JP3037915U - Heap tap - Google Patents

Abstract

(57) [PROBLEMS] To provide a build-up tap with improved durability capable of suppressing the damage of the screw portion and uniformly supplying tapping oil to the screw portion. SOLUTION: On a threaded portion 2 provided on the tip side of a build-up tap 10, eight lobes 2c are formed at substantially equal intervals in the tap circumferential direction, and among these, two lobes adjacent to each other are formed substantially at the center. , The peak 12 of the second thread of the complete thread 12b
straight oil groove 12d extending from e to the tip side of the shank portion 3
Are formed. A total of four oil grooves 12d are arranged at equal intervals in the circumferential direction of the tap at an interval of approximately 90 °. By this oil groove 12d, tapping oil can be evenly supplied to the entire screw portion 2. Moreover, each oil groove 12d
Is not formed in the first peak of the bite part 2a and the complete threaded part 12b to which a large working resistance is applied during plastic working, so that the damage of the threaded part 2 due to the oil groove 12d can be suppressed. Therefore, the durability of the build-up tap 10 can be further improved.

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a build-up tap for forming a female screw on the surface of a prepared hole formed in a workpiece by plastic working. The present invention relates to a rising tap with excellent durability that can supply tapping oil evenly.

[0002]

2. Description of the Related Art A tap is known as a tool for forming an internal thread on a workpiece such as a metal plate or a metal block. This tap is equipped with a cutting edge to form a female screw while scraping the inner surface of the prepared hole in the workpiece, and a tap that does not have a cutting edge and plastically deforms the inner surface of the prepared hole to form a female thread. There is a raising tap to do. The cutting tap has many chips generated during processing and the finished surface becomes rough, whereas the raised tap does not generate chips during processing and the finished surface is smooth, so it has a blind hole. It is widely used in various fields, in addition to starting.

This build-up tap has a shank portion on the rear end side and a threaded portion on the front end side, and the threaded portion has a larger diameter on the front end side toward the rear end side in the axial direction of the tap. It has a tapered biting portion and a complete thread portion formed continuously on the rear end side of the biting portion. Since the build-up tap plastically deforms the material to be processed, the work resistance applied to the build-up tap is large and almost double that of the cutting tap. Therefore, when forming a female thread on a work piece using a build-up tap, wear on the thread itself due to contact with the work piece is reduced, and tapping is performed on the machined part to improve the durability of the build-up tap. It is preferable to positively inject oil to lubricate and cool the processed part. For this reason, some build-up taps have an oil groove as a tapping oil supply path formed in the threaded portion thereof. One or a plurality of these oil grooves are linearly formed from the tip side of the shank portion, that is, from the rear end of the complete screw portion to the tip of the bite portion.

[0004]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 40-1748 discloses a raising tap having one oil groove extending to a biting portion. This raised tap further has a through hole that penetrates from the tip of one oil groove to the opposite side of the tap shaft core. Not only the oil groove but also tapping oil is supplied from the through hole to the entire thread. Is what you are trying to do. However, since the oil supply route was complicated, such a rising tap was insufficient to evenly supply tapping oil in the circumferential direction of the tap.

On the other hand, if a plurality of oil grooves are formed in the screw portion, tapping oil can be evenly supplied in the circumferential direction of the tap. However, in particular, the first peak of the bite part and the complete thread part of the threaded part is the part where the prepared hole of the workpiece is plastically machined, and when machining the female thread, a very large machining resistance is generated. It is the part that joins. Therefore, if a lot of oil grooves are formed in the first peak of the bite part and the complete thread part, the part (the first peak of the bite part and the complete thread part) is likely to be damaged due to the oil groove. On the contrary, there was a problem that the durability of the heaping tap was impaired. Even if only one oil groove is formed on the threaded portion, the frequency will be less than when multiple oil grooves are formed, but due to the oil groove, the threaded portion will be formed. There is no change in the fact that there is a defect.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to suppress the damage of the threaded portion and supply tapping oil to the threaded portion evenly. Intended to provide a tap.

[0007]

[Means for Solving the Problems] In order to achieve this object, a raised tap according to a first aspect of the present invention is provided with a tapered bite portion provided on the tip end side of the tap and having a diameter increasing toward the rear end side in the axial direction. , A complete thread portion continuously formed on the rear end side of the bite portion, and a threaded portion having the bite portion and the complete threaded portion. A screw is formed, and the complete thread portion is composed of 2 to 3 threads, and the crest of the thread portion extends from the tip of the bite portion to the rear end of the complete thread portion. Are continuously formed.

