Powder filling device

Abstract

To provide a particulate filling device that can reduce cycle time.SOLUTION: It includes a funnel-shaped hopper 10 for storing particulates, a screw 15 that rotates inside a cylindrical portion at the bottom of the hopper 10 to discharge particulates downward, a cylindrical body 21 having upper and lower openings, a storage part 2 having a gate 22 for opening and closing the opening at the lower end of the cylinder 21, and capable of temporarily storing particulates discharged from the hopper 10 in the cylinder 21, a bag holding part 4 for holding bags filled with particulates discharged from the hopper 10 and supplied via the storage part 2, a weighing part 5 that supports the bag holding part 4 and weighs the total weight of the bag and particulates, and a control device 7 which continuously rotates the screw 15 in order to fill the bag with the target weight of particulates, stores particulates in the storage part 2 with the gate 22 in a closed state until the first predetermined time elapses after starting to rotate the screw 15 and opens the gate 22 when the first predetermined time elapses.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a powder or granular material filling device for filling containers such as bags and bottles with powder or granular material. [Background technology]

[0002] 2. Description of the Related Art Powder and granular material filling devices capable of filling a predetermined amount of powder and granular material into a container such as a bag are known.

[0003] Patent document 1 describes a quantitative bagging device that, when filling a bag with powder or granular material, first makes a large charge at a fast filling speed, then makes a small charge at a slower filling speed, and then reduces the filling speed continuously during this small charge.

[0004] Patent document 2 also describes an auger filling machine that includes a funnel that contains powder and an auger screw that rotates within the cylindrical portion of the funnel, and that drops the powder and supplies it to a bottle by rotating the auger screw. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-292084 [Patent Document 2] Japanese Unexamined Patent Publication No. 1-99641 Summary of the Invention [Problem to be solved by the invention]

[0006] In conventional powder and granular material filling devices, once a container such as a bag or bottle is filled with powder and granular material, the device must be replaced with the next container and then begin filling that container. In this case, it takes time to remove the filled container and prepare the next container, which results in a long cycle time.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a powdered or granular material filling device that can shorten the cycle time.

[0008] In this specification and claims, the "container" into which the powder or granular material is filled includes a bag, a bottle, and the like. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, a powdered or granular material filling device according to one embodiment of the present invention is a powdered or granular material filling device that repeatedly fills a container with a target weight of powdered or granular material, and is equipped with: a funnel-shaped hopper for storing the powdered or granular material; a screw that rotates inside a cylindrical portion at the bottom of the hopper to discharge the powdered or granular material downward; a cylindrical body with openings at the top and bottom; and a gate that opens and closes the opening at the bottom end of the cylindrical body; a storage section that can temporarily store the powdered or granular material discharged from the hopper inside the cylindrical body; a container holding section that temporarily holds the container that is filled with the powdered or granular material discharged from the hopper and supplied through the storage section; a weighing section that supports the container holding section and measures the total weight of the container and the powdered or granular material filled therein; and a control section that continuously rotates the screw to fill the container with the target weight of powdered or granular material, keeps the gate closed and stores the powdered or granular material in the storage section until a first predetermined time has elapsed since the screw began rotating, and opens the gate when the first predetermined time has elapsed.

[0010] With this configuration, the gate of the storage section is closed until the first predetermined time has elapsed since the screw started to rotate, so the powder or granular material discharged from the hopper is temporarily stored in the storage section. During this time, it is possible to remove the container previously filled with powder or granular material (a filled container) from the container holding section, or to prepare the empty container to be filled this time by storing it in the container holding section, thereby shortening the cycle time.

[0011] The control unit may be configured to rotate the screw at a first rotational speed for a second predetermined time longer than the first predetermined time, and then gradually slow down the rotational speed to rotate it at the second rotational speed, and when the weight of the powder or granular material calculated from the total weight measured by the measuring unit becomes the target weight or a predetermined weight smaller than the target weight, stop the rotation of the screw and close the gate.

