JP2003056341A - Exhaust pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust pipe joint capable of reducing a producing cost while sufficiently ensuring expandability and heat resistance. SOLUTION: This exhaust pipe joint 10 is formed in a four layer structure provided in order from an inner periphery side with a first layer 12 formed by a stainless plate material wound in a cylindrical shape and fitted around an outer periphery of a connecting part of exhaust pipes 11A and 11B, a second layer 13 formed by stainless foil wound in a cylindrical shape, a third layer 14 formed by ceramics wool wound in a cylindrical shape, and a fourth layer 15 formed by glass fiber fabric wound in a cylindrical shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe joint for connecting ends of two exhaust pipes.

[0002]

2. Description of the Related Art The temperature of an exhaust pipe for exhausting exhaust gas from an internal combustion engine to the outside is 500 ° C. or higher during operation of the internal combustion engine, but drops to the outside air temperature after the engine is stopped. Since the exhaust pipe length changes greatly due to thermal expansion and contraction due to such temperature changes, it is necessary to interpose an expandable joint that absorbs the change in the exhaust pipe length between the portion where the exhaust pipe is fixed.

As such an exhaust pipe joint, a bellows pipe made of metal (for example, stainless steel) or an actual flat plate 6-607 is used.
As can be seen in Japanese Patent Publication No. 29, a heat-resistant material such as glass fiber or ceramic fiber whose outer periphery is covered with an elastic material such as rubber is known.

[0004]

However, these conventional exhaust pipe joints have some problems in terms of manufacturing cost as described below.

First, a joint using a metal bellows tube is manufactured by plastically working a metal into a bellows shape, and therefore the manufacturing cost thereof becomes high. Further, since such a plastic working requires a dedicated die, it is particularly unsuitable for the production of various small quantities.

Further, in the joint using the metal bellows tube,
In order to ensure durability against thermal fatigue, it is necessary to make the wall thickness thick to a certain extent, and the deformation resistance becomes large, so that the stretchability cannot be increased so much. for that reason,
It becomes necessary to firmly fix the exhaust pipe, and the cost of fixing the exhaust pipe cannot be ignored. Further, due to such a fixed structure, there are restrictions on the layout of the exhaust pipe installation.

On the other hand, even in the joint in which the heat-resistant material is covered with the elastic material, a dedicated die is required for molding the elastic member, and thus the manufacturing cost is also increased. Of course,
Especially unsuitable for small-lot production of a wide variety. Further, although the elastic member such as rubber is not so high in heat resistance and the heat resistant material is interposed, the deterioration of durability due to the thermal deterioration of the elastic member which becomes a considerably high temperature due to the heat of the exhaust gas is also ignored. It is not possible.

The present invention has been made in view of such circumstances, and an object thereof is to provide an exhaust pipe joint capable of keeping manufacturing cost low while ensuring sufficient stretchability and heat resistance. It is in.

[0009]

[Means for Solving the Problems] Means for achieving the above-mentioned objects and their effects will be described below. The invention according to claim 1 is an exhaust pipe joint that joins ends of two exhaust pipes, and is formed by a metal plate material that is loosely fitted to the outer periphery of the joint portion of the exhaust pipes and is wound in a tubular shape. First done
Layer, and a second layer formed by covering the outer periphery of the first layer and formed by a metal foil wound in a tubular shape, and arranged so as to cover the outer periphery of the second layer. And a third layer formed of a heat insulating material that is wound in a tubular shape.

In the above structure, the exhaust gas is sealed by the second layer formed of the metal foil. Since the metal foil is thin, it has high flexibility. Therefore, the exhaust pipe joint is
It can easily expand and contract in the axial direction and can flexibly absorb the thermal expansion and contraction of the exhaust pipe. In addition, since the first layer formed by the metal plate wound in a tubular shape is interposed between the first layer and the connecting portion of the exhaust pipe, the metal foil is directly exposed to high-temperature and high-pressure exhaust gas. It is also easy to secure its durability. Further, the heat insulating material provided on the outer periphery of the metal foil can suitably suppress the heat radiation of the exhaust gas to the outside.

Moreover, since the exhaust pipe joint is manufactured by winding the metal plate, the metal foil, and the heat insulating material in a tubular shape, the exhaust pipe joint can be manufactured at a low cost. Moreover, since it is not necessary to perform a forming process using a dedicated mold or the like, it is possible to easily manufacture exhaust pipe joints having different shapes and sizes, and it is possible to easily cope with a wide variety of small-volume production.

According to a second aspect of the present invention, in the exhaust pipe joint according to the first aspect, the two tubular bodies formed by winding the metal foil in a tubular shape have portions overlapping each other. By connecting the exhaust pipe in the axial direction, the second
Layer is formed, and the respective cylinders are fixed to one and the other of the connected exhaust pipes, respectively.

In the above structure, since the two foils slide in the axial direction, the metal foil expands and contracts in the axial direction.
The displacement due to the thermal expansion and contraction of the exhaust pipe can be absorbed without causing the metal foil to bend or break. Therefore, it is possible to avoid the occurrence of tears in the metal foil due to fatigue caused by repeated heat expansion and contraction of the exhaust pipe and repeated bending, and it is possible to further improve the durability of the exhaust pipe joint.

According to a third aspect of the present invention, in the exhaust pipe joint according to the first aspect, two substantially rectangular metal foils are wound in a tubular shape with their one ends being overlapped with each other.
The second layer is formed by connecting two cylinders in the axial direction, and the cylinders are fixed to one and the other of the connected exhaust pipes, respectively.

In the above structure, since the two foils slide in the axial direction relative to each other, the metal foil expands and contracts in the axial direction.
The displacement due to the thermal expansion and contraction of the exhaust pipe can be absorbed without causing the metal foil to bend or break. Therefore, it is possible to avoid the occurrence of tears in the metal foil due to fatigue caused by repeated heat expansion and contraction of the exhaust pipe and repeated bending, and it is possible to further improve the durability of the exhaust pipe joint. Further, the second layer composed of such two tubular bodies made of metal foil can be easily formed.

According to a fourth aspect of the present invention, in the exhaust pipe joint according to the second or third aspect, the two tubular bodies are connected to each other with their axial ends folded together. is there.

In the above structure, since the metal foils are folded together at the joint between the two metal foil cylinders, the leak path of the exhaust gas through the joint is complicated and the exhaust gas The amount of leakage can be reduced.

Further, the invention according to claim 5 is based on claim 1
The exhaust pipe joint according to Item 4 further includes a fourth layer formed of a heat-resistant cloth wound in a tubular shape and arranged so as to cover the outer periphery of the third layer.

In the above structure, the heat insulating cloth is covered to protect the heat insulating material and the like from damage, so that the durability of the exhaust pipe joint can be further improved. According to a sixth aspect of the present invention, in the exhaust pipe joint according to the first to fifth aspects, a winding joint portion of each of the layers is formed so that at least a winding joint of a layer adjacent to the winding portion is the exhaust pipe. It is arranged so as not to be in the same phase around the axis.

Since each layer of the exhaust pipe joint is formed by winding it in a tubular shape, a winding joint portion is formed in each layer, and exhaust gas easily leaks through the joint portion. On the other hand, in the above structure, the phase of the winding joint portion is shifted at least between the adjacent layers, so that the amount of exhaust gas leaking through the joint portion can be reduced.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a side sectional structure of a joint portion of an exhaust pipe joined by an exhaust pipe joint of this embodiment, and FIG. 2 shows a sectional structure taken along line II of FIG. .

As shown in FIGS. 1 and 2, the exhaust pipe joint 10 of the present embodiment is formed in a substantially hollow cylindrical shape, and the exhaust pipes 11A and 11B are respectively inserted from both ends thereof and joined to each other. Has become. In this joint 10, the exhaust pipes 11A and 11B have a distance of 10 m between their end faces.
They are joined in a state where they are coaxially arranged with a gap L of about m.

The exhaust pipe joint 10 has a four-layer structure. The first layer at the innermost circumference of the exhaust pipe joint 10 located immediately outside the exhaust pipes 11A and 11B is formed by a metal plate member 12 wound in a tubular shape. This plate material 12
For this, a plate material made of stainless steel having a thickness of 0.3 mm is used. The plate member 12 is arranged so as to cover the gap L between the exhaust pipes 11A and 11B, and its inner diameter is formed to be slightly larger than the outer diameter of the exhaust pipes 11A and 11B. As a result, the plate member 12 is loosely fitted to the end portions of the exhaust pipes 11A and 11B and is allowed to slide relative to them in the axial direction.

