Welding technology of silicon steel sheet core and low carbon steel of frequency conversion external rotor motor

The price of the control principle diagram of the frequency converter is about tens of yuan, and its circuit is simple and reliable.

The potentiometer can be programmed by software in a wide range to control the speed of the three-phase induction motor. The brief introduction is as follows: First, select the three output terminals of the programmable controller (the basic unit is the relay output) to disconnect the input terminal of the relay control line in the programmable controller, and connect it to the optocoupler input terminal as shown in the figure. The optocoupler output is connected to three input control terminals of e2pot non-volatile digital potentiometer X9313: 5, 1 "5 (optional high-speed counting output if necessary), so that it can be passed by a programmable controller VFD-M frequency conversion speed controller is flexible and convenient to control the speed of three-phase induction motor.

To make full use of the function of the frequency converter, other relay output terminals of the programmable controller can be used to control the multi-function input terminals M ~ M5 of the frequency converter, so that the forward and reverse rotation of the three-phase induction motor can be automatically achieved. Turn, stop, abnormal reset, multi-speed and other functions.

In practical applications, the use of E2POT non-volatile digital potentiometer can receive the effect of reducing costs, simplifying programming and interface circuits, thereby improving system stability and intelligence. The typical method of using a programmable controller to control a variable frequency speed regulator is to add a D / A conversion unit to output an analog quantity. The general price of a D / A conversion unit is about two thousand yuan, and the welding process of a silicon steel core and low carbon steel of an e2pot non-volatile frequency conversion external rotor motor Li Jun \ Shen Hongmou 2 (1. Zhejiang Taizhou Vocational and Technical College Feng Branch, Huangyan 3180207; 2. Zhejiang Speed ​​Control Motor Factory, Tongxiang 314500) The frequency conversion outer rotor permanent magnet motor silicon steel sheet core produced by our factory, the surrounding reinforcement bars (as shown in the figure) were originally made of stainless steel and welded by argon arc welding , The process is complex and the cost is high. Later, the low carbon steel plate is used as the rib, and the 422 electrode is used for manual arc welding. After repeated experiments, the mechanical properties of the welded joint basically ensured the technical requirements, which not only reduced the cost, but also improved the efficiency and saved the raw materials. The core structure of the frequency conversion outer rotor permanent magnet motor now introduces the welding process as follows.

1 Problems and countermeasures during welding 2%. The low carbon steel plate welded with the 422 electrode has a Si content in the weld. However, Si has a large solid solution strengthening effect on ferrite. If the content of the weld is increased The amount of Si will increase the yield strength and tensile strength of the weld metal, while the impact toughness will decrease. Therefore, the Si content in the weld must be strictly controlled during the welding process, otherwise the mechanical properties of the joint will be deteriorated. Therefore, in the welding process, it is necessary to select the appropriate welding specification and reduce the fusion ratio as much as possible to reduce the content of Si in the weld.

2 Welding process Preparation before welding should be performed in a dry environment at room temperature above 5C, and avoid ventilation. Clamp the core of the silicon steel sheet before welding; remove the oil and rust on the base material. The electrode is dried at 250C ~ 300C before welding and kept for 2 hours, and placed in an oven for immediate use.

2mm electrode, current is 110 ~ 130A (fillet weld) welding method manual arc welding has a small fusion ratio, which is safer, so manual arc welding multi-layer welding method, the welding slag needs to be removed after each weld, The work piece is inclined as little as possible to speed up the welding speed.

After welding, hit the weld with a small pointed hammer to eliminate the stress.

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