JP2012127841A - Track scale and vehicle weight measuring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate mismeasurement of vehicle weight.SOLUTION: In a vehicle weight measuring system, when an outer surface 2a of a mount base 2 on which a vehicle is mounted approaches an inner wall 4a of a pit 4 by preset distance in which correct measurement may fail, an advancing and retrieving member 6 configuring a contact point on a mount side disposed on the mount base 2 contacts a conductive plate 7 configuring a contact point on a pit side disposed on the inner wall 4a of the pit 4 to turn a detection switch 5 including the advancing and retrieving member 6 and the conductive plate 7 on to display and alert that the outer surface 2a of the mount base 2 approaches the inner wall 4a of the pit 4 by the preset distance on a display part of an indicator.

Description

  The present invention relates to a truck scale for measuring the weight of a vehicle such as a truck and a vehicle weight measuring system using the same.

  A pit-type track scale generally includes a plurality of load cells and a platform supported by the load cells incorporated in a concrete pit formed by digging down the ground surface, and a truck or the like on the platform incorporated in the pit. The vehicle is mounted and its weight is measured (see, for example, Patent Document 1).

JP 2005-127930 A

  In such a truck scale, the outer periphery of the platform comes into contact with the inner wall of the pit due to secular change or an impact caused by a sudden entry of the vehicle on the platform, and the vehicle remains in this contact state. The weight may be measured.

  It is difficult to determine the presence or absence of the contact state from the weight value of the vehicle being measured. For this reason, conventionally, an inaccurate weight measured in a state where the outer peripheral portion of the platform is in contact with the inner wall of the pit. The value may be mistakenly recognized as being an accurate weight value, that is, erroneously weighed.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a track scale and a vehicle weight measurement system using the same that can prevent the erroneous measurement.

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

 (1) That is, the track scale of the present invention is a track scale in which a mounting table on which a vehicle is mounted and a plurality of load cells that support the mounting table are incorporated in a pit, And a detecting means for detecting that the inner wall of the pit is in contact or close to a set distance, and a detection output of the detecting means is provided to an informing means for informing the contact or the approach.

  The set distance can be an arbitrary distance, but is preferably a distance that may cause a problem in accurate measurement. For example, the distance immediately before the outer peripheral portion of the mounting table touches the inner wall of the pit. Alternatively, the outer peripheral portion of the mounting table may be close to the inner wall of the pit and may be a distance to which a lateral load is exerted that adversely affects the load cell.

  The detection means only needs to be able to detect that the outer peripheral portion of the mounting table is in contact with the inner wall of the pit up to the set distance or contact, and the position where contact or proximity is detected is an arbitrary position on the outer peripheral portion of the mounting table. Although it is preferable to have a plurality of locations, it may be a single location.

  The informing means may be any means that informs that the outer peripheral portion of the platform is in contact with the inner wall of the pit or close to the set distance, for example, by display, sound, or a combination thereof. The notification means may be provided on the track scale, but a weighing device connected to the track scale and calculating and displaying the weight of the vehicle based on outputs of a plurality of load cells may be used as the notification means.

  Further, when the outer peripheral portion of the mounting table is in contact with the inner wall of the pit or close to a set distance, measurement based on the outputs of a plurality of load cells may be prohibited.

  According to the track scale of the present invention, when the outer periphery of the platform on which the vehicle is placed comes close to the inner wall of the pit up to the contact or set distance, the contact or proximity is detected by the detection means, and the notification means Therefore, the user can recognize that the outer periphery of the platform is in contact with or close to the inner wall of the pit and cannot accurately measure, thereby preventing erroneous weighing. can do.

  (2) In another preferred embodiment of the track scale of the present invention, the detection means includes a plurality of detection switches that are turned on / off depending on whether or not the distance to the set distance is close, and each detection switch And a pit side contact installed on the inner wall of the pit so as to face the platform side contact.

  According to this embodiment, when the outer peripheral portion of the mounting table is close to a set distance with respect to the inner wall of the pit, the mounting-side contact of one of the plurality of detection switches contacts the corresponding pit-side contact. The contact can be detected by touching and the output is turned on.

  (3) In another preferred embodiment of the track scale according to the present invention, the platform and the pit are rectangular in plan view, and the plurality of detection switches are respectively near corners at both ends of each side of the rectangle. Installed.

  According to this embodiment, the fact that the outer peripheral portion of the rectangular platform is close to the set distance from the inner wall of the rectangular pit is accurately detected by the plurality of detection switches respectively installed in the vicinity of each corner of the rectangle. Can be detected.

  (4) A vehicle weight measurement system according to the present invention includes the track scale according to the present invention and a weighing device connected to the track scale, and the weighing device is configured based on outputs of the plurality of load cells. In addition, based on the detection output of the detection means, the fact that the outer peripheral portion of the table is in contact with the inner wall of the pit up to the contact or set distance is notified.

  According to the vehicle weight measurement system of the present invention, when the outer peripheral portion of the platform on which the vehicle is placed comes close to the inner wall of the pit up to the contact or set distance, the contact or proximity is detected by the detection means. Since the weighing device notifies the user, the user can recognize that the outer peripheral portion of the platform is in contact with or close to the inner wall of the pit and cannot perform accurate weighing. Can be prevented.

  According to the present invention, when the outer periphery of the platform on which the vehicle is placed is in contact with the inner wall of the pit or close to the set distance, it can be detected by the detection means and notified by the notification means. The user can recognize that the outer peripheral portion of the mounting table is in a state where accurate weighing cannot be performed in contact with or close to the inner wall of the pit, thereby preventing erroneous weighing.

FIG. 1 is a plan view of an installed state of a track scale according to an embodiment of the present invention. FIG. 2 is a side view of FIG. FIG. 3 is an enlarged plan view showing a corner portion of FIG. FIG. 4 is an enlarged plan view showing the proximity state at the corner of FIG. FIG. 5 is a block diagram of the vehicle weight measurement system according to the embodiment of the present invention. FIG. 6 is a flowchart for explaining the operation of the indicator of FIG. FIG. 7 is a block diagram of a vehicle weight measurement system according to another embodiment of the present invention.

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

  FIG. 1 is a plan view showing an installation state of a track scale according to an embodiment of the present invention, and FIG. 2 is a side view thereof.

  The track scale 1 of this embodiment includes a platform 2 that is rectangular in plan view on which a vehicle enters and is mounted, and four digital load cells 3 that respectively support the four corners below the platform 2. A pit type track scale incorporated in a concrete pit 4 formed by digging down the ground surface 21.

  The concrete pit 4 is formed by digging the ground surface 21 so that the top surface of the platform 2 is at the same height as the ground surface 21, and each digital load cell is placed between the steel platform 2 and the pit 4. 3 are installed. A required gap is secured between the outer surface 2a which is the outer peripheral portion of the mounting table 2 and the inner wall 4a of the pit 4 so as not to come into contact with the normal shaking movement of the mounting table 2.

  In this embodiment, in order to prevent an erroneous measurement of the vehicle weight, when the outer surface 2a of the mounting table 2 comes close to the inner wall 4a of the pit 4 up to a set distance, it is detected and notified. Yes.

  For this reason, a plurality of, in this embodiment, eight detection switches, each detecting that the outer surface 2a of the rectangular platform 2 in plan view is close to the inner wall 4a of the rectangular pit 4 in plan view. 5 are provided in the vicinity of the corners at both ends of each side of the rectangle.

  Each detection switch 5 includes a conductive retracting member 6 serving as a mounting-side contact, which is housed in an insulating resin case 20 attached to the outer surface 2 a of the mounting table 2 so as to be freely retractable. And a conductive plate 7 as a pit-side contact provided on the inner wall 4a. Each detection switch 5 outputs an on / off detection output depending on whether or not the outer surface 2a of the mounting base 2 where the detection switch 5 is installed is close to the inner wall 4a of the pit 4 up to a set distance. give.

  Each extending / retracting member 6 is urged and housed in the case 20 via a spring (not shown) so that a hemispherical contact portion protrudes from the outer surface 2a of the mounting table 2. The part can be retracted into the case 20 when pressed.

  The protruding amount of the retracting member 6 from the outer surface 2 a of the mounting table 2 corresponds to a set distance for detecting that the outer surface 2 a of the mounting table 2 is close to the inner wall 4 a of the pit 4. Therefore, the set distance can be set by this protrusion amount. This set distance is preferably a distance that hinders accurate weighing. For example, the set distance may be a distance immediately before the outer surface 2a of the mounting table 2 contacts the inner wall 4a of the pit 4, or the mounting table. The outer side surface 2a of the pit 2 may be close to the inner wall 4a of the pit 4 and may be a distance to which a lateral load is exerted that adversely affects the digital load cell 3. Alternatively, it may be a distance immediately before the lateral load is applied.

  In this embodiment, the outer surface 2a of the mounting table 2 is close to the inner wall 4a of the pit 4 and immediately before a lateral load that adversely affects the digital load cell 3 is applied.

  Each conductive plate 7 is installed on the inner wall 4a of the pit 4 so as to face each of the retracting members 6 respectively.

