Classification and function of casting molding machines

Classification and function of casting molding machines:

1、 Compaction molding machine

Use air pressure or hydraulic pressure to apply pressure to the molding sand in the sand box through a pressure head or pattern to compact the molding sand. The pressure is generally 0.25-0.4 MPa. This type of molding machine results in poor compaction of the sand mold away from the pressure surface. In the early 1950s, high-pressure molding machines emerged, with a pressure on the sand mold surface exceeding 0.7 MPa. The pressure heads of high-pressure molding machines are divided into several structural forms, including flat pressure heads, forming pressure heads, and multi contact pressure heads. Among them, high-voltage multi contact molding machines are the most widely used. The pressure head of the high-pressure multi contact molding machine is divided into many small blocks that can move up and down - contacts, which can achieve great compaction force through hydraulic cylinders. During compaction, each contact applies corresponding pressure according to the height of the pattern below it (i.e. the thickness of the compressed sand layer), resulting in a high and uniform compactness and hardness of the sand mold. These types of molding machines are equipped with micro shock mechanisms, which can adapt to complex shapes. High voltage multi contact molding machines often adopt a four column structure, with single station and dual station versions. 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 replacing the template, the molding machine does not need to be stopped. Adopting a high-pressure multi contact design, sand casting can produce thin-walled, accurately sized, and smooth surface castings.

2、 Shockproof molding machine

This type of molding machine can be divided into two types: shock and micro shock molding machines. The sand box and pattern are fixed on the workbench of the molding machine, and the inertia of the sand particles is used to compact the sand mold by colliding with the impact surface of the anvil when the workbench falls. This type of molding machine has severe noise and low compaction of the upper part of the sand mold, which has been replaced by micro vibration compaction molding machines.

3、 Shock compression molding machine

By further compacting the compacted sand mold, a compact sand mold can be obtained from the upper and lower parts. The commonly used is a micro vibration compaction molding machine (see figure), which uses the workbench to fall and collide with the floating vibrating iron, compact the molding sand with micro vibration, and then perform compaction. Microseism refers to the replacement of low-frequency (60-120 beats/minute) and large-amplitude vibrations of the shock molding machine with vibrations of higher frequencies (500-1000 beats/minute) and smaller amplitudes (5-25 millimeters). This type of molding machine produces high-quality sand molds and has lower basic requirements for molding machines.

Fully automatic horizontal molding machine

4、 Injection molding machine

It uses compressed air to evenly inject molding sand into the sand box for pre compaction, and then applies pressure for compaction. Commonly used are vertical parting box less injection molding machines and horizontal parting box removal injection molding machines. The vertical parting box less injection molding machine does not use a sand box for molding. The sand is directly injected into the molding chamber with a template, resulting in high dimensional accuracy. Due to the cavity on both sides of the sand box, the productivity is high, but it is difficult to lower the core, and the quality of the sand is strictly required. The horizontal parting and demolding injection molding machine uses sand boxes for molding. After the sand mold is made, it is easy to demould and demould, making it easier to lower the core and has high productivity.