JP5911163B1 - Metal gasket for exhaust pipe - Google Patents

Abstract

The present invention relates to a gasket used for a connecting portion of an exhaust path of an automobile, which can be used repeatedly, is resistant to heat and has a high durability, and in particular, dynamic movement such as shaking and bending of an exhaust pipe or the like. We provide metal gaskets for exhaust pipes with flexible characteristics that can be flexibly adapted. Two elastic metal plates are combined so that a ring-shaped half-beat type one-sided stepped contact stepped portion 5 that is offset in a different thickness direction from an edge portion of a vent opening hole 3 is widened. At least two or more sets are stacked and laminated, and spot welding is performed by spot welding at least two or more locations on the pitch circle that is the same distance from the center of the ventilation opening hole 3 and in the vicinity of the mounting hole 7. A configuration was adopted in which the entire laminated elastic metal plate 2 was bent by pressing during spot welding. [Selection] Figure 1

Description

  The present invention relates to a gasket technology used for an exhaust pipe of an automobile, and more specifically, can be repeatedly used for a connection portion between the exhaust pipe and each exhaust system component, and the exhaust pipe or the like is shaken, vibrated, or bent. The present invention relates to a technology of a metal gasket for an exhaust pipe having a flexible characteristic of flexibly following a dynamic movement.

  In an internal combustion engine, exhaust gas discharged from the exhaust side of a cylinder head is discharged to the outside (in the atmosphere) through an exhaust manifold, a catalyst, and a silencer. In such an exhaust system, these exhaust system components are connected by an exhaust pipe, and a gasket for preventing exhaust gas from leaking is used at the joint.

  Exhaust gas leaks not only cause severe noise, but depending on the location of the exhaust leak, unburned gas may be released to the atmosphere, which has a problem of adversely affecting the environment. Therefore, the gasket is required to be resistant to heat and corrosion and to be sealed to follow the opening of the connecting portion due to impact or vibration.

  Conventionally, asbestos has long been used as a material suitable for these requirements. This is because, according to asbestos, it has a property that it has sufficient heat resistance and also has a high follow-up property against deformation. However, asbestos was found to cause health damage, and its use was completely banned after 2012, and an alternative with the same or better characteristics than asbestos was required.

  Various techniques have been proposed triggered by the prohibition of the use of asbestos. For example, non-asbestos high-performance graphite packing (expanded graphite packing), a thin steel plate made of stainless steel with excellent heat resistance, and a laminated structure that follows the deformation and behavior of the mating flange. The gasket technology such as a metal jacket type that has an excellent sealing property, and further covers an elastic member with a thin metal.

  However, most of these depend on the elastic force depending on the thickness, or the seal is secured by crushing the deformed part. This is a consumable part that cannot be used. If it is reused as it is, there is a problem that exhaust leakage occurs. Further, if the contact stepped portions are tightened in a state where the positions of the contact stepped portions are shifted, there is a possibility of causing a deformation that hinders the elasticity of the contact stepped portion. For this reason, it can be said that there is a demand for a structure that does not cause misalignment so as not to reduce the effect of the contact step portion.

  Especially in gym cars, rallies, and racing vehicles that run on circuits, maintenance of engines and transmissions is frequently performed, so it is often necessary to remove the connecting part of the exhaust pipe in response to this, It is economically inefficient to replace a gasket that is not exhausted in terms of material each time. Therefore, there is a need for a gasket that can be used repeatedly.

  In view of the above problems, various techniques have been proposed. For example, "a metal laminated gasket structure that can be temporarily fixed by a simple temporary fixing operation, and that can be easily formed without a change in the gasket structure for temporary fixing and without cost increase" (Patent Document) 1) has been proposed and is a known technique. More specifically, it is a structure of a metal laminate type gasket in which a plurality of elastic metal plates are laminated and have mounting holes on the outer peripheral portion, and only a part of the outer peripheral portion of the laminated elastic metal plates is pressure welded by spot welding. By fixing, the elastic metal plates on the outer peripheral portion on the side opposite to the fixed portion are configured to peel off in a direction substantially perpendicular to the surface of the laminated contact stepped portion, thereby preventing the flange from coming off from the gap. is there. There is no description in the literature concerning the purpose of maintaining elasticity as a gasket, there is no description or suggestion about bending the whole by two or more spots, and when repeatedly attaching and detaching The problem has not yet been solved.

