KR20220165188A - Damage detecting system for working tool of automatic machine tool and method thereof - Google Patents

Abstract

The present invention relates to a system and method for diagnosing damage to a machining tool of a machine tool, and more specifically, automatically diagnoses damage when using various tools of a machine tool and provides an alarm to a user or interlocking control to a nearby device when diagnosing an abnormality. It relates to a system for diagnosing damage to a machining tool of a machine tool and a method therefor.

Description

Machine tool damage diagnosis system and method {DAMAGE DETECTING SYSTEM FOR WORKING TOOL OF AUTOMATIC MACHINE TOOL AND METHOD THEREOF}

The present invention relates to a system and method for diagnosing damage to a machining tool of a machine tool, and more specifically, automatically diagnoses damage when using various tools of a machine tool and provides an alarm to a user or interlocking control to a nearby device when diagnosing an abnormality. It relates to a system for diagnosing damage to a machining tool of a machine tool and a method therefor.

In general, a so-called numerical control (NC) machine tool that processes a product to be processed using various tools by controlling the movement of the tool according to numerical data already input and automatically processing the product to be processed is a machine tool that uses various tools. It is known.

For example, an object to be processed having a complex shape, such as a hole in a cylinder block of an automobile, a curved surface or a bent surface of a valve seat surface, etc., is a type of automation technology and an intelligent production system, numerical control ( NC) It is being processed by machine tools.

That is, the machine tool can be controlled according to a predetermined program stored in advance to process a workpiece in a desired size, shape, and shape in a desired quantity.

At this time, a computer system and sensors are used to monitor and control the abnormal state of the machining process for processing the workpiece in order to make the machine tool intelligent, but a change in tool characteristics during machining of the workpiece may cause an abnormal state of the machining process.

Therefore, the machine tool as described above has the advantage of being able to process products quickly and automatically using various tools, but when tool damage occurs, if it is not dealt with in a timely manner, not only the product but also subsequent products are defective. As a result, there is a problem that a large loss cost may occur.

In recent years, machine tool setting and management have become complicated due to multi-variety small-lot production and option production, while automation and unmanned automation have reduced the number of managers, making it more difficult to timely identify tool damage and take action.

On the other hand, most of the existing tool damage diagnosis monitoring devices are contact type, and in the process of contacting the tool at various angles to the sensor before operation, the difference in contact distance was used to determine whether or not the tool was damaged.

This has a disadvantage in that an inspection process and additional time are required in addition to the processing time, or a contact sensor is separately required for each tool size.

In addition, the existing process for diagnosing whether or not there is an abnormality in a machine tool includes a step of acquiring field sensing data, a step of transmitting to a server, a step of analyzing and diagnosing in a server, and a step of transmitting an alarm and control signal to the field when an abnormality occurs as a result of server analysis.

As described above, the conventional machine tool abnormality diagnosis process is composed of many steps, so it is complicated, and the initial cost burden is also high due to the construction of a network system.

The present invention provides a system for diagnosing damage to a machining tool of a machine tool and a method for automatically diagnosing damage when using various tools of a machine tool and enabling a user to alarm or link control to a nearby device when diagnosing an abnormality. aims to

In addition, the present invention is an all-in-one diagnostic device that is not affected by tool size and can analyze and process only one device without the need for a calculation server, and diagnoses damage to a machining tool of a machine tool including a machine tool abnormality diagnosis device. It aims to provide a system and its method.

In addition, the present invention is a system for diagnosing damage to a machining tool of a machine tool that can solve the overload problem of the main server because the analysis process of the monitoring target device performed in the main server is performed in parallel in the machine tool abnormality diagnosis device of the monitoring target device. and to provide a method thereof.

In addition, an object of the present invention is to provide a system and method for diagnosing damage to a machining tool of a machine tool that can increase on-site utilization by adding one small-sized device without building a separate analysis server or networking system.

In addition, an object of the present invention is to provide a system and method for diagnosing damage to a machining tool of a machine tool, which enables a user to alarm and follow-up control when tool damage occurs, thereby minimizing the cost of quality loss for a machining company.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned above can be understood by the following description and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by means of the instrumentalities and combinations indicated in the claims.

A machine tool abnormality diagnosis system for achieving this purpose includes a main server capable of controlling a plurality of monitoring target devices; a receiving unit including a communication port connectable by wire in order to receive basic machine tool information from the monitoring target device; a processing frequency generation unit generating a processing frequency using the machine tool basic information received from the machine tool basic information receiving unit; a storage unit for storing a vibration signal of an acceleration sensor formed in the monitoring target device; According to the initial signal analysis request signal, the vibration signal of the acceleration sensor stored in the storage unit is divided into predetermined time intervals to perform initial signal analysis, and then an initial signal analysis result is generated. According to the initial signal analysis result, a detailed analysis request signal is generated. When received, a machine tool abnormality diagnosis unit that compares the previously calculated processing frequency and the vibration signal of the acceleration sensor to diagnose whether or not the monitoring target device is abnormal; wherein the diagnosis unit includes a difference between natural frequency and processing frequency for each machine tool After calculating , it is checked whether the monitoring target device is normal according to the frequency, and the information of the monitoring target device received in advance and the information obtained through the above analysis process are the same or as a result of checking the data for each time interval, continuously for more than a specific time a diagnosis unit for determining an end signal when the data analysis condition is not satisfied; When the machine tool basic information is received from the machine tool basic information receiving unit, noise elimination processes such as spike removal and filtering may be performed together, and a standby mode is entered to check whether a vibration signal exceeding a specific value is generated, and the standby mode When a signal representing the start of the process is received in the signal acquisition mode, the signal acquisition mode controls the vibration signal to be stored in the storage unit, and then requests an initial signal analysis for the vibration signal of the acceleration sensor stored in the storage unit. A control unit providing a signal to the machine tool abnormality diagnosis unit and providing a detailed analysis request signal to the machine tool abnormality diagnosis unit according to the initial signal analysis result, and displaying an alarm to an operator when the system is abnormal. It is characterized in that it can control a plurality of monitoring target devices that generate a control signal to stop the automatic supply device.

