SE415716B - Arrangement for application of a paste to a bandlike workpiece to produce sintered electrodes for alkaline batteries - Google Patents

Abstract

The invention concerns an arrangement for application of a paste to a bandlike workpiece to make sintered electrodes for alkaline batteries, which arrangement comprises a feed tank filled with paste, through which the bandlike workpiece is designed to be pulled during passage through a slot to produce a paste layer of predetermined thickness on either side of the workpiece, which pulling slot is configured with a projection for centring of the workpiece in the slot, and characterised in that the tank consists of bunkers 1 situated on either side of the workpiece 5, whose side walls facing each other are configured at the bottom with a windowlike opening 7 for dispensing of paste to the workpiece 5 during its passage between the bunkers 1, and which are pivoted to press against each other with their lower parts with the centring projection 8 adjacent to same, and the pulling slot is formed by the upper edges of the openings 7. <IMAGE>

Description

vsoovzz-l N calibration drive disc arranged. The strip-shaped blank moves through the slot of the drawing disc and pulls the paste with it from the feed container, at the same time as the excess paste is removed from the strip by the calibration edges of the drawing disc. At the inside of the slot of the drawing plate, guide projections are arranged against each other, which are located at equal distances from each other and directed along the path of movement of the blank when applying the paste. The width of the gap between the opposite projections is equal to the thickness of the substance to be coated with the paste. This slot is intended for centering the blank in the slot of the draw disc.

In addition, it is known that in factories belonging to the French company "Saft", which is a leading company in the field of production of accumulators with coated sintered electrodes, pastes are applied to strip-shaped substances by means of identical devices, which include a co-paste question filled with feeds. - container, through which a strip-shaped substance is drawn, and a so-called calibration nozzle, which is intended to give the substance coated with the paste a predetermined thickness.

These known devices have the following disadvantages. .

When the paste is applied to the strip-shaped blank by means of these known applicators, the blank is drawn through the paste in the direction from the bottom upwards, at the same time as it pulls the paste due to the paste being viscous, so the desired filling of the holes in the blank with paste cannot be guaranteed. means that the applied layer of paste on the substance does not get the desired quality.

In addition, in its known devices, the paste is applied to the strip-shaped blank over the entire width of the blank. After the electrodes have been punched out of the strip-shaped blank, the paste coating is sanded off by hand from the parts of the electrodes which are intended for connection of current-dissipating means.

The centering projections on the traction sheave which are directed along the path of movement of the blank during the application of the paste leave clear traces in the applied layer, which grooves cause cracking after completion of sintering. In addition, when applying the paste to a blank with a double-sided perforation which has row-like degrees which are directed in both directions from the blank, the centering 790U '? 32'4 projections which are directed along the path of movement of the blank at on the application of the paste, not the desired positional accuracy of the blank in the middle part of the applied layer due to the protrusions ending up locally in the spaces between the rows of degrees, whereby the applied layer acquires local non-uniformities and irregularities, which on sintering leads to deformation And cracking in the finished electrodes.

An object of the present invention is to eliminate these disadvantages.

The main object of the invention is to provide a device for applying a paste on very thin strip-shaped blanks to sintered electrodes for alkaline accumulators, which device makes it possible to increase the application efficiency and to improve the quality of sintered electrodes which are punched out of the coated and sintered strip-shaped blanks, by changing the construction of the feed hopper and centering draw plate.

This is achieved by means of a device according to the present invention, in that the container consists of pockets located on each side of the blank, whose side walls facing each other are formed at their lower part with a window-like opening for discharging the paste to the blank during its passage between the pockets and which are pivotally suspended for pressing against each other with their lower parts with the centering projections abutting against it, the tension gap being formed by the upper edges of the openings.

It is suitable that the flaps with springs are arranged at Bid0WïÉ @ Pna of the openings in each pocket, which springs are intended to press the end surface of each flap against the blank in order to limit the width of the part of the blank coated with paste, and that each opening failed is sealed by means of an elastic film, the free end of which together with the blank is inserted into the space between the pockets and arranged to be pressed against the blank by the pressure of the paste.

It is furthermore suitable that calibration plates are inclined along the upper edge of the opening of each pocket and connected to a holder or comb supporting a centering projection by means of screws for adjusting the thickness of the layer to be applied. 790Û732-lf It is furthermore suitable that the operative ends of the centering spout projections, which lie in the application plane, are directed obliquely 30-H00 towards the vertical axis of the drawbar, and that the calibration plates at their lower edge surface are provided with a chamfer which forms a cavity. for a paste volume sufficient to fill the traces left by the centering projections in the applied layer.

The proposed device makes it possible to increase the application efficiency by applying the strip-shaped substance paste from the underlying layers, which are pressed against the strip by the hydrostatic pressure from the paste column in the container, thereby preventing the applied layer from being brought into contact with the upper layers. , more liquid layers of the paste in the container, aa the paste ekiktee, een a fills the holes in the blank faster with the paste, which increases the speed of movement of the blank and consequently the efficiency of the device.

Because the food container is built in the form of soap separate pockets, which can easily be exchanged for pockets with openings with other dimensions (eg other width) without the device having to be stopped and without any breakage of the blank, the proposed device can effectively used in the production of electrodes in small series.

The food container so designed makes it possible to reduce the resistance to the movement of the substance between the pockets to a minimum, whereby the paste can be applied to very thin substances with a thickness of 20-50 / am. By arranging at the side edges of the opening of each pocket a flap with a spring which is intended to press the end surface of each flap against the blank, a clear boundary is obtained between the applied layer and the uncoated surfaces for connection of a current-dissipating member after punching the electrodes out of the blank, whereby the pockets can be designed so that they are suitable for applying the paste to blanks with an uncoated surface lying both along the edge of the blank and in its middle part, if the openings of the pockets are separated from each other by a partition with flaps . The pockets, which by means of axle pins are suspended on parallel bars, can in this case be moved automatically in the plane of the blank perpendicular to its direction of movement, for example by means of known automatic control systems, whereby the desired position accuracy of the applied layer relative to the perforation border at an unavoidable försfkåutflínå a? the substance, especially for very thin substances, is ensured.

The holders or combs with their centering projections, preferably in the form of plate-shaped teeth and calibration plates, which are inclined along the upper edge of the opening of each pocket, help to increase the control accuracy of the thickness of the applied layer. If the calibration plate is inclined 300, for example, towards the vertical, its movement causes a distance of 1 mm during the adjustment that the gap width changes 0.5 mm.

By tilting the active end surfaces of the centering projections of the holder or comb towards the path of movement of the blank and by chamfering the lower edge surface of the calibration plate, the blank can be carefully centered in the applied layer and the traces left by the centering projections in the blank can be eliminated. cracking and deformation of the substance during sintering, thereby improving the quality of the coated sintered electrodes for alkaline accumulators.

The invention is described in more detail below with reference to the accompanying drawing, in which Fig. 1 shows a side view of a device according to the present invention for applying a paste on a strip-shaped blank to sintered electrodes for alkaline accumulators, Fig. 2 shows a section through a pocket, Fig. 3 shows a view of a blank seen from the blank, Fig. U shows a drawing disc in section, and Fig. 5 shows a drawing disc seen from the blank.

The proposed device for applying a paste to a strip-shaped blank for metal-ceramic electrodes for alkaline accumulators comprises a feed container, which is constructed in the form of two separate pockets 1 (Figs. 1, 2), which are suspended on parallel rods 2 in shaft pins 3, which are attached to the upper part of the pockets.

At the lower part, the pockets 1 are arranged to be pressed from both sides against a strip-shaped blank 5 by means of springs H, which blank is applied during application between the pockets 1. The blank 5, which is unwound from a blank spool (not shown in the drawing), is passed via a roller 6, which is arranged under the pockets for guiding the blank 5 vertically upwards through the device and into an oven for drying and sintering the blank coated with the paste, which is then fed to a receiving coil (not shown in the drawing) with a drive device which pulls the blank through 79007324: - 5 f ~ a @ m__a fl i-h ..iel, ii_q the whole plant.

Each pocket 1 (Figs. 2, 3), lower part is provided with a rectangular opening 7, which is received in the side walls of the pockets 1 and is intended for supplying paste to the blank É, when the blank is pulled between the pockets 1.

