Title of Invention

THROTTLE VALVE DEVICE

Abstract To enhance sealing performance between a throttle valve main body and a throttle body. [Solving Means] A throttle valve device includes a throttle valve main body 10 and a throttle body 8 for accommodating the throttle valve main body 10. The throttle valve main body 10 includes a shaft portion 12 and a valve portion 11. The valve portion 11 includes an elastic portion 21, which is added to the valve portion 11 through dual molding. The elastic portion 21 is extended to the shaft portion 12 to form an extension. A peripheral edge of the extension is corrugated to achieve better adhesion with the throttle body 8. The shaft portion 12 includes a large diameter part 13 and a small diameter part 14. The large diameter part 13 has a dimension larger than the valve portion 11. The small diameter part 14 has a dimension smaller than the valve portion 11. [Selected Drawing] Fig. 1
Full Text

[Name of Document] Specification
[Title of the Invention] Throttle Valve Device
[Technical Field]
[0001]
The present invention relates generally to a throttle valve device and, more specifically, to a throttle valve device including a preferred structure for improving sealing performance.
[Background Art]
[0002]
A throttle valve device is incorporated in a carburetor or an electronic control fuel injection system in order to control an output of an internal combustion engine by adjusting an amount of air-fuel mixture drawn into a combustion chamber of the internal combustion engine. A known throttle valve device includes, as disclosed in, for example, Japanese Utility Model Laid-open No. Hei 3-112542, a butterfly throttle valve main body that is journaled in a throttle chamber or a throttle body and rotated for adjusting valve opening. The throttle valve device disclosed in Japanese Utility Model Laid-open No. Hei 3-112542 uses a throttle body made of resin. Japanese Utility Model Laid-open No. Hei 4-134643, on the other hand, discloses a throttle valve

device, in which resin coating is applied or resin tape is affixed to a surface of the throttle valve so as to prevent moisture deposited on the throttle valve from being frozen.
[Patent Document 1]
Japanese Utility Model Laid-open No, Hei 3-112542 [Patent Document 2]
Japanese Utility Model Laid-open No. Hei 4-134643 [Disclosure of the Invention] [Problem to be Solved by the Invention] [0003]
Conventionally, the throttle valve main body includes a butterfly valve portion and a shaft portion which are assembled together through screwing, caulking, or a related method. Accordingly, there is a problem in that the conventional throttle valve device requires a larger number of man-hours for assembly processes because of the arrangement of the butterfly valve portion built separately from the shaft portion. In addition, variations in dimensional tolerances involved with the throttle valve main body and the throttle body result in sealing performance varying when the valve is fully closed. This makes it necessary to adjust air flow rate after the assembly processes.

Fig. 14 is a cross-sectional view showing a conventional art that exemplifies variations in sealing performance occurring from angular tolerances of the throttle body and the butterfly valve portion. A butterfly valve portion 100 is arranged so as to provide a seal by abutting on a step 120 in a throttle body 110. As can be understood from Fig. 14, variations in the step 12 0 in the throttle body 110 produce a clearance 13 0 despite the fact that the butterfly valve portion 100 has rotated to a predetermined fully closed position. [0005]
Fig. 15 is a cross-sectional view showing a conventional art that exemplifies variations in sealing performance occurring from tolerances in an axial length of the throttle body and the throttle valve main body. Fig. 15 shows only a shaft portion of the entire throttle valve main body. Referring to Fig. 15, a throttle valve main body 140 has two surfaces 150, 160, against which the throttle body 110 is set to abut. Fig. 15 shows that one (150) of the two surfaces 150, 160 abuts on the throttle body 110, while the other (160) does not abut on the throttle body 110, resulting in a clearance 170 being produced.

