JP2007136820A - Device for detecting erroneous demolding of injection-molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for detecting the erroneous demolding of an injection-molded product which can surely detect whether all the products such as preforms are transferred from a mold to a demolding machine or not. <P>SOLUTION: The erroneous demolding of an injection-molded preform 10 is detected by the device when the preform 10 is taken out from the mold 1 to the demolding machine 2. A laser measuring instrument 4 composed of a sensor 4a emitting/receiving laser beams 5 and a reflection mirror 4b reflecting the laser beams is installed in the direction perpendicular to the moving direction of the demolding machine 2, which received the preform 10 at its one end, to the next process. When the demolding machine 2 is moved to the next process, a prescribed position of the mold surface is scanned by the laser beams 5 to detect of the erroneous demolding of the preform 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an injection molding product take-out detection device that can reliably detect whether a molded product such as an injection-molded preform has been transferred from an injection mold to a whole take-out device.

Conventionally, for example, a thin-walled packaging container made of a synthetic resin that is biaxially stretched and blow-molded, such as a PET (polyethylene terephthalate) container, is a preliminary injection-molded product called a preform in a blow mold. It is formed by stretching the container in the axial direction and expanding it in the direction perpendicular to the axial direction.
In this case, several tens of the preforms are molded at a time by a disk-shaped injection mold, and then transferred from the mold to a disk-shaped vacuum suction-type take-out device, and injection is performed by moving the take-out device. The molded preform is transported to the next temperature control station and blow molding die.

  However, there is no problem if the total number of preforms is reliably transferred to the take-out device, but the injection mold is not transferred to the take-out device due to a shortage of resin injection amount, which is rarely called a short shot. In some cases, it remained in the mold. As a result, the preform remaining in the mold is solidified, and when the mold is clamped in the next molding cycle, the mold collides with the mold and damages the mold. there were. Further, the breakage of the mold forced the stop of the molding machine and the long-time repair work, so that the production efficiency was remarkably lowered.

  Therefore, as a device for detecting an injection molding product take-out error, as shown in Patent Document 1, the number of preforms separated from the injection mold and held in the take-out device is detected, and the number is determined as an injection. There has been proposed a technique in which an injection mold is clamped to prepare for the next molding cycle only when the number is the same as the number molded by a molding mold. However, in order to count the total number of preforms, a plurality of sensors are required, which is expensive and takes a long time for setting the sensors.

In addition, if there is a mistake in taking out the injection-molded product, the mold or take-out device cannot be returned to the normal position. Therefore, the position at the time of return is detected by a sensor, and injection molding is performed depending on whether or not the position has returned to the normal position. An apparatus for detecting the presence or absence of a product take-out error is also considered. However, in this case as well, there are problems that a plurality of sensors are necessary and expensive, and the setting time becomes long. Further, since the sensor is installed in the mold and always stays in the mold area, the optical When the sensor is used, there is a problem that it may become dirty and malfunction due to scattering of grease or the like.
Patent No. 2324323

  The present invention solves the above problems and can accurately detect whether or not there is a mistake in taking out the injection-molded product with only one sensor, and the setting time is short, and further, grease etc. The present invention has been completed for the purpose of providing a detection error detection device for an injection molded product that can also prevent malfunction due to splashing.

  The injection molding product take-out detection device of the present invention, which has been made to solve the above-mentioned problems, detects a take-out error from the mold of the preform when the injection molded preform is taken out from the mold. A sensor for projecting and receiving a laser beam in a direction orthogonal to the direction in which the take-out device that has received the preform at one end of the take-out device moves to the next process. And a laser measuring device comprising a reflection mirror for reflecting the laser beam, and when the take-out device moves to the next process, a predetermined position on the mold surface is scanned by the laser beam to detect a take-out error of the preform. It is characterized by doing so.