The build-up tap according to claim 1 is forcibly fed so as to advance by one lead (one crest) by one rotation relative to the work piece, and plastically works the female thread. It is used by being attached to a device capable of such forced feeding. Therefore, even if the complete thread is composed of 3 threads or less, the tap can be neither advanced nor delayed, and the internal thread can be processed.

According to this build-up tap, firstly, the oil groove is not formed in the threaded portion, and the crests of the threaded portion continuously extend from the tip of the chamfered portion to the rear end of the completely threaded portion. Since it is formed, it is possible to prevent the thread portion from being damaged due to the oil groove. Secondly, although the oil groove is not formed in the threaded portion, the complete threaded portion is composed of three threads or less, so the tapping oil supplied from the shank portion side is evenly distributed over the threaded portion. Therefore, it is possible to suppress the damage of the threaded portion and to uniformly supply the tapping oil to the threaded portion, so that the durability of the build-up tap can be further improved. In addition, since the complete thread of the thread forming tap is composed of two or more threads, it is possible to measure the effective diameter using three screw measuring needles based on JIS.

According to another aspect of the present invention, there is provided a raised tap, which is provided with a tapered bite portion which is provided on a tip end side of the tap and has a diameter increasing toward an axial rear end side, and a rear end side of the bite portion. Of the complete thread, the threaded part having the bite part and the complete thread, a plurality of lobes formed on the threaded part, and a plurality of lobes that are adjacent to each other in the circumferential direction of the tap. An oil groove is formed in the axial direction at approximately the center between the two lobes, and a female thread is formed on the workpiece by plastic working with the threaded portion. The complete threaded portion has two or more threads and three threads. The oil groove is configured as follows, and the oil groove is formed from at least the second ridge on the front end side of the complete thread portion toward the tap rear end side.

[0012] The build-up tap according to claim 2 is also forcedly fed so as to advance one lead (one crest) by one rotation relative to the work piece, similarly to the build-up tap according to claim 1. Then, the female screw is subjected to plastic working, and is mounted and used in a device capable of such forced feeding. Therefore, even if the complete threaded portion is composed of three threads or less, it is possible to process the female thread without causing the tap to advance or delay.

According to this build-up tap, the oil groove is formed from at least the second ridge on the tip side of the complete threaded portion toward the tap rear end side, and the bite portion and the complete threaded portion to which a large machining resistance is applied during machining are formed. It is not formed on the first thread of the thread. For this reason, it is possible to prevent the thread portion from being damaged due to the oil groove, and since tapping oil can be supplied to the thread portion by the oil groove, it is possible to improve the durability of the build-up tap. is there. In addition, since the complete thread of the thread forming tap is composed of two or more threads, it is possible to measure the effective diameter using three screw measuring needles based on JIS.

According to a third aspect of the present invention, there is provided a build-up tap in which a taper-shaped bite portion provided on the tip end side of the tappet and having a diameter increasing toward the axially rear end side and a rear end side of the bite portion are continuous. Of the complete thread, the threaded part having the bite part and the complete thread, a plurality of lobes formed on the threaded part, and a plurality of lobes that are adjacent to each other in the circumferential direction of the tap. An oil groove is formed in the axial direction at approximately the center between the two lobes, and a female thread is formed on the workpiece by plastic working with the threaded portion, and the complete threaded portion has four or more threads. At the same time, the oil groove is formed from at least the second ridge on the tip side of the complete threaded portion toward the tap rear end side.

In the pile-up tap according to claim 3 of the present invention, unlike the pile-up tap according to claim 1 or 2, the complete threaded portion having four or more threads has a so-called self-propelling action. Therefore, it is a pile-up tap that can be used for devices that cannot move forward one lead (one mountain) at a time for one rotation. The first thread of the chamfered section and the complete thread section is formed in the pilot hole of the work piece, so the complete thread section consisting of four or more threads is screwed into the screw, and the build-up tap makes one lead per revolution ( Move forward one mountain at a time. That is, the rotation amount and the feed amount are synchronized by the four or more complete thread portions, and the internal thread can be processed without excessive or excessive tap delay.

According to this build-up tap, the oil groove is formed from at least the second ridge on the tip side of the complete threaded portion toward the tap rear end side, and the bite portion and the complete portion to which a large machining resistance is applied during machining are formed. It is not formed on the first thread of the thread. For this reason, it is possible to prevent the thread portion from being damaged due to the oil groove, and since tapping oil can be supplied to the thread portion by the oil groove, it is possible to improve the durability of the build-up tap. is there. Since the complete thread part of the thread forming tap is composed of 4 or more threads, it is naturally possible to measure the effective diameter using three screw measuring needles based on JIS.

