JP2843932B2 - Non-slip processing tool for steel sheet superposed surfaces - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for increasing the friction coefficient of a mating surface so that the mating surface does not slip when steel plates are overlapped and joined by bolting, and a processing tool therefor.

[0002]

BACKGROUND OF THE INVENTION In the construction of buildings, bridge girders and other steel structures, large steel materials are often joined by directly overlapping their flat surfaces or by stacking eye panels and joining them with bolts or rivets.
At that time, first temporarily tighten with one or two bolts, then temporarily tighten the other end of the steel material or an important part of the structure, and confirm that the columns and beams are assembled without bending etc. After that many remaining bolts or rivets will be installed. When the seam is temporarily tightened with a small number of bolts as described above, the load due to its own weight is applied to the seam, so the steel material may slip only in the gap between the bolt and the bolt hole, sometimes it does not stop only at the gap The edge of the bolt or steel hole may be deformed and shifted. In such a case, since both the pillar and the beam bend, it is necessary to lift the steel material again and perform the temporary fastening again, and the construction is significantly stagnated, which greatly affects the construction cost. This is because the frictional force of the steel material contact surface due to the temporary tightening is smaller than the load applied to the portion, and therefore the bolt tightening force must increase one of the friction coefficients with each surface. However, since the tightening force of the bolt is limited, it is desired to increase the friction coefficient. In addition, since the surface of a new steel material is too smooth , a cumbersome process involving loading and unloading is required, that is , unloading and storage until it is appropriately rusted. The above-mentioned sliding phenomenon is not limited to the temporary tightening bolts, and the same tendency is observed for the main tightening bolts, though the slip is small.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to increase the coefficient of friction around the bolt hole on the contact surface of the overlap so that the bolt hole of the steel sheet overlap seam does not slip as described above.

[0004]

SUMMARY OF THE INVENTION The present invention increases the coefficient of friction by engraving a knurl pattern concentrically around the bolt hole of the steel sheet overlap seam so that the bolt does not slip after tightening. How to The knurl pattern around the bolt hole is a pattern that matches a radial line from the center of the bolt hole, or a pattern that keeps a constant angle with respect to radiation, and a pattern in which a line that keeps an opposite constant angle with respect to radiation overlaps with this.

In order to continuously perform drilling and knurling of a knurl pattern, the working tool of the present invention has a handle portion above a drill blade portion having a hole size of a steel plate to be drilled, and a center portion of a metal block. Insert the hole up and down from below into the upper part of the blade part and fix it with bolts screwed in from the side of the metal block. This is a processing tool that is attached with pins so that the drills come out, and the upper end of the drill handle is gripped with a drill press chuck and rotated. Since the distance between the two knurl pieces depends on the thickness of the bolt, it is necessary to provide several types of the above-mentioned block tools. The outer peripheral surface of the knurl may be a cylinder, but the operation is smoother if a part of the conical surface having the apex at the center of the bolt hole is used. Furthermore, when only knurling is performed, the drill may be removed from the tool and a rod having the same shape may be used.

[0006]

Since the object of the present invention is to increase the friction coefficient of the contact surface of the steel plate overlapping portion of the bolt tightening portion, it is only necessary to form irregularities only around the bolt. The size of the irregularities does not matter even if it is fine. If the knurled pattern is engraved on only one side and tightened, the ridges of the pattern will bite into the mating steel plate, so it is not necessary to engrave the knurled pattern on both sides. If this is done, the knurling operation can be shifted to the knurling operation with the same pressing force at the same time as the drill penetrates the steel plate, so that the knurling operation can be performed with almost the same time as the operation of only drilling.

[0007]

FIG. 1 shows examples of various knurl patterns, and FIG.
FIG. 3 is a cross-sectional view of a working tool incorporating a drill. 1 is a rectangular metal block drilled in a hole passing through the center vertically
The tip of the bolt 5 in the tap hole 4 provided horizontally from the side surface of the metal block 1 toward the handle 3 enters the barb 6 or hole provided in the handle 3. Thereby, the handle 3 is fixed to the metal block 1. The diameter of the drill blade 7 is larger than that of the handle 3, and the upper end surface thereof is in close contact with the lower surface of the metal block 1. A horizontal pin 9 is provided on the lower surface of the metal block 1 so that a knurled piece 8 is sandwiched between the drill blade 7 and the outer peripheral portion of the metal block 1 from the lower surface.
Is incorporated by In such a structure, the handle 3
If the upper end of the drill is gripped and rotated by a chuck such as a drilling machine, an electromagnetic fixed type mag ball, or a portable electric drill, it operates as a drill at first. Is pressed against the surface of the steel plate and rotated, so that a knurl pattern is immediately formed around the hole, increasing the friction coefficient of the steel plate surface around the hole. Therefore, when the bolt is tightened, the steel plate does not slip at that portion.

[0008]

According to the knurl pattern engraving method of the present invention, the coefficient of friction around the holt hole of the steel sheet can be easily increased, and slip on the steel sheet contact surface can be almost completely prevented. Further, according to the working tool of the present invention, a knurl pattern can be carved around the bolt hole by adding a little time to the drilling operation of the steel plate, and the friction coefficient of the contact surface of the steel plate is increased, thereby assembling the steel material on site. Since the construction can be performed with few errors, it greatly contributes to the reduction of construction costs. From the viewpoint of the steel material shipping side, there is no need to pile up the surface of the steel material in order to rust the surface of the steel material, which saves costs such as loading into a vehicle and unloading.

[Brief description of the drawings]

FIG. 1 is a plan view of an example of a knurl pattern.

FIG. 2 is a cross-sectional side view of a processing tool that continuously performs drilling and knurling.

[Explanation of symbols]

 1. Metal block 3. Handle part 5. Fixing bolt 6. Sogi part 7. Blade part 8. Knurl pieces

Claims (1)

(57) [Claims] In order to continuously perform drilling and knurling, a handle portion above a drill blade having a size of a hole to be drilled is formed into a hole vertically penetrating the center of a metal block.
Fixed in the plug metal block out the lower part of the blade portion, the both sides of the drill bit on the lower surface of the metal block, so as to rotate out of the outer peripheral portion of the knurling piece from the lower surface of the block
Steel plate superimposed surface of the anti-slip machining tool attached to the