  The present invention relates to a laser measuring instrument comprising a sensor for projecting and receiving a laser beam in a direction orthogonal to the direction in which the take-out device that has received the preform at one end of the take-out device moves to the next process and a reflection mirror that reflects this laser beam. It is possible to accurately detect whether or not there is a mistake in taking out the injection molded product with only one sensor. Further, since the laser measuring instrument is not provided on the mold side as in the prior art, contamination due to scattering of grease and the like is eliminated, and malfunction can be eliminated.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
The drawings show the case where the present invention is applied to an apparatus for detecting an extraction error of a PET (polyethylene terephthalate) resin preform which is an injection molded product, and FIG. 1 is a plan view of the apparatus of the present invention. In FIG. 1, 1 is a mold for injection molding, 2 is a take-out device for taking out a molded preform, 3 is an opening cam for opening the mold 1, and 10 is a preform.
Then, the preform 10 is molded several tens of times at a time by the disk-shaped injection mold 1, and then transferred from the mold 1 to the disk-shaped vacuum suction-type take-out device 2, and the take-out device 2 is moved. This is basically the same as the conventional one in that the injection-molded preform 10 is conveyed to the next process such as a temperature control station or a blow molding station.

In the present invention, the sensor 4a that projects and receives the laser beam 5 in a direction orthogonal to the direction in which the take-out device that has received the preform at one end of the take-out device moves to the next process, and the reflection mirror 4b that reflects the laser beam 5 are reflected. When the take-out device 2 moves to the next process, the laser beam 5 emitted from the sensor 4a scans a predetermined position on the mold surface to detect a take-out error of the preform 10. It is configured.
Note that the sensor 4a is not limited to the one that projects and receives the laser beam 5, but may be one that projects and receives infrared rays and other various beams. Of course, various optical measuring instruments may be used.

That is, in the present invention, in order to detect a mistake in taking out an injection-molded product, conventionally, a plurality of laser measuring instruments, which are installed in the same number of columns or rows, are moved in the direction in which the take-out device 2 moves to the next process. By providing the laser measuring device 4 so that the laser beam 5 crosses in a direction orthogonal to the direction of the injection, only one laser measuring device is injection-molded due to the relative positional relationship between the movement of the take-out device 2 and the mold surface. It is devised so that the total number of goods can be checked.
Further, by providing the laser measuring device 4 on the side of the take-out device 2, there is no influence of scattering of grease due to opening and closing of the mold, and no malfunction due to adhesion of grease or the like as in the prior art occurs.

  FIG. 3 is an explanatory view when the apparatus for showing the moving direction of the take-out apparatus 2 is viewed from the side. In the embodiment, as shown in FIG. 3, the movement direction of the take-out device 2 is vertical, and a pair of sensors 4a and a reflecting mirror 4b are attached to the lower end of the take-out device 2 in the horizontal direction. However, the present invention is not limited to this. For example, when the moving direction of the take-out device 2 is a horizontal direction, a pair of sensors 4a and a reflection mirror 4b may be attached to the side end of the take-out device 2 in the vertical direction. .

  In addition, since the opening cams 3 are attached to both sides of the mold 1 and the gap with the core 3 is narrow, the laser measuring instrument 4 so that the laser beam 5 is projected directly along the mold surface. It is normal not to be able to provide. Therefore, in the embodiment, the laser measuring device 4 is set perpendicularly to the mold surface, and a reflection mirror 6 for projecting and receiving light by bending the laser beam 5 at a right angle is provided at the front portion of the sensor 4a. The laser measuring device 4 can be installed in a narrow place.

In the present invention, a predetermined position on the mold surface is scanned by the laser beam 5 described above to detect a take-out error of the preform 10. More specifically, the following configuration is provided.
FIG. 1 shows the first method, in which the laser beam 5 is set to scan several millimeters ahead of the tip of the core 1a of the mold 1 and is formed at the tip of the remaining preform 10. When the laser beam 5 is shielded by the gate 11 thus formed, a defect signal is output from the sensor 4a as an error in taking out the preform 10 (see the laser beam 5 on the right side of FIG. 4).
That is, if all of the molded preforms 10 have been taken out normally, there should be nothing that blocks the laser beam 5 when the tip of the core 1a of the mold 1 is scanned, but the preform 10 remains. If the laser beam 5 is shielded by the gate trace 11, the gate trace 11 is detected as having an error in taking out the preform 10.

FIG. 2 shows a second method, in which the laser beam 5 is set so as to measure the core diameter by scanning the central portion of the core 1a of the mold 1, and the remaining preform 10 When the thickness is larger than the core diameter registered in advance, a defect signal is output from the sensor 4a as an error in taking out the preform 10 (the laser on the left side in FIG. 4). See beam 5).
That is, if all of the molded preforms 10 are normally taken out, the core diameter is (D), so this value is registered in advance. On the other hand, if the preform 10 remains, it is measured as a diameter (D + 2d) that is larger by the thickness (d) of the preform 10, so that the diameter is larger than the core diameter (D) registered in advance. If there is, it is detected that there is a mistake in taking out the preform 10.

  In this way, when a failure signal is output from the sensor 4a, a signal from the sensor 4a and a timing signal for preventing malfunction when the laser beam is shielded by a projection or the like other than the detection region are generated. The AND circuit is connected to the AND circuit, and a signal is output from the AND circuit only when a take-out error occurs, and the injection molding apparatus is stopped by this signal, and the take-out error of the preform is displayed to the operator. FIG. 5 shows a flowchart of this signal flow.

Further, in the second method, the processing of the defective signal is basically the same as that in the first method, and the signal flow in this case is shown in the flowchart of FIG.
Further, as shown in FIG. 6, in order to automatically set the set value, scanning is performed by a sensor before and after the preform 10 is transferred to the take-out device 2, and the sensor signal, the position signal of the take-out device, and the take-out device movement pulse signal Is sent to the calculation / processing unit via the AND circuit, the core diameter (D) and the preform diameter (D + 2d) are measured, and set values are set by a preset program. In addition, when setting a setting value arbitrarily, it can carry out with a manual setting device.
Also, in both cases of the first and second methods, if a general program for recognizing the position of the defective signal generation is added and incorporated, it is displayed at which position an injection molded product take-out error has occurred. It is also possible.

  As is clear from the above description, the present invention provides a sensor for projecting and receiving a laser beam in a direction orthogonal to the moving direction in which the take-out device that receives the preform at one end of the take-out device proceeds to the next process, and the laser beam. Since a laser measuring instrument comprising a reflecting mirror is provided and the take-out device moves to the next process, a predetermined position on the mold surface is scanned with a laser beam to detect a take-out error of the preform. Whether or not there is a mistake in taking out the injection molded product can be accurately detected with only one sensor, the set time is short, and further malfunction due to scattering of grease or the like can be prevented.

It is a front view which shows embodiment of this invention. It is a front view which shows embodiment of this invention. It is explanatory drawing which shows the moving direction of a taking-out apparatus. It is explanatory drawing which shows the scanning position of a laser beam. It is a flowchart which shows the flow of the signal in a 1st system. It is a flowchart which shows the flow of the signal in a 2nd system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection mold 1a Core 2 Taking-out apparatus 3 Opening cam 4 Laser measuring instrument 4a Sensor 4b Reflection mirror 5 Laser beam 6 Reflection mirror 10 Preform 11 Gate trace

Claims (6)

  An injection molding product detection error detection device in an injection molding device for detecting a preform extraction error from a mold when an injection molded preform is extracted from the mold to the extraction device, and one end of the extraction device The take-out device that receives the preform is provided with a laser measuring device comprising a sensor for projecting and receiving a laser beam and a reflecting mirror for reflecting the laser beam in a direction perpendicular to the moving direction to the next process. An injection molding product detection error detecting device characterized in that, when moving to a process, a predetermined position on the mold surface is scanned with a laser beam to detect a preform extraction error.   2. The injection molded product according to claim 1, wherein the moving direction of the take-out device is a vertical direction or a horizontal direction, and a pair of sensors and a reflecting mirror are attached in a horizontal direction or a vertical direction at a lower end portion or a side edge portion of the take-out device. Mistake detection device.   2. The injection molding product take-out detection device according to claim 1, wherein a reflection mirror for bending and projecting a laser beam at a right angle is provided at a front portion of the sensor.   The laser beam is set to scan several millimeters ahead of the core tip of the mold, and if the laser beam is shielded by the trace of the gate formed at the remaining preform tip, a preform removal error will occur. The ejection error detection device for an injection molded product according to claim 1, wherein a defect signal is output from the sensor.   The laser beam is set so as to measure the core diameter by scanning the core center part of the mold. The laser beam is thickened by the remaining preform and has a diameter larger than the pre-registered core diameter. 2. An injection molding product take-out detection apparatus according to claim 1, wherein a failure signal is output from the sensor as a preform take-out error. Connect the timing signal to prevent malfunction when the laser beam is shielded by projections etc. outside the detection area and the signal from the sensor, and output the signal from the AND circuit only when an extraction error occurs 6. The injection molding product extraction error detection device according to claim 4, wherein the injection molding device is stopped by this signal and a preform extraction error is displayed.

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