JP2012232437A - Liquid resin supply mechanism, and compression molding device equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new liquid resin supply mechanism that can supply a constant amount of liquid resin to a mold with high reproducibility by properly processing stringing resin.SOLUTION: The liquid resin supply mechanism 1 discharges the liquid resin 200 downward from a nozzle 2 with a built-in gate valve 5, and supplies the liquid resin 200 to one of the molds. An outer peripheral air blowing port 3 for blowing air toward a nozzle tip end at the lower side is arranged at the outer periphery of the nozzle 2. A gate valve 5 is opened and the liquid resin 200 is discharged by a control signal from a control circuit 9. When finishing the discharge of the liquid resin 200, the gate valve 5 is closed and the control for blowing the air at the predetermined temperature from the outer peripheral air blowing port 3 is performed to maintain the liquid resin 200 in a liquid state.

Description

  The present invention relates to a liquid resin supply mechanism of a resin molding apparatus and a compression molding apparatus provided with the liquid resin supply mechanism.

  Examples of resin molding using a mold include injection molding, compression molding, and blow molding. Among these resin moldings, injection molding uses a closed mold and fills the cavity with liquid resin injected from the nozzle through the sprue, runner, and gate in the mold, and heats and cools to solidify. It is a method to do. Compression molding is a method in which a liquid resin is opened from a nozzle toward one of the molds, a fixed amount is discharged, the mold is closed and compressed, and the reaction is solidified by heating or cooling while being applied in the mold. . Blow molding is a system in which air is blown into a resin set in a mold to swell and react to solidify.

  Injection molding and compression molding can use a mold having a complicated internal shape, and are suitable for manufacturing a molded part with high dimensional accuracy. Of these, injection molding can be mass-produced in a short time, but extra materials such as sprues, runners, and gates are produced, so the amount of resin material consumed even if recovered and reused. Becomes larger. On the other hand, compression molding requires more time to open and close the mold than injection molding, but it eliminates the need for extra materials such as sprues, runners, and gates, thus minimizing the consumption of resin materials. it can.

  Resin materials used for injection molding and compression molding include thermosetting resins and thermoplastic resins. A thermosetting resin is a resin that undergoes a polymerization reaction when heated to form a polymer network structure and is cured (solidified). Once cured, it does not become liquid when heated. At that time, a relatively low molecular liquid resin having a fluidity level is fed into a mold at room temperature, formed into a predetermined shape by the mold, and then heated and cured. A thermoplastic resin is a resin that becomes soft when heated to the glass transition temperature or melting point and can be molded into the desired shape. A liquid resin that is fluid at high temperatures is fed into the mold at high temperatures. Then, it is formed into a predetermined shape by a mold, and then cooled and hardened (solidified).

  Thermosetting resins and thermoplastic resins have a certain degree of viscosity even in a liquid state. In injection molding and compression molding, liquid resin is discharged from the nozzle, but even if the discharge valve (gate valve) is closed, stringing occurs between the nozzle tip and the resin supplied to the lower mold, and the liquid resin is discharged. It takes time to finish. For example, if the stringing continues while the nozzle is retracted outside the mold, the resin will adhere to the parting surface of the lower mold (the mating surface between the molds), and the mold will become fouled. Various problems such as incomplete parallelism between molds when the mold is closed are caused. Therefore, at the manufacturing site, the stringed resin may be removed by wiping with a spatula, cloth, sponge or the like.

  As measures for stringing resin at the tip of the nozzle, it is conceivable to wipe off the resin that has been threaded by wiping with a spatula, cloth, sponge, or the like, or by blowing compressed air. Here, as a method disclosed in a known patent document, for example, there is Patent Document 1. In Patent Document 1, in molding of a container cap, a tube head or the like, a thermoplastic resin is extruded in an annular shape, and then the annular resin is extruded to gradually reduce the opening cross-sectional area of the nozzle, and by a gas flow from the gas nozzle It is described that it is separated from the extrusion nozzle as a lump and dropped.

Japanese Patent Publication No.64-7850

  However, in the method described in Patent Document 1, the thermoplastic resin is extruded in a ring shape, separated from the extrusion nozzle in a lump and dropped, and therefore a resin having a considerably high viscosity is used. A resin having a viscosity much higher than that of a liquid resin having a viscosity that causes the phenomenon of stringing at the same time is used. Moreover, since the method described in Patent Document 1 is a method of extruding a high-viscosity resin in a ring shape, the method is limitedly applied to hollow molded articles such as container caps and tube heads. And in the method of extruding a high-viscosity resin in a ring shape as described in Patent Document 1, and separating and dropping in a lump from an extrusion nozzle, it is difficult to reduce the amount of resin supply, and a small amount of an accurate resin A small molded product cannot be manufactured by supplying the amount into the mold or using a mold having a complicated internal shape.

