JPH0674348A - Throttle valve unit - Google Patents

Abstract

PURPOSE:To improve air-tightness at the time of fully closing a throttle valve without improving shape accuracy in a seat part by providing an elastic material of rubber or the like in a peripheral edge of the throttle valve for serving as the seat part, in a throttle valve unit having the throttle valve of butterfly type arranged in an intake passage. CONSTITUTION:A protrusive streak part 3 protruded toward inward is formed in an internal peripheral surface to also rotatably support a throttle valve 4, in an intake passage 2 formed in a main unit 1 of a throttle valve unit. An elastic member 5 of rubber or the like is mounted on a peripheral part of this throttle valve 14 by an adhesive agent or the like, and a compression margin per load of this elastic member 5 is set so as to increase in accordance with separating from an axial center of the throttle valve. Thus even when generated displacement more or less between the throttle valve 4 and a seat part of the protrusive streak part 3 by an influence of misalignment of a throttle valve shaft, flatness of a seat surface, etc., the seat surface can be closely attached almost over a total area by elastically deforming the elastic member 5, and air-tightness at the time of fully closing the throttle valve is improved without increasing shape accuracy of the seat part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve body for controlling a fluid by a butterfly type throttle valve, and more particularly to a structure for improving airtightness when the throttle valve is fully closed and for improving manufacturability.

[0002]

2. Description of the Related Art In a conventional device, as shown in Japanese Utility Model Publication No. 3-20609, an elastic body such as rubber is arranged on the inner peripheral surface of a throttle valve body, and the elastic body is provided with an outer body of a rigid throttle valve. A throttle valve body which makes a sheet contact with its peripheral edge is known.

Since the elastic body of the throttle valve body is separate from the main body, many man-hours are required for assembly work, or the rotary sliding portion of the valve shaft is provided in the elastic body, which makes the mechanism complicated. It was difficult to reduce costs.

Further, such a throttle valve seating method is supposed to be used in a so-called squeezed state in which the valve body is strongly pressed against the seat ring, so as to ensure airtightness when the closing force of the valve body is small. Was not taken into consideration.

[0005]

SUMMARY OF THE INVENTION The present invention simplifies the structure of the seat portion of the throttle valve, thereby reducing the cost and increasing the degree of freedom in manufacturing the shape of the seat portion. An object of the present invention is to provide a seat portion shape that can ensure airtightness when the valve is closed even when the closing force is small.

[0006]

In order to achieve the above object, the seat member on the main body side of the throttle valve is made rigid and an elastic material such as rubber is used on the outer peripheral edge of the throttle valve.

Preferably, a convex portion which serves as a stopper for the throttle valve is provided on the inner peripheral portion of the main body, and this portion serves as a seat portion.

Further, preferably, the elastic sheet portion has a beat shape.

Further, it is preferable that the compression margin per load of the elastic body becomes larger as the distance from the throttle shaft increases.

[0010]

In the present invention, the structure on the main body side can be simplified by providing the throttle valve with the elastic member. As a result, the number of parts can be reduced and the number of assembling steps can be reduced, and the cost can be reduced.

Further, according to the above construction, the degree of freedom of the shape of the elastic member is increased, and it becomes possible to easily manufacture a shape that matches the displacement generated by the pressure difference between the upstream and downstream sides of the throttle valve.

As a result, the seat portion can be provided with a beat shape, the surface pressure can be kept high even when the closing force of the throttle valve is small, and the airtightness at the time of closing the valve can be secured.

Further, the compression margin per load of the elastic member is increased as the distance from the throttle valve shaft increases, so that the throttle valve can be rotated in the closing direction due to the pressure difference between the upstream and downstream sides, further improving the airtightness. be able to.

[0014]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a sectional view taken along a plane orthogonal to the throttle valve axis according to an embodiment of the present invention. Reference numeral 1 denotes a main body of the throttle valve, which forms an intake passage 2. A ridge portion 3 that protrudes inward is provided on the inner peripheral surface of the intake passage. The throttle valve 4 is attached to the main body 1 so as to be rotatable. An elastic member 5 such as rubber is attached to the outer peripheral portion of the throttle valve 4 with an adhesive material or the like. The method of attaching the elastic member is not particularly limited, but generally, using an adhesive, a snap fit method, or the like is an easily performed means. By doing so, the shape of the elastic member 5 can be freely set, and the throttle valve 4 and the elastic member 5 can be handled as an integral part and can be easily assembled to the main body 1. Further, the main body 1 can be easily manufactured with a molding die or the like. In particular, even if the throttle valve 4 and the seat portion of the protruding portion 3 are slightly displaced due to the misalignment of the throttle shaft, the flatness of the seat surface, etc., the elastic member 5 deforms the seat surface so that the seat surface is almost flat. Since the whole area can be adhered, it is not necessary to improve the accuracy of the main body 1, and the resin can be easily made into resin.

FIG. 2 shows another embodiment of the present invention, and the reference numerals are the same as those in FIG. In the present embodiment, the sheet surface of the protrusion 3 is an inclined surface as compared with FIG. Further, the elastic member 5 is provided with a beat-shaped protrusion on the seat portion.
The shape of this protrusion is not particularly limited. By doing so, the surface pressure of the seat portion can be increased and the degree of freedom of deformation of the elastic member 5 can be increased as compared with FIG.

FIG. 3 is a diagram modeling the deformation margin of the elastic member of the throttle valve due to the compressive load. The shaded portion 6 indicates the compression margin per load of the elastic member. The compression margin is set to increase as the distance from the throttle shaft axis increases. The method of changing the compression allowance is not particularly limited, but generally, a means for changing the thickness, width, etc. of the elastic member can be considered. By doing so, when the load generated by the pressure difference between the upstream and downstream of the throttle valve when the throttle valve is fully closed is applied to the throttle valve,
The displacement of the throttle valve tip is larger than that near the throttle shaft. For this reason, a force that rotates in the closing direction is generated in the throttle valve, and this force can further increase the surface pressure of the seat surface over the entire area. Even when the throttle valve closing force from the outside is small, the airtightness is improved. Can be kept.

[0018]

According to the present invention, since the elastic member is provided on the outer peripheral portion of the throttle valve, the airtightness when the throttle valve is fully closed can be improved without increasing the shape accuracy of the seat portion. Moreover, since the shape and structure of the components forming the seat portion can be simplified, the manufacturing cost can be reduced.

Further, since the elastic member is provided with a beat and the compression margin is changed, airtightness can be secured even when the closing force of the valve body is small.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment according to the present invention and is a sectional view taken along a plane orthogonal to a throttle valve axis.

FIG. 2 is a view showing another embodiment according to the present invention and is a sectional view taken along the same plane as FIG.

FIG. 3 is a model diagram of a throttle valve.

[Explanation of symbols]

1 ... Main body, 2 ... Intake passage, 3 ... Ridge portion, 4 ... Throttle valve, 5 ...
Elastic member, 6 ... compression allowance per load.

Claims (4)

[Claims] 1. A throttle body having a main body which is disposed in the intake passage and forms a part of a substantially cylindrical intake passage, and a throttle type throttle valve which is rotatably held by a bearing portion provided in the main body. An elastic material such as rubber is used for the outer peripheral edge of the throttle valve that serves as the seat portion. 2. The throttle valve body according to claim 1, wherein a convex portion projecting inward from the inner peripheral surface of the main body is formed, and the throttle valve is brought into contact with the convex portion to close the valve. Throttle valve characterized by having done. 3. The throttle valve body according to claim 1 or 2, wherein the seat portion of the elastic material at the outer peripheral edge of the throttle valve is formed into a beat shape. 4. The throttle valve body according to claim 2 or 3, wherein a compression margin per load of the elastic body increases as the distance from the throttle valve shaft increases.