Manufacturing method and device for U-shaped spring for elevator safety clamp

Abstract

The invention discloses a manufacturing method and device for a U-shaped spring for an elevator safety clamp. Spring steel strip heating is conducted through a heating die of an induction furnace, andU-shaped spring forming is conducted through oil pressure forming via a U-shaped spring forming oil pressure device. The following technology steps are included, firstly, discharging is conducted, and a discharging machine is used for machining a steel bar into a spring steel strip with the assigned length; secondly, spring steel strip heating is conducted, and the spring steel strip is placed onthe heating die of the induction furnace to be heated; thirdly, U-shaped spring forming is conducted, and the U-shaped spring forming oil pressure device is adopted for oil pressure forming; fourthly, vibration chamfering is conducted, the pressed formed U-shaped spring is placed in a grinding vibrator to vibrate together with abrasive materials; fifthly, milling machining is conducted; sixthly,the U-shaped spring is subjected to heat treatment, quenching treatment and tempering treatment; and seventhly, surface treatment is conducted. According to the U-shaped spring manufactured through the manufacturing method and device, few spring decarburized layers exist, the oxidized rate is low, mechanical character consistency is high, the service life is long, the spring is not prone to beingclamped to a forming die during material stripping, and energy saving and environment friendliness are achieved in the manufacturing process.

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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