JP4927326B2 - Combination scale - Google Patents

Description

  The present invention relates to a combination weigher. More specifically, the present invention relates to a combination weigher that calculates a weighing weight using a decrease in the weight of an object to be weighed held in a weighing feeder.

As a conventional combination weigher including a plurality of weighing hoppers and a plurality of memory hoppers, there are the following. (For example, refer to Patent Document 1). FIG. 15 shows a schematic configuration of this conventional combination weigher. As shown in FIG. 15, the conventional combination weigher includes the same number of weighing hoppers, weight sensors, and memory hoppers. The weight sensor detects the total weight of the weighing hopper and the object to be weighed held by the weighing hopper. Then, the weight of the object to be weighed held by the weighing hopper is calculated from the increase in the detected weight value before and after the object to be weighed is supplied to the weighing hopper. All the objects to be weighed held by the weighing hopper are put into the memory hopper from the corresponding weighing hopper. The weight of the object to be weighed held by the memory hopper is assumed to be the total weight of the object to be weighed held by the weighing hopper before being put in. Then, the total weight is calculated by variously combining the weights of the objects to be weighed held by the weighing hopper and the memory hopper, and the most suitable combination is determined in relation to the combination target weight.
JP 2003-207383 A

  Here, in the conventional combination weigher, after the weighing object is supplied to the weighing hopper, the weight sensor detects the total weight of the weighing object held by the weighing hopper and the weighing hopper. When the object to be weighed is supplied, the weighing hopper receives an impact due to the collision of the object to be weighed. Due to this impact, the detection value of the weight sensor becomes unstable for a while after the supply. Such an apparent load caused by an impact is called an impact load. If the impact load is large, it takes a long time for the detected weight value to stabilize. Therefore, in order to accurately detect the weight of the object to be weighed in the weighing hopper, a sufficient time must be secured (hereinafter, the time until the weight detection value is stabilized is referred to as a stable time). For this reason, there has been a problem that the time required for one weighing cycle becomes long.

  In addition, the conventional combination weigher requires the same number of weighing hoppers as the memory hopper. Therefore, in order to increase the number of hoppers used for the combination, it is necessary to install a large number of weighing hoppers, which increases the size of the device. When the device becomes large, the distance from the weighing hopper or the memory hopper to the packaging machine becomes long. Therefore, it takes a long time until the object to be weighed is discharged from the weighing hopper or the memory hopper until it finally enters the packaging machine. For this reason, there has been a problem that the time required for one weighing cycle becomes long.

  The present invention has been made to solve the above-described problems. That is, the first problem to be solved by the present invention is to provide a combination weigher capable of high-speed weighing by shortening the stabilization time while maintaining high weighing accuracy. A second problem to be solved by the present invention is to provide a combination weigher that enables high-speed weighing by downsizing the apparatus while maintaining high weighing accuracy.

  In combination weighing, generally, an object to be weighed is supplied to a weighing hopper with a target of 1 / M (M is an integer) of a target value of a final discharge amount (hereinafter, combination target weight). Next, the weight of the object to be weighed held by the weighing hopper is calculated from the increment of the weight detection value and stored. When the downstream memory hopper is empty, the weighing hopper inputs the entire amount of the object to be weighed into the memory hopper. The weight of the weighing object held by the memory hopper is equal to the weight of the weighing object held by the weighing hopper immediately before and stored. Next, the total of the weights (hereinafter referred to as “combined weights”) obtained by variously combining the weights of the objects to be weighed (hereinafter referred to as measured weights) held in the respective weighing hoppers and the respective memory hoppers is calculated. A weighing hopper that provides the most suitable combination weight in relation to the combination target weight (for example, the one closest to the combination target weight or the combination weight exceeding the combination target weight and the one closest to the combination target reception). And a combination of memory hoppers (hereinafter referred to as an optimal combination). Finally, the objects to be weighed are discharged from the weighing hopper and the memory hopper participating in the optimum combination.

  In such an operation, it is necessary to detect the weighed weight before calculating the combined weight. In the conventional combination weigher, after the object to be weighed is supplied to the weighing hopper, the weighed weight is detected by using the increment of the weight detection value. In such a method, the impact load generated in the weighing hopper increases due to the fall of the object to be weighed. Therefore, in order to detect the weighing weight with high accuracy, it is necessary to take a sufficient stabilization time. On the contrary, if the combination weight is calculated without passing the stabilization time, the error becomes large.

  The inventors of the present application have found that if the weight is calculated using the “decrease” instead of the “increase” of the weight detection value, the necessary stabilization time is extremely shortened. That is, the combination weigher according to the present invention includes a weighing feeder and a memory hopper. The weighing feeder inputs a part of the object to be weighed supplied from the upstream to the downstream memory hopper. Next, using the amount of decrease in the total weight of the weighing object held by the weighing feeder and the weighing feeder before and after the charging (hereinafter referred to as the total weight), the weight of the weighing object loaded into the memory hopper, that is, Calculate the weighing weight. Then, the combined weight is calculated using the measured weight.

  With such a configuration and operation, the impact due to dropping occurs only in the memory hopper, and thus does not affect the stable time for weight detection in the weighing feeder. The weighing feeder is only impacted by opening and closing the gate. For this reason, it is possible to keep the impact load generated in the weighing feeder extremely small. Therefore, the stabilization time can be reduced. Therefore, high-speed weighing is possible.

  The weighing feeder puts a part of the object to be weighed supplied from the upstream into the downstream memory hopper. In this respect, it is different from the conventional weighing hopper in which all of the objects to be weighed supplied from the upstream are thrown into the downstream.

In order to solve the above-described problems, a combination weigher according to the present invention includes a weighing feeder that holds an object to be weighed and a part thereof, a weight of the object to be weighed held by the weighing feeder, and a weight of the weighing feeder. A weight sensor that detects a total weight, a memory hopper that holds and discharges an object to be weighed from the weighing feeder, a detection value of the total weight by the weight sensor, the weighing feeder and the A control board for controlling the memory hopper, and using the decrease in the total weight before and after the weighing object is loaded from the weighing feeder to the memory hopper, the weight of the weighing object loaded into the memory hopper calculate some metric weight, as well as selecting the memory hoppers which participate in the optimal combination with the metering weight, the memory hoppers corresponding is empty While the serial metering feeder turns on the objects to be weighed to the memory hopper, and supplies the objects to be weighed to the weighing feeder the memory hoppers corresponding is not empty.

Thereby, the impact load on the weighing feeder at the time of detecting the total weight can be reduced. Therefore, the stabilization time can be shortened. In addition, the input of the objects to be weighed into the memory hopper and the supply of the objects to be weighed to the weighing feeder can be performed independently for each weighing feeder in parallel. Therefore, the time required for one weighing cycle can be shortened. That is, high-speed weighing is possible.

Also, the weight before charging, which is the total weight before the objects to be weighed from the weighing feeder to the memory hopper, and the charging, which is the total weight after the objects to be weighed from the weighing feeder to the memory hopper are loaded. A value obtained by adding a correction value to the difference from the rear weight may be used as the measured weight .

