Injection molding machine, monitoring device for injection molding machine, monitoring method, and program

Abstract

To provide an injection molding machine, a monitoring device and a monitoring method for an injection molding machine, and a program capable of performing an accurate abnormality detection.SOLUTION: A monitoring device of an injection molding machine for monitoring an abnormality related to an operation of a servomotor installed in the injection molding machine comprises: a sampling interval calculation unit for calculating a sampling interval for acquiring sampling data; a normalized data generation unit for generating normalized data; and an alarm control unit for outputting an alarm signal to an alarm device when an integrated value of the normalized data is determined to exceed a threshold value. The sampling interval calculation unit calculates a time which is a value obtained by multiplying a calculation period by a predetermined integer and which is equal to or more than an operation time of the servomotor as the sampling interval.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an injection molding machine, a monitoring device for an injection molding machine, a monitoring method, and a program. [Background technology]

[0002] In an automatically operated injection molding machine, monitoring for abnormalities is more important than in a manually operated injection molding machine. Conventionally, in order to monitor for abnormalities in an injection molding machine, there are injection molding machine control devices that detect the current value of a motor provided in the injection molding machine and determine whether an abnormality has occurred in the injection molding machine based on the detected current value (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-280015 [Patent Document 2] International Publication No. 2005 / 061206 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional technology determines abnormalities such as the intrusion of foreign matter based on the results of detecting the current value during the process from mold opening to mold closing. The timing of detecting the current value is determined by a fixed sampling time obtained by dividing the time from the start to the end of the mold closing operation into multiple periods. Therefore, depending on the relationship with the calculation period of the control device, it may not be possible to obtain sampling data for the entire process, making it difficult to adequately determine abnormalities.

[0005] The present invention has been made to solve the above problems, and its purpose is to provide an injection molding machine, a monitoring device for an injection molding machine, a monitoring method, and a program that can perform highly accurate abnormality detection. [Means for solving the problem]

[0006] The injection molding machine monitoring device of the present invention, which solves the above-mentioned problems, is an injection molding machine monitoring device that monitors abnormalities in the operation of a servo motor provided in an injection molding machine, and includes a sampling data acquisition unit that acquires sampling data obtained by sampling at least one of the torque of the servo motor or the speed of the servo motor, a sampling interval calculation unit that calculates the sampling interval at which the sampling data is acquired, a standardized data generation unit that calculates the sampling data obtained at the calculated sampling interval at a predetermined calculation period to generate standardized data, and an alarm control unit that outputs an alarm signal to an alarm device when it is determined that the integrated value of the standardized data exceeds a threshold, and the sampling interval calculation unit calculates the sampling interval as a value obtained by multiplying the calculation period by a predetermined integer, and is a time that is equal to or longer than the operating time of the servo motor.

[0007] In the present invention, the sampling interval is a value obtained by multiplying the calculation period by a predetermined integer, and is equal to or greater than the operating time of one servo motor process. This allows sampling data to be acquired from the entire range of one process, thereby enabling highly accurate abnormality detection.

[0008] In the present invention, the sampling interval calculation unit may calculate the sampling interval as the minimum value among values ​​obtained by multiplying the calculation period by a predetermined integer, the minimum value being equal to or greater than the operating time of the servo motor. In this case, more sampling data can be obtained, enabling more accurate abnormality determination.

[0009] In the present invention, the sampling data acquisition unit may further include a threshold calculation unit that acquires the sampling data while the injection molding machine is performing injection molding and calculates the threshold based on the acquired sampling data. In this case, the threshold for issuing an alarm is calculated based on past sampling data, so that an alarm signal can be prevented from being issued too frequently.

[0010] In the present invention, the threshold calculation unit may calculate the threshold value according to a sensitivity based on a maximum value of the standardized data generated in the past. In this case, the threshold value can be easily calculated.

[0011] The present invention may further include a reception unit that receives the sensitivity designation. In this case, the monitoring level at which an alarm is issued can be adjusted by designation by an operator or the like who operates the injection molding machine.

[0012] In the present invention, the alarm control unit may determine whether the threshold is exceeded at any one of the monitoring levels, including a first monitoring level or a second monitoring level transitioned from the first monitoring level, and transition the monitoring level from the first monitoring level to the second monitoring level when the integrated value of the standardized data generated while injection molding is performed a specific number of times at the first monitoring level is equal to or less than a preset reference value, and increase the specific number of times when the integrated value of the standardized data generated while injection molding is performed a specific number of times at the first monitoring level exceeds the reference value. In this case, the specific number of times injection molding is performed to generate the standardized data is specified depending on the generation status of the standardized data, thereby enabling abnormality determination to be performed in a more stable state.

[0013] In the present invention, the standardized data generating unit may generate the standardized data by dividing the deviation between the value of the acquired sampling data and the average value of the previously acquired sampling data by the average deviation of the sampling data. In this case, standardized data suitable for anomaly detection can be generated.

