1. Traditional theoretical mold matching method (C method matching mold)
★Symbol definition and related formulas
In the past, the definition of the symbol started from the incoming line, here for the convenience of computer calculation (using the Execl spreadsheet). Just the opposite.
1. The aperture of each mold: (export mold) d1, d2, d3...dn....
2. The elongation coefficient of each pass: (starting from the constant speed roller) μ1, μ2, μ3...μn...
3. The speed increase ratio of each tower wheel: (starting from the fixed speed roller) ν1ν2ν3...νn...
4. Sliding coefficient of each channel: τ1τ2τ3....τn...
5. Absolute (cumulative) sliding coefficient of the nth tower wheel: Τn=Vn/Un
6. The linear velocity of the nth tower wheel: Vn
7. The speed of the copper wire on the nth tower wheel: Un
8. μn=νn*τn
9.√
The following takes the 17-die wire drawing machine as an example to illustrate the die matching calculation method:
A. Determine the mechanical parameters of the wire drawing machine:
Each wire drawing machine manual has equipment parameters, mechanical elongation (or different name), that is, the speed increase ratio of adjacent tower wheels of the wire drawing machine. Some manuals have instructions for calculation. The speed increase ratio of the 17-die wire drawing machine is:
1.20:1, (the last one: 1.15:1), namely: νn=1.2
B. Sliding coefficient τn:
Middle drawing machine generally takes: 1.02-1.04, take τn=1.03
C. Calculate the extension coefficient of the wire: μn=νn*τn=1.2*1.03=1.236
D. Determine the specifications of incoming and outgoing wires: incoming wire: 2.80; outgoing wire: 1.00
E. Model matching calculation
1.0-1.112-1.236-1.374-1.528-1.698-1.888-2.099-2.334-2.595-2.800
2. New theory mould matching method (X method matching mould)
★The basis of the new theory of mold matching:
The basis of low-slip cable is that it is safe (continuously) and smoothly (continuously) to pull the cable, and the slip can be minimized. Therefore, the minimum specification requirements for sliding coefficient:
1. τ3-τn is required to be 1.0-1.01, and the average value is 1.005 in the calculation of mold matching
2. Safety sliding coefficient τ2
The method to determine the safe sliding coefficient τ2 is introduced here. The 17-die wire drawing machine has a structure that satisfies the performance of low-sliding wire drawing. The safe sliding coefficient is achieved by reducing the speed increase ratio of the last tower wheel. Therefore, the safety sliding coefficient τ2=(1.2/1.15)*1.005=1.049.
Such as: 17-die wire drawing machine safety sliding coefficient τ2=(1.2/1.15)*1.005=1.049;
The safety sliding coefficient τ2=(1.175/1.15)*1.005=1.027 designed for the B22 wire drawing machine;
B32 wire drawing machine safety sliding coefficient τ2=(1.15/1.12)*1.005=1.032;
S20 wire drawing machine safety sliding coefficient τ2=(1.12/1.08)*1.005=1.042;
S24 wire drawing machine safety sliding coefficient τ2=(1.1/1.08)*1.005=1.024.
A. Determine the mechanical parameters of the wire drawing machine:
Each drawing machine manual has equipment parameters, mechanical elongation (or different name), that is, the ratio of the growth rate of adjacent tower wheels of the drawing machine, and some manuals have instructions for calculation. The speed increase ratio of the 17-die wire drawing machine is:
1.20:1, (the last one: 1.15:1), that is: νn=1.2
B. Sliding factor:
1.τ3-τn is 1.005
2. Safety sliding coefficient τ2=(1.2/1.15)*1.005=1.049
C. Calculate the extension coefficient of the wire: μ1=ν1*τ2=1.15*1.049=1.206
μn=1.2*1.005=1.206
D. Determine the specifications of incoming and outgoing wires: incoming wire: 2.80; outgoing wire: 1.00
E. Modulation calculation: dn=dn-1*√μn (1.00-1.098-1.206-1.325-1.455-1.597-1.754-1.927-2.116-2.323-2.552-2.800)
Third, use the absolute sliding coefficient to match the method
★The basis of mould matching using absolute sliding coefficient:
The wire drawing machine continuously draws the wire, the wire is on each tower wheel, and the volume per unit time is equal.
That is U1*S1=Un*Sn (U1: the speed of the wire on the fixed-speed wheel, S1: the cross-sectional area of the wire on the fixed-speed wheel)
Then
Τn=Vn/Un
Un=Vn/Tn, U1=V1
Suppose: absolute speed ratio Kn=V1/Vn
To
Safety sliding coefficient Τ2=τ2; the remaining Τ3=Τ2+0.001...Τn=Τn-1+0.001
A. Determine the mechanical parameters of the wire drawing machine:
Each drawing machine manual has equipment parameters, mechanical elongation (or different name), that is, the ratio of the growth rate of adjacent tower wheels of the drawing machine, and some manuals have instructions for calculation. The speed increase ratio of the 17-die wire drawing machine is:
1.20:1, (the last one: 1.15:1).
B. Sliding factor:
1. Safety sliding factor Τ2=τ2=(1.2/1.15)*1.005=1.049.
2. Τ3-Τn takes: Τ3=Τ2+0.001....Τn=Τn-1+0.001 (when piercing the mold, leave the relative sliding amount)
C. Determine the specifications of incoming and outgoing wires: incoming wire: 2.80; outgoing wire: 1.00
D. Calculation of die matching:
1. First assume that V1 of the fixed-speed wheel is 1000, and calculate Vn by using the speed increase ratio of the adjacent tower wheels of the machine
2. Through the absolute speed ratio Kn=V1/Vn, then calculate Kn
3. Calculate the specifications of each mold through dn=d1×√Kn*Τn. (It is very convenient to actually use EXCEL)
(1.00-1.098-1.204-1.319-1.446-1.585-1.737-1.903-2.086-2.286-2.506-2.746-2.800)
4. Concluding remarks:
Through the comparison of the above three mold matching methods, the low-sliding cable has a great advantage in terms of energy saving. In addition, the loss of drawing oil is reduced, the life of the tower wheel is prolonged, and the comprehensive benefits are obvious. The three mold matching methods are selected reasonably according to local conditions and according to the technical level and management level.
The three matching methods have their own characteristics (can't say that the kind is bad). Method C does not have strict requirements for equipment and molds; Method X and J have high requirements for equipment accuracy, strict requirements for mold tolerances, and high operator requirements. The combination of the X method and the series of molds has a better effect.
In order to achieve good results with low sliding cable and energy saving, it is also important to use molds and lubrication systems. Only by improving in many aspects can the production level and technical level be improved, and the company can rise to a higher level as a whole, and finally achieve the goal of energy saving.
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