In addition, in the method for diagnosing whether or not there is an abnormality in a machine tool to achieve this purpose, in the method for diagnosing whether there is an abnormality in a machine tool executed by a machine tool abnormality diagnosis device, when basic machine tool information is received from a user or a device to be monitored, spike removal and filtering are performed. A step of entering a standby mode to check whether a vibration signal of a certain value or more is generated; switching from the standby mode to a signal acquisition mode when receiving a signal representing the start of a process in the standby mode; performing an initial signal analysis by dividing the vibration signal of the acceleration sensor stored in a memory in the signal acquisition mode by a predetermined time interval; switching to a detailed analysis mode according to whether a valid signal is received in the process of performing the initial signal analysis; Comparing the pre-calculated processing frequency and the vibration signal of the acceleration sensor in the detailed analysis mode; And diagnosing whether or not the monitoring target device is abnormal according to the comparison result; including, after calculating the difference between the natural frequency and the processing frequency for each machine tool, checking whether the monitoring target device is normal according to the frequency, If the information of the device to be monitored previously received and the information obtained through the above-mentioned analysis process are the same, or if the data analysis condition is not satisfied continuously for more than a certain period of time as a result of checking the data for each time period, it is judged as an end signal, and the system is abnormal. It displays an alarm to the worker and generates a control signal to stop the automatic supply device, and whenever the process of the monitoring target device is completed, the main server receives the result data for the process from the machine tool abnormality diagnosis device to receive the The device to be monitored is controlled according to the data obtained, but a plurality of devices to be monitored can be controlled.

According to the present invention as described above, there is an advantage in automatically diagnosing whether a machine tool is damaged when using various tools, and when diagnosing an abnormality, it is possible to alarm the user or interlock control with nearby devices.

In addition, according to the present invention, since the analysis process of the monitoring target device performed by the main server is performed in parallel by the device for diagnosing whether or not the machine tool is abnormal in the monitoring target device, it is possible to solve the overload problem of the main server.

In addition, according to the present invention, there is an advantage that productivity can be increased because an additional inspection process or time added to the conventional processing process is unnecessary.

In addition, according to the present invention, there is an advantage that on-site utilization can be increased by adding one small-sized device without building a separate analysis server or networking system.

In addition, according to the present invention, there is an advantage in minimizing the quality loss cost of the machining company by allowing the user to alarm and follow-up control when tool damage occurs.

In addition, according to the present invention, there is an advantage in that utilization can be increased so that it can be easily used in the field by applying an LCD and a touch panel.

1 is a diagram showing that a conventional machine tool abnormality diagnosis system is implemented.
2 is a diagram showing that the system for diagnosing abnormalities in a machine tool according to the present invention is implemented.
3 is a network configuration diagram for explaining a conventional machine tool abnormality diagnosis system.
4 is a network configuration diagram illustrating a system for diagnosing an abnormality in a machine tool according to the present invention.
5 is a block diagram illustrating an internal structure of an apparatus for diagnosing an abnormality in a machine tool according to an embodiment of the present invention.
6 is a flowchart illustrating a method for diagnosing whether a machine tool is abnormal according to an embodiment of the present invention.
7 is an exemplary view for explaining a method for diagnosing whether a machine tool is abnormal according to an embodiment of the present invention.
8 is an exemplary diagram for explaining a method for diagnosing whether a machine tool is abnormal according to an embodiment of the present invention.
9 is an exemplary diagram for explaining a method for diagnosing whether a machine tool is abnormal according to an embodiment of the present invention.
10 is an exemplary diagram for explaining a method for diagnosing whether a machine tool is abnormal according to an embodiment of the present invention.
11 is an exemplary view for explaining a method for diagnosing whether a machine tool is abnormal according to an embodiment of the present invention.
12 is a perspective view illustrating an apparatus for diagnosing whether a machine tool is abnormal according to an embodiment of the present invention.

The above objects, features and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention belongs will be able to easily implement the technical spirit of the present invention. In describing the present invention, if it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

1 is a diagram showing that a conventional machine tool abnormality diagnosis system is implemented.

Referring to FIG. 1 , the conventional system for diagnosing an abnormality in a machine tool is implemented by directly transmitting and receiving all data and signals of the monitoring target devices 20_1 to 20_N to one main server 10 .

In detail, a method of determining whether a machining tool of a machine tool is damaged is performed by using a method of contacting a sensor at various angles depending on a difference in contact distance or the like before controlling or operating the machining tool.

Such a conventional machine tool abnormality diagnosis system has a disadvantage in that an inspection process and additional time are required in addition to processing time, and a contact sensor is separately required for each tool size.

In addition, since one main server has to directly transmit and receive information of several devices to be monitored, there is a problem in that the time required from determining whether a machining tool is damaged to processing is increased in proportion to the number of devices to be monitored.

The present invention is proposed to solve the problems of the conventional machine tool abnormality diagnosis system.

2 is a diagram showing that the system for diagnosing abnormalities in a machine tool according to the present invention is implemented.

Unlike the conventional method in which a plurality of monitoring target devices directly contact one main server and performing all analysis and control only on the main server, in the present invention, the analysis and control process of the monitoring target device performed by the main server A device for diagnosing machine tool abnormalities (300_1 to 300_N) that can be used simultaneously has been added.

In the present invention, overload of the main server is prevented by adding the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool, and the user can control the contents and procedures of data.

