JP2022139547A - Combination weigher, and control method of combination weigher - Google Patents

Abstract

To provide a combination weigher capable of improving productivity.SOLUTION: A combination weigher in an embodiment includes: conveyor 3; a combination processing unit 51 that finds the discharge combination including multiple weighing object holders and weighing object holder for the object to be weighed whose total weight is within the target weight range, in which the total weight of the objects to be weighed is within the target weight range; a timing derivation unit 52 that obtains start timing of an ejection operation of each weighing object holder so that the objects to be weighed discharged from each weighing object holder of the discharge combination are positioned at a same position on the transport conveyor 3; an operation control unit 53 that is configured to control the conveyor 3 to start a conveying operation and the weighing object holder to start the discharging operation based on the start timing each time a discharge request signal is input from the downstream device 50, and after starting conveyor 3, to control the conveyor 3 to terminate the conveying operation so that the objects to be weighed discharged from the weighing object holder stop at a conveying termination area of the conveyor 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a combination weigher that combines and discharges objects whose total weight is within a predetermined target weight range, and a control method for the combination weigher.

In a combination weigher, for example, the weight of each of a plurality of objects to be weighed is weighed, and a combination calculation is performed using the weight values of the weighed objects, and the total weight of the objects to be weighed is within a predetermined target weight range. is configured to emit

Patent Documents 1 and 2 disclose a plurality of weighing conveyors for weighing objects to be weighed, a plurality of supply conveyors for supplying the objects to be weighed to each of the weighing conveyors, and the objects to be weighed discharged from each of the weighing conveyors. and a single conveyor (collective conveyor) for conveying and discharging to a post-stage device such as a packaging machine. In this combination weigher, after inputting a discharge request signal (discharge command signal) from a subsequent device, the objects to be weighed whose total weight is within the target weight range are discharged from a plurality of weighing conveyors to the transfer conveyor, and the transfer conveyor conveys the object to be weighed and discharges it to the subsequent device.

JP 2013-120121 A JP 2013-120122 A

In the configurations of Patent Literatures 1 and 2, the objects to be weighed are discharged from a plurality of weighing conveyors, and the transport conveyor is used to discharge the objects to be weighed from a plurality of weighing conveyors until the objects to be weighed are discharged to the latter device after a discharge request signal is input from the latter device. must be transported by As a result, the time from the input of the discharge request signal to the discharge of the object to be weighed to the subsequent device becomes longer, and there is room for improvement in terms of improving productivity (processing capacity).

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a combination weigher and a control method for the combination weigher that can improve productivity.

In order to achieve the above object, a combination weigher according to an aspect of the present invention includes a conveyor that conveys the objects to be weighed in one direction and discharges them to a subsequent device, and temporarily holds the supplied objects to be weighed. a plurality of holding parts for the objects to be weighed, which supply the objects to be weighed to the conveyor by discharging them from discharge ports, and each of the discharge ports is arranged at a predetermined position with respect to the conveying direction of the conveyor; a combination processing unit that repeatedly performs a combination process for obtaining one discharge combination consisting of a combination of said object holding parts whose total weight of the held objects to be weighed is within a target weight range; Each time a discharge combination is obtained, each of the objects selected for the discharge combination is determined based on the positions of the discharge ports of the holding portions of the objects to be weighed selected for the discharge combination and the conveying speed of the conveyor. a timing derivation unit for determining the start timing of the discharging operation of each of the object holding units so that the objects to be weighed discharged from the object holding units are positioned at the same position on the conveyer; each time a discharge request signal is input, the conveyer is caused to start a carrying operation, and the object holding unit is caused to start a discharging operation based on the start timing obtained by the timing derivation unit; After causing the conveyer to start the conveying operation, the conveyer conveys the object to be weighed discharged from the object-to-be-weighed holding portion and stops the object to be weighed in the conveying end region of the conveyer. and an operation control unit for ending the conveying operation.

According to this configuration, the objects to be weighed discharged from the respective holding units for the objects to be weighed selected as the discharge combination are conveyed so as to be positioned (collected) at the same position on the conveyer, and conveyed by the conveyer. It is made to stop in the state where it gathered in the end region. As a result, when a discharge request signal is input from the post-stage device, the objects to be weighed can be discharged to the post-stage device immediately, and the objects to be weighed can be discharged together. Therefore, it is possible to shorten the time from inputting the discharge request signal from the subsequent device to discharging the object to be weighed to the latter device, thereby improving productivity.

In this specification and the scope of claims, the conveying end area of the conveyer means a predetermined conveying end of the conveyer and a predetermined area in the vicinity thereof.

Each time the discharge combination is obtained by the combination processing, the timing deriving section selects the object to be weighed that is positioned most upstream in the conveying direction of the conveyer among the object-to-be-weighed holding units selected for the discharge combination. Based on the position of the discharge port of the object holding part, the conveying conveyor is arranged so that the object to be weighed discharged from the object holding part and conveyed by the conveying conveyor stops at a transfer end region of the conveying conveyor. and the operation control unit causes the conveyer to start the conveying operation, and then causes the conveyer to finish the conveying operation based on the end timing obtained by the timing deriving unit. may be configured as follows.

It further comprises an object-to-be-weighed detection unit that detects an object to be weighed existing in a conveying end area of the conveyer, and the operation control unit detects that the object to be weighed is detected by the object to be weighed while causing the conveyer to carry out a conveying operation. The transport conveyor may be configured to end the transport operation when the object is newly detected by the weighing object detection unit.

A collection hopper is further provided for accommodating and temporarily holding the objects to be weighed discharged from the discharge end of the conveyer and discharging them to the post-stage device, wherein the operation control unit receives a discharge request signal from the post-stage device. , the objects to be weighed may be immediately discharged from the collecting hopper.

