KR101290549B1 - Hotrunner system - Google Patents

Abstract

The present invention discloses a hot runner valve apparatus for an injection molding machine.
The hot runner valve device for an injection molding machine of the present invention is a hot runner for an injection molding machine having a manifold formed of a resin furnace and a nozzle connected to one side thereof to receive resin and guide the resin to the cavity side of the mold. In the valve device, the nozzle has a body through which the installation hole is formed through the center and the entrance hole having a reduced diameter with respect to the installation hole in the lower side, the nozzle is provided by the slide fitting so as to be elevated in the installation hole The body is lowered by the supply pressure of the resin and ascended by the return means, and a resin flow path receiving the resin is formed at the center, and a body having a flow resistance portion having a reduced diameter to resist the pressure of the supplied resin, and a lower end of the body. It is provided with a reduced diameter at the inside of the nozzle during the upward movement and the upward movement during the downward movement And out through the hole in contact with the mold, and the inside is configured to include the lift pins having a flow control tip to the take-out is in communication with the resin conduit.
The hot runner valve device for an injection molding machine according to the present invention having such a configuration integrates the lifting operation for the lifting pin by combining the supply working pressure of the resin supplied into the nozzle and the return element, and the lifting pin is lifted at the end. By being located in the additional nozzle or in contact with the mold, there is an advantage that the supply of the resin injected into the cavity of the mold can be easily interrupted using the phenomenon that the resin therein solidifies and melts.

Description

Hotrunner system for injection molding machine

The present invention relates to a hot runner valve device for an injection molding machine for injecting molten resin into a cavity of a mold, and more particularly, resin flows inside by using an operating pressure and a return means of the resin supplied through a manifold. By raising and lowering the lifting pin, it is possible to easily control the supply of resin injected into the cavity of the mold, so that molding conditions for small parts or resins with poor fluidity can be formed well, and the productivity is improved, It relates to a hot runner valve device for an injection molding machine that can reduce the occurrence.

Generally, an injection molding machine for molding a plastic product injects a resin material into a manifold from a mold cylinder in which a resin is melted. The injected resin is uniformly distributed along a resin flow path branched in the manifold, And is injected into a molding space, that is, a cavity, formed by the upper and lower cores, which are supplied by one or more nozzles, respectively, as a product molding frame.

Such an injection molding machine is configured to open and close a gate or an outlet by an elevating operation of a valve pin. When a relatively large number of molds are formed at a time according to the quantity of a molded product, a manifold type that supplies resin through the manifold is used , And a single type is used when producing a single product.

1 is a cross-sectional view schematically showing a hot runner system for an injection molding machine in which a valve pin is raised and lowered using a high-pressure air according to the prior art.

As shown in the figure, the valve apparatus of the injection molding machine for the multi-cavity mold comprises a driving unit 100 and a valve unit 200, and high-pressure air is used as a driving source for moving the valve pin 210 up and down. That is, the driving unit 100 includes a plurality of air channels 110 and 120, which are channels for supplying and discharging high-pressure air from the outside, and a plurality of air channels 110 and 120, And the piston 140 in the cylinder 130 moves up and down by the inflowing high-pressure air. At this time, a valve pin 210 is connected to a lower end of the piston 130 to be interlocked.

The valve pin 210 is structured to selectively open or close a gate or an outlet forming the tip of the nozzle 220 by moving up and down in conjunction with the piston 130.

Meanwhile, the valve device 200 includes a nozzle 220 in which a heater is wound to form a body to prevent solidification of the resin. Inside the nozzle 220, a valve pin 210 extends in a vertical direction So as to be raised and lowered. The resin channel 230 is formed around the valve pin 210 with a predetermined clearance between the outlet of the nozzle 220 and the resin channel 230 of the manifold 300, (Not shown).

