Molding device with cutting mechanism

1. Technical Field

The present disclosure relates to molding devices, and a molding device with a cutting mechanism.

2. Description of Related Art

To manufacture plastic products, plastic in liquid form is injected into a mold cavity. The molten plastic hardens as it is cooled in the mold cavity to form the product. Excess plastic known as flash may be attached to the product after molding. A sprue gates is formed in the mole cavity. The sprue gates are often manually cut or ground away after the plastic is ejected out of the mold cavity. This can be time-consuming and prone to human errors. The product may be damaged if the mold cavity is not removed properly. Therefore, there is room for improvement in the art.

Many aspects of the embodiments can be better understood with references to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an isometric exploded view of a cutting mechanism in one embodiment.

FIG. 2 is an assembled view of the cutting mechanism of FIG. 1 .

FIG. 3 is an isometric view of a molding device in one embodiment.

FIG. 4 is a cutaway, cross-sectional view of the molding device of FIG. 3 , taken along the line IV-IV.

FIG. 5 is an enlarged view of the circled portion V of FIG. 4 .

FIG. 6 is a cutaway, cross-sectional view of the molding device of FIG. 3 , taken along the line VI-VI.

FIG. 7 is an enlarged view of the circled portion VII of FIG. 6 .

The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.

FIG. 1 shows a cutting mechanism in accordance with an embodiment. The cutting mechanism 50 includes a cutting seat 10 , a cutter 20 rotatably engaged in the cutting seat 10 , two elastic members 30 received in the cutting seat 10 , and a plurality of balls 40 attached to the cutting seat 10 .

The cutting seat 10 includes a top wall 11 , a front wall 13 , a rear wall 14 , and two sidewalls 15 . The cutting seat 10 defines an elongated latch slot 111 extending to the top wall 11 and the two sidewalls 15 . The latch slot 111 includes a narrow portion 1111 and a wide portion 1113 communicating with the narrow portion 1111 . A width of the wide portion 1113 is greater than a width of the narrow portion 1111 . The wide portion 1113 has an inner wall, and the inner wall is substantially arc-shaped. The cutting seat 10 defines two receiving slots 113 extending to the top wall 11 , to receive the two elastic members 30 . The two receiving slots 113 are adjacent to the two sidewalls 15 , respectively. The latch slot 111 extends through a center of each of the two receiving slots 113 .

Each of the front wall 13 and the rear wall 14 defines two first engaging slots 131 . Each of the two sidewalls 15 defines a second engaging slot 151 . The two first engaging slots 131 and the second engaging slot 151 have a same configuration, and each of the two first engaging slots 131 and the second engaging slot 151 includes an engaging portion 1311 and a cutout 1313 communication with the engaging portion 1311 .

The cutter 20 includes a plate body 21 and a latch shaft 23 located on the plate body 21 . The plate body 21 is rectangular. The latch shaft 23 is substantially columnar and has a cross-section. A thickness of the plate body 21 is smaller than a diameter of the cross-section of the latch shaft 23 . The latch shaft 23 is located on a first end of the plate body 21 , and a second end opposite to the first end of the plate body 21 defines a cutting edge 211 .

Referring to FIG. 2 , in assembly, the latch shaft 23 of the cutter 20 is aligned with the wide portion 1113 of the latch slot 111 , and the plate body 21 is aligned with the narrow portion 1111 of the latch slot 111 . The cutter 20 is moved towards the cutting seat 10 , until the latch shaft 23 is received in the wide portion 1113 . A part of the plate body 21 is received in the narrow portion 1111 and another part of the plate body 21 extends out of the cutting seat 10 . The cutter 20 can swing relative to the cutting seat 10 , around the latch shaft 23 . An outer surface of the latch shaft 23 abuts against an inner surface of the wide portion 1113 . The two elastic members 30 are received in the two receiving slots 113 , respectively. One end of each of the two elastic members 30 is attached to a bottom wall of each of the two receiving slots 113 , and another end of the two elastic members 30 extends out of the cutting seat 10 .

Each of the balls 40 is engaged in the engaging portion 1311 . After each of the two first engaging slots 131 and the second engaging slot 151 is full with the balls 40 , two side ends of each of the two first engaging slots 131 and the second engaging slot 151 are weld, to prevent the balls 40 from disengaging from the corresponding engaging slot. The cutting mechanism 50 is thereby assembled completely.

Referring to FIGS. 3-7 , the cutting mechanism 50 is applied to a molding device in one embodiment. The molding device further includes a male die 60 , a male die core 61 , a master die core 65 , an oil connection 70 , an oil body 80 , and a piston module 90 . The male die 60 defines an installation hole 601 . The male die core 61 is sandwiched between the male die 60 and the master die core 65 and defines a through hole 611 corresponding to the installation hole 601 . The male die core 61 and the master die core 65 cooperatively define a mold cavity 100 . One end of the oil connection 70 is secured to the oil body 80 and received in the installation hole. The piston module 90 is received in the oil body 80 and abuts against a bottom portion of the cutting mechanism 50 . The cutting mechanism 50 is received in the through hole 611 . The cutting edge 211 of the cutting mechanism 50 is adjacent to the mold cavity 100 and the plurality of balls 40 abuts the sidewalls of the through hole 611 .

After plastic, in liquid form, is injected into the mold cavity 100 , a plastic product 200 is formed. A sprue gate 101 of the plastic product 200 requires cutting. Oil is injected into the oil connection 70 , to move the piston module 90 . The piston module 90 pushes the cutting seat 10 , the two elastic members 30 are resiliently deformed to abut a top wall of the through hole 611 . The plurality of balls 40 of the cutting mechanism 50 abut against the sidewalls of the through hole 611 to decrease friction force between the cutting seat 10 and the sidewalls of the through hole 116 . The cutting seat 10 biases the cutter 20 to cut the gate mark. After the gate mark is cut, the oil connection 70 will stop injecting oil. The plate body 21 is movable relative to the cutting seat 10 around the latch shaft 23 , to prevent the cutting edge 211 from sticking with the sprue gate 101 . The two elastic members 30 rebound to move the cutter 20 to disengage the cutting edge 211 from the sprue gate 101 .

It is to be understood, however, that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, together with details of the structures and functions of the embodiments, the disclosure is illustrative only and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.