JP2010089207A - Screwing assist tool for tapping screw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screwing assist tool for a tapping screw, and more in detail, an assist tool which supports the tapping screw orthogonal to a member to be fastened when screwing the tapping screw. <P>SOLUTION: The screwing assist tool for the tapping screw comprises a conical cylinder guide and a base. The conical cylinder guide is tapered from its upper end to form a conical cylinder to its lower end. An inner wall of the conical cylinder guides a screw head side surface in a sliding manner, and forms a first perforation on a side surface of the conical cylinder. In the base, the conical cylinder guide is erected at the substantially center of a surface abutting on a member to be fastened, and an easily breakable second perforation is formed in the surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fastening aid for a tapping screw, and more particularly to an auxiliary tool that supports the tapping screw perpendicularly to a fastening material when the tapping screw is tightened.

  The tapping screw is a screw that is provided with a cutting blade structure at a tip portion of the tapping screw and is fastened while cutting a tap on a fastening material by the cutting blade. Fastening with a tapping screw eliminates the need for tapping the fastening material, thereby reducing costs and is widely used for various fastenings in electrical equipment and the like.

  When fastening the tapping screw, a pilot hole that is slightly larger than the tip of the tapping screw is made in advance in the fastening material, and the tip of the tapping screw is inserted into the prepared hole through the hole formed in the material to be fastened to be perpendicular to the fastening material. Clamping (screwing) is performed while holding the pin so that it is aligned (that is, matching the axis of the tapping screw with the axis of the pilot hole). By this tightening, the cutting blade of the tapping screw is rotated, and a tap is formed on the wall surface of the prepared hole of the fastening material, and the fastening material and the material to be fastened are fastened.

  Details of the fastening by the tapping screw will be described with reference to FIG. FIG. 5 shows an example in which a side plate is fastened to a frame-structured housing using a tapping screw. A pilot hole 21 is formed in advance in the frame to be the fastening material 20. The tip of the tapping screw 10 is tapered, and a cutting blade is formed at that portion. The diameter of the pilot hole 21 is a through hole having a diameter that allows the thread 1 to 1.5 pitch of the tip of the tapping screw 10 to be inserted. A hole 31 is also formed in the side plate that is to be fastened 30. The diameter of the hole 31 is larger than the outer diameter of the thread of the body of the tapping screw 10 and smaller than the outer diameter of the screw head.

  First, the hole 31 of the material to be fastened 30 is overlapped with the pilot hole 21 of the fastening material 20, and the tip portion of the tapping screw 10 is put into the pilot hole 21 of the fastening material 20 through the hole 31 of the material to be fastened 30. The tapping screw 10 is supported by hand so as to be perpendicular to the fastening material 20, and tightened while pressing the driver 40. The tapping screw 10 is rotated by tightening, and the cutting blade cuts the inner wall of the pilot hole 21 of the fastening material 20 to form a tap. When tightening is performed until the tip of the tapping screw 10 protrudes the plate thickness of the fastening material 20, the formation of the tap by the cutting blade is finished, and the tapping screw 10 slides on the tap in which the thread of the body portion is formed. It becomes a movement. When the tightening is further continued, the bottom of the screw head of the tapping screw 10 hits the material 30 to be fastened, and the rotational torque of the driver 40 is increased to complete the tightening.

  The above is a description of a state in which the tapping screw 10 is normally tightened. However, when the tapping screw 10 is tilted without being held vertically, the cutting blade is attached to the fastening material 20. The tap is cut while proceeding diagonally through the pilot hole 21, and the tapping screw 10 may be bitten and may not move, or the fastening material 20 may be damaged in some cases. Further, it may be difficult to remove the tapping screw 10 even if it is intended to be removed.

  As a method to suppress the tilting of the tapping screw, the contact area between the prepared hole and the tapping screw shaft is reduced by making the prepared hole in the fastening material a square hole with a rectangular cross section that inscribes the tapping screw shaft. And the pilot hole structure which suppresses an inclination by reducing the insertion resistance of a tapping screw by this is known (patent document 1).

  In addition, as a pilot hole structure for the same purpose, the inlet portion of the pilot hole has a large diameter at a height of about one pitch of the tapping screw thread, and a spiral inclination equal to the inclination angle of the tapping screw thread on the large diameter bottom surface. A structure for forming a surface is known (Patent Document 2).

In addition, although not a tapping screw, in order to drive the nail perpendicular to the surface of the material, a mortar-shaped depression having a different depth is provided on the upper and lower surfaces of the elastic body, and a through-hole that supports the trunk of the nail is provided at the center of the depression. There is known an nail driving aid that is formed and provided with a notch groove for removing from a nail from a through hole toward a side surface (Patent Document 3).
Japanese Patent No. 3456854 JP 2007-187305 A Japanese Patent No. 3660675

  As described above, when the tapping screw is tightened, the tapping screw can be tightened while supporting the shaft center of the tapping screw and the shaft center of the pilot hole (that is, the tapping screw is perpendicular to the fastening material). is necessary. For this reason, in the past, tightening was performed while supporting the tapping screw vertically with respect to the fastening material by hand, but the support force by hand is weak, and even if it is slightly tilted, it can be said that it shifts to biting and is sufficient. There wasn't.

  The pilot hole structure known in Patent Document 1 and Patent Document 2 can be expected to have an effect of suppressing the tapping screw being tightened while tilting, but the shape of the pilot hole is complicated and it takes time to form the pilot hole. There is a problem in terms of cost.

  Moreover, although the auxiliary tool of patent document 3 is thought to be effective with respect to a nail, if this holder is applied to a tapping screw, the trunk | drum part which has a thread will be supported, and a thread may be damaged. Can be considered.

  An object of this invention is to provide the auxiliary tool which suppresses the biting by the inclination to a fastening material by supporting a tapping screw perpendicularly to a fastening material.

  The tapping screw tightening auxiliary tool of the present invention comprises a conical tube guide part and a base part.

  The conical cylinder guide part is conically shaped from the upper end of the opening to the lower end and forms a conical cylinder. The inner wall of the conical cylinder slides and guides the screw head side surface of the tapping screw, and the lower end is the threaded part of the tapping screw. The first perforation is formed with a diameter that allows it to pass through and is easy to break from the upper end to the lower end on the side surface of the conical cylinder.

  The base portion is provided with the lower end of the conical tube guide portion standing substantially downward in the center of the plane abutting on the fastening material, and the through hole formed in the plane continues to the opening at the lower end, and continues to the first perforation on the plane. Thus, a second perforation that is easy to break is formed toward the periphery of the plane.

  When using the tapping screw tightening assisting tool of the present invention, the tapping screw tightening assisting tool is applied to the material to be fastened placed on the fastening material, and the bottom of the conical tube guide part of the tapping screw tightening assisting tool is applied. The hole to be opened is aligned with the lower hole of the fastening material through the material to be fastened, and after inserting the tapping screw from the upper end of the tapping screw fastening aid, the screw head of the tapping screw is tightened (screwed) with a screwdriver. When the tapping screw advances into the fastening material by tightening, the side surface of the screw head presses the inner wall of the conical tube guide portion outward, and the perforation formed on the side surface of the conical tube guide portion is broken. Further, as the tapping screw advances, the base perforation breaks, and the tapping screw fastening aid is removed from the tapping screw. After removal, tightening is continued until the screw head is in an appropriate position, and the fastening is completed.

  By tightening the tapping screw, the screw head of the tapping screw is guided by the inner wall of the conical tube guide portion and proceeds to the fastening material, so that the tapping screw can be tapped while being kept perpendicular to the fastening material. Become. Further, the tapping screw tightening auxiliary tool can be easily removed from the tapping screw because the perforation breaks during the tapping screw tightening.

(Embodiment 1)
A tapping screw tightening assisting tool 100 of the present invention will be described with reference to FIGS. As shown in FIG. 1, the tapping screw tightening auxiliary tool 100 includes a conical tube guide part 110 and a base part 120. The conical tube guide part 110 has a conical tube shape, and the diameter decreases from the upper part to the lower part. The upper part and the lower part are opened, and an upper opening 111 and a lower opening 112 are formed.

  Two perforations 113 and 114 are formed on the side surface of the conical tube guide portion 110. The perforation 113 and the perforation 114 are in symmetrical positions with respect to the axial center of the conical tube guide part 110. In this embodiment, two perforations are provided, but at least one is required. As will be described later, when the screw head side surface of the tapping screw 10 is rubbed against the inner wall of the conical tube guide part 110 while being tightened, and the outward stress is applied from the axial center of the conical tube guide part 110, the perforation is easily broken. It is required to do.

  The base portion 120 is formed by being integrally molded with the conical tube guide portion 110, and a through hole that cannot be seen in FIG. 1 is formed at the center position thereof. The through hole is continuous with the diameter of the lower opening 112 under the conical tube guide 110. That is, the tapping screw tightening assisting tool 100 opens from the upper part toward the lower part.

  Two perforations 121 and 122 are also formed in the base portion 120 (the perforations 122 are hidden in the conical tube guide portion 110 and are not shown), and the perforations 121 and 122 are formed on the conical tube guide portion 110. The perforations 113 and 114 are continued.

  The tapping screw tightening assisting tool 100 shown in FIG. 1 is an example of an assisting tool for a tapping screw having a nominal diameter of 5 mm and a length of 16 mm, and the height from the bottom surface of the base part 120 to the upper edge of the conical cylinder guide part 110 is 22 mm. The base part 120 is square and one side is 20 mm. The material of the tapping screw tightening auxiliary tool 100 is vinyl chloride resin, the thickness of the conical tube guide part 110 is 0.5 mm, and the thickness of the base part 120 is 1 mm.

  The state when the tapping screw 10 is inserted into the tapping screw tightening assisting tool 100 is shown in FIG. 2A shows a plan view seen from above, and FIG. 2B shows a cross-sectional view seen from the side (note that the tapping screw is a side view). As shown in FIG. 2 (b), the tip of the tapping screw 10 partially passes through the lower opening 112 at the lower part of the conical tube guide part 110 and the hole 31 of the material 30 to be fastened, and is partially in the pilot hole 21 of the fastening material 20. In. As described above, the diameter of the pilot hole 21 is formed such that the pitch 1 to 1.5 of the thread at the tip of the tapping screw 10 enters, and the tapping screw 10 is inserted into the tapping screw tightening aid 100. When this occurs, a part of the tip of the tapping screw 10 enters the upper portion of the prepared hole 21.

  The side surface of the screw head of the tapping screw 10 is placed in contact with or close to the inner wall of the conical tube guide part 110. According to the tightening of the tapping screw 10, the side surface of the screw head is in contact with the inner wall of the conical tube guide portion 110, and is guided by the inner wall so that the tapping screw 10 is tightened vertically downward with respect to the fastening material.

  Further, in FIG. 2A, the perforation 122 of the base portion 120 that is hidden behind the conical tube guide portion 110 in FIG. 1 is formed continuously with the perforation 114 formed in the conical tube guide portion 110. I understand that.

  FIG. 3 is a view for explaining an example of use of the tapping screw tightening aid 100.

  FIG. 3A is a part diagram showing the relationship in which the fastening material 20 before fastening, the material to be fastened 30, the tapping screw fastening aid 100, and the tapping screw 10 are arranged in the vertical direction. A pilot hole 21 in which a tap is formed by the tapping screw 10 is formed in the fastening material 20, and a hole 31 through which the body part of the tapping screw 10 is passed is formed in the fastened material 30. The tapping screw 10 is inserted through the upper opening 111 at the top of the tapping screw tightening assisting tool 100 in a state where the tapping screw tightening assisting tool 100 is placed on the material to be fastened 30 superimposed on the fastening material 20.

  FIG. 3B shows a state in which the tapping screw 10 placed in the tapping screw tightening assisting tool 100 is being tightened by the driver 40 while the tapping screw tightening assisting tool 100 is being held by, for example, the hand (the hand is not shown). Is shown. This state is an initial state in which tightening is started, and the screw head of the tapping screw 10 is guided by the inner wall of the conical tube guide portion 110 and is tightened vertically downward. The tapping screw tightening assisting tool 100 of the present invention is characterized in that the side surface of the screw head of the tapping screw 10 is guided by the inner wall of the conical tube guide portion 110, and the tapping screw 10 is tightened vertically while suppressing the inclination of the tapping screw 10. is there.

  Further, the side surface of the screw head of the tapping screw 10 gives a stress that causes the inner wall to face outward from the axial center by tightening, but the stress is small in the state of FIG. 3B, and the perforation 113 formed in the conical tube guide part 110. , 114 is not broken.

  FIG. 3 (c) shows that the perforation 113 of the conical tube guide portion 110 breaks without being able to withstand the stress from the side surface of the screw head of the tapping screw 10 in the state where the tightening has advanced from FIG. 3 (b). Further, a state in which the perforation 121 on the base surface is broken is shown.

  FIG. 3D shows a state in which the tapping screw tightening assisting tool 100 is removed from the tapping screw 10 due to breakage of the perforation 113 and the perforation 121, and the tapping screw 10 is further tightened. When the tightening is completed, the tip of the tapping screw 10 protrudes from below the lower hole 21 because the fastening material 20 is a frame plate, the tap cut on the inner wall of the fastening material 20 and the thread of the body portion of the tapping screw 10. The fastening material 20 and the fastened material 30 are fastened.

FIG. 3D shows the tapping screw tightening assisting tool 100 in which the perforation 113 and the perforation 121 are broken and removed, but the other perforation 114 and the perforation 122 are broken or both. Perforations may break. The point that the tapping screw tightening auxiliary tool 100 can be removed by breaking the perforation is also a feature of the present invention.
(Embodiment 2)
In the first embodiment, the tapping screw tightening assisting tool 100 is removed from the tapping screw 10 by breaking the perforation, which is a disposable assisting tool. Embodiment 2 proposes a tapping screw tightening aid 200 that can be used repeatedly.

  FIG. 4 shows the external appearance of a tapping screw tightening assisting tool 200 according to the second embodiment. The tapping screw tightening assisting tool 200 is composed of two parts divided at a position corresponding to the perforation of the tapping screw tightening assisting tool 100 shown in FIG. That is, a part composed of the conical cylinder guide part 210 and the base part 220 (right side of FIG. 4A) and a part composed of the conical cylinder guide part 211 and the base part 221 (left side of FIG. 4A). Magnets 230 and 231 are attached to the bottom surfaces of the base portions 220 and 221, respectively.

  As shown in FIG. 4 (a), in the state before tightening, the two parts are integrated by the mutual attractive force of the magnets 230 and 231. In this state, the tapping screw 10 is inserted from above and tightened. As the tapping screw 10 is tightened, the side surface of the screw head of the tapping screw 10 is guided by the inner walls of the conical tube guide portions 210 and 211 and is tightened perpendicularly to the fastening material. As tightening progresses, the stress acting on the inner wall of the conical cylinder guide portions 210 and 211 on the side surface of the head of the tapping screw 10 (stress going outward from the inner wall) becomes stronger, and this stress becomes the mutual adsorption force of the magnets 230 and 231. Overcoming and breaking into two. In the state where the tapping screw tightening assisting tool 200 is broken, the tapping screw tightening assisting tool 200 is removed from the tightening position, and the tapping screw 10 is further tightened. FIG. 4B shows the divided tapping screw tightening assisting tool 200.

  The material of the conical tube guide portions 210 and 211 and the base portions 220 and 221 of the tapping screw tightening assisting tool 200 is, for example, austenitic SUS (non-magnetic material) and the thickness is 0.3 mm, and the magnet is, for example, a ferrite magnet. 1.5 mm. The overall external dimensions of the tapping screw tightening assisting tool 200 are substantially the same as those of the tapping screw tightening assisting tool 100.

1 is a structural example (Embodiment 1) of a tapping screw tightening aid of the present invention. FIG. 2 is a tapping screw tightening auxiliary tool (embodiment 1) with a tapping screw inserted therein. FIG. It is an example of use of a tapping screw tightening aid. It is a structural example (embodiment 2) of the tapping screw tightening aid of the present invention. This is an example of tightening a conventional tapping screw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tapping screw 20 Fastening material 21 Pilot hole 30 Non-fastening material 31 Hole 40 Driver 100 Tapping screw tightening auxiliary tool 110 Conical cylinder guide part 111 Upper opening part 112 Lower opening part 113 Perforation 114 Perforation 120 Base part 121 Perforation 122 Perforation 200 Tapping Screw Tightening Aid 210 Conical Tube Guide Portion 211 Conical Tube Guide Portion 220 Base Portion 221 Base Portion 230 Magnet 231 Magnet

Claims (5)

A conical cylinder is formed from the upper end of the opening to a conical shape to the lower end. A conical cylinder guide portion that is open and has a first perforation formed on the side surface of the conical cylinder from the upper end to the lower end.
A conical tube guide portion is erected in the center of a plane that contacts the fastening material, with the lower end down, and a through hole formed in the plane is continuous with the opening of the lower end, and is continuous with the first perforation in the plane. And a base part formed with a second perforation that is easily broken toward the periphery of the flat surface. The tapping screw tightening assist tool according to claim 1, wherein the tapping screw tightening assist tool is integrally formed of resin. The taping screw tightening assist tool according to claim 1 or 2, wherein a plurality of the first and second perforations are formed. A semiconical cylinder is formed by concentrating the conical cylinder from the upper end to the conical shape to the lower end in the axial direction, and the inner wall of the semiconical cylinder slides and guides the screw head side surface of the tapping screw. The lower end is a semi-conical cylinder guide part having a semicircular shape with a radius of a diameter allowing the thread part of the tapping screw to pass through;
At the center of one straight edge of the flat surface abutting the fastening material, the dividing surface of the half-conical tube guide part is erected in accordance with the straight edge with the lower end down, and formed on the straight edge. A tapping screw tightening assisting device comprising: a concave portion connected to a semicircular edge portion of the lower end; and a base portion on which a magnetized magnetic material is attached to a surface that abuts on the flat fastening material. A tapping screw tightening assisting tool comprising two tapping screw tightening assisting members,
The tapping screw tightening auxiliary member has a semi-conical cylinder in which a conical cylinder having a conical diameter from the opening upper end to the lower end is divided into two equal parts in the axial direction, and the inner wall of the semi-conical cylinder is a screw head side surface of the tapping screw The lower end is a semi-conical cylinder guide part having a semicircular shape with a radius that allows the threaded part of the tapping screw to pass therethrough, and the center of one straight edge of the flat surface that contacts the fastening material. In addition, the dividing surface of the semi-conical cylinder guide portion is erected along the straight edge with the lower end down, and the recess formed in the straight edge is connected to the semicircular edge of the lower end, It has a base part with a magnetized magnetic body pasted on the surface that abuts the flat fastening material,
The two equally divided split surfaces of the semi-conical cylinders of the two tapping screw tightening assisting members are aligned with each other, and the two tapping screw tightening assisting members are attracted to each other by the magnetic force of the magnetic material attached to the base portion. A tapping screw tightening aid.

Images