JPH086860B2 - Connecting pipe - Google Patents

Description

The present invention relates to a connecting pipe for connecting an engine and a carburetor, for example, which is located between the engine and the carburetor, and particularly has durability while ensuring its original function. The present invention relates to a connection pipe that can be improved.

[Conventional technology]

If the carburetor is directly attached to the engine, heat and vibrations from the engine are directly transmitted to the carburetor, which is not preferable. Therefore, conventionally, both of them are connected via a connecting pipe having a heat insulating / vibrating function to suppress the transmission of the above-mentioned vibration and the like.

As a connection pipe having such a heat insulating and vibration damping function, there is a conventional one having a structure shown in FIG. 5, for example. In the figure, 20 is a connecting pipe, which is the first and second connecting short pipes 21 and 22 made of metal such as aluminum and iron, arranged on the same axis line with a predetermined gap, and filling the gap. In addition, a rubber joint 23 having a shape that covers the outer surface is welded, whereby both connecting short pipes 21 and 22 are connected. The opposite end faces 21b, 22b of the connecting short pipes 21, 22 are formed in a straight line orthogonal to the axis.

This connecting pipe 20 is placed between the engine and the carburetor,
The carburetor is attached to the engine by connecting the flange portions 21a and 22a of the first and second connecting short pipes 21 and 22 to the engine and the carburetor, respectively. In this case, 2 short metal connecting pipes
Since it is divided into two parts and these are connected by the rubber joint 23, most of the heat and vibrations from the engine are absorbed in this divided part.

[Problems to be solved by the invention]

However, the conventional connecting pipe 20 has a problem that the joint 23 is likely to be cracked and the durability is low. The following points can be considered as the reason why this crack is likely to occur. That is, a load such as bending and twisting due to vibration is constantly acting on the connecting pipe 20, but this stress concentrates on the portion 23a filled in the gap of the joint 23, and this portion is connected. It is considered that this is because the short pipe separates and a crack is generated from the inside, and the crack easily progresses along the facing end surface of the connecting short pipe, that is, in the direction perpendicular to the axis.

Therefore, an object of the present invention is to solve the above conventional problems,
An object of the present invention is to provide a connecting pipe capable of suppressing the occurrence and progress of cracks and improving durability.

[Means for solving problems]

The present invention provides the connection pipe, wherein the first and second connection short pipes are connected by an elastic member composed of a tubular covering portion and a ridge portion that fills the facing end surface gap. It is characterized in that the opposite ends of the connecting short pipe are formed in a corrugated shape in which one concave portion and a convex portion and the other convex portion and a concave portion face each other.

[Action]

According to the connecting pipe of the present invention, since the opposing ends of the first and second connecting short pipes are formed in a corrugated shape, the adhesion area between the opposing ends and the ridges of the elastic member increases, and Since the peeling force is improved, the occurrence of cracks can be suppressed even if stress concentrates near the inner surface of the ridge portion of the elastic member.

Further, even if a crack occurs, since the ridge portion has a corrugated shape, stress concentration is likely to occur along this corrugated shape, that is, in the direction diagonally intersecting the axis, whereas the generated crack is It is easy to progress in the direction perpendicular to the axis, and since the directions are different from each other, it corresponds to the fact that the load is distributed, the progress of the cracks that have occurred can be suppressed, and as a result, durability can be improved and life can be extended.

〔Example〕

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

1 to 4 are views for explaining a connecting pipe according to an embodiment of the present invention. In the figure, reference numeral 1 is an engine in which a cylinder 3 and a cylinder head 4 are connected to an upper portion of a crankcase 2, and a carburetor 6 is connected to the cylinder head 4 through a connection pipe 5 of the present embodiment. . An air cleaner 7 is fixed to a vehicle body frame (not shown), and is connected to the carburetor 6 by an air joint 8.

The connecting pipe 5 is made by connecting the first and second connecting short pipes 9 and 10 made of metal with a joint 13 as an elastic member, and the flanges 9a, 10a is integrally formed. Also, the opposite ends 1 of the first and second connecting short pipes 9 and 10
Each of the concave portions 11a and the convex portion 1 has a corrugated shape in which concave portions 11a and 12a and convex portions 11b and 12b are formed at a predetermined pitch.
2b or the convex portion 11b and the concave portion 12a face each other, and the convex portion is inserted into the concave portion and overlaps when viewed in the circumferential direction, and as a result, the gap 14 between the opposite end portions has a wavy shape and the circumferential direction. There are regular intervals along.

Further, the joint 13 is made of rubber, and the both connecting short pipes 9,
A covering portion 13a covering the outer peripheral surface of 10, and integrally formed with this,
The gap 14 has the same shape as the ridge 13b having the same shape and filling the gap 14, and the outer surfaces of the connecting short pipes 9 and 10 and the opposite end 1 are respectively formed.
It is welded to the end faces of 1,12.

 Next, the function and effect of the connection pipe 5 of this embodiment will be described.

The heat and vibration from the engine 1 are absorbed mainly by the portion of the joint 13 of the connecting pipe 5 in the vicinity of the ridge 13b, and as a result, the transfer of heat and vibration to the carburetor 6 is greatly suppressed.
Also in the connecting pipe 5 of this embodiment, as in the case of the conventional one, the external load due to vibration or the like concentrates the stress near the ridges 13b located between the opposite ends of the joint 13. However, in the connecting pipe 5 of the present embodiment, since the opposite ends 11 and 12 are wavy, the end surface area, that is, the adhesion area with the convex portion 13b is smaller than that of the conventional straight pipe. The peel resistance is improved, the occurrence of cracks is suppressed, and the life can be improved.

Further, since the opposing end portions 11 and 12 have the corrugated shape, even if the crack A occurs in the convex portion 13b, the progress of the crack A is suppressed or prevented. That is, first, the crack A tends to propagate in the direction perpendicular to the axis of the connecting pipe 5, whereas the stress concentration occurs in a wavy shape, that is, along a shape that obliquely intersects the axis. Therefore, the directions of the two are different and the external load is dispersed, and from this point, the progress of cracks is suppressed. Secondly, in the present embodiment, one convex portion has a shape inserted into the other concave portion, and the metal portions are overlapped when viewed in the circumferential direction, and the progress of the crack A generated even in the worst case. Will be blocked at a position P that intersects this convex portion. These two points and the effect of increasing the adhesive area interact with each other, so that the durability of the connecting pipe 5 can be greatly improved and the life can be greatly extended.

It should be noted that, in the above-described embodiment, the case where one convex portion is inserted into the other concave portion and both of them are overlapped with each other has been described. There is no need to make it happen. Further, in the above embodiment,
Although the connection pipe for connecting the engine and the carburetor has been described, the connection pipe of the present invention can of course be applied to the connection of other connected objects.

〔The invention's effect〕

As described above, according to the connecting pipe of the present invention, the first, second
The opposite end of the connecting short pipe is one concave part, the convex part is the other convex part,
Since the corrugations are formed so as to face the recesses respectively, the peeling resistance of the elastic member can be improved, cracks can be suppressed from occurring, and the progress of cracks that have occurred can be prevented and the life can be extended.

[Brief description of drawings]

1 to 4 are views for explaining a connecting pipe according to an embodiment of the present invention, FIG. 1 is a sectional side view thereof, and FIGS. 2 (a) and 2 (b) are respectively second connecting members. Side view of short tube.
Front view. 3 and 4 are a plan view and a side view, respectively, showing a use state of the connection pipe of the embodiment, and FIG. 5 is a sectional side view of a conventional connection pipe. In the figure, 1 and 6 are an engine, a carburetor (connection target), and 5
Is a connecting pipe, 9 and 10 are first and second connecting short pipes, 11 and 12 are opposite ends, 11a and 12a are concave portions, 11b and 12b are convex portions, 13 is a joint (elastic member), and 13a is a covering portion. , 13b are ridges, and 14 is a gap.

Claims (1)

[Claims] 1. A tubular covering portion having first and second connecting short pipes arranged on the same axis line with a predetermined gap being adhered to outer peripheral surfaces of the both connecting short pipes, and the covering portion. A connecting pipe which is integrally formed and which is filled with the above-mentioned gap and is connected by an elastic member composed of a ridge portion adhered to the opposite end face of the connecting short pipe, wherein the two connected bodies are connected to each other. 1. A connecting pipe in which the opposite ends of the second connecting short pipe are formed in a corrugated shape in which one concave portion and a convex portion face the other convex portion and a concave portion, respectively.