Wear condition measuring device and die casting machine

Abstract

The present wear condition measuring device is a device for measuring the wear condition of an injection sleeve and a plunger head in a die casting machine provided with a mold holding portion, an injection sleeve, a plunger head, and an injection drive portion that moves the plunger head in and out, and includes an elastic wave measuring portion that measures an elastic wave transmitted in the injection sleeve when the plunger head is moved, and a determination portion that determines the wear condition in at least one of the injection sleeve and the plunger head based on an output signal of the elastic wave measuring portion.

Description

Technical Field

[0001] This invention relates to a wear condition measuring device and a die casting machine, and particularly to a wear condition measuring device in a die casting machine that injects molten material from an injection sleeve into a mold via a plunger head, and a die casting machine equipped with a wear condition measuring device. Background Technology

[0002] Previously, die-casting machines were known to inject molten metal from an injection sleeve into a mold via a plunger head. For example, such a die-casting machine was disclosed in Japanese Patent Application Publication No. 2017-104871.

[0003] In the aforementioned Japanese Patent Application Publication No. 2017-104871, a die-casting machine was disclosed that supplies molten metal into an injection sleeve and uses a cylinder to move a plunger head, which is slidably disposed in the injection sleeve, forward at low and high speeds, thereby injecting the molten metal into the cavity of a mold.

[0004] Japanese Patent Application Publication No. 2017-104871 discloses the following: If molten metal is repeatedly injected, wear occurs in the plunger head, and solidified metal particles are generated within the injection sleeve, causing fluctuations in the injection speed, a condition known as jamming. Furthermore, Japanese Patent Application Publication No. 2017-104871 discloses the following: Multiple evaluation intervals are set within the movement range of the plunger head; the average and maximum casting pressure values ​​for each evaluation interval are calculated; and the degree of jamming is evaluated by comparing the differences between these values ​​and preset values ​​for each evaluation interval.

[0005] Prior art literature Patent documents Patent document 1: Japanese Patent Application Publication No. 2017-104871. Summary of the Invention

[0006] The problem that the invention aims to solve The main cause of the "jamming" described in Japanese Patent Application Publication No. 2017-104871 is wear on one or both of the outer circumferential surface of the plunger head and the inner circumferential surface of the injection sleeve, which serve as the sliding surface. Besides jamming, if the gap between the plunger head and the injection sleeve increases due to wear of the sliding surface, a phenomenon called backflow, where pressure leaks from the gap, also occurs. Such abnormalities in sliding parts as jamming or backflow are major causes of product quality degradation, leading to the replacement of worn plunger heads and injection sleeves. It is desirable to monitor the wear of the plunger head and injection sleeve with high precision so that it is possible to determine at an appropriate time whether the sliding parts need to be replaced before the wear progresses to the point of affecting product quality.

[0007] However, the evaluation method disclosed in Japanese Patent Application Publication No. 2017-104871 indirectly monitors the process by measuring the change in sliding resistance caused by jamming as a change in injection pressure. This makes it difficult to capture minute changes that occur without altering the injection pressure. In other words, when changes in injection pressure caused by actual jamming are monitored, there is a high probability of producing products with degraded quality or substandard products that do not meet quality standards.

[0008] The present invention was made to solve the problems described above. One object of the present invention is to provide a wear condition measuring device and a die-casting machine capable of accurately measuring the wear of the plunger head and the injection sleeve.

[0009] Solution for solving the problem To achieve the aforementioned objectives, the inventors of this application conducted in-depth research and discovered that when the plunger head slides within the injection sleeve, a sliding sound is generated. Even a sliding sound that is not detectable in air can be detected as a high-frequency (ultrasonic range) elastic wave transmitted within the injection sleeve. Furthermore, the inventors of this application discovered that even in cases of wear conditions where there is no significant change in sliding resistance that can be detected as a change in injection pressure, changes reflecting this wear condition appear in the elastic waves transmitted within the injection sleeve during sliding. Based on this insight, the inventors of this application completed the following invention.

[0010] That is, the wear condition measuring device in the first aspect of the present invention is a wear condition measuring device for measuring the wear condition of the injection sleeve and the plunger head in a die casting machine. The wear condition measuring device includes: a mold holding part that holds a mold having a cavity; a cylindrical injection sleeve that is supplied with molten metal; a plunger head that is slidably disposed in the injection sleeve to inject the molten metal supplied to the injection sleeve into the cavity; and an injection driving part that causes the plunger head to move back and forth in the injection sleeve. The wear condition measuring device includes: an elastic wave measuring part that measures the elastic wave transmitted in the injection sleeve when the plunger head moves; and a determination part that determines the wear condition of at least one of the injection sleeve and the plunger head based on the output signal of the elastic wave measuring part. The elastic wave measuring part includes a transmission member having one end in contact with the injection sleeve and another end away from the injection sleeve. Furthermore, in this invention, "wear" refers to the following broad concept: it includes not only the thinning of the sliding surfaces of the injection sleeve and plunger head, but also the formation of areas where the sliding resistance increases due to scratches (damage) formed on the sliding surfaces.

[0011] In the wear condition measuring device according to the first aspect of the present invention, as described above, an elastic wave measuring unit is provided to measure the elastic waves transmitted in the injection sleeve when the plunger head moves. Therefore, by measuring the high-frequency elastic waves (acoustic emission, AE waves) generated and transmitted in the injection sleeve due to the sliding of the plunger head and the injection sleeve, changes in the elastic waves corresponding to the degree of wear on the sliding surface can be grasped. Since the elastic waves generated by the sliding propagate in the injection sleeve, even minute changes such as sliding sounds transmitted in the air or changes in injection pressure that are not measured can be captured. Furthermore, by providing a determination unit that determines the wear condition of at least one of the injection sleeve and the plunger head based on the output signal of the elastic wave measuring unit, the wear condition (the progression of wear) can be grasped based on the output signal of the elastic wave measuring unit. Thus, the wear of the plunger head and the injection sleeve can be grasped with high precision.

[0012] In the wear condition measuring device according to the first embodiment described above, it is preferable that the elastic wave measuring unit includes an elastic wave detection sensor mounted on the other end of the conveying member to measure the elastic wave transmitted from the injection sleeve via the conveying member. With this configuration, for example, it is possible to measure the elastic wave transmitted to the mold holding part that holds the injection sleeve, rather than measuring the elastic wave transmitted to it, directly from the injection sleeve using the conveying member, which is responsible for measuring the elastic wave generated by the sliding of the plunger head and the injection sleeve. Furthermore, the injection sleeve becomes extremely hot (hundreds of degrees Celsius) due to the supply of molten metal, making it difficult to directly mount even a heat-resistant sensor onto the injection sleeve. Therefore, by transmitting the elastic wave to the conveying member that contacts the injection sleeve, the effect of heat on the elastic wave detection sensor can be suppressed while simultaneously measuring the elastic wave.

[0013] In this case, it is preferable that the wear condition measuring device further includes a sleeve holding part fixed to the mold holding part while holding the injection sleeve, and a holding part for holding the conveying part. The holding part can be installed in the sleeve holding part or the mold holding part in a manner that does not contact the injection sleeve, and is configured to apply force to the injection sleeve at one end of the conveying part. If configured in this way, the contact state between the conveying part and the injection sleeve can be reliably maintained by the force of the holding part. In addition, the holding part can be installed in the sleeve holding part or the mold holding part, which is part of the die casting machine, so there is no need to provide a separate platform or the like for fixing the holding part in a predetermined position. Moreover, since the holding part does not contact the injection sleeve, even when replacing a worn injection sleeve, the holding part can be prevented from obstructing the replacement operation.

[0014] In the wear condition measuring device according to the first embodiment described above, it is preferable that the wear condition measuring device further includes a signal processing unit that calculates an intensity index of the elastic wave per unit time based on the output signal of the elastic wave measuring unit obtained during the movement of the plunger head, and a determination unit configured to determine the degree of wear in at least one of the injection sleeve and the plunger head based on the calculated intensity index. If configured in this way, the degree of wear progression can be accurately determined based on the change in the intensity index per unit time during the movement (sliding) of the plunger head (e.g., based on the appearance of a sharp, peak-like intensity peak or a significant displacement of the baseline).

[0015] In the wear condition measuring device according to the first embodiment described above, it is preferable that the determination unit obtains the position information of the plunger head when it is moved by the injection drive unit, and is configured to infer the wear location of the injection sleeve based on the output signal and position information of the elastic wave measuring unit during the movement of the plunger head. If configured in this way, it is possible to determine where the wear progresses on the injection sleeve. Therefore, useful information can be obtained for studying the adjustment of the assembly angle of the injection sleeve or injection drive unit for suppressing the progress of wear, or for optimizing the injection action control.

[0016] In the wear condition measuring device according to the first embodiment described above, it is preferable that the wear condition measuring device further includes an extraction processing unit for extracting the signal component corresponding to the elastic wave at a frequency within the ultrasonic range from the output signal of the elastic wave measuring unit. Here, the frequency within the ultrasonic range refers to a frequency of 20 kHz or higher. With this configuration, vibrations such as those generated during the injection action (displacement, chatter, etc.) or vibrations transmitted from other parts of the die-casting machine are vibrations at frequencies sufficiently lower than the ultrasonic range. Therefore, such vibration components can be removed, and the signal component resulting from the sliding between the plunger head and the injection sleeve can be extracted. As a result, the signal-to-noise ratio (SN ratio) of the signal components related to the determination of wear condition can be improved.

[0017] In the configuration of the aforementioned retaining member, it is preferable that the retaining member includes: a first bracket mounted on the sleeve retaining portion or the mold retaining portion and retaining the conveying member; and a force-applying member disposed between the first bracket and the conveying member, applying force to the injection sleeve at one end of the conveying member. With this configuration, the conveying member can be stably retained by the first bracket, and the contact state between one end of the conveying member and the injection sleeve can be easily ensured by the force-applying member applying force to the conveying member relative to the first bracket.

