LTTS Designs Special Purpose Machine for Grooving Consistency and Safety

About the Client:  The client, one of the world’s largest piping and casting solution providers, uses several Special Purpose Machines (SPM) for specific tasks during the manufacturing process.  One such task is to create grooves for fitting pipes.  The existing process relied on creating grooves manually.  This resulted in inconsistent grooves, required a lot of time, and was risky as the work involved a rotating spindle.  The client was on the lookout for a partner who could help them automate the process to improve grooving consistency and safety.  LTTS’ (L&T Technology Services Limited) expertise in cross-pollinovation and engineering special purpose machines, such as the World’s 1st Gyro Screwdriver, made it the perfect partner of choice for this project.

Challenges:  The client’s main challenges:

• Groove inconsistency: With more than 230 product variations, the client found it difficult to maintain a steady groove consistency.
• Ergonomics and safety: With the existing setup of manual loading and unloading, the groove operators had to stand for hours together at one place.  This was not an ergonomically ideal condition of working.  Also, the process created a lot of flashes (waste products) that were thrown around the machine.  All these factors, along with a spindle that rotates at 24,000 RPM, raised concerns around worker safety.

Solution:  LTTS’ engineers did a thorough analysis of the current working setup and proposed a semi-automatic SPM to conduct the desired grooving.

Design:  The new design consisted of a spindle that moves at half the RPM of the original machine and a cutter that moves in a linear axis to groove the product’s circumference.  The entire machine is modular and can be easily configured to groove different product lines with minimal changes.

Machine vision: A laser-based machine vision system controlled by PLC ensures that the product is positioned correctly before moving the cutter.

Proofing:  The Poka-Yoke based position detection sensor ensures the right part is loaded with right orientation. If there is any discrepancy, it will raise an alarm and the spindle will not rotate.

Quality:  A separate machine vision system checks for the groove depth and width with a master image that ensures consistency of each groove.

Safety:  The complete setup is placed inside a glass enclosure and the machine operates only when the light sensors are active.  In this semi-automatic setup, the worker positions the product for grooving and moves out to a safe distance.  The machine starts the operation only after this process is completed, thus protecting the worker from flying debris.

Quantifiable Benefits:  The client benefited in multiple ways:

• Zero Defects:  This semi-automatic setup involves very limited manual intervention and brought the rate of product rejection to zero.
• Less overhead: One such semi-automatic SPM was able to handle the load of 5 manual machines.  The entire year’s workload could be handled by one machine, thereby reducing the capital overhead.
• Time:  The completion time for each process was brought down by more than 50 percent.
• Safety:  The machine incorporates multiple safety systems and being in a glass enclosure, the noise is significantly reduced.  This enhances the working condition and safety of the operators.
• Maintenance: The new machine consists of several gears ensuring optimum rotation, thus cutting down the service interval by 75 percent.