JP7462516B2 - Stirring device and stirring method - Google Patents

Description

Embodiments of the present invention relate to a stirring device and a stirring method.

In a powder mixing device, the powder and liquid are put into a container (tank), and when the powder and liquid are brought into contact with each other, for example, by an agitator blade, the powder is dispersed in the liquid by forces such as shear stress. In this case, the affinity (wettability) between the powder and liquid may be low. If the affinity is low, the powder will remain floating on the liquid surface, and dispersion will not progress easily even if the powder and liquid are stirred by the agitator blade. For this reason, there is a demand to shorten the time required for dispersion of the powder and liquid, even when the affinity between the powder and liquid is low.

Japanese Utility Model Application Publication No. 63-111927

The problem that this invention aims to solve is to provide an agitation device and an agitation method that can efficiently disperse powder into liquid.

According to an embodiment, the stirring device includes a storage unit, a stirring unit, a drive unit, and a control unit. The storage unit stores liquid. The stirring unit is movable in the height direction of the storage unit and disperses powder into the liquid stored in the storage unit. The drive unit drives the stirring unit. The control unit controls the position of the stirring unit in the height direction based on the dispersion state of the powder in the liquid.

According to an embodiment, in the stirring method, liquid is stored in a storage section. In the stirring method, powder is dispersed in the liquid by driving the stirring section in the liquid stored in the storage section. In the stirring method, the position of the stirring section in the height direction of the storage section is controlled based on the dispersion state of the powder in the liquid.

FIG. 1 is a schematic diagram illustrating an example of a stirring device according to an embodiment. FIG. 2 is an example of a block diagram of the stirring device according to the embodiment. FIG. 3 is a graph showing an example of changes in state parameters when a liquid and a powder having low affinity for each other are dispersed in the stirring device of the embodiment. FIG. 4 shows an example of a process executed by the control unit before adding powder to liquid when a liquid and powder that have low affinity for each other are dispersed in the stirring device of the embodiment. FIG. 5 shows an example of a process executed by the control unit after the powder is poured into the liquid when a liquid and a powder that have low affinity for each other are dispersed in the stirring device of the embodiment.

The following describes the embodiment with reference to the drawings.

(Embodiment)
1 shows an example of a stirring device 1 according to an embodiment. In the stirring device 1, a height direction (direction indicated by arrows Z1 and Z2) that coincides or substantially coincides with the vertical direction is defined. In addition, in the stirring device 1, a first horizontal direction (direction indicated by arrows X1 and X2) that intersects (perpendicular or substantially perpendicular) with the height direction, and a second horizontal direction that intersects (perpendicular or substantially perpendicular) with both the height direction and the first horizontal direction are defined.

As shown in FIG. 1, the stirring device 1 includes a storage section 2, a liquid supply section 3, a powder supply section 4, a stirring section 5, a drive section 6, a moving mechanism 7, a discharge section 8, and a processing device 9. The storage section 2 stores the liquid 10 and the powder 11 used in the stirring device 1. The storage section 2 is, for example, a cylindrical or approximately cylindrical container with a bottom. In this embodiment, the dimension of the storage section 2 in the height direction is much larger than the dimensions in the first horizontal direction and the second horizontal direction. The liquid supply section 3 supplies the liquid 10 used in the stirring device 1 to the storage section 2. The powder supply section 4 supplies the powder 11 used in the stirring device 1 to the storage section 2. The liquid supply section 3 and the powder supply section 4 are provided at the top of the storage section 2 in the height direction. The affinity (wettability) between the liquid 10 supplied from the liquid supply section 3 and the powder 11 supplied from the powder supply section 4 is low. The affinity (wettability) mainly refers to the ease with which the liquid adheres to the surface of the powder. In this embodiment, the liquid 10 is a dispersion medium that disperses the powder 11. In one example, the combination of the liquid 10 supplied from the liquid supply unit 3 and the powder 11 supplied from the powder supply unit 4 is a water-based liquid and a carbon material. Note that in this embodiment, the liquid supply unit 3 and the powder supply unit 4 are provided separately, but the liquid supply unit 3 and the powder supply unit 4 may be integrated. In one example, the liquid 10 and the powder 11 are supplied to the storage unit 2 through one supply unit.

