JP2017115950A - Fixing structure of flange - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of cracking along a weld line.SOLUTION: A fixing structure for fastening and fixing a flange 10 made of synthetic resin, to a mating member in a plate thickness direction by using a bolt 2, is provided. A bolt boss portion 12 provided with a cylindrical metallic collar to insert the bolt 2, is disposed near an outer edge of the flange 10. A dimension L1 in a reference plate thickness direction of the bolt boss portion 12 is determined to be slightly larger than a dimension L2 in a plate thickness direction of the collar so that the bolt boss portion 12 is pressed, and crush-deformed in the plate thickness direction by a seating surface 5 of the bolt 2 in fastening the bolt 2. The bolt boss portion 12 is provided with a projecting portion 16 projecting outward into the circular arc shape from an outer edge of a general portion of the flange 10. The projecting portion 16 has a recessed portion 20A recessed in the plate thickness direction to suppress crush deformation.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an improvement in a flange fixing structure in which a synthetic resin flange is fastened and fixed to a mating member using a bolt.

  As described in Patent Document 1, for example, a flange of a synthetic resin intake manifold of an internal combustion engine is fastened and fixed to a cylinder head, which is a counterpart member, using bolts. In such a flange fixing structure, a metal collar is attached to the bolt boss portion of the flange so as to ensure a predetermined bolt axial force without causing damage to the synthetic resin flange, and when tightening the bolt, the bolt boss The plate thickness direction dimension of the bolt boss portion is set to be slightly larger than the plate thickness direction size of the collar so that the portion is pressed in the plate thickness direction by the seat surface of the bolt to cause a certain degree of crushing deformation. Such crushing deformation prevents backlash of the flange and ensures sealing performance of the meshing portion of the bolt.

JP 2014-196789 A

  In a layout in which the bolt boss portion is located in the vicinity of the outer edge of the flange, the bolt boss portion may be provided with an overhang portion that protrudes in an arc shape (cylindrical shape) outward from the outer edge of the general portion of the flange. In such a structure in which the overhanging portion is provided, when the flange is molded, the synthetic resin material wraps around from both sides and merges at the overhanging portion, and a weld line (weld line) is generated in the merged portion. Sometimes. For this reason, when the bolt boss portion is crushed and deformed when the bolt is fastened, if a stress is generated in the overhang portion in the vicinity of the weld line, there is a risk of causing a problem such as a crack occurring along the weld line. In particular, there is a concern that the overhanging portion may be damaged when heat and humidity are applied, and when a snow melting agent (calcium chloride) adheres.

  The present invention has been made paying attention to such a situation, and the bolt boss portion has a projecting portion projecting in an arc shape outward from the outer edge of the general portion of the flange. It is an object of the present invention to provide a novel flange fixing structure capable of suppressing the occurrence of damage such as cracks in the portion.

  The present invention relates to a flange fixing structure in which a synthetic resin flange is fastened and fixed in a plate thickness direction to a mating member using bolts. In the vicinity of the outer edge of the flange, a bolt boss portion to which a cylindrical metal collar into which the bolt is inserted is attached is provided. When tightening the bolt, the plate thickness direction dimension of the bolt boss portion is set larger than the plate thickness direction size of the collar so that the bolt boss portion is pressed in the plate thickness direction by the seat surface of the bolt and deformed. ing. The bolt boss portion is provided with an overhang portion that projects outward in an arc shape from the outer edge of the general portion of the flange where the bolt boss portion is not provided. And the recessed part recessed in the said plate | board thickness direction is formed in this overhang | projection part so that the said crushing deformation may be suppressed.

  By providing such a concave portion, it is possible to suppress crushing deformation in the overhang portion, relieve stress, and suppress the occurrence of cracks or the like in the overhang portion.

  Preferably, the concave portion is formed in a range centering on a weld line along a protruding direction of the protruding portion. As a result, it is possible to suppress crushing deformation particularly in the vicinity of the weld line, and to effectively suppress the occurrence of cracks along the weld line.

  The recess may be formed on the seating surface side of the overhanging portion where the seating surface of the bolt is seated, or may be formed on the counterpart member side of the overhanging portion where the seating surface of the bolt is not seated. good.

  According to the present invention, the bolt boss portion has a structure having an overhang portion projecting in an arc shape outward from the outer edge of the general portion of the flange, while suppressing the deformation of the overhang portion during bolt fastening, Generation | occurrence | production of the crack etc. of a protruding part, especially the part along a weld line can be suppressed, and the durability and reliability of a flange can be improved.

