JP2562754B2 - Heat-resistant gasket for automobile exhaust pipe and joint structure using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant gasket for an automobile exhaust pipe, which is applied to seal a connecting portion between exhaust pipes of an automobile, and a joint structure using the same.

[0002]

2. Description of the Related Art Generally, a gasket of this type is formed in a ring shape or a spiral shape and is mounted as it is on a joint portion of a connecting pipe which constitutes an automobile exhaust pipe portion. As a joint structure of a connection pipe for automobiles that incorporates this gasket,
Conventionally known ones are as shown in FIGS.

In the structure shown in FIG. 16, a pair of flanges 16 is provided at each connection end of the connection pipes 161 and 162 connected to each other.
3, 164 are respectively fixed by welding 165, and the gaskets 167 are inserted into the annular groove 166 formed on the side surface of the one flange 163.
No. 64 is tightened and fixed with a bolt 168 and a nut 169. Further, in the structure shown in FIG. 17, the connection opening 171 of one connection pipe 161 is expanded and formed in a trumpet shape, and Connection pipe 162 flange 16
4, a conical gasket 172 is arranged between the two flanges 163 and 164 in the same manner as above.
It is fastened and fixed with 68 and a nut 169.
Further, in the structure shown in FIG. 18, a large-diameter receiving portion 181 is formed in an expanded manner at one end of the connecting pipe 162.
With the gasket 182 interposed between the inner surface of the above and the outer surface of the end portion of the other connecting pipe 161, the tightening ring 183 is tightened and fixed from the outer peripheral side of the receiving portion 181.

[0004]

Generally, in an automobile exhaust pipe, since high-temperature and high-pressure exhaust gas flows in a connecting pipe, the joint portion of the pipe and the gasket mounted therein have a high temperature from the inside of the pipe. Not only the high pressure acts, but also the vehicle body vibration and the engine vibration while the automobile is running act as bending stress on the joint portion and strongly act. In particular, the inside of the exhaust pipe is a portion where high-temperature combustion gas as high as 700 to 800 ° C. directly flows from the engine, and the vibration caused by the gas having a large pressure fluctuation corresponding to the output change of the engine cannot be ignored.

In the conventional joint structure having the above-mentioned construction using the gasket for automobile exhaust pipe used under the severe conditions as described above, the gasket 16 used therefor
No. 7, 172, 182 are arranged in the joint portion of the connecting pipes 161 and 162 in a molded state, so that if there is variation in processing accuracy when molding to a predetermined shape, both connecting pipes 161 It is difficult to accurately position in the radial direction with respect to 162.

Further, in the joint structure as shown in FIGS. 16 and 17, the joint portion is strongly affected by vibration of the vehicle body and accordingly.
Secure enough strength to withstand flexural stress
And the opposite flanges 163 and 164 with bolt 1
Gasket by tightening and fixing with 68 and nut 169
Seals the high temperature and high pressure exhaust gas to the parts 167 and 172
In order to give a sufficiently high tightening surface pressure,
Separate from the connecting pipes 161, 162 to be connected to each other,
The flanges 163 and 164 having a larger wall thickness than the connecting pipes 161 and 162 are welded and fixed to the connecting pipes 161 and 162.
In addition to increasing the complexity of the joint structure and cost , it also requires weight reduction.
It is not preferable as an exhaust pipe joint for automobiles. Ma
In addition, in a joint having such a heavy structure, the connecting pipe 1
If the 61, 162 are not centered together, the effect of vibration of the joint part due to the flow of high temperature combustion gas is
Gasket 167,172 is directly transmitted to 7,172.
Will be deformed. On the other hand, the joint structure shown in FIG. 18 has end portions of the connecting pipes 161 and 162 to be connected to each other.
It has a simple and lightweight structure that expands and forms
It is very effective in reducing the vehicle weight and making the car lighter.
On the other hand, it is difficult to secure the tightening surface pressure of the gasket.
In addition, the gasket 182 is connected to the connecting pipe 16 due to strong vibration.
1, 162 is easily subjected to bending stress, which causes deformation of the gasket 182, which results in stable shearing over a long period of time.
There is a problem that it is difficult to maintain the role function .

The present invention has been made in order to solve the above-mentioned problems, and does not simplify the joint structure and reduce the weight thereof.
Unwilling also, the high temperature in the connection pipe, when possible to avoid the influence of the bending stress due to vibration caused by the flow of high-pressure exhaust gas together
In addition, it is possible to increase the sealing area and increase the tightening surface pressure.
It is an object of the present invention to provide a heat resistant gut for automobiles and a joint structure using the same, which can maintain a stable sealing function for a long period of time .

