JP2023157005A - Abrasion condition measuring device and die casting machine - Google Patents

Abstract

To provide an abrasion condition measuring device capable of accurately obtaining abrasion of a plunger tip and an injection sleeve.SOLUTION: An abrasion condition measuring part 8 ( abrasion condition measuring device) measures the abrasion condition of an injection sleeve 5 and a plunger tip 6a in a die-casting machine 1 including: a die holding part 3 for holding a die 2; the cylindrical injection sleeve 5 into which molten metal M is supplied; the plunger tip 6a slidably arranged in the injection sleeve 5, the plunger tip injecting the molten metal M supplied to the injection sleeve 5 into the cavity C; and an injection drive part 7 for advancing and retracting the plunger tip 6a within the injection sleeve 5. The abrasion condition measuring part 8 has: an elastic wave measuring part 8a for measuring an elastic wave EW that propagates through the injection sleeve 5 when the plunger tip 6a moves; and a determining part 8b for determining the abrasion condition in at least one of the injection sleeve 5 and the plunger tip 6a based on an output signal of the elastic wave measuring part 8a.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wear condition measuring device and a die casting machine, and more particularly to a wear condition measuring device and a die casting machine equipped with the wear condition measuring device in a die casting machine that injects molten metal in an injection sleeve into a mold using a plunger tip.

2. Description of the Related Art Conventionally, a die casting machine is known in which molten metal in an injection sleeve is injected into a mold using a plunger tip (for example, see Patent Document 1).

Patent Document 1 discloses a die casting machine that supplies molten metal into an injection sleeve and injects the molten metal into a mold cavity by moving a plunger tip slidably provided in the injection sleeve forward at low and high speeds using a cylinder. is disclosed.

Patent Document 1 discloses that when molten metal is repeatedly injected, the plunger tip wears out and solidified metal particles are present in the injection sleeve, resulting in so-called galling, which causes the injection speed to change in a undulating manner. It is stated that this occurs. Therefore, in Patent Document 1, a plurality of evaluation sections are set within the movement range of the plunger tip, the average casting pressure value and the maximum casting pressure value for each evaluation section are calculated, and these values and the preset value are calculated. It is disclosed that the degree of galling is evaluated by assigning a score to each evaluation section by comparing the distance between the two.

Japanese Patent Application Publication No. 2017-104871

The occurrence of "galling" described in Patent Document 1 is mainly caused by wear occurring on one or both of the sliding surfaces of the outer circumferential surface of the plunger tip and the inner circumferential surface of the injection sleeve. In addition to galling, when the gap between the plunger tip and the injection sleeve becomes large due to wear of the sliding surface, a phenomenon called backflush occurs in which pressure is released from the gap. Abnormalities in sliding parts, such as galling or backflushing, can cause a decline in product quality, so worn plunger tips and injection sleeves are replaced. It is desirable to accurately detect wear on plunger tips and injection sleeves so that it is possible to determine whether or not sliding parts need to be replaced at an appropriate time, before wear progresses to the point where product quality is affected. .

However, the evaluation method disclosed in Patent Document 1 indirectly detects the change in sliding resistance due to galling by measuring it as a change in injection pressure. It is difficult to detect slight changes. In other words, when a change in injection pressure due to galling is actually detected, there is a high possibility that a product of degraded quality or a defective product that does not meet the quality standards has been produced.

This invention was made to solve the above-mentioned problems, and one object of the invention is to provide a wear condition measuring device and a wear condition measuring device capable of grasping wear of a plunger tip and an injection sleeve with high precision. Our goal is to provide die casting machines.

In order to achieve the above object, the inventors of the present invention have conducted intensive studies and found that when the plunger tip slides inside the injection sleeve, a sliding sound is generated, which cannot be detected in the air. It has been found that even when the injection sleeve is injected, it can be detected as a high frequency (ultrasonic range) elastic wave propagating within the injection sleeve. The inventors of the present application have also discovered that even if the wear condition is at a stage that does not cause a change in sliding resistance large enough to be detected as a change in injection pressure, the elastic waves that propagate through the injection sleeve during sliding are affected by the We found that changes that reflected the wear status appeared. Based on this knowledge, the inventors of the present application have come up with the following invention.

That is, the wear condition measuring device according to the first aspect of the present invention includes: a mold holding part that holds a mold having a cavity; a cylindrical injection sleeve into which molten metal is supplied; The wear status of the injection sleeve and plunger tip in a die casting machine equipped with a plunger tip that injects the molten metal arranged and supplied to the injection sleeve into a cavity, and an injection drive unit that moves the plunger tip forward and backward within the injection sleeve. The wear condition measurement device includes an elastic wave measurement unit that measures elastic waves propagating through the injection sleeve when the plunger tip moves, and a wear condition measurement device that measures elastic waves propagating through the injection sleeve when the plunger tip moves, and a and a determination unit that determines the wear status. In the present invention, "abrasion" refers not only to wear on the sliding surfaces of the injection sleeve and plunger tip, but also to the formation of areas where sliding resistance increases due to scratches (damage) formed on the sliding surfaces. It is a broad concept that includes

As described above, the wear condition measuring device according to the first aspect of the present invention includes an elastic wave measuring section that measures elastic waves propagating through the injection sleeve when the plunger tip moves. By measuring high-frequency elastic waves (acoustic emissions, AE waves) generated by sliding between the plunger tip and the injection sleeve and propagating through the injection sleeve, the elastic waves can be measured according to the degree of wear on the sliding surface. It is possible to understand changes in Since elastic waves generated by sliding propagate through the injection sleeve, it is possible to detect even slight changes that cannot be measured as sliding sounds transmitted through the air or changes in injection pressure. By providing a determination unit that determines the wear status of at least one of the injection sleeve and the plunger tip based on the output signal of the elastic wave measurement unit, the wear status (progress of wear) can be determined from the output signal of the elastic wave measurement unit. can be grasped. Thereby, wear of the plunger tip and injection sleeve can be determined with high precision.

In the wear condition measuring device according to the first aspect, preferably, the elastic wave measuring section includes a propagation member having one end in contact with the injection sleeve and another end remote from the injection sleeve, and a propagation member on the other end side of the propagation member. An elastic wave detection sensor is attached to the injection sleeve and measures elastic waves propagating from the injection sleeve via the propagation member. With this configuration, for example, instead of measuring the elastic waves propagated to the mold holding part that holds the injection sleeve, the elastic waves generated due to the sliding between the plunger tip and the injection sleeve can be measured using the propagation member. By using this method, measurements can be taken directly from the injection sleeve. Further, since the injection sleeve becomes extremely high in temperature (several hundreds of degrees Celsius) due to the supply of molten metal, it is difficult to attach directly to the injection sleeve even if it is a heat-resistant sensor. Therefore, by propagating elastic waves through a propagation member that is in contact with the injection sleeve, elastic waves can be measured while suppressing the influence of heat on the elastic wave detection sensor.

In this case, preferably, the sleeve holder further includes a sleeve holder that holds the injection sleeve and fixes it to the mold holder, and a holder that holds the propagation member, and the holder is able to hold the injection sleeve without contacting the mold holder. It can be attached to the holding part or the mold holding part and is configured to bias one end of the propagation member against the injection sleeve. With this configuration, the contact state between the propagation member and the injection sleeve can be reliably maintained by the urging force of the holding member. Further, since the holding member can be attached to the sleeve holding part or the mold holding part which is a part of the die-casting machine, there is no need to separately provide a pedestal or the like for fixing the holding member in a predetermined position. Furthermore, since the holding member does not come into contact with the injection sleeve, even when replacing a worn injection sleeve, the holding member can be prevented from interfering with the replacement work.

The wear condition measuring device according to the first aspect preferably includes a signal processing section that calculates an elastic wave intensity index per unit time based on an output signal of the elastic wave measuring section acquired during movement of the plunger tip. Furthermore, the determination unit is configured to determine the degree of wear in at least one of the injection sleeve and the plunger tip based on the calculated strength index. With this configuration, based on the change in the intensity index per unit time during the movement (sliding) of the plunger tip, it is possible to detect, for example, the appearance of a sudden spike-like intensity peak or a significant displacement of the baseline. Based on the appearance, the degree of wear progress can be determined with high accuracy.

In the wear condition measuring device according to the first aspect, preferably, the determining unit acquires position information of the plunger tip when it is moved by the injection drive unit, and obtains the output signal of the elastic wave measuring unit and the position while the plunger tip is moving. Based on the information, the wear location of the injection sleeve is estimated. With this configuration, it is possible to determine where on the injection sleeve wear is progressing. Therefore, useful information can be obtained for considering adjustment of the assembly angle of the injection sleeve and injection drive unit and optimization of injection operation control in order to suppress the progression of wear.

The wear condition measuring device according to the first aspect preferably further includes an extraction processing section that extracts a signal component corresponding to an elastic wave having a frequency in the ultrasonic range from the output signal of the elastic wave measurement section. Here, the frequency in the ultrasonic range is a frequency of 20 kHz or more. With this configuration, for example, vibrations (displacement, chatter, etc.) that occur with injection operations, vibrations that are transmitted from other parts of the die-casting machine, etc., have a frequency that is sufficiently lower than that of the ultrasonic range. , such a vibration component can be removed to extract a signal component caused by sliding between the plunger tip and the injection sleeve. As a result, it is possible to improve the signal-to-noise ratio of the signal components involved in determining the wear status.

