JP2024065431A - Injection molding machine - Google Patents

Abstract

[Problem] To provide an injection molding machine that can more effectively utilize the analysis results of gas generated from a molten resin material. [Solution] The injection molding machine 1 of the present invention comprises an analysis device 30 that analyzes gas generated during injection molding in one or both of an injection unit 10 and a mold unit 20, and a control device 40 that controls the operation of the injection unit 20 based on preset molding conditions. The analysis device 30 identifies the type of gas and the amount of gas of the gas type. When the amount of gas of the gas type exceeds a predetermined threshold value, the control device 40 displays a message suggesting that the molding condition settings be changed, or automatically changes the molding condition settings. [Selected Figure] Figure 1

Description

The present invention relates to an injection molding machine.

Injection molding machines melt solid resin material called pellets inside the heating barrel of the injection device, and then inject and fill the pellets into a mold to create a molded product. If the resin material remains in a heated and molten state for a long period of time, it will decompose and deteriorate (carbonize) as a result of the decomposition. Therefore, the molten resin material is monitored to ensure high quality of the molded product and reduce molding defects.

As an example, Patent Document 1 proposes collecting gas generated at at least two locations, i.e., multiple locations, in the injection device, and performing at least one of quantitative and qualitative analysis on each of the collected gases. As an example, the analysis in Patent Document 1 is performed using gas chromatography. According to Patent Document 1, it is possible to prevent deterioration of resin during injection molding by understanding the entire injection molding process and taking appropriate measures.

JP 2019-181890 A

The present invention aims to provide an injection molding machine that can more effectively utilize the analysis results of gas generated from molten resin material.

The injection molding machine of the present invention comprises an injection device having a heating barrel, a heater capable of heating the heating barrel, and a plasticizing screw inserted into the heating barrel and supported rotatably, a mold device for molding molten resin injected from the injection device, an analysis device for analyzing gas generated during injection molding in one or both of the injection device and the mold device, and a control device for controlling the operation of the injection device based on preset molding conditions.
The analyzer identifies the type of gas and the amount of the gas of the gas type.
When the amount of a particular gas type exceeds a predetermined threshold, the control device suggests changing the settings of the molding conditions, or automatically changes the settings of the molding conditions.

In the injection molding machine of the present invention, it is preferable that the molding conditions set in the control device are at least one of the temperature of the heating barrel, the rotation speed of the plasticizing screw, the plasticizing back pressure, the injection speed, and the time for stopping the rotation of the plasticizing screw.

In the injection molding machine of the present invention, it is preferable that the control device stores a number of different thresholds for each molding condition and a message corresponding to each threshold, and when the amount of gas exceeds a threshold, displays a message corresponding to the threshold.

In the injection molding machine of the present invention, it is preferable to identify the raw resin from which the molten resin is made based on the gas type and lower the upper limit of the molding conditions that are preset.

In the injection molding machine of the present invention, it is preferable to identify that the gas type contains a halogen-based element, and to display a message indicating that a halogen element is contained.

According to the present invention, it is possible to suggest changes to subsequent molding conditions or to change the molding conditions based on the analysis results of the gas generated from the molten resin material. Therefore, with the injection molding machine of the present invention, the gas analysis results can be used more effectively.

