JPH0911301A - Injection machine - Google Patents

Abstract

PURPOSE: To provide an injection machine which has a good plasticization capacity and prevents a resin material from being affected by heat. CONSTITUTION: Referring to a heating cylinder 10 equipped with band heaters HT1-5 on the outer surface, a measuring zone A, a compression zone B, and a supply zone C are formed in sequence from the front injection nozzle 16 side to the rear synthetic resin supply means installation side. A cooling jacket 20 in which cooling water can be passed is formed only on the side of a synthetic resin material supply means installation on the outer surface of the supply zone formation place of the heating cylinder 10, and a temperature detection means TC3 for detecting the temperature of the supply zone C in a state in which at least one band heater HT5 is put between it and the cooling jacket 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection device, and more particularly to an injection device which has an excellent plasticizing ability and which can prevent or suppress adverse effects of heat on a resin material.

[0002]

BACKGROUND ART Conventionally, a synthetic resin material is injection molded,
In an injection molding machine for obtaining a desired molded product, an injection device is formed by inserting and arranging an injection screw rotatably and reciprocally in a heating cylinder having a plurality of band heaters arranged on the outer peripheral surface. Equipped.

In general, in such an injection device, with respect to the heating cylinder, from the rear side of the synthetic resin material supply means disposed side to the front side of the injection nozzle side, a supply zone, a compression zone, and The measuring zones are sequentially provided, and by the rotation operation of the injection screw arranged in the heating cylinder, first, in the supply zone, the resin material supplied in the heating cylinder is almost unmelted (solid). , While being gradually softened, sent out to the compression zone, then the softened resin material undergoes apparent volume compression in the compression zone, by the shearing action of the injection screw and the external heating by the band heater, While being melted (plasticized), it is sent out to the metering zone, and then the molten resin is sufficiently kneaded in the metering zone while the injection screw is retracted. The molten resin stored in the front part of the metering zone, that is, the tip part of the heating cylinder, is heated by moving the injection screw forward after the accumulation of a predetermined amount. An injection nozzle provided at the tip of the cylinder injects into the molding cavity of the mold.

Further, in such an injection device, at least one band heater having a predetermined width is provided on each outer peripheral surface of the three zones of the heating cylinder so as to surround them, and One thermocouple for detecting the temperature of the heating cylinder heated by such a band heater is attached. The band heater and the thermocouple are respectively connected to a predetermined control device, and the power supply to the band heater is turned on and off based on the temperature detected by the thermocouple. As a result, the heating cylinder is heated while the temperature of the measuring zone, the compression zone, and the supply zone are adjusted (heating control) so as to reach the preset temperature for each zone. Of.

By the way, when injection molding is performed using an injection device having such a structure, for example, when a synthetic resin material having a large specific heat (specifically, polypropylene or the like) is used as a raw material resin, Generally means that the temperature of the heating cylinder heated by the band heater is set higher, but then the temperature of the supply zone of the heating cylinder inevitably becomes higher, and during the rotational operation of the injection screw, Although there is no problem, once it is stopped, the resin material melts in the supply zone, and when the injection screw is again rotated, the raw material bites into the injection screw or is injected. It is said that the solid transport capacity in the supply zone becomes small due to insufficient rotation torque of the screw, etc., and as a result, the plasticizing capacity is significantly reduced. In addition, an extremely large problem was sometimes caused, and since the plasticizing ability was reduced, the amount of heat generated by shearing due to the rotational operation of the injection screw and the amount of heat given from the heating cylinder increased. As a result, the temperature of the resin material becomes extremely high, which may adversely affect the resin material by heat.

In the case where an injection device equipped with a long heating cylinder is used so that various synthetic resin materials can be favorably injection-molded without causing such a problem. However, in that case, not only does the entire injection device increase in size, but also the residence time of the resin material in the heating cylinder from being supplied into the heating cylinder to being injected, in other words, Since the heating time of the resin material in the heating cylinder is long, if the resin material has a property of being sensitive to heat, its physical properties are deteriorated,
Alternatively, there was a great risk that molding defects such as burning and silver streaks would occur in the obtained molded product. Therefore, increasing the length of such a heating cylinder has not been a practical measure for solving the problems such as the deterioration of the plasticizing ability as described above.

