JP4212914B2 - Exhaust pipe gasket and exhaust pipe joint provided with the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to an exhaust pipe joint used for vehicles such as ATVs, snow vehicles, motorcycles, etc., and more particularly to a plug-in type exhaust pipe joint, and an exhaust pipe gasket that is used for the joint and has a sealing performance such as prevention of exhaust leakage. It is.
[0002]
[Prior art]
As this type of plug-in type exhaust pipe joint, there is a conventional one shown in FIG. A gasket 50 is incorporated in the exhaust pipe joint. The exhaust pipe joint has an inner pipe 51 and an outer pipe 52 having an inner diameter formed slightly larger than the outer diameter of the inner pipe 51, and the outer pipe 52 has an enlarged diameter at the end of the pipe. A portion 53 is formed, and the inner tube 51 is inserted with the distal end portion extending through the enlarged diameter portion 53 of the outer tube 52 and extending to the inner diameter portion of the main body portion 54 of the outer tube 52. A gasket 50 is mounted in an annular space formed between the inner pipe 51 and the enlarged diameter portion 53 of the outer pipe 52, and the inner and outer pipes are clamped by a fastening band 55 disposed on the outer peripheral surface of the outer pipe 52. A clearance generated between the first and second members 51 and 52 is sealed.
[0003]
As shown in FIG. 11, the outer tube 52 is formed with an enlarged diameter portion 53 at an end thereof, and connects the main body portion 54 and the shoulder portion 56. On the other hand, a flange portion 58 is formed in the opening portion 57 by expanding the enlarged diameter portion 53 radially outward. Further, the enlarged diameter portion 53 is formed with slits 59 extending in the axial direction from the opening portion 57 at equal circumferences. The length is such that it reaches almost the entire length of the enlarged diameter portion 53.
[0004]
As shown in FIG. 12, the gasket 50 has a cylindrical shape, one end surface 60 contacts the flange 61 of the inner tube 51, and the other end surface 62 has a slight clearance on the inner peripheral surface of the shoulder portion 56 of the outer tube 52. Confronted. The outer peripheral surface 63 has an outer diameter that comes into contact with the inner peripheral surface of the enlarged diameter portion 53 of the outer tube 52.
[0005]
The gasket 50 is made of expanded graphite and a reinforcing material. Both end surfaces 60 and 62 and the outer peripheral surface 63 are covered with expanded graphite, and the inner peripheral surface 64 is made of a stainless steel mesh as a reinforcing material. Exposed. This expanded graphite is substantially equivalent to ordinary graphite in that it has heat resistance, chemical resistance, and a low coefficient of friction, but it can be easily molded by applying pressure without using a binder and is flexible. It has the characteristic that can be bent.
[0006]
As shown in FIG. 10, the gasket 50 is inserted between the inner and outer pipes 51, 52, the fastening band 55 is attached to the outer peripheral surface of the enlarged diameter part 53 of the outer pipe 52, and the bolt hole 66 of the ear part 65. By tightening the bolt 67, the tightening band 55 is tightened around the enlarged diameter portion 53, and the inner tube 51 and the outer tube 52 are sealed from the exhaust gas flowing inside them. Such a gasket 50 expands in volume by the heat of the exhaust gas flowing in the inner pipe 51 and has flexibility and flexibility, so that the gap 50 between the inner and outer pipes 51 and 52 adapts and adapts well. Sealability can be improved (for example, refer patent document 1).
[0007]
[Patent Document 1]
Japanese Examined Patent Publication No. 2-19286 (page 2-4, Fig. 1-4)
[0008]
[Problems to be solved by the invention]
However, in recent years, the exhaust pipe has become larger in size as a noise countermeasure, and a catalyst device has been installed as an exhaust gas countermeasure. As a result, an excessive load is applied to the gasket portion of the exhaust pipe joint as compared with the conventional case. I came. In particular, in an exhaust pipe joint such as ATV, a bounce is applied as the road travels on a rough road, and twisting or bending torque is repeatedly generated between the inner pipe 51 and the outer pipe 52.
