JPH02255316A - Injection molder - Google Patents

Abstract

PURPOSE:To make the quick and exact setting of optimum molding conditions possible by a method wherein the molding conditions of an injection molder having a heating cylinder with no observation window is controlled on the basis of the optimum molding condition data, which is obtained from the analytical results of the temperature distribution data of the resin or of the image data of the behavior of the resin in the interior of a heating cylinder through observation windows. CONSTITUTION:By utilizing an injection molder having a visualized heating cylinder 1, the temperature distribution of the resin or the image data of the behavior of the resin in the interior of the heating cylinder 1 is obtained through observation windows by means of image pickup means such as a thermo-vision 38 or a video camera 30 so as to process them by an analytical arithmetic unit 43 consisting of microcomputer. These processed results are stored together with charges and respective setting conditions at injection process so as to find out the most suitable molding conditions depending upon every resin after various changes of molding conditions. By the function of a control device 14, which performs the control of the whole normal injection molder with no observation windows, optimum molding data stored in a PROM is calculated and extracted on the basis of the kind of resin and injection amount, which are inputted with a keying-in means for indicating, so as to automatically set injection conditions and control molding process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an in-line screw type injection molding machine, and particularly to an injection molding machine in which molding conditions can be automatically and accurately set.

[Prior Art] In order to stably and continuously obtain high-quality molded products in an in-line screw type injection molding machine, it is necessary to:
In order to obtain molded products of good quality that are free from defects such as air bubbles, discoloration due to abnormal temperature rise, molded weight variations, color unevenness, and gloss variations, conditions related to plasticization metering (charging) and injection of resin materials are important. be.

Of course, the design of the screw shape is also important as a premise.

(a) Composition ratio of the screw supply section (feed zone), compression section (compression zone), and metering section (metering zone).

(b) L/D Total length of L varnish screw D Diameter of varnish screw (C) Compression ratio (CR=h 1/h2) hl: Depth of screw groove in supply section h2: Depth of screw groove in metering section (depth of screw groove in raw material supply section) The ratio of the amount of resin accumulated in the screw groove to the amount of resin accumulated in the screw groove of the measuring section.) (d) P/D Screw design taking into consideration the thread pitch of the P varnish screw, D the diameter of the varnish screw, etc. is determined, and the quality of the plasticization measurement is determined first.

Strictly speaking, the optimal screw shape is determined for each resin to be molded, but generally a general-purpose screw design is selected that can be used commonly with as many resin materials as possible. That is, in (a) above, the length of the normal supply section is set to 5.
Stabilize the charging speed by increasing it from 0 to 60%,
Consideration is taken not to pressurize the resin as much as possible until the temperature rises and the melting point is reached, and the shear heat generation is controlled by the length of the compression section. In addition, in (b) above, L/D
Lengthening improves charge speed, resin temperature, and kneading stability, so it is compatible with the overall equipment, but L
/D is usually 20 to 22.

Further, in the above (c), when low temperature molding is required, the CR is made small to suppress shear heat generation in the kneading section, and on the other hand, to increase the crosstalk property, the CR is made large. Furthermore, the value of P/D (d) is usually selected to be 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 terms of stably transmitting the heat from the heater.

The screw design mentioned above is based on past experience.
This is done through simulation calculations on a computer, but as mentioned above, the screw is generally a general-purpose screw that can be applied to a wide variety of resin materials, and in-line injection molding machines with such screws , it is extremely important to determine under what molding conditions the device should be operated depending on the resin material.

The molding conditions are as follows: (a) Heater temperature of each zone during plasticization metering (charging).

(b) Metering stroke.

(c) How to vary the screw rotation speed with respect to the metering stroke.

(d) How to vary the back pressure with respect to the metering stroke.

(e) Amount of suckback and its speed.

There are factors such as, and during injection, (to) injection pressure.

(g) How to vary the injection speed with respect to the injection stroke.

(H) Holding pressure switching position.

(S) 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 conditions for the above-mentioned charging stroke and injection stroke were set as follows.

It was a trial-and-error method based on experience, in which the molded product was observed through test shots and molding conditions were explored and set.

