JPH11107772A - Heat insulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve thermal insulating properties, sound insulation and acoustic absorption properties to a great extent for an heat insulator covering thermal insulation-wise a high temperature equipment part such as an engine exhaust manifold and the like, and facilitate the manufacture of the insulator. SOLUTION: This insulator is formed out of two layers of insulator elements 2 and 3 faced to each other almost in parallel, and of each void 4 between the respective insulator elements, and at least one layer out of the insulator elements is formed out of two layers of metallic plates 21 and 22 where a thermal insulating sound absorbing layer 23 is held in between. The two layers of insulator elements 2 and 3 molded in a cover shape each, are held almost in parallel in such a way that a void is formed in between by means of spacers 5 and 6 dispersively disposed, and they are thereby combined with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulator for heat-shielding high-temperature equipment such as an exhaust manifold of an engine, a turbocharger, and an exhaust manifold connecting pipe of a V-type engine.

[0002]

2. Description of the Related Art As an example of the above-mentioned heat insulator, FIG. 9 shows an exhaust manifold 100 of an engine.
FIG. 2 shows a perspective view of a heat insulator 101 which is a cover that covers the heat insulator. The heat insulator 101 is attached to the exhaust manifold by an appropriate number of bolts 102, and is attached so as to leave a gap at an appropriate interval between the exhaust manifold and the main body of the heat insulator. In FIG. 9, only one mounting bolt 102 is shown, and the other mounting bolts are not shown.

[0003] The above-mentioned heat insulator is required to have a performance of insulating and covering a high-temperature portion such as an exhaust manifold and at the same time having a performance of insulating a noise of an engine or the like. One or two laminated sheets, sandwiched between a heat insulating sound absorbing material such as glass wool, ceramic fiber sheet, mica sheet or a composite of them between steel plate or stainless steel plate And those formed by attaching a heat insulating sound absorbing material to a steel plate or a stainless steel plate so as to be pressed by a wire mesh, and the like.

A heat insulator of the type described above is inferior in heat insulation, sound insulation and sound absorption, and may amplify noise due to resonance if poorly performed. Further, the heat insulation, sound insulation and sound absorption of the above-mentioned type of heat insulator are better than the above-mentioned type of heat insulator, but are still insufficient, and the thickness of the sound absorbing material layer is also 2 to 6 mm.
And need to be thicker. The above-mentioned type of heat insulator is intended to improve the sound absorbing property, but the manufacturing effect is troublesome, but the improvement effect is poor, and the sound absorbing material is damaged or scattered during long-term use. And the performance may be impaired.

[0005]

As described above, conventional heat insulators are not yet satisfactory in heat insulation, sound insulation and sound absorption. SUMMARY OF THE INVENTION An object of the present invention is to provide a heat insulator whose heat insulation, sound insulation and sound absorption are greatly improved, and which are relatively easy to manufacture.

[0006]

A heat insulator according to the present invention, which achieves the above object, is a cover for heat-shielding a high-temperature device such as an exhaust manifold of an engine. An insulator element and a substantially constant gap formed between the insulator elements, and at least one layer of the insulator element is formed by a two-layer metal plate having a heat insulating sound absorbing material layer interposed therebetween. It is characterized by having.

[0007] Further, the heat insulator of the present invention comprises:
The two-layered insulator element molded in the shape of a cover is sandwiched and connected so as to be substantially parallel to each other by spacers arranged in a distributed manner, and the spacer forms a spacer portion for forming a gap. It is made up of eyelets provided.

[0008] In the heat insulator of the present invention, as described above, there are substantially constant gaps between the two layers of insulator elements, and at least one of the insulator elements has a heat insulating sound absorbing material in between. , The heat insulation, sound insulation, and sound absorption are greatly improved by the air layer in the gap and the heat insulating sound absorbing material.

Further, the heat insulator of the present invention comprises:
Since the two-layered insulator element molded in the shape of the cover is sandwiched and connected by the spacer so as to be substantially parallel, the manufacture is relatively easy and simple.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details and embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a heat insulator according to a first embodiment of the present invention.
FIG. 2 is an enlarged sectional view of a peripheral portion of a bolt hole, and FIG. 3 is an enlarged sectional view of a peripheral portion of a spacer mounted on a peripheral portion of the heat insulator.
In the respective drawings, the same reference numerals indicate the same parts.

