KR20200111956A - Apparatus and method for monitoring load - Google Patents

Abstract

Provided are a load monitoring apparatus and a method thereof. The load monitoring apparatus comprises: an input interface configured to receive each measurement signal from a plurality of load sensors provided in a press apparatus; a controller configured to calculate a master signal based on the measurement signal and monitor at least one of the measurement signal and the master signal; and an output interface configured to output at least one of the measurement signal, the master signal, and a determination result. The controller may determine whether at least one of the measurement signal and the master signal deviates from a predetermined determination area on a graph according to a load and at least one of a pressing distance and a pressing time of the press apparatus. An object of the present invention is to provide the load monitoring apparatus capable of easily detecting process errors at a lower cost and the method thereof.

Description

Load monitoring device and method {APPARATUS AND METHOD FOR MONITORING LOAD}

The present invention relates to a load monitor, and more particularly, to an apparatus and method for monitoring a load applied to an object during a pressing process of a press device.

In general, in the pressurization process using a press device, a load monitoring device for measuring a load applied to a work object is used for quality control.

A conventional load monitoring device supplies power to a load sensor and measures and displays its output. When an output outside a preset range is measured, an internal relay is operated to operate an alarm device connected to the load monitoring device. Is composed. Therefore, in the case of a conventional load monitoring device, it is difficult to cope with the situation in which the accuracy of the product is deteriorated due to an error and/or malfunction due to abrasion of drive system parts, since it simply determines whether there is an abnormality based on the output range.

In order to solve this problem, Korean Laid-Open Patent Publication No. 10-2017-0115276 (published on December 14, 2017) "Press with a press pressure monitoring function" uses a calibration sensor to deteriorate press parts, etc. And reflecting changes in environmental conditions, automatically calibrating monitoring and press control standards, and presenting a calibration guide of the press through measured physical quantities to maintain the convenience of the press operator and the accuracy of precision machining work. However, this method can also cope with the abnormality of the press part, but it is still difficult to cope with the abnormality of product quality caused by process errors caused by load balance abnormality and overload.

An object of the present invention is to provide a load monitoring device and method capable of easily detecting a process error at a lower cost.

Another technical object of the present invention is to provide a load monitoring device and method capable of detecting an abnormality in a product more quickly.

According to an aspect of the present invention, a load monitoring device includes an input interface configured to receive measurement signals from a plurality of load sensors provided in a press device, respectively, and calculate a master signal based on the measurement signal, and the measurement signal and A controller configured to monitor at least one of the master signals and an output interface configured to output at least one of the measurement signal, the master signal, and the determination result, wherein the controller comprises at least one of the measurement signal and the master signal To determine whether or not is out of the preset determination area on the graph according to the load and at least one of the pressing distance and pressing time of the press device I can.

According to one aspect, the load sensor may be an S-shaped load cell.

According to another aspect, the controller may determine whether a balance value between loads measured by the plurality of load sensors is out of a threshold range based on at least one of the measurement signal and the master signal.

According to another aspect, when at least one of the measurement signal and the master signal is out of a preset load range for each preset pressing distance on the graph, the controller may determine that it is out of the corresponding determination area.

According to another aspect, the controller may generate an abnormality occurrence signal when the pressing time exceeds a preset time range within a preset pressing distance on the graph.

According to another aspect, the controller may generate an abnormality occurrence signal when the pressing time exceeds a preset time range within a preset pressing distance on the graph.

According to another aspect, the controller may generate an abnormality occurrence signal when a variation of at least one of the measurement signal and the master signal exceeds the predetermined variation within a predetermined pressing distance on the graph.

According to another aspect, the load monitoring device may further include a database storing history information based on at least one of the measurement signal, the master signal, and the determination result.

According to another aspect of the present invention, a method of monitoring a mode by a load monitoring device includes receiving measurement signals from a plurality of load sensors provided in a press device, respectively, calculating a master signal based on the measurement signal, and calculating the measurement signal. And monitoring at least one of the master signals, determining whether at least one of the measurement signal and the master signal deviates from a predetermined determination area on a graph according to at least one of a pressing distance and a pressing time of the press device and a load. It may include determining, and outputting at least one of the measurement signal, the master signal, and the determination result.

According to the present invention, since it is possible to detect a process error without adding additional equipment to an existing press device, defective products can be effectively detected at a lower cost.

