JPH0432250B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a screw washer set in which a screw tool such as a bolt or nut and a washer are integrally packaged with a packaging film such as a shrink film.

[Background technology]

In the conventional screw washer set, the bolt 1 is inserted into the spring washer 4, as shown in FIG.
A spring washer 4 is placed on the lower surface of the bolt 1, and the head of the bolt 1 and the spring washer 4 are wrapped tightly with a packaging film 5 such as a shrink film. The entire layer 4 was wrapped in a packaging film 5. Therefore, the method of use is to first insert and temporarily tighten the bolts 1 of each screw washer set, for example, into the joint between the column 9 and the beam 11, and then temporarily tighten all the bolts 1. Afterwards, the bolts 1 are fully tightened one by one again. Here, in the case of temporary tightening, the spring washer 4 rotates together with the bolt 1, so the packaging film 5 will not be torn, but the spring washer 4 will come into pressure contact with the column 9 and will no longer rotate. When the bolt 1 is turned in this state, the packaging film 5 breaks at the perforation 8 and is torn, and the packaging film 5 comes off from the bolt 1 and spring washer 4, making it possible to distinguish between the temporarily tightened state and the fully tightened state. It was becoming like that.

However, first, the lower end 7 of the cut portion 6 of the spring washer 4 comes into contact with the pillar 9, so if this end 7 is covered with the packaging film 5, the spring washer 4 will touch the pillar 9. 9, the packaging film 5 covering the end 7 of the spring washer 4 is elastically sandwiched between the spring washer 4 and the column 9, and the packaging film 5 is torn. There was a problem that the spring washer 4 could not be removed. If the packaging film 5 does not come off, it is difficult to identify when the final tightening is complete, and the packaging film 5 cannot be disposed of. In addition, in order to remove this packaging film 5, it is necessary to loosen the bolt 1 that has been fully tightened, remove the packaging film 5, and then tighten the bolt 1 again, which complicates the construction.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned technical background, and its purpose is to easily prevent torn packaging films from being caught under the spring washer when fully tightened. The purpose is to ensure that it is removed.

[Disclosure of the invention]

In the screw washer set of the present invention, a spring washer 4 is stacked on the underside of a screw 3 such as a bolt 1 or a nut 2, and the screw 3 and spring washer 4 are packaged together with a packaging film 5. In a screw washer set in which a perforation 8 for breaking is formed in the packaging film 5 along the axial direction, the lower end 7 of the stepped portion 6 of the spring washer 4 is inserted into the packaging film. 5 is exposed. However,
When the screw 3 is finally tightened after being temporarily tightened, the packaging film 5 breaks at the perforation 8 and breaks.
The temporary tightening state and the final tightening state can be distinguished by the presence or absence of the packaging film 5. Moreover, since the lower end 7 of the spring washer 4 that contacts the object to be tightened is exposed from the packaging film 5, when the bolt 1 is tightened, the end 7 of the spring washer 4 and the object to be tightened are exposed. The packaging film 5 is not caught between objects and cannot be removed, and construction can be simplified.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. What is shown in FIGS. 1 to 3 is a case where the screw 3 is a bolt 1, and this bolt 1 has a cylindrical outer circumference and a hexagonal recess 10 in the upper surface. It can be tightened with a tool such as a hex wrench. The spring washer 4 has an annular shape with a portion cut in different steps, and is inserted into the threaded portion 12 of the bolt 1 and disposed on the lower surface (head) of the bolt 1. The packaging film 5 is a tube-shaped heat-shrinkable shrink film such as shrinkable vinyl chloride (0.07 mm thick), and is heat-shrinked so as to wrap around the head of the bolt 1 and the spring washer 4. packaging film 5
is brought into close contact with the bolt 1 and the spring washer 4, and a perforation 8 is formed in the axial direction. The packaging film 5 or the perforations 8 cannot be torn under normal loads, but has enough strength to be torn when twisted using a tool.
The diameter shall be 1.7 mm or more, and the diameter of A shown in Figure 3 shall be met.
One or two perforations 8 are provided within an angle of 205 degrees. Moreover, the end 7 of the cut portion 6 protruding toward the lower surface side of the spring washer 4 (the side opposite to the head of the bolt 1) is exposed without being wrapped in the packaging film 5, and this exposed range is It is within 45 degrees of B in Figure 3.

