Raised tap and threading method

Abstract

This product provides a raised tap that allows for the reliable removal of seams. [Solution] The shape of the removal portion storage section 12 is such that the entire seam em is located below the cutting position line 10, and has a right-side space portion +a that extends to the right beyond the right-side V-shaped line Ka and a left-side space portion +b that extends to the left beyond the left-side V-shaped line Kb. The diameter of the pilot hole into which the threads are tapped is such that the amount of the removal portion E realizes the seam position shape that extends beyond the cutting position line, and the tap is used to tap a pilot hole of the pilot hole diameter that realizes the seam position shape that extends beyond the V-shaped line.

Description

Technical Field

[0001] The present invention relates to a raising tap (non-cutting tap, swaging tap, roll tap) having a cutting edge for cutting (trimming) a removal site having a seam (crack or joint due to double thread, depression, etc.) formed at the thread crest of an internal thread formed by plastic deformation of a pilot hole during a rotational operation after the tapping operation is completed, and a tapping method.

Background Art

[0002] Conventionally, a raising tap having a cutting edge for cutting a removal site having a seam formed on the crest side of a formed internal thread during a reverse rotational operation (return operation) or a forward rotational operation (tapping operation) is known. (For example, the invention of Patent Document 1)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [Definition] As shown in FIG. 4 of Example 1 of the present invention, the height distance of the ridge from the ridge top Ta to the ridge bottom Tb is defined as H, the line connecting the ridge top Ta and the ridge bottom Tb of the ridge is defined as the mountain-shaped line K, the mountain-shaped line located on the right side of the mountain-shaped line K is defined as the right mountain-shaped line Ka, the mountain-shaped line K located on the opposite side of the right mountain-shaped line Ka is defined as the left mountain-shaped line Kb, The upper intersection of the right mountain-shaped line Ka and the left mountain-shaped line Kb is the ridge top Ta, and the lower intersection is the ridge bottom Tb. The description will be made with the ridge top Ta side as the upper side and the ridge bottom Tb side as the lower side. In a metric coarse thread, the thread profile K is a straight line with an inclination angle of 30 degrees. Therefore, the inclination angles of the right-side wall of the thread (the right side wall of the thread) and the left-side wall of the thread (the opposite left side wall) are both 30 degrees.

[0005] [Invention of Patent Document 1] The invention described in Patent Document 1 does not provide any description of the size (expressed in cross-sectional area) of the removal part storage section, which is the space for storing the removal part. It is reasonable to infer the shape of its cross-sectional size from Figures 5 to 7 of Patent Document 1. However, in the description in Figures 5 to 7 of Patent Document 1, the root of the tap (root of the male thread) is set at a position H / 6 from the root of the pointed crest Tb, and the apex of the formed female thread is set at a position H / 4 (reference dimension of the reference crest shape) from the root of the pointed crest Tb (position of the cutting blade (position of "reamer 16" in Patent Document 1)). Accordingly, the form of the removal portion storage section in the invention of Reference Document 1 is such that the height spatial distance is the distance from (position H / 6 from the bottom of the valley Tb of the pointed peak) to (position H / 4 from the bottom of the valley Tb of the pointed peak), the right side wall is positioned on the right side V-shaped line Ka, and the left side wall is positioned on the left side V-shaped line Kb, and the space (cross-sectional space) is the removal portion storage section, and it is characterized by a reduced storage section spatial form in which the left and right side walls narrow linearly downwards with an inclination of 30 degrees each, that is, a reduced storage section spatial form in which the direction of plastic deformation flow narrows rapidly. Therefore, the invention of Patent Document 1 addresses the technical problem of removing the removal portion that is formed (occurs, arises) in the threading and internal thread formation of a standard thread profile and standard dimension raised tap.

