An IC engine's piston is attached to an open-ended piston ring that slides into a groove on the piston's outer diameter. When it comes to automobile pistons, there are often three rings. The lowest ring is used to control the flow of lubricating oil, while the first two rings are compression rings for compressing seals (oil control ring). The manufacturing problems with the contacts created by the piston rings have received a great deal of attention over the years, as seen by the enormous number of articles that have been written about them recently. The purpose of this case study is to explore the issue of piston ring manufacturing quality.
A Perfect Circle, which was founded in 1976 and has since gained recognition in the Indian automotive sector, is a significant supplier of piston rings to both Indian and international original equipment manufacturers and replacement markets. With Mahale, engine components, USA, a global leader in the automotive sector, the business has a technical license. The firm makes production plates, a specific part for fuel pumps and transmissions, as well as piston rings, a vital automotive component that is sold under the global brand Label by Perfect Circle. The perfect circle (Anand Group) in India has received certification from Bureau Veritas Quality International, UK, for TS 16949, ISO 14001, and OHSAS 18001 standards. The largest maker of piston rings, plates, and piston ring casting in India is Perfect Circles India Limited. The production facilities, which are situated in Nasik in Maharashtra, are made up of a casting facility, a plate plant, and a machining plant for piston rings. [1]
There are many procedures used to manufacture grey forged iron piston rings. Other ring makers cut the individual ring from pots or cuffs, whereas grey iron piston rings are produced as a single, noncircular ring [1].
Steel piston rings are constructed from a profiled wire that is originally wound into a circular shape before the gap is cut away. The required type is produced using a heat treatment procedure in which the rings are positioned on an arbor in order to impart the desired radial pressure distribution [1].
Gases from the combustion chamber were intended to leak into the crankcase through the piston/wall clearance; hence, piston rings were created to contain these gases. A single-piece copper ring with a nominal diameter 10% bigger than the cylinder bore's diameter was used by Rams Bottom to build a steam engine. When the ring was put into a piston groove, its inherent elasticity drove it up against the cylinder bore. Miller changed the design such that the inner rim of the ring could be affected by the steam pressure, increasing the sealing force [2].
Piston rings in engines are crucial because they protect the combustion chamber and reduce gas leaks into the crankcase. This not only assists in optimizing the heat transmission from the pistons to the cylinder wall but also helps in maintaining the necessary oil level, resulting in proper oil consumption and emission controls. Achieving BS-VI emission regulations becomes critically dependent on the radial thickness of such rings. The radial thickness of the rings under control in this inquiry must be kept within the predetermined range of 2.9 +/- 0.15 0.1. A narrow tolerance value must be used throughout the production process for the rings to perform as intended. The results of their investigation into the waviness and straightness of piston rings have provided detailed information on the impact of manufacturing defects [3]. An attempt has been made to reduce the rejection rate of piston rings using Six Sigma, Cost of Poor Quality, FMEA, DOE, and other techniques [4].The requirements for the piston ring as a dynamic seal for linear motion that functions under difficult temperature and chemical conditions are detailed in Piston Ring Tribology, which is discussed [5]. Depending on the application, several piston rings, including those that are chrome plated, plasma coated, plain, oil control, and scraper rings, are utilized. Several wear-resistant Mo mixed coatings for piston ring applications have been presented [6]. When using a thermal spraying technique like plasma spraying, heated and melted materials are sprayed onto a surface to create a coating. Plasma spraying is used to protect surfaces from wear, corrosion, and erosion. Metals, alloys, ceramics, composites, and other materials are used to cover the surface. When plasma is sprayed, a gas is heated to extremely high temperatures and injected through a nozzle-equipped gun as a plasma jet. After being injected into the plasma jet, the mentioned coating material melts and attaches itself to the surface it has coated [7].While thermal spraying uses a high spraying rate and deposition, plasma spraying is frequently used to enhance the surface of piston rings. A significant level of wear resistance is shown in the molybdenum coatings created by atmospheric plasma spraying [8].According to friction measurements, hydrodynamic lubrication (HL) predominated throughout the majority of the engine cycle. In 1936, they made the initial argument for the existence of hydrodynamic lubrication between a piston ring and a cylinder liner [9].Introduce piston ring analysis to the theory of hydrodynamic lubrication [10].The thickness of the oil coating and the ring's friction force were evaluated on the assumption of a symmetric parabolic curve [11].Having a ring profile with a flat centre and two circular arcs at the endpoints the proposed application of force on the piston ring in the radial direction is thought to be made up of the pressure at the ring's inner side and the elastic pressure of the piston ring [12].
Quality control is defined as an effective method for integrating the standard development, quality maintenance, and quality improvement activities of the various groups in an organization so as to modify production and repair at the top economic level, allowing for maximum client satisfaction. Perfect Circle India Limited in Nasik is the company finishing the dissertation. The casting facility, the piston ring machining plant, and the plate machining plant for Perfect Circle India are all located in Nasik, which is in the Indian state of Maharashtra. The company manufactures high-quality piston rings for a variety of markets. The corporation is concentrating on quality improvement since severe errors and their causes have become unpredictable in recent years. In the dissertation report, the cause-and-effect diagram is recommended and realistically used.
Modern manufacturing ideas focus on the requirements for a manufacturing organization to manufacture goods successfully and efficiently and are more pro-active in design. Modern manufacturing is extremely difficult, and it puts to the test a company's ability to provide in the shortest timeframe at the lowest cost without compromising the superiority of the product being produced. To operate effectively, organizations must use their resources to the best capacity possible and minimize any non-value-added operations. The important aspects, such as setup time, tool life, machine breakdown time, etc., must be managed by an organization in order to improve production capacity while also reducing waste. The essential elements impacting productivity may be found and chosen with the use of quality control technologies. A thorough investigation was required to improve the overall productivity of the various piston ring production processes.
In Nasik, Maharashtra, at Perfect Circles India Limited, the detailed work was completed. Through quality control techniques, the major objective is to reduce the defect rate for a piston ring throughout all production processes while enhancing productivity.
Quantitative tools and Total Quality Management (TQM) allow improved decision-making, better problem-solving, and even better product quality and productivity. In order to examine the main reasons for nonconformities, the fundamental causes of the quality issues, a Cause and Effect (C&E) Diagram was developed through brainstorming sessions using SPC's Seven Magnificent Techniques, the most well-liked quantitative tools.