JP2009281322A - Electronic control throttle body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic control throttle body enabling a rotary shaft of a sun gear and a planetary carrier to be precisely assembled. <P>SOLUTION: The electronic control throttle body is provided with a body 4 having an air intake passage formed in it, a valve stem 7 rotatably supported in the body, a throttle valve fixed with the valve stem in the air intake passage and provided with a valve element 9 capable of varying an opening area of the air intake passage and a motor 3, connected with the valve stem via a speed reduction mechanism 2 for rotating the valve element. The speed reduction mechanism 2 consists of a planetary gear speed reduction mechanism provided with the sun gear 12 fixed with a shaft of the motor, an inner gear 14 formed around the sun gear, the planetary gear 13 meshing with the sun gear and the inner gear and the planetary carrier 16, connected with the planetary gear, having a small gear 17 for rotating coaxially with the motor and a spur gear speed reduction mechanism meshing with the small gear of the planetary gear speed reduction mechanism and having a large gear 18 for transmitting rotation of the motor to the valve stem. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronically controlled throttle body that drives a motor in response to an accelerator pedal operation and rotates a valve body of a throttle valve via a speed reduction mechanism.

  A conventional electronically controlled throttle body, for example, as shown in Patent Document 1, drives a motor in response to an accelerator pedal operation, and controls the opening degree of a valve body of a throttle valve via a speed reduction mechanism. . Specifically, in order to increase the torque generated by the motor to the torque necessary for opening control of the valve body, the torque generated by the motor is changed from the sun gear fixed to the motor shaft to the planetary gear and the internal gear. A planetary gear speed reduction mechanism has been used that decelerates by transmitting to a planet carrier that is fixed to the valve shaft.

JP-A-10-196416

  Since the conventional electronically controlled throttle body is configured as described above, when it is desired to obtain a high reduction ratio without changing the outer dimensions of the planetary gear reduction mechanism, the planetary carrier that is the output shaft of the planetary gear reduction mechanism By combining a spur gear reduction mechanism consisting of a large gear meshing with the small gear at the end of the shaft, the driving force reduced by the planetary gear reduction mechanism is further reduced by the spur gear reduction mechanism and the valve shaft The method of transmitting to was adopted.

  However, when the planetary gear speed reduction mechanism and the spur gear speed reduction mechanism are combined, the planetary carrier of the planetary gear speed reduction mechanism also serves as the small gear of the spur gear speed reduction mechanism, so the space between the planet carrier and the motor shaft that fixes the sun gear. If the positional relationship between the gear and the valve shaft that fixes the large gear of the spur gear reduction mechanism is not accurately placed at the same time, the meshing of the gears will deteriorate and the motor drive force will be transmitted smoothly to the valve shaft. I can't do it.

  In addition, because of the principle of the planetary gear mechanism, the motor shaft and the planet carrier have different rotational speeds, so these components are usually arranged without being connected to each other. When assembling an electronically controlled throttle body that combines such a planetary gear reduction mechanism and a spur gear reduction mechanism, it is necessary to position the planet carrier and the large gear at the same time as positioning the motor and the planet carrier. There is a problem that the assembly of the apparatus is very difficult.

The present invention has been made to solve the above-described problems. The sun gear and the planetary carrier can be assembled with high accuracy, and the motor and the planetary carrier can be fixed in this state. It is an object to provide an electronically controlled throttle body that can be used.
In addition, it is possible to assemble the planetary carrier and the large gear with an accurate distance between the axes, and to relatively easily arrange the motor shaft and the internal gear on which the sun gear is fixed on the same axis. An object is to provide a control throttle body.

  An electronically controlled throttle body according to the present invention includes a body in which an intake passage is formed, a valve shaft that is rotatably supported in the body, and an opening of the intake passage that is fixed to the valve shaft in the intake passage. An electronically controlled throttle body comprising a throttle valve having a valve body capable of changing an area, and a motor coupled to the valve shaft via a speed reduction mechanism to rotate the valve body, the speed reduction mechanism comprising: A sun gear fixed to the shaft of the motor, an internal gear formed around the sun gear, a planetary gear meshing with the sun gear and the internal gear, and coupled to the planetary gear and coaxial with the motor A planetary gear reduction mechanism comprising a planetary carrier having a small gear rotating above, and a flat gear having a large gear that meshes with the small gear of the planetary gear reduction mechanism and transmits the rotation of the motor to the valve shaft. tooth Those comprised of a speed reduction mechanism.

  Since the present invention is configured as described above, the sun gear and the rotating shaft of the planet carrier can be assembled with high accuracy, and the positions of the motor and the planet carrier can be fixed in this state. Is.

  At the same time, it is possible to accurately assemble the inter-axis distance between the planet carrier having the small gear of the planetary gear reduction mechanism and the large gear of the spur gear reduction mechanism.

