JP2006343241A - Leak inspection device of plastic bottle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leak inspection device of a plastic bottle capable of removing an operation failure caused by grease which is a defect of a solenoid valve, while using the solenoid valve capable of high-speed response, and supplying a highly-clean compressed air into the plastic bottle. <P>SOLUTION: This leak inspection device of the plastic bottle is equipped with a main rotor 10 for supporting a plurality of plastic bottles and conveying them on a prescribed circumference; and a pressure head 35 having a seal member 31 installed on the main rotor 10 and sealing a mouth part 1m by being engaged with the mouth part 1m of the plastic bottle 1, for supplying gas into the plastic bottle 1. In the device, the pressure head 35 is connected to a manifold 40 equipped with a filter 41 inside through an air-operated valve 50 to be opened/closed by the pressure of the compressed air, and the manifold 40 is connected to a compressed air source 44 through a communicating path 12a, and the air-operated valve 50 is connected to the communicating path 12a through the solenoid valve 51. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a PET bottle leak inspection apparatus, and more particularly to an apparatus for detecting whether a PET bottle has a defect such as a pinhole before filling the PET bottle with a liquid such as a beverage. The present invention relates to a PET bottle leak inspection apparatus that detects whether compressed air leaks from a PET bottle by filling with compressed air.

  Conventionally, PET bottles (PET bottles), which are lightweight plastic bottles, are frequently used for filling soft drinks and the like. Before filling a PET bottle with a liquid such as a beverage, it is necessary to inspect the PET bottle for defects such as pinholes. Conventionally, a PET bottle leak inspection apparatus has been used. In this PET bottle leak inspection device, the PET bottle is transferred by a star wheel and supplied to the main rotor, the PET bottle is placed on the container table of the main rotor, and the pressure head is lowered to open the PET bottle mouth. The mouth of the PET bottle is sealed with the packing of the pressure head, and in this state, compressed air is supplied from the compressed air source into the PET bottle via the pressure head. Then, after supplying a predetermined amount of compressed air into the PET bottle, the inside of the PET bottle is sealed, and the PET bottle is transported by the main rotor while the PET bottle is transported by the pressure sensor connected to the pressure head after a predetermined time has passed. The pressure is measured and leaks from the plastic bottle are detected.

  Conventionally, as a switching device for a piping system that sends compressed air into a PET bottle, a spool type solenoid valve has been used mainly for high-speed response in order to keep the initial pressure value constant. In this case, since the grease used for the sliding portion in the electromagnetic valve may be mixed with the compressed air and introduced into the PET bottle even in a small amount, the grease for food suitable for food hygiene has been used.

However, it has been found that when food-grade grease is used for the spool type solenoid valve described above, the grease may cause malfunction of the solenoid valve.
In addition, the spool type solenoid valve cannot prevent slight dust generation from the sliding part, no matter what kind of grease is used. There is a problem that it cannot respond to the request to introduce.

  Furthermore, in the conventional leak inspection apparatus, since only a filter (micro mist separator) is provided in the air intake (upstream) portion, the original pressure solenoid valve through which air passes, a rotary joint, and a hole penetrating the shaft Various devices such as air distribution manifolds and switching solenoid valves can be sources of air contamination.

  The present invention has been made in view of the above-mentioned circumstances, and while using a solenoid valve capable of high-speed response, it eliminates malfunction caused by grease, which is a drawback of this solenoid valve, and is highly compressed. It is an object of the present invention to provide a PET bottle leak inspection apparatus capable of supplying air into a PET bottle.

  In order to achieve the above object, a PET bottle leak inspection apparatus according to the present invention supports a plurality of PET bottles and conveys them on a predetermined circumference, and is installed in the main rotor at the mouth of the PET bottle. In a PET bottle leak inspection apparatus having a sealing member that engages and seals the mouth portion, and that includes a pressurizing head that supplies gas into the PET bottle, the pressurizing head is opened and closed by the pressure of compressed air Connected to a manifold having a filter inside through an air operated valve, connected the manifold to a compressed air source through a communication path, and connected the air operated valve and the communication path through a solenoid valve. It is characterized by.

