JP5579114B2 - Vehicle axle weight measuring device - Google Patents

Description

  The present invention relates to a vehicle axle load measuring device used in an automatic toll collection system on a toll road.

  In recent years, ETC (Electronic Toll Collection System) has been introduced as a system for automating toll collection at toll gates such as toll roads and parking lots. This toll collection method by ETC obtains vehicle specific information of the vehicle by performing wireless communication between the IC card set in the vehicle-mounted device mounted on the vehicle and the antenna of the toll collection system installed at the toll gate The toll is collected.

  In the toll collection passage in the toll collection system, a tread for detecting entry of a vehicle is provided (for example, see Patent Document 1). This tread board is embedded in the passage, and detects the pressing of the vehicle when a contact body provided therein is short-circuited to the vehicle by weight. A pressing signal indicating the presence or absence of pressing is output to a lane server of the toll collection system, and the lane server performs vehicle entry detection and forward / backward detection based on the pressing signal.

In addition, a tread board that can detect a distance (tread) between left and right wheels in a vehicle is also known (see, for example, Patent Document 2).
Information based on the pressure of the vehicle detected by such a tread (hereinafter referred to as tread detection information) is linked to the vehicle specifying information acquired by the antenna by the lane server, and is used for smooth operation of the toll road. ing.

On the other hand, an axle weight meter is provided in front of the toll gate on the toll road separately from the toll collection system (see, for example, Patent Document 3). This axle weight meter measures the axle weight of a passing vehicle and determines the possibility of overloading for the purpose of road maintenance and the like.
Also known is a tread that can detect the axle weight of a vehicle by an axle weight detector such as a strain gauge and obtain tread detection information such as the number of axles of the vehicle, tread, and forward / reverse based on the detected axle weight information. (See, for example, Patent Document 4).

Japanese Patent No. 2941650 JP-A 61-166688 JP 2008-039489 A Japanese Patent Application Laid-Open No. 07-225891

  However, since the tread described in Patent Document 4 is configured to calculate the axle load based on a signal detected after a certain period of time, the axle load detector is shifted in the front-rear direction. The construction differs greatly from that of the tread, and there is a problem that it takes time and cost to replace the conventional tread.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an axle load measuring device that can be constructed without greatly changing the configuration of a conventional tread.

In order to achieve the above object, the present invention provides the following means.
A vehicle axle weight measuring device according to the present invention is provided on a traffic path of a vehicle, and is supported by the tread frame and the tread frame, and opens and closes by passing the wheels of the vehicle along the traffic path. A tread board constituted by a tread board body having a built-in switch, and a flange portion that is provided so as to extend from the tread frame, and that is independently displaced with respect to the tread frame by receiving a load of a wheel of the vehicle ; A pressure transducer that is arranged below the flange portion and applies pressure to the fluid by displacement of the flange portion , a sensor that detects the pressure of the fluid, and an operation that calculates the axle load of the vehicle from the output of the sensor possess a section, along the traffic route, a plurality of switches for opening and closing the passage of the wheel is provided, wherein the arithmetic unit, the cell by opening and closing timings of the plurality of switches And correcting the output of Sa and calculates the axle load of the vehicle.

  According to the above configuration, since the displacement of the tread frame that is a part of the conventional tread is detected and the axle load of the vehicle is calculated, the axle load measuring device can be constructed without significantly changing the conventional tread. . Further, by disposing the pressure transducer outside the tread, it is possible to interlock with the tread, and it is possible to cope with the complex behavior of the vehicle.

  According to the above configuration, the control unit can prevent erroneous detection of the axle load of the vehicle by referring to the opening / closing timings of the plurality of switches.

  In addition, it is preferable that the arithmetic unit calculates the axial load from the output of the sensor only when a close signal is transmitted from all the switches in order from the frontmost switch toward the front of the vehicle.

  According to the above configuration, since the control unit determines the traveling direction of the vehicle with reference to the output order of the plurality of switches, the erroneous detection of the axle load of the vehicle is more reliably prevented.

