JP2012041887A - Electronic throttle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of the coil posture of the opener spring and to enhance the reliability of torque characteristics of the opener spring.SOLUTION: In the opener spring 9, the U-shape hook 13 which abuts on the middle opening controlling member when the valve opening turns to the valve closing side from the middle position is arranged in one side thereof, and the folding back hook 16 providing valve opening force to the spring seat hook 12 is arrange in the other side thereof. The angle θ made by the A-B line and the A-C line is less than 90° when the contact point of "the border part of the folding back hook 16 and the coil 17" and "the gear wall surface 15" is A, the crossing point of the folding back hook 16 and the spring seat hook 12 is B, and the crossing point of the spring seat hook 12 and the gear wall surface 15 is C. Consequently, the load in the boarder part of the folding back hook 16 and the coil 17 is received by the gear wall surface 15 of the contact point A, thereby the coil posture of the opener spring 9 is stabilized, it is possible to avoid the problem that the U-shape hook 13 and the coil 17 interfere with each other, and the reliability of the electronic throttle can be enhanced.

Description

  The present invention relates to an electronic throttle provided with an opener spring (default spring) that returns a throttle valve to an intermediate opening degree from a fully closed position by a restoring force of a torsion coil spring.

The electronic throttle is equipped with an opener spring that returns the throttle valve to an intermediate opening position from the fully closed position in order to enable evacuation travel (limp home) in the event of a failure (for example, Patent Document 1). reference).
The assembled state of the opener spring will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same function thing as [the form for inventing] and [Example] mentioned later.
The electronic throttle includes spring force generating means (return spring 8 + opener spring 9) that returns the stop position of the throttle valve to the intermediate opening by the restoring force of the spring.

  The return spring 8 and the opener spring 9 are torsion coil springs having different winding directions. Here, FIG. 6A shows a case where the return spring 8 and the opener spring 9 are provided by a single wire, and a U-shaped hook 13 is formed at the boundary between the return spring 8 and the opener spring 9. Yes. The U-shaped hook 13 is engaged with a recess on the lower surface of the spring seat hook (U-shaped hook) 12 provided on the valve gear 11 (final gear of the speed reducer) that rotates integrally with the throttle valve, and the return spring 8 The restoring force (valve closing force) is applied to the valve gear 11.

The coil posture of the opener spring 9 (the posture of the coil portion 17) is “the boundary portion between the S-shaped hook 16 ′ locked to the spring seat hook 12 and the coil portion 17 of the opener spring 9” and “the gear wall surface 15 of the valve gear 11”. It depends on the position of contact A.
However, in the prior art, since the degree of freedom of the position of the contact A is large, the coil posture of the opener spring 9 is not stable.
For this reason, as shown in FIG. 6 (b), when the coil posture of the opener spring 9 is poor, the middle portion of the coil portion 17 of the opener spring 9 strongly interferes with the U-shaped hook 13 (the position indicated by the arrow α in the figure). (See)), the torque characteristic (spring characteristic) of the opener spring 9 is deteriorated. As a result, there is a concern that the opener spring 9 cannot exhibit the design performance.

JP 2008-19825 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic throttle that can prevent deterioration of the coil posture of the opener spring and improve the reliability of the torque characteristics (spring characteristics) of the opener spring. On offer.

[Means of Claim 1]
The opener spring of the electronic throttle according to claim 1 includes a folding hook that applies a restoring force in the valve opening direction to the spring seat hook,
The contact between the folding hook and the coil part of the opener spring and the gear wall surface is A,
The contact between the return hook and the spring seat hook is B,
When the intersection of the spring seat hook and the gear wall surface is C,
An angle θ between a straight line passing through the contact A and the contact B and a straight line passing through the contact A and the intersection C is provided to be less than 90 °.

Since the load at the coil end (boundary portion between the folding hook and the coil portion) of the opener spring is received by the gear wall surface of the contact A (angle θ is less than 90 °), the coil posture of the opener spring is stabilized.
Thus, since the deterioration of the coil posture of the opener spring can be prevented, the reliability of the torque characteristic (spring characteristic) of the opener spring can be increased, and as a result, the reliability of the electronic throttle can be increased.

[Means of claim 2]
A straight extension portion {see reference numeral 17a in FIG. 1 (b)} that is straightened and extended is provided at an end portion on the folding hook side of the coil portion of the second aspect. By providing this straight extension portion, an angle θ that is less than 90 ° is set.

[Means of claim 3]
The folding hook of the electronic throttle according to claim 3 is an S-shaped hook having an S-shape (see FIG. 4).

[Means of claim 4]
According to a fourth aspect of the present invention, in the S-shaped hook that forms the folding hook, a part of the curved portion on the side close to the gear wall surface is straightened out of the two curved portions that form the S-shape, so that it is substantially perpendicular to the gear wall surface. An extending straight portion is provided (see FIG. 5).

(A) The side view which showed the spring support structure of the valve gear, (b) It is A view (Example 1). It is sectional drawing which shows the whole structure of an electronic throttle (Example 1). It is explanatory drawing which shows the internal structure of the electronic throttle which removed the gear cover (Example 1). (Example 2) which is the side view which showed the spring support structure of the valve gear. (Example 3) which is the side view which showed the spring support structure of the valve gear. (A) Side view showing the spring support structure of the valve gear showing a state where the coil posture of the opener spring is good, (b) Side view showing the spring support structure of the valve gear showing a state where the coil posture of the opener spring is deteriorated. Yes (conventional example).

[Description of Embodiments] [Mode for carrying out the invention] will be described with reference to the drawings.
The electronic throttle adjusts the amount of intake air drawn into the engine.
A shaft 3 that is rotatably supported by a throttle body 2 that forms an intake passage 1 therein;
A throttle valve 4 which is fixed to the shaft 3 in the intake passage 1 and adjusts the opening of the intake passage 1 according to the rotation position;
An electric actuator 7 including an electric motor 5 that generates rotational torque by energization, and a speed reducer 6 that amplifies the rotational torque of the electric motor 5 and drives the shaft 3;
Spring force generating means (return spring 8 + opener spring 9) for returning the stop position of the throttle valve 4 to the intermediate opening by the restoring force of the spring;
It comprises.

The return spring 8 and the opener spring 9 are torsion coil springs having different winding directions. In each figure, although the return spring 8 and the opener spring 9 are provided with one wire, they are not limited.
A U-shaped hook 13 is formed at a boundary between the return spring 8 and the opener spring 9 to be engaged with a lower surface of a spring seat hook 12 provided in the valve gear 11 (the final gear of the speed reducer 6). In each figure, although the recessed part which U-shaped hook 13 engages is provided in the illustration lower surface of spring seat hook 12, and spring seat hook 12 is U-shaped hook, it is not limited.

The valve gear 11 rotates integrally with the shaft 3,
A coil holding cylinder 14 that is inserted and arranged inside a part of the return spring 8 and the opener spring 9;
A gear wall 15 having a diameter expanded at one end (right end in the figure) of the coil holding cylinder 14;
The spring seat hook 12 is provided on the gear wall surface 15 on the outer peripheral side of the opener spring 9.

The opener spring 9 includes a folding hook 16 that applies a restoring force in the valve opening direction to the spring seat hook 12.
The contact between the boundary portion of the folding hook 16 and the coil portion 17 of the opener spring 9 and the gear wall surface 15 is A,
The contact between the folding hook 16 and the spring seat hook 12 is B,
When the intersection of the spring seat hook 12 and the gear wall surface 15 is C,
An angle θ between a straight line passing through the contact A and the contact B and a straight line passing through the contact A and the intersection C is provided to be less than 90 °.

  Hereinafter, a specific example (example) to which the present invention is applied will be described with reference to the drawings. The embodiments disclose specific examples, and it goes without saying that the present invention is not limited to the embodiments. In addition, in an Example, the same code | symbol is attached | subjected and demonstrated to the same function thing as the said [Mode for carrying out the invention].

[Example 1]
The electronic throttle is attached so as to be interposed in the middle portion of the intake pipe that guides intake air to the engine (internal combustion engine for vehicle travel), and controls the intake amount sucked into the engine.
A throttle body 2 in which an intake passage 1 is formed;
A throttle valve 4 (valve element) that is provided on a shaft 3 that is rotatably supported by the throttle body 2 and adjusts the opening degree of the intake passage 1;
An electric actuator 7 for driving the throttle valve 4 via the shaft 3;
A rotation angle sensor 21 that detects the rotation angle of the shaft 3 (same as the rotation angle of the throttle valve 4) is provided.

The electric actuator 7 is means for rotating the throttle valve 4 via the shaft 3.
An electric motor 5 that generates rotational power when energized;
A speed reducer 6 that amplifies the rotational torque of the electric motor 5;
Spring force generating means for returning the throttle valve 4 to a predetermined intermediate opening;
The electric motor 5 is energized and controlled by an ECU (abbreviation of engine control unit), thereby adjusting the opening of the throttle valve 4, that is, the amount of intake air sucked into the engine.
Below, each said component is demonstrated separately.

The throttle body 2 is manufactured from a metal material or a resin material, and an intake passage 1 is formed inside a substantially cylindrical passage member (bore) formed in the throttle body 2.
A gear cover 22 that can be attached and detached by fastening means such as screws is attached to the outer wall surface of the throttle body 2.
The electric motor 5 is housed in a motor housing chamber formed in the throttle body 2, and the speed reducer 6, spring force generating means, etc. are housed in a space formed between the throttle body 2 and the gear cover 22. .

  The shaft 3 has a cylindrical rod shape made of a metal material, and the rotation center axis of the shaft 3 is orthogonal to the flow path center of the intake passage 1 (bore axis: the central axis of the intake passage 1 along the intake flow direction). It arrange | positions in a direction and is rotatably supported with respect to the throttle body 2 via the bearing 23 (rolling bearing or a sliding bearing).

The throttle valve 4 is a butterfly type rotary valve having a substantially disc shape formed of a metal material or a resin material.
The throttle valve 4 is assembled into the intake passage 1 after the shaft 3 is assembled to the throttle body 2, and is fixed to the shaft 3 by coupling means 24 such as screws and caulking. As a result, the throttle valve 4 rotates integrally with the shaft 3 to vary the opening of the intake passage 1 formed in the throttle body 2 and adjust the intake amount sucked into the engine.

  The electric motor 5 is a well-known DC motor that changes the rotation direction when the energization direction is switched and generates a rotational torque in accordance with the energization amount. The electric motor 5 is assembled in a motor housing chamber formed in the throttle body 2. ing.

  The reduction gear 6 is a gear-type reduction gear that reduces the rotational torque generated by the electric motor 5 by a combination of a plurality of gears and transmits it to the throttle valve 4, and a motor gear 25 (pinion gear) that rotates together with the electric motor 5. The intermediate gear 26 is rotationally driven by the motor gear 25, and the valve gear 11 (final gear) is rotationally driven by the intermediate gear 26. The valve gear 11 rotates integrally with the shaft 3.

The motor gear 25 is a small-diameter external gear fixed to the output shaft of the electric motor 5.
The intermediate gear 26 is a double gear in which a large-diameter gear 26 a and a small-diameter gear 26 b are provided concentrically and is rotatably supported by a support shaft 27 supported by the throttle body 2 and the gear cover 22. The large-diameter gear 26a always meshes with the motor gear 25, and the small-diameter gear 26b always meshes with the valve gear 11.

  The valve gear 11 is a large-diameter external gear fixed to the shaft 3 by a caulking portion 11 a at the end of the shaft 3, and the meshing teeth are provided only in the range accompanying the rotation of the throttle valve 4. Specifically, the valve gear 11 is provided by, for example, a resin material, and inside the valve gear 11, in addition to the coupling fitting 28 that is coupled to the shaft 3 by caulking, a magnetic flux generation unit 31 in the rotation angle sensor 21. Is insert molded.

The spring force generation means holds the opening of the throttle valve 4 at an intermediate position between the fully closed position and the fully open position when the current supply to the electric motor 5 is interrupted, thereby enabling the vehicle to retreat. This is a combination of a return spring 8 that applies a biasing force (valve closing force) in the direction of closing the throttle valve 4 and an opener spring 9 that applies a biasing force (valve opening force) in the direction of opening the throttle valve 4. .
Details of the return spring 8 and the opener spring 9 will be described later.

The rotation angle sensor 21 is a throttle position sensor that detects the opening degree of the throttle valve 4 by detecting the rotation angle of the shaft 3, and outputs an opening degree signal corresponding to the angle of the shaft 3 (opening degree of the throttle valve 4). Output to ECU.
Specifically, the rotation angle sensor 21 is a magnetic sensor that detects the relative rotation of two members in a non-contact manner, and includes a magnetic flux generator 31 that has a substantially cylindrical shape that rotates integrally with the shaft 3, and a gear cover 22 (fixed). The magnetic detection unit 32 is attached to the member and disposed in a non-contact manner with respect to the magnetic flux generation unit 31, and a voltage signal (an output signal of the Hall IC) generated by the magnetic detection unit 32 is given to the ECU.
The ECU is a well-known electronic control device equipped with a microcomputer, and the actual opening degree of the throttle valve 4 detected by the rotation angle sensor 21 becomes a target opening degree set by the accelerator pedal opening degree or the like. Thus, the electric motor 5 is provided to be controlled.

Next, the return spring 8 and the opener spring 9 will be described.
As described above, the electronic throttle includes the return spring 8 and the opener spring 9 that return the stop position of the throttle valve 4 to the intermediate opening by the restoring force of the spring.
The return spring 8 and the opener spring 9 are torsion coil springs having different winding directions. In the embodiment, the return spring 8 and the opener spring 9 are provided by a single wire.

A U-shaped hook 13 protruding in the radial direction is formed at the boundary between the return spring 8 and the opener spring 9.
The U-shaped hook 13 is provided so as not to rotate from a predetermined position (a position at which the intermediate opening is set) to the valve closing side by an intermediate opening adjusting member 33 provided in the throttle body 2. That is, the U-shaped hook 13 is provided so as to rotate only to the valve opening side with respect to the contact position of the intermediate opening degree adjusting member 33.

Here, the configuration of the valve gear 11 related to the return spring 8 and the opener spring 9 will be described.
The valve gear 11 is integrally provided with a coil holding cylinder 14 inserted and arranged on the right side of the return spring 8 in FIG. 1A and the opener spring 9.
The meshing teeth of the valve gear 11 are the outer peripheral edge of the gear wall 15 whose diameter is enlarged at the right end of FIG. 1A of the coil holding cylinder 14 (as described above, the meshing teeth are only in the range accompanying the rotation of the throttle valve 4. Provided).

Further, the valve gear 11 is provided with a spring seat hook 12 that receives the restoring force of the return spring 8 and the opener spring 9.
The spring seat hook 12 is provided on the gear wall surface 15 on the outer peripheral side of the opener spring 9. Specifically, the spring seat hook 12 is a protrusion that extends vertically from the gear wall surface 15 to the left side of FIG. 1A, and is provided integrally with the valve gear 11. The spring seat hook 12 of this embodiment employs a U-shaped hook in which a concave portion with which the U-shaped hook 13 is engaged is formed on the lower surface in the drawing.

Next, the assembled state of the return spring 8 will be described.
An I-shaped hook 34 that is engaged with the throttle body 2 is provided at the left end of the return spring 8 in FIG.
Further, at the right end of FIG. 1A of the return spring 8, a U is applied to the spring seat hook 12 by being engaged with a recess in the lower surface of the spring seat hook 12 and restoring force (rotation force in the valve closing direction). A character hook 13 is provided.
Then, when the opening degree of the throttle valve 4 is rotated to the valve opening side from the intermediate position (the opening degree set by the intermediate opening degree adjusting member 33), the U-shaped hook 13 is separated from the intermediate opening degree adjusting member 33. Therefore, the U-shaped hook 13 presses the spring seat hook 12 in the valve closing direction by the restoring force of the return spring 8 to return the throttle valve 4 to the intermediate opening.

Next, the assembled state of the opener spring 9 will be described.
A U-shaped hook 13 is provided at the left end of the opener spring 9 in FIG. 1A to be engaged with the recess on the lower surface of the spring seat hook 12 as described above.
Further, the opener spring 9 is engaged with the upper surface of the spring seat hook 12 at the right end of FIG. 1A to apply the restoring force (rotation force in the valve opening direction) of the opener spring 9 to the spring seat hook 12. A folding hook 16 is provided.
Then, when the opening degree of the throttle valve 4 is rotated from the intermediate position to the valve closing side, the U-shaped hook 13 comes into contact with the intermediate opening degree adjusting member 33, and the return hook 16 is restored by the restoring force of the opener spring 9. Presses the spring seat hook 12 in the valve opening direction to return the throttle valve 4 to the intermediate opening.

The folding hook 16 abuts on the gear wall surface 15 of the valve gear 11 at the boundary between the coil portion 17 and the folding hook 16 in the opener spring 9. This contact point (the contact point between the opener spring 9 and the gear wall surface 15) is A.
Further, the folding hook 16 contacts the upper surface of the spring seat hook 12 in the drawing. This contact point (the contact point between the folding hook 16 and the spring seat hook 12) is designated as B.
Furthermore, the intersection of the spring seat hook 12 and the gear wall surface 15 (the base portion of the spring seat hook 12) is C.

In the electronic throttle of this embodiment, as shown in FIG. 1A, an angle θ between a straight line passing through the contact A and the contact B and a straight line passing through the contact A and the intersection C is less than 90 °. Is provided.
Specifically, as shown in FIG. 1B, a straight extension portion 17a that is straightened and extended is provided at the end portion on the folding hook 16 side of the coil portion 17 of this embodiment. By providing this straight extension portion 17a at the end of the coil portion 17, an angle θ that is less than 90 ° is set.

Since the electronic throttle of this embodiment employs the above-described configuration, the load at the boundary portion between the folding hook 16 and the coil portion 17 is received by the gear wall surface 15 of the contact A (angle θ is less than 90 °). The coil posture of the spring 9 is stabilized.
As a result, it is possible to avoid the problem that the U-shaped hook 13 and the coil portion 17 which are caused by the deterioration of the coil posture strongly interfere with each other, and the reliability of the torque characteristic (spring characteristic) of the opener spring 9 is improved. The reliability of the electronic throttle can be increased.

  As shown in FIG. 1A, the folding hook 16 of the first embodiment is substantially U-shaped when the opener spring 9 is viewed from the side, and the spring hook 12 and the folding hook 16 are connected to each other. Although the contact portion is a cut portion of the opener spring 9, it is not limited as shown in Examples 2 and 3 described later.

[Example 2]
A second embodiment will be described with reference to FIG. In the following embodiments, the same reference numerals as those in the first embodiment denote the same functional objects.
The first embodiment has shown an example in which the folding hook 16 has a substantially U-shape when the opener spring 9 is viewed from the side surface direction.
On the other hand, in the second embodiment, when the opener spring 9 is viewed from the side, the folding hook 16 is provided as an S-shaped hook having an S-shape.

Even if the folding hook 16 is formed as an S-shaped hook as in the second embodiment, the same effect as in the first embodiment can be obtained by setting the contact A and the contact B so that the angle θ is less than 90 °. Obtainable.
In the second embodiment, the contact portion between the spring seat hook 12 and the folding hook 16 becomes a bent portion in the S-shaped hook. For this reason, the opening force of the opener spring 9 can be applied from the folding hook 16 to the spring seat hook 12 without causing the cut portion of the opener spring 9 to damage the spring seat hook 12.

[Example 3]
A third embodiment will be described with reference to FIG.
In the third embodiment, like the second embodiment, the folding hook 16 is provided as an S-shaped hook, and a straight portion 35 is provided in a part of the S-shaped hook.
Specifically, as shown in FIG. 5, the folding hook (S-shaped hook) 16 straightens a part of the curved portion closer to the gear wall surface 15 (right side in the drawing) out of the two curved portions forming the S shape. Thus, a straight portion 35 extending in a substantially vertical direction with respect to the gear wall surface 15 is provided.
Even if it provides in this way, the same effect as Example 2 can be acquired.

  Further, although different from FIG. 5, by providing a straight portion 35 similar to that of the third embodiment to the S-shaped hook in the prior art, the coil posture of the opener spring 9 can be stabilized without increasing the size of the folding hook 16. It can be made.

  In the above embodiment, the return spring 8 and the opener spring 9 are provided with one wire, but the return spring 8 and the opener spring 9 may be provided with different wires. In addition, when the return spring 8 and the opener spring 9 are provided with different wires, both may be combined or may be used without being combined.

  In the above-described embodiment, an example in which a U-shaped hook is used as an example of the spring seat hook 12 has been described. However, the shape of the spring seat hook 12 is not limited, such as using an L-shaped hook.

  As an example of the opener spring 9, an opener spring 9 in which the center of the coil is eccentrically provided in a free state (no load state) and the center of the coil is substantially concentric when assembled may be used.

4 Throttle valve 9 Opener spring 11 Valve gear 12 Spring seat hook 15 Gear wall surface 16 Return hook 17 Opener spring coil portion 17a Straight extension portion 35 Straight portion

Claims (4)

A spring seat hook (12) provided on a valve gear (11) for driving the throttle valve (4) is twisted to apply a restoring force of the coil spring so that the throttle valve (4) has a predetermined intermediate opening from the fully closed position. In electronic throttle with opener spring (9) to return to
The opener spring (9) includes a folding hook (16) for applying a restoring force in the valve opening direction to the spring seat hook (12),
The contact between the folding hook (16) and the boundary portion of the coil portion (17) of the opener spring (9) and the gear wall surface (15) is A,
The contact between the folding hook (16) and the spring seat hook (12) is B,
When the intersection of the spring seat hook (12) and the gear wall surface (15) is C,
An electronic throttle, wherein an angle θ between a straight line passing through the contact A and the contact B and a straight line passing through the contact A and the intersection C is less than 90 °. The electronic throttle according to claim 1, wherein
At the end of the coil portion (17) on the folding hook (16) side, a straight and extended straight extension portion (17a) is provided, and this straight extension portion (17a) is provided. The electronic throttle is characterized in that the angle θ is set to be less than 90 °. The electronic throttle according to claim 2,
2. The electronic throttle according to claim 1, wherein the folding hook (16) is an S-shaped hook having an S-shape. The electronic throttle according to claim 3,
Of the two curved parts forming the S-shape with the S-shaped hooks forming the folding hook (16), a part of the curved part on the side close to the gear wall surface (15) is straightened to the gear wall surface (15). An electronic throttle comprising a straight portion (35) extending in a substantially vertical direction.

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