[0006] The invention described in Patent Document 1 had the following problems: (1) The problem was that increasing the snagging rate tended to leave more seams (in fact, at a snagging rate of 90% to 95%, some or no seams often remained, while at a snagging rate of 100% to 105%, seams often remained firmly). This is because the removal portion storage area has a spatial configuration that narrows in the direction of flow, formed by the right-hand thread wall and the left-hand thread wall of the opposing side of the steeply inclined 30-degree surface of the plastic deformation flow. In particular, as it progresses towards the tip, the pressure pushing inward from both sides increases, so an upward force or a force that prevents flow and progression downward acts on the inside of the tip of the plastic deformation portion. This means that an upward force or a force that prevents downward flow is generated against the seam that is formed on the inside of the tip of the plastic deformation portion. Therefore, it is thought that a portion of the seam remains above the position H / 4 from the bottom of the crest Tb (the position of the cutting blade). It is thought that this is why increasing the engagement rate (reducing the diameter of the pilot hole) increases the amount of plastic deformation flow and strengthens the tendency for seam to remain at the crest of the female thread. (2) As described in (1) above, the closer the pilot hole diameter is to the maximum pilot hole diameter of the dimensional tolerance, the less plastic deformation flow there is, which increases the tendency for a seam to remain. The closer the pilot hole diameter is to the minimum pilot hole diameter of the dimensional tolerance, the more plastic deformation there is, which increases the tendency for a seam to remain. Therefore, the pilot hole diameter must be strictly controlled with high precision to the optimal pilot hole diameter (for example, controlled with high precision to less than 1 / 3 of the dimensional tolerance of the reference thread shape (the theoretical thread shape defined by the theoretical dimensions and angles shared by the internal and external threads in a cross-section including the axis)). However, even when strictly controlled to less than 1 / 3 of the dimensional tolerance, there are still problems such as the presence of a small amount of seam remaining in the internal thread portion, or the presence of a crack line (included in "seam" in this application) in a tightly packed form where the left and right inner walls of the seam recess butt together. (3) The removal portion storage area (the gap in the thread root of the tap) is an extremely narrow removal portion storage space, which is an inverted trapezoidal shape with a height distance from position H / 6 to position H / 4, the right wall positioned on the right V-line Ka, and the left wall positioned on the left V-line Kb. Therefore, with a pilot hole smaller than the minimum pilot hole diameter, a plastic deformation flow occurs to fill the narrow removal portion storage space, completely filling the removal portion storage space. In this case, the threading friction increases dramatically, resulting in a high-friction or locked state, and in the worst case, there is a risk of the tap breaking. Furthermore, if the pilot hole is tilted, a certain amount of plastic deformation flow occurs in some areas, filling the narrow space containing the removal area, which has the disadvantage of potentially causing the tap to break in the worst case. (4) As described in (1), (2), and (3) above, the raised tap invention of Patent Document 1 requires strict, highly precise control of the pilot hole (for example, control to a high degree of precision of 1 / 3 or less of the dimensional tolerance of the reference thread), which has the problem of being costly and having poor productivity. Furthermore, making the pilot hole diameter smaller than the minimum pilot hole diameter of the dimensional tolerance would greatly increase the risk of creating a removal area that exceeds the storage capacity of the narrow removal area storage section, making it virtually impossible. Furthermore, even when the pilot hole was controlled to be less than 1 / 3 of the dimensional tolerance, a crack line or joint in the form of a tight seal where the left and right inner walls of the seam butted together almost always remained, which was a problem.

[0007] In view of the drawbacks of the prior art described above, the present invention provides a raised tap having a cutting blade for removing a portion formed on the crest side of an internal thread, (1) The objective is to provide a raised tap that can reliably remove areas with seams (cracks or joints caused by double threads, indentations, etc.) and form female threads without leaving any seams. (2) The objective is to provide a raised tap that enables the formation of female threads without seams, even in pilot holes that do not undergo strict and high-precision control (pilot holes that are highly productive and low-cost). (3) The objective is to provide a threading method using the raised tap described in (1) and (2) above. [Means for solving the problem]

