JPH0222781Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wheel information detection device for identifying the type of vehicle entering and exiting a toll road, toll parking lot, etc.

[Conventional technology]

With the development of toll roads and toll parking lots, in order to save labor and make toll collection operations safer, toll rates automatically identify the type of vehicle passing through the toll plaza and calculate and record the toll corresponding to that type of vehicle. The collection system is being studied.

There are two ways to identify vehicle types: one uses the shape and dimensions of the vehicle body, and the other uses information about the wheels. Among these methods, the latter method is advantageous in that it can be performed relatively easily, and among the latter methods, the method using the number of axles and the number of wheels as the determining factors is recommended as a relatively reliable method.

FIGS. 5a and 5b show such conventional sensor A for detecting the number of axles (FIG. 5a) and sensor B for detecting the number of wheels (FIG. 5b).
The axle number detection sensor A is as shown in Figure 5a.
A pressure sensitive conductive rubber plate _A3 is interposed between an upper electrode plate _A1 and a lower electrode plate _A2 . These three plates extend in a direction perpendicular to the plane of the paper and are installed across the path of the vehicle. The pressure-sensitive conductive rubber plate _A3 is normally not conductive, but becomes conductive due to the pressure when the wheel presses against the axle number detection sensor A, and the upper and lower electrode plates _A1 and _A2
The number of axles can be detected from the number of times the wheels pass.

The axle number detection sensor B is constructed by interposing a pressure-sensitive conductive rubber plate _B3 between an upper electrode plate _B1 and a lower resistor _B2 , as shown in FIG. 5b.
Similar to the axle number detection sensor A, these three plates extend long in the direction perpendicular to the plane of the paper and are provided so as to cross the vehicle path. A constant current is passed through the lower resistor _B2 , and when the wheel presses on this axle number detection sensor B, the pressure-sensitive conductive rubber plate _B3 corresponding to the width of the wheel is compressed and becomes conductive.
Therefore, in a region corresponding to the width of the wheel pressed by the wheel, the current flowing through the lower resistor _B2 flows to the upper electrode plate _B1 via the pressure-sensitive conductive rubber plate _B3 . At this time, when the potential difference between both ends of the lower resistor _B2 is measured, the value decreases in proportion to the wheel tread width, and the number of wheels can be detected using this wheel width.

By the way, in the above-mentioned axle number _detection sensor A _and axle number detection sensor _B , there _are The contact resistance with respect to the pressure-sensitive conductive rubber plate has a characteristic that as the contact resistance increases, the difference between the detected value and the theoretical value increases. For this reason, it is desirable to set the contact resistance in these sensors to be as small as possible.

However, in sensors using pressure-sensitive conductive rubber plates A ₃ and B ₃ like the detection sensors A and B described above, the relationship between pressing force (treading force) F and contact resistance R is as shown in FIG. The relationship is as shown by the R characteristic curve H, and the contact resistance when the wheel is pressed tends to become significantly large, especially when the wheel pressing force is small. Therefore, in the case of lightweight vehicles such as motorcycles, there is a problem that the difference between the detected value and the theoretical value becomes large, and the detection accuracy decreases.

[The problem that the idea aims to solve]

The purpose of the present invention is to connect the upper electrode plate A ₁ and the lower electrode plate A 2 that constitute the above-mentioned axle number detection sensor A, and between the upper electrode plate _{B 1 and} the resistor B ₂ that constitute the wheel number detection sensor B. An object of the present invention is to provide a vehicle wheel information detection device that enables highly accurate detection by reducing the contact resistance to a pressure-sensitive conductive rubber plate between the wheels, regardless of the magnitude of the treading force of the wheel.

[Means to solve the problem]

The wheel information detection device of the present invention that achieves the above object includes an axle number detection sensor 30 configured by interposing a pressure-sensitive conductive rubber plate 33 between an upper electrode plate 31 and a lower electrode plate 32, and an upper electrode plate 41. and an axle number detection sensor 40 configured by interposing a pressure-sensitive conductive rubber plate 43 between a resistor 42 at the lower part are respectively arranged on the vehicle traffic road so as to cross the traffic road, and the pressure-sensitive conductive This is characterized in that a large number of insulating protrusions T are provided on at least one side of each of the rubber plates 33 and 43, respectively.