[0009]
Due to such twisting and bending torque, the gasket 50 is plastically deformed, and not only the clearance between the inner and outer tubes 51 and 52 is expanded and the sealing performance is deteriorated, but also the bolt 67 of the fastening band 55 may be loosened. was there.
[0010]
The present invention has been made in view of such circumstances, and an object thereof is to provide a highly rigid exhaust pipe gasket and an exhaust pipe joint including the same without impairing the conventional sealing function.
[0011]
[Means for Solving the Problems]
In order to achieve such an object, the invention described in claim 1 of the present invention is a fastening band that is interposed in an annular space formed by inserting the end portions of the inner and outer tubes and is attached to the outer peripheral surface of the outer tube. In the cylindrical exhaust pipe gasket, the outer pipe is tightened via a seal and the joint is sealed, and a band-shaped inorganic material and a metal mesh material are polymerized, and the metal mesh is formed on the inner peripheral surface of the gasket. The inorganic material is wound so that it is exposed and the inorganic material is exposed on the outer peripheral surface. And polymerization of the metal mesh Stop the range from one end surface at the approximate center, Tighten the part composed only of the metal mesh with the fastening band, A configuration in which the formation range of the inorganic material was minimized and the metal mesh material having high rigidity was configured as a base was adopted.
[0012]
Thus, the metal mesh is exposed on the inner peripheral surface of the gasket, and the inorganic material is formed on the outer peripheral surface. And metal mesh polymerization Stop the range from one end surface at the approximate center, Tighten the part composed only of metal mesh with a tightening band, By minimizing the formation range of the inorganic material and configuring a highly rigid metal mesh material as the base material, it is possible to prevent the exhaust gas from leaking from the gap generated between the outer tube and the inner tube, Even if the inner and outer pipes are twisted or excessive bending torque is generated, it is flexible and highly flexible, minimizing the range of inorganic materials that have limitations in density, and suppressing plastic deformation due to tightening of the tightening band, A sufficient sealing function can be exhibited over a long period of time.
[0013]
Further, as in the invention described in claim 2, if the metal mesh material is wound in a plurality of spiral shapes and press-molded to a desired dimension, a gasket with high mass productivity can be provided. Rigidity can be made as high as possible, and it adapts and adapts well to the inner and outer pipes against excessive loads, and has a sufficient sealing performance for a long time.
[0014]
Preferably, as in the invention according to claim 3, by exposing the inorganic material with substantially the same width as the outer peripheral surface from the end surface of the gasket to the inner peripheral surface, the sealing performance of the joint portion of the inner and outer pipes is improved. This can be further improved.
[0015]
Further, as in the invention described in claim 4, since the sealing portion is made of expanded graphite having heat resistance and a low coefficient of friction, and the base material is knitted from a stainless steel wire having high mechanical strength, the sealing performance is improved. While maintaining, it is possible to provide a gasket having high rigidity and excellent durability.
[0016]
Preferably, in the invention described in claim 5, the surface of the inorganic material is further coated with a liquid inorganic material containing zirconia as a main component to form a thin film layer. Since this thin film layer has an elastic surface, the sealing function is improved, and the plastic deformation of the gasket is further suppressed even if the inner and outer pipes are twisted or an excessive bending torque is generated. A sealing function can be exhibited.
[0017]
In the invention according to claim 6, a thermally expandable inorganic material is disposed at least on the outer periphery between the wound layers of the metal mesh. From one end face of the tube to the center Formed Above Since it is interposed in the range of the inorganic material, even if the gasket is not firmly tightened with a tightening band or the like, the temperature of the gasket rises due to exhaust gas passing through the exhaust pipe, and the thermally expandable inorganic material itself expands to the original Therefore, the degree of adhesion between the gasket and the inner and outer pipes is remarkably increased. Therefore, not only the assembling property can be improved but also the sealing property can be further improved.
[0018]
The invention according to claim 7 of the present invention is provided in an annular space formed by inserting the end portions of the inner and outer pipes, and is connected to the outside through a fastening band attached to the outer peripheral surface of the outer pipe. In a cylindrical exhaust pipe gasket that tightens a pipe and seals its joint, a belt-like thermally expandable inorganic material and a metal mesh material are polymerized to expose the metal mesh on the inner peripheral surface of the gasket. In addition, the heat-expandable inorganic material is wound so that the heat-expandable inorganic material is exposed on the outer peripheral surface. And polymerization of the metal mesh Stop the range from one end surface at the approximate center, Tighten the part composed only of the metal mesh with the fastening band, The formation range of the thermally expandable inorganic material was minimized, and a configuration in which the metal mesh material having high rigidity was configured as a base was adopted.
