KR20100003595U - Coupling structure of valve pin operation part of hot runner valve gate device using electromagnet - Google Patents

Abstract

The present invention induces the opening and closing of the valve pin by using an electromagnet and the hot runner valve to ensure the operation accuracy and stability of the valve pin by preventing the center of the valve pin from moving even if thermal expansion of the manifold block occurs. In order to provide a valve pin operation part coupling structure of the gate device, a specific means of the present invention, in the hot runner valve gate device for opening and closing the hot runner of the molten resin injected into the mold, the hot providing the passage of the molten resin A manifold block having a runner; A nozzle provided at the manifold block side and having a resin inlet port and a resin inlet port communicating with the hot runner; A valve pin inserted into the nozzle to open and close the resin inlet; A permanent magnet mounted to the upper end of the valve pin; An electromagnet installed on an upper plate fixedly mounted above the manifold block, the electromagnet configured to adsorb / repel the permanent magnet according to an application direction of the current to open and close the valve pin; The manifold block in which the valve pin is inserted is formed with a thermal expansion preventing hole having a diameter at least larger than the diameter of the valve pin to prevent the center movement of the valve pin by thermal expansion.

Injection Mold, Nozzle, Valve Pin, Hot Runner, Manifold Block

Description

Valve pin operation assembling structure of hot runner valve gate device using electromagnet}

The present invention relates to a hot runner valve gate device of an injection mold, and in particular, induction of opening and closing of a valve pin using an electromagnet, and thermal expansion of a manifold block does not cause the center of the valve pin to move even when the valve pin is moved. This invention relates to a coupling structure of the valve pin operating portion of the hot runner valve gate device to ensure the operation accuracy and stability of the valve.

In general, an injection machine injects molten resin into an injection mold to obtain a molded product of a desired shape (eg, a vehicle instrument panel, a door side panel, etc.). At this time, the hot runner through which the resin flows is provided with a valve gate opening and closing device for determining the injection and blocking of the resin. The valve gate opening and closing device is opened at the same time or sequentially according to the control method to determine the injection timing of the molten resin.

In the conventional hot runner valve gate opening and closing device, the hot melt resin injected from the injection machine is distributed through the manifold block to be supplied to the nozzle, and the valve pin located in the nozzle is operated by a hydraulic / pneumatic cylinder device to inject the nozzle. To open and close the

In this case, gun drilling is required on the manifold block to form a hydraulic pneumatic line connected to the hydraulic / pneumatic cylinder, which delays the overall delivery time of the mold and increases the manufacturing cost.

In addition, a hydraulic pump is required, and the cylinder structure is complicated, which causes a problem of inconvenient repair.

In addition, there is no free space between the valve pin and the manifold block into which the valve pin is inserted. When the manifold block is heated by the molten resin and the heater, the valve pin expands to move the center of the valve pin. Not only does it interfere with smooth and accurate opening and closing operation, but the valve pin is bent, which causes a problem of malfunction. This is more severe as the distance between the nozzle inlet and the hot runner on the manifold block side becomes longer. Therefore, the installation distance between the nozzle inlet and the hot runner on the manifold block side is limited.

The present invention was devised in view of the above circumstances, and the operation of the valve pins by inducing the opening and closing of the valve pins using electromagnets and preventing the center of the valve pins from moving even if the manifold block thermal expansion occurs. The valve pin actuating structure of the hot runner valve gate device is provided for accuracy and stability.

Specific means of the present invention for achieving the above object,

In the hot runner valve gate device for opening and closing the hot runner of the molten resin injected into the mold,

A manifold block having a hot runner for providing a passage of molten resin;

A nozzle provided at the manifold block side and having a resin inlet port and a resin inlet port communicating with the hot runner;

A valve pin inserted into the nozzle to open and close the resin inlet;

A permanent magnet mounted to the upper end of the valve pin;

An electromagnet installed on an upper plate fixedly mounted above the manifold block, the electromagnet configured to adsorb / repel the permanent magnet according to an application direction of the current to open and close the valve pin;

The manifold block in which the valve pin is inserted is formed with a thermal expansion preventing hole having a diameter at least larger than the diameter of the valve pin to prevent the center movement of the valve pin by thermal expansion.

