JP5730135B2 - Track scale - Google Patents

Description

  The present invention relates to a track scale. In particular, the present invention relates to a truck scale capable of guiding the wheel load and the center of gravity position of a vehicle such as a truck or trailer loaded with luggage.

  It is well known that when a vehicle such as a truck or a trailer carries a load, the traveling state may become unstable depending on the loaded state. In particular, during running on a curved road in which centrifugal force acts on the vehicle, the instability of the vehicle increases, and the main mechanical factors include the total weight, axle weight, wheel weight, and center of gravity of the vehicle. it can. In the vehicle restriction ordinance, the axle load is defined as 10 tons or less and the wheel load is defined as 5 tons or less.

  The deviation of the center of gravity from the center of the vehicle is called “single load”, if the center of gravity is at the front of the vehicle, it is called “front load”, if it is at the rear, it is called “back load”, etc. It is said that this is a loading state quantity that should be noted. An amount closely related to such a loaded state amount is the wheel load of the vehicle, and an amount serving as a basis for quantitatively representing the loaded state amount is the center of gravity position of the vehicle. Therefore, it is beneficial for driving the vehicle if the wheel scale of the vehicle and the position of the center of gravity of the vehicle can be derived using the truck scale.

  By the way, conventionally, the amount that can be accurately measured using a truck scale is considered to be the total weight and axle weight of the vehicle, and accurate wheel load measurement is difficult, and the center of gravity position measurement is impossible. Has been.

  Therefore, a track scale has already been proposed that can guide the wheel load of the vehicle using an attached measuring device (for example, an ultrasonic measuring instrument) that measures the position where the vehicle enters the platform and the tread interval of the vehicle. (For example, refer to Patent Document 1).

JP 2006-3291 A

  However, the track scale described in Patent Document 1 has the following problems.

  First, a separate measuring device for measuring the position where the vehicle enters the platform is required separately. Therefore, the cost of the track scale is increased and the configuration is complicated.

  Secondly, Patent Document 1 does not intend to guide the position of the center of gravity of the vehicle.

  In addition, since the center of gravity of the vehicle generally exists in a three-dimensional space, three variables are required to determine its position, but in this specification, measurement of the center of gravity in the vertical direction is not an object. In addition, the measurement of the other two barycentric positions is targeted. Further, in the present specification, the above-described two center positions of gravity are referred to as “horizontal center positions” as necessary.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a track scale that can guide the wheel load of a vehicle only by changing the mounting shape of a conventional track scale.

  Another object of the present invention is to provide a track scale that can guide the horizontal center-of-gravity position of a vehicle only by changing the mounting shape of a conventional track scale.

  The inventors of the present invention have noticed that the tire ground contact length for each wheel of the vehicle can be derived in the process of deriving the horizontal plane center of gravity position of the vehicle. And if the quality of tire air pressure can be determined based on the tire ground contact length for each wheel of the vehicle, it is considered extremely useful for driving the vehicle.

  Therefore, the present invention also aims to provide a track scale that can determine the quality of tire air pressure based on the tire ground contact length for each wheel of a vehicle by simply changing the mounting shape of a conventional track scale. To do.

  By the way, the conventional platform of the track scale is composed of a rectangular plate member. Then, the vehicle enters from one side of the short side of the main stage and exits from the other side.

  On the other hand, the feature of the track scale of the present invention is that, in order to solve the above-described problem, the conventional track scale platform is provided with a projecting portion that projects from a part of the platform shorter side on the vehicle entry side. (Hereinafter, such a track scale may be abbreviated as “new track scale”).

  As a result, in the new truck scale, a time interval in which only one wheel of the vehicle acts on the platform is generated, and the wheel load and the horizontal center of gravity position of the vehicle and the tire ground contact length are obtained by effectively using this effect. be able to. It should be noted that conventional track scale control system hardware can be used as it is for the calculation of the wheel load, horizontal plane center of gravity, and tire ground contact length of a new truck scale vehicle.

The present invention has been devised for the first time based on such knowledge, and it is possible that only the left and right wheels of the vehicle can get on the platform main body on which both the left and right wheels of the vehicle can ride. A mounting base that protrudes from the end of the base body described above,
A plurality of load cells that support the table described above from below;
An output signal from the load cell when only one of the left and right wheels of the vehicle is placed on the above-mentioned stand protruding portion, and from the load cell when both left and right wheels of the vehicle are placed on the stand described above There is provided a truck scale comprising computing means for computing the wheel weights of both the left and right wheels of the vehicle based on an output signal.

  With this configuration, the track scale of the present invention can give a function of measuring the wheel load of a vehicle to the conventional track scale only by changing the mounting shape of the conventional track scale.

In addition, the present invention provides a mounting body that can carry both the left and right wheels of the vehicle, and a mounting that protrudes from the end of the above-described mounting body so that only one of the left and right wheels of the vehicle can ride. A platform comprising a platform projection,
A plurality of load cells that support the table described above from below;
An output signal from the load cell when only one of the left and right wheels of the vehicle is placed on the above-mentioned stand protruding portion, and from the load cell when both left and right wheels of the vehicle are placed on the stand described above There is also provided a truck scale comprising computing means for computing a planar center of gravity position of the vehicle based on the output signal.

  With this configuration, the track scale of the present invention can give the function of measuring the planar center of gravity position to the conventional track scale only by changing the mounting shape of the conventional track scale.

  In the track scale of the present invention, the calculation means may calculate the tread interval of the vehicle using the output signal and the wheel load.

  With this configuration, the track scale of the present invention can also provide a function of measuring the tread interval to the conventional track scale.

  In the track scale of the present invention, the calculation means may calculate the center of gravity position in the width direction of the vehicle using the wheel load, the axle load of the vehicle, and the tread interval of the vehicle.

  With this configuration, the track scale of the present invention can give a function of measuring the position of the center of gravity in the width direction of the vehicle to the conventional track scale.

  In the track scale of the present invention, the computing means may compute the inter-axis distance of the vehicle using the time waveform of the output signal.

  With such a configuration, the track scale of the present invention can also give a function of measuring the distance between the axes of the vehicle to the conventional track scale.

  In the track scale of the present invention, the calculating means may calculate the center-of-gravity position in the full length direction of the vehicle using the inter-axis distance and the axle weight of the vehicle.

  With this configuration, the track scale of the present invention can give a function of measuring the position of the center of gravity in the full length direction of the vehicle to the conventional track scale.

  In the track scale of the present invention, the calculating means may calculate the tire contact length when the tire contact lengths of the left and right wheels of the vehicle are assumed to be the same using the time waveform of the output signal. Good.

  With this configuration, the track scale of the present invention can provide a function of measuring the tire contact length when assuming that the tire contact lengths of the left and right wheels of the vehicle are the same as those of the conventional track scale.

  In the track scale of the present invention, the computing means may determine whether the tire air pressure of the wheel is good or not based on the tire ground contact length.

  With such a configuration, the track scale of the present invention can give a function of determining whether the tire air pressure is good or bad to the conventional track scale using the tire ground contact length.

  In the track scale of the present invention, the computing means may determine whether the tire air pressure of the wheel is good or not based on the tire ground contact length and the wheel load.

  With this configuration, the track scale of the present invention can give a function to determine whether the tire pressure is good or bad to the conventional track scale using the tire contact length and the wheel load.

In addition, the present invention provides a mounting body that can carry both the left and right wheels of the vehicle, and a mounting that protrudes from the end of the above-described mounting body so that only one of the left and right wheels of the vehicle can ride. A platform comprising a platform projection,
A plurality of load cells that support the table described above from below;
The time waveform of the output signal from the load cell when only one of the left and right wheels of the vehicle is placed on the above-mentioned stand protruding portion, and the above when the both left and right wheels of the vehicle are placed on the above-mentioned stand A calculation means for calculating a tire ground contact length for each of the left and right wheels of the vehicle based on a time waveform of an output signal from a load cell;
A track scale is also provided.

  With this configuration, the track scale of the present invention provides a function to measure the tire ground contact length for each of the left and right wheels of the vehicle by simply changing the mounting shape of the conventional track scale. Can do.

  In the track scale of the present invention, the computing means may determine whether the tire air pressure for each wheel is good or not based on the tire ground contact length for each wheel.

  With such a configuration, the track scale of the present invention can give a function of determining whether the tire air pressure for each wheel is good or bad to the conventional track scale using the tire ground contact length for each wheel.

  Further, in the track scale of the present invention, the calculating means outputs an output signal from the load cell when only one of the left and right wheels of the vehicle is placed on the above-described table protrusion, and both the left and right sides of the vehicle. The wheel weights of both the left and right wheels of the vehicle may be calculated based on an output signal from the load cell when the wheels are placed on the table. And the said calculating means may determine the quality of the tire pressure for every said wheel based on the tire ground contact length for every said wheel and the said wheel load.

  With such a configuration, the track scale of the present invention can give a function of determining whether the tire air pressure for each wheel is good or bad to the conventional track scale using the tire ground contact length and wheel weight for each wheel.

  Moreover, in the track scale of the present invention, the load cell may be disposed below the above-described stand protruding portion and the above-described stand main body.

  With such a configuration, in the track scale of the present invention, it is possible to appropriately compensate for the insufficient strength of the mounting protrusion by supporting the mounting protrusion using the load cell.

  Moreover, in the track scale of the present invention, the above-described table may include a first table protrusion and a second table protrusion protruding from the end of the table main body. And you may distribute the said load cell under the 1st mounting base protrusion part and the 2nd mounting base protrusion part. Furthermore, when either one of the left and right wheels of the vehicle rides on the first platform protrusion, the left and right wheels of the vehicle have the first platform protrusion and the second platform protrusion. You may pass through the notch of the above-mentioned stand between.

  With this configuration, in the track scale according to the present invention, it is possible to appropriately compensate for the insufficient strength of the first mounting table protrusion by supporting the first mounting table protrusion using the load cell.

  The track scale of the present invention may further comprise means for preventing the wheel from entering the second platform protrusion.

  In the truck scale according to the present invention, when one of the left and right wheels of the vehicle rides on the first platform protrusion, the left and right wheels of the vehicle move to the first platform protrusion and When the left or right wheel of the vehicle passes through the notch portion of the above-described table between the second platform protrusions and the left or right wheel of the vehicle rides on the second platform projection, either the left or right of the vehicle A wheel may pass through the notch part of the above-mentioned stand between the said 1st mounting base protrusion part and the said 2nd mounting base protrusion part.

  With this configuration, in the track scale of the present invention, the right wheel and the left wheel of the vehicle can be placed on the platform at different timings regardless of the position of the vehicle that enters the platform.

  According to the track scale of the present invention, the function of measuring the wheel load of the vehicle can be given to the conventional track scale.

  Further, according to the track scale of the present invention, a function of measuring the horizontal center of gravity position of the vehicle can be given to the conventional track scale.

  Furthermore, according to the track scale of the present invention, it is possible to give a function to determine whether the tire air pressure is good or not based on the tire ground contact length for each vehicle wheel to the conventional track scale.