[0008] The present invention has the following configuration. [Invention 1] In a raising tap having a cutting blade that cuts off a portion of the female thread that may form a seam on the crest side of the female thread formed by threading due to plastic deformation of the pilot hole during the rotational operation after threading, With the peak (Ta) side of Togariyama facing upwards, With the valley floor (Tb) of Togariyama facing downwards, Let H be the height of the pointed mountain, which is the height distance from the top of the pointed mountain (Ta) to the bottom of the valley (Tb) of the pointed mountain. Let the line connecting the peak (Ta) of the aforementioned pointed mountain and the valley floor (Tb) of the aforementioned pointed mountain be the mountain line (K). Of the aforementioned Yamagata Line (K), the Yamagata Line located on the right side shall be referred to as the Right Yamagata Line (Ka). The mountain-shaped line (K) located on the opposite side of the right mountain-shaped line (Ka) is referred to as the left mountain-shaped line (Kb). A space for storing the removed portion is formed below the cutting position line indicating the cutting position of the cutting blade, and a removed portion storage section (12) is provided, with the bottom of which is the bottom of the storage section (12f). The shape of the removal portion storage section (12) is such that the entire seam is located below the cut line, and the shape is one of the following (a) or (b): The diameter of the pilot hole into which the threads are threaded is such that the amount of plastic flow in the removed portion is such that the pilot hole diameter for achieving a seam position shape that exceeds the cut line is such that the pilot hole diameter for achieving a seam position shape that exceeds the cut line is such that the tap threads the pilot hole of the pilot hole diameter for achieving a seam that exceeds the cut line. A distinctive raised tap. (a) A form having a right-side space portion (+a) which extends to the right beyond the right-side mountain line (Ka), and a left-side space portion (+b) which extends to the left beyond the left-side mountain line (Kb). (i) A form having a right-side space portion (+a) which is a space extending to the right beyond the right-side curved line (Ka), or a form having a left-side space portion (+b) which is a space extending to the left beyond the left-side curved line (Kb). [Invention 2] The raised tap according to Invention 1, characterized in that the position of the bottom (12f) of the storage section is one of the following positions (a) to (h). (a) A position approximately H / 6 or less than H / 6 from the bottom of the valley (Tb) of the aforementioned pointed mountain. (i) A position approximately H / 7 or less than H / 7 from the bottom of the valley (Tb) of the aforementioned pointed mountain. (c) A position approximately H / 8 or less than H / 8 from the bottom of the valley (Tb) of the aforementioned pointed mountain. (e) A position approximately H / 9 or less than H / 9 from the valley floor (Tb) of the aforementioned pointed mountain. (e) It is in approximately the same location as the valley floor (Tb) of the aforementioned pointed mountain. [Invention 3] The raised tap according to either Invention 1 or 2, characterized in that the shape of the removal portion storage section (12) is either (a) or (b) below. (a) All or part of the right wall (12a) that forms the right-side space portion (+a) beyond the curved line and the left-side wall (12b) that forms the left-side space portion (+b) beyond the curved line are substantially vertical walls. (i) All or part of the right-side wall (12a) forming the right-side space portion (+a) beyond the mountain line is a substantially vertical wall, or all or part of the left-side wall (12b) forming the left-side space portion (+b) beyond the mountain line is a substantially vertical wall. [Invention 4] The optimum pilot hole diameter for the raised tap of the reference profile is defined as the reference profile optimum pilot hole diameter, the minimum pilot hole diameter for the raised tap of the reference profile is defined as the reference profile minimum pilot hole diameter, and the maximum pilot hole diameter for the raised tap of the reference profile is defined as the reference profile maximum pilot hole diameter. In this case, the maximum pilot hole diameter of the seam exceeding the peak line realization pilot hole diameter, or the maximum and minimum pilot hole diameters of the seam exceeding the peak line realization pilot hole diameter, are any of the following (a) to (e). The raised tap according to any one of Inventions 1 and 2, characterized in that. (a) The maximum pilot hole diameter of the seam exceeding the peak line realization pilot hole diameter is approximately the reference profile optimum pilot hole diameter or less than the reference profile optimum pilot hole diameter. (i) The maximum pilot hole diameter of the seam exceeding the peak line realization pilot hole diameter is a pilot hole diameter approximately in the middle between the reference profile optimum pilot hole diameter and the reference profile minimum pilot hole diameter. (c) The maximum pilot hole diameter of the seam exceeding the peak line realization pilot hole diameter is approximately the reference profile optimum pilot hole diameter or less than the reference profile optimum pilot hole diameter, and the minimum pilot hole diameter of the seam exceeding the peak line realization pilot hole diameter is less than or equal to the reference profile minimum pilot hole diameter or less than the reference profile minimum pilot hole diameter. (e) The maximum pilot hole diameter of the seam exceeding the peak line realization pilot hole diameter is a pilot hole diameter approximately in the middle between the reference profile optimum pilot hole diameter and the reference profile minimum pilot hole diameter, and the minimum pilot hole diameter of the seam exceeding the peak line realization pilot hole diameter is less than or equal to the reference profile minimum pilot hole diameter or less than the reference profile minimum pilot hole diameter. [Invention 5] In a form having no space exceeding the right profile line (Ka) above the cutting position line. In a form having no space exceeding the left profile line (Kb) above the cutting position line. The raised tap according to any one of Inventions 1 and 2, characterized in that. [Invention 6] The removed part storage part (12) is provided at a lower position away from the cutting position line. Between the cutting position line and the removed part storage part (12), a female thread extension forming part (Q) formed substantially on the lines of the right profile line (Ka) and the left profile line (Kb) is provided to enable the extension formation of the female thread of the formed female thread. The position in which the entire seam is located is a position less than the lowest position line (18) of the female thread extension forming portion (Q), which is a seam position shape that exceeds the cut position line. By forming the cutting blade (the position of the cutting line) at a small diameter position within the female thread extension forming portion (Q), it is possible to form a female thread with a high engagement rate. A swelling tap according to either invention 1 or 2, characterized by the above. [Invention 7] The raised tap according to either Invention 1 or 2, characterized in that the cutting blade has a first cutting blade for removing a portion of the removal area and a second cutting blade for removing the remaining removal area after removal by the first cutting blade. [Invention 8] A workpiece setting step of setting a workpiece in a threading device, which has a pilot hole formed in the pilot hole diameter for achieving a seam beyond the crest line as described in either Invention 1 or 2, and which can be threaded by a raised tap as described in either Invention 1 or 2, A threading step of threading the pilot hole having the pilot hole diameter for achieving the seam beyond the crest line using a raised tap according to either Invention 1 or 2, A threading method characterized by having the following features. [Invention 9] A workpiece setting step of setting a workpiece in a threading device, which has a pilot hole formed in the pilot hole diameter for achieving a seam exceeding the crest line as described in Invention 3, and which can be threaded by the raised tap described in Invention 3, The tapping step of threading the pilot hole of the pilot hole diameter for achieving the seam beyond the crest line, using the raised tap described in Invention 3, A threading method characterized by having the following features. [Invention 10] A workpiece setting step of setting a workpiece in a threading device, which has a pilot hole formed in the pilot hole diameter that achieves a seam exceeding the crest line as described in Invention 4, and which can be threaded by the raised tap described in Invention 4, The tapping step of threading the pilot hole of the pilot hole diameter for achieving the seam beyond the crest line, using the raised tap described in Invention 4, A threading method characterized by having the following features. [Invention 11] A workpiece setting step of setting a workpiece in a threading device, which has a pilot hole formed in the pilot hole diameter for achieving a seam exceeding the crest line as described in Invention 5, and which can be threaded by the raised tap described in Invention 5, The tapping step of threading the pilot hole of the pilot hole diameter for achieving the seam beyond the crest line, using the raised tap described in Invention 5, A threading method characterized by having the following features. [Invention 12] A workpiece setting step of setting a workpiece in a threading device, which has a pilot hole formed in the pilot hole diameter for achieving a seam exceeding the crest line as described in Invention 6, and which can be threaded by the raised tap described in Invention 6, The tapping step of threading the pilot hole of the pilot hole diameter for achieving the seam beyond the crest line, using the raised tap described in Invention 6, A threading method characterized by having the following features. [Invention 13] A workpiece setting step involves setting a workpiece in a threading device a workpiece having a pilot hole with a pilot hole diameter that exceeds the crest line seam, as described in Invention 7, which is capable of threading using the raised tap described in Invention 7, The tapping step of threading the pilot hole of the pilot hole diameter for achieving the seam beyond the crest line, using the raised tap described in Invention 7, A threading method characterized by having the following features. [Effects of the Invention]