[0019]
In this way, the main component unexpanded graphite expands due to temperature rise even if it is formed on the inner and outer peripheral surfaces of the metal mesh wrapped with this thermally expandable inorganic material instead of an inorganic material made of expanded graphite. In addition, since the exhaust pipe joint firmly adheres to the joint portion between the inner and outer pipes, a good sealing function can be exhibited.
[0020]
Moreover, since the said thermally expansible inorganic material consists of unexpanded graphite, a heat resistant fiber, and a heat resistant binder like invention of Claim 8, when the circumference | surroundings of a gasket heat up, this unexpanded Even if graphite expands suddenly and tries to scatter, it can be expanded while suppressing its expansion with a heat-resistant fiber made of an aramid fiber or the like that is entangled with a binder such as rubber.
[0021]
The invention according to claim 9 has an enlarged diameter portion at an end portion through a tapered shoulder portion, a flange portion extending radially outward at an opening portion of the enlarged diameter portion, and the enlarged diameter. An outer tube formed with slits extending in the axial direction of the circumferentially equidistant portion, and an outer diameter slightly smaller than the inner diameter of the outer tube, penetrating the enlarged diameter portion of the outer fitting, and the shoulder portion A cylindrical gasket is interposed in an annular space formed by the inner tube inserted beyond the tube, and a tightening band is externally inserted into the enlarged diameter portion of the outer tube, and the tightening band is reduced in diameter by a bolt. An exhaust pipe gasket in which the inner and outer pipes are sealed with the gasket, wherein the gasket is the gasket according to any one of claims 1 to 8, wherein the inorganic material of the gasket is used. And polymerization of the metal mesh The range was stopped at the portion beyond the shoulder of the outer tube beyond the tip of the slit, the formation range of the inorganic material was minimized, and the highly rigid metal mesh material was configured as a base material.
[0022]
Thus, the gasket In Inorganic material And metal mesh polymerization The exposed area of the outer tube is stopped at the portion beyond the shoulder of the outer tube from the tip of the slit, the formation range of the inorganic material is minimized, and the high-rigidity metal mesh material is configured as a base material. It is possible to prevent the exhaust gas from leaking from the clearance between the inner pipe and the slit formed in the enlarged diameter part, and it is flexible and flexible even if the inner and outer pipes are twisted or excessive bending torque is generated. It is possible to minimize the range of the inorganic material having a high density and limit the density increase, suppress plastic deformation due to tightening of the tightening band, and exhibit a sufficient sealing function for a long period of time.
[0023]
Preferably, since at least the end surface of the band-like inorganic material is cut and inclined as in the invention described in claim 10, the phase of the end surface of the inorganic material is in phase with the slit portion formed in the enlarged diameter portion of the outer tube. Even if they match, it does not engage over the entire length of the end surface, so stable sealing performance can be maintained, and there is no need to perform special phasing when the gasket is assembled, resulting in excellent mass productivity. Yes.
[0024]
Moreover, if the taper part which carries out a line contact with the shoulder inner peripheral surface of the said outer tube is formed in the outer periphery of the edge part of the said gasket like invention of Claim 11, the taper shape of a shoulder part inner peripheral surface is carried out. The end portions can be brought into close contact with each other, and the sealing performance is further improved. In addition, misassembly of the gasket is prevented, and the ease of assembly when the gasket is assembled into the outer tube is improved.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a first embodiment of an exhaust pipe gasket according to the present invention.
