JPS5911205Y2 - Drive screw - Google Patents

Description

[Detailed description of the invention] The present invention relates to a driving screw that can be screwed into a hard and elastic material such as a steel plate without having to drill a pilot hole for the screw in the previous process. It is.

Conventionally, tapping screws and self-drilling screws are known as screws that can be screwed into a steel plate or the like without having to drill pilot holes for the screw in a previous process.

However, tapping screws have a small thread rolling capacity and are limited to fixing and tightening thin steel sheets together.

In addition, self-drilling screws have a large thread cutting capacity, so they can be screwed into thick steel plates.

However, there are disadvantages in that it takes a long time to drill a hole to penetrate the pilot hole, and a large thrust force must be continuously applied throughout the drilling process.

As an example, this thrust can reach as much as 30 kg. Moreover, it has the disadvantage that the torque for thread cutting is extremely large.

Furthermore, there is a drawback that the processing cost for forming a drill bit at the tip of the self-drilling screw is high.

Furthermore, self-drilling screws have a threaded portion that is only as thick as the thickness of the thick steel plate, and because the holding force after screwing is small, the screws tend to loosen due to vibrations.

Further, as another example, a screw shown in FIG. 1 is known.

This screw 100 has a bullet-shaped tip 101 from the tip side,
The shank part 102, the screw part 103, and the screw head 104 are formed in this order, and the maximum diameter a' of the tip part 101 is the diameter of the screw pilot hole 106 of the screwed material 105 (the middle of the screw thread diameter and the screw root diameter). It is shaped to be approximately equal to the diameter of the diameter.

When the screw 100 having such a structure is screwed into the material 105 to be screwed with the driver 107 which is a screwing tool, the diameter b' of the screw thread formed in the screw pilot hole 106 becomes the diameter b' as described above due to plastic deformation. The diameter is smaller than the maximum diameter a' of the tip 101.

In this way, when the relationship between the maximum diameter a' of the tip 101 and the diameter b' of the thread is a'>b', the screw 1
00, the actual situation is that the tip 101 gets caught on the thread, making it difficult to remove.

Therefore, the present invention was proposed in order to solve the above-mentioned conventional drawbacks, and it is possible to screw into the material to be screwed without having to drill a pilot hole in the material to be screwed in the previous process, and to screw the screw into the material. First, the objective is to provide a driving screw that can be vertically held against the material to be screwed.

Another object of the present invention is to provide a driving screw that has good bite and requires less screwing force when screwed into a material to be screwed.

Furthermore, it is an object of the present invention to provide a driving screw that can be removed from the material to be screwed after screwing.

The gist of the present invention is to provide a punch portion for forming a burring hole in a material to be screwed, and a hole formed by the punch portion to have a smaller diameter than the maximum diameter of the punch portion. A columnar part that fits coaxially into a burring hole formed, a threaded part that continues to the columnar part, and a screw head that continues to the threaded part, the threaded part that continues to the columnar part. The diameter of the first threaded part of the threaded part is the same as or smaller than the diameter of the columnar part, and the threaded part of the threaded part is larger than the maximum diameter of the punch part from the first threaded part. It is characterized in that the diameter gradually expands toward the regular screw root which has a large diameter.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

FIG. 2A is an enlarged side view of the driving screw, and FIG. 2B is an enlarged plan view of the driving screw.

This driving screw 1 has a punch part 2 whose entire shape is almost a cannonball shape on the tip side, a cylindrical part 3 which is a column part following this punch part 2, and a first screw root part which will be described later following this cylindrical part 3. 12
It consists of a tapered threaded portion 4 whose diameter gradually increases from the middle toward a threaded trough (regular threaded trough) 13, and a screw head 5 continuing from the tapered threaded portion 4.

The leading edge 2a of the punch portion 2 is shaped like a hemisphere, and as shown in FIG. When the thick steel plates 8 are stacked in the order of construction material 9, the tip 10a of the burring hole 10 formed in the thick steel plate 8 located at the lowest end is made to have a somewhat uniform height. It has the effect of aligning the holes and also has the effect of being easy to drive into the steel plate 8.

