JP4176930B2 - Pipe threading tools - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to root Ji cutting tools for tube.
[0002]
[Prior art]
FIGS. 8A and 8B are diagrams showing a conventional typical thread cutting tool and thread cutting method.
(A): A drill 102 is set on the machine tool 101, and a screw pilot hole 104 is machined on the work 103 with the drill 102.
(B): When the machining of the screw pilot hole 104 is completed, the machine tool 101 is temporarily stopped, the tool is replaced with a tap 105, and the pipe parallel female screw 106 is cut with the tap 105. This completes the processing of the pipe parallel female thread 106. The tap 105 is a typical thread cutting tool, and is a pipe parallel thread tap (JIS B 4446).
[0003]
[Problems to be solved by the invention]
When the pipe parallel female screw 106 is cut with the tap 105, the accuracy is improved by setting the rotation speed of the tap 105 to a low value. If the rotational speed is lowered to increase accuracy, the processing time becomes longer and the productivity cannot be increased. As a result, generally high productivity cannot be expected in the processing of parallel female threads for pipes. However, low productivity cannot be neglected due to recent demands for reducing production costs.
[0004]
It is therefore an object of the present invention is to provide a root for good tube Ji cutting tools production efficiency.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, the shank has an end portion having a chevron shape for alignment with the tip, and the tip comprises a second hard sintered body of CBN or diamond. A three-layer laminate in which the second layer is sandwiched between a first layer and a third layer made of a tool material such as cemented carbide is used as a chip. When the chip is viewed from the front, the second layer is a tool. A V-shaped adhesive portion that is bonded to the end of the shank with an adhesive so as to form a thin band passing through the center of rotation, and a cutting blade that is formed only on the second layer. a bottom blade provided finely resulting chips are, connected to the end cutting edge, and threading the blade of the cross-section V of processing the valley of the internal thread, both the skirt of threading edge, so as adjust the shape of the crest of the internal thread a pair of shaping blade portions which are formed, characterized in that it comprises.
[0006]
Thereby forming a threading edge machining valley roots Ji internal thread for pipe applications, since a pair of shaping blade unit for processing the top of the internal thread of the mountains on both foot of the threading edge, a Ji roots Pipe Can be processed. In addition, since the tip is made of a high hardness sintered body of CBN or diamond, the cutting speed can be greatly increased. As a result, it is possible to process the Ji root for the tube in a short period of time.
According to a second aspect of the present invention, the thread cutting blade is for processing a trough of a female thread of a pipe parallel thread. As a result, a parallel pipe thread can be processed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
Figure 1 is a side view of a tube for root Ji cutting tool according to the present invention, roots Ji cutting tool 10 for pipe, parallel threaded tool tube (hereinafter, referred to as parallel threading tool 10 for pipe), the shank 11 The tip 13 is fixed to the end with a filter 12.
The shank 11 is made of a cemented carbide round bar having a predetermined outer diameter, an oil hole is formed, and a tip is formed in a mountain shape. By making the tip a chevron, it is possible to improve the alignment accuracy of the chip 13 and improve the adhesive strength.
[0008]
FIG. 2 is an enlarged view of part 2 of FIG. 1 and shows that the cutting edge 16 is formed on the chip 13.
The cutting blade 16 is composed of a bottom blade 21, a thread cutting blade 22, and a countersink blade 23, and these blades are continuous blades. Specifically, the bottom blade 21 forms a first bottom blade 24 at the tip, forms a second bottom blade 25 from the first bottom blade 24 toward the shank, and then extends from the second bottom blade 25 to the shank. A third bottom blade 26 is formed in the direction toward the shank, a thread cutting blade 22 is formed continuously toward the shank, and a countersink blade 23 is formed continuously toward the shank toward the shank. Is. Details of the thread cutting blade 22 will be described with reference to FIG. Reference numeral 27 denotes a rake face, and 28... (... indicates a plurality. The same applies hereinafter) is a flank face. θ is the tip angle of the cutting edge 16 and is 180 °.
In addition,
[0009]
FIG. 3 is a view taken in the direction of arrow 3 in FIG. 2, and the tip 13 has a high hardness sintered body of CBN or diamond as the second layer 31, and the second layer 31 is a first made of a tool material such as cemented carbide. When the chip 13 is viewed from the front, the second layer 31 is a vertically long thin band passing through the center of rotation of the tool. And both sides of the second layer 31 are reinforced by the first layer 32 and the third layer 33. For example, the thickness of each of the three-layer stacks is about 1 mm for the second layer 31, about 5 mm for the first layer 32 and the third layer 33, and about 11 mm for the entire thickness. 35 and 35 are oil holes, and 36 and 36 are chip discharge grooves.
