JP2009081051A - Lead acid storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead acid storage battery in which installation of a liquid plug is facilitated by preventing inclination of the liquid plug to the liquid port, when a male screw portion of the liquid plug is screwed to a female screw portion on the inner circumference of the liquid port. <P>SOLUTION: When a cylindrical portion 802 of a liquid plug 8 is inserted into a battery case 1 through a liquid port 7 and the male screw portion 803 of the liquid plug 8 is screwed to the female screw portion 704 of the liquid port 7, a liquid plug positioning part 20 which positions the liquid plug 8 so as to make coincide the center axial line of the male screw portion of the liquid plug 8 with the center axial line of the female screw portion of the liquid port 7 by engaging with the outer circumference of the cylindrical part 802 of the liquid plug 8, before the male screw portion 803 reaches the position of starting engagement with the female screw portion 704, is installed at the lower side of a lid 3 of the battery base. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lead storage battery in which a liquid spout is attached to a liquid spout provided on a lid portion of a battery case.

  The lead-acid battery is composed of a battery case main body and a lid part that closes an opening at the upper end of the battery case main body, and includes a battery case that is partitioned into a plurality of cell chambers. In each cell chamber inside the battery case, an electrode plate group is accommodated together with an electrolytic solution. The lid portion of the battery case is provided with a liquid port communicating with each cell chamber, and a liquid port plug is attached so as to close each liquid port. On the inner periphery of each liquid port, a female screw portion used for attaching a liquid port plug is formed. The liquid spigot is a male part formed on the outer periphery of a head part at least partially exposed to the outside of the battery case, a cylindrical part having a circular section extending downward from the lower end of the head part, and the upper part of the cylindrical part. The cylindrical portion is inserted into the battery case through the liquid port, and the male screw portion is screwed to the female screw portion and attached to the lid portion of the battery case. This type of lead-acid battery is disclosed in Patent Document 1, for example.

When assembling this type of lead-acid battery, after the electrode plate group is accommodated in each cell chamber in the battery case, the intermediate pole column of the electrode plate group in the adjacent cell chamber is penetrated through the partition between the cell chambers. It is electrically connected by a welded part (inter-cell connection part), a lid part is arranged so as to close the opening at the upper end of the battery case body, and the lid part is joined to the battery case body by heat sealing (thermal welding). . Then, electrolyte solution is inject | poured in each cell chamber from each liquid port provided in the cover part, and each liquid port is closed with a liquid port stopper.
JP 11-345605 A

  As described above, the lead screw is attached to the lid part of the battery case by screwing the male screw part of the liquid mouth plug into the screw part on the inner periphery of the liquid mouth provided on the lid part of the battery case. In a storage battery, when the liquid spigot is inserted into the liquid spout and the male threaded portion of the liquid spout starts to engage with the female threaded portion on the inner periphery of the liquid spout, the central axis of the liquid spout is the liquid Since it may be inclined with respect to the center axis of the mouth, both screw parts mesh smoothly, and it takes time to install the liquid spigot, or the screw part is screwed forcibly with the liquid spigot tilted. The screw thread could be damaged.

  The object of the present invention is to insert the liquid spigot into the liquid spout and start screwing between the male screw portion of the liquid spout and the female screw portion on the inner periphery of the liquid spout. A lead-acid battery that prevents the axis from being inclined with respect to the central axis of the liquid port, and that allows the liquid port plug to be always easily attached without causing damage to the thread. It is to provide.

  The present invention includes a battery case in which an electrode plate group is housed together with an electrolyte, a liquid port having a female screw portion on the inner periphery is formed in a lid, and a cross section extending downward from a head and a lower end of the head Has a circular cylindrical part and a male screw part formed on the outer periphery of the upper part of the cylindrical part, and the cylindrical part is inserted into the battery case through the liquid port, and the male screw part becomes a female screw part. The present invention relates to a lead storage battery including a liquid spigot screwed and attached to a lid portion of a battery case.

  In the present invention, in the process where the cylindrical portion of the liquid spigot is inserted into the battery case through the liquid port and the male screw portion is screwed to the female screw portion, the male screw portion is screwed with the female screw portion. Before reaching the starting position, fit the liquid stopper to the outer periphery of the tubular part of the liquid stopper so that the central axis of the male screw part of the liquid stopper matches the central axis of the female thread part of the liquid mouth. A liquid stopper positioning portion for positioning is provided on the lower surface side of the lid portion.

