Refers to the processing of forming and billet making tools, in addition to shear molds and die-cutting molds. Usually, the mold consists of two parts: the upper mold and the lower mold. Place the steel plate between the upper and lower molds to form the material under the action of a press. When the press is opened, the workpiece determined by the mold shape will be obtained or the corresponding waste will be removed. Workpieces from electronic connectors to automotive dashboards can be molded using molds.

Progressive mold refers to a set of molds that can automatically move the processed workpiece from one workstation to another and obtain the formed part in the last workstation. The mold processing technology includes: cutting die, punching die, composite die, extrusion die, four slide rail die, progressive die, stamping die, die cutting die, etc.

Mold type

(1) Metal stamping molds: continuous die, single die, composite die, and drawing die

(2) Plastic forming molds: injection molds, extrusion molds, and suction molds

(3) Die-casting mold

(4) Forging mold

(5) Powder metallurgy mold

(6) Rubber mold

Mold Price Process

Material opening: front mold material, rear mold material, insert material, row position material, and inclined top material;

Opening frame: front mold frame, rear mold frame;

Opening thickness: opening thickness of the front mold cavity, opening thickness of the rear mold cavity, and opening thickness of the parting line;

Copper male: front mold copper male, rear mold copper male, parting line clear angle copper male;

Wire cutting: Insert parting line, copper male, inclined top pillow position;

Computer gong: precision gong parting line, precision gong rear mold core;

Electric spark: front mold coarse, copper male, male mold line clear angle, rear mold bone position, pillow position;

Drill holes, pinholes, and thimbles; Processing line position and line position pressure pole for the top needle hole and waterway hole of the mold;

Oblique top, double top needle, with top needle.

other

(1) Chui, code mold pit, garbage nail (limit nail);

(2) Flying mold;

(3) Water inlet, support head, spring, water transport;

(4) Saving mold, polishing, front mold, and back mold bone positions;

(5) Fine water structure, pull rod screw hook, spring

(6) Heat treatment, quenching, and surface nitriding of important components;

Mold software

UGNX, Pro/NC, CATIA, MasterCAM, SurfCAM, TopSolid CAM, SPACE-E, CAMWORKS, WorkNC, TEBIS, HyperMILL, Powermill, GibbsCAM, FEATURECAM, and more.

Basic characteristics

(1) A mold with high machining accuracy requirements is generally composed of a concave mold, a convex mold, and a mold base, and some may also be a multi piece assembly module. Therefore, the combination of upper and lower molds, the combination of inserts and cavities, and the assembly between modules all require high machining accuracy. The dimensional accuracy of precision molds often reaches μ M-level.

(2) Some products, such as automotive panels, aircraft parts, toys, and household appliances, have complex shapes and surfaces, resulting in complex mold cavity surfaces. Some surfaces must be processed using mathematical calculations.

(3) The production of small molds in bulk is not mass production, and in many cases, only one batch is produced.

(4) In multi process mold processing, various processes such as milling, boring, drilling, reaming, and threading are always used.

(5) The use of repetitive production molds has a lifespan. When a mold exceeds its lifespan, it needs to be replaced with a new mold, so the production of the mold often has repeatability.

(6) In the production of profiling processing molds, there are sometimes no drawings or data, and profiling processing needs to be carried out based on the actual object. This requires high imitation accuracy and no deformation.

(7) The die material is excellent, and the main material of the die with high hardness is mostly made of high-quality alloy steel, especially the die with long life, which is often made of ledeburite steel such as Crl2, CrWMn, etc. This type of steel has strict requirements from rough forging, processing to heat treatment. Therefore, the compilation of processing technology cannot be ignored, and heat treatment deformation is also a problem that needs to be taken seriously in processing.

Based on the above many characteristics, it is necessary to meet the processing requirements as much as possible when selecting machine tools. For example, CNC systems need to have strong functionality, high machine tool accuracy, good rigidity, good thermal stability, and have profiling functions.

Processing process arrangement

(1) Bottom processing, ensuring processing quantity;

(2) Align the casting blank benchmark and check the 2D and 3D mold surface allowance;

(3) 2D and 3D surface rough machining, non installation and non working plane machining (including safety platform surface, buffer installation surface, pressing plate surface, and side reference surface);

(4) Before semi precision machining, ensure the accuracy of the side reference plane alignment;

(5) Semi precision machining of 2D and 3D profiles, precision machining of various installation working surfaces (including limit block installation surface and contact surface, insert installation surface and back surface, punch installation surface, waste cutting tool installation surface and back surface, spring installation surface and contact surface, various travel limit working surfaces, wedge installation surface and back surface), semi precision machining of various guide surfaces and guide holes, leaving allowance for precision machining process reference holes and height reference surfaces, and recording data;

(6) Inspect and recheck the machining accuracy;

(7) Fitter inlay process;

(8) Before precision machining, align the reference surface of the process reference hole and check the allowance of the insert block;

(9) Finish machining surface 2D and 3D, side punching surface and hole location, precision machining process reference hole and height reference, precision machining guide surface and guide hole;

(10) Inspect and recheck the machining accuracy.

matters needing attention

(1) The process preparation should be concise and expressed in detail, and the processing content should be expressed numerically as much as possible;

(2) Special emphasis should be placed on the key and difficult points of processing, as well as the process;

(3) Need to combine processing areas and express the process clearly;

(4) When the insert needs to be processed separately, pay attention to the process requirements for processing accuracy;

(5) After combined processing, the insert parts that need to be processed separately shall meet the benchmark requirements for separate processing during combined processing;

(6) Springs are the most easily damaged in mold processing, so it is necessary to choose mold springs with long fatigue life.

Large mold processing issues

Huge size and weight

How to cope with the huge size and weight of large molds during processing is a major challenge faced by processing enterprises. The processing of large molds often requires a large amount of labor, specialized equipment, and multiple adjustments and fixtures, and the processing accuracy is also affected by various potential factors and is not easily guaranteed.

Acquisition cost issue

The biggest cost directly related to the processing and production of various large molds is the purchase cost of machine tools. Machine tools that can produce large molds are quite expensive, especially in complex process arrangements where multiple machines are required to complete the entire process from rough machining to precision machining of molds. Such high initial investment costs are also the biggest obstacle for many enterprises to enter this market. From this, we can see that if rough and precision machining of large molds can be achieved on a suitable machine tool, and even with just one debugging and clamping, many problems will be easily solved and machining accuracy can be guaranteed.

The machining center has a cast iron bed structure, and the machine tool spindle has heat dissipation function

Cast iron material has high rigidity and heat dissipation characteristics, making it the most stable material for manufacturing machine tool structural components. For any machine tool used for milling large parts, it is first necessary to have a very sturdy cast iron structure and be equipped with a spindle with heat dissipation function.

As for the spindle of the machine tool, it must adopt built-in cooling technology to cool the spindle from outside the bearing, ensuring that the spindle itself will not be burnt out or cause accuracy loss due to thermal expansion during long-term processing. These factors are very important because the processing of large molds requires a long time, and under heavy cutting conditions, this increases the heat and stress of the mold. Therefore, the structural components of the machine tool must have good rigidity and heat dissipation characteristics, which is a prerequisite for producing large and high-quality molds. Therefore, it is necessary to minimize the vibration of the machine tool during the machining process and quickly diffuse the heat generated during the machining process. Choosing the appropriate machining machine and tools can achieve a win-win situation in terms of cost and cycle.

Thermal stability technology

Due to the long processing time, the impact of environmental temperature must also be considered. For example, when processing large molds on ordinary machine tools, a 10 ℃ temperature change in the environment will cause a 6 ℃ temperature change in the machine tool column, resulting in a 0.07mm change in the parallelism of the spindle angle plate. Therefore, the design of machine tools must consider the effect of environmental temperature to avoid the impact of environmental temperature on the accuracy of processed parts.

speed

For a large mold machining center with fast travel, the spindle speed of the large mold machining machine should reach at least 20000 r/min, and the metal cutting speed should meet 762-20000 mm/min.

accuracy

Precision control always runs through all stages of mold processing. If it is necessary to achieve rough and precision machining of large molds on a machining center, then the positioning accuracy and repeated positioning accuracy of the machine tool must be strictly controlled. A specialized machining center for large molds, usually with a positioning accuracy of ± 1.5 μ m. The repeated positioning accuracy should reach ± 1 μ m。 Meanwhile, its pitch accuracy should be maintained at 5 μ Within m.

