JPH05322637A - Failure diagnosis system for truck scale - Google Patents

Abstract

PURPOSE:To find or predict failure at the initial stage regardless of the extent thereof by sequentially checking the load pattern at the time of weighing and then sequentially checking variance of measurement reference point under no- load. CONSTITUTION:An indicator 3 subjects load signals delivered from a plurality of load sensors 2a-2d to A/D conversion 4 and arithmetic processing 5 to produce a truck weight to be displayed 6. The indicator 3 is provided with a comparing function section 7 having function for sequentially checking load patterns based on output values subjected to A/D conversion 4 and a function for sequentially checking variance of measurement reference point under no-load(normal state) where no load is applied from a truck to be measured. An abnormality signal is outputted when the load pattern varies at the time of weighing or when the variance of measurement reference point deviates from a preset allowable range under no-load. This system can make an instantaneous diagnosis of the occurrence of failure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a truck scale failure diagnosis system for measuring the total load of vehicles.

[0002]

2. Description of the Related Art Truck scales are often used for voluntary management of factories and transaction certification, such as the storage of raw materials and the management of product shipments in factories.

Conventionally, as a track scale, a track scale has been proposed in which a track to be measured is moved without stopping on a mounting table and the weight of the track is measured while the track to be measured passes over the mounting table. (For example, refer to JP-A-1-148917 as prior art.) In this track scale, a track to be measured is placed on a mounting table, and load signals output from a plurality of load sensors arranged on the mounting table are processed by a computer. Then, the truck weight is displayed.

As described above, the track scale is a highly accurate scale and is always required to have high reliability. Therefore, load inspection has been conventionally performed. This test is generally
It is carried out by an inspection method in which a weight is placed on a mounting table, or a simple inspection method called "multiplying" in which an inspection is performed using a truck whose weight measured by another truck scale is known.

[0005]

In the load inspection of the above-mentioned track scale, the inspection using the weight requires a weight of several tens of tons, and it cannot be easily carried out. I'm just Also,
Inspections using trucks require another truck scale of the same scale nearby, making frequent inspections difficult.

[0006] By the way, regarding a failure of the truck scale, when a large change in the measured value appears, for example, when the change amount of the load cannot be detected at all, such as the disconnection of the cable, the operator or the driver of the vehicle can easily do so. You can find the breakdown.

However, a load sensor or an A / D that constitutes a load detection unit due to a natural disaster such as a shock load or a lightning which exceeds the rating.
It is good if the operator or the driver of the vehicle can immediately judge the failure due to a large measurement error due to a failure that occurs in the converter, but if not, the failure situation will continue for a long time. The impact is tremendous and the credit for business can be greatly lost, which may cause a great deal of damage.

For example, when a crack occurs in a part of the metal elastic body constituting the load sensor and the sensitivity of the load sensor gradually changes, or a shock load (overload) exceeding the rating is applied, the metal elastic body is slightly When there is a slight shift in the output value when there is no load, the measured value does not change extremely greatly as described above, but the measured value is only a change within the measuring range of the load sensor. It may not be possible to determine that a failure has occurred until the time has elapsed.

The present invention has been made in view of the above points, and regardless of the size of the failure, the failure is discovered or predicted at an early stage, and the influence of the failure is minimized. Stop, without relying on regular load inspection,
It is an object of the present invention to provide a truck-scale fault diagnosis system that can always maintain high reliability.

[0010]

SUMMARY OF THE INVENTION To achieve the above object, the gist of the present invention is to move a track to be measured on a mounting table provided with a plurality of load sensors, and to measure the track to be measured. In the process of moving on the platform, based on the load pattern obtained from the load signal output from each load sensor, the track scale that weighs the track is checked for abnormal load patterns by sequentially checking the load pattern during weighing. Means for outputting the abnormal signal when the fluctuation value of the measurement reference point is sequentially checked when there is no load on the platform and when there is no load on the platform and the fluctuation value exceeds a preset allowable range. The present invention is a truck-scale failure diagnosis system characterized by being equipped with.

[0011]

Function A failure such as a decrease in the sensitivity of the load sensor or the A / D converter is diagnosed by sequentially checking the load pattern based on the A / D converted output value.

Further, by continuously checking the variation value of the measurement reference point when no load is applied from the track to be measured, the failure diagnosis is also made from this aspect.

[0013]

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

FIG. 1 is a side view of an essential part of a track scale to which the present invention is applied, and FIG. 2 is a basic configuration diagram of an indicating device.

In the figure, 1 is a mounting table and 2 is a load sensor. The platform 1 is installed on the floor surface (or the ground) B on which the track A to be measured moves, and the length L2 in the direction in which the track A moves is determined by the distance L1 from the front wheel A1 to the rear wheel A2 of the track A to be measured. It is set long. The load sensor 2 outputs a load signal by replacing the load (force) with the deflection of a metal elastic body and replacing the magnitude of the deflection with a change in electrical resistance using a strain gauge, and outputs four load signals. The load sensors 2a, 2b, 2c, 2d are mounted on the corners of the platform 1. In addition, in the drawing, the stand 1
The front load sensors 2a and 2b and the rear load sensors 2c and 2d are shown as one respectively.

Reference numeral 3 is an indicating device, and this indicating device 3 is A /
The D converter 4, the arithmetic circuit 5, and the display unit 6 are the main components, and after the load signals output from the respective load sensors 2a, 2b, 2c, 2d are A / D converted, arithmetic processing is performed to display the track weight. It is a thing.

In the above structure, the track A to be measured is now
The total weight of W, the weight applied to the front wheel A1 is W1, the rear wheel A2
Letting W2 be the weight to be applied, it is assumed that the relational expression of W = W1 + W2 holds.

When the track A to be measured moves and its front wheel A1 is first placed on the platform 1, the load applied to the platform 1 is neglected by the weight of the platform 1, and the front wheel A1 is placed on the rear wheel A2. When the rear wheel A2 is placed next, the entire track A to be measured is placed on the platform 1, and the load is (W = W1 + W2). When getting off, after the front wheel A1 gets off, the rear wheel A2
It will be a constant value (W2) until the vehicle gets off.

FIG. 3 is a diagram of a basic load pattern showing this relationship. In the drawing, the basic load pattern is shown using the length L2 of the platform 1 and the distance L1 between the front wheel A1 and the rear wheel A2 of the track A to be measured. That is, in the figure, 0 to L
In the range of 1, the load is applied only to the front wheel A1, and in the range of L1 to L2, the load (total weight) of the front and rear wheels A1 and A2 is applied.
Further, the range of L2 to L1 + L2 shows a state in which the load is applied only to the rear wheel A2, and each load sensor 2a, 2b, 2
When c and 2d are operating normally, the load does not change in each range.

FIG. 4 is a block diagram of an indicating device showing an embodiment of the present invention.

In the present invention, the comparison function unit 7 is additionally provided in the above-mentioned pointing device 3, and the comparison function unit 7 is provided.
Is a function of sequentially checking the load pattern based on the output value that is A / D converted by the A / D converter 4, and a measurement reference point when no load is applied from the track A to be measured (normal use state). To sequentially check the fluctuation value of 2
It has two check functions and outputs an abnormal signal when the load pattern changes at the time of weighing and when the fluctuation value of the measurement reference point exceeds the preset allowable range when there is no load.

FIG. 5 is a block diagram of an indicating device showing another embodiment of the present invention.

In this embodiment, each load sensor 2
A / D converters 2a, 2 are provided for each of a, 2b, 2c, 2d.
b, 2c, 2d are provided, and an adder circuit 8 for adding the values after A / D conversion is provided. Each load sensor 2a, 2
Not only the failure of b, 2c and 2d but also each A / D converter 2a,
2b, 2c, 2d can be diagnosed, and the load sensor and the A / D converter that have failed can be specified in the variation value check of the measurement reference point when there is no load.

FIG. 6 is a diagram showing a change in the load pattern when the load sensor fails, and FIG. 7 is a flow chart showing a function of the comparison function section when the load pattern changes.

In the above embodiment, assuming that one rear load sensor 2d fails and the sensitivity of the load sensor 2d becomes small, the front wheels A1 and A2 of the track A to be measured are loaded at the time of weighing. The load pattern is such that the detected load decreases as it approaches the sensor 2d.

That is, in FIG. 6, Wa is a value immediately after the front wheel A1 of the track A to be measured is placed on the platform 1, Wb.
Is the value immediately before the rear wheel A2 is placed on the platform 1, and Wc is the front wheel A
1 and the value of the rear wheel A2 immediately after being placed on the platform 1, W
d is the value just before the front wheel A1 descends from the platform 1, W
e represents a value immediately after the front wheel A1 has descended from the platform 1, and Wf represents a value immediately before the rear wheel A2 descends from the platform 1.

Therefore, each load sensor 2a, 2b, 2
When c and 2d are operating normally, Wa and Wb are W
1, Wc and Wd should indicate W, and We and Wf should indicate W2, but since the load pattern changes due to a failure of the load sensor 2d, an abnormal signal is output from the comparison function unit 7 and a failure occurs. Whether it can be instantly diagnosed.

FIG. 8 is a diagram showing measurement reference points during weighing, and FIG.
6 is a flowchart showing the function of the comparison function unit when the measurement reference point changes.

The track scale is required to have sufficient rigidity to withstand the load, based on the weight of the track weighed.
The weight of the loading platform is quite large, and since it is required that all the wheels of the track to be measured be loaded on the loading platform, the area is fairly wide. It is installed outdoors from the handling side, and there is a drop of earth and sand that is loaded on the track to be measured at the time of weighing and earth and sand that adheres to the tire on the platform, and rain and snow adhered and accumulated. There is also. Therefore, even if the track scale itself is in a normal state, the fluctuation of the measurement reference point at the time of weighing, that is, the fluctuation of the load under no load, which is regarded as the zero point, is allowed within a predetermined range.

According to the present invention, the fluctuation value of the measurement reference point at the time of weighing is set practically when no load is applied from the track to be measured, and for example, the earth and sand carried on the platform. 10 to 100 kg of the allowable fluctuation value of the measurement reference point when measuring from the practical point, considering the case where
It is set to a degree.

That is, in FIG. 8, T1 indicates a weighing period during which the track to be measured is placed on the mounting table in a normal use state, and T2 indicates a time when no load is applied to the mounting table from the track to be measured. A period is shown and this is alternately repeated at the time of use, but in the present invention, the variation value of the measurement reference point in the period T2 when there is no load before and after the measurement period T1 is preset and stored, When the allowable variation value is exceeded before and after the measurement period T1, an abnormal signal is output from the comparison function unit 7 to diagnose a failure.

In the case of the embodiment shown in FIG. 5, in the variation value check of the measurement reference point when there is no load, each load sensor stores the allowable variation value, and each load sensor independently. Checking makes it easier to identify a faulty load sensor, shortens repair time, and improves maintenance.

Further, as described above, when the failure is diagnosed by checking the fluctuation value of the measurement reference point at the time of no load, it is not always the failure of the scale itself, but the soil and snow accumulated on the platform are removed. It is often resolved by things.

Further, in the above-mentioned embodiment, the track scale having a construction in which the loading platform is directly supported by a plurality of load sensors has been described.
Of course, the present invention can also be applied to a blade, a blade, and a blade receiver.

[0035]

According to the present invention having the above-mentioned structure, by utilizing the characteristics of the load pattern of the track scale, the change of the load pattern at the time of weighing and the fluctuation value of the measurement reference point at the time of no load are used. Failures can be instantly diagnosed by checking them one by one during operation, prompting prompt and corrective actions thereafter to prevent the spread of the impact and requiring special inspections such as applying loads. Without doing so, the reliability of the truck scale is significantly improved.

[Brief description of drawings]

FIG. 1 is a side view of an essential part of a track scale to which the present invention is applied.

FIG. 2 is a basic configuration diagram of an instruction device.

FIG. 3 is a diagram of a basic load pattern.

FIG. 4 is a configuration diagram of an indicating device showing an embodiment of the present invention.

FIG. 5 is a block diagram of an indicating device showing another embodiment of the present invention.

FIG. 6 is a diagram showing changes in a load pattern.

FIG. 7 is a flowchart showing the function of a comparison function unit.

FIG. 8 is a diagram showing measurement reference points at the time of weighing.

FIG. 9 is a flowchart showing functions of a comparison function unit.

[Explanation of symbols]

 1 ... Platform 2 ... Load sensor 3 ... Indication device 4 ... A / D converter 5 ... Arithmetic circuit 6 ... Display unit 7 ... Comparison function unit 8 ... Addition circuit A ... Track to be measured

Claims (1)

[Claims] 1. A load signal output from each load sensor in the process of moving a track to be measured on a mounting table equipped with a plurality of load sensors and moving the track to be measured on the mounting table. In a truck scale that weighs the weight of a truck based on the load pattern that is measured, the load scale during weighing is sequentially checked, and when there is an abnormality in the load pattern, and when there is no track to be measured on the platform, there is no measurement standard. A truck scale fault diagnosis system comprising means for successively checking the variation value of a point and outputting an abnormal signal when the variation value exceeds a preset allowable range.