JP3550920B2 - Preform integration method and apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a preform accumulation method and an apparatus for accumulating preforms for offline use in a container without damaging the preforms in a PET bottle manufacturing process or the like.
[0002]
[Prior art]
Conventionally, in the production of PET bottles, a preform molding machine for molding a preform and a blow molding machine for blow molding a PET bottle have been paired, and the preform molded by the preform molding machine is a direct blow molding machine. An in-line system in which PET bottles are supplied to manufacture PET bottles is generally employed. However, in the case of the in-line method, the production speed of the preform and the production speed of the PET bottle are constrained to each other and must be adjusted to the lower one of the capacities. In the case of failure or adjustment, there is a problem that the molding of the PET bottle must be stopped. For this reason, recently, an off-line method in which a preform molding machine and a blow molding machine are separated from each other, a preform manufactured by the preform molding machine is temporarily accumulated in a container, and then supplied to the blow molding machine to produce a PET bottle has been developed. Proposed.
[0003]
In this case, the preform molded and discharged by the preform molding machine is cooled to about 60 ° C. at the cooling station while being transported by the preform transport conveyor that supports the flange with two ropes and transports the suspended preform. Then, it is supplied to the gate cutter device to cut and remove the gate projection. The preform discharged from the gate cutter device is transported directly or again in a suspended state to a collecting position and dropped and collected in a container waiting at the position.
[0004]
[Problems to be solved by the invention]
The preform discharged from the gate cutter device is still in a state in which the peripheral surface temperature is high, is soft, easily adheres, and is easily damaged. In particular, when the preform falls into the container from the preform transport conveyor, the preform falls to one location of the container with the impact of the fall, and the preform pile is formed at the fall position, which gradually collapses and collide with each other. It is in a situation where scratches easily occur. In addition, since the container is conventionally held at a fixed position, the falling distance of the preform varies as the accumulation progresses, and the impact received by each preform differs. Cheap. In addition, since the preform has an unstable stack due to the presence of a flange, and also falls and accumulates at one location in the container, the flanges interfere with each other to make the accumulation non-uniform, resulting in poor accumulation efficiency. There was also a problem.
[0005]
An object of the present invention is to solve the above-mentioned problems in handling preforms in the production of PET bottles and the like by an off-line method. To provide a preform collecting method and a preform collecting method capable of automatically and efficiently collecting the preform without dropping the preform without damaging the preform. And
[0006]
[Means for Solving the Problems]
The preform collecting method of the present invention that solves the above problems is a preform collecting method in which preforms are individually dropped into a container and collected, wherein the container is placed on a rotary table on a lifter and a constant speed. The preform is clamped by a grip conveyor so as to be in a horizontal position at least at the preform drop opening, and is conveyed to an upper position deviated from the rotation axis of the container, and deviated from the rotation axis of the rotary table. The preform is dropped from a position in a horizontal state, and the preforms are accumulated in a container. When accumulating the preform in the container, the container is successively lowered so that the distance between the preform accumulation level in the container and the preform drop opening of the grip conveyor is substantially constant, so that the falling distance of the preform is substantially constant. By doing so, it is desirable that the preform be more radially and uniformly integrated within the container. In addition, the preform supplied to the grip conveyor is cooled by cool air while supporting the flange of the preform with a cooling conveyor and suspended in a suspended state to lower the surface temperature of the preform, and then supplied to the grip conveyor. It is desirable to do.
[0007]
Further, a preform accumulating apparatus according to the present invention for carrying out the above accumulating method includes a grip conveyor device for nipping and transporting the preform so that the preform is in a horizontal posture at least at a drop position, and a downstream side of the grip conveyor. A rotary table device that supports the container at the lower end position and rotates at a constant speed, and a lifter device that supports the rotary table device and descends so that the falling distance of the preform into the container becomes substantially constant, The preform dropping opening of the grip conveyor is arranged so as to be shifted from the rotation axis of the rotary table.
[0008]
It is preferable that a preform cooling conveyor having a cooling section for supplying cooling air to at least a part of a conveying path for conveying the preform to cool the preform being conveyed is arranged upstream of the grip conveyor. In addition, a switching conveyor is provided at a relay portion between the cooling conveyor and the grip conveyor device, and a conveyance path of the preform conveyed from the cooling conveyor can be switched between a grip conveyor and an accumulate conveyor, so that a container is provided. Can be continuously performed without stopping the operation of the preform molding apparatus even when the container in which a predetermined amount of the pre-packaged components are accumulated is replaced with an empty container.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an arrangement of a preform accumulating apparatus according to the present invention in a preform molding line. In the drawing, 1 is a preform molding machine, 2 is a cooling room, and the preform is cooled to about 60 ° C. in the cooling room. Reference numeral 3 denotes a preform transport conveyor for supporting and transporting the flange of the preform with two endless ropes, and is gradually inclined upward to the gate cutting device 4. The gate portion formed at the time of molding the preform conveyed by the gate cutting device 4 is automatically cut and removed, and is sent out to the collecting device described below by the preform cooling conveyor 5. The preform is formed of a conveyor similar to the preform conveyor 3 and is arranged with a gentle inclination with a rising gradient toward the downstream side, and a part of the conveyance path is covered with a cover 6 in a tunnel shape. Cool air is blown from the cooling duct 7 into the cover, passes through the cover, and is air-cooled to a predetermined temperature or lower.