[0010]
FIG. 4 is a perspective view showing the shape of a chip according to the present invention. A three-layer laminate in which first, second, and third layers 32, 31, and 33 are laminated is a chip 13, and a thin band of the second layer 31 is shown. The first bottom blades 24, 24, the second bottom blades 25, 25, and the third bottom are step portions for forming the cutting blades 16, 16 on the cutting edges 16 and 16 and generating fine chips on the cutting blades 16, 16. The blades 26 and 26 are formed, the thread cutting blades 22 and 22 for cutting a screw are formed, and the blades 23 and 23 having the same diameter as the inner diameter of the female screw are formed. 38 ... is a front flank.
[0011]
FIG. 5 is an enlarged view of part 5 of FIG.
The thread cutting edge 22 has a rounded portion 42 for machining a trough of a parallel female thread for a pipe on a crest 41 of a cross section V, and a pair of shaping blade sections for adjusting the shape of a crest of a parallel female thread for a pipe on hems 43 and 43 of a cross section V 44, 45. r1... is the radius, HT is the blade height, and β is the blade angle of the cross section V. For example, when the nominal diameter of the screw is PS3 / 8 (not in JIS B 0203 ISO standard), the radius r1 is 0.18 mm, the blade height HT is 0.856 mm (equal to the thread height), the blade The angle β is 55 ° (equal to the thread angle).
[0012]
Next, the operation of the pipe parallel threading tool described above will be described.
FIGS. 6A to 6C are first operational views of the parallel thread cutting tool for pipes according to the present invention.
In (a), the pipe parallel thread cutting tool 10 is faced to the casting 51, and chamfering is started first.
[0013]
In (b), the pipe parallel threading tool 10 is turned into an arc while the pipe parallel threading tool 10 is rotated by rotating the pipe parallel threading tool 10 itself (arrow (1)) by offsetting the shaft 53 of the pipe parallel threading tool by the distance δ1 with respect to the threaded hole shaft 52. Contouring processing is carried out (arrow 2). Since the bottom blade 21 and the thread cutting blade 22 are formed, the chamfered portion 54 can be formed in advance.
[0014]
In (c), the thread cutting blade 22 is fed, and the casting 51 is passed through the casting 51 as indicated by the phantom line. By forming the thread cutting edge 22, the screw prepared hole 55 can be processed. The screw hole diameter D1 of the screw hole 55 is substantially equal to the outer diameter of the thread cutting blade 22.
[0015]
FIGS. 7A to 7C are second operation views of the parallel thread cutting tool for pipes according to the present invention, and FIG. 7B is an enlarged view of a portion b of FIG.
In (a), after passing through the screw pilot hole 55, the shaft 53 of the pipe parallel threading tool is offset by a distance δ2 from the screw hole shaft 52, and while rotating the pipe parallel threading tool 10 itself, The parallel thread cutting tool 10 for pipes is sent to a circular arc at the center (arrow ▲ 3 ▼), and the contouring process is performed. At the same time this feed finishes one round, the feed of only the pitch P (arrow ▲ 4 ▼) is also finished. The parallel female thread 56 for pipes can be cut with the thread cutting blade 22 by feeding in a spiral (helical processing) and gradually pulling out the parallel thread cutting tool 10 for pipes.
[0016]
In (b), the trough 57 having the radius r1 can be formed by forming the rounded portion 42 at the crest 41 of the cross section V where the trough 57 of the pipe parallel female screw 56 is processed in the tip 13.
Further, by forming a pair of shaping blade portions 44 and 45 for adjusting the shape of the crests 58 and 58 of the pipe parallel female screw 56 at the hems 43 and 43 of the cross section V, a crest 58 having a radius r1 is formed. be able to.
[0017]
Further, since the pair of shaping blade portions 44, 45 are formed on the skirts 43, 43 of the cross section V, the portion left uncut by the shaping blade portion 44 on the side of the sweeping blade 23 at the time of the contouring process and the helical machining is represented by an imaginary line. It can cut with the shaping blade part 45 shown by and can complete the peak 58 of a mountain. By repeating this operation (NC machining), a predetermined number of threads can be secured in the end, and the pitch P (1.3368 mm for PS3 / 8), female thread root diameter D2, female thread The internal female thread 56 for the pipe having an inner diameter D3 and an effective diameter D4 (15806 mm in the case of PS3 / 8) can be processed.
