1. For the manufacture of sand type casting equipment, its main function is: sand filling, filling loose sand into the sand box; compacting sand, making sand by different methods such as shaking, compaction, shock pressure and injection pressure The loose sand in the box is compact, so that the sand mold has the necessary strength in the process of handling and pouring; the mold is taken out, and the pattern is taken out from the compacted sand mold by different mechanisms. The molding machine first appeared in the mid-19th century. The early molding machine was a simple manual compaction belt demoulding mechanism, and later compressed air was used as the power for the compacted and compacted sand. In 1890, a shock-type molding machine appeared, which improved the modeling efficiency and sand accuracy. The molding machine can be divided into shock pressure type, earthquake type and compact type according to the method of compacting sand.
2. Seismic molding machine The compacted sand mold can be compacted to obtain a tight sand pattern. Commonly used is the microseismic compaction molding machine (see micro-shock compaction molding machine), which uses the falling of the table to collide with the floating shock iron, and the micro-shock compact sand, and then compact. The microseismic vibration is based on the high frequency (500 to 1000 beats/min) and the small amplitude (5 to 25 mm) vibration to replace the low frequency (60 to 120 beats/min) of the shock type molding machine and the large amplitude vibration. The sand mold produced by this molding machine has good quality and low basic requirements.
3. Seismic modeling machine This horizontal boxless automatic molding machine can be divided into two types: shock type and micro shock type molding machine. The sand box and the pattern are fixed on the table of the molding machine, and the sand type is compacted by the collision of the table when the table falls and the collision surface of the anvil. This type of molding machine is very noisy, and the compactness of the upper part of the sand-making type is very low, and has been replaced by a micro-shock compaction molding machine.
4. Compaction molding machine Use the air pressure or hydraulic pressure to apply pressure to the molding sand in the sand box through the indenter or the pattern to compact the molding sand. Its pressure is generally 0.25 to 0.4 MPa. This type of molding machine makes the sand type tightness away from the pressure applying surface. A high-pressure molding machine appeared in the early 1950s, and the pressure on the sand plane was above 0.7 MPa. The pressure head of the high-pressure molding machine is divided into several structural forms such as a flat pressing head, a forming indenter and a multi-contact indenter. Among them, the high-pressure multi-contact molding machine is the most widely used. The high-pressure multi-contact molding machine head is divided into a number of small squares that can move up and down—contacts, which can obtain a large compressive strength through hydraulic cylinders. In real time, each contact applies a corresponding pressure according to the height of the pattern below it (ie, the thickness of the pressed sand layer), so that the sand type obtains a high, uniform compactness and hardness. These molding machines are equipped with micro-shock shock mechanisms that can adapt to complex shapes. The high-pressure multi-contact molding machine adopts four-column structure, and has single-station type and double-station type. In order to adapt to the production of small and medium-sized castings, this type of molding machine is often equipped with a template quick change device. When the template is replaced, the molding machine does not need to be shut down. With high-pressure multi-contact molding, sand casting can cast thin-walled, accurate-sized, smooth-surfaced castings.
5. Injection type horizontal boxless automatic molding machine It uses compressed air to uniformly inject the molding sand into the sand box to pre-compact, and then apply pressure to compact. Commonly used are vertical split type boxless injection molding machine and horizontal type off-box injection molding machine. The vertical split type boxless injection molding machine does not use a sand box, and the molding sand is directly injected into the molding room with the template. The sand making type has high dimensional accuracy. Because the sand box has cavities on both sides, the productivity is high, but the lower core is difficult. The quality of the molding sand is strict. The horizontal type off-box injection molding machine uses the sand box for modeling, and the sand type is formed after the mold is unpacked, the lower core is convenient, and the productivity is high.