When selecting a welding robot from manufacturers, or purchasing an intelligent welding robot, it is crucial to fully and accurately understand its performance specifications. Proficiency in the main technical specifications of the intelligent welding robot is prerequisite to operating it correctly when welding workpieces.
Typically, the product manuals from welding robot manufacturers provide rather basic technical specifications, and some technical performance indicators need to be deeply understood based on the user’s actual situation through business communications and onsite inspections.
The main technical specifications of welding robot manufacturers can be divided into two major categories: general technical indicators for welding robots and specific technical indicators for welding robots.
I. General Technical Indicators for Welding Robots
1. Degrees of Freedom:
This is an important indicator reflecting the flexibility of the welding robot. Generally speaking, three degrees of freedom can reach any point in the working space of the welding robot.
However, welding not only needs to achieve a certain position in space, but also needs to ensure the spatial posture of the welding gun or welding tongs.
Therefore, arc welding robots and welding cutting robots need at least five degrees of freedom, and spot welding robots need six.
2. Load Capacity:
This refers to the rated load that the end of the welding robot can bear, including the welding gun and its cables, cutting tools and gas pipes, welding tongs and cables, cooling water pipes, etc.
Therefore, the load capacity of arc welding robots and welding cutting robots is 6-10kg. If a spot welding robot uses an integrated transformer and integrated welding tongs, its load capacity should be 60-90kg. If using separate welding tongs, its load capacity should be 40-50kg.
3. Working Space of Welding Robots:
The working space provided by manufacturers is the maximum reachable space of the welding robot without any end effector installed, represented graphically. It is important to note that after installing equipment like a welding gun or welding tongs, the welding gun’s posture needs to be maintained.
The actual welding space will be smaller than what the manufacturer provides, and it is necessary to carefully calculate with scale drawing or modeling methods to determine whether it meets the actual needs of the manufacturer.
4. Maximum speed of welding robot operation:
This is an important indicator that affects production efficiency in welding production. The product manual of the welding robot manufacturer provides the maximum speed that the welding robot can reach at the end of its wrist under the condition of linkage of each axis.
Due to the low speed required for welding, the maximum speed only affects the positioning, idle travel, and end return time of the welding gun or welding clamp.
5. Point to point repetition accuracy:
This is one of the most important indicators of welding robot performance. For spot welding robots, starting from the welding process requirements, their accuracy should reach less than 1/2 of the electrode diameter of the welding clamp, that is,+1-2mm; For arc welding robots, it should be less than 1/2 of the welding wire diameter, which is 0.2-0.4mm.
6. Trajectory repetition accuracy:
This indicator is very important for arc welding robots and welding cutting robots, but various robot manufacturers cannot provide this indicator because the measurement process is relatively complex. Usually, various robot manufacturers conduct this measurement internally and should insist on requesting its accuracy data.
For arc welding robots and welding cutting robots, their trajectory repetition accuracy should be less than 1/2 of the diameter of the welding wire or the diameter of the cutting hole of the cutting tool, and generally need to reach below+0.3~0.5mm.
7. User Memory Capacity:
This refers to the capacity of the main computer memory within the welding robot controller. It indicates the length of the teach program the welding robot can store, which relates to the complexity of the workpiece that can be processed, or in other words, the maximum number of teaching points.
It’s usually expressed by the coefficient that can store robot instructions and the total number of bytes stored. It can also be represented by the maximum number of teaching points.
8. Interpolation Function:
For arc welding robots, welding cutting robots, and spot welding robots, they should all have linear interpolation and circular interpolation functions.
9. Language Conversion Function:
Each robot manufacturer has its own proprietary language, but its screen display can be in multiple languages. For example, a Yaskawa welding robot can display in Chinese, Japanese, English, German, French, and other languages.
10. Self-diagnosis Function:
Welding robots should have various functions such as automatic checking of major components, main function modules, fault alarms, fault location display, etc. This is very important for ensuring rapid repair of welding robots and providing assurance.
Therefore, the self-diagnosis function is an important feature of welding robots and one of the main indicators of the product completeness of welding robot manufacturers.
The four major families of robots all have 30-50 self-diagnosis function items, displaying their diagnostic results and alarms to users via designated codes and indicator lights.
11. Self-Protection and Safety Features:
Welding robots possess self-protection and safety features. These primarily include protection mechanisms like drive system overheating self-power-off, action limit overreach self-power-off, and over-rotation self-power-off, all of which prevent the welding robot from causing injury or damaging auxiliary equipment.
Tactile or proximity sensors are installed at the working parts of the welding robot, enabling it to automatically stop working when necessary.
II. Technical Specifications for Welding Robots
1. Applicable robotic welding or cutting methods:
This is particularly critical for arc welding robots, essentially reflecting the interference resistance capabilities of the robot’s control and drive systems.
Typically, arc welding robots only employ methods of Gas Metal Arc Welding (GMAW), as these methods don’t require high-frequency arc initiation, and the robot’s control and drive systems lack special interference countermeasures.
Arc welding robots capable of using Tungsten Inert Gas (TIG) welding are recent innovations, equipped with a distinct set of interference countermeasures. For users, this is an important consideration when selecting a robot.
2. Oscillation Function:
This is highly important for arc welding robots as it directly impacts their welding process performance. The extent of oscillation capabilities varies greatly among these robots.
Some only offer a fixed set of oscillation modes, while others allow for arbitrary setting of oscillation modes and parameters within the X-Y plane. The optimal choice, however, would be robots that allow for arbitrary setting of oscillation modes and parameters within the 3D space (X-Y-Z).
3. Welding Process Point Teaching Function:
This is a particularly useful feature during the welding instruction process. It first involves teaching the position of a certain point on the weld seam, followed by adjusting the posture of the welding torch or clamp. During posture adjustment, the original teaching position remains unchanged.
Essentially, the welding robot can automatically compensate for location changes caused by posture adjustments, ensuring the stability of the coordinate point, and thereby making it easier for the operator.
4. Welding Process Fault Self-Diagnosis and Self-Handling Function:
This refers to common welding process faults in welding robots, such as arc welding wire sticking, wire breaking, and spot welding electrode sticking.
If these faults occur and are not addressed promptly, it could result in major accidents, such as damage to the welding robot or scrapping of workpieces.
Therefore, it is essential that welding robots can detect these types of faults and automatically halt and alert in real-time.
5. Arc Initiation and Termination Function:
To ensure the quality of robot welding, parameter changes are needed. During the welding production process with a welding robot, settings and modifications should be made during the teaching phase. This is also one of the essential functions of an arc welding robot.