Injection molding die of equal-diameter both-way plastic helical gear

Abstract

The invention discloses an injection molding die of an equal-diameter both-way plastic helical gear. The injection molding die sequentially comprises a fixed die seat plate, a pouring stopping plate, a mold core fixing plate, a cavity fixing plate, a movable die plate, a bearing plate, a mat block and a movable die base plate from top to bottom; a positioning ring is arranged above the fixed die seat plate; a first centripetal thrust bearing and a first helical gear cavity insert are arranged inside the cavity fixing plate; a second helical gear cavity insert, a second centripetal thrust bearing and a second mold core insert are arranged inside the movable die plate; and a bulb guide pin is installed inside the first helical gear cavity insert, a guide hole is formed inside the second helical gear cavity insert, and the first helical gear cavity insert and the second helical gear cavity insert are subject to helical gear groove position alignment through the bulb guide pin and the guide hole. The injection molding die is perfect in structure, efficient in motion and high in molding quality; multiple parting line sequenced parting achieves material coagulating of a gating system and automatic demolding of a helical gear plastic piece, the molding efficiency of the plastic piece is improved, and the service life of the die is prolonged.

Description

technical field [0001] The invention relates to a mold structure for injection molding of plastic helical gears, and more specifically relates to the design and application of a mold structure for injection molding of equal-diameter bidirectional plastic helical gears. Background technique [0002] Equal-diameter two-way plastic helical gear is a cylindrical gear with right-handed teeth on one part of the tooth width and left-handed teeth on the other part of the tooth width, commonly known as herringbone gears. The herringbone gear is equivalent to the combination of two helical gears. The structure is symmetrical, the diameter is equal, and the direction of the helix angle is opposite. It not only has the advantages of helical gears, but also overcomes the disadvantage of large axial force generated by helical gears. It has load-carrying capacity. High, stable transmission and small axial load, herringbone gear transmission is an important development direction of gear tra...

AI Technical Summary

Problems solved by technology

Aiming at the problem of demoulding after injection molding of herringbone gears (equivalent to bidirectional plastic helical gears with equal diameters), in current practice, mandrels are set in the movable and fixed molds respectively to form helical tooth grooves (the number of core rods is equal to the number of helical tooth grooves). Quantity), after the mold is opened, the connecting rod device drives the forming core rod of the helical groove to pull out obliquely, so as to realize the two-way core pulling of the movable and fixed mold, but the mold structure is complex, the parts processing is cumbersome, the assembly accuracy is low, and the molding quality is poor

[0004] There is also an injection mold structure that adopts two helical gear cavities to be embedded in combination, fixed mold plate rotation to push out, arc-shaped bent pins to reset, and movable mold core to rotate in two stages, but this structure has at least the following deficiencies: 1. On the fixed mold cavity It is difficult to process the guide hole of the curved pin; 2. It is difficult to control the consistency between the radian of the curved pin and the rotation angle of the fixed mold cavity; 3. The resistance of the core rotation is large and it is easy to wear; 4. It is not easy to ensure the rotation of the core The angle and speed are consistent with the helix angle of the helical gear; 5. The movement of the secondary push-out mechanism is not flexible

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