,
2. A throttle valve control device for an internal combustion engine, wherein the Hall element is composed of two elements arranged under the magnetic influence of the magnet and is configured to back up each other.

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