[0026]
The gasket 1 includes an inorganic material 2 made of expanded graphite or the like, and a metal mesh 3 knitted from a wire material such as SUS304. The metal mesh 3 is polymerized 2 to 3 times so that the gasket 1 has a desired thickness, and then the inorganic material 2 and the metal mesh 3 are spirally wound so that the inorganic material 2 becomes the outermost peripheral surface. It is formed in a cylindrical shape. Here, the inorganic material 2 is stopped on the outer peripheral surface of one end, that is, the formation range of the inorganic material 2 is stopped at the substantially central portion from the one end surface of the gasket 1 to minimize the formation range of the inorganic material 2, and the highly rigid metal mesh 3 Is configured on the mother's body. Moreover, the end surfaces 2a and 3a of the inorganic material 2 and the metal mesh 3 are cut by being inclined. Further, a tapered chamfer 4 is formed on the outer periphery of the gasket 1 on the inorganic material 2 side. Expanded graphite used as the inorganic material 2 has the same heat resistance, chemical resistance, and low friction coefficient as ordinary graphite, and can be easily obtained by pressing with a press or the like without using a binder. It is suitable for this kind of seal member because it can be formed into a shape of
[0027]
By knit knitting a stainless steel wire material with high mechanical strength on the metal mesh 3, not only is the direction of the gasket 1 difficult to be given, but also the durability and rigidity are improved by the entanglement of the wire material. Further, by forming the base material of the gasket 1 with this metal mesh 3, even if the inner and outer pipes to be described later are twisted or excessive bending torque is generated, the plastic deformation of the gasket 1 is suppressed, and a sufficient sealing function is provided over a long period of time. It can be demonstrated.
[0028]
In the present embodiment, the inorganic material 2 is formed on the outer peripheral surface of the metal mesh 3 that is polymerized and wound in a spiral shape. However, depending on the use conditions, the metal mesh 3 and the inorganic material 2 may be combined. A plurality of polymerized sheets may be wound in a spiral shape. Alternatively, the metal mesh 3 may be formed by knitting a stainless wire, impregnated with the powder of the inorganic material 2, and then wound in a spiral shape to form a desired cylindrical shape. Further, the inorganic material 2 and the metal mesh 3 may be integrally formed. Further, in this embodiment, expanded graphite is used for the inorganic material 2, but other than this, mica sheet, ceramic fiber, molybdenum disulfide and the like can be exemplified.
[0029]
FIG. 2 is a partial cross-sectional view of an exhaust pipe joint in which the exhaust pipe gasket 1 according to the present invention is attached to an exhaust pipe used in a vehicle such as an ATV, a snow vehicle, or a motorcycle. The exhaust pipe joint is a plug-in type, and includes an inner pipe 5, an outer pipe 6, and a fastening band 8 that is attached to the outer peripheral surface of the outer pipe 6 and fastens the outer pipe 6 with a bolt 7. As shown in FIG. 3, the outer tube 6 has a main body portion 6a having an inner diameter formed slightly larger than the outer diameter of the inner tube 5, and a large shoulder portion 6b from the main body portion 6a. It consists of the enlarged diameter part 6c formed in the diameter. Moreover, the flange part 6d extended in radial direction outward is formed in the end surface of the enlarged diameter part 6c.
[0030]
A plurality of slits 7 having a predetermined length are formed in the enlarged diameter portion 6c of the outer tube 6 so as to open at the end face and to extend in the axial direction with a uniform circumference. The slit 7 is used to easily reduce the diameter of the enlarged diameter portion 6c when tightened with the tightening band 8. Further, the flange portion 6d formed on the end surface functions for positioning the fastening band 8.
[0031]
In FIG. 2, the distal end portion 5 a of the inner tube 5 is inserted to a position passing through the enlarged diameter portion 6 c of the outer tube 6 and beyond the shoulder portion 6 b. For this reason, since the exhaust gas flowing in the exhaust pipe leaks to the outside from the tip of the slit 7, in this embodiment, the exposed range of the inorganic material 2 in the gasket 1 is changed from the shoulder 6 b of the outer pipe 6. It stops at the part beyond the tip of the slit 7. Therefore, the range of the inorganic material 2 that is flexible, highly flexible, and has a limit to high density is minimized, the same sealing performance as the conventional one is maintained, and the inner and outer pipes 5 and 6 are twisted or excessively bent torque. Even if this occurs, the plastic deformation of the gasket 1 can be suppressed and a sufficient sealing function can be exhibited over a long period of time.