In the configuration including the above-mentioned holding member, preferably, the holding member is attached to the sleeve holding part or the mold holding part, and is provided between the first bracket that holds the propagation member and the first bracket and the propagation member. , and a biasing member that biases one end of the propagation member toward the injection sleeve. With this configuration, the first bracket can stably hold the propagating member, and the urging member urges the propagating member against the first bracket to connect one end of the propagating member and the injection sleeve. A contact state can be easily ensured.

In this case, preferably, the biasing member is a leaf spring disposed between the first bracket and the propagating member in a deformed state that biases one end of the propagating member toward the injection sleeve, or a leaf spring that biases one end of the propagating member toward the injection sleeve. a compression coil spring disposed between the first bracket and the propagation member in a compressed state biasing the transmission member; With this configuration, when the biasing member is a leaf spring, the first bracket can more stably hold the propagation member via the relatively rigid leaf spring. When the biasing member is a compression coil spring, vibration is generated between the first bracket and the propagation member compared to a case where a relatively rigid biasing member is interposed between the first bracket and the propagation member. This makes it difficult for vibrations (noise) transmitted from the sleeve holder side or mold holder side of the die-casting machine to which the first bracket is attached to be transmitted to the elastic wave detection sensor attached to the propagation member. be able to.

The wear condition measuring device according to the first aspect preferably further includes a sleeve holding part that holds the injection sleeve and fixes it to the mold holding part, and the elastic wave measuring part has one end that comes into contact with the injection sleeve. a second bracket that is attached to the sleeve holding part or the mold holding part and that directly holds the propagation member and brings one end of the propagation member into contact with the injection sleeve; and an elastic wave detection sensor that measures elastic waves propagating from the injection sleeve through the injection sleeve. With this configuration, the second bracket can directly hold the propagation member, and the second bracket has the function of attaching it to the sleeve holding part or the mold holding part, the function of attaching the elastic wave detection sensor, and the function of attaching the propagation member to the second bracket. It can have multiple functions such as the function of holding a member. Therefore, compared to the case where the propagation member is held indirectly by the second bracket or the case where each of the above functions is provided separately to a plurality of members, the device configuration of the wear condition measuring device can be simplified.

In this case, the second bracket is preferably formed such that the thickness of the portion on the side that holds the propagation member is smaller than the thickness of the portion to which the elastic wave detection sensor is attached. With this configuration, the thickness of the portion of the second bracket that holds the propagating member from the propagating member can be made relatively thin, so that the elastic waves transmitted from the propagating member to the second bracket can reduce the thickness of the second bracket. By vibrating the portion relatively largely, it is possible to improve the detection accuracy of elastic waves by the elastic wave detection sensor.

A die casting machine according to a second aspect of the present invention includes: a mold holding part that holds a mold having a cavity; a cylindrical injection sleeve to which molten metal is supplied; A plunger tip that injects the molten metal supplied to the sleeve into the cavity, an injection drive unit that moves the plunger tip forward and backward within the injection sleeve, and an elastic wave measurement unit that measures elastic waves that propagate through the injection sleeve when the plunger tip moves. and a determination unit that determines the wear status of at least one of the injection sleeve and the plunger tip based on the output signal of the elastic wave measurement unit.

A die casting machine according to a second aspect of the present invention, like the first aspect, includes an elastic wave measuring section that measures elastic waves propagating through the injection sleeve when the plunger tip moves. By measuring high-frequency elastic waves (acoustic emissions, AE waves) generated by sliding between the plunger tip and the injection sleeve and propagating through the injection sleeve, the elastic waves can be measured according to the degree of wear on the sliding surface. It is possible to understand changes in By providing a determination unit that determines the wear status of at least one of the injection sleeve and the plunger tip based on the output signal of the elastic wave measurement unit, the wear status (progress of wear) can be determined from the output signal of the elastic wave measurement unit. can be grasped. Thereby, wear of the plunger tip and injection sleeve can be determined with high accuracy.

According to the present invention, as described above, wear of the plunger tip and the injection sleeve can be determined with high accuracy.

FIG. 1 is a schematic diagram showing the overall configuration of a die-casting machine equipped with a wear condition measuring section. FIG. 2 is a block diagram for explaining a wear condition measuring section and a control device of a die-casting machine. It is a typical graph for explaining the movement control of the plunger chip in the injection process of a die-casting machine. FIG. 3 is a schematic diagram for explaining wear that occurs on sliding parts and elastic waves that occur as the sliding parts slide. FIG. 3 is a schematic enlarged plan view of the vicinity of the injection sleeve, showing the structure of the elastic wave measuring section of the first embodiment. FIG. 3 is a schematic diagram for explaining the shape of one end of the propagation member that contacts the injection sleeve. 2 is a graph schematically showing an output signal of an AE sensor after frequency filter processing. 3 is a graph schematically showing intensity index data generated from an output signal of an AE sensor. These are graphs of strength index-position change data generated from strength index data and position information of the plunger tip, including (A) a graph when the wear of sliding parts progresses, and (B) a graph when normal. It is a schematic diagram. FIG. 3 is a flowchart for explaining a process for measuring the wear status of sliding parts. FIG. 7 is a schematic enlarged plan view of the vicinity of the injection sleeve showing the structure of the elastic wave measuring section of the second embodiment. FIG. 7 is a schematic enlarged plan view of the vicinity of the injection sleeve showing the structure of the elastic wave measuring section of the third embodiment. FIG. 2 is a schematic diagram showing a configuration example of a wear condition measuring device independent of a die-casting machine. It is a schematic diagram which shows the modification example (A) and (B) of the shape of one end of a propagation member.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described based on the drawings.

(First embodiment)
With reference to FIGS. 1 to 9, the configuration of a die casting machine 1 equipped with a wear condition measuring section 8 according to the first embodiment will be described. The wear condition measuring section 8 is an example of a "wear condition measuring device" in the claims. In the drawings, the Z direction is defined as an up-down direction, the Z1 direction of the Z directions is defined as an upward direction, and the Z2 direction of the Z directions is defined as a downward direction. Further, the X direction and the Y direction are two directions perpendicular to each other in the horizontal plane, the X1 direction of the X directions is the forward direction of the plunger chip 6a, which will be described later, and the X2 direction of the X directions is the backward direction of the plunger chip 6a. direction.

(Die casting machine configuration)
As shown in FIG. 1, the die casting machine 1 is a horizontal machine in which a movable mold 2a is moved in the horizontal direction. The die casting machine 1 is a cold chamber type machine, and a liquid metal material is placed in a mold 2 attached to the die casting machine 1 (a cavity C formed by a moving mold 2a and a fixed mold 2b). It is configured to manufacture die-cast products (molded products) by injecting molten metal.

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. The die casting machine 1 in FIG. 1 also includes a hot water supply device 9, a lid mechanism 10, a mold clamping section 11, a control device 12, a display section 13, and an alarm 14.

The mold holding part 3 holds the mold 2 having a cavity C. The mold holding part 3 includes a fixed die plate 3a and a movable die plate 3b.

The mold 2 includes a movable mold 2a and a fixed mold 2b. The fixed mold 2b is fixed to a fixed die plate 3a. The movable mold 2a is attached to a movable die plate 3b that is movable in a direction (X direction) in which it comes into contact with or separates from the fixed mold 2b. The cavity C is formed by bringing the movable mold 2a into contact with the fixed mold 2b. Cavity C is a hollow portion for molding a die-cast product (molded product).

The movable die plate 3b is moved in the X direction by the mold clamping section 11. The mold clamping section 11 includes a driving section 11a that drives the movable die plate 3b. The drive unit 11a is, for example, an electric motor, and drives the movable die plate 3b in the X direction by a transmission mechanism 11b such as a ball screw shaft. The drive unit 11a is not limited to an electric drive unit, but may be a hydraulic drive unit that drives a transmission mechanism including a toggle mechanism, or may be a hybrid drive unit that combines an electric drive and a hydraulic drive. .

The injection section 4 includes an injection sleeve 5, a plunger 6, and an injection drive section 7.

The injection sleeve 5 has a cylindrical shape with both ends open. The injection sleeve 5 extends linearly in the X direction. The injection sleeve 5 is fixed to the mold holder 3 via a sleeve holder 40. The sleeve holding part 40 has a cylindrical shape, and holds the injection sleeve 5 by inserting the injection sleeve 5 therethrough. 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 be capable of pouring molten metal. The injection sleeve 5 is configured to slidably accommodate the plunger tip 6a within the injection sleeve 5. Sliding is relative movement while in contact.

Specifically, the injection sleeve 5 includes a pouring port 5a and a molten metal passage 5b. The pouring port 5a is provided for pouring molten metal into the molten metal passage 5b by the hot water supply device 9. The pouring port 5a penetrates the upper side (Z1 direction side) of the injection sleeve 5 in the Z direction. The molten metal passage 5b is a through hole that penetrates the injection sleeve 5 in the X direction. The molten metal passage 5b communicates with the cavity C at the end in the X1 direction.

