WO2004018149A1

WO2004018149A1 - Cnc milling machine provided with remote control panel

Info

Publication number: WO2004018149A1
Application number: PCT/KR2003/001707
Authority: WO
Inventors: Eung Gyu Jung
Original assignee: Eung Gyu Jung
Priority date: 2002-08-23
Filing date: 2003-08-23
Publication date: 2004-03-04
Also published as: AU2003253458A1; KR20020075335A

Abstract

Disclosed is a CNC milling machine provided with a remote control panel, in addition to an operating panel, the remote control panel being electrically connected to the operating panel via a connector, so that the remote control panel and operating panel are selectively used. The remote control panel includes manual and automatic operating units for manually and automatically feeding the lathe in X, Y, Z-axis directions, respectively, a switch for selecting a feeding mode of the lathe between a manual mode and an automatic mode, zero return switches, a fine adjustment knob, a feeding speed selecting handle, a re-start key for enabling re-start of a lathe feeding operation by the manual or automatic operating unit, an emergency stop button, pre and post-data calling keys, and an ON/OFF switch for controlling a rotating state of a spindle in the cutting process for the workpiece.

Description

CNC MILLING MACHINE PROVIDED WITH REMOTE CONTROL PANEL

Technical Field

The present invention relates to a CNC milling machine provided with a remote control panel, and more particularly to a CNC milling machine provided with a remote control panel for making it possible to easily conduct a series of processes adapted to cut a workpiece.

Background Art

In milling machines, X, Y, and Z-axis feeding handles are essentially provided which correspond to respective feeding directions of a table, that is, lateral, vertical, and horizontal (X, Y, Z axes) directions. Also, servo motors are provided to feed the table along the X, Y, Z axes, respectively. Thus, it is possible to feed a workpiece to a desired position. However, where a cutting process for a workpiece is carried out by manually operating the feeding handles, there are problems in that although the cutting process is simply carried out when a simple shape is machined, it is troublesome and inefficient while exhibiting a degraded accuracy when a complex inclined or circular shape is machined. This is because the operator must operate the feeding handles while identifying a machined portion of the workpiece. In accordance with development of a CNC (Computer Numerical Control) milling machine, such a problem has been solved. The CNC milling machine is equipped with an operating panel adapted to input diverse programs and to set cutting conditions, and configured to control a cutting process through a computer. By virtue of such a CNC milling machine, a complex milling process can be automatically performed.

Referring to Fig. 1, a conventional CNC milling machine is illustrated. As shown in Fig. 1, the CNC milling machine includes: a frame 14 provided with a base 12, and adapted to support a machine body including a lathe provided with a tool such as a milling cutter for machining a workpiece; a vertical feeding member 16 installed on the base 12 such that it extends vertically while being reciprocatable in a Z-axis direction (upwards and downwards) to feed the lathe in the Z- axis direction; a table member 18 installed on the vertical feeding member 16 such that it is reciprocatable in an X-axis direction (left and right) on an upper surface of the vertical feeding member 16 to feed the lathe in the X-axis direction; a horizontal feeding member 20 mounted to the frame 14 such that it is reciprocatable in a Y-axis direction (forwards and backwards) orthogonal to the reciprocating direction of the table member 18 to feed the lathe in the Y- axis direction; a key input unit 32 adapted to input various data setting values required for a process of machining the work piece, for example, a cutting process; and an operating panel 30 including the key input unit 32 along with a function operating board 34 adapted to execute manipulations required for the cutting process, for example, respective selections of the rotating speed of the milling cutter and the feeding direction and speed of a lathe, and respective selections of X, Y, and Z axes. In accordance with this configuration, the operator can set the rotating speed of the milling cutter and can operate the lathe to be fed in X, Y, and Z-axis directions by manipulating various buttons on the operating panel 30.

During the movement of the lathe in X, Y, and Z-axis directions in accordance with respective operations of associated servo motors, the operator can identify the position of the workpiece, to be machined, by referring to X, Y, and Z-axis coordinate values of the workpiece position displayed on a CRT 36.

Thus, the CNC milling machine is a machine tool which can perform not only slab or face cutting, round cutting, and diverse groove cutting, but also cutting of screws, gears, cams, etc., using diverse milling cutters each having a rotating edge. Such a CNC milling machine machines a workpiece by controlling movement of a table having certain movement ranges in vertical, horizontal and lateral directions, so as to perform both the horizontal and vertical milling processes and the machining process for forming flat, side, and inclined surfaces of the workpiece.

The operating panel 30 included in the above mentioned CNC milling machine is connected to the frame 14 by means of a connecting bracket mounted to the frame 14 by coupling means such that it is adjustable in position with respect to the frame 14. In most cases, however, the operating panel 30 cannot be arranged in front of the operator, but must be arranged at one side of the machine body. For this reason, the operator cannot monitor both the operating panel 30 and the lathe arranged on the table member 18 during a cutting process because he must be positioned in front of the lathe spaced apart from the operating panel 30 by a certain lateral distance. That is, the operator cannot concentrate his attention on both the lathe and the operating panel. As a result, there is a problem in that the milling process is inefficiently carried out. In other words, there is inconvenience in that the operator must monitor and operate the operating panel 30 and the lathe in an alternate fashion because the operating panel 30 and lathe are spaced apart from each other by a certain lateral distance.

Although the operating panel 30 can be positioned in front of the operator, there is inconvenience in this case in that the operator cannot not monitor the front portion of the lathe with his eyes because the operating panel 30 obstructs the operators' eyes due to its large size.

Disclosure of the Invention

Therefore, an object of the invention is to provide a CNC milling machine provided with a remote control panel, in addition to an operating panel, the remote control panel being electrically connected to the operating panel via a connector, so that the remote control panel and operating panel are selectively used, thereby achieving an improvement in workability.

In accordance with the present invention, this object is accomplished by providing a CNC milling machine comprising an operating panel adapted to perform a control operation for automatically feeding a lathe in X, Y, and Z-axis directions in accordance with inputted coordinate values to carry out a cutting process for a work piece mounted on the lathe, the CNC milling machine further comprising: a remote control panel detachably mounted to a front surface of the lathe while being electrically connected to the operating panel via a connector, the remote control panel including manual and automatic operating units for manually and automatically feeding the lathe in X, Y, Z-axis directions, respectively, a switch for selecting a feeding mode of the lathe between a manual mode and an automatic mode, zero return switches for returning the X, Y, and Z-axis coordinate values of the lathe to zero, respectively, a fine adjustment knob for finely adjusting accuracy of the cutting process for the workpiece to be 1/10, 1/100, or 1/000, a feeding speed selecting handle for adjusting a feeding speed of the lathe, a re-start key for enabling re-start of a lathe feeding operation by the manual or automatic operating unit, an emergency stop button for temporarily stopping the whole operation of the machine, pre and post-data calling keys for calling process data used before and after the inputting of coordinate values for feeding the lathe, respectively, and an ON/OFF switch for controlling a rotating state of a spindle in the cutting process for the workpiece.

Preferably, operation of the lathe is unconditionally stopped when an optional one of the axis selecting buttons is operated during the operation of the lathe, and the stopped operation of the lathe is re-started in accordance with an operation of the re-start key.

In accordance with the present invention, the operator can easily conduct a desired machining process through the remote control panel provided, in addition to the operating panel, at a position where the operator can conveniently conduct the machining process, while being configured to be conveniently manipulated. Thus, it is possible to achieve an improvement in workability. Brief Description of the Drawings

The above objects, and other features and advantages of the present invention will become more apparent after reading the following detailed description when taken in conjunction with the drawings, in which:

Fig. 1 is a perspective view illustrating a general CNC milling machine;

Fig. 2 is a perspective view schematically illustrating a CNC milling machine according to the present invention; Fig. 3 is an enlarged perspective view illustrating a remote control panel A shown in Fig. 2;

Fig. 4 is a block diagram of the remote control panel shown in Fig. 3;

Fig. 5 is a circuit diagram for explaining opening and closing operations of contact terminals for feeding a lathe in accordance with an automatic or manual operation carried out using the remote control panel according to the present invention; and

Fig. 6 is an enlarged view partially illustrating a feed limiting structure B of the lathe shown in Fig. 2.

Best Mode for Carrying Out the Invention

Now, preferred embodiments of the present invention will be described in detail with reference to the annexed drawings. Fig. 2 is a perspective view schematically illustrating a CNC milling machine according to the present invention. Fig. 3 is an enlarged perspective view illustrating a remote control panel A shown in Fig. 2. Fig. 4 is a block diagram of the remote control panel shown in Fig. 3. Fig. 5 is a circuit diagram for explaining opening and closing operations of contact terminals for feeding a lathe in accordance with an automatic or manual operation carried out using the remote control panel according to the present invention. In Figs. 2 to 5, respective elements corresponding to those of the conventional CNC milling machine are designated by the same reference numerals .

