JPH0658294U - Spherical joint for pipe - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the sealing property at a low cost without increasing the weight with a simple structure and to prevent the generation of abnormal noise. [Structure] A seal bearing 30 is sandwiched between a flange 20 provided on the upstream side exhaust pipe 1 and a seal seat 25 provided on the downstream side exhaust pipe 2, and is connected by a pressing spring 36. A spherical contact portion is formed between the seal seat and the seal bearing, a ring-shaped space portion 33 is formed in the convex spherical surface portion 32 of the seal bearing, and a ring-shaped bead 28 protruding in the space portion is formed in the seal seat. There is. The space portion reduces the contact area of the spherical contact portion, increases the contact surface pressure, and improves the sealing performance even when the set force of the pressing spring is reduced. Further, the bead increases the rigidity of the seal seat, and prevents the generation of abnormal noise.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure of a pipe spherical joint used for connecting pipes such as an exhaust pipe of an automobile.

[0002]

[Prior art]

 As a conventional spherical joint for pipes of this type, there is one disclosed in Japanese Utility Model Laid-Open No. 59-163121 as shown in FIG. This is applied to the connecting portion of the exhaust pipes of an automobile, and the seal bearing 4 is supported by the flange 7 provided at the end of the upstream exhaust pipe 1 and the end of the downstream exhaust pipe 2 is supported. The seat is provided with a seat 9. The seal bear ring 4 is sandwiched between the flange 7 and the seal seat 9 so that the flange and the seal seat face each other, and the bolt 10 and the pressing spring 12 urge both members in the pressing direction.

The seal bearing 4 is in the shape of a truncated sphere, and its convex spherical surface portion 3 is supported toward the downstream exhaust pipe 2 side. The seal seat 9 has a concave portion corresponding to the convex spherical surface portion 3 of the seal bearing. A spherical surface portion 8 is provided. In the case of connecting to the exhaust pipe, the seal bearing 4 is made of a sintered material in which fibers are impregnated with graphite. The seal seat 9 is made thicker than the plate thickness of the upstream exhaust pipe 1 and the downstream exhaust pipe 2. As a result, even if there is a variation in the angle when connecting the upstream and downstream exhaust pipes, or if there is an angular variation due to engine or vehicle vibration during traveling, the concave spherical surface of the seal bearing 4 and the seal seat can be changed. 8 is to absorb this and to secure the sealing performance.

[0004]

[Problems to be solved by the device]

 However, in such a conventional spherical spherical joint for pipes, the convex spherical surface portion 3 of the seal bearing is simply formed as it is on the outer peripheral surface of the truncated spherical body, and the concave spherical surface portion 8 of the seal seat also conforms to the spherical surface of this convex spherical surface portion. Are formed into a continuous spherical surface, and both surfaces facing each other are surfaces to be in contact with each other. Therefore, there is a problem that the contact area of the spherical portion is large, and as a result, the contact surface pressure becomes low, and the risk of exhaust gas leakage from the spherical portion cannot be eliminated. Therefore, as a countermeasure against this leak, the pressing spring 12 used for pressing the flange 7 and the seal seat 9 is inevitably made large to increase the set force.

As a result, the cost of the pressure spring is increased, the bolts are also required to be increased, and the set force is increased, so that the flange for supporting the seal bearing and the seal on the other side are supported. This also causes an increase in weight and cost for increasing the strength of the seat. Further, the reason why the seal seat 9 has a large thickness is that it also serves as a measure against abnormal noise from the joint portion. That is, when the contact portion has friction due to vibration, if the contact portion, that is, the concave spherical surface portion 8 of the seal seat has low rigidity, abnormal noise is generated. It is necessary.

Similarly, as a countermeasure against abnormal noise, it is possible to further reduce friction by performing Teflon processing on the seal bearing 4, which also leads to an increase in cost as described above. Therefore, in view of the above-mentioned conventional problems, an object of the present invention is to provide a pipe spherical joint which is simple in structure and does not increase the weight, and can improve the sealing performance and eliminate the abnormal noise at low cost. .

[0007]

[Means for Solving the Problems]

 Therefore, according to the present invention, a flange is provided on one of the first tube body and the second tube body whose ends are opposed to each other, and a seal seat is provided on the other, and a spherical surface is provided between the seal seat and the seal seat. In a spherical joint in which first and second pipe bodies are connected by a pressing means so as to be able to move relative to each other with a seal bearing having a contact surface sandwiched therebetween, a space portion is formed in a spherical contact surface of a seal bearing and a seal seat is formed. It was assumed that the bead formed in the space was formed to project into the space.

[0008]

[Action]

 Since the first tube and the second tube are connected so as to be able to move relative to each other with the seal bearing having the spherical contact surface sandwiched therebetween, even if there is variation or angular variation, this is absorbed and the seal state is maintained. It Further, since the space portion is formed on the spherical contact surface of the seal bearing, the contact surface pressure on the spherical contact surface is increased and the sealing performance is improved. Further, since the bead protruding into the space is formed in the seal seat, the rigidity of the seal seat is improved and the generation of abnormal noise is prevented.

[0009]

【Example】

 FIG. 1 is a sectional view showing an embodiment of the present invention applied to an exhaust pipe of an automobile. On the outer periphery of the end of the upstream exhaust pipe 1, a flange 20 having a cylindrical portion 21 that is press-molded is fixed by welding the end edge of the cylindrical portion 21. A tip 1a of the upstream exhaust pipe 1 projects from the flange 20 by a length substantially equal to the width of the seal bearing 30. A ring-shaped seal bearing 30 having a truncated spherical outer peripheral surface and a central through hole 31 is fitted into the projecting end portion of the upstream exhaust pipe 1 and is axially supported by the flange 20. There is.