  The pressure transducer is composed of a cylindrical cylinder body filled with the fluid and a piston connected to a piston rod, and the piston rod and the piston are pressed by displacement of the tread frame, It is preferable that the cylinder body presses the sensor when the piston applies pressure to the fluid to detect the pressure of the fluid.

  According to the above configuration, since there is no electrical member such as a sensor in the cylinder body or the like, it is possible to construct a vehicle axle load measuring device that is resistant to environmental conditions such as rainwater.

  Further, the tread is comprised of a tread body that is supported in the tread frame and contains the plurality of switches, and the tread frame, and a part of the tread frame is displaced independently. .

  According to the above configuration, since only a part of the tread frame is displaced, the reliability of the switch can be secured without affecting the operation of the switch when the axial load is measured. .

  According to the present invention, it is possible to construct an axle load measuring device that calculates axle load with a smaller configuration. Thereby, it is possible to install the axle load measuring device in the immediate vicinity of the existing tread.

It is the schematic which shows the vehicle axle load measuring apparatus of 1st embodiment of this invention. It is a top view of the vehicle axle load measuring device of a first embodiment of the present invention. It is AA sectional drawing of FIG. It is a graph of the signal transmitted to a control part. It is a graph of the signal transmitted to a control part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, a vehicle axle load measuring apparatus 1 according to the present embodiment includes a step board 2 provided on a vehicle passageway 50, and a vehicle separator 3 that is installed opposite to the passageway 50. The control unit 4 is connected to the tread board 2 and the vehicle separator 3.

Since the tread 2 is embedded in the road surface 52 below the optical axis of the vehicle separator 3 and is installed so as to straddle the passage 50 in the width direction, when the vehicle 51 passes through the passage 50, the front wheel of the vehicle 51 And the rear wheels sequentially pass over the vehicle axle load measuring device 1.
The vehicle separator 3 uses a light transmission type optical sensor, and transmits a vehicle detection signal while the vehicle 51 passes between the vehicle separators 3.

  As shown in FIGS. 2 and 3, the tread 2 includes a tread main body 5, a tread frame 6 that supports the tread main body 5, and a pressure cylinder 7 that outputs pressure when the vehicle 51 passes over the tread frame 6. Have Moreover, the arrow of FIG. 2 is the advancing direction (front) of the vehicle 51.

  The tread frame 6 is a rigid body made of iron, and is incorporated into a groove 53 formed in the road surface 52. The tread frame 6 has a U-shaped cross section with an opening on the top, and a main body 9 extending in the width direction of the passage 50, and a first flange 10 extending forward from the upper end of the main body 9. The second flange portion 11 extends rearward. Note that the forward direction is the traveling direction of the vehicle (upward in FIG. 2), and the backward direction is the opposite direction. The first flange portion 10 is divided and independent from the main body portion 9, and is configured to be displaced in the vertical direction under the load of the wheels of the vehicle 51.

  Inside the tread board main body 5, three elongated tread board contact bodies 13 are incorporated. The three tread plate contact bodies 13 are sensors that are installed at equal intervals along the passage of the vehicle 51 and are configured to open and close when the vehicle 51 passes. Hereinafter, the three tread board contact bodies 13 are referred to as a first tread board contact body 13a, a second tread board contact body 13b, and a third tread board contact body 13c in the order of travel.

  The pressure cylinder 7 includes a cylindrical cylinder body 18 and a piston 20 to which a piston rod 19 is connected. The cylinder body 18 is disposed below the first flange portion 10 and at the center in the left-right direction of the first flange portion 10 so that the axial direction is along the vertical direction. The piston 20 is incorporated in the cylinder body 18 so as to be reciprocally movable in the vertical direction, and the piston rod 19 is provided above the central portion of the piston 20 and extends to the outside of the cylinder body 18.

In the present embodiment, a pressure sensor 8 is provided in addition to the above configuration.
The pressure sensor 8 is provided outside the cylinder body 18 and detects the pressure in the detection space using the space 22 below the piston 20 as a detection space. For example, the pressure inserted in the space 22 The probe 23 can detect the pressure of the gas in the space 22. The pressure sensor 8 is installed in the housing of the control unit 4.
The pressure value in the space 22 detected by the pressure sensor 8 is output to the control unit 4. The pressure sensor 8 may be of any type as long as it can measure the atmospheric pressure in the space 22.

