Combined weighing device

Abstract

To set a proper stabilization time without relying on experience and intuition.SOLUTION: A combination weighing device 1 comprises: a storage unit 22 that stores time-series weighing values sequentially acquired by a weighing hopper 6; a time measurement unit 24 that when the time-series metric values stored in the storage unit 22 converge within a region that can be considered stable, measures, as a stabilization time, an elapsed time from the timing corresponding to the supply of an article M to the weighing hopper 6 to the timing at which the time-series weighing values enter the region that can be considered stable; and a recommended stabilization time calculation unit 26 and an interface 30 that acquire a stabilization time by the time measurement unit 24 over a plurality of cycles, and can select a recommended stabilization time, which is a stabilization time that can maintain predetermined weighing accuracy, based on the standard deviation of the acquired stabilization times of the plurality of cycles.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] One aspect of the present invention relates to a combination weighing device.

Background Art

[0002] There is known a combination weighing device that supplies an article to a plurality of weighing hoppers for weighing, obtains combinations of the plurality of weighing hoppers based on the obtained plurality of weighing values, selects a combination close to a target weight value from the obtained combinations, and repeats a cycle of discharging the article from the plurality of weighing hoppers related to the selected combination. In such a combination weighing device, as one of the operation timings, a stabilization time until the weighing value stabilizes is set. Then, for example, from the timing when an article is supplied to the weighing hopper, the stabilization time until the weighing value stabilizes is measured, and when this stabilization time has elapsed, the weighing value of the weighing hopper is acquired. This stabilization time is usually set according to the capacity of the combination weighing device. Therefore, for example, in the combination weighing device described in Patent Document 1, a waveform of time-series weighing values sequentially acquired by the weighing hopper is acquired, and the stabilization time is found by displaying it on a measuring instrument or the like and setting it in the device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described combination weighing device, for example, depending on the type of the article, the supplied article may move like dancing in the weighing hopper. Therefore, the stabilization time is not always appropriate, and there is a possibility that the weighing value acquired after the elapse of the stabilization time does not match the true actual weight of the article. In this case, the stabilization time has to be adjusted, but in fact, such adjustment is still carried out relying on experience and intuition.

[0005] Therefore, one aspect of the present invention is to provide a combination weighing device capable of setting an appropriate stabilization time without relying on experience and intuition.

Means for Solving the Problem

[0006] A combination weighing device according to one aspect of the present invention supplies articles to a plurality of weighing hoppers for weighing, obtains combinations of the plurality of weighing hoppers based on the obtained plurality of weighing values, selects a combination close to a target weight value from the obtained combinations, and discharges articles from the plurality of weighing hoppers related to the selected combination. The combination weighing device repeats a cycle, and includes a storage unit that stores time-series weighing values sequentially acquired by the weighing hoppers, and when the time-series weighing values stored in the storage unit converge within a region where they can be regarded as stable, the elapsed time from the timing corresponding to the supply of the articles to the weighing hoppers to the timing when the time-series weighing values enter the region where they can be regarded as stable is measured as the stabilization time until the weighing values become stable. A time measurement unit, and a selection unit that can select a recommended stabilization time that is a stabilization time capable of maintaining a predetermined weighing accuracy based on the standard deviation of the stabilization times of the plurality of cycles acquired by the time measurement unit over a plurality of cycles.

[0007] In this combination weighing device, the varying stabilization time each time an article is put into the weighing hopper is acquired over a plurality of cycles, and a recommended stabilization time capable of maintaining a predetermined weighing accuracy can be selected based on the standard deviation obtained from the statistical data of the acquired stabilization times. Thereby, it becomes possible to set an appropriate stabilization time without relying on experience and intuition.

[0008] In the combination weighing device according to one aspect of the present invention, the time measurement unit may obtain convergence values of the time-series weighing values stored in the storage unit over a plurality of cycles, and obtain a region with a certain width based on the convergence values of each obtained cycle as a region where it can be regarded as stable. Thereby, it becomes possible to specifically obtain a region where it can be regarded as stable.

