JP2009013971A - Exhaust manifold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust manifold capable of securing sufficient passage section area of a secondary air supply passage, compact and excellent in degree of freedom in design. <P>SOLUTION: In an exhaust manifold 1 having a secondary air supply passage 7 formed as one unit with a flange member 2 fastened to an internal combustion engine, the secondary air supply passage 7 comprises a groove 2d formed on the flange member 2 and a gutter shape cover member 6 fitted in the groove 2d. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust manifold provided with a secondary air supply passage.

  In order to purify exhaust gas discharged from an internal combustion engine, it is known to supply secondary air to the exhaust system. For example, when secondary air is supplied into the exhaust manifold in a state where the catalyst provided in the exhaust system is not sufficiently activated, such as during a cold start of the internal combustion engine, unburned components contained in the exhaust gas are removed. When burned, hydrocarbons and carbon monoxide are oxidized and reduced, and exhaust gas can be purified.

  As an exhaust manifold provided with a secondary air supply passage, for example, an exhaust manifold described in Patent Document 1 is known. In Patent Document 1, a groove (channel) is formed in an upper outer corner of the flange, and this groove is covered with an L-shaped cover plate from above, whereby a secondary air supply passage is formed integrally with the flange. A configuration is disclosed.

  However, in the exhaust manifold disclosed in Patent Document 1, when a sufficient cross-sectional area of the secondary air supply passage is ensured, if the groove is deeply formed or the width of the groove is increased, the flange becomes thicker or the flange becomes thicker. As a result, the outer shape of the flange becomes large, and there is a possibility that a problem of an increase in the weight of the flange and an increase in cost and a problem of an arrangement space between the flange and its peripheral parts in the engine room may occur. Further, since the secondary air supply passage is positioned at the upper outer corner of the flange, the degree of freedom in designing the secondary air supply passage is low.

Japanese Patent No. 3637463

  In view of the above problems, an object of the present invention is to provide an exhaust manifold that can sufficiently secure a passage cross-sectional area of a secondary air supply passage and is compact and excellent in design freedom.

  In order to solve the above problems, according to the invention of claim 1, in the exhaust manifold in which the secondary air supply passage is integrally formed with the flange member fastened to the internal combustion engine, the secondary air supply passage is a flange. It consists of a groove formed in the member and a hook-shaped cover member fitted into the groove.

  According to the present invention, since the secondary air supply passage is composed of a groove and a cover member fitted to the groove, a sufficient cross-sectional area of the secondary air supply passage can be secured, and the design is compact and excellent in design flexibility. Exhaust manifold can be provided.

  The best mode for carrying out the present invention will be described with reference to the drawings. 1 is a plan view showing an exhaust manifold according to the first embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along line AA in FIG. 1, FIG. 3 is an enlarged sectional view taken along line BB in FIG. FIG. 5 is an enlarged sectional view taken along the line CC in FIG. 1, FIG. 5 is an enlarged sectional view taken along the line AA in FIG. 1 of the exhaust manifold according to the second embodiment of the present invention, and FIG. FIG. 7 is an enlarged sectional view taken along line AA in FIG. 1 of the exhaust manifold according to FIG. 1, and FIG. 7 is an enlarged sectional view taken along line AA in FIG. 1 of the exhaust manifold according to the fourth embodiment of the present invention.

  1 to 4 show an exhaust manifold according to a first embodiment of the present invention. The exhaust manifold 1 includes a flange member (commonly referred to as a head flange) 2 having a plurality of openings 2a communicating with an exhaust port of a cylinder head of an internal combustion engine (not shown), an exhaust collecting portion 3 connected to the openings 2a, It has an exhaust gas purification device 4 such as a catalytic converter connected to the downstream end 3 a of the collecting portion 3, and a downstream flange member 5 connected to the downstream end 4 a of the exhaust gas purification device 4.

  A plurality of fastening holes 2b are formed through the flange member 2 for fastening the flange member 2 to a cylinder head (not shown) with bolts, nuts, or the like. Further, a supply hole 2c is formed in the vicinity of each of the plurality of openings 2a so as to supply secondary air in communication with an exhaust port (not shown). Then, a groove 2d having a concave cross section that communicates with all the supply holes 2c and meanders so as to avoid the openings 2a and the fastening holes 2b is formed on one surface (exhaust collecting portion 3 side) of the flange member 2 by cutting or the like. ing.

  And the secondary air supply channel | path 7 is formed by fitting the peripheral part 6a of the cover member 6 formed in the bowl-shaped cross section by press work etc. to the groove | channel 2d, and joining by welding W. As shown in FIG.

  A secondary air introduction pipe 8 is connected in the middle of the cover member 6, and a small flange member 9 is connected to the secondary air introduction pipe 8. The secondary air is sent from a secondary air supply source (not shown) connected to the small flange member 9 to the secondary air introduction pipe 8 and then distributed to each supply hole 2 c through the secondary air supply passage 7. Then, it is introduced into an exhaust port (not shown) through each supply hole 2c.

