JP6718300B2 - Exhaust pipe joint structure - Google Patents

Description

The present invention relates to a joint structure of the exhaust pipe you mainly connected to the exhaust pipe together with one another in the exhaust path of an automobile.

In order to purify exhaust gas and reduce exhaust noise, various parts such as a catalyzer, a sub silencer, and a main silencer are provided side by side in the exhaust path from the engine of the automobile to the exhaust gas to reduce exhaust noise. If the entire parts made up of parts and exhaust pipes are welded and joined together, the product in the exhaust path will become large and bulky, and the amount that can be transported at one time during distribution will be small.If you want to replace only some parts However, the inconvenience arises that it is necessary to replace other than the necessary parts. Therefore, an exhaust pipe joint that connects the exhaust pipes to each other is used in the exhaust path.

An example of the existing exhaust pipe joint is the exhaust pipe joint 100 of FIG. The exhaust pipe joint 100 has a band 101 having a substantially Ω-shaped cross section, and tension heads 102 and 103 having a substantially inverted C-shaped cross section and a substantially C-shaped cross-sectional view are provided at both ends of the band 101, respectively. Female thread bodies 104 and 105 are installed on the tension heads 102 and 103 so as to be fitted inside. The male screw portion 106m of the bolt 106 is screwed into the female screw bodies 104 and 105, and the male screw portion 106m of the bolt 106 is provided so as to penetrate the tension head 102, the female screw body 104, the tension head 103, and the female screw body 105. A structure similar to the exhaust pipe joint 100 is disclosed in Patent Document 1.

When the exhaust pipe 201 and the exhaust pipe 202 are connected to each other by the exhaust pipe joint 100, the head 106n of the bolt 106 presses the female screw body 104 to tighten the bolt 106 for connection. However, in the connection by the exhaust pipe joint 100, there is a high possibility that the amount of exhaust gas leaks from the void 203m not covered with the band among the voids 203 exposed on the outer peripheral side of the exhaust pipe 201 and the exhaust pipe 202. .. This increase in the exhaust gas leakage amount causes the highly harmful exhaust gas to be directly emitted to the atmosphere, causes abnormal noise and noise, and causes the exhaust pressure to become lower than the set exhaust pressure, so an exhaust gas recirculation (EGR) device There is a problem in that the required exhaust cannot be turned to the intake side or the combustion gas in the piston is discharged at a high speed, which reduces the combustion efficiency of the engine and causes torque reduction.

As a structure capable of suppressing such an increase in exhaust gas leakage amount, there are gasket type joint structures of Patent Documents 2 and 3. This joint structure sandwiches a gasket so as to close the gap near the tips of the exhaust pipes that connect to each other, and clamps the clamp provided on the outer peripheral side so that the gaskets are pressed by the mutual exhaust pipes. By providing a gasket in a compressed state in the space between the pipes, it is possible to suppress the amount of exhaust gas leakage.

JP, 2014-173728, A Japanese Utility Model Publication No. 6-12713 JP, 2004-218660, A

However, the gasket-type joint structure described above requires the work of accurately sandwiching and assembling the gasket at a predetermined position using a gasket, resulting in high component cost and work cost, and inferior efficiency of manufacturing work. is there. Therefore, there is a demand for an exhaust pipe joint that can suppress the amount of exhaust gas leakage and can be efficiently manufactured at a low manufacturing cost.

The present invention is proposed in view of the above problems, and uses an exhaust pipe joint that can suppress the amount of exhaust gas leakage at a connecting portion of an exhaust pipe and can be efficiently manufactured at a low manufacturing cost. An object is to provide a joint structure for an exhaust pipe.