  Since the detection switch 5 is provided so as to correspond to each side of the rectangle, the position of the platform 2 due to the swinging motion of the platform 2 in the front-rear direction (the left-right direction in FIGS. 1 and 2), which is the approach direction of the vehicle. The platform 2 can detect the proximity of the outer side surface 2a to the pit inner wall 4a, and is caused by the swinging motion of the platform 2 in the left-right direction (vertical direction in FIGS. 1 and 2) that is a direction orthogonal to the approach direction. The proximity of the outer surface 2a to the pit inner wall 4a can be detected.

  Further, since the detection switch 5 is provided in the vicinity of the corner of the rectangle, the proximity of the outer surface 2a of the mounting table 2 to the pit inner wall 4a due to the swinging motion of the mounting table 2 in an oblique direction other than the front / rear / left / right direction. Can be detected.

  Each pair of detection switches 5 at each corner is connected to each digital load cell 3 provided at each corner by a wiring (not shown), and is supplied with power from each digital load cell 3 and outputs a detection output. Each digital load cell 3 is given.

  As shown in the plan view of FIG. 3, necessary gaps are formed between the outer surface 2 a of the platform 2 and the inner wall 4 a of the pit 4 in the normal state, as shown in the plan view of FIG. 3. Has been. In this state, each extension / retraction member 6 of the mounting table 2 is not in contact with the conductive plate 7 on the inner wall 4a of the pit 4, and the detection output of each detection switch 5 is turned off. In this state, it is possible to accurately measure the weight of the vehicle.

  On the other hand, for example, as shown in the plan view of FIG. 4, the platform 2 moves in an oblique direction due to, for example, secular change or an impact caused by a sudden boarding of the vehicle on the platform 2. When the outer peripheral portion 2a comes close to the inner wall 4a of the pit 4 beyond a set distance, the retracting member 6 of the mounting table 2 comes into contact with and contacts the conductive plate 7 of the inner wall 4a of the pit 4 and the corresponding detection. The detection output of the switch 5 is turned on. Thereby, it is possible to detect that the outer surface 2a of the mounting table 2 is close to the inner wall 4a of the pit 4 up to a set distance.

  FIG. 5 is a block diagram of a vehicle weight measuring system provided with the above-described track scale 1, and parts corresponding to those in FIG.

  The vehicle weight measuring system of this embodiment includes the above-described track scale 1 and an indicator 8 as a weighing device connected to the track scale 1.

  The configuration of the four digital load cells 3 that respectively support the lower four corners of the mounting table 2 is common, and each digital load cell 3 has an analog load cell 9 and an analog load signal of the analog load cell 9 as A / A / D converter 10 that performs D conversion, A / D converters 11 and 12 that perform A / D conversion on the outputs of each of the pair of detection switches 5 at each corner described above, and the digital of A / D converter 10 A microcomputer 13 for calculating the weight based on the load signal and a communication unit 14 for serial communication with the indicator 8 and other digital load cells 3 via the common line 15 are provided. Each digital load cell 3 A / D-converts the detection outputs of the pair of detection switches 5 by the A / D converters 11 and 12, respectively, and supplies the signals to the indicator 8 through individual signal lines.

  Power is supplied to each digital load cell 3 via a power line (not shown) from the indicator 8, and further, power is supplied from each digital load cell 3 to a pair of detection switches 5 connected to the digital load cell 3.

  The analog load cell 9 includes a strain body and a plurality of strain gauges provided on the strain body, and the strain gauges constitute a bridge circuit. The analog load cell 9 outputs an analog load signal corresponding to the applied load from the bridge circuit.

  The indicator 8 has a communication unit 16 for serial communication with each digital load cell 3, calculation of the weight of the vehicle, etc., a microcomputer 17 for controlling each unit, and operation keys for performing various setting inputs. An operation input unit 18 and a display unit 19 that displays a measurement value and displays when proximity is detected by each detection switch 5 are provided.

  This indicator 8 calculates the weight value of the vehicle by summing the measured values from the respective digital load cells 3, and based on the on / off detection signals from the respective detection switches 5, the outer surface 2a of the mounting table 2 is Then, it is determined whether or not the user has approached the inner wall 4a of the pit 4 up to a set distance.

  FIG. 6 is a flowchart for explaining the operation of the indicator 8 of this embodiment.

When the vehicle enters the platform 2 of the truck scale 1 and the weighing operation starts,
It is determined whether any of the detection switches 5 is ON (step S1). When any of the detection switches 5 is ON, it is determined whether the ON state has continued for a predetermined period (step S1). S2) When continuing for a predetermined period, it is determined that the outer surface 2a of the mounting base 2 is close to the inner wall 4a of the pit 4 up to a set distance, a warning is displayed on the display unit 19 (step S3), and the process ends. In this warning display, the detection switch 5 that is turned on, that is, a display that specifies a close location is also performed.

In step S1, when none of the detection switches 5 is ON,
It is determined whether or not a stable period necessary for performing stable measurement has elapsed (step S4). When the stable period has elapsed, based on the digital output of each digital load cell 3, the vehicle on the platform 2 is A measurement process for calculating the weight is performed, and the process ends (step S5).

  As described above, when the detection switch 5 is turned on when the outer surface 2a of the mounting table 2 comes close to the inner wall 4a of the pit 4 to the set distance, the fact is displayed and notified on the indicator 8, so that the user Can grasp that there is a possibility that the outer surface 2a of the platform 2 may not be able to perform normal measurement close to the inner wall 4a of the pit 4 up to a set distance, thereby performing track scale maintenance, etc. Appropriate measures can be taken.

  In this embodiment, the set distance is set to a distance immediately before the lateral load is exerted on the digital load cell 3 so that the outer surface 2a of the mounting table 2 is close to the inner wall 4a of the pit 4 as described above. In addition, for example, the distance immediately before the outer surface 2a of the mounting table 2 contacts the inner wall 4a of the pit 4 may be set, or the outer surface 2a of the mounting table 2 may be in close proximity to the inner wall 4a of the pit 4 It is good also as the distance which a lateral load which has a bad influence on the load cell 3 applies. Alternatively, this set distance may be set to “0” and it may be detected that the outer surface 2 a of the mounting table 2 contacts the inner wall 4 a of the pit 4.

  In this embodiment, the number of digital load cells 3 is four. However, the number of digital load cells 3 is arbitrary, and may be six or eight, for example.

  Further, the number of detection switches 5 is not limited to eight, and is arbitrary, for example, ten.

  In the above-described embodiment, the digital load cell 3 is used. However, the present invention is not limited to the digital load cell 3, and for example, an analog load cell 9 may be used as shown in FIG.

  In this case, the analog load signals of the four analog load cells 9 and the detection outputs of the pair of detection switches 5 corresponding to the analog load cells 9 are sent to the microcomputer via the A / D converters 10a to 12a of the indicator 8a. 17a is input to calculate the weight of the vehicle and to detect the proximity of the outer surface 2a of the platform 2 to the inner wall 4a of the pit 4.

  In each of the above-described embodiments, contact or proximity of the outer surface 2a of the platform 2 to the pit inner wall 4a is detected by contact of a contact point. However, as another embodiment of the present invention, for example, a non-contact such as a proximity switch is used. You may make it detect the contact or proximity | contact with the pit inner wall 4a of the outer peripheral surface 2a of the mounting base 2 using a contact switch.

  Some track scales have a stopper that restricts the outer surface of the platform from approaching the inner wall of the pit so that a lateral load that adversely affects the load cell is not applied. The stopper may be used also as the above-described detection switch. Of course, the above-described detection switch may be provided separately from the stopper.

  The present invention is useful for measuring the weight of a vehicle such as a truck.

DESCRIPTION OF SYMBOLS 1 Track scale 2 Mounting stage 3 Digital load cell 4 Pit 5 Detection switch 6 Ejection member 7 Conductive plate 8 Indicator 9 Analog load cell 10-12 A / D converter 13, 17 Microcomputer 14,16 Communication part

Claims (4)

A platform on which a vehicle is placed and a plurality of load cells that support the platform are track scales incorporated in a pit,
A detecting means for detecting that the outer peripheral portion of the table is in contact with the inner wall of the pit or approached a set distance;
Giving the detection output of the detection means to the notification means for notifying that the contact or the proximity.
A track scale characterized by that. The detection means includes a plurality of detection switches that turn on and off depending on whether or not the set distance has been approached,
Each detection switch has a platform-side contact installed on the outer periphery of the table, and a pit-side contact installed on the inner wall of the pit so as to face the platform-side contact, respectively.
The track scale according to claim 1. The aforementioned table and the pit are rectangular in plan view,
The plurality of detection switches are respectively installed in the vicinity of corners at both ends of each side of the rectangle.
The track scale according to claim 2. The track scale according to any one of claims 1 to 3, and a weighing device connected to the track scale,
The weighing device calculates the weight of the vehicle based on the outputs of the plurality of load cells, and the outer peripheral portion of the table contacts the inner wall of the pit based on the detection output of the detection means. Or inform you that you have approached the set distance,
A vehicle weight measuring system.

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