CN101409332B - Sealed battery - Google Patents

Abstract

The present invention relates to sealed batteries, object to remove the fluctuation of the jogged state resulting from the dimensional tolerances of a liquid injection port (17) and a seal bolt (18) and to realize the sealability improvement of the liquid injection port (17) performed by the seal bolt (18). In this invention, the spreading and deformation of the shaft section(25) of the seal bolt (18) is performed by pressing an operation pin (29) in a function hole (30), so that the external circumstance surface of the shaft section (25) is pressed on the internal circumstance surface of a filling hole (19). Thus, the sealing-joining performance of the entire circumference scope between the external circumstance surface of the shaft section (25) and the internal circumstance surface of the filling hole (19) can be improved, so as to improve the sealability between the shaft section (25) of the seal bolt (18) and the filling hole (19) of the liquid injection port (17).

Description

sealed battery

technical field

The present invention relates to a sealed battery with a cover that blocks the opening of the battery case, a liquid injection port provided on the cover for injecting electrolyte solution, and a sealing plug installed in the liquid injection port, and relates to the realization of improving the injection rate obtained by the sealing plug. The technology of the sealing characteristics of the liquid port.

Background technique

In the sealed battery related to the present invention, the liquid injection port is formed in a stepped shape with a concave portion, and after the sealing plug having a head is attached to the liquid injection port, the outer peripheral edge of the head and the peripheral portion of the concave portion are welded. Thus, the liquid injection port is sealed, and a similar sealing structure can also be seen in, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-40690).

In this patent document 1, an injection hole is formed vertically through the cover that closes the upper surface of the opening of the battery case, and a circular recess with an upward receiving surface is formed around the injection hole as a liquid injection port. In addition, the sealing plug includes a shaft portion inserted into the injection hole from above, and a circular head portion protruding from the upper end of the shaft portion and received by the receiving surface of the concave portion. Then, after the sealing plug is installed in the concave portion, the outer peripheral edge of the head portion and the peripheral portion of the concave portion are irradiated with laser to melt them, thereby sealing the liquid injection port with the sealing plug.

The problem with the above-mentioned sealing structure is that due to the dimensional tolerance of the liquid injection port and the sealing plug, it is impossible to avoid changes in the fitting state such as "clearance fit" or "interference fit", and as a result, it becomes difficult to install the sealing plug at the liquid injection port. Difficulty, or poor welding occurs. That is, the filling port and the sealing plug are minute parts formed by press working, and a certain degree of fluctuation in part size, that is, dimensional tolerance is allowed. Therefore, when the inner diameter of the injection hole is the minimum value including the dimensional tolerance and the outer diameter of the shaft is the maximum value including the dimensional tolerance, there is a risk that the shaft cannot be inserted into the injection hole (interference fit).

Conversely, when the inner diameter of the injection hole is the maximum value including the dimensional tolerance, and the outer diameter of the shaft is the minimum value including the dimensional tolerance, there is a risk of the seal plug floating inside the liquid injection port in the mounted state ( gap fit). In this way, if the sealing plug floats in the installed state, the sealing plug is eccentric in the recess to cause an axial shift. As a result, poor welding occurs at the contact portion or gap between the recess and the sealing plug, and there is a risk of liquid leakage.

Contents of the invention

The present invention is made to solve the above problems, and its purpose is to eliminate fluctuations in the fitting state caused by dimensional tolerances of the filling port and the sealing plug, and to improve the sealing performance of the filling port by the sealing plug.

The sealed battery according to the present invention is characterized in that it has: a cover 5 for blocking the upper surface of the opening of the outer container 2, a liquid injection port 17 for injecting an electrolyte solution provided on the cover 5, and a metal material attached to the liquid injection port 17. Made sealing plug 18. The liquid injection port 17 has an injection hole 19 formed vertically through the cap 5 , and a circular recess 21 having an upward receiving surface formed around the injection hole 19 . The sealing plug 18 has a shaft portion 25 inserted into the injection hole 19 from above, and a circular head portion 26 protruding from the upper end of the shaft portion 25 and received by the receiving surface 20 of the concave portion 21. An operation hole 30 for expanding and deforming with an upper opening is recessed at the axial center position of the portion 25 . And, when the operation pin 29 is pressed into the operation hole 30 from the upper opening to expand and deform the shaft portion 25, the outer peripheral surface of the shaft portion 25 is pressed against the inner peripheral surface of the injection hole 19 in a tight state. In this close contact state, the liquid injection port 17 is sealed by welding the outer peripheral edge of the head portion 26 and the peripheral portion of the concave portion 21 .

A form in which a downwardly tapered pressed surface 33 is formed at the upper end of the operation hole 30 may be employed.

The maximum outer diameter dimension D1 of the shaft portion 25 including the dimensional tolerance is set to be smaller than the minimum inner diameter dimension D2 of the injection hole 19 including the dimensional tolerance, and the maximum outer diameter dimension D3 of the head portion 26 including the dimensional tolerance is set to be smaller than The minimum inner diameter dimension D4 of the above-mentioned concave portion 21 including dimensional tolerances is also small.

The present invention has the following effects.

According to the sealed battery of the present invention, by pressing the operation pin 29 into the operation hole 30, the shaft portion 25 of the sealing plug 18 is expanded and deformed, so that the outer peripheral surface of the shaft portion 25 is pressed against the inner peripheral surface of the injection hole 19. The shaft portion 25 is firmly attached to the injection hole 19 . Thus, the adhesiveness between the inner peripheral surface of the injection hole 19 and the outer peripheral surface of the shaft portion 25 can be improved, and the sealing performance between the shaft portion 25 of the sealing plug 18 and the injection hole 19 of the liquid injection port 17 can be improved. , Therefore, leakage from the liquid injection port 17 can be reliably prevented.

In particular, by expanding and deforming the shaft portion 25 to improve the adhesion between the shaft portion 25 and the injection hole 19, it is possible to absorb the dimensional tolerances of the sealing plug 18 and the liquid injection port 17 on the production side while reliably Seal the filling port 17. In other words, according to the present invention, the fluctuation of the fitting state between the shaft portion 25 and the liquid injection port 19 caused by dimensional tolerances in production can be eliminated, and the liquid injection port 19 can be reliably welded and fixed by the shaft portion 25, and it is possible to obtain A sealed battery with excellent reliability without leakage is excellent.

If the pressed surface 33 of lower narrow tapered shape is formed on the upper end portion of the operation hole 30, the pressed surface 33 can be used as a guide surface, and the operation pin 29 can be positioned at the axial center position of the shaft portion 25 reliably. Push-in operation of the operation pin 29. As a result, the shaft portion 25 can be expanded and deformed uniformly in the circumferential direction, so that the entire outer peripheral surface of the shaft portion 25 of the sealing plug 18 can be brought into uniform contact with the inner peripheral surface of the injection hole 19 of the liquid injection port 17 .

If the maximum outer diameter D1 of the shaft portion 25 including dimensional tolerances is set to be smaller than the minimum inner diameter D2 of the above-mentioned injection hole 19 including dimensional tolerances, it becomes a so-called "interference fit" state, and the sealing plug 18 does not exist. It cannot be installed on the liquid injection port 17. Therefore, after the sealing plug 18 is reliably dropped into the liquid injection port 17 to be in a temporarily fixed state, the expansion and deformation operation by the operation pin 29 is performed, followed by the welding operation, so that the sealing plug 18 can be reliably sealed. Mouth 17. It is excellent in that it is possible to suppress a drop in yield due to the inability to temporarily fix the seal plug 18 to the liquid injection port 17 and to improve productivity.

Description of drawings

Fig. 1 is a longitudinal sectional view of main parts of the sealed battery of the present invention.

Fig. 2 is an exploded perspective view of the sealed battery of the present invention.

Fig. 3 is a diagram for explaining the sealing structure of the sealed battery of the present invention.

Fig. 4 is a diagram for explaining the sealing procedure of the sealed battery of the present invention.

Fig. 5 is a diagram for explaining the sealing procedure of the sealed battery of the present invention.

In the picture:

1-sealed battery (dry battery), 2-outer can, 5-cover (sealing plate), 17-injection port, 18-sealing plug, 19-injection hole, 20-receiving surface, 21-recess, 25-shaft , 26-head, 29-operation pin, 30-operation hole, 33-pressed surface.

