JP2005146992A - Electronic throttle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve durability of a DC motor by preventing adhesion of lubricating oil to a commutator and adhesion of brush wear powder to a bearing, and to secure durability of an electronic throttle device under a severe use condition. <P>SOLUTION: The DC motor 10 used in the electronic throttle device includes the commutator 26 and the metal bearing 29 provided on an output shaft 10a so as to adjacent to each other, and a washer 40 interposed between the commutator 26 and the metal bearing 29. The washer 40 has a short cylindrical shape, and includes a peripheral groove 40a between a pair of flanges located at the both ends of the washer 40. Out of the pair of the flanges, the flange in the commutator 26 side has an outer diameter larger than that of the flange in the metal bearing 29 side and that of the commutator 26. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic throttle device that is provided in an intake passage of an engine and that opens and closes a throttle valve by a DC 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 DC motor that is provided in the throttle body and drives the throttle valve. Examples of this type of apparatus include the techniques described in Patent Documents 1 and 2 below. Since this type of device is frequently used during engine operation, the DC motor is required to have durability under harsh usage conditions.

  On the other hand, Patent Document 3 below describes a small DC motor that can be used in an electronic throttle device. As shown in FIG. 10, this DC motor is provided with a bearing 61 and a rotor bush 62 adjacent to each other on one end of a motor shaft (output shaft) 60, and between the bearing 61 and the rotor bush 62. A plurality of washers 63 are interposed between the two. These washers 63 regulate the backlash of the output shaft 60 in the thrust direction. On the other end of the output shaft 60, a commutator that is in sliding contact with the brush and a bearing are provided adjacent to each other.

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) Japanese Utility Model Publication No. 2-303059 (page 1-2, FIGS. 1 and 5)

  However, in the DC motor described in Patent Document 3, the plurality of washers 63 only have a function of regulating backlash in the thrust direction. In this type of DC motor, lubricating oil is used for the bearing, and the brush is in sliding contact with the commutator. Further, a washer is generally interposed between the commutator and the bearing. For this reason, there is a risk of contact failure if the bearing lubricating oil adheres to the commutator, and if the brush wear powder adheres to the bearing, the slidability with the output shaft may deteriorate, which causes the DC motor to operate. There was a risk of failure. However, the washer described above did not have a function of preventing the lubricant from adhering to the commutator and a function of preventing the wear powder from adhering to the bearing. For this reason, in order to ensure sufficient durability for an electronic throttle device used under severe conditions, in a DC motor, lubricant oil adheres to the commutator or wear powder adheres to the bearing. It is desired to effectively prevent this with a simple configuration.

  The present invention has been made in view of the above circumstances, and its purpose is to prevent the durability of the DC motor by preventing the lubricating oil from adhering to the commutator and the brush abrasion powder from adhering to the bearing. It is an object of the present invention to provide an electronic throttle device that can improve the durability and ensure the durability under severe use conditions.

  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 DC motor that drives the throttle valve. Includes an output shaft, a commutator and a bearing provided adjacent to each other on the output shaft, and a washer interposed between the commutator and the bearing. The washer has a recess or a groove on its outer periphery. The purpose is to include.

  According to the configuration of the invention, the lubricating oil leaking from the bearing is collected in the recess or groove on the outer periphery of the washer, and the adhesion to the commutator is stopped. The abrasion powder coming out of the brush that is in sliding contact with the commutator is collected in a recess or groove on the outer periphery of the washer, and is prevented from adhering to the bearing.

  To achieve the above object, according to a second aspect of the present invention, in the electronic throttle device according to the first aspect of the present invention, the washer has a short cylindrical shape, a pair of flanges at both ends thereof, and a pair of flanges. The purpose is to include a circumferential groove between the flanges.

  According to the configuration of the above invention, the lubricating oil leaking from the bearing is collected in the peripheral groove of the washer, and the adhesion to the commutator is stopped. The abrasion powder coming out of the brush that is in sliding contact with the commutator is collected in the peripheral groove of the washer, and the adhesion to the bearing is stopped.

  In order to achieve the above object, according to a third aspect of the present invention, in the electronic throttle device of the second aspect of the present invention, of the two flanges in the washer, the flange on the commutator side is on the bearing side. The gist is that the outer diameter is larger than the flange and the outer diameter is larger than the commutator.

