Metering supply device

Abstract

To provide a measuring and feeding device capable of simultaneously feeding a plurality of kinds of secondary materials to a molding machine.SOLUTION: A measuring and feeding device 1 includes: a first measuring unit 12 that measures and cuts out a masterbatch that is one type of secondary material; and a second measuring unit 14 that measures and cuts out other type of secondary material, such as foamed material. The first measuring unit 12 and the second measuring unit 14 operate in parallel with an operation of an injection molding machine 2. The masterbatch cut out from the first measuring unit 12 and the foamed material cut out from the second measuring unit 14 are supplied to the injection molding machine 2 by a supply transport unit 15.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a metering and feeding device that measures auxiliary materials mixed with a main material and supplies them to a molding machine.

Background Art

[0002] In the production of plastic products, in addition to plastic pellets which are the main material of plastic products, auxiliary materials (additives) such as masterbatch in which pigments are pelletized and foaming agents may be used.

[0003] For example, in injection molding processing, a screw provided in the cylinder of an injection molding machine is rotated, and by the rotation of the screw, plastic pellets are supplied from the main material hopper into the cylinder. On the other hand, in conjunction with the supply of plastic pellets, an auxiliary material for one shot is measured by a metering and feeding device, and the auxiliary material for one shot is supplied to a portion connecting the main material hopper and the cylinder. Thereby, an auxiliary material is added to the plastic pellets supplied into the cylinder. Then, the mixed material obtained by adding the auxiliary material to the plastic pellets is plasticized (heated and melted) and injected from the cylinder into the cavity of the mold.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the metering and feeding device of Patent Document 1, only one type of auxiliary material can be supplied to the injection molding machine at a predetermined timing. Auxiliary materials other than those supplied from the metering and feeding device to the injection molding machine must be premixed with the plastic pellets.

[0006] The objective of the present invention is to provide a metering and dispensing device that can simultaneously supply multiple types of auxiliary materials to a molding machine.

[0007] Another object of the present invention is to provide a metering and dispensing device that can reduce uneven mixing of auxiliary materials in a mixture of main and auxiliary materials. [Means for solving the problem]

[0008] To achieve the above objective, a weighing and supplying device according to one aspect of the present invention is a weighing and supplying device for weighing auxiliary materials to be mixed with a main material and supplying them to a molding machine, and includes a supply unit that weighs and cuts out auxiliary materials, a transport unit that transports the auxiliary materials cut out from the supply unit to the molding machine, and a control unit that controls the operation of the supply unit so that a fixed amount of auxiliary material is cut out from the supply unit in conjunction with the operation of the molding machine.

[0009] In this configuration, multiple supply units are provided to weigh and cut out auxiliary materials, corresponding to the different types of auxiliary materials. Therefore, multiple types of auxiliary materials can be supplied to the molding machine simultaneously in conjunction with the operation of the molding machine. Furthermore, compared to cases where multiple types of auxiliary materials are pre-mixed and transported together, each auxiliary material is transported in conjunction with the operation of the molding machine, making separation of auxiliary materials due to specific gravity or static electricity during transport less likely.

[0010] The control unit may operate multiple supply units in parallel in conjunction with the operation of the molding machine.

[0011] This allows multiple types of auxiliary materials to be mixed with the main material supplied to the molding machine in appropriate mixing ratios.

[0012] The control unit may start and stop the operation of multiple supply units simultaneously, and operate each unit at a speed corresponding to the quantity of auxiliary material it dispenses.

[0013] This allows multiple types of auxiliary materials to be mixed with the main material in appropriate mixing ratios from the time the main material is supplied to the molding machine until it is stopped.

[0014] At least a portion of the supply section has a supply port for supplying auxiliary materials to the transport section, and may be equipped with an opening / closing damper that is displaceable between an open position that opens the supply port and a closed position that closes the supply port.

[0015] In this configuration, the supply port of the supply unit can be opened and closed by an opening / closing damper. While the supply unit is stopped, the opening / closing damper is in the closed position, closing the supply port and preventing the secondary material from leaking out. As a result, it is possible to prevent unwanted secondary materials from mixing with the main material.

[0016] The supply unit equipped with an opening / closing damper may also be a supply unit that weighs and cuts out foam material as a secondary material.

[0017] By equipping the supply unit that weighs and cuts the foam material with an opening / closing damper, it is possible to prevent the foam material from being undesirably mixed into the main material.

[0018] The supply section may be provided according to the masterbatch and the foaming agent, respectively.

[0019] Furthermore, the molding machine may be an injection molding machine, in which case it is preferable that the control unit controls the operation of the supply unit so that a fixed amount of auxiliary material is dispensed separately during the metering operation, when a mixed material of the main material and auxiliary material is supplied to the cylinder of the injection molding machine, and during the injection operation, when the mixed material is injected from the cylinder.

[0020] In an injection molding machine, a screw inserted into the cylinder rotates to supply a mixture of the main material and auxiliary material to the cylinder. After that, the screw moves toward the tip of the cylinder, and the mixture is injected from the injection nozzle at the tip of the cylinder. If the auxiliary material is not supplied to the injection molding machine during the injection operation, only the main material will be supplied onto the screw, and as the screw moves, only the main material will be supplied to the cylinder.

[0021] By cutting out the auxiliary material from the supply unit separately during the metering operation and the injection operation, during the injection operation as well, the main material and the auxiliary material are supplied onto the screw, and a mixed material of the main material and the auxiliary material can be supplied to the cylinder. Therefore, uneven mixing of the auxiliary material in the mixed material can be reduced, and high-quality plastic products can be manufactured.

[0022] The metering and supply device according to another aspect of the present invention is a metering and supply device that measures an auxiliary material mixed with a main material and supplies it to an injection molding machine, including a supply unit that measures and cuts out the auxiliary material, a transport unit that transports the auxiliary material cut out from the supply unit to the injection molding machine, and a control unit that controls the operation of the supply unit so that a fixed amount of the auxiliary material is cut out from the supply unit in conjunction with the operation of the injection molding machine. The control unit controls the operation of the supply unit so that a fixed amount of the auxiliary material is cut out separately during the metering operation of supplying a mixed material of the main material and the auxiliary material to the cylinder of the injection molding machine and during the injection operation of injecting the mixed material of the main material and the auxiliary material from the cylinder.