1 is a diagram showing a schematic configuration of an injection molding machine according to an embodiment; FIG. 2 is a diagram illustrating a configuration of a control device according to the embodiment. 13A shows an example of judgment data stored in a judgment data storage unit of a control device according to an embodiment, where FIG. 13A shows an example in which there is one threshold value for each gas type, and FIG. 13B shows an example in which there are multiple threshold values for each gas type. 4 is a table showing an example of judgment data stored in a molding condition data storage unit of the control device according to the embodiment. FIG. 11 is a flow chart showing an example of an operation procedure of the injection unit controlled by the control unit according to the embodiment, illustrating an example in which an operator changes molding conditions. 10A and 10B are diagrams showing examples of message displays according to an embodiment, in which (a) is a display suggesting lowering the heater barrel temperature, and (b) is a display suggesting lowering the heater barrel temperature by 5° C. FIG. 13A and 13B show other examples of the display of a message according to an embodiment, in which (a) is a display suggesting reducing the rotation speed of the plasticizing screw, and (b) is a display suggesting reducing the rotation speed of the plasticizing screw by 10 rpm. 10A and 10B show further examples of the display of the message according to the embodiment, in which (a) is a display suggesting that the injection speed should be reduced by 10% because the first gas amount threshold has been exceeded, and (b) is a display suggesting that the injection speed should be reduced by 5% because the second gas amount threshold has been exceeded. FIG. 11 is a flow chart showing an example of an operation procedure of the injection device by the control device according to the embodiment, showing an example in which the processing unit automatically changes molding conditions. 10A and 10B are diagrams showing examples of message displays according to an embodiment, in which (a) shows a display indicating that the plasticization back pressure has been reduced, and (b) shows a display indicating that the plasticization back pressure has been reduced by 10%. Data indicating the priority order for changing molding conditions stored in a judgment data storage unit, where (a) is data associating the priority order with molding conditions, and (b) is data further associating the contents of the change. The data associates a type of gas with a resin material produced by the gas when heated, and an upper limit value for each molding condition of the resin material.

Hereinafter, an injection molding machine 1 according to an embodiment will be described with reference to the accompanying drawings.
The injection molding machine 1 analyzes the gas generated from the resin material when the resin material is melted for injection molding, and identifies the type and amount of the gas as the analysis result. Furthermore, if the analysis result is out of the normal range, the injection molding machine 1 warns accordingly and suggests or changes the molding conditions.
Below, the schematic configuration of the injection molding machine 1 will be described, and then the operation control of the injection molding machine 1 using the results of the gas analysis will be described.

[Schematic configuration of injection molding machine 1: FIG. 1]
The injection molding machine 1 includes an injection device 10 that melts and injects a resin material, and a mold device 20 that molds the molten resin injected from the injection device 10. The injection molding machine 1 includes an analysis device 30 that analyzes gas generated during injection molding in one or both of the injection device 10 and the mold device 20, and a control device 40 that controls the operation of the injection device 10 and the mold device 20. The control device 40 can reflect the analysis results in the analysis device 30 in the operation of the injection device 10.

[Injection device 10: FIG. 1]
The injection device 10 includes a heating barrel 11, a heater 12 fitted around the heating barrel 11, a plasticizing screw 13 rotatably inserted into the heating barrel 11, and a raw material hopper 14 for accumulating resin pellets P as raw material to be supplied to the inside of the heating barrel 11. The heating barrel 11 is provided with a heating barrel vent 11A at a connection portion with a gas pipe 33 described later, and the heating barrel vent 11A is composed of fine holes or has a porous material interposed therein.

The injection device 10 includes a first rotating electric machine 15 that rotates the plasticizing screw 13 forward or backward, and an advance/retract actuator 16 that moves the plasticizing screw 13 forward or backward. The advance/retract actuator 16 includes a second rotating electric machine 17 whose position is fixed relative to the heating barrel 11, and a ball screw 18 operated by the second rotating electric machine 17. The ball screw 18 includes a screw shaft 18A that is driven to rotate by the second rotating electric machine 17, and a ball nut 18B that is rotatably fitted to the screw shaft 18A and supports multiple rolling balls between the screw shaft 18A and the ball nut 18B.

The injection device 10 injects molten resin by controlling the heating of the inside of the heating barrel 11 by the heater 12, the rotation of the plasticizing screw 13 by the rotation drive of the first rotating electric machine 15, and the forward and backward movement of the plasticizing screw 13 by the operation of the forward and backward actuator 16. The heating of the heater 12 and the rotation drive of the first rotating electric machine 15 and the second rotating electric machine 17 are performed based on instructions from the control device 40.

