JPH11236070A - Flange tightening structure for frp molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flange tightening structure for an FRP molding which can provide an excellent watertightness. SOLUTION: In the flange tightening structure, when flanges 11, 21 each comprising an FRP molding are joined to each other through an adhesive or a seal material and clamped together by a bolt 40 to make a tank, protruding strips 12, 13 or protrusions are provided on the flange joint surface of at least one of the flanges. The strips 12, 13 or the protrusions have different heights at the inner side and outer side of the tank respectively and the height thereof is made larger on the side of the tank (left side in the figure) where the gap between the flanges is larger. And a tank wall surface extends from the base part of one of the flanges along one of the tank inner wall surfaces and the extended tank wall and the other tank inner wall surface are joined to each other through an adhesive or a seal material. The forward ends of the upper and lower flanges are bent upwards so that a gap is formed therebetween and an adhesive or a seal material is filled into the gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flange fastening structure for an FRP molded product.

[0002]

2. Description of the Related Art Conventionally, flanges of FRP molded products are
A tank such as a septic tank is manufactured by joining with an adhesive or a sealing material and further tightening with a bolt.

In this case, in order to obtain good watertightness, a flange fastening structure has been proposed in which a ridge is provided around the flange joining surface or a portion near the bolt hole is slightly protruded from other portions (see FIG. 1). See JP-A-58-95266 and JP-A-58-140209.

[0004]

However, in the above-mentioned flange fastening structure, before the bolt is tightened,
If the gap between the inside of the tank and the outside of the tank on the flange joint surface is not equal, when tightening the bolts, the tank side with the larger gap between the inside and the outside of the tank should be more unevenly tightened. become.

As a result, stress concentrates at the root of the flange, that is, at the corner of the flange, and cracks are generated in the root of the flange and the tank wall near the root due to long-term use, and the watertightness of the tank is caused. May be impaired.

Even if the gap between the inside of the tank and the outside of the tank at the flange joining surface is equal, the strength of the root portion of the flange is relatively weak, and if a strong impact is applied to this portion or its vicinity, this will cause a problem. Cracks may occur in the root of the flange or in the tank wall near the root, and the watertightness of the tank may be impaired.

Furthermore, even if the gap between the inside of the tank and the outside of the tank at the flange joining surface is equal, air bubbles easily enter the adhesive or sealing material applied to the flange joining surface. In particular, when a concave portion is formed on the flange joining surface and an adhesive or a sealing material is held in the concave portion, the adhesive or the sealing material may not be held without a gap, and air bubbles easily enter. Therefore, a streak-like void (water supply) may be generated in the adhesive or the sealant at the joint portion, and the watertightness of the tank may be impaired. It is difficult to repair such streak-like voids later.

The present invention solves the above problems,
The purpose is to reduce the stress concentration on the root of the flange or to reinforce the root of the flange and its vicinity to prevent cracks from occurring at the root of the flange and the tank wall near it. It is an object of the present invention to provide a flange fastening structure for an FRP molded product, which can prevent the occurrence of watertightness for a long time.

Another object of the present invention is to provide a special structure for the flange joint, which may cause streak-like voids in the adhesive or sealing material applied to the flange joint surface or peel off. It is another object of the present invention to provide a flange fastening structure for an FRP molded product, which can obtain good watertightness over a long period of time.

[0010]

In order to achieve the above object, a flange fastening structure for an FRP molded product according to the first aspect of the present invention joins flanges of the FRP molded product via an adhesive or a sealing material. In the flange fastening structure when manufacturing the tank by tightening with a bolt, at least one flange joint surface is provided with a ridge or a ridge, the height of the ridge or ridge differs between the inside and outside of the tank. The configuration was such that the tank side where the gap between the flange joining surfaces was large was raised.

