KR20190036738A - Hotrunner system - Google Patents

Abstract

Disclosed in the present invention is a hot runner valve device capable of being opened and closed by a piston. In particular, the hot runner valve device comprises: a nozzle configured to receive a resin and guide the resin to a cavity of a mold, and including a resin channel and a nozzle tip integrally formed at a lower end portion thereof, wherein the resin channel through which the resin passes is formed in a center inside the nozzle; a piston provided inside the nozzle and configured to ascend and descend in response to a resin pressure, including inner and outer resin channels to permit the resin to flow in and out, including at one lower end thereof, a combining hole guiding the resin in the outer resin channel to be introduced into the inner resin channel, and including at a lower end portion thereof, a discharge tip discharging the resin, wherein the discharge tip is formed by decreasing a diameter of a lower end portion of the piston; a fixing pin whose one end is fixed inside the nozzle and whose the other end is disposed along the inner resin channel to block the discharge tip at an ascended position of the piston; and an elastic body configured to be caught by an outer one end of the piston and provide an elastic support force in an ascending direction. According to the present invention, as the piston filled with and surrounded by the resin is displaced by ascending due to a selectively applied flow pressure of the resin and a restoring strength of the elastic body, opening/closing of a gate of the piston is controlled by the fixing pin disposed in the center. Accordingly, the hot runner valve device does not require an additional driving source and thus may be configured compactly, by ensuring high operational reliability while having a simple structure. In particular, through a simple structural modification, when the resin is completely filled inside the cavity of the mold, the hot runner valve device induces pressure equilibrium and automatically blocks the gate. Thus, even for small-sized molded articles or precise molded articles that require balance, the present invention can ensure quality of the molded articles and also mass-producibility by allowing resin to be simultaneously applied from various different points.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-

The present invention relates to a piston opening / shutting type hot runner valve device, and more particularly, to a piston open / closed type hot runner valve device in which a piston filled in and out of a piston is lifted and lowered by a flow pressure of a resin selectively acting thereon and a restoring force of an elastic body, Since the opening and closing of the gate of the piston can be interrupted by the fixing pin, a separate driving source is not required, so that the structure is simple, the reliability of operation is ensured and the compact design is possible. Especially, And the gate can be automatically shut off by inducing a pressure balance phenomenon when the resin filling is completed.

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 valve apparatus for an injection molding machine for elevating and lowering a valve pin by using a high-pressure air as an operating pressure according to the prior art.

As shown in the figure, the valve apparatus of the injection molding machine for the multi-cavity mold of the prior art comprises a driving unit 100 and a valve unit 200, and high pressure air is used as a driving source for the elevating operation of the valve pin 210.

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 constructed as described above uses high-pressure air as an operating source for lifting and lowering the valve pin, it is necessary to employ a hermetic structure for preventing air leakage, (Compressors) are required, so that the structure becomes complicated due to the increase in volume, so that the installation space is limited, and maintenance and management are extremely poor.

In addition, when the present invention is applied to a multi-cavity mold having a plurality of nozzles, it is difficult to mass-produce a molded article having uniform quality due to the dispersion of dimensions of each nozzle.

In order to solve such a problem, a valve device according to the prior art is divided into a nozzle and a driving means. The nozzle receives the resin and forms a resin flow path for injecting the resin into the mold through the outlet provided at the tip end There has been proposed a structure in which a general valve structure is employed and a forward / reverse motor or a solenoid actuator for raising and lowering the valve pin by power supply is used as the driving means.

In the valve device having such a configuration, the entire size of the valve device can be downsized by adopting a structure in which a forward / reverse motor or an actuator driven by a power supply is employed as a driving source, so that the degree of freedom in designing a mold can be increased, The amount of movement of the pin can be controlled quickly and precisely.

However, in the valve devices of the present application filed by the present applicant, there is a disadvantage in that when a forward / reverse motor is used as a drive source, a reduction gear is provided and a cooling structure for cooling the motor is applied. .