Referring to Fig. 2, a vertical feeding member 16, a table member 18, and a horizontal feeding member 20 are mounted to a frame 14 provided with a base 12. As shown in Fig. 4, the vertical feeding member 16, table member 18, and horizontal feeding member 20 are coupled to a main spindle motor, and an XYZ-axis driving unit 50. A milling cutter is mounted to the main spindle motor so as to perform a cutting process. The XYZ-axis driving unit 50 may comprise servo motors for feeding a lathe in X, Y, and Z-axis directions, respectively.

The XYZ-axis driving unit 50 is linked to an operating panel 30. As shown in Fig. 4, the operating panel 30 includes a CPU 10 with a CNC program stored therein and adapted to control setting data inputted from a key input unit 32 and a function operating unit 32, a mode selecting bar 42 for selectively driving the X, Y and Z axes while selecting a desired machining process, an emergency stop button 40, and a CRT 36 for allowing the operator to identify the proceeding state of the machining process. The operating panel 30 also includes one-touch type zero return switches 108 for adjusting respective coordinate values of the X, Y, and Z axes to be zero, respectively. In accordance with the present invention, a remote control panel A is also detachably mounted to the lathe at one side of the lathe. The remote control panel A is electrically connected to the operating panel 30 by means of a connector, and adapted to allow the operator to easily control the operating panel 30 at a position near the lathe during the cutting process while identifying the current state of the cutting process.

As shown in Figs. 3 and 4, the remote control panel 4 is provided with diverse function switches so as to control the feeding direction and speed of the lathe under the condition in which it is electrically connected to the operating panel 30. In the drawings, the reference numerals 102 and 104 designate manual and automatic operating units for manually and automatically feeding the lathe in X, Y, Z- axis directions, respectively. The reference numeral 106 designates a switch for selecting the feeding mode of the lathe between a manual mode and an automatic mode; 108 respective zero return switches for returning the X, Y, and Z-axis coordinate values of the lathe to zero in response to operation of a zero return operating switch 108a; 110 an ON/OFF switch for controlling the rotating state of a spindle in the cutting process for the workpiece; 112 and 113 pre and post-data calling keys for calling process data used before and after the inputting of coordinate values for feeding the lathe, respectively; 114 a fine adjustment knob for finely adjusting the accuracy of the cutting process for the workpiece to be 1/10, 1/100, or 1/000; 116 a feeding speed selecting handle for adjusting the feeding speed of the lathe; 117 a speed button for increasing the feeding speed of the lathe;, 118 an emergency stop button for temporarily stopping the whole operation of the machine; 120 a re-start key for enabling re-start of a lathe feeding operation by the manual or automatic operating unit; and 122 an auxiliary switch for re-operating the lathe stopped by a lathe feeding distance limit setting unit 130 which will be described hereinafter.

The manual operating unit 102 includes X, Y, and Z-axis selecting buttons 102a for selecting the feeding direction of the lathe, and a manual operating handle 102b for manually feeding the lathe in a selected feeding direction when the axis selecting button 102 corresponding to the selected feeding direction is in its ON state. On the other hand, the automatic operating unit 104 includes an XYZ-axis selecting lever 104a for selecting a desired feeding direction of the lathe from X, Y, and Z-axis directions, and a feeding direction switching lever 104b for automatically feeding the lathe in the axis direction selected by the axis selecting lever 104a, that is, in the lateral, horizontal or vertical direction. Meanwhile, when one of the axis selecting buttons 102a is depressed during movement of the lathe in a certain axial direction, operation of the lathe is stopped. When the manual operating handle 102b is subsequently manipulated in the depressed state of the axis selecting button 102a, the lathe is fed in the axial direction corresponding to the axis selecting button 102a.

Now, the operation of the CNC milling machine having the above described configuration according to the present invention will be described.

When it is desired to conduct a cutting process for a workpiece by the CNC milling machine, the operator first inputs various cutting conditions through the operating panel 30. Accordingly, it is possible to perform the cutting process according to the inputted cutting conditions. Meanwhile, the cutting process can also be carried out, using the remote control panel 100, by manipulating the mode selecting bar 42 on the operating panel 30 such that its terminal is shifted to a handle position.

