combination weigher

Abstract

In the standby state before the driving of the metering conveyor selected as the discharge combination starts, when the weight of the measured objects on the metering conveyor selected as the discharge combination changes, since a combination operation is performed to select a new discharge combination, the measured objects on the metering conveyor with the changed weight will not be selected as the new discharge combination, and will not be directly transported and discharged to the collecting conveyor. In the transport state after the driving of the metering conveyor selected as the discharge combination starts, when the weight of the measured objects on the metering conveyor that has started driving changes, since the driving of at least one of the metering conveyor with the changed weight and the collecting conveyor is stopped, or the transport direction is reversed to drive, the measured objects on the metering conveyor with the changed weight will not be discharged to the packaging machine, etc. at the rear section of the collecting conveyor.

Description

Technical Field

[0001] The present invention relates to a combination weigher for combining and weighing objects so as to achieve a weight within a predetermined weight range and then discharging the objects. Background Art

[0002] Combination weighers can be broadly categorized into automatic, semi-automatic, and manual types based on how the objects are fed into and discharged from the weighing section. In manual combination weighers, the objects are fed and discharged manually. In semi-automatic combination weighers, the objects are fed manually and discharged automatically. Finally, in automatic combination weighers, both the feeding and discharge of objects are automated.

[0003] For objects that cannot be automatically fed to a combination weigher or are not suitable for automatic feeding, a manual or semi-automatic combination weigher is used.

[0004] Conventional semi-automatic combination weighers, such as those described in Patent Document 1, have multiple inlets on the top plate of the main frame. When an operator places objects into these inlets, the objects are fed into weighing hoppers located below the inlets, serving as weighing units, for weight measurement.

[0005] The system calculates the weight combinations of the objects fed to each hopper and selects a discharge combination for the hopper within a specified weight range. The doors of the hoppers in the selected discharge combination are opened, causing the objects to fall onto a transport conveyor. This transport conveyor transports the objects within the specified weight range and discharges them to downstream equipment such as a packaging machine, producing a single package of objects within the specified weight range.

[0006] In this type of semi-automatic combination weigher, between the time the weighing of the objects fed into the weighing hopper is completed and the time the objects are discharged from the weighing hopper of the discharge combination selected by the combination operation, there is a possibility that additional objects may be added to the weighing hopper of the discharge combination due to operator error, for example. If additional objects are added to the weighing hopper in this manner, the additional objects may be discharged onto the transport conveyor along with the objects in the weighing hopper selected as the discharge combination. Consequently, in packaging machines downstream of the transport conveyor, the additional objects may be packaged together with the appropriate objects within the specified weight range, resulting in mis-weighing.

[0007] To prevent this misweighing, the semi-automatic combination weigher disclosed in Patent Document 1 repeatedly calculates the total weight of the objects in the weighing hoppers selected as the discharge combination until the objects are discharged from the weighing hoppers selected as the discharge combination. A check is then performed to determine whether the calculated total is within a specified weight range. If it is outside the specified weight range, it is considered that new objects have been added, and the combination calculation is repeated.

[0008] Patent Document 1: Japanese Utility Model Publication No. 6-10825

[0009] In the semi-automatic combination weigher of Patent Document 1, the combination calculation of the additionally loaded objects is performed again before the weighing hopper for discharging the combination starts discharging, that is, before the door of the weighing hopper is opened, thereby preventing mis-weighing.

[0010] However, if, due to operator error, additional objects are added at the same time as the discharge operation of the weighing hopper begins and the door is opened, the additional objects added along with the objects from the weighing hopper selected as the discharge combination will fall directly onto the transport conveyor. Consequently, the additional objects added along with the objects from the weighing hopper selected as the discharge combination will be discharged via the transport conveyor to a downstream packaging machine, etc. Consequently, in the downstream packaging machine, objects that are not within the specified weight range but that include the additional objects will be packaged together, resulting in mis-weighing. Summary of the Invention

[0011] The present invention has been made in view of this point, and an object of the present invention is to prevent erroneous measurement that occurs after the measuring unit starts the discharge operation.

[0012] In order to achieve the above-mentioned object, the present invention is constructed as follows.

[0013] (1) The combination weigher involved in the present invention comprises: a plurality of weighing conveyors for transporting objects to be weighed and manually feeding the objects to be weighed in a transport stop state; a plurality of weight sensors respectively provided corresponding to the plurality of weighing conveyors for respectively measuring the weight of the objects to be weighed on the weighing conveyors; a collecting conveyor to which the objects to be weighed discharged from the weighing conveyors are fed and for transporting and discharging the fed objects to be weighed; and a control unit for performing a combination operation for selecting a discharge combination based on the weight values ​​measured by the weight sensors and controlling the driving of the plurality of weighing conveyors and the collecting conveyor, wherein the discharge combination is composed of a combination of the weighing conveyors whose total weight of the objects to be weighed supplied to the weighing conveyors is within a prescribed weight range, and the control unit for driving the weighing conveyor selected as the discharge combination to discharge the objects to be weighed onto the collecting conveyor, wherein

[0014] In a standby state before starting to drive the weighing conveyor selected as the discharge combination by the combination calculation, if the weight of the objects to be weighed on the weighing conveyor selected as the discharge combination changes, the control unit performs the combination calculation to select a new discharge combination.

[0015] In the conveying state after the driving of the metering conveyor selected as the discharge combination by the combination operation starts, when the weight of the measured object of the metering conveyor selected as the discharge combination changes, the control unit stops the driving of the metering conveyor with the changed weight and at least one of the collecting conveyors, or reverses the conveying direction of the at least one conveyor to drive it.

[0016] According to the combination weigher of the present invention, in a standby state before the start of driving of the weighing conveyor selected as the discharge combination by the combination calculation, if, for example, an operator mistakenly adds objects to the weighing conveyor selected as the discharge combination or mistakenly removes a portion of the objects on the weighing conveyor, thereby causing the weight of the objects on the weighing conveyor to change, combination calculation is performed to select a new discharge combination, that is, combination calculation is re-performed to select a new discharge combination. Therefore, the objects on the weighing conveyor to which the objects were added or removed are not selected as the new discharge combination and are not directly conveyed to the collecting conveyor, thereby preventing mis-weighing.

[0017] Furthermore, in the conveying state after the driving of the metering conveyor selected as the discharge combination by the combination operation starts, if the operator mistakenly supplies additional objects to be weighed on the metering conveyor selected as the discharge combination, or the operator mistakenly removes part of the objects to be weighed on the metering conveyor, etc., so that the weight of the objects to be weighed on the metering conveyor changes, the driving of at least one of the metering conveyor and the collecting conveyor with the changed weight is stopped, or the conveying direction of the at least one conveyor is reversed to drive.

[0018] Therefore, by stopping the drive of at least one of the weighing conveyor and the collecting conveyor, it is possible to prevent the weighing conveyor's objects, which have been added or partially removed, from remaining on the weighing conveyor or the collecting conveyor. Alternatively, the at least one conveyor can be reversed to transport and collect them in the direction opposite to their original transport direction. This prevents the weighing conveyor's objects, which have been added or partially removed, from being discharged to a packaging machine or the like downstream of the collecting conveyor, thereby preventing mis-weighing.

[0019] In particular, in the present invention, even if the measured objects of the measuring conveyor with added measured objects or a part of the measured objects removed are discharged to the collecting conveyor, the driving of the collecting conveyor is stopped or the conveying direction of the collecting conveyor is reversed to drive it, and the measured objects will not be discharged to the packaging machine at the rear section of the collecting conveyor, thereby preventing mismeasurement.

[0020] (2) In a preferred embodiment of the present invention, in the conveying state after the driving of the metering conveyor selected as the discharge combination by the combination operation starts, when the weight of the measured object of the metering conveyor selected as the discharge combination changes, the control unit stops the driving of the collecting conveyor, or reverses the conveying direction of the collecting conveyor to drive it.

[0021] According to this embodiment, in the conveying state after the driving of the metering conveyor selected as the discharge combination by the combination operation starts, for example, the operator mistakenly supplies additional measured objects to the metering conveyor selected as the discharge combination, or the operator mistakenly removes a part of the measured objects on the metering conveyor, etc., so that the weight of the measured objects on the metering conveyor changes, the driving of the collecting conveyor is stopped, or the conveying direction of the collecting conveyor is reversed. Therefore, the measured objects of the metering conveyor with the added measured objects or the removed part of the measured objects will not be conveyed through the collecting conveyor to the packaging machine, etc. at the rear section which is the original conveying direction, thereby preventing mismeasurement.

[0022] (3) In another embodiment of the present invention, the control unit starts driving the weighing conveyor selected as the discharge combination in response to input of a discharge request signal.

[0023] According to this embodiment, the control unit can respond to a discharge request signal from a packaging machine or the like downstream of the collecting conveyor by starting to drive the weighing conveyor selected as the discharge combination, thereby discharging the objects on the weighing conveyor onto the collecting conveyor. Thus, the collecting conveyor can transport the objects from the weighing conveyor selected as the discharge combination and discharge them onto the packaging machine or the like downstream.

[0024] (4) In another embodiment of the present invention, there is provided: a notification unit controlled by the control unit, and when the control unit stops driving the at least one conveyor or reverses the conveying direction of the at least one conveyor to drive, the notification unit notifies that the measured object is incorrectly supplied to the measuring conveyor.

[0025] As described above, in the conveying state after the driving of the metering conveyor selected as the discharge combination starts, for example, the operator mistakenly supplies additional measured objects on the metering conveyor selected as the discharge combination, or the operator mistakenly removes part of the measured objects on the metering conveyor, etc., the driving of at least one of the metering conveyor with changed weight and the collecting conveyor is stopped, or the conveying direction of the at least one conveyor is reversed to drive.

[0026] According to this embodiment, when the drive of at least one of the metering conveyor and the collecting conveyor is stopped, or the conveying direction of the at least one conveyor is reversed to drive, the notification unit notifies that the metering conveyor is incorrectly supplied with the measured object, so that the operator can easily identify the reason why the drive of the conveyor is stopped or driven in reverse and take appropriate measures.

[0027] (5) In another embodiment of the present invention, the plurality of metering conveyors are arranged in parallel, the collecting conveyor transports the measured objects discharged from the metering conveyors along the parallel direction of the plurality of metering conveyors, and a metering conveyor group composed of the plurality of metering conveyors is respectively provided on both sides of the collecting conveyor in a manner of clamping the collecting conveyor.

[0028] According to this embodiment, by arranging the weighing conveyor groups on both sides of the collecting conveyor, the length of the collecting conveyor can be shortened, the discharge time of the objects to be weighed can be shortened, and the combination weigher can be made more compact.

[0029] Thus, according to the present invention, when the weight of the objects on the weighing conveyor fluctuates due to an operator's erroneous feeding of objects while the weighing conveyor, which has been selected as a discharge combination by combinatorial calculation, is in a standby state before the start of driving, combinatorial calculation is performed to select a new discharge combination. As a result, objects on the weighing conveyor with fluctuating weight are not selected as the new discharge combination and are not directly conveyed to the collecting conveyor, thereby preventing mis-weighing.

[0030] Furthermore, if the weight of the objects on the weighing conveyor fluctuates due to an operator's erroneous feeding of objects after the weighing conveyor selected as the discharge combination by the combination operation has begun driving, the operation of at least one of the weighing conveyor with the fluctuating weight and the collecting conveyor is stopped, or the conveying direction of the at least one conveyor is reversed. This prevents the objects on the weighing conveyor with the fluctuating weight from being discharged to a packaging machine or the like downstream of the collecting conveyor, thereby preventing mis-weighing.

[0031] In particular, in the present invention, even if the weighing objects of the weighing conveyor with fluctuating weight are discharged to the collecting conveyor, the driving of the collecting conveyor is stopped or the conveying direction of the collecting conveyor is reversed to drive it, so that the objects will not be discharged to the packaging machine etc. at the rear section of the collecting conveyor, thereby preventing mismeasurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a top view showing a combination weighing machine according to one embodiment of the present invention.

[0033] Figure 2 yes Figure 1 Front view of the combination weigher.

[0034] Figure 3 yes Figure 1 Block diagram of a combination weigher.

[0035] Figure 4 Is used to illustrate Figure 1 Flowchart of the operation of the combination weigher.

[0036] Figure 5 is with Figure 4 Continuous flow chart. DETAILED DESCRIPTION

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0038] Figure 1 is a top view of a combination weighing machine according to an embodiment of the present invention. Figure 2 is its main view.

[0039] The combination weigher 1 of this embodiment is a semi-automatic combination weigher in which an operator manually supplies objects to be weighed and automatically discharges objects within a specified weight range. The combination weigher 1 comprises: a collecting conveyor 2 consisting of a belt conveyor that conveys objects to be weighed in the direction of arrow A; a weighing conveyor 3 consisting of a plurality of (in this example, twelve) belt conveyors arranged in two rows along the conveying direction of the collecting conveyor 2; and a weighing conveyor 3 supported on a belt conveyor. Figure 2 The apparatus main body 5 on the stand 4 shown, and a touch panel type operation setting display 6 for setting parameters for operation control and displaying the operating status are provided.

[0040] like Figure 1 As shown, a display lamp 8 serving as a notification unit is provided on the side of each weighing conveyor 3. By flashing, the display lamp 8 notifies the operator of the mistaken feeding of objects to the weighing conveyor 3. Reference numeral 9 denotes an emergency stop switch for stopping the combination weigher 1 in an emergency.

[0041] The collecting conveyor 2 is used to convey the objects discharged from the weighing conveyor 3 selected as the discharge combination by the combination operation to the Figure 1 The objects are transported in the direction of arrow A and discharged to a subsequent device such as a packaging machine (not shown), where the discharged objects are bagged by the packaging machine.

[0042] The object to be measured is not particularly limited, and for example, vegetables such as cut vegetables, mushrooms, and carrots, and foods such as fish or meat that have been cut into pieces are preferable.

[0043] On either side of the collecting conveyor 2, two rows of six weighing conveyors 3 are arranged in a straight line along the conveying direction of the collecting conveyor 2, forming two weighing conveyor groups. The conveying direction of each weighing conveyor 3, as indicated by arrow B, is perpendicular to the conveying direction A of the collecting conveyor 2. The step difference between the weighing conveyors 3 and the collecting conveyor 2 is small, which reduces the impact when the objects discharged from the weighing conveyor 3 are transferred to the collecting conveyor 2.

[0044] In the form of sandwiching two rows of metering conveyors, there are three groups of Figure 1 In the figure, a loading platform (not shown) is arranged below the three weighing conveyors in the lower row and above the three weighing conveyors in the upper row. Objects to be weighed are stored on these loading platforms.

[0045] The operator places the objects to be weighed accumulated on the input table onto the empty weighing conveyor 3 in the transport stop state by manual operation, that is, manual feeding.

[0046] Each weighing conveyor 3 is driven by a drive motor located below it. Each weighing conveyor 3 and its drive motor are supported by weight sensors (not shown), such as load cells, located within the main unit 5 of the device. Load signals from the weight sensors are supplied to a control unit, described later. The control unit calculates the weight of the objects on the weighing conveyor 3 and controls the discharge of the objects supplied to each weighing conveyor 3.

[0047] Figure 3 This is a block diagram showing the schematic structure of the combination weighing machine 1 of this embodiment. Figure 1 、 Figure 2 Corresponding parts are marked with the same reference numerals.

[0048] The combination weigher 1 includes: first and second conveyor drive circuit units 10 and 11 for driving the weighing conveyors 3 and the collecting conveyor 2 respectively; an indicator light drive circuit unit 12 for driving the indicator lights 8; an A / D converter unit 13 for performing A / D conversion on the analog load signal from the weight sensor 16; a control unit 14 for filtering and combining the digital load signal from the A / D converter 13 and controlling the various units; and an I / O circuit unit 15.

[0049] As described above, each weighing conveyor 3 is supported by a weight sensor 16, such as a load cell. These weight sensors 16 detect the weight of the objects on the weighing conveyor 3. The analog load signal, which is the detection signal, is converted into a digital load signal by the A / D converter 13 and transmitted to the control unit 14.

[0050] The control unit 14 includes a calculation control unit 17 composed of a CPU and the like, and a storage unit 18 composed of a memory such as a RAM and a ROM. The storage unit 18 stores operating programs, operation parameter data, measurement data, and the like.

[0051] The control unit 14 controls the entire combination weigher 1 and performs processing such as combination calculations by causing the calculation control unit 17 to execute an operation program stored in the storage unit 18 .

[0052] The control unit 14 controls the drive of each weighing conveyor 3 via the first conveyor drive circuit unit 10 and the drive of the collecting conveyor 2 via the second conveyor drive circuit unit 11, thereby controlling the discharge of the objects. Furthermore, the control unit 14 receives discharge request signals from the downstream packaging machine via the I / O circuit unit 15 and, when discharge of the objects is complete, outputs a discharge completion signal to the downstream packaging machine. The control unit 14 receives signals corresponding to setting operations from the operation setting display 6 and outputs display signals such as data displayed on the operation setting display 6.

[0053] In the combination weigher 1 having the above-described structure, an operator manually places objects on an empty weighing conveyor 3 that is stopped. The control unit 14 filters the digital load signal from the A / D converter 13, obtains the weight of the objects, and performs a combination calculation. This combination calculation selects a discharge combination, which is a combination of weighing conveyors 3 whose combined weight, the total weight of various combinations of the weights of the objects on each weighing conveyor 3, falls within a specified weight range. If multiple discharge combinations fall within the specified weight range, the one with the smallest absolute difference between the combined weight and the target combined weight is selected. Then, in response to a discharge request signal from a downstream packaging machine, the control unit 14 starts driving the weighing conveyor 3 selected as the discharge combination and also starts driving the collecting conveyor 2. By driving the weighing conveyor 3 for a first specified time, the objects on the weighing conveyor 3 are discharged onto the collecting conveyor 2. By driving the collecting conveyor 2 for a second predetermined time, the objects discharged from the weighing conveyor 3 are transported and discharged to the subsequent packaging machine. The control unit 14 outputs a discharge completion signal to the subsequent packaging machine at a predetermined timing. The above-described operation is repeated.

[0054] In the above operation, when the weighing conveyor 3 carrying the objects to be weighed is selected as the discharge combination, the weighing conveyor 3 is in a non-driven standby state until a discharge request signal is input.

[0055] In this standby state, since objects are already placed on the weighing conveyor 3 , that is, the weighing conveyor 3 is not empty, the operator should not, for example, supply additional objects to the weighing conveyor 3 or remove some of the already placed objects.

[0056] However, sometimes, in order to ensure the necessary production volume, unskilled operators who are in a hurry to perform the work judge that the amount of the objects to be measured on the weighing conveyor 3 is small or large, and thus mistakenly supply additional objects to the weighing conveyor 3 in the standby state or remove part of the objects to be measured on the weighing conveyor 3.

[0057] In this way, after the weighing conveyor 3 in the standby state is mistakenly added with the weighing objects or a part of the weighing objects is removed, when the weighing conveyor 3 in the standby state is driven in response to the input of the discharge request signal from the subsequent packaging machine, the weighing conveyor 3 in the standby state is transported by the weighing conveyor 3 and discharged to the collecting conveyor 2 with a weight heavier or lighter than that of the weighing objects selected as the discharge combination, thereby causing mismeasurement.

[0058] Furthermore, an unskilled operator as described above may hastily add objects to the weighing conveyor 3 or remove some of the objects in a transport state in which the weighing conveyor 3 has started driving, not only in the standby state, but also in the conveying state. In this case, mis-weighing may also occur.

[0059] In this embodiment, the following operation is performed to prevent mis-weighing caused by an operator mistakenly supplying objects to the weighing conveyor 3 in the standby state or the weighing conveyor 3 in the transport state where driving has started.

[0060] Specifically, in this embodiment, the weight of the objects on the weighing conveyor 3 selected as the discharge combination is monitored. If the weight of the objects changes during the standby state, the discharge combination is canceled and the combination calculation is performed again to select a new discharge combination. Similarly, the weight of the weighing conveyor for the newly selected discharge combination is monitored. If the weight of the objects changes during the standby state, the discharge combination is canceled and the combination calculation is performed again to select a new discharge combination.

[0061] Thus, objects on the weighing conveyor 3 whose weight has changed from the weight at the time of being selected as the discharge combination are not selected as the new discharge combination and are not conveyed to the collecting conveyor 2, thereby preventing mis-weighing.

[0062] In addition, in the conveying state after the driving of the metering conveyor 3 selected as the discharge combination is started, the weight of the measured objects on the metering conveyor 3 that has started to be driven is also monitored. When the weight of the measured objects changes, for example, the display light 8 serving as the notification unit flashes to notify that the supply of the measured objects to the metering conveyor 3 is incorrect, and the collecting conveyor 2 is stopped, or the conveying direction of the collecting conveyor 2 is reversed to discharge the measured objects in the reverse direction.

[0063] This prevents objects on the weighing conveyor 3 whose weight has fluctuated from the weight at the time the discharge combination is selected from being conveyed by the collecting conveyor 2 to the subsequent packaging machine in the original conveying direction, thereby preventing mis-weighing.

[0064] Furthermore, the notification regarding the error in the supply of the objects to the weighing conveyor 3 is not limited to the display by the indicator lamp 8 , and may be a notification by sound such as a buzzer, or a combination thereof.

[0065] Then, according to Figure 4 An example of the above-mentioned mis-weighing prevention operation of the combination weighing machine according to this embodiment will be described with reference to the flowchart of FIG.

[0066] First, the combination weigher begins operation. The operator places objects on an empty weighing conveyor 3 that is stopped (step S1). The load signal from the weight sensor 16 corresponding to the weighing conveyor 3 undergoes A / D conversion (step S2) and further filtering (step S3). The load signal stabilizes and the weight value is determined (step S4). A combination calculation is performed based on the determined weight value of the objects on the weighing conveyor 3 (step S5). A determination is made as to whether the discharge combination for the weighing conveyor 3 that should discharge the objects has been selected (i.e., whether the discharge combination is established) (step S6). If the discharge combination is not established, the process returns to step S2.

[0067] When the discharge combination is established in step S6, it is determined whether a discharge request signal is input from the packaging machine at the subsequent stage (step S7). When the discharge request signal is input, the process proceeds to the following step. Figure 5 The discharge processing is considered to be in a standby state when there is no input of the discharge request signal, and transfers to step S8.

[0068] In step S8, the load signal from the weight sensor 16 corresponding to the weighing conveyor 3 selected as the discharge combination is A / D converted, further filtered (step S9), and the weight value is determined (step S10). It is determined whether the determined weight value has changed relative to the weight value at the time the discharge combination was selected, that is, whether the weight value has increased or decreased (step S11). If the weight value has not increased or decreased, the process returns to step S7. In addition, in step S11, if the weight value has increased or decreased, it is deemed that the operator has added a weighing conveyor 3 or removed a portion of the weighing conveyor 3 due to an error in the standby state, and the selected discharge combination is canceled (step S12). The process returns to step S2, obtains the weight value, and performs the combination calculation again.

[0069] In the above step S6, the discharge combination is established, and in the above step S7, when the discharge request signal is input from the packaging machine at the rear stage, the process is transferred to Figure 5 The process shown is to discharge the objects from the weighing conveyor 3 selected as the discharge combination.

[0070] like Figure 5As shown, the driving of the weighing conveyor 3 selected as the discharge combination begins (step S13), the load signal from the weight sensor 16 corresponding to the driven weighing conveyor 3 is A / D converted (step S14), and further filtering is performed (step S15). Since this filtering process is performed in the transport state after the weighing conveyor 3 is driven, it is different from the filtering process in the static state after the weighing conveyor 3 is stopped, as in steps S3 and S9, and the filtering coefficient is changed to a coefficient value suitable for attenuating the vibration noise of the weighing conveyor 3. When the weight value after this filtering process is determined (step S16), it is determined whether this weight value has decreased compared to the weight value at the time the discharge combination was selected (step S17).

[0071] In step S17, when the weight value decreases, it is determined whether the weight value decreases to near zero g (step S18). When the weight value decreases to near zero g, it is considered that the objects on the weighing conveyor 3 are normally discharged to the collecting conveyor 2 and the process ends (step S19).

[0072] In step S18, if the weight value decreases but does not decrease to near zero g, it is considered that a portion of the weighing conveyor 3 has been removed due to operator error while the weighing conveyor 3 selected as the discharge combination is being driven and started, i.e., there is an error in the supply of the weighing conveyor 3. The display light 8 flashes to notify this, and the collecting conveyor 2 is stopped or driven in reverse, and the weighing conveyor 2 is transported in the reverse direction and recovered in a recovery container (not shown) (step S22). In the case of stopping the collecting conveyor 2, the operator recovers the weighing conveyor 2.

[0073] In the above-mentioned step S17, when the weight value has not decreased relative to the weight value at the moment when the discharge combination is selected, it is determined whether the weight value has increased relative to the weight value at the moment when the discharge combination is selected (step S20). When the weight value has increased, it is deemed that the weighing conveyor 3 is additionally supplied with the measured objects due to the operator's error in the conveying state after the driving of the weighing conveyor 3 selected as the discharge combination is started, that is, the measured objects are erroneously supplied, so that the display light 8 flashes to notify, and the collecting conveyor 2 is stopped or the collecting conveyor 2 is driven in reverse rotation, and the measured objects on the collecting conveyor 2 are conveyed in reverse and recovered into the recovery container (step S21).

[0074] In the above-mentioned step S20, if the weight value has not increased, it is considered that the weight value has not changed, and the process returns to step S14.

[0075] As described above, according to this embodiment, in the standby state before the start of driving of the weighing conveyor 3 selected as the discharge combination by the combination calculation, if the operator mistakenly adds objects to the weighing conveyor 3 selected as the discharge combination, or if the operator mistakenly removes some objects from the weighing conveyor 3, the combination calculation is re-performed to select a new discharge combination. As a result, the objects on the weighing conveyor 3 that was mistakenly supplied with objects will not be selected as the new discharge combination and will not be directly conveyed to the collecting conveyor 2, thereby preventing mis-weighing.

[0076] Furthermore, while the weighing conveyor 3 selected as the discharge combination by the combination operation has begun driving, if the operator mistakenly adds objects to the weighing conveyor 3 selected as the discharge combination, or mistakenly removes some objects from the weighing conveyor 3, the indicator light 8 flashes to notify the operator of the mistaken feeding of objects, and the driving of the collecting conveyor 2 is stopped or reversed. This allows the objects to remain on the collecting conveyor 2 or be transported and collected by the collecting conveyor 2 in a direction opposite to the intended conveying direction. Consequently, the objects to the weighing conveyor 3 mistakenly fed with objects are prevented from being discharged to the packaging machine downstream of the collecting conveyor 2, thereby preventing mis-weighing.

[0077] In particular, even if the objects to be measured of the measuring conveyor 3 with added objects or a part of the objects to be measured removed are discharged to the collecting conveyor 2, the driving of the collecting conveyor 2 is stopped or the conveying direction of the collecting conveyor 2 is reversed, so that the objects will not be discharged to the packaging machine at the rear of the collecting conveyor 2, thereby preventing mismeasurement.

[0078] In the above embodiment, when the weighing conveyor 3 selected as the discharge combination has started driving and the objects are mistakenly fed onto the weighing conveyor 3 selected as the discharge combination, the driving of the collecting conveyor 2 is stopped or the conveying direction thereof is reversed. However, as another embodiment, for example, the driving of the weighing conveyor 3 may be stopped or the conveying direction thereof may be reversed while the conveying distance of the weighing conveyor 3 is relatively long and the mistakenly fed objects are on the weighing conveyor 3. Alternatively, the driving of both the weighing conveyor 3 and the collecting conveyor 2 may be stopped or the conveying directions thereof may be reversed.

[0079] In the above embodiment, a packaging machine is arranged at the rear section of the collecting conveyor 2, but as another embodiment, for example, an operator can receive the weighed objects discharged from the collecting conveyor 2 in a packaging bag, etc., and the operator operates a nearby switch to input a discharge request signal to the combination weigher 1.

[0080] Description of Reference Numerals

[0081] 1 combination weigher

[0082] 2 collection conveyors

[0083] 3 metering conveyor

[0084] 6 Operation setting display

[0085] 8 indicator lights (reporting department)

[0086] 14 Control Unit

Claims

1. A combination weigher having: a plurality of metering conveyors for transporting objects to be measured and for manually feeding the objects to be measured when the transport is stopped; A plurality of weight sensors are respectively provided corresponding to the plurality of metering conveyors, and are used to respectively measure the weight of the objects on the metering conveyors; a collecting conveyor supplied with the objects discharged from the measuring conveyor and configured to transport and discharge the supplied objects; as well as A control unit for performing a combination operation for selecting a discharge combination based on the weight value measured by the weight sensor and controlling the driving of the plurality of weighing conveyors and the collecting conveyor, wherein the discharge combination is composed of a combination of the weighing conveyors whose total weight of the objects supplied to the weighing conveyors is within a prescribed weight range, and the control unit is for driving the weighing conveyors selected as the discharge combination to discharge the objects to the collecting conveyor, wherein In a standby state before starting to drive the weighing conveyor selected as the discharge combination by the combination calculation, if the weight of the objects to be weighed on the weighing conveyor selected as the discharge combination changes, the control unit performs the combination calculation to select a new discharge combination. In the conveying state after the driving of the metering conveyor selected as the discharge combination by the combination operation starts, when the weight of the measured object of the metering conveyor selected as the discharge combination changes, the control unit stops the driving of the metering conveyor with the changed weight and at least one of the collecting conveyors, or reverses the conveying direction of the at least one conveyor to drive it.

2. The combination weigher according to claim 1, wherein: In the conveying state where the metering conveyor selected as the discharge combination through the combination operation has started to drive, when the weight of the measured object of the metering conveyor selected as the discharge combination changes, the control unit stops driving the collecting conveyor or reverses the conveying direction of the collecting conveyor to drive it.

3. The combination weigher according to claim 1, wherein: The control unit starts driving the weighing conveyor selected as the discharge combination in response to input of a discharge request signal.

4. The combination weigher according to claim 2, wherein: The control unit starts driving the weighing conveyor selected as the discharge combination in response to input of a discharge request signal.

5. The combination weigher according to any one of claims 1 to 4, further comprising a notification unit controlled by the control unit, wherein when the control unit stops driving the at least one conveyor or drives the at least one conveyor in a reversed conveying direction, the notification unit notifies that the objects to be weighed are erroneously supplied to the weighing conveyor.

6. The combination weigher according to any one of claims 1 to 4, wherein: The multiple metering conveyors are arranged in parallel. The collecting conveyor is used to transport the objects discharged from the weighing conveyor along the parallel direction of the plurality of weighing conveyors. A metering conveyor group consisting of the plurality of metering conveyors is respectively provided on both sides of the collecting conveyor in a manner of sandwiching the collecting conveyor.

7. The combination weigher according to claim 5, wherein: The multiple metering conveyors are arranged in parallel. The collecting conveyor is used to transport the objects discharged from the weighing conveyor along the parallel direction of the plurality of weighing conveyors. A metering conveyor group consisting of the plurality of metering conveyors is respectively provided on both sides of the collecting conveyor in a manner of sandwiching the collecting conveyor.

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