JPS627850Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a washer-integrated screw for waterproofing that maintains airtightness, particularly watertightness.

Conventionally, washer assembly screws for waterproofing are used in parts that require airtightness, especially watertightness, in vending machines, refrigerators, washing machines, etc., such as the one shown in Figure 1. . This washer built-in screw 13 is composed of a screw 1 and a washer 4. The screw 1 consists of a head 2 and a threaded portion 3. The threaded portion 3 is configured to be longer than the plate thickness of the mating member 11. Moreover, a washer 4 made of resin is incorporated into the screw 1 to ensure waterproofing between the washer-integrated screw 13 and the mating member 11.

The mating member 11 fastened by the washer assembly screw 13 consists of an upper plate member 8 and a lower plate member 9. A prepared hole 10 having a diameter larger than the outer diameter of the threaded portion 3 is bored in the upper plate member 8 . Further, the lower plate material 9 is provided with a pre-threaded hole 7 having a diameter smaller than the outer diameter of the threaded portion 3.

The mating material 11 is attached by the washer assembly screw 13 mentioned above.
When fastening, first, the threaded portion 3 of the screw 1 is screwed into the prepared screw hole 7 of the lower plate 9 through the prepared hole 10 of the upper plate 8. After that, the threaded part 3
penetrates the lower plate 9. Then, the screw 1 tightens the upper plate material 8 and the lower plate material 9 via the washer 4. At that time, the head seat surface 5 of the head 2 applies a compressive load to the washer 4. This washi 4
Due to the load, the head seat surface 5 and the washer 4 come into close contact, the washer 4 and the upper plate 8 come into close contact, and further, the upper board 8 and the lower plate 9 come into close contact.

As a result, the washer built-in screw 13 and the mating material 1
1, watertightness is maintained. Therefore, the washer set-in screw 13 has attracted attention from the industry as a screw for waterproofing the space between the washer set-in screw 13 and the mating material 11.

However, as shown in FIG. 2, the thread 12 of the threaded portion 3 is originally formed to have a lead angle. Therefore, when fastening the mating material 11 with the washer-integrated screw 13, unless the threaded portion 3 is inserted into the screw pilot hole 7 of the lower plate material 9 and the threaded portion 3 is screwed vertically, the The threaded portion 3 is inclined obliquely along the lead angle, and the mating material 11
screwed into. In particular, because the alignment between the pilot hole 10 of the upper plate material 8 and the screw pilot hole 7 of the lower plate material 9 is insufficient, a part of the upper plate material 8 blocks a part of the screw pilot hole 7. If so, the threaded portion 3 is screwed into the mating member 11 in an obliquely inclined state regardless of the lead angle. Then, the head seat surface 5
is inclined obliquely with respect to the upper surface of the washer 4, and when fastened, a gap R having a certain inclination is created between the head seat surface 5 and the washer 4. As a result, external moisture flows in through the above-mentioned gap R, and this moisture corrodes the space between the washers built-in screw and the mating material, or brings moisture into the interior of a product that requires watertightness. .

Therefore, in order to eliminate the above drawbacks, methods such as using adhesive between the washer built-in screw and the mating material have been adopted, but this adhesive is extremely expensive and increases the cost. However, there are still no definitive countermeasures for the above-mentioned drawbacks, and a complete solution has not yet been achieved.

The present invention aims to eliminate the above-mentioned drawbacks, and embodiments will be described below based on the drawings.

In FIG. 3, FIG. 5, and FIG. 6, 13 is a washer-integrated screw, which is composed of the screw 1 and the washer 4. The screw 1 consists of a head 2 and a threaded portion 3. Head seat surface 5 of the head 2
is provided with a single annular protrusion 6. The annular projection 6 is located on a concentric circle of the head seat surface 5 and has a triangular cross-sectional shape. Moreover,
The annular protrusion 6 has a height sufficient to close a gap R having a certain angle between the head seat surface 5 and the washer 4 caused by the inclination of the threaded portion 3 along the lead angle of the thread 12 during fastening. ing. Further, the threaded portion 3 is configured to be longer than the plate thickness of the mating member 11.

The washer 4 is made of polyvinyl chloride, a thermoplastic resin. Further, the washer seat surface 14 of the washer 4 is provided with an annular projection 15. The annular projection 15 is located corresponding to the annular projection 6.

The mating member 11 fastened by the washer assembly screw 13 consists of an upper plate member 8 and a lower plate member 9. A prepared hole 10 having a diameter larger than the outer diameter of the threaded portion 3 is pre-drilled in the upper plate material 8. Further, a pre-threaded hole 7 having a diameter smaller than the outer diameter of the threaded portion 3 is previously bored in the lower plate material 9.

The case where the washer built-in screw configured as described above is used for fastening a mating member will be explained based on FIG. 4.