[Molding device 20: FIG. 1]
The mold device 20 includes a fixed mold 21 whose position is fixed, and a movable mold 23 provided to correspond to the fixed mold 21. A cavity 25, which is a space filled with molten resin, is formed between the fixed mold 21 and the movable mold 23. The fixed mold 21 and the movable mold 23 are supported by a mold clamping mechanism (not shown), which clamps the mold when injection molding is performed and opens the mold when the molded product is removed.

The injection molding machine 1 equipped with the above elements performs injection molding in the following procedure.
Injection molding includes a clamping step of the fixed mold 21 and the movable mold 23, a plasticization step of heating and melting the resin pellets P inside the heating cylinder 11 to plasticize them, an injection step of injecting and filling the plasticized molten resin into the cavity 25 formed by the fixed mold 21 and the movable mold 23, a holding step of cooling the molten resin filled in the cavity 25 until it solidifies, a mold opening step of opening the mold, and an ejection step of ejecting the molded product cooled and solidified in the cavity. Injection molding is a cycle of this series of steps, and a desired number of molded products are produced by performing a plurality of cycles continuously or intermittently.

[Analysis device 30: FIG. 1]
The analysis device 30 analyzes gas generated from the resin material melted in the injection molding machine 1. The analysis result is sent to the control device 40. The analysis device 30 includes an analyzer 31 that analyzes the taken-in gas, a gas pipe 33 that connects the analyzer 31 and the heating cylinder 11, and a suction pump 35 provided midway along the gas pipe 33. The analysis device 30 performs at least one of a qualitative analysis and a quantitative analysis of the gas that reaches the analyzer 31 through the gas pipe 33 by operating the suction pump 35 during the plasticization process and the injection process in which the molten resin is present inside the heating cylinder 11 during the injection molding.

A known analyzer capable of performing at least one of qualitative and quantitative gas analysis is applied as the analyzer 31. A pyrolysis gas chromatography mass spectrometer is preferable as this analyzer 31. Other analytical methods that can be applied include Fourier transform infrared spectroscopy (FT-IR), near infrared spectroscopy (NIRS), thermal infrared spectroscopy (TIR), ultraviolet-visible spectroscopy (UV-Vis), ion chromatography, and dispersive infrared spectroscopy.

The gas pipe 33 is connected to the heating cylinder vent 11A of the heating cylinder 11. By operating the suction pump 35, gas generated from the molten resin is supplied to the analyzer 31 through the heating cylinder vent 11A and the gas pipe 33. The suction pump 35 may be operated in both the plasticization process and the injection process, or may be operated only in one of the plasticization process and the injection process. In addition, when the suction pump 35 is operated in at least one of the plasticization process and the injection process, the suction pump 35 may be operated throughout the entire process, or may be operated only for a part of the process. In addition, the gas analysis may be performed periodically or irregularly. The specific timing of the gas analysis described later is limited to a part of the plasticization process and a part of the injection process.

[Control device 40: FIG. 1]
The control device 40 controls the operations of the injection device 10, the mold device 20, and the analysis device 30 of the injection molding machine 1. The control of these operations may be based on information obtained from the components of the injection molding machine 1. The control of the injection device 10 by the control device 40 includes the rotation and forward/backward movement of the plasticizing screw 13 by controlling the rotation of the first rotating electric machine 15 and the second rotating electric machine 17. The control of the mold device 20 by the control device 40 includes the operation of an opening/closing mechanism that opens and closes the fixed mold 21 and the movable mold 23. The control device 40 will be described below, focusing on the control related to the analysis device 30.

[Configuration of the control device 40: FIG. 2]
As shown in Fig. 2, the control device 40 includes a transmission/reception unit 41, a storage unit 43, a processing unit 45, and an input/display unit 47. This functional division is an example, and the functions can be further subdivided or integrated. As an example, the input/display unit 47 can be divided into a portion specialized for input and a portion specialized for display. The control device 40 is configured by a computer device including a CPU (Central Processing Unit), a semiconductor memory, a display, and the like.

[Transmitter/receiver 41]
The transmitting/receiving unit 41 transmits signals instructing the operation of each of the heater 12, the first rotating electric machine 15, and the second rotating electric machine 17. The transmitting/receiving unit 41 also receives data (analysis data) relating to the analysis results of the gas in the analysis device 30. The analysis data received by the transmitting/receiving unit 41 is transferred to the processing unit 45.

[Memory unit 43: FIG. 3 and FIG. 4]
The memory unit 43 stores data necessary for controlling the operation of the injection molding machine 1, and in particular, for handling the analysis data obtained by the analysis device 30, it includes a judgment data memory unit 43A and a condition data memory unit 43B.

[Determination data storage unit 43A: FIG. 3]
The judgment data memory unit 43A stores data (judgment data) that serves as a standard for determining whether the analysis data is within an acceptable range by comparing it with the analysis data, whether the detected amount of the detected components has reached a level that is harmful to the equipment and workers, or whether the molten resin is sound at the time of the analysis.

FIG. 3 shows an example of the determination data.
FIG. 3(a) shows an example of a threshold value as judgment data for a resin material. The threshold value here is the upper limit of the content allowed for the gas type. That is, in FIG. 3(a), the gas type and threshold value that are generated by melting are specified corresponding to the resin material. For example, the gas type corresponding to the molded product "MP1" is "G1" and the threshold value is "TH1". If the gas type specified by the analysis data is "G1" and the gas amount is "d1", the judgment data "TH1" and the analysis data "d1" are compared to judge the gas type "G1". In FIG. 3(a), the gas types and the gas amount threshold values are associated with each other for the other molded products "MP1" to "MP1". For example, if d1 (analysis data) is larger than TH1 (judgment data), it is recognized that the temperature of the molten resin has risen too much and exceeded the allowable range.

The judgment data in FIG. 3(a) is associated with information on whether each gas type contains a halogen element. A halogen element is information that can be included in a message and is included in a specific gas type. A halogen element is an element belonging to the 17th group of the periodic table, and is a general term for fluorine, chlorine, bromine, iodine, and astatine. These halogen elements are generally contained in flame-retardant resins as flame retardants, but when this flame-retardant resin is thermally decomposed and the halogen elements are gasified, they become highly corrosive and highly toxic gases. In addition, fluorine-based resins such as PTFE (polytetrafluoroethylene) and PFA (perfluoroalkoxyalkane) contain fluorine, and chlorine-based resins such as polyvinyl chloride contain a large amount of chlorine, so when they are thermally decomposed, fluorine and chlorine are gasified in the same way as flame-retardant resins.

In FIG. 3(b), multiple thresholds, for example two thresholds, are set for the same resin type. As an example, the gas type corresponding to a molded product called "MP1" is "G1", and the gas amount thresholds are "TH11" and "TH12". Note that TH11<TH12. Also, for example, the gas type corresponding to a molded product called "MP3" is "G3", and the thresholds are "TH31" and "TH32". In this case too, TH31<TH32. In this way, the judgment data is set in multiple stages in order to suggest a response according to the gas amount. This response will be described later.

[Condition data storage unit 43B: FIG. 4]
The condition data storage unit 43B stores data on the conditions for generating and injecting molten resin by the injection device 10. These conditions can be input by an operator who operates the injection molding machine 1 to perform molding work, using the input/display unit 47. In addition to input by the operator, if molding conditions are set in advance for a molded product to be produced, for example, the conditions are stored in the condition data storage unit 43B.