The heat insulator 1 according to the first embodiment comprises:
It comprises first and second insulator elements 2 and 3 which are formed in the shape of a cover and are opposed to and substantially parallel to each other, and a substantially constant gap 4 formed between the insulator elements 2 and 3. The first and second insulator elements 2 and 3 each have a steel plate 21 and 22 having a thickness of 0.2 mm to 0.5 mm, and a thickness of 0.5 mm sandwiched between the steel plates 21 and 22. And a heat insulating sound absorbing material layer 23 having a thickness of about 1.5 mm.

Glass wool, ceramic fiber sheets, mica sheets, and composites thereof are preferably used as the heat insulating sound absorbing material constituting the sound absorbing material layer 23. The steel plate 21, the sound-absorbing material layer 23, and the steel plate 22 are integrally connected as needed, for example, by eyelets. The thickness of the insulator elements 2 and 3 is preferably in the range of 1.0 to 2.0 mm, is relatively thin and is therefore easy to mold into a cover shape. The steel plates 21 and 22 may be other types of metal plates such as a stainless steel plate.

[0013] Spacers 5 and 6 which are arranged in a dot-like manner are locally interposed between the first and second insulator elements 2 and 3 to form a gap 4 having a substantially constant interval.
In FIG. 1, the spacers 5 and 6 are schematically shown, and the details thereof are shown in FIGS. 2 and 3. FIG. 2 is an enlarged cross-sectional view of a peripheral portion of a bolt hole 7 through which a bolt for attaching the heat insulator to a high-temperature device such as an exhaust manifold is inserted. As shown in FIG. 2, the spacer 5 is made of eyelets, and the bolt hole 7 of the heat insulator 1 is provided.
Has been inserted.

The spacer 5 sandwiches the first insulator element 2 by a spacer portion 52 located at the center in the axial direction and a caulked portion 53 at the upper end in the axial direction, and a caulked portion at the lower end in the axial direction. 54 and the second
, The first insulator 2 and the second insulator element 3 are integrally connected. The spacers 5 form the gaps 4 between the first insulator element 2 and the second insulator element 3 which are substantially parallel to each other and have an interval equal to the axial length of the spacer portion. The inner surface of the cylinder at the center of the spacer 5 forms a bolt insertion hole 51. FIG. 5 is a cross-sectional view of the spacer 5 before being attached to the heat insulator and before being caulked, and the spacer portion at the center in the axial direction is formed by bending.

The spacer 6 is also made of an eyelet and is locally attached to the peripheral portion 8 of the heat insulator 1 as shown in FIG. 3, and the first portion is formed by a spacer portion 62 at the center of the spacer 6 and a caulking portion 63 at the upper end. The insulator element 2 is sandwiched, the second insulator element 3 is sandwiched by the spacer portion 62 and the caulking portion 64 at the lower end, and the space 62 is provided between the first and second insulator elements 2 and 3 by the spacer portion 62. Is formed. FIG. 8 is a cross-sectional view of the spacer 6 before being attached to the heat insulator and before being caulked. However, in FIG. 8, a heat-resistant cushion material described later is provided above and below the spacer portion 62.

The spacers 5 and 6 are not limited to the spacers shown in FIGS. 2 and 3, but other types of spacers can be used. As the spacer used for the bolt hole 7, a washer-shaped spacer 5 'as shown in FIG. 6 may be used. In this case, the spacer 5 'may be connected to the steel plates of the insulator elements 2 and 3 by spot welding, or may be connected to the insulator elements 2 and 3 by caulking eyelets inserted into the bolt holes 7. FIG. 7 shows another example 6 ′ of the spacer mounted on the peripheral portion 8 of the heat insulator 1. The figure on the left shows a cross-sectional view before mounting and before caulking, and the figure on the right shows a cross-sectional view after caulking.
The spacer portion 62 of the spacer 6 'is formed by bending.

As shown in FIG. 8, these spacers are preferably mounted on a heat insulator by interposing a heat-resistant cushioning material 9 between the spacer portion and an insulator element abutting on the spacer portion. The vibration of the heat insulator can be prevented and reduced by the elastic cushion material 9. In addition, the size of the gap 4 can be adjusted by interposing a heat-resistant cushion material. As the heat-resistant cushion material, a stainless steel wire, a mesh molded product made of a steel wire or an iron wire, glass wool, a ceramic fiber sheet, a mica sheet, or the like can be preferably used. In the heat insulator according to the present invention, if it is found from a vibration test or the like in a state where the heat insulator is attached to a high-temperature equipment section that the heat insulator resonates with engine vibration or the like, a two-layer insulator element is used. The vibration can be easily prevented or reduced by reselecting the arrangement position of the spacers that are connected to the heat insulator, or by adding a spacer to the abdominal part of the vibration of the heat insulator and reinforcing it.