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 the valve pin can not be smoothly driven at the time when the outlet moves from the opened or closed state to the relative position. This is not a solenoid actuator only. The valve pin in almost all hot runner devices is in the state that its end is inserted into the outlet when the outlet (gate) is shut off, and the other end is fitted in a bushing which supports linear movement. When the valve pin is lifted to open the outlet in this state, the stop resistance applied to the valve pin (the frictional resistance due to the supporting element such as the bushing supporting the valve pin and the frictional resistance when the outlet pin is fitted) It requires a considerable amount of power, that is, a large power. That is, most of the hot runner systems are driven by an output power higher than the rated output in order to overcome the frictional resistance acting at the time of moving to the relative position from the elevated or lowered state of the valve pin and to perform the lowering or raising operation In fact.

Accordingly, there is a problem that the manufacturing cost is increased due to a demand for a high output driving source (oil / air cylinder, station, motor, actuator), and since the volume is increased, a mold for molding a compact and precise molded article There is a problem that the degree of application is greatly restricted.

Particularly, there has been a problem in that when the product is molded by molding a compact and precise part, or by using a resin containing a glass fiber or magnesium component with poor fluidity, lifting and lowering of the valve pin is not smooth.

When the resin flows, the molten state is maintained by the heater wound around the outer surface of the nozzle. However, in the state where the resin flow is stopped, the temperature of the nozzle The resin is solidified due to the heat loss occurring at the end portion. As a result, the injection process must be temporarily stopped until the solidified resin is melted again. Therefore, the productivity is lowered and the solidified resin is not completely melted There was a closed end causing a molding failure.

In order to solve this problem, a high-frequency or low-pressure heating means has been conventionally installed so as to enable rapid heating of the end portion of the nozzle. However, due to rapid heating at the nozzle end portion, There is a serious problem that shortens the life of the product.

Further, since the high-frequency and low-pressure heating means are installed around the nozzles, the overall volume of the valve device becomes large, thereby limiting the degree of freedom of design. Furthermore, it is not applicable to a mold for mass production of compact and precise molded products. There is a difficulty in maintenance due to the complexity of the apparatus, and an additional cost for high-frequency and low-pressure equipment is required.

In order to solve such a problem, the present applicant has proposed a hot runner valve device for an injection molding machine in Korean Patent No. 10-1290549. In the claims, a manifold having a resin furnace and a resin connected to one side thereof are supplied And a nozzle having a heater wound around an outer circumferential surface thereof for guiding the mold to a cavity side of the mold, wherein the nozzle has a mounting hole formed at a center thereof and a reduced diameter at a lower side thereof And the resin is lifted by the supply pressure of the resin and lifted by the returning means to form a resin flow path which receives the resin as the center, A body formed with a flow resistance portion whose diameter is reduced so as to resist the pressure of the supplied resin, And a flow control tip provided with a reduced diameter at a lower end thereof and positioned inside the nozzle at the time of ascending movement and at the time of descending movement through the inlet and hole to contact the mold and a take- A hot runner valve device for an injection molding machine is disclosed.

In the hot runner valve apparatus for injection molding machine having such a constitution, the elevating operation of the elevating pin is interlocked by combining the supplying operation pressure of the resin supplied to the inside of the nozzle and the returning element and the opening and closing of the gate of the nozzle Since it is an intermittent structure, it does not require the driving means including the conventional complicated structure of the pneumatic-pressure cylinder, the forward motor or the actuator, the structure is simple and the degree of freedom in designing the mold can be increased. And the degree of freedom of installation can be improved.

The present applicant has proposed a hot runner valve device through Korean Patent No. 10-1154081 as a similar technology to the hot runner valve device for the injection molding machine. In claim 1 of the present invention, the resin is supplied through the inlet of one side And a nozzle which is guided to a cavity of the mold through a blow-out port that forms a reduced diameter of the other side and has a heater wound around the outer circumferential surface thereof. The hot runner valve device includes a nozzle A runner tip which is provided at one side of the body facing the air outlet port and through which the air outlet is selectively inserted and closed when the air inlet and the air inlet are closed, A connection for forming a space for filling the resin between the nozzle and the inner wall surface of the nozzle by removing one side The hot runner valve device according to claim 1,

