JP2000104718A - Temporary fixing structure of nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temporary fixing structure of nuts that can avoid degradations of the working environment by welding, degradations in precision of threaded portions of nuts by deformation during temporary fixing, and corotation of the nuts during actual fixing reliably. SOLUTION: A nut 1 has a plurality of projections 2 on one face, and a mounting body 3 to which the nut 1 is temporarily fixed has a plurality of through-holes 4. When the projections 2 are inserted into the through-holes 4 where they deform plastically, the nut 1 is fixed in position temporarily. Each through-hole 4 has a tapering face fully or partly expanding out from a nut mounting surface 10 to the counter surface. Each projection 2 is made about a vertex of the hexagonal nut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial application field] Until the nut is fully fixed, it can be temporarily fixed to the adherend so that the nut does not fall off. In addition, it is possible to prevent the nut from rotating together with the permanent fixing. The present invention relates to a temporary fixing structure of a nut which hardly affects the accuracy of the nut in a temporary fixing step.

[0002]

2. Description of the Related Art A conventional temporary fixing structure of a nut is such that a nut is fixed to a surface to be adhered by projection welding, or a link-shaped seat 102 provided on one surface of a nut 101 as shown in FIG. Was penetrated through the adherend 103 and then spread out in the diameter direction.

[0003] In the case of welding a nut, the working environment is deteriorated due to noise, odor and the like generated by the welding, and rust prevention treatment is separately required after the welding of the nut. Further, problems such as deterioration of the working environment occur due to odor and the like generated during the rust prevention treatment.

On the other hand, the ring-shaped seat 102 is
In the case of expanding the diametral direction after having penetrated through 3, the screw diameter in the vicinity of the seat 102 may expand due to the press pressure for expanding the seat 102, which may affect the screw precision.
This is because, in this temporary fixing structure, the seat 102 and the screw are close to each other, and a relatively large pressing pressure is required to spread the seat 102.
This is because the vicinity of the seat portion 102 is deformed, and the screw portion is also deformed, thereby impairing the accuracy of the original screw. Also, in this temporary fixing structure, the center of the ring-shaped seat 102 and the center of the nut 101 coincide with each other. The frictional force between the expanded portion and the edge of the through hole serves as a drag. Therefore, when the spread of the seat 102 is not sufficient,
In some cases, the nuts 101 rotate together and hinder bolt tightening.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent the working environment from deteriorating due to welding, prevent the accuracy of the nut screw portion from being deteriorated due to the deformation at the time of temporary fixing, and prevent the deterioration during the final fixing. An object of the present invention is to provide a temporary fixing structure of a nut which can surely prevent the nut from rotating together.

[0006]

According to the present invention, a plurality of projections are formed on one surface of a nut, and the projections are inserted into a plurality of through holes formed in an adherend to which the nut is temporarily fixed. The nut is temporarily fixed by plastically deforming the projection in the hole. According to this structure, the plurality of protrusions formed on the nut are inserted into the through holes of the adherend, so that they serve as anchors, which prevent the bolts screwed to the nut from rotating together when tightened. it can. In addition, since the protrusion protruding from the nut is deformed, the influence on the screw portion of the nut is small, and deterioration of the accuracy of the screw portion can be reduced.

[0007] The through hole may be tapered so that the whole or a part of the through hole extends from the nut mounting surface to the opposite surface. By forming a taper in all or a part of the through-hole, the effect as a stopper when the projection is deformed and expanded in the diameter direction is increased, and the temporarily fixed nut is less likely to fall off.

[0008] A hexagon nut having a chamfer on one side only,
A protrusion may be provided near the vertex of the surface that is not chamfered. Since chamfering is not performed, a protrusion can be provided near the vertex. Further, by providing the protrusion near the apex, the protrusion can be separated from the screw portion, and the influence on the screw portion when the protrusion is deformed can be minimized. Further, the pitch circle radius between the projections is maximized, and the center of the pitch circle diameter and the center of the nut coincide with each other, so that the function of the projection as a detent can be maximized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. In the present invention, as shown in FIG.
A plurality of projections 2 are formed on one surface of the nut 1, and the projections 2 are respectively inserted into a plurality of through holes 4 formed in an adherend 3 to which the nut 1 is temporarily fixed. Is plastically deformed, and the nut 1 is temporarily fixed.

The nut 1 is a hexagonal nut made of steel. As shown in FIG. 2, only the front side is chamfered 5 and the back side is not chamfered. A protrusion 2 is formed near each vertex 6 of the hexagon nut on the back side. The shape of the projection 2 is cylindrical, and its diameter is about 2.5 times the height. In the case of the M12 pressed nut of this embodiment, the diameter is 2.5 mm and the height is 1 mm. The dimension ratio between the height and the diameter is determined according to the thickness of the adherend 3 and the required strength.
Various settings may be made.

