JPH09229263A - Ball joint structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a gasket by continuously maintaining the gasket to the heat resistant temperature or less. SOLUTION: A ball joint structure is a structure in which an upstream side pipe 10 and a downstream side pipe 20 are connected to each other by bolts 4 provided with springs through a first flange 13, a gasket 8 and a second flange 23. A gasket flange 9 having the approximately U-shaped section is not in contact with a large-diameter part 10a and a small-diameter part 10b of the upstream side pipe 10 and formed along the axial direction of the upstream side pipe 10. The gasket 8 is arranged on the side not facing the upstream side pipe 10 of the gasket flange 9 and between the first and second flanges 13, 23. Since this gasket 8 is not in contact with both pipes 10, 20, heat is not directly transmitted to the gasket 8 even if respective pipes 10, 20 are subjected to the high temperature by high-temperature exhaust gas to flow inside respective pipes 10, 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when connecting an upstream side pipe and a downstream side pipe, relatively displaces the upstream side pipe and the downstream side pipe to interrupt the vibration transmitted to the connecting point. Ball joint structure.

[0002]

2. Description of the Related Art Conventionally, a ball joint structure as shown in FIG. 9 has been known as a vibration isolation structure at a connecting portion when connecting two pipes. That is, the gasket 84 having a substantially hemispherical surface and the flange 8 having a bolt insertion hole are formed on the outer peripheral surface of the downstream end of the upstream pipe P1.
3 are provided. On the other hand, on the outer peripheral surface of the upstream end of the downstream pipe P2, there is provided a flange 93 having a bolt insertion hole and capable of contacting the substantially hemispherical surface of the gasket 84. Then, with both flanges 83, 93 arranged so as to face each other and the flange 93 being in contact with the substantially hemispherical surface of the gasket 84, the bolt 4 is inserted from the flange 93 side via the spring 2 and the nut on the flange 83 side. Fasten with 6. The bolt 4 is provided with a spring retainer 4a, and the spring 2 is disposed between the spring retainer 4a and the flange 93.

In such a ball joint structure, the flange 94 of the downstream pipe P2 is formed on the substantially hemispherical surface of the gasket 84.
Slidably contact each other, and the spring retainer 4a and the flange 93
Since the spring 2 is disposed between and, the displacement of the vehicle in all directions and the vibration of the upstream pipe P1 in each direction are prevented from being transmitted to the downstream pipe P2.

[0004]

However, in the above ball joint structure, since the gasket 84 is in contact with the upstream pipe P1, the high temperature exhaust gas flowing in the upstream pipe P1 raises the temperature of the upstream pipe P1. When the heat is applied, the heat directly reaches the gasket 84, and the gasket 84 may be heated to a temperature higher than its heat resistance temperature, which may impair its function.

Particularly, in the case of the exhaust manifold collecting pipe in which the upstream pipe P1 is mounted in the vicinity of the engine, the problem is serious because the temperature of the exhaust gas is considerably high. The present invention has been made in view of the above problems, and an object of the present invention is to provide a ball joint structure that constantly maintains the gasket at a heat resistant temperature or lower and improves the durability of the gasket.

[0006]

In order to solve the above-mentioned problems, the ball joint structure of the present invention has a first flange provided at the end of the upstream pipe and an end of the downstream pipe. A second flange provided and disposed between the first flange and the second flange,
A gasket whose contact surface with the flange is a substantially hemispherical surface, and the first flange and the second flange via the gasket so that the second flange can slide along the substantially hemispherical surface of the gasket. And a connecting tool for connecting the upstream side pipe and the downstream side pipe in a non-contact manner.

In such a ball joint structure, since the gasket is not in contact with the upstream side pipe or the downstream side pipe, even if each of the pipes is heated by the high temperature exhaust gas flowing inside the upstream side pipe and the downstream side pipe. , The heat does not reach the gasket directly.

Therefore, according to the ball joint structure of the present invention, the gasket can be constantly maintained below the heat resistant temperature,
The effect that the durability of the gasket is improved can be obtained.
Here, as described in claim 2, it is preferable that the end portion of the upstream pipe extends in the downstream direction to a position where the gasket passes through the gasket. In this case, since the end of the upstream pipe is formed so as to cover the gasket, the gasket does not come into direct contact with the high temperature exhaust gas flowing inside the upstream pipe. Therefore, the high temperature exhaust gas flowing inside the upstream pipe does not heat the gasket to a temperature higher than the heat resistant temperature, and the above effect can be more reliably obtained.

