JPH0647267B2 - Injection molding machine with visualization heating cylinder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an injection molding machine such as an inline screw type, and more particularly, to an injection molding machine having a visualization cylinder in which a heating cylinder including a screw can be observed. Regarding the machine.

[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 advance and retreat, and by rotating and retreating the screw, kneading, plasticizing and weighing the resin, After that, as the screw advances in a predetermined timing process, a molding process of injecting and filling the molten resin into the cavity of the mold is performed.

That is, in this type of in-line screw type injection molding machine, as is well known, the resin material supplied from the hopper to the rear portion of the screw in the heating cylinder is kneaded by the rotation of the screw while being mixed at the tip side of the screw. Be transferred to. Then, the resin material is heated by a heating cylinder heated by a band heater or the like, and the resin material is mixed between the resin materials by the kneading action of the screw, and the resin material-
It is designed to be plasticized and melted by frictional heat generation between metal surfaces.

Therefore, in order to obtain a high-quality molded product, it is necessary to achieve and control uniform and good plasticizing and melting of the resin material.For this reason, the screw design that greatly contributes to the kneading and plasticizing mechanism of the resin Optimal design is one of the important points.

By the way, the above-mentioned property of kneading and plasticizing the resin in the heating cylinder is conventionally black box, and it has been very difficult to strictly analyze the plasticizing mechanism of the resin. For this reason, conventionally, when constructing various injection molding machines, the design such as the above-mentioned screw design is usually made based on the geometrical similarity and empirical values from the case studies. It was

However, the plastics industry in recent years has a wide variety of plastics materials, and the blending of materials has become more sophisticated,
In addition, the diversification of molding conditions is progressing, and the demand for quality and precision of molded products is increasing. Under such circumstances, when designing a higher-quality, higher-cycle injection molding machine, without the theoretical proof, the experience design and trial-and-error method as in the past are used to perform the screw design. However, it has been pointed out that the optimum design is difficult, it takes a lot of time, and the resin behavior in the heating cylinder cannot be evaluated based on the new screw design.

In view of this point, the inventors of the present application have filed Japanese Patent Application No. 63-18279.
No. 2 (Patent Law No. 4 based on Japanese Patent Application No. 63-40613)
In a patent application claiming priority under Article 2-2 (1), either a vertically-divided heating cylinder is provided with a prismatic glass body at the joint or a prismatic glass body is provided for each. We proposed an injection molding machine with a visualization heating cylinder that allows the inside of the heating cylinder to be observed through the glass body, with a configuration in which a plurality of short cylinder element bodies provided with glass bodies are connected in the axial direction. .

[Problems to be Solved by the Invention] In the above-mentioned prior application, the resin behavior in the heating cylinder can be observed through the glass body from an elongated observation window along the axial direction of the heating cylinder, and the flow behavior of the molten resin It greatly contributes to the theoretical analysis such as. However, since the glass body has a prismatic shape as described above, the stress due to the molten resin pressure in the heating cylinder, the stress due to the tightening force for sealing, and the thermal stress are unbalancedly applied to the glass body and the corners of the glass body are There was a problem that parts were easily damaged. In addition, if the heating cylinder has a structure that is vertically divided into two parts, it is necessary to devise a considerable amount of work such as sticking a sealing tape to the sealing structure of the joint, while the heating cylinder is divided into a plurality of parts in the longitudinal direction. Therefore, it is necessary to add a holding mechanism that exerts a force that compresses the entire heating cylinder in the axial direction (acts a force for sealing). There was also a problem that the assembly was complicated.

The present invention has been made in view of the above points, and an object thereof is that there is no risk of damage to the glass body arranged on the peripheral wall of the heating cylinder, the sealing effect is high, and the mechanism is simple as a whole. It is to provide a molding machine having a visualization heating cylinder.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a molding machine in which a rotatable screw is arranged in a heating cylinder,
A cylindrical glass body having a cross section that matches the circular hole is provided in a circular hole formed in the peripheral wall of the heating cylinder along the axial direction, and the circular shape is formed from the outer surface of the peripheral wall of the heating cylinder. An elongated observation window along the axial direction that reaches the hole, and an elongated notch along the axial direction that reaches the circular hole from the inner surface of the peripheral wall of the heating cylinder are provided, and the inside of the heating cylinder is provided through the glass body. It is configured to be visible.

[Operation] On the peripheral wall of the heating cylinder, a long circular hole reaching from at least one end in the axial direction (longitudinal direction) to at least the vicinity of the other end is continuously bored, and a cross section matching the circular hole is formed in the circular hole. A columnar glass body is provided. In addition, the elongated observation window along the axial direction that reaches the circular hole from the outer surface of the peripheral wall of the heating cylinder and the elongated notch along the axial direction that reaches the circular hole from the inner surface of the peripheral wall of the heating cylinder are separated on the same line. Are provided in plurality. Therefore, since the heating cylinder is not divided as in the above-mentioned prior application, it is not necessary to seal the divided surface and the sealing effect is good. Further, even if the glass body is pressed against the inner surface on the outer side of the circular hole by the resin pressure inside the heating cylinder, the circular holes and the glass body are pressed against each other at the arc surfaces, so the pressing force is Since the glass body is dispersed and no local stress is applied to the glass body, breakage of the glass body is prevented as much as possible. Further, since the glass body is a cylinder, it is expected that the visibility will be improved by the lens effect.

[Embodiment] The present invention will be described below with reference to an embodiment shown in FIGS. 1 to 5. FIG. 1 is a partially cut front view showing an essential part of an injection device of an injection molding machine, FIG. 2 is a front view of an injection device of an injection molding machine, and FIG. 3 is a heating cylinder cut in a direction orthogonal to an axial direction. 4 is an explanatory view showing a pressing force by a resin pressure acting on the glass body, and FIG. 5 is a block diagram of the image processing apparatus.

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).

Next, the structure near the heating cylinder 3 will be described with reference to FIGS. 1 and 3.

As shown in FIG. 1, 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. 3, 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. 1 and 3, on the outer surface side of the peripheral wall of the heating cylinder 3, there is provided an elongated observation window 15 extending in the axial direction from the outer surface of the peripheral wall to the circular hole 13, for example by 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 circular hole 13 so as to have 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, and the glass bodies 17 on the front end side are inserted. 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 structure, the resin behavior of the above-mentioned feed zone, compression zone and metering zone in the heating cylinder 3 can be observed from each observation window 15 through the glass body 17. In addition, since the glass body 17 has a columnar shape, the glass body 17 functions as a convex lens, the resin behavior is enlarged, and it is possible to observe and improve the visibility. Further, since the glass body 17 has a columnar shape, the glass body 17 can be moved by the resin pressure inside the heating cylinder 3 as shown in FIG. 4 (the clearance is exaggerated for convenience of description). Even if the pressing force is applied to the inner surface of the circular hole 13 on the outer side, the circular hole 13 and the glass body 1
Since the circular arc surfaces are pressed against each other, the pressing force is dispersed and the glass body 17 is not locally stressed.
Damage to 7 is prevented 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, in the embodiment,
The heating cylinder 3 is not divided as in the above-mentioned prior application, and the sealing effect by the tightening screw 20 prevents the resin from leaking.

In this embodiment, the tightening screw 20 exerts a force in the direction of narrowing the slit 14 so that the inner surface of the circular hole 13 wraps and fastens the outer peripheral surface of the glass body 17. As described above, the glass body 17 receives the pressing force to the outer side inner surface of the circular hole 13 due to the resin pressure, so that the fitting error between the circular hole 13 and the glass body 17 and the like should be well managed. Therefore, it is possible to obtain a sufficient sealing effect even without the presence of the slit 14 and the tightening screw 20.

FIG. 5 is a block diagram of an image processing apparatus for photographing and recording or analyzing the behavior of the resin in each zone in the heating cylinder 3 through the observation window 15. In the figure, 30 is a camera image pickup unit installed facing the observation window 15, 31 is a video camera main body, 32 is a strobe controller, 33 is a stroboscopic light emission unit directed to the observation window 15, and a photographing unit from these. Is configured. Reference numeral 34 is a video deck, 35 is a monitor, and a recording section is constituted by these, and a synchronization signal is output from the video camera main body 31 to the strobe controller 32 and the video deck 34. Reference numeral 36 is a calculation control unit composed of a microcomputer, 37 is a printer, and an image processing unit is composed of these.

Here, the resin material (resin pellet) charged from the hopper 8 is heated by external heat from the heating cylinder 3 and frictional heat generated between the resin material and between the resin material and the metal surface by the kneading action of the screw 4 as described above. To raise the temperature,
Kneaded and plasticized. Although the exact mechanism of this plasticization process is not completely understood at present, it is generally considered to take the following processes. That is, the melting of the resin material is started from the portion in contact with the inner surface of the heating cylinder 3, and the melted resin is mixed with the inner surface of the heating cylinder 3.
A thin molten layer is formed between the unmelted pellet layer (solid bed) formed inside the layer. When this thickness develops above the flight clearance, it is scraped off by the flight of the screw 4 and collected after the screw groove to form a melt pool. This melt is circulated in the pool and is kneaded with the previous melt, so that the above-mentioned solid bed is gradually reduced, and eventually the entire screw groove is filled with the melt.

In this embodiment, the resin behavior in the heating cylinder 3 as described above is photographed by the camera imaging unit 30 and the video camera main body 31, and the video signal thereof is recorded by the video deck 34.
Then, desired image processing is performed by the arithmetic control unit 36, and data from a resin pressure sensor (not shown) is added to this so that the resin behavior can be obtained as a large number of still images. Configured.

Although the present invention has been described above with reference to the illustrated embodiments, it goes without saying that various modifications can be made by those skilled in the art without departing from the spirit of the present invention. It can be installed in any position.

[Advantages of the Invention] As described above, according to the present invention, in a structure in which the inside of the heating cylinder can be observed, there is no risk of damage to the glass body disposed in the peripheral wall of the heating cylinder, and the sealing effect is also provided. high,
In addition, the glass body has a lens effect to improve visibility,
Furthermore, it is possible to provide an injection molding machine having a simple mechanism as a whole, and to provide a device that greatly contributes to analysis of resin behavior and the like, and its industrial value is great in the field of this kind of injection molding machine.

[Brief description of drawings]

Each of the drawings relates to one embodiment of the present invention. FIG. 1 is a partially cutaway front view showing a main part of an injection device of an injection molding machine, FIG. 2 is a front view of an injection device of the injection molding machine, and FIG. The figure shows a cross-sectional side view of essential parts of the heating cylinder cut in a direction orthogonal to the axial direction
FIG. 5 is an explanatory view showing the pressing force by the resin pressure acting on the glass body, and FIG. 5 is a block diagram of the image processing apparatus. 1 ... Base, 2 ... Abutment, 3 ... Heating cylinder, 4 ...
… Screw, 5 …… Screw rotation drive source, 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 ...
... Tightening screw (bolt), 30 ... Camera imaging part, 31
...... Video camera body, 32 ...... Strobe controller, 33 ...... Strobe light emitting unit, 34 …… Video deck,
35 ... Monitor, 36 ... Arithmetic control unit, 37 ... Printer.

Claims (4)

[Claims] 1. In an injection molding machine in which a rotatable screw is disposed in a heating cylinder, a circular hole formed along the axial direction in a peripheral wall of the heating cylinder has a cross section that matches the circular hole. With a cylindrical glass body having an elongated observation window along the axial direction that reaches the circular hole from the outer surface of the peripheral wall of the heating cylinder, and an axis that reaches the circular hole from the inner surface of the peripheral wall of the heating cylinder. An injection molding machine having a visualization heating cylinder, wherein an elongated notch along the direction is provided so that the inside of the heating cylinder can be visually recognized through the glass body. 2. The circular hole formed in the peripheral wall of the heating cylinder is continuously provided from one end of the heating cylinder to at least the vicinity of the other end thereof, and the observation window-aligned notches are provided. An injection molding machine having a visualization heating cylinder, wherein a plurality of heating cylinders are arranged separately in the axial direction. 3. The visualization heating cylinder according to claim 2, wherein a plurality of the glass bodies are arranged at a portion corresponding to the observation window, and a spacer is arranged between the glass bodies. Injection molding machine. 4. The heating cylinder according to claim 1, wherein a slit along the axial direction communicating with the circular hole is formed on a peripheral wall of the heating cylinder, and a screw is screwed and fastened in a screw hole orthogonal to the slit. Thus, an injection molding machine having a visualization heating cylinder is characterized in that a stress that narrows the slit is applied.