[0014] In the present invention, the servo motor may rotate a screw that plasticizes the molding material in the injection molding machine. In this case, it is possible to determine an abnormality in the screw that plasticizes the molding material.

[0015] In the present invention, the servo motor may be one that drives an ejector in the injection molding machine, in which case an abnormality in the ejector device that drives the ejector can be determined.

[0016] In the present invention, the alarm control unit may stop the operation of the servo motor as the alarm control, thereby suppressing a breakdown due to an abnormality in the injection molding machine.

[0017] In the present invention, the alarm control unit may output an alarm to an output interface, in which case an operator or the like can be notified that an abnormality has occurred in the injection molding machine.

[0018] The injection molding machine of the present invention, which solves the above problems, is an injection molding machine comprising a screw that plasticizes a molten molding material, a mold into which the plasticized molding material is injected, an ejector pin that ejects a molded product formed in the mold, a metering servomotor that rotates the screw, an ejector servomotor that causes the ejector pin to perform an ejection operation, and an injection molding machine monitoring device described in any one of claims 1 to 11.

[0019] The method for monitoring an injection molding machine according to the present invention, which solves the above-mentioned problems, is a method for monitoring an injection molding machine that monitors abnormalities in the operation of a servo motor provided in the injection molding machine, characterized in that a computer acquires sampling data obtained by sampling at least one of the torque of the servo motor or the speed of the servo motor, calculates a sampling interval for acquiring the sampling data, calculates the sampling data acquired at the calculated sampling interval at a predetermined calculation period to generate standardized data, and outputs an alarm signal to an alarm device when it is determined that the integrated value of the standardized data exceeds a threshold value, and the computer calculates as the sampling interval a value obtained by multiplying the calculation period by a predetermined integer, which is equal to or longer than the operating time of the servo motor.

[0020] The program of the present invention, which solves the above problem, is a program that causes a computer of a monitoring device for an injection molding machine to execute control and monitor abnormalities in the operation of a servo motor provided in an injection molding machine, and causes the computer to acquire sampling data obtained by sampling at least one of the torque of the servo motor or the speed of the servo motor, calculate a sampling interval for acquiring the sampling data, calculate the sampling data acquired at the calculated sampling interval at a predetermined calculation period to generate standardized data, and, when it is determined that the integrated value of the standardized data exceeds a threshold, cause an alarm device to output an alarm signal, and cause the computer to calculate as the sampling interval a value obtained by multiplying the calculation period by a predetermined integer and which is equal to or greater than the operating time of the servo motor. [Effects of the Invention]

[0021] According to the present invention, highly accurate abnormality determination can be performed. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram showing an injection molding machine 1 according to an embodiment. [Figure 2] 1 is a block diagram of a monitoring device 100 according to an embodiment. [Figure 3] 10 is a flowchart showing an example of a procedure for monitoring an abnormality in the monitoring device 100. [Figure 4] 4 is a flowchart illustrating an example of a procedure for monitoring an abnormality in the monitoring device 100, following FIG. [Figure 5] 10 is a flowchart showing an example of a procedure for determining a sampling interval in the monitoring device 100. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It is a diagram showing an injection molding machine 1 according to the embodiment. As shown in FIG. 1, the injection molding machine 1 includes, for example, an injection unit 10, a mold clamping unit 20, and a control device 30. The mold clamping unit 20 includes, for example, an opening / closing mechanism 40, an ejector unit 50, and a mold 60. The mold 60 is attached to the ejector unit 50. The mold 60 includes a movable mold 61 and a fixed mold 62. The control device 30 includes, for example, an input / output device 70, an alarm device 80, a molding control device 90, and a monitoring device 100.

[0024] The injection device 10 includes a cylinder 11. A hopper 12 is connected to the cylinder 11, and a molding material in a pre-melted state, such as a plastic resin (hereinafter referred to as "resin") stored in the hopper 12, is injected into the cylinder 11. A screw 13 is disposed inside the cylinder 11. A metering servomotor 14 is connected to the screw 13. The metering servomotor 14 rotates the screw 13 based on a control signal output from the control device 30. As the screw 13 rotates, the molten resin injected into the cylinder 11 is kneaded and plasticized.

[0025] The metering servomotor 14 is provided with a metering sensor 15. The metering sensor 15 includes a metering speed sensor 15A and a metering torque sensor 15B. The metering speed sensor 15A detects the speed of the metering servomotor 14. The metering torque sensor 15B detects the current value of the current supplied to the metering servomotor 14 and calculates the torque applied to the metering servomotor 14 based on the detected current value. The metering sensor 15 outputs the detected speed and torque of the metering servomotor 14 (hereinafter referred to as "metering motor detection values") to a monitoring device 100 included in the control device 30.

[0026] An injection mechanism 16 is provided on the side of the cylinder 11 opposite to the side where the mold clamping device 20 is disposed. An injection servo motor 17 is connected to the injection mechanism 16. The injection servo motor 17 causes the injection mechanism 16 to inject the resin in the cylinder 11 based on a control signal output from the control device 30. The injection mechanism 16 applies pressure (pressurizes) to the resin in the cylinder 11, thereby injecting the resin.

