JP2001342829A - Exhaust pipe connecting structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust pipe connecting structure of an internal combustion engine capable of preventing transmission of vibration and the like even if the connecting state between the exhaust pipes of the engine side and the muffler side is deformed. SOLUTION: A bolt 8 is passed through a penetrating hole formed in a flange 4 of the exhaust pipe 1 of the muffler side and fastened on a flange 5 of the exhaust pipe 2 of the engine side, a spring 9 is provided between the head part 8a of the bolt 8 and the flange 4 and both exhaust pipes are connected to each other with a seal ring interposed between them. A substantially semi- spherical receiving part 10 is formed on the peripheral edge of the penetrating hole of the flange 4. With the connection between both exhaust pipes bent, the spring 9 is smoothly moved along the contact position of the receiving part 10 to rectilinearly keep the axis of the spring. The spring 9 and the exhaust pipe 2 of the engine side become parallel so that load propagated from the exhaust pipe 2 of the engine side is always applied in the axial direction of the spring so as to smoothly elongate and contract the spring 9. Thus, the efficiency of reducing vibration can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In a four-wheeled vehicle, an engine is mounted by a mounting member, and an exhaust pipe is provided along a chassis. Therefore, an engine-side exhaust pipe and a muffler-side exhaust pipe are connected via a buffer means such as a spring. Connected.
The present invention relates to an exhaust pipe connection structure of an internal combustion engine for connecting exhaust pipes of different forms in a vehicle.

[0002]

2. Description of the Related Art An engine mounted on a vehicle is designed so that vibration during operation is not transmitted into the vehicle by a mount member. The intake pipe is attached to the engine, and the exhaust pipe is fixed to the chassis via a buffer member and connected to the engine. Therefore, as shown in FIG. 5, the connection structure between the muffler-side exhaust pipe 1 and the engine-side exhaust pipe 2 is hermetically connected by the seal ring 3.
The exhaust pipes 1 and 2 are pressed against each other by using the muffler-side flange 4 and the engine-side flange 5 formed at the connection end of the engine-side exhaust pipe 2.

[0003] An insertion hole 6 is formed in the muffler-side flange 4 of the exhaust pipes 1 and 2, and a screw hole 7 is formed in the engine-side flange 5, and the bolt 8 is fixed to the screw hole 7 through the insertion hole 6. I have. That is, the bolt 8 is attached to the engine-side exhaust pipe 2.
Are fixed in parallel. And the flange 4 on the muffler side
A spring 9 is inserted between the bolt 8 and the head 8a of the bolt 8, and is urged so that the flanges 4 and 5 approach each other. With this structure, the vibration transmitted from the engine is absorbed by the spring 9 and the like. However, when the vibration is large, vibration or flutter occurs between the flanges 4 and 5 and the seal ring 3, which may cause abnormal noise or unpleasant vibration.

For this reason, the spring is formed by forming the outer shape of the spring into a substantially conical shape (Japanese Utility Model Application Laid-Open No. 57-14801).
Japanese Patent Application Laid-Open No. 5-52218), and a device in which a reverse biasing spring is added (see Japanese Utility Model Laid-Open No. 5-52218) suppresses the above-described vibration and flutter.

[0005]

By the way, the above-mentioned structure is effective for preventing the vibration of the engine or the like from propagating. However, depending on the inclination of the engine and the large run-out of the exhaust pipe during operation, there are some problems. As shown in FIG. 6, the exhaust pipes 1 and 2 vibrate at an angle without vibrating on a straight line. As a result, the axes of the exhaust pipes 1 and 2 cross each other, and the corresponding surfaces of the flanges 4 and 5 also form an angle, and the support surfaces at both ends of the spring 9 are not parallel. Therefore, a load in the shear direction is generated at the axis of the spring 9 and may be deformed as if bent, which is a factor of lowering the function of the spring 9 for reducing vibration.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exhaust pipe connection structure for an internal combustion engine that maintains the function of a spring at a connection point even when the connection state of the exhaust pipe is deformed.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a first exhaust pipe having a first flange at a connection end and a second exhaust pipe having a first flange at a connection end are provided. A second exhaust pipe having a second flange, a first exhaust pipe and a second exhaust pipe.
Are connected to each other with a seal ring interposed therebetween, and a bolt is screwed into the second flange through an insertion hole formed in the first flange. An elastic member is interposed between the insertion hole and a directional receiving portion formed on the periphery of the insertion hole. Here, the elastic member has a spiral shape and is inserted into the bolt. The directional receiving portion is formed on the periphery of the insertion hole, abuts against the end of the elastic member, and stably expands and contracts the elastic member in the axial direction. Further, the second exhaust pipe is on the vibration source side.