[0009] (1) The shape of the removal portion storage section (12) is such that the entire seam is located below the cut line, thereby realizing a seam position shape that crosses the cut line, and is one of the following shapes (a) or (b): The diameter of the pilot hole into which the threads are threaded is such that the amount of plastic flow in the removed portion is such that the pilot hole diameter for achieving the seam position shape beyond the cut line is such that the removed portion is such that the tap threads the pilot hole diameter for achieving the seam position shape beyond the cut line. (a) A form having a right-side space portion (+a) which extends to the right beyond the right-side mountain line (Ka), and a left-side space portion (+b) which extends to the left beyond the left-side mountain line (Kb). (i) A form having a right-side space portion (+a) which is a space extending to the right beyond the right-side curved line (Ka), or a form having a left-side space portion (+b) which is a space extending to the left beyond the left-side curved line (Kb). Since the raised tap is characterized by being configured as described above, This achieves the effect of creating a female thread without seams (cracks, joints, or indentations caused by double threads). (2) The form of the removal portion storage section (12) is such that it has a space portion to the right of the Yamagata Line crossing (+a) and a space portion to the left of the Yamagata Line crossing (+b), or has either one of them. Since a removal part storage section (12) with a larger storage capacity than the removal part storage section in the conventional standard crest shape has been realized, a removal part storage section configuration has been realized that can accommodate the amount of plastic deformation flow for threading with a pilot hole diameter smaller than the minimum pilot hole diameter in the standard crest shape with ample room to spare. As the plastic deformation flow progresses towards the tip, the sidewall side advances first, and consequently the inner side slows down, resulting in the formation of a seam (em) at the tip. However, when the tip flow portion enters the removal portion storage section (12), it flows from a space with a narrowing angle to a space with a widening angle, reducing the pressure acting on the inside of the tip of the plastic deformation flow and widening the opening of the seam (em). As the pressure that was hindering the flow progresses is suddenly reduced, the bottom of the seam (em) progresses, and a shallow seam (em) is formed where the bottom of the seam (em) extends below the cut line (in some cases, a form in which the seam almost disappears may occur). The aforementioned 、 This makes it possible to thread pilot holes smaller in diameter than the minimum pilot hole diameter of the standard thread profile, expanding the dimensional tolerance range of the pilot hole. As a result, even with pilot holes that do not require strict and high-precision control (pilot holes that are highly productive and low-cost), it is possible to form female threads without leaving any seams.

[0010] Invention 6 provides the effect of forming a female thread with a high thread (high grip rate) by, for example, if the cutting position line is a standard crest-shaped female thread (with the crest of the thread at H / 4), forming a small-diameter cutting blade with a smaller diameter than the cutting position line within the range of the female thread extension forming portion (Q). [Brief explanation of the drawing]

[0011] [Figure 1] A plan view of Embodiment 1 of the present invention. [Figure 2] A partially enlarged plan view of Example 1 of the present invention. [Figure 3] An enlarged front view of Embodiment 1 of the present invention. [Figure 4] A partially enlarged cross-sectional view of Example 1 of the present invention. [Figure 5] A partially enlarged cross-sectional view showing an example of the plastic deformation state of Embodiment 1 of the present invention. [Figure 6] A partially enlarged cross-sectional view showing an example of the plastic deformation state of Embodiment 2 of the present invention. [Figure 7] A partially enlarged cross-sectional view of Example 3 of the present invention. [Figure 8] A partially enlarged cross-sectional view of Embodiment 4 of the present invention. [Figure 9] A plan view of Embodiment 5 of the present invention. [Figure 10] An enlarged front view of Embodiment 5 of the present invention. [Figure 11] A plan view of Embodiment 6 of the present invention. [Figure 12] An enlarged front view of Embodiment 6 of the present invention. [Modes for carrying out the invention]

