JP2002005730A - Load measuring device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load measuring device for vehicle capable of performing a stable load detection with a minimum measurement error. SOLUTION: A plurality of load sensors 3 is stuck to the side surface of a joist column 2 that is an intermediate member interposed between a vehicular frame 1 and a load-carrying platform. A load measurement is performed on the basis of the distortion detection from the load sensors 3. Since the load- distortion characteristics on the side surface of the joist column have a proportional relation, the load sensors 3 stuck to the side surface can stably detect the distortion according to the load. Since the joist column 2 is interposed between the frame 1 and the platform 4 and greatly influenced by a load such as the cargo put on the platform 4 or the like, a larger distortion can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load measuring device for a vehicle, and more particularly, to a load measuring device for a vehicle mainly used for a large vehicle having a loading platform and a joist column interposed between the loading platform and a vehicle body frame.

[0002]

2. Description of the Related Art Conventionally, load measurement has been performed on large vehicles such as trucks to prevent overloading. For load measurement, for example, a displacement sensor was sandwiched in a U-shaped frame to which a load was applied, and the total load was calculated using the displacement amount detected by this sensor. There is a problem that the measurement error increases due to the instability of the quantity. This problem is illustrated in FIGS.
This will be described with reference to FIG.

FIG. 3 is a schematic diagram showing an application example of this type of vehicle load measuring device. FIG. 4A is a schematic sectional view showing a conventional example. FIG. 4B is an explanatory diagram showing deformation of the frame of FIG. 4A due to a load. FIG. 4C is FIG.
6 is a graph showing load-ΔL characteristics of the frame of FIG.

In the schematic diagram of FIG. 3, a vehicle 10 is a large vehicle having a carrier such as a truck, for example. Vehicle 1
Numeral 0 constitutes a basic part of the vehicle body and has a frame 1 connected to wheels. The frame 1 generally has a U-shaped cross section for the purpose of workability or the pursuit of weight reduction and safety of the entire vehicle. In the case of a large vehicle, the frame 1 is configured in a ladder form to form a vehicle frame. . On the frame 1, a loading bed 4 is mounted via a so-called joist column 2, a column-shaped intermediate member having a hollow rectangular cross section. The frame 1 and the joist column 2 are fixed to each other via a fixing member such as a U-shaped bolt with a rubber sheet (not shown) interposed therebetween. A load is loaded on the loading platform 4, and a load based on the load is mainly measured.

[0005] The frame 1 is also connected to wheels, and is easily affected by a load on the vehicle 10, and is used as a load detection point. Since the frame 1 receives a force in the vertical direction according to the load, a load sensor 8 including a displacement sensor is mounted inside the frame 1 in order to utilize the amount of displacement of the frame for load detection.

[0006] The displacement amount corresponding to the load by the load sensor 8 is supplied to the amplifier 5 as shown by a dotted arrow. The amplifier 5 amplifies the amount of displacement from the load sensor 8 to a predetermined value and supplies it to the controller 6. The controller 6 receives the amplified displacement amount from the amplifier 5, performs an arithmetic process such as converting to a load value corresponding to the displacement amount, and supplies the load value to the display unit 7. Then, the display unit 7 displays the load value and notifies the driver or the loader of the load value.

Next, the frame 1 on which the load sensor 8 is mounted will be described with reference to FIGS. 4A and 4B show cross sections of the frame 1 and the joist column 2 described with reference to FIG.

As shown in the sectional view of FIG. 4A, the frame 1 and the joist columns 2 are connected to each other by a connecting member such as a U-shaped bolt (not shown) with a cushion member such as a rubber sheet 9 interposed therebetween. Connected and fixed. The frame 1 has a U-shaped cross section, and a displacement sensor 80 is fixed to an inner wall of an upper bottom surface and a lower bottom surface thereof via a mounting member 81.

The mounting member 81 includes a cylindrical portion 81A, a screw portion 81B extending from the cylindrical portion 81A and inserted into a mounting hole formed in a substantially central portion of a side surface of the frame 1, and a vertical direction from the cylindrical portion 81A. And an attachment part 81D extending in the horizontal direction. The mounting member 81 is fixed to the side surface of the frame 1 by inserting the screw portion 81B into the mounting hole on the side surface and tightening the nut 81C.

The load sensor 8 enclosed by a dotted line is configured to include two displacement sensors 80. Each of the angular displacement sensors 80 is fixed to the tip of the mounting portion 81D of the mounting member 81 by an adhesive, a screw, or the like. Each displacement sensor 80
Is, for example, a well-known differential transformer type displacement sensor,
Each is composed of a main unit 80A and a movable unit 80B. The main body portion 80A is fixed to the mounting portion 81D of the mounting member 81, and the movable portion 80B holds the U-shaped frame 1 when there is no load.
Are arranged so as to contact the inner walls of the upper bottom surface and the lower bottom surface.

