JPH01131313A - Tightening forgetting preventive washer for screw tool - Google Patents

Abstract

PURPOSE: To avoid the oblivion of fastening with an inner portion and an outer portion of a washer by forming a peripheral wall on the outer peripheral edge of a hole through which a bolt is inserted, and providing the flat disc-shaped washer body with a groove hole or a slit capable of slitting at or above a predetermined torque around its outer periphery. CONSTITUTION: A washer body 1 around the outer periphery of a hole 3 through which a central bolt is inserted is provided with a circular arc-shaped slit 4 or a groove 5. When changing the state of a bolt or a nut from temporary fastening to dead fastening, an inner portion 11 and an outer portion 12 of the washer body 1 are slit from each other by the slit 4 or the groove 5. The slit 4 associates the inner portion 11 and the outer portion 12 of the washer 11 at the position of a radius equal to that of the nut or the head of the bolt. Two associating portions 13 are formed. In order to easily identify the states of the dead fastening and the temporary fastening, the outer portion 12 of the slit 4 or groove 5 is colored by paints or the like. The improvement of readiness, operability and accuracy is expectable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a washer for preventing forgetting to tighten a screw tool.

[Conventional technology and its problems]

In construction, civil engineering work, and other equipment installation work, bolts, nuts, and other screws are temporarily tightened, and after alignment and other surface position adjustments are made, the screws are fully tightened and fixed. Various proposals have been made so that this completely fastened state can be visually confirmed from the outside. For example, there is one shown in FIG. This is a product in which a washer is placed on the underside of a screw such as a bolt or nut, the screw and washer are wrapped together in a packaging film, and perforations for breaking are formed in the packaging film along the axial direction. It is. Therefore, in order to use this, first insert and temporarily tighten the bolts 21 of each screw washer set into the object 26 to be tightened (for example, a column and beam), and then temporarily tighten all the bolts 21. After this is completed, tighten the bolts (pole) 21 again one by one. In the case of temporary tightening, the washer 22 rotates together with the bolt 21, so the packaging film 23 will not be torn. 21, the packaging film 23 is torn from the perforation 24, and the packaging film 28 comes off from the pole 21 and washer 22, making it possible to distinguish between the temporary tightening state and the final tightening state. There is.

However, first, the lower end of the first stage portion 25 of the washer 22 comes into contact with the object to be tightened, so if this end is covered with the packaging film 23, the washer 22 will come into contact with the object to be tightened. When the washer 22 is clamped, the packaging film 23 covering the end of the washer 22 is elastically sandwiched between the washer 22 and the clamped object 26, so even if the packaging film 23 is torn, it will not be removed from the washer 22. There was a problem with it not coming off. Then, if the packaging film 23 does not come off,
It was difficult to identify when the final tightening was completed, and it was also impossible to dispose of the packaging film 23. Note that if you try to remove this packaging film 23, remove the fully tightened bolts 2.
1, remove the packaging film 2a, and then tighten the bolt 2 again.
1 must be tightened, which has the disadvantage that construction is complicated.

Furthermore, it is time-consuming to package the stopper and washer together with a film before use.

The purpose of the present invention is to omit this film packaging and to distinguish between temporary tightening and final tightening by looking.

[Means for solving problems]

A hole is formed in the center for inserting the bolt, and a peripheral wall is formed on the outer periphery.
Further, a cutting slit or groove is formed in the outer circumferential direction of the hole so that the flat disk-shaped washer body can be separated by a predetermined torque or more.

〔Example〕

The washer for preventing forgetting to tighten a screw according to the present invention will be explained below based on the illustrated embodiment.

Figures 1 to 3 show the present invention. In Figure 0, 1 is a washer body, which is formed with a desired metal plate into a flat disk shape with a diameter larger than the head diameter of the nut or bolt. A ring-shaped peripheral wall 2 is continuously provided on the outer peripheral edge, and a hole 3 into which a bolt is inserted is bored in the center of the washer body. Also, in the washer body 1 in the outer circumferential direction of this hole 3, there is a separation slit 4 or a groove 5.
is formed into an arc shape, so that when the bolt or nut is fully tightened from the temporarily tightened state, the inner part 11 and outer part 12 of the washer body l are separated from the separation slit 4 or groove 5. to be separated. The separation slit 4 connects the inner part 11 of the washer body and the outer part 12 of the washer body of the separation slit 4 at a position having a diameter equal to the diameter of the bolt head or nut. One or two continuous portions 13 are formed. At this continuous portion 13, the inner portion 11 and outer portion 12 of the washer body 1 are integrated in front of the main line.

In the case of the cut R groove 6, a ring-shaped V-shaped groove or other shaped groove is carved along the outer circumferential direction of the hole 3 at a position with a diameter equal to the bolt head diameter or nut diameter.

In addition, the outer part 12 of the separation slit 4 or 115 of the washer body 1 is colored with red or another easily detectable color by painting or other means so that the distinction between final tightening and temporary tightening can be easily distinguished.

Therefore, in order to use the washer for preventing forgetting to tighten, which is configured as described above, the washer main body l of the present invention is disposed at the screwed location of the column, beam, or other object 8 to be tightened. At this time, the end surface of the ring-shaped peripheral wall 2 is brought into contact with the object 8 to be tightened, and this state is shown in FIG. 4. Then, a spring washer 6 is stacked on the surface of this washer body l, and this spring washer 6,
Insert the bolt 7 so as to pass through the hole 3 of the washer body l,
The bolt 7 is screwed into the screw hole 81 of the object 8 to be tightened. In this way, temporary tightening work is performed.

Although the bolt 7 is a hexagon socket head bolt in the illustrated embodiment, a bolt with a hexagonal head can also be used.Furthermore, the bolt is installed in the object 8 to be tightened, and the washer body 1 is attached to the bolt. , nut (not shown) via spring washer 6
You can also screw them together.

After adjusting the mounting position and the like, when performing final tightening, the spring washer 6 is pressed by the bearing surface of the head 71 of the bolt 7. The pressing force due to this bolt tightening is also transmitted to the washer body l via the spring washer 6. As the bolts are tightened, the pressing force gradually becomes stronger, and the flat disc-shaped washer main body 1 receives a pressing force on the inner part 11 inside the separation slit, and the reaction force acts on the ring-shaped peripheral wall 2. As a result, when a predetermined pressing force is applied, stress is concentrated between the inner portion 11 and the peripheral wall 2 of the washer body 1, as shown in FIG. 5, and is applied to the continuous portion 13. As a result, it is bent from the continuous portion 13 (or the separation groove 5). Further, when the bolt is tightened to a predetermined tightening torque or higher, the continuous portion 13 or (separation groove 5) is sheared, and the inner portion 11 is inserted into the bolt head via the spring washer 6. However, the outer portion outside the slit and the peripheral wall 2 are separated. At this time, washer body 1
If the continuous part 13 of the washer is colored, the outer part 13 will be separated and removed after fastening, so the colored washer body will not be visible from the outside and the completion of fastening can be visually confirmed. be.

〔Effect of the invention〕

The washer for preventing forgetting to tighten screws of the present invention has a hole in the center for inserting the bolt, a peripheral wall on the outer periphery, and a cut-off slit or groove in the flat disc-shaped washer body so that it can be separated with a predetermined torque or more. Since it is formed in the outer circumferential direction of the hole,
The tightening of bolts and nuts can be reliably confirmed, and the conventional process of packaging the nuts and washers together with a film or tearing the packaging film can be omitted, improving workability and accuracy. There are advantages.

[Brief explanation of the drawing]

Fig. 1 is a plan view, Fig. 2 is a cross-sectional view, Fig. 3 is a cross-sectional view of the separation groove type embodiment, Fig. 4 is an illustration of temporary tightening, and Fig. 5 is an illustration of the completion of tightening. 6 are known examples. 1 is the washer body, 11 is the inner part, 12 is the outer part, 13 is the continuous part, 2 is the peripheral wall, 3 is the hole, 4 is the separation slit, 5 is the separation groove, 6 is the spring washer, 7 is the Bolt, 71 is the head, 8 is the object to be tightened. Figure 4 Figure 5

Claims (1)

[Claims] (1) A washer for preventing loosening placed on the bearing surface of screws such as bolts and nuts.A washer to prevent forgetting to tighten the screws, which is placed on the underside of the bearing surface of screws such as bolts and nuts. A washer for preventing forgetting to tighten a screw, characterized in that a peripheral wall is formed, and a cut-off slit or groove is formed in the outer circumferential direction of the hole so that the washer body can be separated by a predetermined torque or more in a flat disc-shaped washer body.