That is, conventionally, the inside of the heating cylinder was I! (A) During plasticization metering (charging), the heated resin material is heated by the heater while being transferred by the screw.
The progress of melt plasticization, which is how melting occurs 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 and the presence or absence of abnormal temperature areas.

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

(E) Whether or not the resin that has become a fluid phase stagnates 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) Important check points such as uniformity of coloring of resin when coloring agent is mixed are completely within the black box, and it is necessary to sin or measure it.
It was impossible to link this to the setting of 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. Currently, we rely on experience, and setting the optimal molding conditions requires skill and extensive experience, which is time-consuming and labor-intensive. However, in recent years in the plastics industry, the types and formulations of resin materials have become more complex and sophisticated, and instead of the traditional method of setting molding conditions through trial and error, more theoretical, quick, and accurate methods are being used. There is an increasing demand for a method for setting molding conditions.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to directly control the behavior of resin inside a heating cylinder. Our objective is to provide an injection molding machine that can quickly and accurately set the theoretically optimal molding conditions based on the results of observation and analysis.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention includes a screw that is arranged in a heating cylinder so as to be able to rotate and move back and forth, and an observation window for observing the inside of the cylinder that is provided in a part of the peripheral wall of the heating cylinder. Using an injection molding machine with a visualization heating cylinder provided with the above-mentioned Il!
The temperature distribution data of the resin inside the heating cylinder or the image data of the behavior of the resin are analyzed through the observation window, and a storage means is provided for storing the optimum molding condition data obtained from the analysis results. The optimum molding condition data is used to control molding conditions of an injection molding machine having a heating cylinder without an observation window.

[Using an injection molding machine with a visualization heating cylinder,
+ Capture temperature distribution data or image data of resin behavior of the resin inside the heating cylinder through the window using imaging means such as thermovision or a video camera, and
An analysis calculation device consisting of a microcomputer performs calculation processing using a calculation program created in advance. In other words, 1. For example, the temperature distribution of each part is calculated to calculate the temperature gradient and detect the presence or absence of abnormal temperature parts, and also to calculate the image density distribution < m degrees, color distribution), the flow rate of the marker (resin flow rate), We perform calculation analysis of checking behavior, etc., and determine the degree of distribution of the solid phase and fluid phase, the degree of bubble generation in the molten resin, the flow condition of the marker in the plasticized and melted resin material, the degree of coloring of the resin material, and the degree of checking. Compute and analyze the movement of These calculation results are stored together with the above-mentioned setting conditions during the charge and injection stroke, the type of resin material used, and the charge amount, and the most suitable molding conditions are determined for each resin by variously changing the molding conditions. is found.

As mentioned above, this was obtained from the analysis results of temperature distribution data and image data. Optimal molding condition data determined by the type of resin material and charge rate are stored in the PROM in the control device of a normal injection molding machine without an observation window, which has the same screw and heating cylinder mechanism as the injection molding machine with the visualization heating cylinder described above. It is transcribed and stored in . And the above l! The control device, which controls the entire ordinary injection molding machine without a monitoring window, calculates and extracts the optimal molding data stored in the FROM, based on the resin type and injection amount (charge amount) input and instructed from the key manual means. automatically sets charging and injection conditions and controls the molding process.

[Example] Hereinafter, one example of the present invention will be described with reference to FIGS. 1 to 8.

FIG. 1 is an explanatory diagram showing a mechanical section of an injection device of an injection molding machine and a control system related thereto.

In FIG. 1, reference numeral 1 denotes a heating cylinder, and its rear end side is fixed to a headstock 2 via a mounting plate 3, and the headstock 2 is held by a support mechanism (not shown).

4 is a band heater wrapped around the outer circumference of the heating cylinder 1;
Reference numeral 5 denotes a nozzle attached to the tip of the heating cylinder 1, and a band heater 4 is also wrapped around the outer periphery of the nozzle 5.

6 is.

The screw is arranged in the heating cylinder 1 so that it can rotate and move forward and backward, and as is known, a feed zone, a compression zone, and a metering zone are formed from the rear end side to the front end side. . 7 is a hopper for supplying resin material to the rear part of the screw 6 inside the heating cylinder 1.

