JP2008240589A - Engine exhaust structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine exhaust structure having reduced manufacturing cost while sufficiently securing the heat resistance of an exhaust manifold by uniformly controlling the temperatures of portions of the exhaust manifold. <P>SOLUTION: To uniform the temperatures of the portions of the exhaust manifold 11, a temperature control material 31 is provided for controlling the temperature of the exhaust manifold 11. The temperature control material 31 has a heat transfer material 31A of high heat transmissivity laminated on a site of a cover member 25 corresponding to a high temperature site HT of the exhaust manifold 11. The temperature control material 31 has a heat insulating material 31B laminated on a site of the cover member 25 corresponding to a low temperature site LT of the exhaust manifold 11. The temperature control material 30 has a heat release material 31C of which a coating is applied to a site of the cover member 25 corresponding to a high temperature site of the exhaust manifold 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine exhaust structure.

  An exhaust manifold, a catalytic converter, and a muffler are placed in order from the upstream side in the middle of the exhaust passage of an automobile engine. The exhaust gas from the engine is collected by the exhaust manifold and purified through the catalytic converter. After that, the sound is silenced by the muffler and discharged to the outside.

  As the catalytic converter, one that purifies exhaust gas with a three-way catalyst is the mainstream, but in a catalytic converter using this three-way catalyst, the exhaust gas is not exhausted unless the catalyst temperature becomes higher than the activation temperature. There is a problem that it is discharged outside as it is purified.

  Therefore, in order to shorten the time until the catalyst reaches the activation temperature or more after the engine is started, the catalytic converter is placed as close as possible to the exhaust manifold assembly to promote the catalyst temperature rise or the exhaust manifold exhaust It has been proposed that the gas flow passage is configured to have a double structure of inner member and outer member so that a heat insulating space is formed between the two members and the exhaust gas temperature in the exhaust manifold is prevented from lowering. (For example, refer to Patent Document 1).

  In addition, an exhaust manifold having a sound insulation cover for covering the exhaust manifold has been proposed (for example, see Patent Document 2). The invention described in Patent Document 2 is intended to insulate the noise from the engine and to protect the electronic device and its harness arranged in the engine room from the high-temperature exhaust manifold. Since the sound absorbing material provided in the cover on the cover functions as a heat insulating material, it is possible to promote the activation of the catalyst by promoting the increase in the ambient temperature surrounding the exhaust manifold.

JP-A-2005-76605 Japanese Patent Laid-Open No. 7-119458

  By the way, the temperature of the exhaust manifold is not uniform as a whole. For example, exhaust gas from each cylinder gathers at the gathering portion and the vicinity thereof, and therefore becomes higher than the other portions. For this reason, the exhaust manifold is designed to be heat resistant with reference to the temperature at the gathering portion and the vicinity thereof. However, when designed in this way, an expensive metal material with excellent heat resistance is used for low-temperature parts other than the gathering part and its vicinity, although heat resistance is not required as high-temperature parts. As a result, there was a problem that the manufacturing cost of the exhaust manifold was high. In particular, in order to promote an increase in the catalyst temperature during the warm-up operation and improve the exhaust gas purification performance, as in the inventions described in Patent Documents 1 and 2, the collecting portion and the multi-branch pipe have a double structure. Although the exhaust gas purification performance during warm-up operation can be improved by configuring or covering with a cover member, the temperature at the gathering section and its vicinity becomes excessively high after warm-up. However, there is a problem that the manufacturing cost of the exhaust manifold is significantly increased because it is necessary to be made of stainless steel having high nickel content, which is excellent in performance.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an engine exhaust structure that can reduce the manufacturing cost while ensuring sufficient heat resistance of the exhaust manifold by uniformly adjusting the temperature in each part of the exhaust manifold. .

  The exhaust structure of the engine according to the present invention is provided with a temperature adjusting material that adjusts the temperature of the exhaust manifold so that the temperature of each part of the exhaust manifold becomes uniform.

  In this exhaust structure, the temperature of the exhaust manifold is adjusted by the temperature adjusting material so that the temperature in each part of the exhaust manifold becomes uniform, and a local temperature rise of the exhaust manifold is prevented. For this reason, the requirements for the heat resistance of the exhaust manifold can be set low, and although the exhaust manifold can be configured with a metal material that is available at a low cost although it is somewhat inferior in heat resistance, the manufacturing cost of the exhaust manifold can be reduced.