[0018] In this case, it is preferable that the force-applying component is a leaf spring disposed between the first bracket and the conveying component in a deformed state, applying force to the injection sleeve at one end of the conveying component, or a compression coil spring disposed between the first bracket and the conveying component in a compressed state, applying force to the injection sleeve at one end of the conveying component. If configured in this way, when the force-applying component is a leaf spring, the first bracket can more stably hold the conveying component via the leaf spring, which has higher rigidity. When the force-applying component is a compression coil spring, compared to the case where a more rigid force-applying component is located between the first bracket and the conveying component, vibration is less likely to be transmitted between the first bracket and the conveying component. Therefore, vibration (noise) transmitted from the sleeve holding section or mold holding section of the die-casting machine on which the first bracket is mounted is less likely to be transmitted to the elastic wave detection sensor mounted on the conveying component.

[0019] In the wear condition measuring device according to the first embodiment described above, it is preferable that the wear condition measuring device further includes a sleeve holding part fixed to the mold holding part while holding the injection sleeve, and an elastic wave measuring part including: a second bracket mounted on the sleeve holding part or the mold holding part, which directly holds the conveying member, such that one end of the conveying member abuts against the injection sleeve; and an elastic wave detection sensor mounted on the second bracket, which measures the elastic wave transmitted from the injection sleeve via the conveying member. With this configuration, the conveying member can be directly held by the second bracket, and the second bracket can have multiple functions, such as the function of being mounted on the sleeve holding part or the mold holding part, the function of mounting the elastic wave detection sensor, and the function of holding the conveying member. Therefore, compared with the case where the conveying member is indirectly held by the second bracket or where multiple components separately have the above-mentioned functions, the device configuration of the wear condition measuring device can be simplified.

[0020] In this case, it is preferable that the second bracket is formed such that the thickness of the portion holding the conveying member on one side is smaller than the thickness of the portion where the elastic wave detection sensor is mounted. If configured in this way, the thickness of the portion from the conveying member to the side of the conveying member holding the second bracket can be relatively thin, thus allowing the thin portion of the second bracket to vibrate more significantly using the elastic wave transmitted from the conveying member to the second bracket, thereby improving the detection accuracy of the elastic wave by the elastic wave detection sensor.

[0021] The die-casting machine of the second aspect of the present invention comprises: a mold holding section that holds a mold having a cavity; a cylindrical injection sleeve to which molten metal is supplied; a plunger head that is slidably disposed within the injection sleeve to inject the molten metal supplied to the injection sleeve into the cavity; an injection driving section that causes the plunger head to move forward and backward within the injection sleeve; an elastic wave measuring section that measures the elastic wave transmitted in the injection sleeve when the plunger head moves; and a determination section that determines the wear condition of at least one of the injection sleeve and the plunger head based on the output signal of the elastic wave measuring section, the elastic wave measuring section including a conveying member having one end in contact with the injection sleeve and another end away from the injection sleeve.

[0022] In the die-casting machine according to the second aspect of the present invention, similar to the first aspect described above, an elastic wave measuring unit is provided to measure the elastic waves transmitted in the injection sleeve when the plunger head moves. Therefore, by measuring the high-frequency elastic waves (acoustic emission, AE waves) generated due to the sliding of the plunger head and the injection sleeve and transmitted in the injection sleeve, the change in elastic waves corresponding to the degree of wear on the sliding surface can be grasped. Furthermore, by providing a determination unit that determines the wear condition of at least one of the injection sleeve and the plunger head based on the output signal of the elastic wave measuring unit, the wear condition (the progression of wear) can be grasped based on the output signal of the elastic wave measuring unit. Thus, the wear of the plunger head and the injection sleeve can be grasped with high precision.

[0023] Invention Effects According to the present invention, as described above, the wear of the plunger head and the injection sleeve can be controlled with high precision. Attached Figure Description

[0024] Figure 1 This is a schematic diagram showing the overall structure of a die-casting machine equipped with a wear condition measuring unit.

[0025] Figure 2 This is a block diagram illustrating the wear condition measuring unit and the control device of the die-casting machine.

[0026] Figure 3 It is a schematic diagram used to illustrate the movement control of the plunger head in the injection process of a die-casting machine.

[0027] Figure 4 It is a schematic diagram used to illustrate the wear generated in sliding parts and the elastic waves generated along with the sliding of the sliding parts.

[0028] Figure 5 This is a schematic enlarged top view showing the structure of the elastic wave measuring unit of the first embodiment near the injection sleeve.

[0029] Figure 6 This is a schematic diagram illustrating the shape of one end of the delivery component that contacts the injection sleeve.

[0030] Figure 7 This is a schematic diagram showing the output signal of the AE sensor after frequency filtering.

[0031] Figure 8 It is a schematic diagram showing the intensity index data generated based on the output signal of the AE sensor.

[0032] Figure 9 The charts are generated based on strength index data and plunger head position information. (A) is a chart showing the progress of wear on sliding parts, and (B) is a schematic diagram of the chart when it is normal.

[0033] Figure 10 This is a flowchart used to illustrate the measurement and processing of wear conditions of sliding parts.

[0034] Figure 11 This is a schematic enlarged top view showing the structure of the elastic wave measuring unit of the second embodiment near the injection sleeve.

[0035] Figure 12 This is a schematic enlarged top view showing the structure of the elastic wave measuring unit of the third embodiment near the injection sleeve.

[0036] Figure 13 This is a schematic diagram illustrating an example of the configuration of a wear condition measuring device independent of the die-casting machine.

[0037] Figure 14 These are schematic diagrams showing variations (A) and (B) of the shape of one end of the conveying component. Detailed Implementation

[0038] Hereinafter, embodiments embodying the present invention will be described with reference to the accompanying drawings.

[0039] (First Embodiment) Reference Figures 1 to 9 The configuration of the die-casting machine 1 equipped with the wear condition measuring unit 8 according to the first embodiment will be described. The wear condition measuring unit 8 is an example of the "wear condition measuring device" claimed in the claims. Furthermore, in the drawings, the Z direction is defined as the up-down direction, the Z1 direction of the Z direction is defined as upward, and the Z2 direction of the Z direction is defined as downward. In addition, the X direction and the Y direction are defined as two directions orthogonal to each other in the horizontal plane, the X1 direction of the X direction is defined as the forward direction of the plunger head 6a described later, and the X2 direction of the X direction is defined as the backward direction of the plunger head 6a.

[0040] (Composition of a die-casting machine) like Figure 1As shown, the die-casting machine 1 is a horizontal machine in which the movable mold 2a moves in the horizontal direction. In addition, the die-casting machine 1 is a cold chamber type machine, which is configured to manufacture die-cast products (molten products) by injecting molten metal material as liquid into the mold 2 installed in the die-casting machine 1 (cavity C formed by the movable mold 2a and the fixed mold 2b).

[0041] The die-casting machine 1 includes a mold holding section 3, an injection section 4, a sleeve holding section 40, and a wear condition measuring section 8. Additionally, Figure 1 The die-casting machine 1 includes a melt supply device 9, a cover mechanism 10, a mold closing part 11, a control device 12, a display part 13, and a notification device 14.

[0042] The mold holding part 3 holds the mold 2 having cavity C. The mold holding part 3 includes a fixed pressure plate 3a and a movable pressure plate 3b.

[0043] Mold 2 includes a movable mold 2a and a fixed mold 2b. The fixed mold 2b is fixed to a fixed pressure plate 3a. The movable mold 2a is mounted on the movable pressure plate 3b, which can move in a direction (X direction) that abuts against or moves away from the fixed mold 2b. Cavity C is formed by abutting the movable mold 2a against the fixed mold 2b. Cavity C is a hollow portion used to form a die-cast product (molded product).

[0044] The movable pressure plate 3b moves along the X direction via the mold closing part 11. The mold closing part 11 includes a drive unit 11a that drives the movable pressure plate 3b. The drive unit 11a is, for example, an electric motor, which drives the movable pressure plate 3b along the X direction via a transmission mechanism 11b such as a ball screw shaft. The drive unit 11a is not limited to an electric type; it can also be a hydraulic drive unit that drives a transmission mechanism composed of a toggle mechanism, or a hybrid drive unit that combines electric and hydraulic types.

[0045] The injection unit 4 includes an injection sleeve 5, a plunger 6, and an injection drive unit 7.

[0046] The injection sleeve 5 has a cylindrical shape with openings at both ends. The injection sleeve 5 extends linearly along the X direction. The injection sleeve 5 is fixed to the mold holding part 3 via a sleeve holding part 40. The sleeve holding part 40 has a cylindrical shape and holds the injection sleeve 5 by inserting a through-hole portion of it. The sleeve holding part 40 is fixed to the mold holding part 3 while holding the injection sleeve 5. The injection sleeve 5 is configured to allow the injection of molten metal. The injection sleeve 5 is configured to accommodate a plunger head 6a in a slidable manner within the injection sleeve 5. Sliding refers to relative movement in a contact state.

[0047] Specifically, the injection sleeve 5 includes a molten metal injection port 5a and a molten metal passage 5b. The molten metal injection port 5a is provided for injecting molten metal into the molten metal passage 5b via the molten metal supply device 9. The molten metal injection port 5a extends through the upper side (Z1 direction side) of the injection sleeve 5 in the Z direction. The molten metal passage 5b is a through hole extending through the injection sleeve 5 in the X direction. The end of the molten metal passage 5b communicates with the cavity C in the X1 direction.

[0048] The plunger 6 includes a plunger head 6a and a plunger rod 6b. The plunger head 6a is slidably disposed within the injection sleeve 5. The plunger head 6a is mounted on one end (the end on the X1 direction side) of the plunger rod 6b. The plunger rod 6b has a cylindrical shape extending along the X direction. The other end (the end on the X2 direction side) of the plunger rod 6b is mounted on the piston rod of the injection drive unit 7 (hydraulic cylinder 7a). The plunger head 6a is configured such that the molten liquid supplied to the injection sleeve 5 is injected into the cavity C by moving back and forth within the injection sleeve 5 via the injection drive unit 7 through the plunger rod 6b.

