JPH0647266B2 - Molding condition analysis method for injection molding machine with visualization heating cylinder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a molding condition analysis method in an inline screw type injection molding machine having a visualization heating cylinder, and more particularly to a resin in a heating cylinder containing a screw. Observation of behavior etc. through the observation window provided in the heating cylinder
The present invention relates to a molding condition analysis method in an injection molding machine, which analyzes and analyzes molding conditions.

[Prior Art] In an in-line screw type injection molding machine, in order to stably and continuously obtain a molded product of good quality, conditions regarding plasticization measurement (charge) and injection of a resin material are essential.

Of course, the shape design of the screw is also important as a prerequisite, and (a) the composition ratio of the screw supply part (feed zone), compression part (compression zone), and weighing part (metering zone).

(b) L / DL L: total length of screw D: diameter of screw (c) compression ratio (CR = h1 / h2) h1: depth of screw groove in supply part h2: depth of screw groove in measuring part (raw material supply part The ratio of the amount of resin accumulated in the screw groove of No. to the amount of resin accumulated in the screw groove of the measuring unit.) (D) P / DP P: Screw pitch of screw D: Full consideration of the diameter of screw The screen design is determined based on this, and the quality of the plasticization measurement is determined based on this.

Strictly speaking, the optimum screw shape is determined for each resin to be molded, but generally, a general-purpose screw design that can be commonly used for as many resin materials as possible is selected. That is, in (a) above, the length of the normal supply unit is set to 5
Stabilize the charge speed by increasing it to 0-60%,
Consideration is given so that the resin is not pressed as much as possible until the temperature rise melting point is reached, and the shear heat generation is controlled by the length of the compression section. In addition, in (b) above, the longer the L / D, the better the charge speed, the resin temperature, and the stability of the kneading.
D is usually 20-22. Further, in the above (c), when low temperature molding is required, CR is made small to suppress shear heat generation in the kneading section, and conversely, CR is made large in order to improve kneading property. Furthermore, the value P / D of (d) is usually selected to be a value of about 1.0 in consideration of the transfer amount and the efficiency in the molten state.

In addition to this, the wall thickness / outer diameter of the heating cylinder is also important in that the heat from the heater is stably transmitted.

The design of the above-mentioned screen is based on past experience values.
The calculation is performed by the computer, but as described above, the screw is generally a general-purpose screw applicable to a wide variety of resin materials, and an in-line type injection molding machine having such a screw, The molding conditions under which the equipment is operated depending on the resin material are extremely important matters.

These molding conditions include the heater temperature of each zone during plasticization measurement (charge).

Weighing stroke.

How to change the screw speed to the measuring stroke.

How to vary the back pressure with respect to the measuring stroke.

The amount and speed of the crack.

There are also factors such as the injection pressure at the time of injection.

How to change the injection speed with respect to the injection stroke.

Holding pressure switching position.

How to change the holding pressure during holding pressure.

There are such factors.

[Problems to be Solved by the Invention] By the way, in the conventional injection molding machine, the inside of the heating cylinder could not be directly seen. Therefore, the above-mentioned condition setting at the charge stroke and the injection stroke was a trial based on an empirical value. With the method of error, the molded product was observed by a trial shot and the molding conditions were searched for.

That is, since the inside of the heating cylinder cannot be observed in the past, (a) during plasticization measurement (charge), while being transferred by the screw, the heated resin material is heated by the heater, and due to the shearing force due to the screw rotation, How to proceed with melt plasticization, which is how to melt and go from the solid phase to the fluid phase.

(B) State of uniform plasticization after reaching the fluid phase.

(C) How the resin temperature rises inside the heating cylinder,
That is, the presence or absence of resin temperature distribution and abnormal temperature parts.

(D) Whether the gas generated when the resin is melted and plasticized is well degassed.

(E) Whether or not the resin that has become the fluid phase stays in the valley of the screw when advancing, or the fluid velocity.

(F) The movement of the check ring at the start of injection.

(G) Uniformity of resin coloring when a colorant is mixed.

It was impossible to link the important check points such as the above with the setting of the molding conditions by observing and measuring them at all in the black box.

On the other hand, attempts have been made to link molding conditions to computer simulation calculations, but due to the rheological characteristics of plastics, flow analysis is not easy and, in the end, access to the above-mentioned checkpoints is almost impossible. Currently, it depends on cans and experience, and setting optimal molding conditions requires skill and abundant experience, and it takes time and effort. However, in recent plastic industries, the types and blending of resin materials are becoming more complex and sophisticated, and instead of the conventional setting of molding conditions by trial and error, setting more theoretical molding conditions. The momentum for a method is increasing.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to set more theoretical molding conditions based on the result of direct observation and analysis of resin behavior inside a heating cylinder. A method of analyzing molding conditions in an injection molding machine is provided.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has a screw arranged in a heating cylinder so as to be rotatable and forward / backward, and a translucent body is arranged on a part of a peripheral wall of the heating cylinder. In a molding condition analysis method in an injection molding machine having a visualization heating cylinder provided with an observation window for internal observation, a resin inside the heating cylinder is passed through the observation window by a non-contact type temperature tracer such as thermovision. Surface temperature distribution data of the above, and image data such as resin behavior through the observation window by an image pickup means such as a video camera, and the acquired data is processed by an analysis and arithmetic unit composed of a micro computer. For example, the resin temperature difference in a predetermined region, the degree of solid phase-particle size phase distribution, the degree of bubble generation in the molten resin, the plasticized and melted resin. The flow rate of the marker in the fat material, the coloring degree of the resin material, the movement of the check ring, etc. are measured and calculated, and the conditions during the plasticization measurement (charge) process and the injection process are analyzed based on this. It

[Operation] The analysis calculation device including the microcomputer performs calculation processing on the temperature data and the image data taken through the observation window by a calculation program created in advance. That is, for example, the temperature distribution of each part is calculated to calculate the temperature gradient and the presence or absence of an abnormal temperature part is detected, and the image density distribution (luminance, color distribution), marker flow velocity (resin flow velocity), check Performing operational analysis of ring behavior, etc., the degree of solid phase-fluid phase distribution, the degree of bubble generation in the molten resin,
The flow of markers in the plasticized and melted resin material, the degree of coloring of the resin material, the movement of check ring, etc. are analyzed. These calculation results are stored together with the above-mentioned setting conditions at the time of the charge and the injection process, the type of resin material used, the screw design, etc., and are most suitable for each resin determined by variously changing the molding conditions. The molding conditions are found.

[Embodiment] The present invention will be described below with reference to an embodiment shown in FIGS. 1 to 9. FIG. 1 is a block diagram showing components for analyzing molding conditions, FIG. 2 is a partially cutaway front view showing an injection device of an injection molding machine, and FIG. 3 is a part showing an essential part of the injection device. FIG. 4 is a front view of the main part cut, and FIG. 4 is a side view of the main part cut in the direction orthogonal to the axial direction of the heating cylinder.

First, the schematic configuration of the injection device of the injection molding machine will be described with reference to FIG. In FIG. 2, 1 is a base, 2 is an abutment installed on the base 1, and a headstock holding the rear end of the heating cylinder 3 is attached. Reference numeral 4 denotes a screw, which is arranged in the heating cylinder 3 so as to be able to rotate and move back and forth, and is rotationally driven by a screw rotation drive source 5 and is controlled by an injection drive source 6 to move back and forth. It is becoming like this. Reference numeral 7 is a drive transmission mechanism arranged between the rear end of the screw 4 and the drive sources 5 and 6, 8 is a hopper for supplying a resin material to the heating cylinder 3, and 9 is a heating cylinder 3 A band heater 10 for heating the heating cylinder 10 is a nozzle attached to the tip of the heating cylinder 3.

The resin material supplied from the hopper 8 to the rear portion of the screw 4 in the heating cylinder 3 is kneaded and plasticized by the rotation of the screw 4 and is transferred to the front side, and the molten resin is stored on the tip side of the screw 4. Accordingly, the screw 4 is retracted while the back pressure is controlled, and the rotation of the screw 4 is stopped at the time when one shot of molten resin is stored at the tip side of the screw 4 (at the end of the measurement). And
At the injection start timing after a lapse of a predetermined time, the screw 4 is advanced so that the molten resin is injected and filled from the nozzle 10 into the cavity of the mold (not shown).

In the embodiment, the screw 4 is rotated in the forward and reverse directions during the charge stroke (for example, the forward rotation period 3 is opposite to the reverse rotation period 1).
It is also possible to rotate the screw while vibrating the screw during the charge stroke, which increases the number of charge condition setting items to increase the variation of the charge condition, and it is also fine. It is possible to control. (For the former forward / reverse rotation charge, the applicant of the present invention has previously proposed Japanese Patent Application No. 63-177.
No. 128, and the latter rotary charge with vibration, the Japanese Patent Application No. 63-
No. 177129, if necessary, respectively. ) Next, the structure in the vicinity of the heating cylinder 3 will be described with reference to FIGS. 3 and 4.

As shown in FIG. 3, the rear end of the heating cylinder 3 is fixed to a headstock 11 fixed to the abutment 2 via a mounting plate 12. On the peripheral wall of the heating cylinder 3, a circular hole 13 having a circular cross section is continuously bored from the front end side (the left side in the drawing) toward the rear end side along the axial direction. In the embodiment, the circular hole 13 is formed so as not to completely penetrate to the rear end side.
May completely penetrate the peripheral wall of the heating cylinder 3 in the axial direction.

As shown in FIG. 4, two slits 14 and 14 are formed in the upper and lower portions of the drawing so as to communicate with the circular hole 13. The 2
The three slits 14 and 14 are located on the extension line of the diameter of the circular hole 13, and like the circular hole 13, are continuously bored from the front end side to the rear end side of the heating cylinder 3 along the axial direction. . The circular hole 13 and the slit 14 are formed by wire cuts, for example.

As shown in FIGS. 3 and 4, on the outer surface side of the peripheral wall of the heating cylinder 3, an elongated observation window 15 extending in the axial direction from the outer surface of the peripheral wall to the circular hole 13 is provided by, for example, end milling. A plurality of holes are drilled. In this embodiment, three observation windows 15 are provided corresponding to the feed zone, the complex zone and the metering zone of the screen 4, but the number of observation windows 15 is arbitrary. (Note that the observation window 15 has the band heater 9
Is formed on the unwound portion. ) Further, on the inner surface side of the peripheral wall of the heating cylinder 3, the circular hole 1 is formed from the inner surface of the peripheral wall.
A plurality of elongated notches 16 is formed along the axial direction reaching 3. The notch 16 is formed at a position corresponding to the observation window 15 by, for example, end milling at the same time as the observation window 15 so that the notch 16 has substantially the same length as the axial length of the observation window 15.

Reference numeral 17 is a cylindrical glass body inserted in the circular hole 13 of the heating cylinder 3, and is made of, for example, transparent heat-resistant and 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, the three glass bodies 17 are sequentially inserted into the circular hole 13 from the front end side open portion of the heating cylinder 3 through the spacers 18 between the glass bodies 17 so that 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 tightening nut) via the spacer 18 if necessary. As a result, each glass body 17 is positioned and fixed in the axial direction without slack. In the embodiment, the spacer 18 is made of an asbestos-based material having an appropriate elasticity, but in addition to this, a material having heat resistance and an appropriate elasticity (for example, copper, brass, etc.) Any one can be selected from.

Reference numeral 19 is a plurality of screw holes formed in the upper and lower portions of the observation window 15, and the screw holes 19 are formed so as to be orthogonal to the slit 14 and penetrate the slit portion as shown in FIG. ing. A female screw is engraved in the screw hole 19 at a rear portion penetrating the slit portion, and a tightening screw (bolt) 20 is screwed and fastened to the female screw, whereby
A force in the direction of narrowing the slit 14 is applied. As a result, the inner surface of the circular hole 13 holds and fastens the outer peripheral surface of the glass body 17 to complete the seal.

In the embodiment having the above-mentioned configuration, each observation window 15
From the above, it is possible not only to observe the resin behavior of the above-mentioned feed zone, compression zone and metering zone in the heating cylinder 3 through the glass body 17, but since the glass body 17 has a columnar shape, By functioning as a convex lens, the behavior of the resin can be enlarged and can be observed, thereby improving the visibility. Further, since the glass body 17 has a cylindrical shape, the resin pressure inside the heating cylinder 3 causes the glass body 17 to be pressed against the inner surface on the outer side of the circular hole 13 even if the glass body 17 is pressed against the inner surface of the circular hole 13. Since the circular arc surfaces of the glass body 17 and the glass body 17 are pressed against each other, the pressing force is dispersed and no local stress is applied to the glass body 17, and the glass body 17 is prevented from being damaged as much as possible. This also applies to the thermal stress and the stress caused by the tightening screw 20, and the stress is substantially evenly diffused so that the glass body 17 is guaranteed to have a long life without being damaged. Furthermore, due to the sealing effect of the tightening screw 20,
There is no risk of resin leakage.

Although the cylindrical glass body 17 is used in the embodiment, it may be a prismatic glass body, and in some cases, the glass body 17 may be replaced with sapphire or the like. , In this case, the sapphire is expensive, so the observation window 15
Is set small. Furthermore, in this embodiment, three observation windows 15 are provided, but the number of them, the 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 from the observation window 15.

In the figure, 30 is a video camera equipped with a solid-state image pickup device, an image pickup tube, and the like, which are installed to face the observation window 15,
Reference numeral 31 is a stroboscopic light emitting portion similarly installed opposite to the observation window 15, and the light emission is controlled by a stroboscopic controller 32 which receives a synchronization signal from the video camera 30. The image photographed by the video camera 30 is once recorded on a video tape recorder (hereinafter referred to as VTR) 34, and this image data is taken into a data buffer 35, and then A
The signal is converted into a digital signal by the / D converter 36 at an appropriate sampling rate, and is sent to the analysis calculation device described later. Incidentally, 37 is a color C connected to the VTR 34.
An image captured by the video camera 30 can be confirmed by an operator as necessary on a monitor including an RT display.

Reference numeral 38 is a thermovision installed opposite to the observation window 15 and equipped with a temperature detector such as HgCdTe or InSb. The resin temperature in contact with the observation window 15 is captured as image data and is temporarily recorded in the VTR 39. It has become. Then, the image data recorded in the VTR 39 is taken into the data buffer 40, converted into a digital signal at an appropriate sampling rate by the A / D converter 41, and sent out to the analysis calculation device described later. . 4
Reference numeral 2 is a monitor composed of a color CRT display connected to the VTR 39, and the operator can directly visually recognize the temperature distribution image captured by the thermovision 38 if necessary.

The video camera 30 and the thermovision 38 both have a zoom function, and are provided with a swivel turntable and the like (not shown) if necessary. Further, in this embodiment, since the three observation windows 15 are provided as described above, when observing the three observation windows 15 at the same time, a plurality of video cameras 30, thermovisions 38, etc. are correspondingly provided. When a table is provided and each observation window 15 is individually shifted in time for observation, the video camera 30, the thermovision 38, etc. are moved to a position facing the observation window 15 requiring observation each time. .

Reference numeral 43 is an analysis calculation device for analyzing the data obtained from the video camera 30 and the thermovision 38, and includes a frame buffer 44, a temperature distribution calculation means 45, an image density distribution calculation means 46, a flow velocity calculation means 47, and a check ring. Behavior calculation means 48, data storage 49, table 50,
A molding condition calculation unit 51 and the like are provided.

From the thermovision 38, a VTR 39, a data buffer 40, an A / D converter 41, and an analysis calculation device 43.
The image data sent to the
After being stored in the temperature distribution calculating means 45, the temperature distribution calculating means 45 calculates the resin temperature distribution of each zone in the heating cylinder 3 based on this data. Further, the temperature distribution calculating means 45 refers to the contents of the table 50 in which the case distribution temperature distribution information stored in advance is stored, and determines whether the temperature of each part is within the set range and the temperature gradient is within the allowable range. Whether or not it is inside, or whether or not there is an abnormal temperature occurrence site, etc., is discriminated.

The image data sent from the video camera 30 to the analysis calculation device 43 via the VTR 34, the data buffer 35, and the A / D converter 36 is once stored in the frame buffer 44 in the same manner, and then the image density distribution is obtained. Computing means 4
6, are supplied to the flow velocity calculating means 47 and the checking behavior calculating means 48 at predetermined timings. The image density distribution calculation means 46 calculates the luminance distribution and the color distribution,
The degree of distribution of the solid-fluid phase due to the difference in brightness between the solid phase (resin pellet) and the fluid phase, the degree of generation of bubbles due to gas generated when the resin is melted, the degree of distribution of markers mixed in the resin, The degree of mixing of the colorant mixed in the resin is calculated with reference to the solid phase-fluid phase identification information, the bubble identification information, the marker identification information, the coloring concentration identification information, etc. stored in advance in the table 50. To do. Further, the image density distribution calculation means 46 also refers to the allowable range information stored in the table 50 in advance as a case study, and also executes a determination process such as whether or not the above calculation result is within the allowable range.

The flow velocity calculation means 47 processes the supplied image data of a plurality of frames, refers to the marker identification information stored in advance in the table 50, and determines the flow rate of the resin from the flow velocity of the marker mixed in the resin. Velocity is calculated for each site. In addition, by this, the presence or absence of resin retention points,
Calculate and determine the staying position and size of staying place. Further, the flow velocity calculation means 47 also uses the table 50.
Also, by referring to the allowable range information and the like stored as a case study in advance, a determination process such as whether the above calculation result is within the allowable range is also executed.

The check ring behavior calculation means 48 stores in advance the movement of a known check ring (check valve member) mounted on the distal neck portion of the screen 4 in the table 50 from the supplied image data of a plurality of frames. The calculation is performed by referring to the check ring identification information. Further, the checking behavior calculation means 48 refers to the checking behavior allowable range information stored in the table 50 in advance as a case study to determine whether the checking is at a predetermined operating position at a predetermined timing. Then, a determination process such as whether or not the above calculation result is within the allowable range is also executed.

The calculation processing results of the temperature distribution calculating means 45, the image density distribution calculating means 46, the flow velocity calculating means 47, and the checking behavior calculating means 48 described above are taken into the data storage section 49. Further, in the data storage section 49, details of the above-mentioned screw design regarding the screw 4 used, the type of resin material used, and the above-mentioned charge and setting condition (molding setting condition) at the time of injection process, that is, , Heater temperature of each zone (nozzle part, front, middle, rear of cylinder, under hopper).

Weighing stroke.

How were the screw speed and back pressure varied with the measuring stroke?

Time ratio of forward / reverse rotation of the screw.

Vibration intensity and frequency to be superimposed on the rotation.

The amount and speed of the crack.

Injection pressure magnitude and rise time.

How the injection stroke and injection speed were changed with respect to the injection stroke.

Holding pressure switching position.

How was the holding pressure during holding pressure varied?

Information is also stored together. It should be noted that these pieces of information are achieved by an input operation using a key input device (not shown) or by supplying information from a control device 52 which is a micro computer that controls the entire injection molding machine.

The data storage unit 49 sequentially stores the calculation results of the above-described calculation means 45 to 48 when the molding setting conditions are changed and the test shot is repeated. Then, each computing means 45-
The above-mentioned molding conditions ~ when the calculation result of 48 shows the most preferable state are stored in a predetermined storage area as optimum molding conditions.

For example, the resin material is sequentially changed to, for example, polycarbonate, acrylic, styrene, or the like for each shape design of the screw and the heating cylinder, and the charge amount is changed by 10% between 10 and 100% for each resin material. The results of case studies of the above-mentioned molding conditions 1 to 3 are stored in a predetermined storage area as optimum molding conditions.

The molding condition calculation unit 51 refers to the optimum molding condition data for each resin stored in the data storage unit 49, and when molding an unanalyzed new resin, the molding condition is calculated based on the known molding condition of the approximate resin material. Is calculated and set,
The molding conditions are calculated so as to bring the molding conditions of the unanalyzed resin close to the optimum value with reference to the above-mentioned processing results from the image data obtained by trial-testing the unanalyzed resin. The calculation result by the molding condition calculation unit 51 is sent to the control device 52 of the injection molding machine, whereby the molding condition is variably set.

The analysis and operation unit 43 having the functional units described above is actually composed of a microcomputer, and various I / O interfaces, ROMs storing main programs and fixed data, various flags and measurement. It is equipped with a RAM for reading and writing data, conversion processing data, and the like, a μCPU (micro central processor unit) for controlling the entire control, and the above-described functions cannot be realized by a program created in advance. It will be obvious to those skilled in the art. Further, the calculation processing result of the analysis calculation device 43 is sent to an output device such as a display device 53 and a printer 54, which are made of a color CRT display, if necessary, so that the operator can visually recognize the analysis result. The analysis / calculation device 43 is also connected to an external memory 55 such as a magnetic disk device, and exchanges predetermined data as necessary.

Next, several examples of a method of analyzing molding conditions will be described with reference to FIGS.

5 (a), (b) and (c) show the observation window 15 of the heating cylinder 3.
It is explanatory drawing which shows the image acquired by the said video camera from. In each of the figures, the solid phase-fluid phase distribution of the resin is shown, with the white spots 56 in the figure indicating the solid phase, and the dots 57 shown in the figure indicating the fluid phase. In addition, the figure shows all the complex zones.
In the order of (a), (b), and (c), appropriate parts on the downstream side in the resin feeding direction are picked up. In order to achieve good melt plasticization, the same figure should be used at the end of the compression zone.
As in (c), it is desirable that 100% melting is completed, the melting completion position is stable, and the melting start position is stable. Further, it is desirable that the melting does not proceed too early or too late and the melting rate is constant and gradually progresses between the melting start position and the melting completion position.

Therefore, the image density distribution calculation means 46 subdivides the compression zone and refers to the ratio of the solid phase to the fluid phase at each site, and the molding condition calculation part 51 determines that the measurement data is not appropriate. Is stable at the melting start position and the melting completion position, and the melting is not too early or too late between both positions, and the melting rate is constant so that the melting rate is constant and gradually progresses. Change and adjust the required factor.

FIG. 6 is a sectional view of the tip portion of the heating cylinder 3. In the figure, 4a is the tip of the screw 4, 4b is a neck, 4c is a screw thread, and 58 is the neck 4b.
The check ring 57 attached to the part shows the stored molten resin (fluid phase), and the inside of the heating cylinder 3 can be observed and observed from the observation window 15 shown by the two-dot chain line in the figure.

FIG. 7 is an explanatory view showing an image obtained by the thermovision 38 through the observation window 15 shown in FIG. In the figure, the temperature of the region Z1 is T1, and the temperature of the region Z2 is T
2 and the temperature of the region Z3 is T3, T1>T2> T3
Therefore, it is understood that the temperature distribution of the stored molten resin 57 is not uniform. It is desirable that the temperature distribution of the stored molten resin 57 be uniform, and the temperature distribution calculating means 45 can calculate, for example, the average temperature Tave of the entire stored molten resin region and the temperature difference range R = Tmax-Tmin. In addition, the molding condition calculation unit 51 changes and adjusts a necessary factor among the above-described molding conditions 1 to R / Tave so as to minimize R / Tave. It should be noted that the temperature distribution is similarly observed in the other observation windows 15, and if there is an abnormally high temperature or abnormally low temperature occurrence site, the molding condition is changed to cope with this.

FIG. 8 is an explanatory diagram showing an image obtained by the video camera 30 through the observation window 15 shown in FIG. In the figure, in order to prevent the drooling phenomenon in which the molten resin 57 leaks from the nozzle 10, the screw 4 is forcibly retracted by a small amount after the completion of the measurement and the pressure of the molten resin 57 is temporarily reduced. The image when control is performed is shown. (For details of the suck back control, refer to Japanese Patent Application No. 63-248958 previously proposed by the applicant of the present invention, if necessary.) In the figure, 59 is a bubble generated by the pressure reduction of the resin pressure. The image density distribution calculating means 46 calculates the degree of occurrence of bubbles. Bubbles 5 created by the backlash
It is desirable that the number 9 is as small as possible. For example, the molding condition calculation unit 51 calculates the amount of backlash so that the forced retreat of the screw 4 is stopped at the time when even a few bubbles 59 are generated.

It should be noted that an image showing the degree of generation of the bubbles 59 is similarly obtained in the other observation windows 15, and, for example, whether or not the gas generated when the resin is melt-plasticized is successfully degassed is determined by the bubbles in a predetermined portion. If it is determined by the number of generated 59, and it is determined that the deaeration is poor, the molding condition calculation unit 51 changes the charge condition to cope with this.

Although not shown, the observation window 15 shown in FIG.
From the above, it is obvious that the image data showing the movement of the check ring 58 is obtained, and the behavior of the check ring 58 is discriminated by the check behavior calculating means 48.

FIG. 9 is an explanatory diagram showing image data obtained by the video camera 30, for example, from the observation window 15 at the center of the heating cylinder 3 when a predetermined amount of a marker is mixed in the resin material (resin pellet). . As the marker, a colored resin pellet having a higher melting temperature than the molding resin to be measured / analyzed, or a colored inorganic material chip having substantially the same specific gravity as the molding resin is used. It is designed to capture the behavior of the marker by intermittently inserting a small amount.

In FIG. 9, 60 is a marker mixed in the resin,
The arrow A indicates the resin feeding direction, and shows a state in which the markers 60 are substantially evenly distributed. However, the flow behavior of the molten resin is complicated, and it is empirically known that the resin tends to stick to the rear side of the screw thread 4c of the screw 4. That is, the area S shown by the dotted line in the figure
In some cases, resin retention may occur in this case.
The fact that a part of the marker 60 is not transferred to the front and remains therein is identified by the time-dependent analysis by the image density distribution calculating means 46, whether or not the resin is present and the location thereof. Further, by calculating the flow velocity of the marker 60 (average flow velocity or individual flow velocity) by the flow velocity calculating means 47, the average flow velocity of the resin is calculated and discriminated at a stagnation point where the flow velocity is slow. Of course, it is desirable that the amount of staying is small and small. Therefore, the molding condition calculating unit 51 changes the charge condition to cope with this.

Although not shown in the figure, the resin for measurement / analysis is mixed with a master batch made of a colored resin of the same material as the master batch by several%, and the image data taken by the video camera 30 is used to calculate the image density distribution. If the means 46 counts the density of coloring, the uniformity of plasticization can be determined. Then, for example, the molding condition calculation unit 51 changes / sets the charge condition for coping with this so that the maximum gray level difference / density average value in the predetermined region is suppressed to be within a predetermined range. Needless to say, when a colorant is mixed, it is also very useful for analysis of resin behavior during purging (resin change, color change).

Although the present invention has been described in detail with reference to the illustrated embodiments, various modifications can be made by those skilled in the art without departing from the spirit of the present invention, and the processing in the analysis calculation device 43 depends on the program to be created. Therefore, it can take various forms.

