JP7109396B2 - Weighing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a weighing device that weighs an object to be weighed, such as meat, fish, processed food, and pharmaceuticals, while transporting it, and determines the quality of the object to be weighed.

Conventionally, there has been used a weighing device that is incorporated in a production line for foodstuffs, etc., in which the products to be produced are sequentially brought in from the front stage, weighed while transporting the carried-in items, and then carried out or removed from the production line by sorting means at the rear stage. ing.

For example, the following techniques are known in order to maintain good weighing performance of such a weighing device and maintain weighing accuracy.

For example, Patent Document 1 discloses a weighing apparatus equipped with diagnostic means for diagnosing the state of conveying means for conveying an object to be weighed based on a signal-processed signal obtained by performing predetermined signal processing on a weighing signal. is disclosed.

Further, for example, Patent Document 2 discloses a memory means for storing the result of frequency analysis of the output signal of the load detecting section when the weighing device is normal, in association with the frequency and the drive member, and Disclosed is a weighing apparatus provided with processing means for performing predetermined processing using the analysis results and the normal results stored in the storage means.

JP 2011-122929 A Japanese Patent No. 4101381

According to the technique disclosed in Patent Document 1, it is possible to diagnose how much abnormal vibrations generated in conveying means such as rollers and bearings of a weighing conveyor affect the weighing performance, and to detect an abnormality in the conveying means. However, there is a problem that it is not possible to know which part of the conveying means has deteriorated.

Further, according to the technique disclosed in Patent Document 2, by comparing and examining the difference in amplitude between the vibration state obtained as a result of frequency analysis and the vibration state in the normal state, it is possible to determine which of the plurality of driving members included in the transport unit It is possible to identify which of these is the source of the abnormality, but if the accuracy required for weighing the object to be weighed cannot be satisfied due to the deterioration of the part of the transport means, which part will deteriorate There was a problem that it was not possible to identify the cause.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve the above-described conventional problems. To provide a weighing device capable of determining whether or not there is a rotating part that is in a state of being deteriorated to the point of disappearing, and specifying the rotating part that is the cause of the deterioration.

A weighing apparatus according to the present invention includes weighing means for supporting a conveying means composed of a plurality of connected rotating parts, for outputting a weighing signal based on the load of the conveying means and an object to be weighed; and weighing means for processing a signal to calculate the weight value of the object to be weighed, wherein when the conveying means is operated while the object to be weighed is not on the conveying means, the vibration measuring means for measuring vibration components corresponding to each of the plurality of rotating parts based on the weighing signal output by the weighing means; and corresponding to each of the plurality of rotating parts measured in advance by the vibration measuring means. initial variation amount storage means for calculating an amount of variation representing a weighing error related to the vibration component and storing it as an initial variation amount; Based on the amount of variation representing the weighing error related to the vibration component, the initial amount of variation with respect to other rotating portions among the plurality of rotating portions, and a preset reference amount of variation, the measurement of the one rotating portion is performed. and deterioration determining means for determining deterioration and outputting a determination result.

With this configuration, it is possible to determine whether the plurality of rotating parts that constitute the conveying means are in a deteriorated state in which the accuracy required for weighing the object to be weighed cannot be satisfied. The determination can be made based on the stored initial variation value and reference variation value. Therefore, by replacing or repairing only the rotating parts that have deteriorated due to wear or looseness, it is possible to maintain good weighing performance and maintain weighing accuracy. By detecting deterioration of rotating parts at an early stage, it is possible to avoid production stoppages due to failures and reduce downtime of the production line.

Further, in the weighing apparatus according to the present invention, the deterioration determination means determines deterioration of each of the plurality of rotating parts, and operates the transport means in a state in which the object to be weighed is not on the transport means. The amount of variation representing the weighing error associated with the weighing signal output by the weighing means is calculated, the amount of variation of one rotating part to be determined is added to the amount of variation, and the initial Deterioration of each rotating portion is determined by subtracting the amount of variation.

With this configuration, the deterioration determining means subtracts the "initial variation amount C related to the vibration component of a certain rotating part" from the "previously measured variation amount B" to obtain the "current variation related to the vibration component of a certain rotating part Based on the value (B−C+A) obtained by adding the amount A”, it becomes possible to determine the deterioration of the rotating part to be determined.

Further, in the weighing apparatus according to the present invention, the reference amount of variation is set based on an allowable error range for the weighed value of the object to be weighed by the weighing means.

With this configuration, it becomes possible to determine the deterioration of each rotating part constituting the conveying means in accordance with the tolerance defined by the accuracy grade of weighing required for the weighing means or the test interval.

Further, in the weighing device according to the present invention, a variation amount representing a weighing error related to a vibration component corresponding to one of the plurality of rotating portions is set as the initial variation amount of the rotating portion. It is characterized by storing in a storage means.

With this configuration, the initial variation amount stored in the initial variation amount storage means can be updated to the newly measured variation amount related to the vibration component and stored for the rotating portion that has been replaced or repaired. become able to.

Further, the weighing apparatus according to the present invention is characterized in that the initial variation amount associated with each of a plurality of different transport speeds realized by the transport means is stored in the initial variation amount storage means.

With this configuration, it is possible to easily determine the deterioration of each rotating portion of the conveying means corresponding to the types of the plurality of objects to be weighed associated with each of the plurality of conveying speeds.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. It is possible to provide a weighing device capable of

1 is a perspective view showing the appearance of a weighing device according to an embodiment of the present invention; FIG. It is a block diagram showing an internal configuration of a weighing device according to an embodiment of the present invention. It is a side view which shows the conveyance part of the weighing|weighing apparatus which concerns on embodiment of this invention. FIG. 4 is a diagram for explaining an overview of deterioration determination processing by a deterioration determination unit of the weighing device according to the embodiment of the present invention; It is a flowchart which shows an example of the operation|movement of the initial state acquisition mode in the weighing|measuring device which concerns on embodiment of this invention. It is a flow chart which shows an example of operation of diagnosis mode in a weighing device concerning an embodiment of the invention. FIG. 4 is a diagram for explaining an example of visualization of calculation and deterioration determination by a deterioration determination unit in the weighing device according to the embodiment of the present invention, and (B) is a diagram visually showing the numerical value of the "current variation amount A related to the vibration component of a certain rotating part". (C) is a diagram visually showing numerical values of "BC+A" when the objects to be determined are the conveying belt, the driving motor, and the rollers. FIG. 8 is a diagram for explaining another example of visualizing the calculation and deterioration determination of the deterioration determination unit in the weighing device according to the embodiment of the present invention; FIG. 10B is a diagram visually showing the numerical value of the initial variation amount C related to the vibration component of the rotating part, and (B) visually shows the numerical value of the "current variation amount A related to the vibration component of a certain rotating part" FIG. 11C is a diagram visually showing numerical values of “BC+A” when the objects to be determined are the conveying belt, the driving motor, and the rollers.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a weighing device according to the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of a weighing device according to the invention.