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 2, the flange on the commutator side has a larger outer diameter than the flange on the bearing side, and has a larger outer diameter than the commutator. Therefore, the lubricating oil leaking from the bearing is blocked by the flange on the commutator side and collected in the circumferential groove, and the adhesion to the commutator is stopped. The abrasion powder coming out of the brush that is in sliding contact with the commutator is guided by the flange on the commutator side and collected in the circumferential groove of the washer, and is prevented from adhering to the bearing.

  In order to achieve the above object, a fourth aspect of the present invention is a DC motor that is provided in an electronic throttle device and that opens and closes a throttle valve. The DC motor is adjacent to an output shaft and the output shaft. And a washer interposed between the commutator and the bearing, and the washer is intended to include a recess or a groove on the outer periphery thereof.

  According to the configuration of the invention, the lubricating oil leaking from the bearing is collected in the recess or groove on the outer periphery of the washer, and the adhesion to the commutator is stopped. The abrasion powder coming out of the brush that is in sliding contact with the commutator is collected in a recess or groove on the outer periphery of the washer, and is prevented from adhering to the bearing.

  In order to achieve the above object, according to a fifth aspect of the present invention, in the DC motor according to the fourth aspect of the present invention, the washer has a short cylindrical shape, and the flanges at both ends thereof are interposed between the flanges. The purpose is to include a certain circumferential groove.

  According to the configuration of the above invention, the lubricating oil leaking from the bearing is collected in the peripheral groove of the washer, and the adhesion to the commutator is stopped. The abrasion powder coming out of the brush that is in sliding contact with the commutator is collected in the peripheral groove of the washer, and the adhesion to the bearing is stopped.

  In order to achieve the above object, according to a sixth aspect of the present invention, in the DC motor of the fifth aspect of the present invention, of the two flanges in the washer, the flange on the commutator side is the flange on the bearing side. The outer diameter is larger than that of the commutator, and the outer diameter is larger than that of the commutator.

  According to the configuration of the above invention, in addition to the action of the invention according to claim 5, the flange on the commutator side has a larger outer diameter than the flange on the bearing side, and has a larger outer diameter than the commutator. Therefore, the lubricating oil leaking from the bearing is blocked by the flange on the commutator side and collected in the circumferential groove, and the adhesion to the commutator is stopped. The abrasion powder coming out of the brush that is in sliding contact with the commutator is guided by the flange on the commutator side and collected in the circumferential groove of the washer, and is prevented from adhering to the bearing.

  According to the first to third aspects of the present invention, it is possible to prevent the lubricating oil from adhering to the commutator and the brush abrasion powder from adhering to the bearing, thereby improving the durability of the DC motor. As a result, the durability of the electronic throttle device used under severe conditions can be ensured.

  According to the fourth to sixth aspects of the present invention, it is possible to prevent the lubricating oil from adhering to the commutator and the brush wear powder from adhering to the bearing in the DC motor provided in the electronic throttle device. As a result, the durability of the DC motor can be improved.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which an electronic throttle device of the present invention and a DC motor used therein 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 side view of the electronic throttle device 1. The electronic throttle device 1 includes a throttle body 2. 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 DC 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 DC motor 10 is fixed to the valve housing 3 with screws 30. The DC motor 10 rotates the throttle shaft 8 in order to drive the throttle valve 9 in the opening direction. The DC 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 DC 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.

  Therefore, in the fully closed state shown in FIG. 3, when the DC motor 10 is energized and the output shaft 10a rotates in the forward direction and the motor gear 17 rotates, the rotation is decelerated by the intermediate gear 18 and the throttle gear. 15 is transmitted. 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 DC motor 10, and the rotational force is held as a holding force via the motor gear 17, the intermediate gear 18 and the throttle gear 15. 8 and 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 DC motor 10 is stopped.

  As shown in FIGS. 1 to 3, the substantially semi-cylindrical motor housing 6 formed in the valve housing 3 has a motor housing space 20 for housing the DC motor 10 therein. The entire DC 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 front end portion (the right side shown in FIG. 3) of the DC 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 base end portion (left side shown in FIG. 3) of the DC motor 10 and the inner peripheral surface of the motor housing 6. Further, the motor housing 6 includes a heat radiating window 32 that is opened corresponding to the central portion of the DC motor 10.