[0009] In the combination weighing device according to one aspect of the present invention, the time measurement unit may specify the timing at which the time series of measurement values stored in the storage unit enters a region where the time series of measurement values can be regarded as stable by tracing back the time for the time series of measurement values. Thereby, it becomes possible to specifically obtain the timing at which the time series of measurement values enters a region where the time series of measurement values can be regarded as stable.

[0010] In the combination weighing device according to one aspect of the present invention, the selection unit may have a display unit that displays a histogram of the stable times of a plurality of cycles and also displays the recommended stable time on the histogram. Thereby, it is possible to easily confirm the recommended stable time on the display unit.

[0011] In the combination weighing device according to one aspect of the present invention, the recommended stable time may be a time obtained by adding a time corresponding to twice the standard deviation to the average value of the stable times of the plurality of cycles acquired. In this case, it becomes possible to specifically set an appropriate stable time.

[0012] In the combination weighing device according to one aspect of the present invention, the timing corresponding to the supply of the article to the weighing hopper may relate to at least any one of the timing of closing the article discharge gate in the weighing hopper, the timing of opening the article discharge gate in the weighing hopper, and the timing of opening the article discharge gate in the supply hopper that supplies the article to the weighing hopper. In this case, as the starting point of the stable time, it is possible to adopt the timing related to any one of the timing of closing the article discharge gate of the weighing hopper, the timing of opening the article discharge gate of the weighing hopper, and the timing of opening the article discharge gate of the supply hopper.

Advantages of the Invention

[0013] According to one aspect of the present invention, it is possible to provide a combination weighing device capable of setting an appropriate stable time without relying on experience and intuition.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0016] FIG. 1 is a schematic configuration diagram of a combination weighing device 1 according to the present embodiment. As shown in FIG. 1, the combination weighing device 1 includes a feed chute 2, a distribution feeder 3, a plurality of radiation feeders 4, a plurality of pool hoppers (supply hoppers) 5, a plurality of weighing hoppers 6, a collecting chute 8, a timing hopper 9, a weighing unit 11, a control unit 20, and an interface 30. The combination weighing device 1 supplies the article M to the plurality of weighing hoppers 6 for weighing, obtains combinations of the plurality of weighing hoppers 6 based on the weighed values of the articles in the obtained plurality of weighing hoppers 6, selects a combination of the article M close to the target weight value from the obtained combinations, and repeats a cycle of discharging the article from the plurality of weighing hoppers 6 related to the selected combination.

[0017] The combination weighing device 1 weighs the article M supplied by the conveyor 50 so as to have a target weight value and supplies it to the bag-making and packaging machine 60. The bag-making and packaging machine 60 forms a film into a bag of a predetermined capacity and packs the article M discharged from the combination weighing device 1 into the bag. The conveyor 50 is an external device that supplies the article M to the combination weighing device 1. The article M is an article having a variation in single mass, such as agricultural products, fishery products, processed foods, etc.

[0018] The input chute 2 is disposed below the conveying end 50a of the conveying conveyor 50. The input chute 2 receives the article M that has fallen from the conveying end 50a of the conveying conveyor 50 and discharges it downward. The dispersion feeder 3 conveys the article M supplied from above toward the periphery. The dispersion feeder 3 is disposed below the input chute 2. The dispersion feeder 3 has a conical conveying surface 3a that widens toward the periphery with a high central portion and a low periphery. The dispersion feeder 3 conveys the article M on the conveying surface 3a toward the periphery by vibrating the electromagnetic vibrator. For example, the dispersion feeder 3 disperses the article M discharged from the input chute 2 to the top of the conveying surface 3a toward the outer edge of the conveying surface 3a by vibrating the conveying surface 3a.

