JP7648326B2 - Powder and granular material filling equipment - Google Patents

Description

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

Conventionally, powder and granular material filling devices are known that can fill a container such as a bag with a predetermined amount of powder and granular material.

Patent document 1 describes a quantitative bagging device that, when filling bags with powder or granular material, first pours a large amount at a fast filling speed, then pours a small amount at a slower filling speed, and then reduces the filling speed steplessly during this small pouring.

Patent document 2 also describes an auger filling machine that includes a funnel that contains powder and an auger screw that rotates inside the cylindrical portion of the funnel, and that drops the powder and supplies it to a bottle by rotating the auger screw.

Japanese Patent Application Publication No. 8-292084 Japanese Patent Application Publication No. 1-99641

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 is replaced with the next container and then filling of that container begins. In this case, it takes time to remove the filled container and prepare the next container, resulting in a long cycle time.

The present invention has been made to solve the above problems, and aims to provide a powder and granular material filling device that can shorten the cycle time.

In this specification and claims, the "container" into which the powder or granular material is filled includes bags, bottles, etc.

In order to achieve the above 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 includes a funnel-shaped hopper for storing powdered or granular material, a screw that rotates inside a cylindrical part 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 in the cylindrical body, a container holding section that temporarily holds the container 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, stores the powdered or granular material in the storage section with the gate closed until a first predetermined time has elapsed since the screw began to rotate, and opens the gate when the first predetermined time has elapsed.

According to 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 discharged from the hopper is temporarily stored in the storage section. During this time, it is possible to remove the container that was previously filled with powder (a filled container) from the container holding section, or to prepare the empty container to be filled this time so that it can be held in the container holding section, thereby shortening the cycle time.

The control unit may be configured to rotate the screw at a first rotation speed for a second predetermined time longer than the first predetermined time, and then gradually slow down the rotation speed to rotate at the second rotation speed, and to stop the rotation of the screw and close the gate 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.

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.

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

According to this configuration, by starting to rotate the screw at the first rotation speed when the storage section is in the first raised position, the falling distance of the powder discharged to the storage section is shortened, dust generation can be reduced, and air from the atmosphere can be reduced from mixing with the powder. Then, by lowering the storage section from the first raised position to the first lowered position, a large amount of powder can be stored in the storage section. In addition, by raising the container holding section 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 section is opened, the falling distance of the powder filled into the container when the gate is opened is shortened, and dust generation can be reduced and air from the atmosphere can be reduced from mixing with the powder.

The container may be a bag, and the container holder may be configured to hold the opening edge of the upper end of the bag.

The present invention has the above-described configuration and has the effect of providing a powder/granular material filling device that can shorten the cycle time.

FIG. 1A is a schematic cross-sectional view showing an example of a powdered or granular material filling device according to this embodiment, and FIG. 1B is a plan view showing a storage unit of the powdered or granular material filling device as viewed from above. FIG. 2 is a diagram showing a different state of the powdered material filling apparatus shown in FIG. FIG. 3 is a timing chart showing an example of the operation of the powdered material filling device according to the present embodiment.

Below, preferred embodiments of the present invention will be described with reference to the drawings. Note that, in the following, identical or corresponding elements are given the same reference symbols throughout all the drawings, and duplicated descriptions will be omitted. Also, the drawings show each component diagrammatically to facilitate understanding, and shapes, dimensional ratios, etc. may not be shown accurately. Also, the present invention is not limited to the following embodiments.

(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 unit 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).

The powdered 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 bags 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.

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, and an agitator blade 17 and a motor 18 for rotating the screw.

The hopper 10 has an upper powdered material storage section 11 having a generally inverted cone shape and a lower cylindrical section 12. A lid 14a is provided at the top end of the upper powdered material storage section 11, and a powdered material inlet 14 is provided in the lid 14a, through which the powdered material is introduced into the powdered material storage section 11. A stirring blade 17 for stirring the powdered material is provided in the powdered material storage section 11. The 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 the screw 15 rotates.

