Judgment Device and Judgment Method

Abstract

Early detection of poor sliding is carried out to prevent breakage of the mold. A judgment device (1) judges the positions of movable parts (321, 341) related to the molding operation of an injection molding device (2). The judgment device (1) includes: a vacuum pressure measurement unit (112) that measures the vacuum pressure after evacuation between a movable part to be detected and a contact part (314, 342), wherein the movable part contacts the contact part (314, 342) when located at a specified position; and a position judgment unit (113) that judges the position of the movable part based on the vacuum pressure measured by the vacuum pressure measurement unit.

Description

Technical Field

[0001] The present invention relates to a determination device and a determination method for determining the position of an ejector plate or the like of a mold of an injection molding device. Background Art

[0002] When continuously using the mold of an injection molding device, abnormal wear, i.e., "scuffing", may occur on the sliding surfaces of ejector pins, ejector sleeves, etc. If the wear of the sliding surface intensifies and scuffing occurs, it may cause fatal damage to the cavity and core that cannot be repaired, thereby damaging the expensive mold. Therefore, it is necessary to detect the abnormality of the sliding surface as early as possible before scuffing occurs and perform treatment when it can still be repaired.

[0003] For example, in the technique disclosed in Patent Document 1 below, in order to prevent foreign matter from being caught between the parting surfaces of the mold and damaging the mold, a sealed exhaust passage is formed between the parting surfaces and evacuated.

[0004] In addition, in the technique disclosed in Patent Document 2, in order to prevent damage to the mold, the forward limit points of the protruding plate (ejector plate) in the mold are set.

[0005] In addition, in the technique disclosed in Patent Document 3, in order to prevent poor molding caused by air and gas in the mold, the inside of the surrounding wall-shaped spacer is always evacuated (vacuumed) to form a vacuum chamber, thereby effectively evacuating the cavity part.

[0006] (Patent Document)

[0007] Patent Document 1: Japanese Patent Laid-Open No. 11-070545

[0008] Patent Document 2: Japanese Patent No. 3228779

[0009] Patent Document 3: Japanese Patent Laid-Open No. 2009-166284 Summary of the Invention

[0010] (Problems to be Solved by the Invention)

[0011] However, the technique described in Patent Document 1 above cannot prevent the following situation: due to a sliding failure, the ejector pin protrudes or the like, thereby damaging the mold during mold clamping. In addition, the technique described in Patent Document 2 aims to prevent operator's operation errors and does not address the situation where the position of the ejector plate is abnormal due to a sliding failure. In addition, the technique described in Patent Document 3 evacuates the inside of the cavity part in order to prevent poor molding caused by air and gas in the mold, but cannot detect the sliding failure of the mold.

[0012] One aspect of the present invention is made in view of the above problems, and an object thereof is to provide a determination device and a determination method that can detect a sliding failure in advance and prevent damage to the mold.

[0013] (Means for solving the problem)

[0014] To solve the above problems, a determination device according to one aspect of the present invention determines the position of a movable part related to the molding operation of an injection molding device. The determination device includes: a vacuum pressure measurement unit that measures the vacuum pressure after evacuation between the movable part to be detected and an abutting part, wherein the movable part abuts against the abutting part when located at a specified position; and a position determination unit that determines the position of the movable part based on the vacuum pressure measured by the vacuum pressure measurement unit.

[0015] In addition, to solve the above problems, a determination method according to one aspect of the present invention determines the position of a movable part related to the molding operation of an injection molding device. The determination method includes: a vacuum pressure measurement step of measuring the vacuum pressure after evacuation between the movable part to be detected and an abutting part, wherein the movable part abuts against the abutting part when located at a specified position; and a position determination step of determining the position of the movable part based on the vacuum pressure measured in the vacuum pressure measurement step.

[0016] (Effects of the invention)

[0017] According to one aspect of the present invention, poor sliding can be detected in advance, thereby preventing damage to the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. is a block diagram showing an example of the main part of the determination device according to Embodiment 1 of the present invention.

[0019] Figure 2 is for Figure 1 An example of the state when the mold involved is opened to take out the molded product.

[0020] Figure 3 is Figure 1 An example of the state when a sliding failure occurs in the mold involved.

[0021] Figure 4 is Figure 2 An example of a structural diagram of the exhaust hole of the mold shown.

[0022] Figure 5 FIG. is an example of an external view of the dual measurement path type determination device according to Embodiment 1 of the present invention.

[0023] Figure 6 FIG. is an example of an external view of the triple measurement path type determination device according to Embodiment 1 of the present invention.

[0024] Figure 7 is Figure 1 An example of a flowchart of a process executed by the determination device control unit shown.

[0025] Figure 8 The table shows the performance of the determination device according to Embodiment 1 of the present invention by comparison with the prior art.

[0026] Figure 9 The figure shows the performance of the determination device according to Embodiment 1 of the present invention by comparison with the prior art.

[0027] Figure 10 This is an example of the state when the mold according to Embodiment 2 of the present invention is opened and the molded product is taken out.

[0028] Figure 11 This is Figure 10 an example of the state when the mold shown is closed.

[0029] Figure 12 This is Figure 10 an example of the state when the mold shown has a sliding failure.

[0030] Figure 13 This is Figure 10 another example of the state when the mold shown has a sliding failure.

[0031] Figure 14 This is Figure 10 another example of the state when the mold shown has a sliding failure.