Further, in the flange fastening structure for an FRP molded product according to the second aspect of the present invention, the flanges of the FRP molded product are joined to each other via an adhesive or a sealing material and fastened with bolts to form a flange. In the structure, a tank wall is extended from one flange base along the other tank inner wall surface, and the extended tank wall and the other tank inner wall surface are joined via an adhesive or a sealing material. Configuration.

Further, the flange fastening structure for an FRP molded product according to the third aspect of the present invention is a method for manufacturing a tank by joining upper and lower flanges of an FRP molded product via an adhesive or a sealing material and fastening them with bolts. In the flange fastening structure,
The upper and lower flange tips are bent upward so as to form a gap therebetween, and the gap is filled with an adhesive or a sealing material.

According to the first aspect of the present invention, the height of the ridges or protrusions provided on the flange joining surface differs between the inside and the outside of the tank, and the height of the gap on the flange joining surface is increased on the tank side. Therefore, when the flange joint surface is bolted, even if the gap between the flange joint surface is different between the inside and outside of the tank, the gap is almost evenly tightened along the above ridges or protrusions, and the root of the flange Stress concentration on the part is reduced.

According to the second aspect of the present invention, the tank wall extending from the base of one flange along the inner wall surface of the other tank and the inner wall surface of the other tank are joined via an adhesive or a sealing material. Therefore, the extended tank wall reinforces the base of the flange and the tank wall in the vicinity thereof, and furthermore, the adhesive area by the adhesive or the sealing material increases, and the sealing property is improved.

According to the third aspect of the present invention, the upper and lower flange tips are bent upward so as to form a gap therebetween, and the gap is filled with an adhesive or a sealing material.
Since the gap is opened upward, air bubbles are less likely to stay in the adhesive or sealing material filled in such a gap, and even if the air bubbles are slightly staying, the force to peel off the flange joint surface When acts, the adhesive or sealing material filled in the gaps generates a force that presses them, thereby improving the sealing performance.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. First, a flange fastening structure for an FRP molded product according to the first aspect of the present invention will be described. FIG. 1 is a partially cutaway sectional view showing an example of a flange fastening structure for an FRP molded product according to the first aspect of the present invention.

In FIG. 1, reference numerals 10 and 20 denote a tank wall of a septic tank made of an FRP molded product, 11 denotes a flange of the tank wall 10,
21 is a flange of the tank wall 20. And flange 1
1 and the flange 21 are joined via an adhesive 30. As the adhesive 30, a structural adhesive such as a two-part urethane adhesive or a two-part epoxy adhesive is generally used.

A sealing material can be used in place of the adhesive 30. As the sealing material, a caulking material, a composition in which glass fiber is mixed with a polyurethane resin or a polyester resin, a punching material, an O-ring, butyl rubber, a foam, or the like is used.

Further, on the joint surface of one flange 11,
Two rail-shaped ridges 12, 13 are provided at appropriate intervals in the circumferential direction (length direction) of the flange 11. The number of the ridges may be one or three or more, but it is preferable to provide the two rail-shaped ridges 12 and 13 as described above. Further, the ridge may be provided on the joint surface between the two flanges 11 and 21.

The height of these ridges 12, 13 is different between the inside and the outside of the tanks 10, 20 in any of the ridges, the upper surface is formed as an inclined surface, and the gap between the flange joining surfaces is reduced. The larger tank side (left side in the drawing) is higher than the tank side with small gap (right side in the drawing). In this case, the average height (height at the center) of the ridges 12 and 13 is set to a desired height according to the gap between the flange joining surfaces.

Further, the flange joining surface is provided with a bolt 4
It is bolted by using a nut 41 and a nut 0. In this case, it is preferable that the bolts 40 be passed between the ridges 12 and 13 so that the flanges are uniformly tightened. Thus, the flange fastening structure of the FRP molded product according to the first aspect of the present invention is configured.

