WO2014163483A1

WO2014163483A1 - An improved computer numerically controlled gantry device and method thereof

Info

Publication number: WO2014163483A1
Application number: PCT/MY2014/000051
Authority: WO
Inventors: Mohd Hamdi ABDUL SHUKOR; Mohammed Sarhan AHMED ALY DIAA; Akbari JAVAD; Noor Azizi MARDI; Movahhedy MOHAMMAD REZA; Besharati SEYED REZA; Abdul Hadi JALALUDIN
Original assignee: Universiti Malaya
Current assignee: Universiti Malaya
Priority date: 2013-04-04
Filing date: 2014-04-03
Publication date: 2014-10-09
Anticipated expiration: 2015-10-04

Abstract

The present invention relates to an improved computer numerically controlled (CNC) gantry device for material processing comprising five axes of movement and rotation, and to method thereof. The computer numerically controlled device comprises a gantry assembly (100) attached to a column end support (100a); a vertical milling head (101 ); a workpiece table (102); and a base assembly (103) means for supporting the gantry assembly (100) and the workpiece table (102). The method of machining a workpiece includes the steps of causing a gantry assembly (100) to move in a direction opposite to a direction in which the workpiece table (102) moves, and travels with respect to a horizontal X coordinate axis at a distance less than a half of length of the workpiece.

Description

AN IMPROVED COMPUTER NUMERICALLY CONTROLLED GANTRY DEVICE

AND METHOD THEREOF

FIELD OF THE INVENTION

The present invention relates to a computer numerically control (CNC) device. More particularly, the present invention relates to an improved computer numerically controlled (CNC) device for material processing comprising five axes of movement and rotation, and to method thereof.

BACKGROUND OF THE INVENTION

Precision motion control is crucial and required in many industries nowadays. Advent of computer numerically controlled devices or machines are widely used today in nearly all aspects of manufacturing. An improved automation of the devices assists to reduce the amount of operator intervention related to fabrication of workpieces. In the precision control, degree of rigidity and amount of table travel in the X, Y, and Z planes are important considerations in most applications.

Computer numerically controlled devices are automated milling devices that make industrial components without direct human assistances. Coded instructions from a computer allow the machines to fabricate workpieces or parts accurately and precisely. The computer numerically controlled machines may include milling machines, lathes and grinders. It is known in the art that the milling machines cut materials using a cutting spindle which is moveable to many positions and depths as instructed in the coded instructions generated by the computer. Lathes use automated tools that spin to shape the material. Grinders, on the hand, use a spinning wheel to grind down the materials, and thus mold metal or plastic into the desired shape.

Traditionally, a computer numerically controlled device includes a base with horizontal rails and intermediate members, that supports a horizontal table on which a workpiece is disposed. The base and components it supports are fixed. Normally, the size of the workpiece is limited by the size of the base. The larger the workpiece, a correspondingly large base is required. As mentioned earlier, movements of the computer numerically controlled device is controlled by parts or cutting files generated by computer aided design (CAD) software and computer aided manufacturing technology. Basically, the cutting file directs the device through a series of steps. The instructions direct the system with respect to where the workpiece is to be cut and in what order the cuts are to be made.

U.S. Patent No. 8,328,172 B2 describes a computer numerically controlled (CNC) system including a travelling drive bar assembly for support of material to be processed. The CNC system in the publication comprises a base assembly, a stationary gantry assembly, a carriage assembly, an elongated travelling component, two pairs of guide wheels, a structural guide element, and a pinion. The stationary gantry assembly is mounted to the base assembly at the side members. However, the above CNC system is restricted to only movements at the carriage assembly with respect to the vertical axis and horizontal axis, and at the elongated travelling component which linearly moves with respect to the horizontal axis.