Also according to the present invention,

The heat expansion preventing hole is further characterized in that the gas exhaust hole for discharging the resin gas is formed in the manifold block.

According to the coupling structure of the valve pin operation part of the hot runner valve gate device using the electromagnet of the present invention, the center of the valve pin moves even when the expansion of the manifold block occurs while inducing the opening and closing of the valve pin using the electromagnet. This prevents the operation pin and accuracy of the valve pin.

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

As illustrated in FIGS. 1 to 4, a manifold block 10 having a hot runner 11 is provided. At this time, the hot runner 11 provides a passage through which the hot molten resin emitted from the injection machine flows into the injection mold.

The manifold block 10 is provided with a nozzle 20 having a resin inlet 21 communicating with the hot runner 11 at one end and a resin inlet 22 at the other end.

The nozzle 20 is provided with a valve pin 30 for opening and closing the resin inlet 22. The valve pin 30 is positioned in the nozzle 20, and an upper end thereof is inserted into the manifold block 10 so that the upper plate 1 is closed. It is located slightly inward from the bottom surface of the).

The permanent magnet 40 is mounted on the upper end of the valve pin 30 as shown in FIGS. 3 and 4. At this time, the permanent magnet 40 is seated inside the magnet adapter 44 screwed to the valve pin adapter 42 inserted into the upper end of the valve pin 30.

Preferably between the permanent magnet 40 and the upper surface of the upper head portion (30a) of the valve pin 30 by interposing a plurality of buffer plates 43 of SUS material to prevent shock and heat transfer. . A buffer plate 45 made of SUS material may be provided between the valve pin adapter 44 and the head portion 30a of the valve pin 30 in a ring shape.

Electromagnet provided above the manifold block 10 to the upper plate 1 to provide the movement direction and the kinetic force for opening and closing the valve pin 30 by adsorbing or repelling the permanent magnet 40 in accordance with the direction of application of current. 50 is provided.

The electromagnet 50 is composed of a coil for sending a current to form a magnetic field, and iron pieces surrounding the coil or wound around the coil to induce a magnetic force. Therefore, the electromagnet 50 generates the N pole or the S pole in the center portion in accordance with the direction of the current applied to the coil. At this time, the force of the electromagnet 50 may be adjusted according to the number of turns of the coil and the strength of the current. Preferably, the force of the electromagnet 50 may be set to be larger than twice the force obtained by multiplying the cross-sectional area of the nozzle inlet 22 by the injection pressure.

The electromagnet 50 is assembled and fixed to the top plate 1 by an electromagnet cover 2 mounted on the top plate 1 side with a plurality of bolts. Therefore, by loosening the bolt to remove the electromagnet cover 2, it is possible to simply perform the disassembly for repair of the electromagnet 50.

On the other hand, it is preferable that the upper stopper 46 made of rubber or urethane is installed on the upper end of the magnet adapter 44 to mitigate the impact when the valve pin 30 is completed in the ascending operation.

In addition, the manifold block 10 is provided with a spacer ring 60 having an inner cylinder 61 for adjusting the operating stroke S of the valve pin 30, and an inner cylinder 61 of the spacer ring 60. The upper surface is provided with a lower stopper 64 made of rubber or urethane to mitigate the impact when the lowering operation of the valve pin 30 is completed.

Therefore, if the height H of the inner cylinder portion 61 is increased, the stroke S of the valve pin 30 is shortened, and if the height H of the inner cylinder portion 61 is decreased, the stroke S of the valve pin 30 is reduced. ) Lengthens.

Wherein the upper stopper 46 and the lower stopper 64 is configured as a short cylindrical shape is not necessarily limited to this form.