  Here, a cover member that covers the exhaust manifold is provided, and a heat transfer material having a high thermal conductivity is provided in a laminated form at a portion corresponding to a high temperature portion of the exhaust manifold of the cover member as the temperature adjusting material. it can. In this case, the heat of the portion of the cover member corresponding to the high temperature portion of the exhaust manifold is efficiently transferred to the outer panel side of the cover member by the heat transfer material, and heat radiation to the outside at the portion is performed. Promoted. And the rise in the ambient temperature surrounding the high temperature part of the exhaust manifold is suppressed, and the local temperature rise of the exhaust manifold is prevented. For this reason, similarly to the above, the exhaust manifold can be made of an inexpensive metal material to the extent that local temperature rise is prevented, and the manufacturing cost can be reduced. In addition, since the exhaust manifold is covered by the cover member, the temperature rise of the exhaust manifold as a whole is promoted, the temperature of the catalyst of the catalytic converter is promoted, and the time until the catalyst exceeds the activation temperature is shortened. Gas purification performance can be improved.

  It is also a preferred embodiment that a cover member that covers the exhaust manifold is provided, and that a heat insulating material is provided in a laminated form at a portion corresponding to a low temperature portion of the exhaust manifold of the cover member as the temperature adjusting member. In this case, the heat of the part corresponding to the low temperature part of the exhaust manifold in the cover member is suppressed from being radiated to the outside by the heat insulating material. Then, the rise in the ambient temperature surrounding the low temperature portion of the exhaust manifold is promoted, the temperature in each part of the exhaust manifold is adjusted uniformly, and the local temperature rise in the exhaust manifold is prevented. For this reason, in the same manner as described above, the exhaust manifold can be made of an inexpensive metal material, and its manufacturing cost can be reduced. In addition, since the exhaust manifold is covered by the cover member, the temperature rise of the exhaust manifold as a whole is promoted, the temperature of the catalyst of the catalytic converter is promoted, and the time until the catalyst exceeds the activation temperature is shortened. Gas purification performance can be improved, and the exhaust manifold can be adjusted in temperature by suppressing heat dissipation from the cover member with a heat insulating material. Can promote the rise.

  A cover member that covers the exhaust manifold is provided, and as the temperature adjusting material, the cover member has a temperature adjustment in which the thermal conductivity of the portion corresponding to the high temperature portion of the exhaust manifold is higher than the portion corresponding to the low temperature portion of the exhaust manifold. It is also a preferred embodiment to provide the materials in a laminated form. In this case, heat dissipation from the outer panel of the cover member to the outside is promoted at the high temperature portion by the temperature adjusting material, and heat dissipation from the outer panel of the cover member to the outside is suppressed at the low temperature portion. And the atmospheric temperature surrounding the exhaust manifold is adjusted more effectively and uniformly, the temperature in each part of the exhaust manifold is adjusted uniformly, and the local temperature rise of the exhaust manifold is prevented. For this reason, in the same manner as described above, the exhaust manifold can be made of an inexpensive metal material, and its manufacturing cost can be reduced. In addition, since the exhaust manifold is covered by the cover member, the temperature rise of the exhaust manifold as a whole is promoted, the temperature of the catalyst of the catalytic converter is promoted, and the time until the catalyst exceeds the activation temperature is shortened. Gas purification performance can be improved.

  It is also a preferred embodiment that a cover member that covers the exhaust manifold is provided, and a heat radiating material is coated on the outer surface of a portion of the cover member corresponding to the high temperature portion of the exhaust manifold as the temperature adjusting material. In this case, the heat of the portion of the cover member corresponding to the high temperature portion of the exhaust manifold is efficiently radiated to the outside by the heat radiating material, so that an increase in the ambient temperature surrounding the high temperature portion of the exhaust manifold is suppressed. Thus, the temperature of each part of the exhaust manifold is adjusted uniformly, and the local temperature rise of the exhaust manifold is prevented. For this reason, the requirement for the heat resistance of the exhaust manifold can be set low as described above, and the exhaust manifold can be made of an inexpensive metal material, so that the manufacturing cost of the exhaust manifold can be reduced.

