Described in more detail the use of CAD / CAM software for plastic mold design and NC machining of copper the public process steps and precautions. When the mold core, cavity of the structure is complicated, relatively hard material, the mold cavity or core hole on the column position, narrow trough, small rounded, complex surfaces and sharp corners, the hardness of the tool and specifications subject to size limits and other characteristics, can not use a full CNC machining allowance, you need to be processed into copper EDM public, with the EDM processing.
EDM work using the principle of electrical corrosion. Process, the copper and steel materials between the public and there is no direct processing of force, even if the holes or slots required for processing small size, depth, processing materials, high hardness, but also can be used EDM. EDM machining to improve the accuracy and efficiency of the mold, but also the complex cavity structure can be achieved. If the cavity surface roughness higher, subject to polishing process to remove the fire cavity surface pattern, the fire pattern is often used as a cavity surface of the decorative pattern.
Copper Company, also known as copper electrode, most of them use copper production. Because copper conductivity, easy processing. Sometimes often used graphite production.
one, EDM and related terminology
(1) EDM gap (spark-bit): Copper Company and the discharge gap between the steel material known as gap or EDM sparks bit. Spark bit large (usually unilateral 0.2 ~ 0.5mm), processing speed, high surface roughness, as crude public. Spark bit hours (usually unilateral 0.1mm), slow processing speed, surface roughness is low, as fine company. Hours copper finish, with a negative spark bit as allowances, crude, refined processing program the same company, just change the allowance.
(2) points in the plane: Copper for EDM to the public school level, and determine its central location and height. Irregular shape of copper on the public, to be processed in the bottom of the outer copper is used to determine the vertical datum of public center, known as points in the plane.
(3) School Surface: Copper for EDM public school level, in addition to determine its central location, also have to determine its height. The copper out of the public on the processing datum used to determine the level of depth, called the school surface (calibration standard). If the copper surface of the public's larger plane, the surface can also be used as schools.
Second, the front sole of copper after the male mold design and NC machining
1. soles of copper after the front mold design
sole public after the 3D model is shown in Figure 1. The minimum front sole radius is R1.09, and the sole design of the front in the middle of a circle at right angles to the front of the cavity can not be processed directly out of the public shall be designed copper, the electrical discharge machining.
according to the characteristics of plastic parts can be divided into the cavity after the front soles and heels of two parts, and the corresponding design of the front sole and heel of copper copper company public.
design Copper Company, in accordance with this part of the processing requirements and software features, open to all post-mold graphics layers, graphics rotate the front view 180 °, close to other layers, will fall into the latter mode 3D curved front sole copy, draw the front sole male 3D map of copper. Drawn according to processing requirements and processing the corresponding cutting curve boundary. Due process, the tool path is the maximum projection along the Z direction for processing shape, so no need to draw the public around the surface of copper. Points in the processing of surface and the school only draw 2D surface curves. Public Graphics copper complex, to facilitate the graphical management, mapping when the hierarchical management. 3D maps, processing curve and the boundary shown in Figure 2.
sole mode of copper after the origin of the coordinates and the public after the graphics-mode 3D map of the origin of coordinates do not coincide, the size shown in Figure 3, X direction offset 52.0mm, Y direction of bias Home 57.0mm. Z direction of the bottom surface of copper the public dimension of 5.2mm, after completion of processing the surface of this plane can be used as schools. XY map was drawn in the direction of the sub-surface (although curved rectangular shape than the rule, but each side has a straight line, when points can be used),Bailey UGG boots, the Z direction size of 0.2mm, Z direction after the die size and Z coordinate of the center distance is 23.0mm, EDM, need to adjust the size.
2. soles before the model after the NC Department of Public copper
(1) smooth surface transition between the rounded, smaller radius. Surface around the taper. When processing the sharp four-blade cutter with a reasonable set processing parameters.
(2) the copper is at the top notch company, processing and clear the corner to use knife and processing, to take the appropriate numerical techniques.
(3) the top surface in order to obtain better surface roughness, surface finish, it should be the boundary change process, and change the angle of the tool path.
(4) due to large size parts, from the perspective of processing costs, processing only a fine company (discharge gap 0.1mm). EDM, the loss will be great, to control the discharge current.
NC before a saw saw a 118mm × 80mm × 40mm rough copper company. Used in the vise clamping on a CNC milling machine processing. Machining tool path is as follows.