The applicant of the present invention proposed a hot runner valve device improved by the Korean Patent No. 10-1588249 as a similar technology to the above hot runner valve device. In claim 1 of the present invention, the resin is supplied to the cavity of the mold Wherein the nozzle has a tubular body vertically penetrating therethrough and a diameter reduced to one side of the body, wherein the end of the nozzle is formed of resin And is selectively lifted and lowered to the cavity side by an elastic supporting force to maintain the protruding and retracted state, and is raised by the molding pressure of the resin in the cavity And contacts the one side of the gate portion with a relatively large area as compared with the lowered state, Induced lift bushing; A guide bushing which is coupled to the lower end of the nozzle so as to surround the outer surface of the elevating bushing and whose outer surface is in contact with the mold; The body portion and the gate portion are connected to each other by a screw connection, and the elevating bushing is provided so as to receive an elastic supporting force so that the elevating bushing is provided with an protruding / have. `

Since the hot runner valve apparatus according to the prior art can keep the flowing flowability of the resin satisfactorily as the opening and closing of the gate is interrupted by the runner pin without requiring a complicated structure driving means for opening and closing the gate of the nozzle, Good molding conditions can be obtained even for a resin containing this poor component.

However, in the hot runner valve apparatus according to the related art, it is ideal to supply the resin at various points with respect to the cavity, which is a molding space, in the case of a molded article requiring small precision and precision, However, due to the volume of the hot runner valve device, there is a structural disadvantage that it is practically impossible to supply resin at various points for a small-sized molded product.

Further, since the hot runner valve device of the applicant of the present application interrupts the resin supply to the cavity by utilizing the solidification phenomenon of the resin, when the viscosity of the molded product or the molded product or the resin which requires high precision is excessively low or high, There is a problem that the mass production of the molded article is deteriorated due to the clogging of the resin because the resin is not completely solidified at the time of blocking the resin, or the resin is not melted completely and is delayed at the time of supplying the resin.

Japanese Patent Application Laid-Open No. 10-1404071 (Apr. 29, 2014), "Side valve gate nozzle" Registered Patent Publication No. 10-1154081 (May 31, 2012), "Hot Runner Valve Device" Registered Patent Publication No. 10-1386361 (Apr. 4, 2014), 'Nozzle Device of Side Gate Type Hot Runner Injection Mold'

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to provide a method and apparatus for forming a gate in a nozzle by moving a piston, The lower end is opened to supply the resin to the cavity of the mold, and when the injection operation is stopped and the flow pressure of the resin is removed, the gate is structurally blocked by returning by the restoring force of the elastic body, And to provide a piston-openable type hot runner valve device capable of ensuring stable molding of small-sized and precision parts.

The piston-openable type hot runner valve device according to the first embodiment of the present invention is a piston-openable type hot runner valve device which is made up of a piston which is moved up and down by the flow of resin and the restoring force of an elastic body, It is possible to supply and shut off the resin only by the construction of the fixing pin which shields the mold, so that the structure of the existing complex structure is not required and the structure is simplified, thereby enhancing the convenience of maintenance and in particular, And to provide a piston-opening-type hot runner valve device capable of greatly increasing the freedom of application and the freedom of design.

The piston-openable type hot runner valve device according to the second embodiment of the present invention is constructed such that the resin is moved to the inside or outside and is raised by the flow pressure of resin acting upon injection to open the gate, The buoyancy piston that descends due to the restoring force of the valve to block the supply of the resin to intercept the supply of the resin increases the convenience of maintenance and enables a compact design, And to provide a piston-opening-type hot runner valve device.

It is a further object of the present invention to provide a method of manufacturing a semiconductor device which is capable of achieving a pressure balance when injection is completed in a process of injecting resin into a cavity of a mold through a simple structural modification, So that reliability and stability of the operation can be improved.

In order to achieve the above object, a piston-opening type hot runner valve device according to a preferred embodiment of the present invention is provided with a resin flow path through which resin passes through an inner center of a mold, A nozzle integrally provided with a tip; The nozzle is moved upward and downward to move downward when the resin pressure acts on the nozzle. The inner and outer guide grooves are formed to flow the resin into the inner and outer nozzles. And a lower end of the piston is formed with a piston, the diameter of which is reduced to form a discharge tip through which the resin is discharged; A fixing pin having one end fixed to the inside of the nozzle and the other end disposed along the inside water guide path to block the discharge tip at an elevated position of the piston; And an elastic body which is engaged with an outer end of the piston and acts to apply an elastic supporting force in an upward direction.

According to a preferred embodiment of the present invention, the piston is formed with a flow resistance portion which is connected to the inner wall of the piston while gradually decreasing in diameter and progressing downward at the upper end thereof so that the piston is lowered by the hydraulic pressure supplied through the nozzle; An upper end is supported by a locking protrusion formed by protruding one end of the piston, and a lower end is supported on one side of the nozzle to elastically support the elastic body. When the hydraulic pressure acting on the lowered piston is released, .

According to another aspect of the present invention, there is provided a method of manufacturing an ink jet recording head, comprising the steps of: inserting the ink into one end of the nozzle, fixing the upper end of the fixing pin to the inside thereof, sliding the upper end of the piston, And a branching path for guiding the resin to be branch-fed.

In another preferred aspect of the present invention, the piston is provided with a branch hole for receiving the resin from the resin flow path of the nozzle and branching and guiding the resin to the inner and the outer resin, wherein the branch hole has a resin passing amount .

A piston-opening type hot runner valve device according to another preferred embodiment of the present invention is a device for supplying a resin and guiding a resin to a cavity of a mold, in which a resin flow path through which resin passes is formed at an inner center, and a nozzle and; The nozzle tip is moved backward from the nozzle tip to open the nozzle tip, and the inner and outer guides are formed so that the resin flows into the inside and the outside of the nozzle tip, A buoyant piston in which a connecting resin hole joining the outer resin rods is formed; The lower end portion is slidably inserted into the upper inner surface of the buoyancy piston and the upper end portion thereof is inserted into the nozzle to supply the resin supplied through the resin flow path, thereby forming a branch path at one end, bushing; And an elastic body which is engaged with one end of the fixed bushing and whose other end is hooked on the upper outer surface side of the buoyant piston so that when the resin pressure acting on the buoyant piston is released, the elastic body is returned to its original position by an elastic force.

In another preferred aspect of the present invention, the connecting resin hole of the buoyant piston has a relatively large flow rate of resin passing through the branched path of the fixed bushing.

A piston-opening type hot runner valve apparatus according to the present invention is a piston-open type hot runner valve apparatus in which a piston through which a resin flows into and out of a piston is moved by the flow pressure of a resin as an injection pressure so that a lower end portion, The injection of resin is restored by the restoring force of the elastic body in the state where the injection operation is stopped and the flow pressure of the resin is removed so that the supply of the resin is cut off, So that it is expected to have a useful effect of ensuring reliable supply of a stable resin for small and precision parts and stable molding.

In other words, the piston-opening type hot runner valve device according to one embodiment of the present invention can completely and precisely control the discharge of the resin as the gate through which the resin is discharged is structurally opened or shielded during the lifting operation of the piston, There is an advantage that quality can be expected to be improved.

Further, the piston-opening type hot runner valve device of the present invention is configured such that the filling of the resin with respect to the cavity of the mold is completed regardless of the action of the injection pressure through a simple structure change that adjusts the flow amount of the resin flowing into and out of the piston It is possible to automatically shield the gate as the pressure equilibrium occurs. Therefore, it is expected to provide a stable effect of supplying and blocking the resin without precise control of the injection timing.

In particular, since the working pressure of the resin is used without using a separate driving source, the discharge port is mechanically blocked with the solidification phenomenon of the resin, so that defects due to the phenomenon that the undegraded resin flows down can be prevented at the source. A useful effect is expected in the industry that can enhance reliability.