  Also, a metal gasket structure (see Patent Document 2) suitable for use in a synthetic resin flange has been proposed and is a known technique. More specifically, the metal gasket disposed between the resin flange and the aluminum flange is arranged so that the two elastic metal plates each provided with the contact stepped portion face the opposite direction of the half contact stepped portion. It is configured by stacking and bonding. This technology is related to a gasket made of a plurality of elastic metal plates having a contact stepped portion, but in order to improve adhesion, rubber or the like is attached to the surface of the elastic metal plate, and an exhaust pipe is connected. This is not a technique for a portion to which high temperature and vibration are applied, and has not yet solved the above problem.

  Therefore, in order to solve these problems, the inventor of the present application pays attention to the fixing method and the fixing position in a gasket having a configuration in which a plurality of plates having contact step portions are stacked, and intentionally bends in the stacked state. The idea is to provide a “metal gasket for exhaust pipe” according to the present invention.

JP 2009-144773 A JP 2000-240797 JP 2004-232471 A

  INDUSTRIAL APPLICABILITY The present invention can be used repeatedly in a gasket used for a connection part of an automobile exhaust path and is resistant to heat and has a high durability. In particular, the present invention is flexible for dynamic movement such as shaking and bending of an exhaust pipe. It is an object to provide a metal gasket for an exhaust pipe having flexible characteristics that can be accommodated.

Method of manufacturing a main barrel gasket corresponding to the inner diameter of the exhaust pipe in accordance with the present invention, provided in the elastic metal plate, a ventilation opening holes, at least two or more mounting holes in the vicinity of the vent opening hole The half-beat type one-sided stepped shape that offsets the ring-shaped contact surface in the thickness direction by providing a contact stepped portion at the edge of the vent hole.
Before Symbol combining the elastic metal plate two to spread apart so that the opening edge by different offset directions, which are laminated by overlapping at least two or more pairs, a plurality of elastic metal plate wherein are laminated, wherein performing spot welding in at least two places near the center from the hole for the mounting even on a pitch circle which is a same distance ventilation opening hole by spot welding machine, which is the laminated by pressing at the time of welding point according A means for bending and fixing the entire elastic metal plate was adopted.

Further, the present invention, the mounting hole be three or more provided the method for producing a metal gasket for an exhaust pipe, the welded portion points by spot welding machine, on the pitch circle of the same distance from the center of the opening hole And the same number as the mounting holes,
It is also possible to employ facilities to means in the vicinity of the hole for with said mounting.

A means using a stainless steel material can be adopted for the plurality of laminated elastic metal plates.

May be the stainless steel material is adopted a means for Ru using SUS304 or SUS316.

  According to the exhaust pipe metal gasket according to the present invention, since the whole is bent and spot-welded, dynamic movements such as bending and shaking occur in the connection state between the exhaust system components and the exhaust pipe. However, an advantageous effect is exhibited over the prior art that exhaust leakage can be reduced because the pressing is performed following the clearance between the contacting flange surfaces.

  Further, according to the metal gasket for an exhaust pipe according to the present invention, the contact stepped portion returns to the original shape within the elastic limit, so that the advantageous effect that it can be repeatedly used is exhibited in addition to the above effect. is there.

  Moreover, according to the metal gasket for exhaust pipes which concerns on this invention, since the laminated | stacked elastic metal plate is fixed by spot welding, the outstanding effect that the shift | offset | difference of each elastic metal plate does not arise is exhibited.

  Moreover, according to the metal gasket for exhaust pipes according to the present invention, an excellent effect that the cost can be reduced in the component configuration and the manufacturing process is exhibited as compared with the metal jacket type gasket.

