Tap for pipe and tip used for tap for pipe

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a thread cutting tool and a tip used in the thread cutting tool.

【0002】

[Conventional technology]

Generally, in the Oster type chaser, as shown in FIGS. 4A, 4B, and 4C, the body 100 is formed in a rectangular parallelepiped shape, and the cam groove 102 is recessed in the upper surface 101 of the body 100. , A cutting edge 103 having a predetermined thread shape is formed on one end side of the body 100 by cutting or grinding. When threading a pipe screw into a steel pipe such as a gas steel pipe or a water pipe, a plurality of Oster type chasers are mounted in the mounting groove of the die head so as to radiate with respect to the steel pipe. Then, by driving the motor or the like, the cutting edge 103 of the chaser mounted on the die head and the steel pipe are relatively rotated and relatively moved in the axial direction of the steel pipe, whereby a pipe screw is formed on the steel pipe.

【0003】

[Problems to be Solved by the Invention]

However, in this Oster type chaser, the cutting edge 103 is integrally formed with the main body 100. Therefore, if the cutting edge 103 is to be made of high-speed steel in order to thread a difficult-to-cut material such as stainless steel, not only the cutting edge 103 but also the main body 100 must be made of high-speed steel, which is costly. There was a problem that it would increase. In addition, when the cutting edge 103 is worn or damaged, if the cutting edge 103 is reground, the position of the cutting edge of the cutting edge changes and it becomes impossible to cut, so that the main body 100 cannot be reused and the main body 100 must be thrown away. There was a problem that it could not be done.

【0004】

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a thread cutting tool capable of exchanging a cutting edge.

【0005】

[Means for solving problems]

To achieve this object, the pipe threading tool according to claim 1 is attached to a die head and is engaged with a cam of the die head in a pipe threading tool used for thread cutting to form a pipe thread at an end of a steel pipe. A main body having a cam groove, a tip seat formed by recessing one surface side, and a screw fastening hole formed on the one surface side, and the above when mounted on the tip seat. A tip having a screw passage hole that communicates with a screw fastening hole, a blade portion in which the cutting edge has a thread shape, and a screw that passes through the screw passage hole and is screwed into the screw fastening hole. It has.

【0006】

According to the thread cutting tool for pipes according to claim 1, the tip mounted on the tip seat of the main body is screwed into the screw fastening hole of the main body while the screw passes through the screw passage hole of the tip to be screwed to the main body. It is sandwiched between the screw and detachably attached to the tip seat of the main body.

【0007】

The thread cutting tool for pipes according to claim 2 is a thread cutting tool for pipes that is attached to a die head and is used for thread cutting to form a thread for a pipe at an end of a steel pipe, and has a cam groove that is engaged with a cam of the die head. A main body having a tip seat formed by recessing the surface side, a screw fastening hole formed on the one surface side, and a thread shape of the cutting edge while being placed on the tip seat. A tip having a blade portion formed in, a clamp member having a screw insertion hole that can communicate with the screw fastening hole, and a screw that passes through the screw insertion hole and is screwed into the screw fastening hole. There is.

【0008】

According to the thread cutting tool for pipes according to claim 2, the tip mounted on the tip seat of the main body is screwed into the screw fastening hole of the main body while the screw passes through the screw insertion hole of the clamp member. It is sandwiched between the main body and the clamp member, and is detachably attached to the tip seat of the main body.

【0009】

The thread cutting tool for pipes according to claim 3 is the thread cutting tool for pipes according to claim 1 or 2, wherein the blade portion of the tip is a first blade portion formed on one side surface of the chip and the first blade thereof. It is provided with a second blade portion formed on the other side surface opposite to the side surface on which the portion is formed.

【0010】

The thread cutting tool for pipes according to claim 4 is the thread cutting tool for pipes according to claim 3, and the first blade portion of the tip has a thread whose cutting edge shape is different from that of the cutting edge of the second blade portion. It is formed in a shape.