On the other hand, the manifold block 10 in which the valve pin 30 is inserted, the diameter (D) of at least larger than the diameter (d) of the valve pin 30 in order to prevent the center movement of the valve pin 30 due to thermal expansion The heat expansion prevention hole 12 which has () is formed.

That is, the thermal expansion prevention hole 12 is sufficient between the thermal expansion prevention hole 12 and the valve pin 30 even if the manifold block 10 is thermally expanded in consideration of the maximum thermal expansion rate of the manifold block 10. The diameter D is determined so that the clearance gap G occurs (see FIG. 6).

As shown in FIG. 3, a gas exhaust hole 13 for discharging the resin gas rising from the nozzle 20 side is further communicated with the thermal expansion preventing hole 12 to form the manifold block 10. The gas exhaust hole 13 is formed in a direction perpendicular to the passage of the thermal expansion prevention hole 12.

On the other hand, the valve pin 30 is mounted to the nozzle 20, as shown in Figs. 6 and 7, the bushing 70 for preventing the resin gas and the resin leakage is inserted to be movable. At this time, the bushing 70 has circular sliding contact parts 70a and 70b at two positions for reducing sliding friction with the valve pin 30 and operating stability of the valve pin 30. Bushing 70 may be made of brass, for example metal.

In addition, the outer diameter of the bushing 70 located on the manifold block 10 side is configured to be sufficiently smaller than the inner diameter of the thermal expansion prevention hole 12.

At this time, the bushing 70 is preferably a vortex preventing taper 72 is formed toward the resin inlet 22 to prevent the flow of the resin flow into the nozzle 20.

Here, the vortex preventing taper 72 may have a slope 72a or a single or multiple surface treatment in the form of a round 72b with respect to the resin passage on the nozzle 20 side surrounding the valve pin 30.

At this time, the bushing 70 is interposed between the manifold block 10 and the intermediate plate 3 and coupled to the bushing fixing plate 80 mounted on the nozzle 20 as a pin 82. At this time, both surfaces of the bushing fixing plate 80 is polished, and at the same time, an O-ring 84 is installed at a portion to which the hot runner is connected to prevent resin leakage as shown in FIG. 3.

Reference numeral '100' is a 'hot wire'.

The operation of this embodiment configured as described above will be described.

<Advanced valve pin (gate closed)>

In FIG. 3, when the current direction is energized to the coil of the electromagnet 50 by + and-, an N pole is generated at its central portion, and the magnetic force of the N pole of the electromagnet 50 is the N pole of the permanent magnet 40. And the repulsion, this is because the valve pin 30 is connected to the permanent magnet 50 is advanced in the downward direction. At this time, after the downward movement of the valve pin 30, the stop occurs by the lower stopper 64, and at the same time, the stop shock at the stop is alleviated.

Therefore, the valve pin 30 moves forward by the stroke S to close the resin inlet 22 of the nozzle 20 to close the gate, thereby completely preventing further resin from flowing into the mold.

At this time, adjustment of the stroke S is performed by determining the cross-sectional height H of the inner ring portion 61 of the spacer ring 60. That is, the stroke S is shortened when the cross-sectional height H of the inner cylinder part 61 becomes large, and the stroke S increases when its cross-sectional height H becomes small.

<Reverse of valve pin (gate open)>

When the current in the opposite direction flows to the coil of the electromagnet 50 in order to open the gate, the S pole is generated at its central portion, and the magnetic force of the S pole of the electromagnet 50 is permanent. The N pole magnetic force and the attraction force of 40) are generated. As a result, the valve pin 30 to which the permanent magnet 50 is connected retreats upward. At this time, the stop occurs after the upward movement of the valve pin 30 by the upper stopper 46 of the magnet adapter 44, and the stopping shock at the time of stopping is alleviated.

Therefore, the valve pin 30 moves backward by the stroke S to open the resin inlet 22 of the nozzle 20 to open the gate, thereby allowing the resin to flow into the mold and to be injected.