  In FIG. 4, the DC motor 10 is partially broken and shown in an enlarged view. The DC 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) 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 FIG. 4, a commutator 26 and a metal bearing 29 are provided adjacent to each other at the tip of the output shaft 10 a of the DC motor 10. A washer 40 is interposed between the commutator 25 and the metal bearing 29. The washer 40 includes a circumferential groove 40a that is continuous with the outer periphery thereof.

  5 and 6 are enlarged sectional views of the washer 40. FIG. The washer 40 has a short cylindrical shape having a center hole 40b, and includes a pair of flanges 40c and 40d at both ends thereof and a circumferential groove 40b having a rectangular cross section between the pair of flanges 40c and 40d. In this embodiment, of the two flanges 40c and 40d of the washer 40, the outer diameter D1 of the first flange 40c on the commutator 26 side is the outer diameter of the second flange 40d on the metal bearing 29 side. It is larger than D2 and larger than the outer diameter D3 of the commutator 26. The outer diameter D2 of the second flange 40d is set smaller than the outer diameter D4 of the metal bearing 29. In this embodiment, the outer diameter D1 of the first flange 40c is “9.0 mm”, the outer diameter D2 of the second flange 40d is “7.0 mm”, and the outer diameter D5 in the circumferential groove 40a is “ The inner diameter D6 of the center hole 40b is set to “3.0 mm”, and the width W1 of the washer 40 is set to “2.0 mm”. The dimensions such as the outer diameters D1 to D5 and the width W1 are not limited to the set values described above, and are appropriately changed according to the size of the applied DC motor.

  According to the configuration of the electronic throttle device 1 of this embodiment described above, when the DC motor 10 is energized, the motor gear 17 fixed to the output shaft 10a rotates, and the respective gears 17, 18, and 15 are rotated. The throttle shaft 8 rotates and the throttle valve 9 is opened and closed.

  Here, in the DC motor 10 used in the electronic throttle device 1, a washer 40 is interposed between the commutator 26 and the metal bearing 29 provided adjacent to each other on the output shaft 10a. Includes a circumferential groove 40a. Accordingly, the lubricating oil leaking from the metal bearing 29 is collected in the circumferential groove 40a of the washer 40, and adhesion of the lubricating oil to the commutator 26 is stopped. Further, the abrasion powder that comes out of the brush 25 by sliding contact with the commutator 26 is collected in the circumferential groove 40a of the washer 40, and is prevented from adhering to the metal bearing 29. At this time, the first flange 40c on the commutator 26 side has a larger outer diameter D1 than the second flange 40d on the metal bearing 29 side, and the outer diameter D1 is larger than the commutator 26. The lubricating oil leaking from the metal bearing 29 is blocked by the first flange 40c and collected in the circumferential groove 40a, and the adhesion to the commutator 26 is stopped. Further, the abrasion powder coming out of the commutator is guided by the first flange 40c and collected in the circumferential groove 40a, and the adhesion to the metal bearing 29 is stopped. That is, it is possible to prevent the lubricating oil from adhering to the commutator 26 and the brush wear powder from adhering to the metal bearing 29. For this reason, in the commutator 26, it is possible to suppress contact failure due to adhesion of lubricating oil, and in the metal bearing 29, it is possible to suppress deterioration in the slidability of the output shaft 10a due to adhesion of wear powder. It is possible to effectively prevent the motor 10 from malfunctioning, and the durability of the DC motor 10 can be improved. Moreover, the durability of the DC motor 40 as described above can be improved with a simple configuration in which the washer 40 is simply provided with the circumferential groove 40a. As a result, sufficient durability can be ensured for the electronic throttle device 1 used under severe conditions.

  In this embodiment, when the DC motor 10 is energized, the DC motor 10 is vibrated by the rotation of the rotor 22. However, in this embodiment, both end portions in the axial direction of the DC motor 10 are supported by the motor housing 6 via the rubber seal member 31, so that vibration amplification of the motor 10 is suppressed. Further, the vibration energy of the DC motor 10 is absorbed by the seal member 31 and attenuated. For this reason, generation | occurrence | production of the vibration of the DC motor 10 can be suppressed effectively.