Even in the cutting process using the remote control panel 100, it is necessary to perform, prior to the cutting process, a zero adjustment operation for the X, Y and Z axes so as to adjust respective reference points for calculation of X, Y and Z-axis coordinate values to zero. For this zero adjustment, the operator first manipulates the zero return operating switch 108a, and then depresses the X, Y, and Z- axis zero return switches 108 arranged beneath the zero return operating switch 108a. In response to the depression of the X, Y, and Z-axis zero return switches 108, the CPU 10 performs a zero adjustment operation for the X, Y, and Z axes, respectively, and displays the adjusted X, Y, and Z- axis coordinate values on the CRT 36. Although the zero return of the coordinate value for each axis is achieved in accordance with the operation of the zero return switch 108, it may also be achieved by manipulating the zero return switch 108 provided at the operating panel 30. Although not shown, the operating panel 30 may be provided with abbreviation keys for return of X, Y, and Z- axis coordinate values to zero, in addition to the zero return switches 108 for the zero return according to a mechanical operation. In this case, it is possible to achieve return of X, Y, and Z-axis coordinate values to zero in a software manner using a certain program.

After completion of the zero return, the workpiece is fed to a working position in an automatic (jog) manner or in a manual (handle) manner. That is, where the switch 106 is at its automatic mode position at which a movable terminal of the switch 106 is in contact with a jog terminal of the switch 106, it is possible to feed the lathe, by simply using the XYZ-axis selecting lever 104a and feeding direction switching lever 104b. That is, when the operator manipulates the feeding direction switching lever 104b while manipulating the axis selecting lever 104a initially positioned at a position corresponding to the X axis, thereby sequentially selecting the X, Y, and Z axes, stating from the X axis, the lathe is sequentially fed in a left or right direction along the X axis, a forward or backward direction along the Y axis, and an upward or downward direction along the Z axis. Thus, the operator can make the workpiece, to be subjected to a cutting process, reach a desired working portion. That is, when the axis selecting lever 104a of the remote control panel 100 is positioned at its X-axis position under the condition in which the X, Y, and Z terminals XI, Yl, and Zl of the operating panel 30 are connected to respective X, Y, and Z terminals X2, Y2, and Z2 of the axis selecting lever 104a, and electric power is supplied through a common power supply terminal P, to which power supply terminals PI, P2, and P3 are connected, as shown in Fig. 5, the power supply terminal PI and the terminal X2 are electrically connected, thereby causing the table member 18 to be fed in a direction corresponding to a switched position of the feeding direction switching lever 104a. When the axis selecting lever 104b is shifted to its Y-axis position, the power supply terminal P2 and the terminal Y2 are electrically connected, thereby causing the horizontal feeding member 20 to be fed. The operating unit 104 is activated for the period of time for which the axis selecting lever 104a is positioned at an optional one of its axis positions, because electric power is continuously supplied at the axis position of the axis selecting lever 104a. In other words, when the axis selecting lever 104a of the remote control panel 100 is positioned at an optional one of its X, Y, and Z-axis positions in a state of being electrically connected to the operating panel 30, it is maintained in a state of being connected to a common power supply terminal P. In this state, accordingly, it is possible to feed the lathe to a desired position simply by manipulating the feeding direction switching lever 104b.

The feeding direction switching lever 104b is switched between switching positions respectively corresponding to "+" and "-" directions. The feeding direction switching lever 104b is installed on the remote control panel 100 in an inclined state so that the operator can easily identify the feeding direction selected in accordance with a switched or shifted position of the feeding direction switching lever 104b. That is, where the feeding direction switching lever 104b is positioned at a left and downwardly inclined position, the lathe is fed in left, forward, and downward directions. On the other hand, where the feeding direction switching lever 104b is positioned at a right and upwardly inclined position, the lathe is fed in right, backward, and upward directions.

