JP2005036761A - Electronic throttle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively suppress the vibration of a motor by increasing a heat radiating performance upon heating of the motor. <P>SOLUTION: This electronic throttle device 1 comprises a throttle body 2 having a bore 5 and formed of a resin molding, a throttle valve 9 opening/closing the bore 5, and the motor 10 driving the throttle valve 9. The throttle body 2 comprises a motor housing 6 having a motor storage space. The motor 10 is formed in such a manner that its entire portion is stored in the motor storage space and its axial both ends are supported on the motor housing 6 through seal members. The motor housing 6 comprises a heat radiation window 32 cut open correspondingly to the center part of the motor 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic throttle device that is used to adjust the intake air amount of an engine and is configured to open and close a throttle valve by a motor.

  Conventionally, this type of electronic throttle device includes a throttle body including a bore, a throttle valve that opens and closes the bore, and a motor provided in the throttle body for driving the throttle valve. For example, the apparatus described in the following patent documents 1 and 2 is mentioned.

  In recent years, resin molded products are sometimes used as throttle bodies in order to reduce the weight. However, since the resin throttle body has poor heat conductivity, the heat dissipation against the heat generated by the motor is not good.

  Therefore, in the apparatus described in Patent Document 1 below, a motor housing space and a heat radiation space having a wall surface opened to the housing space and adjacent to the bore are formed in the resin throttle body. The heat generated by the motor is directly transmitted to the bore in this heat radiation space, and is radiated using the flow of intake air.

  On the other hand, in the apparatus described in Patent Document 2 below, one side (output shaft side) of the motor is cantilevered and fixed to the throttle body with a screw against the resin throttle body, and the other half on the other side of the motor is It is exposed from the throttle body. The heat generated by the motor is radiated from the exposed portion to the outside.

Japanese Patent Application No. 2002-298737 (6th page, FIGS. 1 and 2) Japanese Patent Laid-Open No. 2000-265861 (page 7, FIGS. 2 and 13)

  However, in the device described in the above-mentioned Patent Document 1, the heat radiation space is a closed space inside the throttle body, and there is a tendency that heat is trapped in the closed space, and the heat dissipation is not necessarily sufficient. .

  On the other hand, in the device described in the above-mentioned Patent Document 2, although one side half of the motor is exposed to the outside from the throttle body and the heat dissipation is good, the motor is cantilevered by the throttle body, so the vibration of the motor The measures were not enough. In particular, vibrations in a direction perpendicular to the motor axis (radial direction) could not be sufficiently suppressed. For this reason, there is a possibility that the motor output shaft may be locally worn by the vibration of the motor, and the vibration may be further increased.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic throttle device that can improve heat dissipation against heat generation of a motor and effectively suppress vibration of the motor.

  In order to achieve the above object, an invention according to claim 1 is directed to an electronic throttle device including a throttle body including a bore, a throttle valve that opens and closes the bore, and a motor that drives the throttle valve. Including a motor housing having a motor housing space, the motor being entirely housed in the motor housing space, and both axial ends thereof being supported by the motor housing via elastic members, and the motor housing Includes a heat radiating window that is cut open corresponding to the center of the motor.

  According to the configuration of the present invention, since the heat radiating window is opened in the motor housing, the heat generated by the motor is radiated to the outside of the motor housing through the heat radiating window. Further, since both end portions of the motor in the axial direction are supported by the motor housing via the elastic member, amplification of motor vibration can be suppressed. Furthermore, the energy of the motor vibration is absorbed by the elastic member and attenuated.

  In order to achieve the above object, the invention according to claim 2 is the invention according to claim 1, wherein the throttle body is a resin molded product.

  According to the configuration of the invention described above, in addition to the operation of the invention described in claim 1, the heat generated by the motor is radiated to the outside through the heat radiation window even in the throttle body of the resin molded product having a low thermal conductivity.

  In order to achieve the above object, the invention according to claim 3 is the invention according to claim 1 or 2, wherein the elastic member is a rubber seal member.

  According to the configuration of the invention described above, in the invention according to claim 1 or 2, since the elastic member is a rubber seal member, dust that enters the motor housing space from the heat radiation window is blocked by the seal member. Therefore, dust does not adhere near the both ends of the motor.

  According to invention of Claim 1 or 2, the heat dissipation with respect to the heat_generation | fever of a motor can be improved, and the vibration of a motor can be suppressed effectively.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, it is possible to prevent dust from being blocked by the seal member and to prevent malfunction of the motor due to the dust.

