Weighing and conveying device, and weighing and conveying packaging device

Abstract

To provide a weighing and conveying device and a weighing and conveying packaging device that can expand the range of weights of items that can be conveyed while ensuring safety. [Solution] The weighing and conveying device 1 comprises a weighing unit 2 for weighing articles, a conveying unit 3 for conveying articles weighed by the weighing unit 2 by operating a drive motor, a conveying control unit that starts conveying articles by the conveying unit 3 when the weight of the articles weighed by the weighing unit 2 is less than or equal to the upper limit weight, a switching unit for switching the conveying speed of the conveying unit 3, and a storage unit that stores the upper limit weight for each conveying speed switched by the switching unit. Each upper limit weight stored in the storage unit is the weight of the article when the load current generated in the drive motor when conveying the article at the corresponding conveying speed becomes the maximum allowable load current of the drive motor.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a weighing and conveying device and a weighing and conveying packaging device. [Background technology]

[0002] Patent Document 1 describes a weighing and conveying device (packaging device) comprising: a placement section on which articles (items to be packaged) are placed; a packaging section for packaging the articles; a conveying section for transporting the articles placed on the placement section to the packaging section; a detection section for acquiring the load applied to a drive motor that drives the conveying section; and a determination section for determining that the drive motor is in an overload state when the magnitude of the load acquired by the detection section is equal to or greater than a standard load. In a weighing and conveying device with this configuration, the transport of articles is stopped when an unintended load is applied to the conveying motor, thereby increasing safety. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2017-056989 [Overview of the project] [Problems that the invention aims to solve]

[0004] In such weighing and conveying devices, for safety reasons, it is conceivable that, when conveying goods at a predetermined conveying speed, if the load on the drive motor calculated from the conveying speed and the weight of the goods exceeds a standard load, the device may be designed to prevent the conveying of goods from starting, even if the goods are placed on the conveying unit.

[0005] However, in this case, if an item weighing more than the standard load is placed on the conveying unit when the item is being conveyed at a predetermined conveying speed, the conveying unit will not be able to start conveying, thus limiting the range of weights that can be conveyed by the weighing and conveying device. In particular, for example, during times when families gather, there is a tendency for users to have to weigh heavier items than they anticipated at once. In such cases, if the conveying unit is deemed overloaded and the conveying of items does not start, the items must be packaged manually, which reduces productivity.

[0006] Therefore, one aspect of the present invention is to provide a weighing and conveying device and a weighing and conveying packaging device that can expand the range of weights of articles that can be conveyed while ensuring safety. [Means for solving the problem]

[0007] (1) A weighing and conveying device according to one aspect of the present invention comprises: a weighing unit for weighing an article; a conveying unit for conveying the article weighed by the weighing unit by operating a drive motor; a conveying control unit for initiating the conveying of the article by the conveying unit when the weight of the article weighed by the weighing unit is less than or equal to an upper limit weight; a switching unit for switching the conveying speed of the conveying unit; and a storage unit for storing an upper limit weight for each conveying speed switched by the switching unit, wherein each upper limit weight stored in the storage unit is the weight of the article when the load current generated in the drive motor when the article is conveyed at the corresponding conveying speed becomes the maximum allowable load current of the drive motor.

[0008] In this weighing and conveying device configuration, different upper weight limits are stored for different conveying speeds. Even if the weight of an item exceeds one upper weight limit, the conveying speed can be switched to set a different upper weight limit. If the new upper weight limit set when the conveying speed is switched is equal to or greater than the weight of the item weighed by the weighing unit, that is, if the weight of the item is less than or equal to the new upper weight limit, the conveying control unit starts conveying the item in the conveying unit. This ensures safety by not starting conveying when the weight of the item exceeds the upper weight limit, while expanding the weight range of items that the conveying unit can convey by switching the conveying speed.

[0009] (2) In the weighing and conveying device described in (1) above, the switching unit is switchable between a first conveying speed and a second conveying speed that is slower than the first conveying speed. The first upper limit weight corresponding to the first conveying speed is the weight at which the load current of the drive motor generated when conveying an item at the first conveying speed becomes the maximum allowable load current of the drive motor. The second upper limit weight corresponding to the second conveying speed may be greater than the first upper limit weight and is the weight at which the load current of the drive motor generated when conveying an item at the second conveying speed becomes the maximum allowable load current of the drive motor. In this configuration, the first upper limit weight is stored for the first conveying speed, and the second upper limit weight, which is greater than the first upper limit weight, is stored for the second conveying speed that is slower than the first conveying speed. As a result, even if the weight of an item exceeds the first upper limit weight, the item can be conveyed by switching to the second conveying speed corresponding to the second upper limit weight, which is greater than the first upper limit weight.

