JPH0680837U - Exhaust gas control valve - Google Patents

Abstract

(57) [Abstract] [Purpose] In an exhaust gas control valve applied to an exhaust system through which exhaust gas flows, it is intended to prevent the butterfly valve body from being stuck and stuck to the inner wall of the exhaust pipe. [Structure] In an exhaust gas control valve 1 provided with a coil spring 15 that applies a biasing force in a fully closing direction to a rotating shaft 2 to which a butterfly valve body 3 is fixed, an entire circumferential end portion of the butterfly valve body 3 is provided. The curved surface 3a is formed by a smooth curved surface.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an exhaust gas control valve used in a vehicle exhaust system or the like.

[0002]

[Prior art]

 In recent years, a vehicle exhaust system has dual exhaust pipes, and a control valve is attached to one of the exhaust pipes to control the flow of exhaust gas in the exhaust pipes according to the engine speed, and when the engine is running at low speeds. Exhaust gas control valves are being installed to reduce exhaust noise at high engine speeds.

As this exhaust gas control valve, as shown in FIG. 7, for example, the one described in Japanese Utility Model Laid-Open No. 62-76227 is known.

According to the conventional source, the exhaust gas passage 102 is closed via the butterfly valve body 101 when the engine speed is low, and the exhaust gas passage 102 is opened by the butterfly valve body 101 when the engine speed is high. What you have done is shown.

Reference numeral 103 is an exhaust pipe, and 104 is a rotating shaft to which the butterfly valve body 101 is fixed. The rotating shaft 104 is provided with a butterfly valve body 101 when the butterfly valve body 101 is fully closed. A biasing force is applied in the fully closing direction by a coil spring (not shown) so as not to open due to exhaust gas pressure.

[0006]

[Problems to be solved by the device]

 However, in the above-mentioned conventional technique, since the peripheral end portion of the butterfly valve body 101 is formed with a sharp corner over the entire circumference, the difference in thermal expansion between the exhaust pipe 103 and the butterfly valve body 101 (exhaust pipe> butterfly). Due to the valve body, the butterfly valve body 101 may bite and stick to the inner wall of the exhaust pipe 103.

That is, when the exhaust pipe 103 is thermally expanded by the exhaust gas heat to expand the inner diameter when the valve is fully closed, the butterfly valve can be rotated according to the urging force in the fully closing direction by allowing the rotation allowance corresponding to the expansion of the inner diameter. The body 101 slightly rotates, and the valve rotation causes the peripheral end portion of the butterfly valve body 101 to move along the inner wall of the exhaust pipe 103.

In this state, when the temperature of the exhaust pipe 103 is reduced due to the engine stop or the like and the exhaust pipe 103 is thermally contracted, the peripheral end portion of the butterfly valve body 101 is formed to have a sharp corner. Due to the contact resistance, the butterfly valve body 101 does not move back to its original position along the inner wall of the exhaust pipe 103.

As described above, since the butterfly valve element 101 does not follow the inner diameter of the exhaust pipe 103, as shown in FIG. 8, the butterfly valve element 101 bites and sticks to the inner wall of the exhaust pipe 103. To do.

As a result, when the biting sticking force of the butterfly valve body 101 is large, the valve is fully opened unless the rotary shaft is given a turning force to overcome the sticking force even if the valve is to be fully opened next time. You will not be able to do this.

The present invention has been made in view of the above problems, and an object thereof is to provide a butterfly valve body in an exhaust gas control valve applied to an exhaust system through which exhaust gas flows. It is intended to prevent the sticking and sticking to the inner wall of the exhaust pipe.

[0012]

[Means for Solving the Problems]

 In order to achieve the above object, in the exhaust gas control valve of the present invention, at least the peripheral end portion of the butterfly valve body that contacts the inner wall of the exhaust pipe when the valve is fully closed is formed into an arc surface.

That is, a rotary shaft inserted through a position passing through the center of a cross section of the exhaust pipe and a position fixed to the rotary shaft and slightly inclined from an axis orthogonal to the exhaust pipe axis are disposed in the exhaust gas passage. In the exhaust gas control valve, the butterfly valve element is provided in a fully closed position to close the valve, and a spring member is provided to apply a biasing force in a fully closing direction to a rotating shaft to which the butterfly valve element is fixed. Among the peripheral end portions of the valve body, at least the peripheral end portion which comes into contact with the inner wall of the exhaust pipe when the valve is fully closed is formed into an arc surface.

[0014]

[Action]

 When the exhaust pipe thermally expands due to the exhaust gas heat when the valve is fully closed and the inner diameter increases, the butterfly valve body can be rotated according to the expansion of the inner diameter, so that the butterfly valve body is biased in the fully closing direction by the spring member. Rotates slightly, and this rotation causes the peripheral end of the butterfly valve element to move along the inner wall of the exhaust pipe.

In this state, when the temperature of the exhaust pipe is reduced due to engine stop or the like and the exhaust pipe is thermally contracted, the butterfly valve body comes into contact with the inner wall of the exhaust pipe at least when the valve is fully closed. Since the peripheral edge is formed into an arc surface, the contact resistance between the exhaust pipe inner wall and the butterfly valve body is suppressed to a low level, and the butterfly valve body moves only along the inner wall of the exhaust pipe to return to its original position. To be

In this way, the butterfly valve element moves following the reduction of the inner diameter of the exhaust pipe, so that the butterfly valve element is prevented from sticking and sticking to the inner wall of the exhaust pipe.

[0017]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration will be described.

FIG. 1 is an overall sectional view of an exhaust gas control valve according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG.

In FIG. 1, 1 is an exhaust gas control valve, 2 is a rotating shaft, 3 is a butterfly valve body, and 4 is an exhaust pipe.

The rotating shaft 2 is inserted and arranged at a position passing through the center of the cross section of the exhaust pipe 4.

Here, the exhaust pipe 4 means both a pipe directly used for an exhaust system such as a tail pipe and the meaning of a valve case attached to the exhaust system as in the case of a valve unit configuration. Including.

The butterfly valve body 3 is fixed to the rotary shaft 2 with a set screw 5, and as shown in FIG. 2, the butterfly valve body 3 is a member that completely blocks the exhaust gas flow path at a position slightly inclined from the axis orthogonal to the exhaust pipe axis. Set to the closed position. A circular arc surface 3a having a smooth curved surface is formed on the entire circumferential end portion of the butterfly valve body 3.

The support of the rotary shaft 2 with respect to the exhaust pipe 4 is supported by bearings 8 and 9 provided in bearing cases 6 and 7 fixed to the exhaust pipe 4 so as to be rotatable at both ends. The bearings 8 and 9 are made of carbon, for example.

A traction plate 13 and a spring receiver 14 are arranged on a shaft portion of the rotary shaft 2 protruding from the exhaust pipe 4, and a butterfly valve body 3 is fixed to the rotary shaft 2 between the two. On the other hand, a coil spring 15 (corresponding to a spring member) that applies a biasing force in the fully closing direction is provided. The other end of the wire 17 whose one end is connected to an actuator (not shown) is connected to the protrusion 16 fixed to the towing plate 13.

Next, the operation will be described.

[Adhesion Preventing Action when Valve is Fully Closed] When the exhaust pipe 4 is thermally expanded by exhaust gas heat and the inner diameter is expanded when the valve is fully closed, the coil spring 15 can be rotated by a margin corresponding to the expansion of the inner diameter. The butterfly valve body 3 is slightly rotated according to the urging force of the butterfly valve body 3 in the direction of full closing, and this rotation causes the peripheral end portion (arc surface 3a) of the butterfly valve body 3 to follow the inner wall of the exhaust pipe 4 as indicated by arrow B in FIG. Move as shown in.

In this state, when the temperature of the exhaust pipe 4 is reduced due to engine stop or the like and the exhaust pipe 4 is thermally contracted, the peripheral end portion of the butterfly valve body 3 in contact with the inner wall of the exhaust pipe is formed by a smooth curved surface. By forming the arcuate surface 3a, the contact resistance between the exhaust pipe inner wall and the butterfly valve body 3 is suppressed to a small level, and the butterfly valve body 3 extends along the inner wall of the exhaust pipe 4 as shown by an arrow C in FIG. There is a movement back to the original position.

In this way, the butterfly valve body 3 moves following the reduction of the inner diameter of the exhaust pipe 4, so that the butterfly valve body 3 is prevented from sticking to and fixing to the inner wall of the exhaust pipe 4.

