機(jī)加工外文翻譯-刀具成本的檢測【中英文WORD】【中文8100字】,中英文WORD,中文8100字,加工,外文,翻譯,刀具,成本,檢測,中英文,WORD,中文,8100
附 錄II(外文原文)
3.5 Testing of Tool Life Cost
Machining cost is the sum of the machine tool cost and the cutter cost. The machine cost consists of idle cost, machining cost, and tool changing cost. The machining cost decreases with increased cutting speed; while the idle cost remains constant with changes in cutting speed. From the machining data handbook [24] the generalized machining cost equation is listed below:
In order to optimize the cutting condition, it is essential to determine the mathematical relationship between the cuttings inserts type and cutting speed. In our study Taylor's model will be used in relating the cutting tool life to the cutting speed:
VT" =C 3-2
V= cutting speed
T= Cutting time to produce a standard amount of flank wear (e.g. 0.2mm) n and C are constants for the material or conditions used.
In order to determine constants `n' and `C' for the cutting inserts under study in machining 4140 steel and the conditions used in the experiments, a LogV against LogT is drawn and shown for the three types of cutting inserts under study Figure 3-8A, Figure 3-8B are for KC313 under dry and wet conditions, Figure 3-9A, and Figure 3-9B are for KC732. In addition, Figure 3-10A, and Figure 3-10B are for KC5010. It can be seen from the aforementioned figures that in-spite of considerable scatter in test measurements, the results fall reasonably well on a straight line. From the curves it can be seen that for the same cutting speed the tool life increases by increasing the wear criterion and introduction of coolant emulsion for KC313 and KC732. However, as seen in KC5010 tool life increases by increasing the wear criterion and decreases by introducing coolant. This negative behavior of KC5010 toward coolant emulsion and the effect of wear mechanisms behind it will be covered in Chapter 5. As well as the wear kinds on other inserts investigated in this research.
Metal cutting studies focused on tools' wear, tool life, and wear mechanisms. However, future research should pay more attention to other factors as well:
l Wear criterion value set up by the factory system, which basically the tool wear threshold value that suits the factory product.
l Types of tools used, such as carbide tips and high speed tools. Studying the variation of tool life wear under dry and wet cutting that effect the tool life equation constants (C,n) is useful. This will improve tool life because it also affects the economy of cutting [24].
In order to determine the effect of cutting fluid on the selected wear criterion, relationship between different wear criteria and machining cost for the cutting inserts under HSM must be studied. The value of the tool life constants (C,n) for different wear criteria are extracted and plotted within the ranges listed in table (3-7). The values of the constants (C, n) extracted from Figure 3-8A/B, Figure 3-9AIB, and Figure 3-10 are shown in tables 3-8 and 3-9. Further explanation of the relationship between these parameters and wear criteria will be covered through out the next figures. Figure 3-11A represents the relationship between `n' and wear criterion. As wear criterion increase `n'.
(a) Log (time) versus Log (speed) at different wear criteria (dry condition).
(b) Log (time) versus Log (speed) at different wear criteria (wet condition)Figure
3-8 Time versus speed at different wear criteria KC313. (a) Log (time) versus Log (speed) at different wear criteri(drycondition). (b) Log (time) versus Log (speed) at different wear criteria (wet condition).
(a) Log (time) versus Log (speed) at different wear criteria (dry condition)
(b) Log (time) versus Log (speed) at different wear criteria (wet condition).
Figure 3-9 Time versus speed at different wear criteria KC732 (a)Log (time) versus Log(speed) at different wear criteria (dry condition), (b) Log (time) versus Log (speed) at different wear criteria (wet condition)
(a) Log (time) versus Log (speed) at different wear criteria (dry condition).
(b) Log (time) versus Log (speed) at different wear criteria (wet condition)
Figure 3-10 Time versus speed at different wear criteria KC5010 (a) Log (time) versus Log(speed) at different wear criteria (dry condition), (b) Log (time) versus Log (speed) at different wear criteria (wet condition).
Table 3-7 Ranges of plotted tool life constants.
Range
Cutting Insert
Condition
0 < LogT< 2.6
KC313
Dry
0< Log T< 4.1
KC313
Wet
0
收藏