JP3974991B2 - Resin member fastening structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fastening structure of a resin member for fastening a resin member to a member to be fastened with a bolt.
[0002]
[Prior art]
Such a fastening structure for resin members is already known from Japanese Utility Model Publication No. 7-35753 and Japanese Utility Model Publication No. 60-32409. JP-A-7-35753 discloses a resin-made intake manifold with a bolt with an excessive fastening force by using a stepped bolt when a bolt is connected to an engine cylinder head with a bolt. The intake manifold is prevented from being damaged. In addition, what is described in the Japanese Utility Model Publication No. 60-32409 described above is that when a resin head cover or timing belt cover is connected to an engine body with a bolt, a bolt is attached to a metal collar embedded in the mounting flange of the resin member. By inserting and screwing into the engine body, the fastening force of the bolt is supported by a metal collar to prevent damage to the mounting flange.
[0003]
[Problems to be solved by the invention]
By the way, it is inevitable that resin members are deformed such as sink marks and warps during molding. For this reason, the pitch between the bolt holes of the resin member matches the pitch between the bolt holes on the fastening member side. It may disappear. If the resin member is joined to the member to be fastened in such a state, the inner peripheral surface of the bolt hole is strongly damaged by the outer peripheral surface of the bolt, and the torque required to tighten the bolt increases. There is a possibility that a fastening failure may occur. Further, when a metal collar is used, it is necessary to remove the metal collar when recycling the resin member, which causes a problem that the recyclability is greatly reduced.
[0004]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to accurately connect a member to be fastened without damaging the resin member and to ensure the recyclability of the resin member.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is characterized in that a bolt penetrating a mounting flange of a resin member is screwed into a screw hole formed in a member to be fastened. In the fastening structure of the resin member that presses the pressing surface of the mounting flange with the flat seat surface and fastens the coupling surface of the mounting flange to the coupling surface of the fastened member, the mounting flange is moved from the pressing surface side to the coupling surface side. The bolt has a taper portion that has an axial dimension corresponding to the thickness of the mounting flange and is fitted to the taper hole, and is connected to the taper portion. A screw portion that is screwed into the screw hole, and the taper portion has a flat end of the bolt head that protrudes radially outward from one end of the taper portion and contacts the pressing surface of the mounting flange. Continuous seating surface And also a small diameter side end of the tapered portion, between the threaded portion formed on the smaller diameter than the other end, the stepped portion in contact with the mounting surface of the fastening member is formed, resin An annular rib protrudes from the inner peripheral surface of the tapered hole of the member .
[0006]
According to the above configuration, since the taper portion of the bolt that fits into the taper hole of the mounting flange has an axial dimension corresponding to the thickness of the mounting flange, the fastening force of the bolt that acts around the taper hole The resin mounting flange can be prevented from being damaged, and the conventional metal collar need not be embedded in the mounting flange, so that the resin member can be easily recycled. Even if the position of the taper hole is shifted due to deformation of the mounting flange, the position of the taper hole is corrected by contact with the taper portion of the bolt. Therefore, the deformation of the mounting flange can be corrected without damaging the taper hole. The manufactured member can be correctly coupled to the fastened member. Further, when the taper portion of the bolt is inserted into the taper hole of the mounting flange, the small diameter portion of the taper portion may be fitted into the large diameter portion of the taper hole, so that the insertion can be easily performed.
[0007]
Further, when the screw portion of the bolt is screwed into the screw hole of the member to be fastened, the end surface of the other end of the taper portion (the step formed between the screw portion) abuts on the coupling surface of the member to be fastened and the bolt Therefore, the mounting flange and the elastic seal member of the resin member are compressed with a predetermined fastening force determined by the axial dimension of the tapered portion. Therefore, without a metal collar fitted to the outer periphery of the bolt embedded in the mounting flange of the resin member can be coupled to the member to be fastened to the resin member with a constant fastening force, made of resin with excess fastening force It is possible to reliably prevent the mounting flange from being damaged . Furthermore, since the outer peripheral surface of the tapered portion abuts against the rib on the inner peripheral surface of the tapered hole to reduce the contact area, the bolt tightening load or the nut tightening load on the stud bolt can be reduced.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on reference examples shown in the accompanying drawings and examples of the present invention.
[0009]
1 to 3 show a reference example, FIG. 1 is a cross-sectional view of the main part of the engine, FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1, and FIG. It is.
[0010]
As shown in FIG. 1, an in-line four-cylinder engine E includes a cylinder block 1 and a cylinder head 2 that are coupled together. Four cylinders 3 are formed in the cylinder block 1, and a piston 4 is slidably fitted to each cylinder 3. An intake port 6 and an exhaust port 7 connected to the combustion chamber 5 are formed in the cylinder head 2. An intake port 8 connecting the intake port 6 to the combustion chamber 5 is opened and closed by an intake valve 9, and the exhaust port 7 is opened. An exhaust port 10 connected to the combustion chamber 5 is opened and closed by an exhaust valve 11. A camshaft 14, a rocker shaft 15, and an intake rocker arm 17 that is pivotally supported by the rocker shaft 15 and driven by an intake cam 16 inside a valve operating chamber 13 defined by the upper portion of the cylinder head 2 and the head cover 12. And an exhaust rocker arm 19 pivotally supported by the rocker shaft 15 and driven by the exhaust cam 18 is housed.