An example of molding condition data is shown in Figure 4. Figure 4 shows examples of molding conditions for each of several types of molded products, including the heating barrel temperature, screw rotation speed, plasticization back pressure, injection speed, and screw stop time. For example, for molded product "MP1", the heating barrel temperature T1, screw rotation speed R1, plasticization back pressure P1, injection speed V1, and screw stop time S1 are set. When producing molded product "MP1", injection molding begins at heating barrel temperature T1 and screw stop time S1, but one of the molding conditions may be changed depending on the results of the determination of the gas concentration generated from the molten resin. The same applies to molded products "MP2" and onwards.

Figure 4 shows an example of associating molded products with molding conditions, but molding conditions can be set according to the type of mold device 20, for example.

[Control procedure: Figure 5]
Next, a procedure for controlling the operation of the injection molding machine 1 will be described with reference to FIG.
<Molding condition setting: S101>
At the start of injection molding, molding conditions are set.
When the operator inputs molding conditions, the molding conditions input from the input/display unit 47 are stored in the condition data storage unit 43B, and the stored molding conditions are acquired by the processing unit 45. The processing unit 45 controls the operations of the heater 12, the first rotating electric machine 15, and the second rotating electric machine 17 so as to match the acquired molding conditions.
If the molding conditions are stored in advance in the condition data storage unit 43B, the stored molding conditions are acquired by the processing unit 45. The processing unit 45 controls the operations of the heater 12, the first rotating electric machine 15, and the second rotating electric machine 17 so as to conform to the acquired molding conditions.
<Molding execution: S103>
Once the molding conditions are set, injection molding is continuously performed, with the above-mentioned mold clamping step, plasticizing step, injection step, holding step, mold opening step, and removal step forming one cycle.

<Gas analysis: S105>
During injection molding, gas analysis is performed by the analyzer 30. This gas analysis identifies the type of gas (gas species) and the amount of that gas species. The identified gas species and amount are sent as analysis data to the processor 45 via the transmitter/receiver 41. The processor 45 reads out judgment criteria data for the gas to be analyzed for the molded product from the judgment data storage unit 43A.
The gas analysis can be carried out continuously during the injection molding, or can be carried out intermittently at time intervals, for example, every hour.

<Determination of gas type: S107>
The processing unit 45 compares the acquired reference data with the analysis data to determine whether the gas type in the analysis data (analysis gas type) matches the gas type in the reference data (reference gas type), i.e., whether the predetermined gas type has been detected by the analysis. If the predetermined gas type has not been detected, gas analysis is further performed (S107 N).

<Gas amount determination: S109, message display: S111>
If the analyzed gas type matches the reference gas type (S107 Y), the processing unit 45 compares the gas amount of the analysis data (analyzed gas amount) with the gas amount of the judgment reference data (gas amount threshold) (S109). If the analyzed gas amount does not reach the gas amount threshold, gas analysis is further performed (S109 N). If the analyzed gas amount reaches the gas amount threshold, the processing unit 45 causes the input/display unit 47 to display a message to that effect (S111).

<End of molding: S113>
The processor 45 judges whether or not the predetermined cycle of injection molding has been completed (S113). If the predetermined cycle of injection molding has been completed, the processor 45 terminates the operation of the injection molding machine 1, and if not, continues the procedure from gas analysis (S105) to message display (S111).

[Message display examples: Figures 6, 7, and 8]
Next, an example of a message displayed on the input/display unit 47 will be described with reference to FIG.
As shown in Fig. 6(a), the message displays information IF1 about the molded product (MP1), information IF2 that the amount of the detected gas type (G1) has exceeded the gas amount threshold value (TH1), and information IF3 that suggests changing the molding conditions. Here, information about the molded product MP1 is shown, but if any of the molded products MP2 to MP5 shown in Fig. 3 is being molded, information about any of MP2 to MP5 will be displayed.
FIG. 6(a) shows that the detected gas species G1 contains halogen elements.

Although only visual messages using the input/display unit 47 are shown here, audio messages can also be issued in addition to visual messages. Also, if the operator has a mobile device such as a tablet terminal or smartphone for operating the injection molding machine 1, the visual message can also be displayed on this mobile device. It can also be transmitted via communication to a separate alarm device that is independent of the injection molding machine 1 but located in the vicinity of the injection molding machine 1, such as an alarm display, rotating light, or digital signage, to notify workers in the vicinity of the injection molding machine 1. Either of these is effective in reliably notifying operators and workers in the vicinity who are away from the injection molding machine 1 that a message is being displayed.

The operator operating the injection molding machine 1 refers to the displayed message and lowers the set temperature of the heater 12 to lower the temperature of the heating barrel 11. The extent to which the temperature should be lowered can be determined, for example, by a temperature previously determined in the operation manual, or by a temperature determined based on the operator's experience. As shown in FIG. 6(b), the message can display a scale for changing the setting, such as "lower by 5°C."

Figure 6 shows "heater barrel temperature" as an example of a molding condition to be changed, but other molding conditions that can be used include the rotation speed of the plasticizing screw, the plasticizing back pressure (screw retreat speed), the injection speed, and the time to stop the screw rotation. In any case, when changing the molding conditions, the values will be lowered from the respective initial molding conditions.

FIG. 7 shows another example of the message.
While Fig. 6 merely indicates that the amount of the detected gas type (G1) has exceeded the gas amount threshold (TH1), Fig. 7(a) indicates the degree of excess, for example, "exceeding the gas amount threshold by 20%". The degree of excess can be determined by a simple calculation in the processing unit 45 when comparing the analyzed gas amount with the gas amount threshold. By referring to the degree of excess, the operator can easily determine how much to reduce the rotation speed of the plasticizing screw 13. However, as shown in Fig. 7(b), a scale of how much to reduce the rotation speed of the plasticizing screw 13 can also be displayed.

FIG. 8 shows yet another example of the message, in which the gas determination criteria include the multiple-stage gas amount thresholds (first gas amount reference value, second gas amount reference value) shown in FIG. 3(b).
FIG. 8A shows a first message indicating that the amount of the detected gas type (G5) has exceeded the first gas amount threshold (TH51) and suggesting that the injection speed be reduced by 10%.
8B, a second message is displayed to indicate that the amount of the detected gas type (G5) has exceeded the second gas amount threshold (TH52) and to suggest that the injection speed be reduced by 5%. This is because even if the injection speed is reduced by 10% by the operator or automatically in accordance with the first message, the temperature of the molten resin subsequently rises, causing the amount of the gas type (G5) to exceed the second gas amount threshold (TH52). "Reduce the injection speed by 10%" and "Reduce the injection speed by 5%" may be stored in association with the first gas amount threshold (TH51) and the second gas amount threshold (TH52), respectively.

In most cases, messages suggesting changes to molding conditions are displayed during a molding cycle. In this case, the molding conditions can be changed during the current molding cycle, but it is preferable to change the molding conditions from the next molding cycle.
When molding conditions are changed during a molding cycle, it may be difficult to distinguish whether the molded product was molded under the molding conditions before the change or the molding conditions after the change. In this case, even if it becomes necessary to trace the molded product under the molding conditions later, it may be difficult to distinguish. In contrast, if the molding conditions are changed in units of a molding cycle, it is easy to distinguish the molding conditions.

[Automatic change of molding conditions: Figures 9, 10, and 11]
Although the above shows an example in which the operator changes the molding conditions, the molding conditions can also be changed automatically.
8 shows the procedure for automatically changing the molding conditions, and if the analyzed gas amount exceeds the gas amount threshold, the processing unit 45 can change the molding conditions (FIG. 9 S110) before displaying the message on the input/display unit 47. However, this is not limiting, and the molding conditions can be changed in parallel with displaying the message on the input/display unit 47, or the molding conditions can be changed after displaying the message on the input/display unit 47.