The insulating protrusion T reduces the contact resistance of the pressure-sensitive conductive rubber plate with respect to the electrode plate or the resistor when it receives tread pressure, thereby enabling highly accurate detection.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to embodiments shown in the drawings.

FIG. 1 exemplifies a toll collection station of a toll road or a parking lot equipped with the wheel information detection device of the present invention. C is a tollgate, and a vehicle passageway G is provided in front of it. A wheel information detection device E of the present invention is installed on this traffic route G so as to cross the traffic route G.

FIG. 2 shows the main parts of the device of the present invention, and shows a space 10 with a rectangular cross section in a pressure receiving plate 10 buried in a traffic route.
a and 10b are provided in parallel so as to cross the traffic road. A space 10a is arranged in the center of this pressure receiving plate 10, and spaces 10b are arranged on both left and right sides of the space 10a, and the entire pressure receiving plate 10 is covered with an outer covering rubber 20. In addition, in these spaces 10a and 10b,
A long axle number detection sensor 30 and an elongated axle number detection sensor 40 are inserted, and an actuator 50 is arranged on their upper surfaces. This actuator 50 is made of an elastic member having an appropriate spring constant, and its lower end is in contact with each detection sensor, and its upper end is directed toward the treading part 21 of the outer rubber cover 20, about several mm from the upper surface of the pressure receiving plate 10. I try to stand out.

The axle number detection sensor 30 has an upper electrode plate 3, as illustrated in FIGS. 3a, b, and c, respectively.
A pressure-sensitive conductive rubber plate 33 is placed between 1 and the lower electrode plate 32.
It is constructed by intervening. Moreover, the pressure-sensitive conductive rubber plate 33 has a large number of insulating protrusions T provided at intervals on at least one side. In the example of FIG. 3a, the insulating protrusion T of the pressure-sensitive conductive rubber plate 33 is
It is provided only on the side surface, and in the example of Fig. 3b,
Insulating protrusions T are provided only on the surface on the lower electrode plate 32 side. In the example shown in FIG. 3c, insulating protrusions T are provided on both surfaces of the upper electrode plate 31 and the lower electrode plate 32.

In this way, the pressure-sensitive conductive rubber plate 33 constituting the axle number detection sensor 30 may be provided with an insulating protrusion T on at least one side, but from the viewpoint of durability against repeated compression, the pressure-sensitive conductive rubber plate 33 as shown in FIG. It is better to provide insulating protrusions T on both sides.

The wheel number detection sensor 40 also includes a pressure-sensitive conductive rubber plate 4 between an upper electrode plate 41 and a resistor 42, as illustrated in FIGS. 4a and 4b, respectively.
It is constructed by interposing 3. Moreover, the pressure-sensitive conductive rubber plate 43 has a large number of insulating protrusions T on at least one side.
are provided at intervals. In the example in Figure 4a,
The pressure-sensitive conductive rubber plate 43 is provided on only one side facing the resistor 42, and in the example shown in FIG. has been established.

In the case of this wheel number detection sensor 40, when the insulating protrusion T is provided on only one side of the pressure-sensitive conductive rubber plate 43, it cannot be arranged so that the insulating protrusion T faces the surface on the upper electrode plate 41 side. this is,
When no pressure is applied, the pressure-sensitive conductive rubber plate 43 and the resistor 4
This is because it is better not to make electrically conductive contact with 2. In the case of this wheel number detection sensor 40 as well, it is better to provide insulating protrusions T on both sides of the pressure-sensitive conductive rubber plate 43 from the viewpoint of durability against repeated compression.

In the above-mentioned axle number detection sensor 30 and wheel number detection sensor 40, by providing a large number of insulating protrusions on the pressure-sensitive conductive rubber plate, the magnitude of the pedal pressure on the wheels can be adjusted as shown by curve E in FIG. Regardless, the contact resistance R can be significantly reduced. Moreover, the contact resistance can be made almost uniform even with a small pedal pressure. Therefore, the contact resistance to the pressure-sensitive conductive rubber plate between the upper electrode plate and the lower electrode plate constituting the axle number detection sensor and between the upper electrode plate and the resistor constituting the wheel number detection sensor is calculated for each wheel. Even if the pedal pressure is small, it can be reduced, and the detection accuracy can be greatly improved even when detecting lightweight vehicles such as motorcycles.