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

The weighing device 1 is installed on the downstream side of a belt conveyor 14 that constitutes a part of the production line, and weighs meat, fish, processed foods, medicines, etc. that are successively 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 the measurement result.

Furthermore, the weighing device 1 compares the obtained measured value with preset upper and lower reference values for weight, and determines whether the obtained measured value is within the range of the reference values. , the products within the range are determined to be non-defective products, and the products outside the range are determined to be defective products. Furthermore, the weight rank determination may be made according to a plurality of reference values.

Further, determination results such as measurement results, pass/fail determination results, and weight rank determination results are displayed on the display unit 10, for example, and are output to the sorting unit 5 connected to the rear stage of the weighing device 1. .

The device main body 2 includes a weighing unit 21, and further includes an integrated control unit 7, a display unit 10, an operation unit 11, a transport control unit 13, and a mode switching unit 80 in the storage housing 2a. It is configured.

The transport section 3 transports the objects W to be weighed carried in the direction of the arrow A from the belt conveyor 14 under predetermined transport conditions. The object W to be weighed is accelerated or decelerated to an optimum speed for measurement by the run-up conveyor 31 and is further conveyed by the weighing conveyor 32. 21. The weighing conveyor 32 conveys the objects W to be weighed under predetermined conveying conditions, and the conveying speed is selected according to the type of the objects W to be weighed, for example. After weighing, the objects W to be weighed are further transported to the rear-stage sorting section 5 and sorted.

The transport section 3 is composed of an approach conveyor 31 and a weighing conveyor 32 . The run-up conveyor 31 carries out run-up of the objects W conveyed from the preceding belt conveyor 14 before the objects W to be weighed move to the weighing conveyor 32. Two rollers 31a and 31c and and an endless conveyor belt 31b wound around rollers 31a and 31c.

The weighing conveyor 32 is supported above the weighing unit 21 that weighs the objects W to be weighed. and a drive motor 12 that drives at least one of the rollers 32a and 32c (for example, the roller 32c). The motor 12 and the roller 32c each have a pulley, and the drive motor 12 rotates the roller 32c by means of a drive belt, so that the objects W to be weighed on the conveyor belt 32b are conveyed in the arrow B direction at a predetermined speed. It has become so. In addition, the load of the weighing conveyor 32 is measured by the weighing unit 21 arranged below it.

The carry-in sensor 4 is composed of a transmission type photoelectric sensor comprising a pair of light projecting portion 4a and light receiving portion 4b, and is arranged between the approach conveyor 31 and the weighing conveyor 32. As shown in FIG. Specifically, the light projecting unit 4a is arranged on the side of the conveying belt 32b on the side of the device main unit 2, and the light receiving unit 4b is arranged on the other side of the conveying belt 32b so as to face the light projecting unit 4a, _A position connecting the light projecting portion 4a and the light receiving portion 4b is the carry-in start detection position PO. When the object W to be weighed passes between the light projecting portion 4a and the light receiving portion 4b, the light receiving portion 4b is blocked by the object W to be weighed, so that the start of carry-in of the object W to be weighed is detected. ing. A signal indicating the start of carry-in detected is output to the integrated control section 7 in the main body section 2 of the apparatus.

The transport control unit 13 controls driving of the drive motor 12 to control the rotation speed (rpm) of the drive motor 12 . The transport control unit 13 can control the transport speed of the objects W to be weighed on the transport belt 32 b of the weighing conveyor 32 by controlling the rotation of the drive motor 12 . The conveying speed of the conveying belt 32b differs depending on the type of the object W to be weighed. can be identified.

Further, when the transport control unit 13 receives from the mode switching unit 80 a signal instructing to operate in an initial state capture mode, which will be described later, the transport control unit 13 cooperates with the general control unit 7 to transport at a predetermined timing. The driving of the drive motor 12 is controlled so as to change the conveying speed of the belt 32b. In the initial state capture mode, the conveyance control unit 13 divides the range from the lowest speed to the highest speed that the conveying speed of the conveying belt 32b can take, for example, into a plurality of speed ranges, and divides the range into a plurality of stages at predetermined timings. , so that the conveying speed of the conveying belt 32b becomes a conveying speed representing each stage (for example, N different conveying velocities V ₁ to V _N , which are the center values of the speed range in each stage, where N is an integer of 2 or more). You may make it switch. The initial variation amount corresponding to all the transport speeds is stored in the initial variation amount storage unit 74 by covering all the transport speeds by the speed range of each step related to the transport speeds V ₁ to V _N. become.

On the other hand, when the transport control unit 13 receives from the mode switching unit 80 a signal instructing to operate in a diagnostic mode, which will be described later, the transport control unit 13 selects a specific transport speed (item to be weighed) at which the transport speed of the transport belt 32b is designated. The driving of the drive motor 12 is controlled so that the conveying speed of the conveying belt 32b corresponding to the type of W is obtained.

The mode switching unit 80 switches the operation mode of the weighing device 1 among a normal operation mode, an initial state acquisition mode, and a diagnosis mode.

The normal operation mode is a normal operation mode in which the weighing device 1 calculates the weight value of the object W to be weighed and determines whether the object W is good or bad.

The initial state acquisition mode is a normal state in which the weighing device 1 can operate with the accuracy required for weighing the objects W to be weighed in the normal operation mode (hereinafter also referred to as the required accuracy). In an initial state in which each of the rotating parts constituting the conveying unit 3 is not degraded, the amount of variation (measurement error amount) related to the vibration component of each rotating part of the conveying unit 3 is set as the initial variation amount, and the initial variation amount storage unit 74 This is the operation mode to be stored in the The initial state capture mode is performed infrequently, for example, after any rotating part of the conveying unit 3 is replaced or repaired. At this time, it is possible to reset only the initial amount of variation for the rotating portion for which the part has been replaced or repaired, or to reset all of the initial amount of variation in the initial variation amount storage unit 74 .

The diagnostic mode is an operation mode in which the weighing device 1 determines the deterioration of each rotating part that constitutes the conveying unit 3 .

The mode switching unit 80 switches the operation mode of the weighing device 1 to any one of a normal operation mode, an initial state acquisition mode, and a diagnostic mode according to an input operation on the operation unit 11. FIG. When an instruction to start an operation mode is given by an input operation on the operation unit 11, the mode switching unit 80 outputs a signal instructing the general control unit 7 and the transport control unit 13 to operate in that operation mode. .

Note that, when an instruction to start the normal operation mode is given by an input operation on the operation unit 11, the mode switching unit 80 instructs the integrated control unit 7 and the transport control unit 13 to once operate in the diagnosis mode, and The mode may be switched to the normal operation mode when it is determined that none of the rotating parts of the transport unit 3 has deteriorated in the mode.

The weighing unit 21 is composed of a weighing mechanism such as an electromagnetic balance mechanism. is designed to measure the total weight of The weighing unit 21 may be any scale mechanism capable of measuring weight, and may be configured with a scale mechanism such as a differential transformer mechanism or a strain gauge mechanism, for example.

