Press machine and method for detecting abnormality of press machine

Abstract

To provide a press machine or the like capable of detecting abnormality of a mold.SOLUTION: A press machine includes a detection part for detecting a load value in performing press working to a material to be pressed, a storage part for storing the load value detected by the detection part in association with identification information of the mold mounted on the press machine at the time of detecting the load value, a calculation part for calculating the position of a load center acting on the press machine on the basis of the stored load value, calculating the calculated position of the load center as eccentricity from the center of the press machine to acquire an eccentric load, and generating distribution data of the eccentric load of each mold, a determination part for determining abnormality on the basis of the eccentric load acquired on the basis of the load value detected by the detection part, and the distribution data of the eccentric load corresponding to the mold mounted on the press machine at the time of detecting the load value, and a notification part for giving a notification on the abnormality on the basis of a determination result of the determination part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a press machine and a method for detecting an abnormality in a press machine. [Background technology]

[0002] A conventional method is known in which the press load during press working is detected, the amount of eccentricity is calculated based on the detected press load, and if the detected press load exceeds the press load allowable amount based on the calculated amount of eccentricity (the range of an allowable eccentric load diagram defined by the manufacturer for each press), it is determined that a press abnormality has occurred (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-209887 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above conventional method is a function for protecting the press machine. On the other hand, in addition to protecting the press machine, users of the press machine need to manage the state of the die and the precision of the molded product, and if die abnormalities or defective product precision occur, they need to detect them early and take measures. Since die abnormalities and defective product precision are mainly phenomena that occur within the range of the allowable eccentric load diagram, it is difficult to detect die abnormalities and defective product precision with the conventional method.

[0005] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a press machine and a method for detecting an abnormality in a press machine that are capable of detecting an abnormality in a die. [Means for solving the problem]

[0006] (1) A press machine according to the present invention is a press machine characterized by including a detection unit that detects a load value when press processing is performed on a workpiece material; a memory unit that stores the load value detected by the detection unit in correspondence with identification information of a die attached to the press machine at the time the load value is detected; a calculation unit that calculates a position of a center of the load acting on the press machine based on the stored load value, calculates the position of the load center as an amount of eccentricity from a center of the press machine to obtain an eccentric load, and generates distribution data of the eccentric load for each die; a judgment unit that judges an abnormality based on the eccentric load obtained based on the load value detected by the detection unit and the distribution data of the eccentric load corresponding to the die attached to the press machine at the time the load value was detected; and a notification unit that notifies an abnormality based on a judgment result of the judgment unit.

[0007] Furthermore, the present invention provides an abnormality detection method for a press machine, comprising: a detection step of detecting a load value when press processing is performed on a workpiece; a storage step of storing the load value detected in the detection step in association with identification information of a die attached to the press machine at the time the load value was detected; a calculation step of calculating a position of a center of the load acting on the press machine based on the stored load value, calculating the position of the load center as an amount of eccentricity from a center of the press machine to obtain an eccentric load, and generating distribution data of the eccentric load for each die; a determination step of determining an abnormality based on the eccentric load determined based on the load value detected in the detection step and the distribution data of the eccentric load corresponding to the die attached to the press machine at the time the load value was detected; and a notification step of notifying an abnormality based on a determination result of the determination step.

[0008] According to the present invention, the load value detected by the detection unit is stored in association with the identification information of the die attached to the press machine at the time of detection, the position of the load center acting on the press machine is calculated from the stored load value, the calculated position of the load center is calculated as the amount of eccentricity from the center of the press machine to obtain the eccentric load, and distribution data of the eccentric load for each die is generated, and an abnormality is determined based on the eccentric load obtained based on the load value detected by the detection unit and the distribution data of the eccentric load corresponding to the die attached to the press machine at the time of detection of the load value, thereby making it possible to detect an abnormality in the die. Here, the load center means the center of gravity of the load. Also, the center of the press machine means the center position of the slide on a plane perpendicular to the direction in which the slide moves (up and down direction).