Further, according to the present invention, since it is possible to determine whether there is an abnormality only in a predetermined determination area, a defective product can be detected more quickly.

1 is a block diagram showing a load monitoring device according to an embodiment of the present invention.
2 is a view for explaining the position of the load sensor installed in the press device according to an embodiment of the present invention.
3 to 5 are diagrams showing output screens of a load monitoring device according to an embodiment of the present invention.
6 is a flow chart showing a load monitoring method according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the embodiments of the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

1 is a block diagram showing a load monitoring device according to an embodiment of the present invention.

Referring to FIG. 1, a load monitoring device 100 according to an embodiment of the present invention may include an input interface 110, a controller 120, and an output interface 130.

The input interface 110 is connected to a plurality of load sensors 10, 11, and 14 provided in the press device, and is configured to receive measurement signals from each of the load sensors 10, 11, and 14 through different channels. I can. Here, the load sensors 10, 11, and 14 may be configured as an'S'-shaped load cell. The load cell can output an electrical signal by converting the deformation of the elastic body caused by the load into a change in resistance through a strain gauge.

The controller 120 may calculate a master signal based on the measurement signals input through the input interface 110. In addition, the controller 120 may monitor at least one of the measurement signal and the master signal input through the input interface 110 to determine whether the corresponding signal deviates from a predetermined determination area. Here, the determination region may be set in the form of a band, a square, a slope range, etc. on a graph according to a load and at least one of a pressing distance and a pressing time of the press device. The master signal may be derived based on a sum value or an average value of a plurality of measurement signals input through the input interface 110.

For example, the controller 120 determines whether at least one of the plurality of measurement signals is out of the determination area, or a balance (load balance value) between loads applied to each axis of the press device is critical based on the master signal. Whether it is out of range can be determined. If at least one of the plurality of measurement signals is out of the determination area or the load balance value is out of the threshold range, the controller 120 determines that an error has occurred and controls the error occurrence signal to be output through the output interface 130 can do.

The output interface 130 may be configured to output a measurement signal input from the plurality of load sensors 10, 11, and 14, a master signal generated by the controller 120, a determination result, and the like. To this end, the output interface 130 may be implemented as a display device, a communication device, or the like.

Meanwhile, the controller 130 may generate information on a measurement history based on at least one of the measurement signal, the master signal, and the determination result, and store it in a database. The database may be provided in the load monitoring device 100 or may be provided in a separate external device as needed.

2 is a view for explaining a load sensor installed in the press device according to an embodiment of the present invention.

As an example, as shown in FIG. 2, four load sensors 21, 22, 23, and 24 may be connected to the load monitoring device according to the present invention. Referring to Figure 2, four load sensors (21, 22, 23, 24) to measure the load applied to one side of the work table 200 provided in each press device, each edge of the work table 200 It can be provided on the located axis. In this case, the load monitoring device may determine a load balance abnormality during the pressing process based on signals measured by each of the load sensors 21, 22, 23, and 24.

For example, in the state that the lower and upper limits of the load balance are set to 80% and 120%, respectively, the signals measured by the first load sensor 21 to the third load sensor 23 represent 400kgf, and the fourth load sensor ( When the signal measured in (24) indicates 440kgf, the load monitoring device may determine that there is no abnormality in the load balance because the average value of the four measurement signals is located within the critical range. However, in a state in which the lower and upper limits of the load balance are set to 80% and 120%, respectively, the signals measured by the first load sensor 21 to the third load sensor 23 represent 300kgf, and the fourth load sensor 24 When the signal measured at indicates 500kgf, the load monitoring device may determine that an abnormality has occurred in the load balance because the average value of the four measurement signals is out of the threshold range even if all four measurement signals are located within the determination area. In this case, the load monitoring device may output a signal indicating that an abnormality occurs in the load balance through the output interface.

3 to 5 are diagrams showing output screens of a load monitoring device according to an embodiment of the present invention. Hereinafter, a determination area according to an embodiment of the present invention will be described in more detail with reference to FIGS. 3 to 5.

First, referring to FIG. 3, the load monitoring device according to the present invention sets a section of a pressing distance of 50 mm to 150 mm as a first determination region as a determination region for a master signal 300 as an example, and a pressing distance of 300 mm to 400 mm. The section of can be set as the second judgment area. In this case, as shown in FIG. 3, the determination condition for the load in the first determination region and the determination condition for the load in the second determination region may be set differently from each other. As an example, the load monitoring apparatus may set the determination condition for the load in the first determination region to 350kgf to 550kfg, and the determination condition for the load in the second determination region to be 300kfg to 500kfg.