The stirring unit 5 stirs the liquid 10 and powder 11 supplied inside the storage unit 2. The stirring unit 5 is disposed inside the storage unit 2. The stirring unit 5 is, for example, a stirring blade. Examples of the stirring blade include, but are not limited to, a propeller-shaped stirring blade and a disk-shaped stirring blade. The drive unit 6 is connected to the stirring unit 5 by the connection unit 12. In this embodiment, the connection unit 12 is a shaft. As a result, the drive unit 6 becomes a driving source that drives the stirring unit 5. The stirring unit 5 stirs the liquid 10 and powder 11 inside the storage unit 2 by being driven by the drive unit 6. In this embodiment, as shown by the arrow in FIG. 1, the stirring unit 5 can rotate around the connection unit 12 as an axis by being driven by the drive unit 6. In one example, the connection unit 12 and the stirring unit 5 are located in the center of the storage unit 2 in both the first horizontal direction and the second horizontal direction. That is, the connection part 12 and the stirring part 5 are located at the center of the storage part 2 in a cross section perpendicular or approximately perpendicular to the height direction. In another example, the connection part 12 and the stirring part 5 are located at a position shifted from the center of the storage part 2 in a cross section perpendicular or approximately perpendicular to the height direction, that is, at a position eccentric from the center of the storage part 2.

The moving mechanism 7 moves the connection part 12 in the height direction. The connection part 12 can be moved upward or downward along the height direction by being driven by the moving mechanism 7. The moving mechanism 7 moves the connection part 12 and the stirring part 5 attached to the connection part 12 together along the height direction, thereby moving the stirring part 5 in the height direction. The discharge part 8 discharges the liquid 10 and the powder 11 inside the storage part 2 after the dispersion of the liquid 10 and the powder 11 is completed in the stirring device 1. The discharge part 8 is provided at the bottom of the storage part 2 in the height direction. The processing device 9 rotates the stirring part 5 by controlling the driving of the driving part 6. The processing device 9 moves the connection part 12 and the stirring part 5 along the height direction by controlling the moving mechanism 7. Note that the rotation of the stirring part 5 and the movement along the height direction of the stirring part 5 and the connection part 12 may each be driven by the same driving part.

Figure 2 shows an example of a block diagram of the stirring device 1 according to the embodiment. The processing device 9 of the stirring device 1 includes a control unit 13 and a detection unit 14. The processing device 9 is, for example, a computer. The processing device 9 includes a processor or integrated circuit (control circuit) including a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), and a storage medium such as a memory. The processing device 9 may include one processor or integrated circuit, or may include multiple processors or integrated circuits. The processing device 9 executes a program or the like stored in a storage medium or the like to perform processing. The detection unit 14 may be provided separately from the processing device 9.

The control unit 13 controls the drive of the drive unit 6 and the movement mechanism 7. As a result, the rotation of the agitation unit 5 connected to the drive unit 6 is controlled. In addition, the movement of the connection unit 12 along the height direction is controlled in the connection unit 12 connected to the movement mechanism 7. In this embodiment, since the agitation unit 5 is attached to the connection unit 12, the agitation unit 5 moves along the height direction along with the movement of the connection unit 12 along the height direction. The rotation speed of the agitation unit 5 and the movement speed of the connection unit 12 (agitation unit 5) along the height direction may be set in advance by an operator or the like via a user interface 15 or the like described later. In addition, the rotation speed and the movement speed may be set in accordance with the combination of the liquid 10 and the powder 11. In one example, the control unit 13 maintains the rotation speed of the agitation unit 5 constant or approximately constant regardless of the viscosity of the liquid 10. The rotation speed of the agitation unit 5 is, for example, 1800 rpm. The movement speed of the connection unit 12 (agitation unit 5) along the height direction is, for example, about 10 cm/s.

