阅读说明：本技术 预塑形坯的温度调整装置及温度调整方法 (Temperature adjusting device and temperature adjusting method for pre-molded blank ) 是由 土屋知朗 比田井健 于 2020-04-09 设计创作，主要内容包括：本发明的目的在于提供一种预塑形坯的温度调整装置及温度调整方法,能够根据供给电源的电压变动等自动地变更对预塑形坯进行加热的加热装置及对预塑形坯的气氛温度进行冷却的冷却装置的输出来实现预塑形坯的温度调整。预塑形坯的温度调整装置通过对该预塑形坯进行加热而使预塑形坯温度或其气氛温度上升的加热装置和对该预塑形坯或其气氛进行冷却而使预塑形坯温度或其气氛温度减少的冷却装置对注射成型后的预塑形坯进行温度处理而进行温度调整,并将温度调整后的预塑形坯向吹塑成型工序输送,其特征在于,所述冷却装置及加热装置分别由供给电源供给给定电压的电力而被驱动,所述冷却装置及加热装置具备：监视装置,始终监视所述给定电压的变动；及输出自动控制机构,在由所述监视装置监视到的给定电压超过正常范围变动的情况下,通过使所述加热装置及冷却装置中的至少一方的输出自动地变动而收敛于给定范围,由此将预塑形坯的温度及气氛温度中的至少一方调整成收敛于正常温度范围内。(The invention aims to provide a temperature adjusting device and a temperature adjusting method for a preform, which can automatically change the output of a heating device for heating the preform and a cooling device for cooling the atmosphere temperature of the preform according to the voltage variation of a power supply and the like, thereby realizing the temperature adjustment of the preform. A preform temperature adjusting device that adjusts the temperature of an injection-molded preform by heating the preform to increase the temperature of the preform or the temperature of the atmosphere thereof, and a cooling device that cools the preform or the atmosphere thereof to decrease the temperature of the preform or the temperature of the atmosphere thereof, and that performs temperature adjustment by performing temperature treatment on the injection-molded preform and conveys the temperature-adjusted preform to a blow molding step, wherein the cooling device and the heating device are driven by supplying electric power of a predetermined voltage from a power supply, respectively, and the cooling device and the heating device are provided with: a monitoring device that constantly monitors a variation in the predetermined voltage; and an automatic output control means for adjusting at least one of the temperature of the preform and the atmospheric temperature to fall within a normal temperature range by automatically varying the output of at least one of the heating device and the cooling device to fall within a predetermined range when the predetermined voltage monitored by the monitoring device exceeds a normal range variation.)

1. A temperature adjusting device for a preform, which performs temperature adjustment by temperature treatment by heating the preform after injection molding to raise the temperature of the preform or the temperature of the atmosphere thereof, and a cooling device for cooling the preform or the atmosphere thereof to reduce the temperature of the preform or the temperature of the atmosphere thereof, and which conveys the preform after temperature adjustment to a blow molding process, characterized in that,

the cooling device and the heating device are driven by power supplied by a power supply to a predetermined voltage,

the cooling device and the heating device are provided with: a monitoring device that constantly monitors a variation in the predetermined voltage; and an automatic output control means for adjusting at least one of the temperature of the preform and the atmospheric temperature to fall within a normal temperature range by automatically varying the output of at least one of the heating device and the cooling device to fall within a predetermined range when the predetermined voltage monitored by the monitoring device exceeds a normal range variation.

2. The apparatus for adjusting temperature of preforms as set forth in claim 1,

the automatic output control means changes the outputs of both the heating device and the cooling device at the same time.

3. The apparatus for adjusting the temperature of a preform according to claim 1 or 2,

the cooling device is a blower for controlling the temperature of the preform over a relatively long period of time.

4. The apparatus for adjusting the temperature of a preform according to claim 1 or 2,

the heating device is an infrared heater that controls the temperature of the preform in a relatively short period of time.

5. A temperature control device for preforms, which performs temperature control by subjecting a cup-shaped preform subjected to injection molding to temperature treatment by a heating device and a cooling device, and conveys the preform subjected to temperature control to a blow molding process, wherein the heating device heats the preform to raise the temperature of the preform, the cooling device cools the preform to reduce the temperature of the preform, the temperature control device for preforms is characterized in that,

the cooling device and the heating device are driven by power supplied by a power supply to a predetermined voltage,

the cooling device and the heating device are provided with: a monitoring device for constantly monitoring at least one of the variation of the predetermined voltage, the preform temperature and the atmosphere temperature; and an automatic output control means for adjusting at least one of the temperature of the preform and the ambient temperature to fall within a normal temperature range by automatically varying the output of at least one of the cooling device and the heating device to converge within a predetermined range when the predetermined voltage monitored by the monitoring device exceeds a normal range variation and when an abnormality occurs in blow molding of the preform due to a variation in at least one of the preform temperature and the ambient temperature.

6. The apparatus for adjusting temperature of preforms as set forth in claim 5,

the preform temperature is a temperature of the preform at the time of blow molding, and the atmosphere temperature is a temperature inside the heating device.

7. The apparatus for adjusting the temperature of a preform according to claim 5 or 6,

the automatic output control means (6) changes the outputs of both the heating device and the cooling device at the same time.

8. The apparatus for adjusting the temperature of a preform according to claim 5 or 6,

the cooling device is a blower for controlling the temperature of the preform over a relatively long period of time.

9. The apparatus for adjusting the temperature of a preform according to claim 5 or 6,

the heating device is an infrared heater that controls the temperature of the preform in a relatively short period of time.

10. The apparatus for adjusting the temperature of a preform according to any one of claims 5 to 9,

and graphically displaying the value of at least one of the given voltage, the preform temperature and the atmosphere temperature.

11. A method for adjusting the temperature of a preform, comprising the steps of performing temperature adjustment by subjecting a cup-shaped preform subjected to injection molding to temperature treatment by a heating device and a cooling device, and conveying the preform subjected to temperature adjustment to a blow molding step, wherein the heating device heats the preform and the cooling device cools the preform, and the method for adjusting the temperature of the preform comprises:

supplying a predetermined voltage of driving power from a power supply to the cooling device and the heating device to adjust the temperature of the preform or the atmosphere thereof;

a step of constantly monitoring a predetermined voltage from the power supply source; and

and a step of automatically changing the output of at least one of the cooling device and the heating device so as to fall within a predetermined range when the monitored predetermined voltage exceeds a normal range, thereby adjusting at least one of the temperature of the preform and the atmospheric temperature so as to fall within the normal temperature range.

12. A method for adjusting the temperature of a preform, comprising the steps of performing temperature adjustment by subjecting a cup-shaped preform subjected to injection molding to temperature treatment by a heating device and a cooling device, and conveying the preform subjected to temperature adjustment to a blow molding step, wherein the heating device heats the preform and the cooling device cools the preform, and the method for adjusting the temperature of the preform comprises:

supplying a predetermined voltage of driving power from a power supply to the cooling device and the heating device to adjust the temperature of the preform or the atmosphere thereof;

a step of constantly monitoring at least one of a variation in a predetermined voltage from the power supply, a preform temperature at the time of blow molding, and an atmosphere temperature of the preform at the time of temperature adjustment; and

and a step of adjusting at least one of the temperature of the preform and the ambient temperature to fall within a normal temperature range by automatically changing the output of at least one of the cooling device and the heating device so as to fall within the predetermined range when the monitored predetermined voltage exceeds a normal range and when an abnormality occurs in blow molding of the preform due to a change in the value of at least one of the preform temperature and the ambient temperature.

Technical Field

The present invention relates to a preform temperature adjusting apparatus and a temperature adjusting method in a hot-parison blow molding apparatus. More particularly, the present invention relates to a preform temperature adjusting apparatus and a temperature adjusting method, which can automatically change the output of at least one of a heating device for heating a preform and a cooling device for cooling the preform in accordance with a voltage variation of a power supply to adjust the temperature of the preform.

Background

Conventionally, as an injection stretch blow molding machine, there is known a blow molding device including: a cooling unit that temporarily cools a plurality of preforms after injection-molding the preforms in a batch manner (for example, a batch of 8 preforms × 3 rows — 24 preforms); a temperature adjustment unit for switching the batch type to the continuous type to convey the preform, heating the preform by the heating unit, and adjusting the temperature of the preform by preventing overheating by the cooling unit; and a blow molding section for blow molding the temperature-adjusted preform (details are shown in fig. 1 described later).

In the hot parison blow molding method, as a molding method capable of producing a transparent preform or container satisfactorily even if the injection molding time (particularly, cooling time) is significantly shortened, a high-quality container can be produced in the injection stretch blow molding machine with a shorter molding cycle time (high cycle) than in the conventional method.

However, if the blow molding machine is operated at a high cycle, it is more difficult to continuously mold and produce containers with constant quality than ever before. That is, in order to improve the molding/production stability, it is necessary to control the blow molding machine more accurately and precisely, and in particular, further improvement of the method for controlling the temperature adjustment section of the preform is required.

For example, the heating device of the heating section is provided on the preform conveying line, and heats the preform passing through the device by an infrared heater, for example.

However, if the atmosphere in the heating apparatus is excessively or gradually increased, the temperature distribution of the preform becomes uneven, and therefore there are the following techniques: cooling air from a blower (air blower) serving as a cooling device is blown to the preform to cool the preform, and air in the heating device is dissipated to the outside to suppress temperature rise in the device.

For example, there are the following techniques: the preform is cooled by cooling air blown out from an air outlet into the heating furnace, and a metal mesh for adjusting the temperature in the heating furnace by dissipating the air of the heating furnace outside the furnace is provided on the top surface (upper portion) of the heating furnace (see patent document 1). In addition, for example, there are techniques as follows: the inside of a duct for conveying preforms is depressurized by a blower, whereby cooling air is introduced into the duct and air heated in the duct is discharged (see patent document 2).

Moreover, there are also techniques of: an infrared heater and a blower are provided in a casing of a heating device, the preform is heated by the infrared heater, and an excessive rise in the atmospheric temperature of the heating device is suppressed by cooling air from the blower. (see patent document 3)

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2012 and 2458753

Patent document 2: japanese examined patent publication No. 04-12212

Patent document 3: WO2014/208693

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional heating device, when the voltages of the power supplies to the infrared heater and the blower greatly vary, the outputs of the infrared heater and the blower tend to follow the variation of the voltages greatly. For example, when the output of the infrared heater is reduced and heating is insufficient, the preform becomes a low temperature state and the temperature distribution becomes uneven. Thus, the preform (particularly, a preform for a thin-walled/lightweight container, which is subjected to a large stretch ratio) is easily broken at the time of blow molding. In addition, water droplets (moisture) in the vicinity of the surface of the molding apparatus or the blow mold condensed due to the blow gas at the time of the preform breakage are scattered and attached to the subsequent preform, thereby further lowering the preform temperature and facilitating the breakage of the subsequent preform at the time of the blow molding. That is, in the conventional heating apparatus (blow molding apparatus), there is a problem that molding defects such as cracks are likely to occur continuously due to voltage fluctuations.

Further, if the temperature distribution in the heating device becomes uneven, the temperature distribution among the preforms becomes uneven, and even if the preforms are continuously blow molded in the subsequent blow molding step, containers of constant quality cannot be obtained. In particular, when a thin/light container is obtained by blow molding under high cycle conditions, the fraction defective increases due to a slight temperature difference between preforms.

The purpose of the present invention is to automatically change the outputs of a heating device and a cooling device so as to converge them within a predetermined range, regardless of the voltage variation of a power supply, thereby heating the preforms so that the temperature distribution of the preforms becomes uniform, regardless of the voltage variation of the power supply, and achieving good moldability and productivity in blow molding.

Means for solving the problems

The temperature adjusting device for preforms of the present invention is a temperature adjusting device for adjusting the temperature of a preform by heating the preform after injection molding or by raising the temperature of the preform or the temperature of the atmosphere thereof, and a temperature adjusting device for cooling the preform or the atmosphere thereof to reduce the temperature of the preform or the temperature of the atmosphere thereof by temperature treatment, and for transferring the preform after temperature adjustment to a blow molding step,

the cooling device and the heating device are driven by power supplied by a power supply to a predetermined voltage,

the cooling device and the heating device are provided with: a monitoring device that constantly monitors a variation in the predetermined voltage; and an automatic output control means for adjusting at least one of the temperature of the preform and the atmospheric temperature to fall within a normal temperature range by automatically varying the output of at least one of the heating device and the cooling device to fall within a predetermined range when the predetermined voltage monitored by the monitoring device exceeds a normal range variation.

Preferably, the output automatic control means changes the outputs of both the heating device and the cooling device at the same time.

Further, preferably, the cooling means is a blower for controlling the temperature of the preform for a relatively long period of time.

Further, it is preferable that the heating means is an infrared heater for controlling the temperature of the preform in a relatively short period of time.

The present invention is a preform temperature adjusting apparatus for adjusting a temperature of a cup-shaped preform after injection molding by subjecting the preform to a temperature treatment by a heating device for heating the preform to increase the temperature of the preform and a cooling device for cooling the preform to decrease the temperature of the preform, and conveying the preform after the temperature adjustment to a blow molding process,

the cooling device and the heating device are driven by power supplied by a power supply to a predetermined voltage,

the cooling device and the heating device are provided with: a monitoring device for constantly monitoring at least one of the variation of the predetermined voltage, the preform temperature and the atmosphere temperature; and an automatic output control means for adjusting at least one of the temperature of the preform and the ambient temperature to fall within a normal temperature range by automatically varying the output of at least one of the cooling device and the heating device to converge within a predetermined range when the predetermined voltage monitored by the monitoring device exceeds a normal range variation and when an abnormality occurs in blow molding of the preform due to a variation in at least one of the preform temperature and the ambient temperature.

Preferably, the preform temperature is a temperature of the preform at the time of blow molding, and the atmosphere temperature is a temperature inside the heating device.

Preferably, the output automatic control means changes the outputs of both the heating device and the cooling device at the same time.

More preferably, the cooling means is a blower for controlling the temperature of the preform over a relatively long period of time.

More preferably, the heating means is an infrared heater that controls the temperature of the preform for a relatively short period of time.

More preferably, the values of at least one of the given voltage, the preform temperature and the atmosphere temperature are graphically displayed.

The present invention is a method for adjusting the temperature of a preform, comprising the steps of performing temperature adjustment by subjecting a cup-shaped preform after injection molding to temperature treatment by a heating device for heating the preform and a cooling device for cooling the preform, and conveying the preform (200) after the temperature adjustment to a blow molding process, wherein the method for adjusting the temperature of the preform comprises:

supplying a predetermined voltage of driving power from a power supply to the cooling device and the heating device to adjust the temperature of the preform or the atmosphere thereof;

a step of constantly monitoring a predetermined voltage from the power supply source; and

and a step of automatically changing the output of at least one of the cooling device and the heating device so as to fall within a predetermined range when the monitored predetermined voltage exceeds a normal range, thereby adjusting at least one of the temperature of the preform and the atmospheric temperature so as to fall within the normal temperature range.

The present invention is a method for adjusting the temperature of a preform, comprising the steps of performing temperature treatment on a cup-shaped preform after injection molding by a heating device for heating the preform and a cooling device for cooling the preform, and conveying the preform after temperature adjustment to a blow molding process, wherein the method for adjusting the temperature of the preform comprises:

supplying a predetermined voltage of driving power from a power supply to the cooling device and the heating device to adjust the temperature of the preform or the atmosphere thereof;

a step of constantly monitoring at least one of a variation in a predetermined voltage from the power supply, a preform temperature at the time of blow molding, and an atmosphere temperature of the preform at the time of temperature adjustment; and

when the monitored predetermined voltage exceeds a normal range and when an abnormality occurs in blow molding of the preform due to a variation in the value of at least one of the preform temperature and the ambient temperature, the output of at least one of the cooling device and the heating device is automatically varied so as to fall within the predetermined range, and at least one of the temperature of the preform and the ambient temperature is adjusted so as to fall within the normal temperature range.

Effects of the invention

According to the present invention, even when the voltage of the power supply fluctuates excessively, the outputs of the heating device and the cooling device of the preform are automatically changed to be within a predetermined range, so that the temperature distribution of the preform can be made uniform regardless of the fluctuation of the voltage of the power supply, and satisfactory blow molding of the preform can be performed.

Drawings

Fig. 1 is a plan view of a blow molding apparatus to which an example of a preform temperature adjusting apparatus according to an embodiment of the present invention is applied.

Fig. 2 is a top sectional view of the heating device of the blow molding device.

FIG. 3 is a side cross-sectional view of the heating device of the blow molding device.

Fig. 4 is a front sectional view of the heating device of the blow molding device.

FIG. 5 is a cross-sectional view showing a preform and a finished container molded by the blow molding apparatus.

Fig. 6 is a diagram showing a control panel for controlling the operation of the temperature control device.

Fig. 7 is a view showing a first switching screen (first preform temperature monitoring screen) of the control panel of fig. 7.

Fig. 8 is a view showing a second switching screen (second preform temperature monitoring screen) of the control panel of fig. 7.

Fig. 9 is a diagram showing a third switching screen (automatic blower output setting screen) of the control panel of fig. 7.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a plan view of a blow molding apparatus to which an example of a preform temperature adjusting apparatus according to an embodiment of the present invention is applied, and fig. 2 to 4 are a plan sectional view, a side sectional view, and a front sectional view of a heating device of the blow molding apparatus, respectively.

As shown in fig. 1, the blow molding apparatus 100 according to the present embodiment includes, on a base 31: an injection molding section 120 for simultaneously injection molding a plurality of preforms 200 (for example, 24 preforms 200 (each of 3 rows 200a, 200b, and 200c in fig. 1 is composed of 8 preforms) in this order); a cooling unit 140 for cooling the preform 200 molded by the injection molding unit 120; a heating unit (temperature adjustment unit, heating device) 160 for heating the preform 200; and a blow molding section 180 for blow molding the preform 200 to obtain a container. As shown in fig. 5, each preform 200 has a cup shape with a bottom having an axis Z, and has a wall portion (body portion) 202, a reservoir portion 203 in the wall portion 202, a neck portion 204, a gate portion 205, and a bottom portion 206, and the blow molding portion 180 is inflated by blowing air into the reservoir portion 203 to form a container 200A such as a PET bottle.

The blow molding apparatus 100 further includes an endless conveyor line 191 that circulates from the cooling unit 140 to the heating unit 160 and the blow molding unit 180 by being driven by a plurality of sprockets 193. The preform 200 is transported from the cooling section 140 to the heating device 160 by the transport line 191, and the preform 200 heated by the heating device 160 is transported to the blow molding section 180.

The present invention is also characterized by the configuration of the heating device 160 provided in the blow molding device 100. As a part of the configuration of the heating device 160, a voltage detector 199 for detecting a voltage variation of a power supply and a control panel (monitoring device) 1 are also provided in the blow molding device 100. Other structures such as the injection molding section 120, the cooling section 140, and the blow molding section 180 are well known, and therefore, they will be briefly described here.

As described above, the injection molding unit 120 can simultaneously mold the preforms 200 of the first lot number, for example, 24 (3 rows 200a to 200c × 8) by the injection device 125 (see fig. 1). Further, the number of the rows is not limited to 24, but may be 36 (3 columns × 12) or another number of the batches, or may be a number of the columns other than 3 columns.

The cooling unit 140 forcibly cools the first batch number of preforms 200 after injection molding.

The preform 200 is molded in the injection molding section 120 in an upright state with the neck portion facing upward and conveyed, but is inverted in the cooling section 140 in an inverted state with the neck portion facing downward and held by the conveying jig 192 provided in the conveying section 190 in this state.

In the transfer line 191, since the plurality of transfer jigs 192 are successively and sequentially fed out while holding the preforms 200, the preforms 200 are transferred along the transfer line 191 and carried into the heating device 160.

In the heating device 160, the preform 200 is heated to a suitable temperature for stretching while being conveyed along the conveyance line 191. Further, since the preform 200 is conveyed on the conveyor line 191 while rotating on its own axis, it can be heated to a substantially uniform temperature over the entire circumference of the preform.

Here, the portion of the transport line 191 where the heating device 160 is provided is constituted by: a first linear portion 194 for linearly conveying the conveying jig 192 in the direction of arrow a in fig. 1; a second linear portion 195 which is located on the same horizontal plane as the first linear portion 194 and linearly conveys the conveying jig 192 in the direction of arrow B opposite to the direction of arrow a; and a bent portion 196 formed in a substantially circular arc shape and connecting the two linear portions 194 and 195.

In the blow molding section 180, as shown in fig. 1, the preforms 200 are blow molded in units of a second batch number, for example, a set of 8 preforms, to obtain containers 200A. The second batch number is preferably set within the range of 1/2 to 1/4, and particularly preferably set to 1/3, of the first batch number.

Next, the details of the heating device 160 will be described. As shown in fig. 2, in the heating device 160, a plurality of (for example, 5) heating boxes 161(161A to 161E) in which the heating unit 162 is housed are arranged in two rows. Specifically, the first and second heating boxes 161A and 161B are arranged side by side in the first straight portion 194 to constitute the first heating device 160a, and the third to fifth heating boxes 161C to 161E are arranged side by side in the second straight portion 195 to constitute the second heating device 160B. The heating device 160 includes an exhaust portion 163 at a position corresponding to the bent portion 196, and the second heating box 161B of the first heating device 160a and the third heating box 161C of the second heating device 160B are connected via the exhaust portion 163.

As shown in fig. 4, reference numeral 164 denotes a cover member, which extends to cover three surfaces, i.e., both side surfaces and an upper surface of the transfer line 191, in each of the heating boxes 161(161A to 161E), and defines a transfer space 165 for transferring the preform 200. The heating unit 162 is disposed between the two rows of conveyed preforms 200 in the conveying space 165 of the hood part 164. In addition, the cover member 164 is provided with a discharge pipe 171 for discharging the atmosphere (air) in the heating device 160 to the outside.

Each heating unit 162 includes a heater (infrared heater, heater) 166 (see fig. 3) extending in the conveying direction of the preform 200 and arranged in a plurality of (for example, 8) layers in the vertical direction. In addition, an atmosphere (air) heated to a given temperature by the heater 166 exists in the conveyance space 165 inside each heating box 161.

The preforms 200 are sequentially conveyed in the conveying space 165 while rotating in the heating devices 160, and are heated to a suitable stretching temperature by the atmosphere (air) in the conveying space 165 of the plurality of heating units 162 (heaters 166) and the heating box 161, and a suitable temperature distribution is given in the axial direction thereof.

In fig. 3 and 4, reference numerals 167 and 172 denote first and second blowers (a blower, a cooling device, and a cooling blower) provided in connection with the heating device 160. The first blower 167 supplies cooling air to the conveyance space 165 of each heating box 161 via the supply pipe 168 and the air supply space 169 (see fig. 4 in particular), thereby cooling the preform 200 and the infrared heater 166. Second blower 172 is connected to discharge pipe 171, and discharges the atmosphere (air) in heating unit 162 or the heated cooling air (warm air) to the outside, in the same manner as in exhaust unit 163 (see fig. 2 and 3), thereby suppressing the temperature rise in heating box 161.

In the configuration of the present embodiment, as shown in fig. 4, the cooling air supplied to the air blowing space 169 passes through the gaps between the heaters 166 of the heating unit 162 from the inner surface side of the heating unit 162 to the outer side, and reaches the surface of the preform 200 in the conveying space 165. That is, in the heating apparatus 160 according to the present embodiment, when the preform 200 is heated to the stretching appropriate temperature, the preform 200 is cooled by the cooling air, and the surfaces of the heaters are also cooled.

The cooling air (warm air) having a temperature increased by cooling the preform 200 and the like is gathered with the atmosphere (air) in the heating box 161, and then discharged to the outside from the discharge pipe 171 by the second blower 172. This suppresses excessive temperature rise of the atmosphere (air) in the heating box 161, and the temperature is maintained at a predetermined temperature.

In addition, the following characteristics are provided: the temperature of the heated atmosphere by the heater 166 may be changed in a relatively short period of time, but the temperature of the cooled atmosphere by the first and second blowers 167, 172 may be changed in a relatively long period of time.

Here, in the heater 166 of the heating device 160 and the first and second fans 167 and 172 for cooling, when the supply voltage of the power supply from the factory greatly varies, the outputs of the heater 166 and the fans 167 and 172 for cooling also greatly vary. For example, if the supply voltage is excessively varied in the negative direction (the voltage is excessively decreased), the heating output of the heater 166 is decreased, and the flow rate output of the cooling blowers 167 and 172 is also decreased, so that the cooling capacity is also decreased. Therefore, the temperature distribution of the conveyed preform 200 becomes uneven (nonuniform) or is not suitable for blow molding, and favorable blow molding cannot be performed in the subsequent blow molding step.

For example, if the temperature of the preform is lowered and the temperature distribution of the preform becomes uneven as described above, the preform is likely to be broken when blow-molded in the subsequent step. Further, there is a problem that water droplets (moisture) in the vicinity of the surface of the molding apparatus or the blow mold condensed by the blow gas at the time of breakage of the preform are scattered and attached to the subsequent preform, thereby further lowering the preform temperature and causing molding defects such as breakage to easily occur continuously. The present invention is intended to solve the above problems, and the structure and operation thereof will be described below.

Fig. 6 to 9 are screens of a control panel for explaining the configuration and operation of the present invention. In the following description, the "preform temperature" refers to the temperature of the preform immediately before blow molding, which is measured by the temperature sensor 198 in fig. 1, and the "atmosphere temperature (or heater zone temperature)" refers to the atmosphere temperature inside the heating apparatus 160, which is measured by the temperature sensor 197 in fig. 1.

In the control panel (monitoring device) 1 shown in fig. 1 and 6, 2 is a preform temperature setting region, 3 is a blower operation display setting region, 4 is a heater region temperature display region (a display region for heating the atmospheric temperature, a display region for the atmospheric temperature in the heating device 160 (heating box 161)), and 5 is a heater output setting region for individually setting the output of the heater 166 corresponding to each part of the preform, and is used when an automatic heater output control button 6, which will be described later, of the preform temperature setting region 2 is turned off. Reference numeral 6 denotes an automatic heater output control button (automatic heater output control means: automatic output control means of the heating apparatus), and when the button is turned on, the output of the infrared heater 166 is automatically changed in accordance with the voltage variation of the power supply. Reference numeral 7 denotes a preform temperature confirmation button, and when this button is pressed, the screen is switched to the screen (first preform temperature monitoring screen) of fig. 7. In addition, in the blower operation setting display area 3 in fig. 6, a blower automatic control button (a blower output automatic control means: an output automatic control means of a cooling device) of an individual output setting field of the blowers 167, 172 and 8 is provided. When the blower automatic control button 8 is pressed, the screen is switched to the screen (automatic blower output setting screen) of fig. 9. Reference numeral 21 denotes a molding condition selection button for switching an input screen for various set values and a display screen for actual measurement values in the injection molding unit 120, the heater 166, and the like. By selecting the "heater 2" button of the molding condition selection buttons 12, the heating apparatus control screen of fig. 6 is displayed on the control panel 1.

Next, fig. 7 (first preform temperature monitoring screen) will be described. In fig. 7, 9 is a heater zone temperature detailed display region (a detailed display region of the heating atmosphere temperature, and a detailed display region of the atmosphere temperature in the heating device 160 (the heating box 161)), and in the temperature display portion 10, the average atmosphere temperature (vertical axis) in the unit of the heating device 160 is represented by a change in time (horizontal axis, more specifically, one injection molding cycle unit) with the time taken for one injection molding (injection molding cycle) as one unit. The temperature of the heater area temperature detail display area 9 (i.e., the temperature of the atmosphere in the heating device 160) is measured by a temperature sensor 197 (see fig. 1) that measures the temperature at a predetermined position in the heating device 160. Further, reference numeral 11 denotes a preform temperature display region, which is composed of a first temperature display unit 12a and a second temperature display unit 12 b. In the first temperature display unit 12a, the change in the average temperature (vertical axis) of 24 preforms (8 × 3 rows) that are the number of batches injected by the injection molding unit 120 is expressed in one injection molding (injection molding cycle) unit and in accordance with the change in time (horizontal axis, more specifically, one injection molding cycle unit). In the second temperature display unit 12b, the average temperature (vertical axis) of 8 preforms blow-molded by the blow molding unit 180 is represented by a change in time (horizontal axis, more specifically, one blow molding cycle unit) per one blow molding (blow molding cycle). The preform temperature is measured by a temperature sensor 198 (see fig. 1, disposed immediately before the blow molding section 180) for measuring the temperature of the preform during blow molding. Therefore, in the case where a failure occurs in blow molding in the screen of fig. 7, it is possible to grasp whether the heating of the preform by the atmosphere of the heating device 160 is appropriate or abnormal. Further, numeral 13 denotes a button for switching the control panel 1 to the screen (second preform temperature monitoring screen) of fig. 8.

Next, fig. 8 (second preform temperature monitoring screen) will be explained. In fig. 8, 14 is a voltage display region, and in the voltage variation display unit 15, a change in voltage (vertical axis) at the time of injection molding is shown in accordance with a change in time (horizontal axis, more specifically, a unit of one injection molding cycle) for one injection molding (injection molding cycle). Further, 16 is a preform temperature display region, and in the third temperature display portion 17, the change in the average temperature (vertical axis) of 24 preforms (8 × 3 rows) which are the number of injection lots is expressed in one unit of one injection molding (injection molding cycle) in accordance with the change in time (horizontal axis, more specifically, one injection molding cycle unit). Therefore, in the screen of fig. 8, the voltage variation and the preform temperature are compared, and the cause of the blow molding failure can be estimated.

Next, an automatic blower output setting screen of fig. 9 will be described. In fig. 9, when the blower automatic control button 8 of the blower operation setting display area 3 of fig. 6 is pressed, it is displayed in the right half area of the drawing. In fig. 9, the left half has the same configuration as that of fig. 6, and the right half 22 is an automatic control area of the blower, and various parameters can be changed by the touch panel button 23. In the blower automatic control display area 22, for example, a target value of the atmospheric temperature in the heating device 160 (heating box 161), a temperature difference between the target value and the target value at the time of starting the automatic operation of the blower (or an upper limit temperature or a lower limit temperature of the atmospheric temperature at the time of starting the automatic operation of the blower), a time interval for measuring the atmospheric temperature in the heating device 160 (heating box 161), and the like are set. Further, since the blowers 167 and 172 automatically control the output by monitoring the ambient temperature in accordance with the setting conditions shown in fig. 9, the separate output setting fields of the blowers 167 and 172 do not need to be input.

Next, the operations of fig. 6 to 9 will be described.

First, in the preform temperature setting region 2 of the control panel 1 of fig. 6, the temperature (target value) of the preform 200 immediately before blow molding, the temperature (start value) of the preform 200 when the output of the heater 166 is automatically started, and the upper limit value and the lower limit value of the temperature of the preform 200 immediately before blow molding are set. The actual measurement value is shown on the left side of the target value.

As described above, when the supply voltage from the power supply fluctuates greatly beyond the normal range (within the ranges of the upper limit value and the lower limit value of the supply voltage indicated by 15 in fig. 8) by the heater output automatic control means, the automatic heater output control button 6 in fig. 6 is pressed. Then, the heating output of the heater 166 is automatically changed (the heating output is increased at a low voltage and decreased at a high voltage) in accordance with the change of the supply voltage, and the preform 200 is heated so that the temperature thereof falls within a normal range (that is, within a range between an upper limit value and a lower limit value of the heated preform temperature indicated by 11 in fig. 7 or 16 in fig. 8). Therefore, even when voltage fluctuation occurs, the same heating amount (power consumption amount of the heater 166) as that in the case where there is no voltage fluctuation can be supplied to the preforms 200, and the temperature distribution of the plurality of conveyed preforms 200 can be made uniform. The process of the output fluctuation of the heater 166 (the process of the heater output automatic control means) at the time of the voltage fluctuation is performed for a relatively short period of time (within several injection molding cycles, or immediately (within one minute, for example) when the voltage fluctuation occurs).

Then, when the atmospheric temperature of the heating device 160 fluctuates beyond the normal range (that is, within the range of the upper limit value and the lower limit value of the heater zone temperature indicated by 9 in fig. 7) such as a case where a long-term voltage fluctuation occurs, the blower output automatic control means presses the blower automatic control button 8 in fig. 6. Then, the outputs of the blowers 167, 172 automatically change, and the ambient temperature of the heating device 160 is adjusted so as to fall within the above-described normal range. Thus, even when voltage fluctuation occurs or voltage fluctuation is extended, the atmospheric temperature of the heating device 160 can be kept substantially constant, and the heating conditions of the preform 200 can be further uniformized. The process of the output fluctuation of the blowers 167, 172 (the operation of the blower output automatic control mechanism) under the long-term voltage fluctuation is performed for a relatively long period of time. That is, the molding is performed in a continuous molding cycle (for example, 10 or more injection molding cycles) or a continuous operation for several hours (for example, 8 or more hours).

In the above embodiment, the heater 166 adjusts the preform temperature and the blowers 167 and 172 adjust the atmosphere temperature, but it goes without saying that the heater 166 may adjust the atmosphere temperature and the blowers 167 and 172 may adjust the preform temperature, or the heater 166 and the blowers 167 and 172 may adjust both the preform temperature and the atmosphere temperature.

This eliminates the possibility that the preform 200 is broken during blow molding or water droplets are scattered and attached to the subsequent preform 200, and a good container can be obtained.

At this time, when the preform temperature confirmation button 7 in fig. 6 is pressed, the panel 1 is switched to the screen in fig. 7. Thus, the heater zone temperature display area 9 can check the change in the atmospheric temperature in the heating device 160 by a graph display, and the display portions 12a and 12b of the preform temperature display area 11 can monitor the temperatures of 24 preforms 200, which are the number of injection batches, and the temperatures of 8 preforms, which are the number of blow batches, to thereby grasp the suitability of heating of the preforms 200 based on the atmospheric temperature. Therefore, the influence of the change in the atmospheric temperature in the heating device 160 due to the long-term voltage change on the heating condition (for example, insufficient heating) of the preform 200 can be continuously checked in real time, and the cause of the blow molding failure can be estimated.

Next, when the switch button 13 in fig. 7 is pressed, the panel 1 switches to the screen of fig. 8. Thus, the voltage fluctuation display unit 15 of the voltage display area 14 can display the voltage fluctuation at the time of injection molding, and the temperature display unit 17 of the preform temperature display area 16 can monitor the transition of the average temperature of 24 preforms, which is the number of injection batches. This makes it possible to determine the suitability of the heater 166 for heating the preform during voltage fluctuation. Therefore, the influence of the output variation of the heater 166 due to the voltage variation on the heating condition (for example, insufficient heating) of the preform can be continuously checked in real time, and the cause of the blow molding failure can be estimated. In addition, when the screen switching button 18 in fig. 8 is pressed, the screen of fig. 7 is restored.

Thus, in addition to the above-described measures against the variation in the predetermined voltage of the power supply, the precision of the blow molding of the preform can be further improved by constantly monitoring the variation in the value of one or both of the preform temperature and the atmospheric temperature in association with the product precision of the blow molding of the preform.

While one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and modifications, improvements, and the like can be appropriately and freely made. The material, shape, size, numerical value, form, number, arrangement location, and the like of each component in the above embodiments are arbitrary and are not limited as long as the present invention can be realized.

For example, the automatic heater output control button 6 (heater output automatic control means) may be provided on the screen of fig. 7 or 8, and the blower automatic control button 8 (blower output automatic control means) may be provided on the screen of fig. 7 or 8.

Description of the symbols

1 control panel (monitoring device)

2 preform temperature setting zone

3 blower operation display setting area

4 heater zone temperature display zone (display zone of heating atmosphere temperature)

5 automatic control display area for pre-shaped blank

6 automatic heater output control button

7 temperature confirmation button for pre-molded blank

8 automatic control button of blower

9 heater zone temperature detailed display zone (detailed display zone of heating atmosphere temperature)

10. 12a, 12b, 17 temperature display part

11. 16 preform temperature display area

15 voltage fluctuation display part

13. 18, 21 switching button

14 voltage display area

21 Molding condition selection button

22 blower automatic control area

23 touch Panel button

31 machine table

100 blow molding device

120 injection molding part

125 injection device

140 preform cooling section

160(160a, 160b) heating part (heating means)

161 (161A-161E) heating box

162 heating unit

163 air exhaust part

164 cover component

165 transport space

166 heater

167. 172 blower

168 supply pipe

169 (169A-169C) air supply space

171 exhaust pipe

180 blow molded part

191 conveying line

192 conveying clamp

193 sprocket

194 first straight line portion

195 second straight line part

196 curved part

197. 198 temperature sensor

199 Voltage Detector

200 preform

200a, 200b, 200c preform rows

200A container

202 wall portion (body portion)

203 reservoir

204 neck part

205 gate portion

206 at the bottom.