JP2013119137A - Removable tool of fastening member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a removable tool of a fastening member capable of surely removing the fastening member by a simple structure and by a simple operation, and usable even in a narrow place.SOLUTION: In the removal tool used for removing the fastening member including a female screw such as a nut, and including a fitting cylinder fittable to an outer periphery of the fastening member, and a rotating operation part formed integrally with the fitting cylinder for rotating the fitting cylinder with respect to the fastening member, the fitting cylinder includes, at its inner wall, a reverse thread cutting die including a plurality of cutting edges for advancing the fastening member into the fitting cylinder while forming a reverse thread in a direction opposite to the female screw at the outer periphery of the fastening member, a pore diameter dimension of the fitting cylinder formed of flanks of the plurality of cutting edges forms a tapered shape diminished from an opening side into which the fastening member advances toward a side opposite thereto, and the reverse thread cutting die includes an abutting part for restricting the advance of the fastening member into the fitting cylinder at a predetermined position.

Description

  The present invention relates to a removal tool for a fastening member having a female thread portion such as a cylindrical nut or a hexagon nut whose outer periphery is damaged.

  For example, when removing a fastening member having a female thread that cannot be used with a spanner, such as a cylindrical nut or a hexagonal nut whose outer periphery is damaged, conventionally, pliers have been used, the nut has been cut, or the bolt has the same diameter as the hole diameter of the nut. The method of opening the hole and removing the nut is adopted. However, the method using pliers is difficult to apply force, and particularly when the fastening member is made of stainless steel or titanium, there is a problem that it is slippery and cannot be easily removed. Further, in the method of cutting a nut or making a hole in a bolt, since a cutter or a drill is used, there is a risk of damaging the bolt and the periphery, and the work must be carefully performed, so that workability is poor. In addition, there are tools that smash the nut from the side and turn it between them, but such tools may also damage the bolt when smashing the nut, so work must be done carefully and workability Is bad. In any of the above methods, the work is difficult or impossible in a narrow place, and cannot be adopted in a place where the work space cannot be secured.

  On the other hand, a dedicated removal tool that can be removed without damaging the fastening member has also been proposed, for example, as in Japanese Translation of PCT International Application No. 2002-524293.

Special table 2002-524293

  However, the conventional dedicated removal tool has a large number of parts and a complicated structure, and uses a ratchet wrench or a wrench. Therefore, the removal work is limited to a place where a large space can be secured. Further, since the removal tool is configured to be locked and rotated by being pressed against the collar (nut), it is difficult to rotate and there is a possibility that the bolts rotate together. Furthermore, when the collar (nut) is made of stainless steel or titanium, the collar (nut) is slippery and may not be locked properly.

  The present invention has been completed based on the above circumstances, and provides a removal tool for a fastening member that can be reliably removed by a simple operation with a simple configuration and can be used even in a narrow place. The purpose is to do.

    The present invention made to solve the above problems is a removal tool for removing a fastening member having a female screw part such as a nut, and a fitting cylinder part that can be fitted to the outer periphery of the fastening member, and this fitting And a rotation operation portion that is provided integrally with the joint tube portion and rotates the fitting tube portion with respect to the fastening member, wherein the fitting tube portion is provided on an inner wall thereof on an outer periphery of the fastening member. And a reverse threading die having a plurality of cutting edges for allowing the fastening member to enter the inside of the fitting tube portion while forming a reverse screw in a direction opposite to the female screw portion. The hole diameter dimension of the fitting tube portion formed by the flank face of the blade has a tapered shape that decreases from the opening side into which the fastening member enters to the opposite side, and the reverse threading die is the fitting thread. Entry of the fastening member into the joint tube Characterized in place with abutment portion for regulating the constant position.

  When using the above-described fastening member removal tool of the present invention, the fitting cylinder portion is fitted on the outer periphery of the fastening member, and the rotation operation portion is rotated, whereby the outer periphery of the fastening member is opposite to the female screw portion. The fastening member is caused to enter the back of the fitting tube portion while forming the reverse screw.

  At this time, since the hole diameter of the fitting cylinder portion formed by the flank surfaces of the plurality of cutting edges is formed in a tapered shape that becomes narrower toward the back, as the fastening member enters the back, the outer diameter of the fastening member is increased. The formed reverse screw is gradually and deeply cut by the cutting edge of the reverse threading die. That is, as the fastening member enters the depth, the force required for threading increases and the rotational torque increases. When the fastening member enters the predetermined position of the fitting tube portion, the rotation torque exceeds the rotation torque required for removing the fastening member, and finally the fitting tube portion and the fastening member are fastened together. It will be rotated in the direction of removing the member (reverse screw direction). Alternatively, even when the rotational torque of the threading does not reach the rotational torque required when removing the fastening member, the fastening member is further advanced into the fitting tube portion when the end of the fastening member comes into contact with the abutting portion of the reverse threading die. Therefore, the threading is stopped, and the fitting tube portion and the fastening member are integrally rotated so as to remove the fastening member.

  Thus, according to the fastening member removal tool of the present invention, the fastening member can be easily removed by a simple operation of fitting the fitting cylinder portion to the fastening member and rotating the screw while cutting.

  Further, at least two or more kinds of the plurality of cutting edges, that is, a first cutting edge having a rake angle capable of threading the fastening member and a second cutting edge having a rake angle giving cutting resistance to the fastening member. You may make it comprise from a cutting blade.

  The specific numerical value of the rake angle at which the fastening member can be threaded varies depending on the material and hardness of the fastening member and the reverse threading die, but in the case of the iron-based fastening member and the reverse threading die, for example, a range of 10 to 25 degrees. Is preferred. If the angle is less than 10 degrees, the sharpness is deteriorated. If the angle exceeds 25 degrees, the blade edge strength is weakened depending on the clearance angle. More preferably, it is good to set it as the range of 15-20 degree | times from a viewpoint of sharpness. On the other hand, in order to give sufficient cutting resistance to a fastening member, it is preferred that a rake angle shall be -3-10 degrees. The second cutting edge acts as a resistance blade that does not actually cut the fastening member, and suppresses the ease of threading by the first cutting edge.

  Furthermore, by using a hexagon nut shape for the rotation operation portion, a general-purpose spanner or the like can be used during the rotation operation, which is convenient.

  According to the fastening member removing tool of the present invention, a simple configuration is not costly, and it is reliable and easy even in a narrow place by a simple operation of fitting the fitting cylinder portion to the fastening member and performing a rotation operation. It is possible to remove the fastening member.

The perspective view of the fastening member removal tool of one Embodiment of this invention Same top view Similarly back view Similarly, AA cross-sectional view of FIG. 2 before the fastening member is fitted. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 2 is a cross-sectional view taken along the line BB in FIG.

  An embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a perspective view of a fastening member removing tool 10 of the present embodiment. The removal tool 10 includes, for example, a fitting cylindrical portion 11 that can be fitted to the outer periphery of a substantially cylindrical nut 20 (corresponding to a fastening member of the present invention), which will be described later, and an axial end of the fitting cylindrical portion 11. It is provided with a hexagon nut-shaped rotation operation portion 12 which is provided integrally and can rotate the fitting cylinder portion 11 about its axis.

  The fitting cylinder portion 11 is formed by forming a general threading die-like hole on one end side of a slightly long metal cylinder made of titanium, for example, as shown in FIGS. 1 and 2. Two cutting edges 13 and four chip holes 14 are alternately provided over the entire circumference of the inner wall surface.

  The cutting edge 13 is configured to be threaded in the reverse direction of a general threading die, thereby forming a reverse threading die 15. Of the four cutting edges 13, adjacent cutting edges 13 have different rake angles, and the opposing cutting edges 13 have equal rake angles. More specifically, the rake angle of one pair of cutting edges 13A, 13A (hereinafter referred to as first cutting edges) facing each other is 10 to 10 so that the outer periphery of the substantially cylindrical nut 20 can be cut well. On the other hand, the rake angle of the other pair of cutting edges 13B, 13B (hereinafter referred to as the second cutting edge) is set to -3 to 10 degrees. It acts as a resistance blade that suppresses the ease of cutting of the substantially cylindrical nut 20 by the first cutting edge 13A.

  The substantially cylindrical nut 20 whose outer periphery is threaded in the reverse screw direction by the reverse threading die 15 is guided substantially along the flank 16 of the reverse threading die 15 to the back of the fitting cylinder portion 11. However, in the removal tool 10 of the present embodiment, the four flank surfaces 16 of the reverse threading die 15 have a hole diameter dimension of the fitting cylinder portion 11 formed by the four flank surfaces 14 as shown in FIG. It is set as the structure which makes a taper shape so that it may become so small in the back (right side in FIG. 4).

  Further, at a position recessed from the open end portion 11A (left side in FIG. 4) of the fitting cylinder portion 11 by a distance equivalent to the length L of the substantially cylindrical nut 20, it is perpendicular to the axis of the fitting cylinder portion 11. An abutting portion 17 having a surface is formed.

  In addition, the fitting cylinder part 11 is provided with a hole 18 penetrating from the abutting part 17 to the end part on the rotation operation part 12 side along the axial direction thereof.

  On the other hand, as shown in FIG. 4, the substantially cylindrical nut 20 has a female screw portion 21 that can be screwed into a male screw portion 31 formed at one end portion of the bolt 30. It has a shape that is partially cut in the circumferential direction.

  Next, the usage method of the removal tool 10 of this embodiment is demonstrated. Here, as shown in FIG. 4, the substantially cylindrical nut 20 attached by screwing the female screw portion 21 to the male screw portion 31 of the bolt 30 inserted into the through hole 101 provided in the workpiece 100. The procedure for removing is described.

  First, the reverse threading die 15 of the fitting cylinder portion 11 of the removal tool 10 is lightly aligned with the outer periphery of the substantially cylindrical nut 20, and the rotation operation portion 12 is rotated about the axis. As a result, the substantially cylindrical nut 20 gradually enters the inner side of the fitting cylinder portion 11 while forming a reverse screw in the opposite direction to the female thread portion 21 of the substantially cylindrical nut 20 on the outer periphery thereof by the first cutting edge 13A. To do. At this time, the plurality of flank surfaces 16 of the reverse threading die 15 are tapered surfaces whose diameters become smaller toward the back, so that the first cylindrical nut 20 enters the fitting tube portion 11 and the first While the depth of the reverse screw formed by the cutting blade becomes deeper, the second cutting blade 13B is strongly pressed against the cylindrical nut 20 to increase the resistance to cutting, and the torque of the rotating operation gradually increases. To rise.

  When the rotation operation unit 12 is further rotated, the threading rotation torque finally exceeds the rotation torque necessary for releasing the screw engagement with the bolt 30 of the substantially cylindrical nut 20, and the fitting cylinder portion 11 and the substantially cylindrical shape are The nut 20 starts to rotate as a unit. Thereby, the substantially cylindrical nut 20 is removed from the bolt 30.

  Even if the rotational torque of the reverse threading die 15 does not exceed the rotational torque required when the screw 30 is released from the bolt 30 of the substantially cylindrical nut 20, the removal tool 10 of the present embodiment has a substantially cylindrical shape. When the nut 20 has entered the rear end surface 20B until it is flush with the open end surface 11A of the fitting cylinder portion 11, the front end surface 20A comes into contact with the abutting portion 17, and further entry (thread cutting) occurs. Since it is set as the structure controlled, the fitting cylinder part 11 and the substantially cylindrical nut 20 will be rotated integrally, and it is possible to remove the substantially cylindrical nut 20 from the bolt 30 reliably. .

  Thus, according to the removal tool 10 of the present embodiment, the substantially cylindrical nut 20 can be removed from the bolt 30 by a simple operation of fitting the removal tool 10 to the outer periphery of the fastening member 20 and rotating the rotation operation unit 12. Can be removed reliably and easily.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

(1) In the above embodiment, the reverse threading die has two types of cutting edges, but it may be configured with only one type of cutting edge that can be threaded. Or it is good also as a structure which has three or more types of cutting blades.

(2) In the above embodiment, two first cutting edges and two second cutting edges are provided, but the number is not limited to the above embodiment. Moreover, you may make it provide a different number of 1st cutting edges and 2nd cutting edges.

(3) In the above embodiment, the distance L from the open end surface of the fitting cylinder portion 11 to the abutting portion 17 is the same length as the length L of the substantially cylindrical nut 20, but the length L of the substantially cylindrical nut 20 is A shorter distance may be used.

(4) The rotation operation unit is not limited to the above-described embodiment, and may have any form such as a gripping unit extending perpendicular to the rotation axis.

10 ... Removal tool (fastening member removal tool)
DESCRIPTION OF SYMBOLS 11 ... Fitting cylinder part 12 ... Rotation operation part 13A ... 1st cutting edge 13B ... 2nd cutting edge 14 ... Chip hole 15 ... Reverse threading die | dye 16 ... Flank 17 ... Butting part 20 ... Substantially cylindrical nut ( Fastening member)
21 ... Female thread 30 ... Bolt 31 ... Male thread

Claims (3)

A removal tool for removing a fastening member having a female thread such as a nut,
A fitting tube portion that can be fitted to the outer periphery of the fastening member, and a rotation operation portion that is provided integrally with the fitting tube portion and rotates the fitting tube portion with respect to the fastening member. In things,
A plurality of cutting blades for allowing the fitting member to enter the inside of the fitting tube part while forming a reverse screw opposite to the female screw part on the outer wall of the fastening member on the inner wall of the fitting tube part Equipped with a reverse threading die with
The hole diameter size of the fitting tube portion formed by the flank surfaces of the plurality of cutting edges has a tapered shape that decreases from the opening side into which the fastening member enters toward the opposite side,
The reverse thread cutting die has an abutting portion for restricting entry of the fastening member into the fitting tube portion at a predetermined position. The plurality of cutting edges include at least two kinds of a first cutting edge having a rake angle capable of threading the fastening member and a second cutting edge having a rake angle that gives a cutting resistance to the fastening member. The fastening tool removing tool according to claim 1, comprising a cutting edge. The fastening member removal tool according to claim 1 or 2, wherein the rotation operation portion has a hexagonal nut shape having an axis along an axial direction of the fitting tube portion.

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