The weighing unit 21 performs weighing when a preset reference time Tk elapses after the carry-in sensor 4 detects that the object W to be weighed has been carried onto the weighing conveyor 32, for example. . When the reference time Tk elapses after it is detected that the object W to be weighed has been carried into the weighing conveyor 32, the object W to be weighed moves from the carry _- in start detection position _PO by _L1 and reaches the mass measurement position PS. and the weighing takes place at this position. The weighing unit 21 is set with conditions such as its measuring range, measuring capability and inspection accuracy according to the type of the object W to be weighed, and weighs the object W to be weighed based on these conditions.

The integrated control unit 7 includes a signal processing unit 71 , a weighing unit 72 , a quality determination unit 73 , an initial variation amount storage unit 74 , a deterioration determination unit 75 and a threshold storage unit 76 .

The signal processing section 71 performs signal processing on the weighing signal supplied from the weighing section 21, and includes a filter processing section 71a and a vibration measuring section 71b. An amplifier that amplifies the weighing signal supplied from the weighing unit 21 and an A/D converter that digitally converts the amplified signal may be provided in the preceding stage of the signal processing unit 71 .

The filter processing unit 71a uses a filter selected from a plurality of low-pass filters having different types and characteristics for the weighing signal from the weighing unit 21, and converts only the low-frequency component of the weighing signal into a signal-processed weighing signal. It is designed to let through and operates in normal operating mode. The filter used in the filter processing section 71a is selected by the filter setting section 77 according to the type of the object W to be weighed.

There may be one low-pass filter used for filtering by the filter processing unit 71a, or a combination of a plurality of low-pass filters. This low-pass filter includes an FIR (Finite Impulse Response) filter and an IIR (Infinite Impulse Response) filter.

An FIR filter is a finite impulse response filter that outputs an output only for a certain time (finite time) when an impulse response waveform is input. It is a response filter.

Here, the FIR filter constitutes a low-pass filter that passes predetermined low-frequency components with respect to the weighing signal converted into a digital signal by the A/D converter, and uses a simple averaging process or a known window function. weighted averaging process.

The IIR filter is an analog filter that directly receives the weighing signal (analog weighing signal) from the weighing unit 21 using hardware whose characteristics can be changed, such as a switched capacitor filter, and outputs the processed signal to the A/D converter. or a digital filter that receives a digital weighing signal from an A/D converter.

The weighing unit 72 calculates (converts into grams) the weighing value of the object W to be weighed based on the signal-processed weighing signal output from the filter processing unit 71a. In addition, the weighing unit 72 is set with conditions such as its measuring range, measuring capability and inspection accuracy according to the type of the object W to be weighed, and weighs the object W to be weighed based on these conditions. there is Furthermore, in the weighing unit 72, when the carry-in sensor 4 detects that the object W to be weighed has been carried onto the weighing conveyor 32 and the predetermined reference time Tk has passed (that is, the mass of the object W to be weighed is A weighing value is calculated for the object W for which a weighing signal is output from the weighing unit 21 (at the position _PS ). The measurement result of each weight calculated by the weighing unit 72 is displayed on the display unit 10, for example, and is output to the quality determination unit 73 to determine the quality of the object W to be weighed.

The reference time Tk is set based on the conveying speed corresponding to the type of the object W to be weighed. Specifically, the speed (m/min) of the weighing conveyor 32, the length (mm) of the weighing conveyor 32 in the direction of arrow B, the length (mm) in the direction of arrow B, which is the conveying direction of the object W to be weighed, It is set based on the size of the object W to be weighed, the processing capacity of the line, and other conditions. Further, as shown in FIG. 3, after the reference time Tk has elapsed, the object W to be weighed moves from the carry _- in start detection position _PO by _L1 and reaches the mass measurement position PS, where it is weighed.

The quality judgment unit 73 judges the quality of the object W to be weighed, and is composed of a judgment circuit and the like. It is designed to judge.

Specifically, upon receiving the weight signal of the object W to be weighed output from the weighing unit 72, the quality determination unit 73 compares the upper limit value Ga and the lower limit value Gb of the weight with the weight of the object W to be weighed. , the upper limit Ga and the lower limit Gb.

The judgment result determined by the good/bad judging section 73 is output to the display section 10 and displayed as a non-defective product or a defective product. Further, the determination result is output to the sorting unit 5 connected to the rear stage of the weighing device 1, and the objects W to be weighed are sorted as non-defective or defective. Furthermore, the determination result may be output to a predetermined storage medium or the like, and the determination result for each object W to be weighed may be stored.

On the other hand, the vibration measuring section 71b is adapted to measure vibration components corresponding to each of the plurality of rotating parts constituting the conveying section 3 based on the weighing signal output from the weighing section 21, and measures the initial state. Runs in embedded or diagnostic mode. The rotating parts of the conveying unit 3 whose vibration component is to be measured include, for example, the motor 12 as a rotational driving source, rollers 32a and 32c as rotational driving members, a conveying belt 32b, and a driving belt (not shown). . All of the rotating parts perform rotational motion in the normal operation mode, and become sources of vibration caused by the rotational motion.

The vibration component of each rotating portion constituting the conveying section 3 is obtained by passing a weighing signal through a bandpass filter corresponding to the rotation frequency determined for each rotating portion. Specifically, by passing the weighing signal through a band-pass filter whose center frequency is the rotation frequency associated with the rotation of each rotating part that constitutes the conveying unit 3, the vibration due to the rotation of each rotating part was extracted. A signal is obtained resulting in a vibration component of each rotating part. Further, the weighing signal is subjected to FFT (Fast Fourier Transform) analysis based on the rotation frequency associated with the rotation of each rotating portion that constitutes the conveying unit 3, and the power of the rotation frequency associated with the rotation of each rotating portion obtained from the FFT analysis result. , it is also possible to calculate the vibration component of each rotating part.

Further, the vibration measurement unit 71b calculates the variation amount (weighing error amount: equivalent to the degree of dispersion of standard deviation, dispersion, etc. in statistics) related to the vibration component of each rotating part obtained as described above. It's becoming As an example of the amount of variation associated with the vibration component of each rotating portion constituting the transport section 3, a value three times the standard deviation (3σ value) can be used as the measurement error amount associated with the vibration component of each rotating portion.

In the initial state acquisition mode, the conveying speed of the conveying belt 32b is changed, and the vibration measuring unit 71b measures each rotating portion constituting the conveying unit 3 at each conveying speed (for example, each of N kinds of conveying speeds V ₁ to V _N ). , the amount of variation related to the vibration component of is calculated. In the initial state acquisition mode, the thus-calculated variation amount related to the vibration component of each rotating part is output to the initial variation amount storage unit 74 in a state associated with the conveying speed of the conveying belt 32b.

