JPH065125U - Battery status detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an inexpensive and highly reliable state detection device for a sealed storage battery. [Structure] A rubber packing 3 that is displaced in conjunction with the internal pressure of the storage battery and metal pieces 5a and 5b that come into contact with the rubber packing 3 due to the displacement of the rubber packing 3 are provided.
The shield 4 prevents the gas from being corroded by the exhaust gas. It detects the rise in the internal pressure of the storage battery due to the generation of gas at the end of charging, and is 95 to 10 regardless of age, temperature, charging current, etc.
The 0% state of charge can be detected accurately.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a storage battery state detection device.

[0002]

[Prior art]

 Storage batteries include so-called open type and closed type.

The open type lead-acid battery is also called a liquid lead-acid battery, and has a flowing electrolyte in the battery. Almost all lead-acid batteries have this structure, and due to their long history, various proposals have been made to detect the battery state. The main ones are the liquid level detection method that focuses on the electrolyte solution that decreases by charging, the electrolyte specific gravity detection method that focuses on the electrolyte specific gravity value that has a close correlation with the storage battery capacity, and the capacity. There are various open circuit voltage detection methods that focus on open circuit voltage that has a correlation with.

On the other hand, the closed type has a newer history than the open type, and the state cannot be detected as easily as the open type, so that the state is not always sufficiently detected. In the latter case, the closed type is the same as the open type because there is no flowing electrolytic solution in the storage battery and the electrolytic solution is held in the mat-shaped separator, so the specific gravity of the electrolytic solution and the electrolytic solution surface are It is because it is practically impossible to measure the position. For this reason, the only method that is currently used to detect the state of a closed storage battery is the capacity determination based on the open circuit voltage measurement described above. However, in recent years, the use of sealed storage batteries has been remarkably widespread, and storage battery management through accurate state detection is becoming more important even in sealed batteries.

[0005]

[Problems to be solved by the device]

 The charging characteristics of the sealed type change significantly depending on whether it is new or old and the temperature conditions, so it is much more difficult to control than the open type. As is well known, the sealed storage battery utilizes a gas absorption reaction inside the storage battery. In sealed lead acid batteries, a new free electrolyte exists in the battery when it is new and covers the cathode plate that absorbs gas, which reduces the gas absorption reaction and exhibits the same charging characteristics as an open lead acid battery. As a result, the end-of-charge voltage reaches a voltage of 2.6 to 2.7 V / cell even during normal charging. However, if the free electrolyte is gradually decomposed into gas and exhausted to the outside and the electrolyte in the separator becomes a stub with no free electrolyte over time, the gas absorption efficiency at the cathode plate rises and charging The terminal voltage drops significantly to 2.4-2.5V / cell. Therefore, if a high charging voltage is set, proper charging can be performed at the beginning of use, but overcharging will occur at the end of use. Conversely, if the charging voltage is set to a low value, incomplete charging will occur in the early stages of use. For this reason, charging a sealed lead-acid battery with a conventional simple charger causes an extreme overcharge. Therefore, a dedicated charger must be used for the sealed type.

As the dedicated charger, a trickle charge type one in which the charging current is limited to the gas absorption range is often used, but this has a drawback that it takes a long time to charge although the charger cost is low. For this reason, when rapid charging is required, the current situation is to use a constant-voltage / constant-current charging method charger. This results in a problem that the constant voltage setting is difficult and the cost is high because the charging end voltage changes as described above, though the charging time becomes short.

The present invention has been made to solve the above problems, and an object thereof is to provide an inexpensive and highly reliable state detection device for a sealed storage battery. .

[0008]

[Means for Solving the Problems]

 Therefore, a cylindrical exhaust port, a rubber packing, a rubber packing support plate, two metal pieces, a protective cap, and a shield are provided, and the cylindrical exhaust port also serves as a valve seat for mounting the rubber packing. The rubber packing has the function of an exhaust valve and also has a pressure sensitive part that is displaced according to the fluctuation of the internal pressure of the storage battery.The rubber packing support plate has a rubber packing that reduces the internal pressure of the storage battery. The two metal pieces are connected to the power supply terminal and the other to the output terminal, and the two metal pieces are contacted and released by interlocking with the displacement of the pressure sensitive part of the rubber packing. The protective cap is for detecting and outputting the status, the protective cap is for accommodating and protecting the rubber packing and the two metal pieces, and the shield is for the valve accommodating part inside the protective cap. One of the divided to the metal piece housing part, by two metal pieces to storage battery state detection device is intended to prevent from being corroded by the exhaust gas, is to solve the above problems.