[0032] Figure 15 This is Figure 10 another example of the state when the mold shown has a sliding failure.

[0033] <Explanation of Reference Numerals>

[0034] 1 Determination device

[0035] 2 Injection molding device

[0036] 112 Vacuum pressure measurement unit

[0037] 113 Position determination unit

[0038] 314 Movable side mounting plate (contact member)

[0039] 317 Molded product

[0040] 321 Ejector plate (movable member)

[0041] 331 Vent hole (first hole)

[0042] 341 Slide core (movable member)

[0043] 342 Base (contact member)

[0044] 346a First through-hole (third hole)

[0045] 346b Second through-hole (second hole). Detailed implementation mode

[0046] 〔Embodiment 1〕

[0047] Hereinafter, an embodiment of one aspect of the present invention will be described with reference to the accompanying drawings. Hereinafter, an example in which the present invention is used to detect the position of the ejector plate of a mold will be described, but the solution of the present invention described in this specification can be applied to various manufacturing devices and products that use vacuum pressure to detect positions in addition to molds.

[0048] <Outline of the mold>

[0049] Figure 2 This is an example of the state when the mold 3 in Embodiment 1 of the present invention is opened and the molded product 317 is taken out. As Figure 2 shown, the mold 3 includes: a fixed-side template (cavity plate) 311, a fixed-side mounting plate 312, a movable-side template (core plate) 313, a movable-side mounting plate (abutment member) 314, and an ejection mechanism 32. In addition, the mold 3 is connected to the vacuum generating unit 12 via a pipe 334, and the pipe 334 is connected to a measurement opening 333 formed in the movable-side mounting plate 314. The measurement opening 333 will be described in detail with reference to Figure 4 to be described in detail.

[0050] The fixed-side template 311 is mounted on an unillustrated injection molding device of the injection molding device 2 via the fixed-side mounting plate 312. The inside of the fixed-side template 311 and the inside of the fixed-side mounting plate 312 are communicated by a pipe section 316. The molding material including molten resin and the like injected from the injection molding device is supplied to the cavity portion 318 described later via the pipe section 316.

[0051] The movable-side template 313 is mounted on the movable-side mounting plate 314 via a spacer block 315. The movable-side template 313 is disposed opposite to the fixed-side template 311. When the mold is closed, a drive device (not shown) moves the movable-side template 313 in a direction approaching the fixed-side template 311. At this time, the surface 313a of the movable-side template 313 opposite to the fixed-side template 311 abuts against the surface 311a of the fixed-side template 311 opposite to the movable-side template 313.

[0052] Thereby, a cavity portion 318 is formed in the gap between the movable-side template 313 and the fixed-side template 311. As described above, the molding material is supplied into the cavity portion 318 from the injection molding device, and then the molding material cools and is molded into the shape of the inner surface of the cavity portion 318, thereby generating the molded product 317.

[0053] Then, the driving device moves the movable side platen 313 away from the fixed side platen 311 to open the mold. At this time, the ejector mechanism 32 pushes the molded product 317 away from the surface of the movable side platen 313, demolds it from the mold 3 and takes it out.

[0054] The ejector mechanism 32 includes an ejector plate (movable component) 321, an ejector rod 322, an ejector pin sleeve 323, an ejector core pin 324, a reset pin 325, and a servo motor (not shown). The ejector plate 321 includes an upper ejector plate 321a and a lower ejector plate 321b. Except when the molded product 317 is removed, the ejector plate 321 is located in a position where the lower ejector plate 321b and the movable side mounting plate 314 abut against each other (hereinafter referred to as the "normal position").

[0055] The ejector pin sleeve 323 and the reset pin 325 are mounted on the ejector plate 321 and are respectively inserted into the through holes formed in the movable side template 313. The ejector pin sleeve 323 and the reset pin 325 can slide in the through hole of the movable side template 313 in conjunction with the movement of the ejector plate 321 described later.

[0056] The ejector plate 321 is connected to the servo motor via the ejector rod 322. When the mold is opened, as described above, the ejector plate 321 moves toward the movable side mold plate 313. As a result, the front end of the ejector pin sleeve 323 mounted on the ejector plate 321 protrudes from the surface of the movable side mold plate 313, so that the molded product 317 attached to the surface of the movable side mold plate 313 can be ejected and taken out.

[0057] After the molded product 317 is taken out, the mold 3 is closed again to produce the next molded product 317. At this time, the force of the spring 326 installed on the reset pin 325 resets the ejector plate 321 to the normal position. The ejector pin sleeve 323 installed on the ejector plate 321 is also reset in conjunction with the ejector plate 321, so that the front end of the ejector pin sleeve 323 is again accommodated in the through hole of the movable side template 313. Therefore, even if the mold 3 is closed, the front end of the ejector pin sleeve 323 will not collide with the cavity portion 318 of the fixed side template 311, and the cavity portion 318 will not be damaged.

[0058] After the mold 3 is closed again, in order to produce the next molded product, the molding material is injected from the injection device into the cavity portion 318. In this way, the injection molding device 2 repeatedly performs the following molding cycle: mold closing, injection, cooling, mold opening, removal, etc.

[0059] <Abnormal wear of sliding surface>

[0060] Next, the ejection mechanism 32 will be described in more detail. The ejection pin sleeve 323 is substantially cylindrical, and a through hole for inserting the ejection core pin 324 is formed inside the ejection pin sleeve 323 over the entire length.

