JPS6327134Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a loosening prevention device for a tightened portion such as a bolt or a nut.

Many devices have been proposed as such locking devices in the past, but the present invention further improves them, performs locking operation extremely simply and accurately, and can be easily manufactured by heading, etc. The aim is to obtain a device that can be obtained in large quantities at a low price and is easy to use and operate, and a washer 3 is interposed between the tightening part 1 and the tightening surface 2 of the screw. A serrated protrusion 4 is provided as an upward slope in the direction of rotation of the washer 2, and a serrated protrusion 5 that matches the protrusion 4 is provided on the surface of the washer 2 facing the tightening portion 1. The back surface of the washer 2 is provided with serrated projections 6 and 7 having inclined slopes in opposite directions on both sides of the diameter line A.

Embodiments of the present invention will be described with reference to the drawings.

Fig. 1 shows a tightening device using a bolt, in which a washer 3 is interposed between the tightening part 1 and the tightening surface 2 on the lower surface of the bolt head, and the tightening part 1 of the bolt is
The tightening portion 1 is provided with a serrated protrusion 4 having an upward slope in the direction of rotation during tightening.
The surface of the washer 3 facing the front side is provided with serrated protrusions 5 that mesh with the serrated protrusions 4 formed on the tightening part 1, and the back side of the washer 2 facing the tightening surface 2 is provided with serrated protrusions 5 as shown in FIG. As shown, serrated projections 6 and 7 with inclined slopes in opposite directions are provided symmetrically on both sides of the diameter line A.

FIG. 3 shows an example of tightening using a nut instead of the bolt tightening device of the above example, and its characteristic structure remains the same; in the illustrated example, a bolt is used for the threaded rod 12 combined with the nut. In the figure, 1 is the tightening part of the nut, 2 is the tightening surface, 3 is the washer, 4, 5, 6,
Reference numerals 7 denote serrations similar to those in the previous embodiment, and their functions and effects remain the same.

In FIG. 3, reference numeral 13 indicates a head piece molded integrally with the threaded rod 8 in the form of a bolt, and reference numeral 14 indicates a washer.

Note that the serrations 4, 5, 6, and 7 are not provided along the entire circumference of each member as shown in FIG. 4, but are partially provided with an appropriate number of tooth rows as shown in FIG. The protrusions 6 and 7 having opposite slopes on the back surface of the washer 3 may be provided locally on both sides of the straight line A, respectively.

In each of the above embodiments, when the bolt or nut is rotated in the direction of the arrow in the tightening operation, the serrated projections 4 formed on the tightening portion 1 engage with the serrated projections 5 on the surface of the washer 3. The part 1 is screwed in by rotating while pushing in the washer 3, and as a result of the screwing, the washer 3 bites into the tightening surface 2, so that the serrated protrusion 7 on the back side of the washer 3 is rotated in the tightening direction of the bolt or nut. The bolt and nut rotate while overcoming the engagement of the protrusions 4 and 5 without the washer 3 rotating as it acts as a resistance and is restrained in the rotation direction, so that the tightening operation by screwing is performed smoothly. Along with this, the washer 3 bites into the tightening surface 2 and the engagement with the tightening surface 2 becomes firm, and the engagement of the protrusions 4 and 5 causes the bolt and nut to rotate in the opposite direction, that is, in the loosening direction. Since the washer 3, which is bitten into the tightening surface 2, is also prevented from rotating in the loosening direction by the protrusion 6 on the back surface, loosening of the joint due to tightening can be prevented.

In order to ensure that the projections 6 and 7 on the back surface of the washer 3 engage with the clamping surface 2 by biting in the above operation, the washer 3 is made of a material harder than the material of the clamping surface 2, so that the engagement operation is further improved. It will be advantageous.

In addition, in this invention, the use of the front and back sides of the washer 3 is restricted, so if the bolt or nut and washer 3 are combined in a predetermined front-back relationship and joined together without separating them before use, it will be easier to tighten them. Work is advantageous. For this reason, in the case of a bolt, as shown in FIG.
In the case of a nut, an annular protrusion 10 is integrally formed on the lower surface of the nut as shown in FIG. The washer 3 is loosely fitted into the protrusion 10, and a retainer 11 such as a small protrusion is provided on the protrusion 10 to prevent the washer 3 from coming off.Thus, the bolt, nut, and washer 3 are individually released, and the washer 3 is removed for use. This eliminates the inconvenience of handling the parts by checking the front and back sides of the parts 3 and using them in combination.

FIG. 6 shows another embodiment of the bolt tightening device, in which the shapes of the bolt tightening part 1 and washer 3 in the embodiment shown in FIG. 1 are modified, and FIG. Another embodiment of the tightening device using a nut is shown, in which the shapes of the bolt tightening part 1 and the washer 3 in the embodiment shown in FIG. The washer 14 interposed in the head piece 13 is omitted, and the head piece 13
A protrusion 15 for preventing loosening is formed on the inner surface. Furthermore, FIGS. 8 and 9 show other embodiments of the tightening device using bolts and nuts, and the slope direction of the serrated projections 6, 7 on the back surface of the washer 3 is shown in FIGS. 6 and 7. The operation details in each of the embodiments shown in FIGS. 6 to 9 are shown in FIGS. 1 and 3. There is no difference from the example.

In this way, according to the present invention, the tightening portion 1 of the screw
Since serrated protrusions 4, 5, 6, and 7 with special characteristics are formed on the front and back surfaces of the washer 3 used in combination with the washer 3, the screw turns smoothly in the tightening direction during use, but the tightening work is difficult. After tightening, the rotation of the washer 3 and the screw in the direction of loosening is reliably prevented, which has the effect of reliably preventing the tightened part from loosening due to vibration, etc., and the tightened part of the structure. Suitable for preventing loosening.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a side view of the invention applied to a bolt, Fig. 2 is a cutaway side view thereof, Fig. 3 is a side view of the invention applied to a nut, and Fig. 4 is a side view of the invention applied to a bolt. 5 are bottom views of the washer, and FIGS. 6, 7, 8, and 9 are side views showing other embodiments of the present invention. 1...Tightening part, 2...Tightening surface, 3...
Washer, 4, 5, 6, 7... Serrated projection.

Claims (1)

[Scope of utility model registration request] In a device in which a washer 3 is interposed between a tightening portion 1 of the screw and a tightening surface 2, the tightening portion 1 is provided with a serrated protrusion 4 having an upward slope in the direction of rotation when tightening the screw. The surface of the washer 2 facing the tightening part 1 is provided with serrated protrusions 5 that match the protrusions 4, and the back surface of the washer 2 facing the tightening surface 2 is provided with serrated protrusions 5 in opposite directions on both sides with the diameter line A in between. A screw loosening device comprising serrated protrusions 6 and 7 having sloped slopes.