Title of Invention

COMPACT HIGH-SPEED HORIZONTAL MACHINING CENTRE

Abstract

This invention relates to a compact, horizontal, high-speed horizontal machining center with a unique configuration of top mounted tool magazine and high productivity features. The radial arrangement of the tools on the tool magazine and the chip disposal system at the rear end of the machine account to compactness and easy maintenance of the machine. The high speed spindle and speedy automatic tool changer result in faster operation of the machining center and enable operation of multiple machines by single operator.

Full Text

FIELD OF THE INVENTION This invention relates to a compact, horizontal, high-speed production center. This production center is a horizontal machining center with a unique configuration of top mounted tool magazine and high productivity features. BACKGROUND Demand for compact machine modules with vertical and horizontal configuration machining center with better productivity features such as high spindle speeds, higher rapid traverse rates and faster tool change is increasing in manufacturing sectors for smaller components of the auto sector. There is increasing focus on using these machine modules for a line manufacturing set up, where multiple machines are operated by a single operator. Further, this also reduces the floor space requirements. DISCUSSION OF PRIOR ART U,S patent 5,927,463 discloses a vertical machining center with a vertical pallet capable of clamping a horizontal pallet. U.S. Patent 5,885,199 talks about a compact machining center for multifunction, having to do with a metal cutting machine tool. Both of these inventions do no have the re-arrangement of the ATC atop the machining center and other features to ensure compactness, that are a part of this invention. There are a variety of horizontal, high-speed production centers are available in the market. However, the need for a high-speed production center with better productivity features and faster tool change is not yet available. SUMMARY OF THE INVENTION It is the primary object of the present invention to develop a Compact, Horizontal, High-Speed Production Center with automatic tool changer (ATC), which occupies minimum space without sacrificing the faster tool change by the use of a twin arm ATC. The machine is designed optimally for minimum width keeping enough space for maintenance. In the proposed system, all the elements and sub-systems are moimted on the machine to facilitate lifting of the machine as a single unit. The following are the further features of the present invention: • Development of high speed ATC for mounting on top of the column to limit the width of the machine i.e. the machine width is defined by the table size and the strokes of table in X-axis. • • Use of a fixed column and moving table concept for the Horizontal Machining Center to house the ATC on the column for simplicity, compactness and economy. Elimination of sequential operations in tool change cycle to make all the operations execute simultaneously, such as ATC door open/close, spindle orientation, vertical slide movement, keeping ready the next tool in the magazine for tool change. Elimination of extra slide movement by positioning the spindle slide in one go to the tool change position without any need to wait for door open signals, enabling parallel operations instead of sequential operations. Single life machine feature with all elements and sub-systems moimted on the machine. The machine without APC can be operated from the front and there is no necessity for approach from side of the machine enabling installation of machines side by side with minimum gap between machines. The coolant system behind the machine is accommodated within the width of the machine with provision for chip management at the rear. • Electrical cabinet mounted at the back of the machine. • World class guarding concept for aesthetics and ergonomics. In order to maintain compactness, these subsystems are innovatively arranged such that machine width is maintained within 1600 mm for this size of machine with telescopic cover protection for all axes. This is possible due to newly developed top mounted special twin arm 20/30 tools ATC. The tools are arranged radially on the tool magazine. This unique arrangement eliminates tool pot tilting, normally required for the tool change operation. In order to maintain compactness, the chip disposal tank is interfaced with the machine at the rear end. The machine is provided with a world class guarding concept for aesthetics and ergonomics. The machine is designed optimally for minimum width keeping enough space for maintenance. Majority of elements and subsystems are mounted on the machine to facilitate lifting the machine as single unit and reducing machine installation time. Advantages of this machine: The compact high speed horizontal machining center with high productivity features provides the required advantage for a lean manufacturing solution wherein single operator can handle multiple machines. This is possible due to compact design and also feasibility of machines arrangements with minimum space between them. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 illustrates the top-view of the known standard Horizontal Machining Center; Fig.2 illustrates the side-view from the side marked "A" in Fig. 1 of the known standard Horizontal Machining Center and hereinafter it will be referred to as 'View A'; Fig.3 illustrates the side-view from the side marked "B" in Fig. 1 of the known standard Horizontal Machining Center and hereinafter it will be referred to as 'View B'; Fig.4 illustrates the top-view of the compact, horizontal, high-speed production center of the present invention; Fig.5 illustrates view from the side marked "C" in Fig. 4 of the compact, high-speed Production Center of the present invention and hereinafter it will be referred to as 'ViewC; Fig.6 illustrates view from the side marked "D" in Fig. 4 of the compact, high-speed Production Center of the present invention and hereinafter it will be referred to as 'View D'; DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS Figures 1, 2 and 3 illustrate the known Standard Horizontal Machining Centers that are available with twin arm ATC and tool magazine mounted on the side of the column. These machines consist of the following subsystems: • A machine bed, shown in Fig. 1, part 1 with a fixed column, shown in Fig. 1, part 2. • A vertical slide, shown in Fig. 2, part 3. • A spindle cartridge, shown in Fig. 2, part 4. • A table, shown in Fig. 2, part 5 that is capable of moving in two horizontal axes. This table also has an indexing facility or with NC rotary axis. • An automatic pallet changer system, shown in Fig. 2, part 6. • A tool magazine, shown in Fig. 2, part 7, that is mounted on the side of the machine. Tools are exchanged using twin arm ATC. Tools are prepared for exchange either by tool pot tilting, shown in Fig. 3, part 13. • A coolant system, shown in Fig. 1, part 8 which can be planned either on front or rear with chip conveyor running across the machine. A guard, shown in Fig. 1, part 9, is also provided. • An operator panel, shown in Fig. 3, part 10, on the right side of the machine. • Electrical cabinets, shown in Fig. 3, part 11, mounted on the side of the machine. The compact high-speed horizontal production center of the present invention, is designed keeping in view of market requirement of compact machine with width of 1600 mm. This preferred embodiment is depicted in figures 4, 5 and 6. This machine is developed with following subsystems: • A machine bed, shown in Fig. 4, part 12, with a fixed column concept, shown in Fig. 5, part 13. • A vertical side, shown in Fig. 5, part 14, with # 40 taper spindle cartridge, shown in Fig. 5, part 15, having a spindle speed of 10000 RPM. Optionally spindles are also available with HSK A 63 taper. • A table that is capable of moving in two axes, shown in Fig. 5, part 16. This table is provided with an indexing facility - 360 positions at every 1-degree. Optionally, an NC rotary table is also available. A palletized version is also available for machine with automatic pallet changer system. • An optional pallet changer system, shown in Fig. 5, part 17. The loading station is provided with manual indexing facility of 4 positions at every 90° with locking facility. • A tool magazine, shown in Fig. 4, part 18, with twin arms, that is mounted on the top of the column. No pot tilting arrangement is required for tool exchange as the tool axis is parallel to spindle at tool change position, shown in Fig. 5, part 23. Twin arm exchanges the tool with tool change time of 1.5 sec. ATC handles tools of 075 / 025 mm, 200 mm long and tool weight of 4 kg. Tool magazine is available with 20 or 30 tool capacity. • A coolant system, shown in Fig. 6, part 19, planned on the rear side of the machine with chip conveyor running along the depth of the machine. A guard, shown in fig. 5, part no. 20, which is designed with world class guarding concept for aesthetics and ergonomics. • An operator panel, shown in Fig. 4, part 21, on the right side of the machine. • An electrical cabinet, shown in Fig, 5, part 22, that is mounted on the rear of the machine. The machine has a three axes servo system with traverses of 450x350x400 mm in X/Y/Z axes and a rapid traverse rate of 48 m/min and 0.7G acceleration. All axes are protected by telescopic covers. Machine construction of the CHPC 32H The machine CHPC 32H consists of the following parts: • Main Machine • CNC system • Electrical cabinet • Chip conveyor & Coolant system • Pneumatic system • Hydraulic system Main Machine The following are the details of various units mounted on the machine: Machine Bed The machine is a sturdy box type, well-ribbed, welded structure, which is stress relieved to maintain the machine accuracy for years. This machine has been designed keeping in mind the efficient disposal of chips with effective coolant flushing. Total leak-proofhess is achieved by providing integral chute around the bed, which supports the guard. Column is fixed on top of the bed and Electrical cabinet mounting bracket is fixed at the rear side of the bed. Cross Slide This structure is made of high grade Cast Iron with well-ribbed casting and is stress relieved. This unit moves on L.M. Guide ways of the bed and is driven by a servomotor through a high accuracy ball screw constituting the Z-axis of the machine. The ball screws are mounted on precision angular contact ball bearings, which are lubricated for life and are coupled to the servomotor using flexible coupling. The ball nut is oil lubricated. The position sensing is done through the incremental encoder with battery backup module built in to the servomotor and the travel limits are constrained in three stages using limit switches, software limits and mechanical stoppers. Axis drive L M Guide ways which are hardened and ground are used for all axis movements ensuring high accuracy and high rapid traverses. Ball screws with preloaded nuts are used for all axes and are coupled to the servomotor through flexible coupling for X and Z axes and through a timer belt for the Y axis. Angular contact ball screw support bearings are used for ball screw support at the driving end and sealed deep groove ball bearings are used at the support end. Index Table This forms the 4th axis (B axis) of the machine and the housing is made of high-grade cast iron and is designed for high rigidity during the machining. This can index the job by 1° with a positioning accuracy of + 3 arc secs. A servomotor with built-in encoder drives this unit through a reduction unit. The index table carries a Table/pallet of 320 x 500 size and can handle a job weight of 150 kgs. The pallet clamping / de-clamping is done hydraulically. The indexing accuracy is obtained by a high precision Hirth coupling. A low-pressure air curtain protects the coupling area and the cone seating area. The cone seating area will have a high-pressure air blast at the time of pallet lifting. Vertical Column This is a rigid, double wall type construction and duly stress relieved cast structure and is fixed on the bed. This structure supports the counter balance arrangement for vertical slide/Y-axis on left hand side and servomotor to drive the Y-axis on right hand side. The automatic high-speed tool changer is mounted on the top of the column. Vertical Slide The vertical slide is made of cast iron, appropriately ribbed and stress relieved and moves on LM guide ways mounted on vertical column, through high accuracy ball screws constituting the Y-axis of the machine. The ball screws are mounted on precision angular contact ball bearings, which are lubricated for life and are coupled to the servomotor through timer pulley and belt. Vertical slide houses a spindle cartridge and drive motor. Hydraulic counter balancing for vertical slide is provided to minimize the spindle drop in the event of power failure. Spindle Cartridge This houses a spindle with ISO40 taper, rotating on three high precision angular contact ball bearings. The tool is clamped by disc springs through a collet arrangement. The de-clamp of the tool is effected through a high-pressure built in hydraulic cylinder. The spindle bearings are protected from dirt and coolant by non-contact labyrinth sealing and air chamber. Spindle housing has six coolant nozzles, which can be adjusted and locked manually to direct the coolant on required points. The spindle orientation for tool change is achieved through a built-in encoder with a spindle motor. The spindle orientation can also be programmed to the desired angle for boring bar retraction. An AC spindle motor drives the spindle through direct coupling, for smooth running of the spindle at high speed. Whenever the tool is taken out or inserted in the spindle, the tool shank is cleaned by air blow. On the bottom side of front flange of the spindle cartridge, a hole is provided for coolant drain. Automatic Tool Changer The automatic tool changer is mounted on top of the column due to which the tool change arm length is reduced to a minimum thereby achieving fast tool change time. The automatic tool changer mainly consists of an arm movement mechanism and a tool magazine. The tool changer arm is a twin arm gripper whose movements are obtained by a combination of two movements i.e. axial and angular. These movements are generated with the help of a roller gear cam and a flat cam. Cams are driven by an electric motor through a reduction gear train. One revolution of camshaft completes the tool change cycle. The tool magazine consists of twenty tool pockets, which are rotated and positioned by an electrical motor. Once the magazine is positioned in the tool change position, it is locked pneumatically to ensure proper alignment with respect to tool change mechanism. Automatic Pallet Changer A rotary type pallet changer, which is mounted on the front of the machine, is indexed by 180 deg (CW or CCW) with the help of a rack and a hydraulic cylinder operates pinion mechanism. A sturdy lifting fork will lift both the pallet by engaging inside the hook blocks. Lift of the fork is by a built in Hydraulic cylinder. During pallet change, air blow provided on the lifting fork avoids the chances of dirt/metal chips entry. CNC Systems & Electrical Cabinet The CNC system is mounted on the right side of the machine. Drives and electrical switchgear are mounted on the panel in Electrical cabinet 22, which is mounted on rear side of the machine. Coolant system and chip conveyor A chip conveyor integrated with coolant tank is provided at the rear side of the machine. The coolant tank is provided with a drum filtration system. The bed wash pump, flood coolant pump and transfer pump for the filtration system is mounted on this coolant tank. A float switch is provided to sense high level and low level of coolant in the tank. A duplex bag type coolant filtration system is used to filter the coolant, which ensures trouble free running of High-pressure coolant pump and coolant rotary union. WE CLAIM: 1. A compact, horizontal, high-speed production center with a width of 1600mm comprising a machine bed, vertical slide, spindle cartridge, table with or without automatic pallet changer system, tool magazine, coolant system, operator panel and electrical cabinets, characterized in that an automatic tool changer mainly comprising of an arm movement mechanism and tool magazine, is mounted on top of the vertical column fixed to the machine bed, the tool axis is being parallel to spindle at tool change position so as to avoid pot tilting arrangement required for tool exchange, the coolant system being placed at the rear side of the machine with chip conveyor running along the depth of the machine, and the electrical cabinet being mounted on the rear of the machine. 2. The compact, horizontal, high-speed production center as claimed in claim 1, wherein the tool changer arm is a twin arm gripper having means to provide axial and angular movement. 3. The compact, horizontal, high-speed production center as claimed in claim 2, wherein the means to provide axial and angular movement is a roller gear cam and a flat cam driven by an electric motor through a reduction gear train. 4. The compact, horizontal, high-speed production center as claimed in claim 3, wherein the tool magazine consists of 20 tool pockets which are rotated and positioned by an electric motor, a pneumatic locking means to ensure alignment with respect to tool change mechanism. 5. The compact, horizontal, high-speed production center as claimed in claim 1, wherein the coolant tank is provided with drum filtration system. Dated this 28th day of November 2005.

Documents:

1290-che-2004 claims granted.pdf

1290-che-2004 correspondence others.pdf

1290-che-2004 correspondence po.pdf

1290-che-2004 description (complete) granted.pdf

1290-che-2004 form-3.pdf

1290-che-2004 abstract original.pdf

1290-che-2004-abstract.pdf

1290-che-2004-claims.pdf

1290-che-2004-correspondnece-others.pdf

1290-che-2004-correspondnece-po.pdf

1290-che-2004-description(complete).pdf

1290-che-2004-description(provisional).pdf

1290-che-2004-drawings.pdf

1290-che-2004-form 1.pdf

1290-che-2004-form 18.pdf

1290-che-2004-form 26.pdf

1290-che-2004-form 5.pdf