According to this configuration, since the objects to be weighed are discharged from the collection hopper in a more collected state, it becomes easier to coordinate the operation with the subsequent device. In this case, upon receiving a discharge request signal from the post-stage device, the operation control section can immediately discharge the collected objects from the collecting hopper to the post-stage device. time) can be shortened, and productivity can be further improved.

The carrying-out end of the conveyer is further provided with a route opening/closing unit that switches between closing and opening of the discharge route of the objects to be weighed, and the route opening/closing unit is operated for a period from the start of the conveying operation of the conveyer until a predetermined time elapses. opens the discharge path to enable discharge of the objects to be weighed from the conveyer, and closes the discharge path to prevent discharge of the objects to be weighed from the conveyer during periods other than the period. may be configured as follows.

By providing such a path opening/closing unit, for example, even if the object to be weighed is an object that rolls easily, when the conveying operation of the conveyer is finished (stopped), the object to be weighed does not move from the carry-out end of the conveyer. Dropping can be prevented, and the objects to be weighed can be reliably stopped in the transfer terminal area of the transfer conveyor.

The object-to-be-weighed holding unit is supplied with an object to be weighed when the conveyance is stopped, temporarily holds the supplied object to be weighed, weighs the supplied object to be weighed, and transports the held object for a predetermined time to It may be configured with a weighing conveyor that discharges to a transport conveyor.

Further, a method for controlling a combination weigher according to an aspect of the present invention includes a conveyor that conveys objects to be weighed in one direction and discharges them to a subsequent device, temporarily holds the objects to be weighed that are supplied, and then discharges them from a discharge port. a plurality of holding parts for the objects to be weighed that supply the objects to be weighed to the conveyer by discharging them, and each of the discharge ports is arranged at a predetermined position with respect to the conveying direction of the conveyer. 2. A control method for a combination weigher, comprising repeating a combination process for obtaining one discharge combination consisting of a combination of said object holding units in which the total weight of the held objects to be weighed is within a target weight range, Each time the discharge combination is obtained by the combination processing, the discharge combination is selected based on the position of the discharge port of the object holding unit selected for the discharge combination and the conveying speed of the conveyer. a timing derivation process for obtaining a start timing of the discharging operation of each of the object-to-be-weighed holding units so that the objects to be weighed ejected from the object-to-be-weighed holding units are positioned at the same position on the conveyor; every time a discharge request signal is input from the post-stage device, the conveyer is caused to start the conveying operation, and the object-to-be-weighed holding section starts the discharging operation based on the start timing obtained in the timing derivation process. Further, after starting the transport operation of the transport conveyor, the object to be weighed discharged from the object holding part to be weighed is transported, and the object to be weighed stops in the transport end region of the transport conveyor. An operation control process is performed to terminate the conveying operation of the conveyer so as to perform the conveying operation.

According to this control method, the objects to be weighed discharged from the respective holding parts for the objects to be weighed selected for the discharge combination are conveyed so as to be positioned (collected) at the same position on the conveyor, It is made to stop in the state which gathered in the conveyance end area|region. As a result, when a discharge request signal is input from the post-stage device, the objects to be weighed can be discharged to the post-stage device immediately, and the objects to be weighed can be discharged together. Therefore, it is possible to shorten the time from inputting the discharge request signal from the subsequent device to discharging the object to be weighed to the latter device, thereby improving productivity.

ADVANTAGE OF THE INVENTION This invention has the structure demonstrated above, and is effective in the ability to provide the combination weigher which can improve productivity, and the control method of a combination weigher.

FIG. 1(A) is a schematic plan view of a combination weigher as an example of the present embodiment viewed from above, and FIG. 1(B) is a schematic diagram showing the main parts of the combination weigher when viewed from the side. is. 2 is a block diagram showing a schematic configuration of the combination weigher shown in FIG. 1. FIG. FIG. 3 is a schematic diagram showing the arrangement of weighing conveyors and transport conveyors used for explaining the operation of the combination weigher shown in FIG. 4 is a flow chart showing an example of the operation of the combination weigher shown in FIG. 1. FIG. FIG. 5 is a diagram showing a main part of a modification of this embodiment.

Preferred embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals are given to the same or corresponding elements throughout all the drawings, and duplicate descriptions thereof will be omitted. Moreover, the present invention is not limited to the following embodiments. Also, the numerical values exemplified below are examples, and the present invention is not limited to these numerical values.

(embodiment)
FIG. 1(A) is a schematic plan view of a combination weigher as an example of the present embodiment viewed from above, and FIG. 1 is a schematic diagram showing a transport conveyor). FIG. 2 is a block diagram showing a schematic configuration of the combination weigher shown in FIG. 1. As shown in FIG.

This combination weigher includes a plurality of (for example, 12) weighing units Cw, a conveyer 3, an operation display 4, a control device 5, and the like.

A conveyer 3 is arranged substantially in the center, and six weighing units Cw are arranged on both sides of the conveyer 3 . Each weighing unit Cw is composed of a weighing conveyor 1, which is a belt conveyor supported by a weight sensor 2 such as a load cell. Here, a group of six weighing units Cw on one side of the conveyor 3 will be referred to as a weighing group G1, and a group of six weighing units Cw on the other side will be referred to as a weighing group G2.

The six weighing conveyors 1 of the weighing section Cw of the weighing group G1 are arranged in parallel on one side of the transport conveyor 3. direction c)). Also, the six weighing conveyors 1 of the weighing section Cw of the weighing group G2 are arranged in parallel on the other side of the transport conveyor 3, and the transport direction of each of them (the direction of arrow b) is the transport direction of the transport conveyor 3. are arranged so as to cross (perpendicularly in this example) the .