[0027] A nozzle touch mechanism 18 is provided below the cylinder 11. A nozzle touch geared motor 19 is connected to the nozzle touch mechanism 18. The nozzle touch geared motor 19 brings the cylinder 11 into close contact with an injection hole provided in the mold 60 based on a control signal output from the control device 30. After the nozzle touch mechanism 18 has brought the cylinder 11 into close contact with the injection hole of the mold 60, the injection mechanism 16 applies pressure to the resin in the cylinder 11, thereby injecting the resin into the mold.

[0028] The opening and closing mechanism 40 in the mold clamping device 20 includes, for example, a toggle mechanism 41. A fixed member 42 is provided on one side of the toggle mechanism 41, and a movable member 43 is provided on the other side. A rotating shaft 44 is connected to the toggle mechanism 41. A mold opening and closing servomotor 45 is connected to the rotating shaft 44. The mold opening and closing servomotor 45 is attached to the fixed member 42.

[0029] The mold opening and closing servomotor 45 rotates the rotary shaft 44 based on a control signal output from the control device 30. The mold opening and closing servomotor 45 rotates the rotary shaft 44 having a ball screw, thereby moving the movable member 43 relative to the fixed member 42 via the toggle mechanism 41. The mold opening and closing servomotor 45 moves the movable member 43 in a direction approaching the injection device 10, thereby moving the movable mold 61 toward the fixed mold 62. The mold opening and closing servomotor 45 moves the movable member 43 in a direction away from the injection device 10, thereby moving the movable mold 61 in a direction away from the fixed mold 62.

[0030] The opening and closing mechanism 40 further includes a mold thickness adjusting geared motor 46 attached to the fixed member 42. The mold thickness adjusting geared motor 46 adjusts the distance from the movable member 43 to the fixed member 42 by finely moving the toggle mechanism 41, thereby adjusting the mold thickness between the movable mold 61 and the fixed mold 62.

[0031] The ejector unit 50 includes an ejector pin 51. The ejector pin 51 is attached to the movable member 43 and passes through a movable mold 61 to be movable relative to the movable member 43. The movement of the ejector pin 51 passing through the movable mold 61 and moving relative to the movable member 43 is an ejection operation for ejecting a molded product that has been cooled and molded in the mold 60. The ejector pin 51 is attached to an ejector device 52. An ejector servomotor 53 is connected to the ejector device 52.

[0032] The ejector servo motor 53 operates the ejector device 52 based on a control signal output from the control device 30, causing the ejector device 52 to perform an ejector operation. The ejector operation includes an ejection operation in which the molded product is ejected by the ejector pins 51. The molded product is ejected from the mold 60 by the ejector pins 51 performing the ejection operation.

[0033] The ejector servomotor 53 is provided with an ejector sensor 54. The ejector sensor 54 includes an ejector speed sensor 54A and an ejector torque sensor 54B. The ejector speed sensor 54A detects the speed of the ejector servomotor 53. The ejector torque sensor 54B detects the current value of the current supplied to the ejector servomotor 53 and calculates the torque applied to the ejector servomotor 53 based on the detected current value. The ejector sensor 54 outputs the detected speed torque of the ejector motor 53 (hereinafter referred to as the "ejector motor detection value") to a monitoring device 100 included in the control device 30.

[0034] The input / output device 70 in the control device 30 includes, for example, a touch panel having an input function that allows input operations by a worker or the like and a display function that displays information. The input / output device 70 displays, for example, a GUI (Graphical User Interface) switch, allowing input operations in response to the operation of the GUI switch by a worker or the like.

[0035] The input / output device 70 outputs an input signal corresponding to an input operation by an operator to the forming control device 90 and the monitoring device 100. The input operation includes, for example, an operation to specify sensitivity for setting a threshold value used for monitoring abnormalities in the monitoring device 100. The input / output device 70 is an example of an output interface.

[0036] The input / output device 70 displays information according to display signals output by the molding control device 90 and the monitoring device 100. The information according to the display signals includes, for example, information according to an alarm signal output by the monitoring device 100. The input / output device 70 functions as an alarm unit by displaying the alarm information.

[0037] The alarm device 80 includes, for example, a speaker and a lamp. In response to the alarm signal output by the monitoring device 100, the speaker outputs an alarm sound and the lamp lights up or flashes. The alarm device 80 functions as an alarm unit by outputting an alarm sound and lighting up or flashing the alarm lamp.

[0038] The molding control device 90 includes a hardware processor such as a CPU (Central Processing Unit) and a storage unit such as an HDD (Hard Disk Drive) or flash memory. The storage unit stores, for example, an operation program for controlling the injection unit 10 and the mold clamping unit 20 to automatically perform injection molding operations. The molding control device 90 executes the operation program using the processor, thereby outputting control signals to the injection unit 10 and the mold clamping unit 20 and causing the injection unit 10 and the mold clamping unit 20 to perform injection molding operations.

