JP3549822B2 - Control method of injection molding machine and control device of injection molding machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control method for an injection molding machine and a control device for the injection molding machine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an injection molding machine for molding a disk substrate as a molded product includes an injection device, the injection device includes a heating cylinder having an injection nozzle at a front end, and a rotatable and reciprocating inside the heating cylinder. It has a screw, which is freely disposed, and an injection cylinder as a drive unit for rotating or moving the screw forward and backward. Then, in the injection step, the screw is advanced, and the resin heated and melted in the heating cylinder is injected from the injection nozzle to fill the cavity space of the mold apparatus, and in the cooling step, The resin in the cavity space is cooled and solidified to form a disk substrate. The mold device is composed of a fixed mold and a movable mold, and the movable mold is moved toward and away from the fixed mold by a mold clamping device, so that the mold device can be closed, clamped, and opened. Done.
[0003]
In the case of molding the disk substrate, it is necessary to uniformly flow the resin radially outward from the center in the cavity space. For this purpose, it is preferable to use a cold runner type one-piece mold device. However, using a one-piece mold device not only lowers the production efficiency but also increases the cost of the disk substrate. Would.
[0004]
Therefore, a hot runner type multi-cavity (2-cavity or 4-cavity) mold apparatus is provided. In the hot runner type multi-cavity mold apparatus, a plurality of cavity spaces are formed in the mold apparatus, and a heating means is provided in each runner for supplying a resin to each cavity space, and the heating means is provided. This keeps the resin in the runner in a molten state. In this case, since the molten state of the resin in the runner can be improved, the resin can be uniformly flowed radially outward from the center in each cavity space.
[0005]
By the way, when the pressure of the resin filled in the cavity space, that is, the filling pressure becomes high, stress remains in the resin after overpacking and solidification occurs, or the resin is removed from between the fixed mold and the movable mold. May leak out to form burrs or the like, resulting in defective molding of the disk substrate.
[0006]
Therefore, the oil pressure in the injection cylinder is detected, and when the detected oil pressure exceeds a threshold value, it is determined that a molding defect has occurred in the disk substrate, and the operation of the injection molding machine is stopped. ing.
[0007]
[Problems to be solved by the invention]
However, in the conventional injection molding machine, the resin injected from the injection nozzle passes through each runner and is filled in each cavity space. For example, even if the filling pressure in one cavity space becomes high, If the filling pressure in the cavity space is normal, the oil pressure in the injection cylinder may not exceed the threshold. In that case, it cannot be determined that a molding defect has occurred in the disk substrate, and the operation of the injection molding machine cannot be stopped.
[0008]
Therefore, the operation of the injection molding machine is continued as it is, and not only does a molding defect occur in the disk substrate in the cavity space where the filling pressure is increased, but also due to the influence, the molding is performed on the disk substrate in another cavity space. Failure occurs.
[0009]
The present invention solves the problems of the conventional injection molding machine, and controls an injection molding machine that can reliably determine that a molding failure has occurred when a molding failure occurs in the molding product. It is an object to provide a method and a control device for an injection molding machine.
[0010]
[Means for Solving the Problems]
Therefore, in the control method of the injection molding machine of the present invention, the resin injected from the injection nozzle is filled into a plurality of cavity spaces through a plurality of resin supply systems, and the filling of the resin filled in each cavity space is performed. Detecting the pressure, determining whether at least one of the detected filling pressures exceeds a threshold value, and determining that at least one of the detected filling pressures exceeds the threshold value in all cavity spaces. It is determined that molding failure has occurred in the molded article, and the injection process is stopped without skipping the operation of the injection molding machine and skipped to the next process.
[0011]
In another control method for an injection molding machine according to the present invention, the filling pressure is detected by a filling pressure detecting means provided on the sprue bush.