The transport conveyor 3 is composed of a belt conveyor, and transports the objects to be weighed discharged from each weighing conveyor 1, for example, in the direction of arrow c. A post-stage device 50 following the combination weigher is installed at the transport destination, and the objects to be weighed transported by the transport conveyor 3 are supplied to the post-stage device 50 . In the example of FIG. 1, a funnel 21 is provided near the unloading end 3a of the conveyer 3, and the objects to be weighed unloaded from the conveyer 3 pass through the lower outlet 21a of the funnel 21 to the post-stage device 50. supplied.

Each of the weighing conveyor 1 and the transporting conveyor 3 may be provided with a pair of guide plates (not shown) on both sides so that the transported objects to be weighed do not drop from both sides.

Further, the device body 15 is mounted on a frame (not shown), and the weighing conveyor 1, the transfer conveyor 3, and the like are mounted on the device body 15. As shown in FIG. The apparatus main body 15 accommodates the conveyor drive circuits 8a and 8b, the A/D converter 9, the controller 5, the I/O circuit 12, and the like shown in FIG.

In each weighing unit Cw, the weight sensor 2 measures the weight of the object to be weighed on the weighing conveyor 1, and the weighed value (analog weight signal) is converted into a digital signal by the A/D converter 9 and controlled. It is sent to the device 5.

The control device 5 is configured by, for example, a microcontroller or the like, and has an arithmetic control section 6 made up of a CPU or the like, and a storage section 7 made up of memories such as RAM and ROM. The storage unit 7 stores an operating program, operation parameter data, weighing data, and the like. The control device 5 has a timer function and functions as a combination processing section 51, a timing derivation section 52, an operation control section 53, and the like. Note that the control device 5 may be configured by a single control device that performs centralized control, or may be configured by a plurality of control devices that cooperate with each other to perform distributed control.

The control device 5 controls the entire combination weigher and performs combination processing, etc., which will be described later, by executing the operation program stored in the storage unit 7 by the arithmetic control unit 6 . For example, the weight value measured by each weight sensor 2 is acquired as a digital value via the A/D converter 9 at any time, and stored in the storage unit 7 if necessary. Further, the control device 5 controls the conveying operation of each of the weighing conveyors 1 and the conveying conveyor 3 through the conveyor drive circuit units 8a and 8b. The control device 5 is also capable of exchanging signals with the post-stage device 50 via the I/O circuit section 12. In this example, a discharge request signal is input from the post-stage device 50 and discharged to the post-stage device 50. Output a notification signal. The control device 5 also receives signals from the operation display 4 and outputs signals such as data to be displayed on the operation display 4 . Note that the A/D conversion section 9 and the I/O circuit section 12 may be included in the control device 5 .

The operation display device 4 includes, for example, a touch screen display (display device), and on the screen of this display, operations such as starting and stopping of operation of the combination weigher, setting of operation parameters, etc. can be performed. The result of the combination processing by the control device 5 (combination weight, etc.) can be displayed on the display screen.

The post-stage device 50 outputs a discharge request signal to the combination weigher (control device 5) when preparations for receiving the objects to be weighed are completed or at a predetermined timing immediately before that. Further, when a discharge notification signal is input from the combination weigher (control device 5), a predetermined operation is started based on the input timing. As the post-stage device 50, for example, a bag feeding type packaging machine for packing the objects to be weighed into bags may be arranged. Further, as the post-stage device 50, for example, a tray conveying device that intermittently horizontally moves a plurality of trays (shallow boxes) connected in a ring may be arranged.

The funnel 21 shown in FIG. 1(A) accurately places the objects to be weighed discharged from the carry-out end 3a of the conveyor 3 onto a bag (in the case of a packaging machine) or a tray (in the case of a tray conveying device) of the post-stage device 50. provided to allow entry. The objects to be weighed discharged from the conveyer 3 pass through the lower outlet 21a of the funnel 21 and are placed in bags or trays.

Next, an example of the operation of the combination weigher of this embodiment will be described.
In this embodiment, the operator performs the task of supplying (placing) the object to be weighed to the weighing conveyor 1 on which the object to be weighed is not placed while the transport is stopped. Here, the object to be weighed that is supplied to each weighing conveyor 1 at one time may be composed of one item or may be composed of a plurality of items. The object to be weighed is, for example, agricultural products or marine products.

The control device 5 acquires the weighed value of each weight sensor 2 from the A/D converter 9 at regular time intervals, and recognizes the weighing conveyor 1 to which the objects to be weighed are supplied based on the weighed value of the weight sensor 2. and the weight value of the object to be weighed. Here, when recognizing the weighing conveyor 1 to which the objects to be weighed are supplied, the weighing value (weight value) is compared with a preset load detection reference value (for example, 6 g), and the weighing value is the load detection reference value. If it is equal to or above, it is determined that the object to be weighed is supplied, and if it is less than the load detection reference value, it is determined that the object to be weighed is not supplied.

Here, the combination processing by the control device 5 (combination processing section 51) will be described. In this combination processing, a combination calculation is performed based on the weight of the objects to be weighed on each weighing conveyor 1 obtained from the weight values of the weight sensors 2, and the total weight (combination weight) of the objects to be weighed being supplied is a predetermined value. All combinations of the weighing conveyors 1 within the target weight range (allowable range for the target weight) are obtained, and one combination is determined as the discharge combination. Here, if there are a plurality of combinations within the target weight range, for example, the combination having the smallest absolute value of the difference between the combination weight and the target weight is determined as the discharge combination. Although the details will be described later, the objects to be weighed on the weighing conveyor 1 selected for the discharge combination by the combining process are transported by the weighing conveyor 1 and discharged onto the transport conveyor 3 from the carry-out end 1a. In this embodiment, each weighing conveyor 1 is an object-to-be-weighed holding portion, and its carry-out end 1a is the discharge port of the object-to-be-weighed holding portion.

