JP2000149961A - Product inspection device and product inspection method - Google Patents

Abstract

(57) [Summary] [Configuration] Cavity 6 of detection head 2 coated with Teflon
To guide the lithium battery 01 through the tapered portion 4,
It is positioned by the packing 7. The air near the lid of the lithium battery 01 is guided to the gas sensor 10 by the suction pump 28,
Detect electrolyte leakage. Next, the lithium battery 01 is taken out, the gas adsorbed on the sensor accommodating section 8 and the like is desorbed by the heater 12, and purge air is supplied from the solenoid valve 26,
Replace air. [Effect] A small amount of leaks can be reliably detected, and a large number of lithium batteries can be continuously inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection for checking for leakage of electrolyte from a battery, an inspection for dirt inside a collected beer bottle, etc., and an inspection for leaking from a container enclosing a retort food or an organic solvent. Etc.

[0002]

2. Description of the Related Art Applicants have proposed that a gas sensor be used to check for leakage of electrolyte from a lithium battery, a lithium ion battery or the like (Japanese Patent Application Laid-Open No. 9-259898).
issue). The inventor has subsequently studied a technique for rapidly and reliably detecting a large number of products such as lithium batteries continuously and with high sensitivity, and has arrived at the present invention.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to inspect a large number of products one by one quickly and reliably with high sensitivity. A secondary object of the present invention is to reliably guide a product into a detection head.
7) and to prevent noise from being applied to the gas sensor when the product is taken in and out (claims 4 and 5).

[0004]

According to the present invention, there is provided a product inspection apparatus for detecting a gas by bringing a gas sensor close to a product to be inspected, and a cavity for accommodating at least a part of the product and a communication with the cavity. A sensor housing is provided on the detection head, a gas sensor is housed in the sensor housing, and a purge gas supply unit for supplying a purge gas to the sensor housing is provided. Here, any gas sensor such as a metal oxide semiconductor gas sensor and a quartz oscillator gas sensor can be used as the gas sensor.

[0005] Preferably, a tapered portion or a convex curved surface communicating with the cavity and having a small diameter on the cavity side and a large diameter on the surface side of the detection head is preferably provided on the entrance side of the cavity. Particularly preferably, a packing is provided in a deep portion of the cavity in addition to the tapered portion and the convex curved surface. Preferably, a flow path is provided in the cavity for releasing an air flow accompanying the product in and out of the cavity. This flow path is constituted by, for example, a hole communicating from the cavity to the outside of the detection head, or a space provided with irregularities along the wall surface of the cavity so that the product does not enter.

Preferably, a heater is provided between the cavity and the gas sensor at a position in the sensor housing. Preferably, the detection head is made of metal or odorless hard resin, and a gas non-adsorptive and electrically insulating coating, such as synthetic resin or glass, is applied to the surface of the cavity or the sensor housing.
This is to prevent a delay in recovery of the sensor output due to remaining gas brought in from a product or the like, and to prevent a short circuit between electrodes when testing a battery or the like. Preferably, a means is provided for supplying heat to the sensor housing when the product is inserted into the cavity. This means, for example, also serves as the above-mentioned heater and generates heat when the product is inserted into the cavity, thereby preventing the heat balance of the gas sensor from being lost due to the air flow. Further, for example, the purge gas may be supplied in a heated state when the product is inserted.

According to the present invention, at least a part of a product to be inspected is inserted into a cavity provided in a detection head, a gas sensor in a sensor accommodating portion communicating with the cavity inspects gas from the product, and the product is inspected. There is provided a method of inspecting a product, wherein the steps of taking out from the cavity and purging the sensor housing portion are repeated.

Preferably, a tapered portion or a convex curved surface having a large diameter on the surface side of the detection head and a small diameter on the cavity side is provided in the detection head in communication with the cavity, and the product is guided by the tapered portion or the convex curved surface. Is inserted into the cavity, and the product is positioned in the front / rear direction of the cavity by the packing provided at the back of the cavity.

[0009]

According to the present invention, at least a part of the product is inserted into the cavity of the detection head, and the gas from the product is detected by the gas sensor in the sensor housing communicating with the cavity. For this reason, a trace amount of gas near the surface of the product can be detected, and even a trace amount of leak or a trace amount of dirt can be reliably detected. When the detection is completed, the product is taken out of the cavity, purge gas is supplied to the sensor housing, and residual gas is purged.
The recovery of the sensor output is accelerated so that the next product can be inspected in a short time. By repeating the above cycle, a large number of products can be inspected continuously and promptly, and even a very small amount of leaks can be reliably detected. The diameter of the sensor housing is preferably smaller than that of the cavity, and any gas sensor such as a quartz oscillator gas sensor or a solid electrolyte gas sensor can be used as the gas sensor in addition to the metal oxide semiconductor gas sensor.

At the entrance of the cavity, a tapered portion or a convex surface having a small diameter on the cavity side and a large diameter on the surface side of the detection head is provided so as to communicate with the cavity, and the product is guided by the tapered portion or the convex surface. Then, the product can be easily guided to a predetermined position in the cavity.

As shown in the embodiment, when trying to detect a small amount of leak or the like, an air current when inserting a product into a cavity or an air flow when removing a product from a cavity appears as noise to a gas sensor. Therefore, if a channel is provided in the cavity to allow the air flow accompanying the product in and out of the cavity, the air flow associated with the product in and out of the sensor housing is suppressed, noise to the gas sensor is reduced, and more reliable Can be inspected.
Further, when the product is inserted into the cavity, the heat balance of the gas sensor may be lost due to a difference between the surface temperature of the gas sensor and the temperature of the air flowing with the product. This results in noise on the sensor output. Therefore, if a means for supplying heat to the sensor accommodating section is provided at the time of inserting the product, the heat balance of the gas sensor can be maintained.

In the inspection method of the present invention, the product is inserted into the cavity of the detection head, and the gas attached to the product or the gas generated from the product is inspected by the gas sensor in the sensor housing communicating with the cavity. It is removed from the cavity and the sensor housing is purged to prepare for the next inspection. Therefore, a large number of products can be inspected continuously and accurately one by one. In addition, since gas adhering near the surface of the product or gas generated from the product is inspected by the gas sensor, an extremely small amount of leak, a very small amount of dirt, and the like can be easily inspected.

If a tapered portion or a convex curved surface communicating with the cavity is provided, the product can be easily inserted into the cavity by guiding the product, and the product can be positioned by bringing the product into contact with the packing provided at the back of the cavity. Alternatively, it can be stopped when the product has been inserted to a predetermined position. In addition, the part to be inspected of the product can be hermetically sealed from other parts by the packing, and a small amount of leak or the like can be inspected more accurately.

[0014]

1 to 7 show an embodiment and a modification thereof.
FIG. 1 shows a first embodiment. Reference numeral 2 denotes a detection head, which is used to check for leakage of electrolyte from a lithium battery 01, particularly a lithium ion battery. In addition, in addition to batteries such as lithium batteries 01 such as lithium ion batteries, nickel hydride batteries, nickel cadmium batteries, and dry batteries, beer bottles and juice bottles after collection and washing, packaged retort foods, and liquids were sealed. There are bottles. In the case of a juice bottle, a glass bottle, or the like, whether or not dirt or the like remains inside the bottle is inspected from a small amount of gas (odor) contained in the air inside the bottle, and whether or not the bottle is completely washed is inspected. In the case of retort foods and the like, the package is inspected for completeness and no leakage, and whether or not dirt is attached at the time of filling. In the case of such a product, the location where the leak occurs is substantially determined, and it is sufficient to inspect this location.

Reference numeral 4 denotes a tapered portion, which may be a curved surface having a convex surface. The lower surface of the detection head 2 has a large diameter, and the upper portion has a small diameter. The tip of the battery 01 is housed. Reference numeral 7 denotes a packing such as an O-ring, which positions the tip of the battery 01 and keeps the vicinity of the tip lid airtight from other portions of the cavity 6.

Reference numeral 8 denotes a sensor accommodating portion, which has a small diameter with respect to the cavity 6 so that the lithium battery 01 does not enter therein, and a base 14 to which a gas sensor 10 and a heater 12 are attached is disposed in a deep portion thereof. Although the gas sensor 10 used here is a SnO 2 -based metal oxide semiconductor gas sensor, the type is arbitrary. Although the heater 12 uses a nichrome wire coil here, any heater such as a PTC heater or a Kanthal wire heater can be used. Further, the base 14 has a number of holes (not shown), through which air flows.

The detection head 2 is made of metal so that the lithium battery 01 is not easily damaged even if it is mechanically inserted.
The metal surface easily adsorbs gas and is generally conductive. Therefore, in the embodiment, a Teflon coating 18 is applied on the metal base 16 of the detection head 2 on the surface of the tapered portion 4, the cavity 6, and the sensor housing portion 8 so as to provide surface insulation and prevent gas from adsorbing. Instead of the Teflon coating 18, a polyethylene coating, a polypropylene coating, a glass coating or the like may be used, but a fluororesin coating such as a Teflon coating is preferably used.

Reference numeral 20 denotes a suction path, 22 denotes a purge path, each of which communicates with the sensor accommodating portion 8, 24 and 26 are a pair of solenoid valves, and 28 is a cavity 6 via the suction path 20 and the solenoid valve 24. And a suction pump for sucking the air in the sensor housing 8. A clean air cylinder (not shown) or the like is connected to the upstream side of the electromagnetic valve 26 so that clean air or the like for purging can be supplied from the purge passage 22. The suction path 20 needs to be provided on the opposite side of the cavity 6 when viewed from the gas sensor 10, and the arrangement of the purge path 22 is optional. For example, the purge path 22 may be provided by branching the suction path 20. . Alternatively, the purge passage 22 may be communicated with the cavity 6, the tapered portion 4, or the like, from which purge air is supplied, and the purge air is suctioned by the suction pump 28. That is, the purge passage 22 may be disposed so that the purge air flows between the sensor housing 8 and the cavity 6. Here, taking into account the convenience of the piping, the suction passage 20 and the purge passage 22 are provided above the detection head 2 so that these piping do not interfere with other portions.

Reference numeral 30 denotes a battery transport unit which transports a large number of lithium batteries 01 one by one from left to right in FIG. 1, for example. So that the tip can be inserted into the cavity 6 until it stops. Also, the battery 01 for which the inspection has been completed is a signal from the detection unit 34,
0 is sorted into a non-defective product and a defective product and conveyed.

Reference numeral 32 denotes a timing control unit, and reference numeral 34 denotes a detection unit, which compares a signal from the gas sensor 10 with a predetermined detection condition to check for a leak. 36 is a setting section for setting detection conditions, 38 is a heater control section for controlling the heater 12 for degassing the cavity 6 and the sensor housing section 8 and the like, and 40 is a display section for displaying inspection results and the like. It is.

FIG. 2 shows a test timing of the lithium battery 01 in the embodiment. The inspection is performed, for example, at intervals of 10 to 20 seconds and the like, and the batteries 01 are successively performed one by one. FIG. 2 shows an operation for two cycles. The battery 01 transported from the left side of FIG. 1 by the battery transport unit 30 is pushed up by a pin or the like (not shown) by the timing signal T1 and inserted into the cavity 6 while being guided by the tapered portion 4, and the tip contacts the packing 7. Stop at the point. When the battery 01 is inserted into the cavity 6, the battery 01 is surely inserted into the cavity 6 even if there is some deviation in the position and posture of the battery 01.

When the battery 01 comes into contact with the packing 7 and stops, the suction pump 28 operates in response to the signal T2, the solenoid valve 24 opens, and air near the lid at the tip of the lithium battery 01 is guided to the gas sensor 10. In the case of the lithium battery 01, particularly a lithium ion battery, the structure of the lid is complicated. If the sealing is incomplete, leakage of the electrolyte containing an organic solvent near the lid becomes a problem. Since the air in this portion is sucked by the suction pump 28, even a minute leak can be detected. This is because, when there is a leak, a very high concentration of solvent vapor is accumulated near the lid of the battery 01 compared to other parts, and this is sucked by the pump 28.

When the suction pump 28 is stopped, the output of the sensor 10 is sampled by the detection signal T3 and compared with a predetermined detection condition to check for the presence or absence of a leak. When these inspections are completed, the battery 01 is lowered by the battery transport unit 30 at the timing signal T1, and the heater 12 is turned on at the same time by the timing signal T4.
And the gas adhering to the surface of the base 14 or the sensor housing 8 or the like is degassed. At about the same time, the solenoid valve 26 is opened by the purge signal T5 to supply purge air, thereby purging the residual gas in the sensor housing 8 and the cavity 6. In FIG. 1, a black arrow indicates an air flow at the time of suction, and a white arrow indicates an air flow at the time of purging.

When the battery 01 is taken in and out of the cavity 6, an air current is generated, and as shown in FIG.
A spike-like noise is generated at zero. What is detected by the gas sensor 10 is gas remaining near the lid of the battery 01, which is sucked by the pump 28 and guided to the gas sensor 10. Therefore, when the battery 01 is inserted into the cavity 6, the air flow originally in the cavity 6 is generated by the gas sensor 10.
There is no need to contact The air current generated when the battery 01 is taken out of the cavity 6 is simply noise. Embodiments in which these points are improved are shown in FIGS.

In the embodiment shown in FIG. 3, for example, four holes 42 are provided near the tip of the cavity 6 so that air when the battery 01 is inserted escapes from the hole and when the battery 01 is taken out, the hole 6 Air is supplied to the

In the embodiment shown in FIG. 4, a large number of semicircular projections 47 are provided in the cavity 46, and an escape path 48 in which the battery 01 does not enter is provided between the projections 47. Therefore, when the battery 01 is inserted into the cavity 46, air escapes from the escape path 48, and when it is taken out, air enters from the escape path 48. Since the protrusion 47 is provided, even if the escape path 48 is provided, the positioning and the like of the battery 01 are not affected, and the air flows in and out of the periphery of the battery 01 almost uniformly.

In the embodiment shown in FIG. 5, a plurality of projections 57 whose surfaces are arc-shaped are provided in the cavity 56, and a groove between them is used as a relief path 58. Other points are the same as those of the embodiment of FIG.

In the embodiment shown in FIG. 6, the cavity 66 is formed in an elliptical shape, and escape paths 68, 68 are provided at two upper and lower positions in FIG.
However, in the embodiment of FIG.
It is inferior to the embodiment of FIGS. 3 to 5 in which air can enter and exit from the surroundings uniformly.

As another escape path, the diameter of the cavity 6 is slightly larger than the diameter required for inserting the battery 01 with the detection head 2 of FIG. The size may be increased by 10 to 30%. However, in this case, the positioning accuracy of the battery 01 is further reduced, so that the embodiment of FIGS. 3 to 6 is superior. Each of the embodiments in FIGS. 3 to 6 is the same as the embodiment in FIG. 1 except for the points particularly pointed out.

FIG. 7 shows the characteristics of the embodiments shown in FIGS. The vertical axis indicates the sensor output, all of which are the results of testing a lithium battery 01 having a leak, wherein a) to d) are the results in the embodiment of FIG. 1 and T3 is the detection timing signal. In a) to d), the first downward noise is the battery 0
Since the gas sensor 10 comes into contact with the organic solvent vapor due to the leakage of the electrolytic solution due to the noise due to the air current when inserting 1 and the suction by the suction pump 28, the sensor signal increases in about several seconds. Thereafter, spike-like noise is also generated in the airflow when the battery 01 is taken out. Even after the noise ends, the recovery of the sensor signal is slow, and if no purging or the like is performed, the detection cycle is about 40 to 60 seconds.

Here, after taking out the battery 01, the heater 1
When the switch 2 is turned on, the sensor signal shows a deep valley and then returns rapidly, and the detection interval can be reduced to, for example, about 20 seconds. This is because the heat from the heater 12 desorbs the gas adhering to the sensor accommodating section 8 and the sensor 10 and recovers the signal of the sensor 10. Also, even when only the purge gas is supplied, the recovery of the sensor signal is faster than when the purge gas is not supplied, and when both degassing by the heater and purging by the purge gas are performed as shown in d), a period of about 15 seconds, for example, is obtained. The battery 01 can be inspected.

FIGS. 7 (e) to 7 (g) show the inspection results in the embodiment of FIGS. 3 to 5, respectively.
The result when no purge gas is supplied is shown.
This is a result of performing both degassing by the purge gas and purging by the purge gas. The recovery of the sensor signal after the inspection is almost the same as the case of using both the heater and the purge gas in the embodiment of FIG. 1, and the noise when inserting the battery 01 and the noise when removing the battery 01 disappear. . This is due to the fact that the air flow accompanying the entry and exit of the battery 01 was released through the holes 42 and the release paths 48 and 58.

For this reason, in the embodiment, the lithium batteries 01 can be inspected one by one at intervals of, for example, about 15 seconds.
Since it leads to 0, even a small amount of leak can be reliably inspected. Here, if an escape route is provided as in the embodiment of FIGS.
The inspection can be performed more accurately, excluding the noise accompanying the entrance and exit of the battery 01.

FIGS. 8 and 9 show a modification in which the heat balance of the gas sensor 10 is maintained when the lithium battery 01 is inserted into the detection head 2 '. In each embodiment, the gas sensor 10 is not provided with a heater, and is indirectly heated by the heater 12 during heat cleaning. For this reason, the surface temperature of the gas sensor 10 and the sensor housing 8 is slightly higher than the ambient temperature, and when the lithium battery 01 is inserted into the cavity 6, the gas sensor 10 comes into contact with air at the ambient temperature, and the like. May be cooled slightly.

Therefore, in the modification of FIG. 8, the rise of the lithium battery 01 is detected by the timing signal T1 from the timing control unit 32, and the heater 12 is heated by the heater control unit 38, thereby cooling the gas sensor 10 by the ambient air. To keep the heat balance when the battery 01 rises. The heat value of the heater 12 for maintaining the heat balance may be smaller than the heat value at the time of heat cleaning. In a modification, as shown in FIG.
Although the rise of 1 and the heat generation of the heater 12 for heat balance are synchronized, it is not always necessary to synchronize the heat generation at least when the lithium battery 01 is inserted into the detection head 2 '.

In place of heating when the lithium battery 01 is inserted by the heater 12, for example, even when a heated purge gas is introduced from the purge passage 22, heat is supplied to the vicinity of the gas sensor 10 when the lithium battery 01 is inserted. , Can keep the heat balance. As shown by a dashed line in FIG. 8, a constant temperature bath 70 is provided on the upstream side of the purge path 22 to maintain the purge gas at a temperature slightly higher than the ambient temperature, and as shown by a dashed line in the waveform 5) of FIG. When the lithium battery 01 is inserted, a heated purge gas is supplied. At this time, for example, if the electromagnetic valve 24 is closed, the surrounding gas can be prevented from flowing into the sensor housing 8 from the battery side by the purge gas. The air compressed toward the sensor housing 8 by the lid of the battery 01 escapes from the gap of the cavity 6 or the like, and the purge gas heated to a temperature substantially equal to the average surface temperature is supplied to the sensor housing 8. , Can keep the heat balance constant.

In the above modification, the surface temperature of the lithium battery 01 is equal to the ambient temperature, and the temperature in the room where the detection head 2 'is installed is not uneven. However, when the surface temperature of the lithium battery 01 is higher than the surface temperature of the sensor accommodating section 8 due to a pre-process or the like, a Peltier element or the like is arranged in the sensor accommodating section 8 separately from the heater 12, and When the battery 01 is inserted, the sensor accommodating section 8 may be freely heated and cooled. Although the ambient temperature and the like were not measured in the modified example, the ambient temperature, the temperature of the sensor housing, the surface temperature of the lithium battery 01, and the like were measured using a thermistor, an infrared radiation thermometer, or the like. Control the
More precisely, the heat balance may be maintained.

In this embodiment, the inspection of the lithium battery 01 is shown. However, other types of batteries such as a nickel-metal hydride battery, a nickel cadmium battery, a dry battery, an inspection of dirt inside a beer bottle or a juice bottle, and an organic solvent are contained. It can be widely used for inspection of a small amount of leakage from a bottle or the like, or inspection for leakage or dirt of a retort food from a bag. That is, the present invention can be applied to a case in which a small amount of gas adhering to a product or a small amount of gas leaking from the product is used to continuously inspect products one by one online.

[Brief description of the drawings]

FIG. 1 is a sectional view of a detection head in a product inspection apparatus according to an embodiment.

FIG. 2 is a diagram showing timings of lifting / lowering a battery / suction of an atmosphere of a battery lid / detection of a leak / heat cleaning / purging in an embodiment.

FIG. 3 is a sectional view of a main part of a detection head according to a second embodiment.

FIG. 4 is a bottom view of a detection head according to a third embodiment.

FIG. 5 is a bottom view of a detection head according to a fourth embodiment.

FIG. 6 is a bottom view of a detection head according to a fifth embodiment.

FIG. 7 is a waveform chart of a gas sensor signal for a leaky battery in each embodiment.

FIG. 8 is a cross-sectional view of a detection head in a product inspection device according to a modification.

FIG. 9 is a diagram showing operation timings of a modified example.

[Explanation of symbols]

 Reference Signs List 01 lithium battery 2 detection head 4 taper section 6 cavity 7 packing 8 sensor housing section 10 gas sensor 12 heater 14 base 16 metal base 18 Teflon coating 20 suction path 22 purge path 24, 26 electromagnetic valve 28 suction pump 30 battery transfer section 32 timing control Unit 34 detection unit 36 setting unit 38 heater control unit 40 display unit 42 holes 46, 56, 66 cavities 47, 57 projections 48, 58, 68 relief path 70 constant temperature bath

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01M 10/42 H01M 10/42 Z 5H030 (72) Inventor Toshiji Sase 1-26-16 Honhaneda, Ota-ku, Tokyo Stock (72) Inventor Katsuo Ehara 4-18-6 Kamisagimiya, Nakano-ku, Tokyo (72) Inventor Aya Nishino 6-6 Josaicho, Takatsuki City, Osaka Prefecture Inside Yuasa Corporation (72) Inventor Shigeru Sano 6-6 Josai-cho, Takatsuki-shi, Osaka F-term in Yuasa Corporation (reference) 2F066 AA70 CC40 DD11 DD13 DE16 FF33 JJ20 LL05 MM12 2G046 AA01 BE05 BG04 BH03 BH04 BH09 CA09 DB02 DB05 DC13 EB01 2060 AA01 AB01 AB15 AC02 AE07 AE11 AE19 AF07 BA01 BB02 BC03 EA07 EB04 HB02 HB03 HB06 HD03 KA01 KA14 2G067 AA45 AA48 BB05 CC04 DD23 EE02 EE08 EE11 5H025 AA00 BB18 BB19 BB20 CC31 MM03

Claims (7)

[Claims] 1. A product inspection apparatus which detects a gas by bringing a gas sensor close to a product to be inspected, wherein a cavity for accommodating at least a part of the product, and a sensor accommodating portion communicating with the cavity. Is provided on the detection head,
A product inspection apparatus, wherein a gas sensor is accommodated in the sensor accommodating section, and a purge gas supply section for supplying a purge gas to the sensor accommodating section is provided. 2. A tapered portion or a convex curved surface communicating with the cavity and having a small diameter on the cavity side and a large diameter on the surface side of the detection head is provided on the entrance side of the cavity. Product inspection equipment. 3. The product inspection device according to claim 2, wherein a packing is provided in a deep portion of the cavity. 4. A method according to claim 1, wherein a flow path is provided in the cavity for releasing an air flow caused by taking products in and out of the cavity.
The product inspection device according to claim 1. 5. The product inspection apparatus according to claim 1, further comprising means for supplying heat to said sensor housing portion when inserting the product into the cavity. 6. Inserting at least a part of a product to be inspected into a cavity provided in a detection head, inspecting a gas from the product with a gas sensor in a sensor housing communicating with the cavity, and removing the product from the cavity. A method of inspecting a product, in which taking out and purging a sensor accommodating portion are repeated. 7. A large diameter tapered portion or convex surface on the surface side of the detection head and a small diameter tapered portion or convex surface on the cavity side are provided in the detection head in communication with the cavity, and the product is guided while being guided by the tapered portion or convex surface. 7. The method for inspecting a product according to claim 6, wherein the product is inserted into the cavity, and the packing is provided at the back of the cavity to position the product in the front / rear direction of the cavity.