JP4873982B2 - Plating method and plating apparatus - Google Patents

Description

The present invention is also applied to the inside of a battery can (battery case), in particular, a battery can for storing a power generation element of a secondary battery for a hybrid vehicle or an electric scooter and having a long bottom and a long depth. relates to plating methods and plating equipment can be plated with a uniform plating film thickness. More specifically, a safety valve by groove formation is provided directly on the bottom of the container to prevent explosions, such as battery cans, so as to avoid plating work with impact such as barrel plating. There occurs, about the corrosive safety valve working surface and plating methods and plating equipment can be subjected to sufficient plating to the inner surface of the rear surface and the bottomed tubular body.

Conventionally, when plating on a bottomed cylindrical body, for example, by placing an object to be plated and a dummy in a barrel and immersing it in the plating solution and rotating the barrel, the plating is performed while the object to be plated is fluidly moved in the plating solution. As shown in FIG. 10, the plating is performed by hooking the object to be plated 50 on the support flange 53a of the immersion holder (cathode) 53 immersed in the plating solution 54 and immersing it in the plating solution 54 as shown in FIG. (For example, refer to Patent Document 1) is known. In FIG. 10, 51 is a plating tank and 52 is an anode made of a Ni plate or the like. Further, when plating the bottomed cylinder, since the plating solution is not sufficiently stirred in the cylinder, the concentration of the plating solution drops and the plating in the cylinder is not sufficient, for example, as shown in FIG. In addition to bringing the cathode 53 into contact with the inside of the cylindrical body of the object to be plated 50, a method is also known in which the anode auxiliary electrode 52a is inserted and the inner surface is plated. Further, as shown in FIG. 12, by rotating the object to be plated 50 in the plating solution 54 so as to come out of the plating solution 54, the upper and lower sides of the object to be plated 50 are inverted and the contents in the object 50 to be plated are reversed. A method is also known in which the plating solution is once discharged and immersed again in the plating solution 54 (see, for example, Patent Document 2). 11 and 12, the same parts as those in FIG. 10 are denoted by the same reference numerals, and the description thereof is omitted.
JP 2001-335993 A Japanese Patent Laid-Open No. 10-330989

  As described above, various methods have been tried when plating the inner and outer surfaces of a bottomed cylindrical body, but any method should be adopted as long as the cylindrical object has a shallow depth. Thus, the inner surface of the object to be plated can also be plated.

  On the other hand, in recent years, development of hybrid vehicles has progressed, and development of unit cells of a drive secondary battery system for hybrid vehicles used therefor has also been promoted. In such a battery, a power generation element is inserted and sealed in a battery can formed in a bottomed cylindrical container formed of a steel plate or the like into a cylindrical shape or a rectangular tube shape, and at the bottom of the bottomed cylindrical body. As a safety device when the battery internal pressure rises above a predetermined pressure, a safety valve is formed which is thin and easily broken. Battery cans having such a safety valve are also conventionally used, for example, in lithium ion secondary battery cans such as notebook personal computers and mobile phones. In this type of battery can, the battery capacity is small and the mechanical strength is inferior to that of a steel plate, but there is no problem because a pure aluminum material that does not require plating is used.

  However, the unit cell of the hybrid vehicle drive secondary battery system described above is a bottomed cylindrical body having an inner diameter of 40 mmφ and a depth of about 130 mm, for example, and has a V-shape on the bottom surface along the locus of the gas discharge hole. In addition to forming a safety valve whose tip thickness is as thin as about 0.03 to 0.09 mm, it also prevents corrosion such as oxidation over a very long period (for example, about 15 years). Therefore, it is required that uniform plating is applied on the inner and outer surfaces of the bottomed cylindrical body to a thickness that can withstand corrosion. Therefore, even if a rod-shaped anode auxiliary electrode rod is provided inside the bottomed cylindrical body and plating is performed, plating with an average uniform predetermined plating film thickness is applied to the inner surface of the bottom portion, the corner portion, and the central portion of the cylindrical body. There is a problem that it cannot be applied.

  For this reason, a method is employed in which plating is performed in the state of the plate material before processing, and then a bottomed cylinder is manufactured by drawing, but a steel plate having a thickness of about 0.4 to 1 mm is drawn. When trying to make a bottomed cylinder with a depth of about 130 mm and an inner diameter of about 40 mmφ as described above, the press load of drawing processing is large, and it is difficult to maintain and guarantee anti-rust performance before processing, especially at the corners, Extremely thin, micro-cracks occur, and the opening is not plated and the steel is exposed, and it is a very long bottomed cylindrical body like a battery can for hybrid cars or electric scooters. There is a problem that it is impossible to form a nickel plating having a thickness of 0.4 to 1 μm or more (meaning that the thinnest part is 0.4 to 1 μm) on the inner and outer surfaces.

  The present invention has been made to solve such a problem, and can obtain a predetermined plating film evenly on the inner surface as well as the outer surface as well as the thin and long bottomed cylindrical body on average. It is in providing the plating method which can be performed.

  Another object of the present invention is to provide a plating apparatus capable of continuously plating in large quantities while reliably plating the inner bottom surface and corner portion of a bottomed cylindrical body.

