KR101951789B1 - Sidegate Valve system of Hotrunner - Google Patents

Abstract

The present invention discloses a resin pressure-relief valve device for a hot runner.
A valve device of a resin pressure-relief type of a hot runner according to the present invention is a tubular element which is hollowed to receive resin and guide the resin into a cavity of a mold, a nozzle having a heater wound around its outer surface, A lifting runner pin having a tubular shape hollowed to allow the resin to pass therethrough and having an upper edge formed with an inclined surface having a reduced diameter while being downwardly moved so as to be lowered under the action of a hydraulic pressure, And a return spring for returning the position when the resin pressure acting on the main resin is released, wherein the lift-up runner pin is a main resin in which the resin flows to the inner center, A runner tip on which an outlet for discharging the resin is formed, and an upper side surface of the runner tip, A horizontal bar disposed at both sides of the nozzle tip so as to cross the inlet hole and fixed to the inside of the nozzle tip, and a center of a lower surface of the horizontal bar projecting toward the runner tip, And a runner opening / closing part formed of a fixing pin inserted into the air outlet to block the resin flow.
The resin pressure-relief valve device of the present invention having the above-described structure is configured such that a main resin path is formed in the inside of the lifting runner pin and a bypass resin is formed in the outside, Since the resin is configured to flow and discharge, the resin penetrates into the gap formed by machining error or thermal expansion on the outer surface of the previous lifting runner pin and solidifies, resulting in a situation where the lifting operation of the lifting runner pin is disabled And provides a useful effect that can be solved.

Description

[0001] The present invention relates to a side gate valve system of a hot runner,

The present invention relates to a valve device for opening and closing a resin spring of a hot runner having a lifting / lowering runner pin which is raised and lowered by a hydraulic pressure to intermittently open / close the gate of a nozzle. More specifically, The present invention relates to a resin-pressure-opening-type valve apparatus of a hot runner capable of preventing malfunctioning due to a phenomenon in which a resin is solidified, thereby ensuring stable resin discharge and enhancing reliability of operation.

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.

However, in the hot runner valve device for injection molding according to the related art, since the pressure of the resin passing through the inside of the lift pin is very high, it flows into the gap between the outer surface of the lift pin and the inner surface of the nozzle, Which not only deteriorates the reliability of the operation but also causes a serious problem that the operation becomes impossible when the inflow resin is solidified.

The present applicant has proposed a hot runner valve apparatus through Korean Patent No. 10-1154081 as a similar technology to the hot runner valve apparatus for the injection molding machine. In claim 1 of the present invention, the resin is supplied through the inlet hole on one side And a nozzle which is guided to a cavity of a mold through a blow-out port that forms a reduced diameter of the other side and is wound around a heater on an 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 outlet are connected to each other by connecting the body and the runner tip, Which forms a space in which resin is filled between the nozzle and the inner wall surface of the nozzle by removing one side of the nozzle The hot runner valve device further comprising a runner pin made up of a combination of the first and second valves.

The hot runner valve device with such a configuration can maintain the flowability of the resin satisfactorily as the gate is opened and closed 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 the resin containing the component.

However, in the hot runner valve apparatus according to the related art, since the pressure of the resin to be passed through the nozzle is very high, it greatly acts on the inner tip side of the nozzle. At this time, most of the resin is discharged to the mold through the gate of the nozzle, but some resin flows into the gap between the outer surface of the runner pin and the inner surface of the nozzle, resulting in poor runningability of the runner pin, There is caused a problem that the runner pin can not be moved up and down.

In addition, since the hot runner valve apparatus according to the related art is required to have a high precision dimension so as to have an appropriate clearance (3/1000 mm) with respect to the assembling components which are opposed to each other so that the lifting and lowering runner can smoothly move, And there is a problem that the mass productivity is low.

For example, in the case where the clearance between the part to be assembled with the lifting runner pin and the parts to be assembled is 4/1000 mm or more, the resin is infiltrated and solidified through the gap, causing the lifting runner pin to become inoperable, When the clearance between the runner pin and the parts to be assembled is less than 2/1000 mmk, there is a risk that the lifting operation becomes impossible due to friction with parts assembled when the lifting runner pin is heated by the thermal expansion of the metal There was a problem.

Therefore, a clearance for lifting and lowering operation is required in consideration of thermal expansion of the metal, and the workability is extremely poor, which is difficult to economically produce and has a serious problem of low durability.