[0061] The base end of the ejector core pin 324 is fixed to the movable side mounting plate 314, so it does not move in conjunction with the movement of the ejector plate 321 like the ejector pin sleeve 323 mounted on the ejector plate 321. Therefore, when the ejector pin sleeve 323 moves in conjunction with the movement of the ejector plate 321, the inner peripheral surface of the ejector pin sleeve 323 slides on the outer peripheral surface of the fixed ejector core pin 324. As a result, the sliding surface between the ejector pin sleeve 323 and the ejector core pin 324 is particularly prone to abnormal wear.

[0062] More specifically, there is a small gap in the sliding part between the ejector pin sleeve 323 and the ejector core pin 324, and abnormal wear is more likely to occur if the position of the ejector pin sleeve 323 or the ejector core pin 324 is slightly misaligned. In addition, the gas generated by the molding material including the high-temperature molten resin may cause attachments to the ejector pin sleeve 323 and the ejector core pin 324, or thermal expansion may cause excessive collision or partial contact (partial contact) between the sliding surfaces, which may easily cause abnormal wear.

[0063] Even if the ejector pin does not have a sleeve mechanism, abnormal wear may occur on the sliding surface between the ejector pin and the movable side mold plate 313. In addition, without being limited to this, abnormal wear may occur on the sliding surface of the mold 3.

[0064] Figure 3 This is an example of a state when a sliding failure occurs in the mold 3 in the first embodiment of the present invention.

[0065] like Figure 3 As shown, for example, if the sliding surface between the ejector pin sleeve 323 and the ejector core pin 324 is abnormally worn, sliding resistance is generated between the ejector pin sleeve 323 and the ejector core pin 324, making it difficult to slide. Therefore, when the mold is closed, the force of the spring 326 installed on the reset pin 325 cannot reset the ejector plate 321 to the normal position.

[0066] Therefore, the length of the front end of the ejector needle sleeve 323 protruding from the surface of the movable side template 313 is the length of the part of the ejector plate 321 that is not completely reset, that is, the length difference W1 between the actual reset position and the normal position.

[0067] If the mold 3 is closed in this state, the front end of the protruding ejector pin sleeve 323 collides with the cavity portion 318 of the fixed side mold plate 311, thereby damaging the cavity portion 318. In addition, if the reset pin 325 is not completely reset due to sliding resistance, the reset pin 325 also collides with the fixed side mold plate 311, thereby damaging the fixed side mold plate 311 having the cavity portion 318.

[0068] <Device Structure>

[0069] Figure 1This is a structural block diagram of an example of the main part of the determination device 1 according to Embodiment 1 of the present invention.

[0070] The determination device 1 determines the degree of reset of the ejector plate 321 based on the vacuum pressure after evacuating the space between the ejector plate 321 and the movable-side mounting plate 314. Even if the above length W1 is a minute value (for example, 0.04 mm, etc.), the determination device 1 can perform measurement with high precision. Thereby, it is possible to detect a sliding failure of the mold 3 in advance, and thus prevent breakage of the mold 3.

[0071] As Figure 1 shown, the determination device 1 includes: a determination device control unit 11, a vacuum generation unit 12, a vacuum gauge 13, a display unit 14 for displaying various information, and an abnormality notification unit 15 for notifying a user that an abnormality has occurred in case of an abnormality. The abnormality notification unit 15 includes: a speaker for outputting voice and alarm sounds, an LED for notifying an abnormality by flashing lights, an indicator, etc.

[0072] The determination device 1 may not include the abnormality notification unit 15. In addition, the vacuum generation unit 12 may be provided separately outside the determination device 1.

[0073] The determination device control unit 11 comprehensively controls each part of the determination device 1. The vacuum generation unit 12 evacuates the space between the ejector plate 321 and the movable-side mounting plate 314, and the vacuum gauge 13 measures the vacuum pressure.

[0074] The determination device control unit 11 includes: a vacuum generation unit control unit 111, a vacuum pressure measurement unit 112, a position determination unit 113, an abnormality notification control unit 114, and a display control unit 115.

[0075] The vacuum generation unit control unit 111 controls the vacuum generation unit 12 to always evacuate during the operation of the injection molding device 2. In addition, the vacuum generation unit control unit 111 may evacuate only when the vacuum pressure measurement unit 112 measures the vacuum pressure. In addition, the determination device 1 may further include a changeover switch or the like, so as to switch whether to evacuate at an arbitrary timing.

[0076] When the ejector plate 321 is reset to the normal position or the position closest to the movable-side mounting plate 314, the vacuum pressure measurement unit 112 measures the vacuum pressure between the ejector plate 321 and the movable-side mounting plate 314. The vacuum pressure measurement unit 112 detects the reset of the ejector plate 321 based on a signal issued by an encoder, and this encoder is installed in a servo motor for driving the ejector plate 321. The determination device control unit 11 displays the measured vacuum pressure on the display unit 14 via the display control unit 115.

[0077] The position determination unit 113 determines the degree of reset of the ejector plate 321 based on the vacuum pressure measured by the vacuum pressure measurement unit 112.

[0078] As Figure 2 and Figure 3 shown, an exhaust hole (first hole) 331 is formed in the movable-side mounting plate 314. The exhaust hole 331 has one opening 332 and another opening, namely a measurement opening 333. The opening 332 is located on the surface of the movable-side mounting plate 314 facing the ejector plate 321, and the measurement opening 333 is connected to a pipe 334 for discharging gas to the vacuum generating section 12.

[0079] The exhaust hole 331 may also be formed on the ejector plate 321 side. In this case, the ejector plate 321 has one opening 332 on its surface facing the movable-side mounting plate 314, thereby forming another opening, namely a measurement opening 333, which is connected to the pipe 334 for discharging gas to the vacuum generating section 12, and the exhaust hole 331.

[0080] When the ejector plate 321 is in the normal position, the opening 332 is blocked by the ejector plate 321, so the degree of vacuum is relatively high. The degree of vacuum indicates the degree of vacuum, and the higher the degree of vacuum, the closer it is to a vacuum. On the other hand, when the ejector plate 321 cannot be fully reset to the normal position due to sliding resistance and does not abut against the movable-side mounting plate 314, a gap is generated between the ejector plate 321 and the movable-side mounting plate 314, resulting in a decrease in the degree of vacuum.

[0081] If the degree of vacuum measured by the vacuum pressure measurement section 112 is lower than a specified value, the position determination section 113 determines that the position of the ejector plate 321 is abnormal. For example, if the vacuum pressure when the ejector plate 321 is in the normal position is -70 kPa, a threshold value (specified value) is set to -65 kPa in advance. If the degree of vacuum is lower than the threshold value of -65 kPa, the position determination section 113 determines it as abnormal.

[0082] In addition, the mold control section 30 includes: a servo motor control section 301 that controls a servo motor for moving the ejector plate 321; and a drive device control section 302 that moves the movable-side mounting plate 314 to control mold closing and mold opening.

[0083] After the position determination section 113 determines that the position of the ejector plate 321 is abnormal, the position determination section 113 notifies the abnormality notification control section 114 of this position abnormality. The received abnormality notification control section 114 notifies the drive device control section 302 of the mold control section 30 that an abnormality has occurred, and the drive device control section 302 stops the mold closing operation.

[0084] Thereby, it is possible to detect a sliding failure of the mold 3 in advance, stop the operation of the mold 3, and repair the mold 3 before the mold 3 is damaged.

[0085] The abnormality notification control unit 114 can cause the display unit 14 to display that an abnormality has occurred via the display control unit 115. In addition, the abnormality notification control unit 114 can notify the user that an abnormality has occurred via the abnormality notification unit 15 by voice, alarm sound, LED blinking, indicator, etc.

[0086] <Measurement opening part>

[0087] Figure 4 Yes Figure 2 And Figure 3 It is an example structure diagram of the exhaust hole 331 of the mold 3 shown.

[0088] Figure 4 The central small figure is a rear view of the mold 3 observed from the movable side mounting plate 314 side, Figure 4 The left small figure and the right small figure are side views with a part of the mold 3 cut off.

[0089] As Figure 4 Shown, two exhaust holes 331a, 331b are respectively formed on both side surfaces of the movable side mounting plate 314. The two exhaust holes 331a, 331b each have an opening 332a, 332b on the surface facing the ejector plate 321, and also each have another opening, that is, a measurement opening 333a, 333b, which is connected to the pipe 334 for discharging gas to the vacuum generating unit 12.

[0090] In the following description, when the openings 332a, 332b, etc. are not distinguished and are described in a collective name, they are collectively described as the opening 332. The measurement opening 333 and the exhaust hole 331 are also described in the same way.

[0091] The measurement openings 333a, 333b are respectively connected to the judgment device 1 via the pipes 334. In addition, the exhaust holes 331a, 331b are independently formed and do not connect or cross each other, so they do not share the measurement openings 333a, 333b and the openings 332a, 332b.

[0092] Thereby, the vacuum pressure can be measured more accurately through each measurement opening 333a, 333b.

[0093] However, it is not limited to this. The exhaust holes 331a, 331b may also have a structure that connects and crosses each other, and may also share the measurement openings 333a, 333b and the openings 332a, 332b.

[0094] In addition, the measurement openings 333a, 333b are formed in a manner that the upper and lower positions are staggered. Specifically, the measurement opening 333a is formed slightly above in the movable side mounting plate 314, and the measurement opening 333b is formed slightly below.

[0095] Thus, even if there are bending and deformation between the ejector plate 321 and the movable-side mounting plate 314 that are in contact with each other, by staggering the measurement positions, the overall condition can be grasped more accurately.

[0096] The exhaust hole 331 is, for example, basically bent in an L shape. The structure of the exhaust hole 331 is as follows: First, starting from the measurement opening 333, a first-stage hole is formed in a direction substantially perpendicular to the side surface of the movable-side mounting plate 314; then, starting from this first-stage hole, it is bent substantially at a right angle in a direction approaching the ejector plate 321, and an opening 332 is formed on the surface facing the ejector plate 321.

[0097] The exhaust hole 331 only needs to enable the measurement opening 333 and the opening 332 to communicate, and is not limited to being basically L-shaped.

[0098] Figure 4 In the example shown, an example where the number of measurement openings 333 is 2 is described, but it is not limited to this. Depending on the size and shape of the mold 3, the number of measurement openings 333 can be 1 or more than 3.

[0099] Thus, in molds 3 of different shapes and sizes, an appropriate number of measurement openings 333 and the like can be provided at appropriate positions respectively, so that the vacuum pressure can be measured more accurately for each mold 3.