[0010]
Reference numeral 8 denotes a switching conveyor for switching and transporting the preform conveyed from the preform cooling conveyor to the accumulating device and the accumulation conveyor 9. As shown in FIG. 2, the switching conveyor is formed in the shape of a chute that supports and transports the flange of the preform, and can switch to a transport path to the accumulating conveyor while exchanging containers in the stacking device. Thus, by having the gate 10 and opening the gate, the preform drops from the transport chute 11 to the stacking device to the branch chute 12 which is arranged to be branched below the preform, and moves toward the accumulation conveyor 9 side. It is designed to be transported.
[0011]
Next, the preform integrating device of the present invention will be described mainly with reference to FIGS. The preform stacking apparatus of this embodiment receives the preform from the main conveyor chute 11 of the switching conveyor 8 in a substantially vertical state (vertical posture), changes the posture from the vertical posture to a horizontal state (horizontal posture), and falls into a container. A grip conveyor 21, a rotary table device 22 that supports a container below the lower end of the grip conveyor and rotates at a constant speed, and a lifter that supports the rotary table device 22 and descends so that the preform falls at a constant position. It comprises a device 23 and a container transport conveyor device 24 for loading and unloading containers onto and from the lifter.
[0012]
As shown in FIG. 5, the grip conveyor 21 is composed of a pair of endless conveyors 26, 26 in which a number of grip pieces 25 formed of an elastic material such as rubber are arranged in parallel and driven synchronously. The body of the preform is lightly held between the pair of grip pieces 25. As shown in FIGS. 2 and 5 (a), the grip conveyor 21 includes an inclined section following the main conveying sheet 11 of the switching conveyor 8, and a vertical section which is circularly descended vertically from the inclined section. The lower end of the section is the preform outlet. As shown in FIG. 2, the preform drop opening 27 is disposed so as to be shifted from the rotation axis m of the rotary table located at the lower part.
[0013]
A preform detector (not shown) is provided at the entrance of the grip conveyor 21 to detect the presence or absence of a preform. Further, a distance sensor (not shown) for detecting the distance to the accumulation level of the preforms accumulated in the container is attached to the conveyor frame near the lower end of the vertical section. The distance sensor employs an ultrasonic sensor in the present embodiment, and is mounted at a position about 70 mm above the lowermost end of the grip conveyor, and a position 135 mm therefrom, that is, a position about 65 mm below the lowermost end of the grip conveyor is a detection position. It is set to be. However, the distance can be arbitrarily selected, and particularly in the case of an ultrasonic sensor, the detection distance can be easily and arbitrarily adjusted in the ultrasonic sensor amplifier. In the present embodiment, as described later, the sensor detects that the integration level has exceeded the set distance by detecting 135 mm or less five times, and the lifter is set so as to descend by one shot (about 30 mm). However, the number of times of detection can be arbitrarily set by an average function in the ultrasonic sensor amplifier. It is desirable that a grip conveyor be provided with an appropriate static eliminator so that electrostatic charging of the preform can be suppressed.
[0014]
As shown in FIGS. 6 and 7, the rotary table device 22 has a rotary table 34 fixed to a lifter table 31 of a lifter device 23 and fixed to the top end of a drive shaft 33 that is driven to rotate at a constant speed by a motor 32. are doing. In the figure, reference numeral 35 denotes a free roller which supports and guides the rotary table, and four rollers are arranged on the base 36 at 90 ° intervals.
[0015]
In the lifter device 23, the rotary table 34 of the rotary table device 22 fixed on the lifter table 31 lifts and places the container on the second conveyor 43 composed of a chain conveyor of the container transport conveyor device 24 for carrying in and out the container. The second conveyor 43 is installed below the chain 38, 38 so as to be able to perform the operation. As shown in FIG. 4, the lifter device is configured such that the distance between the inner bottom surface of the empty container and the distance sensor is at least from the lowest position where the surface of the rotary table 34 is at least lower than the conveying surface of the chains 38, 38. It is driven by an appropriate drive device such as a hydraulic cylinder or the like so that the control device can perform vertical drive control between the highest positions that are the distance set in the distance sensor.
[0016]
Therefore, the lifter table 31 and the rotary table 34 are formed at least shorter in the width direction than the interval between the chains 38 of the second conveyor. In this embodiment, the container 40 is formed in a square cross section as shown by a broken line in FIG. 3, but is formed at least in the width direction larger than the interval between the chains 38, and is supported by the second conveyor. Is transported. In FIG. 4, reference numeral 41 denotes a positioning stopper for positioning and stopping the empty container 40 conveyed from the first conveyor 42 at a point on the second conveyor 43 where the rotary table and the axis coincide. It is operated by an appropriate actuator such as a cylinder (not shown). Reference numeral 44 denotes a third conveyor for carrying out a real container storing the preform. The preferred embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and various design changes can be made.
[0017]
The preform molding apparatus of the present invention is configured as described above, and the preforms are accumulated in the container as follows.
The empty container 40 is conveyed to the second conveyor 43 via the first conveyor 42, is stopped by being positioned by the positioning stopper 41, and in this state, the lifter device 23 is operated. 34 is transferred with its axis aligned with the rotation axis m of the rotary table. When the lifter table is further raised, as shown in FIGS. 2 and 4, the vertical section of the grip conveyor 21 is located in the container, and the distance sensor provided at the lower end of the grip conveyor is connected to the inner bottom surface of the container. When the distance reaches a predetermined distance set in advance, the lifting of the lifter table 31 is stopped, and the lifter table 31 stands by at that position.
[0018]
At this time, when the preform detection sensor provided at the entrance of the grip conveyor 21 detects the presence of the preform, the driving of the grip conveyor 21 is started, and the rotary table device 22 is driven, so that the rotary table 34 starts rotating. .
[0019]
On the other hand, the preform p molded by the preform molding machine is fed to the gate cutting device by the preform conveyor 3 through the cooling chamber 2, and the gate formed at the time of injection molding is cut and removed. The preform p that has passed through the gate cutting device 4 is covered by the cover 6 with a preform cooling conveyor 5 that is gently inclined in an ascending manner and has a gap such that the preform p does not adhere to each other. pass. In the cooling section, cool air is blown from the cooling duct 7 into the tunnel, and the preform is air-cooled. In the present embodiment, the preform having a surface temperature of about 48 ° C. at the inlet of the preform conveyor 5 is cooled by setting the temperature in the duct to 19 ° C. and the cooling time passing through the cooling section to 25 seconds. The surface temperature of the preform could be cooled to about 38 ° C., and the incidence of sticking and flaws between the preforms could be drastically reduced.
[0020]
The preform p conveyed by the preform cooling conveyor 5 is supplied to a switching conveyor 8 composed of a chute at the exit end thereof, slides with the flange supported, and reaches the entrance of the grip conveyor 21. The pair of endless conveyors 26, 26 of the grip conveyor device 21 rotate synchronously by driving sprockets 29, 29 at their downstream ends by a motor 28, and the grip pieces 25, 25 cause the entrance end of the grip conveyor device to rotate. As shown in FIG. 5 (c), the body of the preform p that has reached the position is lightly pinched and transported. In this state, the preform is held in a vertical posture in an inclined state as shown in FIG. 5 (a). However, when the preform gradually falls into a horizontal posture through an arc portion and reaches a vertical section, it is completely converted to a horizontal posture. And reaches the preform dropping port 27 in the horizontal posture, where it is released from the gripping of the grip pieces 25, 25 and falls into the container.
[0021]
At that time, as described above, the container 40 is being rotated at a constant speed by the turntable device, and the preform dropping port is located at a position shifted from the rotation axis of the container, so that the falling preform is placed in the container. Radially accumulated. As a result, the preforms are accumulated circumferentially as a whole, and are not accumulated in one place as in the related art, and it is possible to prevent the preform from being damaged due to sliding down. Further, in this embodiment, the lifter table 39 is set so as to descend by one shot (about 30 mm) by detecting the position 135 mm or less (i.e., the position 65 mm from the preform drop opening) five times by the distance sensor in this embodiment. Therefore, the container descends as the accumulation amount increases, and the falling distance of the preform can always be kept constant. As a result, all the preforms fall under substantially the same conditions during accumulation, and the impact of the fall is small and the preforms are efficiently and uniformly accumulated.
[0022]
When the preform is accumulated in the container up to the accumulation completion position, an accumulation completion detection sensor (not shown) is operated to stop the grip conveyor 21, stop the lowering of the lifter table 31, and stop the rotation of the rotary table. Stop. Next, the lifter table 31 is lowered until a predetermined lower end position is detected, and when the rotary table surface is lowered from the transport surface of the second conveyor, the containers supported by the rotary table are moved to the chains 38, 38 of the second conveyor. The container 45 loaded and filled with the preform in a predetermined amount is carried out onto the third conveyor. In the meantime, the empty container waiting on the first conveyor 42 is supplied onto the second conveyor, and the accumulation operation on the next container is started in the same manner as described above.
[0023]
On the other hand, while the rotation of the grip conveyor 21 stops, the gate 10 of the switching conveyor 8 opens, and the preform conveyance path is switched from the main conveyance chute 11 to the branch chute 12, and the preform passes through the branch chute 11 to the accumulate conveyor. The preform conveyed and conveyed before the next accumulation operation is started is stored in the accumulate conveyor. When the container change is completed and the container is lifted up to a predetermined position, the gate 10 is switched again and the next transfer operation is automatically started.
[0024]
【The invention's effect】
According to the present invention, the preforms are conveyed while being lightly sandwiched by the grip conveyor, so that the preforms can be stably transported to the container collecting position without being damaged, and the preforms are changed to the horizontal posture to be collected while keeping the falling distance constant. The preform can be automatically accumulated without damaging the preform without damaging it. In addition, since the preform is dropped at the eccentric position by rotating the container at a constant speed, the drop position is shifted, the preforms are uniformly collected, and the preforms can be efficiently collected, effectively eliminating the problem of the conventional offline method. Could be solved.
[0025]
In addition, by arranging the preform cooling conveyor on the upstream side of the grip conveyor, the surface temperature of the preform can be reduced, the occurrence rate of scratches can be reduced, and the preforms do not stick together, Can be transported reliably. Furthermore, by providing the switching conveyor at the junction between the cooling conveyor and the grip conveyor device, the preform molding can be continuously performed without stopping the operation of the preform molding device even during container replacement.
[Brief description of the drawings]
FIG. 1 is a plan layout view of a preform forming line of a preform collecting apparatus according to an embodiment of the present invention.
FIG. 2 is a front view thereof.
FIG. 3 is a plan view of the preform integration device according to the embodiment of the present invention.
FIG. 4 is a side view thereof.
5A and 5B show a grip conveyor, wherein FIG. 5A is a front view, FIG. 5B is a side view, and FIG. 5C is a view taken along the line AA of FIG.
FIG. 6 is a side view of the rotary table device.
FIG. 7 is a front view thereof.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Preform molding machine 3 Preform conveyance conveyor 4 Gate cutting device 5 Preform cooling conveyor 6 Cover 7 Cooling duct 8 Switching conveyor 9 Accumulate conveyor 10 Gate 20 Preform integration device 21 Grip conveyor 22 Rotary table device 23 Lifter device 24 Container Transport conveyor device 25 Grip piece 27 Preform drop port 31 Lifter table 34 Rotary table 40 Container 41 Positioning stopper p Preform

Claims (6)

A preform collecting method in which preforms are individually dropped and collected in a container, wherein the container is placed on a rotary table on a lifter and rotated at a constant speed so that at least a preform drop opening is in a horizontal posture. Then, the preform is gripped by a grip conveyor and transported to an upper position offset from the rotation axis of the container, and the preform is dropped in a horizontal state from a position offset from the rotation axis of the rotary table, and is placed in the container. A preform accumulation method, wherein a reform is accumulated. When accumulating the preform in the container, the container is successively lowered so that the distance between the preform accumulation level in the container and the preform drop opening of the grip conveyor is substantially constant, and the preform falling distance is substantially constant. The preform integration method according to claim 1, wherein the preform is stored. The preform supplied to the grip conveyor is transported in a suspended state while supporting a flange of the preform by a cooling conveyor, and the surface temperature of the preform is reduced by cold air before being supplied to the grip conveyor. 3. The preform integration method according to 2. A grip conveyor device for nipping and transporting the preform so that the preform is in a horizontal position at least at a drop position, a rotary table device that supports a container at a position below the downstream end of the grip conveyor and rotates at a constant speed, and A lifter device that supports the table device and descends so that the drop distance of the preform into the container is substantially constant, and the preform drop opening of the grip conveyor is displaced from the rotation axis of the rotary table. A preform integration device characterized in that: The preform cooling conveyor having a cooling section for supplying cooling air to at least a part of a conveyance path for conveying the preform to cool the preform being conveyed is disposed upstream of the grip conveyor. Preform integration device. 6. A switching conveyor is provided at a relay section between the cooling conveyor and the grip conveyor device, and a conveyance path of a preform conveyed from the cooling conveyor can be switched between a grip conveyor and an accumulate conveyor. Preform integration device.

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