It is an object of the present invention to provide a throttle valve device that can not only solve the problem of incomplete sealing as described above, but also reduce the number of man-hours required for assembling the throttle valve main body.
[Means for Solving the Problem]
[0007]
To achieve the foregoing object, the present invention is applied to a throttle valve device for an internal combustion engine. The device includes a throttle valve main body and a throttle body for accommodating the throttle valve main body. A first aspect of the present invention is characterized in that the throttle valve main body includes a butterfly valve portion for opening or closing an intake path portion inside the throttle body and a shaft portion for supporting the butterfly valve portion relative to the throttle body. The butterfly valve portion is covered with an elastic portion made of an elastic material added preferably through dual molding.
[0008]
A second aspect of the present invention is characterized in that the throttle valve main body

includes a recessed portion and/or a hole, which the
elastic material can enter.
[0009]
A third aspect of the present invention is characterized in that the elastic portion is extended from the valve portion to the shaft portion to form an extension and the extension includes a corrugated peripheral edge. The throttle body includes a wall surface, on which the peripheral edge abuts. [0010]
A fourth aspect of the present invention is characterized in that the butterfly valve portion and the shaft portion are an integral structure made of resin. The shaft portion has two sections of different diameters. The first section is disposed on one side of the butterfly valve portion and has a diameter greater than the maximum dimension of the butterfly valve portion. The second section is disposed on the other side of the butterfly valve portion and has a diameter smaller than the maximum dimension of the butterfly valve portion. [0011]
A fifth aspect of the present invention is characterized in that the throttle valve main body is positioned relative to the throttle body along an axis of

the shaft portion in a condition of being loaded on one side along the axis of the shaft portion.
[Effects of the Invention]
[0012]
According to the first aspect of the present invention, the butterfly valve portion is covered with the elastic portion. This allows deformation of the elastic portion to absorb any variations in angular tolerances of valve rotation or in tolerances of a shape of the intake path in the throttle body, against which the butterfly valve portion abuts during throttle closing. Sealing performance in the throttle closed condition can therefore be enhanced. Moreover, the elastic portion can be easily added through dual molding.
[0013]
According to the second aspect of the present invention, the elastic material enters the recessed portion and/or the hole during molding. An even more positive connection can therefore be achieved between the elastic portion and the throttle valve main body.
[0014]
According to the third aspect of the present invention, the corrugated peripheral edge portion abuts on the wall surface formed in the throttle body. Being

corrugated, the peripheral edge portion helps make flexure to occur easily. Accordingly, the peripheral edge portion contacts tightly the wall surface for added sealing performance. [0015]
According to the fourth aspect of the present invention, the throttle valve main body can be inserted into the throttle body from the small diameter portion thereof. This facilitates assembly. [0016]
According to the fifth aspect of the present invention, the side of the peripheral edge of the extension of the elastic portion can be pressed up against the wall surface of the throttle body even better by the load being applied to the throttle valve main body in an extended direction of the axis. This enhances sealing performance.
[Best Mode for Carrying out the Invention] [0017]
A specific embodiment to which the present invention is applied will be described below with reference to the accompanying drawings. Fig. 2 is a cross-sectional view showing a principal portion of an internal combustion engine including a throttle valve

device according to a preferred embodiment of the present invention. Referring to Fig. 2, an intake valve 3 is disposed in an intake port 2 formed in a cylinder head 1 of the internal combustion engine. An intake pipe 4 for introducing the air-fuel mixture to the intake port 2 includes a connector 5, a heat insulator 6, an air cleaner case 7, and a throttle body 8. The connector 5 is connected to the cylinder head 1. The heat insulator 6 is formed from a heat insulating material. A fuel injection valve 9 is disposed at a portion of the intake pipe 4 formed by a lower portion of the air cleaner case 7. The fuel injection valve 9 is disposed such that an injection orifice thereof is oriented toward an inside of the intake pipe 4. The heat insulator 6 prevents heat from being directly conducted from the engine to the air cleaner case 7 and the throttle body 8. The heat insulator 6 thereby allows the air cleaner case 7 and the throttle body 8 to be formed from a resin material having relatively low heat resistance. [0018]
The throttle body 8 is built into an inside of the air cleaner case 7. Air cleaned by an air cleaner main body (an air filter) not shown is introduced into the intake pipe 4 through the enlarged intake port 81