[0010] (3) The weighing and conveying device described in (1) or (2) above may further be provided with a display unit that indicates when the weight of the item is greater than the upper limit weight corresponding to the conveying speed. In this configuration, the user can recognize that the weight of the item is greater than the upper limit weight through the display unit, and can take appropriate action, such as switching the conveying speed. This makes it possible to operate the weighing and conveying device even more safely.

[0011] (4) In the weighing and conveying device described in any one of (1) to (3) above, the switching unit may switch to a conveying speed corresponding to an upper limit weight greater than the weight of the item when the weight of the item weighed by the weighing unit is greater than the upper limit weight corresponding to the conveying speed. In this configuration, the item is conveyed at a conveying speed corresponding to an upper limit weight greater than the weight of the item, so the item can be conveyed quickly while ensuring safety.

[0012] (5) A weighing and conveying device as described in any one of (1) to (4) above, further comprising a selection unit for selecting a first mode or a second mode, wherein when the selection unit selects the first mode, the conveying control unit executes control to start conveying the item in the conveying unit based on the upper limit weight corresponding to the conveying speed switched by the switching unit and the weight of the item, and also executes control to stop conveying the item based on the load current of the drive motor and a first allowable load current stored in the storage unit in advance, and when the selection unit selects the second mode, the conveying control unit executes control to start conveying the item in the conveying unit based on one upper limit weight stored in the storage unit regardless of the conveying speed switched by the switching unit, and also executes control to stop conveying the item based on the load current of the drive motor and a second allowable load current stored in the storage unit in advance for each conveying speed. In this configuration, it is possible to select between a first mode in which heavier items can be conveyed by slowing down the conveying speed, and a second mode in which, although it is not possible to convey heavier items by slowing down the conveying speed, safety during item conveying can be enhanced. As a result, by appropriately selecting the mode, the specifications of a single weighing and conveying device can be switched to specifications that prioritize productivity or specifications that prioritize safety.

[0013] (6) A weighing and conveying packaging device according to one aspect of the present invention comprises a weighing and conveying device described in any one of (1) to (5), and a packaging unit located downstream of the conveying unit, wherein the packaging unit wraps the articles in film and discharges them. In a weighing and conveying packaging device with this configuration, articles conveyed by the conveying unit can be wrapped in film. [Effects of the Invention]

[0014] According to one aspect of the present invention, while ensuring safety, the range of the weight of articles that can be conveyed can be widened.

Brief Description of the Drawings

[0015] [Figure 1] FIG. 1 is a perspective view showing a weighing and conveying packaging device according to a first embodiment. [Figure 2] FIG. 2 is a block diagram of the weighing and conveying device of FIG. 1. [Figure 3] FIG. 3 is a diagram showing an example of the allowable maximum load current. [Figure 4] FIG. 4 is a flowchart showing the operation of the weighing and conveying packaging device. [Figure 5] FIG. 5 is a diagram showing a warning message displayed on the display unit. [Figure 6] FIG. 6 is a diagram showing an example of a second allowable load current. [Figure 7] FIG. 7 is a flowchart showing the operation of the weighing and conveying device according to a second embodiment. [Figure 8] FIG. 8 is a flowchart showing the operation of the weighing and conveying device according to a modification.

Modes for Carrying Out the Invention

[0016] Hereinafter, referring to the drawings, a weighing and conveying packaging device 100 including a weighing and conveying device 1 according to a first embodiment of one aspect of the present invention will be described in detail. In the description of the drawings, the same reference numerals are assigned to the same elements, and redundant descriptions are omitted.

[0017] [[ID=At44]] The weighing, conveying, and packaging device 100 shown in Figures 1 and 2 is a device that weighs an item, wraps the item in stretch film, and then issues a product label printed with information about the item and affixes it to the stretch film. An item is an unpackaged item to be weighed. A product is a packaged item to be weighed. The weighing, conveying, and packaging device 100 comprises a weighing and conveying device 1 that weighs and conveys the item, a packaging unit 101 that wraps the item weighed and conveyed by the weighing and conveying device 1 in stretch film and discharges it, a printing unit 102 that issues a product label based on information about the product, and an attachment unit 103 that affixes the product label issued by the printing unit 102 to the film that has wrapped the product. Various operations of the weighing, conveying, and packaging device 100 are controlled by a control unit 7, which will be described later.

[0018] The weighing and conveying device 1 comprises a weighing unit 2 for weighing the weight of an item, a conveying unit 3 for conveying the item weighed by the weighing unit 2, a load detection unit 4 for detecting the load on the conveying unit 3, a display unit 5 for displaying various information for the user, an input unit 6 that can receive user input, a control unit 7, and a storage unit 8 that stores information necessary for the operation of the weighing and conveying packaging device 100. The weighing unit 2 is located in the center of the front of the main body 100a. The weighing unit 2 has a weighing platform 21 that is loaded with a load sensor such as a load cell to weigh an item such as food placed on a tray. When an item is placed on the weighing platform 21, the weight of the item is measured by the load sensor supporting the weighing platform 21. The weighing unit 2 outputs the measured weight of the item to the control unit 7.