[0049] The injection drive unit 7 is configured to move the plunger head 6a forward and backward within the injection sleeve 5. The injection drive unit 7 includes a hydraulic cylinder (hydraulic cylinder) 7a actuated by hydraulic pressure (oil pressure) and a hydraulic circuit 7b. The hydraulic cylinder 7a is connected to the hydraulic circuit 7b and is configured to actuate via the hydraulic circuit 7b. The position (X-direction position) of the plunger head 6a, moved by the hydraulic cylinder 7a, is detected by a position sensor 7c.

[0050] The position sensor 7c is configured to monitor the position of the plunger head 6a (the stroke of the hydraulic cylinder 7a). The position sensor 7c is, for example, a stroke sensor, a magnetic or optical linear encoder, or a laser length measuring instrument.

[0051] The molten metal supply device 9 is configured to draw molten metal as a liquid from a holding furnace (not shown) and supply (inject) the molten metal into the injection sleeve 5. Specifically, the molten metal supply device 9 includes a ladle 9a and an arm 9b. The ladle 9a is a container for drawing molten metal as a liquid from the holding furnace. The arm 9b is configured to move the ladle 9a to the molten metal inlet 5a of the injection sleeve 5 and tilt the ladle 9a to inject the molten metal into the injection sleeve 5.

[0052] The capping mechanism 10 is configured to block the molten inlet 5a after molten metal is injected into the injection sleeve 5 via the molten metal supply device 9. Specifically, the capping mechanism 10 includes a cap portion 10a and an arm 10b. The cap portion 10a has a shape that follows the shape of the molten inlet 5a when viewed from the Z1 direction. The cap portion 10a is disposed at the front end of the arm 10b. The arm 10b is configured to move the cap portion 10a to the molten inlet 5a.

[0053] The wear condition measuring unit 8 includes an elastic wave measuring unit 8a and a determination unit 8b.

[0054] The elastic wave measuring unit 8a is configured to measure the elastic wave EW (refer to) transmitted in the injection sleeve 5 when the plunger head 6a moves. Figure 4 ) to perform measurements.

[0055] The determination unit 8b is configured to determine the wear condition of at least one of the injection sleeve 5 and the plunger head 6a based on the output signal of the elastic wave measuring unit 8a. Hereinafter, the injection sleeve 5 and the plunger head 6a will be collectively referred to as sliding parts SP (see reference 8a). Figure 3 ).

[0056] The control device 12 is configured to control the drives of various parts of the die-casting machine 1. The control device 12 is electrically connected to various parts of the die-casting machine 1. For example... Figure 2 As shown, the control device 12 includes a control unit 12a and a storage unit 12b. The control unit 12a is, for example, a computer comprising a processor such as a CPU (Central Processing Unit) and memory such as ROM (Read Only Memory) and RAM (Random Access Memory). The storage unit 12b includes a non-volatile recording medium such as flash memory. Additionally, the control device 12 includes a display unit 13.

[0057] Storage unit 12b stores programs for execution by control unit 12a (processor). Storage unit 12b is configured to store measurement data (intensity index - position change data 22d described later) from elastic wave measuring unit 8a. In addition, storage unit 12b pre-stores setting information such as a judgment threshold for determining the wear condition of sliding part SP based on the measurement data from elastic wave measuring unit 8a.

[0058] The display unit 13 includes a display medium such as a liquid crystal monitor, configured to display various information related to the die-casting machine 1. The notification device 14 is, for example, an indicator light. The indicator light includes a light-emitting part such as a lamp, configured to notify the user by lighting up or flashing. Additionally, the notification device 14 includes a speaker that outputs a buzzer sound.

[0059] (Summary of the injection procedure) Next, refer to Figure 3 and Figure 1 The operation of the injection process using the die-casting machine 1 will be explained in general. The injection process is performed by controlling each part of the die-casting machine 1 via the control unit 12a.

[0060] First, the control unit 12a controls the molten metal supply device 9 to supply molten metal from... Figure 1The melt injection port 5a of the injection sleeve 5 shown is used to inject the melt into the injection sleeve 5. After the melt is injected, the control cap mechanism 10 blocks the melt injection port 5a.

[0061] After the melt injection port 5a is blocked, the control unit 12a controls the injection drive unit 7 to perform the injection process. For example... Figure 3 As shown, the injection process is roughly divided into several parts, including: Figure 3 (A) Injection pre-procedure and Figure 3 (B) Injection return process. Figure 3 The horizontal axis of graphs (A) and (B) shows the X-direction position of the plunger head 6a corresponding to the schematic diagram inside the injection sleeve 5 shown in the upper part of the figure. The vertical axis of the graph represents the moving speed of the plunger head 6a. The positive direction of the vertical axis (the upper part of the figure) represents the speed in the X1 direction (forward direction), and the negative direction (the lower part of the figure) represents the speed in the X2 direction (reverse direction).

[0062] Figure 3 (A) The injection advance process is the process of advancing the plunger head 6a in the X1 direction within the injection sleeve 5 and injecting the molten liquid into the mold 2. Additionally, Figure 3 (B) The injection return process is as follows: the plunger head 6a, which has advanced in the injection advance process, is reversed in the X2 direction within the injection sleeve 5, so that the plunger head 6a is moved to the standby position for the next melt injection.

[0063] Figure 3 (A) The injection advance process includes a low-speed advance process and a high-speed advance process. The control unit 12a controls the injection drive unit 7 to switch between a low-speed injection process in which the plunger head 6a moves at a low speed and a high-speed injection process in which the plunger head 6a moves at a high speed. The low-speed injection process is a process in which the plunger head 6a moves at a target speed of a first speed V1. In addition, the high-speed injection process is a process in which the plunger head 6a moves at a target speed of a second speed V2, which is a speed greater than the first speed V1. The position for switching from the low-speed advance process to the high-speed advance process (high-speed switching position Cp) is the position where the plunger head 6a blocks the injection sleeve 5 so that the pressure inside the injection sleeve 5 does not escape from the melt injection port 5a. Specifically, the high-speed switching position Cp is set at a position where the surface of the plunger head 6a on the X1 direction side reaches a position further on the X1 direction side than the end of the melt injection port 5a on the X1 direction side. Furthermore, the low-speed advance process is performed to improve the filling rate of the melt inside the injection sleeve 5. In addition, the high-speed forward movement is performed to ensure that the molten liquid is distributed throughout the mold 2 (cavity C). After the high-speed forward movement, and after a holding process in which the pressure in cavity C is maintained to solidify the molten liquid, the mold is opened (separation of the moving mold 2a and the fixed mold 2b) and the molded product is discharged from the mold 2.

[0064] Subsequently, the control unit 12a controls the injection drive unit 7 to perform an injection return process. The injection return process is a process in which the plunger head 6a is moved to the standby position in the X2 direction with the third speed V3 as the target speed. One injection process includes one injection advance process and one injection return process. Furthermore, one injection process is also referred to as "one injection". The control unit 12a is based on the position sensor 7c (see reference...) Figure 2 The position information PI of the plunger head 6a obtained (refer to) Figure 2 The position and speed of the plunger head 6a in the injection process (the action of the injection drive unit 7) are controlled.

[0065] (Composition of the wear condition measuring unit) Next, the details of the wear condition measuring unit 8 will be explained.

[0066] <Explanation of the elastic waves generated by sliding> like Figure 4 As shown, the plunger head 6a is configured within the injection sleeve 5 with the following fitting dimensions: it can slide without being in close contact with the inner surface of the injection sleeve 5, and can eject the molten liquid M without leakage of injection pressure. During each injection operation, the plunger head 6a and the injection sleeve 5 come into contact (slide), and their sliding surfaces (the outer surface of the plunger head 6a and the inner surface of the injection sleeve 5) wear down. If the gap CL between the sliding surfaces increases due to wear, a situation like... Figure 4 Such pressure leakage from the gap CL is called backflow. Furthermore, the molten aluminum (e.g., aluminum die-casting) reaches a high temperature of around 700°C, causing deformation of the injection sleeve and plunger head 6a in contact with the molten aluminum (e.g., M). Due to this deformation, if the plunger head 6a contacts the injection sleeve 5 impactfully during injection, scratches DG appear on the sliding surface, causing "jamming". These wears (increased gap CL or formation of scratches DG) occurring in the sliding parts SP gradually progress (expand) due to repeated injection processes.

[0067] If the plunger head 6a slides within the injection sleeve 5, sound waves corresponding to the sliding resistance are generated. These generated sound waves are transmitted within the injection sleeve 5 as elastic waves EW. Such elastic waves EW are called acoustic emissions (AE waves) and belong to the ultrasonic frequency band in the range of tens of kHz to several MHz. The elastic waves EW are generated due to the sliding between the plunger head 6a and the injection sleeve 5, and thus reflect the wear condition of the sliding parts SP (plunger head 6a and injection sleeve 5). The wear condition measurement unit 8 of the first embodiment measures the wear condition of these sliding parts SP (plunger head 6a and injection sleeve 5) by measuring the elastic waves EW transmitted within the injection sleeve 5.

[0068] <Elastic Wave Measurement Department> like Figure 5As shown, the elastic wave measuring unit 8a includes a transmission component 21 and an acoustic emission sensor (hereinafter referred to as AE sensor 22). The acoustic emission sensor (AE sensor) 22 is an example of the "elastic wave detection sensor" of the claims.

[0069] The conveying component 21 is a rod-shaped (thin plate-shaped) component that, in a state where it can move relative to the injection sleeve 5, contacts the injection sleeve 5, causing an elastic wave EW (refer to...) Figure 4 The elastic wave EW transmitted within the injection sleeve 5 is transferred from the injection sleeve 5 to the transfer member 21. The transfer member 21 has one end 21a that contacts the injection sleeve 5 and another end 21b that exits from the injection sleeve 5. The elastic wave EW transmitted within the injection sleeve 5 is transferred from one end 21a to the transfer member 21 and then to the other end 21b. The transfer member 21 is made of the same ferrous material as the injection sleeve 5. The injection sleeve 5 is formed of steel (iron) such as tool steel, and the transfer member 21 is also formed of steel (iron) in the same way as the injection sleeve 5. As a result, the transmission characteristics of the elastic wave EW in the transfer member 21 can be made close to the transmission characteristics of the injection sleeve 5.

