JPS6310932Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a blind nut tightening tool.
Especially regarding the nosepiece of the tool.

The front end surface of the nosepiece of a conventional blind nut fastening tool is formed as a flat surface, and this surface presses against the flange surface of the blind nut. A blind nut fastened to a panel or the like using a fastening tool of this conventional structure sometimes rotates with the bolt when the bolt is tightened and does not function as a fastening nut. This is because both the panel hole and the blind nut are circular, so resistance to rotation is low, and even if the tightening force between the nut flange and the expanded tubular portion is strong, the nut may rotate. Furthermore, in extreme cases, as shown in FIG. 1, a gap 3 may be formed between the panel 1 and the blind nut 2, and the rotation prevention force is even weaker than in a case without a gap.

In order to eliminate such problems, a fastening tool has been proposed in which a protrusion is provided on the front end surface of the nosepiece that protrudes forward and outward of the tool from a position corresponding to slightly outside the inner diameter of the hollow hole of the blind nut. . This tool penetrated the hollow hole of the blind nut while partially expanding it, so that the nut was secured against rotation in the panel hole and a favorable result could be obtained. However, even with this tool, if there is a large gap between the nut and the panel hole, the contact between the nut side surface and the panel hole will be
This can only be achieved with a nut portion that has an enlarged diameter, and as a result, the nut may become misaligned with respect to the panel hole, or the rotation prevention force may not be sufficient.

Therefore, the purpose of the present invention is to attach a blind nut to a mounting hole of a panel, etc. without causing misalignment.
Moreover, it is an object of the present invention to provide a blind nut tightening tool equipped with a nose piece that can be tightened so as not to rotate with respect to a mounting hole.

In order to achieve this purpose, according to the present invention,
Screw the mandrel onto a blind nut temporarily fastened to a panel, etc., and rotate or pull the mandrel with the front end of the nosepiece pushing against the flange surface of the blind nut to inflate the tubular part of the blind nut on the back side of the panel. In the blind nut tightening tool which tightens the blind nut to the panel by increasing the diameter of the blind nut, the front end surface of the nose piece includes an annular guide that protrudes forward of the tool and has a hole formed therein for the mandrel to pass through. There is provided a blind nut tightening tool, characterized in that the annular guide is integrally attached, the outer diameter of the base of the annular guide is larger than the hole diameter of the blind nut, and the tip is formed slightly smaller than the hole diameter of the nut. Ru.

According to the present invention, with such a nosepiece,
As the nut is tightened, the annular guide enters into the nut hole, and this entry expands the entire nut hole, causing the entire outer surface of the nut to come into pressure contact with the inner surface of the mounting hole of the panel, etc. Therefore, the nut can be installed accurately without coming off the axis of the mounting hole, and since the entire side surface of the nut is in surface contact with the inner surface of the panel hole, the frictional resistance is large, and the nut exerts a strong rotation prevention force against the panel. It will be tightened even if it is.

In an embodiment of the present invention, it is preferable that a plurality of protrusions projecting outward are provided on the outer periphery of the annular guide, and each protrusion tapers toward the tip. Since the protrusion partially protrudes further and this protruding portion bites into the panel hole, an even stronger rotation-preventing force can be applied.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, the blind nut 2 is temporarily fixed in the mounting hole 4 of the panel 1, and the mandrel 5 of the blind nut tightening tool is screwed into the female thread of the nut 2. Also, the nose piece 6 of the blind nut tightening tool is attached to the mandrel 5.
It is provided at the tip of the tool to support it.

In the present invention, on the front end surface 8 of the nose piece 6 that presses the flange 7 of the blind nut 2, an annular guide 1 is formed which projects forward (downward in FIG. 2) of the tool and has a hole 9 formed therein for the mandrel 6 to pass through.
0 is provided integrally. This annular guide is preferably integrally molded with the nosepiece 6 as shown. However, even if they are separate pieces, they may be fixed so as to align with the axes of the nose piece 6 and mandrel 5. The annular guide 10 is formed so that its outer diameter is larger than the hole diameter of the blind nut 6 in most of the portion from the root adjacent to the nosepiece 6 toward the tip. However, the tip of the guide is tapered from the large diameter portion, and the outer diameter of the tip is formed to be slightly smaller than the hole diameter of the blind nut, so that the tip can fit a little into the hole of the blind nut. It is preferable that the length of the annular guide 10 is slightly shorter than the thickness of the panel 1 plus the thickness of the flange 7 of the nut, thereby preventing the mandrel from misaligning with respect to the nut. It is screwed in without any problem.

3 and 4 show the state in which the blind nut 2 is fastened to the panel 1 by rotating or retracting the mandrel 5. When the female threaded portion 11 of the blind nut 2 is drawn in by the mandrel 5, the tip of the annular guide 10 of the nose piece 6 enters the hole of the blind nut 2, and then the large diameter portion of the guide 10 enters the hole of the blind nut 2. The nut enters into the thin-walled tubular portion 12 of the panel 1 while expanding its inner diameter and outer diameter over the entire circumferential surface, filling the gap 3 shown in FIG. The inner surface of the mounting hole 4 comes into pressure contact.
Furthermore, as the mandrel 5 is pulled in, the thin tubular portion 12 exposed on the back side of the panel 1 expands and deforms.
The nut 2 is buckled and fastened to the panel 1 by the buckled portion 13 and the flange 7. FIG. 4 shows a state in which the nut 2 is fastened to the panel 1, and the blind nut 2 is fastened while the outer surface of the tubular portion 12 is in pressure contact with the inner surface of the mounting hole 4 of the panel 1. Therefore, the gap 3 in Figure 1 is eliminated, and the misalignment between the nut and the mounting hole caused by this gap is eliminated.
Furthermore, the frictional resistance between the nut and the panel is large and the nut does not rotate relative to the panel.

5 to 7 show a second embodiment of the invention. In this embodiment, a plurality of (four in the figure) protrusions 15 are provided on the outer surface of the annular guide 10, protruding outward from the base to the tip.
They are placed at approximately equal intervals. Each protrusion 15 is preferably formed so that its height and width become tapered toward the tip, and it is preferable that the apex is formed to have a sharp point as shown in the figure. When the annular guide 10 provided with the protrusion 15 is inserted into the blind nut 2, the guide 10 expands a portion of the thin tubular portion 12 over the entire circumference, and the protrusion 15 further partially expands. Therefore, as shown in FIG.
The partial protrusion 16 will be strongly bitten into the mounting hole 4 of the panel 1 as it is, and the nut 2 will be fastened to the panel with an even stronger rotation-preventing force. Of course, in this example as well,
Due to the action of the annular guide, the nut can be installed in the panel hole without being misaligned.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an unfavorable relationship between the blind nut and the panel after tightening, and Fig. 2 shows how the blind nut is tightened using the blind nut tightening tool according to the first embodiment of the present invention. FIG. 3 is a side sectional view showing how the nut is tightened using the tool shown in FIG. 2, FIG. 4 is a side sectional view of the nut after tightening, and FIG. FIG. 6 is a side sectional view showing how the blind nut is tightened using the blind nut tightening tool according to the embodiment; FIG. 6 is a side sectional view of the nut after being tightened with the tool shown in FIG. 5; FIG. is a sectional view taken along line 7-7 in FIG. 1...panel, 2...blind nut, 4...
... Mounting hole, 5 ... Mandrel, 6 ... Nose piece, 7 ... Nut flange, 10 ... Annular guide, 11 ... Female thread part, 12 ... Thin wall tubular part, 1
5... Protrusion.

Claims (1)

[Claims for Utility Model Registration] 1. A mandrel is screwed onto a blind nut temporarily fixed to a panel, etc., and the front end of the nosepiece is pressed against the flange surface of the blind nut, and the mandrel is rotated or pulled in to open the panel. In the blind nut tightening tool, which tightens the blind nut to the panel by expanding the diameter of the tubular part of the blind nut on the back side, the front end surface of the nose piece has the mandrel inside the tool, which protrudes toward the front of the tool. An annular guide having a hole through which the blind nut passes is integrally attached, and the outer diameter of the base of the annular guide is larger than the hole diameter of the blind nut, and the tip is formed slightly smaller than the hole diameter of the nut. Blind nut tightening tool. 2. The blind nut tightening tool according to item 1, wherein a plurality of outwardly protruding protrusions are provided on the outer periphery of the annular guide, and each protrusion tapers toward a tip.