The quality assurance of stamping production provides customers with high-quality products

1. Mold manufacturing

In order to make the molds manufactured by professional mold manufacturers meet the requirements of vehicle quality and suitable for the production of stamping enterprises, the following work shall be carried out:

(1) Technical exchange: The technical exchange covers the annual production program, equipment capacity, production capacity, production operation mode, selection of mold materials, selection of mold standard parts, mold identification, mold quality requirements, verification standards and other process requirements.

(2) Countersigning of mould drawings: the countersigning of mould drawings is carried out from machine tool matching, safety, production operation, structure, maintenance, etc.

(3) Mold supervision: analyze and summarize the dynamic management of the mold, handle the reasonable changes of mold quality and structure, and ensure that the mold is completed as scheduled according to the quality requirements.

(4) Mold verification: It is carried out around the aspects of product quality, machine tool matching, safety, production operation, structure, maintenance, etc. At the production site, the mold must be verified for stability margin, otherwise the product quality is difficult to control.

2. Daily maintenance of moulds

The daily maintenance of molds is one of the important means to ensure the stability of product quality. In order to ensure the quality of mold maintenance, the following aspects should be focused on:

(1) Skills training for mold maintenance personnel: strengthen the skills training for maintenance personnel, including operation skills, maintenance procedures, mold structure, mold failure
analysis and handling, and establish a highly skilled maintenance team.

(2) Mold management: dynamic management of mold maintenance, summary of mold files, and provision of maintenance plans.

(3) Spot check for mold cleaning: Carry out spot check for mold cleaning according to the plan to achieve high mold cleanliness.

(4) Mold spare parts: do a good job of mold spare parts according to the mold files, focusing on the management of the spare parts warehouse. To achieve reasonable inventory for mold maintenance, attention should also be paid to the quality of spare parts, because the quality of spare parts also endangers the product quality.

Stamping sheet is the key to ensure the internal quality of products, and is the quality control object in the stamping production process. For a certain type of stamping plate, its mechanical properties fluctuate within a certain range, so the corresponding requirements for mold and equipment will also change. If the process conditions are not adjusted in time, the product quality will not be guaranteed. The following aspects shall be paid attention to in the quality assurance of stamping plates:

1. Plate identification: check the material, specification, heat number, coil number and manufacturer.

2. Statistics of mechanical property data of plates: the mechanical properties of each batch of plates put into production shall be recorded, including material, specification, heat number, coil number, mechanical properties (tensile strength/yield strength/n value/r value), manufacturers and service conditions.

3. Production tracking: record the use of plates in the production process, such as the status, type and scrap rate of defective products, and record the contents in the mechanical property data statistics of plates to guide the determination of the safety domain of steel plates in future production, provide production forecasts, rational use of plates and production procurement.

The process document is the basic document to ensure the stamping quality, among which the Stamping Operation Standard, Stamping Operation Essentials and Stamping Part Quality Inspection Essentials guide the production. In addition, the stamping workshop must formulate a Stamping Part Inspection Specification to constrain employees to inspect stamping parts.

1. Stamping operation standard book: the process document to guide the operator to quickly and accurately adjust the qualified products, mainly including the installation position, closing height, stamping tonnage, balance cylinder pressure, position diagram of jacking rod, jacking pressure, jacking height, jacking angle and other parameters.

2. Stamping operation essentials: guiding process documents to guide operators to safely operate the machine tool and use the mold, including mold clamping, production operation inspection, packing inspection, identification, etc.

3. Product quality self inspection essentials: a guarantee document for maintaining the stability of stamping parts‘ quality, which will list stamping parts‘ quality problems, qualification standards, division of responsibilities, inspection methods, tools used, parts‘ diagrams (indicating parts and types of problems that are prone to occur), punching quantity of each process, plate material specifications and dimensions, safety tips, etc.

As the preliminary work of stamping process, we must carefully and carefully prepare for production. The main work includes three aspects:

1. For the mold, careful inspection shall be carried out, including the integrity of the appearance, upper/lower surfaces and mold accessories;

2. Check whether there are special marks, scratches, bumps, rust, and falling double materials on the sheet;

3. Check whether the specifications and models of the station instruments are prepared according to the process documents.

"Product quality is manufactured, not detected", which can be fully reflected in the stamping production process, because the correctness of stamping production operation is directly reflected in the product quality of stamping parts.

The following aspects shall be controlled during stamping production:

1. Process adjustment: adjust all parameters in strict accordance with the Stamping Operation Standard to ensure accuracy.

2. Mold inspection: check the mold appearance, mold cavity, the sensitivity and reliability of the action of functional elements, and the lubrication of relative moving parts.

3. Equipment spot inspection: including clutch air pressure, lubricating oil pressure, protective oil pressure, inching inspection, oil and gas leakage, etc.

4. Self inspection of parts

There are some uncontrollable factors in the stamping production process. Small changes in sheet metal and die may lead to fluctuations in the quality of stamping parts. In order to reduce fluctuations, problems need to be found and solved in a timely manner. Especially in the early stage of mass production of dies, the independent inspection of parts is particularly important, because the occurrence of new problems in the quality of parts is relatively concentrated in this period. Years of practical experience has proved that if the problems encountered are completely solved in the early stage of mass production, there will be almost no recurrence of the same problem in the future.

Self inspection shall focus on inspection and interval full inspection according to Quality Inspection Essentials of Stamping Parts. When formulating inspection specifications, the specifications shall specify inspection items, inspection contents, inspection methods, tools, judgment principles, causes and solutions.

5. Stacking of workpieces: single products shall be stacked in the work station apparatus specified by the process, and the workpieces shall be marked. Parts identification includes vehicle type, parts name, quantity, production team, production date, etc.

Warehousing logistics

The stamping production must have a certain safety stock. In terms of the quality of the products stored in the warehouse, attention should be paid to the implementation of "cash in and cash out" during storage to prevent corrosion, and attention should also be paid to the control of transportation speed to prevent bumping.