1) Φ16 selected four blade flat white blades, and select the Figure 2 in the front sole public appearance for the processing of copper boundary, with the 2D shape processing tool path shape on the surface of copper roughing the public, XY direction The allowance is 0.3mm, Z direction of the allowance is 0.1mm.
2) continue to select four edge Φ16 flat white blades, and select the sole Figure 2 cm in front of the form for the processing of copper boundary, with the 2D shape of the tool path for copper processing company in the shape of the rough sub- , XY direction of the allowance for the 0.2mm, Z direction of the allowance is 0.0mm.
3) soft copper material, selected four-blade white Φ16 flat blades, and finishing with a surface of copper roughing tool path parallel to the public milling surface. Allowance for the 0.2mm.
4) renewal of the Φ16 flat white Gangdao, select Figure 2, the public profile for the processing of copper boundary, with the 2D shape of the copper processing tool path for finishing the public of the surface shape, and surface finishing school platform. XY direction of the allowance is-0.1mm, Z direction of the allowance is 0.0mm.
5) Select the Φ16 flat white blades, and selected in Figure 2 cm in the form of copper for the processing of the border, with the 2D shape of the tool path processing of copper in the shape of the public for finishing the sub, XYZ direction of the processing of more than volume of 0.0mm.
6) to select the Φ16 flat white blades, and finishing with a 2D chamfer tool path of copper in the middle of the public trough. Allowance to-0.1mm.
7) continue to select Φ10R5 ball-end cutters, milling with a surface finishing tool path parallel to the front of the semi-finished copper sole public. Allowance for the 0.1mm, feed step to take 0.4mm, processing angle of 45 °.
8) Select Φ6 flat white blades, and were selected in Figure 2 for the processing of clearing the boundary angle curve, with the 3D shape processing tool path, respectively, the middle of the copper surface of the front of the public were rough, XY direction allowance for the 0.3mm, Z direction allowance is 0.0mm.
9) Select Φ4 flat white blades, and were selected in Figure 2 for the processing of clearing the boundary angle curve, with the 3D shape processing tool path, respectively, among the public on the copper surface for finishing the front, XY direction allowance to-0.1mm (discharge gap), Z direction allowance is 0.3mm (protection of processed bottom)
10) Select Φ6R3 ball-end cutters, were selected in Figure 2 Chain1 ~ Chain4 for the processing of the border, transformation processing point of view, with a surface finish milling tool path parallel to the front of the copper soles were male finishing lower right, upper right and upper left, bottom left of the surface. Allowance to-0.1mm.
the front of the sole mode of copper after the public entity processing simulation results shown in Figure 4.
three copper soles heels after the male mold design and NC machining
1. soles heels after the copper mold design
sole public Die heel after the shape is rather special, is the depth of 65mm in the narrow groove, the minimum radius of 1.09, and the heel of the bottom and side surfaces intersecting at right angles, can not be processed after the mold cavity from the heel to be Copper for EDM machining company.
design Copper Company, in accordance with this part of the processing requirements and software features, open to all post-mold graphics layers, graphics rotate the front view 180 °, close to other layers, from the front heel the sole truncated, will belong to the heel of the 3D model surface after the copy, draw the public's 3D map of copper heel, and drawing according to processing requirements and processing the corresponding cutting curve boundary. Due process, the tool path is the maximum projection along the Z direction for processing shape, so no need to draw the public around the copper surface below.
copper complex graphics company, for ease of graphical management, mapping when the hierarchical management. 3D shown in Figure 5, processing and boundary curve shown in Figure 5. Die heel after the origin of the coordinates of copper and the public after the graphics mode of the 3D map of the origin of coordinates do not coincide, the size relationship shown in Figure 3 and Figure 6, X direction offset 80.0mm, Y direction offset 75.0mm. Public profile curve of copper surface Z-direction size of-28.0mm, after completion of processing the surface of this plane can be used as schools. At the same time carved in the shape of the graph drawn as points in the XY plane direction, the direction of the Z dimension of 34.0mm, the sole public schools of copper surface after the die size and the direction Z, Z coordinate of center distance-28.0mm, EDM adjust this size is required.
2. soles heels copper mold the public after the NC
(1) Public heel copper surface smooth transition between the rounded corners, smaller radius. Copper Public depth, the surface around the taper. Processing extension to use the sharp four-blade cutter, a reasonable processing parameters set to prevent shells knife.