Meanwhile, in the case of the lifting runner pin having a shape that is hollow and has a hollow shape so that the resin flows into the inner center of the lifting runner pin and the outlet is formed so that the resin is discharged to the lower end thereof, When the resin injection into the cavity of the mold is completed, that is, in the state where the lifting and lowering runner pin is moved upward, the resin should not flow down to maintain a proper solidification state. When the lifting and lowering runner pin is lowered, However, since the solidification and fluidization conditions of the resin differ depending on the temperature of the resin, the temperature of the nozzle, and the physical properties of the resin, it takes a long time to find the optimum extraction condition and there is a need to depend on the skill of the operator.

For example, in a state in which the lifting runner pin is lifted, the resin is not fully solidified as the temperature of the outlet to which the resin is discharged is rapidly lowered, and the resin is maintained in an appropriate solidified state. However, when the temperature of the resin is high or the fluidity is high, the resin flows down through the outlet without being solidified. To lower the temperature of the resin, the flowability of the entire resin is lowered In addition to being not only poor, but also in a state where the lifting runner pin is elevated, it takes a long time to fluidize even when the lifting runner pin is lowered due to the solidification, resulting in a problem that normal resin discharging becomes impossible.

Registered Patent Publication No. 10-1290549 (Feb. 23, 2013), 'Hot Runner Valve Device for Injection Molding Machine' Registered Patent Publication No. 10-1154081 (May 31, 2012), "Hot Runner Valve Device"

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 of manufacturing a resin- And the resin flowing into the outer surface of the lifting runner pin is retained by the previous machining error or thermal expansion, and the hot runner Pressure valve-opening type valve device.

In order to achieve the above object, according to a preferred embodiment of the present invention, a resin pressure-

The valve device of the resin pressure-relief type of the hot runner according to the present invention is a structure for lifting and lowering the lifting runner pin by using the resin pressure and the elastic return means without requiring a separate driving source. The structure is simple and there is an advantage that the maintenance and the handling of the product are very easy since the driving mechanism such as the pneumatic cylinder or actuator including the mechanism is not required.

That is, in the resin-pressure-opening type valve apparatus of the hot runner of the present invention, the lift-up runner pin is lowered or lifted by the supply pressure of the resin supplied from the injection molding machine to open the gate of the nozzle to supply resin into the cavity of the mold, The supply pressure of the resin is removed, and the lift-up runner pin returns to the original position due to the elastic restoring force of the elastic returning means, thereby shutting off the gate of the nozzle. Therefore, a complicated mechanism for opening and closing the gate of the previous nozzle It is expected to have a useful effect of greatly increasing the freedom of designing and the freedom of application to the mold by reducing the volume as well as enhancing the convenience of maintenance because the drive source is not required.

In particular, in the valve apparatus of the present invention, the resin pneumatic valve is provided with a fixed punching pin fixed to the inner surface of the nozzle on the upper side of the inner outlet of the lifting runner pin lifted by the resin pressure, The temperature of the resin staying in the lifting sprung pin can be rapidly increased during the descent of the lifting runner pin, and the temperature of the resin can be quickly removed through the outlet port As a result, it is possible to prevent a phenomenon in which the resin discharged into the outlet of the lifting runner pin becomes solidified due to solidification of the resin, and in the case of the resin having a good flowability in the state of lifting the lifting runner pin, It is possible to solve the phenomenon of flowing out of the lifting runner pin. As a result, It provides a useful effect that can stop.

Particularly, in the resin-pressure-opening type valve apparatus of the hot runner of the present invention, since the main resin path is formed in the inside of the lifting runner pin and the bypass resin is formed in the outside, So that the resin is infiltrated into the gap formed by the machining error or thermal expansion on the outer surface of the previous lifting runner pin and solidified. As a result, the lifting operation of the lifting / lowering runner pin is disabled It provides a useful effect that can be achieved.

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,
FIGS. 2 and 3 are sectional views for explaining a configuration of a resin pressure-relief valve device of a hot runner according to an embodiment of the present invention;
FIGS. 4 and 5 are cross-sectional views for explaining a configuration of a resin pressure-relief valve device of a hot runner according to another embodiment of the present invention;
FIG. 6 is an exploded perspective view of a resin pressure relief valve device of the hot runner of FIG. 4 according to the present invention,
7 and 8 are cross-sectional views showing a state in which the main components shown in Fig. 7 are disassembled in the resin pressure-relief valve device of the hot runner according to the present invention.

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.