The exhaust pipe joint structure of the present invention includes a metal outer band having a substantially C-shape in a front view , a metal inner band fixed to the inner side of the outer band, and a first band provided at both ends of the outer band. A first inner band part and a second inner band part separated from each other, the one end surface of the first inner band part having a receiving part and a tightening member bridged over the second receiving part. And an end portion of the second inner band portion facing each other, and the first inner band portion is fixed to the band plate of the outer band on the side of the first receiving portion with respect to the opposite portion, 2 the inner band portion is fixed to the band plate of the outer band on the second receiving portion side from the facing portion, and the band plate portion of the outer band at the corresponding position of the facing portion is a bendable hinge portion, An exhaust pipe joint in which an open side of the outer band is covered with a continuous surface of the first inner band portion is used, and a joint structure of exhaust pipes for connecting exhaust pipes to each other is provided at a base of an end portion of the first exhaust pipe. The end portion of the first exhaust pipe and the end portion of the second exhaust pipe are arranged such that the rewound portion that is rewound outward from the tip of the second exhaust pipe abuts on the ridge protruding to the outer periphery. Are provided so as to be overlapped inside and outside, and the inner band of the exhaust pipe joint is configured so as to substantially cover the void exposed to the outer peripheral side at the overlapping portion of the inside and outside of the first exhaust pipe and the second exhaust pipe. It is characterized in that the outer band and the inner band are attached in a state in which the outer band and the inner band are provided and are biased inward by the tightening of the tightening member .
According to this, by covering the open side of the outer band with the continuous surface of the inner band, resistance pressure against exhaust gas outflow can be obtained at the open side of the outer band, and the amount of exhaust gas leakage can be suppressed at the connecting portion of the exhaust pipe. can do. Therefore, it is possible to maximize the functions of various parts of the exhaust path, to reliably purify highly harmful exhaust gas, to prevent the generation of abnormal noise and noise, and to secure the set exhaust pressure. The effect that the combustion efficiency of the engine is increased and the torque can be effectively drawn is obtained. In addition, since it is not necessary to accurately assemble the gasket in a predetermined position by using a gasket and to assemble it, only the tightening work of the exhaust pipe joint including the outer band and the inner band is required, so that the manufacturing cost can be reduced. , Can be manufactured efficiently. Also, bend the double band consisting of the outer band and the inner band so that it opens at the hinge part of the outer band and place it at the connecting point of the exhaust pipe, and further bend so that it closes at the hinge part to form the double band. By returning to the normal state and tightening the tightening member, it is possible to easily and accurately attach the exhaust pipe to the correct position. Further, since it is a hinge portion that bends the band plate of the outer band, a separate hinge tool is not required, and in this respect, it is possible to reduce the manufacturing cost and improve the efficiency of manufacturing work. Further, since the hinge portion is provided with the opposing portion of the inner band, the inner band itself does not need to be bent, and only the outer band needs to be bent, so that a smooth opening/closing operation can be performed. In addition, the end portion of the first exhaust pipe and the end portion of the second exhaust pipe are provided so as to overlap with the inside and outside, and a gap exposed on the outer peripheral side at the overlapping portion of the inside and outside of the first exhaust pipe and the second exhaust pipe. The inner band of the exhaust pipe joint so that the exhaust band leaks to the connecting point of the exhaust pipe by attaching the outer band and the inner band while being urged inward by tightening the tightening member. Exhaust pipe fittings can be attached to reliably control the amount.

In the exhaust pipe joint structure according to the present invention, a gap is provided at the facing portion where one end surface of the first inner band portion and one end surface of the second inner band portion are opposed to each other , and the outer band is substantially C in front view. It is characterized in that a uniform inner peripheral surface of a band plate having a substantially flat plate plate shape in a letter shape is arranged outside the gap .
According to this, it is possible to prevent a manufacturing error or the like in which the first inner band portion and the second inner band portion are too long to fit in the outer band by providing a gap at a position where the one end surfaces face each other, and the design and It is possible to improve the yield by widening the allowable range for manufacturing accuracy. Also, for example, even when the diameter of the exhaust pipe to which the exhaust pipe joint is attached is smaller than the set value, it is possible to tighten with the inner band, and the allowable range for the manufacturing error and accuracy of the diameter of the exhaust pipe to which the exhaust pipe joint is attached is set. Can be expanded.

