JPH10176552A - Throttle body - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a throttle body that enables highly accurate intake air flow control even if the outer peripheral side is deformed. A throttle body (2) is integrally formed of a resin material, and an outer cylinder housing (10) and an inner cylinder housing (20) are connected by a connecting portion (30) at an opening end.
The cylindrical portion 11 of the outer cylinder housing 10 and the inner cylinder housing 20
And a clearance 60 is formed in the radial direction between them.
Since the inner cylinder housing 20 can be formed into a simple cylindrical shape, the inner cylinder housing 20 can be molded with high accuracy, and even if the throttle body 2 expands and contracts due to a temperature change, the inner cylinder housing 20 expands and contracts according to the shape of the throttle valve. I do. Furthermore, even if the outer cylinder housing 10 is deformed, the inner cylinder housing 20 can be prevented from being deformed. Therefore,
Since the clearance formed between the inner cylinder housing 20 and the throttle valve can be maintained with high precision, the intake passage 20
The intake flow rate of 0 can be controlled with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle body forming an intake passage.

[0002]

2. Description of the Related Art In recent years, there has been known a type in which 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. Further, embedding a metal supporting member is against the demand for reducing the weight and cost of the throttle body.

An object of the present invention is to provide a throttle body capable of controlling intake air flow with high accuracy even when the outer peripheral side is deformed.

[0007]

According to the throttle body of the present invention, the outer member is formed of a resin material, and at least a portion of the inner member surrounding the valve member is separated from the outer member by the resin material. Even if the outer member is deformed during or after molding,
It is possible to prevent the deformation of the outer member from acting as a factor for deforming the inner member. Even if the outer member has a complicated shape having a holding portion or the like, since the inner member can be formed into a simple shape that surrounds the valve member and forms an intake passage, deformation during forming of the inner member can be reduced. The inside member can be formed with high precision by suppressing the above. Furthermore, since at least a portion of the inner member surrounding the valve member is separated from the outer member and the inner member can be formed into a simple shape, even if the throttle body expands and contracts due to a temperature change, the inner member corresponds to the shape of the valve member. Expands and contracts.

As described above, the clearance formed between the inner member and the valve member can be controlled with high accuracy so as to obtain a predetermined intake air flow characteristic in accordance with the opening degree of the valve member. According to the throttle body described in claim 3 of the present invention,
Since the outer member and the inner member are integrally formed of a resin material, the process of assembling the throttle body can be omitted in the case where the outer member and the inner member are formed separately, so that the number of manufacturing steps is reduced and the manufacturing cost is reduced. descend.

According to the throttle body of the fourth aspect of the present invention, since the outer member and the inner member are formed separately from the resin material, the inner member can be raised regardless of the deformation of the outer member during molding. Can be molded with high precision. According to the throttle body of the fifth aspect of the present invention, since the inner member is connected to the outer member so as to be movable in the radial direction with respect to the outer member by the flange portion provided on the inner member, the outer member is formed at the time of molding or after molding. Or, even if the inner member is deformed, the position of the inner member with respect to the outer member can be easily adjusted. Therefore, the clearance formed between the inner member and the valve member can be controlled with high accuracy so as to obtain a predetermined intake flow rate characteristic in accordance with the opening degree of the valve member.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIG. 1 shows a throttle body according to a first embodiment of the present invention. The throttle body 2 is integrally formed of a resin material, and the outer cylinder housing 10 and the inner cylinder housing 20 are connected to each other by a connection portion 30 at their opening side ends. The outer cylinder housing 10 and the inner cylinder housing 20 respectively represent the “outer member” and the “inner member” described in the claims. Due to the inner walls of the outer cylinder housing 10 and the inner cylinder housing 20, the intake passage 2
00 is formed.

The outer cylinder housing 10 comprises a cylindrical portion 11 and a holding portion 12 for supporting a throttle shaft 41 described later. The holding portion 12 protrudes radially outward from the cylindrical portion 11, and has a through hole 12a through which the throttle shaft 41 is inserted.
Are formed through the holding portion 12 on both radial sides of the intake passage 200. The fixing portion 31 shown in FIG. 2 projects radially outward from four corners of the cylindrical portion 11. The fixing portion 31 has a bolt hole 31a formed therein, and the throttle valve control device 1 is fixed to an intake pipe (not shown) by a bolt (not shown) inserted into the bolt hole 31a.

As shown in FIG.
Is formed in a simple cylindrical shape without an uneven portion. At two positions corresponding to the holding portions 12 of the inner cylinder housing 20, two through holes 20a through which the throttle shaft 41 is inserted are provided. Since the inner diameter of the cylindrical portion 11 of the outer cylinder housing 10 is set to be larger than the outer diameter of the inner cylinder housing 20, a clearance 60 is formed in the radial direction between the cylindrical portion 11 and the inner cylinder housing 20.

