JP5669096B2 - Combination scale - Google Patents

Description

  The present invention relates to a combination weigher for weighing objects to be weighed such as vegetables, fruits or confectionery.

  Generally, objects to be weighed such as vegetables and fruits that have been weighed with a combination weigher to have a predetermined weight are packaged by a packaging machine, for example.

  FIG. 7 is a diagram schematically showing a schematic configuration of a conventional combination weigher of Patent Document 1. As shown in FIG.

  In this combination weigher, an object to be weighed is supplied from a supply device 30 to the center of a main feeder (dispersion feeder) 31, and the main feeder 31 sends out the object to be weighed toward the peripheral portion by vibration, and around the main feeder 31. It conveys to the several linear feeder 32 installed radially.

  A vibration device is attached to the plurality of linear feeders 32, and each linear feeder 32 is vibrated to convey an object to be weighed and put into the plurality of supply hoppers 33. The plurality of supply hoppers 33 temporarily hold the objects to be weighed, open the discharge gate 34, and put the objects to be weighed into the weighing hoppers 35 disposed below the supply hoppers 33. In each weighing hopper 35, the weight of the object to be weighed is measured by the weight sensor 36, and a control unit (not shown) performs a combination operation based on the measured value, so that the total of the measured values matches the combined target weight. The closest combination of the weighing hoppers 35 is obtained, the discharge gate 37 of the weighing hopper 35 selected in this combination is opened, the objects to be weighed are discharged, and the packaging hopper 39 is inserted through the collecting chute 38, Packaging is performed by a packaging machine 39.

JP 62-1113024 A

  When such a combination weigher is used to produce a pack product containing several pieces by performing combination weighing of vegetables such as peppers, onions, potatoes, or fruits such as oranges and apples, the linear feeder is used. By vibrating 32, the number of objects to be weighed in the supply hopper 33 may be about 1, 2 for example. The objects to be weighed put into the supply hopper 33 are put into the lower weighing hopper 35 by opening the discharge gate 34 of the supply hopper 33 and weighed by the weight sensor 36, and the combination calculation is performed.

  In the combination weigher, in order to measure the exact weight of an object to be weighed into the weighing hopper 35, the weight sensor 36 after a preset stable time has elapsed since the object to be weighed into the weighing hopper 35 was introduced. The stable measured value is the weight value of the object to be weighed put into the weighing hopper 35.

  This stabilization time is measured, for example, starting from the point of time when the discharge gate 34 of the supply hopper 33 is opened in order to put the object in the supply hopper 33 into the measurement hopper 35.

  It is not a problem that the weighing object held in the supply hopper 33 is put into the weighing hopper 35 by opening the discharge gate 34 of the supply hopper 33. For example, when the object to be weighed is stopped in an unstable state at the transport end which is the tip of the linear feeder 32 above the supply hopper 33 by opening the gate 34 for the discharge, The unbalanced object to be weighed undesirably drops due to vibrations associated with the opening of the gate 34, and passes through the supply hopper 33 in which the discharge gate 34 is opened as it is. May be placed directly into

  In this case, the object to be weighed held in the supply hopper 33 is put into the weighing hopper 35, and then the object to be weighed which has remained in an unstable state at the conveying end of the linear feeder 32 above the supply hopper 33. However, it is thrown into the weighing hopper 35 with a delay.

  In this way, when the object to be weighed is introduced into the weighing hopper 35 later than the original introduction time when the object to be weighed in the supply hopper 33 is introduced, the discharge gate 34 of the supply hopper 33 is opened. In the stabilization time measured from the starting point, the measurement value of the weight sensor 36 is shorter than the time necessary for stabilization, and an accurate measurement value cannot be obtained, resulting in erroneous measurement.

  In such a case, it may be possible to set a long stabilization time in advance so that an accurate measurement value can be obtained. However, if the stabilization time is increased, high-speed measurement cannot be performed correspondingly, and the measurement speed Will fall.

  The present invention has been made in view of the above-described points, and an object of the present invention is to prevent erroneous weighing due to an object to be weighed inserted later than the original charging time.

  In order to achieve the above object, the present invention is configured as follows.

