JPS6227700Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a washer-integrated bolt that can reliably prevent the tightened bolt from reversing.

Conventionally, in this type of built-in bolt, a washer is fitted before the male thread is carved, and the washer is prevented from coming off from the underside of the head due to the male thread being carved.
It is heat treated together with the washer, and when the bolt is tightened to the object to be tightened, the elastic washer is strongly pressed against the underside of the bolt to prevent it from loosening, but the bolt itself is heat treated and hardened. Since the bottom surface remains smooth, it is difficult for the washer to fit into the bottom surface of the bolt, and there is a risk that the bottom surface of the bolt and washer may slip and loosen due to vibrations or other external forces, causing an unexpected situation. In order to prevent the occurrence of the above-mentioned slipping, a special and large flange is integrally formed around the lower edge of the head, and a large number of tooth shapes with apex angles are radially carved on the lower surface of the flange. Some models are equipped with washers that have the same number of tooth profiles on the upper and lower surfaces that match the multiple tooth profiles on the lower surface of the collar, but this not only makes the head structure cumbersome, but also makes the radial shape on the lower surface of the collar difficult. The same number of tooth profiles that fit a large number of tooth profiles must be accurately formed on the surface of the washer, which requires a lot of work and is not easy to manufacture.

The present invention was devised in order to eliminate the disadvantages of conventional built-in bolts of this kind as described above, and when the bolt is tightened, the lower edge of the sloped teeth continuously provided around the washer tends to bite. The bolt is brought into pressure contact with the member to be tightened, and the upper edge of the inclined tooth part, which is tilted upward by the upper pressure action of the member to be tightened, is engaged with the engagement groove provided on the inclined circumferential surface of the lower edge of the head of the bolt. It is an object of the present invention to provide a washer-integrated bolt that can reliably prevent rotation in the direction of loosening.

An example of the implementation of the present invention will be described in detail with reference to the drawings. A bolt 3 is made of steel and has a shallow inclined circumferential surface 2 formed on the lower edge of the head 1. A large number of engagement grooves 4 are provided on the inclined circumferential surface 2 of the lower edge of the shaft 1 toward the axis.

Further, the engagement groove 4 on the inclined peripheral surface 2 of the bolt 3 is
The washer 7 is made of steel plate and has inclined teeth 6 formed continuously at equal intervals around its periphery, the upper edge 5 of which is in the same direction, and the lower edge of which is inclined downward at a smaller angle than the inclined circumferential surface 2. It is configured.

Then, the washer 7 is fitted onto the shaft portion 8 of the bolt 3 and positioned on the lower surface of the head 1, and then a male thread 9 is cut into the shaft portion 8, and a crest 9' of the male screw 9 is Therefore, the washer 7 is locked onto the shaft portion 8, and the bolt 3 incorporating the washer 7 is heat-treated.

In addition, the reference numeral 10 in the drawings is an engagement recess provided on the upper surface of the head 1 of the bolt 3, into which the angular engagement end 11' of the wrench 11 is freely engaged.

Next, to explain the function of the present invention, the bolt 3 is made of steel and has an inclined peripheral surface 2 on the lower edge of the head 1.
and an engagement groove 4 extending toward the axis on the inclined peripheral surface 2.
The engaging groove 4 and the upper edge 5 of the inclined circumferential surface 2 of the bolt 3 are arranged in the same direction, and the lower edge is inclined downward at a smaller angle than the inclined circumferential surface 2. Since the washer 7 having the inclined teeth 6 continuously provided on the periphery is formed of a steel plate material and is assembled on the shaft portion 8 of the bolt 3, the washer 7 is attached to the object a to be tightened as shown in FIG. When the member b is tightened with the bolt 3, the washer 7 is pressed by the lower surface of the head 1 of the bolt 3, and the downwardly inclined lower edge of the inclined teeth 6 continuously provided around the washer 7 tends to bite. While being brought into pressure contact with the upper surface of the member to be tightened b, the inclined tooth portion 6 is tilted upward by the upper pressure applied to the downwardly inclined lower edge by the member to be tightened, and the lower edge of the head 1 of the bolt 3 is tilted upward. The upper edge 5 of the inclined tooth portion 6 engages with the engagement groove 4 provided on the inclined peripheral surface 2,
Prevents the bolt 3 from rotating in the direction of loosening.

That is, in the present invention, by tightening the bolt 3 as described above, the downwardly inclined lower edge of the inclined tooth section 6 continuously provided around the washer 7 on the upper surface of the member b to be tightened is slightly bitten. The washer 7 is kept in the normal position, and the inclined tooth part 6 pressed against the downwardly inclined lower edge on the upper surface of the member b to be tightened is inclined upward to tilt the inclined circumferential surface 2 of the lower edge of the head 1 of the bolt 3. The upper edge 5 of the inclined toothed portion 6 is elastically engaged with the engagement groove 4 of the bolt 3, and the washer 7 and the bolt 3 can be firmly connected and integrated. It is possible to securely maintain the tension without causing excessive rotation in the direction of loosening, and therefore it can be safely used for tightening and fixing vibrating members or rotating members, etc. It has a simple structure and can be manufactured at low cost.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention. Figure 1 is a front view, Figure 2 is a bottom view of the bolt, Figure 3 is a plan view of the washer, Figure 4 is a front view of the washer, and Figure 5 is a front view of the washer. FIG. 6 is an enlarged front view showing a section of the upper part of the bolt and the assembled part of the washer, and FIG. 6 is an explanatory view with a part cut away showing the tightened state. 1... Head, 2... Inclined peripheral surface, 3... Bolt,
4... Engagement groove, 5... Upper edge, 6... Inclined tooth portion,
7... Washer, 8... Shaft, 9... Male screw,
9'...Yamabe.

Claims (1)

[Claim for Utility Model Registration] Before carving a male screw into the shaft of a bolt made of steel, a washer made of a steel plate material is fitted, and then a male screw is carved into the shaft of the bolt. A washer is locked near the lower surface of the bolt head at the crest of the thread, and a bolt is connected in this way, and a washer-integrated bolt in which the washer is heat-treated has an inclined circumferential surface 2 on the lower edge of the head 1 of the bolt 3. The inclined peripheral surface 2 is provided with a plurality of engaging grooves 4 facing the axis, while the engaging grooves 4 and the upper edge 5 are oriented in the same direction and at a smaller angle than the inclined peripheral surface 2. A washer-integrated bolt in which an inclined toothed portion 6 having a downwardly inclined lower edge is formed around a washer 7.