KR20020082746A - Inner and outer two passage type of exhaust pipe - Google Patents

Abstract

PURPOSE: To prevent a chattering sound in an exhaust pipe of inner-outer double-tube type exhaust pipe caused by wear generated between a separate protrusion and its contact part due to long-time use. CONSTITUTION: An inner-outer double-tube type structure is provided by constituting an exhaust pipe 1 of an outer pipe 10 and an inner pipe 11 coaxially arranged inside it, and at its rear end, a separate protrusion 15 is protruded inward from the outer pipe 10 and brought into contact with the inner pipe 11, and the inner pipe 11 is made capable of sliding. The separate protrusion 15 is provided in plural in the circumferential direction, and a suppressing member 18 is slightly pressed into a clearance 17 of an outward projection 16 formed between the adjacent separate protrusions 15 and plug welded to the outer pipe 10.

Description

Internal and external double pipe exhaust pipe {INNER AND OUTER TWO PASSAGE TYPE OF EXHAUST PIPE}

TECHNICAL FIELD The present invention relates to an internal and external double pipe exhaust pipe used for a motorcycle and the like, and more particularly, to prevent a squeaking sound even when used for a long time.

The exhaust pipe connecting the engine to the muffler has an internal and external double pipe structure, and at the rear end thereof, separate projections projecting radially inward from the rear end are formed, and the separate projections are brought into contact with the inner pipe to maintain the inner pipe at a predetermined distance from the outer pipe. It is known that the inner tube is slidably contact-supported in order to allow relative movement of the inner tube with respect to the appearance by extension by thermal expansion (hereinafter referred to as thermal extension) (Japanese Patent Laid-Open No. 11). -303632).

However, even in the above structure, long-term use causes a small wear gap between the separate projections and the inner tube due to abrasion, which causes the inner tube to self-excited and generate a squeaking sound. have. Therefore, an object of the present invention is to effectively prevent the occurrence of such squeaking sound.

In order to solve the above problems, the internal and external double pipe exhaust pipes according to the present invention are provided with a plurality of separate protrusions projecting from one of the outer or inner pipes to the other in the circumferential direction at predetermined intervals, and the inner pipes are separated by the separate protrusions. In the inner and outer double-pipe exhaust pipe which is maintained inside the exterior at predetermined intervals and slidably supports the contact counterpart at the contact portion of the separate projection,

In the gap formed in the said inner and outer tube, the suppression member for contact | adhering the said inner tube to the said separator protrusion is press-fitted, It is characterized by the above-mentioned.

At this time, the separate projection may be formed from the outer side toward the inner tube, and the restraining member may be fixed to the outer side by welding.

1 is a side view of a motorcycle to which the inside and outside double pipe exhaust pipe of the present invention is applied.

Figure 2 is a side view of the inner and outer double pipe exhaust pipe.

3 is a cross-sectional view taken along line 3-3 of FIG.

4 is a cross-sectional view taken along line 4-4 of FIG. 3.

5 is a view showing a welded portion of the suppression member.

6 is an enlarged cross-sectional view illustrating the welding structure.

Fig. 7 is a diagram relating to the second embodiment.

8 is a diagram relating to the third embodiment.

9 is a diagram relating to the fourth embodiment.

<Description of the symbols for the main parts of the drawings>

1: exhaust pipe 2: engine

3: muffler 10: appearance

11: inner tube 15: separate projection

16: outer projection 17: gap

18: suppression member

Hereinafter, a first embodiment will be described with reference to the drawings. 1 is a side view of a two-wheeled vehicle employing the internal and external double pipe exhaust pipe of the present embodiment, FIG. 2 is a side view of an exhaust system apparatus including the internal and external double pipe exhaust pipe of this embodiment, FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 3 is a sectional view taken along line 4-4 of FIG. 3, FIG. 5 is a view showing a welded portion of the suppression member, and FIG. 6 is an enlarged sectional view showing the weld structure.

As shown in FIG. 1, the exhaust pipe 1 connects an exhaust upstream end (hereinafter referred to as a front end) to the exhaust port of the engine 2, and a portion extending therefrom is from the front of the engine 2 to the bottom thereof. The exhaust gas downstream of the engine 2 (hereinafter referred to as the rear end) is connected to the muffler 3, the exhaust gas of the engine 2 flows into the muffler 3, and the vehicle body here. It is to be discharged to the rear space.

The reference numeral 4 in the figure is a head pipe, 5 is a body frame, 6 is a pivot shaft, 7 is a rear end supported by the pivot shaft 6 so as to be slidable to the body, and supports a rear wheel, not shown at the rear end. The rear swing arm 8 is a rear cushion unit installed between the body frame and the rear swing arm.

In FIG. 2, the exhaust pipe 1 forms a double tube structure between the outer tube 10 and the inner tube 11. A flange 12 is provided at the front end of the exhaust pipe 1 and attached to the exhaust port of the engine 2. The rear end of the exhaust pipe 1 is fitted to the joint pipe 13 and connected.

The joint pipe 13 extends the inside of the muffler 3 to the exhaust downstream side, and the exhaust gas flows into the vehicle body portion of the muffler 3. On the connecting portion of the exhaust pipe 1 and the joint pipe 13, a narrow diameter portion 14 formed on the front end side of the muffler 3 is covered, and welded to the outer surface of the exterior 10 together with the joint pipe 13.

3 and 4, the outer tube 10 and the inner tube 11 each have a round pipe shape made of a suitable metal such as iron, and the inner tube 11 with respect to the outer tube 10 has a predetermined gap therein. It is arranged substantially concentrically to hold (D), and the separate projection 15 for holding it concentrically protrudes toward the inner tube 11 from the exterior 10 at the rear end of the exhaust pipe 1.

The separate projection 15 is formed by integrally protruding the rear end portion of the outer casing 10 radially inwardly by press molding and supporting the outer periphery of the inner tube 11. In the present embodiment, the circumferential direction of the outer casing 10 is supported. Four are formed at equal intervals, and the protruding height is almost the same as the clearance gap D between the exterior 10 and the inner tube 11. Moreover, the contact part with respect to the inner pipe | tube 11 of the separate protrusion 15 is made to be slidable in order to enable the expansion and contraction of the inner pipe | tube 11 by thermal expansion.

As can be seen in FIG. 4, the outer tube 10 and the inner tube 11 are integrated at the separate protrusions 15 at the rear end, but the inner tube 11 is concentrically arranged inside the outer tube 10 at the front. The predetermined interval D is maintained.

As can be seen in FIG. 3, the adjacent projections 15 and 15 form an outer projection 16 that projects radially outward from the inner tube 11 side, and a gap 17 is formed therein. Is formed. The outer protrusion 16 is an expression when the outer tube 10 is seen from the inner tube 11 side, and is a portion remaining as the non-molded portion when the separate protrusions 15 are formed among the rear ends of the outer tube 10. Accordingly, the outer circumferential portion of the outer protrusion 16 is the original outer diameter portion of the outer casing 10, and the gap 17 has a radial width in a predetermined interval D.

The suppressing member 18 is press-fitted into any one of these gaps 17, and the plug 19 is plug welded to the outer protrusion 16. The suppressing member 18 is made of a suitable metal material such as iron, and the thickness T thereof is slightly larger than the radial width of the gap 17, that is, the predetermined distance D between the outer tube 10 and the inner tube 11. It is set so that it is press-fitted with a light indentation that is enough to tap with a hammer.

As can be seen in FIGS. 4 and 6, the end pressed against the end of the suppression member 18 is formed in a thin shape for facilitating the press, such as an R shape or a tapered shape, and as shown in FIG. 5. And having a length slightly shorter than the length of the separate projection 15, and as shown in FIG. 3, it is bent in an arc shape so as to be in sliding contact with the outer circumference of the inner tube 11.

5 is a view showing the separate projection 15 and the suppression member 18 of the outer appearance 10 in the direction of the Y arrow of FIG. 4, wherein the suppressing member 18 is the outer projection 16 that is the rear end of the outer appearance 10. The plug 10 is welded to the exterior 10 through the plug 19 inserted into the through hole 20 formed in FIG. 6A is a cross-sectional view taken along line 6-6 of FIG. 5 schematically showing this weld structure.

The restraint member 18 is not limited to plug welding, but other suitable welding methods are also possible. FIG. 6B is fillet welding the cross section of the suppression member 18 and the external appearance 10. FIG. Even in this way, there is no problem as long as the weld bead does not reach the inner tube 11, and the sliding member 18 and the inner tube 11 can be moved.

Next, the operation of the embodiment of the present invention will be described. As shown in FIG. 3, the inner tube 11 is pushed onto the opposite projection 15 on the opposite side with some elastic deformation by press-fitting the suppression member 18 into the gap 17. In this state, when the inner tube 11 extends relative to the outer appearance 10 by thermal elongation, the inner tube 11 slides with respect to the separate projection 15 and the suppressing member 18, and when cooled, contracts and also slides.

Therefore, when it is used for a long time, the contact portion between the separate projection 15 of the inner tube 11 and the suppressing member 18 wears out, but even if such wear occurs, the inner tube 11 is press-fitted into the gap 17 in advance to pressurize the inner tube 11. The inner tube 11 is pushed by the separate projections 15 by the suppressing member 18 to maintain contact. For this reason, abrasion gap does not generate | occur | produce between the inner pipe | tube 11 and the separate protrusion 15, and does not generate the self-vibration of the inner pipe | tube 11, and prevents the generation of the squeaky sound which might have arisen by long-term use. can do.

In addition, by forming the separate projections 15 integrally with the external appearance 10, the separate projections 15 can be easily formed. In addition, it is possible to prevent a squeaking sound with a simple structure only by injecting one suppression member 18 into the gap 17 generated by the formation of the separate projection 15.

In addition, since the restraining member 18 is fixed to the external appearance 10 by plug welding, the restraining member 18 is sufficient by light indentation, and assembling work becomes easy. Moreover, positioning can be reliably carried out by plug-welding the suppression member 18 to the exterior 10 side, and the exterior 10 can be fitted inside the joint pipe 13, without special post-processing, and the inner pipe Since no welding traces remain on 11 and the sliding surface, there is no need to perform special post-processing on the sliding surface of the restraining member 18 in order to secure the sliding movement of the inner tube 11.

FIG. 7 is a view showing the same parts as FIG. 3 according to the second embodiment. In this example, three separate projections 15 are formed at equal intervals in the peripheral direction, and as a result, the suppression member 18 is press-fitted into any one of the three formed gaps 17. The structure and fixing structure of the suppressing member 18 are the same as in the above embodiment (not shown in the weld section). In addition, the common part with the said embodiment uses a common code | symbol. The following examples are also the same.

Fig. 8 relates to the third embodiment, in which the exterior 10 and the inner tube 11 are the same as in the first embodiment (Fig. 3), but in this embodiment the restraining members in two adjacent gaps 17 and 17 are shown. (18, 18) is press-fitted. In this way, the inner tube 11 can be inserted in the center thereof and pressed more strongly to the separate projections 15 and 15 located on the opposite side to the suppressing members 18 and 18.

FIG. 9 shows a fourth embodiment, in which the two separate projections 15 are formed at 180 ° intervals at opposite positions in the center of the exterior 10. However, this separate projection 15 is bent so as to protrude radially inwardly and protrudes inwardly from the inner diameter R11 of the inner tube 11, and the portion of the inner tube 11 corresponding thereto is also larger than the inner diameter R11. It is formed with the curved part 21 recessed inward, and the separate protrusion 15 and the curved part 21 are in close contact.

The outer protrusions 16 and the gaps 17 are disposed opposite to the separate protrusions 15 in a pair of 180 ° intervals at positions different from the separate protrusions 15, respectively, and the suppressing members 18 in each of the gaps 17 and 17 are provided. 18) is press-fitted. R10 is the outer diameter of the exterior 10, and the inner tube 11 is concentrically arrange | positioned inside the exterior 10 at predetermined intervals except the rear end which formed the separate protrusion 15 similarly to the former example.

In this manner, the separate projections 15 and the curved portions 21 can improve the close contact between the exterior 10 and the inner tube 11, and the restraining members 18 and 18 disposed to face each other even after long-term use. By this, since the separated protrusions 15 and 15 and the curved parts 21 and 21 which are opposed to each other can maintain close contact, it can prevent a squeaking sound similarly to each said embodiment.

In addition, this invention is not limited to the said Example, A various deformation | transformation and application are possible within the same invention principle. For example, the use of the exhaust pipe is not limited to motorcycles, but can be applied to automobiles and other engines. The number of use of the suppression member 18 is not restrict | limited, if it is one or more, As shown in each said embodiment, it can press in all or part of the clearance gap 17. FIG. In addition, the material is not limited to metal, and can be used as long as it has a certain degree of hardness, durability, and heat resistance. The degree of indentation includes a variety of things, such as direct indentation by hand or light indentation by a manual tool such as a hammer to indentation by large pressure by a power unit. Moreover, you may fix the restraining member 18 with respect to the inner tube 11, and a fixing method is not limited to welding either.

In addition, formation of the separate protrusion 15 is not limited to the outer side 10 side, but may be provided in the inner tube 11 side. In addition, the separate projections 15 may be formed separately from the exterior 10 and the inner tube 11. In this case, it is preferable to fix the separate projection to either the exterior 10 or the inner tube 11.

When the suppression member is press-fitted into the gap between the outer tube and the inner tube, the inner tube is strongly pressed by the separate projection by the suppressor member. When used for a long time in this state, even if abrasion occurs between the separate projection and the contacting partner, the inner tube and the separate projection are kept in close contact by the pressurization of the restraining member, so that the inner tube does not generate a vibration, and as a result, The generation of sound can be prevented.

At this time, when the suppressing member is welded to the outer appearance, the suppressing member can be reliably positioned, and the press-in of the suppressing member can be simplified. Moreover, since no welding trace remains on the sliding surface, there is no need to perform special post-processing on the sliding surface of the suppressing member in order to secure the sliding movement of the inner tube.

Claims (2)

The inner and outer double pipe structure is provided, and a plurality of separate protrusions protruding from one of the outer or inner pipes to the other side are provided at predetermined intervals in the circumferential direction. In the inner and outer double-pipe exhaust pipe which is supported by the contact portion of the separate projection to be slidable, An internal and external double tube exhaust pipe, wherein a restraining member for pressing the inner tube into close contact with the separate projection is pressed into a gap formed in the inner and outer tubes. The method of claim 1, The separate projection is formed from the outer side toward the inner tube, and the suppression member is fixed to the outer tube by welding, the inner and outer double pipe exhaust pipe.