Lifetime prediction method for injection component and lifetime prediction system for injection component

Abstract

According to the present disclosure, it is possible to provide an injection component life prediction method and an injection component life prediction system capable of more accurately predicting the degree of deterioration (life) of an injection component.SOLUTION: An injection component life prediction method according to the present disclosure is an injection component life prediction method including acquiring acceleration in a direction perpendicular to an injection direction of an injection component, and predicting a degree of deterioration of the injection component based on a number of cast shots of the injection component estimated from a representative value of a predetermined range included in a temporal waveform of the acceleration and a data group of representative values acquired in advance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method and system for predicting the lifespan of an injection part. [Background technology]

[0002] Patent Document 1 discloses a method for predicting the life of parts that constitute an injection device of a die-casting machine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-157366 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have found the following problems. The prediction method disclosed in the above-mentioned Patent Document 1 predicts the lifespan of the parts (injection parts) that make up the injection device from the casting pressure of the casting equipment, and it was difficult to accurately predict the degree of deterioration (lifespan) of the injection parts.

[0005] The present disclosure has been made in consideration of the above circumstances, and provides a method and system for predicting the lifespan of an injection part that can more accurately predict the degree of deterioration (lifespan) of an injection part. [Means for solving the problem]

[0006] The method for predicting the life of an injection part according to the present disclosure includes: A method for predicting a lifespan of an injection part, comprising: obtaining an acceleration in a direction perpendicular to an injection direction of the injected part; The degree of deterioration of the injection part is predicted based on the number of shots already cast of the injection part estimated from a representative value of a predetermined range included in the time-varying waveform of the acceleration and a data group of the representative values ​​previously acquired.

[0007] The method for predicting the lifespan of an injection part according to the present disclosure can estimate the number of shots cast by comparing a representative value within a predetermined range included in the time-varying waveform of acceleration in a direction perpendicular to the injection direction of the injection part with past performance values ​​of the representative value, thereby enabling accurate prediction of the deterioration degree (lifespan) of the injection part.

[0008] The injection part life prediction system according to the present disclosure comprises: A system for predicting the life of an injection part, comprising: an acceleration sensor attached to the injection component that measures acceleration in a direction perpendicular to the injection direction of the injection component; and a control unit that predicts a degree of deterioration of the injection component, The control unit acquires the acceleration measured by the acceleration sensor, The degree of deterioration of the injection part is predicted based on the number of shots of the injection part that have been cast, which is estimated from a representative value of a predetermined range included in a time-varying waveform that can be obtained from the acceleration and a data group of the representative values ​​that has been obtained in advance.

[0009] The injection part life prediction system according to the present disclosure can estimate the number of shots cast by comparing a representative value within a predetermined range included in the time-varying waveform of acceleration in a direction perpendicular to the injection direction of the injection part with past performance values ​​of the representative value, thereby enabling accurate prediction of the deterioration degree (lifespan) of the injection part. [Effects of the Invention]

[0010] The present disclosure provides a method and system for predicting the lifespan of an injection part that can more accurately predict the degree of deterioration (lifespan) of an injection part. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram of a life prediction system for an injection part according to a first embodiment. [Figure 2] 1 is a conceptual diagram of a life prediction system for an injection part according to a first embodiment. [Figure 3] 4 is a flowchart of a method for predicting a life span of an injection part according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing an example of a waveform obtained from a value of an acceleration sensor. [Figure 5] FIG. 1 is an explanatory diagram (graph) for explaining a method for predicting the number of cast shots. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present disclosure will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary.

[0013] (Embodiment 1) <Injection part life prediction system> The configuration of the injection part life prediction system according to the first embodiment will be described below with reference to Fig. 1 and Fig. 2. Fig. 1 is a block diagram of the injection part life prediction system according to the first embodiment. Fig. 2 is a conceptual diagram of the injection part life prediction system according to the first embodiment. Note that Fig. 2 shows only a portion of the injection part, and details are omitted as appropriate.

[0014] 1, a life prediction system 10 for an injected part includes an acceleration sensor 11 and a control unit 12. The acceleration sensor 11 measures the acceleration in a direction perpendicular to the injection direction of the injected part. During a casting shot, vibrations are applied in a direction perpendicular to the injection direction of the injected part, so the acceleration sensor 11 measures the acceleration in the direction perpendicular to the injection direction of the injected part.

