Technical specifications for wooden pattern and core box for foundry
1 Subject content and applicable scope
This standard specifies the grades, technical requirements, acceptance rules, markings and storage of wooden patterns and core boxes for sand casting process.
This standard is applicable to wooden patterns and core boxes for sand casting process, and also to mixed patterns and core boxes of wood and metal.
2 Normative references
GB 153.1 Coniferous sawn timber — Species tolerance
GB 153.2 Coniferous sawn timber — Grading
GB 4817.1 Broad leaves sawn timber — Species, Sizes, Tolerance
GB 4817.2 Broad leaves sawn timber — Grading
GB 5611 Foundry terminology
GB/T 11350 Machining allowances on castings
GB 12472 Surface roughness parameters and their values for wooden pieces
GB/T 14495 Roughness comparison specimens for wooden pieces
JB/T 5105 Casting form — Pattern draft
JB/T 5106 Calculation method of castings material consumption process quota
3 Terms
3.1
measurement dimension
sum of the basic dimensions of parts, machining allowance on castings, shrinkage margin of castings, other process allowance, and casting form pattern draft on the casting process drawing, as well as that dimension of the core print
3.2
flatness tolerance
maximum distance allowed between the working plane and the ideal plane of the pattern and core box
3.3
coincident dimension tolerance
tolerance of overlapping dimension of parting line or parting of core box
3.4
dimension tolerance of tooling
only the dimension tolerance of pattern and core box, which includes the sand box and pattern mounting plate for manual molding and universal molding machine
3.5
unspecified dimension tolerance
dimension tolerance other than center distance tolerance, fit dimension tolerance, overlapping dimension tolerance, wall thickness tolerance, process equipment dimension tolerance
3.6
universal molding machine
molding machine which, if used for molding, does not require the sand box to be equipped with limit and slide and requires the side wall of the sand box not to be provided with box structure except the lifting shaft
4 Grade of pattern and core box
In accordance with the number of uses of pattern and core box and different requirements for the castings’ accuracy, it can be classified into the following three grades.
4.1 Grade I pattern and core box
It is applicable to any of the following situations:
Foreword i
1 Subject content and applicable scope
2 Normative references
3 Terms
4 Grade of pattern and core box
5 Technical requirement
6 Painting
7 Acceptance rules
8 Marking and storage
Annex A Splicing, overlap joint, rim folding and thick-opening fillet structure (Supplement)
