The quality of scraping and grinding on a platform determines its accuracy. The so-called "scraping and grinding" refers to the combination of scraping and grinding processes. That is, flat scraping and grinding display, then flat scraping and grinding display, and so on, alternating cycle, constantly operating. During the entire scraping and grinding process of cast iron platforms, they generally go through three stages: rough scraping, fine scraping, and fine scraping. Below is a detailed introduction of the cast iron platform:
1. Scratching: Scratching has two functions: firstly, it is aesthetically pleasing, and secondly, it has the function of accumulating lubricating oil. Common patterns include diagonal patterns, swallow shaped patterns, and fish scale patterns. In addition, the degree of wear after flat work can be determined by observing the integrity and disappearance of the original pattern.
2. Rough scraping: If the surface of the workpiece is relatively rough, the machining marks are deep, or the surface is severely rusted, uneven, or twisted, and the scraping allowance is above 0.005mm, rough scraping should be carried out first. The characteristic of rough scraping is the use of a long scraper with a long stroke (between 10mm and 15mm), wide blade marks (10mm), and the scraper marks are in the same direction and do not repeat in pieces. After removing the knife marks from mechanical processing, you can grind them and scrape them according to the visible high points. When there are 4-6 points per 25 ㎡ x 25 ㎡ on the surface of the workpiece and there is a margin for fine scraping, fine scraping can begin.
3. Fine scraping: Fine scraping * is the process of scraping off the high points after rough scraping. Its characteristic is the use of short scraping method (with a knife mark width of about 6mm and a length of 5mm~10mm), which disperses the grinding points quickly. When fine scraping, it is necessary to scrape in a certain direction. After scraping once, the mesh should be scraped at a 45 degree or 60 degree angle when scraping twice. When the average research point is 10-14 points per 25 ㎡ x 25 ㎡, the fine scraping can be ended.
4. Fine scraping: Fine scraping is carried out on the basis of fine scraping, using small scrapers or precision scrapers with arcs. The knife mark width is about 4mm, and the average grinding point should be 20-25 points per 25 ㎡ × 25 ㎡. Cast iron platforms are commonly used for scraping inspection tools, precision guides, and tight tool contact surfaces.