[0100] <Appearance of the Judgment Device>

[0101] Figure 5 It is an example of the external view of the dual-measurement-path judgment device 1 according to Embodiment 1 of the present invention. Figure 6 It is an example of the external view of the triple-measurement-path judgment device 1 according to Embodiment 1 of the present invention.

[0102] Figure 5 The shown judgment device 1 is provided with two display units 14 and can monitor the vacuum pressure at two places simultaneously. In addition, Figure 6 The shown judgment device 1 is provided with three display units 14 and can monitor the vacuum pressure at three places simultaneously.

[0103] In addition, the display unit 14 can display that an abnormality has occurred when an abnormality occurs. The judgment device 1 may also be provided with various indicators, LEDs, etc. for notifying an abnormality other than the above-mentioned display unit.

[0104] <Processing Flow>

[0105] Based on Figure 7 , an example of the processing flow of the judgment device control unit 11 will be described. Figure 7 It is Figure 1 An example of the flowchart of the processing executed by the shown judgment device control unit 11.

[0106] First, the molding cycle of the injection molding device 2 starts, and the vacuum generating unit control unit 111 controls the vacuum generating unit 12 to always evacuate during the operation of the injection molding device 2 (S1). Additionally, the vacuum generating unit control unit 111 can also control the vacuum generating unit 12 to evacuate only when the vacuum pressure measurement unit 112 measures the vacuum pressure. Moreover, the vacuum generating unit 12 can be controlled to evacuate when an operation of a changeover switch for switching whether to evacuate is detected.

[0107] The mold control unit 30 controls the operation of the mold 3 to perform mold clamping, filling of the molding material, mold opening, and removal of the molded product 317 (S2).

[0108] After the molded product 317 is removed, the vacuum pressure measurement unit 112 determines whether the ejector plate 321 has been reset (S3). If the vacuum pressure measurement unit 112 determines that the ejector plate 321 has been reset (S3 is YES), then the vacuum pressure measurement unit 112 measures the vacuum pressure (S4: vacuum pressure measurement step).

[0109] On the other hand, if it is determined that it has not been reset (S3 is NO), then the vacuum pressure measurement unit 112 stands by until the ejector plate 321 is reset.

[0110] Regarding the vacuum pressure measured by the vacuum pressure measurement unit 112, the position determination unit 113 determines whether its degree of vacuum is higher than a threshold value (S5). If it is determined that the degree of vacuum is higher than the threshold value, then the position determination unit 113 determines that there is no abnormality (S5 is YES: position determination step), and then proceeds to the next cycle (S6), so that the mold control unit 30 controls the mold clamping, filling of the molding material, mold opening, and removal of the molded product 317 again (S2).

[0111] On the other hand, if it is determined that the degree of vacuum is lower than the threshold value, then the position determination unit 113 determines that there is an abnormality (S5 is NO: position determination step), and notifies the abnormality notification control unit 114. Then, the abnormality notification control unit 114 sends a stop signal to the drive device control unit 302 of the mold 3, the mold 3 stops operating (S8), and the process stops.

[0112] Thereby, it is possible to detect a sliding failure of the mold 3 in advance, stop the operation of the mold 3, and thus repair the mold 3 before the mold 3 is damaged.

[0113] <Performance>

[0114] Figure 8 The table shows the performance of the determination device 1 according to the first embodiment of the present invention by comparison with the conventional technology.

[0115] In the conventional technology, limit switches, proximity switches, cameras, etc. are used to judge the reset degree of the ejector plate 321. Limit switches are superior in environmental resistance such as temperature resistance and vibration resistance. Proximity switches detect the approach of an object non - contactingly. Cameras judge whether the ejector pins etc. protrude through images of the parting surface etc.

[0116] As Figure 8 shown, the limit switch has a low cost and superior heat - resistant performance, about 400 °C, but its measurement accuracy is lower than that of other devices, about 1.0 mm. The proximity switch has a higher measurement accuracy, about 0.5 mm, but its heat - resistant performance is lower, about 150 °C. Since the mold 3 uses molten resin etc. as the molding material, the molding material will cause the temperature inside the mold 3 to be very high. In this case, the proximity switch cannot be used. Compared with other devices, the camera has the highest measurement accuracy, about 0.35 mm, and also has superior heat - resistant performance, about 300 °C, but its price is very high.

[0117] Compared with other devices, the measurement accuracy of the detection by vacuum pressure adopted by the judgment device 1 is very high, about 0.04 mm, and its heat - resistant performance is also superior, about 300 °C, and the cost is not as high as that of the camera.

[0118] In summary, compared with other traditional devices, the judgment device 1 has the advantages of very high measurement accuracy, superior heat - resistant performance, and low cost.

[0119] Figure 9 The figure of Figure 9 shows the performance of the judgment device of Embodiment 1 of the present invention by comparison with the conventional technology. The figure shows the results obtained by inserting feeler gauges of various thicknesses between the ejector plate and the movable - side mounting plate of the mold to form a gap and measuring the vacuum pressure between the ejector plate and the movable - side mounting plate.

[0120] As the mold, mold A with a vacuum pressure threshold set to - 60 kPa and mold B with a threshold set to - 70 kPa are used. As described above, based on the vacuum pressure when the ejector plate is in the normal position, the vacuum pressure thresholds are set for different molds respectively.

