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The Mah indra H inoday Industries Case History

automotive electrical components and technology. decade ago, there were just industrial DC motors; and ferrite cores two or three automatic pouring Commissioned in early 2004, the new for electronics, telecommunications systems operating in India. automatic pouring system featured a and special applications.Even five years ago, you could count well-insulated, unheated tundish with

these systems on one hand. But today As early as 2003, Mahindra Hinoday a 2 ton capacity, an accurate stopper-

there are more than a dozen automatic Industries began investigating the rod pouring mechanism and precise,

pouring systems in operation at Indian advantages automatic pouring responsive vision-based controls.

foundries. technology might provide. The company Because it was to be used to pour

was particularly looking for a system to ductile iron, the automatic pouring These automatic pouring systems are pour ductile iron at the company's system also included in-stream found at the most innovative and automotive castings foundry. The inoculation and Inductotherm's quality-oriented foundries in India. system would be used with an existing automatic reaming system to reduce And their success is leading the way +GF+ flask molding line. slag buildup in the pouring nozzle. for a more widespread adoption of this

Installed on the 96 mold per hour modern technology. The search for the best system to +GF+ line, the automatic pouring meet Mahindra Hinoday Industries' Automatic pouring allows foundries to system poured molds as large as 120 requirements included a visit to the eliminate the armies of workers kg for automotive castings including 2003 GIFA foundry show in Germany needed for the dangerous work of turbine housings, engine brackets, and to several automatic pouring manual pouring. While this is a major exhaust manifolds, power and system manufacturers. Ultimately, the economic advantage where labor mechanical steering housings, crank company ordered an Inductotherm costs are high, it is not the most shafts, differential cases, carrier automatic pouring tundish system with significant consideration in India. housings, hubs and knuckles.Visipour® vision-based control Increased casting production, higher

casting quality and enhanced worker

safety made possible by automatic

pouring technology are the most

important advantages.

Mahindra Hinoday Industries is a very

good example of an Indian foundry

benefiting from automatic pouring

technology.

With 40 plus years of manufacturing

experience, Mahindra Hinoday today

is a highly regarded name in ductile

iron castings and ferrites worldwide.

Staffed by more than 800 employees

and with US$55 million US dollars

invested in two manufacturing plants

at Pune, India, the company casts

ductile iron parts for the automotive

industry, ceramic magnets for

June 201024

Technolo

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Automatic Pouring Systems Boosts Output at Mahindra Hinoday Ind

By: Sanjay Paranjape, Vice President - Operations, Mahindra Hinoday Industries Ltd.; and

P .D. Chaubal, Product Manager, Inductotherm India Pvt. Ltd

This highly productive automatic pouring system at Mahindra Hinoday Industries’ automotive castings foundry uses Inductotherm’s highly responsive stopper-rod pouring mechanism and Visipour® vision-based control technology for precise pours, mold-after-mold, without operator intervention.

June 2010

Production Increases Were Immediate

Automatic Pouring Improves Casting Quality

metal temperature drop to between front of the mold. However, fully

2°C and 2.5°C per minute, assuring a computerized, vision-based pouring

proper pouring temperature between controls are able to automatically Prior to installing its automatic refi l ls. At Mahindra Hinoday adapt pouring to a variety of variables.pouring system, Mahindra Hinoday Industries, this also meant that it was These included the size, shape and Industries managed an average daily no longer necessary to superheat position of the sprue cup; the changing production of 100 tons per day, metal in the furnace to offset the viscosity of the metal as the running 24 hours, using manually losses incurred during metal transfer temperature varied; and changes in poured ladles to fill the molds. It also using the manual ladles. the nozzle opening.experienced an average metal loss of Typically with manual pouring, the 3 percent as a result of splashing and This control adaptability allowed each temperature drops about 70°C from over pours during manual pouring. mold's sprue and runner system to be the transfer at the holdingOverall, casting yield was about 61 optimized. A smaller sprue cup and