[Gas flow action when the valve is fully opened] When the valve is fully opened, the butterfly valve body 3 is present in the flow of the exhaust gas passing through the exhaust pipe 4, as shown in FIG.

On the other hand, since the entire circumferential end portion of the butterfly valve body 3 is formed into the circular arc surface 3a having a smooth curved surface, the turbulent flow near the tip portion of the butterfly valve body 3 is suppressed to a small level, and the butterfly valve body 3 is suppressed. The exhaust gas passing through the butterfly valve body 3 passes through the upper and lower parts of the valve body 3 and suppresses the turbulence near the rear end of the butterfly valve body 3, as shown by the arrow in FIG. It becomes a smooth flow.

Next, the effect will be described.

(1) In the exhaust gas control valve 1 applied to the exhaust system through which exhaust gas flows, the butterfly valve body 3 has the entire circumferential end portion formed into a circular arc surface 3a having a smooth curved surface. It is possible to prevent bite and stick to the inner wall of the exhaust pipe 4.

(2) With the adoption of the method of forming the peripheral end portion of the butterfly valve body 3 on the arc surface 3 a as a solution method for preventing the bite and sticking, the exhaust pressure loss is reduced and the air flow noise is reduced when the valve is fully opened. Occurrence can be prevented.

Although the embodiments have been described above with reference to the drawings, the specific configuration is not limited to the embodiments, and modifications and additions within the scope of the present invention are included in the present invention. Be done.

For example, in the embodiment, the example in which the entire circumferential end portion of the butterfly valve body 3 is the arcuate surface 3a having a smooth curved surface is shown. However, as shown in FIG. Only the peripheral end portion of the butterfly valve body 18 that comes into contact may be the semicircular arc surface 3b.

Further, as shown in FIG. 6, the entire circumferential end portion of the butterfly valve body 3 is formed into an arc surface 3a having a smooth curved surface, and both sides of the butterfly valve body 3 are smoothly connected to the arc surface 3a. The dome surface 3c may be used. In this case, the flow of exhaust gas when the valve is fully opened becomes smoother, and exhaust pressure loss can be reduced and air flow noise can be prevented at a high level when the valve is fully opened.

[0038]

[Effect of device]

 As described above, according to the present invention, in the exhaust gas control valve applied to the exhaust system through which the exhaust gas flows, the exhaust pipe inner wall at least when the butterfly valve body has its peripheral end portion fully closed. Since the peripheral end that contacts with is formed into an arc surface, it is possible to prevent the butterfly valve body from biting and sticking to the inner wall of the exhaust pipe, reduce exhaust pressure loss and prevent air flow noise when the valve is fully opened. The effect that can be obtained is obtained.

[Brief description of drawings]

FIG. 1 is an overall sectional view of an exhaust gas control valve of an embodiment.

FIG. 2A of FIG. 1 showing the valve fully closed state of the embodiment valve
FIG.

FIG. 3 is an explanatory view of a sticking prevention action of the embodiment valve when the valve is fully closed.

FIG. 4 is a diagram showing a flow of exhaust gas when the valve of the embodiment valve is fully opened.

FIG. 5 is a cross-sectional view of a butterfly valve body with different valve body shapes.

FIG. 6 is a cross-sectional view of a butterfly valve body with different valve body shapes.

FIG. 7 is a partially cutaway vertical sectional view of an exhaust pipe to which a butterfly valve body having a conventional shape is attached.

FIG. 8 is a diagram showing a state in which a conventional butterfly valve element is fixed to an exhaust pipe.

[Explanation of symbols]

 1 Exhaust gas control valve 2 Rotating shaft 3, 3 ', 3 "Butterfly valve body 3a Arc surface 3b Semi-circular surface 3c Dome surface 4 Exhaust pipe

Claims (1)

[Scope of utility model registration request] 1. A rotary shaft inserted through a position passing through a center of a cross section of an exhaust pipe, and a position fixed to the rotary shaft and slightly tilted from a shaft orthogonal to the exhaust pipe shaft. An exhaust gas control valve including a butterfly valve body in a fully closed position for closing the valve, and a spring member that applies a biasing force in a fully closing direction to a rotating shaft to which the butterfly valve body is fixed, wherein the butterfly valve body An exhaust gas control valve, wherein at least a peripheral end portion of the peripheral end portion that contacts the inner wall of the exhaust pipe is formed into an arc surface when the valve is fully closed.