The detection unit 14 detects state parameters of the liquid 10 and powder 11 stored in the storage unit 2. The state parameters are parameters that indicate the state of dispersion (dispersion state) of the powder 11 in the liquid 10 stored in the storage unit 2. The state parameters may be parameters that directly indicate the state of dispersion of the powder 11 in the liquid 10, or may be parameters that indirectly indicate the state of dispersion of the powder 11 in the liquid 10. In other words, the state parameters may be parameters that change (vary) in response to the state of dispersion of the powder 11 in the liquid 10. In this embodiment, the detection unit 14 detects the drive parameters of the drive unit 6 as the state parameters. The drive parameters are parameters related to the drive of the drive unit 6. The drive parameters include a load current value required to drive the drive unit 6 and a torque value of the drive unit 6. The detection unit 14 detects at least one of the load current value of the drive unit 6 and the torque value of the drive unit 6 as the state parameters.

The state parameter varies according to the state of dispersion of the powder 11 in the liquid 10. When the stirring unit 5 stirs the liquid 10 and the powder 11 to advance the dispersion of the liquid 10 and the powder 11, the value of the state parameter decreases. In other words, when the dispersion of the liquid 10 and the powder 11 is not progressing, the value of the state parameter is relatively large, and when the dispersion of the liquid 10 and the powder 11 is progressing, the value of the state parameter is relatively small. Furthermore, when the powder 11 is sufficiently dispersed in the liquid 10, the value of the state parameter becomes close to the value of the state parameter of the liquid 10 when the powder 11 is not contained in the liquid 10.

Even when the load current value and/or torque value are used as the drive parameters, the value is relatively large when the dispersion of the liquid 10 and the powder 11 is not progressing, and the value is relatively small when the dispersion of the liquid 10 and the powder 11 is progressing. When the load current value and/or torque value are used as the drive parameters, the value when the agitator 5 is in the liquid 10 is larger than the value when the agitator 5 is outside the liquid 10. In other words, the value of the drive parameter when the agitator 5 is located below the liquid surface of the liquid 10 in the height direction is larger than the value of the drive parameter when the agitator 5 is located above the liquid surface of the liquid 10 in the height direction.

In the stirring device 1 of this embodiment, a user interface 15 may be provided. The user interface 15 includes an operating member. In the operating member, commands related to the operation of the stirring device 1 are input by an operator or the like. Examples of the operating member include a button, a dial, and a touch panel. The user interface 15 may also include a notification unit that notifies the operator or the like of information. The notification unit notifies by displaying a screen, emitting a sound, turning on a light, etc. The notification unit notifies, for example, information that needs to be recognized by the operator, and warning information for the operator, etc.

Figure 3 is a schematic diagram showing an example of the change over time of the load current value during stirring. In Figure 3, the horizontal axis indicates the elapsed time from the supply of liquid 10 to the storage section 2, and the vertical axis indicates the load current value. Also, curve α indicates the change over time of the load current value. In the example of Figure 3, at time t0, liquid 10 begins to be supplied to the storage section 2 through the liquid supply section 3. When the supply of liquid 10 to the storage section 2 is completed at time t1, the stirring section 5 begins to rotate in the liquid 10. Then, at time t2, powder 11 begins to be supplied to the storage section 2 through the powder supply section 4. That is, between time t1 and time t2, liquid 10 is stored in the storage section 2, and powder 11 is not supplied to the storage section 2. The storage state of the storage section 2 between time t1 and time t2 is defined as the reference state. That is, the storage state of the storage unit 2 from when the supply of the liquid 10 is completed until the powder 11 is added to the liquid 10 is defined as the reference state. In addition, the position of the stirring unit 5 in the height direction in the reference state is defined as the initial position.

