tailieunhanh - Engineering Drawing for Manufacture phần 4

Thay vào đó, phải đối mặt với trở lại hình chữ nhật CDEF và đối mặt với ABCF dưới được hiển thị. Dựa trên hai hình chữ nhật, phương pháp xây dựng như sau. Hai hình dạng được vẽ trên CDEE máy bay trở lại phương Đây là những cơ sở các tấm hình chữ nhật CPQF và các vòng tròn phương trong kèm theo hình vuông Thép Việt Nam. | ISO drawing rules 4b Item List TO Plate Screw 9 Plate 8 4 insert Screws 7 Tommy Bar 6 1 Jaw Clamp Screw 5 1 Bush Screw 4 1 Bush 3 1 Movable Jaw _2_ 2 Hardened Inserts 1 1 Body Part NPi No. Description Figure Assembly engineering drawing of a small hand vice Figure is a third-angle orthographic projection detail drawing of the movable jaw part number 3 . It gives all the information necessary for the part to be manufactured. The outline is drawn in thick or wide lines whereas additional information . hidden detail or section hatching is drawn in thin or narrow lines. The thick lines are deliberately drawn so that shape and form jump out of the picture. With regard to the front elevation the equals sign at either end of the centre line shows that it is symmetrical about that centre line. The 16mm wide tongue is thus centrally positioned in the front elevation and there is no need to dimension its position from either side. There are further outcomes from this symmetry. Firstly both underside surfaces that contact the body as shown by thick chain dotted lines are to be polished such that the average surface finish Ra is less than 0 2um. Secondly the counter-bored 5mm diameter holes are identical. The right-hand elevation is a section through the centre of the jaw but nothing tells you this. This is the designer s decision of how much to include in the drawing called draughtsman s licence . The side elevation shows that there is a vertical threaded hole in the base. The various 46 Engineering drawing for manufacture line thicknesses of the threaded hole show that the initial hole is to be drilled note the conical end and then threaded to M8. The M8 means that it is a metric standard 8mm diameter thread. The designation M8 is all that needs to be stated since full details of the thread form and shape are given in ISO 68-1 1998. The xlO 12 means that the drilled hole is 12mm long and the thread is 10mm long. The right-hand side elevation section also indicates