JPS6120325Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a nut with a washer.

Conventionally, nuts with washers were manufactured in 1973.
There is one proposed in No. 129. In this nut with a washer, the seat surface 2 of the nut 1 is formed into a convex spherical surface, as shown in FIG. Further, the outer edge of the washer 3 is relatively thin and has a curved portion 5 formed toward the object to be fastened. However, in such a structure, since the curved portion 5 is in approximately circular line contact with the object to be tightened at the initial stage of tightening the nut 1, the surface of the object to be tightened may be damaged, and the curved portion 5 may be formed relatively thin. Because of this, it is easily damaged by repeated stretching and cannot withstand repeated use. In addition, since the seat surface 2 and the nut receiving surface 4, which have the same spherical surface, are in close contact with each other, the tightening torque of the nut 1 is not transmitted to the washer 3 without loss, making it impossible to obtain sufficient tightening force. .

The present invention was made to improve the above-mentioned drawbacks, and the bottom of the washer is formed flat, the nut bearing surface is formed into a convex spherical surface, and the nut receiving surface of the washer is formed into a tapered shape. be. Therefore, the washer always makes surface contact with the object to be tightened, and does not damage or damage the surface of the object. Also, the bearing surface of the nut and the nut receiving surface of the washer are in line contact with each other, so the nut The tightening force is transmitted to the washer without loss and sufficient tightening force can be obtained.

Next, an embodiment of the nut with washer of the present invention will be explained based on FIG.

In FIG. 2, 10 is a nut and 11 is a washer. The nut 10 has a threaded hole 12 formed in its center, and the lower seat surface 13 is centered at an arbitrary point O on the central axis, and the upper flange 2 of the washer
It is formed into a convex spherical surface that is a part of a spherical shape with a diameter R that comes into contact with substantially the upper surface of the cylindrical lens 1. Further, a locking protrusion 14 is formed on the lower end surface of the seat surface 13 so as to protrude outward in a circumferential manner. This locking protrusion 1
4 consists of a thin bent portion 15 and a locking portion 16 having a substantially circular cross section at its tip. The washer 11 has a through hole 17 formed in the center thereof through which a bolt is inserted, and a nut receiving surface 18 in contact with the upper seat surface 13 faces toward the inside of the through hole 17 at a predetermined angle θ (e.g. The seat surface 19 is formed into a linear tapered surface (140 degrees) and is in substantially circular line contact with the seat surface 13, and the seat surface 19 that comes into contact with the object to be fastened is formed flat. . An engagement groove 20 is formed on the inner peripheral wall surface of the through hole 17, and an upper protrusion 21 is formed between the engagement groove 20 and the nut receiving surface 18. This upper edge 2
1 serves as an elastic body that engages with the locking protrusion 14 to prevent it from coming off, and also absorbs the tightening force when the nut 10 is tightened. A lower protruding edge 22 is also formed at the lower part of the engagement groove 20, and this lower protruding edge 22 is designed to prevent the upper protruding edge 21 from being deformed beyond the permanent deformation limit when the nut 10 is tightened. The locking portion 16 is adapted to come into contact with it.
In addition, when assembling the nut 10 and the washer 11, after inserting the substantially vertical locking protrusion 14 into the through hole 17 as shown by the chain line, bend the bent part 15 outward as a whole. expand to the state.

Because the invention of this application is constructed as described above, the seating surface of the washer is flat and will not damage the surface of the object being fastened, even if it is a soft material, and when vibration perpendicular to the axis is applied, the spherical surface of the nut displaces slightly with the vibration amplitude due to theoretical line contact with the inclined surface of the washer, and this sliding phenomenon has an effect of preventing the screw from loosening. This has been proven by many experimental results. Furthermore, since the nut is given freedom of movement in all axial directions relative to the washer, this freedom is effective in precise fastening when the screw axis is not exactly perpendicular to the fastening seating surface and the fastening seating surface is inclined (it is inclined in most cases). Furthermore, because of the line contact, the rotational position of the nut is maintained until the end in precise and accurate fastening,
This makes it easier to achieve positional accuracy and prevents the seat surface from sliding when tightening. Also, when tightening, the nut is urged by the deformable elastic upper flange, so the nut does not loosen and can always be tightened securely. Also, even if the nut is tightened too hard, the lower flange abuts against the tip of the locking projection of the nut, so the nut does not bite into the washer more than necessary, and the upper flange does not deform beyond the permanent deformation limit, providing other excellent effects.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional nut with washer, Figure 2
The figure is a sectional view showing an embodiment of the nut with washer according to the present invention. 10... Nut, 11... Washer, 12... Screw hole, 13... Seat surface, 14... Locking protrusion, 15...
...Bending part, 16...Locking part, 17...Through hole, 1
8... Nut receiving surface, 19... Bottom surface, 20... Engaging groove, 21... Upper projecting edge, 22... Lower projecting edge.

Claims (1)

[Scope of utility model registration request] In a nut with a washer, in which a washer is loosely fitted into the nut, the receiving surface of the washer is formed into a linear tapered shape, the bottom surface that contacts the object to be fastened is formed flat, and the inner wall of the central through hole is formed. an engaging groove is formed to have an elastically deformable upper protruding edge and a lower protruding edge that protrude inward, and the bottom surface of the nut abuts substantially the upper surface of the upper protruding edge of the washer. A locking protrusion is formed into a convex spherical surface with a diameter such that the locking protrusion is formed into a convex spherical surface with a diameter such that the locking protrusion is formed into a convex spherical surface with a diameter such that the locking protrusion is formed into a convex spherical surface with a diameter of A nut with a washer, characterized in that the locking protrusion is bent and expanded outward so as to be engaged with the engagement groove with a gap.