JP2012173247A - Weighing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weighing apparatus capable of preventing outflow of an outside product to a succeeding process without reducing responsiveness by detecting occurrence of coil overflow.SOLUTION: The weighing apparatus includes: electromagnetic balance type weighing means 21 having an electromagnetic coil and a coil application part for applying electric power to the electromagnetic coil, holding balance between load by a weighed object W and force generated by a current allowed to flow into the electromagnetic coil, measuring a current value flowing into the electromagnetic coil, and outputting the measured current value as a weighing signal; a coil application voltage detection section 98 for detecting voltage applied to the electromagnetic coil 84; a coil application voltage saturation determination section 99 for determining whether the voltage detected by the coil application voltage detection section 98 is saturated or not; and control means 74, when the coil application voltage saturation determination section 99 determines the saturation of the voltage, for determining that the weighing signal from the weighing means 21 is abnormal.

Description

  The present invention relates to a weighing device that measures quality by weighing an object to be weighed such as meat, fish, processed food, and medicine.

  2. Description of the Related Art Conventionally, in a production line for foods, etc., articles that are incorporated into the production line are sequentially carried in from the front stage, weighed while transporting the carried-in articles, and are removed from the production line by carrying out or sorting to the subsequent stage. A weighing device is used. This type of weighing device has a configuration of an electromagnetic balance type balance, and includes a weighing table, position detecting means for detecting displacement of the weighing table from a predetermined position due to a load change, and a force against the load. An electromagnetic coil to be applied to the weighing platform, a control voltage output device for receiving a detection signal from the position detecting means and outputting a control voltage according to the load, and driving the electromagnetic coil with a current according to the control voltage, And a current conversion circuit that suppresses displacement from the position, and even when there is a sudden input, a technique is known in which the current flowing in the electromagnetic coil is changed quickly following the control voltage. (For example, refer to Patent Document 1).

JP-A-3-77024

  However, in the conventional weighing device, a measurement error may occur due to peripheral vibration. In particular, when a forklift passes or there is suddenly large vibration such as human vibration, a weighing error may occur, and a lightweight product may be weighed as a positive product, and an out-of-system product may flow to the next step. In particular, in an electromagnetic balance-type balance that is often used in lines that require high-speed and high-precision weighing, a coil is used to control the position of the movable part of the balance with electromagnetic force by servo control, and to obtain the amount of operation of the position of the movable scale part Although the current is converted into the weight of the article, when the coil application voltage is saturated with respect to the operation amount due to sudden large vibration, the coil application voltage waveform is clipped and cut off, There was a problem that accurate measurement could not be performed.

  Specifically, as shown in FIG. 5, when the coil applied voltage overflows, the coil applied voltage cannot exceed a predetermined limit and the waveform is clipped. There was a problem that the measured value comes out lighter than the normal value. Here, sudden large vibration is vibration that is 10 to 20 times as large as usual, and in order to set a high limit to cope with such vibration, the electromagnetic coil must be made strong. However, this increases the cost. Therefore, it is necessary to set a limit on the coil applied voltage, and this also sets a limit on the current to the coil.

  Further, for example, it is conceivable to avoid the overflow of the coil application voltage by lowering the gain of the feedback control system of the coil application voltage, but in that case, there is a problem that the responsiveness is lowered.

  In addition, since the circuit that calculates the measurement value of the article from the coil current is designed to cut high frequencies such as natural vibration by a low-pass filter before A / D conversion, the waveform is attenuated by the filter. The coil overflow cannot be detected from the value obtained by A / D converting the coil current, and if the low-pass filter is not inserted, there is a problem that the input range to the A / D conversion unit overflows.

  Therefore, the present invention has been made to solve the above-described conventional problems, and by detecting that a coil overflow has occurred, it is possible to prevent the out-of-system product from flowing to the next process without reducing responsiveness. It aims at providing the measuring device which can be prevented.

  The weighing device according to the present invention includes an electromagnetic coil and a coil application unit that applies electric power to the electromagnetic coil, and balances the load caused by the object to be weighed with the force generated by the current flowing through the electromagnetic coil. An electromagnetic balance type weighing means that measures a current value flowing through the electromagnetic coil and outputs it as a weighing signal; a weighing means that receives the weighing signal and calculates a measured value of an object to be measured; and a measured value calculated by the weighing means And pass / fail judgment criteria for judging pass / fail of the object to be weighed, coil applied voltage detecting means for detecting the voltage applied to the electromagnetic coil, and coil applied voltage detecting means A coil application voltage saturation determination means for determining whether or not the voltage is saturated, and a weighing signal from the weighing means when the coil application voltage saturation determination means determines that the voltage is saturated. Characterized in that and a control means for determining as abnormal.