[0011]
2 and 3 together, it is clear that the coupling surface 23 formed on the mounting flange 22 of the resin intake manifold 21 is made of rubber or foam on the coupling surface 20 of the cylinder head 2 made of aluminum alloy. It couple | bonds through the plate-shaped elastic sealing member 24 formed with rubber | gum. The intake manifold 21 has four intake passages 25 corresponding to the four cylinders 3. Each intake passage 25 is connected to the coupling surface 20 through an opening 26 formed in the elastic seal member 24. It communicates with the intake port 6 that opens.
[0012]
A total of three tapered holes 27 are formed in the lower end of both ends and the upper center of the mounting flange 22 of the intake manifold 21, and three bolts 28 penetrating these tapered holes 27 are formed in the cylinder head 2. By screwing into the three screw holes 2 ₁ ..., The cylinder head 2 and the intake manifold 21 are integrally coupled while the elastic seal member 24 is sandwiched between the coupling surfaces 20 and 23.
[0013]
Each tapered hole 27 formed in the mounting flange 22 is reduced in diameter from the pressing surface 29 side to the coupling surface 23 side of the mounting flange 22. Each bolt 28 includes a head 30 with a seat having a flat seat surface, a tapered portion 31 having one end on the large diameter side continuous with the flat seat surface of the head 30, and a step on the other end on the small diameter side of the taper portion 31. And a flat seating surface of the bolt head 30 abuts against the pressing surface 29 of the mounting flange 22, and the taper portion 31 is the tapered hole of the mounting flange 22. fitted to 27, the threaded portion 32 is screwed into the screw hole 2 ₁ a cylinder head 2. The axial dimension L of the tapered portion 31 of the bolt 28 is a value obtained by subtracting a predetermined tightening allowance from the sum of the thickness of the mounting flange 22 and the thickness of the elastic seal member 24 to the dimension corresponding to the thickness of the mounting flange 22. Set to
[0014]
The cylinder head 2 constitutes the fastened member of the present invention, and the intake manifold 21 constitutes the resin member of the present invention.
[0015]
Thus, when the mounting flange 22 of the intake manifold 21 is coupled to the cylinder head 2 with the three bolts 28..., Both surfaces of the elastic seal member 24 are connected to the coupling surface 20 of the cylinder head 2 and the coupling surface 23 of the mounting flange 22. The intake ports 6 of the cylinder head 2 communicate with the intake passages 25 of the intake manifold 21 through the openings 26 of the elastic seal member 24.
[0016]
When the threaded portion 32 of bolt 28 screwed into the threaded hole 2 ₁ a cylinder head 2, (stepped portion formed between the words tapered portion 31 and the other end and a threaded portion 32) the end face of the tapered portion 31 is the cylinder head Since the screwing amount of the bolt 28 is restricted by contacting the two coupling surfaces 20, the mounting flange 22 and the elastic seal member 24 of the intake manifold 21 have a predetermined fastening force determined by the axial dimension L of the tapered portion 31. It is compressed with. Accordingly, the intake manifold 21 can be coupled to the cylinder head 2 with a constant fastening force without embedding a metal collar fitted to the outer periphery of the bolt 28 in the mounting flange 22 of the intake manifold 21, and an excessive fastening force can be used. It is possible to reliably prevent the resin mounting flange 22 from being damaged. In this manner, the intake manifold 21 can be coupled with a constant fastening force without using a metal collar, so that it is not necessary to remove the metal collar from the mounting flange 22 when the resin material of the intake manifold 21 is reused. Recyclability is greatly improved.
[0017]
By the way, since sinks and warps accompanying injection molding occur in the resin intake manifold 21, the pitch between the three tapered holes 27 formed in the mounting flange 22 changes with respect to the design value. There is a case. In such a case, since the three taper holes 27 of the mounting flange 22 are displaced with respect to the three screw holes 2 ₁ of the cylinder head 2, the bolts 28 interfere with the taper holes 27. There is a possibility that it cannot be screwed in smoothly.
However, according to the present reference example, the taper portions 27 of the bolts 28 are pressed to guide the taper holes 27 to the correct position, thereby correcting the distortion of the mounting flange 22 and fixing the mounting flange 22 to the cylinder head. 2 can be accurately combined. At this time, the load in the direction perpendicular to the axis acting on the mounting flange 22 from the bolts 28 is smoothly transmitted from the tapered portions 31 to the tapered holes 27, so that the tapered holes 27 are damaged by local loads. There is nothing wrong. Further, when the bolts 28 are inserted, the small diameter portion of the taper portion 31 only needs to be fitted to the large diameter portion of the taper hole 27, so that the bolt 28 can be easily moved even if the position of the taper hole 27 is greatly displaced. Can be inserted.
[0018]
Further, as in the modified example of FIG. 4 with respect to the reference example , if the annular groove 22 ₁ is formed on the coupling surface 23 of the mounting flange 22 so as to surround the outer periphery of each tapered hole 27, the fastening force of the bolt 28 The distortion of the mounting flange 22 can be easily corrected, and the coupling surface 23 can be uniformly adhered to the elastic seal member 24.