[0032]
Here, as shown in FIG. 1, at least the end surface 2 a of the strip-shaped inorganic material 2 is cut while being inclined, so that the end surface 2 a of the inorganic material 2 is phased with the slit 7 formed in the enlarged diameter portion 6 c of the outer tube 6. Even if they match, the end face 2a is not engaged over the entire length, so that a stable sealing performance can be maintained, and it is not necessary to perform special phase matching when the gasket 1 is assembled. Is excellent. Further, the chamfer 4 formed at one end of the gasket 1 is in line contact with the inner periphery of the shoulder 6b of the outer tube 6 to further improve the sealing performance of the gasket 1 (see FIG. 2).
[0033]
FIG. 4 shows the fastening band 8. The fastening band 8 is formed by winding a steel strip such as stainless steel, and is formed in a ring shape having a diameter slightly larger than the outer diameter of the enlarged diameter portion 6 c of the outer tube 6. The end face is integrally formed with an ear portion 8a protruding outward in the radial direction. Further, a bolt hole 8b for fitting a bolt (not shown) is formed in the ear portion 8a.
[0034]
Next, the manufacturing method of the gasket 1 is demonstrated using FIG. The material 1 ′ of the gasket 1 is formed in advance to be slightly larger in diameter than the product and is extrapolated to the tip of the punch 9. Thereafter, the inner peripheral surface of the material 1 ′ is constrained by the outer diameter of the punch 9 and the outer peripheral surface is constrained by the inner diameter of the upper mold 10. On the other hand, the width dimension of the material 1 ′ is formed in advance so as to be longer than the width dimension of the product, and is compressed and molded to a predetermined width dimension at the end surfaces of the lower mold 11 and the stripper 12. After molding, the stripper 12 is lowered with a pin (not shown) and the product is discharged.
[0035]
FIG. 6 is a perspective view showing a second embodiment of the exhaust pipe gasket according to the present invention. In addition, the same code | symbol is attached | subjected to the same site | part and the same component as embodiment mentioned above, and the detailed description is abbreviate | omitted. The difference from the embodiment described above is that the inorganic material 14 is exposed to the inner peripheral surface with substantially the same width as the inorganic material 2 formed on the outer peripheral surface, and the inorganic material 15 is formed on the end surface including the chamfer. It is the point which formed by exposing.
[0036]
As in this embodiment, since the inorganic materials 14, 2, 15 such as expanded graphite suitable for sealing are exposed on the inner peripheral surface and the end surface of the insertion side end portion of the gasket 13, the inner and outer tubes 5, 6 The sealability of the joint, especially the tip of the slit 7, can be further improved, the formation range of the inorganic material is minimized, and the base is composed of the metal mesh 3 made of a highly rigid stainless steel wire or the like. Even if the pipes 5 and 6 are twisted or an excessive bending torque is generated, the plastic deformation of the gasket 13 can be suppressed and a sufficient sealing function can be exhibited over a long period of time.
[0037]
FIG. 7 is a partially cutaway perspective view showing a third embodiment of the exhaust pipe gasket according to the present invention, and FIG. 8 is a longitudinal sectional view. The difference from the second embodiment described above is that a thermally expandable inorganic material is interposed inside the wound metal mesh. Description is omitted.
[0038]
In this embodiment, inorganic materials 14, 2, 15 such as expanded graphite suitable for sealing are exposed and formed on the inner and outer peripheral surfaces and end surfaces of the insertion side end of the gasket 16. Further, a thermally expansible inorganic material 17 is interposed between the inorganic materials 14 and 2 formed at least on the inner and outer circumferences between the layers of the wound metal mesh 3 serving as a base. This heat-expandable inorganic material 17 is obtained by adding heat-resistant fibers to unexpanded graphite before heat treatment that expands by heating and molding it into a sheet shape with a heat-resistant binder.