[0070] The shape of the end face of one end 21a of the conveying component 21 (the shape of the contact surface with the injection sleeve 5) is not particularly limited, but for example, Figure 6 As shown, one end 21a of the conveying member 21 has a concave shape that curves along the outer peripheral surface of the injection sleeve 5. This allows the injection sleeve 5 to fit tightly against the boundary surface of one end 21a of the conveying member 21, thereby reducing the loss of elastic wave EW at the boundary surface. Figure 5 In the example shown, the conveying component 21 is bent between one end 21a and the other end 21b so as not to interfere with the construction near the injection sleeve 5 of the die-casting machine 1, but the conveying component 21 may also extend in a straight line.

[0071] The AE sensor 22 is mounted on the other end 21b of the conveying component 21. Figure 5 In this configuration, the AE sensor 22 is mounted at the other end 21b of the conveying member 21, positioned a distance D1 from the injection sleeve 5. The AE sensor 22 detects the elastic wave EW (refer to...) transmitted from the injection sleeve 5 via the conveying member 21. Figure 4The AE sensor 22 has a piezoelectric element such as PZT (lead zirconate titanate) and outputs a signal corresponding to the pressure change (strain) acting on the piezoelectric element caused by the elastic wave EW transmitted to the AE sensor 22. Furthermore, while accelerometers exist as sensors with piezoelectric elements, they employ a weight on the piezoelectric element and output a signal corresponding to the displacement of the weight. In contrast, the AE sensor differs in that it does not have a weight and detects pressure changes directly acting on the piezoelectric element. Due to the difference in resonant frequency caused by the presence or absence of a weight, accelerometers are sensitive in a frequency band ranging from several Hz to tens of kHz, while the AE sensor 22 is sensitive in a frequency band ranging from tens of kHz to 1 MHz.

[0072] exist Figure 5 In the example, the wear condition measuring unit 8 (elastic wave measuring unit 8a) includes a holding member 23 that holds the conveying member 21. The holding member 23 can be mounted on the sleeve holding unit 40 in a manner that does not contact the injection sleeve 5, and is configured such that force is applied to the injection sleeve 5 at one end 21a of the conveying member 21. One end 21a of the conveying member 21 is mounted on the holding member 23 in a state that allows it to move relative to the injection sleeve 5.

[0073] Specifically, the retaining member 23 includes a bracket 24 mounted on the sleeve retaining portion 40, a force-applying member 25, and an adjusting member 26. The bracket 24 is an example of the "first bracket" in the claims. The bracket 24 has an L-shape, and one end of the bracket 24 is fixed to the sleeve retaining portion 40 by a bolt 27. The bracket 24 is mounted on the sleeve retaining portion 40 and retains the conveying member 21. Specifically, the bracket 24 is fixed in the sleeve retaining portion 40 to the edge of the sleeve insertion port 40c on which the injection sleeve 5 is mounted, in a manner that does not contact the injection sleeve 5. Figure 5 In the middle, the bracket 24 is mounted on the sleeve holding part 40. When the injection sleeve 5 is mounted on the fixed pressure plate 3a via the intermediate plate (not shown), the bracket 24 can also be mounted on the intermediate plate. The other end of the bracket 24 extends substantially parallel to the injection sleeve 5.

[0074] The force-applying component 25 is located at the other end of the L-shaped bracket 24 and between the bracket 24 and the conveying component 21. The force-applying component 25 is mounted on the bracket 24 in a manner that does not contact the injection sleeve 5 via the adjusting component 26. The force-applying component 25 is configured in a deformed state, applying force to the injection sleeve 5 at one end 21a of the conveying component 21, between the bracket 24 and the conveying component 21. The force-applying component 25 is a U-shaped bent leaf spring, with one end of the force-applying component 25 fixed to the bracket 24 and the conveying component 21 fixed to the other end side.

[0075] The adjusting member 26 is a bolt (screw component) that engages with a threaded hole formed at the other end of the bracket 24. The adjusting member 26 extends toward the injection sleeve 5 through both ends of the U-shaped force-applying member 25 and is mounted on the other end of the bracket 24. Therefore, the force-applying member 25 is sandwiched between the bracket 24 and the screw head of the adjusting member 26. The more the adjusting member 26 is rotated, bringing the screw head closer to the bracket 24, the closer the other end of the force-applying member 25 is to the injection sleeve 5. The amount of rotation of the adjusting member 26 adjusts the pressing force that pushes one end 21a of the transmission member 21 mounted on the other end of the force-applying member 25 toward the injection sleeve 5.

[0076] With this configuration, the conveying component 21 is held by the holding component 23 (force-applying component 25) to apply force toward the injection sleeve 5, so as to keep one end 21a in constant contact with the injection sleeve 5.

[0077] exist Figure 5 In the example, the conveying member 21 is positioned in the X direction at a location overlapping with the melt injection port 5a of the injection sleeve 5 (the X-direction position of the conveying member 21 is within the formation range of the melt injection port 5a in the X direction). The conveying member 21 is positioned towards the Y direction such that it contacts the side of the injection sleeve 5 in the horizontal direction (Y direction) from a position relative to the injection sleeve 5 in the horizontal direction (Y direction). Furthermore, in Figure 1 The side view shown does not depict the elastic wave measuring unit 8a, which includes the transmission component 21, in its original state; therefore, in Figure 1 In the middle, for convenience, the elastic wave measuring part 8a is shown on the lower side relative to the injection sleeve 5.

[0078] (Signal processing of the wear condition measurement unit) like Figure 2 As shown, the wear condition measurement unit 8 includes an amplifier unit 8c, a calculation unit 8d, and the aforementioned determination unit 8b. The AE sensor 22 is connected to the determination unit 8b (control unit 12a of the die-casting machine 1) via the amplifier unit 8c and the calculation unit 8d. The output signal 22a output from the AE sensor 22 is a time-varying signal of the output voltage.

[0079] The amplifier unit 8c includes an amplification unit 31, an extraction and processing unit 32, and an AD conversion unit 33. The amplification unit 31 obtains the output signal 22a from the AE sensor 22 and amplifies the obtained output signal 22a at a preset amplification rate.

[0080] The extraction processing unit 32 extracts the signal component corresponding to the elastic wave EW at a frequency within the ultrasonic range from the output signal 22a of the elastic wave measuring unit 8a. That is, the extraction processing unit 32 acquires the output signal (output voltage) amplified in the amplification unit 31, performs frequency filtering on the acquired output signal, and thereby extracts the signal component at a frequency within a predetermined ultrasonic range. The frequency filtering process includes at least a high-pass filtering process to remove frequency components lower than a low-frequency threshold. The frequency filtering process in the first embodiment is a band-pass filtering process (a combination of high-pass and low-pass filtering).

[0081] The extraction processing unit 32 extracts signal components of at least 20 kHz or higher (ultrasonic range) from the output signal 22a, and removes signal components of less than 20 kHz. In the first embodiment, the extraction processing unit 32, for example, extracts signal components with frequencies in the ultrasonic range of 50 kHz or higher but less than 500 kHz (removing signal components of less than 50 kHz and signal components of 500 kHz or higher). Thus, signal components within the frequency band corresponding to the elastic wave EW caused by the sliding of the sliding part SP are retained, while signal components within the frequency band unnecessary for determining the wear condition of the sliding part SP are removed.

[0082] The AD conversion unit 33 performs A / D conversion processing on the output signal (the amplified signal with extracted signal components) that has passed through the amplification unit 31 and the extraction processing unit 32. As a result, the amplifier unit 8c outputs the digitally converted output signal 22b to the arithmetic unit 8d. The output signal 22b is a time-varying signal of the output voltage value (digital value) after frequency filtering processing by the extraction processing unit 32. Figure 7 This is a graph showing the output signal 22b, with the horizontal axis representing time and the vertical axis representing the output voltage value.

[0083] Return to Figure 2 The arithmetic unit 8d is a computer equipped with a processor and memory, and is connected to the amplifier unit 8c and the control unit 12a in a communicable manner. The arithmetic unit 8d obtains the output signal 22b of the AE sensor 22, which has undergone digital conversion, from the amplifier unit 8c as the measurement data of the elastic wave measuring unit 8a.

[0084] The arithmetic unit 8d includes a signal processing unit 34 as a function block for software processing by executing a program stored in memory. The signal processing unit 34 is configured to calculate the intensity index of the elastic wave EW per unit time based on the output signal 22b of the elastic wave measuring unit 8a (AE sensor 22) obtained when the plunger head 6a moves.

[0085] The intensity index of the elastic wave EW can be the maximum amplitude of the output signal per unit time, the energy of the output signal per unit time, or the effective value of the output signal per unit time. In the first embodiment, the signal processing unit 34 processes the output signal 22b based on its time-varying waveform (refer to...). Figure 7 This is used to calculate the energy of the output signal per unit time.

[0086] Specifically, the signal processing unit 34 calculates the area of ​​the time-varying waveform of the output signal (output voltage value) as the energy of the output signal 22b. Therefore, the signal processing unit 34 generates intensity index data 22c based on the time variation of the output signal 22b of the elastic wave measuring unit 8a (AE sensor 22), and outputs the generated intensity index data 22c to the determination unit 8b. The intensity index data 22c is data that converts the output signal of the AE sensor 22 into a time-varying waveform of energy (intensity index). Figure 8 This is a chart showing the intensity index data 22c, with the horizontal axis representing time and the vertical axis representing the intensity index (energy).