In the reference state, the value of the state parameter (load current value) detected by the detection unit 14 is set as the parameter reference value S0. The parameter reference value S0 is the value of the state parameter of the liquid 10 that does not contain the powder 11. The parameter reference value S0 may be one value of the state parameter in the reference state, or may be a value calculated from multiple values of the state parameter in the reference state. In one example, the parameter reference value S0 is an average value of multiple values of the state parameter acquired in the reference state. When the dispersion of the powder 11 in the liquid 10 progresses sufficiently, the value of the state parameter becomes close to the value of the state parameter of the liquid 10 that does not contain the powder 11, that is, the parameter reference value S0. In addition, a reference range S including the parameter reference value S0 is specified. The lower limit of the reference range S is S1, and the upper limit of the reference range S is S2. S1 and S2 are appropriately set depending on the combination of the liquid 10 and the powder 11. In one example, S1 and S2 are set in advance by an operator or the like via a user interface 15 or the like.

When the powder 11 starts to be supplied at time t2, the load current value starts to rise. In this state, in the storage section 2, the powder 11 is present in a greater amount in the upper portion in the height direction of the liquid 10. In the example of FIG. 3, the curve α increases monotonically after time t2. When the load current value exceeds the upper limit value S2 of the reference range S at or just before time t3, the stirring section 5 starts to rise upward in the height direction by the moving mechanism 7. A part of the powder 11 in the liquid 10 moves upward in the height direction of the liquid 10 together with the stirring section 5. As the stirring section 5 rises, the amount of powder 11 present at the position of the stirring section 5 increases, so the load current value increases over time. At time t4, a certain amount of time has passed since time t3, the dispersion of the liquid 10 and the powder 11 progresses and the stirring section 5 approaches the liquid surface of the liquid 10. When the stirring section 5 is located near the liquid surface of the liquid 10, the rate of change of the load current value becomes smaller. That is, between time t3 and time t4, the slope of curve α gradually decreases as time progresses. Then, at time t4, the change in the load current value over time switches from increasing to decreasing. In other words, in FIG. 3, the slope of curve α is positive between time t3 and time t4, becomes 0 at time t4, and becomes negative beyond time t4.

At time t4 or the time immediately before, the movement of the stirring unit 5 in the height direction switches from rising to falling. That is, the stirring unit 5 starts to descend downward in the height direction by the moving mechanism 7. The position of the stirring unit 5 in the height direction at time t4 or the time immediately before is the upper limit position of the stirring unit 5. A part of the powder 11 in the liquid 10 moves downward in the height direction of the liquid 10 together with the stirring unit 5. As the stirring unit 5 descends, the dispersion of the liquid 10 and the powder 11 progresses, so that the load current value decreases over time. In the example of FIG. 3, the curve α decreases monotonically after time t4. At time t5 or the time immediately before, when the load current value falls below the upper limit value S2 of the reference range S, the movement of the stirring unit 5 in the height direction is stopped by the moving mechanism 7. The position of the stirring unit 5 in the height direction at time t5 or the time immediately before is the stop position of the stirring unit 5. In one example, the stop position of the stirring unit 5 is located lower in the height direction than the upper limit position and higher in the height direction than the initial position. In other words, the stop position of the stirring unit 5 is located between the upper limit position and the initial position in the height direction.

After time t5, the stirring unit 5 is stopped at the stop position in the height direction and continues to rotate at the stop position. If the stirring unit 5 continues to rotate at the stop position, the load current value increases over time. This is because the powder 11 is temporarily biased in the liquid 10 during the process of dispersing the powder 11 in the liquid 10. In the example of FIG. 3, the curve α increases monotonically after time t5. At time t6, a certain amount of time has passed since time t5, the dispersion of the liquid 10 and the powder 11 progresses sufficiently. This reduces the rate of change of the load current value. That is, between time t5 and time t6, the slope of the curve α gradually decreases as time progresses. Then, at or just before time t6, the change in the load current value over time switches from an increase to a decrease. In other words, in FIG. 3, the slope of the curve α is positive between time t5 and time t6, becomes 0 at or just before time t6, and becomes negative after time t6. Then, at time t7 immediately after the change over time in the load current value switches from increasing to decreasing, the rotation of the agitator 5 is stopped by the driver 6. In this manner, in the example shown in FIG. 3, the powder 11 is dispersed in the liquid 10 by the agitator 1.