[0039] In the operation program, the operation time of the metering servo motor 14 (hereinafter referred to as the "metering motor operation time") and the operation time of the ejector servo motor 53 (hereinafter referred to as the ejector motor operation time) when the injection molding operation is performed are set. The metering motor operation time and the ejector motor operation time (hereinafter referred to as the "motor operation time") are the times required by the metering servo motor 14 and the ejector servo motor 53, respectively, for one shot in the injection molding operation. The molding control device 90 outputs an operation time signal including the set motor operation time to the monitoring device 100.

[0040] The monitoring device 100 monitors abnormalities occurring in the injection device 10 and the mold clamping device 20 while the molding control device 90 is causing the injection device 10 and the mold clamping device 20 to perform the injection molding operation. The monitoring device 100 includes, for example, a processor and a storage device similar to those of the molding control device 90. The monitoring device 100 may be a part of the molding control device 90.

[0041] 2 is a block diagram of a monitoring device 100 according to an embodiment. As shown in FIG. 2, the monitoring device 100 includes, for example, a reception unit 110, a sampling interval calculation unit 120, a sampling data acquisition unit 130, a standardized data generation unit 140, a threshold calculation unit 150, an alarm control unit 160, and a storage unit 180. The reception unit 110, the sampling interval calculation unit 120, the standardized data generation unit 140, the threshold calculation unit 150, and the alarm control unit 160 in the monitoring device 100 are realized, for example, by the above-mentioned processor executing a program stored in the storage unit 180.

[0042] The storage unit 180 is realized by, for example, the above-mentioned HDD or flash memory. In addition to the program to be executed by the processor, the storage unit 180 stores sampling data 181 and standardized data 182. The sampling data 181 is data collected during the injection molding operation of the injection unit 10 and the mold clamping unit 20. The standardized data 182 is data obtained by standardizing the sampling data 181.

[0043] The reception unit 110 receives a sensitivity designation corresponding to an input signal output by the input / output device 70. The reception unit 110 receives a motor operation time included in an operation time signal output by the molding control device 90. The reception unit 110 stores the received sensitivity designation and motor operation time in the storage unit 180.

[0044] The sampling interval calculation unit 120 calculates the sampling interval as a value obtained by multiplying the calculation cycle of a processor such as a CPU included in the monitoring device 100 by a predetermined integer, and as a time equal to or greater than the motor operation time stored in the storage unit 180. The sampling interval calculation unit 120 calculates the sampling interval for the metering motor detection values ​​and the sampling interval for the ejector motor detection values. The sampling interval calculation unit 120 calculates the time equal to or greater than the metering motor operation time stored in the storage unit 180 as the sampling interval for the metering motor detection values, and calculates the time equal to or greater than the ejector motor operation time as the sampling interval for the ejector motor detection values.

[0045] The sampling data acquisition unit 130 acquires, as sampling data, the metering motor detection value output by the metering sensor 15 and the ejector motor detection value output by the ejector sensor 54 while the injection molding machine 1 is performing injection molding. The sampling data acquisition unit 130 acquires the sampling data at the sampling interval calculated by the sampling interval calculation unit 120. The sampling data acquisition unit 130 acquires sampling data of a predetermined number of sampling points in order to generate standardized data.

[0046] Every time sampling data is acquired, the sampling data acquisition unit 130 stores it in the storage unit 180. The sampling data 181 stored in the storage unit 180 includes data stored by the sampling data acquisition unit 130 in the past, as well as data stored by the sampling data acquisition unit 130 in the past.

[0047] The standardized data generation unit 140 generates standardized data 182 by standardizing the sampling data 181 stored in the storage unit 180. The standardized data generation unit 140 sequentially generates the standardized data 182 by performing calculations at the calculation cycle of a processor such as a CPU. The standardized data generation unit 140 stores the generated standardized data 182 in the storage unit 180.

[0048] The threshold calculation unit 150 calculates a threshold for determining whether to output an alarm signal based on past sampling data 181 stored in the storage unit 180. The threshold calculation unit 150 calculates a plurality of thresholds that change according to the progress of automatic operation of the injection molding machine 1. For example, the threshold calculation unit 150 calculates an initial monitoring threshold to be used in the early stage of automatic operation, for example, within 10 shots after the start of automatic operation, and a steady-state monitoring threshold to be used after 10 shots have been performed. When calculating the steady-state monitoring threshold, the threshold calculation unit 150 calculates a value according to the sensitivity specified by an operator or the like by operating the input / output device 70 as the steady-state monitoring threshold.

[0049] The alarm control unit 160 compares the standardized data generated by the standardized data generation unit 140 with the threshold value calculated by the threshold value calculation unit 150 to monitor abnormalities related to the metering servo motor 14 and the ejector servo motor 53. When the standardized data exceeds the threshold value, the alarm control unit 160 determines that an abnormality has occurred and executes alarm control, causing the molding control device 90, the input / output device 70, and the alarm device 80 to execute abnormality processing.