  With this configuration, when the control means determines that the coil application voltage saturation determination means determines that the voltage is saturated (overflow), it is determined that the weighing signal from the weighing means is abnormal. Can be prevented from flowing out to the next process. In addition, since the coil application voltage saturation determining means detects the overflow of the electromagnetic coil, it is not necessary to lower the gain of the feedback control system of the coil application voltage, and the responsiveness can be prevented from being lowered.

  Therefore, by detecting that the coil overflow has occurred, it is possible to prevent the out-of-system product from flowing into the next process without lowering the responsiveness.

  The measuring device according to the present invention is characterized in that the coil application voltage detection means detects a voltage applied to the electromagnetic coil based on a voltage of a current detection resistor connected in series to the electromagnetic coil. And

  With this configuration, it is possible to prevent the out-of-system product from flowing into the next process without lowering the responsiveness by detecting that the coil overflow has occurred.

  The measuring device according to the present invention is characterized in that the coil application voltage detection means detects the voltage applied to the electromagnetic coil by detecting the output voltage of the coil application unit.

  With this configuration, it is possible to prevent the out-of-system product from flowing into the next process without lowering the responsiveness by detecting that the coil overflow has occurred.

  Further, the weighing device according to the present invention is configured to determine whether the weighing object is carried into and out of the weighing means under a predetermined conveying condition, and the weighing object carried out from the conveying means is determined by the pass / fail judgment means. Sorting means for discharging from the transport means when the measuring means is defective, and the control means determines that the weighing object is discharged when the weighing signal from the weighing means is abnormal. The means is controlled.

  With this configuration, when the coil overflow occurs, it is determined that the weighing signal is abnormal and the object to be weighed is discharged, so it is possible to prevent the out-of-system product from flowing into the next process.

  The present invention can provide a measuring device that can prevent the out-of-system product from flowing into the next process without lowering the responsiveness by detecting the occurrence of coil overflow.

It is a perspective view which shows the outline | summary of the weighing | measuring device which concerns on one embodiment of this invention. It is a block diagram which shows the internal structure of the weighing | measuring device which concerns on one embodiment of this invention. It is a side view which shows the conveyance part of the weighing | measuring device which concerns on one embodiment of this invention. It is a figure which shows the weighing means of the measuring apparatus which concerns on one embodiment of this invention. It is a figure which shows the state of the coil overflow of the conventional measuring device.

  Hereinafter, embodiments of a weighing device according to the present invention will be described with reference to the drawings.

  1 to 4 show an embodiment of a weighing device according to the present invention.

  As shown in FIGS. 1 to 4, the weighing device 1 includes a device main body 2, a transport unit 3, and a carry-in sensor 4. A sorting unit 5 is connected to the subsequent stage of the weighing device 1.

  The weighing device 1 is installed on the downstream side of the belt conveyor 14 constituting a part of the production line, and is to be weighed for meat, fish, processed foods, pharmaceuticals, etc. that are sequentially carried in the direction of arrow A at predetermined intervals. The weight of the object W is measured, and the obtained measurement value is output as a measurement result. Furthermore, it compares with the reference value of the upper limit and the lower limit of the preset weight, respectively, determines whether or not the obtained measurement value is within the range of the reference value, makes the one in the range a non-defective product, and out of the range It may be determined whether the product is defective or not, or the weight rank is determined corresponding to a plurality of reference values. In addition, the measurement result, the pass / fail determination result, and the weight rank determination result are displayed on the display unit 10 and are output to the selection unit 5 connected to the subsequent stage of the weighing device 1. The sorting unit 5 distributes the objects to be weighed W according to the measurement result output from the weighing device 1, the pass / fail determination result, and the weight rank determination result.

  The apparatus main body 2 includes a weighing unit 21, a general control unit 7, a display unit 10, a setting unit 11, and a housing 2a that houses these units.

