JP4417201B2 - Apparatus for mounting exhaust system parts in an internal combustion engine - Google Patents

Description

  In the internal combustion engine, an exhaust system component in which exhaust gas flows inside, such as an exhaust manifold or an exhaust gas purifier, is attached to the mounting surface extending vertically such as a side surface of the cylinder head. The present invention relates to an apparatus for mounting with a plurality of bolts provided on the surface so as to protrude from the surface and nuts screwed to the bolts.

  2. Description of the Related Art Conventionally, in an internal combustion engine, when the exhaust manifold is attached to a vertically extending attachment surface such as a side surface of a cylinder head in the internal combustion engine, the attachment surface is described as described in Patent Document 1. Provided with a plurality of bolts protruding from the mounting surface at appropriate intervals, and the exhaust manifold protrudes from the mounting surface into a plurality of bolt holes formed in the flange portion of the exhaust manifold. In general, the mounting structure is such that after each bolt is fitted and fitted, a nut is screwed onto the tip of each bolt and the nut is tightened.

  In this exhaust manifold mounting structure, for example, as described in Patent Document 2, the inner diameter dimension of the bolt hole into which each bolt is fitted is considerably larger than the outer diameter dimension of the bolt, By providing a considerably large gap between the bolt hole and the bolt fitted therein, the thermal expansion is allowed when the exhaust manifold rises to a high temperature.

As another prior art, Patent Document 3 discloses that when the flange portion is attached to the attachment surface with a bolt protruding from the attachment surface and a nut screwed to the bolt, the bolt is attached to the flange portion. By integrally providing on the inner peripheral surface of the bolt hole to be fitted, a thin portion that is elastically deformed and engages with a screw thread in the bolt when the bolt is fitted into the bolt hole. It is described that the state in which the flange portion is mounted on the mounting surface is held only until the nut is screwed onto the tip of the bolt.
Japanese Utility Model Publication No. 63-25311 JP 2002-195031 A Japanese Utility Model Publication No. 4-106006

  However, as in the conventional case, the exhaust manifold is made up of a plurality of bolts protruding from the mounting surface and a nut screwed to the mounting surface that extends vertically such as the side surface of the cylinder head. In the case of mounting, the inner diameter dimension of the bolt hole through which each bolt is inserted is configured to be larger than the outer diameter of the bolt in order to allow thermal expansion, When the exhaust manifold is mounted on the mounting surface so that the bolts projecting from the mounting surface fit into the bolt holes in the flange portion of the exhaust manifold, the exhaust manifold is locked to the bolts. Will be dropped from the mounting surface until the nut is screwed onto the tip of each bolt.

  In other words, the exhaust manifold is attached to the mounting surface with one hand in the state where the exhaust manifold is mounted so that the bolt protruding from the mounting surface fits into the bolt hole. Since the nuts must be screwed into the bolts with the other hand while being held in place, there is a problem that the mounting work is troublesome and the workability is low.

  It is considered that this problem can be solved by providing a thin-walled portion that is elastically deformed as disclosed in Patent Document 3 in the bolt hole in the exhaust manifold.

  However, in a general internal combustion engine, the exhaust manifold is made of cast iron and is manufactured by casting. Therefore, in order to provide a thin-walled portion that is elastically deformed in the bolt hole in the exhaust manifold, this thin-walled portion that is elastically deformed is provided. Must be manufactured as a separate component from the exhaust manifold and mounted on the cast exhaust manifold, which complicates the structure and greatly increases the manufacturing cost. In addition, even when the exhaust manifold is attached, the elastically deformed thin wall portion is engaged with the screw thread of the bolt, so that it becomes difficult to remove the exhaust manifold from its mounting surface. , Which significantly impedes the tolerance for thermal expansion.

  It is a technical object of the present invention to provide an attachment device that solves these problems.

In order to achieve this technical problem, claim 1 of the present invention provides:
“Exhaust system parts in which exhaust gas flows in an internal combustion engine, with respect to a vertically extending mounting surface, a plurality of bolts provided on the mounting surface so as to fit into bolt holes in the exhaust system parts; , In a mounting device that is attached with a nut screwed to the tip of each bolt,
At the base of at least one of the bolts on the mounting surface, a screwless part having an outer diameter equal to or larger than the outer diameter of the male screw of the one bolt is provided, while the exhaust system component The bolt hole into which the one bolt is fitted is made into an inner diameter to be fitted into the unthreaded portion, and the inner surface of the bolt hole is engaged with the male screw of the single bolt. Engrave the thread groove to be. "
It is characterized by that.