[0019] The plurality of radial feeders 4 further convey the article M conveyed from the dispersion feeder 3 in the radial direction. The plurality of radial feeders 4 are arranged radially along the outer edge of the conveying surface 3a of the dispersion feeder 3. The radial feeder 4 has a trough 4a that extends outward from below the outer edge of the conveying surface 3a. The radial feeder 4 conveys the article M by vibrating the electromagnetic vibrator. For example, the radial feeder 4 conveys the article M discharged from the outer edge of the conveying surface 3a toward the tip of the trough 4a by vibrating the trough 4a.

[0020] The plurality of pool hoppers 5 are arranged so as to surround the vertical center line CL. Each pool hopper 5 is disposed below the tip of the trough 4a of each radial feeder 4. Each pool hopper 5 has an openable gate (article discharge gate) 5a. The gate 5a is located at the bottom of the pool hopper 5. Each pool hopper 5 temporarily stores the article M discharged from the tip of the corresponding trough 4a by closing the gate 5a. Each pool hopper 5 discharges the temporarily stored article M downward by opening the gate 5a. That is, the pool hopper 5 stores the supplied article M in a temporarily closed state of the gate 5a, and then supplies the article M to the lower weighing hopper 6 by opening the gate 5a (in an open state).

[0021] A plurality of weighing hoppers 6 are arranged so as to surround the center line CL. Each weighing hopper 6 is arranged below the gate 5a of each pool hopper 5. Each weighing hopper 6 has a main body 61 for storing the article M and a gate (article discharge gate) 62 that can be opened and closed at its bottom. The gate 62 is provided on the main body 61. The gate 62 is located at the bottom of the weighing hopper 6. Each weighing hopper 6 temporarily stores the article M discharged from the corresponding pool hopper 5 into the main body 61 by closing the gate 62. Each weighing hopper 6 discharges the article M temporarily stored in the main body 61 downward by opening the gate 62. That is, the weighing hopper 6 stores the supplied article M in a temporarily closed state of the gate 62, and then discharges the article M downward with the gate 62 in an open state.

[0022] The collecting chute 8 collects the articles M discharged from each weighing hopper 6 at the discharge port 8a. The discharge port 8a is located on the lower center line CL with respect to the plurality of weighing hoppers 6. The collecting chute 8 has an upper chute portion 81 and a lower chute portion 82. The upper chute portion 81 receives the articles M discharged from each weighing hopper 6 and slides the articles M toward the discharge port 8a side (that is, the center line CL side and the lower side). The lower chute portion 82 is a conical frustum-shaped cylinder that tapers downward and has an upper opening 82a and a lower opening 82b. The lower chute portion 82 discharges the article M downward from the discharge port 8a with the lower opening 82b as the discharge port 8a.

[0023] The timing hopper 9 is arranged below the discharge port 8a. The timing hopper 9 has an openable and closable gate 9a. The gate 9a is located at the bottom of the timing hopper 9. The timing hopper 9 temporarily stores the article M discharged from the collecting chute 8 by closing the gate 9a. The timing hopper 9 discharges the article M temporarily stored into the bag-making and packaging machine 60 by opening the gate 9a.

[0024] The weighing unit 11 is disposed within a case 13 supported by a frame 12. The weighing unit 11 has a plurality of load cells 11a. Each load cell 11a supports a corresponding weighing hopper 6. When an article M is temporarily stored in each weighing hopper 6, the weighing unit 11 weighs (acquires) the weight value of each weighing hopper (the weighing value corresponding to the mass of the article M). In the present embodiment, the weighing unit 11 performs real-time weighing (sequentially weighs) in at least one of the plurality of weighing hoppers 6 to acquire time-series weighing values. Further, corresponding to each weighing unit 11, a link mechanism (not shown) that selectively opens and closes each gate 5a, 62 of the pool hopper 5 and the weighing hopper 6, and a drive unit (not shown) that selectively operates the link mechanism, are provided.

[0025] The control unit 20 is disposed within the case 13. The control unit 20 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The control unit 20 controls the operations of each part of the combination weighing device 1, such as the conveying operations of the distributed feeder 3 and the radiation feeder 4, the opening and closing operations of the gates 5a of each pool hopper 5, the opening and closing operations of the gates 62 of each weighing hopper 6, and the opening and closing operation of the gate 9a of the timing hopper 9. The control unit 20 is communicably connected to the bag-making and packaging machine 60.

