KR100821992B1 - The compacted nc milling machine - Google Patents

Abstract

A compacted NC milling machine is provided to move a tool or a workpiece by using an electromagnetic force and support the rotation operation or the movement of the tool or the workpiece by an air bearing. A base(120) has a knob(122) and a plate shape. A column(200) has a lower end supported on one upper side surface of the base and an upper end curved toward the central portion of the base. A Z-axis stage(500) is fixed to the upper end of the column. The stage includes a space for vertical movement. A guide rail for Z-axis movement is formed at one side of the space. The Z-axis stage allows a tool to move by an electromagnetic force and an air bearing. A spindle holder(620) allows the fixture of a spindle(600) thereto. The spindle is formed at the lower end thereof with a tool chuck. A table(300) helps a workpiece chuck(310) to be mounted onto a predetermined position of the spindle. An XY-axis stage(400) allows a moving force delivered to the table to be generated by the electromagnetic force and the air bearing.

Description

Table Type NC Milling Machine {The compacted NC milling machine}

The present invention relates to a table-type NC milling machine, and more particularly, for precise processing of small parts, the size is not only made small so that the user can easily carry it, but also to reduce the energy consumed for processing. Table top NC milling machine.

One of the machine tools, the milling machine, moves the tool on the upper side of the table on which the work is placed in the vertical direction (Z axis direction) and the table moves in the horizontal direction (X axis direction) or vertical direction (Y axis direction). It is to ensure that the workpiece is processed.

In particular, the NC milling machine allows the workpiece to be processed as programmed in the computer while the table and spindle are moved to the X, Y, and Z axes under the control of the NC controller with the workpiece and tool origin set. As a result, it is possible to increase the productivity as well as to enable more precise machining than the general milling machine.

By the way, the conventional milling machine is manufactured and supplied in the medium and large size, as it is well known, it was necessary to expand the separate space for the installation of the mechanical device, and the rotational or moving operation of the tool and the workpiece is composed of the electric motor As a result, the energy consumption of the drive was high, and there was a big limitation in precise machining of small workpieces.

On the other hand, the applicant has developed a 'miniature stage device using a permanent magnet movable linear motor and air bearing' (Publication No. 10-2007-0052524) for the purpose of applying to tables or stages of machine tools as disclosed in the Korean Patent Office. I've done it. That is, while using the electromagnetic force as a means for the movement of the table or the stage on which the tool or the workpiece is mounted, while the table or the stage is moved by the electromagnetic force, the table or the stage is injured from the base by the pneumatic pressure provided by the air bearing. By being able to be moved, the above-mentioned technique is applied to a table or stage of a machine tool for precisely machining small parts, which leads to a step that can significantly reduce the size of the machine tool.

The present invention has been made to improve the problems of the prior art as described above, for precise processing of small parts, the size is not only made small so that the user can easily move, but also reduce the energy consumed for processing It is an object of the present invention to provide a table-type NC milling machine that can be used.

In addition, the present invention aims to provide a table-type NC milling machine capable of more precise processing by allowing the movement of the tool or the workpiece not only by the electromagnetic force, but also by the rotation and movement of the tool or the workpiece is supported by the air bearing. will be.

The present invention is configured as follows to achieve the object as described above. That is, the present invention is formed so that the spindle equipped with the rotary operation tool is movable in the vertical direction (Z axis direction) while the XY axis stage in which the workpiece is mounted is transverse direction (X axis direction) and longitudinal direction (Y axis) An NC milling machine, which is formed to be movable in a direction and is formed to process a workpiece by a tool, comprising: a plate-shaped base having a handle for movement on a side thereof; A column having a lower end supported on one side of an upper surface of the base and an upper end bent toward a central portion of the base; It is fixedly coupled to the top of the column and a square shankdong space is formed on the inside to guide the vertical movement of the tool, the Z-axis movement guide rail is formed on one side of the shankdong space, the movement of the tool is electromagnetic Z-axis stage formed to be made by; A spindle holder coupled to the shank east space of the Z-axis stage while the spindle is fixedly mounted therein; A spindle fixedly mounted to the spindle holder and formed at a lower end thereof so that a tool chuck is formed to allow mounting of a tool, and a rotation operation is performed; A table formed to enable mounting of the workpiece chuck in a position directly below the spindle; An XY axis stage formed between an upper side of the base and the table for movement in the horizontal direction (X axis direction) and the vertical direction (Y axis direction) of the table, the transfer force being transmitted to the table by the electromagnetic force; It is made up of a configuration, including.

In addition, in the table-type NC milling machine according to the present invention, the XY-axis stage is fixedly mounted on the base and has a Y-axis movement guide formed with a Y-axis guide rail at the center of its upper surface, and an upper side of the Y-axis movement guide. It is possible to move in the Y-axis direction while being located in the center of the upper surface of the X-axis movement guide formed with an X-axis movement guide rail, and the X-axis movement between the Y-axis movement guide and the X-axis movement guide Y-axis movement linear motor is formed to provide a feed force for the guide can be moved in the Y-axis direction, and provides a feed force to move the table in the X-axis direction between the X-axis movement guide and the table It may be made of a configuration including a linear motor moving in the X-axis direction to be formed.

In addition, in the table-type NC milling machine according to the present invention, one side of the Y-axis movement guide and one side of the X-axis movement guide are each formed with a scaler having a grid, and on a fixed side facing each scaler. The X-axis direction control encoder and the Y-axis direction control encoder for measuring the movement state of the stage may be formed.

In addition, in the table-type NC milling machine according to the present invention, one side of the Z-axis stage stage has a structure in which a Z-axis movement linear motor is formed so that a feed force can be applied to a spindle holder moved along the Z-axis movement guide rail. It can be done with.

In addition, in the table-type NC milling machine according to the present invention, a Z-axis linear encoder for measuring the movement state of the spindle holder may be formed in the Z-axis stage on one side of the Z-axis moving linear motor.

In addition, in the table-type NC milling machine according to the present invention to one side surface of the Z-axis stage to compensate the weight of the conveying body in the vertical direction in the process of the spindle holder is moved by the drive of the Z-axis moving linear motor The air cylinder for that can be formed.

In addition, the workpiece chuck in the table-type NC milling machine according to the present invention can be made of a replaceable structure with a vacuum chuck formed with a suction hole for applying a vacuum pressure to the workpiece.

In addition, in the table-type NC milling machine according to the present invention, an air bearing may be formed between the inner surface of the Z-axis stage and the outer surface of the spindle holder.

In addition, in the table-type NC milling machine according to the present invention, the column may be formed into a structure that is formed by separating the upper body and the lower body and then integrated by the fastening means.

In addition, in the table-type NC milling machine according to the present invention, the base cover may be formed on the upper portion of the base to cover a portion in which the section in which the XY axis stage is moved is excluded.

The present invention constitutes a table-type NC milling machine by being configured to be driven by electromagnetic force and pneumatic pressure by a linear motor and an air bearing instead of an electric motor or the like as the moving means and the rotating means of each component constituting the table-type NC milling machine. Not only is it possible to greatly reduce the size of each part, but the user can easily move the position of the table-type NC milling machine as needed, and there is a great advantage that the energy required for driving can be greatly saved.

In addition, the table-type NC milling machine formed by the present invention has the advantage that the position movement of the tool and the workpiece can be more precisely controlled to perform more precise machining when precise machining is required for the small workpiece. will be.

In particular, in the NC milling machine according to the present invention, since the Z axis stage is located at the upper center of the table, not only the error in the process of operating the spindle and the tool but also the mechanical rigidity can be improved. will be.

Hereinafter, with reference to the accompanying drawings, preferred embodiments according to the configuration and operation of the table-type NC milling machine according to the present invention will be described in detail.

1 is a perspective view of a table-type NC milling machine formed by the present invention, Figure 2 is a front view of a table-type NC milling machine according to the invention, Figure 3 is a side view of a table-type NC milling machine according to the invention, 4 is an exploded perspective view of a column according to the present invention, FIGS. 5A and 5B are a plan view and a bottom perspective view of a Z axis stage formed by the present invention, and FIG. 6 is an exploded view for explaining the XY axis stage according to the present invention. 7 is a perspective view illustrating a structure of a work piece chuck of a table-type NC milling machine according to an embodiment of the present invention, and FIG. 8 illustrates a structure of an air bearing applied to the table-type NC milling machine according to the present invention. 9 is a view illustrating another embodiment of the table-type NC milling machine according to the present invention.

Reference numeral 100 denoted in the drawings indicates a table-type NC milling machine constructed by the present invention, the table-type NC milling machine 100 is not only able to precisely process small workpieces, but also the processing thereof. To reduce the overall size of the mechanism for the user is easy to move the position is formed. That is, the base 120 is formed in a plate shape in order to support the body of the table-type NC milling machine 100 and to keep the table 300 in a horizontal stable state. And the weight is made on both sides of the handle 122 is formed as shown in the figure.

And the lower end is supported on one side of the upper surface of the table 300 and the upper end is formed of a column 200 bent toward the center portion of the table 300, the top of the column 200 to apply a rotational force to the tool Not only the spindle 600 is formed, but also the Z-axis stage 500 is formed so that the spindle 600 is movable in the vertical direction (Z-axis direction).

As shown in FIGS. 1 and 4, the column 200 may be formed into a structure in which the column 200 is separated into an upper body 210 and a lower body 220 and then integrated with a bolt 230. As shown in FIG. 4, the flange 212 for assembling with the lower body 220 and the flange 214 for assembling with the Z-axis stage 500 are perpendicular to each other in the upper body 210 of the column. It is formed on the upper and lower sides, respectively, fastening holes (212a, 214a) for fastening the bolts are formed in each flange. The lower body 220 is formed in a trapezoidal shape to ensure stability, the lower side is formed with a flange 222 to be fixedly mounted on the base 120, such as bolts and the upper side with the upper body 210 A fastening hole 224 for assembly is formed. In particular, as shown in Figure 4, the inner side of the lower body 220 by the weight hole 226 is to be configured so that the weight of the table-type NC milling machine 100 can be reduced.

The Z-axis stage 500 has a shandong pupil 510 of the form vertically penetrated therein as shown in the figure, the shandong pupil 510 is rectangular in plan view as shown in the figure. It is formed to achieve. In particular, any one side of the Z-axis stage 500 has a structure in which the Z-axis movement guide rail 512 is in communication with the Shanghai movement space 510, the Z-axis movement guide rail 512 is Shanghai In order to guide the spindle holder 620 to be accommodated inside the space 510 to be moved up and down with the spindle 600. To this end, one side of the spindle holder 620 is a projection piece 622 to be fitted to the Z-axis movement guide rail 512 in the process of assembling the spindle holder 620 into the Shanghai moving space 510 in the vertical direction It is formed long.

On the other hand, the upper and lower sides of the spindle holder 620 between the protruding piece 622 protruding to one side of the spindle holder 620 and one side of the Z-axis stage 500 where the Z-axis moving guide rail 512 is located. A Z-axis movement linear motor 520 for controlling the directional movement is formed. Z-axis moving linear motor 520 is a permanent magnet 522 is attached to the inside of the stator core 521 attached to the Z-axis stage 500, which is a fixed body, as shown in the figure, the spindle holder ( The protrusion piece 622 of 620 is applicable to the winding coil 513 is attached to the form. In particular, as shown in the drawings for explaining an embodiment of the present invention, the stator core 521 is formed in a planar shape of the 'c' shape, the coil 513 may be in a state accommodated therein. . On the other hand, the Z-axis moving linear motor 520 of the type shown in the drawings for explaining an embodiment of the present invention is one of the products on the market, permanently when the current is applied to the coil 513 The principle of changing the direction of the applied force in accordance with the direction of the electromagnetic force generated by the magnet 512 and the current flowing through the coil is used.

Z-axis movement The spindle holder 620 and the inner surface of the Z-axis stage 500 in the process of moving the spindle holder 620 vertically in the moving space 510 by the drive of the linear motor 520. An air bearing 700 is formed between the inner surface of the Z-axis stage 500 and the outer surface of the spindle holder 520 so that the outer surface of the surface is in contact with each other without friction. The air bearing 700 provides a pneumatic pressure in a space in which the surface of the stationary body and the surface of the mobile body face each other to allow the movable body to move in a state where the stationary body and the mobile body are spaced apart from each other.

In addition, a linear encoder 530 for measuring the vertical movement state of the spindle holder 620 is fixedly mounted on the Z-axis stage 500 on one side of the Z-axis moving linear motor 520, and the spindle holder 620 is a moving chain. A scaler 532 marked with a grid is attached to one side of the protruding piece 622.

The inside of the spindle holder 620 is formed with a cylindrical spindle mounting space 624 long in the vertical direction, the spindle 600 is integrated with the spindle holder 620 by the spindle fixture 626 and then the spindle holder 620 and Together with the spindle mounting space 624 is formed in a structure that is moved in the vertical direction. Of course, the tool chuck 610 is formed on the lower side of the spindle 600 to enable the mounting of the tool, and the tool bitten by the tool chuck 610 is formed to rotate by a rotating means provided in the spindle.

An electric motor may be applied as the rotation means of the spindle 600, but a device that allows the rotational force to be generated by electromagnetic force or pneumatic pressure may be applied as the rotation means capable of reducing the size of the spindle and enabling high-speed rotation. An example of the rotation means for generating a rotational force by electromagnetic force or pneumatic pressure is that the electromagnetic force is formed around the middle of the shaft while providing a pneumatic pressure to the impeller provided on the shaft is configured to enable high-speed rotation while the shaft is floating from the shaft hole There are things.

In particular, one side of the Z-axis stage 500 of the Z-axis movement linear motor 520 due to the weight of the spindle 600 and the spindle holder 620 in the process of moving the spindle holder 620 in the vertical direction An air cylinder 630 is formed as shown in FIG. 5B to minimize the influence on the movement by the driving force. That is, the air cylinder 630 does not provide a direct force to the vertical movement of the spindle holder 620 and the spindle 600, but by supporting the weight of the vertical conveying body itself by the pressure maintained in the cylinder constant Z Static thrust is not required due to the weight of the conveying body in the linear motor 520 for the axial movement, and the force of the linear motor 520 is used purely as the force for the Z-axis movement.

On the other hand, the table 300 which is movable in the X-axis direction (horizontal direction) and Y-axis direction (vertical direction) is formed in the position directly below the spindle 600 mentioned above. On the upper surface of the table 300, a workpiece chuck 310 is formed to enable mounting of the workpiece. The workpiece chuck may be selectively applied such as a vacuum chuck or a clamp chuck according to a method of fixing a workpiece. 7 is a plan view of the vacuum chuck 320 used as the work piece chuck as an embodiment of the present invention, in which a suction hole 322 is formed at a central portion of the vacuum chuck 320 to absorb a work piece. to be.

The XY-axis stage 400 is formed so that the table 300 can be moved in the X-axis direction or the Y-axis direction, the detailed structure of which is as shown in FIG. That is, the X-axis movement guide 410 for guiding the table 300 to be moved in the X-axis direction and the Y-axis for guiding the table 300 to be moved in the Y-axis direction below the table 300. The direction guide 420 is formed. That is, the Y-axis movement guide 420 is fixedly mounted to the base 120 while the X-axis movement guide 410 is movable in the Y-axis direction between the Y-axis movement guide 420 and the table 300. It is formed as a possible structure.

The X-axis movement guide rail 412 and the Y-axis movement guide rail 422 are formed at the centers of the operation direction of the X-axis movement guide 410 and the Y-axis movement guide 420, respectively, The X-axis direction linear motor 430 and the Y-axis direction linear motor 440 are mounted in the guide rail 412 and the Y-axis direction moving guide rail 422, respectively.

The X-axis movement linear motor 430 and the Y-axis movement linear motor 440 has a structure in which a stator core wound with a coil is mounted on the stator part and a mover core with a permanent magnet attached to the movable part. That is, the linear motor is applied using the principle that the direction of the applied force is changed according to the direction of the magnetic force generated by the permanent magnet and the direction of the current flowing through the coil. Thus, when the X-axis movement linear motor 430 and the Y-axis movement linear motor 440 is applied to enable the position movement of the table 300, the space according to the installation of the moving means for the movement of the table is greatly increased. Not only can it be reduced, but more precise control is possible.

On the other hand, the respective moving parts in the process of moving the X-axis movement guide 410 and the table 300 in a linear direction by the driving of the X-axis movement linear motor 430 and the Y-axis movement linear motor 440. Air bearings 700 are formed to allow the and the stationary parts to be in contact with each other so that they can be operated while being lifted without friction.

The air bearing 700 provides a pneumatic pressure in a space in which the surface of the stationary body and the surface of the mobile body face each other to allow the movable body to move in a state where the stationary body and the mobile body are spaced apart from each other.

In addition, scales 452 and 462 having grids are attached to one side of the X-axis movement guide 410 and one side of the Y-axis movement guide 420, and at positions corresponding to the respective scalers 452 and 462. An X-axis direction control encoder 450 and a Y-axis direction control encoder 460 are formed to read the grid position of the scaler and measure the moving distance of the moving object.

8 is a view to help understand the configuration and operation of the air bearing applied to the table-type NC milling machine according to the present invention, so that the pneumatic pressure between the fixed body 710 and the moving body 720 can be provided evenly. The air pad 730 is fixedly mounted to the fixed body 710 or the moving body 720. In order to mount the air pad 730, a plurality of grooves 740 having an air pad size are formed in the fixed body 710 or the moving body 720, and an air supply line 750 is connected to each groove 740. do. In particular, the air pad 730 may be advantageous in that the air pressure may be evenly spread when formed of a porous material.

Although the air bearing 700 is applied to the XY axis stage 400, the Z axis stage 500, the spindle 600, etc. constituting the table-type NC milling machine 100 according to the present invention, Since the configuration and operation of the air bearing means have been sufficiently described by FIG. 8, it is apparent that some of the drawings for describing an embodiment of the present invention are omitted from the illustration of the air bearing.

On the other hand, the base cover 140 is formed on the upper side of the base 120 to cover the portion except for the section in which the table 300 is moved by the XY axis stage 400 as in the embodiment shown in FIG. 9. It can be. That is, as the upper portion of the base 120 is stepped by the XY-axis stage 400, the base cover 140 is formed at the upper height of the table 300 so as to avoid various inconveniences that may occur when machining the workpiece. Will be.

The upper surface of the base cover 140 is formed with a through hole 142 to expose the upper surface of the table 300 when the base cover and the upper table of the base is covered with a base cover. The side of the base cover 140 is to be made of a shape that can substantially cover the side of the base 120 while the handle 122 is kept exposed. Therefore, a chip or the like generated during processing of the workpiece may be prevented from flowing into the inside of the XY-axis stage 400, and cleaning and the like may be easily performed after the workpiece is finished.

Hereinafter, a description will be given of the operating state of the table-type NC milling machine 10 configured as described above.

The tool chuck 610 provided at the lower side of the spindle 600 is equipped with a tool necessary for processing the workpiece, while the work piece is fixedly mounted at the work chuck 310 provided at the upper side of the table 300. do. As such, the work manager sets the origin of the tool and the workpiece while the tool and the workpiece are mounted.

Of course, the NC program according to the type of the workpiece should be prepared in the computer to which the tabletop NC milling machine 100 is connected at the stage before the actual processing is performed, and the NC controller according to the program will be the tabletop NC milling machine 100. The XY axis stage 400 and the Z axis stage 500, as well as the drive and movement of the feed means of the spindle should be prepared to be controlled.

High-speed rotation is performed by the driving force transmitted from the rotation means of the spindle 600 in the process of processing is performed by the control of the NC controller not shown, the XY axis stage 400 and the Z axis stage 500, respectively The linear motors (430, 440, 520) of the drive and the operation of the air bearing 700, the more accurate position movement is possible.

Thus, the moving means and the rotating means of each component constituting the table-type NC milling machine 100 is not only made of an electric motor, but also driven by electromagnetic force such as the linear motors 430, 440, 520 and the air bearing 700. By being configured to be precisely supported without friction, it is possible to greatly reduce the size of each part constituting the table-type NC milling machine (100). Therefore, the user can not only move the position of the table-type NC milling machine 100 as necessary, but also greatly reduce the energy required for driving the same.

In addition, since the positional movement of the tool and the workpiece can be more precisely controlled, it is possible to provide a table-type NC milling machine suitable for use when precise machining is required for a small workpiece.

As described above, the preferred embodiment according to the present invention has been described, but the present invention is not limited to the above-described embodiment, and the present invention is not limited to the above-described claims, and the present invention is not limited to the scope of the present invention. Anyone with knowledge will have the technical spirit of the present invention to the extent that various modifications can be made.

1 is a perspective view of a table-type NC milling machine formed by the present invention.

2 is a front view of the table-type NC milling machine according to the present invention.

3 is a side view of the table-type NC milling machine according to the present invention.

4 is an exploded perspective view of a column according to the present invention;

5A and 5B are a plan view and a bottom perspective view of a Z-axis stage formed by the present invention.

Figure 6 is an exploded perspective view for explaining the XY axis stage in accordance with the present invention.

7 is a view for explaining the structure of the workpiece chuck of the table-type NC milling machine according to an embodiment of the present invention.

8 is a view for explaining the structure of the air bearing applied to the table-type NC milling machine according to the present invention.

9 is a view showing another embodiment of the table-type NC milling machine according to the present invention.

※ Explanation of code for main part of drawing

100: tabletop NC milling machine 120: base

122: handle 140: base cover

200: column 210: upper body

220: lower body 226: lose weight

300: table 310: workpiece chuck

400: XY axis stage 410: X axis movement guide

412: X-axis movement guide rail 420: Y-axis movement guide

422: Y-axis movement guide rail 430: X-axis movement linear motor

440: Y axis movement linear motor 450: X axis direction control encoder

460: Y axis direction control encoder 452,462: Scaler

500: Z-axis stage 510: Shanghai East Space

512: Z-axis movement guide rail 520: Z-axis movement linear motor

530: linear encoder 532: scaler

600: spindle 610: tool chuck

620: spindle holder 622: protrusion

630: air cylinder 700: air bearing

Claims (10)

The spindle equipped with the rotationally operated tool is formed to be movable in the vertical direction (Z axis direction) while the XY axis stage in which the workpiece is mounted is movable in the horizontal direction (X axis direction) and the vertical direction (Y axis direction). In the NC milling machine is formed so that the workpiece is processed by the tool, A plate-shaped base 120 having a handle 122 for movement on the side; A column 200 having a lower end supported on one side of an upper surface of the base 120 and an upper end bent toward a central portion of the base 120; It is fixedly coupled to the upper end of the column 200 and a rectangular shandong movement space 510 is formed on the inside to guide the vertical movement of the tool, the Z-axis movement guide rail on one side of the shandong movement space 510 512 is formed and the Z-axis stage 500 is formed so that the movement of the tool is made by the electromagnetic force and the support of the air bearing; A spindle holder 620 coupled to the shank east space 510 of the Z-axis stage 500 while the spindle 600 is fixedly mounted therein; A spindle 600 fixedly mounted to the spindle holder 620 and formed at a lower end thereof so that a tool chuck 610 is formed to allow mounting of a tool, and a rotation operation is performed; A table 300 formed to enable mounting of the workpiece chuck 310 at a position directly below the spindle 600; The horizontal force (X-axis direction) and longitudinal direction (Y-axis direction) of the table 300 is formed between the base 120 and the table for the movement, but the transfer force transmitted to the table to the electromagnetic force and the support of the air bearing XY axis stage 400 formed to be made by; Tabletop NC milling machine, characterized in that configured to include. The method of claim 1, The XY-axis stage 400 is fixedly mounted to the base 120, the Y-axis direction guide guide 420 having a Y-axis direction guide rail 422 is formed in the center of the upper surface, and the Y-axis direction guide ( It is possible to move in the Y-axis direction while being located on the upper side of the 420, while the X-axis movement guide 410 and the Y-axis movement guide (410) having an X-axis movement guide rail 412 formed at the center of the upper surface thereof. A Y-axis movement linear motor 440 formed between the 420 and the X-axis movement guide 410 to provide a transfer force so that the X-axis movement guide 410 can be moved in the Y-axis direction, and An X-axis movement linear motor 430 is formed between the X-axis movement guide 410 and the table 300 to provide a transfer force so that the table 300 can be moved in the X-axis direction. Tabletop NC milling machine, characterized in that. The method of claim 2, On one side of the Y-axis movement guide 420 and one side of the X-axis movement guide 410, scalers 452 and 462 having a grid are formed, respectively, and are opposed to the respective scalers 452 and 462. Table-type NC milling machine, characterized in that the X-axis direction control encoder 450 and the Y-axis direction control encoder 460 is formed on the fixed side to measure the movement state of the X-axis direction guide 410 and the table 300. . The method of claim 1, On one side of the Z-axis stage 500 is a Z-axis movement linear motor 520 to the feed force is applied to the spindle holder 620 is moved along the Z-axis movement guide rail 512 Tabletop NC milling machine, characterized in that formed. The method of claim 4, wherein Tabletop NC milling machine, characterized in that the linear encoder 530 for measuring the movement state of the spindle holder 620 is formed in the Z-axis stage on one side of the Z-axis movement linear motor (520). The method of claim 4, wherein On one side of the Z-axis stage 500, the air cylinder for compensating the transfer weight in the vertical direction in the process of the spindle holder 620 is moved by the drive of the Z-axis movement linear motor 520 ( 630) is a table-type NC milling machine, characterized in that formed. The method of claim 1, The work piece chuck is a table-type NC milling machine, characterized in that configured to be replaced with a vacuum chuck 320 is formed with a suction hole (322) for applying a vacuum pressure to the workpiece. The method of claim 1, Tabletop NC milling machine, characterized in that the air bearing 700 is formed between the inner surface of the Z-axis stage 500 and the outer surface of the spindle holder (620). The method of claim 1, The column 200 is a tabletop NC milling machine, characterized in that the upper body 210 and the lower body 220 is formed separately after being integrated by the fastening means. The method according to any one of claims 1 to 9, Table top NC milling machine, characterized in that the base cover 140 is formed on the upper portion of the base 120 to cover the portion excluding the section in which the XY axis stage 400 is moved.

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