In the exhaust pipe joint structure according to the present invention, another gap is provided at a facing portion where the other end surface of the first inner band portion and the other end surface of the second inner band portion are opposed to each other, and the outer band has a schematic front view. It is characterized in that a uniform inner peripheral surface of the band plate having a C-shape and a substantially flat plate plate shape is arranged outside the other gap .
According to this, by providing a gap between the facing portions of the one end surface and another gap between the facing portions of the other end surface, one end portion of the first inner band portion and the second inner band portion are closed when closing. It is possible to prevent the vehicle from riding on the vehicle or the state where the end surfaces of the first inner band portion and the second inner band portion collide with each other. Then, when this riding state or a bumping state occurs, it becomes impossible to close and evenly close the exhaust pipe to which the first inner band part and the second inner band part are attached, but it is not possible to tighten it. It is possible to prevent such a state from occurring in both of the gaps, and more surely suppress the amount of exhaust gas leakage at the connecting portion of the exhaust pipe. Further, in the case of a bumped state, stress concentrates on the bumped portion and there is a risk of damage or damage, but this damage or damage can also be prevented.

The exhaust pipe joint structure of the present invention is characterized in that the width of the hinge portion is narrower than the width of the portion of the band plate before and after the hinge portion.
According to this, it becomes possible to perform a smoother opening/closing operation by narrowing the width of the hinge portion.

The exhaust pipe joint structure of the present invention is characterized in that a through hole is formed in the hinge portion.
According to this, it is possible to perform a smoother opening/closing operation by forming the through hole in the hinge portion and narrowing the substantial width.

According to the present invention, it is possible to suppress the amount of leakage of exhaust gas at the connecting portion of the exhaust pipe, and to efficiently manufacture the exhaust pipe joint and the joint structure of the exhaust pipe at a low manufacturing cost.

(A) is a front view of the exhaust pipe joint of the first embodiment according to the present invention, (b) is a perspective view of the exhaust pipe joint of the first embodiment with a fastening member removed and opened, and (c) is a perspective view. The front view in the state where the fastening member was removed and opened from the exhaust pipe joint of one embodiment. (A) is a perspective view which shows the joint structure of the exhaust pipe of 1st Embodiment by this invention, (b) is the AA sectional drawing. (A) is a side view of the exhaust pipe joint according to the second embodiment of the present invention with the hinge portion facing forward, and (b) is a state in which the fastening member is removed from the exhaust pipe joint of the second embodiment and opened. Perspective view. (A) is a side view of the exhaust pipe joint according to the third embodiment of the present invention with the hinge portion facing forward, and (b) is a state in which the fastening member is removed from the exhaust pipe joint of the third embodiment and opened. Perspective view. Explanatory drawing which shows the outline of a leak test. (A) is a perspective view of the joint structure of the exhaust pipe by the exhaust pipe joint of a comparative example, (b) is a cross-sectional view thereof, (c) is a vertical sectional view thereof. The graph which shows the result of the leak test of an Example and a comparative example. (A) is a top view of the exhaust pipe joint of a prior art example, (b) is the II sectional view, (c) is a longitudinal cross-sectional view of the joint structure by the exhaust pipe joint of a prior art example.

[Exhaust Pipe Joint and Exhaust Pipe Joint Structure of First Embodiment]
As shown in FIGS. 1 and 2, the exhaust pipe joint 1 of the first embodiment according to the present invention is made of a metal outer band 2 having a substantially C-shape in a front view, and a metal outer band 2 fixed inside the outer band 2. It has an inner band 3. The outer band 2 is composed of a band plate 21 that is substantially C-shaped when viewed from the front and has a substantially flat plate shape, and a first receiving portion 22 and a second receiving portion 23 that are tension heads are provided at both ends thereof. The fastening member 4 is bridged between the first receiving portion 22 and the second receiving portion 23.

