vacuum aluminum brazing furnace structure
In order to better describe the electrical control system, the mechanical structure of this type of vacuum aluminum brazing furnace is first introduced. The main body of vacuum aluminum brazing furnace is composed of heating chamber, furnace body, front and rear furnace doors and various functional components. The heating chamber is installed in the furnace body, which is composed of multiple heating resistances and insulation layers. The heating resistances are connected by external electrodes and cables to form 28 heating cells. Each cell is powered by a set of silicon controlled voltage regulating power circuit. The furnace body is a double-layer water-cooled jacket structure, on which are welded with the necessary functional components of the brazing furnace, and the front and rear furnace doors to form a vacuum chamber: the front and rear furnaces The door is also a double-layer water-cooled jacket structure, which is respectively installed on the furnace door car which can translate along the vertical direction with the furnace axis. The furnace door can also translate along the axis direction of the furnace body driven by the cylinder on the furnace door car. The translation of the two directions of the furnace door enables the furnace door to open and close.
The peripheral system of vacuum brazing furnace includes vacuum system, water cooling system, air charging system, pneumatic system and charging car outside the furnace.
The requirements of aluminum alloy brazing on vacuum system are very high. The vacuum system should not only have a strong enough ability to obtain vacuum, but also have enough ability to ensure that the vacuum degree in the furnace is kept at 10-3 PA when a large amount of gas volatilizes, which requires the vacuum system to have a fast and stable pumping speed. The vacuum unit of this type of vacuum brazing furnace is equipped with 5 sets. Each set of vacuum unit is equipped with: the main pump is a high vacuum oil diffusion pump, which belongs to a steam jet pump. It has the advantages of large pumping speed and high limit vacuum. The mechanical pump unit is used for pre pumping vacuum and as a pre-stage pump of diffusion pump, which is composed of roots pump and slide valve pump. The maintenance pump is a rotary vane pump, It can ensure a certain degree of vacuum in the pump cavity when the diffusion pump is pre heated before the equipment starts to work, and also can ensure that when the roots pump and slide valve pump are stopped to save energy during the cooling process of the diffusion pump after the completion of the work, the diffusion pump oil will not be oxidized; the valves of each vacuum unit include the large valve, the front valve, the pre pumping valve and the unit vent valve. Water cooling system is used for cooling furnace wall, diffusion pump, roots pump, slide valve pump and vane pump. Electric contact water pressure gauge shall be installed for the main water inlet pipe, and alarm shall be given when the water supply pressure is insufficient. All water flows through the cooled parts to the return tank, which is connected with the main return pipe. The equipment is equipped with inert gas charging interface, and equipped with manual ball valve, manual needle valve and other devices. According to the need, nitrogen replacement can be realized in the pre vacuum stage.
The equipment is equipped with a pneumatic system, which is composed of air source triplets, pipelines and seals. The pipeline of the pneumatic system can bear a pressure of 0.8-1 MPa, which is used for the components driven by the air cylinder on the equipment, including the large valve, the front valve, the pre extraction valve and the front and rear furnace doors. The workpiece cart is used for loading and unloading the workpiece. Its main body is the frame. The size of the frame matches the maximum size of the workpiece after loading, which is enough to bear the total mass of the load in the structural strength. The track fixed on the ground is used to support the frame and guide the movement of the frame. The forward and backward of the frame is driven by the deceleration motor (Power: 2.2kW) fixed in the pit. The frame moves towards the furnace body to realize the docking of the guide rail on the frame and the guide rail of the square section in the heating chamber. The other group of deceleration motor (Power: 2.2kW) fixed on the frame can drive along the guide rail The moving work-piece Trailer moves forward and backward, making the work-piece moving together with the roller assembly move in and out along the guide rails in the furnace and on the frame, so as to realize the loading and unloading process. The movement of the frame and the in and out of the furnace of the workpiece have the limit position of the travel switch to realize the accurate docking of the guide rail and the in and out of the furnace of the workpiece.