Next, the operation will be explained according to FIGS. 4 to 12. Tighten the threaded portion 12 of the bolt 1 on the object 13
When the spring washer 4 and the bolt 1 are inserted into a column (such as a column and a beam) and tightened with a tool such as a wrench, the spring washer 4 and the bolt 1 rotate together because they are initially wrapped together with the packaging film 5. As shown in FIG. 4, when the end 7 of the spring washer 4 comes into contact with the object 13 to be tightened, the spring washer 4 gradually tightens.
is compressed between the object 13 to be tightened and the bolt 1, and as the spring washer 4 is compressed as shown in FIG. 5, the spring force of the spring washer 4 increases and the frictional force with the object 13 to be tightened increases. Due to this frictional force, the spring washer 4 gradually begins to lag behind the rotation of the bolt 1. When a difference in rotation occurs between the bolt 1 and the spring washer 4, the packaging film 5 becomes twisted because it is in close contact with the bolt 1 and the spring washer 4, as shown in FIG. When the packaging film 5 is strongly rotated by a tool and the twisting force reaches a point where the perforations 8 are cracked, the packaging film 5 cracks from the part where the spring washer 4 is applied, as shown in FIG. enters. When the bolt 1 is further rotated in this cracked state, the end 7 of the spring washer 4, which is in contact with the object 13 to be tightened, is pushed upward, as shown in FIG. A downward force is applied to this point, and the packaging film 5 is removed from the spring washer 4. When the packaging film 5 is removed from the spring washer 4, the packaging film 5 rises as shown in FIG.
comes into contact with the side of the Further, when the bolt 1 is rotated, the lower end of the packaging film 5 spirals along the side circumferential surface of the spring washer 4 and rises upward, as shown in FIG. Also,
The remaining portions that were hooked on the lower surface of the spring washer 4 are pulled up one after another as the bolt 1 rotates, and come into contact with the side peripheral surface of the spring washer 4. The packaging film 5 that had gradually gotten caught on the back side of the spring washer 4
When the lower end comes into contact with the side peripheral surface of the spring washer 4, the diameter of the packaging film 5 tends to increase as shown in FIGS. 11 and 12, and the cracks at the perforations 8 become even larger. As a result, the packaging film 5 is completely separated from the bolt 1. Moreover, in this process, the lower end 7 of the spring washer 4 is exposed from the packaging film 5, so when the end 7 first contacts the object 13 to be tightened, the spring washer 4 The wrapping film 5 is not caught between the tightening object 13 and is smoothly peeled off from the bolt 1 when only the bolt 1 is rotated, leaving the spring washer 4.

The bolt shown in FIG. 13 is another example of the present invention, in which the bolt 1 shown in the first example is provided with a hexagonal recess 10 so that it can be tightened with a hexagonal wrench or the like. In the embodiment shown in FIG. 13, the outer periphery of the head of the bolt 1 is hexagonal so that it can be tightened with a spanner or the like.

Moreover, the one shown in FIG. 14 is still another example of the present invention, in which a spring washer 4 is arranged on the lower surface of a nut 2 which is a screw tool 3.
The nut 2 and the spring washer 4 are packaged together with a packaging film 5 with the lower end 7 of the nut 2 exposed.

〔Effect of the invention〕

Since the present invention is constructed as described above, the lower end of the spring washer that contacts the object to be tightened is exposed from the packaging film, so that when the bolt is tightened, the end of the spring washer is exposed. The packaging film is not caught between the part and the object to be fastened and cannot be removed, and the construction can be simplified.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing an embodiment of the present invention, Fig. 2 is a partially cutaway side view of the same, Fig. 3 is a bottom view of the same, and Figs. 4 to 12 are the same as the above. FIG. 13 is a partially cutaway front view showing another example of the present invention, FIG. 14 is a front view showing still another example of the present invention, and FIG. 15 is an explanatory view of a conventional example. DESCRIPTION OF SYMBOLS 1... Bolt, 2... Nut, 3... Screw, 4... Spring washer, 5... Packaging film, 6... Cut section, 7... End of cut section.

Claims (1)

[Claims] 1. A spring washer is stacked on the underside of a screw device such as a bolt or nut, the screw device and the spring washer are wrapped together with a packaging film, and the screw device and the spring washer are wrapped together in a packaging film along the axial direction. A set of screw washers having perforations for breaking, characterized in that the lower end of the stepped portion of the spring washer is exposed from the packaging film. . 2. The screw washer set according to claim 1, wherein the angle of the exposed end of the cut portion is within 45 degrees.