First, the threaded portion 3 of the screw 1 is screwed into the pilot hole 7 of the lower plate 9 through the pilot hole 10 of the upper plate 8. Thereafter, the threaded portion 3 passes through the lower plate 9. At this time, when the threaded portion 3 is screwed in obliquely by the lead angle, a gap R is partially formed between the head seat surface 5 and the washer 4.
On the other hand, the annular projection 6 is partially deep and partially shallow in accordance with the inclination of the head seat surface 5, and the washer 4 is partially shallow.
It bites into. This annular projection 6 completely seals the gap R between the head seat surface 5 and the upper surface of the washer 4.

On the other hand, for this reason, the degree of adhesion between the washer seat surface 14 and the upper plate material 8 is not constant, and there may be parts where the degree of adhesion is incomplete. In this state, the annular projection 15 is plastically deformed in accordance with the degree of biting of the annular projection 6 into the washer 4. The annular projection 15 is partially wide and partially narrow, and is in close contact with the upper plate member 8. This annular projection 1
5, the washer seat surface 14 and the upper plate material 8
The degree of adhesion with the top surface is ensured by the entire circumference of the washer 4,
The washer seat surface 14 and the upper plate member 8 are in perfect contact with each other. As a result, even if the washer assembling screw 13 is tilted diagonally by an angle corresponding to the lead angle, the entire area of the washer 4 is reliably compressed, and the washer assembling screw 13 fastens the mating member 11.

In addition, as in the above case, if the upper plate material 8
Since the alignment between the pilot hole 10 and the screw pilot hole 7 of the lower plate material 9 is insufficient, a part of the upper plate material 8 blocks a part of the screw pilot hole 7, and the screw part 3 Even in the gap R between the head seat surface 5 and the washer 4, which occurs when the washer is screwed in an obliquely inclined state regardless of the lead angle, the annular protrusion 6
seals the gap. And the annular projection 6
applies a compressive load to the washer 4, and at the same time the annular projection 15 is plastically deformed. As a result, the washer 4 and the upper plate 8 come into close contact with each other, and further, the upper plate 8 and the lower plate 9 come into close contact with each other. In this way, complete watertightness is maintained between the washer assembly screw 13 and the mating member 11.

As explained above, the present invention provides a single annular protrusion on the head bearing surface, and the annular protrusion has a triangular cross-sectional shape. Because the height is high enough to close the gap between the seat and the washers, the screws will tilt diagonally when tightening.
Even if a gap is created between the head seat and the washer as a result of being screwed in, the annular protrusion that bites sharply into the washer completely closes the gap, preventing external moisture from flowing in through the gap. Therefore, there is no corrosion between the washer built-in screw and the mating material.
It has the effect of reliably maintaining watertightness.

In addition, since the present invention has an annular projection on the washer seat at a position corresponding to the annular projection on the head seat, when tightening the screw, the screw is screwed in at an angle, causing the washer seat and the upper plate to be screwed in. Even if an incomplete adhesion occurs between the annular protrusion and the annular protrusion, the annular protrusion undergoes a concentrated compressive load and undergoes plastic deformation, resulting in an even stronger adhesion. Therefore, in conjunction with the above effects, there is an effect of maintaining not only watertightness but also a high degree of airtightness without introducing moisture into the interior of the product.

In addition, in this invention, explanation was given only for the case where the annular protrusion on the head seat surface has one thread, but by making the annular protrusion into two or more threads, it is possible to completely prevent moisture from entering from the outside, and to improve the It is effective in maintaining not only reliable watertightness but also a high degree of airtightness.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view of a conventional washer assembly screw, Fig. 2 is a partially sectional front view showing the mounting state of the conventional example, and Fig. 3 is a partially sectional front view of the present invention.
FIG. 4 is a partially sectional front view showing an embodiment of the present invention;
Figure 5 is a sectional view taken along line A-A in Figure 3;
The figure is a cross-sectional view taken along line B-B in FIG. 3. 1...screw, 2...head, 3...screw part, 4...
...Watushia, 5...Head bearing surface, 6...Annular projection,
7...Screw pilot hole, 8...Upper plate material, 9...Lower plate material, 10...Prepared hole, 11...Mating material, 12...Screw thread, 13...Washer assembly screw, 14...Washer seat surface , 15... annular process.

Claims (1)

[Claims for Utility Model Registration] In the washer-integrated screw 13 which is composed of the head 2 and the threaded part 3 and which incorporates the washer 4 made of resin, a triangular shape is provided on the concentric circle of the head seat surface 5. An annular protrusion 6 having a cross-sectional shape and having a height sufficient to close the gap R between the head seat surface 5 and the washer 4 caused by the inclination along the lead angle of the screw thread 12 when fastened. On the other hand, a washer assembly screw characterized in that an annular projection 15 is provided on a washer seat surface 14 at a position corresponding to the annular projection 6.