[0009] (2) In the press machine according to the present invention, the calculation unit may use a plurality of eccentric load data arbitrarily selected by a user from a data group of eccentric loads corresponding to the same die as distribution data of the eccentric load corresponding to the die.

[0010] In the press machine anomaly detection method according to the present invention, in the calculation step, a plurality of eccentric load data arbitrarily selected by a user from a data group of eccentric loads corresponding to the same die may be used as distribution data of the eccentric load corresponding to the die.

[0011] (3) The press machine according to the present invention may further include a display control unit that causes the display unit to display an image in which a data group of eccentric loads corresponding to the same die is plotted.

[0012] The method for detecting an abnormality in a press machine according to the present invention may further include a display control step of causing a display unit to display an image in which a group of eccentric load data corresponding to the same die is plotted.

[0013] (4) In the press machine of the present invention, the display control unit may cause the display unit to display waveform data of a load value corresponding to data arbitrarily selected by a user from the group of data displayed on the display unit.

[0014] In the abnormality detection method for a press machine of the present invention, in the display control step, waveform data of a load value corresponding to data arbitrarily selected by a user from the group of data displayed on the display unit may be displayed on the display unit. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a press machine according to an embodiment of the present invention. [Diagram 2] FIG. 4 is a diagram showing an example of a load sensor. [Diagram 3] 6 is a flowchart showing a process for generating distribution data of eccentric loads. [Figure 4] FIG. 11 is a diagram showing an example of stored load values. [Diagram 5] FIG. 13 is a diagram showing an example of a display of a data group of eccentric loads corresponding to the same die. [Figure 6] FIG. 13 is a diagram showing an example of a display of a data group of eccentric loads corresponding to the same die. [Figure 7] FIG. 13 is a diagram showing an example of a display of a data group of eccentric loads corresponding to the same die. [Figure 8] FIG. 13 is a diagram showing an example of a display of a data group of eccentric loads corresponding to the same die. [Figure 9] FIG. 13 is a diagram showing an example of a display of a data group of eccentric loads corresponding to the same die. [Figure 10] FIG. 13 is a diagram showing an example of a display of a data group of eccentric loads and waveform data of load values ​​corresponding to the same die. [Figure 11] 11 is a flowchart showing a flow of a process for detecting an abnormality. [Figure 12] FIG. 2 is a diagram for explaining an anomaly detection method according to the present embodiment. [Figure 13] FIG. 13 is a diagram showing an example of a change in distribution of an eccentric load. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0017] FIG. 1 is a diagram showing an example of the configuration of a press machine (servo press) according to this embodiment. The press machine 1 converts the rotation of a servo motor 10 into a vertical reciprocating motion (reciprocating linear motion, lifting motion) of a slide 17 by an eccentric mechanism that converts rotational motion into linear motion, and performs press processing on a workpiece by utilizing the vertical reciprocating motion of the slide 17. The press machine 1 includes a servo motor 10, an encoder 11, a drive shaft 12, a drive gear 13, a main gear 14, a crankshaft 15, a connecting rod 16, a slide 17, a bolster 18, a control device 100, a user interface 110 (operation unit), and a display 120 (display unit). The press machine is not limited to a servo press, and may be, for example, a mechanical press using a flywheel or a linear press using a ball screw. In this case, the encoder may be provided on the shaft end of the crankshaft 15 or the shaft end of the ball screw.

[0018] A drive shaft 12 is connected to the rotating shaft of the servo motor 10, and a drive gear 13 is connected to the drive shaft 12. A main gear 14 is engaged with the drive gear 13, and a crankshaft 15 is connected to the main gear 14, and a connecting rod 16 is connected to the crankshaft 15. The rotating shafts such as the drive shaft 12 and the crankshaft 15 are supported by appropriately provided bearings (not shown). The crankshaft 15 and the connecting rod 16 form an eccentric mechanism. This eccentric mechanism allows a slide 17 connected to the connecting rod 16 to move up and down relative to a bolster 18 on the stationary side. Here, the press machine 1 is a two-point drive press machine in which the crankshaft 15 and the slide 17 are connected by two connecting rods 16 that also function as suspensions. An upper die 20 is attached to the slide 17, and a lower die 21 is attached to the bolster 18.