(2) after the NC model, it is already used as much as possible and clear the angle of the tool Φ8mm processing, reducing the amount of electrical discharge machining, and the accuracy requirements Xiemo lower processing costs from both point of view, only a fine public process (discharge gap 0.1mm), processing power, the loss will be great, to control the discharge current.
(3) the public side of this copper is a semi-open groove, the groove bottom of the processing can easily play the knife, to take the appropriate CNC technology.
(4) around the surface to obtain better surface roughness, finishing around the surface, they should choose a different diameter ball-end cutters, the boundary change process, and change the angle of the tool path.
NC before a saw saw a 65mm × 65mm × 90mm rough copper company. Used in the vise clamping on a CNC milling machine processing. Machining tool path is as follows.
1) Select the Φ16 flat four white steel knife edge, chamfer tool path with a 3D surface model of the heel after the rough surface of copper the public. Depth of processing defined in the -22.38 ~ 41.0mm, allowance 0.35mm.
2) because the heel half of copper within the public is more narrow and deep groove, fillet radius of R1.89, precision machining allowance to reduce the back and continue to select four edge Φ16 flat white blades, and with 3D chamfer tool path on the copper surface within public and semi-open slot roughing. Depth of processing is defined in 4.0 ~ 5.7mm, Z direction for the next step knife 0.1mm, allowance 0.35mm.
3) Select Φ16 flat four-blade white blades, and select the profile curve in Figure 5 in the heel, with the 2D shape processing tool path shape on the surface of copper roughing the public, has been the location of the surface processing to the school ( Z-28), XY direction of the allowance for the 0.35mm, Z direction of the allowance is 0.1mm.
4) continue to select four edge Φ16 flat white blades, and select the points in Figure 5, shape, machining tool path with the 2D shape of copper in the form of public sub-roughing, XY direction of the allowance to 0.2mm, Z direction allowance is 0.0mm.
5) soft copper material, select Φ16 flat four-blade white blades, shape of the tool path with a high copper on the soles of all public and semi-finished surface, depth of processing defined in the -22.38 ~ 41.0mm, allowance 0.2mm. Allowance for the 0.1mm.
6) for the new four-edge white Φ16 flat blades, and select the shape of the heel in Figure 5 curve shape with a 2D tool path for copper processing company for finishing the surface shape, and surface finishing school platform. XY direction of the allowance is-0.1mm, Z direction of the allowance is 0.0mm.
7) Select Φ16 flat four-blade white blades, and select the points in Figure 5, shape, machining tool path with the 2D shape the public's point of copper in the shape of the finishing, XYZ direction of the allowance for the 0.0mm.
8) Select the Φ16 flat four-blade white blades, and select the top curve in Figure 5, with the 2D shape processing tool path on the top surface of copper for finishing company, XYZ direction of the allowance for the 0.0mm.
9) Select Φ12R6 two ball blade knife, were selected in Figure 5, the boundary drawn by the processing, conversion processing point of view, with a surface finish milling tool path parallel to copper, respectively, finishing the public right side of the heel upper right, lower right and upper left, bottom left. Allowance to-0.1mm.
10) to select the Φ12R6 ball-end cutters, were selected in Figure 5, the boundary drawn by the processing, conversion processing point of view, in parallel with the surface finishing copper milling tool path finishing heel left side of the top left of public and the upper right. Allowance to-0.1mm.
11) Select Φ6R3 ball-end cutters, were selected in Figure 5, the boundary drawn by the processing, conversion processing point of view, with a surface finish milling tool path parallel to the public related to finishing the heel area copper finish. Depth of processing defined in the 0.0 ~ 40.0mm, allowance is-0.1mm. Die heel after
sole public entity copper processing simulation results shown in Figure 7.
Fourth, the design considerations when copper company
(1) design the overall copper company. To split the overall copper company, and try to split. But the need to consider the feasibility of processing as much as possible to complete processing of a process,cheap UGG boots, not a process completed processing, split into multiple copper company.
(2) demolition of dispersed copper company. After the split must be processed, processing difficulties and sometimes the whole copper company, with processing not the dead, or is not processed, the required tool is too long or too small to be considered more of a copper company split, and sometimes need to clear the local angle Copper Company, this copper processing company is not difficult, but be sure to find out when sparks hit the partial number and calibration benchmarks.
(3) split bone-bit Copper Company. To increase the strength of plastic products designed for thin sheet structures called bone bits. Both narrow and deep bone bit difficult to be directly processed out, are generally required to design bone-bit Copper Company.
(4) demolition of the public to be set into a good piece of copper to carefully check for interference, and the symmetry of the copper near the public to check whether the split is reasonable, pan or rotate out of the copper from the public to check the translation and rotation central point is correct.
(5) Public split design of copper, it is recommended not to easily change the coordinate system of copper company, the assembled company split copper, a copper company a drawing, you can use to distinguish between layers of copper company.
(6) To facilitate identification basis, copper is usually taken three public and rounded base and a bevel, bevel aligned base mold cavity, copper number of public centers to take on the mold cavity in the base integer.
(7) public and try not to separate the copper removed, saving material and discharge time, processing difficulties, can be used with the line cleared corner cutting or engraving machine.
(8) large gap between the level of the public to try to split multiple copper copper company, copper company in order to save material.
(9) symmetrical with the copper to shift the public often do the number of processing, the shape similar to the public should pay attention to differences between the copper (such as a bevel or more rounded).
(10) is often determined by the appearance of the product requirements of crude, refined public. Sometimes in order to save copper materials, copper company is finished, the copper surface down to reduce the public's overall design, precision milling copper company, then the EDM finishing.
five copper processing company Precautions
(1) copper processing company shall, before the tool used to check the processing is complete, clamping length of the compliance. Copper material is relatively soft, easy to process and take the knife speed is higher. To ensure the quality of surface processing, processing to make a new knife.
(2) copper processing tool path of public order in general: large diameter, small diameter cutter knife → roughing roughing and cleaning of large diameter blade angle → finishing → small-diameter ball-end cutter knife clearance angle and finishing surface.
(3) Rough Copper Company, the allowance is generally 0.2 ~ 0.5mm. Finishing, the tolerance of 0.005 ~ 0.02mm. Step away from the value of 0.05 ~ 0.3mm, allowance is -0.3 ~-0.1mm.
(4) the outer surface of plastic products often have a narrow groove and boss appears, by the tool length and diameter and other characteristics of the restrictions, the public processing of copper, the surface will appear salvage can not be cleared of the dead, not easy to process. Such cases there can be hand-finishing, precision demanding or difficult to hand-finishing, it can be considered a portion of the copper cm,UGG shoes, dismantled and then be separated.
(5) bits of bone easily deformed copper processing company, processing and use the new tool, select small-diameter tool, set the smaller feed rate. The direction of processing numerical processing of first place, to stay a little cushion thickness (eg 1.0mm), the first processing side, and then processing the other side. Feed depth is 0.2 ~ 1mm, feed depth should not be too large, it can not take the knife around the entire contour.
(6) ball-end cutters in the shape of the tool path contour, the tool is calculated on the basis of the spherical front, the lowest tooling to the wall position, the ball knife over the top of the depth of Z-axis surface to be machined a tool radius, such as when the first knife Road rough machining depth will not increase, the ball will appear when processing step knife blade, spring knife phenomenon, processing After the surface is not smooth, size is not accurate, as over Tool shown in Figure 8. When the solution is to increase the depth of processing rough to increase the depth of more than a ball cutter radius, and then the next step processing.
(7) Copper Company set the spark gap: Copper spark gap determines the size of the public the mold cavity surface roughness, set the spark gap must be considered when the residual amount of workpiece, the amount determined under the residual workpiece is the fine or coarse the public company. Fine for the general public and 0.05 ~ 0.15mm, rough public is 0.2 ~ 0.5mm.
(8) spark gap method used to set the following: 1) the margin placed spark gap, that is, programming, machining allowance set by changing the discharge gap; 2) assume that the tool put spark gap, that is, change the size by setting tool to set the discharge gap;
3) put spark gap is too small, the copper company in proportion to the scale graphics; 4) face milling bottom (or top), because the negative can not be set The allowance, often reducing knife Road Z-axis offset; 5) flat blade can not be set negative margin, then can be set off knife (about flat fillet knife set R).
(9) the public should pay attention to copper surface where the transition is the transition smoothly. After the inspection process and some of Intersection ridge Qing Qing is a good local angle angle. Provincial mold due to the existence of the ridge caused subsidence fuzzy and distorted and so on. Special attention must be rounded and smooth the transition position round. Check whether the surface of copper Public defects such as trachoma, or bumps, if necessary,UGG bailey button, need to redo the copper company.
(10) plastic mold will often design a mold out of two parts, left and right pieces of copper for the public, through the mirror to produce graphics. If the two identical parts, the graphics must be said in the translation or rotation within the XY can not mirror.
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