  According to the present invention, by opening the electromagnetic valve, compressed air is supplied from the compressed air source to the air operated valve, and the air operated valve is opened. As a result, compressed air is supplied from the compressed air source to the manifold, the compressed air passes through the filter in the manifold to be purified, and the clean compressed air is supplied into the PET bottle through the open air operated valve. . Therefore, the inside of the PET bottle is filled with compressed air having a predetermined pressure. If the pressure in the PET bottle after the lapse of the predetermined time is the same as the initial pressure, it is determined that there is no leak from the PET bottle and there is no defect such as a pinhole in the PET bottle.

According to one aspect of the present invention, the electromagnetic valve is a spool type electromagnetic valve.
According to one aspect of the invention, the filter comprises a HEPA filter.
According to the present invention, by using a HEPA filter as a filter, compressed air with high cleanliness can be supplied to a PET bottle.
According to one aspect of the present invention, the air operated valve is a diaphragm valve that opens and closes the diaphragm with compressed air.

The present invention has the following effects.
1) Since there is no need to use food grease for the solenoid valve, there is no malfunction of the solenoid valve caused by food grease.
2) Compressed air can be supplied to the PET bottle without going through a solenoid valve with a sliding part, so there is no risk of dust from the sliding part entering the PET bottle, and cleaner air is supplied into the PET bottle. Can be introduced.
3) Since air is cleaned immediately after injection into the PET bottle, the cleaned air can be supplied into the PET bottle with a high degree of cleanness without passing through various devices.

Hereinafter, an embodiment of a PET bottle leak inspection apparatus according to the present invention will be described with reference to FIGS.
FIG. 1 is a plan view showing the overall configuration of a PET bottle leak inspection apparatus. As shown in FIG. 1, the PET bottle leak inspection apparatus includes an inlet star wheel 2 that carries a PET bottle 1 to be inspected into a main rotor 10, and an outlet star wheel that carries the PET bottle 1 after inspection out of the main rotor 10. 3 is provided. On the upstream side of the inlet star wheel 2, guide rails 5 and 5 for carrying the plastic bottle 1 into the inlet star wheel 2 are installed. Further, guide rails 6 and 6 for carrying out the plastic bottle 1 from the outlet star wheel 3 are installed on the downstream side of the outlet star wheel 3. The inlet side guide rails 5 and 5 and the outlet side guide rails 6 and 6 are downwardly inclined in the traveling direction. Star wheel guides 7, 8, 9 are provided on the outer peripheral side of the inlet star wheel 2, the outer peripheral side of the main rotor 10, and the outer peripheral side of the outlet star wheel 3, respectively.

  FIG. 2 is a diagram showing a detailed structure of the main rotor, and is a cross-sectional view of the main rotor. As shown in FIG. 2, the main rotor 10 is rotationally driven by a driving source (not shown) and is integrally connected to the upper and lower rotary shafts 12 by a coupling 11, and is fixed to the rotary shaft 12 and integrated with the rotary shaft 12. A rotating base plate 13, a support plate 14 fixed to the upper end of the rotating shaft 12 and rotating integrally with the rotating shaft 12, and a plurality of plates that move up and down and engage with the mouth 1m of the PET bottle 1 during a leak inspection The pressure head 35 is provided. The lower portion of the rotary shaft 12 is supported by a support frame 19 via a bearing housing 18 in which a bearing 17A is provided, and the rotary shaft 20 is disposed coaxially with the rotary shaft 12 above the rotary shaft 12. The rotary shaft 20 is supported in a hollow shaft 21, and the hollow shaft 21 is inserted into a bearing housing 22 that holds the bearing 17 </ b> B and is fixed to the support plate 14. A through hole 20 a is formed in the rotary shaft 20, and a power cable 100 connected to an external power source is passed through the through hole 20 a to supply power to the spool type electromagnetic valve 51 and the pressure sensor 45.

