Computer Aided Drafting, Design and Manufacturing Volume 26, Number 3, September 2016, Page 44

Transcription

1 Computer Aided Drafting, Design and Manufacturing Volume 26, Number 3, September 2016, Page 44 CADDM Sheet material lifting mechanism of manipulator Hong Chao 1, Zou Congcong 1, Huang Bingshun 2, Zhang Li 3, Jin Aimin 4 1. School of Automobile and Traffic Engineering, Hefei University of Technology, Hefei , China 2. School of Electrical Engineering and Automation, Hefei University of Technology, Hefei , China 3. School of Mechanical Engineering, HeFei University of Technology, Hefei , China 4. Flying electric Co., Ltd., Anhui, Hefei , China Abstract: At present, machine fixed up and down repeatedly work is done by human. Although it is low cost and easy to change plate, re are many shortcomings of work injury and low work efficiency. Foreign automatic loading and unloading device has been developed, but principle is more complex, cost is higher, energy consumption is larger, so automatic loading and unloading robot came into being. Aiming at transportation of mechanical raw material, an automatic device is designed to transport scheduled raw materials to specified position according to processing requirements. The device has characteristics of simple operation, rapid response and large range of activities, and has obvious economic and environmental benefits. There is certain popularization value. Key words: manipulator; lifting mechanism; hydraulic drive; motor silicon steel sheet 1 Introduction With rapid development of China's economy and technology, use of motor is more and more common. The requirements of manufacturing precision and safety are increasingly higher. Stamping processing technology develops rapidly in our country, increasing share in mechanical processing. Stamping industry has entered into time of structural adjustment. A series of problems of low efficiency, poor accuracy, slow and so on has been gradually replaced by automatic loading and unloading agencies. The times which rely on low labor costs have ended. Upgrading from traditional labor-intensive industries to technology-intensive industry modernization, and n realizing automatic efficient production has become inevitable trend of stamping industry development [1]. Industry manipulator is developed in recent decades as a kind of high-tech automated production equipment. Industry manipulator is an important branch of industrial robots. Its characteristic is that it can be done through programming to complete various expected tasks, and both structure and performance of industry manipulator inherits advantages of men and machines, particularly, it reflects people s intelligence and adaptability. Industry manipulator has broad development prospect in all areas of national economy, as its accuracy operation and ability to complete operations in various environments. The industry manipulator is a new type of device developed in process of mechanization and automation. In modern production process, industry manipulator is widely used in automatic production line. The robot development and production has become a high technology developed rapidly in field of an emerging technology. It has promoted development of industry manipulator, making it in step with mechanization and automation of organic combination better. Although manipulator is not as flexible as manpower at hand, it has characteristic of being able to repeat work and labor, not tired, not afraid of danger, grabbing a heavier object, so robot has been attention of many departments and has been applied more and more widely. 2 Main ideas The Fig.1 is manipulator work layout. Manipulator specific implementation process: Project item: Supported by The National College Students Entrepreneurship Practice Project ( ); Science and Technology Research Project of Anhui Province (15czz02030). Corresponding author: Zhang Li,Female, Master, Professor, 77zhangli@hfut.edu.cn

2 Hong Chao et al., Sheet material lifting mechanism of manipulator 45 mechanical lift raw work piece to height consistent with punch die, n manipulator send unprocessed work piecee into press mold. After stamping, robot take out finished work and place it specified location to completee whole loading and stamping processs [2]. Fig. 1 Manipulator work layout. Common on market generally in manipulator drive mode is divided into motor drive, hydraulic drive and pneumatic drive. Compared with former two drive modes, pneumatic drive is more superior in quickness, fast response, simple structure and without pollution, so design used pneumatic drive. And manipulator is mainly composed of feeding device, horizontal transport device, heap of raw materials, material of pile and console. In equipment operation, feeding device of vertical drive cylinder pushes vacuum bar to move to heap at top of raw materials, drawing a piece of raw silicon steel sheet. The vertically pushing cylinder returns to original place, n vacuum stop adsorption. Horizontal transport device of electromagnet electricity silicon steel sheet materials will be adsorbed on level of transfers of F form board, moving into mold, and picking out completed processing stampings. In process of return through block, pieces will be blocked and droppedd to finished pile [3-4]. This article is only for design of lifting mechanism of manipulator raw material pile up and down. 3 Design scheme 3.1 General design scheme In order to be able to realize automatic loading and unloading operation, it is necessary to design a specific raw material pile for loading and unloading machinery. In this design, two raw materials heap are placed on same rail. When one of raw materials is at work, operator can replenish anor free raw material stack. In order to allow raw material picking mechanismm to pick up raw material at right place every time, a tray capable of vertical lifting is designed in each individual raw material pile. With help of raw material lifting mechanism, it is possible to realize top level of raw material at same level, as shown in Fig. 2. Fig. 2 General design scheme. 3.2 Raw material pile design The size of raw material pile design with reference to heap of raw materials to design,

3 46 Computer Aided Drafting, Design and Manufacturing (CADDM), Vol.26, No.3, Sep design of raw material is outer diameter of 260 mm, inner diameter of 170 mm, thickness of 0.5 mm electronic silicon steel. According to this data it will be set to 260 mm wide. And n in order to allow raw materials to be neatly stacked, in middle of tray design of three raw materials guide rod, so that all raw materials in accordance with guide rod surrounded by a diameter of 160 mm on circumference of circle to move up and down. Through overall layout of robot, design of a single raw material pile can store raw material space of 400 mm, that is, operator can add about 800 pieces of silicon steel raw materials to raw material heap each time. In order to reduce tension or thrust required to move tray, tray is placed on two parallel SBR cylindrical linear guides in this design, and two trays are joined by a connecting block. In order to reduce resistance of moving raw material tray, a linear bearing is mounted on tray so that resistance of raw material tray is small when it moves up and down. 3.3 Design of raw material lifting mechanism In order to keep top layer of raw material at same level of height, to facilitate design of raw materials separation and picking institutions, we need to design a raw material for raw material of lifting mechanism that raw material can be raised from mm between any distances. Through overall layout of robot, reserved height reserved for this body is 520 mm. And mechanical power source for factory uniform gas source, it is preferred to use cylinder as a lifting power. In mechanical design part, as shown in Fig. 3, through two T-shaped cross-linked with symmetrical mandrel, so that force of raw material pile to lifting mechanism is collinear with axis of cylinder, making cylinder to play a normal lifting performance. Fig. 3 Design of raw material lifting mechanism. The jacking mechanism of lifting mechanism is connected to cross screwdriver, which is in contact with stack of raw materials and is positioned by U-shaped groove, as shown in Fig. 4. Fig. 4 4 Working principle Raw material pallet design. The material stacking mechanism is a mechanism for raising and lowering a tray in which a raw material is stacked under pushing of rod less cylinder, and it is possible to keep uppermost layer of raw material at a set height [5]. In order to make top of pile of raw materials in same level of raw materials at same level, design of a raw material lifts mechanism. The lifting mechanism lifts stack of raw materials toger with a tray, powered by a magnetic rod less cylinder. The principle of its operation on piston is as follows: set up a group of high-strength magnetic permanent magnetic ring, magnetic lines through thin-walled, cylinder and set out on outside of anor group of magnetic ring. Because of two sets of magnetic ring on contrary, produce a strong suction. 5 Cylinder choice Manipulator design requires operating frequency of 15 times per minute to complete punching action, so a punching cycle time is t 60 T = = = 4(s) (1) n 15 t: time, take 60 s; n: number of trips in punch press run every minute. 5.1 The average speed of cylinder Through 3D software measuring feeding device is reserved for bottom to raw material tray distance is 400 mm, so Eq.(2) can be calculated by formula feeding at average speed of cylinder is as follows s v = = = (mm / s) (2) t 3 s: distance of cylinder a back and forth, unit is mm; t: time of cylinder a back and forth required to, unit is s.

4 Hong Chao et al., Sheet material lifting mechanism of manipulator Cylinder load calculation Because cylinder is fixed on base, so raw material heap will have to be borne by base, most of weight, weight of cylinder need to load entire raw material pile, refore, load on cylinder can be calculated as follows F=mg/β=( )/0.1=784 (N) (3) m: cylinder load by quality, maximum load measure is 800 kg; g: acceleration of gravity; β: load factor of said cylinder, look-up table The cylinder diameter selection According to cylinder bore formula 4F D = = = 44.7 (mm) [ P] π 0.5 (4) F: cylinder by load, formula of 4 to 3; [p]: pneumatic system of air pressure, take 0.5 MPa. Therefor rod less cylinder diameter picked 50 mm, piston travel picked 400 mm. 5.4 Gas consumption calculation Manipulator of up and down all use rod less cylinder as a driver, so that we can reduce space of manipulator overall occupied volume, so cylinder gas consumption is 2 2 Ds 3, q = = = ( m /s)(5) 4t 4 1 q: cylinder gas consumption, unit is m 3 /s; D: cylinder inner diameter, unit is m; t: complete whole trip need time, pick up 1 s; s: distance of cylinder stroke, unit is m. Through calculation, according to calculating related parameters of cylinder, type selection of SMC company CY1B50H magnetic rod less cylinder type, its effective stroke is 400 mm, diameter of 50 mm, its maximum output force is controlled in N, to be able to meet design requirements. The cylinder is stable and reliable and is more space-saving relative to rod cylinder volume. 6 Conclusions In this paper, raw material lifting mechanism is designed with rod less cylinder as action device, which is transported to specified position by raw material stack and raw material tray. The whole device has simple and compact structure and is easy to be operated. PLC control technology is used to realize periodic transportation of raw materials. The main components of three-dimensional modeling, according to actual requirements for adjustment and optimization. The main features are as follows: (1) Two raw material heap in parallel, in which a raw material heap at work, operator can be anor free raw material heap to supplement raw material operation; (2) To adapt to different sheet materials; (3) The upper and lower movement of raw materials to overcome resistance tray smaller; (4) Under action of lifting mechanism that top of a piece of raw materials has always maintained at same level of height to facilitate separation of raw materials and picking mechanism design. References [1] Wang T M, Tao Y. Industrial robot technology in our country present situation and development strategy of industrialization [J]. Journal of Mechanical Engineering, 2014, 50 (9): [2] Liang Y J, Wang W, Wang G J. A reciprocating feeding equipment [J]. China Metal Forming Equipment & Manufacturing Technology. 2015, 50 (1): [3] Luo L, Wei Z C, Jin A M, et al. The Design of automatic loading-and-unloading material manipulator for telescopic punch [J]. Computer Aided Drafting, Design and Manufacturing, 2016, 26(2): [4] Bi X, Jin A M, Luo L, et al. Design of automatic feeding-and-unloading rotary manipulator of punching Machine [J]. Computer Aided Drafting, Design and Manufacturing, 2015, 25(4): [5] Zhu X R, Shen H P. Optimal design of link lengths for a planar parallel manipulator [J]. Computer Aided Drafting, Design and Manufacturing, 2012, (4): Hong Chao was born in 1996 and is currently an undergraduate in department of Vehicle Engineering at HeFei University of Technology. His research interests include robotics, intelligent manufacturing and vehicle design. Zou Congcong was born in 1996 and is currently an undergraduate in department of Vehicle Engineering at HeFei University of Technology. His research interests include robotics, intelligent manufacturing and vehicle design. Huang Bingshun was born in 1995 and is currently an undergraduate in department of Electrical Engineering at HeFei University of Technology. His research interests include robotics, intelligent manufacturing and electrical automation.

5 48 Computer Aided Drafting, Design and Manufacturing (CADDM), Vol.26, No.3, Sep Zhang Li received her B.Eng. and M. Eng. Degrees in Mechanical from Hefei University of Technology, China, in 1982 and 1997, respectively. She is currently a professor of School of Machinery and Automobile Engineering, Hefei University of Technology. Her research interests include electro mechanical integration technology, computer aided design and manufacturing. Jin Aimin was born in 1970, and is a Research and development manager of Anhui province Jingde Feixiang Electric Appliance Co. Ltd. His present main research interest is mechatronics.