  The stringing phenomenon in the present application is, for example, in common with the stringing phenomenon found in viscous oil, water tanks, etc. When a liquid resin having such a viscosity is discharged from the nozzle, the nozzle is closed even if the gate valve is closed. Threading occurs between the tip and the resin supplied to the lower mold, and the threaded resin remains at the tip of the nozzle, and it takes time to finish discharging. As countermeasures for stringing resin at the tip of this nozzle, it is conceivable to wipe off the stringed resin by wiping with a spatula, cloth, sponge, etc., or by blowing compressed air. The problem that the amount of resin supplied to the mold varies cannot be solved. In recent years, it has been found that this stringing resin contributes to manufacturing variations in manufacturing a highly accurate resin molded product. That is, by removing the above-described stringed resin, an unstable state such as a decrease in the amount of resin supplied to the mold is caused, which causes a variation in the weight of the molded part. On the other hand, if the above-mentioned thread-drawn resin is waiting until it falls from the tip of the nozzle, it takes a long time to finish the discharge, and it is affected by the outside air, resulting in variations in the appearance and quality deterioration of the molded parts. It can be a factor. For example, precision parts such as resin lenses must be manufactured with high precision and the same dimensions with good reproducibility, and it is desired to supply a certain amount of liquid resin to the mold with high reproducibility. However, there is still no effective improvement method.

  Accordingly, an object of the present invention is to appropriately process the stringing resin in a liquid resin supply mechanism that supplies the resin to one of the open molds by discharging the liquid resin downward from the nozzle. Accordingly, an object of the present invention is to provide a novel liquid resin supply mechanism capable of supplying a predetermined amount of liquid resin to a mold with high reproducibility, and a compression molding apparatus equipped with the liquid resin supply mechanism.

  The liquid resin supply mechanism of the present invention is a liquid resin supply mechanism that is controlled by a control circuit and discharges the liquid resin downward from a nozzle having a built-in gate valve to supply the liquid resin to one of the molds. In addition, an outer peripheral air outlet is provided outside the nozzle to blow out outer peripheral air having a predetermined temperature to maintain the liquid state of the discharged liquid resin in the nozzle tip direction on the lower side.

  According to the present invention, an outer peripheral air outlet that blows the outer peripheral air at a predetermined temperature that maintains the liquid state of the discharged liquid resin in the direction of the nozzle tip on the lower side is disposed outside the nozzle. By blowing out the liquid resin, the liquid resin threaded from the nozzle tip can be separated and dropped downward while maintaining the liquid state of the discharged liquid resin.

  The liquid resin supply mechanism of the present invention is a liquid resin supply mechanism that is controlled by a control circuit and discharges the liquid resin downward from a nozzle having a built-in gate valve to supply the liquid resin to one of the molds. The shaft center of the gate valve is formed with a center air blowing hole for blowing out the center air at a predetermined temperature for maintaining the liquid state of the discharged liquid resin downward from the tip thereof. To do.

  According to the present invention, since the axial center of the gate valve is formed with an axial air blowing hole for blowing axial air at a predetermined temperature, which maintains the liquid state of the discharged liquid resin, downward from its tip. By blowing out the air, the liquid resin threaded from the nozzle tip can be separated and dropped downward while maintaining the liquid state of the discharged liquid resin.

  That is, the present invention is characterized in that by blowing out the air, the liquid resin threaded from the nozzle tip is separated and dropped downward while maintaining the liquid state of the discharged liquid resin.

  In the present invention, the resin is a thermoplastic resin, and the air temperature is set to be equal to or higher than the melting temperature of the thermoplastic resin, or the resin is a thermosetting resin, and the thermosetting The air temperature is set so as to be lower than the heat polymerization temperature of the resin.

  According to the present invention, the stringing resin is dropped in a liquid state, and the resin that has already been discharged into one of the molds is prevented from solidifying with the air. Since the resin discharged to one mold and the stringing resin are assimilated in a liquid state, the product quality becomes more stable. The air temperature is set to an appropriate temperature in consideration of the temperature of the liquid resin when discharged from the nozzle and the temperature of the surrounding environment, and is set to a temperature lower than the combustion temperature of the liquid resin. Among the air, the outer peripheral air and the axial air may have different air temperatures, or the air temperatures may be the same.

  Examples of the air include air, dry air, and inert gases such as nitrogen gas and argon gas. When the resin is a general thermoplastic resin or thermosetting resin, air or dry air can be applied, and it can be easily used from factory piping. In the case where the resin is easily oxidized, the oxidation of the resin can be suppressed by using an inert gas such as nitrogen gas or argon gas. Among the air, the outer peripheral air and the axial air may have different air components, or the air components may be the same component.

  The present invention is characterized in that the air blowing port has an outer cylinder shape arranged on the outer periphery of the nozzle, and the nozzle and the air blowing port are each tapered.

  According to this embodiment, since the air is blown out over the entire circumference of the nozzle tip by forming the air outlet in the shape of an outer cylinder arranged on the outer periphery of the nozzle, The stringed liquid resin is surely dropped in the discharge direction of the liquid resin from the nozzle. And since the nozzle and the air outlet are each tapered, there is an effect that the air is blown in accordance with the tapered shape of the tip of the nozzle to make the stringing resin thinner.

  In the present invention, it is preferable that the shape of the discharge surface (outlet) at the tip of the nozzle and the shape of the blow-out surface (outlet) at the tip of the air outlet are concentric with each other. The liquid resin is discharged evenly, the gate valve is closed, and the air is blown out, so that the liquid resin stringed from the nozzle tip is thinned and cut off evenly and dropped downward. As the concentric shape, for example, the discharge surface at the tip of the nozzle is circular, and the discharge surface at the tip of the air outlet is an annular shape. Examples of the configuration include an ellipse shape, and a blowout surface at the tip of the air blowout port has an ellipse shape.

  The present invention is characterized in that the tip of the gate valve is pointed and the tip of the gate valve protrudes from the tip of the nozzle when the discharge of the liquid resin is finished.