[0050] The alarm control unit 160 outputs an alarm signal to the input / output device 70 and the alarm device 80 as alarm control, and also outputs an operation stop signal to the molding control device 90. When the alarm signal is output, the input / output device 70 and the alarm device 80 notify the operator of the occurrence of the abnormality by displaying the abnormality on a touch panel, outputting an alarm sound, turning on or blinking a lamp, etc. When the operation stop signal is output, the molding control device 90 stops all or part of the injection molding machine 1, including the metering servomotor 14 and the ejector servomotor 53, as abnormality processing.

[0051] Next, we will explain the processing executed by the monitoring device 100. While the injection molding machine 1 is being automatically operated, the monitoring device 100 monitors abnormalities in the operation of the metering servo motor 14 and the ejector servo motor 53 provided in the injection molding machine, and automatically sets (adjusts) a threshold value for determining whether an abnormality has occurred.

[0052] Immediately after automatic operation is started, the monitoring device 100 collects sampling data without monitoring for abnormalities. After a certain period of time has passed, for example, after 10 molding shots have been completed, a monitoring level is determined and abnormality monitoring is performed. The monitoring levels are set to an initial monitoring level immediately after the start of the above monitoring, and a steady monitoring level to which the system transitions after monitoring at the initial monitoring level has been completed. The initial monitoring level is an example of a first monitoring level, and the steady monitoring level is an example of a second monitoring level.

[0053] 3 and 4 are flowcharts showing an example of a procedure for monitoring an abnormality in the monitoring device 100. When automatic operation of the injection molding machine 1 is started, automatic operation of the monitoring device 100 is also started at the same time (step S101). When automatic operation is started, the monitoring device 100 determines a sampling interval (sampling period), which is the interval (period) for acquiring sampling data (step S103). The procedure for determining the sampling interval will be described below.

[0054] 5 is a flowchart showing an example of a procedure for determining a sampling interval in the monitoring device 100. To determine the sampling interval, the monitoring device 100 receives and acquires the motor operation time output by the molding control device 90 at the receiving unit 110 (step S201). The receiving unit 110 stores the acquired motor operation time in the storage unit 180.

[0055] Next, the sampling interval calculation unit 120 calculates the time a during which sampling can be performed during the entire time while the metering servomotor 14 and the ejector servomotor 53 perform one shot of molding (hereinafter referred to as "total data obtainable time") (step S203). The sampling interval calculation unit 120 calculates the total data obtainable time a using the following formula (1) based on the motor operation time Ot obtained by the reception unit 110 and the number of sampling points N obtained by the sampling data acquisition unit 130. a=Ot / N (1)

[0056] Next, the monitoring device 100 sets the count value i1 of the first counter (hereinafter referred to as the "first count number") to an "initial value (=1)" (step S205). The first counter is a counter that counts the number of times that a candidate interval (hereinafter referred to as the sampling interval candidate) b at which sampling data can be acquired by a processor has been calculated. Next, the sampling interval calculation unit 120 calculates the sampling interval candidate b using the following equation (2) based on the first count number i1 and the calculation cycle Ct of a processor such as a CPU provided in the monitoring device 100 (step S207). b = i1 × Ct (2)

[0057] Next, the sampling interval calculation unit 120 determines whether the sampling interval candidate b is equal to or greater than the all-data-acquirable time a (step S209). If it is determined that the sampling interval candidate b is not equal to or greater than the all-data-acquirable time a (step S209: NO), the sampling interval calculation unit 120 increments the first counter (+1) (step S211) and returns the process to step S207.

[0058] If it is determined that sampling interval candidate b is equal to or greater than all data obtainable time a (step S209: YES), the sampling interval calculation unit 120 sets sampling interval candidate b as sampling interval T (step S213). By setting sampling interval T in this manner, the smallest value among values ​​obtained by multiplying the processor's calculation cycle by a predetermined integer and that is equal to or greater than the motor operation time becomes the sampling interval. Thereafter, the monitoring device 100 ends the processing shown in FIG. 5.

[0059] For example, in the case of the weighing servo motor 14, under the conditions of motor operating time Ot = 13892 ms, number of sampling points N = 8192, and processor operation cycle Ct = 0.888 ms, the total data obtainable time a is 1.69580 ms. In this case, if the first count number i1 = 1, then the sampling interval candidate b = 1 × 0.888 = 0.888 ms, and so the sampling interval candidate b is less than the total data obtainable time a.

[0060] In this case, the first counter is incremented to first count number i1 = 2. When first count number i1 = 2, candidate sampling interval b = 2 × 0.888 = 1.776 ms, and candidate sampling interval b ≧ all data obtainable time a. In this case, candidate sampling interval b = 1.776 ms is set as the sampling interval T.

[0061] 3, after determining the sampling interval, the monitoring device 100 sets the count value i2 of the second counter (hereinafter referred to as the "second count number") to an "initial value (=1)" (step S105). The second counter is a counter that counts the number of shots in the injection molding machine 1 when the monitoring level is not set (when abnormality monitoring is not being performed).