  According to the present embodiment, the sum of the passage cross-sectional area obtained by the cover member 6 formed in the bowl-shaped cross section and the passage cross-sectional area obtained by the groove 2d having the concave cross section is the passage cut-off of the secondary air supply passage 7. Since it becomes an area, the passage cross-sectional area of the secondary air supply passage can be sufficiently secured with a compact structure.

  Further, the groove 2d can freely form a groove path in any part of the flange member 2 as long as the opening 2a and the fastening hole 2b are avoided, and therefore, the design freedom of the secondary air supply passage 7 is free. The problem of the arrangement space between the secondary air supply passage and its peripheral parts in the engine room is eliminated.

  In addition, the secondary air supply passage 7 is formed by fitting the peripheral edge 6a of the cover member 6 into the groove 2d, so that the assembly accuracy, welding quality, rigidity, durability, etc. of the cover member 6 and the groove 2d are improved. improves.

  FIG. 5 shows a secondary air supply passage of the exhaust manifold according to the second embodiment of the present invention, and is an enlarged cross-sectional view taken along line AA of FIG. In addition, the same code | symbol is attached | subjected to the aspect same as 1st Embodiment, and the description is abbreviate | omitted.

  The peripheral edge portion 10a of the cover member 10 is bent inwardly of the cover member 10 and formed into a bowl shape. The peripheral edge portion 10a is fitted into the groove 2d and joined by welding W to supply secondary air. A passage 11 is formed.

  According to this embodiment, the same effect as the first embodiment can be obtained.

  6 shows a secondary air supply passage of an exhaust manifold according to the third embodiment of the present invention, and is an enlarged cross-sectional view taken along line AA of FIG. In addition, the same code | symbol is attached | subjected to the aspect same as 1st Embodiment, and the description is abbreviate | omitted.

  The peripheral edge portion 12a of the cover member 12 is bent outwardly from the cover member 10 and formed into a bowl shape, and the groove-like peripheral edge portion 12a is formed into a groove 2e formed to a depth substantially equal to the plate thickness. And the secondary air supply passage 13 is formed by being joined by welding W. In order to increase the cross-sectional area of the secondary air supply passage 13, the depth of the groove 2e may be formed to the same depth as in the first embodiment.

  According to this embodiment, the same effect as the first embodiment can be obtained.

  FIG. 7 shows a secondary air supply passage of an exhaust manifold according to the fourth embodiment of the present invention, and is an enlarged cross-sectional view taken along line AA of FIG. In addition, the same code | symbol is attached | subjected to the aspect same as 1st Embodiment, and the description is abbreviate | omitted.

  The cover member 14 is formed in a bowl-shaped cross section having a width X2 larger than the separation width X1 of the peripheral edge portion 14a. According to this embodiment, the passage cross-sectional area of the secondary air supply passage 15 can be ensured larger than the passage cross-sectional area of the secondary air supply passage 7 in the first embodiment.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, Even if there is a change of the range which does not deviate from the meaning of this invention, it is included in this invention. For example, the path, depth, and width of the groove may be arbitrarily set so that the secondary air is evenly distributed to the supply holes, and may be gradually deformed. Moreover, what is necessary is just to set suitably the cross-sectional shape of a cover member, and the shape of a peripheral part. In addition, the exhaust manifold of the above-described embodiment is connected to an in-line 3-cylinder or V-type 6-cylinder internal combustion engine. What is necessary is just to set the number of a part and a supply hole. Further, the exhaust gas purification device may be separate from the exhaust manifold, and a flange may be attached to each of the two, and the flanges may be connected using bolts, nuts, or the like.

The top view which shows the exhaust manifold which concerns on the 1st Embodiment of this invention AA line expanded sectional view in FIG. BB expanded sectional view in FIG. CC sectional enlarged view in FIG. The AA line expanded sectional view in Drawing 1 of an exhaust manifold concerning a 2nd embodiment of the present invention. FIG. 1 is an enlarged sectional view taken along line AA in FIG. 1 of an exhaust manifold according to a third embodiment of the present invention. FIG. 1 is an enlarged sectional view taken along line AA in FIG. 1 of an exhaust manifold according to a fourth embodiment of the present invention.

Explanation of symbols

1 Exhaust manifold 2 Flange member (head flange)
2a Opening 2b Fastening hole 2c Supply hole 2d, 2e Groove 3 Exhaust collecting part 4 Exhaust gas purification device (catalytic converter)
5 Downstream flange member 6, 10, 12, 14 Cover member 6a, 10a, 12a, 14a Peripheral portion 7, 11, 13, 15 Secondary air supply passage 8 Secondary air introduction pipe 9 Small flange member

Claims (1)

  In an exhaust manifold in which a secondary air supply passage is integrally formed with a flange member fastened to an internal combustion engine, the secondary air supply passage has a groove formed in the flange member, and a bowl shape fitted in the groove. An exhaust manifold comprising a cover member.

Images