Reference numeral 8 denotes a rotational drive source connected to the rear end of the screw 6, and although an electromagnetic motor is used in this embodiment, it can also be replaced by a hydraulic motor. Reference numeral 9 denotes a forward and backward drive source for the screw 6, which advances the screw 6 during the injection stroke and controls the back pressure during the charging stroke.

In this embodiment, the forward and backward drive source 9 is composed of a hydraulic cylinder, and the tip of its piston rod 9a is attached to the casing of the rotational drive source (motor), so that the piston rod 9a and the , the rotary drive source 8 and the screw 6 move forward and backward in unison. In addition to the hydraulic cylinder, the forward and backward drive source 9 can also be replaced by a hydraulic motor or an electromagnetic motor by adding a suitable rotation-linear motion conversion mechanism.

Reference numeral 10 denotes a temperature sensor made of, for example, a thermocouple attached to the band heater 4, and although only one is shown in the drawing, it is actually installed in all of the band heaters 4 at each location. The measurement information from each temperature sensor 1O is sent to a control device, which will be described later, via an A/D converter (not shown), so that the control device recognizes the temperature of the band heater at each location. Reference numeral 11 denotes an injection stroke sensor, which in this embodiment includes, for example, a pulse encoder that rotates in conjunction with a nion when meshed with a rack member 12 that moves back and forth integrally with the rotary drive source 8;
Information measured by the injection stroke sensor 11 is also sent to a control device, which will be described later, and the control device recognizes the speed of the screw 6 using the stroke (position) of the screw 6 and a built-in timer. Reference numeral 13 denotes an injection pressure sensor consisting of a pressure head or the like attached to the forward/reverse drive source (hydraulic cylinder) 9;
The measurement information No. 3 is also sent to a control device, which will be described later, via an A/D converter (not shown), and the control device recognizes the injection pressure, holding pressure, and back pressure.

Reference numeral 14 denotes a control device that controls the entire injection molding machine, and includes a molding condition calculation section 15, a condition calculation table 16, a molding process control section 17, and the like. The above-mentioned condition calculation table 16 stores optimal molding conditions that have been case studied in advance for each screw design type, resin material type, and charge amount (injection amount). By specifying the resin material type and charge amount, the molding condition calculation unit 15 calculates the contents of the condition calculation table 16 and searches for or approximates the optimum value of the molding conditions as described below. There is.

That is, in the condition calculation table 16, for example, the table -
1, in an injection molding machine having a visualization heating cylinder with the same basic dimensions as the injection molding machine of this embodiment, the screw types A, B, C,
In each case, detailed case studies were conducted on resin material eaves and charge sentencing.

Data regarding molding condition items ~[stock] is stored.

The molding conditions for phases 1 to 1 above are specifically described as follows.

■Each zone (nozzle section, front, middle, and rear of the cylinder).

(underneath the hopper) heater temperature.

■How did you change the screw rotation speed relative to the metering stroke?

■How did you change the back pressure with respect to the metering stroke?

■When the screw is configured to rotate in forward and reverse directions during charging (if necessary, please refer to Japanese Patent Application No. 177128/1986, which was proposed by the applicant earlier), the time required for forward/reverse rotation of the screw. ratio.

■In the case of a configuration in which vibration is superimposed on the rotation of the screw during charging (if necessary, please refer to Japanese Patent Application No. 177129/1983 proposed by the applicant of this application), the vibration to be superimposed on the rotation is strength and its frequency.

■Amount of suckback and its speed.

■Injection pressure size and rise time.

■How was the injection speed varied with respect to the injection stroke?

■ Holding pressure switching position.

[Phase] How did you vary the pressure and time during holding pressure?

Then, the molding condition calculation unit 15 extracts the molding conditions (1) to [phase] from the data stored in the condition calculation table 16 based on the resin material type code and charge amount specified by the operator, or the molding conditions , approximately calculates the molding conditions ■ to [phase] from the approximate charge amount, and applies the calculated molding condition setting data to the molding process control unit 1.
Supply to 7.