[0087] like Figure 2 As shown, in the first embodiment, the determination unit 8b is a function block that performs software processing by executing a program stored in the storage unit 12b through the control unit 12a, and is configured with the same processor as the control unit 12a. In other words, the control unit 12a of the die-casting machine 1 also functions as the determination unit 8b of the wear condition measuring unit 8 by executing the program. The control device 12 may also have separate processors for the control unit 12a and for the determination unit 8b.

[0088] The determination unit 8b determines the wear condition of at least one of the injection sleeve 5 and the plunger head 6a based on the output signal (intensity index data 22c) of the elastic wave measuring unit 8a. Specifically, the determination unit 8b is configured to determine the degree of wear of at least one of the injection sleeve 5 and the plunger head 6a based on the output signal (intensity index data 22c) of the elastic wave measuring unit 8a.

[0089] In the first embodiment, the determination unit 8b acquires position information PI of the plunger head 6a as it moves using the injection drive unit 7. That is, the determination unit 8b acquires the X-axis position of the plunger head 6a during the injection process over time based on the output signal of the position sensor 7c of the injection drive unit 7. The acquired position information PI is time-varying data of the X-axis position of the plunger head 6a.

[0090] Furthermore, the determination unit 8b is configured to infer the wear location of the injection sleeve 5 based on the output signal (intensity index data 22c) of the elastic wave measuring unit 8a during the movement of the plunger head 6a and the position information PI. Specifically, the determination unit 8b generates intensity index-position change data 22d, which shows the change of intensity index at each X-axis position of the plunger head 6a, based on the intensity index data 22c (i.e., the time change of energy value) and the position information PI (the X-axis position of the plunger head 6a at each moment). Figure 9 As shown, the strength index—position change data 22d can be represented as a graph (graphs 41a, 41b) with the horizontal axis set as the X-axis position coordinate of the plunger head 6a and the vertical axis set as the strength index (energy). Furthermore, the determination unit 8b infers the degree of wear at each position of the plunger head 6a based on the strength index—position change data 22d.

[0091] The determination unit 8b acquires strength index-position change data 22d for each injection (one injection process) of the die-casting machine 1. Whenever strength index-position change data 22d is acquired, the wear condition of the sliding part SP is determined. Based on the wear condition of the sliding part SP, the determination unit 8b determines whether to issue a notification. If the wear condition of the sliding part SP meets the notification conditions, the determination unit 8b displays information to the display unit 13 of the control device 12 and issues a notification via the notification device 14. Upon receiving the notification, the operator considers whether to replace the sliding part SP. If it is determined that replacement is necessary, at least one of the injection sleeve 5 and the plunger head 6a can be replaced.

[0092] <An example of a method for determining wear condition> The following is an example of a method for determining the wear condition of the sliding part SP using the determination unit 8b.

[0093] Figure 9 (A) The figure 41a shows the strength index-position change data 22d obtained during the injection advance process when the sliding part SP is worn and needs to be replaced. Figure 9 (B) Chart 41b plots the strength index-position change data 22d obtained during the injection advance process in a normal state, after the sliding part SP has just been replaced and before the wear of the sliding part SP has progressed.

[0094] First, let's use chart 41b under normal conditions to illustrate the overall trend of the strength index—position change data 22d. During the injection advance process, as the plunger head 6a advances from its stationary state in the standby position (right end of charts 41a, 41b), the state changes from static friction to dynamic friction, causing the strength index to temporarily rise in a peak-like manner. Subsequently, during the low-speed advance process, the plunger head 6a moves at a constant low speed, so the strength index remains approximately constant at a low level. When the plunger head 6a reaches the high-speed switching position Cp and switches to the high-speed advance process, the strength index begins to rise along with the change in the plunger head 6a's moving speed. During the high-speed advance process, the pressure inside the injection sleeve 5 sometimes increases as the plunger head 6a advances, and the strength index tends to increase. At the end of the high-speed advance process, the reaction force transmitted from cavity C via the melt M increases sharply, causing the strength index to rise sharply.

[0095] In graph 41a, which shows the wear progression of the sliding part SP, spike-like (spiky) peaks 42 with significantly higher intensity than those in graph 41b are generated at multiple locations in the X direction. This indicates that "jamming" or similar localized wear has occurred at the locations where peaks 42 are generated in the injection sleeve 5. Therefore, by setting the threshold Th1 to a value that is higher than the maximum intensity in graph 41b under normal conditions and that can distinguish the intensity of peaks 42 in graph 41a, localized wear of the injection sleeve 5 can be detected.

[0096] The determination unit 8b determines the wear condition of the injection sleeve 5 (whether local wear occurs and the location of local wear) based on whether there is a peak 42 above the preset threshold Th1 in the strength index-position change data 22d.

[0097] Furthermore, in graph 41a showing the wear progression of the sliding part SP, the baseline 43 of the intensity waveform rises compared to graph 41b. That is, in graph 41a, an elastic wave EW with a higher intensity is generated throughout the entire stroke of the plunger head 6a than in graph 41b. It can be assumed that this increase in the intensity index, independent of the X-direction position of the plunger head 6a, does not indicate wear on the injection sleeve 5, but rather wear on the sliding surface side of the plunger head 6a. Therefore, by setting the threshold Th2 to an intensity index value that can distinguish the intensity of the baseline 43 in graph 41b from that in graph 41a, wear on the plunger head 6a can be detected.

[0098] The determination unit 8b determines the wear condition (whether wear has occurred) of the plunger head 6a based on whether the baseline 43 of the strength index—position change data 22d—is above the preset threshold Th2.

[0099] Furthermore, in one of the examples above, the determination unit 8b determines the wear condition based on the strength index of the injection advance process—position change data 22d. Alternatively, it can also be based on... Figure 3 The wear condition is determined by the strength index—position change data 22d—during the injection return process. In the injection return process, the injection sleeve 5 does not contain molten liquid M (refer to...). Figure 4 This suppresses deformation of the sliding part SP due to the melt temperature, and the reaction force caused by the melt M does not act on the plunger head 6a. Therefore, the waveform of the strength index—position change data 22d—obtained during the injection return process is consistent with... Figure 9 The waveforms shown are different. Therefore, in another example, the determination unit 8b determines the wear condition of the sliding part SP based not only on the strength index—position change data 22d—from the injection advance process, but also on the strength index—position change data 22d from the injection return process. This allows for the detection of wear conditions that cannot be determined solely by the strength index—position change data 22d from the injection advance process, or for improving the accuracy of wear condition monitoring.

[0100] Furthermore, the method for determining the wear condition of the sliding part SP is not limited to the method described above. For example, data on the normal state (Figure 41b) where the wear of the sliding part SP has not progressed can be stored in the storage unit 12b, and the wear condition can be determined by comparing the stored normal data (Figure 41b) with the strength index—position change data 22d obtained for each injection. The wear of the sliding part SP progresses gradually with each injection. Therefore, the obtained strength index—position change data 22d changes from a waveform close to that of Figure 41b in the near-normal state to a waveform of Figure 41a in the gradually progressing wear state as the number of injections increases. Thus, the determination unit 8b can also determine the degree of wear condition by, for example, calculating the difference, deviation (similarity), or correlation function between the waveform of Figure 41b in the normal state and the waveform obtained from the obtained strength index—position change data 22d.

[0101] (Measurement and processing of wear condition of sliding parts) Reference Figure 10 The measurement and processing of the wear condition of the sliding part SP using the determination unit 8b will be explained. The wear condition measurement and processing is performed for each injection of material during the molding operation of the die-casting machine 1. The following process assumes that the molten metal M is injected into the injection sleeve 5, and that the timer starts from the point after the molten metal injection port 5a is blocked by the capping mechanism 10.

[0102] In step S1, the determination unit 8b starts elastic wave measurement simultaneously with the start of the injection process of the die-casting machine 1. That is, if the control unit 12a starts controlling the injection sleeve 5 to execute the injection advance process, the determination unit 8b instructs the arithmetic unit 8d to start collecting the output signal from the AE sensor 22 of the elastic wave measurement unit 8a. The output signal from the AE sensor 22 is processed by the amplifier unit 8c and the arithmetic unit 8d respectively, and is converted into intensity index data 22c (the time change of the intensity index, referencing...). Figure 8 The output is sent to the decision unit 8b in the form of ).

[0103] In die casting machine 1, after the injection advance process is completed and the molded part is removed from mold 2 by mold opening, the injection return process is performed in die casting machine 1. The determination unit 8b also obtains the strength index data 22c from the calculation unit 8d for the injection return process.

[0104] In step S2, the determination unit 8b terminates the elastic wave measurement at the same time as the injection return process of the die-casting machine 1 ends. Furthermore, strictly speaking, the determination unit 8b performs two measurements: the elastic wave measurement during the injection advance process and the elastic wave measurement during the injection return process, or it performs one measurement from the start of the injection advance process to the end of the injection return process.

[0105] In step S3, the determination unit 8b generates strength index-position change data 22d (refer to) based on the measured data of the elastic wave EW (strength index data 22c) and the position information PI of the plunger head 6a obtained by the position sensor 7c. Figure 9 ).

[0106] In step S4, the determination unit 8b determines the wear condition of the sliding part SP based on the strength index—position change data 22d. As described above, the wear condition determination includes determining the wear location of the injection sleeve 5 and the degree of wear at that location (whether it is a peak value 42 above the threshold). In addition, the wear condition determination includes determining whether wear has occurred in the plunger head 6a.

[0107] In step S5, the determination unit 8b determines whether to issue a notification based on the determination result of the wear condition of the sliding part SP. The notification conditions are pre-stored in the storage unit 12b as setting information. For example, the notification conditions may include the detection of a peak value 42 that is above a threshold value of a set number (a predetermined number of 1 or more) or the detection of a baseline 43 whose intensity exceeds the threshold Th2. In addition to measurement data, the notification conditions may also be set by combining other information such as the elapsed time since the last replacement of the sliding part SP or the cumulative number of injections.

