JP2013216057A - Purge cover device of injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a purge cover device of an inexpensive injection molding machine, capable of plasticizing an injection material for a purge at high back pressure and capable of injection at high speed.SOLUTION: A purge cover device of an injection molding machine is comprised of a cover plate 2 which covers an injection nozzle (SN), a shielding plate (8) which closes a through-hole formed in a fixed platen (KB), and a guidance plate (11) which guides a purge material injected from an injection unit (SU). The shielding plate (8) takes an operation position and a non-operation position, the shieleding plate (8) is formed with a nozzle plug part (9) which closes a nozzle hole when the same is in the operation position, and if the injection unit (SU) moves back when the shielding plate (8) is in the operation position, the guidance plate (11) is interlocked and driven to the operation position for guiding the purge material.

Description

  The present invention relates to a purge cover device for an injection molding machine, which is applied between an injection unit and a mold clamping unit, and more specifically, is attached to the mold clamping unit side between the injection unit and the mold clamping unit. The present invention relates to a purge cover device.

  The injection molding machine is generally composed of an injection unit and a mold clamping unit as is well known in the art. The injection unit is composed of a heating cylinder, a screw or the like provided inside the heating cylinder so as to be driven in the rotational direction and the axial direction, and a heating band heater is provided on the outer periphery of the heating cylinder. Is equipped with an injection nozzle. On the other hand, the mold clamping unit includes a fixed mold attached to the fixed platen, a movable mold attached to the movable platen, and a mold clamping device for clamping the movable mold to the fixed mold. It is configured. Therefore, an injection molded product can be obtained as follows. That is, the injection material is supplied to one end of the heating cylinder and the screw is driven to rotate. Then, the injection material is melted by heat applied from the band heater, frictional heat generated when the screw is rotationally driven, shearing heat, and the like in the process of being sent forward, and accumulated in the measuring chamber in front of the heating cylinder. At this time, the screw is retracted by the pressure of the accumulated injection material or by sucking back. When the weighing is finished, the screw is driven in the axial direction and the mold is clamped to inject and fill the cavity formed between the fixed side mold and the movable side mold. After cooling and solidifying, the movable mold is opened to obtain a molded product.

  By the way, as understood from the above description, when the molding is interrupted, the molten injection material remains in the heating cylinder. Since the remaining injection material may be deteriorated by heat or the like, the molding cannot be resumed as it is. Also, when trying to obtain a molded product from an injection material with different materials, colors, properties, etc., the injection material so far remains in the heating cylinder, so molding starts as it is. I can't do it. Therefore, prior to the main molding, the old injection material remaining in the heating cylinder, between the flights of the screw, the injection nozzle hole and the like is purged as follows. That is, the injection unit is retracted, and the injection nozzle is separated from the locating ring of the fixed mold. Then, the screw is rotationally driven in the plasticizing direction without supplying the injection material. At this time, the screw is sucked back to suppress an increase in the pressure in the measuring chamber so that the injection material does not leak from the injection nozzle. Then, the old injection material remaining between the inner peripheral wall of the heating cylinder and between the flights of the screw is sent to the measuring chamber. The screw is driven in the axial direction to discharge the old injection material from the injection nozzle. This is repeated one to several times to complete the purge. Alternatively, the purge material is plasticized and similarly discharged from the injection nozzle and purged.

  When purging as described above, various proposals have been made for a cover for preventing the purge material from splashing around, a device for increasing the back pressure when plasticizing, and the like. Patent documents 1 and 2 are mentioned as literature.

Japanese Utility Model Publication No. 60-187015 Japanese Patent Application Laid-Open No. 07-227879

  Patent Document 1 discloses a cover for preventing the purge resin from scattering. This cover takes a position covering the injection nozzle and a position retracted from this position. A guide plate is provided at a position facing the injection nozzle to guide the injected purge resin to the lower tray. On the other hand, Patent Document 2 discloses a nozzle sealing device including a nozzle sealing body and a nozzle wiper that wipes the tip of an injection nozzle. The nozzle sealing device is driven by a robot to a position where the nozzle sealing body aligns with the injection nozzle and a position where the nozzle sealing body retracts.