Further, claim 2 of the present invention is
“In the first aspect of the present invention, the pitch of the thread groove on the inner surface of the one bolt hole is equal to the pitch of the male screw on the one bolt, and the depth of the thread groove on the inner surface of the one bolt hole. The height is made lower than the height of the thread in the male thread of the one bolt. "

  In the configuration described in claim 1, exhaust system parts are mounted on a plurality of vertically extending mounting surfaces so that bolts are fitted into bolt holes in the exhaust system parts. In this case, the thread groove provided on the inner surface of the bolt hole into which the one bolt is fitted is engaged with the male screw of one of the bolts.

  By this engagement, the exhaust system component can be securely held in a state where it is mounted on the mounting surface, so that the operator can release his hand from the exhaust system component in this state.

  Next, a nut is screwed to the tip of each bolt, and one bolt hole fitted in the one bolt among the bolt holes in the exhaust system parts is replaced with a screw-free portion in the one bolt base. Since the thread groove on the inner surface of the bolt hole engages with the male screw in the single bolt, the nut is tightened in this state. An exhaust system component can be attached to the mounting surface.

  In other words, according to the present invention, when the exhaust system component is mounted on the mounting surface extending vertically, the exhaust system component mounted on the mounting surface can be securely held by the bolt protruding from the mounting surface. Therefore, it is not necessary to support the exhaust system parts by hand until the nuts are screwed onto the bolts, so that the exhaust system parts are attached to the mounting surface extending vertically. Thus, the workability when mounting the exhaust system parts in a state allowing thermal expansion can be greatly improved.

  According to a second aspect of the present invention, the pitch of the thread groove on the inner surface of the one bolt hole is equal to the pitch of the male thread on the one bolt, and the thread groove on the inner surface of the one bolt hole. By making the depth of the thread lower than the height of the ridge in the male screw of the single bolt, the depth when the thread groove on the inner surface of the bolt hole is engaged with the male screw in the single bolt is made shallow. Therefore, the one bolt hole is moved from the state in which the thread groove on the inner surface thereof is engaged with the male screw in the one bolt to the state in which it is fitted into the unthreaded portion of the base portion of the one bolt. It becomes easy to do and can improve the workability of installation.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 to 7 show a first embodiment.

  In the first embodiment, an exhaust system is provided with respect to a vertically or substantially vertically extending side surface 3 in a cylinder head 2 of a multi-cylinder internal combustion engine 1 having four cylinders A1, A2, A3, and A4. This is a case where an exhaust manifold 4 made of cast iron, which is one of the parts, is attached.

  That is, of the four cylinders, an exhaust port 5 from the first cylinder A1, an exhaust port 6 from the second cylinder A2, an exhaust port 7 from the third cylinder A3, and An exhaust port 8 from the fourth cylinder A4 is opened.

  A stat bolt 9, 10, 11, 12 is screwed to each of the upper portions of the side surfaces 3 in the exhaust ports 5, 6, 7, 8 so as to protrude vertically from the side surface 3. Yes.

  In addition, stat bolts 13 and 14 protrude vertically from the side surface 3 in the lower portions of the side surface 3 of the exhaust port 5 in the first cylinder and the exhaust port 8 in the fourth cylinder. It is screwed.

  Furthermore, tap holes 17 for screwing head bolts 15 and 16 are respectively formed in the lower portions of the side surface 3 of the exhaust port 6 in the second cylinder and the exhaust port 7 in the third cylinder. 18 is drilled.

  On the other hand, in the exhaust manifold 4, the branch pipes 19, 20, 21, 22 communicating with the exhaust ports 5, 6, 7, 8 are vertically attached to mounting flanges 19 a, 19 b, 20 a, 20 b, 21 a. , 21b, 22a, and 22b are integrally provided, and the flange bolts 19a, 19b, 20a, 20b, 21a, 21b, 22a, and 22b are connected to the respective stat bolts 9, 10, 11, 12, 13, and 14 respectively. Further, bolt holes 19a ', 19b', 20a ', 20b', 21a ', 21b', 22a ', 22b', in which the head bolts 15, 16 are fitted, are respectively drilled.

  The exhaust manifold 4 is fastened to the side surface of the cylinder head 2 by the nuts 23 screwed to the respective stat bolts 9, 10, 11, 12, 13, and 14 and screwed to the tap holes 17 and 18. It is configured to be attached by fastening with the bolts with heads 15 and 16 combined.