It is a whole block explanatory view of the exhaust pipe metal gasket according to the present invention. It is attachment explanatory drawing of the contact level | step-difference part which concerns on this invention. It is sectional drawing explaining that when attaching the metal gasket for exhaust pipes which concerns on this invention, it attaches equally. It is a figure which shows the Example when there are three holes for attachment in the metal gasket for exhaust pipes which concerns on this invention. It is explanatory drawing explaining the bending of the Example explanatory photograph and contact surface which concern on this invention.

The exhaust pipe metal gasket according to the present invention is characterized by the fact that it is possible to eliminate the displacement when attaching a large strain in addition to preventing exhaust leakage of the elastic limit. Embodiments will be described below with reference to the drawings.
The overall shape and the shape of each part of the exhaust pipe metal gasket shown in the present embodiment are not limited to the embodiments described below, and are within the scope of the technical idea of the present invention, that is, the same operational effects. It can change within the range of the shape and dimension which can exhibit.
(Example 1)

The present invention will be described with reference to FIGS. FIG. 1 is a perspective view and a cross-sectional view showing an entire configuration of a metal gasket for an exhaust pipe according to the present invention, and FIG. 2 is a cross-sectional view for explaining a mounting shift when the metal gasket for an exhaust pipe according to the present invention is attached. . FIG. 3 is a cross-sectional view for explaining that the metal gasket 1 for exhaust pipe according to the present invention is attached evenly.
Fig.1 (a) shows the whole perspective view of this invention, FIG.1 (b) shows the same top view. FIG.1 (c) is a figure which shows the AA sectional view, and FIG.1 (d) is a figure which shows the BB sectional drawing. FIG. 1E is an enlarged view in which the contact step portion 5 is enlarged. FIG. 2A is a top view of the present invention. FIG. 2B is a schematic cross-sectional view taken along the section CC, and includes upper and lower flanges. FIG. 2C is also a view taken along the line CC, and is fastened by the flange. Indicates the state. FIG. 2D is a diagram showing a conventional example, in which an elastic metal plate is fixed only at one place. FIG.2 (e) is a figure which shows a prior art example, and is a figure which shows the state fastened by the upper and lower flanges. FIG. 3A is a top view of the present invention. FIG. 3B is a cross-sectional view taken along the line DD, and includes upper and lower flanges and fixing screws 11. FIG. 3 (c) is a top view of the present invention and shows the direction in which the gasket is in close contact with the flange. FIG. 4 is an explanatory view showing an embodiment in which there are three mounting holes in the exhaust pipe metal gasket according to the present invention.

  The exhaust pipe metal gasket 1 is composed of a plurality of elastic metal plates 2. Further, the exhaust pipe metal gasket 1 is mainly used for improving the sealing degree of the connecting portion when connecting the exhaust gas exhaust passage exhausted from the engine or the like and the exhaust pipe. The gap between the joints is eliminated by the elasticity and flexibility of the exhaust pipe metal gasket 1 sandwiched between the flanges 9 of the joints.

  The exhaust pipe metal gasket 1 according to the present application has a ventilation opening hole 3 and a mounting hole 7, and the whole is fixed by two spot welds 6. The alignment portion 8 is a notch for positioning when the whole is fixed. In a single component before being fixed to the flange, there is a gap CL between the elastic metal plates 2 at a position far from the spot weld 6. The elastic metal plate 2 is a metal and has a structure in which two elastic metal plates 2 are laminated. Although it is desirable to use a SUS300 or SUS400 stainless steel plate as the material, it has elastic properties like spring steel and returns to the shape of the contact step 5 when it is removed even if it is pinched by the flange 9. If it is, it will not specifically limit. The thickness of the elastic metal plate 2 is about 0.5 mm. The overall shape is a substantially rhombus shape in which a vent opening hole 3 for exhaust is provided at the center, the periphery thereof is enclosed in an annular shape, and attachment holes 7 for fixing to the flange 9 are opened at both ends. .

  The elastic metal plate 2 is formed by forming a contact step portion 5 having a half-bead type one-side step shape on the inner peripheral edge portion of the vent hole 3. The contact step portion 5 has a structure bent in a crank shape so as to be offset in the thickness direction (FIG. 1 (e)), and is laminated and bonded so that the offset directions are in opposite directions (FIG. 1). (C) and (d)). That is, the bias is always applied in the direction of filling the gap between the flange portions 9. Such a configuration is adopted in that, when compared with a flat product, the elastic metal plate 2 or the flange 9 and the two bent portions connected to the contact surface 4 forming the crank shape of one side step are opposed to each other. This is because the exhaust leakage prevention effect is exhibited by receiving a line contact with a high line pressure or a surface contact with a high surface pressure in a circumferential shape. Further, the elastic metal plate 2 can be reused by being within a range in which the shape can be restored within the elastic limit. Note that the half bead is not a full bead, but a linear pressure higher than that of a half bead can be obtained, but there is a problem in terms of wearability due to excessive linear pressure and a space to form a full bead at the edge of the opening hole. This is because it is difficult to achieve this, and it becomes difficult to form the overall wave-like deflection.

  As described above, the shape of the abutting step portion 5 is a shape that is arranged so that the offset shape faces in the opposite direction. By making the offset an obtuse angle, the cross-sectional shape lays the Y-shape. When the flange portion 9 is fastened, it is thicker than the other portions in the exhaust pipe metal gasket 1 because it is thicker than the other portions by the offset amount t of the half-beat type contact step portion 5 portion. As the number of sheets increases, the thickness of the exhaust pipe metal gasket 1 before mounting increases.

  When the metal gasket 1 for an exhaust pipe in such a laminated state is viewed in a cross-sectional view along the line AA, the elastic metal plates 2 are in contact with each other at the contact step portion 5 portion, and the gap CL is open at other positions. Further, as seen from the cross-sectional view taken along the line B-B, the entire portion is closely attached and fixed at the spot welded portion 6, but the other portion has a structure in which a gap CL is formed substantially in a bow shape. When the flange portion 9 is fastened, all surfaces are brought into close contact with each other, but the contact step portion 5 portion is stronger and urges the flange portion 9 so that the adhesion is further enhanced.

  The lamination is fixed by spot welding the spot welded portion 6 with a spot welder, and the fixing position is symmetrical from the center point of the vent hole 3. The spot weld 6 is disposed in the vicinity of the mounting hole 7 (FIG. 1A). For fixing, spot welding is preferable in terms of workability and durability. Other methods may be used as long as workability and durability are satisfied. However, if the thickness is affected, it may cause exhaust leakage, so it cannot be used if the thickness of the rivet or the like is changed.

  Next, along with FIG. 2, the detail of the operation | movement at the time of the fastening of the flange part 9 is demonstrated including the conventional operation | movement. FIG. 2B is a schematic diagram of a cross section taken along the line C-C, and includes the flange 9. Moreover, FIG.2 (d) is a figure in case a spot weld part is only one place on the right side on the paper surface as a prior art example. The CC line represents the entire cross section including the spot welded portion 6, and when the cross section is drawn with actual dimensions, the main part becomes smaller, and will be described with a schematic cross-sectional view. In FIG. 2B, the upper and lower flange portions 9 are contact surfaces that serve as a connection portion between exhaust system parts such as a catalyst and a silencer and the exhaust pipe.

  It is desirable that the front end portion of the contact step portion 5 is slightly outside the exhaust hole of the flange portion 9 in the fastened state. This is because if the tip of the contact step 5 protrudes inward from the exhaust hole of the flange 9, the exhaust flow is hindered. Further, when the tip of the half-bead type contact step 5 is larger than the exhaust hole of the flange 9 and is shifted to the outer peripheral side, the tip of the contact step 5 is recessed more than the exhaust hole of the flange 9, and the exhaust flow This is because it causes disturbance.

  Next, for comparison, a conventional example will be described with reference to FIG. The arrangement of the exhaust pipe metal gasket and the flange portion 9 is the same as in FIG. The difference is that there is no spot weld 6 at the left end of the page. Since there is no spot weld 6, the left end is completely free and there are no restrictions on the top, bottom, left and right. Since the restriction as a whole is only the spot welded portion 6 at the right end portion, the elastic metal plates 2 are arranged substantially parallel in the vicinity of the left end.