The through holes 12a and 20a provided in the outer cylinder housing 10 and the inner cylinder housing 20
It is formed so as to have a high degree of linearity on the diameter of the element and not to cause misalignment. Further, in order to control the intake flow rate with high accuracy by a clearance formed by the inner wall of the inner cylinder housing 20 and the throttle valve 40 as a valve member shown in FIG. In order to control the intake flow rate with high accuracy in a range where the opening degree is small, the inner cylinder housing 20 is formed with a high degree of dimensional accuracy in roundness and inner diameter. Since the inner cylinder housing 20 is formed in a simple cylindrical shape, the through hole 20a, roundness and inner diameter can be formed with high dimensional accuracy.

The dimensional accuracy of the outer cylinder housing 10 and the inner cylinder housing 20 other than those described above may be sufficient as long as the clearance 60 is formed and the inner cylinder housing 20 can be arranged in the outer cylinder housing 10. No need. FIG. 2 shows a throttle valve control device 1 in which other components are assembled to the throttle body 2. 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.

In the first embodiment, the throttle body 2 is integrally formed of a resin material. However, the outer cylinder housing 10 and the inner cylinder housing 20 forming the throttle body 2 are connected to each other at their open ends. A cylindrical clearance 60 is formed in the radial direction between the outer cylinder housing 10 and the inner cylinder housing 20 in the axial direction of the inner cylinder housing 20 surrounding the throttle valve 40. Therefore, even if the shape of the outer cylinder housing 10 becomes complicated, the inner cylinder housing 20 surrounding the throttle valve 40 is formed.
Can be formed into a simple cylindrical shape. Thereby, the inner cylinder housing 20 can be molded with high dimensional accuracy, and even if the throttle body 2 expands and contracts due to a temperature change after the molding of the throttle body, the inner cylinder housing 20 can be formed by the throttle valve 4.
Since it expands and contracts uniformly while maintaining a perfect circle corresponding to the shape of 0, there is no variation in the clearance formed with the throttle valve 40.

Since the clearance 60 is formed in the radial direction between the outer cylinder housing 10 and the inner cylinder housing 20, even if the outer cylinder housing 10 is deformed during molding, the inner cylinder housing 20 is deformed by this deformation. Can be prevented. Furthermore, even when the outer cylinder housing 10 is deformed by the tightening force of the bolt when the throttle valve control device 1 is assembled to the engine, the deformation of the inner cylinder housing 20 due to this deformation can be prevented. Furthermore, even after the outer cylinder housing 10 is deformed due to a temperature change or the like after the throttle valve control device 1 is assembled to the engine, this deformation can be prevented from acting as a factor for deforming the inner cylinder housing 20.

Further, since the throttle body 2 can be integrally formed, the number of manufacturing steps is reduced and the manufacturing cost is reduced. (Second Embodiment) FIG. 3 shows a throttle body according to a second embodiment of the present invention. Components substantially the same as those in the first embodiment are denoted by the same reference numerals.

In the throttle body 3 of the second embodiment, the connecting portion 30 connects the opening end of the inner cylinder housing 20 and the inner wall of the cylindrical portion 11 of the outer cylinder housing 10 axially inward from both ends on the opening side. Are connected by In the second embodiment, as in the first embodiment, the inner cylinder housing 20 is formed in a simple cylindrical shape, and a clearance 60 is formed between the outer cylinder housing 10 and the inner cylinder housing 20. Therefore, the inner cylinder housing 20 can be molded with high precision, and even if the outer cylinder housing 10 is deformed, this deformation can be prevented from acting as a factor for deforming the inner cylinder housing 20. Further, since the throttle body 3 can be integrally formed, the number of manufacturing steps is reduced and the manufacturing cost is reduced.

(Third Embodiment) FIG. 4 shows a throttle body according to a third embodiment of the present invention. Components substantially the same as those in the first embodiment are denoted by the same reference numerals. Throttle body 5
Consists of 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 by an annular projection 13a and a flange 2
2 and is fixed by an adhesive or heat welding at the contact position with the outer cylinder housing 100 and the inner cylinder housing 11.
0 in a state shown in FIG. 4 with the outer cylinder housing 100 and the inner cylinder housing 110 connected thereto.
Are formed.

The outer cylinder housing 100 includes a cylindrical portion 11,
And a holding portion 12 for supporting the throttle shaft. The holding portion 12 protrudes radially outward from the cylindrical portion 11, and a through hole 12 a for inserting the throttle shaft is provided in the intake passage 20.
0 is formed to penetrate the holding portion 12 on both sides in the radial direction. An annular projection 13 a is formed along the circumferential direction of one opening end 13 of the cylindrical portion 11.

The inner cylinder housing 110 is composed of a simple cylindrical portion 21 having 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. Become. Two through-holes 21a are provided at positions corresponding to the holding portions 12 of the cylindrical portion 21 to penetrate the throttle shaft. The inner cylinder housing 110 is formed with high precision in roundness and inner diameter in order to control the clearance formed with the throttle valve with high precision.