The molding process control unit 17 uses the data given from the molding condition calculation unit 15 and other molding conditions instructed by the operator's manual key operations, such as mold opening/closing control condition values, eject control condition values, etc. The overall molding conditions are recognized and set, and the entire injection molding machine is driven and controlled based on a previously created program and measurement information from the sensors 10, 12, 13, etc. described above.

Specifically, the molding process control unit 17 controls the temperature of the band heater 4 of each part via the driver 19, controls the screw rotation by the rotational drive source 8 via the driver 20, and, Back pressure, injection speed, injection/holding pressure, etc. are controlled by the forward/backward drive source 9 via a driver 21 and a hydraulic control valve 22. (Of course, the mold opening/closing drive source and the like are also controlled by the molding process control section 17, but are not shown here for the sake of simplification of explanation.) That is,
The resin material is supplied from the hopper 7 to the rear part of the screw 6 inside the heating cylinder 1.

The screw 6 is rotated based on a command from the control device 14 (molding process control section 17), and the mixture is mixed and plasticized and transferred to the front, and the control device i! The back pressure is controlled based on the command 14, and the screw 6 is retracted by the resin pressure that is being stored on its tip side.

Then, the rotation of the screw 6 is stopped when one shot of molten resin is stored on the tip side of the screw 6 (at the end of measurement), and then, as necessary, the control device 1W14
The screw 6 is forcibly retracted by a minute amount by the forward/backward drive source 9 to perform known suckback control, and then,
At the injection start timing after a predetermined time, the control device 1
4 controls the forward and backward movement drive g9 to advance the screw 6 at a predetermined injection speed, and after injecting and filling the molten resin from the nozzle 5 into the cavity of the mold (not shown), the pressure is held for a predetermined pressure and time. It is supposed to go through a process.

In the injection molding machine of this embodiment that adopts such a configuration, the above-mentioned molding condition items - [Yes] can be set by simply inputting the screw type, resin material type, and charge amount by the operator.
is automatically set to the optimum value, so molding conditions can be set quickly and reliably.

The control device 14 having the above-mentioned functional units is actually a microcomputer, and is capable of reading and writing various I10 interfaces, a ROM that stores main control programs and fixed data, and various flags and data. RAM to control, μCPU to manage overall control
The above-mentioned functions are executed by a program created in advance, and the above-mentioned condition calculation table 16
is realized, for example, by FROM. In addition, the control device [
The results of the arithmetic processing in step 14 are sent to an output device such as a display device 23 such as a color CRT display, a printer 24, etc., as required, and are displayed or printed out in a desired form. Furthermore, the control device 14 is also connected to an external memory 25 such as a magnetic disk recording device, so that predetermined data can be exchanged as needed. Note that the data in the condition calculation table 16 may be stored in such an external memory 25.

Next, FIG. 2 shows an apparatus and method for analyzing and calculating the optimum molding conditions for the type of screw, the type of resin material, and the amount of charge, as described above and stored in the condition calculation table 16. This will be explained with reference to FIG.

FIG. 2 shows the main part of an injection device having a visualization heating cylinder with the same mechanism as the injection device shown in FIG. A plurality of heat-resistant glass bodies 27 are provided in the elongated holes 26, and a spacer 2 is provided between each glass body 17.
It is inserted through 8. Also, three long and narrow observation windows 29 are bored from the outer peripheral surface of the heating cylinder 1 to the long and narrow holes 26. Three elongated notches reaching .

As a result, the resin temperature, resin behavior, etc. inside the heating cylinder 1 can be measured or observed from each Xll observation window 29. Note that the observation window 29 is
They are provided corresponding to the feed zone, compression zone, and metering zone, respectively.

