JPH07286516A - Mounting structure of thermal insulation plate for exhaust pipe - Google Patents

Abstract

PURPOSE:To prevent loosening of a tightening band which attaches a thermal insulation plate to an exhaust pipe to prevent generation of abnormal sound by the repetition of expansion and shrinkage of the thermal insulation plate due to effect of heat so as to improve loading property of the thermal insulation plate for exhaust pipe on a vehicle, facilitate mounting of the plate, and reduce manufacturing cost and weight when compared with mounting by means of bolt and nut. CONSTITUTION:Tightening sections 13b, 14b which are in contact with an outer peripheral surface of an exhaust pipe 11 are formed integrally at an end of a thermal insulation plate 12 which covers an outer periphery of the exhaust pipe 11. Tongue pieces 13e, 14e are formed integrally at both ends in the peripheral direction of the tightening sections 13b, 14b. Extended portions 15a, 15b for winding are formed integrally at both ends of a tightening band 15. The tightening band 15 is wound on the outer periphery of the tightening sections 13b, 14b, and the tongue pieces 13e, 14e and the extended portions 15a, 15b are to wind and tighten them together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for attaching a heat shield plate to an exhaust pipe, and more particularly to a heat shield plate for covering the outer periphery of the exhaust pipe in an internal combustion engine to cut off heat radiation from the exhaust pipe. Relates to a structure for attaching an exhaust pipe.

[0002]

2. Description of the Related Art Conventionally, a heat shield plate for blocking heat radiation from the outer peripheral surface of an exhaust pipe is attached to an exhaust pipe of an internal combustion engine of an automobile or the like.

As a structure for mounting a heat shield plate on such an exhaust pipe, generally, as shown in FIG. 12, a heat shield plate 1 made of a thin metal plate is wound around the exhaust pipe 2 with a predetermined gap. At the same time, the end portion 1a of the heat shield plate 1 is wound around the outer peripheral surface of the exhaust pipe 2, the fastening band 3 is wound around the outer peripheral surface of the end portion 1a attached to the exhaust pipe 2, and the flanges 3a at both ends thereof are wound. ，
The heat shield plate 1 is attached to the exhaust pipe 2 by tightening 3b with the bolt 4 and the nut 5 (Japanese Utility Model Publication No. 63-32895).

However, in this conventional structure, the heat shield plate 1 repeatedly expands and contracts due to the influence of exhaust heat, so that the tightening position of the fastening band 3 shifts in the axial direction of the pipe and the clamping force is loosened. However, there is a problem that resonance occurs and abnormal noise occurs.

Therefore, as a mounting structure for solving this problem, a structure in which a heat shield plate is fixed to a fastening band fixed to an exhaust pipe has been proposed. For example, the fastening band is fixed to the exhaust pipe with bolts and nuts. Then, a structure in which a tongue piece is formed on the fixed fastening band and a heat shield plate is fixed to the tongue piece with bolts and nuts (Japanese Utility Model Publication No. 61-13698)
Alternatively, a structure in which a fastening band is wound around the exhaust pipe, the bent portions of the heat shield plate are overlapped with the bent portions at both ends of the fastening band, and the bent portions of these three members are simultaneously tightened with bolts and nuts. (Japanese Utility Model Laid-Open No. 2-40924) or a structure in which a bracket is fixed to a catalytic converter in an exhaust system, and a heat shield plate is fixedly supported on the bracket with bolts and nuts (Actual Japanese Utility Model Publication 3-4).
7423) has been proposed.

[0006]

In the above-mentioned conventional mounting structure, since the fixing parts for the bolts and nuts are required for all of them, the number of parts is increased and the number of mounting steps is increased, resulting in a high manufacturing cost. In addition, mounting workability is poor. Furthermore, due to the vibration of the vehicle running,
The looseness of the bolt and nut is also a concern.

In view of this, the present invention prevents the loosening of the clamping force of the heat shield plate without using bolts and nuts, and facilitates the attachment work as compared with the fastening of bolts and nuts. It is an object of the present invention to provide a structure for attaching a heat shield plate to an exhaust pipe, which can be reduced in number and can be mounted on a vehicle (space property).

[0008]

In order to solve the above-mentioned problems, the present invention provides the outer periphery of the exhaust pipe at the end of the heat shield plate (12) covering the outer periphery of the exhaust pipe (11) in the pipe axial direction. Tongue pieces (13e, 14e, 16a) which are integrally formed with the fastening portions (13b, 14b, 16) that come into contact with the surface, and which project radially toward both ends of the fastening portions (13b, 14b, 16) in the circumferential direction. ，
16b) are integrally formed, and the fastening portions (13b, 14b,
An endwise fastening band (15, 17) is wound around the outer periphery of 16), and an extension portion (15a, 15b, 17a, 15a, 15b, 17a) for fastening is provided at the circumferential end of the fastening band (15, 17). 17
b), forming the tongue pieces (13e, 14e, 16a, 1)
6b) and the extended portions (15a, 15b, 17a, 17b) are wound together and fixed in a superposed state, and the heat shield plate (12)
Is attached to the exhaust pipe (11).

[0009]

When the heat shield plate (12) expands and contracts in the tube axis direction due to the influence of heat, the fastening portions (13b, 14b, 1)
Similarly, 6) also expands and contracts. At this time, the fastening band (1
5, 17) are extended portions (15a, 15b, 17a,
17b) and the tongue pieces (13e, 14e, 16a, 16b) integrally formed on the fastening portions (13b, 14b, 16) are integrally fastened by winding, so that the fastening portions (13
b, 14b, 16) and move integrally. Therefore, the tightening part (13
b, 14b, 16) and the fastening band (15, 17) are not displaced from each other, and the fastening force of the fastening band (15, 17) is not loosened. Therefore, generation of abnormal noise due to loosening is prevented.

Further, the winding tightening portions (A, A ') are
The bolt and nut can be wound and tightened with a protrusion that is shorter than the protrusion of the flange, and the thickness of the wound portion (A, A ') is the thickness of the wound plate, so that the bolt and nut can be tightened. It becomes thinner than the protruding length of bolts and nuts. Therefore, the occupied portion of the winding tightening portion (A, A ′) is reduced, the mounting space on the vehicle is reduced as compared with the tightening of the bolt and the nut, and the clearance with other parts is easily secured.

[0011]

EXAMPLES Next, examples of the present invention shown in FIGS. 1 to 6 will be described. Reference numeral 11 is an exhaust pipe of the internal combustion engine. Reference numeral 12 denotes a cylindrical heat shield plate, which is divided into two in the circumferential direction of the exhaust pipe 11 and is formed in a hollow shape. Heat shield structure 14
Are joined together so as to cover the outer circumference of the exhaust pipe 11 to form a cylindrical heat shield plate 12.

The main body portions 13a and 14a of the heat shield plate 12 are formed to have a larger diameter than the outer diameter of the exhaust pipe 11 so that a heat shield gap is formed between the main body portions 13a and 14a and the outer peripheral surface of the exhaust pipe 11. Part 13
b and 14b are formed so as to have an inner diameter in close contact with the outer peripheral surface of the exhaust pipe 11, and the main body portion 13a and the fastening portion 13b are integrally bent, and the main body portion 14a and the fastening portion 14b are integrally bent. Has been done. In addition, the circumferential lengths of both fastening portions 13b and 14b are such that, when these fastening portions 13b and 14b are wound around the exhaust pipe 11 as shown in FIG. Has been formed.

Further, outward bent pieces 13d and 14d are formed at the circumferential ends of both main body portions 13a and 14a, and these are simply opposed to each other. As shown in FIGS. 3 and 4, a tongue piece 1 integrally formed with the fastening portions 13b and 14b at both ends of the fastening portions 13b and 14b in the circumferential direction.
3e and 14e are extended substantially radially from the ends 13c and 14c.

Reference numeral 15 denotes a fastening band, which is formed of a strip-shaped metal plate as shown in FIGS. 5 and 6, and has a length in the longitudinal direction which is the fastening portion wound around the outer circumference of the exhaust pipe 11. 13b,
The length is set such that the extended portions 15a and 15b that project in a substantially radial manner are formed at both ends of the outer peripheral portion 14b while being wound around the outer periphery of the outer peripheral portion 14b.

Incidentally, the tongue piece 13 of the fastening portions 13b and 14b.
e, 14e and the extending portions 15a, 15b of the fastening band 15
Is formed of a metal plate that is plastically deformed. Next is the exhaust pipe 1
The attachment of the heat shield plate 12 to 1 will be described.

First, the two heat shield plates 13 and 1 divided into two parts.
4 is located at a portion of the exhaust pipe 11 that shields heat, and is fitted so as to wrap the exhaust pipe 11, and the flange portions 13d and 14d of the main body portions 13a and 14a are close to each other.
In this combined state, the semi-circular fastening parts 13b and 1
4b is in a state substantially along the outer peripheral surface of the exhaust pipe 11, and both tongue pieces 13e and 14e are in a state of protruding in a radial direction substantially parallel to each other as shown in FIGS. 3 and 4.

Next, the fastening band 15 is attached to the extension portion 15 of the fastening band 15.
Tongue pieces 13e, 1 which are wound around the outer periphery of the fastening portions 13b, 14b at positions where a and 15b overlap with the tongue pieces 13e, 14e and whose extending portions 15a, 15b are radially projected.
Polymerize in parallel with the outer surface of 4e.

Next, the tongue pieces 13e, 14e and the extending portions 15a, 15b are wound in a superposed state as shown in FIGS. 1 and 2 (curling), and the wound portions A, A are wound. The tongue piece and the extended portion of ′ are fixed by plastic deformation. As a result, the fastening band 15 crimps the fastening portions 13b and 14b to the exhaust pipe 11,
The fastening portions 13b and 14b are the fastening band 15 and the exhaust pipe 11.
The heat shield plate 12 is fixedly supported on the exhaust pipe 11 by being sandwiched between them.

In this embodiment, two winding tightening portions A and A'are formed in the exhaust pipe 11 in the front and rear in the diametrical direction. 7 to 11 show a second embodiment of the present invention.

The second embodiment is an embodiment in which the present invention is applied to a type in which the heat shield plate 12 is formed of a single plate without being divided into two in the circumferential direction. Therefore, as shown in FIGS. 7 to 9, the fastening portion of the heat shield plate 12 in the second embodiment has a shape in which one end in the circumferential direction is released, and the tongue pieces 16a and 16b are provided at both ends on the release side. The fastening portion 16 is formed, and the fastening band has a shape in which one end in the circumferential direction is released as shown in FIGS. 7, 10, and 11, and the extension portions 17a and 17b are provided at both ends on the release side. The tightening band 17 is formed with.

The heat shield plate 12 is attached by winding the fastening portion 16 around the exhaust pipe 11, winding a fastening band 17 around the outer peripheral surface of the fastening portion 16, and overlapping the fastening portion 16. 16 tongues 16a and 16b and extension portions 17a and 1 of the fastening band 17
7b and the winding tightening (curling) process as shown in FIG. 7, and the winding tightened state is fixed by the plastic deformation of the tongue piece and the extended portion of the winding tightened portion A. As a result, the heat shield plate 12 is fixedly supported by the exhaust pipe 11. In the second embodiment, there is only one winding tightening portion A.

Also in the second embodiment, the heat shield plate can be attached without using bolts and nuts,
The same action and effect as those of the above-mentioned embodiment are exhibited. The above-mentioned embodiments are examples in which the heat shield plate is applied to the type that covers the entire circumference of the exhaust pipe, but the heat shield plate is a type that covers only the upper half surface or the lower half surface of the exhaust pipe. It is also possible to apply the present invention to. In this case, the heat shield plate structure 13a on the upper side or the lower side of the heat shield plate 12 in the first embodiment.
Alternatively, the heat shield plate is fixedly supported to the exhaust pipe by using only 14a and tightening the fastening band as shown in FIGS. 5 and 6 in the same manner as in FIGS. 1 and 2. . In this case, there are two winding tightening portions A and A '. Alternatively, the tongue piece may be provided only on the front side and the fastening band 17 shown in FIGS. 10 and 11 may be used to provide only one winding fastening portion A. Also in these examples, the same actions and effects as above can be exhibited.

[0023]

As described above, according to the present invention, even if the heat shield plate repeatedly expands and contracts due to the influence of heat, the tightening force of the fastening band for tightening and fixing the heat shield plate to the exhaust pipe does not loosen. It is possible to prevent abnormal noise due to loosening.

Moreover, as compared with the conventional fixing of bolts and nuts, the occupying portion of the winding tightening portion is reduced and the mountability on the vehicle is improved. Further, since the fixing is performed by a simple winding process, the fixing work is easy, and the number of parts is smaller and the manufacturing cost can be reduced and the weight can be reduced as compared with fixing the bolt and the nut.

[Brief description of drawings]

1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a perspective view and FIG. 1B is an enlarged end view of a winding tightening portion.

FIG. 2 is a right end view of FIG.

FIG. 3 is an end face of a fastening portion of the heat shield plate.

FIG. 4 is a plan view of a tightening portion of the heat shield plate.

FIG. 5 is an end view of the fastening band.

FIG. 6 is a plan view of the fastening band.

FIG. 7 is an end view showing a second embodiment of the present invention.

FIG. 8 is an end view of a fastening portion of the heat shield plate.

FIG. 9 is a plan view of the heat shield plate.

FIG. 10 is an end view of the fastening band.

FIG. 11 is a plan view of the fastening band.

FIG. 12 is a perspective view of a conventional structure.

[Explanation of symbols]

11 ... Exhaust pipe 12 ... Heat shield plate 13, 14 ... Heat shield plate structure 13b, 14b, 16 ... Fastening part 13c, 14c,
16a, 16b ... Tongue piece 15, 17 ... Fastening band 15
a, 15b, 17a, 17b ... Extension part A ... Winding tightening part

Claims (1)

[Claims] 1. A fastening portion that abuts an outer peripheral surface of an exhaust pipe is integrally formed at an end portion of a heat shield plate that covers the outer periphery of the exhaust pipe in the pipe axial direction, and both end portions in the circumferential direction of the fastening portion. A tongue protruding in the radial direction is integrally formed with the end portion, and an end-shaped fastening band is wound around the outer periphery of the fastening portion, and an extension portion for winding fastening is formed at the circumferential end of the fastening band. An exhaust pipe heat shield plate mounting structure, characterized in that the tongue piece and the extension portion are wound together and fixed together in a superposed state so that the heat shield plate is attached to the exhaust pipe.