In this embodiment, the bolt 41, the nut 42, and the washers 43 and 44 constitute the tightening member 4, and the first receiving portion 22 and the second receiving portion 23 are formed with through holes 221 and 231 respectively. There is. The male screw portion 411 of the bolt 41 is provided so as to penetrate the washer 43, the through hole 221 of the first receiving portion 22, the through hole 231 of the second receiving portion 23, and the washer 44, and the nut 42 is provided at the tip of the male screw portion 411. Are screwed together.

The inner band 3 is composed of a first inner band portion 31 and a second inner band portion 32 which are separated from each other. Each of the first inner band portion 31 and the second inner band portion 32 is formed of a strip plate having a substantially mountain shape in a cross-sectional view and both widthwise end portions projecting outward, and has a substantially semicircular arc shape in a front view. Is becoming The first inner band portion 31 and the second inner band portion 32 are arranged inside the outer band 2 so as to form a substantially circular shape, and are fixed to the outer band 2 by being fixed by the fixing portion 5. .. It is possible to use fixing in any suitable manner for fixing by the fixing portion 5, for example, spot welding, laser welding, rivet joining, projection welding, seam welding, friction welding, brazing, soldering, MIG welding, TIG welding. Alternatively, it is preferable to use electron beam welding, and the fixing portion 5 can be provided continuously along the circumferential direction of the outer band 2, or can be provided intermittently in the shape of dots or lines.

A gap 61 is provided at an opposite position where one end surface 311 of the first inner band portion 31 and one end surface 321 of the second inner band portion 32 face each other, and the other end surface 312 of the first inner band portion 31 is formed. A gap 62 is provided at a facing portion that faces the other end surface 322 of the second inner band portion 32. Then, the first inner band portion 31 is fixed to the band plate 21 of the outer band 2 on the first receiving portion 22 side from the facing portions of the one end surfaces 311, 321 and, in the present embodiment, on the first receiving portion 22 side from the gap 61, The second inner band portion 32 is fixed to the band plate 21 of the outer band 2 on the second receiving portion 23 side with respect to the facing portions of the one end surfaces 311 and 321 and, in the present embodiment, on the second receiving portion 23 side with respect to the gap 61.

A portion of the band plate 21 of the outer band 2 at a corresponding position of the facing portions of the one end faces 311 and 321 and in the corresponding position of the gap 61 in the present embodiment is a bendable hinge portion 24, and the hinge portion 24 is plastically deformed. By being bent, the outer band 2 and the first inner band portion 31 and the second inner band portion 32 fixed to the inner side of the outer band 2 can be opened and closed. The hinge part 24 of the present embodiment has the same structure and the same width as the other parts of the band plate 21.

The first end surface 311 of the first inner band portion 31 and the first end surface 321 of the second inner band portion 32 are in contact with each other without the gap 61, and the first end surface 311 and the first end surface 321 are in contact with each other. A configuration in which the other end surface 312 of the inner band portion 31 and the other end surface 322 of the second inner band portion 32 face each other without providing a gap 62 at the opposite position, or the one end surface 311 and the other end surface 312 contact each other. Both the end surface 321, the other end surface 312, and the other end surface 322 may be in contact with each other. In addition, the gap 61 is provided when the gap 61 is provided at a position where the one end face 311 and the one end face 321 corresponding to the hinge portion 24 are opposed to each other, or the gap 62 is provided when the other end face 312 and the other end face 322 are provided. Is preferably 0.5 mm or more and 1.5 mm or less from the viewpoint of relaxing design accuracy and manufacturing accuracy and further suppressing exhaust leakage.