A seal seat 25, which is press-molded and has a cylindrical portion 26, is welded and fixed to the outer periphery of the end of the downstream exhaust pipe 2 and having a cylindrical portion 26. A seal bearing 30 is sandwiched between the seal seat 25 and the flange 20 of the upstream side exhaust pipe 1 so that they face each other, and the seal seat 25 and the flange 20 are urged in the pressing direction by a bolt 35 and a pressing spring 36. I am trying. A predetermined gap is set between the tip 1a of the upstream side exhaust pipe and the tip 2a of the downstream side exhaust pipe in this urged state.

The seal bearing 30 has a convex spherical surface portion 32 supported toward the downstream exhaust pipe 2 side, and the seal seat 25 has a concave spherical surface portion 27 corresponding to the convex spherical surface portion 32 of the seal bearing. . In the case of connecting the exhaust pipe, the seal bearing 30 is formed of a sintered material in which fibers are impregnated with graphite.

The bolt 35 penetrates a hole 22 provided outside the outer diameter of the seal bearing 30 of the flange 20, and is fixed to the seal seat 25 by a nut 37. The pressing spring 36 is arranged in a compressed state between the washer 38 fitted on the head side of the bolt 35 and the flange 20. The hole 22 of the flange 20 has a diameter having a predetermined gap with respect to the bolt 35 passing therethrough. As a result, the upstream side exhaust pipe 1 and the downstream side exhaust pipe 2 are absorbed even if they are angularly displaced within a predetermined range, and the connected state is maintained in a pressed state with the seal bearing 30 interposed therebetween.

As shown in the front view of FIG. 2, the convex spherical surface portion 32 of the seal bearing 30 is formed with a ring-shaped space portion 33. On the concave spherical surface portion 27 of the seal seat 25, a bead 28 protruding toward the seal bearing 30 and accommodated in the space 33 is formed in a ring shape.

This embodiment is configured as described above, and since the ring-shaped space portion 33 is formed in the convex spherical surface portion 32 of the seal bearing, the convex spherical surface portion is divided into two parts 32 a and 32 b by the space portion 33. The contact area between the concave spherical surface portion 27 of the seal seat 25 and the convex spherical surface portion 32 of the seal bearing 30 is reduced. Therefore, the surface pressure between the seal bearing 30 and the seal seat 25 is increased, and the sealing performance is improved. Therefore, the set force of the pressing spring 36, which has been set high in order to increase the contact surface pressure in the past, can be lowered, and the wire diameter of the pressing spring 36 and the bolts 35 can be made small, resulting in weight and cost. Is reduced.

Further, since the set force can be similarly reduced, the wear of the seal bearing ring 30 is also reduced, and the required specifications are relaxed, so that there is an advantage that the Teflon processing or the like on the seal bearing is unnecessary. Further, the seal seat 25 has a ring-shaped bead 28 formed on the concave spherical surface portion 27, so that the rigidity thereof is increased. As a result, the generation of abnormal noise during friction is prevented, and the seal seat can be formed by press molding from a plate material, which is advantageous in that the processing is simple and the weight is reduced.

Although the upstream exhaust pipe is provided with a flange and the downstream exhaust pipe is provided with a seal seat in the embodiment, the present invention is not limited to this, and the flange is provided on the downstream exhaust pipe. A seal seat may be provided in the upstream exhaust pipe. Further, one of the exhaust pipes may be the exhaust manifold of the engine instead of the other exhaust pipes. Furthermore, the invention is not limited to the exhaust system of a vehicle, and can be easily applied to the connection of other pipes, and there is no limitation on the type of pipe. Further, although the space portion and the bead of the embodiment are ring-shaped and continuous, the present invention is not limited to this, and may be divided.

[0017]

[Effect of device]

 As described above, according to the present invention, since the space portion is formed on the spherical contact surface of the seal bearing of the spherical joint, the spherical contact surface is divided by the space portion and the contact area becomes smaller, so that the surface area between the seal bearing and the seal seat is reduced. The pressure increases. As a result, the set force of the pressing means can be reduced, the components of the pressing means can be downsized, and the weight and cost can be reduced, and the sealing performance can be improved. Since the seal seat that contacts the seal bearing is formed with a bead that protrudes into the above-mentioned space, its rigidity is increased, and even if it is formed by press molding from a thin plate material, generation of abnormal noise is prevented. However, this also has the effect of reducing weight and cost, and eliminating the need for expensive Teflon processing on the seal bearings.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a front view of the seal bearing in the embodiment.

FIG. 3 is a diagram showing a conventional example.

[Explanation of symbols]

 1 upstream side exhaust pipe 2 downstream side exhaust pipe 3 convex spherical surface part 4 seal bearing 7 flange 8 concave spherical surface part 9 seal seat 10 bolt 12 pressing spring 20 flange 21 cylindrical part 22 hole 25 seal seat 26 cylindrical part 27 concave spherical part 28 bead 30 seal bearing 31 center through hole 32 convex spherical surface portion 33 space portion 35 bolt 36 pressure spring 37 nut 38 washer

Claims (1)

[Scope of utility model registration request] 1. A flange is provided on one of a first tube body and a second tube body whose ends are opposed to each other, and a seal seat is provided on the other, and spherical contact is made between the seal seat and the seal seat. In a spherical joint in which the first and second tubular bodies are connected by a pressing means so as to be able to move relative to each other with a seal bearing having a surface interposed therebetween, a space is formed in the spherical contact surface of the seal bearing, and the space is formed in the seal seat. Is a pipe spherical joint characterized in that a bead protruding in the space is formed.