[0108] If the determination unit 8b determines in step S5 that the notification conditions are met, the process proceeds to step S6, where notification processing is performed using one or both of the display unit 13 and the notifier 14, and then the determination process ends. If the determination unit 8b determines in step S5 that the notification conditions are not met, no notification processing is performed, and the determination process ends.

[0109] By performing the above steps for each injection process of the die-casting machine 1, the operator is notified of the wear condition when the wear condition of the sliding part SP meets the preset notification conditions.

[0110] (Effects of the first embodiment) The effects of the first embodiment will be explained.

[0111] In the first embodiment, as described above, an elastic wave measuring unit 8a is provided to measure the elastic wave EW transmitted in the injection sleeve 5 when the plunger head 6a moves. Therefore, by measuring the high-frequency elastic wave EW generated and transmitted in the injection sleeve 5 due to the sliding between the plunger head 6a and the injection sleeve 5, changes in the elastic wave EW corresponding to the degree of wear on the sliding surface can be determined. Since the elastic wave EW generated by the sliding propagates in the injection sleeve 5, even minute changes such as sliding sounds transmitted in the air or changes in injection pressure that are not measured can be captured. Furthermore, by providing a determination unit 8b that determines the wear condition of at least one of the injection sleeve 5 and the plunger head 6a based on the output signal of the elastic wave measuring unit 8a, the wear condition (the progression of wear) can be determined based on the output signal of the elastic wave measuring unit 8a. Thus, the wear of the plunger head 6a and the injection sleeve 5 can be determined with high precision.

[0112] Furthermore, in the first embodiment, as described above, the elastic wave measuring unit 8a includes an AE sensor 22, which is mounted on the other end 21b of the conveying member 21 and measures the elastic wave EW transmitted from the injection sleeve 5 via the conveying member 21. Thus, for example, it is possible to measure the elastic wave EW generated by the sliding of the plunger head 6a and the injection sleeve 5 directly from the injection sleeve 5, instead of measuring the elastic wave EW transmitted to the mold holding part 3 that holds the injection sleeve 5, using the conveying member 21. Additionally, the injection sleeve 5 is at a very high temperature (around 700°C in the first embodiment) due to the supply of molten metal M, making it difficult to directly mount even a heat-resistant sensor on the injection sleeve 5. Therefore, by transmitting the elastic wave EW to the conveying member 21 that contacts the injection sleeve 5, the effect of heat on the AE sensor 22 can be suppressed while simultaneously measuring the elastic wave EW.

[0113] Furthermore, in the first embodiment, as described above, the retaining member 23 can be installed in the sleeve holding section without contacting the injection sleeve 5, configured such that force is applied to the injection sleeve 5 at one end 21a of the conveying member 21. Therefore, the contact state between the conveying member 21 and the injection sleeve 5 can be reliably maintained by the retaining member 23. Additionally, since the retaining member 23 can be installed in the sleeve holding section, which is part of the die-casting machine 1, there is no need to separately provide a platform or the like for fixing the retaining member 23 in a predetermined position. Moreover, since the retaining member 23 does not contact the injection sleeve 5, even when replacing a worn injection sleeve 5, the retaining member 23 can be prevented from obstructing the replacement operation.

[0114] Furthermore, in the first embodiment, as described above, a signal processing unit 34 is also included. The signal processing unit 34 calculates an intensity index (intensity index data 22c) of the elastic wave EW per unit time based on the output signal of the elastic wave measuring unit 8a acquired during the movement of the plunger head 6a. The determination unit 8b is configured to determine the degree of wear in at least one of the injection sleeve 5 and the plunger head 6a based on the calculated intensity index. Therefore, the degree of wear progression can be accurately determined based on changes in the intensity index during the movement (sliding) of the plunger head 6a (e.g., based on the appearance of a sharp, pointed peak 42 or a significant displacement of the baseline 43).

[0115] Furthermore, in the first embodiment, as described above, the determination unit 8b is configured to: acquire position information PI of the plunger head 6a when it is moved by the injection drive unit 7, and infer the wear location of the injection sleeve 5 based on the output signal of the elastic wave measuring unit 8a during the movement of the plunger head 6a and the position information PI. Thus, it is possible to determine where the wear progresses on the injection sleeve 5. Therefore, useful information can be obtained for studying the adjustment of the assembly angle of the injection sleeve 5 or the injection drive unit 7 to suppress the progress of wear, or for optimizing the injection action control.

[0116] Furthermore, in the first embodiment, as described above, an extraction processing unit 32 is also included. This extraction processing unit 32 extracts the signal component of the elastic wave EW corresponding to the frequency of the ultrasonic range from the output signal of the elastic wave measuring unit 8a. Therefore, vibrations (displacement, chatter, etc.) generated during the injection action or vibrations transmitted from other parts of the die-casting machine 1 are vibrations with frequencies significantly lower than the ultrasonic range. Thus, by removing such vibration components and extracting the signal component caused by the sliding between the plunger head 6a and the injection sleeve 5, the signal-to-noise ratio (SN ratio) of the signal components related to the determination of wear conditions can be improved.

[0117] Furthermore, in the first embodiment, as described above, the holding member 23 includes: a bracket 24 mounted on the sleeve holding portion 40 and holding the conveying member 21; and a force-applying member 25 disposed between the bracket 24 and the conveying member 21, applying force to the injection sleeve 5 at one end 21a of the conveying member 21. Thus, the conveying member 21 can be stably held by the bracket 24, and the contact state between one end 21a of the conveying member 21 and the injection sleeve 5 can be easily ensured by the force-applying member 25 applying force to the conveying member 21 relative to the bracket 24.

[0118] Furthermore, in the first embodiment, as described above, the force-applying member 25 is a leaf spring disposed between the bracket 24 and the conveying member 21 in a deformed state, applying force to the injection sleeve 5 at one end 21a of the conveying member 21. Therefore, the bracket 24 can more stably hold the conveying member 21 via the leaf spring, which has relatively high rigidity.

[0119] (Second Implementation) Next, refer to Figure 11 The wear condition measuring unit 208 of the second embodiment will be described. In the second embodiment, the following example will be described: Unlike the first embodiment where the AE sensor 22 is mounted on the conveyor 221, the AE sensor 22 is not mounted on the conveyor 221, but on the bracket 224. Furthermore, the same reference numerals are used for the same parts as in the first embodiment, and descriptions are omitted. The bracket 224 is an example of the "second bracket" in the claims. The wear condition measuring unit 208 is an example of the "wear condition measuring device" in the claims.

[0120] Wear condition measuring unit 208 includes elastic wave measuring unit 208a and determination unit 8b (see reference). Figure 2 The elastic wave measuring unit 208a is disposed on one side of the injection sleeve 5 in the Y direction. Alternatively, the elastic wave measuring unit may be disposed directly below the injection sleeve, etc. The determination unit 8b is based on the output signal of the elastic wave measuring unit 208a (intensity index data 22c (reference)). Figure 2 The wear condition of at least one of the injection sleeve 5 and the plunger head 6a is determined.

[0121] The elastic wave measuring unit 208a includes a transmission component 221, an AE sensor 22, a bracket 224, and an adjustment component 226.

[0122] The conveying component 221 is composed of a rod-shaped part. For example, the conveying component 221 is composed of a bolt, and the adjusting component 226 is composed of a nut that is threadedly engaged with the bolt that serves as the conveying component 221. One end 21a of the bolt that serves as the conveying component 221 abuts against the injection sleeve 5, and the bolt is arranged in a direction orthogonal to the outer surface of the cylindrical injection sleeve 5.

[0123] The bracket 224 is configured to be directly mounted on the sleeve retaining part 40 and to directly hold the conveying member 221, such that one end 21a of the conveying member 221 abuts against the injection sleeve 5. The conveying member 221 is configured such that by adjusting the threaded engagement position of the bolt and nut serving as the conveying member 221, force can be applied to the injection sleeve 5 by the conveying member 221 abutting against the injection sleeve 5.

[0124] In detail, the adjusting component 226 abuts against the bracket 224 from the side of the injection sleeve 5, pressing the bracket 224 in a direction away from the injection sleeve 5, causing the bracket 224 to elastically deform. As a result, the bracket 224 uses its restoring force to generate a force on the conveying component 221 toward the injection sleeve 5. By adjusting the threaded engagement position of the adjusting component 226 (nut) relative to the conveying component 221 (bolt), the magnitude of the force exerted on the conveying component 221 can be adjusted.

[0125] The bracket 224 is a plate component bent in an L-shape. The bracket 224 has a straight portion 224a that extends linearly along the long side (X direction) of the injection sleeve 5; and a straight portion 224b that extends linearly along the short side (Y direction) of the injection sleeve 5. An AE sensor 22 is mounted on the straight portion 224a of the bracket 224. In the X direction, the AE sensor 22 is positioned near the straight portion 224b of the straight portion 224a. A bolt 27 is mounted on the straight portion 224b for securing the bracket 224 to the sleeve retaining portion 40.

[0126] The bracket 224 is formed in such a way that the thickness T2 of the portion 224d on one side of the conveying component 221 is smaller than the thickness T1 of the portion 224c on which the AE sensor 22 is mounted (T1>T2).

[0127] That is, the straight portion 224a of the bracket 224 has a thick-walled portion 224c on which the AE sensor 22 is mounted and a thin-walled portion 224d on one side of the conveying member 221. The straight portion 224b of the bracket 224 is formed to have the same thickness as the thick-walled portion 224c on which the AE sensor 22 is mounted.

[0128] For example, the thickness T2 of the thin-walled portion 224d holding one side of the conveying member 221 is less than half the thickness T1 of the thick-walled portion 224c on which the AE sensor 22 is mounted. As a specific example, the thickness T1 is 6 mm and the thickness T2 is 1.2 mm. Therefore, the thin-walled portion 224d holding one side of the conveying member 221 has a shape that is more easily elastically deformable than the thick-walled portion 224c on which the AE sensor 22 is mounted.

[0129] The other configurations of the second embodiment are the same as those of the first embodiment described above.

[0130] (Effects of the second implementation method) The effects of the second embodiment will be explained.

