JPH10176551A - Throttle body and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the position of component members and to control the amount of flow of air intake with high accuracy. SOLUTION: An outer cylindrical housing 100 and an inner cylindrical housing 110 are independently formed of resin material, respectively, and are bonded to each other at the contact position of an annular projection 13a and a flange 22. A clearance 60 is formed in the radial direction between the outer cylindrical housing 100 and the inner cylindrical housing 110. Since the position of a throttle valve in an intake passage 200 can be adjusted while the inner cylindrical housing 110 is being moved in the radial direction to the outer cylindrical housing 100, the clearance formed between the inner cylinder 21 and the throttle valve is controlled with high accuracy such that it has a predetermined intake flow characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a throttle body forming an intake passage and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, it has been known that a throttle body is formed of resin in order to reduce the weight and cost of a throttle valve control device. However, since the throttle body needs to be formed into a complicated shape including irregularities such as a holding portion of the throttle shaft, a mounting portion of the opening sensor, and the like, for example, when the throttle body is integrally formed of resin, a resin flow during the molding is required. And the shape is easily deformed due to temperature change. Particularly, when the intake passage or the bearing portion of the throttle shaft which requires high dimensional accuracy is deformed, it becomes necessary to cut the deformed portion.

In order to ensure high dimensional accuracy by cutting after molding, a mold for the throttle body is formed in consideration of the deformation during molding, and the throttle body is made of a resin material using the mold. One-piece molding is also conceivable. However, when molded integrally with a resin material, the deformation of each part of the throttle body affects each other, so it is difficult to integrally mold the throttle body with a higher dimensional accuracy using a resin material in consideration of the deformation of the entire throttle body. is there.

[0004] Even if the deformed portion of the throttle body is cut after forming, the intake passage and the bearing may be deformed by the tightening force when the throttle body is fixed to the intake pipe with bolts or the like. JP-A-3-18632
As disclosed in Japanese Patent Application Laid-Open Publication No. H11-260, the throttle body is formed by embedding a metal support member processed with high dimensional accuracy in the inner wall of a resin wall surrounding the throttle valve, thereby surrounding the throttle valve and the throttle valve. It is conceivable to control the clearance formed with the support member with high accuracy.

[0005]

However, in the case where the metal support member is embedded in the inner wall of the wall of the throttle body, the metal support member is in close contact with the wall due to the deformation of the resin wall. However, there is a problem that the roundness of the intake passage is reduced because of the possibility of deformation. Further, since the bearing portion of the wall supporting the throttle shaft may be deformed by the deformation of the resin wall, it is necessary to cut the deformed portion.

An object of the present invention is to provide a throttle body capable of adjusting the position of a constituent member and performing highly accurate intake air flow control. It is another object of the present invention to provide a method of manufacturing a throttle body that enables the position of a component to be adjusted and enables highly accurate intake air flow control.

[0007]

According to a first aspect of the present invention, there is provided a throttle body comprising: an outer member formed of a resin material; and an inner member disposed on the inner periphery of the outer member. With the provision of the connecting portion capable of adjusting the position of the inner member with respect to the outer member, the clearance formed between the inner member and the valve member can be controlled with high precision so as to have a predetermined intake air flow characteristic.

Further, since the adjustment of the accommodation position of the valve member is easier than in the case of cutting the outer member and the inner member, the man-hour for manufacturing the throttle valve control device is reduced, and the manufacturing cost is reduced. Further, since the outer member and the inner member are formed separately, even if the outer member is deformed during molding, the deformation does not act as a factor for deforming the inner member. Further, even if the outer member has a complicated shape for providing the holding portion of the valve member, at least a portion surrounding the valve member of the inner member can be formed in a simple shape, so that the inner member has a high size. Can be molded with precision.

Further, depending on the structure of the connecting portion, when the throttle body is fixed to the engine, or when the throttle body expands and contracts due to a temperature change or the like and the valve member cannot be housed at a predetermined position in the intake passage, the inner member relative to the outer member may not be accommodated. By adjusting the position, the valve member can be returned to a predetermined position in the intake passage. Therefore, highly accurate control of the intake flow rate can be maintained.

According to the throttle body of the second aspect of the present invention, a gap is provided between the outer member and the inner member so that the position of the inner member relative to the outer member can be adjusted. Even if the outer member is deformed after the connection of the inner member, the deformation can be prevented from acting as a factor for deforming the inner member. According to the method for manufacturing a throttle body according to the fourth aspect of the present invention, the inner member is moved by moving the inner member relative to the outer member in accordance with the housing position of the valve member, and then connecting the outer member and the inner member. It is possible to control the clearance formed by the valve member and the valve member with high accuracy so as to have a predetermined intake flow rate characteristic.

Further, since the adjustment of the accommodation position of the valve member is easier than in the case of cutting the outer member and the inner member, the man-hour for manufacturing the throttle valve control device is reduced, and the manufacturing cost is reduced. Further, since the outer member and the inner member are formed separately, even if the outer member is deformed during molding, the deformation does not act as a factor for deforming the inner member. Further, even if the outer member has a complicated shape due to the provision of the holding portion of the valve member, at least a portion surrounding the valve member of the inner member can be formed into a simple shape. Therefore, the inner member can be formed with high dimensional accuracy.

Further, depending on the structure of the connecting portion, when the throttle body is fixed to the engine, or when the throttle body expands and contracts due to a temperature change or the like and the valve member cannot be housed at a predetermined position in the intake passage, the inner member relative to the outer member may not be accommodated. By adjusting the position, the valve member can be returned to a predetermined position in the intake passage. Therefore, highly accurate control of the intake flow rate can be maintained.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a throttle body according to an embodiment of the present invention. FIG. 4 shows the throttle valve control device 4. As shown in FIG. 1, the throttle body 5 is an outer cylinder housing 100 as an outer member.
And an inner cylinder housing 110 as an inner member.
The outer cylinder housing 100 and the inner cylinder housing 110 are formed separately from a resin material. The outer cylinder housing 100 and the inner cylinder housing 110 are formed as annular projections 13.
1 and the inner wall of the inner cylinder housing 110 in a state shown in FIG. 1 in which the outer cylinder housing 100 and the inner cylinder housing 110 are connected to each other and fixed by an adhesive or heat welding at a contact position between the outer cylinder housing 100 and the flange portion 22. Defines an intake passage 200.

The outer cylinder housing 100 includes a cylindrical portion 11,
The holding section 12 supports a throttle shaft 41 described later. The holding portion 12 projects radially outward from the cylindrical portion 11, and has a through hole 12 through which the throttle shaft 41 is inserted.
a is formed penetrating the holding part 12 on both radial sides of the intake passage 200. One open end 13 of the cylindrical portion 11
An annular protrusion 13a is formed along the circumferential direction. The fixing portion 31 shown in FIG. 4 projects radially outward from four corners of the opening-side end portion 13. A bolt hole 31a is provided in the fixing portion 31.
The throttle valve control device 4 is fixed to an intake pipe (not shown) by a bolt (not shown) inserted into the bolt hole 31a.

[0015] As shown in FIG.
Consists of a cylindrical portion 21 having a simple shape with no concave and convex portions, and an annular flange portion 22 as a connecting portion extending radially outward from one open end of the cylindrical portion 21. Cylindrical part 2
At two positions corresponding to the one holding portion 12, two through holes 21a through which the throttle shaft 41 is inserted are provided. The inner cylinder housing 110 is formed with high precision in roundness and inside diameter in order to control the clearance formed with the throttle valve 40 with high precision.

Since the inner cylinder housing 110 is formed separately from the outer cylinder housing 100 having a complicated shape,
A portion of the inner cylinder housing 110 surrounding the throttle valve 40 can be formed as a simple cylindrical portion 21. Therefore, regardless of the deformation of the outer cylinder housing 100 at the time of molding, the through-hole 21a, the roundness, and the inner diameter of the inner cylinder housing 110 can be molded with high accuracy.