Figure 4 shows an example of a process executed by the control unit 13 before the powder 11 is added to the liquid 10. Figure 5 shows an example of a process executed by the control unit 13 after the powder 11 is added to the liquid 10. The processes in Figures 4 and 5 are executed by the control unit 13 every time a stirring operation is performed in the stirring device 1. Therefore, the processes in Figures 4 and 5 show the processes executed in one stirring operation of the stirring device 1. In the following description, time t is defined as a time variable. Then, the load current value I(t) at time t is defined. In the stirring device 1, the load current value I(t) is periodically detected by the detection unit 14. The control unit 13 periodically acquires the load current value I(t). It is preferable that the time interval for detecting the load current value I(t) is 0.1 seconds or more and 1 second or less.

In the stirring device 1, the liquid 10 is supplied to the storage section 2 through the liquid supply section 3. At this stage, the liquid 10 is stored in the storage section 2, and the powder 11 is not supplied to the storage section 2. The stirring section 5 is located at the lower part of the storage section 2 in the height direction, i.e., the initial position described above, and the liquid level of the liquid 10 is located above the stirring section 5 in the height direction. As shown in FIG. 4, the control section 13 controls the driving of the drive section 6 to rotate the stirring section 5 (S101). The control section 13 does not stop the rotation of the stirring section 5 until the dispersion of the liquid 10 and the powder 11 in the stirring device 1 is completed. That is, the stirring section 5 continues to rotate until the dispersion of the liquid 10 and the powder 11 is completed. When the stirring section 5 is rotating, the detection section 14 detects the state parameter, and the control section 13 acquires the state parameter (S102). In S102, the state parameter may be acquired only once, or may be acquired multiple times. In this embodiment, the control unit 13 acquires the load current value I(t) of the drive unit 6 described above as a state parameter. Based on the state parameter acquired in S102, the control unit 13 sets the parameter reference value S0 for the load current value I(t) and sets the reference range S (S103).

When the powder 11 is supplied to the storage section 2 through the powder supply section 4, the state parameter fluctuates. As shown in FIG. 5, the control section 13 compares the state parameter with the upper limit value S2 of the reference range S (S201). In this embodiment, the load current value I(t) is used as the state parameter, so the control section 13 compares the load current value I(t) with the upper limit value S2 of the reference range S. If the load current value I(t) is equal to or less than the upper limit value S2 (S201-No), the process returns to S201, and the processes from S201 onwards are performed sequentially. If the load current value I(t) is greater than the upper limit value S2 (S201-Yes), the control section 13 controls the moving mechanism 7 to move the stirring section 5 upward in the height direction from the initial position (S202). That is, the control section 13 controls the moving mechanism 7 to move the connection section 12 and the stirring section 5 together upward in the height direction. The speed of movement (ascent speed) of the stirring unit 5 upward in the height direction is not particularly limited as long as it is a speed at which fluctuations in the load current value I(t) can be detected. The ascent speed may be, for example, 10 cm/s, or may be greater than 0 cm/s and less than 10 cm/s.

When the stirring unit 5 moves upward in the height direction, the state parameter changes. The control unit 13 determines whether the load current value I(t) has decreased over time (S203). In one example, the control unit 13 determines whether the load current value I(t) has decreased by comparing the real-time load current value I(t) with the load current value I(t-1) at the time of the previous detection. In another example, the control unit 13 determines whether the load current value I(t) has decreased based on the value dI(t)/dt obtained by time-differentiating the real-time load current value I(t). If the load current value I(t) has not decreased (S203-No), the process returns to S202, and the processes from S202 onwards are performed sequentially. If the load current value I(t) has decreased (S203-Yes), the control unit 13 controls the moving mechanism 7 to move the stirring unit 5 downward in the height direction (S204). That is, the control unit 13 controls the movement mechanism 7 to move the connection unit 12 and the stirring unit 5 together downward in the height direction. In this way, the height position of the stirring unit 5 where the load current value I(t) starts to decrease is the upper limit position of the stirring unit 5. The control unit 13 controls the position of the stirring unit 5 within a range that does not exceed the upper limit position in the height direction. The speed at which the stirring unit 5 moves downward in the height direction (descending speed) may be the same as the ascending speed of the stirring unit 5, or may be a speed different from the ascending speed. In this embodiment, the descending speed of the stirring unit 5 is the same as or almost the same as the ascending speed.

