JPH10339314A - Drill screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drill screw without decreasing fixed strength and without inferiority even in the point of driving thrust, in the case of fixing a face bar formed by plywood to a steel-made frame or the like. SOLUTION: A drill screw has a head part 11 enabled to engage with a rotary tightening tool, shaft part 12 extended downward from the head part 11, and a drill part 13 formed in a tip end of the shaft part 12. The shaft part 12 is formed by a first thread ridge forming part 15 formed with a thread ridge 15a from a lower end of the head part 11, thread ridge non-forming part 16 arranged under this first thread ridge forming part 15 to be formed with no thread ridge, and a second thread ridge forming part 17 formed with a thread ridge 17a by a degree of about 1.5 pitch under this thread ridge non- forming part 16. A length in an axial direction of the thread ridge non-forming part 16 is formed equal to or longer than a thickness of a fastened face bar.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a drill screw for fastening and fixing a face member made of a wooden plywood or the like to a steel frame or a steel structure, for example. The present invention relates to an improvement in a drilling tapping screw capable of drilling a pilot hole in two members different from each other, performing tapping, and tightening both members.

[0002]

2. Description of the Related Art FIG. 4 shows a drill screw with a reamer of this type, in which (A) is an overall front view, and (B) is a wooden plywood face material fastened to a steel channel material. FIG. 3C is a cross-sectional explanatory view showing a state of attachment, and FIG. The drill screw 50 with the reamer is provided with a head 51 that engages with the rotation engaging portion of the rotary tightening tool.
A shaft portion 52 extending downward from the head portion 51, a drill portion 53 provided at a lower distal end portion of the shaft portion 52, and a reamer 54 provided at a base end side of the drill portion 53, Tapping and tightening screw threads 55 are formed on the shaft portion 52, and the reamer 54 is formed of a small plate-like projection, and is formed at two symmetrical positions using the center line of the shaft portion 52 as a line symmetric reference line. Is what is being done. The outer diameter of the drill portion 53 is larger than the outer diameter (trough diameter) of the shaft portion 52, and
Is smaller than the outer diameter (peak diameter). The outer diameter of the reamer 54 is larger than the diameter of the thread 55. A cross-shaped groove or a slot is formed on the upper end surface of the head 51 so as to be able to engage with the rotation engagement portion of the rotary tightening tool.

FIGS. 4 (B) and 4 (C) show a state in which a face material made of wooden plywood is fastened to a steel channel material by the drill screw with the reamer. First, a face material 80 made of a wooden plywood is joined to a steel channel material 70, and the reamed drill screw 50 is driven from above using a rotary tightening tool. At first, the drill 53 at the tip of the drill screw 50 is
Drill a pilot hole at 0. Thereafter, the reamer 54 further cuts the inner peripheral surface of the prepared hole, and pierces the hole so as to form a larger inner diameter.

As a result, the inner diameter of the pilot hole 81 is reduced
Is formed to be larger than the outer diameter of
Will not engage with the inner peripheral surface of Therefore, when the tip of the drill portion 53 of the drill screw 50 reaches the channel material 70 and starts drilling, it is possible to prevent the face material 80 from floating. Because thread 5
5 forms a thread groove in the prepared hole 81 and is engaged with the prepared hole 81, the drill portion 53 reaches the channel material 70 made of a harder material, and the channel material 70
When drilling a pilot hole, since the drilling speed is naturally lower than the speed of drilling the pilot hole in the face material 80, the face material 80 moves in a direction away from the channel material 70 by the rotation of the drill screw 50, This is because it will rise from the channel material 70. Reamer 54
In order to prevent such a floating phenomenon of the face material 80, the inner diameter of the prepared hole 81 of the face material 80 functions so as to be larger than the thread diameter of the thread 55.

[0005] Then, while the pilot hole 81 having an inner diameter larger than the outer diameter of the thread 55 is formed by the reamer 54, the tip of the drill portion 53 comes into contact with the channel member 70 this time,
Drilling of a pilot hole in this channel material 70 is started. When the reamer 54 comes into contact with the channel material 70, the reamer 54 is broken by the channel material 70 made of a hard material. Thereafter, the drill screw 50 is fastened to the channel material 70, and the face material 80 is It is fastened and fixed to the material 70.

FIG. 5 shows another type of conventional drill screw 60, in which (A) is an overall front view, and (B) is a face plate made of wooden plywood fastened to a steel channel material. FIG. 3C is a cross-sectional explanatory view showing a state of attachment, and FIG. The drill screw 60 has a head 61 that engages with a rotational engagement portion of the rotary tightening tool,
The shaft portion 62 extends downward from 1 and a drill portion 63 formed at the lower end of the shaft portion 62. The length of the shaft portion 62 is longer than that of a normal shaft portion. A thread forming section 65 in which an upper thread 65a is formed;
And a thread non-forming portion 66 where no thread is formed. Here, the drill 63
Is larger than the outer diameter (trough diameter) of the shaft portion 62 and smaller than the thread diameter of the thread 65. On the upper end surface of the head 61, a cross-shaped groove or a slot is formed so as to be able to engage with the rotation engaging portion of the rotary tightening tool.

FIGS. 5B and 5C show a state in which a face material made of a wooden plywood is fastened to a steel channel material by the drill screw 60. FIG. First, a face material 8 made of wooden plywood is placed on a steel channel material 70.
0, and the drill screw 60 is driven from above using a rotary tightening tool. At first, drill screw 6
The drill portion 63 at the leading end of the hole 0 drills a prepared hole in the face material 80. Following the drilling of the pilot hole in the face material 80, the drill portion 63 drills the pilot hole in the channel member 70, which is now made of a harder material. The perforation speed rapidly declines at the stage of transition from the face material 80 to the channel material 70. At this time, the thread non-forming portion 66 of the shaft portion 62 of the drill screw 60 is located at the site of the prepared hole formed in the face material 80, and the thread non-forming portion 66 is located at the face material 8.
In other words, in the inside of the lower hole of No. 0, it turns to be idle, so that the face material 8
0 never rises. Therefore, using the drill screw 60, the face material 80 is formed into the channel material 70.
When fastening and fixing the shaft member 62, it is necessary to select and use a member in which the length of the threadless portion 66 of the shaft portion 62 is longer than the thickness of the face member 80. Then, drill screw 60
Drills a pilot hole in the channel material 70, performs tapping and tightening, and fastens the face material 80 to the channel material 70,
It can be fixed.

[0008]

The above-mentioned conventional drill screw has the following problems. In the drill screw 50 with a reamer shown in FIG.
Forms a prepared hole 81 in the face material, and the inner diameter of the prepared hole 81 is formed larger than the diameter of the thread 55 of the shaft portion 52. As a result, the face material becomes the shaft portion 5 of the drill screw 50.
2 and the thread 55 are fixed with a certain gap. Therefore, the holding force against the shear stress in the direction orthogonal to the axial center of the drill screw 50 is reduced. That is, the fixing strength is weakened. Compared to a regular unreamed drill screw,
It decreases by about 20%.

On the other hand, in the case of the drill screw 60 shown in FIG. 5, there is no problem of lowering the fixing strength as compared with the above-mentioned drill screw 50 with reamer.
When a pilot hole is formed in the channel member 70 made of a harder material, a non-thread forming portion 66 in which the shaft portion 62 is not provided with the thread 65 is formed by a lower hole in the face material 80. No forward thrust is added to the rotational force of the drill screw 60 at all, and the channel material 70
There is a problem that a considerable amount of forward pressing force (strike force) is required to make a pilot hole. In other words, when a thread is provided in the entire shaft portion 62 and a thread groove is formed in the lower hole of the face material, the driving force of the drill screw is used to guide the driving force of the drill screw into the forward driving thrust. However, since no thread groove is formed in the prepared hole of the face material 80, the non-threaded portion 66 of the shaft portion of the drill screw 60 is formed in the prepared hole.
Is located, so that a forward driving thrust cannot be obtained. The point that this forward driving thrust cannot be obtained is the same in the drill screw 50 with the reamer shown in FIG. Therefore, in the present invention, in order to solve the above-mentioned problems, the first problem is not to decrease the fixing strength of the two members to be fastened and fixed. It is an object of the present invention to provide a drill screw which is not so inferior in point.

[0010]

In order to solve the above-mentioned problems, a first aspect of the present invention is a head 11 capable of engaging with a rotary tightening tool, and a shaft extending downward from the head 11. 12
And a drill portion 13 formed at the tip of the shaft portion 12. In a drill screw having a tapping and tightening screw thread formed on the shaft portion 12, the shaft portion 12 is formed on the head 11 side. A first thread forming portion 15 on which a thread 15a is formed;
A thread non-forming portion 16 in which no thread is formed over a range of a predetermined length below the first thread forming portion 15;
A drill screw comprising a second thread forming portion 17 in which a thread 17 a of at least about one pitch is formed below the thread non-forming portion 16. In this case, the thread of about one pitch means that the helix of the thread is provided about one round in the case of a single thread, and for example, in the case of a two thread, It means a screw thread provided with a thread helix line of about 1/2 circumference. That is, it means that the thread is provided on the outer periphery of the shaft portion for about one round of the circumference, regardless of whether it is a single-start thread or a multi-start thread. According to a second aspect of the present invention, in the first aspect, the axial length of the threadless portion 16 is set to be equal to the thickness of an object to be fastened such as a wooden surface material to be fastened to a steel structure or the like. It is characterized by being substantially the same or longer than its thickness.

In the present invention, a thread 17a of at least about one pitch is formed on a shaft portion on the base end side of the drill portion 13, and a thread portion having no thread is formed on a portion of the shaft portion above it. Since there is the non-formed portion 16, for example, when fastening and fixing a face material made of a wooden plywood to a steel channel material, the drill portion 13 first makes a prepared hole in the face material, and then makes a hole in the channel material. When drilling the pilot hole, the face material is lifted up by the axial length of the portion between the drill portion 13 and the screw thread 17a due to the thread 17a provided on the base end side of the drill portion 13. Will stay at this length. This is because no thread is formed on the shaft portion above the thread 17a.
In addition, no gap is formed between the prepared hole formed in the face material and the shaft of the drill screw. As will be described later in detail, after the face material is fixed to the channel material at several points, if the face material is further tightened and fixed by the drill screw, the face material does not rise, so a pilot hole is formed in the face material. When a pilot hole is drilled and then a pilot hole is drilled in the channel material, the screw thread 17a is in a state of idling in the pilot hole of the face material. A gap is formed between the shaft portion and the inner peripheral surface of the pilot hole. However, since the gap can be formed only in a very small area, there is no problem with the fixing strength.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 illustrate an embodiment of the present invention. FIG. 1 is a front view of a drill screw 10 according to the present invention. This drill screw 10
Is a head 11 that engages with the rotation engagement portion of the rotary tightening tool;
A shaft portion 12 extending downward from a lower end of the head portion 11;
2 at the lower end.
The head 11 has a dish shape, but this shape can be designed quite freely. Although not shown in the drawing, a cross-shaped groove is formed on the upper end surface of the head 11, and can be engaged with the tip of the rotation engagement portion of the rotary tightening tool. Also, on the outer peripheral surface of the head 11, a plurality of protruding ridges 11a
Is formed, but this may be arbitrarily provided as needed.

The shaft portion 12 is formed to be longer than a normal drill screw, and is formed from three parts. That is,
First thread forming section 1 on which uppermost thread 15a is formed
5, a thread non-forming portion 16 in which no thread is formed below, and a second thread in which a thread 17a thereunder is formed.
And a thread forming portion 17. The entire outer diameter (trough diameter) of the shaft portion 12 is the same, and the thread 15a and the thread 17a are formed with the same lead angle and the same pitch, and the helix wire of the same thread is formed. Are formed on the locus of The axial length of the first thread forming portion 15 is manufactured in various lengths in consideration of the thickness of the two members to be fastened. In use, the length of the first thread forming portion 15 may be longer than the thickness of a face material made of a wooden plywood or the like fastened to a steel channel material or the like.

Although the thread 17a is shown in the drawing for about one and a half pitches, the thread 17a has a pitch of about one to three pitches. It is sufficient that about three to three turns are provided. The thread 17a may be appropriately set as needed according to the thickness and hardness of the face material to be fastened. The axial length of the thread non-formed portion 16 is manufactured in various lengths in consideration of the thickness of the face material to be fastened. The axial length of the non-threaded portion 16 may be the same as or longer than the thickness of a face material made of a wooden plywood or the like fastened to a steel channel material or the like. At the time of use, the length of the thread non-formed portion 16 may be equal to or longer than the thickness of the face material to be fastened.

The drill portion 13 may be the same as a conventional drill screw, and two cutting grooves 13a are provided symmetrically with respect to the center line of the shaft portion, and the cutting blade 13 is provided at the edge of the cutting groove.
b is formed. The outer diameter of the drill part 13 is larger than the outer diameter (trough diameter) of the shaft part 12 and
7a is formed smaller than the peak diameter.

FIG. 2 is an explanatory view showing a state in which a face material made of a wooden plywood is fastened and fixed to a steel channel material by a drill screw 10 according to the present invention.
Shows a state in which the face material is joined to the channel material and a prepared hole is drilled in the face material, and (B) shows the state immediately after the prepared material is formed in the face material and immediately before the prepared hole is formed in the channel material. State,
(C) shows a state in which a pilot hole is formed in both the face material and the channel material, and the drill screw is tightening.

First, in FIG. 2A, a face member 80 made of a wooden plywood is joined to a steel channel member 70, and a drill screw 10 according to the present invention is driven from above. The drill portion 13 of the drill screw 10 makes a prepared hole in the face material 80, and the screw thread 17a above it drills a female screw thread groove 80a in the prepared hole. 2 (B), a pilot hole is completed in the face material 80, and the incision of a female screw is completed in the inner peripheral surface of the pilot hole. FIG. 70 shows a state in which a pilot hole is started to be drilled. Here, channel material 70 is face material 8
Since the drill screw 10 is made of a material harder than 0, the drilling speed of the drill screw 10 sharply decreases. Therefore, drill screw 10
In the figure, the degree of advancing downward in the figure is reduced, so that the rotation of the drill screw 10 relatively moves the face material upward in the figure. That is, the face material 80 floats upward. However, since the thread 17a is provided with only about 1.5 pitches, the lifting is only required to be about the axial length between the drill portion 13 and the second thread forming portion 17, and FIG. With the degree of lifting shown in B), the lifting stops.

Next, as shown in FIG. 2C, a pilot hole and a female screw groove are completely formed in the channel material 70,
Further, when the drill screw 10 is driven as it is, the screw thread 15a is screwed into the screw groove 80a formed in the inner peripheral surface of the prepared hole of the face material 80, and the face material 80 and the channel material 70 are screwed.
The tightening is performed. As described above, the drill screw 10 can fasten and fix the face material 80 to the channel material 70, and can be securely fixed without forming a gap or the like between the screw shaft portion 12 and the face material 80. However, the fixing strength does not decrease.

FIG. 3 is an explanatory view showing a state in which the drill screw according to the present invention is driven into the face material and the channel material after several places have already been fastened by the drill screw according to the present invention. (A) shows a state in which a pilot hole has been drilled in the face material, the tip of the drill portion has reached the channel material, and drilling has started, and (B) shows the fastening of the face material and the channel material. 2 shows a state in which is completely completed. In the case shown in this figure, since fastening and fixing have already been performed at several places with the drill screw, even when a force such that the face material is lifted when driving the drill screw is applied, The face material is in a state where it does not float.

In FIG. 3A, since the channel material and the face material have already been fastened, the drill screw 10 drills a pilot hole sequentially from the face material 80 to the channel material 70. The face material 80 is made of wooden plywood, and the channel material 70
Is made of steel, when the drill portion 13 starts drilling a prepared hole in the face material 80 and then starts drilling a prepared hole in the channel material 70, the drilling speed is rapidly reduced because the channel material 70 is hard. Thereby, the drill screw 10
Is in a state in which the shaft part is idle. For this reason, the thread 17a is idle in the prepared hole of the face material 80, so that the inner diameter of the prepared hole is large at that portion. That is, the inner diameter of the lower hole 85 is substantially the same as the diameter of the thread 17a. While maintaining this state, the pilot hole of the channel material 70 is drilled.

After the pilot hole of the channel member 70 is formed and the screw thread 17a forms a thread groove in the pilot hole, the drill screw 10 is further driven in, so that the face material 8 is formed.
0 is fastened and fixed to the channel material 70 (FIG. 3B). As can be seen from FIG. 3B, the inner diameter of the prepared hole 85 of the face material 80 is formed large, and a gap is formed between the shaft member 15 and the shaft member 15. As described above, the face material 80 is partially changed by the drill screw into the channel material 70.
When the drill screw 10 is driven in, the face material 80 does not rise when the drill screw 10 is driven, so that the inner diameter of a part of the prepared hole of the face material 80 is increased. In comparison with the above, the portion of the prepared hole having a large inner diameter can be limited to a certain small range, and the decrease in strength against shear stress can be suppressed to a minimum.

Although the embodiment has been described above, the present invention can be modified as follows. The shape of the head that can be engaged with the rotary tightening tool can be designed completely freely, and any type of head shape existing in the related art can be adopted. It is completely free to arrange a counterbore ridge or groove on the outer peripheral surface of the head in the driving direction, and it is possible to implement without providing this. The outer diameter and axial length of the shaft 11 and the drill 13 are also
It can be set as needed as needed. Thread 15a
And the lead angle and the number of strips of 17a can be appropriately determined in accordance with the standard of the drill screw and the like.

