First, draw a mold diagram
Before drawing the mold assembly drawing, the process drawing shall be drawn and shall comply with the requirements of the parts drawing and the process data. The dimensions guaranteed by the next process shall be marked on the drawing with the words “process size”. If after molding, In addition to repairing burrs, no other machining operations are performed, so the process diagram is exactly the same as the workpiece drawing.
Under the process chart, it is better to mark the part number, name, material, material shrinkage ratio, draw ratio, etc. Usually, the process drawing is displayed on the mold assembly drawing.
Draw the assembly drawing as much as possible with a ratio of 1:1, starting with the cavity and drawing the main view at the same time as the other views.
The mold assembly drawing should include the following:
Molding part structure
Casting system, exhaust system structure.
Sub-surface and sub-module take way.
Shape structure and all connections, positioning, position of the guide.
Mark the height dimension of the cavity (not required, as required) and overall dimensions of the mold.
Auxiliary tools (removal mold release tools, calibration tools, etc.).
All the part numbers are listed in order and fill in the schedule.
Labeling technical requirements and instructions.
Technical requirements for mold assembly drawings:
The performance requirements for certain systems of the mold. For example, for the ejector system, assembly requirements for the slider cored structure.
The requirements of the mold assembly process. For example, the fitting gap of the bonding surface of the parting surface after mold assembly should not exceed 0.05mm on the mold, the following parallelism requirements, and the size determined by the assembly and the requirements for the size.
Mold use, assembly and disassembly method.
Anti-oxidation treatment, mold numbering, lettering, marking, oil seal, storage and other requirements.
Test requirements and inspection requirements.
The order of dismantling the parts drawing from the mold assembly drawing shall be: first inside and outside, firstly after complex, simple, first forming parts, and later structural parts.
Requirements are as follows:
Graphic requirements
Must be scaled and allowed to zoom in or out. Reasonable view selection, proper projection, proper layout. To make the patent number easy to understand and easy to assemble, the graphic should be consistent with the final assembly drawing. The graphic should be clear.
Labeling requirements are uniform, centralized, orderly, complete
The dimensioning order is: First mark the major part dimension and draft angle, then mark the fit dimension, then mark all dimensions. On the non-major part diagram, first label the fit dimensions, and then mark all dimensions.
Surface roughness
The most applied roughness is marked in the upper right corner of the drawing, as marked 'Other 3.2.' The other roughness symbols are marked on the surface of the part.
Other content
For example, the part name, mold number, material number, heat treatment and hardness requirements, surface treatment, pattern ratio, free-size machining accuracy, technical description, etc. must be filled in correctly.
Second, proofreading, plan approval
The relationship between mold and its parts and plastic parts drawings
The material, hardness, dimensional accuracy, and structure of the mold and mold parts meet the requirements of the drawings.
Plastic parts
Whether the plastic material flow, shrinkage, welding marks, cracks, draft angle, etc. affect the performance of plastic parts, dimensional accuracy, surface quality, etc. Whether the pattern design is insufficient or not, the processing is simple, the molding material The correct choice of shrinkage.
Forming equipment
Injection volume, injection pressure, insufficient clamping force, mold installation, South core of plastic parts, whether there is a problem with mold release, and whether the injection nozzle and the nozzle cover are in correct contact.
Mold structure
If the position of the parting surface and precision of finishing meet the requirements, will flash occur, and whether the plastic parts can be left on the side of the mold with ejector after mold opening can be guaranteed.
Whether the demoulding method is correct, the promotion rod, the size, position and quantity of the push tube are appropriate, and the push plate will not be jammed by the core, and will not cause scratches on the formed parts.
Mold temperature adjustment. Heater power, quantity; cooling medium flow line position, size, quantity is appropriate.
How to deal with undercuts made of plastic parts, whether the mechanism for removing the undercuts is appropriate, such as whether the sliders and push rods in the slanted guide core-pulling mechanism interfere with each other.
Casting, exhaust system location, size is appropriate.
Design drawings
Whether the position of each mold part on the assembly drawing is appropriate or not is indicated clearly and whether there is any omission;
Parts number, name, number of parts on the part drawing, part built or purchased, standard part or non-standard part, accuracy of parts handling, correction processing and margin at the high-precision dimensions of the molded plastic parts, mold parts The material, heat treatment, surface treatment, whether the surface finish is marked, clearly described.
The main parts of the parts, the working dimensions of the molded parts and the matching dimensions. The size figures should be correct and not to be converted by the producer.
Check the position of the view of all parts and general assembly drawings, whether the projection is correct, and whether the painting method conforms to the national standard of drawing and whether there is any missing size.
Check processing performance
The geometry of all parts, view drawing, dimensions, etc. are good for processing
The main working size of the recalculation aid
Professional proofreading is carried out according to the designer's self proofreading project in principle; however, emphasis is placed on structural principles, process performance and operational safety. When drawing, first digest the graphics, draw the national standard requirements, fill in all dimensions and technical requirements. signature.
The base drawing is submitted to the designer for proofreading and signing. The customary practice is to review by the relevant technical personnel of the tool manufacturing unit, check the signature, check the manufacturing process, and then send it to the sun.
Writing a manufacturing process card
The manufacturing process card is prepared by the tool manufacturer's technical staff and is ready for processing.
In the manufacturing process of mold parts, inspections must be intensified. The focus of inspection is on the dimensional accuracy. After the mold assembly is completed, the inspector conducts the inspection according to the mold inspection table. The main point is to check whether the performance of the mold parts is good or not. To ensure the quality of mold manufacturing.
Third, try mold and repair
Although the mold design was performed under the expected process conditions when the molding material and the molding equipment were selected, people's understanding was often imperfect. Therefore, after the mold processing was completed, the mold test was performed and the molded parts were observed. How does the quality. Always find out afterwards, to eliminate the wrong model.
There are many kinds of plastic products that have bad appearances, and the reasons are also very complicated. There are reasons for molds, and there are also reasons for process conditions.
Before repairing the mold, it is necessary to conduct detailed analysis and study based on the actual situation of the bad appearance of the plastic parts, and to find out the cause of the defects caused by the plastic parts and then propose a remedy. Because the molding conditions are easy to change, the general practice is to change the molding first. Conditions, when changing the molding conditions can not solve the problem, only consider repairing the mold.
Repairing molds should be done with care. There is no certainty that it should not be taken lightly. The reason for this is that once the mold conditions have been changed, it will not be possible to make major changes and restitution.
The performance of the parts is good, only in this way can the manufacturing quality of the slang mold.
Fourth, organize data for archiving
After the mold has been tested, if it is not to be used, it should be completely wiped off the mold release scum, dust, oil, etc., and coated with butter or other rust-proof oil or rust inhibitor, kept in storage.
The design mold is started until the mold is successfully processed and passed inspection. The technical data produced during this period include, for example, the mission statement, the parts drawing, the technical specification, the assembly assembly drawing, the mold assembly drawing, the base drawing, the mold design specification, and the inspection record. Tables, trial mold repair records, etc., are systematically sorted, bound, and numbered for filing as required. This may seem like a nuisance, but it is useful to repair molds and design new molds later.