Patent Grant
9624840
Technical Field
The present invention relates to an intake air quantity control device for an internal combustion engine, and particularly relates to an intake air quantity control device for an internal combustion engine, which controls an aperture ratio of a throttle valve by a driving unit including a drive motor.
Background Art
In conventional intake air quantity control devices in this family, there is a known intake air quantity control device in which a drive motor is assembled in a throttle body forming an intake air passage of an internal combustion engine, and a gear joined to a motor shaft of the drive motor is linked to a throttle shaft of a throttle valve, and the throttle shaft is rotated at an arbitrary angle by rotating the drive motor, whereby an aperture ratio of the throttle valve provided in the intake air passage is controlled.
In order to improve a vibration-proof capability of a conventional drive motor, an intake air quantity control device for an internal combustion engine, in which a component for damping a vibration (for example, a wave washer or the like) is provided between a bottom surface of the drive motor and a throttle valve, is disclosed (for example, refer to Patent Document 1).
Meanwhile, it has been a problem in recent years that various actuators must be miniaturized in order to reduce space in an engine room, so that there is a conventional system, as a countermeasure for solving the problem, in which an intake air quantity control device can be miniaturized by adopting a flat motor in which the outer diameter of the drive motor is partly flattened.
Japanese Laid-Open Patent Publication No. 2004-153914
As described above, when a flat motor, which the outer diameter of the drive motor is partly flattened, is adopted, an outer diameter of a wave washer, for damping a vibration, which is used in a conventional device described in Patent Document 1, must be shorter than a width of a flat portion of the drive motor. In this case, when the wave washer is fitted to a throttle body, looseness of the wave washer in an outer diameter direction of a cylinder of the drive motor is increased in accordance with a size of an outer diameter of the wave washer and a size of an outer diameter of the cylinder of the drive motor, so that center positions of the drive motor and the wave washer are substantially deviated each other, and there has been a problem in that accuracy of fitting the drive motor to the throttle body is decreased by generating a trouble in which loads are unbalanced or the drive motor overridden on the wave washer. Meanwhile, although the accuracy for fitting the drive motor to the throttle body is increased when the center positions of the drive motor and the wave washer are accurately identical each other, there has been a problem in that a work, by which the center positions of the drive motor and the wave washer become accurately identical, is required, and a workability of fitting the drive motor is decreased.
The present invention has been made to solve above-described problems in conventional intake air quantity control devices for an internal combustion engine, and an object of the invention is to provide an intake air quantity control device for an internal combustion engine having a configuration by which a workability of fitting a drive motor to a throttle body can be improved, and a reliability of a product can be improved.
An intake air quantity control device for an internal combustion engine of the present invention, includes a throttle shaft on which a throttle valve, which is provided in an intake air passage of the internal combustion engine, is arranged so as to be freely rotated and supported; throttle gear that is fixed to the throttle shaft; a pinion gear that is engaged to the throttle gear; a drive motor that includes a motor shaft, to which the pinion gear is fixed, and is freely rotated at an arbitrary angle; throttle body that includes a cylinder-shaped hole having a bottom surface and houses the drive motor in the cylinder shaped hole; and a washer that is arranged between the drive motor and the bottom surface of the cylinder-shaped hole; wherein an aperture ratio of the throttle valve is regulated by rotating the throttle shaft by the drive motor so as to control intake air of the internal combustion engine, and the throttle body includes a position setting means for setting an arrangement position of the washer at the bottom surface of the cylinder-shaped hole.
According to the intake air quantity control device for the internal combustion engine of the present invention, a position setting means for setting an arrangement position of a washer is provided at a bottom surface of a cylinder-shaped hole of a throttle body, so that the washer can be easily and accurately arranged at the bottom surface of the cylinder-shaped hole of the throttle body, and arrangement accuracy of the intake air quantity control device can be improved.
Hereinafter, each of embodiments of the present invention will be explained in reference to drawings. In addition, reference symbols, which are the same as those in each of the drawings, refer to the same or equivalent components or equivalent parts so as to be explained.
The throttle body 2 includes a throttle valve component 4, which supports a throttle valve 3 so as to be opened or closed, a drive motor 5 for driving the throttle valve 3, and a drive chamber 6 for housing a power transmission mechanism composed of a pinion gear, a throttle gear and the like, and is configured in such a way that only a part (a right end portion in
The throttle valve component 4 includes a throttle shaft 9; a first bearing 10 by which one end portion (right end portion in
The throttle shaft 9 is arranged in such a way that its axial line is orthogonal to the intake air passage 1. The throttle shaft 9 is freely rotated and supported around the axial line by the first bearing 10 and the second bearing 11. The first bearing 10 is composed of a ball bearing arranged at one end portion of the throttle shaft 9, and the second bearing 11 is composed of a metal bearing arranged at the other end portion of the throttle shaft 9.