[0131] In the second embodiment, as described above, an elastic wave measuring unit 208a is provided, which measures the elastic wave transmitted in the injection sleeve 5 when the plunger head 6a moves. Therefore, similar to the first embodiment described above, the wear of the plunger head 6a and the injection sleeve 5 can be accurately measured.

[0132] Furthermore, in the second embodiment, as described above, a sleeve holding portion 40 is also included, which is fixed to the mold holding portion 3 while the injection sleeve 5 is held. The elastic wave measuring portion 208a includes: a conveying member 221 having an end 21a that contacts the injection sleeve 5; a bracket 224, which is mounted on the sleeve holding portion 40 and directly holds the conveying member 221, such that one end 21a of the conveying member 221 abuts against the injection sleeve 5; and an AE sensor 22, which is mounted on the bracket 224 and measures the elastic wave transmitted from the injection sleeve 5 via the conveying member 221. Thus, the conveying member 221 can be directly held by the bracket 224, and the bracket 224 can have multiple functions, such as the function of being mounted on the sleeve holding portion 40, the function of mounting the AE sensor 22, and the function of holding the conveying member 221. Therefore, compared with the case where the conveying member is indirectly held by the bracket or where multiple components have the above-mentioned functions separately, the device configuration of the wear condition measuring portion 208 can be simplified.

[0133] Furthermore, in the second embodiment, as described above, the bracket 224 is formed such that the thickness T2 of the portion 224d holding the conveying member 221 on one side is smaller than the thickness T1 of the portion 224c on which the AE sensor 22 is mounted. This makes the thickness T2 of the portion 224d holding the conveying member 221 from the conveying member 221 to the bracket 224 relatively thin, thus allowing the elastic wave transmitted from the conveying member 221 to the bracket 224 to cause the thinner portion 224d of the bracket 224 to vibrate more significantly, thereby improving the detection accuracy of the elastic wave by the AE sensor 22.

[0134] The other effects of the second embodiment are the same as those of the first embodiment described above.

[0135] (Third implementation) Next, refer to Figure 12The wear condition measuring unit 308 of the third embodiment will be described. In the third embodiment, an example will be described as follows: unlike the first embodiment where the force-applying member 25 is composed of a leaf spring, the force-applying member 325 is composed of a compression coil spring. Furthermore, the same reference numerals are used for the same parts as in the first embodiment, and descriptions are omitted. The wear condition measuring unit 308 is an example of the "wear condition measuring device" claimed in the claims.

[0136] Wear condition measuring unit 308 includes elastic wave measuring unit 308a and determination unit 8b (see reference). Figure 2 The elastic wave measuring unit 308a is disposed on one side of the injection sleeve 5 in the Y direction. Alternatively, the elastic wave measuring unit may be disposed directly below the injection sleeve, etc. The determination unit 8b is based on the output signal of the elastic wave measuring unit 308a (intensity index data 22c (refer to...)). Figure 2 The wear condition of at least one of the injection sleeve 5 and the plunger head 6a is determined.

[0137] The elastic wave measuring unit 308a includes a transmission component 21, an AE sensor 22, and a holding component 323.

[0138] The retaining component 323 includes a bracket 24, a force-applying component 325, and an adjusting component 26.

[0139] Both the conveying component 21 and the bracket 24 are L-shaped bent components. The force-applying component 325 is composed of a compression coil spring. The force-applying component 325 is configured between the bracket 24 and the conveying component 21 in a compressed state, applying force to the injection sleeve 5 at one end 21a of the conveying component 21. The force-applying component 325 is mounted to the bracket 24 in a manner that does not contact the injection sleeve 5 by means of adjusting components 26 (bolts and nuts).

[0140] The bracket 24 and the transmission component 21 are configured with a predetermined maximum distance by the adjusting component 26 (bolts and nuts). This is accompanied by the generation of elastic waves EW (see reference). Figure 4 When the force-applying component 325 extends or retracts, the distance between the bracket 24 and the transmission component 21 varies within a range below the maximum value of a predetermined distance away.

[0141] The conveying member 21 has a straight portion 21c that extends linearly along the long side (X direction) of the injection sleeve 5; and a straight portion 21d that includes one end 21a and extends linearly along the short side (Y direction) of the injection sleeve 5. The bracket 24 has a straight portion 24a that extends linearly along the long side (X direction) of the injection sleeve 5; and a straight portion 24b that includes one end 21a and extends linearly along the short side (Y direction) of the injection sleeve 5. The AE sensor 22 is mounted on the straight portion 21c of the conveying member 21. The straight portion 21c of the conveying member 21 and the straight portion 24a of the bracket 24 are arranged parallel to each other. A bolt 27 for fixing the bracket 24 to the sleeve retaining portion 40 is installed on the straight portion 24b.

[0142] In the Y direction, the conveying member 21 is positioned closer to the injection sleeve 5 than the straight portion 24a of the bracket 24. The force-applying member 325 is positioned between the straight portion 21c of the conveying member 21 and the straight portion 24a of the bracket 24, and is configured to extend and retract in the Y direction. In the X direction, the force-applying member 325 is positioned near one end 21a of the straight portion 21c. In the X direction, the AE sensor 22 is positioned near the other end 21b of the straight portion 21c.

[0143] The other configurations of the third embodiment are the same as those of the first embodiment described above.

[0144] (Effects of the third embodiment) The effects of the third embodiment will be explained.

[0145] In the third embodiment, as described above, an elastic wave measuring unit 308a is provided, which measures the elastic wave transmitted in the injection sleeve 5 when the plunger head 6a moves. Therefore, similar to the first embodiment described above, the wear of the plunger head 6a and the injection sleeve 5 can be accurately measured.

[0146] Furthermore, in the third embodiment, as described above, the holding member 323 includes: a bracket 24 mounted on the sleeve holding portion 40 and holding the conveying member 21; and a force-applying member 325 disposed between the bracket 24 and the conveying member 21, applying force to the injection sleeve 5 at one end 21a of the conveying member 21. Thus, the conveying member 21 can be stably held by the bracket 24, and the contact state between one end 21a of the conveying member 21 and the injection sleeve 5 can be easily ensured by the force-applying member 325 applying force to the conveying member 21 relative to the bracket 24.

[0147] Furthermore, in the third embodiment, as described above, the force-applying member 325 is a compressed helical spring disposed between the bracket 24 and the conveying member 21 in a compressed state, applying force to the injection sleeve 5 at one end 21a of the conveying member 21. As a result, compared to the case where the force-applying member with higher rigidity is located between the bracket 24 and the conveying member 21, it is possible to make it difficult for vibrations to be transmitted between the bracket 24 and the conveying member 21. Therefore, it is possible to make it difficult for vibrations (noise) transmitted from the sleeve holding part 40 side of the die-casting machine 1 on which the bracket 24 is mounted to be transmitted to the AE sensor 22 mounted on the conveying member 21.

[0148] The other effects of the third embodiment are the same as those of the first embodiment described above.

[0149] [Variation Example] Furthermore, the embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The scope of the invention is not shown by the description of the embodiments above, but by the claims, and includes all modifications (variations) within the meaning and scope equivalent to the claims.

[0150] For example, in the first to third embodiments described above, an example is shown where the die-casting machine 1 is configured as a horizontal type, but the present invention is not limited thereto. In the present invention, the die-casting mechanism may also be configured as a vertical type.

[0151] Furthermore, in the first to third embodiments described above, an example is shown where the control block of the software executed by the control unit 12a of the die-casting machine 1 constitutes the determination unit 8b (i.e., the control unit 12a and the determination unit 8b are constructed from the same hardware), but the present invention is not limited thereto. In the present invention, the determination unit 8b may also be configured as a separate determination processing device (computer) equipped with a processor that performs determination processing. The determination unit 8b may also be provided in the arithmetic unit 8d.

[0152] Specifically, in the first to third embodiments described above, an example is shown where the wear condition measuring unit 8 is configured as part of the die-casting machine 1 by incorporating the determination unit 8b into the control device 12 of the die-casting machine 1. However, it is also possible to configure a wear condition measuring device independent of the die-casting machine 1 by separating the determination unit 8b from the control device 12 of the die-casting machine 1. For example, Figure 13 The wear condition measuring device 107 shown, by having an elastic wave measuring unit 8a and a determination unit 8b, can be installed as a retrofit measuring device for existing die-casting machines 101 that do not have wear condition determination functions. The determination unit 8b can also output the wear condition to the control device 110 of the die-casting machine 101 or execute a notification corresponding to the wear condition via a notification device (not shown) provided by the wear condition measuring device 107.

[0153] Furthermore, in the first to third embodiments described above, a wear condition measuring unit 8 is shown (see reference 8). Figure 2 Examples of wear condition measuring units 8 include an amplifier unit 8c, an arithmetic unit 8d, and a determination unit 8b, but the present invention is not limited thereto. In the present invention, the wear condition measuring unit 8 may also be configured as a single device including an amplifier unit 8c, an arithmetic unit 8d, and a determination unit 8b. Alternatively, the amplifier unit 8c and the arithmetic unit 8d may be configured as a single unit.

[0154] Furthermore, in the first to third embodiments described above, an example is shown where a signal processing unit 34 (operation unit 8d) is provided to calculate the intensity index of the elastic wave EW, but the present invention is not limited thereto. In the present invention, the signal processing unit 34 (operation unit 8d) may not be provided. The determination unit 8b may also determine the wear condition of the sliding part SP not based on the intensity index of the elastic wave EW, but based on the output signal 22a (output voltage value) of the AE sensor 22, which is the measurement data of the elastic wave EW itself.

[0155] Furthermore, in the first to third embodiments described above, an example is shown that includes an extraction processing unit 32 that extracts the signal component corresponding to the elastic wave EW at a frequency within the ultrasonic range from the output signal 22a of the elastic wave measuring unit 8a (208a, 308a), but the present invention is not limited thereto. In the present invention, the extraction processing unit 32 may not be provided.

