JP4414840B2 - Molding machine - Google Patents

Description

  The present invention relates to a pre-plastic injection molding machine having a screw for kneading and plasticizing resin raw materials and an injection plunger for injecting and filling molten resin into a mold.

  FIG. 3 is a diagram showing a configuration of a conventional pre-plastic injection molding machine. In FIG. 3, 51 is an injection cylinder composed of a front heating cylinder 52 and a rear heating cylinder 53, 54 is an injection nozzle fixed to the front end side of the front heating cylinder 52, and 55 is inside the rear heating cylinder 53. An injection plunger arranged so as to be able to move forward and backward, 56 is a hydraulic cylinder that is a forward and backward drive source of the injection plunger 55, 57 is a plasticizing cylinder that is a heating cylinder, and 58 is rotated into the plasticizing cylinder 57 A screw that is arranged so as to be capable of being rotated by a hydraulic motor (not shown), 59 is a connecting block that connects the injection cylinder 51 and the plasticizing cylinder 57, and 57 a is on the tip side of the plasticizing cylinder 57. The formed resin supply passage 59a is formed in the connecting block 59 and communicates with the resin supply passage 57a. A resin supply passage 53a formed in the front heating cylinder 52 of the 51 and communicated with the resin supply passage 59a is formed in the rear heating cylinder 53 of the injection cylinder 51 so that the injection plunger 55 can move forward and backward. 52a, a plunger forward / reverse space communicating with 52a, 52b is formed in the front heating cylinder 52 of the injection cylinder 51, a resin injection passage communicating with the plunger forward / reverse space 53a, 54a is formed in the injection nozzle 54a, This is a resin injection passage communicating with the resin injection passage 52b.

  In the configuration shown in FIG. 3, the resin raw material supplied to the rear side (the rear side of the screw 58) in the plasticizing cylinder 57 is melted by frictional heat generated by the rotation of the screw 58 and external heating from the plasticizing cylinder 57. It is kneaded and plasticized while being transferred forward by a screw feed action by screw rotation, and the molten resin is injected from the tip end side of the screw 58 through the resin supply passages 57a, 59a, 52a. The plunger 55 is fed to the tip side. Accordingly, when the injection plunger 55 moves backward while controlling the back pressure and a predetermined amount of molten resin is stored in front of the injection plunger 55 (in the plunger forward / rearward movement space 53a), the screw 58 rotates. Stopped. Thereafter, when the injection start timing is reached, the injection plunger 55 is rapidly driven forward, so that the molten resin stored in the plunger forward / rearward movement space 53a passes through the resin injection passages 52b and 54a. It is designed to be injected and filled into the mold cavity.

  In the conventional pre-plastic injection molding machine having the configuration as shown in FIG. 3, the resin supply passages 59a and 52a from the distal end side of the screw 58 to the distal end side of the injection plunger 55 are bent, The formation of the resin supply passages 59a and 52a is a cumbersome and time-consuming process, and the total length of the resin supply passages 57a, 59a, and 52a tends to be long, and the resin supply passages 59a and 52a are bent. In combination with this, there is a problem that the resin stays more and the pressure loss during the metering process cannot be ignored. In addition, since the resin supply passages 57a, 59a, and 52a are formed in separate members, the number of parts is increased, and there is a problem that resin leakage is likely to occur from a connection part between the parts. Furthermore, since the outer shape of the connecting block 59 is provided, and the outer shape of the part forming the resin supply passage for measurement in this way has a place where it is difficult to attach the band heater, the band heater There is also a problem that it is difficult to arrange the devices so that suitable temperature control can be performed.

  The present invention has been made in view of the above points, and the object of the present invention is to simplify the shape of the resin supply passage from the tip end side of the screw to the tip end side of the injection plunger in the pre-plastic injection molding machine. It is to facilitate processing and reduce the number of parts.