On the other hand, in the diagnosis mode, the conveying speed of the conveying belt 32b is fixed at a specific conveying speed, and the vibration measurement unit 71b calculates the amount of variation in the vibration component of each rotating part of the conveying unit 3 at the specific conveying speed. do. In the diagnostic mode, the amount of variation associated with the vibration component of each rotating part calculated in this way is output to the deterioration determining section 75 .

The initial variation amount storage unit 74 is a non-volatile storage medium or the like that retains the stored content even when the power is turned off. The amount of variation representing the measurement error associated with the vibration component of the part is stored as the amount of initial variation. In the initial state acquisition mode, the initial variation amount is stored while changing the conveying speed of the conveying belt 32b. For example, the conveying speed of the conveying belt 32b is divided into a plurality of stages for each predetermined speed range, and the vibration component of each rotating part associated with each stage of conveying speed (for example, each of N kinds of conveying speeds V ₁ to V _N ) Such a variation amount is stored in the initial variation amount storage unit 74 . The conveying speed of the conveying belt 32b differs depending on the type of the object W to be weighed. An appropriate initial variation amount can be read when the diagnosis mode is executed, regardless of the type of the object W to be weighed.

As described above, the initial state capture mode is performed infrequently, for example, after any rotating portion of the conveying section 3 is replaced or repaired. The initial variation amount stored in the initial variation amount storage unit 74 is used as a reference value indicating a normal state in which each rotating part constituting the conveying unit 3 is not deteriorated.

The deterioration determination unit 75 performs deterioration determination processing for determining deterioration of each rotating part constituting the transport unit 3 and outputs the determination result, and operates in a diagnosis mode. When it is determined that none of the rotating parts of the conveying unit 3 have deteriorated, the determination result output by the deterioration determining unit 75 includes information indicating that none of the rotating parts have deteriorated. On the other hand, when it is determined that any of the rotating parts of the conveying unit 3 has deteriorated, the determination result output by the deterioration determining unit 75 includes information specifying the rotating part determined to be deteriorated. be The determination result of the deterioration determination unit 75 is displayed on the display unit 10, for example.

During the operation in the diagnostic mode, the deterioration determination unit 75 receives from the vibration measurement unit 71b the current amount of variation in the vibration component of each rotating part of the transport unit 3 at a specific transport speed of the transport belt 32b. ing. Further, the deterioration determination unit 75 reads out from the initial variation amount storage unit 74 the initial variation amount related to the vibration component of each rotating part, which is stored in association with the specific transport speed of the transport belt 32b. .

The deterioration determination unit 75 determines both the amount of variation related to the vibration component of each rotating part supplied from the vibration measuring unit 71b and the amount of variation related to the vibration component of each rotating part read from the initial variation amount storage unit 74. On the other hand, an attenuation coefficient multiplication process is performed in which an attenuation coefficient corresponding to the filter characteristics of the filter selected by the filter setting unit 77 is multiplied. By doing so, the higher the frequency of the vibration component of each rotating part of the conveying unit 3, the smaller the amount of variation in accordance with the characteristics of the low-pass filter used for the weighing signal in the filter processing unit 71a. .

The filter setting unit 77 selects a filter used in the filter processing unit 71a, and selects a filter according to the type of the object W to be weighed from a plurality of low-pass filters having different types and characteristics. . The filter setting unit 77 selects and sets the filter used in the filter processing unit 71a, and also sets so that the attenuation coefficient corresponding to the filter characteristics of the same filter is used in the attenuation coefficient multiplication processing in the deterioration determination unit 75. do.

Further, the deterioration determination unit 75 reads a threshold associated with the type of the object W to be weighed from among the plurality of thresholds stored in the threshold storage unit 76 .

The threshold storage unit 76 is a non-volatile storage medium or the like that retains stored content even when the power is turned off. It stores the threshold used as The threshold used as the reference variation amount in the deterioration determination unit 75 may be, for example, the same value as the required accuracy or a value obtained from the required accuracy (for example, a value obtained by multiplying the required accuracy by a positive value smaller than 1). Alternatively, it may be selected from among a plurality of threshold values according to tolerances defined by the accuracy grade of weighing in the weighing unit 21 or the test scale interval.

As described above, the deterioration determination unit 75 reads out the value obtained by multiplying the variation amount related to the vibration component of each rotating part supplied from the vibration measurement unit 71b by the attenuation coefficient and the initial variation amount storage unit 74. It is possible to obtain a value obtained by multiplying the initial variation amount of the vibration component of each rotating part by a damping coefficient multiplication process. Degradation determination processing can be performed using the threshold value T) as a reference amount of variation.

Here, an outline of deterioration determination processing by the deterioration determination unit 75 will be described with reference to FIG. 4 . In FIG. 4, the vertical axis is the weight variation 3σ value (three times the standard deviation σ) (unit: g), and the horizontal axis is the mass (unit: g) of the object to be weighed W to be inspected. A numerical axis is set. Also, FIG. 4 shows numerical values and graphs for a weighing machine with an accuracy grade of 3 and a verification scale factor of e=0.1 g.

The required accuracy graph in FIG. 4 shows the relationship between the mass of the product to be inspected and the weight variation 3σ value. For example, it indicates that the required accuracy represented by the weight variation 3σ value is determined for the mass of a certain inspection item.

The required accuracy graph in FIG. 4 shows the relationship between the mass of the inspection item and the 3σ value of the amount of variation in weight. It shows that the value of the required accuracy is determined. In the example of FIG. 4, the required accuracy (unit: g) is determined for the mass m (unit: g) of the product to be inspected, and this required accuracy is used as the threshold value T for determining deterioration.

In addition, in FIG. 4, there are shown a “preliminarily measured variation amount B” (unit: g) and an “initial variation amount C” (unit: g ) are represented by columnar elements.

The “variation amount B measured in advance” is the initial weighing error amount of the weighing device 1 as a whole. The "pre-measured variation amount B" is a reference variation amount that is a pre-measured repeatability, and is an allowable error range for the weighed value of the object W to be weighed, such as an estimated accuracy or an allowable error defined by a test amount. may be set based on Further, the deterioration determination unit 75 may calculate the “preliminarily measured variation amount B” based on the initial variation amount read from the initial variation amount storage unit 74 . Specifically, the deterioration determination unit 75 determines the initial variation amount related to the vibration component of each rotating part of the transport unit 3 stored in association with the transport speed corresponding to the mass m of the inspection item. The total sum of the values obtained by reading out from the storage unit 74 and performing the damping coefficient multiplication process on the variation amounts related to the vibration components of all the rotating parts may be used as the "previously measured variation amount B".

The “initial variation amount C related to the vibration component of a certain rotating part” is the initial weighing error amount related to the vibration component of a certain rotating part (rotating part to be determined) of the transport unit 3 . The deterioration determination unit 75 can calculate the “initial variation amount C related to the vibration component of a certain rotating part” based on the initial variation amount read from the initial variation amount storage unit 74 . Specifically, the deterioration determination unit 75 reads out from the initial variation amount storage unit 74 the amount of variation related to the vibration component of each rotating part, which is stored in association with the transport speed corresponding to the mass m of the product to be inspected. A value obtained by multiplying the variation amount related to the vibration component of the rotating part by the attenuation coefficient can be used as the "initial variation amount C related to the vibration component of a certain rotating part".