Plunger 6 includes a plunger tip 6a and a plunger rod 6b. The plunger tip 6a is slidably arranged within the injection sleeve 5. The plunger chip 6a is attached to one end (the end on the X1 direction side) of the plunger rod 6b. The plunger rod 6b has a columnar shape extending along the X direction. The other end of the plunger rod 6b (the end on the X2 direction side) is attached to the piston rod of the injection drive section 7 (hydraulic cylinder 7a). The plunger tip 6a is configured to inject the molten metal supplied to the injection sleeve 5 into the cavity C by being moved forward and backward within the injection sleeve 5 by the injection drive unit 7 via the plunger rod 6b.

The injection drive unit 7 is configured to move the plunger tip 6a forward and backward within the injection sleeve 5. The injection drive unit 7 includes a hydraulic cylinder (hydraulic cylinder) 7a operated by hydraulic pressure (hydraulic pressure) and a hydraulic circuit 7b. The hydraulic cylinder 7a is connected to a hydraulic circuit 7b and is configured to be operated by the hydraulic circuit 7b. The position (X-direction position) of the plunger tip 6a moved by the hydraulic cylinder 7a is detected by the position sensor 7c.

The position sensor 7c is configured to detect the position of the plunger tip 6a (stroke amount 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 device.

The hot water supply device 9 is configured to draw molten metal, which is a liquid metal material, from a holding furnace (not shown) and supply (pouring) the molten metal to the injection sleeve 5 . Specifically, the water heater 9 includes a ladle 9a and an arm 9b. The ladle 9a is a container for pumping molten metal, which is a liquid metal material, from the holding furnace. The arm 9b is configured to move the ladle 9a to the pouring port 5a of the injection sleeve 5 and tilt the ladle 9a to pour molten metal into the injection sleeve 5.

The lid mechanism 10 is configured to close the pouring port 5a after molten metal is poured into the injection sleeve 5 by the hot water supply device 9. Specifically, the lid mechanism 10 includes a lid portion 10a and an arm 10b. The lid portion 10a has a shape that follows the shape of the pouring spout 5a when viewed from the Z1 direction. The lid portion 10a is arranged at the tip of the arm 10b. The arm 10b is configured to move the lid 10a to the spout 5a.

The wear condition measuring section 8 includes an elastic wave measuring section 8a and a determining section 8b.

The elastic wave measuring section 8a is configured to measure an elastic wave EW (see FIG. 4) propagating through the injection sleeve 5 when the plunger tip 6a moves.

The determination unit 8b is configured to determine the wear status of at least one of the injection sleeve 5 and the plunger tip 6a based on the output signal of the elastic wave measurement unit 8a. Hereinafter, the injection sleeve 5 and the plunger tip 6a will be collectively referred to as the sliding part SP (see FIG. 3).

The control device 12 is configured to control the driving of each part of the die casting machine 1. The control device 12 is electrically connected to each part of the die-casting machine 1. As shown in FIG. 2, the control device 12 includes a control section 12a and a storage section 12b. The control unit 12a is configured by a computer including, for example, a processor such as a CPU (Central Processing Unit), and a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage unit 12b includes a nonvolatile recording medium such as a flash memory. Further, the control device 12 includes a display section 13.

The storage unit 12b stores programs to be executed by the control unit 12a (processor). The storage unit 12b is configured to store measurement data (intensity index-position change data 22d described later) by the elastic wave measurement unit 8a. Furthermore, the storage unit 12b stores in advance setting information such as a determination threshold value for determining the wear status of the sliding part SP from the measurement data by the elastic wave measurement unit 8a.

The display unit 13 includes a display medium such as a liquid crystal monitor, and is configured to display various information related to the die casting machine 1. The alarm 14 is, for example, an indicator light. The indicator light includes a light emitting part such as a lamp, and is configured to notify the user by lighting or blinking. Furthermore, the alarm 14 includes a speaker that outputs a buzzer sound.

(Summary of injection process)
Next, with reference to FIGS. 3 and 1, an outline of the operation of the injection process by the die-casting machine 1 will be explained. The injection process is executed by the control unit 12a controlling each part of the die casting machine 1.

First, the control unit 12a controls the hot water supply device 9 to pour molten metal into the injection sleeve 5 from the pouring port 5a of the injection sleeve 5 shown in FIG. Controls the lid mechanism 10.

After the pouring port 5a is closed, the control section 12a controls the injection drive section 7 to perform the injection process. As shown in FIG. 3, the injection process is roughly divided into an injection forward process shown in FIG. 3(A) and an injection return process shown in FIG. 3(B). The horizontal axes of the graphs in FIGS. 3A and 3B indicate the position of the plunger tip 6a in the X direction, which corresponds to the schematic diagram inside the injection sleeve 5 shown in the upper part of the drawings. The vertical axis of the graph represents the moving speed of the plunger tip 6a. On the vertical axis, the positive direction (upward direction in the figure) represents the speed in the X1 direction (forward direction), and the negative direction (downward direction in the figure) represents the speed in the X2 direction (backward direction).

The injection advancement step in FIG. 3A is a step in which the plunger tip 6a is advanced in the X1 direction within the injection sleeve 5 to inject the molten metal into the mold 2. In addition, in the injection return step of FIG. 3(B), the plunger tip 6a that was advanced in the forward injection step is moved backward in the X2 direction within the injection sleeve 5, and the plunger tip 6a is placed in a standby position for injection of the next molten metal. This is the process of moving the

The injection advance step in FIG. 3(A) includes a low speed advance step and a high speed advance step. The control unit 12a controls the injection drive unit 7 to switch between a low-speed injection process in which the plunger tip 6a is moved at a low speed and a high-speed injection process in which the plunger tip 6a is moved at a high speed. The low-speed injection step is a step in which the plunger tip 6a is moved using the first speed V1 as the target speed. Further, the high-speed injection step is a step in which the plunger tip 6a is moved at a second speed V2, which is a higher speed than the first speed V1, as a target speed. The position where the low speed forward step is switched to the high speed forward step (high speed switching position Cp) is the position where the plunger tip 6a closes the injection sleeve 5 so that the pressure inside the injection sleeve 5 does not escape from the pouring port 5a. Specifically, the high-speed switching position Cp is set at a position where the surface of the plunger tip 6a on the X1 direction side reaches the X1 direction side from the end of the pouring spout 5a on the X1 direction side. Note that the low-speed forward step is performed to increase the filling rate of the molten metal in the injection sleeve 5. Further, the high-speed advance step is performed to spread the molten metal into the mold 2 (cavity C). After the high-speed advance step, after a holding step in which the pressure inside the cavity C is maintained in a high state to solidify the molten metal, the mold is opened (separation of the movable mold 2a and the fixed mold 2b) and the molding is completed. The product is ejected from the mold 2.

After that, the control section 12a controls the injection drive section 7 to perform the injection return process. The injection return process is a process of moving the plunger tip 6a in the X2 direction to the standby position with the third speed V3 as the target speed. One injection process includes one injection forward process and one injection return process. Note that one injection process is also referred to as "one shot." The control section 12a controls the position and speed of the plunger tip 6a (the operation of the injection drive section 7) in the injection process based on the position information PI (see FIG. 2) of the plunger tip 6a acquired by the position sensor 7c (see FIG. 2). ).

(Configuration of wear condition measuring section)
Next, details of the wear condition measuring section 8 will be explained.

<Explanation of elastic waves generated due to sliding>
As shown in FIG. 4, the plunger tip 6a has a fitting dimension that allows it to slide on the inner surface of the injection sleeve 5 without coming into close contact with it, and to push out the molten metal M without leaking injection pressure. It is located in Every time an injection operation is performed, the plunger tip 6a and the injection sleeve 5 come into contact (slide), and their sliding surfaces (the outer surface of the plunger tip 6a and the inner surface of the injection sleeve 5) are worn out. When the gap CL between the sliding surfaces increases due to wear, a phenomenon called backflush occurs in which pressure leaks from the gap CL as shown in FIG. 4. Further, since the molten metal M for aluminum die casting, for example, reaches a high temperature of around 700° C., the injection sleeve and plunger tip 6a in contact with the molten metal M are deformed. When the plunger tip 6a and the injection sleeve 5 come into contact with each other due to impact during the injection operation due to the deformation, scratches DG are formed on the sliding surface, causing "galling". These wears (increase in the gap CL and occurrence of scratches DG) occurring in the sliding part SP gradually progress (enlarge) by repeating the injection process.

When the plunger tip 6a slides within the injection sleeve 5, a sound wave is generated depending on the sliding resistance. The generated sound waves propagate through the injection sleeve 5 as elastic waves EW. Such elastic waves EW are called acoustic emissions (AE waves) and belong to a frequency band in the ultrasonic range from several tens of kHz to several MHz. Since the elastic wave EW is generated by sliding between the plunger tip 6a and the injection sleeve 5, it reflects the wear status of the sliding parts SP (the plunger tip 6a and the injection sleeve 5). The wear condition measuring unit 8 of the first embodiment measures the elastic waves EW propagating inside the injection sleeve 5 to grasp the wear condition of these sliding parts SP (plunger tip 6a and injection sleeve 5). It is.

<Elastic wave measurement section>
As shown in FIG. 5, the elastic wave measurement unit 8a includes a propagation member 21 and an acoustic emission sensor (hereinafter referred to as AE sensor 22). The acoustic emission sensor (AE sensor) 22 is an example of an "acoustic wave detection sensor" in the claims.