[0019] The press machine 1 is equipped with a right load sensor 30 and a left load sensor 31 for detecting the load value for each press cycle when pressing the workpiece. As shown in FIG. 2 , the right load sensor 30 is a strain gauge attached to a right column 40 (right side frame) of the press machine 1, and the left load sensor 31 is a strain gauge attached to a left column 41 (left side frame) of the press machine 1. Note that a pressure sensor provided in a hydraulic chamber formed in the slide 17 may be used as the right load sensor 30 and the left load sensor 31. Output data (voltage signals of the strain gauges or pressure sensors) of the right load sensor 30 and the left load sensor 31 are input to the control device 100.

[0020] The control device 100 includes a press control unit 101, a detection unit 102, a storage unit 103, a calculation unit 104, a determination unit 105, a notification unit 106, and a display control unit 107. The control device 100 may be divided into an independent device for controlling the press machine, which is composed of the press control unit 101, the display control unit 107, a user interface 110, and a display 120, and an independent device for detecting a load, which is composed of the detection unit 102, the storage unit 103, the calculation unit 104, the determination unit 105, the notification unit 106, the display control unit 107, the user interface 110, and the display 120. In this case, the output data of the right load sensor 30 and the left load sensor 31 are directly input to the device for detecting the load. In addition, operation information of the press machine, such as crank angle information, is input to the device for detecting the load from the device for controlling the press machine, as necessary.

[0021] The detection unit 102 receives data output from the right load sensor 30 and data output from the left load sensor 31 for each press cycle, converts the received data based on the calibration data stored in the memory unit 103, and detects the load values ​​(right load value and left load value) during press working. The calibration data indicates the relationship between the voltage signal and the load value, and is measured in advance using a load cell or the like and stored in the memory unit 103.

[0022] The storage unit 103 stores the load value detected by the detection unit 102 in the storage unit 104. The identification information (die number) of the dies (upper die 20, lower die 21) attached to the slide 17 and bolster 18 is stored in association with the identification information.

[0023] The calculation unit 104 calculates the position of the center of the load acting on the press machine 1 based on the stored load value, calculates the calculated position of the load center as an amount of eccentricity from the center of the press machine 1 to obtain an eccentric load (a set of a total load value and an amount of eccentricity), and generates distribution data of the eccentric load for each die. The generated distribution data of the eccentric load for each die is stored in the storage unit 103. Here, the calculation unit 104 may treat a plurality of eccentric load data arbitrarily selected by the user from a group of eccentric load data corresponding to the same die as distribution data of the eccentric load corresponding to the die (e.g., normal distribution data).

[0024] The judgment unit 105 judges an abnormality based on the eccentric load calculated by the calculation unit 104 based on the load value detected by the detection unit 102 and the distribution data of the eccentric load corresponding to the dies attached to the slide 17 and bolster 18 of the press machine 1 at the time the load value was detected.

[0025] The notification unit 106 notifies of an abnormality based on the determination result of the determination unit 105. For example, when the determination unit 105 determines that an abnormality has occurred, the notification unit 106 outputs information to that effect to the display 120.

[0026] The display control unit 107 causes the display 120 to display an image in which a data group of eccentric loads corresponding to the same die is plotted on a graph. The display control unit 107 may also cause the display 120 to display waveform data of load values ​​corresponding to data arbitrarily selected by a user from the data group displayed on the display 120.

[0027] The user interface 110 is a known input means (for example, a mouse, a trackball, a keyboard, etc.) that can be operated on the display 120. The user interface 110 may be provided integrally with the display 120. In this case, the input means is displayed on the display 120.

