JPH07276139A - Tap for tapping - Google Patents

Abstract

PURPOSE:To improve surface roughness of a completed screw thread surface, precision of a screw thread and strength of the screw thread surface by work hardening by applying rolling machining to the screw thread after cutting machining by a rolling blade part after carrying out cutting rough finish machining of tapping on a complete cutting blade part formed continuously on a chamfer on the head end. CONSTITUTION:This is a tap for tapping on which a complete cutting blade part 11 formed continuously on a tapered chamfer 11b and a rolling blade part 11t of a screw type of the same lead as the complete cutting blade part to carry out only rolling machining without carrying out cutting machining continuously on the complete cutting blade part are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tap for tapping, and more particularly to a rolling blade after a rough cutting finish for tapping is performed by a complete cutting edge formed continuously at a biting portion at the tip. An epoch-making that improves rolling surface roughness of the finished thread surface, improves thread accuracy, and improves strength by work hardening of the thread surface by applying rolling processing to the thread after cutting Related to taps for tapping.

[0002]

2. Description of the Related Art Referring to FIG. 8, a tapping tap 1 that has been generally used in the past has a bite portion 1b at a tip 1a.
A continuous cutting edge portion 1c is formed continuously, vertical grooves 1d are formed at four positions in the circumferential direction, and a cutting edge 1f is formed at the rotational direction tip portion 1e of the vertical groove 1d. A shank portion 1g and a square portion 1h are formed behind the portion 1c.

However, when the projection 2a formed by subjecting the thin plate 2 as shown in FIG. 9 to burring by the tapping tap 1 of the conventional example is tapped, the tapping tap 1 is completely cut off. Since it is composed of a blade, the protruding portion 2a of the machined thin plate 2 is scraped off by the height of the screw thread 2c at all parts from the inside to the outside thereof, so that the remaining protruding portion 2a remains. The wall thickness of the wall portion 2b becomes very thin, the strength of the screw thread 2c is impaired, and in some cases, tapping itself may be impossible.

Further, as a result of cutting work being performed on all parts, there is a drawback that the surface roughness of the screw thread 2c becomes rough and the accuracy of the screw thread is not good.

Further, as shown in FIGS. 10 and 11, a tapping tap 3 having only a rolling blade portion 3a having no vertical groove has been put into practical use.
In, the surface roughness of the processed screw thread is good, and although the effect of improving the strength of the screw thread by work hardening of the screw thread surface can be obtained, since tapping processing of all parts is performed by rolling, If the work piece is very hard, tapping is impossible, and with gas screws, there is a drawback that it cannot be used because the wall thickness of the pipe is thin.

[0006] In addition, "Screw creation tool" is included in the actual exploitation sho 63-86929, and "Tap" is included in the actual fair 4-17303.
However, the actual tapping 4-122418 has a "tap with a reamer" and the actual tapping 3-1-1522 has a "bending prevention guide for a tap for tapping, a die and a reamer for hole finishing".
However, each of these inventions is completely different in structure from the present invention, and the same drawbacks as those of the conventional example cannot be solved.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art. The object of the present invention is to form a taper-like biting portion continuously. A composite cutting in which a complete cutting edge portion and a threaded rolling edge portion with the same lead as the complete cutting edge portion are formed so that only the rolling operation is performed without performing cutting processing continuously to the complete cutting edge portion By using a tap for tapping the blade, first, the biting portion and the complete cutting edge portion are tapped as rough finish by cutting, and then the thread surface formed by cutting with the rolling blade portion. In order to improve the surface roughness of the screw thread, the accuracy of the screw thread, and the strength of the screw thread, a rolling process is applied to the screw thread to give work hardening to the screw thread surface.

Another object is to provide a complete cutting edge portion having a vertical groove formed continuously on a tapered bite portion, and to perform only rolling without continuous cutting operation on the complete cutting edge portion. By forming a thread-shaped rolling blade that has the same lead as the complete cutting edge and does not have a vertical groove as is done, it is possible to perform tapping even on a very hard workpiece, and When tapping a protruding portion obtained by burring a thin plate, it is possible to prevent thickness loss by pushing the meat from the inside toward the outside during tapping, and even if the protruding portion is thin. That is, it is possible to perform tapping while leaving a sufficient wall thickness, and to enable tapping even for an extremely thin work piece such as a gas pipe.

Still another object is to form a complete cutting edge portion continuously formed on a tapered biting portion and to perform only rolling without continuous cutting operation on the complete cutting edge portion. By forming a rolling blade part which is the same lead as the complete cutting blade part and in which the cutting edge at the tip in the rotational direction is cut off, and by continuously forming a vertical groove from the biting part to the rolling blade part. , The effect of increasing the surface roughness by rolling, the effect of improving thread strength by work hardening, and the effect of improving accuracy, while applying the force to spread the threads from inside to outside during rolling. This is to reduce the number of screws and to enable sufficient tapping even for a thin work piece.