The top view which shows an example of the flange of the intake manifold which concerns on this invention. The top view which expands and shows the area | region A of FIG. The top view which shows the principal part of the flange which concerns on 1st Example of this invention. Sectional drawing which shows the state at the time of the bolt fastening of the flange of the said 1st Example. Sectional drawing which shows the state after the bolt fastening of the flange of the said 1st Example. The top view which shows the principal part of the flange which concerns on 2nd Example of this invention. Sectional drawing which shows the state at the time of the bolt fastening of the flange of the said 2nd Example. Sectional drawing which shows the state after the bolt fastening of the flange of the said 2nd Example. The top view which shows the principal part of the flange which concerns on 3rd Example of this invention. Sectional drawing which shows the state at the time of the bolt fastening of the flange of the said 3rd Example. Sectional drawing which shows the state after the bolt fastening of the flange of the said 3rd Example. The top view which shows the principal part of the flange which concerns on 4th Example of this invention. Sectional drawing which shows the state at the time of the bolt fastening of the flange of the said 4th Example. Sectional drawing which shows the state after the bolt fastening of the flange of the said 4th Example. The top view which shows the principal part of the flange which concerns on 5th Example of this invention. Sectional drawing which shows the state at the time of the bolt fastening of the flange of the said 5th Example. Sectional drawing which shows the state after the bolt fastening of the flange of the said 5th Example. The top view which shows the principal part of the flange which concerns on 6th Example of this invention. Sectional drawing which shows the state at the time of bolt fastening of the flange of the said 6th Example. Sectional drawing which shows the state after the bolt fastening of the flange of the said 6th Example.

  Hereinafter, an embodiment in which the fixing structure according to the present invention is applied to a flange of a synthetic resin intake manifold of an internal combustion engine will be described in detail with reference to the drawings.

  1 to 5 show the fixing structure of the flange 10 according to the first embodiment of the present invention. The flange 10 is applied to a portion where the intake manifold of the internal combustion engine is fastened and fixed to the mounting surface 1A of the cylinder head 1 which is a counterpart member by using bolts 2. For example, the flange 10 is formed integrally with the intake manifold. Alternatively, it is formed as a separate body from the intake manifold. In the flange 10, four intake passages 11 connected to the intake ports 1 </ b> B of the four cylinders opened on the mounting surface 1 </ b> A of the cylinder head 1 are formed side by side in the cylinder row direction.

  The bolt 2 is provided with a head 4 at one end of a shaft 3 having a male screw formed on the outer periphery, and a disc-shaped washer 6 having a seating surface 5 is integrally provided below the head 4. The washer 6 may be configured separately from the bolt 2.

  The flange 10 is fastened and fixed in the plate thickness direction to the mounting surface 1 </ b> A of the cylinder head 1 using a plurality of (two in this example) bolts 2. In the vicinity of the outer edge of the flange 10, bolt boss portions 12 are provided at five locations. A cylindrical metal collar 13 is attached to each bolt boss portion 12.

  As shown in FIG. 4, when the bolt is fastened, the collar 13 is press-fitted (inserted) into the bolt boss portion 12 of the flange 10, and then the bolt 2 is inserted inside the collar 13 to thereby insert the tip of the shaft portion 3 of the bolt 2. The flange 10 is fastened and fixed to the cylinder head 1 by the bolt 2 as shown in FIG. 5 by screwing the side into a bolt hole 1 </ b> C formed in the cylinder head 1 and tightening the bolt 2.

  Here, the bolt boss portion 12 of the synthetic resin flange 10 is pressed in the plate thickness direction by the seat surface 5 of the bolt 2 to cause a certain degree of crushing deformation, so that a reference plate thickness direction dimension L1 (described later) of the bolt boss portion 12 is generated. The dimension of the portion where the recess 20A is not provided) is set slightly larger than the thickness L2 of the collar 13 in the plate thickness direction. Such crushing deformation prevents the flange 10 from rattling after the bolt is fastened, and also ensures the sealing performance of the screw meshing portion of the bolt 2.

  Of the five bolt boss portions 12 shown in FIG. 1, the upper three bolt boss portions 12 in FIG. 1 are particularly provided with the outer edge 15 of the general portion 14 of the flange 10 where the bolt boss portions 12 are not provided, as shown in FIG. On the other hand, a projecting portion 16 is provided which projects outwardly in a circular arc shape (semi-cylindrical shape). Therefore, when the flange 10 is molded, as shown by the arrow B in FIG. 2, the synthetic resin material flows into the overhanging portion 16 so as to wrap around from both sides of the cylindrical portion. A weld line 18 (weld line) is formed along the overhang direction 17. In addition, although the weld line 18 may appear on a line on the surface, it may not be visible without appearing on the surface.