[0028] The display 120 is a liquid crystal display (LCD). Other known display devices (for example, organic EL (Electro Luminescence)) may be used as the display 120. A touch panel type display may be used as the display 120. Known types of touch panels such as resistive film type, capacitive type, surface type capacitive type, and projected type capacitive type may be used as the touch panel. If the display is a touch panel type, input operations can be performed by directly touching the display 120 with a finger or a pen.

[0029] FIG. 3 is a flowchart showing a process for generating eccentric load distribution data.

[0030] The processing of steps S10 to S13 is a processing for storing the load value. The load value is stored when a die is attached to the press machine 1 and a trial operation (die trial) is performed. First, the detection unit 102 receives the data output from the right load sensor 30 and the data output from the left load sensor 31, converts the received data based on the calibration data stored in the storage unit 103, and detects it as a load value (step S10). Next, the control device 100 judges whether one cycle of the press has ended based on the information of the current crank angle (step S11), and if one cycle has not ended (N in step S11), proceeds to step S10 and continues detecting the load value. If one cycle has ended (Y in step S11), the storage unit 103 gives a timestamp to the detected load value for one cycle (waveform data of the right load and the left load), and stores it in association with the die number of the die attached to the slide 17 and the bolster 18 of the press machine 1 at the time of detection (step S12). 4 shows an example of the load value to be stored. As shown in Fig. 4, a load waveform WR for one cycle detected based on data from the right load sensor 30 and a load waveform WL for one cycle detected based on data from the left load sensor 31 are stored as load values ​​in association with the die number. Next, the control device 100 judges whether or not to end the storage of the load values ​​(step S13), and if storage is to be continued (N in step S13), the process proceeds to step S10, and thereafter, the load value is stored for each press cycle.

[0031] The process of steps S14 to S20 is a process for generating distribution data of the eccentric load. First, the control device 100 selects a die number based on an operation by the user on the user interface 110 (step S14). Next, the calculation unit 104 extracts a load value corresponding to the selected die number from the stored load value data (step S15), calculates the position of the load center acting on the press machine 1 from each of the extracted load values, calculates the calculated position of the load center as the amount of eccentricity from the center of the press machine 1 to obtain the eccentric load, and generates a data group of the eccentric load corresponding to the selected die number (step S16). The amount of eccentricity (eccentric position) can be calculated from the balance of the moment based on the left and right load values ​​when the waveform obtained by combining the waveforms of the left and right load values ​​(load waveform WR, load waveform WL) shows a peak value, and the distance between the right load sensor 30 and the left load sensor 31 (distance dc shown in FIG. 2). The amount of eccentricity is a value that becomes positive when the right load is greater than the left load when the waveform obtained by combining the left and right load waveforms reaches a peak value, and becomes negative when the left load is greater than the right load, and the absolute value becomes larger as the difference between the left and right loads increases. The eccentric load is data that combines the peak value (total load value) of the waveform obtained by combining the left and right load waveforms and the amount of eccentricity calculated from the left and right load values. When pressure sensors provided in hydraulic chambers formed in the slide 17 are used as the right load sensor 30 and the left load sensor 31, the amount of eccentricity is calculated based on the left and right load values ​​when the waveform obtained by combining the left and right load value waveforms reaches a peak value and the distance between the two connecting rods 16 (point distance, distance dp shown in FIG. 2).

[0032] Next, the display control unit 107 causes the display 120 to display an image in which the generated eccentric load data group is plotted (step S17). Fig. 5 shows an example of an image in which the eccentric load data group is plotted. The image shown in Fig. 5 is an image in which the eccentric load data group corresponding to the same die (selected die number) is plotted on a graph (scatter plot) with the horizontal axis (X-axis) representing the eccentric position (unit: mm) and the vertical axis (Y-axis) representing the total load value (unit: kN). Each black dot in the figure represents one piece of eccentric load data.