FIG. 1 is a diagram showing an example of a schematic structure of a new track scale according to the first embodiment of the present invention. FIG. 4A shows a plan view of the new track scale, and FIG. 4B shows a side view of the new track scale. FIG. 2 is a block diagram showing an example of the configuration of the new track scale control system of FIG. FIG. 3 is a functional block diagram of the new track scale control device of FIG. FIG. 4 is a diagram used for explaining the tire contact surface and the tire contact length of the vehicle. FIG. 5 is a schematic diagram used for explaining the wheel load derivation of the first axis of the vehicle by the wheel load calculation unit of FIG. 3. FIG. 6 is a schematic diagram used for explaining the wheel load derivation of the first axis of the vehicle by the wheel load calculation unit of FIG. 3. FIG. 7 is a diagram used for explaining the wheel load derivation of the second axis of the vehicle by the wheel load calculation unit of FIG. 3. FIG. 8 is a diagram used for explaining the wheel load derivation of the second axis of the vehicle by the wheel load calculation unit of FIG. 3. FIG. 9 is a diagram used for explaining the derivation of the horizontal center of gravity position of the vehicle by the center of gravity position calculation unit of FIG. FIG. 10 is a diagram used for explaining the centroid position derivation in the width direction of the vehicle by the centroid position calculator of FIG. FIG. 11 is a diagram used for explaining the centroid position derivation in the full length direction of the vehicle by the centroid position calculation unit of FIG. 3. FIG. 12 is a diagram showing an output waveform (time waveform) of the load cell when both wheels of the first shaft of the vehicle of FIG. 1 get on the platform. FIG. 13 is a diagram showing an output waveform (time waveform) of the load cell when both wheels of the first shaft and both wheels of the second shaft of the vehicle of FIG. 1 get on the platform. FIG. 14 is a diagram showing an example of a schematic structure of a new track scale according to the second embodiment of the present invention. FIG. 4A shows a plan view of the new track scale, and FIG. 4B shows a side view of the new track scale. FIG. 15 is a functional block diagram of the new track scale control device of FIG. FIG. 16 is a diagram showing an output waveform (time waveform) of the load cell when both wheels of the first shaft and both wheels of the second shaft of the vehicle in FIG. 14 get on the platform. FIG. 17 is a diagram showing an example of a schematic structure of a new track scale according to the first modification of the present invention. FIG. 18 is a diagram showing an example of a schematic structure of a new track scale according to the second modified example of the present invention. FIG. 19 is a diagram showing an example of a schematic structure of a new track scale according to the third modified example of the present invention. FIG. 20 is a diagram illustrating an example of a schematic structure of a new track scale according to a fourth modification of the present invention. FIG. 21 is a diagram showing an example of a schematic structure of a new track scale mounting table according to a sixth modification of the present invention. FIG. 22 is a diagram showing an output waveform (time waveform) of the load cell when both wheels of the first shaft and both wheels of the second shaft of the vehicle get on the platform of FIG.

  Hereinafter, preferred first and second embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and description of the overlapping elements may be omitted. Further, the present invention is not limited to the following first and second embodiments. That is, the following descriptions of the first and second embodiments merely illustrate the features of the new track scale.

  For example, the present invention is not limited to a specific arithmetic expression in the formulation of the wheel load and the horizontal center of gravity position exemplified in the following first embodiment, and the tire contact length formulation exemplified in the second embodiment. It is not limited to a specific arithmetic expression in.

(First embodiment)
[Configuration of new track scale]
FIG. 1 is a diagram showing an example of a schematic structure of a new track scale according to the first embodiment of the present invention. FIG. 2A shows a plan view of the new track scale. FIG. 4B shows a side view of the new track scale.

  In the present embodiment, for convenience, in FIG. 1, the full length direction of the vehicle 10 is illustrated as “front” and “rear” directions, and the width direction of the vehicle 10 is illustrated as “left” and “right” directions. Yes. The configuration of the new truck scale 100 will be described below, assuming that the vehicle 10 enters from “rear” of the platform 20 and exits from “front” of the platform 20.

  As shown in FIG. 1, the new truck scale 100 includes a platform 20 on which a vehicle 10 such as a truck or a trailer can ride, a first load cell LC1, a second load cell LC2, a third load cell LC3, and a fourth load cell LC4 ( Hereinafter, the load cells LC1, LC2, LC3, and LC4 may be collectively referred to as “load cells LC1 to LC4”).

  Here, as the vehicle 10, the front axle 13 with wheels 11a and 11b attached is one below the driver's seat, and the rear axle 14 with wheels 12a and 12b attached is one below the loading platform. A four-wheel truck in which a total of two axles 13 and 14 are arranged is illustrated.

  As shown in FIG. 1, the mounting table 20 includes a mounting body 21 and a mounting protrusion 22.

  When the new track scale 100 is viewed in plan (FIG. 1A), a rectangular groove 21 </ b> A is formed on the surface of the installation base 25. And as shown in FIG. 1, the mounting base 20 and the cover member 26 are distribute | arranged to this groove part 21A.

  The lid member 26 is a member provided for the purpose of closing the groove space between the mounting table 20 and the installation base 25. Therefore, instead of providing such a lid member 26, the groove portion of the installation base 25 may be formed along the shape of the mounting base 20 in plan view (that is, slightly larger than the mounting base 20 and similar in shape). Groove). However, it is considered that the provision of the lid member 26 as in the present embodiment is advantageous in terms of the cost of the new truck scale 100.

  Further, as shown in FIG. 1A, the mounting body 21 has a right end portion 21R and a left end portion 21L extending in the front-rear direction as long sides and a front end portion 21F and a rear end portion 21B extending in the left-right direction as short sides. , And a rectangular plate member having an overall length L and a width dimension H. As described above, the platform main body 21 of the new track scale 100 has the same form as the conventional track scale platform.

  On the other hand, the mounting table protrusion 22 is formed by extending the rear half 21B of the mounting body 21 from the rear end 21B of the mounting body 21 rearward as it is.

  That is, in the new track scale 100 of the present embodiment, the mounting table 20 is integrally configured by the rectangular mounting body 21 and the rectangular mounting protrusion 22.

  However, the structure of the mounting base 21 and the mounting protrusion 22 described above is an example, and can be modified to various structures.

  For example, the mounting body 21 and the mounting protrusion 22 may be configured separately and formed integrally using appropriate fixing means (welding, bolt fastening, etc.).

Further, the width H ₁ of the platform the projection 22, as in this embodiment, only one wheel left or right of the vehicle 10 (in this case, the right wheel 11a, 12a only) that rides the platform protruding portion 22 However, it is not necessarily limited to this, although it is preferable to set to about half the width dimension H of the mounting body 21 so that it can be performed.

For example, even if the width dimension H ₁ of the platform protrusion 22 is slightly larger than half the width dimension H of the platform body 21, only one of the left and right wheels of the vehicle 10 is placed on the platform protrusion 22. There are cases where it is possible. In this case, since the platform protrusion can be configured to be wide, the strength of the platform protrusion can be improved.

Moreover, the shape of the mounting table protrusion 22 is not necessarily rectangular. For example, if the protrusion dimension L ₁ (the dimension in the front-rear direction) of the mounting protrusion 22 can be made sufficiently longer than the tire ground contact length S (details will be described later) of the vehicle 10, another shape (for example, , A shape such as a chamfered corner of the mounting protrusion, or the like.

  Further, as shown in FIG. 1, the four load cells LC <b> 1 to LC <b> 4 are respectively arranged on the installation base 25 below the mounting table 20 at the four corners of the mounting body 21.

  Specifically, the first load cell LC1 and the third load cell LC3 are spaced apart from each other on a straight line parallel to the rear end portion 21B in the vicinity of the rear end portion 21B of the mounting body 21 (dimension b; see, for example, FIG. 6). The second load cell LC2 and the fourth load cell LC4 are arranged in the vicinity of the front end portion 21F of the mounting body 21 on the straight line parallel to the front end portion 21F (same dimension b; for example, see FIG. 6). Are lined up.

  On the other hand, the first load cell LC1 and the second load cell LC2 are arranged at a constant interval (dimension a; for example, see FIG. 6) on a straight line parallel to the left end 21L in the vicinity of the left end 21L of the mounting body 21. The third load cell LC3 and the fourth load cell LC4 are separated from each other by the same distance (dimension a; for example, see FIG. 6) on the straight line parallel to the right end 21R in the vicinity of the right end 21R of the mounting body 21. Are lined up.

  From the above, the mounting table 20 (here, the mounting body 21) is supported from below by the load cells LC1 to LC4 on the installation base 25.

  As described above, the feature of the new track scale 100 of the present embodiment is that the above-described platform protrusion 22 is arranged on a rectangular platform of the conventional track scale (that is, a platform corresponding to the platform main body 21). is there. In the new truck scale 100 according to the present embodiment, the function described above can add the function of measuring the wheel load and the horizontal center of gravity of the vehicle 10 to the conventional truck scale, the details of which will be described later.

[New track scale control system configuration]
FIG. 2 is a block diagram showing an example of the configuration of the new track scale control system of FIG. FIG. 3 is a functional block diagram of the new track scale control device of FIG.

  As shown in FIG. 2, the new track scale 100 includes a control device 40, an operation device 41, and a display device 42.

  The control device 40 includes, for example, a plurality (here, four) amplifiers 43, a plurality (four here) low-pass filters 44, a multiplexer 45, and A / D conversion corresponding to each of the load cells LC1 to LC4. A calculator 46, an I / O circuit 47, a memory 48, and a calculator 49.

  The amplifier 43 has a function of amplifying a signal transmitted from the load cells LC1 to LC4 to a size capable of A / D conversion and sending it out.

  The low pass filter 44 has a function of passing only a low frequency as a signal.

  The multiplexer 45 has a function of selectively sending out a plurality of signals transmitted from each of the low-pass filters 44 based on a selection control signal command from the computing unit 49.

  The A / D converter 46 has a function of converting an analog signal from the multiplexer 45 into a digital signal.

  The I / O circuit 47 has a function of exchanging various signals and data among the A / D converter 46, the operation device 41, the display device 42, the memory 48, and the arithmetic unit 49.

  The memory 48 is composed of, for example, a PROM, a RAM, and the like, and has a function of storing a predetermined program, basic data, and the like for a long time, and temporarily storing various data, numerical values for calculation, and the like.

  The arithmetic unit 49 is constituted by a processing device such as a microprocessor (MPU), for example, and receives necessary signals via the I / O circuit 47 in accordance with instructions of a predetermined program stored in the memory 48, and necessary data. Is received from the memory 48 and has a function of executing an operation based on the received signal and data.

  The operation device 41 includes operation switches, numerical keys, and the like, and is used in various operations such as measurement start / end operations, zero point adjustment operations, use mode switching operations, and numerical value setting operations.

  The display device 42 is composed of, for example, a liquid crystal display panel or the like, and displays measurement results and various data input / output screens.

[Processing of new track scale control system]
In the control system of the new track scale 100, the output signals of the load cells LC1 to LC4 are sent to the arithmetic unit 49 via the amplifier 43, the low-pass filter 44, the multiplexer 45, the A / D converter 46 and the I / O circuit 47. Sent. The arithmetic unit 49 takes in a signal from the I / O circuit 47 according to a predetermined program stored in the memory 48 and reads various data stored in the memory 48.

  Thereby, the calculator 49 calculates various useful loading state quantities that can support the driving of the vehicle 10 based on these signals and data, and the calculation result is displayed on the display device 42.

  And in the new track scale 100 of this embodiment, in the control apparatus 40, when the predetermined program is executed by the calculator 49, as shown in FIG. 3, the wheels 11a, 11b, 12a, 12b of the vehicle 10 are shown. A wheel load calculating unit 51 for calculating the weight, a gravity center position calculating unit 52 for calculating the horizontal center of gravity of the vehicle 10, a total weight calculating unit 53 for calculating the total weight of the vehicle 10, and the axle weights of the axles 13 and 14 of the vehicle 10. The functions of the axle load calculation unit 54 and the display signal generation unit 55 are calculated.

  Note that the control device 40 does not necessarily need to be composed of a single computing unit 49, and a plurality of computing units are arranged in a distributed manner so that they cooperate to control the operation of the new track scale 100. May be. For example, the function of the wheel load calculation unit 51, the function of the center of gravity position calculation unit 52, the function of the total weight calculation unit 53, and the function of the axle load calculation unit 54 are realized here using a single calculator 49. However, these functions may be realized by using a separate arithmetic unit (MPU).

  Therefore, hereinafter, the functions of the wheel load calculation unit 51, the center-of-gravity position calculation unit 52, the total weight calculation unit 53, and the axle load calculation unit 54 of the new truck scale 100 will be described in order. The function of the display signal generation unit 55 is known. Therefore, the function description of the display signal generation unit 55 is omitted here.

[Definition of symbols]
First, the meanings of symbols used in the following description and related drawings are collectively defined.

