KR20080029038A - Ejector of plastic injection molding machine - Google Patents

Abstract

The present invention relates to an ejector of a compressed air injection method used in a plastic injection mold apparatus.

The ejector is a fixed side mounting plate, a fixed side template installed on a fixed side mounting plate, an upper mold inserted into the fixed side template, a spout bush inserted into the upper mold and a part installed at the inlet side of the spout bush, the injection nozzle is coupled Fixed die including a locating ring for providing a; movable side mounting plate, a movable side plate is installed on the movable side plate, a lower mold inserted into the movable side plate, and a guide pin for guiding the movement of the movable die The ejector is composed of an air blowing unit made of porous material and a pipe for delivering high pressure air to the air blowing unit so that the high pressure air is blown into the ejector. The air blowing unit is installed to be exposed to the cavity of the lower mold.

When the ejector according to the present invention is used, the structure of the plastic injection mold apparatus is very simple, and thus the development and production of the product is inexpensive. Also, the deterioration of the whitening phenomenon or the peeling of the resin coating on the surface of the molded article does not occur.

Description

Ejector for plastic injection molding apparatus

1 is a cross-sectional view of a conventional plastic injection mold apparatus.

2 is a cross-sectional view showing a state in which the movable die is retracted in the mold apparatus of FIG.

3 is a cross-sectional view showing a state in which the ejector pins take out the injection molded product in the state shown in FIG. 2;

4 is a cross-sectional view of an injection mold apparatus using the ejector according to the present invention.

5 is a cross-sectional view showing a state in which the movable die is retracted in the mold apparatus of FIG.

Figure 6 is a ejector according to the invention in the state shown in Figure 5 the ejected article

Section showing status.

7 is a sectional view of an ejector according to the present invention;

8 and 9 are partial cross-sectional views showing only the lower mold portion as another embodiment of the mold apparatus in which the ejector according to the present invention is used.

The present invention relates to an ejector for use in a plastic injection mold apparatus, in particular to an ejector of a compressed air injection method.

Conventional plastic injection mold apparatuses typically use an ejector which ejector pin (s) acts to bounce the cooled and solidified plastic injection molded product (see Korean Patent Publication No. 2005-0017224 or Utility Model Registration No. 0157548).

1 to 3 are cross-sectional views of a conventional rear injection mold apparatus in which a lower die flows, showing a state in which an injection product is taken out of a mold by using one ejector pin.

The rear injection mold apparatus includes a fixed die 100 and a movable die 200. The fixed die 100 includes a fixed side mounting plate 110, a fixed side die plate 120 installed on the mounting plate 110, and a fixed die mounting plate 110. The upper mold 20 to be inserted into the template 120, the spout bush 140 is inserted into the upper mold 20 and the inlet side of the spout bush 140 to provide a portion to which the injection nozzle is coupled It has a structure including the locate ring 150, the movable die 200 is movable side mounting plate 210, movable side template 220, the lower mold 30 is inserted into the template 220, movable The molten plastic is supplied to the cavity between the upper mold 20 and the lower mold 30 through the spout bush 140 to be molded. Spacer between the movable side mounting plate 210 and the movable side template 220 in a configuration for taking out the molded article 50 molded in the mold cavity The lock 250 is installed, and the upper ejector plate 260, the lower ejector plate 262, and the ejector pin 264 (shown with one ejector pin in the drawing, And a return pin 270 having a guide 266 for guiding the movement of the upper and lower ejector plates 260 and 262 and a spring 268 for returning the upper and lower ejector plates 260 and 262. It is provided.

As shown in FIG. 1, the mold apparatus is cooled and solidified by injecting molten plastic into the mold cavity as shown in FIG. 1, and the entire movable die 200 is fixed as shown in FIG. At this time, the molded product 50 is separated from the upper mold 20. In this state, the upper and lower ejector plates 260 and 262 are guided by the guide 266 as shown in FIG. The molded article 50 is taken out from the lower mold 30 by advancing by hydraulic pressure or pneumatic, and the ejector pin 264 moves forward to push the molded article 50. The extracted molded article 50 is a drawing device (not shown). When the extraction and withdrawal of the molded product 50 is completed, the upper and lower ejector plates 260 and 262 are initially positioned by the restoring force of the spring 268 provided on the return pin 270. Return to.

Conventional injection mold apparatus using the ejector pin (s) as described above, in addition to the ejector pin 264, the spacer block 250, the upper and lower ejector plates (260, 262), the spring 268 is provided with a return pin 270, In addition, since the hydraulic and pneumatic devices for driving the upper and lower ejector plates 260 and 262 should be provided, the structure is very complicated, and furthermore, when the molded part 50 takes the same structure, the development time of the mold and the product is long. In addition, the ejector pin 264 exerts a force on a certain portion of the molded part 50 to take out the molded part 50, so that the whitening phenomenon that often causes white marks on the surface of the molded part is caused by the impact. The quality of peeling or peeling off of the resin may occur. Also, since the ejector pin 264 is generally made of a steel bar having a small diameter, the ejector pin 264 may have a predetermined size. Can not be an output, there is also a case where bending of the take-out or broken.

