JP2016112791A - Injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding machine with a purge shutter device which is inexpensive, can be easily applied to an existing injection molding machine, and prevents contamination caused by a purge resin on the side of a sprue bush and a cavity.SOLUTION: A purge shutter device 30 is provided between a stationary board 11 and a fixed side die 14 of a mold fastening unit 10. The purge shutter device is formed of a purge plate 31 and a purge shutter 32. When the purge plate 31 is mounted on a mounting surface 12 of the die 14 of the stationary board, the purge shutter 32 is guided by a guide groove 38 of the purge plate 31 and the mold mounting surface 12, and is driven so as to take an operation position for closing a small diameter part 21 of an injection nozzle insertion hole 20 communicated with a sprue 24 and a non-operation position for releasing the small diameter part 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an injection molding machine, and more particularly to an injection molding machine that includes an injection unit and a mold clamping unit, and a purge shutter device is provided on the mold clamping unit.

  As is conventionally known, an injection molding machine is generally composed of an injection unit and a mold clamping unit. The injection unit includes a heating cylinder, a screw provided inside the heating cylinder so as to be driven in the rotational direction and the axial direction, and the like. On the other hand, the mold clamping unit is a fixed mold attached to the fixed platen, a movable mold attached to the movable platen, a mold clamping device for clamping the movable mold to the fixed die, etc. It is composed of A pellet supply device is attached to the proximal end portion of the heating cylinder, an injection nozzle is attached to the distal end portion, and a band heater for heating is provided on the outer peripheral portion. Therefore, the injection material is supplied from the pellet supply device to the base end portion of the heating cylinder, and the process of plasticizing and measuring the screw by rotating the screw, the mold clamping process of clamping the movable plate to the fixed plate, and the measurement After that, the screw is driven in the axial direction from the injection nozzle to the cavity formed between the fixed side mold and the movable side mold, and the injection process, filling process, mold opening process, etc. are performed. Thus, a molded product can be obtained.

  As described above, in the process of obtaining a molded product by performing each process, when changing the mold to change the type of molded product, when waiting for the heating cylinder to rise to a predetermined temperature, etc. The molding must be interrupted. When the molding is interrupted, the injection material remaining in the high-temperature heating cylinder may be thermally deteriorated. If the injection material deteriorated during the next molding is mixed, the quality of the molded product will deteriorate. Therefore, the injection material remaining in the heating cylinder prior to the molding is removed by driving the screw. That is, it is purged. Further, even at the end of injection molding, the injection material is purged so as not to deteriorate and remain in the heating cylinder. Furthermore, the injection material in the heating cylinder is purged when the injection material is changed or when the color change molding is performed.

  In order to perform such purging more completely without removing the screw from the heating cylinder, the rotational speed and injection speed of the screw are set relatively high. Therefore, the purge resin is scattered per layer. When the purge agent is added, the scattering distance is further increased. Therefore, the injection molding machine is provided with various devices such as a purge cover and a purge shutter. Patent Document 1 is cited as a direct prior document of the present invention of an injection molding machine having such a purge resin scattering prevention device.

JP 2004-155133 A

  Patent Document 1 shows an injection molding machine in which a purge lump scattering prevention device 70 is provided between an injection unit 50 and a mold clamping unit 60, as shown in FIG. The injection unit 50 includes a heating cylinder 51 as is conventionally known. An injection nozzle 52 having a predetermined length in the axial direction is provided at the tip of the heating cylinder, and band heaters 53, 53,. On the other hand, the mold clamping unit 60 includes a stationary platen 61, a stationary mold 62 attached to the stationary platen 61, a movable mold 63 attached to the movable platen, and a mold clamping that opens and closes these molds. It consists of devices. A relatively large recess, that is, a nozzle insertion hole 65 is formed in the center of the fixed platen 61, and a sprue bush 66 is fitted in the fixed mold.

  The purge lump scattering prevention device 70 includes a pair of plate guide members 71 and 71 and a scattering prevention plate 72 that is slidably guided in the vertical direction by these guide members. The anti-scattering plate 72 has a nozzle tip insertion hole 73 through which the injection nozzle 52 is inserted when the plate is driven to the operating position, that is, the lower position. The purge lump scattering prevention device 70 configured as described above is provided on the back side of the fixed platen 61 of the mold clamping unit 60, that is, on the tip side of the injection unit 50. Reference numeral 75 denotes a purge cover.

  Therefore, when the anti-scattering plate 72 is slidably driven to the upper non-operation position, the injection unit 50 can be advanced and the injection nozzle 52 can be touched to the sprue bush 66 without being disturbed by the anti-scattering plate 72. . As a result, injection molding can be performed as conventionally known. Moreover, it can also purge as follows. That is, the injection unit 50 is driven rearward so that the tip portion of the injection nozzle 52 is positioned behind the anti-scattering plate 72. Then, the anti-scattering plate 72 is driven to the lower operating position. The anti-scattering plate 72 goes down to the operating position without being disturbed by the injection nozzle 52. The injection unit 50 is advanced by a predetermined amount. Then, the tip portion of the injection nozzle 52 is inserted through the nozzle tip insertion hole formed in the scattering prevention plate 72 by a predetermined amount 73. When inserted, the nozzle tip insertion hole 73 is closed, so that the nozzle insertion hole 65 formed in the fixed platen 61 is temporarily sealed by the scattering prevention plate 72. As is conventionally known, the screw of the injection unit 50 is driven and purged.

Since the anti-scattering plate 72 of the purge lump anti-scattering device 70 described in Patent Document 1 can be slidably driven between the operating position and the non-operating position, both injection molding and purging can be performed. In particular, since the purge lump scattering prevention device 70 is provided between the injection unit 50 and the mold clamping unit 60, the purge lump contaminates the band heaters 53, 53,... Wound around the outer periphery of the heating cylinder 51. The advantage of not doing is recognized. However, problems to be improved are also recognized. For example, since the purge lump scattering prevention device 70 is provided between the injection unit 50 and the mold clamping unit 60, the tip of the injection nozzle 52 is obstructive when the scattering prevention plate 72 is driven to the lower operating position. In order to avoid this, the injection unit 50 must be largely retracted backward so as to be located behind the anti-scattering plate 72. At least the thickness of the fixed platen 61 must be retracted. Accordingly, the moving distance of the injection unit 50 becomes longer, and the injection bed needs to be extended from the standard machine. That is, there is a drawback that the injection molding machine is enlarged. When the injection nozzle 52 is long, the moving distance becomes long, the machine is further enlarged, and the manufacturing cost is increased. For this reason, it cannot be easily applied to existing injection molding machines. Further, since no measures are taken on the side of the sprue bush 66, even if the hole diameter of the sprue hole is small, the purge lump passes through the sprue and reaches the cavity of the mold, and the inner peripheral surface of the sprue and the inner peripheral surface of the cavity There is also a possibility of polluting. High-quality molded products cannot be obtained.
Therefore, the present invention is inexpensive and can be easily applied to an existing injection molding machine, and in particular, an injection molding machine including a sprue bush due to a purge resin and a purge shutter device that prevents contamination on the cavity side. It is intended to provide.

  In the present invention, in order to achieve the above object, the purge shutter device is provided toward the mold clamping unit. That is, the mold clamping unit is composed of a fixed platen, a fixed mold attached to the fixed platen, a movable mold attached to the movable platen, a mold clamping device for opening and closing these plates or molds, and the like. However, the purge shutter device according to the present invention is disposed between the fixed platen and the fixed side mold.

  The purge shutter device according to the first invention comprises a purge plate and a purge shutter that is slidably guided in a guide groove formed in the purge plate and takes an operating position and a non-operating position. That is, the purge plate is fixedly attached to the fixed platen, and the purge shutter is configured to be slidably driven between the fixed platen and the purge plate. The purge shutter device according to the second invention comprises a purge shutter. The purge shutter is guided by a guide groove formed in the stationary platen and takes an operating position and a non-operating position.

  Specifically, in order to achieve the above object, the invention according to claim 1 includes an injection unit and a mold clamping unit, and a purge shutter device is attached to the fixed disk and the fixed disk constituting the mold clamping unit. The purge shutter device includes a plate-like purge plate and a guide groove formed on the purge plate, the one surface of which is slidable. When the purge plate is mounted on a mold mounting surface of the fixed plate facing the fixed mold, the purge shutter includes the guide groove and the mold mounting surface. Driven to take an operating position for closing the small diameter portion of the injection nozzle insertion hole formed in the stationary platen and communicating with the sprue and a non-operating position for releasing the guide nozzle. Configured to be.

  The invention according to claim 2 is composed of an injection unit and a mold clamping unit, and the purge shutter device is provided between a stationary platen constituting the mold clamping unit and a fixed side mold attached to the stationary platen. The purge shutter device comprises a plate-like purge shutter, and when the purge shutter is incorporated between the fixed platen and a fixed side mold, the fixed platen, Guided by a guide groove formed on the mold mounting surface facing the fixed side mold and a guide plug mounted on the guide groove, or mounted on the mold of the guide groove and the fixed side mold And is configured to be driven so as to take an operating position for closing a small-diameter portion of an injection nozzle insertion hole formed in the fixed plate and communicating with the sprue and a non-operating position for releasing. The

  The invention according to claim 3 is configured such that the purge shutter of the purge shutter device according to claim 1 or 2 is cooled by cooling water, and the invention according to claim 4 is the invention according to claim 1 or 2. The purge shutter of the purge shutter device according to claim 5 is surface-treated, and the invention according to claim 5 is that the purge shutter of the purge shutter device according to any one of claims 1 to 4 is in the operating position. In some cases, an interlock is provided so that the injection nozzle of the injection unit cannot touch the mold, or when the injection nozzle touches the mold, the purge shutter of the purge shutter device cannot be driven to the operating position. A circuit is provided.

  As described above, according to the first aspect of the present invention, the purge shutter device includes the purge plate and the purge shutter. When the purge plate is attached to the die mounting surface of the stationary platen, The structure is very simple because it is assembled between the mold and the fixed mold. Therefore, it is inexpensive. Moreover, it can be easily applied to an existing injection molding machine simply by attaching the purge plate to the mold mounting surface of the fixed platen. In addition, the purge shutter is guided by the guide groove and the mold mounting surface, and can take an operation position that closes the small diameter portion of the injection nozzle insertion hole that is formed in the stationary plate and communicates with the sprue. An effect is obtained in which the purge resin that is driven to the position and thus reaches the sprue and thus the cavity can be shut off.

  According to the second aspect of the present invention, the structure is further simplified and less expensive because the purge shutter is used. And when it is assembled between the fixed platen and the fixed mold, the guide plate is mounted on the guide groove formed on the mold mounting surface of the fixed plate facing the fixed mold. A small-diameter portion of an injection nozzle insertion hole that is guided by a guide plug or guided by the guide groove and a mold mounting surface of the fixed-side mold and communicated with the sprue. As in the first aspect of the present invention, it can be easily applied to an existing injection molding machine, and is driven to the operating position to be sprue and cavity. Thus, the effect of blocking the purge resin that is about to be reached can be obtained.

  According to the third and fourth aspects of the invention, since the purge shutter is cooled or surface-treated, it is possible to prevent adhesion of the purge resin in addition to the above effects. According to the fifth aspect of the present invention, since the interlock circuit is provided, the purge shutter device or the injection unit can be operated more safely.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the injection molding machine which concerns on the 1st Embodiment of this invention, The (a) is a front view which shows partially embodiment of an injection unit and a mold-clamping unit in which a purge shutter is a non-operation state, 1A is a side view seen in the direction of arrow II in FIG. 1A, FIG. 1B is a plan view seen from above in FIG. 1A, and FIG. 2A is a cross-sectional view as viewed in the direction of arrow A in FIG. 1, and FIG. 1E is a cross-sectional view corresponding to FIG. 1D, showing the main part when the purge shutter is in a moving state. It is a figure which shows the principal part of 2nd, 3rd Embodiment of this invention, The (a) is sectional drawing which shows the principal part of the non-operation state of the purge shutter which concerns on 2nd Embodiment, 2) is a plan view seen from above in FIG. 2A, FIG. 2C is a cross-sectional view showing the main part when the purge shutter according to the third embodiment is in an inoperative state, and FIG. It is the top view seen from upper direction in (c). It is a front view which shows a prior art example with a partial cross section.

  Embodiments of the present invention will be described below. As shown in part in FIG. 1A, the injection molding machine according to the present embodiment includes an injection unit 1 and a mold clamping unit 10. The injection unit 1 is configured as conventionally known. That is, the injection unit 1 includes a heating cylinder 2. A screw is inserted into the heating cylinder 2 so as to be driven in the rotational direction and the axial direction, and a plurality of band heaters 3, 3,. An injection nozzle 4 is provided at the front, a hopper for supplying material is provided near the rear, and a screw driving device is provided at the rearmost end. The heating cylinder 2 configured as described above is mounted on a moving frame that is driven in the nozzle touch direction and in the direction away from the nozzle touch direction, that is, in the axial direction.

  As is conventionally known, the mold clamping unit 10 includes a fixed platen 11 fixed on the gantry, a mold clamping housing provided on the gantry so as to be axially movable at a predetermined distance from the fixed platen 11, The four tie bars 13, 13,... Provided between the fixed platen 11 and the mold clamping housing are attached to the fixed platen 11, a movable plate guided and moved in the axial direction by the tie bars 13, 13. The movable side mold 14 is attached to the movable plate in the same manner, the movable side die 16 is similarly attached to the movable platen, the toggle mechanism for driving the movable plate with respect to the fixed platen 11 in the mold closing direction or the mold opening direction. .

  According to this embodiment, the injection plate insertion hole 20 is formed in the fixed platen 11 so as to penetrate the platen 11 in the front-rear direction. The injection nozzle insertion hole 20 includes a front small diameter portion 21 and a rear large diameter portion 22. The diameter of the small diameter portion 21 is larger than the diameter of the injection nozzle 4 and can be driven both in the nozzle touch direction and in the direction away from the injection nozzle 4 without touching the inner peripheral surface of the small diameter portion 21.

  A locating ring 23 is fitted into a mold mounting surface 15 of the fixed side mold 14 facing the fixed platen 11 as is well known in the art. In the embodiment shown in FIG. 1A, the locating ring 23 projects rearward from the rear surface of the fixed mold 14, that is, the mold mounting surface 15 when mounted on the stationary platen 11. Yes. The axis of the locating ring 23 is aligned with the axis of the small diameter portion 21 of the injection nozzle insertion hole 20 and the axis of the injection nozzle 4. A sprue bush 24 is attached to the locating ring 23 configured in this manner, although it is not accurately shown in FIG. As is well known, the sprue bush 24 opens into the cavity 25 through a runner, a gate, and the like.

  A purge shutter device 30 according to the first embodiment shown in FIG. 1 includes a plate-like purge plate 31 and a similar plate-like purge shutter 32. And it is provided between the mold mounting surface 12 to which the fixed mold 14 is mounted on the front surface of the fixed platen 11 and the mold mounting surface 15 to be mounted on the fixed plate on the rear surface of the fixed mold 14. ing. Since the purge plate 31 is attached to the mold attachment surface 12 of the fixed platen 11, the side shape thereof is substantially the same as the side shape of the fixed platen 11, as shown in FIG. A through hole 34 having the same diameter as that of the small diameter portion 21 of the injection nozzle insertion hole 20 is formed at the center thereof. The through hole 34 is aligned with the small diameter portion 21 when attached. Further, through holes 35, 35,... For penetrating tie bars 13, 13,... Are formed at four corners of the purge plate 31, and bolt insertion holes 36, 36,. Furthermore, although not shown in the drawing, an attaching means for attaching the stationary mold 14 to the stationary platen 11 is also provided as appropriate.

  In the purge plate 31 configured as described above, a guide groove 38 for slidingly guiding the purge shutter 32 is formed on the right side surface, that is, the rear surface in FIG. The depth and width of the guide groove 38 are larger than the thickness and width of the purge shutter 32 by a predetermined amount so that they can be slidably guided. In the illustrated embodiment, the guide groove 38 is formed in the vertical direction so as to reach the lower edge of the through hole 34 from the upper edge of the purge plate 31. A part of the guide groove 38 having such a shape is shown in FIGS.

  The purge shutter device 30 according to the present embodiment is manufactured or assembled as follows. That is, the fixed mold 14 is removed from the fixed platen 11. The purge plate 31 of the purge shutter device 30 is inserted from the purge shutter 32 side into the tie bars 13, 13,. Then, the mounting bolts 39, 39,... Are inserted into the bolt insertion holes 36, 36,... And screwed into female threads formed in advance on the mold mounting surface 12 side of the stationary platen 11. Thus, the purge shutter device 30 is attached to the fixed platen 11. When attached, the purge shutter 32 is slidably guided by the guide groove 38 and the mold attachment surface 12 of the fixed platen 11. The fixed mold 14 is attached to the fixed platen 11. This completes the assembly. The state after assembly is shown in FIG.

  Next, the operation of the above embodiment will be described. The injection unit 1 plasticizes and measures the injection material as is conventionally known. The purge shutter 32 is driven to the upper inoperative position. Then, the through hole 34 of the purge plate 31 is opened. The injection unit 1 is advanced, and the injection nozzle 4 is touched to the locating ring 23 of the fixed mold 14. Then, the injection material being measured is injected into and filled in the cavity 25 configured by driving the screw of the heating cylinder 2 forward and clamping the mold. Waiting for cooling and solidification, the movable mold 16 is opened. The ejector pin protrudes in conjunction with mold opening, and the molded product is taken out. Thereafter, a molded product is obtained in the same manner.

  When purging the inside of the heating cylinder 2, the injection nozzle 4 is retracted backward from the purge shutter 32. Then, the purge shutter 32 can be driven to the lower operating position. Drive to operating position. The driven state is shown in FIG. Thus, the through hole 34 of the purge plate 31, and thus the small diameter portion 21 of the injection nozzle insertion hole 20 is closed by the purge shutter 32. That is, the front of the injection nozzle insertion hole 20 is sealed. As is conventionally known, the screw is driven to purge. Since the through hole 34 of the purge plate 31 is closed by the purge shutter 32, the purge resin does not reach the locate ring 23, the sprue bush 24, the cavity 25, and the like. That is, these members are not contaminated by the purge resin.

  This embodiment can be variously modified. For example, although the purge shutter 32 is described as being driven manually, the purge shutter 32 may be automatically driven by a servo motor, a hydraulic motor, or the like. At this time, a limit switch or the like is disposed at the upper and lower limit positions of the purge shutter 32, and the purge shutter 32 is operated so that the purge shutter 32 is not driven to the operating position when the injection nozzle 4 is touching the mold. When in position, an automatic operation can be performed by providing an interlock circuit so that the injection nozzle 4 is not driven in the mold touch direction. Further, in the above embodiment, the purge shutter 32 is driven in the vertical direction, and the upper side is the non-operating position and the lower side is the operating position. It can also be implemented so as to assume the operating position and the non-operating position when driven downward. In this way, when the driving source of the shutter driving device is lost, the purge shutter 32 is lowered to its lower inoperative position due to its own weight and is safe. Furthermore, the purge shutter 32 can be provided so as to be slidable in a direction other than the vertical direction, for example, in a horizontal direction or an oblique direction, depending on the layout.

  Since high-temperature purge resin is likely to adhere to the surface of the purge shutter 32, a cooling pipe may be provided on the purge shutter 32 so that the cooling water is circulated during the purge. Alternatively, surface treatment such as non-metal film treatment, chemical conversion treatment, and polishing can be performed to prevent adhesion. Further, as indicated by a dotted line in FIG. 1A, for example, a purge cover PK as shown in Japanese Patent Application Laid-Open No. 2004-155133, 2013-216057 or the like is attached to the tip of the heating cylinder 2. It can also be provided so as to cover the part.

  FIG. 2 shows the second and third embodiments of the present invention. In the first embodiment described above, the purge shutter device 30 is composed of two members, the purge plate 31 and the purge shutter 32, but according to the second and third embodiments, one member of the purge shutter 32 ′. It is composed of Therefore, the guide groove 40 is formed on the mold mounting surface 12 side of the fixed platen 11. The same reference numerals are given to the same elements as the constituent elements of the first embodiment, and the same reference numerals are given the same reference numerals with a dash “′”, or some of the constituent elements are omitted and repeated. I do not.

  According to the second embodiment, as shown in FIG. 2A, the locating ring 23 attached to the fixed-side mold 14 is moved backward from the mold mounting surface 15, in other words, injection. Since it protrudes toward the nozzle insertion hole 20, a deep guide groove 40 is formed on the mold mounting surface 12 side of the stationary platen 11. That is, as shown in FIG. 2A, the guide groove 40 has a depth in which the purge shutter 32 ′ in contact with the bottom surface and the lid-shaped guide plug 41 for guiding the purge shutter 32 ′ can be accommodated. It has become. The thickness of the guide plug 41 is larger than the protruding amount of the locate ring 23. Therefore, the purge shutter 32 ′ is driven to the lower operating position without being obstructed by the locate ring 23. According to the third embodiment, as shown in FIG. 2C, the locating ring 23 ′ does not protrude rearward from the mold mounting surface 15 of the fixed mold 14. That is, they are substantially the same surface. Accordingly, the guide groove 40 'is shallow, and the purge shutter 32' is guided by the guide groove 40 'and the mold mounting surface 15 of the fixed side mold 14 as shown in FIG. It is driven to the non-actuated position and the actuated position. It is clear that the second and third embodiments operate in the same manner as the first embodiment.

  When the purge shutter device 30 according to the first embodiment is applied to an existing injection molding machine, the thickness of the purge plate 31 and the purge shutter 32 affects the thickness of the molds 14 and 16. The third embodiment can be easily applied only by processing the grooves 40 and 40 ′ in the fixed platen 11. Since it is obvious that the second and third embodiments can be modified in the same manner as the first embodiment, the description thereof will not be repeated.

DESCRIPTION OF SYMBOLS 1 Injection unit 2 Heating cylinder 4 Injection nozzle 10 Mold clamping unit 11 Fixing board 12 Mold mounting surface 14 Fixed side mold 15 Mold mounting surface 20 Injection nozzle insertion hole 21 Small diameter part
23, 23 'Locate ring 24 Sprue bush 30 Purge shutter device 31 Purge plate 32, 32' Purge shutter 34 Through hole 38, 40, 40 'Guide groove 41 Guide plug

Claims (5)

An injection molding machine comprising an injection unit and a mold clamping unit, wherein the purge shutter device is provided between a fixed plate constituting the mold clamping unit and a fixed mold attached to the fixed plate. ,
The purge shutter device comprises a plate-like purge plate and a purge shutter whose one surface is slidably guided by a guide groove formed in the purge plate.
When the purge plate is mounted on a mold mounting surface of the fixed plate facing the fixed mold, the purge shutter is guided by the guide groove and the mold mounting surface and formed on the fixed plate. An injection molding machine, wherein the injection molding machine is driven to take an operating position for closing a small diameter portion of an injection nozzle insertion hole communicated with a sprue and a non-operating position for releasing. An injection molding machine comprising an injection unit and a mold clamping unit, wherein the purge shutter device is provided between a fixed plate constituting the mold clamping unit and a fixed mold attached to the fixed plate. ,
The purge shutter device comprises a plate-like purge shutter,
When the purge shutter is incorporated between the fixed platen and the fixed mold, a guide groove formed on a mold mounting surface of the fixed plate facing the fixed mold, and the guide groove Injection nozzle insertion hole communicated with a sprue, formed in the fixed plate, guided by a guide plug to be mounted or guided by the guide groove and a mold mounting surface of the fixed mold. An injection molding machine that is driven so as to adopt an operating position for closing a small-diameter portion and a non-operating position for releasing. An injection molding machine, wherein the purge shutter of the purge shutter device according to claim 1 or 2 is cooled by cooling water. An injection molding machine, wherein the purge shutter of the purge shutter device according to claim 1 or 2 is surface-treated. When the purge shutter of the purge shutter device according to any one of claims 1 to 4 is in the operating position, the injection nozzle of the injection unit cannot touch the mold, or the injection nozzle is attached to the mold. An injection molding machine, wherein an interlock circuit is provided so that the purge shutter of the purge shutter device cannot be driven to the operating position when touched.

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