The propagation member 21 is a rod-shaped (thin plate-shaped) member that contacts the injection sleeve 5 and propagates the elastic wave EW (see FIG. 4) from the injection sleeve 5 to the propagation member 21. The propagation member 21 has one end 21 a that contacts the injection sleeve 5 and the other end 21 b that is remote from the injection sleeve 5 . The elastic wave EW propagating within the injection sleeve 5 is transmitted from one end 21a to the propagation member 21, and propagated to the other end 21b. The propagation member 21 is made of the same iron-based material as the injection sleeve 5. The injection sleeve 5 is made of a steel material (iron material) such as tool steel, and the propagation member 21 is made of a steel material (iron material) like the injection sleeve 5. Thereby, the propagation characteristics of the elastic wave EW in the propagation member 21 can be brought close to the propagation characteristics of the injection sleeve 5.

Although the shape of the end surface (the shape of the contact surface with the injection sleeve 5) of the one end 21a of the propagation member 21 is not particularly limited, for example, as shown in FIG. It has a curved concave shape. Thereby, the interface between the injection sleeve 5 and the one end 21a of the propagation member 21 can be brought into close contact with each other, so that the loss of the elastic wave EW at the interface can be reduced. In the example shown in FIG. 5, the propagation member 21 is bent between one end 21a and the other end 21b so as not to interfere with the structure near the injection sleeve 5 of the die-casting machine 1, but the propagation member 21 is linear. It may extend to

The AE sensor 22 is attached to the other end 21b side of the propagation member 21. In FIG. 5, the AE sensor 22 is attached to the other end 21b of the propagation member 21 and is spaced apart from the injection sleeve 5 by a distance D1. The AE sensor 22 detects an elastic wave EW (see FIG. 4) propagating from the injection sleeve 5 via the propagation member 21. The AE sensor 22 has a piezoelectric element such as PZT (lead zirconate titanate), and outputs a signal according to pressure fluctuations (strain) acting on the piezoelectric element caused by the propagation of the elastic wave EW to the AE sensor 22. do. Note that there is an acceleration sensor as a sensor that has a piezoelectric element, but whereas an acceleration sensor attaches a weight to the piezoelectric element and outputs a signal according to the displacement of the weight, an AE sensor does not have a weight and uses a piezoelectric element. The difference is that pressure fluctuations that act directly on the element are detected. Due to the difference in resonance frequency caused by the presence or absence of a weight, an acceleration sensor has sensitivity in a frequency band of several Hz to several tens of kHz, whereas the AE sensor 22 has sensitivity in a frequency band of several tens of kHz to 1 MHz. .

In the example of FIG. 5, the wear condition measuring section 8 (elastic wave measuring section 8a) includes a holding member 23 that holds the propagation member 21. The holding member 23 can be attached to the sleeve holding part 40 without contacting the injection sleeve 5, and is configured to urge one end 21a of the propagation member 21 against the injection sleeve 5.

Specifically, the holding member 23 includes a bracket 24 attached to the sleeve holding part 40, a biasing member 25, and an adjusting member 26. The bracket 24 is an example of a "first bracket" in the claims. The bracket 24 has an L-shape, and one end of the bracket 24 is fixed to the sleeve holding part 40 with a bolt 27. The bracket 24 is attached to the sleeve holding section 40 and holds the propagation member 21. Specifically, the bracket 24 is fixed to the edge of the sleeve insertion opening 40c to which the injection sleeve 5 is attached in the sleeve holding portion 40 without contacting the injection sleeve 5. In FIG. 5, bracket 24 is attached to sleeve holder 40. In FIG. If the injection sleeve 5 is attached to the fixed die plate 3a via an intermediate plate (not shown), the bracket 24 may be attached to the intermediate plate. The other end of the bracket 24 extends generally parallel to the injection sleeve 5.

The biasing member 25 is provided at the other end of the L-shaped bracket 24 and between the bracket 24 and the propagation member 21 . The biasing member 25 is attached to the bracket 24 by an adjustment member 26 without contacting the injection sleeve 5. The biasing member 25 is disposed between the bracket 24 and the propagation member 21 in a deformed state that biases one end 21 a of the propagation member 21 toward the injection sleeve 5 . The biasing member 25 is a leaf spring bent into a U-shape, one end of the biasing member 25 is fixed to the bracket 24, and the propagation member 21 is fixed to the other end of the biasing member 25. There is.

The adjustment member 26 is a bolt (threaded member) that engages with a screw hole formed at the other end of the bracket 24 . The adjustment member 26 extends toward the injection sleeve 5 through both one end and the other end of the U-shaped biasing member 25 and is attached to the other end of the bracket 24 . Therefore, the biasing member 25 is sandwiched between the bracket 24 and the screw head of the adjusting member 26. As the adjustment member 26 is rotated to bring the screw head closer to the bracket 24, the other end of the biasing member 25 is brought closer to the injection sleeve 5. The amount of rotation of the adjustment member 26 adjusts the pressing force that presses the one end 21a of the propagation member 21 attached to the other end of the biasing member 25 against the injection sleeve 5.

With this configuration, the propagation member 21 is urged toward the injection sleeve 5 by the holding member 23 (biasing member 25) so that the one end 21a is kept in contact with the injection sleeve 5 at all times.

In the example of FIG. 5, the propagation member 21 is arranged at a position overlapping the pouring port 5a of the injection sleeve 5 in the X direction (the position of the propagating member 21 in the X direction is within the forming range of the pouring port 5a in the X direction). ing. The propagation member 21 is arranged toward the Y direction so as to contact the side surface of the injection sleeve 5 in the horizontal direction (Y direction) from a position apart from the side surface in the horizontal direction (Y direction) with respect to the injection sleeve 5. ing. Note that in the side view shown in FIG. 1, the elastic wave measuring section 8a including the propagation member 21 cannot be shown as it is, so for convenience, the elastic wave measuring section 8a is shown on the lower side with respect to the injection sleeve 5 in FIG. Illustrated.

(Signal processing of wear condition measuring section)
As shown in FIG. 2, the wear condition measurement section 8 includes an amplifier unit 8c, an arithmetic unit 8d, and the above-described determination section 8b. The AE sensor 22 is connected to the determination section 8b (the control section 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 output voltage signal.

The amplifier unit 8c includes an amplification section 31, an extraction processing section 32, and an AD conversion section 33. The amplification unit 31 acquires the output signal 22a from the AE sensor 22, and amplifies the acquired output signal 22a with a preset amplification factor.

The extraction processing section 32 extracts a signal component corresponding to the elastic wave EW having a frequency in the ultrasonic range from the output signal 22a of the elastic wave measurement section 8a. That is, the extraction processing unit 32 acquires the output signal (output voltage) amplified by the amplification unit 31 and performs frequency filter processing on the acquired output signal, thereby extracting a signal component of a frequency in a preset ultrasonic range. Extract. The frequency filtering includes at least high-pass filtering that removes frequency components lower than a low frequency threshold. The frequency filter processing in the first embodiment is band pass filter processing (a combination of a high pass filter and a low pass filter).

The extraction processing unit 32 extracts at least signal components of 20 kHz or more (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 extracts signal components of frequencies in the ultrasonic range of, for example, 50 kHz or more and less than 500 kHz (removes signal components of less than 50 kHz and signal components of 500 kHz or more). As a result, signal components in frequency bands that are unnecessary for determining the wear status of the sliding part SP are removed, leaving signal components in the frequency band corresponding to the elastic waves EW caused by the sliding of the sliding part SP.

The A/D conversion section 33 performs A/D conversion processing on the output signal (the signal from which the amplification and signal components have been extracted) that has passed through the amplification section 31 and the extraction processing section 32 . Thereby, 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 an output voltage value (digital value) after frequency filter processing by the extraction processing unit 32. FIG. 7 is a graph showing the output signal 22b, where the horizontal axis represents time and the vertical axis represents the output voltage value.

Returning to FIG. 2, the arithmetic unit 8d is constituted by a computer including a processor and a memory, and is communicably connected to the amplifier unit 8c and the control section 12a. The arithmetic unit 8d acquires the digitally converted output signal 22b of the AE sensor 22 from the amplifier unit 8c as measurement data of the elastic wave measuring section 8a.

The arithmetic unit 8d includes a signal processing section 34 as a functional block for software processing by executing a program stored in a 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 measurement unit 8a (AE sensor 22) acquired when the plunger tip 6a moves. ing.

The strength index of the elastic wave EW can be the maximum amplitude of the output signal in unit time, the energy of the output signal in unit time, or the effective value of the output signal in unit time. In the first embodiment, the signal processing unit 34 calculates the energy of the output signal per unit time from the time-varying waveform of the output signal 22b (see FIG. 7).

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. Thereby, the signal processing unit 34 generates intensity index data 22c based on the time change of the output signal 22b of the elastic wave measurement unit 8a (AE sensor 22), and outputs the generated intensity index data 22c to the determination unit 8b. do. The intensity index data 22c is data obtained by converting the output signal of the AE sensor 22 into a time-varying waveform of energy (intensity index). FIG. 8 is a graph showing the intensity index data 22c, where the horizontal axis represents time and the vertical axis represents the intensity index (energy).

As shown in FIG. 2, in the first embodiment, the determination unit 8b is executed by the same processor as the control unit 12a as a functional block of software processing by the control unit 12a executing the program stored in the storage unit 12b. It is configured. In other words, the control section 12a of the die-casting machine 1 also functions as the determination section 8b of the wear condition measurement section 8 by executing the program. The control device 12 may separately include a processor for the control section 12a and a processor for the determination section 8b.

