# Taking g 84 103 mpa or nmm2 we have 8 63 n 698 n 1 3

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: . Assuming the screw to be made of mild steel for which the compressive stress (σc) may be taken as 50 MPa. Let dc = Core diameter of the tappet screw. We know that load on the tappet screw (Fe), π π (d c 2 ) σ c = (d c ) 2 50 = 39.3(d c ) 2 4 4 ∴ (dc )2 = 885 / 39.3 = 22.5 or dc = 4.74 say 5 mm Ans. and outer or nominal diameter of the screw, 5 dc d = 0.84 = 0.8 = 6.25 say 6.5 mm Ans. We shall use 6.5 mm stud and it is provided with a lock nut. The diameter of the circular end of the arm (D3) and its depth (t4) is taken as twice the diameter of stud. ∴ D3 = 2 × 6.5 = 13 mm Ans. and t4 = 2 × 6.5 = 13 mm Ans. 5. Design for valve spring First of all, let us find the total load on the valve spring. We know that intial load on the spring, W1 = Initial spring force (Fs) = 48 N ...(Already calculated) and load at full lift, W2 = Full valve lift × Sitffness of spring (s) = 16 × 8 = 128 N ...(Taking s = 8 N/mm) ∴ Total load on the spring, W = W1 + W2 = 48 + 128 = 176 N Now let us find the...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online