In this way, since the blade capable of processing the pipe parallel female thread 56 is formed on a chip of a high hardness sintered body of CBN or diamond, high-speed cutting can be performed, and the production efficiency of the pipe parallel female thread can be improved. Improvements can be made.
[0018]
In addition, the pipe parallel thread cutting tool can cut a plurality of pipe parallel threads with a single thread as long as the threads (pitch, peak height, radius r1) are the same. That is, other dimensions such as the effective diameter D4 can be processed by changing the NC program. For example, both PT1 / 4 and PT3 / 8 can be processed with one parallel threading tool for pipes. Therefore, the cost of the thread cutting tool can be reduced.
[0019]
In (c), the pipe parallel threading tool 10 is removed, and the threading of the pipe parallel female thread 56 is completed.
[0020]
The bottom blade 21 of FIG. 4 shown in the embodiment of the present invention is a blade in which the first, second and third bottom blades 24, 25 and 26 are formed in a step shape, but the blade is limited to a step shape. Not what you want.
[0021]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
In claim 1, the shank is provided with an end portion having a chevron shape for alignment with the tip , and the tip is a three-layer laminate, and when viewed from the front, the second layer is the center of rotation of the tool. A V-shaped adhesive portion bonded to the end of the shank with an adhesive so as to form a thin band passing through the blade, and a cutting blade formed only on the second layer, the cutting blade being provided at the tip a bottom blade finely generating chips, connected to the end cutting edge, and threading the blade of the cross-section V of processing the valley of the internal thread, both the skirt of threading edge, is formed to adjust the shape of the crest of the internal thread since comprises a pair of shaping blade portion, a finely produce chips at the bottom edge of the chip, after processing the prepared hole, followed, chips contouring function, and controlled by helical functions, by threading the blade it is possible to process the Ji root for the tube. At this time, since the chip was high-hardness sintered body of CBN or diamond, roots Ji cutting tool tubes can set the processing conditions of the high speed cutting, it is possible to reduce the processing time.
Therefore, it is possible to improve the Ji of production efficiency root for the tube.
In addition, the shank has an end portion formed in a chevron shape for alignment with the chip, and the chip has a V-shaped adhesive portion bonded to the end portion. The accuracy can be improved and the adhesive strength can be improved.
According to the second aspect of the present invention, since the thread cutting blade processes the valley of the female thread of the pipe parallel thread, the pipe parallel thread can be processed. Accordingly, it is possible to improve the production efficiency of the pipe parallel female thread.
[Brief description of the drawings]
Side view of the root Pipe Ji cutting tool according to the invention, FIG 2 shows two-part enlarged view of FIG. 1 FIG. 3 the shape of the tip of the 3 arrow view of FIG. 2 and FIG. 4 of the present invention FIG. 5 is an enlarged view of part 5 in FIG. 2. FIG. 6 is a first action diagram of the parallel thread cutting tool for pipes according to the present invention. FIG. 7 is a second action diagram of the parallel thread cutting tool for pipes according to the present invention. FIG. 8 is a diagram showing a typical typical thread cutting tool and thread cutting method.
10 ... root Ji cutting tool pipe, 11 ... shank, 13 ... chips, 16 ... cutting blade, 22 ... threading edge, 31 ... second layer, 32 ... first layer, 33 ... third layer of 41 ... cross-section V Summit, 42 ... Earl part, 43 ... Hem of thread cutting blade, 44, 45 ... Shaping blade part, 56 ... Parallel female thread for pipe, 57 ... Valley of female thread, 58 ... Summit of female thread.

Claims (2)

A pipe threading tool comprising a chip for machining a female thread and a shank for mounting the chip,
The shank includes an end portion formed in a chevron for alignment with the tip,
The chip high hardness sintered body of CBN or diamond and the second layer, the second layer 3 layer laminate is sandwiched by the first and third layers made of tool materials, such as cemented carbide, front Viewed from a second layer is bonded portion of the V-shape being glued to the end portion of the shank such that the narrow band passing through the center of rotation of the tool, is formed only in the second layer A cutting blade,
The cutting edge, a bottom edge to finely generate chips provided at the tip, connected to said bottom edge, and threading the blade of the cross-section V of processing the valley of the internal thread, both the skirt of the threading edge, the internal thread root Ji cutting tool tubes characterized by comprising a pair of shaping blade portions formed to adjust the shape of the top of the mountain. 2. The thread cutting tool for a pipe according to claim 1, wherein the thread cutting edge is for processing a valley of a female thread of a parallel thread for a pipe.

Images