Machining defect determination device

Abstract

To disclose an example of a machining defect determination device and the like.SOLUTION: A machining defect determination device determines whether a machining defect has occurred in an object W to be machined by using an average value of detected waves for each movement amount after the start of machining from a time when a punch contacts the object to be machined to a time when the punch is closest to a die. It is thus possible to accurately determine whether or not the machining defect has occurred. The movement amount after the start of machining is a value obtained by multiplying a unit displacement amount by a natural number. The unit displacement amount refers to a movement amount smaller than a measurement target movement amount. The measurement target movement amount refers to a movement amount of the punch from a time when the punch descents and comes into contact with the object W to be machined to a time when the punch is closest to the die.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a processing defect determination device that determines whether or not a processing defect has occurred in a press processed object. [Background technology]

[0002] For example, in the processing defect judgment device described in Patent Document 1, elastic waves generated during molding of the workpiece are detected by a first AE sensor and a second AE sensor, and the ratio of the integral value of the elastic waves detected by the first AE sensor to the integral value of the elastic waves detected by the second AE sensor is compared with a ratio measured in advance for a good product to judge whether the press molding is good or bad. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-285949 A Summary of the Invention [Problem to be solved by the invention]

[0004] In mass production machines for press products, the speed of each shot varies, so the amount of data that needs to be detected by the AE sensor is constantly changing. For this reason, it is difficult to accurately determine whether or not a processing defect has occurred by simply comparing a value based on the detection value with a value for a non-defective product that has been measured in advance, as in the invention described in Patent Document 1. The present disclosure discloses an example of a processing defect determination device or the like that takes this point into consideration. [Means for solving the problem]

[0005] A processing defect judgment device that is applied to a press machine having a punch (2) and a die (3) for plastically deforming a metal workpiece and judges whether a processing defect has occurred in the workpiece desirably has at least one of the following components, for example:

[0006] That is, the components are an elastic wave detector (4) that detects elastic waves emitted when the workpiece is deformed or broken, and a processing defect judgment unit (5) that uses the detection signal of the elastic wave detector (4) to judge whether a processing defect has occurred in the workpiece.

[0007] It is desirable that the processing defect judgment unit (5) has a function of calculating measurement data, which is the average, mode, median, maximum or minimum value of multiple detection waves for each movement amount after the start of processing, from the time when the punch (2) comes into contact with the workpiece to the time when the punch (2) is closest to the die (3), and a function of judging whether or not a processing defect has occurred in the workpiece by comparing the measurement data with measurement data for a non-defective product that has been stored in advance.

[0008] The detection value of the elastic wave detector (4) is defined as the detection wave, the movement amount of the punch (2) from when the punch (2) comes into contact with the workpiece to when the punch (2) is closest to the die (3) is defined as the measurement target movement amount, a movement amount smaller than the measurement target movement amount is defined as a unit movement amount, and a value obtained by multiplying the unit movement amount by a natural number is defined as the movement amount after processing begins.

[0009] As a result, the processing defect judgment device can judge whether a processing defect has occurred in the workpiece by utilizing the average value of the detection wave for each amount of movement after processing begins, from the time when the punch (2) comes into contact with the workpiece to the time when the punch (2) is closest to the die (3), so it may be possible to accurately judge whether a processing defect has occurred.

[0010] Incidentally, the symbols in the above parentheses are examples showing the corresponding relationship with the specific configurations etc. described in the embodiments described below, and the present disclosure is not limited to the specific configurations etc. shown by the symbols in the above parentheses. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a press device according to a first embodiment. [Diagram 2]13 is a flowchart showing "control for determining machining defects." DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The following "embodiment of the invention" shows an example of an embodiment that falls within the technical scope of the present disclosure. In other words, the invention-specific matters described in the claims are not limited to the specific configurations and structures shown in the following embodiment.

[0013] In addition, arrows and diagonal lines indicating directions in each figure are provided to facilitate understanding of the relationship between the figures and the shapes of each member or part. Therefore, the invention shown in this disclosure is not limited to the directions indicated in each figure. Diagonal lines do not necessarily indicate cross-sectional views.

[0014] At least one of the members or parts described with a reference symbol is provided, unless otherwise specified by "one". In other words, unless otherwise specified by "one", two or more of the members may be provided. The processing defect determination device disclosed in the present disclosure includes at least one of the components such as the members or parts described with a reference symbol and the structural parts shown in the drawings.

[0015] (First embodiment) <1. Overview of the press equipment> In this embodiment, a processing defect determination device and an example of software for a press apparatus according to the present disclosure are applied to a press apparatus.

[0016] As shown in FIG. 1, a press machine 1 according to this embodiment at least includes a punch 2, a die 3, an AE (acoustic emission) sensor 4, an AE analyzer 5, a display 6, and the like.

[0017] The punch 2 and the die 3 constitute a press machine that plastically deforms a metal workpiece W. The punch 2 presses the workpiece W while approaching the die 3, thereby plastically deforming the workpiece W in cooperation with the die 3.

[0018] The AE sensor 4 is an example of an elastic wave detector that detects elastic waves (acoustic emission waves: AE waves) emitted when the workpiece W is deformed or broken. The AE analyzer 5 constitutes a processing defect determination unit that uses the detection signal of the AE sensor 4 to determine whether a processing defect has occurred in the workpiece W.

[0019] The AE analysis device 5 according to this embodiment is configured with a computer having a CPU, a ROM, a RAM, etc. The function of determining a machining defect is realized by executing software pre-stored in a non-volatile storage device such as a ROM by the CPU, that is, the AE analysis device 5.

[0020] The detection signal output from the AE sensor 4 is input to the AE analyzer 5 via a predetermined interface (not shown). The display 6 displays the result of the determination by the AE analyzer 5 in a form that can be recognized by the user.

[0021] <2. Determining machining defects using AE analysis equipment> <2.1 Definition of terms> <detection wave> The detection wave refers to the detection value of the AE sensor 4 .

[0022] <Amount of movement to be measured> The measurement target movement amount refers to the movement amount of the punch 2 from when the punch 2 descends and contacts the workpiece W to when the punch 2 is closest to the die 3.

[0023] In the following description, the amount of movement of the punch 2 is represented by the rotation angle of a member that rotates in conjunction with the displacement of the punch 2. Specifically, the point when the punch 2 is farthest from the die 3 is defined as 0°, and the point when the punch 2 is closest to the die 3 is defined as 180°.

[0024] A detection value of a sensor (not shown) that detects the amount of movement of the punch 2 (the above-mentioned rotation angle in this embodiment) is input to the AE analysis device 5. The AE analysis device 5 uses the rotation angle as it is as the "amount of movement of the punch 2."

[0025] The movement amount corresponding to "when punch 2 contacts the workpiece", i.e., the rotation angle, is a value confirmed in advance by tests or numerical simulations, etc. Therefore, for example, when punch 2 descends and contacts workpiece W at an angle of 145°, the measured movement amount is 35° (=180°-145°).

[0026] <Unit travel amount> The unit movement amount is a movement amount smaller than the measurement target movement amount. In this embodiment, 1° is used as the unit movement amount.

[0027] <Amount of movement after starting machining> The movement amount after the start of processing is the value obtained by multiplying the unit movement amount by a natural number. For example, if the unit movement amount is 1°, the movement amount after the start of processing will be 1°, 2°, 3°, ... 35°.

[0028] <2.2 Overview of processing defect judgment> When determining whether or not there is a processing defect, the AE analysis device 5 first performs a data acquisition function, and then performs a comparison function to determine whether or not there is a processing defect.

[0029] The press machine continuously presses the workpiece W by repeatedly moving the punch 2 up and down. When the amount of movement is from 0° to 360° in one cycle (hereinafter referred to as one shot), the AE analyzer 5 executes the data acquisition function and the comparison function for each shot.

[0030] <Data acquisition function> The data acquisition function is a function that calculates measurement data for each movement amount after the start of processing, from the time when the punch 2 comes into contact with the workpiece (e.g., 145°) to the time when the punch 2 is closest to the die 3 (e.g., 180°).

[0031] Specifically, the AE analyzer 5 can acquire the detection wave at a predetermined period. The movement amount of the punch 2 per period is smaller than the unit movement amount. Therefore, the AE analyzer 5 detects the detection wave multiple times (e.g., n times) while the punch 2 moves by the unit movement amount (1° in this embodiment).

[0032] Therefore, the AE analysis device 5 takes the average value of the detection waves acquired when the movement amount after the start of processing is 1°, that is, while the punch 2 moves from 145° to 146°, as the measurement data when the movement amount after the start of processing is 1°.

[0033] Specifically, if the detection values ​​obtained while punch 2 moves from 145° to 146° are a1, a2, a3··an, then (a1+a2+a3+··+an) / n is defined as the measurement data when the movement amount after the start of processing is 1°.

[0034] Similarly, the AE analysis device 5 takes the average value of the detection waves acquired when the movement amount after the start of processing is 2°, that is, while the punch 2 moves from 146° to 147°, as the measurement data when the movement amount after the start of processing is 2°.

[0035] Specifically, if the detection values ​​obtained while punch 2 moves from 146° to 147° are b1, b2, b3··bn, then (b1+b2+b3+··+bn) / n is the measurement data when the movement amount after the start of processing is 2°.

[0036] Similarly, the AE analysis device 5 takes the average value of the detection waves acquired when the movement amount after the start of processing is 3°, that is, while the punch 2 moves from 147° to 148°, as the measurement data when the movement amount after the start of processing is 3°.

[0037] Specifically, if the detection values ​​obtained while punch 2 moves from 147° to 148° are c1, c2, c3··cn, then (c1+c2+c3+··+cn) / n is defined as the measurement data when the movement amount after the start of processing is 3°.

[0038] That is, the average value of the detection waves is the average value of the detection values ​​detected by the AE sensor 4 while the punch 2 moves by a unit movement amount. Then, the AE analyzer 5 calculates the measurement data for each movement amount after the start of processing when the movement amount after the start of processing is 1° to 35°, and then stores the measurement data in a storage device (not shown).

[0039] <Compare function> The comparison function is a function that determines whether or not a processing defect has occurred in the workpiece W by comparing the "measurement data acquired by the data acquisition function" with the "measurement data for a non-defective product that has been stored in advance (hereinafter referred to as the non-defective product data)."

[0040] The non-defective data is data measured in advance for each amount of movement after the start of processing. In other words, the non-defective data is a collection of measurement data of non-defective products associated with each amount of movement after the start of processing. Note that the non-defective data according to this embodiment is a threshold value that is determined in advance for each amount of movement after the start of processing.

[0041] <2.3 Details of judgment of processing defects> 2 is a flowchart showing the "determination control of machining defects" executed for each shot by the AE analysis device 5. Software for executing the determination control is stored in advance in a non-volatile storage unit such as a ROM.

[0042] When the judgment control is started, the AE analyzer 5 judges whether or not an activation signal has been input to the AE analyzer 5 (S1). The activation signal is a signal that is generated when the punch 2 comes into contact with the workpiece.

[0043] When an activation signal is input to the AE analysis device 5 (S1: YES), the AE analysis device 5 acquires information on the detection wave (S3) and calculates the average value of the detection values ​​detected while the punch 2 moves by a unit movement amount, i.e., the measurement data (S5).

[0044] At this time, the AE analyzer 5 associates the measurement data calculated for each amount of movement after the start of processing with the amount of movement after the start of processing, and then stores the measurement data in a storage device (not shown).

[0045] It should be noted that "associating the measurement data with the amount of movement after the start of processing" means, for example, when the amount of movement after the start of processing is 1°, that is, associating the measurement data for the period during which punch 2 moves from 145° to 146° with the amount of movement after the start of processing of "1°".

[0046] Next, the AE analyzer 5 compares each of the "measurement data acquired (in S5)" with the "threshold value for the corresponding movement amount after the start of machining" for each movement amount after the start of machining (S7). Then, when measurement data that is equal to or exceeds the threshold value is found among the multiple measurement data (S9: NG), the AE analyzer 5 displays a warning on the display 6 that "a machining defect has occurred" (S11), and then ends this control.

[0047] When each of the multiple measurement data is less than the corresponding threshold, that is, when no measurement data that is greater than or equal to the threshold is found within the measurement target movement amount (S9: OK), the AE analysis device 5 terminates this control without displaying a warning.

[0048] 3. Features of the Press Device According to the Present Embodiment In the press device 1 according to this embodiment, whether or not a processing defect has occurred in the workpiece W is determined by using the average value of the detection wave for each movement amount after the start of processing from when the punch 2 comes into contact with the workpiece W to when the punch 2 is closest to the die 3. This makes it possible to accurately determine whether or not a processing defect has occurred.

[0049] That is, generally, in a press machine, the speed of each shot varies, whereas the AE sensor 4 detects AE waves at a predetermined cycle, so the total amount of data detected by the AE sensor 4 is constantly changing.

[0050] For this reason, the number of defective product data is constantly changing, and if the total amount of data is used to determine the quality of a pressed product, it is difficult to accurately determine whether a processing defect has occurred. In other words, if the total amount of data used to determine the threshold for a non-defective product differs from the total amount of data during processing to be determined, it is difficult to obtain an accurate judgment result.

[0051] In contrast, in this embodiment, the average value of the detection waves for each movement amount after the start of processing, that is, the average value of the detection values ​​detected by the AE sensor 4 while the punch 2 moves by a unit movement amount, is used to determine whether a processing defect has occurred in the workpiece W.

[0052] Therefore, even if the total amount of data used to determine the threshold value for non-defective products differs from the total amount of data at the time of processing to be judged, the influence of the difference can be small. Therefore, in this embodiment, it is possible to obtain an accurate judgment result.

[0053] (Other embodiments) In the above embodiment, the AE sensor 4 is used as the elastic wave detector. However, the present disclosure is not limited thereto. That is, the elastic wave detector may be, for example, a piezoelectric element sensor, a strain sensor, a capacitance sensor, an eddy current sensor, or a laser interferometer.

[0054] In the above embodiment, since the unit movement amount was 1°, the movement amount after the start of processing was 1°, 2°, 3°, 35°. However, the present disclosure is not limited to this. That is, in the present disclosure, for example, when the unit movement amount is 5°, the movement amount after the start of processing is 5°, 10°, 15°, 35°. Also, for example, when the unit movement amount is 0.5°, the movement amount after the start of processing is 0.5°, 1°, 1.5°, 35°.

[0055] In the above embodiment, the measurement data is the average value of the detection values ​​detected by the AE sensor 4 while the punch 2 moves by a unit movement amount. However, the present disclosure is not limited to this. That is, in the present disclosure, for example, (a) the measurement data may be the mode, median, maximum, or minimum value of the detection values ​​detected by the AE sensor 4 while the punch 2 moves by a unit movement amount.

[0056] The AE sensor 4 according to the embodiment described above obtains a plurality of detection values ​​while the punch 2 moves by a unit movement amount. However, the present disclosure is not limited to this. That is, the present disclosure may be configured to continuously detect elastic waves while the punch 2 moves by a unit movement amount, for example.

[0057] In addition, in this configuration, for example, (b) the measurement data may be a value obtained by dividing the integrated value of the detection values ​​detected while the punch 2 moves by a unit movement amount by the time required to move by that unit movement amount.

[0058] In other words, the data acquisition function of the disclosure may be "a function of calculating measurement data using the detection value detected by the AE sensor 4 while the punch 2 moves a unit movement amount for each movement amount after the start of processing."

[0059] In the above case, the pre-stored measurement data for a non-defective product, i.e., the threshold value in FIG. 2, must be measurement data for a non-defective product measured by the same method as in the above case (a) or (b).

[0060] In the above-described embodiment, the movement amount of the punch 2 from when the punch 2 descends and contacts the workpiece W to when the punch 2 is closest to the die 3 is used as the measurement target movement amount. However, the present disclosure is not limited to this.

[0061] That is, in this disclosure, for example, "the time when the punch 2 descends and contacts the workpiece W" may be replaced with "a time determined in advance by testing or the like." The "time determined in advance by testing or the like" is, for example, a state in which the amount of plastic deformation of the workpiece W becomes "an amount of deformation at which cracks or the like are likely to occur."

[0062] Furthermore, the present disclosure is not limited to the above-mentioned embodiments as long as it is consistent with the gist of the disclosure described in the above-mentioned embodiments. Therefore, the present disclosure may be a configuration in which at least two of the above-mentioned embodiments are combined, or a configuration in which any of the components illustrated or the components described with reference numerals in the above-mentioned embodiments are eliminated. [Explanation of symbols]

[0063] 1... Press device 2. Punch 3. Dice 4...AE sensor 5…AE analysis device 6… Display

Claims

1. A processing defect judgment device that is applied to a press device equipped with a punch and a die for plastically deforming a metal workpiece and judges whether a processing defect has occurred in the workpiece, comprising: an elastic wave detector that detects elastic waves generated when the object to be processed is deformed or broken; a processing defect determination unit that determines whether a processing defect has occurred in the object by utilizing a detection signal from the elastic wave detector, The detection value of the elastic wave detector is defined as a detection wave. A movement amount of the punch from when the punch contacts the workpiece to when the punch is closest to the die is defined as a measurement target movement amount, A movement amount smaller than the measurement object movement amount is set as a unit movement amount, When the value obtained by multiplying the unit movement amount by a natural number is set as the movement amount after the start of processing, The processing defect determination unit is A function of calculating measurement data that is an average value, a mode value, a median value, a maximum value, or a minimum value of a plurality of the detection waves for each movement amount after the start of the processing from the time when the punch contacts the workpiece to the time when the punch is closest to the die; and A function of judging whether or not a processing defect has occurred in the workpiece by comparing the measurement data with pre-stored measurement data of a non-defective product. A processing defect judgment device that can demonstrate the above.

2. A punch and a die for plastically deforming a metal workpiece; The present invention is applied to a press machine equipped with an elastic wave detector that detects elastic waves emitted when a workpiece is deformed or broken, Software incorporated in a computer that functions as a processing defect determination unit that determines whether a processing defect has occurred in the object by utilizing a detection signal from the elastic wave detector, The detection value of the elastic wave detector is defined as a detection wave. A movement amount of the punch from when the punch contacts the workpiece to when the punch is closest to the die is defined as a measurement target movement amount, A movement amount smaller than the measurement object movement amount is set as a unit movement amount, When the value obtained by multiplying the unit movement amount by a natural number is set as the movement amount after the start of processing, The computer, A function of calculating measurement data that is an average value, a mode value, a median value, a maximum value, or a minimum value of a plurality of the detection waves for each movement amount after the start of the processing from the time when the punch contacts the workpiece to the time when the punch is closest to the die; and A function of judging whether or not a processing defect has occurred in the workpiece by comparing the measurement data with pre-stored measurement data of a non-defective product. Press equipment software to achieve this.

3. A press apparatus having a punch and a die for plastically deforming a metal workpiece, an elastic wave detector that detects elastic waves generated when the object to be processed is deformed or broken; a processing defect determination unit that determines whether a processing defect has occurred in the object by utilizing a detection signal from the elastic wave detector, The detection value of the elastic wave detector is defined as a detection wave. A movement amount of the punch from when the punch contacts the workpiece to when the punch is closest to the die is defined as a measurement target movement amount, A movement amount smaller than the measurement object movement amount is set as a unit movement amount, When the value obtained by multiplying the unit movement amount by a natural number is set as the movement amount after the start of processing, The processing defect determination unit is A function of calculating measurement data that is an average value, a mode value, a median value, a maximum value, or a minimum value of a plurality of the detection waves for each movement amount after the start of the processing from the time when the punch contacts the workpiece to the time when the punch is closest to the die; and A function of judging whether or not a processing defect has occurred in the workpiece by comparing the measurement data with pre-stored measurement data of a non-defective product. A press device capable of exerting the above-mentioned functions.

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