[Advantages of the Invention] As described above, according to the present invention, based on the results of direct observation and analysis of resin behavior inside the heating cylinder,
It is possible to provide a molding condition analysis method for an injection molding machine that enables more theoretical setting of molding conditions and greatly contributes to the design and evaluation of the screw, and its industrial value is enormous.

[Brief description of drawings]

Each of the drawings relates to one embodiment of the present invention. FIG. 1 is a block diagram showing a structure for analyzing molding conditions, FIG. 2 is a partially cut front view showing an injection device of an injection molding machine, and FIG. FIG. 3 is a partially cutaway front view showing a main part of the injection device, FIG.
The figure is a cross-sectional side view of the main part of the heating cylinder cut in the direction orthogonal to the axial direction, FIG. 5 is an explanatory view showing the state of the solid-fluid phase distribution obtained by a video camera, and FIG. 6 is the heating cylinder. FIG. 7 is an explanatory view showing an image obtained by a thermovision, FIG. 8 is an explanatory view showing how bubbles are generated by a video camera, and FIG. 9 is obtained by a video camera. It is explanatory drawing which shows the mode of distribution and distribution of a marker. 1 ... Base, 2 ... Abutment, 3 ... Heating cylinder, 4 ...
… Screen, 4a …… Tip head, 4b …… Neck, 4c
...... Screw, 5 …… Screw rotation drive source, 6 …… Injection drive source, 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 ...
Tightening screw, 30 ... Video camera, 31 ... Strobe light emitting part, 32 ... Strobe controller, 34 ... Video tape recorder, 35 ... Data buffer, 36 ...
A / D converter, 37 ... Monitor, 38 ... Thermovision, 39 ... Video tape recorder, 40 ... Data buffer, 41 ... A / D converter, 42 ... Monitor, 43
...... Analysis calculation device, 44 ...... Frame buffer, 45 ...
... temperature distribution calculating means, 46 ... image density distribution calculating means,
47 ... Flow rate calculation means, 48 ... Checking behavior calculation device, 49 ... Data storage part, 50 ... Table, 51 ... Molding condition calculation part, 52 ... Injection molding machine control device, 53 ... Display device, 54 ... Printer, 55 ...
... external memory, 56 ... solid phase, 57 ... fluid phase (molten resin), 58 ... check ring, 59 ... bubbles, 60 ...
…marker.

Claims (6)

[Claims] 1. A visualization heating cylinder, in which a screw is rotatably and reciprocally arranged in a heating cylinder, and an observation window for observing the inside is provided in a part of a peripheral wall of the heating cylinder. In an injection molding machine, collect at least one of image data such as resin temperature distribution data or resin behavior inside the heating cylinder through the observation window,
A method for analyzing molding conditions in an injection molding machine having a visualization heating cylinder, characterized in that the conditions at the time of a plasticizing measurement process (during a charge process) or at the time of an injection process are analyzed based on the collected data. 2. The molding condition analysis in an injection molding machine having a visualization heating cylinder according to claim 1, wherein the generation degree of bubbles in the molten resin is measured and calculated from the image data. Method. 3. The chip according to claim 1, wherein the resin material to be plasticized and melted has a marker as a marker, which is made of a colored resin having a higher melting temperature than that of the resin material, or a colored inorganic material having a specific gravity approximately equal to that of the resin material. And the flow condition of the marker is analyzed from the image data to measure and calculate the presence or absence of a resin retention location, etc. Molding condition analysis in an injection molding machine having a visualization heating cylinder Method. 4. The visualization according to claim 1, wherein a coloring agent is mixed in the resin material to be plasticized and melted, and the coloring degree of the resin material is measured and calculated from the image data. A method for analyzing molding conditions in an injection molding machine with a heating cylinder. 5. The injection molding machine having a visualization heating cylinder according to claim 1, wherein the movement of the check ring located at the tip and neck of the screw is measured and calculated from the image data. Molding condition analysis method. 6. A molding condition analyzing method in an injection molding machine having a visualization heating cylinder according to claim 1, wherein a resin temperature difference or the like of each portion within a predetermined region is measured and calculated.