The throttle valve 3 is composed of a circular plate of which cross-sectional area is nearly equal to a cross-sectional area of the intake air passage 1, and is arranged so as to cross the intake air passage 1. The throttle valve 3 is fixed to the throttle shaft 9 by a screw 14, and is rotated with the throttle shaft 9. An aperture ratio of the throttle valve 3 is varied in accordance with a rotational position of the throttle valve 3, whereby an intake air quantity of the internal combustion engine is controlled.
The throttle gear 12 provided at one end portion of the throttle shaft 9 is made of a resin mold, and includes, as described later, a supporting portion 20 having a ring shape, and a fan-shaped portion 21 which is integrally formed at a portion of cuter surface of the supporting portion 20 and has a gear-tooth portion 17 at the outer surface. An inner surface of the supporting portion 20 of the throttle gear 12 is fitted to an outer surface of an insert unit 15 fixed to the throttle shaft 9. Moreover, the throttle gear 12 is fixed, by a nut 16 via the insert unit 15, to one end portion of the throttle shaft 9, and is integrally rotated with the throttle shaft 9 via the insert unit 15 in accordance with the rotation of the throttle shaft 9.
The gear-tooth portion 17 of the throttle gear 12 is configured in such a way that the gear-tooth portion 17 is engaged to a pinion gear 19 provided on a motor shaft 18 of the drive motor 5, and a rotational velocity of the drive motor 5 is reduced and transmitted to the throttle shaft 9.
The above-described throttle gear 12 is composed of the supporting portion 20 having a ring shape, by which the insert unit 15 is fitted to the throttle shaft 9, and the fan-shaped portion 21 having a fan-shaped portion 21. As clearly indicated in
The drive motor 5, in which the outer diameter 32 of the drive motor 5 is partly flattened, as shown in
A wave washer 23 used as a washer is inserted between a bottom surface of the drive motor 5 and a bottom surface of a cylinder-shaped hole 22 used as a cylinder-shaped hole of the throttle body 2. The drive motor 5 is fixed to the throttle body 2 by three attaching screws 24 in a state where the wave washer 23 is compressed.
Moreover, a ring-shaped convex portion 29 having an outer diameter, which is smaller than an inner diameter of the wave washer 23, is formed on the bottom surface of the cylinder-shaped hole 22 of the throttle body 2. Tapered portions 30 are provided at an outer-diameter corner of the ring-shaped convex portion 29 and at an outer-diameter corner of the bottom surface of the cylinder-shaped hole 22 of the throttle body 2. The convex portion. 29 is formed as a position setting means of the present invention.
The rotational angle detector 8 integrated with the cover 7 includes a rotor 25 that is freely rotated and supported by the cover 7, and the rotational angle detector 8 is arranged in such a way that t an axis of the rotor 25 is identical to an axis of the throttle shaft 9 when the cover 7 is fixed to the throttle body 2. Moreover, a lever 26 is fixed to an end portion of the rotor 25, which faces an end portion of the throttle shaft 9. The lever 26 is fitted to a portion of the fan-shaped portion 21 of the throttle gear 12, and follows the throttle shaft 9 so a be rotated.
Moreover, a motor terminal 27 for electrically connecting the drive motor 5 is formed in a protrusion shape on the cover 7. Furthermore, a connector 28, by which the drive motor 5 and the rotational angle detector 8 are electrically linked to an external device, is formed on the cover 7.
As described above, in the intake air quantity control device for the internal combustion engine according to Embodiment 1 of the present invention, a ring-shaped convex portion 29 having an outer diameter, which is smaller than an inner diameter of the wave washer 23 for damping the drive motor 5, is formed on the bottom surface of the cylinder-shaped hole 22 of the throttle body 2, so that the inner diameter of the wave washer 23 is positioned along the outer diameter of the ring-shaped convex portion 29 of the throttle body 2 when the wave washer 23 is arranged on the bottom surface of the cylinder-shaped hole 22 of the throttle body 2, whereby the wave washer 23 can be easily and accurately assembled, and assembly accuracy can be improved.
