JPS59204724A - Axle load gage - Google Patents

Abstract

PURPOSE:To make the operation simple and convenient and to ensure measuring accuracy and reliability, by detecting the axle load based on the pressure of a non-compressive fluid when a pressure receiving plate is compressed by a wheel. CONSTITUTION:A pressure receiving plate 22 has a strength, which can sufficiently withstand the axle load W of a wheel 1. The plate 22 is supported by an edge part 24 of an elastic rubber body 21, which is reinforced by cord 23. Since the pressure receiving plate 22 is flexibly supported by the edge part 24, the axle load W balances with the pressure P of a non-compressive fluid in a space 26. The pressure P is converted into an electric signal by a pressure head 30. The signal is displayed on a display part 32 as a load through an amplifier 31. As the non-compressive fluid, water, oil, a semi-solid state material in a grease state, or high viscosity liquid is used.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention relates to an axle load meter for measuring the load exerted on a road surface by the wheels of a vehicle, particularly an automobile, that is, the axle load. For example, for the purpose of inspecting whether a luggage vehicle is loaded with cargo that exceeds the load limit, or statistically processing the axle loads of vehicles passing on the road to use as data for road maintenance management. used.

[Prior art and its problems]

Conventionally, this type of axle load meter has been installed, for example, at expressway toll booths and used to check whether excessive loads are being loaded.An example of this is shown in Figure 1. In this axle load meter, the axle load applied to the wheels 1 of the vehicle is transmitted to the load cell 5 via the pressure receiving plate 2,
It is extracted as a change in electrical resistance. One end of the pressure receiving plate 2 is rotatably supported by a frame 4 via a hinge 3. The frame 4 itself is attached by anchor bolts 6 in pits 8 provided in a road surface 7. The electrical signal from the load cell 5 is amplified by the strain amplifier IO via the cable 9, and is sent to the indicator 11, for example.
．． It is converted into a load such as 5 tons and displayed as a scientific value.

However, the axle load meter has a pit 8 for installing the load cell 5, and the frame 4 is installed in the pit. Anchor bolt 6 for fixing
The problem is that it requires a lot of cost for civil engineering work. Furthermore, the pressure plate 2, frame 4, and hinge 3 of this axle load meter must be constructed as mechanical structural parts with high rigidity that can withstand a predetermined load, which also makes them expensive. Load cell 5 is also expensive. In other words, the disadvantage of the axle load meter shown in FIG. 1 is that the total cost is high.

The axle load meter of FIG. 2, which does not require a pit, is also known.

The axle load meter has a main body 12, which is made of a rubber-like elastic material and has a cylindrical shape as a whole, and is placed on a road surface 7.

An intermediate electrode 14 is disposed inside the main body 12 so as to be parallel to the road surface 7, and a spring section 13 is disposed above and below the intermediate electrode 14. An electrode 15 or a lower electrode 16 are provided. Both the upper and lower electrodes 15 and 16 are electrically interconnected and the capacitance between them and the intermediate electrode 14 is measured. In this axle load meter, when the wheel 1 presses the main body 12, the spring portion 13 deforms, thereby changing the distance between the electrodes and changing the above-mentioned capacitance. This is guided to the outside via a cable 18, and is indicated as a load measurement value by an indicator 20 via a conversion amplifier 19.

This shaft revision can be constructed to be small and lightweight, easy to handle, and has the advantage that it does not require major construction work such as pits on the road surface. However, this axle load meter has the disadvantage that it is inferior to other types of axle load meters in terms of measurement accuracy and reliability. The principle of the conversion of axle load to capacitance, which forms the principle of an axle load meter, is that it depends on the spring characteristics of the spring section 13. In other words, the equation between the axle load and the deflection of the spring section 13 is However, it is extremely difficult to make the relationship between the two in direct proportion so that the relationship is linear, and normally the displacement of the spring part increases as the load, that is, the axle load increases. The spring part 13 has a non-linear characteristic in which the amount of increase gradually decreases. Also, the spring part 13 has a hysteresis characteristic between the υ load and the displacement due to internal loss, and the load changes when the load increases and when the load decreases. The amount of displacement is 1
There is a tendency that they do not correspond in a one-to-one relationship. Further, the rubber-like elastic body constituting the main body 12 has a characteristic that its properties, particularly hardness, degree of internal loss, etc., vary significantly depending on temperature.

For these reasons, although the axle load meter shown in Figure 2 has the great advantage of being easy to handle, its practical use is extremely limited in terms of measurement accuracy and reliability. It was.