Further, according to a third aspect of the present invention, the first flange is provided with a gasket flange surrounding the upstream pipe with a gap, and the gasket faces the upstream pipe of the gasket flange. It is preferably arranged on the non-exposed side. In this case, the presence of the gasket flange prevents the gasket from coming into contact with the high-temperature exhaust gas flowing through the inside of the upstream pipe, so that the above effect can be obtained more reliably.

Further, as described in claim 4, the upstream pipe may be an exhaust manifold collecting pipe. Generally, since the exhaust manifold collecting pipe is mounted near the engine, the exhaust gas flowing through the exhaust manifold has a considerably high temperature, and the gasket in the ball joint structure is likely to have a heat resistant temperature or higher. Therefore, when the exhaust pipe manifold collecting pipe is used as the upstream pipe of the present invention and the configuration of the present invention is adopted, the above effects can be more remarkably obtained.

One or both of the upstream pipe and the downstream pipe may be a double pipe. For example, when the upstream pipe has a double pipe, that is, an inner pipe and an outer pipe, a first flange is provided at the end of the outer pipe, and the end of the inner pipe is extended downstream to a position where it passes through the gasket. It may be configured as follows.

Further, one or both of the upstream pipe and the downstream pipe may be a flow passage dividing pipe in which a single pipe is divided into a plurality of flow passages by a partition plate.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the embodiment of the present invention
It is needless to say that the present invention is not limited to the following embodiments, and can take various forms within the technical scope of the present invention. [First Embodiment] FIG. 1 is a sectional view of a ball joint structure according to the first embodiment.

The ball joint structure of the first embodiment is a structure in which the upstream pipe 10 and the downstream pipe 20 are connected by the bolt 4 via the first flange 13, the gasket 8 and the second flange 23. The upstream pipe 10 is a single pipe and has a large diameter portion 10a and a small diameter portion 10b. The small diameter portion 10b is formed by necking the downstream end of the upstream pipe 10. A first flange 13 having a bolt insertion hole 13a is provided on the outer peripheral surface of the large diameter portion 10a of the upstream pipe 10. A gasket flange 9 having a substantially L-shaped cross section is fixed to the first flange 13. The gasket flange 9 is formed so as to extend at a distance (that is, in a non-contact state) from the large diameter portion 10a and the small diameter portion 10b of the upstream pipe 10 and along the axial direction of the upstream pipe 10. ing.

The downstream pipe 20 is a single pipe and is formed so that its inner diameter is larger than the outer diameter of the small diameter portion 10b of the upstream pipe 10. The second outer peripheral surface of the upstream end of the downstream pipe 20 has a bolt insertion hole 23a.
A flange 23 is provided. This second flange 23
Has a sliding surface 23b capable of contacting a substantially hemispherical surface 8b of the gasket 8 described later.

The gasket 8 is formed in a substantially donut shape. The gasket 8 is a gasket flange 9
Of the first pipe on the side not facing the upstream pipe 10 and
It is arranged between the flange 13 and the second flange 23. The contact surface of the gasket 8 with the second flange 23 is formed as a substantially hemispherical surface 8b. The small-diameter portion 10b, which is the downstream end of the upstream pipe 10, extends in the downstream direction up to the position where it passes through the gasket 8.

The bolt 4 is inserted into the bolt insertion hole 23a from the second flange 23 side through the spring 2, further inserted into the bolt insertion hole 13a of the first flange 13, and then fastened to the nut 6. A spring retainer 4a is attached to the bolt 4.
The spring 2 is arranged between the spring retainer 4 a and the second flange 23.

Next, the function of the ball joint structure of the first embodiment will be described. In the ball joint structure of this embodiment, the downstream pipe 2 is attached to the substantially hemispherical surface 8b of the gasket 8.
Since the sliding surface 23b of the second flange 23 of No. 0 slidably contacts and the spring 2 is arranged between the spring retainer 4a and the second flange 23, the vertical direction of the vehicle shown in FIG. Displacement in all directions of the direction D1, the left-right direction D2, and the front-rear direction D3 prevents the vibration of each direction of the upstream pipe 10 from being transmitted to the downstream pipe 20.

Here, the gasket 8 is the upstream pipe 1
Since it is not in contact with 0 or the downstream pipe 20, even if the temperature of each pipe 10, 20 is increased by the high temperature exhaust gas flowing through each pipe 10, 20, the heat does not directly reach the gasket 8. . Therefore, the gasket 8 can be constantly maintained at the heat resistant temperature or lower, and the effect of improving the durability can be obtained.

The small-diameter portion 10b, which is the end portion on the downstream side of the upstream pipe 10, extends in the downstream direction to a position where it passes through the gasket 8. That is, the gasket 8
Is covered with the small-diameter portion 10b, it does not come into direct contact with the high-temperature exhaust gas flowing through the inside of the upstream pipe 10. Therefore, it is possible to more reliably eliminate the risk that the gasket 8 is heated to the heat resistant temperature or higher by the high temperature exhaust gas flowing through the inside of the upstream pipe 10, and it is possible to obtain the above effect more reliably.

Further, the first flange 13 is provided with a gasket flange 9 surrounding the upstream pipe 10 with a gap, and the gasket 8 is arranged on the side of the gasket flange 9 that does not face the upstream pipe 10. .
Therefore, the presence of the gasket flange 9 prevents the gasket 8 from coming into contact with the high-temperature exhaust gas flowing through the inside of the upstream pipe 10, so that the above effect can be more reliably obtained. [Second Embodiment] FIG. 2 is a sectional view of a ball joint structure according to a second embodiment.

The ball joint structure of the second embodiment is the same as the first embodiment except that the gasket flange 9 is not provided.
Since it is similar to the embodiment, the same components are designated by the same reference numerals and the description thereof is omitted. In the second embodiment, the gasket 8 is arranged between the first flange 13 and the second flange 23 in a non-contact state with the large diameter portion 10a and the small diameter portion 10b of the upstream pipe 10.

According to the ball joint structure of the second embodiment, as in the first embodiment, the gasket flange 9 is used.
Although the gasket 8 does not cover the gasket 8, since the gasket 8 is not in contact with the upstream pipe 10 and the downstream pipe 20, the high temperature exhaust gas flowing through the pipes 10 and 20 causes the pipes 10 and 20 to have a high temperature. However, the heat does not reach the gasket 8 directly. Therefore, the gasket 8 can be constantly maintained at the heat resistant temperature or lower, and the effect of improving the durability can be obtained.

The small-diameter portion 10b, which is the end portion on the downstream side of the upstream pipe 10, extends in the downstream direction until it reaches the position where it passes through the gasket 8. Therefore, the upstream pipe 1
Gasket 8 due to high temperature exhaust gas flowing through the inside of
The risk of being heated above the heat resistant temperature can be eliminated more reliably, and the above effects can be obtained more reliably. [Third Embodiment] FIG. 3 is a perspective view of a ball joint structure of a third embodiment, and FIG. 4 is a sectional view of the same.

In the ball joint structure of the third embodiment, the cone 30 which is a collection pipe of the exhaust manifold EM as the upstream pipe, the downstream pipe 40, the first flange 33, the gasket 8 and the second flange 43 are provided. It is a structure that is connected by a bolt 4 via.

The exhaust manifold EM has an exhaust port side flange 35 and four branch pipes 36a, 36b, 36.
It is composed of c, 36d, and a cone 30. The exhaust port side flange 35 has an opening at a position corresponding to the exhaust port of the cylinder head of the engine (not shown). Four branch pipes 36a, 36b, 36c, 36d
The upstream end is fixed to each opening of the exhaust port side flange 35, and the downstream end is molded to have a cross section of about 1/4 circle.

The cone 30 has four branch pipes 36a and 36a.
b, 36c, 36d with a stepped gathering pipe having a large diameter portion 30a corresponding to the size when the downstream end portions are gathered and a small diameter portion 30b substantially matching the diameter of the downstream pipe 40. Is. The cone 30 is divided into two flow paths S11 and S12 by a first partition plate 31 provided inside. At the end of the first partition plate 31, the downstream pipe 4
A pair of plate-shaped pieces 32, 32 covering the second partition plate 41 of No. 0 are fixed (at this time, a wire mesh is arranged in the gap between the pair of plate-shaped pieces 32, 32 and the second partition plate 41). It may be configured to prevent collision noise). And the flow path S1
1, the downstream ends of the branch pipes 36b and 36c are connected, and the flow path S12 is connected to the downstream ends of the branch pipes 36a and 36d. The combination of the branch pipes 36b and 36c and the combination of the branch pipes 36a and 36d are combinations in which the exhaust gases do not easily interfere with each other.

On the outer peripheral surface of the small diameter portion 30b of the cone 30,
A first flange 33 having a bolt insertion hole 33a is provided. A gasket flange 39 having a substantially L-shaped cross section is fixed to the first flange 33. The gasket flange 39 has a small diameter portion 30b of the cone 30.
At a distance from (ie in non-contact with) and the cone 30
Is formed so as to extend along the axial direction of.

The downstream pipe 40 is formed to have a diameter substantially equal to that of the small diameter portion 30b of the cone 30. The downstream side pipe 40 includes a second partition plate 41 provided inside the single pipe.
Is divided into two flow paths S21 and S22. The flow paths S21 and S22 are connected so as to correspond to the flow paths S11 and S12, respectively. A second pipe having a bolt insertion hole 43a on the outer peripheral surface of the upstream end of the downstream pipe 40.
A flange 43 is provided. This second flange 43
Has a sliding surface 43b capable of contacting a substantially semi-spherical surface 38b of the gasket 38 described later.

The gasket 38 is formed in a substantially donut shape. This gasket 38 is on the side of the gasket flange 39 that does not face the cone 30, and
It is arranged between the flange 33 and the second flange 43. The contact surface of the gasket 38 with the second flange 43 is formed as a substantially hemispherical surface 38b. The small-diameter portion 30b, which is the downstream end of the cone 30, extends in the downstream direction up to a position where it passes through the gasket 38.

The bolt 4 is inserted from the side of the second flange 43 into the bolt insertion hole 43a via the spring 2, further inserted into the bolt insertion hole 33a of the first flange 33, and then fastened to the nut 6. A spring retainer 4a is attached to the bolt 4.
The spring 2 is disposed between the spring retainer 4 a and the second flange 43.

Next, the function of the ball joint structure of the third embodiment will be described. In the ball joint structure of the present embodiment, the sliding surface 43b of the second flange 43 of the downstream pipe 40 slidably contacts the substantially hemispherical surface 38b of the gasket 38, and the spring retainer 4a and the second flange 43 are connected. Since the spring 2 is provided therebetween, it is prevented from being displaced in all directions and transmitting the vibration of the cone 30 in each direction to the downstream pipe 40. Further, the exhaust gas flowing through the flow paths S11, S21 and the exhaust gas flowing through the flow paths S12, S22 are less likely to interfere with each other due to the presence of the first and second partition plates 31, 41, and the pair of plate-shaped pieces 32, Due to the presence of 32, there is very little risk that the two exhaust gases will interfere with each other through the connecting portions of the first and second partition plates 31, 41. Therefore, it is possible to prevent a reduction in engine output due to exhaust interference.

Since the gasket 38 is not in contact with the cone 30 or the downstream pipe 40, the cone 3
Even if the temperature of the cone 30 and the downstream pipe 40 is increased by the high temperature exhaust gas flowing through the inside of the zero pipe and the downstream pipe 40, the heat does not directly reach the gasket 38. Therefore, the gasket 38 can be constantly maintained at the heat resistant temperature or lower, and the durability is improved.

The small-diameter portion 30b, which is the downstream end of the cone 30, extends in the downstream direction to a position where it passes through the gasket 38. That is, since the gasket 38 is covered by the small diameter portion 30b, it does not come into direct contact with the high temperature exhaust gas flowing inside the cone 30. Therefore, it is possible to more reliably eliminate the risk that the gasket 38 is heated to the heat resistant temperature or higher by the high temperature exhaust gas flowing through the inside of the cone 30, and it is possible to more reliably obtain the above effect.

Further, the first flange 33 is provided with a gasket flange 39 surrounding the cone 30 with a gap, and the gasket 38 is arranged on the side of the gasket flange 39 not facing the cone 30. Therefore, the presence of the gasket flange 39 prevents the gasket 38 from coming into contact with the high-temperature exhaust gas flowing through the inside of the cone 30, so that the above effect can be more reliably obtained.

Furthermore, since the cone, which is a collective pipe of the exhaust manifold, is generally mounted near the engine, the exhaust gas flowing through it has a considerably high temperature, and the gasket in the ball joint structure has a heat resistance temperature or higher. There is a high possibility that Therefore, since the ball joint structure of the present embodiment is adopted in such a connecting portion, the above effect can be more remarkably obtained. [Fourth Embodiment] FIG. 5 is a sectional view of a ball joint structure according to a fourth embodiment.

The ball joint structure of the fourth embodiment is the same as that of the third embodiment except that the large diameter portion 30a of the cone 30 is provided with the first flange 33. Therefore, the same components are designated by the same reference numerals. Is attached and the description thereof is omitted. According to the ball joint structure of the fourth embodiment, in addition to the operational effects of the third embodiment, the following operational effects are also achieved. That is, the first flange 3 is attached to the large diameter portion 30a of the cone 30.
3 is provided, the portion of the cone 30 that is exposed from the first flange 33 in the upward direction can be made considerably shorter than in the third embodiment. That is, it is possible to shorten the distance between the branch pipes 36a to 36d butted at the connection point and the downstream pipe 40. As a result, even if the conventional ball joint is not adopted because the space in the vertical direction cannot be sufficiently secured due to the minimum ground clearance of the vehicle, the ball of the fourth embodiment can be adopted. If the joint structure is adopted, the effect that it can be sufficiently adopted can be obtained. [Fifth Embodiment] FIG. 6 is a sectional view of a ball joint structure according to a fifth embodiment.

The ball joint structure of the fifth embodiment is the same as the first embodiment except that the upstream and downstream pipes are double pipes.
Since it is similar to the embodiment, the same components are designated by the same reference numerals and the description thereof is omitted. Upstream pipe 50
Consists of an inner pipe 51 and an outer pipe 52,
Both pipes 51 and 52 are joined at the upstream end (not shown), and the ends of both pipes 51 and 52 at the downstream end are free ends that are independently displaceable in the pipe axial direction. Is formed as. A ring-shaped wire mesh 53 is interposed between the pipes 51 and 52. The wire mesh 53 is fixed to the inner pipe 51, and is not fixed to the outer pipe 52 but only in contact therewith.

The first flange 13 is provided on the outer peripheral surface of the outer pipe 52 of the upstream pipe 50. Further, the small diameter portion 51b of the inner pipe 51 of the upstream pipe 50 extends in the downstream direction up to the position where it passes through the gasket 8. The downstream pipe 60 is composed of an inner pipe 61 and an outer pipe 62. Both pipes 61 and 62 are joined at a downstream end (not shown), and both pipes 61 and 62 are joined at an upstream end. Each is formed as a free end so that it can be independently displaced in the pipe axial direction. A ring-shaped wire mesh 63 is interposed between the pipes 61 and 62. The wire mesh 63 is fixed to the inner pipe 61 and the outer pipe 62.
Is not fixed and is only in contact with. The inner diameter of the inner pipe 61 is formed to be larger than the outer diameter of the small diameter portion 51b of the inner pipe 51.

The second flange 23 is provided on the outer peripheral surface of the outer pipe 62 of the downstream pipe 60. According to the ball joint structure of the fifth embodiment, the same operational effect as that of the first embodiment is obtained.

Further, the upstream and downstream pipes 50, 60
Since both are double tubes, the heat insulation is high even in a cold state such as when the engine is started, and as a result, the exhaust gas flowing through the inside flows without being cooled so much.
Therefore, the catalytic action of the catalytic converter (not shown) provided on the downstream side of the ball joint structure can be effectively exerted from the time of engine start.

Further, since the high-temperature exhaust gas flows through the inner pipes 51, 61, the inner pipes 51, 61 are heated to a higher temperature than the outer pipes 52, 62 and undergo a large thermal expansion. For this reason, the inner pipes 51 and 61 slide with respect to the outer pipes 52 and 62, but at this time, the presence of the wire meshes 53 and 63 prevents collision noise (abnormal noise) from being generated. [Other Embodiments] In the third to fifth embodiments, the gasket flange may not be used as in the second embodiment.

Further, in the fourth embodiment, instead of fixing the pair of plate-shaped pieces 32, 32 to the end of the first partition plate 31, as shown in FIG. 7, the end of the first partition plate 31 is fixed. The curved piece 131 may be curved toward the flow path S11 side to form the curved portion 131, and the curved piece 132 that is curved toward the flow path S12 side may be fixed to the end portion of the first partition plate 31. In this case, since the exhaust gas flowing through the flow path S11 flows along the curved portion 131 and the exhaust gas flowing through the flow path S12 flows along the curved piece 132, the first partition plate 31 and the second partition plate 41 are formed. It is possible to obtain the effect that the exhaust gas flowing through the flow path S11 and the exhaust gas flowing through the flow path S12 hardly interfere with each other through the gap. Further, since the above effect can be effectively obtained by slightly bending the bending portion 131 and the bending piece 132, the bending portion 131 and the bending piece 132 are effective.
By providing the above, the cross-sectional areas of the flow paths S11 and S12 hardly change, and there is no fear that the back pressure increases. Further, since the bending portion 131 and the bending piece 132 do not have a structure that covers the end portion of the second partition plate 41, there is no risk of collision between them due to vibration or the like, and therefore there is no risk of collision noise.

Alternatively, in the fourth embodiment, the width (thickness) of the end of the first partition plate 31 may be made larger than that of the end of the second partition plate 41. For example, as shown in FIG. 8, the first partition plate 31 is bent toward the flow path S11 side to form a bent portion 231, and the plate material 232 is fixed to the flow path S12 side of the bent portion 231. The width (thickness) of the end of the plate 31 can be made larger than that of the end of the second partition plate 41. In this case, since the exhaust gas flowing through the flow path S11 flows along the thick end portion, the exhaust gas flowing through the flow path S11 and the flow path S12 through the gap between the first partition plate 31 and the second partition plate 41. It is possible to obtain the effect that the exhaust gas flowing through the pipe hardly interferes with the exhaust gas. Also, the first
Since the above effect can be effectively obtained by only slightly increasing the width of the end portion of the partition plate 31, the flow paths S11, S1.
The cross-sectional area of 2 hardly changes, and there is no fear of increasing back pressure. Further, since the first partition plate 31 does not cover the end portion of the second partition plate 41, there is no possibility that they will collide with each other due to vibration or the like, and therefore no collision noise will occur.

The structure of FIG. 7 or FIG. 8 can be adopted without being limited to the ball joint structure as long as the pipe having the first partition plate and the pipe having the second partition plate are connected to each other. The effect of can be obtained.

[Brief description of drawings]

FIG. 1 is a broken sectional view of a ball joint structure according to a first embodiment.

FIG. 2 is a broken sectional view of a ball joint structure according to a second embodiment.

FIG. 3 is a perspective view of a ball joint structure according to a third embodiment.

FIG. 4 is a broken sectional view of a ball joint structure according to a third embodiment.

FIG. 5 is a broken sectional view of a ball joint structure according to a fourth embodiment.

FIG. 6 is a broken sectional view of a ball joint structure of a fifth embodiment.

FIG. 7 is a fractured sectional view of a modified example of the fourth embodiment.

FIG. 8 is a partial cross-sectional view of another modification of the fourth embodiment.

FIG. 9 is a fracture cross-sectional view of a conventional ball joint structure.

[Explanation of symbols]

2 ... Spring, 4 ... Bolt, 8
... Gasket, 8b ... Approximately hemispherical surface,
9 ... Flange for gasket, 10 ... Upstream pipe, 10a ... Large diameter part, 10b ...
Small diameter part, 13 ... 1st flange, 20 ...
Downstream pipe 23, second flange

Claims (4)

[Claims] 1. A first flange provided at an end portion of an upstream pipe, a second flange provided at an end portion of a downstream pipe, and an arrangement between the first flange and the second flange. And a gasket whose contact surface with the second flange is a substantially hemispherical surface, and the first flange and the second flange so that the second flange can slide along the substantially hemispherical surface of the gasket. And a connector for connecting the gasket via the gasket, wherein the gasket is arranged in non-contact with the upstream pipe and the downstream pipe. 2. The ball joint structure according to claim 1, wherein an end portion of the upstream side pipe extends in a downstream direction to a position where the upstream pipe passes through the gasket. 3. The first flange is provided with a gasket flange surrounding the upstream pipe with a gap, and the gasket is arranged on a side of the gasket flange that does not face the upstream pipe. The ball joint structure according to claim 1 or 2. 4. The upstream pipe is a collective pipe of an exhaust manifold.
The ball joint structure according to any one of 1.