JPS6312258B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pinhole detector that detects defects such as pinholes by applying a high frequency and high voltage to an ampoule in which a chemical solution or the like is sealed.

Since pharmaceuticals are life-related, they are produced under extremely high quality control, but even though the sealed ampoules containing them may appear to have no defects at first glance, they actually have pinholes, cracks, etc. The reality is that there are a large number of defective and defective products, and unless they are completely sealed, secondary contamination due to the intrusion of bacteria and the like is unavoidable. If a contaminated drug is injected into the human body, it can lead to serious consequences.
A leak test that detects pinholes and cracks in sealed ampoules is absolutely impossible.

Conventionally, vacuum staining has been most commonly used to detect pinholes in ampoules. In this method, a sealed ampoule containing a chemical is placed in a container, the container is once evacuated, a colored liquid is poured in, and air is introduced again.If there is a pinhole in the ampoule, the colored liquid will immediately disappear. The chemical enters the ampoule and stains it, making it possible to detect defective products. Since this method relies on visual inspection, the accuracy of the test may vary depending on the ability of the inspector, the PH level of the internal liquid, and the test conditions, and it may be difficult to test colored glass ampoules or colored chemical solutions. There were some shortcomings.
In addition, pinholes smaller than 5μ to 3μ cannot be detected, so pinholes with a diameter of about 1μ through which bacteria can enter are overlooked, and chemicals produced under high quality control may be contaminated by dye liquor. There were also some drawbacks.

Conventional pinhole detection methods, including methods that use radioactive substances with a short half-life that are an improvement on the vacuum dye method mentioned above, and crystallization methods, are all batch-type visual inspections. There were problems such as it was time consuming and could not be automated.

Therefore, the present inventors have developed a pinhole detection method using high frequency and high voltage that solves the problems of conventional methods, allows continuous unattended inspection, has a high detection limit, and does not affect the internal fluid. developed in response to the demands of the pharmaceutical industry.

To briefly explain the principle of this method, as shown in Fig. 1, an ampoule 1 made of an insulating material that contains a conductive chemical solution 2 inside and is sealed is inspected at the inspection point (in the figure, the tip is placed at the tip of a branch). Electrode A with small surface area
If a ground electrode B with a large surface area is arranged on the body or the like and a high frequency, high voltage AC voltage V is applied, the electrical equivalent circuit becomes as shown in FIG. In the figure, V
is the applied voltage C ₁ is the capacitance between electrode A and the liquid content 2 C ₂ is the capacitance between the electrode B and the liquid content 2 R is the electrical resistance of the liquid content I ₁ is whether the inspected product is good or not This is the minute current that flows through the circuit when

Even if the thickness of the material of the ampoule 1 is uniform, the surface areas of the two opposing electrodes A and B are different.
The capacitance of C ₂ will be larger than that of C ₁ . Therefore,
When using a high frequency AC power supply, the impedance of C ₂ can be ignored compared to C ₁ and R.
Approximately, the equivalent circuit can be regarded as a series circuit of _C1 and R, as shown in FIG.

Therefore, if the power supply voltage V is set to a voltage such that if there is a pinhole in ampoule 1, a flash will occur in the discharge gap of _C1 , but if there is no pinhole, flash will not occur. When ampoule 1 is introduced between electrodes B, a flashover occurs when the pinhole comes to a position facing electrode A, and a discharge current I ₂ flows through the circuit. If there are no pinholes in the ampoule, no flashover will occur, so only a small current _I1 will flow based on _C1 , which functions as a capacitor. Therefore, the presence or absence of a pinhole can be determined by measuring the current flowing through the circuit.

According to this method, it is possible to detect pinholes as small as 0.5μ or less, so approximately 1~
It has now become possible to detect all pinholes within a 10μ range through which various types of bacteria can enter. or,
Since the determination is based on the current value, it is measured instantaneously, and using this information, it is also possible to automatically eliminate defective products. Furthermore, there are many advantages such as no foreign matter being mixed into the liquid content.

