JPH0547349Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the improvement of exhaust pipe joints used in vehicles, particularly plug-in type exhaust pipe joints.

[Conventional technology]

Conventionally, plug-in type exhaust pipe joints used in vehicles such as automobiles and motorcycles fit a cylindrical gasket onto the outer circumferential surface of an inner pipe, fit an outer pipe onto the outer circumferential surface of this gasket, and then connect the pipe between the inner and outer pipes. In order to improve the sealing performance of the outer tube, a type is known in which the outer circumferential surface of the outer tube is tightened with a tightening tool such as a band.

Gaskets used in this type of exhaust pipe joint include, for example, gaskets made of metal plates (Utility Model Application Publication No. 52-29305), as well as gaskets made by overlapping metal plates and asbestos and winding them into a cylindrical shape. Alternatively, a solid lubricant such as graphite powder may be applied to the inner and outer peripheral surface of the sleeve obtained by winding the sleeve in this manner to prevent slipping and sticking.

Plug-in type exhaust pipe fittings using such gaskets have advantages over other types, such as flange types, such as requiring less installation space and being easier to assemble. However, it has the drawback that it does not have sufficient ability to absorb vibrations and heat generated by the internal combustion engine of a vehicle, and exhaust gas leaks from the joint.

Therefore, the present applicant previously proposed an exhaust pipe joint that solved the above-mentioned conventional problems in Japanese Patent Application No. 60-84389 (Japanese Unexamined Patent Publication No. 61-244815: referred to as "prior art").

That is, the above prior art includes an inner tube, an outer tube,
In an exhaust pipe joint consisting of a cylindrical gasket inserted between them, the inner pipe has an annular pipe protruding radially outward with a certain length left in the axial direction near the opening at the end of the pipe. A flange is provided, and the outer tube is provided with an enlarged diameter portion along a certain length in the axial direction at the tube end portion, and this enlarged diameter portion is connected to the opening and is divided into several pieces in the axial direction. A slit is provided, and the length of the gasket is approximately equivalent to the length between the flange of the inner tube and the base of the expanded diameter portion of the outer tube. A tightening band having an inner diameter corresponding to the outer diameter of the part and having a cut in the axial direction is arranged,
This exhaust pipe joint uses this tightening band to tighten a gasket inserted into the gap formed between the inner pipe and the enlarged diameter portion of the outer pipe so that one end contacts the flange of the inner pipe. .

In the exhaust pipe joint having the above configuration, by using a cylindrical gasket made of expanded graphite and a reinforcing material such as a wire mesh, the gasket is able to vibrate due to the flexibility and bendability of the expanded graphite. It exhibits absorption capacity and causes accumulation expansion due to the heat of the exhaust gas flowing in the inner pipe, closing the gap where the gasket is placed and improving the sealing function, solving the above-mentioned drawbacks of the conventional exhaust pipe joint. It was something to do.

[Problems to be solved by the invention] The exhaust pipe joint of the prior art described above solves the drawbacks of conventional exhaust pipe joints, but
If the exhaust pipe joint is applied as is to a four-wheeled vehicle, the relative axial displacement and relative rotational displacement in the circumferential direction of the inner and outer pipes will be large, and such displacement will not be tolerated, and the sealing performance of the gasket portion will be impaired. A new problem has been discovered: increased leakage of exhaust gas.

The purpose of the present invention is to obtain an exhaust pipe joint that can be applied to four-wheeled vehicles in which the relative axial displacement and circumferential rotational displacement of the inner and outer pipes are large, while making full use of the advantages of the above-mentioned prior art. That is.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention adopts the following configuration (technical means).

That is, it is an exhaust pipe joint consisting of an inner pipe, an outer pipe, and a cylindrical gasket fitted and inserted between them, and the inner pipe has a length in the axial direction near the opening at the end of the pipe. An annular flange that protrudes outward in the radial direction leaving behind is fixedly provided, and at least one engagement recess is formed on the outer circumferential surface of the annular flange. The outer tube has an enlarged diameter tube section having a certain length in the axial direction near the opening at the end of the tube, and the enlarged diameter tube section has several tubes extending in the axial direction from the opening. Slits are formed in several tongue portions in the circumferential direction thereof, and at least one tongue portion is formed with an engaging through hole. The outer tube is fitted onto the outer circumferential surface of the end of the inner tube by aligning the engaging through hole of the enlarged diameter tube portion with the engaging recess on the outer circumferential surface of the annular flange fixed to the inner tube. thing. A cylindrical gasket is fitted and held within an annular gap formed between the outer circumferential surface of the tube end of the inner tube and the inner circumferential surface of the enlarged diameter tube portion of the outer tube, with one end abutting the annular flange. thing. A tightening band is formed on the outer circumferential surface of the enlarged diameter tube portion of the outer tube, and an engagement protrusion integrally formed on the inner surface thereof is connected to an engagement recess on the outer circumferential surface of the annular flange fixed to the inner tube. It is arranged so as to fit across the matching through hole of the enlarged diameter tube section of the outer tube, and is fixed by tightening the tube end of the inner tube, the cylindrical gasket, and the enlarged diameter tube section of the outer tube. Doing things. This is an exhaust pipe joint characterized by the above configuration.