Detailed ways

1 to 5 show an embodiment in which the sealed battery of the present invention is applied to a dry battery constituting a battery portion. In Fig. 2, the plain battery 1 uses a flat cylindrical outer can 2 with an open upper surface as a base, houses an electrode body 3 and an electrolyte solution inside, and uses a plastic insulator 4 and a metal insulator 4 for the opening of the outer can 2. The sealing plate (cover) 5 is configured to be sealed. The two ends of the exterior can 2 and the sealing plate 5 are made into circles.

The electrode body 3 is wound in a spiral shape after stacking a positive electrode sheet with _LiCoO2 as an active material, a negative electrode sheet with graphite as an active material, and a separator for insulating these two sheets, and then presses the whole in a flat shape. formed flat. The conductive sheets 7 and 8 are drawn upward from the positive electrode sheet and the negative electrode sheet respectively. The electrolyte is prepared by melting LiPF ₅ in a solvent mixed with ethylene carbonate (EC) and methyl ethyl carbonate (MEC).

As shown in FIG. 1 , a negative terminal 9 is arranged at the center of the upper surface of the sealing plate 5 , and a positive terminal 10 also serves as the sealing plate 5 or the outer can 2 . The sealing plate 5 is composed of a stamped product made of aluminum or an aluminum alloy, and a circular terminal mounting hole through which the insulating seal 11 and the negative terminal 9 pass is provided in the center of the disk surface. On the upper surface of the sealing plate 5, a socket is formed by recessing around the terminal mounting hole. An insulating plate 12 is arranged on the inner side of the sealing plate 5 , and a metal pressure plate 13 is arranged on the lower side of the insulating plate 12 .

The outer can 2 is made of a deep-drawn product made of aluminum, aluminum alloy, or stainless steel, and the sealing plate 5 is fixed by laser welding while being fitted into the inner surface of the opening of the outer can 2 . The insulator 4 is a chassis-shaped plastic molded product, and cutouts 15, 15 for allowing the conductive sheets 7, 8 of the electrode body to be inserted are formed on the bottom to penetrate up and down.

In FIG. 1 , one end side of the sealing plate 5 in the left-right direction is provided with an explosion-proof opening (crack vent) 16 , and the other end side of the sealing plate 5 is provided with a liquid injection port 17 for injecting the electrolyte. The opening 16 ruptures when the internal pressure of the outer can 2 exceeds a certain value, and releases the gas in the outer can 2 . After the electrolyte is injected, the liquid injection port 17 is sealed by a sealing plug 18 .

As shown in FIG. 3 , the liquid injection port 17 is formed by an injection hole 19 formed in the sealing plate 5 penetrating up and down and a circular concave portion 21 having an upward receiving surface 20 formed around the injection hole 19 . Stepped. The injection hole 19 is formed in a linear shape with a uniform inner diameter in the vertical direction. Likewise, the concave portion 21 is formed in a linear shape with a uniform inner diameter in the range in the vertical direction.

The sealing plug 18 that seals the liquid injection port 17 is made of metal such as aluminum, and has a shaft portion 25 inserted into the injection hole 19 from above, and a concave portion 21 protruding from the upper end of the shaft portion 25 . The circular head 26 received by the receiving surface 20 . The downward locking of the sealing plate 5 by the sealing plug 18 is achieved by fitting and receiving the head portion in the recessed portion 21 .

The shaft portion 25 includes a linear portion 27 with a uniform outer diameter in the vertical direction, and a lower tapered guide portion 28 provided at the lower end of the linear portion 27 and whose diameter gradually decreases downward. The thickness 50 of the linear portion 27 is 0.1 mm or more, and the thickness from the bottom to the tip of the small diameter portion 31 of the sealing plug 18 is 0.1 mm or more.

An operation hole 30 is recessed at the axial center position of the shaft portion 25 , and the shaft portion 25 is expanded and deformed when the operation pin 29 is pushed in from above. The operation hole 30 includes: a lower small-diameter portion 31 with a uniform inner diameter, a large-diameter portion 32 having a larger inner diameter than the small-diameter portion 31 , and a narrow tapered lower portion provided on the upper end of the small-diameter portion 31 and pressed by the operating pin 29 . The pressed surface 33 of. At the lower end of the operation pin 29, a downward tapered pressing surface 34 is formed.

As shown in FIG. 3 , the maximum outer diameter dimension D1 of the straight portion 27 of the shaft portion 25 including the dimensional tolerance is set smaller than the minimum inner diameter dimension D2 of the injection hole 19 including the dimensional tolerance. Furthermore, the maximum outer diameter dimension D3 of the head portion including the dimensional tolerance is set to be smaller than the minimum inner diameter dimension D4 of the concave portion including the dimensional tolerance. Therefore, when the sealing plug 18 is dropped into the liquid injection port 17 from above, the shaft portion 25 and the head portion 26 will not be stuck in the injection hole 19 and the concave portion 21 of the liquid injection port 17, and it can be made as shown in FIG. 4 . temporary fixation status.

Next, the sealing operation of the liquid injection port 17 after the electrolytic solution is injected will be described with reference to FIGS. 4 and 5 . First, as shown in FIG. 4 , the sealing plug 18 is dropped from above the liquid injection port 17 to be temporarily fixed. As mentioned above, since the liquid injection port 17 and the sealing plug 18 satisfy the relationship of D1<D2, D3<D4, between the outer peripheral surface of the shaft portion 25 and the inner peripheral surface of the injection hole 19 and the outer peripheral surface of the head 26 A slight gap is formed with the peripheral side surface of the concave portion 21 . Moreover, although it has been repeatedly described, since the relationship of D1<D2 and D3<D4 is satisfied, when the sealing plug 18 is dropped into the liquid injection port 17 from above, the shaft portion 25 and the head portion 26 will not be stuck in the injection hole 19 and the injection port 17. On the concave portion 21, the temporarily fixed state as shown in FIG. 4 can be made smoothly.

Then, as shown in FIG. 5 , the operation pin 29 is press-fitted into the small-diameter portion 31 of the operation hole 30 from the upper opening to expand and deform the shaft portion 25 . Thereby, a close contact state can be achieved in which the outer peripheral surface of the straight portion 27 of the shaft portion 25 is pressed against the inner peripheral surface of the injection hole 19 . In other words, by expanding and deforming the shaft portion 25 , the gap between the outer peripheral surface of the shaft portion 25 and the inner peripheral surface of the injection hole 19 can be filled and the shaft portion 25 and the injection hole 19 can be brought into close contact. During the pressing operation of the operation pin 29 as described above, the outer diameter dimension of the head portion 26 hardly changes.

From this close contact state, as shown in FIG. 1 , laser welding is performed from above on the boundary portion between the outer peripheral edge of the head portion 26 and the peripheral portion of the recessed portion 21 . This welding operation is carried out over the entire outer peripheral edge of the head 26, whereby the filling port 17 can be completely sealed. In the welding work described above, the welding work is performed so as to fill a slight gap between the outer peripheral edge of the head portion 26 and the peripheral portion of the concave portion 21 . In FIG. 1 , reference numeral 40 indicates a weld by laser welding.

As described above, in the sealing structure of the liquid injection port 17 in this embodiment, the operation pin 29 is press-fitted into the operation hole 30, and the shaft portion 25 of the sealing plug 18 is expanded and deformed, thereby pressing the outer peripheral surface of the shaft portion 25 against the sealing structure. On the inner peripheral surface of the injection hole 19 , the shaft portion 25 can be firmly attached to the injection hole 19 .

As a result, the adhesion between the inner peripheral surface of the injection hole 19 and the outer peripheral surface of the shaft portion 25 can be improved over the entire circumference, so that the injection hole between the shaft portion 25 of the sealing plug 18 and the injection port 17 can be realized. 19 improved sealing. Therefore, the liquid leakage from the liquid injection port 17 can be reliably prevented, and the reliability of the dry battery 1 can be improved.

