JP2591980Y2 - Injection mold - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection mold provided with a valve for opening and closing a gate communicating with a cavity.

[0002]

2. Description of the Related Art Injection molding in which a plurality of cavities are provided in one molding die, molten resin injected from a molten resin injection port is distributed, and the molten resin is guided to a nozzle communicating with the cavities in a warm state. For example, Japanese Unexamined Patent Publication No.
-95923 and JP-A-60-143922.

[0003] These injection molding dies are configured so that a plurality of molded products can be molded simultaneously by one injection molding. Basically, one sprue portion provided at the center portion has one molten metal. It has a resin injection port and a plurality of branched communication holes communicating with the resin injection port.

On the other hand, a plurality of cavities are provided in the mold body, and a plurality of hot nozzle portions having nozzles communicating with these cavities are provided. Further, a manifold having a heater is connected to communicate the flow hole of the sprue with the resin passage of each of the hot nozzles, so that the injected molten resin is guided to the hot nozzle in a warm state. It is configured.

A valve for opening and closing the gate is inserted through the resin passage of the hot nozzle. The valve is vertically slidable by a valve operating piston provided on the upper part of the mold body, and is guided and supported by a valve guide bush provided on the manifold portion.

Therefore, the molten resin injected from the molten resin injection port is distributed to the plurality of manifolds through the flow holes, and is guided from these manifolds to the resin passages of the plurality of hot nozzles.

In this state, when the valve of the hot nozzle is driven upward by the valve operating piston, the gate at the tip of the hot nozzle is opened, and the molten resin is injected into each cavity.

[0008]

However, in the above-described injection mold, the valve is configured to be inserted into the resin passage of the hot nozzle portion and slide in the direction of moving forward and backward with respect to the gate. Have been. Therefore, there is a slight gap between the outer peripheral surface of the valve and the inner peripheral surface of the valve guide bush.

Therefore, there is a problem that the molten resin flowing through the resin passage of the manifold portion flows into the gap and leaks outside through the gap. This invention was made in view of the above circumstances, and its purpose is to:
An object of the present invention is to provide an injection molding die capable of preventing molten resin from leaking from a gap between a valve and a valve guide bush.

[0010]

In order to achieve the above object, the injection molding die of the present invention is characterized in that a mold body having a cavity is provided, and a molten resin injection port is provided in the mold body. And a sprue portion having a flow hole communicating therewith is provided, a hot nozzle portion having a resin passage communicating with the cavity is provided in the mold body, one end is connected to the sprue portion, and the other end is connected to the hot nozzle portion. A hot runner manifold portion that is connected and guides the injected molten resin to the hot nozzle portion in a warm state; a valve that is inserted into a resin passage of the hot nozzle portion and moves forward and backward with respect to a gate; and the hot runner manifold portion is provided. Provided with a valve guide bush that slidably supports the valve in a direction to advance and retreat with respect to the gate, one end of which is embedded in the valve guide bush; The heat conductive member is provided so as to protrude, and in that the protruding portion of the heat-conducting member is cooled by the cooling medium which is configured by providing a cooling means for cooling the valve guide bush.

A second aspect of the present invention is that a plurality of fins are integrally provided at one end of the valve guide bush, and the fins are cooled by a cooling medium, and cooling means for cooling the valve guide bush is provided.

[0012]

According to the injection molding die of the first aspect, by cooling one end of the heat conductive member protruding from the valve guide bush with the cooling medium, cold heat is transmitted to the other end of the heat conductive member and the valve guide bush is cooled. Is cooled. When the valve guide bush is cooled, the molten resin in the flowing state, which has entered the gap between the valve and the valve guide bush, is cooled and solidified, and functions as a sealing material to prevent the molten resin from leaking out of the mold. To prevent.

According to the second aspect of the present invention, the valve guide bush is cooled by cooling the fins of the valve guide bush with the cooling medium. When the valve guide bush is cooled, the molten resin in the flowing state, which has entered the gap between the valve and the valve guide bush, is cooled and solidified, and functions as a sealing material to prevent the molten resin from leaking out of the mold. To prevent.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment, in which 1 is a mold body, which is composed of a fixed mold 2 and a movable mold 3, and a cavity 4 is provided between both molds 2, 3. Is formed.

