JP2012187787A - Method of supporting adjustment of molding condition and injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of supporting the setting of a molding condition of an injection molding machine by which reference information utilized by a worker at ease as a reference is displayed in a work for setting the molding condition.SOLUTION: Basic data related to a molded product such as the weight of a molded product, the kind of an injecting material or the like are input to a controller 20 of the injection molding machine. The controller 20 uses input basic data to calculate reference information becoming a reference when the molding condition is adjusted by four arithmetic operations. As the reference information, the stroke of a screw 6 for injecting the molded product, the specific gravity of an injection material in a molten state in a cylinder barrel 5 are described. The reference information is displayed on a display device 21 provided in the controller 20. The worker can safely perform the setting of the molding condition by referring to the reference information.

Description

  The present invention relates to a molding condition adjustment support method for providing information for assisting an operator when adjusting molding conditions in an injection molding machine, and an injection molding machine including a controller for performing such a support method. It is.

  The injection molding machine is roughly composed of an injection unit and a platen device. As is well known in the art, the injection unit is composed of a cylinder barrel and a screw provided in the cylinder barrel so as to be driven in the rotational direction and the axial direction. On the other hand, a platen device is also well known in the art, and a fixed platen to which a fixed side die is attached, a movable platen to which a movable side die is attached, and a movable side die to a fixed side die. For example, it comprises a toggle type mold clamping device that opens and closes. Therefore, when the screw is rotated and the resin material is supplied to the cylinder barrel by a predetermined amount, the resin material is melted by heat generated by friction / shearing action due to rotation of the screw, heat applied from the outer periphery of the cylinder barrel, and the like. The screw is sent to the measuring chamber at the tip of the cylinder barrel, and the screw is retracted to store a predetermined amount. The molten resin weighed in this way is injected and filled into the cavity of the mold that has been clamped by driving the screw in the axial direction, and when the movable mold is opened after cooling and solidification, molding of a predetermined shape is performed. Goods are obtained.

  By the way, the mold is manufactured for each molded product to be molded, and the shape and capacity of the cavity, the capacity of the runner, and the like are different for each mold. In addition, the type of resin is different for each molded product. Therefore, injection conditions such as injection pressure, injection speed, molten resin temperature, number of injection stages, screw position for each number of injection stages, and the like vary from mold to mold or molded product. For this reason, it is necessary to carry out so-called molding condition adjustment in which the molding conditions are repeatedly changed and injection molding is repeated to adjust appropriate molding conditions for molding good products. For example, depending on the molded product, it may be possible to obtain better products by changing the injection speed at each injection stage number and changing the injection speed at each injection stage number. Is required. The reason why the number of injection stages is set to a plurality of stages is to prevent burning caused by frictional heat when the molten resin flows through the gate at a high speed. For example, the number of injection stages is set to three and the injection speed is changed as follows. Yes. That is, in the first stage immediately after the start of injection, the injection speed is increased until just before the molten resin reaches the gate, that is, until the runner is filled to some extent. Next, in the second stage, the injection speed is lowered so that the molten resin that reaches the gate first flows slowly through the gate. Once the molten resin has flowed through the gate, the injection speed is switched to a high speed as the third stage so that the molten resin fills the cavity in a short time. If it does so, while being suppressed, generation | occurrence | production of a flow mark is also prevented and a good product is obtained. In order to carry out such an injection molding method, it is necessary to accurately determine the screw position where the molten resin is filled into the runner and the screw position where the filling of the molten resin into the cavity is completed. The former screw position is determined by repeatedly performing a test of injecting a molten resin by a small amount and searching for a position where only the runner is filled. The latter screw position is determined by looking for a position where short shots, sink marks, etc. are not formed on the molded product, but if the amount of molten resin injected is too large compared to the cavity capacity, burrs will occur As a result, expensive molds are damaged, and the molten resin to be injected is confirmed by repeated tests so as to increase carefully little by little. In this way, determining molding conditions is complicated because repeated tests must be carried out, and if the conditions are mistaken due to mistakes, there is a risk of damaging expensive molds, so careful attention is required. Yes.

JP 2008-110486 A JP 2010-042599 A

  Patent Document 1 describes a method of assisting an operator who operates an injection molding machine by predicting the quality of a molded product by a neural network from input molding conditions. According to the method described in Patent Document 1, it is possible to repeatedly perform trial molding in the target injection molding machine and the mold, and to set a plurality of molding conditions so as to obtain good products. Then, a plurality of sets of molding conditions obtained are used as input items, and the quality value of the molded product under each molding condition is used as an output item to cause the neural network to learn. If an arbitrary molding condition is input to this neural network, the quality value of the molded product can be predicted. Therefore, the quality value of the molded product can be easily predicted without actually performing an injection molding test. Therefore, even an unskilled worker can determine the molding conditions.

  In Patent Document 2, an injection molding analysis software for analyzing the flow of molten resin in injection molding and a so-called multi-purpose genetic algorithm capable of estimating an optimal solution are combined to obtain an optimal molding condition by a computer. A method is described. According to this method, when injection conditions are given in the injection molding analysis software, it is possible to virtually analyze the injection molding, and the optimal injection molding is estimated from the analyzed multiple injection moldings by a multi-purpose genetic algorithm. Therefore, molding conditions can be set efficiently without actually performing injection molding.

  According to the method described in Patent Document 1, since the quality value of a molded product with respect to an arbitrary molding condition can be predicted by a neural network, the molding condition can be easily obtained. However, there are problems. For example, in the method described in Patent Document 1, in order for the neural network to learn, it is necessary to obtain a plurality of sets of molding conditions for obtaining good products, and it is complicated because trial molding must be repeatedly performed. . Further, if a large amount of molten resin is mistakenly injected in trial molding, burrs are generated and the mold is damaged, but no special consideration is given to preventing such danger. The neural network is excellent in that it can learn with a small number of calculations and can easily predict the quality value, but the prediction is not always appropriate and the possibility that there is a problem in the predicted quality value cannot be excluded. If so, there is a possibility that problematic molding conditions may be determined, and there is a risk of damaging expensive molds.

  In the method described in Patent Document 2, molding conditions can be determined without performing trial molding, but there are other problems. Specifically, the multi-objective genetic algorithm can estimate an optimal solution by advanced processing, but there is a problem that there is no guarantee that the estimated optimal solution is necessarily appropriate. Then, when injection molding is performed under the molding conditions obtained by the method described in Patent Document 2, there is a possibility that the molten resin is excessively injected to damage the mold. In other words, safety cannot be guaranteed reliably.

  Both the method described in Patent Document 1 and the method described in Patent Document 2 are excellent because they can be calculated with a small number of operations, but they are calculated by advanced information processing and are made into a black box. It is difficult to verify whether it is appropriate. Molding condition determination is finally performed by repeating fine adjustment by an injection molding test, but if it is not possible to verify whether the calculation result is appropriate or not, it is safe. There is a risk that the molding conditions cannot be determined and the mold may be damaged.

  An object of the present invention is to provide a molding condition setting support method for an injection molding machine that solves the above-described problems, and an injection molding machine that includes a controller that performs such a support method. Specifically, reference information is provided to assist the operator in determining the molding conditions, and when calculating this reference information, there is no need to perform trial molding, and it is possible to perform a complicated process that is made into a black box. Rather than using the reference information provided by the operator, the molding conditions can be determined using the reference information provided by the operator. It is an object of the present invention to provide an injection molding machine equipped with a controller that implements such a support method.

  In order to achieve the above object, the invention according to claim 1 includes a cylinder barrel and a screw provided in the cylinder barrel so as to be capable of being driven in the rotational direction and the axial direction, and molding a predetermined molded product. In the injection molding machine to which the mold to be mounted is attached, reference information useful for determining molding conditions for adjusting molding conditions is calculated from basic data related to the molded product input to the controller of the injection molding machine, Reference information is displayed on a display device of the controller, and is configured as a method for assisting adjustment of molding conditions of an injection molding machine.