  The conveyance unit 3 is configured to convey the object W to be weighed in from the belt conveyor 14 in the direction of arrow A under predetermined conveyance conditions. The object to be weighed W is conveyed by being accelerated or decelerated so as to have an optimum speed for measurement by the run-up conveyor 31, further conveyed by the weighing conveyor 32, and the weight is measured by the weighing means 21 while being conveyed. It has become so. The weighing conveyor 32 is configured to convey an object to be weighed according to predetermined conveyance conditions. In addition, the object to be weighed W is further transported to the sorting unit 5 in the subsequent stage after the weighing and is distributed.

  The transport unit 3 includes a running conveyor 31 and a weighing conveyor 32. The run-up conveyor 31 performs the run-up of the object to be weighed W before the object to be weighed W conveyed from the preceding belt conveyor 14 moves to the weighing conveyor 32, and includes two rollers 31a and 31c, And an endless conveying belt 31b wound around the roller. The weighing conveyor 32 is supported by the upper part of the weighing means 21 for weighing the workpiece W, and is composed of two rollers 32a and 32c and an endless conveying belt 32b wound around these rollers. Yes.

  The carry-in sensor 4 is configured by a transmission photoelectric sensor including a pair of light projecting units 4 a and light receiving units 4 b, and is disposed between the run-up conveyor 31 and the weighing conveyor 32. Specifically, the light projecting unit 4a is disposed on the apparatus main body 2 side of the transport belt 32b, and the light receiving unit 4b is disposed on the other side of the transport belt 32b so as to face the light projecting unit 4a. When the object to be weighed W passes between the light projecting part 4a and the light receiving part 4b, the light receiving part 4b is shielded by the object to be weighed, so that it is detected that the carry-in of the object to be weighed W is started. It has become. The detected carry-in start signal is output to the general control unit 7 in the apparatus main body 2.

  The weighing means 21 is a load sensor that supports the weighing conveyor 32 and outputs a weighing signal based on the load of the object to be weighed, has a configuration of an electromagnetic balance type balance, and the object to be weighed W is conveyed by the weighing conveyor 32. During this time, the load applied to the weighing means 21 is measured.

  Specifically, as shown in FIG. 4, the weighing means 21 includes a suspension plate 85 that moves up and down together with the weighing conveyor 32, a parallel spring 86 that suspends the suspension plate 85, and one end fixed to the suspension plate 85. 82, a fulcrum 81 that supports the cage 82, a position sensor 83 that detects the position of the other end of the cage 82, an electromagnetic coil 84 with a magnet 88 that applies a force to the other end of the cage 82, and an electromagnetic A coil application unit 92 that drives the coil 84 and a servo control unit 91 that controls the coil application unit 92 by servo control such as PID control based on a detection signal from the position sensor 83 are provided. Note that one end of the parallel spring 86 is fixed to the suspension plate 85, but the other end is fixed to a common base 87 with the fulcrum 81 and the electromagnetic coil 84, thereby constituting a Roverval mechanism. .

  In the electromagnetic balance type balance as the weighing means 21, the balance of the cage 82 is balanced when there is no load, and when the workpiece W is placed on the weighing conveyor 32, the balance around the fulcrum 81 is lost, and the cage 82 is shown in the right side of the figure. The inclination is detected by the position sensor 83, and a current is passed through the electromagnetic coil 84 so that the inclination is zero, so that the current is proportional to the weight of the object W. The value can be converted to grams. That is, the load generated by the mass of the object W to be measured and the force generated by the current flowing through the magnet 88 and the electromagnetic coil 84 are balanced, and the current value flowing through the electromagnetic coil 84 at this time is measured as the weight of the object W to be inspected. .

  The comprehensive control unit 7 includes a signal processing unit 71, a weighing unit 72, a storage unit 73, a control unit 74, a quality determination unit 76, a mode switching unit 77, a coil application voltage detection unit 98, and a coil application voltage saturation determination unit 99. ing.

  The signal processing means 71 receives the weighing signal from the weighing means 21 and performs signal processing on the basis of predetermined signal processing conditions to output a signal processed signal. The signal processing means 71 converts an analog signal into a digital signal. A D converter is provided. Specifically, the signal processing means 71 has signal-processed only the low-frequency component of the weighing signal using a filter selected from a plurality of low-pass filters of different types and characteristics with respect to the weighing signal from the weighing means 21. It is designed to pass as a signal. The signal processing means 71 may select one low-pass filter or a combination of a plurality of low-pass filters. As this low-pass filter, there are a FIR (Finite Impulse Response) filter and an IIR (Infinite Impulse Response) filter. Here, the FIR filter is a finite impulse response filter that outputs an output for a predetermined time (finite time) when an impulse response waveform is input, and the IIR filter outputs an attenuation waveform of the impulse response waveform infinitely. This is an infinite impulse response filter.