  The main rotor 10 includes a neck ring star wheel 25 that supports the neck ring 1a of the plastic bottle 1 and a shoulder pressing star wheel 26 that supports the shoulder of the plastic bottle 1, and the neck ring star wheel 25 and the shoulder pressing star wheel. 26 is fixed to the base plate 13 via a support 27. A plurality of arc-shaped pockets 26 a that engage with the neck ring 1 a of the plastic bottle 1 and support the neck ring 1 a are formed on the outer peripheral portion of the neck ring star wheel 25 (see FIG. 1). A plurality of arc-shaped pockets (not shown) that engage with the shoulder portion of the plastic bottle 1 are formed on the outer peripheral portion of the shoulder pressing star wheel 26. Further, on the outer peripheral side of the neck ring star wheel 25, the star wheel guide 8 is provided for preventing the plastic bottle 1 from jumping out and positioning the plastic bottle. The star wheel guide 8 may be replaced with a belt supported by a pulley and rotatable. The neck ring star wheel 25, the inlet star wheel 2 and the outlet star wheel 3 are arranged in the same plane.

  A plurality of guide bars 28 are erected on the support plate 14, and these guide bars 28 are arranged at predetermined intervals on a predetermined circumference. A slide member 30 having a cam follower 29 is attached to each guide bar 28 so as to be movable up and down. A pressure head 35 is fixed to each slide member 30, and the pressure head 35 and the slide member 30 move up and down integrally.

  On the other hand, a fixed plate 32 is fixed to the hollow shaft 21 provided on the outer peripheral side of the rotary shaft 20, and a cylindrical body 34 is fixed to the fixed plate 32 via a support 33. The upper end surface of the cylindrical body 34 constitutes a cam surface 34 a, and the cam surface 34 a is formed with a height difference over the entire circumference of the upper end surface of the cylindrical body 34. When the support plate 14 rotates with the rotation of the main rotor 10, the cam follower 29 of each slide member 30 moves up and down following the cam surface 34a, whereby the slide member 30 and the pressure head 35 are moved to the guide bar. It moves up and down along 28.

  FIG. 3 is a schematic view showing a piping system for supplying compressed air to the pressure head 35. As shown in FIG. 3, an air operated valve 50 is fixed to the pressure head 35. The pressure head 35 and the air operated valve 50 are supported by a support rod 36 fixed to the slide member 30. The pressure head 35 includes a packing 31 that is attached to the lower end surface of the pressure head 35 to form a seal member, and a substantially hemispherical nozzle 38 that protrudes downward from the pressure head 35.

  The nozzle 38 communicates with the manifold 40 via a communication passage 35 a (shown in FIG. 5) in the pressure head 35, an air operated valve 50, and a pipe 39. The manifold 40 is fixed to the support plate 14 as shown in FIG. A HEPA filter 41 is accommodated in the manifold 40, and the compressed air supplied into the PET bottle 1 is cleaned by the HEPA filter 41.

The manifold 40 is communicated with the communication passage 12 a of the rotary shaft 12 through a pressure reducing valve 47 and a pipe 42. The communication path 12 a of the rotating shaft 12 is communicated with a compressed air source 44 through a rotary joint 43. A source pressure electromagnetic valve or the like is disposed between the compressed air source 44 and the rotary joint 43, but these are omitted in FIG.
On the other hand, the communication path 12a of the rotary shaft 12 is communicated with a spool type solenoid valve 51 via a pipe 49 and a solenoid valve manifold 40b, and the spool type solenoid valve 51 is connected to the air operated valve 50 via a pipe 52. ing. The spool-type solenoid valve 51 is supplied with compressed air having a high pressure of 294 to 392 kPa (3 to 4 kgf / cm ² ) to ensure high-speed operation, and the HEPA filter 41 has a pressure of 196 kPa reduced by the pressure reducing valve 47. (About 2 kgf / cm ² ) is supplied.

