JPH0513055A - Battery jar airtightness inspection device - Google Patents

Abstract

PURPOSE:To carry out strict inspection of airtightness by providing a gun for blowing hydrogen gas, and by blowing the hydrogen gas on a point of a battery jar to be inspected so as to detect hydrogen gas proceeded from a point of insufficient airtightness into the battery jar. CONSTITUTION:A pair of gas guiding tubes 15 are inserted into a safety valve discharge gas hole 11 of a lid 12 of a battery jar, so as to close the hole. A pump 7 is driven, and a gas discharge valve 1 is opened while a circulation valve 2 is closed, and the pressure is reduced while verification is carried out by a pressure gauge 8. The valve 1 is then closed while the valve 2 is opened, so that a gas inside of a battery is circulated through a filter 3, a check valve 4, a mass flow controller 5 into a hydrogen gas detection sensor 6. Hydrogen gas is blown from the outside of the battery to a lid adhered part 14 and to a terminal part 13 from a hydrogen cylinder 10 for a few seconds by using a hydrogen gas blowing gun 9. A point of insufficient connection is specified based upon the lapse of time for the blowing and the change in hydrogen gas concentration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery case airtight inspection device, and more particularly to a battery airtightness inspection device used for battery battery case airtight inspection.

[0002]

2. Description of the Related Art In a negative electrode gas absorption type sealed lead-acid battery, it is important to maintain the airtightness of the battery case in the storage characteristics of the battery. That is, if the airtightness of the battery case is not maintained, oxygen in the atmosphere penetrates into the battery through the location where the battery container is not airtight and reacts with the spongy lead of the negative electrode active material in the lead acid battery to produce the following reaction formula 1 / 2 O ₂ + Pb = PbO turns into PbO, and the negative electrode active material is oxidized.

When the negative electrode active material is oxidized, the discharge capacity of the battery decreases, so in a normal negative electrode gas absorption type sealed lead-acid battery, the battery case is strictly inspected before the injection of sulfuric acid.

In a conventional airtightness inspection method using a battery case airtightness inspection apparatus, a mixed gas of hydrogen or nitrogen is used as a search gas (hereinafter referred to as a search gas) as shown in FIG. A search gas is blown into each tank 21 through a safety valve exhaust hole 22 from a plurality of gas introduction pipes 23, and pressure is applied to a lid bonding portion 24 and a terminal portion 25 which are likely to cause airtightness failure. In order to collect the airtight leak hydrogen gas, the lid bonding portion 24
The side wall gas collecting plate 26 is brought into close contact with it. The air collected from the side wall of the battery is guided to the hydrogen gas sensor 27, and the presence or absence of hydrogen gas leaked due to airtight leakage is detected.

Similarly, in order to detect hydrogen gas leaked from the terminal portion 25, a terminal portion gas collection box 29 is brought into close contact with the terminal portion 25. The air sampled from the terminal portion 25 is guided to the hydrogen gas detection sensor 28, and the presence or absence of hydrogen gas leaked due to airtight leakage is detected.

As shown in FIG. 3, when there is a leaking portion in the battery case, when a search gas is blown and pressure is applied, hydrogen gas leaks from the portion and reaches the hydrogen gas detecting sensor 27 or 28, and the hydrogen gas detecting sensor is detected. The resistance change of 27 or 28 is output as a voltage output, and the airtightness of the battery case can be found.

[0007]

However, in this conventional battery case airtightness inspection method using the battery case airtightness inspection apparatus,
There was a problem as described below.

That is, due to the problem of the strength of the battery case, the pressure for injecting the search gas can be only about 0.4 atm. The search gas is diluted with the existing air in the battery case to reduce the hydrogen concentration. Therefore, the airtightness is a small hole,
When the search gas concentration is low, the leak amount of hydrogen gas is small and the boundary with the background atmosphere becomes unclear, making it difficult to detect airtightness. The mixing ratio of hydrogen gas as a search gas is also preferably high in hydrogen gas concentration, but the hydrogen gas concentration is 3% or less in order to select the hydrogen gas explosion lower limit concentration or less from the viewpoint of safety. Since the actual concentration of the search gas is as low as about 3%, the hydrogen gas is greatly diluted with the existing air in the battery case, which is a factor of lowering the leak detection sensitivity.

Further, since the negative electrode gas absorption type seal type battery normally absorbs oxygen in the internal air, the inside of the battery is usually in a state of being depressurized to atmospheric pressure. Since it is performed under pressure, depending on the welded state of the battery case adhesion part, even if it passes the pressure test, in the depressurized state there may be a case where the adhesion part of the battery case is distorted and the airtightness becomes poor. It was not a complete airtight test.

Further, when the capacity of the battery case for industrial use becomes several tens Ah to several hundreds Ah class, the battery container becomes large, and the area of the lid bonding portion and battery container joint portion to be inspected increases accordingly, and the battery container airtight inspection The device itself has a large scale and the cost of the device is high.

[0011]

In order to solve this problem, a battery case airtightness inspection apparatus of the present invention comprises a pair of gas introduction pipes to be inserted into a safety valve exhaust hole of a lid of the battery case, and a pair of gas introduction pipes. A line filter that is sequentially connected to one gas introduction pipe in series, a check valve, a mass flow controller, a hydrogen gas detection sensor, an exhaust pump, a pressure gauge, and an exhaust valve. , The other gas introduction pipe of the pair of gas introduction pipes connected between the exhaust pump and the pressure gauge of the piping system via a circulation valve, and the inspection location of the battery case connected to the hydrogen cylinder. It is equipped with a hydrogen gas spray gun for spraying hydrogen gas.

[0012]

With this configuration, the battery case airtightness inspection device of the present invention is
When detecting hydrogen gas that invades inside the battery case from a location where airtightness is poor, the sensor has a few ps because the hydrogen gas infiltrates and diffuses faster than oxygen gas in the atmosphere, which is an obstacle to actual batteries.
Since the hydrogen gas concentration of pm can be detected, a strict airtight inspection can be performed.

Further, even if the object to be inspected is wide such as a large battery case, the inspection can be easily performed by blowing the hydrogen gas to the entire place with the hydrogen gas blowing gun.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A battery airtightness inspection apparatus according to an embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, the battery case airtightness inspection apparatus of the present embodiment has a pair of gas introduction pipes 15 inserted into the safety valve exhaust hole 11 of the lid 12 of the battery case and one gas introduction of the pair of gas introduction pipes 15. It is composed of a line filter 3, a check valve 4, a mass flow controller 5, a hydrogen gas detection sensor 6, an exhaust pump 7, a pressure gauge 8, and an exhaust valve 1 which are sequentially connected to the pipe 15a in series. Connected to the exhaust system 7 of the pipe system and the pressure gauge 8 via the circulation valve 2 and the other gas introduction pipe 15b of the pair of gas introduction pipes 15 and the hydrogen cylinder 10. A hydrogen gas spray gun 9 for spraying hydrogen gas is provided at the inspection location of the connected battery case.

A pair of gas introducing pipes 15 are inserted into the safety valve exhaust hole 11 of the lid 12 of the battery case and hermetically sealed. Next, the pump 7 is operated, the exhaust valve 1 is opened, the circulation valve 2 is closed, and the gas in the battery case is measured by the pressure gauge 8 while the atmospheric pressure is about −
Evacuate to 0.4 kg / cm ² and check the reduced pressure. After that, the exhaust valve 1 is closed, the circulation valve 2 is opened, and the gas inside the battery is filtered by the filter 3, the check valve 4, and the mass flow controller 5.
To circulate in the hydrogen gas detection sensor 6. The mass flow controller 5 is attached in order to minimize fluctuations in sensitivity due to changes in the flow rate of the hydrogen gas detection sensor 6. The gas inside the battery is returned and circulated in the battery case. The circulation is for accumulating hydrogen gas inside the hydrogen gas detection sensor 6, and if strictness is not required,
You may discharge | emit with a constant pressure, taking in a fresh fresh air partly in a battery case. Since the battery case is depressurized, stress is applied from the outside to cause distortion, and if there is a leak hole in the lid bonding portion 14, hydrogen gas can easily pass through. In this state, the hydrogen cylinder 10 is attached to the lid bonding portion 14 and the terminal portion 13 from the outside of the battery.
More hydrogen gas is sprayed for several seconds using the hydrogen gas spray gun 9.

In FIG. 2, if the lid bonding portion 14 has a defective joint, hydrogen gas quickly enters the battery case from the defective joint and hydrogen gas is mixed into the internal gas. 6 can detect.

When hydrogen gas is successively sprayed onto the joint inspection location, the defective joint can be found from the progress of the spraying time and the change in hydrogen gas concentration.

Further, if the inspection is performed in an open atmosphere, even if 100% hydrogen gas is used as the search gas, the hydrogen gas is quickly diffused into the atmosphere, so that the risk of ignition and explosion is low. If 100% hydrogen gas is used as the search gas, the hydrogen gas concentration difference with the conventional battery case airtightness inspection apparatus is large, so that the detection capability of the system is improved 33 times when estimated by the detection gas concentration ratio.

[0020]

As is apparent from the above description of the embodiments, according to the battery case airtightness inspection apparatus of the present invention, the intrusion of hydrogen gas from the outside is prevented from changing the hydrogen gas concentration in the internal gas in the battery case. In order to measure with, the structure is simpler than that of the conventional battery case airtightness inspection device, and the same method can be applied to a small or large battery container.

It is possible to identify a defective joint by spraying the search gas and responding to the change in the concentration of the internal gas.
Since the search gas can be replaced with a hydrogen gas concentration of 100%, the detection sensitivity can be further improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a battery case airtightness inspection device according to an embodiment of the present invention, and a perspective view showing a state in which an airtightness test of a battery case is performed using the device

FIG. 2 is a graph showing an output characteristic of a hydrogen gas detection sensor when an airtightness test of a battery case is performed using the battery case airtightness inspection device according to an embodiment of the present invention.

FIG. 3 is a graph showing an output characteristic of a hydrogen gas detection sensor when an airtightness test of a battery case is performed using a conventional batterytightness tester.

FIG. 4 is a perspective view showing a state in which a conventional battery case airtightness inspection device is used to perform an airtightness test of the battery case.

[Explanation of symbols]

 1 Exhaust valve 2 Circulation valve 3 Line filter 4 Check valve 5 Mass flow controller 6 Hydrogen gas detection sensor 7 Exhaust pump 8 Pressure gauge 9 Hydrogen gas spray gun 10 Hydrogen cylinder 11 Safety valve Exhaust hole 12 Battery case lid 13 Terminal part 14 Lid Adhesive part 15 A pair of gas introduction pipes 15a One gas introduction pipe 15b The other gas introduction pipe

Claims (1)

Claim: What is claimed is: 1. A pair of gas introduction pipes inserted into a safety valve exhaust hole of a lid of a battery case, and a line filter sequentially connected in series to one gas introduction pipe of the pair of gas introduction pipes. A check valve, a mass flow controller, a hydrogen gas detection sensor, an exhaust pump, a pressure gauge, and a pipe system including an exhaust valve, and a circulation valve through the exhaust pump of the pipe system. An electric power provided with a hydrogen gas spray gun for spraying hydrogen gas to the inspection location of the battery case connected to the other gas introduction pipe of the pair of gas introduction pipes connected between the pressure gauges and a hydrogen cylinder. Tank airtightness inspection device.