[0012] According to this configuration, the screw is rotated at a fast first rotation speed for a second predetermined time, and then the rotation speed is gradually slowed down to rotate at the second rotation speed. When the weight of the powder or granular material reaches the target weight or a predetermined weight smaller than the target weight, the rotation of the screw is stopped and the gate is closed, thereby shortening the cycle time and improving the weighing accuracy.

[0013] The device may further include a first lifting device that raises and lowers the storage section between a first lowered position and a first uppered position, and a second lifting device that raises and lowers the container holding section between a second lowered position and a second uppered position, and the control unit may be configured to control the first lifting device to lower the storage section from the first uppered position to the first lowered position when the screw starts to rotate at the first rotational speed, and to raise the storage section from the first lowered position to the first uppered position after the first predetermined time has elapsed, and to control the second lifting device to raise the container holding section holding the container from the second lowered position to the second uppered position before the first predetermined time has elapsed, and to lower the container holding section from the second uppered position to the second lowered position while the rotational speed of the screw is gradually slowing from the first rotational speed to the second rotational speed.

[0014] According to this configuration, by starting to rotate the screw at the first rotational speed when the storage unit is in the first raised position, the falling distance of the powder or granular material discharged into the storage unit is shortened, thereby reducing dust generation and the mixing of air from the atmosphere into the powder or granular material. Subsequently, by lowering the storage unit from the first raised position to the first lowered position, a large amount of powder or granular material can be stored in the storage unit. Furthermore, by raising the container holding unit holding the container from the second lowered position to the second raised position before the first predetermined time has elapsed, i.e., before the gate of the storage unit is opened, the falling distance of the powder or granular material filled into the container when the gate is opened is shortened, thereby reducing dust generation and the mixing of air from the atmosphere into the powder or granular material.

[0015] The container may be a bag, and the container holding portion may be configured to hold an opening edge at an upper end of the bag. [Effects of the Invention]

[0016] The present invention has the above-described configuration and has an effect of providing a powdered or granular material filling device that can shorten the cycle time. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1(A) is a schematic cross-sectional view showing an example of a powder or granular material filling device according to this embodiment, and FIG. 1(B) is a plan view of a storage section of the powder or granular material filling device as viewed from above. [Figure 2] FIG. 2 is a diagram showing a different state of the powder / granular material filling device shown in FIG. 1(A). [Figure 3] FIG. 3 is a timing chart showing an example of the operation of the powdered or granular material filling device according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Preferred embodiments of the present invention will be described below with reference to the drawings. In the following, identical or corresponding elements will be designated by the same reference numerals throughout the drawings, and redundant explanations will be omitted. The drawings are schematic illustrations of the respective components for ease of understanding, and the shapes, dimensional ratios, and the like may not be accurately depicted. The present invention is not limited to the following embodiments.

[0019] (Embodiment) Fig. 1(A) is a schematic cross-sectional view showing an example of a powdered or granular material filling device according to this embodiment, Fig. 1(B) is a plan view showing a storage section of the powdered or granular material filling device from above, and Fig. 2 is a view showing a different state of the powdered or granular material filling device shown in Fig. 1(A).

[0020] The powder and granular material filling device of this embodiment includes a supply device 1, a storage section 2, a lifting device (first lifting device) 3 that raises and lowers the storage section 2, a bag holding section (container holding section) 4 that holds a bag 50, a weighing section 5 consisting of a load cell or the like that supports the bag holding section 4, a lifting device (second lifting device) 6 that supports the weighing section 5 and raises and lowers the bag holding section 4 and the weighing section 5, and a control device (control section) 7, etc.

[0021] The supply device 1 includes a funnel-shaped hopper 10 for storing powder or granular material, a screw 15 and a motor (e.g., an AC servo motor) 16 for rotating the screw, an agitating blade 17 and a motor 18 for rotating the agitating blade, and the like.