According to a second aspect of the present invention, a first exhaust pipe having a first flange at a connection end and a second exhaust pipe having a second flange at a connection end are provided with a first exhaust pipe. Flange and second
Are connected to each other with a seal ring interposed therebetween, a gasket is provided on the non-connection side of the first flange, an insertion hole is opened in the first flange and the gasket, and a bolt is inserted through the insertion hole. And an elastic member is interposed between the head of the bolt and a directional receiving portion formed on the periphery of the insertion hole of the gasket.

[0009] The invention of claim 3 is claim 1 or claim 2.
In the invention, the shape of the receiving portion is a substantially hemispherical convex shape.

[0010] The invention of claim 4 is claim 1 or claim 2.
In the invention, the shape of the receiving portion is substantially a truncated cone.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The present invention relates to a structure of a connecting portion of an exhaust pipe path connected by an exhaust pipe from an exhaust manifold to a muffler of an engine, and there is a connecting portion between an exhaust pipe and a muffler, and an exhaust pipe and an exhaust manifold. A connection structure between the exhaust pipes 1 and 2 shown in FIG. 1 will be described.

As shown in FIG. 1, the exhaust pipe 1 on the muffler side
Flanges 4 and 5 are formed at respective connection ends of the (first exhaust pipe) and the engine-side exhaust pipe 2 (second exhaust pipe), and an insertion hole 6 and an engine-side flange 5 are formed in the muffler-side flange 4. A plurality of screw holes 7 are formed symmetrically.
The bolt 8 is fixed to the screw hole 7 through the insertion hole 6 and is parallel to the exhaust pipe 2 on the engine side. A directional receiving portion 10 is formed on the periphery of the insertion hole 6 formed in the flange 4 on the muffler side. It is interposed between them. Then, connect the spring 9 to the flanges 4 and 5
The exhaust pipes 1 and 2 are urged so as to approach each other (so that the exhaust pipes 1 and 2 are pressed against each other). Also, the exhaust pipe 2 on the engine side
Are inserted through the exhaust pipe 1 on the muffler side and are hermetically connected by a seal ring 3.

As shown in FIG. 1, the receiving portion 10 formed on the flange 4 on the muffler side is formed by pressing the flange portion to form a substantially hemisphere convex on the spring 9 side. It comes into contact with the circular end of the spring 9.

In such a connection structure, generally, the circular end of the spring 9 is engaged with the substantially hemispherical peripheral surface of the receiving part 10 at an equal position symmetrical with respect to the axis. Exhaust pipes 1 and 2 caused by the inclination of the engine during operation of the vehicle and the swing of the exhaust pipe 2.
When the connecting portion 2 is deformed, the circular end portion of the spring 9 and the substantially hemispherical peripheral surface of the receiving portion 10 allow the receiving portion 10
Changes the contact angle smoothly with respect to the spring 9 (see FIG. 2). Thereby, the engagement portion between the receiving portion 10 of the flange 4 and the spring 9 moves forward or backward of the bolt 8 to maintain the axis of the spring 9 in a straight line. The linear axis of the spring 9 and the axis of the exhaust pipe 2 on the engine side are parallel to each other, and the load applied to the spring 9 is always applied in the axial direction of the spring 9, thereby improving the efficiency of vibration reduction.

Next, another embodiment will be described. As shown in FIG. 3, what differs from the above embodiment is that
This is the shape of the receiving portion 11 of the flange 4. Here, receiving part 1
1 is formed into a substantially truncated cone, and its outer peripheral surface is engaged with the spring 9. Also in this configuration, the load applied to the spring 9 due to the inclination of the engine during the operation of the vehicle and the deformation of the exhaust pipe connection due to the deflection of the exhaust pipe 2 can always be applied in the spring axial direction. In addition, the spring 9 and the bolt 8 can be adjusted only by adjusting the height of the receiving portion 11 of the substantially truncated cone.
Can easily be adapted to the difference in the size of.

Further, another embodiment will be described. In the present embodiment, instead of “forming the flange 4 to form the receiving portion 10 (11)” as described above, FIG.
As shown in (a), a gasket 12 is provided on the flange 4 and a substantially hemispherical receiving portion 13 is formed on the gasket 12. In this configuration, as described above, the spring 9 can be maintained in a linear shape, and can always respond vertically to an input load. Gasket 1
Since the receiving portion 13 is formed on the two sides, even when a plurality of springs 9 having different diameters are used, the gasket 12 can be easily replaced and processed.

In another embodiment shown in FIG. 4 (b), a gasket 12 is
A receiving portion 14 having a substantially frustoconical shape is formed on the receiving portion. With this configuration, of course, the function of the spring 9 is maintained,
It is easy to form the receiving portion 14 according to the size of the spring 9.

[0018]

The present invention is as described above. According to the first aspect of the present invention, when the vibration is propagated in a state where the connection between the first exhaust pipe and the second exhaust pipe is bent, the first Although a bending angle occurs between the first and second flanges, since the axis of the elastic member is maintained in a straight line by the directional receiving portion,
The linear axis of the elastic member and the axis of the second exhaust pipe are parallel to each other, and the load transmitted from the second exhaust pipe is always applied in the axial direction of the elastic member, and the elastic member is smoothly expanded and contracted. The efficiency of vibration reduction is improved. According to a second aspect of the present invention, in addition to the first aspect of the present invention, a gasket is provided on the flange on the side where the insertion hole is formed, and a directional receiving portion is formed on the gasket. The expansion and contraction of the elastic member is performed smoothly, so that the efficiency of vibration reduction is improved, and when a different elastic member is mounted, it can be easily dealt with only by replacing the gasket.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the receiving surface is formed in a substantially hemispherical shape, so that the engagement surface with the elastic member can be smoothly moved. It is possible to maintain the axis of the elastic member straight,
The linear axis of the elastic member and the axis of the second exhaust pipe on the vibration side can be made parallel. In the invention according to claim 4,
According to the first or second aspect of the present invention, by forming the receiving portion into a substantially truncated cone shape, the receiving portion can be easily processed and formed, and a different elastic member can be mounted on the flange. In particular, in the case where a gasket is additionally provided and the receiving portion is formed on the gasket, since the gasket is simply replaced, the assembling work is simple.

[Brief description of the drawings]

FIG. 1 is a side view of an exhaust pipe connection structure of an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a side view showing a state of the exhaust pipe connection structure shown in FIG. 1 at the time of vibration.

FIG. 3 is a side view of an exhaust pipe connection structure of an internal combustion engine according to another embodiment.

FIG. 4 is a main part side view showing a flange of an exhaust pipe showing (a) a substantially hemispherical receiving portion and (b) a substantially frustoconical receiving portion of still another embodiment.

FIG. 5 is a side view of a conventional exhaust pipe connection structure for an internal combustion engine.

6 is a side view showing a state of the exhaust pipe connection structure shown in FIG. 5 at the time of vibration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st exhaust pipe 2 2nd exhaust pipe 3 Seal ring 4 1st flange 5 2nd flange 6 Insertion hole 7 Screw hole 8 Bolt 8a Head 9 Elastic member 10, 11, 13, 14 Receiving part 12 Gasket

Claims (4)

[Claims] A first end provided with a first flange at a connection end;
The first exhaust pipe and the second exhaust pipe having a second flange at a connection end are connected to each other with the first flange and the second flange facing each other and a seal ring interposed therebetween. A bolt is screwed into the second flange through an insertion hole formed in the flange, and an elastic member is interposed between a head of the bolt and a directional receiving portion formed on the periphery of the insertion hole of the first flange. An exhaust pipe connection structure for an internal combustion engine, wherein the exhaust pipe connection structure is inserted. 2. A first connector having a first flange at a connection end.
The first exhaust pipe and the second exhaust pipe having a second flange at a connection end are connected to each other with the first flange and the second flange facing each other and a seal ring interposed therebetween. A gasket is provided on the non-connection side of the flange, an insertion hole is opened in the first flange and the gasket, and a bolt is passed through the insertion hole and screwed to the second flange. An exhaust pipe connection structure for an internal combustion engine, wherein an elastic member is interposed between the insertion portion and a directional receiving portion formed on the periphery of the insertion hole. 3. The exhaust pipe connection structure for an internal combustion engine according to claim 1, wherein the receiving portion has a substantially hemispherical convex shape. 4. The exhaust pipe connection structure for an internal combustion engine according to claim 1, wherein the shape of the receiving portion is a substantially frustoconical convex shape.