JP2010137391A - Material feeding device and method for operating material feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material feeding device which solves problems wherein, for example, the airtight seal of a shutter is damaged or the defective opening/closing of the shutter is caused by resin powder etc., which entered sliding clearance between a shutter member and a member to be slid or problems wherein, for example, the resin powder and the metal powder of the shutter are supplied into a heating cylinder to cause burning and a decline in the quality of a molding and a method for operating the device. <P>SOLUTION: The material feeding device 13 which supplies molding material M into the heating cylinder 15 capable of being vacuum-sucked through feeding routes 18, 19, and 20 includes shutter devices 25 and 26 having the shutter member which can open/close the feeding routes 18, 19, and 20, a case member in which orifices are formed on both sides of the shutter member, and the shutter member is stored, and a negative pressure means 31 which makes the pressure of the internal space of the case member negative. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a material supply device and a method for operating the material supply device.

As a material supply apparatus attached to a plasticizing apparatus provided with a shutter member that opens and closes an opening, those shown in Patent Documents 1 to 3 are known. In Patent Document 1, a rotary valve type shutter device is used for a supply part of a plasticizing device of an injection molding machine. In addition to the large size of the device, high processing accuracy is required for the housing and the rotary valve body. Actually, there were many problems in terms of sealing performance and galling. Further, Patent Document 2 uses a shutter device that rotates in the horizontal direction for a supply unit of a plasticizing device of an injection molding machine. As shown in FIG. 4, a seal is provided between a through hole 5d and a shutter member 3. An O-ring 4A is provided. However, Patent Document 2 has a problem that when the shutter member 3 is rotated, the O-ring 4A wears because the shutter member 3 slides between the O-ring 4A. Further, if the pressing force of the shutter member 3 by the O-ring 4A is weakened to prevent the O-ring 4A from being worn, the resin powder adhering to the upper surface of the shutter member 3 is moved when the shutter member 3 is rotated. 3 and the through-hole 5d, there is a problem that the sealing performance by the O-ring 4A is hindered. Therefore, in order to ensure the sealing performance by the O-ring 4A, there is a problem whether the surface pressure between the O-ring 4A and the shutter member 3 is high or low. In Patent Document 3, the shutter 3 is brought into contact with the seal member to maintain airtightness. However, there is a problem similar to that of the Patent Document 2, and the wear of the seal member 16a during the movement of the shutter 3 is avoided. It was not possible. Further, as described in paragraph (0008) of Patent Document 3, in the conventional shutter device, resin waste or metal powder of the shutter enters the sliding clearance between the shutter and the seal member, and the airtight seal of the shutter is impaired. There were also problems such as opening and closing failure.

JP-A-9-164527 (Claim 2, 0007, FIG. 1) JP 2001-293750 A (Claim 2, 0021, FIG. 1) JP 2002-347073 A (Claim 1, 0019, FIG. 1)

In the present invention, in view of the above problems, in the conventional material supply apparatus, the hermetic seal of the shutter is damaged or the opening / closing failure is caused by the resin powder or the like entering the sliding clearance between the shutter member and the other member. Material supply device and material supply device that solves any of the above problems, or resin powder that has entered, metal powder of shutters, etc., supplied into the heating cylinder, causing burning or reducing the quality of the molded product It aims at providing the operating method of.

The material supply device according to claim 1 of the present invention is a material supply device for supplying a molding material through a supply path into a heating cylinder capable of vacuum suction, and a shutter member capable of opening and closing the supply path, and the shutter. There is provided a shutter device having a case member in which openings are provided on both sides of the member and the shutter member is housed, and a negative pressure means for bringing the internal space of the case member into a negative pressure state. Features.

The material supply device according to claim 2 of the present invention is a material supply device for supplying a molding material to a vacuum-suctionable heating cylinder through a supply path, and a shutter member that can open and close the supply path, and the shutter. A shutter device having a case member in which openings are provided on both sides of the member and the shutter member is housed, and a gas supply means for bringing the internal space of the case member into a gas flow state is provided. Features.

According to a third aspect of the present invention, there is provided the material supply apparatus according to the first or second aspect, wherein a suction port is provided on one side of the case member.

According to a fourth aspect of the present invention, there is provided a method for operating a material supply apparatus, wherein the supply path can be freely opened and closed in the operation method of the material supply apparatus for supplying a molding material through a supply path into a vacuum cylinder capable of vacuum suction. A shutter member is provided, and the shutter member is cleaned by vacuum suction or gas flow in the internal space of the case member in which the shutter member is stored.

The material supply device of the present invention is a material supply device for supplying a molding material through a supply passage into a heating cylinder capable of vacuum suction, and a shutter member that can be opened and closed on both sides of the shutter member. And at least one of a shutter device having a negative pressure means for making the internal space of the case member a negative pressure state or a gas supply means for making a gas flow state. Therefore, problems such as damage to the airtight seal of the shutter or poor opening / closing, or resin powder or shutter metal powder that has entered into the heating cylinder may cause burning or damage to the molded product. At least one of the problems of deteriorating quality can be prevented.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a plasticizing apparatus to which the shutter device of the present embodiment is attached. FIG. 2 is a cross-sectional view of the material supply device of the present embodiment when the shutter device is opened. 3 is a cross-sectional plan view taken along line AA in FIG. FIG. 4 is a cross-sectional view of the material supply device of the present embodiment when the shutter device is closed.

As shown in FIG. 1, a plasticizing device 11 which is an injection device of an injection molding machine is a heating capable of vacuum suction of a molding material M input from a material input device 12 to a material supply device 13 via a material adjusting device 14. The screw 16 supplied to the cylinder 15 and rotationally driven by the screw rotating motor 17 is plasticized by the screw 16 and inserted into the heating cylinder 15, becomes molten material, and is stored inside the front end side of the heating cylinder 15 in front of the screw 16. The stored molten material is injected into a cavity of a molding die attached to a mold clamping device (not shown) by moving the screw 16 forward by driving a screw forward / backward moving means (not shown) to form a molded product. The

The material supply device 13 of the plasticizing device 11 supplies a predetermined amount of the molding material M to the material adjustment device 14 while always making the inside of the material adjustment device 14 and the inside of the heating cylinder 15 have a vacuum structure. The outer shell of the material supply device 13 forms an airtight structure together with the outer shell of the material adjusting device 14 and the outer shell of the heating cylinder 15, and is formed from the material charging device 12 to the material adjusting device 14 inside. A supply path for the material M is formed. The material supply device 13 includes an upper supply path 18, an intermediate supply path 19, a lower supply path 20, an upper shutter device 25 disposed between the upper supply path 18 and the intermediate supply path 19, and an intermediate supply path 19. The lower shutter device 26 is disposed between the lower supply passages 20. The upper supply path 18 includes a glass tube 18a and a ring body 23a. The intermediate supply path 19 includes a glass tube 19a and ring bodies 23b and 24a. The lower supply path 20 includes a glass tube 20a and ring bodies 24b and 27. The glass tubes 18a, 19a, and 20a can visually check the amount of the molding material M inside, and can be detected by the level sensors 21 and 22. The members of the airtight structure including the material supply device 13, the material adjustment device 14, and the heating cylinder 15 are sealed with an O-ring or the like. Further, a hole 33 is formed in the intermediate supply path 19, and an opening / closing valve 35 is disposed in a pipe line 34 connected to the hole 33, and the pipe line 34 is connected to a vacuum pump 31 described later via the pipe line 32. It is connected.

In addition, about the material supply apparatus 13 of the plasticizing apparatus 11, you may supply the molding material M directly to the intermediate supply path 19 using a blower. In that case, the upper shutter device 25 required when the inside of the intermediate supply path 19 is evacuated is provided at another position, and the molding material M may be sent from below to above. The material supply device 13 uses two shutter devices 25 and 26. However, when the molding material M is supplied to the heating cylinder 15, one shutter is provided so that the inside of the heating cylinder 15 communicates with the atmosphere. It may have only a device. Further, at least one of the upper supply path 18, the intermediate supply path 19, and the lower supply path 20 may have a hopper structure with a large volume or a heating device.

The material adjusting device 14 of the plasticizing device 11 controls the rotational speed of the motor 37 that is the driving means of the feed screw 36 so that the amount of the molding material M in the screw 16 groove in the heating cylinder 15 is optimized. The conveyance amount of the molding material M is adjusted. The material adjusting device 14 is not essential, and the material supplying device 13 may be directly attached to the heating cylinder 15.

Next, the structure of the shutter devices 25 and 26 of the material supply device 13 will be described with reference to FIGS. Since the upper shutter device 25 and the lower shutter device 26 have substantially the same structure, the description will focus on the state of FIG. 2 in which the lower shutter device 26 is open.

The shutter device 26 is provided with a case member 41 made of a rectangular parallelepiped as an outer shell. A shutter member 42 is stored in the internal space 28 of the case member 41 so as to be able to reciprocate. The upper surface of the upper plate of the case member 41 is fixed to the ring body 24a of the intermediate supply path 19 with an O-ring interposed therebetween, and the lower surface of the lower plate of the case member 41 is fixed to the ring body 24b of the lower supply path 20 On the other hand, it is fixed with an O-ring interposed. In the upper and lower plates of the case member 41, openings 41a and 41a having the same diameter as the openings of the ring bodies 24a and 24b are formed on both sides (up and down in this embodiment) across the shutter member 42. Has been. An air cylinder 43 is fixed to the other end of the case member 41 to move the shutter member 42 back and forth in the horizontal direction. As shown in FIG. 1, the air cylinder 43 is connected to an air pressure source 45 via an on-off valve 44.

The rod 43 a of the air cylinder 43 is fixed to the shutter member 42. The shutter member 42 is a rectangular metal flat plate having a predetermined plate thickness that has been surface-treated with a material such as chromium or tungsten carbide by a method such as CVD, PVD, or plating. As shown in FIG. 3, the width of the shutter member 42 is substantially the same as the width of the hollow case member 41, and both side surfaces of the shutter member 42 are slidable on the longitudinal inner wall surface of the case member 41. It has become. At the center near the front of the shutter member 42, an opening portion of the ring body 24 a of the intermediate supply path 19 and a through hole 42 a having the same diameter as the opening portion 41 a of the case member 41 are formed. When the opening 41a of the case member 41 and the position of the through hole 42a of the shutter member 42 are partially overlapped, the molding material M falls downward, and the positions of the opening 41a and the through hole 42a are completely different. The shutter device 26 can be closed when it does not overlap.

Between the case member 41 and the shutter member 42, an intermediate member 47 is provided in which an opening 47 a having the same diameter as the opening 41 a of the case member 41 and the through hole 42 a of the shutter member 42 is formed. The intermediate member 47 is attached so as to be fitted into a recess 41b formed in the peripheral portion of the opening 41a on the inner (shutter side) surface of the case member 41. However, since the thickness of the intermediate member 47 is thicker than the depth of the concave portion 41b in the vertical direction, the surface 47b (planar surface) of the intermediate member 47 on the shutter member side is inward of the surface 41c of the case member 41. Protrusively toward. The intermediate member 47 is attached to the upper and lower plates of the case member 41, respectively. The distance between the surface 47b of the intermediate member 47 and the upper and lower surfaces 42b (planes) of the shutter member 42 can be brought into close contact by surface contact to such an extent that leakage exceeding an allowable limit does not occur. The interval is slidable when moving.

The intermediate member 47 is formed of a metal material of the shutter member 42 or a metal material that is less likely to cause galling with the surface treatment material of the shutter member 42, and the surface 47 b of the intermediate member 47 slides on the surface of the shutter member 42. It has a low coefficient of friction when moved and has good adhesion. The intermediate member 47 is not essential to the present invention, and the inner surface of the case member 41 may constitute a sliding surface with the shutter member 42 without providing the intermediate member 47. Further, the intermediate member 47 may be protruded to the outside of the case member 41 and directly connected to the intermediate supply path 19 or the lower supply path 20. In that case, the opening 41 a of the case member 41 is indirectly communicated with the supply path via the intermediate member 47. In any case, the internal space 28 of the shutter device 26 can be kept airtight by the case member 41, the shutter member 42, and the like.

An O-ring 48 is provided between the case member 41 and the intermediate member 47. However, a spring, pneumatic pressure, or hydraulic means may be provided between the case member 41 and the intermediate member 47 so that the intermediate member 47 is pressed toward the shutter member 42. On the inner upper surface of the lower plate of the case member 41, a flat mounting plate 49 made of resin having a low friction coefficient and having a predetermined plate thickness is attached. The upper surface of the mounting plate 49 is slidable with the surface 42b (lower surface) of the shutter member 42. By placing the shutter member 42 slidably on the placement plate 49, a substantially uniform gap can be maintained with respect to the upper and lower intermediate members 47, 47. The mounting plate 49 is not sized to occupy the entire internal space 28 below the shutter member 42.

The upper surface (or the lower surface) on one side of the case member 41 is provided with a dedicated suction port 51 for sucking air in the internal space 28 of the case member 41, and is connected via the lower supply path 20 and the material adjusting device 14 in a vacuum state. Instead of being sucked by vacuum, it is directly connected to a vacuum pump 31 as a vacuum source via a pipe line 52, a pipe line 32, and a filter 30. The upper surface (or lower surface) on the other side of the case member 41 is provided with a supply port 53 for supplying compressed air into the internal space 28 of the case member 41, and gas supply means via a pipe line 54 and an opening / closing valve 55. Is connected to an air pressure source 45. The position where the suction port 51 is provided in the case member 41 is more preferably provided on one side where the through hole 42a of the shutter member 42 is located when the shutter member 42 is closed. However, the suction port 51 may be provided on the other side where the through hole 42a of the shutter member 42 is not located when the shutter member 42 is closed. In this embodiment, what is supplied from the air pressure source 45 is compressed air obtained by compressing the atmosphere with a compressor, but nitrogen gas or the like may be supplied.

The control device 46 receives various signals from the level sensors 21 and 22 and has a built-in timer. The control device 46 transmits signals to the material input device 12, the screw rotation motor 17 and the feed screw 36 motor 37, the vacuum pump 31, the air pressure source 45, the open / close valves 35, 44, 44, 55, 55, and the like. Control is possible. The control device of the injection molding machine and the control device of the material supply device 13 may be the same or separated, but exchange of signals with the control device on the injection molding machine side is necessary even if the control device is separated.

Next, the operation of the material supply device 13 and the shutter devices 25 and 26 will be described. The state shown in FIG. 1 is a state in which the shutter device 25 at the top of the material supply device 13 is opened and the molding material M is dropped into the intermediate supply path 19. At this time, the shutter device 26 below the material supply device 13 is closed. And the airtight structure comprised from the heating cylinder 15, the material adjustment apparatus 14, the lower supply path 20, etc. is always attracted | sucked by the vacuum pump 31 which is a negative pressure means via the pipe line 32 grade | etc.,. Further, the internal space 28 of the case member 41 of the shutter devices 25 and 26 is also sucked by the vacuum pump 31 through another pipe 52. Next, the upper shutter device 25 is closed. The shutter device 25 is closed by operating the air cylinder 43 so that the shutter member 42 is advanced to the position indicated by the alternate long and short dash line in FIG. 3, and at the same time, the through hole 42a of the shutter member 42 that coincides with the openings 41a and 47a is forward. The openings 41a and 47a are closed by a plate portion closer to the rear of the shutter member 42. At this time, the surfaces 42b and 42b of the shutter member 42 are partly supported by the mounting plate 49 and are moved so as to be in contact with the surfaces 47b and 47b of the upper and lower intermediate members 47 and 47. Very unlikely to occur. Further, since the shutter member 42 and the intermediate member 47 are in a sliding state with appropriate pressure, the biting of resin powder or the like contained in the molding material M can be suppressed as much as possible.

Next, the on-off valve 35 is opened, and the atmosphere in the intermediate supply path 19 is sucked to evacuate the intermediate supply path 19. When the molding material M is supplied from the material adjusting device 14 to the heating cylinder 15 together with the continuous molding and the molding material M in the lower supply path 20 decreases, and the level sensor 22 becomes unable to detect the molding material M, the lower shutter device. 26 is opened, and the molding material M in the intermediate supply path 19 is dropped into the material adjusting device 14 and the lower supply path 20. The timing for opening the lower shutter device 26 may be set by a timer. Further, during the above operation, the next molding material M is supplied to the upper supply path 18 above the upper shutter device 25 closed from the material charging device 12, and supplied when the level sensor 21 senses the molding material M. Is stopped. When the lower shutter device 26 is closed again, the upper shutter device 25 is then opened, and the molding material M in the upper supply path 18 is dropped into the intermediate supply path 19. As a result, the state of FIG. 1 is obtained again, and the same cycle is repeated.

In the present embodiment, the internal space 28 composed of a space in which the shutter member 42 of the case member 41 reciprocates and a space around it is provided with a suction port 51, a pipe line 52, and a pipe line 32 provided on one side of the case member 41. Since the vacuum pump 31 is always operated, the internal space 28 is always in a negative pressure state. Accordingly, no leakage occurs even when the shutter member 42 is moved. Conventionally, when the internal space 28 is at atmospheric pressure, atmospheric pressure is applied to the outer portion of the intermediate member 47 outside the O-ring 48, so that a strong pressure is applied from the intermediate member 47 toward the shutter member 42. It was. However, in the present embodiment, the internal space 28 is brought into a vacuum state (negative pressure state), so that the pressurization by the intermediate member 47 can be reduced. Further, since the internal space 28 is in a vacuum state, the O-ring 48 can have a low hardness. Accordingly, the pressure applied by the O-ring 48 from the intermediate member 47 toward the shutter member 42 can be reduced, and the generation of metal powder accompanying the sliding wear of the shutter member 42 can be suppressed.

Then, after the opening and closing operations of the shutter member 42 are completed by a signal from the control device 46, the internal space is opened from the air pressure source 45 through the supply port 53 by opening the on-off valve 55 for about 0.5 seconds, for example. Compressed air is supplied to 28. Since the suction port 51 is sucked by the vacuum pump 31 in the internal space 28, most of the supplied compressed air passes between the case member 41 and the shutter member 42 as shown by the arrows in FIG. And sent to the suction port 51. A part is also sent between the shutter member 42 and the intermediate member 47. As described above, when the internal space 28 is in a gas flow state, the resin dropped into the case member 41 from between the shutter member 42 and the intermediate member 47 (or the case member) by the opening operation and the closing operation of the shutter member 42. Powder and metal powder are collected. Since the compressed air is supplied for a short time and is always vacuumed, the internal space 28 remains almost in a negative pressure state. Since the resin powder and metal powder collected from the suction port 51 are collected by the filter 30, they are not discharged from the vacuum pump 31 to the outside.

The timing of introducing the compressed air from the air pressure source 45 is not limited to the above, and may be after the shutter member 42 is moved a plurality of times or every predetermined time. Further, the shutter member 42 may be moving. The introduction of compressed air from the air pressure source 45 is not indispensable, only the suction port 51 is provided in the case member 41 without providing the supply port 53, and the internal space 28 of the case member 41 is always provided in a negative pressure state. May be. Even if the internal space 28 of the case member 41 is in a negative pressure state, a certain effect can be expected in the collection of resin powder and metal powder. And since it is possible to make low the pressurization between the shutter member 42 and the intermediate member 47, the metal powder by friction can be reduced. Further, a gas flow state may be established by flowing gas from the supply port 53 and discharging it from another discharge port without making the internal space 28 of the case member 41 of the shutter devices 25 and 26 negative pressure.

The present invention is not limited to the embodiments described above, and various modifications can be added and implemented without departing from the spirit of the invention. The shutter member of the shutter device may be one in which the through hole communicates with the supply path by advancing, or may be a single plate having no through hole. Further, the shutter member of the shutter device may be one that moves in the vertical direction or diagonal direction other than the one that reciprocates in the horizontal direction, or one that the flat plate rotates around one point. Further, the shutter member may be rotated as in Patent Document 1. Further, the direction in which the molding material is supplied may be one that is sent in the horizontal direction or one that is sent from below to above. In all of these shutter devices, the resin powder and the sliding powder of the shutter member can be collected by suctioning the space between the shutter member and the surrounding case member under a negative pressure or bringing the gas into a gas flow state.

Furthermore, as a plasticizing device to which the shutter device of the present invention is attached, in addition to a uniaxial type injection molding machine, a pre-plastic (registered trademark) type injection molding machine in which the plasticizing device and the injection device are separated, an extruder, a kneading machine The material is not limited to resin, and other organic materials, inorganic materials, metal materials, etc. may be used.

It is sectional drawing of the plasticizing apparatus to which the shutter apparatus of this embodiment was attached. It is sectional drawing at the time of opening of the shutter apparatus of this embodiment. It is a plane sectional view of the AA line in FIG. It is sectional drawing at the time of closing of the shutter apparatus of this embodiment.

Explanation of symbols

11 Plasticizing device 13 Material supply device (supply path)
15 Heating cylinder 25, 26 Shutter device 28 Internal space 31 Vacuum pump (negative pressure means)
41 Case member
41a, 47a Opening 42 Shutter member 45 Air pressure source (gas supply means)
47 Intermediate member 51 Suction port 53 Supply port

Claims (4)

In a material supply device for supplying a molding material through a supply path into a vacuum tube capable of vacuum suction,
A shutter member capable of opening and closing the supply path;
A case member having openings on both sides of the shutter member and storing the shutter member;
A material supply device, comprising: a shutter device having a negative pressure means for setting the internal space of the case member to a negative pressure state. In a material supply device for supplying a molding material through a supply path into a vacuum tube capable of vacuum suction,
A shutter member capable of opening and closing the supply path;
A case member having openings on both sides of the shutter member and storing the shutter member;
A material supply device, comprising: a shutter device having a gas supply means for bringing the internal space of the case member into a gas flow state. The material supply device according to claim 1, wherein a suction port is provided on one side of the case member. In the operation method of the material supply device for supplying the molding material through the supply path into the heating cylinder capable of vacuum suction,
A shutter member capable of opening and closing the supply path is provided;
A method for operating a material supply apparatus, wherein the shutter member is cleaned by vacuum suction or gas flow in the internal space of the case member in which the shutter member is stored.

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