JPH0516064U - Screw cutting tool - Google Patents

Abstract

(57) [Abstract] [Purpose] One thread cutting work accurately and accurately threads threads, and finely adjusts the outer diameter of the male screw, that is, the inner diameter of the thread cutting tool. [Structure] A retractable cutting blade body by an adjusting portion is internally provided in a hollow tip portion formed in a cylindrical portion and a conical portion, and a plurality of cutting blade bodies 25, 25a are provided in a disc portion of the cutting blade body. The cutting body
A flat portion and a taper portion, which are in sliding contact with the inner surface of the cylindrical portion and the conical portion, are formed on the outer surfaces of 25, 25a, ... ,
By screwing the fixed screw into the fixed screw hole and the stepped long hole, the screw thread with a plurality of threads can be used for one thread cutting work, and the screw thread is beautiful and precise and precise. Also, the outer diameter of the male screw is set to a predetermined value by adjusting the inner diameter of the thread cutting blade.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thread cutting tool capable of efficiently and precisely cutting a male screw and finely adjusting the inner diameter.

[0002]

[Prior Art]

 Conventionally, as a tool for cutting a male screw, a round piece die a, a checker b, a screw cutting byte (not shown), etc. are used for thread cutting by a lathe and the like, but as shown in FIG. In the round piece die a, a split c is provided at one place, and the opening degree of the split c is adjusted with a bolt (not shown) to adjust the opening degree of the split c and the inner diameter of the round die a. Due to the opening of the split c, the diameter of the circular piece die a is not expanded as a whole, and it becomes, for example, an elliptical type or a rice ball type, so that the circularity cannot be maintained and the inner diameter cannot be adjusted. It had the drawback that it could not be threaded.

In a checker b as shown in FIG. 9, a plurality of cuts e, e ′ ... Are provided in the ring body d in the center direction, and cutting edges f, f are formed in the cuts e, e ′. "... is mounted so that it can be retracted and retracted. The machining method is to project the cutting edges f, f '... from the notches e, e' ... to the inside of the ring body d and perform thread cutting on the inner circumference of the checker b. After finishing the machining, the cutting edges f, f '... are retracted so that the checker b is free from the work and the checker b is retracted and separated. As a result, the cutting edges f, f' ... Since it was not completely fixed, it was not precise and highly accurate, and had the drawback that it had to be finished again, for example, with the above-mentioned round piece die a after thread cutting with the checker b.

Further, in a thread cutting bit (not shown) generally used in a lathe, an NC lathe, a machining center, etc., the cutting edge of the thread cutting bit has only one ridge, and therefore, in the thread cutting of the lathe and the like. However, there is a drawback that the efficiency is low because the thread cutting process of rotating the work and moving the thread cutting tool has to be performed many times.

[0005]

[Problems to be solved by the device]

 The present invention provides a thread cutting tool capable of precisely threading a thread with a single threading operation and finely adjusting the outer diameter of the male screw, that is, the inner diameter of the thread cutting tool. To do.

[0006]

[Means for Solving the Problems]

 The present invention is based on the above-mentioned conventional technology, and the problem that the work piece screw part of the work cannot be processed into a perfect circle in the round piece die, the problem that the thread is not precise and the accuracy is poor in the checker, and the final finishing is required. In view of the problem of inefficiency, a retractable cutting blade body with an adjusting portion is internally provided in the tip cavity formed in the cylindrical portion and the conical portion, and a plurality of cutting blade bodies are provided in the disc portion of the cutting blade body. A flat portion and a taper portion that slidably contact the inner surface of the cylindrical portion and the conical portion are formed on the outer surface of the cutting blade, and a fixing screw hole is formed in the taper portion and a stepped long hole is formed in the conical portion. By fixing the fixing screw to the fixing screw hole and the stepped long hole, the screw thread with multiple threads can be used for a single threading operation, and the thread can be neat, precise and accurate. By processing and adjusting the inner diameter of the thread cutting tool. In the manner set into a predetermined size of the male screw outer diameter, it is obtained by solving cents above problems.