<Vehicle related (for example, see FIG. 9 and FIG. 12)>
X axis: a center line extending in the full length direction through the center position in the width direction of the vehicle 10 Y axis: a straight line O (large o) along the front axle 13 (hereinafter referred to as “first axis 13”) of the vehicle 10: X W _R1 : Wheel weight of the right wheel 11a of the first shaft 13 of the vehicle 10 W _L1 : Wheel weight of the left wheel 11b of the first shaft 13 W _R2 : Axle 14 on the rear side of the vehicle 10 ( Hereinafter, the wheel weight W _L2 of the right wheel 12a of the “second shaft 14”: the wheel weight of the left wheel 12b of the second shaft 14 W ₁ : the shaft weight of the first shaft 13 W ₂ : the shaft of the second shaft 14 Weight W: Total weight of the vehicle 10 _G : Center of gravity of the vehicle 10 X _G : Position of the center of gravity of the vehicle 10 in the orthogonal coordinate system O-XY Y _G : Position of the center of gravity of the vehicle 10 in the width direction in the orthogonal coordinate system O-XY B ₁ : Tread interval of the first shaft 13 of the vehicle 10 B ₂ : Tread of the second shaft 14 of the vehicle 10 Red interval l (Small L) ₁₂ : Distance between the first shaft 13 and the second shaft 14 (distance between the axes)
S: Tire contact length (in this embodiment, it is assumed that the tire contact length S is the same for all wheels 11a, 11b, 12a, 12b)

<Load cell related (for example, see FIGS. 6 and 8)>
P ₁ : Output of the first load cell LC 1 P ₂ : Output of the second load cell LC 2 P ₃ : Output of the third load cell LC 3 P ₄ : Output of the fourth load cell LC 4 P ₁₂ : Output of the first load cell LC 1 and the second load cell LC 2 Sum (P ₁₂ = P ₁ + P ₂ )
P ₁₃ : Sum of outputs of first load cell LC1 and third load cell LC3 (P ₁₃ = P ₁ + P ₃ )
P ₂₄ : Sum of outputs of second load cell LC2 and fourth load cell LC4 (P ₂₄ = P ₂ + P ₄ )
P ₃₄ : Sum of outputs of third load cell LC3 and fourth load cell LC4 (P ₃₄ = P ₃ + P ₄ )
P: Sum of outputs of all load cells LC1 to LC4 (P = P ₁ + P ₂ + P ₃ + P ₄ )
a: Distance between the centers of the first load cell LC1 (third load cell LC3) and the second load cell LC2 (fourth load cell LC4) b: First load cell LC1 (second load cell LC2) and third load cell LC3 (fourth load cell LC4) B ₁ : Distance between the center of the first load cell LC1 and the point of application of the wheel load W _L1 of the first shaft 13 b ₁ ': Wheel load W of the center of the third load cell LC3 and the first shaft 13 the distance between the point of action of the _R1 b _2: a distance b ₂ between the point of action of the wheel load _{W L2} and the center of the second shaft 14 of the first load cell LC1 ': wheel load and the center of the second shaft 14 of the third load cell LC3 the distance between the point of action of W _R2 Incidentally, of the above symbols, the distance a, b is a value that is known (fixed value which depends on the arrangement of the load cell LC1 to LC4), these values are stored in advance in the memory 48 ing.

<Platform related (for example, see FIGS. 1, 6 and 13)>
x-axis: mounting body center line extending in the full length direction through the center position in the width direction of the mounting body 21 y axis: mounting body center line in the width direction passing through the center position in the full length direction of the mounting body 21 o ( Small O): intersection of the x-axis and y-axis (center point of the mounting body 21)
L ₁ : Projection dimension of the mounting table protrusion 22 L ₀ : Distance between the rear end 21B of the mounting table body 21 and the center of the first load cell LC1 (third load cell LC3) L: Total length of the mounting table body 21 Among the symbols, the distances L ₁ , L ₀ , L are known values (fixed values depending on the shape of the mounting table 20), and these values are stored in the memory 48 in advance.

<Relationship between relative position of vehicle and platform (for example, see FIG. 6)>
d: distance between the center point M ₁ and the platform body center line of the tread gap between the first axis 13 (x-axis)

<Related to output waveform of load cell (for example, see FIGS. 12 and 13)>
As shown in FIG. 4, in each tire of both wheels 11 a and 11 b of the first shaft 13 (the same applies to the second shaft 14) of the vehicle 10, a tire ground contact surface 30 is provided between the installation base 25 and the mounting base 20. The tire has a tire contact length S. Therefore, when the vehicle 10 gets on the platform 20, the output waveforms of the outputs P of the load cells LC1 to LC4 show a plurality of break points as shown in FIGS. 12 and 13, and break points of these output waveforms. The times t ₀ , t ₁ , t ₂ , t ₃ , t ₄ , t ₅ , t ₆ , t ₇ , t ₈ corresponding to can be defined as follows.

t ₀ : When the tire of the right wheel 11 a of the first shaft 13 starts to get on the mounting protrusion 22 t ₁ : When the tire of the right wheel 11 a of the first shaft 13 is completely mounted on the mounting protrusion 22 t ₂ : When the tire of the left wheel 11 b of the first shaft 13 starts to enter the mounting body 21 t ₃ : When the tire of the left wheel 11 b of the first shaft 13 is completely mounted on the mounting body 21 t ₄ : tire right wheel 12a of the second shaft 14, when t ₅ to begin boarded the platform protruding portion 22: tire right wheel 12a of the second shaft 14, t ₆ when resting entirely on the platform protruding portion 22 : tire left wheel 12b of the second shaft 14, when t ₇ begins boarded the platform body 21: tire left wheel 12b of the second shaft 14, when resting completely the platform body 21 t _8: time after a t _7, suitable between the vehicle 10 is resting on completely the platform body 21

[Function of wheel load calculation unit]
Hereinafter, the function of the wheel load calculation unit 51 of the new track scale 100 will be described.

<Method for deriving wheel load of first shaft of vehicle>
5 and 6 are schematic diagrams used to explain the wheel load deriving of the first shaft of the vehicle by the wheel load calculating unit of FIG.

Here, since the purpose is to understand the method of deriving the wheel loads W _R1 and W _L1 of the first shaft 13 of the vehicle 10, the configuration of the new truck scale 100 that is not directly related to the present deriving method is illustrated for convenience. Omitted or simplified. For example, in FIG. 5 and FIG. 6, the installation base 25 (see FIG. 1) is not shown.

  In addition, the illustration of the configuration of the vehicle 10 is simplified as appropriate, for example, the first shaft 13 is abbreviated with its center line.

Further, in FIG. 5, distances b ₁ ′ and b are written together, and these distances b ₁ ′ and b are appropriately referred to in the functional description (described later) of the gravity center position calculation unit 52. In FIG. 6, the orthogonal coordinate system o-xy and the distances b ₁ , b ₁ ′, B ₁ , d, a, and b related thereto are written together, and the function description of the gravity center position calculation unit 52 ( In the following description, these orthogonal coordinate systems o-xy and distances b ₁ , b ₁ ′, B ₁ , d, a, b are appropriately considered.

FIG. 5 schematically illustrates the positions of both wheels 11a and 11b on the first shaft 13 of the vehicle 10 in the time section [t ₁ , t ₂ ]. In this case, P (t) is an output signal from the load cells LC1 to LC4 when only the right wheel 11a of the first shaft 13 of the vehicle 10 is placed on the platform 20 (here, on the platform protrusion 22). corresponds to the sum of the load signal), this value corresponds to the wheel load W _R1.

Therefore, the wheel load W _R1 can be obtained by the following equation (1).

Wheel load W _R1 = P (t) (1)
In equation (1), t is the time within the time interval [t ₁ , t ₂ ].

On the other hand, FIG. 6 schematically illustrates the positions of both wheels 11a and 11b on the first shaft 13 of the vehicle 10 in the time interval [t ₃ , t ₄ ]. In this case, P (t) is an output signal from the load cells LC1 to LC4 when both wheels 11a and 11b of the first shaft 13 of the vehicle 10 are placed on the platform 20 (here, on the platform body 21). corresponds to the sum of the load signal), this value corresponds to axle load W _1.

Therefore, wheel load _{W L1} can be determined by the following equation (2).

Wheel load W _L1 = P (t) −W _R1 = W ₁ −W _R1 (2)
In equation (2), t is the time within the time interval [t ₃ , t ₄ ].

As described above, in the new truck scale 100 of the present embodiment, the wheel load calculation unit 51 calculates the wheel loads W _R1 and W _L1 of the first shaft 13 of the vehicle 10 using the above formulas (1) and (2). It can be calculated.

<Method for deriving wheel load of second axis of vehicle>
FIGS. 7 and 8 are diagrams used for explaining the wheel load derivation of the second axis of the vehicle by the wheel load calculation unit of FIG. 3.

Here, since the purpose is to understand the method for deriving the wheel loads W _R2 and W _L2 of the second shaft 14 of the vehicle 10, the illustration of the configuration of the new truck scale 100 that is not directly related to the present deriving method is shown for convenience. Omitted or simplified. For example, in FIGS. 7 and 8, the installation base 25 (see FIG. 1) is not shown.

  In addition, the illustration of the configuration of the vehicle 10 is simplified as appropriate, for example, the first shaft 13 and the second shaft 14 are abbreviated only by their center lines.

Further, in FIG. 7, the distances b ₂ ′ and b are written together as in FIG. 5. In FIG. 8, as in FIG. 6, the orthogonal coordinate system o-xy and the distances b ₂ , b ₃ ′, B ₂ , a, and b related thereto are also shown.

In FIG. 7, the positions of the wheels 11 a and 11 b of the first shaft 13 and the positions of the wheels 12 a and 12 b on the second shaft 14 in the time section [t ₅ , t ₆ ] are schematically shown. Illustrated. In this case, P (t) indicates that both the wheels 11a and 11b of the first shaft 13 of the vehicle 10 and the right wheel 12a of the second shaft 14 are on the mount 20 (here, the first shaft 13 is on the mount main body 21, the second axis corresponds to the sum of the output signal (load signal) from the load cell LC1~LC4 when placed on the weighing platform upper protrusion portion 22), this value is the sum of the axle load _{W 1} and the wheel load _{W R2} It corresponds to.

Therefore, wheel load _{W R2} can be determined by the following equation (3).

Wheel load W _R2 = P (t) −W ₁ (3)
In Expression (3), t is the time within the time interval [t ₅ , t ₆ ].

On the other hand, in FIG. 8, the positions of both wheels 11a, 11b of the first shaft 13 and the positions of both wheels 12a, 12b of the second shaft 14 in the time section [t ₇ , t ₈ ] are schematically shown. Is exemplified. In this case, as for P (t), both wheels 11a and 11b of the first shaft 13 and both wheels 12a and 12b of the second shaft 14 are mounted on the mounting 20 (here, on the mounting main body 21). corresponds to the sum of the output signal (load signal) from the load cell LC1~LC4 of time, this value corresponds to the sum of the axle load _{W 1} and the axle load _{W 2.}

Therefore, wheel load _{W L2} can be determined by the following equation (4).

Wheel load W _L2 = P (t) − (W ₁ + W _R2 ) (4)
In equation (4), t is the time within the time interval [t ₇ , t ₈ ].

As described above, in the new truck scale 100 of the present embodiment, the wheel load calculating unit 51 calculates the wheel loads W _R2 and W _L2 of the second shaft 14 of the vehicle 10 using the above formulas (3) and (4). can do.

[Function of center of gravity position calculation unit]
Hereinafter, the function of the gravity center position calculation unit 52 of the new track scale 100 will be described.

<Description of horizontal center of gravity (X _G , Y _G )>
First, the contents of the horizontal center of gravity position (X _G , Y _G ) of the vehicle 10 will be described with reference to the drawings.

  FIG. 9 is a diagram used for explaining the derivation of the horizontal center of gravity position of the vehicle by the center of gravity position calculation unit of FIG.

  As shown in FIG. 9, in the new truck scale 100 of the present embodiment, in the formulation of the position of the center of gravity G of the vehicle 10, the vehicle 10 extends along the vehicle center line extending in the full length direction through the center position in the width direction of the vehicle 10. The axis is defined, the Y axis is defined along the first axis 13, and the origin O is set at the intersection of the X axis and the Y axis.

That is, the new track scale 100 of the present embodiment is characterized in that the horizontal plane center of gravity position (X _G , Y _G ) corresponding to the position of the center of gravity G of the vehicle is obtained with reference to the orthogonal coordinate system O-XY. . Thus, the position of the center of gravity G can be simply formulated as follows by considering the orthogonal coordinate system O-XY without depending on the orthogonal coordinate system o-xy of FIG.