percent. furnace until the last good casting is more efficient runner system in the

poured. The larger, more thermally mold reduced metal use.A significant limitation that prevented efficient transfer to and through the average daily production from l Limited Fading – When working automatic pouring tundish was surpassing 100 tons was the frequent with molten ductile iron, magnesium calculated to suffer only half that loss, need to stop the line waiting for iron. fade must be controlled in the a drop of just 45°C. This resulted in a Much of this delay occurred because processes used. Automatic pouring savings in furnace power costs.metal in the pouring ladles had makes it simpler to limit magnesium

become too cold. But production time l Reduced metal loss - Metal fade due to the carefully controlled was also lost in exchanging or refilling splashing and over pours while filling timing of metal replenishment in the pouring ladles, changing operators, the mold were greatly reduced tundish.rest breaks for metal pourers, etc. due to the precision of the pouring However, within just six months of mechanism and vis ion-based switching to automatic pouring, controls. This cut the metal loss from

The way a mold is poured has a Mahindra Hinoday Industries started upwards of 3 percent to less than 1

significant impact on casting quality.routinely achieving production levels percent

With hand pouring, even the most of 120 tons per day with an overall l Smaller sprue cup and optimized skilled workers cannot fill every mold increase in casting yield to 67 percent. runner system - Manual pouring with an ideal pour. And anything less

Mahindra Hinoday Industr ies necessitated a large, oblong sprue cup than the ideal pour could produce a

attributed this one-third increase in and it had to be brought all the way to casting that does not meet the quality

production to a number of factors

directly related to its Inductotherm

automatic pouring system:

l More efficient management of the

transfer of molten metal for pouring -

As noted earlier, with manual pouring

it was difficult to keep the molten

metal in the many pouring ladles

within the proper pouring temperature

range. Often, the mold line would be

stopped to allow the cold metal in the

pouring ladles to be replenished with

metal at the proper temperature. This

does not happen with the automatic

pouring system.

Every 10 minutes the 1100 kg transfer

ladle brings hot liquid metal from the

foundry's two 6000 kg Inductotherm

induction furnaces to the tundish.

Furthermore, the well-insulated,

thermally efficient tundish limits the

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Perfectly filled molds move from the automatic pouring system along the now empty manual pouring line. Overall production jumped from 100 tons per day to 120 tons per day shortly after the automatic pouring system was commissioned. When more melting/holding capacity was added to the melt shop, the automatic pouring system was able to process 160 tons of production per day.

June 2010

standards for that product. pouring at the Mahindra Hinoday required by the furnace operator and

Industries' automotive castings the bottom pour tundish is relined Casting defects can be caused by all of foundry from 0.75 percent to 0.15 periodically, this represents minimal the following problems directly percent, a significant reduction and work when compared to the job of attributable to manual pouring:important cost savings. maintaining the large number of l The pourer did not fill the mold with

manual-pouring ladles that were used enough molten metal, producing an with manual pouring.incomplete casting. The automatic pouring system at l Improved working environment - l The pourer interrupted the pouring Mahindra Hinoday Industries' With automatic pouring there are stream and allowed the sprue to empty automotive foundry completely fewer workers in close proximity to before continuing. This would cause eliminated the need to expose large the heat of molten metal and less voids in the casting. numbers of workers to the many exposure to smoke and fumes.

dangers associated with manual l The mold was poured too fast, l Commitment to quality and pouring molds. These common producing excessive turbulence in the productivity – The use of automatic hazards included metal splash, mold and interfering with metal flow. pouring technology demonstrates to exposure to radiant heat, inhalation of This could cause inclusions in the customers that Mahindra Hinoday smoke and fumes, burns from contact casting or misruns.Industries is a modern, quality with hot surfaces, back injury, etc.l The metal was allowed to become conscious, production oriented

The reduction in tapping temperature too cold and did not flow properly in casting facility.

made possible by automatic pouring the mold causing misruns, cold shunts Increased Melting Capacity Increases also significantly increased the and round corners.Automatic Pouring Productionoperating safety margin for furnace A high casting rejection rate caused When production at the Mahindra overheating errors. This, in turn, by any or all of the above manual Hinoday Industries' automotive resulted in longer refractory life and a pouring difficulties is very costly for castings foundry grew from 100 tons commensurate reduction in refractory foundries.per day to 135 tons per day after costs.