  When configured as described above, before the male threaded portion of the liquid spigot inserted into the liquid spout starts to engage with the female threaded portion on the inner periphery of the liquid spout, the cylindrical portion of the liquid spout is It can be fitted to the stopper positioning part so that the central axis of the male screw part of the liquid port plug can be aligned with the central axis of the female screw part of the liquid port. When the screwing with the female thread portion is started, the central axis of the liquid spout can always be made to coincide with the central axis of the liquid spout. Therefore, when the male threaded portion of the liquid spout is screwed into the female threaded portion on the inner periphery of the liquid spout, the central axis of the liquid spout can be prevented from being inclined with respect to the central axis of the liquid spout. When attaching the plug, it is possible to prevent the liquid plug and the screw thread of the liquid port from being damaged, or screwing of the liquid plug to be difficult.

  In a preferred aspect of the present invention, the liquid spout positioning portion has a pair of positioning pieces that have an inner peripheral surface that is fitted to the outer periphery of the cylindrical portion and that are disposed so as to be opposed to the radial direction of the liquid port. Thus, the upper ends of the pair of positioning pieces are integrated with the peripheral portion of the opening at the lower end of the liquid port. In this case, the pair of positioning pieces are provided so that the lower ends thereof terminate at positions corresponding to the upper limit level of the electrolytic solution in the battery case, and the pair of positioning pieces are the electrolyte solution in the battery case. Also serves as an electrolyte surface level defining protrusion for defining the upper limit level of the electrolyte.

  When configured as described above, the position of the electrolyte level regulation protrusion provided on the lower surface of the lid of the battery case in order to define the upper limit level of the electrolyte in the liquid stopper positioning portion, and the liquid stopper on the projection Since the liquid spout positioning part can be provided simply by setting it to a position suitable for providing the positioning function, the tilting of the liquid spout is prevented without complicating the structure of the lid of the battery case. Can have a function.

  In a liquid port plug used for a lead-acid battery, a vent opening that is opened in the radial direction of the cylindrical part is often provided at the lower end of the cylindrical part. In this case, the vent hole of the liquid port plug is positioned between the pair of positioning pieces in a state where the screwing of the male screw part of the liquid port plug and the female screw part of the liquid port is completed. It is preferable to provide a pair of positioning pieces, a male screw portion of the liquid spout and a female screw portion of the liquid spout.

  When configured as described above, the vent at the lower end of the liquid spout can be opened in the space between the pair of positioning pieces, so that the vent is closed by the liquid spout positioning unit. Can be prevented.

  As described above, according to the present invention, before the male threaded portion of the liquid spout inserted into the liquid spout begins to engage with the female threaded portion on the inner periphery of the liquid spout, Since the central axis of the male screw part of the liquid port can be aligned with the central axis of the female screw part of the liquid port, the male screw part of the liquid mouth plug can When screwed into the female thread portion on the inner periphery of the mouth, the center axis of the liquid mouth plug can always be made to coincide with the center axis of the liquid mouth. Therefore, when the male screw portion of the liquid port plug is screwed into the female screw portion on the inner periphery of the liquid port, the central axis line of the liquid port plug is prevented from being inclined with respect to the central axis line of the liquid port. It is possible to prevent the liquid spigot and the screw thread of the liquid spout from being damaged or the screwing of the liquid spout to be difficult when the liquid spigot is attached.

  In the present invention, the liquid port stopper positioning part is constituted by a pair of positioning pieces that are arranged so as to face the radial direction of the liquid port and the upper end is integrated with the peripheral part of the opening part at the lower end of the liquid port, When the lower end of each of the pair of positioning pieces is terminated at a position corresponding to the upper limit level of the electrolyte in the battery case, the upper limit level of the electrolyte in the battery case is set on the pair of positioning pieces. Therefore, it is possible to provide a function of preventing the inclination of the liquid spout without complicating the structure of the lid portion of the battery case.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. 1 to 7 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a configuration of a main part of a lead storage battery according to the embodiment of the present invention, and FIG. FIG. 3B is a front view showing a partial cross section of the liquid spigot used, FIG. 3B is a front view showing a partial cross section of a modification of the liquid spigot used in the lead storage battery according to the present invention, and FIG. The longitudinal cross-sectional view which showed the part of the liquid port of the cover part of the battery case of the lead storage battery concerning this embodiment, and the part of the liquid port stopper positioning part, FIG. 4 is below the principal part of the part shown by FIG. It is the bottom view seen from. FIG. 5 is a cross-sectional view showing a process of attaching the liquid spigot to the liquid spout in this embodiment, FIG. 6 is a cross-sectional view showing a state in which the liquid spigot is attached to the liquid spout in this embodiment, and FIG. FIG. 7 is a bottom view of the main part of the part shown in FIG. 6 as viewed from below.

  In FIG. 1, reference numeral 1 denotes a battery case comprising a rectangular battery case body 2 having an open upper end and a lid part 3 for closing the opening of the battery case body. The inside of the battery case 1 is along the longitudinal direction thereof. It is divided into multiple cell rooms. FIG. 1 shows one cell chamber 4. In each cell chamber 4, an electrode plate group 5 is accommodated together with an electrolytic solution 6. The lid portion 3 is provided with a liquid port 7 communicating with each cell chamber, and a liquid port plug 8 is attached to each liquid port 7.

  As shown in FIG. 3, each liquid port 7 includes a first part 701 provided through the lid 3 of the battery case, and a boss protruding downward from a peripheral part at the lower end of the first part 701. The second portion 703 is formed inside the portion 702, and the inner diameter of the first portion 701 is set larger than the inner diameter of the second portion 703. A spiral thread 705 of approximately one turn that defines the female screw portion 704 is formed on the inner periphery of the second portion 703 of the liquid port.

  As shown in FIG. 1 (A), the liquid stopper 8 is arranged in a state of protruding upward from the upper surface of the lower half portion 801a and the lid portion of the battery case that fit into the liquid port 7. A disc-shaped head portion 801 formed of a portion 801b and a cylindrical portion 802 having a circular cross section extending downward from the lower end of the head portion 801 are integrally formed on the outer periphery of a portion near the upper portion of the cylindrical portion 802. A male screw portion 803 that is screwed into the female screw portion 704 of the liquid port 7 is formed. The lower end of the cylindrical portion 802 is closed by a bottom wall portion 804 provided in an inclined state with respect to the axis of the cylindrical portion, and the lowermost end portion of the bottom wall portion 804 and the outermost wall portion 802a of the cylindrical portion 802 are disposed. A vent 805 having an opening 805a that opens in the radial direction of the cylindrical portion and an opening 805b that opens downward is formed across the lower end. The head portion 801 is formed with an exhaust hole 801c that allows the inside of the tubular portion 802 to communicate with the outside air. Inside the tubular portion 802, the electrolyte that has entered the tubular portion leaks outside through the exhaust hole 801c. A splash-proof plate (not shown) or the like is provided to prevent this. The electrolyte that has entered the cylindrical portion 802 of the liquid plug 8 from the vent 805 is blocked by the splash-proof plate in the cylindrical portion 802 and falls onto the bottom plate 804, and is vented along the inclined surface of the bottom plate 804. It is led to the port 805 and returned from the vent hole into the battery case.

  The electrode plate group 5 has, for example, a structure in which cathode plates and anode plates are alternately stacked via separators, and an upper end of each of the series of cathode plates is connected to each other at the upper end. A cathode strap 10 is provided, and an anode strap 11 is provided to connect the ears provided on the top of each of the series of anode plates. The cathode strap 10 and the anode strap 11 in each cell chamber other than the cell chamber provided at the end portion of the battery case pass through the inter-cell connecting portion (not shown) penetrating the partition wall that partitions the cell chambers, and the cathode strap in the adjacent cell chamber. And connected to the anode strap.

  In the present invention, in the process in which the cylindrical portion 802 of the liquid spout 8 is inserted into the battery case 1 through the liquid port 7 and the male screw portion 803 is screwed to the female screw portion 704, the male screw portion 803 is inserted into the female screw portion 704. Before reaching the position to start screwing with the screw portion 704, it is fitted to the outer periphery of the cylindrical portion 802 of the liquid spout 8 and the central axis of the male screw portion 803 of the liquid spout 8 is set to the female screw of the liquid spout 7. A liquid stopper positioning portion 20 that positions the liquid stopper 8 so as to coincide with the central axis of the portion 704 is provided on the lower surface side of the lid portion 3.

