Plastic worm injection forming mold

Abstract

The invention provides a plastic worm injection forming mold. The worm injection forming mold comprises a stationary mold part and a movable mold part, wherein the stationary mold part comprises a demolding assembly consisting of a transmission mechanism and a sliding device; a stationary mold cavity of the stationary mold party, a worm cavity of the movable mold part, a movable mold cavity, and a movable mold insert are sequentially and tightly coupled to form a plastic worm cavity; an injection molding machine injects molten plastic in the worm cavity of the plastic worm mold through a hot runner system; the molten plastic is cooled and shaped to obtain the solid plastic worm. When demolding is performed, a hydraulic motor arranged in the injection molding machine and an oil cylinder arranged in the movable mold part drive the demolding assembly to separate the worm cavity and the molding insert from the plastic worm, and then the plastic worm can be taken down manually or by a manipulator. The mold is simple in structure, thin in the mold thickness, and capable of being mounted on a small precision injection molding machine to produce products. The product is excellent in various performances, high in precision, stable in size, short in production cycle and low in cost.

Description

technical field [0001] The invention relates to the field of mold manufacturing, in particular to a plastic worm injection molding mold. Background technique [0002] Plastic worms are widely used in modern industry. Plastic worms are often paired with worm gears to transmit motion and power between two staggered shafts. The worm transmission is equivalent to the screw transmission, which is a multi-teeth meshing transmission, so the transmission is stable and the noise is small. When the lead angle of the worm is smaller than the equivalent friction angle between the meshing teeth, the worm gear mechanism has a self-locking function. [0003] At present, the manufacture of plastic worms is mainly realized in the following two ways: [0004] 1. Use lathe for turning processing. The turning worm has a wide range of processing and is not limited by diameter. However, the efficiency of turning worm is relatively low, and it is mainly used in single-piece and small-batch produc...

AI Technical Summary

Problems solved by technology

[0004] 1. Use the lathe for turning processing. The turning worm has a wide range of processing and is not limited by the diameter. However, the efficiency of turning the worm is relatively low, and it is mainly used in single-piece and small-batch production.

Moreover, the processing quality mainly depends on the technical level of workers, the accuracy of machine tools and cutting tools. The size difference between single products is large, the accuracy is difficult to guarantee, and the cost is high. It is not suitable for mass production.

[0005] 2. Manufactured by injection mold, how to demould the plastic worm has been perplexing technicians in this technical field

At present, there are two methods in the mold manufacturing of plastic worms: one method is to set an appropriate number of sliders on the spiral surface of the worm for core-pulling and demoulding. This mold has a simple structure and can be used when the precision is low, but The splicing line left on the product when the sliders are matched will seriously affect the use of the product, and it is not suitable for high-precision products; another method is to use an integral worm sleeve on the spiral surface of the worm, and set the transmission mechanism to rotate Demoulding, this structure has no joining line on the surface of the product, such as the patent number "200810062449.5" published on October 29, 2008, "Plastic Worm Forming Mold", which uses an axial rotation drive mechanism driven by a sprocket , the mold structure in which the template is separated by the axial movement of the ejector worm and the product rotates and automatically falls from the worm cavity

Although the mold can be demolded smoothly, the transmission mechanism of the demoulding component is complex, resulting in low efficiency; the cold runner glue feeding method and complex transmission mechanism lead to a large mold thickness, which requires a large injection molding machine and high production costs ;During the operation of the transmission mechanism, the backlash between the outer thread of the ejector screw and the central thread of the ejector screw gear cannot offset the cumulative backlash of the ejector screw gear, idler gear, and movable mold insert gear, resulting in the worm cavity plate The movement and the rotation of the movable mold insert gear cannot be completely synchronized, and the product accuracy is difficult to control

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