Heat insulator

Abstract

To provide a heat insulator capable of suppressing heat damage.SOLUTION: A heat insulator covers an exhaust pipe of an internal combustion engine. A component is provided in the exhaust pipe. The heat insulator includes: a plate part that covers the exhaust pipe; and a cylindrical part projecting from the plate part toward the exhaust pipe. In the heat insulator, at least a part of the component is located outside the exhaust pipe and inside of the cylindrical part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a heat insulator.

Background Art

[0002] The turbocharger of an internal combustion engine may be covered with a heat insulator (for example, Patent Document 1, etc.). The heat insulator protects the components from heat.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the components cannot be sufficiently protected, and there is a risk of heat damage. For example, an air-fuel ratio sensor (A / F sensor) is arranged near the catalyst of an exhaust pipe. Heat damage may occur when the A / F sensor is exposed to heat. Therefore, an object is to provide a heat insulator capable of suppressing heat damage.

Means for Solving the Problems

[0005] The above object can be achieved by a heat insulator that covers an exhaust pipe of an internal combustion engine, wherein a component is provided on the exhaust pipe, and the heat insulator includes a plate portion that covers the exhaust pipe and a cylindrical portion that protrudes from the plate portion toward the exhaust pipe, and at least a part of the component is located outside the exhaust pipe and inside the cylindrical portion.

Effects of the Invention

[0006] A heat insulator capable of suppressing heat damage can be provided. <0000​​

[0007] [Figure 1] Figure 1 is a schematic diagram illustrating an exhaust pipe according to the first embodiment. [Figure 2] Figure 2(a) is a cross-sectional view illustrating an exhaust pipe and a heat insulator. Figure 2(b) is a cross-sectional view illustrating an exhaust pipe and a heat insulator according to a comparative example. [Figure 3] Figure 3(a) is a cross-sectional view illustrating an exhaust pipe and heat insulator according to the second embodiment. Figure 3(b) is a cross-sectional view illustrating an exhaust pipe and heat insulator according to the third embodiment. Figure 3(c) is a cross-sectional view illustrating an exhaust pipe and heat insulator according to the fourth embodiment. [Modes for carrying out the invention]

[0008] The heat insulator of this embodiment will be described below with reference to the drawings. However, the dimensions and proportions of each part in the drawings may not perfectly match those of the actual parts. Also, some details may be omitted in the drawings.

[0009] <First Embodiment> Figure 1 is a schematic diagram illustrating an exhaust pipe 20 according to the first embodiment. The exhaust pipe 20 is connected to an internal combustion engine 10. The internal combustion engine 10 is, for example, a gasoline engine, which burns fuel to generate driving force. The exhaust gas generated by combustion is discharged through the exhaust pipe 20.

[0010] The exhaust pipe 20 is equipped with a turbocharger turbine 12 and a catalytic converter 14, in order from the upstream side. An air-fuel ratio sensor (A / F sensor) 16 (part) is installed, for example, between the turbine 12 and the catalytic converter 14. The A / F sensor 16 measures the air-fuel ratio.

[0011] The turbine 12 rotates when exhaust gas is blown onto it. A compressor (not shown) connected to the turbine 12 rotates with the turbine 12, supercharging the air. The output of the internal combustion engine 10 is increased. The catalyst 14 purifies the exhaust gas.

[0012] The heat insulator 30 is located outside the exhaust pipe 20 and covers the portion of the exhaust pipe 20 in which the turbine 12 and A / F sensor 16 are installed. The heat insulator 30 is spaced apart from the outer wall of the exhaust pipe 20.

[0013] Figure 2(a) is a cross-sectional view illustrating the exhaust pipes 20 and the heat insulator 30. In Figure 2(a), two exhaust pipes 20 are arranged side by side. A / F sensors 16 are provided on both of the two exhaust pipes 20. The A / F sensors 16 are rod-shaped and are inserted into the exhaust pipes 20. Part of the A / F sensor 16 is located inside the exhaust pipes 20, and the other part is exposed on the outside of the exhaust pipes 20.

[0014] The cover 18 is cylindrical and protrudes outward from the outer wall of the exhaust pipe 20, enclosing the portion of the A / F sensor 16 that is located outside the exhaust pipe 20. The cover 18 is spaced apart from the A / F sensor 16 and the heat insulator 30.

[0015] The heat insulator 30 has a plate portion 32 and a cylindrical portion 34. The plate portion 32 is a plate-shaped part that covers the exhaust pipe 20. A hole 36 is provided in the plate portion 32. The A / F sensor 16 is inserted into the hole 36 and attached to the exhaust pipe 20.

[0016] The cylindrical portion 34 of the heat insulator 30 is a cylindrical part located inside the hole 36 and protrudes from the plate portion 32 toward the exhaust pipe 20. The cylindrical portion 34 covers the portion of the A / F sensor 16 that is exposed outside the exhaust pipe 20. That is, a part of the A / F sensor 16 is located outside the exhaust pipe 20 and is surrounded by the cover 18 and the cylindrical portion 34 of the heat insulator 30.

