JPH09250524A - Self perforating and expanding insert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a large pull out resisting force which can bite sufficiently a thin board-like material to be demonstrated and to enable a member to be firmly fixed through an installation screw. SOLUTION: This insert is equipped with a drill part 2, a shaft part 3, a head part 6, a shaft hole 8 penetrating the center of the shaft and head parts, and a slit 9 in the shaft direction communicated with the shaft hole, and is constituted so that a member is fixed to a board-like material through an installation screw which is screwed to the shaft hole 8 by being screwed to one side of the board-like material. In this case, blades 4, 5 which follows the drill part 2 in two spiral shape and are projecting are provided on the outer periphery of the shaft part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-piercing expanding insert that is screwed into one side of a plate-like member and is fixed to the plate-like member by screwing a mounting screw into a central hole.

[0002]

2. Description of the Related Art Conventionally, as this type of insert, for example, one shown in FIG.
1934). The insert 31 has a plate-shaped triangular tip portion 32 and a shaft portion 3 having a quadrangular cross section (see FIG. 6C) continuous with the tip portion via tapered surfaces 33, 33.
4, a blade 35 protruding from the outer periphery of the shaft portion so as to form a single spiral, and a cross hole (not shown) into which the tip of the driver fits at the center of the upper surface following the shaft portion 34. Dish-shaped head 3
6 and a screw hole 37 provided in the center of the head portion 36 and the shaft portion 34 for screwing a mounting screw 38 (see FIG. 6B).

The insert 31 is a driver (not shown) fitted in the cross hole of the head 36, as shown in FIG. 6 (B).
The gypsum board 40 is rotated by the piercing action of the tip 32.
Screwed from one side of the
A mounting screw 38 that passes under the neck of a is screwed into the female screw hole 37 of the insert 31, and the member 41 is attached to the gypsum board 40.
Fix on one side of. The tip portion 32 of the insert 31 is
The tip of the gypsum board 40 includes the discharge of the shavings because the thin sword-shaped tip is in the diagonal direction of the shaft portion 34, and the tapered surfaces 33 on both sides are on the other diagonal side and smoothly connect to the shaft portion 34. Can be efficiently drilled, and the square shaft 34
Due to the boring action, the breakage area of the board due to boring is reduced as compared with the insert of the shaft portion having a circular cross section, and the pull-out resistance of the screwed insert can be increased.

[0004]

However, in the conventional self-piercing expanding insert 31 described above, since the screw thread 35 provided on the outer periphery of the shaft portion 34 is a single blade, the plate thickness of the gypsum board 40 is small. There is no problem if it is thick as shown in FIG. 6 (B),
When the thickness is thin as shown by the two-dot chain line in the figure, the thread 35 on the gypsum board 40 becomes one thread on only one side, and a sufficient pull-out resistance cannot be obtained. Member 41
There is also a problem that the fixing force of the above to the gypsum board 40 is insufficient.

Therefore, an object of the present invention is to devise the mode of the blades provided on the outer periphery of the shaft portion so that even a thin plate-like member can be bitten on both sides to exert a large pulling-out resistance without deviation and to be attached. It is an object of the present invention to provide a self-piercing expanding insert capable of firmly fixing a member to the plate-shaped member with screws.

[0006]

In order to achieve the above object, in the insert according to claim 1 of the present invention, a drill portion at a tip, a shaft portion following the drill portion, and a rotary shaft of a tool are fitted to each other. A head portion having a fitting hole that follows the shaft portion, a shaft hole that extends through at least the center of the shaft portion and the head portion, and a slit that extends in the axial direction and that communicates with the shaft hole. A self-piercing expanding insert screwed from one side of the plate-shaped material and fixing the member to the plate-shaped material through a mounting screw screwed into the shaft hole, wherein the drill is provided on the outer periphery of the shaft portion. It is characterized in that a blade protruding in a double spiral is provided so as to follow the part.

The insert according to claim 1 is rotated by a tool in which a rotary shaft is fitted in a fitting hole of a head, and a drill portion at a tip pierces a plate-shaped material from one side, and a shaft portion following the drill portion. While the outer peripheral blades bite into the plate-shaped material, they are screwed in until the head is embedded in the plate-shaped material. Next, when the mounting screw inserted under the neck into the through hole of the member is screwed into the shaft hole of the insert, as the tip of the mounting screw projects from the other surface of the plate-shaped material, The shaft surrounding the tip is
Open to expand to the left and right of the axial slit,
The blades on the outer periphery come into contact with the other surface of the plate-shaped member to press it, and when the mounting screw is tightened, the fixing of the member is completed. Since the blades on the outer periphery of the shaft portion are formed in a double-threaded spiral, even if the plate-shaped material is thin, the blades existing on both sides of the shaft portion of the plate-shaped material can be compared to the blades of the single-threaded spiral. A large pull-out resistance can be obtained without being biased by being bitten on both sides.

The insert according to claim 2 has a shaft portion,
A head part having a fitting hole into which the rotary shaft of the tool fits and continuing to the shaft part, a shaft hole penetrating the center of the shaft part and the head part over the entire length, and communicating with the shaft hole. Self-piercing for fixing a member to the plate-shaped material through a mounting screw screwed from one side of the plate-shaped material and provided with a slit that opens in the tip of the shaft-hole and extends in the axial direction. A widening insert, comprising a blade provided by cutting out the tip of the shaft portion, and a blade provided on the outer periphery of the shaft portion so as to protrude from the outer periphery of the shaft portion so as to form a two-thread spiral, The shaft portions on both sides in the circumferential direction of the slit extending in the axial direction are connected to each other by the blades near the tip of the shaft portion.

According to the insert of claim 2, the drill portion of the insert of claim 1 is omitted, and a blade at the tip of the short shaft portion is used, and the axial hole and the axial slit penetrate the entire length of the insert, and the slit is provided. The insert differs from the insert according to claim 1 in that the shafts on both sides in the circumferential direction are connected to each other by blades near the tip of the shaft. Therefore, claim 1
In addition to the actions and effects described in, since there is no long drill part protruding from the back surface of the plate-shaped material, even if there is a wall immediately behind the back surface, screw in the insert from the surface of the plate-shaped material, The member can be fixed via the mounting screw. In addition, the shavings of the plate-shaped material cut by the blade are smoothly discharged to the surface side of the plate-shaped material through the shaft hole, and good drilling is possible, and the vicinity of the tip of the axial portion of the axial slit is Since the blades are connected, the shaft does not open to the left and right at the slit when screwing in the insert, and the connecting part cuts and expands when the mounting screw is tightened thereafter. The screwing is guaranteed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. 1 and 2 are a front view, a plan view, a bottom view and a left side view, a right side view, and a partial detailed view of a blade, respectively, of an embodiment of a self-piercing expanding insert of the present invention. This self-piercing expanding insert 1 is made of zinc die-cast, and has a drill part 2 at the tip, a shaft part 3 following this drill part 2, and a two-row structure so as to follow the drill part 2 on the outer periphery of this shaft part 3. A dish-shaped head that continues from the shaft portion 3 and has a central cross-shaped groove 7 in which spiral blades 4 and 5 and a screwdriver bit 11 (see FIG. 4A) are fitted. 6, a shaft hole 8 extending through the centers of the shaft portion 3 and the head portion 6, and a part of the shaft portion 3 and the blades 4 and 5 are penetrated in a plane including the center line of the shaft hole 8. It is composed of a pair of axial slits 9.

The drill section 2 is shown in FIG. 1 (C) and FIG.
As can be seen from (B) and (C), the conical tip and the columnar part that follows it are divided into four in the circumferential direction, and the opposing pair is cut off to form a drill blade, and the center of the shaft part 3 ,
The shaft hole 8 and the axial slit 9 that penetrate the outer peripheral surface respectively open at the base of the drill portion 2 and are connected to the edge of the drill blade in the axial direction. As shown in FIGS. 3B and 3C, the shaft hole 8 is connected to the cross hole 7 at the center of the head 6 at the upper end,
The axial slit 9 is stopped by a circular hole in the shaft portion 3 near the upper ends of the blades 4 and 5. 3 (A) is the same right side view as FIG. 2 (B) of the insert 1, and FIG. 3 (B), (C)
FIG. 3B is a sectional view taken along the line bb and the line cc of FIG. 3A, that is, a sectional view seen toward the front side and the back side.

The blades 4 and 5 which are two-threaded spirals are shown in FIG.
As can be seen from (C) and FIGS. 2 (A) and (B), the start points 4a, 5a of the upper end of the edge of the drill blade, which is provided 180 ° out of phase with each other in the circumferential direction of the shaft portion 3, are provided. From 1st round points 4c, 5c through half round points 4b, 5b,
A cutout 9 ', which is an outward extension of the axial slit 9, is formed in 5b. The blades 4 and 5 have a sectional shape as shown in FIG.