[0019] The transport unit 3 transports the articles placed on the weighing platform 21 to the packaging unit 101. The transport unit 3 includes a chain conveyor 31 that transports the articles placed on the weighing platform 21 to the packaging unit 101 by pushing their backsides, for example, with a transport bar, and a drive motor 32 that moves the chain conveyor 31. The articles are transported to the packaging unit 101 when the drive motor 32 is activated. When transporting articles from the weighing platform 21 to the packaging unit 101, the transport unit 3 accelerates at a predetermined acceleration until it reaches a predetermined transport speed, then transports at the predetermined transport speed for a certain period of time, and then decelerates at a predetermined deceleration until it stops. The same value of acceleration is set for all transport speeds. Different values ​​of acceleration may be set for each transport speed. The same value of deceleration is set for all transport speeds. Different values ​​of deceleration may be set for each transport speed. In the first embodiment, the transport unit 3 is configured to allow switching between three predetermined transport speeds when transporting items from the weighing table 21 to the packaging unit 101: "low speed," "medium speed" (faster than "low speed"), and "high speed" (faster than "medium speed"). The number of switchable transport speeds in the transport unit 3 may be two, more than three, or stepless, allowing for continuous change in transport speed. Each of the multiple transport speeds is stored in the storage unit 8.

[0020] The load detection unit 4 detects the load (transport load) applied to the drive motor 32. The transport load is the load generated on the drive motor 32 while the transport bar pushes and transports the goods from the weighing platform 21 to the packaging unit 101. The transport load is a load corresponding to the force with which the transport bar pushes the goods. A current corresponding to the transport load is applied to the drive motor 32. More specifically, a larger current is applied to the drive motor 32 as the transport load increases. In the first embodiment, the load detection unit 4 measures the current (load current) applied to the drive motor 32. The measured value of the load current measured by the load detection unit 4 is output to the control unit 7. In the first embodiment, the display unit 5 and the input unit 6 are integrally configured and are a touch panel that can display various information for the user and accept user operations. Details of the control unit 7 will be described later.

[0021] The packaging section 101 is located downstream of the conveying section 3. The packaging section 101 includes a lift mechanism 111 for raising the article to a predetermined position, a film roll support mechanism 112 for supporting the stretch film, a film delivery mechanism 113 for feeding the stretch film to a predetermined position, a folding mechanism 114 for folding the stretch film towards the bottom of the article, and a sealing mechanism 115 for sealing the stretch film.

[0022] The lift mechanism 111 raises the item received from the weighing unit 2 to a predetermined position and lifts the stretch film stretched in that position from below by the film delivery mechanism 113. The folding mechanism 114 folds the stretch film lifted by the item towards the bottom of the item to package it. The sealing mechanism 115 heat-seals the stretch film that has been folded towards the bottom of the product by the folding mechanism 114.

[0023] The printing unit 102 is positioned above the folding mechanism 114 and the sealing mechanism 115. The printing unit 102 is integrally configured with the adhesive unit 103. The printing unit 102 acquires printing information to be printed on the label from the printing memory. The printing unit 102 stores a label roll in which the labels are wound around a core material, and issues product labels by printing information based on the printing information onto the labels unwound from the label roll. The labels may be backed labels with a backing sheet attached, or backing-less labels without a backing sheet attached.

[0024] The adhesive section 103 is provided so as to be movable between the printing section 102 and the product to which the product label is to be attached. The adhesive section 103 attaches the product label received from the printing section 102 to a predetermined position on the film-wrapped product. Note that the weighing and conveying packaging device 100 does not necessarily have to have the printing section 102 and the adhesive section 103.

[0025] As shown in Figures 1 and 2, the control unit 7 is located on the upper part of the main body 100a. The control unit 7 controls various operations in the weighing and conveying packaging device 100. That is, the control unit 7 controls various operations in the weighing and conveying device 1 and various operations in the packaging unit 101, printing unit 102, and adhesive unit 103. The control unit 7 may control only the various operations in the weighing and conveying device 1, and the various operations of the packaging unit 101, printing unit 102, and adhesive unit 103 may be controlled by a control unit other than the control unit 7.

[0026] The control unit 7 consists of a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), all interconnected via bus lines such as an address bus and a data bus. The control unit 7 can be configured as software, for example, where a program stored in ROM is loaded onto RAM and executed by the CPU. The control unit 7 may also be configured as hardware, such as electronic circuits. In the control unit 7, the hardware, such as the CPU and main memory, and the software, such as a program, work together to form a switching unit 71 that switches the transport speed of the transport unit 3, and a transport control unit 72 that controls the transport of items by the transport unit 3.