  As shown in FIG. 2, the communication path 35 a (shown in FIG. 5) in the pressure head 35 is connected to the pressure sensor 45 via the sensor tube 48. The pressure sensors 45 are installed corresponding to the pressure heads 35, and in the present embodiment, 36 pressure sensors 45 are installed.

FIG. 4 is a diagram showing a detailed structure of the air operated valve.
As shown in FIG. 4, in the air operated valve 50, a diaphragm 52 and a piston 53 are accommodated in a valve main body 54, and the spool type solenoid valve 51 is opened and compressed air is sent from the spool type solenoid valve 51 to the air operated valve 50. Is supplied to the piston 53, the diaphragm 52 is opened and closed. When the diaphragm 52 is opened, compressed air is supplied from the manifold 40 to the air operated valve 50 through the pipe 39, and compressed air is supplied from the air operated valve 50 to the pressurizing head 35. That is, the air operated valve 50 operates the piston 53 by the action of compressed air to open and close the diaphragm 52, and is a kind of diaphragm type valve.

Next, the operation of the PET bottle leak inspection apparatus configured as described above will be described.
FIG. 5 is a schematic diagram showing the operation of the pressure head 35. As shown in FIG. 1, the plastic bottle 1 is supplied to the inlet star wheel 2 from the inlet side guide rails 5, 5. The plastic bottle 1 transferred by the inlet star wheel 2 is delivered to the main rotor 10. At this time, the neck bottle 1 a is supported by the neck ring star wheel 25 of the main rotor 10 and the shoulder portion of the plastic bottle 1 is supported by the shoulder pressing star wheel 26. FIG. 5A is a schematic diagram showing this state. In the state shown in FIG. 5A, as the main rotor 10 rotates, the plastic bottle 1 starts to be transported along the pitch circle of the main rotor 10.

  When the PET bottle 1 is transferred to the main rotor 10, the pressure head 35 is lowered by the action of the cam follower 29, and the pressure head 35 comes into contact with the mouth 1 m of the PET bottle 1. At this time, as shown in FIG. 5 (b), since the packing 31 is provided on the lower end surface of the pressure head 35, the packing 31 is in close contact with the top surface of the mouth portion 1 m of the PET bottle 1. In order to ensure the sealing between the packing 31 and the top surface of the mouth portion 1m of the plastic bottle 1, the pressure head 35 presses the packing 31 against the mouth portion 1m of the plastic bottle 1 with a predetermined load. This load is received by the neck ring star wheel 25 that supports the neck ring 1a of the plastic bottle 1. The neck ring 1a and the mouth 1m in the plastic bottle 1 are made thicker and stronger than the body for the purpose of attaching a cap or the like. Therefore, even if the pressure head 35 applies a relatively high load to the mouth 1m and the neck ring 1a of the PET bottle 1 in order to sufficiently work the sealing function of the packing 31, the PET mouth 1m and the neck ring 1a. Will not deform.

Thus, when the seal between the packing 31 provided on the lower end surface of the pressure head 35 and the opening 1m of the plastic bottle 1 is completed, the communication path 12a of the rotary joint 43 and the rotary shaft 12 from the compressed air source 44 is completed. Then, compressed air is supplied to the spool type solenoid valve 51 through the pipe 49 and the solenoid valve manifold 40b, and the spool type solenoid valve 51 is opened. When the spool type solenoid valve 51 is opened, compressed air is supplied from the spool type solenoid valve 51 to the air operated valve 50 through the pipe 52, the air operated valve 50 is opened, and the compressed air is supplied from the manifold 40 to the pipe 39 and the pressure head. It is supplied to the nozzle 38 via the communication path 35 a in the cylinder 35. At this time, since the compressed air supplied from the manifold 40 to the nozzle 38 is cleaned by the HEPA filter 41, the compressed air has a high cleanliness. In this way, a predetermined amount of clean compressed air is supplied from the nozzle 38 into the PET bottle 1 and the PET bottle 1 is filled with clean compressed air having a predetermined pressure of 196 kPa (about 2 kgf / cm ² ).

