JPH0653380B2 - How to set molding conditions for injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a molding condition setting method for an injection molding machine, which simplifies the setting operation.

[Background and its problems]

Generally, in an injection molding machine that molds a synthetic resin material, molding conditions vary greatly depending on the size and shape of a mold, the number of products to be manufactured, and the like. Therefore, molding conditions such as multistage injection speed, shift points, multistage injection pressure, and transformation points are set in detail for each mold.

By the way, since the molding conditions are related to each other, even if only one condition element is theoretically set, the optimum molding conditions cannot be obtained. Since it affects the quality of the molded product, its theoretical setting is also difficult. Therefore, in the end, it is necessary to rely on the judgment and intuition of each operator who has abundant experience and advanced knowledge, and it takes a long time to set up by repeating trial and error, and a large amount of With material and energy loss.

As described above, the setting of molding conditions is the most obstructive factor at the time of starting the production, and an effective technical solution is required.

[Means for solving problems]

An object of the present invention is to provide a new molding condition setting method in an injection molding machine which meets the above-mentioned demand, and is achieved by the following molding condition setting method.

That is, the molding condition setting method of the injection molding machine according to the present invention,
At least the data Di such as the type, size, shape, and product quantity of the mold 2 is set to AI (Artificial Intelligence-Artificial Intelli
gence) Database related to molding conditions such as molding pattern data, molding machine performance usage data, molding material characteristic data, etc., which is input to the computer 3a and stored in the memory 4 in advance, and basic knowledge and know-how,
Based on the knowledge base such as rules, the AI computer 3
From a, the initial conditions of the molding conditions suitable for the mold 2 are deduced, and all or part of the molding conditions for the mold 2 are set as the initial conditions, and the molding is performed using the initial conditions. The final molding condition is set by diagnosing the formed product with a diagnosis program.

[Work]

 Next, the operation of the present invention will be described.

According to the molding condition setting method of the injection molding machine according to the present invention,
First, in the memory 4, a database and basic knowledge regarding molding conditions such as molding pattern data, molding machine performance usage data, molding material characteristic data, etc. for each molded product molded in the past,
A knowledge base such as know-how, rules, and a diagnostic program for pursuing defect causes is stored. Then, when setting the conditions, the data Di such as the type, dimensions, shape, and the number of products to be taken regarding the mold 2 or necessary data such as the molding material is set to AI.
Input to the computer 3a.

As a result, the AI computer 3a uses the database and knowledge base stored in the memory 4 to determine the molding conditions of the mold 2, in particular, the optimum initial conditions.
Reasoning by the reasoning function in. That is, the AI computer 3a substitutes and sets the molding conditions (initial conditions) belonging to experience and know-how.

Then, molding is performed using the molding conditions (initial conditions), the molded product is viewed, and in the case of a defective product, a diagnosis program is used for diagnosis, and the final molding condition is set through analysis of the defective product.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic block diagram of an injection molding machine capable of carrying out the method of the present invention, FIG. 2 is a block system diagram showing the method in sequence, and FIG. 3 is a configuration of an injection molding machine suitable for carrying out the method. FIG. 4 and FIG. 4 are explanatory views showing the procedure for setting molding conditions including the same method.

First, in order to facilitate understanding of the present invention, a schematic configuration of an injection molding machine that can utilize the method of the present invention will be described.

In FIG. 1, an injection molding machine indicated by reference numeral 1 as a whole is provided with a known molding machine body 1a, a mold 2 and a control system 5, and has a built-in memory 4 used for carrying out the method of the present invention.
The I computer 3a is provided. Reference numeral 6 is a keyboard for inputting required data to the AI computer 3a. In FIG. 1, peripheral devices such as a display device are omitted.

Next, referring to FIG. 3, regarding the configuration of the injection molding machine 1,
A more specific description will be given. In FIG. 3, the same parts as those in FIG. 1 are designated by the same reference numerals.

The molding machine main body 1a is an in-line screw type, and includes a heating cylinder 13 in which a screw 11 is inserted in a front portion and an injection nozzle 12 is provided in a front end. In addition, the screw 11 at the rear
Injection cylinder 15 for inserting the ram 14 connected to the rear end of the cylinder
And an oil motor 16 for rotating the ram 14.

The rear oil chamber 15a of the injection cylinder 15 is connected to a hydraulic pressure source 18 via a control device 17 including an electromagnetic proportional flow valve, an electromagnetic proportional pressure valve, an electromagnetic directional control valve, and the like. The control device 17 is controlled by a sequence controller 20 to which a predetermined setter group is connected.

On the other hand, 21 is an arithmetic processing unit, and 4 is a memory, which forms the center of the AI computer 3a. The function of the AI computer 3a has the same calculation function as that of a normal computer and also has an inference function, and infers the optimum molding conditions for the mold 2 to be molded based on the database and knowledge base. Therefore, in the memory 4, a database of molding pattern data, molding machine performance specification data, molding material characteristic data, etc. for each molded product molded in the past, and necessary basic knowledge, know-how, rules, and an expert system to be described later are constructed. A knowledge base such as a diagnostic program for pursuing the cause of failure is stored. The inference includes not only searching the most similar molding condition pattern from a past database but also making a judgment based on input data and constructing a unique molding condition required by the input data.

Further, detection information from various sensors is input to the arithmetic processing unit 21. In each sensor, 22 is a pressure sensor that detects the oil pressure in the rear oil chamber 15a of the injection cylinder 15, 23 is an internal mold pressure sensor that is attached to the cavity of the mold 2 to detect the internal mold pressure, and 24 is the forward / backward position of the screw 11. Is a position sensor that detects the position of the protrusion 25 that follows the rear end of the screw 11 with a linear encoder, a rotary encoder, a potentiometer, or the like. In addition,
The output signals of the sensors 22 to 24 are input to the arithmetic processing unit 21 via the amplifiers 26 to 28. Note that, for ease of understanding, only the sensors necessary for the embodiments are illustrated, but various sensors can be attached if necessary.

Furthermore, the above-described keyboard 6, sequence controller 20, display device 29 using a CRT, a plasma display, etc. are connected to the arithmetic processing device 21.

Next, a molding condition setting method according to the present invention will be described with reference to FIGS.

In the present embodiment, a case will be described in which the molding condition of the speed control region shown in FIG. 4D is set for the molded product having the shape shown in FIG. In addition, in FIG.
Is a product part, 42 is a gate, 43 is a runner, and 44 is a sprue.

First, data regarding the mold 2 is input to the arithmetic processing unit 21 from the keyboard 6. The data relating to the mold 2 is data such as cavity dimensions, capacity, projected area, etc., which can be known in advance, such as product types, product numbers, sprue and runner capacities, gate types, gate numbers, gate volumes, and the like. The data to be input at this time requires at least data regarding the mold, but by further inputting data regarding the injection molding machine used, the resin material used, etc., it is possible to judge whether or not molding can be performed by the injection molding machine used. The optimum molding temperature is set for the resin material used.

With this data input, the AI computer 3a searches for the optimum molding conditions for the mold 2 based on the database and knowledge base stored in the memory 4, and further executes inference.

The necessity of the inference function by the AI computer 3a in the injection molding machine is as follows. That is, the data Di relating to the mold is input from the keyboard 6 in advance, but some data relating to the mold such as the shift point (shift position) and the transformation point (transformation timing) are included in this data Di. It is difficult to input all the data related to the mold in advance. Furthermore, it is not possible to preliminarily input data relating to molding characteristics based on the combination of the molding machine body 1a and the mold 2, such as resin flow in the mold 2, characteristic changes due to behavior, and response delay. . By the way, this kind of data is conventionally supplemented by the experience and intuition of the operator. Therefore, even if the database is used, molding data with exactly the same conditions has existed in the past, and it is possible to set the conditions when selecting it as is, but in the case of the first mold, the data input from the keyboard 6 is not possible. Information is lacking and setting is impossible.

Therefore, the inference function of the AI computer 3a is used to infer an unknown part and all or part of the molding condition is set. In this case, if some part is set, trial firing is performed. Thus, the precision of the inference result is increased and the final molding conditions are set.

Next, a specific setting method will be described step by step.

As a molding condition in the speed control region as shown in FIG. 4 (d), if the injection speed of one speed and the resin capacity (measured value) are set to the minimum, the trial shot can be performed.

First, enter the data for mold 2 as described above,
Injection speeds V1 and V depending on the function of the AI computer 3a
2, V3, and the resin material measuring position S1 (= molded product volume + cushion amount) are set.

Here, the first preliminary injection is performed. In this case, the injection speed is set to a low speed at which filling is possible by referring to the injection speeds V1, V2, and V3, and the weighing position is set to about 80% of the set weighing position S1 for weighing. To do.
The reason for setting the weighing position in this manner is to prevent damage to the mold, and the short shot is started first. Further, the pressure sensor 22 continuously detects the pressure (injection pressure) of the rear oil chamber 15a of the injection cylinder 15 when the screw advances. The screw position is the position sensor 2
4, and differentiated according to the measured time and stored in the memory 4 as position data. Furthermore, the mold internal pressure sensor 23 detects the internal pressure of the cavity, and the display device 29 displays the test pressure for the screw position,
Waveform display of changes in test firing speed and mold internal pressure.

Further, it is calculated whether or not the detected value of the injection pressure is equal to the set value. In this case, if the maximum detected value has reached the set value, the speed cannot be maintained at this set pressure due to the load pressure due to in-mold flow resistance, so the set pressure is sequentially increased to a value at which the detected value does not reach the set value. . The reason why the metering position is set to about 80% of the preset value is that the metering value can be sequentially increased by a predetermined amount to reach the completion of filling, and the screw 11 strokes before the completion of filling. Prevents a sudden increase in injection pressure at the end.

The above setting is automatically executed by the arithmetic processing unit 21. By performing the test firing in this way, the accuracy of the inference is improved, and the further advanced preliminary injection condition is set.

Next, the second preliminary injection is performed to set the shift point.
Even in this preliminary injection, the sensors 22 to 24 are also similarly to the above.
Detect data by. Then, the injection pressure with respect to the screw position is displayed in a waveform as shown in FIG. 4 (a), and the injection pressure is differentiated with respect to the screw position to obtain the inclination as shown in FIG. 4 (b). This inclination changes according to the load pressure behavior, and in the mold of FIG. 4 (c), X shown in FIG. 4 (a) is used.
The inclination becomes large at the positions of 1, X2, and X3. The position X1 is the injection start point, the position X2 is the gate passage point,
Position X3 is the filling completion point. These positions X1 to X3
Is an important point in controlling the injection process.
For example, jetting occurs when the injection speed is high when passing through the gate, and burrs occur when the injection speed is high when the filling is completed. These respective positions X1 to X3 correspond to shift points (control switching points) having substantially the same pattern depending on the shape of the molded product and the shape of the resin path.

Therefore, the position X2 is the first shift point S2, the position X3 is the control switching position S4 from the speed control region to the pressure control region, and further the shift speed is surely the injection speed V3 at the position S4 in consideration of the response delay of the injection molding machine. A point is set at each position S3.

This completes the setting of the main molding conditions in the speed control area. The same can be set in the pressure control region. The operating conditions in other details are set by inputting them from the keyboard 6 if necessary, or by searching the database of the memory 4 for the most similar pattern. For example, the injection time and the cooling time from the start of injection to the completion of the gate seal can be set by calculating from the injection speed, the gate diameter, and the characteristics of the resin material, and the pressure application time in the pressure control area,
The screw rotation speed and the screw back pressure at the time of measurement can be set to similar pattern settings.

Molding is further performed under the conditions set in this way, and after confirming that each execution value substantially matches the set value, the injection time (mainly the pressure holding time) is gradually shortened and the mold pressure at that time is set to the previous value. Shorten the injection time to the point where the mold pressure drops compared to the data. Then, the injection time immediately before the drop in the mold pressure is seen is reset as the set value. The reason why the mold pressure drops is that the gate seal is not completed and the pressure escapes to the molding machine body 1a side.

The above condition setting is automatically executed according to the program in the memory 4.