According to a second aspect of the present invention, in the method according to the first aspect, the basic data includes a type of an injection material, a runner weight that is a weight of a runner formed when the molded article is molded, The reference information includes an estimated runner stroke and an estimated molded product stroke which are estimated values of the stroke of the screw necessary to fill each of the runner and the molded product. The estimated runner stroke and the estimated molded article stroke are configured to be calculated from the basic data, the specific gravity of the injection material at normal temperature and when melted, and the inner diameter of the cylinder barrel. .
According to a third aspect of the present invention, in the method according to the first aspect, the basic data includes a weight of the molded product that is a weight of the molded product, and the reference information includes a specific gravity when the injection material is melted. The specific gravity at the time of melting of the injection material is calculated from the basic data and the volume of the molten resin material actually injected.
According to a fourth aspect of the present invention, in the method according to the first aspect, the basic data includes the weight of the molded product, which is the weight of the molded product, the type of the injection material, and the glass fiber added to the injection material. The reference information is an estimated molded product which is an estimated value of the specific gravity of the injection material melted and added with the glass fiber and the stroke of the screw necessary for molding the molded product. Specific gravity of the injection material in the state where the glass fiber is added after melting, and the estimated molded product stroke, the basic data, the specific gravity of the injection material at normal temperature and at the time of melting, It is comprised so that it may calculate from the internal diameter of a cylinder barrel.
According to a fifth aspect of the present invention, in the method according to the first aspect, the basic data includes a molded product weight that is a weight of a molded product and a type of an injection material, and the reference information includes the screw of the screw. The injection speed is an injection speed that is a speed at the time of injection, and the injection speed is configured to be calculated from the basic data and an injection time that is a time required for injection.
According to a sixth aspect of the present invention, in the method according to the first aspect, the basic data includes a molded product weight, which is a weight of a molded product, and a type of injection material, and the reference information is required for injection. The injection time is a time, and the injection time is configured to be calculated from the basic data and an injection speed that is a speed at the time of injection of the screw.
The invention described in claim 7 is configured as an injection molding machine including a controller that implements the molding condition adjustment support method according to any one of claims 1 to 6.

  As described above, according to the present invention, reference information for reference when adjusting molding conditions is calculated from basic data related to a molded product, and the reference information is displayed on a display device of a controller of an injection molding machine. Therefore, it is easy for the operator to determine the molding conditions. And when calculating such reference information, it is not necessary to perform trial molding. Since the operator can determine the molding conditions with reference to such reference information, it is possible to prevent the operator from making mistakes and to prevent erroneous molding conditions from being determined. The reference information is only provided as a reference, and the operator's judgment is always involved in determining the molding conditions. When the optimal molding conditions are determined by complicated processing that is made into a black box, there is a possibility that erroneous molding conditions may be derived due to processing defects. Since the operator's judgment is always involved, an effect unique to the present invention can be obtained in which the possibility of erroneous molding conditions being determined can be sufficiently reduced.

It is a side view which shows typically the injection molding machine which concerns on embodiment of this invention. It is a table | surface which shows the reference information calculated from various basic data for demonstrating the adjustment assistance method of the molding conditions of the injection molding machine which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below. As shown in FIG. 1, the injection molding machine 1 according to the present embodiment is also configured as conventionally known, and generally includes an injection unit 2 and a platen device 3. The injection unit 2 includes a cylinder barrel 5 and a screw 6 provided in the cylinder barrel 5 so as to be capable of being driven in a rotational direction in the plasticizing direction and in an axial direction in the injection direction. On the other hand, the mold platen device 3 is inserted and fixed to the fixed platen 8, the mold clamping housing 9, the tie bars 10, 10,... Connecting the fixed plate 8 and the mold clamping housing 9, and the tie bars 10, 10,. The movable board 11 is configured to open and close the mold with respect to the board 8 and a toggle mechanism 13 provided between the mold clamping housing 9 and the movable board 11. A fixed mold 15 is attached to the fixed plate 8, and a movable mold 16 is attached to the movable plate 11. The injection unit 2 is inserted from an opening provided in the fixed platen 8, and the injection nozzle 18 provided at the tip of the cylinder barrel 5 is in contact with the sprue of the fixed mold 15. Such an injection molding machine 1 is controlled by a controller 20, and the controller 20 is provided with a display, that is, a display device 21.

  In the injection molding machine 1 according to the present embodiment, the molds 15 and 16 are clamped by the mold platen device 3 and the injection material is melted by the injection unit 2 in the same manner as the conventionally known injection molding machines. , 16, and after waiting for cooling and solidification of the injection material, the mold is opened by the platen device 3 to obtain a molded product. However, the injection molding machine 1 according to the present embodiment has a molding condition adjustment support function that provides reference information for reference to the operator so that the molding conditions can be easily adjusted, that is, the so-called molding conditions can be determined. It is characterized in that it has. The molding condition adjustment support function according to the present embodiment is as follows. That is, the operator inputs data related to the molded product such as the weight of the molded product, the type of injection material, and a runner formed when the molded product is molded into the controller 20. Then, the controller 20 calculates the reference information from the data input by the four arithmetic operations and displays it on the display device 21. The operator can adjust the molding conditions safely with reference to the reference information as appropriate. Since the reference information is calculated by the four arithmetic operations in this way, the operator can easily verify the information and intuitively grasp the suitability. Furthermore, there is almost no possibility that software bugs are mixed in the four arithmetic operations, and there is no possibility that abnormal values are mixed in the calculated reference information. Therefore, the possibility of damaging the dies 15 and 16 by setting abnormal molding conditions can be made substantially zero. In the present specification, various data related to the molded product input to the controller 20 and used as the basis for calculating the reference information are collectively referred to as basic data. There are various types of reference information useful for adjusting the molding conditions, and the basic data differs depending on the reference information to be calculated. Hereinafter, various reference information will be described.

(1) The specific gravity of the molten injection material in the cylinder barrel 5 is provided as reference information.
Basic data: Molded product weight K1
Reference information: Specific gravity S1 when the injection material is melted
An example is shown in FIG. Reference information is calculated and provided as follows. A molded product is injection-molded in the injection molding machine 1. From the position of the screw 6 when the injection material is measured, the position of the screw 6 when the injection is completed, and the inner diameter of the cylinder barrel 5, the total injection volume T1 that is the volume of the molten injection material actually injected Calculate Then, the specific gravity S1 when the injection material is melted is calculated by the following calculation formula and displayed on the display device 21.
Specific gravity S1 at the time of melting of the injection material = molded product weight K1 / total injection volume T1

(2) When a sample of a molded product is given but the molding conditions are unknown, the stroke of the screw estimated to be necessary for molding the molded product, that is, the estimated molded product stroke is provided as reference information. It is assumed that glass fibers are added to the molded product at a predetermined addition rate.
Basic data: Molded product weight K1
Type of injection material K2
Glass fiber addition rate K3
Reference information: Specific gravity S2 of the injection material in the melted state with glass fiber added
Estimated molded product stroke S3
An example is shown in FIG. With reference to a predetermined table storing the specific gravity data of the injection material stored in the controller 20, the specific gravity K4 of each injection material at normal temperature and at the time of melting is determined from the type of the input injection material. Get K5. According to the following formula, the specific gravity S2 of the injection material melted and added with the glass fiber is obtained.
Specific gravity S2 of the injection material in the state of melting and glass fiber added
= (1-glass fiber addition ratio K3) × specific gravity K5 of the injection material at the time of melting
+ Glass Fiber Addition Rate K3 × Glass Fiber Specific Gravity Next, an estimated molded product stroke S3 is obtained by the following equation.
Estimated molded product stroke S3 = Molded product weight K1 / specific gravity S2 / injection material specific gravity S2 / melted glass fiber added cross-sectional area The display unit 21 displays the obtained reference information. In the above description, the specific gravity K4 and K5 of the injection material at normal temperature and melting are obtained from the type K2 of the injection material, but these specific gravity K4 and K5 are directly used as basic data for the controller 20. May be input.

(3) A runner sample formed when molding a molded product and a sample of the molded product are given, but it is necessary to fill each of the runner and molded product when the molding conditions are unknown. The estimated screw stroke, that is, the estimated runner stroke, and the estimated molded product stroke are provided as reference information.
Basic data: Runner weight K6
Molded product weight K1
Type of injection material K2
Reference information: Estimated runner stroke S4
Estimated molded product stroke S3
An example is shown in FIG. The specific gravity K5 of the injection material at the time of melting is obtained from the kind K2 of the resin material. Reference information is obtained by the following formula.
Estimated runner stroke S4 = runner weight K6 / specific gravity of injection material at melting K5 / cross-sectional area of cylinder barrel Estimated molding stroke S3 = weight of molded product K1 / specific gravity of injection material at melting K5 / cross-sectional area of cylinder barrel The reference information is displayed on the display device 21. When injection molding is performed with a plurality of injection stages, information on the estimated runner stroke S4 and the estimated molded product stroke S3 is useful. The specific gravity K5 of the injection material at the time of melting may be input as basic data.