  The liquid spout positioning unit 20 is fitted to the outer periphery of the cylindrical portion 802 of the liquid spout 8 and the central axis of the male threaded portion 803 of the liquid spout 8 matches the central axis of the female threaded portion 704 of the liquid spout 7. However, in this embodiment, the liquid spout positioning portion 20 is fitted to the outer periphery of the tubular portion 802 of the liquid spout 8. It has a pair of positioning pieces 20a, 20a which have peripheral surfaces 20a1, 20a1 and are arranged so as to face each other in the radial direction of the liquid port 7 with their inner peripheral surfaces facing each other. The upper ends of the pieces 20 a and 20 a are integrated with the periphery of the opening at the lower end of the liquid port 7. These positioning pieces can be formed when the lid 3 of the battery case is formed. Each of the pair of positioning pieces 20 a, 20 a is made of a plate-like member having a circular cross section, and the inner peripheral surfaces 20 a 1, 20 a 1 each have a central axis that coincides with the central axis of the liquid port 7. When the cylindrical portion 802 of the liquid spout 8 is fitted to the inner peripheral surfaces 20a1 and 20a1 of the pair of positioning pieces 20a and 20a, the male screw portion 803 of the liquid spout 8 is fitted. The liquid port plug 8 is positioned so that the central axis line coincides with the central axis line of the female screw portion of the liquid port 7.

  The pair of positioning pieces 20a, 20a are provided such that the lower ends thereof are terminated at positions corresponding to the upper limit level of the electrolyte 6 in the battery case 1, and the pair of positioning pieces 20a, 20a are provided in the battery case. It also serves as an electrolytic solution surface level defining projection for defining the upper limit level of the electrolytic solution inside. That is, when the liquid level of the electrolyte viewed through the liquid port 7 has reached the position of the lower end of the positioning pieces 20a, 20a, a pair of electrolyte levels is reached so that the level of the electrolyte reaches the upper limit. The positions of the lower ends of the positioning pieces 20a, 20a are set.

  Further, in the present invention, in a state where the male threaded portion 803 of the liquid spout 8 and the female threaded portion 704 of the liquid spout have been screwed together, as shown in FIG. Positioning pieces 20a, 20a, a male screw portion 803 and a female screw portion 704 are provided so as to be positioned between the positioning pieces 20a, 20a.

  In the lead storage battery of this embodiment, when the liquid spigot 8 is attached to the liquid spout 7, the tubular portion 802 of the liquid spout 8 is inserted into the liquid spout 7 as shown in FIG. When the cylindrical portion 802 of the liquid spout 8 is inserted into the liquid port 7, before the male screw portion 803 comes into contact with the female screw portion 704, the cylindrical portion 802 is inserted into the positioning pieces 20a and 20a as shown in FIG. Fit around. As a result, the liquid spigot 8 is positioned so as not to tilt with respect to the liquid spout 7, and the central axis of the male screw portion 803 is made to coincide with the central axis of the female screw portion 704. Accordingly, after the male screw portion 803 hits the female screw portion 704, the male screw portion 803 can be correctly screwed into the female screw portion 704 by rotating the liquid mouth plug 8, and the liquid mouth plug 8 is stopped. By rotating and tightening to the end, as shown in FIG. 6, the screwing of the male screw portion 803 and the female screw portion 704 is completed, and the liquid spigot 8 can be correctly attached to the lid portion of the battery case. In the present embodiment, in the state where the male threaded portion 803 of the liquid spout 8 and the female threaded portion 704 of the liquid spout are completed in this way, as shown in FIG. Since the positioning pieces 20a, 20a, the male screw portion 803, and the female screw portion 704 are provided so as to be positioned between the pair of positioning pieces 20a, 20a, the ventilation hole 805 is positioned in the positioning pieces 20a, 20a. Can be prevented from being blocked.

  When the vent of the liquid spigot has an opening 805a in the radial direction of the tubular portion 802 as in the above embodiment, the male screw of the liquid spigot 8 does not block the opening 805a. The positioning piece 20a is such that the vent 805 of the liquid port plug is positioned between the pair of positioning pieces 20a, 20a in a state where the screwing of the portion 803 and the female screw portion 704 of the liquid port is completed. 20a and a male screw portion 803 and a female screw portion 704 are preferably provided. However, the present invention is not limited to such a configuration, and the case where the vent 805 of the liquid spigot 8 has an opening 805b on the lower side is also shown in FIGS. As described above, in the state where the male threaded portion 803 of the liquid spout 8 and the female threaded portion 704 of the liquid spout are completed, the vent hole 805 of the liquid spout 8 has the inner periphery of one positioning piece 20a, 20a. Positioning pieces 20a, 20a and male and female screw portions may be provided so as to face each other. Even in such a configuration, the exhaust can be performed through the opening 805b below the liquid spigot 8, so that there is no problem.