  The first flange portion 10 and the pressure cylinder 7 are arranged in series in the vertical direction in the order of the first flange portion 10 and the pressure cylinder 7 from above. The upper end of the piston rod 19 is abutted against the lower surface 10 a of the first flange portion 10. Therefore, when the first flange portion 10 is displaced in the vertical direction, the piston rod 19 and the piston 20 are pressed, and the piston 20 applies pressure to the space 22.

Next, the operation of the vehicle axle load measuring device 1 of this embodiment will be described.
When the tread plate 2 is stepped on while the vehicle 51 moves forward, the tread plate main body 5 and the first flange portion 10 are pressed. First, when the vehicle 51 passes over the tread body 5 of the tread 2, a closing signal is transmitted from the tread contact body 13. Specifically, the first tread board contact body 13a, the second tread board contact body 13b, and the third tread board contact body 13c sequentially transmit a closing signal to the control unit 4.

Further, when the vehicle 51 moves forward, the first flange portion 10 is pressed from above by the vehicle 51, and the piston 20 moves downward inside the cylinder body 18 via the piston rod 19. Next, the pressure rises as the space 22 below the piston 20 is compressed. Thereby, the pressure of the gas in the space 22 is measured by the pressure sensor 8 via the atmospheric pressure probe 23, and electric power corresponding to the load is transmitted to the control unit 4.
Further, a vehicle detection signal is transmitted to the control unit 4 by the vehicle separator 3.

The control unit 4 calculates the axle load of the vehicle 51 by correcting the output of the pressure sensor 8 according to the opening / closing timings of the plurality of tread board contact bodies 13. The process will be described below with reference to FIG.
As shown in FIG. 4A, when the large vehicle 54 travels normally, the vehicle separator 3, the tread plate contact body 13, and the pressure sensor 8 show the control unit 4 as shown in the graph of FIG. 4B. Is output. In this graph, the horizontal axis is time. The vertical axis represents ON / OFF of the vehicle separator 3 and the tread plate contact body 13 and the load of the pressure sensor 8.

The control unit 4 includes a first tread plate contact body 13a, a second tread plate contact body 13b, and a third tread board contact within a predetermined time, for example, within a time during which the vehicle 51 passes at a standard speed between the vehicle separators 3. It has a function of determining that the vehicle 51 has passed when a load signal is output from the pressure sensor 8 after the closing signal (ON) is output in the order of the body 13c. That is, within a predetermined time, a closing signal is transmitted from all the tread plate contact bodies 13 in order toward the front of the vehicle 51 from the front tread contact body 13a to the vehicle 51 entering the vehicle axle load measuring device 1. Only when the load output of the pressure sensor 8 is an effective input, the axle load is calculated.
Therefore, by detecting the output as shown in FIG. 4B, it is determined that the vehicle 51 has passed, and the axle load of the vehicle is calculated from the output of the pressure sensor 8. When it is determined that the vehicle 51, the maximum value of the load signal is adopted as the load F.

Further, the control unit 4 has a function of selecting whether the vehicle is a vehicle according to the input signal.
As shown in FIG. 5A, when only the front wheel of the large vehicle 54 once enters the vehicle axle load measuring device 1 and moves backward, the control unit 4 includes the vehicle separator 3, the tread plate contact body 13, and the pressure sensor 8. In contrast, a signal as shown in the graph of FIG.
The control unit 4 detects the forward movement by outputting a closing signal (ON) in the order of the first tread plate contact body 13a, the second tread plate contact body 13b, and the third tread plate contact body 13c. A reverse signal (ON) is output in the order of the three-step board contact body 13c, the second tread board contact body 13b, and the first tread board contact body 13a, thereby detecting the reverse of the vehicle 51. As a result, it is determined that the target vehicle has not entered, and the vehicle measurement is cancelled.