Next, the cross section at the time of fastening is demonstrated along FIG.2 (c) and FIG.2 (d). When the flange portion 9 is fastened, screws 11 are inserted into the mounting holes 7 and fixed at two locations. As a result, the durability is increased during repeated use with respect to one spot welding. Further, the thickness of the exhaust pipe metal gasket 1 is gradually reduced, and at the time of fastening, the contact stepped portion 5 and other portions have substantially the same thickness. The thickness is the same as in the present invention and the conventional one.
At the time of fastening, the abutting step portion 5 is offset, so it is deformed while sliding slightly. Since the fastening is performed by fastening the vicinity of the mounting hole 7, the fastening near the contact step portion 5 is relatively delayed.

Here, a conventional example will be described. As shown in FIG. 2 (d), the spot welded portion 6 is only on the right side. Therefore, when the vicinity of the mounting holes 7 at both ends is tightened, the right side is the elastic metal plate 2. There is no deviation from each other. On the other hand, since the elastic metal plates 2 are not fixed to each other on the left side, there is a difference in movement due to tightening. For this reason, the position of the end portion of the contact step portion 5 with respect to the exhaust hole of the flange portion 9 at the time of fastening may be different between the right side and the left side.
On the left side, there is a possibility that the elastic metal plates 2 may be shifted from side to side due to the sliding of the contact step portion 5. If it does so, the edge part of the contact | abutting level | step-difference part 5 may not align, but there exists a possibility that the effect of an original gasket cannot be exhibited (FIG.2 (e) arrow).

  On the other hand, in the present invention, since both the left and right ends are fixed, the same sliding and movement is performed on the left and right for tightening at the time of fastening, so that the flange portion 9 abuts against the exhaust hole at the time of fastening. The position of the end portion of the step portion 5 can be made equal to the left and right. Further, since the elastic metal plates 2 are fixed on both the left and right sides, the positions of the contact stepped portions 5 do not shift (arrows in FIG. 2 (c)).

Thus, the stability of the sealing effect of the metal gasket 1 can be enhanced by having a plurality of spot welds 6 for fixing the elastic metal plates 2 to each other.
In addition, by making the spot welded portion 6 near the mounting hole 7, the spot welded portion 6 is fixed at a position far from the contact stepped portion 5, and the elastic force of the contact stepped portion 5 can be reduced. .

  Next, the effect of the two spot welds 6 being displaced by a predetermined angle in the vicinity of the mounting hole 7 as seen from the center point of the vent hole 3 will be described with reference to FIG. FIG. 3A is a top view of the exhaust pipe metal gasket 1. FIG.3 (b) is a schematic diagram of a DD line cross section. FIG. 3C shows the effect of the present invention. In FIG. 3 (b), the upper and lower sides are the flange portion 9, the holes of the flange portion 9 are the gasket mounting screw holes 13, and the screws 11 and nuts 12 are fixed thereto. Since the exhaust pipe metal gasket 1 is fixed by the spot welded portion 6 and other portions are expanded by the offset structure of the contact stepped portion 5, a clearance CL is formed in the vertical direction. The spot welded portion 6 is located at a position shifted from the position of the mounting hole 7 by a predetermined angle when viewed from the center point of the ventilation opening hole 3. In the cross-sectional view, the spot weld 6 is slightly left of the mounting hole 7. Assuming that the position of the spot welded portion 6 is a point-symmetrical position with respect to the central axis of the vent hole 3, the positions of the spot welded portion 6 and the mounting hole 7 are the same for the left and right spot welded portions 6. .

  Considering the fastening operation of the flange portion 9, the screw 11 and the nut 12 are inserted into the gasket mounting screw hole 13 of the flange portion 9 and gradually tightened. At that time, the vicinity of the mounting hole 7 is first tightened. When the exhaust pipe metal gasket 1 is tightened in the vicinity of the mounting hole 7, the spot welding portion 6 is on the left side in the cross-sectional view, so that the tightening is naturally performed in the right direction. This is the same for both the mounting holes 7 in the cross-sectional view. At the time of tightening, the offset shape of the contact step portion 5 is also crushed and closes while sliding. When there is no spot weld 6, the crushing direction of the contact step 5 is indefinite, but in the present invention, the crushing direction is always crushed counterclockwise in FIG. Therefore, the fastening of the flange portion 9 can be completed in a state where the relationship between the contact step portion 5 and the hole of the flange 9 is equal to the left and right. Since the predetermined angle needs to be in the vicinity of the mounting hole 7, about 10 degrees is appropriate.

  In this way, by making the spot welded portion 6 in the vicinity of the mounting hole 7 and in a line-symmetrical position from the central axis of the ventilation opening hole 3, the contact stepped portion 5 can slide evenly during tightening. Thus, the positional accuracy of the contact step portion 5 and the flange portion 9 can be increased.

  As another example, when there are three mounting holes 7, the spot welds 6 may be arranged as shown in FIG. 4. More specifically, the relationship between the mounting hole 7 and the spot welded portion 6 is the same when viewed from the center of the ventilation opening hole 3. By setting it as such an arrangement | positioning, the shift | offset | difference of the contact | abutting level | step-difference part 5 at the time of fastening of the flange part 9 can be prevented.

FIG. 5 shows that the laminated elastic metal plates 2 cause intentional bending in the laminated state by pressing during spot welding, and the bending causes the gap CL between the elastic metal plates 2 to open. FIG. 5 (a) and FIG. 5 (b) show a state where a wave-shaped bending WA is generated by wobbling the contact surface 4 of the contact step portion 5 by acting and deforming. In the drawing, the reference number is shown: PKJ15-0009 Patent application 2015-096126 (Proof) Date of submission: May 10, 2015 7
A photograph is used for clarifying the degree of bending. FIG. 5 (a) is taken from an oblique direction, and FIG. 5 (b) is taken from a lateral thickness. FIG. 5 (c) schematically shows FIG. 5 (b). Application onset Ming By adopting the configuration represents a possible to generate and overall deflection WA as shown in FIG. 5 (a) and 5 (b), the clearance CL between the elastic metal plate 2 This is the basis for exhibiting the effect of preventing exhaust leakage by following vibrations and shocks.

  Conventionally, exhaust pipes of automobiles have been made of steel as well as asbestos, but connection parts such as silencers and catalysts that make up the exhaust system are easily corroded. There are many cases in which it will fall off completely from the flange part, etc., which will be the joint. This is because it is always in an environment affected by moisture and heating, and in such an adverse environment, it is often solved by changing from steel to stainless steel. Therefore, the third and subsequent claims specify the use of a stainless steel member as the material.

  However, even if it is simply stainless steel, there are stainless steel materials having a wide variety of characteristics, and it is necessary to prevent corrosion resistance, heat resistance, strength reduction due to welding, and the like. In addition, there are a number of different purposes for material selection. Regarding the types of stainless steel that should be used, the thickness, offset amount, bending angle, elastic limit, yield point, tensile strength, Determine by experiment from the elements. In the present invention, one example is shown below as a result of good experiment.

  As a specific example shown in the photograph used in FIG. 5, the material is SUS304, the material thickness is 0.2 mm, the vent hole 3 is 75 mm in diameter, and the mounting hole 7 is the target position. The two elastic metal plates of two locations are combined, and the two are combined to form a total of four layers, and the spot welded portion 6 has two locations in the vicinity of the mounting hole 7. . In general, stainless steel welding is usually performed by Tig welding performed in an atmosphere of an inert gas such as argon, and it is essential that a skilled engineer is required. Since an object is about 0.2 mm, the difficulty of welding is high on the contrary, and it is effective to use spot welding. As shown in FIGS. 5 (b) and 5 (c), in the four-plate configuration, the two inner contact surfaces 4 are substantially flat, and there is a gap between the two outer sheets. It can be seen that CL is formed.

