Determination device

Abstract

To provide a determination device capable of accurately determining the time when the start-up of an extruder is completed.SOLUTION: There is provided a determination device including a waveform acquisition unit, a specific section detection unit, and a completion determination unit. The waveform acquisition unit acquires, from an extruder at a time of start-up, a waveform of an observation value, which is at least one of (a) a resin pressure in the extruder and (b) a load current value of a screw motor equipped in the extruder. The specific section detection unit detects a specific section in a waveform of an observed value that can be approximated by a linear expression whose absolute value of a slope is equal to or less than a threshold value. The completion determination unit determines that the start-up of the extruder is completed at a time that is a predetermined additional time after the time when the specific section appears.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a determination device. [Background technology]

[0002] Patent Document 1 describes an extruder. When starting up the extruder, an operator determines whether start-up is complete by reading the values ​​of a resin pressure gauge and a load current meter of a screw motor. Resin extruded from the extruder up until the time when start-up is determined to be complete is discarded without being used in products. Resin extruded from the extruder after the time when start-up is determined to be complete is used in products. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-109354 Summary of the Invention [Problem to be solved by the invention]

[0004] The time at which each worker determines that startup is complete varies. If the time at which startup is complete is too early, resin that should have been discarded will be used in the product. If the time at which startup is complete is too late, resin that could have been used in the product will be discarded.

[0005] In one aspect of the present disclosure, it is preferable to provide a determination device that can accurately determine the time when the start-up of the extruder is completed. [Means for solving the problem]

[0006] One aspect of the present disclosure is a determination device that includes: a waveform acquisition unit configured to acquire, from the extruder when the extruder is started up, a waveform of an observation value, which is at least one of (a) the resin pressure in the extruder and (b) the load current value of a screw motor equipped in the extruder; a specific section detection unit configured to detect, in the waveform of the observation value, a specific section that can be approximated to a linear equation whose absolute value of the slope is less than a threshold value; and a completion determination unit that determines that the start-up of the extruder is complete at a time that is a predetermined additional time after the time when the specific section appears.

[0007] The determination device according to one aspect of the present disclosure can accurately determine the time at which the start-up of the extruder is completed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is an explanatory diagram illustrating the configuration of an extruder. [Figure 2] FIG. 2 is a block diagram showing the configuration of a determination device. [Figure 3] 10 is a flowchart showing a process executed by a determination device. [Figure 4] FIG. 10 is an explanatory diagram showing times tn-1, tn, tn+1, additional time ΔT, and start-up completion time te in the waveform of observed values. [Figure 5] FIG. 1 is an explanatory diagram showing waveforms of observed values ​​at the time of starting up the extruder and thereafter. DETAILED DESCRIPTION OF THE INVENTION

[0009] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. First Embodiment 1. Configuration of Extruder 1 The configuration of the extruder 1 will be described with reference to Fig. 1. The extruder 1 is equipped with a hopper 3, a feeder motor 5, and a raw material feeder 7 as components for supplying the raw material 2. The raw material 2 is supplied to the hopper 3. The feeder motor 5 drives a screw 7A equipped in the raw material feeder 7. The raw material 2 supplied to the hopper 3 is sent by the screw 7A to a barrel section 9, which will be described later.

[0010] The extruder 1 is configured to extrude a resin and includes a barrel 9, a screw 11, a screw motor 13, and a head 15. The barrel 9 is a hollow, tubular member. The screw 11 is housed inside the barrel 9. The screw 11 is driven by the screw motor 13. The raw material 2 inside the barrel 9 is fed by the screw 11 in the direction of the head 15. The resin 16 produced from the raw material 2 inside the barrel 9 is extruded from the head 15 to the outside of the extruder 1.

[0011] The extruder 1 is equipped with measuring instruments. The measuring instruments detect various data necessary for control, etc. The measuring instruments include a screw motor ammeter 17 and a resin pressure gauge 19. The screw motor ammeter 17 repeatedly measures the load current value of the screw motor 13 at predetermined time intervals. The resin pressure gauge 19 repeatedly measures the resin pressure in the extruder 1 at predetermined time intervals. More specifically, the resin pressure gauge 19 repeatedly measures the resin pressure inside the barrel portion 9 at predetermined time intervals. The resin pressure gauge 19 may also measure the resin pressure in the head portion 15.

