DE2109499B2 - Securing electric battery lids - by welding - Google Patents

Abstract

Battery boxy and recessed lid are secured by positioning box and lid with opposed dies and putting a heater in between to contact an internal shoulder on the lid, the heater being recessed so that id does not contact the wall of the lid adjacent the shoulder. Pref. the wall forms with the upper tapered portion of the box wall a tapered recess into which molten material flow when the lid and box are pressed together after the heating. Polypropylene is pref.

Description

The invention relates to a device for connecting the box of a block battery with a cover, which has an outer, vertical edge that overlaps the upper edge of the box.

From DE-OS 14 96 221 a box according to the preamble of claim 1 is known. With this one known box is in a circumferential gap between the lid and box adhesive for attachment brought in. This is relatively laborious and tedious. In terms of production, it is cheaper To fix the lid and box to one another by the mirror welding process. This procedure is from the FR-PS 14 76 366 known and in boxes with lids that have vertical walls, not applicable because only the lower edges of the vertical walls could be reached through the heating plate.

The object of the invention is to provide a device of To improve the type mentioned in such a way that in a block battery with a vertical edge having Deekel the mirror welding process is applicable.

This object is achieved according to the invention by a heating plate for carrying out the mirror welding process, the one with the side facing the cover can be inserted into these and undercut at the edges.

Advantageous embodiments of the invention are shown in

listed in the subclaims

Embodiments of the invention are shown in the drawings and are described below described in more detail. It shows

F i g. 1 shows a partial section through the battery box, the production of the connection between the individual cells is shown,

F i g. 2 is a plan view from below of the battery cover,

ίο F i g. 3 shows a section on the line AA in FIG. 2,

F i g. 4 is a partial schematic representation of a device that is used to cover the lid with the To weld the battery box, F i g. 5 a partial Latin representation of the heating system, those used in the device shown in Figure 4 will,

6 shows a partial sectional view of the in FIG shown heater,

F i g. 7 shows a detail in section through the Battery cover on the line BB in Fig.2 and through

part of the heating in a phase during the

Manufacture of the battery using the in F i g. 4 shown and F i g. 8 a detail in section through the Battery cover and heater in the same Manufacturing phase of the battery, which is shown in FIG. 7 is shown

with a heating variant compared to that in Fig. 7 shown.

According to the illustration in FIG. 1 is a battery pack

Most Il made of polypropylene or another suitable thermoplastic material The Box has partitions 12 which divide the box into six compartments. Each subject takes one prefabricated set 13 of plus or minus plates and -separators on. The two groups of plates in each of the four sets in the middle compartments of box 11 are used, are each connected to conductive connecting tabs 15,16 with extensions are provided, which are in the installed state in extend essentially parallel to the partition walls 12. The extensions on the tabs tS and 16 are each provided with an upright, annular rib 10 on their rims, which are provided for the position in the direction of the partition walls 12, and the extensions of the tabs 16 are respectively also on the side which is provided for the position in the direction of the respective partition wall, with a outwardly extending pin 16a. The sentences that are to be inserted into the ends Compartments are provided each have a group of panels that are connected with a tab 15 or 16, while the other group of plates are each connected to the terminal bolts 17 of the battery.

In the partition walls 12 holes are punched and

such an arrangement is provided that with in the box II inserted plate sets of the respective pin 16a through a hole in a respective Partition goes and engages the tab 15 on a set in the adjacent cell. The ribs 10 am respective pin 16a and the respective tab 15 surround the hole in the respective wall, the Walls 12 are, of course, provided with sufficient flexibility to permit insertion of the plate sets into the compartments allow before the pin 16a in the respective Get holes. If all the sentences are in the intended Sit down, make the necessary connections between each cell using a Tool 18 produced, as shown in FIG. 3 is shown.

This tool has two electrodes 21, 22 which act on corresponding tabs 15 and 16, respectively simultaneously exert pressure and allow current to flow between the tabs 15 and 16, so that the pin 16a is welded to the respective tab 16 with the corresponding tab 15 and the hole in the respective partition 12 is sealed. When all connections are made between the individual cells the battery is ready, apart from the lid.

The periphery of the open end of the box 11 and the free edges of the partition walls 12 lie in the same plane, and at the open end of the box 11 is it is provided with an outwardly extending peripheral shoulder 23. The outside of the wall of the Box 11 between the shoulder 23 and the open end of the box 11 is inclined inwardly so that the Dimensions of the open e'jides of the box 11 are smaller than the dimensions of the box at shoulder 23. Also at the closed end are the larger ones Walls of the box 11 are each provided with recesses 24, with clamping means (not shown) in the Use to engage the recesses 24 to keep the battery in its intended position in a vehicle to keep.