  In the above embodiment, the bottom wall portion 804 of the liquid spout 8 is inclined, but the configuration of the liquid spout is not limited to the above example. For example, as shown in FIG. 2B, the liquid spigot 8 has a bottom wall portion 804 'provided so as to be orthogonal to the central axis of the cylindrical portion 802, and the center of the bottom wall portion 804' The present invention can also be applied to the case where the vent 805 'is formed in the portion. In this case, it is not necessary to give special consideration to the relationship between the circumferential position of the liquid spout 8 and the positioning pieces 20a, 20a in the state where the mounting of the liquid spout 8 is completed.

  A lid portion of a B19 size top flat battery case having no liquid stopper positioning portion was prepared as a sample of a conventional example. Further, similarly to the embodiment shown in FIGS. 1 to 7, a lid portion of a B19 size top flat battery case in which a pair of positioning pieces are integrally provided at the lower end of the liquid port relates to the embodiment of the present invention. Created as a sample. The following first to third experiments were performed using these samples.

In the first experiment, the liquid port plug was inserted into the liquid port of the lid portion of the B19 size battery case created as a conventional example while guiding the liquid port plug so as not to tilt with respect to the liquid port using a special jig, Screw the male screw part of the liquid spigot into the female screw part of the liquid spout, and measure the protruding height of the head of the liquid spout from the top surface of the lid when the liquid spigot is fully tightened did.
In the second experiment, the liquid mouth plug was inserted into the liquid mouth of the lid portion of the B19 size battery case created as a conventional example so that the inclination with respect to the liquid mouth was maximized, and the male screw portion of the liquid mouth stopper Was screwed into the female screw part of the liquid port, and the protruding height of the head of the liquid port plug from the upper surface of the lid part in a state where the liquid port plug was fully tightened was measured. In this case, the maximum inclination angle of the liquid stopper with respect to the liquid opening was about 8 °.
In the third experiment, a liquid plug was inserted into the liquid port of the lid portion of the B19 size battery case prepared as the basis of the embodiment of the present invention so that the inclination with respect to the liquid port was maximized, The male screw part of the liquid spigot was screwed into the female screw part of the liquid spout, and the protruding height of the head of the liquid spout from the top surface of the lid part was measured with the liquid spigot fully tightened. . In this case, the maximum inclination angle of the liquid stopper with respect to the liquid opening was about 3 °.

  The above first to third experiments were performed for three samples, respectively, and the maximum protrusion height of the head of the liquid spout from the upper surface of the lid (in each part of the head, of the lid FIG. 10 shows the results of measurement of the protrusion height of the portion most protruding from the upper surface and the minimum value (protrusion height of the portion of the head that does not protrude most from the upper surface of the lid). In FIG. 10, the results of the first to third experiments are shown as “upright”, “conventional product” and “invention product”, respectively, and the minimum value of the protruding height is shown by a white bar graph. The maximum value is shown as a bar graph with diagonal lines inside. The minimum and maximum values shown in FIG. 10 indicate the average values of the minimum and maximum values measured for three samples.

  A lid portion of a D26 size top flat battery case having no liquid stopper positioning portion was prepared as a sample of a conventional example. Similarly to the embodiment shown in FIGS. 1 to 7, a lid portion of a D26 size top flat type battery case in which a pair of positioning pieces are integrated at the lower end of the liquid port is related to the embodiment of the present invention. Created as a sample. Using these samples, the following first to third experiments were conducted in the same manner as in Example 1.

In the first experiment, the liquid mouth plug was inserted into the liquid mouth of the lid portion of the D26 size battery case prepared as a conventional example while being guided so as not to tilt with respect to the liquid mouth by a special jig. The male thread part of the stopper was screwed into the female thread part of the liquid mouth, and the protruding height from the upper surface of the lid part of each part of the head part of the liquid mouth stopper in a state where the liquid mouth stopper was fully tightened was measured.
In the second experiment, the liquid port plug was inserted into the liquid port of the lid part of the D26 size battery case prepared as a conventional example so that the inclination with respect to the liquid port was maximized, and the male screw part of the liquid port plug Was screwed into the female screw part of the liquid mouth, and the protrusion height from the upper surface of the lid portion of each part of the head part of the liquid mouth plug was measured in a state where the liquid mouth plug was fully tightened. In this case, the maximum inclination angle of the liquid stopper with respect to the liquid opening was about 13 °.
In the third experiment, a liquid port plug was inserted into the liquid port of the lid part of the D26 size battery case prepared as the basis of the embodiment of the present invention so that the inclination with respect to the liquid port was maximized. Then, screw the male screw part of the liquid spigot into the female screw part of the liquid spout, and with the liquid spigot fully tightened, the protruding height from the top of the lid of each part of the head of the liquid spigot It was measured. In this case, the maximum inclination angle of the liquid stopper with respect to the liquid opening was about 5 °.