FIG. 2 is a partially cutaway sectional view showing another example of the flange fastening structure of the FRP molded product according to the first aspect of the present invention. In FIG. 2, reference numerals 10 and 20 denote tank walls of a septic tank made of an FRP molded product, 11 denotes a flange of the tank wall 10, and 21 denotes a flange of the tank wall 20. The flange 11 and the flange 21 are joined via an adhesive 30. A sealing material can be used instead of the adhesive 30.

Also, on the joint surface of one flange 11,
A plurality of cylindrical protrusions 14 are provided at appropriate intervals in the circumferential direction (length direction) of the flange 11. The protrusion 14 may be provided on the joint surface between the two flanges 11 and 21.

The height of these protrusions 14 is different between the inside and the outside of the tanks 10 and 20, and the upper surface thereof is inclined, and the gap between the flange joining surfaces is large. The tank side (right side in the drawing) is higher than the tank side (left side in the drawing) where the gap is small. In this case, bump 1
The average height (height at the center) of No. 4 is set to a desired height according to the gap between the flange joining surfaces.

Further, the flange joining surface is provided with a bolt 4
It is bolted by using a nut 41 and a nut 0. In this case, it is preferable that the bolts 40 be passed through the holes of the cylindrical protrusions 14 and fastened by bolts in order to equalize the fastening of the flanges. Thus, the flange fastening structure of the FRP molded product according to the first aspect of the present invention is configured.

According to the flange fastening structure of the FRP molded product shown in FIG. 1 or FIG. 2, the height of the ridges or protrusions provided on the flange joining surface is different between the inside and outside of the tank.
And since the gap side of the flange joining surface is made higher on the tank side, even if the gap of the flange joining surface is different between the inside and the outside of the tank when the flange joining surface is bolted, The gap is tightened almost evenly along the gap, so that stress concentration on the root of the flange is reduced.

As a result, even if used for a long time,
Cracks due to stress concentration do not occur on the root of the flange or on the tank wall near the root, and good watertightness can be obtained.

FIG. 3 is a partially cutaway sectional view showing an example of a flange fastening structure for an FRP molded product according to the second aspect of the present invention. In FIG. 3, reference numerals 10 and 20 denote a tank wall of a septic tank made of an FRP molded product, 11 denotes a flange of the tank wall 10, and 21 denotes a flange of the tank wall 20. The flange 11 and the flange 21 are joined via an adhesive 30. A sealing material can be used instead of the adhesive 30.

A tank wall 22 extends downward from the root of the one flange 21 along the inner wall surface of the other tank wall 10, and the extended tank wall 22 and the other tank wall 10 extend downward.
Are bonded to each other through an adhesive 31. A sealing material can be used instead of the adhesive 31.

Further, the flange joining surface is provided with a bolt 4
It is bolted by using a nut 41 and a nut 0. In this case, FIG. 1 or FIG.
May be provided. Thus,
A flange fastening structure for an FRP molded product according to the second aspect of the present invention is configured.

According to the flange fastening structure of the FRP molded product shown in FIG. 3 described above, the tank wall extending from the base of one flange along the inner wall surface of the other tank and the inner wall surface of the other tank are:
Since they are joined via an adhesive or a sealing material, the base of the flange or the surrounding tank wall is reinforced by the extended tank wall, and the bonding area by the adhesive or the sealing material is increased, The sealing performance is improved.

As a result, even if used for a long time,
Even if a strong impact is applied to the base of the flange or its vicinity,
Cracks do not occur in the root portion of the flange or in the vicinity of the tank wall, and good watertightness can be obtained.

FIG. 4 is a partially cutaway sectional view showing an example of a flange fastening structure for an FRP molded product according to the third aspect of the present invention. 4, reference numerals 10 and 20 denote a tank wall of a septic tank made of an FRP molded product, 11 denotes a flange of a lower tank wall 10,
1 is a flange of the upper tank wall 20. The lower flange 11 and the upper flange 21 are joined via an adhesive 30. A sealing material can be used instead of the adhesive 30.

The distal ends 15, 23 of the upper and lower flanges 11, 21 are bent substantially vertically upward so as to form a gap therebetween, and the gap is filled with an adhesive 31. A sealing material can be used instead of the adhesive 31.