  Thereby, the stable weight can be predicted before the stable time elapses. Therefore, the combined weight can be calculated without passing the stabilization time and without reducing the accuracy of the weighing weight. Therefore, the time required for one weighing cycle can be shortened. That is, high-speed weighing is possible.

In addition, the correction value may be calculated using a stable weight that is the total weight after a predetermined time has elapsed after the object to be weighed is loaded from the weighing feeder into the memory hopper .
Further, the difference from the stable weight predicted from the time change of the detection value of the weight sensor may be used as the correction value.

  Thereby, a correction value reflecting the stable weight can be obtained. For this reason, the stable weight can be accurately predicted before the stable time elapses. Therefore, the combined weight can be calculated without passing the stabilization time and without reducing the accuracy of the weighing weight. Therefore, the time required for one weighing cycle can be shortened. That is, high-speed weighing is possible.

Further, the difference between the post-input weight and the stable weight may be used as the correction value .

  Thereby, the correction value reflecting the stable weight can be obtained by a simple method. For this reason, the stable weight can be accurately predicted before the stable time elapses. Therefore, the combined weight can be calculated without passing the stabilization time and without reducing the accuracy of the weighing weight. Therefore, the time required for one weighing cycle can be shortened. That is, high-speed weighing is possible.

Further, an average value of the difference between the weight after charging and the stable weight may be used as the correction value .

  Thereby, the weighing weight can be accurately predicted. Therefore, the combined weight can be calculated without passing the stabilization time and without reducing the accuracy of the weighing weight. Therefore, the time required for one weighing cycle can be shortened. That is, high-speed weighing is possible.

Further, the weight before charging, which is the total weight before the objects to be weighed from the weighing feeder to the memory hopper, and after a certain time has elapsed after the objects to be weighed from the weighing feeder to the memory hopper The difference from the stable weight which is the total weight may be used as the measured weight .

  Thereby, the measurement weight can be measured accurately. In addition, since the decrease in the total weight is used as the weighing weight, the stabilization time is short. Therefore, the time required for one weighing cycle can be shortened without reducing the accuracy of combination weighing. That is, high-speed weighing is possible.

A plurality of the memory hoppers may be provided for one weighing feeder .

  Thereby, the number of weighing feeders can be greatly reduced with respect to the number of memory hoppers. Therefore, the apparatus can be reduced in size. This shortens the distance from the memory hopper to the packaging machine. Therefore, the time required for one weighing cycle can be shortened. That is, high-speed weighing is possible.

In addition, an input hopper for supplying an object to be weighed to the weighing feeder is provided, and an object to be weighed is not put into the memory hopper from an insufficient remaining amount weighing feeder that is the weighing feeder in which the total weight is a certain weight or less, The charging hopper may supply an object to be weighed to the weighing-deficient weighing feeder .

  Thereby, the amount of objects to be weighed into the memory hopper will not be insufficient. Therefore, the accuracy of combination weighing is improved.

In addition, when the weighing feeder puts an object to be weighed into the memory hopper, an already loaded amount that is the amount of the object to be weighed that has been thrown from the weighing feeder into the memory hopper is transferred from the weighing feeder to the memory hopper. As the input target amount, which is a control target value of the amount of an object to be input, approaches the input target amount, the input speed, which is the amount of the object to be weighed input to the memory hopper by time, may be reduced .

  Thereby, the impact load on the weighing feeder at the time of detecting the total weight can be greatly reduced. Therefore, the stabilization time can be further shortened. Therefore, the time required for one weighing cycle can be further shortened. That is, high-speed weighing is possible.

In addition, when the weighing feeder puts an object to be weighed into the memory hopper, an already loaded amount that is the amount of the object to be weighed that has been thrown into the memory hopper from the weighing feeder and an amount that has been thrown into the memory hopper from the weighing feeder When the difference from the input target amount that is the control target value of the amount of the object to be weighed approaches zero, the input speed may be kept constant.
Further, an obstacle may be provided in the weighing feeder, between the memory hopper corresponding to the weighing feeder, or in the upper part of the memory hopper .

  Thereby, it can prevent that a to-be-measured object mixes in the memory hopper different from the memory hopper which should be thrown in. Therefore, it becomes possible to accurately grasp the measured weight. Therefore, the accuracy of combination weighing is improved.

A movable flow path may be provided between the weighing feeder and the memory hopper .

  Thereby, it can prevent that a to-be-measured object mixes in the memory hopper different from the memory hopper which should be thrown in. Therefore, it becomes possible to accurately grasp the measured weight. Therefore, the accuracy of combination weighing is improved.

Further, the weighing feeder may be provided with a gate, and when the weighing feeder puts an object to be weighed into the memory hopper, a portion where the gate is opened may be made smaller than half .

more than

  Thereby, it can prevent that a to-be-measured object mixes in the memory hopper different from the memory hopper which should be thrown in. Therefore, it becomes possible to accurately grasp the measured weight. Therefore, the accuracy of combination weighing is improved.

  The present invention has the configuration as described above, and has an effect that it is possible to provide a combination weigher that enables high-speed weighing by shortening the stabilization time while maintaining high weighing accuracy. In addition, there is an effect that it is possible to provide a combination weigher that enables high-speed weighing by downsizing the apparatus while maintaining high weighing accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a diagram showing an example of a schematic configuration in a cross section in the vertical direction of the combination weigher according to Embodiment 1 of the present invention. The arrow in the figure indicates the moving direction of the object to be weighed. Hereinafter, the schematic configuration of the combination weigher according to the present embodiment will be described with reference to FIG. This combination weigher has a feeding hopper 1 at its upper end. The lower portion of the charging hopper 1 is branched into a plurality of paths 16 directed downward on the outer periphery. The bottom surface of the charging hopper 1 has a gentle conical surface that is convex upward in the vertical direction so that the object to be weighed falls on the path 16 according to gravity. An outlet 17 is provided at the lower end of the path 16. The cut gate 2 is disposed at the outlet 17. The cut gate 2 has a door whose opening degree and opening time can be adjusted so that the amount of the object to be weighed supplied downstream from the outlet 17 can be adjusted. Below the cut gate 2, the weighing feeder 3 is disposed at a position where the object to be weighed supplied from the outlet 17 can be received. Each weighing feeder 3 is connected to a weight sensor 4 that detects the total weight (hereinafter, total weight) of the weighing objects held by the weighing feeder 3 and the weighing feeder 3. The weighing feeder 3 is configured so as to hold an object to be weighed supplied from the path 16 as necessary and to input it downstream. Below the weighing feeder 3, a memory hopper 5 is disposed at a position capable of receiving an object to be weighed introduced from the weighing feeder 3. Below the memory hopper 5, a collecting chute 6 for collecting and discharging the objects to be weighed discharged from the memory hopper 5 is disposed. The collecting chute 6 is formed in a hollow truncated cone shape whose radius decreases downward, and has a discharge port 18 at the lower end. A wrapping machine (not shown) is provided below the collective chute 6 so that the objects to be weighed discharged from the discharge port 18 can be received and packaged. The center portion of the charging hopper 1 is supported by a hollow center column 7 extending in the vertical direction. The center column 7 has a leg portion 7a for grounding at a lower portion thereof. The weight sensor 4 is accommodated in the center column 7.