FIG. 3 shows the resin behavior, resin temperature, etc. in each zone in the heating cylinder l taken through the observation window 29 and analyzed.
FIG. 2 is a block diagram showing a configuration for determining optimal 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 29;
Reference numeral 31 designates a strobe light emitting unit which is also placed opposite the observation window 29 and whose light emission is controlled by a strobe controller 32 which receives a synchronization signal from a video camera 30. The image taken by the video camera 30 is first 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
The signal is converted into a digital signal by the /D converter 36 at an appropriate sampling rate, and sent to an analysis/arithmetic device described later. In addition, 37 is the color C connected to the VTR 34.
Images taken by the video camera 30 can be checked by the operator on a monitor consisting of an RT display, if necessary.

A thermovision 38 is installed opposite the observation window 29 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 29 as image data, and records it on the VTR 39. It looks like this. The image data recorded on the VTR 39 is taken into a data buffer 40, and then converted into a digital signal by an A/D converter 41 at an appropriate sampling rate, and sent to an analysis calculation device to be described later. In addition, 4
Reference numeral 2 denotes a monitor consisting of a color CRT display connected to a VTR 39, so that the temperature distribution image captured by the thermovision 38 can be directly viewed by the operator if necessary.

Note that the video camera 30. Both of the thermovisions 38 have a zoom function, and are provided with a turning table or the like, if necessary, although not shown.

Also, as mentioned above, since there are three wt festival windows 29, when aming three *matsuri windows 29 at the same time,
Video camera 30. A plurality of thermovisions 38 and the like are arranged accordingly, and when observing each M festival window 29 individually at different times, the video camera 30, thermovision 38, etc. need to be observed. It is moved each time to a position facing the observation window 29.

43 is an analysis calculation device for analyzing data obtained from the video camera 30 and the thermovision 38, which includes a frame buffer 44, a temperature distribution calculation means 45, an image density distribution calculation means 46. Flow velocity calculation means 47, checking behavior calculation means 48, data storage section 49. table 50,
It is equipped with a molding condition calculating section 51 and the like.

From the thermovision 38 to an analysis calculation device 43 via a VTR 39, a data buffer 40, and an A/D converter 41.
The image data sent to the frame buffer 44
After being stored once, the data is supplied to the temperature distribution calculation means 45, and the temperature distribution calculation means 45 calculates the resin temperature distribution in each zone within the heating cylinder 3 based on this data. Further, the temperature distribution calculation means 45 refers to the contents of the table 50 in which case study temperature distribution information is stored, and determines whether the temperature of each part is within the allowable range and whether the temperature gradient is within the allowable range. Executes determination processing such as whether or not it is within the range.

From the video camera 30 to the analysis calculation device via the VTR 34, data buffer 35, and A/D converter 36! 43
The image data sent to is similarly stored once in the frame buffer 44, and then supplied to the image density distribution calculation means 46, the flow velocity calculation means 47, and the checking behavior calculation means 48 at predetermined timings. 0 image density distribution calculation means 46 calculates brightness distribution and color distribution.

The degree of distribution of the solid phase-fluid phase due to the difference in brightness between the same phase (resin pellets) and the fluid phase, the degree of bubble generation due to the gas generated when the resin is melted, the degree of distribution of markers mixed in the resin, the degree of distribution of the marker mixed in the resin, The degree of mixing of the colorant mixed therein, etc. is calculated by referring to solid phase-fluid phase identification information, bubble identification information, marker identification information 1 coloring density identification information, etc. stored in advance in the table 50. . The image density distribution calculating means 46 also refers to the permissible range information stored in the table 50 as a case study in advance, and performs a process of determining whether or not the above calculation result is within the permissible 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 calculates the resin flow based on the flow velocity of the marker mixed in the resin. Calculate the speed for each part. This also allows you to check whether there are any resin retention points or not.
Calculates and determines the retention position, size of retention area, etc. Furthermore, the flow rate calculation means 47 uses the table 50.
Referring to permissible range information stored as a case study in advance, it also performs a process of determining whether or not the above calculation result is within the permissible range.

The check ring behavior calculating means 48 calculates the movement of a known check ring (check valve member) attached to the distal end neck of the screw 4 from the supplied image data of a plurality of frames, which is stored in the table 50 in advance. The calculation is performed by referring to the checking identification information obtained. Further, the check ring behavior calculation means 48 refers to the check ring behavior tolerance range information stored in the table 50 as a case study in advance to determine whether the check ring is in a predetermined operating position at a predetermined timing. hand.

