The present invention relates to a device for enhancing capability of a manufacturing machine capable of performing, on metals or other hard surfaces, vital machining operations such as facing, milling etc. by distribution of machining loads of static and dynamic nature through an alternate arrangement of tool clamping. More particularly the arrangement and working of the developed device has been demonstrated in this patent application through establishing a process for intricate and precise machining performed on joint plane of a turbine casing on a horizontal boring machine.
Machine hereafter in this application means ‘Horizontal Boring Machine’ unless stated otherwise.
BACKGROUND OF THE INVENTION
The progress and the prosperity of human civilization are governed and judged mainly by improvement and maintenance of standard of living through availability or production of ample and quality goods and services in areas viz. transport, power, medicine, communication etc. Such prosperity to human standards chiefly depends on availability of natural resources, exertion of human efforts; both physical and mental and development and use of power tools and machines (Tools).

Machine tools and production or manufacturing capability thereof can be simply defined as value addition processes by which raw materials of low utility and value due to its inadequate material properties and poor or irregular size, shape and finish are converted into high utility and valued products with definite dimensions, forms and finish imparting some functional ability.
Most of the engineering components such as gears bearings, clutches, tools, screws and nuts etc. need dimensional and form accuracy and good surface finish for serving their purposes. Performing like casting, forging etc. generally cannot provide the desired accuracy and finish. For that such preformed parts, called blanks, need semi-finishing and finishing and it is done by machining and grinding. Machining to high accuracy and finish essentially enables a product to fulfill its functional requirements, improve its performance, and prolong its service.
Production Management is also equally important and essential which mainly refers to planning, coordination and control of the entire manufacturing in most profitable way with providing maximum satisfaction to the customers through best utilization of the available resources like man, machine, materials and money.
It is largely possible to manufacture a product of given material and desired configuration by several basic manufacturing processes such as facing, boring, drilling, turning etc. as well as advance manufacturing processes.

With the increase of versatility and precision (e.g.) CNC machines) and the advent of dedicated high productive special purpose machines, the need of using attachments is gradually decreasing rapidly. However, some special and customized-for-specific-use attachments, i.e., copying templates, taper turning attachment etc., are still being used purposefully on different machines for increasing the capability of a machine in terms of ergonomics for better user experience, lower power consumption, better quality output and above all, efficiency to constantly provide fit-for-use products.
Various attachments exist for the spindles of vertical milling machines which are designed to hold cutting tools such as milling cutters, drills, and other tools intended to cut the material in one way or another. The material to be machined is clamped either directly to the milling table or held in some type of holding mechanism attached to the table.
For example, a facing operation (an operation of machining work to produce a flat surface) performed on the joint plane of each half of a steam turbine outer casing used in coal based thermal power plants. The precise flatness of the joint plane is responsible in enforcing the operating steam to remain in the turbine’s main body and therefore helping the power plant to work effectively and therefore save a lot financially. However, it is difficult to keep the joint sufficiently tight across the entire joint plane to prevent leakage primarily due to unevenness present in the surfaces forming the joints.
On investigation it was found that after completing one machining run on the entire length of the facing operation, the tool advance the next time to cover the entire width of the job. This allows the cutting edges to overlap.

Such situation often arises with production engineers where it is required to use bigger tools but the capability of machine does not suffice. In the case of facing, the width of the joint plane is say 400 mm whereas the facing tool diameter is 150 mm which means it has to pass three times over the width of the joint plane thereby proving unavoidable cutting edge overlap.
One obvious solution to avoid such situation is to use a bigger facing tool. However, using a bigger tool comes with a bigger problem of machine’s capability limitation. Since most machines are designed for a particular power rating and the operational loads that mechanical components such as bearings, shafts, etc. can sustain, imposing a limitation on the machine’s performance and productivity thereof.
The bigger facing tool shall cut more surface area (entire width in this case) in one rotation and thereby shall put larger cutting forces on its hydraulic clamping that supports the mandrel and the cutting tool thereby.
Also, after the machining of the joint plane, flatness of the joint plane of both halves of the turbine outer casings is checked using color in which the colored oil is rubbed onto joint plane of one casing as reference surface, and the half casing is then placed against other casing half. The transfer (by contact) of the color indicates the position of surface irregularity on the casing flatness. This method has been used to test the flatness of surfaces.

This cutting forces are generated by the hydraulic ram of the horizontal boring machine which result in heavy cutting pressure over the hydraulic clamping arrangement resulting in machine breakdown and hence, lower productivity.
Also whenever a surface irregularity is found in the color matching test of the joint planes of the casing halves, finishing operations such as grinding, filing are performed manually. For casings halves corresponding to large rating steam turbines, weighing over 15 tonnes or so, the repeated color matching tests and reworking can consume a large time and increase substantial operational cost. Thus following issues are frequently encountered:
1) High Cycle time: As described, since large axial force was experienced by the machine hydraulic clamping mechanism and this can results in possible damage of hydraulic pipes, we had to restrict the cutting speed and feed to very low value. Additionally, color matching of such huge turbine casing was done to find out the irregularities and then these irregularities were to be taken care through finishing operation at joint surface. These resulted in large cycle time and further in decrease in productivity.
2) Poor Quality: Since facing operation done in multiple feed over the joint plane resulted in poor surface finish, surface irregularities and overlapping of machined surface.
3) Frequent Machine Breakdown: As large axial forces were directly going on to the hydraulic mechanism. So, if we run the machine on slightly high rpm, clamping forces shall exceed resulting in stoppage or breakdown in machine.