[0012] The following describes embodiments that represent the best mode for carrying out the present invention. However, the present invention is not intended to be limited to these embodiments only. Furthermore, in describing the embodiments described later, the same reference numerals are used for the same components as in the embodiments described above, and redundant explanations are omitted. [Examples]

[0013] In Embodiment 1 of the present invention shown in Figures 1 to 5, the ridge tap 1 has the configuration described below. The raised tap 1 consists of a shank portion 2, a complete thread portion 3 following the shank portion, a tip-end cutting portion 4 following the cutting portion, a first cutting blade 5a formed on the side of the cutting portion 4, and a second cutting blade 5b that performs the cutting of the remaining material not cut by the first cutting blade 5a after the cutting by the first cutting blade 5a. The threaded portion 6 is formed by the fully threaded portion 3 and the engagement portion 4. The threaded portion 6 is provided with threaded sections 7a to 7f and oil grooves 11a to 11f formed between the threaded sections. Numerous threads 8, which are raised parts of the female thread 20, are arranged in the threaded sections 7a to 7f.

[0014] The cutting blade is, The cutting blade is provided at the engagement portion 4 of the thread group 7a (or other thread group), and is a reamer-shaped cutting blade that cuts off the removal portion E formed on the top side of the female thread 20 during the return operation (reverse rotation). It has a first cutting blade 5a that first removes a portion of the removal portion E, and a second cutting blade 5b that removes the remaining removal portion after it has been removed by the first cutting blade 5a. The cutting resistance of the cutting blade is reduced, improving the durability of the cutting function and resulting in a smooth female thread crest 20a.

[0015] Here, the excision is performed using two excision blades, and the excision thickness of one of the excision blades is made thinner to increase the durability of the excision blade. However, a configuration using only one excision blade, the second excision blade 5b, is also acceptable. The cutting blade should be positioned as close to the tip as possible if the pilot hole is a blind hole. If the pilot hole is a nut or through hole, it may be positioned in the middle of the complete thread portion 3 or closer to the shank portion 2.

[0016] A removal portion storage section 12 is provided, which is a space for storing the removal portion E formed below the cutting position line 10 (= position of the female screw thread crest 20a that is formed) that indicates the cutting position of the second cutting blade 5b, with the bottom of the storage section 12f being the bottom of the storage section. The shape of the removal portion storage section 12 is such that the entire seam em is located below the resection line 10, thereby realizing a seam position configuration that crosses the resection line. The raised tap 1 is a tap that taps a pilot hole (not shown, omitted) into which threads are to be threaded, where the diameter of the pilot hole (not shown) is such that the amount of plastic deformation flow in the portion to be removed is equal to the diameter of the pilot hole that realizes the seam position shape beyond the cut line, thereby achieving the seam position shape beyond the cut line. The removal portion storage section 12 may be formed in some or all of the valleys of the gripping section 12.

[0017] The shape is such that there is no space above the resection line 10 that extends beyond the right-side V-shape line Ka, and there is no space above the resection line 10 that extends beyond the left-side V-shape line Kb. In this case, the form of the removal portion storage section 12 that realizes a seam position configuration beyond the cutting position line, which is a plastic flow configuration in which the entire seam em is located below the cutting position line 10, is the form shown in Figure 4.

[0018] The removal part storage section 12 is The bottom 12f of the storage section is defined as the position approximately H / 6 or less than H / 6 to H / 7 from the position of the cutting line 10 or a position slightly below the cutting line 10. It is a form that has a space portion +a that extends to the right beyond the Yamagata Line Ka on the right side, which is the space to the right beyond the Yamagata Line. It has a form that includes a space portion +b that extends to the left beyond the Yamagata Line Kb on the left side, which is the space to the left of the Yamagata Line. The right wall 12a and the left wall 12b are roughly vertical walls, resulting in a roughly rectangular cross-sectional shape. The position of the female thread crest 20a, which is the peak of the female thread 20, is the position of the cutting position line 10 set at the position of H / 4 (the standard dimension of the standard thread shape), and is the position of the second cutting blade 5b.

[0019] Plastic deformation flow will be explained primarily with reference to Figure 5. The plastic deformation flow flows along the right side wall 8a and the left side wall 8b of the screw thread. However, because the side wall shape narrows at a 30-degree angle as it goes downwards, the flow progresses faster along the side wall as it approaches the tip, and consequently, the flow on the inside slows down, resulting in the formation of a seam em at the tip. However, when the tip flow portion enters the removal portion storage section 12, it flows from the narrowing space at a 30-degree angle into the widening space of a nearly vertical wall. As a result, the pressure acting on the inside of the tip of the plastic deformation flow is reduced, and the opening of the seam em widens. The pressure that was hindering the flow progresses rapidly, causing the bottom of the seam em to progress, and a shallow seam em is formed where the bottom of the seam em extends below the cut position line 10 (in some cases, a form in which the seam almost disappears may occur).