In the outer cylinder housing 100 shown in FIG. 2, the axial distances L ₁ from the tip of the annular projection 13a of the outer cylinder housing 100 to the center of the through hole 12a are formed to be equal to each other. In the cylindrical housing 110 inner 3, the axial distance L ₂ from the surface facing the open end 13 of the flange portion 22 to the center of the through hole 21a is formed to be equal to each other. Further, as described above, the through-holes 12a, 21a are connected with the outer cylinder housing 100 and the inner cylinder housing 110 shown in FIG.
a is located at a high degree of linearity on the diameter of the intake passage 200, and the outer cylinder housing 100 and the inner cylinder housing 110 are formed so that L ₁ = L ₂ so as not to cause misalignment.

The dimensional accuracy of the outer cylinder housing 100 and the inner cylinder housing 110 other than the above-described through-holes 12a and 21a, the roundness of the inner cylinder housing 110 and the inner diameter is determined by accommodating the inner cylinder housing 110 in the outer cylinder housing 100 and the clearance. It is sufficient that 60 can be secured, and it is not necessary to mold with high precision. The inner diameter of the outer cylinder housing 100 is set larger than the outer diameter of the inner cylinder housing 110, and the inner diameter of the opening-side end 13 is set larger than the outer diameter of the flange 22. Thus, a clearance 60 is formed in the radial direction between the cylindrical portion 11 and the cylindrical portion 21 in a state shown in FIG. 1 in which the outer cylinder housing 100 and the inner cylinder housing 110 are assembled, and the opening side end 13 and the flange are formed. Part 2
2, a clearance 61 is formed in the radial direction and the axial direction. Therefore, before the annular projection 13a and the flange portion 22 are bonded and fixed, the inner cylinder housing 110 housed in the outer cylinder housing 100 can be moved in the radial direction with respect to the outer cylinder housing 100. Further, in a state where the annular projection 13a and the flange portion 22 are bonded and fixed to each other and the outer cylinder housing 100 and the inner cylinder housing 110 are connected, even if the outer cylinder housing 110 is deformed, this deformation causes the inner cylinder housing 110 to be deformed. Can be prevented.

FIG. 4 shows a throttle valve control device in which other components are assembled to the throttle body 5. The throttle valve 40 is sandwiched between the throttle shafts 41 and is fixed to the throttle shaft 41 with screws 42. A bearing 50 is mounted on the inner wall of the holding part 12, and an oil seal 51 is mounted on the end of the bearing 50 on the throttle shaft end side. The throttle shaft 41 is rotatably supported by the bearing 50.

Next, a method of manufacturing the throttle valve control device 4 will be described. (1) an outer cylinder housing 100 forming the distance L ₁ with high dimensional accuracy. Other molding accuracy, for example, if the inner diameter of the cylindrical portion 11 is formed so as to be larger than the outer diameter of the cylindrical portion 21 so that the inner cylindrical housing 110 can be moved in the radial direction when the inner cylindrical housing 110 is accommodated. Does not require high dimensional accuracy. After the outer cylinder housing 100 is formed, the bearing 50 and the oil seal 51 are pressed into the holding portion 12.

The inner cylinder housing 110 is formed so that the distance L ₂ and the inner diameter of the cylindrical portion 21 accommodating the throttle valve 40 become a perfect circle with high dimensional accuracy. (2) Insert the inner cylinder housing 110 into the outer cylinder housing 100, and insert the throttle shaft 41 into the through holes 12a and 21a. The throttle valve 40 is sandwiched between the throttle shafts 41 and lightly fixed with screws 42.

(3) Light is irradiated from below in FIG. 1 and the inner cylinder housing 110 is moved in the radial direction so that the clearance between the throttle valve 40 and the inner wall of the cylindrical portion 21 becomes uniform when the throttle valve 40 is fully closed. Move to When the position of the inner cylinder housing 110 is determined, the opening side end 1 of the outer cylinder housing 100 is determined.
3 and the flange portion 22 of the inner cylinder housing 110 are fixed with an adhesive. Instead of fixing with an adhesive, the opening side end 1
3 and the flange portion 22 may be thermally welded.

(4) Light is emitted from below in FIG. 1 and screws 42 are tightened so that the clearance between the throttle valve 40 and the inner wall of the cylindrical portion 21 is uniform when the throttle valve 40 is fully closed. The throttle valve 40 is fixed to the shaft 41. In this manner, while adjusting the position of the inner cylinder housing 110 with respect to the outer cylinder housing 100, the throttle valve 4
0 in a predetermined position, the inner cylinder housing 1
The clearance formed by the ten cylindrical portions 21 and the throttle valve 40 can be controlled with high precision so as to obtain predetermined intake air flow characteristics.

The throttle valve control device 4 assembled as described in (1) to (4) is inserted into the bolt hole 31a by a bolt, and is tightened and fixed to an intake pipe (not shown). The outer cylinder housing 100 and the inner cylinder housing 110 are connected to the opening end 1.
3 and the flange portion 22 are merely connected, and the cylindrical portion 21 surrounding the throttle valve 40 and the outer cylinder housing 1
Since the clearance 60 is formed in the radial direction between the outer cylinder housing 10 and the outer cylinder housing 10 when tightening the bolt.
Even if 0 is deformed, the deformation prevents the cylindrical portion 21 from being deformed. Therefore, the clearance formed between the cylindrical portion 21 and the throttle valve 40 can be maintained with high accuracy, and the intake flow rate can be controlled with high accuracy by the throttle valve control device 4.

Further, even if the throttle body 5 expands and contracts due to a temperature change after the throttle valve controller 4 is fixed to the intake pipe, the cylindrical portion 21 of the inner cylinder housing 110 has a simple shape and the cylinder of the outer cylinder housing 100 has a simple shape. Clearance 6 between portion 11 and cylindrical portion 21 of inner cylinder housing 110
Since 0 is formed, the inner cylinder housing 110 expands and contracts uniformly while maintaining a perfect circle corresponding to the shape of the throttle valve 40. Therefore, there is no variation in the clearance formed between the throttle valve 40 and the throttle valve 40.

A flange 22 is formed at an end of the inner cylinder housing 110 connected to the intake pipe, and the flange 22 abuts on the intake pipe in the circumferential direction, so that the throttle body 5 and the intake pipe are formed. Air can be prevented from leaking out from the connection portion. According to the above embodiment showing the embodiment of the present invention described above, the outer cylinder housing 100
And the inner cylinder housing 110 is formed separately, and the inner diameter of the outer cylinder housing 100 is formed to be larger than the outer diameter of the inner cylinder housing 110.
By making the inner cylinder housing 110 movable in the radial direction, the position of the inner cylinder housing 110 with respect to the outer cylinder housing 100 can be adjusted in the radial direction when the throttle body 5 is constructed. Therefore, the throttle valve 40 can be disposed at a predetermined position of the intake passage 200 formed by the cylindrical portion 21 without cutting the outer cylinder housing 100 or the inner cylinder housing 110.
Can be controlled so as to have a predetermined intake air flow characteristic. In particular, the intake air flow rate can be controlled with high accuracy in a range where the throttle opening is small from the fully closed position of the throttle valve 40.

Further, since the outer cylinder housing 100 and the inner cylinder housing 110 are molded separately, the inner cylinder housing 110 can be molded with higher precision than when integrally molded. Further, according to the present embodiment, the outer cylinder housing 1
00 and the inner cylinder housing 110 and the clearance 60 is formed, so that the outer cylinder housing 10 is fixed when the throttle body 5 is fixed to the engine or when the temperature changes.
Even if 0 is deformed, the deformation of the outer cylinder housing 100 can be prevented from acting as a factor for deforming at least a portion of the inner cylinder housing 110 surrounding the throttle valve 40. Further, since at least a portion of the inner cylinder housing 110 surrounding the throttle valve 40 can be formed into a simple cylindrical shape, the inner cylinder housing 110 can be formed with high precision. Further, a clearance 60 is formed between the outer cylinder housing 100 and the inner cylinder housing 100, and at least the throttle valve 40 of the inner cylinder housing 110 is provided.
Can be formed into a simple shape, so that even if the throttle body 5 expands and contracts due to a temperature change, the inner cylinder housing 110 expands and contracts according to the shape of the throttle valve 40. As described above, the inner cylinder housing 110
Since the clearance formed between the throttle valve and the throttle valve 40 can be maintained with high precision, the intake flow rate in the intake passage can be controlled with high precision.

In this embodiment, both the outer cylinder housing 100 and the inner cylinder housing 110 are formed of resin. However, the outer cylinder housing 100 may be formed of resin, and the inner cylinder housing may be formed of metal such as aluminum or brass. It is possible. In the present embodiment, the position of the inner cylinder housing 110 with respect to the outer cylinder housing 100 is adjusted by moving the inner cylinder housing 110 in the radial direction, and the position of the throttle valve 40 in the intake passage 200 formed by the cylindrical portion 21 is adjusted. However, depending on the structure of the connecting portion, the inner cylinder housing can also be movable in the axial direction. In this case, it is necessary to align the axial positions of the two housings provided in both housings so that the throttle shafts can be inserted through the diameter of the intake passage.
There is no need to adjust the axial position of the through holes between the housings with high precision. Therefore, the manufacture of each housing is facilitated, and the manufacturing cost can be reduced.

In this embodiment, the opening end 13 and the flange 22 are fixed by an adhesive or heat welding. However, depending on the structure of the connecting portion, the throttle valve control device is fixed to the engine. If the throttle body is later deformed and the throttle valve cannot be accommodated at a predetermined position in the intake passage, the position of the inner cylinder housing with respect to the outer cylinder housing can be adjusted to return the throttle valve to the predetermined position in the intake passage.

In this embodiment, the flange portion 22 as a connecting portion is formed integrally with the inner cylinder housing 110.
It is also possible to provide a connecting part separately from the outer housing and the inner cylinder housing.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view showing the outer cylinder housing of the present embodiment.

FIG. 3 is a cross-sectional view showing the inner cylinder housing of the present embodiment.

FIG. 4 is a partial sectional view showing a throttle valve control device according to the embodiment.

[Explanation of symbols]

 Reference Signs List 4 throttle valve control device 5 throttle body 11 cylindrical part 12 holding part 21 cylindrical part 22 flange part (connection part) 40 throttle valve 41 throttle shaft 100 outer cylinder housing (outer member) 110 inner cylinder housing (inner member)

Claims (4)

[Claims] 1. A throttle body which forms an intake passage and accommodates a valve member for adjusting an intake flow rate in the intake passage in the intake passage, the throttle body having a holding portion for supporting the valve member, and made of a resin material. A molded outer member, disposed on the inner periphery of the outer member separately from the outer member,
A throttle body, comprising: an inner member surrounding the valve member; and a connecting portion connecting the inner member and the outer member so that the position of the inner member with respect to the outer member can be adjusted. 2. The throttle body according to claim 1, wherein a gap is formed between the outer member and the inner member so as to adjust a position of the inner member with respect to the outer member. 3. The outer member and the inner member are formed in a cylindrical shape extending in the axial direction of the intake passage, and a flange portion extending radially outward is provided on the inner member as the connecting portion. The throttle body according to claim 1 or 2, wherein the inner member is connected to the outer member so as to be movable in a radial direction. 4. A method for manufacturing a throttle body in which an intake passage is formed and a valve member for adjusting an intake flow rate of the intake passage is accommodated in the intake passage, wherein a resin member having a holding portion for supporting the valve member is provided. And an inner member disposed on the inner periphery of the outer member and surrounding the valve member is formed separately, and after the outer member supports the valve member, the accommodation position of the valve member Moving the inner member with respect to the outer member to a suitable position, and connecting the outer member and the inner member.