JPH02252519A - Method for controlling molding conditions in an injection molding machine with a visualized heating cylinder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method of controlling molding conditions for an in-line screw type injection molding machine, and in particular, the present invention relates to a method for controlling molding conditions in an in-line screw type injection molding machine.
The present invention relates to a method of controlling molding conditions in an injection molding machine having a visualization heating cylinder provided with four observation windows.

[Prior art] In an in-line screw type injection molding machine, a screw is arranged in a heating cylinder so that it can rotate and move forward and backward, and kneading, plasticizing, and metering (charging) the resin is performed by rotating and retracting the screw. The molding process involves injecting molten resin into the mold cavity by moving the screw forward.

In other words, in an in-line screw type injection molding machine, as is well known, the resin material supplied from the hopper to the rear of the screw in the heating cylinder is kneaded by the rotation of the screw and transferred to the tip side of the screw by the screw feeding action. At the same time, the resin material is plasticized and melted by the heat transmitted from the heating cylinder heated by a band heater, etc., the amount of resin material due to the crosstalk of the screw, and the heat generated by friction between the resin material and the metal surface. It has become so. This molten resin is stored at the tip of the screw, and as the screw rotates and retreats while controlling the back pressure, the point at which one shot's worth of molten resin is stored at the tip of the screw (the point at which measurement is completed) ), the rotation of the screw is stopped. Then, at the injection start timing after a predetermined time, the screw is moved forward, and the molten resin is injected and filled into the cavity of the mold.

In an injection molding machine that uses such a molding process.

To obtain high-quality molded products, it is necessary to achieve and control uniform and good plasticization melting of resin materials. For this reason, the screw design, which is largely involved in the resin kneading and plasticization mechanism, is set to an appropriate one, and during the plasticization metering (charging) process, the charging rotation speed, back pressure, charging speed, metering stroke, etc. During the process, check the injection pressure, injection speed, holding pressure switching position, holding pressure, etc.
Fine control was performed by referring to measurement information from sensors such as encoders and pressure heads.

Listing the above-mentioned molding conditions in more detail, at the time of plasticization metering (charging).

■Heater temperature of each zone.

■Measuring stroke.

■How to vary the screw rotation speed relative to the metering stroke.

■How to vary the back pressure with respect to the metering stroke.

■Amount of suckback and its speed.

There are factors such as, and during injection.

■Injection pressure.

■How to vary the injection speed with respect to the injection stroke.

■ Holding pressure switching position.

■How to vary the holding pressure during holding pressure.

There are factors such as.

[Problems to be Solved by the Invention] By the way, in conventional injection molding machines, it was not possible to directly see the inside of the heating cylinder, so the details of crosstalk and plasticization of the resin inside the heating cylinder were traditionally considered to be a black box. was. For this reason, in the past, it has been common to set the conditions during the charging stroke and injection stroke described above by a trial-and-error method based on similarities based on empirical values obtained through case studies.

In other words, since conventionally the inside of the heating cylinder could not be observed, (a) during plasticization metering (charging), the heated resin material was heated by the heater while being transferred by the screw;
How plasticization progresses: how it melts and changes from a solid phase to a fluid phase due to the shear force caused by screw rotation.

(b) Uniform plasticization after becoming a fluid phase.

(c) How the resin temperature rises inside the heating cylinder, that is, the resin temperature distribution.

(d) Whether the gas generated when the resin is melted and plasticized is properly degassed.

(e) Whether the resin that has become a fluid phase is stagnation while flowing forward between the valleys of the screw, or the flow rate.

(f) Movement of the check ring at the start of injection.

(g) Check the resin temperature distribution inside the tip of the heating cylinder during injection, especially whether there are any localized abnormal temperature rises.

Important checkpoints such as these are completely inside the black box, and it is impossible to observe or measure them and link them to controlling molding conditions.

On the other hand, attempts have been made to link molding condition settings through computer simulation calculations, but due to the rheological properties of plastics, flow analysis is not easy, and in the end access to the checkpoints mentioned above is almost impossible. The current situation is that we rely on experience. For this reason, even if you are skilled and have a wealth of experience, setting the optimal molding conditions is a slow and trial process, which takes time and effort.In addition, when an unexpected sudden change in molding conditions or an accident occurs, it is difficult to set the optimal molding conditions. It has been extremely difficult to quickly and accurately grasp this factor and the location (inside the heating cylinder) and deal with it.

