JP2729366B2 - Loose nut - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for tightening a member to be tightened by screwing on a screw rod such as a screw or a bolt.
The present invention relates to a loose cap nut that is not easily loosened even when subjected to vibration or impact.

[0002]

2. Description of the Related Art Generally, most of the coupling load generated when a nut is screwed on a threaded rod such as a screw or a bolt to tighten a member to be tightened is concentrated on a thread near an inlet of the nut. Therefore, there is a problem that the tightening load is limited in order to avoid concentration of stress at the beginning of the thread.

Therefore, a loose nut capable of solving this problem has been proposed. FIGS. 5 and 6 show the loose nut. The loose nut 1 is provided continuously with the cylindrical inner cylinder portion 2 having a female screw portion 21 on the inner peripheral surface, a curl portion 22 extending radially outward from the inner cylinder portion 2, and a curl portion 22. A cylindrical outer cylindrical portion 3 surrounding the inner cylindrical portion 2, a seat portion 31 protruding radially outward at a proximal end of the outer cylindrical portion 3, and a radially extending portion at a proximal end of the inner cylindrical portion 2. The seat portion 23 of the outer tube portion 3 and the seat portion 23 of the inner tube portion 2 have their seat surfaces 32 and 24 at the same level. Has become. The outer peripheral portion of the outer cylindrical portion 3 is formed in a shape that can be fitted with a tool such as a spanner, for example, a hexagon, like a general nut. The loose nut 1 is formed of a relatively thin metal sheet such as a stainless steel sheet.

As shown in the figure, in the loose nut 1, when the female screw portion 21 is screwed into the male screw portion 41 of the screw rod 4 such as a screw or a bolt and tightened to the member A to be tightened, the outer cylindrical portion 3 is formed. And seat surface 3 of each seat portion 31 and 23 of inner cylinder portion 2
2 and 24 come into contact with the member A to be tightened and press it. Therefore, the seat portion 31 of the outer cylindrical portion 3 exhibits the same locking effect as the washer portion of a general nut with a washer.

On the other hand, when the loose nut 1 is tightened to the member A to be tightened, the loose load nut 1 is pressed toward the member A to be tightened by the coupling load generated at that time. An axial reaction force is generated in the outer cylinder portion 3 via the portion 31, and this reaction force is transmitted to the inner cylinder portion 2 via the curl portion 22 as indicated by an arrow F1. Therefore, in the inner cylindrical portion 2, the distal end side (the curl 22 side) is most strongly urged in the radially decreasing direction, and the biasing force F2 in the radially decreasing direction gradually decreases from the distal end side to the proximal end side. The seat 23 of the inner cylinder 2
At this point, the seat portion 23 tends to be pressed by the member A to be tightened to increase its diameter.

For these reasons, according to the loose nut 1, the loosening action is exerted by reducing the diameter of the inner cylindrical portion 2 at the distal end, and the diameter is reduced from the distal end to the proximal end. There is an advantage that the coupling load is dispersed to some extent in a wide range in the axial direction due to the phenomenon that the biasing force F2 in the direction gradually decreases.

[0007]

However, in the loose nut 1 described with reference to FIGS. 5 and 6, the outer cylindrical portion 3 is continuously provided via the curl portion 22 to the inner cylindrical portion 2 having the seat portion 23. Since the seat 31 is continuously connected to the outer cylinder 3 and the female screw 2 is formed on the inner peripheral surface of the inner cylinder 2, it has a complicated structure. Forming from a relatively high elasticity metal sheet such as SPCC) or stainless steel sheet tends to be expensive due to great technical difficulties, and is provided in general cap nuts. Since such a blind portion cannot be integrally formed, the end portion of the screw rod 4 is exposed to the outside, and when used outdoors, the screw rod 4 is subject to wind and rain and is likely to deteriorate due to rusting and the like. Was problematic.

The present invention has been made in view of the above circumstances, and provides a loose cap nut constructed by assembling a plurality of members with each other. That is, the present invention divides a component member of the loose cap nut into a plurality of members, thereby forming a blind portion for preventing an end of a threaded rod which is a mating member from being exposed to the outside, and forming a female screw portion. It is an object of the present invention to provide a loose cap nut in which the connection load is uniformly distributed over a wide range in the axial direction.