  In this state, the PET bottle 1 is conveyed along the pitch circle of the main rotor 10, and after a predetermined time during the conveyance, the pressure in the PET bottle 1 is increased by the pressure sensor 45 as shown in FIG. Measured. If the pressure in the PET bottle after the lapse of the predetermined time is the same as the initial pressure, it is determined that there is no leak from the PET bottle and there is no defect such as a pinhole in the PET bottle 1.

  After completion of the leak inspection, the PET bottle 1 is transferred from the main rotor 10 to the outlet star wheel 3, and the normal PET bottle 1 is transferred by the outlet star wheel 3 and transferred to the next process through the outlet side guide rails 6 and 6. Is done. On the other hand, the PET bottle 1 determined to be defective is unsupported by the outlet star wheel 3 at the position of the defective product discharge chute 46, and the PET bottle 1 is discharged to the defective product discharge chute 46.

It is a top view which shows the whole structure of the PET bottle leak inspection apparatus which concerns on this invention. It is a figure which shows the detailed structure of the main rotor which concerns on this invention, and is sectional drawing of a main rotor. It is the schematic which shows the piping system for supplying compressed air to the pressurization head which concerns on this invention. It is a figure which shows the detailed structure of the air operated valve which concerns on this invention. It is a schematic diagram which shows operation | movement of the pressurization head which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plastic bottle 1a Neck ring 1m Mouth part 2 Inlet star wheel 3 Outlet star wheel 5,6 Guide rail 7, 8, 9 Star wheel guide 10 Main rotor 11 Coupling 12, 20 Rotating shaft 12a, 35a Communication path 13 Base plate 14 Support plate 17A, 17B Bearing 18, 22 Bearing housing 19 Support frame 20a Through hole 21 Hollow shaft 25 Neck ring star wheel 26 Shoulder pressing star wheel 26a Pocket 27, 33 Support 28 Guide bar 29 Cam follower 30 Slide member 31 Packing 32 Fixed plate 34 Cylinder Body 34a Cam surface 35 Pressure head 36 Support rod 38 Nozzle 39, 42, 49, 52 Piping 40 Manifold 40b Manifold for solenoid valve 41 HEPA filter 4 Rotary joint 44 defective compressed air source 45 pressure sensor 46 discharge chute 47 tube pressure reducing valve 48 sensor 50 air operate valve 51 spool type solenoid valve 52 diaphragm 53 piston 54 valve body 100 power cable

Claims (4)

A main rotor that supports a plurality of plastic bottles and conveys them on a predetermined circumference, a seal member that is installed in the main rotor and that engages with a mouth part of the plastic bottle to seal the mouth part, and gas is sent to the plastic bottle In a PET bottle leak inspection apparatus equipped with a pressure head to be supplied inside,
The pressurizing head is connected to a manifold having a filter inside through an air operated valve that opens and closes by the pressure of compressed air, the manifold is connected to a compressed air source through a communication path, and the air operated valve and the A PET bottle leak inspection apparatus, wherein the communication path is connected via an electromagnetic valve.   2. The PET bottle leak inspection apparatus according to claim 1, wherein the electromagnetic valve is a spool type electromagnetic valve.   3. The PET bottle leak inspection apparatus according to claim 1, wherein the filter comprises a HEPA filter.   4. The PET bottle leak inspection apparatus according to claim 1, wherein the air operated valve is a diaphragm valve that opens and closes a diaphragm with compressed air. 5.

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