Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/38—Cutting-off equipment for sprues or ingates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/20—Injection nozzles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/26—Moulds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
  • B29C45/56—Means for plasticising or homogenising the moulding material or forcing it into the mould using mould parts movable during or after injection, e.g. injection-compression moulding
  • B29C45/561—Injection-compression moulding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/72—Heating or cooling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/26—Moulds
  • B29C45/263—Moulds with mould wall parts provided with fine grooves or impressions, e.g. for record discs
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S425/00—Plastic article or earthenware shaping or treating: apparatus
  • Y10S425/81—Sound record

Definitions

• the present invention relates to an injection molding machine that molds a molded body using a mold, and in particular, at the time of molding the molded body, the molding efficiency is improved without sprue being formed together with the molded body to be a product. It relates to an injection molding machine.
• thermoplastic resin as a raw material is fed into a heating cylinder, and the resin is melted by a reciprocating screw provided in the heating cylinder. While feeding to the nozzle side of the screw tip, the molten resin is injected from the nozzle provided on the screw tip side into the mold device cavity, and after the molten resin is cooled and solidified in the cavity, the mold device is opened. The molded body is molded by removing the molded product from the mold by sticking it to the mold with a protruding pin.
• an injection molding machine for molding a molded body such as plastic is roughly composed of a mold clamping unit and an injection unit, and a mold clamping unit is generally used.
• a mold device having a fixed mold and a movable mold, and the movable mold can be moved relative to the fixed mold by a movable means that enables clamping such as a toggle mechanism or a direct pressure method.
• the mold is advanced and retracted, and the mold is closed and opened when the mold is clamped.
• An injection unit is used when pellets, which are granular resins, are supplied as molten resin to the cavity formed when the mold of the mold apparatus is clamped.
• the injection unit includes a drive source A drive means such as a motor is provided, and the screw in the heating cylinder is rotated by a ball screw mechanism that sequentially transmits the rotational force of the motor via a pulley, a benolet, etc., and converts the rotational motion into linear motion.
• the molten resin is conveyed, and then the molten resin is injected from the nozzle into the cavity between the molds provided in the clamping unit.
• Patent Document 1 one of the fixed members forming a cavity composed of a fixed type and a movable type is fixed.
• a recess is provided in the center of the mold, and a compression core that fits into the recess is provided in the center of the movable mold so that it can move forward and backward.
• the tip of the hot nozzle inserted into the fixed mold protrudes into the center of the recess, and the recess.
• a runner-less mold is disclosed in which a runner portion that is opened and closed by a compression core is formed between the compression core and the compression core, and the resin layer remains in the recess when the compression core advances.
• Patent Document 1 Japanese Patent Laid-Open No. 8-281714
• Patent Document 1 in the molding after the resin layer remains in the recess, the resin remaining in the recess when the compression core advances is such that the recess has a concave shape.
• the thickness of the resin layer relative to the thickness of the molded product is about one-half dimension (see Fig. 4 of Patent Document 1), and it is avoided that a relatively thick resin layer remains in the recess.
• the remaining resin layer is laminated for each molding, and the thickness of the resin layer changes. Changing the thickness of the resin layer also means changing the size of the gate, which can adversely affect the molding quality.
• the present invention solves the above-described problems, and improves the quality of a molded body to be molded, and is used as a product that is integrally molded with a molded body that is a product when the molded body is molded. It is an object of the present invention to provide an injection molding machine with improved production efficiency that prevents the production of unmolded parts from being wasted.
• An injection molding machine is a cavity formed by a fixed mold and a movable mold.
• a nozzle receiving part configured on the fixed mold side of the nozzle is slightly protruded toward the movable mold, and a core part facing the nozzle receiving part is provided in the movable mold so as to be capable of moving forward and backward.
• the tip of the nozzle is arranged on substantially the same plane as the tip of the receiving portion, and a protruding portion is provided at the core portion facing the tip of the nozzle for injecting molten resin, so that the resin injected into the cavity
• the resin is gate-cut by advancing the core portion and being pressed by the advanced core portion and retreating the nozzle receiving portion and nozzle, and the gate cut causes the nozzle receiving portion and the tip of the nozzle to
• the resin film is configured to remain.
• the molten resin injected from the nozzle is filled from the gate to the cavity, and then, when the core portion advances, the nozzle receiving portion and the nozzle are pressed and moved backward by the advance operation of the core portion. After the gate is cut, the movable mold is retracted and the mold is opened. At this time, the resin between the core portion, the nozzle receiving portion and the nozzle is solidified by cooling and integrated with the resin filled in the nozzle, so that the nozzle receiving portion and the nozzle are integrated. Therefore, when the resin is filled into the cavity at the next cycle, the remaining resin is melted by heat such as molten resin supplied from the nozzle and used as the resin to be filled into the cavity.
• the protrusion can be used as a part of a molded body to be molded at the next molding cycle. Further, since the protrusion is provided at the core portion that opposes the tip of the nozzle for injecting the molten resin, the protrusion enters the inside of the tip of the nozzle, and causes the molding tip (defective appearance) inside the nozzle tip. The remaining cold slag can be reduced.
• An injection molding machine according to claim 2 is the injection molding machine according to claim 1, wherein the nozzle is provided with a heater.
• the nozzle receiving portion configured on the fixed mold side of the cavity formed by the fixed mold and the movable mold is provided in the movable mold.
• Head The core portion facing the nozzle receiving portion is provided on the movable mold so as to be able to advance and retreat, and the tip end of the nozzle is arranged on substantially the same plane as the tip end portion of the nozzle receiving portion.
• Protrusion is provided at a portion of the core portion that faces the tip of the nozzle that injects resin, and the resin injected into the cavity advances the core portion and is pressed against the advanced core portion to press the nozzle receiving portion.
• the resin is gate-cut by retreating the nozzle, and the resin film is left on the nozzle receiving portion and the tip of the nozzle by this gate cut. It can be used as a part of a molded body formed during a cycle. Therefore, when molding a molded body, it is possible to prevent a molded part that is not used as a product that is molded integrally with the molded body that is the product from being wastedly produced as a sprue, so that production efficiency can be improved.
• the nozzle is provided with a heater.
• the solidified film-like resin can be used as a part of the molded body.
• FIG. 1 is a partially cutaway side view showing a state where a mold of an injection molding machine showing an example of the present invention is opened.
• FIG. 2 is an enlarged cross-sectional view of the main part of the mold apparatus.
• FIG. 3 is an enlarged cross-sectional view of the main part of the mold apparatus showing a state where the molten resin is filled in the cavity.
• FIG. 4 is an enlarged cross-sectional view of a main part of the mold apparatus showing a state where the mold is clamped in a state where a predetermined amount of molten resin is filled in the cavity.
• FIG. 5 is an enlarged cross-sectional view of the main part of the mold apparatus showing a state in which the core part has advanced and gate cut.
• FIG. 6 is an enlarged cross-sectional view of the main part of the mold apparatus showing a state where the mold is opened after the gate cut is completed.
• FIG. 1 is a partially cutaway side view showing a state in which a mold of an injection molding machine showing an example of the present invention is opened, and FIGS. 2 to 6 are main parts of a mold apparatus configured in the injection molding machine. It is an expanded sectional view which shows a part.
• an injection molding machine 1 has a machine base 2, and an injection unit 3, a mold clamping unit 4, and a mold device 5 are arranged on the machine base 2.
• the screw 6 of the injection unit 3 is rotated to send molten resin to the mold cavity C.
• 3 has a hopper 7 into which resin (pellet), which is a granular raw material, is charged, and the granular resin is self-weighted from the hopper 7 into a cylindrical heating cylinder 8 provided therebelow. Will be dropped and thrown in!
• the injection unit 3 rotates the screw 6 and measures the molten resin supplied into the heating cylinder 8 and heated.
• the injection unit 3 includes a screw rotation drive motor 9 as a drive source.
• the pulley 11 fixed to the rotary shaft portion 10 of the rotary drive motor 9 rotates on the rear side of the screw 6 via the timing drive timing belt 12, whereby the screw 6 is rotated in conjunction with it.
• an injection drive motor is fixed to the rear support frame 13 mounted on the machine base 2, and is used for injection drive.
• the ball screw part 14 which is composed of a ball screw unit, which will be described later, is rotated via a drive transmission mechanism consisting of a timing belt for injection drive, etc., and is supported on the front side fixed on the machine base 2
• the frame 15 and the rear support frame 13 are connected by a cylindrical tie bar 17.
• the ball screw unit is described as follows.
• the nut portion 16 formed in the ball screw unit holds the screw 6 rotatably and is attached to the screw holding plate 18 guided by the tie bar 17. It has been. Further, the screw rotation drive motor 9 is fixed to the screw holding plate 18, and when the nut portion 16 is advanced by the injection drive motor and the ball joint, molten resin is injected into the cavity C, while retreating. Then, plasticization / weighing of the resin injected into the cavity C is performed.
• the ball screw portion 14 rotates the ball screw portion 14 forward and backward so that the nut portion 16 advances and retreats in the front-rear direction.
• the ball screw portion 14 is pivotally supported by the rear support frame 13, When the nut portion 16 that moves back and forth in the axial direction of the ball screw portion 14 (the left-right direction shown in FIG. 1) is movable, the steel ball repeatedly passes while rolling between the not-shown groove portion between the nut portion 16 and the ball screw portion 14. By doing so, the nut portion 16 force S smoothly advances and retreats with respect to the ball screw portion 14.
• the inline screw 6 rotatably provided in the heating cylinder 8 fixed to the front support frame 15 includes a screw S and a screw that are rotated using a screw rotation drive motor 9 as a drive source.
• 6 has a function of moving the molten resin supplied between the screw 6 and the heating cylinder 8 to the nozzle 20 on the tip side of the screw 6, while moving forward as a plunger for injecting the molten resin into the cavity C.
• the nozzle 20 is provided with a heater, and the rear part of the nozzle 20 is screwed to the inner front end side in the heating cylinder 8, and the cavity C including the movable mold 21 and the fixed mold 22 is included in the cavity C.
• Molten resin is supplied from the tip of the nozzle 20.
• the heater provided in the nozzle 20 prevents the temperature of the molten resin in the nozzle 20 filled in the cavity C from being lowered.
• the mold clamping unit 4 moves the movable mold 21 forward and backward with respect to the fixed mold 22 to clamp the mold (mold A mold clamping drive device 23 for closing and opening the mold, and sticking it in the movable mold 21 when the mold is opened! It has.
• a tail stock 24, a fixed die plate 25, and a movable die plate 26 are provided on the machine base 2, and are fixed to the tail stock 24 fixed on the machine base 2.
• the die plate 25 is connected by a plurality of cylindrical tie rods 27.
• the movable die plate 26 is provided with a drive device 29 for moving a core portion described later by a ball screw mechanism 28.
• a mold clamping motor 30 is fixed to the upper part of the tailstock 24 and is a driving source for clamping the movable mold 21 to the fixed mold 22.
• the pulley 31 is rotatably attached to the mold clamping motor 30, and the mold clamping motor 30 is pivotally supported on the tailstock 24 via the mold clamping timing belt 31A.
• the pulley 32 is rotated, and the drive force is transmitted to the toggle mechanism 33 by the drive transmission mechanism for transmitting such drive.
• the link arm 34 composed of a plurality of arms configured in the toggle mechanism 33 is shrunk and the mold is opened (the state shown in FIG. 1) when the mold is closed.
• the movable arm 21 is closed (clamped) with respect to the fixed mold 22 by the link arm 34 extending linearly.
• the mold clamping motor 30 is opened by rotating the mold clamping motor 30 in the reverse direction during mold clamping.
• the mold apparatus 5 includes a movable mold 21 fixed to a movable die plate 26 and a fixed mold 22 fixed to a fixed die plate 25. As the movable die plate 26 moves forward and backward, The movable mold 21 advances and retreats with respect to the fixed mold 22, and the mold is opened and closed. Further, as shown in FIG. 2, a nozzle insertion hole 35 is formed in a substantially central portion of the fixed mold 22 so that the tip of the nozzle 20 can be passed therethrough.
• the movable die 21 is assembled with a core portion 36 that is moved forward and backward through a ball screw mechanism 28 by a drive device 29 that constitutes a drive motor, and the core portion 36 is moved forward and backward.
• a drive device 29 that constitutes a drive motor
• the tip of the nozzle receiving portion 37 that is interposed between the fixed mold 22 and the nozzle 20 and is slightly protruded toward the movable mold 21 is pressed and moved backward. It has become.
• the protruding portion 38 is provided in the core portion 36 so as to face the tip of the nozzle 20 for injecting the molten resin.
• an eject sleeve 42 that protrudes and takes out the molded body in the mold between the core section 36 provided with the projecting section 38 on the body and the movable mold 21.
• a stamper holder 39 for attaching a stamper is provided between the nozzle receiving portion 37 and the fixed mold 22.
• the tip of the nozzle 20 and the nozzle receiving portion 37 are arranged in substantially the same plane as the planar portion (stamper) 40 that forms the cavity C in the fixed mold 22. More specifically, it protrudes slightly toward the core portion 36 rather than the planar portion 40.
• FIG. 3 is a state in which the cavity shown in FIG. 2 is being filled with molten resin
• FIG. 4 is a predetermined amount of molten resin.
• Fig. 5 shows a state in which the mold is clamped while being filled in the cavity
• Fig. 5 shows a state in which the core portion is advanced and gate cut
• Fig. 6 shows a state in which the die is opened after the gate cut is completed.
• the molten resin is compressed by the core portion 36, and even when the mold is opened as shown in FIG. In addition, it remains as a film at the tip of the nozzle receiving portion 37, and this remaining molten resin is used as a part of the molded body in the next molding cycle.
• the tip of the nozzle 20 is shut by the projecting portion 38 so that the molten resin supplied from the nozzle 20 on the screw 6 side flows.
• the effect of pressure propagation can be suppressed, the amount of molten resin between the core 36 and the nozzle 20 before gate cutting can be reduced, causing cracks in the molded body due to residual stress and microcracks, and poor bonding of the molded body Cut burr can be prevented, and as a result, the film thickness of the resin remaining after gout cutting can be reduced.
• the tip of the nozzle receiving portion 37 formed on the fixed mold 22 side of the cavity C formed by the fixed mold 22 and the movable mold 21 is connected to the movable mold 21.
• the core portion 36 facing the nozzle receiving portion 37 is provided on the movable die 21 so as to be able to advance and retreat, and the tip of the nozzle 20 is arranged on substantially the same plane as the tip of the nozzle receiving portion 37.
• a protruding portion 38 is provided at a portion of the core portion 36 that opposes the tip of the nozzle 20 for injecting the molten resin, and the core portion 36 is advanced while the resin injected to the cavity C is advanced.
• the resin gate is cut, and by this gate cutting, the resin film remains on the tip of the nozzle receiving portion 37 and the nozzle 20.
• the molten resin ejected from the nozzle 20 is filled into the cavity C from the gate 41, and then when the core portion 36 moves forward, the nozzle receiving portion 37 and the nozzle 20 are moved by the forward movement of the core portion 36.
• the movable mold 21 is retracted and the mold is opened. At this time, the resin between the core portion 36 and the nozzle receiving portion 37 and the nozzle 20 is solidified by cooling and integrated with the resin filled in the nozzle 20, so that the nozzle receiving portion is obtained.
• the resin Since the resin remains in the form of a film at the tip of part 37 and nozzle 20, the molten resin supplied from nozzle 20 at the time of filling resin into cavity C at the next cycle is used. By using it as a resin that is melted by heat of fat or the like and filled into the cavity c, it can be used as a part of a molded product to be molded at the next molding cycle. Therefore, the remaining resin can be used as a part of a molded product molded during the next molding cycle.
• a recording medium compact disc or video disc
• the protruding portion 38 is provided at the portion of the core portion 36 that opposes the tip of the nozzle 20 that injects the molten resin, the protruding portion 38 is disposed so as to enter the inside of the tip of the nozzle 20, thereby causing the appearance defect.
• the cold slug remaining inside the tip of the nozzle 20 is reduced, and the film thickness of the resin remaining at the tip of the nozzle receiving portion 37 and the nozzle 20 is adjusted to a predetermined thickness S it can. Accordingly, since the resin can remain as a thin film in the nozzle receiving portion 37 and the nozzle 20, the quality of the molded body is adversely affected by the change in the thickness of the remaining resin layer as in the conventional case. This can be prevented.
• the nozzle 20 is provided with a heater, when the film-like resin solidified by cooling is left in the cavity C, the film-like molten resin is heated by the heater provided in the nozzle 20. By melting, the cavity C can be smoothly filled with the film-like resin together with the molten resin supplied by injection from the nozzle 20. Therefore, the remaining film-like resin can be used as a part of the molded body.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=39183598

Family Applications (1)

Country Status (7)

Citations (3)

Family Cites Families (19)

• 2006
  • 2006-09-12 JP JP2006247351A patent/JP4647568B2/ja not_active Expired - Fee Related
• 2007
  • 2007-08-10 TW TW096129754A patent/TW200827139A/zh not_active IP Right Cessation
  • 2007-08-21 US US12/374,119 patent/US8016588B2/en not_active Expired - Fee Related
  • 2007-08-21 KR KR1020087031025A patent/KR20090060217A/ko not_active Withdrawn
  • 2007-08-21 CN CN2007800313837A patent/CN101505940B/zh not_active Expired - Fee Related
  • 2007-08-21 EP EP07805952A patent/EP2062716A1/en not_active Withdrawn
  • 2007-08-21 WO PCT/JP2007/066151 patent/WO2008032533A1/ja not_active Ceased

Patent Citations (3)

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