JP5576032B2 - Injection molding machine - Google Patents

Description

  The present invention relates to a molding machine, and more particularly to a structure around a nozzle that injects a plasticized resin material to a mold side.

  Conventionally, an injection molding machine basically includes an injection mechanism for plasticizing a pellet-shaped resin material and injecting it into a mold, and a mold clamping mechanism for opening and closing the mold. ing. The resin softened and melted in the injection cylinder constituting the injection mechanism is injected from the tip of the nozzle connected to the injection cylinder toward the mold after completion of the mold clamping operation.

  Regarding the temperature at the time of molding, generally, the temperature of the injection cylinder or nozzle is set to a high temperature in order to melt the resin, and the mold is cooled to about 100 to 200 compared with the nozzle or the like in order to cool the molten resin. Set to a low temperature.

  The injection operation is performed in a state where the mold clamping mechanism is clamped, that is, in a state where the nozzle and the mold are in contact. For this reason, when the nozzle and the mold come into contact with each other, the temperature of the nozzle may be lowered due to the influence of heat conduction due to the temperature difference between them.

Patent Document 1 proposes an injection molding machine for the purpose of suppressing this heat conduction. In Patent Document 1, a nozzle tip is provided at the tip of a nozzle, a tip holder is provided at a stationary platen, and the nozzle tip at the tip of the nozzle and the tip holder are brought into close contact with each other by line contact, whereby the heat at the tip of the nozzle is increased. Suppresses escape to the mold.
JP 2006-289852 A

  As described above, conventionally, the temperature of the nozzle tip decreases during mold clamping, resulting in poor resin fluidity, molding defects, and problems such as the nozzle tip being clogged with resin and becoming unmoldable. was there.

  In addition, according to the technique described in Patent Document 1, such a problem is improved to some extent, but when using a material having a narrow melting temperature range or when the temperature difference from the mold is large, The heat conduction was not sufficiently suppressed.

  In addition, heating the entire cylinder more than necessary for these measures is not preferable because it may cause a problem of drawing.

  Therefore, the present invention has been made in view of the above-described problems, and the object thereof is to suppress the heat escape of the nozzle tip portion caused by the mold clamping without heating the entire cylinder more than necessary, and more stable. An object of the present invention is to provide an injection molding machine capable of performing a molding operation.

In order to solve the above-described problems and achieve the object, an injection molding machine according to the present invention includes an injection mechanism having a nozzle for injecting a plasticized resin material into a cavity formed by a pair of molds. A mold clamping mechanism that clamps the pair of molds, and a heating unit that is disposed at a peripheral position where the nozzle is fixedly held in the mold clamping mechanism, and that heats the tip of the nozzle. A mold plate is provided between the pair of molds and the nozzle to form a flow path for flowing a resin material into the cavity. the portion disposed in the position to form a portion of the flow path of the mold plate over a portion of the flow path in the mold plate, the mold clamping mechanism is clamping the pair of molds It has a fixed platen that receives force and Fixed platen, and characterized in that the heat insulating material is provided between the receiving clamping force by the mold clamping mechanism from the heating member, the heating member interposed between said pair of molds To do.

  According to the present invention, it is possible to provide an injection molding machine capable of performing a more stable molding operation by suppressing thermal escape of the nozzle tip portion caused by mold clamping without heating the entire cylinder more than necessary. .

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a view showing a main part of an injection mechanism part in an injection molding machine according to an embodiment of the present invention. 2 and 3 are cross-sectional views at the position of the broken cross-sectional line A-A ′ in FIG. 1, as viewed from the direction of the arrows. Hereinafter, the basic configuration of the injection molding machine according to the present embodiment will be described with reference to FIGS. 1 to 3.

  The injection mechanism unit in the present embodiment includes an injection cylinder 2, an injection plunger 1, a nozzle 7, and a nozzle holder 9.

  The nut 11 and the nut 12 have a structure in which the inner surface is a female screw and can be fastened to the upper screw 20 of the injection cylinder 2. A nozzle 7 for injecting molten resin into a mold spool is attached to the tip of the injection cylinder 2.

  In the present embodiment, the injection cylinder 2 is fitted to the fixed platen upper cylindrical hole 19 of the fixed platen 8, and the nozzle tip 10 is fitted to the fitting hole 23 of the nozzle holder 9 provided in the fixed platen 8, The position is fixed and held. A nozzle holder (heating member) 9 serving as a support member that fits and supports the nozzle tip 10 with respect to the fixed platen 8 is integrally provided at a position around the nozzle 7 of the fixed platen 8. Furthermore, a holder heater 24 and a holder heater thermocouple 27 (see FIG. 4), which will be described later, are connected to the nozzle holder 9.

