Year1
- 材质：
- HT250
- 型号：
- 齐全
- 硬度：
- HB200
Technical requirements for large cast iron platforms
The working surface of large cast iron platforms shall not have sand holes, pores, cracks, slag inclusions, shrinkage porosity, scratches, bruises, embroidery spots and other defects that seriously affect the appearance and performance. .
The casting surface of large cast iron platforms should be clear of molding sand, smooth and firmly painted.
On the flat working surface of a large cast iron platform with an accuracy level of Class ~, sand holes with a diameter smaller than mm are allowed to be plugged with the same material, and their hardness should be smaller than the hardness of the surrounding materials. There should be no more than one sand hole blocked on the working surface, and the distance between the sand holes should not be less than mm.
Large cast iron platforms should be made of high-quality, fine-grained gray cast iron and other materials, and their working surface hardness should be ~HB.
The working surface of large cast iron platforms usually adopts scraping process. For the flat plate working surface processed by scraping, the maximum allowable value of surface roughness R is mu
. The large cast iron platform should be demagnetized and stabilized.
On the two opposite sides of the large cast iron platform, there should be threaded holes (or cylindrical holes) for installing handles or lifting eye devices, and the device locations should be designed to minimize deformation caused by handling.
If a threaded hole (or groove) is provided on the working surface of a large cast iron platform, its location should not be higher than the working surface.
How to evaluate scraping contact spots during calibration of large cast iron platforms
Large cast iron platforms are important tools widely used in precision testing, inspection, and marking in the machinery industry. In order to extend the service life of large cast iron flat plates and ensure usage accuracy, the quality of scraped contact spots is an important technical indicator of large cast iron flat plates.
The current evaluation of scraping contact spots
Firstly, check the microscopic quality of the working surface of large cast iron flat plates, that is, the flatness of tiny peaks and valleys. Only high surface microscopic quality and good wear resistance can ensure the flatness of the flat plate. service life.
The second is to prevent small-scale local distortion of the working surface of the large cast iron platform to ensure the accuracy of the large cast iron platform.
The requirements for scraping and grinding contact spots in the calibration regulations for large cast iron platforms are shown in the table below
The requirements for scraping and grinding contact spots in the calibration regulations for large cast iron platforms
Large cast iron platforms are grade-level, grade-grade
Contact spots for scraping large cast iron flat plates (mm)
Number of spots
The difference between the maximum and minimum number of spots is not greater than 1 point
Standard specifications for large cast iron platforms
Large cast iron platforms according to standards Manufacturing, the products are made into stiffened plate type and box type. The working surface has a rectangular shape. The material is gray iron H, HB. The working surface adopts scraping and grinding technology. The working surface can process shaped, shaped, U-shaped grooves, round holes, long holes, etc. . The large cast iron platform is a flat reference instrument used for workpiece inspection or marking. The flat plate installation should be adjusted to a level with the load evenly distributed on each fulcrum, and vibration should be avoided when used at ambient temperatures
Standard specifications of large cast iron platforms and corresponding grade standards
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