[0009]

[Action]

 When charging the storage battery, the internal pressure of the storage battery rises due to the gas generated by the decomposition of the electrolytic solution at the end of charging regardless of the old and new storage batteries, the ambient temperature, the charging current, etc. In addition, the internal pressure of the sealed storage battery is always in a depressurized state during normal charging or leaving. The present invention focuses on this. That is, a rubber packing having a function of an exhaust valve and having a pressure sensitive portion that is displaced according to the fluctuation of the internal pressure of the storage battery is attached to the cylindrical exhaust port, and two metal pieces arranged close to this are provided. One of which is connected to the power supply terminal and the other of which is connected to the output terminal is brought into contact with and separated from the pressure sensitive part of the rubber packing, thereby detecting and outputting the state of the storage battery. Even if the internal pressure of the storage battery decreases, the rubber packing support plate prevents the rubber packing from collapsing and deforming, so that external air does not enter the storage battery. The rubber packing and the two metal pieces are protected by a protective cap. In addition, since the shielding body divides the inside of the protective cap into the valve storage portion and the two metal piece storage portions, the two metal pieces are not corroded by the exhaust gas. With such a configuration, at the end of charging, the two metal pieces come into contact with each other due to the expansion of the rubber packing and become electrically conductive, and an electric signal is output. When the internal pressure of the storage battery decreases, the rubber packing contracts and restores, so the two conductors that were in contact with each other are released and the electrical continuity is released. Therefore, the pressure of the gas generated at the end of charging is accurately detected, and charging control by accurate state detection becomes possible.

[0010]

【Example】

 The present invention will be described in detail with reference to specific examples. FIG. 1 is a sectional view showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a cylindrical exhaust port, and a rubber packing 3 is attached to the outer peripheral surface of the upper end as a valve seat. The rubber packing 3 has the function of an exhaust valve, and also has a pressure sensitive portion 3a that is displaced with the fluctuation of the internal pressure of the storage battery (in the embodiment, the vertical direction in the drawing). Reference numeral 2 is a rubber packing support plate disposed between the rubber packing 3 and the valve seat, and has a hole 2a for exhaust. The rubber packing 3 and the support plate 2 are in close proximity. Reference numerals 5a and 5b are thin metal pieces having a spring characteristic and form the electrical contact Y. The metal pieces 5a and 5b are arranged near the rubber packing 3 with a gap of 0.5 to 1 mm. These metal pieces 5a and 5b have their spring curved surfaces parallel to each other and also to the pressure sensitive portion 3a surface of the rubber packing 3. Further, one end is fixedly supported by the protective cap 7, and is led out of the protective cap 7 to form an output terminal and a power supply terminal, respectively. The other end is kept at a predetermined interval by an insulator 6. A cap 7 protects the rubber packing 7 and the metal piece 5. Reference numeral 4 denotes a shield, which is configured to expand and contract as the pressure sensitive portion 3a of the rubber packing 3 is displaced. The shield 4 is for isolating the electrical contact Y from the valve portion X. Reference numeral 8 denotes an exhaust port provided at the lower end of the protective cap pedestal 7a, through which the gas inside the storage battery produced by opening the valve seat X is exhausted to the outside. 9 is a battery case lid and 10 is a battery case.

FIG. 2 shows an example of the shape of the metal pieces 5a and 5b forming the electrical contact Y. When the metal piece 5a in the lower part of the drawing is displaced upward, the metal piece 5a in the upper part of the drawing comes into contact with the metal piece 5b. It may have any shape as long as it forms a through circuit.

In the storage battery, when the state of charge reaches 95 to 100%, gas is generated by electrolysis and the internal pressure of the storage battery rises sharply. On the contrary, if this pressure increase is detected, accurate charge control can be performed. The present invention has been made in view of this fact, and in order to detect a pressure rise, two metal pieces 5a and 5b are arranged close to the rubber packing 3 attached to the exhaust port, and the rubber packing 3 is placed. Displacement due to expansion and contraction of the pressure sensitive part 3a of 3 is detected by the metal pieces 5a and 5b, and an electric signal is transmitted to a control circuit connected to 5a and 5b, whereby proper charging control is performed. To do. As will be described later, the rubber packing 3 generally opens when the internal pressure of the storage battery is about 1.3 atm. On the other hand, when the pressure is reduced, it reaches about 0.2 atm. Pressurization is smaller than depressurization, but charging control detects the displacement of the pressure sensitive part 3a in the pressurized state. Therefore, the metal piece 5a should be as thin as possible, and even if the pressure sensitive part 3a is slightly displaced. If so, it is necessary to make the displacement in synchronization.

