JPH027247Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an exhaust shutter installed in the middle of the exhaust pipe of an internal combustion engine, and more specifically, to an internal combustion engine that operates smoothly, has excellent exhaust and breakage, and is easy to operate. Regarding the exhaust shutter.

As a conventional exhaust shutter, there is an exhaust shutter A having a structure in which a butterfly-shaped valve body 2 is simply supported within a tubular valve box 1, as shown in FIG. 1 in a vertical side view. In the exhaust shutter A, the outer diameter of the butterfly valve body 2 is set to be considerably smaller than the inner diameter of the tubular valve box 1 in order to prevent the butterfly valve body 2 from expanding due to heat during use and becoming unable to open and close. . When such an exhaust shutter A is used, a problem arises in that the back pressure on the engine side is not sufficiently increased during exhaust braking, making it impossible to obtain a large braking force.

Further, as shown in a longitudinal side view in FIG. 2, there is an exhaust shutter B in which the butterfly-shaped valve body 2 is inclined at a predetermined angle with respect to the axis of the tubular valve box 1. Exhaust shutter B
Although the edge 2a of the butterfly-shaped valve body 2 is in close contact with the inner surface of the tubular valve body 1 when it is closed, the butterfly-shaped valve body 2 is installed at an angle with respect to the axis of the tubular valve body 1. Although it does not become impossible to open, it is easy to open due to exhaust gas pressure, and the problem is that it has poor sealing performance even though it is sealed tightly.

Therefore, as shown in the vertical side view in Figure 3,
Step portions 1'A and 1'B are formed on the inner surface of the tubular valve box 1',
An exhaust shutter C was proposed that made it possible to use a butterfly-shaped valve body 2 with a small outer diameter by using these stepped portions 1'A and 1'B as valve seats (Utility Model Publication No. 54-90523).
(see publication). In the case of exhaust shutter C, machining from the left and right sides of step portions 1'A and 1'B does not allow for dimensional errors because the machined surfaces sandwich the shutter's surface thickness.
It is necessary that the shutter surfaces are parallel and that the thickness of the shutter is maintained correctly. When this surface is not in the above state, the sealing performance on one side is poor and it is impossible to reduce this dimension after processing. In other words, the exhaust shutter is connected to the rotating shaft and the stepped portion 1' within this cylinder.
Its position is determined by the regulation of A or 1'B,
There will always be gaps on other surfaces. When an exhaust shutter is used, the pressure before and after the shutter is quite high, and the gas flow from the gap is at the speed of sound. Therefore, a considerable amount of exhaust gas leaks due to minute clearances.
The desired effect cannot be obtained.

The purpose of this invention is to solve all the problems mentioned above,
To provide an exhaust shutter for an internal combustion engine that has excellent sealing performance against exhaust gas, is extremely easy to manufacture, and does not require bending a flow path.

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

FIG. 4 shows an exhaust shutter D as an embodiment of the present invention in a longitudinal sectional side view. A butterfly-shaped valve body 2 is rotatably supported in the tubular valve box 1, and two sleeves 3 of the same shape are fitted in opposite directions with the butterfly-shaped valve body 2 in between. There is.

The sleeve 3 is shown in a longitudinal side view in FIG.
Fig. 5 is a side view, Fig. 6 is a front view as viewed from the Fig. 5 arrow,
As shown in FIG. 7 and a rear view in the direction of the arrows in FIG. is inclined at a required angle to enable use as a valve seat for a butterfly-shaped valve element, and its inner diameter is matched to the inner diameter of the exhaust pipe. The depth of the notch 4 is determined to be such that interference with the butterfly valve body 2 can be avoided in the assembled state.

In this embodiment, the sleeve 3 can be positioned and fixed to the tubular valve body 1 by using headless screws 5, but the height of the notch 4 can be determined without using screws or the like. If the sleeve 3 is fitted into the tubular valve box 1 so that the edge 4a of the notch 4 that intersects with the end surface 3a serving as the seat comes into contact with the vicinity of both ends of the shaft 6 of the butterfly-shaped valve body 2, the sleeve 3 will move in the circumferential direction. Therefore, it is only necessary to provide means for stopping movement in the axial direction.

In the exhaust shutter D of the present invention, after a butterfly-shaped valve body 2 is assembled into a tubular valve box 1, two sleeves 3 of the same shape,
The sleeve 3 can be assembled by inserting the sleeves 3 in opposite directions until they reach a fixed position, and the sleeve 3 may be fixed with a headless screw 5 if necessary.

The exhaust shutter D of the present invention manufactured in this way is installed in the exhaust pipe, and the butterfly-shaped valve body 2 uses the end surfaces 3a, 3a of the sleeves 3, 3 as valve seats to allow exhaust gas to flow as shown by the white arrow. I refuse. On the other hand, by making the inner diameter of the sleeve 3 match the inner diameter of the exhaust pipe, bending of the flow path can be avoided, so that the flow of exhaust gas is not disturbed.

The effects of the present invention are as follows.

Since the dimensions can be adjusted so that it comes into direct contact with the end face of the opening/closing shutter, it is possible to achieve perfect sealing with a simple structure even under high pressure.

Since we are using two sleeves of exactly the same shape,
It is economical because only one type of parts is required.

[Brief explanation of the drawing]

Figures 1, 2, and 3 are vertical side views showing examples of conventional exhaust shutters, Figure 4 is a vertical side view showing an embodiment of the exhaust shutter of the present invention, and Figure 5 is a side view of the sleeve. , Figure 6 is a front view as seen from the arrow in Figure 5,
FIG. 7 is a rear view as viewed from the arrow in FIG. DESCRIPTION OF SYMBOLS 1... Tubular valve box, 2... Butterfly-shaped valve body, 3... Sleeve, 3a... End surface, 4... Notch.

Claims (1)

[Scope of utility model registration request] A valve box with a built-in butterfly-shaped valve body is made of two sleeves of the same shape, with an approximately semicircular portion at one end of the short tubular material missing, and the end face of the remaining approximately semicircular portion serving as a valve seat for the butterfly-shaped valve body. An exhaust shutter for an internal combustion engine that is fitted inside the engine in opposite directions.