Then, molding is performed under the set molding conditions, and the operator looks at the molded product and determines whether it is a non-defective product. In the case of a defective product, the cause of the defect is analyzed and the final fine adjustment is performed in accordance with the diagnostic program by the expert system constructed by the AI computer 3a to obtain a non-defective product, and the final molding condition is set, and the memory 4 is further stored. It is stored and becomes part of the database and knowledge base. In addition,
FIG. 2 shows the procedure for setting the above-mentioned molding conditions in block units.

Although the embodiments have been described in detail above, the present invention is not limited to such embodiments. For example, the molding condition is a concept that includes not only conditions necessary for actual molding but also preliminary conditions that cannot be directly used for molding.
Further, although the condition setting on the molding machine main body side has been mainly described, the present invention can be applied to the mold clamping side. Furthermore, although the in-line screw type is exemplified, the present invention can be similarly applied to other types of injection molding machines such as a plunger type. In addition, the detailed configuration, shape, procedure, method, and the like can be arbitrarily modified and implemented without departing from the scope of the present invention.

〔The invention's effect〕

As described above, according to the molding condition setting method for an injection molding machine of the present invention, at least data regarding the mold is input to the AI computer, and the optimum molding condition for the mold is based on the database regarding the molding condition and the knowledge base stored in the memory in advance. Setting all or part of the molding conditions as the initial conditions by inferring the initial conditions of 1., and molding using the initial conditions, and diagnosing the molded product by the diagnostic program to set the final molding condition. As a result, the following effects are obtained.

Main initial molding conditions and final molding conditions are automatically set by the AI computer by inputting data on molds and information on molded products, so the operator makes final fine adjustments as necessary. Only need be. Therefore, the setting work can be remarkably simplified, and the work efficiency can be dramatically improved by shortening the setting time and reducing the labor.

Since it does not rely on the intuition of the operator himself, there is no variation in settings, and it is possible to set highly accurate and accurate initial conditions and final molding conditions, which can contribute to high quality molding.

Wasteful materials and energy loss associated with setting work can be significantly reduced, which contributes to cost reduction.

[Brief description of drawings]

1 is a schematic block diagram of an injection molding machine capable of carrying out the method of the present invention, FIG. 2 is a block system diagram showing the method in sequence, and FIG. 3 is an injection molding machine suitable for carrying out the method. Configuration diagram, FIG. 4: Explanatory diagram showing a procedure for setting molding conditions including the same method. In the drawings, 1: injection molding machine, 2: mold 3a: AI computer, 4: memory, Di: data related to mold.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Nakazawa 2110 Nanjo, Nanjo, Osaka, Hanasashi-gun, Hanashina-gun Nissei Plastic Industry Co., Ltd. (72) Inventor, Yoshitoshi Yamaki 2110, Nanjo, Hanaki-gun, Hanashina-gun, Nagano Seiseki Jushi Kogyo Co., Ltd. (72) Inventor Takahito Shioiri 2110, Nanjo, Osaka, Hanashina-gun, Nagano Prefecture Nissei Seiseki Kogyo Co., Ltd. (72) Michihiro Tatsuno, Saijo-machi, Hanashina-gun, Nagano 2110, Nanjo, Japan Kogyo Co., Ltd. (56) Reference JP-A-61-5314 (JP, A) JP-A-61-248722 (JP, A) "Plastic molding processing and computer" edited by Japan Vinyl Industry Association (Industrial Research Association) , Issued July 1, 1982) P. 22-23

Claims (1)

[Claims] 1. A molding pattern data, molding data for each molded product, which has been molded in the past, is stored in advance in a memory 4 by inputting at least data such as the type, size, shape, and product quantity of the mold 2 into an AI computer 3a. Based on a database of molding conditions such as machine performance usage data and molding material characteristic data, and a knowledge base of basic knowledge, know-how, rules, etc.
The AI computer 3a infers initial conditions of molding conditions suitable for the mold 2, sets all or part of the molding conditions for the mold 2 as initial conditions, and molds using the initial conditions. A molding condition setting method for an injection molding machine, comprising diagnosing a molded product according to a diagnostic program and setting final molding conditions.