[0062] Next, the sampling data acquisition unit 130 acquires sampling data at the sampling interval T calculated by the sampling interval calculation unit 120 as initial data (step S107) and stores the data in the storage unit 180. The sampling data acquisition unit 130 continues to acquire sampling data at the sampling interval T thereafter and stores the data in the storage unit 180. Next, the standardized data generation unit 140 generates standardized data based on the initial data acquired by the sampling data acquisition unit 130 and stored in the storage unit 180 (step S109).

[0063] The standardized data is, for example, a value obtained by dividing by the average deviation the deviation between the value of the sampling data acquired by the sampling data acquisition unit 130 and the average value of the past sampling data stored in the storage unit 180. The acquisition of the initial data and the generation of the standardized data are repeated until one shot is completed (step S111).

[0064] Next, the sampling data acquiring unit 130 determines whether the second count number i2=10 (step S113). If it is determined that the second count number i2=10 is not reached (step S113: NO), the sampling data acquiring unit 130 increments the second count number i2 (+1) (step S115) and returns the process to step S107.

[0065] The sampling data acquisition unit 130 repeats this process until the second count number i2=10, thereby acquiring sampling data for 10 shots as initial data and generating standardized data. In this embodiment, the monitoring device 100 does not start monitoring for abnormalities while acquiring the initial data. The monitoring device 100 may also perform abnormality monitoring while acquiring the initial data.

[0066] In step S113, if the sampling data acquisition unit 130 determines that the second count number i2=10 (step S113: YES), the threshold calculation unit 150 calculates the initial monitoring threshold (step S117). The threshold calculation unit 150 calculates the initial monitoring threshold THi by the following equation (3), for example, based on the sensitivity n and the maximum value Sm of the standardized data accepted by the acceptance unit 110. THi = n × Sm (3)

[0067] The sensitivity n input by an operator or the like to the input / output device 70 and accepted by the accepting unit 110 is set to, for example, three levels of sensitivity: high sensitivity n1, medium sensitivity n2, and low sensitivity n3. The relationship between the high sensitivity n1, medium sensitivity n2, and low sensitivity n3 is high sensitivity n1<medium sensitivity n2<low sensitivity n3, and the higher the sensitivity, the easier it is to determine that an abnormality has occurred.

[0068] Next, the monitoring device 100 sets the count value i3 of the third counter (hereinafter referred to as the "third count number") to the "initial value (=1)" (step S119). The third counter is a counter that counts the number of shots in the injection molding machine 1 when the monitoring level is the initial monitoring.

[0069] 4, the monitoring device 100 sets the monitoring level to the initial monitoring level (step S121). Next, the standardized data generator 140 generates standardized data based on the sampling data acquired by the sampling data acquirer 130 and stored in the storage unit 180 (step S123). Next, the alarm controller 160 determines whether the integrated value of the standardized data generated by the standardized data generator 140 is equal to or greater than the initial monitoring threshold calculated by the threshold calculator 150 (step S125).

[0070] If it is determined that the integrated value of the standardized data generated by the standardized data generation unit 140 is greater than or equal to the initial monitoring threshold calculated by the threshold calculation unit 150 (step S125: YES), the alarm control unit 160 outputs an alarm signal to the input / output device 70 and the alarm device 80 as alarm control, and outputs an operation stop signal to the molding control device 90, causing the input / output device 70, the alarm device 80, and the molding control device 90 to perform abnormality processing (step S300).

[0071] The standardized data generating unit 140 and the alarm control unit 160 repeat the processes of steps S123 and S125 until one shot is completed. In step S125, if it is not determined that the integrated value of the standardized data generated by the standardized data generating unit 140 is equal to or greater than the initial monitoring threshold calculated by the threshold calculating unit 150 (step S125: NO) and one shot is completed (step S127), the threshold calculating unit 150 determines whether the third count number i3 is equal to or greater than 10 (step S129).

[0072] If the threshold calculation unit 150 determines that the third count number i3 is not equal to or greater than 10 (step S129: NO), it increments the third count number i3 (+3) (step S131) ​​and returns the process to step S123.

[0073] When it is determined that the third count number i3 is equal to or greater than 10 (step S129: YES), the threshold calculation unit 150 determines whether the standardized data generated by the standardized data generation unit 140 is equal to or less than a reference value (step S133). The reference value is a reference for transitioning the monitoring level from the initial monitoring level to the normal monitoring level, and is a so-called normal monitoring transition reference value, which is determined in advance and stored in the storage unit 180. The reference value can be set, for example, by an operator performing an input operation on the input / output device 70.

[0074] If it is determined that the generated standardized data is not equal to or less than the reference value (exceeds the reference value) (step S133: NO), the threshold calculation unit 150 returns the process to step S131, increments the third count number i3 (step S131), and then the standardized data generation unit 140 generates standardized data (step S123). By returning the process to step S131, the number of shots until transition to the normal monitoring level increases. The number of shots at the initial monitoring level is an example of a specific number of times.

