JP5688263B2 - Metal waterproof washer - Google Patents

Description

  The present invention relates to a metal waterproof washer that provides a waterproof structure for a fastening part of a bolt and a nut, a rivet, and a blind fastener.

As a waterproof metal washer, there is one described in Patent Document 1 below. In this method, a washer made of a soft metal such as aluminum is used as a washer for a flanged plug. An inclined surface inclined in a taper shape is formed in advance on the radial outer periphery of a seating surface on which the washer is seated. The outer periphery of the washer is deformed into a tapered shape by fastening.
The seal washer described in Patent Document 2 below is obtained by joining a metal material and a rubber material. This seal washer ensures waterproofness by the elasticity of rubber.

Japanese Utility Model Publication No. 64-29210 Japanese Utility Model Publication No. 58-50220 Japanese Utility Model Publication No. 63-77114 JP 2005-264998 A

The conventional metal waterproof washer has a flat plate shape with a flat surface, and according to an experiment of the present inventor, it has become clear that its sealing performance is extremely weak in a hydraulic pressure state.
This is presumed to be due to the following reason.
The heads of ordinary bolts and brand rivets are manufactured by forging and the screw parts are formed by rolling. At that time, deformation occurs in each part, which causes poor sealing performance. In other words, referring to FIG. 11, during forging, as shown in FIG. 11A, the lower surface of the head is not perpendicular to the shaft portion and is slightly inclined. As shown in (B), indentations and scratches occur on the lower surface of the head, the shaft, and the root of the head. As shown in (C), there is a curved portion at the root of the head portion and the shaft portion. (D) As shown in (E), the central axis of the head and the central axis of the shaft portion do not coincide with each other and are eccentric.

According to the JIS standard for hexagonal bolts with a nominal diameter of 6 mm, which has a similar accuracy, the allowable range is defined in B1180 as follows. The inclination angle of the head is 2 degrees or less, the eccentricity between the shaft and the head is 0.5 mm or less, and the radius of curvature of the root between the head and the shaft is 0.25 or more.
Among the deformations (A) to (E) described above, the inclination of the head most affects the sealing performance, and the sealing performance and water tightness are further impaired in combination with other deformations. Furthermore, a deformation | transformation part also exists partially in the preform | base_material itself fastened with a volt | bolt and a nut. For example, as shown in (F), when a hole in a base material is punched out by pressing, burrs or sagging occur, and as shown in (G), chamfering occurs after forming a burr generated by drilling.
Next, the conventional proposal of combining a rubber packing with a relatively high sealing property and a metal washer may cause deterioration of rubber due to long-term use.
Therefore, an object of the present invention is to provide a metal waterproof washer that is resistant to deterioration and has high sealing properties.

The present invention according to claim 1 is provided with an insertion hole (1) in the center and is made of a metal material softer than the material of the base material (2) and the fastening component (3) to be fastened,
At least one of the planes is formed on a tapered surface (4) having a gradually decreasing cross-sectional thickness from the center to the periphery and having an allowable inclination angle between the head of the fastening component (3) and the shaft portion (3a) or more . It has a flat washer body (5a)
The shaft portion (3a) of the fastening part (3) is inserted through the insertion hole (1), and faces the flat pressing surface (3c) of the head (3b), and the tapered surface (4) side is convex. The washer body (5a) is arranged so that
When the washer body (5a) is fastened by the fastening component (3), the outer peripheral edge of the bolt head does not first contact the face of the washer (5), and the center part moves toward the periphery. It is a metal waterproof washer that is configured to be gradually plastically deformed so that the tapered surface (4) is deformed into a flat plane, which is in close contact with the pressing surface (3c).

According to a second aspect of the present invention, in the metal waterproof washer according to the first aspect,
This is a metal waterproof washer having a cylindrical part (5b) at the center of the washer body (5a).

According to a third aspect of the present invention, in the metal waterproof washer according to the first or second aspect,
It is a metal waterproof washer that is one of mild steel, aluminum material, aluminum alloy material, copper material, and copper alloy material.