  A cover member that covers the exhaust manifold may be provided, and a heat transfer material having a high thermal conductivity may be provided in a laminated form between the cover member and the high temperature portion of the exhaust manifold as the temperature adjusting material. In this case, the heat of the exhaust manifold is transferred to the cover member side by the heat transfer material at the high temperature part of the exhaust manifold, and the temperature of each part of the exhaust manifold is adjusted uniformly, and the local temperature of the exhaust manifold is adjusted. The rise is prevented. For this reason, similarly to the above, the requirement for heat resistance of the exhaust manifold can be set low, the exhaust manifold can be made of an inexpensive metal material, and the manufacturing cost of the exhaust manifold can be reduced.

  A cover member that covers the exhaust manifold may be provided, and as the temperature adjusting material, a heat insulating material may be provided in a laminated form at a portion corresponding to a low temperature portion of the cover member and the exhaust manifold. In this case, the heat insulating material prevents the heat of the portion corresponding to the low temperature portion of the exhaust manifold of the cover member from being radiated to the outside. And the temperature rise of the low temperature part of an exhaust manifold is accelerated | stimulated, the temperature of each part of an exhaust manifold is adjusted uniformly, and the local temperature rise of an exhaust manifold is prevented. For this reason, similarly to the above, the requirements for the heat resistance of the exhaust manifold can be set low, the exhaust manifold can be made of an inexpensive metal material, and the manufacturing cost of the exhaust manifold can be reduced.

  A cover member that covers the exhaust manifold is provided, and the thermal conductivity of the portion corresponding to the high temperature portion of the exhaust manifold is set between the cover member and the exhaust manifold as the temperature adjusting material more than the portion corresponding to the low temperature portion of the exhaust manifold. It is also a preferred embodiment to provide an elevated temperature adjusting material in a laminated form. In this case, the temperature adjusting material promotes heat transfer from the exhaust manifold to the cover member at high temperatures, and suppresses heat transfer from the exhaust manifold to the cover members at low temperatures. The temperature at is adjusted uniformly to prevent a local temperature rise in the exhaust manifold. For this reason, similarly to the above, the requirements for the heat resistance of the exhaust manifold can be set low, the exhaust manifold can be made of an inexpensive metal material, and the manufacturing cost of the exhaust manifold can be reduced.

  A part or all of the exhaust manifold is configured in a double structure composed of an inner member and an outer member, and the temperature adjusting material has a thermal conductivity between the inner member and the outer member at a high temperature portion of the exhaust manifold. It is also a preferred embodiment to provide a high heat transfer material in a laminated form. In this case, the heat of the inner member is transferred to the outer member side by the heat transfer material at the high temperature part of the exhaust manifold, heat dissipation from the outer part is promoted, and the temperature of each part of the exhaust manifold is adjusted uniformly. Thus, a local temperature rise of the exhaust manifold is prevented. For this reason, similarly to the above, the requirements for the heat resistance of the exhaust manifold can be set low, the exhaust manifold can be made of an inexpensive metal material, and the manufacturing cost of the exhaust manifold can be reduced. In addition, since the exhaust manifold has a double structure of the inner member and the outer member, the temperature rise of the entire inner member is promoted, the temperature rise of the catalyst of the catalytic converter is promoted, and the catalyst becomes higher than the activation temperature. The exhaust gas purification performance can be improved.

  A part or all of the exhaust manifold is configured in a double structure composed of an inner member and an outer member, and a heat insulating material is laminated between the inner member and the outer member at the low temperature portion of the exhaust manifold as the temperature adjusting material. It can also be provided in a shape. In this case, the heat of the inner member is blocked by the heat insulating material at the low temperature portion, and the heat transfer to the outer member is suppressed, so that the temperature of each part of the exhaust manifold is adjusted uniformly, and the local part of the exhaust manifold Temperature rise is prevented. For this reason, similarly to the above, the requirements for the heat resistance of the exhaust manifold can be set low, the exhaust manifold can be made of an inexpensive metal material, and the manufacturing cost of the exhaust manifold can be reduced. In addition, since the exhaust manifold has a double structure of the inner member and the outer member, the temperature rise of the entire inner member is promoted, the temperature rise of the catalyst of the catalytic converter is promoted, and the catalyst becomes higher than the activation temperature. The exhaust gas purification performance can be shortened, and the heat of the exhaust gas can be adjusted by adjusting the temperature of the exhaust manifold by preventing heat dissipation from the inner member with a heat insulating material. By acting on the catalytic converter, the temperature rise of the catalyst can be promoted.