[0075] If it is determined that the generated standardized data is equal to or less than the reference value (step S133: YES), the threshold calculation unit 150 calculates the steady-state monitoring threshold THs (step S135). The threshold calculation unit 150 calculates the steady-state monitoring threshold THs using the following equation (4) based on, for example, the sensitivity n accepted by the acceptance unit 110 and the maximum value Sf of the standardized data generated under the steady-state monitoring level. THs = n × Sf (4)

[0076] Next, the monitoring device 100 sets the monitoring level to the steady-state monitoring level (step S137). Next, the standardized data generating unit 140 generates standardized data based on the sampling data acquired by the sampling data acquiring unit 130 and stored in the storage unit 180 (step S139). Next, the alarm control unit 160 determines whether the integrated value of the standardized data generated by the standardized data generating unit 140 is equal to or greater than the steady-state monitoring threshold calculated by the threshold calculating unit 150 (step S141).

[0077] If it is determined that the integrated value of the standardized data generated by the standardized data generation unit 140 is greater than or equal to the steady-state monitoring threshold calculated by the threshold calculation unit 150 (step S141: YES), the alarm control unit 160 proceeds to abnormality processing (step S300), outputs an alarm signal to the input / output device 70 and the alarm device 80, and outputs an operation stop signal to the molding control device 90.

[0078] If it is determined that the integrated value of the generated standardized data is not equal to or greater than the steady-state monitoring threshold calculated by the threshold calculation unit 150 (step S141: NO), the monitoring device 100 determines whether or not autonomous driving has ended (step S143). If it is determined that autonomous driving has not ended (step S143: NO), the monitoring device 100 returns the process to step S137 and continues monitoring for abnormalities. If it is determined that autonomous driving has ended (step S143: YES), the monitoring device 100 ends the process shown in FIG.

[0079] The monitoring device 100 of the embodiment calculates the sampling interval as a value obtained by multiplying the processor's calculation cycle by a predetermined integer, which is equal to or longer than the motor operation time. This allows for the acquisition of sampling data for the entire one shot, enabling highly accurate anomaly detection.

[0080] Furthermore, the monitoring device 100 of the embodiment collects sampling data without performing abnormality determination immediately after starting automatic operation of the injection molding machine 1, and sets different thresholds for the subsequent initial monitoring level and the subsequent steady monitoring level. Since thresholds are set for each monitoring level, highly accurate abnormality determination can be performed. Furthermore, thresholds can be set at multiple sensitivities, including high sensitivity, medium sensitivity, and low sensitivity, depending on the operation of the operator or the like operating the injection molding machine 1. Therefore, abnormalities in the injection molding machine 1 can be determined at a sensitivity that suits the user's needs.

[0081] Furthermore, when transitioning from the initial monitoring level to the regular monitoring level, the monitoring device 100 of the embodiment sets a reference value for the standardized data generated under the initial monitoring level, and if the standardized data exceeds the reference value, increases the number of shots in the initial monitoring level, for example, by 1. This allows transition to the regular monitoring level in a more stable state.

[0082] The monitoring device 100 of the embodiment performs abnormality determination and determines abnormalities related to the operation of the metering servo motor 14, thereby improving the stability of resin depopulation and preventing breakage of the screw 13. Furthermore, by determining abnormalities related to the operation of the ejector servo motor 53, it is possible to detect overpacking and short shots and prevent breakage of the ejector pin 51.

[0083] In the monitoring device 100 of the embodiment, the servo motors to be monitored for abnormalities are both the metering servo motor 14 and the ejector servo motor 53, but it may be only one of the servo motors. Alternatively, it may be another servo motor such as the injection servo motor 17, or a geared motor.

[0084] In the above embodiment, the torque of the servo motor is detected by calculating the torque applied to the servo motor from the current value of the current flowing through the servo motor, but the torque applied to the servo motor may also be detected (calculated) from a source other than the current. The voltage of the servo motor may be detected by a voltage sensor, and the torque applied to the servo motor may be calculated based on the voltage, or the torque applied to the servo motor may be directly detected by a strain sensor or the like.

[0085] The above-described monitoring device 100 has an internal computer system. The processes performed in the above-described monitoring method are stored in the form of a program in the storage unit 180, and the above processes are performed by executing this program. The program stored in the storage unit 180 may be stored in a computer-readable recording medium and read and executed by the monitoring device 100. Examples of computer-readable recording media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories. Alternatively, the computer program may be distributed to a computer via a communication line, and the computer that receives the distribution may execute the program. [Explanation of symbols]

[0086] 1 injection molding machine 10 Injection device 14 Metering servo motor 15 Weighing sensors 15A Speed ​​Sensor for Weighing 15B Torque Sensor for Weighing 20 Mold clamping device 30 Control device 51 Ejector pin 52 Ejector device 53 Ejector servo motor 54 Ejector sensor 54A Ejector speed sensor 54B Ejector torque sensor 70 Input / Output Devices 80 Alarm device 90 Molding control device 100 Monitoring equipment 110 Reception 120 Sampling interval calculation unit 130 Sampling data acquisition unit 140 Standardized Data Generation Department 150 Threshold calculation unit 160 Alarm control section 180 Storage section 181 Sampling Data 182 Standardized Data