  Further, a heat insulating material 49 is inserted in a portion where the nozzle holder 9 and the fixed platen 8 are in contact with each other, and the heat of the nozzle holder 9 is prevented from escaping to the fixed platen 8, and the tip of the nozzle is more efficiently. 10 so that you can tell.

  1 and 2, 22 is a fixed platen parting surface, 28 is a mold, 29 is an intermediate plate, 30 is a movable plate, 35 is an ejector rod, and 43 is an ejector plate. Note that the mold 28 in the present embodiment includes a fixed-side mold plate 41, a movable-side mold plate 42 (a pair of molds), and an ejector plate 43.

  As shown in FIG. 3, the mold clamping mechanism portion in this embodiment includes a fixed platen 8, an intermediate plate 29 that holds a fixed-side mold plate 41 that is one of a pair of molds, and a movable that is the other of a pair of molds. A movable plate 30 that holds the side mold plate 42 and a mold clamping member 50 are provided. In this embodiment, the mold clamping member 50 includes a drive arm and a driven arm of a toggle mechanism that are mechanically connected to each other via a ball screw by driving a mold clamping motor (not shown) of the mold clamping member 50. In conjunction with this, the movable plate 30 to which one end of the driven arm is fixed rises toward the intermediate plate 29. Eventually, the parting surfaces of the movable side mold plate 42 and the fixed side mold plate 41 come into contact with each other, and the movable plate 30 is pressed against the fixed platen 8 with the intermediate plate 29 interposed therebetween, so that the mold clamping state is achieved.

  Next, the basic operation at the time of molding will be briefly described. In FIG. 2, the resin in the form of pellets from a hopper (not shown) is supplied to the material supply path 13 through the material charging hole 21, and the material is supplied by pushing a plunger (not shown) slidably fitted into the material supply path 13. It is sent to the inside of the injection cylinder 2 connected to the path 13. An injection plunger 1 that is slidably fitted is disposed in the injection cylinder 2. The injection plunger 1 is linearly driven in the Z-axis direction in the injection cylinder 2 by an external drive system (not shown), and is driven downward in FIG. Extrude to the side.

  Further, a band heater 6 for softening and melting the resin in the injection cylinder 2 is wound around the outer surface of the injection cylinder 2, and this and the thermocouple 25 allow the injection cylinder 2 to have a predetermined temperature according to the material. Controlled. A torpedo 14 for separating the resin is provided inside the injection cylinder 2.

  Therefore, the resin in the injection cylinder 2 passes through the third resin flow path 18 from the first resin flow path 16 formed between the injection cylinder 2 and the torpedo 14 by driving the injection plunger 1, It is sent to the nozzle 7 while being softened and melted by the heater 6.

  A nozzle heater 15 is also provided on the outer periphery of the nozzle 7 to further promote and maintain the plastic state of the resin. The injection cylinder 2, the nozzle 7, and the heaters are unitized, and can be attached and detached by removing the cylinder holders 44 and 45.

  In the center of the nozzle holder 9, a fitting hole 23 is provided in which the nozzle tip 10 is fitted and positioned. The opening hole on the other surface of the nozzle holder 9 opens to the formation flow path of the runner 32 formed in the stationary side template 41 (see FIG. 4).

  The molten resin injected from the nozzle tip 10 forms a runner 32 in the flow path of the fixed-side mold plate 41, and puts the molded product 33 in the cavity formed by the fixed-side mold plate 41 and the movable-side mold plate 42. Form. The molded product 33 is taken out of the mold by the ejector pin 34 when the mold is opened, and the runner 32 is discharged to complete a series of molding operations.

  Next, a configuration around the nozzle 7 which is a characteristic part of the present embodiment will be described. FIG. 4 is an enlarged view of the periphery of the nozzle 7 in the present embodiment, showing the structure of the nozzle 7 and the nozzle holder 9 in detail, and showing the state at the time of mold clamping. FIG. 5 is a three-dimensional perspective view of the cross-sectional portion of FIG.

  As described above, when there is a temperature difference between the injection part and the mold, when the nozzles 7 come into contact with each other during the injection operation, thermal escape of the nozzle 7 may occur, causing problems such as nozzle clogging.

  In particular, in the case of a small injection molding machine, for example, in the case of an injection molding machine in which overall miniaturization is planned by a configuration such as fixing the injection cylinder 2 to the fixed platen 8 as in this embodiment, the injection cylinder 2 is used. The size of the nozzle 7 is also reduced in size accordingly. Therefore, when the mold comes into contact with the fixed platen 8, heat escape to the mold is relatively likely to occur. Therefore, in order to suppress the temperature drop of the nozzle holder 9 and the nozzle 7, the temperature control by providing the holder heater 24 on the nozzle holder 9 that the nozzle 7 contacts is performed in a small injection molding machine like this embodiment. It can be said that it is more effective.

  FIG. 6 is a three-dimensional view showing the internal configuration of the nozzle holder 9 in the present embodiment. In the nozzle holder 9, two holder heaters 24 in the present embodiment as heating means are incorporated, and a holder heater thermocouple 27 in the present embodiment as detection means is fixed by a fixed plug 48.

  Although two holder heaters 24 are provided in the present embodiment, one holder may be provided or three or more holder heaters 24 may be provided as necessary. Moreover, although the holder heater 24 was described using a rod-shaped one, for example, a coil-shaped one may be used, and the shape and heating method are not limited.

  The nozzle holder 9 has a structure in which the holder heater thermocouple 27 can be inserted to the vicinity of the nozzle tip 10, and temperature measurement close to the nozzle tip 10 can be performed. The holder heater thermocouple 27 is detachably attached by a fixed plug 48. The fixed platen 8 is formed with a fixed platen wiring escape groove 40 (see FIG. 5) for passing the temperature adjusting wiring.

  The wiring of the holder heater 24 and the holder heater thermocouple 27 is fixed by the nozzle holder wiring retainer 31 and the wiring retainer bolt 38 (see FIG. 5), and prevents disconnection due to the cable being caught during mold clamping. In addition, it is considered not to interfere with the mold during mold clamping.

  FIG. 7 shows a three-dimensional view of the temperature adjustment unit including the nozzle holder 9, the holder heater 24, and the holder heater thermocouple 27. The holder heater 24 is connected to an electrical component of the injection molding machine by a heater connector 36 and a thermocouple connector 37. By attaching and detaching these connectors, the temperature adjustment unit can be easily disconnected from the electrical component. Therefore, maintenance and replacement of each part becomes easy. In FIG. 7, reference numeral 47 denotes a holder heater thermocouple wiring.

  FIG. 8 is a three-dimensional view of the nozzle holder wiring presser 31. The nozzle holder wiring retainer 31 is formed with a groove in the center so that the wiring can escape. The shape is not limited as long as the function of the wiring retainer is satisfied.

  FIG. 9 is a view of the nozzle holder 9 viewed from obliquely below with the mold removed, and shows a connection state of the holder heater 24 and the holder heater thermocouple 27 to the nozzle holder 9. Using the fixed platen wiring escape groove, the holder heater wiring 46 and the holder heater thermocouple 27 are drawn out of the molding machine. Various wirings are fixed and protected by a nozzle holder wiring retainer 31 and fastened by a wiring retainer bolt 38. The nozzle holder 9 is fastened to the fixed platen 8 by a nozzle holder mounting bolt 39.

  FIG. 10 is a view showing a method of disassembling and assembling a series of temperature adjustment units such as the holder heater 24 and the holder heater thermocouple 27 of the nozzle holder 9. In disassembling the temperature adjustment unit of the nozzle holder 9, first, the connectors described in FIG. 7 are removed and separated from the electrical component. Next, the wiring retainer bolt 38 and the nozzle holder wiring retainer 31 are removed, the nozzle holder mounting bolt 39 is loosened and removed, and can be removed (detached) to the outside. The assembly may be performed in the reverse order of the disassembly order.

  The injection molding machine has a control device (not shown) for driving and controlling the CPU, a CPU for arithmetic processing, a ROM for storing the control program and arithmetic data for the injection molding machine, and a temporary storage for the control program and arithmetic data. It includes a RAM and the like used for the above. In the present embodiment, the control device performs heating control based on the detected temperature (detection result) of the nozzle holder 9 detected by the holder heater thermocouple 27 so that the holder heater 24 is continuously heated to a constant temperature during the mold clamping operation. (Heating operation).

  As described above, the nozzle 7 is heated at the portion where the nozzle 7 comes into contact with the fixed-side mold plate 41 of the mold and the nozzle holder 9 is heated and controlled by the heater. Heat transfer to the mold can be suppressed. Further, since it is not necessary to change the temperature control necessary for the role of the nozzle 7 and the mold, the temperature control for suppressing the heat escape of the nozzle 7 becomes easy.

  Further, by controlling the heating of the nozzle holder 9 in this way, the fitting hole 23 of the nozzle holder 9 into which the nozzle tip 10 is fitted closely contacts the side surface of the nozzle tip 10 due to thermal expansion. Thus, the gap between the fitting hole 23 and the nozzle tip portion 10 is sealed, and the resin leakage that may occur due to this gap can be prevented.

  Furthermore, you may provide between the nozzle holder 9 and the stationary-side template 41 the heat insulating material which is not illustrated avoiding the runner formation path. By sandwiching the heat insulating material in this manner, the heat transfer between the nozzle holder 9 and the mold can be more appropriately adjusted even by the configuration in which the nozzle holder 9 is heated to prevent the nozzle tip 10 from being clogged. .