When the stirring unit 5 moves downward in the height direction from the upper limit position, the state parameter changes. The control unit 13 compares the load current value I(t) with the upper limit value S2 of the reference range S (S205). If the load current value I(t) is equal to or greater than the upper limit value S2 (S205-No), the process returns to S204, and the processes from S204 onwards are carried out sequentially. If the load current value I(t) is smaller than the upper limit value S2 (S205-Yes), the control unit 13 controls the movement mechanism 7 to stop the movement of the stirring unit 5 downward in the height direction (S206). In this way, the position in the height direction of the stirring unit 5 where the load current value I(t) is smaller than the upper limit value S2 of the reference range S is the stopping position of the stirring unit 5.

With the stirring unit 5 held in the stopped position, the control unit 13 controls the driving of the drive unit 6 to maintain the rotation of the stirring unit 5 (S207). This allows the dispersion of the liquid 10 and the powder 11 to proceed, and the state parameter fluctuates. The control unit 13 determines whether the load current value I(t) has decreased over time (S208). In S208, the control unit 13 determines whether the load current value I(t) has decreased, in the same manner as in S203. If the load current value I(t) has not decreased (S208-No), the process returns to S207, and the processes from S207 onwards are carried out in sequence. If the load current value I(t) has decreased (S208-Yes), the control unit 13 controls the driving of the drive unit 6 to stop the rotation of the stirring unit 5 (S209). This completes the dispersion of the liquid 10 and the powder 11.

The stirring device 1 may also have a fully automatic mode controlled based on the state parameters described above, and a time setting mode in which the stirring unit 5 is moved in the height direction based on commands input via the user interface 15. In the time setting mode, the control unit 13 sets the time for which the stirring unit 5 and the moving mechanism 7, etc., continue to perform a predetermined operation based on commands input via the user interface 15. Note that the fully automatic mode and the time setting mode can be switched between each other.

In one example, the control unit 13 sets the time for which the stirring unit 5 continues to rotate while stopped at a certain position in the height direction. In this case, the control unit 13 may set the time for which the stirring unit 5 rotates while stopped at the above-mentioned upper limit position to 5 minutes, and the time for which the stirring unit 5 rotates while stopped at the above-mentioned stop position to 10 minutes. In this example, the control unit 13 controls the movement mechanism 7 to move the stirring unit 5 to the above-mentioned upper limit position as described above, and then rotates the stirring unit 5 at the upper limit position for 5 minutes. After 5 minutes have passed, the control unit 13 controls the movement mechanism 7 to move the stirring unit 5 to the above-mentioned stop position as described above, and then rotates the stirring unit 5 at the stop position for 10 minutes. After 10 minutes have passed, the control unit 13 controls the drive of the drive unit 6 to stop the rotation of the stirring unit 5. Note that the rotation time of the stirring unit 5 at the upper limit position and the rotation time of the stirring unit 5 at the stop position are not particularly limited, and are set appropriately based on the combination of the liquid 10 and the powder 11, etc.

In another example, the control unit 13 sets the time for the stirring unit 5 to repeatedly move back and forth in the height direction between the upper limit position and the initial position. In this case, the control unit 13 may set the time for the stirring unit 5 to repeatedly move back and forth in the height direction to 15 minutes. In this example, the control unit 13 controls the moving mechanism 7 to switch the stirring unit 5 to a state in which it moves downward immediately after moving the stirring unit 5 to the upper limit position as described above. Then, the stirring unit 5 is moved to the initial position as described above. The control unit 13 controls the moving mechanism 7 to switch the stirring unit 5 to a state in which it moves upward immediately after moving the stirring unit 5 to the initial position as described above. Then, the stirring unit 5 is moved again to the upper limit position as described above. The control unit 13 controls the moving mechanism 7 to repeatedly move the stirring unit 5 in the height direction for 15 minutes as described above. After 15 minutes have passed, the control unit 13 controls the driving of the drive unit 6 to stop the rotation of the stirring unit 5. When the rotation of the stirring unit 5 stops, it is preferable that the stirring unit 5 stops at the initial position or at a position almost the same as the initial position in the height direction. The time for which the stirring unit 5 repeats reciprocating movements in the height direction is not particularly limited, and is set appropriately based on the combination of the liquid 10 and the powder 11, etc.