[0012]
In the control device of the injection molding machine of the present invention, a plurality of resin supply systems for filling the plurality of cavity spaces with the resin injected from the injection nozzle and a filling pressure of the resin filled in each of the cavity spaces are detected. Filling pressure detecting means, and when at least one of the detected filling pressures exceeds a threshold value, it is determined that a molding failure has occurred in a molded product molded in all the cavity spaces, and the injection molding machine A control unit that stops the injection step and skips to the next step without stopping the operation.
[0013]
In another control device for an injection molding machine according to the present invention, the filling pressure is detected by a filling pressure detecting means provided on the sprue bush.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 1 is a functional block diagram showing a control device of an injection molding machine according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a mold device according to an embodiment of the present invention, and FIG. It is a figure showing an example of pressure. In FIG. 3, time is plotted on the horizontal axis, and filling pressure is plotted on the vertical axis.
[0016]
In FIG. 2, reference numeral 11 denotes a fixed mold unit, 12 denotes a movable mold unit, 13 denotes a fixed platen, 14 denotes a fixed mold, and 15 denotes a mold for attaching the fixed mold 14 to the fixed platen 13. The stationary mold 14 includes a manifold 16, an intermediate plate 17, and a mold plate 18. Reference numeral 19 denotes a movable mold which is disposed so as to be able to advance and retreat (move in the left-right direction in FIG. 2) so as to face the fixed mold 14, and the movable mold 19 includes a receiving plate 21 and a mold plate 22. . Then, a concave portion 23 is formed at two positions of the template 22 so as to be opened on a surface facing the template 18. A mold device is constituted by the fixed mold 14 and the movable mold 19.
[0017]
A movable platen (not shown) is provided at the back (left side in FIG. 2) of the movable mold 19 so as to be able to advance and retreat, and a mold clamping device (not shown) is provided further behind the movable platen. When the movable platen is advanced and retracted by operating the mold clamping device, the movable mold 19 is similarly advanced and retracted, and the mold closing, mold clamping and mold opening of the mold device are performed. Accordingly, the cavity spaces C1 and C2 having a disk shape are formed by the concave portions 23.
[0018]
An injection device is provided behind the fixed platen 13 (to the right in FIG. 2). The injection device includes a heating cylinder provided with an injection nozzle 26 at a front end, a screw (not shown) rotatably disposed within the heating cylinder, and a reciprocatingly movable screw, and a drive for rotating and reciprocating the screw. It has an injection cylinder (not shown) as a part. Then, the screw is advanced, and the resin heated and melted in the heating cylinder is injected from the injection nozzle 26, filled in the cavity spaces C1, C2, and cooled in the cavity spaces C1, C2. By solidifying, a disk substrate as a molded product is formed.
[0019]
For this purpose, a recess 24 having a conical shape is formed in the center of the surface of the fixed platen 13 facing the injection device, and the fixed mold 14 is positioned in the recess 24 with respect to the fixed platen 13. A locating ring 25 is provided. In addition, a manifold chamber 27 is formed in the manifold 16, and a manifold 28 is disposed in the manifold chamber 27 in an insulated state. For this purpose, spacers 31 and 32 made of heat insulating material are provided between the mold mounting plate 15 and the manifold 28, and spacers 33 made of heat insulating material are provided between the intermediate plate 17 and the manifold 28. A heat insulating space is formed around it. A bush 34 is formed in the center of the manifold 28 so as to protrude rearward, and a rear end face (a right end face in FIG. 2) of the bush 34 and the injection nozzle 26 are opposed to each other. A sprue 35 is formed in the manifold 28 at the rear end face of the bush 34 and is connected to the sprue 35 and extends in a direction away from the sprue 35 (vertical direction in FIG. 2). Runners 36 and 37 are formed, and the tips of the runners 36 and 37 are bent into an “L” shape, and are opened at both ends of the manifold 28 toward the movable mold 19. The cavity spaces C1 and C2 are formed at equidistant positions around the sprue 35.
[0020]
Hot chips 41 and 42 are attached to both ends of the manifold 28, and nozzle portions 43 and 44 are formed at front ends (left ends in FIG. 2) of the hot chips 41 and 42. Further, sprue bushes 51, 52 are disposed in front of the hot chips 41, 42 (to the left in FIG. 2), and the sprue bushes 51, 52 include outer cylinders 61, 62 and inner cylinders 45, 46, respectively. . The front ends of the nozzle portions 43 and 44 and the rear ends (right ends in FIG. 2) of the inner cylinders 45 and 46 are opposed to each other. Further, chip runners 47 and 48 are formed in the hot chips 41 and 42, and cold sprues 49 and 50 are formed in the inner cylinders 45 and 46, and the runner 36, the chip runner 47 and the cold sprue 49 are communicated with each other. The runner 37, the chip runner 48 and the cold sprue 50 are communicated. The manifold 28, the hot chips 41 and 42, and the sprue bushes 51 and 52 constitute a resin supply system for filling the cavity spaces C1 and C2 with the resin injected from the injection nozzle 26.
[0021]
The front ends of the sprue bushes 51 and 52 are disposed facing the cavity spaces C1 and C2, and are opened at the front end surface (the left end surface in FIG. 2) to form dies 53 and 54. Further, inner stamper holders 55 and 56 are provided so as to surround the front ends (left ends in FIG. 2) of the sprue bushes 51 and 52. The inner stamper holders 55 and 56 are screwed with the intermediate plate 17 and the template 18 to attach the stampers 81 and 82 to the template 18.
[0022]
In order to heat the resin passing through the runners 36 and 37 and keep the resin in a molten state, a heater H1 as first heating means is disposed on the outer peripheral surface of the manifold 28. Further, in order to heat the resin passing through the chip runners 47 and 48 and maintain the molten state, the hot chip 41 is provided with a heater H2 as a second heating means, and the hot chip 42 is provided with a heater H3 as a third heating means. H3 is buried.
[0023]
On the other hand, on the movable mold 19 side, cylindrical cut punches 65, 66 are provided at portions facing the dies 53, 54 so as to be able to advance and retreat, and sprue rods 57, 58 are provided in the cut punches 65, 66. However, ejector sleeves 59 and 60 are disposed radially outward from the cut punches 65 and 66, respectively, so as to be able to advance and retreat. A drive means (not shown) for drilling holes is provided for moving the cut punches 65 and 66, and a drive means (not shown) for protrusion is provided for moving the sprue rods 57 and 58 and the ejector sleeves 59 and 60. You.
[0024]
Next, the operation of the injection molding machine when molding a disk substrate will be described.
[0025]
First, the mold clamping device is driven, and the mold is closed and clamped in the mold device, so that cavity spaces C1 and C2 are formed. Subsequently, the injection process is started in the injection device, and when the melted resin is injected from the injection nozzle 26, the resin passes through the sprue 35 and is branched into the runners 36 and 37. After passing through the runner 36, the resin passes through the chip runner 47 and the cold sprue 49, and then is filled in one cavity space C 1. The resin passing through the runner 37 passes through the chip runner 48 and the cold sprue 50. Is filled in the other cavity space C2. In this case, since the resin is heated while passing through the runners 36 and 37 and the chip runners 47 and 48, the molten state is improved. Therefore, in each of the cavity spaces C1 and C2, the resin flows evenly from the center toward the outside in the radial direction, so that the quality of the disk substrate can be improved.
[0026]
Next, the pressure holding step is started in the injection device, and the injection cylinder is driven to maintain the pressure of the resin in the cavity spaces C1 and C2 at a predetermined value. Subsequently, a cooling process is started in the mold device, and the resin in the cavity spaces C1 and C2 is cooled and solidified. Then, in the pressure-holding step or the cooling step, when the driving means for drilling is driven and the cut punches 65, 66 are advanced (moved to the right in FIG. 2), the front ends of the cut punches 65, 66 are moved. (Right end in FIG. 2) is fitted (canned) into the dies 53 and 54, and a hole is formed in the resin in the cavity spaces C1 and C2. Thus, the disk substrate is formed.
[0027]
Thereafter, as the mold apparatus is opened, the drive means for ejection is driven, and the sprue rods 57, 58 and the ejector sleeves 59, 60 are advanced, so that the disk substrate is ejected and released. Can be
[0028]
Subsequently, a measuring step is started in the injection device, the screw in the heating cylinder is rotated, and the molten resin is stored in front of the screw head. Accordingly, the screw is retracted.
[0029]
By the way, in the injection step, when the filling pressures P1 and P2 into the cavity spaces C1 and C2 increase, stress remains in the resin after overpacking and solidification, or the fixed mold 14 and the movable mold 19 The resin leaks out from the space between them to form burrs, and molding defects occur on the disk substrate.
[0030]
Therefore, filling pressure sensors 71 and 72 as filling pressure detecting means are provided on the sprue bushes 51 and 52 of the resin supply system so as to face the cold sprues 49 and 50. The pressure of the resin in the cold sprues 49, 50 is detected as the filling pressures P1, P2 into the cavity spaces C1, C2. In the present embodiment, the filling pressure sensors 71 and 72 are provided on the sprue bushes 51 and 52, and detect the pressure of the resin in the cold sprues 49 and 50 as the filling pressures P1 and P2. However, on the mold plate 18 or the mold plate 22, a filling pressure sensor is disposed facing the cavity spaces C1, C2, and the pressure of the resin in the cavity spaces C1, C2 is directly detected as the filling pressures P1, P2, Filling pressure sensors are disposed on the hot chips 41 and 42 so as to face the chip runners 47 and 48, and the pressure of the resin in the chip runners 47 and 48 is detected as the filling pressures P1 and P2. It is also possible to arrange a filling pressure sensor so as to face 36 and 37 and detect the pressure of the resin in the runners 36 and 37 as filling pressures P1 and P2.
[0031]
When the filling pressures P1 and P2 in the cavity spaces C1 and C2 are detected by the filling pressure sensors 71 and 72, a detection signal is sent to the CPU 73 as a control unit at all times or at predetermined timings. The condition satisfaction determination processing means 75 of the CPU 73 compares the filling pressures P1 and P2 with a preset threshold value P _TH, and determines at least one of the filling pressures P1 and P2 (in this embodiment, When the pressure P1) exceeds the threshold value P _TH , it is determined that the process stop condition for stopping the injection process has been satisfied. The threshold value P _TH may be fixed to a constant value, or may be set to an arbitrary value by a setting device (not shown).
[0032]
Subsequently, when it is determined that the process stop condition is satisfied, the process skip processing means 76 of the CPU 73 determines whether the filling pressures P1 and P2 have exceeded the threshold value _PTH in the cavity spaces C1 and C2 (in the present embodiment, It is determined that a molding failure has occurred in the disk substrate in the cavity space C1), and the injection step is stopped before the injection step is completed, and the process is skipped to the next step. That is, the mold is opened, and the unfinished disk substrates in each of the cavity spaces C1 and C2 are processed as defective products. Subsequently, the step skip processing means 76 starts the next step, that is, the measuring step.
[0033]
Then, when the shot in which the molding failure occurs on the disk substrate continues for a predetermined number of times, the operation stop processing means (not shown) of the CPU 73 stops the operation of the injection molding machine.
[0034]
Thus, for example, when the filling pressure P1 in one cavity space C1 increases, it is possible to reliably determine that a molding failure has occurred in the disk substrate even when the filling pressure P2 in the other cavity space C2 is normal. it can. When the operation of the injection molding machine is continued as it is, not only a molding defect occurs in the disk substrate in the cavity space C1, but also a molding defect occurs in the disk substrate in the cavity space C2 due to the influence. The injection process is stopped, and the unfinished disk substrates in each of the cavity spaces C1 and C2 are processed as defective products, so that non-defective products and defective products are not mixed.
[0035]
When the process stop condition is satisfied, the injection process is stopped. However, the operation of the injection molding machine is skipped without being stopped, and the operation of the injection molding machine can be continued. Therefore, the operation efficiency of the injection molding machine can be improved.
[0036]
FIG. 3 shows a case where the filling pressure P1 in the cavity space C1 exceeds the threshold value _PTH and the filling pressure P2 in the cavity space C2 is normal. In this case, the filling pressure P1 exceeds the threshold value _PTH . The injection process is stopped and skips to the next process.
[0037]
In the present embodiment, an example in which the present invention is applied to a hot runner type mold apparatus is described, but the present invention can also be applied to a cold runner type mold apparatus. Further, in the present embodiment, the disk substrate is molded as a molded product, but it is also possible to mold anything other than the disk substrate.
[0038]
It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.
[0039]
【The invention's effect】
As described above in detail, according to the present invention, in the control method of the injection molding machine, the resin injected from the injection nozzle is filled into a plurality of cavity spaces through a plurality of resin supply systems, and each of the cavities is filled. Detect the filling pressure of the resin to be filled into the space, determine whether at least one of the detected filling pressures exceeds a threshold, at least one of the detected filling pressures has exceeded a threshold In some cases, it is determined that a molding failure has occurred in the molded product in all the cavity spaces, and the injection process is stopped without skipping the operation of the injection molding machine and skipped to the next process.
[0040]
In this case, the filling pressure of the resin to be filled in each cavity space is detected, and when at least one of the filling pressures exceeds a threshold, a molding failure has occurred in a molded product in all cavity spaces. Is determined.
[0041]
Therefore, when the filling pressure in at least one cavity space is increased, it is possible to reliably determine that molding failure has occurred even if the filling pressure in other cavity spaces is normal. When molding failure occurs in at least one cavity space molded product, the molding process occurs in other cavity space moldings under the influence of the molding failure, but the injection process is stopped and each cavity space is not completed. Are processed as defective products, so that non-defective products and defective products are not mixed.
[0042]
Also, when it is determined that molding failure has occurred in the molded product in all the cavity spaces, the injection process is stopped without skipping the operation of the injection molding machine and skipped to the next process. The operation of the injection molding machine can be continued, and the operation efficiency of the injection molding machine can be improved.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing a control device of an injection molding machine according to an embodiment of the present invention.
FIG. 2 is a sectional view of a mold device according to the embodiment of the present invention.
FIG. 3 is a diagram showing an example of a filling pressure in the embodiment of the present invention.
[Explanation of symbols]
26 Injection nozzle 28 Manifold 41, 42 Hot tip 51, 52 Sprue bush 71, 72 Filling pressure sensor 73 CPU
C1, C2 Cavity space P _TH threshold

Claims (4)

(A) filling a plurality of cavity spaces with a resin injected from an injection nozzle through a plurality of resin supply systems;
(B) detecting the filling pressure of the resin filled in each cavity space,
(C) determining whether at least one of the detected filling pressures exceeds a threshold,
(D) When at least one of the detected filling pressures exceeds a threshold value, it is determined that molding failure has occurred in the molded product in all the cavity spaces, and the operation of the injection molding machine is stopped. A method for controlling an injection molding machine, wherein the injection step is stopped and skipped to the next step without any step . The filling pressure, the control method for an injection molding machine according to claim 1 that will be detected by the filling pressure detection means disposed sprue bushing. (A) a plurality of resin supply systems for filling the plurality of cavity spaces with the resin injected from the injection nozzle;
(B) filling pressure detecting means for detecting a filling pressure of the resin filled in each cavity space;
(C) When at least one of the detected filling pressures exceeds a threshold value, it is determined that molding failure has occurred in the molded product in all the cavity spaces, and the operation of the injection molding machine is stopped. A control unit for interrupting the injection process and skipping to the next process without any control. The filling pressure, the control apparatus for an injection molding machine according to claim 3 that will be detected by the filling pressure detection means disposed sprue bushing.

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