The present invention was made in view of the above circumstances.

The aim is to provide a molding condition control method for injection molding machines that can feedback-control molding conditions based on the results of direct observation and analysis of resin behavior inside the heating cylinder. be.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention includes a heating cylinder in which a screw is arranged to be rotatable and movable back and forth, and a transparent body is arranged in a part of the peripheral wall of the heating cylinder. In a molding condition control method for an injection molding machine having a visualization heating cylinder provided with an internal amperage window, the surface of the resin inside the heating cylinder is measured through the observation window using a non-contact temperature tracer such as thermovision. Temperature distribution data is captured, and image data such as resin behavior is captured through the observation window using an imaging means such as a video camera, and the captured data is processed by an arithmetic and control device consisting of a microcomputer, for example. We measure and calculate the resin temperature difference within a predetermined area, the degree of bubble generation in the molten resin, the movement of the check ring, the plasticization state, etc., and based on this, we determine the conditions during the plasticization metering (charging) process and the injection process. be brought into control.

[Function] The arithmetic and control unit consisting of a microcomputer is
Temperature data and image data taken in through the observation window are processed by a pre-written calculation program. That is, for example, the temperature distribution of each part is calculated to calculate the temperature gradient and the presence or absence of abnormal temperature parts is calculated, and the image density distribution (m degrees, color distribution) is calculated and analyzed to detect air bubbles in the molten resin. degree of occurrence.

The degree of plasticization of the resin, the movement of the check ring, etc. are calculated and analyzed. The results of these calculations are compared with data stored as case studies in advance, and if the measured data exceeds the allowable range, the molding conditions are corrected to deal with this.

[Example] The present invention will be explained below using an example shown in FIGS. 1 to 8. Fig. 1 is a block diagram showing the components for controlling molding conditions, Fig. 2 is a partially cutaway front view showing the injection device of the injection molding machine, and Fig. 3 is a partially cutaway front view showing the main parts of the injection device. FIG. 4 is a front view of the main part, and FIG. 4 is a sectional side view of the main part, taken in a direction perpendicular to the axial direction of the heating cylinder.

First, the schematic structure of the injection device of the injection molding machine will be explained using FIG. In FIG. 2, 1 is a base, 2 is a support set on the base 1, and a head hook holding the rear end of the heating cylinder 3 is attached thereto. Reference numeral 4 denotes a screw, which is disposed in the heating cylinder 3 so as to be able to rotate and move back and forth, and is rotationally driven by a drive source 5 for screw rotation, and its forward and backward movement is controlled by a drive source 6 for injection. There is. In addition, 7 is a drive transmission mechanism disposed between the rear end of the screw 4 and the surface drive sources 5 and 6, 8 is a hopper for supplying resin material to the heating cylinder 3, and 9 is a drive transmission mechanism for supplying the heating cylinder 3. A band heater 10 for heating is a nozzle attached to the tip of the heating cylinder 3.

The resin material supplied from the hopper 8 to the rear part of the screw 4 in the heating cylinder 3 is mixed and plasticized by the rotation of the screw 4 and transferred forward, and as the molten resin is stored at the tip side of the screw 4, the resin material is 4 retreats while the back pressure is controlled, and when one shot of molten resin is stored on the tip side of the screw 4 (at the end of metering), the rotation of the screw 4 is stopped. and,
At the injection start timing after a predetermined time, the screw 4 is advanced, and the molten resin is injected and filled from the nozzle 10 into the cavity of a mold (not shown).

Although not shown in FIG. 2, the injection drive source 6 is equipped with a known injection pressure sensor consisting of a pressure head, etc., which measures the back pressure during the charging stroke and the injection pressure during the injection stroke. , to detect the holding pressure. Also, although not shown, a member that moves back and forth integrally with the screw 4 is provided with a known injection stroke sensor consisting of an encoder, etc., to detect the position and stroke of the screw. Ori.

Measurement information from the injection pressure sensor and elbow extension stroke sensor is sent to an arithmetic and control device, which will be described later.

Next, the structure around the heating cylinder 3 will be explained with reference to FIGS. 3 and 4.

As shown in FIG. 3, the rear end of the heating cylinder 3 is attached to a headstock 11 fixed to the support base 2.

It is fixed via a mounting plate 12. A circular hole 13 having a circular cross section is continuously bored in the peripheral wall of the heating cylinder 3 along the axial direction from the front end side (left side in the drawing) toward the rear end side. In this embodiment, the circular hole 13 is formed so as not to be completely penetrated to the rear end side.
The circular hole 13 may completely penetrate the peripheral wall of the heating cylinder 3 in the axial direction.

As shown in FIG. 4, two slits 14, 14 are formed in communication with the circular hole 13 at the top and bottom in the figure. Part 2
The two slits 14.14 are located on the extension line of the diameter of the circular hole 13, and similarly to the circular hole 13, they are continuously bored along the axial direction from the front end side to the rear end side of the heating cylinder 3. . Note that the circular hole 13 and the slit 14 are formed by wire cutting, for example.

As shown in FIGS. 3 and 4, on the outer surface side of the peripheral wall of the heating cylinder 3, a plurality of elongated observation windows 15 extending along the axial direction from the outer surface of the peripheral wall to the circular hole 13 are formed by, for example, end milling. It is perforated. In this embodiment, three observation windows 15 are provided corresponding to the feed zone, compression zone, and metering zone of the screw 4, respectively. The number of lA15 is arbitrary. (Note that this observation window 15 is formed in the non-wrapped portion of the band heater 9.) Also, on the inner surface of the peripheral wall of the heating cylinder 3, there is an axial direction extending from the inner surface of the peripheral wall to the circular hole 13. A plurality of elongated notches 16 are bored along the line. This notch 16 is bored at a position corresponding to the fifth observation window 15 so as to have substantially the same length as the axial length of the observation window 15, for example, by end milling at the same time as the observation window 15.

Reference numeral 17 denotes a cylindrical glass body 1 inserted into the circular hole 13 of the heating cylinder 3, which is made of, for example, transparent heat-resistant, high-strength, high-purity quartz glass, and its cross section matches the cross-sectional shape of the circular hole 13. is set to. In this embodiment, three glass bodies 17 are sequentially inserted into the circular hole 13 from the front end side open part of the heating cylinder 3 with a spacer 18 interposed between the glass bodies 17, and the glass bodies 17 on the front end side are The end face is pressed by a pressure contact means (not shown, for example, a nut) via a spacer 18 as necessary. As a result, each glass body 17 is positioned and fixed without loosening in the axial direction.

In this embodiment, the spacer 18 is made of a stone-based material with appropriate elasticity, but it may also be made of materials with heat resistance and appropriate elasticity (for example, copper, brass, etc.). ) can be selected.

Reference numeral 19 denotes a plurality of screw holes drilled above and below the observation window 15, and the screw holes 19 are formed perpendicularly to the slit 14 and penetrating through the slit portion, as shown in FIG. ing. This screw hole 19 has a female thread carved in the inner part that penetrates the slit part, and a screw (bolt) 20 is screwed and fastened into the female thread, thereby,
A force is applied in a direction to narrow the slit 14. As a result, the inner surface of the circular hole 13 wraps around and fastens the outer circumferential surface of the glass body 17, making a perfect seal.

In this embodiment adopting the above configuration, each observation window 15
Not only can the behavior of the resin in the feed zone, compression zone, and metering zone described above inside the heating cylinder 3 be observed through the glass body 17, but since the glass body 17 is cylindrical, the glass body 17 is a convex lens. Functions as a ll to expand resin behavior! This improves visibility. Further, since the glass body 17 is cylindrical, the pressure of the resin inside the heating cylinder 3 prevents the glass body 17 from being pressed against the inner surface of the outer side of the circular hole 13 even if it receives force. Since the circular arc surfaces of the glass body 17 are pressed against each other, the pressing force is dispersed and the glass body 17
No local stress is applied to the glass body 17, and breakage of the glass body 17 is prevented as much as possible. This also applies to thermal stress, and the tightening is similar to the stress caused by the screws 20, and the stress is spread almost evenly, so that the glass body 17 is guaranteed to have a long life without any risk of breakage.

Furthermore, due to the sealing effect of the screw 20, there is no risk of resin leakage.

In this embodiment, a cylindrical glass body 17 is used, but it may be a prismatic one, and in some cases, sapphire or the like may be used instead of the glass body 17. In this case, since sapphire is expensive, l! Observation window 1
5 is set small.

Furthermore, although three observation windows 15 are provided in this embodiment, their number, formation location, etc. are arbitrary.

FIG. 1 is a block diagram mainly showing a configuration for photographing and analyzing resin behavior, resin temperature, etc. in each zone in the heating cylinder 3 through the observation window 15 and controlling molding conditions.

In the figure, 30 is a video camera equipped with a solid-state image pickup device, an image pickup tube, etc. installed opposite the observation window 15;
Reference numeral 31 designates a strobe light emitting unit installed opposite the same <am window 15, and is controlled to emit light by a strobe controller 32 that receives a synchronization signal from the video camera 30. The image taken by the video camera 30 is first recorded on a video tape recorder (hereinafter referred to as VTR) 33, and this image data is taken into a data buffer 34 and then
The signal is converted into a digital signal by the /D converter 35 at an appropriate sampling rate, and sent to an arithmetic and control unit to be described later. In addition, 36 is VTR.

A monitor consisting of a color CRT display connected to 33 allows the operator to check the images taken by the video camera 30 if necessary.

A thermovision 37 is installed opposite the observation window 15 and is equipped with a temperature detector such as HgCdTe or InSb, and captures the temperature of the resin in contact with the observation window 15 as image data and records it on the VTR 38. It looks like this. The image data recorded on the VTR 38 is taken into a data buffer 39, then converted into a digital signal by an A/D converter 40 at an appropriate sampling rate, and sent to an arithmetic and control unit to be described later. In addition, 4
Reference numeral 1 denotes a monitor consisting of a color CRT display connected to the VTR 38, so that the temperature distribution image captured by the thermovision 37 can be directly viewed by the operator if necessary.

Note that the video camera 30. Both of the thermovisions 37 have a zoom function, and are provided with a turning table or the like, if necessary, although not shown.

Further, in this embodiment, as described above, the a detection window 15
Since three observation windows 15 are provided, when observing three observation windows 15 at the same time, a plurality of video cameras 30, thermovisions 37, etc. are arranged accordingly, and each observation window 1
5, the video camera 30, thermovision 37, etc. are moved each time to a position facing the observation window 15 that requires observation.

42 is an arithmetic control unit that controls the entire injection molding machine, and has an analysis function to analyze data obtained from the video camera 30 and thermovision 37, and a function to variably control molding conditions based on this. 1 For example, frame buffer 43, temperature distribution calculation means 441, image density distribution calculation means 45, molding condition calculation control means 46, data storage section 47
, a condition calculation table 48, and the like.

From the thermovision 37, a VTR 38, a data buffer 39 . Arithmetic control device via A/D converter 40! 4
The image data sent to frame buffer 4 is sent to frame buffer 4.
3 and then supplied to the temperature distribution calculation means 44, which calculates the resin temperature distribution in each zone within the heating cylinder 3 based on this data.

Further, the temperature distribution calculating means 44 refers to the contents of the data storage section 47 in which appropriate (normal) temperature distribution information that has been case studied in advance is stored, and determines whether the temperature of each part is within the set range. , whether the temperature gradient is within an allowable range, whether there is an abnormal temperature occurrence site, etc.

In addition, when the importance of the abnormal temperature state is high, the temperature distribution calculation means 45 drives an alarm generating device (not shown),
An alarm message is displayed on a display device to be described later, and in some cases, the molding condition calculation control means 46 or the like is used to bring the machine to an emergency stop.

The image data sent from the video camera 30 to the arithmetic and control unit 42 via the VTR 33, data buffer 34, and A/D converter 35 is similarly once stored in the frame buffer 43, and then converted into the image density distribution. Arithmetic means 4
The 0 image density distribution calculation means 45 supplied to 5 at a predetermined timing calculates the luminance distribution and 1 color distribution based on this data, and calculates the degree of bubble generation due to the gas generated when the resin is melted, the in-phase (resin pellet ) and the fluid phase due to the difference in brightness, etc., and the degree of distribution of the solid phase-liquid phase, check ring (
The behavior of the known check valve member attached to the tip neck of the screw 4, the degree of mixing of the coloring agent mixed into the resin, etc. in some cases, etc., can be determined by bubble identification stored in the data storage section 47 in advance. information, solid phase-fluid phase identification information, check ring identification information, coloring density identification information, etc. Further, the image density distribution calculation means 45 calculates the appropriateness (
Determine whether the above calculation results are within the allowable range by referring to bubble generation frequency information (normal), appropriate solid phase-liquid phase distribution information, appropriate check ring behavior information, appropriate coloring density distribution information, etc. Processing is also carried out, and if the comparison result determines that the abnormal situation is of high importance, it will generate or display a warning sound or an alarm message as before, and in some cases, it will cause the machine to come to an emergency stop.

Here, the data storage unit 47 contains the aforementioned appropriate (normal) temperature distribution information, appropriate bubble generation frequency information, which is case studied in advance for each screw 4 used and for the type of resin material used. Appropriate solid phase-liquid phase distribution information, appropriate check ring behavior information, appropriate coloring density distribution information, etc. are stored. Then, in the temperature distribution calculation means 44 and the image density distribution calculation means 45, the measurement analysis data obtained by processing the image data captured by the thermovision 37 or the video camera 30, and the data storage section 47
The comparison result with the appropriate data stored in is sent to the molding condition calculation control means 46.

Of course, the measurement and analysis data from the temperature distribution calculation means 44 and the image density distribution calculation means 45 and the appropriate data stored in the data storage section 47 are used by the molding condition calculation control means 46.
may be taken in and compared.

The condition calculation table 48 stores conversion calculation reference data that is a detailed case study of the relationship between image data and molding conditions, for example.

The relationship between temperature distribution information, bubble generation frequency information, solid phase-liquid phase distribution information, check ring behavior information 1 coloring density distribution information, etc., and the molding conditions listed below are stored.

In other words, these molding conditions were conventionally set by trial and error using only empirical values from case studies without referring to the details of kneading and plasticizing the resin in the heating cylinder. While changing these molding conditions in a fixed procedure, temperature distribution information, bubble generation frequency information, in-phase
In order to obtain the best fluid phase distribution information, check ring behavior information, coloring density distribution information, etc., the conditions are stored in the condition calculation table 48, which are set based on the actual measurement data from the visualization cylinder.

Molding conditions ■Heater temperature of each zone.

■Measuring stroke.

■How to vary the screw rotation speed with respect to the four strokes.

, ■ How to vary the back pressure with respect to the metering stroke.

■Amount of suckback and its speed.

■Injection pressure.

■How to vary the injection speed with respect to the injection stroke.

■ Holding pressure switching position.

■How to vary the holding pressure during holding pressure.

The molding condition calculation control means 46 includes temperature distribution calculation means 4
4. Calculate and set optimal molding conditions with reference to the contents of the condition calculation table 48 based on the comparison data between the measurement data by the image density distribution calculation means 45 and the appropriate data stored in the data storage section 47 .

In addition, measurement information from an injection stroke sensor 49, an injection pressure sensor 50, etc. is suitably converted and input to the molding condition calculation control means 46 in the form of injection stroke, injection speed, and injection/holding pressure. Further, although not shown, a clock built into the arithmetic processing unit 42 allows the counting time from the reference time of each molding cycle to be recognized. Then, the molding condition calculation control means 46 refers to the stroke, speed, and pressure at each point in time.

Based on the optimum molding conditions calculated as described above, the screw rotation drive source 5. The injection drive source 6, band heater 9, etc. are driven and controlled to control the above-mentioned molding conditions (1) to (2).

Note that the arithmetic and control unit i1!42 having the above-mentioned functional units is actually a microcomputer, and has various I10 interfaces.

ROM that stores clocks, main programs, fixed data, etc., various flags, and measurement data.

It is equipped with a RAM for reading and writing conversion processing data, etc., a μCPU (micro central processor unit) for overall control, etc., and it is obvious to those skilled in the art that each of the above-mentioned functions is realized by a program created in advance. Will. Further, the results of the arithmetic processing of the arithmetic control bag [42] are sent to output devices such as a display device 54 consisting of a color CRT display and a printer 55, as required, so that the operator can visually check the analysis results.

The arithmetic and control unit 42 is also connected to an external memory 56 such as a magnetic disk device, so that predetermined data can be exchanged as needed.

Next, several examples of methods for controlling molding conditions will be explained with reference to FIGS. 5 to 8.

FIG. 5 is a sectional view of the tip portion of the heating cylinder 3. In the figure, 4a is the tip head of the screw 4, 4b is the top, 4c is a screw thread, 57 is a check ring attached to the neck 4b, and 58 is the stored molten resin.

Said 18 indicated by the two-dot chain line in the figure! The inside of the heating cylinder 3 is observed through the observation window 15.I! It can be celebrated.

FIG. 6 is an explanatory diagram showing an image obtained by the thermovision 38 from the observation window 15 shown in FIG. In the figure, the temperature of region Z1 is Tl.