A chrysanthemum seat 13 is provided at the lower end of the cylindrical section 12 at the bottom of the hopper 10. The chrysanthemum seat 13 discharges the powdered material from its gap when the screw 15 rotates, and prevents the powdered material from falling due to its own weight when the screw 15 stops rotating. The screw 15 has a well-known configuration with helical fins on the circumferential surface of its rotating shaft 15a, and rotates inside the cylindrical section 12 to discharge the powdered material downward.

In this example, the cylindrical portion 12 is made of porous metal, and an outer tube 19 is provided around the cylindrical portion 12. The outer tube 19 is provided with a suction port 19a, which is connected to a vacuum pump 20 via a hose (not shown). With this configuration, the vacuum pump 20 can be driven when discharging powder from the hopper 10, and the air contained in the powder inside the cylindrical portion 12 can be degassed. There may be cases where this degassing configuration is not provided.

The storage section 2 has a cylinder 21 with a generally elliptical cross section and a pair of discharge gates 22 that open and close the opening at the bottom end of the cylinder 21. By closing the pair of discharge gates 22, the powder discharged from the hopper 10 (cylindrical section 12) can be stored. By opening the pair of discharge gates 22, the stored powder can be supplied to the bag 50 below, and the powder 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 cylinder 21 to close the gap between the cylinder 21 and the outer tube 19 of the hopper 10. This cover 23 can reduce dust generation.

The storage section 2 has its cylindrical body 21 connected to the lifting device 3 via an appropriate member, and is configured to be able to be raised and lowered by the lifting device 3. For example, the storage section 2 shown in FIG. 1(A) is shown in a state in which it is in the lowered most downward position (D1) in this embodiment, and the storage section 2 shown in FIG. 2 is shown in a state in which it is in the uppermost upward position (U1) in this embodiment. Thus, the lifting device 3 is only required to be configured so as to be able to raise and lower the storage section 2 between the lowered position (D1) and the upper position (U1), and its configuration is not particularly limited.

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

The other end of the weighing section 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 section 4 together with the weighing section 5. For example, the bag holding section 4 shown in FIG. 1(A) is shown in a state in which it is in the lowered, most downward position (D2) in this embodiment, and the bag holding section 4 shown in FIG. 2 is shown in a state in which it is in the uppermost upward position (U2) in this embodiment. Therefore, the lifting device 6 is only required to be configured to lift and lower the bag holding section 4 between the lowered position (D2) and the upper position (U2), and its configuration is not particularly limited.

The control device 7 is, for example, a microcomputer, and has a calculation control section made up of a CPU, etc., and a storage section made up of a RAM and a ROM, etc. The calculation control section controls the entire powdered material filling device by executing a control program for the powdered material filling device stored in the storage section by the CPU. That is, the control device 7 acquires a measurement value from the measuring section 5 (inputs a measurement signal), controls the rotation of the screw 15 by driving and controlling the motor 16, controls the rotation of the stirring blade 17 by driving and controlling the motor 18, and degass the powdered material in the cylindrical section 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 clamp device 41. The control device 7 may be configured as a single control device that performs centralized control, or may be configured as a plurality of control devices that cooperate with each other to perform distributed control.

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

In this embodiment, an empty bag 50 is transported into the bag holding section 4 by a bag transport device (not shown), and bags 50 filled with powder or granular material are transported out of the bag holding section 4 in sequence. Therefore, the powder or granular material filling device of this embodiment is configured to repeatedly fill the empty bags 50 that are transported one after another with powder or granular material.

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

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 contained therein. The control device 7 calculates the net weight (weight of powder or granular material) by subtracting the tare weight (fixed value) from the weighing value (total weight) of the weighing unit 5.

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

For example, the control device 7 rotates the screw 15 at a constant high rotation speed (first rotation speed) V1 for a second predetermined time T2 from time t1 to t6, and then gradually slows down the rotation speed (time t6 to t8) to a predetermined rotation speed (second rotation speed) V2 (time t8 to t9). In this way, the screw 15 is rotated continuously from time t1 to t9. The rotation speed of the screw 15 and the discharge speed of the powder from the hopper 10 are approximately proportional, and rotating the screw 15 at the high rotation speed V1 is a supply of "large input" in which the discharge speed of the powder from the hopper 10 is fast, and rotating the screw 15 at the low rotation speed V2 is a supply of "small input" in which the discharge speed of the powder from the hopper 10 is slow. In this example, when the rotation speed of the screw 15 is reduced from the rotation speed V1 to V2, it is reduced linearly (monotonically) with respect to the passage of time, but this is not limited to this. For example, the rotation speed of the screw 15 may be decreased quadratically over time, or the rate of decrease in the rotation speed may be made proportional to the remaining amount of filling (the amount that is short of the target weight).

