JPS5836520Y2 - injection molding equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to an injection molding device, and more specifically, the present invention relates to an injection molding device, and more specifically, the air in the molding cavity is discharged before injection of the molding material, and a part of the molding material is exhausted during the injection of the material. To provide an injection molding apparatus that is equipped with an air exhaust means that can prevent air from being sucked into a ventilation hole provided for the purpose.

In injection molding, in which thermoplastic or thermosetting material is injected into the cavity of a mold, the air inside the molding cavity must be kept in order to prevent air bubbles inside the product and dents on the surface. Means for discharging molding material prior to injection of molding material is widely used.

Generally speaking, the means for discharging the air inside the cavity is such that an air discharging device such as a vacuum pump is connected to the molding cavity to suck the internal air. Problems such as part of the molding material being sucked into the air suction means remain.

In order to solve the problems with the air exhaust means according to the prior art described above, the present invention has been developed by arranging an intake manifold adjacent to the end of the mold opposite to the material injection side, and installing a material injection port inside the mold. An air inlet opening to the side, an intake hole connected to the air inlet and extending toward the intake manifold side, and a valve head that is located inside the molding cavity and has an approximately disk shape, and a rod-shaped valve that extends from the valve head. a valve body comprising a body;
The valve head is inserted into the mold so as to be movable in the axial direction, and closes the air inlet that constitutes a part of the degassing means consisting of the air inlet, the intake hole, the spring means insertion hole, the ventilation hole, and the outlet. Furthermore, an air passage is bored in the intake manifold so as to correspond to the vent hole provided in the mold, and to correspond to the rod-shaped body of the valve body inserted into the mold. A compressible spring means is installed in the recess provided in the above to support the end of the rod-shaped body, and the air passage provided in the intake manifold is connected to an air exhaust device such as a vacuum pump, and the molding material is injected. In the front, the valve body is supported by spring means in the intake manifold to keep the valve open, and the air in the molding cavity flows through the air inlet and intake hole provided in the mold, and the intake manifold. The air is sucked into the external air exhaust device through the air passage, and the inside of the molding cavity is maintained at a reduced pressure.When the molding material is injected, the valve body is pushed by the injection pressure acting on the valve head and becomes rod-shaped. The tip of the body moves while compressing the spring means, and the valve head closes the air suction port to prevent part of the injected molding material from being sucked into the air suction port, and further molding is performed. When the product is separated from the mold after completion, the valve body is pushed by the elastic force of the spring means to return the air suction port to the open state and suck the air inside the molding cavity for the next molding. This is what you do.

Embodiments of the injection molding apparatus according to the present invention will be described below based on the drawings.

In the embodiment of FIG. 1, the injection molding apparatus includes an upper mold 1 and a lower mold 1 which are combined with each other to form a molding cavity 2.
0, an upper mold retainer 4 into which a plurality of upper molds 1 are fitted;
A lower mold retainer 11 into which the lower molds 10 arranged so as to correspond to the upper mold 1 are fitted. Distribution board 5 joined to upper mold 1
, and an intake manifold 20 joined to the lower mold 10, the distribution board 5 and the upper mold 1 are provided with runners 8 that communicate with the molding cavity 2, and the distribution board 5 has a connection between the runners 8 and the outside. A communicating spool 7 is provided (
2), the lower mold 10 and the intake manifold 20 include an air intake port 12 that opens into the molding cavity 2 and communicates with the outside, an intake hole 15, a spring means insertion hole 22, and a ventilation hole 2.
Gas venting means 12, 15, 2 consisting of 4 and a discharge port 25
2, 24, and 25 are provided.

Specifically, the lower mold 10 has an air suction port 1 located approximately in the center.
2 is provided, and the valve guide hole 1 is kept concentric with the air suction port 12.
4, and an intake hole 15 that is substantially parallel to the valve guide hole 14 is bored toward the intake manifold 20 side, and is located inside the molding cavity 2 and has a substantially disc-shaped valve head 18 and a rod-shaped valve head 18. A valve body 1 consisting of a rod-shaped body 19 extending from a head 18
7 is configured such that the end of the rod-shaped body 19 protrudes from the end surface of the lower die 10, and the rod-shaped body 19 is inserted into the valve guide hole 14 so as to be movable in the axial direction, and the air suction port 12 is inserted by the valve head 18. The intake manifold 20 is provided with a spring means insertion hole 22 so as to correspond to the rod-shaped body 19 protruding from the end surface of the lower mold 10. A spring means 23 that elastically supports the rod-shaped body 19 of the valve body 17 is inserted into each spring means insertion hole 2.
As shown in FIG. 3, the air intake manifolds 2 communicate with each other through vent holes 24 and are connected to an air removal device through an outlet 25 on the end face of the intake manifold 20.

In the spring means insertion hole 22, as shown on the left side of the enlarged view of the main part in FIG. A stop ring 32 for stopping the spring receiving plate 27 is attached to elastically support the rod-shaped body 19 protruding from the end surface of the lower die 10.