  Further, in terms of the characteristics as a spring steel, it becomes SUS301 or SUS304, and in terms of durability, SUS304 is more effective in terms of higher corrosion resistance. In addition, SUS316, which is excellent in durability, heat resistance, and the like with respect to deterioration in a portion accompanied by deformation such as bending or drawing, belongs to the same austenite system and has excellent cost performance.

  Therefore, even if the exhaust system is shaken by vibration or shock, even if a large deflection occurs in the connection part of each part, what stainless steel material should be selected for the gasket that has the followability that can suppress exhaust gas leakage In other words, considering the proportional constant (stress / strain) between the stress and strain in elastic deformation and Young's modulus, within the elastic limit defined as the limit value of the elastic limit where the strain is removed when the stress is removed Choose one.

Even when bending stress is applied to the bent portion of the abutting step portion 5, it is necessary to select a material that does not undergo a deformation up to a plastic deformation region where permanent distortion remains and does not greatly deteriorate material properties.
In addition, if it is made of SUS400, it is possible to improve mechanical properties such as strength, corrosion resistance, and corrosion resistance by heat treatment, etc., and comprehensively consider from the cost and workability as described above. Then, I think that it is desirable to select a material that can be easily processed such as SUS304 to SUS316.

Some stainless steel materials, such as the 600 series, have extremely high strength and are not affected by heat. However, this is extremely expensive and has problems of workability and difficulty in installation. Therefore, it is necessary to select new materials that contribute to cost reduction. In the elastic metal plate according to the present invention, even if the contact step portion 5 is deformed by the external pressure, the elastic limit has a characteristic of returning to the original state when the external pressure is removed, that is, a region not accompanied by plastic deformation. Inside, the protruding contact | abutting level | step-difference part 5 returns to the original state, and the stainless steel material provided with the characteristic that it can be used repeatedly is required.

The exhaust pipe metal gasket 1 according to the present invention and a device for releasing the exhaust gas discharged from the internal combustion engine into the atmosphere are indispensable until the automobile is completely EVed. The exhaust system device requires a gasket. Therefore, the industrial applicability of the present invention is considered to be high. It is understood that the industrial applicability for improving the mounting quality of the gasket having the contact step portion is great.

DESCRIPTION OF SYMBOLS 1 Metal gasket for exhaust pipes 2 Elastic metal plate 3 Opening hole for ventilation 4 Ring-shaped contact surface 5 Contacting step part 6 Spot welding part 7 Mounting hole 8 Positioning part 9 Flange part 11 Screw 13 Mounting screw hole 12 Nut CL Gap WA swell

Claims (4)

A method of manufacturing a main barrel gasket corresponding to the inner diameter of the exhaust pipe,
The elastic metal plate is provided with an opening hole for ventilation and at least two mounting holes in the vicinity of the opening hole for ventilation,
A half-beat type one-side step shape that offsets the ring-shaped contact surface in the thickness direction by providing a contact step portion at the edge of the ventilation opening hole,
Before Symbol combining the elastic metal plate two to spread apart so that the opening edge by different offset directions, and laminated thereto a superposition of at least two or more sets,
Wherein a plurality of stacked elastic metal plate, subjected to a spot welding by spot welding machine at least two locations in the vicinity of the center from the hole for the mounting even on a pitch circle which is a same distance ventilation opening hole,
A method for manufacturing a metal gasket for an exhaust pipe, characterized in that the whole of the laminated elastic metal plates is bent and fixed by pressing during such spot welding. A method for producing the exhaust pipe metal gasket having three or more mounting holes,
The welding spot points by spot welding machine, on pitch circle as the same distance from the center of the opening hole, a same number of said mounting hole,
2. The method for manufacturing an exhaust pipe metal gasket according to claim 1, wherein the metal gasket is provided in the vicinity of the mounting hole. Wherein the plurality of elastic metal plate to be laminated, the manufacturing method for a metal gasket for an exhaust pipe according to claim 1 or claim 2, characterized in that made using stainless steel material. Method for producing a metal gasket for an exhaust pipe according to claim 3, wherein the stainless steel material is characterized Rukoto made with SUS304 or SUS316.