FIGS. 2 and 3 are cross-sectional views for explaining a configuration of a resin pressure-relief valve device of a hot runner according to an embodiment of the present invention. FIGS. 4 and 5 are cross- FIG. 6 is an exploded perspective view showing a main part of a resin pressure-relief valve device of the hot runner of FIG. 4 according to the present invention. FIG. 6 is an exploded perspective view showing a main part of the present invention, The configuration for implementing the operation in which the lifting runner pin 30 is displaced upward and downward by the lifter pin 30 is the same, except that the shape of the lifting runner pin 30 and the coupling structure of the peripheral accessories are different. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as set forth in the following claims.

The figure shows a nozzle 20 in which a molten resin is supplied from an injection cylinder and a heater h is wound on the outer surface of the nozzle 20 so as to guide and inject the molten resin into a cavity (not shown) of the mold. The guide bushing 40 is slidably inserted into the guide bushing 40 and is movable up and down. When the resin pressure is lowered, the main resin passes through the inner center of the guide bushing 40 And a return spring (50) for returning the position when the hydraulic pressure acting on the elevating runner pin (30) is released. The hydraulic pressure shutoff type valve device (1) of the hot runner Respectively.

7 and 8 are views showing a state in which the main components shown in Fig. 2 are disassembled in the resin pressure-relief valve device of the hot runner according to the present invention.

In the figure, a plurality of guide grooves 43 are formed on the lower side of the nozzle 20 in such a manner that the upper and lower surfaces of the nozzle 20 are coupled and fixed to the inside of the nozzle tip 24 constituting the lower end of the nozzle 20, The upper and lower surfaces of the bushing body 41 are slidably inserted into the bushing body 41 so that the upper and lower surfaces of the upper and lower surfaces are opened. An outflow hole 33a is formed in the upper side surface and an inflow hole co33b is formed in the lower side surface to be connected to the main resin path 30a. A lifting spanner pin 30 in which a locking protrusion 37 is slidably fitted in the guide groove 43 of the bushing body 41 and a return spring 30 for lifting the lifting / 50 are shown.

That is, the figure shows a nozzle tip 24 forming a lower portion of the nozzle 20, and an upper portion of the lift-up runner pin 30 is slidably inserted into the upper portion of the nozzle tip 24, And a step enlarging hole portion 41b whose diameter is relatively increased with respect to the pin insertion hole portion 41a. The side surface of the step enlarging hole portion 41b is formed with a guide groove 41b in the direction perpendicular to the drawing, A guide bushing 40 formed of a bushing body 41 having a bushing 43 formed therein and a movable element that is slidably assembled in the guide bushing 40 to be elevated and lowered, And the resin flowing through the resin path 20a of the nozzle 20 toward the center of the flow resistance section 35 is transferred to the main resin path 30a, The main resin which forms the inlet so as to be moved to the inlet An outflow hole 33a through which a part of the resin introduced through the resin path 20a is discharged and a lower outer side surface 33b of the outflow hole 33a are connected to the main resin path 30a, And the resin flowed out through the outflow hole 33a is introduced into the main resin path 30a so as to flow into the main resin path 30a again. The upper end of the runner body 33 is engaged with an outer surface of the runner body 33 and the lower end of the nozzle tip 24 And a return spring 50 which is engaged with the inner lower side to exert upwardly resilient supporting force so that the lifting runner pin 30 can be moved upward. Since the upper end of the lifting runner pin 30 in which the outlet hole 33a is formed is inserted into the pin insertion hole 41a of the guide bushing 40 in a state of being lifted up, When the resin is not discharged but the elevating runner pin 30 is lowered due to the action of the resin pressure, the resin flows out as the outflow hole 33a is positioned in the step extension hole portion 41b of the guide bushing 40 Flows to the return spring 50 side and then flows into the inside of the lifting / lowering runner pin 30 through the inlet hole 33b and finally discharged through the linear outlet 31a formed in the runner tip 31.

The present invention is characterized in that it is fixed to a bushing 65 which is disposed across the outlet hole 33a and fixed to the inner surface of the nozzle tip 24 and which is fixedly projected at the lower end of the lifting runner pin 30 The pin 63 is inserted into the outlet 31a of the lifting runner pin 30 to prevent the resin from flowing and the resin can be taken out by opening the outlet when the lifting runner pin 30 is lowered .

The construction of the resin pressure-relief valve device of the hot runner according to the present invention will now be described in detail with reference to the drawings.