The metal waterproof washer of the present invention is made of a soft metal material having a tapered surface 4 having a gradually decreasing cross-sectional thickness from the center to the periphery on at least one plane thereof, and the flat portion of the head 3b of the fastening part 3 is flat. The washer body 5a is arranged so as to be opposed to the pressing surface 3c so that the tapered surface 4 side is convex, and during the fastening, the washer body 5a is gradually plastically deformed from the center toward the periphery, so that the material of the center part of the washer is It moves to a peripheral part and they can adhere to a fastening surface smoothly and can obtain a waterproof effect.
Moreover, since the tapered surface 4 is formed so as to be equal to or larger than the allowable inclination angle between the head of the fastening part 3 and the shaft portion 3a, the outer peripheral edge of the bolt head first comes into contact with the surface of the washer 5. Without touching, it contacts from the axial part vicinity of the head part of a volt | bolt, and plastically deforms, The deformation | transformation member fills the clearance gap between the washer 5 and the press surface 3c.
In this way, the plastically deformed material moves toward the bolt shaft, and when there is an indentation or a flaw on the periphery of the shaft of the fastening part, the portion is simultaneously filled with the deformable material, and the waterproof effect Can be ensured.

Sectional drawing and front view of the metal waterproof washer of this invention. Explanatory drawing which shows the state before and behind the fastening of the said washer. The transition explanatory drawing of the deformation of the washer. Sectional drawing and the front view of 2nd Example of the metal waterproof washer of this invention. Sectional drawing and front view of 3rd Example of the same washer. The longitudinal cross-sectional view which shows the other use condition of the metal waterproof washer 5 of the 1st Example. The longitudinal cross-sectional view which shows the state before and behind the fastening of the metal waterproof washer 5 of the 2nd Example. The longitudinal cross-sectional view which shows the other use condition of the metal waterproof washer 5 of the 2nd Example. Explanatory drawing before the attachment of FIG. The vertical cross-sectional view (A) and bottom view (B) of the waterproof test when the metal waterproof washer of the present invention is applied to the blind washer, the cross-sectional view (C) of the principal part of the fastening part 3, and the metal waterproof used therefor A front view (D) and a plan view (E) of the washer 5 are shown, and a front view (F) and a plan view (G) of a conventional metal waterproof washer are shown. Explanatory drawing of the abnormal deformation | transformation on production of a normal bolt, and explanatory drawing of the deformation | transformation state of the hole edge of a base material.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view and a sectional view of a metal waterproof washer of the present invention.
The metal waterproof washer 5 is made of a metal material that is softer than the material of the base material 2 and the fastening component 3 to be fastened. For example, when the base material 2 and the fastening part 3 are usually steel materials, aluminum materials, copper materials, brass materials, or annealed mild steel materials are used. An insertion hole 1 is provided at the center of the metal waterproof washer 5, and one flat surface is formed as a tapered surface 4 whose sectional thickness gradually decreases from the center toward the periphery.
In this example, the tapered surface 4 is formed on the upper surface side, but it may be provided on the lower surface side, or the tapered surface 4 may be provided on both surfaces.
As shown in FIG. 2, the metal waterproof washer 5 is interposed between a bolt head 3 b that is a fastening part 3 and a base material 2. In this example, a bolt hole is drilled in the pair of base materials 2, and the shaft portion 3 a of the fastening part 3 is inserted there and fastened by the nut 6.

FIG. 2A shows the inserted state, and FIG. 2B shows a state where the nut 6 is fastened.
As the nut 6 is fastened, the taper surface 4 of the metal waterproof washer 5 begins to be plastically deformed near the thick shaft as shown in FIG. 3A, and the deformed material first moves to the bolt shaft side. Then, while being in contact with the shaft portion, it is pushed down to the tip side of the shaft portion. When the gap between the washer 5 and the shaft portion of the bolt is filled to some extent, the deformable material then moves to the peripheral side of the washer 5. By the movement, the pressing surface 3c of the head 3b and the flat surface of the metal waterproof washer 5 are brought into close contact with each other. As a result, the gap is completely closed to obtain waterproofness.
In addition, the material of the taper portion also moves on the lower surface side of the metal waterproof washer 5 to cause slight deformation, and the plastic deformation member moves there, and the base material 2 and the metal waterproof washer 5 are also in close contact with each other. It becomes a state.

The taper angle of the taper surface is a taper angle that is equal to or greater than the allowable maximum inclination between the head and the shaft of a commercially available bolt. By doing so, the outer peripheral edge of the head of the bolt does not contact the face of the washer 5 at first, but comes into contact with the vicinity of the shaft of the head of the bolt and is plastically deformed. The gap between the pressing surfaces 3c is filled. For example, since the maximum inclination angle (the inclination of the seating surface) is 2 degrees as described in JIS 1180, the inclination of the taper portion must be 2 degrees or more in the case of an ordinary hexagon bolt.
As described above, the material that is plastically deformed by the pressing surface 3c at the periphery of the bolt shaft moves toward the shaft portion of the bolt. Filling with deformable material is performed simultaneously. Further, even if a gap is formed between the pressing surface 3c and the washer 5 due to the curved portion existing at the base that transitions from the head portion of the bolt to the shaft portion, the deformable material moves to that portion to fill the gap, Watertightness can be ensured.