The cover 25 (Fig. 2 and 3) is also off Polypropylene or another suitable thermoplastic material and has a peripheral Wall 26 which extends substantially at right angles to the plane of the cover 25. Further belongs to the lid an inner peripheral shoulder 27. on which the free end of the wall of the box 11 engages, when the lid 25 is in the intended position in which the box 11 is closed. In addition, the cover is provided with partition walls 28, which are placed on the box 11 when The cover rest against the free edges of the partitions 12 of the box 11. The walls 28 of the lid are thicker than the walls 12 of the box U to ensure that there is surface contact between the free edges of the walls 12 and the walls 28 takes place. The cover 25 has six integrally formed Filler neck 29, each of which has a ventilation channel

31 is assigned to the respective nozzle 29 and the respective ventilation duct 31 are each assigned to a corresponding cell of the battery when the Lid 25 is placed on box 11. In the finished state, the cover 25 is a collecting line assigned to the cover 25 opposite between a first position in which the vents 31 open are, and is movable to a second position in which the vents 31 are closed. The vents 31 and the nozzles 29 open into a common channel

32 in the cover 25. Fter channel 32 and the collecting line (not shown) facilitate a simultaneous filling of the six cells of the battery with electrolyte to the desired level. The cover 25 also has two hollow pegs 33 which are integrally attached and which receive connection inserts for the pole bolts 17. At the opposite ends, the cover 25 has two integrally formed !: fitting nipples 30, which protrude from the underside of the cover 25 and point with an inclined surface to the peripheral wall 26, the inclined surface from the shoulder 27 in a direction away from the wall 26 When the lid 25 is placed on the box 11, the nipples 30 guide the lid into the correct longitudinal position relative to the box 11. Further fitting nipples (not shown) can also be provided on the partition walls 28 of the lid. The other fitting nipples are then provided in pairs on the respective partition wall 28 and serve to guide the walls 28 in contact with the associated walls 12 when the lid is placed on the box ί 1. The lid 25 is welded to the box 11, and for this purpose is with the in F i g. The device has a housing with a base 34, two posts 35 and an arm 36 which extends at right angles to the posts 35 and lies above the base 34. A first die part 37 is slidably seated on the arm 36 for execution vertical movement opposite the arm 36. The die part 37 sits on two guide rods, one of which is shown at 38, and is moved vertically with respect to the arm 36 by a compressed air or hydraulic ram 39. A conveyor (not shown) extends over the base 34, and a work table 41 belongs to the base 34 , which can be moved vertically upwards opposite the base 34 from a position in which the work table is slightly below the level of the conveyor. When in operation, the die 37 carries a battery cover! 25, and the work table 41 carries a battery box 11 to which the cover 25 is to be welded. Between the arm 36 and the base 34, the uprights 35 carry two guide rings, one of which is shown at 42. The guides 42 extend parallel to the arm 36 and to the base 34. A heater 43 is slidably mounted on the guides 42 and can be moved along the guide 42 with the aid of a compressed air press (not shown), see FIG. 4, 5 and 6. The heater 43 has a main body 44 which carries rollers 45 by means of which the heater is slidably mounted on the guides 42. The body 44 is provided with passages 46 within which the electrical heating elements sit. A simple dural plate 47 is attached to the side of the body 44 facing the base 34 and two dural plates 48a and 486, which are mirror images of each other, are attached to the side of the body 44 facing the arm 36. The plates 48a and 4Sb are fastened to the body 44 by means of screws, which can be constructed, and are separated from one another by a dural packing piece 48c. The plates 48a and 48b and the packing gap 48c form a subassembly which, on the side facing the battery cover 25, has essentially the same size as the internal dimensions of the battery cover 25. The periphery of the subassembly formed by panels 48a and 486 and piece 48c is, however, undercut as shown at 49 so that the dimensions of the subassembly are of greatest value on the side facing lid 25 , decrease to a minimum value on the side that is on the K / 'tper 44. Furthermore, the plates 48a and 4Sb are provided with holes 51 in which the filler necks 29, the fitting nipples 30 and the connecting pins 33 of the cover 25 are received when the cover 25 comes into contact with the heater 42. Preferably, the dural used in heating has the following composition:

J. 5 to 4% copper
0.4 to 0.7% magnesium
0.4 to 0.7% manganese
up to 0.7% silicon
Rest of aluminum

The sequence of operations when welding the box 11 to the cover 25 is as follows:

A row of boxes containing the cell sets 13 connected to one another and on each of which lids 25 are placed are placed on the conveyor and individually guided over the work table 41 by the conveyor between guide rails 53. When a box 11 arrives at the work table 41, it comes into contact with a stop 52, which is seated on the stands 35, and a microswitch is thereby switched, which switches on a cam control. The cam control first causes the working table 41 to be raised by the moving conveyor in order to carry the box 11 and bring it into the intended position. Mechanical means (not shown) are then operated to hold the box 11 firmly in the intended position on the worktable 41 for the remainder of the work cycle. The cam control then causes the die part 37 to be lowered until the die part 37 engages the cover 25, which sits on top of the box 11. When the die part 37 engages the cover 25, the movement of the die part 37 and the work table 41 is stopped, and gripping means on the part 37 are operated such that the cover 25 is gripped by the die part 37. The die part 37 is then moved back into its starting position, so that the cover 25 is lifted off the box 11. In addition, the work table 41 is lowered to a position slightly above the moving conveyor. The heater 43 is now moved along the guides 42 until it assumes a position between the box 11 and the cover 25. The heater 43 is kept in the heated state so that the plates 48a and 4Sb. the packing piece 48c and the plate 47 all have a temperature of 380 ⁰ C. The die 37 is then lowered so that the plates 48a and 486 and the packing piece 48c engage the lid 25 and contact the peripheral shoulder 27 and the free edges of the walls 28 of the lid. One second after the lid 25 is placed on the heater, the work table 41 is raised so that the free edge of the wall of the box 11 and the free edges of the partitions 12 of the box 11 engage the plate 47 of the heater 43. The lid 25 and the box 11 are then held in contact with the heater for a further three seconds, so that the free edges of the wall of the box 11 and the partition walls 12 are heated for three seconds, while the shoulder 27 and the free edges of the partition walls 28 heated for a total of four seconds. The box 11 and the lid 25 are easily printed in contact with the heater 43. Since the assembly formed by the plates 48a and 486 and the packing piece 48c is undercut at 49 (FIG. 10), the wall 28 of the cover 25 is not heated.

The die part 37 and the work table 41 are then returned to their previous positions, and the heater 43 is moved back from the position between the cover 25 and the box 11. When the heater 43 is completely retracted, the work table 4t and the die part 37 are moved towards one another in order to bring the cover 25 into contact with the box 11. The time that elapses before the cover 25 and the box 11 are lifted off the heater 43 and contact each other is about one and a half seconds. The lid is then pressed firmly against the box 11 for four seconds, during which time the areas of the box 11 and lid 25 which have been melted by contact with the heater 43 flow into one another to weld the lid to the box. After the lid has been held in contact with the box for four seconds, the lid is released from the die 37 and the worktable 41 is lowered so that the box 11, together with the lid 25 welded thereto, returns to the conveyor and be replaced by a further box 11 and a corresponding cover which is to be welded to the box

to the die part 37 moved back to its starting position in preparation for a subsequent work cycle. The total working cycle of the device takes 12 seconds.

It has been found that battery packs with partitions that are less than 2 mm thick and one Have a length of more than 150 mm, on the partitions both during the application of pressure between the Box and heater to melt the required areas of the box as well as during the Applying pressure between the box and the lid to weld the lid to the box tend to bend. In order to eliminate this problem, a lower pressure is used in order to remove the To press the box in contact with the heater and thereby cause the first melting step. In In one embodiment, the box is pressed against the heater 39 with a pressure of 2.74 bar, while the cover 25 is pressed against the heater 39 with a pressure of 5.63 bar. It goes without saying

jo here that the same pressure, usually 5, b4 bar, is used in a normal battery box, to press both the lid and the box against the heater. To a welding of the lid to effect with such a battery box is carried out after the first melting step, the exercise of Pressure between the lid and box preferably in two stages, i.e. H. through initial exercise only a low pressure and then by increasing the pressure to the setpoint. In a special Embodiment, the cover 25 is against the box 11 with an initial pressure of 2.11 bar pressed, and the pressure is then increased to a final value of 5.63 bar, the duration of the pressing is set accordingly. It has also been found that the provision of the fitting nipple 30 to the Ends of the lid 25 leads to the fact that the free edges of the end walls of the battery box II on a Flexing inward against their cell compartments while exercising? of pressure between the lid and the

so caste are prevented. If further guide nipples are provided on the partition walls 28 of the cover are, these also lead during the welding to the free edges of the walls 28 and the To keep walls 12 in flat contact with one another.

in Fig. 8 shows a variant of the device described above. The structure of the heating sub-assembly, which is formed by the plates 48a and 48b and the packing piece 48c , is different.

Although the subassembly is undercut toward the rear of the surface facing toward the battery cover 25, the periphery 54 of the subassembly defines first and second surfaces 54a and 54ft, respectively. The first surface 54a of the periphery 54 extends at right angles to the surface of the subassembly. which points in the direction of the cover 25, and the second surface 54έ> extends from the surface 54a to the surface of the subassembly in connection with the body 44, and they

if compared to the first peripheral flat i4, i is inclined inwards so that there is a clic liner incision of the substructure group, it is of course possible that. as in the previously described exercise theory. only the filters 27 of the lid 25 and the free children of the Waride 28 through the substructure; are heated, which is formed by the plates 48; i and 48fr and tlas I ··: ktingsslück 48c. if the lid is attached to the llci / ung. By providing the periphery 54 of the Unlerbaugruppi: but in / white sections, as has been described ι-ι, a more precise control of the waruiing of the shoulder 27 can be achieved than is possible. if only one line is used, as described: · in the first example of execution. ι where the periphery of the subassembly. which is formed by the l'l.ilts 48, / and 48 /) and by the packing piece 48c. al'ein with the llinlersclineiclung isi.

When the box and the lid are removed, i "volatilizes on ilen PIa ¹ Ic-Ii 47, 48, 48Λ and on the packing piece 48t ¹ ! Lallendes polypropylene from the cover and from Box. When the plates are ready for a subsequent operation The nipple formed by the plates 48, / and 48 / 'and the package piece 4Hc can of course also consist of a single part, in practice the liaugriippc but provided in three parts, so that the assembly formed by the parts 48; i, 48 /) and 48c can be set up to accommodate an area of differently sized storage lids by inserting the packing gap 48c through other dural packing gaps of other widths .

Di the outer wall of the free lindes of the box 11 is inclined inwards, a wedge-shaped gap / wipe the wall of the box II and the wall 2h of the lid 25 is formed when the lid 25 rests on it Il ^l united, is welded to the lid 25 with the box Il / ii, may molten Pol \ piop \ LCN \ om box and \ om lid into the wedge-shaped gap welcomed, as well as inwards in the acher I of the battery. It was found that the wedge-shaped gap favors the heating / wiping of the lid and the box. When the lid 25 is printed in abutment with the box II, the melted parts of the box II and the lid 25 become veiTornil. until the free! - "title of the wall 2h of the cover 25 rests on the shoulder 21 of the box 11. The wall 26 and the shoulder 2} thus serve to fix the cover 25 against the box 11 and thus contribute to the production of reproducible welds in satisfactory execution.

In addition 5 sheets of drawings

Claims (6)

Patent claims: 1. Device for connecting the box of a block battery with a cover that has an outer, has vertical edge that overlaps the upper edge of the box, characterized by a Heating plate (43) for carrying out the mirror welding process, which is connected to the cover (25) facing side can be inserted into these and undercut at the edges (49). 2. Device according to claim 2, characterized in that the undercut part (48a, 486, 4Sc) of the heating plate (43) is attached to a heating element (44) 3. Apparatus according to claim 1 or 2, characterized in that the plate made of an aluminum alloy with 3 ^ to 4% Cu, 0.4 to 0.7% Mn, 0.4 to 0.7% Mg and up to 0.7% Si 4. Device according to one of claims 1 to 3, characterized in that the undercut part (4SiL 48Zj ₁ 48c) of the heating plate (43) consists of several parts which are releasably attached to the heating element (44) and of which at least a part. (4Sc) can be exchanged for another part with different dimensions 5. Device according to one of claims 1 to 4, characterized in that the heating plate (43) on the side opposite the side with the undercut part (48a, 4Sb, 4Sc) has a further plate-shaped part (47) which can be placed against the edge of the open end of the battery box (II) and heats it. 6. Cover for Vt.rschwe-.3en by a device according to any one of claims 1 to 5, characterized characterized in that this i <: en has a shoulder (27) to which the undercut edge of the Heating plate (43) can be applied.