[0012] The extruder 1 is equipped with a heater 21 and a barrel cooling pump 23 as components for heating and cooling. The heater 21 heats the barrel portion 9 and the head portion 15. The barrel cooling pump 23 cools the barrel portion 9 and the head portion 15. The extruder 1 also includes a lubricating oil pump 25 and the like.

[0013] 2. Configuration of the determination device 101 The configuration of the determination device 101 will be described with reference to Fig. 2. The determination device 101 includes a control unit 103, a notification unit 105, and a display unit 107.

[0014] The control unit 103 includes a waveform acquisition unit 111 , a specific section detection unit 113 , a completion determination unit 115 , a display control unit 117 , and a notification control unit 119 . The waveform acquisition unit 111 acquires the waveform of the resin pressure in the extruder 1 from the resin pressure gauge 19. The waveform of the resin pressure is a set of values ​​of the resin pressure repeatedly measured at predetermined time intervals.

[0015] Furthermore, the waveform acquisition unit 111 acquires the waveform of the load current value of the screw motor 13 from the screw motor ammeter 17. The waveform of the load current value is a set of load current values ​​repeatedly measured at predetermined time intervals.

[0016] The specific section detection unit 113 performs a process of detecting a specific section. This process will be described later. The completion determination unit 115 determines the time when the start-up of the extruder 1 is completed (hereinafter referred to as the start-up completion time t e The details will be explained later.

[0017] The display control unit 117 performs display using the display unit 107. The operator of the extruder 1 can see the display. The displayed content includes the waveform of the resin pressure, the slope of the waveform, the waveform of the load current value of the screw motor 13, the slope of the waveform, etc. The display control unit 117 performs display when the extruder 1 starts up.

[0018] The notification control unit 119 issues a notification by sound and light using the notification unit 105. The operator of the extruder 1 can recognize the notification. The notification control unit 119 starts the notification at the start-up completion time t e is. The notification unit 105 includes a speaker that emits sound and a lamp that emits light. The display unit 107 includes a display that can display images. The display unit 107 is, for example, a touch panel.

[0019] 3. Start-up operation of Extruder 1 The operation of the extruder 1 at start-up is as follows. First, the heater 21 raises the temperature of the barrel section 9 and the head section 15 to the target temperature. Next, the raw material 2 is supplied to the hopper 3. Next, the raw material feeder 7 supplies the raw material 2 to the barrel section 9. Also, the screw 11 is rotated by the screw motor 13. The rotation speed of the screw 11 gradually increases. Next, the resin 16 starts to be extruded from the head section 15. At the start-up completion time t e The resin 16 extruded up to this point is not used in the manufacture of products and is discarded.

[0020] 4. Processing Executed by the Determination Device 101 The process executed by the determination device 101 when the extruder 1 is started up will be described with reference to FIGS.

[0021] In step 1 of FIG. 3, the waveform acquisition unit 111 acquires the waveform of the resin pressure in the extruder 1 from the resin pressure gauge 19. The waveform to be acquired is, as shown in FIG. n-1 From time t n Waveform W for the period up to n n is a natural number greater than or equal to 2.

[0022] time t n-1 is the time when the process of step 1 was last performed. n is the time when step 1 is performed. n-1 From time t n The length of the waveform W is, for example, 1 to 10 seconds. n For example, the resin pressure may include hundreds to thousands of measured values ​​of the resin pressure, where the resin pressure corresponds to an observed value.

[0023] In step 2, the specific section detection unit 113 performs a process of detecting a specific section as follows. The specific section detection unit 113 detects the waveform W acquired in the immediately preceding step 1 by, for example, the least squares method. n The approximate straight line is calculated as follows: The approximate straight line is a linear equation expressed by the following equation (1).