In the exhaust pipe joint 1 in which the outer band 2 and the first inner band part 31 and the second inner band part 32 fixed to the inner band are closed, the open side of the outer band 2 is covered with the continuous surface of the inner band 3. In this embodiment, the continuous surface of the first inner band portion 31 covers the open side of the outer band 2 on which the fastening member 4 is provided.

In the exhaust pipe joint structure formed by the exhaust pipe joint 1, as shown in FIG. 2, the end portion of the first exhaust pipe 11 forming the exhaust path and the second exhaust pipe 12 forming the exhaust path are formed. It is provided so that the ends overlap. In the illustrated example, a protrusion 111 protruding to the outer periphery is formed at the base of the end portion of the first exhaust pipe 11, and a rewinding portion 121 that is rewound outward is formed at the tip of the second exhaust pipe 12. Then, the end portion of the first exhaust pipe 11 and the end portion of the second exhaust pipe 12 are overlapped with each other so that the rewind portion 121 abuts on the protrusion 111.

The inner band 3 of the exhaust pipe joint 1 is arranged and provided so as to substantially cover the void 13 exposed to the outer peripheral side at the overlapping portion of the first exhaust pipe 11 and the second exhaust pipe 12, and this arrangement is provided. The outer band 2 and the inner band 3 are biased inwardly by tightening the tightening member 4 with and tightening the first receiving portion 22 and the second receiving portion 23 with the head 412 of the bolt 41 and the nut 42. 2 and the inner band 3 are attached in a state of being urged inward to form an exhaust pipe joint structure. With this structure, the exhaust pipe joint 1 can be attached to the connection portion of the exhaust pipes 11 and 12 so as to reliably suppress the amount of exhaust gas leakage.

According to the first embodiment, by covering the open side of the outer band 2 with the continuous surface of the inner band 3, a resistance pressure against exhaust gas outflow can be obtained on the open side of the outer band 2, and the exhaust pipes 11 and 12 have a resistance pressure. It is possible to suppress the amount of exhaust gas leakage at the connection point. Therefore, it is possible to maximize the functions of various parts of the exhaust path, to reliably purify highly harmful exhaust gas, to prevent the generation of abnormal noise and noise, and to secure the set exhaust pressure. The effect that the combustion efficiency of the engine is increased and the torque can be effectively drawn is obtained. Further, the work of accurately sandwiching the gasket at a predetermined position using a gasket and assembling it is unnecessary, and only the work of tightening the exhaust pipe joint 1 composed of the outer band 2 and the inner band 3 is required, so that the manufacturing cost can be reduced. In addition to being able to perform, it can be manufactured efficiently.

In addition, a double band composed of the outer band 2 and the inner band 3 is bent so as to open at the hinge portion 24 of the outer band 2 and is arranged at the connecting portion of the exhaust pipes 11 and 12, and further closed at the hinge portion 24. By bending the double band to the normal state and tightening the tightening member 4, the double band can be easily and accurately attached to the connecting position of the exhaust pipes 11 and 12. Further, since it is the hinge portion 24 that bends the band plate 21 of the outer band 2, a separate hinge tool is not required, and in this respect as well, the manufacturing cost can be reduced and the manufacturing work efficiency can be improved. Further, since the hinge portion 24 is provided with a portion facing the inner band 3, the inner band 3 itself does not need to be bent and only the outer band 2 needs to be bent, so that a smooth opening/closing operation can be performed.

In addition, the gap 61 is provided at the location where the one end surface 311 of the first inner band portion 31 and the one end surface 321 of the second inner band portion 32 face each other, so that the first inner band portion 31 and the second inner band portion 32 are made longer. It is possible to prevent a manufacturing error or the like that does not enter the outer band 2 too much, widen the allowable range for the accuracy of design and manufacturing, and improve the yield. Further, for example, even when the diameters of the exhaust pipes 11 and 12 to which the exhaust pipe joint 1 is attached are smaller than a set value, it is possible to tighten with the inner band 3, and the diameters of the exhaust pipes 11 and 12 to which the exhaust pipe joint 1 is attached. It is possible to widen the tolerance range for manufacturing error and accuracy.