  Here, the FIR filter constitutes a low-pass filter that passes a predetermined low-frequency component with respect to the weighing signal converted into a digital signal by the A / D converter, and uses a simple averaging process or a Kochi window function. Weighted averaging processing is performed. The IIR filter is an analog filter that directly receives a weighing signal (analog weighing signal) from the weighing means 21 and outputs a processed signal to the A / D converter using hardware whose characteristics can be changed, such as a switched capacitor filter. Or a digital filter that receives a digital weighing signal (not shown) from the A / D converter.

  Specifically, as shown in FIG. 4, the signal processing means 71 is detected with a current detection resistor 93 connected in series to the electromagnetic coil 84 in order to detect the current flowing through the electromagnetic coil 84 of the weighing means 21. An amplifier 94 for amplifying the amplified signal, an analog filter 95 for filtering the amplified signal, an A / D converter 96 for digitally converting the filtered signal, and a filter 97 for filtering the digitally converted signal. And.

  The weighing means 72 calculates (measured in grams) the measured value of the object W based on the signal processed signal output from the signal processing means 71. Further, in the weighing means 72, a predetermined reference time Tk has elapsed after the carry-in sensor 4 detects that the object to be weighed W has been carried into the weighing conveyor 32, and the weighing signal from which the weighing signal has been output from the weighing means 21. A measurement value is calculated for the object W. Individual weights calculated by the weighing means 72 are stored in the storage means 73 as calculation data.

The weighing unit 72 performs weighing when a preset reference time Tk has elapsed after the carry-in sensor 4 detects that the workpiece W has been carried into the weighing conveyor 32. Here, the reference time Tk is detected by the loading sensor 4 that the object to be weighed W has started to be loaded onto the weighing conveyor 32, and then the weighing object W is completely transferred to the weighing conveyor 32, and further from the weighing means 21. This means the time required for the output weighing signal to stabilize. Specifically, the reference time Tk is the speed of the weighing conveyor 32 (m / min), the length of the weighing conveyor 32 in the direction of arrow B (mm), and the length of the weighing object W in the direction of arrow B, which is the conveyance direction. (Mm), the size of the workpiece W, the processing capacity of the line, and other conditions. Further, as shown in FIG. 3, the reference time Tk has elapsed, the objects to be weighed W is moved by L ₁ reaches the mass measuring position P _S from the loading start detection position P _O, metering is performed.

  In the weighing means 72, inspection conditions (parameters) such as the measurement range, measurement capability, and inspection accuracy are selected according to the type (particularly size) of the object to be weighed W. Depending on the type of the weighing object W, for example, the measurement range is selected from 6 g to 600 g, and the measurement capability is selected at a maximum of 150 pieces / min. In this case, the reference time Tk per object W is set to a minimum of 400 msec, and the reference time Tk may be 400 msec or more. It is set according to capacity, production and other conditions. Since the reference time Tk is measured in a shorter time as it is closer to 400 msec, the inspection efficiency is increased, and as the distance is longer, the inspection time is longer, but the weighing accuracy is increased because it is stably conveyed on the weighing conveyor 32. Become.

  Further, according to the type of the object to be weighed W, for example, the measurement range is selected from 1 g to 300 g, and the measurement capability is selected at a maximum of 600 pieces / min. If the measurement capacity is 600 pieces / min at the maximum, the measurement time per piece of the object to be weighed W is set to a minimum of 100 msec, and the size of the object to be weighed W, the processing capacity of the line, production, etc. It is set according to the conditions. Since the reference time Tk is measured in a shorter time as it is closer to 100 msec, the inspection efficiency is increased. As the distance is longer, the inspection time is longer, but the weighing accuracy is increased because the weighing conveyor 32 is stably conveyed. In this way, in the weighing means 72, the inspection conditions (parameters) such as the range and capability are selected according to the type of the object to be weighed W.

