Molds are really complicated for newcomers, and they may not be able to complete the understanding after 2-3 years of work. Personally, I suggest newcomers who are just entering the industry to familiarize themselves with the technical terminology of mold.
Then go to the workshop more, if possible, study with the master and quality inspection for 1-2 months, and then study with the order for 2-3 months. It is very helpful to quickly understand the mold.
1. The basic principle of injection mold:
Each mold is divided into two parts. The Cavity Part has only a cavity, and the Moving part has another cavity, a core part, and some have sliders. The simple working principle is that the Cavity part is fixed on the pressure plate of the injection molding machine near the injection nozzle. The fixed mold does not move during the entire injection process. The mold moves with the injection molding machine during the injection molding process. The plastic is melted by the high-speed rotation of the injection nozzle and screw of the injection molding machine, and then injected into the mold by high pressure, after cooling, the final product is formed. Plastic products, tables, stools, chairs, washbasins, storage boxes, etc. used in daily life. All are injection molding.
2. Introduce several simple mold structures:
1)The structure of the pusher plate: the product is left on the cavity plate of the movable mold, and the ejector rod of the injection molding machine pushes the movable mold cavity plate of the mold to eject the product.
This structure is suitable for round, such as in PVC pipe fittings, straight through, and plugs.
The advantage is that when this structure is ejected, the plate is evenly stressed, the ejection is stable, and there is no trace of the ejector pin on the product. The appearance of the product is beautiful.
2) Oblique guide column + side core pulling structure:
It is suitable for products with inner and outer holes and undercut shapes on plastic parts, but with a small core-pulling distance, such as tee and elbow products in plastic pipe fittings.
3) Hydraulic cylinder (Hydraulic Cylinder) core pulling structure:
It is suitable for products with inner and outer holes and undercut shapes on plastic parts, but with a large core pulling distance, such as the tee in plastic pipe fittings with a diameter of 110MM. Large molds generally use oil cylinders to pull cores.
The working principle is similar to that of the oblique guide column, except that the core-pulling structure needs to be replaced by a cylinder.
This structure: linear motion is stable, the output force is large, but the core pulling is slow, which lengthens the entire production cycle of the product. When operating the injection molding machine, pay attention to the sequence of core in and core out. The wrong sequence will cause damage to the mold.
4) There is an inverted core-pulling structure inside the injection molding machine:
A core-pulling structure of a write-to-plate mold with lock, including: entropy magic connecting plate, lock block, inclined guide plate, core-pulling slider, core-pulling slider guide, core-pulling slider positioning plate, lower mold connecting plate, upper The mold connecting plate is connected to the lock block, the inclined guide plate is installed on the lock block, the lock block is installed in the core-pulling slider, the core-pulling slider positioning plate is installed on the lower mold connecting plate, and the core-pulling slider positioning plate is installed on the puller. The core sliding block is installed on the guide rail of the core pulling block, the positioning plate of the core pulling block and the lower mold connecting plate constitute the sliding rail. When the core is pulled, the movable template and the fixed template are first driven by the power of the injection molding machine to open the mold. When the mold is opened, because the clamping pin under the fixed template is matched with the inclined slide groove of the flaring slider octahedron, the flaring slider is driven. The surface body slides outwards. Since the head of the flared large slider and the octahedron of the flared slider is in contact with the oblique dovetail groove, the octahedral sliding of the flared slider is equivalent to the flared large slider sliding down the oblique dovetail groove (radial When the large flared slide slides down, the large flared slide and the small flared slide are arranged to cross each other, so that the small flared slide is forced to slide down (shrink) at the same time, so that the large flared slide and the flared slide The small slider is demoulded from the flaring of the flared pipe, and the mold opening ends at this time.
The technical terms are more difficult to understand, and the easy-to-understand explanation is just like wearing a bracelet. It is impossible to wear a bracelet with five fingers spread out. First shrink your fingers before putting it on. After putting on the bracelet, stretch your fingers out.
The core of this structure is usually composed of a large number of small core pieces, and the processing is complicated, the processing accuracy is high, and the assembly workload is large.
