JP2002086495A - Method and apparatus for controlling injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly judge the generation of molding deficiency in a molded product when the molding deficiency is generated in the molded product. SOLUTION: A plurality of cavity spaces are filled with the resin, which is injected from an injection nozzle, through a plurality of resin supply systems and the filling pressures of the resin charged in the respective cavity spaces are detected to judge whether at least one of the detected filling pressures exceeds at least one of the threshold value among the respective detected filling pressures and, when at least one of the filling pressures exceeds at least one threshold value, the molding failure is judged to be generated in the molded product. When the filling pressure of the resin charged in at least one cavity space becomes high, even when the filling pressure in other cavity is normal, the generation of molding failure can be certainly judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. 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]

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 has a heating cylinder having an injection nozzle at a front end, and is rotatable in the heating cylinder. And an injection cylinder as a drive unit for rotating and reciprocating the screw, which is disposed to be able to move forward and backward. Then, in the injection step, the screw is advanced,
Injecting the resin heated and melted in the heating cylinder from the injection nozzle into the cavity space of the mold apparatus, and cooling and solidifying the resin in the cavity space in the cooling step. To form a disk substrate. The mold apparatus is composed of a fixed mold and a movable mold, and the movable mold is brought into contact with and separated from the fixed mold by a mold clamping device, so that mold closing, mold clamping and mold opening of the mold apparatus are performed. Done.

[0003] In 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.
The use of a single die apparatus not only reduces the production efficiency, but also increases the cost of the disk substrate.

Therefore, a multi-cavity hot-runner type (2
A single-piece or four-piece mold apparatus is provided. In the hot runner type multi-cavity mold device, a plurality of cavity spaces are formed in the mold device, and a heating means is provided in each runner for supplying a resin to each cavity space. This keeps the resin in the runner in a molten state. In this case, the molten state of the resin in the runner can be improved, so that 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 increases, stress remains in the resin after overpacking and solidification.
Resin leaks from between the fixed mold and the movable mold to form burrs, and molding defects occur on the disk substrate.

Therefore, the oil pressure in the injection cylinder is detected,
When the detected hydraulic pressure exceeds a threshold value, it is determined that a molding failure has occurred in the disk substrate, and the operation of the injection molding machine is stopped.

[0007]

However, in the above-described conventional injection molding machine, the resin injected from the injection nozzle passes through each runner and fills each cavity space. Even if the filling pressure increases, if the filling pressure in the other cavity space is normal, the oil pressure in the injection cylinder may not exceed the threshold. In this 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 molding failure occurs in the disk substrate in the cavity space where the filling pressure is increased, but also the disk substrate in another cavity space is affected by the influence. Also, molding failure occurs.

The present invention solves the above-mentioned problems of the conventional injection molding machine and, when a molding failure occurs in a molded product, can reliably determine that the molding failure has occurred in the molded product. An object of the present invention is to provide a control method for a molding machine and a control device for an injection molding machine.

[0010]

For this purpose, 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 each of the plurality of cavity spaces is filled with the resin. Detect the filling pressure of the resin to be filled into the cavity space, determine whether at least one of the detected filling pressures exceeds a threshold, at least one of the detected filling pressures exceeds the threshold. When
It is determined that molding failure has occurred in the molded product.

In another control method for an injection molding machine according to the present invention, when a molding failure occurs in the molded product, the injection step is stopped and the next step is skipped.

In the control apparatus for an injection molding machine according to the present invention, a plurality of resin supply systems for filling a plurality of cavity spaces with a resin injected from an injection nozzle, and a filling of the resin filled in each of the cavity spaces are provided. A filling pressure detecting means for detecting the pressure, and a control unit for judging that a molding failure has occurred in the molded article when at least one of the detected filling pressures exceeds a threshold value.

In another control apparatus for an injection molding machine according to the present invention, the control section stops the injection step and skips to the next step when a molding failure occurs in the molded product.

[0014]

Embodiments of the present invention will be described below in detail with reference to 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 apparatus according to an embodiment of the present invention, and FIG. It is a figure showing the example of the filling pressure in a form. In addition,
In FIG. 3, the horizontal axis represents time, and the vertical axis represents filling pressure.

In FIG. 2, 11 is a fixed mold unit, 12 is a movable mold unit, 13 is a fixed platen, 14 is a fixed mold, and 15 is a fixed mold 14 attached to the fixed platen 13. The fixed die 14 includes a manifold 16 and an intermediate plate 17.
And a template 18. 19 is the fixed mold 14
The movable mold 19 is provided with a receiving plate 21 and a mold plate 22 so as to be capable of moving forward and backward (moving in the left-right direction in FIG. 2). And 2 of the template 22
A concave portion 23 is formed at a location where the concave portion 23 is opened on the surface facing the template 18. A mold device is constituted by the fixed mold 14 and the movable mold 19.

A movable platen (not shown) is provided at the rear (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. You. 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. A cavity space C having a disk shape due to the recess 23
1, C2 is formed.

The rear of the fixed platen 13 (FIG. 2)
The right side of the figure) is provided with an injection device. 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 capable of moving forward and backward, and a drive for rotating and moving the screw forward and backward. An injection cylinder (not shown) is provided 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, and is filled in the cavity spaces C1 and C2.
The disk substrate as a molded product is formed by cooling and solidifying the resin in C2.

For this purpose, a recess 24 having a conical shape is formed in the center of the surface of the stationary platen 13 facing the injection device, and the recess 24 has a stationary mold with respect to the stationary platen 13. A locate ring 25 for positioning the position 14 is provided. 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 a heat insulating material are provided between the mold mounting plate 15 and the manifold 28,
Spacer 3 made of a heat insulating material between the gasket 7 and the manifold 28
3 is provided, and a heat insulating space is formed around the manifold 28. A bush 34 is formed at the center of the manifold 28 so as to protrude rearward, and the rear end face (the 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 (a 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 equal distances around the sprue 35.

At both ends of the manifold 28, hot chips 41, 42 are attached.
Nozzle portions 43 and 44 are formed at the front end of FIG. The sprue bushes 51, 5 are located forward (leftward in FIG. 2) of the hot chips 41, 42.
2 are provided, and the sprue bushes 51 and 52 include outer cylinders 61 and 62 and inner cylinders 45 and 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. Also, chip runners 47, 48 are provided in the hot chips 41, 42.
However, 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, and 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 form a resin supply system for filling the cavity spaces C1 and C2 with the resin injected from the injection nozzle 26.

The sprue bushes 51, 52
Are arranged facing the cavity spaces C1 and C2, and are opened at the front end face (the left end face in FIG. 2).
3, 54 are formed. 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
And the stamper 81, 8
2 is attached to the template 18.

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 provided on the outer peripheral surface of the manifold 28. 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.
2 embeds a heater H3 as a third heating means.

On the other hand, on the movable mold 19 side, cylindrical cut punches 65 and 66 are provided at portions opposed to the dies 53 and 54 so as to be able to advance and retreat.
Sprue rods 57 and 58 are disposed in the inside and outside of the cut punches 65 and 66, respectively, and ejector sleeves 59 and 60 are disposed inside and outside the cut punches 65 and 66, respectively. And
Driving means (not shown) for drilling holes to advance and retreat the cut punches 65 and 66 includes sprue rods 57 and 58.
In addition, a driving means (not shown) for projecting is provided for moving the ejector sleeves 59 and 60 forward and backward.

Next, the operation of the injection molding machine when molding a disk substrate will be described.

First, the mold clamping device is driven, the mold is closed and clamped in the mold device, and the cavity space C is set.
1, C2 is 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,
It is branched into runners 36 and 37. And runner 3
After passing through the chip runner 47 and the cold sprue 49, the resin is filled in one cavity space C1. After passing through the runner 37, the resin passes through the chip runner 48 and the cold sprue 50 and then the other. The cavity space C2 is filled. In this case, runner 3
Since the resin is heated while passing through the chip runners 6, 37 and the chip runners 47, 48, the molten state is improved. Therefore, in each of the cavity spaces C1 and C2, the resin flows uniformly from the center toward the radially outward direction, so that the quality of the disk substrate can be improved.

Next, the pressure holding process is started in the injection device, and the injection cylinder is driven to drive the cavity spaces C1 and C1.
The pressure of the resin in 2 is maintained at a predetermined value. Subsequently, a cooling process is started in the mold apparatus, and the cavity space C
1. The resin in 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 and 66 are moved forward (moved to the right in FIG. 2), the cut punch 6
The front ends (right ends in FIG. 2) of the die 5 and 66 are 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.

Thereafter, as the mold apparatus is opened, the drive means for projecting is driven, and when the sprue rods 57, 58 and the ejector sleeves 59, 60 are advanced, the disk substrate is ejected, It is released.

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.

By the way, in the injection step, when the filling pressures P1 and P2 into the cavity spaces C1 and C2 are increased,
Stress remains in the resin after overpacking and solidification, or resin leaks out from between the fixed mold 14 and the movable mold 19 to form burrs. Will occur.

Therefore, filling pressure sensors 71, 7 as filling pressure detecting means are provided to the sprue bushes 51, 52 of the resin supply system, facing the cold sprues 49, 50.
The pressure of the resin in the cold sprues 49 and 50 is detected by the filling pressure sensors 71 and 72 as filling pressures P1 and P2 into the cavity spaces C1 and 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, the filling pressure sensor is disposed on the mold plate 18 or the mold plate 22 so as to face the cavity spaces C1 and C2.
1, the pressure of the resin in C2 is detected as filling pressures P1, P2,
A charging pressure sensor is provided to face the nozzles 7 and 48, and the pressure of the resin in the chip runners 47 and 48 is detected as charging pressures P1 and P2, or the charging pressure is detected to the manifold 28 and the runners 36 and 37. A sensor may be provided to detect the pressure of the resin in the runners 36 and 37 as the filling pressures P1 and P2.

The filling pressures P1, P2 in the cavity spaces C1, C2 are detected by the filling pressure sensors 71, 72.
When 2 is detected, a detection signal is sent to the CPU 73 as a control unit at all times or at predetermined timing. The CP
The condition satisfaction determination processing means 75 of U73 determines that the charging pressure P
1, P2 is compared with a preset threshold value _PTH, and when at least one of the filling pressures P1 and P2 (in the present embodiment, the filling pressure P1) exceeds the threshold value _PTH ,
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).

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 P _TH and the cavity spaces C1 and C2 (the present embodiment). In the embodiment, it is determined that molding failure has occurred in the disk substrate in the cavity space C1), the injection process is stopped before the injection process is completed, and the process is skipped to the next process. That is, the mold is opened, and the unfinished disk substrates in the cavity spaces C1 and C2 are both treated as defective. Subsequently, the step skip processing means 76 starts the next step, that is, the measuring step.

When the shots in which the molding failure occurs on the disk substrate continue 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.

As described above, for example, when the filling pressure P1 in one cavity space C1 increases, even if the filling pressure P2 in the other cavity space C2 is normal,
It is possible to reliably determine that a molding defect has occurred in the disk substrate. Then, when the operation of the injection molding machine is continued as it is, not only molding failure occurs in the disk substrate in the cavity space C1 but also molding failure occurs in the disk substrate in the cavity space C2 due to the influence thereof.
The injection process is stopped, and the unfinished disk substrates in each of the cavity spaces C1 and C2 are treated as defective products, so that non-defective products and defective products are not mixed.

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. it can. Therefore, the operation efficiency of the injection molding machine can be improved.

In FIG. 3, the cavity space C
Beyond the filling pressure P1 threshold P _TH in 1, when it filling pressure P2 in cavity C2 indicates a normal case, this case, the filling pressure P1 exceeds the threshold value P _TH,
The injection process is stopped and the process skips to the next process.

In this embodiment, an example in which the present invention is applied to a hot runner type mold apparatus is described. However, the present invention can be applied to a cold runner type mold apparatus. Further, in the present embodiment, the disk substrate is formed as a molded product, but a product other than the disk substrate can be formed.

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]

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. Detecting the filling pressure of the resin filled in each cavity space, determining whether at least one of the detected filling pressures exceeds a threshold value, and determining at least one of the detected filling pressures. When one exceeds the threshold value, it is determined that molding failure has occurred in the molded product.

In this case, the filling pressure of the resin filling each cavity space is detected, and when at least one of the filling pressures exceeds a threshold value, it is determined that a molding failure has occurred in the molded product.

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 a molding failure occurs in at least one cavity space, a molding failure occurs in another cavity space due to 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.

In another control method of the injection molding machine according to the present invention, when a molding defect occurs in the molded product, the injection step is stopped and the next step is skipped.

In this case, when a molding failure occurs in the molded product, the injection process is stopped and skipped to the next process without stopping the operation of the injection molding machine, so that the operation of the injection molding machine is continued. 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 illustrating 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)

[Claims] (A) filling a plurality of cavity spaces with a resin injected from an injection nozzle through a plurality of resin supply systems; and (b) detecting a filling pressure of the resin filled in each of the cavity spaces. (C) determining whether at least one of the detected filling pressures exceeds a threshold, and (d) determining whether at least one of the detected filling pressures exceeds the threshold, A method for controlling an injection molding machine, comprising determining that molding failure has occurred. 2. The control method for an injection molding machine according to claim 1, wherein when a molding defect occurs in the molded article, the injection step is stopped and skipped to the next step. 3. A plurality of resin supply systems for filling a plurality of cavity spaces with a resin injected from an injection nozzle, and (b) detecting a filling pressure of the resin filled in each of the cavity spaces. Injection characterized by having a filling pressure detecting means and (c) a control unit for judging that a molding defect has occurred in a molded product when at least one of the detected filling pressures exceeds a threshold value. Control device for molding machine. 4. The control device for an injection molding machine according to claim 3, wherein the control unit stops the injection step and skips to the next step when a molding defect occurs in the molded product.