  The storage means 73 is composed of a storage medium and the like, and the condition parameters including the predetermined transport condition of the object W to be weighed by the weighing conveyor 32 and the predetermined signal processing condition in the signal processing means 71 are the types of the object W to be weighed. It corresponds to memorize. The storage unit 73 stores a conveyance speed and LPF (Low Pass Filter) characteristics corresponding to each type number assigned to each type of the object to be weighed W. Further, the storage means 73 stores a non-defective range for determining the quality of the object W to be weighed. The conveyance speed is the speed of the conveyance unit 3 that conveys the workpiece W, the LPF characteristic indicates what characteristic the low-pass filter is, and the non-defective range is the non-defective product range. This is the range of the weight of the weighing object W. The stored information is stored in advance by a setting operation from the setting unit 11 or connection with an external device. The storage means 73 stores various data such as measurement values and non-defective product determination results.

  The control means 74 reads out a predetermined transport condition and a predetermined signal processing condition from the storage means 73 in accordance with the type of the object to be weighed W, and controls the weighing conveyor 32 and the signal processing means 71, respectively. Further, the transport unit 3 and the signal processing unit 71 are controlled by sequentially switching condition parameters corresponding to a plurality of types stored in the storage unit 73. Further, the control means 74 is configured to drive and control the rotational speed (rpm) of a motor (not shown) so as to control the transport speed of the workpiece W by the transport unit 3.

  The pass / fail judgment means 76 is for judging pass / fail of the object to be weighed W. The pass / fail judgment means 76 is constituted by a judgment circuit and the like, and compares the weight value calculated by the weighing means 72 with the pass / fail judgment criteria to determine the pass / fail of the object W It comes to judge. Specifically, the quality determination unit 76, when receiving the weight signal of the object W output from the weighing unit 72, reads the upper limit value Ga and the lower limit value Gb of the weight stored in advance in the storage unit 73, The calculated weight of the object to be weighed is compared with the upper limit value Ga and the lower limit value Gb, respectively, and whether the weight of the object to be weighed W is within the allowable range determined by the upper limit value Ga and the lower limit value Gb. It is to judge whether.

  The determination result determined by the quality determination unit 76 is output to the display unit 10 and displayed as a non-defective product or a defective product. The determination result is output to the sorting unit 5 connected to the subsequent stage of the weighing device 1 so that the object to be weighed W is sorted as a non-defective product or a defective product. Further, the determination result is output to the storage means 73, and the determination result for each object W is stored.

  The mode switching unit 77 issues a command to the control unit 74 and switches the operation mode of the weighing device 1 between the operation mode and the setting mode. Here, the operation mode is a normal operation mode in which the weighing apparatus 1 performs weighing, weight calculation, and pass / fail judgment of the object to be weighed. The setting mode refers to various parameters for operation in the operation mode. This is an operation mode for confirming whether or not the operation of the operation mode can be performed normally. The mode switching unit 77 switches the operation mode to the setting mode according to an input operation from the setting unit 11 or switches the operation mode to the setting mode at the start of operation of the apparatus.

  The coil application voltage detection unit 98 includes an A / D converter, a comparator, and the like, and detects a voltage applied to the electromagnetic coil 84.

  Specifically, the coil application voltage detection unit 98 detects the voltage applied to the electromagnetic coil 84 based on a signal obtained by amplifying the voltage of the current detection resistor 93 connected in series with the electromagnetic coil 84 by the amplifier 100. ing. The coil application voltage detection unit 98 may detect the voltage applied to the electromagnetic coil 84 by detecting the output voltage of the coil application unit 92.

  The coil application voltage saturation determination unit 99 determines whether or not the voltage detected by the coil application voltage detection unit 98 is saturated (overflow). The coil application voltage saturation determination unit 99 determines that the voltage is saturated, for example, when the voltage exceeds a predetermined threshold.

  When the coil application voltage saturation determination unit 99 determines that the voltage is saturated, the control unit 74 determines that the weighing signal from the weighing unit 21 is abnormal. When the sorting unit 5 is configured as a part of the weighing device 1 and the sorting unit 5 is directly controlled by the control unit 74, the control unit 74 determines that the weighing signal from the weighing unit 21 is abnormal. When this is done, the sorting unit 5 is controlled to discharge the object to be weighed W.