It also performs processing to determine whether or not the above calculation result is within an allowable range.

The results of the calculations performed by the temperature distribution calculation means 451, the image density distribution calculation means 46, the flow rate calculation means 47, and the checking behavior calculation means 48 are taken into the data storage section 49. The data storage unit 49 also contains the details of the screw design described above regarding the screw 6 used, the type of resin material used, the amount of charge, and
Setting conditions for the charging and injection strokes described above (■
~ [phase] molding setting conditions) are also stored. Note that this information is achieved by input operations using a key-powered device (not shown) or by information supply from the control device 14 that controls the entire injection molding machine.

The data storage section 49 sequentially stores the calculation results of each of the calculation means 45 to 48 described above when test shots are repeated with varying molding setting conditions. And each calculation means 45~
The above-mentioned molding conditions (1) to [phase] when the calculation results of No. 48 indicate the most preferable state are stored in a predetermined storage area as the optimum molding conditions.

For example, depending on the shape design of the screw, the resin material is
For example, by changing the resin material to polycarbonate, acrylic, styrene, etc., the charge amount for each resin material is 1o-io.
o % in 10% increments, and the results of case studies of the above-mentioned molding conditions ■ to [phase] are as follows: Ik
It is stored in a predetermined storage area as an appropriate forming condition.

The molding condition calculation unit 51 refers to the optimal molding condition data for each resin stored in the data storage unit 49, and when molding a new unanalyzed resin, calculates molding conditions based on known molding conditions for an approximate resin material. Calculate and set, also,
With reference to the above-mentioned processing results from the image data obtained by test-shotting the unanalyzed resin, molding conditions are calculated so as to bring the molding conditions for the unanalyzed resin closer to the optimum values. The calculation results by the molding condition calculation section 5I are sent to the control device 14 of the injection molding machine described above, thereby allowing the molding conditions to be variably set.

It should be noted that it is obvious to those skilled in the art that the analysis/arithmetic unit 43 having the functional units described above is actually a microcomputer, and that each of the functions described above is realized by a program created in advance. Probably 6 again. The arithmetic processing results of the analysis arithmetic unit 43 are converted into color C as necessary.
Display device 52 consisting of an RT display. printer 53
The data is sent to an output device such as , and the analysis results are made visible to the operator. The analysis calculation device 43 is also connected to an external memory 54 such as a magnetic disk device, so that predetermined data can be exchanged as needed.

Next, several examples of methods for analyzing molding conditions will be explained with reference to FIGS. 4 to 8.

4(a), (b), and (c) are explanatory diagrams showing images obtained by the video camera 30 from the observation window 29 of the heating cylinder 1. FIG. Each time, the solid phase-fluid phase distribution state of the resin is shown, with a region 56 indicated by an open area in the diagram representing the solid phase, and a region 57 provided with dots in the diagram representing the fluid phase, respectively. In addition, the compression zone is shown entirely in the figure (a).

Appropriate parts on the downstream side in the resin feeding direction are pinked up in the order of (b) and (c). In order to achieve good melt plasticization, at the end of the compression zone,
As shown in c), it is desirable that 100% melting is completed and the melting completion position is stable, and the melting start position is also stable. Furthermore, it is desirable that the melting rate be neither too early nor too late, and that the melting rate be constant and gradually increase 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 solid phase to fluid phase in each part, and the molding condition calculation unit 51 performs The above-mentioned molding conditions (1) to (3) are set so that the melting start position and the melting completion position are stable, the melting is neither too early nor too slow between the open positions, and the melting rate is constant and gradually increases. ] Change or adjust the necessary factors.

FIG. 5 is a cross-sectional view of the tip portion of the heating cylinder l. In the figure, 6a is the tip head of the screw 6, 6b is the neck, and 6c is the screw thread.

58 is a check ring attached to the neck 6b;
Reference numeral 57 indicates the stored molten resin (fluid phase), and the heating cylinder l
The inside can be observed and observed.