At the side edges of the openings 7, flaps 9 (fig. 3) are arranged in grooves with springs 10, which are intended to push the flaps 9 out of the grooves and to press its end surfaces against the blank 5 when applying the paste. The flaps 9 and the springs 10 are at both sides threaded on a rod 11, which is attached to strips 12 and arranged along the bottom edge of each pocket. In the middle part of the rod 11, an elastic film 13 is wound into a roll, the free end of which is inserted into the opening 7 in each pocket 1 and is intended to seal the lower gap between the pockets 1 during the application of the paste.

Arranged along the upper edges of the openings 7 are inclined holders or combs lä (Figs. 2, 5, U) with centering projections 8, preferably in the form of plate-shaped teeth. When the centering projections 8 abut against the blank, the upper edges of the openings 7 form a tension plate (tension gap). The holder or chamber 14, which is arranged along the upper edge of each opening 7 and slopes towards the plane of the opening 7, is provided with calibration plates 15, which are connected to the holder or cam by means of screws 16 (Figs. 2, 3) and a spring 17 for adjustment. of the thickness of the applied layer of the paste.

The active end surfaces 18 (Figs. 2, 4, 5) of the centering projections 8 which, when applying the paste, abut against the surface of the blank 5, are directed obliquely 30-H00 towards the vertical axis of the traction sheave, which coincides with the direction of movement of the blank 5 during the application process.

The holder or cam 1a is also formed with guide surfaces 19 (Figs. 2, 3), which are flush with the effective end surfaces 18 of the centering projections. The angle of inclination of the active end surfaces 18 should be such that it prevents the active end surfaces 18 from eventually ending up in the space between the adjacent rows of degrees (or in the holes in the blank 5); The tooth pitch should be chosen depending on the stiffness of the blank and is usually equal to l0-15 mm. The guide surfaces 19, the operative end surfaces 18 and the calibration edge surface 20 of the plate 15 are machined in the assembled state, when the screws 16 are fully tightened.

Each lower edge 15 (Fig. H) below the calibration edge surface 20 is provided with a chamfer 21, which forms a cavity A when the two pockets 1 are brought closer to each other at the blank 5.

In the cavity A - when the blank 5 moves together with a paste 22 and when the thickness of the layer is calibrated by the calibration edge surfaces 20 - an excess of paste is collected which is sufficient to fill the grooves left by the active end surfaces 18 in the applied layer. .

The height of the calibration edge surfaces 20 should be chosen so that depending on the viscosity of the paste - when the blank 5 is stationary and the pocket 1 is filled to the highest possible level - can not flow out through the gaps between the calibration edge surfaces 20 and the blank 5. The bevel 21 cross section dimensions should be selected depending on the calibration edge the surface 20 is satisfied with a mutual dimensional ratio of 1: 2 or 1: 3.

The proposed device operates in the following manner. Before starting the application, the blank 5 (Fig. 1) is guided from the blank coil (not shown) in the drawing via the roller 6 and the device into the oven for drying and sintering the blank coated with the paste and on to the receiving coil not shown in the drawing with the drive device for drawing of the substance 5 throughout the plant. For initial guidance of the blank 5, a nail blank, of the same material as the blank 5, is generally used, which nail blank is attached to the front end of the blank 5. The oven is then heated to a predetermined temperature and filled with shielding gases.

The desired thickness is preset at each side of the blank 5, after which a workshop ruler is placed on the guide surfaces 19 (Figs. 2, 3) and by loosening the screws 16 the predetermined gap is set between the ruler and the calibration edge surface 20 (Figs. 2, 4).

The width of the gap is controlled, for example, by means of a sensing device.

After the desired width of these slots has been set for each pocket 1 (Fig. 1), the pockets 1 are suspended in the shaft pins 3 on the rods 2.

The pockets 1 are brought closer to each other at the blank 5, at the same time as the correct position of the flaps 9 and the free end of the film 13 (Figs. 1, 2) is checked. The pockets 1 are connected to each other by means of the springs Ä, vaoovzzea whose clamping force is regulated so that the active end surfaces 18 (Fig. H) of the centering projections 8 abut tightly against the blank 5 over its entire width and that the blank 5 can be pulled through the drawbar with the least possible traction.

The pockets 1 (Fig. 1) are then filled with paste, after which the device for pulling out the blank 5 is started. The paste 22 (Fig. M), which is pressed against the blank 5 on both sides by the hydrostatic pressure in the paste column in each pocket 1, is drawn by the blank 5 through the gap between the cams 1a to that of the edge surfaces 20 (Fig. Ä) A portion of the excess paste is removed from the back surface of the inclined holders or cams, while the remainder of the paste is removed from the draw plate, whereby a return paste stream, filling the traces left by the active face surfaces 18 in the applied sheet, is removed. 7 After being sintered in the oven, the paste constitutes a porous base component of the strip-shaped substance for the production of electrodes for alkaline accumulators. The sintered substance is then passed on to the following treatment steps according to the process technique used.

The proposed device makes it possible to apply a paste to substances of low thickness and low strength to sintered electrodes for alkaline accumulators and helps to increase the rate of agitation of the substance and to improve the quality of the applied layer by building the feed container in the form of two separate pockets l (Fig. 1) with openings 7 accommodated in the lower part of the pockets 1 for discharging the paste, which makes it possible to carry out the application process by means of the underlying, more compacted layers of the paste, which are pressed against the blank by the hydrostatic pressure of the pasta column in the food container.

By arranging the flaps 9 along the side edges of the openings 7 (Fig. 3), which flaps are pressed against the blank 5 by means of the end surfaces 5 by means of springs 10, the paste can be applied to a blank so that the blank has an uncoated surface or middle portion located uncoated surface, which simplifies the connection of current-dissipating means after finished punching of the electrodes from the sintered and treated substance.

Claims (4)

By holding the holders or cams (Fig. U) with the centering projections 8 and the calibration plates 15 arranged on the belt 5 and inclined towards the plane of the openings 7 along the upper edge of the openings, the control accuracy of the thickness of the applied layer can be increased. due to the fact that the active end surfaces 18 (Fig. 2) of the centering projections of the holder or comb are directed towards the direction of movement of the blank 5 during the application process and that the lower edge of the calibration plate 15 is formed with a bevel which forms a cavity above the centering projections 8, increases in the centering accuracy of the blank 5 in the drawing plate, while eliminating the grooves left by the active end surfaces of the centering projections of the cam 14, whereby any deformation. of the substance and cracking in the applied layer is avoided. Due to the fact that the pockets 1 (fig. 1) in the shaft pins 3 are suspended on parallel bars 2 on both sides of the blank 5, the pockets 1 can be replaced with others during the operation of the device for applying the paste to blanks of other materials. strokes and other dimensions, whereby the device according to the invention can be used in the production of articles in small series, and one can automatically by servo control follow the position of the edge of the applied layer relative to the boundaries of the holes by automatically moving the pockets 1 along the bars 2, 5 shifted. P a t e n t k r a v Device for applying a paste on a strip-shaped blank to sintered electrodes for alkaline accumulators, which device comprises a food container filled with the paste, through which the strip-shaped blank is intended to be drawn during passage through the gap for creating a paste layer with i predetermined thickness on each side of the blank, which draw gap is formed with projections for centering the blank in the gap, characterized in that the container consists of pockets (1) located on each side of the blank (5), which side walls face each other at its lower part is formed with a window-like opening (7) for discharging the paste to the blank (5) during its passage between the pockets (1) and which are pivotally suspended for pressing against each other with their lower parts with the unentering projections (8) abutting against the same, the tension gap being formed by the upper edges of the openings (7). '790 ~ 0? 32-læ ~ 10 f. _, _ »Fn.,,. ff Device according to claim 1, characterized in that flaps (9) with springs (10) are arranged along the side edges of the openings (7) in each pocket (1), which springs (10) are intended to press the end surface of each flap (9) against the blank (5) for limiting the width of the paste-coated part of the blank (5), the lower edge of each opening (7) being sealed by means of an elastic film (13), the free end together with the blank (5) is inserted into the space between the pockets (1) and arranged to be pressed against the blank (5) by the paste pressure. Device according to claim 1, characterized in that calibration plates (15) are inclined along the upper edge of the opening (7) of each pocket and connected to a holder or cam (lä) supporting a centering projections (8) by means of screws (16). ) for regulating the thickness of the layer to be applied. Device according to claim 3, characterized in that the operative end surfaces (18) of the centering projections (8) located in the application line are directed obliquely 30-H00 towards the vertical axis of the tension gap, and that the calibration plates (15) at their lower edge surface are provided with a chamfer (21), which forms a cavity (A) for a volume of pasta sufficient to fill the grooves left by the centering projections (8) in the applied layer.