The hottest tack welding can also realize flexible

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Tack welding can also realize flexible automation (Part 1)

the whole process of welding connection is becoming more and more automated, but tack welding is not included. Because there are a variety of transparent colors to choose, it is convenient for surgery to distinguish. The flexible automation of the welding process improves the productivity and quality, so it can save time and cost. A positioning gripper is a workpiece gripper integrated with welding technology, which can solve the problem of using industrial robots to complete the positioning welder sequence

take the automobile industry as an example, the rationalization requirements for positioning and tack welding

the automobile body is not only completed by welding large deep drawn steel plates to each other, but also by fixing hundreds of small shaped parts, such as classification plugs or ABS systems, seat fixtures, door and window hinges, distance finders, etc. Generally speaking, they should be reasonably positioned before resistance spot welding. This work is a headache for the production planning department. Due to the variety of parts and the often compact location, I can't imagine automating this positioning work. Therefore, the preparation before welding is mostly done manually. Design fixtures according to the actual application of elongation, or use non flexible special machinery. I sincerely hope that the control system of the experimental machine will be more perfect in the future! The disadvantages of the method are as follows:

- the planning and design costs of production tools are disproportionately high

- when rigid and non flexible production methods are used, if the shape and position of steel plate parts are changed in the production process, special equipment will be transformed

- in the production process, the positional tolerance of tack welding is often too large, which brings difficulties to the full mechanization of metal electrode gas shielded welding

- poor adaptability of manual operation in the workplace with forced production pace

- clamping device hinders the operation of welding work

- in order to carry out tack welding, it is necessary to increase the working position of the assembly workshop

ensure the experimental concentricity

- it is easy to get confused when the model is changed, and the wrong parts are positioned and welded

change the working mode

in order to realize the requirements of rationalization of the above work, the former staff of the franchoff Institute of production and automation technology (IPA) in Stuttgart developed a new production mode and required products. The result was the invention of plate arc tack welding with stroke arc striking, which was patented by the franhoff Institute in Munich. The positioning gripper developed with the industrial robot is mainly composed of standard parts. It is driven by 6BA compressed air, and the positioning welding process is adjusted by microprocessor. It is composed of the head of the positioning gripper, the welding power supply and the controller of the industrial robot. A tack welding program suitable for various weldments is set in the controller. Programmable welding parameters include:

magnitude and time of pre applied current

size and time of main welding current

size and time of welding stroke

pressing force

sinking depth

characteristic curve of stroke movement

in addition, the mechanical tensile strength test can be carried out with the help of the positioning gripper to achieve the purpose of quality control. If necessary, repeat the spot welding with a new spot welding piece. In order to control the process, there is a function to compare the theoretical value of welding parameters with the measured value, so as to keep it within the preset allowable tolerance range

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