On the other hand, where it is desired to manually feed the lathe, this manual feeding can be carried out in accordance with operations of the X, Y, and Z-axis selecting buttons 102a and manual operating handle 102b provided at one side portion of the remote control panel 100. When the X-axis selecting button is depressed under the condition in which none of the X, Y, Z-axis terminals XI, X2, and X3 ^'of the X, Y, and Z-axis selecting buttons 102a is connected to the common power supply terminal P, the X-axis terminal is connected to the common power supply terminal P. In this state, the table member 18 is fed in a left or right direction when the operator turns the manual operating handle 102b in a desired direction. Similarly, when the operator depresses the Y or Z-axis selecting button, the lathe is fed in an upward or downward direction or in a forward or backward direction. The feeding of the lathe can be continued only during the depression of a selected one of the X, Y, Z-axis selecting buttons 102a. Meanwhile, when the operator depresses one of the X, Y,

Z-axis selecting buttons 102a in a state in which the lathe is fed in a certain axial direction in the automatic mode, the current operation of the lathe is stopped. For example, when the operator manipulates one of the X, Y, Z-axis selecting buttons 102a provided at the remote control panel 100 during a machining process carried out by operating the lathe in the automatic mode in accordance with cutting data inputted following a zero return operation, in order to reposition the lathe in accordance with a manual operation or to stop the operation of the lathe, the current operation of the lathe is unconditionally stopped. At this time, the spindle is maintained in its ON state. That is, only the operation of the lathe is stopped.

When it is desired to re-start the operation of the lathe from the above state, the operator depresses the axis selecting button 102a corresponding to the axis, along which the lathe is to be fed, and turns the manual operating handle 102b. In accordance with such manipulations, an associated one of the vertical feeding member 16, table member 18 and horizontal feeding member 20 is fed again. When it is desired to perform again the automatic operation after the re-positioning of the lathe according to the manual operation, or to re-start the stopped operation of the lathe, the operator depresses the re-start key 120. In response to the depression of the re-start key 120, the stopped operation, that is, the previous operation, is carried out. That is, the re-start key 120 should be operated in order to re-start the stopped operation of the lathe.

When the operator depresses the speed button 117 during the operation of the lathe, the current feeding speed is increased by a certain rate. When the speed button 117 is switched again to its OFF state, the lathe operates at an original feeding speed. Although the speed button 117 provides a function similar to the feeding speed selecting handle 116, it functions to increase the lathe feeding speed for a predetermined time, as compared to the feeding speed selecting handle 116 adapted to set a fixed lathe feeding speed.

Although the axis selecting buttons 102a are limited to the X, Y, and Z axes in the illustrated embodiment of the present invention, it may be possible to provide additional axis selecting buttons corresponding to additional axes, in order to perform a 4 or 5-dimensional cutting process (for example, a process for machining an inclined face) . For the cutting process to be carried out using the remote control panel 100, similarly to the cutting process carried out using the operating panel 30, the zero adjustment is first carried out. Thereafter, the lathe is fed to a desired position in accordance with an automatic or manual operation. For this operation, the operator can manipulate the remote control panel 100 while monitoring the lathe being fed. Accordingly, it is possible to more reliably perform the cutting process.

Although not shown, a CRT having a certain size may be mounted to a certain portion of the CNC milling machine body such that it forwardly faces the operator positioned in front of the lathe during the cutting process. In this case, the operator can easily perform the cutting process, simply using the remote control panel 100, because it is unnecessary for the operator to monitor the CRT 36 of the operating panel 30 for identification of the inputted coordinate values.

Fig. 6 is an enlarged view partially illustrating a feed limiting structure B of the lathe shown in Fig. 2. This feed limiting structure is adapted to solve a problem caused by unrestricted lateral feeding of the lathe occurring when the lathe is separated from the working position under the condition in which there is no limitation on the lateral feeding distance of the lathe.

As shown in Fig. 6, a guide groove 132 is longitudinally formed at one side surface of the table member 18 movable in the X-axis direction. At least one bracket 134 is fitted in the guide groove 132. In the illustrated case, two brackets 134 are provided which are spaced apart from each other by a desired distance. A rod 136 is fixedly mounted to each bracket 134. A switch 140 is arranged beneath the table member 18 (for example, on the horizontal feeding member 20) . The switch 140 is provided at an upper end thereof with a switch terminal 140a adapted to selectively come into contact with the rods 136 during the movement of the table member 18.

In accordance with the feed limiting structure having the above described configuration, it is possible to limit the feeding distance of the lathe within a certain range. That is, when the rod 136 of one bracket 134 comes into contact with the switch terminal 140a of the switch 140 during the movement of the table member 18 in a certain direction to feed the lathe, thereby depressing the switch terminal 140a, the operating state of the switch 140 is switched, so that the CPU 10, which may be a microprocessor, recognizes that the table member 18 has reached an end position, and thus, stops the movement of the table member 18.

The stopped feeding of the lathe is re-started in accordance with an ON state of the auxiliary switch 122. For example, when the auxiliary switch 122 is depressed, the switched state of the switch 140 by the switch terminal 140a is returned to an original state, so that the table member 18 re-operates.