[0015] As shown in FIG. 2, the acceleration sensor 11 is attached to an injection part 13. The injection part 13 is, for example, an injection plunger of a die-casting machine. Although not shown in FIG. 2, the acceleration sensor 11 has a built-in transmitter. The acceleration sensor 11 (transmitter) transmits the acquired acceleration value to the control unit 12. That is, the control unit 12 receives the acceleration value from the acceleration sensor 11 (transmitter) via the receiver 15. The communication method between the transmitter and receiver may be wireless or wired.

[0016] The control unit 12 shown in FIG. 1 predicts the degree of deterioration (lifespan) of the injection part 13 (see FIG. 2). The method for predicting the lifespan of the injection part will be described in detail later. The control unit 12 is a computer that can predict the degree of deterioration (lifespan) of the injection part. As shown in FIG. 2, the control unit 12 may also be a computer that can display a time-varying waveform that can be obtained from the value of the acceleration sensor.

[0017] <Method for predicting the life of injection parts> Next, a method for predicting the lifespan of an injection part according to the first embodiment will be described with reference to Fig. 3 to Fig. 5. Fig. 3 is a flowchart of the method for predicting the lifespan of an injection part according to the first embodiment. Fig. 4 is a diagram showing an example of a waveform obtained from the value of an acceleration sensor. Fig. 5 is an explanatory diagram (graph) for explaining a method for predicting the number of cast shots.

[0018] <Preparation process> First, the preparation process in the method for predicting the lifespan of an injection molded part will be described with reference to Fig. 4 and Fig. 5. As shown in Fig. 4, when the control unit 12 acquires the acceleration sensor value from the acceleration sensor 11, it displays a waveform. In Fig. 4, the horizontal axis represents time and the vertical axis represents acceleration. In other words, the waveform shown in Fig. 4 can be said to be a time-varying waveform that can be acquired from the acceleration sensor value.

[0019] The waveform shown in Figure 4 shows a portion of the waveform (one-cycle waveform) at a predetermined number of casting shots. The predetermined number of casting shots is the number counted by the die-casting machine (casting equipment). The waveform shown in Figure 4 may be any portion of the waveform (one-cycle waveform) at a predetermined number of casting shots, as long as it includes a portion exceeding a certain peak value. The waveform shown in Figure 4 may also be a waveform at a time when the injected part is moving forward or backward in the waveform (one-cycle waveform) at a predetermined number of casting shots.

[0020] Next, a representative value within a predetermined range A1 of the waveform shown in Figure 4 is calculated. The predetermined range A1 is a range that can be selected arbitrarily. The representative value is a unique numerical value obtained from the waveform shown in Figure 4 within the predetermined range A1. The representative value may be, for example, the average value of the waveform amplitude, the standard deviation, or the width between the maximum and minimum peaks. The representative value may also be, for example, the maximum or minimum value of the waveform amplitude.

[0021] Here, we will continue the explanation assuming that multiple standard deviations are calculated from the waveforms (waveforms in FIG. 4) at a predetermined number of casting shots. For example, suppose the standard deviation is 0.05 after 10,000 shots and 0.15 after 30,000 shots. From these two actual values, a data set S1 shown in FIG. 5 is created.

[0022] For simplicity, the data group S1 is created from two standard deviations, but the present invention is not limited to this, and a data group (for example, data group S1 in FIG. 5) of representative values ​​may be created from a plurality of representative values ​​(for example, the standard deviations in FIG. 4). The more actual values ​​there are, the higher the accuracy of the number of cast shots of the injected part estimated by the control unit (described later).

[0023] <Lifespan prediction process> Next, a method for predicting the life of an injection part will be described with reference to FIGS.

[0024] First, the acceleration sensor measures the acceleration in a direction perpendicular to the injection direction of the injected part (step ST1), and then transmits the acquired acceleration value to the control unit.

[0025] Next, when the control unit acquires the acceleration from the acceleration sensor, the control unit acquires a waveform over time from the acceleration (step ST2). More specifically, the control unit acquires the waveform shown in FIG.

[0026] Next, the control unit calculates a representative value in the predetermined range A1 of the waveform shown in Fig. 4 (step ST3). Here, the representative value is the standard deviation, and it is assumed that the control unit calculates that the standard deviation in the predetermined range A1 of the waveform shown in Fig. 4 is 0.1.

[0027] Next, the control unit estimates the number of shots that have been cast for the injected part from the standard deviation of 0.1 included in the waveform in FIG. 4 and the data group of the standard deviation (S1 in FIG. 5) that has been acquired in advance (step ST4). More specifically, when the standard deviation is 0.1 based on the data group S1 in FIG. 5, the number of shots that have been cast is 20,000. Therefore, the control unit estimates that the number of shots that have been cast for the injected part is equivalent to 20,000.

[0028] Next, the control unit predicts the deterioration degree (lifespan) of the injection part based on the estimated number of cast shots (step ST5). For example, the control unit predicts that the deterioration degree of the injection part is equivalent to 20,000 cast shots. For example, the control unit calculates the difference between the calculated number of cast shots and a predetermined number of cast shots.

[0029] More specifically, if the number of cast shots that require replacement of an injection part is 40,000, the control unit subtracts 20,000 from 40,000 and predicts that the injection part has a lifespan of 20,000. As another example, if the number of cast shots that require replacement of an injection part is 15,000, the control unit predicts that the injection part has already reached the end of its lifespan. Note that the computer shown in Figure 2 may be configured to reflect the waveform shown in Figure 4 and the graph shown in Figure 5 in real time.

[0030] Here, the die-casting machine (casting equipment) counts the number of shots of each injection part that have been cast. Generally, the die-casting machine (casting equipment) uses injection parts until the number of shots counted reaches a predetermined number of shots. The predetermined number of shots is a guideline for maintenance or replacement of the injection parts, and is determined based on past experience.

[0031] Furthermore, depending on conditions such as the casting pressure, injection speed, and high-speed section, as well as the structure of the injection parts, stress may be applied not only in the injection direction but also in a direction perpendicular to the injection direction. Therefore, the degree of deterioration of the injection parts may correspond to a number of shots greater than the number of shots counted in the casting equipment. In such cases, if the injection parts are used continuously, they may suddenly break before reaching the predetermined number of shots. Furthermore, replacing the injection parts when they break would require a production line interruption, resulting in a decrease in output.

[0032] On the other hand, depending on the casting pressure, the stress load on the injection parts may be small. The number of shots cast for the injection parts may correspond to a number smaller than the number of shots counted in the casting equipment. In such a case, if the injection parts are continuously used and replaced after reaching a predetermined number of shots, the injection parts that are still usable will be replaced, which will increase the cost of the injection parts.

[0033] In contrast, the method for predicting the lifespan of an injection part according to the first embodiment can predict the number of shots cast by comparing a predetermined representative value obtained from the value of an acceleration sensor that detects vibrations in a direction perpendicular to the injection direction of the injection part with past actual values. In other words, it is possible to more accurately predict the degree of deterioration (lifespan) of the injection part. This can improve the yield of the casting equipment and reduce the cost of the injection part.

[0034] Furthermore, some or all of the processing in the control unit 12 described above can be implemented as a computer program. Such a program can be stored on various types of non-transitory computer-readable media and provided to a computer. Non-transitory computer-readable media include various types of tangible recording media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, and semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs (Random Access Memory)). The program may also be provided to a computer by various types of temporary computer-readable media. Examples of temporary computer-readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable media can provide the program to a computer via wired communication paths such as electric wires and optical fibers, or via wireless communication paths.

[0035] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0036] 10 Life Prediction System 11 Acceleration sensor 12 Control Unit 13 Injection parts 15 Receiver A1 specified range

Claims

1. A method for predicting a lifespan of an injection part, comprising: obtaining an acceleration in a direction perpendicular to an injection direction of the injected part; predicting a degree of deterioration of the injection part based on a number of shots of the injection part that has been cast, the number being estimated from a representative value of a predetermined range included in the waveform of the acceleration over time and a data group of the representative values ​​that has been acquired in advance; Methods for predicting the life of injection parts.

2. A system for predicting the life of an injection part, comprising: an acceleration sensor attached to the injection component that measures acceleration in a direction perpendicular to the injection direction of the injection component; and a control unit that predicts a degree of deterioration of the injection component, The control unit acquires the acceleration measured by the acceleration sensor, predicting a degree of deterioration of the injection part based on a number of shots of the injection part that has been cast, the number being estimated from a representative value of a predetermined range included in a time-varying waveform obtainable from the acceleration and a data group of the representative values ​​that have been obtained in advance; Life prediction system for injection parts.

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