  A sealing gasket 24 is sandwiched between the side surface 3 and the exhaust manifold 4 attached thereto.

  Then, in the second cylinder A2 and the third cylinder A3 located in the center among the respective stat bolts 9, 10, 11, 12, 13, and 14, both stat bolts 10 and 11 (hereinafter, referred to as the upper ends of the branch pipes 20 and 21). (Referred to as a stat bolt located at the center on the upper side), the outer diameter of the root bolt to the side surface 3 is equal to or larger than the outer diameter d of the male screws 10a, 11a of the stat bolt 10, 11. On the other hand, the screw-less portion 25 is provided with d1 and the bolt holes 20a 'and 21a' into which both the stat bolts 10 and 11 located in the center of the upper side pass are fitted to the screw-less portion 25. The inner diameter D can be fitted with an appropriate gap between the outer peripheral surface of the non-existing portion 25, and the inner surface of the bolt holes 20a 'and 21a' is formed on the upper center. To engraved thread groove 26 that the pitch P1 is equal to the pitch P of the external thread at both stud bolt 10, 11 to location.

  In this case, the depth S of the thread groove 26 on the inner surface of the bolt holes 20a ', 21a' is, for example, approximately half of the height H of the threads on the male threads of the stat bolts 10, 11. The dimension is set to be lower than the height H of the thread in the male screw of both the stat bolts 10 and 11, so that the portion between the thread grooves 26 is configured as a flat surface without a thread.

  On the other hand, among the bolt holes 19a ', 19b', 20a ', 20b', 21a ', 21b', 22a ', 22b', the static bolts 9, 12 excluding the static bolts 10, 11 located at the upper center. , 13, 14 and the bolt holes 19a ', 19b', 20b ', 21b', 22a ', 22b' into which the double-headed bolts 15, 16 are fitted, are respectively connected to the stat bolts 9, 12, 13, 14 In addition, the inner diameter D0 is larger than the outer diameter d0 of the male screw in the double-headed bolts 15 and 16 by an amount allowing thermal expansion in the exhaust manifold 3.

  In this configuration, when attaching the exhaust manifold 4 to the side surface 3 extending vertically in the cylinder head 2, an operator first shows the exhaust manifold 4 by a two-dot chain line in FIGS. 5 and 6. Further, the respective stud bolts 9, 10, 11, 12, 13, 14 protruding from the side surface 3 are respectively connected to the bolt holes 19 a ′, 20 a ′, 21 a ′, 22 a ′, 19 b ′, 20 b ′, 21 b in the exhaust manifold 4. ′ And 22b ′ are installed so as to penetrate therethrough.

  As a result, the two stat bolts 10, 11 are connected to the male screws 10a, 11a of the two stat bolts 10, 11 located in the upper center of the stat bolts 9, 10, 11, 12, 13, 14 respectively. The threaded grooves 26 on the inner surfaces of the bolt holes 20a 'and 21a' that are fitted through are engaged so as to be screwed together.

  By this engagement, the exhaust manifold 4 can be securely held in a state where it is mounted on the side surface 3 of the cylinder head 2, so that the operator can release his hand from the exhaust manifold 4 in this state.

  Next, the operator screws the nuts 23 into the tips of the respective stat bolts 9, 10, 11, 12, 13, 14, while screwing the head bolts 15, 16 into the tap holes 17, 18 in the side surface 3. The bolt holes 20a 'and 21a' fitted into the two stat bolts 10 and 11 located at the upper center of the exhaust manifold 4 are connected to the base portions of the two stat bolts 10 and 11, respectively. The thread groove 26 in the inner surface of the bolt holes 20a 'and 21a' is engaged with the male screws 10a and 11a of the two stat bolts 10 and 11 In this state, the nuts 23 and the double-headed bolts 15 and 16 are strongly tightened, whereby the exhaust manifold 4 is It can be attached to the side 3 of the cylinder head 2.

  In this attached state, the respective stat bolts 9, 10, 11, 12, 13, 14 and the headed bolts 15, 16 and their bolt holes 19a ', 20a', 21a ', 22a', 19b ', 20b', Since there is a gap between 21b 'and 22b', thermal expansion in the exhaust manifold 4 can be allowed.

  Next, FIG. 8 shows a second embodiment.

  In the second embodiment, the threadless portion 25 'is provided integrally on the side surface 3 side of the cylinder head 2 instead of being provided on the stat bolts 10 and 11. Even in this case, the outer diameter d1 of the unthreaded portion 25 'is set to an outer diameter d1 larger than the outer diameter d of the male screws 10a and 11a in the stat bolts 10 and 11, while both the stat bolts 10 and 11 penetrate. The inner diameter D of the bolt holes 20a 'and 21a' to be inserted with an appropriate gap between the unthreaded portion 25 'and the outer peripheral surface of the unthreaded portion 25'. Thus, a thread groove 26 'is provided on the inner surface at the same or substantially the same pitch as the male threads 10a and 11a.

  Even with this configuration, the same effect as in the first embodiment can be obtained, but in the case of the second embodiment, the bolt provided with the unthreaded portion 25 'is as follows: Without being limited to the stat bolt, it is possible to use a bolt provided with a male screw over its entire length.

  Further, in this second embodiment, instead of providing the unthreaded portion 25 'integrally with the side surface 3 of the cylinder head 2, the unthreaded portion is separated from the stat bolt and the cylinder head. The ring body can be configured to be fitted to a stat bolt or a cylinder head.

  By the way, in each of the above-described embodiments, the threadless portion 25 is provided on the two stud bolts 10 and 11 located in the center on the upper side of the respective stud bolts 9, 10, 11, 12, 13 and 14. In the case where the screw groove 26 is provided in the inner surface of the bolt holes 20a 'and 21a' through which the two stat bolts 10 and 11 are inserted, at least in any part of the stat bolts located on the upper side. The threadless portion 25 may be provided on one stat bolt, while the thread groove may be provided on the inner surface of the bolt hole through which the one stat bolt is inserted.

  In the above-described embodiments, the cylinder head 2 has the side surface 3 extending vertically as an attachment surface, and the exhaust manifold 4 is attached to the attachment surface. However, the present invention is not limited to this. The exhaust gas outlet pipe 4a in the exhaust manifold 4 is horizontally oriented, and the flange surface of the outlet pipe 4a is a mounting surface extending vertically, and an exhaust gas purifier or an exhaust turbocharger is mounted on the mounting surface. Or, when installing exhaust system parts such as exhaust pipes, or mounting the exhaust gas outlet pipe in the exhaust gas purifier or the exhaust turbocharger horizontally and horizontally so that the flange surface of the outlet pipe extends vertically Of course, this can also be applied to the mounting surface when exhaust system parts such as exhaust pipes are installed. As described above, when the exhaust system part is attached to the flange surface as a vertically extending mounting surface, the mounting bolt is replaced with the flange, instead of using a stat bolt as in the embodiment. Head bolts inserted from the back side of the can be used.

It is a top view which shows 1st Embodiment. It is the side surface of FIG. FIG. 3 is an enlarged sectional view taken along line III-III in FIG. 2. FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 2. It is a figure which shows the state which decomposed | disassembled of FIG. It is a figure which shows the state which decomposed | disassembled of FIG. It is an enlarged view of the principal part. It is a principal part enlarged view which shows 2nd Embodiment.

Explanation of symbols

1 Internal combustion engine 2 Cylinder head 3 Side surface (mounting surface)
4 Exhaust manifold (exhaust system parts)
5, 6, 7, 8 Exhaust port 9, 10, 11, 12, 13, 14 Stat bolt 15, 16 Head bolt 19a ', 19b', 20a ', 20b' Bolt hole 21a ', 21b', 22a ', 22b 'Bolt hole 23 Nut 24 Gasket 25, 25' Unthreaded part 26, 26 'Thread groove

Claims (2)

A plurality of bolts provided to project an exhaust system part through which exhaust gas in an internal combustion engine flows vertically to a mounting surface extending vertically, so as to fit into a bolt hole in the exhaust system part; In a mounting device that is mounted with a nut that is screwed to the tip of each bolt,
At the base of at least one of the bolts on the mounting surface, a screwless part having an outer diameter equal to or larger than the outer diameter of the male screw of the one bolt is provided, while the exhaust system component The bolt hole into which the one bolt is fitted is made an inner diameter to be fitted into the unthreaded portion, and the inner surface of the bolt hole is engaged with the male screw of the one bolt. A mounting device for exhaust system parts in an internal combustion engine, wherein a thread groove is formed.   In Claim 1, the pitch of the thread groove on the inner surface of the one bolt hole is equal to the pitch of the male thread on the one bolt, and the depth of the thread groove on the inner surface of the one bolt hole. The exhaust system component mounting apparatus in an internal combustion engine is characterized in that is lower than the height of the ridge in the male screw of the one bolt.

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