<Derivation method of coordinate _{Y G>}
As shown in FIG. 9, the coordinate Y _G represents the position of the center of gravity of the vehicle width direction in the orthogonal coordinate system O-XY.

Here, the coordinate Y _G can be expressed by the following equation (5) from the equation of moment balance.
Y _G = {B ₁ (W _L1 −W _R1 ) + B ₂ (W _L2 −W _R2 )} / 2 (W ₁ + W ₂ )
... (5)
In equation (5), when the tread interval B ₁ of the first shaft 13 of the vehicle 10 and the tread interval B ₂ of the second shaft 14 of the vehicle 10 can be obtained, the coordinate Y _G is calculated based on the equation. it can.

Determination of the following tread spacing B _1, how to determine the tread spacing B _1, is described with reference to FIGS. 5 and 6 above.

In FIG. 5, the distance b ₁ ′ can be expressed by the following equation (6) from the equation of moment balance.

b ₁ ′ = P ₁₂ (t) · b / W _R1 (6)
Here, P ₁₂ (t) = P ₁ (t) + P ₂ (t)
Further, in the equation (6), t is the time of the time interval _[t 1, _{t 2]} within.

  On the other hand, in FIG. 6, the following formula (7) of moment balance is established, and as a result, the relational expression of formula (8) is obtained.

b · P ₁₂ (t) −W _R1 · b ₁ ′ −W _L1 · (b−b ₁ ) = 0 (7)
b ₁ = b− (b · P ₁₂ (t) −W _R1 · b ₁ ′) / W _L1 (8)
Here, P ₁₂ (t) = P ₁ (t) + P ₂ (t)
In the equations (7) and (8), t is the time in the time interval [t ₃ , t ₄ ].

Here, since the geometric relationship of the following equation (9) is established between the tread interval B ₁ and the distances b, b ₁ , b ₁ ′, the distance b, which is a known value, and the above equation ( By substituting the distances b ₁ and b ₁ ′ that can be derived using 6) and Expression (8) into Expression (9), the tread interval B ₁ can be calculated.

B ₁ = b− (b ₁ + b ₁ ′) (9)

Determination of the tread spacing B ₂ Next, the method of obtaining the tread spacing B _2, will be described with reference to the drawings.

First, when obtaining the tread distance B _2, provided the following assumptions.

“Assumption: The distance d (see FIG. 6) from the center line (x axis) of the midpoint M ₁ of the tread interval B ₁ of the first shaft 13 is constant regardless of the movement of the vehicle 10. ]
Here, before and after the right wheel 12a of the second shaft 14 of the vehicle 10 gets on the platform 20, the force (on the wheel load) acting on the platform 20 when the platform 20 is viewed from the full length direction (front-rear direction). Consider changes in load force and reaction force from the load cell.

  In FIG. 10A, the mounting table 20 when the wheels 11 a and 11 b of the first shaft 13 of the vehicle 10 are on the mounting table 20 is viewed from the full length direction (front-rear direction). The force acting on the platform 20 is shown. Further, in FIG. 10B, the platform 20 when the wheels 11 a and 11 b of the first shaft 13 of the vehicle 10 and the right wheel 12 a of the second shaft 14 of the vehicle 10 are on the platform 20 is shown. The force which acts on the mounting base 20 when seen from the full length direction (front-back direction) is shown.

When the above assumption is made, the position at which the wheel load W _R1 acts and the position at which the wheel load W _L1 acts are both on the table 20 in FIG. 10A and on the table 20 in FIG. When the stage 20 is viewed from its full length direction, the position where these act is supposed to be the same in the same direction of the stage 20 without changing.

Then, the _P 12 (t) in the time interval _[t 3, t _4], the difference between _P 12 and (t) in the time interval _[t 5, t _6], caused only by the action of the wheel load _{W R2} It is considered a thing.

Therefore, the distance b ₂ ′ can be expressed by the following equation (10) from the equation of moment balance with reference to the third load cell LC3 (fourth load cell LC4), and the distance b ₂ ′ Can be calculated.

b ₂ ′ = ΔP ₁₂ (t) · b / W _R2 (10)
In Equation (10), ΔP ₁₂ (t) is calculated from the value of P ₁₂ (t) (= P ₁ (t) + P ₂ (t)) in the time interval [t ₅ , t ₆ ] to the time interval [t ₃ , It is a value obtained by subtracting the value of P ₁₂ (t) (= P ₁ (t) + P ₂ (t)) at t ₄ ].

  Next, before and after the left wheel 12b of the second shaft 14 of the vehicle 10 gets into the platform 20, the force (on the wheel load) acting on the platform 20 when the platform 20 is viewed from the full length direction (front-rear direction). Consider changes in load force and reaction force from the load cell.

  In FIG. 10 (b), both the wheels 11a and 11b of the first shaft 13 of the vehicle 10 and the right wheel 12a of the second shaft 14 of the vehicle 10 are placed on the platform 20 in the full length direction. The force acting on the stage 20 when viewed from the (front-rear direction) is shown. Further, in FIG. 10C, the platform when both wheels 11 a and 11 b of the first shaft 13 of the vehicle 10 and both wheels 12 a and 12 b of the second shaft 14 of the vehicle 10 are on the platform 20. The force which acts on the mounting base 20 when 20 is seen from the full length direction (front-back direction) is shown.

In this case, as can be understood from the above description, the difference between P ₁₂ (t) in the time interval [t ₅ , t ₆ ] and P ₁₂ (t) in the time interval [t ₇ , t ₈ ] is It is thought that it is caused only by the action of heavy _WL2 .

Therefore, from the equation of the third load cell LC3 moment balance that (fourth load cell LC4) relative to the distance b ₂ may be expressed by the following equation (11), the distance b ₂ based on the equation Can be calculated.

b ₂ = b−ΔP ₁₂ (t) · b / W _L2 (11)
Here, ΔP ₁₂ (t) is calculated from the value of P ₁₂ (t) (= P ₁ (t) + P ₂ (t)) in the time interval [t ₇ , t ₈ ] to the time interval [t ₅ , t ₆ ]. Is a value obtained by subtracting the value of P ₁₂ (t) (= P ₁ (t) + P ₂ (t)).

Here, since the geometric relationship of the following equation (12) is established between the tread interval B ₂ and the distances b, b ₂ , b ₂ ′, the distance b, which is a known value, and the above equation ( The tread interval B ₂ can be calculated by substituting the distances b ₂ and b ₂ ′ obtained from 10) and Equation (11) into Equation (12), respectively.

B ₂ = b− (b ₂ + b ₂ ′) (12)
As described above, in the new track scale 100 of this embodiment, the tread intervals B ₁ and B ₂ can be calculated. As a result, the center-of-gravity position calculation unit 52 of the new truck scale 100 has the tread intervals B ₁ , B ₂ , wheel loads W _R1 , W _L1 , W _R2 , W _L2 , and axle loads W ₁ , W ₂ of the vehicle 10. Based on the acquisition, the coordinate Y _G of the center of gravity G of the vehicle 10 can be calculated using Equation (5).

<Derivation method of coordinate _{X G>}
As shown in FIG. 9, the coordinate X _G represents the position of the center of gravity of the vehicle overall length direction in the orthogonal coordinate system O-XY.

Here, the Y axis in FIG. 9 is set on a straight line obtained by projecting the center line of the first axis 13 of the vehicle 10 onto the surface (front surface) of the mounting body 21. In general, since the center of gravity G exists on the left side of the Y axis (in the orthogonal coordinate system O-XY, one of the second quadrant and the third quadrant), the coordinate X _{G of the} center of gravity _G is usually negative. Take the value.

  Here, as shown in FIG. 11, both the wheels 11a, 11b of the first shaft 13 and the wheels 12a, 12b of the second shaft 14 of the vehicle 10 are mounted on the mount 20, Consider the balance of the force (load force based on the axial load and reaction force from the load cell) acting on the platform 20 when viewed from the width direction (left-right direction).

Then, the coordinates X _G from the equation the moment balance can be expressed by the following equation (13).

X _G = −W ₂ · l ₁₂ / (W ₁ + W ₂ ) (13)
In Expression (13), W ₁ and W ₂ are the axial weights of the first shaft 13 and the second shaft 14 of the vehicle 10, respectively. Therefore, if the inter-axis distance l ₁₂ of the vehicle 10 can be derived, the coordinate X _G can be calculated based on the same equation.

Note that the state of FIG. 11 in which the relationship of Expression (13) is obtained is a state in which the axle loads W ₁ and W ₂ of the vehicle 10 are acting on the platform 20, that is, in the time interval [t ₇ , t ₈ ]. Is the state of time. In this state, the vehicle 10 may be stationary on the mounting table 20 or may move on the mounting table 20.

  When the calculation of the gravity center position calculation unit 52 is performed in a state where the vehicle 10 is stationary on the platform 10, the transmission of vibration from the vehicle 10 to the load cells LC1 to LC4 is suppressed. The calculation accuracy can be improved.

  On the contrary, when the calculation of the gravity center position calculation unit 52 is performed in a state where the vehicle 10 is moved on the mounting table 20, the calculation of the gravity center position calculation unit 52 can be efficiently performed.

To guide the axial distance _{l 12} Determination of the vehicle 10 in the axial distance _{l 12} the meaning of folding point of the output waveform of the load cell LC1 to LC4 (time waveform) when the vehicle 10 moves the platform 20 on I need to know.

  First, the breakpoints of the output waveforms of the load cells LC1 to LC4 will be described.

  FIG. 12 is a diagram showing an output waveform (time waveform) of the load cell when both wheels of the first shaft of the vehicle of FIG. 1 get on the platform.

Specifically, in FIG. 12A, the x-axis of the orthogonal coordinate system o-xy (here, the position of the first axis 13 on the x-axis) is taken on the horizontal axis, and the output of all the load cells LC1 to LC4 is shown. The output waveform of the sum P (x) (= P ₁ (x) + P ₂ (x) + P ₃ (x) + P ₄ (x)) is taken on the vertical axis, and the relationship between the two is illustrated. In FIG. 12B, the x-axis of the orthogonal coordinate system o-xy (here, the position on the x-axis of the first axis 13) is taken on the horizontal axis, and the outputs of the first load cell LC1 and the third load cell LC3 are shown. The output waveform of the sum P ₁₃ (x) (= P ₁ (x) + P ₃ (x)) is plotted on the vertical axis, and the relationship between the two is shown.

  Furthermore, in FIG. 12, the first axis 13 of the vehicle 10 (however, the center line of the first axis 13 is associated with the position of the x axis in order to facilitate understanding of the meaning of the breakpoints of these output waveforms. Only) and how the wheels 11a and 11b move on the platform 20 are also shown.

  First, the break point of the output waveform of P (x) will be described.

As shown in FIG. 12 (a), when the tire of the right wheel 11a of the first shaft 13 starts to get on the mounting protrusion 22 (time t ₀ ), the output waveform of P (x) starts to rise, When the tire of the right wheel 11a of the shaft 13 is completely placed on the mounting protrusion 22 (time t ₀ ; x-axis = x ₁ ), the value of the output waveform is constant. In this case, the output value of P (x) corresponds to the wheel load W _R1 . At this time, the tire ground contact surface 30 is generated between the tire of the right wheel 11 a of the first shaft 13 of the vehicle 10 and the mounting 20, but the wheel load of the right wheel 11 a is applied to the tire ground contact surface 30 as an equally distributed load. Assuming that it works, the rising profile of the output waveform is almost linear as shown in FIG. Further, the distance between the x-axis position corresponding to the time t ₀ and the x-axis position (x ₁ ) corresponding to the time t ₁ is equal to the tire contact length S as shown in FIG. Become.

