Manufacturing method of U-shaped spring for elevator security pincers

Abstract

The invention discloses a manufacturing method of a U-shaped spring for elevator security pincers. The manufacturing method is that a spring steel bar is heated through a heating die applied to an induction furnace, and the U-shaped spring is formed under oil pressure effect through a forming oil pressure device for the U-shaped spring. The manufacturing method comprises the steps of (1) blanking, namely, processing bar steel into a spring steel bar with the specified length through a blanking machine; (2) heating the spring steel bar, namely heating the spring steel bar through the heating die applied to the induction furnace; (3) forming the U-shaped spring, namely, forming under the oil pressure through the forming oil pressure device for the U-shaped spring; (4) vibrating and chamfering, namely, vibrating the pressed and formed U-shaped spring through a grinding vibration machine together with grinding materials; (5) milling; (6) thermally processing the U-shaped spring, quenching and tempering; (7) performing surface finish. The U-shaped spring manufactured by the method has the advantages that decarburized layers of the spring are minimized, the oxidizing rate is low, the consistency of the mechanical properties is high, the service life is long, the spring is difficulty clamped on the forming die during discharging, and the manufacturing is energy saving and environmentally friendly.

Description

technical field [0001] The invention relates to a method for manufacturing U-shaped springs for safety gears. U-shaped springs for safety gears are used in occasions where the load is large and the deformation is small, and the spring stiffness is relatively large and symmetrical pressure needs to be applied. It belongs to the spring manufacturing method technology field, in particular to a method for manufacturing a U-shaped spring for elevator safety gear. Background technique [0002] U-shaped springs for safety gear are referred to as U-shaped springs, which are processed and formed by spring steel bar steel. The current processing process is: spring steel sheet->cutting->forming->milling->heat treatment->vibration rounding- >Surface treatment; the traditional molding process adopts the traditional heating and simple mold forming method, that is, a batch of sawn blanks (about 200 pieces) are heated to about 750°C in a box furnace and kept for 0.5 hours,...

AI Technical Summary

Problems solved by technology

The disadvantage is that the heating time is long (about 2 hours), and it is easy to cause a deep surface oxide layer and decarburization layer; the time span from the first piece to the last piece of the same batch of products is about 1 hour, and the front and rear products will be damaged in a high temperature environment. The depth of the oxide layer and the decarburization layer are seriously inconsistent, which will seriously affect the consistency and service life of the final product's mechanical properties; especially after being used in the elevator safety gear, it will seriously affect the safety of the elevator, and the product is easy to get stuck in the mold after molding. It is not easy to take out and the molding efficiency is low; due to the manual control of the lifting operation of the hydraulic press, the molding holding time is inconsistent, and the geometric dimensions of the product, especially the thickness dimensions that are highly correlated with the force value characteristics, are poor in consistency; the hardness of the U-shaped spring after heat treatment is HRC42-48, the processing time of the vibration rounding process needs to be about 24 hours, the processing time is long, the energy consumption is large, and the equipment utilization rate is low

[0003] Because the U-shaped spring processed by the traditional process has low processing efficiency, high energy consumption, and poor consistency of mechanical properties; therefore, it is necessary to improve the production efficiency of the U-shaped spring and improve the production method of the U-shaped spring to improve the service life of the U-shaped spring and Reduce the oxide layer and decarburization layer on the surface of the U-shaped spring to improve the safety of the elevator, and improve the consistency of the thickness and mechanical properties of the produced U-shaped spring

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