[0039]
Examples of heat resistant fibers include inorganic fibers and aramid fibers. As the inorganic fibers, for example, artificial fibers such as glass fibers, rock wool, and ceramic fibers are suitable, but natural mineral fibers can also be used. Further, as the unexpanded graphite, it is possible to use a naturally obtained crystalline scaly graphite that has been subjected to an acid treatment to give thermal expansion performance. Furthermore, NBR, SBR, acrylic rubber, silicon rubber, or the like can be used as the heat-resistant binder. This heat-expandable inorganic material 17 is generally used as a filler for a fire door and a fire spreader for a ventilation unit such as an attic. When the surroundings become hot, it is in a range of 30 to 50 times. It has the feature of volume expansion. Here, even if the unexpanded graphite rapidly expands and scatters due to an increase in the ambient temperature, the unexpanded graphite can be expanded while suppressing its expansion with a heat-resistant fiber such as an aramid fiber that is entangled with a binder such as rubber.
[0040]
By interposing between the layers of the metal mesh 3 around which the thermally expandable inorganic material 17 is wound, the gasket 16 is heated by exhaust gas or the like passing through the exhaust pipe without firmly tightening the gasket 16 with the fastening band 8. However, since the thermally expandable inorganic material 17 itself expands and does not return to its original state, the degree of adhesion between the gasket 16 and the inner and outer tubes 5 and 6 is remarkably increased. Therefore, not only the assemblability is improved, but also the sealing performance of the joint portion of the inner and outer tubes 5 and 6, particularly the tip portion of the slit 7, can be further improved as compared with the embodiment described above.
[0041]
In the durability test conducted by the applicant, the thermally expandable inorganic material 17 was wound instead of the inorganic material 2 made of expanded graphite or the like of the first and second embodiments (FIGS. 1 and 6) described above. It was verified that even when the metal mesh 3 was exposed on the inner and outer peripheral surfaces, the same sealing function was exhibited. This is presumably because the unexpanded graphite as the main component expands due to a temperature rise and adheres firmly to the joint between the exhaust pipe joint and the inner and outer pipes 5 and 6.
[0042]
FIG. 9 is a perspective view showing a fourth embodiment of the exhaust pipe gasket according to the present invention. The same parts and the same parts as those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
[0043]
This embodiment is a gasket for cost reduction, which is suitable for sealing the gasket 13 of the second embodiment shown in FIG. 6 described above and the inner and outer peripheral surfaces and end surfaces of the end portion on the insertion side of the gasket 13. Inorganic materials 20, 19, and 21 mainly composed of zirconia or the like are coated. The inorganic materials 20, 19, and 21 have a heat resistance of 1000 ° C. or higher, polymerization is accelerated by moisture in the air during natural drying, and a strong coating film can be formed. The gasket 18 can be manufactured by a simple process in which a gasket formed by exposing an inorganic material such as expanded graphite is formed into a desired shape and size, the formed portion is immersed in a solution, and then dried. Therefore, the manufacturing cost can be reduced.
[0044]
Further, since the surface of the inorganic materials 20, 19, and 21 is more elastic than the inorganic materials 14, 2, and 15 of the above-described embodiment, the sealing function is improved and the inner and outer tubes 5, 6 are twisted. Even if an excessive bending torque is generated, the plastic deformation of the gasket 18 can be further suppressed, and a sufficient sealing function can be exhibited over a long period of time. Furthermore, since the inclined end surfaces 20a and 19a are covered with the coating layer of the inorganic materials 20 and 19, the sealing performance can be improved. The coating method is not limited to immersion, and may be a spray method that can easily form a coating film on a desired site.
[0045]
The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.
[0046]
【The invention's effect】
As described in detail above, the exhaust pipe gasket according to the present invention is interposed in the annular space formed by inserting the end portions of the inner and outer pipes, and the tightening band attached to the outer peripheral surface of the outer pipe. In a cylindrical exhaust pipe gasket that tightens the outer pipe and seals the joint portion, a band-shaped inorganic material and a metal mesh material are polymerized, and the metal mesh is exposed on the inner peripheral surface of the gasket, and The inorganic material is wound so that the inorganic material is exposed on the outer peripheral surface. And polymerization of the metal mesh Stop the range from one end surface at the approximate center, Tighten the part composed only of the metal mesh with the fastening band, By minimizing the formation range of the inorganic material and configuring the highly rigid metal mesh material as the base material, it is possible to prevent the exhaust gas from leaking from the gap formed between the outer tube and the inner tube. Even if the inner and outer pipes are twisted or excessive bending torque is generated, the range of inorganic material that is flexible and highly flexible and has a limit to high density is minimized, and plastic deformation due to tightening of the tightening band is suppressed. A sufficient sealing function can be exhibited over a long period of time.