  Since the cover described in Patent Document 1 can be driven to a position that covers the injection nozzle, the cover resin can be safely injected and discharged by covering with the cover. In particular, since the cover is provided, it is recognized that the resin remaining in the head of the heating cylinder and the injection nozzle hole can be purged by injecting at a high speed. However, in order to sufficiently replace the resin to every corner of the screw, it is necessary to rotate the screw while increasing the resin density by applying a back pressure to the screw. Since no special means for blocking the injection nozzle hole is provided, a high back pressure cannot be applied, and the purge resin cannot be sufficiently replaced.

  On the other hand, according to the invention described in Patent Document 2, since the nozzle sealing body is provided, it can be sufficiently replaced by applying a high back pressure. However, since there is no cover, the injection speed cannot be increased to sufficiently purge the resin remaining in the head and the injection nozzle hole in the heating cylinder. Moreover, since the nozzle sealing device composed of the nozzle sealing body and the nozzle wiper is carried in and out between the mold clamping unit and the injection unit by the robot, an expensive robot must be added. There is a problem. Furthermore, a robot or actuator must be provided with a safety fence for ensuring the safety of workers, and there is a problem that power consumption increases as the number of actuators increases.

  Accordingly, an object of the present invention is to provide a purge cover device for an injection molding machine that can plasticize the purge material with a high back pressure and can inject at a high speed. Another object of the present invention is to provide a purge cover device for an injection molding machine that has a simple structure and is inexpensive and can be easily attached to an existing injection molding machine.

  In order to achieve the above object, the present invention includes a cover plate, a shielding plate, and a guide plate. These are attached to the mold clamping unit side between the injection unit and the mold clamping unit. The cover plate closes the through hole formed in the fixed plate of the mold clamping unit so that the cover plate takes an operating position that covers the upper part of the injection nozzle of the injection unit and a retracted position that retreats from the operating position. An operating position and a retracting position for retracting from the operating position are adopted. The shielding plate is formed with a nozzle plug portion that closes the nozzle hole when the injection nozzle is touched when the shielding plate is in the operating position, and the guide plate is purged when the injection unit is retracted when the shielding plate is in the operating position. It is comprised so that it may drive to the operation position which guide | induces to a predetermined direction.

  That is, in order to achieve the above object, the invention according to claim 1 is an injection molding machine including an injection unit and a mold clamping unit, and the mold clamping unit between the injection unit and the mold clamping unit. A purge cover device attached to the side, wherein the purge cover device has an operating position that covers an upper portion of the injection nozzle of the injection unit and a retracted position that retracts from the operating position; and the mold clamping unit An operating position that closes the through hole formed in the fixed plate, a shielding plate that takes a retracted position that retracts from the operating position, and a guide plate that guides the purge material injected from the injection unit in a predetermined direction, The shield plate is formed with a nozzle plug portion that closes the nozzle hole when the injection nozzle of the injection unit is touched when the shield plate is in the operating position. The plate is configured to be driven in conjunction with an operating position for guiding the purge material when the injection unit is retracted when the shielding plate is in the operating position, and the invention according to claim 2, In the apparatus according to 1, the cover plate and the shielding plate are configured to be integrated and take an operating position and a retracted position.

  The invention described in claim 3 is a purge cover device attached to the mold clamping unit side between the injection unit and the mold clamping unit in an injection molding machine including an injection unit and a mold clamping unit. The purge cover device includes a cover plate that covers an upper portion of the injection nozzle of the injection unit, an operation position that closes a through hole formed in a stationary platen of the mold clamping unit, and a retreat position that retreats from the operation position. And a guide plate that guides the purge material ejected from the injection unit in a predetermined direction. When the shield plate is in the operating position, the injection nozzle of the injection unit touches the shield plate. A nozzle plug for closing the nozzle hole is formed, and the guide plate is purged when the injection unit is retracted when the shielding plate is in the operating position. Configured to be driven in conjunction to the operating position to induce. According to a fourth aspect of the present invention, in the apparatus according to any one of the first to third aspects, the guide plate is independent of the cover plate and the shielding plate, and is retracted from the operation position. The invention according to claim 5 is the apparatus according to any one of claims 1 to 4, wherein the cover plate and the shielding plate are attached to a substrate, and the substrate is It is configured to be attached to a fixed plate of the mold clamping unit.

  As described above, according to the present invention, since the purge cover device is attached to the mold clamping unit side, the robot for carrying in the working position between the injection unit and the mold clamping unit or carrying it out to the retreat position. Such a drive device is not required. Therefore, it is inexpensive and does not require a running cost. Moreover, since it is attached to the mold clamping unit side, it can be easily applied to an existing injection molding machine.