Since the inner cylinder housing 110 is formed separately from the outer cylinder housing 100 having a complicated shape,
The portion of the inner cylinder housing 110 surrounding the throttle valve 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, roundness, and inner diameter of the inner cylinder housing 110 can be molded with high accuracy.

In a state where the outer cylinder housing 100 and the inner cylinder housing 110 are connected to each other, the through holes 12a and 21a are located at a high linearity on the diameter of the intake passage 200, and the outer cylinder housing is prevented from being misaligned. 100 and the inner cylinder housing 110 are molded. Through hole 12 described above
a, 21a, outer cylinder housing 100 and inner cylinder housing 11 other than roundness and inner diameter of inner cylinder housing 110
The dimensional accuracy of 0 only needs to be such that the inner cylinder housing 110 can be accommodated in the outer cylinder housing 100 and the clearance 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. As a result, in a state where the outer cylinder housing 100 and the inner cylinder housing 110 are assembled as shown in FIG.
Is formed, and a clearance 61 is formed in the radial direction and the axial direction between the opening end 13 and the flange portion 22. Therefore, in a state before the annular projection 13a and the flange portion 22 are bonded and fixed, the outer cylinder housing 100
The inner cylinder housing 110 housed inside the outer cylinder housing 1
00 can be moved in the radial direction. 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.

According to the third embodiment, the outer cylinder housing 10
0 and the inner cylinder housing 110 are 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 with respect to 0, the position of the inner cylinder housing 110 with respect to the outer cylinder housing 100 can be adjusted in the radial direction when configuring the throttle body 5. Therefore, the throttle valve can be arranged 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, so that the clearance formed by the inner wall of the cylindrical portion 21 and the throttle valve is provided. Can be controlled to have a predetermined intake flow rate 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.

In the third embodiment, the outer cylinder housing 10
0 and the inner cylinder housing 110 are molded separately,
The inner cylinder housing 110 can be molded with higher precision than when integrally molded. In the third embodiment, the position of the throttle valve 40 in the intake passage 200 formed by the cylindrical portion 21 is adjusted by moving the inner cylinder housing 110 in the radial direction to adjust the position of the inner cylinder housing 110 with respect to the outer cylinder housing 100. 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 so that the throttle shaft can be inserted through the diameter of the intake passage so that the throttle shaft can be inserted. There is no need to adjust the axial position of the through hole with high accuracy. Therefore, the manufacture of each housing is facilitated, and the manufacturing cost can be reduced.

In the third embodiment, the opening end 13 and the flange 22 are fixed by an adhesive or heat welding. However, the throttle valve control device is fixed to the engine depending on the structure of the connecting portion. When the throttle body is deformed and the throttle valve cannot be accommodated at a predetermined position in the intake passage after the above, 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.

Further, in the third embodiment, the flange portion 22 as a connecting portion is formed integrally with the inner cylinder housing 110. However, the connecting portion may be provided separately from the outer housing and the inner housing. In the above-mentioned plurality of embodiments showing the embodiment of the present invention, the outer cylinder housing and the inner cylinder housing are separated from each other to form a clearance, so that the throttle body is fixed to the engine, temperature change, etc. Accordingly, even if the outer cylinder housing is deformed, the deformation of the outer cylinder housing can be prevented from acting as a factor for deforming at least a portion of the inner cylinder housing surrounding the throttle valve. Further, since at least a portion of the inner cylinder housing surrounding the throttle valve can be formed into a simple cylindrical shape, the inner cylinder housing can be formed with high precision.
Furthermore, since a clearance is formed between the outer cylinder housing and the inner cylinder housing, and at least a portion of the inner cylinder housing surrounding the throttle valve can be formed in a simple shape, even if the throttle body 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, since the clearance formed between the inner cylinder housing and the throttle valve can be maintained with high accuracy, the intake air flow rate in the intake passage can be controlled with high accuracy.

[Brief description of the drawings]

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

FIG. 2 is a partial sectional view showing a throttle valve control device according to the first embodiment.

FIG. 3 is a sectional view showing a throttle body according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a throttle body according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Throttle valve control device 2, 3, 5 Throttle body 10 Outer cylinder housing (outer member) 11 Cylindrical part 12 Holding part 20 Inner cylinder housing (inner member) 21 Cylindrical part 22 Flange part (connection part) 40 Throttle valve 41 Throttle shaft 60 clearance (gap) 100 outer cylinder housing (outer member) 110 inner cylinder housing (inner member)

Claims (5)

[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, and an inner member disposed on the inner periphery of the outer member, at least a portion surrounding the valve member is separated from the outer member, and is formed into a cylindrical shape with a resin material. A throttle body characterized by that. 2. The throttle body according to claim 1, wherein a gap is formed between the outer member and the inner member. 3. The throttle body according to claim 1, wherein the outer member and the inner member are integrally formed of a resin material. 4. The throttle body according to claim 1, wherein the outer member and the inner member are formed separately from a resin material. 5. 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 a connecting portion. The throttle body according to claim 4, wherein the inner member is connected to the outer member so as to be movable in a radial direction.