  A part or all of the exhaust manifold is configured in a double structure composed of an inner member and an outer member, and as the temperature adjusting material, the thermal conductivity of the high temperature portion of the exhaust manifold is set between the inner member and the outer member. It is also a preferred embodiment to provide a temperature adjusting material having a higher temperature than that of the low temperature region in a laminated form. In this case, the temperature adjusting material promotes heat radiation from the inner member to the outer member at the high temperature portion, and suppresses heat radiation from the inner member to the outer member at the low temperature portion. The temperature at can be adjusted more efficiently and uniformly, and a local temperature rise of the exhaust manifold can be prevented. For this reason, similarly to the above, the requirements for the heat resistance of the exhaust manifold can be set low, the exhaust manifold can be made of an inexpensive metal material, and the manufacturing cost of the exhaust manifold can be reduced. In addition, since the exhaust manifold is covered by the cover member, the temperature rise of the exhaust manifold as a whole is promoted, the temperature of the catalyst of the catalytic converter is promoted, and the time until the catalyst exceeds the activation temperature is shortened. Gas purification performance can be improved.

  In a preferred embodiment, the high temperature portion is a portion including at least a collecting portion of the exhaust manifold. The exhaust manifold collects exhaust gas from each cylinder of the engine and gets hot at the collecting part of the exhaust manifold, so that the part including the collecting part is the high temperature part and the other multi-branch pipe part is the low temperature part, and the temperature of both It can be adjusted to be uniform.

  According to the exhaust structure of an engine according to the present invention, the temperature of the exhaust manifold is adjusted by the temperature adjusting material so that the temperature in each part of the exhaust manifold is uniform, and the local temperature rise of the exhaust manifold is prevented. Is done. For this reason, the requirements for the heat resistance of the exhaust manifold can be set low, and although the exhaust manifold can be configured with a metal material that is available at a low cost although it is somewhat inferior in heat resistance, the manufacturing cost of the exhaust manifold can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the basic structure of the exhaust structure of an automobile engine will be described.
An engine 10 shown in FIG. 1 is an in-line four-cylinder engine for automobiles, and an exhaust manifold 11, a catalytic converter 12, and a muffler (not shown) are provided in order from the upstream side in the middle of the exhaust passage of the engine 10. The exhaust gas from the engine 10 is collected by the exhaust manifold 11, purified through the catalytic converter 12, and then silenced by the muffler and discharged to the outside.

  As shown in FIGS. 1 to 3, the exhaust manifold 11 includes four multi-branches 15 respectively connected to four exhaust ports 14 formed in the cylinder head 13, and the four multi-branches 15. A collecting pipe 16 formed by gathering the downstream ends and an outer member 17 each covering a pair of adjacent multi-branched pipes 15 are provided.

  Between the outer member 17 and the multi-branch tube 15, a cylindrical first gap 18 of, for example, 1.0 to 4.0 mm is formed over substantially the entire length. Both outer members 17 are divided into an upper surface plate 17U and a lower surface plate 17L, and the upper surface plate 17U and the lower surface plate 17L are combined by combining the upper surface plate 17U and the lower surface plate 17L so that the multi-branch tube 15 is disposed inside. These butted portions are welded and joined so as to surround the multi-branch tube 15. A bifurcated branch portion 17 a is formed at the upstream end portions of the outer members 17, and the upstream end portions of the multi-branch pipes 15 are individually fitted into the branch portions 17 a of the outer member 17. At the upstream end portion, an overlapping end portion 17b is formed by reducing the diameter of the upstream end portion of the branching portion 17a and overlapping the upstream end portion of the multi-branch pipe 15. A mounting plate 19 to the cylinder head 13 is provided at the upstream end portion of the exhaust manifold 11, and four through holes 20 are formed in the mounting plate 19 corresponding to the exhaust ports 14, and overlapped with these four through holes 20. The four multi-branch pipes 15 and the two outer members 17 are integrated via the attachment plate 19 by inserting and welding the portions 17b. A downstream end of the outer member 17 is welded to the collecting pipe 16, and a spacer member 21 for preventing vibration of the multi-branched pipe 15 is interposed between the downstream end of the multi-branched pipe 15 and the downstream end of the outer member 17. It is intervened. Further, a flange member 22 for connection to the downstream exhaust pipe is welded to the downstream end portion of the collecting pipe 16.