[0010]

SUMMARY OF THE INVENTION In summary, the present invention (Claim 1) is such that a complete cutting edge portion formed continuously with a tapered bite portion and a cutting operation continuous with the complete cutting edge portion. It is characterized in that the complete cutting edge portion and the thread-shaped rolling edge portion having the same lead are formed so that only the rolling operation is performed.

According to the present invention (claim 2), a complete cutting edge portion having a vertical groove is formed continuously to the tapered biting portion,
A thread-shaped rolling blade portion having the same lead as that of the complete cutting edge portion and having no longitudinal groove is formed so that only the rolling operation is performed continuously without cutting the complete cutting edge portion. It is characterized by that.

Further, according to the present invention (claim 3), a complete cutting edge portion continuously formed on the tapered biting portion and a rolling operation only without performing a cutting operation continuously on the complete cutting edge portion To form a rolling blade part which is the same lead as the complete cutting blade part and in which the cutting blade at the tip of the rotating direction is cut off, and the vertical groove is continuous from the biting part to the rolling blade part. It is characterized by being formed by.

[0013]

The tapping tap according to the present invention is a compound tapping tap in which a rolling edge is formed subsequent to the complete cutting edge. After that, tapping can be performed by rolling with the rolling blade portion.

Therefore, as compared with the case where the tapping is performed by cutting to the end, the surface roughness of the screw thread can be improved, and the work hardening by rolling improves the strength and accuracy of the screw thread surface. Moreover, even a very thin work piece has a small thickness loss, so that tapping can be sufficiently performed.

[0015]

1 to 3, the first embodiment of the present invention will be described. The tapping tap 11 according to the present invention is formed continuously with the tapered bite portion 11a of the tip 11a. Complete cutting edge portion 11c having a vertical groove 11d
And a thread-shaped rolling blade portion 11t having the same lead as the complete cutting blade portion 11c and having no longitudinal groove 11d so that only the rolling processing is performed without cutting the continuous cutting blade portion. It is a compound tap formed with the
The shank portion 11g and the square portion 11h are continuously formed in 1t.

Further, as shown in the figure, the diameter of the rolled cutting edge 11t is set to be slightly larger than the diameter of the complete cutting edge 11c.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 to 7. The tapping tap 21 according to the present invention is formed continuously with the tapered bite portion 21b of the tip 21a. Complete cutting edge portion 21c and the complete cutting edge portion 2
Rolling blade portion 21 having the same lead as the complete cutting blade portion 21c and the cutting edge 21f of the tip portion 21e in the rotational direction being cut off so as to perform only rolling processing without performing cutting processing continuously to 1c
t is formed, and the biting portion 21b to the rolled blade portion 21t
The vertical groove 21d is a composite tap continuously formed, and the shank portion 21g is continuous with the rolling blade portion 21t.
And a square portion 21h is formed.

Further, as shown in the figure, the diameter of the rolled blade portion 21t is set to be slightly larger than the diameter of the complete cutting edge portion 21c.

As shown in FIG. 6, the cutting edge 21f may be cut off at the tip 21j on the side opposite to the rotating direction, but it is not always necessary to cut off the tip 21j on the opposite side.

The present invention is configured as described above,
The operation will be described below. First, the operation of the tapping tap 11 according to the first embodiment will be described with reference to FIGS. 1 to 4. When the thin plate 2 shown in FIG. 4 is subjected to burring and the protruding portion 2a is tapped, A fixing ring 4 having a hole 4a having the same shape as that of the protrusion 2a is inserted into the protrusion 2a so that the protrusion does not spread during tapping around the portion 2a.

Therefore, when the tapping tap 11 is inserted while being rotated from above the thin plate 2, first the biting portion 1
The tapping process is started by 1b, and subsequently the tapping as rough finish is performed by the cutting process by the complete cutting edge portion 11c. At this stage, the surface roughness of the screw thread 2c is still considerably rough, and since the surface of the screw thread 2a has not been work hardened, the strength and accuracy are not improved.

When the tapping tap 11 is further lowered,
Since the rolling cutting edge portion 11t applies rolling processing to the thread 2c that has completed tapping as rough finish, the surface of the thread 2c is thinned from the inner side to the outer side by rolling at this stage. Since the threads 2c are formed as the meat of No. 2 is spread out, even if the protrusion 2a is thin, the residual meat 2b is not shaved much, and the threads 2c are formed by the material that moves from the inside to the outside. Is formed, it is possible to leave sufficient residual meat 2b.

Further, the rolling process causes work hardening on the surface of the screw thread 2c, the strength of the screw thread 2c is increased, the surface roughness is reduced, and the accuracy of the screw thread 2c is improved.

In this way, even if the considerable thin plate 2 is subjected to the burring process, the tapping process can be performed with a margin, and the quality of the completed screw thread 2c is very good, and the strength of the residual thickness 2b is high. Can also be kept large.

Further, even with a very hard material, since the tapping by the cutting process is first performed by the complete cutting edge portion 11c, the tapping can be sufficiently performed.