  According to the present invention, when the discharge of the liquid resin is finished, the pointed tip of the gate valve protrudes from the tip of the nozzle, so that the cross-sectional area of the starting point of the stringing resin can be reduced as much as possible. Since the air is blown toward the pointed tip shape, it surely hits the root of the liquid resin threaded by the gate valve tip, and is dropped from the starting point with the smallest cross-sectional area of the stringer resin. Further, the gate valve repeats retreating into the nozzle and protruding from the tip of the nozzle, and liquid resin is discharged every time following the pointed tip-shaped surface. Even if a slight amount of resin adheres to the tip, the tip of the gate valve is cleaned (washed) each time the liquid resin is discharged. The air blowing hole formed in the shaft center of the gate valve is for cutting off the starting point of the thinned stringing resin. A small hole diameter is sufficient for the air blowing hole, and the hole diameter should be reduced. It is more preferable because the back flow of the liquid resin into the pores can be prevented.

  The liquid resin supply mechanism of the present invention is applied to a resin molding apparatus, and particularly to a resin molding apparatus used in a compression molding machine. Here, the configuration of the resin supply device is not limited as long as it is a device capable of plasticizing and melting or mixing and cooling the resin and supplying a predetermined amount of the resin. For example, an extrusion type that plasticizes the resin and extrudes a predetermined amount only by rotating the screw, a pre-plastic type that extrudes the extruded molten resin after storing it in a separate device and then pushes it back and forth, or a screw rotation An in-line screw type in which the screw is moved back and weighed after being plasticized, and the screw is pushed forward and pushed out. Incidentally, the pre-plastic resin supply device is characterized by high measurement accuracy and high reproducibility of the supply amount. By applying the liquid resin supply mechanism of the present invention to the pre-plastic resin supply device, it is possible to supply a certain amount of resin to the mold device with higher reproducibility. The resin supply apparatus to which the present invention is applied, when supplying resin to the lower mold, continuously or intermittently while moving horizontally up and down, left and right or up and down with respect to the lower mold. You may make it supply resin freely to the predetermined position of a metal mold | die.

  According to the liquid resin supply mechanism of the present invention, by blowing out air at a predetermined temperature that maintains the liquid state of the liquid resin, the liquid resin threaded from the nozzle tip is separated and dropped into one of the molds. be able to. According to the present invention, when the resin is a thermoplastic resin, the air temperature is set to be equal to or higher than the melting temperature of the thermoplastic resin, and when the resin is a thermosetting resin, Since the air temperature is set to be lower than the heating polymerization temperature of the thermosetting resin, the stringing resin is dropped in a liquid state and is already discharged into one of the molds. Is solidified by the air, and the resin already discharged into one of the molds and the stringing resin are assimilated in a liquid state, so that the quality of the product becomes more stable. In addition, since the air is blown along the tapered shape of the nozzle tip over the entire circumference of the nozzle tip by forming an outer cylindrical air outlet arranged on the outer periphery of the nozzle, the nozzle The liquid resin threaded at the tip is surely dropped in the discharge direction of the liquid resin from the nozzle. And when the discharge of the liquid resin is finished, the pointed tip of the gate valve protrudes from the tip of the nozzle, so that the cross-sectional area of the starting point of the stringing resin can be reduced as much as possible, and the pointed tip shape of the gate valve Since the air is blown toward the end of the gate valve, it surely hits the root of the liquid resin threaded at the tip of the gate valve and drops from the starting point with the smallest cross-sectional area of the stringer resin.

  Further, according to the present invention, the axial air blowing hole for blowing the axial air at a predetermined temperature for maintaining the liquid state of the discharged liquid resin downward from the tip thereof is formed in the axial center of the gate valve. By doing so, the starting point of the thinned stringing resin is more reliably cut off. The gate valve repeats retreating into the nozzle and protruding from the tip of the nozzle, and liquid resin is discharged every time following the sharp tip-shaped surface. Even if a small amount of resin adheres, the tip of the gate valve is cleaned (washed) each time the liquid resin is discharged. Therefore, the present invention provides a compression molding apparatus equipped with a novel liquid resin supply mechanism that can appropriately process the stringing resin and supply a predetermined amount of liquid resin to the mold with high reproducibility.

It is a structural diagram which shows the nozzle of the liquid resin supply mechanism of the 1st Embodiment of this invention, (a) is a side view, (b) is a bottom view. It is sectional drawing which looked at the nozzle of the said embodiment from the side surface side. It is sectional drawing which looked at operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which advanced the said nozzle. It is sectional drawing which looked at operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which opened the gate valve and discharged liquid resin from the said nozzle. It is sectional drawing which looked at the operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which closed the gate valve and started air blowing. It is sectional drawing which looked at operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which completed air blowing. It is sectional drawing which looked at operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which retracted the said nozzle. It is another example of the structure figure which shows the nozzle of the liquid resin supply mechanism of the said embodiment, (a) is a side view, (b) is a bottom view. It is a flowchart figure which shows the resin molding procedure to which the liquid resin supply mechanism of embodiment of this invention is applied. It is structural drawing which shows the nozzle of the liquid resin supply mechanism of the 2nd Embodiment of this invention, (a) is a side view, (b) is sectional drawing seen from the side surface side. It is sectional drawing which looked at operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which opened the gate valve and discharged liquid resin from the said nozzle. It is sectional drawing which looked at operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which closed the gate valve and started the air blowing from an axial center. It is structural drawing which shows the nozzle of the liquid resin supply mechanism of the 3rd Embodiment of this invention, (a) is a side view, (b) is sectional drawing seen from the side surface side. It is structural drawing which shows the nozzle of the liquid resin supply mechanism of the 4th Embodiment of this invention, (a) is a side view, (b) is sectional drawing seen from the side surface side. It is sectional drawing which looked at operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which opened the gate valve and discharged liquid resin from the said nozzle. It is sectional drawing which looked at operation | movement of the nozzle of the said embodiment from the side surface side, and is a figure of the state which closed the gate valve and started the air blowing from an axial center.

  Specific embodiments to which the present invention is applied will be described below with reference to the drawings.

(First embodiment)
FIG. 1A is a side view showing a nozzle of the liquid resin supply mechanism according to the first embodiment of the present invention, and FIG. 1B is a bottom view thereof. FIG. 2 is a cross-sectional view of the nozzle of this embodiment as viewed from the side. The liquid resin supply mechanism 1 of the present embodiment discharges the liquid resin 200 downward from the nozzle 2 in which the gate valve 5 is built, and supplies the liquid resin 200 to one of the molds. An outer peripheral air outlet 3 for blowing air (outer peripheral air) in the direction of the nozzle tip on the lower side is disposed on the outer periphery of the nozzle 2. When the discharge and the discharge of the liquid resin 200 are finished, the gate valve 5 is closed, and control is performed to blow out the peripheral air at a predetermined temperature that maintains the liquid state of the liquid resin 200 from the peripheral air outlet 3.

  As shown in FIGS. 1A and 1B, the liquid resin supply mechanism 1 of this embodiment is a cylindrical and tapered nozzle 2 in which a cylindrical liquid supply pipe 29 is integrally formed. A temperature controller 4 is disposed on the outer periphery of the liquid pipe 29. The temperature controller 4 is a hollow and spiral pipe, and can be cooled by flowing a medium such as water or gas in the pipe, or the pipe itself can be heated as a heater. For example, when the resin 200 is a thermosetting resin, an appropriate temperature range equal to or higher than the temperature at which no condensation occurs at a temperature lower than the heat polymerization temperature of the thermosetting resin in order to be a liquid resin having a fluidity level. It cools with the temperature controller 4 so that it may become. For example, when the resin 200 is a thermoplastic resin, it is heated by the temperature controller 4 so as to be in an appropriate temperature range above the melting temperature and below the combustion temperature in order to be a liquid resin having a fluidity level. . In addition, the liquid feeding pipe | tube 29 and the nozzle 2 are not limited to the form of Fig.1 (a) (b), Each may be formed separately and may be made to connect mutually. Moreover, the temperature controller 4 is not limited to the form of FIG.1 (a) (b), What is necessary is just what can be temperature-controlled so that the resin 200 turns into a liquid resin of the level which has fluidity | liquidity.

  An outer peripheral air outlet 3 for blowing air toward the lower nozzle tip (reference numeral 53) is disposed outside the nozzle 2 (FIGS. 1A and 1B). The outer peripheral air outlet 3 has an outer cylindrical shape arranged on the outer periphery of the tip of the nozzle 2 and has a tapered shape that is similar to the tapered shape of the tip of the nozzle. The outer peripheral air outlet 3 has a hollow cylindrical shape and is connected with an air pipe 39. The air pipe 39 is connected to an air supply source (not shown), and is set to blow out air at a predetermined temperature that maintains the liquid state of the liquid resin 200 from the blowing surface 33 (outlet 33) of the outer peripheral air blowing port 3. . When the resin 200 discharged from the discharge surface 23 (exit 23) of the nozzle 2 is a thermosetting resin, the heating polymerization temperature of the thermosetting resin is set so as to be a liquid resin having a fluidity level. Air that is set to a predetermined temperature (outer peripheral air) is blown out so that the temperature is within a temperature range that is less than the temperature that does not condense. For example, when the resin 200 is a thermoplastic resin, the outer peripheral air set to a predetermined temperature so as to be in a temperature range higher than the melting temperature and lower than the combustion temperature in order to be a liquid resin having a fluid level. Blow out.

  In this embodiment, as shown in FIG. 1B, the shape of the discharge surface 23 at the nozzle tip and the shape of the tip blowing surface 33 of the outer peripheral air blowing port 3 are concentric shapes corresponding to each other. Yes. That is, the discharge surface 23 at the tip of the nozzle has a circular shape, and the blow-out surface 33 at the tip of the outer peripheral air blow-off port has an annular shape, and is concentric.

  In the present embodiment, a gate valve 5 having a pin shape and a sharp tip is incorporated in the nozzle 2 (FIG. 2). The gate valve 5 is mechanically connected to a drive source (not shown) and is controlled by a control signal from the control circuit 9 so that the gate valve 5 moves forward and backward by driving force such as hydraulic pressure, air pressure, and motor (in FIG. To work). That is, when discharging the liquid resin 200, the gate valve 5 is retracted (in the example of FIG. 4 raised up), and the discharge surface 23 at the tip of the nozzle is opened. When the discharge of the liquid resin 200 is finished, the gate valve 5 is moved forward (raised downward in the example of FIG. 6), and the discharge surface 23 at the tip of the nozzle is closed. In this embodiment, when the discharge of the liquid resin 200 is finished, the tip 53 of the gate valve 5 protrudes from the discharge surface 23 at the tip of the nozzle (FIGS. 2, 3, 6, etc.).

(Resin molding procedure according to the present invention)
9A and 9B are flowcharts showing a resin molding procedure in a compression molding machine to which the liquid resin supply mechanism 1 according to the embodiment of the present invention is applied. 3 to 7 are sectional views showing a series of operations of the nozzle 2 of the liquid resin supply mechanism 1 of the first embodiment. Here, assuming that the resin 200 is a thermoplastic resin, a resin molding procedure by a manufacturing method to which the liquid resin supply mechanism 1 of the present invention is applied will be described below in accordance with the flowchart shown in FIG.

  First, the upper mold 51 and the lower mold 52 of the mold 50 are opened, and the nozzle 2 of the liquid resin supply mechanism 1 is advanced, or moved back and forth, left and right, and up and down to stop just above the cavity 521 ( Reference S1, FIG. 3). The temperature controller 4 acts as a heater, and heats the thermoplastic resin 200 so as to be in an appropriate temperature range above the melting temperature and below the combustion temperature so that the liquid resin has a fluidity level. . At this time, the gate valve 5 is lowered, the tip 53 thereof protrudes from the discharge surface 23 at the nozzle tip, and the discharge surface 23 at the nozzle tip is closed (the gate valve 5 is closed). The lower mold 52 is heated to an appropriate temperature by a heater built in the lower mold 52 so that the thermoplastic resin 200 becomes a liquid resin having a fluid level. The upper mold 51 is also heated to an appropriate temperature by a heater built in the lower mold 52.

  When the mold 50 is opened and the nozzle 2 is advanced to a predetermined position (reference S1), the gate valve 5 is then opened by the control signal from the control circuit 9 to open the liquid resin 200 on the lower side. The liquid is discharged toward the cavity 521 (reference S2, FIG. 4). The tip of the nozzle 2 has a tapered shape, and the liquid resin 200 is discharged in a predetermined direction. Depending on the size and shape of the cavity 521, the nozzle 2 of the liquid resin supply mechanism 1 may be moved back and forth, right and left or up and down so that the liquid resin 200 is spread over the bottom surface of the cavity 521.

  When the gate valve 5 is opened and the liquid resin 200 is quantitatively discharged into the lower cavity 521 (reference S2), the gate valve 5 is lowered by a control signal from the control circuit 9, and its tip 53 is the tip of the nozzle. The discharge surface 23 of the nozzle is closed (reference S3), and immediately after the gate valve 5 is closed, the liquid resin 200 is discharged from the discharge surface 33 (outlet 33) of the outer peripheral air discharge port 3. The air (outer peripheral air) at a predetermined temperature that maintains the liquid state is blown out (reference S4, FIG. 5). An arrow 302 in FIG. 5 indicates the flow of the peripheral air. The outer peripheral air 302 blown out from the outer peripheral air outlet 3 is in an appropriate temperature range above the melting temperature and below the combustion temperature so that the thermoplastic resin 200 becomes a liquid resin having a fluidity level. Heated air.

  According to this embodiment, when the discharge of the liquid resin 200 is finished, the sharp tip 53 of the gate valve 5 protrudes from the discharge surface 23 at the tip of the nozzle, so that the cross-sectional area of the starting point of the stringing resin 202 can be minimized. (FIG. 5). Then, since the heated outer peripheral air 302 is blown toward the pointed tip shape 53 of the gate valve 5, it surely hits the root of the liquid resin 202 threaded by the gate valve tip 53, and the cross-sectional area of the stringing resin 202 is reduced. It will drop from the smallest starting point. Further, the stringing resin 202 at the tip of the nozzle 2 tends to solidify due to the influence of the ambient temperature. According to this embodiment, the tapered shape of the tip of the nozzle 2 extends over the entire circumference of the tip of the nozzle 2. Accordingly, the outer peripheral air 302 is blown, so that the heated outer peripheral air 302 keeps the stringed liquid resin 202 in a liquid state or is remelted to be in a liquid state and pushed out downward. The liquid resin 202 threaded by the sharp tip 53 of the gate valve 5 is reliably dropped in the liquid resin discharge direction from the nozzle 2 (FIG. 6).

  Further, in the present embodiment, the shape of the discharge surface 23 (exit 23) at the tip of the nozzle 2 and the shape of the blowout surface 33 (outlet 33) at the tip of the outer peripheral air blowout port 3 are concentric circles corresponding to each other. (FIG. 1 (b)), the liquid resin 200 is discharged evenly, the gate valve 5 is closed, and the outer peripheral air 302 is blown off, whereby the liquid is drawn into the pointed tip 53 of the gate valve 5. The resin 202 is thinned and cut without unevenness and dropped downward. The stringing resin 202 is dropped in a liquid state, and the resin 200 already discharged into the cavity 521 of the lower mold 52 is prevented from being solidified by the outer peripheral air 302. The discharged resin 200 and the stringing resin 202 are assimilated in a liquid state (FIG. 6), and the product quality is more stable. The timing of blowing the peripheral air 302 from the peripheral air outlet 3 is preferably blown immediately after the supply of the liquid resin 202 is finished and the gate valve 5 is closed, but at the same time as the gate valve 5 is closed. The peripheral air 302 may be blown, or the peripheral air 302 may be blown immediately before the gate valve 5 is closed, that is, the control from the control circuit 9 according to various conditions such as the properties of the liquid resin 202 and the ambient environment temperature. Signal transmission timing can be adjusted as appropriate.

  When the gate valve 5 is closed, the heated outer peripheral air 302 is blown out from the outer peripheral air outlet 3 (reference S4), and the supply of the liquid resin 200 to the cavity 521 is completed, the outer peripheral air 302 stops being blown out (reference numeral S4). S5) The nozzle 2 is retracted and the mold 50 is closed (reference S61, FIG. 7). Then, the resin 200 is molded in the mold 50 by, for example, heating and compressing, cooling and solidifying by reaction (reference S62), and after molding, the mold 50 is opened and the molding resin is taken out (reference S63).

  In the above resin molding procedure, the resin 200 has been described as being a thermoplastic resin. However, the resin 200 can be used as a thermosetting resin, and in this case, condensation occurs at a temperature lower than the heat polymerization temperature of the thermosetting resin. Cool with the temperature controller 4 so that the temperature is within an appropriate temperature range. And the outer periphery air 302 set to the predetermined temperature will be blown out so that it may become the temperature range more than the temperature which is less than the heat polymerization temperature of the said thermosetting resin, and no dew condensation.

  Examples of the outer peripheral air 302 blown out from the outer peripheral air outlet 3 include air, dry air, and inert gases such as nitrogen gas and argon gas. When the resin 200 is a general thermoplastic resin or thermosetting resin, air or dry air can be applied, and it can be easily used from factory piping. When the resin 200 is a material that is easily oxidized, the oxidation of the resin 200 can be suppressed by using an inert gas such as nitrogen gas or argon gas.

  FIG. 8A shows a side view showing a nozzle of another example of the liquid resin supply mechanism 1 of the first embodiment, and FIG. 8B shows a cross-sectional view thereof. Here, the same reference numerals represent the same functions, and description thereof will be omitted as appropriate. The liquid resin supply mechanism 1 of the present embodiment has an outer peripheral air outlet that blows out outer air at a predetermined temperature that maintains the liquid state of the liquid resin 200 discharged from the nozzle 2 toward the lower nozzle tip on the outside of the nozzle 2. 3 is arranged. The outer peripheral air outlet 3 of the present embodiment has an outer cylindrical shape disposed on the outer periphery of the tip of the nozzle 2 and has a tapered shape that is similar to the tapered shape of the nozzle tip. The outer peripheral air outlet 3 has a hollow cylindrical shape, and a cylindrical air pipe 39 is connected to the back side thereof. The air piping 39 is disposed so as to surround the outer periphery of the liquid feeding pipe 29 of the liquid resin 200, and the temperature controller 4 is disposed so as to surround the outer periphery of the air piping 39. According to the present embodiment, the outer peripheral air 302 is blown with a more uniform pressure along the tapered shape of the tip of the nozzle 2 over the entire circumference of the tip of the nozzle 2. Further, the direction in which the liquid resin 200 is discharged from the nozzle 2 may be on the lower side, and as shown in FIGS. 8A and 8B, the liquid resin 200 is inclined at an angle of about 30 to 45 degrees from directly below. Can also be discharged.

(Second Embodiment)
FIG. 10A shows a side view showing a nozzle of the liquid resin supply mechanism of the second embodiment of the present invention, and FIG. 10B shows a cross-sectional view thereof. Here, the same reference numerals represent the same functions, and description thereof will be omitted as appropriate. In addition to the first embodiment described above, the liquid resin supply mechanism 1 of the present embodiment supplies axial air at a predetermined temperature that maintains the liquid state of the liquid resin 200 discharged from the nozzle 2 from its tip (reference numeral 53). An axial air blowing hole that blows out downward is formed. The axial air blowout hole 35 is connected to an air supply source (not shown) and is set to blow out air at a predetermined temperature that maintains the liquid state of the liquid resin 200 from the tip 53 of the axial center of the gate valve 5. Yes.

  In the present embodiment, when the resin 200 discharged from the discharge surface 23 (exit 23) of the nozzle 2 is a thermosetting resin, the thermosetting resin is used so as to be a liquid resin having a fluidity level. The outer peripheral air and the axial air that are set to a predetermined temperature are blown out so as to be within a temperature range that is less than the temperature at which the resin is heated and does not form condensation. For example, when the resin 200 is a thermoplastic resin, the outer peripheral air set to a predetermined temperature so as to be in a temperature range higher than the melting temperature and lower than the combustion temperature in order to be a liquid resin having a fluid level. And blow out the axial air. Here, the air blowing hole 35 formed in the shaft center of the gate valve 5 is for cutting off the starting point of the thin thread drawing resin 202, and the inside diameter of the air blowing hole 35 may be small. Further, by reducing the diameter of the hole, there is an effect of preventing the back flow of the liquid resin 200 into the hole. The diameter of the axial air blowing hole 35 is appropriately set according to the properties of the liquid resin 202. For example, in the case of the liquid resin 202 having a high liquid viscosity, the hole diameter of the axial air blowing hole 35 is increased, and in the case of the liquid resin 202 having a low liquid viscosity, the hole diameter of the axial air blowing hole 35 is decreased. Is set as appropriate. For example, the hole diameter of the axial air blowing hole 35 is set within a range of 0.2 mm to 1.0 mm.

  11 and 12 show cross-sectional views of the operation of the nozzle of the second embodiment as viewed from the side. FIG. 11 is a view showing a state where the liquid resin 200 is discharged from the nozzle 2 with the gate valve 5 opened. FIG. 12 is a diagram showing a state in which the gate valve 5 is closed and air blowing from the shaft center is started. Here, assuming that the resin 200 is a thermoplastic resin, a resin molding procedure by a manufacturing method to which the liquid resin supply mechanism 1 of the present invention is applied will be described below in accordance with the flowchart shown in FIG. Here, the same reference numerals represent the same functions, and the description thereof will be omitted as appropriate. When the mold 50 is opened and the nozzle 2 is advanced to a predetermined position (reference S1), the gate valve 5 is then opened by the control signal from the control circuit 9 to open the liquid resin 200 on the lower side. The liquid is discharged toward the cavity 521 (reference S2, FIG. 11). When the liquid resin 200 is quantitatively discharged into the lower cavity 521 (reference S2), the gate valve 5 is lowered by a control signal from the control circuit 9, and its tip 53 protrudes from the discharge surface 23 at the nozzle tip. The discharge surface 23 at the tip of the nozzle is closed (the gate valve 5 is closed), and the peripheral air at a predetermined temperature (symbol) is maintained to maintain the liquid state of the liquid resin 200 from the discharge surface 33 (outlet 33) of the peripheral air discharge port 3. 302) is blown out, and at the same time, axial air (reference numeral 352) at a predetermined temperature for maintaining the liquid state of the liquid resin 200 is blown out from the tip 53 of the axial center of the gate valve 5 (reference numeral S3, FIG. 12). Alternatively, the peripheral air (reference numeral 302) having a predetermined temperature for maintaining the liquid state of the liquid resin 200 is blown out from the blowout surface 33 (outlet 33) of the peripheral air blowout port 3, and after a while, the axis of the gate valve 5 Further, axial air (reference numeral 352) having a predetermined temperature that maintains the liquid state of the liquid resin 200 may be further blown out from the front end 53. According to this embodiment, the starting point of the thinned stringing resin 202 is more reliably cut off. Here, the air pressure from the axial air blowing hole 35 formed in the axial center of the gate valve 5 may be sufficient as the air pressure from the outer air blowing hole 3 is sufficient. This is because the starting point of the thread drawing resin 202 that has become sufficiently thin by the outer peripheral air 302 from the outer peripheral air outlet 3 may be cut off. The outer peripheral air 302 and the axial air 352 may have different air temperatures, or the air temperatures may be the same. Further, the outer peripheral air 302 and the axial air 352 may have different air components, or the air components may be the same component.

(Third embodiment)
FIG. 13A shows a side view showing a nozzle of the liquid resin supply mechanism of the third embodiment of the present invention, and FIG. 13B shows a cross-sectional view thereof. Here, the same reference numerals represent the same functions, and description thereof will be omitted as appropriate. The liquid resin supply mechanism 1 of this embodiment has a configuration in which the outer peripheral air outlet 3 provided in the second embodiment is omitted. This is because, depending on the properties of the liquid resin 202, it is sufficient to blow out air at a predetermined temperature that maintains the liquid state of the liquid resin 200 from the tip 53 of the axis of the gate valve 5. According to this embodiment, the nozzle 2 can be slimmed and the air piping can be simplified.

(Fourth embodiment)
A side view showing a nozzle of the liquid resin supply mechanism of the fourth embodiment of the present invention is shown in FIG. 14A, and a sectional view thereof is shown in FIG. Here, the same reference numerals represent the same functions, and description thereof will be omitted as appropriate. The liquid resin supply mechanism 1 of the present embodiment has the outer air outlet 3 in the second embodiment described above having an outer cylindrical shape arranged on the outer periphery of the nozzle, and the air outlet has a straight shape. The outer peripheral air 302 blown out from the air outlet 3 is configured to maintain the liquid state by surrounding the discharged liquid resin 200 with an air curtain. The air outlet 3 may have a trumpet shape extending downward.

  15 and 16 are sectional views of the operation of the nozzle according to the fourth embodiment as viewed from the side. FIG. 15 is a view showing a state where the liquid resin 200 is discharged from the nozzle 2 with the gate valve 5 opened. FIG. 16 is a diagram showing a state in which the gate valve 5 is closed and air blowing from the axial center is started. Here, assuming that the resin 200 is a thermoplastic resin, a resin molding procedure by a manufacturing method to which the liquid resin supply mechanism 1 of the present invention is applied will be described below in accordance with the flowchart shown in FIG. 9B. Here, the same reference numerals represent the same functions, and the description thereof will be omitted as appropriate. When the mold 50 is opened and the nozzle 2 is advanced to a predetermined position (reference S1), next, a predetermined temperature that maintains the liquid state of the liquid resin 200 from the outer peripheral air outlet 3 according to a control signal from the control circuit 9 The outer peripheral air 302 is blown out (reference S4, FIG. 15). Here, the strength of spraying the outer peripheral air 302 is maintained while the liquid resin 200 is surrounded by an air curtain by blowing out weak air while the liquid resin 202 is being supplied. In a state where the outer peripheral air 302 is blown out from the outer peripheral air outlet 3 (reference S4), the gate valve 5 is raised and the gate valve is opened by the control signal from the control circuit 9, and the liquid resin 200 is moved to the lower cavity 521. It discharges toward (reference S12, FIG. 15). The gate valve 5 may be opened at the same time as the peripheral air 302 is blown out, or the peripheral air 302 may be blown out after the gate valve 5 is opened.

  Then, when the liquid resin 200 is quantitatively discharged into the lower cavity 521 (reference S12), the gate valve 5 is lowered by a control signal from the control circuit 9, and its tip 53 is the discharge surface 23 at the nozzle tip. In addition to blowing the outer peripheral air (reference numeral 302) by closing the discharge surface 23 at the nozzle tip (closing the gate valve 5) and blowing out the outer peripheral air (reference numeral 302), a liquid resin The axial air (reference numeral 352) having a predetermined temperature that maintains the liquid state of 200 is blown out (reference numeral S4, FIG. 16). Alternatively, after the blowing of the outer peripheral air (reference numeral 302) is stopped and after a while, axial air (reference numeral 352) of a predetermined temperature that maintains the liquid state of the liquid resin 200 from the distal end 53 of the axial center of the gate valve 5 May be blown out. According to this embodiment, the liquid state is maintained by surrounding the discharged liquid resin 200 with an air curtain, and when discharge of the liquid resin 200 is completed, the starting point of the thinned stringing resin 202 is more reliably cut off. It becomes.

  As described above, the present invention is not limited to the embodiment described above. The strength of blowing the outer peripheral air 302 from the outer peripheral air outlet 3 is such that weak air is blown out while the liquid resin 202 is being supplied, so that the discharged liquid resin 200 is surrounded by an air curtain, and its liquid state and direction of discharge. Can be controlled to blow off the stringing resin by blowing stronger outer air 302 immediately after the gate valve 5 is closed. The outer peripheral air (reference numeral 302) blown from the outer peripheral air outlet 3 formed on the outer periphery of the tip of the nozzle 2 and the air (reference numeral 352) blown from the axial air outlet 35 formed in the gate valve 5 are In the control for cutting off the stringing resin, it can be controlled so as to be blown out continuously, or can be controlled so as to be blown out intermittently. Although not shown, air temperature adjusting means such as a heater and cooler, air flow path opening and closing means such as an on-off valve, and air flow rate adjusting means such as a flow control valve are appropriately provided as necessary. They may be provided in an air supply source, or may be provided separately in the middle of an air flow path such as an air pipe. Further, the axial air blowing hole 35 formed in the axial center of the gate valve 5 is additionally provided with a gate valve (not shown) that opens and closes the opening on the blowing side of the axial air blowing hole 35. It is good also as a structure which prevents a backflow. Further, the peripheral air outlet 3 may be retrofitted to the nozzle of the liquid resin supply mechanism provided in the existing compression molding machine, and the existing control circuit may be used to partially review and operate the control program. . Thus, it goes without saying that the present invention can be modified as appropriate without departing from the spirit of the present invention.

1 Liquid resin supply mechanism,
2 nozzles,
3 Outer air outlet,
35 Axis air blowout hole,
4 Temperature controller (heater, cooler),
5 Gate valve,
9 Control circuit,
50 molds,
200 resin (liquid resin),
202 resin (string drawing resin),
302 Perimeter air (air at a predetermined temperature),
352 Shaft center air (air at a predetermined temperature)

Claims (9)

  A liquid resin supply mechanism that is controlled by a control circuit and discharges the liquid resin downward from a nozzle with a built-in gate valve to supply the liquid resin to one of the molds. A liquid resin supply mechanism, characterized in that an outer peripheral air outlet that blows out outer peripheral air at a predetermined temperature to maintain the liquid state of the discharged liquid resin in a downward nozzle tip direction is disposed.   The liquid resin supply mechanism according to claim 1, wherein the air blowing port has an outer cylindrical shape arranged on an outer periphery of the nozzle, and each of the nozzle and the air blowing port has a tapered shape.   3. The liquid resin supply mechanism according to claim 1, wherein a tip of the gate valve is sharp and the tip of the gate valve protrudes from the tip of the nozzle when the discharge of the liquid resin is finished.   The axial air blowing hole is formed in the axial center of the gate valve to blow axial air at a predetermined temperature, which maintains the liquid state of the discharged liquid resin, downward from its tip. The liquid resin supply mechanism according to any one of claims 1 to 3.   A liquid resin supply mechanism which is controlled by a control circuit and discharges liquid resin downward from a nozzle having a built-in gate valve to supply the liquid resin to one of the molds. The liquid resin supply mechanism is characterized in that an axial air blowing hole for blowing axial air at a predetermined temperature, which maintains the liquid state of the discharged liquid resin, downward from its tip is formed.   6. The liquid resin supply mechanism according to claim 5, wherein a tip of the gate valve is sharp and the tip of the gate valve protrudes from the tip of the nozzle when the discharge of the liquid resin is finished.   The resin is a thermoplastic resin and the air temperature is set to be equal to or higher than the melting temperature of the thermoplastic resin, or the resin is a thermosetting resin and the thermosetting resin is heated and polymerized. The liquid resin supply mechanism according to any one of claims 1 to 6, wherein the air temperature is set to be lower than a temperature.   The stringing resin is separated from the tip of the nozzle, and dropped into one of the molds while maintaining the liquid state of the separated liquid resin. Liquid resin supply mechanism. A compression molding machine provided with the liquid resin supply mechanism according to any one of claims 1 to 8.

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