In general, during the pressurization process, about 700 pieces of data are input to the load monitoring device during a sampling time of 1 to 2 ms. Therefore, it is difficult to detect the abnormality in real time because it takes a lot of time to determine the abnormality in the case of determining the abnormality of all input data. Therefore, the load monitoring apparatus according to the present invention calculates the master signal 300 based on a plurality of measurement signals, sets the judgment area only for the pressing distance where the process error occurs mainly, while setting the load required in each judgment area. By setting the upper and lower limits separately, it is possible to detect various abnormal situations including load balance errors more quickly.

Meanwhile, as another example, the load monitoring device may set a section between the maximum load lower limit and the maximum load upper limit 330 as the determination area. In this case, the load monitoring device may determine whether the total load measured by the plurality of load sensors exceeds the maximum load lower limit and/or the maximum load upper limit 330. Here, the master signal 330 may be derived by summing measurement signals input from a plurality of load sensors.

As another example, the load monitoring apparatus may set a band between the first critical section 340 and the second critical section 350 as the determination area. In this case, the load monitoring apparatus may determine whether a plurality of measurement signals and/or master signals deviate from the band. Here, the band may be derived based on an average value of signals input through an input interface when the process is normally completed when the same process as the current process is performed. The information on the band may be previously stored in a database, and may be automatically input when a corresponding process is performed.

As another example, the load monitoring device may determine whether an abnormality occurs based on the pressing distance according to the pressing time. In this case, the load monitoring device may determine whether the pressing time is out of a preset time range within a preset pressing distance. If, within a predetermined time, the pressing distance does not reach a predetermined distance or exceeds a predetermined section, the load monitoring device may determine that an abnormality has occurred in the process.

As another example, the load monitoring device may determine whether an abnormality has occurred based on the amount of fluctuation of the slope of the master signal and/or the measurement signal. In this case, the load monitoring device may determine whether the variation amount of the master signal and the measurement signal deviates from the predetermined variation amount within a preset pressing distance. For example, the fluctuation amount of the slope may be defined as an amount by which the slope of the signal changes in the first determination region 310 and/or the second determination region 320.

As another example, the load monitoring device may determine whether an abnormality occurs in the load balance during the pressing process based on the master signal and/or the measurement signal. For example, the lower limit and the upper limit of the load balance may be set to 80% and 120%, respectively, and when out of this range, the load monitoring device may determine that an abnormality has occurred in the balance between loads.

The load monitoring apparatus according to the present invention can perform the above-described various judgments in parallel. To this end, the load monitoring device may set an upper load limit, a lower load limit, an upper distance limit, and a lower distance limit for measurement signals and/or master signals input from a plurality of load sensors through an interface as illustrated in FIG. 4. In addition, for the first judgment area (condition 1 judgment) and the second judgment area (condition 2 judgment), you can set the start position, the end position, the load upper limit and the load lower limit, respectively, and you can also set the load balance upper limit and the load balance lower limit. . These set values may be set differently according to the applied process. Accordingly, setting values as shown in FIG. 4 may be stored in a database according to a process to be performed and then automatically loaded when performing a process, and may be modified and/or changed by a user as needed.

Meanwhile, FIG. 5 illustrates a screen displayed through an output interface when a predetermined process is performed, for example. As shown in Fig. 5, during the pressurization process, the load monitoring device displays the sensor detection value and a real-time graph, and at the same time, determines whether the maximum load, the abnormal distance, the first determination area, the second determination area, and the load balance abnormality Each result can be displayed. If an abnormality is detected in any one of the determination results, the load monitoring device may notify that an abnormality has occurred in the determination through an indicator corresponding to each determination object in the interface of FIG. 5.

6 is a flow chart showing a load monitoring method according to an embodiment of the present invention.

Referring to FIG. 6, the load monitoring device may receive each measurement signal from a plurality of load sensors provided in the press device through an input interface (S610). In this case, the load monitoring apparatus may determine whether or not each of the received measurement signals is abnormal, while calculating a master signal based on the measurement signal, and monitoring each signal (S620). And, if an abnormality is detected in any one based on the measurement signal and/or the master signal (S630), an abnormality occurrence signal indicating that an abnormality has occurred in the determination is generated, and the abnormal state is sent to the user through the output interface. It may be notified that the occurrence has occurred (S640). If an abnormality is not detected as a result of the determination for each condition, at least one of the measurement signal, the master signal, and the determination result may be output through an output interface.

For this, as an example, the load monitoring device may primarily perform a determination on the master signal. If the master signal satisfies the judgment conditions for both the first judgment area and the second judgment area, i.e., if the master signal is located within the first judgment area and the second judgment area, the load monitoring device secondarily measures a plurality of measurements. For each signal, it can be determined whether or not each determination condition is satisfied. Here, the first determination region and the second determination region may be set in a square shape on a graph according to a pressing distance and a load of the press device, as shown in FIGS. 3 and 5. For example, in the case of the press pressing process, the determination region may include a first determination region having a pressing distance of 50 mm to 150 mm and a second determination region having a pressing distance of 300 mm to 400 mm. In this case, the determination condition for the load in the first determination region may be 350kgf to 550kfg, and the determination condition for the load in the second determination region may be 300kfg to 500kfg.

The load monitoring device can generate history information for the process based on the determination result derived through this process, the measurement signal input to the load monitoring device, and the master signal calculated by the load monitoring device, and store it in the database. have.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the technical field to which the present invention pertains can make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

10, 11, 14: load sensor
100: load monitoring device
110: input interface
120: controller
130: output interface

Claims (15)

An input interface configured to receive each measurement signal from a plurality of load sensors provided in the press device;
A controller configured to calculate a master signal based on the measurement signal and monitor at least one of the measurement signal and the master signal; And
And an output interface configured to output at least one of the measurement signal, the master signal, and the determination result,
The controller,
And determining whether at least one of the measurement signal and the master signal deviates from a predetermined determination area on a graph according to a load and at least one of a pressing distance and a pressing time of the pressing device. The method of claim 1,
The load monitoring device, characterized in that the load sensor is an S-shaped load cell. The method of claim 1,
The controller,
Load monitoring device, characterized in that the master signal is derived by summing the measurement signals input from the plurality of load sensors. The method of claim 3,
The controller,
A load monitoring device, characterized in that it determines whether a balance value between loads measured by the plurality of load sensors is out of a threshold range based on at least one of the measurement signal and the master signal. The method of claim 1,
The controller,
When at least one of the measurement signal and the master signal is out of a preset load range for each preset pressing distance on the graph, it is determined that it is out of a corresponding determination area. The method of claim 1,
The controller,
A load monitoring device, characterized in that generating an abnormality occurrence signal when the pressing time exceeds a preset time range within a preset pressing distance on the graph. The method of claim 1,
The controller,
And generating an abnormality occurrence signal when a variation of at least one of the measurement signal and the master signal exceeds the predetermined variation within a preset pressing distance on the graph. The method of claim 1,
And a database storing history information based on at least one of the measurement signal, the master signal, and the determination result. In the mode monitoring method by the load monitoring device,
Receiving each measurement signal from a plurality of load sensors provided in the press device;
Calculating a master signal based on the measurement signal, and monitoring at least one of the measurement signal and the master signal;
Determining whether at least one of the measurement signal and the master signal deviates from a predetermined determination area on a graph according to a load and at least one of a pressing distance and a pressing time of the press device; And
Outputting at least one of the measurement signal, the master signal, and the determination result
Load monitoring method comprising a. The method of claim 9,
The monitoring step,
And derive the master signal by summing measurement signals input from the plurality of load sensors. The method of claim 10,
The determining step,
Determining whether a balance value between loads measured by the plurality of load sensors is out of a threshold range based on at least one of the measurement signal and the master signal; And
And generating an abnormality occurrence signal when the balance value between the loads exceeds the threshold range. The method of claim 9,
The determining step,
And determining whether at least one of the measurement signal and the master signal is out of a preset load range for each preset pressing distance on the graph. The method of claim 12,
The determining step,
And determining whether the pressing time is out of a preset time range within a preset pressing distance on the graph. The method of claim 13,
The determining step,
And determining whether a variation of at least one of the measurement signal and the master signal deviates from the predetermined variation within a predetermined pressing distance on the graph. The method of claim 9,
After the determining step,
And generating history information on the basis of at least one of the measurement signal, the master signal, and the determination result.

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