JP6411102B2 - Fastening positioning structure - Google Patents

Description

  The present invention relates to a fastening positioning structure for fastening a plurality of parts having different degrees of expansion and contraction due to heat.

  An exhaust manifold (hereinafter abbreviated as “exhaust manifold”) provided in an engine for a vehicle circulates high-temperature combustion exhaust gas having a temperature of several hundred degrees Celsius along with the operation of the engine. In particular, when the engine is running at high speed, the exhaust gas passes at a pulsating pressure of several thousand cycles per minute, so heat and noise are dissipated and transmitted to the engine room and further to the outside of the vehicle.

  Such heat dissipation from the exhaust manifold may cause heat damage to various harnesses and ducts in the engine room. Therefore, in order to suppress the situation where heat and noise are radiated to the outside from a heat source such as an exhaust manifold or a noise source, various heat insulators (hereinafter referred to as insulators) as a protection device for the heat source and the noise source, particularly a thermal protection device. For short).

  When an insulator is provided on the exhaust manifold, it is necessary to fasten the exhaust manifold body and the insulator to each other. The insulator is different from the material of the exhaust manifold body, for example, in which a steel plate and a heat insulating material are laminated. For this reason, the temperature difference between the exhaust manifold main body and the insulator and the distortion due to the difference in the coefficient of thermal expansion occur, and the insulator is cracked.

  As a measure for preventing the occurrence of this crack, it is conceivable to avoid the problem by making the bolt hole of the fastening portion between the exhaust manifold and the insulator a long hole in a plan view and providing a gap in the direction of thermal expansion or contraction. However, when assembling the insulator on the exhaust manifold, positioning in the longitudinal direction in the long hole is difficult, and if the positioning in the longitudinal direction is mistaken, cracks will still occur.

  In order to position such a fastening part such as a bolt, it is conceivable to process the fastening part of the insulator or the exhaust manifold, or the bolt itself. For example, in cited document 1, a bolt hole with a small diameter is provided for positioning among a plurality of bolt holes.

Japanese Utility Model Publication No. 58-072513

  However, as described above, in the prior art in which the bolt holes for positioning are provided, the number of steps for forming the bolt holes for positioning is newly generated. In addition, parts such as exhaust manifolds and insulators that are affected by heat and that have a lot of vibrations are greatly deformed, and there are cases where the position where the bolt holes for positioning are provided is limited.

  The present invention has been made in view of the above points, and the object of the present invention is to provide a fastening technique for a plurality of parts that can be more accurately positioned and assembled and can absorb thermal deformation. is there.

  In the present application, in order to solve the above-described problem, by providing a throttle portion having a simple structure in the pilot hole of the fastening portion, accurate positioning and assembly are possible, and fastening positioning that can absorb thermal deformation is also possible. Invented the structure.

Specifically, in the first invention, a first part having a fastening portion and a long hole having a long diameter in the direction of expansion and contraction due to heat are formed, and the long hole is fastened to the fastening portion of the first part by a bolt. The elongated hole of the second component has a restricting portion for restricting movement from the fastening position of the bolt in the longitudinal direction, and the restricting portion in the oblong hole The diameter of the hole on the fastening position side in the longitudinal direction is equal to or greater than the shaft diameter of the bolt, the first part and the second part are made of metal, and the long hole has a fastening position at the end opposite to the extension direction. made has a hole portion, the diaphragm portion, on the outside than the engagement position of the shaft diameter direction of the bolt in a state of being abutted against the shaft of the bolt to the end of the extending direction opposite the conclude position partially are provided on both sides of a long hole so as to surround, the volume of a portion narrowed portion in the long hole is opposed, While that restricts movement of the bolt during thermal expansion, the movement of the bolt when the thermal expansion is configured to facilitate.