The self-piercing expanding insert 1 having the above-mentioned structure is
It is used as shown in FIG. First, as shown in FIG. 4 (A), the insert 1 is erected at a place where the one-sided member 41 of the plate-shaped material such as the gypsum board 40 is to be attached, and the bit 11 at the tip of the rotary shaft of the screwdriver is lowered (see arrow X). Fit in the cross hole 7 (see FIG. 1B) of the head 6 of the insert. next,
When the bit 11 is rotated in the direction of arrow Y in FIG. 4 (B),
In the insert 1, the drill part 2 at the tip pierces the gypsum board 40, and the heads 6 are buried while the double-spiral blades 4 and 5 on the outer periphery of the shaft part 3 following the drill part 2 bite into the gypsum board 40. Screwed up.

Thus, the insert 1 becomes the gypsum board 40.
4C, the member 41 to be fixed to the gypsum board 40 is screwed into the shaft hole 8 of the insert 1 as shown by arrow Z in the member 41 to be fixed to the plaster board 40. Screw in using. As the mounting screw 12 is screwed in, as shown in FIG. 4 (D), the shaft hole 8 is expanded and the drill portion 2 and the shaft portion 3 are separated from each other by the axial slit 9
When the head of the mounting screw 12 is buried in the through hole 41a and the tightening is finished, the left and right blades 4, 5 of the shaft portion 3 on the back surface of the gypsum board 40 are It abuts against the back surface and presses them. As can be seen from FIGS. 3B and 3C, the cross hole 7 of the head 6 of the insert 1 has a conical shape matching the bit 11, so that the mounting screw 12 inserted into the shaft hole 8 Also plays a role of guiding.

The blades 4, 5 on the outer circumference of the shaft of the insert 1 are
Gypsum board 40 because it is formed with a double-strand spiral
Is about half as shown in the figure, the blades 4 and 5 on both sides of the shaft portion 3 are larger than the conventional single-thread spiral blade 35 (see FIG. 6). Exhibits withdrawal resistance, and therefore the member 41 is attached to the mounting screw 12
It is firmly fixed to the gypsum board 40 via. If the blade bites only on one side of the shaft, the blade will be inclined with respect to the pulling force and a large pulling strength cannot be obtained. In this embodiment, the shaft hole 8
Since the slit 9 extending in the axial direction communicating with the member 41 is provided by the contact and pressing of the blades 4 and 5 on both sides with respect to the back surface of the gypsum board 40, the member 41 is inserted through the insert 1 and hence the mounting screw 12. Has the advantage that it can be more firmly fixed to the gypsum board 40.

FIG. 5 is a front view, a right side view and a bottom view, respectively, of another embodiment of the self-piercing expanding insert of the present invention. In this insert 21, the drill portion 2 of the insert described in FIG. 1 is omitted, and the tip of the shaft portion 3 is cut out so as to face each other by ¼ circle to form a short blade 22.
(See (C)) the center of the insert is penetrated over the entire length, and the shaft portions 3 on both sides in the circumferential direction of the slit 9 in the axial direction have blades 4a, 5a near the tip of the shaft portion (Fig. 5 (B)). , (C)), which is different from the insert of FIG. Therefore, the same members as those in FIG.

Therefore, in addition to the functions and effects described for the insert of FIG. 1, the insert 21 does not have a long drill portion projecting from the back surface of the plaster board 40 (see FIG. 4), so that the wall surface immediately behind the back surface. Even if there is
The member 21 can be fixed via the mounting screw 12 by screwing the insert 21 from the surface of the gypsum board 40. Further, the shavings of the gypsum board scraped by the blade 22 are smoothly discharged to the surface through the shaft hole 18 penetrating the center of the insert, and good perforation can be performed. Furthermore, since the vicinity of the tip of the axial portion of the slit 9 in the axial direction is connected by the blades 4a and 5a, the axial portion 3 does not open to the left and right at the slit 9 when the insert 21 is screwed in. Since the above-mentioned connection is broken and expanded only when tightened, reliable screwing of the insert 21 is guaranteed.

Although the insert is made of zinc die cast in the above embodiment, it may be made of synthetic resin. Further, the plate-shaped material into which the insert is screwed is not limited to the plaster board described above, but may be a plywood board, a concrete block, or an ALC plate.

