JP2000002737A - Electric wiring connection abnormality detecting device of construction machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for detecting abnormalities in connection before an electric wiring or the like occurs is discontinued. SOLUTION: This device for detecting abnormalities of electric wiring connection between a condition measuring instrument 14 for detecting operation conditions of a working machine for construction and a controller 15 has such a characteristic that abnormality in electric wiring connection is detected based on the change with the passage of time of a signal from the condition measuring instrument 14, and is equipped with a recording means 25 for detecting the number of times of generation and the places of generation of abnormal signal, and recording the number of times of generation and error codes showing the places of generation of abnormalities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a detection apparatus for detecting an abnormality in connection of electric wiring due to a poor connection of electric wiring of a construction machine or a poor contact of a connector.

[0002]

2. Description of the Related Art In operating and controlling a working machine of a construction machine such as a hydraulic excavator, a hydraulic electric circuit is used. FIG. 6 shows an example of a block diagram for operating and controlling a working machine of a construction machine. In FIG. 6, an operation signal is sent from a remote operation means 10 such as an operation lever for operating a remote control valve to a hydraulic electric circuit 11, and the hydraulic electric circuit 1
The actuator 12 is controlled by the control signal from the controller 1, and the work implement 13 is operated based on the operation of the actuator 12.

On the other hand, the state of the working machine 13 can be known by calculating measurement data from a state measuring device 14 including an analog sensor and a digital sensor such as a switch provided on the actuator 12. The controller 15 outputs a control signal to the hydraulic electric circuit 11 based on the measurement data from the state measuring device 14 and the input data from the setting device 16 for setting a mode selection and parameters, and controls electric elements such as a solenoid valve. I do. As described above, construction machines such as hydraulic shovels also have portions connected by electric wiring, and if a connection abnormality occurs in these portions, work machine control cannot be performed well. Further, it is difficult to detect the occurrence of an abnormality due to electric wiring or the like from the outside.

Conventionally, the connection between the state measuring device 14 and the controller 15 by electric wiring is made such that the analog sensor 18 and the switch 17 of the state measuring device 14 can be easily replaced as shown in FIG. Connectors 19, 2
0. The connector 19 indicates a connector for a digital signal line, and the connector 20 indicates a connector for an analog signal line. The connector 19b in FIG.
Reference numeral 20b denotes a connector having a connection failure. Disconnection and poor connection of the electric wiring itself may occur, but the connectors 19, 2
In the case of 0, the connection portion is loosened by the vibration of the machine, so that a connection failure (or a contact failure) is likely to occur. Further, the connection portion between the connector and the electric wiring is also likely to cause a connection failure. Therefore, it is important to inspect the connection failure of the electrical wiring between the state measuring device 14 and the controller 15 and the connection portion of the connector (hereinafter, referred to as electrical wiring connection) in order to operate the construction machine normally.

However, conventionally, an apparatus and a method for detecting a non-connection state when an electric wiring connection is completely disconnected and disconnected (or short-circuited) have been conventionally known. Disconnection of wiring or the like often results in a state of poor connection lasting longer than it suddenly occurs, and eventually leads to disconnection. Since the conventional abnormality detection device pays attention only to the current value of the analog signal or the digital signal, the state of the connection failure before the disconnection occurs is not detected. In addition, the occurrence of an abnormality due to poor connection has low reproducibility and it has been difficult to detect it.

[0006]

As described above, conventionally, the state of disconnection has been detected after disconnection of an electric wiring or the like. However, it is important to investigate the cause and prevent it before an accident or trouble occurs due to disconnection of electric wiring or the like, which is a current problem. The present invention has been made under the above background, and has as its object to provide an apparatus for detecting an abnormality in a connection state before disconnection of an electric wiring or the like occurs.

[0007]

The present invention employs the following means to solve the above-mentioned problems. That is, claim 1
The described invention is an apparatus for detecting an abnormality of an electric wiring connection between a state measuring device for detecting an operation state of a working machine of a construction machine and a controller for controlling the working machine, wherein the abnormality detecting device includes the state measuring apparatus. The abnormality of the electrical wiring connection is detected based on a time change of a signal from the device.

According to a second aspect of the present invention, in the first aspect of the invention, the abnormality detecting device detects the number of occurrences and the location of the occurrence of the abnormal signal, and outputs an error code indicating the number of occurrences and the location of the abnormality. Recording means for recording the information.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the abnormality detecting device includes a recording means for calculating an occurrence time of the abnormality signal and recording the occurrence time. It is characterized by:

According to a fourth aspect of the present invention, in the first aspect of the present invention, the abnormality detecting device includes a display unit for displaying the recorded data content.

[0011]

FIG. 1 is a block diagram showing functions of an embodiment of the present invention. FIG. 2 shows the configuration of the apparatus of the present embodiment. FIG. 3 shows an example of an abnormal state of an electric wiring connection for transmitting an analog signal. FIG. 4 shows an example of an abnormal state of an electrical wiring connection for transmitting a digital signal. Less than,
An embodiment of the present invention will be described with reference to the drawings.
Note that the same components as those described in the conventional device are denoted by the same reference numerals, and detailed description is omitted.

In FIG. 1, the abnormality detecting device 30 is connected to a signal output terminal of the controller 15. Note that the signal output to the signal output terminal may be the input signal from the state measuring device 14 as it is, or may be output after performing an appropriate deformation process. The abnormality detection device 30 includes an arithmetic unit 21 for obtaining a time change rate of a signal, an abnormality determination unit 22 for determining a connection abnormality from an abnormality in the change rate, an arithmetic unit 23 for performing processing when it is determined that an abnormality has occurred, and detecting an abnormality occurrence time. A display circuit 26 for outputting a display signal to a display 27.

The rate-of-change computing unit 21 performs a time change of the analog signal or the digital signal of the electric wiring for detecting the connection abnormality from the signals input from the state measuring device 14 to the controller 15 as described below. Find the rate. FIG. 3 is a diagram illustrating an example of an analog signal in a normal state and an analog signal in an abnormal state. FIG. 3 shows an analog signal assuming that a signal takes a maximum value when a wire is broken and takes a minimum value when a short circuit occurs. (A) shows a normal case,
(B) shows the case of an abnormality. Time T indicates a sampling period. As can be seen from the figure, when an abnormality such as a connection failure occurs, the signal is smaller than the maximum value and larger than the minimum value.

The lower part of FIG. 3 is an enlarged view of the change in the normal state and the abnormal state. The change rate (Xa / T) at the time of abnormality is clearly larger than the change rate (Xn / T) at the time of normal. The abnormal state shown in (b) does not always occur, but occurs according to the vibration of the construction machine or the vibration of the engine. The abnormal state can be detected by constantly monitoring the signal. The sampling period T needs to be short enough to detect an abnormal state. The sampling period T can be easily determined by knowing the cause of the appearance or disappearance of the abnormal state.

FIG. 4 shows a waveform of a digital signal at a normal time and a waveform at an abnormal time. In FIG. 4, the waveform (A) in the normal state during the period (NT) of the sample period T and the number of samples N is shown on the upper side, and the waveform (B) in the case of poor connection is shown on the lower side. As can be seen from the figure, the number of changes from ON to OFF and the number of changes from OFF to ON are two in the normal state, and seven times in the abnormal state. The number of times is significantly increased. It is considered that this is because the resistance of the connection changes due to vibration of the construction machine or the like due to poor contact of the connector or the like. The rate of change of the digital signal may be, for example, (number of changes / NT).

As described above, the change rate calculator 21
For analog signals, calculate the rate of change of the signal every sample or every few samples, and for digital signals, change from on to off and off to on every predetermined number of samples (N) Find the number of changes. Abnormality judgment device 2
2 judges an abnormality from the signal change rate or the number of signal changes.
That is, when these values are extremely large, it is determined that an abnormal state has occurred, and when these values are expected, it is determined that the state is normal.

When the processing arithmetic unit 23 determines that the state is abnormal, it attaches an error code to the electric wiring in which the abnormality has occurred,
At the same time, the cumulative number of times an abnormality has occurred is determined. Further, if necessary, the abnormality occurrence time is obtained from the time from the timer 24. Further, the processing arithmetic unit 23 outputs the obtained data to the recording unit 25 and the display circuit 26. The recording means 25 records the received data. The display circuit 26 converts the data so that the received data is displayed on the display 27 and outputs the converted data.

FIG. 2 shows a specific example of the hardware configuration of the abnormality detector 20. The abnormality detector 20 is the arithmetic unit 3
1, a non-volatile memory 32 such as a ROM, a memory 33 such as a RAM capable of recording and reading a calculation result, a timer 34,
An interface 35 for receiving measurement data from the digital sensor 17; an interface 36 for receiving measurement data from the analog sensor 18;
8 comprises an interface 37 for displaying data.

A program for executing the function of the present invention is recorded in the nonvolatile memory 32. The arithmetic unit 31 receives the data from the sensors 17 and 18 and calculates the change rate described with reference to FIG. The state is determined, and in the case of an abnormality, the cumulative number of occurrences of the abnormality is calculated, the abnormal part is detected and an error code is attached, and the time of occurrence of the abnormality is obtained by the timer 34. The obtained result is recorded in the memory 33 and displayed on the monitor 38 via the interface 37.

FIG. 5 is a functional block diagram showing another configuration of the present embodiment. In FIG. 5, the abnormality detection device 40 includes a high-pass pass felter 41, a rectifier circuit 42, a smoothing circuit 43,
It comprises an abnormality determination circuit 44, a processing operation unit 23, a timer 24, a recording means 25, and a display circuit 26. The high-pass filter 41 is constituted by an analog filter for an analog signal, and is constituted by a digital filter for a digital signal. Rectifier circuit 42, smoothing circuit 4
3. The same applies to the abnormality determination circuit 44.

Since the measurement signal from the controller 15 contains a high frequency component when the wiring connection is abnormal, compared to the normal case,
This component is taken out and abnormality detection is performed. That is, the low-frequency component at the normal time is cut by the high-pass filter from 41,
Only the high frequency component indicating the connection abnormality passes. This high-frequency component has a direct-current component removed and becomes a high-frequency alternating-current component. The rectifier circuit 42 allows only one of the positive and negative signals to pass and cuts the other. The smoothing circuit 43 smoothes the rectified signal. The abnormality determination circuit 44 determines that the signal is abnormal when the smoothed signal exceeds a predetermined threshold, and determines that the signal is normal when the signal is less than the predetermined threshold.

The operation is performed in the same manner as in the abnormality detector 30 described above. The processing arithmetic unit 23 calculates and calculates the cumulative number of abnormal occurrences, attaches an error code, and obtains an abnormal occurrence time. The recording means 25 records the obtained data, and the display circuit 26 and the display 27 display the data.

According to the present embodiment, a contact or poor connection with low reproducibility can be detected before the electrical connection is completely disconnected or short-circuited by the configuration and function described above. Thus, it is possible to prevent the occurrence of an accident or inconvenience due to the above.

The embodiments and examples of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the examples, and the design can be changed without departing from the scope of the present invention. The present invention is included in the present invention. For example, although the above description has been made in terms of hardware, software having the same function may be realized. Further, although the abnormality detector has been separately described and described, it may be realized by one computer together with a controller or the like.
In the above embodiment, the determination is made based on the output signal from the controller 15, but the input signal to the controller 15 may be directly input to the abnormality detector.

[0025]

As described above, according to the configuration of the present invention, it is possible to detect a contact or poor connection with low reproducibility before the electrical connection is completely disconnected or short-circuited. Thus, it is possible to prevent the occurrence of an accident or inconvenience due to a defect such as the above.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating functions of an embodiment of the present invention.

FIG. 2 shows a specific configuration example of the present embodiment.

FIG. 3 shows a waveform example of an analog signal.

FIG. 4 shows a waveform example of a digital signal.

FIG. 5 shows another configuration example of the embodiment.

FIG. 6 is a block diagram showing functions in a conventional device.

FIG. 7 shows a configuration example of a conventional device.

[Explanation of symbols]

14 State measuring device 15 Controller 17 Switch or digital sensor (Status measuring device) 18 Analog sensor (Status measuring device) 19, 20 Connector (Electrical wiring connection) 21 Change rate calculator 22 Abnormality judging device 23 Processing calculator 24 Timer 25 Recording Means 26 Display circuit 27 Display device 30, 40 Abnormality detection device

Claims (4)

[Claims] 1. An apparatus for detecting an abnormality of an electric wiring connection between a state measuring device for detecting an operation state of a working machine of a construction machine and a controller for controlling the working machine, wherein the abnormality detecting device includes the state measuring apparatus. An abnormality detection device for electric wiring connection of a construction machine, wherein the abnormality is detected based on a time change of a signal from a container. 2. The apparatus according to claim 1, wherein the abnormality detecting device includes a recording unit that detects the number of occurrences and the location of the occurrence of the abnormal signal, and records the number of occurrences and an error code indicating the location of the abnormality. 2. The abnormality detection device for electrical wiring connection of a construction machine according to 1. 3. The apparatus according to claim 1, wherein the abnormality detecting device includes a recording unit that calculates an occurrence time of the abnormality signal and records the occurrence time. Abnormality detection device for electrical wiring connection of construction machinery. 4. The electric wiring connection of a construction machine according to claim 1, wherein said abnormality detecting device comprises a display means for displaying the recorded data contents. Abnormality detection device.