  Cover members 25 for blocking noise and heat from the exhaust manifold 11 are provided on both upper and lower sides of the exhaust manifold 11, and the upper and lower cover members 25 are exhausted via bracket members 26 provided on the exhaust manifold 11. A second gap 27 is formed between the exhaust manifold 11 and the cover member 25. However, the lower cover member 25 may be omitted.

  The upper and lower cover members 25 include an outer panel 28 disposed on the outer surface side and an inner panel 29 disposed on the exhaust manifold 11 side, and a third gap 30 is formed between the outer panel 28 and the inner panel 29. In the third gap 30, a sound absorbing material or a temperature adjusting material 31 as will be described later is provided in close contact with the outer panel 28 and the inner panel 29. The outer panel 28 and the inner panel 29 are manufactured by press-molding a metal plate made of a stainless steel plate or the like. However, the inner panel 29 can be made of general-purpose punching metal or mesh in order to improve sound absorption.

  In the exhaust structure of the engine 10 having the basic configuration as described above, the present invention is characterized in that a temperature adjusting material for uniformly adjusting the temperature of each part of the exhaust manifold 11 is provided as shown in FIG. It is.

  Here, since the temperature of the exhaust manifold 11 becomes higher as it goes from the cylinder head 13 toward the collecting pipe 16, the boundary B between the low temperature portion LT and the high temperature portion HT as shown in FIG. 4. However, when the pipe length from the upstream end of the multi-branch pipe 15 to the boundary B is L1, and the pipe length from the boundary B to the downstream end of the collecting pipe 16 is L2, the boundary B is L1 / (L1 + L2) It can be set within a range of 20 to 35%.

  As the temperature adjusting material 31, the heat transfer material 31 </ b> A can be provided without any gap in one or more types of high-temperature portions HT selected from the first gap 18, the second gap 27, and the third gap 30. Moreover, the heat insulating material 31B can be provided without a gap in one or more types of low-temperature portions LT selected from the first gap 18, the second gap 27, and the third gap 30. Furthermore, the heat radiating material 31C can be coated on the outer surface of at least one of the high-temperature portions HT of the exhaust manifold 11 and the cover member 25. However, since the first gap 18 between the multi-branch tube 15 and the outer member 17 functions as a heat insulating space, the heat insulating material 31B of the low temperature region LT can be omitted. When the heat transfer material 31A is provided in the high temperature part HT of the second gap 27, the coating of the heat radiation material 31C on the outer surface of the high temperature part HT of the exhaust manifold 11 can be omitted. Furthermore, regarding the third gap 30, when the heat transfer material 31 </ b> A or the heat insulating material 31 </ b> B is not provided, a sound absorbing material is provided at that location. The temperature adjusting material 31 may be provided so that the temperature of each part of the exhaust manifold 11, particularly the temperature of each part of the multi-branch pipe 15 and the collecting pipe 16, may be adjusted uniformly. It can be provided at a location.

  In particular, as shown in the figure, a heat transfer material 31A is provided in each of the high temperature portions HT of the first gap 18 and the second gap 27, and a heat radiating material 31C is coated on the outer surface of the cover member 25. When the heat insulating material 31B is provided on the LT, the heat of the high temperature portion HT of the exhaust manifold 11 is efficiently transferred to the cover member 25 side by the heat transfer material 31A, and the heat is released from the heat radiating material 31C on the outer surface of the cover member 25 to the outside. As a result, it is possible to prevent the downstream portion of the multi-branch tube 15 and the collecting pipe 16 that have the strictest requirements for heat resistance from becoming excessively hot, and to improve the heat retaining property on the upstream side of the multi-branch tube 15, and Ascending is promoted, and the temperature of each part of the multi-branch pipe 15 and the collecting pipe 16 can be adjusted uniformly throughout.