Moreover, since the welding operation can be performed with a slight gap formed between the head portion 26 of the sealing plug 18 and the concave portion 21 of the liquid injection port 17, even the electrolyte remaining on the receiving surface 20 during the welding operation or the like When vaporized to generate gas, it can be leaked through the gap. In this way, if the residual electrolyte solution on the receiving surface 20 can be removed, it is possible to eliminate the inconvenience that the sealing plug 18 falls off due to the gasification pressure of the residual electrolyte solution after the welding operation.

In particular, by expanding and deforming the shaft portion 25, the adhesion between the shaft portion 25 and the injection hole 19 can be improved, so while absorbing the dimensional tolerances of the sealing plug 18 and the liquid injection port 17 in manufacture, The liquid injection port 17 is securely sealed. In other words, according to this sealing structure, fluctuations in the fitting state between the sealing plug 18 and the liquid injection port 17 caused by dimensional errors in production can be eliminated, and the liquid injection port 17 can be securely welded and fixed by the sealing plug 18, enabling It is very good in that a sealed battery with excellent reliability and no liquid leakage can be reliably obtained.

If the pressed surface 33 of lower narrow tapered shape is formed on the upper end portion of the operation hole 30, the pressed surface 33 can be used as a guide surface, and the operation pin 29 can be positioned at the axial center position of the shaft portion 25 reliably. Push-in operation of the operation pin 29. As a result, the shaft portion 25 can be expanded and deformed uniformly in the circumferential direction, so that the entire outer peripheral surface of the shaft portion 25 of the sealing plug 18 can be brought into uniform contact with the inner peripheral surface of the injection hole 19 of the liquid injection port 17 .

If the maximum outer diameter dimension D1 of the shaft portion 25 including the dimensional tolerance is set to be smaller than the minimum inner diameter dimension D2 of the injection hole 19 including the dimensional tolerance, the maximum outer diameter dimension D3 of the head portion 26 including the dimensional tolerance is set as If it is smaller than the minimum inner diameter D4 of the concave portion 21 including dimensional tolerances, it becomes a so-called “interference fit” state, and there is no case where the sealing plug 18 cannot be installed in the liquid injection port 17 . Therefore, after the sealing plug 18 is reliably dropped into the liquid injection port 17 to become a temporarily fixed state, the expansion and deformation operation performed by the operation pin 29 is performed, and then the welding operation is performed, so that the injection port can be reliably sealed with the sealing plug 18 . Liquid port 17. It is very good in that it is possible to suppress a drop in yield due to the inability to temporarily fix the seal plug 18 to the liquid injection port 17 and to improve productivity.

Claims (3)

1. a sealed cell is characterized in that,

Have lid above the opening of blocking outer tinning, be located at the above-mentioned electrolyte that covers and inject the liquid injection port of usefulness and be installed in metal sealing bolt on this liquid injection port,

Above-mentioned liquid injection port has: be formed at the hand-hole of above-mentioned lid to connect shape up and down; With recess with the round shape that is formed at this hand-hole bearing plane up on every side,

Above-mentioned sealing bolt has the axial region that is inserted into from the top the above-mentioned hand-hole and the head of the circle that forms in the upper end of this axial region with stretching out and born by the bearing plane of above-mentioned recess, the shaft core position of above-mentioned axial region form recessedly have above the handle hole used of the expansion deformation of opening

Constitute if from the top opening operative pin is pressed into and makes above-mentioned axial region expansion deformation the aforesaid operations hole, the outer peripheral face that then becomes this axial region is by the state that is adjacent on the inner peripheral surface that is pressed in above-mentioned hand-hole,

Under this is adjacent to state, thereby the neighboring by welding above-mentioned head and the periphery of above-mentioned recess are sealed above-mentioned liquid injection port.

2. sealed cell according to claim 1 is characterized in that,

Be formed with the face that is pressed of narrow taper down in the upper end in aforesaid operations hole.

3. sealed cell according to claim 1 and 2 is characterized in that,

The maximum outside diameter size that comprises the axial region of dimensional tolerance is set at also littler than the minimum diameter size of the above-mentioned hand-hole that comprises dimensional tolerance,

The maximum outside diameter size that comprises the head of dimensional tolerance is set at also littler than the minimum diameter size of the above-mentioned recess that comprises dimensional tolerance.

Images