The build-up tap according to claim 4 is the build-up tap according to claim 2 or 3, wherein a plurality of the oil grooves are formed at substantially equal intervals in the circumferential direction of the tap. Therefore, since tapping oil can be evenly supplied to the threaded portion more than when there is only one oil groove, the durability of the build-up tap can be further improved. Even if multiple oil grooves are provided, all oil grooves are formed from at least the second ridge on the tip side of the complete screw part toward the tap rear end side, which causes a large machining resistance during machining. Is not formed on the first ridge of the threaded portion and the complete threaded portion. Therefore, there is an effect that it is possible to suppress the damage of the screw portion due to the plurality of oil grooves.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a front view of the raising tap according to the first embodiment, which is an example of the raising tap according to claim 1.

The build-up tap 1 is provided with a threaded portion 2 on the front end side and a shank portion 3 on the rear end side. At the tip of the screw portion 2, a chamfered portion 2a for smoothly inserting the raised tap 1 into the prepared hole of the workpiece is formed in a tapered shape. The outer diameter of the taper of the bited portion 2a becomes larger as it goes from the front end side to the rear end side of the embossing tap 1 in the axial direction. Further, the threaded portion of the bited portion 2a is composed of three threads, and the complete threaded portion 2b is continuously formed at the rear end of the bited portion 2a. The complete screw portion 2b is composed of three threads, and it is possible to measure the effective diameter using three screw measuring needles based on JIS.

An oil groove for supplying tapping oil is not provided in the screw portion 2 composed of the bited portion 2a and the complete screw portion 2b, and therefore the crest of the screw portion 2 is It is formed continuously from the tip of the bited portion 2a to the rear end of the complete threaded portion 2b without being divided. Further, the screw portion 2 has eight lobes (protrusions) 2c formed at substantially equal intervals in the tap circumferential direction. The lobes 2c come into contact with the prepared hole of the workpiece and the build-up tap 1 is rotated, so that the internal thread is plastically machined in the prepared hole of the workpiece.

At the rear end of the screw portion 2, a shank portion 3 formed in a cylindrical shape having a diameter smaller than the outer diameter of the complete screw portion 2b is continuous, and at the rear end of the shank portion 3, a square pillar shape is formed. A shank square portion 4 that has been machined is formed. By mounting the shank square portion 4 on the head of a machine tool such as a tapping machine, the raising tap 1 is mounted on the machine tool such as a tapping machine.

The operation of the build-up tap 1 configured as described above will be described. First, the shank square portion 4 of the raised tap 1 is attached to the head of the tapping machine, and the workpiece with the prepared hole is set on the table of the tapping machine. Next, while rotating the head of the tapping machine, the raising tap 1 is fed in the axial direction, and the bite portion 2a of the screw portion 2 is inserted into the prepared hole of the workpiece installed on the table. Then, the lobe 2c provided on the screw thread 2b comes into contact with the inner wall of the prepared hole, whereby the inner wall of the prepared hole is plastically flowed, and the female screw is plastically worked on the workpiece. In addition, since the complete threaded portion 2b is composed of three ridges, this build-up tap 1 is unlikely to cause so-called self-propelling action. Therefore, the plastic working of such an internal thread is carried out by a machine tool by forcibly feeding the build-up tap 1 so as to advance one lead (one crest) by one rotation relative to the workpiece.

As described above, since the oil groove is not formed in the threaded portion 2 of the thread forming tap 1, the crest of the crest extends from the tip of the chamfered portion 2a to the rear end of the complete threaded portion 2b. It is formed continuously. Therefore, it is possible to prevent the thread portion 2 from being damaged due to the oil groove. Further, although the oil groove is not formed in the threaded portion 2, the complete threaded portion 2b has only three ridges, so the tapping oil that is supplied from the shank portion 3 side and fills the shank portion 3 immediately after the complete threaded portion 2b. Spreads over the threaded portion 2 evenly. In this way, it is possible to prevent the thread portion 2 from being damaged due to the oil groove, and moreover, since the tapping oil can be evenly distributed over the thread portion 2, the durability of the build-up tap 1 can be further improved.