disposed at an upper portion of the throttle body 8 during an intake stroke of the internal combustion engine. A throttle valve main body 10 is swingably journaled on the throttle body 8. The throttle valve main body 10 includes a butterfly valve portion (hereinafter referred to simply as "valve portion") 11 and a shaft portion 12 supporting the valve portion 11 on the throttle body 8. [0019]
Fig. 1 is a cross-sectional view showing the throttle valve device. Fig. 3 is a side elevational view showing the throttle valve device. Referring to Figs. 1 and 3, the shaft portion 12 includes a large diameter part 13 disposed on an upper portion and a small diameter part 14 disposed on a lower portion. The valve portion 11, and the intake pipe 4 at least at a position at which the valve portion 11 is disposed, have a generally rectangular cross section. The valve portion 11 abuts on a surface of a step formed inside the throttle body 8 in a throttle closed condition. This step is formed by shifting an axis of the intake pipe 4 between an upstream side of the valve portion 11 and a downstream side of the valve portion 11 (see the cross-sectional view of the throttle body 8 shown in Fig. 2).

Specifically, the large diameter part 13 and the small diameter part 14 are set to have a diameter as detailed in the following. More specifically, the large diameter part 13 has a diameter larger than one side (that is, the maximum dimension of the valve portion in a direction orthogonal to the shaft portion 12) of a rectangle of the valve portion 11. The small diameter part 14 has a diameter smaller than one side of the rectangle of the valve portion 11. The valve portion 11 is connected to the large diameter part 13 and the small diameter part 14 on corresponding ones of both ends thereof. The valve portion 11 is thus situated at an intermediate portion between the large diameter part 13 and the small diameter part 14. The large diameter part 13 is inserted in a sleeve 15 that protrudes from the throttle body 8. The small diameter part 14 is inserted in an inner wall 17 of a dual sleeve 16 that protrudes in a direction opposite to the sleeve 15 via a collar 18. An end portion of the small diameter part 14 protrudes from the inner wall 17. A washer 19 is passed over the protruded portion and a stop ring 20 is then fitted thereto. The throttle valve main body 10 is thereby prevented from coming off the throttle body 8.

The valve portion 11 includes an elastic portion 21 that covers the valve portion 11. The elastic portion 21 includes annular portions 22, 23 that extend to the large diameter part 13 and the small diameter part 14, respectively, from the valve portion 11. A peripheral edge of the annular portions 22, 23 is corrugated such that a portion thereof in abutment with the throttle body 8 flexes easily to provide a good adhesion. It is preferable that the elastic portion 21 be formed from an elastic polymer. The elastic polymer offers superior chemical resistance. Operation of the elastic portion 21 will be described later. [0022]
The valve portion 11 and the shaft portion 12 are integrally formed through plastic molding. The elastic portion 21 is added through molding to the plastic-molded valve portion 11 and the shaft portion 12. [0023]
A torsion spring 24 for urging the shaft portion 12 in a throttle closing direction is mounted on an outer periphery of the sleeve 15. One end of the torsion spring 24 is secured to a base portion of the sleeve 15, while the other end of the torsion spring 24 is secured to a flange portion 25 that overhangs at an upper portion of

the large diameter part 13. The flange portion 25 includes an annular groove 2 6 formed along an outer periphery thereof. A throttle cable 27 is mounted on the flange portion 25 as guided by the annular groove 26. One end of the throttle cable 2 7 is connected to the flange portion 25 using a pin 28, while the other end of the throttle cable 27 is connected to an accelerator operating portion not shown (a grip of a steering handlebar in a motorcycle). [0024]
The torsion spring 24 is provided on the shaft portion 12 so as to urge the valve portion 11 in a throttle fully closed direction. The throttle cable 27 is mounted on the flange portion 25 such that, when the throttle cable 27 is pulled, the shaft portion 12 is rotated in a direction opposite to the urging direction by the torsion spring 24, thus opening the throttle. [0025]
The throttle valve main body 10 is assembled to the throttle body 8 as detailed in the following. Specifically, the throttle valve main body 10 is inserted into the throttle body 8 from the side of the small diameter part 14 relative to the sleeve 15. Let the small diameter part 14 pass through the inner wall 17 of the