With the above configuration, the displacement of the frame 1 under load is detected as the displacement of the movable portion 80B of the displacement sensor 80, and is output from the main body 80A.

By the way, in the explanatory diagram of FIG.
When no load is applied (before loading), the frame has a U-shape as indicated by a dotted line indicated by reference numeral 1. On the other hand, the frame shape under load (after loading) is indicated by reference numeral 1
As shown by the solid line indicated by A, it has a distorted U-shape. In addition, when no load is applied (before loading), the distance between the inner walls of the upper bottom surface and the lower bottom surface of the frame 1 is L, whereas when the load is applied (after loading), the distance is L1. That is, the distance between the inner walls is reduced by ΔL due to the loaded load.

FIG. 4C shows the relationship between ΔL and the load. As shown in FIG. 4 (C), Δ
L does not increase or decrease proportionally as indicated by a broken line, but increases and decreases irregularly as indicated by a solid line.

[0014]

As described above with reference to FIG. 3, in the conventional vehicle load measuring device, the load and the Δ
Since L is not a proportional relation but an irregular relation, if this is used to measure a load, a measurement error will increase. In other words, the frame often has a U-shaped cross section with a complicated shape for the purpose of workability or to reduce the weight of the whole vehicle and pursue safety, and the displacement between the inner walls of such a frame is affected by the load. As a result, there is a problem that when this is used for load measurement, a measurement error increases.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vehicle load measuring device capable of detecting a stable load with a small measurement error.

[0016]

According to the present invention, there is provided a load measuring apparatus for a vehicle, comprising:
(A) As shown in (A), a load measuring device for a vehicle including a load sensor 3 attached to a loaded member of a vehicle that generates distortion when a load is applied and detects the load based on the distortion of the loaded member. In the above, the loaded member is a column member having a hollow rectangular cross section having a side surface on which the amount of strain increases or decreases in proportion to the increase or decrease of the load, and the load sensor 3
Is attached to the side surface of the column member.

According to the first aspect of the present invention, the load sensor 3 is affixed to the side surface of a column member having a hollow rectangular cross section in which the amount of distortion increases and decreases in proportion to the increase and decrease of the load. And
The load sensor 3 detects a load based on the amount of distortion.
By attaching the load sensor 3 in this manner, a stable amount of strain with respect to the load can be obtained regularly.

According to a second aspect of the present invention, there is provided a load measuring apparatus for a vehicle, as shown in FIG. 1A. And a joist column 2 which is an intermediate member interposed between the frame 1 and the carrier 4 of the vehicle.

According to the second aspect of the present invention, the load sensor 3 is attached to the joist column 2 which is an intermediate member interposed between the frame 1 and the carrier 4 of the vehicle. Since the load-strain amount characteristics on the side surface of the joist column 2 are in a proportional relationship as shown in FIG. 1B, the load sensor 3 attached to this side surface can stably display the strain amount according to the load. Can be detected. In addition, joist column 2
Is interposed between the frame 1 and the bed 4 and is greatly affected by a load such as a load loaded on the bed 4, so that a larger strain can be detected.

According to a third aspect of the present invention, there is provided a load measuring device for a vehicle, as shown in FIGS. , A plurality of the load sensors 3 are attached, and the load is detected based on the detection output of each of the plurality of load sensors 3.

According to the third aspect of the present invention, a plurality of load sensors 3 are attached to the joist column 2. Then, the load is detected based on the detection output of each load sensor 3. Since a plurality of load sensors 3 are attached to the joist column 2 which is greatly affected by a load such as a load, more large strain data is obtained.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

First, an application example of the present invention will be described with reference to FIG. 3 again. In the schematic diagram of FIG. 3, reference numerals 1, 2, 4, and 10 are respectively a frame, a joist column,
It shows a bed and a vehicle, which are the same as those described above, and thus the description is omitted here. Here, the load sensor 8 including the displacement sensor attached to the frame 1 described above is used.
Instead, a load sensor 3 including a strain sensor is attached to the joist column 2. The joist column 2 is a columnar member having a rectangular cross section, and a plurality of load sensors 3 including a strain sensor are dispersedly mounted on a side surface thereof. These mounting locations are
It is based on the previously verified optimal distortion detection point.

The respective strain detection outputs from the plurality of load sensors 3 are supplied to an amplifier 5 as indicated by solid arrows. Here, the amplifier 5 amplifies the detection output from each load sensor 3 to a predetermined value and supplies it to the controller 6. Further, here, the controller 6 receives the amplified amounts of distortion from the amplifier 5, performs a predetermined calculation process such as a distortion-load conversion process, an addition process or an averaging process, calculates a load value, and displays the calculated load value. Supply to section 7. Then, the display unit 7 displays the load value and notifies the driver or the loader of the load value. Note that if the load sensor 3 includes an amplifier for amplifying the amount of detected distortion, the above-described amplifier 5 is not necessarily required.

According to the application example described above, the plurality of load sensors 3 are attached to the joist column 2 that is interposed between the frame 1 and the loading platform 4 and is greatly affected by the load such as the load loaded on the loading platform 4. Is done. Then, the load is detected based on the detection output of each load sensor 3. As described above, since the plurality of load sensors 3 are attached to the joist column 2 which is greatly affected by the load such as a load, more large strain data can be obtained. By using such data, extremely accurate load detection can be performed.

Next, the embodiment of the vehicle load measuring device of the present invention applied as described above will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 1A is a schematic sectional view showing an embodiment of the vehicle load measuring device of the present invention. Figure 1
(B) is an explanatory view showing deformation of the joist column of FIG. 1 (A) due to a load. FIG. 1C shows the load on the joist column shown in FIG. 1B.
It is a graph which shows a distortion amount characteristic. 1A and 1B show cross sections of the frame 1 and the joist column 2 described above.

As shown in the sectional view of FIG. 1A, the frame 1 and the joist columns 2 are connected to each other by a connecting member such as a U-shaped bolt (not shown) with a cushion member such as a rubber sheet 9 interposed therebetween. Connected and fixed. The frame 1 has a U-shaped cross section, and the joist column 2 has a hollow rectangular cross section. A load sensor 3 is attached to a side surface of the joist column 2, that is, a plane on which a strain amount changes with respect to a load.
Although described later with reference to FIG. 2, the load sensor 3 basically detects and outputs the amount of distortion via the fixing pieces 32A and 32B on the attachment surface.

By the way, in the explanatory diagram of FIG.
When no load is applied (before loading), the shape of the joist column has a U-shape as indicated by a dotted line indicated by reference numeral 2. On the other hand, when the load W is applied (after loading), the shape of the frame has a hollow rectangular cross-sectional shape in which both opposing side surfaces are both symmetrically distorted in an arcuate shape as indicated by a solid line indicated by reference numeral 2A. are doing.

FIG. 1C shows the relationship between the amount of strain on the side surface and the load.
Shown in As shown in FIG. 1 (C), the amount of strain increases and decreases as the load W increases and decreases as indicated by the solid line. Since the two sides are symmetrically opposed, both sides have the same characteristics.

According to the above-described embodiment, the joist column 2 which is an intermediate member interposed between the frame 1 of the vehicle and the bed 4 is provided.
The load sensor 3 is stuck on. The joist column 2 has a hollow rectangular cross section, that is, opposing symmetrical sides. Since the side surfaces are symmetric, the side surfaces are stably distorted by a load as shown in FIG. That is, the load-strain amount characteristic has a proportional relationship as shown in FIG. By attaching the load sensor 3 to the side surface of the joist column 2, the amount of distortion corresponding to the load is accurately detected, and as a result, the measurement error is small and the load can be detected with high accuracy. In addition, since the joist column 2 is interposed between the frame 1 and the loading platform 4 and is greatly affected by a load such as a load loaded on the loading platform 4, a larger strain can be detected. High load detection becomes possible.

Further, FIG. 2 and FIG.
The load sensor 3 used in the embodiment of FIG. FIG. 2 is an exploded perspective view illustrating an example of the load sensor 3 described above.

As shown in an exploded perspective view of FIG. 2, the load sensor 3 has a case 30, a circuit board 31, a base assembly 32, and supporting members 36A and 36B which form a rectangular parallelepiped outer shape.
Having.

On the base assembly 32, a sensing element 35 for detecting a distortion is mounted. The sensing element 35 is basically formed by forming a metal foil strain gauge on the surface of a long flat plate-shaped substrate made of a metal material such as stainless steel. The sensing element 35 performs strain detection using the fact that the resistance value of the metal foil strain gauge changes according to the load applied to the metal material substrate. The load applied to the metal material substrate is transmitted according to the amount of distortion of the bonding surface that is welded and fixed to the fixing pieces 32A and 32B integrally formed at the end of the base assembly 32. The base assembly 32 has two pin holes 32A and 32A.
B is provided, and ends of the support members 36A and 36B are inserted into the pin holes 32A and 32B, and are connected to the circuit board 31.

The circuit board 31 includes the support member 36A.
Holes 31A and 31B into which the ends of the first and second holes are inserted
Are provided, into which the ends of the support members 36A and 36B are inserted. An amplifier 18A for amplifying the output from the sensing element 35 is provided on the circuit board 31.
Etc. have been implemented.

The case 30 is mounted so as to cover the circuit board 31 and the base assembly 32 connected as described above. At the time of mounting, the fixing piece 53A of the base assembly 32 is inserted into the opening edge 30A, and the fixing piece 53B
Is inserted into the opening edge 30A of the other measurement surface (not shown). Further, a lead wire 34 for transmitting a load detection signal is electrically connected to the case 30 via a fixing bracket 33.

The load sensor 3 having such a configuration is used in the embodiment shown in FIG. 3 and FIG. 1A, but the present invention uses the load sensor 3 having the above configuration. The present invention is not limited to this, and a load sensor for detecting distortion of another configuration may be used instead. The position of the load sensor 3 is not limited to the joist column 2 as long as the column member is a column member in a vehicle having a hollow rectangular cross section having a side surface on which the amount of distortion increases or decreases in proportion to the increase or decrease of the load, such as the joist column 2. May be used.

[0037]

As described above, according to the first aspect of the present invention, the load sensor 3 has a side surface of a column member having a hollow rectangular cross section whose strain amount increases and decreases in proportion to an increase and decrease in load. It is pasted on. Then, the load sensor 3 detects a load based on the distortion amount. By attaching the load sensor 3 in this manner, a stable amount of strain with respect to the load can be obtained regularly. By utilizing such an amount of distortion, a highly accurate load detection with a small measurement error becomes possible.

According to the second aspect of the present invention, the load sensor 3 is attached to the joist column 2 which is an intermediate member interposed between the frame 1 and the carrier 4 of the vehicle. Since the load-strain amount characteristics on the side surface of the joist column 2 are in a proportional relationship as shown in FIG. 1B, the load sensor 3 attached to this side surface can stably display the strain amount according to the load. Can be detected. As a result, a highly accurate load detection with a small measurement error becomes possible. In addition, the joist column 2 is interposed between the frame 1 and the loading platform 4 and is greatly affected by a load such as a load loaded on the loading platform 4, so that a larger strain can be detected. As a result, it is possible to obtain an effect that more accurate load detection can be performed.

According to the third aspect of the present invention, a plurality of load sensors 3 are attached to the joist column 2. Then, the load is detected based on the detection output of each load sensor 3. As described above, since the plurality of load sensors 3 are attached to the joist column 2 which is greatly affected by the load such as a load, more large strain data can be obtained. By using such data, more accurate load detection can be performed.

[Brief description of the drawings]

FIG. 1A is a schematic sectional view showing an embodiment of a vehicle load measuring device according to the present invention. FIG. 1 (B) is FIG.
It is explanatory drawing which shows the deformation | transformation by the load of the joist column of (A).
FIG. 1C is a graph showing the load-strain amount characteristic of the joist column shown in FIG. 1B.

FIG. 2 is an exploded perspective view showing a load sensor used in the embodiment of FIG.

FIG. 3 is a schematic view showing an application example of the present invention and a conventional vehicle load measuring device.

FIG. 4A is a schematic sectional view showing a conventional example.
FIG. 4B is an explanatory diagram showing deformation of the frame of FIG. 4A due to a load. FIG. 4C is a graph showing a load-ΔL characteristic of the frame of FIG. 4B.

[Explanation of symbols]

 Reference Signs List 1 frame 2 joist column 3 load sensor 9 rubber sheet

Claims (3)

[Claims] 1. A load measuring device for a vehicle, comprising: a load sensor attached to a member to be loaded of a vehicle that generates a distortion when a load is applied and detecting the load based on the distortion of the member to be loaded. The load member is a column member having a hollow rectangular cross section having a side surface on which the amount of strain increases or decreases in proportion to the increase or decrease of the load, and the load sensor is attached to the side surface of the column member. A load measuring device for a vehicle, comprising: 2. The vehicle load measuring device according to claim 1, wherein the column member is a joist column which is an intermediate member interposed between a frame and a carrier of the vehicle. measuring device. 3. The load measuring device for a vehicle according to claim 2, wherein a plurality of the load sensors are attached to the joist column, and the load is detected based on detection outputs of the plurality of load sensors. A load measuring device for a vehicle, comprising: