JP3841393B2 - Flexible joint structure of exhaust pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust pipe connecting structure used by being connected to an exhaust manifold or the like of an internal combustion engine, and is compact with no difference depending on the direction of displacement when absorbing vibration while oscillating and displacing exhaust pipe system vibration caused by transmission of engine vibration. The present invention relates to a flexible joint structure for an exhaust pipe.
[0002]
[Prior art]
A spherical joint that absorbs vibrations of the exhaust system with swing displacement in order to prevent vibrations generated from the engine and vibrations generated from the road surface during traveling in a car or the like from being transmitted to the vehicle body and deteriorating riding comfort. Widely used.
As shown in FIG. 5 , when connecting the upstream exhaust pipe and the downstream exhaust pipe, a flange 102 having a concave spherical seating surface is attached to one exhaust pipe 101 by welding or the like, and this flange is connected to the flange. Two holes 102a are provided in the direction of 180 degrees on the circumference, and a connecting hole 104a corresponding to the flange 104 of the other exhaust pipe 103 is also provided. Through a bolt 107 which is spring-biased by a coil spring 106 and screwed to another flange with a nut 108 or the like. In such a joint structure, the seal member is held by the elastic force of the two coil springs arranged in the 180 degree direction, so the tension applied to the seal member differs depending on the displacement direction of the exhaust pipe. Directionality will occur in the vibration absorption performance. In particular, when the engine is subjected to large vibrations such as rolling and pitching, the effect is great, and in some cases there is a risk of uneven wear on the spherical sliding contact portion of the seal member. There was also a case.
Further, the projecting portion of the coil spring is large and restricts the degree of freedom in arranging the exhaust pipe.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a flexible joint structure of an exhaust pipe that eliminates the displacement directionality when absorbing vibration of an exhaust pipe system of an automobile or the like by swing displacement, and is compact and has a high degree of freedom of piping of the exhaust pipe.
[0004]
[Means for Solving the Problems]
Means taken by the present invention to solve the above problems is a ball seat surface provided on the upstream exhaust pipe or the downstream exhaust pipe in the exhaust pipe connection structure in which the upstream exhaust pipe and the downstream exhaust pipe are connected via a spherical joint. A seal member having a spherical sliding contact surface that is in sliding contact with the ball seat surface is disposed on the flange having a flange, and is sandwiched between flanges provided in the corresponding upstream exhaust pipe or downstream exhaust pipe, and is attached to the flange of one exhaust pipe. At least two connection holes are equally divided in the circumferential direction, and the same number of connection holes as the connection holes provided on the flange of the other exhaust pipe are provided on the flange of the other exhaust pipe. mutual flange to aliquoted alternately arranged on the circumference, between the pair of flanges, the bend leaf springs in a state where the elastic force loaded with these connecting holes engaged with the locking member.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an example of an exhaust pipe connection structure according to the present invention. A flange 2 having a spherical seat surface is attached to the exhaust pipe 1 (corresponding to 101 in FIG. 5) , not shown, by welding or the like, and this flange has three connecting holes 2a on the outer circumference of the exhaust pipe at 120 degrees. It is provided for each. On the other hand, the flange 4 is also attached to the exhaust pipe 3 by welding or the like, and three connection holes 4a are also provided in this flange on the outer circumference of the exhaust pipe every 120 degrees. The seal members 5 (corresponding to the seal member 101 in FIG. 5) having a spherical sliding contact surface between the pair of flanges are arranged so that the coupling holes are alternately arranged . It is attached so as to be positioned on the ball seat surface, and is stakingly connected and locked through rivets 7 to the corresponding connecting holes via leaf springs 6 having six connecting holes 6a.
[0006]
As shown in FIG. 2, the leaf spring 6 is formed by connecting, for example, three (61, 62, 63) superposed thin plate springs (for example, three pieces of 611, 612, 613). A circular divided multilayer type was adopted.
[0007]
When the pair of flanges are connected in this manner, the bending spring force is applied to the leaf spring as shown in FIG. 3R> 3, and the displacement direction when the vibration of the engine or the like is displaced and absorbed by the spherical sliding contact surface. The tension difference due to is small, and the vibration is stably absorbed.
[0008]
In the present embodiment, the number of connecting holes provided in one flange is three, but two or more can be arbitrarily selected according to the diameter of the exhaust pipe and the target vibration absorption level.
In addition, the leaf spring may be an integral type in which circular thin leaf springs 601, 602, and 603 are overlapped as shown in FIG. 3 , and in this case, the leaf spring is connected to the flange as shown in FIG .
The connecting method is not limited to rivet caulking, and any bolts, nuts, etc. can be used as long as the flange and the leaf spring can be stably fastened.
[0009]
【The invention's effect】
According to the present invention, compared to the conventional two-point restraint by the coil spring, a four-point or more multi-point restraint using the leaf spring is used, and the bending elastic force of the leaf spring is used, so the tension difference in the displacement direction The vibration absorption characteristics with less directionality can be obtained. Moreover, since the leaf spring is provided between the pair of flanges, the degree of freedom in arranging the pipes is high.
[Brief description of the drawings]
FIG. 1 shows an example of an exhaust pipe connection structure according to the present invention.
FIG. 2 shows a structure example of a leaf spring according to the present invention.
FIG. 3 shows an example of the structure of an integral type leaf spring.
FIG. 4 shows a side view of a coupling structure and a leaf spring when an integral type leaf spring is attached.
FIG. 5 shows a conventional exhaust pipe connection structure example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Upstream or downstream exhaust pipe 2 Flange 2a which has a spherical seat surface Connection hole 3 Corresponding exhaust pipe 4 Flange 4a Connection hole 5 Seal member 6 Leaf spring 7 Rivet

Claims (1)

In the coupling structure of the upstream exhaust pipe and the downstream exhaust pipe is connected through a spherical joint exhaust pipe, the spherical seat surface to the flange having a spherical bearing surface provided on the upstream exhaust pipe or downstream exhaust pipe in sliding contact spherical sliding A seal member having a contact surface is arranged, sandwiched by a flange provided in the corresponding upstream exhaust pipe or downstream exhaust pipe, and connected to the flange of one exhaust pipe by dividing it into at least two parts in the circumferential direction. Provide the same number of connecting holes as the connecting holes provided in the flange of the one exhaust pipe in the flange of the other exhaust pipe, and mutually connect the flanges so that these connecting holes are equally divided on the circumference. flexible joint structure of the exhaust pipe, characterized in that the place, between the pair of flanges, are to lock the leaf spring in a state in which the bending elasticity was loaded and with these connecting holes in the locking member.

Images