Introduction: The following is an article on the management norms of mold design and manufacturing plants that I have carefully arranged for you, hoping to help you!
First, draw a mold diagram.
It is required to draw according to the national drawing standards, but it is also required to combine the factory standards and factory customary drawing methods that are not stipulated by the state. Before drawing the mold assembly drawing, the process drawing should be drawn, which should meet the requirements of part drawing and process data. The guaranteed dimensions of the next process shall be marked with the words "process dimensions" on the drawing. If there is no other machining except burr repair after molding, then the process drawing is exactly the same as the part drawing.
It is best to indicate the part number, name, material, material shrinkage, stretching ratio, etc. Under the flow chart. Usually, the process is drawn on the mold assembly drawing.
1. Draw the assembly structure diagram.
When drawing the assembly drawing, the ratio of 1: 1 should be adopted as far as possible, starting from the cavity, and drawing the front view and other views at the same time.
(1) The mold assembly drawing shall include the following contents:
1) Mould forming part structure
2) Structure of gating system and exhaust system.
3) parting surface and parting method.
4) Exterior structure and all connectors, positioning and guiding parts.
5) Mark the cavity height size (not required, as required) and the overall size of the mold.
6) Auxiliary tools (fetching and demoulding tools, calibration tools, etc.). ).
7) Prepare the serial numbers of all parts in sequence and fill in the detailed list.
8) Indicate the technical requirements and instructions for use.
(2) Technical requirements of the mold assembly drawing:
1) Performance requirements of some mold systems. For example, the assembly requirements of the ejection system and the slider core-pulling structure.
2) mold assembly process requirements. For example, the joint clearance of the parting surface should not be greater than the parallelism requirement of the upper and lower surfaces of the 0.05mm mold after clamping, and the size determined by assembly and the requirements for this size are pointed out.
3) Method of using, assembling and disassembling the mold.
4) Anti-oxidation treatment, mold number, lettering, marking, oil seal, storage and other requirements.
5) mold test and inspection requirements.
2. Draw all parts.
The order of drawing parts from the die assembly drawing should be: first inside and then outside, first complex and then simple, first forming parts, then structural parts.
(1) Graphic requirements: It must be drawn in proportion, and enlargement or reduction is allowed. Reasonable scene selection, correct projection and proper layout. In order to make the processing patent number easy to understand and assemble, the figure should be as consistent and clear as possible with the general assembly drawing.
(2) The dimensioning shall be unified, centralized, orderly and complete. The order of dimensioning is: first dimension the main part size and draft angle, then dimension the matching size, and then dimension all dimensions. On the drawing of non-major parts, the matching dimensions are marked first, and then all dimensions are marked.
(3) Surface roughness. Mark the most widely used roughness in the upper right corner of the drawing, such as "Other 3.2." Other roughness symbols are marked on each surface of the part.
(4) Other contents, such as part name, mold drawing number, material grade, heat treatment and hardness requirements, surface treatment, graphic proportion, free dimension machining accuracy, technical description, etc. , should be filled in correctly.
Second, proofreading, drawing review, tracing and drying
1. Self-proofreading content:
(1) Relationship between mold and parts and drawing of plastic parts
Whether the materials, hardness, dimensional accuracy and structure of molds and mold parts meet the requirements of plastic parts drawings.
(2) Plastic parts
Whether the flow, shrinkage cavity, weld mark, crack and demoulding inclination of plastic material flow affect the requirements of plastic parts in terms of performance, dimensional accuracy and surface quality. Whether the pattern design is insufficient, whether the processing is simple, and whether the shrinkage of the molding material is selected correctly.
(3) Forming equipment
Whether the injection quantity, injection pressure and clamping force are sufficient, whether there are problems in mold installation, plastic parts south core and demoulding, and whether the nozzle of the injection machine is in correct contact with the sleeve.
(4) Mold structure
1) Whether the parting surface position and finishing accuracy meet the requirements, whether there will be flash, and whether the plastic parts can stay on the side of the mold with ejector after mold opening.