(1) The combination weigher of the present invention is arranged corresponding to each of the plurality of conveyance units that convey the object to be measured, drop it from the conveyance end and discharge it, and is discharged from the conveyance end. A plurality of discharge units that hold the objects to be weighed and drop and discharge the held objects to be weighed, and are arranged corresponding to each discharge unit, and hold the objects to be weighed discharged from each discharge unit, A plurality of weighing units for weighing the weight of the held objects to be weighed, and a combination operation based on the weight of the objects to be weighed after a stable time measured by the weighing unit, and the conveyance control of each of the conveying units And an arithmetic control unit that performs discharge control of each discharge unit, wherein a combination object sensor that detects an object to be measured at each transfer end of each transfer unit is provided , and the calculation control unit includes: The object to be weighed is based on the detection output of the object sensor. When it is turned on with a delay to the amount unit prolongs the stabilization time for the metering unit.

  In the combination weigher of the present invention, the plurality of transport units transport the object to be weighed and drop and discharge it from the transport end, and the plurality of discharge units hold the object to be weighed and discharged from the transport end. The held weighing object is dropped and discharged, and the multiple weighing units hold the weighing object that is dropped and discharged from the discharge unit, and weigh the weighing object after the stable time has elapsed to perform the combination calculation. ing.

  In this combination weigher, when the object to be weighed held by the discharge unit is dropped and discharged to the weighing unit, for example, the object to be weighed that is stopped in an unstable state at the transport end of the transport unit is undesired. There is a case where it falls and is passed through the discharge part in a state where the object to be weighed is discharged as it is and dropped into the measurement part with a delay.

  According to the combination weigher of the present invention, since the weighing object sensor for detecting the weighing object at the conveying end of the conveying unit is provided, the weighing object sensor detects that the weighing object at the conveying end has dropped. If an object to be weighed that has stopped in an unstable state at the transport end of the transport unit falls undesirably and is thrown into the weighing unit with a delay, the weighing unit has a stable time. It can be extended. Accordingly, the measured value after the elapse of the extended stable time can be used as the weight of the object to be weighed, and erroneous weighing can be prevented. In addition, since the stabilization time is extended only for the measurement unit in which the object to be weighed is put in the measurement unit with a delay, there is no decrease in the measurement speed as in the case where the setting of the stabilization time is uniformly extended.

 “It was thrown into the weighing section” means that the object to be weighed held in the discharge section was thrown in after the original timing of discharge from the discharge section and into the weighing section. That means.

  It is preferable to extend the stabilization time in accordance with the delay time of input, but it may be extended for a preset time.

According to the combination weigher of the present invention, since the weighing object sensor for detecting the weighing object at the conveying end of the conveying unit is provided, it is possible to detect that the weighing object at the conveying end is dropped by the weighing object sensor, As a result, when an object to be weighed that has stopped in an unstable state at the transport end of the transport unit falls undesirably, and the object to be weighed is thrown into the weighing unit with a delay, a stable time is set for the weighing unit. The measured value after the elapse of the extended stable time can be used as the weight of the object to be weighed, and erroneous weighing can be prevented. In addition, since the stabilization time is extended only for the measurement unit in which the object to be weighed is put in the measurement unit with a delay, there is no decrease in the measurement speed as in the case where the setting of the stabilization time is uniformly extended.

( 2 ) In another preferred embodiment of the combination weigher of the present invention, the calculation control unit is thrown into the weighing unit with a delay based on the detection output of the object sensor and the discharge control timing of the discharge unit. In addition, it is determined whether or not there is an object to be weighed, and when it is determined that there is an object to be weighed that has been thrown into the weighing unit, the stabilization time for the determined weighing unit is extended.

  According to this embodiment, since the weighing object sensor for detecting the weighing object at the conveyance end of the conveyance unit is provided, it is possible to detect that the weighing object at the conveyance end is dropped by the weighing object sensor. Since the calculation control unit to which the detection output of the weighing object sensor is given controls the discharging of the discharging unit, it is possible to grasp the timing at which the weighing object of the discharging unit is discharged to the weighing unit. It is possible to detect whether or not the object to be weighed at the transport end of the transport unit has dropped when the object to be weighed is discharged.

  As a result, the object to be weighed that has stopped in an unstable state at the transport end of the transport unit falls undesirably, and passes through the discharge part in the discharge state where the object to be weighed is discharged. If it is determined that an object to be weighed has been thrown into the weighing unit, the stable time is extended for the weighing unit, and the measured value after the extended stable time has elapsed. The weight of the object to be weighed can be set, and erroneous weighing can be prevented. In addition, the extension of the stabilization time is performed only for the weighing unit when it is determined that the object to be weighed is delayed in the weighing unit. There is no decline.