  Therefore, when the bolt boss portion 12 is crushed and deformed when the bolt is tightened, if the stress is generated in the overhang portion 16 in the vicinity of the weld line 18, the overhang portion 16 may be damaged, for example, a crack may be generated along the weld line 18. is there. In particular, there is a concern that the overhang 16 may be damaged when heat and humidity are applied, and when a snow melting agent (calcium chloride) adheres.

  Therefore, in this embodiment, the overhanging portion 16 is formed with a concave portion 20A that is recessed in the thickness direction so as to suppress crushing deformation. In this first embodiment, the recess 20A is recessed on the flat seating surface 19 side on which the seating surface 5 of the bolt 2 is seated, and a fan-shaped circumferential direction centering on the weld line 18 along the overhang direction 17 It is recessed over the range. The plate thickness direction dimension L3 of the bolt boss portion 12 where the recess 20A is formed is shorter than the reference plate thickness direction dimension L1 of the portion where the recess 20A is not formed, and the recess 20A is seated on the bolt 2 when the bolt is fastened. The collar 13 is set slightly shorter than the dimension L2 in the plate thickness direction so as not to be crushed and deformed by being pressed by the surface 5.

  Therefore, when the bolt 2 is fastened, the concave portion 20A formed in the range centered on the weld line 18 is not pressed against the seating surface 5 of the bolt 2, and the deformation is greatly reduced or eliminated. Therefore, damage to the overhang portion 16 including a crack along the weld line 18 can be reliably suppressed.

  In addition, in most of the remaining portions of the bolt boss portion 12 around the collar 13 except the recess 20A, the reference plate thickness direction dimension L1 is larger than the plate thickness direction dimension L2 of the collar 13. Is ensured, and rattling of the flange 10 can be suppressed.

  Moreover, since the recessed part 20A is provided in the seating surface 19 side which is pressed by the seating surface 5 of the volt | bolt 2 among the both sides | surfaces of the plate | board thickness direction of the volt | bolt boss part 12 and produces crushing deformation, crushing deformation is suppressed more reliably. Or it can be solved.

  Here, if the thickness direction dimension L3 of the portion where the recess 20A is provided is at least shorter than the reference thickness direction dimension L1, it is possible to suppress crushing deformation near the weld line 18 and to suppress the occurrence of cracks and the like. it can. Therefore, in the above embodiment, the thickness direction dimension L3 of the portion where the recess 20A is provided is shorter than the thickness direction dimension L2 of the collar 13, but it is equal to or slightly longer than the collar 13. In this case, since the crushing margin of the bolt boss portion 12 is ensured over the entire periphery of the collar 13 including the recess 20A, the sealing performance can be improved.

  The recess 20A may be formed at the same time as the molding, or may be formed after the molding by cutting.

  In the following embodiments, the same constituent elements as those in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

  6 to 8 show a second embodiment. In the second embodiment, the concave portion 20B provided in the overhanging portion 16 of the bolt boss portion 12 is provided only in the inner peripheral side portion facing the seat surface 5 (washer 6). It is different from the embodiment. That is, the recess 20B is recessed on the seating surface 19 side as in the first embodiment, and is recessed over a fan-shaped circumferential range centering on the weld line 18 along the overhang direction 17. However, it is formed only in a portion near the inner periphery facing the seat surface 5. That is, the flat seating surface 19 that is one step higher than the recess 20B remains in the portion on the outer peripheral side of the recess 20B. Even in the second embodiment, the same effects as those of the first embodiment can be obtained, and the flat seating surface 19 of the bolt boss portion 12 is left on the entire outer periphery. Good sealing performance.

  9 to 11 show a third embodiment. In the third embodiment, the range in which the recess 20C is formed is different from that of the first embodiment. That is, in the third embodiment, as shown in FIG. 9, the recess 20 </ b> C is formed over a range closer to the projecting direction than the straight line 21 orthogonal to the projecting direction 17 as viewed from the plate thickness direction. In the third embodiment, the same effects as in the first embodiment can be obtained, and when the recessed portion 20C after molding is formed by cutting, the processing becomes easy.

  12 to 14 show a fourth embodiment. In the first to third embodiments, the recesses 20A to 20C are formed in a stepped shape so as to be a flat surface parallel to the seating surface 19, but in this fourth embodiment, the recess 20D is formed on the seating surface 19. On the other hand, it is formed obliquely. Specifically, the recess 20D is configured as a flat inclined surface so as to become lower toward the outer peripheral side of the bolt boss portion 12, that is, the thickness direction dimension becomes smaller toward the outer peripheral side. It is connected to the seating surface 19 on the circumferential side. Further, the recess 20D is formed in a range centering on the overhanging direction 17, and in the fourth embodiment, a part of the seating surface 19 also remains in a portion closer to the inner peripheral side along the weld line 18. Thus, it is formed in a relatively narrow range.

  In the fourth embodiment as well, the same effects as those of the first embodiment can be obtained, and when the recess 20D after molding is formed by cutting, the processing becomes easy. Further, a part of the seating surface 19 remains on the inner peripheral side portion along the weld line 18, and a crushing margin is secured over the entire circumference around the collar 13, so that the sealing performance is improved.

  15 to 17 show a fifth embodiment. In the fifth embodiment, the recess 20E is formed over a wider range than in the fourth embodiment. Specifically, as shown in FIG. 15, the recess 20 </ b> E is perpendicular to the projecting direction 17 through a semicircular arc-shaped range centered on the projecting direction 17, that is, the center of the bolt boss portion 12 as viewed from the plate thickness direction. It is formed over a range closer to the overhang direction 17 than the line 22 to be formed. Similar to the fourth embodiment, the recess 20E is configured as a flat inclined surface whose dimension in the plate thickness direction becomes smaller toward the outer peripheral side.

  In the fifth embodiment, the concave portion 20E is enlarged as compared with the fourth embodiment, so that the sealing performance and the assembly stability of the flange 10 are slightly reduced, but the cracks along the weld line 18 occur. Can be more reliably suppressed.

  18 to 20 show a sixth embodiment. In the first to fifth embodiments, the recesses 20A to 20E are formed on the side of the seating surface 19 that faces the seating surface 5 of the bolt 2, but in this sixth embodiment, the seating surface 5 of the bolt 2 is seated. A recess 20F is provided on the side of the cylinder head 1 side (the counterpart member side) that is not to be used. Similar to the fourth and fifth embodiments, the concave portion 20F is an inclined surface whose dimension in the plate thickness direction becomes shorter toward the outer peripheral side, and as in the first embodiment, the projecting direction 17 is the center. It is formed in a fan-shaped range.

  Thus, also in the sixth embodiment in which the concave portion 20F is provided on the side surface on the cylinder head side, at the time of bolt fastening, the side surface of the overhanging portion 16 of the portion where the concave portion 20F is provided and the cylinder head 1 opposite to the side surface. Since a gap is left between the side surface and the side surface, crushing deformation is suppressed, and the occurrence of cracks and the like in the portion along the weld line 18 can be suppressed as in the first to fifth embodiments described above.

  As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above-described embodiments, and includes various modifications and changes. For example, although the present invention is applied to the flange of a synthetic resin intake manifold in the above embodiment, the present invention can be similarly applied to a flange fixing structure of another resin component such as a head cover.

1 ... Cylinder head (mating member)
2 ... Bolt 5 ... Seat surface 10 ... Flange 12 ... Bolt boss portion 13 ... Collar 14 ... General portion 15 ... Outer edge 16 ... Overhang portion 17 ... Overhang direction 18 ... Weld line 19 ... Seating surfaces 20A-20F ... Recess

Claims (4)

In the flange fixing structure that fastens and fixes the synthetic resin flange in the plate thickness direction to the mating member using bolts,
In the vicinity of the outer edge of the flange, a bolt boss portion to which a cylindrical metal collar through which the bolt is inserted is attached is provided.
When tightening the bolt, the plate thickness direction dimension of the bolt boss portion is set larger than the plate thickness direction size of the collar so that the bolt boss portion is pressed in the plate thickness direction by the seat surface of the bolt and deformed. ,
And the said bolt boss part has the overhang | projection part which protruded in the circular arc shape outward rather than the outer edge of the general part in which the said bolt boss part of the said flange is not provided,
A flange fixing structure characterized in that a recess recessed in the plate thickness direction is formed in the overhanging portion so as to suppress the crushing deformation.   The flange fixing structure according to claim 1, wherein the concave portion is formed in a range centering on a weld line along a protruding direction of the protruding portion.   The flange fixing structure according to claim 1 or 2, wherein the recess is formed on a seating surface side of the overhanging portion on which a seat surface of the bolt is seated.   The flange fixing structure according to claim 1 or 2, wherein the concave portion is formed on a counterpart member side of the overhanging portion where a seating surface of the bolt is not seated.

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