FIG. 3 is a schematic diagram showing the arrangement of the weighing conveyor 1 and the transfer conveyor 3 used for explaining the operation of the combination weigher shown in FIG.

In this embodiment, it is assumed that the work manual or the like stipulates that the position at which an operator places an object to be weighed on each weighing conveyor 1 is, for example, the middle position of the weighing conveyor 1 in the machine length direction. The conveying speed of all the weighing conveyors 1 is set to be the same. The required time is assumed to be the same. Therefore, the relationship between the timing of discharging the objects to be weighed from the carry-out end 1a of each weighing conveyor 1 to the transport conveyor 3 (the order of discharge of each weighing conveyor 1 and the discharge time interval) and the start of the transport operation of each weighing conveyor 1 The relationship in timing (the order of starting the conveying operation of each weighing conveyor 1 and the start time interval of the conveying operation) is the same.

As shown in parentheses in FIG. 3, each weighing conveyor 1 is assigned a conveyor number in order from the side closer to the discharge end 3a of the transporting conveyor 3, and the conveyor number for each weighing conveyor 1 is stored. stored in section 7. In addition, regarding the weighing conveyors 1 which are located at the same position in the conveying direction of the conveying conveyor 3 and are opposed to each other with the conveying conveyor 3 interposed therebetween, one of them is given a smaller conveyor number, and the other is given the next conveyor number. attached. In addition, L is the center-to-center distance between the weighing conveyors 1 adjacent in the machine length direction (conveying direction) of the transport conveyor 3, and L is the distance from the carry-out end 3a of the carry-out end 3a to the center of the weighing conveyor 1 closest to this carry-out end 3a. Let P.

In FIG. 3, the objects to be weighed discharged from the weighing conveyor 1 with the conveyor number (k) are shown as Mk (k=1 to 12). For example, M12 is the object to be weighed discharged from the weighing conveyor 1 with the conveyor number (12). 3 indicates the position of the unloading end 1a (the center position of the unloading end 1a), which is the discharge port of the weighing conveyor 1, in the transport direction of the transport conveyor 3. As shown in FIG. In FIG. 3, the position of the unloading end 1a of the weighing conveyor 1 with the conveyor numbers (1) and (2) is set to 0, and the value of the position increases toward the upstream side of the conveyor 3. is exemplified, but is not limited to this. The controller 5 stores the “conveyance position” of each weighing conveyor 1 in advance in the storage unit 7 .

In this embodiment, the control device 5 selects the discharge combination so that the objects to be weighed discharged from the weighing conveyors 1 selected for the discharge combination are positioned at the same position on the transport conveyor 3 and conveyed. The start timing of the carrying operation of each of the weighing conveyors 1 is obtained, and each weighing conveyor 1 is caused to start the carrying operation based on the start timing. Therefore, in the plurality of weighing conveyors 1 selected for the discharge combination, the objects to be weighed are discharged in order from the weighing conveyor 1 closer to the upstream end 3b in the conveying direction of the transporting conveyor 3 .

In FIG. 3, for example, four weighing conveyors 1 with conveyor numbers (3), (4), (7), and (12) are selected as a discharge combination, and the objects to be weighed M3 and M3 discharged from these weighing conveyors 1 are selected. The transfer state of M4, M7 and M12 on the transfer conveyor 3 is shown. In this case, when the conveying operation of the conveyer 3 is started, first, the object to be weighed M12 is discharged from the weighing conveyor 1 with the conveyor number (12), and the object to be weighed M12 is conveyed by the conveyer 3. , the object to be weighed M7 is discharged from the weighing conveyor 1 when passing in front of the weighing conveyor 1 whose conveyor number is (7). Then, when the two objects M7 and M12 to be weighed are conveyed together by the transfer conveyor 3 and pass in front of the weighing conveyors 1 with the conveyor numbers (3) and (4), the two objects M7 and M12 are transferred from the two weighing conveyors 1. The weighed items M3 and M4 are discharged. Then, the four objects M3, M4, M7, and M12 to be weighed are transported together by the transport conveyor 3, and the transport operation to the transport conveyor 3 is completed so that they stop at the transport end region R of the transport conveyor 3 ( stop).

The transport end region R of the transport conveyor 3 is a transport end (unload end 3a) of the transport conveyor 3 and a predetermined region in the vicinity thereof. For example, as shown in FIG. , the area (area corresponding to the distance P) on the conveyor 3 corresponding to the center position of the unloading end 1a of the weighing conveyor 1 closest to the unloading end 3a of the conveyor 3. The transport end region R shown in the figure shows the region in the case of being the maximum region, and the predetermined region on the side of the discharge end 3a from the center position of the discharge end 1a of the weighing conveyor 1 closest to the discharge end 3a. good.

Here, the start timing of the transport operation of the plurality of weighing conveyors 1 selected for the discharge combination will be described.

In this embodiment, the objects to be weighed discharged from the respective weighing conveyors 1 are transported at the same position on the transport conveyor 3, so that the weighing conveyor 1 closer to the upstream end 3b of the transport conveyor 3 is transported in order. Let it start working.