Since the present invention is to achieve the above object, a screw for kneading and plasticizing the resin material, the pre-plasticization type injection molding machine having an injection plunger for injecting and filling the molten resin into the mold, the The screw and the injection plunger are arranged in parallel, and the holding block is arranged so that the injection plunger can be moved forward and backward, and is arranged so as to be rotatable in the plasticizing cylinder. with a built-in tip of the screw, the resin supply passage for feeding the molten resin fed out from the tip of the screw to the tip of the injection plunger, the axial center line of the screw and the injection plunger and obliquely intersect Further, the holding block is formed in a straight line .
Further, the outer periphery of the holding block has a shape in which a circle and an oval shape are combined, and a band heater is wound around the circular outer periphery and the oval outer periphery of the holding block.
Further , the drive source for the linear motion of the injection plunger is a rotary servo motor.
The linear motion drive source of the injection plunger is a linear motor, and the linear motor includes a stator around which a winding is wound and a mover that linearly moves with respect to the stator. The stator has a plurality of facing portions where the magnetic pole teeth are opposed to each other, and the plurality of facing portions have a structure in which the magnetic teeth of the adjacent facing portions have a staggered structure between the magnetic pole teeth forming the rear part of the front body. The linear mover having the magnet is arranged.

According to the present invention, the resin for feeding the molten resin fed from the tip of the screw to the tip side of the injection plunger into the holding block having the function of the injection cylinder arranged so that the injection plunger can be moved forward and backward Since the supply passage is configured to be formed in a straight line, the holding block that is a single member also serves as a member that forms the resin supply passage from the tip end side of the screw to the tip end side of the injection plunger. Thus, the number of parts can be reduced. Further, since the resin supply passage from the tip end side of the screw to the tip end side of the injection plunger is linear, the processing is easy as compared with a configuration in which the resin supply passage is bent. In addition, the fact that the resin supply passage is linear and that the total length of the resin supply passage can be made shorter than the bent configuration of the resin supply passage, it is possible to reduce resin retention and pressure loss during the metering process. Can be reduced.
Furthermore, since one extended line of the resin supply passage is not in contact with the holding block, the linear resin supply passage can be easily and easily drilled by electric discharge machining. The processing process of the supply passage can be simplified. Further, since the screw and the injection plunger are arranged in parallel, the total height of the metering / injection system mechanism can be suppressed.
Furthermore, the outer periphery of the holding block has a shape in which a circle and an oval shape are combined, and the band heater is wound around the circular outer periphery and the oval outer periphery of the holding block. The band heater can be arranged so that suitable temperature control can be performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 relate to a pre-plastic injection molding machine according to an embodiment of the present invention (hereinafter referred to as the present embodiment), and FIG. 1 illustrates a configuration of a main part of the pre-plastic injection molding machine of the present embodiment. FIG.

  In FIG. 1, reference numeral 1 denotes a function of an injection cylinder disposed so that the injection plunger can be moved forward and backward, and a resin supply passage that forms a resin supply passage from the tip end side of the screw to the tip end side of the injection plunger. A holding block having a function as a forming member, 1a is an oval section of the holding block 1, 1b and 1c are circular sections of the holding block 1, and 1d is horizontally drilled in the holding block 1. The plunger forward / reverse space 2 passing through the holding block 1 (circular section 1b, oval section 1a, circular section 1c) is disposed so as to be able to move forward and backward in the plunger forward / rearward space 1d. The injected injection plunger 3 is an injection nozzle fixed to the circular section 1b of the cross section of the holding block 1, and 3a is formed in the injection nozzle 3 so as to communicate with the plunger forward-reverse space 1d. The passage 4 is fixed and connected to the right end surface of the holding block 1 in the cross-sectional oval shape portion 1a, and the horizontally disposed plasticizing cylinder 5 is rotatable in the plasticizing cylinder 4. The screw 1e arranged in this manner is formed on the right end face side in the figure in the cross-sectional oval shape portion 1a of the holding block 1, and the recessed portion 1f incorporating the tip portion of the screw 5 is formed from the tip portion of the screw 5. In order to feed the molten resin to be sent out to the distal end side of the injection plunger 2, the holding block 1 is drilled so as to connect the concave portion 1e and the left end portion of the plunger forward / backward moving space 1d with a straight line, and is arranged horizontally in parallel. A resin supply passage 6 obliquely intersecting the axial center line of the screw 5 and the injection plunger 2 formed on the outer periphery of the holding block 1 (circular section 1b, oval section 1a, cross section circle) Band heaters 7 wound around the outer peripheral portion of the injection nozzle 3 and the outer peripheral portion of the plasticizing cylinder 4, respectively, move the injection plunger 2 linearly via the ball screw mechanism 8. And a rotary servomotor for back pressure control, 9 is a rotary servomotor for measurement that drives the screw 5 to rotate, 10 is a servo driver that drives the rotary servomotor 7 by feedback control, and 11 is a rotary type A servo driver 12 that drives the servo motor 9 by feedback control is a system controller that gives command values to the servo drivers 10 and 11 in accordance with preset measurement control conditions and injection control conditions.