<Example of display of molding condition change>
FIG. 9 shows an example of a message displayed when molding conditions are changed automatically.
FIG. 10(a) shows the change in plasticization back pressure (screw retreat speed), and FIG. 10(b) shows the extent to which the plasticization back pressure is further reduced.

<Priority order for changes in molding conditions>
When the molding conditions are changed automatically, it is preferable to determine the priority order of the molding conditions to be changed in advance. An example of this is shown in FIG. 11(a). This priority order data is stored in the memory unit 43, and when the processing unit 45 determines that the amount of analyzed gas exceeds the gas amount threshold, the processing unit 45 reads out the priority order data and changes the molding conditions. For example, when it is determined that the amount of analyzed gas exceeds the gas amount threshold, the processing unit 45 changes the molding conditions in the following procedure: first, the heater barrel temperature is set low, and if the threshold is still exceeded after one hour, the screw rotation speed is reduced, and if the threshold is still exceeded after another hour, the back pressure is reduced. In FIG. 11(b), the priority order and the molding conditions are stored in association with the change contents, and the processing unit 45 controls the operation of the relevant parts according to the change contents read out.

<Upper limits of molding conditions for resin materials>
When the molding conditions are changed automatically, it is preferable to identify the raw material resin to be injection molded from the gas type identified by the analyzer 30, and change the upper limit of the molding conditions to a value corresponding to the raw material resin. Specifically, the process is as follows.

12, the determination data storage unit 43A stores data in which a gas type is associated with a resin material that is generated by the gas type when heated. This data is associated with an upper limit value based on the heat resistance of the resin material, for example, the heat resistance temperature.
Referring to an example in FIG. 12, gas type G1 is generated from resin material PL1, and the upper limit values of each molding condition for this resin material PL1 are heating barrel temperature: T1max, screw rotation speed: R1max, plasticization back pressure: P1max, injection speed: V1max, and screw stop time: S1max.

These upper limit values of molding conditions are upper limits that regulate the molding conditions input by the operator using the input/display unit 47. These upper limit values are determined based on the prediction that molding under molding conditions above these limits will cause the resin material to thermally decompose, resulting in the amount of corrosive gas and toxic gas generated exceeding the allowable value. In other words, even if the operator inputs molding conditions that exceed the molding conditions shown in Figure 12, the input is canceled, and the molding conditions shown in Figure 12 are set instead, and subsequent molding is performed according to these conditions. If the molding conditions input by the operator are equal to or less than the upper limit values of the molding conditions shown in Figure 12, subsequent molding is performed under the input molding conditions.

When the analysis device 30 identifies gas type G1 and the amount of gas type G1 exceeds the gas amount threshold TH1, the processing unit 45 changes the upper limit of the molding conditions shown in FIG. 12 to be lowered. This is to tighten the restrictions on the molding conditions input by the operator thereafter, to prevent unintended gases such as corrosive gases from being generated thereafter. When it is detected that the amount of gas type G1 exceeds the gas amount threshold TH1, the upper limit of the heater barrel temperature: T1max is lowered to the upper limit: T1max-30 (°C).

[effect]
According to the injection molding machine 1 of this embodiment, when the amount of gas of a gas type exceeds a predetermined threshold, a message suggesting that the settings of the molding conditions be changed is displayed, or the settings of the molding conditions can be changed automatically. Therefore, an operator who refers to the message can change the molding conditions thereafter, so that molding can be performed under appropriate conditions thereafter and a molded product with excellent quality can be obtained. Furthermore, if the settings of the molding conditions can be changed automatically, molding can be performed under appropriate conditions thereafter and a molded product with excellent quality can be obtained without the operator having to perform an operation to change the molding conditions. In this way, the injection molding machine 1 can make more effective use of the gas analysis results.

Injection molding machine 1 can display a message or automatically change the molding conditions based on the gas detected during molding, allowing the operator to change the molding conditions or the molding conditions to be changed automatically in real time.

In the injection molding machine 1, if the threshold value for the gas amount is set in multiple stages and a message is displayed according to the multiple threshold stages, the operator can change the molding conditions appropriately in response to this message.

According to the injection molding machine 1, by setting the upper limit of the molding conditions, it is possible to prevent inputting excessive values as molding conditions for the raw material resin due to erroneous input. This makes it possible to prevent corrosion and damage of equipment components due to the generation of corrosive gas caused by excessive resin decomposition and deterioration. Furthermore, setting the upper limit of the molding conditions makes it possible to prevent the generation of excessive driving force more than necessary, which is also effective in saving energy.
Furthermore, by lowering the upper limit of the molding conditions, it is possible to minimize the generation of gas in an amount exceeding the threshold value in subsequent moldings.

With the injection molding machine 1, it is possible to include a message that indicates that the gas species contains a halogen element. Here, the operator or molding company performing the molding work is often not informed of the resin they are using, simply performing the molding work using a specified resin. In this case, they are not aware that a resin that is not corrosive or toxic when molded under proper conditions may become corrosive or toxic beyond the expectations of the resin selector when it decomposes due to excessive heat such as an abnormally high temperature. In this way, even if the operator is not aware of the corrosiveness or toxicity of the resin in advance, the present invention allows them to recognize the corrosiveness or toxicity of the resin during molding and perform the molding work carefully.

In addition to the above, the configurations given in the above embodiments can be selected or appropriately changed to other configurations without departing from the spirit of the present invention.
In the embodiment described so far, the gas to be analyzed is collected from inside the heating cylinder 11, but the present invention is not limited to this. The gas to be analyzed can be collected from the injection nozzle 19, the rear end 50 of the heating cylinder 11, the mold device 20, or via the raw material hopper 14, as disclosed in, for example, Patent Document 1.

REFERENCE SIGNS LIST 1 injection molding machine 10 injection device 11 heating barrel 11A heating barrel vent 12 heating heater 13 plasticizing screw 14 raw material hopper 15 first rotating electric machine 16 forward/backward actuator 17 second rotating electric machine 18A screw shaft 18B ball nut 20 mold device 21 fixed mold 23 movable mold 25 cavity 30 analysis device 31 analyzer 33 gas pipe 35 suction pump 40 control device 41 transmission/reception unit 43 memory unit 43A judgment data memory unit 43B condition data memory unit 45 processing unit 47 input/display unit

Claims (5)

an injection device including a heating barrel, a heater capable of heating the heating barrel, and a plasticizing screw inserted into the heating barrel and rotatably supported;
a mold device for molding the molten resin injected from the injection device;
an analyzer for analyzing gases generated during injection molding in one or both of the injection device and the mold device;
A control device that controls the operation of the injection device based on preset molding conditions,
The analysis device comprises:
Identifying the type of gas and the amount of the gas of the gas type;
The control device includes:
When the amount of the gas of the gas type exceeds a predetermined threshold value,
The injection molding machine displays a message suggesting to change the settings of the molding conditions, or automatically changes the settings of the molding conditions.
The molding conditions set in the control device are:
At least one of the temperature of the heater barrel, the rotation speed of the plasticizing screw, the plasticizing back pressure, the injection speed, and the time to stop the rotation of the plasticizing screw;
2. The injection molding machine according to claim 1.
The control device includes:
storing a plurality of different threshold values for each of the molding conditions and the messages corresponding to the respective threshold values;
When the amount of gas exceeds each of the thresholds, the message corresponding to the threshold is displayed.
3. The injection molding machine according to claim 2.
The control device includes:
Identifying a raw material resin that is a source of the molten resin from the gas type, and lowering the upper limit value of the molding condition that is preset;
3. The injection molding machine according to claim 1 or 2.
The control device includes:
identifying that the identified gas species contains a halogen element and displaying the inclusion of a halogen element in the message;
3. The injection molding machine according to claim 1 or 2.

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