  Further, the vehicle axle load measuring device 1 has a function of measuring the number of axes of the vehicle 51 used in the automatic toll collection system, like a conventional tread. The function of measuring the number of axes of the vehicle 51 is a function of measuring the number of axes of the vehicle 51. The function of measuring the number of axes of the vehicle 51 is measured based on the magnitude and timing of the load input measured by the method described above. For example, it is used for discrimination of the vehicle type of the vehicle 51.

  According to the above embodiment, the axle load measuring device 1 is constructed without greatly changing the conventional tread because the displacement of the tread frame 6 that is a part of the conventional tread is detected and the axle weight of the vehicle 51 is calculated. can do. Further, by disposing the pressure cylinder 7 inside the tread board 2 (frame portion), it is possible to interlock with the tread board 2 and to cope with complicated behavior of the vehicle.

  Further, the control unit 4 can prevent erroneous detection of the axle load of the vehicle 51 by referring to the opening / closing timings of the plurality of tread board contact bodies 13. Furthermore, since the control unit 4 refers to the output order of the plurality of tread plate contact bodies 13 to determine the traveling direction of the vehicle 51, it is possible to more reliably prevent erroneous detection of the axle load of the vehicle 51.

Further, since there is no electric member such as a sensor in the cylinder body 18 or the like constituting the pressure cylinder 7, the vehicle axle load measuring device 1 that is resistant to environmental conditions such as rainwater can be constructed.
Further, since only the first flange portion 10 that is a part of the tread frame 6 is displaced, the tread plate contact is not affected by the displacement of the tread frame 6 during the axial load measurement. The reliability of the body 13 can be ensured.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, as an alternative to the pressure cylinder 7 using a compressible fluid (gas), a hydraulic cylinder filled with an incompressible fluid (liquid) such as antifreeze or gel may be used. By using the antifreeze liquid, the vehicle axle load measuring device can be operated even in an environment where it is expected to freeze in winter, such as a snowy area. Further, by using a semi-solid material such as a gel, it is possible to improve ease of handling such as a liquid leakage prevention effect and an evaporation prevention effect.

  Further, the number of the tread board contact bodies 13 is not limited to three in the traveling direction, and may be four or more. When the number is four or more, since load data can be collected in more detail, the accuracy of the axial load can be improved.

DESCRIPTION OF SYMBOLS 1 ... Vehicle axial weight measuring apparatus, 2 ... Tread board, 4 ... Control part (calculation part), 5 ... Tread body, 6 ... Tread frame, 7 ... Pressure cylinder (pressure converter), 8 ... Pressure sensor (sensor), 10 DESCRIPTION OF SYMBOLS 1st flange part, 13 ... Tread board contact body (switch), 18 ... Cylinder body, 19 ... Piston rod, 20 ... Piston, 22 ... Air (fluid), 50 ... Passage route, 51 ... Vehicle.

Claims (3)

Provided on the traffic route of the vehicle ,
A tread frame,
A tread body that includes a plurality of switches that are supported in the tread frame and that open and close by the passage of wheels of the vehicle along the passage;
A flange portion that is provided so as to extend from the tread frame and that is displaced independently of the tread frame by receiving a load of a wheel of the vehicle;
A tread composed of
A pressure transducer that is disposed below the flange portion and applies pressure to the fluid by displacement of the flange portion ;
A sensor for detecting the pressure of the fluid;
Possess an arithmetic unit for calculating the axle weight of the vehicle from the output of said sensor,
A plurality of switches that open and close by the passage of the wheels along the traffic route are provided
Vehicle axle load measuring device, characterized in that said. The arithmetic unit is the most than before the switch toward the vehicle front from the turn all switches when the close signal originated only, according to claim 1, characterized in that calculating the axle load from the output of the sensor Vehicle axle weight measuring device. The pressure transducer is composed of a cylindrical cylinder body filled with the fluid, and a piston connected to a piston rod,
The piston rod and the piston are pressed by displacement of the tread frame, and when the piston applies pressure to the fluid, the cylinder body presses the sensor and detects the pressure of the fluid. The vehicle axle load measuring device according to claim 1 or 2 .

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