  According to the present invention, since the nozzle plug portion is formed on the shielding plate, the purge material can be plasticized with a high back pressure. Therefore, the effect that the resin can be sufficiently exchanged to every corner of the screw can be obtained. At the same time, since a cover plate covering the upper part of the injection nozzle is provided, and when the injection unit is retracted, the guide plate is driven to the operating position, so the purge material can be injected or discharged at high speed, Does not pollute the surrounding environment. Therefore, it is possible to efficiently purge the resin remaining in the head of the heating cylinder and the injection nozzle hole. Furthermore, since the cover plate, the shielding plate, and the guide plate can take a retracted position, an effect that normal mass-production molding can be performed without removing the purge cover device from the mold clamping unit is also obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the 1st Embodiment of this invention in a use condition, The (a) is the state which has plasticized the purge material, The (a) is sectional drawing which shows the detail of the principal part, respectively. It is sectional drawing which shows the purge cover apparatus which concerns on the 1st Embodiment of this invention in the state which has a guidance plate in an operation position. It is sectional drawing shown in the state when the purge cover apparatus which concerns on the 1st Embodiment of this invention is evacuated and normal mass production molding is carried out. It is a figure which shows the purge cover apparatus which concerns on other embodiment of this invention, The (a) is sectional drawing which shows 2nd Embodiment in the state which has a guidance plate in a retracted position, The (a) is It is sectional drawing which shows 3rd Embodiment in the state which has a guidance plate in a retracted position similarly. It is a perspective view which shows the 4th Embodiment of this invention typically.

  First, a first embodiment of the present invention will be described. FIG. 1 shows a part of the injection unit SU and the mold clamping unit KU. The injection unit SU includes a heating cylinder KC having a conventionally known form. The outer periphery of the heating cylinder KC is covered with a heater cover HC, and an injection nozzle SN is attached to the left front in FIG. Such an injection unit SU is driven in the axial direction between the position where the injection nozzle SN touches the locating ring of the fixed mold and the position where the injection nozzle SN retracts. The mold clamping unit KU also includes a fixed platen KB having a conventionally known form. A funnel-shaped through hole TK is formed in the fixed platen KB, and a fixed mold is attached to the fixed plate KB so as to be aligned with the through hole TK, although not shown in the drawing. The injection unit SU and the mold clamping unit KU configured as described above are conventionally well-known and existing units, but the purge cover device 1 according to the present embodiment is low in the existing injection molding machine. It can be easily installed at a low cost.

  The purge cover device 1 according to the first embodiment includes a cover plate 2 and a shielding plate 8 having a substantially flat plate shape. The cover plate 2 is composed of a flat plate-like upper surface portion and a side surface portion connected to both edges of the upper surface portion and lowered downward by a predetermined length so that the injected material does not scatter upward and left and right during purging. In FIG. 1, only the upper surface portion is shown. The base ends of the cover plate 2 and the shielding plate 8 are attached to the rotating boss 3 at substantially right angles through the arms 4 and 5 as shown in the detailed view of FIG. . The rotating boss 3 is rotatably attached to the substrate 6, and this substrate 6 is attached to the side surface of the fixed platen KB by bolts 7 and 7. Alternatively, it can be detachably attached. Therefore, the cover plate 2 and the shielding plate 8 are rotated while maintaining a substantially right-angled posture, and as shown in FIG. 1, the operating position where the shielding plate 8 closes the through hole TK of the stationary platen KB, and the transparent position. A non-actuated position or a retracted position away from the hole TK can be taken. When the shielding plate 8 is driven to the operating position, a recess is formed at a position aligned with the injection nozzle SN. This recess serves as a nozzle plug 9 that closes the nozzle hole when the injection nozzle NS is touched.

  The cover plate 2 is provided with a guide device 10 that guides the purge material scattered from the injection nozzle SN downward. The induction device 10 includes an induction plate 11 formed in a semi-cylindrical shape curved from a material having a small friction coefficient such as stainless steel (registered trademark) or PTFE (polytetrafluoroethylene), and the induction plate 11. It consists of a coil spring 12 held in the retracted position and a wire 16 for driving to the operating position. A cylindrical guide member 13 is attached to the upper surface of the cover plate 2 in a substantially vertical direction with respect to the cover plate 2. An operating rod 14 is inserted into the guide member 13 so as to be movable up and down, and a guide plate 11 is attached to the tip of the lower side of the cover 2. Further, the operating rod 14 extends upward from the guide member 13, and a spring receiver 15 is provided at the tip thereof. The coil spring 12 is attached in a slightly compressed state between the upper end portion of the guide member 13 and the lower surface of the spring receiver 15. That is, due to the restoring force of the coil spring 12, the actuating rod 14, and thus the guide plate 11, is pulled up to the upper retracted position.

  The starting end portion of the wire 16 is attached to the lower end portion of the guide plate 11 as shown in FIG. On the other hand, a guide ring 17 is attached to the lower end of the shielding plate 8, and a hook hook 18 is provided below the tip of the cylinder cover CC. The wire 16 is guided by a guide ring 17, and a hook 19 at the tip thereof is detachably hooked on a hook hook 18.

  Next, the operation of the first embodiment will be described. The substrate 6 on which the shielding plate 2 and the cover plate 8 are assembled is attached to the side surface of the fixed plate KB with, for example, bolts 7 and 7. Thereby, even an existing injection molding machine can be easily attached.

  When purging for color change or material change, the injection unit SU is retracted by a predetermined amount, and this time, the purge cover device 1 is rotated approximately 90 degrees in the clockwise direction of the clockwise hand from the molding position or the retracted position. Then, the shielding plate 8 closes the through hole TK of the stationary platen KB, and the cover plate 2 covers the upper periphery of the injection nozzle SN. The injection unit SU is advanced, and the nozzle SN is touched to the nozzle plug portion 9 of the shielding plate 2. Or press. Such a state is shown in FIG. As it is pressed, a high back pressure is applied to plasticize the purge material. Since it is plasticized with a high back pressure, the resin can be fully exchanged to every corner of the screw.

  Next, the injection or discharge is performed. However, since the guide plate 11 is independent from the shielding plate 8, the discharge can be performed simply by retracting the injection unit SU and separating the injection nozzle SN from the nozzle plug portion 9. However, before the injection unit SU is retracted, the hook 19 at the tip of the wire 16 is hooked on the hook hook 18 of the heater cover HC, and then the injection unit SU is retracted. Then, the injection nozzle SN is separated from the nozzle plug portion 9 and the guide plate 11 is pulled down to the position facing the injection nozzle SN against the coil spring 12 by the wire 16. The lowered state is shown in FIG. There it is injected. This time, the purge material mainly hits the guide plate 11 and is guided to a receiving container (not shown) below. By increasing the injection speed, the resin remaining in the head and the injection nozzle hole of the heating cylinder KC can be sufficiently discharged.

  When obtaining a molded product by mass production, the hook 19 of the wire 16 is removed and the injection unit SU is moved backward. Then, holding the cover 2 or the shielding plate 8 and rotating it 90 degrees in the counterclockwise direction in FIG. If it does so, the shielding board 2, the cover board 8, the induction | guidance | derivation plate 11, etc. will be in the state shown by FIG. As is clear from FIG. 3, neither the injection unit SU nor the mold clamping unit KU is obstructed by the purge cover device 1. That is, the purge cover device 1 can be retracted only by rotating it approximately 90 degrees. As is well known in the art, the screw is rotated to measure the injection material, the injection nozzle SN is touched to the locating ring of the fixed mold, and the screw is driven in the axial direction to the mold clamping unit KU. Injection filling into the configured cavity. After waiting for cooling and solidification, the molded product is taken out from the mold clamping unit KU. Thereafter, molding is performed in the same manner.

  The main parts of the second and third embodiments of the present invention are shown in FIGS. In the first embodiment, the guide member 13 is attached in a substantially vertical direction with respect to the cover plate 2, but in the second embodiment, as shown in FIG. They are provided substantially in parallel. Similar components will not be described with the same reference number or the same reference number with a dash “′”, but the starting end of the wire 16 ′ is attached to the end of the actuating rod 14 ′, and the end is a guide pulley. It is attached to the induction plate 11 via 21, 22 or the like. Although not shown in FIG. 4, since the wire 16 extends from the induction plate 11 so as to be detachably attached to the heater cover HC, it operates in substantially the same manner as in the first embodiment.