[0026] The control unit 20 stores the weighing value weighed by the weighing unit 11 in association with the weighing hopper 6 that stores the article M corresponding to the weighing value. The control unit 20 selects a combination of the articles M such that the total value becomes the target weight value from among the plurality of weighing values of the articles M weighed by the weighing unit 11 and associated with each weighing hopper 6. More specifically, the control unit 20 combines the weighing values of the respective articles M output by each weighing unit 11, and selects a combination of the articles M such that the combined total value is close to the target weight value and falls within a predetermined range. That is, the control unit 20 calculates a combination of the articles M that is equal to or close to the preset target weight value based on the weight values of the articles M in the plurality of weighing hoppers 6 acquired by the weighing unit 11. Then, the control unit 20 discharges the article M from the weighing hopper 6 of the article M related to the calculated combination.

[0027] Interface 30 is a device that receives information input from a user such as an operator. The information received via interface 30 is transmitted to control unit 20. In the present embodiment, interface 30 has a touch panel display (display unit) 30t constituted by, for example, a liquid crystal display or the like. Interface 30 may have a keyboard, a mouse, a numeric keypad, a microphone, or the like. Interface 30 may have a speaker or the like that outputs sound. Interface 30 enables selection of a stabilization time (described in detail later) via touch panel display 30t.

[0028] The charging chute 2, the dispersion feeder 3, the plurality of radiation feeders 4, the plurality of pool hoppers 5, and the plurality of weighing hoppers 6 are directly or indirectly supported by the case 13. The collecting chute 8 and the timing hopper 9 are directly or indirectly supported by the frame 12.

[0029] Next, the control unit 20 will be described in detail.

[0030] FIG. 2 is a diagram showing a functional configuration of the control unit 20. As shown in FIG. 2, the control unit 20 includes a storage unit 22, a time measurement unit 24, and a recommended stabilization time calculation unit 26. The control unit 20 has the storage unit 22, the time measurement unit 24, and the recommended stabilization time calculation unit 26 as conceptual parts for executing various control processes. Such conceptual parts are configured as software in which, for example, a program stored in a ROM is loaded onto a RAM and executed by a CPU.

[0031] The storage unit 22 stores information related to the operation of the combination weighing device 1. The storage unit 22 stores time-series weighing values that are real-time weighed by the weighing unit 11 in the weighing hopper 6. The time-series weighing values are data of the weighing values weighed over time by the weighing unit 11 during a period (for example, 3 seconds) including at least one cycle that the combination weighing device 1 repeats. The time-series weighing values are data represented in a waveform, for example, on a graph with time and the weighing value as the horizontal and vertical axes. The storage unit 22 stores and accumulates time-series weighing values for different periods for one or a plurality of weighing hoppers 6. The storage unit 22 stores and accumulates a plurality of the above-described stabilization times.

[0032] The time measurement unit 24 starts timing from the point in time when the weighing value becomes unstable due to mechanical vibrations accompanying the opening and closing of the gates of the weighing hopper 6 or the pool hopper 5. The timing of starting the timing in this case is, for example, the timing at which the control unit 20 outputs a drive signal to the gates 5a, 62 of the pool hopper 5 and the weighing hopper 6. The weighing values of the weighing hopper 6 are sequentially input from that timing and stored in the storage unit 22. The time-series weighing values stored in the storage unit 22 converge to a variation width that can be regarded as being within the stable region as time passes. The stable region in this case is a region with a preset fixed width. The time measurement unit 24 obtains the convergence values of the time-series weighing values stored in the storage unit 22 over a plurality of cycles, and can obtain a region with a fixed width based on the convergence values of each obtained cycle as the stable region. The time measurement unit 24 measures the elapsed time from the timing corresponding to the supply of the article M to the weighing hopper 6 until the timing when the time-series weighing values enter the stable region when the time-series weighing values stored in the storage unit 22 converge within the stable region (a region that can be regarded as being stable) as the stabilization time until the weighing value becomes stable.