[0024] Equation (1) Y=aX+b In equation (1), X is the time, Y is the resin pressure value, a is the slope, and b is the Y-intercept.

[0025] The specific section detection unit 113 determines whether the calculated approximate line satisfies the following conditions 1 and 2. (Condition 1) The absolute value of the gradient a in equation (1) is equal to or less than a preset threshold value.

[0026] (Condition 2) Equation (1) and waveform W n The correlation coefficient with is equal to or greater than a preset threshold. If both conditions 1 and 2 are satisfied, the specific section detection unit 113 detects the waveform W n If either condition 1 or 2 is not satisfied, the specific section detection unit 113 detects the waveform W n is not detected as a specific section. Note that satisfying both conditions 1 and 2 means that the waveform W n corresponds to the fact that the absolute value of the gradient can be approximated to a linear expression that is equal to or smaller than a threshold value.

[0027] In step 3, the specific section detection unit 113 determines whether or not a specific section was detected in the immediately preceding step 2. If it is determined that a specific section was detected, the process proceeds to step 4. If it is determined that a specific section was not detected, the process returns to step 1.

[0028] When returning to step 1, the waveform acquisition unit 111 acquires the resin pressure from the resin pressure gauge 19 at time t n From time t n+1 Waveform W for the period up to n+1 At time t n+1 is the time t n This is the time to process step 1 after step 1. After step 1, steps 2 and 3 are similarly processed.

[0029] In step 4, the completion determination unit 115 determines whether the time tn The time after the predetermined additional time ΔT from the start-up completion time t e The completion determination unit 115 determines whether the start-up completion time t e At time t n corresponds to the time when the specific section appears.

[0030] The notification control unit 119 detects the start-up completion time t e When the start-up completion time t e The resin 16 extruded after the start-up completion time t e The resin 16 extruded before this can be discarded.

[0031] 5. Effects of the Determination Device 101 (1A) The determination device 101 determines whether the startup completion time t e The reason for this is as follows.

[0032] The resin pressure waveform W at the time of start-up of the extruder 1 and thereafter is as shown in Figure 5. The resin pressure waveform W is divided into Section A and Section B. In Section A, the resin pressure rises, then reaches a maximum value, and then drops. In Section A, the quality of the extruded resin 16 is not stable, and start-up of the extruder 1 is not complete.

[0033] Section B follows section A. In section B, the resin pressure is stable. In section B, the quality of the extruded resin 16 is stable, and the start-up of the extruder 1 has already been completed.

[0034] In section A, at least one of conditions 1 and 2 is not satisfied, so a specific section is not detected. In the section A where the resin pressure rises and falls, the absolute value of the slope a in formula (1) becomes large, so condition 1 is not satisfied. Also, in section A, near the maximum value, the relationship between formula (1) and waveform W n Since the correlation coefficient with becomes small, condition 2 is not satisfied.

[0035] At the beginning of section B, both conditions 1 and 2 are satisfied, and a specific section is detected. The determination device 101 detects the specific section at the beginning of section B, and determines the start-up completion time t e can be accurately determined.

[0036] (1B) In the first embodiment, the observed value is the resin pressure in the extruder 1. Therefore, the determination device 101 determines whether the resin pressure is equal to or smaller than the start-up completion time t e can be determined more accurately.

[0037] Second Embodiment 1. Differences from the first embodiment The second embodiment has the same basic configuration as the first embodiment, so differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference will be made to the preceding description.

[0038] In the first embodiment described above, the observed value is the resin pressure in the extruder 1. In contrast, in the second embodiment, the observed value is the load current value of the screw motor 13, which is different from the first embodiment.

[0039] 2. Processing executed by the determination device 101 The determination device 101 basically performs the same processing as in the first embodiment. However, the determination device 101 uses the waveform of the load current value of the screw motor 13 instead of the waveform of the resin pressure in the extruder 1. The waveform of the load current value of the screw motor 13 changes in the same way as the waveform of the resin pressure in the extruder 1, so it is possible to detect a specific section, as in the first embodiment.

[0040] 3. Effects of the Determination Device 101 According to the second embodiment described above in detail, the effect (1A) of the first embodiment described above is achieved.

[0041] Third Embodiment 1. Differences from the first embodiment The third embodiment has the same basic configuration as the first embodiment, so differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference will be made to the preceding description.

[0042] In the first embodiment described above, the observed value was the resin pressure in the extruder 1. In contrast, the third embodiment differs from the first embodiment in that the observed value is both the resin pressure in the extruder 1 and the load current value of the screw motor 13.

[0043] 2. Processing executed by the determination device 101 As in the first embodiment, the determination device 101 detects a specific section based on the waveform of the resin pressure in the extruder 1. The detected specific section is set as the specific section based on the resin pressure.

[0044] As in the second embodiment, the determination device 101 detects a specific section based on the waveform of the load current value of the screw motor 13. The detected specific section is set as the specific section based on the load current value.

[0045] The determination device 101 determines the time after the additional time ΔT from the later of the time when the specific section based on the resin pressure appears and the time when the specific section based on the load current value appears as the start-up completion time t e The determination device 101 determines the start-up completion time t e At this time, it is determined that the start-up of the extruder 1 is completed.

[0046] 3. Effects of the Determination Device 101 According to the third embodiment described above in detail, the effect (1A) of the first embodiment described above is achieved, and further, the following effect is achieved.

[0047] (3A) In the third embodiment, the observed values ​​are both the resin pressure in the extruder 1 and the load current value of the screw motor 13. Therefore, the determination device 101 determines whether the start-up completion time t e can be determined more accurately.

[0048] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0049] (1) The method for detecting the specific section in step 2 may be other methods. For example, n If the time that satisfies condition 1 continues for a predetermined time or more, the waveform W n can be detected as a specific section.

[0050] (2) Waveform W n If is a specific section, the start-up completion time t e is the time t n-1 In this case, the time t n-1 corresponds to the time when a specific section appears. e is the time t n-1 and time t n In this case, the time t n-1 and time t n The time between these corresponds to the time at which the specific section appears.

[0051] (3) The control unit 103 and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit 103 and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit 103 and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium. The method for implementing the functions of each component included in the control unit 103 does not necessarily need to include software; all of the functions may be implemented using one or more hardware components.

[0052] (4) The function of one component in each of the above embodiments may be shared among multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Furthermore, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0053] (5) In addition to the above-described determination device 101, the present disclosure can also be realized in various forms, such as a system including the determination device 101 as a component, a program for causing a computer to function as the determination device 101, a non-transient physical recording medium such as a semiconductor memory on which the program is recorded, and a method for manufacturing a resin. [Explanation of symbols]

[0054] 1...extruder, 2...raw material, 3...hopper, 5...feeder motor, 7...raw material feeder, 7A...screw, 9...barrel section, 11...screw, 13...screw motor, 15...head section, 16...resin, 21...heater, 23...barrel cooling pump, 25...lubricating oil pump, 101...determination device, 103...control unit, 105...alarm unit, 107...display unit, 111...waveform acquisition section, 113...specific section detection section, 115...completion determination section, 117...display control section, 119...alarm control section

Claims

1. a waveform acquisition unit configured to acquire, from the extruder at the time of start-up of the extruder, a waveform of an observation value that is at least one of (a) a resin pressure in the extruder and (b) a load current value of a screw motor included in the extruder; a specific section detection unit configured to detect a specific section in the waveform of the observed value that can be approximated by a linear expression whose absolute value of slope is equal to or less than a threshold; a completion determination unit that determines that the start-up of the extruder is completed at a time that is a predetermined additional time after the time when the specific section appears; A determination device comprising:

2. The determination device according to claim 1, The observed value is (a). Judgment device.

3. 3. The determination device according to claim 1 or 2, the specific section detection unit is configured to detect the specific section for each of the waveform (a) and the waveform (b); the completion determination unit is configured to determine that the start-up of the extruder is completed at a time that is the additional time after the later of a time when the specific section detected from the waveform (a) appears and a time when the specific section detected from the waveform (b) appears. Judgment device.

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