[First Embodiment]
Hereinafter, a first embodiment of an electronic throttle device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a front view of the electronic throttle device 1. FIG. 2 shows a bottom view of the electronic throttle device 1. The electronic throttle device 1 includes a throttle body 2 made of a resin molded product. The throttle body 2 includes a valve housing 3 and a gear case cover 4. The valve housing 3 includes a bore 5 and a motor housing 6 that communicate with an intake passage (not shown) of the engine. The gear case cover 4 closes the open end of the valve housing 3. The gear case cover 4 includes a socket 7 that encloses the wiring terminal 7a.

  FIG. 3 is a longitudinal sectional view of the electronic throttle device 1. The electronic throttle device 1 includes a throttle body 2, a throttle shaft 8, a throttle valve 9, a motor 10, a speed reduction mechanism 11, and an opener mechanism 12 as main components.

  The throttle shaft 8 is disposed through the bore 5, and both ends thereof are rotatably supported by the valve housing 3 via bearings 13 and 14. The throttle valve 9 is fixed on the throttle shaft 8 and is disposed in the bore 5.

  A throttle gear 15 is fixed to one end of the throttle shaft 8. A return spring 16 is provided between the throttle gear 15 and the valve housing 3. The return spring 16 biases the throttle valve 9 in the closing direction. The return spring 16 is one element constituting the opener mechanism 12.

  The base end of the motor 10 is fixed to the valve housing 3 with screws 30. The motor 10 rotates the throttle shaft 8 in order to drive the throttle valve 9 in the opening direction. The motor 10 is drivingly connected to the throttle shaft 8 via the speed reduction mechanism 11. That is, the motor gear 17 is fixed on the output shaft 10 a of the motor 10. A motor gear 17 is connected to the throttle gear 15 via an intermediate gear 18. The intermediate gear 18 is rotatably supported by the valve housing 3 via a pin shaft 19.

  Accordingly, in the fully closed state shown in FIG. 3, the motor 10 is energized to rotate the output shaft 10a in the forward direction, and the motor gear 17 rotates, whereby the rotation is decelerated by the intermediate gear 18 and the throttle gear 15 Is transmitted to. As a result, the throttle shaft 8 and the throttle valve 9 are rotated against the urging force of the return spring 16, and the bore 5 is opened. That is, the throttle valve 9 is opened. Further, in order to hold the throttle valve 9 at a certain opening, a rotational force is generated by energizing the motor 10, so that the rotational force is retained as a holding force via the motor gear 17, the intermediate gear 18 and the throttle gear 15. And is transmitted to the throttle valve 9. When this holding force is balanced with the urging force of the return spring 16, the throttle valve 9 is held at a certain opening.

  The opener mechanism 12 is for holding the throttle valve 9 at an opener opening slightly opened from the fully closed state when the energization to the motor 10 is stopped.

  FIG. 4 is an enlarged sectional view showing a portion surrounded by a two-dot chain line circle in FIG. 3, that is, a portion of the motor housing 6. FIG. 5 is a sectional view taken along line AA in FIG. As shown in FIG. 4, the motor 10 includes a stator 21 and a rotor 22 that rotates in the stator 21. The stator 21 includes a bottomed cylindrical casing 23 that also serves as a yoke, and a field magnet 24 disposed inside the casing 23. The casing 23 is mainly made of iron and forms a magnetic circuit (magnetic field) together with the field magnet 24. In addition, the casing 23 is provided with a brush 25 connected to a terminal (not shown). The rotor 22 includes an output shaft 10a, a commutator 26 and an armature 27. The armature 27 is provided with a winding 28. The winding 28 is configured by connecting coils inserted into a plurality of core grooves (slots) 27 a of the armature 27. The brush 25 is brought into contact with the commutator 26 so that a current flows through the winding 28. When a current flows through the winding 28, a rotational force is generated in the armature 27.

  As shown in FIGS. 4 and 5, the substantially semi-cylindrical motor housing 6 formed in the valve housing 3 has a motor housing space 20 for housing the motor 10 therein. The entire motor 10 is housed in the motor housing space 20 and both axial ends thereof are supported by the motor housing 6 via rubber seal members 31 as elastic members. That is, the seal member 31 is interposed between the outer peripheral surface of the base end portion (right side shown in FIG. 4) of the casing 23 of the motor 10 and the inner peripheral surface of the motor housing 6. A seal member 31 is similarly interposed between the outer peripheral surface of the front end portion of the casing 23 (left side shown in FIG. 4) and the inner peripheral surface of the motor housing 6. The motor housing 6 is formed with a recess 6 a that aligns with the tip protrusion 10 b of the motor 10. In this embodiment, the motor housing 6 includes a heat radiation window 32 that is cut open corresponding to the central portion of the motor 10.

  In this embodiment, the heat radiation window 32 is formed at the same time as the valve housing 3 of the throttle body 2 is molded. 6 and 7 are sectional views showing a method of molding the heat radiation window 32 and the like. 6 is a cross-sectional view corresponding to FIG. 4, and FIG. 7 is a cross-sectional view taken along line BB of FIG. In this embodiment, a first movable mold 42 for forming the motor housing space 20 and a second movable mold for forming the heat radiation window 32 with respect to the fixed mold 41 for molding the valve housing 3. Combine with the mold 43. Then, after filling the cavity 44 formed by these molds 41 to 43 with a molten resin, the movable molds 42 and 43 are moved away from each other as indicated by arrows in FIGS. The motor housing 6 and the heat radiation window 32 in the housing 6 are formed.

  According to the configuration of the electronic throttle device 1 of this embodiment described above, when the motor 10 is energized, the motor gear 17 fixed to the output shaft 10a rotates, and the throttle is connected via the gears 17, 18 and 15, respectively. The shaft 8 rotates and the throttle valve 9 is opened and closed. Here, when the motor 10 is energized, the motor 10 is vibrated by the rotation of the rotor 22. However, in this embodiment, since both end portions in the axial direction of the motor 10 are supported by the motor housing 6 via the rubber seal members 31, amplification of vibration of the motor 10 is suppressed. Further, the vibration energy of the motor 10 is absorbed by the seal member 31 and attenuated. For this reason, generation | occurrence | production of the vibration of the motor 10 can be suppressed effectively.

  In this embodiment, since the heat radiating window 32 is opened in the motor housing 6, even if the valve housing 3 of the throttle body 2 is a resin molded product having a low thermal conductivity, the heat generated by the motor 10 is radiated. Heat is radiated to the outside of the motor housing 6 through the window 32. For this reason, the heat dissipation with respect to the heat_generation | fever of the motor 10 can be improved. Thereby, heating of the motor 10 can be prevented. In particular, the heat generation of the motor 10 occurs in the portion of the winding 28 located in the central portion of the motor 10, and this portion of the winding 28 is aligned with the heat radiation window 32. For this reason, the heat generation of the motor 10 can be directly released to the outside from the heat radiation window 32, and the motor 10 can be cooled efficiently.

  In this embodiment, rubber seal members 31 are interposed between the outer periphery of the casing 23 and the inner periphery of the motor housing 6 at both axial ends of the motor 10. Accordingly, the dust that enters the motor housing space 20 from the heat radiation window 32 is blocked by the seal member 31, and the dust does not adhere to the vicinity of both end portions of the motor 10. In particular, in this embodiment, the hole 10c is opened in the tip convex portion 10b of the motor 10, but since dust is blocked by the seal member 31, the dust does not enter through the hole 10c. For this reason, it is possible to prevent malfunction of the motor 10 due to dust.

[Second Embodiment]
Next, a second embodiment of the electronic throttle device according to the present invention will be described in detail with reference to the drawings. In addition, in each embodiment described below including this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and differences will be mainly described.

  FIG. 8 shows a front view of the electronic throttle device 61. FIG. 9 shows a bottom view of the electronic throttle device 61. FIG. 10 is a cross-sectional view similar to FIG. FIG. 11 is a sectional view taken along line AA in FIG. 12 and 13 are sectional views according to FIGS.

  This embodiment differs from the first embodiment in the configuration of the heat radiation window 32. That is, as shown in FIGS. 8 to 11, the heat radiating window 32 of the motor housing 6 is provided with a rib 33. The rib 33 divides the heat radiation window 32 into two parts.

  12 and 13 are sectional views showing a method of forming the motor housing space 20 and the heat radiation window 32. FIG. In this embodiment, in order to form the rib 33, a rib recess 43a is provided in a part of the second movable mold 43 as shown in FIG. The rib recess 43a is also filled with molten resin.

  Therefore, also in this embodiment, the heat dissipation against heat generated by the motor 10 can be enhanced by the heat dissipation window 32 formed in the motor housing 6. In particular, in this embodiment, since the rib 33 is provided in the heat radiation window 32, the rigidity of the motor housing 6 can be improved. Further, the vibration of the motor 10 can be effectively suppressed by the seal member 31 interposed between the both ends of the motor 10 and the motor housing 6. In addition, in this embodiment, the same operational effects as those of the electronic throttle device 1 of the first embodiment can be obtained.

[Third Embodiment]
Next, a third embodiment of the electronic throttle device according to the present invention will be described in detail with reference to the drawings.

  FIG. 14 shows a front view of the electronic throttle device 62. FIG. 15 shows a bottom view of the electronic throttle device 62. FIG. 16 is a cross-sectional view similar to FIG. FIG. 17 is a sectional view taken along line AA in FIG. 18 and 19 are sectional views corresponding to FIGS.

  This embodiment differs from the first embodiment in the configuration of the motor housing 6 and the heat radiating window. That is, as shown in FIGS. 14 to 16, the motor housing 6 is formed with a fitting hole 6 b that aligns with the tip convex portion 10 b of the motor 10. The plug 34 is fitted into the fitting hole 6b from the inside. Then, the tip convex portion 10 b of the motor 10 is fitted into the recess of the plug 34. A seal member 31 is interposed between the plug 34 and the motor 10. As shown in FIGS. 16 and 17, in this embodiment, the gap 40 between the motor housing 6 and the motor 10 is set larger than that of the first and second embodiments.

  18 and 19 are sectional views showing a method for forming the motor housing space 20 and the heat radiation window 32. FIG. In this embodiment, a first movable mold 45, a second movable mold 46 and a third movable mold 47 are combined with the fixed mold 41. As shown in FIG. 18, the first and second movable molds 45 and 46 are provided so as to be separated from each other in opposite directions. The third movable mold 47 is disposed between the first and second movable molds 45 and 46 so as to be separated in a direction perpendicular to them. A fitting hole 6 b of the motor housing 6 is formed by the second movable mold 46. A part of the motor housing space 20 and the heat radiation window 32 are formed by the third movable mold 47. As shown in FIG. 19, a convex portion 47 a for the motor housing space 20 is provided in a part of the third movable mold 47.

  Therefore, also in this embodiment, the heat dissipation against heat generated by the motor 10 can be enhanced by the heat dissipation window 32 formed in the motor housing 6. Further, in this embodiment, since the motor accommodating space 20 and the heat radiating window 32 are formed by the third movable mold 47, the inner diameter thereof is larger than that of the motor accommodating space 20 of the first and third embodiments. Can be enlarged. For this reason, the gap 40 between the motor housing 6 and the motor 10 is enlarged, and the heat generated by the motor 10 can easily flow to the heat radiation window 32 through the gap 40. As a result, the heat dissipation with respect to the heat generation of the motor 10 can be further enhanced. Further, the vibration of the motor 10 can be effectively suppressed by the seal member 31 interposed between the both end portions of the motor 10 and the motor housing 6. In addition, in this embodiment, the same operational effects as those of the electronic throttle device 1 of the first embodiment can be obtained.

  The present invention is not limited to the above-described embodiments, and can be carried out as follows without departing from the spirit of the invention.

  For example, in each of the above embodiments, the throttle body 2 of a resin molded product is used, but a throttle body of a metal molded product can also be used. Also in this case, the heat dissipation of the heat generated by the motor can be improved by forming a heat dissipation window in the motor housing provided in the throttle body.

The front view which concerns on 1st Embodiment and shows an electronic throttle device. The bottom view which shows an electronic throttle device. The longitudinal cross-sectional view which shows an electronic throttle device. The expanded sectional view which shows the principal part of FIG. AA line sectional view of Drawing 4. Sectional drawing which shows molding methods, such as a heat radiating window. BB sectional drawing of FIG. The front view which concerns on 2nd Embodiment and shows an electronic throttle device. The bottom view which shows an electronic throttle device. The expanded sectional view which shows the principal part. AA sectional view taken on the line AA in FIG. Sectional drawing which shows molding methods, such as a heat radiating window. BB sectional drawing of FIG. The front view which concerns on 3rd Embodiment and shows an electronic throttle device. The bottom view which shows an electronic throttle device. The expanded sectional view which shows the principal part. FIG. 17 is a sectional view taken along line AA in FIG. 16. Sectional drawing which shows molding methods, such as a heat radiating window. BB sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic throttle device 2 Throttle body 5 Bore 6 Motor housing 9 Throttle valve 10 Motor 20 Housing space 20 Motor housing space 31 Seal member 32 Heat radiation window 61 Electronic throttle device 62 Electronic throttle device

Claims (3)

In an electronic throttle device comprising a throttle body including a bore, a throttle valve that opens and closes the bore, and a motor that drives the throttle valve,
The throttle body includes a motor housing having a motor housing space;
The motor is housed entirely in the motor housing space, and both axial ends thereof are supported by the motor housing via elastic members;
An electronic throttle device according to claim 1, wherein the motor housing includes a heat radiating window that is opened corresponding to a central portion of the motor. The electronic throttle device according to claim 1, wherein the throttle body is a resin molded product. The electronic throttle device according to claim 1, wherein the elastic member is a rubber seal member.

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