The present invention is to solve the conventional problems, it is possible to simplify the structure of the injection mold apparatus, and to provide an ejector that does not cause a problem of deterioration of the injection molded product by applying evenly the ejection output to the whole injection product Has its purpose.

Ejector according to the present invention is fixed side mounting plate, the fixed side template is installed on the fixed side mounting plate, the upper mold to be inserted into the fixed side plate, the hot water inlet to the upper mold and the inlet side of the hot water to insert the injection nozzle A fixed die including a locate ring for providing a part to be coupled; a movable side mounting plate, a movable side template installed on the movable side mounting plate, a lower mold inserted into the movable side template, and a guide for guiding movement of the movable die. It is applied to a plastic injection mold apparatus composed of a movable die including a pin.

The ejector according to the present invention is composed of an air blower made of porous material and a pipe for delivering high pressure air to the air blower so that high pressure air is blown into the ejector, and the ejector is installed such that the air blower is exposed to the cavity of the lower mold. do.

In this case, a plurality of ejectors are installed so that the high pressure air is blown into the plurality of ejectors, and one ejector is preferably blown with a higher pressure air than the other ejectors. Even more preferred.

On the other hand, it is preferable that the air blowing part of the ejector is made of porous refractory material.

Hereinafter, the present invention will be described in more detail with reference to the embodiments illustrated in the accompanying drawings.

The ejector 300 according to the present invention employs a high pressure air injection method instead of using a conventional ejector pin as shown in FIG. 7. For this purpose, the ejector 300 includes an air blowing unit 310 and the air blowing unit. It is composed of a pipe 330 for transmitting the high pressure air to the 310. One end of the pipe 330 is formed with an air inlet 350 for introducing the high pressure air into the pipe 330 and the inlet ( 350, the high pressure air compressed by the compression pump is introduced.

The ejector 300 is installed such that the air blowing portion 310 is exposed to the cavity of the mold. FIGS. 4 to 6 are cross-sectional views of the rear injection mold apparatus to which the ejector 300 according to the present invention is attached. As shown, the air blowing unit 310 is installed to be exposed to the cavity of the lower mold 30.

In the case of the rear injection mold apparatus shown in FIGS. 4 to 6, the ejector 300 according to the present invention is used, and thus the spacer block 250 for driving the ejector pin 264 and the ejector pin as in the prior art, the upper and lower sides. The configuration of the device is greatly simplified by eliminating the need for an ejector plate 260 and 262, a return pin 270 with a spring 268, and a separate hydraulic or pneumatic device for driving the upper and lower ejector plates 260 and 262. In this case, the same reference numerals as those used in FIGS. 1 to 3 of the reference numerals used in FIGS. 4 to 6 indicate the same parts.

The air blower 310 is made of a porous material so that the high pressure air introduced into the pipe 330 flows out through the air blower 310. The air blower 310 is a lower mold 30. Since it is installed so as to be exposed to the cavity of the mold, it is in contact with the molten plastic injected into the mold cavity. Therefore, the air blowing part 310 must be made of a material that cannot be penetrated into the surface exposed to the cavity and must be made of molten plastic. do.

The porous material constituting the air blower 310 may be used as long as it is suitable for the above purposes, and one of the materials capable of achieving such a purpose is a porous refractory material. It is used when blowing argon, nitrogen, oxygen or a mixture of these gases into molten steel through a nozzle for bubbling molten steel. There are many kinds of such porous refractory materials, and representative examples thereof are Korean Patent Application 2000. -40918 consists of alumina 88 ~ 90% (wt%), silica 4.5 ~ 5.0%, zirconia 3 ~ 3.5% and chromite 1.5 ~ 1.8%, porosity 25 ~ 27%, average pore size 16 ~ 20㎛ Phosphorus alumina porous refractory. The porous refractory is an ejector according to the present invention because it can blow gas and also does not penetrate the molten steel upon contact with molten steel. There is no problem in using it as the air blowing part 310 of the 300.

The operation of the mold apparatus using the ejector 300 of the high-pressure air injection method according to the present invention is as follows. First, as shown in FIG. 4, molten plastic is injected into the mold cavity to cool and solidify the molded article 50. 5, the entire movable die 200 is retracted from the fixed die 100 as shown in FIG. 5, and the molded product 50 is separated from the upper mold 20, as shown in FIG. The high pressure air compressed by the compression pump (not shown) is introduced through the ejector 300-the inlet 350, the pipe 330, and the air inlet 310 (see Fig. 7)-to form the molded product 50. The molded product 50 separated from the lower mold 30 and finally separated is removed from the mold apparatus by a drawing apparatus (not shown), thereby completing one cycle, and then repeating the same process.