  FIG. 2 is a block diagram showing an example of the hardware configuration of the combination weigher according to Embodiment 1 of the present invention. FIG. 3 is a block diagram showing an example of the configuration of the control system of the combination weigher according to Embodiment 1 of the present invention. Hereinafter, the hardware and control system of the combination weigher according to the present embodiment will be described with reference to FIGS. 2 and 3.

First, the hardware will be described below. As shown in FIG. 2, the hardware of the combination weigher according to the present embodiment includes a charging hopper 1 that divides a flow of an object to be weighed from the upstream into N pieces (N is a natural number of 2 or more) and supplies it downstream. receiving and N cut gate 2 ₁ to 2 _N passing the objects to be weighed to appropriate downstream supplied from hopper 1, the objects to be weighed which have been supplied through the cut gate 2 ₁ to 2 _N, to introduce to the downstream N weighing feeders 3 _{1 to} 3 _N , N weight sensors 4 ₁ to 4 _{N for} detecting the total weight corresponding to the weighing feeders 3 _{1 to} 3 _N , respectively, and weighing feeders 3 _{1 to} 3 _{N are} inserted. and N memory hoppers 5 ₁ to 5 _N to discharge objects to be weighed to to receive downstream respectively, are gathered to be weighed which have been discharged from the memory hoppers 5 ₁ to 5 _N, discharged into unillustrated packaging machine With collective shoot 6 To have. In addition, the arrow in a figure shows the direction through which a to-be-measured object flows.

In the present embodiment, the charging hopper 1 has one inlet and N outlets 17, and the outlets 17 are provided with cut gates 2 ₁ to 2 _N. Each of the cut gates 2 _{1 to} 2 _N and the weighing feeders 3 _{1 to} 3 _N is provided with a door so that the opening degree and the opening time can be individually adjusted. The memory hoppers 5 _{1 to} 5 _N are each provided with a door so that only selected ones can discharge an object to be measured downstream.

Here, the weighing feeders 3 _{1 to} 3 _N in the present embodiment are configured to be capable of adjusting the input amount to the downstream by providing the fan-shaped gate 13. However, the weighing feeder does not necessarily need to be a feeder having a fan-shaped gate 13; for example, a belt feeder, a disc feeder, a screw feeder, a rotary feeder, an auger, a pinch valve, a wing feeder, a slat valve, a roll feeder, a capacity type It may be a feeder or the like. As the weighing feeder, any feeder may be used as long as it can detect the weight of the object to be weighed by the weight sensor and can adjust the input amount to the downstream.

Next, the control system will be described below. As shown in FIG. 3, the control system of the combination weigher according to the present embodiment includes N weight sensors 4 ₁ to 4 _N that detect total weights corresponding to the weighing feeders 3 _{1 to} 3 _N , and a control board. 8, input means 9, and output means 10. Further, from the control substrate 8, so that also transmit a signal to the cut gate ₂ 1 to 2 _N, measuring feeder ₃ 1 to 3 _N and the memory hoppers ₅ 1 to 5 _N. In addition, the arrow in a figure shows the direction where a signal is transmitted.

In the present embodiment, for example, load cells are used for the weight sensors 4 ₁ to 4 _N. For example, a microcomputer is used for the control board 8. As the input means 9, for example, a keyboard or the like is used. As the output means 10, for example, a liquid crystal display or the like is used. The input unit 9 and the output unit 10 may be configured as a single input / output unit using a touch panel or the like.

Hereinafter, the configuration of the control board 8 will be described. FIG. 4 is a block diagram showing a schematic configuration of the control board 8. The control board 8 includes a control unit 11 and a storage unit 12. For example, a CPU is used as the control unit 11. For the storage unit 12, for example, an internal memory is used. The control unit 11 and the storage unit 12 are connected to each other. Further, the control unit 11 receives signals from the weight sensors 4 ₁ to 4 _N and the input means 9, and sends signals to the cut gates 2 ₁ to 2 _N , the weighing feeders 3 _{1 to} 3 _N, and the memory hoppers 5 _{1 to} 5 _N. Send. In addition, the arrow in a figure shows the direction where each signal is transmitted.

Next, the operation of the control board 8 will be described with reference to FIG. From the input means 9, parameters indicating conditions and the like used for selecting the optimum combination, a program used for calculation, and the like are input to the control unit 11. The control unit 11 stores the received parameters, programs, and the like in the storage unit 12. The stored parameters, programs, and the like are displayed on the output means 10 as necessary and confirmed by the operator. The control unit 11 also receives weight detection signals from the weight sensors 4 ₁ to 4 _N. The control unit 11 processes the received detection signal using software stored in the storage unit 12, and based on the result, the cut gates 2 ₁ to 2 _N , the weighing feeders 3 _{1 to} 3 _N and the memory hopper 5 _{1 to} 5 A control signal is transmitted to _N. By the above operation, the control board 8 feed cut gate ₂ 1 to 2 _N, measuring feeder ₃ 1 to 3 _N and the memory hoppers ₅ 1 to 5 _N, respectively, on, detecting the weight of the objects to be weighed to be discharged, controlling Run the combination weigher.

  Next, the outline of the operation of the combination weigher according to the present embodiment having the above-described configuration will be described with reference to FIG. The combination target weight is input to the control board 8 via the input means 10 by the operator. The input combination target weight is displayed on the output means 8 and confirmed by the operator.

  The object to be weighed is supplied from upstream, and an appropriate amount is secured in the charging hopper 1 by a level sensor (not shown). The objects to be weighed in the charging hopper 1 fall along the path 16 according to gravity and are guided to N outlets 17. The supply of the object to be weighed from the outlet 17 is adjusted by the cut gate 2. The object to be weighed is fed from the cut gate 2 through the weighing feeder 3 to the memory hopper 5. Next, the total (hereinafter, combined weight) of the weights (hereinafter, measured weight) of the objects to be weighed in the memory hopper 5 when a plurality of memory hoppers 5 are combined is calculated. Next, using the combination weight, a combination of memory hoppers to be an optimum combination is selected, and the objects to be weighed are discharged from the memory hoppers participating in the optimum combination. Thereafter, the objects to be weighed are discharged to the packaging machine through the collecting chute 6.

  Note that an object to be weighed is fed from the weighing feeder 3 to the empty memory hopper. The objects to be weighed are supplied from the input hopper 1 to the weighing feeder 3 as needed so that the objects to be weighed in the weighing feeder 3 are not short. That is, the weight of the object to be weighed in the weighing feeder 3 does not become zero.

  In the combination weigher according to the present embodiment that performs the general operation as described above, a feature is that the weight to be used for calculating the combination weight is calculated using the decrease in the total weight. Thereby, it is not necessary to take a stable time in the weighing cycle, and the weighing speed can be greatly increased.

  FIG. 5 is a flowchart showing an example of an operation program of the control board 8 in the present embodiment. Hereinafter, with reference to FIG. 5, an operation that is a feature of the combination weigher according to the present embodiment will be described along the flow of the operation.

  First, the total weight of each weighing feeder 3 is detected by the weight sensor 4, and it is determined whether or not it is below a certain weight (step S1).