[0008]

In order to achieve the above object, a heat-resistant gasket for an automobile exhaust pipe according to the invention of claim 1 is constructed by winding a stainless steel strip and a mica sheet into a plurality of layers and winding them in a spiral shape. Are connected to each other
Connected to the enlarged stepped part of each end of the connecting pipe and outward in the radial direction
It is bent and sandwiched between slanted flanges facing each other.
On the inner peripheral side of the gasket body, a rigid tubular body, which is wider than the gasket body and whose axial ends are fitted into the connecting pipe, is integrally provided , and the shaft of the gasket body is
Both end faces in the core direction spread toward the inner circumference from the outer circumference
Is formed in an inclined shape .

In the joint structure using the heat-resistant gasket for automobile exhaust pipe according to the second aspect of the present invention, the ends of the connecting pipes connected to each other face each other radially outward.
Each of the slanted flanges is formed by bending, and the stainless steel strip and the mica sheet are polymerized into a plurality of layers and wound in a spiral shape , and both end faces in the axial direction are formed from the outer peripheral side.
Inclined flange of the inner peripheral side the gasket body in heat gasket made integrally provided on the wide rigid cylindrical body on the inner peripheral side of the gasket body formed diverging angled toward the opposite of the connection tube It is located between the parts, and the rigid cylinder is fitted into the connecting pipe, and the outer periphery of the flange part is clamped.

A heat-resistant gasket for an automobile exhaust pipe according to a third aspect of the present invention is a heat-resistant gasket for an automobile exhaust pipe, which is formed by spirally winding a molding material composed of a tubular body braided with stainless wire and a mica sheet or an expanded graphite sheet inserted into the tubular body. Enlarged step at each end of the connecting pipe, which is formed by molding in a circular shape and is connected to each other
Are connected to each other and bent outward in the radial direction to form a pair.
On the inner peripheral side of the gasket main body sandwiched between the facing inclined flanges, a rigid cylindrical body having a width wider than that of the gasket main body and axial ends of which is fitted in the connecting pipe is integrally provided. And both end surfaces of the gasket body in the axial direction are the outer circumference
Is formed in a sloping shape that widens toward the inner side from the side
Is what it is.

Further, in the joint structure using the heat resistant gasket for an automobile exhaust pipe according to the invention of claim 4, inclined flange portions facing each other outward in the radial direction are provided at respective end portions of the connecting pipes connected to each other. Each of which is formed by bending, and is formed by spirally shaping a molding material composed of a tubular body braided with a stainless steel wire and a mica sheet or an expanded graphite sheet inserted into the tubular body , and the shaft thereof. Both in the core direction
The end surface has a sloping shape that widens toward the inner circumference from the outer circumference.
In a heat-resistant gasket in which a wide rigid cylinder is integrally provided on the inner peripheral side of the formed gasket main body, the gasket main body is located between the inclined slanted flange portions of the connecting pipe, and the rigid cylindrical body Is fitted in the connection pipe, and the outer periphery of the collar portion is clamped.

[0012]

According to the inventions of claims 1 and 3, the gasket body is formed by superposing a stainless steel strip and a mica sheet in a plurality of layers, or a tubular body in which stainless steel wire is braided, and the tubular body. The molded material consisting of the mica sheet or expanded graphite sheet inserted into the gasket is molded into a spiral shape, so the gasket itself has high rigidity and heat resistance, and the gasket body has a wide width on the inner peripheral side. By providing the rigid tubular body integrally, even if there is variation in the processing accuracy of the gasket body, by fitting both ends of the rigid tubular body in the axial direction into the connecting pipe, the gasket can be attached to the connecting pipe. And can be accurately positioned in the radial direction. Besides, the shaft of the gasket body
Both end faces in the core direction spread toward the inner circumference from the outer circumference
Since it is formed in an inclined shape, the sealing area can be expanded.
Both the slanted shape that provides a wide sealing area
The end faces are connected to each other and are formed at each end of the connecting pipe.
The structure is such that it is sandwiched between the slanted flanges facing each other.
This allows the gasket to be used even if a structurally simple clamp is used.
It is possible to secure a high tightening surface pressure of the hood.

Further, according to the inventions of claims 2 and 4, a joint structure using a heat-resistant gasket composed of a gasket body having excellent rigidity and heat resistance as described above, and connecting separate flanges Instead of welding and fixing to the pipe, the ends of the connecting pipe face each other radially outward
Since slanted flange portions each has a configuration which is formed bent, simplified joint configuration, cost reduction and weight reduction Contact
And structurally simple while supporting the weight reduction of automobiles
Tightening surface pressure against the gasket body using a simple clamp
It is possible to increase the temperature, and a stable sealing machine for a long period of time.
Noh can be maintained. In addition, since the rigid cylindrical body of the gasket is fitted to the connecting pipe, the connecting pipe can be easily centered, and the strong bending stress acting on the connecting pipe due to the vibration associated with the flow of exhaust gas while the vehicle is running is rigid. It is possible to avoid the adverse effect such that the gasket body is received and supported by the cylindrical body and the gasket main body is deformed by bending stress, and the sealing function is deteriorated.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a heat resistant gasket for an automobile exhaust pipe according to an embodiment of the present invention.

In FIG. 1, the heat-resistant gasket 1 comprises a ring-shaped gasket body 2 and a rigid cylindrical body 3 integrated on the inner peripheral side thereof. The width (length in the axial direction) D of the rigid cylinder 3 is set to be larger than the width d of the gasket body 2. Said gasket body 2, for example, is configured by turning mica sheet 2B and wound into spiral shape by polymerizing a plurality of layers of the stainless steel strip (SUS316) 2A and a filler material as a hoop material, and this
Both end surfaces of the gasket body 2 in the axial direction are from the outer circumference to the inner circumference.
It is formed in an inclined shape that widens toward the side .

The heat-resistant gasket 1 is obtained by welding and fixing one end of the stainless steel strip 2A to the outer peripheral surface of the rigid cylindrical body 3,
It is manufactured by winding it around the outer periphery of the rigid cylindrical body 3 in a spiral shape together with the mica sheet 2B while deforming it into a corrugated shape.

In such a heat-resistant gasket 1,
Since the rigid cylindrical body 3 having the wide width D is integrated on the inner peripheral side of the gasket body 1, the connecting pipe 2 that constitutes the exhaust pipe of the automobile is formed.
By fitting both ends of the rigid cylindrical body 3 in the axial direction into the pipes 1 and 22 (FIG. 2), the radial positioning with respect to the connecting pipes 21 and 22 can be easily performed.

[0018] Figure 2 shows a joint structure using the heat-gasket 1, in the figure, the ends mutually respective adjacent connecting pipes 21 and 22, respectively stepped portions 21a, 22a are formed, these stepped portions 21a and 22a, the sloping flanges 21 that are expanded and bent outward in the radial direction to face each other.
b and 22b are formed respectively. In the heat-resistant gasket 1, the rigid cylindrical body 3 is attached to the stepped portion 2 with the gasket body 2 sandwiched between the inclined flange portions 21b and 22b.
It is fitted in the 1a and 22a. 23 is the collar 21
The clamp 23 is a clamp for fastening the outer circumferences of b and 22b. As shown in FIGS. 3 and 4, the clamp 23 includes a pair of upper and lower clamp pieces 23A and 24A and these clamp pieces 23A and 23A.
It is composed of a bolt 24 and a nut 25 for fastening both ends of 24A.

According to such a joint structure, since the rigid tubular body 3 of the heat-resistant gasket 1 is fitted into the connecting pipes 21 and 22, the connecting pipes 21 and 22 are connected by the rigid tubular body 3.
The centering and positioning of 2 can be easily performed. Moreover, since the end portions of the connecting pipes 21 and 22 are expanded and bent to form the inclined flange portions 21b and 22b without using a separate flange or the like , the joint portion structure is simplified and the weight is reduced. , cost reduction is FIG. Further , the heat-resistant gasket 1 is excellent in rigidity and heat resistance, and the slanted flange portions 21b, 22 are provided.
Both end faces in the axial direction of the gasket body 2 sandwiched between b
Is formed in a sloping shape that widens toward the end,
Area is obtained and the sloping collars 21b, 22 are provided.
Increase the tightening surface pressure to the gasket body 2 via b.
Further , due to the vibration generated in the connection pipes 21 and 22 as the high-temperature and high-pressure exhaust gas flows in the exhaust passage formed by the connection pipes 21 and 22, the connection pipes 21 and 22 are connected. Since the rigid cylindrical body 3 acts as a reinforcing / supporting body against the bending stress acting on the gasket body 2 and prevents the gasket body 2 from being deformed, a predetermined sealing function is maintained as a whole .

The clamp 23 is not limited to the one shown in FIGS. 3 and 4, and for example, as shown in FIG. 5, one end of each of clamp pieces 23A and 23B is rotatably connected by a pin 52 to a clamp 52. As shown in FIG. 6 and FIG. 6, a plurality of clamp pieces 61A, 6 which are connected so as to be expandable and contractable in the radial direction.
It is possible to use a clamp 62 having 1B, 61C and 61D.

FIG. 7 shows a heat-resistant gasket 1 for an automobile exhaust pipe in another embodiment of the present invention, and FIG. 8 shows a joint structure using the heat-resistant gasket 1.

In FIGS. 7 and 8, reference numeral 71 is a gasket body made of a metal wire composite seal material, and more specifically, a tubular body 71A made by knitting a stainless wire.
And a mica sheet or an expanded graphite sheet 71B inserted in the tubular body 71A, and the rigid tubular body 3 is integrally provided on the inner peripheral side thereof in the same manner as in the above embodiment. Thus, the same effect as that of the above embodiment can be brought out.

The gasket body 71 is manufactured as follows. A stainless wire (SUS316) having a linear shape of about 0.15 mm is knitted as shown in FIG. 9 to form a tubular body 71A, and a mica sheet or an expanded graphite sheet 71B is formed inside the tubular body 71A. The strip-shaped molding material 71C is formed by inserting. This molding material 7
After forming 1C into a spiral shape as shown in FIG.
This is preformed by a preforming die 110 shown in FIG. This preforming die 110 is installed in a bottom die 110A and has a core die 110B into which the molding material 71C is fitted.
And a pressing die 110D which is fitted between the outer die 110C and the core die 110B and presses the molding material 71C. The molding material 71C is preformed by the mold 110 to form a ring-shaped molding 71D as shown in FIG.
Is obtained. Then, as shown in FIG. 13, the molded body 71D is externally fitted to the rigid cylindrical body 3 supported by the bottom mold 130A of the main molding die 130, and in this state, the molded body 71D is pressed by the pressing mold 130B. By pressing, a gasket body 71 integrated with the rigid tubular body 3 is obtained as shown in FIG. 7.

As shown in FIG. 14, the gasket body 2 (71) may be reinforced by a reinforcing ring 141 to be fixed to the rigid tubular body 3, or as shown in FIG. It is also possible to use the conical gasket body 151.

By the way, as the constituent material of the hoop materials 2A and 71A used for the gasket bodies 2 and 71, other than the above materials, other SUS304, SUS310S or the like can be used, and the filler material 2B and the sealing material 71B can also be used. In addition to mica sheets and expanded graphite, inorganic fibers such as ceramic fibers and rock wool, or inorganic powders such as talc, mica, vermiculite and sepiolite can be used in combination. Among them, when mica is used in combination, phlogopite (phlogopite) has high heat resistance and is optimal as a constituent material of the gasket body.

[0026]

As described above, claims 1 and 3 are as described above.
According to the invention, not only the gasket body having excellent rigidity and heat resistance is used, but also the rigid cylinder is integrally provided on the inner peripheral side of the gasket body. Instead, the radial positioning with respect to the connecting pipe can be easily and accurately performed via the rigid cylindrical body. Moreover, the axial direction of the gasket body
Both end faces in the opposite direction are flared toward the inner circumference from the outer circumference.
Since it is formed in a slanted shape, if you increase the seal area
In both cases, the slanted end faces, which have a large sealing area, are connected to each other.
Formed to face each other at each end of the connecting pipe connected to
It is configured to be sandwiched between the inclined slanted collars
Of the gasket while using a structurally simple clamp.
The tightening surface pressure is increased and the sealing function is stable for a long time.
Can be maintained.

Further, according to the invention of claims 2 and 4, a heavy flange separate from the connecting pipe is welded to the connecting pipe.
Rigid collar that bends the end of the connecting pipe instead of fixing it
Is formed , and the gasket body of a heat-resistant gasket in which a rigid tubular body is integrated on the inner peripheral side of the gasket body having excellent rigidity and heat resistance as described above is sandwiched between the opposed inclined flange portions, and The rigid cylinder was fitted into the connecting pipe, and the flange was clamped to secure the joint structure.
While simplifying, lightening, and lowering the cost of
As mentioned above, securing a wide sealing area and high tightening surface pressure
With a synergistic action with
It is possible to maintain, it can also be Nau easily row centering and positioning of the connecting tube by the rigid cylindrical body
It Moreover, the rigid cylinder receives the bending stress acting on the connecting pipe due to the strong vibration associated with the flow of high-temperature and high-pressure exhaust gas, and avoids the bending stress from directly affecting the gasket body. It is possible to prevent the deformation of the material and further improve the original sealing performance .

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a heat-resistant gasket for an automobile exhaust pipe according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a joint structure using the above heat-resistant gasket.

FIG. 3 is a front view showing a clamp used in the above joint structure.

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

FIG. 5 is a front view showing another example of the clamp used in the joint structure.