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 showing a hot runner valve apparatus according to the prior art,
2 is a cross-sectional view of a piston-opening type hot runner valve apparatus according to a first embodiment of the present invention,
Figs. 3 to 5 are enlarged views for explaining the operation of the piston-opening type hot runner valve apparatus according to the first embodiment of the present invention; Fig.
6 and 7 are exploded perspective views for explaining the internal configuration of the piston-opening type hot runner valve apparatus according to the first embodiment of the present invention,
8 and 9 are exploded perspective views for explaining a component configuration of a piston-opening type hot runner valve apparatus according to the first embodiment of the present invention,
10 is a cross-sectional view showing a piston-opening type hot runner valve apparatus according to a second embodiment of the present invention,
Figs. 11 to 13 are enlarged views for explaining an operation configuration of a piston-opening type hot runner valve apparatus according to a second embodiment of the present invention; Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, configurations and operations of embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. It is noted that the terms "comprises" or "having" in this application are intended to specify the presence of stated features, steps, operations, components, parts, or combinations thereof in one or more other features or acts, , Components, parts, or combinations thereof, as a matter of convenience, without departing from the spirit and scope of the invention. That is, throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Also, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, a detailed description of well-known functions and configurations that unnecessarily obscure the gist of the present invention will be omitted so as not to obscure the gist of the present invention. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

FIG. 2 is a cross-sectional view of a piston-opening type hot runner valve apparatus according to a first embodiment of the present invention, and FIGS. 3 to 5 illustrate an operation configuration of a piston-open type hot runner valve apparatus according to a first embodiment of the present invention Fig. 4 shows a state in which the gate is opened and the resin is injected into the cavity C, which is the molding space of the mold M, and Fig. 5 shows a state in which the gate is opened. And the molding is completed for the molded product and the gate is shut off.

6 and 7 are exploded perspective views for explaining the internal configuration of the piston-opening type hot runner valve apparatus according to the first embodiment of the present invention, and Figs. 8 and 9 are cross- 1 is an exploded perspective view for explaining a component configuration of the openable type hot runner valve device. FIG. 2 is a valve-less type in which no driving means such as a conventional hydraulic cylinder or actuator for opening and closing the gate of the nozzle 20 is constituted. (Not shown) in which a resin is supplied from an injection cylinder (not shown) and branching and supplying the resin is provided, and the mold is connected to one side of a manifold A nozzle 20 having a heater h wound around an outer circumferential surface thereof for injecting resin into a cavity (not shown) of a nozzle (not shown) And the lower end of the lower end portion is formed with a discharge hole through which the resin is discharged to discharge the resin, A piston formed with a tip; A fixing pin having one end fixed to the inside of the nozzle and the other end disposed along the inner water guide path to block the discharge tip at an elevated position of the piston and an elastic body engaged with an outer end of the piston to exert an elastic supporting force in an upward direction A piston-openable hot runner valve device is shown.

Meanwhile, in the present invention, an injection molding machine for melting a resin and injecting the resin at a predetermined pressure, and a manifold for supplying the molten resin from the injection molding machine and branching and feeding the resin may be performed by well-known techniques, and a detailed description thereof will be omitted.

Referring to the drawings, the present invention will be described with reference to the drawings. The present invention includes a nozzle 20 for supplying molten resin through a manifold or a resin supply element and guiding the molten resin to a molding space of a mold, A flow resistance portion is formed on the upper side to form a sloped surface which is gradually reduced in diameter while being moved downward. A piston 30 and an elastic body S for returning the position of the piston 30 and a fixing pin 10 positioned inside the piston 30 and having one end fixed to the nozzle 20.

The nozzle 20 is a guide element for receiving the resin and guiding the resin to the cavity of the mold. The resin flow path 28 through which the resin passes is formed at the center of the nozzle 20, and the nozzle tip 23 is integrally provided at the lower end to be.

The nozzle 20 has a body 21 on which an electric heater is wound and a heater h which is a heating element that is supplied with electric power and generates heat by electrical resistance and a screw fastening or interference fit structure A nozzle tip 23 for guiding and supporting a piston 30 to be described later, the nozzle tip 23 having a lower end in the inside thereof, A guide pipe 25 inserted into one end of the body 21 and guided and supported by sliding the piston 30 into an inner center of the piston 21, A fixed runner 27 fitted into the upper portion of the body 21 so as to regulate its position when lifted up and having a resin flow path 28 formed at an inner center of the fixed runner 27 and the heater 23, The It consists of a casing (20a) for covering a portion not to be exposed.

The body 21 is a hollow hollow cylindrical member which is connected to the manifold or the resin connecting member 10 on the upper side with reference to the drawing to provide an inlet for receiving the resin, The nozzle tip 23 is engaged so that the molding space of the mold is discharged into the cavity after the resin passes through the piston 30 to be described later. The body 21 is provided so that the heater h is wound around the outer surface of the body 21 to keep the molten state of the resin passing through the body 21 without solidification. do.