Assuming that the temperature of region z2 is T2 and the temperature of region z3 is T3, it can be seen that there is a relationship of TI>T2>T3, and the temperature distribution of the stored molten resin 58 is not uniform. It is desirable that the temperature distribution of the stored molten resin 58 is uniform, and the temperature distribution calculating means 44 calculates, for example, the average temperature T ave of the entire stored molten resin region and the temperature difference range R=
Tmax-Twin is calculated, and the molding condition calculation control means 46 calculates R/Tave so that it becomes the appropriate value held in the data storage section 47 (so that it becomes smaller).
Change and adjust the necessary factors among the molding conditions (1) to (2) described above. Note that the temperature distribution is detected in the other Ilt detection windows 15 in the same manner, and if there are abnormally high or abnormally low temperatures, the molding conditions are changed to deal with this.

FIG. 7 is an explanatory diagram showing another image obtained by the video camera 30 from the window 15 shown in FIG. The figure shows a known sack in which the pressure of the molten resin 58 is temporarily reduced by forcibly retracting the screw 4 by a minute amount after completion of metering in order to prevent the drooling phenomenon in which the molten resin 58 leaks from the nozzle 10. An image is shown when back control is performed. (For details of suckback control, if necessary, please refer to Japanese Patent Application No. 63-248958, which was previously proposed by the applicant.) In the same figure, 59 indicates air bubbles generated by reducing the resin pressure. The image density distribution calculating means 45 calculates the degree of occurrence of the bubbles 59.

This is compared with appropriate bubble generation frequency information during suckback control held in the data storage section 47.

It is desirable that the number of bubbles 59 caused by suckback be as small as possible, and it is also desirable that the pressure reduction value caused by suckback be constant for each cycle. The amount of suckback is controlled so that forced retraction of the screw 4 is stopped at the moment when the pressure is reduced (when a predetermined pressure reduction state is reached). As a result, suckback control, which has been unstable in the past, can be accurately controlled.

It should be noted that images showing the degree of generation of air bubbles 59 are similarly obtained from other wt detection windows 15.1 For example, it is possible to determine whether or not the gas generated when resin is melted and plasticized is successfully degassed at a predetermined location. This is determined based on the number of bubbles 59 generated, and if it is determined that the deaeration is insufficient, the charging conditions are changed by the molding condition calculation control means 46 to deal with this.

Furthermore, although not shown, the observation window 15 shown in FIG.
It is obvious that the image data showing the movement of the check ring 57 is obtained from this, and the behavior of the check ring 57 is determined by the image density distribution calculation means 45. It is desirable that the time t from the time of occurrence to the complete closing state is short, and the molding condition calculation control means 46 adjusts the amount of suckback, the initial injection speed, Calculate and control the holding pressure switching position, etc.

Figure 8 shows the melting start position of the resin material and the melting point where the resin reaches 100%.
FIG. 3 is a schematic explanatory diagram showing image data obtained from two observation windows 15 by two video cameras 30 to show the melting completion position of the melt.

In the same figure, 58 indicates a molten resin (fluid phase), 60 indicates a same phase resin, and 81 on the right side of the figure
indicates the melting start zone, and 82 on the left indicates the melting completion zone. In order to uniformly plasticize the resin, it is desirable that the melting start zone S1 and the melting completion zone S2 are constant, and the image density distribution calculating means 45 uses the measured and analyzed solid phase-liquid phase distribution data, The forming condition calculation control means 46 compares the appropriate solid phase-liquid phase distribution data held in the data storage section 47, and based on this, the melting start zone S1 and the melting completion zone S2 are set to be constant. to control charging conditions.

Although the present invention has been described in detail with reference to the illustrated embodiments, those skilled in the art will be able to make various modifications without departing from the spirit of the present invention, and the processing within the arithmetic and control unit 42 may be modified in various ways depending on the program created. It can take any form. In addition to the behavior of the resin that is analyzed using image data and used to control the molding conditions, in addition to those described in the embodiments described above, the flow rate of the resin, the state of mixing of the coloring material, etc. can be used. Also,
Although three observation windows 15 are provided in the embodiment, they may be provided only on the front end side of the heating cylinder 3, for example.

Furthermore, during the charging stroke, the screw 4 may be rotated and retracted while being vibrated back and forth by a minute amount, thereby making it possible to shorten the charging time and more finely control the molding conditions.

[Effects of the Invention] As mentioned above, according to the present invention, the molding conditions are controlled using the results of direct Wt analysis and analysis of the resin behavior inside the heating cylinder, so the molding conditions can be set accurately. This makes it possible to obtain high-quality molded products. In addition, even if an unexpected accident occurs, we can accurately identify the cause and
It will be possible to quickly understand and deal with the situation, etc.
This kind of in-line screw type injection molding machine.

It has a remarkable effect.

[Brief explanation of drawings]

The drawings all relate to one embodiment of the present invention, and FIG. 1 is a block diagram showing components for controlling molding conditions, FIG. 2 is a partially cutaway front view showing an injection device of an injection molding machine, and FIG. Figure 3 is a partially cutaway front view showing the main parts of the injection device;
The figure is a cross-sectional side view of the main part of the heating cylinder taken in a direction perpendicular to the axial direction. Fig. 5 is a cross-sectional front view of the tip of the heating cylinder, Fig. 6 is an explanatory drawing showing an image obtained by thermovision, Fig. 7 is an explanatory drawing showing the appearance of bubbles obtained by a video camera, and Fig. 8 The figure is an explanatory diagram schematically showing the distribution state of the in-phase-fluid phase of the resin obtained with a video camera. ■・・・Base, 2...Abutment, 3...
...Heating cylinder, 4...Screw, 4a
...Tip head, 4b...Neck, 4c.
...Thread thread, 5... Drive source for screw rotation, 6... Drive source for injection, 7... Drive transmission mechanism, 8...・Hopper, 9...
Band heater, 10...Nozzle, 11...
...Headstock, 12...Mounting plate, 13.
...Circular hole, 14...Slit, 15.
... Observation window, 16 ... Notch, 17 ...
... Glass body, 18 ... Spacer, 19.
...Screw hole, 20...Tighten with screw, 30
...Video camera, 31...3LRS from strobe, 32...Strobe controller 1-roller, 33...Video tape recorder, 34...
...Data buffer, 35...-A/D converter, 36...Monitor, 37...Thermovision, 38...Video tape recorder, 39
...Data buffer, 40...A/D
Converter, 41... Monitor, 42... Arithmetic control unit, 43... Frame buffer, 44
... Temperature distribution calculation means, 45 ... Image density distribution calculation means, 46 ... Molding condition calculation control means, 47 ... Data storage section, 48.・・・・・・
・Condition calculation table, 49...Injection stroke sensor, 5o...Injection pressure sensor, 51-5
3...driver, 54...display device,
55...................................Printer, 56...th...
・External memory, 57...Check ring, 58
...... Molten resin, 59... Bubbles, 60.
...Solid phase resin. Figure 5 Figure 6

Claims (6)

[Claims] (1) Injection molding with a visualization heating cylinder in which a screw is arranged in the heating cylinder so that it can rotate and move back and forth, and a part of the peripheral wall of the heating cylinder is provided with an observation window for internal observation with a transparent material. In the machine, image data such as the temperature distribution or behavior of the resin inside the heating cylinder is captured through the observation window, and molding conditions are controlled based on the analysis results of the captured data. A method for controlling molding conditions in an injection molding machine with a visualized heating cylinder. (2) In claim 1, the degree of generation of air bubbles in the molten resin is measured and calculated from the image data, and the molding conditions are controlled so that the degree of generation of air bubbles is below a permissible value. A method for controlling molding conditions in an injection molding machine having a visualized heating cylinder characterized by: (3) The visualized heating cylinder according to claim 2, characterized in that the forced retreat amount of the screw during the back-back control is controlled by the degree of generation of air bubbles generated in the molten resin stored on the tip side of the screw. A method for controlling molding conditions in an injection molding machine with (4) The visualized heating cylinder according to claim 1, wherein the behavior of a check ring for preventing backflow located at the neck on the tip side of the screw is analyzed from the image data to control molding conditions. A method for controlling molding conditions in an injection molding machine with (5) In claim 1, the melting start position of the resin and the melting completion position where the resin is 100% melted are analyzed from the image data, and the melting start position and the melting completion position are always constant. 1. A method for controlling molding conditions in an injection molding machine having a visualized heating cylinder, characterized in that the molding conditions are controlled in accordance with the invention. (6) In claim 1, the temperature difference of the resin within a predetermined region is calculated from the temperature distribution data, and the molding conditions are controlled so that the resin temperature within the predetermined region is averaged. A method for controlling molding conditions in an injection molding machine with a distinctive visualization heating cylinder.