[0019]

As is apparent from the above description, the self-piercing expanding insert according to claim 1 of the present invention has a shaft hole that penetrates the drill part, the shaft part, the head part, the shaft part, and the center of the head part. And a slit in the axial direction communicating with the shaft hole, which is screwed into one surface of the plate-shaped member and which fixes the member to the plate-shaped member through a mounting screw screwed into the shaft hole. In the case of a thin plate-like body, as compared with the conventional insert having a single-thread spiral blade, since the blade that protrudes in a double-thread spiral so as to follow the drill section is provided on the outer periphery of the shaft section, Even if it is, the blades on both sides of the shaft firmly engage with the plate-shaped material on both sides of the shaft, and the shaft protruding from the back surface of the plate-shaped material moves to the left and right of the slit as the mounting screw is tightened. It opens so that it expands, and the outer peripheral blades come into contact with and press against the above-mentioned back surface, so a large pull-out resistance is exhibited. Member can be very firmly fixed to the plate-shaped member.

According to a second aspect of the present invention, in the self-piercing expanding insert, the insert of the first aspect is omitted, and a blade having a short shaft end is used as a blade, and the shaft parts on both sides in the circumferential direction of the slit opening at the front end of the shaft hole. Since the blades are connected to each other by the blades near the tip of the shaft, the insert can be used even in the case where the back space of the plate-shaped material is narrow due to the absence of a large drill, and in addition to the effects described above, the blade can also be used to cut the fragments. The insert does not open when screwing the insert, thanks to the connection of the axial slits by the blades, which is well discharged to the outside through the shaft hole to promote drilling and cuts only when tightening the mounting screw. The secure screwing of is guaranteed.

[Brief description of the drawings]

1 (A), (B) and (C) are a front view, a plan view and a bottom view, respectively, of an embodiment of a self-piercing expanding insert of the present invention.

FIGS. 2A and 2B are views taken along the line IIa-IIa and line IIb-IIb of FIG. 1A, respectively, and FIG. 2C is a detailed cross-sectional view of the blade. .

3A is a right cross-sectional view of the same insert as in FIG. 2B, and FIGS. 3B and 3C are cross-sectional views along line bb and c- of FIG. 3A, respectively.
It is a c line sectional view.

FIG. 4 is a diagram showing a fixing procedure of a member using the insert of FIG.

5 (A), (B) and (C) are a front view, a right side view and a bottom view, respectively, of another embodiment of the self-piercing expanding insert of the present invention.

6 (A), (B), and (C) are a front view, a state-of-use sectional view, and a transverse sectional view, respectively, of a conventional insert.

[Explanation of symbols]

1, 21 ... Insert, 2 ... Drill part, 3 ... Shaft part, 4, 5
... Blade, 6 ... Head, 7 ... Cross hole, 8,18 ... Shaft hole, 9 ...
Axial slit, 9 '... Notch, 11 ... Bit, 12 ...
Mounting screw, 22 ... Blade, 40 ... Gypsum board, 41 ... Member.

Claims (2)

[Claims] 1. A drill part at the tip, a shaft part following the drill part, a head part having a fitting hole into which a rotary shaft of a tool fits and continuing to the shaft part, and at least the shaft part and the head part. A shaft hole extending through the center of the part, and an axially extending slit communicating with the shaft hole are provided, screwed from one side of the plate-shaped material, and through a mounting screw screwed into the shaft hole. A self-piercing expanding insert for fixing a member to the plate-shaped material, characterized in that a blade protruding in a double-screw spiral is provided on the outer periphery of the shaft portion so as to follow the drill portion. Perforation expansion insert. 2. A shaft part, a head part having a fitting hole into which a rotary shaft of a tool is fitted, the head part continuing to the shaft part, and a shaft hole penetrating the shaft part and the center of the head part over the entire length. And a slit extending in the axial direction that communicates with the shaft hole and opens at the tip of the shaft hole, is screwed from one surface of the plate-shaped material, and the member is attached via a mounting screw screwed into the shaft hole. A self-piercing expanding insert fixed to the plate-shaped member, wherein a blade provided by cutting out a tip of the shaft portion and an outer periphery of the shaft portion are formed with a double-strand spiral so as to follow the blade. A self-piercing expanding insert, characterized in that the shaft portions on both sides in the circumferential direction of the slit extending in the axial direction are connected to each other by the blades in the vicinity of the tip of the shaft portion.