  In step S1, for the weighing feeder 3 for which it is determined that the total weight does not fall below a certain weight, it is determined whether or not the corresponding memory hopper 5 is empty (step S2).

  For the weighing feeder 3 in which it is determined in step S2 that the corresponding memory hopper 5 is empty, the value of the pre-loading weight Wpre is updated with the detected value of the total weight (step S3).

  Next, a part of the object to be weighed held in the weighing feeder 3 is put into the corresponding memory hopper 5 (step S4).

  Next, the total weight is detected by the weight sensor 4 and stored as a post-injection weight Wpost (step S5).

  Next, a value (Wpre-Wpost + C) obtained by adding the correction value C to the difference between the pre-loading weight Wpre and the post-loading weight Wpost is stored as the weighing weight W of the corresponding memory hopper 5 (step S6).

  In addition, an object to be weighed is supplied to the weighing feeder 3 in which it is determined in step S1 that the total weight is below a certain weight (step S13). Then, the weighing feeder 3 waits until the combined weight is calculated (step S7).

  In step S2, the weighing feeder 3 determined that the corresponding memory hopper 5 is not empty is not loaded with the object to be weighed into the corresponding memory hopper 5. Then, the weighing feeder 3 is left as it is, and is put on standby until the combined weight is calculated (step S7).

  Next, a combination weight is calculated using each weighed weight W, and an optimum combination is determined (step S7).

  Next, the objects to be weighed are discharged from the memory hoppers 5 (hereinafter referred to as selected memory hoppers) participating in the optimum combination, and the corresponding weighing weight W is set to zero (step S8). The discharged objects to be weighed are discharged to the packaging machine through the collecting chute 6.

  Next, the total weight of each weighing feeder 3 is detected and stored as a stable weight Wstab (step S9).

  Next, it is determined for each weighing feeder 3 whether or not an object to be weighed has been supplied from the input hopper 1 in the current weighing cycle (whether it has passed through step S13) (step S10).

  For the weighing feeder 3 determined to be negative in step S10, the correction value C is updated by the difference (Wstab−Wpost) between the stable weight Wstab and the post-injection weight Wpost (step S11).

  Next, the weighing weight W of the corresponding memory hopper 5 is updated by the difference (Wpre−Wstab) between the pre-loading weight Wpre and the stable weight Wstab (step S12).

  Thereafter, the next weighing cycle is started (step S1).

  Note that the weighing feeder 3 determined to be good in step S10 is kept waiting until the next weighing cycle (step S1) without updating the correction value C and the weighing weight W.

  Further, in the present embodiment, the control board 8 stores whether or not the weighing hopper 5 corresponding to each weighing feeder 3 has received the weighing object after the weighing object is finally discharged. And based on the memory | storage, determination of step S2 is performed.

  In the present embodiment, the operation from step S1 to the next step S1 is referred to as one weighing cycle.

  In each weighing cycle, the operations from step S1 to step S13 are performed independently and in parallel for each weighing feeder 3 in parallel. That is, the determination in step S1 and the operation from step S7 to step S9 are performed in parallel for all the weighing feeders 3.

  With the above operation, the combination weigher according to the present embodiment performs combination weighing using the decrease in the total weight corresponding to each weighing feeder 3 as the weighing weight W. The impact generated by throwing the object to be measured downstream is much smaller than the impact receiving the object to be weighed. Therefore, even if the stabilization time is not provided or shortened, it is possible to obtain a weighing weight with little error. Therefore, the time required for one weighing cycle can be greatly reduced. Therefore, high-speed weighing is possible.

  FIG. 6 is a diagram showing the timing of each step when the combination weigher of the present embodiment is operated according to the flowchart of FIG. Here, A in FIG. 6 shows a case where the weighing feeder 3 is sufficiently filled with the object to be weighed and is empty because the corresponding memory hopper 5 has been selected in the previous weighing cycle. B in FIG. 6 shows a case where the object to be weighed is supplied because the object to be weighed is not sufficiently contained in the weighing feeder 3. C in FIG. 6 indicates a case where the weighing object is sufficiently contained in the weighing feeder 3 and the weighing object is contained in the previous weighing cycle without selecting the corresponding memory hopper 5.

  As shown in FIG. 6, in each weighing cycle, first, it is determined whether each weighing feeder 3 belongs to A, B, or C (step S1 and step S2). Thereafter, in the weighing feeder 3 of A, the object to be weighed is put into the memory hopper (steps S3 to S6). Let the start time of this step be t1. An object to be weighed is supplied from the feeding hopper 1 to the weighing feeder 3 of B (step S13). The C weighing feeder 3 stands by without performing a specific operation.

  Next, the combination weight is calculated (step S7). Let the start time of this step be t3. Further, the object to be weighed is discharged from the selected memory hopper (step S8). Let the start time of this step be t4. Further, the stable weight Wstab is detected, and the weighted weight W and the correction value C are updated (Steps S9 to S12). Thereafter, the next metering cycle is started. Thus, the time required for one weighing cycle can be shortened by performing the operations from step S3 to step S6 and the operation of step S13 independently for each weighing feeder 3 in parallel.

  Here, the correction value C will be described. FIG. 7 is a schematic diagram showing changes in the weight of the object to be weighed in the memory hopper 5 and the corresponding detection value of the weight sensor 4 when the weighing feeder 3 is inserted into the memory hopper 5. FIG. 7A shows a case where the memory hopper 5 is not selected, and FIG. 7C shows a case where the memory hopper 5 is selected. Moreover, FIG.7 (b) shows the detection value of the weight sensor 4 corresponding to Fig.7 (a), FIG.7 (d) shows the detection value of the weight sensor 4 corresponding to FIG.7 (c).

  t <b> 1 indicates a point in time when an object to be weighed from the weighing feeder 3 to the memory hopper 5 is started. t <b> 2 indicates a point in time when a charging stop command is sent from the control board 8 to the weighing feeder 3. The detected value of the weight sensor 4 at this time becomes Wpost. t3 indicates a point in time when charging from the weighing feeder 3 is completely stopped. t4 indicates the time when the object to be weighed is discharged from the selected memory hopper. t5 indicates a point in time when the detection value of the weight sensor 4 is stabilized. The detection value of the weight sensor 4 at this time is Wstab. t6 indicates a point in time when the weighing feeder 3 starts to put an object to be weighed into the empty memory hopper 5. Here, t2 and t3 do not coincide with each other because the gate of the measuring feeder 3 is actually closed after the signal is sent from the control board 8 to the measuring feeder 3 and the input of the object to be measured is completely stopped. This is because deviation occurs. The time from t3 to t5 is a so-called stable time.

  The control board 8 sets the detected value of the weight sensor 4 at the time of issuing a stop command to the weighing feeder 3, that is, the weight sensor 4 at the time t2, as the post-injection weight Wpost, and the pre-injection weight Wpre that is a detection value of the weight sensor 4 before the input It is convenient to set the difference (Wpre-Wpost) to the weighed weight W. However, the object to be weighed still flows out from the weighing feeder 3 at t2. For this reason, the amount actually put into the memory hopper 5 further increases. Therefore, if the difference between Wpre and Wpost is directly used as the weighing weight W, the error becomes large. On the other hand, if Wstab is used instead of Wpost, the accuracy of the weighing weight W can be increased. However, in this case, the time required for one weighing cycle becomes long. Therefore, the difference between Wstab and Wpost may be used as the correction value C, and a value obtained by adding C to the difference between Wpre and Wpost in advance (Wpre−Wpost + C) may be used as the weighing weight W. Thereby, Wstab can be accurately predicted from Wpost at time t2. Therefore, the error of the weighing weight W can be reduced. Therefore, the accuracy of combination weighing is improved.

