JP2003214194A - Throttle valve device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throttle body 1 capable of keeping the smooth rotation of a driven gear 73 even though the driven gear 73 is worn out, by forming a space capable of allowing a foreign matter to stay there, besides an ordinary clearance formed on a fitting part of the driven gear 73 and a fixed shaft 11. <P>SOLUTION: A spiral groove 73d is formed on an inner peripheral face of a central hole 73c of the driven gear 73 as the space for allowing the foreign matter generated on the fitting part such as the worn powder of the driven gear 73 and a foreign matter intruded in the fitting part from the external to stay there, at the fitting part of the driven gear 73 and the fixed shaft 11. Whereby the foreign matter can be prevented from staying in a contact part of the inner peripheral face of the central hole 73c and the fixed shaft 11 by allowing the foreign matter to stay in the groove 73d in a case when the worn powder is generated by the abrasion of the inner peripheral face of the driven gear 73 during the operation of the throttle body 1, or in a case when the fine foreign matter is intruded into the fitting part of the driven gear 73 and the fixed shaft 11 from the external, and the smooth rotation of the driven gear 73 can be continuously secured. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve device preferably used for adjusting the intake air amount of an automobile engine, for example.

[0002]

2. Description of the Related Art As a throttle valve device of this type,
For example, there is one disclosed in Japanese Patent Laid-Open No. 11-343878. This throttle valve device includes a main body in which an intake passage of an engine is formed, a valve shaft rotatably provided in the main body, and a valve shaft extending in a radial direction of the intake passage, and a valve shaft located in the intake passage and attached to the valve shaft. And a valve element and the like that rotate together with the valve shaft to open and close the intake passage.

Further, the main body is provided with a motor for driving the valve shaft and a reduction gear mechanism for transmitting the rotational force of the motor to the valve shaft. The reduction gear mechanism is rotatably driven by a first gear provided on the output shaft of the motor, a second gear provided on the valve shaft, and the first gear to rotate the second gear.
And a driven gear for rotating the gear. The center hole of this driven gear is rotatably fitted to a fixed shaft provided in the main body. When electric power is supplied from the outside to rotate the output shaft of the motor in the conventional throttle valve device configured as described above, the driving force is transmitted from the first gear to the driven gear, and further, from the driven gear to the first gear. It is transmitted to the second gear and the valve shaft rotates integrally with the second gear. As a result, the valve body rotates in the intake passage to open and close the intake passage. That is, it is possible to adjust the intake air amount of the engine to a desired value by changing the effective sectional area of the intake passage.

[0004]

By the way, when the driven gear rotates around the fixed shaft, the outer peripheral surface of the fixed shaft becomes rough,
Alternatively, if there is a scratch or the like, the inner peripheral surface of the driven gear may be worn, and the abrasion powder may be accumulated between the driven gear and the fixed shaft to hinder the smooth rotation of the driven gear. Since the driven gear cannot rotate smoothly, the valve body cannot rotate smoothly, and as a result, it may be difficult to adjust the intake air amount of the engine.

As a countermeasure for this, it is conceivable that the fitting portion of the driven gear with the fixed shaft is made of a material having excellent wear resistance, but there is a problem that the cost increases.

The present invention has been made in view of the above-mentioned problems of the prior art, and an easy means of forming a space in which foreign matter can stay in the fitting portion between the driven gear and the fixed shaft, in addition to the normal clearance. It is an object of the present invention to provide a throttle valve device capable of maintaining smooth rotation of the driven gear even when the inner peripheral surface of the driven gear is worn.

[0007]

In order to achieve the above object, the present invention employs the following technical means.

In the throttle valve device according to the first aspect of the present invention, foreign matter generated in the fitting portion or foreign matter entering the fitting portion can be retained in the fitting portion between the driven gear and the fixed shaft. The space is formed. As a result, when abrasion powder is generated due to wear of the driven gear or the like during operation of the throttle valve device, or when fine foreign matter enters the fitting part between the driven gear and the fixed shaft from the outside, these foreign matter are removed. The driven gear can be retained in the space described above to maintain the smooth rotation of the driven gear.

In the throttle valve device according to the second aspect of the present invention, the space is a spiral groove provided on the inner peripheral surface of the center hole of the driven gear. Accordingly, when the driven gear is formed by molding (for example, resin molding or die casting), the space can be easily formed.

In the throttle valve device according to the third aspect of the present invention, the space is a groove formed in the inner peripheral surface of the center hole of the driven gear in the axial direction of the center hole. Accordingly, when the driven gear is formed by molding (for example, resin molding or die casting), the space can be easily formed.