Next, with reference to FIGS. 2 to 4, the raising tap of the second embodiment will be described. FIG. 2 is a front view of the raising tap of the second embodiment. Further, FIG. 3 is a view of the build-up tap in FIG. 2 viewed from the arrow III, and FIG. 4 is a cross-sectional view of the build-up tap in FIG. 2 taken along line IV-IV. The build-up tap 10 of the second embodiment is an embodiment of the build-up tap according to claims 2 and 4, and four oil grooves 2d are formed on the build-up tap 1 of the first embodiment. It was done. Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals, and only different parts will be described.

As shown in FIGS. 3 and 4, the threaded portion 2 of the raised tap 10 has eight lobes (protrusions) 2c formed at substantially equal intervals in the circumferential direction of the tap. These lobes 2c, 2c ... are used to plastically machine the female screw on the workpiece, and among the eight lobes 2c, approximately the center between the two lobes 2c, 2c adjacent to each other in the tap circumferential direction. An oil groove 12d is formed therein. Four oil grooves 12d are formed in total, and each oil groove 12d is formed at equal intervals in the tap circumferential direction at an interval of approximately 90 °. Thus, between the two adjacent lobes 2c, 2c, the oil grooves 12d are formed and the oil grooves 12d are not formed alternately. The oil groove 12d is formed in a straight line in the tap axis direction from the peak 12e of the second mountain of the complete screw portion 12b to the tip side of the shank portion 3. The tapping oil supplied from the shank portion 3 side during the plastic working is evenly supplied to the screw portion 2 by the oil groove 12d.

As described above, according to the raising tap 10 of the second embodiment, since the four oil grooves 12d are arranged at substantially equal intervals in the circumferential direction of the tap, the shank portion is formed during plastic working. The tapping oil supplied from the 3 side can be evenly supplied to the entire screw portion 2. Moreover, all of the four oil grooves 12d are formed from the peak 12e of the second ridge of the complete threaded portion 12b to the shank portion 3, and the chamfered portion 2a and the chamfered portion 2a to which a large working resistance is applied during plastic working Since it is not formed in the first crest of the complete threaded portion 12b, it is possible to suppress the loss of the threaded portion 2 due to the oil groove 12d. Therefore, the durability of the build-up tap 10 can be further improved.

In Japanese Utility Model Laid-Open No. 58-184226, a rolling portion and a cutting portion continuous to the rolling portion are provided, and a female screw is formed by plastic working by the rolling portion, and then the cutting is performed. It describes a tap that removes extra thickness generated on the inner diameter side of the screw due to plastic working by the cutting edge of the part. This tap has a groove from the tip of the cutting part to the shank part in order to form a cutting edge at the cutting part provided at the rear end of the rolling part. However, this groove is only a groove for forming a cutting edge, and both sides of the groove are cutting edges and are plastically worked so as to come into contact with the inner diameter of the screw. On the other hand, the oil groove 12d of the present embodiment is a groove for supplying tapping oil to the threaded portion 2 and is provided substantially in the center between the two adjacent lobes 2c, 2c. Since both sides of the oil groove 2c are plastically worked, they do not come into contact with the inner diameter of the screw. As described above, the raising tap 10 according to the second embodiment is completely different in purpose and configuration from the tap described in Japanese Utility Model Laid-Open No. 184226/1983.

Finally, with reference to FIG. 5, the raising tap of the third embodiment will be described. FIG. 5 is a front view of the raising tap of the third embodiment. The build-up tap 20 of the third embodiment is an embodiment of the build-up tap according to claims 3 and 4, and the number of peaks of the complete screw portion 12b of the build-up tap 20 of the second embodiment is three. It was changed from 14 mountains to 14 mountains. Hereinafter, the same parts as those in the first and second embodiments are designated by the same reference numerals, and only different parts will be described.

As shown in FIG. 5, the complete threaded portion 22b of the build-up tap 20 has 14 threads. For this reason, the build-up tap 20 has a so-called self-propelled action, and unlike the build-up taps 1 and 10 of the first and second embodiments, it can be used for a machine tool in which the feed amount and the rotation amount are not synchronized. it can. An oil groove 22d is formed in the complete threaded portion 22b at approximately the center between the two lobes 2c, 2c of the eight robes 2c that are adjacent to each other in the tap circumferential direction. Four oil grooves 22d are formed in total, and each oil groove 22d is formed at equal intervals in the tap circumferential direction at intervals of about 90 °. Therefore, between the two adjacent lobes 2c, 2c, the oil groove 22d and the oil groove 22d are alternately arranged. The oil groove 22d is linearly formed in the tap axis direction from the peak 22e of the second ridge of the complete threaded portion 22b to the tip side of the shank portion 3. During the plastic working, the tapping oil supplied from the shank portion 3 side is evenly supplied to the screw portion 2 by the oil groove 22d.

