JP2010094937A - Side valve gate type hot runner system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve gate type hot runner system for a product to be required to arrange a gate on the side face thereof. <P>SOLUTION: The valve gate type hot runner system has such a mechanism that a molten resin is injected from a molding machine 5, made to pass through a sprue bush 1 of the hot runner system, a manifold block 2, a nozzle 3 and a side nozzle 4, packed in a product part and molded. The mechanism has such a structure that a piston 6 of a cylinder arranged on the side face of a fixed side retainer plate is operated to move a valve pin 7 just before the molten resin is injected from the molding machine 5, a gate hole 27 at the tip 21 of the gate arranged on the side face of the product is opened to pack the molten resin in the product part, and then the opened gate hole is closed by operating the piston 6 of the cylinder to move the valve pin 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a side valve gate type hot runner system for injection molding capable of injecting molten resin from a side surface side of a cavity.

  Conventionally, in a cold runner system method (see FIG. 2) in which molten resin is injected through a runner to produce a product and filled from the side of the cavity, the resin is obtained by using, for example, a three-plate mold base. Molten resin was injected into the flow path and the cavity. In such a cold runner system method, after cooling and solidification, the product is taken out, and at the same time, other than the product solidified in the resin flow path other than the cavity, for example, sprue (23), runner (24), sub-runner (12). I had to take out the extras.

In the cold runner system described above, if the diameter of the portion (A) in the right enlarged view of FIG. 2 is increased, the portion (A) may not be cut when the mold is opened. Further, when the portion (B) in the right enlarged view of FIG. 2 is enlarged, the area that needs to be finished in post-processing increases, and finishing takes time and labor.
On the other hand, in proportion to the size of the product, if the gate holes in the (A) and (B) parts of the enlarged view of FIG. The resin will not reach and the product will be defective. For this reason, it is necessary to install many gates, and there is a problem that the number of runners that become industrial waste increases. In order to suppress the pressure loss, it is necessary to enlarge the gate hole, but there is a trade-off relationship that post-processing work is required accordingly.

  On the other hand, in the hot runner system, a technique for performing gate cut by raising and lowering a valve pin in the vertical direction has been known. By combining such a hot runner system with a cold runner system method for filling molten resin from the side of the cavity, the hot runner system method shown in FIG. 3 can be considered.

In the hot runner system shown in FIG. 3, a heater (47) and a gate pin (37) moving up and down in the vertical direction are installed on the runner (34) upstream of the sub runner (12), and the sub runner (12) is interposed. In this system, the cavity (38) is filled with molten resin.
In the hot runner system method in which the molten resin is filled from the side of the product part, the hot runner gate hole (41) can be installed at the entrance of the sub runner (12) because the hot runner gate hole cannot be installed in the product part. The molten resin is injected into the cavity (38) through the sub runner (12).

Therefore, after cooling and solidifying the product, there is a problem in that it must be combined with the product at the same time and the solidified subrunner (12) must be taken out.
Therefore, in the hot runner system method shown in FIG. 3, the gates (8), (10), (11) and the sub runner (12) are attached to the products shown in FIGS.

However, in this method, the subrunner (12) is manually operated from the molded product (see FIGS. 4 to 6).
Therefore, there is a risk that the molded product is damaged during the operation of removing the sub-runner (12) and becomes a defective product. Furthermore, since the removed subrunner (12) becomes industrial waste, it is expensive to dispose of and is not good for the environment.
Moreover, since the thickness of the sub runner (12) is larger than that of the product, the product cannot be taken out unless the cooling of the sub runner (12) is completed, and it takes a long cooling time to shorten the molding cycle time. There is also a problem that it is not possible.
JP-A-10-138298 JP 11-42683 A JP 2000-271980 A JP2007-83661

The present invention has been made to solve the above-described problems, and in the hot runner system method of filling from the side of the cavity, the generation of extra subrunners other than products is suppressed, and the cooling process is shortened. It aims at providing the hot runner system system which suppresses generation | occurrence | production of the damage | wound in a molded article while aiming.
It is another object of the present invention to stably perform gate cutting and reduce pressure loss during filling with molten resin.

In order to solve the above problems, the present invention employs the following configuration.
(1) In a valve gate type hot runner system, a side having a resin flow passage in which a molten resin is injected from the resin flow passage into the cavity and having a heater on the side surface of the cavity. The side valve gate type hot runner system is characterized in that a nozzle is arranged adjacently and molten resin can be injected into the cavity from the side surface side of the cavity.
(2) After injecting the molten resin into the cavity, the structure is such that the tip of the valve pin is pushed into the gate hole for injecting the molten resin of the side nozzle into the cavity, and the product in the molded product between the side nozzle and the cavity The side valve gate type hot runner system according to the above (1), wherein a gap portion that causes a gate residue or burrs is sealed.

(3) The side valve gate type hot runner system according to the above (1) or (2), wherein the submarine gate system can be molded without the occurrence of burrs by installing the valve pin.
(4) The side valve gate type hot runner system according to any one of the above (1) to (3), wherein in the round gate method, the valve pin can be formed without forming burrs. It is.

According to the present invention, since the extra product such as the sub-runner is not attached to the taken out product, it is not necessary to manually remove the extra sub-runner other than the product, and the work efficiency can be improved.
In addition, there is an effect that the unnecessary time and labor for discarding the unnecessary sub-runners are eliminated, and the cooling time is shortened so that the molding cycle time can be shortened.

Further, since the valve pin securely closes the gate hole, the thread drawing is suppressed and a stable gate cut is obtained.
Moreover, since the valve pin reliably closes the gate hole, the diameter of the gate hole can be set large. Therefore, the pressure loss at the time of filling the molten resin can be reduced, the molten resin can be filled smoothly into the cavity, and the occurrence of shape defects such as sink marks and warpage of the product can be prevented, The injection rate is also increased and the number of gates can be reduced.

Hereinafter, an example of an embodiment of a side valve gate type hot runner system according to the present invention will be described with reference to the drawings. The following side valve gate type hot runner system shows an example of the present invention and does not limit the present invention.
FIG. 1 is a sectional conceptual view showing an example of a side valve gate type hot runner system according to the present invention.

As shown in FIG. 1, immediately before the molding machine (5) injects the molten resin in this embodiment, the piston (6) of the cylinder installed on the side surface of the fixed side mold plate is operated to move the valve pin (7), and the gate After opening the gate hole in the chip (21) and filling the cavity with molten resin, the piston (6) of the cylinder is operated to move the valve pin (7), and the gate hole in the gate chip (21) is closed. After cooling and solidifying the product, the PL surface of the mold is opened and the product is taken out.
Since the gate hole (27) in the gate tip (21) is gate-cut by the piston (6) of the cylinder, no extra runner or sprue other than the product is added to the product. Therefore, the process of removing the extra runners and sprues and the cooling process of the runners and sprues are unnecessary, and the molding cycle time can be shortened.
In addition, there is an effect that the yarn cutting or the like in the product can be prevented by the gate cut.

In the side valve gate type hot runner system according to the present embodiment, the molten resin injected from the molding machine (5) passes through the sprue bush (1), and the manifold block (2), nozzle (3), side nozzle ( After 4), the cavity is directly filled and a product is manufactured by injection molding.
The hot runner system and mold according to the present embodiment include a fixed-side mounting plate (101), a spacer block (102), a fixed-side template (103), a movable-side template (104), a receiving plate (105), and a spacer. It comprises a block (106), an upper ejector plate (107), a lower ejector plate (108), and a movable side mounting plate (109).
With respect to the side valve gate type hot runner system according to the present embodiment, the configuration of the manifold block (2) shown in FIG. 1 will be described in more detail with reference to FIG.

As shown in FIG. 7, the manifold block (2) includes a sprue bush (1), a runner stopper (13), a screw plug (14), a cartridge heater (not shown), a thermocouple (not shown), and a positioning riser (15). The pressure receiving riser (16) is used.
A cartridge heater (not shown) and a thermocouple (not shown) are connected to a temperature controller (not shown), and the manifold block (2) is heated to an optimum molding temperature by electric power supplied via the temperature controller.
Further, a flow path of the molten resin is formed inside the manifold block (2) as shown in FIG. 7, and the number of gate points corresponds to the position of the flow path of the molten resin of the nozzle (3) (see FIG. 1). The outlet of the molten resin is set.

Next, the configuration of the nozzle (3) and the side nozzle (4) shown in FIG. 1 will be described in more detail with reference to FIG. 8 regarding the side valve gate type hot runner system according to the present invention.
As shown in FIG. 8, the nozzle is composed of a nozzle body (3) and a coiled or cast-in heater (17) containing a thermocouple. A coiled or cast-in heater (17) with a built-in thermocouple is connected to a temperature controller (not shown), and raises the temperature of the nozzle body (3) to the optimum molding temperature by electric power supplied via the temperature controller.
Further, since the flow path of the molten resin is formed inside, the nozzle body (3) has a role of flowing the molten resin that has come out of the manifold block (2) into the side nozzle (4).

The side nozzle (4) includes a side nozzle body (4), a cartridge heater (not shown), a thermocouple (not shown), a positioning riser (18), a pressure riser (19, 19), a pin bushing (20), a gate It consists of a chip (21). A gate hole (27) is formed in the gate chip (21).
A heater (not shown) and a thermocouple (not shown) are connected to a temperature controller (not shown), and the side nozzle body (4) is heated to an optimum molding temperature by electric power supplied via the temperature controller.
Further, a flow path of molten resin is formed inside, and the valp pin (7) passes through the resin flow path. The pin bushing (20) is installed to pass the valve pin (7) through the side nozzle (4), and has a role of preventing resin leakage from the gap between the side nozzle (4) and the valve pin (7).

The gate chip (21) is screwed to the side nozzle body (4), and also has a role of transmitting the heat of the side nozzle heated by the heater to the vicinity of the gate hole. Further, the gate chip (21) is fitted to the fixed side template, and determines the position of the side nozzle (4) and has a role of preventing the molten resin injected from the side nozzle (4) from leaking.
Moreover, the cylinder is installed in the side surface of the stationary side template (103) (refer FIG. 1).

FIG. 9 is a cross-sectional view showing the configuration inside the cylinder. As shown in FIG. 9, the piston (6) in the cylinder is closed by air pressure or hydraulic pressure, and operates in a direction perpendicular to the mold opening direction or at an inclination angle. Reference numeral 25 denotes a cylinder upper lid, and reference numeral (26) denotes a cylinder lower lid.
As shown in FIG. 9, a valve pin (7) is fixed to the piston (6) by a retainer (22), and the piston (6) operates in a direction perpendicular to the mold opening direction or at a tilt angle. Then, the valve pin (7) also operates in a direction perpendicular to the mold opening direction or at a tilt angle to open and close the gate hole.
Further, the sprue bush (1), the manifold block (2), the nozzle (3), and the side nozzle (49) are connected to each other, and the respective joint portions are in close contact so that no resin leakage occurs.

Immediately before the molding machine injects the molten resin, air or oil is put into the cylinder, the cylinder piston (6) is operated to move the valve pin (7), and the gate hole at the tip of the gate chip (21) is opened. The molten resin injected by the molding machine reaches the product part through the sprue bush (1), the manifold block (2), the nozzle (3), and the side nozzle (4) in a molten state. After filling, air or oil is put into the cylinder, the cylinder piston (6) is operated, the valve pin (7) is moved, and the gate hole in the gate tip (21) is closed.
The filled molten resin is cooled and solidified and then taken out as a product. Since there are no unnecessary runners and sprues attached, all of the injected resin can be used as a product.

Side gate type hot runner assembly cross section Cross-sectional view of the entire assembly of the side gate mold during the cold runner method Cross-sectional view of the entire assembly of a hot runner using conventional sub-runners Sub-runners and product drawings of side-gate sub-runners molded by the hot runner method using conventional sub-runners Bulk residue and product drawings of submarine gate subrunners molded by the hot runner method using conventional partial subrunners Bulk residue and product drawings of round type gate subrunners molded by the hot runner method using conventional partial subrunners Manifold block and sprue bushing cross section Cross section of nozzle and side nozzle Cross section of cylinder and valve pin

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sprue bush 2 Manifold block 3 Nozzle body 4 Side nozzle 5 Molding machine 6 Piston 7 Valve pin 17 Heater 21 Gate chip 27 Gate hole

Claims (4)

In a valve gate type hot runner system, a side nozzle having a resin flow path with a resin flow path in which a molten resin is injected from the resin flow path into the cavity and a heater installed on the side of the cavity A side valve gate type hot runner system characterized in that molten resin can be injected into the cavity from the side surface side of the cavity. After injecting molten resin into the cavity, it has a structure in which the tip of the valve pin is pushed into a gate hole for injecting the molten resin of the side nozzle into the cavity. The side valve gate type hot runner system according to claim 1, wherein the gap portion is sealed. 3. The side valve gate type hot runner system according to claim 1 or 2, wherein in the submarine gate system, the valve pin can be formed without forming burrs. 4. The side valve gate type hot runner system according to any one of claims 1 to 3, wherein in the round gate system, the valve pin can be formed without forming burrs.

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