At Mahindra Hinoday Industries the operation of the automatic system

rejection rate due to pouring averaged began, the decision was made to add

0.75 percent before automatic pouring While reducing labour costs is not the more metal production capacity to the was installed. most important reason for a foundry in foundry's melt shop.However , Mah indra H inoday India to install automatic pouring, it is, It was clear that the automatic pouring Industries' automatic pouring system nevertheless, an important advantage. system could pour additional molds if eliminated most of the casting defects While operating with manual pouring, more liquid metal were available. caused by problems inherent in Mahindra Hinoday Industries' Therefore, a 2000 kg, 1000 kW induction manual pouring. The system's vision- automotive foundry required four melting furnace was added to the two based control technology prevented pourers on each shift. 6000 kg induction melting furnaces both metal wasting over pours and Today, however, only a single sharing a 3500 kW power supply.quality robbing under pours. operator on each shift is responsible The operational efficiencies provided Moreover, it precisely maintained the for setting up and monitoring the by the additional holding furnace optimal pouring profile needed to automatic pouring system. And since enabled the number of 1100 kg ladles maintain the desired metal level in the the system, under computer control, supplied to the pouring tundish to be sprue cup throughout every pour. functions largely without operator increased from 5 per hour to 6 per Finally, simplified management of intervention, that single operator is hour. This resulted in production pouring temperature eliminated a able to perform multiple other tasks. being increased from 120 tons per day common source of misruns, cold

to 140 tons per day using the same shunts and rounded corners.

automatic pouring setup.It is key to note that with automatic

And when the 2000 kg, 1000 kW The fundamental operational changes pouring, all the molds in a particular melting furnace was later replaced with brought about by automatic pouring pattern are poured exactly alike, a 3000 kg, 1500 kW melter, 7 ladles produce savings and efficiencies in a providing a high level of consistent were supplied to the tundish each hour number of areas in the foundry. These quality in the foundry's casting output.and overall production increased to 160 include:

As a result, automatic pouring reduced tons per day, again using the same l Reduced maintenance - While the the casting rejection rate due to automatic pouring system. This high stopper rod and nozzle are changed as

Enhanced Safety

Reduced Labour Costs

Other Savings Generated By Automatic Pouring

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Technolo

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June 2010

level of production, coupled with a

casting yield that had grown to 69

percent, has allowed Mahindra Hinoday

Industries' automotive castings foundry

to produce 2750 tons of casting each

month.

Rapid Payback of Capital Expense

As a direct result of the financial

benefits accruing to Mahindra

Hinoday Industries from the increased

production, higher casting quality (and

reduced rejection rate), enhanced

safety and lower labour costs

resulting directly from the installation

and operation of its new automatic

pouring system, the payback period

for the system proved to be just over

six months. Few capital investments in

the foundry industry would be able to

match this payback record.

While automatic pouring seemed to

get a slow start in the Indian foundry

industry, wider recognition of the

principal benefits of this technology,

including increased production, higher

casting quality, enhanced safety,

reduced labour costs and a quick

investment payback are now speeding

the adoption of these important

foundry production systems.

Conclusion

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Technolo

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The Visipour® console in the control room (center) is linked to a video camera to monitor each pour. The computer then adjusts the pour to adapt to current conditions, producing the desired pouring profile even if there are changes in variables, such as the nozzle opening or metal temperature. With Visipour®, little or no operator intervention is required and the operator can attend to other duties during much of his shift.