JP2001221217A - T nut - Google Patents

Abstract

(57) [Problem] To provide a T-nut having a structure for protecting a thread formed on a shaft portion. A hollow shaft-shaped shaft portion (11) and a shaft portion (1) are provided.
1 is a T-nut 10 formed as a pair with a metal material, and a threaded portion 13 is provided on the inner peripheral surface of the shaft portion 11.
Is provided with a protruding portion 15 on the shaft portion side, and the shaft portion 11 is provided.
By forming the spot facing portion 14 on the side of the front end opening, a structure is provided in which the threads of the screw portion 13 are not damaged even if the tip of the shaft portion 11 is deformed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a T-nut used for fixing various members, and more particularly, to a T-nut having a hollow cylindrical shaft and a flange provided at one end of the shaft. And a structure of the shaft portion in a T-nut formed as a pair with a metal material.

[0002]

2. Description of the Related Art As a conventionally used T nut 40, for example, as shown in FIG.
1 and a flange portion 42 provided on one end side of the shaft portion 41.
And a plurality of projections 43 formed on the flange 42 have been proposed. A screw portion 44 is provided on the inner peripheral surface of the shaft portion 41, and a screw member such as a bolt is configured to be screwable. In addition, the protrusion 43 is
And a claw formed by raising a part of the flange portion along the cut 45 formed at the bottom.

A T-nut having such a structure is used, for example, when fixing wood boards. That is, as shown in FIG. 6, the shaft portion 41 of the T nut 40 is inserted through the plate body 60 having the hole 61 formed therein, and the flange portion 42 is driven into the plate body 60 side. By doing
The projections 43 of the flange portion 42 bite into the plate body 60 and both are fixed. Then, another plate body 70 in which the hole 71 is formed is abutted against a surface of the plate body 60 opposite to the surface on which the T nut 40 is mounted, at a position where the holes are in contact with each other. Shaft part 4 of T nut 40 through 71
The plate members are fixed to each other by being screwed to the first member.

In the T-nut 40 having the above-described structure, a band-shaped metal plate (not shown) is fed along a progressive die, and a center portion of a flange forming position is subjected to press processing by drawing a plurality of times. After the shaft portion 41 is formed from the metal plate, the flange portion including the shaft portion 41 is pulled out from the metal plate, and then the threaded inner wall of the shaft portion of each of the extracted T nuts is threaded, and the nail is raised from the flange portion 42 to protrude. A part 43 is formed, and the product is completed through polishing, cleaning, and surface treatment steps.

[0005]

However, in the case of the T-nut 40 having the above structure, the T-nut 40 is attached to the plate 60 by driving the T-nut 40 into contact with each other during the manufacturing process or the transport process after the threading. In such a case, there is a problem that the tip of the shaft portion 41 is deformed, the thread inside the shaft portion is crushed (the screw portion 44 is deformed), and the screw member 50 cannot be screwed.

The present invention has been made in view of the above situation, and has a T structure having a structure for protecting a thread formed on a shaft portion.
The purpose is to provide nuts.

[0007]

According to a first aspect of the present invention, a hollow cylindrical shaft and a flange provided at one end of the shaft are made of a metal material. It is a T-nut formed in an objective manner, and is characterized by including the following configuration. A screw portion is provided on an inner peripheral surface of the shaft portion. The flange is provided with a projection that is convex toward the shaft. A spot facing portion is formed on the tip end opening side of the shaft portion.

According to a second aspect of the present invention, in the T-nut according to the first aspect, the inner diameter of the spot facing portion is larger than the diameter of the root of the screw portion.

According to the present invention, since the counterbored portion is formed on the tip end opening side of the shaft portion of the T nut, no thread is formed in this portion. It is not crushed and damaged.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A T-nut as an example of an embodiment of the present invention will be described with reference to FIGS. FIG. 2 is an explanatory plan view of a T-nut, and FIG.
FIG. 4 is an explanatory cross-sectional view of the T nut taken along line AA.

The T nut 10 is a shaft 1 having a hollow cylindrical shape.
1 and a disk-shaped flange portion 12 provided on one end side of the shaft portion 11. On the inner wall of the shaft portion 11, a screw portion 13 having a thread is formed.
A counterbore portion 14 is formed on the distal end side of the screw portion 13 as a step portion which is wider than the screw portion 13.

The spot facing portion 14 is formed in a drawing process performed subsequent to a drawing process (pressing process) of the shaft portion 11 in a manufacturing process of the T-nut 10 or in a cutting process after the shaft portion 11 is formed. Form. In addition, since the inner diameter of the spot facing portion 14 is formed to be wider than the diameter of the thread root of the thread portion 13, no thread is formed in the spot facing portion 14 at the time of engraving the thread on the inner wall of the shaft portion 11. It has become.

The flange 12 is provided with three protrusions 15 at equal intervals around the periphery thereof. These projections 15
Is formed by raising a part of the flange portion along the cut 16 formed in the flange portion 12.

According to the T-nut having the above structure, since the spot facing portion 14 is formed on the tip end opening side of the shaft portion 11, no thread is formed in this portion, so that the tip of the shaft portion 11 is deformed. Also, it is possible to prevent the threads of the screw portion 13 from being damaged.

Next, a method of manufacturing the T-nut 10 having the above structure will be described. FIGS. 3A and 3B are views showing each step in the method of manufacturing the T-nut 10. In a series of steps shown in the figure, a stripper plate 20 and a die plate (forming die) 30 arranged above and below a strip-shaped metal plate 17 are synchronized with each other so as to approach and separate from the metal plate 17. The respective steps are simultaneously performed in a state where the metal plate 17 is clamped by the die plate 30 and the stripper plate 20 (the state shown in the drawing), and after the step is completed, the die plate 30 and the stripper plate 20 are separated from each other. ,
This is performed by moving the metal plate 17 by a predetermined distance in the right direction in the drawing and sequentially moving each processed portion to the next step.

First, the formation position of the flange portion on the strip-shaped metal plate 17 is determined, and a plurality of drawing processes are performed at the center of the flange portion (FIG. 3A). At the time of this processing, in a state where the metal plate 17 is clamped between the die plate 30 and the stripper plate 20, the drawing punch 2
1a to 21d respectively press the metal plate 17 downward, and at the same time, the knockouts 31a to 31d
To come into contact with the tip surface of the Diplate 3
The zero casting surface 300 is a cylindrical shape having a uniform diameter, and is set so that the diameter decreases as the process progresses. Accordingly, the diameters of the drawing punches 21a to 21d also decrease gradually.

By this step, a hollow cylindrical portion 18 having a uniform diameter is formed at the center of the metal plate 17 at the flange portion forming position. At this time, the diameter of the cylindrical portion 18 is processed so as to be substantially equal to the diameter of the shaft portion 11 of the T nut 10.

Next, the metal plate 17 is formed by a die plate 30 having a casting surface 301 having a smaller diameter on the tip end side of the cylindrical portion 18 than the diameter on the other end side (the flange portion 2 side) and the stripper plate 20. While the clamp is clamped, draw punch 2 of uniform diameter
2 presses the metal plate 17 downward, and at the same time, the knockout 32 comes into contact with the front end surface of the metal plate.
Is formed to form a cylindrical portion 18 ′ whose tip side is thinner than the other end side (FIG. 3 (b)). The thin end portion of the cylindrical portion 18 ′ is a portion that will later become the spot facing portion 14 of the T-nut 10. Subsequently, the distal end surface 18a of the cylindrical portion 18 'is punched by a punch 23 and cut off from the cylindrical portion 18'.

Next, the die plate 30 and the stripper plate 20 having a uniform cylindrical casting surface 302 having a diameter substantially equal to the outer diameter on the opposite end side of the cylindrical portion 18 'are joined to the metal plate 17 by the metal plate 17.
In the clamped state, the pressing punch 24 and the tip widening punch 25 are brought into contact with each other, and at the same time, the knockout 33 is brought into contact with the tip of the cylindrical portion 18 '. Tip widening punch 25
Is an enlarged portion 2 having a diameter larger than the inner diameter of the cylindrical portion 18 '.
5a and a guide portion 25b having a diameter smaller than the inner diameter of the cylindrical portion 18 '.
It has a cylindrical shape with a diameter substantially equal to the inside diameter of 8 '.

By this step, the inner diameter of the distal end of the cylindrical portion 18 'is increased while maintaining the original thickness, while the cylindrical portion 1' is expanded.
Since the thickness and the diameter of the opposite end of 8 'hardly change, the thickness of the tip is smaller than that of the opposite tip and the outer diameter is uniform (shaft 11 having spot facing portion 14). Is formed. Next, the flange portion 12 is punched by a punch 26 and cut off from the metal plate 17.

Then, the flange portion 12 is gripped by a chuck or the like, and the inner peripheral surface on the distal end side of the shaft portion 11 excluding the spot facing portion 14 is subjected to thread cutting to form a screw portion 13. continue,
Cut part 1 of the flange part 12 along the cut 16
6, the protrusion 15 is formed, and the T nut 10 (FIG. 1) in which the shaft portion 11 having the screw portion 13 and the flange portion 12 having the protrusion 15 are formed as a pair with a metal material is completed. .

According to the above-described method for manufacturing the T-nut, the spot facing portion 14 is formed in the drawing process following the series of drawing processes for forming the shaft portion 11, so that the T-nut can be manufactured efficiently. . Further, after a series of drawing processes for forming the shaft portion 11, the tip of the inner wall of the shaft portion 11 is cut to remove the spot facing portion 1.
4 may be formed.

[0023]

According to the present invention, since the counterbore portion is formed on the tip opening side of the shaft portion of the T nut, no thread is formed in this portion, so that even if the tip of the shaft portion is deformed. The screw thread is not crushed, the screwing of the screw member to the shaft portion can be secured, and a highly reliable T nut can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view of a T-nut according to an example of an embodiment of the present invention.

FIG. 2 is an explanatory plan view of a T-nut according to an example of the embodiment of the present invention.

FIGS. 3A and 3B are process explanatory views showing a method for manufacturing a T-nut.

FIG. 4 is an explanatory perspective view of a conventional T-nut.

FIG. 5 is an explanatory sectional view of a conventional T-nut.

FIG. 6 is an explanatory cross-sectional view illustrating a mounting example of a T-nut.

[Explanation of symbols]

10 T nut, 11 Shaft, 12 Flange,
13: Screw part, 14: Counterbore part, 15: Projection part,
16 ... cut

Claims (2)

[Claims] 1. A T-nut formed of a metal material and having a hollow cylindrical shaft portion and a flange portion provided at one end of the shaft portion, wherein an inner periphery of the shaft portion is provided. A T-nut comprising: a threaded portion provided on a surface; a projection formed on the flange portion on the shaft portion side; and a counterbore portion formed on a tip end opening side of the shaft portion. 2. The T-nut according to claim 1, wherein an inner diameter of the spot facing portion is larger than a diameter of a root of the screw portion.