  As the heat insulating material 31B, an inorganic fiber such as glass fiber, rock wool fiber, ceramic fiber or potassium titanate fiber, or an organic fiber such as PBO (polyparaphenylene benzobisoxazole) fiber is preferably formed into a mat shape. Can be adopted.

  As the heat transfer material 31A, metal fibers such as stainless fibers, stainless fibers, steel fibers, copper fibers, brass fibers, bronze fibers, and aluminum fibers, carbon fibers such as pitch-based carbon fibers and PAN-based carbon fibers, and metal-plated fibers A material formed into a mat shape can be used. When the first gap 18 between the outer member 17 and the multi-branch pipe 15 and the third gap 30 between the outer panel 28 and the inner panel 29 of the cover member 25 are configured to be sealed, these gaps are used. 18 and 30 may be filled with carbon powder, graphite powder, aluminum powder, copper powder, brass powder, or bronze powder alone or in any combination. Further, when the fiber material is formed into a mat shape, the above-mentioned powder can be supported.

  As the heat dissipating material 31C, a ceramic heat dissipating paint such as COOLTECH (manufactured by Okitsumo Co., Ltd.) can be suitably employed. Moreover, it is also possible to stick a silicon-based or acrylic heat-dissipating sheet as the heat dissipating material 31C.

  In addition, the temperature adjusting material 31 assembled | attached to a different site | part can also be comprised with the same kind of raw material, and can also be comprised with a different raw material. In the present embodiment, the exhaust manifold 11 is divided into two regions, a low temperature region LT and a high temperature region HT. However, the exhaust manifold 11 is divided into three regions of a high temperature region, a medium temperature region, and a low temperature region, or more regions. The temperature of each part of the exhaust manifold 11 can be adjusted to be uniform. Furthermore, the temperature adjusting material 31 can be used to adjust the temperature of the exhaust manifold 11 more finely by using a material whose heat insulating properties and heat transfer properties are changed stepwise or continuously.

  In addition, the present invention can be applied to an exhaust structure of the engine 10 that does not have the outer member 17 or a member that does not have the cover member 25. When the outer member 17 is not provided, the cover member A heat insulating material 31B or a heat transfer material 31A is provided in at least one of the second gap 27 between the 25 and the multi-branch pipe 15 and the third gap 30 between the outer panel 28 and the inner panel 29 of the cover member 25. 15 or the high temperature part HT of the outer surface of the collecting pipe 16 or the outer surface of the cover member 25 is coated with the heat radiation material 31C. Further, when the cover member 25 is not provided, a heat insulating material 31B or a heat transfer material 31A is provided in the first gap 18 between the outer member 17 and the multi-branch pipe 15, or the outer surface of the outer member 17 or the collecting pipe 16 The heat dissipating material 31C is provided on the surface. Further, when the cover member 25 is a cover member in which the third gap 30 is not formed between the outer panel 28 and the inner panel 29 or a cover member made of a single panel, the outer member 17 and the multi-branch tube are used. Insulating material 31B and heat transfer material 31A are provided in the first gap 18 between the cover member 15 and the second gap 27 between the cover member and the multi-branch tube 15, or the high temperature portion on the outer surface of the exhaust manifold 11 or the outer surface of the cover member. The heat dissipation material 31C is coated on the HT.

  The present invention can be applied to the exhaust manifold 11 having an arbitrary configuration. For example, as shown in the figure, the present invention can also be applied to an exhaust manifold 41 having four branch pipes 40 having different lengths. Moreover, the present invention can also be applied to an exhaust manifold provided with an outer member that individually surrounds each multi-branch pipe 15 as the outer member 17. Furthermore, when providing an outer member that individually surrounds each multi-branch tube 15 in this manner, the outer member can be divided into an upper surface plate and a lower surface plate and welded together as described above, The outer member 17 made of a pipe member having a diameter larger than that of the multi-branch tube 15 can be externally mounted on the multi-branch tube 15. The present invention can also be applied to an exhaust structure of a multi-cylinder in-line engine other than the 4-cylinder in-line engine 10 or a multi-cylinder V-type engine.

