JP2002089258A - Flexible joint structure for exhaust pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact flexible joint structure for exhaust pipes with high degrees of freedom in piping of the exhaust pipes by eliminating displacement orientation when absorbing vibration of an exhaust pipe system of an automobile or the like by oscillatory displacement. SOLUTION: A sealing member having a spherical slidably contacting face slidably contacting a spherical bearing face is provided on a flange provided on an upstream exhaust pipe or a downstream exhaust pipe and having the spherical bearing face, and it is sandwiched by a flange provided on the corresponding upstream or downstream exhaust pipe. At least two connecting holes equally distributed in a circumferential direction are provided on the flange of one exhaust pipe and connecting holes of the same number of the connecting holes provided on the flange of the one exhaust pipe are provided on the flange of the other exhaust pipe. The flanges are mutually arranged so that the connection holes are alternately equally distributed on a circumference and they are locked by locking members at the connection holes via a leaf spring between the pair of flanges.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure of an exhaust pipe connected to an exhaust manifold or the like of an internal combustion engine when absorbing vibration of an exhaust pipe system caused by transmission of engine vibration while swingingly displacing. The present invention relates to a compact exhaust pipe flexible joint structure having no difference depending on a displacement direction.

[0002]

2. Description of the Related Art In order to prevent the vibration generated from an engine and the vibration generated from a road surface during traveling in an automobile or the like from being transmitted to a vehicle body and thereby deteriorating ride comfort, vibration of an exhaust system is changed by swing displacement. Absorbing spherical joints are widely used. When connecting the upstream exhaust pipe and the downstream exhaust pipe as shown in FIG. 6, a flange 102 having a concave spherical seat surface is attached to one exhaust pipe 101 by welding or the like, as shown in FIG.
Two connection holes 102 a are provided in this flange in the direction of 180 degrees on the circumference, and a flange 104 of the other exhaust pipe 103 is provided.
A corresponding connecting hole 104a is also provided, and a sealing member 105 which comes into sliding contact with the spherical surface is interposed therebetween. A bolt 107 spring-biased by a coil spring 106 is passed through the connecting hole of one flange, and a nut 108 and the like are passed through the other flange. Screwed. In such a joint structure, since the seal member is held by the elastic force of two coil springs arranged in the 180-degree direction, the tension applied to the seal member varies depending on the displacement direction of the exhaust pipe. Directionality occurs in the vibration absorption performance of the device. In particular, when large vibrations such as rolling and pitching occur in the engine, the effect is large, and in some cases, uneven wear may occur on the spherical sliding contact portion of the seal member, and furthermore, the cause of exhaust gas sealing failure. Sometimes it was. In addition, the projecting portion of the coil spring is large, which limits the degree of freedom of arrangement of the exhaust pipe.

[0003]

SUMMARY OF THE INVENTION The present invention eliminates the displacement directionality when absorbing the vibration of the exhaust pipe system of an automobile or the like by swinging displacement, and is a flexible exhaust pipe having a high degree of freedom in exhaust pipe piping. The purpose is to provide a joint structure.

[0004]

Means taken by the present invention to solve the above-mentioned problem is that an upstream exhaust pipe or an upstream exhaust pipe is connected in a structure in which an upstream exhaust pipe and a downstream exhaust pipe are connected via a spherical joint. A seal member having a spherical sliding contact surface that slides on the spherical seat surface is disposed on a flange having a spherical seat surface provided on the downstream exhaust pipe, and the seal member is sandwiched between the flanges provided on the corresponding upstream exhaust pipe or the downstream exhaust pipe. At least two or more connection holes are provided in the flange of one of the exhaust pipes at equal intervals in the circumferential direction, and the same number of connection holes as the connection holes provided in the flange of the one exhaust pipe are provided in the flange of the other exhaust pipe. Are provided so that these connecting holes are equally divided alternately on the circumference, and the flanges are arranged between the pair of flanges with a locking member at the connecting holes via a leaf spring. .

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a connection structure of an exhaust pipe according to the present invention. A flange 2 having a spherical seating surface is attached to the exhaust pipe 1 by welding or the like.
Are provided at every 120 degrees on the outer circumference of the exhaust pipe. On the other hand, a flange 4 is also attached to the exhaust pipe 3 by welding or the like, and three connection holes 4a are also provided in the flange at intervals of 120 degrees on the outer circumference of the exhaust pipe. The connecting holes are arranged alternately, and a seal member 5 having a spherical sliding contact surface between the pair of flanges is attached so that the spherical sliding contact surface is located at the spherical seating surface of the flange. Leaf spring 6 having connection hole 6a
Are caulked and connected to the corresponding connection holes through rivets 7.

As shown in FIG. 2, the leaf spring 6 includes a plurality of thin leaf springs (for example, 611, 612,
613), for example, three (6
1, 62, 63) to form a circular divided multi-layer type.

When the pair of flanges are connected in this manner, a bending elastic force is applied to the leaf spring as shown in FIG. 3, so that when the vibration of the engine or the like is absorbed by the spherical sliding surface, the displacement is absorbed. The difference in tension due to the direction is small and acts to stably absorb vibration.

In this embodiment, the number of connection holes provided on one flange is three, but two or more connection holes can be arbitrarily selected according to the diameter of the exhaust pipe and the intended vibration absorption level. . The leaf spring may be of an integral type in which thin circular leaf springs 601, 602 and 603 are superposed as shown in FIG. 4. In this case, when the leaf spring is connected to a flange, it becomes as shown in FIG. The connection method is not limited to rivet caulking, but may be any method such as bolts and nuts as long as the flange and the leaf spring can be stably fastened.

[0009]

According to the present invention, as compared with the conventional two-point restraint by a coil spring, a four-point
Since a multipoint constraint is established at points or more, and the bending elastic force of the leaf spring is used, the difference in tension in the displacement direction is reduced, and vibration absorption characteristics with less directivity can be obtained. In addition, a simple structure in which a leaf spring is provided between a pair of flanges allows a high degree of freedom in the arrangement of piping.

[Brief description of the drawings]

FIG. 1 shows an example of a connection structure of an exhaust pipe according to the present invention.

FIG. 2 shows a structural example of a leaf spring according to the present invention.

FIG. 3 is a side view showing a state in which a leaf spring is attached in the exhaust pipe connection structure according to the present invention.

FIG. 4 shows a structural example of an integral type leaf spring.

FIG. 5 shows a side view of the leaf spring when the integral type leaf spring is attached.

FIG. 6 shows an example of a conventional exhaust pipe connection structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upstream or downstream exhaust pipe 2 Flange having a spherical seat 2a Connection hole 3 Corresponding exhaust pipe 4 Flange 4a Connection hole 5 Seal member 6 Leaf spring 7 Rivet

Claims (1)

[Claims] In a connecting structure of an exhaust pipe in which an upstream exhaust pipe and a downstream exhaust pipe are connected via a spherical joint, a flange having a spherical seat surface provided on an upstream exhaust pipe or a downstream exhaust pipe has a spherical bearing surface. A seal member having a spherical sliding contact surface that slides is provided, and is sandwiched between flanges provided on the corresponding upstream exhaust pipe or downstream exhaust pipe, and at least two or more in the circumferential direction of one exhaust pipe flange. The connecting holes are provided separately, and the same number of connecting holes as the connecting holes provided on the flange of the one exhaust pipe are provided on the flange of the other exhaust pipe, and these connecting holes are equally divided on the circumference alternately. A flexible joint structure for an exhaust pipe, wherein a pair of flanges are disposed on each other, and the pair of flanges are locked by locking members at these connection holes via leaf springs.