When the screw 15 starts to rotate at the high rotation speed V1, the storage section 2 is in the raised position U1, but when the screw 15 starts to rotate, the storage section 2 is lowered from the raised position U1 to the lowered position D1 (time t1 to t2).

Then, when the first predetermined time T1 (T1<T2) has elapsed from time t1, the discharge gate 22 of the storage section 2 is opened (time t5). The powder or granular material discharged from the hopper 10 during the first predetermined time T1 from time t1 to t5 is stored in the storage section 2 with the discharge gate 22 closed. The amount of powder or granular material stored in this storage section 2 may be, for example, about 50-60% of the target weight.

Before the discharge gate 22 of the storage section 2 is opened, the bag holding section 4 is raised from the lowered position D2 to the raised position U2 (times t3 to t4). Then, at time 4, the bag 50 is attached to the bag holding section 4. Therefore, before the discharge gate 22 is opened, the bag holding section 4 is in a state of having the bag 50 attached (held) at the raised position U2.

Then, at time t5, the discharge gate 22 is opened and the powder stored in the storage section 2 is supplied to the bag 50, and then the powder discharged from the hopper 10 is supplied to the bag 50 (times t5 to t9).

In addition, from the time t5 when the discharge gate 22 is opened until time t6, the storage section 2 is raised from the lowered position D1 to the raised position U1 (times t5 to t6).

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

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

After the control device 7 has stopped the rotation of the screw 15, and has determined that the weighing value of the weighing unit 5 has stabilized, it calculates the final net weight (weight of powder or granular material) from that weighing value (time t10). Here, the control device 7 determines that the weighing value of the weighing unit 5 has stabilized, for example, when the amount of fluctuation in the weighing value of the weighing unit 5, which fluctuates up and down, falls within a predetermined range. After this, the period of "bag removal and installation preparation" 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 transported out. Then, the next empty bag 50 is transported and attached to the bag holding unit 4.

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

In addition, the screw 15 is rotated at a high rotation speed V1 for a second predetermined time T2, and then the rotation speed is gradually slowed down to rotate at a low rotation speed V2. 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.

When the storage section 2 is in the raised position U1, the screw 15 starts to rotate at the rotation speed V1, thereby shortening the falling distance of the powder discharged to the storage section 2, reducing dust generation and reducing the mixing of air in the atmosphere with the powder. After that, the storage section 2 is lowered from the raised position U1 to the lowered position D1, allowing a large amount of powder to 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 filled into the bag 50 when the discharge gate 22 is opened is shortened, reducing dust generation and reducing the mixing of air in the atmosphere with the powder.

In this embodiment, the weight of the container (bag 50) in which the powder or granular material is filled is set in advance in the control device 7 as a constant fixed value, 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).

In addition, in this embodiment, a bag 50 is used as a container for filling the powder or granular material, but a bottle or the like may also be used. In this case, for example, a platform 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 platform (container holding unit) may be provided as the weighing unit. Also, a lifting device may be provided that supports the weighing unit and raises and lowers the platform together with the weighing unit.

From the above description, many improvements 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 of carrying out the present invention. The details of the structure and/or function of the present invention may be substantially changed without departing from the spirit of the present invention.

The present invention is useful as a powder/granular material filling device that can shorten cycle times.

Reference Signs List 1: Supply device 10: Hopper 11: Powder/granular material storage section 12: Cylindrical section 15: Screw 2: Storage section 21: Cylinder body 22: Discharge gate 3: Lifting device 4: Bag holding section 5: Weighing section 6: Lifting device 7: Control device 50: Bag

Claims (3)

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 and granular material filling equipment. 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;
and controlling the second lifting device so as to lift the container holding part holding the container from the second lowered position to the second raised position before the first predetermined time has elapsed, and to lower the container holding part 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 . 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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