Perspective view of the main part of the engine exhaust structure Front view of exhaust manifold Sectional view taken along the line III-III in FIG. 2 with the cover member assembled and the temperature adjusting material removed. Fig. 3 equivalent view with temperature adjustment material assembled Front view of exhaust manifold with other configurations

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine 11 Exhaust manifold 12 Catalytic converter 13 Cylinder head 14 Exhaust port 15 Multi-branch pipe 16 Collecting pipe 17 Outer member 17a Branching part 17b Superposition part 17U Upper surface board 17L Lower surface board 18 1st clearance 19 Mounting plate 20 Through-hole 21 Spacer member 22 Flange member 25 Cover member 26 Bracket member 27 Second gap 28 Outer panel 29 Inner panel 30 Third gap 31 Temperature adjustment material 31A Heat transfer material 31B Heat insulation material 31C Heat radiation material 40 Branch pipe 41 Exhaust manifold HT High temperature area LT Low temperature area

Claims (12)

  An exhaust structure for an engine, characterized in that a temperature adjusting material for adjusting the temperature of the exhaust manifold is provided so that the temperature of each part of the exhaust manifold becomes uniform.   The cover member which covers the said exhaust manifold is provided, The heat transfer material with high heat conductivity was provided in the laminated | stacked form in the site | part corresponding to the high temperature site | part of the exhaust manifold of the cover member as the said temperature adjustment material. Engine exhaust structure.   The engine exhaust according to claim 1 or 2, wherein a cover member that covers the exhaust manifold is provided, and a heat insulating material is provided in a layered manner on a portion of the cover member corresponding to a low temperature portion of the exhaust manifold as the temperature adjusting member. Construction.   A cover member that covers the exhaust manifold is provided, and as the temperature adjusting material, the cover member has a temperature adjustment in which the thermal conductivity of the portion corresponding to the high temperature portion of the exhaust manifold is higher than the portion corresponding to the low temperature portion of the exhaust manifold. The engine exhaust structure according to claim 1, wherein the materials are provided in a laminated form.   The cover member which covers the said exhaust manifold is provided, and the thermal radiation material was coated on the outer surface of the site | part corresponding to the high temperature site | part of the exhaust manifold of the cover member as the said temperature adjustment material. Engine exhaust structure.   The cover member which covers the said exhaust manifold is provided, The heat transfer material with high heat conductivity was provided in the laminated form between the cover member and the high temperature part of the exhaust manifold as the said temperature adjustment material. The engine exhaust structure described in the section.   The cover member which covers the said exhaust manifold is provided, and the heat insulating material was provided in the laminated | stacked form in the site | part corresponding to the low-temperature site | part of a cover member and an exhaust manifold as the said temperature adjustment material. Engine exhaust structure.   A cover member that covers the exhaust manifold is provided, and the thermal conductivity of the portion corresponding to the high temperature portion of the exhaust manifold is set between the cover member and the exhaust manifold as the temperature adjusting material more than the portion corresponding to the low temperature portion of the exhaust manifold. The engine exhaust structure according to any one of claims 1 to 5, wherein the elevated temperature adjusting material is provided in a laminated form.   A part or all of the exhaust manifold is configured in a double structure composed of an inner member and an outer member, and the temperature adjusting material has a thermal conductivity between the inner member and the outer member at a high temperature portion of the exhaust manifold. The engine exhaust structure according to any one of claims 1 to 8, wherein high heat transfer materials are provided in a laminated form.   A part or all of the exhaust manifold is configured in a double structure composed of an inner member and an outer member, and a heat insulating material is laminated between the inner member and the outer member at the low temperature portion of the exhaust manifold as the temperature adjusting material. The engine exhaust structure according to any one of claims 1 to 9, wherein the engine exhaust structure is provided in a shape.   A part or all of the exhaust manifold is configured in a double structure composed of an inner member and an outer member, and as the temperature adjusting material, the thermal conductivity of the high temperature portion of the exhaust manifold is set between the inner member and the outer member. The engine exhaust structure according to any one of claims 1 to 10, wherein a temperature adjusting material higher than the thermal conductivity of the low temperature portion is provided in a laminated form. The engine exhaust structure according to any one of claims 1 to 11, wherein the high-temperature portion of the exhaust manifold is a portion including at least a collecting portion.

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