(4) When an injection time T2 required for injection is given, an injection speed, which is a screw speed at the time of injection, is calculated and provided as reference information.
Basic data: Molded product weight K1
Type of injection material K2
Reference information: Injection speed S5
An example is shown in FIG. When the injection time T2 is input to the controller, the injection speed S5 is calculated by taking into account screw acceleration / deceleration according to a predetermined conversion formula.
For example, it can be calculated as follows. The specific gravity K5 of the injection material at the time of melting is obtained from the type K2 of the resin material, and the estimated molded product stroke S3 is obtained by the following equation.
Estimated molded product stroke S3 = Molded product weight K1 / Specific gravity of injection material K5 at melting / Cross-barrel cross-sectional area The average screw speed can be obtained by dividing estimated molded product stroke S3 by injection time T2. The injection speed S5 is obtained by multiplying by a predetermined constant taking into account the acceleration / deceleration of the screw. The obtained injection speed S5 is displayed on the display device 21.

(5) When an injection speed T3, which is the speed of the screw at the time of injection, is given, the injection time S6 is calculated and provided as reference information.
Basic data: Molded product weight K1
Type of injection material K2
Reference information: Injection time S6
FIG. 2 (o) shows an example of injection molding with three injection stages. The following data is input to the controller.
Injection speed T3 in each stage 1 to 3
Screw position T4 at each stage
The injection time S6 can be calculated from the injection speed T3 and the screw position T4 at each stage 1 to 3 in consideration of the acceleration / deceleration of the screw. However, the screw position T4 when the third-stage injection is completed, that is, the screw position T4 when the injection is completed may not be input. In this case, as described above, the specific gravity K5 of the injection material at the time of melting is obtained from the type K2 of the resin material, the estimated molded product stroke S3 is obtained, and the screw position T4 at the completion of injection can be determined. Then, the injection time S6 can be calculated. The injection time S6 is displayed on the display device 21.

DESCRIPTION OF SYMBOLS 1 Injection molding machine 2 Injection unit 3 Mold board apparatus 5 Cylinder barrel 6 Screw 8 Fixed board 9 Clamping housing 11 Movable board 15 Fixed side mold 16 Movable side mold 20 Controller 21 Display apparatus

Claims (7)

In an injection molding machine comprising a cylinder barrel and a screw provided in the cylinder barrel so as to be capable of being driven in the rotational direction and the axial direction, and having a mold for molding a predetermined molded product,
Calculating reference information useful for determining molding conditions for adjusting molding conditions from basic data related to the molded product input to the controller of the injection molding machine, and displaying the reference information on a display device of the controller A method for assisting adjustment of molding conditions of an injection molding machine. The method according to claim 1, wherein the basic data includes a type of an injection material, a runner weight that is a weight of a runner formed when the molded product is molded, and a molded product weight that is a weight of the molded product. And consist of
The reference information includes an estimated runner stroke and an estimated molded product stroke which are estimated values of the stroke of the screw necessary for filling the runner and the molded product, and the estimated runner stroke and the estimated molded product. The stroke is calculated from the basic data, the specific gravity of the injection material at normal temperature and when melted, and the inner diameter of the cylinder barrel, and a molding condition adjustment support method for an injection molding machine. The method according to claim 1, wherein the basic data comprises a molded product weight that is a weight of the molded product,
The reference information includes a specific gravity at the time of melting of the injection material, and the specific gravity at the time of melting of the injection material is calculated from the basic data and the volume of the resin material actually melted. A method for assisting adjustment of molding conditions of an injection molding machine. The method according to claim 1, wherein the basic data includes a molded product weight, which is a weight of the molded product, a type of an injection material, and an addition rate of glass fiber added to the injection material.
The reference information includes a specific gravity of the injection material in a state where the glass fiber is melted and an estimated molded product stroke which is an estimated value of the stroke of the screw necessary to mold the molded product, The specific gravity of the injection material melted and added with glass fiber and the estimated molded product stroke are obtained from the basic data, the specific gravity of the injection material at normal temperature and when melted, and the inner diameter of the cylinder barrel. A method for assisting adjustment of molding conditions of an injection molding machine, characterized by: calculating. The method according to claim 1, wherein the basic data includes a molded product weight that is a weight of a molded product, and a type of an injection material.
The reference information includes an injection speed that is a speed at the time of injection of the screw, and the injection speed is calculated from the basic data and an injection time that is a time required for injection. Molding condition adjustment support method. The method according to claim 1, wherein the basic data includes a molded product weight that is a weight of a molded product, and a type of an injection material.
The reference information includes an injection time that is a time required for injection, and the injection time is calculated from the basic data and an injection speed that is a speed at the time of injection of the screw. Molding condition adjustment support method.   An injection molding machine comprising a controller that implements the molding condition adjustment support method according to any one of claims 1 to 6.

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