dual sleeve 16 and allow an end portion of the small diameter part 14 to protrude from the inner wall 17. Then, fit the washer 19 and the stop ring 20 to an outer periphery of the end portion of the small diameter part 14. Since the throttle valve main body 10 includes the large diameter part 13 and the small diameter part 14, it is easy to assemble the throttle valve main body 10 to the throttle body 8 from one direction. [0026]
The throttle valve main body 10 is assembled to the throttle body 8 so that a positive sealing performance can be achieved when a peripheral edge of the elastic portion 21, or a side surface in particular is pressed by the throttle body 8 ♦ Specifically, the stop ring 20 is fitted to the shaft portion 12 with a thrust load applied by the torsion spring 24 in a direction oriented from the side of the large diameter part 13 toward the side of the small diameter part 14 (in a direction B to be described later). [0027]
A coupling shaft 29 for connecting a throttle sensor 28 to the small diameter part 14 is connected to the small diameter part 14. The throttle sensor 128 is, for example, a variable resistor. The throttle sensor 128

can detect throttle opening based on a resistance value that corresponds to a rotational position of the coupling shaft 29 connected to the small diameter part 14. [0028]
Fig. 4 is a perspective view showing a completed throttle valve main body 10. The same reference numerals as those used in Figs. 1 and 3 indicate like or identical parts. [0029]
Figs. 5 through 10 are explanatory views illustrating a molding method for the throttle valve main body 10 and the elastic portion 21. In molding, a mold 30 for molding (injection molding) the throttle valve main body 10 without the elastic portion 21 is first prepared as shown in Fig. 5. The mold 30 includes a part 301 and a part 302. A resin 31 is injected into the mold 30 through a resin injection port 303. When a sufficient amount of the resin 31 has been injected into the mold 30 as shown in Fig. 6, the injection sequence is terminated. The mold 30 is thereafter left to stand until the resin 31 cools down and the mold 3 0 is then removed (by pulling the parts 301, 302 in the direction of an arrow in Fig. 7). [0030]
A mold 33 is next prepared (Fig. 8) . The mold 33

is use for integrally adding the elastic portion 21 to a core part (that is, the throttle valve main body 10 to which the elastic portion 21 is yet to be added) 32 of the throttle valve main body 10 made through the steps described above. The mold 33 includes a part 331 and a part 332. When the core part 32 of the throttle valve main body 10 is fitted inside the mold 33, a space 34 for the elastic portion 21 is created as shown in Fig. 9. An elastic polymer 3 6 is then injected through an elastic polymer injection port 35. Fig. 10 shows a condition, in which the space 34 is filled with the elastic polymer. After cooling, the mold 33 is removed. This completes the throttle valve main body 10 representing the core part 32 of the throttle valve main body 10 added integrally with the elastic polymer 3 6 as the elastic portion 21 (see Fig. 4) . [0031]
Fig. 11 is a cross-sectional view showing an engagement portion between the valve portion 11 and the throttle body 8. Referring to Fig. 11, in a throttle fully closed condition, the valve portion 11 is urged in the direction of an arrow A by a force of the torsion spring 24. As a result, edges 211 of the elastic portion 21 covering the valve portion 11 are pressed against

steps 81, 82 in the throttle body 8. Being pressed against the steps 81, 82, the elastic portion 21 is deformed and brought into positive contact with surfaces of both of the steps 81, 82.
[0032]
Fig. 12 is a cross-sectional view showing an engagement portion between the elastic portion 21 and the throttle body 8. Referring to Fig. 12, the throttle valve main body 10 is assembled to the throttle body 8 with a thrust load being applied in the direction of an arrow B. Accordingly, the annular portions 22, 23 of the elastic portion 21 are flexed by being pressed up against surfaces of steps 83, 84, respectively, in the throttle body 8 by the thrust load. The amount of flexing depends on variations in tolerances of the throttle valve main body 10 or throttle body 8. In the example shown in Fig. 12, the annular portion 23 is flexed more than the annular portion 22.
[0033]
In Fig. 12, the elastic portion 21 includes overhang parts 39, 4 0 that overhang in the large diameter part 13 and the small diameter part 14 after having passed through holes 37, 38 made in the large diameter part 13 and the small diameter part 14, respectively. The

large diameter part 13 and the small diameter part 14 are pinched between the overhang parts 39, 4 0 and the annular portions 22, 23. This provides an even more positive connection between the elastic portion 21 and a core part 32 of the throttle valve main body 10. [0034]
The valve portion 11 may also be provided with a hole or a recessed portion, in which the elastic polymer can be flowed during molding, thereby making an even greater joint between the valve portion 11 and the elastic portion 21. Fig. 13 is a perspective view showing the valve portion 11 without the elastic portion 21. A surface of the valve portion 11 is provided with a plurality of recessed portions 41. A surface of the shaft portion 12 in tight contact with the annular portions 22, 23 may also be provided with the recessed portions 41. It is also appropriate that the valve portion 11 be provided with a through hole therein, instead of the recessed portions 41. The number of such through holes is not specified. Further, holes and recessed portions may be mixed together. [0035]
As described in the foregoing, according to the preferred embodiment of the present invention, the

elastic portion 21 of the valve portion 11 achieves a positive seal between the throttle valve main body 10 and the throttle body 8. [0036]
The shaft portion 12 may have a constant shaft diameter without including the large diameter part having a larger shaft diameter on the side of the flange 25. It is.also appropriate to make the shaft diameter on the side of the flange 25 smaller. In such cases, a bearing (bushing) for supporting the shaft on the side of the flange 25 (the large diameter part in Fig. 1) adopting a two-part structure is to be used so as to permit insertion of the throttle valve main body 10 from one side of the throttle body 8. The bearing of the two-part structure has a partition surface along the longitudinal direction of the shaft portion 12, with which the bearing is divided.
[Brief Description of the Drawings] [0037] [Fig. 1]
Fig. 1 is a cross-sectional view showing a throttle valve device according to a preferred embodiment of the present invention.

Fig. 2 is a cross-sectional view showing an intake system including the throttle valve device according to the preferred embodiment of the present invention. [Fig. 3]
Fig. 3 is a side elevational view showing the throttle valve device according to the preferred embodiment of the present invention. [Fig. 4]
Fig. 4 is a perspective view showing a throttle valve main body 10. [Fig. 5]
Fig. 5 is an explanatory view illustrating a molding method for the throttle valve main body and an elastic portion. [Fig. 6]
Fig. 6 is an explanatory view illustrating a molding method for the throttle valve main body and the elastic portion. [Fig. 7]
Fig. 7 is an explanatory view illustrating a molding method for the throttle valve main body and the elastic portion. [Fig. 8]
Fig. 8 is an explanatory view illustrating a

molding method for the throttle valve main body and the elastic portion. [Fig. 9]
Fig. 9 is an explanatory view illustrating a molding method for the throttle valve main body and the elastic portion. [Fig. 10]
Fig. 10 is an explanatory view illustrating a molding method for the throttle valve main body and the elastic portion. [Fig. 11]
Fig. 11 is a cross-sectional view showing an engagement portion between a valve portion and a throttle body. [Fig. 12]
Fig. 12 is a cross-sectional view showing an engagement portion between the elastic portion and the throttle body. [Fig. 13]
Fig. 13 is a perspective view showing the valve portion without the elastic portion. [Fig. 14]
Fig. 14 is a cross-sectional view showing a conventional art that exemplifies variations in sealing

performance occurring from angular tolerances of the throttle body and the butterfly valve portion.
[Fig. 15]
Fig. 15 is a cross-sectional view showing a conventional art that exemplifies variations in sealing performance occurring from tolerances in an axial length of the throttle body and the throttle valve main body.
[Description of Reference Numerals]
1: Cylinder head
2: Intake port
4: Intake pipe
7: Air cleaner case
8: Throttle body
10: Throttle valve main body
11: Valve portion
12: Shaft portion
13: Large diameter part
14: Small diameter part
15: Sleeve
21: Elastic portion