For molding using the injection molding apparatus configured as described above, the upper mold 1, the lower mold 10, the distribution board 5, and the intake manifold 20 are assembled as shown in FIG. Vent hole 24 of manifold 20
, through the air intake hole 15 of the lower mold 10, into the molding cavity 2.
The air inside is sucked out, and the molding material is injected by an injection means (not shown), and is forced into the molding cavity 2 through the spool 7 and runner 8 to be molded.
At that time, the valve body 17 and the valve head 18 are pressed against the molding material,
The air suction port 12 descends against the spring force of the compression spring 31.
to prevent a portion of the molding material from being forced into the air inlet 12.

A part of the molding material comes to cover the valve head 18 of the valve body 17, but when the molding process is completed and the upper mold 1 and lower mold 10 are separated to take out the product, the valve head 18 A part of the molding material covering the valve head 18 is removed together with the product, and
Enables execution of the next molding process.

The shape of the valve head 18 of the valve body 17 can be changed by forming an annular projection with an acute cross section on the outer end, as shown in FIG. 5, instead of the disk shape shown in FIG. The ability to prevent material from entering the air inlet 12 can be further ensured.

The arrangement of the spring means insertion holes 22 in the intake manifold 20 is shown in FIG. 3 according to the number of molds (4) shown in FIG.
However, as illustrated in FIG. For one number of
There are two arranged vertically on the diagram (symbols b1 and b on the diagram).
2), and four pieces arranged radially in all directions for one piece in the center part (marked with C□, C2,
C3, C4) etc. are placed as appropriate, and if the number of products to be molded simultaneously is 4, retainer 4
, 11, the arrangement of the upper mold 1 and the lower mold 10 corresponds to the arrangement of C1, C2, C3, and C4 of the spring means insertion hole 22, and when the number is three, the arrangement of a, l), and b2. By making it possible to select as appropriate, such as making it correspond to the arrangement of bl and b2 when the number is two, and making it correspond to the arrangement of a when the number is one, one type of intake manifold can be created. 20, it is possible to adapt to production of 1 to 4 pieces, or even an appropriate number of pieces.

In this case, there is no corresponding mold and the spring means insertion hole 22 is in an idle state (for example, in a four-piece mold, a, b
I, b2), as shown on the right side of the enlarged view of the main part in FIG. 4, a blind lid 34 with a seal ring 35 is inserted to maintain airtightness.

The air suction port 12 for discharging the air in the molding phase cavity 2 is provided opposite the runner 8 into which the molding material is injected, and the valve body 17 is supported by a compressible spring means 23. ,Easier due to injection pressure during material injection,
Moreover, the air suction port 12 can be completely closed and a part of the molding material can be prevented from being sucked into the air suction port 12 side. A portion of the molding material is removed at the same time as the product is demolded, allowing the molding process to continue.

[Brief explanation of drawings]

Fig. 1 shows an injection molding apparatus according to the present invention with arrow I on Fig. 3.
-I is a cross-sectional view of the cut plane indicated by I, Fig. 2 is a plan view as well, and Fig. 3 is a plane view of the intake manifold at the position indicated by arrow I■■-■■■ on Fig. 1. Figure 4 is an enlarged cross-sectional view of the main part at the cut plane indicated by the arrow ■■-I■ in Fig. 6, Figure 5 is an enlarged cross-sectional view of the main part at the air suction port of the lower mold, The figure is a plan view showing another embodiment of the intake manifold. 1... Upper mold, 2... Molding phase cavity, 4... Retainer for upper mold, 5... Distribution board, 7... Spool, 8...Runner,
10... Lower mold, 11... Lower mold retainer, 12... Air suction port, 14... Valve guide hole, 15...・Intake hole, 17... Valve body, 18... Valve head, 19... Rod-shaped body, 20... Intake manifold, 22...・
... Spring means insertion hole, 23 ... Spring means, 24
...Vent hole, 25...Exhaust port, 27.
...Spring receiving plate, 28...Communication hole, 31.
...Compression spring, 32...Stop ring, 34...Blind lid, 35...Seal ring.

Claims (1)

[Scope of utility model registration request] A distribution board 5 is disposed on the upper mold 1 side of molds 1 and 10 consisting of an upper mold 1 and a lower mold 10, and an intake manifold 20 is disposed on the lower mold 10 side. In an injection molding apparatus, a molding cavity 2 is formed in the upper mold 1, and a runner 8 is formed in the upper mold 1, and a runner 8 is formed in the lower mold 10. Gas venting means 12, 15 communicating with
, 22, 24, 25, and a valve head 18 supported by a spring means 23 and a valve body 17 which is hollowed out from a rod-shaped body 19 are disposed at a position facing the runner 8.
An injection molding apparatus characterized in that a valve head 18 is located within the molding cavity 2 and opens and closes the gas venting means 12, 15, 22, 24, and 25.