[0023] According to this configuration, in conjunction with the operation of the injection molding machine, a fixed amount of the auxiliary material can be supplied to the injection molding machine. And by cutting out the auxiliary material from the supply unit separately during the metering operation and the injection operation, during the injection operation as well, the main material and the auxiliary material are supplied onto the screw, and a mixed material of the main material and the auxiliary material can be supplied to the cylinder. Therefore, uneven mixing of the auxiliary material in the mixed material can be reduced, and high-quality plastic products can be manufactured.

[0024] The control unit may determine the amounts of the auxiliary material cut out from the supply unit during the metering operation and the injection operation, respectively, according to the ratio of the time of the metering operation to the time of the injection operation in the injection molding machine.

[0025] Thereby, the mixing ratio of the auxiliary material to the main material during the metering operation and the injection operation can be made consistent.

[0026] In an injection molding machine, when changing the type of auxiliary material used for injection molding, after the completion of the pre-change injection molding using the pre-change auxiliary material and before the start of the post-change injection molding using the post-change auxiliary material, a free shot operation may be performed to discard the mixed material ejected from the cylinder. In this case, it is preferable that the control unit controls the operation of the supply unit so that more of the post-change auxiliary material is cut out from the supply unit during the free shot operation than during the post-change injection molding.

[0027] With such a configuration, the time of the free shot operation can be shortened.

[0028] The control unit may include a memory, and during the operation of the supply unit, measure the cutting ability of the auxiliary material by the supply unit and store the measured cutting ability in the memory.

[0029] When the supply unit includes a screw that cuts out the auxiliary material by rotation, the relationship between the rotation speed of the screw and the amount of the auxiliary material cut out from the supply unit per unit time may be stored in the memory as the cutting ability of the supply unit.

[0030] Further, the control unit may determine the rotation speed of the screw according to the fixed quantity of the auxiliary material cut out from the supply unit and the time when the auxiliary material is cut out from the supply unit based on the cutting ability stored in the memory.

[0031] Thereby, the supply amount of the auxiliary material can be stabilized immediately after the start of the supply of the auxiliary material by the supply unit.

Advantages of the Invention

[0032] According to the present invention, a plurality of types of auxiliary materials can be supplied to the molding machine in conjunction with the operation of the molding machine. In addition, uneven mixing of the auxiliary material in the mixed material of the main material and the auxiliary material can be reduced.

Brief Description of the Drawings

[0033] [Figure 1] It is a diagram schematically showing the configuration of a metering and supply device according to an embodiment of the present invention. [Figure 2] This is a block diagram showing the electrical configuration of a weighing and dispensing device. [Figure 3] This is a diagram showing an example of a graphic screen. [Figure 4] This figure shows an example of the molding conditions screen. [Figure 5] This figure shows an example of a weighing history screen. [Figure 6] This is a flowchart showing the process for determining the operating speed. [Figure 7] This is a timing chart illustrating the supply operation of auxiliary materials to an injection molding machine by a metering and feeding device. [Figure 8] This flowchart shows the flow of memory processing for data extraction. [Figure 9] This is a flowchart showing the process for increasing the number of free shots. [Modes for carrying out the invention]

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0035] <Measuring supply device> Figure 1 is a diagram illustrating the configuration of a weighing and dispensing device 1 according to one embodiment of the present invention.

[0036] The weighing and supplying device 1 is used in plastic product manufacturing equipment to weigh auxiliary materials to be mixed with the main material of the plastic product and supply those auxiliary materials to the injection molding machine (IMM) 2. The weighing and supplying device 1 is configured to supply two types of auxiliary materials to the injection molding machine 2 and includes a first replenishment transport unit 11, a first weighing unit 12, a second replenishment transport unit 13, a second weighing unit 14, a supply transport unit 15, a first discharge transport unit 16, a branching switch unit 17, and a second discharge transport unit 18.

[0037] The metering and dispensing device 1 uses a first auxiliary material tank 21 and a second auxiliary material tank 22. In this embodiment, for example, the first auxiliary material tank 21 stores one type of auxiliary material, a masterbatch (coloring agent for resin), and the second auxiliary material tank 22 stores another type of auxiliary material, a foaming agent. The main material is plastic pellets.

[0038] The first supply transport unit 11 pneumatically transports the masterbatch stored in the first auxiliary material tank 21 to the first metering unit 12. The first supply transport unit 11 comprises a plurality of supply pipes 31 and a supply chute 32 to which the base ends of each supply pipe 31 are connected. The tip of each supply pipe 31 is connected to a separate first auxiliary material tank 21. In this embodiment, eight supply pipes 31 are provided in the first supply transport unit 11, and the supply pipes 31 can be connected to a maximum of eight first auxiliary material tanks 21. The masterbatch stored in the first auxiliary material tank 21 is pneumatically transported through the supply pipes 31 toward the supply chute 32 by an airflow generating mechanism such as an ejector (not shown). The masterbatch and air are separated in the supply chute 32, and the masterbatch is discharged from the outlet at the lower end of the supply chute 32.

[0039] In this embodiment, masterbatches are available in multiple colors and can be selected according to production requirements. While one type of foaming agent may be used, multiple types may be prepared and used selectively.

[0040] The first weighing unit 12 weighs the masterbatch transported by the first supply transport unit 11. The first weighing unit 12 is equipped with a first weighing hopper 33, and the masterbatch discharged from the supply chute 32 is received by the first weighing hopper 33 and stored in the first weighing hopper 33. The first weighing hopper 33 is equipped with a load cell 34 for measuring the weight of the first weighing hopper 33. The first weighing hopper 33 is also equipped with a screw feeder 35 for discharging the masterbatch from the first weighing hopper 33.

[0041] The screw feeder 35 comprises a cylinder 36, a supply screw 37, and a supply motor 38. The cylinder 36 is substantially cylindrical in shape. One end of the cylinder 36 is connected to the side wall of the first metering hopper 33. An opening is formed in the side wall of the first metering hopper 33 in the portion surrounded by the cylinder 36, and the inside of the cylinder 36 communicates with the inside of the first metering hopper 33 through this opening. The other end of the cylinder 36 is open as a supply port 39. The supply screw 37 extends along the centerline of the cylinder 36. One end of the supply screw 37 is inserted into the cylinder 36, and the other end penetrates the side wall of the first metering hopper 33. The supply motor 38 is located outside the first metering hopper 33 and is connected to the other end of the supply screw 37 via a coupling. When the supply motor 38 is driven, the supply screw 37 rotates. The rotation of the supply screw 37 sends the masterbatch in the first metering hopper 33 into the cylinder 36, the masterbatch in the cylinder 36 is sent toward the supply port 39, and the masterbatch is dispensed from the supply port 39.