[0007] Therefore, the applicant of the present application, in order to solve these problems at once, first, utility model registration No. 3007.
In Registered Utility Model Publication No. 990, an injection device having a structure as shown in FIG. 23 was proposed. That is, in the injection device shown in FIG. 23, with respect to the heating cylinder 10 in which the injection screw 18 is inserted and arranged, from the injection nozzle 16 side in the front part to the arrangement side of the hopper 12 in the rear part, A metering zone: A, a compression zone: B, and a supply zone: C are sequentially provided. Further, two band heaters 26, 28, 30, 32, 34, 36 are provided on the outer peripheral surface of each of the three zones, two band heaters each.
The heating cylinders 10 are arranged at predetermined intervals in the axial direction, and one thermocouple 38, 40, 42 for detecting the temperature of each of the three zones is attached. Further, among the two band heaters 34, 36 provided on the outer peripheral surface of the supply zone C, a cooling jacket 20 is provided between the band heater 36 located on the hopper 12 side and the heating cylinder 10. The band heater 36 and the heating cylinder 10 are provided so as to be in close contact with each other and overlap each other. The cooling jacket 20 has a cooling pipe 22 through which cooling water is circulated.
Is wound around the outer peripheral surface of the injection pipe 18 and the cooling water is circulated through such a cooling pipe 22 so that the portion where the cooling jacket 20 is disposed in the supply zone C can be cooled. The melting of the resin material in the supply zone C at the time of stoppage is prevented, and as a result, it is possible to prevent the deterioration of the plasticizing ability and the suppression of the excessive rise of the resin temperature.

However, in such an injection apparatus, the thermocouple 42 for detecting the temperature of the supply zone C of the heating cylinder 10 penetrates the band heater 36 and the cooling jacket 20 at substantially the center thereof, and Since the tip portion is attached to the supply zone: C of the heating cylinder 10 in a state where it is inserted into the cylinder wall portion of the heating cylinder 10 by a predetermined depth,
The temperature of the cooled portion of the supply zone: C cooled by the cooling jacket 20 is detected by the thermocouple 42, and therefore, the two band heaters 34, 36 arranged in the supply zone: C are detected. Is always on,
As a result, the band heater 36 closely attached to the cooling jacket 20 inevitably reduces the cooling efficiency of the supply zone: C by the cooling jacket 20, and is provided independently on the compression zone: B side of the supply zone: C. Due to the excessive heating of the band heater 34, the temperature of the portion from the supply zone: C to the compression zone: B becomes too high, and melting of the resin material proceeds at that portion, or the temperature of the resin material increases. There was a risk that it would rise excessively.

In short, in the injection device disclosed in the above publication, the resin material in the supply zone: C of the heating cylinder 10 is different from that of the conventional device in which the cooling jacket 20 is not provided due to the arrangement of the cooling jacket 20. Can be advantageously prevented from melting, but is turned on for the band heaters 34, 36.
Since the ON / OFF control cannot be properly performed, in the melting prevention of the resin material in such a feeding zone: C,
It was difficult to obtain the expected effect, and therefore, it was sufficiently satisfactory in reducing the plasticizing ability and preventing the adverse effect of heat on the resin material. It is hard to say that there is still room for improvement in that respect.

[0010]

The present invention has been made in view of the circumstances as described above, and the problem to be solved is that the melting of the resin material in the supply zone of the heating cylinder is more sufficient. By so doing, the solid transport capacity in the supply zone is increased, and thus the plasticizing capacity is improved and the adverse effect on the resin material due to the excessive rise of the resin temperature is prevented or reduced. It is an object of the present invention to provide an improved structure of an injection device which can be effectively achieved.

[0011]

In order to solve such a problem, in the present invention, a synthetic resin material is supplied from a front injection nozzle side to a rear part of a heating cylinder into which an injection screw is rotatably inserted. A metering zone, a compression zone, and a supply zone are sequentially provided on the side where the means is arranged, and a plurality of band heaters that cover the outer peripheral surface of the heating cylinder with a predetermined width to heat are provided in at least one position in each of the three zones. Temperature detecting means for detecting the temperature of the heating cylinder heated by the plurality of band heaters, respectively, in the three zones, and the temperature of the measuring zone, the compression zone, and the supply zone. So that the temperature is preset for each zone, while detecting the temperature of each zone by the temperature detecting means, while heating the heating cylinder by the plurality of band heaters, By rotationally driving the injection screw, the synthetic resin material supplied from the synthetic resin material supply means provided at the rear portion of the heating cylinder into the supply zone of the heating cylinder is plasticized and the heating cylinder is measured. In an injection device adapted to send out to the zone side, a cooling jacket through which cooling water is circulated is arranged only on the synthetic resin material supply means disposition side on the outer peripheral surface of the supply zone forming portion of the heating cylinder. On the other hand, the temperature detection means for detecting the temperature of the supply zone is arranged at the compression zone side and at least one of the band heaters is sandwiched between the cooling jacket and the cooling zone. , Its characteristic.

According to a preferred aspect of the injection device according to the present invention, the band heater provided on the outer peripheral surface of the supply zone forming portion of the heating cylinder is provided with the compression zone of the heating cylinder. The cooling jacket is configured to have a width narrower than that of each band heater arranged in the measuring zone, and the cooling jacket is provided on the outer peripheral surface of the supply zone forming portion from the synthetic resin material supply means to the band heater side. Provided at positions separated by a dimension, between the cooling jacket and the synthetic resin material supply means, with a length in the axial direction longer than the arrangement interval of each band heater in the compression zone and the measurement zone, The exposed portion is formed such that the outer peripheral surface is exposed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to clarify the present invention more specifically, representative embodiments of the present invention will be described in detail below with reference to the drawings.