The axial length of the first thread forming portion 15 is:
What is necessary is just to form longer than the thickness of the face material etc. which are fastened. In the first thread forming portion 15, the thread 15 a provided therein may not be formed from the lower end of the head 11. That is, the thread 15a may be formed at a position slightly away from the lower end of the head 11. The length of the thread non-formed portion 16 is also set to be equal to or slightly longer than the thickness of the face material to be joined and fixed, and several types are manufactured, and the length according to the thickness of the face material to be joined and fixed is manufactured. Should be used. The outer diameter of the thread-free portion 16 may be smaller than the root diameter of the thread-forming portions 15 and 17. A spiral ridge or groove for excluding may be formed.

In the above embodiment, the axial length of the second thread forming portion 17 is also about 1 pitch to 3 pitches.
This length may also be provided at 3 pitches or more, and can be appropriately determined according to the balance with the lead angle or the like, or the thickness or hardness of the fixed face material, but at least about 1 pitch is provided. Need to be kept. As described above, the pitch of about one pitch means that in the case of a single thread, the helix line of the thread is about one turn. In other words, the helical wire has a length of about one-half of the circumference. In short, regardless of whether it is a single-threaded thread or a multi-threaded thread, its thread is provided at least on the outer periphery of the shaft for at least about one circumference. It just needs to be done.

[0025]

In the drill screw according to the present invention,
There is a non-threaded portion on which no thread is formed in the shaft portion of the screw, and a thread-formed portion having at least one pitch of thread formed under the non-threaded portion is provided. Therefore, for example, when tightening and fixing a surface material made of wooden plywood to a steel channel material, the floating of the surface material from the channel material is minimized, and the screw shaft and the face material There is no gap between them,
Or, even if a gap is provided between the shaft portion and the face material, since that portion can be minimized,
A sufficient fixing strength can be maintained without lowering the fixing strength against shear stress. Also, the driving thrust is not inferior to the conventional one.

[Brief description of the drawings]

FIG. 1 is a front view of a drill screw according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a state in which a face material is fastened and fixed to a channel material by a drill screw according to the embodiment of the present invention, and FIG.
Shows the state that this drill screw has drilled a hole in the face material,
(B) shows an initial state in which a pilot hole is made in the channel material after the pilot hole is made in the face material, and (C) shows that the pilot hole is made in the face material and the channel material, and the face material is formed by the channel material. The state which is fastened to the material is illustrated.

FIG. 3 is an explanatory view showing a state in which a face material and a channel material are fastened and fixed at some places by a drill screw according to the embodiment of the present invention, and then further driving the drill screw. A) shows a state in which a pilot hole has been drilled in the face material and a pilot hole has begun to be drilled in the channel material, and (B) shows a state in which the face material has been completely fastened and fixed to the channel material.

FIG. 4 illustrates a conventional reamed drill screw;
(A) is a front view thereof, (B) shows an intermediate state in which the face material is fastened and fixed to the channel material by the reamer drill screw, and (C) shows the face material and the channel material in an intermediate state. This shows a completely fixed state.

FIG. 5 shows another conventional drill screw, in which (A) is a front view thereof, and (B) is an intermediate state in which a face material is fastened and fixed to a channel material by the drill screw. (C) shows a state in which the face material and the channel material are completely fixed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... drill screw, 11 ... head, 12 ... shaft part, 13 ... drill part, 15 ... 1st thread forming part, 15a ... thread, 1
6: Thread non-forming portion, 17: Second thread forming portion, 17a
… Thread

Claims (2)

[Claims] A head (11) engageable with a rotary tightening tool, a shaft (12) extending downward from the head (11), and a drill formed at a tip of the shaft (12). A drill screw having a tapping and tightening thread formed on the shaft (12), wherein the shaft (12) has a thread (15a) on the head (11) side. ) Is formed on the first thread forming portion (15), and the first thread forming portion (15) is arranged under the non-thread forming portion (16). At least one beneath this unthreaded portion (16)
A second thread forming portion (17) on which a thread (17a) having a pitch is formed. 2. An axial length of the non-thread forming portion (16) is substantially the same as or longer than a thickness of an object to be fastened such as a wooden surface material fastened to a steel structure or the like. The drill screw according to claim 1, wherein: