JP2015064270A - Weight display device and adjustment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To do away with need to newly perform adjustment work for acquiring conversion information for performing conversion into a weight value in a replaced new weight display device when replacing a weight display device 3, in the weight display device 3 adding digital load signals inputted from a plurality of digital load cells 2a-2d, performing the conversion into the weight value, and displaying it.SOLUTION: Adjustment work for acquiring conversion information for converting added digital load signals into a weight value is performed, and the obtained conversion information is stored in a nonvolatile storage medium 13 attachable/detachable to/from a weight display device 3. When replacing the weight display device 3 with a new weight display device, the nonvolatile storage medium 13 is detached, and is attached to the new weight display device.

Description

  The present invention adds a digital load signal input from a plurality of digital load cells to convert it into a weight value, displays a weight value on a display unit, and converts the added digital load signal into a weight value The present invention relates to an adjustment device used for adjustment work for acquiring conversion information for the purpose.

  A weighing hopper that accommodates an object to be weighed and a weighing platform on which an object to be weighed is placed are supported by a plurality of digital load cells, and the digital load signals of the plurality of digital load cells are added. Examples of the weighing device that converts the weight value of the object to be weighed and displays the weight value include a hopper scale and a track scale (see, for example, Patent Document 1).

  In general, a digital load cell is integrated with an analog load cell, a circuit board equipped with an amplifier that amplifies an analog load signal from the analog load cell, an A / D converter that converts the amplified analog load signal into a digital load signal, and the like. And an analog load signal from an analog load cell is output as a digital load signal.

  In such a digital load cell, in the adjustment process at the time of production, an adjustment is performed to adjust the span coefficient so that a load signal having a magnitude corresponding to the rated load is output with respect to the load of the rated load using a load test device. Work is done. At that time, the obtained span coefficient is stored in a nonvolatile memory on the circuit board of the digital load cell.

  In this way, a plurality of digital load cells whose spans are adjusted at the time of manufacture are combined to weigh the object to be weighed on the weighing table. For example, in a track scale, four digital load cells are arranged at the four corners of a rectangular weighing table. The digital load signal from each digital load cell is input to an indicator which is a weight display device, the digital load signal from each digital load cell is added by the indicator, and the added digital load signal is added to the weighing object. It is converted into the weight value of the object and displayed.

  In such a track scale, it is difficult to accurately arrange the digital load cells that support the weighing platform at the four corners of the rectangle according to the dimensions, so that the load is not applied equally to the digital load cells.

  In addition, each digital load cell is span-adjusted so as to output a load signal having a magnitude corresponding to the load of the rated load as described above. However, the weight applied to each digital load cell from the viewpoint of safety. The range is a weight range smaller than the rated load of each digital load cell.

  Each digital load cell outputs different digital load signals at loads other than the rated load. Furthermore, each digital load cell has its own non-linearity and hysteresis characteristics. When the digital load signal from each digital load cell is added with the indicator and converted into a weight value, the error that appears in the weight value is small. Thus, for example, it is necessary to perform adjustment work for determining conversion information such as a span coefficient related to output characteristics and a nonlinear compensation function.

  In this adjustment operation, the weight of the reference weight is placed on the weighing table, and the digital load signal obtained by adding the digital load signal from each digital load cell is converted into a weight value corresponding to the reference weight of the weight, for example, The conversion information such as the span coefficient is determined, and the obtained conversion information such as the span coefficient is stored in the storage unit of the indicator.

  After the adjustment work is completed, during operation of weighing the weight of the object to be weighed, the indicator adds the digital load signal input from each digital load cell, and the added digital load signal is stored in the storage unit. It is converted into a weight value using conversion information such as a span coefficient and displayed on the display unit.

JP 2002-243562 A

  If parts on the circuit board of the indicator break down and need to be replaced with a new indicator or a new circuit board, a new indicator can be installed even if there are no changes on the multiple digital load cells. After connecting to multiple digital load cells or replacing with a new circuit board, the weight of the reference weight is placed on the weighing platform, and the digital load signal added with the digital load signal from each digital load cell is the reference weight of the weight. The adjustment work for obtaining conversion information such as a span coefficient has to be performed again so that the weight value is converted to the weight value corresponding to.

  This adjustment work must be performed using a heavy weight, especially in the case of weighing devices that measure the weight of large and heavy objects such as the above-mentioned truck scales and hopper scales. There is a problem that it takes time.

  In Patent Document 1, it is described that one of a plurality of digital load cells is used as a master load cell, and load signals from other digital load cells are added. However, the added load signal is set to an accurate weight value. There is no disclosure at all regarding the handling of conversion information storage obtained in the adjustment work to be converted, that is, when the circuit board component of the master load cell fails and the circuit board with information on other load cells is replaced. Therefore, the above problem cannot be solved.

  The present invention has been made paying attention to the above situation, and a weight display device that converts a digital load signal into a weight value using conversion information is used as a new weight display device or a new circuit board. It is an object of the present invention to eliminate the need to perform adjustment work for acquiring conversion information with a new weight display device in the case of replacement.

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

(1) The weight display device of the present invention detects the load of the object to be weighed by a plurality of digital load cells, adds the digital load signals input from the plurality of digital load cells, and adds the added digital load signal to the measured weight. A weight display device for converting and displaying the weight value of a weighing object,
A non-volatile storage medium storing conversion information for conversion to the weight value is provided, and the non-volatile storage medium is detachable from the weight display device.

  According to the present invention, digital load signals input from a plurality of digital load cells are added, and conversion information for converting the added digital load signals into weight values is non-volatile that can be attached to and detached from the weight display device. Since it is stored in the storage medium, by performing the adjustment work for obtaining the conversion information once and storing the obtained conversion information in the nonvolatile storage medium, for example, the weight display device breaks down. When replacing with a new weight display device, the non-volatile storage medium storing the conversion information is removed and attached to the new weight display device, so that the new weight display device is stored in the non-volatile storage medium. Conversion information can be used, so that the new weight display device does not need to be re-adjusted to obtain the conversion information.

  (2) In a preferred embodiment of the present invention, a conversion for calculating the conversion information based on digital load signals input from a plurality of digital load cells when a load of an object having a reference weight is detected by the plurality of digital load cells. Information calculation means is provided.

  The reference weight is preferably, for example, a rated load of a weighing device including the weight display device, and the reference weight is not limited to one, and may be a plurality. The reference weight object is preferably a weight.

  According to this embodiment, the load of an object having a reference weight is detected by a plurality of digital load cells, the digital load signals input from the respective digital load cells are added, and the added digital load signal is converted into the value of the reference weight. Thus, conversion information can be calculated.

  (3) In another embodiment of the present invention, the plurality of digital load cells support a weighing table on which the object to be weighed is placed or a weighing container in which the object to be weighed is accommodated.

  According to this embodiment, it is suitable for a weighing device in which an object to be weighed is placed on a weighing platform, for example, a weighing device in which an object to be weighed is accommodated in a truck scale or a weighing container, for example, a hopper scale.

  (4) In still another embodiment of the present invention, the conversion information includes a span coefficient.

  According to this embodiment, digital load signals input from a plurality of digital load cells can be added, and the added digital load signals can be converted into weight values using a span coefficient included in the conversion information.

(5) The adjustment device of the present invention detects the load of the object to be weighed by a plurality of digital load cells, adds the digital load signals input from the plurality of digital load cells, and adds the added digital load signal to the weighing object. An adjustment device for acquiring conversion information for converting to a weight value of an object,
A plurality of storage means for storing the conversion information in duplicate;
The plurality of storage means include a nonvolatile storage medium that can be attached to and detached from the adjustment device.

  According to the present invention, digital load signals input from a plurality of digital load cells are added, conversion information for converting the added digital load signals into weight values is acquired, and redundantly stored in a plurality of storage means, Since the plurality of storage means include a nonvolatile storage medium that can be attached to and detached from the adjusting device, this nonvolatile storage medium is used as the nonvolatile storage medium of the weight display device of the above (1) to (4). be able to. For example, the conversion information is acquired exclusively by the adjustment device, and the nonvolatile storage medium storing the acquired conversion information is removed from the adjustment device and attached to the weight display device. You may omit the adjustment operation | work which measures a to-be-measured object using the conversion information memorize | stored in the storage medium, and acquires conversion information.

  Further, since the conversion information acquired by the adjustment device is also redundantly stored in other storage means other than the non-volatile storage medium, the non-volatile storage medium of the adjustment device is removed and attached to the weight display device. Even in the case of using in the above, the conversion information stored in the other storage means can be read and used. As a result, for example, it is possible to read the conversion information acquired using the adjusting device for each weighing device from the other storage means of the adjusting device and manage them collectively by an external information management device. Become.

  Thus, according to the present invention, digital load signals input from a plurality of digital load cells are added, and conversion information for converting the added digital load signals into weight values is provided to the weight display device. Since it is stored in a detachable non-volatile storage medium, an adjustment operation for acquiring conversion information is performed once, and the obtained conversion information is stored in the non-volatile storage medium, for example, the weight display If the device fails and is replaced with a new weight display device, the non-volatile storage medium storing the conversion information may be removed and attached to the new weight display device. Thus, in the new weight display device, the weighing object can be weighed using the conversion information stored in the non-volatile storage medium, and there is no need to perform adjustment work for acquiring the conversion information again. .

It is a block diagram which shows schematic structure of a track scale provided with the indicator which concerns on embodiment of this invention. It is a figure which shows the installation state of the weighing scale of the track scale of FIG. It is a perspective view which shows the mounting state of the non-volatile memory of FIG. It is a figure for demonstrating the influence on the digital load cell by the bending of a weighing platform. It is a figure for demonstrating the function for correct | amending the nonlinearity of an output characteristic. It is a block diagram which shows schematic structure of a digital load cell and an adjustment apparatus. It is a figure which shows schematic structure of a hopper scale.

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

  In this embodiment, description will be made by applying to a track scale as a weighing device. FIG. 1 is a block diagram showing a schematic configuration of the track scale 1.

  The track scale 1 has a plurality of, in this example, four digital load cells 2a to 2d, and a weight display for adding a digital load signal from each of the digital load cells 2a to 2d to convert it into a weight value and displaying the weight value. An indicator 3 as a device is provided.

  Each of the digital load cells 2a to 2d is a compression type load cell that supports a rectangular weighing platform 4 on which a weighing object such as a vehicle shown in FIG. Each of the digital load cells 2a to 2d has the same configuration, and has an analog load cell in which a plurality of strain gauges are attached to a columnar strain generating body and an analog load signal is output from these strain gauges. . A circuit board is mounted on the strain generating body of the analog load cell, and a weight measurement arithmetic circuit and the like are mounted on the circuit board.

  That is, as shown in FIG. 1, each of the digital load cells 2a to 2d includes operational amplifiers 5a to 5d for amplifying the analog load signals from the analog load cells 2a 'to 2d' and analog load signals from the operational amplifiers 5a to 5d. A / D converters 6a to 6d for converting digital load signals, arithmetic units 7a to 7d composed of a CPU and a memory for arithmetic processing of the digital load signals, and serial communication controllers 8a to 8d are provided. The serial communication controllers 8 a to 8 d of the digital load cells 2 a to 2 d are connected to the serial communication controller 10 of the indicator 3 through a common serial transmission line 9.

  The indicator 3, which is a weight display device, performs operations such as calculation of conversion information for addition to the serial communication controller 10 and addition of digital load signals from the digital load cells 2a to 2d and conversion into weight values for display. A calculation control unit 11 composed of a CPU for controlling, a storage unit 12 for temporarily storing data for calculation, a control program and the like, and a digital load signal of each of the digital load cells 2a to 2d are added. Nonvolatile memory 13 for storing conversion information for conversion into weight values, setting input unit 14 for setting data, operation commands, and the like, and a display unit for displaying weight values calculated by calculation control unit 11 15 and an input / output circuit (I / O) circuit 16.

  The non-volatile memory 13 which is a non-volatile storage medium is composed of, for example, an EEPROM or the like, and as shown in FIG. 3, a circuit board 17 on which a CPU or the like constituting the arithmetic control unit 11 inside the case of the indicator 3 is mounted. The IC socket 18 is detachably mounted.

  Since the nonvolatile memory 13 such as an EEPROM is thus detachably mounted on the circuit board 17 via the IC socket 18, it can be easily exchanged with a chip of another nonvolatile memory 13.

  Each of the digital load cells 2a to 2d is subjected to span adjustment so that a digital load signal Wm ′ corresponding to the predetermined rated load M ′ can be obtained at the time of manufacture by applying a predetermined rated load M ′. The span coefficient is stored in a non-volatile memory provided on a circuit board integrally attached to each of the digital load cells 2a to 2d.

The digital load cells 2a to 2d individually adjusted in span as described above are incorporated in the weighing platform 1 as shown in FIG. Assuming Wa4, these digital load signals Wa1 to Wa4 are read into the operation control unit 11 of the indicator 3 via the serial transmission line 9. The arithmetic control unit 11 adds the digital load signals Wa1 to Wa4 as the combined load signal Wa representing the weight value on the weighing platform 4, and
Wa = Wa1 + Wa2 + Wa3 + Wa4 (1)
Ask for.

  Note that the digital filter calculation for removing vibration noise and the like contained in the digital load signal may be performed individually in the calculation units 7a to 7d of the digital load cells 2a to 2d, or the calculation of the indicator 3 In the control part 11, you may perform with respect to the synthetic | combination load signal Wa.

  Each digital load cell 2a-2d has already been adjusted in span as described above at the time of manufacture. However, after each digital load cell 2a-2d is incorporated in the weighing platform 4 and connected to the indicator 3, It is necessary to adjust the span again for the combined load signal obtained by adding the digital load signals from the load cells 2a to 2d.

  The reason will be described in detail.

  Assuming that the rated load of the weighing device is M with respect to the weighing table 4 in FIG. 2, when the weighing device is the track scale 1, the load is equally distributed to each of the digital load cells 2a to 2d by 1/4. Thus, the load is not placed on the weighing table 4 but placed on any of the digital load cells so that the load is biased. Therefore, a load load greater than 1/4 of the rated load M is applied to one digital load cell. In consideration of the fact that the load rating of each of the digital load cells 2a to 2d is larger than 1/4 of the load rating M of the track scale 1 that is a weighing device.

  Each of the digital load cells 2a to 2d is span-adjusted between the rated load and the zero load as the load cell. However, since the output characteristics thereof are non-linear, if a load other than the rated load is applied, some inherent load An error is generated.

  In addition, when the digital load cells 2a to 2d are incorporated in the weighing table 4 and the span is adjusted as a weighing device, a weight having a rated load M is evenly applied to the digital load cells 2a to 2d on the weighing table 4. Thus, even if the weight M is loaded, that is, even if the load is 1/4 of the rated load M, each digital load cell 2a to 2d is caused by an inherent error of each digital load cell 2a to 2d. The added value of the output of 2d is not exactly M.

  Also, as exaggeratedly shown in FIG. 4 (a), when the vehicle 19 which is an object to be weighed is loaded on the weighing table 4, the weighing table 4 made of an iron plate or the like bends, whereby each digital load cell 2a. .About.2d are inclined from the vertical direction, and bending stress is applied to the strain generating body of the digital load cell 2a as representatively shown in FIG.

  When the strain generating body is inclined as described above, the magnitude of the output value of the digital load signal of each of the digital load cells 2a to 2d with respect to a predetermined load is different according to the bending strain characteristic of each of the digital load cells 2a to 2d.

  For the reasons described above, the weight value of the object to be weighed on the weighing platform 4 cannot be accurately represented simply by adding the output values of the digital load signals of the digital load cells 2a to 2d. For this reason, a combined weight signal obtained by placing a weight of a reference weight on the weighing platform 4 of the track scale 1 as a weighing device and adding the digital load signals of the respective digital load cells 2a to 2d is the value of the reference weight of the weight. It is necessary to set a span coefficient as conversion information so that it is converted into.

  An adjustment operation for setting the span coefficient for the composite load signal will be described. At the time of this adjustment, the composite load signal Wa is displayed on the display unit 15 of the indicator 3.

  First, the operator confirms that no article is placed on the weighing table 4 and operates the setting input unit 14 to input an initial load storage command.

The value of the composite load signal Wa at this time is stored in the nonvolatile memory 13 as the initial weight value Wi, and the internal weight value Wn for display is Wn = (Wa−Wi) (2)
It expresses. The initial weight value Wi is a tare load such as the weight of the weighing table 4.

  In order to obtain a display weight value representing the weight value of the object to be weighed placed on the weighing table 4, the span coefficient Km for the composite load signal is set as follows.

  The reference weight value M of the weight, which is the rated load, is set and input from the setting input unit 14 in advance.

A weight having a reference weight value M, which is a rated load of the track scale 1, is placed on the weighing table 4. If the magnitude of change of the digital load signal Wa due to the weight of the weight of the reference weight value M is Wm, the value of the digital load signal Wa is an added value of the load signal part Wm by the weight and the load signal part Wi by the initial load. In the above equation (2), the weight value Wn for displaying only the weight is
Wn = (Wa−Wi) = Wm + Wi−Wi = Wm (3)
The weight value Wn for display corresponds to the value of Wm, which is the change in the digital load signal due to the weight load. During the adjustment, the display weight value Wn is displayed on the display unit 15.

When the operator inputs a span adjustment command when the weight value of the display unit 15 is stabilized, in other words, a span adjustment information calculation command for the track scale 1 by operating the setting input unit 14, the value of Km / Wm is obtained. Is a span coefficient Km so as to represent the value of the weight M,
Km = Wn / Wm = M / Wm (4)
In the weighing operation of the object to be weighed by the truck scale 1, the display weight value Wn inside the indicator 3 is
Wn = Km (Wa-Wi) (5)
Is calculated and displayed. The value of the span coefficient Km is stored in the nonvolatile memory 13 attached to the IC socket 18 when Km is calculated.

  The span coefficient Km is a span coefficient for the track scale 1, and is conversion information for converting a combined load signal obtained by adding the digital load signals from the digital load cells 2a to 2d into a display weight value.

Normally, the display weight value Wn inside the indicator is obtained by an A / D conversion value having a resolution that is four times higher than the display weight value Wd displayed on the display unit 15, and has a resolution four times as high. If required, the display weight measurement value Wd used for displaying the weight of the object to be weighed as a weighing device in the display unit 15 is:
Wd = Wn / 4 (6)
And calculate and derive.

  As described above, after the adjustment of the span coefficient for the composite load signal of the track scale 1 is completed, the weighing device 3 performs the weighing operation of the object to be weighed by the track scale 1 in the indicator 3 from each of the digital load cells 2a to 2d. A composite load signal is generated by adding the digital load signal, and this composite load signal is converted into a weight value for display using a span coefficient Km for the composite load signal which is conversion information stored in the nonvolatile memory 13. Is displayed on the display unit 15.

  When a part other than the non-volatile memory 13 of the indicator 3 fails and the indicator 3 is replaced, the non-volatile memory 13 of the failed indicator 3 is removed from the IC socket 18 of the circuit board 17, and a new instruction Attach to the IC socket on the circuit board of the meter.

  Thereby, in the new indicator, the adjustment operation for setting the span coefficient for the composite load signal is omitted, and the weighing operation of the object to be weighed by the track scale 1 is started immediately. That is, in the new indicator, a digital load signal from each of the digital load cells 2a to 2d is added to generate a composite load signal, and this composite load signal is removed from the failed indicator 3 and attached to the nonvolatile memory. The composite weight signal span coefficient, which is conversion information stored in the memory 13, can be converted into a display weight value and displayed on the display unit 15.

  Thus, when the indicator 3 breaks down and is replaced with a new indicator, it is only necessary to remove the nonvolatile memory 13 of the failed indicator 3 and attach it to the new indicator, and determine the span coefficient for the composite load signal. It is not necessary to carry out the adjustment work again.

  As a result, the adjustment work for determining the span coefficient by placing a heavy weight on the weighing table can be omitted, so that the cost and time required for replacing the indicator can be reduced.

  In the above embodiment, only the span coefficient for the composite load signal is stored in the nonvolatile memory 13 as the conversion information. However, as another embodiment of the present invention, the unique non-linear characteristics of the digital load cells 2a to 2d are provided. Conversion information for correcting and converting may be acquired as follows and stored in the nonvolatile memory 13.

  Since each of the digital load cells 2a to 2d has a specific non-linear characteristic, when the output values of these digital load signals are added, the combined load signal also has a specific non-linearity as shown by a solid curve L1 in FIG. Therefore, correction is required to accurately obtain the display weight value.

  Using the above formula (5), which is a formula for calculating the weight value Wn for internal display, for which the span coefficient Km has been obtained as described above, a load of M / 2 that is ½ of the rated load of the track scale 1 Is placed on the weighing table 4, and the weight value Wn = W2m for the internal display at that time is obtained.

  The operator places a weight having a weight of M / 2 on the weighing table 4 and, when the weight value displayed on the display unit 15 is stabilized, operates the setting input unit 14 to issue a non-linearity correction command. When input, in other words, when a non-linearity correction function calculation command is input, the following calculation is performed using the internal display weight value at the time of command.

That is, since the load when the internal display weight value Wn = W2m is obtained is M / 2, the solid line curve L1 in FIG. 5 is (0, 0), (M / 2, W2m), Assuming that it is a quadratic curve passing through (M, Wm), the function value representing the relationship between the weight value for internal display Wnx and the load Mx on the weighing platform 4 at that time is F (Wnx).
F (Wnx) = Mx = a · Wnx ² + b · Wnx + c (7)
Coefficients a, b and c are determined, and an internal display weight value function is obtained.

  This function represents the characteristic of the total load signal, and the acquired internal display weight value function is stored in the nonvolatile memory 13 inserted in the IC socket 18.

  The above function is conversion information for converting the composite load signal into a weight value for display.

  As described above, after the adjustment for determining the function for the weight value for the composite load signal is completed, when the weighing object is measured by the truck scale 1, the indicator 3 uses the digital load cells 2 a to 2 d. Are combined to generate a combined load signal, which is converted into a display weight value using a display weight value function that is conversion information stored in the nonvolatile memory 13. Specifically, the weight value Mx for display is calculated by substituting Wnx calculated by the formula (5) from the combined load signal Wa into the right side Wnx of the formula (7) and displayed on the display unit 15.

  In the digital load cells 2a to 2d, there is a difference in output value between the process of increasing the load and the process of decreasing the load even if the same load is loaded. For this reason, the combined load signal obtained by adding the digital load signals of the respective digital load cells 2a to 2d has a hysteresis characteristic in which the error changes depending on the history of the loaded load. In order to compensate for this error, for example, as disclosed in Japanese Patent Application Laid-Open No. 2006-30126, a hysteresis function that represents the hysteresis characteristic of the combined load signal as an approximate function at the time of adjustment is obtained. May be stored in the nonvolatile memory 13 inserted into the IC socket 18 as conversion information. During weighing operation of the object to be weighed by the track scale 1, the indicator 3 adds a digital load signal from each of the digital load cells 2a to 2d to generate a combined load signal, and this combined load signal is stored in the nonvolatile memory. 13 may be converted into a display weight value in which the error is corrected using a hysteresis function which is the conversion information stored in 13.

  In each of the embodiments described above, the indicator 3 is connected to each of the digital load cells 2a to 2d, the adjustment information is obtained by performing an adjustment operation, and the conversion information is stored in the nonvolatile memory 13 of the indicator 3. As another embodiment of the invention, adjustment work for obtaining conversion information by the indicator 3 may not be performed.

  That is, instead of the indicator 3, the digital load cells 2 a to 2 d are connected to the adjustment device 25 as shown in FIG. 6. This adjustment device 25 is capable of acquiring a conversion information by placing a weight of a reference weight on the weighing table 4 and performing an adjustment operation, and storing the acquired conversion information. A serial communication controller 28, an arithmetic control unit 29, an I / O circuit 30, a setting input unit 31, a display unit 32, a storage unit 27, and a non-volatile memory 26 that is detachable from an IC socket of an internal circuit board are provided. Yes.

  The adjustment device 25 is a dedicated device that performs adjustment work to acquire conversion information, and does not have a function of weighing an object to be weighed after the adjustment work, and is more compact than the indicator 3. It has become a structure.

  As in the case of the indicator 3, the adjustment device 25 performs adjustment work by placing a weight of a reference weight on the weighing table 4, acquires conversion information, and acquires the acquired conversion information inside the adjustment device 25. The non-volatile memory 26 and the storage unit 27 that can be attached to and detached from the IC socket of the circuit board are redundantly stored. Similarly to the nonvolatile memory 13 of the indicator 3, the nonvolatile memory 26 is composed of, for example, an EEPROM, and is compatible with the nonvolatile memory 13 of the indicator 3.