More specifically, the present invention has added a machine tool abnormality diagnosis device as a method of solving the problems of the prior art, and the machine tool abnormality diagnosis device (300_1 to 300_N) performs simple calculations and extracts data, and then exports the processed data to the outside. It is controlled by the control devices (400_1 to 400_N), and the user display signal is directly transmitted to the monitoring device.

Meanwhile, the apparatus for diagnosing abnormalities in the machine tool transmits only essential data that needs to be stored to the main server 100 . The device for diagnosing abnormalities in the machine tool preferably uses an edge computer, and processes the data collected from the terminal device at the site or local area where the data is generated rather than directly sending it to a centralized cloud server.

In addition, the present invention includes a diagnosis method and apparatus that reduces dependence on a server and enhances field utilization by including GUI software and an LCD screen for transmitting the result value for the data controlled by the user to the outside as an display or an alarm. do.

Hereinafter, it will be described in detail.

3 is a network configuration diagram for explaining a conventional machine tool abnormality diagnosis system.

The conventional machine tool abnormality diagnosis system includes a main server 10 and monitoring target devices 20_1 to 20_N.

The main server 10 generates a control signal based on the data of the monitoring target devices 20_1 to 20_N and provides it to the external control devices 40_1 to 40_N of the monitoring target devices 20_1 to 20_N to monitor the monitoring target devices 20_1 to 20_N. 20_N).

In one embodiment, the main server 10 receives sensing information from the sensors 30_1 to 30_N of the monitoring target devices 20_1 to 20_N, and then generates a control signal according to the sensing information to monitor the monitoring target devices 20_1 to 20_N. ) may be provided to the external control devices 40_1 to 40_N to control the monitoring target devices 20_1 to 20_N.

Sensors 30_1 to 30_N are formed in the monitoring target devices 20_1 to 20_N, and sensing information sensed by the sensors 30_1 to 30_N is provided to the main server 10 .

As described above, in the conventional machine tool abnormality diagnosis system, all data of the monitored devices 20_1 to 20_N are provided to the main server 10, and the main server 10 provides data from the monitored devices 20_1 to 20_N. After receiving, a control signal is generated and the control signal is provided to the external control devices 40_1 to 40_N of the monitoring target devices 20_1 to 20_N to control the monitoring target devices 20_1 to 20_N.

However, in the conventional machine tool diagnosis system, as the number of monitored devices (20_1 to 20_N) increases, the amount of data that needs to be analyzed and processed in the main server 10 increases, and it takes a lot of time to analyze and process the data. There was a problem with this being required.

Meanwhile, FIG. 4 is a network configuration diagram illustrating a system for diagnosing an abnormality in a machine tool according to the present invention.

Here, the network of the present invention is a local area network (LAN), a wide area network (Wide Area Network; WAN), a mobile communication network (mobile radio communication network), all types of wired / wireless, such as Wibro (Wireless Broadband Internet) It can be implemented as a network.

Referring to FIG. 4 , the machine tool abnormality diagnosis system includes a main server 100, monitoring target devices 200_1 to 200_N, and machine tool abnormality diagnosis devices 300_1 to 300_N.

The apparatus for diagnosing abnormality of the monitoring target device and the machine tool of the present invention may include several (N = 1,2,3...) without limitation, but is preferably 1 to 50.

The reason for this is that if the number of monitoring devices and machine tool abnormality diagnosis devices exceeds 50, a connection error may occur during wireless connection.

The main server 100 of the present invention checks whether the monitoring target devices 200_1 to 200_N are operating normally by receiving and managing essential data from the machine tool abnormality diagnosis devices 300_1 to 300_N.

The main server 100 receives result data for the process from the machine tool abnormality diagnosis devices 300_1 to 300_N whenever the process of the monitoring target device 200_1 to 200_N is completed.

Accordingly, the main server 100 may determine that the monitoring target devices 200_1 to 200_N are operating normally according to the data received from the machine tool abnormality diagnosis devices 300_1 to 300_N.

The monitoring target devices 200_1 to 200_N are monitored devices whose abnormality diagnosis is monitored by the machine tool abnormality diagnosis devices 300_1 to 300_N. The monitoring target devices 200_1 to 200_N may be implemented as different types of tools and machine tools.

Acceleration sensors 210_1 to 210_N are formed in the monitoring target devices 200_1 to 200_N.

In one embodiment, acceleration sensors 210_1 to 210_N may be formed inside the chambers of the devices to be monitored 200_1 to 200_N to sense vibration data during processing. More specifically, acceleration sensors 210_1 to 210_N may be formed in a workpiece fixing jig of the monitoring target device 200_1 to 200_N.

The machine tool abnormality diagnosis device (300_1 to 300_N) is connected to the monitoring target device (200_1 to 200_N) to diagnose the abnormality of the monitored device, and whenever the process of the monitored device (200_1 to 200_N) is completed, the data is sent to the main It is provided to the server 100.

Therefore, the main server 100 can determine that the monitoring target devices 200_1 to 200_N are operating normally according to the data received from the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool.

The machine tool abnormality diagnosis device (300_1 to 300_N) monitors the vibration signal received from the monitoring target device (200_1 to 200_N) and the processing frequency generated based on the machine tool basic information of the monitoring target device (200_1 to 200_N). It is possible to determine whether or not the target devices 200_1 to 200_N are abnormal.

To this end, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool receive basic machine tool information from the user or the monitoring target device 200_1 to 200_N. In this case, the machine tool basic information may include the number of revolutions of the tool, the number of blades of the tool, the start point of machining, the machining time, and the like.

In one embodiment, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool provide a machine tool basic information input procedure through a display panel, and receive the machine tool basic information through the machine tool basic information input procedure.

In another embodiment, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool may receive basic machine tool information from the monitoring target devices 200_1 to 200_N. To this end, external control devices that control the monitored devices (200_1 to 200_N) and machine tool abnormalities are diagnosed in different ways depending on the type of external control devices (400_1 to 400_N) that control the monitored devices (200_1 to 200_N). Devices 300_1 to 300_N are connected by wire (eg, RS-485).

As described above, in order to connect the external control device that controls the monitoring target devices (200_1 to 200_N) and the machine tool abnormality diagnosis device (300_1 to 300_N) by wire, the machine tool abnormality diagnosis device (300_1 to 300_N) is subject to monitoring. Different types of communication ports corresponding to external control devices that control the devices 200_1 to 200_N may be formed.

Then, the machine tool abnormality diagnosis apparatuses 300_1 to 300_N generate a machining frequency using the machine tool basic information. In one embodiment, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool may generate the machining frequency using the following [Equation 1].

[Equation 1]

Frequency = Num_turn × Num_blade

Frequency: process frequency,

Num_turn: number of tool revolutions,

Num_blade: number of tool blades

That is, the machine tool abnormality diagnosis apparatuses 300_1 to 300_N calculate the machining frequency by using the number of tool revolutions (Num_turn) and the number of tool blades (Num_blade) among basic machine tool information. The machine tool abnormality diagnosis device (300_1 to 300_N) uses the processing frequency and the vibration signal received from the acceleration sensors (210_1 to 210_N) formed in each of the monitoring target devices (200_1 to 200_N) to be monitored (200_1 to 200_N). ) to diagnose abnormalities. In the following, this process will be described.

As described above, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool enter a standby mode after receiving basic machine tool information. The machine tool abnormality diagnosis device (300_1 to 300_N) receives a vibration signal for a certain period of time from the monitoring target device (200_1 to 200_N) in standby mode, and then uses the vibration signal to check whether a vibration signal of a certain value or more is generated. do.

Thereafter, when the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool are switched from the standby mode to the signal acquisition mode, they store vibration signals of the acceleration sensors received from the monitoring target devices 200_1 to 200_N in memory.

In one embodiment, when receiving a signal representing the start of one process of the machine tool in the standby mode, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool may switch from the standby mode to the signal acquisition mode.

The signal that represents the start of a process means the shock vibration that a workpiece is placed in the machine tool and the machine door is closed, or the shock vibration that restarts the processing motor that had stopped after the previous process. When these signals are received, the device switches to the signal acquisition mode. . Also, in the signal acquisition mode from the control device of the device to be monitored, the device recognizes that a new processing process has started, and determines whether a valid signal (ie, an actual processing signal) has been received.

In the signal acquisition mode, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool divide the vibration signals of the acceleration sensors stored in the memory by specific time intervals and perform initial signal analysis. For example, the predetermined time interval is 0.5 seconds, but may be changed according to user manipulation according to process conditions.

The above-described machine tool abnormality diagnosis devices 300_1 to 300_N determine whether the maximum value of the vibration signal of the acceleration sensor is greater than or equal to the reference value in order to determine a valid signal. It is checked whether the second condition for a specific value or whether both the first and second conditions are satisfied, and according to the check result, a detailed analysis mode for the vibration signal of the acceleration sensor is entered.

In the detailed analysis mode, for example, the machine tool abnormality diagnosis device (300_1 to 300_N) sets the maximum reference value to 0.1g and the constant repetition condition of the level value to 0.07g 10 times or more within 0.1 second, and the acceleration For the vibration signal of the sensor, whether the maximum value is greater than or equal to the reference value or when a certain level value below the certain level continuously repeats at the same time is determined as a data analysis start condition. At this time, the maximum reference value and level value. Criteria (or/and) of continuous repetition conditions and analysis start conditions may vary depending on process conditions such as the material of the workpiece, surface and core conditions, and processing size/shape, which can be adjusted by the user.

If the machine tool abnormality diagnosis device (300_1 to 300_N) determines whether the maximum value of the vibration signal of the acceleration sensor corresponds to the reference value or more, the first condition, whether the maximum value corresponds to a specific value less than the reference value by a specific number of times. When the second condition or both the first and second conditions are satisfied, a detailed diagnostic analysis is performed on the vibration signal of the acceleration sensor.

To this end, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool perform signal processing (eg, Fast Fourier Transform (FFT)) on the vibration signal to extract a natural frequency. It is possible to check whether or not the monitored devices 200_1 to 200_N are abnormal by comparing the natural frequency and the processing frequency extracted through the above process.

Through FFT analysis, the natural frequencies of the top 5th or higher order are obtained, and these are calculated as 1,2,3, … of the tool machining frequency. Compared to the nth harmonic, if the same frequency exists, the tool judges that normal processing has been performed and a normal signal has been received.

That is, after calculating the difference frequency between the natural frequency and the processing frequency for each tool, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool may check whether the monitored devices 200_1 to 200_N are normal according to the difference frequency.

The apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool continuously and repeatedly perform the signal acquisition and initial signal analysis processes until all normal signals are received for each pre-input tool or an end signal is received. Here, the end signal means when a valid signal is not continuously received for more than 2 seconds or a predetermined time inputted in advance for each processing situation, and refers to a situation in which one processing process is ended.

In one embodiment, the device for diagnosing abnormalities in the machine tool (300_1 to 300_N) is the same as the previously received information of the monitoring target device (200_1 to 200_N) and the information obtained through the above-described analysis process, or a specific data check result for each time interval If the data analysis condition is not satisfied continuously for more than this time, it is determined that an end signal has been received.

In this case, the specific time may be changed by the user, and when the data analysis condition is not satisfied, it may mean a case of an abnormal standby situation in which there is no vibration of the devices to be monitored (200_1 to 200_N).

As described above, when it is determined that an end signal is received, the device for diagnosing abnormalities in the machine tool (300_1 to 300_N) changes from the signal acquisition mode to the diagnosis mode, and displays the diagnosis result of the monitoring target device (200_1 to 200_N) through the diagnosis mode. After printing, change to standby mode.

5 is a block diagram illustrating an internal structure of an apparatus for diagnosing an abnormality in a machine tool according to an embodiment of the present invention.

Referring to FIG. 5 , the device for diagnosing whether or not there is an abnormality in the machine tool 300 includes a machine tool basic information receiver 310, a processing frequency generator 320, a machine tool abnormality diagnosis unit 330, a storage unit 340, and a control unit. (350).

The machine tool basic information receiving unit 310 receives machine tool basic information from a user or monitoring target devices 200_1 to 200_N. In this case, the machine tool basic information may include the number of revolutions of the tool, the number of blades of the tool, the start point of machining, the machining time, and the like.

In one embodiment, the machine tool basic information receiving unit 310 provides a machine tool basic information input procedure through a display panel and receives the machine tool basic information through the machine tool basic information input procedure.

In another embodiment, the machine tool basic information receiver 310 may receive machine tool basic information from the monitoring target devices 200_1 to 200_N. To this end, external control devices that control the monitored devices (200_1 to 200_N) and machine tool abnormalities are diagnosed in different ways depending on the type of external control devices (not shown) that control the monitored devices (200_1 to 200_N). Devices 300_1 to 300_N are connected by wire (eg, RS-485).

As described above, in order for the external control device that controls the monitoring target devices 200_1 to 200_N and the machine tool basic information receiving unit 310 to be wired, the machine tool basic information receiving unit 310 is the monitoring target device 200_1 to 200_N Different types of communication ports corresponding to external control devices that control may be formed.

The processing frequency generation unit 320 generates a processing frequency using the machine tool basic information received from the machine tool basic information receiving unit 310 . In one embodiment, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool may generate the machining frequency using [Equation 1] above.

That is, the machining frequency generation unit 320 calculates the machining frequency by using the number of tool rotations (Num_turn) and the number of tool blades (Num_blade) among the basic information of the machine tool, and provides it to the machine tool abnormality diagnosis unit 330 .

Therefore, the machine tool abnormality diagnosis unit 330 uses the processing frequency and the vibration signal received from the acceleration sensors 210_1 to 210_N formed in each of the monitoring target devices 200_1 to 200_N to be monitored (200_1 to 200_N). ) can be diagnosed.

Upon receiving the initial signal analysis request signal from the control unit 350, the machine tool abnormality diagnosis unit 330 divides the vibration signal of the acceleration sensor stored in the storage unit 340 by a predetermined time interval and performs initial signal analysis. For example, the predetermined time interval is 0.5 seconds, but may be changed according to user manipulation according to process conditions.

Then, upon receiving the detailed analysis request signal from the control unit 350, the machine tool abnormality diagnosis unit 330 determines whether the maximum value of the vibration signal of the acceleration sensor corresponds to the reference value or more, the first condition, specific After checking whether the second condition or whether both the first and second conditions are satisfied for whether the maximum value corresponds to a specific value less than or equal to the reference value as many times as possible, an initial signal analysis result is generated and then provided to the control unit 350 .

For example, the machine tool abnormality diagnosis unit 330 sets the maximum reference value to 0.1g and the continuous repetition condition of the level value to 0.07g 10 times or more within 0.1 second, and for the vibration signal of the acceleration sensor. Whether the maximum value is greater than or equal to the reference value or a value of a certain level less than or equal to a certain level is determined as a starting condition for data analysis when continuous repetition of a certain level occurs at the same time. At this time, the maximum reference value and level value. The criteria (or/and) of continuous repetition conditions and analysis start conditions can be adjusted by the user according to process conditions.

If the machine tool abnormality diagnosis unit 330 determines whether the maximum value of the vibration signal of the acceleration sensor is equal to or greater than the reference value, the first condition is whether the maximum value corresponds to a specific value equal to or less than the reference value by a specific number of times. An initial signal analysis result is generated by checking whether the second condition or both the first and second conditions are satisfied.

Meanwhile, upon receiving a detailed analysis request signal from the control unit 350, the machine tool abnormality diagnosis unit 330 executes a detailed analysis.

First, the machine tool abnormality diagnosis unit 330 extracts a natural frequency by performing signal processing (eg, Fast Fourier Transform (FFT)) on the vibration signal. It is possible to check whether the monitoring target devices 200_1 to 200_N are abnormal by comparing the natural frequency extracted through the above process and the processing frequency received from the processing frequency generator 320 .

That is, the machine tool abnormality diagnosis unit 330 calculates the difference frequency between the natural frequency and the processing frequency received from the processing frequency generator 320, and then determines whether or not the monitoring target devices 200_1 to 200_N are normal according to the difference frequency. can be checked.

The machine tool abnormality diagnosis unit 330 continuously and repeatedly performs the signal acquisition and initial signal analysis processes until an end signal is received.

In one embodiment, the machine tool abnormality diagnosis unit 330 determines whether the previously received information of the monitored devices 200_1 to 200_N and the information obtained through the above-described analysis process are the same or as a result of checking the data for each time interval for a specific time or longer. If the data analysis condition is not continuously satisfied, it is determined that an end signal has been received.

In this case, the specific time may be changed by the user, and when the data analysis condition is not satisfied, it may mean a case of an abnormal standby situation in which there is no vibration of the devices to be monitored (200_1 to 200_N).

The controller 350 enters a standby mode after receiving basic machine tool information from the machine tool basic information receiving unit 310 . The control unit 350 receives vibration signals for a certain period of time from the monitoring target devices 200_1 to 200_N in the standby mode, and then uses the vibration signals to determine whether a vibration signal equal to or greater than a specific value is generated.

Thereafter, when the standby mode is switched to the signal acquisition mode, the control unit 350 controls the vibration signals of the acceleration sensors received from the monitoring target devices 200_1 to 200_N to be stored in the storage unit 340 .

In one embodiment, the controller 350 may switch from the standby mode to the signal acquisition mode when receiving a signal representing the start of one process of the machine tool in the standby mode.

The signal that represents the start of a process means the shock vibration that a workpiece is placed in the machine tool and the machine door is closed, or the shock vibration that restarts the processing motor that had stopped after the previous process. When these signals are received, the device switches to the signal acquisition mode. . In the signal acquisition mode, the device recognizes that a new machining process has started and starts to determine whether a valid signal (i.e., an actual machining signal) has been received.

In the signal acquisition mode, the control unit 350 provides an initial signal analysis request signal for the vibration signal of the acceleration sensor stored in the storage unit 340 to the machine tool abnormality diagnosis unit 330 when the controller 350 is switched to the signal acquisition mode. Accordingly, the machine tool abnormality diagnosis unit 330 may analyze the vibration signal of the acceleration sensor stored in the storage unit 340 according to the initial signal analysis request signal.

Then, the control unit 350 provides a detailed analysis request signal to the machine tool abnormality diagnosis unit 330 according to the initial signal analysis result received from the machine tool abnormality diagnosis unit 330 .

That is, when the initial signal analysis result satisfies the first condition, the second condition, or both the first and second conditions, the control unit 350 provides a detailed analysis request signal to the machine tool abnormality diagnosis unit 330. .

The control unit 350 provides a notification through a notification unit (not shown) based on the diagnosis result of the machine tool abnormality received from the machine tool abnormality diagnosis unit 330 so that the monitoring target devices 200_1 to 200_N receive an abnormal situation. It can notify the outside that this has occurred or provide a control signal for follow-up control in the event of an abnormal occurrence.

6 is a flowchart for explaining an embodiment of a method for diagnosing whether a machine tool is abnormal according to the present invention.

Referring to FIG. 6 , when machine tool abnormality diagnosis apparatus 300 receives machine tool basic information (ie, tool specifications and operating conditions used in a process) from a user or a device to be monitored, it enters a standby mode (step S410). ).

For example, the apparatus 300 for diagnosing abnormalities in the machine tool may enter a standby mode when basic machine tool information is received from a user or a device to be monitored through a process as shown in FIG. 7 . In this case, the machine tool basic information may include the number of revolutions of the tool, the number of blades of the tool, the start point of machining, the machining time, and the like.

In one embodiment, the apparatus 300 for diagnosing whether or not there is an abnormality in the machine tool provides a basic machine tool information input procedure through a display panel as shown in FIG. 7 and receives basic machine tool information through the machine tool basic information input procedure. .

When receiving a signal representing the start of a process in the standby mode, the apparatus 300 for diagnosing abnormalities in the machine tool switches from the standby mode to the signal acquisition mode (step S420).

That is, the apparatus 300 for diagnosing abnormalities in the machine tool receives the vibration signal as shown in FIG. 9 in the standby mode, and continuously performs only a repetitive task of checking whether or not the vibration signal exceeds a specific value in contrast to a general situation. At this time, the apparatus 300 for diagnosing abnormalities in the machine tool may also perform noise removal processes such as spike removal and filtering.

When receiving a signal representing the start of a process in the standby mode, the apparatus 300 for diagnosing abnormalities in the machine tool switches from the standby mode to the signal acquisition mode (step S430).

The signal representing the start of the process refers to the shock vibration of closing the machine door after the workpiece is placed in the machine tool or the shock vibration of restarting the processing motor that has stopped after the previous process. Upon receipt, the signal acquisition mode causes the device to recognize that a new machining process has started, and begins to determine whether a valid signal (i.e., an actual machining signal) has been received.

After storing the vibration signal of the acceleration sensor of FIG. 9 in a memory in the signal acquisition mode, the machine tool diagnosis apparatus 300 divides the vibration signal of the acceleration sensor of FIG. carry out For example, the predetermined time interval is 0.5 seconds, but may be changed according to user manipulation according to process conditions.

As described above, the apparatus 300 for diagnosing abnormalities in the machine tool switches to the detailed analysis mode according to whether a valid signal (ie, a real processing signal) is received in the process of performing the initial signal analysis (step S440).

In one embodiment of step S440, the apparatus 300 for diagnosing whether or not there is an abnormality in the machine tool is a first condition for whether the maximum value of the vibration signal of the acceleration sensor is greater than or equal to the reference value and the maximum value is less than or equal to the reference value by a specific number of times. When the second condition or both the first condition and the second condition are satisfied, the detailed diagnosis mode for the vibration signal of the speed sensor is switched.

To this end, the apparatus 300 for diagnosing abnormalities in the machine tool extracts a natural frequency by performing signal processing (eg, Fast Fourier Transform (FFT)) on the vibration signal. It is possible to check whether the monitoring target devices 200_1 to 200_N are abnormal by comparing the natural frequency extracted through the above process and the processing frequency of FIG. 10 .

Through FFT analysis, the natural frequencies of the top 5th or higher order are obtained, and these are calculated as 1,2,3, … of the tool machining frequency. Compared to the nth harmonic, if the same frequency exists, the tool judges that normal processing has been performed and a normal signal has been received.

The apparatus 300 for diagnosing abnormalities in the machine tool calculates a difference frequency between the natural frequency and the processing frequency for each tool, and then checks whether the monitored devices 200_1 to 200_N are normal according to the difference frequency.

Finally, the apparatus 300 for diagnosing abnormalities in the machine tool provides an external alarm, a notification message, and an external control function when the machining process ends (ie, when a normal signal for each tool is received or an end signal is received).

More specifically, the device for diagnosing whether or not there is an abnormality in the machine tool (300_1 to 300_N) is the same as the previously received information of the monitoring target device (200_1 to 200_N) and the information acquired through the above-described analysis process, or as a result of checking the data for each time interval at a specific time If the data analysis condition is not satisfied continuously, it is determined that an end signal has been received.

In this case, the specific time may be changed by the user, and when the data analysis condition is not satisfied, it may mean a case of an abnormal standby situation in which there is no vibration of the devices to be monitored (200_1 to 200_N).

As described above, when it is determined that an end signal is received, the apparatuses 300_1 to 300_N for diagnosing abnormalities in the machine tool change from the signal acquisition mode to the diagnosis mode as shown in FIG. 8, and the monitoring target devices 200_1 to 200_N After outputting the diagnosis result, it changes to standby mode.

In the diagnostic screen of FIG. 8, if each tool on the horizontal axis is normal, the result value is displayed in the blue normal area, and if it is abnormal, the result value is displayed in the upper and lower red area. At this time, the diagnosis screen of FIG. 8 may be displayed for a time set by the user.

In case of an abnormality, it also alerts the field worker to take action through an alarm buzzer, alarm, etc. Also, if the monitoring target device is configured with an automated system that automatically supplies the workpiece, a control signal that stops the automatic supply device send out

In addition, sometimes, depending on the type of machining tool, machining conditions or field conditions, a machining frequency other than the frequency matching the above [Equation 1] may occur. It is possible to directly input and use it for diagnosis, but this is very cumbersome and inefficient for the operator.

In the present invention, the value of the first main frequency band is compared with the value of the last subsection, and when this value is different, it is automatically regarded as a tool breakage and notified to the user through the diagnosis screen of FIG. 8 .

The present invention accurately recognizes the machining state and improves the accuracy of tool damage diagnosis during the entire time period from the start of machining to the end of machining.

Specifically, in general, machining of a conventional numerical control (NC) machine tool is performed by dividing the entire depth into small sections several times rather than machining the entire depth at once. (For example, a tap with a depth of 8 mm is divided into 4 small sections of 2 mm each) This means that the machining tool performs vertical movement several times during machining.

11 illustrates an example of a signal of an acceleration sensor and a processing frequency during a processing section according to an embodiment of the present invention.

Specifically, FIG. 11 shows signals of an acceleration sensor while machining a total of four screw taps, and is an enlarged view of signals while machining a third screw tap. Here, the orange line represents the most important frequency band calculated through FFT frequency spectrum analysis.

Referring to FIG. 11 , in the middle of machining one screw tap, the machining tool performed vertical feed a total of three times, and it can be seen that a differentiated frequency signal is generated at this time.

It is inefficient to continuously scan all processing frequencies during the entire processing section, and there is a high possibility of misdiagnosis due to noise.

Therefore, in the present invention, it is intended to be more efficient and to reduce the possibility of misdiagnosis by using only one subsection after the end of the last vertical transfer instead of the entire processing section for diagnosis.

A conventional method for diagnosing an abnormality in a machine tool was a method of continuously scanning a processing frequency during the entire process time. This method is inefficient, and there is a high possibility of misdiagnosis due to noise.

In addition, sometimes, depending on the type of machining tool, machining conditions or field conditions, a machining frequency other than the frequency matching the above [Equation 1] may occur. It is possible to directly input and use it for diagnosis, but this is very cumbersome and inefficient for the operator.

In the present invention, when the value of the first main frequency band is compared with the value of the last subsection, when this value is different, it is automatically regarded as a tool breakage, and the user can be alarmed or control-linked to a nearby device.

Therefore, the present invention can reduce the time required while improving diagnosis accuracy, and enable efficient diagnosis.

In addition, in the conventional machine tool abnormality diagnosis, there is a problem that server overload may occur because one main server 10 performs all of these analyzes and controls.

On the other hand, in the present invention, by using only the last frequency signal or data from after the tool machining is finished instead of the entire process time, the above conventional problems are solved more efficiently and the possibility of misdiagnosis is reduced.

12 is a perspective view illustrating an apparatus for diagnosing whether a machine tool is abnormal according to an embodiment of the present invention.

Referring to FIG. 12 , the apparatus 300 for diagnosing abnormalities in the machine tool includes an antenna 380 for wireless communication, a sensor connection unit 360 and a notification unit 370 .

The antenna 380 for wireless communication enables data transmission and reception with the main server 100 and the monitoring target devices 200_1 to 200_N even wirelessly.

The sensor connection unit 360 is connected to the acceleration sensors of the monitoring target devices 200_1 to 200_N and receives vibration signals from the acceleration sensors.

These vibration signals are used for initial analysis and detailed diagnosis analysis. In the initial signal analysis, the first condition for whether the maximum value corresponds to a reference value or more, and the condition for whether the maximum value for a specific number of times corresponds to a specific value less than or equal to the reference value It is checked whether condition 2 or both the first condition and the second condition are satisfied, and a detailed diagnosis analysis is performed according to the confirmation result.

Therefore, when the machine tool abnormality diagnosis apparatus 300 performs signal processing (eg, FFT (Fast Fourier Transform)) on the vibration signal during the detailed diagnosis analysis, and the natural frequency is extracted, the natural frequency and the pre-calculated processing Depending on the frequency comparison result, it is possible to check whether an abnormal situation has occurred in the monitoring target devices (200_1 to 200_N).

The apparatus 300 for diagnosing an abnormality in the machine tool may inform the outside that an abnormal situation has occurred in the monitored devices 200_1 to 200_N by providing a notification through the notification unit 370 based on the diagnosis result of the abnormality in the machine tool.

Although described by the limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art can make various modifications and variations from these descriptions. Therefore, the spirit of the present invention should be grasped only by the claims described below, and all equivalent or equivalent modifications thereof will be said to belong to the scope of the spirit of the present invention.

100: main server,
200_1~200_N: Devices to be monitored,
300_1~300_N: Machine tool abnormality diagnosis device
310: machine tool basic information receiver,
320: processing frequency generator,
330: machine tool abnormality diagnosis unit,
340: storage unit
350: control unit
400_1~400_N: Control device

Claims (7)

A main server capable of controlling a plurality of monitoring target devices;
a receiving unit including a communication port connectable by wire in order to receive basic machine tool information from the monitoring target device;
a processing frequency generation unit generating a processing frequency using the machine tool basic information received from the machine tool basic information receiving unit;
a storage unit for storing a vibration signal of an acceleration sensor formed in the monitoring target device;
According to the initial signal analysis request signal, the vibration signal of the acceleration sensor stored in the storage unit is divided into predetermined time intervals to perform initial signal analysis, and then an initial signal analysis result is generated. According to the initial signal analysis result, a detailed analysis request signal is generated. When received, a machine tool abnormality diagnosis unit for diagnosing an abnormality of the monitoring target device by comparing a previously calculated processing frequency and a vibration signal of an acceleration sensor;
After calculating the difference between the natural frequency and the processing frequency of each machine tool, the diagnosis unit checks whether the monitoring target device is normal according to the frequency, and the information of the monitoring target device received in advance and the information obtained through the above analysis process are checked. a diagnosis unit that determines that an end signal is obtained when data analysis conditions are not satisfied continuously for a specific period of time or longer as a result of checking data for the same or time interval;
When the machine tool basic information is received from the machine tool basic information receiving unit, noise elimination processes such as spike removal and filtering may be performed together, and a standby mode is entered to check whether a vibration signal exceeding a specific value is generated, and the standby mode When receiving a signal representing the start of the process, it switches to the signal acquisition mode,
In the signal acquisition mode, after controlling the vibration signal to be stored in the storage unit, an initial signal analysis request signal for the vibration signal of the acceleration sensor stored in the storage unit is provided to the machine tool abnormality diagnosis unit, and the initial signal analysis A control unit for providing a detailed analysis request signal to the machine tool abnormality diagnosis unit according to the result,
A machine tool abnormality diagnosis system, characterized in that it can control a plurality of monitoring target devices that display an alarm to the operator when the system is abnormal and generate a control signal to stop the automatic supply device.
According to claim 1,
The machine tool abnormality diagnosis unit
When an initial signal analysis request signal is received from the control unit, a first condition for whether the maximum value of the vibration signal of the acceleration sensor corresponds to a reference value or more, whether the maximum value of a specific number of times corresponds to a specific value equal to or less than the reference value Machine tool abnormality diagnosis system, characterized in that for checking whether the second condition or both the first condition and the second condition are satisfied. According to claim 1,
The machine tool abnormality diagnosis unit
After extracting a natural frequency by performing signal processing on the vibration signal according to the detailed analysis request signal, comparing the natural frequency and the processing frequency received from the processing frequency generator to check whether the monitoring target device is abnormal Machine tool abnormality diagnosis system, characterized in that.
In the method for diagnosing whether a machine tool is abnormal or not executed in a machine tool abnormality diagnosis device,
When basic machine tool information is received from a user or a device to be monitored, noise elimination processes such as spike elimination and filtering may be performed together, and entering a standby mode to check whether a vibration signal exceeding a specific value is generated;
switching from the standby mode to a signal acquisition mode when receiving a signal representing the start of a process in the standby mode;
performing an initial signal analysis by dividing the vibration signal of the acceleration sensor stored in a memory in the signal acquisition mode by a predetermined time interval;
switching to a detailed analysis mode according to whether a valid signal is received during the initial signal analysis;
Comparing the pre-calculated processing frequency and the vibration signal of the acceleration sensor in the detailed analysis mode; and
Diagnosing whether or not the monitoring target device is abnormal according to the comparison result; includes,
After calculating the difference between the natural frequency and the processing frequency for each machine tool, check whether the monitoring target device is normal according to the frequency, and if the previously received monitoring target device information and the information obtained through the above analysis process are the same or time As a result of checking the data by section, if the data analysis condition is not satisfied continuously for more than a certain time, it is judged as an end signal.
If the system is abnormal, an alarm is displayed to the operator and a control signal is generated to stop the automatic supply device,
Whenever the process of the monitoring target device is completed, the main server receives result data for the corresponding process from the machine tool abnormality diagnosis device, controls the monitoring target device according to the received data, and controls a plurality of monitoring target devices. A method for diagnosing machine tool abnormality, characterized in that it can be done.
According to claim 4,
The step of entering the standby mode when basic machine tool information is received from the user or the monitoring target device includes the step of entering the standby mode when tool specifications and operating conditions used in the process are received Diagnosis method
According to claim 4,
In the signal acquisition mode, the step of dividing the vibration signal of the acceleration sensor stored in the memory by a predetermined time interval and performing the initial signal analysis includes a first condition and specific determination of whether the maximum value of the vibration signal of the acceleration sensor is equal to or greater than a reference value. A method for diagnosing whether a machine tool is abnormal, comprising the step of checking whether the second condition or both the first and second conditions are satisfied as many times as the maximum value corresponds to a specific value less than or equal to the reference value.
According to claim 6,
In the process of performing the initial signal analysis, the step of switching to the detailed analysis mode according to whether or not a valid signal is received is to extract a natural frequency by performing signal processing on the vibration signal according to the confirmation result, and then extract the natural frequency and Comparing processing frequencies pre-calculated based on the machine tool basic information; And diagnosing whether or not the machine tool is abnormal according to the comparison result.
A method for diagnosing a machine tool abnormality, characterized in that

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