JPH10118842A - Small-sized, precise, multiple thread cutting method and its cutting lathe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve step exchanging works by setting a cutter shaft of high- speed rotation which is mounted on a cutter pedestal to being eccentric to a work of low-speed rotation via a built-in AC spindle motor. SOLUTION: Though a threading cutter 1 is rotated at high speed, the shaft center of the threading cutter 1 and the shaft center of a work A on a cutter spindle 3 rotated at low speed by a built-in motor 8 are deviated from each other and the threading cutter 1 is engaged with the work A just at one point so that, when the work A advances while rotating, a continuous thread is provided. When a six-thread screw is fabricated, it is cut by being rotated from the position of 0 deg. in the first, rotated by an angle obtained by dividing a rotation into six from the second, and cut in the same way as the first time by setting the position as a starting position. The whole setting is performed on an NC program.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-thread screw cutting machine for automatically dividing the number of screw threads, and more particularly to a small and precise multi-thread screw cutting method and a turning machine therefor.

[0002]

2. Description of the Related Art Conventional multi-threaded screw cutting machines often use gears or the like to divide the number of screw threads, but the method using these gears is difficult in terms of accuracy. In addition, no automated operation is known in the division operation, and the operation is complicated and the structure is complicated.

Subsequently, the applicant of the present invention has developed a multi-threaded screw cutting machine which eliminates these disadvantages, has a simple structure, is easy to operate, and can perform automatic threading. As shown in FIG. 8, this conventional multi-thread screw cutting machine is fixed at a fixed position by a pushing screw cutter 31 and is rotated at a high speed by a cutter driving motor 32 via a transmission mechanism as appropriate. ing. A is a male screw work, and the male screw cutter 3 is used.
The work A is fixed to one end of a middle spindle 33 provided off-axis from the cutter 31 by a set bolt 34 for a male screw work, a mounting body 35, and a tightening nut 36. ing. The middle spindle 33 has a male screw work A on the attachment side end that is larger in diameter than the main body, and the other end connected to a drive shaft 38 having a spline via a coupling 37. The drive shaft 38 can be rotated forward and backward by a drive motor 39, a drive chain 40 and a drive sprocket 41. Reference numeral 42 denotes a master spindle, which is formed in a cylindrical shape and has a hollow portion through which a middle spindle 33 penetrates. On the peripheral surface, a master screw 43 having the same pitch as the lead of the multi-threaded screw to be cut and one end of a pin holder 44 are provided. Fixed.

A pin cylinder 45 is provided at the other end of the pin holder 44, and a pin 46 is provided below the pin cylinder 45 in accordance with another command such as a hydraulic mechanism. The master spindle 42 has a bearing 4
7. With a female screw with the same pitch as the master screw 43,
It is rotatably mounted on a spindle head 49 via a master screw bearing 48 also serving as a bearing. Reference numeral 50 denotes a disk-shaped split plate, the circumference of which is fixed to the middle spindle at a position where it comes into contact with the pin 46. As described above, the conventional multi-thread screw cutting method is an eccentric cutting method performed when the work and the cutting tool are inscribed by eccentrically rotating the high-speed rotating cutter shaft with respect to the work rotating at a low speed together with the master screw. Cutting is a method in which the work shaft (main shaft) and the cutter shaft are rotated in the same direction, and the cutting is performed by the additional cutting method. In particular, a variable hydraulic motor is used for driving the spindle, and speed adjustment is performed by operating a speed control valve. And
The main shaft advances while being twisted following the master screw, and when one screw is cut up by a cutter rotating at a high speed, the main shaft retreats while reversing the same path as that at the time of forward movement, and is indexed to the next.

[0005]

SUMMARY OF THE INVENTION The present invention solves the problem by providing a small and precise multi-thread screw cutting method and a cutting lathe by improving the multi-thread screw cutting machine developed by the present applicant. There is a problem to be. That is, the present invention uses a conventional chucking device or cutter shaft device, and enables the chucking device to be attached in a work-toy relationship as it is, and the chucking strength is conventionally adjusted by the force of a disc spring. By using a rotating air cylinder, the chucking strength can be set more finely, so that the chuck pressure can be adjusted according to the work and the distortion and deformation of the work can be suppressed as much as possible did. On the other hand, the cutter shaft device allows various cutter holders to be mounted as it is, and adopts an AC spindle motor as the cutter spindle motor to stabilize the rotation of the cutter spindle, and to reduce the lead angle. An angle display is displayed on the CRT so that the angle can be seen at a glance at the time of adjustment.

[0006]

SUMMARY OF THE INVENTION The present invention has been developed to solve the above-mentioned conventional problems, and is a precision multi-start screw used for a camera part or the like using a small-sized precision lathe. In the method of cutting, a high-speed rotating cutter shaft mounted on a tool rest is eccentric to a workpiece rotating at a low speed via a built-in AC spindle motor,
An object of the present invention is to provide a small and precise multi-threaded screw cutting method characterized in that cutting is performed when a work and a cutting tool are inscribed by the eccentricity of the cutter shaft. In the eccentric cutting method, cutting is performed with a work shaft (main shaft). A method in which the cutter shaft is rotated in the same direction and the cutting is performed by a follow-up method, and the chip is cut up at a speed of about 2 to 10 seconds per strip while continuously discharging three-month chips. In the cutting method, in addition to the cutter shaft, as a comb-shaped lathe, it has a tooling area of about 170 mm on the X axis, and the maximum rotation speed is 6,000 rpm
m, and a multi-thread cutting method in which, in the eccentric cutting method, a setup program such as a lead and the number of strips is changed by a machining program to facilitate setup change.

Further, the present invention provides a screw cutter provided with a work fixed to a tip of a spindle mounted on a built-in motor incorporated in a spindle head and provided in close proximity to the work, and a rotation of the spindle. It is an object of the present invention to provide a small and precise multi-thread screw turning lathe characterized by cutting a multi-thread screw with a magnetic drum and a sensor to be controlled, a servo motor as a feed mechanism of the screw cutting cutter, and a ball screw mechanism. In the multi-thread cutting lathe, a male screw work fixed at a fixed position by a male screw cutter and driven to rotate at a high speed by a cutter driving motor through a transmission mechanism as appropriate is provided. A male work set opposite to the screw cutter is provided with a male screw at one end of a spindle arranged so as to be axially offset from the male screw cutter. A work set bolt, a multi-thread screw turning lathe fixed with a mounting body and a tightening nut, and further, in the multi-thread screw cutting lathe, a stator of a built-in motor is incorporated into a spindle by a firing spring, A magnetic drum for transmitting the rotation signal of the spindle is mounted on the opposite side of the mounting end of the male screw work.In addition, a manual push switch for stopping rotation and fixing forward / reverse rotation for fixing the male screw work is provided inside. Another object of the present invention is to provide a small-sized precision multi-thread screw turning lathe which is automatically operated by a program and cuts by moving a pushing screw cutter rotating at a high speed forward and backward according to a lead.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a multi-thread screw cutting according to the present invention, a work and a cutting tool are internally provided by eccentricizing a high-speed rotating cutter shaft mounted on a tool post with respect to a work rotating at a low speed by a built-in AC spindle motor. It is an eccentric cutting method that is performed at the time of cutting. The cutting is performed by a follow-up cutting method by rotating the work shaft (spindle) and the cutter shaft in the same direction, and two months per article while intermittently producing three-month chips. This is a method of rounding up at a speed of 10 seconds.

In addition to the cutter shaft of the present invention, a comb-type lathe has a tooling area of about 170 mm on the X-axis and can perform ordinary turning at a maximum rotation speed of 6,000 rpm.

Further, according to the present invention, according to the conventional method, it is necessary to change the master screw and the indexing plate in accordance with the change of the work, and it requires various costs for parts, time required for preparation, experience required for adjustment, Parts that were a major burden due to the difficulty of reproducibility, etc. were changed through the machining program, such as the setting of leads and the number of strips, so that the setup was easy and the parts were changed to multiple types and small lots. This is the best method for processing.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 7 show a small precision multi-thread screw cutting method and a turning machine according to the present invention.

First, a multi-thread screw turning lathe will be described with reference to FIG. 1. A cutting lathe according to the present invention is provided with a built-in motor 8 incorporated in a spindle head 11 and a tip of a cutter spindle 3 attached to the built-in motor 8. A screw cutter 1 provided with and fixed to the work A, and a magnetic drum 10 and a sensor 9 for controlling the rotation of the cutter spindle 3, and a servomotor 17 as a cutter feed mechanism. And a ball screw 13, and a small precision multi-start thread is cut by a multi-start thread turning lathe having this configuration.

In the conventional multi-thread screw cutting machine, since a multi-piece plate is used to divide a large number of screws, replacement is necessary every time the number of screw threads changes. Was large. In addition, since the lead of the multi-threaded screw and the left and right screws are replaced with the master screw each time, the accuracy of the work largely depends on the accuracy of the master screw.

Further, the cutting lathe of the present invention is configured such that the thread cutting cutter 1 is fixed at a fixed position by a male screw cutter, and is rotated at a high speed by a cutter driving motor 2 via a transmission mechanism as appropriate. Have been. Work A
Is a male screw work, which is installed to face the screw cutter 1. The work A is provided at one end of a cutter spindle 3 which is arranged off-axis from the screw cutter 1.
It is fixed by a set bolt 4 for screw work, a mounting body 5 and a tightening nut 6. The screw cutter 1 engages with the work only when the cutter is present on the upper side, but does not engage with the work A at other positions. A stator of a built-in motor 8 is incorporated into the cutter spindle 3 by shrink fitting, while a magnetic drum 10 for transmitting a rotation signal of the cutter spindle 3 is mounted on the opposite side of the mounting end of the work A. It is. Further, a chucking mechanism for fixing the work A is incorporated therein. It is to be noted that all commands for stopping the rotation of the cutter spindle and for normal rotation / reverse rotation can be automatically operated by a manual push switch or a program.

The thread cutting cutter 1, which is rotating at a high speed with respect to the rotation of the cutter spindle 3, is moved forward or backward in accordance with the lead to cut. In other words, the threading cutter 1 is rotating at high speed, but the axis of the threading cutter 1 and the axis of the workpiece A are shifted, and the threading cutter engages with the workpiece A at only one location. If the work A advances while rotating, the continuous screw is cut, and the screw 1 for cutting is rotating at a high speed, so that the first screw can be cut precisely in one step. To further explain the division of the number of threads, for example, in the case where a 6-thread screw is to be cut, the first rotation is performed from a position of 0 °, the cutting is performed, and one rotation (360 ° C.) is divided into six equal parts in advance from the second time. Rotation is performed by the angle (60 degrees), and the position is set as a start position. Thereafter, cutting is performed in the same manner as the first time. All the settings are made on the NC program. Although the present embodiment has exemplified the cutting of a male screw, the same effect can be obtained by the same method in the case of cutting a female screw.

According to the method of the present invention having the above-described structure, since the NC control is provided with the built-in spindle motor, there is no need to replace a master screw or a number of strips as in the related art, and the setup is changed. The work of (1) is remarkably improved, and since any lead and a large number can be set, it is possible to cope with any work and to perform high-precision cutting.

Next, a multi-thread screw turning lathe of the present invention will be described with reference to FIGS. First, the mechanism of the present invention has the following configuration.

[0018]

[Table 1]

The multi-thread thread turning lathe of the present invention thus constructed is roughly divided into a whirling area (see FIG. 2).
And chucking device (see Fig. 3) and cutter shaft (Fig. 4
5). In the figure, 14 is a cutter holder, 15 is a tool holder, 16 is a preset base, 17 is an X-axis slide, 19 is a toy mounting flange,
Reference numeral 20 denotes a built-in spindle, 21 denotes a rotary air cylinder, 22 denotes a flange, 23 denotes a cutting oil cover, 27 denotes a cabinet, 28 denotes an NC operation panel, 29 denotes a cutting oil tank, and 30 denotes an electric board.

Further, a description will be given of a method of exchanging work pieces and a method of setting up, which are main components of the multi-thread screw turning lathe of the present invention. How to replace the work toy First, loosen the chucking, hold down the work toy mounting flange, turn the yatoy mounting nut counterclockwise while keeping the main shaft from turning, remove the work toy mounting nut, and then turn the entire yatoy counterclockwise. As the drawbar gradually pulls out of the drawbar, you can completely remove the yatoy from the drawbar while holding down the yatoy, and then attach the replacement yatoy and check whether chips etc. are attached to the yatoy mounting part or yatoy. If you find it sticks, remove it. In such a state, the drawbar combined with the yatoy is screwed into the draw bar while holding down the yatoy mounting flange, and when the drawbar is screwed to some extent, the yatoy mounting nut is attached and temporarily tightened. Therefore, turn the jaws so that the jig that holds the work to the jaws and holds the work can be attached and detached, and adjust the position. Then, when the position of the jaws is determined, press the jaw mounting flange to prevent the main shaft from turning. Turn the mounting nut clockwise to secure it.

The air pressure is adjusted so that the work does not idle around the toy when the work is pressed. Setup change method First, move the entire cutter shaft device to a position where the work company can easily work, and replace the cutter holder with a holder that matches the work. At this time, note the distance from the cutter holder mounting surface to the cutting edge of the cutting tool in advance. Next, loosen the three screws fixing the turning shaft, and turn the turning shaft adjustment knob to adjust the turning shaft to an angle corresponding to the lead angle of the work. At that time, the angle is displayed on the CRT. In this way, when the angle is correct, the screw fixing the turning shaft is tightened and only the upper and lower portions on the back side are tightened. Further, the center height of the cutting tool is adjusted, and the upper cover of the vertical slide is removed, and one fixing screw (M6) at the center of the vertical slide on the moving side is loosened. Then, the distance from the center of the turning shaft to the center of the turning shaft is calculated based on the distance from the center of the turning shaft to the cutting tool attached to the cutter holder and the lead angle, and the index is calculated (AC = tan θ × BC). Then, turn the knob for height adjustment and adjust the height using the scale attached to the side of the slide and the scale attached to the knob for height adjustment as a guide. At this time, one fixing screw (M6) at the center on the moving side is tightened, and one fixing screw on the front side of the rotating shaft is tightened to mount the upper cover on the vertical slide.

[0022]

According to the present invention, there is provided a method for cutting a precision multi-thread screw used for a camera part or the like using a small-sized precision lathe. A high-speed rotating cutter shaft mounted on a table is eccentric, and the eccentricity of the cutter shaft causes cutting when the work and the cutting tool are inscribed. In the eccentric cutting method, cutting is performed with the work shaft (main shaft) and the cutter. The shaft is rotated in the same direction by the additional grinding method, and the three-month cutting chips are continuously released while being rounded up at a speed of about 2 to 10 seconds per article, and in the eccentric cutting method, X as a comb-type lathe other than the cutter shaft
The shaft has a 170mm whirling area and the maximum rotation speed is 6,000rpm in normal turning. In addition, in the eccentric cutting method, the setup is changed by changing the setting of the lead and the number of strips in the machining program. The machine is equipped with a Pilt-in spindle motor and is NC controlled, so there is no need to replace master screws or replace multiple split plates as in the past, and the work of setup change is greatly improved. In addition, since any lead and any number of leads can be set, it is possible to cope with any work and to perform high-precision cutting.

Further, in the conventional machine, it was necessary to replace the master screw and the multiple indexing plate with the change of the work.
Parts costs, time required for adjustment, experience required for adjustment and difficulty in reproducibility have been a heavy burden.However, according to the present invention, setting changes such as leads and number of lines can be changed with a machining program. Since it can be performed, setup change is easy, and it is most suitable for multi-product, small lot processing of parts.

The present invention also provides a screw cutter provided with a work fixed to the tip of a spindle mounted on a built-in motor incorporated in a spindle head and provided in close proximity to the work. A magnetic drum and a sensor to be controlled, a servomotor that is a feed mechanism of the thread cutting cutter, and a configuration of cutting a multi-thread screw by a ball screw mechanism. A male screw work fixed at a fixed position by a cutter and driven to rotate at a high speed by a cutter driving motor via a transmission mechanism as appropriate, and a male work set with the male screw work opposed to the male screw cutter. A set bolt for male screw work, a mounting body and In the multi-thread cutting lathe, which is fixed with a nut, a built-in motor is incorporated into the spindle by shrink fitting, and a spindle rotation signal is transmitted to the opposite side of the mounting end of the male screw work. A magnetic drum is attached, and inside it, the rotation stop for fixing the male screw work and the command of forward / reverse rotation are automatically operated by a manual lead switch or program, and the screw cutter rotating at high speed is advanced according to the lead. And since it is configured to cut back and retreat, it has many effects as follows.

A. By employing a Pilt-in spindle motor and using a machining method based on Cs contour control, it is possible to perform a more accurate thread cutting process without mechanical loss.

A high-resolution magnetic pulse coder is mounted on the rotating shaft of the main shaft, and can be indexed in 0.001 degree units instead of the conventional indexing plate. (C) The use of the built-in spindle motor eliminates the need to replace the master screw and the indexing plate at the time of setup change by changing the work, which has been done in the past, so that only the program change is required.

D) By performing the NC control, the lead and the number of the multi-thread screws can be set arbitrarily (minimum setting unit 0.0001 mm) by a program. (E) With the built-in spindle motor, it can be used as a normal AC spindle motor, and can perform general turning rather than multi-thread cutting.

(F) Since the body has a cutting oil cover, a cutting oil device can be used, and machining using cutting oil can be performed. By using the NC control, it is possible to easily set the rotation speed of the main shaft and the feed speed of the cutter shaft device and the like at the time of multi-thread threading processing by a program.

[Brief description of the drawings]

FIG. 1 is an explanatory schematic diagram showing a multi-thread screw turning lathe of the present invention.

FIG. 2 is an explanatory schematic diagram showing a tooling area of the cutting lathe in FIG. 1;

FIG. 3 is an explanatory schematic diagram showing a chucking device in the cutting lathe of FIG. 1;

FIG. 4 is an explanatory schematic diagram showing a cutter shaft in the cutting lathe of FIG. 1;

FIG. 5 is an explanatory schematic diagram showing a cutter shaft of the cutting lathe of FIG. 1;

FIG. 6 is an overall schematic diagram of the cutting lathe shown in FIG.

FIG. 7 is an overall schematic diagram of the cutting lathe shown in FIG.

FIG. 8 is an explanatory schematic diagram showing a conventionally known multi-thread thread turning lathe.

[Explanation of symbols]

1 Cutter for thread cutting 2 Cutter spindle motor 3 Cutter spindle 4 Set bolt 5 Mounting body 6 Tightening nut 7 Stator 8 Rotor 9 Sensor 10 Magnetic drum 11 Spindle head 12 Turret 13 Ball screw 14 Cutter holder 15 Byte holder 16 Preset base 17 X Axis slide 18 Rotary encoder 19 Jaw mounting flange 20 Built-in spindle 21 Rotating air cylinder 22 Flange 23 Vertical slide 24 Rotating axis 25 AC spindle motor 26 Cutting oil cover 27 Cabinet 28 Cutting oil tank 30 Electrical board 31 Male screw cutter 43 Master screw 44 Pin Holder 45-pin cylinder 46-pin 50-way split plate A, B Workpiece M Servo motor

Claims (7)

[Claims] 1. A method for cutting a precision multi-thread screw used in a camera part or the like using a small-sized precision lathe, wherein the workpiece is mounted on a tool post with respect to a workpiece rotating at a low speed via a built-in AC spindle motor. A small and precise multi-thread screw cutting method, characterized in that a high-speed rotating cutter shaft is eccentric and cutting is performed when the workpiece and the cutting tool are inscribed by the eccentricity of the cutter shaft. 2. In the eccentric cutting method, cutting is performed by a follow-up cutting method by rotating a work shaft (main shaft) and a cutter shaft in the same direction, and continuously releasing three-month chips. 2. The small precision multi-thread cutting method according to claim 1, wherein the thread is cut up at a speed of about 2 to 10 seconds per article. 3. The eccentric cutting method according to claim 1, wherein the comb-type lathe has a tooling area of about 170 mm on the X-axis in addition to the cutter shaft, and performs a normal turning process at a maximum rotation speed of 6,000 rpm. The small precision multi-start thread cutting method described. 4. The small precision multi-thread screw cutting method according to claim 1, wherein in the eccentric cutting method, setting change of a lead, the number of strips, and the like is performed by a machining program to facilitate setup change. 5. A screw cutter provided in the vicinity of a work and fixed to a tip of a spindle attached to a built-in motor incorporated in a spindle head, and a magnet for controlling rotation of the spindle. A small precision multi-thread screw turning machine characterized in that a multi-thread screw is machined by a drum motor, a sensor, a servo motor which is a feed mechanism of the screw cutting cutter, and a ball screw mechanism. 6. In the multi-thread cutting lathe, a male screw work fixed to a fixed position by a male screw cutter and driven to rotate at a high speed by a cutter driving motor via a transmission mechanism as appropriate is provided. The male work set opposite to the male screw cutter is fixed to one end of a spindle arranged to be offset from the male screw cutter with a set bolt for the male screw work, a mounting body, and a tightening nut. 6. The small precision multi-thread thread turning lathe according to claim 5, wherein 7. A multi-thread cutting lathe, wherein a built-in motor stator is incorporated in the spindle by a firing spring, and a magnetic signal for transmitting a rotation signal of the spindle is provided on the opposite side of the mounting end of the male screw work. A drum is mounted, and inside it, rotation stop for fixing the male screw work and forward / reverse rotation command are automatically operated by a manual push switch or program, and the pushing screw cutter rotating at high speed is advanced and retracted according to the lead. 7. The small precision multi-thread screw turning lathe according to claim 5, wherein the turning is performed by cutting.