Next, FIG. 4 shows a second embodiment of the metal waterproof washer 5 of the present invention. In this example, a cylindrical portion 5b is projected from the center of a flange-shaped washer body 5a. A tapered surface 4 is formed on the upper surface of the washer body 5a, and the thickness of the washer body 5a is gradually reduced from the center to the periphery. As shown in FIGS. 7 and 8, the metal waterproof washer 5 is inserted into the drilled hole of the base material 2. Providing this cylindrical portion 5b is advantageous in the following points.
For example, the hole of the base material 2 is punched by a drill or a press. At this time, burrs are generated around the hole edge in the drill hole, and chamfering is normally performed (see FIG. 11G). In the press hole, sagging occurs on the punch side and burrs occur on the die side around the hole edge (see FIG. 11F). It should be noted that the surface of the sagging or burrs generated by this pressing can be any surface in the subsequent fastening process of bolts or rivets that are fasteners.
The present application provides an effective solution even when the cylindrical portion 5b has burrs, sagging or chamfering around the hole edge.

Next, the operation of the cylinder part 5b will be described. In addition, the effect | action of close_contact | adherence states other than the following exhibits the same effect as a 1st Example.
FIG. 7A shows the inserted state, and FIG. 7B shows a state where the nut 6 is fastened.
As the nut 6 is tightened, the taper surface 4 of the metal waterproof washer 5 begins to be plastically deformed from the thicker center side as shown in FIG. Then, it moves to the peripheral side. The material plastically deformed by the pressing surface 3c of the fastening part 3 moves to the shaft portion of the fastening device 3 and is pushed down toward the tip end side of the shaft portion while being in contact with the shaft portion. At this time, the entire cylindrical portion 5b of the washer 5 also starts to move and deform the material downward. When the gap between the washer 5 and the shaft portion of the fastening component 3 is filled to some extent, the deformable material subsequently moves to the peripheral side of the washer 5. Then, the entire cylindrical portion 5b of the washer 5 moves further downward.

  This movement is constituted by the washer main body 5a and the cylindrical portion 5b, and a force is applied to the vicinity of the shoulder portion of the cylindrical portion 5b, and the force is also transmitted to the vicinity of the hole edge of the base material 2. First, when there is a burr around the hole edge of the base material 2 (see FIGS. 11 (F) and 11 (G)), this force deforms the burr and blends with the shoulder portion of the washer body 5a. It is possible to bite the main body 5a with burrs. Secondly, when there is a sag or chamfer around the hole edge of the base material 2 (see FIGS. 11 (F) and (G)), the shoulder of the washer body 5a is bent along these, and the base material 2 Adhesion with the edge of the hole is improved.

Next, FIG. 5 shows a third embodiment of the metal waterproof washer 5 of the present invention. The difference of this example from that of FIG. 4 is that the cylindrical portion 5b is longer, and the others are shown in FIG. This is the same as the fourth embodiment.
The length of the cylindrical portion 5b can be set to approximately the same as the thickness of the base material 2 on the washer 5 side. By setting it as such a shape, the washer 5 can be stably mounted in the hole of the base material 2.

Next, in the examples of FIGS. 6 and 8, the metal waterproof washer 5 of the present invention is used as a blind rivet.
This blind rivet is known per se and its preparation stage for installation is shown in FIG. In this case, a mandrel 7 is inserted into a cylindrical rivet body which is a fastening part 3. The mandrel 7 is provided with a skirt 8 at the lower end thereof, and a constriction 9 for separation is formed at a position substantially the same as the length of the rivet body from the lower end thereof.

As shown in FIG. 9, the blind rivet body and the mandrel 7 as the fastening parts 3 are inserted through the insertion holes of the pair of base materials 2 via the metal waterproof washer 5, and the head 3b of the head 3b is shown in the figure by a rivet machine (not shown). While pressing the upper surface downward, the upper end of the mandrel 7 is pulled upward. Thereby, as shown in FIG. 8, the skirt portion 8 enters the hollow portion of the shaft portion 3 a of the main body, expands and deforms there, and fastens the pair of base materials 2. At the same time, the taper surface of the metal waterproof washer 5 is flatly plastically deformed to ensure waterproofness. And the mandrel 7 is isolate | separated in the position of the constriction part 9 after the plastic deformation.
In FIG. 6, the metal waterproof washer 5 is the one of the first embodiment.

[Waterproof experiment]
The inventor conducted a waterproof test on the blind rivet of FIG.
As a metal waterproof washer 5 of aluminum material (A1050-O material), as shown in FIGS. 10E and 10D, the diameter of the washer body 5a is 13.4 mm, the center hole is 6.8 mm, and the outside of the cylindrical portion 5b. Prepare one having a diameter of 8.4 mm, a washer body 5a thickness of 1 mm, and a taper angle of taper surface 4 of 5 ° (taper height 0.28 mm).
The blind rivet is manufactured by Abdel, Inc. under the trade name: monobolt, product number: 2771-1817, head diameter 13.4 mm, head thickness 2.7 mm, shaft diameter 6.4 mm, and shaft neck length 14. 2 mm and a bonding plate thickness possible range of 2.1-9.5 mm are used.
The joining plate was a steel plate SPCC material, and two 2.3 mm plates (total 4.6 mm) were used, the rivet head side hole diameter was 8.5 mm, and the rivet shaft end side hole was 6.8 mm.
A steel material was fastened as a fastening part 3 with a blind rivet through a washer 5 as shown in FIG. After fastening, as shown in FIGS. 10 (A) and 10 (B), it is liquid-tightly fixed to a test jig 10 having an open lower end with a plurality of bolts 11 through an O-ring 12, and colored water is previously placed inside the test jig 10. Enclose. Then, high-pressure gas was supplied into the test jig 10 via the valve 13.

Further, as a comparative example, as shown in FIGS. 10F and 10G, it is made of the aluminum material (A1050-O material), and the washer main body 5a and the cylindrical portion 5b are the same as those in FIGS. 10E and 10D. The top surface was flat with no taper. In both cases, the air pressure was sequentially increased from 0 Mpa to 0.9 Mpa by 0.1 Mpa.
As a result, as shown in Table 1, the metal waterproof washer 5 having the tapered surface 4 of the present invention did not leak at any pressure. On the other hand, in the comparative example, there was no water leakage only when the pressure was 0, and there was water leakage at all pressures of 0.1 Mpa or more.
In Table 1, ◯ indicates that there is no water leakage, and X indicates that there is water leakage.
After the test, it was cut from the center of the brand rivet and the cross section was observed. Some gaps were observed in the inner and outer peripheral axial directions of the cylindrical portion 5a of the metal waterproof washer 5, but the lower surface of the rivet head, the upper surface of the washer body 5a, the lower surface of the washer body 5a, and the steel plate (base material). In the contact area, the contact state was obtained. Thereby, it was confirmed that watertightness was ensured in the upper and lower plane portions of the body portion 5a of the metal waterproof washer 5.

In addition, the inventor conducted the same experiment when the taper angle of the taper surface 4 was 3 ° to 7 °, and the result was the same as in Table 1. Therefore, the taper angle of the taper surface 4 is predicted to have a waterproof effect at about 2 ° to 10 °, and more preferably 3 ° to 7 °.
In addition, when forming the taper surface 4 on both surfaces, the sum total of both the taper is 2 degrees-10 degrees, More preferably, the sum total is 3 degrees-7 degrees.

1 Insertion hole 2 Base material 3 Fastening parts
3a Shaft
3b head
3c Press surface

4 Tapered surface 5 Metal waterproof washer
5a Washer body
5b Tube 6 Nut 7 Mandrel 8 Skirt

9 Constriction
10 Test jig
11 volts
12 O-ring
13 Valve
14 Comparison washer

Claims (3)

An insertion hole (1) is provided in the center, and is made of a metal material softer than the material of the base material (2) and the fastening part (3) to be fastened,
At least one of the planes is formed on a tapered surface (4) having a gradually decreasing cross-sectional thickness from the center to the periphery and having an allowable inclination angle between the head of the fastening component (3) and the shaft portion (3a) or more . It has a flat washer body (5a)
The shaft portion (3a) of the fastening part (3) is inserted through the insertion hole (1), and faces the flat pressing surface (3c) of the head (3b), and the tapered surface (4) side is convex. The washer body (5a) is arranged so that
When the washer body (5a) is fastened by the fastening component (3), the outer peripheral edge of the bolt head does not first contact the face of the washer (5), and the center part moves toward the periphery. A metal waterproof washer that is configured to be gradually plastically deformed so that the tapered surface (4) is deformed into a flat plane, which is in close contact with the pressing surface (3c). The metal waterproof washer according to claim 1,
A metal waterproof washer having a cylindrical portion (5b) at the center of the washer body (5a). In the metal waterproof washer according to claim 1 or 2,
A metal waterproof washer that is one of mild steel, aluminum material, aluminum alloy material, copper material, or copper alloy material.

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