FIG. 6 is a front view showing still another example of the clamp used in the joint structure.

FIG. 7 is a vertical sectional view showing a heat resistant gasket for an automobile exhaust pipe according to another embodiment of the present invention.

FIG. 8 is a vertical cross-sectional view showing a joint structure using the above heat-resistant gasket.

FIG. 9 is a perspective view showing a material for forming a gasket body of the above heat-resistant gasket.

FIG. 10 is a perspective view showing a state in which the same forming material is formed in a spiral shape.

FIG. 11 is a cross-sectional view showing a state in which the above molding material is molded by a preforming mold.

FIG. 12 is a perspective view showing a molded body molded by a preforming mold.

FIG. 13 is a cross-sectional view showing a state where the above-mentioned molded body is subjected to main molding with a main molding die.

FIG. 14 is a vertical cross-sectional view showing another example of a heat resistant gasket for an automobile exhaust pipe.

FIG. 15 is a vertical sectional view showing a conical gasket body.

FIG. 16 is a vertical sectional view showing a joint structure using a conventional heat-resistant gasket for an automobile exhaust pipe.

FIG. 17 is a vertical cross-sectional view showing a joint structure using another conventional heat-resistant gasket for automobile exhaust pipes.

FIG. 18 is a longitudinal sectional view showing a joint structure using another conventional heat-resistant gasket for automobile exhaust pipes.

[Explanation of symbols]

 1 Heat Resistant Gasket 2,71,151 Gasket Main Body 2A Stainless Steel Strip 2B Mica Sheet 3 Rigid Cylindrical Body 21,22 Connection Tube 21b, 22b Collar 23,52,62 Clamp 71A Stainless Steel Mesh 71B Mica Sheet or Expanded Graphite Sheet d Gasket Body width D Rigid cylinder width

Claims (4)

(57) [Claims] 1. A stainless steel strip and a mica sheet are polymerized into a plurality of layers and wound in a spiral shape, and are bonded to each other.
Connected to the enlarged stepped part at each end of the connecting pipe to be connected radially outward
Between the slanted flanges that are bent toward each other and face each other
On the inner peripheral side of the gasket body that is sandwiched between the rigid body, which is wider than the gasket body and whose axial ends are fitted into the connection pipe, is integrally provided .
Both end faces of the main body in the axial direction are directed from the outer circumference to the inner circumference.
A heat-resistant gasket for an automobile exhaust pipe, which is formed in a sloping shape that widens toward the end. 2. A radial direction at each end of the connecting pipes connected to each other .
The slanted flange portions facing each other toward the outward direction are respectively bent and formed, and the stainless steel strip and the mica sheet are polymerized into a plurality of layers to be wound in a spiral shape , and,
Both end faces in the axial direction spread toward the inner circumference from the outer circumference.
In a heat-resistant gasket in which a wide rigid cylinder is integrally provided on the inner peripheral side of the gasket body formed in a slanted shape, the gasket body is inclined with the connecting pipe facing each other.
It is positioned between Jo flange portion, and the rigidity cylinder body fitted to the connection pipe, joint structure using the heat gasket for automobile exhaust pipe, characterized in that the fastened clamp the outer periphery of the flange portion. 3. A connecting pipe which is formed by spirally molding a molding material composed of a tubular body braided with stainless steel wire and a mica sheet or an expanded graphite sheet inserted into the tubular body, and which is connected to each other. Connect to the expanded step at each end of
Heaps are formed radially outward and face each other
On the inner peripheral side of the gasket body sandwiched between the slanted flange portions, a rigid cylindrical body having a width wider than that of the gasket body and having both axial ends thereof fitted into the connecting pipe is integrally provided .
The end faces of the gasket body in the axial direction from the outer peripheral side
A heat-resistant gasket for an automobile exhaust pipe, characterized in that it is formed in an inclined shape that widens toward the inner peripheral side . 4. A radial direction at each end of the connecting pipes connected to each other .
A molding material composed of a tubular body in which inclined flange portions facing each other outward and outward are bent, and a stainless wire rod is braided, and a mica sheet or an expanded graphite sheet inserted into the tubular body. Is formed into a spiral shape , and both end faces in the axial direction are from the outer peripheral side to the inner peripheral side.
The gasket body of the heat-resistant gasket integrally formed with a wide rigid cylinder on the inner peripheral side of the gasket body is formed between the inclined flange portions facing each other of the connecting pipe. A joint structure using a heat-resistant gasket for an automobile exhaust pipe, characterized in that the rigid tubular body is fitted in the connecting pipe, and the outer periphery of the collar portion is clamped.