[0017] (Comparative example) Figure 2(b) is a cross-sectional view illustrating an exhaust pipe 20 and a heat insulator 30 according to a comparative example. The heat insulator 30 does not have a cylindrical portion 34. The A / F sensor 16 is covered by the cover 18, but not by the cylindrical portion. A portion of the A / F sensor 16 is also exposed from the cover 18.

[0018] High-temperature gas may accumulate between the exhaust pipe 20 and the heat insulator 30. When the A / F sensor 16 is exposed to the high-temperature gas, heat damage may occur to the A / F sensor 16. Among the A / F sensor 16, the portion not covered by the cover 18 is likely to come into contact with the gas and is highly likely to suffer heat damage.

[0019] According to the first embodiment, the heat insulator 30 has a cylindrical portion 34. The A / F sensor 16 is provided in the exhaust pipe 20 and is located inside the cylindrical portion 34. By surrounding the A / F sensor 16 with the cylindrical portion 34, the A / F sensor 16 is less likely to be exposed to high-temperature gas. The occurrence of heat damage can be suppressed.

[0020] A part of the A / F sensor 16 is located outside the exhaust pipe 20. Since the said portion of the A / F sensor 16 is surrounded by the cover 18 and the cylindrical portion 34, it is less likely to be exposed to the gas. Heat damage is effectively suppressed. The component protected by the cylindrical portion 34 may be a sensor other than the A / F sensor 16, or a component other than a sensor. At least a part of the component is located outside the exhaust pipe 20 and is surrounded by the cylindrical portion 34. The entire component may be located outside the exhaust pipe 20 and surrounded by the cylindrical portion 34.

[0021] <Second Embodiment> FIG. 3(a) is a cross-sectional view illustrating the exhaust pipe 20 and the heat insulator 30 according to the second embodiment. The description of the same configuration as that of the first embodiment is omitted. As shown in FIG. 3(a), the cylindrical portion 34 of the heat insulator 30 extends into the inside of the cover 18.

[0022] According to the second embodiment, the cylindrical portion 34 overlaps with the cover 18. By covering the A / F sensor 16 with the cylindrical portion 34 and the cover 18 and providing double protection, heat damage can be effectively suppressed.

[0023] <Third Embodiment> Figure 3(b) is a cross-sectional view illustrating the exhaust pipe 20 and heat insulator 30 according to the third embodiment. Descriptions of the same configuration as in the first or second embodiment are omitted. As shown in Figure 3(b), the cylindrical portion 34 extends from the plate portion 32 to the outer wall of the exhaust pipe 20. The cover 18 is not provided.

[0024] According to the third embodiment, the entire portion of the A / F sensor 16 located outside the exhaust pipe 20 is surrounded by the cylindrical portion 34. This effectively suppresses heat damage. Since a cover 18 is not required, mass and cost can be reduced.

[0025] <Fourth Embodiment> Figure 3(c) is a cross-sectional view illustrating the exhaust pipe 20 and heat insulator 30 according to the fourth embodiment. Descriptions of the same configuration as in any of the first to third embodiments are omitted. A heat insulating material 38 is provided on the outer wall of the cylindrical portion 34. The cylindrical portion 34 and the heat insulating material 38 overlap the cover 18.

[0026] According to the fourth embodiment, since the heat insulating material 38 is provided in the cylindrical portion 34, the temperature of the cylindrical portion 34 does not rise easily. The A / F sensor 16 is surrounded by the heat insulating material 38 and the cylindrical portion 34 and is protected by the low temperature of the cylindrical portion 34. Radiation is less likely to occur around the A / F sensor 16, and heat damage can be effectively suppressed. The heat insulating material 38 may also be provided on the inner wall of the cylindrical portion 34.

[0027] The third and fourth embodiments may be combined. The cylindrical portion 34 and the heat insulating material 38 extend to the exhaust pipe 20.

[0028] Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the invention as described in the claims. [Explanation of Symbols]

[0029] 10 Internal combustion engine, 12 Turbine, 14 Catalyst, 16 A / F sensor, 18 Cover, 20 Exhaust pipe, 30 Heat insulator, 32 Plate section, 34 Cylinder section, 36 Hole, 38 Thermal insulation material

Claims

[Claim 1] A heat insulator that covers the exhaust pipe of an internal combustion engine, A component is provided in the exhaust pipe. A cylindrical cover is provided that protrudes outward from the outer wall of the exhaust pipe and surrounds the portion of the component that is exposed outside the exhaust pipe, at a distance from the portion of the component that is exposed outside the exhaust pipe. The heat insulator comprises a plate portion that covers the exhaust pipe, A cylindrical portion that protrudes from the plate portion toward the exhaust pipe, overlaps the cover, and covers the portion of the component that is exposed outside the exhaust pipe, An insulating material provided on the outer or inner wall of the cylindrical portion, which overlaps with the cover together with the cylindrical portion, It is equipped with, At least a portion of the aforementioned component is a heat insulator located on the outside of the exhaust pipe and on the inside of the cylindrical portion.

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