Title of Invention

TWO- WAY CNC HORIZONTAL MACHINING CENTER

Abstract

This invention relates to a two way CNC Horizontal Machining center used for machining the component in different setups. The two way CNC Horizontal Machining Center with trunnion mounted hydraulic fixture is the unique solution for engine blocks machining in a single set up. This fixture mounted on the central table allows accommodation of different models of engine blocks with their variants. It also facilitates machining on inclined faces of the engine block, in addition to machining four faces of the engine block in a single set up.

Full Text

FIELD OF THE INVENTION This invention relates to a two way CNC Horizontal Machining center used for machining the component in different setups. BACKGROUND Demand for higher flexibility, reduced cycle time and increased precision, together with low cost per piece ratio are often the challenges posed in providing machining solutions, especially in sectors like engine manufacturing, auto component machining etc. It becomes all the more critical when it comes to machining of heavier engine blocks in different models, with its variants in a single machine for multiple operations on different faces of the block. DISCUSSION OF PRIOR ART Existing Method: At present, these components, like cylinder blocks are machined in different machines for different faces and operations, like radial drilling, multiple spindle Special Purpose Machines (SPM) etc), in different set ups. Achieving accuracies with several set up changes in a sustained manner on a production basis is a challenge for the manufacturers. The cost per piece is also substantially very high. To achieve higher accuracy levels in machining and also to reduce the costs in production, the present invention proposes a novel two way CNC special purpose horizontal machining center. Advantages of the Present Invention: With this two-way machining concept, the challenges of providing machining solutions at a reduced cycle time, increased precision, low cost per piece with higher flexibility can be easily achieved, in a single set up. SUMMARY OF THE INVENTION Machine construction: The machine consists of the following modules: ? Main machine (RH & LH side) ? Central Machine ? Automatic tool changer and Tool magazine ? CNC system & Electrical cabinet ? Coolant system with chip conveyor ? Pneumatic system & Hydraulic system ? Guards MAIN MACHINE (RH & LH side): This module consists of the following parts: Machine Bed: This is a sturdy steel fabricated structure, which is stress relieved to maintain the machine accuracy for years. This supports all the three axes drives and the spindle, and has been designed keeping in mind the efficient disposal of the chips and collection of lubrication oil from various machine elements like axes drives, LM guides etc. Cross slide: This structure is made of spheroidal graphite (SG) iron box type casting for high rigidity and is stress relieved. This unit moves on the LM guides mounted on the main bed and is driven by a servomotor through a high accxiracy ball screw (045) constituting the X-axis of the machine. The ball screws are mounted on precision angular contact 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 absolute encoder built into the servomotor and the travel limits are constrained in three stages using limit switches, software limits and mechanical stoppers. Vertical column; This is a sturdy steel fabricated structure and is stress relieved to maintain the machine accuracy for years. This moves on the LM guides mounted on the cross slide and is driven by a servomotor through a high accuracy ball screw (dia45) constituting the Z-axis of the machine. The ball screws are mounted on precision angular contact 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 absolute encoder built into the servomotor and the travel limits are constrained in three stages using limit switches, software limits and mechanical stoppers. This structure carries the hydraulic counter balancing arrangement for the vertical slide Vertical slide; This is a rigid box type stress relieved high-grade cast iron structure. This moves on the LM guides mounted on the vertical column and is driven by a servomotor through a high accuracy ball screw (dia45) constituting the Y-axis of the machine. The ball screws are mounted on precision angular contact bearings, which are lubricated for life and are coupled to the servomotor using flexible coupling. The ball nut is oil lubricated. This carries the spindle cartridge and the spindle drive arrangement. The position sensing is done through the absolute encoder built in to the servomotor and the travel limits are constrained in three stages using limit switches, software limits and mechanical stoppers. The hydraulic counter balancing arrangement ensures that in case of a sudden power failure during the machining operation the spindle will not drop, hence avoiding damage to the tools and the machine. Spindle; This houses a spindle with BT 50 taper rotating on 3 numbers of dialOO high precision angular contact ball bearings, lubricated for life. The bearings are protected from dirt and coolant by labyrinth seals and