In addition, since the insulation between the electrode plates or between the electrode plates and the resistor is mechanically performed using insulating protrusions provided on the surface of the pressure-sensitive conductive rubber plate, when the pressure-sensitive conductive rubber plates are in direct contact with each other, In comparison, insulation properties can be significantly improved. Therefore, in addition to reducing the contact resistance described above, detection accuracy can be significantly improved.

The insulating protrusions T provided on the surface of the pressure-sensitive conductive rubber plate of the present invention are preferably made of a rubber-like elastic material with excellent electrical insulation properties, such as silicone rubber. The height of the insulating protrusion T is preferably set to 30 to 100 μm, the diameter to 0.5 to 2 mm, and the pitch to 1 to 3 mm. More preferably, the height is 40 to 50 μm and the diameter is 1.5 to 2 mm. By setting the height of the insulating protrusion T to 100μ or less, the diameter to 2mm or more, and the pitch to 1mm or more, it is possible to connect the upper electrode plate 31 and the lower electrode plate 32 or the upper electrode plate 41 and the lower part with a smaller pressing force. This is because it can come into contact with the resistance plate 42 and become conductive. On the other hand, the height and diameter of the insulating protrusion T are
By setting the pitch to be 30 μ or more and 0.5 mm or more, respectively, and the pitch to be 3 mm or less, the area of the part where the insulating protrusion T is not present can be reduced, and the conductive parts of the pressure-sensitive conductive rubber plates 33 and 43 can be kept in a non-pressure state. It is possible to improve the insulation properties of the

[Effect of idea]

As described above, the device of the present invention includes a pressure-sensitive conductive rubber plate provided between the upper electrode plate and the lower electrode plate of the axle number detection sensor, and a pressure-sensitive conductive rubber plate provided between the upper electrode plate and the resistor of the wheel number detection sensor. By providing a large number of insulating protrusions on at least one side of each pressure-sensitive conductive rubber plate, the contact resistance to the working electrode plate and resistor can be reduced and made almost uniform regardless of the magnitude of the tread pressure. Can be done. Therefore, even lightweight vehicles such as motorcycles can be detected with high accuracy.

[Brief explanation of the drawing]

1 to 4 show embodiments of the present invention, FIG. 1 is a perspective explanatory view showing an example in which the wheel information detection device of the present invention is installed at a toll gate of a toll road, and FIG. - Fig. 3 a, b and c are enlarged explanatory views showing an example of the axle number detection sensor used in the wheel information detection device of the present invention, and Fig. 4 a and b are respectively An enlarged explanatory diagram showing an example of a wheel number detection sensor used in the wheel information detection device of the invention, FIGS. FIG. 6 is an enlarged explanatory diagram showing the number detection sensor (Figure a), and a diagram showing the relationship between the pressing force F and the contact resistance R. 10...Pressure plate, 10a, 10b...Space, 2
0... Outer rubber, 21... Elastic treading part, 30...
Axle number detection sensor, 40... Wheel number detection sensor, 31, 41... Upper electrode plate, 32... Lower electrode plate, 42... Lower resistor, 33, 43... Pressure-sensitive conductive rubber plate, T... ...Insulating protrusion, G...road.

Claims (1)

[Scope of utility model registration request] The axle number detection sensor 30 includes a pressure-sensitive conductive rubber plate 33 interposed between an upper electrode plate 31 and a lower electrode plate 32, and a pressure-sensitive conductive rubber plate between the upper electrode plate 41 and the lower resistor 42. A wheel number detection sensor 40 configured by interposing a wheel number sensor 43 is arranged on the vehicle traffic road so as to cross the traffic road,
A vehicle wheel information detection device in which a large number of insulating protrusions T are provided on at least one side of each of the pressure-sensitive conductive rubber plates 33 and 43.