[0022] Hopper 10 has an upper, generally inverted cone-shaped powder / granular material storage section 11 and a lower, cylindrical section 12. A lid 14a is provided at the top end of upper powder / granular material storage section 11, and lid 14a is provided with a powder / granular material inlet 14 through which the powder / granular material is introduced into powder / granular material storage section 11. A stirring blade 17 for stirring the powder / granular material is provided within powder / granular material storage section 11. This stirring blade 17 is attached to a hollow shaft 17a that is rotated by a motor 18. The stirring blade 17 is rotated, for example, when screw 15 rotates.

[0023] A chrysanthemum seat 13 is provided at the lower end of the cylindrical portion 12 at the bottom of the hopper 10. The chrysanthemum seat 13 discharges powder and granules through its gap when the screw 15 rotates, and prevents the powder and granules from falling due to their own weight when the screw 15 stops rotating. The screw 15 has a well-known configuration with spiral fins on the circumferential surface of its rotation shaft 15a, and rotates inside the cylindrical portion 12 to discharge the powder and granules downward.

[0024] In this example, the cylindrical portion 12 is made of porous metal, and an outer pipe 19 is provided around the cylindrical portion 12. The outer pipe 19 is provided with a suction port 19a, which is connected to a vacuum pump 20 via a hose (not shown). With this configuration, when the powder or granular material is discharged from the hopper 10, the vacuum pump 20 is driven to remove air contained in the powder or granular material inside the cylindrical portion 12. This degassing configuration may not be necessary.

[0025] The storage section 2 has a cylindrical body 21 having a generally elliptical cross section and a pair of discharge gates 22 that open and close the opening at the bottom end of the cylindrical body 21. By closing the pair of discharge gates 22, powdered or granular material discharged from the hopper 10 (cylindrical section 12) can be stored. By opening the pair of discharge gates 22, the stored powdered or granular material can be supplied to a bag 50 below, and powdered or granular material discharged from the hopper 10 can be passed through and supplied to the bag 50. A cover 23 made of, for example, rubber may be provided at the opening at the top end of the cylindrical body 21 to close the gap between the cylindrical body 21 and the outer tube 19 of the hopper 10. This cover 23 can reduce dust generation.

[0026] The storage unit 2 has its cylindrical body 21 connected to the lifting device 3 via an appropriate member, and is configured to be able to move up and down by the lifting device 3. For example, the storage unit 2 shown in FIG. 1(A) is shown in a state where it is in its lowest lowered position (D1) in this embodiment, and the storage unit 2 shown in FIG. 2 is shown in a state where it is in its highest raised position (U1) in this embodiment. Therefore, the lifting device 3 is not particularly limited in configuration as long as it is configured to be able to move the storage unit 2 up and down between the lowered position (D1) and the raised position (U1).

[0027] Bag holding unit 4 has a clamping device 41 and a fixing unit 42. Clamping device 41 is configured to clamp the opening edge at the top end of bag 50 and temporarily fix it to fixing unit 42. Fixing unit 42 is fixed to one end of weighing unit 5, such as a load cell, via an appropriate member. The weighing unit 5 measures the total weight of bag 50 held by bag holding unit 4 and the powder or granular material filled in it.

[0028] The other end of the weighing unit 5 is connected to the lifting device 6 via an appropriate member, and the lifting device 6 is configured to lift and lower the bag holding unit 4 together with the weighing unit 5. For example, the bag holding unit 4 shown in FIG. 1(A) is shown in a state in which it is in its lowest lowered position (D2) in this embodiment, and the bag holding unit 4 shown in FIG. 2 is shown in a state in which it is in its highest raised position (U2) in this embodiment. Therefore, the lifting device 6 is not particularly limited in its configuration as long as it is configured to lift and lower the bag holding unit 4 between the lowered position (D2) and the raised position (U2).