  In this embodiment, since the heat radiating window 32 is cut and 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 DC motor 10 is radiated. It is discharged 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 DC motor 10 can be improved. Thereby, the heating of the DC motor 10 can be prevented. In particular, the DC motor 10 generates heat at a portion of the winding 28 located at the center 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 DC motor 10 can be directly released to the outside from the heat radiation window 32, and the motor 10 can be cooled efficiently.

  Furthermore, 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 DC motor 10. Therefore, 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 ends of the DC motor 10. In particular, in this embodiment, the hole 10c is opened in the tip convex portion 10b of the DC motor 10, but since the dust is blocked by the seal member 31, the dust does not enter from the hole 10c. For this reason, it is possible to prevent the DC motor 10 from malfunctioning due to dust.

  In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the meaning of invention, it can also implement as follows.

  (1) In the above embodiment, for the washer 40, the outer diameter D1 of the first flange 40c is set larger than the outer diameter D2 of the second flange 40d, but the outer diameters D1 and D2 are set to the same size. May be.

  (2) In the above embodiment, as shown in FIG. 5, the washer 40 including the circumferential groove 40a having a square cross section is provided between the pair of large and small flanges 40c and 40d. However, as shown in FIG. A washer 50 including a circumferential groove 50c having a triangular cross section is provided between the pair of flanges 50a and 50b, or a circumferential groove 51c having a curved cross section between the pair of large and small flanges 51a and 51b as shown in FIG. May be provided.

  (3) In the above embodiment, as shown in FIG. 5, the washer 40 including one circumferential groove 40a is provided between the pair of large and small flanges 40c, 40d. However, as shown in FIG. A washer 52 including two circumferential grooves 52d and 52e may be provided between 52a, 52b and 52c.

  (4) Although the washer 40 including the continuous circumferential groove 40a on the outer periphery is provided in the embodiment, a washer including a plurality of dents that are not continuous with each other may be provided instead of the continuous circumferential groove.

The front view which concerns on one Embodiment and shows an electronic throttle device. The side view which shows an electronic throttle device. The longitudinal cross-sectional view which shows an electronic throttle device. The side view which cuts and shows a DC motor partially. Sectional drawing which shows a washer. Sectional drawing which shows the dimension etc. of a washer. Sectional drawing which concerns on another embodiment and shows a washer. Sectional drawing which concerns on another embodiment and shows a washer. Sectional drawing which concerns on another embodiment and shows a washer. Sectional drawing which shows a part of DC motor of a prior art example.

Explanation of symbols

1 Electronic throttle device 2 Throttle body 5 Bore 9 Throttle valve 10 DC motor 26 Commutator 29 Metal bearing 40 Washer 40a Circumferential groove 40c First flange 40d Second flange 50 Washer 50a Flange 50b Flange 50c Circumferential groove 51 Washer 51a Flange 51b Flange 51c circumferential groove 52 washer 52a flange 52b flange 52c flange 52d circumferential groove 52e circumferential groove

Claims (6)

In an electronic throttle device comprising a throttle body including a bore, a throttle valve that opens and closes the bore, and a DC motor that drives the throttle valve,
The DC motor includes an output shaft, a commutator and a bearing provided adjacent to each other on the output shaft, and a washer interposed between the commutator and the bearing, and the washer includes An electronic throttle device comprising a recess or groove on the outer periphery. 2. The electronic throttle device according to claim 1, wherein the washer has a short cylindrical shape and includes a pair of flanges at both ends thereof and a circumferential groove between the pair of flanges. The flange on the commutator side of the two flanges in the washer has a larger outer diameter than a flange on the bearing side and a larger outer diameter than the commutator. Electronic throttle device as described in 2. A DC motor provided in an electronic throttle device for opening and closing a throttle valve;
The DC motor includes an output shaft, a commutator and a bearing provided adjacent to each other on the output shaft, and a washer interposed between the commutator and the bearing, and the washer includes A DC motor for an electronic throttle device, comprising a recess or groove on the outer periphery. The DC motor of the electronic throttle device according to claim 4, wherein the washer has a short cylindrical shape, and includes flanges at both ends thereof and a circumferential groove between both flanges. The flange on the commutator side of the two flanges in the washer has a larger outer diameter than a flange on the bearing side and a larger outer diameter than the commutator. The DC motor of the electronic throttle device described in 1.

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