  The inventors of the present invention have a bottomed cylindrical body having a length of 50 mm or more, particularly 130 mm or more, and both the front and back surfaces of the bottomed cylindrical body having a thin portion of the safety valve on the bottom surface, particularly in the corner portion and the groove of the safety valve. As a result of intensive investigations to obtain a battery can for hybrid cars or electric scooters, for example, which has a plating film of at least 0.4 to 1 μm even in a portion that is difficult to be plated, etc. With the post-processing method of processing, it is not possible to obtain a battery can with a sufficient plating thickness on the entire surface, and after processing into the shape of a battery can with a safety valve, the plating solution in the bottomed cylinder is drained and reinserted. Or devise the shape of the anode auxiliary electrode rod, align the concentricity of the anode auxiliary electrode rod with the object to be plated accurately, and place it in the center, or efficiently immerse the plating object in the plating solution It is possible to provide a plating film such as Ni plating with a thickness of several μm on the inner surface of the bottom of a deep bottomed cylindrical body by blowing into the object to be plated and circulating the plating solution in the object to be plated. The present invention was completed by finding that a highly reliable battery can can be obtained.

  The plating method according to the present invention is a plating method in which a metal film is plated on the inner and outer surfaces of an object to be plated consisting of a bottomed cylindrical body whose one end is closed and the other end is opened, the opening side of the object being plated One end of a holding tool that also serves as a cathode is inserted into the inner surface of the object to be plated to hold the object to be plated, and the other end of the holding tool is rotatably supported to By rotating the one end portion, when the object to be plated is pulled up in the plating tank at the position where the opening is immersed in the plating solution and the upper part of the plating tank, the opening of the object to be plated is The plating tank reciprocally moves to a position lower than the bottom, and repeatedly dipping the plating object into the plating solution in the plating tank and discharging the plating solution into the bottomed cylinder of the plating object. Between the anode and the holder And performing a plating metal film on the inner and outer surfaces of the object to be plated by applying a voltage to the. Desirably, the power supplies applied to the outer and inner surfaces of the object to be plated are preferably separately provided in order to easily obtain a predetermined film thickness.

  Here, “rotation” means, for example, a movement in which one end of a rod-like object is supported as a fulcrum and the other end reciprocates within a certain range while drawing an arc.

  An anode auxiliary electrode rod is provided so as to substantially coincide with the central axis of the object to be plated, and the outer shape of the anode auxiliary electrode rod is substantially similar to the outer shape of the bottom surface of the object to be plated. By performing the electrical connection of the counter electrode, which is the electrode facing the bottom of the object to be plated, in a shape, it is even with respect to the wide flat bottom portion, the corner portion, the safety valve portion, and the cylinder central portion. Since it becomes easy to obtain plating electrolysis, it is easy to form a predetermined plating film in these portions evenly on average. The counter electrode may be a Ni plate, but if a noble metal such as platinum or gold is used, Ni ions in the plating solution can be supplied and the electric field can be easily made uniform, thereby contributing to the formation of a stable plating film. In this case, it is economically preferable to use an insoluble metal such as Ti and form a noble metal layer on the surface of the surface facing the object to be plated. Also, since the distance between the counter electrode and the bottom surface of the object to be plated is small, the plating solution is small and Ni ions are easily consumed, but the plating solution in the object to be plated is periodically discharged and replaced. There is no problem of local consumption of Ni ions inside.

  Along with the plating tank, a pretreatment tank and / or a post-treatment tank are provided, and the holder is moved in parallel along each treatment tank, and the holder is moved in a vertical direction. The surface treatment of the object to be plated can be continuously performed by immersing the object to be plated in each treatment tank and discharging the treatment liquid in the object to be plated above each treatment tank. It is possible to automatically and continuously treat a large amount of objects to be plated.

  The other end of the holder is rotatably supported by a support, and the support is moved on the lifting cam plate provided on the plating tank side while moving in parallel along the liquid surface of the plating tank. By sliding the tool, the object to be plated rotates up and down to reciprocate, so that the object can be moved up and down very easily and at regular intervals. Can do.

  A plurality of the holders are prepared, and the other ends of the plurality of holders are rotatably supported by a support at regular intervals in the vertical direction, and the support is moved up and down in the vertical direction. A pusher type elevator that pivots the object to be plated up and down and repeats the immersion of the object to be plated in the plating solution in the plating tank and the discharge of the plating solution in the object to be plated above the plating tank. It can also be a type. By adopting such a configuration, the holder can be formed in multiple stages, so that a plurality of plating processes can be performed at a time.

  The object to be plated fixed to the holder is rotated when the object to be plated is lifted and stopped above the liquid level of the plating tank by the rotation of the holder or the vertical movement of the support. By moving the position where the holder comes into contact with the object to be plated by pressing or pushing, a plating film cannot be formed on the contact portion of the holder. It is preferable because a plating film can be formed.

  If the object to be plated is a battery can that stores and seals a power generation element of a unit cell for a charge / discharge system for driving a hybrid vehicle or an electric scooter, a hybrid vehicle in which a sufficient plating film is formed on the entire inner and outer surfaces Battery cans for electric motors and electric scooters can be obtained.

  The plating apparatus according to the present invention fixes a plating object by bringing one end part into contact with an inner surface of a plating object comprising a plating tank filled with a plating solution and a bottomed cylindrical body having an opening part at one end part, A holding tool having an electrode rod connected to the cathode electrode of the power supply, the other end of which is rotatably supported, and an object to be plated fixed to one end of the holding tool in the plating tank. A rotating means for rotating between a position where the opening of the plated object is immersed in the plating solution and a position where the opening of the plated object is lower than the bottom when it is pulled up to the upper part of the plating tank; And repeatedly rotating the one end of the holder by the rotating means to immerse the plating solution in the plating tank into the plating solution and discharge the plating solution in the object to be plated by lifting it up to the upper part of the plating vessel. It is a device that performs plating.