Accordingly, what is needed is an improved computer numerically controlled (CNC) device for use in machining a workpiece. Particularly, it is preferred if the improved CNC system comprises a table and a gantry assembly that are configured to move simultaneously with respect to their respective axis upon operation. With such configuration, the table and/or the gantry assembly travel at a distance less than a half of length of the workpiece. It would be advantageous if the improved CNC system is a five-axis machining system.

Although the teachings of the prior art disclose many computer numerically controlled systems for material processing, none specifically relates to an improved CNC system as claimed in the present invention. Therefore, there exists a need for the aforementioned features of the present invention.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.

A primary object of the present invention is to provide a computer numerically controlled device for use in machining a workpiece. The computer numerically controlled device, or CNC, is defined as the device that is programmed and controlled through a computer that offers very short set up times and flexibility to run batches from one to several thousand. The CNC is widely used in manufacturing sector that includes drilling, milling, reaming, boring and counter boring.

In accordance with one embodiment of the present invention, the computer numerically controlled device comprises a gantry assembly attached to a column end support and configured for a linear movement with respect to a horizontal X coordinate axis; a vertical milling head displaceably guided in a horizontal Y coordinate axis and in a vertical Z coordinate axis; a workpiece table slidably fixed to move with respect to the horizontal X coordinate axis parallel to the gantry assembly; and a base assembly means for supporting the gantry assembly and the workpiece table. The vertical milling head comprises a vertical carrier; and a machining unit rotatably fixed to the vertical carrier for a rotation with respect to the vertical Z coordinate axis. In accordance with another embodiment of the present invention, the gantry assembly is configured to move in a direction opposite to a direction in which the workpiece table moves. It is preferred that the gantry assembly travels with respect to the horizontal X coordinate axis at a distance less than a half of length of a workpiece. It is more preferred that the workpiece table travels with respect to the horizontal X coordinate axis at a distance less than a half of length of a workpiece. It is most preferred that the gantry assembly, the vertical milling head, and the workpiece table are simultaneously being conducted by a computer control system. The workpiece table is guided by fourth parallel rails deployed on the base assembly, wherein the base assembly comprises a table feed drive and a Y coordinate axis feed drive. In accordance with yet another embodiment of the present invention, the gantry assembly comprises a Y coordinate axis feed drive, first parallel rails mounted on a horizontal bar where the vertical milling head is guided. Preferably, the gantry assembly attached to the column end support is guided by second parallel rails for the linear movement with respect to the horizontal X coordinate axis. The vertical milling head comprises a Z coordinate axis feed drive.

Preferably, the vertical milling head comprises third parallel rails vertically mounted on the vertical carrier where the machining unit is guided. More preferably, the vertical milling head comprises a spindle and a motorized chuck. In accordance with another aspect of the present invention, a method of machining a workpiece, using a computer numerically controlled device is described. Preferably, the method includes the steps to cause a workpiece table to move with respect to a horizontal X coordinate axis; to cause a gantry assembly to move with respect to the horizontal X coordinate axis wherein, the gantry assembly being moved in a direction opposite to a direction in which the workpiece table moves; to cause a vertical milling head to move with respect to a horizontal Y coordinate axis and a vertical Z coordinate axis; and to provide a machining unit for a rotation with respect to the vertical Z coordinate axis. It is an advantage of the present invention to provide an improved computer numerically device comprises a workpiece table and/or a gantry assembly that travel at a distance less than a half of length of a workpiece. It is preferred that the total physical size dimension of the device is at minimal and reduced compared to prior art.

It is another advantage of the present invention to improve efficiency of the computer numerically controlled device. It would be advantageous that the computer numerically controlled device provides high speed machining operation. It would be more advantageous that, in the present invention, the gantry assembly, the vertical milling head, and the workpiece table are simultaneously being conducted by a computer control system

It is yet another advantage of the present invention to provide a computer numerically controlled device and method thereof that is simple and space efficient. Furthermore, the device of present invention is relatively simple to manufacture, easy to install and use, and comparatively cost efficient.

It is an additional advantage of the present invention that is capable to be used in both machining and robotics areas. Preferably, the present invention is relatively light but relatively rigid, and mobile and portable, and easily serviceable by a user. The foregoing and other objects, features, aspects and advantages of the present invention will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendant advantages thereof will be readily as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

Figure 1 is a series of diagrams showing a computer numerically controlled device at different orthographic views according to one embodiment of the present invention, wherein Figure 1a is perspective view; Figure 1 b is side view; Figure 1c is back view; and Figure 1 d is plan view;

Figure 2 shows a gantry assembly which is a part of the computer numerically controlled device according to the present invention; and Figure 3 shows a base assembly of the computer numerically controlled device according to the present invention. It is noted that the drawings may not be to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numberings represent like elements between the drawings.

DETAILED DESCRIPTION OF THE INVENTION

In the following description of the preferred embodiment, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration a specific embodiment in which the present invention may practised. It is to be understood that other embodiments may be utilized and structurel changes may be made without departing from the scope of the present invention.

A five-axis computer numerically controlled device is a device which permits some parts to move or travel linearly with respect to mutually orthogonal X, Y, and Z coordinate axes of a Cartesian coordinate system. It is noted that the X coordinate axis may be considered to be horizontal and extend along the longitudinal axis of the system; Y coordinate axis is horizontal, perpendicular to the X coordinate axis, and across the longitudinal axis of the system; and Z coordinate axis is vertical. The five-axis computer numerically controlled device as described herein allows movement of a workpiece table 102 in a direction opposite to a direction in which a gantry assembly 100 moves, and also it allows a machining unit 101b to rotate about a rotary axis or a vertical axis.

In one preferred embodiment, the present invention describes a computer numerically controlled device for use in machining a workpiece. The computer numerically controlled device is schematically described herein as shown via orthographic views in Figure 1. The present invention can be clearly seen and understood by way of, Figure 1a which shows a perspective view; Figure 1 b which shows a side view; Figure 1c which shows a back view; and Figure 1d which shows a plan view of the computer numerically controlled device. Figure 2 envisages another perspective view of a vertical milling head 101 that is fixed to a gantry assembly 100, without having a workpiece table 102 and a base assembly 103 in the figure. Figure 3, on the other hand, describes the workpiece table 102 mounted on the base assembly 103 without the gantry assembly 100 and the vertical milling head 101 being shown. As shown in Figure 1a, the computer numerically controlled device comprises a gantry assembly 100, a vertical milling head 101 , a workpiece table 102, and a base assembly 103. The gantry assembly 100 comprises a horizontal bar 100d. The horizontal bar 100 is connected to a leg on the sides so as to form the gantry assembly 100. The gantry assembly 100 comprises first parallel rails 100c which is mounted on the horizontal bar 100 where the vertical milling head 101 is guided. The gantry assembly 100 is attached to a column end support 100a and with such arrangement the gantry assembly 100 is configured to move linearly with respect to a horizontal X coordinate axis. The gantry assembly 100 attached to the column end support 100a is guided by second parallel rails 100e for the linear movement with respect to the horizontal X coordinate axis. The gantry assembly 100 further comprises a Y coordinate axis feed drive 100b. The Y coordinate axis feed drive 100b is adapted to assist movement of the vertical milling head 101. Preferably, the vertical milling head 101 is mounted to the horizontal bar 100d of the gantry assembly 100.

The vertical milling head 101 is displaceably guided in a horizontal Y coordinate axis and in a vertical Z coordinate axis of the computer numerically controlled device. The vertical milling head 101 comprises a vertical carrier 101a; and a machining unit 101b. The machining unit 101b is rotatably fixed to the vertical carrier 101a for a rotation with respect to the vertical Z coordinate axis. A connector (not shown) is employed so as to engage the machining unit 101b to the vertical carrier 101a. Preferably, the connector is attachable to the vertical carrier 101a by way of fixing third parallel rails 101d onto the vertical milling head 101. The third parallel rails 101d is vertically mounted on the vertical carrier 101a where the machining unit 101b is guided. To assist vertical movement of the machining unit 101b with respect to the vertical Z coordinate axis, a Z coordinate axis feed drive 101c is deployed on top of the vertical milling head 101. The vertical milling head 101 may comprises, but not limited to, a spindle, a motorized chuck and the like. The workpiece table 102 is engaged to the base assembly 103. The workpiece assembly 102 is configured to move or slide with respect to the horizontal X coordinate axis, parallel to the gantry assembly 100. The movement or slide of the workpiece table 102 is being guided by fourth parallel rails 102a. The fourth parallel rails 102a is deployed on the base assembly 103. A table feed drive 103a is adapted to drive the movement of the workpiece table 102, which is directly connected to the fourth parallel rails 102a. The workpiece may include, but not limited to, woods, plastics, and metals. It is understood that a method to hold the workpiece down on the workpiece table 102 may be as selected by one of ordinary skill in the art, such as clamping, bolting, and the like. For example, a vice is utilized to hold a workpiece to be cut or shaped.

The base assembly 103 is fixed to the gantry assembly 100 and the workpiece table 102. The base assembly 103 is mean for supporting the gantry assembly 100 and the workpiece table 102 so as to prevent distractions or interruptions or like events related to the vibration to the computer numerically controlled device upon operational. Preferably, the base assembly 103 is secured to its positions and to other parts of the device by bolts. The base assembly 103 comprises a X coordinate axis feed drive 103b.

In another preferred embodiment, the gantry assembly 100 of the computer numerically controlled device is configured to move in a direction opposite to a direction in which the workpiece table 102 moves. The gantry assembly 100 travels with respect to the horizontal X coordinate axis at a distance less than a half of length of a workpiece. Alternatively, the computer numerically controlled device is functional by way of casuing the workpiece table 102 to travel with respect to the horizontal X coordinate axis at a distance less than a half of length of a workpiece. Preferably, the gantry assembly 100, the vertical milling head 101 , and the workpiece table 102 are simultaneously being conducted by a computer control system (not shown). More preferably, the gantry assembly 100, the vertical milling head 101 , and the workpiece table 102 are independent and controllable by individual feed drives including, but not limited to, an integrated computer control system. More preferably, the computer control system comprises G code as a medium for communication between the computer numerically control device and a user. The G code may be generated by using a computer aided manufacturing (CAM) program.

The computer numerically controlled device further comprises a linear screw, linear bearing and guiding bar. The linear screw is adapted to assist movement parts of the device (as the abovementioned) on their respective parallel rails. The computer numerically controlled device can comprise a pinion, a steering shaft, and a rack, or ball screws. The pinion engages teeth on a linear bar or the rack, and causes the rack to move to the side, up to the limit of its travel. The ball screws comprise a mechanical linear actuator that translates rotational motion to linear motion, and a threaded shaft provides a helical raceway for ball bearings which act as a precision screw. A coolant such as mist coolant and flood coolant may be provided in the present invention. In accordance with another aspect of the present invention, a method of machining a workpiece, using a computer numerically controlled device is described. The method comprising the steps of:

(i) providing the workpiece onto a workpiece table 102; causing the workpiece table 102 to move with respect to a horizontal X coordinate axis;

(iii) causing a gantry assembly 100 to move with respect to the horizontal X coordinate axis wherein, the gantry assembly 100 being moved in a direction opposite to a direction in which the workpiece table 102 moves;

(iv) causing a vertical milling head 101 to move with respect to a horizontal Y coordinate axis and a vertical Z coordinate axis via a vertical carrier 101a;

(v) providing a machining unit 101b for a rotation with respect to the vertical Z coordinate axis; and (vi) discharging the workpiece from the workpiece table 102 upon completion.

The method of machining the workpiece is configured to a surprising effect of the present invention such that the gantry assembly 100 and/or the workpiece table 102 travels with respect to a horizontal X coordinate axis at a distance less than a half of length of the workpiece. Consequently, a feed stroke length is dramatically reduced as compared to the conventional similar devices. While this invention has been particularly shown and described with reference to the exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims

A computer numerically controlled device for use in machining a workpiece, characterized in that, the computer numerically controlled device comprising: a gantry assembly (100) attached to a column end support (100a) and configured for a linear movement with respect to a horizontal X coordinate axis;

a vertical milling head (101 ) displaceably guided in a horizontal Y coordinate axis and in a vertical Z coordinate axis, comprising:

a vertical carrier (101a); and

a machining unit (101 b) rotatably fixed to the vertical carrier (101a) for a rotation with respect to the vertical Z coordinate axis;

a workpiece table (102) slidably fixed to move with respect to the horizontal X coordinate axis parallel to the gantry assembly (100); and a base assembly (103) means for supporting the gantry assembly (100) and the workpiece table (102).

A computer numerically controlled device according to Claim 1 , wherein the gantry assembly (100) is configured to move in a direction opposite to a direction in which the workpiece table (102) moves.

A computer numerically controlled device according to Claim 1 , wherein the gantry assembly (!OO) travels with respect to the horizontal X coordinate axis at a distance less than a half of length of the workpiece.

A computer numerically controlled device according to Claim 1 , wherein the workpiece table (102) travels with respect to the horizontal X coordinate axis at a distance less than a half of length of the workpiece.

A computer numerically controlled device according to Claim 1 , wherein the gantry assembly (100), the vertical milling head (101 ), and the workpiece table (102) are simultaneously being conducted by a computer control system.

6. A computer numerically controlled device according to Claim 1 , wherein the gantry assembly (100) comprises a Y coordinate axis feed drive (100b).

7. A computer numerically controlled device according to Claim 1 , wherein the gantry assembly (100) comprises first parallel rails (100c) mounted on a horizontal bar (100d) where the vertical milling head (101 ) is guided.

8. A computer numerically controlled device according to Claim 1 , wherein the gantry assembly (100) attached to the column end support (100a) is guided by second parallel rails (100e) for the linear movement with respect to the horizontal X coordinate axis.

9. A computer numerically controlled device according to Claim 1 , wherein the vertical milling head (101 ) comprises a Z coordinate axis feed drive (101c).

10. A computer numerically controlled device according to Claim 1 , wherein the vertical milling head (101 ) comprises third parallel rails (101d) vertically mounted on the vertical carrier (101a) where the machining unit (101b) is guided.

11. A computer numerically controlled device according to Claim 1 , wherein the vertical milling head (101 ) comprises a spindle.

12. A computer numerically controlled device according to Claim 1 , wherein the vertical milling head (101 ) comprises a chuck.

13. A computer numerically controlled device according to Claim 1 , wherein movement of the workpiece table (102) is guided by fourth parallel rails (102a) deployed on the base assembly (103).

14. A computer numerically controlled device according to Claim 1 , wherein the base assembly (103) comprises a table feed drive (103a).

15. A computer numerically controlled device according to Claim 1 , wherein the base assembly (103) comprises a X coordinate axis feed drive (103b).

16. A method of machining a workpiece, using a computer numerically controlled device, characterized in that, the method comprising the steps of:

providing the workpiece onto a workpiece table (102);

causing the workpiece table (102) to move with respect to a horizontal X coordinate axis;

causing a gantry assembly (100) to move with respect to the horizontal X coordinate axis wherein, the gantry assembly (100) being moved in a direction opposite to a direction in which the workpiece table (102) moves; causing a vertical milling head (101 ) to move with respect to a horizontal Y coordinate axis and a vertical Z coordinate axis via a vertical carrier (101a);

providing a machining unit (101 b) for a rotation with respect to the vertical Z coordinate axis; and

discharging the workpiece from the workpiece table (102) upon completion.