FIG. 6 is an explanatory diagram showing an image obtained by the front cup thermovision 38 from the fit detection window 29 shown in FIG.

In the figure, if the temperature of region z1 is T1, the temperature of region Z2 is T2, and the temperature of region Z3 is T3, then Tl>T2>
It can be seen that the relationship is T3, and the temperature distribution of the stored molten resin 57 is not uniform. This stored molten resin 57
It is desirable that the temperature distribution is uniform, and the temperature distribution calculation means 45 calculates, for example, the average temperature Tave of the entire stored molten resin region and the temperature difference range R= T wax −
T min is calculated, and the molding condition calculation unit 51
Necessary factors among the molding conditions 1 to 0 described above are changed and adjusted so that R/T ave is minimized.

In addition, other ll! The temperature distribution is similarly observed in the observation window 29, and if there is an abnormally high temperature or abnormally low temperature region, the molding conditions are changed to deal with this.

FIG. 7 is an explanatory diagram showing an image obtained by the video camera 30 from the observation window 29 shown in FIG. The figure shows a known sack in which the pressure of the molten resin 57 is temporarily reduced by forcibly retracting the screw 6 by a minute amount after completion of metering in order to prevent the drooling phenomenon in which the molten resin 57 leaks from the nozzle 10. An image is shown when back control is performed. (For details of the suckback control, if necessary, please refer to Japanese Patent Application No. 63-248958, which was previously proposed by the applicant of the present application.

) In the figure, numeral 59 indicates air bubbles generated by reducing the resin pressure, and the image density distribution calculating means 46 calculates the degree of generation of these air bubbles. 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.

Therefore, for example, the molding condition calculating section 51 calculates the amount of suckback so as to stop the forced retraction of the screw 6 when even a small amount of air bubbles 59 is generated (when a predetermined pressure reduction state is reached). As a result, suckback control, which has been unstable in the past, can be accurately controlled.

Note that images showing the degree of generation of air bubbles 59 are similarly obtained from other observation windows 29.5 For example, it is possible to determine whether or not the gas generated when resin is melted and plasticized is successfully degassed. 59, and if it is determined that the degassing is defective, the molding condition calculating section 51 changes the charging conditions to deal with this.

Furthermore, although not shown, the observation window 29 shown in FIG.
It is obvious that image data showing the movement of the check ring 58 can be obtained from this, and the behavior of the check ring 58 can be determined by the check behavior calculating means 48.

FIG. 8 shows that when a predetermined amount of markers are mixed into the resin material (resin pellets), the video camera 30 detects, for example, 1! at the center of the heating cylinder 1! FIG. 3 is an explanatory diagram showing image data obtained from the sensor. As a marker, a colored resin pellet having a higher melting temperature than the molding resin to be measured and analyzed, or a colored inorganic chip having approximately the same specific gravity as the molding resin is used, and this is placed in the hopper 7.
However, for example, a small amount is intermittently injected to monitor the behavior of the marker.

In FIG. 8, 60 is a matrix mixed into the resin.

- Arrow A indicates the resin feeding direction, and the state in which the markers 60 are almost uniformly distributed is shown. However, the flow behavior of the molten resin is complicated, and it is known from experience that resin tends to stick to the rear side of the thread 6c of the screw 6. In other words, the resin sometimes stagnates in the region S shown by the dotted line in FIG. 1, and in this case.

The fact that a portion of the marker 60 remains without being transferred forward is determined by the temporal analysis by the image density distribution calculating means 46 to determine whether or not the resin is remaining and where it is. In addition, the flow velocity of the marker 6o (average flow velocity).

By calculating the flow velocity calculation means 47 (or individual flow velocity), the average flow velocity of the resin and the stagnation locations where the flow velocity is slow are computed and determined.

Of course, it is desirable that this retention be as small as possible, so the charging conditions are changed by the molding condition calculating section 51 to deal with this.