( 3 ) In a preferred embodiment of the combination weigher of the present invention, the plurality of transport units are a plurality of vibration feeders that transport the object to be weighed supplied from the dispersion unit by vibration, and the plurality of discharge units are: A plurality of supply hoppers for discharging the held objects to be supplied to the measuring unit, wherein the plurality of measuring units are a plurality of measuring hoppers for measuring the weight of the object to be measured by a weight sensor; The unit controls the driving of the vibration feeder and controls the opening and closing of the discharge gate of the supply hopper.

  According to this embodiment, the arithmetic control unit measures the object to be weighed by opening the gate for discharging the supply hopper based on the detection output of the object sensor for detecting the object to be weighed at the conveyance end of the vibration feeder. When being discharged to the hopper, an object to be weighed that has stopped in an unstable state at the transport end of the vibration feeder falls undesirably due to vibration caused by opening of the discharge gate, and the discharge When it is judged that the gate hopper has passed through the open supply hopper and dropped to the weighing hopper, the stabilization time for the weighing hopper is extended, and the measured value after the extended stabilization time has passed. It is possible to use the weight of an object, and it is possible to prevent erroneous weighing.

( 4 ) In the embodiment of ( 3 ), the arithmetic control unit detects an object to be weighed at the conveyance end of the vibration feeder when the discharge gate of the supply hopper is shifted from closed to open. When the detection output of the weighing object sensor is in the closed state, it is in a detection state in which the weighing object is detected, and in the opening state, the state shifts to a non-detection state in which the measurement object is not detected. In this case, it may be determined that an object to be weighed at the transport end of the vibration feeder has dropped, passed through a supply hopper in which the discharge gate is opened, and is thrown into the weighing hopper with a delay.

  According to this embodiment, the detection output of the weighing object sensor for detecting the weighing object at the conveyance end of the vibration feeder detects that the weighing object is detected in the state where the discharge gate of the supply hopper is closed. In the state where the discharge gate is opened, when the transition to the non-detection state in which the object to be weighed is not detected, the discharge gate of the supply hopper is opened, It is determined that the object to be weighed dropped and disappeared, passed through the supply hopper with the discharge gate open, and was put into the weighing hopper late, and the stabilization time for the weighing hopper was extended. The measured value after the elapse of the extended stable time can be used as the weight of the object to be weighed, and erroneous weighing can be prevented.

( 5 ) In the embodiment of the above ( 4 ), the calculation control unit detects that the detection output of the weighing object sensor is in the non-detection state from the time when the discharge gate of the supply hopper is shifted to the open state. The stabilization time may be extended according to the time until the point of transition to (1).

 “The time when the discharge gate is shifted to the opening” may be the time when the opening of the discharge gate is started, or the time when the discharge gate is completely opened, Alternatively, it may be a time point between the two time points.

  According to this embodiment, the material to be weighed at the conveyance end of the vibration feeder drops from the original loading time when the discharge hopper discharge gate is opened and the material to be weighed in the supply hopper is loaded into the weighing hopper. The stabilization time is extended according to the time until the detection output of the object sensor shifts to the non-detection state, i.e., the delay time of loading the object to be weighed into the weighing hopper. A stable time can be secured, and erroneous weighing can be prevented more reliably.

( 6 ) In another embodiment of the combination weigher of the present invention, the calculation control unit drives the vibration feeder over a set time to convey an object to be weighed, and at the conveyance end of the vibration feeder The detection output of the measurement object sensor for detecting the measurement object detects the measurement object from the non-detection state where the measurement object is not detected when the vibration feeder is driven for the set time. When the detected state is not shifted, the vibration feeder is further driven.

  In the case of further driving the vibration feeder, it is preferable to continue the drive following the drive for the set time, but the drive for the set time may be temporarily stopped and restarted.

  Further, when the vibration feeder is further driven, it is preferably driven until the detection output of the object sensor shifts to a detection state in which the object to be weighed is detected, but it is driven for a predetermined time. You may do it.

  According to this embodiment, the vibration feeder is driven for a set time to drop the object to be weighed from the transport end and put into the supply hopper. However, the vibration feeder is driven to drop the object to be weighed at the transport end. When the detection output of the object sensor for detecting the object to be measured at the conveyance end of the vibration feeder becomes a non-detection state in which the object to be weighed is not detected. When it does not shift to the detection state in which the weighing object is detected, there is no object to be weighed at the conveying end of the vibration feeder, and if the vibration feeder is stopped in this state, the vibration feeder is stopped in the next cycle. Even if is driven, the object to be weighed cannot be supplied to the supply hopper, and the object to be weighed cannot be fed from the supply hopper to the weighing hopper.