Therefore, for example, as shown in FIG. 3, when four weighing conveyors 1 with conveyor numbers (3), (4), (7), and (12) are selected as the discharge combination, the controller 5 (timing The derivation unit 52) calculates the start time of the conveying operation of the weighing conveyor 1 with the conveyor number (7) with respect to the start time of the conveying operation of the weighing conveyor 1 with the conveyor number (12) that starts the conveying operation first. A delay time D1 and a delay time D2 of the start time of the transport operation of the weighing conveyors 1 with conveyor numbers (3) and (4) are calculated.

Here, the delay time D1 of the weighing conveyor 1 with the conveyor number (7) is the distance (2×L) between the centers of the carry-out ends 1a of the weighing conveyors 1 with the conveyor numbers (12) and (7), It can be calculated based on the transport speed Vt of the conveyor 3 . Here, the center-to-center distance (2×L) between the discharge ends 1a of the weighing conveyors 1 with conveyor numbers (12) and (7) is the "conveyance distance" of the discharge end 1a of the weighing conveyor 1 with the conveyor number (12). It can be calculated as the difference between 5L, which is the "position", and 3L, which is the "conveyance position" of the carry-out end 1a of the weighing conveyor 1 with the conveyor number (7). That is, the delay time D1 can be calculated by the following equation.

D1=(5L-3L)/Vt
The delay time D2 of the weighing conveyors 1 with conveyor numbers (3) and (4) is the center-to-center distance ( 4×L) and the transport speed Vt of the transport conveyor 3. Here, the center-to-center distance (4×L) between the unloading ends 1a of the weighing conveyors 1 with conveyor numbers (12), (3), and (4) is the unloading end of the weighing conveyor 1 with the conveyor number (12). It can be calculated as the difference between 5L, which is the "conveyance position" of 1a, and L, which is the "conveyance position" of the carry-out ends 1a of the weighing conveyors 1 with conveyor numbers (3) and (4). That is, the delay time D2 can be calculated by the following equation.

D2=(5L−L)/Vt
In addition, when the four weighing conveyors 1 with the above conveyor numbers (3), (4), (7), and (12) are the discharge combination obtained in the first combination process from the start of operation of the combination weigher, Since there are no objects to be weighed in the transport end region R of the transport conveyor 3, the weighing conveyor 1 with the conveyor number (12) may immediately start the transport operation when the discharge combination is obtained.

As described above, the control device 5 (timing derivation unit 52) selects the weighing conveyor 1 closest to the upstream end 3b of the transport conveyor 3 (sometimes two) among the weighing conveyors 1 selected for the discharge combination. is to start the transport operation first, and the start time (start timing) of the transport operation of the weighing conveyor 1 other than this is relative to the start time (start timing) of the transport operation of the weighing conveyor 1 that starts the transport operation first. By calculating the delay time (D1, D2, etc. described above), the start timing of the transport operation (discharge operation of the holding portion of the object to be weighed) of each of the weighing conveyors 1 selected for the discharge combination is obtained. .

Next, the start and end timings of the transport operation of the transport conveyor 3 will be described.

The control device 5 (operation control section 53) causes the transport conveyor 3 to immediately start the transport operation when the discharge request signal is input from the post-stage device 50 . Immediately after that, or at the same time, the control device 5 causes the weighing conveyor 1 selected for the discharge combination and starting the conveying operation first to start the conveying operation, and then timely conveys to the weighing conveyor 1 selected for the same discharge combination. start the action. In the above example, the weighing conveyor 1 with the conveyor number (12) is first caused to start the conveying operation, and after the delay time D1, the weighing conveyor 1 with the conveyor number (7) is caused to start the conveying operation, and the delay time After D2, the weighing conveyors 1 with conveyor numbers (3) and (4) are caused to start the conveying operation.

In the present embodiment, the control device 5 (operation control unit 53) controls that the objects to be weighed discharged from the plurality of weighing conveyors 1 selected as the discharge combination are conveyed by the conveyer 3, and the objects to be weighed are conveyed by the conveyer 3. The conveyer 3 is made to finish (stop) the conveying operation so as to stop at the end region R.

Therefore, the control device 5 (timing derivation unit 52), for example, sets the delay time De of the end time of the conveying operation of the conveyer 3 to the start time of the conveying operation of the weighing conveyor 1 that starts the conveying operation first. The end timing of the transport operation of the transport conveyor 3 is obtained by calculating from the following equation.

De = t1 + t2
In the above formula, t1 is a predetermined time required for each weighing conveyor 1 from the start of the transport operation until the object to be weighed is discharged to the transport conveyor 3, and is stored in the storage unit 7 in advance. there is

Further, t2 is the time until the object to be weighed (its center) discharged from the weighing conveyor 1 that starts the conveying operation first reaches the predetermined position X1 in the conveying end region R on the conveyer 3. 3 is the time to be transported on. This time t2 is based on the distance (Lx) from the center position of the carry-out end 1a of the weighing conveyor 1, which first starts the carrying operation, to the predetermined position X1 in the carrying end region R, and the carrying speed Vt of the carrying conveyor 3. can be calculated as t2=Lx/Vt.

Here, the predetermined position X1 is a position a predetermined distance P1 away from the center position of the unloading end 1a of the weighing conveyor 1 with the conveyor numbers (1) and (2) toward the unloading end 3a of the transport conveyor 3. For example, when the weighing conveyor 1 with the conveyor number (12) is to start the conveying operation first, the distance Lx to the predetermined position X1 is calculated using 5L, which is the "conveying position" of the same weighing conveyor 1. It can be calculated as 5L+P1. In this case, the predetermined distance P1 is stored in the storage unit 7 in advance. Further, the distance Lx may be associated with the conveyor number of each weighing conveyor 1 and stored in advance in the storage unit 7 .