First, FIG. 1 schematically shows a main part of an example of an injection apparatus having a structure according to the present invention. Here, 10 is a heating cylinder, and a hopper 12 as a synthetic resin material supply means is disposed on the rear side (right side in the figure), and the resin material accommodated in the hopper 12 is stored in the housing 13. While being supplied from the supply port 14 into the heating cylinder 10, an injection nozzle 16 is attached to the front side (left side in the drawing) of the heating cylinder 10. An injection screw 18 is inserted inside the heating cylinder 10 and is rotatably and axially movable by a structure similar to the conventional one.

Further, in such a heating cylinder 10, from the injection nozzle 16 side of the front part to the entire length of the hopper 12 side of the rear part, it is divided into three in the axial direction, and the same measuring zone as the conventional one: A, compression Zone: B and Supply Zone: C
There are three zones. Then, as in the conventional case, the resin material supplied into the heating cylinder 10 is gradually softened by the rotation operation of the injection screw 18,
The material is sent from the supply zone: C into the compression zone: B, and after being plasticized in the compression zone: B, sent out into the metering zone: A.

Further, on the outer peripheral surfaces of the three zones A, B and C of such a heating cylinder 10, a plurality of bands (here, five bands) are heated by covering the entire outer peripheral surfaces with a predetermined width. Heaters: HT1-5 are provided respectively. That is, two in each of the weighing zone: A and the compression zone: B,
A total of four band heaters HT1 to HT4 and one band heater: HT5 in the supply zone C are arranged along the axial direction of the heating cylinder 10, respectively. : The heating cylinder 10 is heated by energizing the HTs 1 to 5.

Here, a band heater: HT provided on each outer peripheral surface of the weighing zone: A and the compression zone: B
1 to 4 are configured with a width that is smaller by a predetermined dimension than half the axial length of each zone, while the supply zone: C
Band heaters: HT5 provided on the outer peripheral surface of the band heaters HT1 to HT5 have a width that is approximately half the width of the band heaters HT1 to HT4. , Are located at substantially equal intervals on the outer peripheral surface of each zone. As a result, most of the outer peripheral surfaces of the metering zone: A and the compression zone: B of the heating cylinder 10 are covered with the band heaters: HT1 to HT4, and the compression zone on the outer peripheral surface of the supply zone: C. : Part of the B side is covered with the band heater: HT5.

And, in particular, on the outer peripheral surface of the supply zone: C of such a heating cylinder 10, the band heaters: HT1 to HT4 arranged in the measuring zone: A and the compression zone: B, respectively.
The distance between the band heater: HT5 and the hopper 12 is approximately the same as the distance between the cooling jacket 2 and the cooling jacket 2.
No. 0 is fixed by the band metal fitting 23 and arranged. The cooling jacket 20 has a width substantially the same as that of the band heater HT5, and a cooling pipe 22 having a substantially rectangular cross section through which cooling water flows is formed on the entire outer peripheral surface of the heating cylinder 10. It is configured so that it is wound around the circumference in a state of being closely attached to the circumference.

In this way, the band heater HT5 and the cooling jacket 20 are arranged adjacent to each other at approximately half of the compression zone B on the outer peripheral surface of the supply zone C of the heating cylinder 10. On the other hand, the remaining half portion between the cooling jacket 20 and the hopper 12 is not provided with any of them, and is an exposed portion 24 having an exposed outer peripheral surface.

Further, the heating cylinder 10 having such a structure.
In each of the three zones A, B and C, thermocouples TC1 to TC3 as temperature detecting means are provided one by one. Of these three thermocouples: TC1 to TC3, thermocouples provided in the metering zone: A and the compression zone: B: TC
1, 2 are respectively sandwiched between band heaters: HT1, 2 and HT3, 4 arranged in the respective zones: A, B at substantially central portions of the metering zone: A and the compression zone: B, The heating cylinder 10 is arranged so that each tip is
It is positioned by entering a certain depth into the cylinder wall.
As a result, the internal temperature of the cylinder wall at each of the measurement zone A and the compression zone B of the heating cylinder 10 is detected by the thermocouples TC1, TC2, and the band heater: HT.
Metering zone heated by 1-4: A and compression zone:
The temperature of B as a whole is grasped.

On the other hand, the thermocouple TC3 provided in the supply zone C has a
Between the cooling jacket 20 and the band heater: HT
5 are sandwiched, and the tip ends thereof are positioned in the same manner as the two thermocouples: TC1 and TC2. As a result, the internal temperature of the cylinder wall at the boundary between the heating cylinder 10 and the compression zone: B at the site where the supply zone: C is formed is detected by the thermocouple: TC3. : The temperature of the part heated by HT5 is grasped.
As is clear from FIG. 1, also in the injection nozzle 16 attached to the tip of the heating cylinder 10, a band heater: HT6, 7 and a thermocouple: TC4,5, on the tip side and the heating cylinder 10 side. Are respectively provided, whereby the injection nozzle 16 is heated and its heating temperature is detected.