[0007]

[Action]

 In the present invention, a workpiece is fixed to a chuck or a machining table centered on a machining center, and a screw cutting blade tool is attached to a spindle such as a lathe, an NC lathe, a machining center, or a tapper, and the workpiece or the thread cutting machine is rotated. The cutting tool is inserted into the threaded part of the thread cutting tool so that the cutting edge of the thread cutting tool makes external contact with the threaded part of the workpiece, and the processed threaded part is inserted into the threaded part. The thread to be processed of the work fixed by the rotation of the cutting tool is threaded, and the lathe is rotated in the reverse direction to separate the work and the thread cutting tool and finish the processing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a thread cutting tool according to the present invention. In a thread cutting operation using the thread cutting tool 1, the thread cutting tool 1 rotates on its own axis. The workpiece W may rotate, or the workpiece W may rotate, and the processing machine for mounting the thread cutting tool 1 or the workpiece W is a lathe, an NC lathe, a tapper, a machining machine having a reverse rotation mechanism such as a machining center. The thread to be processed of the work W is screwed onto the spindle of the work W by an automatic attachment / detachment device or by manually attaching and rotating the screw cutting tool 1 or the work W, and sliding the screw cutting blade 1 or the work W so that they contact each other. The roundness of the portion R is maintained and the external thread is threaded.

Reference numeral 2 denotes a cylindrical main body, and a mounting body 3 to a spindle (or chuck) such as a lathe is fixedly attached to the side of the base end of the cylindrical main body 2, and the base end of the cylindrical main body 2 is fixed. A retractable adjustment unit 4 that can be operated externally is provided inside, and a thread cutting blade 5 is provided inside the tip of the cylindrical main body 2.

Reference numeral 6 denotes a cylindrical portion on the base end side of the cylindrical main body 2. A partition wall 7 is integrally formed inside the cylindrical body 6, and a square through hole 8 is formed in the central portion of the partition wall 7. In addition, a screw portion 9 for coupling is formed on the outer side of the base end of the cylindrical portion 6, and a tapered conical portion 10 with a widened tip is integrally formed at the distal end portion of the cylindrical portion 6.

Reference numeral 11 denotes a cylindrical portion on the front end side of the mounting body 3, and inside the cylindrical portion 11, a screw portion 12 for connection that is screwed into the screw portion 9 of the cylindrical portion 6 of the cylindrical main body 2 is formed. At the same time, a cylindrical mounting portion 13 for a spindle (or chuck) such as a lathe is formed integrally with the base end of the cylindrical portion 11 of the mounting body 3 in a protruding state.

Reference numeral 14 denotes a base end cavity portion formed inside the base end of the cylinder portion 6 of the cylindrical main body 2 and inside the tip end of the cylinder portion 11 of the mounting body 3 in which the adjusting portion 4 is installed. A fine adjustment nut 15 for adjusting dimensions is provided inside the screw 14, and a screw hole 16 is provided at the center of the fine adjustment nut 15.

Reference numeral 17 denotes a fine adjustment square bolt, and the fine adjustment square bolt 17 has screw portions 18, 18 a ... Formed only on the outer peripheral portion of the square of a square pole. The square bolt 17 is inserted into the through hole 8 of the quadrangular partition wall 7, and the base end of the fine adjustment square bolt 17 projects into the base cavity 14 and is screwed into the screw hole 16 of the fine adjustment nut 15. At the same time, the tip of the fine adjustment square bolt 17 projects into the tip cavity portion 19 inside the tip of the cylindrical portion 6 of the cylindrical body 2.

Reference numerals 20, 20 a, ... Are adjustment fitting holes for finely adjusting the size, which are formed in the outer peripheral surface of the fine adjustment nut 15, and the base end cavity portion 14 is provided at the base end portion of the cylindrical portion 6 of the cylindrical main body 2. Slotted adjustment grooves 21 and 21a, which communicate with the inside, are formed in the outer peripheral direction, and an adjustment tool (not shown) is fitted into the adjustment fitting holes 20, 20a ... through the adjustment grooves 21 and 21a. Then, the fine adjustment nut 15 is rotated, and the fine adjustment square bolt 17 is interlocked to move back and forth.

Reference numeral 22 denotes a cutting blade main body of the screw cutting blade tool portion 5, and the cutting blade main body 22 has an outer surface shape substantially matching the tip cavity portion 19 formed inside the cylindrical portion 6 and the conical portion 10. A disk portion 23 is formed at the base end of the main body 22, and a fitting hole 24 having a screw thread is formed at the center thereof, and the tip of the fine adjustment square bolt 17 is screwed into the fitting hole 24. Accordingly, the cutting blade body 22 is made replaceable, and the cutting blade body 22 is fixed in the axial direction of both, so that the dimensions of the cutting blade body 22 are adjusted by synchronizing the advance and retreat of both.

