Review on Design and Development of Hydraulic Fixture for Crank Case

Abstract Work holding is a critical factor in Vertical Machining Center (VMC) operations, directly determining workpiece stability, machining accuracy, and total cycle time. Conventional manual clamping methods using mechanical clamps, nuts, and bolts lead to prolonged loading, unloading, and setup times, inconsistent clamping forces, and potential workpiece deformation. This paper presents the design, development, and experimental validation of a hydraulic fixture for machining a crankcase on a VMC, carried out as an industry-sponsored project with Zanvar Group, Kolhapur. To establish a robust foundation, previous studies on hydraulic fixtures for engine components, housings, and cases were reviewed, highlighting key engineering practices such as the 3-2-1 locating principle, Finite Element Analysis (FEA), and proper hydraulic pressure selection. Analytical calculations were performed to determine cutting forces (e.g., 3000 N for face milling) and required clamping forces (45 kN for milling and 18 kN for boring across 8 cylinders), establishing working pressures of 10.7 bar and 4.2 bar respectively. The developed hydraulic fixture was successfully fabricated, assembled, and tested under industrial operating conditions. Experimental results confirmed that the hydraulic system operated smoothly without leakage, delivering effective clamping action, high fixture stability, accurate workpiece positioning, and excellent repeatability within acceptable limits. Overall, the hydraulic fixture successfully replaced manual clamping, significantly easing loading and unloading, reducing non-productive time, and fulfilling all project design requirements. Key Words: hydraulic fixture, crank case, VMC machining, finite element analysis, 3-2-1 principle, clamping force.