[0042] The second supply transport unit 13 pneumatically transports the foam material stored in the second auxiliary material tank 22 to the second metering unit 14. The second supply transport unit 13 includes a supply pipe 41 and a supply chute 42 to which the base end of the supply pipe 41 is connected. The tip of each supply pipe 41 is connected to the second auxiliary material tank 22. The foam material stored in the second auxiliary material tank 22 is pneumatically transported through the supply pipe 41 toward the supply chute 42 by an airflow generating mechanism such as an ejector (not shown). The foam material and air are separated in the supply chute 42, and the foam material is discharged from the outlet at the lower end of the supply chute 42.

[0043] The second weighing unit 14 weighs the foam material transported by the second supply transport unit 13. The second weighing unit 14 is equipped with a second weighing hopper 43, and the foam material discharged from the supply chute 42 is received by the second weighing hopper 43 and stored in the second weighing hopper 43. The second weighing hopper 43 is equipped with a load cell 44 for measuring the weight of the second weighing hopper 43. The second weighing hopper 43 is also equipped with a screw feeder 45 for discharging the foam material from the second weighing hopper 43.

[0044] The screw feeder 45 comprises a cylinder 46, a feed screw 47, and a feed motor 48. The cylinder 46 is substantially cylindrical in shape. One end of the cylinder 46 is connected to the side wall of the second metering hopper 43. An opening is formed in the side wall of the second metering hopper 43 in the portion surrounded by the cylinder 46, and the inside of the cylinder 46 communicates with the inside of the second metering hopper 43 through this opening. The other end of the cylinder 46 is open as a feed port 49. The feed screw 47 extends along the centerline of the cylinder 46. One end of the feed screw 47 is inserted into the cylinder 46, and the other end penetrates the side wall of the second metering hopper 43. The feed motor 48 is located outside the second metering hopper 43 and is connected to the other end of the feed screw 47 via a coupling. When the feed motor 48 is driven, the feed screw 47 rotates. The rotation of the supply screw 47 sends the foam material in the second metering hopper 43 into the cylinder 46, and the foam material in the cylinder 46 is sent toward the supply port 49, from which the foam material is dispensed.

[0045] The cylinder 46 is equipped with an opening / closing damper 51 that opens and closes the supply port 49. When the supply screw 47 rotates, the opening / closing damper 51 is pushed by the foam material supplied by the supply screw 47 and is in the open position. When the supply screw 47 stops, the opening / closing damper 51 moves from the open position to the closed position due to its own weight, and the opening / closing damper 51 closes the supply port 49. This prevents the foam material from spilling out of the supply port 49 when the supply screw 47 stops.

[0046] The supply and transport unit 15 pneumatically transports the masterbatch weighed in the first metering unit 12 and the foam material weighed in the second metering unit 14 to the injection molding machine 2. The supply and transport unit 15 is equipped with a supply chute 61. The supply chute 61 has an open top and is located below the supply port 39 of the screw feeder 35 of the first metering unit 12 and the supply port 49 of the screw feeder 45 of the second metering unit 14. The lower part of the supply chute 61 is tapered, and one end of the supply transport pipe 62 is connected to its lower end.

[0047] The injection molding machine 2 is equipped with a cyclone 63 and an attachment 65 that holds a main material hopper 64 in which the main material of the plastic product is stored. The main material hopper 64 and the attachment 65 constitute a molding machine hopper that supplies a mixture of main material and auxiliary material to the injection molding machine 2. The other end of the supply transport pipe 62 is connected to the cyclone 63. The masterbatch cut from the supply port 39 of the screw feeder 35 and the foam material cut from the supply port 49 of the screw feeder 45 are received by the supply chute 61 and air transported from the supply chute 61 through the supply transport pipe 62 to the cyclone 63 by an airflow generating mechanism such as an ejector (not shown). In the cyclone 63, the masterbatch and foam material are separated from the air, and the masterbatch and foam material are supplied from the cyclone 63 to the injection molding machine 2 through the additive input pipe 66 and the attachment 65. Furthermore, the main material stored in the main material hopper 64 is supplied to the injection molding machine 2 through the attachment 65.

[0048] The first discharge transport unit 16 can pneumatically transport the masterbatch discharged from the first metering hopper 33 of the first metering unit 12 back to the first auxiliary material tank 21, and can recover the masterbatch of the previously used color when changing colors (resin changes). The first discharge transport unit 16 is equipped with a discharge chute 71. The lower part of the first metering hopper 33 is tapered, and a discharge port 72 is formed at its lower end. The discharge port 72 is opened and closed by a gate shutter 73. When the gate shutter 73 is opened while masterbatch remains in the first metering hopper 33, the masterbatch is discharged from the discharge port 72 and received by the discharge chute 71. The lower part of the discharge chute 71 is tapered, and one end of a discharge transport pipe 74 is connected to its lower end.

[0049] The branching switching unit 17 switches the destination of the masterbatch being transported by the first discharge transport unit 16 among the multiple first auxiliary material tanks 21. The branching switching unit 17 is equipped with multiple branching nozzles 75 (the same number as the supply pipes 31 of the first supply transport unit 11). Each branching nozzle 75 is connected to a separate first auxiliary material tank 21 via a return transport pipe 76. The branching switching unit 17 is also equipped with an insertion nozzle to which the other end of the discharge transport pipe 74 is connected and which is selectively inserted into the branching nozzle 75, and a switching mechanism to switch the insertion destination of the insertion nozzle. The insertion nozzle is inserted by the switching mechanism into the branching nozzle 75 corresponding to the first auxiliary material tank 21 for the masterbatch remaining in the first metering hopper 33. The masterbatch received in the discharge chute 71 is transported by the action of the ejector, via the discharge transport pipe 74, insertion nozzle, branching nozzle 75 and return transport pipe 76 toward the first auxiliary material tank 21 and returned to the first auxiliary material tank 21.

[0050] The second discharge transport unit 18 uses pneumatic transport to return the foam material discharged from the second metering hopper 43 of the second metering unit 14 back to the second auxiliary material tank 22. The second discharge transport unit 18 is equipped with a discharge chute 81. The lower part of the second metering hopper 43 is tapered, and a discharge port 82 is formed at its lower end. The discharge port 82 is opened and closed by a gate shutter 83. When the gate shutter 83 is opened while foam material remains in the second metering hopper 43, the foam material is discharged from the discharge port 82 and received by the discharge chute 81. The lower part of the discharge chute 81 is tapered, and one end of a discharge transport pipe 84 is connected to its lower end. The other end of the discharge transport pipe 84 is connected to the second auxiliary material tank 22. The foam material received in the discharge chute 81 is pneumatically transported through the discharge transport pipe 84 toward the second auxiliary material tank 22 by the action of the ejector, and returned to the second auxiliary material tank 22.

[0051] <Electrical Configuration> Figure 2 is a block diagram showing the electrical configuration of the measuring and dispensing device 1.

[0052] The weighing and dispensing device 1 includes a control unit 91. The control unit 91 includes a microcontroller, which has a CPU and built-in memory such as flash memory or DRAM (Dynamic Random Access Memory).

[0053] The control unit 91 controls the operation of each part of the first supply transport unit 11, the first supply transport unit 12, the second supply transport unit 13, the supply transport unit 15, the first discharge transport unit 16, and the second discharge transport unit 18, including the ejectors of the first supply transport unit 11, the second supply transport unit 13, the supply transport unit 15, the supply motors 38 and 48 of the first metering unit 12 and the second metering unit 14, and the switching mechanism of the branch switching unit 17.

[0054] Furthermore, the weighing and dispensing device 1 is provided with an operation display unit 92. The operation display unit 92 is, for example, a touch panel and is located on the side of the housing of the weighing and dispensing device 1. The control unit 91 controls the display of the operation display unit 92 so that various information and images of operation keys are displayed on the operation display unit 92. When a user presses (touches) an operation key displayed on the operation display unit 92, the operation is received by the operation display unit 92, and a signal corresponding to the content of the operation is transmitted from the operation display unit 92 to the control unit 91. The operation display unit 92 may be installed in another location and connected to the control unit 91 so as to be able to communicate with it.

[0055] <Graphics screen> Figure 3 shows the graphic screen displayed on the operation display unit 92.

[0056] The operation display unit 92 displays a graphic screen as the home screen, which allows the user to check the operating status of each part of the metering and dispensing device 1.

[0057] On the graphic screen, images (figures) 101, 102, 103, 104, 105, 106, and 107 are displayed at the top, representing the injection molding machine 2, the first auxiliary material tank 21, the second auxiliary material tank 22, the first metering hopper 33, the second metering hopper 43, the cyclone 63, and the attachment 65 (molding machine hopper), respectively.

[0058] Image 102, which simulates the first auxiliary material tank 21, displays the tank number of the first auxiliary material tank 21 that supplies the masterbatch to the first metering hopper 33. The tank name of the first auxiliary material tank 21 may be displayed instead of, or together with, the tank number. In addition, below the tank number in Image 102, the letter "L" is displayed to indicate that the amount of masterbatch in the first auxiliary material tank 21 has reached its lower limit.

[0059] On image 103, which is modeled after the second auxiliary material tank 22, the name of the auxiliary material stored in the second auxiliary material tank 22, "Foam," is displayed, and below the name of the auxiliary material, "L" is displayed to indicate that the amount of foam material in the second auxiliary material tank 22 has reached its lower limit.

[0060] Image 104, which simulates the first weighing hopper 33, displays the weight of the first weighing hopper 33 as measured by the load cell 34. The mass (actual mass) of the masterbatch supplied from the first weighing hopper 33 to the injection molding machine 2 can be determined from the change in the weight of the first weighing hopper 33 as measured by the load cell 34. Also, on the right side of image 104, "H" is displayed to indicate that the weight of the first weighing hopper 33 has reached its upper limit, "HH" indicates that the weight of the first weighing hopper 33 has reached its upper limit (greater than the upper limit), "L" indicates that the weight of the first weighing hopper 33 has reached its lower limit, and "LL" indicates that the weight of the first weighing hopper 33 has reached its lower limit (smaller than the lower limit).

[0061] Image 105, which simulates the second weighing hopper 43, displays the weight of the second weighing hopper 43 as measured by the load cell 44. The mass of foam material supplied from the second weighing hopper 43 to the injection molding machine 2 (measured supply amount) can be determined from the change in the weight of the second weighing hopper 43 as measured by the load cell 44. Also, on the left side of image 105, "H" is displayed to indicate that the weight of the second weighing hopper 43 has reached its upper limit, "HH" indicates that the weight of the second weighing hopper 43 has reached its upper limit (greater than the upper limit), "L" indicates that the weight of the second weighing hopper 43 has reached its lower limit, and "LL" indicates that the weight of the second weighing hopper 43 has reached its lower limit (smaller than the lower limit).

[0062] In the injection molding machine 2, a screw inserted into cylinder 3 is rotated to supply a mixture of main and auxiliary materials to cylinder 3, and a metering operation (plasticizing metering operation) is performed in which the mixture is heated, melted, and plasticized. After that, the screw is moved toward the tip of cylinder 3, and an injection operation is performed in which the mixture of main and auxiliary materials is injected from the injection nozzle at the tip of cylinder 3. The mixture injected from the injection nozzle fills the cavity of the mold and is cooled for solidification. When the mixture in the cavity has solidified, the mold is opened, the molded product (plastic product) is demolded and removed from the cavity. During the injection operation, the injection signal input from the control unit of injection molding machine 2 to the control unit 91 of metering and supplying device 1 is turned on. During the metering operation, the metering signal input from the control unit of injection molding machine 2 to the control unit 91 of metering and supplying device 1 is turned on.

[0063] As will be described later, the metering and supplying device 1 supplies the masterbatch and foam material to the injection molding machine 2 (cutting out the masterbatch by the screw feeder 35 of the first metering unit 12 and cutting out the foam material by the screw feeder 45 of the second metering unit 14) separately during the metering operation and the injection operation of the injection molding machine 2.

[0064] At the bottom of the graphic screen, the molding conditions for the molded product are displayed aligned to the right, and to the left of the molding conditions, supply information regarding the supply of the masterbatch and foam material from the metering and supply device 1 to the injection molding machine 2 is displayed.

[0065] The molding conditions include the weight of the molded product, the color amount (in 0.1% units) which is the amount of masterbatch required for 100% of the molded product weight, the foam amount (in 0.1% units) which is the amount of foam required for 100% of the molded product weight, the metering time which is the time for supplying the masterbatch and foam from the metering and supplying device 1 to the injection molding machine 2 during the metering operation of the injection molding machine 2, and the injection time which is the time for supplying the masterbatch and foam from the metering and supplying device 1 to the injection molding machine 2 during the injection operation of the injection molding machine 2. The molding conditions are assigned a condition number and a condition name, and the molding conditions are stored in the memory of the control unit 91 in association with their condition number and condition name.

[0066] The supply information includes the measured amount of masterbatch supplied from the weighing and supplying device 1 to the injection molding machine 2, the measured amount of foaming material supplied from the weighing and supplying device 1 to the injection molding machine 2, the set supply amount of masterbatch calculated from the weight and color of the molded product, the set supply amount of foaming material calculated from the weight and foaming amount of the molded product, the weighing time (measured weighing time), which is the measured time from when the weighing signal input from the injection molding machine 2 to the weighing and supplying device 1 is turned on until it is turned off, and the injection time (measured injection time), which is the measured time from when the injection signal input from the injection molding machine 2 to the weighing and supplying device 1 is turned on until it is turned off.

[0067] Furthermore, at the bottom of the graphic screen, the graphic button 111, color selection button 112, molding condition button 113, individual operation button 114, weighing history button 115, error history button 116, and parameter list button 117 are displayed in this order, arranged horizontally from left to right. In addition to the graphic screen, the operation display unit 92 displays the color selection screen, molding condition screen, individual operation screen, weighing history screen, error history screen, and parameter list screen. Buttons 111 to 117 are also displayed on all screens other than the graphic screen.

[0068] If the graphics button 111 is pressed on any screen other than the graphics screen, the screen will switch to the graphics screen.

[0069] <Color selection screen> When the color selection button 112 is pressed on a screen other than the color selection screen, the screen switches to the color selection screen. On the color selection screen, the user can select the first auxiliary material tank 21, which stores the masterbatch to be transported to the first weighing unit 12 by the first supply transport unit 11.

[0070] <Molding conditions screen> When the molding conditions button 113 is pressed on a screen other than the molding conditions screen, the screen switches to the molding conditions screen. On the molding conditions screen, as shown in Figure 4, the condition number display area 121 and the condition name display area 122 are provided side by side, and below them, the molded product weight display area 123, the color amount display area 124, the foaming amount display area 125, the weighing time display area 126, and the injection time display area 127 are provided side by side. Below the injection time display area 127, the write button 128 and the read button 129 are displayed side by side. Also, at the right edge of the molding conditions screen, a two-digit up button 131 with two upward-pointing triangles arranged vertically, a single-digit up button 132 with an upward-pointing triangle, a single-digit down button 133 with a downward-pointing triangle, and a two-digit down button 134 with two downward-pointing triangles arranged vertically are displayed in this order, arranged vertically.

[0071] The condition number is displayed in the condition number display area 121. When the two-digit up button 131 is pressed, the condition number displayed in the condition number display area 121 changes by "+10". When the single-digit up button 132 is pressed, the condition number displayed in the condition number display area 121 changes by "+1". When the single-digit down button 133 is pressed, the condition number displayed in the condition number display area 121 changes by "-1". When the two-digit down button 134 is pressed, the condition number displayed in the condition number display area 121 changes by "-10".

[0072] If a condition name and molding conditions are already associated with a condition number displayed in the condition number display area 121, pressing the read button 129 will display the condition name in the condition name display area 122, and the molded product weight, color amount, foam amount, weighing time, and injection time will be displayed in the molded product weight display area 123, color amount display area 124, foam amount display area 125, weighing time display area 126, and injection time display area 127, respectively. The molding machine's control unit and the control unit 91 may be configured to communicate, allowing the molding conditions to be selected via input from the molding machine. Furthermore, molding conditions can be input not only through the molding machine's control unit but also through communication with other external devices.

[0073] If the condition name and molding conditions have not yet been associated with the condition number displayed in the condition number display area 121, tapping the condition name display area 122, molded product weight display area 123, color amount display area 124, foam amount display area 125, weighing time display area 126, and injection time display area 127 will cause a key window with alphanumeric input keys to pop up. By operating the various keys in the key window, the condition name, molded product weight, color amount, foam amount, weighing time, and injection time can be entered into the condition name display area 122, molded product weight display area 123, color amount display area 124, foam amount display area 125, weighing time display area 126, and injection time display area 127, respectively. After entering each item of the condition name and molding conditions, pressing the write button 128 will store the condition name and molding conditions in the memory of the control unit 91, associated with the condition number.

[0074] <Each operation screen> When the individual operation button 114 is pressed on a screen other than the individual operation screen, the screen switches to the individual operation screen. On the individual operation screen, it is possible to instruct the execution of a test run in which one or both of the masterbatch and foam material are supplied to the injection molding machine 2 in a single shot. The individual operation screen also allows the execution of the discharge of the masterbatch from the first metering hopper 33 by the first discharge transport unit 16. Furthermore, on the individual operation screen, it is possible to input a condition number and instruct a color change by changing the tank number of the first auxiliary material tank 21 without changing the molding conditions corresponding to that condition number.

[0075] <Weighing History Screen> When the weighing history button 115 is pressed on a screen other than the weighing history screen, the screen switches to the weighing history screen. On the weighing history screen, as shown in Figure 5, the color button 141 and the foaming button 142 are displayed side by side in the upper right corner. The measured supply amounts of masterbatch and foam material supplied from the weighing and supplying device 1 to the injection molding machine 2 are stored in the memory of the control unit 91 each time a measurement is taken (for each shot). When the color button 141 is pressed, the history of the measured supply amounts of masterbatch previously supplied from the weighing and supplying device 1 to the injection molding machine 2 is displayed between the color button 141, the foaming button 142, and buttons 111 to 117. Similarly, when the foaming button 142 is pressed, the history of the measured supply amounts of foam material previously supplied from the weighing and supplying device 1 to the injection molding machine 2 is displayed between the color button 141, the foaming button 142, and buttons 111 to 117. This history can be used for traceability in the manufacturing of molded products.

[0076] <Error History Screen> When the error history button 116 is pressed on a screen other than the error history screen, the screen switches to the error history screen. When an error occurs in the weighing and dispensing device 1, the details of the error and the date and time of occurrence are stored in the memory of the control unit 91. The error history screen displays the history of the error details and the date and time of occurrence stored in the memory.

[0077] <Parameter List Screen> When the parameter list button 117 is pressed on a screen other than the parameter list screen, the screen switches to the parameter list screen. On the parameter list screen, the settings of the internal parameters of the control unit 91, which will be described later, can be displayed and changed. The internal parameters include the free shot multiplier used in the free shot increase process, which will be described later.

[0078] <Processing to determine operating speed> Figure 6 is a flowchart showing the flow of the process for determining the operating speed.

[0079] In the weighing and supplying device 1, the control unit 91 performs the operation speed determination process.

[0080] When molding conditions are entered on the molding conditions screen and the write button 128 is pressed, the input of molding conditions is completed. In the operation speed determination process, in accordance with the completion of the input of molding conditions (YES in step S11), the ratio of metering time and injection time included in the entered molding conditions is calculated. Then, the amount of color included in the molding conditions is divided into amounts according to the ratio of metering time and injection time. The amount according to metering time is determined as the amount of masterbatch (MB) supplied (transported) from the metering supply device 1 to the injection molding machine 2 during the metering operation of the injection molding machine 2. The amount according to injection time is determined as the amount of masterbatch supplied from the metering supply device 1 to the injection molding machine 2 during the injection operation of the injection molding machine 2 (step S12). In addition, the amount of foam included in the molding conditions is divided into amounts according to the ratio of metering time and injection time. Then, the amount corresponding to the metering time is determined as the amount of foam material supplied (transported) from the metering and supplying device 1 to the injection molding machine 2 during the metering operation of the injection molding machine 2. The amount corresponding to the injection time is determined as the amount of foam material supplied from the metering and supplying device 1 to the injection molding machine 2 during the injection operation of the injection molding machine 2 (step S12).

[0081] Subsequently, based on the metering time and the amount of masterbatch supplied during metering included in the molding conditions, the operating speed of the screw feeder 35 of the first metering unit 12, i.e., the rotational speed of the supply motor 38 of the screw feeder 35, is determined so that, for example, the masterbatch is always supplied from the metering and supplying device 1 to the injection molding machine 2 during the metering operation (step S13). Also, based on the metering time and the amount of foaming material supplied during metering included in the molding conditions, the operating speed of the screw feeder 45 of the second metering unit 14, i.e., the rotational speed of the supply motor 48 of the screw feeder 45, is determined so that, for example, the foaming material is always supplied from the metering and supplying device 1 to the injection molding machine 2 during the metering operation (step S13).

[0082] Furthermore, based on the injection time and the amount of masterbatch supplied during injection included in the molding conditions, the operating speed of the screw feeder 35 of the first metering unit 12, that is, the rotational speed of the supply motor 38 of the screw feeder 35, is determined so that, for example, the masterbatch is always supplied from the metering and supplying device 1 to the injection molding machine 2 during the injection operation (step S14). Also, based on the injection time and the amount of foam material supplied during injection included in the molding conditions, the operating speed of the screw feeder 45 of the second metering unit 14, that is, the rotational speed of the supply motor 48 of the screw feeder 45, is determined so that, for example, the foam material is always supplied from the metering and supplying device 1 to the injection molding machine 2 during the injection operation (step S14).

[0083] <Supply operation> Figure 7 is a timing chart illustrating the supply operation of auxiliary materials to the injection molding machine 2 by the metering and supply device 1.

[0084] One shot cycle for molding a molded product using the injection molding machine 2 includes a mold closing time (T1-T2) for closing the mold, a filling time (T2-T3) for filling the mold cavity with plasticized material (a mixture of main and auxiliary materials), a holding time (T3-T4) for maintaining pressure to push the material into the cavity to prevent short shots and sink marks, a cooling time (T4-T6) for cooling and solidifying the material in the cavity, a metering time (T4-T5) for metering the material to be injected in the next shot, a mold opening time (T6-T7) for opening the mold, and a removal time (T7-T8) for removing the molded product from the cavity. The injection time (injection operation time), from when the injection signal input from the injection molding machine 2 to the metering and supply device 1 is turned on until it is turned off, is the sum of the filling time and the holding time (T2-T4).

[0085] When the injection signal input from the injection molding machine 2 to the metering and supplying device 1 is turned ON, the control unit 91 controls the first metering unit 12, the second metering unit 14, and the supply and transport unit 15 to start supplying the masterbatch and foam material from the metering and supplying device 1 to the injection molding machine 2 (time T2). At this time, the screw feeder 35 of the first metering unit 12 and the screw feeder 45 of the second metering unit 14 are controlled to operate at the operating speed determined in the operating speed determination process. Subsequently, when the injection signal input from the injection molding machine 2 to the metering and supplying device 1 is turned OFF, the control unit 91 controls the first metering unit 12, the second metering unit 14, and the supply and transport unit 15 to stop supplying the masterbatch and foam material from the metering and supplying device 1 to the injection molding machine 2 (time T4).

[0086] Furthermore, when the metering signal input from the injection molding machine 2 to the metering and supplying device 1 is turned on, the control unit 91 controls the first metering unit 12, the second metering unit 14, and the supply and transport unit 15 to start supplying the masterbatch and foam material from the metering and supplying device 1 to the injection molding machine 2 (time T4). At this time, the screw feeder 35 of the first metering unit 12 and the screw feeder 45 of the second metering unit 14 are controlled to operate at the operating speed determined in the operating speed determination process. Subsequently, when the metering signal input from the injection molding machine 2 to the metering and supplying device 1 is turned off, the control unit 91 controls the first metering unit 12, the second metering unit 14, and the supply and transport unit 15 to stop supplying the masterbatch and foam material from the metering and supplying device 1 to the injection molding machine 2 (time T5).

[0087] <Memory processing of extraction ability> Figure 8 is a flowchart showing the flow of the extraction capability memory processing.

[0088] In the weighing and dispensing device 1, the control unit 91 performs dispensing capacity storage processing.

[0089] In the cutting capacity memory processing, when the operation of the screw feeder 35 (screw feeder for MB) of the first metering unit 12 is completed (YES in step 21), the measured amount of masterbatch supplied from the metering and supplying device 1 to the injection molding machine 2 and the rotational speed of the supply screw 37 of the screw feeder 35, that is, the rotational speed of the supply motor 38 are acquired. Then, the amount of masterbatch cut per unit time by the screw feeder 35 is calculated (step S22).

[0090] Subsequently, the relationship between the rotational speed of the supply screw 37 and the amount dispensed per unit time is determined, and this relationship is stored in the memory of the control unit 91 as the dispensing capacity of the screw feeder 35 (step S23). This relationship is written to the memory for each type of master batch.

[0091] The cutting capacity stored in the memory of the control unit 91 is used, for example, in the operating speed determination process to correct the operating speed determined from the metering time and the amount of masterbatch supplied during metering, and the operating speed determined from the injection time and the amount of masterbatch supplied during injection, respectively, when the operating speed of the screw feeder 35 is determined. This makes it possible to stabilize the amount of masterbatch supplied from immediately after the first metering unit 12 starts supplying the masterbatch, even when the masterbatch is changed, i.e., when the color is changed.

[0092] <Free shot boosting process> Figure 9 is a flowchart showing the flow of the free shot increase process.

[0093] In the weighing and supplying device 1, the control unit 91 performs a free shot increase process.

[0094] In the free shot increase process, for example, when a color change is instructed on the individual operation screen displayed on the operation display unit 92 (YES in step S31), the free shot operation of the injection molding machine 2 is started (step S32). During the free shot operation, the masterbatch and foam material to be used for molding after the color change are supplied from the metering and supplying device 1 to the injection molding machine 2, and the injection molding machine 2 repeatedly injects material from the cylinder 3 (free shot, discard shot) and supplies material to the cylinder 3 in a transient state where the auxiliary materials before and after the change are mixed.

[0095] During free-shot operation, the metering and supplying device 1 supplies a predetermined amount of masterbatch to the injection molding machine 2 that is greater than the amount of masterbatch supplied during molding after a color change (step S33). Specifically, the metering and supplying device 1 supplies an amount of masterbatch to the injection molding machine 2 equal to the amount of masterbatch supplied per unit time during molding after a color change multiplied by the free-shot ratio. For example, if the free-shot ratio is set to 150%, then 150% (50% increase) of masterbatch per unit time is supplied to the injection molding machine 2 from the metering and supplying device 1 compared to molding after a color change. Note that the free-shot ratio is not limited to 150% and may be any other value greater than 100%. By temporarily increasing the concentration of the masterbatch after a color change, the number of shots required to stabilize the color of the product after the color change can be reduced.

[0096] <Effects> As described above, the weighing and supplying device 1 is equipped with a first weighing unit 12 that weighs and cuts out a masterbatch, which is one type of auxiliary material, and a second weighing unit 14 that weighs and cuts out a foam material, which is another type of auxiliary material. Therefore, two types of auxiliary materials can be supplied to the injection molding machine 2 simultaneously in conjunction with the operation of the injection molding machine 2.

[0097] The first metering unit 12 and the second metering unit 14 operate in parallel with the operation of the injection molding machine 2. This allows the two types of auxiliary materials to be mixed with the main material supplied to the injection molding machine 2 in an appropriate mixing ratio.

[0098] Furthermore, the screw feeder 35 of the first metering unit 12 and the screw feeder 45 of the second metering unit 14 start and stop operating simultaneously, and each operates at a speed corresponding to the amount of auxiliary material it dispenses. This allows the two types of auxiliary materials to be mixed with the main material in an appropriate mixing ratio from the time the main material is supplied to the injection molding machine 2 until it is stopped.

[0099] The screw feeder 45 of the second metering unit 14 is equipped with an opening / closing damper 51 that opens and closes the supply port 49. When no auxiliary material is dispensed from the screw feeder 45, the supply port 49 is closed by the opening / closing damper 51, thereby preventing the auxiliary material from leaking out of the supply port 49. As a result, it is possible to prevent unwanted auxiliary material from being mixed into the main material.

[0100] Furthermore, the auxiliary materials are cut out separately during the metering operation and the injection operation of the injection molding machine 2.

[0101] The screw inserted into the cylinder 3 of the injection molding machine 2 is rotated to supply a mixture of the main material and auxiliary material to the cylinder 3. After that, the screw moves toward the tip of the cylinder 3, and the mixture is injected from the injection nozzle at the tip of the cylinder 3. If the auxiliary material is not supplied to the injection molding machine 2 during the injection operation, only the main material will be supplied onto the screw, and as the screw moves, only the main material will be supplied to the cylinder.

[0102] Because the auxiliary material is dispensed separately during the metering and injection operations, the main material and auxiliary material are supplied to the screw even during the injection operation, allowing a mixed material of the main material and auxiliary material to be supplied to the cylinder 3. Therefore, uneven mixing and color fading of the auxiliary material in the mixed material during a single shot can be reduced, enabling the manufacture of high-quality plastic products. This is particularly suitable for large, integrally molded parts such as automobile body parts.

[0103] The amount of auxiliary material dispensed from the first metering unit 12 and the second metering unit 14 during the metering operation and the injection operation, respectively, is determined according to the ratio of the metering operation time to the injection operation time in the injection molding machine 2. This makes it possible to match the mixing ratio of the auxiliary material to the main material during the metering operation and the injection operation.

[0104] In injection molding machine 2, when changing the type of masterbatch used for injection molding, also known as a color change, a free-shot operation is performed to discard the mixed material injected from cylinder 3. During the free-shot operation, a predetermined amount of masterbatch is supplied from metering and supply device 1 to injection molding machine 2, which is greater than the amount of masterbatch supplied for molding after the color change. As a result, the number of free shots can be reduced, and the free-shot operation time can be shortened.

[0105] <Variation> Although embodiments of the present invention have been described above, the present invention can also be implemented in other forms.

[0106] For example, in the embodiment described above, masterbatch and foaming agent were used as examples of two types of auxiliary materials, but other types of auxiliary materials such as reinforcing agents, modifiers, functional additives, and stabilizers may be used in the metering and feeding device 1. Furthermore, the auxiliary materials are not limited to two types, and the number of supply units (two or more as needed) may be provided to increase the number of types of auxiliary materials that can be supplied simultaneously.

[0107] Furthermore, while the first supply transport unit 11 is configured to transport auxiliary materials from multiple first auxiliary material tanks 21 to the first metering unit 12, the second supply transport unit 13 may also be configured to transport auxiliary materials from multiple second auxiliary material tanks 22 to the second metering unit 14, similar to the first supply transport unit 11. In this case, the second discharge transport unit 18 has the same configuration as the first discharge transport unit 16, and the second discharge transport unit 18 is provided with the same configuration as the branch switching unit 17.

[0108] In the dispensing capacity storage process, the amount of masterbatch dispensed per unit time by the screw feeder 35 of the first metering unit 12 is calculated after the operation of the screw feeder 35 is completed. However, the amount of masterbatch dispensed per unit time by the screw feeder 35 may be calculated while the screw feeder 35 is operating. Also, similar to the screw feeder 35 of the first metering unit 12, the dispensing capacity of the screw feeder 45 of the second metering unit 14 may be determined and stored in the memory of the control unit 91.

[0109] Furthermore, various design modifications can be made to the aforementioned configuration within the scope of the matters described in the patent claims. [Explanation of symbols]

[0110] 1:Measuring and feeding device 2: Injection molding machine (molding machine) 3: Cylinder 12: 1st measuring section (supply section) 14:Second measuring section (supply section) 15: Supply and transportation department (transportation department) 49: Supply port 51: Opening / closing damper 91: Control Unit

Claims

1. A weighing and supplying device that weighs auxiliary materials to be mixed with the main material and supplies them to a molding machine, Multiple supply units are provided according to the different types of auxiliary materials, which weigh and cut out the auxiliary materials. A transport unit that transports the auxiliary material cut from the supply unit to the molding machine, The system includes a control unit that controls the operation of the supply unit so that a fixed amount of auxiliary material is dispensed from the supply unit in conjunction with the operation of the molding machine, The molding machine is an injection molding machine, The aforementioned transport section is A supply chute for receiving auxiliary materials cut from the aforementioned supply unit, The system includes a supply transport pipe through which auxiliary materials transported from the supply chute to the molding machine flow, The control unit controls the operation of the supply unit so that the specified amount of auxiliary material is dispensed separately during the metering operation, when a mixture of the main material and auxiliary material is supplied to the cylinder of the injection molding machine, and during the injection operation, when the mixture is injected from the cylinder.

2. A weighing and supplying device for weighing a secondary material to be mixed with a main material and supplying it to a molding machine, Multiple supply units are provided according to the different types of auxiliary materials, which weigh and cut out the auxiliary materials. A transport unit that transports the auxiliary material cut from the supply unit to the molding machine, The system includes a control unit that controls the operation of the supply unit so that a fixed amount of auxiliary material is dispensed from the supply unit in conjunction with the operation of the molding machine, The molding machine is an injection molding machine, The control unit controls the operation of the supply unit so that the specified amount of auxiliary material is dispensed separately during the metering operation, when a mixture of the main material and auxiliary material is supplied to the cylinder of the injection molding machine, and during the injection operation, when the mixture is injected from the cylinder.

3. A metering and supplying device for measuring and supplying auxiliary materials to be mixed with a main material to an injection molding machine, A supply unit that weighs and cuts out auxiliary materials, A transport unit that transports the auxiliary material cut from the supply unit to the injection molding machine, The system includes a control unit that controls the operation of the supply unit so that a fixed amount of auxiliary material is dispensed from the supply unit in conjunction with the operation of the injection molding machine, The control unit controls the operation of the supply unit so that the specified amount of auxiliary material is dispensed separately during the metering operation, when a mixture of the main material and auxiliary material is supplied to the cylinder of the injection molding machine, and during the injection operation, when the mixture is injected from the cylinder.

4. The metering and dispensing device according to any one of claims 1 to 3, wherein the control unit operates a plurality of the supply units in parallel in conjunction with the operation of the molding machine.

5. The weighing and dispensing apparatus according to claim 4, wherein the control unit simultaneously starts and stops the operation of a plurality of the supply units, and operates each at a speed corresponding to the amount of auxiliary material it dispenses.

6. The weighing and dispensing device according to any one of claims 1 to 5, wherein at least a portion of the supply unit has a supply port for supplying auxiliary materials to the transport unit, and is provided with an opening / closing damper that is displaceable between an open position for opening the supply port and a closed position for closing the supply port.

7. The supply unit, which includes the opening and closing damper, weighs and cuts out foam material as a secondary material, as described in claim 6.

8. The metering and dispensing device according to any one of claims 1 to 7, wherein the supply unit is provided according to the masterbatch and the foaming material, respectively.

9. The metering and supplying device according to any one of claims 1 to 8, wherein the control unit determines the amount of auxiliary material to be dispensed from the supply unit during the metering operation and the injection operation, respectively, according to the ratio of the time of the metering operation and the time of the injection operation in the injection molding machine.

10. In the injection molding machine, when changing the type of auxiliary material used for injection molding, a free shot operation is performed to discard the mixed material injected from the cylinder after the completion of injection molding using the original auxiliary material and before the start of injection molding using the new auxiliary material. The metering and feeding device according to any one of claims 1 to 9, wherein the control unit controls the operation of the supply unit so that, during free shot operation, more of the modified auxiliary material is dispensed from the supply unit than during modified injection molding.

11. The weighing and dispensing device according to any one of claims 1 to 10, wherein the control unit is equipped with a memory, and when the supply unit is in operation, it measures the dispensing capacity of the auxiliary material by the supply unit and stores the measured dispensing capacity in the memory.

12. The aforementioned supply unit is equipped with a screw that cuts out auxiliary materials by rotation, The metering and dispensing device according to claim 11, wherein the memory stores, as the dispensing capacity of the supply unit, the relationship between the rotational speed of the screw and the amount of auxiliary material dispensed from the supply unit per unit time.

13. The weighing and dispensing device according to claim 12, wherein the control unit determines the amount of auxiliary material to be dispensed from the supply unit and the rotation speed of the screw in accordance with the time it takes to dispense the auxiliary material from the supply unit, based on the dispensing capacity stored in the memory.

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