What is the grinding process for electronic scale molds
The grinding process of electronic scale molds is a key precision machining step to ensure their dimensional accuracy and surface smoothness to adapt to the production of electronic scale shells, buttons, and other parts. It is necessary to select the corresponding grinding method based on the structural characteristics of different parts of the mold (such as template planes, shaft parts, cavity c
The grinding process of electronic scale molds is a key precision machining step to ensure their dimensional accuracy and surface smoothness to adapt to the production of electronic scale shells, buttons, and other parts. It is necessary to select the corresponding grinding method based on the structural characteristics of different parts of the mold (such as template planes, shaft parts, cavity cutting edges, etc.). The overall process and details are as follows:
1. Preparation before processing
Drawing analysis and scheme formulation: Firstly, clarify the accuracy requirements of each part of the electronic scale mold, such as the flatness of the parting surface of the shell mold, the dimensional tolerance of the key convex mold, etc., determine the parts that need to be ground (such as the template plane, the outer circle of the guide column, the inner wall of the mold cavity, etc.), and then match the corresponding grinding process.
Grinding tool and equipment selection: If processing templates made of common materials such as mold steel, GD single crystal corundum grinding wheel can be selected; If it involves high hardness parts after quenching, priority should be given to using diamond grinding wheels or CBN grinding wheels with organic binders. In terms of equipment, surface grinders are used for processing flat surfaces such as templates and parting surfaces; Internal grinding machine for processing inner holes such as guide sleeves; Grinding guide columns and other axial parts with an external cylindrical grinder; A CNC forming grinder can be used for complex cavity cutting edges.
Workpiece pretreatment and clamping: Before grinding, it is necessary to confirm that the mold parts have completed rough machining and heat treatment, and have undergone past stress treatment to avoid deformation caused by stress release during grinding. When clamping, flat parts are often adsorbed on electromagnetic suction cups, and thin templates need to be padded with rubber between the suction cup and the workpiece to reduce deformation; Shaft components are fixed with chucks; The fine convex mold can be placed on a V-shaped frame and can also be filled with clay to prevent vibration around it.
2. Targeted grinding processing
Flat grinding: This is the core grinding process for electronic scale mold templates, parting surfaces, and other parts. The circular grinding method is used to grind the circumferential surface of the grinding wheel. First, rough grinding is used to remove about 2/3 of the excess, and then fine grinding is carried out after dressing the grinding wheel. Smooth grinding is performed 1-2 times, and then another parallel surface is machined after flipping. After machining, the flatness parallelism is less than 0.01:100, and the surface roughness can reach Ra=0.2-0.4 μ m. If processing adjacent vertical reference surfaces, the small template is clamped with precision flat pliers, and the large template is aligned with precision angle iron, dial gauge, and angle ruler before grinding.
Internal and external cylindrical grinding: For rotating parts such as guide columns and guide sleeves of electronic scale molds, the external cylindrical grinder grinds the outer circle of the guide column, and the internal cylindrical grinder processes the inner hole of the guide sleeve. During grinding, the coolant should be fully poured into the contact area, and the clamping force of thin-walled sleeve parts should be controlled to prevent deformation. The dimensional accuracy after machining can reach IT6-IT7 level, and the dimensional error during high-precision grinding can be controlled within 0.005mm.
Forming grinding: Complex shaped parts such as key molds and cavities of electronic scale molds require forming grinding. Either grind the grinding wheel into a shape that matches the surface of the workpiece, or use a specialized fixture to adjust the position of the workpiece for segmented grinding, so that the connection between the arc and the straight line smoothly transitions, meeting the requirements of the irregular structure of the part and reducing the workload of subsequent fitters.
3. Post processing inspection and finishing
Accuracy and surface quality testing: Use a dial gauge and micrometer to measure dimensional tolerances, and use a roughness meter to measure surface roughness; Complex parts can be measured for form and position tolerances using a coordinate measuring instrument. If the error range is exceeded, the grinding wheel needs to be re adjusted or subjected to secondary grinding.
Follow up processing: Remove burrs and blunt edges and sharp corners of the parts; Eliminate the hardened layer left by electrical machining; Perform demagnetization treatment on the parts to avoid adsorbing iron filings and affecting subsequent assembly; Clean the surface with cleaning agent to prepare for mold assembly.