Claims

1. A monitoring device for an injection molding machine that monitors abnormalities in the operation of a servo motor provided in the injection molding machine, a sampling data acquisition unit that acquires sampling data obtained by sampling at least one of the torque of the servo motor and the speed of the servo motor; a sampling interval calculation unit that calculates a sampling interval for acquiring the sampling data; a standardized data generating unit that generates standardized data by calculating the sampling data acquired at the calculated sampling intervals at a predetermined calculation period; an alarm control unit that outputs an alarm signal to an alarm device when it is determined that the integrated value of the standardized data exceeds a threshold value; the sampling interval calculation unit calculates the sampling interval as a value obtained by multiplying the calculation period by a predetermined integer, The sampling interval is equal to or longer than the operating time of the servo motor.

1. A monitoring device for an injection molding machine.

2. the sampling interval calculation unit calculates, as the sampling interval, a minimum value among values ​​obtained by multiplying the calculation period by a predetermined integer, the minimum value being equal to or greater than the operation time of the servo motor; The monitoring device for an injection molding machine according to claim 1.

3. the sampling data acquisition unit acquires the sampling data while the injection molding machine is performing injection molding, further comprising a threshold calculation unit that calculates the threshold based on the acquired sampling data; 3. The monitoring device for an injection molding machine according to claim 1 or 2.

4. the threshold calculation unit calculates, as the threshold, a value according to sensitivity based on a maximum value of the standardized data generated in the past; 4. The monitoring device for an injection molding machine according to claim 3.

5. Further, a reception unit that receives the designation of the sensitivity is provided.

5. The monitoring device for an injection molding machine according to claim 4.

6. the warning control unit determines whether the threshold is exceeded at any one of a first monitoring level and a second monitoring level transitioning from the first monitoring level, transitioning the monitoring level from the first monitoring level to the second monitoring level when an integrated value of the standardized data generated while a specific number of injection moldings are performed under the first monitoring level is equal to or less than a preset reference value; increasing the specific number of injection moldings when an integrated value of the standardized data generated during the execution of the specific number of injection moldings under the first monitoring level exceeds the reference value; The monitoring device for an injection molding machine according to any one of claims 1 to 5.

7. the standardized data generating unit generates the standardized data by dividing the deviation between the value of the acquired sampling data and the average value of the sampling data acquired in the past by the average deviation of the sampling data. The monitoring device for an injection molding machine according to any one of claims 1 to 6.

8. the servo motor rotates a screw that plasticizes the molding material in the injection molding machine; The monitoring device for an injection molding machine according to any one of claims 1 to 7.

9. The servo motor controls an ejector operation in the injection molding machine. The monitoring device for an injection molding machine according to any one of claims 1 to 7.

10. The warning control unit stops the operation of the servo motor as the warning control. The monitoring device for an injection molding machine according to any one of claims 1 to 9.

11. the alarm control unit causes the output interface to output an alarm; The monitoring device for an injection molding machine according to any one of claims 1 to 9.

12. a screw that plasticizes the molten molding material; a mold into which the plasticized molding material is injected; an ejector pin that ejects a molded product molded by the mold; a metering servomotor that rotates the screw; an ejector servomotor that causes the ejector pin to perform an ejection operation; and the monitoring device for an injection molding machine according to any one of claims 1 to 11. Injection molding machine.

13. A monitoring method for an injection molding machine for monitoring an abnormality in the operation of a servo motor provided in the injection molding machine, comprising: The computer obtaining sampling data obtained by sampling at least one of the torque of the servo motor and the speed of the servo motor; calculating a sampling interval for acquiring the sampling data; generating standardized data by calculating the sampling data acquired at the calculated sampling intervals at a predetermined calculation period; When it is determined that the integrated value of the standardized data exceeds a threshold value, an alarm signal is output to an alarm device; The computer calculating a value obtained by multiplying the calculation period by a predetermined integer as the sampling interval; The sampling interval is equal to or longer than the operating time of the servo motor. A monitoring method for an injection molding machine, comprising:

14. A program for causing a computer of a monitoring device for an injection molding machine to execute control for monitoring abnormalities related to the operation of a servo motor provided in the injection molding machine, The computer, obtaining sampling data obtained by sampling at least one of the torque of the servo motor and the speed of the servo motor; calculating a sampling interval for acquiring the sampling data; generating standardized data by calculating the sampling data acquired at the calculated sampling intervals at a predetermined calculation period; When it is determined that the integrated value of the standardized data exceeds a threshold value, an alarm device outputs an alarm signal; The computer, calculating a value obtained by multiplying the calculation period by a predetermined integer as the sampling interval; The sampling interval is equal to or longer than the operating time of the servo motor. A program characterized by:

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