  In this embodiment, in such a case, since the vibration feeder is further driven, the object to be weighed can be transported to the transport end and can be put into the supply hopper in the next cycle.

  According to the present invention, since the weighing object sensor for detecting the weighing object at the conveyance end of the conveying unit is provided, it is possible to detect that the weighing object at the conveyance end is dropped by this weighing object sensor, When an object to be weighed that is stopped in an unstable state at the transport end of the transport unit falls undesirably and the object to be weighed is thrown into the weighing unit with a delay, the stabilization time is extended for the weighing unit. It becomes possible. Accordingly, the measured value after the elapse of the extended stable time can be used as the weight of the object to be weighed, and erroneous weighing can be prevented. In addition, since the stabilization time is extended only for the measurement unit in which the object to be weighed is put in the measurement unit with a delay, there is no decrease in the measurement speed as in the case where the setting of the stabilization time is uniformly extended.

FIG. 1 is a schematic diagram showing a schematic configuration of a combination weigher according to an embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of the combination weigher of FIG. FIG. 3 is a time chart when the object to be weighed is normally put into the weighing hopper. FIG. 4 is a schematic diagram showing the state of each part corresponding to FIG. FIG. 5 is a time chart when an object to be weighed is put into the weighing hopper with a delay. FIG. 6 is a schematic diagram showing the state of each part corresponding to FIG. FIG. 7 is a schematic configuration diagram of a conventional combination weigher.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing a schematic configuration of a combination weigher according to an embodiment of the present invention. The combination weigher of this embodiment has a conical top cone 3 that radially disperses the objects 20 to be weighed supplied from the supply device 1 at the center of the apparatus, and a main feeder that vibrates the top cone 3. (Dispersion feeder) 4 is provided.

  The object to be weighed 20 is not limited, but is suitable for weighing vegetables such as peppers, tomatoes and potatoes, fruits such as oranges and apples, or confectionery packed in pillows, and in particular, combination weighing. It is suitable for manufacturing a net packaged product containing several pieces.

  The supply device 1 conveys an object to be weighed 20 such as bell pepper supplied from a belt conveyor (not shown) by vibration and supplies it to the central portion of the top cone 3. In the top cone 3, the object to be weighed 20 supplied from the supply device 1 to the central portion thereof is conveyed toward the peripheral portion by vibration. Around the top cone 3, a plurality of linear feeder pans 6 for conveying the objects 20 to be weighed sent from the top cone 3 to a plurality of supply hoppers 12 and a plurality of linear feeder pans 6 for vibrating the linear feeder pans 6. Feeders 8 are provided radially. A plurality of supply hoppers 12 as discharge portions are provided below the peripheral edge of the linear feeder pan 6, and a weighing hopper 13 as a weighing portion is provided below the supply hopper 12. It is arranged in a circle.

  Under the supply hopper 12 and the weighing hopper 13, a discharge gate 12a and a gate 13a that can be opened and closed are provided.

  The supply hopper 12 receives an object 20 to be weighed 20 that is transported by the linear feeder pan 6 and dropped and discharged from the transport end 6a that is the tip of the supply hopper 12, and when the weighing hopper 13 that is disposed below is empty, a discharge gate 12a. Is opened to drop and discharge the object 20 to be weighed into the weighing hopper 13. Each weighing hopper 13 is connected to a weight sensor 10 such as a load cell for measuring the weight of the object 20 in the weighing hopper 13, and a measured value from each weight sensor 10 is output to the control device 9.

  The plurality of linear feeder pans 6 and the plurality of linear feeders 8 that respectively vibrate the respective linear feeder pans 6 constitute a plurality of transport units that transport the objects to be weighed 20 to the corresponding supply hoppers 12.

  The weighing hopper 13 can discharge the objects 20 to the collecting chute 14. When a combination of the weighing hoppers 13 from which the objects to be weighed 20 are to be discharged is obtained from the plurality of weighing hoppers 13 by the combination calculation by the control device 9, and when a discharge request signal is input from the packaging machine 15 for net packaging, The objects to be weighed 20 are discharged from the weighing hopper 13 corresponding to the combination to the collecting chute 14 and further discharged to the lower packaging machine 15.