[0020] The rotational motion after threading causes the cutting blade 50b to cut the removal area E at the position of the cutting line 10 (H / 4), forming a female thread crest 20a with no seam whatsoever.

[0021] The form of the removal section storage section 12 may also be one that has a space section +a on the right side of the Yamagata Line crossing and does not have a space section +b on the left side of the Yamagata Line crossing. Furthermore, it is also acceptable for the form of the right-side space portion +a and the left-side space portion +b to be different (for example, the side wall of the right-side space portion +a is approximately vertical (approximately 90 degrees), while the side wall of the left-side space portion +b has an inclination angle of 60 degrees or so).

[0022] The position of the bottom 12f of the storage section 12 of the removal section storage section 12 may be in one of the following forms (a) to (e). (a) Located approximately H / 6 or less than H / 6 from the valley floor Tb of Togariyama. (i) Located approximately H / 7 or less than H / 7 from the valley floor Tb of Togariyama. (c) A position approximately H / 8 or less than H / 8 from the bottom of the valley of Togariyama (T). (e) Located approximately H / 9 or less than H / 9 from the valley floor Tb of Togariyama. (O) It is in approximately the same location as the bottom of the valley Tb of Togariyama.

[0023] [Pilot hole diameter] When the optimal pilot hole diameter for the raised tap of the standard crest is defined as the optimal pilot hole diameter for the standard crest, the minimum pilot hole diameter for the raised tap of the standard crest is defined as the minimum pilot hole diameter for the standard crest, and the maximum pilot hole diameter for the raised tap of the standard crest is defined as the maximum pilot hole diameter for the standard crest, it is preferable that the maximum pilot hole diameter within the dimensional tolerance for the pilot hole diameter that achieves a seam beyond the crest line, or the maximum and minimum pilot hole diameters within the dimensional tolerance for the pilot hole diameter that achieves a seam beyond the crest line, be one of the following (a) to (d). (a) The maximum pilot hole diameter for achieving the seam beyond the peak line is approximately the same as or less than the optimal pilot hole diameter for the standard peak shape. (i) The maximum pilot hole diameter for achieving the seam beyond the peak line is approximately midway between the optimal pilot hole diameter for the standard peak shape and the minimum pilot hole diameter for the standard peak shape. (c) The maximum pilot hole diameter for achieving the seam beyond the peak line is approximately the optimal pilot hole diameter for the standard peak shape or less than the optimal pilot hole diameter for the standard peak shape, and the minimum pilot hole diameter for achieving the seam beyond the peak line is less than or equal to the minimum pilot hole diameter for the standard peak shape or less than the minimum pilot hole diameter for the standard peak shape. (e) The maximum pilot hole diameter for achieving the seam beyond the peak line is approximately midway between the optimal pilot hole diameter for the standard peak shape and the minimum pilot hole diameter for the standard peak shape, and the minimum pilot hole diameter for achieving the seam beyond the peak line is less than or equal to the minimum pilot hole diameter for the standard peak shape.

[0024] [Screwing method] The desired threading and internal thread formation are achieved by the following threading method. A workpiece setting step involves setting a workpiece in a threading device a workpiece having a pilot hole formed with the pilot hole diameter for achieving a seam exceeding the crest line, which can be threaded using a raised tap 1. A threading method comprising: a threading step of threading a pilot hole of the pilot hole diameter for achieving a seam that exceeds the crest line using a raised tap 1. [Examples]

[0025] The main difference between Embodiment 2 shown in Figure 6 and Embodiment 1 is that the removal section storage section 12 is provided at a lower position away from the cutting position line 10 (distance H / 4) (here, the bottom 12f of the storage section is set to H / 7, and the upper parts of the right side wall 12a and left side wall 12b are set to H / 5.5). Between the excision position line 10 and the removal site storage section 12, a female thread extension forming section Q (with a distance width of H / 4 to H / 5.5) is provided, which is formed on the approximate lines of the right-side V-shaped line Ka and the left-side V-shaped line Kb, enabling the formation of extended female threads (forming higher threads). By forming at least the position of the second cutting blade 5b (position of the cutting line) at a small-diameter position (for example, small-diameter cutting line 10a) within the female thread extension forming portion Q, it is possible to form a female thread with a high grip rate and no seam em. The position where the entire seam em is located is below the lowest position line 18 (here, the position at H / 5.5) of the female thread extension forming portion Q, which is the seam position shape that crosses the cut line.

[0026] The pilot hole should have a diameter such that plastic deformation flow occurs when the seam em is located below the H / 5.5 position. The pilot hole diameter needs to be determined considering factors such as the properties and characteristics of the workpiece, the tap diameter, the toughness of the tap, the surface treatment of the tap, friction resistance, and whether or not coolant is used. In practice, it is best to determine the optimal pilot hole diameter (including dimensional tolerances) by actually threading the pilot hole in the workpiece.