  The above first to third experiments were performed on three samples, respectively, and the results of measuring the maximum value and the minimum value of the protrusion height from the upper surface of the lid of each part of the head of the liquid spigot are shown in FIG. 11 shows. Also in FIG. 11, the results of the first to third experiments are indicated as “upright”, “conventional product”, and “invention product”, respectively, and the minimum value of the protrusion height is indicated by a white bar graph. The maximum value is shown as a bar graph with a diagonal line inside.

  From Example 1 and Example 2 above, it was confirmed that in the sample to which the present invention was applied, the inclination angle of the head of the liquid spout can be reduced by about twice that of the conventional product.

It is a longitudinal cross-sectional view which shows the structure of the principal part of the lead acid battery concerning embodiment of this invention. (A) is the front view which showed the liquid stopper used by this embodiment partially in cross section. (B) is the front view which showed a partial cross section of the modification of the liquid stopper used with the lead acid battery concerning this invention. It is the longitudinal cross-sectional view which showed the part of the liquid port of the cover part of the battery case of the lead acid battery concerning this embodiment, and the part of the liquid port stopper positioning part. It is the bottom view which looked at the principal part of the part shown by FIG. 3 from the downward direction. It is sectional drawing which showed the process in which a liquid stopper is attached to a liquid port in this embodiment. It is sectional drawing which showed the state which attached the liquid spout to the liquid port in this embodiment. It is the bottom view which looked at the principal part of the part shown by FIG. 6 from the downward direction. In other embodiment of this invention, it is sectional drawing which showed the state which attached the liquid stopper to the liquid port. It is the bottom view which looked at the principal part of the part shown by FIG. 8 from the downward direction. It is a graph which shows the experimental result which investigated the grade of the inclination of the liquid spout produced when a liquid spigot was attached to the liquid spout about a specific lead acid battery. It is a graph which shows the experimental result which investigated the grade of the inclination of the liquid spout produced when attaching a liquid spigot to a liquid spout about other specific lead acid batteries.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery case 2 Battery case main body 3 Cover part (electric case lid)
4 Cell chamber 5 Electrode plate group 6 Electrolyte 7 Liquid port 704 Female screw 8 Liquid port plug 801 Head 802 Tubular part 803 Male thread part 10 Cathode strap 11 Anode strap

Claims (3)

A battery case in which a group of electrode plates is housed together with an electrolyte, a liquid port having a female screw part on the inner periphery is formed in the lid, and a cylinder having a circular cross section extending downward from the head and the lower end of the head And a male screw part formed on the outer periphery of the upper part of the cylindrical part. The cylindrical part is inserted into the battery case through the liquid port, and the male screw part is the female screw part. In a lead-acid battery comprising a liquid spigot screwed to and attached to the lid of the battery case,
In the process in which the cylindrical portion of the liquid spigot is inserted into the battery case through the liquid port and the male screw portion is screwed to the female screw portion, the male screw portion is screwed with the female screw portion. Before reaching the position to start, so that the center axis of the male screw portion of the liquid port plug matches the central axis of the female screw portion of the liquid port. A lead-acid battery, wherein a liquid stopper positioning portion for positioning the liquid stopper is provided on the lower surface side of the lid. The liquid spout positioning part is composed of a pair of positioning pieces that are arranged so as to be opposed to the radial direction of the liquid spout and have an inner peripheral surface that fits to the outer periphery of the tubular part. The upper ends of the pair of positioning pieces are integrated with the periphery of the opening at the lower end of the liquid port,
The pair of positioning pieces are provided such that the lower ends of the pair of positioning pieces terminate at a position corresponding to the upper limit level of the electrolytic solution in the battery case, and the pair of positioning pieces are used for the electrolyte solution in the battery case. The lead acid battery according to claim 1, which also serves as an electrolyte surface level defining protrusion for defining an upper limit level.   The liquid spigot has a vent opening opened in a radial direction of the cylindrical portion at a lower end of the cylindrical portion, and a threaded engagement between the male screw portion of the liquid spout and the female screw portion of the liquid spout The pair of positioning pieces, the male screw portion, and the female screw portion are provided so that the vent hole of the liquid spigot is positioned between the pair of positioning pieces in a state in which The lead acid battery according to claim 2.

Images