[0019]
Further, the as modification of FIG. 5 with respect to reference example, formed by utilizing a dead space generated in the small-diameter portion of the tapered hole 27 of mounting flange 22, a cooling water passage 22 _2, 22 ₂ for flowing a cooling water can do.
[0020]
6 shows the real施例of the present invention. This embodiment is obtained by projecting ribs 27 _first annular contactable to the tapered portion 31 of the inner peripheral surface bolt 28 of the tapered hole 27 of mounting flange 22, other configurations are the same as reference example is there. Therefore, even if the position of the taper hole 27 is greatly displaced when the bolt 28 is screwed, the taper portion 31 and the rib 27 ₁ come into contact with each other in a small area, so the bolt 28 can be screwed with a small torque. It becomes.
[0021]
As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.
[0022]
For example, in the embodiment, the coupling portion between the cylinder head 2 and the intake manifold 21 is illustrated, but the present invention can also be applied to the coupling portion of other members. In the embodiment, a plate-like elastic seal member 24 is interposed between the cylinder head 2 and the intake manifold 21, but an annular seal member such as an O-ring is used instead of the plate-like elastic seal member 24. The sealing member may not be interposed.
[0023]
【The invention's effect】
As described above, according to the present invention, since the taper portion of the bolt fitted into the taper hole of the mounting flange has an axial dimension corresponding to the thickness of the mounting flange, it acts on the periphery of the taper hole. The fastening force of the bolt can be suppressed to prevent the resin mounting flange from being damaged, and the resin member can be easily recycled because it is not necessary to embed a conventional metal collar in the mounting flange. Even if the position of the taper hole is shifted due to deformation of the mounting flange, the position of the taper hole is corrected by contact with the taper portion of the bolt. Therefore, the deformation of the mounting flange can be corrected without damaging the taper hole. The manufactured member can be correctly coupled to the fastened member. Further, when the taper portion of the bolt is inserted into the taper hole of the mounting flange, the small diameter portion of the taper portion may be fitted into the large diameter portion of the taper hole, so that the insertion can be easily performed.
[0024]
Also, when screwed a threaded portion of the bolt into the threaded hole of the fastening member, because the end face of the tapered portion abuts bolt screwing amount is regulated to the coupling surface of the workpieces, the mounting of the resin member The flange and the elastic seal member are compressed with a predetermined fastening force determined by the axial dimension of the tapered portion. Therefore, without a metal collar fitted to the outer periphery of the bolt embedded in the mounting flange of the resin member can be coupled to the member to be fastened to the resin member with a constant fastening force, made of resin with excess fastening force It is possible to reliably prevent the mounting flange from being damaged.
[0025]
In particular, since the outer peripheral surface of the tapered portion abuts against the rib on the inner peripheral surface of the tapered hole to reduce the contact area, it is possible to reduce the bolt tightening load or the nut tightening load on the stud bolt.
[Brief description of the drawings]
[1] line 3-3 enlarged sectional view of a main part sectional view of an engine according to a reference example FIG. 2 2-2 taken along line of FIG. 1 FIG. 3 FIG. 2 FIG. 4 of Reference Example Figure 5 shows showing a modification according to the actual施例of Figure 6 the present invention showing another variation of the reference example, FIG. [description of reference numerals] corresponding to FIG. 3
2 Cylinder head (fastened member)
2 ₁ Screw hole 20 Bonding surface 21 Intake manifold (resin member)
22 Mounting flange 23 Coupling surface 27 Tapered hole 27 ₁ Rib 28 Bolt 29 Pressing surface 30 Head portion 31 Tapered portion 32 Screw portion L Axial dimension

Claims (1)

By screwing a bolt (28) passing through the mounting flange (22) of the resin member (21) into a screw hole (2 ₁ ) formed in the fastened member (2), the head of the bolt (28) A resin member that presses the pressing surface (29) of the mounting flange (22) with (30) and fastens the coupling surface (23) of the mounting flange (22) to the coupling surface (20) of the fastened member (2). In the fastening structure of
The mounting flange (22) includes a tapered hole (27) whose diameter decreases from the pressing surface (29) side toward the coupling surface (23) side, and the bolt (28) has a thickness of the mounting flange (22). A taper portion (31) having a corresponding axial dimension (L) and fitted in the taper hole (27), and provided to be continuous with the taper portion (31), is formed in the screw hole (2 ₁ ). A screw portion (32) to be screwed, and protrudes radially outward from one end of the tapered portion (31) on the large-diameter side to a pressing surface (29) of the mounting flange (22). The flat bearing surface of the bolt head (30) in contact is continuous, the other end on the small diameter side of the taper portion (31), and the screw portion (32) formed to have a smaller diameter than the other end. In between, the step part which contact | abuts to the attachment surface (20) of the said to-be-fastened member (2) Made is, the tapered hole (27) inner peripheral surface an annular rib (27 ₁₎ is characterized in that it is projecting, fastening structure of the resin member.

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