Combination weighing apparatus

Abstract

To reduce unnecessary discharge of articles caused by over-scale as much as possible.SOLUTION: A combination weighing apparatus (1) according to an embodiment includes: weighing devices (a-c) each having hoppers (6) for storing articles, the weighing devices (a-c) being configured to select a combination of articles having a total weight close to a target weight by combining weights of the articles stored in the plurality of hoppers (6) and to discharge the selected combination of articles; a control unit (11) for sequentially executing respective combination selections performed by the weighing devices (a-c); and a correction unit (12) for correcting the target weight of a weighing device that performs a subsequent combination selection, using a deviation between the total weight of the combination of articles selected by a weighing device that has previously performed a combination selection and the target weight used for the selection. The control unit (11) is configured such that, even when an article having a weight exceeding the sum of the corrected target weight after correction by the correction unit (12) and the upper limit value is stored in any of hoppers (6a-6c) of the plurality of weighing devices (a-c), if the weight of the article does not exceed the sum of a target weight before correction by the correction unit (12) and the upper limit value, the article stored in the hopper is not forcibly discharged and is used for a next combination selection.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a combination weighing device. [Background technology]

[0002] BACKGROUND ART Conventionally, a combination weighing device has been known that has a plurality of weighing devices that combine and weigh different types of articles (see Patent Document 1).

[0003] For example, when a combination weighing device combines and weighs different types of products using three weighing devices to form a mixed product, it corrects the weighing target value of the second weighing device using the deviation between the weight of the combined and weighed items on the first weighing device and the weighing target value at that time, and then combines and weighs the next type of item.If the above-mentioned deviation also occurs on the second weighing device, it corrects the weighing target value of the third weighing device using that deviation, thereby performing ``sequential correction.''

[0004] For example, when measuring a three-kind mix of paprika, the setting values ​​of each measuring device are assumed to be as follows:

[0005] First weighing device: Target weighing value 30g, upper limit +13g, lower limit -20g Second weighing device: Target weighing value 30g, upper limit +13g, lower limit -20g Third weighing device: Target weighing value 34g, upper limit +15g, no lower limit In such a case, for example, if the combined weight of the first weighing device is 35g, the weighing target value of the second weighing device is corrected to 30g-(35g-30g)=25g, and the second weighing device performs combined weighing at this weighing target value of 25 (the upper limit value +13g and the lower limit value -20g remain unchanged).

[0006] If the combined weight of the second weighing device at that time is 35 g, the target weight value of the third weighing device is corrected to 34 g - (35 g - 25 g) = 24 g.

[0007] In this way, when combination weighing is performed using a plurality of weighing devices, the target weighing values ​​of the second weighing device and the third weighing device are corrected sequentially.

[0008] On the other hand, when the weight of the items stored in any one weighing hopper becomes equal to or greater than the weighing target value + upper limit value, each weighing device determines that the weighing hopper is an over-scale hopper that can no longer be selected for combination, and forcibly discharges the items stored in that weighing hopper.

[0009] Therefore, for example, when the weighing target value of the third weighing device is corrected to 24 g, if the weight of the items stored in any one of the weighing hoppers of the third weighing device becomes equal to or greater than the weighing target value + upper limit value = 24 g + 15 g = 39 g, that weighing hopper will be determined to be overscale and will be forcibly ejected. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Special Publication No. 5-6313 Summary of the Invention [Problem to be solved by the invention]

[0011] However, in the case of a conventional combination weighing device, in the above-mentioned case, if the combined weight of the first weighing device and the second weighing device is both 30 g, the weighing target value of the third weighing device is 34 g (upper limit 15 g), so a weighing hopper containing items weighing 39 g will not be overscaled.

[0012] In this way, when the product may or may not be overscale, if the products stored in the weighing hopper are discharged based on the initial determination that the product is overscale, there is a problem that the products will be discharged unnecessarily in the next cycle, even though there is a possibility that the product will not be overscale.

[0013] Therefore, the present invention has been made in consideration of the above-mentioned problems, and aims to provide a combination weighing device that can improve operating rates by suppressing the wasteful discharge of items that have become overscaled due to changes in the weighing target value. [Means for solving the problem]

[0014] In one embodiment, the combination weighing device has a plurality of weighing devices that combine the weights of items stored in a plurality of hoppers and select and discharge a combination of items whose weight is closest to a target weighing value, and is equipped with a control unit that causes each of the weighing devices to execute the respective combination selections in sequence, and a correction unit that corrects the target weighing value of the weighing device that subsequently executes the combination selection using the deviation between the combined weight of the items selected by the weighing device that previously executed the combination selection and the target weighing value used for the selection, and the control unit is configured to use the hopper that stores an item whose weight exceeds the sum of the target weighing value and an upper limit value after correction by the correction unit, rather than forcibly ejecting the item stored in that hopper, if the weight of the item does not exceed the sum of the target weighing value and the upper limit value before correction by the correction unit.