As such, the present invention merely controls the current flow direction of the electromagnet 50 so that the movement and the direction of the valve pin 30 are selected to easily control the opening and closing of the resin inlet 22. Therefore, it is not necessary to configure various hydraulic pneumatic lines in order to use the hydraulic and pneumatic cylinders as in the prior art, and the entire production delivery time is shortened, and the manufacturing cost can be reduced by eliminating the need for gun drilling. In addition, when the electromagnet 50 has an abnormality, the electromagnet 50 can be easily separated after removing the electromagnet cover 2, thereby simplifying after-sales service (A / S).

On the other hand, the manifold block 10, which provides a supply passage for the molten resin of high temperature, has a clearance between the valve pin 30 and the thermal expansion prevention hole 12 even when the thermal expansion occurs and the center of the thermal expansion prevention hole 12 moves. There is no center movement of the valve pin 30 by this. As a result, the valve pin 30 is not bent and the occurrence of deformation is precisely and smoothly opening and closing operation.

In addition, since the gas flowing into the thermal expansion preventing hole 12 through the nozzle 20 is discharged through the gas exhaust hole 13, there is no adverse effect on the permanent magnet 40 and the electromagnet 50.

On the other hand, the molten resin flowing from the hot runner 11 of the manifold block 10 to the nozzle 20 has a laminar flow due to the vortex preventing taper 72 of the bushing 70 at the portion in contact with the valve pin 30. It is induced and the vortex is suppressed. Therefore, even if the color of the injection resin is changed, the color before the change is not affected and the color quality of the injection product is improved.

In addition, the nozzle 20 is provided with a bushing 70 for guiding the movement of the valve pin 30, and the valve pin 30 is operated by sliding contacts 70a and 70b formed on the inner surface of the bushing 70. Stability is improved.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto, and the technical idea and the following of the present invention are provided by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

The following drawings, which are attached in this specification, illustrate the preferred embodiments of the present invention, and together with the detailed description of the present invention, which serves to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings. It should not be construed as limited to.

1 is a block diagram of a hot runner valve gate device using an electromagnet according to the present invention.

FIG. 2 is a sectional view seen from a line A-A in FIG. 1; FIG.

3 is an enlarged view illustrating main parts of FIG. 1;

Figure 4 is a block diagram of the coupling structure of the upper valve pin applied to the hot runner valve gate device using an electromagnet according to the present invention.

Figure 5 is an exploded perspective view of the valve pin adapter, permanent magnet and magnetic adapter applied to the present invention.

Figure 6 is a coupling structure of the bushing applied to the present invention.

7 is a perspective view of a bushing applied to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: manifold block

13: gas exhauster

20: nozzle

30: valve pin

40: permanent magnet

42: valve pin adapter

44: magnetic adapter

46: upper stopper

50: electromagnet

60: spacer ring

64: lower stopper

70: bushing

72: vortex prevention taper

Claims (2)

In the hot runner valve gate device for opening and closing the hot runner of the molten resin injected into the mold, A manifold block 10 having a hot runner 11 for providing a passage of molten resin; A nozzle 20 installed at the side of the manifold block 10 and having a resin inlet 21 and a resin inlet 22 communicating with the hot runner 11; A valve pin (30) inserted into the nozzle (20) to open and close the resin inlet (22); A permanent magnet 40 mounted to an upper end of the valve pin 30; An electromagnet 50 installed on the upper plate 1 fixedly mounted above the manifold block 10 to adsorb / repel the permanent magnet 40 in accordance with the direction of application of current, thereby opening and closing the valve pin 30. )and; The manifold block 10 into which the valve pin 30 is inserted has a diameter D of at least larger than the diameter d of the valve pin 30 in order to prevent center movement of the valve pin 30 by thermal expansion. Coupling structure of the valve pin operating portion of the hot runner valve gate device using an electromagnet, characterized in that the thermal expansion prevention hole 12 having. The method of claim 1, The valve pin of the hot runner valve gate device using an electromagnet, characterized in that the gas expansion hole 13 for discharging the resin gas is further communicated with the thermal expansion preventing hole 12 and formed in the manifold block 10. Actuator coupling structure.

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