[0029] The control device 7 is configured, for example, by a microcomputer or the like, and has an arithmetic and control unit including a CPU or the like and a memory unit including RAM and ROM or the like. The arithmetic and control unit controls the entire powder / granular material filling apparatus by having the CPU execute a control program for the powder / granular material filling apparatus stored in the memory unit. That is, the control device 7 acquires the measurement value from the weighing unit 5 (inputs a measurement signal), controls the rotation of the screw 15 by driving and controlling the motor 16, controls the rotation of the agitating blade 17 by driving and controlling the motor 18, and degasses the powder / granular material in the cylindrical portion 12 by driving the vacuum pump 20. Furthermore, the control device 7 controls the lifting and lowering operations of the lifting devices 3 and 6 and the operation of the clamping device 41. The control device 7 may be configured as a single control device that performs centralized control, or as a plurality of control devices that cooperate with each other to perform distributed control.

[0030] Next, an example of the operation of the powdered or granular material filling device of this embodiment will be described. Figure 3 is a timing chart showing an example of the operation of the powdered or granular material filling device of this embodiment. Figure 3 shows changes over time in the rotational operation (rotational speed) of screw 15, the state of the bags, the open / close state of discharge gate 22, the vertical position (upper / lower position) of storage section 2, and the vertical position (upper / lower position) of bag holding section 4.

[0031] In this embodiment, a bag conveying device (not shown) sequentially conveys empty bags 50 into the bag holding unit 4 and conveys bags 50 filled with powder or granular material out of the bag holding unit 4. Thus, the powder or granular material filling device of this embodiment is configured to repeatedly fill empty bags 50 that are conveyed one after another with powder or granular material.

[0032] Here, the weight (tare weight) of each bag 50 used is a constant fixed value that is set (stored) in advance in the control device 7. The control device 7 also has set (stored) in advance a target weight of the powder or granular material to be filled into the bag 50.

[0033] The weighing value of the weighing unit 5 acquired by the control device 7 is the total weight of the bag 50 and the powder or granular material therein. The control device 7 calculates the net weight (weight of the powder or granular material) by subtracting the tare weight (fixed value) from the weighing value (total weight) of the weighing unit 5.

[0034] In FIG. 3, the period of "bag removal and preparation for attachment" between times t1 and t4, shown as "bag state," is the period from when the bag 50 filled with powder or granular material is removed from the bag holding unit 4 and carried out, until the next empty bag 50 is carried in and attached to the bag holding unit 4. Furthermore, the period of "attachment state" between times t4 and t10 is the period during which the bag 50 is attached to the bag holding unit 4. These periods are repeated for each cycle.

[0035] The control device 7, for example, rotates the screw 15 at a constant high rotational speed (first rotational speed) V1 during the second predetermined time T2 from time t1 to t6, and then gradually slows down the rotational speed (from time t6 to t8) to a predetermined rotational speed (second rotational speed) V2 (from time t8 to t9). In this way, the screw 15 is continuously rotated between times t1 and t9. The rotational speed of the screw 15 and the discharge rate of the granular material from the hopper 10 are approximately proportional. Rotating the screw 15 at a high rotational speed V1 means performing a supply called "large input" with a high discharge rate of the granular material from the hopper 10, and rotating the screw 15 at a low rotational speed V2 means performing a supply called "small input" with a low discharge rate of the granular material from the hopper 10. In this example, when reducing the rotational speed of the screw 15 from rotational speed V1 to V2, it is made to decrease linearly (monotonically decrease) with respect to the passage of time, but it is not limited to this. For example, the rotational speed of the screw 15 may be made to decrease quadratically with respect to the passage of time, or the rate of decrease of the rotational speed may be made proportional to the remaining filling amount (the shortage amount with respect to the target weight).

[0036] Also, when starting to rotate the screw 15 at a high rotational speed V1, the storage part 2 is at the upper position U1, but when the rotation of the screw 15 starts, the storage part 2 is lowered from the upper position U1 to the lower position D1 (from time t1 to t2).