[0015] In addition, in one embodiment of the combination weighing device, if the weighing target value corrected by the correction unit is smaller than the weighing target value before correction, the control unit uses the weight of the items stored in the hopper to select the next combination.

[0016] For example, if the weighing target value corrected by the correction unit is smaller than the weighing target value before correction, the weight of the items stored in the hopper will not exceed the sum of the weighing target value before correction and the upper limit value, and therefore the weight of the items stored in the hopper will be used to select the next combination.

[0017] In addition, in one embodiment of the combination weighing device, the control unit forcibly discharges items stored in the hopper if the weighing target value corrected by the correction unit is greater than the weighing target value before correction.

[0018] For example, if the corrected weight target value is greater than the uncorrected weight target value, the weight of the items stored in the hopper will exceed the sum of the uncorrected weight target value and the upper limit, and the items stored in the hopper will be forcibly discharged. This forced discharge empties the hopper that has been overfilled with items, and the weight of the newly supplied items can be used to select a new combination. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a combination weighing device that can improve the operating rate by suppressing the wasteful discharge of over-scaled articles due to a change in the weighing target value. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram illustrating an example of the overall configuration of a combination weighing device 1 according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of how the dispersing table 2 of the combination weighing device 1 according to one embodiment is divided. DETAILED DESCRIPTION OF THE INVENTION

[0021] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description of the drawings, identical or similar parts are designated by identical or similar reference numerals. However, it should be noted that the drawings are schematic, and the dimensional ratios and the like may differ from those of the actual parts. Therefore, specific dimensions and the like should be determined with reference to the following description. Furthermore, parts in the drawings may have different dimensional relationships and ratios. In this specification and the drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant description, and elements not directly related to the present invention are not shown.

[0022] (First embodiment) A combination weighing device 1 according to a first embodiment of the present invention will now be described with reference to Figures 1 and 2. Figure 1 is a diagram illustrating an example of the overall configuration of the combination weighing device 1 according to the first embodiment of the present invention, and Figure 2 is a diagram showing an example in which the dispersion table 2 of the combination weighing device 1 according to this embodiment is divided into, for example, three parts. However, the number of divisions is not limited to three.

[0023] The combination weighing device 1 of this embodiment has a well-known configuration comprising a dispersion table 2 located at the top center, a plurality of radial feeders 3 arranged radially around it, a plurality of pool hoppers 4 located at the discharge outlets of each radial feeder 3, a plurality of weighing hoppers 6 located correspondingly below them, and a collection chute 9 located below the weighing hoppers 6. However, this combination device 1 is further virtually divided into a plurality of groups a to c, and weighing devices a to c are configured to perform combination weighing for each of the divided groups a to c.

[0024] For example, as shown in Figure 2, when the dispersion table 2 is divided into three groups a to c, weighing devices a to c are virtually configured for each of groups a to c, such that a plurality of radial feeders 3a corresponding to a first dispersion table 2a, an equal number of pool hoppers 4a, and an equal number of weighing hoppers 6a become weighing devices a belonging to one group a, and a plurality of radial feeders 3b corresponding to an adjacent second dispersion table 2b, an equal number of pool hoppers 4b, and an equal number of weighing hoppers 6b become weighing devices b belonging to one group b.

[0025] First, weighing device a performs combination selection, then weighing device b performs combination selection, and finally weighing device c performs combination selection, and the articles are simultaneously discharged from the weighing hoppers 6 of the respective weighing devices a to c, thereby mixing the articles in the collecting chute 9. Therefore, different types of articles are supplied from the respective supply devices 10 to the dispersion tables 2a to 2c of the respective weighing devices a to c.

[0026] However, the present invention is not limited to this type. For example, the present invention can be applied to a type in which three weighing devices a to c are arranged in parallel along a bucket conveyor, and different types of items are combined and weighed by each of the weighing devices a to c and sequentially discharged into the same bucket, thereby forming a mixed product in the bucket.

[0027] Furthermore, in this embodiment, the combination weighing device 1 having three weighing devices a to c has been described as an example, but the present invention is also applicable to cases having any number of weighing devices a to n.

[0028] In this embodiment, each of the three weighing devices a to c is supplied with articles that are relatively heavy and have varying unit weights, such as peppers of different colors, which may or may not be over-scaled when two or three are placed in the weighing hopper 6. Of course, this can also be applied to articles other than peppers.