Thus, when the switch 140, which is normally maintained in its OFF state, is switched to its ON state in accordance with shift of its switch terminal 140a caused by the rod 136 of one bracket 134, the microprocessor 10 senses the switched state of the switch 140, thereby stopping the feeding of the lathe. Of course, this operation is carried out only under the condition in which the switch terminal 140a is in its depressed state, that is, the switch 140 is in its ON state. Accordingly, when the operator selects an automatic or manual operation to feed the lathe after the operation of the auxiliary switch 122 carried out in the stopped state of the table member 18, the table member 18 may be driven even when it is positioned beyond its feeding distance limit range.

Although the feed limiting structure has been described as being applied only to the table member 18 by fitting the brackets 134 in the guide groove 132 formed at the table member 18 and installing the switch 140 to control the operation of the table member 18, it may also be applied to the vertical feeding member 16 and horizontal feeding member 20. Thus, it is possible to control respective operations associated with the X, Y, and Z axes. Industrial Applicability

As apparent from the above description, in accordance with the present invention, it is possible to more easily perform a cutting process in a CNC milling machine by use of a remote control panel provided at the CNC milling machine such that it is electrically connected to an operating panel equipped in the CNC milling machine via a connector.

In accordance with the present invention, a simple zero return operation can be achieved. For a zero adjustment in conventional cases using only the operating panel 30, it is necessary to select a desired axis, and then to manipulate the key input unit 32 to sequentially enter a value of "0" and input data. In accordance with the present invention, the automatic operation of the lathe can be easily stopped by operating an optional one of the axis selecting buttons. Of course, the stopped operation of the lathe can be easily restarted.

Since a feed limiting structure adapted to control movement of the lathe is provided in accordance with the present invention, it is possible to stop the operation of the lathe when the lathe moves beyond a predetermined feeding distance range in a state in which the operator is absent from the working position. Thus, a reliable cutting process can be achieved. Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims .

Claims

1. A CNC milling machine comprising an operating panel adapted to perform a control operation for automatically feeding a lathe in X, Y, and Z-axis directions in accordance with inputted coordinate values to carry out a cutting process for a work piece mounted on the lathe, the CNC milling machine further comprising: a remote control panel detachably mounted to a front surface of the lathe while being electrically connected to the operating panel via a connector, the remote control panel including manual and automatic operating units for manually and automatically feeding the lathe in X, Y, Z-axis directions, respectively, a switch for selecting a feeding mode of the lathe between a manual mode and an automatic mode, zero return switches for returning the X, Y, and Z-axis coordinate values of the lathe to zero, respectively, a fine adjustment knob for finely adjusting accuracy of the cutting process for the workpiece to be 1/10, 1/100, or 1/000, a feeding speed selecting handle for adjusting a feeding speed of the lathe, a re-start key for enabling re-start of a lathe feeding operation by the manual or automatic operating unit, an emergency stop button for temporarily stopping the whole operation of the machine, pre and post-data calling keys for calling process data used before and after the inputting of coordinate values for feeding the lathe, respectively, and an ON/OFF switch for controlling a rotating state of a spindle in the cutting process for the workpiece.

2. The CNC milling machine according to claim 1, wherein: the manual operating unit includes X, Y, and Z-axis selecting buttons for selecting a desired feeding direction of the lathe, and a manual operating handle for manually feeding the lathe in a selected feeding direction when the axis selecting button corresponding to the selected feeding direction is in its ON state; and the automatic operating unit includes an XYZ-axis selecting lever selectively positioned at one of X, Y, and Z- axis positions, thereby selecting a desired feeding direction of the lathe from X, Y, and Z-axis directions, and a feeding direction switching lever for automatically feeding the lathe in a lateral, horizontal or vertical direction corresponding to the axis position selected by the axis selecting lever.

3. The CNC milling machine according to claim 2, wherein: the manual operating unit is maintained in an activated state only for a period of time for which the X, Y, or Z-axis selecting button is in a depressed state; and the automatic operating unit is maintained in an activated state when the axis selecting lever is positioned at the X, Y, or Z-axis position.

4. The CNC milling machine according to claim 1 or 2, wherein operation of the lathe is unconditionally stopped when an optional one of the axis selecting buttons is operated during the operation of the lathe, and the stopped operation of the lathe is re-started in accordance with an operation of the re-start key.