JP4500286B2 - Resin drying method - Google Patents

Description

The present invention relates to a resin drying method used for drying resin pellets before resin molding.

  Conventionally, when moisture is contained in resin pellets, which are molding materials for resin molding, the moisture is vaporized by heating at the time of molding, and the quality of molded products is deteriorated and defective products are generated. Therefore, the drying process is performed to the resin pellet which should be supplied to an injection molding machine before shaping | molding. Although this drying treatment is based on heating, if the heating temperature exceeds 100 ° C., which is the evaporation temperature of moisture, there may be inconveniences such as color change in the resin pellets. For this reason, conventionally, in the drying process of resin pellets, the resin pellets are heated under a certain reduced pressure to prevent deterioration such as a change in color tone.

Regarding such resin drying, Patent Document 1 discloses dehumidifying the resin under reduced pressure, Patent Document 2 discloses automatically supplying a molding material to an injection molding machine, and Patent Document 3 discloses. Discloses the drying of resin pellets for an injection molding machine, and Patent Document 4 discloses the history management of equipment.
Japanese Patent Application Laid-Open No. 06-114834 Japanese Patent Laid-Open No. 06-344383 JP-A-10-272387 International Publication No. 99/001806 Pamphlet

  By the way, resin molding is a continuous process, and continuous supply of resin necessary for molding is indispensable. If the resin drying apparatus is stopped due to a failure of a part or the like, the stop significantly hinders the productivity of resin molding.

  Accordingly, an object of the present invention is to provide a resin drying method in which productivity of resin supply and resin molding is improved.

Another object of the present invention is to improve the efficiency of resin supply and resin molding by predicting the arrival of a failure from the accumulated time or number of times of drying processing to improve the efficiency of parts replacement and the like.

  The resin drying method of the present invention is a resin drying method for drying a resin (resin pellet 2) to be supplied to an injection molding machine (10), and is a resin drying process, a decompression process, a heating process, a replenishment process, and a supply process. Etc., and the number of times and time of use of the means (drying treatment tank 4, blower 18, heater 60, heat pipe 62, vacuum pump 70, etc.) are limited. Manages the number of times of integration, and displays and alerts it to predict the arrival of a failure from the accumulated time or number of times of drying processing to make parts replacement more efficient and avoid inconveniences such as an emergency stop of the injection molding machine and supply resin And productivity of resin molding can be improved.

A first aspect of the present invention is a resin drying method for drying a resin in conjunction with an injection molding machine and supplying the dry resin to the injection molding machine according to the resin molding of the injection molding machine . According to the process of putting the resin into the drying treatment tank, the step of reducing the pressure of the drying treatment tank, the step of heating the resin in the drying treatment tank under reduced pressure, and the resin consumption of the injection molding machine, In addition to the first opening / closing means in the connecting portion between the storage tank for storing the resin discharged from the drying treatment tank and the drying treatment tank, the connecting portion with a space between the first opening / closing means. And opening the second opening / closing means in the step of transferring the resin in the drying treatment tank from the discharge port of the drying treatment tank to the storage tank through the connecting portion, and transferring the resin to the storage tank. Thereafter, the first opening / closing means is closed, and this Serial closing the second switching means from the time of closing the first switching means after a predetermined time, the injection molding comprising the steps of the drying tank in a sealed state, the resin in said reservoir from said reservoir And a step of supplying the resin to be dried to the drying tank. With this configuration, the above object is achieved.

A second aspect of the present invention is a resin drying method for drying a resin in conjunction with an injection molding machine and supplying the dry resin to the injection molding machine in accordance with the resin molding of the injection molding machine . The step of putting the resin into the drying treatment tank, the step of reducing the pressure of the drying treatment tank, the step of heating the resin in the drying treatment tank under reduced pressure, and the resin dried in the drying treatment tank A step of supplying to the injection molding machine, a step of supplying the resin to be dried to the drying treatment tank, a decompression of the drying treatment tank, a heating of the resin, and a drying treatment tank of the resin from the drying treatment tank to the injection molding machine. Adding the operation time or the number of operations related to the replenishment of the resin or supplying the resin to the drying treatment tank, storing the integration time or the number of operations in a storage means, and the integration number or the integration time. Reached a certain value If a configuration including a step of notifying it to. With this configuration, the above object is achieved. That is, by notifying that the number of integrations or the integration time has reached a preset value, the user can know the arrival time of a failure, part replacement, or the like.

  By the way, in the drying processing apparatus which implements such a resin drying method, airtightness is required for the drying processing tank in which the resin is put, and the decompression means is a vacuum pump (70), a piping system (venting pipe 72), a pressure switch (76). ) Etc., the heating means is provided with a heater (60), etc., and the replenishing means is a pellet tank (6), blower (18), piping system (supplementing pipe 14, suction pipe 20), on-off valve (22, 32), etc. The supply means includes a storage tank (8), a blower (18), a piping system (supply pipe 112), an on-off valve (30, 32, 116), etc., and the control means (control device 200) includes various sensors ( Temperature sensors 58, 66, 68, pressure switch 76, proximity sensors 42, 44, 46, 98, 100, 102, 104, 120), storage means (RAM 212, ROM 214, EEPROM 216) and the like. Is composed of various functional components such as exhausted. For this reason, the frequency | count of use and use time of each functional component containing a drying processing tank are limited, and naturally it has a lifetime. If the use is continued until the end of the service life, one of the parts breaks down and the resin drying apparatus is stopped. Therefore, if the operation time or the number of operations of the drying treatment tank, decompression unit, heating unit, replenishment unit or supply unit is integrated and the integration time or integration number is stored, the occurrence of failure is predicted from the integration time or integration count. In addition, it is possible to set the replacement time of parts, to avoid the occurrence of inconveniences such as an emergency stop of the injection molding machine during the molding process, and to increase the productivity of resin injection molding.

  In the resin drying method of the present invention, the integration time or the integration count may include an integration of an operation time or an operation count of a functional component that performs each control of drying, decompression, replenishment, or supply of the resin. . The above object can also be achieved by such a configuration.

  That is, the drying processing tank, the pressure reducing means, the heating means, the replenishing means, the supplying means, and the control means are provided with various functional parts, and the operation time or the number of times of the functional parts may be integrated. It is also possible to set the replacement time, avoiding the occurrence of inconveniences such as an emergency stop of the injection molding machine during the molding process, and improving the productivity of resin injection molding.

  The resin drying method of the present invention may include a step of displaying the number of times of integration or the time of integration. The above object can also be achieved by such a configuration. That is, the failure occurrence time can be predicted from the actual working time by notifying the user of the number of times of accumulation and the accumulated time.

  The resin drying method of the present invention may include a step of detecting a failure of a specific functional component and storing the failed functional component and the accumulated time or the accumulated number of times when the failure occurs in a storage unit. The above object can also be achieved by such a configuration. That is, if a specific functional part fails, the next replacement time of the functional part can be predicted by storing the accumulated time or number of times until the failure, and the injection molding machine can be used during the molding process. The occurrence of inconvenience such as an emergency stop can be avoided.

  Moreover, in the resin drying method of this invention, it is good also as a structure including the process which memorize | stores abnormality history and displays the abnormality history. The above object can also be achieved by such a configuration. That is, the control means stores the history of occurrence of abnormalities such as malfunctions of functional parts, etc., and displays the abnormal history, which can be used to predict the timing of occurrence of abnormalities such as malfunctions of functional parts and the replacement time. Can do.

The resin drying method of the present invention may include a step of monitoring the presence or absence of the resin in the drying treatment tank and stopping the drying operation when there is no resin. The above object can also be achieved by such a configuration.

  As described above, according to the present invention, the following effects can be obtained.

  a Productivity of resin supply and resin molding can be improved.

  b Accumulate and store the operation time or number of operations, and the failure occurrence time can be predicted by the accumulated time or number of accumulations, the occurrence of failure can be prevented by prior maintenance, and the arrival of failure from the accumulated time or number of times of drying processing Therefore, it is possible to improve the efficiency of parts replacement and the like, and to improve the productivity of resin supply and resin molding.

  c Storage of individual integration times and integration counts for functional parts makes it possible to predict the failure occurrence time more precisely, prevent occurrence of failure by prior maintenance, and improve the productivity of resin injection molding.

  d Integration time and number of integration can be confirmed by visual or audible display, and the failure occurrence time can be easily known.

e The history of failure occurrence can be stored and displayed, the failure occurrence time can be predicted, and the occurrence of unexpected situations can be prevented.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

  FIG. 1 shows a resin drying apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 show a lower part of the drying treatment tank. In this resin drying apparatus, resin pellets 2 which are resins to be dried are guided from a pellet tank 6 to a drying treatment tank 4, and dried resin pellets 2 are supplied from a storage tank 8 to the injection molding machine 10 side.

  A hopper 12 as a replenishing tank for storing the resin pellets 2 to be replenished to the drying treatment tank 4 is provided on the upper part of the drying treatment tank 4 for storing the resin pellets 2 to be dried. The hopper 12 is connected to the pellet tank 6 via a supply pipe 14, and a suction unit 16 for sucking outside air is provided in the middle of the supply pipe 14. The hopper 12 is connected to a blower 18 serving as an air supply / intake unit via a suction pipe 20. An opening / closing valve 22 and a filter 24 are provided in the middle of the suction pipe 20, and an air supply pipe 26 is provided on the exhaust side of the blower 18. The exhaust pipe 28 and the opening / closing valves 30 and 32 are provided. That is, the pellet tank 6 and the blower 18 constitute a replenishing means for the resin pellet 2 to the drying treatment tank 4. Therefore, if the on-off valve 30 is closed, the on-off valves 22 and 32 are opened to form a ventilation path, and the blower 18 is driven to make the inside of the hopper 12 have a negative pressure, air flows into the supply pipe 14 through the aspirator 16. The resin pellet 2 is sucked from the pellet tank 6 and loaded into the hopper 12. Arrows a, b, and c indicate the air flow, and d indicates the resin pellet 2 and the air flow.

  An opening / closing mechanism 34 is provided below the hopper 12, and the resin pellet 2 is supplied to the drying treatment tank 4 in accordance with the opening / closing of the opening / closing mechanism 34. The opening / closing mechanism 34 includes an opening / closing plate 38 using the air cylinder 36 as a driving means, and the movement of the opening / closing plate 38 blocks or opens the hopper 12 and the connecting cylinder 40 via the opening / closing mechanism 34. An arrow e indicates the moving direction of the opening / closing plate 38. The movement of the opening / closing plate 38 is detected by proximity sensors 42 and 44 as opening / closing detection means. The connecting cylinder 40 is a supporting means for supporting the hopper 12 to the drying treatment tank 4 via the opening / closing mechanism 34, and a proximity sensor 46 is provided on the peripheral surface as a means for detecting the resin pellet 2.

  The drying treatment tank 4 has a cylindrical shape with a conical bottom surface in order to guide the resin pellet 2 downward, and includes an inner tank 50 inside the exterior body 48. In the inner tank 50, as a means for uniformly dispersing the resin pellets 2 to be replenished in the drying treatment tank 4, the first stratifier 52 and the resin pellets 2 fall from only the central portion of the drying treatment tank 4 and the surroundings In order to prevent the inconvenience that the portion remains, a second stratifier 54 is provided as a means for uniformly holding the resin pellet 2 in the drying treatment tank 4. Each of the stratifiers 52 and 54 is connected in the vertical direction, and a temperature sensor 58 is attached to the peripheral surface portion of the connecting cylinder 56. A plurality of heaters 60 and heat pipes 62 are installed as heating means for the resin pellets 2 in the inner tank 50, heaters 64 are provided as heating means on the outer surface of the inner tank 50, and wall surfaces are provided on the inner wall surface of the inner tank 50. Temperature sensors 66 and 68 for detecting the temperature are installed. Further, the outer surface portions of the respective stratifiers 52 and 54 constitute a heat conducting surface.

  The inner tank 50 is connected to a vacuum pump 70 as a decompression unit of the drying treatment tank 4 through a vent pipe 72, and the vent pipe 72 is provided with a filter 74 and a pressure switch 76. The pressure switch 76 monitors the depressurized state in the drying treatment tank 4 and generates a switch output indicating the depressurized state when the pressure switch 76 shifts to a predetermined depressurized state. An arrow f indicates the discharge of air during decompression. A vacuum breaker valve 78 is connected to the inner tank 50 via a vent pipe 80. When the vacuum breaker valve 78 is turned on, the drying treatment tank 4 returns to atmospheric pressure due to the inflow of outside air.

  A storage tank 8 is provided at a discharge port 82 of the drying treatment tank 4 via a connecting portion 84. As shown in FIGS. 2 and 3, the connecting portion 84 includes opening and closing plates 88 and 90 as first and second opening / closing means, and an O between the opening / closing support body 85 and the inner wall portion of the connecting portion 84. Rings 87 and 89 are provided to maintain airtightness.

  As shown in FIG. 2, the opening / closing support body 85 is formed with a notch recess 91 as a recess for opening the discharge port 82 to bite the resin pellet 2, and when the opening / closing plate 88 is closed. The end surface portion side hits the lower side of the notch recess 91, and the resin pellet 2 enters the inside of the notch recess 91, thereby preventing the fall.

  A space 92 is formed between the opening and closing plates 88 and 90 inside the opening and closing support 85. The opening / closing plate 88 uses the air cylinder 94 and the opening / closing plate 90 uses the air cylinder 96 as driving means to individually open and close the connecting portions 84. The movement of the opening / closing plate 88 is individually detected by the proximity sensors 98 and 100 as opening / closing detection means, and the movement of the opening / closing plate 90 is individually detected by the proximity sensors 102 and 104 as opening / closing detection means. An arrow g indicates opening / closing movement of the opening / closing plate 88, and h indicates opening / closing movement of the opening / closing plate 90. The space 92 formed between the opening and closing plates 88 and 90 is provided with a leak pipe 106 that leaks air to the inside. The leak pipe 106 is opened and closed by a leak valve 108, and the outside air inflow amount is adjusted. The inside of the drying treatment tank 4 can be adjusted to a predetermined pressure. Arrow i indicates the inflow of air.

  The opening / closing plate 88 constitutes a measuring means for setting the amount of the resin pellets 2 to be dropped depending on the opening time. Also, as shown in FIG. 3, the opening / closing plate 90 is dried through the connecting portion 84 when closed. The discharge port 82 of the tank 4 is sealed and functions as an airtight holding means. That is, the opening and closing plates 88 and 90 both have a function of opening and closing the discharge port 82, the former restricts the passage of the resin pellet 2 and the latter performs airtight holding, and shares the opening and closing function. .

  The storage tank 8 is connected to a hopper 110 on the injection molding machine 10 side via a supply pipe 112 and is connected to a blower 18 through an air supply pipe 26. That is, the blower 18, the supply pipe 112, and the like constitute supply means for supplying the resin pellet 2 in the drying treatment tank 4 to the injection molding machine 10. The hopper 110 and the suction side of the blower 18 are connected through an intake pipe 114, and an open / close valve 116 is provided in the intake pipe 114. That is, by closing the on-off valves 22 and 32 and opening the on-off valves 30 and 116, a closed circuit is formed through the supply pipe 112 and the intake pipe 114, and when the blower 18 is driven, the resin pellets 2 dried from the storage tank 8 are dried. Is introduced into the hopper 110 and loaded. A resin tank 118 is provided below the hopper 110, and the resin pellets 2 are supplied from the hopper 110 to the resin tank 118 for resin molding. Arrows j and l indicate air, and arrow k indicates the resin pellet 2 and the flow of air. The resin tank 118 is provided with a proximity sensor 120 that is detection means for detecting the presence or absence of the resin pellet 2.

  Next, FIG. 4 has shown the control part of the resin drying apparatus. That is, the control unit controls the drying process of the drying process tank 4, the replenishment of the resin pellets 2 to the drying process tank 4, the supply of the resin pellets 2 from the drying process tank 4 to the injection molding machine 10, and the drying process. Tank 4, vacuum pump 70 as decompression means, heater 60 and heat pipe 62 as heating means, pellet tank 6 and blower 18 as supply means for resin pellet 2, etc., blower 18 and supply pipe 112 as supply means The operation time or the number of operations is integrated, and the integration time or the number of operations is stored. The control unit is provided with a control device 200 as a control means using a microcomputer, and the control device 200 is provided with a control arithmetic unit 202 that performs a control operation. The control calculation unit 202 and the touch panel switch 204 are linked.

  The control calculation unit 202 includes a CPU 206, a TIMER 208 for measurement, a COUNTER 210, various control commands, a RAM 212 that temporarily stores calculation values, an operation program for the CPU 206, a ROM 214 that stores setting data, various setting data, the number of times of integration, and an integration time. An EEPROM 216 or the like is provided as nonvolatile storage means for storing the number of occurrences of abnormality such as failure, history, and the like. Also provided are a plurality of input ports 218, 220, 226, 228 for receiving various sensor inputs and a plurality of output ports 230, 232, 234, 236, 238, 240, 242, 270 for sending drive outputs to the actuators. . That is, temperature sensors 58, 66, and 68 are connected to the input port 218 through the detection circuit 244. Proximity sensors 42, 44, 46, 98, 100, 102, 104, 120 are connected to the input port 220 through the detection circuit 246, and a pressure switch 76 is connected to the input port 226 through the detection circuit 252. Further, driving circuits 254, 256, 258, 260, 262, 264 are connected to the output ports 230, 232, 234, 236, 238, 240, respectively, and the vacuum pump 70, the blower 18, the heaters 60, 64, and the air cylinder are connected thereto. 36, 94, 96, open / close valves 22, 30, 32, 116, and vacuum breaker valve 78 are connected. A speaker 268 is connected to the output port 242 via an audio circuit 266 as a notification means.

  A touch panel switch 204 is connected to the input port 228 and the output port 270. The touch panel switch 204 hierarchically displays control command input, setting input, abnormality display, operation information, and the like as images. This is means for receiving an input position designated by an image as a switch. The touch panel switch 204 stores a CPU 272 that performs image hierarchical display, switch input position control, and the like, a RAM 274 that temporarily stores control data, an image memory 276 that includes an EEPROM that stores image data, a control program for the CPU 272, and setting data. ROM 278, input circuit 280, output circuit 282, liquid crystal drive circuit 284, and detection circuit 286. The liquid crystal drive circuit 284 has a display 288 as a display means for performing liquid crystal display, and the detection circuit 286 has a liquid crystal screen. A provided switch 290 is connected.

  In the above configuration, the resin drying method will be described.

  FIG. 5 is a flowchart showing the operation of the resin drying apparatus. When the operation of the control device 200 is started by the operation of the switch 290 of the touch panel switch 204, in step S1, the mode is shifted to the drying mode, the inside of the drying treatment tank 4 is depressurized, and heat drying is performed.

  In step S2, it is determined whether or not the resin pellet 2 replenishment mode is selected by the switch 290. When the resin replenishment mode is selected, the process proceeds to step S3 and the resin replenishment mode is executed. In step S4, it is determined whether or not the resin supply / replenishment mode is selected by the switch 290. When the resin supply / replenishment mode is selected, the process proceeds to step S5 to execute the resin supply / replenishment mode.

  In step S6, it is determined whether or not the resin supply mode is selected by the switch 290. When the resin supply mode is selected, the process proceeds to the resin supply mode in step S7. In step S8, it is determined whether or not the resin pellet 2 remains in the drying treatment tank 4. If there is no resin pellet 2, the operation is stopped.

  That is, the control operation of the resin drying apparatus includes a drying mode, a resin replenishment mode, a resin supply / replenishment mode, and a resin supply mode.

  The drying mode is a mode in which the resin pellets 2 filled in the drying treatment tank 4 are heated under reduced pressure and dried. That is, when the resin pellet 2 is loaded in the drying treatment tank 4, the vacuum pump 70 is driven to keep the drying treatment tank 4 in a reduced pressure state. That is, the opening and closing plate 88 is closed, the opening and closing plates 38 and 90 are closed to make the drying treatment tank 4 hermetically sealed, the vacuum pump 70 is operated to depressurize the drying treatment tank 4, and the resin pellets 2 are heated by the heaters 60 and 64. Is dried by heating. With the operation of the vacuum pump 70, outside air flows into the drying treatment tank 4 from the leak pipe 106, and the inside of the drying treatment tank 4 is maintained in a reduced pressure state of about 50 to 100 torr. The vapor generated from the resin pellet 2 is discharged to the outside as indicated by the arrow f along with the outside air flowing in from the leak pipe 106 by the suction of the vacuum pump 70. The evaporation temperature of water decreases in the drying treatment tank 4 due to the reduced pressure. Thereby, the heating temperature of the heaters 60 and 64 can be kept below a temperature at which the discoloration of the resin pellet 2 does not occur. The inside of the drying treatment tank 4 can be recovered to atmospheric pressure by stopping the vacuum pump 70 and operating the vacuum breaker valve 78.

  Next, the resin replenishment mode is a mode in which undried resin pellets 2 are loaded into the drying treatment tank 4. That is, in this control operation, the open / close plate 38 is opened, the open / close valves 30 and 116 are closed, and the open / close valves 22 and 32 are opened to form an air passage including the supply pipe 14, the suction pipe 20, and the exhaust pipe 28, By the operation of the blower 18, the resin pellet 2 is guided from the pellet tank 6 to the hopper 12 and supplied to the drying treatment tank 4. The blower 18 is operated until the proximity sensor 46 detects the resin pellet 2. When the resin pellet 2 is filled in the drying treatment tank 4, the opening / closing plate 38 is closed and vacuum drying is executed. The blower 18 is intermittently operated by being divided into several times every predetermined time. If the proximity sensor 46 does not detect the resin pellet 2 even if the blower 18 is operated a predetermined number of times within the predetermined time, the pellet 18 It is determined that the inside of the tank 6 is empty, and an alarm sound is emitted from the speaker 268 as the determination output, or the fact is displayed on the display 288.

  Next, the resin supply / replenishment mode is a mode in which the resin pellets 2 subjected to the drying treatment in the drying treatment tank 4 are weighed and supplied to the injection molding machine 10, and the shortage resulting therefrom is replenished from the pellet tank 6 to the drying treatment tank 4. It is. When the proximity sensor 120 detects that the resin pellet 2 in the resin tank 118 has been consumed as the molding operation of the injection molding machine 10 proceeds, the inside of the drying treatment tank 4 is returned to atmospheric pressure, and the opening and closing plates 38 and 90 are opened. The opening / closing plate 88 is opened for a predetermined time, and the resin pellets 2 in the drying treatment tank 4 are freely dropped into the storage tank 8. The amount dropped into the storage tank 8, that is, the supply amount can be adjusted by changing the opening time of the opening and closing plate 88. Then, the on-off valves 22 and 32 are closed, the on-off valves 30 and 116 are opened to form an air circulation path of the air supply pipe 26, the supply pipe 112, and the intake pipe 114, and the blower 18 is operated for a predetermined time to store the tank by the air pressure. Eight resin pellets 2 are supplied to the resin tank 118. When the accumulation of the resin pellet 2 is not detected by the proximity sensor 120, the opening / closing plates 90 and 88 are opened again, and the blower 18 is operated so that the resin pellet 2 is supplied. Thereafter, the opening / closing plate 38 is opened, and the supply state is maintained until the proximity sensor 46 detects the resin pellet 2.

  Next, the resin supply mode is a mode in which the resin pellets 2 are supplied to the injection molding machine 10 until the resin pellets 2 in the drying treatment tank 4 disappear. This supply operation is as described above. Even if the resin pellet 2 is supplied a predetermined number of times within a predetermined time, if the proximity sensor 120 does not detect it, it is determined that the inside of the drying treatment tank 4 is empty, and the supply and drying operations are stopped.

  Next, FIG. 6 shows operation timings such as supply of the resin pellet 2, and A shows a detection signal of the proximity sensor 120. The vacuum pump 70 stops operating with the rise of the detection signal as an operation command. B shows the operation of the vacuum pump 70, and C shows the opening operation of the vacuum break valve 78. The inside of the drying treatment tank 4 is restored to atmospheric pressure. D indicates opening / closing of the opening / closing plate 90, and E indicates opening / closing of the opening / closing plate 88. The opening / closing plate 90 is opened after a time ta from the opening operation of the vacuum breaking valve 78, and the opening / closing valve 88 is opened after a time tb. The opening / closing plate 88 is opened for a metering time tc for supplying a predetermined amount of the resin pellets 2 and allows the predetermined amount of the resin pellets 2 to freely fall into the storage tank 8. Thereafter, the opening / closing plate 88 is closed, and the opening / closing plate 90 is closed after the time td when the resin pellet 2 is completely dropped into the storage tank 8. F indicates the operation of the blower 18. That is, after the opening / closing plate 90 is closed, the vacuum pump 70 starts to operate again, the blower 18 is operated for a time te, and the resin pellet 2 in the storage tank 8 is supplied to the injection molding machine 10 side. The blower 18 operates for a time tf even after the proximity sensor 120 detects the accumulation of the resin pellets 2 to prevent the resin pellets 2 in the supply pipe 112 from remaining.

  That is, in this resin drying apparatus, since the two opening and closing plates 88 and 90 are provided with a space between the drying treatment tank 4 and the storage tank 8, when the opening and closing plate 88 is closed, FIG. As shown, the resin pellet 2 falling between the opening / closing plate 88 and the inner wall surface of the connecting portion 84 is cut into the notch 91 to prevent the resin pellet 2 from falling, and the supply amount of the resin pellet 2 to be dropped is reduced. Weigh. That is, when the opening / closing plate 88 is closed, the drying treatment tank 4 cannot be sealed and kept in an airtight state.

  After the closing operation of the opening / closing plate 88, as shown in FIG. 3, the drying treatment tank 4 can be sealed and kept airtight by closing the opening / closing plate 90, and the space 92 has the opening / closing plate 88 and the bite. The interval between the opening and closing plates 88 and 90 is set so that the resin pellet 2 held in contact with the opening and closing of the opening and closing plate 90 is not in contact. As a result, the opening / closing plate 90 can reliably bring the drying treatment tank 4 into an airtight state without coming into contact with the resin pellet 2.

  Next, the abnormality detection operation will be described. In the control unit shown in FIG. 4, the following abnormality is detected.

  a Abnormal detection of pressure switch 76

  When the pressure switch 76 outputs a pressure reduction signal before the operation of the vacuum pump 70 is started, a message such as “abnormal pressure switch” is displayed or voiced to instruct the replacement of the pressure switch 76.

  b Detection of abnormal decompression

  When the operation of the vacuum pump 70 is started and the pressure switch 76 does not reduce the pressure to a predetermined pressure after a predetermined time has elapsed, the vacuum pump 70 is stopped, the vacuum breaker valve 78 is operated, and the open / close plates 38, 88, 90 are several. After being opened and closed once, the vacuum pump 70 is operated again to start depressurization. When these operations are executed several times and the drying treatment tank 4 is not depressurized by the pressure switch 76, a message such as “vacuum abnormality” is displayed or voiced to notify the airtightness of the vacuum pump 70 or the open / close plates 38, 88, 90. Instructing replacement of packing, O-rings 87, 89, etc. for maintenance.

  c Detection of abnormalities in the open / close plates 38, 88, 90

  When the air cylinders 36, 94, 96 are operated to open / close the open / close plates 38, 88, 90, and no signals are detected from the proximity sensors 42, 44, 98, 100, 102, 104, the corresponding open / close plates 38, 88 , 90 is opened and closed several times to determine whether an open / close detection signal is output. If the open / close detection signal is not obtained, “open / close plate (38) open error”, “open / close plate (38) close error”, “open / close plate (88) open error”, “open / close plate (88) close error” ”,“ Opening / closing plate (90) opening abnormality ”,“ opening / closing plate (90) opening abnormality ”, and the like are displayed or sounded.

  d Abnormality detection of heaters 60 and 64

  If the temperature sensor 58, 66, 68 detects a temperature rise due to the heaters 60, 64 and the temperature rise is not confirmed even after a predetermined time has elapsed, a message such as “heater disconnection abnormality” is displayed or voiced.

  e Overheat abnormality detection

  When the temperature rise due to heating of the heaters 60, 64 exceeds a predetermined temperature by the temperature sensors 58, 66, 68, a message such as “abnormal heater overheating” is displayed or voiced.

  f Temperature sensor 58, 66, 68 abnormality detection

  By receiving the output values of the temperature sensors 58, 66 and 68, the detection circuit 244 monitors abnormalities such as disconnection. When disconnection of the temperature sensor 58, 66 or 68 is detected, a message such as “abnormality of the temperature sensor (58, 66 or 68)” is displayed or notified by voice.

  g Detection of resin supply abnormality

  The opening and closing plates 88 and 90 are opened, the resin pellet 2 is supplied to the storage tank 8, the blower 18 is operated, and the output signal from the proximity sensor 120 is confirmed. When the output signal is not detected, the opening and closing of the opening and closing plates 88 and 90 and the blower 18 are operated several times. If the output signal is not detected, a message such as “resin supply abnormality” is displayed or voiced, and the blower 18 Abnormality or blockage of the air supply pipe 26, the supply pipe 112, the intake pipe 114, etc. is notified.

  Next, FIG. 7 is a flowchart showing the operation time, the total number of operations, and the storage of the operation time of the resin drying apparatus.

  In step S11, power supply is started, and it is determined whether or not the control device 200 has started operation. At the time of power feeding, the process proceeds to step S12, and the cumulative storage process is started for the number of times of one or both of the elapse of time from the start of power supply, power on and off. When the power is shut off, the process proceeds to step S13, and the accumulated storage process of the operation time and the number of operations ends.

  In step S <b> 14, it is determined whether any one of a resin replenishment mode, a resin supply / replenishment mode, and a resin supply mode by operating the switch 290 is selected. At the time of the automatic operation, the process proceeds to step S15, and the automatic storage time and number of times accumulation storage process is started. When it is not during the automatic operation, the process proceeds to step S16, and the automatic storage time and number of times accumulation storage process is terminated.

  In step S17, it is determined whether or not the vacuum pump 70 has started operation. When the operation of the vacuum pump 70 is started, the process proceeds to step S18, and the accumulated storage processing of the operation time and the number of times of the vacuum pump 70 is started. When the vacuum pump 70 is not operating, the process proceeds to step S19, and the accumulated storage process of the operating time and the number of times of the vacuum pump 70 is ended.

  In step S20, it is determined whether or not the blower 18 has started operation. When the blower 18 starts to operate, the process proceeds to step S21, and the cumulative storage process of the operation time and the number of times of the blower 18 is started. When the blower 18 is not operating, the process proceeds to step S22, and the cumulative storage process of the operation time and the number of times of the blower 18 is terminated.

  In step S23, it is determined whether or not the opening / closing plate 38 has started operation. When the opening / closing plate 38 starts an opening / closing operation, the process proceeds to step S24, where the number of operations or the operation time of the opening / closing plate 38 is accumulated. When the operation of the opening / closing plate 38 is stopped, the process proceeds to step S25, and the accumulated storage process of the number of operations or operation time of the opening / closing plate 38 is ended.

  In step S26, it is determined whether or not the opening and closing plates 88 and 90 have started operation. When the opening and closing plates 88 and 90 start to operate, the process proceeds to step S27, and the accumulated storage processing of the number of operations or the operating time of the opening and closing plates 88 and 90 is started. When the operation of the opening / closing plates 88, 90 is stopped, the process proceeds to step S28, and the accumulated storage process of the number of operations or the operation time of the opening / closing plates 88, 90 is ended.

  Next, FIG. 8 is an operation flowchart for accumulating the operation time or the number of operations and displaying the accumulated time and the number of times of accumulation.

  In step S31, it is determined whether or not the power supply time of the control device 200, the number of times of power supply, the integration time by automatic operation, and the number of integration have reached a predetermined value. When the predetermined value is reached, the process proceeds to step S32, where the integration time and the number of integrations are notified by a warning sound, notification sound, display, and the like. The notification time and the number of times can be arbitrarily changed.

  In step S33, the operation time or the number of operations of the vacuum pump 70 is integrated, and it is determined whether or not the integration time or the number of integrations, which is the integrated value, has reached a predetermined value. When the integrated value reaches the predetermined value, the process proceeds to step S34, and the integrated time and the integrated number are notified by a warning sound, a notification sound, a display, and the like.

  In step S35, the operating time or the number of times of operation of the blower 18 is integrated, and it is determined whether or not the integrated time or the integrated number that is the integrated value has reached a predetermined value. When the integrated value reaches the predetermined value, the process proceeds to step S36, and the integrated time and the integrated number are notified by a warning sound, a notification sound, a display, and the like.

  In step S37, the operating time or the number of times of operation of the open / close plates 38, 88, 90 is integrated, and it is determined whether or not the integrated time or the integrated number that is the integrated value has reached a predetermined value. When the integrated value reaches the predetermined value, the process proceeds to step S38, and the integrated time and the integrated number are notified by a warning sound, a notification sound, a display, and the like.

  In step S39, it is determined by operating the switch 290 whether or not a command for displaying the integrated value of each time and the number of times, that is, the integration time and the number of times of integration, has been issued. If YES, the process proceeds to step S40, and the integration time and the number of integrations are notified by a notification voice, display, and the like.

  Next, FIG. 9 shows a flowchart regarding the number of occurrences of abnormalities such as failures and the notification of history.

  When the operation is started, in step S51, the operation mode or the integrated value storage mode of the number of operations is entered. In this mode, it is determined in step S52 whether or not an abnormality has been detected. When the abnormality detection is confirmed, the process proceeds to step S53, the process proceeds to an abnormality history storage mode such as failure, and the process is performed. If the abnormality detection is not confirmed, the process proceeds to step S54 to determine whether or not there is an abnormality history display command such as a failure. If there is an abnormality history display command, the process proceeds to step S55 to shift to the abnormality history display mode and the process is performed. If there is no abnormality history display command, the process proceeds to step S56 to determine whether or not the operation is stopped. If not, the process returns to step S51. If the operation is stopped, the operation is stopped. The operation ends.

  Through the above process, it is possible to detect and notify abnormality history such as failure, etc., and to predict the occurrence of unexpected situations such as stoppage during molding, so that maintenance inspection such as replacement of parts can be performed, The productivity of resin molding can be increased.

  In the embodiment, the number of integrations and the integration time of representative means and functional parts have been described as examples. However, the means and functional parts to be managed with the integration time and the integration number are specifically described in the examples. Although not done, it includes various parts that are subject to aging and longevity.

As described above, the most preferable embodiment and the like of the present invention have been described. However, the present invention is not limited to the above description, and is described in the claims or disclosed in the specification. It goes without saying that various modifications and changes can be made by those skilled in the art based on the above gist, and such modifications and changes are included in the scope of the present invention.

The present invention relates to a resin drying method used for drying resin pellets before resin molding, and since resin drying is interlocked with resin molding, the productivity of resin supply and resin molding can be improved, which is useful.

It is a figure which shows the resin drying apparatus which is one Embodiment of this invention. It is a partial expanded sectional view of a resin drying apparatus. It is a partial expanded sectional view of a resin drying apparatus. It is a block diagram which shows the control part of this resin drying apparatus. It is a flowchart which shows operation | movement of the resin drying apparatus which concerns on the resin drying method of this invention. It is a timing chart which shows operation | movement of a resin drying apparatus. It is a flowchart which shows integration | storage of the operation time in the resin drying apparatus, and the frequency | count of operation | movement, and a memory | storage process. It is a flowchart which shows the alerting | reporting of the integration time in the resin drying apparatus, and the frequency | count of integration. It is a flowchart which shows memory | storage and alerting | reporting of the abnormality log | history in a resin drying apparatus.

Explanation of symbols

2 Resin pellet (resin)
4 Drying tank 6 Pellet tank (replenishment means)
8 Reservoir (supply means)
10 Injection molding machine 14 Supply pipe (supply means)
18 Blower (replenishment means, supply means)
26 Air supply pipe (supply means)
42, 44, 46, 98, 100, 102, 104, 120 Proximity sensor 60 Heater (heating means)
62 Heat pipe (heating means)
64 Heater (heating means)
58, 66, 68 Temperature sensor 70 Vacuum pump (pressure reduction means)
72 Ventilation pipe 78 Pressure switch 112 Supply pipe (supply means)
200 Control device (control means)
212 RAM (storage means)
214 ROM (storage means)
216 EEPROM (storage means)
266 Audio circuit (notification means)
268 Speaker (notification means)
288 Display (display means)

Claims (7)

A resin drying method of drying a resin in conjunction with an injection molding machine and supplying a dry resin to the injection molding machine according to resin molding of the injection molding machine,
Placing the resin to be dried in a drying bath;
A step of depressurizing the drying treatment tank;
Heating the resin in the drying tank under reduced pressure;
According to the resin consumption of the injection molding machine, the first opening / closing means together with the first opening / closing means at the connecting portion between the storage tank for storing the resin discharged from the drying treatment tank and the drying treatment tank. A step of transferring the resin in the drying treatment tank from the discharge port of the drying treatment tank to the storage tank through the connection part by opening the second opening / closing means in the connection part with a space therebetween ,
After the resin is transferred to the storage tank, the first opening / closing means is closed, the second opening / closing means is closed a predetermined time after the first opening / closing means is closed, and the drying treatment tank is opened. A process of sealing,
Supplying the resin in the storage tank from the storage tank to the injection molding machine;
Supplying the resin to be dried to the drying treatment tank;
A resin drying method comprising: A resin drying method of drying a resin in conjunction with an injection molding machine and supplying a dry resin to the injection molding machine according to resin molding of the injection molding machine,
Placing the resin to be dried in a drying bath;
A step of depressurizing the drying treatment tank;
Heating the resin in the drying tank under reduced pressure;
Supplying the resin dried in the drying treatment tank to the injection molding machine;
Supplying the resin to be dried to the drying treatment tank;
Accumulate operating time or number of operations related to decompression of the drying treatment tank, heating of the resin, replenishment of the resin from the drying treatment tank to the injection molding machine, or supply of the resin to the drying treatment tank Storing the integration time or the number of integrations in the storage means;
A step of notifying when the integration number or the integration time reaches a predetermined value;
A resin drying method comprising: In the resin drying method of Claim 2,
The resin drying method, wherein the integration time or the integration count includes integration of operation times or operation counts of functional components that execute control of drying, decompression, replenishment, or supply of the resin. In the resin drying method of Claim 2,
A resin drying method comprising a step of displaying the number of times of integration or the time of integration. In the resin drying method according to claim 1 or 2 ,
A resin drying method comprising a step of detecting a failure of a specific functional component and storing the failed functional component and an accumulated time or accumulated number of times when the failure occurs in a storage means. In the resin drying method according to claim 1 or 2 ,
A resin drying method comprising a step of storing an abnormality history and displaying the abnormality history. In the resin drying method according to claim 1 or 2 ,
A resin drying method comprising: monitoring the presence or absence of the resin in the drying treatment tank and stopping the drying operation when there is no resin.

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