  As shown in FIG. 1, the display unit 10 is provided at the upper end of the apparatus main body 2 on the transport unit 3 side, and is configured by a display device such as a liquid crystal display. When the operation mode of the weighing device 1 is the operation mode, the display means 10 displays the operation state of the weighing device 1, the measured value of the object W, and the pass / fail judgment result, and the operation mode of the weighing device 1 is the setting mode. In this case, display related to parameter setting and operation confirmation is performed. The display unit 10 may be configured as a touch panel in which displayed numbers, characters, and the like are input by a touch operation, and may be configured to be integrated with the setting unit 11.

  The sorting unit 5 is connected to the subsequent stage of the weighing device 1 and includes a sorting mechanism unit 5a and a conveyor belt 5b. The sorting mechanism unit 5a is configured by, for example, an extrusion type sorting mechanism. The sorting mechanism unit 5a only needs to be able to sort good products and defective products, and may be configured by a sorting mechanism such as a flipper mechanism, a dropout mechanism, or an air jet mechanism. The sorting mechanism unit 5a is configured to transfer the workpiece belt W to the workpiece W determined to be defective while the workpiece W transported from the upstream weighing conveyor 32 is being transported in the arrow B direction by the transport belt 5b. 5b is pushed out in the lateral direction and jet air is sprayed, and the defective object W is discharged from the conveying belt 5b and is distinguished from the non-defective object W by sorting. Yes. The conveyor belt 5b is composed of a roller 5c, a roller (not shown) disposed opposite to the roller 5c, and an endless conveyor belt wound around these rollers. The weighing object W is conveyed downstream at a predetermined speed.

  Next, the operation of the weighing device 1 according to the present embodiment will be described.

  The object to be weighed W is conveyed by being accelerated or decelerated so as to have an optimum speed for measurement by the running conveyor 31, and the weight is weighed by the weighing means 21 while being conveyed by the weighing conveyor 32.

  The weighing means 21 calculates the measured value of the workpiece W at a predetermined timing after the delivery of the workpiece W to the weighing conveyor 32 is started. At this time, sudden large vibrations are input to the weighing device 1. Then, the measured value includes an error.

  Therefore, the coil application voltage detection unit 98 detects the voltage applied to the electromagnetic coil 84, the coil application voltage saturation determination unit 99 determines whether or not the detected voltage is saturated, and the voltage is saturated. In the case where it is determined, the control means 74 determines that the weighing signal from the weighing means 21 is abnormal, and controls the sorting unit 5 to discharge the object to be weighed W.

  In the above embodiment, the weighing device 1 is configured to measure the object to be weighed W while being transported. However, in the present invention, the run-up conveyor 31 and the weighing conveyor 32 that convey the object to be weighed W are provided. The present invention can also be applied to a configuration that does not include.

  As described above, the weighing device 1 according to the present embodiment includes the electromagnetic coil 84 and the coil application unit 92 that applies electric power to the electromagnetic coil 84, and the load caused by the object W and the electromagnetic coil 84 are used. The force generated by the flowing current is balanced, and at this time, the value of the current flowing through the electromagnetic coil 84 is measured and output as a weighing signal, and the electromagnetic balancing type weighing means 21 and the weighing value of the object W to be weighed are received. The weighing means 72 to be calculated, the quality value calculated by the weighing means 72 and the pass / fail judgment criteria are compared, and the pass / fail judgment means 76 for judging pass / fail of the object W to be measured, and the voltage applied to the electromagnetic coil 84 are detected. The coil application voltage detection unit 98, the coil application voltage saturation determination unit 99 that determines whether the voltage detected by the coil application voltage detection unit 98 is saturated, and the coil application voltage saturation determination unit 99 There when determined to be saturated, and further comprising a, a control means 74 determines the weighing signal is abnormal from the weighing means 21.

  With this configuration, the control means 74 determines that the weighing signal from the weighing means 21 is abnormal when the coil application voltage saturation determination unit 99 determines that the voltage is saturated (overflow). It is possible to prevent the product W from being erroneously determined as a non-defective product and flowing out to the next process. In addition, since the coil application voltage saturation determination unit 99 detects the overflow of the electromagnetic coil 84, it is not necessary to decrease the gain of the servo control unit 91, and the response can be prevented from decreasing.

  Therefore, by detecting that the coil overflow has occurred, it is possible to prevent the out-of-system product from flowing into the next process without lowering the responsiveness.

  Further, in the weighing device 1 according to the present embodiment, the coil application voltage detection unit 98 detects the voltage applied to the electromagnetic coil 84 based on the voltage of the current detection resistor 93 connected in series to the electromagnetic coil 84. It is characterized by doing.

  With this configuration, it is possible to prevent the out-of-system product from flowing into the next process without lowering the responsiveness by detecting that the coil overflow has occurred.

  Moreover, in the weighing device 1 according to the present embodiment, the coil application voltage detection unit 98 detects the voltage applied to the electromagnetic coil 84 by detecting the output voltage of the coil application unit 92. .

  With this configuration, it is possible to prevent the out-of-system product from flowing into the next process without lowering the responsiveness by detecting that the coil overflow has occurred.

  Further, in the weighing apparatus 1 according to the present embodiment, the conveyance unit 3 that loads and unloads the object W to and from the weighing means 21 under predetermined conveyance conditions, and the object W that is unloaded from the conveyance unit 3 are acceptable. And a sorting unit 5 that discharges from the transport unit 3 when the determination result by the determination unit 76 is defective. When the control unit 74 determines that the weighing signal from the weighing unit 21 is abnormal, The sorting unit 5 is controlled to discharge the object W.

  With this configuration, when the coil overflow occurs, it is determined that the weighing signal is abnormal and the object to be weighed W is discharged, so that the out-of-system product can be prevented from flowing out to the next process.

  As described above, the measuring device according to the present invention has an effect that it is possible to prevent the out-of-system product from flowing into the next process without lowering the responsiveness by detecting that the coil overflow has occurred. It is useful as a weighing device that measures the quality of objects to be weighed such as meat, fish, processed foods, and pharmaceuticals.

1 Weighing device 3 Conveying unit (conveying means)
5 sorting section (sorting means)
DESCRIPTION OF SYMBOLS 7 General control part 10 Display means 11 Setting means 14 Belt conveyor 21 Weighing means 31 Run-up conveyor 32 Weighing conveyor 71 Signal processing means 72 Weighing means 73 Memory | storage means 74 Control means 76 Pass / fail judgment means 77 Mode switching means 81 Supporting point 82 Sa 83 Position Sensor 84 Electromagnetic coil 85 Suspension plate 86 Parallel spring 87 Common base 88 Magnet 91 Servo control unit 92 Coil application unit 93 Current detection resistor 94, 100 Amplifier 95 Analog filter 96 A / D converter 97 Filter 98 Coil application voltage detection unit ( Coil applied voltage detection means)
99 Coil applied voltage saturation determination unit (coil applied voltage saturation determination means)
W Object to be weighed

Claims (4)

An electromagnetic coil (84) and a coil application unit (92) for applying electric power to the electromagnetic coil, and balances the load caused by the object to be weighed (W) and the force generated by the current flowing through the electromagnetic coil. An electromagnetic balance type weighing means (21) for measuring a current value flowing through the electromagnetic coil and outputting it as a weighing signal;
Weighing means (72) for receiving the weighing signal and calculating a measured value of the object to be weighed;
Pass / fail judgment means (76) for comparing the measured value calculated by the weighing means and the pass / fail judgment criteria to judge pass / fail of the object to be weighed;
Coil application voltage detection means (98) for detecting a voltage applied to the electromagnetic coil;
Coil application voltage saturation determination means (99) for determining whether or not the voltage detected by the coil application voltage detection means is saturated;
And a control unit (74) for determining that the weighing signal from the weighing unit is abnormal when the coil application voltage saturation determining unit determines that the voltage is saturated. .   The measuring device according to claim 1, wherein the coil application voltage detection unit detects a voltage applied to the electromagnetic coil based on a voltage of a current detection resistor connected in series to the electromagnetic coil. .   The measuring device according to claim 1, wherein the coil application voltage detection unit detects a voltage applied to the electromagnetic coil by detecting an output voltage of the coil application unit. A transport means (3) for carrying an object to be weighed into and out of the weighing means under a predetermined transport condition;
Sorting means (5) for discharging the object to be weighed unloaded from the conveying means from the conveying means when the determination result by the quality determining means is defective, and
4. The control unit according to claim 1, wherein the control unit controls the selection unit to discharge the object to be weighed when it is determined that the weighing signal from the weighing unit is abnormal. The metering device described.

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