As described above, the conveying operation of the conveyer 3 is finished after the delay time De from the start time of the conveying operation of the weighing conveyor 1 that starts the conveying operation first, so that the objects to be weighed are conveyed on the conveyer 3. stops at a predetermined position X1, and the center of the stopped object to be weighed is positioned within the transport end region R of the transport conveyor 3. As shown in FIG.

Note that when the start time of the transport operation of the weighing conveyor 1 that starts the transport operation first is set to be the same as the start time of the transport operation of the transport conveyor 3, that is, when the discharge request signal is input from the post-stage device 50, the transport is performed immediately. When the weighing conveyor 1, which starts the conveying operation first, starts the conveying operation at the same time when the conveyer 3 starts the conveying operation, the delay time De is the conveying operation time of the conveyer 3 (conveying time )become.

4 is a flow chart showing an example of the operation of the combination weigher shown in FIG. 1. FIG. The operation of this combination weigher is realized by the processing of the control device 5 . All the information and the like necessary for controlling the operation of the combination weigher are stored in the storage unit 7 .

In step S1, the control device 5 determines whether or not a predetermined condition (execution condition) for executing the combination process is satisfied. ask for one. It should be noted that the execution condition of the combination process in step S1 is, for example, that the objects to be weighed have been supplied to a predetermined number (for example, seven) of weighing conveyors 1 and their weights have already been weighed.

Next, in step S3, the control device 5 calculates the start timing (for example, the above-mentioned delay times D1 and D2) of the transport operation of each weighing conveyor 1 selected for the discharge combination, and in step S4, the transport conveyor 3 is calculated (for example, the delay time De described above).

Next, in step S5, the control device 5 determines whether or not a discharge request signal has been input from the post-stage device 50. If not, the process returns to step S1, and if it has been input, the process proceeds to step S6. Here, when returning to step S1, if the discharge combination obtained in step S2 this time (returned time) is different from the discharge combination obtained in the previous step S2, the discharge combination obtained in step S2 this time is used. The results of steps S3 and S4, which are updated and calculated based thereon, are also updated.

When a discharge request signal is input from the post-stage device 50, the controller 5 causes the conveyor 3 to start the conveying operation in step S6, and in step S7, conveys the weighing conveyors 1 selected for the discharge combination. Based on the operation start timing, each weighing conveyor 1 selected for the discharge combination is operated for a predetermined conveying time. This predetermined transport time is a predetermined time during which the weighing conveyor 1 is operated to discharge the objects to be weighed on the weighing conveyor 1 to the transport conveyor 3 .

Next, in step S8, the control device 5 causes the transport conveyor 3 to finish the transport operation based on the end timing of the transport operation of the transport conveyor 3 calculated in step S4.

It should be noted that when the transport operation of the transport conveyor 3 is started in step S6, the objects to be weighed on the weighing conveyor 1 that have been stopped in the transport end region R of the transport conveyor 3 and that have been selected for the previous discharge combination are transferred to the transport conveyor 3 is supplied to the post-stage device 50 through the funnel 21 from the unloading end 3a. Although not shown in FIG. 4, the control device 5 outputs a discharge notification signal to the post-stage device 50 after a predetermined time has passed since the transporting operation was started by the transporting conveyor 3 in step S6. The predetermined time here is determined in advance as the time required from the start of the transport operation of the transport conveyor 3 until the objects to be weighed that have stopped in the transport end region R of the transport conveyor 3 are discharged from the carry-out end 3a. It is time for

The above operations are repeated. Note that the order of steps S3 and S4 may be interchanged. Further, steps S3 and S4 may be performed between steps S5 and S6.

In this embodiment, the objects to be weighed discharged from each of the weighing conveyors 1 selected for the discharge combination are conveyed so as to be positioned (collected) at the same position on the conveying conveyor 3, and the conveying terminal of the conveying conveyor 3 is conveyed. It is made to stop in the state which gathered in the area|region R. FIG. As a result, when a discharge request signal is input from the post-stage device 50, the objects to be weighed can be discharged to the post-stage device 50 immediately, and the objects to be weighed can be discharged together. Therefore, it is possible to shorten the time from when the discharge request signal is input from the subsequent device 50 to when the object to be weighed is discharged to the subsequent device 50, thereby improving productivity.

(Modification)
FIG. 5 is a diagram showing a main part of a modification of this embodiment.

As shown in FIG. 5, in this embodiment, instead of the funnel 21, a collection hopper 31 may be provided. This collection hopper 31 has a discharge gate 31g, and after accommodating and temporarily holding the objects M to be weighed discharged from the discharge end 3a of the conveyer 3, opens the discharge gate 31g and discharges them to the downstream device 50 below. can do. The operation of the collecting hopper 31 (opening/closing operation of the discharge gate 31g) is controlled by the controller 5. FIG.

When such a collection hopper 31 is provided, the objects to be weighed discharged from the weighing conveyor 1 selected for the k-th (k is a positive integer) discharge combination determined after the operation of the combination weigher is started are held in the collecting hopper 31, the objects to be weighed discharged from the weighing conveyor 1 selected for the next (k+1)-time required discharge combination are held in the conveying end region R of the conveying conveyor 3. can. In this case, when a discharge request signal is input from the subsequent device 50, the control device 5 immediately opens and closes (opens and closes) the discharge gate 31g to discharge the objects to be weighed from the collection hopper 31, and issues a discharge notification signal. It can be output to the post-stage device 50 . In this case, when a discharge request signal is input from the subsequent device 50, the control device 5 immediately opens and closes the discharge gate 31g to discharge the objects to be weighed held in the collection hopper 31. Immediately before, at the same time, or immediately after closing the discharge gate 31g, the conveyer 3 is caused to perform a conveying operation so that the objects to be weighed held in the conveying end region R of the conveyer 3 can be accommodated in the collection hopper 31. You may make it start.

By providing the gathering hopper 31 in this way, the objects to be weighed are discharged from the gathering hopper 31 in a more collected state, so that the operation of the subsequent device 50 can be easily coordinated. In this case, when the control device 5 receives a discharge request signal from the post-stage device 50, it can immediately discharge the objects to be weighed from the collection hopper 31 to the post-stage device 50. Therefore, the discharge time (post-stage The time required for supply to the device 50 can be shortened, and the productivity can be further improved.

Further, as shown in FIG. 5, in the present embodiment, a path opening/closing section 41 for switching between closing and opening of the discharge path of the objects M to be weighed may be provided at the carry-out end 3a of the conveyor 3. FIG. The operation of the path opening/closing unit 41 is controlled by the controller 5 . The path opening/closing unit 41 opens the discharge path of the objects M to be discharged from the conveyor 3 during a period (time period Ta) from the start of the transportation operation of the conveyor 3 to the elapse of a predetermined time (ta). , and during periods other than this period Ta, the discharge route of the objects M to be weighed is closed to prevent the objects M to be discharged from the carry-out end 3a of the conveyor 3. It is The predetermined time (ta) is set in advance as the time required for all the objects to be weighed existing in the transport end region R to be discharged from the carry-out end 3a after the transport conveyor 3 starts the transport operation.

The path opening/closing unit 41 includes, for example, a vertical plate 41a in which a flat plate is vertically arranged, and a driving device (not shown) for moving the vertical plate 41a up and down. By closing the discharge route of the objects to be weighed on the conveyer 3, and by raising the vertical plate 41a to a predetermined elevated position, the discharge route of the objects to be weighed M on the conveyer 3 is opened. good. The path opening/closing unit 41 may include, for example, a double door and a driving device for opening and closing the door.

By providing such a path opening/closing unit 41, for example, even if the object to be weighed is an object that easily rolls, when the conveying operation of the conveyer 3 is finished (stopped), the object to be weighed does not move on the conveyer 3. The objects to be weighed can be prevented from dropping from the carry-out end 3a, and the objects to be weighed can be reliably stopped in the transfer end region R.

In the above example, the control device 5 calculates the end timing of the transport operation by the transport conveyor 3 (for example, the delay time De described above) and causes the transport conveyor 3 to end the transport operation based on it. Instead of this, as shown in FIG. 5, an object-to-be-weighed detection unit 11 for detecting an object to be weighed M that has reached the transport end region R of the transport conveyor 3 may be provided. The object detection unit 11 is configured using, for example, a photoelectric sensor, and outputs an article detection signal when detecting the object M to be weighed. This article detection signal is input to the control device 5 . In this case, the control device 5 causes the conveyer 3 to start the conveying operation, and then causes the conveyer 3 to end the conveying operation when the object to be weighed is newly detected by the object to be weighed detector 11 . Note that the object detection unit 11 to be weighed may be any device that can detect the object to be weighed, and other than the photoelectric sensor, for example, one using an ultrasonic sensor, one using a capacitance type proximity sensor, Alternatively, it may be one using a camera and an image processing device.

In this embodiment, the weighing units Cw are arranged on both sides of the conveyer 3, but the weighing units Cw may be arranged only on one side of the conveyer 3. FIG. Further, in this embodiment, a flat belt conveyor with a flat conveying surface is used as the conveyer 3, but instead of this, a trough-type belt conveyor with a concave central portion of the conveying surface may be used. good. Further, as the conveyer 3, two belt conveyors having endless flat belts may be arranged in parallel such that the conveying surface has a V-shaped cross section.

Further, in the present embodiment, belt conveyors are used as the weighing conveyor 1 and the transport conveyor 3, but roller conveyors or the like may be used depending on the type of objects to be weighed.

In this embodiment, the material to be weighed is supplied to the weighing conveyor 1 manually by an operator. good too.

In this embodiment, the objects to be weighed are directly discharged from each weighing conveyor 1 to the transport conveyor 3. ) is provided, the objects to be weighed weighed by each weighing conveyor 1 are conveyed to each standby conveyor, and the combination processing is performed based on the weight of the objects to be weighed held on the standby conveyor, and selected as the discharge combination. It may be configured such that the objects to be weighed are discharged from the standby conveyor to the transport conveyor 3 . Here, the weight of the object to be weighed held on the waiting conveyor is the weight weighed while held on the weighing conveyor 1 . In this case, the standby conveyor serves as the holding section for the objects to be weighed.

Further, in the present embodiment, the weighing conveyor 1 is used as the holding portion for the objects to be weighed, but instead of this, a hopper to which the objects to be weighed are supplied from above may be used. For example, instead of a plurality of weighing conveyors 1, a plurality of hoppers may be arranged in one or two straight lines in the conveying direction (arrow c direction) above the conveying conveyor 3 and arranged at predetermined positions. good too. In this case, one combination of hoppers (discharge combination) in which the total weight of the supplied objects to be weighed is within the target weight range is determined, and the objects to be weighed are discharged from the hoppers selected for that discharge combination. The discharged objects to be weighed are conveyed by the conveyer 3 . The hopper has a discharge gate, temporarily holds the objects to be weighed supplied from above, and discharges the objects to be weighed by opening and closing the discharge gate serving as a discharge port.

In this case, the start timing of the discharge operation of the hopper, that is, the start timing of the opening/closing operation of the discharge gate of the hopper can be obtained in the same manner as the start timing of the conveying operation of the weighing conveyor 1 is obtained.