FIG. 4 also shows the "current variation amount A regarding the vibration component of a certain rotating part" (unit: g). The “current variation amount A related to the vibration component of a certain rotating part” is the current weighing accuracy (error amount) related to the vibration component of a certain rotating part of the transport unit 3 (rotating part to be determined). The deterioration determination unit 75 can calculate the "current variation amount A related to the vibration component of a certain rotating part" based on the value supplied from the vibration measurement unit 71b. Specifically, the deterioration determination unit 75 multiplies the amount of variation related to the vibration component of each rotating part supplied from the vibration measuring unit 71b by the attenuation coefficient, and determines the value as "the value related to the vibration component of a certain rotating part". It can be set as the current variation amount A”.

The deterioration determination unit 75 subtracts the "initial amount of variation C related to the vibration component of a certain rotating part" from the "amount of variation B measured in advance" to obtain the "current amount of variation A related to the vibration component of a certain rotating part". The added value (that is, BC+A) is calculated, the calculation result is compared with a threshold value, and it is determined whether or not the rotating part is degraded based on whether the calculation result is within a predetermined range. The predetermined range for determining deterioration may be, for example, a range set by one threshold, or set by a plurality of thresholds according to the tolerance defined by the accuracy grade of weighing in the weighing unit 21 or the test scale. may be within the range. The calculation result (B−C+A) represents the case where the weighing accuracy in the initial state of the entire weighing device 1 is replaced with the current weighing accuracy only for the rotating part to be judged. That is, the calculation result (B−C+A) represents a virtual configuration in which only the rotation part to be judged is replaced with the current one in the initial state, and the variation amount related to the vibration component other than the rotation part to be judged. does not take into consideration the current amount of variation related to the vibration component of only the rotating part to be determined. If this virtual configuration does not satisfy the required accuracy required for the weighing device 1 as a whole, it is determined that the rotating part to be determined has deteriorated to the extent that parts replacement or repair is required.

Further, as shown in FIG. 1, the display section 10 is provided at the upper end portion of the apparatus main body section 2 on the conveying section 3 side, and is composed of a display device such as a liquid crystal display.

When the operation mode of the weighing device 1 is the weighing mode, the display unit 10 displays the operating state of the weighing device 1, the weighed value of the object W to be weighed, and the quality judgment result. , various settings are displayed. Note that the display unit 10 may be configured as a touch panel through which displayed numbers, characters, and the like are input by touch operation, and used as the operation unit 11 .

The sorting unit 5 connected to the rear stage of the weighing device 1 sorts the objects W to be weighed according to the measurement results output from the weighing device 1, the quality judgment results, the weight rank judgment results, and the like.

The sorting unit 5 connected to the rear stage of the weighing device 1 is composed of a sorting mechanism unit 5a and a sorting conveyor 5b that conveys the objects W to be weighed by a conveying belt 5d. It is composed of an extrusion-type sorting mechanism. The sorting mechanism section 5a may be any one capable of sorting non-defective products from defective products, and may be constituted by a sorting mechanism such as a flipper mechanism, a dropout mechanism, or an air jet mechanism.

The sorting mechanism unit 5a moves the conveying belt for the objects W determined to be defective while the objects W to be weighed conveyed from the upstream weighing conveyor 32 are being conveyed in the direction of the arrow B by the sorting conveyor 5b. Defective objects W to be weighed are ejected from the conveyor belt 5d and sorted by distinguishing them from non-defective objects W to be weighed. there is

The conveyor belt 5d is composed of a roller 5c, a roller (not shown) arranged opposite to the roller 5c, and an endless conveyor belt wound around these rollers. The object W to be weighed is conveyed downstream at a predetermined speed.

The operation of the weighing device 1 according to the embodiment of the present invention will be described below. The weighing device 1 according to the embodiment of the present invention is designed to perform operations in a normal operation mode, an initial state acquisition mode, and a diagnosis mode.

The operation of the weighing device 1 according to the embodiment of the present invention in the normal operation mode will be explained. In the normal operation mode, the weighing unit 21 weighs the object W being transported by the transport unit 3 and outputs a weighing signal including the weighing result of the object W to be weighed. The filter processing unit 71a filters the weighing signal output from the weighing unit 21, and the weighing unit 72 determines the weight of the object W based on the signal-processed weighing signal output from the filter processing unit 71a. Calculate the weight value. Then, the quality determination unit 73 determines the quality of the object W to be weighed based on the measurement results of the individual weights calculated by the weighing unit 72 .

Next, operation of the initial state capture mode in the weighing device 1 according to the embodiment of the present invention will be described. FIG. 5 is a flow chart showing an example of the operation of the initial state capture mode in the weighing device 1 according to the embodiment of the present invention.

In the normal operation mode, the weighing unit 21 weighs the objects W to be weighed that are being transported by the transport unit 3 , whereas in the initial state capture mode, the objects W to be weighed are not on the transport unit 3 . A weighing signal output from the weighing unit 21 when the conveying unit 3 is operated is used.

Upon receiving a signal instructing to operate in the initial state capture mode, the transport control section 13 cooperates with the general control section 7 to start predetermined loop processing. Here, as an example, the transport control unit 13 divides the possible range of the transport speed of the transport belt 32b into a plurality of stages (for example, the center value of the speed range in each stage is N different transport speeds V ₁ to V _N ). The operation of storing the initial variation amount that can correspond to all conveying speeds (that is, all product types) by dividing will be described.

The transport control unit 13 sets the maximum value of the loop processing (step S101) and sets the variable i of the loop processing to i=1 (step S102). Then, the transport control unit 13 controls driving of the drive motor 12 to operate the transport belt 32b at the transport speed Vi ₌₁ (step S103). In this state, a weighing signal is output from the weighing unit 21 to the vibration measuring unit 71 b of the signal processing unit 71 .

The vibration measurement unit 71b, for example, uses a band-pass filter whose center frequency is the rotation frequency associated with the rotation of each rotating part constituting the conveying unit 3 to pass the weighing signal. Vibration components of the parts are measured, and further, from the measurement results of the vibration components, the amount of variation related to the vibration components of each rotating part is calculated (step S104).

The vibration measurement unit 71b associates the amount of variation related to the vibration component of each rotating part constituting the transport unit 3 with the currently set transport speed (here, the transport speed V _{i =1} ), and stores the initial variation amount storage unit 74. (step S105). Then, it is determined whether or not the variable i has reached the maximum value N of the loop processing (step S106). When i is smaller than the maximum value N of the loop processing, the variable i is incremented (step S107), and the processing after step S103 is repeated. When the variable i reaches the maximum value N of the loop processing (YES in step S106), the operation related to the initial state acquisition mode ends.

As a result, similar processing is performed for variables i=1 to N, and the amount of variation related to the vibration component of each rotating portion associated with each of the N different conveying speeds Vi _{=1 to N} is the initial variation. The amount is stored in the initial variation amount storage unit 74 .

Next, operation of the diagnostic mode in the weighing device 1 according to the embodiment of the present invention will be described. FIG. 6 is a flowchart showing an example of diagnostic mode operation in the weighing device 1 according to the embodiment of the present invention.

In the diagnosis mode, similarly to the initial state acquisition mode, the weighing signal output from the weighing unit 21 is used in a state in which the conveying unit 3 is operated without the object W to be weighed on the conveying unit 3 .

Upon receiving the signal instructing to operate in the diagnosis mode, the transport control unit 13 controls the driving of the drive motor 12 to move the transport belt 32b to the currently set specific transport speed V _D (for example, N different speeds). any one of the transport speeds V ₁ to V _N ) (step S201). In this state, a weighing signal is output from the weighing unit 21 to the vibration measuring unit 71 b of the signal processing unit 71 .

The vibration measurement unit 71b, for example, uses a band-pass filter whose center frequency is the rotation frequency associated with the rotation of each rotating part constituting the conveying unit 3 to pass the weighing signal. Vibration components of the parts are measured, and from the results of the measurement of the vibration components, the current amount of variation in the vibration components of the rotating parts of the conveying unit 3 is calculated (step S202). This calculation result is output to the deterioration determination unit 75 .

The deterioration determining unit 75 receives from the vibration measuring unit 71b the current variation amount related to the vibration component of each rotating part constituting the conveying unit 3, and the current conveying speed of the conveying belt 32b (specific conveying speed V _D : However, D is any integer from 1 to N), and the initial amount of variation (initial amount of variation) related to the vibration component of each rotating part is read out from the initial amount of variation storage unit 74 (step S203). If the possible range of the transport speed of the transport belt 32b is divided into a plurality of predetermined speed ranges, the deterioration determining unit 75 determines the level of the current transport speed of the transport belt 32b. An initial amount of variation associated with the vibration component of each rotating portion associated with is read.

The deterioration determination unit 75 determines both the current variation amount related to the vibration component of each rotating part supplied from the vibration measuring unit 71b and the initial variation amount related to the vibration component of each rotating part read from the initial variation amount storage unit 74. is multiplied by an attenuation coefficient corresponding to the filter characteristic selected by the filter setting unit 77 (step S204). The filter at this time is a filter corresponding to the type of the objects W to be weighed corresponding to the specific conveying speed _VD of the conveying belt 32b, and is the same as the filter used in the filter processing section 71a.

The deterioration determination unit 75 reads from the threshold storage unit 76 the threshold associated with the type of the object W corresponding to the currently set specific transport speed _VD of the transport belt 32b (step S205).

The deterioration determination unit 75 calculates a value obtained by multiplying the current variation amount related to the vibration component of each rotating part supplied from the vibration measurement unit 71b by an attenuation coefficient, A value obtained by multiplying the initial variation amount of the vibration component of the part by the attenuation coefficient can be obtained. is used as the reference variation amount. More specifically, the deterioration determination unit 75 determines the "current variation amount A regarding the vibration component of a certain rotating part", the "previously measured variation amount B", and the "initial variation amount relating to the vibration component of a certain rotating part". C", and the result of the calculation is compared with a threshold value. If the result of the calculation exceeds the threshold value, it is determined that the rotating part to be determined is deteriorated (step S206).

The deterioration determination unit 75 causes the display unit 10 to display the determination result in the deterioration determination process (step S207), and the operation related to the diagnostic mode is finished. For example, when there is a rotating part determined to be deteriorated, information specifying the rotating part is displayed on the display unit 10 . The user can visually recognize this information on the display unit 10, and by replacing or repairing deteriorated rotating parts, the weighing performance of the weighing device 1 can be maintained in good condition and the weighing accuracy can be maintained. Further, when parts are replaced or repaired in this manner, it is desirable to reset (update) the initial variation amount stored in the initial variation amount storage unit 74 . The resetting of the initial variation amount may be performed only for the rotating parts that have been replaced or repaired, or may be performed for all the initial variation amounts in the initial variation amount storage unit 74 .

Hereinafter, the deterioration determination process of the deterioration determination unit 75 executed in step S206 of FIG. Deterioration determination processing for determining deterioration of each rotating part constituting the transport unit 3 based on the initial amount of variation C related to the vibration component of the part will be described with specific examples.

Here, the conveying unit 3 is configured by connecting three rotating parts of the conveying belt 32b, the driving motor 12, and the roller 32c. A double value (3σ value) shall be used. It is also assumed that the initial variation amount storage unit 74 stores initial variation amounts associated with three stages of conveying speeds (V ₁ to V ₃ ) of the conveying belt 32b. Further, it is determined whether or not there is a rotating part that has deteriorated to such an extent that the weighing apparatus ₁ as a whole cannot satisfy the required accuracy for the currently set conveying speed V2.

There are three rotating parts that constitute the transport unit 3, namely, the transport belt 32b, the drive motor 12, and the rollers 32c. By executing the capture mode, the initial variation storage unit 74 stores the initial 3σ values of the transport belt 32b, the drive motor ₁₂ , and the roller 32c at the transport speed V1, the transport belt _32b at the transport speed V2, the drive motor 12 and the initial 3σ values of the rollers 32c, and initial 3σ values of the transport belt 32b _, the drive motor 12, and the rollers 32c at the transport speed V3.

_In this state, the diagnosis mode is started and, for example, when the transport belt 32b is operated at the transport speed V2, the deterioration determination unit 75 stores the transport belt 32b, the drive motor ₁₂ , and the rollers 32c at the transport speed V2. is supplied from the vibration measuring section 71b. Further, since the transport belt 32b is driven at the transport speed V2, the deterioration determination unit 75 reads the initial 3σ values of _each of the transport belt 32b, the drive motor ₁₂ , and the roller 32c at the transport speed V2.

The deterioration determination unit 75 multiplies these 3σ values by attenuation coefficients, and from the current 3σ values of _each of the conveying belt 32b, the drive motor 12, and the rollers 32c at the conveying speed V2, the following attenuation coefficient multiplication processing: is calculated, and from the initial _3σ values of _each of the conveying belt 32b, the drive motor 12, and the roller 32c at the conveying speed V2, the 3σ value after the attenuation coefficient multiplication process ( The initial 3σ _F value) is calculated.

Further, the deterioration determination unit 75 reads the threshold TH from the threshold storage unit 76 . This threshold value TH is a value obtained, for example, from the required accuracy required for the objects W to be weighed that _are conveyed at the conveying speed V2.

The deterioration determination unit 75 can perform deterioration determination processing based on these values. FIGS. 7A to 7C show an example of visualizing the calculation and deterioration judgment related to the deterioration judgment process.