At this time, in the case of using the high pressure air injection ejector 300 according to the present invention, the high pressure air introduced through the air blowing unit 310 is formed between the molded part 50 and the bottom surface of the lower mold 30 according to the principle of Pascal. Therefore, unlike the case of using a conventional ejector pin, the whitening phenomenon occurs on the surface of the molded product, and the quality of the resin coating peeled off does not occur. Therefore, the air pressure blown accordingly can be set appropriately, which is very convenient and can be applied to various products.

On the other hand, in the case of using the conventional ejector pins, as in the case of using a plurality of ejector pins as needed, in the case of a high-pressure air injection type ejector according to the present invention, a plurality of ejectors may be used if necessary. 9 shows an embodiment using a plurality of ejectors (300, 300 ') is a partial cross-sectional view showing only the lower mold portion for convenience.

8 and 9, the ejectors 300 and 300 ', as described above, are composed of an air blower 310 made of a porous material and a pipe 330 for delivering high pressure air to the air blower 310, respectively. The air blowing unit 310 is exposed to the cavity of the lower mold 30. Also, the high pressure air is blown into these ejectors 300 and 300 ', but one ejector 300 is connected to the other ejector 300'. In comparison, in the illustrated embodiment, the high pressure air is blown into the ejectors 300 and 300 ', but the air pressure blown into the ejector 300 is greater than the air pressure blown into the ejector 300'. When the air pressure blown into the ejector 300 is greater than the air pressure blown into the ejector 300 'while using the plurality of ejectors 300 and 300' as described above, the high pressure air introduced through the ejectors 300 and 300 'may cause the molded product 50 to flow. In the final step of separating from the lower mold 30, the molded product 50 is compared The low pressure air is separated from the lower mold 30 while rotating in the direction of blowing, that is, the ejector 300 '. At this time, the drawing device 400 is drawn in the ejector 300' and waits for separation. The molded article 50 can be safely taken out. Using a plurality of ejectors and making a difference in the air pressure between the ejectors allows the molded article to be taken out in a desired direction, which is very convenient. The ejector in the embodiment shown in Figs. The difference in air pressure between the 300 and the ejector 300 'is preferably 1 atm or more.

In the above, air of different pressures were simultaneously injected through the ejectors 300 and 300 ', but initially air was injected through only one ejector 300', and for a predetermined time, for example, 1 second, the ejector 300 was used. High pressure air may also be blown. In addition, when only one ejector 300 is used, but the ejector 300 is positioned to be deflected from the center of the lower mold 30 to one side, a plurality of ejectors 300 and 300 'are used. It is also possible to obtain the same effect (the effect of peeling the molded product in the direction of the take-out device).

In the above description, the present invention has been described using a lower extraction molding apparatus, but it will be understood by those skilled in the art that the present invention can be used in any apparatus. The ejector according to the present invention injects high pressure air to those skilled in the art. It will be understood that various modifications are possible.

When the ejector according to the present invention is used, the structure of the plastic injection mold apparatus is very simple, and thus the development and production of the product is inexpensive. Also, the deterioration of the whitening phenomenon or the peeling of the resin coating on the surface of the molded article does not occur.

Claims (4)

Fixed side mounting plate 110, fixed side mounting plate 120 is installed on the fixed side mounting plate 110, the upper mold 20 to be inserted into the fixed side template 120, the spout bush inserted into the upper mold 20 And a fixed die 100 installed at the inlet side of the pouring hole 140 and including a locate ring 150 for providing a portion at which the injection nozzle is coupled; a movable side mounting plate 210 and a movable side. A movable die including a movable side template 220 installed on the side mounting plate 210, a lower mold 30 inserted into the movable side template 220, and a guide pin 240 for guiding movement of the movable die ( In the ejector used for the plastic injection mold apparatus consisting of 200), The ejector 300 is composed of an air blower 310 made of a porous material and a pipe 330 for delivering high pressure air to the air blower 310 so that the high pressure air is blown into the ejector 300, and the ejector ( 300 is the ejector of the plastic injection mold apparatus, characterized in that the air blowing portion 310 is installed so as to be exposed to the cavity of the lower mold (30). According to claim 1, A plurality of ejectors (300, 300 ') each composed of a porous material of the air blowing portion 310 and the pipe 330 for delivering the high pressure air to the air blowing portion 310, the lower mold 30 ) Is installed to expose the air blowing portion 310 to the cavity of the and the high-pressure air is blown into the ejector (300,300 '), one ejector 300 is more high-pressure air than the other ejector (300') Ejector of the plastic injection mold apparatus, characterized in that blown. The ejector of claim 1 or 2, wherein the air blowing portion (310) of the ejector (300) is made of porous refractory material. 3. The ejector of claim 2, wherein a difference in air pressure between the ejector 300 and the ejector 300 ′ is equal to or greater than 1 atmosphere.

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