JP4294802B2 - Drill screw with washer for thin plate fastening - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a washer-provided drill screw used for fastening thin metal plates together.
[0002]
[Prior art]
Flip ne drill, a drill part at one end of the shank, the other end is provided integrally head respectively, it has a configuration forming the external thread between the head and the drill unit.
[0003]
In general, since the male screw is formed by rolling, it is actually impossible to make a complete screw portion up to the seating surface, and it is difficult to avoid the incomplete screw portion remaining in the lower neck portion. For this reason, in JIS, in the case of a tapping screw, it is defined that the incomplete thread portion remains within a maximum pitch range.
[0004]
[Problems to be solved by the invention]
Incidentally, the fastening of the plate to each other by Flip ne drill is carried out by screwing the male screw from leaving a pilot hole drilled portion so the sheet material superimposed external thread of screwed into the front side of the plate material contribution to the fastening However, fastening is performed by screwing a male screw into the plate material on the back side.
[0005]
Therefore, in order to increase the fastening strength, it is necessary to bite the male screw over the widest possible range with respect to the back side plate material without destroying the back side plate material. For this purpose, it is considered that may be used to thread pitch corresponding to the thickness of the plate, when the Flip ne ordinary drill to be used, such as architectural, ease and strength of handling, ease of rolling There is a limit to reducing the outer diameter from the standpoint of properties and the like, and generally, an outer diameter larger than about 4 mm is used.
[0006]
For this reason, for example, when fastening steel plates having a thickness of 1 mm or less, the pitch of the male screw is many times the thickness of the plate material, and therefore, the incomplete screw below the neck of the male screw is placed on the back plate material. As a result, the female screw of the plate material is crushed so that it cannot be fastened, and even if it can be fastened, sufficient strength cannot be obtained, or it becomes easy to loosen.
[0007]
Because of these problems, when it is necessary to fasten the thin plates firmly, drill holes in the two thin plates in advance, and rivets are fastened, but this increases the number of man-hours. There is a drawback that work efficiency is remarkably bad.
[0008]
The present invention, even Flip ne drill incomplete thread portion on the neck lower portion are formed, and an object thereof is to allow firm fastening the thin plates.
[0009]
[Means for Solving the Problems]
The present invention has achieved the above object by incorporating a special washer into a drill screw .
[0010]
The present invention comprises a drill screw in which a drill portion is integrally formed at one end of the shank and a head is integrally formed at the other end of the shank, and a single washer that fits into the shank of the drill screw. The drill screw shank is formed with a male screw, and the male screw of the drill screw is an incomplete screw portion in a lower neck portion.
Before SL washer is set to a thickness dimension that covers a part of the whole and the complete thread portion of the incomplete thread portion of the drill screw, closer to the head of the drill screw of the inner peripheral surface of the washer An inward ridge that engages with the male screw of the drill screw is formed in the portion, and a portion of the inner peripheral surface of the washer excluding the ridge is formed by drilling a pilot hole in the stacked thin plate with a drill portion. When the thin plates are fastened together, at least the inner peripheral edge of the front side thin plate that is in close contact with the washer is a burring allowable portion that can enter into a state of protruding toward the inside. It has penetrated to the complete thread.
[0011]
Then, the previous SL incomplete thread portion of the seat and the shank of the head in the drill screw, while being continuously via the tapered surface of the tapered-off toward the incomplete thread portion, inward of the washer The protrusion has a trapezoidal cross section having an inclined surface that is in close contact with or in close contact with the tapered surface of the drill screw.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0013]
1 is a separated view of the drill screw 1 and the washer 2. FIG. 2 is a plan view of the washer 2. FIG. 3 is a view of the washer 2 attached to the drill screw 1. FIGS. FIG. In FIG. 3, the cross-sectional display (hatching) of the washer 2 is omitted.
[0014]
The drill screw 1 is the same as the conventional one. The shank 3, the drill part 4 provided at one end of the shank 3, the head 6 with a cross hole 5 provided at the other end of the shank 3, the drill part 4, A male screw 7 formed between the head 6 and the head 6 is provided. The range of a certain dimension L1 from the seating surface 8 of the male screw 7 is an incomplete threaded portion 9, and the connecting portion with the seating surface 8 is tapered toward the incomplete threaded portion 9. It is (. showing a tapered surface at 10).
[0015]
The washer 2 is formed in a hexagonal shape in plan view using a metal plate having spring properties such as spring steel, stainless spring material, steel plate, etc. (other planar shapes such as a circle may be used), and its thickness dimension T is The dimension is set to about twice the axial dimension L1 of the incomplete thread portion 9 in the drill screw 1. In other words, the washer 2 is set to a thickness dimension that covers all of the incomplete screw portion 9 and a part of the complete screw portion. The thickness dimension T of the washer 2 is set to be larger than the pitch of the male screw 7.
[0016]
An inward protruding ridge 11 having a trapezoidal cross section that engages with the male screw 7 of the drill screw 1 is formed at a portion of the washer 2 close to the head 6 of the drill screw 1. The upper surface of the inwardly extending ridge 11 is set so as to be in close contact with or in close contact with the tapered surface 10 of the drill screw 1, and in this way, there is an advantage that the washer 2 can be positioned concentrically with the drill screw 1.
[0017]
And the thin plates 12 and 13 to be fastened are set by setting the inner diameter D1 of the portion below the inward protrusion 11 in the inner periphery of the washer 2 to an inner diameter of about 1.1 times the outer diameter D2 of the male screw 7. Among them, the inner peripheral edge of the thin plate 12 on the front side which is in close contact with the washer 2 is formed with a burring allowable portion 14 which can enter. The burring permissible portion 14 is set to a depth dimension L2 that extends to the incomplete thread portion 9 of the drill screw 1.
[0018]
When the thickness of the thin plates 12 and 13 is 1 mm or less, the dimension of the washer 2 is specifically the thickness dimension T when the outer diameter (nominal diameter) D2 is used for the drill screw 1 having a thickness of 5 mm. What is necessary is just to set about 2.3 mm, the internal diameter of the inward protrusion 11 about 4.3 mm, and the internal diameter D1 of the burring allowable part 14 to about 5.5 mm.
[0019]
In the above-described configuration, the washer 2 is attached to the drill screw 1 in advance by screwing the washer 2 into the drill screw 1 or by pushing it against the elasticity of the inward protrusion 11. Then, as shown in FIG. 4, normal work and in the same manner, by pressing the thin plate 12 while rotating the drill screw 1 using a power tool, it performs fastening work of the thin plates 12, 13.
[0020]
Then, from the spaced bottom hole in the thin plate 12, 13 by the drilling unit 4, the male screw 7 will bite into the inner peripheral edge of the sheet 12. In this screwing process, since both the thin plates 12 and 13 are pushed downward, both thin plates 12 and 13 tend to be formed with burring portions protruding downward.
[0021]
Then, when the drill screw 1 is further screwed in a state in which the washer 2 is in close contact with the front thin plate 12 and the head 6 is in close contact with the washer 2, the inner peripheral edges of both thin plates 12 and 13 are the washers as shown in FIG. It is pulled in by the burring permission part 14 of 2 and becomes selfish. In other words, the thin plates 12 and 13 are formed with cylindrical burring portions 12 a and 13 a that protrude toward the inside of the washer 2.
[0022]
In the state of FIG. 5, the entire burring portion 12 a of the thin plate 12 on the front side is drawn into the washer 2, and the burring portion 13 a of the thin plate 13 on the back side is partially drawn toward the inside of the washer 2.
[0023]
The state of the burring portions 12a and 13a of both the thin plates 12 and 13 depends on the thickness dimensions of the thin plates 12 and 13, the thickness of the washer 2, the inner diameter of the burring allowable portion 14 in the washer 2, and the male screw 7 Depending on various conditions such as the pitch, the burring portions 12a and 13a of the two thin plates 12 and 13 may completely enter the washer 2 in some cases.
[0024]
In any case, as can be easily understood from FIG. 5, the burring portion 13 a of the thin plate 13 on the back side is pulled into the washer 2, so that the male screw 7 of the drill screw 1 is placed on the back side over a wide range. The thin plate 13 can be bitten, and the complete screw portion of the male screw 7 bites into the burring portion 13a, so that the destruction and crushing of the female screw formed on the burring portion 13a can be prevented or significantly suppressed. .
[0025]
Further, when the washer 2 is not present, the burring portion 12a of the thin plate 12 on the front side is clogged in the lower neck portion of the drill screw 1, so that the burring portion 13a of the thin plate 13 on the back side spreads easily and is easily broken. However, according to the present invention, since the burring portion 12a of the thin plate 12 on the front side has entered the burring allowable portion 14 of the washer 2, it is possible to prevent the burring portion 13a of the thin plate 13 on the back side from being broken.
[0026]
And the high fastening strength can be obtained by the synergistic effect of these actions.
[0027]
If the washer 2 is made of a metal plate having a spring property, it is more preferable because it can exert its locking effect by utilizing its elasticity. In this case, as shown in the figure, if the outer diameter of the washer 2 is set to about 1.5 to 2 times the diameter of the head 6 of the drill screw 1, the springiness of the washer 2 is more effective. It can be used for this.
[0028]
Although not shown, if the washer 2 is made of an elastic material and has a dish washer with a recessed lower surface, the loosening prevention effect can be further improved.
[0029]
[0030]
The implementation embodiments described above to form the inner periphery of the burring allowing portion 14 straightly, but may be formed in a tapered shape expanding in diameter toward the outside. The washer can also be manufactured from a material other than metal, such as a synthetic resin. Needless to say, there are no restrictions on the shape of the perforated portion or head of a drill screw or tapping screw using a washer, the pitch of a male screw, or the like.
[0031]
The washer of the present invention can also be applied to the case where three or more thin plates are fastened. In that case, the inner diameter of the washer may be increased.
[0032]
[Operation and effect of the invention]
According to the present invention, in fastening the thin thin plates by drilling screws or tapping screws, with the screwing of the screw, the inner peripheral edge of at least the front side of the thin plate by being pulled into the direction of the washer, of the back side of the thin plate A burring portion that protrudes toward the inside of the washer can be formed on the periphery, and a complete thread portion of a male screw can be screwed into the burring portion.
[0033]
And, the burring part of the thin plate on the back side protrudes toward the washer, and the complete screw part of the male screw bites into the burring part, so that the female screw formed on the thin plate on the back side is It collapsed resulting phenomenon can be prevented or significantly suppressed (so-called screw phenomenon becomes fool), as a result, can be fastened in even thinner thin plates strong intensity.
[0034]
Further, in performing the fastening operation by the drill screw using a power driver, since the conventional easily crushed sheet female thread, (determination of whether to stop the rotation that is, any point) adjustment of the torque narrowing Ji roots but is difficult If the washer of the present invention is used, the internal thread will not be crushed even if it is screwed with a strong torque, so the occurrence rate of fastening failure can be significantly reduced.
[0035]
In addition, washer because it has an inward protrusion, because it becomes easy to advance attach the washer to the Flip I drill, can be performed with good efficiency of the fastening work.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a washer according to the present invention separated from a drill screw.
FIG. 2 is a plan view of a washer.
FIG. 3 is a cross-sectional view of the washer attached to a drill screw.
FIG. 4 is a diagram showing a fastening process.
FIG. 5 is a cross-sectional view in a state where fastening is completed.
[Explanation of symbols]
1 drill screw 2 washer 4 drill unit 6 head 7 male thread 9 incomplete thread portion 11 inward projections 12, 13 sheet
12a, 13a Burring part 14 Burring allowance part

Claims (1)

The drill part is integrally formed at one end of the shank and the head is integrally formed at the other end of the shank, and a single washer that fits into the shank of the drill screw, The shank of the drill screw is formed with a male screw, and the male screw of the drill screw is an incomplete screw portion in a lower neck portion,
The washer is set to a thickness dimension that covers all of the incomplete thread part and a part of the complete thread part in the drill screw, and a part of the inner peripheral surface of the washer that is close to the head of the drill screw Are formed with inwardly extending ridges that engage with the male screw of the drill screw, and parts of the inner peripheral surface of the washer except for the ridges are prepared by drilling pilot holes in the stacked thin plates at the drill portion. When fastening the thin plates, at least the inner peripheral edge of the front side thin plate that is in close contact with the washer is a burring allowable portion that can enter into a state protruding toward the inside , and the burring allowable portion of the washer is an incomplete drill screw. It goes into the screw part ,
Further, the head seat surface of the drill screw and the incomplete thread portion of the shank are continuous through the tapered surface tapered toward the incomplete thread portion, while the inward projection of the washer. The strip has a trapezoidal cross section having an inclined surface that is in close contact with or in close contact with the tapered surface of the drill screw.
Drill screw with washer for thin plate fastening.

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