In the throttle valve device according to the fourth aspect of the present invention, the space is a circumferential groove of the fixed shaft or a spiral groove provided on the outer peripheral surface of the fixed shaft. Thereby, a space can be easily formed in the fixed shaft.

In the throttle valve device according to the fifth aspect of the present invention, the space is a groove provided on the outer peripheral surface of the fixed shaft in the axial direction of the fixed shaft. Thereby, a space can be easily formed in the fixed shaft.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A throttle valve device according to an embodiment of the present invention will be described below with reference to the drawings, taking as an example a case where the throttle valve device is applied to a throttle body for adjusting an intake air amount of an automobile engine.

FIG. 1 shows a sectional view of a throttle body 1 according to an embodiment of the present invention. In FIG.
The valve body 4 is in the fully closed position. That is, the valve body 4 is
In FIG. 1, it is substantially parallel to the paper surface.

The throttle body 1 is mainly composed of a body 2 which is a main body in which an air passage 3 is formed, a valve body 4 which is fixed to a valve shaft 5 to open and close the air passage 3, and a reduction gear mechanism 7. And a motor 6 as a driving force source for rotating the valve body 4. Then, the intake air amount of the engine is adjusted by being installed in the middle of the intake pipe of the engine (not shown) and rotating the valve body 4 to change the effective design area of the air passage 3.

The body 2, which is the main body, is formed of, for example, aluminum die casting or the like, and is provided with an air passage 3 which forms a part of an intake passage of an engine (not shown). In this air passage 3, the air flow direction, that is, the air passage 3
A valve shaft 5 extending in a direction substantially orthogonal to the axial direction (the direction perpendicular to the paper surface in FIG. 1) is rotatably held by the body 2. Both ends of the valve shaft 5 are supported by a bearing 8 such as a dry bearing and a ball bearing 9. A cap 10 is provided outside the ball bearing 9 (downward in FIG. 1).
Is press-fitted into the body 2, and a seal ring (not shown) is mounted between the outer ring (not shown) of the bearing 8 and the valve shaft 5 to maintain airtightness in the air passage 3.

The valve body 4 is fixed to the valve shaft 5. The valve body 4 is made of a circular metal plate or the like corresponding to the inner diameter of the air passage 3, and is rotated together with the valve shaft 5 to rotate the air passage 3
Open and close. That is, the valve body 4 rotates from the fully closed position shown in FIG. 1 to a fully opened position rotated by approximately 90 degrees, that is, a position in which the valve body 4 is substantially vertical to the paper surface in FIG. A second gear 72, which is one of the constituent elements of the reduction gear mechanism 7 that transmits the driving force of the motor 6 to the valve shaft 5, is fixed to one end of the valve shaft 5.

The motor 6 for rotating the valve shaft 5 is a motor 6
So that the output shaft 6a of is in a positional relationship parallel to the valve shaft 5,
It is held and fixed in the body 2. A first gear 71, which is one of the constituent elements of the reduction gear mechanism 7 that transmits the driving force of the motor 6 to the valve shaft 5, is fixed to one end of the output shaft 6a.

The reduction gear mechanism 7 is the first gear 7 described above.
It is composed of a first gear 72, a second gear 72, and a driven gear 73 that is driven to rotate by the first gear 71 to rotate the second gear 72.

The driven gear 73 is made of high-strength resin or the like, and is rotatably fitted to a fixed shaft 11 press-fitted and fixed to the body 2 through a center hole 73c. The driven gear 73 has a large-diameter gear portion 73a that meshes with the first gear 71.
And the second gear 7 provided coaxially with the large-diameter gear portion 73a.
2 and a small-diameter gear portion 73b that meshes with it. These 3
The rotational force of the motor 6 is reduced by the individual gears 71, 72, 73, and a large rotational torque is transmitted to the valve shaft 5 to reliably open / close the valve body 4. Center hole 73 of driven gear 73
As a space in which the foreign matter generated at the fitting portion of the central hole 73c and the fixed shaft 11 or the foreign matter entering the fitting portion from the outside can be retained on the inner surface of c, the driven gear 73 of FIG.
A spiral groove 73d as shown in the sectional view of FIG. The groove 73d is formed at the same time when the driven gear 73 is molded with resin or the like. Since the groove 73d has a spiral shape, it is easy to rotate the driven gear 73 and the molding die (not shown) relatively. Can be separated into

Here, if the outer peripheral surface of the fixed shaft 11 is roughened or scratched, and the inner peripheral surface of the driven gear 73 is abraded to generate abrasion powder, in the conventional throttle body, the center of the driven gear 73 is formed. Since the hole 73c is formed as a straight hole, abrasion powder may stick to the gap between the driven gear 73 and the fitting portion of the fixed shaft 11 and hinder the smooth rotation of the driven gear 73. On the other hand, in the throttle body 1 according to the embodiment of the present invention, a spiral groove 73d is provided on the inner surface of the center hole 73c of the driven gear 73 so that the above-mentioned wear powder is retained in the groove 73d. As a result, abrasion powder is prevented from sticking to the fitting portion between the driven gear 73 and the fixed shaft 11 and hindering the smooth rotation of the driven gear 73, and the smooth rotation of the driven gear 73 is continuously maintained. Can be maintained.

A return spring 12 is interposed between the driven gear 73 and the body 2. The return spring 12 is composed of a coil spring or the like, and urges the valve shaft 5 toward the fully closed position of the valve body 4. As a result, when the motor 6 cannot be energized for some reason, the valve body 4 can be swung quickly to the fully closed position by the urging force of the return spring 12 to bring the engine into an idling state.

A cover 13 is attached to the body 2 so as to cover the reduction gear mechanism 7,
And the airtightness of the motor 6 is maintained.

In the throttle body 1 according to the embodiment of the present invention described above, a foreign matter generated in the fitting portion between the driven gear 73 and the fixed shaft 11, for example, abrasion powder of the driven gear 73, is generated. Alternatively, a spiral groove 73d is provided on the inner peripheral surface of the center hole 73c of the driven gear 73 as a space in which foreign matter that has entered the fitting portion from the outside can be retained. As a result, when the inner peripheral surface of the driven gear 73 is worn and abrasion powder is generated during operation of the throttle body 1, or a fine foreign substance enters the fitting portion between the driven gear 73 and the fixed shaft 11 from the outside. In this case, these foreign substances are removed from the groove 7 described above.
By staying in 3d, it is possible to prevent staying in the contact portion between the inner peripheral surface of the central hole 73c and the fixed shaft 11 and to continuously maintain the smooth rotation of the driven gear 73.

Since the groove 73d provided on the inner peripheral surface of the center hole 73c of the driven gear 73 has a spiral shape, the groove 73d is formed at the same time when the driven gear 73 is molded with resin or the like. It is possible to easily separate the driven gear 73 and the molding die (not shown) by relatively rotating them.

In the throttle body 1 according to the embodiment of the present invention, the cross-sectional shape of the groove 73d is substantially semicircular as shown in FIG. 2, but other shapes, for example, as shown in FIG. It may be triangular or rectangular as shown in FIG.

FIG. 5 shows a sectional view of another modified example of the driven gear 73 in the throttle body 1 according to the embodiment of the present invention. 6 is a sectional view taken along line VI-VI in FIG. In another modification, a linear groove 73e extending in the axial direction of the center hole 73c is provided on the inner peripheral surface of the center hole 73c of the driven gear 73 as a space for retaining foreign matter. In another modification, when the inner peripheral surface of the driven gear 73 is worn and abrasion powder is generated during the operation of the throttle body 1, or when a fine foreign substance is externally fitted to the driven gear 73 and the fixed shaft 11. When the foreign matter enters the central portion, the foreign matter is retained in the groove 73e, so that the central hole 7
It is possible to prevent the driven gear 73 from smoothly staying at the contact portion between the inner peripheral surface of 3c and the fixed shaft 11, and to continuously maintain the smooth rotation of the driven gear 73.

Further, since the groove 73e is formed in a straight line extending in the axial direction of the center hole 73c, the groove 73e is formed at the same time when the driven gear 73 is molded with resin or the like, and at the same time as the driven gear 73. The mold (not shown) can be easily separated. In addition, in another modification, the groove 7
Although the cross-sectional shape of 3e is a substantially semicircular shape as shown in FIG. 6, it may be another shape, for example, a triangular shape as shown in FIG. 7 or a rectangular shape as shown in FIG.
In this case, the number of the grooves 73e may be one or plural.

9, 10, and 11 are perspective external views of other modified examples of the throttle body 1 according to the embodiment of the present invention. In these other modified examples, a space where foreign matter generated in the fitting portion between the driven gear 73 and the fixed shaft 11, for example, abrasion powder of the driven gear 73 or foreign matter that has entered the fitting portion from the outside can be retained. It is formed on the outer peripheral surface of the fixed shaft 11. That is, in another modification shown in FIG. 9, a spiral groove 11 a is provided on the outer peripheral surface of the fixed shaft 11. In another modification shown in FIG. 10, an annular groove 11 is provided as a groove provided on the outer peripheral surface of the fixed shaft 11 in the circumferential direction.
b is provided. Further, in another modified example shown in FIG. 11, a groove 11c, which is a groove provided in the axial direction of the fixed shaft 11, is provided on the outer peripheral surface of the fixed shaft 11. 9 and 1
0, the other modification of the throttle body 1 according to the embodiment of the present invention shown in FIG.
When the inner peripheral surface of the driven gear 73 is worn during operation and wear powder is generated, or fine foreign matter is externally applied to the driven gear 7
3 enters the fitting portion between the fixed shaft 11 and the fixed shaft 11, these foreign substances are removed from the grooves 11a, 11b, or 11c.
By being retained inside, it is prevented from staying at the contact portion between the inner peripheral surface of the center hole 73c and the fixed shaft 11, and the driven gear 7
The smooth rotation of 3 can be continuously maintained.

In FIGS. 10 and 11, the groove 11
The number of the grooves b and the number of the grooves 11c are each one, but a plurality of grooves may be provided.

In the above-described throttle valve device 1 according to the embodiment of the present invention, its modification and other modifications, the number of driven gears 73 is one, but two or more driven gears 73 may be provided. good. Even in that case, each driven gear 7
3, the above-mentioned groove 73d or groove 73, which is a space for retaining foreign matter such as abrasion powder on the inner peripheral surface of the center hole 73c.
By providing e, the smooth rotation of the driven gear 73 can be continuously maintained.

[Brief description of drawings]

FIG. 1 is a throttle body 1 according to an embodiment of the present invention.
FIG.

FIG. 2 is a throttle body 1 according to an embodiment of the present invention.
6 is a sectional view of a driven gear 73 of FIG.

FIG. 3 is a throttle body 1 according to an embodiment of the present invention.
It is sectional drawing of the modification.

FIG. 4 is a throttle body 1 according to an embodiment of the present invention.
It is sectional drawing of the other modified example.

FIG. 5 is a throttle body 1 according to an embodiment of the present invention.
It is sectional drawing of the other modified example.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a throttle body 1 according to an embodiment of the present invention.
It is sectional drawing of the other modified example.

FIG. 8 is a throttle body 1 according to an embodiment of the present invention.
It is sectional drawing of the other modified example.

FIG. 9 is a throttle body 1 according to an embodiment of the present invention.
It is sectional drawing of the other modified example.

FIG. 10 is a sectional view of another modification of the throttle body 1 according to the embodiment of the present invention.

FIG. 11 is a sectional view of another modification of the throttle body 1 according to the embodiment of the present invention.

[Explanation of symbols]

1 Throttle body (throttle valve device) 2 body 3 air passages 4 valve body 5 valve shaft 6 motor 6a Output shaft 7 Gear reduction mechanism 71 first gear 72 Second gear 73 Driven gear 73c central hole 73d groove (space) 73e groove (space) 11 fixed axis 11a groove (space) 11b groove (space) 11c groove (space)

Claims (5)

[Claims] 1. A main body, an air passage provided in the main body, a valve shaft rotatably supported by the main body, the valve shaft extending in a direction substantially orthogonal to an air flow direction of the air passage, and the inside of the air passage. A valve body fixed to the valve shaft and rotating together with the valve shaft to open and close the air passage; a motor provided in the main body for rotating the valve shaft; and a rotational force of the motor. A reduction gear mechanism for transmitting to the valve shaft, wherein the reduction gear mechanism includes a first gear provided on the output shaft of the motor, a second gear provided on the valve shaft, and the first gear. A driven gear that is rotationally driven by a gear to rotationally drive the second gear, the driven gear having a center hole that is rotatably fitted to a fixed shaft provided in the main body. In the valve device, the driven gear and the fixed shaft The fitting portion, a throttle valve device and a space to allow retention of foreign matter entering the foreign matter or the fitting portion generated in the fitting portion. 2. The throttle valve device according to claim 1, wherein the space is a spiral groove provided on an inner peripheral surface of the center hole of the driven gear. 3. The throttle valve device according to claim 1, wherein the space is a groove provided in an inner peripheral surface of the center hole of the driven gear in an axial direction of the center hole. 4. The throttle valve device according to claim 1, wherein the space is a circumferential groove of the fixed shaft or a spiral groove provided on the outer peripheral surface of the fixed shaft. 5. The throttle valve device according to claim 1, wherein the space is a groove provided on an outer peripheral surface of the fixed shaft in an axial direction of the fixed shaft.