  The detected value of the weight sensor 4 at t3 may be the post-input weight Wpost. Alternatively, the detected value of the weight sensor 4 at any point in time from t2 to t5 may be set as the post-input weight Wpost. At any time point, the detected value of the weight sensor 4 at any time point may be used as the post-injection weight Wpost as long as it is a time point before t5 when the stabilization time elapses. Thereby, the weighing weight W can be predicted before the stabilization time elapses. Therefore, the time required for one weighing cycle can be shortened.

  Note that the detected value of the weight sensor 4 after the elapse of the stabilization time is set to the post-input weight Wpost, and the measurement weight W may not be predicted. This is particularly useful when the stabilization time is short. As a result, the weighing weight can be calculated only by the difference between Wpre and Wpost without adding the correction value C.

  Further, the determination of the total weight regarding each weighing feeder 3 may be divided into two stages: whether or not it is below a certain weight 1 and whether or not it is below a certain weight 2 (constant weight 1> constant weight 2). When the total weight is between the constant weight 1 and the constant weight 2, the object to be weighed is supplied to the weighing feeder 3 only when the object to be weighed is in the corresponding memory hopper 5. When the total weight does not exceed the constant weight 2, even if the corresponding memory hopper 5 is empty, it is not put into the memory hopper 5 and the object to be weighed is supplied to the weighing feeder 3. By performing such an operation, an object to be weighed can be supplied to the weighing feeder 3 using a time during which no charging is performed. Therefore, it is difficult to generate a situation in which the objects to be weighed cannot be input because the objects to be weighed in the weighing feeder 3 are small. Then, the probability that the memory hopper 5 is empty at the time of calculating the combination weight is reduced, and the accuracy of combination weighing is improved.

  Further, in the present embodiment, the timings of loading into the memory hopper 5 (step S3 to step S6) and supplying the object to be weighed to the weighing feeder 3 (step S13) are overlapped. However, the time from when the object to be weighed is discharged from the selected memory hopper to when it is discharged to the packaging machine (between t4 and t5), or after the discharge to the packaging machine is finished, the next input to the memory hopper 5 It is good also as supplying a to-be-measured item to the measurement feeder 3 (step S13) by the time until it starts. Thereby, the amount of objects to be weighed into the memory hopper 5 does not become insufficient. Therefore, the accuracy of combination weighing is improved. In addition, it is possible to supply an object to be weighed to the weighing feeder 3 at a timing that does not affect the accuracy of combination weighing. Therefore, the time required for one weighing cycle can be further shortened.

  The amount to be fed into the memory hopper 5 may be finely adjusted by feeding the object to be weighed into the memory hopper 5 while monitoring the total weight. Thereby, the fluctuation | variation range of measurement weight can be made small. Therefore, the accuracy of combination weighing is improved.

  When an object to be weighed is loaded from the weighing feeder 3 to the memory hopper 5, the amount of the weighed object to be weighed (hereinafter referred to as an already loaded amount) is a control target value for the amount to be loaded from the weighing feeder 3 to the memory hopper 5. As the value approaches (hereinafter referred to as the input target amount), the input amount per hour (hereinafter referred to as the input speed) may be reduced. As a result, the momentum of the objects to be weighed and the gate parts in the weighing feeder 3 at the time of stopping the charging (hereinafter referred to as the stopping of the charging) is reduced. Therefore, the impact received by the weighing feeder 3 when the charging is stopped is reduced, and the stabilization time can be shortened. Further, since the charging speed is small immediately before the stoppage of charging, the difference between the pre-loading weight Wpre and the stable weight Wstab is also small, and the correction value C can be reduced. As a result, the accuracy of combination weighing is improved.

  As a method of reducing the input speed as the already input amount approaches the input target amount, for example, the difference between the already input amount and the input target amount (hereinafter, remaining amount) and the input speed may be made proportional. FIG. 8 is a diagram schematically showing a time change of each element in this case. FIG. 8A shows the already charged amount, FIG. 8B shows the detected value of the weight sensor 4, and FIG. 8C shows the charging speed. Wr in FIG. 8 indicates the remaining amount at time t. As shown in FIG. 8C, it can be seen that the charging speed decreases as the remaining amount decreases. By performing such an operation, it is possible to reduce the impact received by the weighing feeder 3 at the time of stopping loading by a simple calculation method.

  As another method of reducing the charging speed as the already charged volume approaches the charging target volume, the power of the remaining amount may be proportional to the charging speed. As a result, the charging speed rapidly decreases as the remaining amount decreases. Therefore, the charging speed at the start of charging can be increased, and the time required for one weighing cycle can be further shortened.

  The method of reducing the charging speed as the already charged amount approaches the charging target amount is not limited to the above, and may be a method that is inversely proportional to the charging time or a method that is inversely proportional to the power of the charging time. In any method, any method may be used as long as the impact received by the weighing feeder 3 at the time of stopping charging is reduced.

  If the input speed is reduced as the already input amount approaches the target input amount, the input speed decreases when the remaining amount approaches zero, and it takes a long time to input a very small amount. There is a case. Therefore, when the remaining amount approaches zero, the charging speed may be kept constant as shown in FIG. Thereby, when the remaining amount approaches zero, the charging speed can be prevented from approaching zero at the same time. Therefore, it is possible to prevent the time required for loading into the memory hopper 5 from becoming long.

  In the present embodiment, the correction value C is updated based on the difference between the stable weight Wstab and the post-throw weight Wpost. However, the difference between the post-injection weight Wpost and the stable weight Wstab may be averaged over a plurality of immediately preceding weighing cycles, and this may be used as the correction value C. Alternatively, the stable weight Wstab may be predicted from the time change of the detection value by the weight sensor, and the Wpost may be corrected accordingly. In any case, any correction may be used as long as the stable weight Wstab is predicted from the post-input weight Wpost using the detection value of the weight sensor 4.

When the difference between the post-injection weight Wpost and the stable weight Wstab is small, the measurement weight W need not be corrected. That is, instead of Wpost−Wpre + C, the weight W may be Wpost−Wpre.
(Embodiment 2)
The second embodiment of the present invention is obtained by increasing the number of memory hoppers corresponding to one weighing feeder from one to a plurality in the configuration of the first embodiment. This makes it possible to further reduce the size of the device and further increase the operation speed.

  FIG. 9 is a diagram showing an example of a schematic configuration when the combination weigher according to the present embodiment is cut in a vertical section. The arrow in the figure indicates the moving direction of the object to be weighed. Hereinafter, the schematic configuration of the combination weigher according to the present embodiment will be described with reference to FIG. In FIG. 9, the same code | symbol is attached | subjected to the component homologous to FIG. In the present embodiment, the number of memory hoppers 5 corresponding to one weighing feeder 3 is increased from 1 to 2 in the first embodiment (FIG. 1) to form a memory hopper 5A and a memory hopper 5B. Therefore, in the combination weigher according to the present embodiment, the components other than the weighing feeder 3 and the memory hoppers 5A and 5B have already been described in the first embodiment, and thus the description thereof is omitted.

  Here, the weighing feeder 3 and the memory hoppers 5A and 5B, which are features of the combination weigher according to the present embodiment, will be described. The weighing feeder 3 is configured so that the object to be weighed supplied from the upstream can be held and input to the downstream as required. Furthermore, the weighing feeder 3 has a configuration in which an object to be weighed can be selectively introduced into each of the two corresponding memory hoppers 5A and 5B. In the present embodiment, the weighing feeder 3 includes a fan-shaped gate 13. In the present embodiment, the rotation axis of the fan-shaped gate 13 is tangential to the vertical center axis of the combination weigher (centered at the intersection of the vertical center axis and the horizontal plane in the horizontal plane that cuts the vertical center axis). It faces the tangential direction of the circle when a circle is drawn. As shown in FIG. 10, the fan-shaped gate 13 can select which memory hopper 5A, 5B is loaded with the object to be measured by opening the inner side or the outer side.

  The weighing feeder 3 in the present embodiment is configured to be able to adjust the input amount to the downstream by providing the fan-shaped gate 13. However, the weighing feeder 3 is not necessarily a feeder provided with a fan-shaped gate 13, and for example, a belt feeder, a disc feeder, a screw feeder, a rotary feeder, an auger, a pinch valve, a wing feeder, a slat valve, a roll feeder, A capacitive feeder or the like may be used. The weighing feeder 3 can detect the total weight (hereinafter referred to as the total weight) of the objects to be weighed held by the weighing feeder 3 and the weighing feeder 3 by the weight sensor 4 and can adjust the amount of downstream input. Any feeder can be used.

  Here, there is a case where the weighing feeder 3 does not include the fan-shaped gate 13 and the input direction of the object to be weighed cannot be selected. Therefore, the movable flow path 14 may be provided between the weighing feeder 3 and the memory hopper 5. FIG. 13 is a schematic diagram illustrating the flow of an object to be weighed from the weighing feeder 3 to the memory hopper 5 when the movable channel 14 is provided. As shown in FIG. 13, by changing the direction of the movable flow path 14, the memory hopper 5 into which the object to be weighed is put can be selected. According to such a configuration, even when three or more memory hoppers are provided for one weighing feeder, there is an effect that a memory hopper into which an object to be weighed can be easily selected.

  Needless to say, even when the fan-shaped gate 13 is provided, the movable channel 14 can be provided. With this configuration, it is possible to more reliably prevent the objects to be weighed from being mixed into different memory hoppers.

  In the present invention, the weighed weight is calculated from the decrease in the total weight. As a premise, all the objects to be weighed in from the weighing feeder 3 need to enter one of the memory hoppers 5A or 5B in discharging each weighing cycle. However, when two corresponding memory hoppers 5A and 5B are close to each other, when the object to be weighed is loaded into one memory hopper 5A or 5B, the other memory hopper 5B or 5A is also weighed. May be mixed. Then, it becomes impossible to obtain an accurate weighing weight. In order to prevent such a situation, an obstacle 15 may be disposed inside the weighing feeder 3, above the memory hoppers 5A and 5B, or between the weighing feeder 3 and the memory hoppers 5A and 5B. The shape of the obstacle 15 may be, for example, a triangular prism (FIG. 11), or may be a plate (FIG. 12). The position, shape, and size of the obstacle 15 are not particularly limited as long as the object to be weighed is prevented from being mixed into the memory hoppers 5B and 5A different from the memory hoppers 5A and 5B to which the object to be weighed is to be put. There may be. By setting it as this structure, mixing of the to-be-measured object to memory hopper 5A, 5B can be prevented.

  The memory hoppers 5 </ b> A and 5 </ b> B are disposed below the weighing feeder 3 at positions where the objects to be weighed inserted from the weighing feeder 3 can be received. In the present embodiment, the memory hopper 5 </ b> A is disposed slightly below the weighing feeder 3, and the memory hopper 5 </ b> B is disposed slightly below the weighing feeder 3. Thereby, when the fan-shaped gate 13 opens outside, the memory hopper 5 </ b> A can receive the entire amount of the objects to be weighed in by the weighing feeder 3. Further, when the fan-shaped gate 13 is opened, the memory hopper 5B can receive the entire amount of the objects to be weighed in by the weighing feeder 3.

  Next, the operation of the combination weigher according to the present embodiment will be described. In addition, since the outline of the flow and operation | movement of a to-be-measured object is the same as that of Embodiment 1, description is abbreviate | omitted. FIG. 14 is a flowchart showing an example of an operation program of the control board 8 in the present embodiment. Hereinafter, with reference to FIG. 14, an operation that is a feature of the combination weigher according to the present embodiment will be described along the flow of the operation.

  First, the total weight of each weighing feeder 3 is detected by the weight sensor 4, and it is determined whether or not it is below a certain weight (step S1).

  In step S1, it is determined whether or not the corresponding memory hopper 5A is empty for the weighing feeder 3 determined that the total weight is not lower than the constant weight (step S2).

  In step S2, for the weighing feeder 3 for which it is determined that the corresponding memory hopper 5A is empty, the value of Wpre is updated with the detected value of the total weight (step S3).

  Next, a part of the object to be weighed held in the weighing feeder 3 is put into the corresponding memory hopper 5A (step S4).

  Next, the total weight is detected by the weight sensor 4 and stored as a post-injection weight Wpost (step S5).

  Next, a value (Wpre−Wpost + C) obtained by adding the correction value C to the difference between the pre-loading weight Wpre and the post-loading weight Wpost is stored as the weighing weight W of the corresponding memory hopper 5A (step S6).

  If it is determined in step S1 that the total weight is less than a certain weight, an object to be weighed is put into the weighing feeder 3 (step S13). Then, the weighing feeder 3 waits until the combined weight is calculated (step S7).

  In step S2, for the weighing feeder 3 for which it is determined that the corresponding memory hopper 5A is not empty, it is determined whether or not the corresponding memory hopper 5B is empty (step S14).

  In step S14, the weighing feeder 3 for which it is determined that the corresponding memory hopper 5B is empty has the same operation as that performed for the empty memory hopper 5A (steps S3 to S6). An object to be weighed into the hopper 5B and a weight W are calculated (steps S15 to S18). Then, the combination weight is calculated (step S7).

  If it is determined in step S14 that the corresponding memory hopper 5B is not empty, the weighing object 3 is not loaded into the memory hoppers 5A and 5B. Then, the weighing feeder 3 is left as it is, and is put on standby until the combined weight is calculated (step S7).

  Next, a combination weight is calculated using each weighed weight W, and an optimum combination is determined (step S7).

  Next, the objects to be weighed are discharged from the memory hoppers 5A and 5B (hereinafter, selected memory hoppers) participating in the optimum combination, and the corresponding weighing weight W is set to zero (step S8). The discharged objects to be weighed are fed into the packaging machine through the collecting chute 6.

  Next, the total weight of each weighing feeder 3 is detected and stored as a stable weight Wstab (step S9).

  Next, it is determined for each weighing feeder 3 whether or not an object to be weighed has been supplied from the loading hopper 1 in the current weighing cycle (step S10).

  In step S10, the correction value C is updated by the difference (Wstab−Wpost) between the stable weight Wstab and the post-injection weight Wpost for the weighing feeder 3 determined not to be supplied (step S11).

  Next, the measured weight W of the corresponding memory hopper 5A, 5B is updated by the difference (Wpre−Wstab) between the pre-loading weight Wpre and the stable weight Wstab (step S12).

  Thereafter, the next weighing cycle is started (step S1).

  Note that, for the weighing feeder 3 determined to have been supplied in step S10, the next weighing cycle is started without updating the correction value C and the weighing weight W (step S1).

  In the present embodiment, the control board 8 stores whether or not the memory hopper 5A or 5B corresponding to each weighing feeder 3 has received the weighing object after the weighing object is finally discharged. . And based on the memory | storage, determination of step S2 and step S14 is performed.

  Note that if the objects to be weighed are sequentially put into both the memory hoppers 5A and 5B, the time required for one weighing cycle becomes longer. In addition, the waiting time of the other weighing feeders 3 and the memory hoppers 5A and 5B becomes longer, and the time efficiency is lowered. Therefore, in the present embodiment, when both of the corresponding memory hoppers 5A and 5B are empty, the object to be weighed is inserted only into the memory hopper 5A, and the memory hopper 5B is left in an empty state. Weight calculation is performed. However, in the case where priority is given to the accuracy of combination weighing, both may move on to calculation of the combination weight after the objects to be weighed are input. Accordingly, the probability that the memory hoppers 5A and 5B are empty at the time of calculating the combination weight is reduced, and the accuracy of combination weighing is improved.

  In the present embodiment, the operation from step S1 to the next step S1 is referred to as one weighing cycle.

  In each weighing cycle, the operations from step S1 to step S18 are performed independently and in parallel for each weighing feeder 3 in parallel. That is, the determination in step S1 and the operation from step S7 to step S9 are performed in parallel for all the weighing feeders 3.

  With the above operation, the combination weigher according to the present embodiment performs combination weighing using the decrease in the total weight corresponding to each weighing feeder 3 as the weighing weight W. The impact generated in the weighing feeder by putting the object to be measured downstream is much smaller than the impact for receiving the object to be weighed that has dropped. Therefore, the stabilization time can be shortened. Alternatively, it is possible to obtain a weighing weight with less error even if the weighing weight is detected without passing the stabilization time. Therefore, the time required for one weighing cycle can be reduced. Furthermore, the combination weigher according to the present embodiment includes two memory hoppers 5A and 5B for one weighing feeder 3. Thereby, the number of the weighing feeders 3 can be reduced with respect to the number of the memory hoppers 5A and 5B. Therefore, the apparatus can be greatly reduced in size. Therefore, the time required for one weighing cycle can be further reduced. As described above, the combination weigher according to the present embodiment enables high-speed weighing.

  Note that the determination of the total weight for each weighing feeder 3 may be divided into two stages: whether or not the weight is below a certain weight 1 and whether or not it is below a certain weight 2 (constant weight 1> constant weight 2). In this case, when the total weight is between the constant weight 1 and the constant weight 2, the object to be weighed is only supplied to the weighing feeder 3 when the object to be weighed is contained in all the corresponding memory hoppers 5A and 5B. Supply. If the total weight does not exceed the constant weight 2, even if any of the corresponding memory hoppers 5A and 5B is empty, the memory hoppers 5A and 5B are not charged, and the weighing feeder 3 is weighed. Supply things. By performing such an operation, an object to be weighed can be supplied to the weighing feeder 3 using a time during which no charging is performed. Therefore, since there are few objects to be weighed in the weighing feeder 3, it becomes difficult to generate a situation in which the objects to be weighed cannot be put into the memory hoppers 5A and 5B. Then, the probability that the memory hoppers 5A and 5B are empty at the time of calculating the combination weight is reduced, and the accuracy of combination weighing is improved.

  In addition, the weighing feeder has a time from when the object to be weighed is discharged from the selected memory hopper to the time when it is discharged to the packaging machine, or when it is discharged from the packaging machine until it starts to be inserted into the memory hoppers 5A and 5B. It is good also as supplying the to-be-measured item to 3. As a result, the amount of objects to be weighed into the memory hoppers 5A and 5B will not be insufficient. Therefore, the accuracy of combination weighing is improved. In addition, it is possible to supply an object to be weighed to the weighing feeder 3 at a timing that does not affect the accuracy of combination weighing. Therefore, the time required for one weighing cycle can be further shortened.

  In the present embodiment, the number of memory hoppers corresponding to one weighing feeder 3 is two. However, the number of memory hoppers corresponding to one weighing feeder 3 may be three or more. Thereby, the number of the weighing feeders 3 can be further reduced. Therefore, the apparatus can be reduced in size.

  The amount to be fed into the memory hoppers 5A and 5B may be finely adjusted by feeding the objects to be weighed into the memory hoppers 5A and 5B while monitoring the total weight. Thereby, the fluctuation | variation range of measurement weight can be made small. Therefore, the accuracy of combination weighing is improved.

  When putting an object to be weighed from the weighing feeder 3 into the memory hoppers 5A and 5B, the charging speed may be reduced as the already charged amount approaches the charging target amount. As a result, the momentum of the objects to be weighed and the gate parts inside the weighing feeder 3 when the charging is stopped is reduced. Therefore, the impact received by the weighing feeder 3 when the charging is stopped is reduced, and the stabilization time can be shortened. Therefore, high-speed weighing is possible. Further, since the charging speed is small immediately before the stoppage of charging, the difference between the pre-loading weight Wpre and the stable weight Wstab is also small, and the correction value C can be reduced. As a result, the accuracy of combination weighing is improved.

  As a method of reducing the charging speed as the already charged volume approaches the charging target volume, for example, the remaining amount and the charging speed may be made proportional. Alternatively, the power of the remaining amount may be proportional to the charging speed. The method of reducing the charging speed as the already charged amount approaches the charging target amount is not limited to the above, and may be a method that is inversely proportional to the charging time or a method that is inversely proportional to the power of the charging time. In any method, any method may be used as long as the impact received by the weighing feeder 3 at the time of stopping charging is reduced. Thereby, the charging speed decreases as the remaining amount decreases. Therefore, the charging speed at the start of charging can be increased, and the time required for one weighing cycle can be further shortened.

  When the remaining amount approaches zero, the charging speed may be kept constant as shown in D of FIG. Thereby, when the remaining amount approaches zero, the charging speed can be prevented from approaching zero at the same time. Therefore, it is possible to prevent the time required for loading into the memory hoppers 5A and 5B from becoming long.

  Further, the difference between the post-injection weight Wpost and the stable weight Wstab may be averaged over a plurality of immediately preceding weighing cycles, and this may be used as the correction value C. Alternatively, the stable weight Wstab may be predicted from the time change of the detection value by the weight sensor 4, and the Wpost may be corrected accordingly. In any case, any correction may be used as long as the stable weight Wstab is predicted from the post-input weight Wpost using the detection value of the weight sensor 4.