In this embodiment, the control unit 13 moves the stirring unit 5 in the height direction based on a state parameter indicating the state of the powder in the liquid. This forcefully stirs the liquid 10 and powder 11 supplied to the storage unit 2, dispersing the powder 11 in the liquid 10. Therefore, even if the affinity between the liquid 10 and the powder 11 is low, the stirring device 1 according to the embodiment can disperse the powder in the liquid in a short time. In addition, since the stirring device 1 according to the embodiment can disperse the powder in the liquid in a short time, the production volume of the powder (material) that is difficult to disperse dispersed in the liquid can be increased by using the stirring device 1 according to the embodiment. Furthermore, the increased production volume can contribute to reducing capital investment.

In this embodiment, the control unit 13 moves the stirring unit 5 in the height direction in response to changes in the drive parameters. This allows the control unit 13 to move the stirring unit 5 in the height direction in response to the dispersion state of the liquid 10 and powder 11 supplied to the storage unit 2. Therefore, even if the affinity between the liquid 10 and the powder 11 is low, the stirring device 1 can disperse the powder in the liquid in a shorter time.

In this embodiment, when the stirring unit 5 is located at the initial position in the height direction, the control unit 13 moves the stirring unit 5 from the initial position to the upper side in the height direction based on the fact that the driving parameter becomes larger than the reference range. When the stirring unit 5 is moved from the initial position to the upper side in the height direction, the control unit 13 moves the stirring unit 5 to the lower side in the height direction based on the fact that the change over time of the driving parameter switches from an increase to a decrease. As a result, the stirring unit 5 does not exceed the liquid level of the liquid 10 stored in the storage unit 2 in the height direction. Also, as shown in FIG. 1, a part of the powder 11 present on the upper side in the height direction (near the liquid level) is moved to the lower side in the height direction (in the liquid 10) with the movement of the stirring unit 5 as described above. Therefore, even if the affinity between the liquid 10 and the powder 11 is low, the stirring device 1 can disperse the powder in the liquid in a shorter time.

In this embodiment, the control unit 13 stops the movement of the stirring unit 5 in the height direction based on the fact that the drive parameters fall within a reference range while the stirring unit 5 is moving downward in the height direction. This causes the powder 11 present in the liquid 10 to be dispersed into the liquid 10 as shown in FIG. 1. Therefore, even if the affinity between the liquid 10 and the powder 11 is low, the stirring device 1 can disperse the powder into the liquid in an even shorter time.

In this embodiment, the control unit 13 stops the rotation of the agitator 5 based on the fact that the change over time in the drive parameter has switched from increasing to decreasing while the movement of the agitator 5 in the height direction has stopped. This allows the agitation by the agitator 1 to end immediately or almost immediately after the dispersion of the liquid 10 and powder 11 has been completed. Therefore, the agitator 1 can reduce unnecessary agitation time and can efficiently perform the task of dispersing the powder in the liquid.

In this embodiment, the stirring section 5 may be eccentric in at least one of the first and second horizontal directions with respect to the center of the storage section 2. This allows the liquid 10 and powder 11 stored in the storage section 2 to be stirred more efficiently, so that the powder can be dispersed in the liquid in an even shorter time.

(Modification)
In a modified example, when the load current value I(t) is decreased as described above (S208-Yes), the control unit 13 may control the moving mechanism 7 to move the stirring unit 5 connected to the connection unit 12 downward in the height direction to the initial position. In this case, the rotation of the stirring unit 5 is not stopped. That is, the control unit 13 moves the stirring unit 5 downward in the height direction while rotating the stirring unit 5, and stops the downward movement in the height direction at the initial position. The control unit 13 controls the drive unit 6 to rotate the stirring unit 5 at the initial position for a certain period of time. Thereafter, the control unit 13 controls the drive unit 6 to stop the rotation of the stirring unit 5. In this modified example, the stirring device 1 executes the same control as described above, and therefore the same actions and effects as those of the above-mentioned embodiment and the like are achieved.