The gas generated in the storage battery passes through the valve portion X and is exhausted to the outside. Exhaust gas inevitably contains sulfuric acid, which may corrode the electrical contact portion Y. If the metal pieces 5a, 5b come into contact with each other, even if the metal pieces 5a, 5b come into contact with each other, poor conduction occurs. In order to prevent this, the valve portion X and the electrical contact Y must be completely shut off. The shield 4 is provided for this purpose. As the shield 4, any material may be used as long as it is easily deformable and has no gas impermeability.

As is well known, the internal pressure of a sealed storage battery may drop to about 0.2 atm during depressurization. In this case, the pressure difference between the inside and outside of the storage battery is 0.8 atm. On the other hand, at the time of pressurization, in order to minimize the expansion of the battery case, the valve is opened when the internal pressure reaches 1.2 to 1.3, and the internal pressure is reduced. As described above, the pressure difference inside the storage battery is 0.2 to 0.3 atm when the pressure is increased, while the pressure difference at decompression is large at 0.8 atm. Therefore, if there is a structurally weak part, it may cause damage, so the battery case and lid are stronger than the open type storage battery. The structurally weak part of the sealed storage battery is the rubber packing part, and a large amount of stress is always applied when depressurizing or pressurizing, and the rubber packing shape is distorted. As a result, air enters the storage battery and the negative electrode plate is oxidized, resulting in an inactive state in which the capacity cannot be recovered. Since the tightness of the valve seat X thus becomes a major life factor for the sealed storage battery, great care is paid to the valve structure. The rubber packing support plate 2 according to the present invention is for preventing the pressure sensitive portion 3a from being depressed inside the storage battery and deteriorating the sealing characteristic, and is an important functional component.

[0015]

[Effect of device]

 As mentioned above, the end-of-charge voltage of a sealed storage battery changes drastically with age, temperature, charging current, etc. Therefore, a definitive charging method for rapid charging has not been established yet. Therefore, in the case of rapid charging, constant current charging is generally used, but it requires twice as much cost as the open-type quasi-constant electric system. However, the storage battery state detection device according to the present invention detects a rise in the internal pressure of the storage battery due to gas generation at the end of charging, and can accurately determine the 95 to 100% state of charge regardless of age, temperature, charging current, etc. If it can be detected, it will be. Moreover, it is a simple device consisting of a rubber packing and two metal pieces, and since the electrical contact parts are reliably protected, there is no corrosion deterioration. Therefore, it is inexpensive and highly reliable, and its practical value is great.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a view showing a shape of a metal piece according to an embodiment of the present invention.

[Explanation of symbols]

 1 Cylindrical Exhaust Port 2 Rubber Packing Support Plate 3 Rubber Packing 3a Pressure Sensitive Section 4 Shield 5 Metal Piece 7 Protective Cap

Claims (1)

[Scope of utility model registration request] 1. A cylindrical exhaust port (1), a rubber packing (3), a rubber packing support plate (2), two metal pieces (5a, 5b), a protective cap (7), and a shield. (4), the cylindrical exhaust port (1) also serves as a valve seat for mounting the rubber packing (3), and the rubber packing (3) has the function of an exhaust valve and the internal pressure of the storage battery. The rubber packing support plate (2) is for preventing the rubber packing (3) from being depressed and distorted due to a decrease in the internal pressure of the storage battery. Yes, one of the two metal pieces (5a, 5b) is connected to the power supply terminal and the other is connected to the output terminal.
It is for detecting and outputting the state of the storage battery by contacting and releasing in conjunction with the displacement of a), and the protective cap (7) stores and protects the rubber packing (3) and the two metal pieces (5a, 5b). The shield (4) divides the inside of the protective cap into a valve storage part and two metal pieces (5a, 5b) storage parts, and the two metal pieces (5a, 5b) are exhaust gas. A storage battery state detection device that prevents corrosion by the battery.