[0029] As shown in FIG. 1, the combination weighing device 1 of this embodiment has a dispersion table 2 divided into three parts in a plan view, radial feeders 3a to 3c arranged corresponding to the dispersion table 2, pool hoppers 4a to 4c, weighing hoppers 6a to 6c, a weight detector 7, a collection chute 9, a control unit 11, and a correction unit 12.

[0030] The dispersion table 2 is made up of a conical vibration feeder and is placed at the center upper part of the combination weighing device 1. As shown in Fig. 2, the dispersion table 2 is separated into a first dispersion table 2a, a second dispersion table 2b, and a third dispersion table 2c by a partition plate 210, and the vibration mechanism is also separated into three, each of which is configured to vibrate independently.

[0031] The first dispersion table 2a belongs to the weighing device a, the second dispersion table 2b belongs to the weighing device b, and the third dispersion table 2c belongs to the weighing device c.

[0032] Each of the radial feeders 3a-3c individually supplies the articles conveyed from the dispersing tables 2a-2c to each of the downstream pool hoppers 4a-4c. Although not shown, the trough side walls of the radial feeders 3a-3c located at the boundaries of the weighing devices a-c are provided with partition walls to prevent adjacent articles from mixing. Each of the pool hoppers 4a-4c is also provided with a gate 5 that can be opened and closed, and is controlled so that articles are supplied from the radial feeders 3a-3c when the gate 5 is closed.

[0033] The multiple radial feeders 3a belonging to weighing device a feed the articles transported from the first dispersion table 2a into the multiple pool hoppers 4a arranged in the lower tier. Similarly, the multiple radial feeders 3b belonging to weighing device b feed the articles transported from the second dispersion table 2b into the multiple pool hoppers 4b, and the multiple radial feeders 3c belonging to weighing device c feed the articles transported from the third dispersion table 2c into the multiple pool hoppers 4c. As mentioned above, the multiple pool hoppers 4a arranged to correspond to the multiple radial feeders 3a and the same number of weighing hoppers 6a arranged below them belong to weighing device a, the multiple pool hoppers 4b arranged to correspond to the multiple radial feeders 3b and the same number of weighing hoppers 6b arranged below them belong to weighing device b, and similarly, the multiple pool hoppers 4c arranged to correspond to the multiple radial feeders 3c and the same number of weighing hoppers 6c arranged below them belong to weighing device c.

[0034] Each weighing hopper 6a to 6c stores the articles discharged from each pool hopper 4a to 4c. Each weighing hopper 6a to 6c is provided with a discharge gate 8, and when a combination is selected, the discharge gate 8 opens and discharges the articles into a collecting chute 9.

[0035] The weight detector 7 is attached so as to support each of the weighing hoppers 6a to 6c, and detects the weight of the articles contained in each of the weighing hoppers 6a to 6c.

[0036] The collecting chute 9 is funnel-shaped, receives articles discharged from the weighing hoppers 6a to 6c from an upper opening, and discharges them from a lower discharge opening.

[0037] The control unit 11 sequentially selects a combination for each weighing device a-c based on the weighing target value, upper limit value, and lower limit value set for each weighing device, selecting the combination closest to the weighing target value within the upper and lower limit range. Once combination selection for all weighing devices a-c is complete, the control unit 11 simultaneously discharges articles from the selected weighing hoppers of each weighing device a-c. Furthermore, if the control unit 11 finds an over-scale weighing hopper in any of the weighing devices a-c, it does not select a combination for the weighing device to which that weighing hopper belongs, and instead forcibly discharges articles from the over-scale weighing hopper. In this case, the discharge of articles from other weighing devices is also prohibited. If a sorting hopper is installed below the collecting chute 9, the over-scale discharged articles are discharged outside the system by the sorting hopper. If not, they are sorted on the final line after packaging.

[0038] The correction unit 12 corrects the weighing target value of the weighing device that will subsequently select a combination of items, using the deviation between the combined weight of the items selected by the weighing device that previously selected a combination of items and the weighing target value used for such combination selection.

[0039] For example, when three different colored paprikas are combined and weighed to produce a mixed product, the setting values ​​of the weighing devices a to c are assumed to be set as follows.

[0040] First weighing device a: Target weighing value 30g, upper limit +13g, lower limit -20g Second weighing device b: Target weighing value 30g, upper limit +13g, lower limit -20g Third weighing device c: Target weighing value 35g, upper limit +15g, no lower limit First, when the combined weight of the items selected by the first weighing device a is 35 g, the correction unit 12 corrects the initial weighing target value of 30 g of the second weighing device b, which will subsequently select a combination of items, by the deviation of 5 g (35 g - 30 g) between the weighing target value of 30 g used in the selection and the combined weight of the items, i.e., the correction unit 12 corrects the weighing target value of the second weighing device b to 25 g.

[0041] Next, if the weight of the combination of items selected by the second weighing device b is 28 g, the correction unit 12 corrects the initial weighing target value of 35 g for the third weighing device c, which will subsequently select a combination of items, by the deviation of 3 g (28 g - 25 g) between the weighing target value of 25 g used in the selection and the combined weight of 28 g. In other words, the weighing target value of the third weighing device c is set to 32 g.

[0042] Finally, when the combined weight of the items selected by the third weighing device c is 33 g, these items are discharged all at once into the collecting chute 9 and mixed to form a mixed product. In this case, the weight of the mixed product is 96 g (= 35 g + 28 g + 33 g) compared to the initial weighing target value of 95 g (= 30 g + 30 g + 35 g).

[0043] In addition, even if an item whose weight exceeds the sum of the weighing target value and upper limit value after correction by the correction unit 12 is stored in any of the weighing hoppers 6a to 6c of the multiple weighing devices a to c, if the weight of the item does not exceed the sum of the weighing target value and upper limit value of the weighing device a to c to which the weighing hopper 6a to 6c belongs before correction by the correction unit 12, the control unit 11 will not forcibly eject the item stored in the weighing hopper, but will use it to select the next combination of items.

[0044] For example, in the above case, even if the weighing hopper 6c of the third weighing device c contains an item (e.g., 48g) whose weight exceeds the sum (47g) of the weighing target value (32g) and the upper limit value (15g) after correction by the correction unit 12, if the weight of the item (48g) does not exceed the sum (50g) of the weighing target value (35g) and the upper limit value (15g) of the third weighing device c before correction by the correction unit 12, the control unit 11 will not forcibly eject the item stored in the weighing hopper, but will use it to select the next combination of items.

[0045] In contrast, for example, if the weighing hopper 6c of the third weighing device c stores an item weighing more than the sum (47g) of the weighing target value (32g) after correction by the correction unit 12 and the upper limit value (15g), such as a 51g item, the weight of such item (51g) exceeds the sum (50g) of the weighing target value (35g) and the upper limit value (15g) of the third weighing device c before correction by the correction unit 12.In this case, the control unit 11 will not perform combination selection by the third weighing device c, but will forcibly discharge the items stored in the weighing hopper 6c, and then combine the weights of the items in the remaining weighing hoppers 6c of the third weighing device c to select a combination whose combined weight is closest to the weighing target value within the weighing target value + upper limit value, and if this combination selection is successful, the control unit 11 will simultaneously discharge the combined and selected items from each of the weighing devices a to c.

[0046] According to this embodiment, in the case of over-scale caused by a change in the measurement target value, unnecessary discharge of items is prevented, thereby reducing the number of items discharged and improving yield.

[0047] Although the present invention has been described in detail using the above-described embodiments, it is clear to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented in modified and altered forms without departing from the spirit and scope of the present invention as defined by the claims. Therefore, the description in this specification is intended to be illustrative and explanatory and does not have any limiting meaning on the present invention. [Explanation of symbols]

[0048] 1...Combined weighing device 2, 2a, 2b, 2c... Distributed table 210...Partition board 3a, 3b, 3c...radiant feeder 4a, 4b, 4c...Pool hopper 5...Gate 6a, 6b, 6c...Weighing hopper 7...Weight detector 8...Discharge gate 9...Group shoot 11...Control unit 12...Correction section

Claims

1. A combination weighing device having a plurality of weighing devices that combines the weights of items stored in a plurality of hoppers, selects and discharges a combination of items having a weight close to a measurement target value, a control unit that causes each of the weighing devices to sequentially select a combination; a correction unit that corrects the measurement target value of a weighing device that subsequently performs the combination selection, using a deviation between the combined weight of the items selected by the weighing device that previously performed the combination selection and the measurement target value used for the selection; A combination weighing device in which, even if an item whose weight exceeds the sum of the weighing target value and upper limit value after correction by the correction unit is stored in one of the hoppers of the multiple weighing devices, if the weight of the item does not exceed the sum of the weighing target value and upper limit value before correction by the correction unit, the control unit does not forcibly eject the item stored in that hopper but uses it for the next combination selection.

2. The combination weighing device according to claim 1, wherein the control unit uses the weight of the items stored in the hopper to select the next combination when the weighing target value corrected by the correction unit is smaller than the weighing target value before correction.

3. The combination weighing device according to claim 1 , wherein the control unit forcibly discharges the articles stored in the hopper when the measurement target value corrected by the correction unit is greater than the measurement target value before correction.

4. 2. The combination weighing device according to claim 1, wherein the articles have large individual weights and vary in weight, and each of the hoppers is supplied with one to three articles.

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