[0033] Next, the user selects a range (normal range) to be treated as a normal distribution from the data group of the eccentric load displayed on the display 120 (step S18). The calculation unit 104 stores the data within the selected range in the storage unit 103 as normal distribution data of the eccentric load corresponding to the die number selected in step S14 (step S19).

[0034] In step S18, since the eccentric load data group may include data that cannot be considered normal, such as eccentric load data based on load values ​​detected while material is passing through the die or eccentric load data based on load values ​​detected during blank firing, the user specifies a range R of the eccentric load data group that is to be normally distributed on the display 120, as shown in Fig. 6. The range R can be specified by using the user interface 110 on the display 120, or by directly touching the display 120 with a finger or a pen. However, when the user actually specifies the range R, it is expected that the user will have difficulty in determining which data from the large number of data groups to specify as the range R. Therefore, a method of providing the user with information for making such a decision will be described below.

[0035] (1) As shown in FIG. 7, a data group of eccentric loads based on the operation information of the press machine 1 may be displayed by legend (symbol). For example, when the operation selection switch is turned on during the press operation, When "continuous (continuous operation)" is selected in the operation selection switch (slow speed, inching, off, safe start, continuous), the data obtained during steady operation may be displayed as outlined dots. On the other hand, when the operation selection switch is set to "slow speed", "inching (inching operation)" or "safe start (safe start)", the data obtained during non-steady operation such as during material passing through the die or blank punching may be displayed as filled dots. By previously associating the operation information of the press machine 1 corresponding to each load value data with the number of shots of the press machine 1 (the value of the production number counter of the press machine 1) and storing it in the memory unit 103, it is possible to associate it with each eccentric load data. Also, a button for displaying or hiding the data group according to the state of the operation selection switch may be provided on the screen.

[0036] (Part 2) As shown in FIG. 8, the data group of the eccentric load may be displayed by a legend based on the information on the accuracy of the molded product. For example, if the product accuracy is judged to be "good", the obtained data group may be displayed by a white dot, and if the product accuracy is judged to be "bad", the obtained data group may be displayed by a black dot. The judgment of the quality of the product accuracy is not limited to "good" and "bad", but may be further subdivided and displayed by a legend according to each. By previously associating the information on the product accuracy corresponding to each load value data with the number of shots of the press machine 1 (the value of the production number counter of the press machine 1) and storing it in the storage unit 103, it is possible to associate it with each eccentric load data. The judgment of the quality of the product accuracy may be automatically input to the storage unit 103 in real time during press operation from an inspection device (not shown), or the result of the sampling inspection may be manually input to the storage unit 103. The input result of the quality judgment is stored in the storage unit 103.

[0037] (3) As shown in Fig. 9, a data group of eccentric loads may be displayed by legend in any elapsed time unit based on the time stamp information. For example, a data group may be displayed by legend for every 30 minutes from the start of operation according to the elapsed time unit. When producing with a new mold, the load value data may change as it transitions from the initial wear after the start of operation (the state in which the fine irregularities in the parts have been removed) to the subsequent steady wear. Even in such a case, if the data is displayed by legend according to the elapsed time unit, it is easy to recognize the change in eccentric load over time and to select the eccentric load data after the transition to steady wear.

[0038] (Fourth) As shown in Fig. 10, the waveform data of the load value corresponding to data arbitrarily selected by the user from the data group of eccentric loads displayed on the display 120 may be displayed on the display 120. In the example shown in Fig. 10, the waveform data of the load value (load waveform WR, load waveform WL) corresponding to the eccentric load EL arbitrarily selected by the user from the data group of eccentric loads and indicated by a white dot in the figure is displayed above the image of the data group of eccentric loads. At this time, the date and time when the data was detected may be displayed together with the waveform data of the load value. In this way, the user can determine which data should be included in the range R of normal distribution based on the waveform of each data of the eccentric load.

[0039] According to the above method, it is possible to provide the user with information to help them specify the range R, and the user can easily determine later which data should be specified as the range R for normal distribution.

[0040] Next, the control device 100 determines whether to continue the process (generate normal distribution data of eccentric load corresponding to another die number) (step S20), and if the process is to be continued (Y in step S20), proceeds to step S14.

[0041] 11 is a flowchart showing the flow of a process for detecting an abnormality. The detection of an abnormality is performed during normal press operation.

[0042] First, the detection unit 102 receives data output from the right load sensor 30 and data output from the left load sensor 31, converts the received data based on the calibration data stored in the storage unit 103, and detects it as a load value (step S30). Next, the control device 100 judges whether one cycle of the press has ended based on the information of the current crank angle (step S31), and if one cycle has not ended (N in step S31), proceeds to step S30 and continues detecting the load value. If one cycle has ended (Y in step S31), the calculation unit 104 calculates the eccentricity from the detected load values ​​for one cycle (waveform data of the right load and the left load) to obtain the eccentric load (a set of the total load value and the eccentricity) (step S32).

[0043] Next, the judgment unit 105 calculates a distance (deviation) from the average value of the eccentric load calculated in step S32 based on the average value and standard deviation σ of the normal distribution data of the eccentric load corresponding to the die number of the die attached to the slide 17 and the bolster 18 of the press machine 1 at the time of detecting the load value in step S30, among the normal distribution data of the eccentric load for each die stored in the memory unit 103 (step S33), and judges whether or not the distance is within a predetermined distance (step S34). If the eccentric load calculated in step S32 is apart from the average value of the normal distribution data by a predetermined distance (e.g., 3σ to 6σ) or more (N in step S34), the notification unit 106 notifies an abnormality (step S35).

[0044] Next, the control device 100 determines whether or not to continue the process of detecting an abnormality (step S36), and if the process is to be continued (Y in step S36), it proceeds to step S30, and thereafter detects an abnormality based on the eccentric load calculated for each press cycle.

[0045] According to this embodiment, the load value detected by the detection unit 102 is stored in advance in association with the die number of the die attached to the slide 17 and the bolster 18 of the press machine 1 at the time of detection of the load value, the eccentric load is calculated from the stored load value to generate normal distribution data of the eccentric load for each die, and an abnormality is determined based on the eccentric load calculated based on the load value detected by the detection unit 102 during press operation and the normal distribution data of the eccentric load corresponding to the die attached to the slide 17 and the bolster 18 of the press machine 1 at the time of detection of the load value, thereby making it possible to detect an abnormality in the die. For example, as shown in FIG. 12, when the eccentric load EL based on the load value detected during press operation is deviated by a predetermined distance or more from the average value of the normal distribution ND of the eccentric load in the normal state due to an abnormality in the die or a defective product precision, an abnormality can be detected even if the eccentric load EL is within the range of the allowable eccentric load diagram AD. On the other hand, in the conventional method, an abnormality cannot be detected as long as the eccentric load EL is within the range of the allowable eccentric load diagram AD. Furthermore, according to this embodiment, by using a range of data arbitrarily specified by the user from the group of eccentric load data corresponding to the same mold as normal distribution data of the eccentric load corresponding to that mold, it is possible to eliminate eccentric load data based on load values ​​detected while material is passing through the mold or during dry casting, and create appropriate normal distribution data of the eccentric load.

[0046] In addition, in this embodiment, it is possible to estimate changes in the die from changes in the distribution of the eccentric load corresponding to the same die. For example, if the normal distribution of the eccentric load immediately after die maintenance is within the range R shown in FIG. 6, and the distribution of the eccentric load corresponding to the same die after tens of thousands of shots becomes the distribution shown in FIG. 13, the distribution of the eccentric load tends to move to the upper left, so it is estimated that wear is progressing in the punch and die on the upstream side of the die, or some kind of abnormality is occurring. In this way, changes or abnormalities in the die can be quickly detected from changes in the distribution of the eccentric load corresponding to the same die, making it possible to perform die maintenance at the optimal timing.