  Further, the motor shaft and the internal gear for fixing the sun gear can be arranged on the same axis relatively easily.

  Other features and effects of the present invention will become apparent from the description of embodiments and drawings described below.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing a configuration of an electronically controlled throttle body according to Embodiment 1, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. In these drawings, the electronically controlled throttle body includes a throttle valve 1, a speed reduction mechanism 2 connected to the throttle valve 1, and a motor 3 connected to the speed reduction mechanism 2.

  The throttle valve 1 includes a cylindrical body 4 made of aluminum in which an intake passage 8 is formed in a direction perpendicular to the paper surface, and a first bearing 5 and a second bearing 6 on the left and right walls of the body 4 in FIG. In the vicinity of the first bearing 5, a valve shaft 7 that is rotatably supported via the valve body 9, a valve body 9 that is fixed to the valve shaft 7 and changes the opening area of the intake passage 8 according to the rotation of the valve shaft. And a spring 10 that urges the valve shaft 7 in the valve closing direction.

  The speed reduction mechanism 2 includes a planetary gear speed reduction mechanism and a spur gear speed reduction mechanism, which will be described later. The planetary gear speed reduction mechanism includes a sun gear 12 that is fixed to the motor shaft 11 of the motor 3 by press-fitting, an internal gear 14 that is formed so as to surround the sun gear 12, and a space between the sun gear 12 and the internal gear 14. The planetary gear 13 that meshes with both the gears 12, 14, the planetary carrier 16 that supports the planetary gear 13 so as to rotate and revolve, and the planetary carrier 16 that is integrally formed on the anti-planetary gear side. And a small gear 17. The spur gear reduction mechanism is constituted by a large gear 18 fixed to the left end portion of the valve shaft 7 and meshing with the small gear 17.

  A third bearing 20 is press-fitted into the planet carrier 16, and the motor shaft 11 is press-fitted and fixed to the third bearing 20, so that the motor 3 and the planet carrier 16 can rotate on the same axis. Has been. The planet carrier 16 is rotatably supported by a pin 19 provided concentrically with the motor shaft 11, and the pin 19 is press-fitted into the body 4.

  The internal gear 14 is integrally formed with a plate 15 having a fitting hole 15 a centered on the gear shaft, and the boss 3 a of the motor 3 is press-fitted into the fitting hole 15 a of the plate 15. The speed reduction mechanism 2 described above is covered with a cover 21 together with the motor 3.

  The rotation angle of the valve shaft 7 is detected by a sensor 22 arranged in the distal direction from the position where the large gear 18 of the valve shaft 7 is fixed. The opening degree signal detected by the sensor 22 is transmitted to the outside by a connector 24 formed integrally with the cover 21. The connector 24 constitutes a terminal for flowing current to the motor 3. The body 4 and the cover 21 are fixed by screws (not shown) with the plate 15 sandwiched therebetween.

  In the electronically controlled throttle body configured as described above, the air sucked through the air filter (not shown) on the intake upstream side is introduced into the intake passage 8 in the body 4. The introduced air has its intake flow rate adjusted in accordance with the opening degree of the valve body 9 rotated against the elastic force of the spring 10 by driving the motor 3 through the speed reduction mechanism 2. The adjusted air is led to an engine that is airtightly arranged on the downstream side of the throttle valve 1, and is mixed with fuel supplied from a fuel injection valve (not shown) in a combustion chamber and ignited.

  In the electronically controlled throttle body of the first embodiment configured as described above, the torque generated by the motor 3 is decelerated by the sun gear 12, the planetary gear 13, the internal gear 14, and the planetary carrier 16, and is applied to the small gear 17. Communicated. The torque transmitted to the small gear 17 is further decelerated by the large gear 18 that meshes with the small gear 17 and transmitted to the valve shaft 7.

  Here, in the electronically controlled throttle body of the first embodiment, since the motor shaft 11 into which the sun gear 12 is press-fitted and the planet carrier 16 are connected and fixed by the third bearing 20, the sun gear 12 and the planet carrier 16. Are necessarily arranged coaxially.

Further, as described above, the internal gear 14 is formed integrally with the plate 15, and the plate 15 is press-fitted into the boss 3 a of the motor 3 through the fitting hole 15 a centering on the gear shaft of the internal gear 14. The gear shaft of the gear 14 and the shaft center of the motor 3 are arranged substantially coaxially.
Therefore, in a state where the motor 3 and the plate 15 are integrated, the planetary gear 13 is engaged with the sun gear 12 and the internal gear 14, and the motor shaft 11 and the planet carrier 16 are connected and fixed by the third bearing 20. The central axes of the sun gear 12, the internal gear 14, and the planetary carrier 16 are arranged on the same axis, and the gears of the planetary gear reduction mechanism can maintain a good meshing state. Furthermore, since the position of the planetary gear mechanism including the motor 3 and the sun gear 12, the planetary gear 13, the internal gear 14, and the planet carrier 16 is fixed in this state, each of the planetary gear mechanisms is assembled by assembling them to the body 4. The device can be easily assembled without shifting the positional relationship of the gears.

In the state in which the motor 3 and the sun gear 12, the planetary gear 13, the internal gear 14, and the planetary carrier 16 are in a set, the pin that is press-fitted into the body 4 with a pin hole that is opened on the side opposite to the motor shaft of the planetary carrier 16 Insert at the tip of 19. A small gear 17 provided on the planetary carrier 16 on the side opposite to the planetary gear is meshed with a large gear 18 fixed to the valve shaft 7 of the throttle valve to constitute a spur gear reduction mechanism.
Here, since the distance between the pin 19 and the valve shaft 7 is determined by the processing accuracy of the body 4, the positional accuracy of the spur gear reduction mechanism can be obtained without taking any special means, and the gears mesh stably. Can be.

When the electronically controlled throttle body according to the first embodiment is assembled as described above, the positional relationship among the sun gear 12, the internal gear 14, and the planetary carrier 16 is such that the boss portion 3a of the motor 3 and the coaxiality of the motor shaft 11, the motor shaft The gear accuracy of the sun gear 12 with respect to the shaft 11, the gear accuracy of the internal gear 14 with respect to the shaft of the fitting hole 15 a of the plate 15, and the small gear 17 with respect to the third bearing 20 that connects and fixes the planet carrier 16 and the motor shaft 11. Since it is determined by the gear accuracy, it is not necessary to adjust the position during assembly.
Similarly, the positional relationship between the small gear 17 and the large gear 18 is determined by the positional accuracy of the hole for press-fitting the pin 19 of the body 4 and the second bearing 6, so it is necessary to adjust the position during assembly. As a result, the efficiency at the time of assembly is increased and the productivity can be improved.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a cross-sectional view showing a configuration of an electronically controlled throttle body according to the second embodiment. In FIG. 3, the same or corresponding parts as those in FIGS. 1 and FIG. 2 is that a pin 19 is integrally formed on the anti-planetary gear side of the planet carrier 16 and the fourth bearing 23 is press-fitted into the body 4. It is the point which supported so that rotation was possible.

According to the second embodiment, the positional accuracy of the small gear 17 and the large gear 18 is determined by the positional accuracy of the holes into which the second bearing 6 and the fourth bearing 23 of the body 4 are press-fitted. There is no need to make adjustments, and assembling efficiency increases and productivity can be improved.
Further, by providing the pin 19 integrally with the planet carrier 16 on the side opposite to the planetary gear, no pin hole is required. As a result, it is not necessary to ensure the thickness between the tooth bottom of the small gear 17 and the pin hole, and the pitch diameter of the small gear 17 can be reduced. Accordingly, when the same reduction ratio is obtained, the pitch diameter of the large gear 18 can be reduced, so that the apparatus can be miniaturized.

It is sectional drawing which shows the structure of the electronically controlled throttle body by Embodiment 1 of this invention. It is a fragmentary sectional view which shows the cross section in the AA of FIG. It is sectional drawing which shows the structure of the electronically controlled throttle body by Embodiment 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Throttle valve, 2 Reduction mechanism, 3 Motor, 4 Body, 7 Valve shaft, 8 Intake passage, 9 Valve body, 11 Motor shaft, 12 Sun gear, 13 Planetary gear, 14 Internal gear, 15 Plate, 16 Planetary carrier, 17 Small gear, 18 large gear, 19 pin, 20 bearing, 21 cover, 22 sensor, 23 bearing, 24 connector.

Claims (3)

A throttle having a body in which an intake passage is formed, a valve shaft rotatably supported in the body, and a valve body fixed to the valve shaft in the intake passage and capable of changing an opening area of the intake passage. An electronically controlled throttle body comprising a valve and a motor coupled to the valve shaft via a speed reduction mechanism and rotating the valve body,
The speed reduction mechanism is coupled to the sun gear fixed to the shaft of the motor, an internal gear formed around the sun gear, a planetary gear meshing with the sun gear and the internal gear, and the planetary gear. A planetary gear reduction mechanism including a planetary carrier having a small gear that rotates coaxially with the motor, and meshes with the small gear of the planetary gear reduction mechanism to transmit the rotation of the motor to the valve shaft. An electronically controlled throttle body comprising a spur gear reduction mechanism having a large gear.   The internal gear is integrally formed with a plate having a fitting hole centered on the gear shaft, and a part of the motor is fitted into the fitting hole of the plate. The electronically controlled throttle body according to 1.   The electronically controlled throttle body according to claim 1 or 2, wherein the planetary carrier is rotatably supported by a shaft or a bearing fixed to the body with a constant axial distance from the valve shaft. .

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