[0047]
In addition, the main component of unexpanded graphite remains at the temperature even if it is exposed to the inner and outer peripheral surfaces of a metal mesh wound with a thermally expandable inorganic material such as unexpanded graphite instead of an inorganic material composed of expanded graphite. It expands by rising and firmly adheres to the joint portion of the exhaust pipe joint with the inner and outer pipes, so that a good sealing function can be exhibited.
[0049]
Further, the exhaust pipe joint according to the present invention has an enlarged diameter portion at an end portion thereof through a tapered shoulder portion, a flange portion extending radially outward at an opening portion of the enlarged diameter portion, and the enlarged diameter portion An outer tube formed with slits extending in the axial direction of the circumferentially equidistant portion, and an outer diameter slightly smaller than the inner diameter of the outer tube, penetrating the enlarged diameter portion of the outer fitting, and the shoulder portion A cylindrical gasket is interposed in the annular space formed by the inner fitting inserted beyond the end, and a tightening band is extrapolated to the enlarged diameter portion of the outer tube, and the tightening band is reduced in diameter by a bolt. In the exhaust pipe joint in which the inner and outer pipes are sealed with the gasket, the gasket is the gasket described above, and the inorganic material of the gasket And polymerization of the metal mesh The range is stopped at the portion beyond the shoulder of the outer tube beyond the tip of the slit, the formation range of the inorganic material is minimized, and the metal mesh material having high rigidity is configured as the base material. It is possible to prevent the exhaust gas from leaking through the gap between the pipe, especially the slit formed in the enlarged diameter part, and it is flexible and flexible even if the inner and outer pipes are twisted or excessive bending torque is generated. Therefore, the range of the inorganic material having a high density and a limit to the high density can be minimized, the plastic deformation due to the fastening by the fastening band can be suppressed, and a sufficient sealing function can be exhibited for a long period of time.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of an exhaust pipe gasket according to the present invention.
FIG. 2 is a partial cross-sectional view of an exhaust pipe joint in which a gasket according to the present invention is mounted on an exhaust pipe.
FIG. 3 is a perspective view showing an outer pipe of an exhaust pipe gasket according to the present invention.
FIG. 4 is a perspective view showing a fastening band of an exhaust pipe gasket according to the present invention.
FIG. 5 is an explanatory view showing a method of manufacturing an exhaust pipe gasket according to the present invention.
FIG. 6 is a perspective view showing a second embodiment of the exhaust pipe gasket according to the present invention.
FIG. 7 is a partially cutaway perspective view showing a third embodiment of an exhaust pipe gasket according to the present invention.
FIG. 8 is a longitudinal sectional view of the same as above.
FIG. 9 is a perspective view showing a fourth embodiment of an exhaust pipe gasket according to the present invention.
FIG. 10 is a partial cross-sectional view of a conventional exhaust pipe joint.
FIG. 11 is a perspective view showing an outer pipe of a conventional exhaust pipe joint.
FIG. 12 is a perspective view showing a conventional exhaust pipe gasket.