The second layer on the outer side is formed by a metal foil material 13 wound in a tubular shape. This foil material 13
Is a stainless steel foil having a thickness of 10 to 50 μm. Stainless foil has high heat resistance (heat resistant temperature 1200
Of course, it is also highly flexible due to its thinness. In this embodiment, as will be described later, the foil material 1
3 is formed by connecting two cylinders formed by winding stainless steel foil in a tubular shape in the axial direction. In this exhaust pipe joint 10, mainly by this foil material 13,
The exhaust gas is sealed.

Further, the third layer located on the outer circumference is formed by the heat insulating material 14 wound in a tubular shape. Here, as the heat insulating material 14, ceramic wool having a thickness of about 6 mm is used. Ceramic wool is a cotton-like material made of ceramic fibers and is heat resistant (heat resistant temperature 150
(0 ° C), highly flexible. Further, due to the presence of the air layer formed between the ceramic fibers, it has a high heat insulating property. In this exhaust pipe joint 10, the heat of the exhaust gas is insulated by the heat insulating material 14, and the amount of heat released to the outside is suppressed.

In this exhaust pipe joint 10, the heat insulating material 14 is arranged in a compressed state to some extent. Therefore, the foil material 13 receives appropriate pressure from the entire outer circumference,
The exhaust pipes 11A and 11B and the outer periphery of the plate member 12 are closely attached.

The fourth layer located on the outermost periphery is formed by the cloth material 15 wound in a tubular shape. Cloth material 15
Has a thickness of 0.5 made by weaving glass fiber threads.
~ 2mm glass fiber cloth is used. The glass fiber cloth has relatively high heat resistance (heat resistant temperature of 500 ° C.). The cloth material 15 is protected from the heat of the exhaust gas by the heat insulating material 14. With this exhaust pipe joint 10,
The cloth material 15 protects the heat insulating material 14 and the like from damage.

The foil material 13, the heat insulating material 14, and the cloth material 15 forming the second to fourth layers extend in the axial direction of the exhaust pipes 11A and 11B with respect to the plate material 12 forming the first layer. Has been done. The foil material 13, the heat insulating material 14, and the cloth material 15 are respectively fastened and fixed to the exhaust pipes 11A and 11B by stainless steel wires 16 in the vicinity of both ends in the axial direction.

1 and 2, the layers (12 to 15) of the exhaust pipe joint 10 and the exhaust pipes 11A and 11A.
Although it is depicted that there are large gaps between B, in reality, the structure is dense with almost no gaps.

The exhaust pipe joint 10 as described above is manufactured as follows. First, the manufacturing procedure of the foil material 13 forming the second layer will be described with reference to FIGS.

The foil material 13 is manufactured from two stainless steel foils 20 and 21 cut out in a rectangular shape. Here, on the plane where the stainless steel foils 20 and 21 are placed, the direction corresponding to the axial direction of the manufactured exhaust pipe joint 10 is referred to as the front-rear direction, and the direction orthogonal thereto is referred to as the left-right direction.

First, as shown in FIG. 3, each of the rectangular stainless steel foils 20 and 21 is folded back at a predetermined length from one end in the front-rear direction. Then, as shown in FIG. 4, the folded back end portions 20A and 21A are hooked on each other to form the stainless steel foil 2
0 and 21 are connected in the front-rear direction to form an integrated sheet as shown in FIG.

Subsequently, as shown in FIG. 6, the joined stainless steel foils 20 and 21 are folded back at predetermined lengths (lines L1 and L2 in FIG. 5) from the left and right ends thereof. At this time,
Left side (13L) and right side (13
R) and F) are folded back toward different surfaces.

Then, as shown in FIG. 7, the stainless steel foils 20 and 21 are wound in the left-right direction, and the folded portions 13L and 13R at the left and right ends are hooked to each other to form a cylindrical shape. Then, as shown in FIG. 8, the seam portions at the left and right ends of both stainless steel foils 20 and 21 are sewn together with a stainless thread. However, at that time, the stitching is not performed on the central portion in the axial direction which is the joint between the two stainless steel foils 20 and 21. In addition, the stainless thread was made by tying stainless fibers together,
It is a tough yarn with excellent heat resistance and flexibility.

From the above, the two stainless steel foils 20, 2 are
The tubular foil material 13 in which the cylinders formed from 1 are connected in the axial direction is manufactured. Foil material 13 manufactured in this way
As shown in FIG. 9 (a), the joints between the two stainless steel foils 20 and 21 are connected only by the folded end portions 20 </ b> A and 21 </ b> A being hooked to each other. 21 can be slid relative to each other in the axial direction, as shown in FIGS. 9 (b) and 9 (c).
Therefore, the manufactured tubular foil material 13 can be expanded and contracted with a small force in the axial direction.

Then, as shown in FIG. 10, the ceramic wool which is cut into a rectangular shape is wound so as to cover the outer periphery of the foil material 13 thus formed in a tubular shape, and the third exhaust pipe joint 10 is wound. The portion of the heat insulating material 14 that forms the layer of is formed.
Then, as shown in FIG. 11, a glass fiber cloth, which is also cut into a rectangular shape, is further wound around the outer circumference thereof to form a portion of the cloth material 15 which is the fourth layer of the exhaust pipe joint 10. Then, the seam of the cloth material 15 wound in a tubular shape is sewn with a stainless thread to form the foil material 13, the heat insulating material 14, and the cloth material 15 into an integral hollow cylindrical body.

When connecting the exhaust pipes 11A and 11B,
First, the plate member 12 is attached to the tip of one exhaust pipe 11A.
Further, a foil material 13 formed in an integral hollow cylindrical body so as to cover the tip portion of the exhaust pipe 11A to which the plate material 12 is attached,
The heat insulating material 14 and the cloth material 15 are attached. Then, the other exhaust pipe 11B is inserted from the side opposite to the side where the exhaust pipe 11A is mounted in the hollow cylindrical body, and the exhaust pipe 11B is made of a plate material while leaving a gap of a predetermined length L with the exhaust pipe 11A. Fit to 12. Further, at both axial ends of the cloth material 15, the foil material 1
3, the heat insulating material 14 and the cloth material 15 are made of stainless steel wire 16
Then, the exhaust pipes 11A and 11B are fastened and fixed respectively. As described above, the exhaust pipes 11A and 11B are connected.

Each layer (12 to 1) of the exhaust pipe joint 10 is
5) is formed by winding a rectangular material in a tubular shape, and the joints of the winding are present in all of these layers. Therefore, the exhaust gas easily leaks through the joint portion of such winding. In view of this, in the present embodiment, as shown in FIG. 2, the phases around the axes thereof are shifted so that the winding joints of at least adjacent layers do not overlap. By doing so, it is possible to reduce the leakage of exhaust gas through such joints of winding.

Now, in such an exhaust pipe joint 10, as described above, the two stainless steel foils 20 connected in the axial direction,
The cylindrical bodies 21 are slid in the axial direction, so that the foil body 13 wound in a tubular shape can easily expand and contract in the axial direction even with a small force. Furthermore, the heat insulating material 14 and the cloth material 15 are materials having high flexibility. Therefore, the exhaust pipe joint 10 can flexibly absorb the thermal expansion and contraction displacement of both the exhaust pipes 11A and 11B with almost no resistance.

By the way, if the stainless steel foils 20 and 21 bend due to the expansion and contraction of the foil material 13 and are twisted or broken, the stainless steel foils 20 and 21 are fatigued by the repetition.
There may be a tear at 21. In this respect, in the exhaust pipe joint 10, since the stainless steel foils 20 and 21 slide on each other, the foil material 13 expands and contracts in the axial direction.
The stainless foils 20 and 21 can absorb the displacement due to the thermal expansion and contraction of the exhaust pipes 11A and 11B with almost no twisting or bending, and the durability thereof can be kept high.

In this exhaust joint 10, the exhaust gas is mainly sealed by the foil material 13. Exhaust gas hardly passes through the stainless steel foils 20 and 21 and leaks. However, the foil material 13 is manufactured by connecting two cylindrical bodies formed by separate stainless steel foils 20 and 21 so as to be capable of expanding and contracting in the axial direction, and exhaust gas is emitted from the joint portion. It leaks to some extent.

However, at the joint between both stainless steel foils 20 and 21, the folded back end portions 20A and 21A are overlapped with each other, and the leak path of such exhaust gas is
As shown by the arrow in FIG. 12, it has a complicated shape. As a result, the exhaust gas is often
While repeating the direction change of 80 °, it will pass through the joint, and kinetic energy will be lost and pressure will be reduced during the passage. As a result, leakage of exhaust gas through such joints is sufficiently suppressed.

By constructing the exhaust pipe joint 110 as shown in FIG. 13, the exhaust gas sealing performance can be further improved. In this exhaust pipe joint 110, two layers each of the foil material 13 forming the second layer of the exhaust pipe joint 10 and the heat insulating material 14 forming the third layer thereof are provided. That is, the exhaust pipe joint 110 includes the plate material 12 and the first foil material 1 in order from the inner circumference.
3a, the 1st heat insulating material 14a, the 2nd foil material 13b, the 2nd heat insulating material 14b, and the cloth material 15 are formed in 6 layer structure.

FIG. 14 shows both exhaust pipe joints 10 and 1 described above.
10 shows the results of the durability test performed on No. 10. In this endurance test, a constant flow rate in the exhaust pipes 11A, 11B (while expanding and contracting the exhaust pipe joints 10, 110 with an amplitude of 5 mm while repeatedly giving a relative displacement in the axial direction of 5 mm to both the exhaust pipes 11A, 11B) 1240 nano cubic m /
Exhaust gas flow for 10 seconds), during which the exhaust pipe joint 10,1
It is performed by measuring the flow rate of the exhaust gas leaked from 10.

The vertical axis of the graph shown in FIG. 14 indicates the exhaust pipe 1.
The ratio (%) of the flow rate of the leaked exhaust gas to the flow rate of the exhaust gas passed through 1A and 11B is shown, and the horizontal axis thereof shows the number of relative displacements given to both exhaust pipes 11A and 11B, respectively. In addition, here, the foil material 13 and the heat insulating material 1
Exhaust pipe joint 10 with 1 layer each of 4 layers 1 PL
Exhaust pipe joint 11 that is called Y product and that is made of two layers.
0 is called 2PLY product.

As shown in FIG. 14, the exhaust gas leakage rate is 1 PL even after 5000 relative displacements are applied.
The exhaust pipe joint 10 of the Y product has approximately 1.7%, and the exhaust pipe joint 110 of the 2PLY product has approximately 1.0%. As is clear from the results of this durability test, these exhaust pipe joints 10 and 110 have both high durability and high sealing performance.

The effects produced by the above embodiment will be described below. (1) In the present embodiment, the first layer (12), which is formed by winding a stainless steel plate in a cylindrical shape and loosely fits the outer circumference of the connection portion of the exhaust pipes 11A and 11B, and the stainless steel foils 20 and 21 are formed in a cylindrical shape. A second layer (13) which is formed by winding and is arranged so as to cover the outer periphery of the first layer, and a ceramic wool that is formed by winding in a cylindrical shape so as to cover the outer periphery of the second layer. An exhaust pipe joint 10 is formed with a third layer (14) arranged. In such an exhaust pipe joint 10, exhaust gas is sealed and heat-insulated by using a thin and highly flexible stainless steel foil and a ceramic wool having a higher flexibility, respectively, and easily with a small axial force. It can be expanded and contracted. Thereby, the thermal expansion and contraction of the exhaust pipes 11A and 11B can be flexibly absorbed.

(2) Since the stainless steel plate 12 wound in a cylindrical shape is interposed between the connecting portion of the exhaust pipes 11A and 11B and the foil material 13, the stainless steel foil is directly exposed to high-temperature and high-pressure exhaust gas. It is not exposed and its durability is easy to secure.

(3) The exhaust pipe joint 10 of this embodiment is
It is manufactured by winding a stainless plate, stainless foil, and ceramics wool in a tubular shape, and can be manufactured without performing a forming process using a dedicated mold or the like. For example, scissors for cutting those stainless steel plates, stainless foil and ceramics wool, and glass fiber cloth,
The exhaust pipe joint 10 can be manufactured if there is an industrial sewing machine for sewing with a stainless thread. Further, if the shape and size for cutting them are changed, even exhaust pipe joints having different shapes and sizes can be easily manufactured, and it is possible to easily cope with various types of small-quantity production.

(4) Since the two tubular bodies formed by the two stainless steel foils 20 and 21 slide in the axial direction with respect to each other, the foil material 13 expands and contracts in the axial direction. Exhaust pipes 11A, 1
The displacement due to thermal expansion and contraction of 1B can be absorbed. Therefore, the foil material 13 can be prevented from being damaged by fatigue, and the durability of the exhaust pipe joint 10 can be easily ensured.

(5) In the present embodiment, two substantially rectangular stainless steel foils 20 and 21 are wound in a tubular shape with their one ends being overlapped with each other, thereby joining the two tubular bodies in the axial direction. The foil material 13 is formed as a thing. Therefore, 2
It is possible to easily form the foil material 13 formed by connecting two stainless steel foil cylinders.

(6) In this embodiment, the stainless steel foil 2 is formed at the joint between the two stainless steel foils 20 and 21.
Since the ends of 0 and 21 are folded together, the leak path of exhaust gas through the joint is complicated,
The amount of leakage of exhaust gas can be reduced.

(7) In this embodiment, a fourth layer (15) formed by cylindrically winding a glass fiber cloth is further provided so as to cover the outer periphery of the heat insulating material 14. By covering the outside with the glass fiber cloth in this manner, the heat insulating material 14 and the like can be protected from damage and the durability of the exhaust pipe joint 10 can be further enhanced.

(8) In this embodiment, each layer (12 to 1)
Since the phase of the joint portion of the winding of 5) is shifted, the leak amount of exhaust gas through such joint portion can be reduced.

The embodiment described above can be modified as follows. -In the above embodiment, the exhaust pipes 11A and 11B to be connected are connected.
In addition, the exhaust pipe joint 10 is directly provided,
As shown in FIG. 15, a pipe 11 with two flanges
The end portions of 1A and 111B may be connected to each other by the exhaust pipe joint 10 to be manufactured as an integral unit. Then, the exhaust pipes are connected by forming flanges at the ends of both the exhaust pipes to be connected and connecting them to the pipes 111A and 111B respectively by bolts or the like. In such a case, replacement work can be performed more easily when the exhaust pipe joint 10 deteriorates due to long-term use.

In the above embodiment, the stainless foils 20 and 21 are axially connected by hooking the folded back end portions (20A and 21A) to each other, thereby allowing the sliding in the axial direction. However, for example, FIG.
As described above, the ends of both stainless steel foils 20 and 21 can be folded and connected. In this case also, both stainless steel foils 20 and 21 can be easily slid in the axial direction, and the thermal expansion and contraction of the exhaust pipes 11A and 11B can be flexibly absorbed. Further, in this case, the leak path of the exhaust gas through the joint can be made more complicated, and the leak amount of the exhaust gas can be further reduced. In addition, if the folding method is a folding method that allows the both stainless steel foils 20 and 21 to slide in the axial direction, it is possible to maintain both the stretchability and the sealability of the exhaust pipe joint 10 at a high level. it can.

Also, the ends of both stainless steel foils 20 and 21 may be joined together simply by overlapping the ends without folding them. Even in that case, by sliding both stainless steel foils 20 and 21, the foil material 13 can be easily expanded and contracted with a small force.

Further, the foil material 13 may be formed by winding one stainless foil in a tubular shape. Even in this case, since the stainless steel foil is thin and highly flexible, it can be expanded and contracted with a small force, and the thermal expansion and contraction of the exhaust pipes 11A and 11B can be flexibly absorbed. Moreover, in this case, since the foil material 13 is formed of one piece of stainless steel foil and there is no joint except for the joint of winding, the sealing property of the exhaust pipe joint 10 can be made very high. it can.

A metal material other than stainless steel may be used as the material of the plate material 12 and the foil material 13 forming the first and second layers of the exhaust pipe joint 10. It is to be noted that, as those materials, high heat resistance is required, and since they are exposed to exhaust gas, it is preferable to use metal materials that are also highly resistant to corrosion.

As the heat insulating material 14 forming the third layer of the exhaust pipe joint 10, a material other than ceramic wool may be used. For such a heat insulating material, it is desirable to use a material having high heat resistance and flexibility in addition to heat insulating properties. As such a heat insulating material, there is, for example, asbestos or glass wool obtained by hardening glass fiber into a cotton shape.

The cloth material 15 forming the fourth layer of the exhaust pipe joint 10 may be made of a material other than glass fiber cloth such as metal fiber cloth made by weaving metal threads. If the heat insulation of the exhaust gas by the heat insulating material 14 is sufficient, a material having not so high heat resistance may be used.

If it is not necessary to protect the heat insulating material 14 from damage, the fourth layer (15) of the exhaust pipe joint 10 is omitted, and the heat insulating material 14 constitutes the outer peripheral surface of the exhaust pipe joint 10. It may be done.

[Brief description of drawings]

FIG. 1 is a side sectional view of an exhaust pipe joint of an embodiment of the present invention.

FIG. 2 is a front sectional view of the exhaust pipe joint.

FIG. 3 is a perspective view showing a manufacturing process of an exhaust pipe joint.

FIG. 4 is a perspective view showing a manufacturing process of an exhaust pipe joint.

FIG. 5 is a perspective view showing a manufacturing process of an exhaust pipe joint.

FIG. 6 is a perspective view showing a manufacturing process of an exhaust pipe joint.

FIG. 7 is a perspective view showing a manufacturing process of an exhaust pipe joint.

FIG. 8 is a perspective view showing a manufacturing process of an exhaust pipe joint.

FIG. 9 is an enlarged cross-sectional view of a joint portion of a foil material.

FIG. 10 is a perspective view showing a manufacturing process of the exhaust pipe joint.

FIG. 11 is a perspective view showing a manufacturing process of the exhaust pipe joint.

FIG. 12 is an enlarged sectional view of a central portion of an exhaust pipe joint.

FIG. 13 is a side sectional view of the exhaust pipe joint of another embodiment of the present invention.

FIG. 14 is a graph showing the results of an endurance test of an exhaust pipe joint.

FIG. 15 is a side sectional view of a further embodiment of the invention.

[Explanation of symbols]

10, 110 ... Exhaust pipe joint, 11A, 11B ... Exhaust pipe, 12 ... Stainless plate (metal plate material), 13, 13
a, 13b ... Stainless foil (metal foil material), 14, 1
4a, 14b ... ceramics wool (heat insulating material), 15 ...
Glass fiber cloth (cloth material), 16 ... Stainless steel wire, 2
0,21 ... Stainless steel foil.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiro Moriyama             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Bunji Murai             2-18 Misonocho, Gifu City, Gifu Prefecture Murai Sho             Inside the corporation (72) Inventor Yukihiro Harada             4-46 Yamanote, Toyota City, Aichi Stock Association             Company Toyota Turbine and System F term (reference) 3G004 BA00 BA05 DA11 DA14 EA03                       EA04 EA05 FA01 FA04 FA07                       GA00                 3H104 JA08 JB02 JC04 JC08 JD03                       KA04 KB20 LB35 LB38 LG03                       LG25 MA06

Claims (6)

[Claims] 1. An exhaust pipe joint for joining ends of two exhaust pipes to each other, wherein the exhaust pipe joint is loosely fitted to the outer periphery of the joints of the exhaust pipes, and is formed of a metal plate material wound in a tubular shape. Layer, a second layer which is arranged so as to cover the outer periphery of the first layer and which is formed by a metal foil wound in a tubular shape, and a second layer which is arranged so as to cover the outer periphery of the second layer. And a third layer formed of a tubular wound insulation material. 2. The second layer is formed by joining two tubular bodies formed by winding the metal foil into a tubular shape and connecting the two tubular bodies in the axial direction of the exhaust pipe, the portions having overlapping portions. The exhaust pipe joint according to claim 1, wherein the respective cylinders are respectively fixed to one and the other of the connected exhaust pipes. 3. The second layer is formed by winding two metal foils, which are cut into a substantially rectangular shape, in a tubular shape in a state where one ends of the metal foils are overlapped with each other.
The exhaust pipe joint according to claim 1, wherein the two pipes are formed by connecting two pipes in an axial direction, and the pipes are fixed to one and the other of the connected exhaust pipes respectively. 4. The exhaust pipe joint according to claim 2, wherein the two tubular bodies are connected in a state where their axial ends are folded together. 5. The exhaust pipe joint according to claim 1, further comprising a fourth layer formed of a heat-resistant cloth wound in a tubular shape, the fourth layer being arranged so as to cover the outer periphery of the third layer. An exhaust pipe joint characterized by further having. 6. The winding joint portion of each layer is arranged such that at least the winding joint portion of the layer adjacent thereto is not positioned in the same phase around the axis of the exhaust pipe. The exhaust pipe joint according to any one of 1 to 5.