Feedback resolution

For high-precision surface machining, the feedback resolution of the machine tool itself is crucial for detecting the accuracy of the machined parts. Adopting standard 1 μ The feedback resolution of m is usually not very ideal. If the resolution can reach 0.05 μ m. So its precision machining results are almost flawless. Moreover, by controlling the machine tool resolution, ruler feedback, and pitch ball screw, the machining quality of the part surface can be further improved.

principal axis

The spindle used on large mold machining centers must meet the requirements for rough machining, semi precision machining, and high-quality precision machining, and as a reference standard, the surface machining quality it can achieve should be controlled at 2 μ The level of m. Usually, precision machining of the closed surface and parting line of the mold is very important, but in traditional processes, many mold manufacturers have to use manual polishing to compensate for the problem of insufficient tool machining accuracy. Because the cost of large-scale machining machines is expensive, it is obviously impractical to purchase multifunctional machine tools for this process.

In addition, a reasonable spindle design must be able to maximize the service life of the cutting tool, enabling it to continue working in a low vibration and low temperature rise state during the machining cycle. For example, when machining automotive dashboard molds on a large mold processing center, if a 16mm CBN insert blade precision machining tool is used, the processing speed can reach 8m/min, the service life exceeds 30 hours, and the surface quality of the machining can be controlled between 0.336 and 3.2 μ m。 From this, it can be seen that considering the increase in tool costs when processing large molds, using specially designed large mold processing machines can not only extend the tool service life, but also greatly save the tool usage cost for processing each mold.

Movable multi axis machining head

Due to limitations in mold size and weight, it usually takes a long time to clamp the workpiece. Therefore, using a 3-axis linkage machining center not only reduces the number of debugging and clamping times for the workpiece, but also does not affect the machining accuracy of the machine tool, thereby greatly improving the production capacity of the workshop for processing large molds.

A movable multi axis machining head can be used to process large molds with particularly complex structures. The machining head designed according to variable geometric shapes allows for 3-axis linkage machining. With only one clamping of the workpiece, it can mill deep molds and cooling holes in the machining cavity, as well as cut and process many other geometrically complex parts. For example, when the spindle is tilted at the optimal angle, the proximity of the machining head to the milling points can be improved, which enables the use of multi axis machining heads to complete the machining of oblique holes.

In addition, due to the use of the radius blade of the tool rather than the tip of the tool when processing the surface of the workpiece with a multi axis machining head, surface roughness can be improved.

Chip management

During metal cutting, a large amount of chips will be generated. If not eliminated in a timely manner, it will inevitably lead to secondary cutting and temperature rise of machine tool structural components or workpiece surfaces. The workbench of a large mold processing center usually has 18 chip removal holes under it, which can reliably remove chips no matter where the workbench is moved. There are 4 built-in hinge type chip conveyor belts on the machine tool, which discharge chips to the front of the machine tool at a high speed.

High pressure coolant

High pressure coolant plays a very important role in the processing of large molds. For example, when using the 2+3 axis machining method to drill inclined holes, a coolant with a pressure of 1000psi (1psi=6890Pa) is required to effectively remove chips and achieve higher precision cutting. If there is no such high-pressure coolant, additional machine tools need to be added during the processing of inclined holes, requiring secondary clamping, reducing machining accuracy, and increasing cycle costs. Based on the above analysis, it can be seen that achieving simple processing of large molds requires the machine tool to have more and better functions.

The new MCC2516VG3 axis horizontal machining center developed by Makino has a spindle speed of up to 15000 r/min, and adopts a "shaft core cooling" method and a "bearing internal pressure lubrication" function to ensure timely and effective cooling of the spindle and its auxiliary bearings.

In addition, the spindle can not only move along the horizontal X-axis, vertical Y-axis, and front and rear Z-axis directions, but also rotate in conjunction with the A-axis and C-axis. Due to its two indexing functions, it not only reduces the amount of adjustment work, but also allows for cutting complex workpieces such as bumpers, instrument panels, and car headlight lenses.