  In addition, about the structure of a drive with a nozzle part and a metal mold | die, in this embodiment, the nozzle 7 was demonstrated as a structure fixed with respect to the stationary platen 8 via the supporting member (heating member). However, the present invention is not limited to this embodiment, and the present invention can also be applied to an injection molding machine having an injection mechanism section and a mold clamping mechanism section in which the nozzle moves relative to the fixed platen. That is, the configuration in which the nozzle is movable with respect to the fixed platen has the same configuration in which the fixed platen and the tip of the nozzle are in contact with the mold during mold clamping. Therefore, the injection molding machine having such a configuration can also be implemented by providing a member as a support member on a stationary platen and providing a heating means there as in the present embodiment.

  In the present embodiment, the nozzle holder is described as the support member that comes into contact with the nozzle. However, the present invention is not limited to this. For example, the case where the temperature of a locating ring of a mold is controlled is also included in the scope of the present invention.

  In addition, the injection molding machine main body has been described using a vertical molding machine adopting a plunger injection system in this embodiment, but the injection system can also be implemented by an in-line screw system or a pre-plunger system. The main body may be a horizontal type.

  As described above, according to the above-described embodiment, heat escape from the nozzle tip portion caused by mold clamping can be suppressed by heating the nozzle tip. In addition, since the heater is provided on the support member that contacts the nozzle tip, only the nozzle tip is heated to prevent problems such as dragging due to overheating of the nozzle, and an injection molding machine that can perform more stable molding operations. Can be provided.

It is a three-dimensional view of the principal part of the injection mechanism part of the injection molding machine concerning one Embodiment of this invention. FIG. 2 is a cross-sectional view taken along the line A-A ′ of the radial center position of the injection plunger in FIG. 1. FIG. 2 is a peripheral view of a mold clamping mechanism showing a state when the mold in FIG. 1 is open. FIG. 3 is an enlarged view around the nozzle of FIG. 2. FIG. 5 is a three-dimensional view of FIG. 4. It is detail drawing of a nozzle holder, and is a figure which shows the connection state of a thermocouple and a heater. It is a three-dimensional view of a nozzle holder temperature control unit. It is a three-dimensional figure of the part which suppresses the wiring of a nozzle holder temperature control unit. It is a figure which shows the connection state seen from diagonally downward in the state which removed the metal mold | die. It is a three-dimensional view of the assembly and disassembly of a nozzle holder temperature control unit.

Explanation of symbols

2 Injection cylinder 6 Band heater 7 Nozzle 8 Fixed platen 9 Nozzle holder 10 Nozzle tip 15 Nozzle heater 19 Fixed platen upper cylindrical hole 20 Injection cylinder upper screw 22 Fixed platen parting surface 24 Holder heater 27 Thermocouple for holder heater 28 Mold 29 Intermediate plate DESCRIPTION OF SYMBOLS 30 Movable plate 31 Nozzle holder wiring retainer 32 Runner 33 Molded product 34 Ejector pin 35 Ejector rod 36 Heater connector 37 Thermocouple connector 38 Wiring retainer bolt 39 Nozzle holder mounting bolt 40 Fixed platen wiring escape groove 41 Fixed side template 42 Movable side Mold plate 43 Ejector plate 44 Cylinder retainer 45 Cylinder retainer 46 Holder heater wiring 47 Holder heater thermocouple wiring 48 Fixed plug 49 Heat insulation plate 50 Mold clamping Member

Claims (4)

An injection mechanism having a nozzle for injecting a plasticized resin material into a cavity formed by a pair of molds;
A mold clamping mechanism for clamping the pair of molds;
A heating member that is disposed at a peripheral position where the nozzle is fixedly held in the mold-clamping mechanism unit and has a heating unit that heats the tip of the nozzle;
A mold plate is provided between the pair of molds and the nozzle to form a flow path for flowing a resin material into the cavity.
Forming a part of the flow path of the template by covering a part of the flow path in the template with a portion of the heating member disposed at a position around the nozzle ;
The mold clamping mechanism has a fixed platen that receives a mold clamping force of the pair of molds,
The fixed platen receives a clamping force by the clamping mechanism from the heating member interposed between the pair of molds, and a heat insulating material is provided between the heating member and the heating member. > An injection molding machine characterized by that.   The injection molding machine according to claim 1, further comprising a control unit that controls a heating operation of the heating unit based on a detection result of a detection unit that detects a temperature of the heating member.   2. The heating member is integrally attached to a fixed platen of the mold clamping mechanism, and the nozzle is fixedly held to the fixed platen via the heating member. Or the injection molding machine of 2.   The injection molding machine according to claim 2, wherein the heating member, the heating unit, and the detection unit are detachably disposed with respect to a fixed platen of the mold clamping mechanism.

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