As described above, according to the pile-up tap 20 of the third embodiment, the four oil grooves 22d are arranged at substantially equal intervals in the circumferential direction of the tap, so that the shank portion is formed during plastic working. The tapping oil supplied from the 3 side can be evenly supplied to the entire screw portion 2. Moreover, each of the four oil grooves 22d is formed from the peak 22e of the second ridge of the complete threaded portion 22b to the shank portion 3, and the chamfered portion 2a and the chamfered portion 2a to which a large machining resistance is applied during plastic working Since it is not formed in the first crest of the complete threaded portion 22b, it is possible to suppress the loss of the threaded portion 2 due to the oil groove 22d. Therefore, the durability of the build-up tap 20 can be further improved.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Is easily guessed.

For example, in the second and third embodiments, the oil grooves 12d and 22d are both formed linearly in the tap axis direction, but they may be formed spirally. The number of oil grooves 12d and 22d is not limited to four, and may be one to three, or five or more. For example, a total of eight oil grooves may be provided, one for each of the eight lobes 2c, 2c adjacent to each other in the tap circumferential direction. By providing many oil grooves for the material that is difficult to plastically deform, plastic working is efficient, and conversely, for the material that is easily plastically deformed, reducing the oil grooves results in efficient plastic working. Therefore, the number of oil grooves formed in the tap is appropriately selected according to the work material. Further, the oil grooves 12d and 22d are formed from the second crests 12e and 22e of the complete threaded portions 12b and 22b toward the shank portion 3 side. However, the oil grooves 12d and 22d may be formed anywhere as long as they are at the bottoms of the first and second peaks of the complete threaded portions 12b and 22b.

[Brief description of the drawings]

FIG. 1 is a front view of a raising tap which is a first embodiment of the present invention.

FIG. 2 is a front view of a raising tap according to a second embodiment.

[Fig. 3] I in Fig. 2 of the raising tap of the second embodiment.
It is an II arrow line view.

[Fig. 4] Fig. 4 shows an I of Fig. 2 of the raising tap of the second embodiment.
It is a V-IV sectional view taken on the line.

FIG. 5 is a front view of a raising tap according to a third embodiment.

[Explanation of symbols]

 1,10,20 Raised tap 2 Screw part 2a Corroded part 2b, 12b, 22b Complete screw part 2c Lobe (protruding part) 12d, 22d Oil groove 3 Shank part 4 Shank square part

Claims (4)

[Utility model registration claims] 1. A tapered bite portion provided on the tip end side of the tap and having a diameter increasing toward the rear end side in the axial direction, and a complete threaded portion continuously formed on the rear end side of the bite portion. And a threaded portion having a chamfered portion and a complete threaded portion, wherein the threaded portion is formed by forming a female thread on a workpiece by plastic working, the complete threaded portion having two or more threads and three or less threads. In addition, the crest of the thread portion is formed continuously from the tip of the bite portion to the rear end of the complete screw portion. 2. A tapered bite portion provided on the tip end side of the tap and having a diameter increasing toward the rear end side in the axial direction, and a complete threaded portion continuously formed on the rear end side of the bite portion. A threaded portion including the bite portion and the complete threaded portion, a plurality of lobes formed in the threaded portion, and an axial direction at an approximate center between two lobes adjacent to each other in the tap circumferential direction of the plurality of lobes. In the build-up tap, which comprises an oil groove formed in, and which forms a female thread on a workpiece by plastic working with the threaded portion, the complete threaded portion is configured with two or more threads and three or less threads, and the oil groove is The raised tap is formed from at least the second ridge on the tip side of the complete threaded portion toward the tap rear end side. 3. A tapered bite portion provided on the tip end side of the tap and having a diameter increasing toward the rear end side in the axial direction, and a complete threaded portion formed continuously on the rear end side of the bite portion. A threaded portion including the bite portion and the complete threaded portion, a plurality of lobes formed in the threaded portion, and an axial direction at an approximate center between two lobes adjacent to each other in the tap circumferential direction of the plurality of lobes. In a build-up tap having an oil groove formed in, and forming a female screw on a workpiece by plastic working with the threaded portion, the complete threaded portion is configured with four or more threads, and the oil groove is A raised tap that is formed from at least the second ridge on the tip side of the complete threaded portion toward the rear end side of the tap. 4. The plurality of oil grooves are formed at substantially equal intervals in the circumferential direction of the tap.
Or the heap tap described in 3.