In FIGS. 7A to 7C, the 3σ _F value for each rotating portion is represented by the vertical length of the box-shaped graphic element. On the other hand, the horizontal length of a box-shaped graphic element has no mathematical meaning. The graphic elements representing the 3σ _F values of the conveying belt 32b, the drive motor 12, and the rollers 32c include character strings of "belt,""motor," and "roller," respectively. In addition, the character string "(INT)" is described in the graphic element representing the initial 3σ _F value, and the character string "(CUR)" is described in the graphic element representing the current 3σ _F value. there is

The “variation amount B measured in advance” is the initial weighing error amount of the weighing device 1 as a whole. For example, the total sum of the initial 3σ _F -values of the conveying belt 32b, the drive motor 12, and the roller 32c can be regarded as the "variation amount B measured in advance". The "variation amount B measured in advance" corresponds to the sum of the vertical lengths of the graphic elements of the belt (INT), motor (INT), and roller (INT) in FIG. 7(A).

Here, a supplementary explanation will be given on the amount of variation representing the weighing error associated with the vibration component corresponding to each rotating portion when the conveying section 3 composed of a plurality of connected rotating portions is operated. In general, mean and variance are additive for independent events. However, in the case where the transportation unit 3 of the weighing device 1 according to the present invention is composed of a plurality of connected rotating parts, the weighing error related to the vibration component of each rotating part is simply calculated by each statistic. Addition and subtraction operations are not evaluated accurately. On the other hand, when determining the deterioration of the rotating part based on the weighing signal output in the absence of the object W to be weighed in the transport unit 3 that operates under a specific structure and operating conditions, the transport unit 3 Since it is sufficient to evaluate only the variation on the time series, the independence between each statistic is not emphasized. Regarding the use of the standard deviation as a statistic representing the variation, it is preferable in that the reference variation amount can be set in the same dimension (unit) as the measurement value. do.

The “initial variation amount C related to the vibration component of a certain rotating part” is the initial measurement error amount related to the vibration component of a certain rotating part of the transport unit 3 (rotation part to be determined). For example, the initial 3σ _F value of each of the conveying belt 32b, the drive motor 12, and the roller 32c can be regarded as "an initial amount of variation C related to the vibration component of a certain rotating portion". The "initial variation amount C related to the vibration component of a certain rotating part" corresponds to the vertical length of each graphic element of the belt (INT), the motor (INT), and the roller (INT) in FIG. 7(A). do.

The “current variation amount A related to the vibration component of a certain rotating part” is the current measurement error amount related to the vibration component of a certain rotating part of the transport unit 3 (rotation part to be determined). For example, the current 3σ _F value of each of the conveying belt 32b, drive motor 12, and roller 32c can be regarded as "the current variation amount A related to the vibration component of a certain rotating part". The "current variation amount A related to the vibration component of a certain rotating part" corresponds to the vertical length of each graphic element of the belt (CUR), motor (CUR), and roller (CUR) in FIG. 7(B). do.

As described above, the deterioration determination unit 75 subtracts the "initial variation amount C related to the vibration component of a certain rotating part" from the "previously measured variation amount B" to obtain the "current A value (that is, B−C+A) obtained by adding the amount of variation A” is calculated, and the result of the calculation is compared with a threshold. It can be determined that FIG. 7C shows "BC+A" when each of the conveying belt 32b, the driving motor 12, and the roller 32c is to be determined.

As shown in FIG. 7(C), "BC+A" in the case where the determination target is the conveyor belt 32b is the sum of the vertical direction of each graphic element of the belt (CUR), the motor (INT), and the roller (INT). Become. This sum exceeds the threshold TH, and the deterioration determination unit 75 determines that the conveying belt 32b has deteriorated.

As shown in FIG. 7(C), when the determination target is the driving motor 12, "B−C+A" is the sum of the vertical direction of each graphic element of the belt (INT), the motor (CUR), and the roller (INT). Become. This sum does not exceed the threshold TH, and the deterioration determination unit 75 determines that the drive motor 12 has not deteriorated.

As shown in FIG. 7(C), "BC+A" when the determination target is the roller 32c is the vertical sum of the graphic elements of the belt (INT), motor (INT), and roller (CUR). . This sum does not exceed the threshold TH, and the deterioration determination unit 75 determines that the roller 32c has not deteriorated.

As described above, in the example of FIGS. 7A to 7C, the deterioration determination process determines that the transport belt 32b has deteriorated, but the drive motor 12 and the roller 32c have not deteriorated. The deterioration determination unit 75 can cause the display unit 10 to display the determination result that the conveyor belt 32b is deteriorated, and as a result, prompt replacement or repair of the conveyor belt 32b. For example, when the conveyor belt 32b is replaced with a normal one, the current 3σ _F value of the conveyor belt 32b returns to a level equivalent to the initial 3σ _F value of the conveyor belt 32b. can improve the weighing performance and weighing accuracy of

In addition, FIGS. 8A to 8C show another example of visualizing the calculation and deterioration judgment related to the deterioration judgment process. 8(A)-(C) differ from FIGS. 7(A)-(C) only in that the current 3σ _F -value of drive motor 12 is larger.

As shown in FIG. 8(C), "B−C+A" when the object of determination is the conveying belt 32b is the sum of the vertical direction of each graphic element of the belt (CUR), the motor (INT), and the roller (INT). Become. This sum exceeds the threshold TH, and the deterioration determination unit 75 determines that the conveying belt 32b has deteriorated.

As shown in FIG. 8(C), when the determination target is the drive motor 12, "BC+A" is the vertical sum of the belt (INT), motor (CUR), and roller (INT) graphic elements. Become. This sum exceeds the threshold TH, and the deterioration determination unit 75 determines that the drive motor 12 has deteriorated.

As shown in FIG. 8(C), "BC+A" when the determination target is the roller 32c is the vertical sum of the graphic elements of the belt (INT), motor (INT), and roller (CUR). . This sum does not exceed the threshold TH, and the deterioration determination unit 75 determines that the roller 32c has not deteriorated.

As described above, in the examples of FIGS. 8A to 8C, the deterioration determination process determines that the conveying belt 32b and the drive motor 12 have deteriorated, but the roller 32c has not deteriorated. The deterioration determination unit 75 displays the determination result that the conveyor belt 32b and the drive motor 12 are deteriorated on the display unit 10, and as a result, prompts replacement or repair of the conveyor belt 32b and the drive motor 12. FIG. For example, when the transport belt 32b and the drive motor 12 are replaced with normal ones, the current 3σ _F -values of the transport belt 32b and the drive motor 12 are the same as the initial 3σ _F -values of the transport belt 32b and the drive motor 12. Since it returns to the same degree, the weighing performance and weighing accuracy of the weighing device 1 as a whole can be improved.

The examples of FIGS. 7A to 7C show the case where it is determined that any one of the belt (INT), motor (INT), and roller (INT) has deteriorated, and FIG. ) to (C) show cases where it is determined that two of the belt (INT), motor (INT), and roller (INT) have deteriorated. It should be noted that there is a case where "B−C+A" when each of the conveying belt 32b, the driving motor 12, and the roller 32c is the object of determination, and all of them exceed the threshold value TH. 12, it is determined that all of the rollers 32c have deteriorated. Further, there is a case where "BC+A" does not exceed the threshold TH when each of the conveying belt 32b, the driving motor 12, and the roller 32c is determined. 12, it is determined that none of the rollers 32c have deteriorated.

As described above, the weighing apparatus 1 according to the present embodiment supports the conveying section 3 configured by a plurality of connected rotating parts, and based on the load of the conveying section 3 and the object W to be weighed, and a weighing unit 72 for processing the weighing signal to calculate the weight value of the object W to be weighed. Based on the weighing signal output by the weighing unit 21 when the conveying means 3 is operated in a state where there is no an initial variation amount storage unit 74 for calculating a variation amount representing a weighing error associated with a vibration component corresponding to each of the plurality of measured rotating parts and storing it as an initial variation amount; Based on the amount of variation representing the weighing error related to the vibration component measured by the vibration measuring unit 71b for the part, the amount of initial variation with respect to other rotating parts among the plurality of rotating parts, and the preset reference amount of variation. and a deterioration determination unit 75 that determines deterioration of one rotating part and outputs a determination result.

With this configuration, it is possible to determine whether the plurality of rotating parts that constitute the conveying unit 3 are in a deteriorated state in which the accuracy required for weighing the objects W to be weighed cannot be satisfied. The determination can be made based on the initial variation value and the reference variation value stored for the part. Therefore, by replacing or repairing only the rotating portion that has deteriorated due to wear or looseness, the weighing performance of the weighing device 1 can be maintained in good condition and the weighing accuracy can be maintained. By detecting deterioration of rotating parts at an early stage, it is possible to avoid production stoppages due to failures and reduce downtime of the production line.

Further, in the weighing device 1 according to the present embodiment, the deterioration determination unit 75 determines deterioration of each of the plurality of rotating parts, and operates the transport unit 3 in a state in which there is no object W to be weighed on the transport unit 3. The amount of variation representing the weighing error associated with the weighing signal output by the weighing unit 21 is calculated, and the amount of variation of one rotating portion to be determined is added to the amount of variation to obtain the initial variation of the rotating portion. It is characterized by subtracting the amount to determine the deterioration of each rotating part.

With this configuration, the deterioration determination unit 75 subtracts the “initial variation amount C related to the vibration component of a certain rotating part” from the “previously measured variation amount B” to obtain the “current Based on the value (B−C+A) obtained by adding the amount of variation A”, deterioration of the rotating part to be determined can be determined.

Further, the weighing apparatus 1 according to the present embodiment is characterized in that the reference amount of variation is set based on an allowable error range for the weighed value of the object W in the weighing section 21 .

With this configuration, it is possible to determine the deterioration of each rotating part that constitutes the conveying unit 3 according to the tolerance defined by the accuracy grade of weighing required for the weighing unit 21 or the test scale.

Further, in the weighing device 1 according to the present embodiment, the variation amount representing the weighing error related to the vibration component corresponding to any one of the plurality of rotating parts is used as the initial variation amount of the rotating part. It is characterized by being stored in the storage unit 74 .

With this configuration, the initial variation amount stored in the initial variation amount storage unit 74 can be updated to the newly measured variation amount related to the vibration component and stored for the rotating part that has been replaced or repaired. will be able to

Further, the weighing device 1 according to the present embodiment is characterized in that the initial variation amount associated with each of a plurality of different conveying speeds realized by the conveying unit 3 is stored in the initial variation amount storage unit 74. .

With this configuration, it is possible to easily determine the deterioration of each rotating portion of the conveying section 3 corresponding to the types of the plurality of objects W to be weighed associated with each of the plurality of conveying speeds.

As described above, the weighing device according to the present invention has the effect of being able to identify the rotating part of the conveying means that causes the failure to satisfy the accuracy required for weighing the object to be weighed. It is useful as a weighing device that weighs objects such as meat, fish, processed foods, and pharmaceuticals while transporting them to determine the quality of the objects.

REFERENCE SIGNS LIST 1 weighing device 2 device main body 2a storage housing 3 transport unit (transport means)
4 carry-in sensor 4a light projecting section 4b light receiving section 5 sorting section 5a sorting mechanism section 5b sorting conveyor 5c, 31a, 31c, 32a, 32c rollers 5d, 31b, 32b transport belt 7 general control section 10 display section 11 operation section 12 drive motor 13 Conveyance control section 14 Belt conveyor 21 Weighing section (weighing means)
31 run-up conveyor 32 weighing conveyor 71 signal processing section 71a filter processing section 71b vibration measuring section (vibration measuring means)
72 weighing unit (weighing means)
73 Quality determination section 74 Initial variation amount storage section (initial variation amount storage means)
75 deterioration determination unit (deterioration determination means)
76 threshold storage unit 77 filter setting unit 80 mode switching unit W object to be weighed

Claims (5)

Weighing means for supporting conveying means composed of a plurality of connected rotating parts, for outputting a weighing signal based on the weight of the conveying means and the load of the object to be weighed, A weighing device comprising weighing means for calculating a weighing value of an object to be weighed,
Vibration components corresponding to each of the plurality of rotating parts are measured based on the weighing signal output by the weighing means when the conveying means is operated without the object to be weighed on the conveying means. a vibration measuring means;
initial variation amount storage means for calculating an amount of variation representing a weighing error associated with each of the vibration components corresponding to each of the plurality of rotating parts measured in advance by the vibration measuring means and storing the amount as an initial variation amount;
A variation amount representing a weighing error related to the vibration component measured by the vibration measuring means for one rotating portion of the plurality of rotating portions, and the initial variation for other rotating portions of the plurality of rotating portions. and deterioration determining means for determining deterioration of the one rotating portion based on the amount and a preset reference variation amount, and outputting a determination result. The deterioration determining means determines deterioration of each of the plurality of rotating parts, and the weighing amount output by the weighing means when the conveying means is operated without the object to be weighed on the conveying means. A variation amount representing a weighing error related to a signal is calculated, the variation amount of one rotating part to be determined is added to the variation amount, the initial variation amount of the rotating part is subtracted, and each rotating part 2. The weighing device according to claim 1, wherein the deterioration of the 3. The weighing apparatus according to claim 1, wherein the reference amount of variation is set based on an allowable error range for the weighed value of the object to be weighed by the weighing means. An amount of variation representing a weighing error associated with a vibration component corresponding to one of the plurality of rotating parts is stored in the initial variation amount storage means as the initial amount of variation of the rotating part. Weighing device according to any one of claims 1 to 3. 5. The apparatus according to any one of claims 1 to 4, wherein the initial variation amount associated with each of a plurality of different transport speeds realized by the transport means is stored in the initial variation amount storage means. Weighing device.

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