Next, as shown in FIG. 12A, when the tire of the left wheel 11b of the first shaft 13 starts to get on the mounting body 21 (time t ₂ ), the output waveform of P (x) starts to rise again. When the tire of the right wheel 11a of the first shaft 13 is completely placed on the mounting protrusion 22 (time t ₃ ; x-axis = x ₂ ), the value of the output waveform is constant. In this case, the output value of P (x) corresponds to the axial load W ₁ (= W _R1 + W _L1 ). At this time, the tire contact surface 30 between the tire and the platform 20 of the left wheel 11b of the first shaft 13 of the vehicle 10 but occurs uniformly distributed wheel load _{W L1} of the left wheel 11b is to the tire ground contact surface 30 Assuming that it acts as a load, the rising profile of the output waveform is almost linear as shown in FIG. Further, the distance between the x-axis position corresponding to time t ₂ and the x-axis position (x ₂ ) corresponding to time t ₃ is equal to the tire ground contact length S, as shown in FIG. Become.

Next, the break point of the output waveform of P ₁₃ (x) will be described.

As shown in FIG. 12 (b), when the tire of the right wheel 11a of the first shaft 13 starts to get into the mounting protrusion 22 (time t ₀ ), the output waveform of P ₁₃ (x) starts to rise, When the tire of the right wheel 11a of the single shaft 13 is completely placed on the mounting protrusion 22 (time t ₀ ; x-axis = x ₁ ), the value of the output waveform becomes the maximum. Thereafter, the output value of P ₁₃ (x) turns to linear decrease.

Here, the contribution K _R1 of the wheel load W _R1 to P ₁₃ (x) (see the dotted line in FIG. 12B) is such that the first axis 13 is on the x-axis of the third load cell LC3 (first load cell LC1). (when x-axis = _{x 3)} when it reaches, equal to the wheel load _{W R1.} The contribution K _R1 becomes zero when the first axis 13 reaches the x axis of the fourth load cell LC4 (second load cell LC2) (when x axis = x ₄ ).

Next, as shown in FIG. 12B, when the tire of the left wheel 11b of the first shaft 13 starts to get on the mounting body 21 (time t ₂ ), the output waveform of P (x) starts to rise again. When the tire of the right wheel 11a of the first shaft 13 is completely placed on the mount protrusion 22 (time t ₃ ; x-axis = x ₂ ), the value of the output waveform becomes the maximum. Thereafter, the output value of P ₁₃ (x) turns to linear decrease.

Here, the contribution K _L1 of the wheel load W _L1 to P ₁₃ (x) (see the dotted line in FIG. 12B) is such that the first axis 13 is on the x-axis of the third load cell LC3 (first load cell LC1). (when x-axis = _{x 3)} when it reaches, equal to the wheel load _{W L1.} The contribution K _L1 becomes zero when the first axis 13 reaches the x axis of the fourth load cell LC4 (second load cell LC2) (when x axis = x ₄ ). On the other hand, the output value of P ₁₃ (x) (see the solid line in FIG. 12B) is when the first axis 13 reaches the x axis of the third load cell LC3 (first load cell LC1) (x axis = when x _3), equal to the axle load _{W 1.} Further, the output values (when the x-axis = _{x 4)} when the first shaft 13 has reached on the x-axis of the fourth load cell LC4 (second load cell LC2), becomes zero.

The output waveform of P ₁₃ (x) (change in each profile) can be easily understood based on the moment balance equation based on the fourth load cell LC4 (second load cell LC2). Detailed description of the formula is omitted).

  FIG. 13 is a diagram showing an output waveform (time waveform) of the load cell when both wheels of the first shaft and both wheels of the second shaft of the vehicle of FIG. 1 get on the platform.

The profile of the output waveform of P (x) in FIG. 13A can be easily understood by referring to the description of the profile of the output waveform of P (x) in FIG. The profile of the output waveform of P ₁₃ (x) in FIG. 13B can be easily understood by referring to the description of the profile of the output waveform of P ₁₃ (x) in FIG. Therefore, detailed description thereof is omitted here.

Further, the position on the x-axis corresponding to the time when the tire of the left wheel 11b of the first shaft 13 is completely placed on the mounting body 21 (time t ₃ ), and the tire of the left wheel 12b of the second shaft 14 are The distance from the position on the x-axis corresponding to the time when it is completely placed on the mounting body 21 (time t ₇ ) is equal to the inter-axis distance l ₁₂ as shown in FIG.

Further, as shown in FIG. 13B, the position of the left wheel 11b of the first shaft 13 on the x-axis corresponding to the time when the tire is completely placed on the mounting body 21 (time t ₃ ), The distance between the position of the four load cells LC4 (second load cell LC2) on the x-axis is the distance (L ₀ ) between the rear end portion 21B of the mounting body 21 and the center of the first load cell LC1 (third load cell LC3). ) And the tire ground contact length S, and can be expressed as a dimension (a + L ₀ −S / 2) by the geometric relationship of the mounting table 20.

The tire of the right wheel 12a of the second shaft 14, the position on the x axis corresponding to the time to start boarded the platform protruding portion 22 (time _{t 4),} the tire of the left wheel 12b of the second shaft 14, The distance between the position on the x-axis corresponding to the time when it is completely placed on the pedestal main body 21 (time t ₇ ) uses the protrusion dimension (L ₁ ) of the pedestal protrusion 22 and the tire contact length S. The dimension (L ₁ + S) can be represented by the geometric relationship of the mounting table 20.

Further, the position on the x-axis corresponding to the time when the tire of the left wheel 12b of the second shaft 14 is completely mounted on the mounting body 21 (time t ₇ ) and the fourth load cell LC4 (second load cell LC2). the distance between the position on the x-axis may be from the size _{(a + L 0 -S / 2} ) by subtracting a dimension _{(l 12),} expressed as the dimension _{(a + L 0 -S / 2} -l 12).

Further, the position on the x-axis corresponding to the time when the tire of the right wheel 12a of the second shaft 14 starts to get on the mounting protrusion 22 (time t ₄ ), and the x of the fourth load cell LC4 (second load cell LC2). The distance to the position on the axis is expressed as a dimension (a + L ₀ + L ₁ + S / 2−l ₁₂ ) by adding the dimension (L ₁ + S) to the dimension (a + L ₀ −S / 2−l ₁₂ ). be able to.

As described above, the inter-axis distance l ₁₂ of the vehicle 10 can be derived as follows based on the geometrical relationship of FIG.

First, attention is paid to a right triangle whose vertex is the coordinate position 200, 201, 202 on FIG. 13B and a right triangle whose vertex is the coordinate position 205, 206, 202 on FIG.
Then, the following relational expression (14) is obtained using the similarity relation between these right triangles.
W ^* / (a + L ₀ −S / 2) = W ^** / (a + L ₁ + L ₀ + S / 2−12 ₁₂ )
(14)
Therefore, when the equation (14) is transformed, the inter-axis distance l ₁₂ can be expressed as the following equation (15).
l ₁₂ = a + L ₀ + L ₁ + S / 2−W ^** / (a + L ₀ −S / 2) / W ^*
... (15)
In the equation (15), the distances a, L ₀ , and L ₁ are known values. Further, each of W ^* and W ^** can be derived as an extreme value of P ₁₃ as shown in FIG. 13B, and these values are also known. Therefore, by knowing the value of the tire ground contact length S, the inter-axis distance l ₁₂ can be derived.

  Therefore, attention is paid to a right triangle whose vertex is the coordinate position 203, 204, 202 on FIG. 13B and a right triangle whose vertex is the coordinate position 205, 206, 202 on FIG.

  Then, the following relational expression (16) is obtained by using the similarity relation between these right triangles.

W ^* / (a + L ₀ −S / 2) = W ₁ / a (16)
Therefore, when the equation (16) is modified, the tire contact length S can be expressed as the following equation (17).

S = a + L ₀ −W ^* · a / W ₁ (17)
In the equation (15), the distances a and L ₀ are known values. W ₁ is the axial load of the first shaft 13 of the vehicle 10.

Thus, by substituting the distances a, L ₀ , L ₁ , W ^* , W ^** and the distance S obtained from the above equation (17) into the equation (15), which are known values, respectively. The inter-axis distance l ₁₂ can be calculated.

As described above, the new track scale 100 of the present embodiment can calculate the inter-axis distance l ₁₂ . As a result, the center-of-gravity position calculation unit 52 of the new truck scale 100 calculates the center of gravity G of the vehicle 10 using Expression (13) based on the acquisition of the inter-axis distance l ₁₂ and the axial weights W ₁ and W ₂ of the vehicle 10. it can be calculated coordinate Y _G.

[Function of total weight calculation unit]
Hereinafter, the function of the total weight calculator 53 of the new truck scale 100 will be described.

  The total weight W of the vehicle 10 can be derived from the following equation (18).

W = P (t) (= P ₁ (t) + P ₂ (t) + P ₃ (t) + P ₄ (t))
... (18)
In Expression (18), t is the time within the time interval [t ₇ , t ₈ ].

  As described above, in the new truck scale 100 of the present embodiment, the total weight calculation unit 53 can calculate the total weight W of the vehicle 10 using Expression (18).

[Function of axle load calculation unit]
Hereinafter, the function of the axial load calculation unit 54 of the new track scale 100 will be described.

The axial weight W ₁ of the first shaft 13 of the vehicle 10 can be derived from the following equation (19).

W ₁ = P (t) (= P ₁ (t) + P ₂ (t) + P ₃ (t) + P ₄ (t))
... (19)
In equation (19), t is the time within the time interval [t ₃ , t ₄ ].

Axle weight _{W 2} of the second shaft 14 of the vehicle 10 can be derived by the following equation (20).

W ₂ = P (t) (= P ₁ (t) + P ₂ (t) + P ₃ (t) + P ₄ (t)) − W ₁
... (20)
In Equation (20), t is the time within the time interval [t ₇ , t ₈ ].

As described above, in the new truck scale 100 of the present embodiment, the axle load calculator 54 uses the expressions (19) and (20) to determine the axle load W ₁ of the first axis 13 and the second axis 14 of the vehicle 10. it can be calculated axle load W _2.

(Second Embodiment)
[Configuration of new track scale]
FIG. 14 is a diagram showing an example of a schematic structure of a new track scale according to the second embodiment of the present invention. FIG. 2A shows a plan view of the new track scale. FIG. 4B shows a side view of the new track scale.

  In the present embodiment, for convenience, in FIG. 14, the full length direction of the vehicle 10 is illustrated as “front” and “rear” directions, and the width direction of the vehicle 10 is illustrated as “left” and “right” directions. Yes. Then, the configuration of the following new truck scale 200 will be described assuming that the vehicle 10 enters from “rear” of the platform 20 and exits from “front” of the platform 20.

  FIG. 15 is a functional block diagram of the new track scale control device of FIG.

  In the new track scale 200 of the present embodiment, a predetermined program is executed by the computing unit 49 (see FIG. 2) in the control device 40A, so that the wheels 11a, 11b, 12a, A wheel weight calculation unit 51 for calculating the wheel weight of 12b, a gravity center position calculation unit 52 for calculating the horizontal center of gravity position of the vehicle 10, a total weight calculation unit 53 for calculating the total weight of the vehicle 10, and the axles 13 and 14 of the vehicle 10 In addition to the functions of the axle load calculator 54 and the display signal generator 55 for calculating the axle load of the vehicle 10, the tire pressure calculator 56 for predicting the tire air pressure of the left and right wheels 11 a, 11 b, 12 a, 12 b of the vehicle 10. This function is also realized.

  That is, the new track scale 200 of the present embodiment has such a function that the function of the tire air pressure calculation unit 56 can be realized by executing a predetermined program by the calculator 49 in the control device 40A. Although not distinguished from the new track scale 100 of the first embodiment (see FIG. 1), the components of the new track scale 100 can be used as they are on the hardware.

  Therefore, here, the same reference numerals are given to the components of the new track scale 200 of the present embodiment that are the same as or equivalent to the components of the new track scale 100 of the first embodiment, and the details of the configuration common to both are given. The detailed explanation is omitted.

  Note that the control device 40A does not necessarily have to be composed of a single computing unit 49 (see FIG. 2), and a plurality of computing units are distributed and cooperate to perform the operation of the new track scale. It may be configured to control. For example, the function of the tire pressure calculation unit 56 described below, the function of the wheel load calculation unit 51 described in the first embodiment, the function of the center of gravity position calculation unit 52, the function of the total weight calculation unit 53, and the axle load calculation unit Each of the 54 functions has its own value. Therefore, only the function of the tire air pressure calculation unit 56 is realized by using an arithmetic unit specialized for realizing the function of the tire air pressure calculation unit 56 so that the tire air pressure of the wheels 11a, 11b, 12a, 12b of the vehicle 10 can be predicted. A new track scale may be built.

The functions of the wheel load calculator 51, the center of gravity position calculator 52, the total weight calculator 53, and the axle load calculator 54 are the same as those described in the first embodiment. Further, the meanings of symbols used in the following description and related drawings are the same as those described in the first embodiment except for the tire contact lengths S _R1 , S _L1 , S _R2 , S _L2, and t _f below. The same. Further, the function of the display signal generation unit 55 is known. Therefore, detailed description thereof will be omitted here.

[Definition of symbols]
First, the meanings of symbols used in the following description and related drawings are defined.

<Vehicle related (for example, refer to FIG. 16)>
S _R1 : Tire contact length of the right wheel 11a of the first shaft 13 S _L1 : Tire contact length of the left wheel 11b of the first shaft 13 S _R2 : Tire contact length of the right wheel 12a of the second shaft 14 S _L2 : Second Tire contact length t _f of the left wheel 12b of the shaft 14: When the output of P (t) starts to decrease

[Function of tire pressure calculation unit]
Hereinafter, the function of the tire air pressure calculation unit 56 of the new truck scale 200 will be described.

The tire ground contact lengths S _R1 , S _L1 , S _R2 , S _L2 of the left and right wheels 11a, 11b, 12a, 12b of the vehicle 10 depend on the corresponding air pressure and wheel load W _R1 , W _L1 , W _R2 , W _L2. Change. Therefore, if such tire ground contact lengths S _R1 , S _L1 , S _R2 , S _L2 and wheel weights W _R1 , W _L1 , W _R2 , W _L2 can be calculated, wheels 11a, 11b are based on these values. , 12a, 12b should be able to predict the excess or deficiency of the tire pressure.

That is, when the tire pressure is low, or when the wheel loads W _R1 , W _L1 , W _R2 , and W _L2 are large, the tire contact lengths S _R1 , S _L1 , S _R2 , and S _L2 become long. Conversely, when the air pressure is high, or when the wheel loads W _R1 , W _L1 , W _R2 , and W _L2 are small, the tire contact lengths S _R1 , S _L1 , S _R2 , and S _L2 are shortened. If the vehicle 10 travels in a state where the tire air pressure is low, a tire trouble (for example, a tire burst during traveling) of the vehicle 10 occurs. Therefore, knowing the tire air pressure of the vehicle 10 is important for driving the vehicle 10.

The calculation method of the vehicle wheel weights W _R1 , W _L1 , W _R2 , and W _L2 by the new truck scale 200 can be understood by referring to the contents described in the first embodiment.

Therefore, hereinafter, a method of calculating the tire contact lengths S _R1 , S _L1 , S _R2 , and S _L2 for each of the left and right wheels 11a, 11b, 12a, and 12b of the vehicle 10 will be described.

<Derivation method of vehicle tire ground contact length>
16 is a diagram showing an output waveform (time waveform) of the load cell when both wheels of the first shaft and both wheels of the second shaft of the vehicle of FIG. It is the schematic used for description of derivation | leading-out of the tire contact length of the vehicle by a calculating part.

  As shown in FIG. 12 (first embodiment), when the vehicle 10 gets into the new truck scale 200, the order in which the vehicle wheels 11a, 11b, 12a, and 12b get in is the right wheel 11a of the first shaft 13, The left wheel 11b of the first shaft 13, the right wheel 12a of the second shaft 14, and the left wheel 14b of the second shaft 14 are in this order. Therefore, the output waveforms (time waveforms) of the load cells LC1 to LC4 when both the wheels 11a and 11b of the first shaft 13 and the both wheels 12a and 12b of the second shaft 14 get on the mounting 20 are shown in FIG. It is expressed as follows.

Note that the profile of the output waveform of P (x) (= P ₁ (x) + P ₂ (x) + P ₃ (x) + P ₄ (x)) in FIG. 16 is P (x) in the first embodiment. This can be easily understood by referring to the explanation of the output waveform profile. Also, the profile of the output waveform of P ₁₃ (x) (= P ₁ (x) + P ₃ (x)) in FIG. 16 is the description of the profile of the output waveform of P ₁₃ (x) in the first embodiment. Can be easily understood by considering Therefore, detailed description thereof is omitted here.

Regarding the first shaft 13 of the vehicle 10, the tire ground contact lengths S _R1 and S _L1 of both wheels 11a and 11b of the first shaft 13 of the vehicle 10 can be formulated as follows.

First, a right triangle having apexes at coordinate positions 300, 301, and 302 in FIG. 16 specified when the time t is within the time interval [t ₁ , t ₂ ] (t ₁ <t <t ₂ ) This is similar to a right triangle having apexes at the coordinate positions 303, 304, and 305 in FIG.

Here, the distance between the position on the x-axis corresponding to the coordinate position 301 and the position on the x-axis corresponding to the coordinate position 302 is the protrusion dimension (L ₁ ) of the mounting protrusion 22 and the tire contact length. The dimension (L ₁ − (S _R1 + S _L1 ) / 2) can be expressed by the geometric relationship of the mounting table 20 using S _R1 and S _L1 .

Then, the following relational expression (21) is obtained by using the similarity relation between the above right triangles. When the expression (21) is transformed, it can be expressed as the following expression (22).
(P ₁₃ (t ₂ ) −P ₁₃ (t ₁ )) / ((L ₁ − (S _R1 + S _L1 ) / 2))
= -W _R1 / a
(21)
S _R1 + S _L1 = 2L ₁ +2 (P ₁₃ (t ₂ ) −P ₁₃ (t ₁ )) · a / W _R1
(22)
Next, a right triangle having apexes at the coordinate positions 306, 307, and 308 in FIG. 16 specified when the time t is in the time interval [t ₃ , t ₄ ] (t ₃ <t <t ₄ ) This is similar to a right triangle having apexes at coordinate positions 308, 304, and 305 in FIG.

Here, the distance between the position on the x-axis corresponding to the coordinate position 307 and the position on the x-axis corresponding to the coordinate position 308 is the total length (L) of the mounting body 21 and the tire ground contact length S _L1. And the center-to-center distance (a) between the first load cell LC1 (third load cell LC3) and the second load cell LC2 (fourth load cell LC4), the dimensions (( L-a) / 2-S _L1 / 2).

  Then, the following relational expression (23) is obtained using the similarity relation between the above right triangles. When the expression (23) is transformed, it can be expressed as the following expression (24).

(W ₁ −P ₁₃ (t ₃ )) / ((L−a) / 2−S _L1 / 2)
=-(W _R1 + W _L1 ) / a (23)
S _L1 = L + (1-2P ₁₃ (t ₃ ) / W ₁ ) · a (24)

Similar to the calculation method of the tire ground contact lengths S _R1 and S _{L1 on} the first shaft 13 for the second shaft 14 of the vehicle 10, the similarity of the right triangles is used as follows to determine the second shaft 14 of the vehicle 10. Formulation can be performed for the tire ground contact lengths S _R2 and S _L2 of both wheels 12a and 12b. However, details of derivation of the equations are omitted here.

First, when the time t is the time interval [t ₅ , t ₆ ] (t ₅ <t <t ₆ ), the following relational expression (25) is obtained using the similarity relation of the right triangle, and the expression (25) Can be expressed as the following equation (26).
(P ₁₃ (t ₆ ) −P ₁₃ (t ₅ )) / (L ₁ − (S _R2 + S _L2 ) / 2)
= − (W _R1 + W _R1 + W _R2 ) / a (25)
S _R2 + S _L2 = 2L ₁ +2 (P ₁₃ (t ₆ ) −P ₁₃ (t ₅ )) · a /
(W _R1 + W _R1 + W _R2 ) (26)
Next, when the time t is the time interval [t ₇ , t _f ] (t ₇ <t <t _f ), the following relational expression (27) is obtained using the similarity relation of the right triangle, and the expression (27) Can be expressed as the following equation (28).

(P ₁₃ (t _f ) −P ₁₃ (t ₇ )) / (L−l ₁₂ + (S _R2 −S _L2 −S _R1 ) /
2-VA) = − (W _R1 + W _R1 + W _R2 + W _L2 ) / a (27)
_{S R2 -S L2 = 2 (l} 12 -L) -2 (P 13 (t f) -P 13 (t 7)) · a /
(W _R1 + W _R1 + W _R2 + W _L2 ) + S _R1 + 2VA (28)
In Expression (27) and Expression (28), the variable VA corresponds to the longer of S _R1 / 2 and S _L1 / 2. In other _words, in the case of _{S R1 / 2> S L1 /} 2, a VA _{= S R1} / _2, in the case of _{S R1 / 2 <S L1 /} 2, is VA _{= S L1} / 2. If S _R1 / 2 and S _L1 / 2 are equal, S _R1 / 2 or S _L1 / 2 may be used for the variable VA.

In FIG. 16, for convenience, the variable VA is abbreviated as “S _R1 / 2 (orS _L1 / 2) (= VA)”.

  Hereinafter, the reason why such a variable VA is defined in Expression (27) and Expression (28) will be described with reference to FIG.

As shown in FIG. 16, the time t _f, corresponding to the time the output of the P (t) starts to decrease. Therefore, the time _{t f,} the left and right wheels 10a of the first shaft 13 of the vehicle 10, is one of the tire 10b Sashikakari the front end portion 21F of the platform body 21, as a result, the tire is new truck scale 200 Corresponds to the time of departure. When the tire ground contact lengths S _R1 and S _L1 of the tires of the wheels 10a and 10b are different, the tire having the longer tire ground contact length first reaches the front end portion 21F of the mounting body 21. Therefore, the distance (variable VA) between the position on the x-axis corresponding to the time t _f, the position on the x axis corresponding to the front end portion 21F of the platform body 21, the tire towards the tire contact length is long Dominated by.

  For this reason, the variable VA needs to be defined in the equations (27) and (28).

In this way, the tire ground contact lengths S _R1 , S _L1 , S _R2 , and S _L2 for each of the left and right wheels 11a, 11b, 12a, and 12b of the vehicle 10 are the above formula (22), formula (24), and formula, respectively. It can be determined using (26) and equation (28).

As described above, in the new track scale 200 of the present embodiment, the tire air pressure calculation unit 56 calculates the tire ground contact lengths S _R1 , S _L1 , S _R2 , S _L2 using the output waveforms (time waveforms) of the load cells LC1 to LC4. it can.

Further, as described in the first embodiment, in the new truck scale 200 of the present embodiment, the wheel load calculation unit 51 can calculate the wheel loads W _R1 , W _L1 , W _R2 , and W _L2 of the vehicle 10.

As a result, the tire air pressure calculation unit 56 of the new truck scale 100 determines the tire contact lengths S _R1 , S _L1 , S _R2 , S _L2 and the wheel weights W _R1 , W _L1 , W _R2 , W _L2 based on the acquisition. Excessive or insufficient air pressure of the tires of the wheels 11a, 11b, 12a, 12b can be predicted. As a result, the tire air pressure calculator 56 can determine whether the tire air pressure of each wheel 11a, 11b, 12a, 12b is good or bad.

For example, in such a determination, threshold values of the tire contact lengths S _R1 , S _L1 , S _R2 , and S _L2 for the wheel weights W _R1 , W _L1 , W _R2 , and W _L2 of the wheels 11a, 11b, 12a, and 12b are set in advance. In addition, based on the calculated values of the wheel weights W _R1 , W _L1 , W _R2 , W _{L2 and} the calculated values of the tire contact lengths S _R1 , S _L1 , S _R2 , S _L2 , the tire pressure is predicted to be excessive or insufficient. Also good.

Further, if the legal upper limit value of the wheel weights W _R1 , W _L1 , W _R2 , and W _L2 of the vehicle 10 is, for example, 5 tons, the tire contact lengths S _R1 , S _L1 , S _R2 , S in the tire of the vehicle 10 The upper limit value S1max (5 tons) of _L2 can be determined naturally. Therefore, when any of the tire contact lengths S _R1 , S _L1 , S _R2 , and S _L2 exceeds the upper limit value S1max (5 tons), the wheel weights W _R1 , W _L1 , W _R2 , and W _L2 are related. Alternatively, the tire pressure may be predicted to be abnormal (here, the tire pressure is insufficient).

Further, the upper limit values S2max (A inch), S2max (B inch),... Of the tire contact lengths S _R1 , S _L1 , S _R2 , S _L2 corresponding to the tire size of the vehicle 10 are stored in advance in the memory 48 as table data. By doing so, it is possible to predict a fine abnormality in tire pressure (here, insufficient tire pressure). For example, when any of the tire ground contact lengths S _R1 , S _L1 , S _R2 , and S _L2 exceeds the upper limit value S2max (A inch), the control device 40A uses appropriate notification means (not shown). A warning to the driver such as “If the installed tire size is A inch, it is considered that the tire air pressure is insufficient, so please adjust the tire air pressure” can be notified.

(Modification of the second embodiment)
In the new truck scale 200 of the second embodiment, the method of calculating the tire ground contact length for each of the left and right wheels 11a, 11b, 12a, 12b of the vehicle 10 has been described, but the present invention is not necessarily limited thereto.

For example, in the first embodiment, the tire contact length S is formulated (formula (17)) on the assumption that the tire contact length S is the same in all the wheels 11a, 11b, 12a, and 12b. . Therefore, even in this case, it may be useful to easily predict whether the tire pressure is excessive or insufficient. That is, the computing unit 49 of the new track scale 100 of the first embodiment uses the output waveforms (time waveforms) of the load cells LC1 to LC4, and the tire ground contact lengths of the left and right wheels 11a, 11b, 12a, 12b of the vehicle 10, respectively. The tire contact length S when S is assumed to be the same can be calculated. Therefore, the computing unit 49 of the new track scale 100 simply determines whether the tire pressures of the wheels 11a, 11b, 12a, 12b are good or bad based on the tire ground contact length S and the wheel loads W _R1 , W _L1 , W _R2 , W _L2. Can be judged.

(Modification of the first and second embodiments)
Next, modifications of the new track scales 100 and 200 of the first and second embodiments will be described. These new track scales 100 and 200 can be modified into various modifications as follows.

<First Modification>
In the new track scales 100 and 200 according to the first and second embodiments, an example (see FIG. 1) in which the mount protrusion 22 protrudes from the right half of the rear end 21B of the mount body 21 is shown. Not limited to.

  A mounting protrusion of the same type as the mounting protrusion 22 may be protruded from the left half of the rear end 21 </ b> B of the mounting body 21. Further, the same type of platform projection as the platform projection 22 may be projected from the left half or the right half of the front end 21 </ b> F of the platform main body 21.

  Furthermore, the truck scale may be configured so that the vehicle can enter from both the front and the rear. In this case, like the new track scale 100A (200A) in FIG. 17, the platform protrusions 22A and 22 are projected from both the front and rear end portions 21F and 21B of the platform body 21 of the platform 20A, respectively. A pair of lid members 26 and 26A for closing the groove space between the installation base 25A and the installation base 25A may be disposed.

<Second Modification>
In the new track scales 100 and 200 of the first and second embodiments, the four load cells LC1 to LC4 are arranged on the installation base 25 below the mounting base 20 at the four corners of the mounting main body 21, respectively. As described above, in such new track scales 100 and 200, there is a possibility that the strength of the mount protrusion 22 will be insufficient. This may be an obstacle to commercialization (commercialization) of the new truck scales 100 and 200.

  Therefore, in the new track scale 100B (200B) of the present modification, only the third load cell LC3 ′ of the four load cells LC1 to LC4 is moved backward as shown in FIG. 18 so as to cope with such a problem. By shifting in parallel, the platform protrusion 22 is supported from below by the third load cell LC3 ′ on the installation base 25. That is, the first load cell LC1, the second load cell LC2, and the fourth load cell LC4 are arranged to support the mounting body 21 from below at the corner of the mounting body 21, and the third load cell LC3 ′ protrudes from the mounting base. The mounting table protrusion 22 is arranged at an appropriate position of the portion 22 so as to support it from below.

  As described above, in the new track scale 100B (200B) of the present modification, the lack of strength of the mounting protrusion 22 can be appropriately compensated for by the support to the mounting protrusion 22 using the third load cell LC3 '.

  And in the new track scale 100B (200B) of this modification, the various functions described in the first and second embodiments are formulated using the arithmetic expressions listed in the first and second embodiments. Can do.

However, in this case, instead of P ₁₃ (x) (= P ₁ (x) + P ₃ (x)), which is the sum of outputs of the first load cell LC1 and the third load cell LC3 ′, P in the following equation (29) ₁₃ ′ (x) must be used. Here, details of derivation of Equation (29) are omitted.

P ₁₃ ′ (x) = P ₁ (x) + (1 / 2−x / a) · P ₃ (x)
... (29)
In Expression (29), a is the center-to-center distance between the first load cell LC1 and the second load cell LC2.

<Third Modification>
In the new track scales 100 and 200 of the first and second embodiments, the four load cells LC1 to LC4 are arranged on the installation base 25 below the mounting base 20 at the four corners of the mounting main body 21, respectively. As described above, in the new track scales 100 and 200, there is a possibility that the strength of the mount protrusion 22 is insufficient. This may be an obstacle to commercialization (commercialization) of the new truck scales 100 and 200.

  Therefore, in the new track scale 100C (200C) of the present modified example, the mounting base 20C protrudes from the right side of the rear end portion of the mounting main body 21 as shown in FIG. The 1st stand protrusion part 122 and the 2nd stand protrusion part 222 which protrudes from the left side are provided. The first load cell LC1 ″ is disposed so as to support the second mounting table protrusion 222 from below, and the third load cell LC3 ″ is disposed so as to support the first mounting table protrusion 122 from below.

  As described above, in the new track scale 100C (200C) of the present modified example, the strength of the first platform protrusion 122 is appropriately compensated for by the support to the first platform protrusion 122 using the third load cell LC3 ″. be able to.

  At this time, the first platform protrusion 122 is configured to be wider than the second platform protrusion 222, and, like the platform 22 of the new truck scales 100 and 200, either the left or right side of the vehicle 10. Only the wheels (here, the right wheels 11 a and 12 a) are set to a width dimension that allows the first platform protrusion 122 to ride on the wheels.

  On the other hand, the second platform protrusion 222 is configured to be narrower than the first platform protrusion 122, and either the left or right wheel of the vehicle 10 (here, the right wheels 11a and 12a) is the first. When riding on the mounting table protrusion 122, the width of the left or right wheel of the vehicle 10 (here, the left wheels 11 b and 12 b) is set to a width that does not ride on the second mounting table protrusion 222.

  That is, when one of the left and right wheels of the vehicle 10 (here, the right wheels 11a and 12a) rides on the first mounting protrusion 122, the left and right wheels of the vehicle 10 (here, the left wheel 11b). , 12b) passes through the rectangular notch 500 (that is, on the lid member 26C) of the platform 20C between the first platform projection 122 and the second platform projection 222.

  In this case, in order to prevent the vehicle 10 from accidentally entering the second platform protrusion 222 from the rear, the vehicle 10 enters the second platform projection 222 near the second platform projection 222. A blocking means 400 (for example, a pole or a guide plate) may be disposed.

  Further, in the new track scale 100C (200C) of this modification, as shown in FIG. 19, the four load cells LC1 ″ to LC4 ″ are respectively located on the installation base 25 below the mounting table 20C at the four corners of the mounting table 20C. It is arranged in.

  Specifically, the first load cell LC1 ″ and the third load cell LC3 ″ are arranged at a constant interval (dimension b ″) on a straight line parallel to the rear end portion in the vicinity of the rear end portion of the mounting table 20C. The LC2 ″ and the fourth load cell LC4 ″ are arranged in the vicinity of the front end portion of the mounting table 20C on the straight line parallel to the front end portion 21F with the same interval (dimension b ″) as the above-described fixed interval.

  On the other hand, the first load cell LC1 ″ and the second load cell LC2 ″ are arranged at a certain interval (dimension a ″) on a straight line parallel to the left end portion in the vicinity of the left end portion of the mounting table 20C, and the third load cell LC3 ″. The fourth load cells LC4 ″ are arranged on the straight line parallel to the right end portion in the vicinity of the right end portion of the mounting table 20C with the same interval (dimension a ″) as the above-described fixed interval.

  Therefore, in the new track scale 100C (200C) of this modification, the dimension a in the arithmetic expressions listed in the first and second embodiments is replaced with the dimension a ", and the dimension b in the arithmetic expression is replaced with the dimension b". By replacing them, it is possible to formulate various functions described in the first and second embodiments using these arithmetic expressions as they are.

<Fourth Modification>
In the new truck scales 100 and 200 according to the first and second embodiments, it is assumed that only the right wheels 11a and 12a of the vehicle 10 are on the platform protrusion 22, but this is not restrictive.

  For example, in the new truck scale 100D (200D) of this modified example, as shown in FIG. 20, only the right wheel 11a, 12a of the vehicle 10 protrudes from the right side of the rear end portion of the mounting body 21. While being able to get on the protruding part 322, only the left wheels 11 b and 12 b of the vehicle 10 can get on the second mounting protrusion part 422 protruding from the left side of the rear end part of the mounting body 21.

  Here, as shown in FIG. 20, the width of the first mounting protrusion 322, the width of the second mounting protrusion 422, and the distance between the first mounting protrusion 322 and the second mounting protrusion 422. The width of the rectangular cutout portion 501 of the mounting table 20D is set to substantially the same dimension.

  That is, when the right wheels 11a and 12a of the vehicle 10 ride on the first platform protrusion 322, the left wheels 11b and 12b of the vehicle 10 do not ride on the second platform protrusion 422, and the first platform protrusion. It passes through the rectangular cutout 501 (that is, on the lid member 26D) of the mounting 20D between the portion 322 and the second mounting protrusion 422. On the contrary, when the left wheels 11b and 12b of the vehicle 10 ride on the second mounting protrusion 422, the right wheels 11a and 12a of the vehicle 10 do not ride on the first mounting protrusion 322 and It passes through the notch 501 (that is, on the lid member 26D) of the mounting table 20D between the protruding portion 322 and the second mounting table protruding portion 422.

  As in the third modification, the load cells LC1 ′ ″ to LC4 ′ ″ are arranged on the installation base 25 below the mounting table 20D at the four corners of the mounting table 20D.

  Therefore, various functions described in the first and second embodiments can be formulated using the arithmetic expressions listed in the first and second embodiments as they are.

  As described above, in the new truck scale 100D (200D) of the present modified example, the right wheel 11a, 12a and the left wheel 11b of the vehicle 10 no matter what position the vehicle 10 enters from the rear side of the mounting 20D. , 12b can be placed on the mounting table 20D at different timings.

<Fifth Modification>
In the first and second embodiments, a four-wheel truck is taken as an example of the vehicle 10, and each of the wheel load calculation unit 51, the gravity center position calculation unit 52, the total weight calculation unit 53, and the axle load calculation unit 54 of the new truck scale 100 And the function of the tire air pressure calculation unit 56 of the new truck scale 200 have been described.

  However, the technology described in the present specification can be applied even to a vehicle having six or more wheels (for example, a trailer). In this case, formulation of the functions of the wheel load calculation unit 51, the center-of-gravity position calculation unit 52, the total weight calculation unit 53, the axle load calculation unit 54, and the tire pressure calculation unit 56 is described in the first and second embodiments. It can be easily understood by referring to the explanation. Therefore, detailed description thereof will be omitted.

<Sixth Modification>
In the new track scales 100 and 200 according to the first and second embodiments, an example (see FIG. 1) in which the mounting protrusion 22 protrudes from the right half of the rear end portion 21B of the mounting body 21 is shown. In such new track scales 100 and 200, there is a possibility that the strength of the mounting protrusion 22 is insufficient. This may be an obstacle to commercialization (commercialization) of the new truck scales 100 and 200.

  Therefore, in the new track scale mounting base 520 of the present modification, as shown in FIG. 21, the left half of the rear part of the mounting base 520 (that is, the area other than the mounting body 521), as shown in FIG. However, it is cut out so that the thickness of the mounting table 520 is about half. Then, a lid member 526 supported by the installation base 525 using an appropriate fixing means 527 is disposed so as to cover almost the entire cutout region. In other words, the lid member 526 is cut off at the connection with the mounting table 520, and even if the left wheels 11 b and 12 b of the vehicle 10 are placed on the lid member 526, the load of the vehicle 10 is transmitted to the mounting table 520. Absent.

  Further, as shown in FIG. 22, the four load cells LC <b> 1 to LC <b> 4 are respectively arranged on the installation base 525 below the mounting table 520 at the four corners of the mounting table 520.

  Specifically, the first load cell LC1 and the third load cell LC3 are arranged on the straight line parallel to the rear end portion 520B at a rear portion of the mounting table 520 with a predetermined interval (dimension b; see, for example, FIG. 6). The LC2 and the fourth load cell LC4 are arranged on the straight line parallel to the front end portion 520F at the front portion of the mounting table 520 at the same interval (dimension b; see, for example, FIG. 6).

  On the other hand, the first load cell LC1 and the second load cell LC2 are arranged at a constant interval (dimension a in FIG. 22) on the straight line parallel to the left end portion 520L in the vicinity of the left end portion 520L of the mounting table 520. The LC3 and the fourth load cell LC4 are arranged in the vicinity of the right end 520R of the mounting table 520 on the straight line parallel to the right end 520R with the same interval (dimension a in FIG. 22) as the above-mentioned fixed interval.

  From the above, the mounting table 520 is supported from below by the load cells LC1 to LC4 on the installation base 525.

  That is, the new truck scale of the present modified example has a platform main body 521 on which both the left and right wheels 11a, 11b, 12a, 12b (see FIG. 1) of the vehicle 10 can ride, as shown in FIGS. The platform 10 is composed of a platform projection 522 that projects from the rear end 521B of the platform body 521 so that only one of the left and right wheels (here, the right wheels 11a and 12a) of the vehicle 10 can ride. 520 and load cells LC1 to LC4 that support the mounting table 520 from below.

  With this configuration, in the new track scale of the present modification, the rigidity of the rear portion of the mounting table 520 can be increased, so that the strength of the mounting protrusion 522 can be improved.

  In the new track scale of the present modification, various functions described in the first and second embodiments can be formulated using the arithmetic expressions listed in the first and second embodiments.

However, in this case, the wheels 11a of the vehicle 10, 11b, 12a, the arithmetic expression of the tire contact length S of 12b change as the following equation (30), the following arithmetic expressions of the axis-to-axis distance _{l 12} of the vehicle 10 It is necessary to change as shown in equation (31).

<Tire ground contact length of vehicle>
When the vehicle 10 (see FIG. 1) gets on the new truck scale, the order of getting in the wheels 11a, 11b, 12a, 12b of the vehicle 10 is the right wheel 11a of the first shaft 13, the left wheel 11b of the first shaft 13, The order is the right wheel 12a of the two shafts 14 and the left wheel 14b of the second shaft 14. Therefore, the output waveforms (time waveforms) of the load cells LC1 to LC4 when the wheels 11a and 11b of the first shaft 13 and the wheels 12a and 12b of the second shaft 14 get on the mounting 20 are shown in FIG. It is expressed as follows.

Note that the profile of the output waveform of P (x) (= P ₁ (x) + P ₂ (x) + P ₃ (x) + P ₄ (x)) in FIG. 22 is the same as that in the first and second embodiments. It can be easily understood by referring to the explanation of the profile of the output waveform (x). Also, the profile of the output waveform of P ₁₃ (x) (= P ₁ (x) + P ₃ (x)) in FIG. 22 is the profile of the output waveform of P ₁₃ (x) in the first and second embodiments. It can be easily understood by referring to the explanation about. Therefore, detailed description thereof is omitted here.

  The tire ground contact length S of the wheels 11a, 11b, 12a, and 12b of the vehicle 10 can be formulated as follows using the output waveform of FIG. Here, the formulation of the tire contact length S when the tire contact length S of each of the left and right wheels 11a, 11b, 12a, and 12b of the vehicle 10 is assumed to be the same will be described.

The coordinate positions 500, 501, and 502 on P ₁₃ (x) in FIG. 22 specified when the time t is in the time interval [t ₁ , t ₂ ] (t ₁ <t <t ₂ ) The right-angled triangle is similar to the right-angled triangle having apexes at the coordinate positions 503, 504, and 505 at P ₁₃ (x) in FIG.

Then, the similarity between the above right triangles, each dimension on the x-axis in FIG. 22, the output value (W ^* , W ^** ) at the break point of P ₁₃ (x) in FIG. 22, and Using the output values (= W _R1 ) of the first and third load cells LC1 and LC3 of P ₁₃ (x) in FIG. 22, the tire contact length S can be expressed as the following equation (30). . Here, details of derivation of Equation (30) are omitted.

S = 2L ₁ + 2a · (W ^** − W ^* ) / W _R1 (30)
In the equation (30), a is the center-to-center distance between the first load cell LC1 (third load cell LC3) and a second load cell LC2 (fourth load cell LC4), projecting dimension of _{L 1} is the platform protrusion 522 (In other words, the notch dimension in the front-rear direction of the notch region of the mounting table 520).

<Vehicle distance between vehicles>
The inter-axis distance l ₁₂ of the vehicle 10 can be formulated as follows using the output waveform of FIG.

Attention is focused on the slope of the straight line 510 of P ₁₃ (x) in FIG. 22 specified when the time t is within the time interval [t ₃ , t ₄ ] (t ₃ <t <t ₄ ). Then, the slope of the straight line 510, the contribution to _P 13 (x) of the wheel load _{W R1} of the first axis 13 of the vehicle 10, _P 13 of the wheel load _{W L1} of the first axis 13 of the vehicle 10 (x) Is equal to the sum of the contribution to

Therefore, the above equation relation, each dimension on the x-axis in FIG. 22, and the output value (W ^* , W ^** , W ^*** , W ^* at the break point of P ₁₃ (x) in FIG. 22. ^*** ), the inter-axis distance l ₁₂ can be expressed as the following equation (31). Here, details of derivation of Equation (31) are omitted.
_{^{l 12 = L 1 +3/2 · S}} + (W *** -W ****) / (W R1 + W L1) · a
_{^{= 4L 1 + a · {(}} 3 (W ** -W *) / W R1 + (W *** -W ****) /
(W _R1 + W _R1 )} (31)
In the equation (31), a is the center-to-center distance between the first load cell LC1 (third load cell LC3) and a second load cell LC2 (fourth load cell LC4), projecting dimension of _{L 1} is the platform protrusion 522 (In other words, the notch dimension in the front-rear direction of the notch region of the mounting table 520).

  According to the track scale of the present invention, the function of measuring the wheel load and / or horizontal plane center of gravity of the vehicle and / or the function of determining whether the tire pressure is good can be added to the conventional track scale. Therefore, the present invention can be used for a track scale that can be used for measurement of vehicle wheel load, center of gravity position, etc., and determination of quality of tire air pressure.

DESCRIPTION OF SYMBOLS 10 Vehicle 11a Right wheel of front axle (first axis) 11b Left wheel of front axle (first axis) 12a Right wheel of rear axle (second axis) 12b Rear axle (second axis) Left wheel 13 Front axle (first axle)
14 Rear axle (second axle)
DESCRIPTION OF SYMBOLS 20 Mounting base 21 Mounting base body 22 Mounting protrusion 25 Installation base 26 Lid member 30 Tire grounding surface 40, 40A Control apparatus 41 Operation apparatus 42 Display apparatus 43 Amplifier 44 Low pass filter 45 Multiplexer 46 A / D converter 47 I / O Circuit 48 Memory 49 Calculator 51 Wheel load calculator 52 Center of gravity position calculator 53 Total weight calculator 54 Axle load calculator 55 Display signal generator 56 Tire pressure calculator LC1 First load cell LC2 Second load cell LC3 Third load cell LC4 First 4 load cell 100,200 track scale (new track scale)

Claims (16)

From the mounting body that can be loaded on both the left and right wheels of the vehicle, and the mounting protrusion that protrudes from the end of the mounting body so that only one of the left and right wheels of the vehicle can ride And
A plurality of load cells that support the table described above from below;
The first output signal from the load cell when only one of the left and right wheels of the vehicle is placed on the above-described stand protruding portion, and the load cell when both the left and right wheels of the vehicle are placed on the stand described above Computing means for computing the wheel weights of both the left and right wheels of the vehicle based on the second output signal from
Track scale with From the mounting body that can be loaded on both the left and right wheels of the vehicle, and the mounting protrusion that protrudes from the end of the mounting body so that only one of the left and right wheels of the vehicle can ride And
A plurality of load cells that support the table described above from below;
The first output signal from the load cell when only one of the left and right wheels of the vehicle is placed on the above-described stand protruding portion, and the load cell when both the left and right wheels of the vehicle are placed on the stand described above Computing means for computing a planar center of gravity position of the vehicle based on a second output signal from
Track scale with It said calculating means, truck scales according to claim 1 for calculating the tread distance of the vehicle using the first output signal and said second output signal and the wheel load.   The track scale according to claim 3, wherein the calculation means calculates a center-of-gravity position in the width direction of the vehicle using the wheel load, the axle load of the vehicle, and a tread interval of the vehicle. The track scale according to claim 1 or 2, wherein the calculation means calculates an inter-axis distance of the vehicle using time waveforms of the first output signal and the second output signal .   The track scale according to claim 5, wherein the calculation means calculates a center-of-gravity position in the full length direction of the vehicle using the inter-axis distance and the axle weight of the vehicle. Said calculating means according to claim 1 for calculating the tire contact length when the tire contact length of each of the left and right wheels of the vehicle using the time waveform of the first output signal and said second output signal is assumed to equal truck scale according to   The track scale according to claim 7, wherein the calculation unit determines whether or not the tire air pressure of the wheel is good based on the tire ground contact length.   The track scale according to claim 7, wherein the calculation means determines whether or not the tire air pressure of the wheel is good based on the tire ground contact length and the wheel load. From the mounting body that can be loaded on both the left and right wheels of the vehicle, and the mounting protrusion that protrudes from the end of the mounting body so that only one of the left and right wheels of the vehicle can ride And
A plurality of load cells that support the table described above from below;
The time waveform of the output signal from the load cell when only one of the left and right wheels of the vehicle is placed on the above-mentioned stand protruding portion, and the above when the both left and right wheels of the vehicle are placed on the above-mentioned stand A calculation means for calculating a tire ground contact length for each of the left and right wheels of the vehicle based on a time waveform of an output signal from a load cell;
Track scale with   The track scale according to claim 10, wherein the calculation means determines whether the tire air pressure for each wheel is good or not based on a tire ground contact length for each wheel.   The calculation means outputs the output signal from the load cell when only one of the left and right wheels of the vehicle is placed on the above-mentioned stand protruding portion, and when both the left and right wheels of the vehicle are placed on the above-mentioned stand. The wheel load of both the left and right wheels of the vehicle is calculated based on the output signal from the load cell, and the tire pressure for each wheel is determined to be good or bad based on the tire ground contact length for each wheel and the wheel load. The track scale according to claim 10.   The track scale according to any one of claims 1, 2, and 10, wherein the load cell is disposed below the base protrusion and the base body. The preceding table includes a first mounting table protruding portion and a second mounting table protruding portion protruding from an end portion of the above-described table main body,
The load cell is disposed below the first platform protrusion and the second platform protrusion,
When one of the left and right wheels of the vehicle rides on the first platform protrusion, the left and right wheels of the vehicle are between the first platform projection and the second platform projection. The track scale according to claim 13, wherein the track scale passes through a notch in the table.   The track scale according to claim 14, further comprising means for preventing the wheel from entering the second platform protrusion.   When either the left or right wheel of the vehicle rides on the second platform protrusion, the left or right wheel of the vehicle is between the first platform projection and the second platform projection. The track scale according to claim 14, wherein the track scale passes through a notch of the table.

Images