[Nameof/document] Claims [Claiml]
A throttle valve device for an internal combustion engine, comprising:
a throttle valve main body; and
a throttle body for accommodating the throttle valve main body;
wherein the throttle valve main body includes a butterfly valve portion for opening or closing an intake path portion inside the throttle body and a shaft portion for supporting the butterfly valve portion relative to the throt tie body; and
the butterfly valve portion is covered with an elastic portion. [Clainr 2]
The throttle valve device according to claim 1,
wherein the elastic portion is fixed to the throttle valve main body through a dual molding method, in which an elastic material is added through molding to a pre-molded throttle valve main body. [Claim/3]
The throttle valve device according toclaim__2;
wherein the throttle valve main body includes a recessed portion and/or a hole, which the elastic

material can enter. [Claim/4]
The throttle valve device according to any one of claims 1 to 3,
wherein the elastic portion is extended from the valve portion to the shaft portion to form an extension and the extension includes a corrugated peripheral edge; and
the throttle body includes a wall surface, on which the peripheral edge abuts. [Clain/5]
The throttle valve device according to any one of claims 1 to 4,
wherein the butterfly valve portion and the shaft portion are an integral structure made of resin; and
the shaft portion has two sections of different diameters, a first section being disposed on one side of the butterfly valve portion, the first section having a diameter greater than the maximum dimension of the butterfly valve portion, and a second section being disposed on the other side of the butterfly valve portion, the second section having a diameter smaller than the maximum dimension of the butterfly valve portion. [Clairn/b]

The throttle valve device according to claim 4 /6a?\ 5, wherein the throttle valve main body is positioned relative to the throttle body along an axis of the shaft portion in a condition of being loaded on one side along the axis of the shaft portion.


Documents:

1320-CHE-2005 CORRESPONDENCE OTHERS 25-08-2011.pdf

1320-CHE-2005 AMENDED CLAIMS 11-03-2011.pdf

1320-che-2005 amended claims 25-08-2011.pdf

1320-CHE-2005 AMENDED PAGES OF SPECIFICATION 11-03-2011.pdf

1320-che-2005 form-3 11-03-2011.pdf

1320-CHE-2005 OTHER PATENT DOCUMENT 11-03-2011.pdf

1320-CHE-2005 POWER OF ATTORNEY 11-03-2011.pdf

1320-CHE-2005 CORRESPONDENCE OTHERS.pdf

1320-CHE-2005 CORRESPONDENCE PO.pdf

1320-CHE-2005 EXAMINATION REPORT REPLY RECIEVED 11-03-2011.pdf

1320-CHE-2005 FORM-18 29-08-2007.pdf

1320-che-2005-abstract image.jpg

1320-che-2005-abstract.pdf

1320-che-2005-claims.pdf

1320-che-2005-correspondnece-others.pdf

1320-che-2005-description(complete).pdf

1320-che-2005-drawings.pdf

1320-che-2005-form 1.pdf

1320-che-2005-form 3.pdf

1320-che-2005-form 5.pdf

1320-che-2005-other document.pdf


Patent Number 249212
Indian Patent Application Number 1320/CHE/2005
PG Journal Number 41/2011
Publication Date 14-Oct-2011
Grant Date 11-Oct-2011
Date of Filing 19-Sep-2005
Name of Patentee HONDA MOTOR CO., LTD.
Applicant Address 1-1 MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO
Inventors:
# Inventor's Name Inventor's Address
1 YAMAMOTO, TOSHIO C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME WAKO-SHI, SAITAMA
2 IIMURO, AKIHIRO C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME WAKO-SHI, SAITAMA JAPAN
3 HIKICHI, TOICHIRO C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME WAKO-SHI, SAITAMA JAPAN
PCT International Classification Number F02D9/10
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2004-277760 2004-09-24 Japan