Racks are fundamental and indispensable components in the machinery industry, widely used in industrial equipment such as machine tools, power systems, metallurgical machinery, agricultural machinery, and transportation machinery.
Under the trend of intelligent development in equipment manufacturing, a gear rack manufacturing enterprise in China has only automated a few processes in its gear rack production equipment. Most processes require manual assistance, and some are still entirely manual. The various gear rack processing devices are isolated from each other, and inter-process transfers are done manually by hand. Due to the numerous production processes and high transfer frequency, workers experience high labor intensity. At the same time, the operating workshop is noisy, which is detrimental to workers' health. A more serious problem is that under this production status, gear rack production efficiency is low, capacity is difficult to increase, economic benefits are poor, and the enterprise's development is constrained.
Engineers from Beiganglian Intelligent Manufacturing® went deep into the company's production workshop to conduct a detailed investigation and understanding of the rack production process and personnel involvement. With their rich experience in the development and modification of automated equipment, they upgraded and seamlessly linked the isolated rack processing equipment without changing the original process sequence, forming a complete production line.
Pre-modification process
The gear manufacturing process, from rough machining blank to finished product, involves vertical machining, rough grinding of the outer diameter, rough hobbing, heat treatment, straightening, fine grinding of the outer diameter, fine hobbing, flaw detection, demagnetization, cleaning, bearing pressing, and riveting of retaining rings. In vertical machining, rough grinding, and straightening, the workpiece is placed horizontally on the fixture, while in rough hobbing and heat treatment, the workpiece is placed vertically. The processes before and after straightening are performed by two different types of operators, respectively. The flaw detection process requires entirely manual inspection for cracks.
Figure 1 Workshop Production Diagram
Modified automated production line
The automated production line consists of a stepper feeder, a switching buffer fixture, a mobile robotic arm, a robotic arm running track, a vision inspection system, a power supply system, a safety protection system, and a control system. It realizes functions such as automatic raw material transfer, loading, processing station switching, unloading, and finished product transfer and warehousing.
Figure 2 Overall diagram of the rack and pinion production line
Introduction to the main structure and operation process
Stepper feeder operating status
Stepper feeder buffer loading – Stepper feeder start – (Stepper conveyor mechanism – Run – Material inspection – Unloading) cycle – Stop – Shutdown
Switch cache tool running status
Switch to buffer fixture start-up — (loading — material inspection) loading complete — (unloading — material inspection) unloading complete — positioning device open — rotation switch — positioning device close) cycle operation — shutdown
Control System Introduction
The control system adopts a DCS control system, which consists of control parts such as transfer control, workstation switching control, buffer material storage and retrieval detection control, visual inspection control, and sorting control. Considering the operational reliability of the equipment and the need for upgrades, the PLC part of the control system has a 15% margin in input and output points.