[Embodiments] Hereinafter, the present invention will be described in detail based on FIGS. 1 to 6 of the accompanying drawings showing embodiments thereof.

In the figure, 1 is an inner tube, and an annular flange 3 is fixed to the inner tube 1 near the opening of the tube end 2 and projects radially outward with a certain length left in the axial direction. There is. In the embodiment shown in FIG. 1, this annular flange 3 is fixed by fitting a ring onto the outer peripheral surface of the inner tube 1 and pressing it radially outward, but such means are not necessarily required. For example, it may be fixed by a method such as welding. Since the end surface of this annular flange 3 on the opening side of the inner tube 1 becomes the abutting part of a cylindrical gasket described later, an accurate perpendicularity between the end surface of the annular flange 3 and the outer peripheral surface of the inner tube 1 is required. .

Reference numeral 4 denotes an engagement recess formed on the outer peripheral surface of the annular flange 3 so as to face each other.

Reference numeral 5 denotes an outer tube having an inner diameter substantially the same as the outer diameter of the inner tube 1, and the outer tube 5 has an enlarged diameter tube portion 6 of a certain length formed in the axial direction near the opening of its end, and an annular flange portion 7 extending radially outward is formed around the periphery of the opening.

Numeral 8 denotes several slits extending in the axial direction from the opening side of the enlarged diameter tube section 6, and the slits 8 allow the enlarged diameter tube section 6 to have several tongue pieces 9 in the circumferential direction.
is formed.

Reference numeral 10 denotes an engagement through hole formed in the tongue portion 9 so as to face each other.

The outer tube 5 is connected to the inner tube 1 by aligning the engagement through hole 10 formed in the enlarged diameter tube portion 6 with the engagement recess 4 on the outer peripheral surface of the annular flange 3 fixed to the inner tube 1. It is arranged so as to be fitted onto the outer peripheral surface of the end portion 2.

Reference numeral 11 denotes a cylindrical gasket, and the cylindrical gasket 11 is inserted into the annular gap S formed between the outer circumferential surface of the tube end 2 of the inner tube 1 and the inner circumferential surface of the enlarged diameter tube portion 6 of the outer tube 5. One end thereof is fitted and held in contact with the annular flange 3.

The cylindrical gasket 11 is made of expanded graphite and reinforcing material.

The expanded graphite used for this gasket 11 is obtained by significantly expanding graphite in the direction of its crystal C axis, and its specific manufacturing technology is described in U.S. Patent No. 1137373 and Japanese Patent Publication No. It is disclosed in Publication No. 44-23966, etc.

This expanded graphite powder can be easily manufactured into thin plates or blocks by pressurizing it without using a binder, and the resulting shaped objects are different from ordinary graphite. It is flexible and bendable.

In addition, perforated metal plates, expanded metal, wire mesh, etc. are used as reinforcing materials, but in particular, wire mesh obtained by knitting or weaving fine stainless steel wires is difficult to form when combined with expanded graphite and made into a molded product. It is the most preferable material to be used in the present invention because it is not only difficult to impart directionality to objects, but also has high strength due to the entanglement of fine wires.

The gasket 11 having such a composition or characteristics is usually made by overlapping a sheet made of the above-mentioned expanded graphite and a reinforcing material made of wire mesh, and then winding the sheet in a mold in the direction of the winding axis. It is compression molded at a pressure of several 100 kg to 3 tons per square centimeter to form a cylindrical shape.

The cylindrical gasket 11 formed in this manner is disposed between the inner and outer tubes 1 and 5 and exhibits vibration absorbing ability due to the flexibility and bendability of the expanded graphite forming the gasket. Outer tube 1,
The heat of the exhaust gas flowing through the gasket 1 causes volumetric expansion, and this volumetric expansion occurs because the radial direction of the gasket 11 is restrained by the inner tube 1 and the outer tube 5, respectively. This appears as expansion in the axial direction, tightly closing the annular gap S in which the gasket 11 is disposed, and improving sealing performance.

12 is a tightening band, and the tightening band 1
2 has a substantially cylindrical shape, and has a cut 13 along its axis, and ears 14a, 14b projecting outward in the radial direction from each surface of the cut 13.
is formed.