[0156] Furthermore, in the first to third embodiments described above, examples are shown where the elastic wave measuring unit 8a (208a, 308a) includes a transmission member 21 and an AE sensor 22, but the present invention is not limited thereto. In the present invention, the transmission member 21 may not be provided in the elastic wave measuring unit 8a. Additionally, in the present invention, the force applied to the transmission member 21 by the holding member 23 to the injection sleeve 5 may not be required. For example, the [missing information - likely referring to a different device or component] may be used instead of [missing information - likely referring to a different device or component]. Figure 4 A conveyor plate of the same shape as the conveyor component 21 shown is provided on the injection sleeve 5 such that it protrudes from the outer peripheral surface of the injection sleeve 5, and the AE sensor 22 is mounted on this conveyor plate. Alternatively, the AE sensor 22 can be mounted on the sleeve holding portion 40 that holds the injection sleeve 5. For example, the AE sensor 22 can also be mounted on the edge of the sleeve insertion port 40c on which the injection sleeve 5 is mounted in the sleeve holding portion 40, and the AE sensor 22 can detect the elastic wave EW transmitted to the portion that holds the injection sleeve 5.

[0157] Furthermore, in the first to third embodiments described above, an example is shown where one end 21a of the conveying member 21 has a concave shape that curves along the outer peripheral surface of the injection sleeve 5; however, the present invention is not limited thereto. One end 21a of the conveying member 21 may also be as follows... Figure 14As shown in (A), it is a plane, or it can be as shown in (A). Figure 14 As shown in (B), it is a convex curved surface.

[0158] Furthermore, in the first to third embodiments described above, an example is shown where the conveying member 21 contacts the side of the injection sleeve 5 in the Y direction, but the present invention is not limited thereto. The contact position of the conveying member 21 in the injection sleeve 5 is arbitrary, and the conveying member 21 may also contact the upper or lower surface of the injection sleeve 5. The contact position in the X direction is also arbitrary, and the conveying member 21 may contact a position other than near the melt injection port 5a.

[0159] Furthermore, in the first to third embodiments described above, examples are shown where only one elastic wave measuring unit 8a (208a, 308a) is provided, but the present invention is not limited thereto. In the present invention, multiple elastic wave measuring units 8a may also be provided.

[0160] Furthermore, in the first to third embodiments described above, an example is shown where the determination unit 8b determines the wear condition of the sliding part SP based on the strength index—position change data 22d—of the entire injection advance process, including both the low-speed and high-speed advance processes. However, the present invention is not limited to this. In the present invention, the wear condition can also be determined based on data from a portion of the injection advance process. Empirically, wear on the injection sleeve 5 is more likely to occur in the area where the plunger head 6a moves during the high-speed advance process than in the area where the plunger head 6a moves during the low-speed advance process. That is, the likelihood of wear exceeding a threshold occurring first is higher in the area where the plunger head 6a moves during the high-speed advance process; therefore, the determination unit 8b can also determine the wear condition solely based on the strength index—position change data 22d—during the high-speed advance process.

[0161] Furthermore, in the first to third embodiments described above, as an example of a method for determining the wear condition using the determination unit 8b, a method for determining the wear condition based on whether the strength index exceeds a threshold or a method for determining the wear condition by comparing it with the normal strength index—position change data 22d (Figure 41b)—that has not generated wear, is shown. However, the present invention is not limited to these methods. In the present invention, for example, the determination unit 8b may also use a learned model created through machine learning to determine the wear condition. Specifically, for each wear condition of the sliding part SP, measurement data from the elastic wave measuring unit 8a (208a, 308a) are experimentally collected, and a learned model that performs machine learning on the processing of the wear condition of the output with respect to the input data is created in advance using the collected dataset of each wear condition as learning data. The determination unit 8b may also use this learned model to determine the mastered wear condition based on the latest measurement data obtained from the elastic wave measuring unit 8a for each injection. The elastic wave EW measurement data obtained by the elastic wave measurement unit 8a is repeatedly acquired thousands of times with the operation of the die-casting machine 1, in units of essentially the same injection process, and is suitable for collection and processing as learning data for machine learning.

[0162] Furthermore, in the first to third embodiments described above, an example is shown where the brackets 24 and 224 are mounted on the sleeve holding portion 40, but the present invention is not limited thereto. In the present invention, the brackets may not be mounted on the sleeve holding portion, but rather on a fixing plate or other configuration such as the mold holding portion.

[0163] Furthermore, in the above embodiments, for ease of explanation, a process-driven flowchart in which the processing actions of the determination unit 8b are processed sequentially according to the processing flow is used for description, but the present invention is not limited thereto. In the present invention, the processing actions of the control unit can also be performed by event-driven (event-followed) processing that is performed on an event-by-event basis. In this case, it can be performed entirely by event-driven processing, or it can be performed by combining event-driven and process-driven processing.

[0164] Explanation of reference numerals in the attached figures 1. Die-casting machine 2. Mold 3. Mold holding part 5. Injection sleeve 6a plunger head 7. Injection Drive Unit 8, 208, 308 Wear Condition Measurement Section (Wear Condition Measurement Device) 8a, 208a, 308a Elastic Wave Meter Measurement Section 8b Judgment Department 21, 221 Conveying Components 21a One end 21b The other end 22 AE sensor (elastic wave detection sensor) 22a, 22b output signals 22c strength index data 22d Intensity Index—Location Change Data 23, 323 Retaining components 24 Brackets (Bracket 1) 25, 325 Force-applying components 32 Extraction and Processing Unit 34 Signal Processing Department 40 Sleeve Retaining Part 107 Wear Condition Measuring Device 224 Bracket (Second Bracket) Part 224c (with AE sensor installed) 224d (the part that holds the conveyor component on one side) C cavity EW elastic wave M Melt PI location information T1 (thickness of the part with the AE sensor installed) T2 (the thickness of the portion that holds the conveyor component on one side).

Claims

1. A wear condition measuring device for measuring the wear condition of an injection sleeve and a plunger head in a die-casting machine, the die-casting machine comprising: a mold holding section for holding a mold having a cavity; a cylindrical injection sleeve supplied with molten metal; a plunger head slidably disposed within the injection sleeve for injecting the molten metal supplied to the injection sleeve into the cavity; and an injection driving section for moving the plunger head back and forth within the injection sleeve. The wear condition measuring device includes: An elastic wave measuring unit measures the elastic wave transmitted through the injection sleeve as the plunger head moves; and The determination unit determines the wear condition of at least one of the injection sleeve and the plunger head based on the output signal of the elastic wave measuring unit. The elastic wave measuring unit includes a transmission component having one end in contact with the injection sleeve and another end away from the injection sleeve.

2. The wear condition measuring device according to claim 1, wherein, The elastic wave measuring unit includes an elastic wave detection sensor, which is mounted on the other end of the transmission component to measure the elastic wave transmitted from the injection sleeve via the transmission component.

3. The wear condition measuring device according to claim 2, The wear condition measuring device also includes: A sleeve retaining portion, which is fixed to the mold retaining portion while holding the injection sleeve; and A holding component that holds the conveying component. The retaining member can be installed on the sleeve retaining part or the mold retaining part in a manner that does not contact the injection sleeve, and is configured to apply force to the injection sleeve at one end of the conveying member.

4. The wear condition measuring device according to claim 1, The wear condition measuring device further includes a signal processing unit that calculates an elastic wave intensity index per unit time based on the output signal of the elastic wave measuring unit obtained when the plunger head moves. The determination unit is configured to determine the degree of wear in at least one of the injection sleeve and the plunger head based on the calculated strength index.

5. The wear condition measuring device according to any one of claims 1 to 3, wherein, The determination unit: Obtain the position information of the plunger head when it is moved using the injection drive unit. The location of wear on the injection sleeve is inferred based on the output signal of the elastic wave measuring unit during the movement of the plunger head and the position information.

6. The wear condition measuring device according to any one of claims 1 to 3, The wear condition measuring device also includes an extraction processing unit that extracts the signal component corresponding to the elastic wave frequency in the ultrasonic range from the output signal of the elastic wave measuring unit.

7. The wear condition measuring device according to claim 3, wherein, The retaining component includes: The first bracket, which is mounted on the sleeve retaining part or the mold retaining part, and holds the conveying component; and A force-applying component is disposed between the first bracket and the conveying component, and applies force to the injection sleeve at one end of the conveying component.

8. The wear condition measuring device according to claim 7, wherein, The force-applying component is either a leaf spring configured in a deformed state, applying force to the injection sleeve at one end of the conveying component, between the first bracket and the conveying component, or a compression coil spring configured in a compressed state, applying force to the injection sleeve at one end of the conveying component, between the first bracket and the conveying component.

9. The wear condition measuring device according to claim 1, The wear condition measuring device also includes a sleeve holding part that is fixed to the mold holding part while holding the injection sleeve. The elastic wave measuring unit includes: A second bracket, mounted on the sleeve retaining portion or the mold retaining portion, directly holds the conveying component such that one end of the conveying component abuts against the injection sleeve; and An elastic wave detection sensor, mounted on the second bracket, measures the elastic wave transmitted from the injection sleeve via the transmission component.

10. The wear condition measuring device according to claim 9, wherein, The second bracket is formed in such a way that the thickness of one side of the transmission component is smaller than the thickness of the portion on which the elastic wave detection sensor is mounted.

11. A die-casting machine, comprising: A mold holding part that holds a mold having a cavity; A cylindrical injection sleeve is used to supply molten liquid; A plunger head, which is slidably disposed within the injection sleeve, injects the molten liquid supplied to the injection sleeve into the cavity; An injection drive unit that causes the plunger head to move forward and backward within the injection sleeve; An elastic wave measuring unit measures the elastic wave transmitted through the injection sleeve as the plunger head moves; and The determination unit determines the wear condition of at least one of the injection sleeve and the plunger head based on the output signal of the elastic wave measuring unit. The elastic wave measuring unit includes a transmission component having one end in contact with the injection sleeve and another end away from the injection sleeve.

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