  The support further includes a support that rotatably supports the holder, and a moving unit that moves the support in the horizontal direction along the plating tank, and the rotating unit moves the holder in the horizontal direction. Formed by a lifting cam plate and a holder provided along a path, and reciprocating to rotate the object to be plated up and down by passing the holding tool over the lifting cam plate. By forming the elevating cam plate, the immersion in the plating solution and the discharge of the plating solution can be alternately repeated with a very simple configuration.

  There is further provided a support that extends in the vertical direction and supports the one or more holders so as to be rotatable, and is movable in the vertical direction and the horizontal direction. A pressing means for applying an external force to the other end of the body and the support are formed so as to rotate about the support portion as a fulcrum, and the substrate is immersed in the plating solution as the support moves in the vertical direction. You may form so that discharge of the plating solution in the said to-be-plated object may be repeated. With such a configuration, a large amount of plating can be performed simultaneously with a small occupied area.

  An anode auxiliary electrode rod is provided at the center of the holder, and the bottom of the object to be plated has an outer shape substantially similar to the outer shape of the bottom surface of the object to be plated at the tip of the anode auxiliary electrode rod. Is provided and provided, it becomes easy to plate the bottom inner surface and the corner of the object to be plated.

  Since a noble metal layer is provided on at least the bottom surface or the side wall of the object to be plated of the anode auxiliary electrode rod and the counter electrode, the uniformity of the electric field is improved, which is preferable for forming a uniform plating film. .

  According to the present invention, even in a cylindrical body having a long and deep bottom, the plating solution in the cylinder can be periodically discharged and replaced. And very thick plating can be applied to the inside of the cylinder. By providing an anode auxiliary electrode rod with good concentricity at the center of the cylindrical body, a more stable plating can be applied to the cylindrical body. Furthermore, by electrically connecting a counter electrode having an outer shape substantially similar to the outer shape of the bottom surface to a portion facing the bottom surface of the bottomed cylindrical body at one end of the anode auxiliary electrode rod, An average uniform plating film can be formed on the wide inner wall surface and the corner portion of the bottom surface of the cylindrical body. As a result, even if unevenness is formed on the bottom surface of the bottomed cylindrical body and the V-shaped tip thin-film gas discharge safety valve is formed, plating with a very stable thickness can be performed. The counter electrode is not limited to a flat plate, but also includes a noble metal part or an insoluble metal part, or a donut shape that penetrates the center part, or the distance from the bottom of the object to be plated is increased. Various shapes such as a trumpet shape or a shape matching the unevenness of the bottom surface of the object to be plated can be used. As a result, even for hybrid car plating cans, plating is performed after machining that has a safety valve, so that both the inner and outer surfaces are 0.4 to 1 μm or more (0.4 mm even in the thinnest part where plating is difficult). ˜1 μm, the same applies hereinafter) with a desired thickness of plating film formed, and reliability as a unit cell can in a hybrid vehicle, electric scooter drive, charge / discharge battery system Can be greatly improved.

  Next, a plating method, a plating apparatus, and a battery can plated by the method according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a partial cross-sectional side view of the battery can, a bottom view thereof, a cross-sectional view of a safety valve portion, and a shape after necking applied to seal an opening after plating. Thus, a length L in which one end 1a of a cylinder or a square tube (cylindrical in the example shown in FIG. 1) is closed by a steel plate material is formed in a bottomed cylindrical body 1 of about 130 mm, for example. A safety valve 1b is formed on the bottom surface 1a so as to be easily broken in the event of battery explosion. This battery can 10 is formed on the inner surface and the back side of the bottomed cylindrical safety valve 1b by, for example, nickel plating after a bottomed cylindrical body having the safety valve 1b is formed by pressing from a plate material. A plating film 2 having a thickness of 4 to 1 μm or more is formed. In FIG. 1 (a), the plating film 2 is exaggerated, and in FIG. 1 (d), the plating film is omitted.

  This battery can 10 has a diameter D of 25 to 45 mmφ, for example, about 40 mmφ, as shown in FIG. 1A by drawing a cold-rolled steel sheet for drawing with a thickness of about 0.5 mm, for example. The length L is 50 to 150 mm, for example, about 130 mm, and the wall thickness is about 0.45 to 0.5 mm. During the drawing process, a thin portion (for example, about 0.03 to 0.9 mm) serving as a safety valve 1b is simultaneously formed on the bottom surface. Since the width w of this thin portion is as very narrow as about 0.5 to 1 mm, it is difficult to form the plating film 2. An Ni plating film 2 having a thickness of about 6 μm and at least about 0.4 to 1.0 μm is formed. The battery can on which the plating film 2 is formed stores the power generation element, and is covered with a sealing plate (not shown), and then the opening is necked as shown in FIG. The element is hermetically sealed to form a necking portion 1d. For this reason, it is necessary that the plating film be in close contact with the necking process.

  The battery can 10 obtained by the plating according to the present invention is formed by the safety valve 1b as described above, so that the processing stress accompanying the formation of a very thin cut groove is concentrated on the groove tip portion, and the groove tip portion and its back surface, which are susceptible to corrosion, A predetermined uniform plating film 2 is also formed on the inner side of the can, and a highly reliable battery can is obtained. The shape of the battery can 10 is not limited to the cylindrical shape shown in FIG. 1, but for example, as shown in FIG. 2, the plate thickness is 0.5 to 1 mm as described above, and a polygonal cylinder such as a quadrangular cylinder. In some cases, a rectangular tube having a length of 80 to 120 mm, for example 80 mm, and a bottom surface of 100 to 200 mm × 15 to 40 mm, for example, about 101 mm × 20 mm is formed.

  Next, a method and apparatus for plating such a bottomed cylindrical body will be described. The most important feature of the plating method according to the present invention is that one end portion of the holding tool 13 serving as a cathode is inserted from the opening 10a side of the object to be plated 10 as shown in FIG. Then, the object to be plated 10 is held in contact with the inner surface of the object to be plated 10, the other end 13 b of the holder 13 is rotatably supported by the support 16, and one end of the holder 13 is rotated. As a result, the opening 10a of the object to be plated 10 is lower than the bottom 10b at the position B1 where the object 10 is immersed in the plating solution 14 with the opening 10a facing up in the plating tank 11 and the liquid surface of the plating tank 14. The position B2 is reciprocated to repeatedly immerse the object to be plated 10 in the plating solution 14 in the plating tank 11 and discharge the plating solution entering the bottomed cylinder of the object 10 to be plated. Plating plating solution Was collected in 11, a voltage is applied between the anode 12 and the holder 13 to be disposed in the plating tank 11 is to carry out plating of the metal coating on the inner and outer surfaces of the object to be plated 10.

  4 (a) to 4 (d), the retainer 13 is shown in FIGS. 4 (a) to 4 (d), the AA cross section of (b), the BB cross section of (a), the CC cross section of (d), and the DD of (a). Each of the cross sections is shown. That is, for example, three electrode rods 131, 132, 133 made of stainless steel and having a thickness of about 4 to 10 mmφ (in the example shown in FIGS. 3 and 4, one electrode rod 133 is placed in the object to be plated 10. The electrode holding plates 134 and 135 are arranged so that the portion to be inserted is formed thin and the spring property is strong) so that the inner wall of the substantially cylindrical object 10 is in contact via a contact point described later. They are held in parallel. As shown in FIG. 4 (d), the three electrode rods 131, 132, 133 are attached to the holding plates 134, 135. As shown in FIG. 4 (d), the electrode plates made of stainless steel directly on the holding plates 134, 135 made of metal plates. As shown in FIG. 4C, the periphery of the holding plates 134 and 135 is covered with an insulating coating material 134a so that the anodes in the center portion are fixed. While being insulated from the auxiliary electrode rod 15, the anode auxiliary electrode rod 15 is fixed by insulating members 152 and 153 so as to be positioned at the center of the holding plates 134 and 135.

  Further, the portions of the electrode rods 131, 132, 133 inserted into the object to be plated 10 are fixed by the pipe ring 136 and the screw 136a as shown in the sectional view of FIG. The two electrode rods 131 and 132 are fixed so as to be concentric with the anode auxiliary electrode rod 15, and the object to be plated 10 is caused by the spring property (biased radially outward) of the remaining one electrode rod 133. The concentricity with the anode auxiliary electrode rod 15 at the center is accurately adjusted while firmly fixing. As a result, the contacts 132a, 132b, and 133a formed on the three electrode rods are in contact with the inner wall of the object to be plated 10 so that the object to be plated 10 can be held. In the example shown in FIGS. 3 and 4, the fixed electrode rods 131 and 132 are each formed with two protruding contact points 132 a and 132 b in the axial direction, and one electrode rod 133 having a spring property is provided. The contact 133a is formed. In FIG. 3, the lower pipe ring 136 is omitted.

  The anode auxiliary electrode rod 15 fixed to the holder 13 is accurately placed so that the end face of the pipe ring 136 can be used as a stopper so that the insertion depth can be accurately defined when the workpiece 10 is inserted. The electrode rods 131, 132, and 133 are fixed to each other with proper positioning. The pipe ring 136 defines the insertion depth of the object to be plated 10 and is formed so that the inner wall of the object to be plated 10 can be fixed in parallel with the electrode bars 131, 132, and 133.

  On the other end side of the anode auxiliary electrode rod 15, the anode auxiliary electrode fixing member 154 and the holding plate 137 are fixed by a screw or the like, and the end portion is the other end portion 13 b of the holder 13. The anode auxiliary electrode fixing member 154 and the holding plate 137 may be an integrated body formed in a U shape. And the edge part (other end part 13b of the holder 13) of the holding | maintenance board 137 is supported by the support body 16 fixed to the intermittent conveyance chain 17 so that rotation is possible. A cam receiving plate 138 is attached to the holding plate 137, and one end portion 13a of the holding tool 13 is rotated up and down by an elevating cam plate 18 described later. The bending angle at which the holding plate 137 and the anode auxiliary electrode fixing member 154 are formed in a square shape is such that the other end 13b side of the holding tool 13 is horizontal (position where the support 16 and the holding plate 138 are linear). The angle θ1 (bending angle from the horizontal plane) at which the plated product 10 is immersed in the plating solution 14 in the plating tank 11 is set, and in the example shown in FIG. 3, θ1 is formed at about 35 °.

  In the example shown in FIG. 3, an anode auxiliary electrode rod 15 made of a material insoluble in a plating solution such as a titanium material and having a thickness of about 4 to 10 mmφ is provided at the center of the holder 13. In addition, a platinum foil having a thickness of about 3 to 5 μm is attached to a portion functioning as an auxiliary electrode of the auxiliary anode electrode rod 15 (a portion facing the inner wall of the object to be plated 10). If the anode auxiliary electrode rod 15 is not located on the central axis of the object to be plated 10, the inner surface plating of the object to be plated 10 cannot be performed uniformly. Therefore, in the present invention, the anode auxiliary electrode rod 15 is positioned together with the three fixed electrode rods 131, 132, 133, and the electrode holding plate 134, so as to be parallel to the electrode rods 131, 132, It is inserted into 135 and fixed by insulating members 152 and 153 (see FIG. 4C). Of the electrode rods, one electrode rod 133 is thinned on the insertion side to the object to be plated 10, and the contacts 132a, 132b, 133a, etc. of the three electrode bars 131, 132, 133 are all together. The object to be plated 10 can be held in close contact with the inner wall.

  In the present invention, the tip of the anode auxiliary electrode rod 15 is made of, for example, a titanium disk with a platinum foil having a thickness of about 3 to 5 μm, for example. A counter electrode 151 that is an electrode facing the bottom surface of the object to be plated 10 is provided in a substantially similar shape. The counter electrode 151 is provided in order to make it easy to form a plating film having a predetermined thickness on the inner side and the corner of the bottomed cylindrical body that is the object to be plated 10. In the case of Ni plating, it can also be formed with a Ni plate, but as the plating process is performed, it gradually becomes thinner and does not function as an anode, and fine metal pieces and dissolved residues are generated. If it falls on the surface and adheres to the plating surface and a plating film is formed thereon, the appearance of plating and the quality of plating will be impaired. Therefore, in the present invention, as shown in an enlarged view in FIG. 5A, the counter electrode 151 and the anode auxiliary electrode rod 15 are formed of an insoluble titanium material or the like, and the surface of the counter electrode 151 and the anode auxiliary electrode rod 15 are opposed to each other. By attaching platinum foils 151a and 15a (thickness of about 3 to 5 μm) to the portions to be applied, the uniformity of the electric field is ensured and a uniform plating film is formed.

  The shapes of the counter electrode 151 and the platinum foil 151a are not disc-shaped as shown in FIG. 5A, and the counter electrode 151 as shown in FIG. The center portion may be cut into a donut shape (the entire counter electrode may be donut-shaped), and as shown in FIGS. 5C and 5D, both the plate-like body 151 and the platinum foil 151a have the center portion. It can be formed into a concave mortar shape or a flat shape at the end thereof, and is set so that a uniform plating film is formed in relation to the shape of the object to be plated. By denting such a donut shape and the center, the electric field to the flat surface at the center of the bottom can be weakened, and the electric field can be spread around the bottom, that is, the corners of the bottomed cylindrical body accordingly. A uniform plating film can be formed on the entire inner surface. In addition, when the bottom surface of the object to be plated 10 has unevenness, the unevenness can be formed on the counter electrode 151 in accordance with the unevenness.

  Further, the counter electrode 151 is preferably formed in a shape similar to the outer shape of the bottom surface of the object 10 to be plated. Since the object 10 to be plated is a cylindrical body in the above example, a disk is used. When the object to be plated 10 is a rectangular tube, it is formed in a shape similar to the shape of the bottom surface. The position of the counter electrode 151 is such that the distance between the bottom surface of the object to be plated 10 is about 7 to 25 mm and the distance between the outer peripheral end and the inner surface of the object to be plated 10 is about 3 to 10 mm. Formed in size. It is better to oppose the bottom surface of the object to be plated 10 as much as possible, but if it is too large, the plating solution will not easily enter the back, and the auxiliary anode electrode plate 151 and the object to be plated 10 will be easily short-circuited. Although the thickness is not so limited, it is formed to have a thickness of about 0.5 to 1.5 mm.

  Further, in the plating apparatus of the present invention, a plating solution injection nozzle is provided so that the holder 13 moving while being intermittently conveyed can be operated when the object to be plated 10 is immersed in the plating tank 11 and stopped. 19 is provided so that the plating solution 14 in the plating tank 11 is blown into the object to be plated 10 by the pump 20 so that the plating solution in the object to be plated 10 can be replaced. In this case, although not shown in FIG. 3, the plating solution is directed toward the bottom in the object to be plated 10 by providing the spray nozzle 19 with the spray port directed so as to blow into the pipe ring 136 described above. It is blown and can be circulated efficiently.

  A pair of power supply terminals 25 and 26 are fixed to the support 16, and one end portions of each of the power supply terminals 25 and 26 are connected to the anode auxiliary electrode rod 15 and the electrode rods 131, 132 and 133 by the wiring 28. A power source 27 is connected to the other end of the.

  In order to move the one end of the holding tool 13 up and down, the other end 13b of the holding tool 13 is supported by the support 16 at the pivot point 139 and attached to the holding plate 137 as described above. For example, can be moved up and down by a lift cam plate 18. A cam attached to the holding plate 137 by a horizontal transverse cam plate 181 and a lifting cam plate 18 provided in a direction perpendicular to the paper surface of the cam receiving plate 138 portion of FIG. FIG. 6 shows a mechanism for easily understanding the relationship in which the receiving plate 138 moves up and down.