The fixed mold 2 has a base plate 10 on the upper part. A support plate 11 forming a space a is joined to a lower surface of the base plate 10. A resin passage 1 through which the molten resin flows is provided in the space a.
Hot runner manifold 1 having cylindrical shape 2
3 are provided. The hot runner manifold unit 13 is provided with a heater (not shown).

The hot runner manifold section 13 is integrally formed with a cylindrical sprue section 14 extending upward. A flow hole 15 for molten resin is provided in the center axis direction of the sprue portion 14, and the resin passage 12 of the hot runner manifold portion 13 and the sprue portion 14 are formed.
And the communication holes 15 are communicated with each other. The sprue section 14
Are provided so as to partially protrude from the base plate 10. A flow hole 15 is provided on the upper surface of the sprue portion 14.
Is provided. A nozzle (not shown) of an injection molding machine is provided at the molten resin injection port 16.
Is abutted.

The hot runner manifold section 13 is provided with a fitting hole 12a perpendicular to the resin passage 12 and communicating with the terminal section. This fitting hole 12a is opened on the upper surface of the hot runner manifold section 13,
It communicates with the space a.

The fitting hole 12a has a flange 20a at the upper end.
The flange 20 a is sandwiched between the base plate 10 and the hot runner manifold 13.

At the lower end of the valve guide bush 20, a resin communication passage 20b bent at a right angle is formed. Resin communication passage 2 opening on the side of valve guide bush 20
One end of Ob communicates with the resin passage 12, and the other end of the resin communication passage 20b opening at the bottom communicates with the resin passage 12b formed at the bottom of the fitting hole 12a.

The support plate 11 opposed to the resin passage 12b is provided with a hot nozzle portion 26 extending through the back plate 24 to the cavity plate 25.
b, and a resin passage 26a whose lower end communicates with the cavity 4 via the gate 27 is provided.

A valve guide hole 21 is formed in the axis of the valve guide bush 20.
1, a valve 22 is supported so as to be slidable in the vertical direction. The valve 22 is a straight rod, extends through the resin passage 26a of the hot nozzle 26 to the gate 27, and has a valve 22 for opening and closing the gate 27 at its lower end.
a is formed.

The upper end of the valve 22 is connected to a valve operating piston 23a of an air cylinder 23 provided on the base plate 10 so as to be driven up and down.

At the upper end of the valve guide bush 20, lower ends of a plurality of heat conductive pins 30 as a heat conductive member are buried, and this upper end protrudes upward from a flange 20a of the valve guide bush 20. This heat conduction pin 3
Numeral 0 denotes a rod-like body having excellent thermal conductivity, such as a copper material, which is arranged at regular intervals so as to surround the valve guide hole 21 as shown in FIG.

Further, a cooling pipe 31 is provided on the base plate 10 so as to be orthogonal to the projection 30a of the heat conduction pin 30. A cooling medium such as cold air or cold water as a cooling fluid flows through the cooling pipe 31 to constitute a cooling means for cooling the protruding portion 30 a of the heat conduction pin 30.

Therefore, the valve guide bush 20 is heated by the heat of the hot runner manifold portion 13, but the protrusion 30a of the heat conduction pin 30 is cooled by the cooling medium flowing through the cooling pipe 31, so that the heat conduction pin The lower end portion buried in the valve guide bush 20 is also cooled by conducting the heat through the 30, and the valve guide bush 20 is cooled.

In this state, when the molten resin is injected from the nozzle of the injection molding machine into the molten resin inlet 16, the molten resin is guided to the resin communication passage 20 b via the resin passage 12 of the hot runner manifold 13, Resin passage 2
6a.

When the air cylinder 23 is operated to raise the valve operating piston 23a, the valve 22 is also raised, the valve portion 22a is separated from the gate 27, the gate 27 is opened, and the molten resin inside the resin passage 26a is opened. Is the gate 27
Into the cavity 4 via

When the filling of the predetermined amount of the molten resin is completed, the air cylinder 23 is operated to operate the valve operating piston 23a.
Is lowered, and the valve 22 is also lowered to close the gate 27 by the valve portion 22a.

As described above, when the molten resin flowing through the resin passage 12 of the hot runner manifold portion 13 flows through the resin communication passage 20b during injection molding, a part of the molten resin flows through the valve guide hole 21 and the valve 22. And into the gap. In other words, the molten resin flowing through the resin passages 12 and 26a has a high pressure, so that the molten resin enters even a small gap. However, since the valve guide bush 20 is cooled, the molten resin is cooled and solidified.

As described above, the molten resin is solidified in a state where the molten resin has entered the gap between the valve 22 and the valve guide hole 21 of the valve guide bush 20.
The valve 2 serves as a sealant for sliding parts and also functions as a lubricant with the valve 22.
2 can be operated smoothly, and leakage of the molten resin as in the related art can be prevented.

FIGS. 3 and 4 show a second embodiment. The same components as those in the first embodiment are designated by the same reference numerals and their description is omitted. A valve guide bush 33 having a flange 33a at an upper end is inserted into the fitting hole 12a of the hot runner manifold portion 13, and the flange 33a is sandwiched between the base plate 10 and the hot runner manifold portion 13.

The valve guide bush 33 is made of a material having excellent heat conductivity, and a valve guide hole 34 for supporting the valve 22 so as to be slidable in the axial direction is provided in the shaft portion. Further, a plurality of disk-shaped fins 35 are provided integrally at a predetermined interval above the flange 33a at the upper end of the valve guide bush 33 to form a large surface area.

The fins 35 are connected to the base plate 10
The cooling chamber 36 is housed in a cooling chamber 36 formed of a concave portion provided in the cooling chamber 36. A cooling medium passage 37 communicates with the cooling chamber 36. That is, a cooling medium such as cold air or cold water as a cooling fluid flows through the cooling medium passage 37, and constitutes a cooling unit that cools the fins 35.

The upper end of the valve 22 is connected to a valve driving mechanism 38 provided on the base plate 10 so that the valve 22 is driven to move up and down. That is, a male screw 3 is provided at the upper end of the valve 22.
A connecting ring 39 having 9a is fitted, and an external thread 39a of the connecting ring 39 is screwed to an internal thread 41a of a moving shaft 41 inserted into the guide pipe 40 so as to be movable in the axial direction.

The moving shaft 41 has a columnar shape, and a flat portion 42 is formed at the upper end of the moving shaft 41 by cutting out both side portions. The flat portion 42 penetrates in a direction perpendicular to the axial direction of the moving shaft 41. A through hole 43 is formed. Moving axis 4
A slider 44 which is bent in a substantially U shape and is slidable in a direction orthogonal to the axial direction of the moving shaft 41 is fitted to the flat portion 42 so as to sandwich the flat portion 42.

Opposite inclined slits 45 are formed on both side surfaces of the slider 44. Both ends of a connecting pin 46 inserted into the through hole 43 of the moving shaft 41 are engaged with the inclined slits 45. doing. The connecting pin 46 has a cylindrical portion 46a at the intermediate portion 46, is inserted into the through hole 43 of the moving shaft 41, and has a rectangular column at both ends 46b, and is slidably engaged with the inclined slit 45. Further, a direction conversion mechanism 47 that converts the horizontal linear motion of the slider 44 into a vertical linear motion of the moving shaft 41 via the connecting pin 46 is configured.

The slider 44 is mounted on the base plate 1
0 is housed in a slide guide groove 48 provided in
One end of the slider 44 is connected to an air cylinder 49 for driving the slider 44.

Next, the operation of the molding die configured as described above will be described. When the heated molten resin is injected from the nozzle of the injection molding machine into the molten resin injection port 16, the molten resin is guided to the resin communication passage 20 b via the resin passage 12 of the hot runner manifold 13,
6a.