Further, those band heaters: HT1 to HT7
And thermocouple: TC1 to 5 are predetermined control devices (not shown)
To each thermocouple: TC1
Band heaters: HT1 to HT7 based on the detected temperatures
The power supply to is turned on and off. Then, the metering zone of the injection nozzle 16 and the heating cylinder 10: the highest temperature in the A forming portion, the supplying zone: the lowest temperature in the C forming portion, and the compression zone: the intermediate temperature in the B forming portion. Thus, the temperature is adjusted so that the heating cylinder 10 can be heated.

Under such heating, the injection screw 18 is rotated so that the resin material supplied from the supply port 14 into the supply zone C of the heating cylinder 10 is compressed into the compression zone B. Within each band heater: H
While being plasticized by the external heating by T1 to 5 and the shearing action based on the rotation operation of the injection screw 18, it is fed into the measuring zone: A, and the front part of the measuring zone: A, that is, the tip of the heating cylinder 10. In addition, the injection screw 18 retracted by the pressure of the resin material at that time is moved forward to the tip side of the heating cylinder 10 so that the resin material However, it can be ejected through the ejection nozzle 16.

As described above, in the injection apparatus according to this embodiment, the band heater: HT5 is arranged on the outer peripheral surface of the supply zone: C of the heating cylinder 10 on the side of the compression zone: B. At the same time, since the cooling jacket 20 is provided at a position separated from the hopper 12 by a predetermined distance, even if the band heater: HT5 is energized and the supply zone: C is heated, the cooling pipe of the cooling jacket 20 is also cooled. By allowing the cooling water to circulate through 22, the area where the cooling jacket 20 is disposed in the supply zone C can be efficiently cooled, and the heat conduction to the hopper 12 side can be advantageously alleviated or blocked, The cooling jacket 20
It is possible to effectively suppress the temperature rise of the portion from the disposition portion to the disposition portion of the hopper 12.

Further, in such an injection device, a band heater: HT5 is sandwiched between the compression zone: 12 side opposite to the side where the cooling jacket 20 is provided, and a thermocouple:
From where the TC3 is installed, the feed zone:
Supply zone: C band heater: HT without being affected by the temperature of the cooling portion by C cooling jacket 20.
The temperature of the heating part according to 5 can be accurately detected, whereby the temperature of the heating part of the feeding zone: C can be adjusted appropriately, so that, unlike the conventional one, the feeding zone: C Band Heater: HT5
It is possible to advantageously prevent the portion from the formation site of B to the compression zone: B to be heated to a preset temperature by the band heater: HT5 and become unnecessarily high. Of.

Therefore, in the injection apparatus according to the present embodiment, it is possible to advantageously prevent the resin material from melting (plasticizing) in the supply zone C of the heating cylinder 10. In addition, it is possible to sufficiently secure the raw material biting into the injection screw and its rotation torque during the rotation operation of the injection screw, and thereby, the solid transport capacity in such a supply zone can be extremely improved as compared with the conventional one. As a result, the plasticizing ability can be effectively improved.

By thus improving the plasticizing ability, as compared with those having a low ability,
The amount of heat generated by shearing the resin material due to the rotation of the injection screw and the amount of heat given from the heating cylinder 10 can be advantageously reduced, whereby an excessive rise in the temperature of the resin material can be effectively suppressed, and the temperature of the resin material is heated. A value close to the set temperature of the cylinder 10 and, as a result, adverse effects of heat on the resin material can be advantageously avoided or reduced.

Moreover, in such an injection device, in the supply zone: C, the cooling jacket 20 and the hopper 12 are provided.
Since the exposed portion 24 in which the outer peripheral surface of the supply zone C (heating cylinder 10) is exposed for a predetermined length is formed between and, the exposed portion 24 is provided in the supply zone:
It can be advantageously made to function as a heat radiating portion for radiating heat from the outer peripheral surface of C, whereby an excessive temperature rise in the portion from the disposing portion of the cooling jacket 20 to the disposing portion of the hopper 12 is further increased. It can be effectively suppressed.

Further, in such an injection device, as described above, the portion from the disposition portion of the cooling jacket 20 to the disposition portion of the hopper 12 can be efficiently cooled by the cooling jacket 20. From the place, heating cylinder 10
The hot part of the can be substantially shortened. Therefore, even when injection molding with a short measuring stroke is performed using such an injection device, it is supplied into the heating cylinder 10,
The heating time of the resin material delivered to the tip portion can be effectively shortened as compared with the case of using the conventional one, and thereby, even if the raw material resin is a resin material that is easily thermally deteriorated, It can be advantageously prevented or suppressed that the physical properties are deteriorated or that molding defects such as burning and silver streak occur in the obtained molded product.

Further, in such an injection device, the cooling jacket 20 for cooling the hopper 12 side of the supply zone C of the heating cylinder 10 and the cooling pipe 22 having a substantially rectangular cross section with respect to the outer peripheral surface of the heating cylinder 10. The contact area of the cooling pipe 22 with respect to the supply zone C can be advantageously increased due to the fact that the cooling pipe 22 is wound so as to be tightly wound in the circumferential direction thereof, and thus the cooling pipe 22 is allowed to flow inside the cooling pipe 22. There is also an advantage that the cooling of the supply zone C by the cooling water to be performed can be performed more efficiently.

By the way, as described above, in the injection apparatus according to the present embodiment, the band heater: HT in the supply zone: C is set.
Excessive temperature rise from the formation site of 5 to the compression zone: B can be advantageously suppressed and the cooling jacket 2
The portion from the disposition portion of 0 to the disposition portion of the hopper 12 can be cooled more efficiently by the cooling jacket 10, a high degree of plasticizing ability can be exhibited, and the resin temperature excessively rises. However, this point is extremely clear from the results of the experiments conducted by the present inventors as follows.

That is, first, an injection device (I-1) having a structure as shown in FIG. 1 was prepared. 2 has a structure different from that of the injection apparatus shown in FIG. 1, although it has a structure according to the present invention.
An injection device (I-2) as shown in 1 was prepared. In addition,
The injection device (I-2) shown in FIG.
Supply zone: on the outer peripheral surface of C, two band heaters: HT5-a, HT5- on the compression zone: B side.
b is provided, while a cooling jacket 20 is provided on the hopper side thereof, and a band located on the compression zone: B side of the two band heaters: HT5-a and HT5-b. A thermocouple: TC3 is attached so as to penetrate the heater: HT5-a in the thickness direction thereof and to enter a predetermined depth inside the wall of the heating cylinder 10.

For comparison, as shown in FIG. 3, an injection device (I-3) having the same structure as the conventional one was prepared. In addition, in the injection device shown in FIG. 3, two band heaters 26, 28, 30, 3 are provided in each of the three zones of the heating cylinder 10, two in total.
2, 34, 36 and one each, a total of three thermocouples 3
8, 40, 42 are provided, while a cooling water passage 44 is provided in the housing 13 to which the hopper 12 is attached, and these six band heaters 26 to 36 and 3 are provided.
With the thermocouples 38 to 42, the heating cylinder 10 is heated under temperature control, and the cooling water is circulated in the cooling water passage 44.
A portion of the heating cylinder 10 where the hopper 12 is arranged is cooled.

Then, three types of injection devices (I-1, I-2, I-3) having different structures from each other are used, and the respective heating cylinders 10 are based on the temperatures detected by the thermocouples TC1 to TC3. Band heater: HT1 ~
After heating at 5, the temperature of the inner wall of each heating cylinder 10 is measured at a plurality of points, and three types of injection devices (I-1,
In each of the heating cylinders I-2 and I-3), the temperature distribution of the portion brought into contact with the resin material was examined. The result is shown in FIG. In FIG. 4, the heating cylinder 1 of the injection device (I-1) having the structure shown in FIG. 1 is used.
The temperature distribution of the inner wall of No. 0 is indicated by a one-dot chain line, the temperature distribution of the inner wall of the heating cylinder 10 of the injection apparatus (I-2) having the structure shown in FIG. The temperature distribution of the inner wall of the heating cylinder 10 of the injection device (I-3) having the structure is shown by broken lines. Moreover, the inner wall temperature of the heating cylinder 10 of each injection device (I-1, I-2, I-3) is measured by removing the injection nozzle 16 and the injection screw 18 from the heating cylinder 10 and then the heating cylinder 10 is removed. Insert a predetermined thermometer into the inner hole of the
The measurement was performed by measuring the surface temperature of the inner wall of the heating cylinder 10 at intervals of 50 mm up to a position separated by 00 mm. Furthermore, the three types of injection devices (I-1, I-2, I-3) used here are all heating cylinders 10.
At about 950 from the edge of the injection nozzle 16 side.
A hopper is provided at a position separated by mm, and a compression zone: B and a supply zone: at a position separated by about 570 mm from the edge portion.
It is the boundary with C.

As is apparent from FIG. 4, the injection device (I-1, I-1, having the structure shown in FIGS. 1 and 2 is used.
In the heating cylinder 10 of I-2), the inner wall temperature of each measurement site in the supply zone C is lower than that of the heating cylinder 10 of the injection device (I-3) having the structure shown in FIG. ing. Thereby, in the injection device according to the present embodiment,
An excessive temperature rise in the portion from the band heater: HT5 forming portion to the compression zone: B can be advantageously suppressed, and the portion from the cooling jacket 20 arranging portion to the hopper 12 arranging portion is cooled. It can be clearly seen that the jacket 10 allows for efficient cooling.

Next, a predetermined amount of PP (polypropylene) resin, ABS (acrylonitrile-butadiene-styrene) resin, and PC (polycarbonate) resin were prepared as raw material resins, and those resins and the above three types of injection were prepared. Using the device (I-1, I-2, I-3), the screw rotation speed is 100 rpm, 2 under the three conditions of measuring strokes of 50 mm, 100 mm and 150 mm.
Injection molding was performed while changing the speed to 00 rpm and 300 rpm, and the plasticizing ability and the resin temperature at that time were measured. The results are graphed and shown in FIGS.

Incidentally, in FIGS. 5 to 22, in the injection molding using the injection apparatus (I-1) having the structure shown in FIG. Each change of the capacity and the resin temperature is indicated by a one-dot chain line, and similarly, the change of the plasticizing ability and the resin temperature when using the injection device (I-2) having the structure shown in FIG. 2 is indicated by a solid line. Further, the changes in the plasticizing ability and the resin temperature when the injection apparatus (I-3) having the conventional structure as shown in FIG. 3 is used are shown by broken lines, and FIGS.
22, FIG. 8 to FIG. 10, and FIG.
13 shows the measurement results of the plasticizing ability of each injection device (I-1, I-2, I-3) when PP resin, ABS resin, and PC resin were used as raw material resins, respectively. 14 to FIG. 16, FIG. 17 to FIG. 19, and FIG. 20 to FIG. 22, each injection device (I-1, I-2, I-3) when the resin is used. The measurement results of the resin temperature for each are shown.

In particular, when injection molding is performed using these three types of injection devices (I-1, I-2, I-3) under the conditions of a measuring stroke of 150 mm and a screw rotation speed of 300 rpm. Table 1 below shows specific numerical values of the respective measurement results of the plasticizing ability and the resin temperature for each resin material. Other conditions during injection molding are: back pressure: 10 kgf / cm ² , cooling water temperature: 40 ° C., screw diameter: φ40, screw compression ratio: 2.1, metering groove depth: 2.8 mm, feed Groove depth: 6.0 mm, L / D:
The temperature of the metering zone of the heating cylinder, the compression zone, and the supply zone was set to the values shown in Table 2 below according to the type of the raw material resin.

[0039]

[0040]

As is apparent from FIGS. 5 to 22, FIG.
And an injection device having a structure as shown in FIG.
1, I-2), when using an injection device (I-3) having a structure as shown in FIG. 3, regardless of the type of raw material resin and the size of the measuring stroke. Compared with, the plasticizing ability shows a high value, and the resin temperature is low. As is clear from Table 1, for example, when the PP resin is injection-molded under the conditions of the measuring stroke: 150 mm and the screw rotation speed: 300 rpm, the injection device (I-1) and the injection device are used. By using (I-2), the injection device (I-3)
Compared with the case of using, the plasticizing ability is increased by about 27 to 34% and the resin temperature is lowered by 2.0 to 4.4 ° C., and under the same conditions, the ABS resin is used. When injection molding is performed, the plasticizing capacity is increased by about 5 to 6% and the resin temperature is 5.6 to 6.0 ° C.
When the injection molding of PC resin is performed under the same conditions, the plasticizing capacity is 13 to 14%.
The resin temperature is 0.4 to 1.2
It is about ℃ lower.

As a result, the injection apparatus according to this embodiment, and further, the injection apparatus according to the present invention, has a high degree of plasticizing ability, and the rise of the resin temperature can be advantageously suppressed, and the adverse effect of heat on the resin material can be prevented. It can be clearly recognized that extremely excellent features such as reduction or reduction can be exhibited.

The representative embodiments of the present invention have been described in detail above, but these are literal examples and the present invention should not be construed as being limited to such specific examples.

For example, in the above embodiment, two band heaters are provided on each outer peripheral surface of the metering zone: A and the compression zone: four in the heating cylinder 10, a total of four band heaters: HT1 to
4 is arranged so as to cover most of the outer peripheral surfaces, and one band heater: HT5 is provided on the outer peripheral surface of the supply zone: C.
Was provided so as to cover a part of its outer peripheral surface,
The arrangement form and the number of the band heaters are not limited to these.

Further, in the above-mentioned embodiment, as the temperature detecting means for detecting the temperatures of these three zones: A, B and C,
Although thermocouples TC3 to TC3 have been used, any of various known structures can be used as such temperature detecting means.

Further, in the above-described embodiment, the cooling jacket 20 for cooling the supply zone C of the heating cylinder 10 has a cooling pipe 2 having a substantially rectangular cross section through which cooling water is circulated.
2 was wound around the outer peripheral surface of the heating cylinder 10 in a state of being closely adhered in the circumferential direction, but the structure of such a cooling jacket is not particularly limited to this. Of course not.