  In this embodiment, the amount of the weighing object supplied from the supply device 1 to the top cone 3 is measured by the top cone weight sensor 5 supporting the top cone 3 and the main feeder 4, and the measured value is controlled. It is given to the device 9. In the control device 9, based on the weight of the weighing object 20 on the top cone 3 measured by the top cone weight sensor 5, the supply of the weighing object 20 on the top cone 3 is kept constant. The apparatus 1 is controlled.

  The operation setting display unit 11 is configured using, for example, a touch panel or the like, and performs operation of the combination weigher, setting of operation parameters thereof, and the like, and displays an operation speed, a combination measurement value, and the like on a screen.

  The control device 9 performs operation control of the supply device 1 and overall operation of the combination weigher, and performs combination calculation. In the combination calculation, the weight of the weighing object 20 in the weighing hopper 13 is weighed by the weight sensor 10, and the measured value after the stable time has elapsed is set as the weight of the weighing object 20 in the weighing hopper 13 as will be described later. From the plurality of weighing hoppers 13, one combination is obtained in which the combined weight that is the sum of the weight values of the objects to be weighed 20 is equal to the combined target weight or the closest weight within the allowable range.

  In this embodiment, in order to prevent erroneous weighing due to an object to be weighed into the weighing hopper 13 later than the original loading time, at the conveying end 6a that is the tip of each of the plurality of linear feeder pans 6. A plurality of weighing object sensors 7 for detecting the weighing objects 20 are provided. In this embodiment, for example, a photoelectric sensor is used as the object sensor 7 for detecting an object to be weighed. However, the sensor is not limited to the photoelectric sensor, but an image sensor that processes an image captured by a limit switch, a weight sensor, or a camera. Other sensors such as may be used.

  Based on the detection output of the weighing object sensor 7, when the weighing object 20 at the conveying end 6a of the linear feeder pan 6 is opened as described later, the discharge gate 12a of the supply hopper 12 is opened. It is detected that it falls undesirably, passes through the supply hopper 12 and is put into the weighing hopper 13 with delay, and the preset stabilization time is extended according to this delay time.

  FIG. 2 is a block diagram showing a schematic configuration of the control system of the combination weigher in this embodiment, and the same reference numerals are given to the portions corresponding to FIG.

  As shown in FIG. 2, the control device 9 includes a CPU unit 16 as an arithmetic control unit, a memory unit 17, an A / D conversion circuit unit 18, a gate drive circuit unit 19, a vibration control circuit unit 21, And an I / O circuit unit 22 connected to the packaging machine 15.

  The CPU unit 16 serving as a calculation control unit controls each unit and performs a combination calculation. The memory unit 17 stores an operation program for the combination weigher, operation parameters to be set, and the like, and serves as a work area for operations on the CPU unit 16. The A / D conversion circuit unit 18 includes a weight sensor 5 for detecting the weight of the weighing object 20 on the top cone 3 and a weight sensor 10 for detecting the weight of the weighing object 20 of each weighing hopper 13. The analog signal is converted into a digital signal and output to the CPU unit 16. Further, the CPU unit 16 is provided with a detection output from the above-described object sensor 7 that detects the object to be weighed at the conveyance end 6 a of each linear feeder pan 6 via the I / O circuit unit 25.

  The gate drive circuit unit 19 controls the opening and closing of the discharge gates 12 a and 13 a of the supply hopper 12 and the weighing hopper 13 based on a control signal from the CPU unit 16. The vibration control circuit unit 21 controls each vibration operation of the supply device 1, the main feeder 4, and each linear feeder 8 based on a control signal from the CPU unit 16. The CPU unit 16 is connected so as to be able to communicate with the operation setting display unit 11.

  The control device 9 controls the operation of the supply device 1 and the entire combination weigher by the CPU unit 16 executing the operation program stored in the memory unit 17.

  In the combination weigher, it is necessary to set a large number of operation parameters for performing the operation as described above, and the setting is performed by the operator using the operation setting display unit 11, and the value of the set operation parameter is the CPU unit. 16 and stored in the memory unit 17. The operation parameters include a combination target weight which is a target value in the combination calculation and an allowable range thereof, vibration amplitude and driving time (one vibration continuation time) of each of the feeders 4 and 8, a stabilization time, and the like.

  Next, an operation for preventing erroneous weighing due to the weighing object 20 being thrown into the weighing hopper 13 will be described.

  First, the operation when the weighing object 20 is thrown into the weighing hopper 13 at a normal timing will be described based on the time chart of FIG. 3 and the schematic diagram of FIG.

