Slow wire walking, also called low-speed wire walking, is a kind of CNC machining machine tool that uses continuously moving fine metal wire as an electrode to pulse spark discharge on the workpiece to generate a high temperature of over 6000 degrees, ablate metal and cut into a workpiece. The principle of wire processing is the phenomenon that there is a gap between the wire electrode and the workpiece, and the metal is removed by continuous discharge. Since the slow-moving wire cutting machine adopts the method of wire electrode continuous feeding, that is, the wire electrode is processed during the movement, so even if the wire electrode is worn out, it can be continuously supplemented, so it can improve the machining accuracy of the parts and slow the wire. The surface roughness of the workpiece processed by the cutting machine can usually reach Ra=0.8μm and above, and the roundness error, linear error and dimensional error of the slow-moving wire cutting machine are much better t
The static pressure slide rail (TTW guide) of the CNC machining lathe transfers the oil with a certain pressure through the throttle to the oil cavity between the sliding surfaces of the slide rail (TTW guide) to form a pressure oil film to float the moving parts , Make the sliding rail (TTW guide) surface in a pure liquid friction state. CNC machining General CNC machining usually refers to computer digital control precision machining, CNC machining lathe, CNC machining milling machine, CNC machining c17200 beryllium copper and milling machine, etc. The feed route of finishing is basically carried out along the part contour sequence. Therefore, the focus of determining the feed route is to determine the feed route of rough machining and idle stroke. In the numerical control processing, the control system issues instructions to make the tool perform various motions that meet the requirements, and the shape and size of the workpiece are expressed in the form of numbers and lette
Spring Design Attention And Roll Forming Method The coiling characteristics and methods of springs are divided into cold coiling method and hot coiling method. Cold winding method: When the diameter of the spring wire is less than 8mm, the cold winding method is adopted. High-quality carbon spring steel wire is usually first cold drawn and then heat treated. After winding, it is generally not quenched, but only tempered at low temperature to eliminate the internal stress during winding. Hot-rolling method: Springs with larger diameter (>8mm) spring wire should use hot-rolling method. Hot rolled springs must be quenched and tempered at medium temperature. The Design Process Of Various Springs · Installation space: When designing a compression spring , it is necessary to have a clear understanding of the space required for the installation of the spring, in order to effectively grasp the basic manufacturing conditions of the compression spring, including the outer diam
As shown in Figure 1-1, the material must be stainless steel, the material thickness must be 0.5 mm, and the dimensional accuracy of the workpiece must meet the drawing requirements. Unmarked accuracy according to IT12 level, the production program has an annual production of 100,000 pieces.
Part process analysis
The shape of the workpiece is simple, the size and thickness are modest, and it is generally mass-produced. Although it belongs to normal press parts, please note the following points when designing cold press dies.
2. The outline and structure of the part is simple, but some hole machining needs to be considered.
A, two two-hole position requirements,
B, by assembly
C, the two holes must have the same
D, shaft requirements
E, its value is 0.15 mm.
The difficulty in processing this portion is mainly the positioning of the center distance of the hole 2.
Since some holes have a small diameter and a particular batch size, the design of the mold material and structure should be emphasized to guarantee a particular mold life.
Process planning decisions
According to the analysis of the process of the workpiece, the basic process includes punching, punching and bending. There are several types of processing methods and their rational processing methods in the following order.
1, blanking-punch-bending, single process stamping.
2, blanking-bending-punch, single process stamping.
It is not suitable to adopt this method because this part has some production batch, too many steps, reduces the accuracy of the product, and the production efficiency of this method is not suitable for mass production.
Scheme 2) It is also a one-step stamping die.
In addition to the drawbacks of Method 1, it is difficult to secure the position accuracy of the holes, and it is difficult to secure the lack of positioning accuracy in bending, so it is not appropriate to adopt this method.
Scheme 3) Composite stamping die.
Due to the structure of the parts, the thickness of the material is thin, and punching and punching are completed once. Therefore, it is best to adopt this scheme. The specific plan is as follows.
Process parameter determination
1. Calculation of blank size
Calculation of external dimension length
The relative bend radii of the part are:
R / t = 2 / 0.5 = 4> 0.5
Where X is the experimentally determined strain-neutral layer displacement coefficient.
T material thickness
Apparently, for parts belonging to large bend radius members, the radius of curvature ρ of the neutral bend deformation zone should be determined.
Textbook p145 Neutral position calculation formula
Where X is the experimentally determined strain-neutral layer displacement coefficient.
Table 4-5 from p145 of the textbook takes X 0.42
Such:
ρ = R + Xt
= 2 + 0.42 × 0.5
= 2.21mm
Calculation formula for blank length of curved surface parts with large fillet radius (R> 0.5t)
L = ∑L straight + ∑L bend
L bend = [(180-a) / 180] * πρ
Therefore, the length of the part is shown in Figure 2-2.
The DE segment belongs to the process settings. The purpose is to reduce bending springback. The length of the DE segment is calculated as a straight line because it has a large radius and can be considered a straight line.
1. The width of the contour is calculated.
Considering the use of sheet materials and the convenience of layout, the process size of the work created by CAD is as follows. Outline width is L = 53.74 mm
2.Layout size calculation
Determining edge value
From Table 3-14 on page 46 of the textbook, we can see that the value of a1 between workpieces L> 50 is 2.2 * 0.8 = 1.76.
The value of side a is 2.5 * 0.8 = 2.
3. Calculate the width of the material
For convenience of mold design, the strip width calculation formula using the non-side pressure device feed method is as follows.
B = (D + 2a + Z) 0 −δ
formula
B-Basic size of strip width.
D-Maximum size of part profile in strip width direction
a –Side edge
Z—Gap between the guide plate and the widest strip
Δ—Negative deviation of strip width
Margin a is as above
Gap δ, shear tolerance Z Check textbook p47 Table 3-17 Measured value δ = 0.5mm, Z = 0.5mm
It is calculated by the above formula. B = (53.74 + 2 * 2 + 0.5> 0 –0.5 = 56.240 –0.5 mm)
Calculation step distance
Development view of parts (see Figure 2-3 on the right) Generated effective horizontal dimension Ls = 53.74mm
The formula for calculating the step interval is as follows:
L = Ls + a1
Where L is the step interval
Ls-horizontal effective size
A1-margin
L = 53.74 + 2 = 55.74mm
The nesting from which you can get the mold is:
According to the requirements, the material board specifications are 1500 x 800 x 0.5. Each board can cut 14 1500 x 56 strips with a material utilization of over 80%.
Calculate material utilization rate
Textbook p43 Style 3-19
η = nA / BL × 100%
η –About material use
A-The actual area of the blanking area within one step.
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