Further, in the present embodiment, by providing both the gap 61 at the location where the one end surfaces 311 and 321 face each other and the gap 62 at the location where the other end surfaces 312 and 322 face each other, the first inner band portion 31 and It is possible to prevent a situation where one end of the second inner band portion 32 rides on the other, or a situation where the end surfaces of the first inner band portion 31 and the second inner band portion 32 collide with each other. When the vehicle is in the riding state or the bumping state, it is impossible to close and evenly close the exhaust pipes 11 and 12 to which the first inner band portion 31 and the second inner band portion 32 are attached in a substantially even manner. However, it is possible to prevent such a state from occurring in both of the gaps 61 and 62, and more reliably suppress the amount of exhaust gas leakage at the connecting portion of the exhaust pipes 11 and 12. Further, in the case of a bumped state, stress concentrates on the bumped portion and there is a risk of damage or damage, but this damage or damage can also be prevented.

[Exhaust Pipe Joint and Exhaust Pipe Joint Structure of Second Embodiment]
In the exhaust pipe joint 1a of the second embodiment according to the present invention, as shown in FIG. 3, the width of the hinge portion 24a of the band plate 21a of the outer band 2a is narrower than the width of the portions of the band plate 21a before and after that. In the illustrated example, the width is gradually narrowed toward the center of the hinge portion 24a, and the widths of the other band plates 21a are substantially the same. The other configurations of the exhaust pipe joint 1a and the configuration of the joint structure of the exhaust pipe are the same as those in the first embodiment.

According to the second embodiment, by narrowing the width of the hinge portion 24a, it is possible to perform a smoother opening/closing operation of the outer band 2a and the inner band 2. Furthermore, the corresponding effects can be obtained from the configuration corresponding to the first embodiment.

[Exhaust Pipe Joint and Exhaust Pipe Joint Structure of Third Embodiment]
As shown in FIG. 4, the exhaust pipe joint 1b according to the third embodiment of the present invention has a through hole 25b formed substantially in the center of the hinge portion 24b of the band plate 21b of the outer band 2b. Other configurations of the exhaust pipe joint 1b and a configuration of the exhaust pipe joint structure are the same as those in the first embodiment.

According to the third embodiment, by forming the through hole 25b in the hinge portion 24b and narrowing the substantial width, it is possible to perform a smoother opening/closing operation of the outer band 2b and the inner band 2. Furthermore, the corresponding effects can be obtained from the configuration corresponding to the first embodiment.

[Modifications of Embodiment, etc.]
In addition to the configurations of the inventions and the embodiments, the invention disclosed in the present specification specifies, in an applicable range, these partial configurations by changing to other configurations disclosed in the present specification, or The present invention includes those specified by adding other structures disclosed in the present specification to these structures, or a generalized model specified by deleting these partial structures within a range in which partial operational effects can be obtained. .. The following modifications are also included.

For example, the tightening member according to the present invention is not limited to the tightening member 4 including the bolt 41, the nut 42, and the washers 43 and 44, and may include the first receiving portion and the second receiving portion provided at both ends of the outer band. Any member can be used as long as it can be tightened so as to narrow the gap. Further, the material of the outer band 2 and the inner band 3 is appropriate as long as it is made of metal, and may be, for example, zinc, aluminum, stainless steel, titanium or the like or an alloy thereof, or various plated steel plates.

Further, the exhaust pipe constituting the joint structure of the exhaust pipe of the present invention is not limited to a substantially cylindrical shape in cross section, and may be, for example, an elliptical exhaust pipe in cross section, a substantially square shape in cross section, a substantially hexagonal shape in cross section. A substantially polygonal exhaust pipe or the like is suitable. Correspondingly, the substantially C-shaped front view of the outer band includes a shape that follows a substantially elliptical shape in cross section and a shape that follows a substantially polygonal shape in cross section. In the exhaust pipe joint of the present invention, various deformed pipes are included. It is possible to use an outer band and an inner band having a shape corresponding to the above shape.

[Leak test results in exhaust pipe joint structures of Examples and Comparative Examples]
Next, the results of the leak test performed on the joint structure of the exhaust pipe of the example and the joint structure of the exhaust pipe of the comparative example will be described. The joint structure of the exhaust pipe of the example is the same as the joint structure of the exhaust pipe of the first embodiment, and the inner band 3 of the exhaust pipe joint 1 of the first embodiment is connected to the first exhaust pipe 11 and the second exhaust pipe. The outer band 2 and the inner band 3 are urged inward by arranging so as to substantially cover the space 13 exposed on the outer peripheral side at the overlapping portion of 12 and tightening the tightening member 4.

Then, as shown in FIG. 5, lids 71 and 72 are welded and fixed to the outer end of the first exhaust pipe 11 and the outer end of the second exhaust pipe 12, and the air pipe 73 is introduced into the lid 72. Then, air is allowed to flow into the first exhaust pipe 11 and the second exhaust pipe 12 via the air pipe 73. A regulator 74 is provided in the middle of the air pipe 73 so that the pressure of the inflowing air can be adjusted. In the joint structure of the embodiment closed with the lids 71 and 72, the whole is submerged in the water 76 of the water tank 75, and above the position where the exhaust pipe joint 1 is provided, with the opening on the lower side, the graduated cylinder 77. Was established. In this state, air was introduced into the closed joint structure, and the amount of air leaked in 10 seconds was measured by the graduated cylinder 77. This leak test was performed by changing the pressure with the regulator 74.

Further, the exhaust pipe joint structure of the comparative example is configured by the exhaust pipe joint 300 of FIG. The exhaust pipe joint 300 has a band portion 301 formed of a band plate having a substantially C shape in a front view, a substantially mountain shape in a cross-sectional view, and both widthwise end portions projecting outward, and both ends of the band portion 301. It is assumed that the first receiving portion 302 and the second receiving portion 303 are provided in each. The bolt 304 is bridged over the first receiving portion 302 and the second receiving portion 303 so as to be inserted into the respective through holes, and the head of the bolt 304 is located outside the first receiving portion 302 and on the male screw portion of the bolt 304. The nut 305 to be screwed is arranged outside the second receiving portion 303.

In the exhaust pipe joint structure formed by the exhaust pipe joint 300 of the comparative example, the end portion of the first exhaust pipe 401 forming the exhaust path and the end portion of the second exhaust pipe 402 forming the exhaust path are overlapped. The protrusion 4011 that is provided in this way and is formed so as to project to the outer periphery at the base of the end portion of the first exhaust pipe 401, and the rewind portion 4021 that is formed by being rewound outward at the tip of the second exhaust pipe 4021. And abut. Then, the band portion 301 of the exhaust pipe joint 300 is disposed and provided so as to substantially cover the void 403 exposed on the outer peripheral side at the overlapping portion of the first exhaust pipe 401 and the second exhaust pipe 402. By tightening the bolt 304 and the nut 305, the joint structure of the exhaust pipe in which the substantially C-shaped band portion 301 is biased inward is configured.

Also in this comparative example, similarly to the example, a lid was welded and fixed to the outer end of the exhaust pipe 401 and the outer end of the exhaust pipe 402 to close the same, and air was introduced in the same manner as the example to perform a leak test. ..

The result of the leak test is shown in FIG. As is clear from FIG. 7, the amount of air leakage in the exhaust pipe joint structure of the embodiment is considerably smaller than that of the comparative example, and the higher the air pressure, the more noticeable the difference in the amount of air leakage. Therefore, it can be seen that the exhaust pipe joint structure of the embodiment has a much smaller amount of exhaust leakage than the comparative example, and the higher the exhaust pressure, the higher the effect of suppressing the exhaust leakage amount.

INDUSTRIAL APPLICABILITY The present invention can be used, for example, in connecting exhaust pipes to each other in an exhaust path of an automobile.

1, 1a, 1b... Exhaust pipe coupling 2, 2a, 2b... Outer band 21, 21a, 21b... Band plate 22... First receiving portion 221... Through hole 23... Second receiving portion 231... Through hole 24, 24a, 24b ...Hinge part 25b...Through hole 3...Inner band 31...First inner band part 311...One end surface 312...Other end surface 32...Second inner band part 321...One end surface 322...Other end surface 4...Tightening member 41...Bolt 411 ...Male screw part 412... Head 42... Nuts 43, 44... Washers 5... Fixing parts 61, 62... Gap 11... First exhaust pipe 111... Projection 12... Second exhaust pipe 121... Rewinding part 13... Void 71 , 72... Lid 73... Air tube 74... Regulator 75... Water tank 76... Water 77... Measuring cylinder 100... Exhaust pipe fitting 101... Bands 102, 103... Tension head 104, 105... Female screw body 106... Bolt 106m... Male screw part 106n... Heads 201, 202... Exhaust pipes 203, 203m... Air gap 300... Exhaust pipe joint 301... Band portion 302... First receiving portion 303... Second receiving portion 304... Bolt 305... Nut 401... First exhaust pipe 4011... Projection Article 402...Second exhaust pipe 4021...Rewinding portion 403...Void

Claims (5)

A metal outer band having a substantially C shape in a front view, a metal inner band fixed to the inner side of the outer band, and a first receiving portion and a second receiving portion provided at both ends of the outer band. And a tightening member
The inner band includes a first inner band portion and a second inner band portion that are separated from each other, and has an opposing portion where one end surface of the first inner band portion and one end surface of the second inner band portion face each other. The first inner band portion is fixed to the band plate of the outer band on the first receiving portion side with respect to the facing portion, and the second inner band portion has the outer portion on the second receiving portion side with respect to the facing portion. Fixed to the band plate of the band, a portion of the band plate of the outer band at the corresponding position of the facing portion is a bendable hinge portion,
Using an exhaust pipe joint in which the open side of the outer band is covered with a continuous surface of the first inner band portion,
An exhaust pipe joint structure for connecting exhaust pipes to each other,
An end of the first exhaust pipe is arranged such that a ridge projecting to the outer periphery at the root of the end of the first exhaust pipe is brought into contact with a rewinding part that is rewound to the outside at the tip of the second exhaust pipe. And an end portion of the second exhaust pipe are provided so as to overlap inside and outside,
The inner band of the exhaust pipe joint is provided so as to substantially cover the void exposed on the outer peripheral side at the inner and outer overlapping portions of the first exhaust pipe and the second exhaust pipe,
An exhaust pipe joint structure , wherein the outer band and the inner band are attached in a state of being urged inward by tightening of the tightening member . A gap is provided at the facing portion where one end surface of the first inner band portion and one end surface of the second inner band portion face each other ,
The exhaust pipe joint structure according to claim 1, wherein a uniform inner peripheral surface of a band plate, which is substantially C-shaped in a front view and has a substantially flat plate shape, is arranged outside the gap. .. Another gap is provided at a facing portion where the other end surface of the first inner band portion and the other end surface of the second inner band portion face each other ,
The exhaust pipe according to claim 2, wherein a uniform inner peripheral surface of the band plate, which is substantially C-shaped when viewed from the front and has a substantially flat plate shape, is arranged outside the other gap. Joint structure. The exhaust pipe joint structure according to claim 1 , wherein a width of the hinge portion is narrower than a width of a portion of the band plate before and after the hinge portion . The exhaust pipe joint structure according to claim 1, wherein a through hole is formed in the hinge portion .

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