The Automated Packing design of industrial robots (Robotic cable management system) is a very key part of robot design. However, it is often ignored or left to the final part of the design process, whether the wiring design is reasonable or not will affect the robot’s range of motion, cable life, overall appearance, installation and maintenance and other issues, is a technical point that should be paid attention to and carefully considered. This paper will be summarized from the industrial robot wiring requirements, common wiring types, pipeline package components and other functions.
1 Industrial robot wiring Automated Packing requirements
The Automated Packing wiring of industrial robots (this article refers to the six-axis industrial robot arm with series joints) is usually divided into two categories: body wiring and end wiring with loaded tools. Among them, the body line refers to the power line of six motors, the encoder line, and the reserved gas pipe and IO line; End tool cables include air source cables, bus power cables, bus signal cables, and IO cables. When the robot is connected to the teaching device and control cabinet, the wiring outside the body will also be involved. Here, only the body and end tool cables mounted on the body of the robot are considered, and other external wiring harnesses are not considered.
Body Automated Packing wiring requirements
The Automated Packing wiring needs of industrial robot body cables are made from three aspects: wire demand, body installation demand, and performance quality demand.
From the demand of the Automated Packing wire, the electrical performance is first required to meet, including the rated current peak current, duration, rated voltage, voltage resistance, shielding, conductor resistance, insulation resistance, and then consider the quality performance, material, UL grade, flame retardant, oil resistance, etc. Then consider the assembly performance, bending radius, winding mode to lay, wire diameter, wire length, joint and so on.
From the installation needs of the body Automated Packing, the body harness fixed point, fixed mode, protection mode, movement avoidance direction, easy installation and easy maintenance;
In terms of performance quality requirements, the body Automated Packing wiring harness is required to meet the cable standards, and the quality is qualified under the specified test conditions; In addition, during debugging, it is required that the harness does not hinder the range of motion of the robot, reduce friction with the body as much as possible, and the stability and wear resistance of the connection point.
In addition to this, there are some potential requirements of Automated Packing , such as the impact of cables on the appearance of industrial robots, cable supply cycle and cost issues.
End tool Automated Packing wiring
At present, the most common scenes of industrial robots are handling, welding, processing, spraying, in addition to welding will back a feed box on the cable, the rest of the cable are power lines, signal lines, gas pipes, IO lines and other conventional cables. For example, the spot welding pipeline package carried by ABB contains 4 water pipes, respectively: red, green, blue, black, inner diameter 1/2 “(about Ø12.5), outer diameter Ø19; The handling/piping package contains 2 water pipes, respectively: blue, black, inner diameter 1/2 “(Ø12.5), outer diameter Ø19.
The wiring of the end tool is usually routed using a Automated Packing alone, rather than mixed with the body, so that it is easy to match the pipeline package for different application scenarios. The pipeline package is a complete set of wiring harness solutions and products designed and made to protect cables and gas pipes, which can significantly reduce the wear and aging of cables and gas pipes, and reduce the bending and torsional forces borne by cables and gas pipes. In the layout of the pipeline package, in addition to the internal cable composition should be clear, but also need to consider the movement space of the robot under the application, to prevent the interference of the pipeline package movement; In addition, in the rotating part, it is necessary to consider the stress of the wiring harness, bending radius, shielding, etc.
Common Automated Packing wiring types of industrial robots
Body Automated Packing wiring pattern
In addition to ensuring that the function is barrier-free and does not restrict the movement of the robot, the cables and gas pipes of the industrial robot body need to meet the life performance of environmental protection, flame retardant, oil resistance, high and low temperature resistance, distortion resistance, high softness, high wear resistance, anti-interference, and installation and maintenance requirements such as beautiful appearance, easy assembly and operation, and easy maintenance. Reasonable cable and gas pipe selection, layout, not only can greatly reduce the problem, but also can greatly shorten the installation, maintenance hours, improve production and maintenance efficiency.
(1) Wiring principles of Automated Packing
Wiring harness layout needs simple structure, convenient disassembly, beautiful layout, good fixed protection and so on. The wiring harness layout should consider the wiring harness principle, make the wiring harness path as short as possible, adopt the modular design in the wiring harness as far as possible, reduce the loop, the main layout principles are the reliability of the wiring harness, the beauty of the wiring harness, the assembly and maintenance, electromagnetic interference protection, etc.
(2) Body wiring design process of Automated Packing
Line layout: line fixed point distribution, line diameter and line length parameters, wire harness diagram
Scheme selection: harness protection, body connection scheme, connector design selection
Wiring harness assembly: Wiring harness connection and assembly requirements for each component.
(3) Automated Packing Wiring type
The wiring harness of the body of the industrial robot can be fixed by a variety of ways, such as clips, cable ties, hoop, trough, bracket, etc., and the sheet metal is fixed together with the body.
When the cable harness of automated packing passes through the sealing cavity, use a perforated rubber part to install the cable. The rubber parts are usually passed through the hole opened by the sealing cavity, which can prevent the wear or collision between the wire harness and the hole wall, and also play the role of waterproof, dustproof and noise isolation. The optional materials of perforated rubber parts are natural rubber, neoprene rubber, silicone rubber and EPDM rubber, etc., but EPDM rubber is more widely used, with lower cost, excellent aging resistance and good elasticity. The physical and mechanical properties of natural rubber are excellent, but the oil resistance and solvent resistance are not good, the temperature resistance is not high, and the use temperature is generally lower than 100℃; Silicone rubber is the best high temperature and cold resistant rubber, but the mechanical strength is low, oil resistance and solvent resistance is poor; The physical properties of neoprene rubber are not inferior to natural rubber, but the cold resistance is poor and the electrical insulation performance is not good.
In addition, when the wire harness of automated packing passes through the sealing cavity, the wire harness can also be passed through the hollow part by the way of a hollow cylinder, and the sealing cavity relies on the perimeter wall of the hollow cylinder to maintain the protection level. This occasion is usually used for hollow wire 1 axis, 4 axis, 6 axis, etc., which needs to be used in conjunction with the mechanical structure, such as changing the hollow reducer, using the offset motor and so on.
It is important to note that the use of cable ties is not a recommended solution, as it is easy to tie it too tight, which can cause internal damage to the cable and sheath, which is difficult to observe from the outside.
The wiring harness of automated packing protection method of the industrial robot body is usually wrapped by elastic parts at fixed points, and the protective jacket covers the wiring harness as a whole. Wrap the cables at fixed points with elastic materials, wrap the outer parts with protective materials, such as corrugated pipes, hoses, or fireproof cloth, and secure the cables to the sheet metal supports connected to the body using metal clips or sheet metal sheets. On the one hand, elastic materials can generate elastic force under the action of sheet metal to tighten the cable, and on the other hand, they can prevent the friction between the wire sleeve rubber and the edge of the sheet metal part from damaging the wire harness of automated packing.