  2 is a view of the holding block 1 as viewed from the left side in FIG. 1. As shown in FIG. 2, the outer periphery of the cross-sectional oval portion 1a of the holding block 1 (the oval outer peripheral portion) has a cross section. A band heater 6 having an oval contour is wound, and a band heater 6 having a circular cross section is wound around the outer peripheral portion (circular outer peripheral portion) of the circular cross section 1b of the holding block 1, which is shown in FIG. Although not provided, the band heater 6 having a circular cross section is wound around the outer peripheral portion (circular outer peripheral portion) of the circular section 1c of the holding block 1 in the same manner. Therefore, the band heater 6 can be easily attached to the holding block 1, and the band heater can be arranged so that the temperature of the holding block 1 can be suitably controlled.

  Further, in the present embodiment, as shown by a two-dot chain line in FIG. 1, the design is such that one extension line of the resin supply passage 1f does not come into contact with the holding block 1; When the resin supply passage 1f is drilled, the design is such that the linear wire does not come into contact with the holding block 1 (so as not to obstruct wire electric discharge machining). It is considered that 1f can be drilled in the holding block 1 simply and easily by electric discharge machining.

  In the configuration shown in FIG. 1, during the weighing process, the rotary servo motor 9 is rotationally driven via the servo driver 11 in response to a command from the system controller 12, thereby rotating the screw 5 in a predetermined direction. By the rotation of the screw 5, the resin material supplied to the rear side of the screw 5 (the rear side in the plasticizing cylinder 4) is transferred forward to the screw feeding action of the screw 5 while being kneaded and plasticized. The molten resin transported forward is fed from the distal end side of the screw 5 to the distal end side of the injection plunger 2 through the resin supply passage 1f, and the distal end side of the injection plunger 2 (in the plunger forward / rearward movement space 1d). As the molten resin accumulates, the injection plunger 2 moves backward in the plunger forward-reverse space 1d. At this time, the rotary servo motor 7 is driven and controlled by the command from the system controller 12 via the servo driver 10, whereby the back pressure applied to the injection plunger 2 is controlled via the ball screw mechanism 8. The plunger 2 moves backward. When a predetermined amount of molten resin is stored on the distal end side of the injection plunger 2 (in the plunger forward-reverse space 1d), the rotational drive of the screw 5 by the rotary servo motor 9 is stopped.

  On the other hand, during the injection / filling process, the rotary servo motor 7 is rotationally driven via the servo driver 10 in response to a command from the system controller 12 at an appropriate timing after the completion of weighing, and the injection plunger 2 is moved via the ball screw mechanism 8. Rapidly driven forward, the molten resin stored on the tip side of the injection plunger 2 passes through the resin supply passage 3a of the injection nozzle 3 and enters a mold cavity (not shown). Injection and filling.

  In the present embodiment having the above-described configuration, the molten resin fed from the tip of the screw 5 is injected into the holding block 1 having the function of an injection cylinder disposed so that the injection plunger 2 can be moved forward and backward. Since the resin supply passage 1f for feeding to the distal end side of the plunger 2 is formed in a straight line, the holding block 1 as a single member is moved from the distal end side of the screw 5 to the distal end side of the injection plunger 2. The member forming the resin supply passage 1f is also used, and the number of parts can be reduced. Further, since the resin supply passage 1f from the tip end side of the screw 5 to the tip end side of the injection plunger 2 is linear, the processing is easier than in a configuration in which the resin supply passage is bent. In addition, the resin supply passage 1f is linear, and the total length of the resin supply passage 1f can be made shorter than that of the configuration in which the resin supply passage is bent. Loss can also be reduced. Further, since one extended line of the resin supply passage 1f is not in contact with the holding block 1, the linear resin supply passage 1f can be easily and easily drilled by electric discharge machining. Thus, the processing process of the resin supply passage can be simplified. Further, since the screw 5 and the injection plunger 2 are horizontally arranged in parallel, the overall height of the metering / injection system mechanism can be suppressed. Furthermore, the band heater 6 can be disposed so that the band heater 6 can be easily attached to the holding block 1 and can be easily controlled, and the temperature of the holding block 1 can be suitably controlled.

  In the above-described embodiment, the injection plunger 2 is linearly driven by using the rotary servo motor 7 and the ball screw mechanism 8. However, as a drive source for the linear movement of the injection plunger 2, a tunnel actuator type is used. A linear motor may be used. This tunnel actuator type linear motor is well known, and the detailed description thereof is omitted here. For example, as shown in Japanese Patent Application No. 2004-168754 previously proposed by the applicant of the present application, such a tunnel actuator type linear motor is used. The linear motor includes a stator around which a winding is wound, and a mover that moves linearly with respect to the stator. The stator includes a plurality of opposed portions in which magnetic pole teeth are opposed to each other. The opposing portion of the present invention has a configuration in which the magnetic pole teeth of the adjacent opposing portions have a staggered structure, and a linear mover having a permanent magnet is disposed between the magnetic pole teeth constituting the opposing portion. Excellent acceleration / deceleration response. Therefore, if a tunnel actuator type linear motor is used as a drive source for the linear motion of the injection plunger 2, acceleration / deceleration response during injection / filling can be improved.

It is explanatory drawing which shows the principal part structure of the pre-plastic injection molding machine which concerns on one Embodiment of this invention. It is explanatory drawing which looked at the holding block in FIG. 1 from the left side. It is explanatory drawing which shows the principal part structure of the conventional prep plastic type injection molding machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Holding block 1a Cross-sectional oval part 1b, 1c Cross-section circular part 1d Plunger back and forth space 1e Recess 1f Resin supply passage 2 Injection plunger 3 Injection nozzle 3a Resin injection passage 4 Plasticizing cylinder 5 Screw 6 Band heater 7 Injection and back Rotary servo motor for pressure control 8 Ball screw mechanism 9 Rotary servo motor for weighing 10, 11 Servo driver 12 System controller

Claims (4)

In a pre-plastic injection molding machine having a screw for kneading and plasticizing resin raw materials and an injection plunger for injecting and filling molten resin into a mold,
The screw and the injection plunger are arranged in parallel, and are arranged in a holding block which is arranged so that the injection plunger can be moved forward and backward so as to be rotatable in the plasticizing cylinder. In addition to the built- in tip of the screw, a resin supply passage for feeding molten resin fed from the tip of the screw into the tip of the injection plunger crosses the axial center line of the screw and the injection plunger. Thus, a pre-plastic injection molding machine , wherein the holding block is linearly drilled. In the pre-plastic injection molding machine according to claim 1,
An outer periphery of the holding block is formed by combining a circular shape and an oval shape, and a band heater is wound around the circular outer periphery portion and the oval outer shape portion of the holding block, respectively. Molding machine. The pre-plastic injection molding machine according to claim 1 or 2,
A pre-plastic injection molding machine, wherein a drive source for linear motion of the injection plunger is a rotary servo motor . The pre-plastic injection molding machine according to claim 1 or 2,
The drive source of the linear motion of the injection plunger is a linear motor, and the linear motor includes a stator wound with a winding and a mover that moves linearly with respect to the stator. Has a plurality of facing portions where the magnetic pole teeth are opposed to each other, and the plurality of facing portions have a structure in which the magnetic teeth of the adjacent facing portions have a staggered structure, and a permanent magnet is interposed between the magnetic pole teeth constituting the rear part of the front body A pre- plastic injection molding machine, characterized in that the linear movable element is arranged .

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