In the above embodiment, the thermocouple TC3 for detecting the temperature of the supply zone C of the heating cylinder 10 and the cooling jacket 20 sandwich one band heater HT5 between them. Although it was arranged on the compression zone: B side of the zone: C, between the thermocouple and the cooling jacket,
There is no problem even if two or more band heaters are provided.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be implemented in an embodiment,
It goes without saying that all such embodiments are included in the scope of the present invention, without departing from the spirit of the present invention.

[0049]

As is apparent from the above description, in the injection apparatus according to the present invention, the inside of the heating cylinder is cooled on the outer peripheral surface of the supply zone forming portion on the side where the synthetic resin material supply means is arranged. While a cooling jacket through which water flows is arranged, the temperature of the supply zone is detected on the side of the compression zone opposite to the cooling jacket with at least one band heater sandwiched between the cooling jacket and the cooling jacket. Since the temperature detecting means is provided, when the supply zone forming portion is heated by the band heater,
By allowing the cooling water to flow through the cooling jacket, the portion from the location where the cooling jacket is provided to the location where the synthetic resin material supply means is provided can be efficiently cooled. The portion from the band heater forming portion to the compression zone in the supply zone is preset under proper temperature control based on the temperature detected by the temperature detecting means arranged at a position not affected by the temperature of the cooling portion. It can advantageously be prevented from being heated to a desired temperature and becoming too hot.

Therefore, in such an injection apparatus, the melting (plasticization) of the resin material in the supply zone can be advantageously prevented or suppressed, and the solid transport capacity in the supply zone can be extremely enhanced. The plasticizing ability can be effectively improved, and as a result, an excessive rise in the temperature of the resin material can be effectively suppressed, and the resin material can be effectively heated. The adverse effects can be advantageously avoided or reduced.

Further, in the injection apparatus according to the present invention,
Since the portion from the disposition portion of the cooling jacket to the disposition portion of the synthetic resin material supplying means can be efficiently cooled, the high temperature portion of the heating cylinder can be substantially shortened and the injection molding with a short measuring stroke can be performed. Even when performing, the heating time of the resin material supplied into the heating cylinder and delivered to the tip of the heating cylinder can be effectively shortened as compared with the conventional one, whereby the raw material resin is thermally deteriorated. Even a resin material that is easy to use has the advantage that it can be advantageously prevented or suppressed from having its physical properties deteriorated or that molding defects such as burning and silver streak will occur in the obtained molded product. is there.

When the configuration according to the preferred embodiment of the present invention described above is adopted, the exposing portion provided in the supply zone forming portion of the heating cylinder releases the heat from the outer peripheral surface of the supply zone. Can be advantageously operated as
As a result, an excessive temperature rise in the portion from the portion where the cooling jacket is arranged to the portion where the synthetic resin material supplying means is arranged can be suppressed more effectively.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional main part explanatory view showing an example of an injection device having a structure according to the present invention.

FIG. 2 is a longitudinal sectional main part explanatory view showing another example of the injection device having the structure according to the present invention.

FIG. 3 is a longitudinal sectional main part explanatory view showing an example of a conventional injection apparatus.

FIG. 4 is a graph showing the temperature distribution of the inner wall of each of the heating cylinders during heating in the injection device shown in FIGS.

FIG. 5 shows a change in plasticizing ability with an increase in screw rotation speed when PP resin is injection-molded using the injection device shown in FIGS. 1 to 3 under the condition that the measuring stroke is 50 mm. It is a graph.

FIG. 6 shows a change in plasticizing ability with an increase in screw rotation speed when PP resin is injection-molded under the condition that the measuring stroke is 100 mm by using the injection device shown in FIGS. It is a graph.

FIG. 7 shows a change in plasticizing ability with an increase in screw rotation speed when PP resin is injection-molded using the injection device shown in FIGS. 1 to 3 under the condition that the measuring stroke is 150 mm. It is a graph.

FIG. 8 shows a change in plasticizing ability with an increase in screw rotation speed when ABS resin is injection molded under the condition that the measuring stroke is 50 mm using the injection device shown in FIGS. 1 to 3. It is a graph.

FIG. 9 shows a change in plasticizing ability with an increase in screw rotation speed when an ABS resin is injection-molded using the injection device shown in FIGS. 1 to 3 under a condition that a measuring stroke is 100 mm. It is a graph.

FIG. 10 shows a change in plasticizing ability with an increase in screw rotation speed when ABS resin is injection-molded under the condition that the measuring stroke is 150 mm by using the injection device shown in FIGS. It is a graph.

FIG. 11 shows a change in plasticizing ability with an increase in screw rotation speed when PC resin is injection-molded using the injection device shown in FIGS. 1 to 3 under the condition that the measuring stroke is 50 mm. It is a graph.

FIG. 12 shows a change in plasticizing ability with an increase in screw rotation speed when PC resin is injection-molded under the condition that the measuring stroke is 100 mm by using the injection device shown in FIGS. It is a graph.

FIG. 13 shows a change in plasticizing ability with an increase in screw rotation speed when PC resin is injection-molded using the injection device shown in FIGS. 1 to 3 under the condition that the measuring stroke is 150 mm. It is a graph.

FIG. 14 is a graph showing a change in resin temperature with an increase in screw rotation speed when PP resin is injection-molded under the condition that the measuring stroke is 50 mm by using the injection device shown in FIGS. Is.

FIG. 15 is a graph showing a change in resin temperature with an increase in the screw rotation speed when PP resin is injection-molded under the condition that the measuring stroke is 100 mm by using the injection device shown in FIGS. Is.

FIG. 16 is a graph showing a change in resin temperature with an increase in screw rotation speed when PP resin is injection-molded using the injection device shown in FIGS. 1 to 3 under the condition that the measuring stroke is 150 mm. Is.

FIG. 17 is a graph showing changes in resin temperature with increase in screw rotation speed when ABS resin is injection-molded using the injection apparatus shown in FIGS. 1 to 3 under the condition that the measuring stroke is 50 mm. Is.

FIG. 18 is a graph showing changes in resin temperature with increase in screw rotation speed when ABS resin is injection-molded under the condition that the measuring stroke is 100 mm using the injection device shown in FIGS. Is.

FIG. 19 is a graph showing a change in resin temperature with an increase in screw rotation speed when ABS resin is injection-molded under the condition that the measuring stroke is 150 mm by using the injection device shown in FIGS. Is.

FIG. 20 is a graph showing a change in resin temperature with an increase in screw rotation speed when PC resin is injection-molded under the condition that the measuring stroke is 50 mm by using the injection device shown in FIGS. 1 to 3. Is.

FIG. 21 is a graph showing changes in resin temperature with increase in screw rotation speed when PC resin is injection-molded using the injection device shown in FIGS. 1 to 3 under the condition that the measuring stroke is 100 mm. Is.

FIG. 22 is a graph showing a change in resin temperature with an increase in screw rotation speed when PC resin is injection-molded using the injection device shown in FIGS. 1 to 3 under the condition that the measuring stroke is 150 mm. Is.

FIG. 23 is a longitudinal cross-sectional main part explanatory view showing an example different from that of FIG. 3 of a conventional injection apparatus.

[Explanation of symbols]

10 Heating Cylinder 12 Hopper 13 Housing 14 Supply Port 16 Injection Nozzle 18 Injection Screw 20 Cooling Jacket 22 Cooling Pipe 23 Band Metal Fitting 24 Exposure Part HT1-7 Band Heater TC1-3 Thermocouple A Metering Zone B Compression Zone C Supply Zone

Claims (2)

[Claims] 1. A heating zone in which an injection screw is rotatably inserted, a measurement zone, a compression zone, and a supply zone extending from the injection nozzle side at the front part to the synthetic resin material supply means installation side at the rear part. While sequentially provided, a plurality of band heaters that heat the outer peripheral surface of the heating cylinder by covering it with a predetermined width,
At least one is disposed in each of the three zones, and temperature measuring means for detecting the temperature of the heating cylinder heated by the plurality of band heaters is provided in each of the three zones, and the weighing is performed. Zone, compression zone,
And so that the temperature of each zone is detected by the temperature detection means while heating the heating cylinder by the plurality of band heaters so that the temperature of the supply zone becomes a preset temperature for each zone, By rotationally driving the injection screw, the synthetic resin material supplied from the synthetic resin material supply means provided at the rear portion of the heating cylinder into the supply zone of the heating cylinder is plasticized, and the measuring zone of the heating cylinder is also generated. In the injection device configured to send out to the side, the cooling jacket through which the cooling water is circulated is provided only on the side where the synthetic resin material supply means is provided on the outer peripheral surface of the supply zone forming portion of the heating cylinder. , For detecting the temperature of the supply zone, which is located on the compression zone side and has at least one of the band heaters sandwiched between it and the cooling jacket. 2. An injection device, characterized in that the temperature detecting means is provided. 2. The band heater provided on the outer peripheral surface of the supply zone forming portion of the heating cylinder has a width narrower than that of each band heater arranged in the compression zone and the metering zone of the heating cylinder. The cooling jacket is provided on the outer peripheral surface of the supply zone forming portion at a position separated from the synthetic resin material supplying means by a predetermined dimension toward the band heater, and the cooling jacket and the cooling jacket are provided. An exposed portion is formed between the synthetic resin material supply means and the exposed surface of the outer peripheral surface of the supply zone with an axial length longer than the arrangement interval of the band heaters in the compression zone and the measurement zone. The injection device according to claim 1, wherein: