JP2008221354A - Die for thread cutting and machine tool for thread cutting having same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die for thread cutting extended in service life by reducing a cutting torque required for thread cutting to reduce a load applied to the threading edges of the die. <P>SOLUTION: This die comprises a split groove for adjusting the inner diameters of threading die parts where the threading edges are formed, respectively, according to the dimensions of a male screw to be formed on the outer diameter of an article to be threaded. A block changing the inner diameter of the threading die parts into a desired dimension and a dimension enlarged more than the desired dimension is incorporated in the split groove. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a threading die and a threading machine tool provided with the die. More specifically, the present invention relates to a threading die for cutting an external thread on an outer periphery of a threaded article such as a metal round bar or a tube, and a threading machine tool provided with the die.

  As a tool for cutting a male screw on the outer periphery of a metal round bar or tube, there is a die 104 having a plurality of screw mold portions 101 in the center as shown in FIG. 6 and a split groove 102 in one place on the outer periphery. Each of the plurality of screw mold portions 101 has the same shape that is arranged in a concentric circle centered on the center line of the die 104 at equal intervals, and is formed with a thread blade 106 for threading. The number of screw mold parts 101 having the screw blades 106 is usually 3 to 5, and the same number of chip holes 107 as the screw mold parts 101 for discharging chips generated when cutting screws are provided. When the die 104 is used, the die 104 is fixed to a die handle 105 shown by a one-dot broken line, and is manually rotated to cut a male screw.

  An adjustment screw 103 for adjusting the inner diameter of the screw mold portion 101 can be inserted into the split groove 102. By rotating the adjustment screw 103 and changing the width of the split groove 102, the inner diameter of the screw mold portion 101 can be reduced. Can be changed. At this time, the width of the split groove 102 is not fixed by the adjusting screw 103, but the outer diameter does not increase when the threaded article is inserted due to the binding force of the die 104 itself. When a male screw is cut with such a die, the inner diameter of the screw blade 106 is set to a desired dimension of the outer diameter of the article to be threaded by the adjusting screw 103 in advance, and the male screw is formed by one-time cutting. When the external thread has been cut to a predetermined length, the die 104 is reversely rotated to remove it from the threaded article.

  When a male screw is cut by the die 104, a screw shape is formed by one cutting, and therefore a cutting amount necessary for one screw cutting increases. Therefore, a large cutting torque is required, and the load applied to the screw blade 106 of the die 104 is large, which causes the life of the die 104 to be shortened.

  Accordingly, in view of the above circumstances, the present invention provides a threading die that can extend the life of a die by reducing the cutting torque required to cut a screw and reducing the load applied to the screw blade of the die. An object of the present invention is to provide a threading machine tool provided with the die.

  The present invention relates to a die having a split groove for adjusting an inner diameter of a screw mold portion on which a screw blade is formed to a dimension of an external thread formed on an outer diameter of an article to be threaded. It is characterized in that a frame that can be changed into a dimension and a dimension that is larger than a desired dimension is incorporated in the split groove.

The machine tool for threading according to the present invention is characterized by comprising the die, a holder for fixing the die, and a device for rotating the threaded article.

  According to the present invention, it is possible to extend the life of the die by reducing the cutting torque required for cutting the screw and reducing the load applied to the screw blade of the die.

  The dies in the present invention are not limited to those for manual male thread cutting, but can be used for machine tools for cutting male threads. Hereinafter, a threading die of the present invention and a threading machine tool provided with the die will be described in detail with reference to the accompanying drawings. In this embodiment, the piece 3 shown in FIG. 2 is incorporated in the dividing groove 1 of the die 2 as shown in FIG. The split groove 1 is formed with a top-shaped recess that can incorporate the elliptical portion 7 of the top 3 shown in FIG. As shown in FIG. 2, the top 3 includes a handle portion 6 and an ellipse portion 7, and the ellipse portion has a short axis 8 and a long axis 9. In the present embodiment, the top 3 is incorporated from the radial direction in FIG. 1, but the present invention is not limited to this, and it is also possible to incorporate the piece 3 into the split groove from the axial direction. As shown in FIG. 6, when a male screw is cut with a normal die 104, the die 104 is fixed to the die handle 105, the die is brought into contact with the threaded article, and the male screw is rotated while moving in a predetermined circumferential direction. When the male thread is cut to a predetermined length, the die is rotated in the reverse direction to remove it from the threaded article. At this time, the inner diameter of the screw mold portion 101 of the die 104 is always constant.