[0047] In the above example, the distribution data of the eccentric load is treated as normal distribution data, and the distance (deviation) from the average value of the normal distribution data to the target is calculated to judge an abnormality. However, the method is not limited to this. For example, the MT (Maharanobis-Taguchi) method may be used to determine an abnormality by calculating the Mahalanobis distance from the center of the unit space to the target, using the distribution data of the eccentric load (data of a plurality of eccentric loads selected by the user from a data group of eccentric loads corresponding to the same die) as the unit space.

[0048] Incidentally, Patent Document 1 discloses a calculation method for creating an allowable load diagram (corresponding to AD in FIG. 12) for a two-point drive press machine, which has long been well known among those skilled in the art. The allowable eccentric load diagram created by this calculation method is limited only by the point capacity, and does not take into account the influence of the inclination of the slide. For this reason, even if the press machine is used with a load within the allowable value of the eccentric load, there is a concern that malfunctions may occur, such as deterioration of product accuracy due to the inclination of the slide, seizure of the slide guide, damage to the die, and even damage to the frame and points of the press machine. In order to avoid such malfunctions, each press manufacturer creates a composite allowable load diagram based on the limit of the point capacity, taking into account the safety factor and the limit of the inclination amount of the slide, and provides it to users.

[0049] Although the embodiments of the present invention have been described in detail as above, it will be easily understood by those skilled in the art that many modifications are possible without substantially departing from the novel points and effects of the present invention. [Explanation of symbols]

[0050] 1...press machine, 10...servo motor, 11...encoder, 12...drive shaft, 13...drive gear, 14...main gear, 15...crankshaft, 16...connecting rod, 17...slide, 18...bolster, 20...upper die, 21...lower die, 30...right load sensor, 31...left load sensor, 40...right column (right side frame), 41...left column (left side frame), 100...control device, 101...press control unit, 102...detection unit, 103...storage unit, 104...calculation unit, 105...determination unit, 106...notification unit, 107...display control unit, 110...user interface, 120...display

Claims

1. a detection unit for detecting a load value when performing press working on a workpiece; a storage unit that stores the load value detected by the detection unit in association with identification information of a die attached to the press machine at the time the load value is detected; a calculation unit that calculates a position of a center of a load acting on the press machine based on the stored load value, calculates the position of the load center as an amount of eccentricity from a center of the press machine to obtain an eccentric load, and generates distribution data of the eccentric load for each die; a determination unit that determines an abnormality based on an eccentric load calculated based on the load value detected by the detection unit and distribution data of the eccentric load corresponding to a die attached to the press machine at the time of detection of the load value; and a notification unit that notifies an abnormality based on a determination result of the determination unit.

2. In claim 1, The calculation unit is A press machine, characterized in that a plurality of eccentric load data arbitrarily selected by a user from a data group of eccentric loads corresponding to the same die is used as eccentric load distribution data corresponding to the die.

3. In claim 2, A press machine further comprising a display control unit that causes a display unit to display an image in which a data group of eccentric loads corresponding to the same die is plotted.

4. In claim 3, The display control unit is a display unit displaying waveform data of a load value corresponding to data arbitrarily selected by a user from the group of data displayed on the display unit.

5. A detection step of detecting a load value when performing press working on a workpiece; a storage step of storing the load value detected in the detection step in association with identification information of a die attached to the press machine at the time the load value was detected; a calculation step of calculating a position of a center of a load acting on the press machine based on the stored load value, calculating the position of the load center as an amount of eccentricity from a center of the press machine to obtain an eccentric load, and generating distribution data of the eccentric load for each die; a determination step of determining an abnormality based on the eccentric load calculated based on the load value detected in the detection step and distribution data of the eccentric load corresponding to the die attached to the press machine at the time of detection of the load value; a notifying step of notifying an abnormality based on a result of the determination step.

Images