  In the third embodiment shown in FIG. 4A, there is no actuating rod (14), and one end of the coil spring 12 'is fixed to the upper surface of the cover plate 2. The other end of the coil spring 12 'is attached to the start end of the wire 16', and the end is attached to the guide plate 11 via the guide pulleys 21, 22 and the like. The direction of the restoring force of the coil spring 12 'is substantially the same as that of the first and second embodiments except that the direction of the restoring force is different from that of the first and second embodiments.

  In the first to third embodiments, the shielding plate 2 and the cover 8 are integrated in the rotary boss 5 to take the operating position and the retracted position. However, the cover is fixed and the shielding plate and FIG. 5 shows a fourth embodiment in which the guide plate takes an operating position and a retracted position independently of each other. The same reference numerals are given to the same elements as the constituent elements of the first to third embodiments, and the same reference numerals are given the same reference numerals with a dash “′”, and the description will not be repeated. According to the present embodiment, the cover plate 2 'is fixed to the substrate 6'. The shielding plate 8 ′ and the guide plate 11 ′ are rotatably provided on a fixed rod 30 that is fixedly provided on the substrate 6 ′. In other words, the fixed rod 30 is provided with a pair of rotating arms 31 and 31, and a shielding plate 8 'is attached to the tip of these rotating arms. Although the shielding plate 8 'shown in FIG. 5 is in the operating position, when it is driven upward from this operating position by manual operation and temporarily fixed to the lower surface of the cover plate 2' or the like, the retracting position is taken. Can be done. The guide plate 11 ′ is also rotatably provided on the fixed rod 30 via the rotation arm 32. The rotating arm 32 is biased to a retracted position by a plate-like spiral spring 33. A starting end of a wire 16 ′ is attached to the lower side of the rotating arm, and the wire 16 ′ is attached to the injection unit via a guide pulley 34. Therefore, when the injection unit moves backward, the guide plate 11 'is driven in conjunction with the operating position. The fourth embodiment operates in substantially the same manner.

  The purge cover device according to the present embodiment can be directly applied to a metal injection molding machine having a low melting point.

SU injection unit KU mold clamping unit SN injection nozzle HC heater cover 1, 1 'purge cover device 2, 2' cover plate 6, 6 'substrate 8, 8' shielding plate 11, 11 'induction plate 12, 12' coil spring 14 Actuating rod 16, 16 'Wire 19 Hook

Claims (5)

In an injection molding machine including an injection unit and a mold clamping unit, a purge cover device attached to the mold clamping unit side between the injection unit and the mold clamping unit,
The purge cover device includes a cover plate that takes an operating position that covers an upper portion of the injection nozzle of the injection unit and a retracted position that retreats from the operating position, and a through hole formed in the stationary platen of the mold clamping unit. A shielding plate that takes an operating position to close and a retracting position to retract from the operating position, and a guide plate that guides the purge material injected from the injection unit in a predetermined direction,
The shielding plate is formed with a nozzle plug portion that closes the nozzle hole when the injection nozzle of the injection unit is touched when the shielding plate is in the operating position.
The guide plate is driven in conjunction with an operating position for guiding the purge material when the injection unit is retracted when the shielding plate is in the operating position. Purge cover device. 2. The purge cover device of an injection molding machine according to claim 1, wherein the cover plate and the shielding plate are integrated to take an operating position and a retracted position. In an injection molding machine including an injection unit and a mold clamping unit, a purge cover device attached to the mold clamping unit side between the injection unit and the mold clamping unit,
The purge cover device includes a cover plate that covers an upper portion of the injection nozzle of the injection unit, an operation position that closes a through hole formed in a fixed plate of the mold clamping unit, and a retreat position that retreats from the operation position. A shielding plate to be taken, and a guide plate for guiding the purge material injected from the injection unit in a predetermined direction,
The shielding plate is formed with a nozzle plug portion that closes the nozzle hole when the injection nozzle of the injection unit is touched when the shielding plate is in the operating position.
The purge of the injection molding machine, wherein the guide plate is driven in conjunction with the operating position for guiding the purge material when the injection unit is retracted when the shielding plate is in the operating position. Cover device. The apparatus according to any one of claims 1 to 3, wherein the guide plate adopts an operating position and a retracted position for retracting from the operating position independently of the cover plate and the shielding plate. Purge cover device for injection molding machine. 5. The purge cover device of an injection molding machine according to claim 1, wherein the cover plate and the shielding plate are attached to a substrate, and the substrate is attached to a fixed plate of the mold clamping unit. .

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