High Operators fatigue: As cycle time for each rotor was very high and due to machine breakdown, the operator had to offset the machine breakdowns. These and hence these factors results in high operators fatigue.
Delayed delivery to the Customer: Due to high cycle time as discussed above we were not able to meet delivery schedule and delivery to internal customers used to get delayed.
In order to avoid this cutting force to reach the hydraulic clamping by which the mandrel is clamped and provide a sustainable solution to limitations in prior art, a device (refer Fig.5) is proposed that entirely eliminates the use of hydraulic clamping as per prior art and that shall sustain the machining pressure/forces.
OBJECTS OF THE INVENTION
An object of the invention is to develop a device that enhances capability of a manufacturing machine through distribution of machining loads.
Another object of the invention is to develop a device that enhances capability of a manufacturing machine through better distribution of machining loads that allows using bigger tool thereby reducing the machining time per casing by 30 to 35%.

Yet another object of the invention is to develop a device that enhances capability of a manufacturing machine through distribution of machining loads by eliminating the use of existing hydraulic clamping arrangement and thus prevents frequent machine breakdown.
A further object of the invention is to develop a device that enhances capability of a manufacturing machine through distribution of machining loads to be able to produce high quality flatness and reducing rework time in color matching.
BRIEF DESCRIPTION OF ACCOMPANIED DRAWINGS
Figure 1 Represents turning operation on a shaft done for reduction of diameter.
Figure 2 Represents facing operation on a shaft done for decreasing the length.
Figure 3 Represents 3-D view of a steam turbine inner casing.
Figure 4 Represents 2-D sectional view of a steam turbine comprising rotor with moving blades, inner casing with fixed or guide blade and outer casing.
Figure 5 Represents 2-D view of the developed device for enhancing machining capability of a manufacturing machine performing facing operation through distribution of machining loads.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Referring to the figure 5 in detail, it will be seen that the embodiment of the invention
which has been illustrated comprises of:
Item 1. Flange Item 2. Plurality of Counter Bore Holes
Item 3. Plurality of Threaded Hole Item 4. Plurality of Threaded Hole
Item 5. Protrusion Item 6. Stepped Collar
Item 7. Headstock Joint Surface Item 8. Machine’s Headstock
Item 9. Turbine Rotor Item 10. Turbine Outer Casing
Item 11. Turbine Inner Casing Item 12. Moving Blades
Item 13. Guide Blades Item 14. Joint Plane Surface
Item 15. Machine’s Threaded Hole Item 16. Center Hole
Item 17. Plurality of threaded holes in headstock (8)
Item 18. Plurality of threaded holes in headstock (8)
Figure 5 shows 2-D view of the developed device for enhancing machining capability of a manufacturing machine performing facing operation, on the joint plane (14) of turbine casing (10) that embodies in it a turbine rotor (9) and a turbine inner casing (11), through distribution of machining loads and all the major components have been marked in figure 5.
The fixture includes a flange (1) having in it a stepped Collar (6) that would butt with the machine headstock (8) on the headstock joint surface (7) in such a way that the fixture can be mounted on headstock (8) of the machine through plurality of counter bore holes (2) that shall be on the same axis the machine’s threaded hole (15). The stepped collar (6) is designed in such a way that it works as a poka-yoke for error proof in mounting the fixture (F).

The center hole (16) shall be used for picking and lifting up the entire fixture (F) through an overhead crane.
The protrusion (5) would fit in the replica depression in the cutting tool. Plurality of threaded holes (3 and 4) equispaced at different diameters, for pairing up with respective bolts, would help to clamp the multi-point facing tool (circular in shape) with the machine in such a way that the bolts passes through the facing cutter then to the fixture (F) through plurality of threaded hole (3) and plurality of threaded hole (4) and finally resting itself in the plurality of threaded hole (17 and 18) of machine’s headstock (8). These clamping bolts would immensely support static and dynamic forces during the machining operation such as the large cutting forces during the facing operation, centrifugal forces due to high rotation on fixture (F) and cutting tool as well as the gravitational forces due to the weight of the fixture (F) and cutting tool.
The supporting fixture is introduced in the system for supporting the cutting tool as well as transmitting cutting forces towards the foundation of the machine. Also it enables one to use large size cutting by providing alternative clamping arrangements for such large size cutters. This makes hydraulic clamping of machine safe and secure from the multiple forces as all the force are transferred by the invention to the machine foundation. Therefore, the facing operation can be carried out at high R.P.M. and in one go which increases the productivity, save the time and improves the quality.

Since, it might now be apparent that the embodiment of the invention, as described hereinabove, will provide an extremely critical fixture for enhancing machining capability of a manufacturing machine capable of performing facing operation through distribution of machining loads.
The foregoing may be considered as illustrative only of the principles of the invention and it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted too, falling within the scope of the invention as claimed.

WE CLAIM
1. A device for enhancing machining capability of a manufacturing machine capable of
performing facing operation through distribution of machining loads, comprising:-a flange (1) having in it a stepped Collar (6) that would butt with the machine headstock (8) on the headstock joint surface (7) in such a way that the fixture can be mounted on headstock (8) of the machine through plurality of counter bore holes (2) that shall be on the same axis of the machine’s threaded hole (15), the said stepped collar (6) is configured in such a way that it works as a poka-yoke for error proof in mounting the fixture (F), wherein center hole (16) being used for picking and lifting up the entire device (F) through an overhead crane;
the other face of flange (1) is provided with a protrusion (5) that would fit in the replica depression in the cutting tool;
plurality of threaded holes (3 and 4) equispaced at different diameters, for pairing up with respective bolts, helping to clamp the multi-point facing tool (circular in shape) with the machine when the bolts passes first through the facing cutter and then to the fixture (F) through plurality of threaded hole (3) and (4) and finally resting itself in the plurality of threaded hole (17 and 18) of machine’s headstock (8).