In one modified example, the agitator 1 may be provided with a connection port that can be connected to a vacuum device. The connection port is formed in an upper portion in the height direction of the storage section 2. By connecting a vacuum device (chamber) to the connection port, the liquid 10 and the powder 11 can be degassed after dispersion is completed. In other words, the liquid 10 and the powder 11 can be degassed without transferring them to another device (container). In addition, in this modified example, the agitator 1 executes the same control as described above, and therefore the same actions and effects as those of the above-mentioned embodiment are achieved.

In the above-mentioned embodiment, the control unit 13 controls the driving of the driving unit 6 based on the state parameters detected by the detection unit 14, and moves the stirring unit 5 in the height direction, but this is not limited to the above. In a modified example, the stirring device 1 is provided with a photographing device such as a camera. The control unit 13 acquires the above-mentioned state parameters based on the images and/or videos captured by the photographing device. Then, the control unit 13 controls the driving and moving mechanism 7 of the driving unit 6 based on the state parameters, rotates the stirring unit 5, and moves the stirring unit 5 (connection unit 12) in the height direction. In this case, the position information of the powder 11 in the captured image of the camera becomes the state parameter. Then, the position information of the powder 11 is specified based on either the brightness or the color in the captured image. In this modified example, the stirring device 1 executes the same control as described above, and therefore the same action and effect as the above-mentioned embodiment are achieved.

In at least one of these embodiments, the stirring device includes a storage unit, a stirring unit, a drive unit, and a control unit. The storage unit stores the liquid. The stirring unit is movable in the height direction of the storage unit and disperses powder into the liquid. The drive unit is connected to the stirring unit and rotates the stirring unit by rotary drive. The control unit moves the stirring unit in the height direction based on the dispersion state of the powder in the liquid. This allows the powder to be efficiently dispersed in the liquid.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

Reference Signs List 1: Stirring device, 2: Storage section, 5: Stirring section, 6: Drive section, 10: Liquid, 11: Powder, 13: Control section.

Claims (7)

A storage section for storing liquid;
an agitator that is movable in a height direction of the storage unit and disperses powder in the liquid stored in the storage unit;
A drive unit that drives the stirring unit;
a control unit that controls a position of the stirring unit in the height direction based on a dispersion state of the powder in the liquid;
A stirring device comprising: the control unit acquires a drive parameter related to the drive of the drive unit as a parameter indicating the dispersion state;
The control unit controls a position of the stirring unit in the height direction in response to a change in the driving parameter.
The stirring device according to claim 1 . The control unit is
When the driving parameter becomes larger than a reference range in a state where the stirring unit is located at an initial position in the height direction, the stirring unit is moved from the initial position to an upper side in the height direction;
In a state in which the stirring unit has moved from the initial position to the upper side in the height direction, the stirring unit is moved to the lower side in the height direction based on a change over time in the drive parameter that has switched from an increase to a decrease;
stopping the movement of the stirring unit in the height direction based on the fact that the drive parameter falls within the reference range in a state in which the stirring unit is moving downward in the height direction;
The stirring device according to claim 2. the control unit stops the rotation of the stirring unit based on a change over time in the drive parameter switching from an increase to a decrease in a state in which the movement of the stirring unit in the height direction is stopped.
The stirring device according to claim 3. The driving parameter is a load current value of the driving unit or a torque value of the driving unit.
The stirring device according to any one of claims 2 to 4. The stirring device according to claim 1, further comprising a connection port that can be connected to a vacuum device. Storing a liquid in a storage portion;
dispersing powder in the liquid by driving an agitator in the liquid stored in the storage section;
Controlling a position of the agitator in a height direction of the storage unit based on a dispersion state of the powder in the liquid;
The stirring method comprising: