JP4101778B2 - Injection mold equipment - Google Patents

Description

  The present invention relates to a mold apparatus used for injection molding of injection molded products such as bearing retainers.

  As shown in FIGS. 3 and 4, a conventional injection molded product such as a bearing retainer by injection molding is a thick product having a diameter of about 10 cm and a thickness of about 4 cm. An injection mold apparatus as shown in FIG.

  That is, as shown in FIG. 11, the mold apparatus for injection molding (shows a state where the mold is clamped and the mold is closed), the mold apparatus 3 includes a fixed-side mold member A and a movable-side mold. It is comprised from the member B.

  As shown in FIG. 11, the stationary mold member A is fixed to four tie bars 8 (see FIGS. 1 and 2) via four guide pins (see FIG. 8). And a fixed side template 10 in contact therewith. A sprue bush 11 a that introduces molten resin into the cavity C in alignment with the nozzle (injection port) of the injection head 2 is attached to the fixed side attachment plate 12 via a locating ring 13. In this conventional example, a single cavity C is provided.

  Further, a fixed insert 11 is fitted into the fixed-side template 10, and a recessed portion constituting one half of the cavity C is formed in the fixed insert 11.

  On the other hand, as shown in FIG. 11, the movable side mold member B is guided by four guide pins and moved in the horizontal direction by a driving device (not shown) to open and close the mold member to clamp the mold and open the mold. The movable-side mounting plate 36, the lower ejector plate 35 in which the ejector pins 37 are provided horizontally, and the upper ejector plate 34 that guides the ejector pins 37 are configured.

  Further, a movable insert 31 is fitted into the above-described movable side template 30, and a half portion of an injection molded product cavity C is engraved on the movable insert 31.

  Further, as shown in FIG. 11, the contact surface (parting surface) of the movable side template 30 with the fixed side template 10 has a predetermined width communicating with the cavity C and has a depth of An air vent groove 30a of about 0.01 mm, and an air vent groove 30d that communicates with the air vent groove, has a predetermined width for exhausting gas or the like from the cavity to the outside of the mold 3, and has a depth of about 0.2 mm. Is continuously provided to the outer edge of the movable side template 30.

  Then, the mold is clamped, the mold is closed, and when the fixed side mold plate 10 and the end face (parting surface) of the movable side mold plate 30 abut, the molten resin is injected into the cavity C from the sprue bush 11a, Gases and the like generated during injection molding from the air vent passages (air vent grooves 30a, 30b) formed in the direction of the parting surface are exhausted out of the mold 3.

However, in such a conventional mold apparatus, gas or the like from the air vent passage is not sufficiently exhausted, and therefore, the surface and the inside of the injection-molded product have sink marks (recesses due to air mixing), blisters (air Defects such as protrusions due to the formation of nests due to contamination and slag wells (a rough surface state due to impurities such as residues) occurred, and defective injection molded products were frequently generated.
JP 7-329128 A JP-A-11-34121

  Therefore, the present invention has been made in view of the problems of such a conventional injection mold apparatus, and further promotes the exhaust of gas etc. from the cavity, and has high accuracy and high quality without defects. It is an object of the present invention to provide an injection molding die device for molding an injection molded product with high productivity and high yield.

  In the mold apparatus for injection molding, an air vent groove communicating with the cavity end of the mold is provided in the parting surface of the movable side mold plate or the fixed side mold plate or both mold plates, and the air vent groove is arranged in the vertical direction. A gas escape hole is disposed in close proximity to the cavity, and gas is exhausted from the cavity through the air vent groove and the gas escape hole.

  The exhaust of the gas generated from the molten resin from the mold cavity is promoted, and an injection molded product free from defects such as sink marks, blisters, and slag wells can be obtained.

  First, FIG. 1 and FIG. 2 show an injection molding apparatus for molding the injection molded product M (for example, a bearing retainer) shown in FIG. 3 and FIG.

  The injection molding apparatus 1 is installed on the floor surface FL through vibration-proof rubber or the like, and moves horizontally on the main body of the injection molding apparatus 1 to move the injection port of the sprue bush ( An injection cylinder head 2 for introducing a molding resin (ABS resin, fluororesin, polycarbonate resin, etc.) such as nylon resin that has been joined and melted into the mold, and an operation screen device 4 for monitoring the injection molding operation; , A hopper 5 for supplying particulate nylon resin into the injection head 2, a chute 6 for storing an injection-molded product taken out from the injection mold, and a control panel 7 storing control equipment for the entire injection molding apparatus 1. And four tie bars 8 for attaching the injection molding die device 3 to the injection molding device 1 to perform a predetermined injection molding operation.

  Next, the injection mold apparatus 3 of the present invention will be described with reference to FIGS.

  FIG. 5 shows a state where the injection mold apparatus 3 of the present invention is closed and clamped, and this mold apparatus 3 is composed of a fixed mold member A and a movable mold member B. Yes.

  As shown in FIGS. 5 and 8, the fixed-side mold member A includes a fixed-side mounting plate 12 fixed to four tie bars 8 (see FIGS. 1 and 2) via four guide pins 40. , And a fixed side template 10 in contact therewith. A sprue bush 11 a that aligns the nozzle (injection port) of the injection head 2 and introduces the molten resin into the cavity C is attached to the fixed side attachment plate 12 via a locating ring 13. In the present embodiment, a single cavity C is provided. Here, a plurality of cavities C may be formed to obtain a large number.

  Further, a fixed insert 11 is fitted into the fixed-side template 10, and a recessed portion constituting one half of the cavity C is formed in the fixed insert 11.

  On the other hand, as shown in FIGS. 5 and 7, the movable mold member B is guided by the four guide pins 40 and moved in the horizontal direction by a driving device (not shown) to open and close the mold member. The movable side mounting plate 36 to be fastened, the lower ejector plate 35 in which the ejector pins 37 are provided horizontally, and the upper ejector plate 34 for guiding the ejector pins 37 are configured.

  Further, a movable insert 31 is fitted into the above-described movable side template 30, and a half portion of an injection molded product cavity C is engraved on the movable insert 31.

  Further, as shown in FIGS. 5 and 6 (partially enlarged longitudinal sectional view), a predetermined contact surface (parting surface) of the movable side mold plate 30 with the fixed side mold plate 10 communicates with the cavity C. A groove-like air vent groove 30a having a width of about 0.01 mm and a ring-shaped air vent groove 30b communicating with the air vent groove 30a and having a depth of about 0.2 mm are continuously provided. Has been.

Further, a plurality of, for example, four gas escape holes 33a and 33b having a diameter of about 6 mm are formed on the movable side mold plate 30 and the movable side receiving plate 33b so as to communicate with the annular air vent groove 30b. provided through the moving direction, the open end of the gas escape hole 33b is open to the space S formed between the upper ejector plate 34 and the movable receiving plate 32. The air vent grooves 30a and 30b are provided in the fixed-side mold plate 10, and the gas escape holes 33a are formed through the fixed-side mold plate 10 and the fixed-side mounting plate 12 so that the gas is exhausted from the cavity C. Also good. In addition, air vent grooves 30a and 30b and gas escape holes 33a may be formed in both the stationary and movable template plates 10 and 30 to exhaust gas from the cavity C, respectively.

As shown in FIG. 5, the gas generated from the air or molten resin in the cavity C communicates with the air vent groove 30a, the annular air vent groove 30b, and the vent groove 30b, and the gas escape holes 33a and 33b having a large flow area. The air is exhausted into the space S. Here, since an injection pressure of 1,000 kgf is applied per 1 cm ² of the injection product shape, these air vent portions are further compressed (powered up), and exhaust is promoted. In particular, since the gas escape hole 33a is provided as close as possible to the cavity C, the escape of gas is good, and defects such as sink marks, blisters, and slag wells are eliminated. % Decreased.

In FIG. 9, the injection molding is completed, the molded product M is cooled, the movable mold is retracted along the guide pins 40, and the mold is opened, and the injection having the sprue part M _{1 and the} extrusion pin contact part M ₂ . The state where the molded product M is left in the movable mold is shown.

FIG. 10 shows a state where the upper ejector plate 34 and the lower ejector plate 35 are moved in the mold clamping direction and the injection molded product M is pushed out from the mold by the push pin 37. The injection molded product extruded from the mold is stored in the chute 6 shown in FIG. Here, sprue portion M ₁ and the extrusion pin abutting portion M ₂ after release, is removed from the injection-molded article M.

  Since the gas generated from the molten resin can be completely exhausted from the cavity to the outside of the mold, it can be widely applied to injection molding of injection molded products that require precise dimensions and shapes.

The front view of the injection molding apparatus which mounted | wore with the injection die apparatus of this invention. The top view of the injection molding apparatus shown in FIG. The front view of the injection molded product (for example, bearing retainer) shape | molded by the injection die apparatus of this invention. IV-IV arrow sectional drawing of the injection-molded article shown in FIG. FIG. 2 is a cross-sectional view of the injection molding die device of the present invention taken along the line ZZ in FIG. 1 and shows a state in which the injection molding die is closed by closing. FIG. 6 is a partially enlarged longitudinal sectional view of a V portion shown in FIG. 5. The front view of the movable side metal mold | die of the injection die apparatus of this invention shown in FIG. The front view of the stationary side metal mold | die of the injection die apparatus of this invention shown in FIG. FIG. 4 is a longitudinal sectional view of the injection molding die apparatus of the present invention shown in FIG. 3, showing a state where the mold is opened after injection molding of the injection molded product. FIG. 4 is a longitudinal sectional view of the injection molding die device of the present invention shown in FIG. 3, after injection molding the injection molded product, opening the mold, extruding the injection molded product from the mold, and releasing the mold Indicates. It is a longitudinal cross-sectional view of the conventional injection mold apparatus, Comprising: The state which clamped and closed the metal mold | die is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection molding apparatus 2 Injection cylinder head 3 Mold apparatus 4 Operation screen apparatus 5 Hopper 6 Chute 10 Fixed side mold plate 11 Fixed insert 12 Fixed side mounting plate 13 Locating ring 30 Movable side mold plates 30a, 30b Air vent groove 31 Movable input Child 32 Movable side receiving plates 33a, 33b Gas escape hole 34 Upper ejector plate 35 Lower ejector plate 36 Movable side mounting plate 37 Extrusion pin 40 Guide pin A Fixed side mold B Movable side mold C Cavity S Space M Injection molded product

Claims (1)

An air vent groove of a predetermined width is formed on the parting surface of the movable side mold plate and directly communicated with the end of the mold cavity, and an annular air vent groove is connected to the air vent groove. On the other hand, in a space that is close to the cavity in the vertical direction and has a cross-sectional area greater than the cross-sectional area of the air vent groove, and an open end is formed between the upper ejector plate and the movable side receiving plate. multiple number of gas escape holes that opens the movable side mold plate and disposed in communication so as to penetrate in the direction of movement of the mold communicates with the atmosphere, with it, the from the cavity air vent groove, vent the annular groove and An injection mold apparatus for exhausting gas out of the mold by injection pressure through the gas escape hole.

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