[0033] The convergence value of each cycle depends on the supply amount of the article M supplied to the weighing hopper 6 in each cycle. In addition, in the present embodiment, the fluctuation range that can be regarded as being within the stable region includes not only the fluctuation range when it is completely within the stable region, but also, for example, the fluctuation range when it instantaneously goes outside the stable region but is otherwise within the stable region. This fluctuation range is a predetermined upper limit value and a lower limit value based on the convergence value. In the present embodiment, the timing according to the supply of the article M to the weighing hopper 6 relates to the timing of opening the gate 5a in the pool hopper 5 that supplies the article M to the weighing hopper 6. Note that the timing according to the supply of the article M to the weighing hopper 6 is not particularly limited, and may relate to the timing of closing the gate 62 in the weighing hopper 6, or may relate to the timing of opening the gate 62 in the weighing hopper 6.

[0034] The time measurement unit 24 identifies the timing at which the time-series weighing values stored in the storage unit 22 enter the stable region by tracing back the time for the time-series weighing values. For example, the weighing values that converge to a fluctuation range that can be regarded as being within the stable region will conversely have an increasing fluctuation as the time is traced back. Therefore, for the weighing values that converge to a fluctuation range that can be regarded as being within the stable region, when the result of tracing back the time intersects the upper limit or the lower limit of the stable region, the time measurement unit 24 identifies that point as the timing of entering the stable region.

[0035] The recommended stabilization time calculation unit 26 acquires the stabilization time by the time measurement unit 24 over a plurality of cycles, and stores and accumulates the stabilization time in the storage unit 22 as statistical data. The recommended stabilization time calculation unit 26 calculates the standard deviation of the stabilization times of the plurality of cycles stored in the storage unit 22. The recommended stabilization time calculation unit 26 calculates a recommended stabilization time, which is the stabilization time that can maintain a predetermined weighing accuracy, based on the calculated standard deviation. The recommended stabilization time is the time obtained by adding a time equivalent to twice the standard deviation to the average value of the stabilization times of the plurality of cycles obtained.

[0036] The recommended stabilization time calculation unit 26 displays a histogram of the stabilization times of a plurality of cycles on the touch panel display 30t of the interface 30. The recommended stabilization time calculation unit 26 also displays the recommended stabilization time on the histogram of the touch panel display 30t. Thereby, the interface 30 can select the recommended stabilization time via the touch panel display 30t. The recommended stabilization time calculation unit 26 and the interface 30 constitute a selection unit.

[0037] Next, an example of the process when the control unit 20 causes the touch panel display 30t to display the recommended stabilization time in a selectable manner will be described in detail with reference to the flowchart of FIG. 3.

[0038] First, for example, any one of a plurality of weighing hoppers 6 is selected as the weighing hopper 6 to be the subject of real-time weighing (step S1). The selected weighing hopper 6 is weighed in real time, and time-series weighing values are acquired (step S2). For the acquired time-series weighing values, the stabilization time is measured by the time measurement unit 24, and the measured stabilization time is accumulated in the storage unit 22 (step S3).

[0039] It is determined whether or not the number of accumulated stabilization times in the storage unit 22 is a certain value or more (step S4). If NO in step S4 above, the process returns to the process of step S1. If YES in step S4 above, the recommended stabilization time calculation unit 26 calculates the average value and the standard deviation of the stabilization times (step S5). The recommended stabilization time calculation unit 26 calculates the recommended stabilization time. Then, the histogram of the stabilization times and the recommended stabilization time are displayed on the touch panel display 30t (step S7).