  When the difference between the post-injection weight Wpost and the stable weight Wstab is small, the measurement weight W need not be corrected. That is, instead of Wpost−Wpre + C, the weight W may be Wpost−Wpre.

  The combination weigher according to the present invention is useful as a combination weigher capable of calculating a combination weight by using a decrease in the weight of an object to be weighed in a measurement feeder as a measurement weight.

It is a figure which shows an example of schematic structure when the combination scale which concerns on Embodiment 1 of this invention is cut in the cross section of a perpendicular direction. It is a block diagram which shows schematic structure of the hardware of the combination weigher which concerns on Embodiment 1 of this invention. It is a block diagram which shows schematic structure of the control system of the combination weigher which concerns on Embodiment 1 of this invention. It is a block diagram which shows schematic structure of the control board 8 of the combination scale which concerns on Embodiment 1 of this invention. It is a flowchart which shows an example of the operation | movement program of the control board 8 of the combination weigher which concerns on Embodiment 1 of this invention. It is a figure which shows the timing of each step at the time of driving the combination scale which concerns on Embodiment 1 of this invention according to the flowchart of FIG. In the combination weigher according to the first embodiment of the present invention, a schematic diagram showing changes in the weight of an object to be weighed in the memory hopper 5 and the corresponding detection value of the weight sensor 4 when the weighing feeder 3 is put into the memory hopper 5. 7 (a) and 7 (b) show the weight of the object to be weighed in the memory hopper 5 and the detected value of the weight sensor 4 when the memory hopper 5 is not selected, FIG. 7 (c). FIG. 7D schematically shows the weight of the object to be weighed in the memory hopper 5 and the detection value of the weight sensor 4 when the memory hopper 5 is selected. In the combination weigher according to the first embodiment of the present invention, when the remaining amount is proportional to the charging speed, the amount already charged (a), the detected value of the weight sensor (b), the time variation of the charging speed (c), It is a figure which shows typically the time change (d) of the injection | throwing-in speed | rate in the case where a charging speed is kept constant when a residual amount approaches zero. It is a figure which shows an example of schematic structure when the combination scale which concerns on Embodiment 2 of this invention is cut in the cross section of a perpendicular direction. It is a schematic diagram which shows schematic structure of the fan-shaped gate 13 in the combination balance which concerns on Embodiment 2 of this invention. In the combination scale which concerns on Embodiment 2 of this invention, it is a schematic diagram which shows the flow of a to-be-measured object when the obstruction 15 has a shape of a triangular prism. In the combination scale which concerns on Embodiment 2 of this invention, it is a schematic diagram which shows the flow of a to-be-measured object when the obstruction 15 has plate shape. It is a schematic diagram which shows schematic structure and operation | movement of the movable flow path 14 in the combination balance which concerns on Embodiment 2 of this invention. It is a flowchart which shows an example of the operation | movement program of the control board 8 of the combination scale which concerns on Embodiment 2 of this invention. It is a block diagram which shows schematic structure of the combination scale described in patent document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input hopper 2 Cut gate 3 Weighing feeder 4 Weight sensor 5 Memory hopper 6 Collective chute 7 Center column 7a Leg part 8 Control board 9 Input means 10 Output means 11 Control part 12 Storage part 13 Fan type gate 14 Movable flow path 15 Obstruction Object 16 Route 17 Exit 18 Discharge port

Claims (13)

A weighing feeder that holds an object to be weighed and throws a part of it,
A weight sensor that detects a total weight that is a sum of the weight of the object to be weighed held by the weighing feeder and the weight of the weighing feeder;
A memory hopper for holding and discharging an object to be weighed from the weighing feeder;
A control board that receives the detected value of the total weight by the weight sensor and controls the weighing feeder and the memory hopper;
Multiple memory hoppers are provided for each weighing feeder,
Using the decrease in the total weight before and after the weighing object is put into the memory hopper from the weighing feeder,
Calculate a weighing weight that is the weight of the object to be weighed put into the memory hopper,
Selecting a memory hopper to participate in an optimal combination using the weighed weight;
The weighing feeder having a total weight greater than a constant weight 1 and corresponding at least one of the memory hoppers empty, and a total weight between the constant weight 1 and a constant weight 2 less than the constant weight 1 and corresponding Any memory that has a total weight between constant weight 1 and constant weight 2 and corresponds while the weighing feeder puts an object to be measured into the memory hopper when at least one of the memory hoppers is empty A combination weigher that feeds an object to be weighed to the weighing feeder in which the hopper is not empty and the weighing feeder whose total weight is less than a constant weight 2.   Weight before charging, which is the total weight before the objects to be weighed from the weighing feeder to the memory hopper, and weight after loading, which is the total weight after the objects to be weighed from the weighing feeder to the memory hopper The combination weigher according to claim 1, wherein a value obtained by adding a correction value to the difference between the weight and the weight is the weight.   3. The combination weigher according to claim 2, wherein the correction value is calculated using a stable weight which is the total weight after a predetermined time has elapsed after the objects to be weighed are put into the memory hopper from the weighing feeder.   The combination weigher according to claim 3, wherein a difference from the stable weight predicted from a time change of a detection value of the weight sensor is used as the correction value.   The combination weigher according to claim 3, wherein a difference between the post-input weight and the stable weight is the correction value.   The combination weigher according to claim 3, wherein an average value of a difference between the post-input weight and the stable weight is used as the correction value.   The total weight before loading the objects to be weighed from the weighing feeder to the memory hopper, and the total after a certain time has elapsed after the objects to be weighed from the weighing feeder to the memory hopper The combination weigher according to claim 1, wherein a difference from a stable weight, which is a weight, is used as the weighing weight.   A charging hopper for supplying an object to be weighed to the weighing feeder; The combination weigher according to claim 1, wherein a hopper supplies an object to be weighed to the shortage measuring feeder.   When the weighing feeder puts an object to be weighed into the memory hopper, an already loaded amount that is the amount of the object to be weighed that has been thrown into the memory hopper from the weighing feeder is thrown into the memory hopper from the weighing feeder. 2. The combination according to claim 1, wherein as the input target amount that is a control target value of the amount of an object to be measured is approached, an input speed that is an amount of an object to be weighed that is input to the memory hopper by the weighing feeder is reduced. Scale.   When the weighing feeder puts an object to be weighed into the memory hopper, an already loaded amount that is the amount of the object to be weighed that has been thrown into the memory hopper from the weighing feeder and a thing that is thrown into the memory hopper from the weighing feeder. The combination weigher according to claim 1, wherein when the difference between the input target amount, which is a control target value of the amount of the measured item, approaches zero, the input speed is kept constant. The combination weigher according to claim 1 , wherein an obstacle is provided in the weighing feeder, between the memory hopper corresponding to the weighing feeder, or in an upper portion of the memory hopper. The combination weigher according to claim 1 , wherein a movable flow path is provided between the weighing feeder and the memory hopper. It said measuring feeder comprises a gate, when the metering feeder turns on the objects to be weighed to the memory hopper, to less than half the partial opening the gate, the combination weigher according to claim 1.

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