FIG. 4 is a sectional view of a heat insulator 11 according to a second embodiment of the present invention. Heat insulator 1
In 1, the first insulator element 3 is formed by a single steel plate 31. Except for this point, it is the same as the heat insulator 1 of the first embodiment shown in FIG. The second insulator element 3 may be formed by stacking two steel plates, or may be formed by another type of metal plate such as stainless steel instead of the steel plate. Spacer 5 in FIG.
1 and 6 are simulated similarly to FIG.
3 and the same spacer as described with reference to FIGS.

The preferred range of the size of the gap 4 between the first and second insulators in the heat insulator according to the present invention is 0.5 mm to 5.0 mm. Therefore, the thickness of the heat insulator of the present invention is usually about 2.5 mm to 7.0 mm. Since the first and second insulator elements 2 and 3 have a relatively small thickness and some flexibility, when the insulator elements are molded into a cover shape, both the first and second insulator elements are required. Both are molded in the same shape using the same mold, and they are connected via the spacers 5 and 6, so that they can be arranged substantially parallel and opposed to each other, so that the manufacturing cost can be reduced.

[0020]

As described above, the heat insulator of the present invention is sandwiched between the air layer of the gap 4 formed between the first and second insulator elements and the metal plate of at least one of the insulator elements. The heat insulation, the sound insulation and the sound absorption are greatly improved as compared with the conventional heat insulator. The insulator of the present invention can be formed by superimposing and connecting two layers of insulator elements molded in the shape of a cover so as to face each other substantially in parallel via a spacer so as to form a gap. Since it is relatively thin and easy to mold, it can be manufactured relatively easily and easily.

In the present invention, as described above, 2
The spacers which connect the insulator elements of the layers in substantially parallel opposition and form voids 4 between the insulator elements are locally dispersed in a point-like manner, so by selecting the position of the spacers or By additionally reinforcing the spacer, it is possible to easily prevent and reduce the resonance of the heat insulator with the vibration of the high-temperature equipment section that blocks the heat. Further, since the air gap 4 allows air to enter and exit freely, it has an effect of cooling the heat insulator when it becomes hot. When the heat insulator of the present invention is used for an exhaust portion of an automobile engine, there is also an effect that the heat insulation at the time of cold start is excellent.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention. However, the spacers 5 and 6 are schematically shown.

FIG. 2 is a partially enlarged view of a peripheral portion of a bolt hole 7 in FIG. 1;

FIG. 3 is a partially enlarged view of a peripheral portion of a spacer 6 mounted on a peripheral portion of FIG. 1;

FIG. 4 is a sectional view of a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a spacer 5 before swaging.

FIG. 6 is a sectional view of another example of a spacer applied to a bolt hole.

FIG. 7 is a cross-sectional view of another example of a spacer applied to an edge.

FIG. 8 is an explanatory view of a spacer with a heat-resistant cushion material interposed.

FIG. 9 is a perspective view of an exhaust manifold of an engine and a heat insulator used as a heat shield cover of the exhaust manifold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Heat insulator 2, 3 Insulator element 4 Air gap 5, 6 Spacer 7 Bolt hole part 9 Heat resistant cushion material 21, 22 Steel plate 23 Sound absorbing material layer 52, 62 Spacer part

Claims (5)

[Claims] 1. A cover for heat-insulating a high-temperature device such as an exhaust manifold of an engine, comprising two layers of insulator elements substantially parallel to each other and a substantially constant interval formed between the insulator elements. A heat insulator comprising a gap, wherein at least one layer of the insulator element is formed by a two-layer metal plate with a heat insulating sound absorbing material layer interposed therebetween. 2. The heat insulator according to claim 1, wherein another layer in the insulator element is formed only of a metal plate. 3. The sound absorbing material layer comprises one of glass wool, a ceramic fiber sheet, a mica sheet, and a composite of two or more thereof.
The heat insulator according to 1. 4. The heat insulator according to claim 1, wherein the two-layered insulator element molded into the shape of the cover is sandwiched and connected so as to be substantially parallel by the spacers arranged in a distributed manner. . 5. The heat insulator according to claim 4, wherein the spacer is an eyelet provided with a spacer for forming a gap.