Further, the flange joint surface is provided with a bolt 4
It is bolted by using a nut 41 and a nut 0. In this case, FIG. 1 or FIG.
May be provided. Thus,
According to the third aspect of the present invention, there is provided a flange fastening structure for an FRP molded product.

According to the FRP molded product flange fastening structure shown in FIG. 4, the upper and lower flange tips are bent upward so as to form a gap therebetween, and the gap is filled with an adhesive or a sealing material. Since the gap is opened upward, even if bubbles are generated in the adhesive or sealing material filled in such a gap, such bubbles naturally escape upward from the gap before being cured and stay there. It becomes difficult to form streaky voids (water supply), and the sealing property is improved.

Even if a small amount of air bubbles remain in the adhesive or the sealing material filled in the gap, the adhesive or the sealing material filled in the gap is applied to the adhesive or the sealing material when a force acts to peel the flange joint surface. Generates a force that presses it, thereby improving the sealing performance.

As a result, streaky voids may be formed in the adhesive or sealing material applied to the flange joining surface, or the adhesive or sealing material in this portion may be peeled off due to a strong force applied to the flange joining surface. Even so, good watertightness can be obtained over a long period of time by the adhesive or sealing material filled in the gap.

[0038]

As described above, according to the flange fastening structure of the FRP molded product of the present invention, the stress concentration on the root portion of the flange is alleviated or the root portion of the flange and the vicinity thereof are reinforced to thereby reduce the flange. This prevents cracks from being generated in the root of the tank and in the vicinity of the tank wall, and provides good watertightness over a long period of time.

In addition, by forming the flange joint portion with a special structure, even if a streak-like gap is formed or peels off in the adhesive or sealant applied to the flange joint surface, good watertightness can be obtained for a long period of time. Property is obtained.

Therefore, the flange fastening structure of the FRP molded product of the present invention is suitably used for a tank made of an FRP molded product requiring high strength and high water tightness, such as a septic tank or a water storage tank.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view showing an example of a flange fastening structure of an FRP molded product according to the first aspect of the present invention.

FIG. 2 is a partially cutaway sectional view showing another example of the flange fastening structure of the FRP molded product according to the invention of claim 1;

FIG. 3 is a partially cutaway sectional view showing an example of a flange fastening structure for an FRP molded product according to the invention of claim 2;

FIG. 4 is a partially cutaway sectional view showing an example of a flange fastening structure of an FRP molded product according to the invention of claim 3;

[Explanation of symbols]

 10, 20 Tank wall 11, 21 Flange 12, 13 Rail-shaped ridge 14 Cylindrical protrusion 15 Folded flange tip 22 Extended tank wall 23 Folded flange tip 30, 31 Adhesive or Seal material 40 Bolt 41 Nut

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 23:00

Claims (3)

[Claims] In a flange fastening structure for manufacturing a tank by joining flanges of an FRP molded product via an adhesive or a sealing material and fastening with bolts, at least one flange joining surface has a ridge or a ridge. A flange fastening structure for an FRP molded product, wherein the height of the ridges or protrusions is different between the inside and the outside of the tank, and the tank side where the gap between the flange joining surfaces is large is made higher. 2. A flange fastening structure for manufacturing a tank by joining flanges of FRP molded articles via an adhesive or a sealing material and fastening with bolts, along a wall surface of one of the flanges from the base of one of the flanges. A flange wall of an FRP molded product, wherein a wall of the tank is extended, and the extended wall of the tank and the other inner wall of the tank are joined via an adhesive or a sealant. 3. A flange fastening structure for manufacturing a tank by joining upper and lower flanges of an FRP molded product with each other via an adhesive or a sealing material and fastening with bolts so that a gap is formed between upper and lower flange tips. Characterized in that the gap is filled with an adhesive or a sealing material, and the gap is filled with an adhesive or a sealing material.