[0027] The switching unit 71 accepts the switching of the transport speed via a transport speed switching screen (not shown) displayed on the display unit 5. On the transport speed switching screen, for example, any transport speed (in the first embodiment, "low speed", "medium speed", and "high speed") can be selected from a plurality of transport speeds that have been stored in advance. The selection of the transport speed is made via the input unit 6. The switching unit 71 stores the transport speed received in this way as a set value, for example, in RAM or the storage unit 8. The switching unit 71 may also be configured by a physical switching button or switch provided on the main unit 100a.

[0028] The transport control unit 72 initiates the transport of items by the transport unit 3 and controls the transport unit 3 according to the transport speed switched (set) by the switching unit 71. The transport control unit 72 executes control to initiate the transport of items in the transport unit 3 based on the upper limit weight corresponding to the transport speed switched by the switching unit 71 and the weight of the items measured by the weighing unit 2 (hereinafter also simply referred to as "transport start control"). The transport control unit 72 initiates the transport of items by the transport unit 3 if the weight of the items measured by the weighing unit 2 is less than or equal to the upper limit weight. The transport control unit 72 does not initiate the transport of items by the transport unit 3 if the weight of the items measured by the weighing unit 2 is greater than the upper limit weight. The transport control unit 72 may not initiate the transport of items by the transport unit 3 if the weight of the items measured by the weighing unit 2 is greater than or equal to the upper limit weight, and may initiate the transport of items by the transport unit 3 if the weight of the items measured by the weighing unit 2 is less than the upper limit. The upper limit weight corresponding to each of the multiple transport speeds is stored in the storage unit 8. Specifically, the upper weight limits corresponding to "high speed," "medium speed," and "low speed" are stored in the memory unit 8.

[0029] The maximum weight limit is defined for each conveying speed. The maximum weight limit is the weight of the item when the load current generated in the drive motor 32 when conveying the item at the corresponding conveying speed becomes the maximum allowable load current of the drive motor 32. As the conveying speed increases, the maximum weight limit decreases. In the first embodiment, the maximum weight limit when the conveying speed is "high" is, for example, 6.0 kg, the maximum weight limit when the conveying speed is "medium" is, for example, 6.5 kg, and the maximum weight limit when the conveying speed is "low" is, for example, 7.0 kg.

[0030] When the drive motor 32 of the transport unit 3 is operated to transport goods, a load current flows to the drive motor 32. The maximum allowable load current shown in Figure 3 is the maximum load current that flows when, for example, the user's hand caught in the transport unit 3 can resist being pulled into the inside of the device. In this case, the maximum allowable load current is set in a stepped manner to correspond to the changes in load current that occur during the transport of goods, but it may be set arbitrarily or legally as appropriate, taking into consideration the safety of the user. In addition, the maximum allowable load current corresponding to each of the multiple transport speeds is stored in the memory unit 8.

[0031] After the transport control unit 72 starts transporting the goods according to the transport start control described above, it executes a control to stop the transport of the goods based on the load current of the drive motor 32 and the allowable maximum load current. If the load current value measured by the load detection unit 4 becomes higher than the allowable maximum load current after the transport unit 3 has started transporting the goods, the transport control unit 72 executes a control to emergency stop the transport of goods by the transport unit 3 (hereinafter also simply referred to as "transport stop control").

[0032] In Figure 3, when the transport unit 3 transports an item, the load current is highest when it accelerates the stationary item to a predetermined transport speed (0~t1), then the load current decreases when it is transported at the predetermined transport speed for a while (t1~t2), and then the load current decreases further when it is decelerated to stop at the packaging unit 101 (t2~t3). Therefore, the maximum allowable load current is set in three stages as shown in Figure 3.

[0033] Specifically, in conventional transport stop control, the maximum allowable load current was set uniformly for the entire period (t:0~t3), with a current value A1. However, as mentioned above, the load current changes in stages according to the acceleration period, constant speed period, and deceleration period. Therefore, in this embodiment, in accordance with this trend, as shown in Figure 3, the maximum allowable load current during the period t:0~t1 is set to current value A1, the maximum allowable load current during the period t:t1~t2 is set to current value A2 which is smaller than current value A1, and the maximum allowable load current during the period t:t2~t3 is set to current value A3 which is smaller than current value A2. The transport stop control of the first embodiment is performed based on a pattern of current values ​​(first allowable load current) consisting of current values ​​A1, A2, and A3. The first allowable load current is stored in the memory unit 8, etc.

[0034] The display unit 5, for example, displays that the weight of the item is greater than the upper limit weight corresponding to the transport speed output from the switching unit 71.