When the operating pressure of the high pressure is selectively supplied through the air channels 110 and 120, the piston 140 is lifted or lowered, and at the same time, the valve pin 210 is interlocked So that the lifting operation is performed integrally. Accordingly, as the piston 140 is lifted and lowered, the outlet of the nozzle is opened or blocked. As a result, the resin supplied through the manifold 300 is supplied into or blocked from the mold through the outlet.

In brief, a valve gate (outlet) device for an injection molding machine, which operates the air pressure according to the prior art, supplies high-pressure air selectively into the cylinder 130 through the corresponding air channels 110 and 120 to lift the piston 140 And the valve pin 210 opens and closes the outlet (gate) of the nozzle in conjunction with the piston 140 at this time.

However, since the valve device according to the related art configured as described above uses high pressure air as an operation source for elevating the valve pin, it is necessary to adopt an airtight structure to prevent air leakage and a large pneumatic device for supplying the working pressure. As it requires a compressor, the structure is complicated by its volume, which is not only limited to the installation space but also has a disadvantage of extremely poor maintenance and management.

In addition, when applied to a multi-cavity mold having a plurality of nozzles, due to the dimensional dispersion of each nozzle, the injection amount of each nozzle occurs as a result, there was a problem that it is difficult to mass-produce a molded article having a uniform quality.

In order to solve such a problem, the applicant has applied for utility model registration No. 2002-09883 (Registration No. 0280604, registration decision), Utility Model Registration Application No. 2002-09884 (Registration No. 0280605, Registration Maintenance Decision), utility Application for registration of utility model No. 2002-09885 (registration No. 0280606, registration maintenance decision), application for utility model registration No. 2002-19175 (registration No. 0290456, registration maintenance decision), application for utility model registration No. 2003-0034932 (registration) No. 0341515 registration maintenance decision, Utility Model Registration Application No. 2003-0038360 (Registration No. 0344137 registration maintenance decision) has been registered a valve device for operating the valve pin in the vertical direction by the power source.

Looking at the configuration of these valve apparatus roughly, it is composed of a nozzle and a driving means largely, the nozzle is a general valve structure in which a resin flow path for receiving the resin therein is injected into the mold through the outlet provided in the tip portion Take As the driving means, a forward / reverse motor or a solenoid actuator for raising and lowering the valve pin by power supply is used.

As described above, the applicant applies a valve device, which is applied by a power supply, to the size of the overall size of the valve device, which can increase the degree of freedom in the mold design. In addition, the valve pin movement can be controlled quickly and precisely.

However, in the case of using the station / motor as a driving source in various valve devices, the applicant has to have a reduction gear as well as a cooling structure for cooling the motor. .

On the other hand, in the case of the actuator using the solenoid principle, the structure can be relatively simplified, but there is a disadvantage in that smooth driving is not performed at the time when the valve pin moves to the relative position in the open or closed state. This is not just a solenoid actuator. In almost all hot runner systems, the valve pin is fitted to the outlet when the outlet (gate) is shut off and the other end is fitted to the bushing to support linear movement. When the valve pin is raised to open the outlet in such a state, it is possible to overcome the stop resistance applied to the valve pin (the frictional resistance caused by the supporting element such as the bushing supporting the valve pin and the frictional resistance when it is fitted to the outlet). It needs enough power, that is, large power.

That is, in most hot runner systems, a drive source with an output higher than the rated output is applied to overcome the frictional resistance initially acted upon moving to the relative position in the raised or lowered state of the valve pin and to allow the lowering or raising operation to be executed. There is a situation.

Therefore, there is not only a closed end that increases the manufacturing cost as a high output drive source (hydraulic / pneumatic cylinder, forward / reverse motor, actuator) is required, but also a mold for forming a compact and precise injection molding as the volume increases. There was a problem that the degree of freedom of application is greatly limited.

In particular, there is a problem that the lifting and lowering of the valve pin is not smooth when molding a small and precise part, or when molding the product by using a resin containing glass fiber or magnesium component having poor fluidity.

In addition, the end of the nozzle is in contact with the mold to lose heat to the mold, when the resin flows to maintain the molten state by the heater wound on the outer surface of the nozzle, but when the resin flow is stopped Due to the heat loss occurring at the end, the resin in this part solidifies, resulting in the injection process having to be suspended until the solidified resin melts again, resulting in reduced productivity and the solidified resin not completely melting. There was a closed end that caused mold failure.

In order to solve this problem, conventionally, a high frequency or low pressure heating means is additionally installed to enable rapid heating of the tip of the nozzle, but due to rapid heating of the tip of the nozzle, it causes damage to the mold which is in contact with the mold. There is a serious problem of shortening.

In addition, as the high-frequency and low-pressure heating means are installed around the nozzle, the overall volume of the valve device is increased, thereby limiting the degree of freedom in design, and it is not applicable to the mold for mass production of compact and precise molded products. There is a problem in that the economy is inferior because of the difficulty of maintenance and additional equipment of expensive high frequency and low pressure equipment.

The present invention was created to solve the problems of the prior art as described above, an object of the present invention is to make the lifting pin in the nozzle in contact with the mold in conjunction with the supply pressure of the resin when the resin filling the cavity of the mold, After the resin filling is completed, the lifting pin in the holding step automatically blocks the resin flow due to the internal resin solidifying due to the temperature difference with the mold, and then the lifting pin is positioned inside the nozzle by the returning element to solidify by the heater. As a result, the melted resin is melted to maintain the atmospheric state, and as a result, it is easy to supply resin injected into the cavity of the mold by using the solidification and melting of the resin due to the temperature difference between the nozzle and the mold without applying a complicated mechanical shielding structure. Molding for small parts or resins with poor flowability Injection one to the well create a key to increase the quality and mass production of a molded article molding machine to provide a hot runner valve device.

Hot runner valve device for an injection molding machine according to a preferred embodiment of the present invention for realizing the above object is connected to one side of the manifold and the resin formed to form a resin passage to receive the resin to guide the cavity side of the mold In the hot runner valve device for an injection molding machine having a nozzle wound around the heater, the nozzle has a body formed through the installation hole through the center and the entrance hole having a reduced diameter with respect to the installation hole in the lower side It is provided by the slide fitting so as to be elevated in the installation hole is lowered by the supply pressure of the resin and raised by the return means, the resin flow path is formed to receive the resin to the center and the diameter so as to resist the pressure of the supplied resin The body is provided with a reduced flow resistance portion and the lower portion of the body has a reduced diameter to move upward It is characterized in that it comprises a lifting pin having a flow control tip is located inside the nozzle and in contact with the mold through the entrance hole when the lowering movement, the discharge passage formed in communication with the resin flow passage therein. .

As a preferable feature of the present invention, the nozzle is formed on one side of the inner surface is a spring mounting hole is fitted with an elastic spring that is a return means, the lifting pin is provided on one end of the outer circumferential surface of the body elastic spring fitted in the spring mounting hole The upper end of the engaging jaw is formed, the elastic spring is the lower end of the coil spring is in contact with the stepped portion connecting the spring mounting hole and the installation hole.

As another preferable feature of the present invention, the return means is provided by a cylinder housing having an air channel for receiving high pressure air from the outside and is provided by the high pressure air introduced through the air channel provided inside the cylinder housing. Composed of a piston, the lifting pin is formed in the protruding from one end of the body to form a engaging portion in contact with the upper portion of the piston.

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As another preferred feature of the present invention, the body is provided with a heat shield ring made of a material having a lower mold and a lower thermal conductivity.

The hot runner valve device for an injection molding machine according to the present invention combines the lifting operation for the lifting pin by combining the supplying working pressure of the resin supplied into the nozzle and the return element, and the lifting end of the lifting pin is positioned in the nozzle. Or by contacting the mold, there is an advantage that the supply of the resin injected into the cavity of the mold can be easily interrupted by using a phenomenon in which the resin therein solidifies and melts.

Therefore, the molding conditions for resins containing small components or components with poor fluidity can be well established, and the structure of the driving source for driving the lifting pin can be simplified, resulting in product maintenance and handling management. In addition to increasing the convenience of use, the reduction of the volume of the driving element can greatly increase the degree of freedom of application and design of the mold, thus providing a very useful effect in the industry.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to that, terms and words used in the present specification and claims should not be construed in a conventional and dictionary sense, and the inventor may properly define the concept of the term in order to best explain its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

1 is a cross-sectional view of a hot runner valve apparatus for an injection molding machine according to the prior art,
Figure 2 is a cutaway perspective view showing a hot runner valve device for an injection molding machine according to an embodiment of the present invention,
Figure 3 is an exploded perspective view showing a hot runner valve device for an injection molding machine of Figure 2,
4 is a cross-sectional view showing a hot runner valve device for an injection molding machine of FIG.
5 to 8 are cross-sectional views for explaining the operation of FIG.
9 is a perspective view showing a cutaway hot runner valve device for an injection molding machine according to another embodiment of the present invention;
10 is a cross-sectional view showing a hot runner valve device for an injection molding machine of FIG.
11 to 14 are cross-sectional views for explaining the operation of FIG.

Hereinafter, a hot runner valve apparatus for an injection molding machine according to the present invention will be described with reference to the accompanying drawings. First, it should be noted that the same components or parts among the drawings are denoted by the same reference numerals as possible. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Figure 2 is a cutaway perspective view showing a hot runner valve device for an injection molding machine according to an embodiment of the present invention, Figure 3 is an exploded perspective view showing a hot runner valve device for an injection molding machine of Figure 2, Figure 4 is an injection of Figure 2 It is sectional drawing which shows the hot runner valve apparatus for molding machines.

5 to 8 is a cross-sectional view for explaining the operation of Figure 2, Figure 5 shows the lifting pin is moved down by the supply pressure of the resin for filling the resin to the cavity, Figure 6 is a cavity of the mold Is a view showing a state in which the resin is solidified in the flow control tip forming the end of the lifting pin in the state that the filling of the resin is completed and to maintain the holding pressure, Figure 7 is lifted by the elastic force of the elastic spring that is the return element FIG. 8 illustrates a state in which the pin is moved up, and FIG. 8 illustrates a state in which the solidified resin is molten in the flow control tip forming the end of the lift pin.

The configuration of the hot runner valve device for an injection molding machine of the present invention will be described with reference to the drawings.

First, the hot runner valve device 1 for an injection molding machine of the present invention receives a resin from an injection cylinder (not shown) largely, and a manifold 10 having several branched resin furnaces 10a formed therein to branch and supply the resin. And a nozzle 20 connected to one side of the manifold 10 to receive the resin and to inject the resin into the cavity c of the mold m including the upper and lower cores m1 and m2. The elevator 20 which is installed in the nozzle 20 so as to be lifted and lowered by a resin pressure supplied into the nozzle and connected to the gate g which forms the inlet of the cavity c provided in the upper core m1. The pin 30 and the return means for returning the downwardly moved lifting pin 30 to the inside of the nozzle.

The manifold 10 is manufactured in the shape of a plate made of a metal material having excellent thermal conductivity, and is formed in a branched shape of the resin path 10a through which the liquid resin in the molten state is moved. A heater (not shown) is embedded in the upper and lower surfaces of the resin to prevent the resin flowing along the resin passage 10a from being solidified.

Referring to the drawings, the manifold 10 having the above-described configuration may include a driving unit 40 for elevating a nozzle 20 to be described later and an elevating pin 30 provided in the nozzle 20. ) Is provided.

Since the manifold 10 having such a structure is implemented by a known technique, a detailed description thereof will be omitted.

The nozzle 20 has a tubular body 21 having a hollow cylindrical shape, and a heater 23, which is a heating element, is wound around the outer circumferential surface of the body 21. In addition, an installation hole 21 a is formed through the center of the body 21, and an entrance hole 22 having a reduced diameter with respect to the installation hole 21 a is formed through the lower surface thereof.

In addition, the body 21 has a spring mounting hole 21b formed by expanding the diameter of the inner circumferential surface of the middle portion with reference to the drawings, and the spring mounting hole 21b has an elastic spring 40 which is a return element to be described later. Is fitted.

That is, the body 21 forming the body of the nozzle 20 has an upper body 21 'connected to the resin passage 10a of the manifold 10 and a lower side of the upper body 21'. It is connected by screwing and consists of a spring mounting hole 21b and a lower body 21 ″ having an installation hole 21a having a reduced diameter with respect to the spring mounting hole 21b.

In addition, as shown in the drawing, the nozzle 20 may have a heat shield ring w or a gap formed therein to suppress heat conduction with the mold. In the present invention, the lower edge of the body 21 of the nozzle 20 so as to span the mold and the lower surface of the heat shielding ring (w) having a low thermal conductivity between the gap in a state where a predetermined gap with the mold (m) This heat shield ring (w) is a nozzle adjacent to the mold (m) as the resin supply element of the lifting pins 30, including the nozzle 20 maintains a high temperature compared to the mold (m) This is to minimize the heat loss generated in the lower surface of the body 21 of (20). That is, the nozzle 20 is heated to a temperature of about 250 ~ 350 ℃ to maintain the resin in a molten state, but in the case of a mold to maintain a relatively low temperature of 60 ~ 90 ℃ for the molding of the molded article In the present invention, when the lower surface of the nozzle 20 is in direct contact with the mold m, the resin fluidity at the end of the body 21 of the nozzle 20 is deteriorated as a result of a sudden heat loss. As an alternative to alleviate this, a gap is formed between the lower surface of the body 21 of the nozzle 20 and the mold m, and a thermally conductive thermal barrier ring w is provided between the gaps.

On the other hand, although not shown, it may be possible to form a gap between the lower surface of the body 21 and the mold (m) without using the heat shield ring (w).

The nozzle 20 of such a configuration is provided to be capable of elevating in a state in which the elevating pin 30 to be described later slides therein.

The lifting pin 30 is a tubular member whose one end slides into the installation hole 21a of the body 21 constituting the nozzle 20, and as shown in the drawing so that resin can flow therein. It consists of a body 31 in which a resin flow passage 31a, which is a straight flow path, is formed, and a flow control tip 32 provided with a reduced diameter with respect to the body 31.

The body 31 is provided in a straight tubular shape and the locking jaw 35 having a diameter expanded to receive an elastic support force from the elastic spring 40 which is a return means to be described later in the middle portion is formed protruding, the locking at this time Jaw 35 preferably has a diameter enough to be in sliding contact with the inner surface of the spring mounting hole (21b).

The flow control tip 32 is provided with the lifting pins 30 positioned inside the nozzle 20 when the lifting pin 30 moves upward, and when the lifting pins 30 come into contact with the mold when the lifting pins 30 are lowered. That is, the lifting pin 30 is disposed to be connected to the resin passage 10a of the manifold 10 so that the resin is supplied through the resin passage 31a formed inside the body 31, and the flow control is a lower end portion. Tip 32 has a reduced diameter so that the resin supplied through the manifold 10 can be injected into the cavity (c) of the mold (m), but passes through the entrance hole 22 of the body 21 It is provided so that it may have a diameter enough to be connected to the gate g which is the entrance of the cavity c of the metal mold m.

In addition, the lifting pin 30 has a flow resistance portion 31b having a reduced diameter so that the pressure of the supplied resin may gradually increase in forming the resin flow passage 31a in the body 31. . That is, the lifting pin 30 has a resin flow path 31a connected to the manifold 10 at the center thereof, and the flow control tip 32 is reduced while being connected to the flow resistance part 31b. A blowout passage 32sh connected to the resin flow passage 31a while having a diameter is formed therethrough.

The lifting pin 30 having such a configuration generates resistance in the flow resistance portion 31b when resin is supplied to the resin flow passage 31a connected to the resin passage 10a of the manifold 10. Therefore, the lifting pin 30 is lowered and the resin is passed through the extraction path 32sh in a state in which the flow control tip 32, which is the end thereof, is connected to the gate g, which is the entrance of the cavity c of the mold m. Will be filled.

As shown in the figure, the return means is an element for returning the lowered lifting pin 30 to position, and in this embodiment, it is proposed that the elastic spring 40 is used.

The elastic spring 40 is provided to wind the outer circumferential surface of the lifting pin 30 located in the spring mounting hole 21b formed on the inner circumferential surface of the body 21, and the lower end of the elastic spring 40 is wound around the spring mounting hole 21b and the installation hole. (21a) is in contact with the stepped portion (21c) is connected and the upper end is in contact with the lower surface of the locking projection (35) of the lifting pin 30 to act as an elastic support force to move the lifting pin (30) up.

The elastic spring 40 is supported by a spring mounting hole 21b formed in the lower body 21 ″ of the nozzle 20 whose lower end is a fixed body and a stepped portion 21c which is a connecting portion of the installation hole 21a. The upper end of the upper end is supported by the lower surface of the locking step 35 of the lifting pin 30 capable of positional displacement in the vertical direction, thereby exerting a lifting support force on the locking step 35 of the lifting pin 30.

On the other hand, the elastic spring 40 is provided to have a smaller elastic repulsive force to the supply pressure of the resin acting on the lifting pins 30 through the nozzle 20. This is when the resin is supplied to the resin flow path (31a) of the lifting pins 30 through the nozzle 20, the lifting pins 30 performs the lowering operation in conjunction with the supply pressure of the resin, on the contrary the lifting pins (30) This is because the lifting pins 30 must be moved up and down when the resin supply pressure is removed from the resin flow path 31a.

The return means having such a configuration may be applied to various driving sources or structures as long as it has a feature capable of returning the lifting pins 30. For example, a well-known oil-pneumatic cylinder type using oil and pneumatics may be applied, or an electric motor type using a motor previously filed by the applicant may be applied.

Referring to the operation of the hot runner valve device for an injection molding machine according to the present embodiment configured as described above are as follows.

When it is supplied to the resin flow path 31a of the lifting pin 30 installed in the nozzle 20 through the resin passage 10a of the manifold 10 in the state shown in FIG. 4, the said lifting pin 30 As a result of the flow resistance of the resin in the flow resistance portion (31b), as shown in FIG. In this case, the flow control tip 32 forming the lower end of the lifting pin 30 passes through the entrance hole 22 of the nozzle 20 to form a cavity m in the upper core m1 constituting the mold m. Is connected to the gate g, which is an inlet of the inlet, and the resin is injected into the cavity c of the mold m in this state.

Subsequently, when the filling of the resin in the cavity (c) of the mold (m) is completed, a pressure-receiving step is performed. At this time, the resin supply pressure acting on the resin flow path 31a in the lifting pin 30 is removed. In this state, since the flow control tip 32 is in contact with the mold m, a sudden heat loss occurs, and as a result, as shown in FIG. 6, the inside of the discharge path 32sh of the lifting pin 30 is shown. The resin is solidified to form a solid resin r '. That is, when the filling of the resin in the cavity (c) of the mold (m) is completed, the injection pressure does not act on the lifting pin (30) at the same time the flow control tip 32 of the lifting pin (30) is As a result, the resin in the flow control tip 32 forms solidified resin r 'as it loses heat in the absence of fluidity because it is in contact with the nozzle 20 having a relatively low temperature. The solid resin r 'serves to close the take-out path 32sh of the flow control tip 32.

Subsequently, the mold (m) filled with resin in the cavity (c) proceeds to a process for taking out the molded article, and as the holding pressure for molding the molded article is released, the lifting pins 30 are elastic springs 40 as return elements. The upward movement by the elastic support of the to achieve a state as shown in FIG.

Subsequently, the flow control tip 32 of the elevating pin 30 moved into the nozzle 20 has a solid resin r ′ due to the heating of the heater 23 wound on the outer surface of the body 21. As shown in FIG. 8, it is converted into the molten resin r.

On the other hand, the flow control tip 32 in the present invention is not only flows or flows naturally until the injection pressure is applied from the injection cylinder according to the viscosity of the resin is not only 0.4mm ~ several mm but also the viscosity of the resin Keep it.

9 is a cutaway perspective view illustrating a hot runner valve device for an injection molding machine according to another embodiment of the present invention, and FIG. 10 is a cross-sectional view illustrating the hot runner valve device for an injection molding machine of FIG. 9.

11 to 14 are cross-sectional views illustrating the operation of FIG. 9, and FIG. 11 is a view illustrating a state in which a lifting pin is moved downward by a supply pressure of a resin for filling a resin into a cavity, and FIG. 12 is a mold. Fig. 13 is a view showing a state in which the resin in the flow control tip that forms the lift pin end in the state for maintaining the holding pressure after the filling of the resin in the cavity of the cavity is solidified, and FIG. The lift pin is moved up in conjunction with the upward movement of the piston, and FIG. 8 illustrates a state in which the solidified resin is melted inside the flow control tip forming the end of the lift pin.

The hot runner valve device 1 for an injection molding machine in this embodiment is similar to the configuration of the embodiment described above. However, in this embodiment, the pneumatic cylinder 45 is applied without applying the elastic spring as the return element.

That is, the return element in the present embodiment is a pneumatic cylinder 45 for providing a lifting force to the lifting pin 30 which is installed to be liftable inside the body 21 of the nozzle 20 is used, such a pneumatic The cylinder 45 is composed of a cylinder housing 45a which forms an outer body and a piston 45b which is installed inside the cylinder housing 45a and is supplied with a high pressure air and has a positional displacement in the upward direction. do.

In addition, the pneumatic cylinder 45 has a sealed structure and has a cylinder housing 45a having at least one air channel 45 'for supplying and discharging high pressure air from the outside, and the cylinder housing 45a. It is provided in the interior is composed of a piston (45b) is raised by the high-pressure air acting through the air channel (45 ').

On the other hand, the upper surface of the piston (45b) is configured such that the lower surface of the locking portion 35 'extended from one outer peripheral surface of the lifting pin 30 is in contact with the locking portion 35' during the upward movement of the piston (45b) The lifting pins 30 are provided to be linked up with each other. On the other hand, when the lifting pin 30 is lowered, the pneumatic cylinder (45) does not act or a pressure smaller than the supply pressure of the resin acting on the lifting pin (30) should act.

Referring to the operation of the hot runner valve device for an injection molding machine according to the present embodiment configured as described above are as follows.

When it is supplied to the resin flow path 31a of the lifting pin 30 installed inside the nozzle 20 through the resin passage 10a of the manifold 10 in the state shown in FIG. 10, the said lifting pin 30 As a result of the flow resistance of the resin in the flow resistance portion (31b) as a result, as shown in FIG. At this time, the flow control tip 32 forming the lower end of the lifting pin 30 passes through the entrance hole 22 of the nozzle 20 to form a cavity m in the upper core m1 constituting the mold m. It connects to the gate g which is an inlet of, and in this state, resin is injected into the cavity c of the metal mold | die m.

Subsequently, when the filling of the resin in the cavity (c) of the mold (m) is completed, a pressure-receiving step is performed. At this time, the resin supply pressure acting on the resin flow path 31a in the lifting pin 30 is removed. In this state, since the flow control tip 32 is in contact with the mold m, a sudden heat loss occurs, and as a result, as shown in FIG. 12, the inside of the discharge path 32sh of the lifting pin 30 is shown. The resin is solidified to form a solid resin r '.

Subsequently, the mold (m) filled with resin in the cavity (c) of the mold (m) proceeds to a process for taking out the molded article, and as the holding pressure for molding the molded article is released, the lifting pin 30 is a return element. As the high pressure air acts on the air channel 45 'of the pneumatic cylinder 45, the piston 45b having the piston 45b and the catching portion 35' contacted therewith moves upwards, as shown in FIG. State is achieved.

Finally, the flow control tip 32 of the lifting pin 30 moved to the inside of the nozzle 20 is solidified by the heat generated by the heater 23 wound on the outer surface of the body 21. ) Is converted to the molten resin r as shown in FIG.

In this case, the molten resin (r) flows naturally until the injection pressure is applied from the injection cylinder because the diameter of the flow control tip 32 is only 0.3 mm to several mm, and the resin basically has viscosity. It will remain unloaded or not flown.

On the other hand, the present invention is not limited to the described embodiments, it is possible to use and change the application site, it is common in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those who have knowledge. Therefore, such modifications or variations will have to belong to the claims of the present invention.

1 valve device 10 manifold 10a resin
20: nozzle 21: body 22: guide hole
23 heater 30 lift pin 31 body
31a: resin flow path 32: flow control tip 35: locking jaw
40: elastic spring 45: pneumatic cylinder c: cavity
m: mold r: molten resin r ′: solidified resin

Claims (5)

In the hot runner valve device for an injection molding machine comprising a manifold formed of a resin furnace and a nozzle connected to one side thereof to receive the resin and guide the resin to the cavity side of the mold.
The nozzle 20 has a body 21 formed with an installation hole 21a through the center thereof and an entrance hole 22 having a reduced diameter with respect to the installation hole 21a at a lower side thereof.
The mounting hole 21a is provided with a slide fitting so as to be lifted and lowered by the supply pressure of the resin and raised by the returning means, and a resin flow path 31a is formed to receive the resin and the pressure of the resin supplied. It is provided with a reduced diameter at the lower end of the body 31 and the lower body of the body 31 is formed with a flow resistance portion (31b) to reduce the diameter to be located in the inside of the nozzle 20 during the upward movement and during the downward movement A lifting pin 30 having a flow control tip 32 formed therein through the entrance hole 22 to be in contact with the mold m and having a discharge passage 32sh communicating with the resin flow passage 31a therein;
Hot runner valve device for injection molding machine comprising a.
The method of claim 1,
The nozzle 20 is formed with a spring mounting hole (21b) is fitted into the elastic spring 40, which is a return means on one side inner surface,
The lifting pin 30 is provided on the outer peripheral surface of the one end of the body 31 is provided with a locking step (35) for supporting the upper end of the elastic spring 40 fitted in the spring mounting hole (21b),
The elastic spring 40 is a hot spring runner valve device for the injection molding machine, characterized in that the lower end of the coil spring is in contact with the stepped portion (21c) is connected to the spring mounting hole (21b) and the installation hole (21a).
The method of claim 1,
The return means includes a cylinder housing 45a having an air channel 45 'for receiving high pressure air from the outside and a high pressure introduced into the cylinder housing 45a and introduced through the air channel 45'. Consists of a piston (45b) is raised by the air of
The lifting pin (30) is protruded from one end of the body 31, the hot runner valve device for injection molding machine, characterized in that to form a catching portion (35 ') in contact with the upper portion of the piston (45b).
delete The method of claim 1,
The body 21 is a hot runner valve device for an injection molding machine, characterized in that the lower surface is provided with a heat shield ring (w) made of a low thermal conductivity material.

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