  3 and 6, the horizontal cam plate 181 is provided with elevating cam plates 18 at regular intervals along the path along which the support 16 to which the holder 13 is attached moves in parallel by the intermittent conveyance chain 17. A cam receiving plate 138 attached to the tool 13 moves up and down along the shape of the elevating cam plate 18. Along with this, the one end portion 13a (the object to be plated 10) of the holder 13 moves up and down with the other end portion 13b as a rotation fulcrum. That is, in FIG. 6, when the cam receiving plate 138 is moved to the right side of the drawing by the intermittent conveyance chain 17 and is at a position on the horizontal traversing cam plate 181 of C and D, the one end 13a of the holder 13 is the first. When the object to be plated 10 shown in FIG. 3 is immersed in the plating solution 14 when it is in the low position, it moves through the plating solution 14 at the same height even if it moves to the position D. Move horizontally. Therefore, plating proceeds during this movement.

  Next, when the cam receiving plate 138 gets on the elevating cam plate 18, the holder 13 is lifted, and when it reaches the position E, it is lifted to the position of the holder 13 written on the upper side of FIG. This position is set to an angle at which the opening 10a of the object to be plated 10 is lower than the bottom 10b, that is, an angle at which the plating solution in the object to be plated 10 is discharged. This lifting angle (θ2 in FIG. 3) can be set freely depending on the shape of the lift cam plate 18, but if it is lifted too high, the time for the object to be plated 10 to come out of the plating solution becomes longer and the plating is performed for a long time. Exposure from the liquid is not preferable because the object to be plated 10 is oxidized and the plating state at the time of re-immersion and plating deteriorates and the plating efficiency also deteriorates. Therefore, the inclination angle θ2 of the holder 13 (inclination angle of the object to be plated 10) is an angle at which the plating solution in the object to be plated 10 can be discharged, that is, about 5 to 30 °, preferably about 5 to 15 °. In the example shown in FIG. 3, the elevating cam plate 18 is formed so that θ2 is 10 °.

  The time relationship between the plating time and the discharge of the plating solution in the object to be plated is, for example, a step of immersing in the plating solution for about 6.7 minutes, and lifting and discharging from the plating solution in 12 to 16 seconds. The plating process is completed by repeating the process of returning to the solution about 5 times. Of the five times, “contact position shift” is performed about 2 times after the discharging operation.

That is, in the present invention, by lifting the holder 13 and rotating the object 10 to be plated with respect to the holder 13 by 5 to 90 ° while the object 10 is outside the plating solution 14, The contact positions of the contact points of the electrode bars 131, 132, and 133 are changed to the object to be plated 10. This is because the plating film is not formed on the object to be plated at the position of the contact, so that not only the plating film is formed at that position but also the average over the inner and outer surfaces in the circumferential direction of the battery can. In order to easily obtain a plating film having a predetermined thickness. Such rotation of the object to be plated 10 is performed by, for example, mounting an air chuck on a rotary table of an air pressure (about 5 kg / cm ² ) operating function element (for example, SMC Corporation equipment), When stopped by the stop signal, the object to be plated 10 is chucked and rotated by, for example, 90 ° on the rotary table. After the rotation is finished, the chucking is released and the rotary table is automatically returned to the next position. This can be done by preparing the object to be plated. In addition, it is preferable that the position of the object to be plated for chuck-and-rotate is a position where the next conveyance pitch is stopped without lowering again after discharging the liquid in the can, and at a horizontal angle of θ1 = 0 °. Also, in the case of a square cylinder (see Fig. 2), chuck and rotary are difficult. As an alternative, the contact position can be shifted by pushing the object to be plated in the axial direction with an air cylinder. .

  When actually performing plating, post-treatment such as pre-treatment of an object to be plated or water washing after plating is performed. In the plating apparatus of the present invention, these series of processing steps are performed by the above-described lifting cam plate. Processing can be performed sequentially while being conveyed. A schematic plan view of such a processing apparatus is shown in FIG.

  That is, in FIG. 7, the above-mentioned intermittent conveyance chain 17 is provided so as to be driven by the intermittent drive gear 31, and each processing tank is provided around it along with a load table and an unload table. And the to-be-plated object 10 is fixed to the above-mentioned holder 13 connected to the intermittent conveyance chain 17, and the conveyance chain 17 is sequentially moved by 1 pitch (for example, 76.2 mm) by the intermittent drive gear 31 and stopped (immersion process). Repeating the load, alkaline degreasing, water washing, cathodic electrolytic degreasing, water washing, anodic electrolytic degreasing, water washing, weak acid immersion, water washing, Ni strike plating, water washing, semi-gloss Ni plating, recovery, water washing, water draining, water washing, unloading Each process is performed in order. In FIG. 7, water washing is omitted. At this time, as described above, during processing, when the one end portion 13a of the holding tool 13 is lowered so that the object to be plated 10 is immersed in the processing tank, and when the processing is finished and moved to the next processing tank, The above-described lifting cam plate 18 is provided along the transport chain 31 so that the object to be plated 10 can be lifted so as to be in the high position in FIG. 3 and the processing liquid can be collected and transported to the next processing tank. It has been. As a result, from pre-treatment to post-treatment of plating, and replacement of the plating solution in the object to be plated during the above-described plating process can be automatically performed continuously.

  In the above-described example, when the holder 13 is moved on the elevating cam plate 18 when transporting along the plating tank, the object to be plated is rotated. If it is going to be, it will be necessary to arrange a holder in parallel in the horizontal direction, the occupation area of a plating tank will become large, and a processing apparatus will become large. FIG. 8 shows an example of a plating apparatus capable of rotating a plating object immersion and plating solution discharge without increasing the occupation area while simultaneously performing a plurality of plating processes. It is structure explanatory drawing which shows the example of an automatic conveyance plating apparatus.

  That is, in FIG. 8, the structure of the holder 13 is the same as the example shown by FIGS. 3-4, the same code | symbol is attached | subjected to the same part (a part is abbreviate | omitted), and the description is abbreviate | omitted. In this example, a support body 16 that supports the other end 13b of the holder 13 so as to be rotatable is provided so as to extend in the vertical direction, and is provided so that the support body 16 can be moved up and down in the vertical direction. It has been. A plurality of holders 13 (only one holder may be provided) are supported so as to rotate about the shaft 139 as a rotation fulcrum with a predetermined interval in the vertical direction of the support body 16, and further The end portions of the plurality of holders 13 (end portions of the holding plate 137) are connected by the connecting link plate 63, and the connecting link plate 63 is pushed downward, so that the shaft 139 serves as a rotation fulcrum. When the one end 13a is lifted upward and the pressing of the connecting link plate 63 is released, the one end is lowered by the weight of the holder 13 and the object to be plated 10, stops at the stopper 161, and is immersed in the plating solution 14 at a predetermined angle. Note that the pressing of the connecting link plate 63 is easily given by rotating a pressing operation lever 62 by an air cylinder 61 as shown in FIG.

  Further, when a plurality of holders 16 are attached to the support body 16, it is necessary to deepen the plating tank 11, and when the one end 13 a of the holder 13 is lifted by this pressing, the support body 16 is moved in the vertical direction. It is preferable to perform while moving upward or after moving, because the plating solution in the object to be plated 10 can be completely discharged. Although this vertical movement mechanism is omitted, the conceptual diagram in the case of sequentially moving the treatment tank in the case where the pre-treatment and post-treatment of the plating treatment described above are continuously performed while conveying the object to be plated. As shown in FIG. 9, for example, the support 16 is fixed to the lifting / lowering booth bar / guide rail 17a, and the lifting / lowering booth bar / guide rail 17a is vertically lifted to feed one feed pitch. Therefore, it is possible to perform processing in different processing tanks by lowering again. When the plating process is performed, the plating tank is long and is lifted as described above to discharge the plating solution in the object to be plated, soaked in the plating solution again by sending 1 pitch, and further lifted and discharged. The discharge is repeated while feeding one pitch at a time. When performing pre-treatment and post-treatment other than plating, the treatment liquid in the treatment tank is different, but in the present invention, the plating liquid and treatment liquid in the object to be plated are discharged when lifted, There is no mixing. In FIG. 8, reference numeral 41 denotes a holder guide that holds the support 16 firmly in the vertical direction, and 42 denotes a switchboard.

  As described above, according to the present invention, as in battery cans for hybrid vehicles and electric scooters, even a long bottomed cylindrical body requires a minimum movement to replace the plating solution in the cylinder (from plating solution to plating) Since the movement to take out the object is the minimum movement that can drain the plating solution in the object to be plated), even if the object to be plated comes out of the plating solution, it will oxidize or become dirty. Therefore, very stable plating can be performed, and since the plating solution in the cylinder is regularly exchanged, the bottom of the inner surface of the bottomed cylinder can be sufficiently plated.

  Furthermore, since the object to be plated is held with three metal rods, two of them are fixed, and the remaining one is fixed with springiness, so that the metal rod as the cathode is to be plated. Since the anode auxiliary electrode rod provided at the center can be fixed and provided concentrically, the plating on the inner surface can be provided more uniformly and sufficiently. Furthermore, by providing a counter electrode opposite to the bottom surface of the object to be plated at the tip of the anode auxiliary electrode rod, a plating film having a predetermined thickness is provided evenly on the inner surface and corner of the deep bottom. Can be formed.

  As a result, there is a safety valve such as an explosion-proof device, and even with a bottomed cylinder having a depth of 50 mm or more, a plating film with a thickness of at least 0.4 to 1 μm or more is formed on the bottom and inside thereof, and 15 years. A battery can for a hybrid vehicle that requires reliability for a very long time as described above can be obtained by a post plating method.

It is a figure explaining one Embodiment of the battery can by this invention. It is a figure which shows the shape modification of the battery can by this invention. It is a figure explaining the outline | summary of the principal part of the plating apparatus by this invention. It is principal part explanatory drawing of the holder of FIG. It is a figure which shows the modification of the shape of the counter electrode attached to the front-end | tip of an anode auxiliary electrode stick | rod. It is a figure explaining the vertical motion of the holder by a raising / lowering cam. It is plane explanatory drawing which shows the outline | summary of the whole plating apparatus by this invention. It is a figure explaining the outline | summary of the principal part of other embodiment of the plating apparatus by this invention. It is a figure which shows the conceptual diagram in the case of performing each process, conveying a to-be-plated object with the apparatus shown by FIG. It is a figure which shows an example of the conventional plating apparatus. It is a figure which shows the other example of the conventional plating apparatus. It is a figure which shows the other example of the conventional plating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bottomed cylinder 1a Bottom surface 1b Safety valve 2 Plating film 10 Plated object 10a Opening part 10b Bottom part 11 Plating tank 12 Anode 13 Holder 131-133 Electrode bar 134, 135 Electrode holder plate 138 Cam receiving plate 14 Plating solution 15 Anode auxiliary Electrode rod 151 Counter electrode 16 Support 17 Intermittent transport chain 18 Lifting cam plate 19 Injection nozzle

Claims (12)

  A plating method for plating a metal coating on the inner and outer surfaces of an object to be plated comprising a bottomed cylindrical body having one end closed and the other end opened, the holder also serving as a cathode from the opening side of the object to be plated One end of the holder is inserted and brought into contact with the inner surface of the object to be plated to hold the object to be plated, and the other end of the holder is rotatably supported to rotate the one end of the holder. Thus, when the object to be plated is immersed in a plating solution with the opening facing up in the plating tank and the upper part of the plating tank, the opening of the object to be plated is positioned lower than the bottom. Reciprocating between the anode and the anode disposed in the plating tank while repeating the immersion of the plating object into the plating liquid in the plating tank and the discharge of the plating liquid entering the bottomed cylinder of the plating object; and A voltage is applied between the holder and the Plating method for performing the plating of the metal coating on the inner and outer surfaces of the key material.   An anode auxiliary electrode rod is provided so as to substantially coincide with the central axis of the object to be plated, and the outer shape of the anode auxiliary electrode rod is substantially similar to the outer shape of the bottom surface of the object to be plated. The plating method according to claim 1, wherein the counter electrode, which is an electrode facing the bottom of the object to be plated, is electrically connected in shape.   Along with the plating tank, a pretreatment tank and / or a post-treatment tank are provided, and the holder is moved in parallel along each treatment tank, and the holder is moved in a vertical direction. The surface treatment of the object to be plated is continuously performed by immersing the object to be plated in each treatment tank and discharging the treatment liquid in the object to be plated above each treatment tank. 3. The plating method according to 1 or 2.   The other end of the holder is rotatably supported by a support, and the support is moved on the lifting cam plate provided on the plating tank side while moving in parallel along the liquid surface of the plating tank. The plating method according to any one of claims 1 to 3, wherein the object to be plated is rotated up and down to reciprocate by sliding the tool.   A plurality of the holders are prepared, and the other ends of the plurality of holders are rotatably supported by a support at regular intervals in the vertical direction, and the support is moved up and down in the vertical direction. 4. The object to be plated is rotated up and down to repeatedly immerse the object to be plated in a plating solution in the plating tank and discharge the plating solution in the object to be plated above the plating tank. The plating method according to any one of the above.   When the object to be plated is out of the plating bath liquid surface by the vertical movement of the holder or the vertical movement of the support, the object to be plated fixed to the holder is rotated. The plating method according to any one of claims 1 to 5, wherein a position where the holder comes into contact with the object to be plated is moved by pressing.   7. The battery can for a secondary battery for storing and sealing a power generation element of a unit cell for a charge / discharge system for driving a hybrid vehicle or an electric scooter. 8. Battery can plating method.   A plating tank filled with a plating solution and an inner surface of an object to be plated consisting of a bottomed cylindrical body having an opening at one end are fixed to the object by contacting one end of the object and connected to the cathode electrode of the power source. A holding tool whose other end is rotatably supported, and an object to be plated fixed to the one end of the holder in the plating tank. And rotating means for rotating the position between the position where the plating object is immersed in the plating solution and the position where the opening of the object to be plated is lower than the bottom when the plate is pulled up. A plating apparatus for performing plating by repeatedly immersing the plating tool in the plating tank and discharging the plating liquid in the object to be plated by lifting it to the upper part of the plating tank by moving the one end of the holder up and down by means.   The support further includes a support that rotatably supports the holder, and a moving unit that moves the support in the horizontal direction along the plating tank, and the rotating unit moves the holder in the horizontal direction. Formed by a lifting cam plate and a holder provided along a path, and reciprocating to rotate the object to be plated up and down by passing the holding tool over the lifting cam plate. The plating apparatus according to claim 8, wherein an elevating cam plate is formed.   There is further provided a support that extends in the vertical direction and supports the one or more holders so as to be rotatable, and is movable in the vertical direction and the horizontal direction. A pressing means for applying an external force to the other end of the body and the support are formed so as to rotate about the support portion as a fulcrum, and the substrate is immersed in the plating solution as the support moves in the vertical direction. The plating apparatus according to claim 8, wherein the plating apparatus is formed so as to repeatedly discharge the plating solution in the object to be plated.   An anode auxiliary electrode rod is provided at the center of the holder, and the bottom of the object to be plated has an outer shape substantially similar to the outer shape of the bottom surface of the object to be plated at the tip of the anode auxiliary electrode rod. The plating apparatus according to any one of claims 8 to 10, wherein a counter electrode is provided so as to be opposed to the electrode.   The plating apparatus according to claim 11, wherein a noble metal layer is provided on a surface of the anode auxiliary electrode rod and the counter electrode facing at least a bottom surface or a side wall of the object to be plated.

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