JP4730843B2 - Raw material supply device for injection molding machine - Google Patents

Description

  The present invention relates to a raw material supply apparatus that supplies a forming raw material to a heating cylinder of an injection molding machine.

  A resin raw material supply apparatus installed at a raw material inlet of a heating cylinder of a synthetic resin molding machine comprising a screw and a casing, the raw material storage means having a damper device, and the raw material storage means receiving the raw material from the raw material storage means For example, Patent Document 1 discloses a raw material supply apparatus including an automatic supply device having a raw material charging cylinder portion that supplies a raw material charging port and an air suction source that sucks and decompresses the inside of the raw material charging cylinder portion. . And the charge tank as a raw material storage means divided up and down freely by the damper apparatus consists of a transparent cylinder.

  In such a raw material supply device, the fine powder of the raw material is easily attached to the charge tank, and it mixes with the resin raw material and causes molding defects, so sometimes air blows with compressed air to remove the fine powder etc. There is a need to. At this time, the charge tank is closed with a damper device or closed with a resin material to become airtight, and the exhaust passage is closed with an on-off valve. For this reason, the inside of the charge tank is pressurized with compressed air, and the glass cylinder, which is a transparent cylinder, may be damaged.

JP 2006-35489 A

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a raw material supply device for an injection molding machine that can be operated safely.

The present invention provides a raw material supply apparatus for supplying a molding raw material to a heating cylinder of an injection molding machine, to an on-off valve that opens and closes a passage of compressed air that blows into the cylindrical body where the passage or deposition state of the molding raw material is visible. The control device that outputs the signal by controlling the sequence is an injection molding having an interlock that prevents the opening / closing valve from being opened when the shutter that partitions the cylindrical body is not open in the sequence control of the cleaning process other than the molding process. The present invention relates to a raw material supply device for a machine.

  According to the raw material supply apparatus of the present invention, the injection molding machine can be operated safely.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a raw material supply apparatus of the present invention together with a main part of an injection molding machine.

  The injection molding machine 1 supplies the molding raw material 17 put into the hopper cylinder 18 to the heating cylinder 4 via the raw material supply apparatus 2 and the raw material adjustment apparatus 3, and the screw 5 fitted in the heating cylinder 4 is screw driving means. 6 is rotated and plasticized to become a molten material, which is stored inside the tip of the heating cylinder 4 in front of the screw 5. The stored molten material is injected into a mold (not shown) by the forward movement of the screw 5 by the screw driving means 6 to form a molded product.

  The raw material supply device 2 supplies a predetermined amount of the forming raw material 17 to the raw material adjusting device 3 while hermetically blocking the inside of the lower cylindrical body 10 that is the passage of the forming raw material 17 on the heating tube 4 side. The raw material supply device 2 is a part of the passage of the forming raw material 17 from the hopper cylinder 18 through the raw material adjustment device 3 to the heating cylinder 4, and the lower cylinder 10 attached to the upper surface of the raw material adjustment device 3, The upper cylinder 9 is attached to the upper surface of the lower cylinder 10 via the lower shutter 16, and the hopper cylinder 18 is attached to the upper surface of the upper cylinder 9 via the upper shutter 15. The upper cylindrical body 9, the lower cylindrical body 10, and the hopper cylindrical body 18 are transparent cylindrical bodies that allow the passage and deposition state of the molding raw material 17 to be visually observed. The cylindrical body which is a glass cylinder is preferable at the point which avoids a scar. Air inlets 21 and 22 and air outlets 25 and 26 are provided on the upper side surfaces of the upper cylinder body 9 and the lower cylinder body 10 at positions different from the side surface positions where the air inlets 21 and 22 are provided. . A compressed air source 23 is connected to the air inlets 21 and 22 via on-off valves 30 and 31. Further, a pressure air valve such as a pressure reducing valve 35 or a pressure adjusting valve is provided in a pipe line between the pressure air source 23 and the on-off valves 30 and 31. 9 and the inside of the lower cylinder 10 are reduced to a pressure that can be cleaned. The pipe connected to the air outlet 25 branches and connects the check valve 27 via the filter 36 so that the forward direction is the atmosphere, and is connected to the vacuum source 29 which is a vacuum pump via the on-off valve 32. Has been. The pipe connected to the air outlet 26 branches and connects the check valve 28 through the filter 36 so that the forward direction is the atmosphere, and is connected to a vacuum source 29 which is a vacuum pump. The filter 36 prevents the check valves 27 and 28 from becoming defectively sealed due to dust in the cylinders such as the upper cylinder body 9 and the lower cylinder body 10, and is not essential. The compressed air valve may be provided in a pipe line through air outlets 25 and 26 and check valves 27 and 28 for the atmosphere. In particular, it is more preferable to provide a pneumatic valve on the atmosphere side of the check valves 27 and 28 in terms of pneumatic control. Furthermore, although both the pneumatic valve and the check valves 27 and 28 may be provided, only one of them that is more effective in terms of cost, attachment state, or the like may be provided.

  The raw material adjusting device 3 is formed from the raw material supply device 2 so that the amount of the forming raw material 17 in the screw 5 groove in the heating cylinder 4 is in an optimum state according to the type and forming state of the forming raw material 17. The conveyance amount of the raw material 17 is adjusted by controlling the rotation speed of the feed screw 7 with the feed screw driving means 8. The suction hole 24 provided in the raw material adjusting device 3 is connected to a vacuum source 29 so that air and gas components inside the heating cylinder 4 can be effectively sucked by a vacuum pump (not shown). The raw material adjusting device 3 is not essential, and the raw material supply device 2 may be directly attached to the heating cylinder 4.

  Next, the operation of the raw material supply apparatus 2 will be described. The control device 33 controls the shutter driving means 13 and 14 to close the upper shutter 15 and the lower shutter 16. The vacuum source 29 is always operated, the on-off valves 30 and 31 are closed, and the on-off valve 32 is controlled to be opened. And since the rear end surface of the heating cylinder 4 is sealed with a sealing member 37 such as U-packing, and the front part of the heating cylinder 4 is sealed with a molten material, the inside of the heating cylinder 4, the raw material adjusting device 3 and The inside of the upper cylinder 9 and the lower cylinder 10 of the raw material supply apparatus 2 is evacuated. As the molding process of the injection molding machine 1 proceeds and the molding raw material 17 in the raw material adjusting device 3 is plasticized and consumed, the level sensor 20 provided on the side surface of the lower cylinder 10 causes the shortage of the molding raw material 17. Detect. When the level sensor 20 no longer detects the molding material 17, the lower shutter 16 is opened, and the molding material 17 deposited on the upper surface of the lower shutter 16 in the upper cylindrical body 9 is dropped and supplied to the material adjusting device 3. At this time, since the upper and lower surfaces of the lower shutter 16 are vacuum and have the same pressure, the lower shutter 16 can easily slide without being pressed against one side.

  Then, after closing the lower shutter 16 and closing the on-off valve 32, the on-off valve 30 is opened and relatively low-pressure compressed air is blown into the upper cylinder 9 for a predetermined time, so that the check valve 27 or the pneumatic valve Exhaust from. Thereby, the vacuum in the upper cylinder 9 is released, and dust such as fine powder in the upper cylinder 9 is removed. In this manner, the check valve 27 or the pneumatic valve acts so as not to increase the pressure in the upper cylinder 9 to the pressure of the pressurized pneumatic source 23, and prevents the glass upper cylinder 9 from being damaged. Moreover, since the transparent resin film 11 is laminated | stacked on the outer surface of the upper cylinder 9, or it is coat | covered with the transparent cylindrical resin board, even when the upper cylinder 9 should be damaged by any chance No debris will scatter. The resin film 11 may simply be a food wrapping film, but is preferably a transparent PET or polycarbonate film having a thickness of 100 micrometers or more.

  After the vacuum in the upper cylinder 9 is released, the upper shutter 15 is opened, and the molding material 17 deposited on the upper surface of the upper shutter 15 in the hopper cylinder 18 is dropped into the upper cylinder 9. Supply. At this time, since the upper and lower surfaces of the upper shutter 15 are atmospheric pressure and substantially the same pressure, the upper shutter 15 can be easily slid without being pressed against one side. And after closing the upper shutter 15 and closing the on-off valve 30, the on-off valve 32 is opened and the inside of the upper cylinder 9 is evacuated again. Further, since the level sensor 19 detects that there is no molding material 17 in the hopper cylinder 18, a predetermined amount of the molding material 17 is supplied to the hopper cylinder 18 in preparation for the next supply process of the material supply device 2. Accumulated.

  By the way, while the upper cylindrical body 9 is cleaned during the supplying process of the forming raw material 17 accompanying the molding process of the injection molding machine 1 as described above, the lower cylindrical body 10 is cleaned during the supplying process. I can't. Therefore, the cleaning inside the lower cylindrical body 10 can be performed alone when it is not the supply process of the forming raw material 17. Further, the cleaning inside the upper cylindrical body 9 can be performed in the same manner as the cleaning inside the lower cylindrical body 10 even when the forming raw material 17 is not supplied. Further, the inside of the sliding portion of the upper shutter 15 and the lower shutter 16 and the hopper cylinder 18 can be air blown.

  That is, when cleaning the inside of the lower cylinder 10, the vacuum suction function is stopped based on the command signal of the control device 33, the lower shutter 16 is opened, the on-off valve 31 is opened, and the lower cylinder 10 is opened. Supply compressed air. The compressed air is discharged into the atmosphere from the check valve 28 or the compressed air valve together with dust such as fine powder. As described above, the check valve 28 or the pneumatic valve acts so as not to increase the pressure in the lower cylinder 10 to the pressure of the pressurized pneumatic source 23, and prevents the glass lower cylinder 10 from being damaged. Moreover, since the resin film 12 is laminated | stacked on the outer surface of the lower cylinder body 10, or is coat | covered with the transparent cylindrical resin board, even if the lower cylinder body 10 should be broken, a debris will be generated. There is no scattering. The resin film 12 may simply be a food wrapping film, but is preferably a transparent PET or polycarbonate film having a thickness of 100 micrometers or more. In addition, when the dirt of the upper cylinder body 9, the lower cylinder body 10, or the hopper cylinder body 18 is severe, they may be disassembled and cleaned individually. At that time, they may be damaged by mishandling. The resin films 11 and 12 exhibit a protective effect even in such a situation.

  The sequence control of the control device 33 in the cleaning process as described above will be described. When the cleaning mode for performing the cleaning process is selected and set by the operation unit of the control device 33, the control device 33 stops the vacuum suction function by closing the on-off valve 32 or stopping the operation of the vacuum source 29. At the same time, the control device 33 transmits a signal to the pneumatic switching valve that operates the shutter driving means 13 and 14 that are pneumatic cylinder devices so as to drive the upper shutter 15 and the lower shutter 16 to the open side. Then, the control device 33 confirms the confirmation signal from the proximity switch or the like that detects that the shutter opening signal is transmitted and that the pneumatic cylinder device does not close or open the shutter. And a signal for opening the on-off valves 30 and 31 are transmitted. Further, when the control pressure of the pressure sensor 34 provided in the pipe line connected to the air outlet 25 of the upper cylinder 9 rises to a predetermined value or more that may cause the upper cylinder 9 to be destroyed, The on-off valves 30, 31 and the like are forcibly closed, and the air pressure switching valve is operated to open the upper shutter 15.

  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. For example, in the above-described embodiment, the inside of the heating cylinder 4 has been described as being depressurized. However, an inert gas source such as nitrogen is connected to the heating cylinder 4 instead of the vacuum source 29, and the inside of the heating cylinder 4 is inert. In some cases, pressure is filled with gas to prevent oxidation of the molten material. Even in that case, the inventions according to claim 1, claim 3, claim 4 and 5 other than claim 2 are effective and have a remarkable effect that the injection molding machine can be operated safely. .

It is a longitudinal cross-sectional view which shows the raw material supply apparatus of this invention with the principal part of an injection molding machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection molding machine 2 Raw material supply apparatus 3 Raw material adjustment apparatus 4 Heating cylinder 5 Screw 6 Screw drive means 7 Feed screw 8 Feed screw drive means 9 Upper cylinder 10 Lower cylinder 11, 12 Resin film 13, 14 Shutter drive means 15 Above Shutter 16 Lower shutter 17 Molding raw material 18 Hopper cylinder 19, 20 Level sensor 21, 22 Air inlet 23 Pressure air source 24 Suction hole 25, 26 Air outlet 27, 28 Check valve 29 Vacuum source 30, 31, 32 Open / close valve 33 Control Device 34 Pressure sensor 35 Pressure reducing valve 36 Filter 37 Sealing member

Claims (2)

In the raw material supply device that supplies the molding raw material to the heating cylinder of the injection molding machine,
The control device for controlling and outputting a signal to the on-off valve that opens and closes the passage of the compressed air that blows into the inside of the cylindrical body in which the molding raw material is visible or accumulated can be controlled by the sequence control of the cleaning process other than the molding process. Then, the raw material supply apparatus for an injection molding machine has an interlock which prevents the opening / closing valve from being opened when the shutter for partitioning the cylindrical body is not open. 2. The raw material supply device for an injection molding machine according to claim 1, wherein the outer surface of the cylindrical body in which the passage or deposition state of the molding raw material is visible is covered with a resin film or a resin plate.

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