2) Whether the demoulding method is correct, whether the size, position and quantity of extension rod and push tube are appropriate, whether the push plate will be stuck by the core, and whether the molded part has scratches.
3) mold temperature adjustment. Power and quantity of heaters; Whether the location, size and quantity of cooling medium streamline are appropriate.
4) How to deal with the side concave of plastic parts and whether the mechanism for removing the side concave is appropriate, such as whether the slider and push rod in the core-pulling mechanism of inclined guide pillar interfere with each other.
5) Whether the location and size of the pouring and exhaust system are appropriate.
(5) Design drawings
1) Whether the placement parts of each mold part on the assembly drawing are appropriate and clearly expressed, and whether there are any omissions.
2) The part number and name on the part drawing, the production quantity, whether the part is homemade or outsourced, whether it is standard or non-standard, the matching machining accuracy of the part, the correction machining and allowance at the high-precision dimension of the molded plastic part, and whether the material, heat treatment, surface treatment and surface finish of the mold part are clearly marked and explained.
3) Working dimensions and matching dimensions of main parts and molded parts. Size figures should be correct, don't let the manufacturer convert them.
4) Check the view position of all parts drawings and assembly drawings, whether the projection is correct, whether the drawing method meets the national drawing standards and whether there are any size omissions.
(6) check the processing performance
Are the geometric structures, views and dimensions of all parts beneficial to machining?
(7) Recalculate the main working dimensions of auxiliary tools.
1) Professional proofreading shall be conducted according to the designer's self-calibration project in principle; However, we should focus on the structural principle, process performance and operational safety.
When drawing, we must first digest the graphics, describe them according to the national standard requirements, and fill in all the dimensions and technical requirements. Self-correcting signature after tracing.
2) Submit the drawn base map to the designer for proofreading and signing. The usual practice is that the relevant technicians of the tool manufacturing unit will review, countersign and check the manufacturing manufacturability, and then send it to Sun.
(8) write the manufacturing process card
The technical personnel of the tool manufacturing unit shall compile the manufacturing process card and make good preparations for processing and manufacturing.
In the manufacturing process of mold parts, it is necessary to strengthen inspection, and the focus of inspection is dimensional accuracy. After the mold assembly is completed, the inspector will check according to the mold inspection table, mainly to check whether the performance of the mold parts is good, and only in this way can the mold manufacturing quality be guaranteed.
Third, try and repair the mould.
Although the mold design is carried out under the expected technological conditions when selecting molding materials and molding equipment, people's understanding is often imperfect, so it is necessary to conduct a mold trial test after the mold processing is completed to see how the quality of the molded parts is. It's always discovered later, and repairing the mold eliminates mistakes.
There are many kinds of bad phenomena of plastic parts, and the reasons are also very complicated, including mold reasons and process conditions, which are often only together. Before repairing the mold, we should make a detailed analysis and study according to the actual situation of the bad phenomenon of plastic parts, find out the causes of the defects of plastic parts, and then put forward the remedies. Because the molding conditions are easy to change, the general practice is to change the molding conditions first, and then consider mold repair when changing the molding conditions can't solve the problem.
Repair the mold more carefully, and you can't make a move without being quite sure. The reason is that once the mold conditions are changed, it cannot be rebuilt and restored.
Whether the performance of parts is good or not is the only way to slang the manufacturing quality of molds.
Fourth, organize the data for archiving.
After the test, if the mold is not used temporarily, the mold residue, dust, oil stains, etc. should be thoroughly removed. , coated with butter or other antirust oil or antirust agent, and stored in a storage place.
From the design of the mold to the successful processing and inspection of the mold, the technical data generated during this period, such as the task book, part drawings, technical specifications, mold assembly drawings, mold part drawings, basic drawings, mold design specifications, inspection records, mold trial repair records, etc. , according to the provisions of the system sorting, binding, filing number. This seems troublesome, but it is very useful for repairing molds and designing new molds in the future.
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