The projections 2 are provided at every other three points of the vertexes 6 of the hexagon nut 1. The centers of the pitch circles 9 of the centers of the projections 2 coincide with the centers of the screw holes 8. In the M12 nut 1 of the present embodiment, the distance between the opposing vertices 6 and 6 of the hexagon nut is about 22 mm, but the center of the projection 2 is such that the pitch circle 9 has a diameter of 18 mm.
It is arranged so that it becomes. Therefore, the projection 2 is located near the apex of the hexagon nut 1 and can effectively act on the torsional force applied when the bolt is tightened into the hexagon nut 1. Further, the projections 2 are provided at three places around the screw holes 8, and the centers of the pitch circles 9 of the centers of the projections 2 coincide with the centers of the screw holes.
The nut does not become eccentric when the tightening torque is applied.

In the adherend 3, through holes 4 are formed at positions corresponding to the projections 2, respectively. In the present embodiment, three holes are provided around the hole through which the bolt passes. The inner surface of the through hole 4 is tapered so that its cross section increases from the adherend surface 10 toward the opposite surface.

The procedure for temporarily fixing the nut 1 will be described. First, the projections 2 of the nut 1 are inserted into the through holes 4 of the adherend 3 and arranged on the adherend surface 10. Next, from the opposite side,
The protrusion 2 is pressed to be plastically deformed. This plastic deformation is performed by driving a spike-shaped punch die 7 into the tip of the projection 2. At this time, the projection 2 expands in the radial direction. Further, since the spike-shaped punch die 7 is used, the projection 2 is deformed into a trapezoidal cross section that is enlarged from the base end to the tip end. Since the through hole 4 with which the projection 2 engages also has a tapered cross-sectional trapezoidal shape, it can be temporarily temporarily fixed securely without applying excessive force. In FIG. 1, the left projection shows a state before plastic deformation, and the right projection shows a state after plastic deformation.

Next, different embodiments will be described.
In the present embodiment, as shown in FIG. 3, a part of the inner wall of the through hole 4 is tapered. The taper is provided at a thickness of about 1/3 of the plate thickness from the surface opposite to the surface 3 to which the nut 1 is temporarily fixed. Correspondingly, the projection 2 of the nut 1 is formed so as to reach a height near the surface on the opposite side, that is, a height slightly lower than the plate thickness. The procedure for temporarily fixing the nut 1 is the same as in the above embodiment.

In the case where the thickness of the adherend 3 is large, if the taper is provided over the entire thickness as in the above embodiment, the inner diameter of the through hole 4 for fixing the projection 2 becomes smaller than the nut 1. The surface on the side opposite to the temporarily fixed surface 10 may be too large. In such a case, according to the temporary fixing structure of the present embodiment, since the taper is provided only near the surface, the inner diameter of the through hole 4 does not become too large due to the taper, and If only the portion is deformed, the taper and the shape match, so that the nut 1 can be temporarily and easily temporarily fixed.

In this embodiment, three projections are provided. However, the number of projections is not limited to three. For example, the projections may be provided at two vertices opposed to each other with the screw hole 8 interposed therebetween. Also, it may be provided at all the vertices of the hexagon nut.

[0017]

According to the first aspect of the present invention, a plurality of projections formed on the nut are inserted into the through holes of the adherend.
They can be used as anchors to prevent co-rotation when bolts screwed to the nuts are tightened. In addition, since the protrusion protruding from the nut is deformed, the influence on the screw portion of the nut is small, and deterioration of the accuracy of the screw portion can be reduced.

According to the second aspect of the present invention, by forming a taper in all or a part of the through hole, the effect as a stopper when the projection is deformed and expanded in the diameter direction is increased, and the through hole is temporarily fixed. The nuts are less likely to fall off.

According to the third aspect of the present invention, by providing the protrusion near the apex, the protrusion can be separated from the screw portion, and the influence on the screw portion when the protrusion is deformed can be minimized. it can. Further, since the pitch circle radius between the projections is maximized, the function of the projections as a detent can be maximized.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention.

FIG. 2A is a bottom view showing the nut of the present invention, and FIG.
Is a side view.

FIG. 3 is a partially cutaway side view showing a different embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a temporary fixing structure of a conventional nut.

[Explanation of symbols]

 Reference Signs List 1 nut 2 protrusion 3 adherend 4 through hole 6 vertex 10 adherend surface

Claims (3)

[Claims] 1. A plurality of projections are formed on one surface of a nut, and the projections are respectively inserted into a plurality of through holes formed in an adherend to which the nut is temporarily fixed, and the projections are plastically deformed in the through holes. A temporary fixing structure for a nut, characterized in that the nut is temporarily fixed. 2. The temporary nut according to claim 1, wherein the through hole has a taper formed so as to extend from the nut mounting surface side to the opposite surface side on all or a part of the through hole. Fixed structure. 3. The nut according to claim 1, wherein the nut is a hexagonal nut chamfered only on one side, and the projection is provided near a vertex of the hexagonal nut on the side not chamfered. Temporary fixing structure.