The cylindrical part 3 following the punch part 2 holds the entire driving screw 1 coaxially with the burring hole 10 when the driving screw 1 is driven into the thick steel plate 8, as shown in FIG. The length of the cylindrical portion 3 is larger than the sum of the thickness of the thick steel plate 8 and the distance from the tip 10a to the base 10b of the burring hole 10. 2 penetrates through the thick steel plate 8, only the cylindrical portion 3 contacts the hole wall of the burnong hole 10.

Furthermore, by shaping the cylindrical portion 3, the torque at the time of driving can be reduced.

Note that the diameter b of the cylindrical portion 3 is set to be smaller than the maximum diameter a of the punch portion 2.

In the tapered threaded portion 4 following the cylindrical portion 3, the thread diameter C of the first threaded portion 11 is the diameter b of the cylindrical portion 3.
The top of the mountain portion 11 starts flush with the side surface of the columnar portion 3.

Note that the root diameter d' of the first screw root portion 12 is the same as that of the punch portion 2.
The diameter is set to be smaller than the maximum diameter a.

Initial threaded portion 11 and threaded root portion 1 of tapered threaded portion 4
2 as described above, after driving the driving screw 1, when screwing into the thick steel plate 8 with a screwdriver 60, which will be described later, as shown in FIG. 10 has good bite and requires less screwing force.

Incidentally, the root diameter of the regular screw root portion 13 of the tapered threaded portion 4 (the portion that has finished biting into the burring hole 10 of the thick steel plate 8 when screwing is completed as shown in FIG.
The diameter is set to be larger than the maximum diameter a of.

The screw head 5 following the tapered screw portion 4 has a driving screw 1.
A Phillips groove 14 is formed for screwing and driving by a screwdriver 60 which is a screwing tool.

In addition, here, the maximum diameter a of the punch portion 2 of the driving screw 1 is
, the diameter b of the cylindrical part 3, the crest diameter C of the first threaded part 11 of the tapered threaded part 4, and the root diameter d' of the first threaded trough 12.
and the root diameter d of the screw root portion 13 in the middle of the tapered screw portion 4.
If we organize the relationship, we get the following formula.

d>a>b=c>d' Next, using the driving screw 1 having the above structure, the thin steel plate 6 is
, a plaster board 7, and a thick steel plate 8, which are stacked in this order, and a construction material 9 will be described with reference to FIGS. 3 to 5.

First, as shown in FIG. 3, the driver 51 of the driving tool 50 is
When the screw head 5 of the drive screw 1 is struck by the screw, the punch portion 2 of the drive screw 1 breaks through the thin steel plate 6, and further pierces the thick steel plate 8 while forming a hole 15 in the plasterboard 7. A burring hole 10 is formed in this thick steel plate 8.

Then, when the punch portion 2 penetrates the thick steel plate 8,
The buckling effect of the thick steel plate 8 acts on the burring hole 10, and the hole diameter becomes slightly smaller than the through hole diameter.

As a result, the circumferential side surface of the cylindrical portion 3 is slightly tightened and pressed into contact with the hole wall of the burring hole 10.

As a result, the entire driven screw 1 is held coaxially centered with respect to the burring hole 10.

Normally, with any threaded member, if the threaded member is not held perpendicular to the material to be screwed, the screwing torque will increase abnormally, and the screw threads will be damaged. Although the holding force will be significantly reduced, according to the driving screw 1, the entire screw can be completely held vertically by the action of the cylindrical portion 3, so that the holding force after screwing in increases.

Further, at this time, the cylindrical portion 3 of the driving screw 1 is located within the burring hole 10, and the tapered threaded portion 4 of the driving screw 1 has not yet reached the burring hole 10.

Therefore, the driving resistance is small, and the recoil of the driving tool 50 experienced by the operator is also small.

Moreover, the driving energy of the driving tool 50 can be reduced.

Next, the screw 1 driven in as described above is driven in with a screwdriver 60 as shown in FIG.

At this time, the diameter C of the first crest 11 of the tapered threaded part 4 of the driving screw 1 is the same as the diameter b of the cylindrical part 3, and the diameter d' of the first trough 12 is the same as that of the punch part. Since the diameter is smaller than the maximum diameter a of No. 2, the tapered threaded portion 4 bites into the burring hole 10 well, and the screwing torque at the start of screwing can be small.

When the driving screw 1 is further screwed in, the driving screw 1 can attain the screwed-in state shown in FIG. 5.

At this time, since the above-mentioned driving screw 1 has a tapered threaded part 4, the screwing torque is smaller than that of a screw with a normal straight threaded part, and it is possible to screw it in securely to the end. It is.

In addition, since a complete thread is formed in the burring hole 10, the holding force of the driving screw 1 against the thick steel plate 8 is lower than that of a self-drilling screw or a self-drilling screw, in which the thread is formed only by the thickness of the steel plate. The mutual adhesion force between the thick steel plate 8, the gypsum board 7, and the thin steel plate 6 is much larger than that.

Next, the screw 1 screwed in as described above is inserted into the thick steel plate 8.
We will explain how to remove it from.

Since the root diameter d of the thread trough 13 in the middle of the tapered threaded portion 4 of the driving screw 1 is set to be larger than the maximum diameter a of the punch portion 2, the burring hole 10 is formed. The diameter of the thread on the upper end side in the figure is larger than the maximum diameter a of the punch portion 2.

Therefore, when removing the driving screw 1, the punch portion 2 is not caught by the thread, and can be removed smoothly.

As described above, according to the above embodiment, it is possible to screw in the thick steel plate 8 without drilling a pre-screw hole in the pre-process, thereby reducing costs.
It has good bite, and the screw-in torque is small.

Further, each member of the building material 9 constructed by stacking the thick steel plate 8, the plasterboard 7, and the thin steel plate 6 in this order is securely fixed.

Furthermore, it can be easily removed from the thick steel plate 8, and is highly effective in fields where attachment and removal operations are frequently performed, for example, in the work of attaching exterior walls to factories.

As described above, according to the present invention, screwing can be performed without drilling pilot holes in the material to be screwed in the previous step, so that the time required for screwing can be shortened.

Therefore, cost reduction is encouraged. Furthermore, since the perpendicularity of the entire screw to the material to be screwed is maintained at the start of screwing, it is possible to screw the screw straight into the material to be screwed.

Furthermore, when screwing into the material to be screwed, the screw has good bite and requires less screwing force.

Therefore, worker fatigue is reduced.

Furthermore, since it can be easily removed from the material to be screwed, it is highly effective for use in places where mounting and dismounting operations are frequently performed.

[Brief explanation of the drawing]

Figure 1 is a side view of a screw showing a conventional example, Figures 2 to 5
The figures show a preferred embodiment of the present invention, in which Fig. 2A is an enlarged side view of the driving screw, Fig. 2B is an enlarged plan view of the driving screw, and Fig. 3 is an enlarged plan view of the driving screw. Fig. 4 is a longitudinal sectional view showing the driving screw being driven into a thick steel plate, Fig. 5 is a longitudinal sectional view showing the driving screw being driven into the thick steel plate, and Fig. 5 is a longitudinal sectional view showing the driving screw being driven into the thick steel plate. FIG. 1... Drive screw, 2... Punch part, 3
...Cylindrical part, 4...Tapered threaded part,
5...Screw head, 8...Thick steel plate, 10
...Burring hole, 11...First threaded part, 12...First threaded valley part, 13...
...Regular screw valley.

Claims (1)

[Scope of utility model registration request] A punch part for forming a burring hole in the material to be screwed, and a punch part that is contiguous to this punch part and is shaped to have a smaller diameter than the maximum diameter of the punch part and is coaxial with the burring hole formed by the punch part. A column body part that fits into the column body part, a threaded part continuous to this column body part, and a screw head further continued to this threaded part,
The diameter of the first threaded part of the threaded part following the columnar part is the same as or smaller than the diameter of the columnar part, and the threaded part of the threaded part is formed from the first threaded part. A driving screw characterized in that the diameter of the screw gradually increases toward a regular screw root portion formed to have a diameter larger than the maximum diameter of the punch portion.