The nozzle tip 23 is formed to have a diameter decreasing as it moves toward the cavity side of the mold and is formed so as to penetrate through the center of the nozzle tip 23 so that the piston 30 can protrude and retreat. However, the present invention discloses a structure in which the body 21 and the nozzle tip 23 are processed separately and then assembled by screwing in order to facilitate processing and diversification of materials. The nozzle tip 23 having such a configuration may also be implemented by a known technique.

The piston 30 is an elevating element provided in the nozzle 20 so as to be able to move up and down. The piston 30 is located inside the nozzle tip 23 during the elevation and is concealed. When the nozzle 30 is lowered, And is projected outward to be discharged to discharge the resin.

In other words, the piston of the present invention is provided to be lifted up and down in the nozzle, and is lowered under the action of the resin pressure. The resin flows into the inside and the outside, And a lower end portion of the lower end portion is configured to form a discharge tip through which the resin is discharged by reducing the diameter of the lower end portion. And the flow resistance portion connected to the inner wall is formed while the diameter gradually decreases.

The piston 30 is a tubular member having a hollow shape and is formed at an inner center of the piston 30 in a straight line with the resin flow path 28 of the nozzle 20 to form a resin- A flow resistance portion connected to the water resistance guide 31 is provided so that the resin pressure acts on a wide area.

In the piston 30 having the above-described structure, when the resin passing through the resin flow path 28 of the nozzle 20 passes through the flow resistance portion and flows into the internal resin path 31, As shown in the figure, the inclined surface having a reduced diameter is included in the downward direction. As a result, when the resin passing through the nozzle 20 is supplied to the piston 30, The resin pressure greatly acts to generate a resistance force. As a result, the piston 30 moves downward with reference to the drawing.

Accordingly, as the piston 30 moves downward, one or a plurality of gates formed on the lower sidewall of the piston 30 are exposed to the outside of the nozzle tip 23, resulting in the resin being discharged through the gate, As shown in FIG.

The elastic body S is engaged with an upper end portion of the elastic body S which is formed by protruding one end of the piston 30 and a lower end portion of the elastic body S is engaged with the inner side of the guide pipe 25, Is a returning element that exerts an elastic supporting force for returning to the position when the resin pressure is removed.

Such an elastic body is supported by an engagement protrusion formed by projecting one end of the upper end of the piston, and the lower end is supported on one side of the nozzle to act as an elastic supporting force. When the hydraulic pressure acting on the lowered piston is released, It is preferable that a coil spring be used.

That is, the elastic body S of the present invention has one end supported by the piston 30, which is one of the lifting elements, and the other end supported by one end of the nozzle 20, which is a stationary element. When the resin is supplied to the inside of the piston 30 through the nozzle 20, the piston 30 performs a lowering operation in conjunction with the supply pressure of the resin When the resin supply pressure acting on the piston 30 is removed, the sacrifice piston 30 must be moved up.

 In addition, the elastic body (S) in the present invention may be replaced with various driving sources or structures in addition to a spring having elasticity repulsive force and having a structural characteristic capable of returning the piston (30). For example, It is also possible to apply a cylinder type which is a working pressure or a motor or an actuator.

FIG. 10 is a cross-sectional view of a piston-opening type hot runner valve apparatus according to a second embodiment of the present invention, and FIGS. 11 to 13 illustrate an operation configuration of a piston-open type hot runner valve apparatus according to a second embodiment of the present invention .

The piston-opening type hot runner valve apparatus according to the present embodiment includes a nozzle having a resin flow path through which resin flows into the center of the mold and a nozzle tip integrally formed at a lower end thereof, The nozzle tip is moved backward from the nozzle tip to open the nozzle tip, and the inner and outer guides are formed so that the resin flows into the inside and the outside of the nozzle tip, A buoyant piston in which a connecting resin hole joining the outer resin rods is formed; The lower end portion is slidably inserted into the upper inner surface of the buoyancy piston and the upper end portion thereof is inserted into the nozzle to supply the resin supplied through the resin flow path, thereby forming a branch path at one end, A bushing; And an elastic body which is engaged with one end of the fixed bushing and whose other end is engaged with the upper outer surface side of the buoyant piston so that when the hydraulic pressure acting on the buoyant piston is released,

It is proposed that the connection resin hole of the buoyant piston has a relatively large flow rate of the resin passing through the branched path of the fixed bushing. In this configuration, when injection of the cavity of the metal mold is completed, The resin injection pressure no longer acts. Therefore, the buoyant piston is lowered by the elastic restoring force of the elastic body (S) to block the gate.

