tailieunhanh - Volume 16 - Machining Part 15

Tham khảo tài liệu 'volume 16 - machining part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Figure 18 a shows a turning operation on a lathe. The work rotates at a certain speed VC and the tool has a depth of cut DOC and axial feed per revolution along the part. Figure 18 b shows how these are related. The three forces acting on the tool are shown in Fig. 18 a Cutting force FC The force radial or perpendicular to the work surface FR Axially the feed force Ff Figure 18 c shows how these three forces are resolved into FN a normal force. Drilling boring and milling operations can be similarly modeled. Fig. 18 Nomenclature for turning operations on a lathe. a Schematic of workpiece and tool setup. b Relation of depth of cut to axial feed per revolution and workpiece speed 1 C. c Vector diagrams of the cutting FC radial FR and feed-force Ff components that form the resultant normal force FN Figure 19 shows an external grinding system. There are two forces FN in the normal direction and FT in the tangential direction. As the slide is fed into the part at the rate I F it induces FN which causes the workpiece to be ground at a radial rate I W and the wheel to wear at a radial rate I S. Fig. 19 Schematic of an external grinding system. The terms in the schematic are used to calculate the metal removal rate ZW the wheel wear rate ZS and the power consumption. In Fig. 18 and 19 Z is a volumetric removal rate. In cutting Z is the metal removal rate calculated as shown in Fig. 18 b . For grinding ZW is the metal removal rate and ZS is the wheel wear rate. In both cases the tangential force FC or FT multiplied by the work speed in cutting VC or wheel speed in grinding VS is the power used. System Graphs Turning. Figure 20 shows turning data on 4130 steel tubing with four tools having different rake angles. Figure 20 a plots metal removal rate against the normal force and four linear relationships describe the slope. The tool with the 45 rake had a small threshold force and the steepest slope while the 25 rake tool had the largest threshold force and the shallowest .

TỪ KHÓA LIÊN QUAN
crossorigin="anonymous">
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.