One of these ears 14a has a nut 1 having a through hole 15 and a female threaded portion communicating with the through hole 15.
6 is fixed, and a long hole 17 is formed in the other ear portion 14b at a position facing each other.

Reference numeral 18 denotes an engaging protrusion integrally formed opposite to the inner surface of the tightening band 12.

In the embodiment, the engagement protrusion 18 is formed by integrally forming a cylindrical plug on the inner surface of the tightening band 12. However, the engagement protrusion 18 is not limited to this structure. The engaging protrusion may be formed by press molding.

Reference numeral 19 indicates ears 14a, 14 of the tightening band 12.
It is a folded part formed near b, and the corresponding ear part 1
4a and 14b are reinforced.

The tightening band 12 has an engaging protrusion 18 integrally formed on its inner surface with an engaging recess 4 on the outer peripheral surface of the annular flange 3 fixed to the inner tube 1 and the outer tube that matches the engaging recess 4. The male threaded portion at one end is screwed into the nut 16 fixed to the ear portion 14a, and the other end is fitted over the engagement through hole 10 of the enlarged diameter tube portion 6 of No.5. A tightening bolt 20 inserted through the elongated hole 17 of
It is tightened and fixed.

In this way, the tightening band 12 allows the engagement protrusion 18 integrally formed on the inner surface of the band 12, the engagement recess 4 on the outer peripheral surface of the annular flange 3 fixed to the inner tube 1, and the engagement recess 4, the relative axial displacement and circumferential relative rotational displacement of the inner and outer tubes 1 and 5 are restrained by fitting the outer tube 5 into the engagement through hole 10 of the enlarged diameter tube portion 6. .

〔effect〕

The exhaust pipe joint configured as described above has the following unique effects.

The tube end portion of the inner tube and the enlarged diameter tube portion of the outer tube are fixed by a tightening band via a cylindrical gasket, and an engaging protrusion formed integrally with the tightening band is attached to the outer circumferential surface of the inner tube. It is fitted across an engagement recess on the outer circumferential surface of an annular flange fixedly fixed to the annular flange, and an engagement through hole in an enlarged diameter tube portion of an outer tube arranged in alignment with the engagement recess, and the inner ,
Since the relative axial displacement and relative rotational displacement in the circumferential direction occurring in the outer tube are restrained, there is no reduction in sealing performance due to these displacements.

The above enables application to exhaust pipe joints of four-wheeled vehicles.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the exhaust pipe joint of the present invention, Fig. 2 is a sectional view taken along line I-I in Fig. 1, and Fig.
The figure is a vertical sectional view showing the outer tube, Figure 4 is a front view of the outer tube, Figure 5 is a partially cutaway plan view showing the inner tube, and Figure 6 is a partially cutaway plan view showing the inner tube.
The figure is a sectional view showing the tightening band. DESCRIPTION OF SYMBOLS 1... Inner tube, 3... Annular flange, 4... Engaging recess, 5... Outer tube, 6... Expanded diameter tube part, 8... Slit, 10... Engaging through hole, 11... Cylindrical shaped gasket, 12... tightening band, 18... engaging protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] An exhaust pipe joint consisting of an inner pipe, an outer pipe, and a cylindrical gasket fitted and inserted between them, wherein the inner pipe has a gasket near the opening at the end of the pipe. An annular flange that protrudes outward in the radial direction leaving a certain length in the axial direction is fixed, and at least one engagement recess is formed on the outer peripheral surface of the annular flange. The outer tube has an enlarged diameter tube section having a certain length in the axial direction near the opening at the end of the tube, and the enlarged diameter tube section has several tubes extending in the axial direction from the opening. Slits are formed in several tongue portions in the circumferential direction thereof, and at least one tongue portion is formed with an engaging through hole. The outer tube is fitted onto the outer circumferential surface of the end of the inner tube by aligning the engaging through hole of the enlarged diameter tube portion with the engaging recess on the outer circumferential surface of the annular flange fixed to the inner tube. thing. A cylindrical gasket is fitted and held in an annular gap formed between the outer circumferential surface of the tube end of the inner tube and the inner circumferential surface of the enlarged diameter tube portion of the outer tube, with one end abutting the annular flange. thing. A tightening band is formed on the outer circumferential surface of the enlarged diameter tube part of the outer tube, and the engagement protrusion is integrally formed on the inner surface of the outer tube. The fitting is arranged to fit across the matching through hole of the enlarged diameter tube portion of the outer tube, and is fixed by tightening the tube end of the inner tube, the cylindrical gasket, and the enlarged diameter tube portion of the outer tube. Doing things. An exhaust pipe joint characterized by the above configuration.