With this configuration, the piston-opening type hot runner valve apparatus according to the second embodiment of the present invention can improve the convenience of operation since it is not necessary to precisely control the gate closing timing using the injection pressure of the resin.

It is to be understood that the present invention is not limited to the disclosed embodiment and that various changes and modifications may be made without departing from the spirit and scope of the present invention as set forth in the appended claims. It is obvious to those who have knowledge. It is therefore intended that such variations and modifications fall within the scope of the appended claims.

1: Hot runner valve device 10: Fixing pin
20: nozzle 21: body
23: nozzle tip 28: resin flow path
30: piston 30a: branch hole
30b: confluence hole 31:
33: Outside resin 35: Discharge tip
39: bushing h: heater
C: cavity M: mold
R: molded product S: elastomer

Claims (6)

A nozzle for receiving a resin and guiding the resin to a cavity of the mold, the nozzle having a resin flow passage through which the resin passes and a nozzle tip integrally formed at a lower end;
The nozzle is moved upward and downward to move downward when the resin pressure acts on the nozzle. The inner and outer guide grooves are formed to flow the resin into the inner and outer nozzles. And a lower end of the piston is formed with a piston, the diameter of which is reduced to form a discharge tip through which the resin is discharged;
A fixing pin having one end fixed to the inside of the nozzle and the other end disposed along the inside water guide path to block the discharge tip at an elevated position of the piston;
An elastic body engaged with an outer end of the piston to exert an elastic supporting force in an upward direction;
Wherein the piston-opening-type hot runner valve device comprises: The method according to claim 1,
Wherein the piston is formed with a flow resistance portion which is connected to the inner wall of the piston while gradually decreasing in diameter as the piston moves downward at an upper end thereof in order to perform a lowering action by a hydraulic pressure supplied through the nozzle;
The elastic body is supported on an upper end of a locking protrusion formed by protruding one end of the piston, and the lower end of the elastic body is supported on one side of the nozzle to apply an elastic supporting force. When the hydraulic pressure acting on the lowered piston is released, Coil springs;
Wherein the piston-openable-type hot runner valve device comprises: The method according to claim 1,
The upper end of the fixing pin is fixed to the inside of the nozzle, and the upper end of the piston is slidably inserted into the nozzle so that the resin is guided to be branched and supplied to the inner and outer guides A bushing forming a branching path;
Further comprising: a valve body having a first end and a second end; The method according to claim 1,
Wherein the piston is provided with a branch hole for receiving the resin from the resin flow channel of the nozzle and for branching and guiding the resin to the inner and the outer resin, and the branch hole has a larger resin passing amount relative to the confluence hole. A hot runner valve device. A nozzle for receiving a resin and guiding the resin to a cavity of the mold, the nozzle having a resin flow passage through which the resin passes and a nozzle tip integrally formed at a lower end;
The nozzle tip is moved backward from the nozzle tip to open the nozzle tip, and the inner and outer guides are formed so that the resin flows into the inside and the outside of the nozzle tip, A buoyant piston in which a connecting resin hole joining the outer resin rods is formed;
The lower end portion is slidably inserted into the upper inner surface of the buoyancy piston and the upper end portion thereof is inserted into the nozzle to supply the resin supplied through the resin flow path, thereby forming a branch path at one end, bushing;
An elastic body which is engaged with one end of the fixed bushing and whose other end is hooked on an upper outer surface side of the buoyant piston so that when the hydraulic pressure acting on the buoyant piston is released,
Wherein the piston-opening-type hot runner valve device comprises: The method according to claim 1,
Wherein the connecting resin hole of the buoyant piston has a relatively large flow rate of resin passing through the branched path of the fixed bushing.

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