JP3609872B2 - Cylinder temperature control device for injection device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a cylinder temperature adjusting device for an injection device.
[0002]
[Prior art and problems to be solved by the invention]
In the case of injection molding of thermoplastic resin, in the injection device of the injection molding machine, the resin material supplied from the hopper is fed into an injection cylinder preheated by a heater or the like, and the resin material is heated and melted. A screw or the like formed in the injection cylinder is rotated to feed the resin material forward while thoroughly kneading the resin material. Next, a molten resin material for one shot is injected into a mold from a nozzle installed in front of the injection cylinder, and after solidified by cooling, it is taken out as a product.
[0003]
In this plasticization process, it may become superheated due to the influence of frictional heat (or shear heat) generated by kneading the material with the screw, and it is necessary to maintain the cylinder temperature at the optimum molding temperature by cooling.
[0004]
If the molding optimum temperature cannot be maintained, the thermal stability of the cylinder temperature is deteriorated. This non-equilibrium temperature change during the molding of thermoplastic resin makes the flow behavior in the mold during actual injection molding very complicated, and the resin material is decomposed, discolored, deteriorated in physical properties, etc. As a result, the stability of the product deteriorates and immediately leads to a deterioration of the quality of the molded product.
[0005]
In addition, when mass-producing molded products by performing multiple shots continuously, the optimal molding temperature cannot be maintained at a constant temperature between shots. Cannot be obtained, resulting in non-uniformity between shots.
[0006]
Furthermore, when performing blow molding with a hot parison (one stage) type injection blow molding machine that blow-molds bottles from a preform that retains heat during injection molding, the cylinder temperature in the injection device is stable. The property is an important factor that determines the optimum temperature for blow molding in the subsequent process. The appropriate temperature for blow molding is determined within a certain appropriate temperature range depending on the type of resin material. If this temperature cannot be maintained, it will have a serious adverse effect on the blow characteristics, and the desired bottle quality such as wall thickness distribution cannot be secured.
[0007]
Especially in a blow molding machine that does not have a temperature control station that controls the temperature of the preform after injection molding and before blow molding, the correlation between the injection temperature and the blow molding temperature is further increased, and proper temperature adjustment of the injection cylinder is further improved. It was desired. Blowing with temperature control stationformEven in a machine, it has been desired to adjust the temperature of the injection cylinder appropriately because variations in injection molding temperature cannot always be corrected.
[0008]
Therefore, conventionally, as shown in FIGS. 9A and 9B, a centrifugal fan 602 is disposed in the region of the injection cylinder 600 on the nozzle 608 side, and air cooling by the centrifugal fan 602 is performed.
[0009]
Specifically, as shown in FIGS. 9A and 9B, a band heater 606 is disposed in the injection cylinder 600, and the nozzle of the injection cylinder 600 is mainly in a state of non-contact with the injection cylinder 600 and the band heater 606. The cylinder cover 610 is provided only in the region on the 608 side. A cold air insertion cylinder 612 extended on the lower surface of the cylinder cover 610 and a centrifugal fan 602 attached and fixed on the machine base 614 are connected by a metal bellows heat resistant hose 616, and the centrifugal fan 602 is connected. Air was blown and cooling was performed. A heat insulating material 618 is further provided around the band heater 606 where the cylinder cover 610 is not provided.
[0010]
However, the heat-resistant hose 616 needs to have a sufficient length so as not to hinder the injection cylinder 600 that moves forward and backward on the machine base 614, and the entire length of the heat-resistant hose 616 must be increased. Therefore, the cooling efficiency is deteriorated, and a relatively large centrifugal fan has to be used. For this reason, there has been a problem that the cost of the apparatus increases and the running cost increases due to the power consumption of the centrifugal fan.
[0011]
Further, in the conventional cooling by the centrifugal fan, workability is not good for appropriately adjusting the air volume.
[0012]
Furthermore, due to the presence of the heat-resistant hose and the large centrifugal fan, there is a problem that the space efficiency in the lower region of the injection device is poor, the maintenance work is difficult, and the appearance is unsatisfactory.
[0013]
Further, in the conventional cylinder temperature adjustment, since the centrifugal fan is always operated in a state where the heater is operated, there is a problem that the power consumption by the centrifugal fan is increased and the running cost is further increased.
[0014]
An object of the present invention is to improve the cooling efficiency by adjusting the temperature by not using a heat-resistant hose, make the structure around the injection cylinder orderly, facilitate the maintenance work, and reduce the manufacturing cost and running cost. An object of the present invention is to provide a cylinder temperature adjusting device.
[0015]
Another object of the present invention is to provide a cylinder temperature adjusting device for an injection device that can easily adjust a cylinder temperature more easily by responding to fluctuations in the outside air temperature.
[0016]
Still another object of the present invention is to provide an injection device capable of performing temperature adjustment in a compression zone and a metering zone, in which temperature adjustment is particularly important in an injection cylinder, with higher accuracy and more accurately controlling the temperature distribution in the axial direction of the injection cylinder. An object of the present invention is to provide a cylinder temperature adjusting device.
[0017]
[Means for Solving the Problems]
The invention described in claim 1Injection in which a supply zone for supplying a molding resin material forward, a compression zone for melting and compressing the resin material with heat and pressure, and a measurement zone for measuring one shot of the resin material are provided in order along the axial direction. This is a temperature adjusting device having a cylinder and capable of adjusting the temperature with each zone 5. A temperature sensor for measuring the cylinder temperature is provided for each zone, and a heater divided into zones for each zone is provided around the injection cylinder. Based on the temperature measured by the temperature sensor, the controller adjusts the cylinder temperature by performing on / off control and / or energization control of the heater for each zone. A cylinder cover is arranged so as to cover the periphery of the injection cylinder and the heater. A deaeration hole formed in the cylinder cover corresponding to each zone and a cool air introduction hole formed in the cylinder cover corresponding to at least the compression zone and the metering zone are provided. A cooling fan for introducing cool air into the cylinder cover through the cool air introduction hole is provided. When the upper limit temperature and the lower limit temperature are set in advance for at least the compression zone and the metering zone and the temperature measured by the temperature sensor provided in the zone exceeds the upper limit temperature, the control unit is arranged in the corresponding zone. The cooling fan is controlled to start and when the temperature falls below the lower limit temperature, the cooling fan arranged in the corresponding zone is controlled to stop.
[0019]
Claim2In the device described in claim1In addition to the control device similar to the inventive device, the heater control is energized by, for example, PID control. Then, the control unit sets a lower limit temperature for at least the compression zone and the metering zone, and when the temperature measured by the temperature sensor provided in the zone exceeds the lower limit temperature, the control unit is arranged in the corresponding zone. The cooled cooling fan is activated.
[0020]
Claim1Or2In the device described in claim3As shown in the figure, it is preferable to form a partition wall at the boundary of each zone in the cylinder cover.
[0021]
Claim1Thru3In an apparatus according to any of the claims4As shown, it is preferable to further provide a heat-insulating attachment member that is interposed between the cylinder cover and the cooling fan and is attached to the cylinder cover.
[0022]
Claim4In the device described in claim5As shown, it is preferable to further provide an openable and closable adjustment member that adjusts the aperture ratio of the cold air introduction hole.
[0029]
[Action]
Claims 1 to5According to each invention described in (1), the following operations (1) to (6) are provided.
[0030]
(1) By providing a cooling fan directly on the cylinder cover, cooling air is supplied to the heater by a metal heat-resistant hose from a conventional centrifugal fan placed on the machine base. Can be blown directly to the heater. For this reason, the cooling efficiency is improved, the temperature adjustment can be realized reliably, and the quality of the final molded product can be improved.
[0031]
In addition, since the thermal stability of the cylinder temperature has improved, there is no variation in the molding temperature between shots even when multiple shots are taken to continuously produce molded products. Regardless of the number of times, a plurality of uniform molded products can be produced in large quantities while maintaining a high quality state.
[0032]
This is because, for example, in a hot parison (one stage) type blow molding machine that blow-molds a bottle from a preform that retains heat during injection molding, the temperature of the cylinder of the injection cylinder is adjusted so that each molding cycle The thermal stability of the preform temperature can also be improved, and variations in the quality of the final molded product at each number of times when a preform injection-molded multiple times can be reduced.Furthermore, the flat type axial flow fan can be made inconspicuous from the surroundings, resulting in a very clean appearance.
[0033]
(2) Especially claims4Then, since the cooling fan is disposed on the cylinder cover via the heat insulating mounting member, solid heat conduction to the cooling fan can be prevented even if the heater reaches a high temperature (for example, 270 ° C. when using PET).
[0034]
(3) Especially claims5Then, by providing the adjustment member, the opening ratio of the cold air introduction hole can be adjusted, the flow rate of the cooling air introduced into the cylinder cover can be freely adjusted in response to fluctuations in the outside air temperature, etc. It can be adjusted accurately.
[0036]
(4) Especially claims1Then, by keeping the set temperature range constant by starting and stopping the cooling fan, it is possible to reduce the power consumption and reduce the running cost while ensuring the thermal stability of the cylinder temperature.
[0037]
(5) Claim2In this control, the heater control is energized by, for example, PID control. At this time, if the cooling fan is started when the temperature of the cylinder exceeds the lower limit temperature lower than the set temperature, the temperature rise due to the shear heat is regulated in advance, and the cylinder temperature is more reliably set to a desired value. Asymptotically approaching the set value, the set temperature can be kept more constant.
[0038]
(6) Especially claims1Or2Then, the control by the cooling fan as described above is performed at least in the compression zone and the metering zone, so that the temperature distribution in the axial direction of the injection cylinder can be controlled more precisely. In particular, the claims3If the partition wall is provided, the cooling air can be independently ventilated for each zone, the cooling efficiency can be improved, the set temperature for each zone can be accurately reproduced, and the thermal stability of the resin material described above can be improved. Further improvement can be promoted, and the quality of the molded product is improved.
[0044]
【Example】
Hereinafter, an embodiment in which the present invention is applied to an injection stretch blow molding machine will be specifically described with reference to the drawings.
[0045]
[1] Overview of injection stretch blow molding machine 1
An injection stretch blow molding machine 1 in which the injection device 10 is used will be described with reference to FIGS. 1 and 8. FIG. 1 shows an injection stretch blow molding machine 1 which is an embodiment of the present invention. FIG. 8 is an enlarged plan view of a portion of four stations of the injection stretch blow molding machine 1.
[0046]
The injection stretch blow molding machine 1 is for molding a plastic container made of, for example, polyethylene terephthalate (PET). As shown in FIG. 1, a machine base 80 and an injection arranged on the machine base 80 are used. 4 stations, which will be described later, are arranged on one stage on the machine base 80 at a position facing the injection apparatus 10.
[0047]
Specifically, as shown in FIG. 8, an upper base 86 supported by a pair of tie rods 85 is arranged on the machine base 80 in the area where the four stations are arranged. A rotating plate 87 is provided on the side so as to be intermittently rotatable every predetermined angle (for example, 90 degrees).
[0048]
On the lower surface of the rotating plate 87, a neck type support plate 92 configured by a split plate that supports a neck mold 90 capable of holding a plurality of preforms or neck portions of a molded product that can be opened and closed. However, the plurality of neck dies 90 can be stopped at four positions at intervals of 90 degrees from the center.
[0049]
Then, along the rotational conveyance path of the neck mold 90, the injection molding station 100 that performs injection molding of the preform by nozzle-touching the injection device 10 and the preform that holds the heat at the time of injection molding are adjusted to an appropriate temperature for stretching. Temperature control station 200 to perform the biaxial stretching of the container from the preform-CompletionA stretch blow molding station 300 for shaping and a take-out station 400 for releasing the container from the mold are disposed.
[0050]
The neck mold 90 is used as an injection cavity mold for defining the outer wall of the neck portion of the preform in the injection molding station 100, and thereafter also used as a transport jig for the preform or molded product.
[0051]
The layout of each station of the stage molding machine to which the present invention is applied is not limited to that shown in FIG. 8, and may be another conveying system that does not use a rotating plate.
[0052]
[2] About injection device and temperature control device 20
The structure of the injection device 10 and the temperature adjustment device 20 will be described with reference to FIGS. As shown in FIG. 1, the entire injection apparatus 10 is disposed on a machine base 80 and can be advanced and retracted in the direction of arrow A in FIG. 1 by a motor 82 such as a pump motor. On the machine base 80, an operation panel 84 is installed in the vicinity of the injection device 10, and various control parameters for the four stations including the injection molding parameters of the injection device 10 are concentrated on the operation panel 84. Operation input.
[0053]
The injection device 10 is roughly divided into a hopper 14 that supplies a resin material (for example, a PET resin material), an injection cylinder 16 that performs resin filling drive by, for example, an in-line screw method, and a distal end side of the injection cylinder 16. And a nozzle 18 that nozzle-touches the mold of the injection molding station 100.
[0054]
The temperature adjustment device 20 is shown in FIG., FIG.7, the injection cylinder 16, the heater 22, the heat insulating material 24, the cylinder cover 30, the deaeration hole 34, the cold air introduction hole 42, the cooling fan 52, the heat insulating attachment member 54, the adjustment member 58, the temperature sensor 60, and An input / output unit 62 is included.
[0055]
The injection cylinder 16 is formed in a cylindrical shape, and, for example, in the case of an inline screw type, a screw (not shown) is arranged therein, and this screw is driven to rotate by a motor 12 (for example, an oil motor). The
[0056]
In addition, this injection device 10 can use various resin filling drive systems, such as a plunger type, a screw, or a plunger pre-puller type, instead of an in-line screw.
[0057]
Further, as shown in FIG. 2B, the injection cylinder 16 has a function of melting a resin material with heat and pressure and injecting the resin material by a predetermined amount from the nozzle 18. Is divided into an axial direction into a supply zone I that is fed forward, a compression zone II that melts and compresses the resin material with heat and pressure, and a metering zone III that measures one shot of resin material. ing.
[0058]
The heater 22 is disposed around the injection cylinder 16 and has a function of heating the injection cylinder 16 to melt the resin material, and is constituted by a band heater, for example. In addition to the band heater, the injection cylinder 16 may have a double wall (jacket) structure for circulating hot water, or other types of electric resistance type.
[0059]
Further, the temperature of the heater 22 is adjusted for each of the three zones, and the temperature of the heater 22 is lowered as much as possible at the base end (the hopper 14 side) of the injection cylinder 16 and toward the free end (the nozzle 18 side). It is preferable to set the temperature to be higher. This is because the temperature in the injection cylinder 16 is taken to make it easier for the gas in the injection cylinder 16 to escape later, and the resin material bites into the screw to improve the quality of the molded product to be injected. Because it can be urged.
[0060]
As shown in FIG. 2A, the heat insulating material 24 is disposed further around the heater 22 fixed to the injection cylinder 16 in a region where a cooling fan 52 described later is not disposed, that is, in the supply zone I. In this way, the heat retention effect is enhanced by suppressing the heat radiation of the heater 22 in the zone I where there is little need for cooling.
[0061]
As shown in FIGS. 2A, 2B, and 3A, the cylinder cover 30 is disposed so as to cover the periphery of the injection cylinder 16 and the heater 22 with a gap 26 therebetween. The lid portion 32 and the bottom portion 40 are connected by connecting metal fittings 48a and 48b.
[0062]
As shown in FIG. 3 (A), for example, the bottom 40 can be rotated with respect to the fixed lid portion 32 via a connecting fitting 48a as shown by a two-dot chain line in FIG. Can be fixedWhendoing. Thereby, maintenance of the cylinder 14, the heater 14, the heat insulating material 24, etc. becomes easy.
[0063]
In addition, the structure of the cover part 32 and the bottom part 40 of the cylinder cover 30 is not limited to the connection position formed at a position below the center axis of the cylinder 16 as shown in FIG. Instead, it may be divided at a position near the center axis of the cylinder 16 as shown in FIG. Further, the connection method is not limited to the method of rotating the bottom portion 40, and any one of the bottom portion 40 and the lid portion 32 may be detachable in the vertical direction.
[0064]
Further, a deaeration hole 34 is formed on the top surface of the lid part 32 of the cylinder cover 30, and a cold air introduction hole 42 is formed on the bottom part 40 of the cylinder cover 30 at a position substantially opposite to the injection cylinder 16. .
[0065]
The deaeration hole 34 improves the air permeability of the cylinder cover 30 and promotes cooling of the injection cylinder 16, and corresponds to each of the zones II and III.TLinda cover 30MultipleIt has been drilled.
[0066]
In addition, when the deaeration hole 34 is located substantially opposite to the cold air introduction hole 42 with the cylinder 16 in between, the cooling air introduced from the cold air introduction hole 42 is flown symmetrically about the axis of the injection cylinder 16. And the cooling rate in the circumferential direction of the cylinder 16ofNonuniformity can be reduced.
[0067]
As shown in FIG. 2B, a plurality of holes 44 are formed in the bottom portion 40 in a region where a cooling fan 52 described later is not disposed, and a metal mesh 46 is disposed in the hole 44. Yes. In addition to the air permeability being further improved by the metal mesh 46, if the metal mesh 46 is also removable, the workability during maintenance is also improved.
[0068]
Furthermore, as shown in FIGS. 2 (B) and 3 (A), the cylinder cover 30 is a boundary between the zones I, II, and III and does not interfere with the injection cylinder 16. For example, a partition wall 50 is formed around the upper semicircular portion of the cylinder 16. This partition wall 50 is for suppressing the cooling air by the cooling fan 52 from diffusing across zones, improving the cooling efficiency for each zone, and performing clear temperature control. Various wirings such as a heater can be inserted into the space 50a of the lower semicircular portion without the partition wall 50.
[0069]
In addition, the partition wall 50 can also be set as the following structures. When the lid portion 32 and the bottom portion 40 are divided into two with a horizontal line passing through the cylinder center as a boundary, as shown in FIG. 4B, the partition wall 50 formed in the upper lid portion 32 and the lower bottom portion The partition wall 51a is formed of two types of partition walls. Thus, for example, when the bottom portion 40 is rotated, the partition wall 50 and the cylinder 16 do not interfere with each other, and the removal can be performed smoothly. The same configuration can be made when the bottom portion 40 or the lid portion 32 is configured to be detachable in the vertical direction.
[0070]
In this case, a gap 51b is provided in the lower partition wall 51a. Thereby, various wirings such as a heater can be inserted into the gap 51b.
[0071]
In the present embodiment, the cylinder cover 30 is formed so as to cover the entire area of the injection cylinder 16 in the axial direction. For this reason, compared with the case shown in FIG. 9, it becomes a refined design with a clean appearance.
[0072]
The cold air introduction hole 42 has a function of introducing air into the gap 26 from the outside of the cylinder cover 30, and corresponds to the zones II and III as shown in FIG. 2A or as shown in FIG. Corresponding to each zone I, II, and III, it is formed on the bottom surface of the bottom portion 40 of the cylinder cover 30 that faces the position directly below the injection cylinder 16. A cooling fan 52 is disposed facing the cold air introduction hole 42. In this way, the cooling air of the cooling fan 52 can be brought into direct contact with the heater 22, so that the cooling efficiency is further improved. Further, since the cold air introduction hole 42 is substantially opposed to the deaeration hole 34, the cooling air can be discharged from the deaeration hole 34 using the upward flow, and the cooling effect can be increased.
[0073]
As shown in FIG. 5A, the cooling fan 52 is preferably a flat axial fan type in which blades are rotated by a motor. Depending on the cooling performance, an axial fan 72 having a different number of blades can be used as shown in FIG.
[0074]
In this way, by disposing the cooling fan 52 directly under the cylinder cover 30, the cooling air is supplied from the centrifugal fan 602 disposed on the conventional machine base 80 by the metal heat-resistant hose 616 to the band heater 606. Compared with the case of supplying to (FIG. 9), the cooling efficiency is improved, and the temperature adjustment especially during overheating can be reliably controlled.
[0075]
Further, as shown in FIG. 1, since the conventional heat resistant hose 616 shown in FIG. 9 is not provided in the region between the injection device 10 and the machine base 80, the inspection device 10 is inspected and maintained. Improved workability.
[0076]
The reason why the use of this axial fan type cooling fan 52 is superior to that of the conventional centrifugal fan 602 will be described below.
[0077]
The conventional centrifugal fan 602 is vertically long in function and has a considerable weight, and the cylinder cover 610 has to be extremely strong and unnecessarily large in order to be directly attached to the cylinder cover 610. The large centrifugal fan 602 protrudes from the cylinder cover 610 and looks bad.
[0078]
On the other hand, in the axial fan type cooling fan 52, as shown in FIGS. 5 (A) and 5 (B), the thickness d can be reduced, and the appearance becomes very clean. Does not interfere with work.
[0079]
As shown in FIGS. 2 (A), 3 (A), and 3 (B), the heat insulating attachment members 54a and 54b are provided with the cylinder cover 30 and the cooling fan 52 to attach the cooling fan 52 to the cylinder cover 30. And is formed in a frame shape along the periphery of the cold air introduction hole 42.
[0080]
Therefore, even when the heater 22 reaches a high temperature (for example, 270 ° C. when PET is used), solid heat conduction to the cooling fan 52 can be prevented, and the cooling fan 52 can be operated within the temperature guaranteed range. .
[0081]
As shown in FIG. 3, the adjustment member 58 opens and closes the cool air introduction hole 42 to adjust the opening ratio, and freely adjusts the flow rate of the cooling air of the cooling fan 52 to control the temperature adjustment more accurately. Have
[0082]
The adjusting member 58 is formed as a shielding plate that is slidably supported in a slit 56 formed between the frame-like heat insulating mounting members 54a and 54b shown in FIGS. 3A and 3B, for example. As shown in FIGS. 3A and 3B, the opening and closing is performed in the same direction as the operation panel 84 of the injection stretch blow molding machine 1 in FIG. 1 (arrow B in FIG. 3A), and the opening and closing is performed. It has the operation part 59 which operates.
[0083]
By forming the operation unit 59 in the same direction as the operation panel 84, the burden on the operator when controlling the adjustment member 58 can be reduced.
[0084]
Further, the opening / closing direction of the adjustment member 58 may be performed substantially parallel to the axial direction of the injection cylinder 16 as shown in FIG. In that case, the adjustment member 70 has a structure having an operation portion 70a for operating opening and closing on the operation panel 84 side for operating the injection stretch blow molding machine 1.
[0085]
3B, the flow rate of the cooling air passing through the cooling air passage route C and the flow rate of the cooling air passing through the cooling air passage route D are as shown in FIG. Asymmetric with respect to the axis. On the other hand, in the opening / closing direction of FIG. 3C, a symmetric flow can be achieved regardless of the opening degree of the adjustment member 58, and uneven temperature distribution in the circumferential direction of the injection cylinder 16 can be prevented.
[0086]
Furthermore, if the adjustment member 58 is fully closed when the cooling fan 52 is not activated, the adjustment member 58 can also be used as a heat shield that blocks hot air from the heater 22 toward the cooling fan 52.
[0087]
As shown in FIG. 3, the temperature sensor 60 is attached to the lid portion 32 of the cylinder cover 30 for each zone I, II, III, for example, and has a function of measuring the temperature of the injection cylinder 16, such as a thermocouple. These temperature detection elements are mentioned.
[0088]
[3] Regarding the control system of the temperature adjusting device 20
Next, the control system of the temperature adjusting device 20 will be described with reference to FIG. FIG. 7 is a block diagram showing the configuration of the control system of the temperature adjusting device 20 of the present invention.
[0089]
That is, a CPU 64-1 is provided as a control means for controlling the injection stretch blow molding machine 1, and an input / output unit 62, a main storage unit 64-2, and an I / O interface are provided on the bus line 64-3. Various I / O 64-5 are connected via 64-4. Various I / Os 64-5 that are targets in the present embodiment are various control targets 65a such as the heater 22 and the cooling fan 52, and various measurement units 65b such as the temperature sensor 60.
[0090]
The CPU 64-1 starts and stops the cooling fan 52 and the heater 22 for each zone based on the information on the upper and lower limit temperatures of the preset temperature and the measurement information measured by the temperature sensor 60. And at least a function of controlling the temperature change.
[0091]
Specifically, when the upper limit temperature and the lower limit temperature are set in advance for at least the compression zone II and the measurement zone III, and the temperature measured by the temperature sensor 60 provided in the zone II / III exceeds the upper limit temperature, Start-up control of the cooling fans 52 arranged in the corresponding zones II and III, and stop control of the heaters 22, and stop control of the cooling fans 52 arranged in the corresponding zones II and III when the temperature falls below the lower limit temperature. In addition, the activation control of the heater 22 is performed.
[0092]
In the input / output unit 62, various setting conditions including the above-described upper limit temperature and lower limit temperature are input, and can be displayed and confirmed. The input / output unit 62 includes an input unit 62-1a connected to the bus line 64-3 via the interface 62-1c, and an output unit 62- connected to the bus line 64-3 via the interface 62-1d. 1b.
[0093]
Various setting conditions including the above-described upper limit temperature and lower limit temperature set and input from the input unit 62-1a are transferred and stored in the main storage unit 64-2, based on the control of the CPU 64-1. The main storage unit 64-2 has a memory 64-2a connected to the bus line 64-3 via the memory interface 64-2b. In the memory 64-2a, a control program is stored in the ROM in advance, and various setting conditions are stored in the RAM. The CPU 64-1 controls various control targets 65a based on information in the memory 64-2a.
[0094]
An optical communication interface (not shown) may be provided between the bus line 64-3 of the CPU 64-1 and each of the interfaces 64-2b, 62-1c, 62-1d, and 64-4. As a result, the signal on the bus line 64-3 and the signal between the bus line 64-3 and each of the interfaces 64-2b, 62-1c, 62-1d and 64-4 can be optically communicated. It becomes possible, and the occurrence of malfunction can be prevented by reducing the influence of noise superimposed on the signal line.
[0095]
Hereinafter, drive control of the heater 22 and the cooling fan 52 by the CPU 64-1 based on the temperature measured by the temperature sensor 60 will be described.
[0096]
As the heater 22 starts, the measured value of the temperature sensor 60 also increases, and the CPU 64-1 maintains the measured value of the temperature sensor 60 at a set temperature between the set upper limit and lower limit temperature. Is energized. At this time, a constant current may be supplied without performing the energization control of the heater 22.
[0097]
Then, after the measured value of the temperature sensor 60 is in a stable state, preliminary injection molding of the preform is started, and then the injection molding for mass production is started after the molding conditions are stabilized.
[0098]
Here, when the temperature measured by the temperature sensor 60 exceeds the upper limit temperature of the set temperature range input in advance by the control unit 62 due to the above-described shear heat or the like, the CPU 64-1 turns the cooling fan 52 on. Start up and stop the heater 22. Thereby, it can return to within preset temperature below upper limit temperature promptly. Here, even if the heater 22 is turned off, the temperature is in an equilibrium state between the shear heat and the cooling of the cooling fan 52, and the cylinder temperature can be maintained within the set temperature.
[0099]
Should the above equilibrium state break down and the cylinder temperature falls below the lower limit temperature of the set temperature range, the CPU 64-1 stops the cooling fan 52 and activates the heater 22. As a result, it is possible to quickly return to a set temperature equal to or higher than the lower limit temperature.
[0100]
By the on / off control of the cooling fan 52 and the heater 22 as described above, the cylinder temperature can be constantly maintained in a range near the set temperature range. Therefore, the thermal stability of the cylinder temperature can be improved and the quality of the molded product can be improved. In addition, the power consumption of the heater 22 and the cooling fan 52 can be reduced and the running cost can be reduced as compared with the case where the conventional heater and the centrifugal fan are always operated.
[0101]
In the above embodiment, the heater 22 and the cooling fan 52 are simply turned on / off, but the following control may be performed. For example, the CPU 64-1 controls energization of the heater 22 based on the temperature measured by the temperature sensor 60, and does not perform the OFF control of the heater 22 as in the above embodiment. When the temperature becomes higher than the cylinder set temperature due to the shear heat, when the set value becomes lower than the target value (for example, 270 ° C. for PET resin) (for example, 220 ° C. for PET resin), the CPU 64 -1 is set to activate the cooling fan 52. After the temperature rises above the set value, the cooling fan 52 can be always operated so that the set value is not exceeded by shear heat. In this way, the temperature of the cylinder can be controlled only by controlling the heater 22. In this case, it is preferable to use general “PID control” for controlling the heater 22. By performing this PID control, temperature control that is clearer than the on / off control is possible.
[0102]
In addition, when the cooling fan 52 is in operation, the opening rate of the adjustment member 58 can be adjusted to change the cooling rate by the cooling fan 52. In this way, by adjusting the opening of the adjusting member 58, it is possible to change the cooling rate without controlling the driving motor of the cooling fan 52 and performing complicated air volume adjustment, and in particular, responding to fluctuations in the outside air temperature according to the season, day and night Therefore, it is possible to prevent overcooling and appropriately realize a temperature return operation within the set temperature range.
[0103]
By performing the temperature setting as described above preferably in the zones II and III, and more preferably in the zone I, the temperature of the injection cylinder can be appropriately controlled over a plurality of shots. Thereby, the quality of the bottle blow-molded from the preform using the preform and its retained heat can be maintained constant.
[0104]
Furthermore, by adjusting the temperature within the range of the optimum molding temperature, it is possible to eliminate excessive temperature supply in the injection cylinder 16 and not to give an excessive amount of heat to the resin material in the injection cylinder 16. Combustion of molded product due to friction of resin material in cylinder 16 and adiabatic compression of air, black stripes, burns, etc. can be prevented, and further improvement in the quality of the molded product is maintained by maintaining thermal stability. be able to.
[0105]
In addition, this invention is not limited to the said Example, A various deformation | transformation is possible within the range of the summary of invention. For example, the injection device of the present invention is not limited to the above-described injection stretch blow molding machine, and is a blow component that does not have a temperature control station.formThe present invention can also be applied to a machine, an injection blow molding machine, and a general injection molding machine without blow molding. Further, it goes without saying that the injection device of the present invention can be applied regardless of a multi-material injection molding machine using a plurality of injection devices or a system using a plurality of axes.
[0106]
【The invention's effect】
Claim4According to each of the inventions, the cooling efficiency is improved, temperature adjustment can be reliably realized, and the quality of the final molded product can be improved. Even when multiple shots are taken to continuously produce molded products, the molding temperature does not vary between shots, and multiple uniform molded products can be kept in high quality regardless of the number of shots. It can be produced in large quantities while maintaining. In addition, the flat axial fan can be made inconspicuous from the surroundings, resulting in a very neat appearance.
[0107]
Claims5When the adjustment member for adjusting the air flow rate of the cooling fan is provided as in the invention, the temperature can be accurately adjusted by dealing with factors such as the outside air temperature.
[0108]
Claim1In this invention, the power consumption can be reduced and the running cost can be reduced by the start control / stop control of the heater and the cooling fan.
[0109]
Claim2In this invention, if the heater is controlled by, for example, PID control, the cylinder temperature can be more asymptotically approached to a desired set value only by starting the cooling fan, and the set temperature can be kept more constant. It becomes.
[0110]
Claim3In this invention, the partition wall allows the cooling air to flow independently for each zone, improves the cooling efficiency, and accurately reproduces the set temperature for each zone.
[0116]
[Brief description of the drawings]
FIG. 1 is a front view showing the overall structure of an injection stretch blow molding machine according to one embodiment of the present invention.
2 is a view showing a cylinder portion of an injection device of the apparatus of FIG. 1, (A) is a schematic sectional view, and (B) is a bottom view. FIG.
3A is a schematic XX sectional view of FIG. 2A, FIG. 3B is a ZZ sectional view of FIG. 3A, and FIG. It is a cross-sectional view which shows the modification of (B).
FIG. 4A is a schematic longitudinal sectional view of a cylinder portion of an injection device, and is a schematic explanatory view for explaining a cooling air passage route; FIG. 4B is a modified example of a partition wall; It is sectional drawing shown.
5 is a plan view and a front view showing a structure of a cooling fan attached and fixed to the cylinder of FIG. 2, wherein (A) is a type having five blades, and (B) is a type having three blades. Indicates.
6 is a bottom view showing a modified example when the arrangement area of the cooling fan of the embodiment of FIG. 1 is modified. FIG.
FIG. 7 is a block diagram showing a configuration of a control system of the temperature adjusting device of the present invention.
8 is an enlarged plan view of a portion of 4 stations of the injection stretch blow molding machine of FIG. 1. FIG.
9A and 9B are diagrams showing a cylinder portion of an injection device using a conventional centrifugal fan, in which FIG. 9A is a front view and FIG. 9B is a right side view.
[Explanation of symbols]
1 Injection stretch blow molding machine
10 Injection device
16 Injection cylinder
20 Temperature controller
22 Heater
30 Cylinder cover
34 Deaeration holes
42 Cold air introduction hole
52 Cooling fan
54a, 54b Heat-insulating mounting member
58 Adjustment member
60 Temperature sensor
62 Control unit
100 injection molding station
200 temperature control station
300 Stretch blow molding station
400 take-out station
602 Centrifugal fan
612 Heat-resistant hose

Claims (5)

A supply zone for supplying the molding resin material forward, a compression zone for melting and compressing the resin material with heat and pressure, and a measurement zone for measuring the resin material for one shot are provided in order along the axial direction. An injection cylinder;
A temperature sensor for measuring the cylinder temperature for each zone;
A heater that is divided into zones for each of the zones around the injection cylinder;
Based on the temperature measured by the temperature sensor, a controller that controls the heater for each zone;
In an injection cylinder temperature adjusting device of an injection device having
A cylinder cover arranged to cover the periphery of the injection cylinder and the heater;
Deaeration holes formed in the cylinder cover corresponding to the zones;
Cold air introduction holes formed in the cylinder cover corresponding to at least the compression zone and the metering zone;
A cooling fan for introducing cool air into the cylinder cover via the cool air introducing hole;
Provided,
The control unit responds when an upper limit temperature and a lower limit temperature are set in advance for at least the compression zone and the metering zone, and the temperature measured by the temperature sensor provided in the zone exceeds the upper limit temperature. A cylinder temperature adjusting device for an injection device, wherein start-up control of the cooling fan arranged in a zone is performed, and when the temperature falls below the lower limit temperature, the cooling fan arranged in the corresponding zone is stopped. A supply zone for supplying the molding resin material forward, a compression zone for melting and compressing the resin material with heat and pressure, and a measurement zone for measuring the resin material for one shot are provided in order along the axial direction. An injection cylinder;
A temperature sensor for measuring the cylinder temperature for each zone;
A heater that is divided into zones for each of the zones around the injection cylinder;
Based on the temperature measured by the temperature sensor, a controller that controls the heater for each zone and adjusts the cylinder temperature;
In an injection cylinder temperature adjusting device of an injection device having
A cylinder cover arranged to cover the periphery of the injection cylinder and the heater;
Deaeration holes formed in the cylinder cover corresponding to the zones;
Cold air introduction holes formed in the cylinder cover corresponding to at least the compression zone and the metering zone;
A cooling fan for introducing cool air into the cylinder cover via the cool air introducing hole;
Provided,
The controller sets a lower limit temperature in advance for at least the compression zone and the metering zone, and when the temperature measured by the temperature sensor provided in the zone exceeds the lower limit temperature, the control unit is arranged in the corresponding zone. A cylinder temperature adjusting device for an injection device, wherein the cooling fan is activated. In claim 1 or 2 ,
A cylinder temperature control device for an injection device, wherein a partition wall is formed at a boundary of each zone in the cylinder cover. In any one of Claims 1 thru | or 3 ,
A cylinder temperature adjusting device for an injection device, further comprising a heat insulating mounting member interposed between the cylinder cover and the cooling fan for mounting the cooling fan to the cylinder cover. In claim 4 ,
A cylinder temperature adjusting device for an injection device, further comprising an opening / closing adjusting member for adjusting an opening ratio of the cold air introduction hole.

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