Brand CRM High carbon steel profile wire mill stiffness
The stiffness of the wire rolling mill and the influence of the unavoidable gap in the mechanism are also the most important factors that directly affect the accuracy of the rolling stock. Over the past few years, my country has done a lot of work on improving the stiffness of the wire rolling mill and strip rolling machine for the finished stand and the front stand, and has achieved obvious results. Due to the poor stiffness of the front rolling mills, it is impossible to completely rely on the last two rolling mills to eliminate the errors accumulated in the previous ones. At present, the implementation of precision rolling abroad requires high stiffness for all wire rolling mills and cold wire drawn machine,wire drawing machine,wet wire drawing machine, including roughing wire drawing and rolling machine mills. According to the results of experimental simulation in Japan, to implement precision rolling, if the rigidity of each stand reaches 2000KN/mm, the temperature of the furnace is 950℃±20℃, and the heating is uniform, tension-free rolling is carried out. The dimensional accuracy of the large-scale bar after making eight passes can be within ±0.1% of the diameter of the finished product. For this reason, in recent years, in the roughing mills of small precision rolling mills, such as compact precision rolling mills, single-pass rolls with large diameters and short roll bodies have been used to reduce the deflection of the rolls and improve the rigidity. Foreign countries still attach so much importance to improving the rigidity of roughing mills, which shows that it is not enough for us to only renovate the rigidity of two rolling mills. Some manufacturers in my country have the practice of transforming finishing mills K1, K2, K3 or a row of five frames, and the results have proved that it is very effective in improving the precision of finished products.
For the tandem type medium-sized rolling mill, the first two frames can be considered to use rolling bearing open frames, and the last finishing mill can be used with closed two-high rolling bearing rolling mills, which can increase the rigidity of the rolling mill by more than 1-2 times. According to our calculation, the rigidity of the ∅500 two-roll closed rolling bearing rolling mill can reach 1300KN/mm when the length of the roll body is 1150mm. If the roll body is shortened, the rigidity can be further improved. Take the high-rigidity stand of the ∅500 compact strip rolling mill as an example, because of its short roll body (single-pass rolling, the roll body is 320mm), and the wire rolling mill is a short stress line structure, its stiffness reaches 2456KN/mm. In short, improving the rigidity of the rolling mill is the first and not difficult problem that should be solved in the implementation of precision triangle wire rolling.
The clearance of the square wire rolling mill mechanism, especially the axial movement clearance of the finished product and the former stand, is also an important factor affecting the dimensional accuracy of the rolled piece. This clearance includes the clearance of the thrust bearing of the roll in the bearing housing, as well as the clearance of the bearing housing itself relative to the arch or other fixed supports of the rolling mill without arch. According to foreign research results, not only the clearance of the thrust bearing itself should be limited within 0.05mm, but also the axial clearance between the bearing seat and the arch should be reduced from the usual ±0.15mm to ±0.025mm. To achieve this purpose, a hydraulic wedge is developed to fasten the side pressure plate, so that the bearing seat can be firmly fixed on the machine seat during rolling, and it will not be stuck when the pressure is adjusted.
For short stress lines, high stiffness, prestressed wire rolling machine mills and other non-pavilion rolling miachine, the problem of axial clearance should also require stricter control to achieve the expected rolling accuracy.
About our company
Sky Bluer Environmental Technology Co. Ltd is manufacture specialized in precision cold rolling mills and systems for metal shaping, which mainly includes micro precision cold rolling mills, rolling cassettes, Turk heads,universal rolling mills, and precision rollers. We have independently R&D rectangular spring wire, flat wire rolling mill, volute spiral spring continuous rolling line, valve spring rolling mill, and triangular wire rolling mill to replace brand Europe/USA/Japan cold rolling mills.
By the new method of Self-made cold rolling mill combined with drawing rolling die, our concept will be adjusted to this new method it guarantees for the most cost-saving quality improvement of your products. better quality in evenness and finishing, the straightness up to 0.5mm/m, thickness and width tolerance can be accurate down to within 0.005mm.Active introduction of Brand Japan small high-precision roll processing and grinding technology, the roundness tolerance is less than 0.001mm., finishing is 0.02μm.
Service Commitment: What we provide is not only equipment, but also technology and service. We provide users with free-of-charge for shaped wire proofing and hole design.