[0027] [This makes it possible to form the cutting blade at a position that achieves the target catch rate.] To meet the demands of customers who desire an increased grip rate, a raised tap can be provided in which at least the position of the second cutting blade 5b is formed at a position where the grip rate is achieved (for example, the position of the small-diameter cutting line 10a). In other words, by forming the cutting blades at different positions within the range of the female thread extension forming portion Q, it is possible to form female threads with different grip rates. [Examples]

[0028] In Embodiment 3 of the present invention shown in Figure 7, the main difference from Embodiment 1 is that the removal portion storage section 12 is provided approximately directly below the cutting position line 10, and its connecting portion is a curved connection form with a right-side curved section 14a and a left-side curved section 14b, and the connection between the bottom 12f of the storage section and the right-side wall 12a (approximately vertical wall) and the left-side wall 12b (approximately vertical wall) is a curved connection form, and the position of the bottom 12f of the storage section is at the H / 8 position. The curved connection configuration, with a right-side curved section 14a and a left-side curved section 14b, reduces resistance when the leading edge of the plastic deformation flow flows into the removal section storage section 12, and also reduces resistance to subsequent inflow. A similar shape can be obtained through the wear of the grinding wheel that forms the thread grooves (thread roots) of the tap, and the curve (curvature) becomes larger as wear progresses. [Examples]

[0029] The main difference between Embodiment 4 of the present invention shown in Figure 8 and Embodiment 1 is that the right side wall 12a is inclined at approximately 15 degrees, the left side wall 12b is inclined at approximately 15 degrees, and the position of the bottom 12f of the storage compartment is at position H / 7. [Examples]

[0030] The main difference between Embodiment 5 of the present invention, shown in Figures 9 and 10, and Embodiment 1 is that the following are: The thread group section is divided into five thread group sections, thread group section 7b to thread group section 7f. The threaded portion 7a is left as a straight thread without threads, In Example 1 (see mainly Figure 3), the oil groove 11f, which was formed between the threaded section 7a and the threaded section 7f, was widened to approximately 2 / 3 the width of the straight thread, resulting in an oil groove 11fh, and a protrusion 13 was formed (remained) between the oil groove 11a and the oil groove 11fh. A cutting blade portion 17 is provided at the upper tip of the protrusion 13, located outside (outer circumference) of the upper surface of the protrusion 13. A cutting blade 5 is provided at the leading edge in the direction of travel when the cutting blade portion 17 is rotated in the reverse direction. A coolant supply groove 15b is provided on the outer circumference of the shank portion 2, which is connected to the oil groove 11b and supplies coolant to the oil groove 11b. A coolant supply groove 15e is provided on the outer circumference of the shank portion 2, which is connected to the oil groove 11e and supplies coolant to the oil groove 11e. In the tapping and reverse rotation (pulling) operations of blind holes, the oil grooves 11a, 11c, 11d, and 11fh are formed as raised taps 1a that function as coolant discharge grooves for discharging the coolant supplied to the coolant supply grooves 15b and 15e. When the pilot hole is a blind hole, the chips cut by the cutting blade 5 are mainly forcibly discharged from the opening of the pilot hole through the oil groove 11fh by coolant flowing into the oil groove 11fh from its tip side. The excision blade 5 may be an inclined blade or a curved blade. The oil groove 11fh and the protrusion 13 may also be formed by first forming the threaded section 7a in Example 1 (mainly see Figure 3), and then machining the threaded section 7a portion. [Examples]

[0031] The main difference between Embodiment 6 of the present invention, shown in Figures 11 and 12, and Embodiment 1 is that, The thread group section is divided into five thread group sections, thread group section 7b to thread group section 7f. In Example 1 (see mainly Figure 3), the threaded portion 7a is in the form of a straight thread without threads. In Example 1 (see mainly Figure 3), the oil groove 11f formed between the threaded section 7a and the threaded section 7f was widened to approximately 1 / 3 the width of the straight thread, resulting in an oil groove 11afh. In Example 1 (see mainly Figure 3), a protrusion 13 is located between the oil groove 11a and the oil groove 11afh. b and the protrusion 13 b An oil groove 11g is provided in the direction of travel when the device is rotating in the reverse direction. The oil groove 11g has a protrusion 13 in the direction of travel when it rotates in the reverse direction. a We have established A cutting blade portion 17a is provided at the upper tip of the protrusion 13a, located outside (outer circumference) of the upper surface of the protrusion 13a. A first cutting blade 5a is provided at the tip angle in the direction of travel when the cutting blade portion 17a is rotated in the reverse direction. A cutting blade portion 17b is provided at the upper tip of the protrusion 13b, located outside (outer circumference) of the upper surface of the protrusion 13b. A second cutting blade 5b is provided at the leading edge in the direction of travel when the cutting blade portion 17b is rotated in the reverse direction, and is positioned inside (inner circumference) of the first cutting blade 5a to perform the remaining cutting of the cutting portion following the cutting of the first cutting blade 5a. A coolant supply groove 15b is provided on the outer circumference of the shank portion 2, which is connected to the oil groove 11b and supplies coolant to the oil groove 11b. A coolant supply groove 15e is provided on the outer circumference of the shank portion 2, which is connected to the oil groove 11e and supplies coolant to the oil groove 11e. A coolant supply groove 15afh is provided on the outer circumference of the shank portion 2, which is connected to the oil groove 11afh and supplies coolant to the oil groove 11afh. In the tapping and reverse rotation (pulling) operations of blind holes, the oil grooves 11c and 11d are configured to function as coolant discharge grooves that discharge the coolant supplied to the coolant supply grooves 15afh, 15b, and 15e, and a raised tap 1a is formed accordingly. The chips cut by the first cutting blade 5a and the chips cut by the second cutting blade 5b are forcibly discharged from the opening of the pilot hole by coolant flowing in from the tip side of the oil grooves 11c and 11d. The cutting blade may be an angled blade or a curved blade. The oil groove 11afh and the protrusions 13a and 13b may also be formed by first forming the threaded section 7a in Example 1 (see mainly Figure 3), and then machining the threaded section 7a. [Industrial applicability]

[0032] This invention is used in industries that manufacture or use taps. [Explanation of Symbols]

[0033] Ta: The top of Togariyama, Tb: The bottom of the valley of Togariyama, K: Yamagata Line, Ka: Right side Yamagata Line, Kb: Left side Yamagata line, +a: Space on the right side beyond the Yamagata Line +a, +b: Space on the left side beyond the Yamagata Line +b, E: Removal site, Q: Female thread extension forming part, em: seam, 1, 1a, 1b: Boost tap, 2: Shank section, 3: Complete thread section, 4: Food attachment section, 5: Cutting blade, 5a: First resection blade, 5b: Second excision blade, 6: Threaded part, 7a~7f: Thread group section, 8: Screw thread, 8a: Right side wall of the screw thread, 8b: Left side wall of the screw thread, 10: Resection position line, 10a: Small diameter resection position line, 11a~11f, 11fh, 11afh, 11g: Oil groove, 12: Removal part storage section, 12a: Right side wall, 12b: Left side wall, 12f: Bottom of the storage compartment, 13, 13a, 13b: convex part, 14a: Right-side curved section, 14b: Left curved section, 15afh, 15b, 15e: Coolant supply groove, 17: Site where the cutting blade is provided, 17a: Site where the excision blade is provided, 17b: Site where the excision blade is provided, 18: Bottom line, 20: Female thread, 20a: Female threaded top.

Claims

[Claim 1] In a raising tap having a cutting blade that cuts off a portion of the female thread that may form a seam on the crest side of the female thread formed by threading due to plastic deformation of the pilot hole during the rotational operation after threading, With the peak (Ta) side of Togariyama facing upwards, With the valley floor (Tb) of Togariyama facing downwards, Let H be the height of the pointed mountain, which is the distance from the top of the pointed mountain (Ta) to the bottom of the valley (Tb) of the pointed mountain. The line connecting the peak (Ta) of the aforementioned pointed mountain and the valley floor (Tb) of the aforementioned pointed mountain is called the mountain line (K). Of the aforementioned Yamagata Line (K), the Yamagata Line located on the right side shall be referred to as the Right Yamagata Line (Ka). The mountain-shaped line (K) located on the opposite side of the right mountain-shaped line (Ka) is referred to as the left mountain-shaped line (Kb). A space for storing the removed portion is formed below the cutting position line (10) indicating the cutting position of the cutting blade, and a removed portion storage section (12) is provided, with the bottom of which is the bottom of the storage section (12f). The position of the aforementioned cutting line (10) is at H / 4 (the standard dimension of the standard mountain shape), The shape of the removal portion storage section (12) is such that the entire seam is located below the cut line (10), and the shape is one of the following (a) or (b): The diameter of the pilot hole into which the threads are threaded is such that the amount of plastic flow in the removed portion is such that the pilot hole diameter for achieving the seam position shape beyond the cut line is such that the removed portion is such that the tap threads the pilot hole diameter for achieving the seam position shape beyond the cut line. The removal portion storage section (12) is provided at a lower position away from the cutting position line (10), Between the excision position line (10) and the removal portion storage section (12), a female thread extension forming section (Q) is provided, which is formed on approximately the lines of the right-side V-shaped line (Ka) and the left-side V-shaped line (Kb), and which enables the formation of an extended female thread. The position in which the entire seam is located is a position less than the lowest position line (18) of the female thread extension forming portion (Q), which is a seam position shape that exceeds the cut position line. By forming the cutting blade (the position of the cutting line) at a small-diameter position (for example, a small-diameter cutting line (10a)) within the female thread extension forming portion (Q), it is possible to form female threads with a high engagement rate. A distinctive raised tap. (a) A form having a right-side space portion (+a) which extends to the right beyond the right-side curved line (Ka), and a form having a left-side space portion (+b) which extends to the left beyond the left-side curved line (Kb). (a) A form having a right-side space portion (+a) which is a space extending to the right beyond the right-side curved line (Ka), or a form having a left-side space portion (+b) which is a space extending to the left beyond the left-side curved line (Kb).

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