Even if the hopper is supported by a weight sensor, the weight of the object to be weighed is measured, and the object to be weighed is automatically supplied to the hopper. Alternatively, it may be configured to be manually performed by an operator.

A second hopper is provided above the hopper to supply the object to be weighed to the hopper, and the second hopper is supported by a weight sensor to measure the weight of the object to be weighed. may be In this case, the material to be weighed may be supplied to the second hopper automatically or manually by an operator.

From the above description many modifications and other embodiments of the invention will be apparent to those skilled in the art. Accordingly, the above description is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Substantial details of construction and/or function may be changed without departing from the spirit of the invention.

INDUSTRIAL APPLICABILITY The present invention is useful as a combination weigher and a method for controlling the combination weigher that can improve productivity.

1 Weighing Conveyor 3 Transfer Conveyor 5 Control Device 11 Object to be Weighed Detector 31 Gathering Hopper 41 Path Opening/Closing Unit

Claims (7)

a conveyor that conveys the object to be weighed in one direction and discharges it to a subsequent device;
After temporarily holding the supplied objects to be weighed, the objects to be weighed are discharged from discharge ports to supply the objects to be weighed to the conveyer, and each of the discharge ports is located at a predetermined position with respect to the conveying direction of the conveyer. a plurality of holding parts for objects to be weighed arranged in
a combination processing unit that repeatedly performs combination processing for obtaining one discharge combination consisting of a combination of the holding units for the objects to be weighed in which the total weight of the held objects to be weighed is within the target weight range;
Each time the discharge combination is obtained by the combination processing, the discharge combination is selected based on the position of the discharge port of the object holding unit selected for the discharge combination and the conveying speed of the conveyer. and a timing derivation unit that determines the start timing of the discharge operation of each of the object holding units so that the objects to be weighed ejected from the object holding units are positioned at the same position on the conveyor. ,
Each time a discharge request signal is input from the post-stage device, the conveyer is caused to start the carrying operation, and the holding section for the object to be weighed is caused to start the discharging operation based on the start timing obtained by the timing derivation section. and further, after causing the conveyer to start the conveying operation, the object to be weighed discharged from the object-to-be-weighed holding portion is conveyed so that the object to be weighed stops at the conveying end region of the conveyer. a motion control unit that causes the transport conveyor to finish the transport operation at the time;
combination weigher. The timing derivation unit
Each time the discharge combination is obtained by the combination processing, the discharge of the object-to-be-weighed holding portion positioned most upstream in the conveying direction of the conveyer among the object-to-be-weighed holding portions selected as the discharge combination is performed. Based on the position of the exit, the end timing of the transport operation of the transport conveyor so that the object to be weighed discharged from the object holding unit and transported by the transport conveyor stops in a transport end region of the transport conveyor. seeking
The operation control unit is
After causing the conveyer to start the conveying operation, the conveyer is configured to end the conveying operation based on the end timing obtained by the timing derivation unit,
The combination weigher according to claim 1. further comprising an object-to-be-weighed detection unit that detects an object to be weighed existing in a transfer end region of the conveyer;
The operation control unit is
When the object to be weighed is newly detected by the object-to-be-weighed detection unit while causing the conveyer to carry out the conveying operation, the conveyer is configured to end the conveying operation.
The combination weigher according to claim 1. further comprising a collecting hopper that receives and temporarily holds the objects to be weighed discharged from the discharge end of the conveyer, and then discharges them to the post-stage device;
The operation control unit is
configured to immediately discharge the objects to be weighed from the gathering hopper when a discharge request signal is input from the post-stage device,
The combination weigher according to any one of claims 1 to 3. further comprising a route opening/closing unit for switching between closing and opening of the discharge route of the object to be weighed at the carry-out end of the conveyer;
The path opening/closing section opens the discharge path to enable discharge of the objects to be weighed from the conveyer during a period from the start of the conveying operation of the conveyer until a predetermined time elapses. between is configured to close the discharge path to prevent discharge of the object to be weighed from the conveyer,
The combination weigher according to any one of claims 1 to 4. The holding part for the object to be weighed is
A weighing conveyor that is supplied with an object to be weighed while in a transport stop state, temporarily holds and weighs the supplied object to be weighed, and discharges the held object to be weighed by conveying it for a predetermined time. configured,
The combination weigher according to any one of claims 1 to 5. a conveyor that conveys the object to be weighed in one direction and discharges it to a subsequent device;
After temporarily holding the supplied objects to be weighed, the objects to be weighed are discharged from discharge ports to supply the objects to be weighed to the conveyer, and each of the discharge ports is located at a predetermined position with respect to the conveying direction of the conveyer. a plurality of holding parts for objects to be weighed arranged in
A control method for a combination weigher comprising
Repeating a combination process for obtaining one discharge combination consisting of a combination of the holding parts for the objects to be weighed in which the total weight of the held objects to be weighed is within the target weight range,
Each time the discharge combination is obtained by the combination processing, the discharge combination is selected based on the position of the discharge port of the object holding unit selected for the discharge combination and the conveying speed of the conveyer. a timing derivation process for obtaining a start timing of the discharging operation of each of the object-to-be-weighed holding units so that the objects to be weighed ejected from the object-to-be-weighed holding units are positioned at the same position on the conveyor; do,
Each time a discharge request signal is input from the post-stage device, the conveyer is caused to start the carrying operation, and the holding section for the object to be weighed is caused to start the discharging operation based on the start timing obtained in the timing derivation process. and further, after causing the conveyer to start the conveying operation, the object to be weighed discharged from the object-to-be-weighed holding portion is conveyed so that the object to be weighed stops at the conveying end region of the conveyer. performing an operation control process to cause the conveyer to finish the conveying operation,
Control method of combination weigher.

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