JPH0141856Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the mounting structure of a heat shield plate to an exhaust pipe.

An example of a conventional heat shield mounting structure will be explained based on FIGS. 1 to 4. As shown in FIG. 1, the heat shield plate 2 has a semicircular cross-sectional shape along the outer peripheral surface of the exhaust pipe 1, and is fitted into the exhaust pipe 1 with a clamp 3.
It is held in the exhaust pipe 1 by tightening both ends with a tightening bolt 4 and a nut 5. Therefore, as shown in FIG. 2, the heat shield plate 2 is attached to the exhaust pipe A.
- Part A (part to be tightened) has a semicircular cross-sectional shape,
Other parts (such as the B-B section) have a wide and large cross section. The cross section of the heat shield plate B--B shown in FIG. 2 when assembled with the exhaust pipe 1 is as shown in FIG. 3.

When fitting the heat shield plate 2 to the exhaust pipe 1 as shown in Figure 1, the heat shield plate 2 may not fit perfectly along the exhaust pipe 1 due to manufacturing variations between the two (see Figure 4). ). That is, for example, as shown in FIG. 4, when the radius of curvature of the cross section (semicircle) of the heat shield plate 2 is smaller than the radius of the cross section of the exhaust pipe 1, the clamp 3
Even if the exhaust pipe 1 is tightened, a gap 14 may remain and the exhaust pipe 1 may not completely line up with the outer circumferential surface of the exhaust pipe 1. In this state, when the exhaust pipe 1 is assembled to the engine (not shown) and the engine is operated, the exhaust pipe 1 is heated, and when the engine is stopped and the exhaust pipe 1 is cooled, the heat is shielded by repeating this heating. The plate 2 is deformed and comes to follow the exhaust pipe 1. In this case, the clamp 3 becomes loose, resulting in a decrease in the tightening force. This reduction in the clamping force of the clamp causes a backlash between the exhaust pipe 1 and the heat shield plate 2, causing problems such as abnormal noise.

The present invention was devised to solve the above-mentioned problems, and has a structure in which a heat shield plate is attached to the exhaust pipe by wrapping the outer circumference of the exhaust pipe with a clamp and fastening both ends of the clamp with fastening members. A first hole is provided at one end of the heat shield plate, a second hole is formed near the first hole at a distance along the outer circumferential direction of the exhaust pipe, and the first and second holes The heat shield plate is inserted between the first and second holes by the clamp and the exhaust pipe, and the other end of the heat shield plate is inserted between either end of the clamp. The gist is a heat shield mounting structure characterized in that it is mounted on one side.

According to the present invention, only the portion of the heat shield between the first and second holes comes into contact with the exhaust pipe, and since the contact area is small, the heat shield can be attached to the exhaust pipe with a light clamping force even at room temperature. You can follow it. Furthermore, even if the exhaust pipe is heated after the above-mentioned tightening, the portion pressed by the clamp of the heat shield plate (the portion between the first and second holes)
is small, so even if the portion is deformed due to heat, the clamping force of the clamp will not decrease. Therefore, since the clamp does not loosen, there is an effect that rattling or abnormal noise between the exhaust pipe and the heat shield plate does not occur.

The present invention will be explained below based on a first embodiment shown in FIGS. 5 to 7. 1 is an exhaust pipe, 6 is a heat shield plate, 7 is a clamp, and 6c is one end of the heat shield plate 6. 9a is a first hole provided at one end 6c, and 9b is a second hole provided near the hole 9a at a distance from the hole 9a along the circumferential direction, which is the outer circumferential direction of the exhaust pipe 1. It is a hole. The hole 9a is provided across the flange 6d of the heat shield plate 6, and the holes 9a and 9b have a width and length sufficient for the clamp 7 to pass through, and are shaped so that the clamp 7 can move smoothly. It's summery. As shown in FIG. 5, the clamp 7 is configured to come out of the heat shield plate 6 through the hole 9b and reenter the inside of the heat shield plate 6 through the hole 9a. 6a is a flange that is the other end of the heat shield plate 6, and 7a and 7b are flanges that correspond to both ends of the clamp 7. The tips of the flange 6a of the heat shield plate 6 and the flange 7a of the clamp 7 are fixed by welding 8. 4 and 10 are tightening bolts and nuts which are fastening members, 4 is removable and the nut 10 is fixed to the flange 7a by welding. Clamp 7 connects tightening bolt 4 with nut 1
By screwing together the flanges 7a and 7b
is formed so as to approach and wrap around the exhaust pipe 1. 7b' is a bent end portion of the flange 7b of the clamp 7, which abuts against the flange 7a on the other side of the clamp 7 when the tightening bolt 4 is screwed into the nut 10. The configuration is such that the approximate tightness of the tightening bolt 4 can be determined by abutting against each other, and deformation of the exhaust pipe 1 due to over-tightening of the tightening bolt 4 can be prevented. Also 6
d' is a bent portion at the tip of the flange 6d of the heat shield plate 6, and is intended to maintain the strength of the area around the hole 9a. 11 is a space between the clamp 7 and the heat shield plate 6. When the flange 7b of the clamp 7 is opened wide relative to the flange 7a in order to fit the exhaust pipe 1 into the clamp 7, the clamp 7 is inserted into the heat shield plate 6.
Although the exhaust pipe 1 approaches the bottom wall 6b of the heat shield plate 6, the dimensions of the heat shield plate 6 are configured such that the exhaust pipe 1 can be fitted into the bottom wall 6b without strongly pressing the bottom wall 6b.

Fit the exhaust pipe 1 into the clamp 7, and then tighten the clamp 7.
When the flange 7b is brought closer to the flange 7a and the tightening bolt 4 is screwed into the nut 10, the clamp 7 is closed.
follows around the exhaust pipe 1. When the clamp 7 is further tightened, the portion 7c of the clamp 7 can strongly press the portion between the holes 9a and 9b of the heat shield plate 6 against the exhaust pipe 1, so that the portion 7c of the clamp 7 can be forced along the exhaust pipe 1. Thus, the portion between the holes 9a and 9b of the heat shield plate 6 is held between the clamp 7 and the exhaust pipe 1, and the flange 6 of the heat shield plate 6
a is held on the exhaust pipe 1 via the welded part 8 and the clamp 7, so the heat shield plate 6 is attached to the exhaust pipe 1 at two places.
will be supported by Note that the seventh
Although the hole 9a, 9b shown in the figure is located only at one location in the longitudinal direction of the exhaust pipe 1 (in the direction of the arrow in FIG. 7), they may be provided as appropriate.

According to the first embodiment, the heat shield plate 6 has holes 9a,
Since it contacts the exhaust pipe 1 only at the narrow part between the bolts 9b, it is possible to make the bolt 4 sufficiently follow the exhaust pipe 1 at room temperature without increasing the tightening torque of the tightening bolt 4. Furthermore, even if the exhaust pipe 1 is heated during operation after assembly into the engine, the portion between the holes 9a and 9b of the heat shield plate 6 is narrow, so even if this portion is deformed by heat, the clamp 7 will remain loose. First, the problem that the clamping force of the clamp 7 decreases does not occur. Therefore, there is no play between the heat shield plate 6 and the exhaust pipe 1, and no abnormal noise is generated.

Further, as shown in FIG. 2, the conventional heat shield plate 2 has a weak strength because the A-A section, which is the clamp attachment section, is thinner and has a smaller section modulus than the other sections. In this case, it was necessary to increase the strength by reinforcing the A-A section or increasing the thickness of the entire heat shield plate, which resulted in disadvantages in terms of cost and weight. On the other hand, in the first embodiment of the present invention,
As shown in FIG. 7, the cross section of the heat shield plate 6 including the clamp attachment portions (fastened portions) 9a and 9b has the same shape as the cross section of the other portions and is unchanged. Therefore, since the clamp attachment part does not become a strength bottleneck, there is no need to provide special reinforcement to the clamp attachment part or to increase the thickness of the entire heat shield plate, which is effective in preventing increases in weight and cost.

Furthermore, in the conventional example shown in FIG. 1, the heat shield plate 2 and the exhaust pipe 1 are in close contact with each other at the clamp attachment part, so
Although the heat insulation effect is small, in the first embodiment, there is a space 1 between the exhaust pipe 1 and the heat shield plate 6, as shown in FIG.
1, the clamp mounting part has a large heat insulation effect.

The heat shield plate 12 of the second embodiment shown in FIG. 8 is a modification of the first embodiment described above, and the cross section of the C-C section, which is the clamp attachment part, is the same as that of FIG.
-D section has almost the same shape as that in FIG.
That is, in the second embodiment, only the clamp mounting portion C-C is moved closer to the exhaust pipe, and the other parts are further away from the exhaust pipe, so that the heat shielding effect is further increased. Although the holes 9a and 9b are shown at only one location in the longitudinal direction of the exhaust pipe 1 in FIG. 8, they may be provided as appropriate to serve as a clamp attachment portion.

The third embodiment shown in FIG. 9 has a flange 6a of the heat shield plate 6 and a flange 7a of the clamp 7 of the first embodiment.
Instead of welding the flange 13a of the heat shield plate 13,
is formed so that it overlaps the flange 7a of the clamp 7 and is fixed by tightening both the tightening bolt 4 and the nut 5. Therefore, the flange 13a of the heat shield plate 13 has approximately the same width as the flange 7a of the clamp 7, and is provided with a through hole (not shown) through which the tightening bolt 4 passes. Heat shield plate 1
3, the end opposite to the flange 13a has the same mounting structure as the first embodiment.

When attaching the third embodiment to the exhaust pipe 1, the clamp 7 is passed through the holes 9a and 9b of the heat shield plate 13, but the flange 7a of the clamp 7 and the heat shield plate 1
Since the flange 13a of the clamp 7 is not fixed before the tightening bolt 4 is installed, the flange 13a of the clamp 7
It is easy to widen the space between b and flange 7a. Therefore, the third embodiment has the effect that the exhaust pipe 1 can be easily fitted. Note that the present invention can be used in a structure for attaching a heat shield plate to an exhaust pipe of any heat source such as an engine.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the conventional heat shield mounting structure, Figure 2
The figure is a reduced perspective view of the heat shield plate in Figure 1, and Figure 3 is a perspective view of the heat shield plate in Figure 2.
An enlarged cross-sectional view showing the relationship between the heat shield plate and the exhaust pipe along the line B-B in the figure, FIG. 4 is a cross-sectional view corresponding to FIG. 1 in the case of poor installation in the heat shield mounting structure of FIG. 1, Figure 5 shows the first embodiment of the present invention.
6 is a view taken along the line of FIG. 5, FIG. 7 is a reduced perspective view of the heat shield plate of the first embodiment, and FIG. 8 is a 7th view of the second embodiment. FIG. 9 is a perspective view of a corresponding heat shield plate, and FIG.
It is a sectional view corresponding to the figure. 1... Exhaust pipe, 2, 6, 12, 13... Heat shield plate, 3, 7... Clamp, 4... Tightening bolt,
5,10...Natsuto, 9a...1st hole, 9b...
2nd hole.

Claims (1)

[Scope of utility model registration request] In a structure in which a heat shield plate is attached to the exhaust pipe by wrapping the outer circumference of the exhaust pipe with a clamp and fastening both ends of the clamp with a fastening member, a first hole is provided at one end of the heat shield plate, A second hole is provided near the first hole at a distance along the outer circumferential direction of the exhaust pipe.
A hole is formed, the clamp is inserted into the first and second holes, the heat shield plate is held between the first and second holes by the clamp and the exhaust pipe, and the heat shield plate is further inserted into the first and second holes. A heat shield mounting structure characterized in that a side end is attached to one of both ends of the clamp.