[0121] As Figure 9 shown, it can be seen that both mold A and mold B can detect a gap distance of about 0.04 mm through the threshold, and this accuracy is much higher than the measurement accuracy of about 0.35 mm of the camera.

[0122] Thus, the judgment device 1 can very early detect the failure of the sliding surface, so that repairs can be made before the mold is damaged.

[0123] 〔Embodiment 2〕

[0124] Other embodiments of the present invention will be described below. For ease of explanation, components having the same functions as those described in the above embodiments are given the same reference numerals and will not be described again.

[0125] Figure 10 This is an example of the state when the mold 3 of Embodiment 2 of the present invention is opened and the molded product 317 is taken out. Figure 11 This is Figure 10 An example of the state when the mold 3 shown is closed. In addition, components that do not require explanation are omitted in the figure.

[0126] The mold 3 is different from the mold of Embodiment 1 and is used to produce a molded product 317 having an undercut shape. The undercut shape means a shape in which the molded product has holes, depressions, etc. and the molded product cannot be taken out of the mold by a normal mold opening method.

[0127] As Figure 10 and Figure 11 shown, the mold 3 includes: a fixed side template 311, a movable side template 313, an ejector plate 321, and ejector pins 345. In addition, the mold 3 further includes a pair of slide cores (movable components) 341, a pair of bases (abutment components) 342, and a pair of inclined pins 344 that are not provided in the mold of Embodiment 1.

[0128] Each of the pair of slide cores 341 has a cylindrical protrusion 341a at its front end and is placed on the placement surface of the base 342 in a slidable manner. Each of the pair of bases 342 is formed with a first through hole (third hole) 346a and a second through hole (second hole) 346b.

[0129] The slide core 341, the base 342, and the inclined pin 344 are each formed in a pair in a left-right symmetric manner and have the same structure and perform the same operation. However, hereinafter, if it is not particularly emphasized as a pair for ease of explanation, only one of the pair will be described.

[0130] The first through hole 346a has an opening 346a1 on the surface facing the slide core 341, and also has another opening, that is, a first detection opening 346a2, which is connected to the vacuum generating portion 12 through a pipe 334. The second through hole 346b has an opening 346b1 on the surface facing the slide core 341, and also has another opening, that is, a second detection opening 346b2, which is connected to the vacuum generating portion 12 through a pipe 334.

[0131] The vacuum generating portion 12 evacuates the space between the slide core 341 and the base 342.

[0132] The slide core 341 and the base 342 each have insertion holes 344a, 344b through which the inclined pin 344 is inserted.

[0133] At the time of mold clamping, a drive device (not shown) moves the movable platen 313 in a direction approaching the fixed platen 311. At this time, a pair of slide cores 341 mounted on the base 342 also move in a direction approaching the fixed platen 311 along the inclined pins 344 that are inclined, and the pair of slide cores 341 move in a direction approaching each other.

[0134] The surface 313a of the movable platen 313 facing the fixed platen 311 abuts against the surface 311a of the fixed platen 311 facing the movable platen 313, thereby forming a mold cavity portion 318 in the gap portion among the movable platen 313, the fixed platen 311, and the pair of slide cores 341.

[0135] The molding material is supplied from the injection molding device into the mold cavity portion 318 through the pipe section 316. Then, the molding material is cooled and molded into the shape of the inner surface of the mold cavity portion 318, thereby generating a molded product 317. The cylindrical protrusions 341a provided at the front ends of the slide cores 341 form cylindrical holes inside the molded product 317.

[0136] <Position determination>

[0137] In the open mold state, when the pair of slide cores 341 are at positions where they have moved in a direction away from each other along the mounting surface of the base 342 (hereinafter referred to as "open mold positions (first positions)"), the slide cores 341 block the opening portions 346a1 of the first through holes 346a. The vacuum generating portion 12 connected to the first detection opening portion 346a2 evacuates the space between the slide cores 341 and the base 342. The vacuum pressure measuring portion 112 measures the vacuum pressure after evacuation, and the position determination portion 113 determines whether the slide cores 341 are at the open mold positions based on this vacuum pressure.

[0138] In the mold clamped state, when the pair of slide cores 341 are at positions where they have moved in a direction approaching each other along the mounting surface of the base 342 (hereinafter referred to as "mold clamped positions (second positions)"), the slide cores 341 block the opening portions 346b1 of the second through holes 346b. The vacuum generating portion 12 connected to the second detection opening portion 346b2 evacuates the space between the slide cores 341 and the base 342. The vacuum pressure measuring portion 112 measures the vacuum pressure after evacuation, and the position determination portion 113 determines whether the slide cores 341 are at the mold clamped positions based on this vacuum pressure.

[0139] <Sliding failure>

[0140] Figure 12 , Figure 13 , Figure 14 and Figure 15 is Figure 10 An explanatory diagram of an example state when a sliding failure occurs in the mold 3 shown.

[0141] Figure 12 An example is that after taking out the molded product 317, due to abnormal wear of the sliding surface, the ejector plate 321 fails to return to its original position, and the protruding ejector pin 345 damages the front end of the slide core 341.

[0142] Figure 12 In this case, by implementing the method of evacuating the space between the movable-side mounting plate 314 and the ejector plate 321 as shown in the first embodiment, the position determination unit 113 can detect an abnormal position of the ejector plate 321.

[0143] Specifically, the vacuum generating unit 12 connected to the measurement opening 333 of the movable-side mounting plate 314 evacuates the space between the ejector plate 321 and the movable-side mounting plate 314, and the vacuum pressure measurement unit 112 measures the vacuum pressure at this time. Based on whether the measured vacuum degree of the vacuum pressure is lower than the threshold value, the position determination unit 113 can detect an abnormal position of the ejector plate 321.

[0144] Figure 13 An example is that when the mold is opened and the molded product 317 is taken out, due to abnormal wear of the sliding surface, the slide core 341 fails to return to the mold opening position, and when the mold is closed next time, the inclined pin 344 collides with the slide core 341, resulting in damage to the mold 3.

[0145] In this case, the vacuum generating unit 12 connected to the first detection opening 346a2 of the first through hole 346a evacuates the space between the slide core 341 and the base 342, and the vacuum pressure measurement unit 112 measures the vacuum pressure at this time. Based on whether the measured vacuum degree of the vacuum pressure is lower than the threshold value, the position determination unit 113 can detect an abnormal position of the slide core 341.

[0146] Figure 14 An example is that when the mold is closed and the molding material is injected, due to abnormal wear of the sliding surface, the slide core 341 fails to return to the mold closing position, and the positioning block 347 collides with the slide core 341, resulting in damage to the mold 3. In addition, a pressure cylinder (not shown) causes Figure 14 and Figure 15 the pair of slide cores 341 shown to move in a direction approaching each other or a direction away from each other.

[0147] In this case, the vacuum generating unit 12 connected to the second detection opening 346b2 of the second through hole 346b evacuates the space between the slide core 341 and the base 342, and the vacuum pressure measurement unit 112 measures the vacuum pressure at this time. Based on whether the measured vacuum degree of the vacuum pressure is lower than the threshold value, the position determination unit 113 can detect an abnormal position of the slide core 341.

[0148] Figure 15An example is that when the mold is opened and the molded product 317 is taken out, due to abnormal wear of the sliding surface, the slide core 341 fails to return to the mold opening position, resulting in damage to the protrusion 341a of the slide core 341, the ejection pin 345, and the molded product 317.

[0149] In this case, the vacuum generating unit 12 connected to the first detection opening 346a2 of the first through hole 346a evacuates the space between the slide core 341 and the base 342, and the vacuum pressure measuring unit 112 measures the vacuum pressure at this time. Based on whether the degree of vacuum of the measured vacuum pressure is lower than the threshold value, the position determination unit 113 can detect an abnormal position of the slide core 341.

[0150] In this way, even for the mold 3 for molding the molded product 317 with an undercut shape, the determination device 1 can detect poor sliding in advance, thereby preventing damage to the mold 3.

[0151] In addition, as described above, the injection molding device 2 can be a vertical type that opens and closes the mold 3 in the horizontal direction, or a horizontal type that opens and closes the mold 3 in the vertical direction. In addition, as described above, it can also be a so-called double-plate type including a fixed-side template 311 and a movable-side template 313, or a so-called triple-plate type including a runner stripper plate.

[0152] (Supplementary Notes)

[0153] The present invention can be described as follows.

[0154] A determination device according to an aspect of the present invention determines the position of a movable part related to the molding operation of an injection molding device. The determination device includes: a vacuum pressure measuring unit that measures the vacuum pressure after evacuation between the movable part to be detected and the abutting part, wherein the movable part abuts against the abutting part when located at a specified position; and a position determination unit that determines the position of the movable part based on the vacuum pressure measured by the vacuum pressure measuring unit.

[0155] According to the above solution, if the movable part abuts against the abutting part, the degree of vacuum between the movable part and the abutting part is relatively high, and if not, the degree of vacuum is relatively low. Therefore, according to the above solution, the position determination unit can determine the position of the movable part based on the vacuum pressure between the movable part and the abutting part. In addition, the position determination unit can determine whether the movable part is in a position where the movable part abuts against the abutting part.

[0156] Regarding the determination device, the movable part is an ejection plate, the abutting part is a movable-side mounting plate, and after the ejection plate ejects the molded product, the position determination unit determines whether the ejection plate has been reset to a position where it abuts against the movable-side mounting plate.

[0157] According to the above solution, the position determination unit can determine whether the ejector plate has been reset to the position where it abuts against the movable-side mounting plate.

[0158] Regarding the determination device, on the surface of the movable-side mounting plate that does not face the ejector plate, or on the surface of the ejector plate that does not face the movable-side mounting plate, a first hole communicating between the ejector plate and the movable-side mounting plate may be provided.

[0159] According to the above solution, the vacuum generating unit can use the first hole to evacuate the space between the ejector plate and the movable-side mounting plate.

[0160] Regarding the determination device, after the ejector plate moves away from the movable-side mounting plate to eject the molded product, the vacuum pressure measurement unit can also measure the vacuum pressure when the ejector plate returns to the specified position.

[0161] According to the above solution, when the ejector plate is reset to the specified position, the vacuum pressure measurement unit measures the vacuum pressure between the ejector plate and the movable-side mounting plate, so that the position determination unit can appropriately determine whether the ejector plate has been reset to the specified position.

[0162] Regarding the determination device, when the ejector plate is reset to the specified position, if the vacuum degree measured by the vacuum pressure measurement unit is lower than the specified value, the position determination unit may also determine it as abnormal.

[0163] According to the above solution, if the ejector plate is not reset to the appropriate position, the position determination unit can determine it as abnormal.

[0164] Regarding the determination device, the injection molding device produces a molded product with an undercut shape, the movable part is a slide core, the abutting part is a base on which the slide core is slidably placed. When the mold is in the open state, the slide core abuts against the first position on the placement surface of the base. When the mold is in the closed state, the slide core abuts against the second position on the placement surface of the base. The position determination unit can also determine whether the slide core is in the position where it abuts against the first position when the mold is in the open state, and determine whether the slide core is in the position where it abuts against the second position when the mold is in the closed state.

[0165] According to the above solution, when the mold is in the open state or the closed state, the position determination unit can determine whether the slide core is in the appropriate position on the placement surface of the base.

[0166] Regarding the determination device, the base may have: a second hole that communicates between the base and the slide core when the mold is in the closed state; and a third hole that communicates between the base and the slide core when the mold is in the open state.

[0167] According to the above solution, the vacuum generating unit can evacuate the space between the sliding core and the mounting surface of the base using the second hole and the third hole.

[0168] Regarding the determination device, the following solution may be adopted. After evacuating the air through the second hole when the mold is in the closed state, if the degree of vacuum measured by the vacuum pressure measuring unit is lower than a specified value, the position determination unit determines it as abnormal. After evacuating the air through the third hole when the mold is in the open state, if the degree of vacuum measured by the vacuum pressure measuring unit is lower than a specified value, the position determination unit determines it as abnormal.

[0169] According to the above solution, when the mold is in the open state and when the mold is in the closed state, if the sliding core is not in the proper position, the position determination unit can determine it as abnormal.

[0170] In addition, a determination method according to an aspect of the present invention determines the position of a movable part related to the molding operation of an injection molding device. The determination method includes: a vacuum pressure measurement step of measuring the vacuum pressure after evacuating the space between a movable part to be detected and a contact part, where the movable part contacts the contact part when it is in a specified position; and a position determination step of determining the position of the movable part based on the vacuum pressure measured in the vacuum pressure measurement step.

[0171] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the specification. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

Claims

1. A judging device that judges the position of a movable part related to the molding operation of an injection molding device. This judging device includes: A vacuum pressure measurement unit that measures the vacuum pressure after evacuation between the movable part to be detected and the abutting part. Among them, This movable part abuts against the abutting part when it is in a specified position. And A position judging unit that judges the position of the movable part based on the vacuum pressure measured by the vacuum pressure measurement unit. Among them, the movable part is an ejection plate, and the abutting part is a movable-side mounting plate. After the ejection plate ejects the molded product, the position judging unit judges whether the ejection plate has been reset to the position where it abuts against the movable-side mounting plate.

2. The judging device according to claim 1, Among them, On the surface of the movable-side mounting plate that does not face the ejection plate, or on the surface of the ejection plate that does not face the movable-side mounting plate, there is a first hole that communicates between the ejection plate and the movable-side mounting plate.

3. The judging device according to claim 1 or 2, Among them, After the ejection plate moves away from the movable-side mounting plate to eject the molded product, the vacuum pressure measurement unit measures the vacuum pressure when the ejection plate returns to the specified position.

4. The judging device according to claim 3, Among them, When the ejection plate has been reset to the specified position, if the vacuum degree measured by the vacuum pressure measurement unit is lower than the specified value, the position judging unit judges it as abnormal.

5. A judging device that judges the position of a movable part related to the molding operation of an injection molding device. This judging device includes: A vacuum pressure measurement unit that measures the vacuum pressure after evacuation between the movable part to be detected and the abutting part. Among them, This movable part abuts against the abutting part when it is in a specified position. And A position judging unit that judges the position of the movable part based on the vacuum pressure measured by the vacuum pressure measurement unit. Among them, the injection molding device produces a molded product with an undercut shape. The movable part is a slide core, and the abutting part is a base on which the slide core is slidably mounted. When the mold is in an open state, the slide core abuts against the first position on the mounting surface of the base. When the mold is in a closed state, the slide core abuts against the second position on the mounting surface of the base. The position judging unit judges whether the slide core is in the position where it abuts against the first position when the mold is in an open state, and judges whether the slide core is in the position where it abuts against the second position when the mold is in a closed state.

6. The judging device according to claim 5, Among them, The base has: a second hole that communicates between the base and the slide core when the mold is in a closed state; and a third hole that communicates between the base and the slide core when the mold is in an open state.

7. The judging device according to claim 6, Among them, After evacuating through the second hole while the mold is in a closed state, if the degree of vacuum measured by the vacuum pressure measurement unit is lower than a specified value, the position determination unit determines it as abnormal. After evacuating through the third hole while the mold is in an open state, if the degree of vacuum measured by the vacuum pressure measurement unit is lower than a specified value, the position determination unit determines it as abnormal.

8. A determination method for determining the position of a movable part related to the molding operation of an injection molding device. This determination method includes: a vacuum pressure measurement step of measuring the vacuum pressure after evacuating between a movable part to be detected and an abutting part, wherein the movable part abuts against the abutting part when it is at a specified position; and a position determination step of determining the position of the movable part based on the vacuum pressure measured in the vacuum pressure measurement step. wherein the movable part is an ejector plate and the abutting part is a movable side mounting plate. In the position determination step, after the ejector plate ejects the molded product, it is determined whether the ejector plate has been reset to a position where it abuts against the movable side mounting plate.

Images