25, 25a ... Are cutting blade bodies divided into five (odd and plural), and the cutting blade bodies 25, 25a ... Are integrally formed so as to project from the disc portion 23 in the distal direction. The outer surface of the base end portion of the cutting blades 25, 25a is formed into flat portions 26, 26a, which are slidably contacted with the inner surface of the cylindrical portion 6, and the middle portion of the cutting blades 25, 25a ... following the flat portions 26, 26a. The outer surface is formed by tapered portions 27, 27a that are slidably in contact with the inner surface of the conical portion 10, and the cutting blades 28, 28a are formed on the inner surfaces of the tips of the cutting blade bodies 25, 25a that follow the tapered portions 27, 27a. The cutting blades 25, 25a, ... Are made of a spring material or the like that is capable of flexing to some extent.

Denoted at 29, 29a are taper portions 27, 27a of the cutting blades 25, 25a, ... Fixing screw holes, which are formed in a concave shape on the outer surface after size adjustment, and face the fixing screw holes 29, 29a. At the position, the stepped elongated holes 30, 30a ... Are bored and formed in the conical portion 10, and the fixed screw holes 31, 30a are screwed through the stepped elongated holes 30, 30a. The inner surface of the conical portion 10 and the outer surfaces of the tapered portions 27, 27a ... Are tightly attached to each other.

At the tips of the cutting blades 28, 28a ..., Cutting edges 32, 32a having several threads are formed on the inner peripheral surface thereof, and the cutting edges 32, 32a. The side of the workpiece W that first bites into the thread R to be processed has two or three ridges slanted down to facilitate biting, and the edges of the cutting edges 28, 28a ... Are perpendicular to the cutting edges 32, 32a. Forming holes 33, 33a for cutting blade surfaces on the side surfaces, and forming chip escape grooves 34, 34a on the side surfaces of the cutting edges 28, 28a, which are directed toward the outside of the holes 33, 33a for cutting blade surfaces. There is.

The cutting surfaces 33, 33a ... and the chip escape grooves 34, 34a ... Are formed between the rear side surfaces of the adjacent front cutting edges 28, 28a. A flat detent 35 is provided at the base end of the mounting body 3 to the spindle (or chuck) of an NC lathe or the like, and a loosening screw 36 is provided at the joint between the cylindrical body 2 and the mounting body 3.

Next, the operation of the thread cutting tool according to the present invention will be described. A workpiece W is fixed to a chuck or a working table at the machining center, and the thread cutting tool 1 is attached to a spindle such as a lathe, an NC lathe, a machining center or a tapper. The mounting body 3 is attached, the screw cutting blade 1 is rotated, and the work W or the screw cutting blade 1 is advanced, slid, and lowered to be brought into contact with the workpiece W to be processed R, and the cutting edge 32 of the screw cutting blade 1 is The thread R to be machined is fitted into the threaded portion 37 of the thread cutting blade 1 so that the outer surfaces 32a ... Contact, and the thread R to be machined of the workpiece W fixed by the rotation of the thread cutting blade 1 is threaded to form a lathe. And the like are reversely rotated to separate the work W and the thread cutting tool 1, and the processing is completed.

In the above-mentioned thread cutting process, the work W is fixed and the thread cutting blade 1 is rotated, but the two are reversed, that is, the work W is rotated while the thread cutting blade 1 is fixed. good.

Further, the inner diameter of the thread cutting portion 37 of the thread cutting blade tool 1 can be adapted to correspond to the outer diameter of the thread R to be processed of the work W, and the adjustment fitting holes 20, 20 a of the fine adjustment nut 15 can be adjusted. Insert the tool and turn the fine adjustment nut along the adjustment grooves 21 and 21a to rotate the fine adjustment nut 15. The fine adjustment square bolt 17 and the through hole 8 are both square and screwed together. Since the fine adjustment square bolt 17 does not rotate, the fine adjustment square bolt 17 advances and retreats according to the rotation of the fine adjustment nut 15, and the fine adjustment square bolt 17 advances and retracts according to the advance and retreat of the fine adjustment square bolt 17. Since the tip of the square bolt 17 and the disk portion 23 of the cutting blade body 22 are fixed in the axial direction, the cutting blade body 22 moves back and forth, and as a result, for example, when the cutting blade body 22 is retracted and retracted, The base ends of the tapered portions 27, 27a of the bodies 25, 25a ... Enter the inside of the cylindrical portion 6 from the conical portion 10, The taper portions 27, 27a ... Abut on the connecting corner portion of the portion 10 and the cylindrical portion 6 and the taper portions 27, 27a .. are bent inward, and in response to this action, the cutting edge 32 which is the tip of the cutting blade body 22. , 32a are bent inward, so that the inner diameter of the threaded portion 37 is finely adjusted so that the inner diameter of the threaded portion 37 is reduced.

Then, the taper portions 27, 27a of the cutting blades 25, 25a ... are moved in the axial direction by a slight amount, and the taper portions 27, 27a, 27a of the conical portion 10 are provided at predetermined positions. 27a ... fixed screw holes 29, 29a ... are positioned, and after such positioning and dimension determination of the inner diameter of the threaded portion 37, fixed screw holes 29, 29a ... and fixed screw holes 29, 29a ... If the heads of the fixed screws 31, 31a ... are located in the stepped long holes 30, 30a ... by screwing the 31, 31a ..., the taper portion 27, 27a is pulled toward the inner surface of the conical portion 10, and the inner surface of the conical portion 10 and the outer surfaces of the tapered portions 27, 27a are fastened in contact with each other so that the tapered portion 27, 27a of the cutting blade body 22 is a conical portion. It is closely fixed to the inner surface of the part 10.

Further, since the cutting blades 25, 25a ... Are plural and odd in number such as three, five and seven, each of the cutting blades 25, 25a which comes into contact with the thread R to be processed. Does not have the other cutting blade 25, 25a, ... at the opposite position across the processed screw R, and the respective cutting blades 25, 25a ... contact the processed screw R evenly. When cutting, the cutting force is balanced on average, and the cutting blades 25, 25a ... rotate smoothly around the thread R to be machined, and the thread R to be machined is accurately threaded in a perfect circle. Or to finish the threaded state of the thread R to be machined neatly.

If the cutting blade bodies 25, 25a of the cutting blade body 22 are not fixed by the fixing screws 31, 31a, ..., The inner surface of the conical portion 10 and the taper portions 27, 27a during machining. The outer surfaces of the cutting blades come into contact with each other and vibrate to generate minute vibrations, which makes it impossible to perform accurate round threading, or even if the cutting blade bodies 25, 25a of the cutting blade body 22 have four or six blades. In the case of an even number, the cutting blades 25, 25a in two directions are present at opposite positions with respect to the center of the thread R to be machined, and although theoretically unknown, vibration or slight vibration may occur. If it is difficult to perform thread cutting in an exact circular state, or if the number of cutting blade bodies 25, 25a of the cutting blade body 22 is 3, the thread condition becomes rough, the accuracy becomes low, or 7 In the above cases, the cutting blade body 22 becomes small, making it difficult to manufacture, and it becomes difficult for chips to escape.

[0026]

[Effect of the device]

 In short, according to the present invention, the mounting body 3 is attached to the cylindrical body 2, the cylindrical body 2 is formed of the cylindrical portion 6 and the conical portion 10, and the tip cavity portion 19 formed in the cylindrical portion 6 and the conical portion 10 is provided with the adjusting portion. 4, the retractable cutting blade main body 22 is internally provided, a plurality of cutting blades 25, 25a ... Are provided in the disc portion 23 of the cutting blade main body 22, and the cylindrical portion is provided on the outer surface of the cutting blades 25, 25a. Since the flat portions 26, 26a and the taper portions 27, 27a that slidably contact the inner surface of 6 and the conical portion 10 are formed, the plurality of cutting blade bodies 25, 25a in the thread cutting blade tool 1 are pulled in by the same amount and cut. The inner edge positions of the cutting blades 28, 28a of the blades 25, 25a ... are the same, the threaded portion 37 is in a perfect circle, the centripetality can be improved, and the cutting edges 32, 32a ... are located. The inner diameter of the part 37 can be finely adjusted to correspond to the outer diameter of the threaded part R to be processed, and the inner diameter of the threaded part 37 can be adjusted even when the cutting blade body 22 is replaced. The diameter can be adjusted, and fixed screw holes 29, 29a ... Are formed in the tapered portions 27, 27a ... And stepped long holes 30, 30a. Since the fixing screws 31, 31a ... Are screwed into the 29a ... The cutting blade bodies 25, 25a of 22 are prevented from chattering and microvibration is prevented, so that the thread-cutting work of the thread R to be processed can be accurately and neatly performed.

Further, in the thread cutting process in which the screw cutting blade 1 is rotated and the work W is fixed, it is impossible to perform the lathe process for rotating the work W in the deformed state. Threading can be performed on lathes, which are widely used for products.

Further, in comparison with the conventional lathe processing using a thread cutting tool, in the thread cutting tool 1 of the present embodiment, since the cutting edges 32, 32a ... Have a plurality of threads, the work W Further, the thread cutting process can be completed by one reciprocation of the thread cutting tool 1, and the efficiency can be improved.

Further, since the plurality of cutting blades 25, 25a ... Is constituted by an odd number, preferably five, when the screw cutting tool 1 rotates, the five cutting blades 25, 25a. The threaded portion R can be smoothly rotated while being in contact with it evenly, so that the thread of the threaded portion R to be machined can be neat and can be threaded into a perfect circle.

Further, in the retractable adjusting part 4, a partition wall 7 is formed in the cylindrical part 6 and a through hole 8 is bored in the partition wall 7, and a fine adjustment nut 15 is provided in the proximal cavity 14 of the cylindrical part 6. And a screw hole 16 is formed in the fine adjustment nut 15, and a fine adjustment square bolt 17 is inserted into the through hole 8 of the partition wall 7. The base end of the fine adjustment square bolt 17 is a fine adjustment nut. In addition to being screwed into the screw holes 16 of 15, the tip of the fine adjustment square bolt 17 is attached to the disc portion 23 of the cutting blade body 22, and the fine adjustment nut 15 is provided with adjustment fitting holes 20, 20a ... Since the adjustment grooves 21 and 21a are provided in the cylindrical portion 6, the dimension of the cutting blade body 22 inside the screw cutting blade tool 1 can be adjusted from the outside of the cylindrical body 2 of the screw cutting blade tool 1, thus improving operability. Its practical effects are extremely great.

[Brief description of drawings]

FIG. 1 is a front view of a thread cutting tool according to the present invention.

FIG. 2 is a cross-sectional view of the thread cutting blade of FIG.

FIG. 3 is an exploded perspective view of the thread cutting blade of FIG.

4 is an end view taken along the line AA of FIG.

5 is a bottom view of the thread cutting tool shown in FIG. 1 as viewed from the cutting edge side.

6 is a plan view seen from the mounting side of the thread cutting blade of FIG. 1. FIG.

FIG. 7 is a front view showing a thread cutting state of a work.

FIG. 8 is a perspective view of a conventional round piece die.

FIG. 9 is a schematic front view of a conventional checker.

[Explanation of symbols]

 2 Cylindrical body 3 Mounting body 4 Adjusting part 6 Cylindrical part 7 Partition wall 8 Through hole 10 Conical part 14 Base end cavity 15 Fine adjustment nut 16 Screw hole 17 Fine adjustment square bolt 19 Tip cavity 20, 20a… Adjustment fitting Hole 21, 21a Adjustment groove 22 Cutting blade body 23 Disc portion 25, 25a… Cut blade body 26, 26a… Flat portion 27, 27a… Taper portion 29, 29a… Fixed screw hole 30, 30a… Stepped long hole 31, 31a… Fixed screw

Claims (3)

[Scope of utility model registration request] 1. A mounting body is attached to a cylindrical main body, and the cylindrical main body is formed of a cylindrical portion and a conical portion, and a retractable cutting blade main body by an adjusting portion is internally provided in a tip hollow portion formed in the cylindrical portion and the conical portion. Then, a plurality of cutting blades are provided on the disc portion of the cutting blade body, and a flat portion and a taper portion which are in sliding contact with the inner surfaces of the cylindrical portion and the conical portion are formed on the outer surface of the cutting blade body, and the tapered portion is formed. A thread cutting blade characterized in that a fixed screw hole is formed, a stepped long hole is formed in a conical portion, and a fixed screw is screwed into the fixed screw hole and the stepped long hole. 2. The thread cutting blade according to claim 1, wherein the plurality of cutting blades are constituted by an odd number, preferably five. 3. A retractable adjusting part, wherein a partition is formed in the cylindrical part, a through hole is bored in the partition, a fine adjustment nut is provided in the proximal cavity of the cylindrical part, and the fine adjustment nut is provided. A screw hole is formed in the partition wall, and the fine adjustment square bolt is inserted into the through hole of the partition wall. The base end of the fine adjustment square bolt is screwed into the screw hole of the fine adjustment nut, and 3. The thread cutting blade tool according to claim 1, wherein the tip is attached to the disc portion of the cutting blade body, the fine fitting nut is provided with an adjusting fitting hole, and the cylindrical portion is provided with an adjusting groove.