Next, the operation of the tapping tap 21 according to the second embodiment of the present invention will be described with reference to FIGS. 5 to 7. In this embodiment, the vertical groove 21d has the bite portion 21b,
Since it is formed over the complete cutting edge portion 21c and the rolling edge portion 21t, at the time of rolling at the rolling edge portion 21t, the force to expand from the inner side to the outer side is smaller than that in the first embodiment. Therefore, it is not always necessary to use the fixing ring 4, and tapping is started from the bite portion 21b, followed by tapping as rough finishing by the complete cutting edge portion 21c, and further rolling by the rolling blade portion 21t. The machining is added to the thread 2c completed in advance (see FIG. 4) to improve the surface roughness, the strength by work hardening and the accuracy of the thread 2c.

In this case, unlike the first embodiment, the rolling process is performed with the vertical groove 21d formed, so that the reaction force from the material associated with the process is small and the chip discharge is good. To be done.

[0028]

As described above, according to the present invention, a complete cutting edge portion is formed continuously on the tapered biting portion as described above, and only the rolling operation is performed without continuously cutting the complete cutting edge portion. As it is a tap for compound cutting edge with a complete cutting edge and a threaded rolling edge with the same lead, it is necessary to cut the chamfered part and the complete cutting edge first. Roughing is performed by tapping, and then the thread surface formed by cutting is rolled by the rolling blade to give work hardening to the thread surface. Is improved, the accuracy of the thread is improved, and the strength of the thread is improved.

Further, a complete cutting edge portion having a vertical groove formed continuously on the tapered bite portion, and a complete cutting operation which is continuous with the complete cutting edge portion without performing a cutting operation Since a thread-shaped rolling blade with the same lead as the blade and no vertical groove is formed, tapping can be performed even on extremely hard workpieces, and thin plates can be burred. In the tapping of the obtained protrusion, the meat is pushed from the inside toward the outside during tapping, so it is possible to prevent loss of wall thickness, and even if the protrusion is thin, leave the screw with sufficient wall thickness. In addition to the effect of being able to stand up, there is an effect that even an object having a very thin wall thickness such as a gas pipe can be tapped.

Furthermore, a complete cutting edge portion formed continuously on the tapered biting portion and a complete cutting edge which is continuous with the complete cutting edge portion and is subjected to only rolling without cutting. And a rolling blade part which is the same lead as the cutting part and in which the cutting edge at the tip in the direction of rotation is cut, and a vertical groove is continuously formed from the biting part to the rolling blade part. While reducing the surface roughness by rolling, the effect of improving the screw thread strength by work hardening, and the effect of improving accuracy, the force to expand the screw thread from the inside to the outside during rolling processing is reduced. The effect that sufficient tapping can be performed even on a thin workpiece is obtained.

[Brief description of drawings]

1 to 4 relate to a first embodiment of the present invention, and FIG. 1 is a perspective view of a tap for tapping.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG.

FIG. 3 is a lateral cross-sectional view taken along the line III-III of FIG.

FIG. 4 is a vertical cross-sectional view showing a mutual relationship between a thin plate on which tapping has been completed and a fixing ring.

5 to 7 relate to a second embodiment of the present invention, and FIG. 5 is a perspective view of a tap for tapping.

6 is a horizontal cross-sectional view taken along the line VI-VI of FIG.

7 is a transverse cross sectional view taken along the line VII-VII in FIG.

8 to 11 relate to a conventional example, and FIG. 8 is a perspective view of a tap for tapping.

FIG. 9 is a vertical cross-sectional view of a thin plate on which tapping has been completed.

FIG. 10 is a perspective view of a tap for tapping.

11 is a lateral cross-sectional view taken along the line XI-XI of FIG.

[Explanation of symbols]

 11 Tap for tapping 11b Bited part 11c Complete cutting edge part 11d Vertical groove 11t Rolled cutting edge part 21 Tapping tap 21b Bited part 21c Complete cutting edge part 21d Vertical groove 21e Tip part 21f Cutting edge

Claims (3)

[Claims] 1. A complete cutting edge portion continuously formed on a tapered bite portion, and the complete cutting edge so that only the rolling operation is performed without cutting the continuous cutting edge portion continuously. A tap for tapping, characterized in that a thread-shaped rolling blade part having the same lead as that of the part is formed. 2. A complete cutting edge portion which is formed continuously with a tapered bite portion and has a longitudinal groove, and a rolling operation which is continuous with the complete cutting edge portion without performing cutting work. A tap for tapping, characterized in that a thread-shaped rolling blade portion having the same lead as the complete cutting blade portion and not having the vertical groove is formed. 3. A complete cutting edge portion formed continuously with a tapered bite portion, and the complete cutting edge so that only the rolling operation is performed without cutting the continuous cutting edge portion. And a rolling blade part which is the same lead as that of the cutting part and in which the cutting edge at the tip end in the rotational direction is removed, and a vertical groove is continuously formed from the biting part to the rolling blade part. Tap for tapping.