  In the present embodiment, when the male screw is cut while the die 2 is brought into contact with the article to be threaded and rotated in a predetermined circumferential direction, the short axis 8 of the elliptical portion 7 of the top 3 is set with respect to the section of the split groove 1. In parallel, in other words, the major axis 9 of the elliptical portion 7 is perpendicular to the split groove 1. That is, the inner diameter of the screw mold portion 13 where the screw blade is formed is increased. In this state, the external thread is cut to a predetermined length. When the male thread has been cut to a predetermined length, the top 3 is rotated so that the long axis 9 of the elliptical portion 7 is parallel to the cross section of the split groove 1, and the die 2 is rotated in the reverse direction. Here, the inner diameter of the screw mold portion 13 of the die 2 in a state where the major axis 9 of the elliptical portion 7 is parallel to the cross section of the split groove 1 is the desired inner diameter of the screw mold portion. In this way, by making the inner diameter of the screw mold portion 13 of the die 2 variable in two steps using the top 3, the male screw can be cut into a desired outer diameter in two steps, whereby the die 2 The load on the screw blade and cutting torque can be reduced. The major axis and minor axis length of the ellipse in this embodiment are 2.5 mm and 1.5 mm, respectively, but the minor axis length is set so that the inner diameter of the threaded portion has a desired dimension, The length of the long axis is set so that the initial threading amount is about 40 to 60% of the desired dimension.

  Next, another embodiment of the present invention will be described. In the die according to the present embodiment, the top 3 is incorporated into the split groove from the axial direction. This die can be used for a machine tool that cuts external threads as shown in FIGS. When the die according to the present invention is used in a machine tool, in this embodiment, as shown in FIG. 3, an impact wrench 10 having a hexagon socket 11 fixed to the holder 5 and made movable in the horizontal direction, as shown in FIG. Thus, the threaded article 12 is rotated to cut the male thread. When the male thread has been cut to a predetermined length, the top 3 incorporated in the die 4 is rotated to set the inner diameter of the screw mold portion of the die 4 to a desired dimension, and then the impact wrench 10 is rotated in the reverse direction to complete the threading. . In the present embodiment, the rotation of the frame 3 is performed manually, but this can also be performed automatically. Further, in the present embodiment, the die is fixed and the threaded article is rotated, but the present invention can be similarly applied to the machine tool even if the threaded article is fixed and the die is rotated.

It is a figure which shows the dice | dies concerning this invention which incorporated the elliptical top in the dividing groove. It is an enlarged view of an elliptical frame used in the present invention. It is the state figure which fixed the said die so that it can use for a machine tool with the die concerning the present invention which incorporated an elliptical top from the direction of an axis. It is a machine tool using the die | dye concerning other embodiment of this invention. It is the state figure which has cut the external thread with the machine tool of FIG. It is the state figure which attached the dice which adjusts the width of a split groove with a screw to a dice handle.

Explanation of symbols

1 Split groove 2 Die 3 Top 4 Die 5 Holder 6 Top handle part 7 Top ellipse part 8 Ellipse minor axis 9 Ellipse major axis 10 Impact wrench 11 Hex socket 12 Threaded article 13 Threaded part

Claims (3)

  In a die having a split groove for adjusting the inner diameter of a screw mold portion on which a screw blade is formed to the dimension of an external thread formed on the outer diameter of a threaded article, the inner diameter of the screw mold portion is desired and desired. A threading die characterized in that a frame that can be changed to a dimension that is larger than the above dimension is incorporated in a split groove.   The threading die according to claim 1, wherein the shape of the top is an ellipse. A threading machine tool comprising: the die according to claim 1 or 2; a holder for fixing the die; and a device for rotating the threaded article.