[0040] FIG. 4 is a graph showing an example of the stabilization time S0. In the example of FIG. 4, an example in which the time-series measured value K is measured in real time is shown. In the time-series measured value K, in response to the supply of the article M to the weighing hopper 6 (the timing t0 when the gate 5a of the pool hopper 5 changes from the closed state to the open state), it rapidly increases and reaches a peak, and then fluctuates in a wavy manner while the fluctuation width decreases, converging to a certain convergence value. The timing of opening the gate 5a can be obtained based on the drive signal for the gate 5a. On the time-series measured value K, a stable region R0 with a certain width is set based on the convergence value. The time-series measured value K converges to a fluctuation width that can be regarded as being within the stable region R0. In such a time-series measured value K, by tracing the waveform backward in time (from right to left in the figure), the timing t1 when the value enters the stable region R0 is specified. As a result, the period from the timing t0 to the timing t1 is obtained as the stabilization time RT.

[0041] FIG. 5 is a diagram showing a display example of the touch panel display 30t. In the example of FIG. 5, a histogram with the vertical axis being the frequency and the horizontal axis being the stabilization time is shown. The recommended stabilization time is also displayed on the histogram. By displaying the statistical data of the accumulated stabilization time RT as a histogram, a reference for setting and adjusting the stabilization time RT can be shown. Also, an appropriate value of the stabilization time is presented as the recommended stabilization time. For example, in such a touch panel display 30t, the recommended stabilization time value may be selectable by touch-selecting the displayed recommended stabilization time value or inputting the displayed recommended stabilization time value on another screen.

[0042] As described above, in the combination weighing device 1, each time an article M is put into the weighing hopper 6, the varying stabilization time RT is obtained over a plurality of cycles, and based on the standard deviation obtained from the statistical data of the obtained stabilization time RT, a recommended stabilization time that can maintain a predetermined weighing accuracy can be selected. Thereby, it becomes possible to set an appropriate stabilization time RT without relying on experience and intuition.

[0043] In the combination weighing device 1, the time measurement unit 24 obtains the convergence values of the time-series weighing values K stored in the storage unit 22 over a plurality of cycles, and obtains a region with a certain width based on the convergence value of each obtained cycle as the stable region R0. As a result, it becomes possible to specifically obtain the stable region R0. Incidentally, the stable region R0 may be a fixed value set by, for example, a remote controller.

[0044] In the combination weighing device 1, the time measurement unit 24 specifies the timing at which the time-series weighing value K enters the stable region R0 by tracing back the time for the time-series weighing value K stored in the storage unit 22. As a result, it becomes possible to specifically obtain the timing at which the time-series weighing value K enters the stable region R0.

[0045] In the combination weighing device 1, the interface 30 has a touch panel display 30t that displays the histogram of the stable times RT of a plurality of cycles and also displays the recommended stable time on the histogram. As a result, the recommended stable time can be easily confirmed on the touch panel display 30t.

[0046] In the combination weighing device 1, the recommended stable time is the time obtained by adding a time equivalent to twice the standard deviation to the average value of the stable times RT of the plurality of acquired cycles. In this case, it becomes possible to specifically set an appropriate stable time RT.

[0047] In the combination weighing device 1, the timing t0 for supplying the article M to the weighing hopper 6 (corresponding to the supply of the article M to the weighing hopper 6) is related to the timing t0 for opening the gate 5a in the pool hopper 5 that supplies the article M to the weighing hopper 6. In this case, the timing t0 for opening the gate 5a of the pool hopper 5 can be adopted as the starting point of the stable time RT.

[0048] In the combination weighing device 1, the time until the measured value converges within the stable region R0 is measured starting from the timing when the measured value becomes unstable. For example, when the gate 62 of the weighing hopper 6 closes to receive the article M, or when the gate 5a of the pool hopper 5 opens and the article M is supplied to the weighing hopper 6, the measured value becomes unstable. Therefore, it is preferable to start the measurement from that timing. This is because these timings can be obtained from the output timings of the drive signals for opening and closing the gates 62 and 5a. However, the timing for starting the timing is not limited to this. For example, when a discharge request signal is received from an external device such as a packaging machine, if the article M is to be supplied to the weighing hopper 6 after a certain time from that point, the timing is started from the point when the discharge request signal is received, and the stable time until the unstable measured value becomes stable is obtained by subtracting the above-mentioned certain time from the measurement time at that time.