A valve device (1) for a resin pressure-relief valve of a hot runner according to the present invention is an element for supplying molten resin through a manifold or other connecting pipe and guiding the molten resin to a cavity, which is a molding space of a mold, A nozzle 20 having a resin 20a on which a molten resin is to be moved, and a nozzle 20, which is provided so as to be able to move up and down within the nozzle 20, The flow resistance portion 35 is formed on the upper surface of the main resin path 30 so that a resin pressure is applied to the upper surface of the main resin path 30a. A plurality of outlet holes 33a and an inlet hole 33b connected to the resin passage 30a through which the resin flows are respectively formed and a lower end surface of the outlet hole 33a is provided with a plurality of Hanging chin 37) are spaced apart from each other and fixed to the inside of the nozzle (20) by a fixing element which slidably engages with an upper part of the lifting runner pin (30) And a guide bushing 40 for allowing the resin to flow out through the outflow hole 33a when the lifting runner pin 30 descends and to form the bypass resin 30b on the outer surface of the lifting runner pin 30 It is a technical feature.

The nozzle 20 includes a body 23 wound with a heater h which is provided in a hollow hollow cylindrical shape and is supplied with power to the outer circumferential surface and generates heat by electric resistance, A nozzle tip 24 for supporting the runner tip 31 of the lifting runner pin 30 to be described later so that the diameter of the nozzle tip is reduced while the lower end of the nozzle tip is connected to the nozzle tip 24, A nozzle cap 25 mounted on the upper side of the body 23 and a cover 21 covering the body 23 to prevent the heater h from being exposed to the outside. That is, the nozzle 20 according to the present invention mainly includes a cover 21 which forms an outer body, and a cover 21 which is provided inside the cover 21. The cover 20 is open at its upper and lower surfaces and its outer surface is wound with a heater h A body 23 on which a resin 20a for resin flows is formed and a nozzle 23 connected to a lower portion of the body 23. A nozzle tip 24, to which a guide bushing 40 is fixedly coupled, Respectively.

The body 23 is connected to a nozzle cap 25 for providing an inflow hole to receive resin upward on the basis of the figure and on the opposite side to the guide bushing 40 and a lifting runner pin 30, and then the nozzle tip 24 is connected to the cavity, which is a molding space of a mold (not shown).

The nozzle tip 24 may be formed to have a reduced diameter in its outer diameter as it proceeds toward the cavity side of the mold and may be integrally formed with the body 23. In the present invention, And the tip 24 and the body 23 are separately machined and assembled by screwing.

The nozzle 20 having such a structure is an element for receiving the molten resin and guiding it to the lifting / lowering runner pin 30 which can be raised and lowered therein, and may be implemented by a known technique, and thus a detailed description thereof will be omitted do. However, the nozzle 20 of the present invention is characterized in that it includes a guide bushing 40 positioned above the nozzle tip 24 and supporting the lift pin 30.

The guide bushing 40 is coupled or fixed to the inside of the nozzle tip 24 constituting the nozzle 20 by a screw fastening or by a tight fitting structure so that a lifting operation of a lift pin 30 So that the resin flows out to the outer surface of the lifting runner pin 30 when the lifting runner pin 30 is lowered to form a bypass resin 30b.

The guide bushing 40 is a support element having an open top and a bottom in the form of a hollow tube for supporting a lifting and lowering runner pin 30 to be described later, A stepped hole portion having a diameter enlarged with respect to the pin insertion hole portion is formed at a lower portion of the pin insertion hole portion, And a bushing body having guide grooves formed in a direction perpendicular to the slide protrusions formed on the lower outer surface of the slide portion of the lifting runner pin.

The lifting runner pin 30 includes a runner body 33 formed largely of a slide portion 33-1 and an extended end portion 33-2 and a lower end portion 33b provided at a lower portion of the runner body 33, And a runner tip 31 which is a portion which is projected and withdrawn through the lower portion.

The runner body 33 is provided with a main resin path 30a in which a resin flows in the center of its upper and lower surfaces in a tubular shape having a hollow shape and is slidably inserted into the pin insertion hole 41a, An extending end portion 33-2 extending in the lengthwise direction of the slide portion 33-1 and a plurality of protrusions 37 protruding from the lower outer surface of the slide portion 33-1, An outflow hole 33a formed on one side of the main resin passage 30a and penetrating the resin to flow out to the outside and an outlet hole 33a located on the lower side of the extending end 33-2, Is formed in the main resin passage 30a so as to be re-introduced into the main resin passage 30a.

Here, the upper surface of the slide portion 33-1 is provided with a flow resistance portion 35 formed with a sloped surface whose diameter is reduced in a downward direction so that the pressure of the resin can be greatly increased. The flow resistance portion 35 When the resin passing through the nozzle 20 is supplied to the lifting runner pin 30, the resin force is induced in the flow resistance portion 35 so that the resin force acts to a large extent, (30) is moved down by the supply pressure of the resin.

The runner tip 31 is integrally formed on the lower side of the runner body 33 and has a reduced diameter. The runner tip 31 protrudes outside the nozzle tip 24 constituting the nozzle 20, It is an element to charge. The runner tip (31) is provided with a linear outlet port (31a) through which the resin of the main resin path (30a) is discharged to the outside. The linear outlet 31a is connected to the main resin passage 30a in a vertical line so as to discharge the resin to the lower surface of the runner tip 31. [

The lifting runner pin 30 having such a configuration is formed with an outflow hole 33a on the outer surface of the slide portion 33-1 to be slidably inserted into the pin insertion hole portion 41a, The resin in the main resin passage 30a does not flow out as the pin 30 is positioned in the pin insertion hole 41a of the guide bushing 40 in a state in which the pin 30 is moved upward, The resin in the main resin passage 30a flows out as the portion of the outflow hole 33a is positioned on the side of the step extension hole portion 41b of the guide bushing 40 And the resin thus discharged is filled in the space between the outside of the elevating runner pin 30 on which the return spring 50 is installed and the inside of the nozzle tip 24 to form the bypass resin path 30b. The resin on the bypass resin path 30b flows into the main resin path 30a through the inflow hole 33b formed through the side of the extending end 33-2 of the lifting runner pin 30 and merged And is ejected through the linear ejection port 31a.

The return spring 50 is hooked on an upper end portion of a latching protrusion formed by protruding one end of the runner body 33, and the lower end portion of the return spring 50 is hooked on the inner side of the nozzle tip 24. That is, the nozzle 20 is provided with a space in which the return spring 50 can be installed on the inner circumferential surface of the nozzle tip 24 coupled by screwing, and the return spring 50, And the lower end portion is hooked on the inner end of the nozzle tip 24 to restrict the movement of the nozzle tip 24 in the upward direction.

The return spring 50 having such a configuration is provided to have an elastic repulsive force smaller than the supply pressure of the resin acting on the lifting runner pin 30 through the nozzle 20, When the resin is supplied to the inside of the lifting runner pin 30, the lifting runner pin 30 performs a lowering operation in conjunction with the supply pressure of the resin. On the contrary, when the resin supply pressure acting on the lifting runner pin 30 is removed, The pin 30 must be moved up

The return spring 50 according to the present invention may be replaced with various driving sources or structures as long as the return spring 50 has a structural characteristic capable of returning the lifting runner pin 30. For example, It may be applied or a motor or an actuator may be applied.

Hereinafter, the operation of the hot runner valve apparatus according to the present embodiment will be described.

When the molten resin flows into the resin passage 20a of the nozzle 20, the molten resin flows into the guide bushing 40, which is engaged with the nozzle tip 24 of the nozzle 20, Is introduced into the main resin passage 30a through the inlet port a with the main resin of the main resin passage 30.

At this time, since the inner side of the upper surface of the lifting runner pin 30 is formed with the flow resistance portion 35 formed by decreasing the diameter while moving downward, the pressure of the resin acts on the flow resistance portion 35 As a result, the lifting runner pin 30 is moved downward to be exposed to the outside of the nozzle tip 24 constituting the nozzle 20. At the same time, the resin flowing along the main resin path 30a is discharged through the linear outlet port 31a The resin is injected into the cavity of the mold.

In the state where the lifting runner pin 30 is lowered, the slide portion 33-1 constituting the upper portion of the runner body 33 is positioned in the pin insertion hole 41a of the guide bushing 40 The resin is discharged through the outflow hole 33a formed on the side of the slide part 33-1 and the return spring 50 is moved toward the step expansion hole part 41b, And the introduced resin flows back to the main resin passage 30a through the inlet hole 33b formed in the side of the extending end portion 33-2 constituting the lower portion of the runner body 33, And is discharged through the linear outlet port 31a of the runner tip 31. [

That is, in a state in which the lifting runner pin 30 is lowered, the resin supplied to the lifting runner pin 30 is guided along the main resin path 30a of the runner body 33 to the linear outlet 31a of the runner tip 31 Through the straight outlet port 31a of the runner tip 31 through the outflow hole 33a formed in the runner body 33 and the bypass resin passage 30b formed in the inlet hole 33b, As a result, in the state in which the lifting and lowering runner pin 30 is moved downward, the resin flows in both the inside and the outside.

Then, when resin filling of the cavity of the mold is completed, the resin supply pressure acting on the lifting runner pin 30 is removed as the injection operation is stopped in the injection cylinder. Therefore, the lifting sprung pin 30 is moved upward by the resilient restoring force of the return spring 50 provided between the outer surface of the lifting runner pin 30 and the nozzle tip 24, thereby achieving the position return.

At this time, as the outflow hole 33a of the lifting runner pin 30 is positioned in the pin insertion hole 41a of the guide bushing 40, the residual resin is prevented from flowing.

The present invention is also characterized in that it is fixed to a bushing 65 which is disposed across an outflow hole 33a and fixed to an inner surface of a nozzle tip 24 and is fixed to a lower end of the lifting runner pin 30 The pin 63 is inserted into the outlet 31a of the lifting runner pin 30 to prevent the resin from flowing and the resin can be taken out by opening the outlet when the lifting runner pin 30 is lowered .

That is, the present invention further includes a runner opening / closing part 60. The runner opening / closing part 60 includes a transverse bar 61 disposed to cross an inlet hole provided in the elevator runner pin 30, And a fixing pin 63 that protrudes from the lower center of the transverse bar 61 toward the runner tip 31 of the elevating runner pin 30 and has a diameter enough to pass through the through hole 31a do.

The fixing pin 63 is inserted into the air outlet 31a when the lifting ramp pin 30 is lifted and the resin filled in the lifting ramp pin 30 flows completely through the outlet of the runner tip 31 And when the lifting runner pin 30 descends, the outlet 31a of the runner tip 31 is opened to allow the resin to be taken out. At this time, the runner opening / closing part 60 is provided with copper or a copper alloy having a high thermal conductivity, so that heat of the heater h wound on the outer surface of the nozzle tip 24 is received and maintained in the heating state. It is possible to maintain the molten state so that the resin staying in the upper part of the mold can be discharged immediately without being solidified.

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
20: nozzle 21: cover
23: Body 24: Nozzle tip
30: Lift-up runner pin 30a: Main resin
30b; Bypass resin 31: Runner tips
31a: an air outlet 31b, 31c: a branch air outlet
33: Runner body 33a: Outflow hole
33b: Inflow hole 35: Flow resistance part
37; Jaw 40: Guide bushing
41: bushing body 41a: pin insertion hole portion
41b: step expansion hole portion h: heater
50: return spring 60: runner opening /
61: transverse bar 63: fixing pin

Claims (4)

A nozzle having a heater on its outer surface, and a tube which is provided so as to be lifted up from the inside of the nozzle and which is hollowed so that the resin passes through the inner center of the nozzle, The lifting sprue pin is provided with a flow resistance portion formed with an inclined surface whose diameter is decreased while being moved downward so as to be lowered at the action of the hydraulic pressure, and a return spring Wherein the valve mechanism is a valve mechanism of a hydraulic pressure shut-off type,
The runner pin has a main resin through which the resin flows into the center of the inner race, a runner tip formed with an outlet through which the resin is discharged to the lower end side of the main resin, and an inlet hole through which the resin passes ;;
A transverse bar which is arranged to cross the inlet hole and has both side ends fixed to the inside of the nozzle tip, and a transverse bar which is protruded toward the runner tip at the center of the lower surface of the transverse bar, And a runner opening / closing part composed of a fixing pin for blocking the opening / closing part,
And a pin insertion hole portion in which an upper portion of the lifting runner pin is slidably inserted and raised is formed on the upper side of the pin insertion hole portion, And a guide bushing having a stepped expansion hole portion having a diameter expanded,
The lifting runner pin is formed on an upper outer surface that is slidably inserted into the pin insertion hole portion and is shielded by a pin insertion hole portion at the time of lifting and is located at a stepped expansion hole portion when the lifting pin is lowered, And an inlet hole formed in a lower surface of the lower surface of the latching protrusion for hooking the upper end of the return spring and through which the resin flowing out through the outlet hole is introduced again Wherein the valve body is a valve body. delete The apparatus of claim 1, wherein the nozzle comprises:
A body having a top and a bottom which are opened and which are provided in a hollow tube shape and in which a resin flows at the center thereof;
And a guide bushing which is assembled so that the lifting runner pin is lifted and lowered is coupled and fixed to the lower portion of the body, A nozzle tip whose lower end protrudes when it is lowered;
Wherein the valve body is a valve body of the valve body. delete

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