The determination unit 8b determines the wear status of at least one of the injection sleeve 5 and the plunger tip 6a based on the output signal (intensity index data 22c) of the elastic wave measurement unit 8a. Specifically, the determination unit 8b is configured to determine the degree of wear in at least one of the injection sleeve 5 and the plunger tip 6a based on the output signal (intensity index data 22c) of the elastic wave measurement unit 8a. There is.

Here, in the first embodiment, the determination unit 8b acquires position information PI of the plunger tip 6a during movement by the injection drive unit 7. That is, the determination unit 8b acquires the position of the plunger tip 6a in the X-axis direction in 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 change data of the position of the plunger chip 6a in the X-axis direction.

The determination unit 8b is configured to estimate the wear location of the injection sleeve 5 based on the output signal (intensity index data 22c) of the elastic wave measurement unit 8a while the plunger tip 6a is moving and the position information PI. ing. Specifically, the determination unit 8b determines the position of the plunger tip 6a based on the intensity index data 22c (that is, the temporal change in energy value) and the position information PI (the position of the plunger tip 6a in the X-axis direction at each time). Intensity index-position change data 22d indicating changes in the intensity index for each position in the X-axis direction is generated. As shown in FIG. 9, the intensity index-position change data 22d can be expressed as graphs (graphs 41a, 41b) in which the horizontal axis is the position coordinate of the plunger chip 6a in the X-axis direction and the vertical axis is the intensity index (energy). I can do it. Then, the determination unit 8b estimates the degree of wear of the plunger tip 6a for each position from the strength index-position change data 22d.

The determination unit 8b acquires the strength index-position change data 22d every shot (one injection process) of the die-casting machine 1, and determines the wear of the sliding part SP every time the strength index-position change data 22d is acquired. Assess the situation. The determination unit 8b determines whether or not to issue a notification based on the wear status of the sliding component SP. When the wear status of the sliding part SP satisfies the notification conditions, the determination unit 8b displays information on the display unit 13 of the control device 12 and provides notification using the alarm 14. The operator who receives the notification considers whether or not to replace the sliding part SP, and if it is determined that it is necessary, can replace at least one of the injection sleeve 5 and the plunger tip 6a.

<An example of a method for determining wear status>
Hereinafter, an example of a method for determining the wear status of the sliding component SP by the determining section 8b will be explained.

The graph 41a shown in FIG. 9(A) is a plot of the strength index-position change data 22d acquired in the injection advance process in a state where the sliding part SP has progressed to wear and needs to be replaced. The graph 41b shown in FIG. 9(B) is strength index-position change data obtained during the injection advance process in a normal state where the sliding part SP is not worn out, such as immediately after the sliding part SP is replaced. 22d is plotted.

First, the overall trend of the intensity index-position change data 22d will be explained using the normal graph 41b. In the injection advance process, when the plunger tip 6a starts moving forward from a stationary state at the standby position (the right end of graphs 41a and 41b), the strength index temporarily spikes because the state of static friction changes to the state of dynamic friction. rises like a figure. Thereafter, in the low-speed forward step, the plunger tip 6a moves at a constant low speed, so the strength index remains approximately constant at a low level. At the timing when the plunger tip 6a reaches the high-speed switching position Cp and switches to the high-speed advance step, the strength index starts to rise as the moving speed of the plunger tip 6a changes. In the high-speed advance process, the pressure within the injection sleeve 5 may increase as the plunger tip 6a advances, and the strength index tends to increase. At the end of the high-speed advance process, the reaction force transmitted from the cavity C through the molten metal M rapidly increases, so that the strength index rapidly increases.

In the graph 41a in which the wear of the sliding part SP is progressing, spike-shaped peaks 42 with clearly higher intensity than in the graph 41b occur at multiple positions in the X direction. From this, it can be seen that "galling" or similar local wear is formed at the location where the peak 42 occurs in the injection sleeve 5. Therefore, local wear of the injection sleeve 5 can be detected by setting the threshold Th1 to an intensity index value that is higher than the maximum intensity in the normal graph 41b and that allows the peak 42 in the graph 41a to be determined.

The determination unit 8b determines the wear status of the injection sleeve 5 (whether local wear has occurred or not) based on whether a peak 42 greater than or equal to a preset threshold value Th1 exists in the strength index-position change data 22d. (Location of local wear) is determined.

Furthermore, in the graph 41a in which the sliding component SP is showing progressing wear, the baseline 43 of the intensity waveform is rising compared to the graph 41b. That is, in the graph 41a, an elastic wave EW with a higher intensity than in the graph 41b occurs over the entire range of the stroke of the plunger tip 6a. The increase in the strength index that does not depend on the position of the plunger tip 6a in the X direction as described above is considered to be due to wear occurring not on the injection sleeve 5 but on the sliding surface side of the plunger tip 6a. Therefore, wear of the plunger tip 6a can be detected by setting the threshold Th2 to an intensity index value that can distinguish the intensity of the baseline 43 in the graph 41b from the intensity of the baseline 43 in the graph 41a.

The determination unit 8b determines the wear status of the plunger tip 6a (whether or not wear has occurred) based on whether the baseline 43 of the strength index-position change data 22d is greater than or equal to a preset threshold Th2. .

In the example described above, the determination unit 8b determines the wear status from the strength index-position change data 22d of the injection forward step. In addition, the wear status may be determined from the strength index-position change data 22d in the injection return process shown in FIG. In the injection return process, since the molten metal M (see FIG. 4) is not accommodated in the injection sleeve 5, the deformation of the sliding part SP due to the molten metal temperature is suppressed, and the reaction force due to the molten metal M acts on the plunger tip 6a. do not. Therefore, the waveform of the intensity index-position change data 22d acquired in the injection return process is different from that shown in FIG. Therefore, in another example, the determination unit 8b determines the wear status of the sliding part SP based on the strength index-position change data 22d in the injection return process as well as the strength index-position change data 22d in the injection forward process. Determine. Thereby, it is possible to detect a wear situation that cannot be grasped only by the strength index-position change data 22d of the injection advance process, and to improve the accuracy of detecting the wear situation.

Furthermore, the method for determining the wear status of the sliding component SP is not limited to the above-mentioned method. For example, data (graph 41b) of a normal state in which the sliding part SP is not worn out is stored in the storage unit 12b, and the stored normal data (graph 41b) and the data are acquired for each shot. The wear status may be determined by comparing the strength index and the position change data 22d. Wear of the sliding part SP gradually progresses with each shot. Therefore, as the number of injections increases, the obtained intensity index-position change data 22d gradually approaches the waveform of the graph 41a from the waveform of the graph 41b in a normal state to the waveform of the graph 41a in which wear has progressed. Therefore, the determination unit 8b calculates, for example, the difference, degree of deviation (similarity), or correlation function between the waveform of the graph 41b in the normal state and the waveform obtained from the acquired intensity index-position change data 22d. The degree of wear may also be determined by

(Measurement process of wear status of sliding parts)
Referring to FIG. 10, the process of measuring the wear status of the sliding component SP by the determination unit 8b will be described. The measurement process of the wear condition is performed for each shot of the molding operation by the die-casting machine 1. The following flow is assumed to start from the timing when the molten metal M is poured into the injection sleeve 5 and the pouring port 5a is closed by the lid mechanism 10 after pouring.

In step S1, the determination unit 8b starts elastic wave measurement at the start of the injection process of the die-casting machine 1. That is, when the control section 12a starts controlling the injection sleeve 5 to execute the injection advance step, the determination section 8b determines the output signal from the AE sensor 22 of the elastic wave measurement section 8a to the calculation unit 8d. Instruct to start collection. The output signal from the AE sensor 22 is output to the determination unit 8b in the form of intensity index data 22c (temporal change in intensity index, see FIG. 8) through processing in each of the amplifier unit 8c and the calculation unit 8d.

After the forward injection process is completed in the die casting machine 1 and the molded product is taken out from the mold 2 by opening the mold, the die casting machine 1 performs the return injection process. The determination unit 8b also acquires intensity index data 22c in the injection return process from the calculation unit 8d.

In step S2, the determination unit 8b ends the elastic wave measurement at the end of the injection return process of the die-casting machine 1. Strictly speaking, the determination unit 8b either performs two measurements: the elastic wave measurement in the injection forward process and the elastic wave measurement in the injection return process, or Perform one measurement until the end of the process.

In step S3, the determination unit 8b determines the intensity index-position change data 22d( (see Figure 9).

In step S4, the determination unit 8b determines the wear status of the sliding component SP based on the strength index-position change data 22d. As described above, the determination of the wear condition includes determining the wear location of the injection sleeve 5 and the degree of wear at the wear location (whether or not the peak 42 is equal to or higher than the threshold value). Further, the determination of the wear state includes determining whether or not the plunger tip 6a is worn.

In step S5, the determination unit 8b determines whether or not to issue a notification based on the determination result of the wear status of the sliding component SP. The notification conditions are stored in advance in the storage unit 12b as setting information. The notification conditions may include, for example, that a set number (a predetermined number of 1 or more) of peaks 42 that are greater than or equal to a threshold value have been detected, or that the intensity of the baseline 43 has exceeded the threshold value Th2. As information other than the measurement data, the notification conditions may 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 shots.

If the determination unit 8b determines in step S5 that the notification condition is satisfied, the process proceeds to step S6, and after performing notification processing by one or both of the display unit 13 and the alarm 14, the determination process ends. When determining in step S5 that the notification condition is not satisfied, the determination unit 8b ends the determination process without performing the notification process.

By executing each of the above steps for each injection process of the die-casting machine 1, the wear status of the sliding part SP is notified to the operator at the timing when the wear status corresponds to the preset notification condition. Implemented.

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

As described above, the first embodiment includes the elastic wave measuring section 8a that measures the elastic wave EW propagating through the injection sleeve 5 when the plunger tip 6a moves. Thereby, by measuring the high-frequency elastic wave EW generated by sliding between the plunger tip 6a and the injection sleeve 5 and propagating through the injection sleeve 5, changes in the elastic wave EW according to the degree of wear on the sliding surface are measured. can be understood. Since the elastic wave EW generated by the sliding propagates through the injection sleeve 5, it is possible to detect even a slight change that is not measured as a sliding sound transmitted in the air or a change in the injection pressure. By providing a determination section 8b that determines the wear condition of at least one of the injection sleeve 5 and the plunger tip 6a based on the output signal of the elastic wave measurement section 8a, the wear condition (wear progress). Thereby, the wear of the plunger tip 6a and the injection sleeve 5 can be determined with high precision.

Further, in the first embodiment, as described above, the elastic wave measuring section 8a includes a propagation member 21 having one end 21a in contact with the injection sleeve 5 and the other end 21b remote from the injection sleeve 5; It includes an AE sensor 22 that is attached to the other end 21b side and measures the elastic wave EW propagating from the injection sleeve 5 via the propagation member 21. As a result, instead of measuring the elastic wave EW propagated to the mold holding part 3 side that holds the injection sleeve 5, for example, the elastic wave EW generated due to sliding between the plunger tip 6a and the injection sleeve 5 is measured. By using the member 21, it is possible to directly measure from the injection sleeve 5. Furthermore, since the injection sleeve 5 becomes extremely high temperature (around 700°C in the first embodiment) due to the supply of the molten metal M, it is difficult to directly attach the sensor to the injection sleeve 5 even if it is a heat-resistant sensor. be. Therefore, by propagating the elastic wave EW through the propagation member 21 that is in contact with the injection sleeve 5, the elastic wave EW can be measured while suppressing the influence of heat on the AE sensor 22.

Further, in the first embodiment, as described above, the holding member 23 can be attached to the sleeve holding portion without contacting the injection sleeve 5, and is configured to urge the one end 21a of the propagation member 21 against the injection sleeve 5. It is composed of Thereby, the contact state between the propagation member 21 and the injection sleeve 5 can be maintained reliably by the holding member 23. Furthermore, since the holding member 23 can be attached to the sleeve holding portion that is a part of the die-casting machine 1, there is no need to separately provide a pedestal or the like for fixing the holding member 23 in a predetermined position. Since the holding member 23 is out of contact with the injection sleeve 5, even when replacing the worn injection sleeve 5, the holding member 23 can be prevented from interfering with the replacement work.

In addition, in the first embodiment, as described above, the intensity index (intensity index data 22c) of the elastic wave EW per unit time is calculated based on the output signal of the elastic wave measurement unit 8a acquired when the plunger tip 6a moves. The determination unit 8b is configured to determine the degree of wear in at least one of the injection sleeve 5 and the plunger tip 6a based on the calculated strength index. As a result, based on the change in the strength index during the movement (sliding) of the plunger tip 6a, for example, a sudden spike-like peak 42 appeared or a remarkable displacement of the baseline 43 appeared. The degree of progress of wear can be determined with high accuracy.

Further, in the first embodiment, as described above, the determination unit 8b acquires the position information PI of the plunger tip 6a when the injection drive unit 7 moves, and determines the position information PI of the elastic wave measurement unit 8a while the plunger tip 6a is moving. It is configured to estimate the wear location of the injection sleeve 5 based on the output signal and the position information PI. Thereby, it is possible to grasp where on the injection sleeve 5 wear is progressing. Therefore, useful information can be obtained for considering adjustment of the assembly angle of the injection sleeve 5 and injection drive unit 7 and optimization of injection operation control in order to suppress the progress of wear.

Further, in the first embodiment, as described above, the extraction processing section 32 is further provided for extracting the signal component corresponding to the elastic wave EW having a frequency in the ultrasonic range from the output signal of the elastic wave measuring section 8a. As a result, for example, vibrations (displacement, chatter, etc.) that occur with injection operations, vibrations that are transmitted from other parts of the die-casting machine 1, etc., have a frequency sufficiently lower than that of the ultrasonic range, so that such vibrations can be avoided. By removing the vibration component and extracting the signal component caused by the sliding between the plunger tip 6a and the injection sleeve 5, the S/N ratio of the signal component related to the determination of the wear state can be improved.

Further, in the first embodiment, as described above, the holding member 23 is attached to the sleeve holding part 40 and is provided between the bracket 24 that holds the propagation member 21, and between the bracket 24 and the propagation member 21, A biasing member 25 that biases one end 21a of the propagation member 21 against the injection sleeve 5 is included. As a result, the propagation member 21 can be stably held by the bracket 24, and the biasing member 25 urges the propagation member 21 against the bracket 24, so that the one end 21a of the propagation member 21 and the injection sleeve 5 are A contact state can be easily ensured.

In addition, in the first embodiment, as described above, the biasing member 25 is a plate disposed between the bracket 24 and the propagation member 21 in a deformed state that biases the one end 21a of the propagation member 21 toward the injection sleeve 5. It's a spring. This allows the bracket 24 to more stably hold the propagation member 21 via the relatively rigid leaf spring.

(Second embodiment)
Next, with reference to FIG. 11, the wear condition measuring section 208 of the second embodiment will be described. In the second embodiment, an example will be described in which the AE sensor 22 is attached to a bracket 224 instead of the propagation member 221, unlike the first embodiment in which the AE sensor 22 is attached to the propagation member 21. Note that the same parts as in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Bracket 224 is an example of a "second bracket" in the claims. The wear condition measuring unit 208 is an example of a "wear condition measuring device" in the claims.

The wear condition measuring section 208 includes an elastic wave measuring section 208a and a determining section 8b (see FIG. 2). The elastic wave measuring section 208a is arranged on one side of the injection sleeve 5 in the Y direction. Note that the elastic wave measurement section may be placed directly below the injection sleeve. The determination unit 8b determines the wear status of at least one of the injection sleeve 5 and the plunger tip 6a based on the output signal (intensity index data 22c (see FIG. 2)) of the elastic wave measurement unit 208a.

The elastic wave measurement unit 208a includes a propagation member 221, an AE sensor 22, a bracket 224, and an adjustment member 226.

The propagation member 221 is constituted by a rod-shaped member. For example, the propagation member 221 is made up of a bolt, and the adjustment member 226 is made of a nut that is screwed onto the bolt that is the propagation member 221. The bolt, which is the propagation member 221, has one end 21a in contact with the injection sleeve 5, and is arranged so as to extend in a direction perpendicular to the outer surface of the cylindrical injection sleeve 5.

The bracket 224 is directly attached to the sleeve holding part 40 and is configured to directly hold the propagation member 221 and bring one end 21 a of the propagation member 221 into contact with the injection sleeve 5 . The propagation member 221 is configured so that the propagation member 221 that comes into contact with the injection sleeve 5 can be biased toward the injection sleeve 5 by adjusting the screwing position of the bolt and nut that are the propagation member 221. .

Specifically, the adjustment member 226 contacts the bracket 224 from the injection sleeve 5 side, presses the bracket 224 in a direction away from the injection sleeve 5, and elastically deforms the bracket 224. As a result, the bracket 224 causes the propagation member 221 to generate an urging force toward the injection sleeve 5 due to the restoring force. By adjusting the screwing position of the adjustment member 226 (nut) with respect to the propagation member 221 (bolt), it is possible to adjust the magnitude of the biasing force of the propagation member 221.

The bracket 224 is a plate member bent into an L shape. The bracket 224 has a linear portion 224a that extends linearly along the longitudinal direction (X direction) of the injection sleeve 5, and a linear portion 224b that extends linearly in the lateral direction (Y direction) of the injection sleeve 5. The AE sensor 22 is attached to the straight portion 224a of the bracket 224. In the X direction, the AE sensor 22 is arranged closer to the straight part 224b of the straight part 224a. A bolt 27 for fixing the bracket 224 to the sleeve holding part 40 is attached to the straight part 224b.

The bracket 224 is formed such that the thickness T2 of the portion 224d on the side that holds the propagation member 221 is smaller than the thickness T1 of the portion 224c to which the AE sensor 22 is attached (T1>T2).

That is, the straight portion 224a of the bracket 224 has a thick portion 224c to which the AE sensor 22 is attached, and a thin portion 224d on the side that holds the propagation member 221. The straight portion 224b of the bracket 224 is formed to have the same thickness as the thick portion 224c to which the AE sensor 22 is attached.

For example, the thickness T2 of the thin portion 224d on the side that holds the propagation member 221 is smaller than half the thickness T1 of the thick portion 224c to which the AE sensor 22 is attached. As a specific example, the thickness T1 is 6 mm, and the thickness T2 is 1.2 mm. Therefore, the thin portion 224d on the side that holds the propagation member 221 has a shape that is more easily deformed elastically than the thick portion 224c to which the AE sensor 22 is attached.

The other configurations of the second embodiment are the same as those of the first embodiment.

(Effects of the second embodiment)
The effects of the second embodiment will be explained.

As described above, the second embodiment includes the elastic wave measuring section 208a that measures the elastic waves propagating through the injection sleeve 5 when the plunger tip 6a moves. Thereby, as in the first embodiment, wear of the plunger tip 6a and the injection sleeve 5 can be determined with high precision.

Furthermore, as described above, the second embodiment further includes the sleeve holding part 40 that is fixed to the mold holding part 3 while holding the injection sleeve 5, and the elastic wave measuring part 208a is in contact with the injection sleeve 5. A propagating member 221 having one end 21a, a bracket 224 that is attached to the sleeve holding part 40 and directly holds the propagating member 221 and brings the one end 21a of the propagating member 221 into contact with the injection sleeve 5; It includes an AE sensor 22 that measures elastic waves propagating from the injection sleeve 5 via a propagation member 221. As a result, the propagation member 221 can be directly held by the bracket 224, and the bracket 224 has multiple functions: the function of attaching to the sleeve holding part 40, the function of attaching the AE sensor 22, and the function of holding the propagation member 221. can have. Therefore, compared to the case where the propagation member is held indirectly by a bracket or the case where each of the above functions is provided separately to a plurality of members, the device configuration of the wear state measurement unit 208 can be simplified.

Further, in the second embodiment, as described above, the bracket 224 is configured such that the thickness T2 of the portion 224d on the side that holds the propagation member 221 is smaller than the thickness T1 of the portion 224c to which the AE sensor 22 is attached. is formed. As a result, the thickness T2 of the portion 224d of the bracket 224 on the side that holds the propagating member 221 from the propagating member 221 can be made relatively thin, so that the thin portion 224d of the bracket 224 is caused by elastic waves transmitted from the propagating member 221 to the bracket 224. By vibrating relatively largely, the detection accuracy of elastic waves by the AE sensor 22 can be improved.

Other effects of the second embodiment are similar to those of the first embodiment.

(Third embodiment)
Next, with reference to FIG. 12, the wear condition measuring section 308 of the third embodiment will be described. In the third embodiment, unlike the first embodiment in which the biasing member 25 is configured with a leaf spring, an example will be described in which the biasing member 325 is configured with a compression coil spring. Note that the same parts as in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The wear condition measuring unit 308 is an example of a "wear condition measuring device" in the claims.

The wear condition measuring section 308 includes an elastic wave measuring section 308a and a determining section 8b (see FIG. 2). The elastic wave measuring section 308a is arranged on one side of the injection sleeve 5 in the Y direction. Note that the elastic wave measurement section may be placed directly below the injection sleeve. The determination unit 8b determines the wear status of at least one of the injection sleeve 5 and the plunger tip 6a based on the output signal (intensity index data 22c (see FIG. 2)) of the elastic wave measurement unit 308a.

The elastic wave measurement unit 308a includes a propagation member 21, an AE sensor 22, and a holding member 323.

The holding member 323 includes a bracket 24, a biasing member 325, and an adjusting member 26.

The propagation member 21 and the bracket 24 are both members bent into an L shape. The biasing member 325 is composed of a compression coil spring. The biasing member 325 is disposed between the bracket 24 and the propagation member 21 in a compressed state that biases one end 21 a of the propagation member 21 toward the injection sleeve 5 . The biasing member 325 is attached to the bracket 24 without contacting the injection sleeve 5 by the adjustment member 26 (bolt and nut).

A predetermined maximum distance between the bracket 24 and the propagation member 21 is defined by an adjustment member 26 (bolt and nut). As the biasing member 325 expands and contracts when the elastic wave EW (see FIG. 4) is generated, the distance between the bracket 24 and the propagation member 21 changes within a range that is equal to or less than the maximum value of the predetermined separation distance.

The propagation member 21 includes a linear portion 21c that extends linearly along the longitudinal direction (X direction) of the injection sleeve 5, and a linear portion 21d that includes one end 21a and extends linearly in the lateral direction (Y direction) of the injection sleeve 5. and has. The bracket 24 includes a straight part 24a that extends linearly along the longitudinal direction (X direction) of the injection sleeve 5, and a straight part 24b that extends linearly in the lateral direction (Y direction) of the injection sleeve 5 including one end 21a. , has. The AE sensor 22 is attached to the straight portion 21c of the propagation member 21. The straight portion 21c of the propagation 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 holding part 40 is attached to the straight part 24b.

In the Y direction, the entire propagation member 21 is arranged closer to the injection sleeve 5 than the straight portion 24a of the bracket 24. The biasing member 325 is disposed between the linear portion 21c of the propagation member 21 and the linear portion 24a of the bracket 24, and is configured to expand and contract in the Y direction. In the X direction, the biasing member 325 is arranged near the one end 21a of the straight portion 21c. In the X direction, the AE sensor 22 is arranged near the other end 21b of the straight portion 21c.

The other configurations of the third embodiment are the same as those of the first embodiment.

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

In the third embodiment, as described above, the elastic wave measuring section 308a is provided that measures the elastic waves propagating through the injection sleeve 5 when the plunger tip 6a moves. Thereby, as in the first embodiment, wear of the plunger tip 6a and the injection sleeve 5 can be determined with high precision.

Further, in the third embodiment, as described above, the holding member 323 is attached to the sleeve holding part 40 and is provided between the bracket 24 that holds the propagation member 21, and between the bracket 24 and the propagation member 21, A biasing member 325 that biases one end 21a of the propagation member 21 against the injection sleeve 5 is included. As a result, the propagation member 21 can be stably held by the bracket 24, and the biasing member 325 urges the propagation member 21 against the bracket 24, so that the one end 21a of the propagation member 21 and the injection sleeve 5 are A contact state can be easily ensured.

Further, in the third embodiment, as described above, the biasing member 325 is a compression member disposed between the bracket 24 and the propagation member 21 in a compressed state that biases the one end 21a of the propagation member 21 toward the injection sleeve 5. It is a coil spring. As a result, compared to the case where a relatively rigid biasing member is interposed between the bracket 24 and the propagation member 21, it is possible to make it difficult for vibrations to be transmitted between the bracket 24 and the propagation member 21. Vibration (noise) transmitted from the sleeve holding portion 40 side of the die-casting machine 1 to which the bracket 24 is attached can be made less likely to be transmitted to the AE sensor 22 attached to the propagation member 21.

Other effects of the third embodiment are similar to those of the first embodiment.

[Modified example]
Note that the embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the embodiments described above, and further includes all changes (modifications) within the meaning and range equivalent to the claims.

For example, in the first to third embodiments described above, an example was shown in which the die-casting machine 1 was configured horizontally, but the present invention is not limited to this. In the present invention, the die casting machine may be configured vertically.

Further, in the first to third embodiments described above, the determination unit 8b is configured as a control block of software executed by the control unit 12a of the die-casting machine 1 (that is, the control unit 12a and the determination unit 8b are configured using the same hardware). Although the present invention is not limited to this example, the present invention is not limited to this example. In the present invention, the determination unit 8b may be configured as a single determination processing device (computer) including a processor that executes determination processing. The determination section 8b may be provided in the calculation unit 8d.

In particular, in the first to third embodiments described above, an example is shown in which the wear condition measuring section 8 is configured as a part of the die casting machine 1 by incorporating the determination section 8b into the control device 12 of the die casting machine 1. However, by providing the determining section 8b separately from the control device 12 of the die-casting machine 1, a wear condition measuring device independent from the die-casting machine 1 may be configured. For example, a wear condition measuring device 107 shown in FIG. 13 includes an elastic wave measuring section 8a and a determining section 8b, so that it can be used as an aftermarket measuring device for an existing die casting machine 101 that does not have a function of determining the wear condition. can be installed. The determination unit 8b may output the wear status to the control device 110 of the die-casting machine 101, or may issue a notification according to the wear status using an alarm (not shown) included in the wear status measuring device 107.

Further, in the first to third embodiments described above, an example was shown in which the wear condition measurement section 8 (see FIG. 2) separately included an amplifier unit 8c, an arithmetic unit 8d, and a determination section 8b. It is not limited to this. In the present invention, the wear condition measurement section 8 may be configured as a single device including, for example, an amplifier unit 8c, an arithmetic unit 8d, and a determination section 8b. Further, the amplifier unit 8c and the arithmetic unit 8d may be configured as a single unit.

Further, in the first to third embodiments described above, an example was shown in which the signal processing section 34 (arithmetic unit 8d) for calculating the intensity index of the elastic wave EW was provided, but the present invention is not limited to this. In the present invention, it is not necessary to provide the signal processing section 34 (arithmetic unit 8d). The determination unit 8b may determine the wear status of the sliding part SP from the output signal 22a (output voltage value) of the AE sensor 22, which is the measurement data of the elastic wave EW itself, instead of the intensity index of the elastic wave EW. .

Furthermore, in the first to third embodiments, the extraction processing unit 32 extracts the signal component corresponding to the elastic wave EW having a frequency in the ultrasonic range from the output signal 22a of the elastic wave measuring unit 8a (208a, 308a). Although an example is shown in which the following is provided, the present invention is not limited to this. In the present invention, the extraction processing section 32 may not be provided.

Further, in the first to third embodiments described above, an example was shown in which the elastic wave measuring section 8a (208a, 308a) includes the propagation member 21 and the AE sensor 22, but the present invention is not limited to this. In the present invention, it is not necessary to provide the propagation member 21 in the elastic wave measuring section 8a. Further, in the present invention, the propagation member 21 does not need to be urged against the injection sleeve 5 by the holding member 23. For example, a propagation piece having the same shape as the propagation member 21 shown in FIG. 4 may be provided on the injection sleeve 5 so as to protrude from the outer peripheral surface of the injection sleeve 5, and the AE sensor 22 may be attached to the propagation piece. Further, the AE sensor 22 may be attached to the sleeve holding section 40 that holds the injection sleeve 5. For example, in the sleeve holding part 40, the AE sensor 22 is attached to the edge of the sleeve insertion port 40c to which the injection sleeve 5 is attached, and the AE sensor 22 detects the elastic wave EW propagated to the part holding the injection sleeve 5. You may also do so.

Further, in the first to third embodiments described above, an example was shown in which the one end 21a of the propagation member 21 has a concave shape curved along the outer peripheral surface of the injection sleeve 5, but the present invention is not limited to this. One end 21a of the propagation member 21 may be a flat surface as shown in FIG. 14(A), or may be a convex curved surface as shown in FIG. 14(B).

Further, in the first to third embodiments described above, an example was shown in which the propagation member 21 contacts the side surface of the injection sleeve 5 in the Y direction, but the present invention is not limited to this. The contact position of the propagation member 21 on the injection sleeve 5 is arbitrary, and the propagation member 21 may contact the upper surface or the lower surface of the injection sleeve 5. The contact position in the X direction is also arbitrary, and the propagation member 21 may contact at a position other than the vicinity of the pouring spout 5a.

Further, in the first to third embodiments described above, an example was shown in which only one elastic wave measuring section 8a (208a, 308a) was provided, but the present invention is not limited to this. In the present invention, a plurality of elastic wave measuring sections 8a may be provided.

Further, in the first to third embodiments described above, the determination unit 8b determines the wear status of the sliding part SP from the strength index-position change data 22d of the entire injection advance process including the low-speed advance process and the high-speed advance process. However, the present invention is not limited thereto. In the present invention, the wear status may be determined from part of the data of the injection advance process. Experience has shown that wear of the injection sleeve 5 progresses more easily in the region where the plunger tip 6a moves during the high-speed advance process than in the region where the plunger tip 6a moves during the low-speed advance process. In other words, in the area where the plunger tip 6a moves in the high-speed forward process, there is a high possibility that a wear spot exceeding the threshold value will occur first. The wear condition may be determined only from the wear condition.

In the first to third embodiments described above, as an example of the method of determining the wear state by the determining section 8b, there is a method of determining the wear state based on whether the strength index exceeds a threshold value, and a method of determining the wear state based on whether or not the strength index exceeds a threshold value, and a method of determining the wear state based on whether the strength index exceeds a threshold value, Although a method of determining the wear condition by comparison with the strength index-position change data 22d (graph 41b) has been shown, the present invention is not limited to this. In the present invention, for example, the determination unit 8b may determine the wear status using a learned model created by machine learning. Specifically, the measurement data of the elastic wave measuring unit 8a (208a, 308a) is experimentally collected for each wear condition of the sliding part SP, and the collected data group for each wear condition is input as learning data. A learned model is created in advance by machine learning the process of outputting the wear status of data. The determination unit 8b may use this learned model to determine the wear status ascertained from the latest measurement data acquired from the elastic wave measurement unit 8a for each shot. The measurement data of the elastic wave EW acquired by the elastic wave measurement unit 8a is basically acquired repeatedly several thousand or tens of thousands of times as the die-casting machine 1 operates, using the same injection process operation as a unit. It is suitable for collecting and processing as learning data for machine learning.

Further, in the first to third embodiments described above, an example was shown in which the brackets 24, 224 were attached to the sleeve holding part 40, but the present invention is not limited to this. In the present invention, the bracket may be attached to other structures such as a fixed die plate of the mold holder instead of the sleeve holder.

Further, in the above embodiment, for convenience of explanation, the processing operation of the determination unit 8b has been explained using a flow-driven flowchart in which the processing is performed sequentially along the processing flow, but the present invention is not limited to this. In the present invention, the processing operation of the control unit may be performed by event-driven processing in which processing is executed on an event-by-event basis. In this case, it may be completely event-driven, or it may be a combination of event-driven and flow-driven.

1 Die-casting machine 2 Mold 3 Mold holding section 5 Injection sleeve 6a Plunger tip 7 Injection drive section 8, 208, 308 Wear condition measuring section (wear condition measuring device)
8a, 208a, 308a elastic wave measurement unit 8b determination unit 21 propagation member 21a one end 21b other end 22 AE sensor (elastic wave detection sensor)
22a, 22b Output signal 22c Intensity index data 22d Intensity index-position change data 23, 323 Holding member 24 Bracket (first bracket)
25, 325 Biasing member 32 Extraction processing section 34 Signal processing section 40 Sleeve holding section 107 Wear condition measuring device 224 Bracket (second bracket)
224c Part (where the AE sensor is attached) 224d Part (on the side that holds the propagation member) C Cavity EW Elastic wave M Molten metal PI Position information T1 Thickness (of the part where the AE sensor is attached) T2 (On the side that holds the propagation member) thickness of part

Claims (11)

a mold holding part that holds a mold having a cavity; a cylindrical injection sleeve to which molten metal is supplied; A wear condition measuring device for measuring the wear condition of the injection sleeve and the plunger tip in a die casting machine including a plunger tip that injects and an injection drive unit that moves the plunger tip forward and backward within the injection sleeve,
an elastic wave measurement unit that measures elastic waves propagating through the injection sleeve when the plunger tip moves;
A wear condition measuring device, comprising: a determination section that determines a wear condition of at least one of the injection sleeve and the plunger tip based on an output signal of the elastic wave measurement section. The elastic wave measuring section includes:
a propagation member having one end in contact with the injection sleeve and another end remote from the injection sleeve;
The wear condition measuring device according to claim 1, further comprising: an elastic wave detection sensor attached to the other end side of the propagation member and measuring an elastic wave propagating from the injection sleeve via the propagation member. a sleeve holding part that fixes the injection sleeve to the mold holding part while holding the injection sleeve;
Further comprising a holding member that holds the propagation member,
The holding member can be attached to the sleeve holding part or the mold holding part without contacting the injection sleeve, and is configured to urge the one end of the propagation member against the injection sleeve. The wear condition measuring device according to claim 2. further comprising 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 acquired when the plunger tip moves;
The determining unit is configured to determine the degree of wear in at least one of the injection sleeve and the plunger tip based on the calculated strength index. The wear condition measuring device described. The determination unit includes:
acquiring positional information of the plunger tip during movement by the injection drive unit;
Any one of claims 1 to 3, wherein a wear location of the injection sleeve is estimated based on the output signal of the elastic wave measurement unit and the position information while the plunger tip is moving. Wear condition measuring device described in section. The wear condition according to any one of claims 1 to 3, further comprising an extraction processing unit that extracts a signal component corresponding to an elastic wave having a frequency in an ultrasonic range from the output signal of the elastic wave measurement unit. Measuring device. The holding member is
a first bracket that is attached to the sleeve holding section or the mold holding section and that holds the propagation member;
The wear condition measuring device according to claim 3, further comprising a biasing member provided between the first bracket and the propagation member and biasing the one end of the propagation member toward the injection sleeve. The biasing member may be a leaf spring disposed between the first bracket and the propagation member in a deformed state that biases the one end of the propagation member toward the injection sleeve, or a leaf spring that biases the one end of the propagation member toward the injection sleeve. The wear condition measuring device according to claim 7, which is a compression coil spring disposed between the first bracket and the propagation member in a compressed state that biases the injection sleeve. further comprising a sleeve holding part that holds the injection sleeve and fixes it to the mold holding part,
The elastic wave measuring section includes:
a propagation member having one end in contact with the injection sleeve;
a second bracket that is attached to the sleeve holding part or the mold holding part, and that directly holds the propagation member and brings the one end of the propagation member into contact with the injection sleeve;
The wear condition measuring device according to claim 1, further comprising: an elastic wave detection sensor that is attached to the second bracket and measures elastic waves that propagate from the injection sleeve via the propagation member. The wear device according to claim 9, wherein the second bracket is formed so that the thickness of the portion on the side that holds the propagation member is smaller than the thickness of the portion to which the elastic wave detection sensor is attached. Situation measuring device. a mold holding part that holds a mold having a cavity;
a cylindrical injection sleeve to which molten metal is supplied;
a plunger tip that is slidably disposed within the injection sleeve and injects the molten metal supplied to the injection sleeve into the cavity;
an injection drive unit that moves the plunger tip forward and backward within the injection sleeve;
an elastic wave measurement unit that measures elastic waves propagating through the injection sleeve when the plunger tip moves;
A die-casting machine, comprising: a determining section that determines a wear condition of at least one of the injection sleeve and the plunger tip based on an output signal of the elastic wave measuring section.

Images