Then, when the air cylinder 49 is operated to slide the slider 44 in the direction of the arrow x, the inclined surface of the inclined slit 45 is changed to both ends 46b, 46b of the connecting pin 46.
The connection pin 46 is pushed up while sliding. Therefore, the moving shaft 41 connected to the connecting pin 46 rises while being guided by the guide pipe 40, and the valve 22 connected thereto also rises. The valve portion 2 is raised by the valve
2 a is separated from the gate 27, the gate 27 is opened, and the molten resin inside the resin passage 26 a is filled into the cavity 4 via the gate 27.

When the filling of the predetermined amount of the molten resin is completed, when the air cylinder 49 is operated to slide the slider 44 in the direction of the arrow y, both ends 46b of the connecting pin 46 slide on the inclined surface of the inclined slit 45. The connection pin 46 is pushed down while moving. Accordingly, the moving shaft 41 connected to the connecting pin 46 descends while being guided by the guide pipe 40, and the valve 22 connected thereto also descends. When the valve 22 is lowered, the gate 27 is moved by the valve portion 22a.
Close.

As described above, when the molten resin flowing through the resin passage 12 of the hot runner manifold portion 13 flows through the resin communication passage 20b during injection molding, a part of the molten resin flows through the valve guide hole 34 and the valve 22. And into the gap. That is, although the pressure of the molten resin flowing through the resin passages 12 and 26a is high, the molten resin enters even a small gap. However, since the fin 35 is cooled by the cooling medium and the valve guide bush 33 is cooled, the molten resin is cooled. Is cooled and solidified.

As described above, the molten resin is solidified in a state where the molten resin enters the gap between the valve 22 and the valve guide hole 34 of the valve guide bush 33, and the solidified molten resin is removed from the valve 22.
The valve 2 serves as a sealant for sliding parts and also functions as a lubricant with the valve 22.
2 can be operated smoothly, and leakage of the molten resin as in the related art can be prevented.

[0043]

[Effects of the Invention] This invention was constructed as described above.
Since the valve guide bush is cooled, the molten resin leaked from between the valve and the valve guide bush solidifies, and the solidified molten resin acts as a sealing material, so that the molten resin may leak out of the mold. Disappears. further,
The solidified molten resin functions as a lubricant for the valve, and has an effect that the valve can be smoothly operated.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an injection mold according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a longitudinal sectional view of an injection mold according to a second embodiment of the present invention.

FIG. 4 is an exploded perspective view showing the direction changing mechanism of the embodiment.

[Description of Signs] 1 ... mold body, 4 ... cavity, 12, 26a ... resin passage, 13 ... hot runner manifold section, 16 ... molten resin injection port, 20, 33 ... valve guide bush, 22 ...
Valve, 26 hot nozzle, 27 gate, 30
Heat conducting pins (heat conducting members), 35 ... fins.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 45/26-45/44 B29C 45/73

Claims (2)

(57) [Scope of request for utility model registration] 1. A mold body having a cavity, a sprue portion provided in the mold body and having a molten resin inlet and a communication hole communicating therewith, and a resin passage provided in the mold body and communicating with the cavity. A hot runner manifold portion having one end connected to the sprue portion, the other end connected to the hot nozzle portion, and guiding the injected molten resin to the hot nozzle portion in a hot state; and the hot nozzle And a valve guide bush that is provided in the hot runner manifold and is provided in the hot runner manifold to slidably support the valve in the direction to advance and retreat with respect to the gate. In the injection mold, one end is embedded in the valve guide bush, and a heat conductive member is provided with the other end protruding. Injection mold, characterized in that a cooling means for cooling the valve guide bush is cooled by the projecting portion cooling medium guide member. 2. A mold body having a cavity, a sprue portion provided in the mold body and having a molten resin inlet and a communication hole communicating therewith, and a resin passage provided in the mold body and communicating with the cavity. A hot runner manifold portion having one end connected to the sprue portion, the other end connected to the hot nozzle portion, and guiding the injected molten resin to the hot nozzle portion in a hot state; and the hot nozzle And a valve guide bush that is provided in the hot runner manifold and is provided in the hot runner manifold to slidably support the valve in the direction to advance and retreat with respect to the gate. In the injection molding die, a plurality of fins are integrally provided at one end of the valve guide bush, and the fins are formed by a cooling medium. Cooled, injection mold, characterized in that a cooling means for cooling the valve guide bush.