Although not shown, a masterbatch made of a colored resin of the same material as the resin used for measurement and analysis is mixed in a few percent, and the image data obtained by photographing this with the video camera 30 is used to obtain the image density distribution. If the calculating means 46 performs a counting process as the shade of coloring, the uniformity of plasticization can be determined. Then, for example, the molding condition calculation section 51 changes/sets the charging conditions to cope with this so that the maximum density difference/density average value within a predetermined area is suppressed to a predetermined range or less. Needless to say, if it is mixed in, it will be of great help in analyzing the behavior of the resin during purging (change of resin and one color).

Based on the results analyzed based on the image data by the analysis calculation device 43 as described above, the above-mentioned molding condition items ~ ~
The optimum setting data for [phase] is taken into the data storage section 49 or the external memory 54. And, before shipping a normal injection molding machine (without an observation window) that has the same mechanism as the injection molding machine with the visualization heating cylinder described above, the above-mentioned control device! The optimal molding conditions for each screw, resin material oblique cutting, and charge determination are written into the PROM of No. 14 using a ROM writer or the like, as described above.

[Effects of the Invention] As described above, according to the present invention, based on the results of directly observing and analyzing the behavior of the resin inside the heating cylinder,
An injection molding machine that can quickly and accurately set more theoretical molding conditions can be provided, and its industrial value is enormous.

[Brief explanation of drawings]

The drawings all relate to one embodiment of the present invention, and FIG. 1 is an explanatory diagram showing a mechanical part of an injection device of an injection molding machine and a control system related thereto, and FIG. 2 is an explanatory diagram showing an injection device having a visualization heating cylinder. Figure 3 is a block diagram showing the configuration for analyzing molding conditions using an injection molding machine with a visualization heating cylinder; Figure 4 is a partially cutaway front view of the main parts; Explanatory diagram showing the state of distribution, fifth
The figure is a cross-sectional front view of the tip of the heating cylinder, Figure 6 is an explanatory diagram showing an image obtained by thermovision, Figure 7 is an explanatory diagram showing the appearance of bubbles obtained by a video camera, and Figure 8 is an explanatory diagram showing the appearance of bubbles obtained by a video camera. FIG. 2 is an explanatory diagram showing the flow and distribution of markers obtained by a video camera. ■・・・Heating cylinder, 2・・・Head stock. 3...Mounting plate, 4...Band heater,
5... Nozzle, 6... Screw, 6
a...Tip head, 6b...Neck, 6c
...Screw thread, 7...Hopper, 8...
...Rotation drive source, 9... Forward and backward drive source, 9
a... Piston rod, 10... Temperature sensor, 11... Injection stroke sensor, 12
... Rack member, 13 ... Injection pressure sensor, 14 ... Control device, 15 ... Molding condition calculation unit, 16 ... Condition calculation table,
17... Molding process control section, 18...
- Key human power means, 19, 20. 21... Driver, 22... Hydraulic control valve, 23... Display device, 24... Printer, 25.・・・・・・
External memory, 26...Elongated hole. 27...Glass body, 28...Spacer, 29...Observation window, 30...Video camera, 31...Strobe light emitting unit, 32...
...Strobe controller, 34...Video tape recorder, 35...Data buffer, 36
...A/D converter, 37/old...monitor. 38...Thermo vision, 39...Video tape recorder, 40...Data buffer, 41...A/D converter, 42...・Monitor, 43... Analysis calculation device, 44...
・Frame buffer, temperature distribution calculation means for 45,
46... Image density distribution calculation means, 47...
. . . Flow velocity calculation means, 48 . . . Checking behavior calculation device, 49 . . . Data storage unit, 50
...Table, 51 ... Molding condition calculation section, 52 ... Display device, 53 ... Printer, 54 ... External memory, 56・・・・・・
Solid phase, 57... Fluid phase (molten resin) 58...
...Check ring, 59...Bubble, 60 Figure 4 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] Using an injection molding machine 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 an observation window for internal observation is provided on a part of the peripheral wall of the heating cylinder, the heating cylinder is inserted through the observation window. A storage means is provided which analyzes internal resin temperature distribution data or resin behavior image data and stores optimal molding condition data obtained from the analysis results, and the optimal molding conditions stored in this storage means are provided. An injection molding machine characterized by using data to control molding conditions of an injection molding machine having a heating cylinder without an observation window.