[0009]

According to the present invention, there is provided an unscrewing cap nut comprising: an outer cylinder portion into which a tool is fitted; a seat portion projecting radially outward at a base end side of the outer cylinder portion; An outer body having a blind portion that closes the opening of the outer cylindrical portion at the distal end of the outer portion, and a female screw portion on the inner peripheral surface of the cylindrical portion, and the outer cylindrical portion of the outer body at the distal end of the cylindrical portion. A nut body having a flange portion fitted non-rotatably, a tubular portion inserted into a space formed between the exterior body and the tubular portion of the nut body, and a radially outer portion at a base end side of the tubular portion. And an intermediate member integrally provided with a seat portion projecting in the direction, the seat portion being overlapped with and fixed to the seat portion of the exterior body, and a tip end portion of the cylindrical portion in the intermediate member is directed radially outward. It is formed into a cylindrical expanded portion that swells out, and this expanded portion overlaps the flange portion of the nut body in the axial direction, and And Sokarada the nut member and the intermediate member is formed of a highly elastic metallic material, is that.

[0010] In the loose nut with this configuration, the female screw portion of the nut body is screwed to the threaded rod, and a tool is fitted to the outer cylindrical portion of the exterior body to perform a rotating operation such as a tightening operation or a loosening operation. .

When the loose cap nut is screwed into the threaded rod and fastened to the member to be tightened, the seat of the intermediate member comes into contact with the member to be tightened, and the seat exerts a locking action. I do.

In the state where the loose cap nut is screwed onto the screw shaft and fastened to the member to be tightened, the flange portion of the nut body presses the expanded portion of the intermediate member, thereby removing the expanded portion of the intermediate member. The part receives the force in the diameter reducing direction, the nut body is pressed by the force, and elastically deforms in the diameter reducing direction,
Tighten the male thread of the screw shaft. Since such a tightening operation is performed in the entire axial length of the cylindrical portion of the nut body, the coupling load is less likely to be concentrated at one location.

When the loose cap nut is screwed onto the screw shaft and fastened to the member to be tightened, the blind portion of the exterior body covers the end of the screw shaft.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vertical sectional view of a loose nut N which is an embodiment of the present invention, FIG. 2 is a plan view of the same nut N, and FIG. 3 is a line III-III in FIG. Sectional view along
FIG. 4 is a cross-sectional view showing a use state.

This loose nut N is composed of three members, an outer body 5, a nut body 6 and an intermediate member 7, which are formed of a highly elastic metal material having excellent rust resistance, such as a stainless steel plate. Have been.

The exterior body 5 includes an outer cylinder portion 51 into which a tool (not shown) is fitted, a circular flange-shaped seat portion 52 projecting radially outward at a base end of the outer cylinder portion 51, and the outer cylinder portion. A blind portion 53 that closes the opening of the outer cylinder portion 51 at the distal end side of the portion 51, and the outer cylinder portion 51 has a hexagonal shape in plan view,
3 has a hemispherical dome shape. In addition, a stepped portion 54 is formed at a boundary between the blind portion 53 and the outer cylindrical portion 51.
The exterior body 5 is manufactured by subjecting a stainless steel plate to drawing or the like.

The nut body 6 has a female screw portion 62 on the inner peripheral surface of a cylindrical portion 61. In addition, a flange 63 is provided on the distal end side of the tubular portion 61. The flange 63 has a hexagonal shape, and the flange 63 is fitted to the outer cylinder 51 of the exterior body 5 and cannot be rotated. The nut body 6 is manufactured by subjecting a cold-rolled steel plate (SPCC) or a stainless steel plate to pressing or rolling.

The intermediate member 7 includes a cylindrical tubular portion 71, and a circular seat 7 projecting radially outward at the base end side of the tubular portion 71.
2 are integrally provided, and a distal end portion of the tubular portion 71 is formed as a tubular expanding portion 73 bulging radially outward. Although the expanding portion 73 in the illustrated example has a slightly curved cross-sectional shape, the expanding portion 73 may be formed in a tapered shape that is not curved. This intermediate member 7 has a cylindrical portion 71
It is inserted into a space S formed between the outer cylindrical portion 51 of the outer body 5 and the cylindrical portion 61 of the nut body 6,
2 is superimposed on the lower side of the seat portion 52 of the exterior body 5, and further, the expanding portion 73 overlaps the flange portion 63 of the nut body 6 in the axial direction. The flange 52 of the exterior body 5 and the flange 72 of the intermediate member 7 are joined by spot welding at a plurality of positions in the circumferential direction. The intermediate member 7 is manufactured by subjecting a stainless steel plate to press working or the like.

In such a loose nut N, the flange 63 of the nut body 6 is clamped and held by the stepped portion 54 of the exterior body 5 and the expanded portion 73 of the intermediate member 7 in a state where there is no play. ing. Therefore, in the loose nut N, the exterior body 5, the nut body 6, and the intermediate member 7 are firmly and integrally connected.

The loose nut N configured as described above is
As shown in FIG. 4, the female screw portion 62 of the nut body 6 is screwed to the male screw portion 41 of the screw rod 4. Then, a tool such as a wrench is fitted into the outer cylindrical portion 51 of the outer body 5 and is fastened to the member A to be tightened.

When the loose cap nut N is tightened to the member A to be tightened, the seat 72 of the intermediate member 7 comes into contact with the member A to be pressed, and the seat 72 is provided with a general washer. Exhibits the same locking effect as nut washers and spring washers.

In the state of FIG. 4 in which the loose nut N is fastened to the tightened member A, the flange of the nut body 6 presses the expanding portion 73 of the intermediate member 7 as indicated by an arrow a. Is transmitted to the portion of the intermediate member 7 excluding the expanding portion 73 through the expanding portion 73 as indicated by an arrow b. Therefore, the intermediate member 7
The portion excluding the expanding portion 73 receives a force in the diameter reducing direction, and the cylindrical portion 61 of the nut body 6 is pressed by the force to elastically deform in the diameter reducing direction, thereby tightening the male screw portion 41 of the screw shaft 4. The effect of the diameter reduction of the portion of the intermediate member 7 excluding the expanded portion 73 affects the entire axial length of the cylindrical portion 61 of the nut body 6, so that the male screw portion 41 of the screw shaft 4 becomes the cylindrical portion 61 of the nut body 6.
Will be tightened by the whole. for that reason,
The coupling load does not concentrate on one place.

As shown in FIG. 4, when the loose cap nut N is screwed onto the screw shaft 4 and fastened to the tightened member A, the blind portion 53 of the exterior body 5 covers the end of the screw shaft 4. Screw shaft 4
Does not rust or be deteriorated by such rust.

[0024]

According to the loose nut according to the present invention, a rotating operation such as a tightening operation or a loosening operation can be performed with the same handling as the loose nut described in the conventional example. Not only does it have the same locking effect as the attached nut, but it also has the following remarkable effects.

That is, in a state where the loose nut is screwed to the screw shaft and tightened to the member to be tightened, the cylindrical portion of the nut body tightens the screw shaft over its entire length in the axial direction.
The coupling load is less likely to be concentrated at one location, so there is no room to be limited by the stress at which the fastening load is concentrated at one location.

When the loose cap nut is screwed onto the screw shaft and fastened to the member to be tightened, the end of the screw shaft is covered by the blind portion of the exterior body, so that the end of the screw shaft is protected from wind and rain. There is no danger of rusting due to exposure or deterioration due to such rusting, which is preferable from the viewpoint of aesthetics.
Also, in the loose cap nut of the present invention, the head of the screw rod such as a bolt is covered and hidden by the blind portion, so that there is no danger of being caught on the head of the screw rod.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a loose cap nut according to an embodiment of the present invention.

FIG. 2 is a plan view of the cap nut.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view showing a use state of the loose cap nut.

FIG. 5 is a half cross-sectional view showing a state in which a conventional loose nut is used.

FIG. 6 is a plan view of the same.

[Explanation of symbols]

 5 Exterior Body 6 Nut Body 7 Intermediate Member 51 Outer Cylindrical Part 52 Seat Part 53 Blind Part 61 Cylindrical Part 62 Female Thread Part 63 Flange Part 71 Cylindrical Part 72 Seat Part 73 Expanding Part S Space

Claims (1)

(57) [Claims] 1. An outer cylinder part to which a tool is fitted, a seat part protruding radially outward at a base end side of the outer cylinder part, and a blind end closing an opening of the outer cylinder part at a distal end side of the outer cylinder part. A nut body having a female thread portion on the inner peripheral surface of the cylindrical portion and a flange portion at the tip side of the cylindrical portion and non-rotatably fitted to the outer cylindrical portion of the outer body. A cylindrical portion inserted into a space formed between the exterior body and the cylindrical portion of the nut body, and a seat portion projecting radially outward at a base end side of the cylindrical portion, and the seat portion is integrally provided. An intermediate member that is overlapped and integrally fixed on the seat portion of the exterior body, and a tip end portion of the cylindrical portion of the intermediate member is formed into a cylindrical expanded portion that is bulged radially outward. The extended portion overlaps the flange portion of the nut body in the axial direction, and the exterior body, the nut body, and the intermediate member are made of a highly elastic metal. A loose cap nut formed of a material.