【0011】

The thread cutting tool for pipes according to claim 5 is the thread cutting tool for pipes according to any one of claims 1 to 4, wherein n chips are used as a set, and the cutting blades of these chips are used. The thread shape is formed so as to be offset by 1 / n pitch.

【0012】

The thread cutting tool for pipes according to claim 6 is the thread cutting tool for pipes according to any one of claims 1 to 5, wherein the blade portion of the tip has a rake face having a predetermined rake angle and a flank surface having a predetermined clearance angle. The rake face is formed by being curved in an arch shape.

【0013】

The thread cutting tool for pipes according to claim 7 is the thread cutting tool for pipes according to any one of claims 1 to 6, wherein the tip is made of cemented carbide.

【0014】

The thread cutting tool for pipes according to claim 8 is the thread cutting tool for pipes according to any one of claims 1 to 7, wherein the tip is made of a highly rigid substance such as titanium carbide, titanium nitride, titanium carbonitide, or aluminum oxide. Combined and multi-layer coated.

【0015】

The thread cutting tool for pipes according to claim 9 is the thread cutting tool for pipes according to any one of claims 1 to 6, wherein the tip is made of a rigid sintered body mainly composed of cubic boron nitride or diamond.

【0016】

The tip according to claim 10 is used for the thread cutting tool for pipes according to any one of claims 1 to 9.

【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 thread cutting device 1 using the thread cutting tool 2a, 2b, 2c, 2d for pipes in the first embodiment of the present invention, and the thread cutting device 1 is schematically shown in the drawing. The thread cutting device 1 mainly includes a thread cutting tool 2a to 2d for pipes, a die head 3, and a motor (not shown), and the die head 3 to which the thread cutting tool 2a to 2d for pipes is attached is driven by a motor. This device is used for threading a pipe thread at the end of a steel pipe 4 fixed to a thread cutting device 1.

【0018】

The die head 3 is for attaching the thread cutting tools 2a to 2d for pipes, and is formed in an annular shape in the front view as shown in FIG. The threaded steel pipe 4 is inserted into the inner peripheral side of the die head 3 and fixed to the thread cutting device 1. The thread cutting tools 2a to 2d for pipes are for cutting the outer circumference of the end portion of the steel pipe 4 by the tips 5a to 5d fixed to one end side in the longitudinal direction of the main body 6, and the thread cutting tools 2a to 2d for pipes are used in the longitudinal direction. It is fixed to the die head 3 at equal intervals as well as in the radial direction with respect to the steel pipe 4. In addition, cutting edges 17 and 18 (see FIG. 2) having a predetermined thread shape are formed on the tips 5a to 5d of the thread cutting tools 2a to 2d for pipes, and the threads of these cutting edges 17 and 18 are formed. Each is formed at a position separated by 1/4 pitch. Here, the pipe thread cutting tool 2a, which is one of the pipe thread cutting tools 2a to 2d used in the thread cutting device 1, will be described with reference to FIGS. 2 (a), (b), and (c).

【0019】

2 (a) is a front view of the thread cutting tool 2a for pipes, FIG. 2 (b) is a lower side view of FIG. 2 (a), and FIG. 2 (c) is a side view of FIG. 2 (a). It is a side view. The thread cutting tool 2a for pipes includes a main body 6, a tip 5a, and a screw 7. The main body 6 forms the skeleton of the thread cutting tool 2a for pipes, and is formed in a rectangular parallelepiped shape. As shown in FIGS. 2 (a) and 2 (b), the cam groove 8 is inclined and recessed on the upper surface 6a of the main body 6. The cam groove 8 is engaged with a cam (not shown) rotatably arranged in the forward and reverse directions on the die head 3 (see FIG. 1). Since the cam is connected to the cam handle so as to rotate in the forward and reverse directions in response to the operation of the cam handle (not shown) provided in the thread cutting device 1, the thread cutting tool 2a for pipes is a cam handle. It is reciprocated in the radial direction of the die head 3 according to the rotation of the cam by the operation of.

【0020】

A bottom surface portion 9 for mounting the chip 5a is recessed in a corner portion (lower left side of FIG. 2A) on one end side in the longitudinal direction of the main body 6. As shown in FIG. 2 (a), the bottom surface portion 9 is formed in a substantially rectangular shape with a protruding front view in order to prevent the cutting edge 18 of the mounted tip 5a from interfering with the main body 6. ing. Further, the surface of the bottom surface portion 9 is formed in a flat shape as shown in FIGS. 2 (b) and 2 (c), and the bottom surface portion 9 is a flat plate-shaped chip 5a formed on the bottom surface of the chip 5a. It can be placed in close contact with the tablet. Contact portions 10 and 11 are vertically provided on the two sides of the bottom surface portion 9 toward the upper side (the front side of the paper surface in FIG. 2 (a)). The contact portions 10 and 11 are for abutting the side surfaces of the chip 5a placed on the bottom surface portion 9 and restraining the chip 5a by the contact. Since the inserts 10 and 11 can firmly fix the insert 5a to the main body 6 without rattling, accurate thread cutting can be performed.

【0021】

A screw fastening hole (not shown) in which a female screw is threaded on the inner surface is formed through a substantially central portion of the bottom surface portion 9, and a screw 7 described later is screwed. The main body 6 has a common shape for the thread cutting tools 2a to 2d for pipes (see FIG. 1), and the dimensions of the main body 6 and the position of the cam groove 8 are the conventional Oscar type shown in FIG. It is formed in a common shape with respect to the chaser and has compatibility. Therefore, the pipe thread cutting tools 2a to 2d in this embodiment can be used for the thread cutting device for the conventional Oscar type chaser.

【0022】

The tip 5a is fixed to the main body 6 and for threading the steel pipe 4, and is formed in a substantially rectangular plate shape in front view. Since the chips 5a to 5d use four chips as a set, the identification marks of the numbers 1 to 4 are engraved on each of the chips 5a to 5b in order, and the identification mark 12 of the number 1 is engraved on the chips 5a. Has been done. The thread cutting tools 2a to 2d for pipes are attached to the die head 3 in the order of the numbers of the identification marks 12.

【0023】

A screw passage hole (not shown) for passing the screw 7 is formed through the substantially central portion of the tip 5a. This screw passage hole communicates with the screw fastening hole of the main body 6 when the tip 5a is placed on the bottom surface 9 of the main body 6 and the side surface of the tip 5a is in contact with the contact portions 10 and 11. .. The tip 5a is sandwiched between the bottom surface 9 of the main body 6 and the seating surface of the screw 7 by screwing the screw 7 into the screw fastening hole of the main body 6 while passing through the screw passage hole. By such pinching, the tip 5a is fixed on the tip seat 9 of the main body 6 in a state where the side surface thereof is in contact with the contact portions 10 and 11 of the main body 6.

【0024】

A first blade portion 13 is provided on one side surface of the tip 5a (on the left side of FIG. 2A) in order to form a pipe screw on the outer periphery of the end portion of the steel pipe 4, and the first blade portion 13 is provided. A second blade portion 14 is provided on the other side surface (right side in FIG. 2A) opposite to the side surface to be provided. A rake face 15 and a flank surface 16 are formed on the first blade portion 13, and a cutting edge 17 is formed on a ridgeline portion where the rake face 15 and the flank surface 16 intersect. The cutting edge 17 is provided with a predetermined rake angle and clearance angle by the rake face 15 and the flank surface 16, and the rake face 15 is curved in a lateral view bow shape as shown in FIG. 2 (b). Is formed. Therefore, by selecting and replacing a tip having an appropriate rake angle and clearance angle according to the thread cutting situation such as the material of the steel pipe 4, thread cutting can be performed with high accuracy, and the chips generated by thread cutting are curved. Since the rake face 15 is guided and discharged, it is possible to prevent the chips from causing problems in thread cutting, for example, the work is interrupted due to the chips being entangled with each other.

【0025】

The cutting edge 17 has a bite portion and a complete thread portion formed by a pitch P, and in this embodiment, the number of threads in the complete thread portion is two threads. Further, the positions of the threads of the cutting edge 17 are arranged at positions shifted by 1 / 4P for each tip 5a to 5d. Specifically, the distance formed by the one end surface side (upper side of FIG. 2A) of the tip 5a and the apex of the screw thread is the distance m, and in the tip 5b, the distance is 1 / from the distance m. It is 4P smaller (m-1 / 4P), with chip 5c the distance is 1 / 2P smaller than the interval m (m-1 / 2P), and with chip 5d the distance is 3 / less than the interval m. It is reduced by 4P (m-3 / 4P). In this way, the deviation of the thread position of the cutting edge 17 that needs to be changed depending on the position attached to the die head 3 is adjusted by the inserts 5a to 5d. Therefore, even when a plurality of types of inserts are exchanged for threading pipe screws of different sizes, the main body 6 does not need to be changed, and the main body 6 can be shared by all types of inserts.

【0026】

Similar to the first blade portion 13 described above, the second blade portion 14 has a cutting edge 18 formed at a ridgeline portion where the rake face and the flank surface intersect. The cutting edge 18 is formed in a thread shape having a thread shape different from that of the cutting edge 17 of the first cutting edge portion 14, and indicates the name of the screw engraved in the vicinity of the cutting edge 17 and the cutting edge 18 of the tip 5a. It is identified by size mark 19 (eg G1 / 2, G3 / 8). As described above, cutting edges 17 and 18 having different sizes of thread shapes are formed on both side surfaces of the tip 5a. Therefore, by changing the mounting position of the tip 5a, it is possible to thread two types of pipe screws with one tip 5a.

【0027】

As described above, the cutting blades 17 and 18 are formed on the tip 5a which is detachably formed from the main body 6. Therefore, by constructing the chip 5a with a cemented carbide obtained by pressure-sintering tungsten carbide (WC) or the like, cutting edges 17 and 18 having excellent heat resistance and wear resistance can be obtained, and titanium carbide, titanium carbide, can be obtained. By coating the cutting blades 17 and 18 with a high-hard material such as titanium nitride, titanium carbide, aluminum oxide, or a combination of these for multi-layer coating, cutting blades 17 and 18 with even better heat and wear resistance can be obtained. , Thread cutting can be performed at high speed and dry.

【0028】

This will be explained by returning to FIG. When threading the steel pipe 4 with the thread cutting device 1, the die head 3 is rotated with respect to the steel pipe 4 and moved in the axial direction of the steel pipe 4 by driving a motor. By rotating and moving the die head 3, the tips 5a to 5d of the pipe thread cutting tools 2a to 2d thread the pipe thread on the outer periphery of the end of the steel pipe 4. When the threading of the steel pipe 4 is completed, the cam arranged on the die head 3 is rotationally moved by operating the cam handle in one direction, and the rotation of the cam causes the thread cutting tools 2a to 2d for the pipe to be moved to the steel pipe 4. It is moved backward in the radial direction. Therefore, the threaded steel pipe 4 can be taken out from the thread cutting device 1.

【0029】

By the way, in the thread cutting device 1 of the present embodiment, as described above, the die head 3 is configured to rotate and move by driving the motor, but the steel pipe 4 may be configured to rotate and move instead of the die head 3. Further, the die head 3 may be manually driven by the operator.

【0030】

As described above, the thread cutting tools 2a to 2d for pipes are configured so that the tips 5a to 5d can be replaced. Therefore, for example, if the cutting edges 13 and 14 are worn or damaged, the tips should be replaced. Only the cutting edges 17 and 18 can be replaced, and the main body 6 can be reused.

【0031】

Next, the second embodiment will be described with reference to FIG. In the thread cutting tool 2a for pipes of the first embodiment, a screw passage hole is formed through the tip 5a, and the tip 5a is screwed into the screw fastening hole of the main body 6 while the screw 7 passes through the screw passage hole. In contrast to the case where the thread cutting tool 22a for pipes of the second embodiment is configured to be attached to the main body 6, the tip 25a is attached to the main body 23 by the presser foot member 24 which is detachably attached to the main body 23. It is configured as follows. The same parts as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

【0032】

FIG. 3 (a) is a front view of the thread cutting tool 22a for a pipe, FIG. 3 (b) is a lower side view of FIG. 3 (a), and FIG. 3 (c) is a side view of FIG. 3 (a). It is a side view. The thread cutting tool 22a for pipes includes a main body 23, a presser foot member 24, and a tip 25a. Similar to the first embodiment described above, the cam groove 8 is inclined and recessed in the upper surface 23a of the main body 23. Further, a screw fastening hole (not shown) in which a female screw is threaded on the inner peripheral surface is formed through the substantially central portion of the main body 4 in the longitudinal direction.

【0033】

The presser foot member 24 is for fixing the tip 25a to the main body 23, and includes a presser foot 24a and a screw 24b. A screw insertion hole (not shown) is formed through one end side of the presser foot 24a, and the screw 24b is screwed into the screw fastening hole of the main body 23 while passing through the screw insertion hole, so that the presser foot is screwed. The other end side of 24a presses the chip 25a, and the chip 25a is attached to the main body 23 by such pressing. In this way, the tip 25a is attached to the main body 23 by being pressed by the presser foot member 24. Therefore, as in the case of the first embodiment described above, the tip 25a has a through hole for passing a screw. There is no need to form through. Therefore, the processing cost can be reduced, and it is possible to prevent the rigidity of the tip 25a from being lowered due to the reduction in the wall thickness of the tip 25a by forming the through hole.

【0034】

The chip 25a is provided with a first blade portion 26 on one side surface (left side of FIG. 2A), and the other side surface opposite to the side surface on which the first blade portion 26 is provided (FIG. 3). A second blade portion 27 is provided on the right side of (a)). Similar to the first embodiment described above, the first blade portion 26 and the second blade portion 27 are formed with a rake face and a flank surface, and the ridge line portion where the rake face and the flank surface intersect is formed. Cutting edges 28 and 29 are formed. The cutting edge 28 of the first blade portion 26 and the cutting edge 29 of the second blade portion 27 are formed to have the same pitch and thread shape, that is, the same thread size for pipes, and the positions of the threads. Are located in the same position as each other. Therefore, by changing the mounting position of the insert 25a, it is possible to obtain twice the thread cutting life of the conventional one.

【0035】

Although the present invention has been described above based on the examples, the present invention is not limited to the above examples, and it is easy that various improvements and modifications can be made without departing from the spirit of the present invention. It can be inferred.

【0036】

For example, in the thread cutting device 1 of each of the above embodiments, the thread cutting tools 2a to 2d and 22a to 22d for pipes are attached to the die head 3 in a set of four, but only one thread cutting tool for pipes is attached to the die head 3. As a matter of course, it is possible to have a configuration in which the number of units is increased or more than the number of units is attached as a set. Further, although cemented carbide was used as a material for forming the chips 5a to 5d and 25a to 25d, instead of this, a cubic boron nitride sintered body (PCBN) or a diamond sintered body (PCD) was used. A hard sintered body mainly composed of

【0037】

[Effect of the invention]

According to the present invention, the thread cutting tool for pipes has a cam groove that is engaged with a cam of a die head, a tip seat formed by recessing one surface side, and a screw fastening formed on the one surface side. A main body having a hole, a screw passing hole that communicates with a screw fastening hole when placed on a tip seat, a tip having a blade portion in which the cutting edge has a thread shape, and a screw passing hole. It is provided with a screw that passes through and is screwed into the screw fastening hole. Alternatively, the thread cutting tool for pipes has a cam groove that is engaged with a cam of a die head, a tip seat formed by recessing one surface side, and a screw fastening hole formed on the one surface side thereof. A main body, a chip having a blade portion that is placed on a tip seat and the blade shape of the cutting edge is formed into a thread shape, a clamp member having a screw insertion hole that can communicate with a screw fastening hole, and a screw insertion hole. It is equipped with a screw that passes through and is screwed into the screw fastening hole. Therefore, the tip fixed to the tip seat of the main body can be removed from the main body by loosening the screw screwed into the screw fastening hole of the main body. Therefore, there is an effect that the cutting edge of the chaser can be replaced by attaching and detaching the tip. For example, even when the cutting edge is worn or damaged, it is possible to replace only the cutting edge while using the main body as it is without replacing it. Further, when the cutting edge is changed to an expensive material, only the material of the insert needs to be changed without changing the material of the main body, so that there is an effect that the cost can be reduced. Further, since the chip on which the blade portion is formed can be formed of a hard sintered body, there is an effect that the blade portion having excellent heat resistance and wear resistance can be formed.

【0038】

Further, the blade portion of the chip includes a first blade portion formed on one side surface of the chip and a second blade portion formed on the other side surface opposite to the side surface on which the first blade portion is formed. It has. Therefore, by changing the mounting direction of the insert, thread cutting can be performed by the first blade portion and the second blade portion, so that there is an effect that one chip can obtain twice the thread cutting life of the conventional one. is there.

【0039】

Further, the first blade portion of the tip is formed with a thread shape in which the blade shape of the cutting edge is different from the blade shape of the cutting edge of the second blade portion. Therefore, by changing the mounting direction of the tip, there is an effect that two types of pipe screws can be threaded with one tip.

【0040】

Further, n chips are used as a set, and the thread shape of the cutting edge of these chips is formed by shifting the positions of the threads by 1 / n pitch. Therefore, even when threads for pipes of different sizes are threaded, there is an effect that the main body can be shared for a plurality of sets of chips of each size.

【0041】

Further, the blade portion of the tip includes a rake face having a predetermined rake angle and a clearance surface having a predetermined clearance angle, and the rake face is formed by being curved in a bow shape. Therefore, a tip having an appropriate rake angle or clearance angle can be selected and replaced with the tip according to the cutting conditions depending on the material of the steel pipe, so that the steel pipe can be threaded with high accuracy. effective. Further, since the chips generated by thread cutting are discharged along the rake face formed by bending in a bow shape, there is an effect that the work can be prevented from being interrupted due to the chips being entangled with each other. is there.

【0042】

The tip is made of cemented carbide. Further, the chip is multi-layer coated by combining a high-hard substance such as titanium carbide, titanium nitride, titanium carbide, or aluminum oxide. Therefore, by forming the tip with a cemented carbide, there is an effect that a cutting edge having excellent heat resistance and wear resistance can be obtained. Further, by applying the above-mentioned multilayer coating to the tip, there is an effect that a cutting edge having further excellent heat resistance and wear resistance can be obtained. The chip is made of a hard sintered body mainly composed of cubic boron nitride or diamond. Therefore, there is an effect that a cutting edge having excellent heat resistance and wear resistance can be obtained.

[Simple explanation of drawings]

[Figure 1]

It is a front view of the thread cutting device using the thread cutting tool for pipes in 1st Example of this invention.

[Figure 2]

(a) is a front view of a thread cutting tool for pipes, (b) is a lower side view of (a), and (c) is a side view of (a).

[Fig. 3]

It is the figure which showed the thread cutting tool for pipe of 2nd Example, (a) is the front view of the thread cutting tool for pipe, (b) is the lower side view of (a), (c) is ( It is a side view of a).

[Fig. 4]

It is a front view of the conventional thread cutting tool for pipes.

[Explanation of symbols]

2a ~ 2d, 22a ~ 22d Pipe thread cutting tool 3 die head 4 steel pipe 5a ~ 5d, 25a ~ 25d chips 6,23 body 7,24b screw 8 cam groove 9 Tip seat 13,14,26,27 Blade 13,26 1st blade (1st blade, part of blade) 14,27 2nd blade (2nd blade, part of blade) 17,18,28,29 Cutting edge 24a Presser foot (clamp member) 15 rake face 16 Escape surface P pitch