[0035] Next, the operation of the weighing and conveying device 1 shown in Figure 4 will be explained. The user selects the conveying speed from the conveying speed switching screen displayed on the touch panel. For example, the user selects "high speed" as the conveying speed. The switching unit 71 accepts the input of the conveying speed via the user's operation of the touch panel (step S1). Subsequently, the user places an item on the weighing platform 21. The weighing unit 2 weighs the item (step S2). The weighing unit 2 outputs the measured weight of the item to the control unit 7. More specifically, the weighing unit 2 outputs the measured weight of the item to the conveying control unit 72.

[0036] Next, the transport control unit 72 determines whether or not to start transporting the item in the transport unit 3 based on the weight of the item weighed by the weighing unit 2 and the transport speed switched by the switching unit 71 (step S3). If the weight of the item weighed by the weighing unit 2 is greater than the upper limit weight corresponding to the transport speed switched by the switching unit 71 (step S3: NO), the transport control unit 72 does not start transporting the item in the transport unit 3. More specifically, if the weight of the item weighed by the weighing unit 2 is greater than the upper limit weight (6.0 kg) corresponding to the "high speed" transport speed switched by the switching unit 71, the transport control unit 72 does not start transporting the item in the transport unit 3.

[0037] Next, the display unit 5 displays a warning message (step S4). As shown in Figure 5, the display unit 5 displays a packaging weight limit error as a message. The packaging weight limit error includes information on the operating conditions for safely transporting the goods to the transport unit 3. Operating conditions for safely transporting the goods to the transport unit 3 include, for example, adjusting the weight of the goods so that the weight of the goods is less than or equal to the upper limit weight, and slowing down the transport speed. In the example shown in Figure 5, the user is instructed to adjust the weight of the goods so that the weight of the goods is 6.0 kg or less, and to set the transport speed to "medium speed" or lower.

[0038] After the display unit 5 displays a warning message, the switching unit 71 accepts input of the transport speed via the user's touch panel operation (step S1). This allows the user to select a transport speed slower than the previously selected transport speed. If the user switches to a transport speed slower than the previously selected transport speed without reducing the weight of the items placed on the weighing platform 21, steps S1 to S4 are repeated until the upper limit weight corresponding to the switched transport speed is equal to or greater than the weight of the items weighed by the weighing unit 2.

[0039] If, after step S4, the weight of the item placed on the weighing platform 21 is reduced, the switching unit 71 may perform step S2 without accepting input of the transport speed via the user's touch panel operation. When the weight of the item re-weighed by the weighing unit 2 is less than or equal to the upper limit weight, the transport control unit 72 starts transporting the item by the transport unit 3.

[0040] When the weight of the item re-weighed by the weighing unit 2 is less than or equal to the upper limit weight corresponding to the transport speed (step S3: YES), the transport control unit 72 causes the transport unit 3 to start transporting (step S5). The transport control unit 72 drives the drive motor 32 based on the transport speed switched by the switching unit 71. Next, the transport control unit 72 determines whether the current flowing to the drive motor 32 is less than or equal to the first allowable load current (step S6). The load detection unit 4 constantly monitors the load current during the period when the transport unit 3 is transporting the item from the weighing platform 21 to the packaging unit 101, and outputs the monitoring results to the transport control unit 72. The transport control unit 72 determines whether the load current detected by the load detection unit 4 at time t is less than or equal to the first allowable load current at time t.

[0041] On the other hand, if the transport control unit 72 determines that the load current output from the load detection unit 4 is greater than the first allowable load current (step S6: NO), the transport control unit 72 will emergency stop the drive motor 32 (step S7).

[0042] If the transport control unit 72 determines that the load current output from the load detection unit 4 is less than or equal to the first allowable load current (step S6: YES), the transport control unit 72 determines whether or not the article has arrived at the packaging unit 101 (step S8). If the transport control unit 72 determines that the article has not arrived at the packaging unit 101 (step S8: NO), the transport control unit 72 causes the transport unit 3 to continue transporting the article until the article arrives at the packaging unit 101.

[0043] When the transport control unit 72 determines that an item has arrived at the packaging unit 101 (step S8: YES), the transport control unit 72 terminates the transport of the item to the transport unit 3 (step S9). In the weighing and transport packaging device 100, the packaging unit 101 wraps the item that has arrived at the packaging unit 101 with film and discharges it, and during this time, the printing unit 102 issues a product label based on information about the discharged product, and when the packaged product is being discharged to the sealing mechanism 115, the adhesive unit 103 affixes the product label onto the film of the packaged product.

[0044] The effects of the weighing and conveying device 1 and the weighing and conveying packaging device 100 in the first embodiment described above will now be explained. In the weighing and conveying device 1 of the first embodiment, different upper weight limits are stored for different conveying speeds. Even if the weight of an item exceeds one upper weight limit, the conveying speed can be switched to set a different upper weight limit. If the other upper weight limit set when the conveying speed is switched is equal to or greater than the weight of the item weighed by the weighing unit 2, the conveying control unit 72 starts conveying the item in the conveying unit 3. This ensures safety by not starting conveying when the weight of the item exceeds the upper weight limit, while also widening the range of weights of items that the conveying unit 3 can convey.

[0045] In the weighing and conveying device 1 of the first embodiment described above, the switching unit 71 can be switched to "high speed," "medium speed," and "low speed" as conveying speeds, and the upper limit weight corresponding to "medium speed" is greater than the upper limit weight corresponding to "high speed." The upper limit weight corresponding to "low speed" is greater than the upper limit weight corresponding to "medium speed." With this configuration, even if the weight of the item exceeds the upper limit weight corresponding to "high speed," the item can be conveyed by switching to "medium speed" or "low speed," which correspond to an upper limit weight greater than the upper limit weight corresponding to "high speed."

[0046] In the weighing and conveying device 1 of the first embodiment described above, a display unit 5 is further provided that displays a message announcing that the weight of the item is greater than the upper limit weight corresponding to the conveying speed, for example, as shown in Figure 5. With this configuration, the user can recognize that the weight of the item is greater than the upper limit weight via the display unit 5, and can take appropriate action, such as switching the conveying speed. This makes the weighing and conveying device 1 even safer to operate.

[0047] In the weighing, conveying, and packaging device 100 of the first embodiment described above, the conveying unit 3 can wrap the conveyed articles with film.

[0048] Next, a weighing and conveying packaging apparatus 100 including a weighing and conveying device 1 according to a second embodiment relating to one aspect of the present invention will be described in detail. In addition to the configuration of the weighing and conveying packaging apparatus 100 including the weighing and conveying device 1 of the first embodiment, the control unit 7 further includes a selection unit 73 that selects a first mode or a second mode through the cooperation of hardware such as a CPU and main memory unit and software such as a program. In Figure 2, the selection unit 73 is shown with a dashed line, meaning that the selection unit 73 is not included in the first embodiment, but is included in the second embodiment.

[0049] The selection unit 73, similar to the switching unit 71 in the first embodiment, accepts the selection of either the first mode or the second mode via a mode switching screen (not shown) displayed on the display unit 5. The selection of the first mode or the second mode is made via the input unit 6. The selection unit 73 stores the received selection of the first mode or the second mode in, for example, RAM or storage unit 8. The selection unit 73 may also be configured by a physical mode switching button or switch provided on the main unit 100a.

[0050] When the first mode is selected by the selection unit 73, the transport control unit 72 executes control to start transporting the items in the transport unit 3 based on the upper limit weight corresponding to the transport speed switched by the switching unit 71. The transport control unit 72 also executes control to stop transporting the items based on the load current of the drive motor 32 and the first allowable load current stored in the storage unit 8. In other words, the first mode is the mode realized by the configuration of the first embodiment described above. For this reason, a detailed explanation of the first mode is omitted.

[0051] When the second mode is selected by the selection unit 73, the transport control unit 72 executes control to start transporting the items in the transport unit 3 based on one upper weight limit stored in the memory unit 8, regardless of the transport speed switched by the switching unit 71. Regardless of the transport speed switched by the switching unit 71, the transport control unit 72 executes control to start transporting the items in the transport unit 3 based on, for example, the upper weight limit (e.g., 6.0 kg) when "high speed" is selected in the switching unit 71 of the first embodiment. In the first embodiment, when an item weighing 6.0 kg or more is placed on the weighing platform 21, transport does not start at the "high speed" transport speed, but transport starts when the transport speed is switched to "medium speed". However, in the second embodiment, even if the transport speed is switched to "medium speed", transport of items weighing more than 6 kg will not start.

[0052] Furthermore, when the second mode is selected by the selection unit 73, the transport control unit 72 executes control to stop the transport of the goods based on the load current of the drive motor 32 and the second allowable load current stored in the storage unit 8 for each transport speed switched by the switching unit 71. The second allowable load current is stored in the storage unit 8.

[0053] As shown in Figure 6, the second allowable load current is the allowable load current TH corresponding to the transport speed "high speed". H And the allowable load current TH corresponding to the transport speed "medium speed" M And the allowable load current TH corresponding to the transport speed "low speed" LIt includes the following. Note that t11, t12, and t13 of time t shown in FIG. 6 match t1, t2, and t3 shown in FIG. 3.

[0054] Specifically, the allowable load current TH during the period when time t is from 0 to t11 H , TH M , TH L is the current value A4, and the values of the allowable load current TH H , TH M , TH L are equal to each other. This current value A4 may be the same as the current value A1 (the allowable maximum load current when the conveyance speed corresponds to "high speed") in the first embodiment (see FIG. 3). The allowable load current TH during the period when time t is from t11 to t12 H , TH M , TH L becomes a value smaller than the current value A1. Specifically, the allowable load current TH during the period when time t is from t11 to t12 H is the current value A5. The allowable load current TH during the period when time t is from t12 to t13 H is the current value A8 smaller than the current value A5. The allowable load current TH during the period when time t is from t11 to t12 M is the current value A6 smaller than the current value A5. The allowable load current TH during the period when time t is from t11 to t12 L is the current value A7 smaller than the current value A6. Note that the above allowable load current TH H, TH M , TH L has been described by taking an example where the current value is set to decrease step by step, but appropriate settings such as the current value increasing midway are possible.

[0055] The operation of the weighing and conveying device 1 when the first mode is selected is the same as the operation of the weighing and conveying device 1 described in the first embodiment, so it will be omitted. Next, the operation of the weighing and conveying device 1 when the second mode is selected will be explained mainly with reference to Figure 7. The user selects the conveying speed from the conveying speed switching screen displayed on the touch panel. The switching unit 71 accepts the conveying speed input via the user's operation of the touch panel (step S11). Next, the user places an item on the weighing platform 21. The weighing unit 2 weighs the weight of the item (step S12). The weighing unit 2 outputs the weighing value, which is the weight of the item, to the control unit 7. More specifically, the weighing unit 2 outputs the weighing value, which is the weight of the item, to the conveying control unit 72.

[0056] Next, the transport control unit 72 determines whether to start transporting the items to the transport unit 3 based on one upper weight limit stored in the memory unit 8, regardless of the transport speed switched by the switching unit 71 (step S13). If the weight of the items weighed by the weighing unit 2 is greater than the upper weight limit (step S13: NO), the transport control unit 72 does not start transporting the items to the transport unit 3.

[0057] Next, the display unit 5 displays a warning message (step S14). The display unit 5 displays a packaging weight limit error as a message. The packaging weight limit error includes information on the operating conditions for safely transporting the goods to the transport unit 3. Operating conditions for safely transporting the goods to the transport unit 3 include, for example, adjusting the weight of the goods so that the weight of the goods is less than or equal to the upper limit weight.

[0058] The user places an item that is lighter in weight than the previous item. When the weight of the item re-weighed by the weighing unit 2 is less than or equal to the upper limit weight (step S13: YES), the transport control unit 72 causes the transport unit 3 to start transporting (step S15). The transport control unit 72 drives the drive motor 32 based on the transport speed switched by the switching unit 71. Next, the transport control unit 72 determines whether the load current flowing to the drive motor 32 is less than or equal to the second allowable load current (step S16). The load detection unit 4 constantly monitors the load current during the period when the transport unit 3 is transporting the item from the weighing platform 21 to the packaging unit 101, and outputs the monitoring results to the transport control unit 72. The transport control unit 72 determines whether the load current detected by the load detection unit 4 at time t is less than or equal to the second allowable load current at time t.

[0059] The transport control unit 72 compares the load current with one of the multiple allowable load currents included in the second allowable load current. Which of the second allowable load currents to adopt is determined by the transport speed input to the input unit 6. If the transport speed input to the input unit 6 is "high speed", the transport control unit 72 adopts the allowable load current TH H When this is adopted and the transport speed input to the input unit 6 is "medium speed", the transport control unit 72 sets the allowable load current TH M When the transport speed input to the input unit 6 is "low speed", the transport control unit 72 sets the allowable load current TH L We will adopt this.

[0060] On the other hand, if the transport control unit 72 determines that the load current output from the load detection unit 4 is greater than the second allowable load current (step S16: NO), the transport control unit 72 will perform an emergency stop on the drive motor 32 (step S17).

[0061] If the transport control unit 72 determines that the load current output from the load detection unit 4 is less than or equal to the second allowable load current (step S16: YES), the transport control unit 72 determines whether or not the product has arrived at the packaging unit 101 (step S18). If the transport control unit 72 determines that the product has not arrived at the packaging unit 101 (step S18: NO), the transport control unit 72 causes the transport unit 3 to continue transporting the product until the product arrives at the packaging unit 101.

[0062] If the transport control unit 72 determines that the product has arrived at the packaging unit 101 (step S18: YES), the transport control unit 72 instructs the transport unit 3 to terminate the transport of the product (step S19). The explanation from step S19 onward is the same as in the first embodiment, so a detailed explanation is omitted here.

[0063] According to the weighing and conveying device of the second embodiment, it is possible to select between a first mode, in which heavier goods can be conveyed by slowing down the conveying speed, and a second mode, in which, although it is not possible to convey heavier items even if the conveying speed is slowed, safety during the conveying of items is enhanced. As a result, by appropriately selecting the mode, the specifications of a single weighing and conveying device can be switched to specifications that prioritize productivity or specifications that prioritize safety.

[0064] Although the first and second embodiments have been described above, one aspect of the present invention is not limited to the first and second embodiments. Various modifications are possible without departing from the spirit of the invention.

[0065] Next, a modified weighing and conveying device will be described. In the modified weighing and conveying device, the switching unit 71 switches to a conveying speed corresponding to an upper limit weight greater than the weight of the item when the weight of the item weighed by the weighing unit 2 is greater than the upper limit weight corresponding to the conveying speed. The operation of the modified weighing and conveying device shown in Figure 8 will be described. After performing the steps S1, S2, and S3 described above, if the weighed value corresponding to the weight of the item weighed by the weighing unit 2 is greater than the upper limit weight corresponding to the conveying speed switched by the switching unit 71 (step S3: NO), the switching unit 71 automatically switches the conveying speed (step S4A).

[0066] Next, step S2 described above is performed. The switching unit 71 may extract a transport speed one step slower than the transport speed output to the transport control unit 72 from among the multiple transport speeds stored in the storage unit 8 and output it to the transport control unit 72, or it may extract a transport speed corresponding to an upper limit weight that exceeds the weight of the item weighed by the weighing unit 2 and output it to the transport control unit 72. When the weight of the item is less than the upper limit weight corresponding to the transport speed (step S3: YES), steps S5, S6, S7, S8, and S9 are performed sequentially as shown in Figure 4.

[0067] In this configuration, items are transported at a transport speed that corresponds to a maximum weight exceeding the actual weight of the items, allowing for quick and safe transport of goods.

[0068] The display unit 5 may display a warning message that includes information regarding the difference (weight difference) between the weight of the item weighed by the weighing unit 2 and the upper weight limit. The display unit 5 may also display a warning message that includes information regarding the transport speed corresponding to the upper weight limit that exceeds the weight of the item weighed by the weighing unit 2. Specifically, when the transport speed is set to "high speed," if the upper weight limit corresponding to "medium speed" does not exceed the weight of the item weighed by the weighing unit 2, but the upper weight limit corresponding to "low speed" exceeds the weight of the item weighed by the weighing unit 2, the display unit 5 may display a warning message that recommends setting the transport speed to "low speed." [Explanation of symbols]

[0069] 1...Weighing and conveying device, 2...Weighing unit, 3...Conveying unit, 5...Display unit, 8...Storage unit, 32...Drive motor, 71...Switching unit, 72...Conveying control unit, 100...Weighing, conveying, and packaging device, 101...Packaging unit.

Claims

1. A weighing unit for weighing items, A conveying unit that transports the article weighed by the weighing unit by operating a drive motor, A transport control unit that initiates the transport of the article by the transport unit when the weight of the article measured by the weighing unit is less than or equal to the upper limit weight, A switching unit for switching the transport speed of the transport unit, A storage unit that stores the upper limit weight for each of the transport speeds switched by the switching unit, A weighing and conveying device in which each of the upper weight limits stored in the memory unit is the weight of the item when the load current generated in the drive motor when the item is conveyed at the corresponding conveying speed becomes the maximum allowable load current of the drive motor.

2. The switching unit is capable of switching between a first transport speed and a second transport speed that is slower than the first transport speed. The first upper limit weight corresponding to the first transport speed is the weight at which the load current of the drive motor generated when transporting the article at the first transport speed becomes the maximum allowable load current of the drive motor. The weighing and conveying device according to claim 1, wherein the second upper limit weight corresponding to the second conveying speed is greater than the first upper limit weight, and is the weight at which the load current of the drive motor generated when conveying the article at the second conveying speed becomes the maximum allowable load current of the drive motor.

3. The weighing and conveying device according to claim 1 or claim 2, further comprising a display unit that indicates that the weight of the article is greater than the upper limit weight corresponding to the conveying speed.

4. The weighing and conveying device according to claim 1 or 2, wherein the switching unit switches to the conveying speed corresponding to the upper limit weight which is greater than the weight of the article when the weight of the article weighed by the weighing unit is greater than the upper limit weight which is greater than the conveying speed.

5. It further includes a selection unit for selecting either the first mode or the second mode. When the first mode is selected by the selection unit, the transport control unit executes control to start transporting the article in the transport unit based on the upper limit weight corresponding to the transport speed switched by the switching unit and the weight of the article, and also executes control to stop transporting the article based on the load current of the drive motor and the first allowable load current stored in the storage unit. When the second mode is selected by the selection unit, the transport control unit executes control to start transporting the article in the transport unit based on one upper limit weight stored in the storage unit, regardless of the transport speed switched by the switching unit, and executes control to stop transporting the article based on the load current of the drive motor and a second allowable load current stored in the storage unit for each transport speed, as described in claim 1 or 2.

6. A weighing and conveying device according to claim 1 or claim 2, The system comprises a packaging section located downstream of the conveying section, The packaging unit is a weighing, conveying, and packaging device that wraps the article in film and discharges it.

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