Moreover, the ring-shaped convex portion 29 having the outer diameter, which is smaller than the inner diameter of the wave washer 23 for damping the drive motor 5, is formed on the bottom surface of the cylinder-shaped hole 22 of the throttle body 2, so that the inner diameter of the wave washer 23 is positioned along the outer diameter of the ring-shaped convex portion 29 of the throttle body 2 when the wave washer 23 is arranged on the bottom surface of the cylinder-shaped hole 22 of the throttle body 2, whereby the wave washer 23 is not substantially deviated as indicated in a conventional device illustrated in
Moreover, the tapered portions 30 are provided at the outer-diameter corner of the ring-shaped convex portion of the throttle body 2 and at the outer-diameter corner of the bottom surface of the cylinder-shaped hole 22 of the throttle body 2, so that the wave washer 23 is suitably set, by its own weight, at an arrangement position only by inserting the wave washer 23 into the cylinder-shaped hole 22 of the throttle body 2. Therefore, a man-hour for a work, such as an accurate positioning work, is not required after the wave washer 23 is inserted, and an assembling capability of the device can be substantially improved.
Moreover, in the intake air quantity control device for the internal combustion engine according to Embodiment 1 of the present invention, the ring-shaped convex portion having the outer diameter, which is smaller than the inner diameter of the wave washer for damping the drive motor, is formed on the bottom surface of the cylinder-shaped hole of the throttle body, so that the inner diameter of the wave washer is positioned along the outer diameter of the ring-shaped convex portion of the throttle body when the wave washer is arranged on the bottom surface of the cylinder-shaped hole of the throttle body, whereby a center axis of the drive motor is easily identical to a center axis of the wave washer. Therefore, a constant generation weight of the wave washer can be expected, and a fear of assembling the drive motor, in a state where the drive motor is positioned over the wave washer, can be eliminate, whereby a reliability of the product can be improved.
Moreover, in the intake air quantity control device for the internal combustion engine according to Embodiment 1 of the present invention, the tapered portions are provided at the outer-diameter corner of the ring-shaped convex portion and at the outer-diameter corner of the bottom surface of the cylinder-shaped hole of the throttle body, so that the wave washer is suitably set, by its own weight, at an arrangement position only by inserting the wave washer into the cylinder-shaped hole of the throttle body. Therefore, a man-hour for a work, such as an accurate positioning work, is not required after the wave washer is inserted, and an assembling capability of the device can be substantially improved.
As described above, each form of the convex portions 31 is not limited to a ring shape indicated in a case of Embodiment 1. Even when the convex portions 31, which are simply formed as indicated in Embodiment 2, are arranged at two positions or at more than two positions, the same effect indicated in Embodiment 1 can be realized.
The intake air quantity control device for the internal combustion engine of the present invention can be applied not only to a control device of an intake air system but also to various actuators using a drive motor and a wave washer (or a plate spring) In addition, in the scope of the present invention, it is possible that each of embodiments is freely combined, or each of embodiments is suitably modified or omitted.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-085414 | Apr 2013 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4340830 | Hoyer-Ellefsen | Jul 1982 | A |
| 5089735 | Sawaguchi | Feb 1992 | A |
| 5334897 | Ineson | Aug 1994 | A |
| 5490487 | Kato | Feb 1996 | A |
| 5945756 | Periyathamby | Aug 1999 | A |
| 6348752 | Erdman | Feb 2002 | B1 |
| 6390062 | Saito et al. | May 2002 | B1 |
| 6486580 | Cenzer | Nov 2002 | B1 |
| 6626143 | Wayama | Sep 2003 | B1 |
| 6880231 | Campbell | Apr 2005 | B2 |
| 6912994 | Ozeki et al. | Jul 2005 | B2 |
| 6945228 | Saito et al. | Sep 2005 | B2 |
| 6966297 | Wayama et al. | Nov 2005 | B2 |
| 6986336 | Tanimura et al. | Jan 2006 | B2 |
| 6997163 | Arai et al. | Feb 2006 | B2 |
| 7051707 | Tanimura et al. | May 2006 | B2 |
| 7213557 | Kondo et al. | May 2007 | B2 |
| RE40382 | Sato | Jun 2008 | E |
| 7832373 | Enomoto | Nov 2010 | B2 |
| 20040170346 | Komeda et al. | Sep 2004 | A1 |
| 20070103010 | Kouzu | May 2007 | A1 |
| 20130063137 | Ikeda et al. | Mar 2013 | A1 |
| 20130106114 | Wang et al. | May 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 2004-153914 | May 2004 | JP |
| 2010-178469 | Aug 2010 | JP |
| 2012-034532 | Feb 2012 | JP |
| Entry |
|---|
| Japanese Office Action dated Dec. 17, 2013 issued in Japanese Application No. 2013-085414. |
| Number | Date | Country | |
|---|---|---|---|
| 20140305404 A1 | Oct 2014 | US |