an air curtain. The tool clamping is done using disc springs and collet arrangement and the de-clamping is done by means of a hydraulic cylinder. The de-clamping arrangement has been designed to protect the bearings from the declamp force. The spindle cartridge also houses the coolant nozzles, which can be manually set to direct the coolant to any desired location. The spindle feedback is through an encoder driven through a flexible coupling. The spindle drive is powered by a servomotor, through a two-speed ZF (1:1 & 1:4) gearbox. This reduction is achieved by helical planetary gear arrangement for compactness and low noise and the gearbox is capable of changing the gears in less than two seconds. On the bottom side of the front flange of the spindle cartridge, a hole is provided for the coolant to drain. If this drain hole is blocked by any dirt or chip particles, the coolant may enter inside and damage the spindle bearings. Automatic tool changer and Tool magazine : The tool magazine is of chain type with 40 swiveling tool pockets mounted on the chain. The magazine is indexed by an electric motor through a drum cam. A pneumatic cylinder mounted on a stationary plate in the center of the magazine is used to swivel the pocket into the tool change position. Tool changer arm is twin gripper type whose movements are obtained by a combination of two movements i.e. axial and angular. These movements are generated with the help of a globoidal cam and a flat cam. Cams are driven by electric motor through a reduction gear train. One revolution of camshaft completes the tool change cycle. CENTRAL MACHINE: Central Machine bed: This is a sturdy steel fabricated structure, which is stress relieved to maintain the machine accuracy for years. This supports a central table slide with hydromotor and ball screw drive for slide. This base has slopes, which diverts the flow of coolant and chips to chip conveyor. Table slide is a rigid stress relieved high-grade cast iron structure, which moves on hardened and ground steel guide ways. The drive for the central table slide, is through a rolled ball screw and hydromotor. The slide is with button clamps and is actuated at the machining position so that the slide does not get disturbed during the machining of the component. Above the central slide, the hydraulic fixture is mounted, which can accommodate four and six cylinder blocks for machining of the head face, bottom face and bearing cap seat face. CNC System & Electrical Cabinet; A 'FANUC OiMA controller controls the machine. The controller and electrical cabinet are placed on the rear side of the machine. An operator panel consisting of display panel and controls is provided on LH and RH side of the machine. Emergency buttons are provided at various places to stop the machine during emergency. Coolant system with chip conveyor; The machine is provided with a scraper type chip conveyor with a coolant tank with sufficient coolant capacity. The coolant system has a magnetic separator with paper band filtration system with the filtration level being upto 20 microns. Pneumatic, Hydraulic system; The pneumatic system requires air compressed to 6 bar as input and is used for spindle taper cleaning, air curtain for spindle, etc. The hydraulic system is powered by a 301pm, 63 bar power pack and is used for spindle tool declamping, fixture, central axis slide movement etc. Lubrication System; This unit provides metered lubrication for slides, lead screw, fixture elements etc., at preset time intervals. An oil level indicator is provided to monitor the oil level in the unit. A float switch in this unit actuates the 'OIL LEVEL LOW indicator on the control panel. Machine Guards: The machine is provided with a safety guard, which has been designed keeping in view the maintenance - with easily removable panels for easy approach to maintenance areas and leak proofing of the machine BRIEF DESCRIPTION OF DRAWINGS Fig 1. illustrates the Two way CNC special purpose Horizontal Machining Center of the present invention; Fig 2. illustrates the top view of the Horizontal Machining Center; Fig 3. illustrates the view from Right Hand side of the Machine; Fig 4. illustrates the view of the central base along with the fixture; and Fig 5. illustrates the rear side view of the Horizontal Machining Center DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS New Innovative Method: The Two way Horizontal Machining Center is built with two Modules - LH side module, shown in Fig. 1, part 5, and RH side Module, shown in Fig. 1, part 6, one on each side of a central table, shown in Fig. 1, part 12. Each module consists of a modular base, saddle and a column, shown in Fig. 1, part 7, part 8 and part 9, respectively. The spindle cartridge, shown in Fig. 1, part 10, is mounted on a vertical slide, shown in Fig. 1, part 11, that moves on the column. The column is mounted on the saddle, which in turn is mounted on the modular base. The individual units move on LM guides (12) and are driven by a servomotor, shown in Fig. 2, part 13, through a high accuracy ball screw. The ball screws are mounted on precision angxilar contact bearings, which are lubricated for life and are coupled to the motor using flexible coupling. Each module is provided with 3 CNC axes for simultaneous machining operations on two opposite faces of a cylinder block in a single set up. The CNC in RH & LH has basic 3 axes and spindle. The common functions, like those of the hydraulic power pack, coolant system, central table and fixture are all controlled by RH side CNC and is called as MASTER. The LH CNC is called SLAVE receives the signals from RH for the above common functions. The trunnion fixture, shown in Fig. 1, part 2, is mounted on the central table. This fixture accommodates different models of engine blocks along with their variants. It also facilitates machining on inclined faces of the block, in addition to machining four faces of the engine block in a single set up. The fixture has a drive end and a tall end, depicted in Fig. 4, part 14 and part 15, interconnected through a central bracket, shown in Fig. 4, part 16. The central bracket along with the component can be rotated and clamped at a pre-determined position by a hydraulic operated indexing pin, shown in Fig. 4, part 17. Disc/face clamps are incorporated to clamp both sides of the central bracket for rigid holding during machining. Independent Tool magazines, shown in Fig. 5, part 3 and part 4, are provided for both the modules. The capacity of these magazines is 40 tools each. The two way CNC Horizontal Machining Center with trunnion mounted hydraulic fixture is the unique solution for machining engine blocks in a single set up. This fixture mounted on the central table allows accommodation of different models of engine blocks with their variants. It also facilitates machining on inclined faces of the engine block, in addition to machining four faces of the engine block in a single set up. The operations carried out are drilling, boring, tapping, counter-boring, reaming and milling. The operations are performed simultaneously on two faces. The machine has a work envelope of 1200 mm x 630 mm and allows a table load of 2500 kg. WE CLAIM: 1. A two-way CNC Horizontal Machining Center with two Modules - LH side module and RH side Module, one on each side of a central table wherein: a. each module consists of a modular base, saddle and a column with the spindle cartridge mounted on a vertical slide that moves on the column; b. the column is mounted on the saddle, which in turn is mounted on the modular base with the individual units moving on LM guides and is driven by a servomotor through a high accuracy ball screw; c. the ball screws are mounted on precision angular contact bearings, which are lubricated for life and are coupled to the motor using flexible coupling. 2. A two-way CNC Horizontal Machining Center as claimed in claim 1(a), (b), (c) with each module being provided with 3 CNC axes for simultaneous machining operations on two opposite faces of a cylinder block in a single set up. The CNC in RH & LH has the basic three axes and spindle; 3. A two-way CNC Horizontal Machining Center as claimed in claim 2, where the common functions like those of the hydraulic power pack, coolant system, central table and fixtures are all controlled by RH side CNC, which is called as MASTER, the LH CNC being called as SLAVE as it receives signals from RH for the above common functions. 4. A two-way CNC Horizontal Machining Center as claimed in claim 3, with independent tool magazines provided for the modules, the capacity of said magazines being 40 tools each. 5. A two-way CNC Horizontal Machining Center as claimed in claim 4, comprising a work envelope of 1200 mm x 630 mm which allows a table load of 2500 kg. 6. A two-way CNC Horizontal Machining Center as claimed in claim 5, including a trunnion mounted hydraulic fixture for machining engine blocks. 7. A trunnion fixture mounted on the central table of a horizontal machining center to accommodate different models of engine blocks with their variants facilitating machining on inclined faces of the block, in addition to machining four faces of the engine block in a single set up with the operations carried out including, but not limited to, drilling, boring, tapping, counter-boring, reaming and milling, with the operations being performed simultaneously on two faces, comprising of a drive end and a tall end, interconnected through a central bracket where the central bracket along with the component can be rotated and clamped at a predetermined position by a hydraulic operated indexing pin, with disc/face clamps being incorporated to clamp both sides of the central bracket for rigid holding during machining. DATED THIS 28th DAY OF NOVEMBER 2005.

Documents:

1292-che-2004 abstract-duplicate.pdf

1292-che-2004 abstract.pdf

1292-che-2004 claims granted.pdf

1292-che-2004 claims-duplicate.pdf

1292-che-2004 description (complete)-duplicate.pdf

1292-che-2004 drawings-duplicate.pdf

1292-che-2004 form 2.pdf

1292-che-2004 form 3.pdf

1292-che-2004-abstract.pdf

1292-che-2004-claims.pdf

1292-che-2004-correspondnece-others.pdf

1292-che-2004-correspondnece-po.pdf

1292-che-2004-description(complete).pdf

1292-che-2004-drawings.pdf

1292-che-2004-form 1.pdf

1292-che-2004-form 18.pdf

1292-che-2004-form 26.pdf

1292-che-2004-form 5.pdf