Monitoring sensor, sensor plate and communication control unit

Abstract

To monitor defect of a press machine accurately using radio data transmission.SOLUTION: A monitoring system for a press machine is provided with: a sensor unit that detects distortion generated at a predetermined site of the press machine; a communication control unit that uses a cam signal obtained from a cam mechanism as a reference for a time axis for extracting digital data relating to a distortion signal detected by the sensor unit, extracts the digital data with a predetermined time-bandwidth based on the cam signal, and transmits the extracted digital data by radio; and a monitoring device that receives the digital data transmitted from the communication control unit and monitors the press machine on the basis of the received digital data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a monitoring system for, for example, a press machine, a sensor plate suitable for use in the system, and a communication control unit. [Background technology]

[0002] The inventors have disclosed a system that can quickly and accurately estimate the occurrence of defective events caused by deterioration of the mold being set, and can contribute to minimizing the occurrence of defective products (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-126823 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a system, signals detected by a sensor are converted into digital data, and the digital data is transmitted to, for example, a personal computer (PC), which performs analysis of the digital data.

[0005] When trying to estimate the occurrence of a defect with high accuracy, the digital data that is A / D converted from the signal detected by the sensor becomes quite large, and the digital data also becomes large when the press is driven at high speed. Therefore, using wireless data transmission between the press and PC eliminates the need for wiring compared to using a wired connection, and can avoid the clutter and disconnections that come with wiring, but the data transmission capacity is smaller, resulting in inferior estimation accuracy.

[0006] In view of the above circumstances, an object of the present invention is to provide a monitoring system that can accurately monitor malfunctions in presses and the like using wireless data transmission. Another object of the present invention is to provide a sensor plate and a communication control unit that are suitable for use in such a system. [Means for solving the problem]

[0007] In order to achieve the above object, a monitoring system for a press machine according to one embodiment of the present invention comprises: The machine has a mechanism for moving a die using a cam mechanism, and is equipped with a sensor unit that detects distortion occurring at a predetermined location of a machine, such as a press machine; a communication control unit that uses a cam signal obtained from the cam mechanism as a time axis reference for extracting digital data related to the distortion signal detected by the sensor unit, extracts the digital data of a predetermined time band based on the cam signal, and transmits data related to the extracted digital data wirelessly; and a monitoring device that receives the data transmitted from the communication control unit and monitors the machine based on the received data.

[0008] According to this monitoring system, the digital data in a predetermined time band is extracted and data related to the extracted digital data is transmitted wirelessly, making it possible to accurately monitor malfunctions in press machines, etc., using wireless data transmission. In this case, a cam signal obtained from a cam mechanism synchronized with the punching operation of the press machine is used as the time base for extracting digital data related to the strain signal detected by the sensor unit, making it possible to accurately compare digital data from each cycle, thereby enabling accurate monitoring of malfunctions in press machines, etc.

[0009] A sensor unit according to one embodiment of the present invention comprises a flexible substrate having a MEMS strain sensor arranged on one side, a metal member having a recess to the bottom of which is attached an area of ​​the flexible substrate where the MEMS strain sensor is arranged, and a sealant that fills the recess and seals the area.

[0010] With this sensor unit, a recess is formed in a metal member, typically a metal plate or metal rod, and the area of ​​the flexible substrate where the MEMS strain sensor is located is attached to the bottom of the recess, and these are then sealed with a sealing material. In particular, the MEMS strain sensor is double-sealed, which prevents problems caused by oil or dust getting into the MEMS strain sensor even in environments where oil is splattered and the sensor is exposed to severe vibrations, such as in a press machine.

[0011] A communication control unit according to one embodiment of the present invention has a first input section that inputs an analog distortion signal detected by a machine having a mechanism for moving a mold using a cam mechanism, a second input section that inputs a cam signal from the cam mechanism of the machine, and an A / D conversion section that converts the analog distortion signal input to the first input section into digital data, extracts the digital data of a predetermined time band based on the cam signal input by the second input section from the digital data converted by the A / D conversion section, and electronically transmits the extracted digital data by radio.

[0012] This communication control unit extracts the digital data in a predetermined time band and transmits the extracted digital data wirelessly, making it possible to accurately monitor malfunctions in press machines, etc., using wireless data transmission. In this case, a cam signal obtained from a cam mechanism synchronized with the punching operation of the press machine, for example, is used as the time base for extracting digital data related to the strain signal detected by the sensor unit, making it possible to accurately compare digital data from each cycle, thereby enabling accurate monitoring of malfunctions in press machines, etc. [Effects of the Invention]

[0013] According to the present invention, malfunctions in a press or the like can be monitored with high accuracy using wireless data transmission.

[0014] The sensor unit according to the present invention can avoid problems caused by oil or dust entering the MEMS strain sensor, which is extremely vulnerable to external disturbances, even in environments where oil is splashed and the sensor is exposed to severe vibrations, such as in a press machine. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a block diagram showing a configuration of a monitoring system for a press machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of the sensor unit shown in FIG. [Figure 3] FIG. 3 is a top view of FIG. 2. [Figure 4] FIG. 3 is a block diagram showing the configuration of the flexible substrate shown in FIG. 2. [Figure 5] 2 is a block diagram showing the configuration of a communication control unit shown in FIG. 1. [Figure 6] 2 is a diagram showing a schematic diagram of the cam mechanism shown in FIG. 1 and digital data relating to a strain signal displayed by a PC. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] FIG. 1 is a block diagram showing the configuration of a monitoring system for a press machine according to one embodiment of the present invention.

[0018] As shown in FIG. 1, the monitoring system 100 includes a sensor unit 110, a communication control unit 120, and a PC 130 serving as a monitoring device.

[0019] The press machine 200 monitored by the monitoring system 100 typically performs a punching process. A tape-like metal material 300 is run over a die 210 having a hole 211 of a desired shape, and a die (punch) 220 corresponding to the hole 211 punches the metal material 300 from above to form a hole of the desired shape. The die (punch) 220 is driven vertically by a cam mechanism 230. The cam mechanism 230 has a shaft 231 as a driven contact to which the die (punch) 220 is attached below, and a cam 232 rotatably connected to the upper end of the shaft 231. A mechanism (not shown) for rotating the cam 232 operates in synchronization with a mechanism (not shown) for running the tape-like metal material 300, and is set so that the die (punch) 220 reaches the bottom dead center when the desired position on the tape-like metal material 300 coincides with the position of the hole 211 of the desired shape.

[0020] Typically, a cam switch 241 is provided at a position that is a predetermined angle θ before the position based on the bottom dead center of the cam 232, and a cam switch 242 is provided at a position that is a predetermined angle θ after the position based on the bottom dead center of the cam 232. These θ angles may be different. The cam switches 241 and 242 output an ON signal, for example, when the cam 232 passes the position where the shaft 231 is connected. In this embodiment, the cam switches 241 and 242 are located, for example, approximately 10° to 20° from the bottom dead center, but the present invention is not limited to this. While the cam signal is generated using the output of a cam switch, the present invention is not limited to this and can be implemented using other methods, such as a rotary encoder or a transistor. The present invention also includes a method for accurately extracting an area, such as acquiring data for the entire area from the beginning and then providing a function for extracting and recording only an arbitrary angle area later.

[0021] The sensor unit 110 is attached to the side of the mold (die) 210 by, for example, screwing. There may be only one sensor unit 110, but multiple sensor units 110 may be attached at different positions on the side of the mold (die) 210. In either case, the sensor unit 110 detects distortion, for example, in the vertical direction, that occurs in the mold of the press machine 200.

[0022] Fig. 2 is a cross-sectional view showing the configuration of the sensor unit 110 according to this embodiment, and Fig. 3 is a top view thereof. The sensor unit 110 detects strain using a MEMS (Micro Electro Mechanical Systems) strain sensor. Note that strain sensors that utilize, for example, changes in resistance or sensors that generate power from strain can also be used, utilizing similar functions.

[0023] 2 and 3, the sensor unit 110 has a thin, elongated flexible substrate 113. The flexible substrate 113 has a MEMS strain sensor 111 disposed on one side thereof and an input / output terminal 112 provided on the other side thereof. The MEMS strain sensor 111 on the flexible substrate 113 is sealed with a sealing material.

[0024] The area of ​​flexible substrate 113 where MEMS strain sensor 111 is arranged is attached, for example, by an adhesive (not shown), to the bottom of recess 115 provided in metal plate 114. Flexible substrate 113 and MEMS strain sensor 111 in the area attached to the bottom of recess 115 are further sealed with sealing material 116.

[0025] MEMS strain sensor 111 on flexible substrate 113 has traditionally been sealed with a sealing material. However, because the measurement order of MEMS strain sensor 111 is so small, it is extremely vulnerable to external disturbances. It is therefore believed that such MEMS strain sensor 111 was not intended for use in on-site environments where oil splashes and strong vibrations occur, such as in press machines. In response to this, the inventors discovered that flexible substrate 113 on which MEMS strain sensor 111 is mounted can be attached to a metal plate or the like, and strain occurring in metal plate 114 or the like can be measured with MEMS strain sensor 111, thereby indirectly measuring strain occurring in a mold or the like. This makes it possible to measure strain occurring in a mold or the like using MEMS strain sensor 111. However, it was discovered that even though MEMS strain sensor 111 is sealed with a sealing material, oil splashes around the sensor or vibrations can cause oil to enter MEMS strain sensor 111, resulting in failure of MEMS strain sensor 111. This is an unprecedented finding that the inventors obtained as a result of attempting to use MEMS strain sensor 111 in such an environment. Therefore, the inventors formed a recess 115 in a metal plate 114 or the like used as a means for indirectly measuring strain occurring in a mold or the like, attached a region of flexible substrate 113 where MEMS strain sensor 111 was disposed to the bottom of recess 115, and sealed these with sealing material 116. It is preferable that recess 115 be filled with at least sealing material 116.

[0026] In the sensor unit 110 according to this embodiment, the area of ​​the flexible substrate 113 where the MEMS strain sensor 111 is arranged is sealed within the recess 115 by the sealing material 116, and in particular the MEMS strain sensor 111 is double-sealed, so that problems caused by oil or dust getting into the MEMS strain sensor 111 can be avoided even in an environment where oil is splashed and the sensor is exposed to severe vibrations, such as in a press machine.

[0027] In the above embodiment, the sensor unit 110 is attached to the side of the mold (die) 210, but instead of or in addition to this, the sensor unit may be configured as part of the shaft 221 as a driven contact of the cam mechanism 230 of the press machine 200. In this case as well, a recess is provided on the side of the metal rod 221, and the area of ​​the flexible substrate 113 where the MEMS strain sensor 111 is arranged is attached to the bottom of the recess with an adhesive, and this area is then sealed with a sealing material.

[0028] FIG. 4 is a block diagram showing the configuration of the flexible substrate 113 of the sensor unit 110 according to this embodiment.

[0029] 4, flexible substrate 113 has MEMS strain sensor 111 and input / output terminal 112, as well as control unit 118 and power storage unit 119. Power storage unit 119 supplies power to each unit, and receives power from the outside via input / output terminal 112 and stores the power.

[0030] The control unit 118 receives and executes commands input from, for example, an external PC 130 via the input / output terminal 112. In response to the commands, the control unit 118 sets an offset value and a magnification factor for the analog strain signal detected by the MEMS strain sensor 111 and output from the input / output terminal 112. This eliminates the need to compensate for the signal output from the sensor unit 110.

[0031] FIG. 5 is a block diagram showing the configuration of the communication control unit 120 according to this embodiment.

[0032] As shown in FIG. 5, the communication control unit 120 uses a cam signal obtained from the cam switch 241 of the cam mechanism 230 as a time axis reference for extracting digital data related to the distortion signal detected by the sensor unit 110, extracts digital data of a predetermined time band based on the cam signal, and transmits the extracted digital data wirelessly.

[0033] The communication control unit 120 has four signal input units 121a to 121d, a cam signal input unit 122, an A / D conversion unit 123, and a microcomputer module .

[0034] The four signal input sections 121a to 121d receive analog distortion signals obtained from the sensor unit 110 as input.

[0035] The cam signal input unit 122 receives the cam signals from the cam switches 241 and 242 .

[0036] The A / D converter 123 converts the analog distortion signals input from the input units 121a to 121d into digital data. The communication control unit 120 also has a digital interface, and is configured to be able to handle not only analog distortion signals from the sensor unit 110, but also digital distortion signals.

[0037] The microcomputer module 124 extracts digital data of a predetermined time band based on the cam signal from each digital data converted by the A / D converter 123, digitalizes the digital data, and transmits the digitalized digital data wirelessly via the antenna 125. Digitalizing the digital data means converting it into numerical values ​​that can be handled by, for example, Microsoft Excel, making it easy to import into a PC at high speed. The microcomputer module 124 may adjust the data acquisition speed in accordance with the rotational speed of the cam mechanism 230 while extracting digital data for a predetermined time band based on the cam signal. In other words, the digital data converted by the A / D conversion unit 123 may be adjusted to an appropriate data amount, and the frequency may be automatically variable. In other words, the optimal data acquisition speed (data acquisition cycle) may be automatically adjusted when recording digital data for the predetermined time band based on the above-mentioned cam signal, and data acquisition may be efficiently processed in accordance with the rotational speed of the cam mechanism 230 of the press machine 200. This makes it possible to adjust the data amount to an optimal amount in accordance with the press speed of the press machine 200.

[0038] The communication control unit 120 has an output section 126 that outputs analog distorted signals input from each of the signal input sections 121a to 121d to the outside, and an analog switch 127 that selects one of the signal input sections 121a to 121d under the control of the microcomputer module 124 and outputs it from the output section 126. The microcomputer module 124 executes the above selection in response to a command input wirelessly from an external PC 130, for example.

[0039] By connecting an analog monitor (not shown) to the output section 126, the waveform of the distortion signal detected by the sensor unit 110 can be displayed on the analog monitor.

[0040] The communication control unit 120 includes a power supply line 128 that supplies power to the sensor unit 110 via each of the signal input units 121a-121d, and a switch 129 that adjusts the voltage of the power supplied to the sensor unit 110 via the power supply line 128 from each of the signal input units 121a-121d, for example, to 5V or 24V. This allows power to be supplied to sensor units 110 with different operating voltages. In this embodiment, the sensor units connected to the signal input units 121a-121d detect strain. However, the communication control unit 120 according to the present invention can also accommodate sensors other than strain, such as pressure and temperature sensors. Even if the operating voltages of the pressure, temperature, and strain sensors themselves are different, power can be supplied to these sensors. While the power supply line 128 is shown as two lines, one for 5V and the other for 24V, the present invention is not limited to this. For example, the power supply line 128 may be selectable from 24V, 5V, 3.3V, etc.

[0041] The PC 130 receives digital data from the communication control unit 120 and uses predetermined software to display it visually, for example, or issues a predetermined notification when an abnormal value is detected, or accumulates digital data and performs estimation processing such as estimating a malfunction based on the accumulated data.

[0042] FIG. 6A shows a schematic diagram of the cam mechanism 230, and FIG. 6B shows digital data relating to the strain signal displayed by the PC 130.

[0043] 6A, when coupling position P of shaft 231 of cam 232 passes cam switch 241, cam switch 241 turns on. The on cam signal of cam switch 241 is input to cam signal input section 122 of communication control unit 120, and communication control unit 120 sets this timing as start point P1 for starting extraction of digital data. When coupling position P of shaft 231 of cam 232 passes cam switch 242, cam switch 242 turns on. The on cam signal of cam switch 242 is input to cam signal input section 122 of communication control unit 120, and communication control unit 120 sets this timing as end point P2 for ending extraction of digital data. Therefore, communication control unit 120 extracts digital data in the time band between start point P1 and end point P2.

[0044] That is, the communication control unit 120 uses the cam signal obtained from the cam switches 241 and 242 of the cam mechanism 230 as a time axis reference for extracting digital data related to the distortion signal detected by the sensor unit 110, extracts digital data of a predetermined time band based on the cam signal, and transmits the extracted digital data wirelessly.

[0045] As shown in (B) of Figure 6, the digital data relating to the distorted signal displayed by PC 130 is displayed between start point P1 and end point P2, and under normal circumstances when there are no problems, the data is displayed so that they almost overlap, for example, as shown by the solid line waveform data 500.

[0046] For example, when "double punching" of a material occurs, a characteristic change such as the time interval of the waveform data 500 shown by the solid line widening by about two times (not shown) appears. When "punch breaking" occurs, a characteristic change such as the absence of a clear peak like that in the waveform data 500 under normal conditions (not shown) appears.

[0047] Therefore, by monitoring the waveform data 500, the PC 130 can discover any defects in the press machine 200.

[0048] According to the monitoring system 100 for the press machine 200 of this embodiment, the communication control unit 120 extracts digital data of a predetermined time band (P1-P2), thereby reducing the amount of digital data transmitted wirelessly. As a result, the density of the digital data transmitted wirelessly (the time interval between data) can be increased, and malfunctions in the press machine can be monitored accurately using wireless data transmission. In this case, a cam signal obtained from the cam mechanism 230, which is synchronized with the punching operation of the press machine 200, is used as the time base for extracting the digital data. This allows accurate comparison of the digital data for each cycle, thereby enabling accurate monitoring of malfunctions in the press machine.

[0049] The present invention is not limited to the above-described embodiments, and modifications and applications are possible within the scope of the technical idea of ​​the present invention, and implementations based on such modifications and applications belong to the technical scope of the present invention.

[0050] For example, in the above embodiment, the timing at which cam switch 242 is turned on is set as the end point P2 at which extraction of digital data ends, but the present invention is not limited to this. For example, a predetermined timer may be started when cam switch 241 is turned on, and the timing at which the timer ends may be set as the end point P2 at which extraction of digital data ends. In the above embodiment, the cam signal is set to a range around bottom dead center by the cam switches 241 and 242. However, the cam signal may be set to the bottom dead center position. The A / D conversion unit 123 always acquires data over 360 degrees. The angle set by the communication control unit 120, for example, a range of -20 to +20 degrees, is calculated by dividing the amount of data for one revolution (determined by the sampling frequency of the A / D conversion unit 123 and the time required for one revolution of the cam signal) by 360. The angle setting can be changed as needed, for example, from the PC 130 via a network. This allows for more efficient testing of the optimal angle on-site than by manually adjusting two cam switches. Although the above embodiment is directed to sensing distortion of the press die, the present invention can also be applied to sensing the rigidity (distortion) of the press body in synchronization with a cam signal. Furthermore, the present invention can also be applied to sensing distortion of other dies and equipment, such as resin dies and forging dies. [Explanation of symbols]

[0051] 100 Press monitoring system 110 Sensor Unit 111 MEMS strain sensor 113 Flexible PCB 114 Metal Plate 115 recess 116 Encapsulating material 118 Control Unit 120 Communication Control Unit 121a to 121d signal input section 122 Cam signal input section 123 A / D conversion section 124 Microcomputer Module 128 Power Supply Line 129 Switch 130 PC as a monitoring device 200 Presses to be monitored 210 Dies 220 Die (Punch) 230 Cam mechanism 231 Shaft 232 Cam 241, 242 Cam switch P1 Starting point for digital data extraction P2 End point at which digital data extraction ends

Claims

1. a sensor unit that detects distortion occurring at a predetermined location of a machine having a mechanism for moving a die using a cam mechanism; a communication control unit that uses a cam signal obtained from the cam mechanism as a time base reference for extracting digital data related to the distortion signal detected by the sensor unit, extracts the digital data of a predetermined time band based on the cam signal, and wirelessly transmits data related to the extracted digital data; a monitoring device that receives data transmitted from the communication control unit and monitors the machine based on the received data; A monitoring system comprising:

2. 2. The monitoring system of claim 1, The sensor unit comprises: a flexible substrate having a MEMS strain sensor disposed on one side thereof; a metal member having a recess, the bottom of which is attached to the area of ​​the flexible substrate where the MEMS strain sensor is disposed; a sealing material that fills the recess and seals the region; have Surveillance system.

3. 3. The monitoring system of claim 2, The sensor unit comprises: The MEMS strain sensor further includes a control unit that sets an offset value and a magnification of the analog strain signal detected by the MEMS strain sensor through an external operation. Surveillance system.

4. The monitoring system according to any one of claims 1 to 3, The communication control unit an input unit that inputs an analog distortion signal obtained from the sensor unit; an A / D conversion unit that converts the analog distortion signal input to the input unit into digital data; The digital data of a predetermined time band based on the cam signal is extracted from the converted digital data, and the extracted digital data is electronically transmitted by radio. Surveillance system.

5. 5. The monitoring system of claim 4, The communication control unit further includes an output section that outputs the analog distorted signal input to the input section to an external device. Surveillance system.

6. 6. The monitoring system according to claim 4 or 5, The communication control unit further includes a power supply unit that supplies power to the sensor unit via the input unit and is capable of varying the voltage value of the supplied power. Surveillance system.

7. a flexible substrate having a MEMS strain sensor disposed on one side thereof; a metal member having a recess, the bottom of which is attached to the area of ​​the flexible substrate where the MEMS strain sensor is disposed; a sealing material that fills the recess and seals the region; A sensor unit comprising:

8. a first input unit that inputs an analog distortion signal detected by a machine having a mechanism that moves a die using a cam mechanism; a second input unit that inputs a cam signal from a cam mechanism of the machine; an A / D conversion unit that converts the analog distortion signal input to the first input unit into digital data, The digital data of a predetermined time band based on the cam signal input by the second input unit is extracted from the digital data converted by the A / D conversion unit, and the extracted digital data is electronically transmitted by radio. Communications control unit.

9. 9. The communication control unit according to claim 8, While extracting digital data of a predetermined time band based on the cam signal, the data acquisition speed is adjusted according to the rotation speed of the cam mechanism. Communications control unit.

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