As described above, since the hole diameter on the side of the fastening position in the longitudinal direction from the throttle portion in the long hole is equal to or larger than the shaft diameter of the bolt, the bolt can be restricted from moving in the longitudinal direction from the fastening position. Accurate positioning at the time becomes possible. In addition, since the length of the portion of the elongated hole where the constricted portions face each other is set so as to be able to absorb thermal deformation, when the bolt moves in the longitudinal direction from the fastening position, the movement of the bolt The throttle part will not block. In addition, since the first component and the second component have metal ductility, the strain can be absorbed even if the strain is large. In addition, since the fastening portion extends in a certain direction due to heat, thermal expansion in the certain direction can be absorbed.

  According to a second aspect, in the first aspect, a part of the first component can be visually recognized from a gap between the inner wall of the long hole and the bolt fastened at the fastening position.

  According to this, positioning and assembling property can be improved.

In a third aspect based on the first aspect, the first part is an exhaust manifold, and the second part is a heat insulator.

  According to this, cracks can be prevented even for a component having a high temperature and a lot of vibration.

According to a fourth aspect of the present invention, in the first aspect of the present invention, an annular floating material is provided on each of the front and back surfaces of the second component and covers the periphery of the fastening position in the long hole.

  According to this, when the peripheral part of the long hole in the second part is fastened by the bolt, the annular floating material (buffer material) that is arranged on the front surface and the back surface of the second part and covers the periphery of the fastening position. Is interposed between the bolt, the first part, and the second part around the fastening position. That is, since the peripheral part of the long hole is fastened with a bolt across the annular floating material, the peripheral part of the long hole formed in the second component is easily rubbed during expansion or contraction due to heat. For this reason, the crack which arises in the peripheral part of a long hole can be suppressed.

In a fifth aspect based on the fourth aspect , the floating material is a suspension mesh made of fine metal wires.

  According to this, the floating material which has a desired characteristic can be obtained.

  According to the present invention, it is possible to realize a fastening positioning structure capable of more accurate positioning and assembly and capable of absorbing thermal deformation.

FIG. 1 is a schematic plan view showing an exhaust manifold that is an example of another component that is fastened to a component having a fastening positioning structure according to the first embodiment of the present invention. FIG. 2 is a plan view showing a heat insulator which is an example of a component having a fastening positioning structure according to the first embodiment of the present invention. FIG. 3 is a plan view showing the exhaust manifold and the heat insulator fastened to each other by the fastening positioning structure according to the first embodiment of the present invention. FIG. 4 is a plan view showing a fastening positioning structure according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing a fastening positioning structure according to the second embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or its application.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows an exhaust manifold (exhaust manifold 10) of a vehicle engine that is fastened to a component having a fastening positioning structure according to the present embodiment. FIG. 2 shows a heat insulator (insulator 20) which is a component having a fastening positioning structure according to the present embodiment.

  An insulator 20 shown in FIG. 2 includes oval bolt holes (long holes) 21A, 22A and 25A each having a fastening positioning structure according to the present invention, and a normal bolt hole 23C having a substantially perfect circle or oval shape. 24C is formed. The bolt holes 23C and 24C serve as base points when the insulator 20 is expanded and contracted by heat, and are located on the reference line A1 shown in FIG.

  For the insulator 20, for example, an iron plate (steel plate) or an aluminum plate can be used. The insulator 20 may have a single layer structure or a laminated structure of two or more layers.

  The exhaust manifold shown in FIG. 1 is provided with fastening portions 21B, 22B, 23B, 24B and 25B corresponding to the bolt holes 21A, 22A, 23C, 24C and 25A of the insulator 20, respectively. Here, each fastening part 21B-25B is represented typically, and the bracket etc. which fasten a bolt are omitted. FIG. 3 shows a state where the insulator 20 is fastened to the exhaust manifold 10 with a plurality of bolts. For the exhaust manifold 10, for example, stainless steel can be used.

  In FIG. 2, an arrow A <b> 2 indicating the extending direction of each fastening portion 21 </ b> B, 22 </ b> B, and 25 </ b> B of the exhaust manifold 10 is added. Here, as an example, each arrow A2 is substantially perpendicular to the reference line A1, and is directed away from the reference line A1.

  As a modification, the plurality of bolt holes 21A, 22A, and 25A may be provided so that the respective longitudinal axes are not located on the same plane. If it does in this way, each bolt hole 21A, 22A, and 25A can absorb this distortion according to distortion by heat in each fastening part 21B, 22B, and 25B. Moreover, the distortion which arises in fastening part 21B, 22B, and 25B can be offset by matching the longitudinal direction of each bolt hole 21A, 22A, and 25A with the distortion direction by a heat | fever.

  As a modification, the plurality of bolt holes 21A, 22A, and 25A holes may be provided so that the respective axes in the longitudinal direction are not parallel to each other. If it does in this way, this distortion can be absorbed according to distortion by heat in fastening parts 21B, 22B, and 25B. Moreover, if the longitudinal direction of each bolt hole 21A, 22A, and 25A is matched with the distortion direction by heat, the distortion which arises in fastening part 21B, 22B, and 25B can be offset.

  FIG. 4 shows a planar configuration of the bolt hole 21A having the fastening positioning structure according to the present embodiment. As shown in FIG. 4, the bolt hole 21 </ b> A is provided with a pair of constricted portions (constriction portions) 21 a at the opposing peripheral edge portions. Similarly, the other bolt holes 22A and 25A are respectively provided with throttle portions 21a.

  The major axis of the oval bolt hole 21A is set along the extension direction A2. Further, the narrowed portion 21a of the bolt hole 21A is provided so as to be shifted from the center of the long axis toward the extending direction A2. That is, the narrowed portion 21a is provided so as to surround the bolt fastening position 21b. Accordingly, the diameter of the bolt hole 21A on the side of the fastening position 21b in the longitudinal direction from the narrowed portion 21a is set to be equal to or larger than the shaft diameter of the bolt. In addition, the length of the portion of the long hole where the narrowed portions 21a face each other is calculated and set based on the material of the insulator 20 and the thickness thereof so that thermal deformation can be absorbed.

  In the present embodiment, as an example, the shaft diameter of the bolt is 14.2 mm, the diameter of the fastening position 21b is 16.8 mm, and the amount of displacement of the throttle portion 21a toward the A2 direction is 2.0 mm. In addition, the minimum width of the portion of the bolt hole 21A where the narrowed portions 21a face each other is, for example, 13.7 mm. The volume of each throttle portion 21a is such that when the exhaust manifold 10 and the insulator 20 are assembled, the movement of the bolt can be reliably prevented, and the bolt can be easily moved when expanded by heat, that is, easily deformed. Set to degree.

-Effect-
As described above, according to the present embodiment, when the hole diameter on the side of the fastening position 21b in the longitudinal direction from the narrowed portion 21a in the bolt hole 21A or the like which is a long hole is equal to or larger than the shaft diameter of the bolt, the bolt is removed from the fastening position 21b. Since movement in the longitudinal direction can be restricted, accurate positioning during assembly is possible. In addition, since the length of the portion of the long hole where the narrowed portions 21a face each other is set so as to absorb thermal deformation, when the bolt moves in the longitudinal direction from the fastening position 21b, the bolt Is not blocked by the throttle portion 21a.

(Second Embodiment)
The present embodiment is different from the first embodiment in the configuration in which the floating material is provided in the peripheral portion of each elongated hole such as the bolt hole 21A, but the other configurations are the same as those in the first embodiment. is there. Therefore, in the following description, the same components as those of the first embodiment will be described using the same reference numerals.

  FIG. 5 shows a cross-sectional structure in a state in which the floating material 30 supported by the annular collar 32 is disposed at the peripheral portion of the bolt hole 21 </ b> A of the insulator 20. The floating material 30 is a suspension mesh formed by compressing a thin metal wire in an annular shape, and makes a pair of contact with the upper and lower surfaces of the peripheral edge of the bolt hole 21A. The collar 32 is made of, for example, steel, and supports each floating material 30 by a flange (flange) projecting vertically from the upper end and the lower end of the bolt hole 32a.

  A bracket 40 is disposed at a fastening portion 21B of the exhaust manifold 10 (not shown), and a collar 32 that supports the floating material 30 sandwiched between the peripheral portions of the bolt holes 21A includes a nut 42 welded to the lower surface of the bracket, Fastened with bolts 41. At this time, the arrangement position of the insulator 20 with respect to the bolt hole 21A in the collar 32 is the fastening position 21b shown in FIG.

  In FIG. 5, as an example, a configuration in which the floating material 30 supported by the collar 32 is provided in the bolt hole 21A is shown, but the collar 32 is similarly applied to the other bolt holes 22A and 25A which are long holes. Floating material 30 supported by is provided.

  As described above, in the second embodiment, the floating material 30 supported by the collar 32 is disposed at the peripheral portions of the bolt holes 21A, 22A, and 25A, so that vibration from the exhaust manifold 10 is absorbed. Can do.

  In addition, when the peripheral portions of the bolt holes 21A, 22A and 25A in the insulator 20 are fastened by the bolts 41, the annular floating material 30 covering the periphery of the fastening position 21b is formed around the fastening position 21b. 20 and the exhaust manifold 10. That is, since the peripheral portions of the bolt holes 21A, 22A, and 25A are fastened by the bolts 41 with the annular floating material 30 interposed therebetween, the heat at the peripheral portions of the bolt holes 21A, 22A, and 25A formed in the insulator 20 Friction during expansion or contraction is facilitated. For this reason, the crack which arises in the peripheral part of each bolt hole 21A, 22A, and 25A can be suppressed easily and reliably.

  In the first embodiment and the second embodiment, the exhaust manifold 10 and the insulator 20 are used as the components to be fastened to each other. However, the present invention is not limited to this. The present invention can also be applied to other exhaust system parts or parts including a catalyst that require fastening.

  The fastening positioning structure according to the present invention can be applied to applications that require compatibility between positioning and assembly of parts having different degrees of expansion and contraction due to temperature and prevention of cracks at fastening positions of a plurality of parts.

10 Exhaust manifold (exhaust manifold) (first part)
20 Heat insulator (insulator) (second part)
21A Bolt hole (long hole)
21a Restriction part 21b Fastening position 22A Bolt hole (long hole)
23C Bolt hole 24C Bolt hole 25A Bolt hole (long hole)
21B, 22B, 23B, 24B, 25B Fastening part 30 Floating material 32 Collar 32a Bolt hole 40 Bracket 41 Bolt 42 Nut

Claims (5)

A first part having a fastening portion;
In a fastening positioning structure including a long hole having a long diameter in the direction of expansion and contraction due to heat, and the second part fastened to the fastening portion of the first part by a bolt.
The elongated hole of the second component has a throttle portion that restricts movement from the fastening position of the bolt in the longitudinal direction;
The hole diameter at the fastening position side in the longitudinal direction from the throttle portion in the long hole is equal to or larger than the shaft diameter of the bolt,
The first part and the second part are made of metal,
The elongated hole has a hole portion serving as a fastening position at an end portion opposite to the extending direction,
The diaphragm portion is outside than the fastening position of the shaft diameter direction of the bolt in a state of being abutted against the axis of the bolt to the end of the extending direction opposite, enclosing the concluding position partially Are provided on both sides of the slot,
The volume of the portion of the elongated hole facing the constricted portion is set so as to restrict the movement of the bolt during non-thermal expansion while facilitating the movement of the bolt during thermal expansion. Fastening positioning structure. The fastening positioning structure according to claim 1,
A fastening positioning structure, wherein a part of the first component can be visually recognized from a gap between an inner wall of the elongated hole and the bolt fastened to the fastening position. The fastening positioning structure according to claim 1 or 2,
The first part is an exhaust manifold of a vehicle engine;
The fastening positioning structure, wherein the second part is a heat insulator of the exhaust manifold. In the fastening positioning structure according to any one of claims 1 to 3,
The fastening positioning structure further comprising an annular floating material that is disposed on each of the front and back surfaces of the second component and covers the periphery of the fastening position in the long hole. The fastening positioning structure according to claim 4,
The fastening positioning structure, wherein the floating material is a suspension mesh made of a thin metal wire.

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