[0049] As described above, one aspect of the present invention has been described, but one aspect of the present invention is not limited to the above-described embodiment.

[0050] In the above-described embodiment, the plurality of pool hoppers 5 and weighing hoppers 6 are arranged in a ring shape, but the present invention is not limited to this, and they may be arranged in a matrix shape. The above-described embodiment and the above-described modification example may include a plurality of booster hoppers. In the above-described embodiment and the above-described modification example, a part of the functions of the control unit 20 may be executed by another control unit, or may be executed by a server capable of communicating with the combination weighing device 1.

[0051] In the above-described embodiment and the above-described modification example, when calculating the recommended stable time, the recommended stable time may be automatically selected as the stable time RT. In the above-described embodiment and the above-described modification example, by collecting the stable time RT for each article M, it may be possible to select the recommended stable time according to the article M. In the above-described embodiment and the above-described modification example, by collecting the stable time RT in association with the actual operating conditions (operation rate and defect rate), it may be possible to select a better recommended stable time.

Explanation of Reference Numerals

[0052] 1...Combination weighing device, 3...Dispersion feeder, 4...Radiation feeder, 5...Pool hopper (supply hopper), 5a...Gate (article discharge gate), 6...Weighing hopper, 11...Weighing unit, 20...Control unit, 22...Memory unit, 24...Time measurement unit, 26...Recommended stabilization time calculation unit (selection unit), 28...Gate opening / closing time adjustment unit, 30...Interface (selection unit), 62...Gate (article discharge gate), M...Article.

Claims

1. A combination weighing device that supplies an article to a plurality of weighing hoppers for weighing, determines combinations of the plurality of weighing hoppers based on the obtained plurality of weighing values, selects a combination close to a target weight value from the determined combinations, and repeats a cycle of discharging the article from the plurality of weighing hoppers related to the selected combination, comprising: a storage unit that stores time-series weighing values sequentially acquired by the weighing hoppers; a time measurement unit that measures, as a stabilization time until the weighing value of the time series enters a region where the time-series weighing values stored in the storage unit can be considered to have stabilized, the elapsed time from the timing corresponding to the supply of the article to the weighing hoppers until the weighing value of the time series enters the region where it can be considered to have stabilized when converging within a region where the time-series weighing values stored in the storage unit can be considered to have stabilized; a selection unit that can select a recommended stabilization time, which is the stabilization time capable of maintaining a predetermined weighing accuracy, based on the standard deviation of the stabilization times of the plurality of cycles acquired by the time measurement unit over the plurality of cycles. A combination weighing device comprising:

2. The combination weighing device according to claim 1, wherein the time measurement unit obtains convergence values of the time-series weighing values stored in the storage unit over a plurality of cycles, and determines a region with a certain width based on the obtained convergence values of each cycle as the region where the weighing values can be considered to have stabilized.

3. The combination weighing device according to claim 1 or 2, wherein the time measurement unit specifies the timing when the time-series weighing values enter the region where the weighing values can be considered to have stabilized by tracing back the time-series weighing values stored in the storage unit.

4. The combination weighing device according to any one of claims 1 to 3, wherein the selection unit has a display unit that displays a histogram of the stabilization times of the plurality of cycles and also displays the recommended stabilization time on the histogram.

5. The combination weighing device according to any one of claims 1 to 4, wherein the recommended stabilization time is a time obtained by adding a time equivalent to twice the standard deviation to the average value of the stabilization times of the plurality of cycles acquired.

6. The timing according to the supply of the article to the metering hopper relates to at least any one of the timing of closing the article discharge gate in the metering hopper, the timing of opening the article discharge gate in the metering hopper, and the timing of opening the article discharge gate in the supply hopper that supplies the article to the metering hopper. The combined weighing device according to any one of claims 1 to 5.

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