The apparatus conventionally used for pinhole inspection by the above-mentioned high-frequency high-voltage method is as shown in FIGS. 4 and 5. It is supported by falling into a V-shaped recess 4b provided in the holder, and is transported in the direction shown by the arrow, and pinhole detection is performed using the above-mentioned method using the inspection electrodes 5 and 6 provided along the way. The ampoules are sorted in the sorting section 7.
The non-defective products are transferred to the ejection screw 8, which assumes an upright position, and are ejected onto the ampoule holder 9 where they are arranged.

In the conventional device described above, the chain conveyor 4 that holds the ampoule 1 and transports it to the detection section cannot be made of insulators such as synthetic resin due to its strength, so it is made of stainless steel and used for pinhole detection. It was used as a ground electrode. Therefore, it is not possible to maintain a sufficient distance between the electrodes, and the chain conveyor is easily soiled and difficult to clean due to its structure and mounting method, making it difficult to maintain detection accuracy at all times. In addition, since the ampoule 1 simply rests on the recess 4b of the chain conveyor 4 under its own weight, it is unstable and has a limit to high-speed processing.Furthermore, it is necessary to arrange the inspection electrodes and the sorting section in a straight line in the horizontal direction. Because of this, the width of the device becomes wide, making it difficult to increase the number of inspection points.

This invention solves the above-mentioned problems of conventional high-frequency, high-voltage pinhole detectors, can always maintain high detection accuracy, and is suitable for high-speed automatic processing of pinholes in sealed ampoules. The purpose is to provide a detector.

Hereinafter, the present invention will be described in detail based on drawings showing embodiments thereof.

In the embodiment shown in its entirety in FIG. 6, on the casing 10 housing the power unit, from the left as viewed in the figure, a supply hopper 11 inclined forward and downward, and a supply hopper 11 horizontally provided to the right from just below the outlet thereof. A supply screw 12, followed by four wheels surrounding each other following the end thereof, a supply star wheel 13, a conveyance star wheel 14, a detection main star wheel 15, and a discharge star wheel 16, which rotate in the directions of arrows at the same circumferential speed. , discharge star wheel 16
An ejection screw 17 is disposed horizontally to the right from directly below the dispensing screw 17, and an ampoule holder 18 is disposed following the ejection screw 17.

The above screws 12, 17 and star wheels 13, 1 constituting the conveying means for the ampoule 1
4, 15, and 16 are synchronously and continuously driven by one drive motor provided in the casing 10 via a shaft 19 and a gear mechanism 20 shown in FIG.

Along the outer periphery of the main star wheel 15, a first detection section 21, a second detection section 22, a third detection section 23, and a sorting section 24 are arranged in order in the ampoule conveyance direction, and each detection section is arranged in order in the ampoule conveyance direction. It is responsible for inspecting areas where pinholes are likely to occur, ie, the bottom, branch ends, and shoulders, and has electrodes with shapes and arrangements suitable for inspection of each area. Control of the voltage applied to these three detection sections, detection of pinholes, and selection of defective products based on the detection results are performed by a detection control section 25 located at the top of the device. When any of the detection sections 21, 22, and 23 detects a pinhole, when the ampoule comes to the position of the sorting section 24, the sorting section is activated to flick the ampoule off the wheel 15 and remove it with an air jet.

Each star wheel 13, 14, 15, 16 and the conveyance screw 12 provided before and after these,
7 shows a detailed front view of the transition section between the main body 17 and FIG. 8, and FIG. Each star wheel 1
Ampoule time-keeping recesses 26 are provided at the same intervals on the outer peripheries of 3, 14, 15, and 16. The detection main star wheel 15, which holds the ampoule 1 and transports it to the detection section for pinhole detection, is made of electrically insulating material such as synthetic resin, and has a main star wheel 15 on its outer periphery, as shown in FIG. A groove 27 is provided, and flanges 28 and 29 on both sides thereof are provided with recesses 26a and 26b having semicircular cross sections suitable for holding the shoulder and waist portions of the ampoule 1. The depth of the groove is set so that the bottom surface of the groove 27 does not come into contact with the ampoule when the ampoule 1 is held in this recess. Holes 30 and 31 are drilled from the innermost parts of the recesses 26a and 26b toward the center of the wheel 15, and these two holes communicate with a hole 32 that is drilled from the rear surface of the wheel 15 parallel to the axis. . Therefore, the same number of holes 32 as the number of ampoule holding recesses 26 provided around the rear surface of the wheel 15 are opened on one circumference at equal intervals.

An arcuate groove 35 is provided on the front surface of the bearing member 34 that pivotally supports the shaft 33 of the star wheel 15 at a position facing the opening of the hole 32, and there is no sliding contact between the circumference of the groove 35 and the rear surface of the star wheel. They are in movable and airtight contact. Further, the groove 35 is connected to the air suction hose 36 and the intake pipe 37 (shown in FIG. 8).
It is connected to a vacuum pump provided within the casing 10. The range in which the arcuate groove 35 is provided is as follows:
The area corresponds to the point between the point at which the star wheel 15 receives the ampoule from the conveying star wheel 14 (point D in FIG. 7) and the point at which the ampoule is transferred to the discharge star wheel 16 (point E in FIG. 7). In the range where the hole 32 opens into the groove 35, the hole 30,
The inside of the ampoule 31 becomes negative pressure, and the ampoule 1 is sucked and held securely and stably in the recesses 26a and 26b.
When the position of the opening of the hole 32 moves out of the range of the groove 35, the suction force on the ampoule is released.

The three star wheels 13, 14, 16 other than the main star wheel 15 do not necessarily need to be made of an insulator, and there is no need to attract the ampoule 1 held in the recess 26. In this embodiment, the guide plate 3 is
The ampoule 1 supplied to the supply star wheel 13 via the feeder 8 is held in the recess 26 by its own weight and is passed to the next conveying star wheel 14. In the conveyance star wheel 14 and the discharge star wheel 16, the conveyance range of the ampoule 1 is a downwardly facing part of the circumference, so guardrails 39,
40 are provided. Also, the ejection screw 17
Similar to the conventional device, the guide 41 provided along the ampoule holder 18 gradually changes its inclination midway to eject the ampoule in an upright position onto the ampoule holder 18.

Since this device is constructed as described above, the ampoules 1 that stand upright against the inclined surface of the supply hopper 11 and descend toward the outlet while being pushed by their own weight are transported by the supply screw 12. They are guided by the guide plate 38 and fall one by one into the recess 26 on the outer periphery of the supply star wheel 13, and are transported while being held by their own weight to the point of contact with the adjacent transport star wheel 14, where they rotate synchronously. The main star wheel 14 is supported by a guard rail 39 to prevent it from falling out of the recess 26, and is transported to a contact point D with the main star wheel 15. Ampoule 1 is the star wheel 15 that has been rotating synchronously at this point.
are passed through the recesses 26, 26a, 26b. In this respect, the holes provided between the bottoms of the recesses 26a and 26b and the rear surface of the wheel correspond to the grooves 35 on the front surface of the bearing member 34.
As the ampoule 1 begins to communicate with the discharge star wheel 16, the ampoule 1 is attracted to the recesses 26a and 26b by negative pressure, is held stably and reliably, and is conveyed to the contact point E with the discharge star wheel 16. During this time, the ampoule 1 passes between both electrodes provided on each of the first detection section 21, the second detection section 22, and the third detection section 23 arranged along the outer periphery of the main star wheel 15, If a pinhole is detected in any of the detection sections that apply a high-frequency, high-voltage AC voltage and sequentially inspect the bottom, branch tip, and shoulder for the presence of pinholes,
When the ampoule passes through the sorting section 24, the sorting section is actuated by a signal from the detection control section 25, and the ampoule is removed from the recess of the wheel using an air jet. For non-defective products, discharge star wheel 1 at point E.
At this point, the suction hole 32 communicating with the recess holding the ampoule 1 is removed from the groove 35, so the suction force on the ampoule 1 is released, and the ampoule is conveyed along the guard plate 40 to the ejection screw 17. After being transferred and converted into an upright position by the guide 41, the ampoules are discharged onto the ampoule holder 18 and are pushed together to move forward and line up.

Now, since the above-mentioned detection of defects such as pinholes and removal of defective products are done instantaneously, the main star wheel 15 can be rotated continuously at a constant speed, so the drive control of the conveying device is extremely difficult. This makes it easier, and there is no acceleration caused by starting or stopping the wheels. In addition, the ampoule is formed in a recess 26 provided on the outer periphery of the main star wheel 15.
Coupled with the fact that it is reliably adsorbed by negative pressure on a and 26b, it becomes possible to transport at a higher speed than with conventional devices. In addition, since the suction force for the ampoule is reliably activated and released at the contact point with the adjacent conveyor wheels 14 and 16, the ampoule can be transferred easily and reliably.

By using a rotating disk as the means for holding the ampoule and transporting it to the detection section, the width of the device is smaller than when the detection section and the sorting section are arranged horizontally in a straight line, and the width of the device can be adjusted as needed. It also becomes easy to increase the number of detection units.

Furthermore, since the main star wheel 15 is made of an electrical insulator such as synthetic resin, the ampoule conveying and holding member can be used as a ground electrode for pinhole inspection, as in a conventional chain conveyor-based device. This eliminates the need for this, allows for sufficient distance between the electrodes, and makes it easier to remove, install, and clean the electrodes, which improves detection accuracy and makes it possible to maintain high accuracy at all times. .

Furthermore, the outer periphery of the main star wheel 15 is provided with a groove 27 having a depth that prevents the bottom surface from coming into contact with the ampoule suctioned and held in the recess, so that the recess of the wheel This prevents electrical conduction between the two electrodes due to dirt on the edge surface of the sensor, thereby preventing a decrease in detection accuracy.

In high-frequency, high-voltage method pinhole inspection, when a flashover occurs, ozone, which is harmful to the human body, is generated, but due to the negative pressure that attracts the ampoule, this ozone is released from the gap between the ampoule and the recess. Hole 3
0 and can be expelled outdoors via a vacuum pump.

As described above, according to the present invention, ampoule pinhole inspection can be performed automatically with higher precision than before, while maintaining that precision at all times, and the processing speed is significantly improved. It is also possible to directly incorporate it into the system, resulting in remarkable effects on mass production, automation, quality control, etc. of sealed ampoules.

[Brief explanation of the drawing]

Figures 1 to 3 are circuit diagrams explaining the principle of the high-frequency, high-pressure pinhole detection method, Figure 4 is a front view showing an example of a typical conventional ampoule pinhole detector using the above detection method, and Figure 5. The figure is a front view showing a part of the chain conveyor that makes up the conveyance device.
Fig. 6 is an overall front view of an embodiment of the present invention, Fig. 7 is an enlarged front view of the ampoule holding and conveying device, Fig. 8 is a side view thereof, and Fig. 9 is an essential part of the main star wheel. FIG. 3 is a schematic diagram showing an enlarged cross-section of a portion. 1... Ampoule, 15... Rotating disk (main star wheel), 21, 22, 23... Detection section,
26... Ampoule holding recess, 27... Groove, 36
...Air suction hose.

Claims (1)

[Claims] 1. In a pinhole detector that detects defects such as pinholes by applying high-frequency, high-voltage voltage to an ampoule in which a chemical solution or the like is sealed, as a means for holding the ampoule and transporting it to a detection unit. 1. A pinhole detector, comprising a rotating body having a concave portion on its outer circumferential surface that attracts an ampoule by negative pressure, and at least a peripheral portion of the rotating body made of an electrical insulator such as a synthetic resin. 2. A groove is provided all around the outer circumferential surface of the rotary disk that holds and conveys the ampoule, and the bottom surface of the groove does not come into contact with the ampoule when the ampoule is suctioned and held in the recess provided on the outer periphery. The pinhole detector according to claim 1, characterized in that the pinhole detector has a depth.