  The nonvolatile memory 26 of the adjustment device 25 storing the conversion information is removed from the adjustment device 25 and attached as the nonvolatile memory 13 of the indicator 3.

  Then, instead of the adjusting device 25, the indicator 3 equipped with the non-volatile memory 26 is connected to each of the digital load cells 2a to 2d, and the operation of weighing the objects to be weighed is started. The indicator 3 adds a digital load signal from each of the digital load cells 2a to 2d to generate a composite load signal, and uses the conversion information stored in the attached nonvolatile memory 26 to display the composite load signal. Convert to weight value.

  Thereby, the indicator 3 does not need to perform adjustment work for obtaining the conversion information even once.

  By using this adjustment device 25, adjustment work can be performed for each track scale, and conversion information used for the indicator can be obtained for each track scale.

  Since the adjustment device 25 stores the conversion information redundantly in the storage unit 27 other than the non-volatile memory 26, after the adjustment work is completed, the adjustment device 25 is connected to an external information device such as a personal computer. Then, the conversion information in the storage unit 27 of the adjustment device 25 is captured, and the conversion information in the storage unit 27 of the adjustment device 25 is deleted.

  Since the adjustment device 25 acquires conversion information for each of a large number of track scales, the acquired conversion information for each of the track scales can be taken into an external information device such as a personal computer and managed collectively. It becomes. Thereby, for example, when the nonvolatile memory storing the conversion information of the indicator of a certain track scale fails, the certain track scale among the conversion information collectively managed by the external information device It is possible to write conversion information corresponding to the above in a nonvolatile memory, and to restore the nonvolatile memory by exchanging the nonvolatile memory with the nonvolatile memory of the indicator of the certain track scale.

  In each of the above embodiments, the weighing device is described as being applied to the track scale 1. However, the weighing hopper 20 to which an object to be weighed is supplied from above is shown in FIG. A plurality of, in this example, three digital load cells 21a to 21c are suspended and supported, and the weight of an object to be weighed is measured, and the bottom gate 22 is opened to discharge the hopper scale 22 and other weighing devices in the same manner. Applicable.

  In the above embodiment, the EEPROM is used as the nonvolatile storage medium. However, the present invention is not limited to this. For example, a digital value such as a USB memory, a CD-ROM, or a DVD can be stored. Any storage medium that can be configured to be detachable may be used.

  The indicator 3 which is a weight display device may be a personal computer.

  The digital load cell is not particularly limited, and a vibration string is provided between the strain generating portion and the fixed portion of the strain generating body, and the vibration of the string changes according to the magnitude of the tension change applied to the vibration string of the load load. A digital load cell or the like that reads a numerical change as a digital load signal by a counter may be used, and any load cell that directly outputs a digital load signal may be used.

1 truck scale 2a to 2d digital load cell 3 indicator (weight display device)
4 Weighing table 11 Calculation control unit (conversion information calculation means)
13 Non-volatile memory 17 Circuit board 18 IC socket 19 Vehicle 20 Weighing hopper 25 Adjustment device

Claims (5)

The load of the object to be weighed is detected by a plurality of digital load cells, the digital load signals input from the plurality of digital load cells are added, and the added digital load signal is converted into the weight value of the object to be weighed and displayed. A weight display device,
A non-volatile storage medium storing conversion information for conversion into the weight value, the non-volatile storage medium being detachable from the weight display device;
A weight display device characterized by that. Conversion information calculation means for calculating the conversion information based on digital load signals input from a plurality of digital load cells when a load of an object of a reference weight is detected by the plurality of digital load cells;
The weight display device according to claim 1. The plurality of digital load cells support a weighing table on which the object to be weighed is placed or a weighing container in which the object to be weighed is housed.
The weight display device according to claim 1 or 2. The conversion information includes a span coefficient.
The weight display device according to any one of claims 1 to 3. Conversion for detecting the load of an object to be weighed by a plurality of digital load cells, adding digital load signals inputted from the plurality of digital load cells, and converting the added digital load signal into a weight value of the object to be weighed An adjustment device for acquiring information,
A plurality of storage means for storing the conversion information in duplicate;
The plurality of storage means includes a nonvolatile storage medium that is detachable from the adjustment device.
An adjusting device characterized by that.

Images