[Explanation of symbols]
1, 13, 16, 18 ... ・ ・ ・ ・ ・ Gasket
1 '・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Material
2, 14, 15, 19, 20, 21, inorganic material
2a, 3a, 19a, 20a, ... end face
3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Metal mesh
4 .... Chamfering
5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner pipe
5a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ the tip
・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer pipe
6a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Main body
6b ... shoulder
6c ..... Diameter expansion part
6d ... Flange
7 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Slit
8: Tightening band
8a ...... Ear part
8b ... Bolt hole
9 ... Punch
10 ... upper mold
11 ... lower mold
12 ... Stripper
17 ..... Thermally expandable inorganic material
50 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Gasket
51 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner pipe
52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer tube
53 ..... Diameter expansion part
54 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Main body
55 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Tightening band
56 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder
57 ... Opening
58 ... Flange
59 ... slit
60 ..... one end face
61 ... flange
62 .......... other end face
63 ... outer peripheral surface
64 ..... Inner peripheral surface
65 ... Ear
66 ... Bolt hole
67 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Bolt

Claims (11)

Cylindrical shape that is inserted in an annular space formed by inserting the end portions of the inner and outer tubes, tightens the outer tube via a fastening band attached to the outer peripheral surface of the outer tube, and seals the joint portion In the exhaust pipe gasket,
A strip of inorganic material and the metal mesh member is polymerized, the metal with, this inorganic material wherein the metal mesh is exposed on the inner peripheral surface of the gasket, and the inorganic material to the outer peripheral surface is wound so as to expose The mesh polymerization range is stopped at the substantially central portion from one end surface, the portion composed only of the metal mesh is tightened with the tightening band, the formation range of the inorganic material is minimized, and the highly rigid metal mesh material is removed. An exhaust pipe gasket characterized in that it is configured as a matrix.   The exhaust pipe gasket according to claim 1, wherein the metal mesh material is wound into a spiral shape and press-formed to a desired size.   The exhaust pipe gasket according to claim 1 or 2, wherein the inorganic material is exposed from an end face of the gasket to an inner peripheral face thereof with substantially the same width as the outer peripheral face.   The exhaust pipe gasket according to any one of claims 1 to 3, wherein the inorganic material is expanded graphite, and the metal mesh material is knitted from a stainless wire.   The exhaust pipe gasket according to any one of claims 1 to 4, wherein the surface of the inorganic material is coated with a liquid inorganic material mainly composed of zirconia to form a thin film layer.   The exhaust pipe for an exhaust pipe according to any one of claims 1 to 5, wherein a thermally expandable inorganic material is interposed between at least one end face of the outer periphery to a substantially central portion between the wound layers of the metal mesh. gasket. Cylindrical shape that is inserted in an annular space formed by inserting the end portions of the inner and outer tubes, tightens the outer tube via a fastening band attached to the outer peripheral surface of the outer tube, and seals the joint portion In the exhaust pipe gasket,
A belt-like thermally expandable inorganic material and a metal mesh material are polymerized, and wound so that the metal mesh is exposed on the inner peripheral surface of the gasket and the thermally expandable inorganic material is exposed on the outer peripheral surface, The polymerization range of the thermally expandable inorganic material and the metal mesh is stopped at the substantially central portion from one end face , and the portion composed only of the metal mesh is tightened with the tightening band, thereby forming the formation range of the thermally expandable inorganic material. An exhaust pipe gasket characterized in that the metal mesh material having a minimum rigidity and high rigidity is formed as a base.   The exhaust pipe gasket according to claim 6 or 7, wherein the thermally expandable inorganic material comprises unexpanded graphite, a heat resistant fiber, and a heat resistant binder. There is an enlarged diameter portion at the end through a tapered shoulder, a flange portion extending radially outward at the opening of the enlarged diameter portion, and an axially extending circumferential direction at the enlarged diameter portion An outer tube formed with a slit, and an inner tube having an outer diameter slightly smaller than the inner diameter of the outer tube, penetrating the enlarged diameter portion of the outer fitting, and inserted beyond the shoulder portion. A cylindrical gasket is interposed in the annular space, and a tightening band is extrapolated to the enlarged diameter portion of the outer tube, and the tightening band is reduced in diameter by a bolt and the inner and outer tubes are sealed with the gasket. In the exhaust pipe joint
The gasket is the gasket according to any one of claims 1 to 8, and the polymerization range of the inorganic material of the gasket and the metal mesh is stopped at a portion from the shoulder of the outer tube to the end of the slit, An exhaust pipe joint characterized in that the formation range of the inorganic material is minimized and the metal mesh material having high rigidity is configured as a base.   The exhaust pipe joint according to claim 9, wherein at least an end face of the band-shaped inorganic material is cut while being inclined.   The exhaust pipe joint according to claim 9 or 10, wherein a tapered portion that is in line contact with an inner peripheral surface of a shoulder portion of the outer tube is formed on an outer periphery of an end portion of the gasket.

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