[Purpose of the invention]

The present invention was made in consideration of such circumstances, and
The object of the present invention is to provide an axle load meter that is easy to handle and at the same time can guarantee measurement accuracy and reliability.

[Key points of the invention]

In order to achieve the above object, the present invention converts the axle load into liquid pressure proportional to it, and measures the pressure to determine the axle load. By supporting the peripheral edge of the pressure plate, which can be regarded as a rigid body, by a flexible rubber-like elastic body whose rigidity can be virtually ignored, a sealed space is formed below the pressure plate, and a non-compressible space is formed within this space. The axle load is detected from the pressure of the incompressible fluid when the pressure receiving plate is pressed by the wheels.

[Embodiments of the invention]

FIG. 3 shows an embodiment of the present invention.

This axle load meter is large enough to accommodate one wheel of at least one axle, and the axle load W of wheel 1 (strictly speaking, axle load is the total weight on both wheels of one axle). The pressure-receiving plate 2 has sufficient strength or rigidity to withstand the load (in this case, the load on one wheel is also referred to as the axle load).
2 is prepared, and the pressure receiving plate 22 has its peripheral edge made of a cord, for example, so that it is flexible against displacement in the thickness direction but has great rigidity against displacement in the plane direction. It is supported by the edge part of the rubber-like elastic body 21 reinforced by 23. The rubber-like elastic body 21 is formed in the shape of a container with the pressure-receiving plate 22 open, and has a bottom portion 5 substantially parallel to the pressure-receiving plate 22 . The pressure receiving plate 22 and the edge portion are liquid-tightly joined to form a sealed space 26 inside.

This space 26 is filled with an incompressible fluid such as water or oil. A plurality of axle load gauges (usually two) configured in this manner are provided in the axial direction of the wheel as necessary as units for receiving pressure of the axle load. A pressure guiding pipe 29 is led out from the space 26 of each axle load meter and led to the pressure head 3o.

The pressure is converted into an electrical signal by the pressure rad 30, and the pressure measurement value is instructed to the indicating section 32 via the amplifier 31.

This axle load meter is disposed, for example, on the road surface 7, and when the axle load W caused by the wheels 21 is applied to the pressure receiving plate 22, since the pressure receiving plate 22 is flexibly supported by the edge portion, the axle load W will balance the pressure P of the incompressible fluid within the space 26. At this time, if the effective pressure-receiving area of the pressure-receiving plate 22 is S, then P=W/S. This is obvious when considering that the pressure receiving plate 22 acts as a piston having a constant area S. As mentioned above, this pressure P is converted into an electrical signal by the pressure head 30 and displayed as a load, such as 1.5 ton, on the indicator 32 via the amplifier 31.

FIG. 4 shows the state in which the wheel 1 starts or finishes applying pressure when the axle load meter configured as shown in FIG. 3 is placed on a road surface 7 that has not been specially treated for installation. be. In such a transient state, the axle load does not act evenly on the pressure receiving plate 22, but acts concentratedly on the ends thereof. Excessive displacement of the edge portion 24 in such a case adversely affects the service life and other aspects. Therefore, in this embodiment, the edge portion 24 is flange-shaped from the side wall portion and extends approximately parallel to the bottom portion 5 with a slight gap between the edge portion 24 and the bottom portion 5. This serves to prevent excessive displacement of the edge portion 24. In such a transient state, a part of the axle load W is supported by the overhanging part 4 that is in contact with the bottom part 5, so a pressure P proportional to the axle load W is not generated. An accurate axle load can be measured by measuring the value of the pressure P when the wheel 1 is passing, that is, the value of the maximum pressure P during the passage of the wheel 1. Figure 5 shows another embodiment of the present invention. 0 In this embodiment, the displacement of the pressure receiving plate 36 is oscillating, and one side of the pressure receiving plate 36 is not substantially displaced in the vertical direction, but the rotation support portion 37 swings the opposite side. The other side is configured as an edge portion 38 that allows displacement in the vertical direction, similar to the one shown in FIG. The area 43 on which the rotation support part 37 of the pressure receiving plate 36 is placed is filled with a rubber-like elastic body up to the bottom area, and is configured so as not to undergo slight compression deformation even when subjected to an axle load.

On the other hand, there is a space 4 in the lower region of the left end of the pressure receiving plate 36.
2 is formed, and therefore, when the pressure receiving plate 36 receives an axle load, the left end side is displaced as shown by the chain line. is lower than in the case of FIG. 3, but since a proportional relationship is maintained between the axle load W and the pressure P at a certain position of the pressure receiving plate 36, there is no problem in measurement.

Since one end of the pressure receiving plate 36 of this structure is supported by the rotation support portion 37, the pressure receiving plate 36 is difficult to deform, and the plate thickness can be made thinner than that of the embodiment shown in FIG. Therefore, it is possible to significantly reduce the difference in level when installing on a road surface.

FIG. 6 shows an embodiment which is basically the same as that shown in FIG. 3, but the bottom section in FIG. This shows that. This embodiment is an advantageous structure when fixing the axle load meter to the road surface 7 with bolts 40 or the like.

Figure 7 shows an attempt to install a load cell in a pit 41 provided on the road surface 7, eliminate the level difference between the load cell and the road surface, prevent the influence of fluctuating loads due to such a level difference, and perform highly accurate measurements. The structure is suitable for cases where

In each of the embodiments described above, water, oil, or a liquid containing these as the main components is generally used as the incompressible fluid, but a semi-solid substance like grease or a high viscosity liquid can also be used. By using the material, it is possible to increase the damping capacity during operation, reduce the fluctuations in the measured values due to fluctuating loads, and stabilize the measured values.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide an excellent axle load meter that is small and lightweight, easy to handle, and has a simple structure, while at the same time guaranteeing high measurement accuracy and reliability. can do 0

[Brief explanation of the drawing]

Figures 1 and 2 are sectional views of different conventional axle load meters, Figure 3 is a perspective view showing a part of an embodiment of the present invention in cross section, and Figure 4 is the state of the same embodiment during transition. 5, 6, and 7 are cross-sectional views showing different embodiments of the present invention. DESCRIPTION OF SYMBOLS 1... Wheel, 7... Road surface, 21... Rubber-like elastic substance, 22, 36... Pressure receiving plate, U... Edge part, 5
...Bottom part, 26... Sealed space, 38... Edge part, 39... Base plate. Patent applicant: Fuji Electric Manufacturing Co., Ltd.

Claims (1)

[Scope of Claims] l) A pressure receiving plate that has a sufficient width for a wheel to be placed on it and that maintains its rigidity in a practical and qualitative manner against the axle load applied through the wheel;
a bottom part provided almost parallel to the pressure receiving plate with a predetermined gap therebetween; and a bottom part provided on the bottom part, which supports the pressure receiving plate at its peripheral edge, being flexible in the thickness direction and not displacing in the plate surface direction. A sealed space is formed by supporting the rubber-like elastic body, and this sealed space is filled with incompressible fluid, and the pressure of the incompressible fluid is measured when the pressure receiving plate is pressed by the wheel. An axle load meter that is particularly characterized by determining the axle load. 2. In the axle load meter as set forth in claim 1, the portion of the rubber-like elastic body that supports the pressure receiving plate is formed in a flange shape from the side wall portion to the bottom portion with a slight gap between the portion and the bottom portion. An axle load meter that extends in parallel and is characterized in that this projecting part acts as a stopper that comes into contact with the bottom part when an excessive load is applied. 3) The axle load meter according to claim 1 or 2, wherein the rubber-like elastic body is reinforced with a reinforcing cord. 4) The axle load meter according to any one of claims 1 to 3, characterized in that the bottom portion is made integrally with a rubber-like elastic body.05) The wheel is a pressure-receiving plate that has a sufficient area to be placed on and maintains substantially rigidity against the axle load applied through the wheels; and a bottom portion provided approximately parallel to the pressure-receiving plate with a predetermined gap between the , is provided on the bottom part, and one side of the pressure receiving plate is not substantially displaced in the thickness direction and the plate surface direction, but when the opposite side of the pressure receiving plate opposite to the - side swings in the thickness direction. A sealed space is formed by a rubber-like elastic body that supports the peripheral edge of the pressure plate so as to be the center of rotation, and this sealed space is filled with incompressible fluid. The axle load meter according to claim 5, characterized in that the axle load meter is characterized in that the axle load is determined by measuring the pressure of an incompressible fluid when the rubber-like elastic The part of the body that supports the pressure plate protrudes almost parallel to the bottom part with a small gap between the side wall part and the bottom part in the form of a flange. 7) In the axle load meter according to claim 5 or 6, the rubber-like elastic body is reinforced with a reinforcing cord. Features an axle load meter. 8) The axle load meter according to any one of claims 5 to 7, characterized in that the bottom portion is made integrally with a rubber-like elastic body.