  FIG. 3 shows an example of a time chart showing the measurement states of the hoppers 12 and 13, the linear feeder 8, the object sensor 7, and the stable time, and FIG. 3 (a) is for discharging the weighing hopper 13. The gate opening / closing (on / off) operation of the gate 13a, FIG. 5 (b) shows the opening / closing (on / off) operation of the discharge gate 12a of the supply hopper 12, FIG. 4 (c) shows the operation of the linear feeder 8 and FIG. ) Shows the detection state of the object sensor 7, and FIG. 9E shows the measuring operation by the counter of the stable time. Note that FIG. 3 shows an example of each operation, and the timing of each operation is not limited to that in FIG. 3, and there may be a difference in timing. Not only when the opening of the discharge gate 12a of the supply hopper 12 is started but also when the opening is completed.

  FIG. 4 is a schematic diagram showing the states of the hoppers 12 and 13, the linear feeder pan 6, the weighing object sensor 7, and the weighing object 20 corresponding to FIG. 3. FIGS. 3 and 4 representatively show a set of weighing units including the linear feeder 8, the linear feeder pan 6, the supply hopper 12 and the weighing hopper 13.

  First, the discharge gate 13a of the weighing hopper 13 selected by the combination calculation is opened at the timing t1 shown in FIG. 3A and the object 20 is discharged, and the discharge gate is discharged at the timing t2. As shown in FIG. 4A, the weighing hopper 13 is in an empty state without an object to be weighed. In this state, the object to be weighed 20a transported by driving the linear feeder 8 in the previous cycle is put into the supply hopper 12 and held, and the object to be weighed 20b is held at the transport end 6a of the linear feeder pan 6. It is transported and waiting. In this state, the weighing object 20b at the conveyance end of the linear feeder pan 6 is detected by the weighing object sensor 7, and the detection output of the weighing object sensor 7 is detected as shown in FIG. The state is on.

  Next, as shown in FIG. 3 (b), the discharge gate 12a of the supply hopper 12 was opened at the timing t2, and held in the supply hopper 12 as shown in FIG. 4 (b). The object to be weighed 20a is put into the weighing hopper 13, and the discharge gate 12a of the supply hopper 12 is closed at the timing t3.

  Next, as shown in FIG. 3C, the linear feeder 8 starts to be driven at the timing t3. With the start of this drive, the object 20b at the conveying end 6a of the linear feeder pan 6 falls to the supply hopper 12 as shown in FIG. 4 (c), and as shown in FIG. The discharge gate 12a is charged and held in the closed supply hopper 12. At this time, the object to be weighed 20b at the conveying end 6a of the linear feeder pan 6 is not detected by the object to be weighed sensor 7, so that the detection output of the object to be weighed sensor 7 is temporarily non-existing as shown in FIG. Although the detection state is turned off, as the linear feeder 8 is driven, a new object 20c is conveyed to the conveying end 6a of the linear feeder pan 6 and detected as shown in FIG. Then, the detection state is turned on again.

  As described above, the CPU 16 serving as the control calculation unit is a timing at which a preset stable time T1 has elapsed from the timing t2 when the discharge gate 12a of the supply hopper 12 shown in FIG. The measurement value of the weight sensor 10 obtained at t4 is set as the weight of the object 20a, and the combination calculation is performed based on this weight.

  Next, the operation when the workpiece 20 is thrown into the weighing hopper 13 will be described with reference to the time chart of FIG. 5 and the schematic diagram of FIG.

  First, the discharge gate 13a of the weighing hopper 13 selected by the combination calculation is opened at the timing t1 shown in FIG. 5A, and the object 20 is discharged, and the discharge gate is discharged at the timing t2. As shown in FIG. 6A, the weighing hopper 13 is in an empty state without an object to be weighed. In this state, the object to be weighed 20a transported by driving the linear feeder 8 in the previous cycle is put into the supply hopper 12 and held, and the object to be weighed 20b is held at the transport end 6a of the linear feeder pan 6. It is transported and stopped in an unstable state. At this time, the weighing object 20b at the conveyance end of the linear feeder pan 6 is detected by the weighing object sensor 7, and the detection output of the weighing object sensor 7 is detected as shown in FIG. Is turned on.

  Next, as shown in FIG. 5B, the discharge gate 12a of the supply hopper 12 is opened at the timing t2, and the measurement target held in the supply hopper 12 as shown in FIG. 6B. The object 20 a is put into the weighing hopper 13. At this time, the object to be weighed 20b that has stopped in an unstable state on the conveying end 6a of the linear feeder pan 6 due to vibration or the like when the discharge gate 12a of the supply hopper 12 is opened undesirably falls. 6 (b) and 6 (c), it passes through the supply hopper 12 in which the discharge gate 12a is opened as it is, and is put into the weighing hopper 13 with a delay. As the object 20b is undesirably dropped from the conveyance end 6a of the linear feeder pan 6, the object 20b cannot be detected by the object sensor 7 as shown in FIG. Goes off, which is a non-detection state. Thereafter, the discharge gate 12a of the supply hopper 12 is closed, and as shown in FIG. 5C, the linear feeder 8 starts to be driven at the timing t3 and is driven for the set time until the timing t5. The By driving the linear feeder 8 for a set time, as shown in FIG. 6 (d), a new object 20c is introduced from the linear feeder pan 6 into the supply hopper 12 and held, and the linear feeder pan 6 is also held. A new weighing object 20d is conveyed to the conveying end 6a. As a result, the weighing object sensor 7 detects the new weighing object 20d conveyed to the conveying end 6a of the linear feeder pan 6, and the detection output is detected again as shown in FIG. 5 (d). The state is turned on.

  As described above, for example, when the object to be weighed 20b is stopped in an unstable state at the transport end 6a of the linear feeder pan 6, for example, the linear feeder 8 is not driven, A supply hopper in which the object to be weighed 20b at the conveying end 6a of the linear feeder pan 6 is undesirably dropped due to vibration when the discharge gate 12a of the supply hopper 12 is opened, and the discharge gate 12a is opened. 12 may pass through the weighing hopper 13 with a delay.

  In this case, the weighing hopper 13 is unstable due to the conveying end 6a of the linear feeder pan 6 above the supply hopper 12 in addition to the object to be weighed 20a opened by opening the discharge gate 12a of the supply hopper 12. The object to be weighed 20b that has stopped in the state falls undesirably and is thrown in after passing through the supply hopper 12.

  In this way, when the weighing object 20b is loaded into the weighing hopper 13 later than the original timing of loading the weighing object 20a, the measurement is started from the timing t2 when the discharge gate 12a of the supply hopper 12 is opened. In the stabilization time T1 shown in FIG. 5 (e), the measurement value is shorter than the time necessary for stabilization, and an accurate measurement value cannot be obtained, resulting in erroneous measurement.

  Therefore, in this embodiment, when the discharge gate 12a of the supply hopper 12 is opened and the measurement object 20a of the supply hopper 12 is put into the measurement hopper 13, it is detected by the measurement object sensor 7. When the object to be weighed 20b at the conveying end 6a of the linear feeder pan 6 is no longer detected, it is determined that the object to be weighed 20b at the conveying end 6a has dropped undesirably and has been thrown into the weighing hopper 13 and supplied. The time T2 from the time t2 when the discharge gate 12a of the hopper 12 is opened to the time t2 ′ when the object 20b is no longer detected by the object sensor 7 is thrown into the weighing hopper 13 with delay. From the time t2 when the original stabilization time T1 is extended by the delay time T2 and the discharge gate 12a of the supply hopper 12 is opened. The weighing of the weight sensor 10 at the time of (T1 + T2) has elapsed, and the weight of the objects to be weighed inside the weighing hopper 13.

  As described above, when the object to be weighed 20 is thrown into the weighing hopper 13 with a delay from the original throwing timing, the stabilization time T1 is extended by the delay time T2, and erroneous weighing can be prevented.

  In addition, since the stabilization time is extended only for the weighing hopper 13 when it is determined that the weighing hopper 13 has been thrown in late, the weighing speed is lowered as in the case where the stabilization time is uniformly set longer. Nor.

(Other embodiments)
As shown in FIGS. 3C and 3D or FIGS. 5C and 5D, when the linear feeder 8 is driven for a set time, the conveyance end 6a of the linear feeder pan 6 is weighed. Since the object falls and then a new object to be weighed is conveyed to the conveyance end 6a of the linear feeder pan 6, the detection output of the object sensor 7 is detected from the ON detection state in which the object to be weighed is detected. Then, after shifting to the OFF non-detection state in which the object to be weighed is not detected, the state shifts again to the ON detection state in which the object to be weighed is detected.

  However, for example, the object to be weighed may not be smoothly supplied from the top cone 3 on the upstream side of the linear feeder pan 6, and the object to be weighed may be conveyed discontinuously on the linear feeder pan 6. In such a case, even if the linear feeder 8 is driven for a set time, the object to be weighed cannot be transported to the transport end 6 a of the linear feeder pan 6, and the object to be weighed cannot be put into the supply hopper 12.

  Therefore, in another embodiment of the present invention, when the linear feeder 8 is driven for a set time, the detection output of the object sensor 7 is in an off non-detection state where the object to be weighed is not detected once. If the weighing object is not detected and the ON detection state is not reached, a new weighing object is not conveyed to the conveying end 6a of the linear feeder pan 6, and thus the linear feeder 8 is continuously driven. You may do it. It is preferable that the linear feeder 8 is continuously driven until the detection output of the weighing object sensor 7 is turned on to detect the weighing object, but continues for a predetermined time. You may do it.

  In the above-described embodiment, the amount of the object 20 to be weighed on the top cone 3 is detected by the top cone weight sensor 5. However, as another embodiment of the present invention, instead of the weight sensor, above the top cone 3. For example, an ultrasonic type level detector is provided, and the level detector detects the amount of the object 20 on the top cone 3 and controls the amount of the object 20 on the top cone 3. Also good.

DESCRIPTION OF SYMBOLS 1 Supply apparatus 3 Top cone 4 Main feeder 5 Top cone weight sensor 6 Linear feeder pan 7 Weighing object sensor 8 Linear feeder 9 Control device 10 Weight sensor 12 Supply hopper 13 Weighing hopper 15 Packaging machine 16 CPU part 20 Weighing object

Claims (6)

A plurality of transport units for transporting an object to be weighed and dropping and discharging from the transport end;
A plurality of discharge units that are arranged corresponding to each transport unit, hold the objects to be discharged from the transfer end, and drop and discharge the held objects to be weighed;
A plurality of measuring units that are arranged corresponding to the respective discharging units, hold the objects to be discharged from each discharging unit, and measure the weight of the held objects to be weighed;
A combination comprising a calculation control unit that performs a combination calculation based on the weight of an object to be weighed after a stable time measured by the measurement unit, and performs a conveyance control of each conveyance unit and a discharge control of each discharge unit A scale,
A weighing object sensor for detecting a weighing object at each conveyance end of each conveyance unit ;
The arithmetic control unit, based on the detection output of the weighing object sensor, extends the stabilization time for the weighing unit when the weighing object is thrown into the weighing unit.
A combination weigher characterized by that. The arithmetic control unit determines whether or not there is an object to be weighed after the weighing unit based on the detection output of the object sensor and the discharge control timing of the discharge unit, and is delayed from the weighing unit. When it is determined that there is an object to be weighed, the stabilization time for the determined weighing unit is extended.
The combination weigher according to claim 1. The plurality of transport units are a plurality of vibration feeders that transport the objects to be weighed supplied from the dispersion unit by vibration,
The plurality of discharge units are a plurality of supply hoppers that discharge the held objects to be measured and supply the measured items to the measurement unit.
The plurality of weighing units are a plurality of weighing hoppers for weighing the weight of an object to be weighed by a weight sensor,
The arithmetic control unit controls the driving of the vibration feeder and also controls the opening and closing of the gate for discharging the supply hopper.
The combination weigher according to claim 1 or 2. When the operation control unit shifts the discharge gate of the supply hopper from a closed state to an open state, a detection output of the object sensor for detecting an object to be weighed at the transport end of the vibration feeder is When the closed state is detected, the object to be weighed is detected, and when the object is moved to the non-detected state where the object to be weighed is not detected. It is determined that the weighing object has fallen and passed through the supply hopper in which the discharge gate is opened, and is put into the weighing hopper with a delay.
The combination weigher according to claim 3 . The arithmetic control unit, according to the time from when the discharge gate of the supply hopper is shifted to the open state to when the detection output of the object sensor shifts to the non-detection state, Extend the stabilization time,
The combination weigher according to claim 4. The arithmetic control unit drives the vibration feeder for a set time to convey an object to be weighed, and the detection output of the object sensor for detecting the object to be weighed at the conveyance end of the vibration feeder is When the vibration feeder is driven for the set time, the vibration feeder is further driven when the non-detection state in which the object is not detected is not shifted to the detection state in which the object is detected. ,
The combination weigher according to any one of claims 3 to 5 .

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