Forging Shop
Forging
Connecting rods for automotive applications are typically manufactured by forging from either wrought steel or powdered metal. The raw materials are cut a little more than the required size for further processing. The billets are heated in the furnace at 500-600 degree Centigrade. These billets are sent to the hot forging units where the metal is made to work above its recrystalization temperature. During this process the metal is deformed and the strain-hardening effects are negated by the recrystalization process. After forming the basic profile, the connecting rods are forged to their actual size and go out of the forging unit.
Machining
The forged connecting rods are brought to the machine shop and pass through a series of operations to make them ready to fit. The first process is rough machining, where the forged conrod is shaped according to size. Then, these connecting rods enter into a gantry machine; here about 4 to 5 operations are done like piercing, trimming and drilling. The single part conrod finally has to be made into 2 parts, to separate the cap from the body. Fracture splitting process is carried out after the machining process.
Assembly
The fracture splitting process is followed by the assembly operation where a plain bearing shell is fitted in between the 2 ends and is connected with a pair of bolts and nuts. The rod and cap are finish machined using several operations including broaching, milling, boring, honing, fringing and other finishing steps. A substantial quantity of metal is removed to get the final dimensions and finish. The quantity of metal removed during the machining process is typically around 25-30%.
Engineering Centre
Inspection and Dispatch
Sansera has also deployed ‘vision system’ for inspection by which products assembled will be imaged by a digital camera, and the image will be analysed for critical parameters. During final inspection a robot inspects the components and segregates them according to the bore and weight of each connecting rod. This helps in curtailing rejections going to the customer. The connecting rods are finally washed in oil to clean it, packed in separate covers and dispatched to customers.
Machining Line
Manufacturing Excellence
The company has contained the cost of components by an alternative manufacturing process meeting their functional requirement, where some customers have benefited to the extent of about 30% cost reduction. Normally, Sansera manufactures the components according to the drawing; now, after garnering expertise for more than 25 years, it has started codeveloping the products along with the OEMs. By doing so, the company has eliminated the practical issues caused during manufacture, thereby reducing the overall cost of components.
Interview
F R Singhvi, Joint Managing Director, Sansera Engineering
Q: What is the capacity utilisation of the Bommasandra plant?
Singhvi: Currently we are utilising 80% of our capacity. We forecast the orders and plan to have additional capacity always.
Q: How do you plan to enhance productivity?
Singhvi: We are seriously looking into low cost automation, where we wanted to increase the productivity. A number of processes in the machining and forging of connecting rods have already been automated. Currently our plant is semi-automated and still we feel that there are some more critical operations where we see further scope of automation.
Q: Can you tell us about your expansion plans?
Singhvi: The existing capacity and the orders we have force us to expand our capacity at the Bommasandra facility. We are adding a forging press to increase our capacity from the current 4 million connecting rods to 10 million. During the expansion phase we will be setting up a new line for machining and forging.
Q: How much will you be investing for the expansion programme?
Singhvi: To set up a forging line, we will be investing Rs 10 crore. We are continuously expanding all our plants, where we have invested Rs 80 crore last year and this year we propose to invest about Rs 120 crore, which includes land, building and machinery.
ACI