[0037] Then, when the first predetermined time T1 (T1 < T2) has elapsed from time t1, the discharge gate 22 of the storage part 2 is opened (time t5). The granular material discharged from the hopper 10 during the first predetermined time T1 from time t1 to t5 is stored in the storage part 2 with the discharge gate 22 closed. The amount of the granular material stored in this storage part 2 may be, for example, about 5 hundredths to 6 hundredths of the target weight.

[0038] Furthermore, before opening discharge gate 22 of storage unit 2, bag holding unit 4 is raised from lowered position D2 to raised position U2 (times t3 to t4). Then, at time 4, bags 50 are attached to bag holding unit 4. Therefore, before opening discharge gate 22, bag holding unit 4 is in a state of attaching (holding) bags 50 at raised position U2.

[0039] Then, at time t5, when discharge gate 22 is opened, the powder or granular material stored in storage section 2 is supplied to bag 50, and subsequently, the powder or granular material discharged from hopper 10 is supplied to bag 50 (times t5 to t9).

[0040] Furthermore, from the time when discharge gate 22 is opened at time t5 until time t6, reservoir 2 is raised from lowered position D1 to raised position U1 (times t5 to t6).

[0041] Then, at time t6 when the rotation speed of screw 15 is gradually slowed down, bag holding section 4 is gradually lowered from raised position U2 to lowered position D2 (times t6 to t7).

[0042] At time t8, after screw 15 is rotated to slow rotation speed V2, when the net weight (weight of powder or granular material) calculated by subtracting the tare weight from the weighing value (gross weight) of weighing unit 5 reaches the target weight or a predetermined weight that is less than the target weight by the drop correction amount, controller 7 stops the rotation of screw 15 and closes discharge gate 22 (time t9). The drop correction amount is, for example, the weight (set value) of powder or granular material that is expected to be supplied to bag 50 after rotation of screw 15 is stopped. In this example, the target weight and drop correction amount are stored in advance in the memory unit of controller 7.

[0043] Then, after stopping the rotation of the screw 15, the control device 7 determines that the weighed value of the weighing unit 5 has stabilized, and calculates the final net weight (weight of powder or granular material) from that weighed value (time t10). Here, the control device 7 determines that the weighed value of the weighing unit 5 has stabilized, for example, when the amount of fluctuation in the weighed value of the weighing unit 5, which fluctuates up and down, falls within a predetermined range. After this, the "bag removal and attachment preparation" period in the next cycle begins, and the clamping device 41 is released, and the bag 50 filled with powder or granular material is removed from the bag holding unit 4 and carried out. Then, the next empty bag 50 is carried in and attached to the bag holding unit 4.

[0044] In this embodiment, for example, from the time when screw 15 starts to rotate at time t1 until first predetermined time T1 has elapsed, discharge gate 22 of storage section 2 is closed, so the powder or granular material discharged from hopper 10 is temporarily stored in storage section 2. Therefore, during this time, it is possible to remove bags 50 filled with powder or granular material last time from bag holding section 4, or to prepare empty bags 50 to be filled this time by holding them in bag holding section 4, thereby shortening the cycle time.

[0045] Furthermore, after rotating the screw 15 at a high rotation speed V1 for a second predetermined time T2, the rotation speed is gradually slowed down to a slow rotation speed V2, and when the weight of the powder or granular material reaches the target weight or a predetermined weight smaller than the target weight, the rotation of the screw 15 is stopped and the discharge gate 22 is closed, thereby shortening the cycle time and improving the weighing accuracy.

[0046] Furthermore, by starting to rotate the screw 15 at the rotational speed V1 when the storage section 2 is in the raised position U1, the falling distance of the powder or granular material discharged into the storage section 2 is shortened, thereby reducing dust generation and the mixing of air from the atmosphere into the powder or granular material. Subsequently, by lowering the storage section 2 from the raised position U1 to the lowered position D1, a larger amount of powder or granular material can be stored in the storage section 2. Furthermore, by raising the bag holding section 4 holding the empty bag 50 from the lowered position D2 to the raised position U2 before the first predetermined time T1 has elapsed, i.e., before the discharge gate 22 of the storage section 2 is opened, the falling distance of the powder or granular material filled into the bag 50 when the discharge gate 22 is opened is shortened, thereby reducing dust generation and the mixing of air from the atmosphere into the powder or granular material.

[0047] In this embodiment, the weight of the container (bag 50) into which the powder or granular material is to be filled is set in advance as a fixed value in the control device 7, but the weight of the container may be measured each time. In this case, for example, the weight of the container (bag 50) may be measured immediately after time t4 (after the bag 50 is attached), and the discharge gate 22 may be opened after the measurement is completed. In this case, the cycle time may be longer than in the case of FIG. 3 by the time required to measure the weight of the container (bag 50).

[0048] Furthermore, in this embodiment, bags 50 are used as containers for filling powder or granular material, but bottles or the like may also be used. In this case, for example, a mounting table on which a bottle or the like is placed may be provided as the container holding unit, and a load cell or the like that supports this mounting table (container holding unit) may be provided as the weighing unit. Also, an elevating device may be provided that supports the weighing unit and raises and lowers the mounting table together with the weighing unit.

[0049] From the above description, many modifications and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present invention. [Industrial Applicability]

[0050] INDUSTRIAL APPLICABILITY The present invention is useful as a powder / granular material filling device or the like that can shorten the cycle time. [Explanation of symbols]

[0051] 1 Feeding device 10 Hopper 11 Powder and granular material storage section 12 Cylindrical part 15 Screw 2. Storage section 21 Cylinder 22 Discharge gate 3 Lifting device 4 Bag holding part 5 Measuring part 6 Lifting device 7 Control Device 50 bags

Claims

1. A powder / granular material filling device that repeatedly fills a container with a target weight of powder / granular material, A funnel-shaped hopper for storing powder and granular material; a screw that rotates inside a cylindrical portion at the bottom of the hopper to discharge powder and granular material downward; a storage section including a cylinder having openings at the top and bottom and a gate for opening and closing the opening at the bottom end of the cylinder, and capable of temporarily storing the powder or granular material discharged from the hopper within the cylinder; a container holding section that temporarily holds the container filled with the powder or granular material discharged from the hopper and supplied through the storage section; a weighing unit that supports the container holding unit and weighs a total weight of the container and the powder or granular material filled therein; a control unit that continuously rotates the screw to fill the container with the target weight of powder or granular material, stores the powder or granular material in the storage unit with the gate closed until a first predetermined time has elapsed since the screw started to rotate, and opens the gate when the first predetermined time has elapsed, The control unit is the screw is rotated at a first rotation speed for a second predetermined time longer than the first predetermined time, and then the rotation speed is gradually slowed down to rotate at the second rotation speed; and when the weight of the powder or granular material calculated from the total weight measured by the measuring unit becomes the target weight or a predetermined weight smaller than the target weight, the rotation of the screw is stopped and the gate is closed. Powder filling equipment.

2. a first lifting device that lifts and lowers the storage unit between a first lowered position and a first raised position; A second lifting device that lifts and lowers the container holding unit between a second lowered position and a second raised position, The control unit is controlling the first lifting device so that, when the screw starts to rotate at the first rotation speed, the storage unit is lowered from the first elevated position to the first lowered position, and after the first predetermined time has elapsed, the storage unit is elevated from the first lowered position to the first elevated position; the second lifting device is configured to control the container holding unit holding the container to be raised from the second lowered position to the second raised position before the first predetermined time has elapsed, and to lower the container holding unit from the second raised position to the second lowered position while gradually slowing the rotation speed of the screw from the first rotation speed to the second rotation speed.

2. The powder / granular material filling device according to claim 1.

3. the container is a bag; The container holding portion is configured to hold the opening edge of the upper end of the bag.

3. The powder / granular material filling device according to claim 1 or 2.

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