JP2005350699A - Electroplating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroplating device where, in the case surface treatment is performed to the objects to be plated by dipping the same into a liquid bath, satisfactory plating films, particularly, plating films having uniform plating thickness are formed. <P>SOLUTION: The electroplating device comprises: a liquid tank storing a plating liquid for treating the objects to be plated; a negative voltage applying part installed in the liquid bath and applying negative voltage to the objects to be plated; a positive electrode part installed in the liquid bath and to which positive voltage is applied; and a plurality of auxiliary electrode parts installed in the positions surrounding the objects to be plated dipped into the liquid bath. The auxiliary electrode parts are installed in such a manner that, in the case the plurality of objects to be plated are held by a holder to the same face and are dipped into the liquid bath, their location comes to the face the same as that of the objects to plated, and is also made symmetric with respect to the respective objects to be plated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrolytic plating apparatus for performing a plating process on an object to be plated.

  The surface of a bag-like workpiece, for example, a cap nut, is subjected to a treatment such as electrolytic plating. When the outer surface and the inner surface of the bag-shaped workpiece are subjected to treatment such as acid electrolysis (scaling after quenching) or electrolytic plating, a so-called immersion holder in which a fish bone is suspended upside down is often used. By attaching one cap nut to each branch part of the immersion holder from its opening, a large number of cap nuts are in a tree shape with each facing upward (the opening is inclined downward). The holding tool is dipped in an acid electrolysis tank (mainly sulfuric acid solution or the like), a plating tank or the like together with a number of cap nuts to perform descaling or plating (Patent Document 1).

  FIG. 20 conceptually shows a conventional immersion holder for holding a cap nut and immersing it in a plating tank or the like. (A) is a front view of the immersion holder 201. FIG. The dipping holder 201 has a support collar 202 formed in a shape that faces obliquely upward from the main body frame. The dipping holder 201 holds the cap nut 1 in such a manner that the opening of the cap nut 1 is inserted into the support collar 202. FIG. 20 (b) shows the immersion holder 201 immersed in the plating tank 215. The figure shows the side of the immersion holder 201. In this manner, the bag-shaped nut 1 is held by the immersion holder 201 and immersed in the plating tank 215 or the like to perform the surface treatment of the outer surface and the inner surface. At this time, the electrode 211 is installed in the plating tank 215, a positive voltage is applied, and a negative charge is applied to the immersion holder 201 to perform the surface treatment of the cap nut 1.

JP 2001-335994 A

  However, in the process of immersing the immersion holder 201 together with a number of cap nuts 1, for example, in a bath such as a plating bath 215, a solution such as a plating solution enters the closed space (closed space) of the cap nut 1. However, the liquid cannot be filled in the closed space by the air confined in the closed space, and a portion that cannot contact the liquid remains on the inner surface of the cap nut. In addition, there is a situation where most of the current flows to the outer surface of the cap nut 1 and hardly flows to the inner surface. That is, according to such a method, it is difficult to treat the entire inner surface of the cap nut with a plating solution or the like.

  Further, when the support collar 202 is formed in multiple stages as in the immersion holder 201 of FIG. 20, the thickness of the plating layer formed on the cap nut held on the upper stage and the cap nut held on the lower stage is greatly increased. It will be different. This is because the current flow is not uniform because of multiple stages, and a thick plating layer is formed on the lower cap nut. That is, the plating thickness varies between products.

  Accordingly, an object of the present invention is to provide an electroplating apparatus that forms a good plating film, particularly a plating film having a uniform plating thickness, when a surface treatment is performed on an object to be plated by being immersed in a liquid bath. That is.

Means for Solving the Problems and Effects of the Invention

The electrolytic plating apparatus of the present invention for solving the above problems is
A bath for storing a plating solution for processing an object to be plated;
A negative voltage application unit that is installed in the liquid tank and applies a negative voltage to the object to be plated;
A positive electrode part installed in the liquid tank and applied with a positive voltage;
A plurality of auxiliary electrode portions installed in positions in the liquid tank surrounding the immersed object to be plated;
And plating is performed by immersing the object to be plated in a plating solution in a liquid bath.

  The object to be plated can be immersed in a plating solution stored in the liquid tank, and the object to be plated can be subjected to electrolytic plating treatment by the negative voltage application part, the positive electrode part, and the plurality of auxiliary electrode parts. In addition to the negative voltage application part and the positive electrode part, it has a plurality of auxiliary electrode parts, and in particular, the auxiliary electrode part is installed at a position surrounding the object to be plated, so that a good plating film can be formed.

  And a positive electrode part is installed in one side in a liquid tank, and the other side opposite to it, and a plurality of auxiliary electrode parts are installed between positive electrode parts. When the plating process is performed by the positive electrode part and the negative voltage application part, the current does not flow uniformly in the plating tank, which causes a variation in plating thickness between the objects to be plated. However, by providing the auxiliary electrode portion in this way, it becomes possible to flow a current stably.

  Further, when a plurality of objects to be plated are held on the same surface by a holder and immersed in a liquid bath, the auxiliary electrode portion is on the same surface as the object to be plated and in a symmetrical position with respect to each object to be plated. Should be installed. By installing the auxiliary electrode portion in a symmetrical position with respect to the object to be plated in this way, it is possible to allow a current to flow uniformly to the object to be plated and thereby the film of the plating film formed on the object to be plated The thickness can be made uniform.

  And to-be-plated object is hold | maintained with a holder, the to-be-plated object is immersed in a liquid tank with a holder, and a negative voltage is applied to a to-be-plated object through a holder. The plating film can be formed on the object to be plated by applying a negative voltage to the object to be plated through the holder.

  More specifically, in the auxiliary electrode portion, from one positive electrode portion, the auxiliary electrode portion row and the plated object row are alternately arranged, and the n + 1 auxiliary electrode portion row next to the nth plated row. (N is a positive integer), and is further arranged side by side with the other positive electrode part. As described above, since the auxiliary electrode row and the row of the objects to be plated are alternately arranged, a current can be stably passed through the object to be plated, and a good plating film can be formed.

The electroplating apparatus of the present invention is
A holder for holding workpieces, which are individual objects to be plated, at predetermined intervals so as to form two or more linear and parallel rows is immersed in the plating bath together with the multiple rows of workpieces held there. Assuming that multiple workpiece rows are almost parallel to the liquid level of the plating bath,
Auxiliary electrode portion rows in which a plurality of auxiliary electrode portions are arranged at a predetermined interval are arranged on both sides of each row in the plurality of workpiece rows so as to be parallel to the workpiece row, and each auxiliary electrode portion row has a pitch between the workpiece rows. The pitch between the rows of the auxiliary electrode portions and the pitch between the rows of the workpiece rows are made equal so that the pitch between the workpieces in the workpiece row and the auxiliary electrode portion row are The pitch between the electrodes of the auxiliary electrode section is made equal, and the pitch between the electrodes of the auxiliary electrode section row and the inter-work pitch of the work row are shifted by a half pitch, so that the pitch between the workpieces of the work row is ½ pitch. Each auxiliary electrode portion of the auxiliary electrode portion row is positioned in a staggered manner at the point, and when focusing on one workpiece, the center corresponding to the four corners on the diagonal of the rectangle centering on the one workpiece Equidistant from each other So as to be positioned auxiliary electrode portion 4 located on the auxiliary electrode portions are arranged in the plating solution tank at a position that does not interfere with the immersion movement of the plating solution tank of the holder.

  As described above, the auxiliary electrode portion row and the workpiece row are substantially parallel, each auxiliary electrode portion row is located at a half pitch point of the inter-row pitch of the work row, and the inter-electrode pitch of the auxiliary electrode portion row. Since the inter-work pitch in the work row is shifted by a half pitch, the auxiliary electrode portion is formed at a symmetrical position with respect to each work. Since such an arrangement is adopted, it is possible to allow a current to flow uniformly to each workpiece, and thus the plating thickness of each workpiece can be formed uniformly.

  And the to-be-plated object processed with this electrolytic plating apparatus is the bag-shaped workpiece | work which has bag-shaped space, for example. More specifically, for example, a hub nut.

  By adopting the arrangement of the auxiliary electrode part, the work, and the positive electrode part as described above, it is possible not only to prevent variations in plating thickness among a plurality of works, but also a film within one work. Unevenness of thickness can be suppressed. That is, the entire workpiece can be made to have a uniform plating film thickness. Further, as described above, the auxiliary electrode portions arranged in symmetrical positions with respect to the respective workpieces are not limited to the case where they are installed in the plating solution tank. You may install an auxiliary electrode with the same arrangement | sequence on the holder for hold | maintaining a workpiece | work.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cap nut as an example of a bag-like workpiece. The cap nut 1 includes a main body 2 having a female screw portion 4 and a cap portion 3 that closes the opening of the main body 2 on the side opposite to the screwing side of the screw member. A bag-like space (closed space) 5 is formed by a place (a portion into which a tip portion of a male screw member such as a bolt enters). The outer surface of the main body 2 has a flange 7 protruding to the side. An example of such a cap nut is a hub nut. Such a cap nut 1 is immersed in a predetermined bath for cleaning, rust prevention, plating, etc. after forging, further threading by rolling or cutting, welding of the cap 3 and heat treatment as necessary. Is done.

  At that time, an immersion holder 21 which is a work holding member as shown in FIG. 2 is used. The immersion holder 21 includes a base portion 27 having a through-hole penetrating the upper surface and the lower surface, a protruding tube 25 as a suction tube (or also a discharge tube) extending from the through-hole on the upper surface side of the base portion 27, A guide shaft 24 extending from the base portion 27; a sliding plate 26 having an insertion hole (through hole) into which the plurality of protruding tubes 25 and the guide shaft 24 are inserted; support shafts 23a and 23b that support the guide shaft 24; A support plate 22 connected to the support shafts 23a and 23b is provided. The immersion holder 21 is formed of a conductor such as metal so that a current can flow. For example, titanium can be used. However, the support plate 22 is formed of a non-conductor to insulate the support shaft 23a and the support shaft 24b (if the support shaft 23a and the support shaft 24b are insulated, the entire support plate 22 is a non-conductor. Need not be). The support plate 22 is not limited to the shape shown in the figure as long as it can be connected to the transport line. Although the base portions 27 are formed in two rows in parallel, they are not necessarily formed in two rows or in parallel. Further, although three protruding tubes are formed on each base portion 27, the number of protruding tubes is not limited to three. Increasing the number of bases and the number of protruding tubes makes it possible to process many bag-like workpieces simultaneously.

  In the case of a conventional immersion holder having a multi-stage bag-like workpiece holder, a liquid tank for pretreatment and plating needs to be formed deeply, whereas the immersion holder 21 has a protruding tube 25 on one side. Since they are arranged on the top, the depth of the liquid tank for pretreatment and plating can be reduced. Since the washing tank can also be made shallower, the amount of water supplied and discharged is reduced. Moreover, the building which installs a plating processing line can be made lower than before. Furthermore, in the case of the conventional multistage immersion holder, there is a difference in the plating thickness between the bag-like workpiece held in the upper stage and the bag-like workpiece held in the lower stage, but this immersion holder 21 is formed in one stage. Therefore, a difference in the plating thickness of the bag-like workpiece is unlikely to occur. In the conventional multistage immersion holder, when the plating treatment is performed in order to make the plating thickness 25 μm, the plating thickness variation of about 10 μm occurs between products. Since the object to be plated has a one-stage structure in which the object to be plated is arranged on one surface, the immersion thickness of the immersion holder can be suppressed to about 2 to 3 μm.

  FIG. 3 shows an enlarged cross-sectional view of the immersion holder 21. A plurality of through holes 28 are formed in the base portion 27 (in the case of the embodiment of FIG. 2, one base portion 27 has three through holes), and the protruding tube 25 is formed on the through hole 28. ing. An insulating portion 12 (for example, a resin mold) is formed on the surface of the protruding tube 25 except for the distal end portion 35. The through hole 34 of the projection tube 25 and the through hole 28 of the base portion 27 are formed in a row, and from the lower portion of the base portion through hole 28 to the upper portion of the projection tube through hole 34 or from the upper portion of the projection tube through hole 34. A gas or a liquid can flow to the lower part of the base through hole 28. The cap nuts 1 are attached to the tip portions 35 of the protruding tubes 34 one by one. The sliding plate 26 is formed with a guide shaft 24a and a through-hole 33 for inserting the protruding tube 25. The sliding plate 26 is guided by the guide shaft 24a and can slide along the guide shaft 24a. It is. The protruding tube 25 is located in the through hole 33 of the sliding plate 26. The guide shaft 24a and the base portion 27 are electrically insulated by the insulating portion 11 (for example, vinyl chloride).

  FIG. 4 shows an enlarged perspective view of the immersion holder 21. An example in which the cap nut 1 is attached to the middle protruding tube 25 is shown. The cap nut 1 is mounted so as to cover the tip portion 35 of the protruding tube 25. In the figure, the cap nuts 1 are not attached to the other protruding tubes 25, but in the surface treatment step, the cap nuts are usually attached to the tip portions of all the protruding tubes 25. The figure also shows that the sliding plate 26 is set at the raised position moved upward. When the sliding plate 26 is in the raised position, inner plating can be performed as described later. In this embodiment, there are three protruding tubes, but the number of protruding tubes is not limited to three. Furthermore, it is not always necessary that the guide shaft and the plurality of projecting tubes are aligned.

  FIG. 5 shows an example of an electrolytic plating line. Liquid tanks 51 to 67 for performing each processing step are installed side by side, and a transport line 72 for transporting the immersion holder 21 is installed thereabove. Further, a control panel 71 for controlling various conditions of the transfer line 72 and each liquid tank is installed. The conveyance line 72 includes an elevating device 73 for moving the immersion holder 21 up and down, and a connecting part 74 for connecting the immersion holder 21 (the immersion holder 21 and the connecting part 74 other than on the semi-gloss tank 59, The lifting device 73 is omitted and not shown). By sequentially performing the treatment in each liquid tank, electrolytic plating (for example, nickel chrome plating or the like) is performed on the cap nut 1 as a bag-like workpiece.

  First, in a load / unload process (station) (not shown), the cap nut 1 is attached to the protruding tube 25 of the immersion holder 21 so that the opening faces downward. Then, the immersion holder 21 having the cap nut 1 mounted on the protruding tube 25 is connected to the conveyance line 72 and is immersed in the respective liquid tanks while being conveyed along the cyclic conveyance path.

  The circular transport path 72 is such that an endless track such as a chain is circulated by a driving device such as a motor. The connecting portion 74 and the lifting device 73 of the circular conveyance path 72 circulate along the cyclic conveyance path 72.

  A certain immersion holder 21 is intermittently sent along the circulating conveyance path 72, stops on each liquid tank, descends, and is immersed in the liquid tank. And it is pulled up from a liquid tank and sent to the next liquid tank. Electrolytic plating is performed on the cap nut attached to the immersion holder 21 by making a round of each liquid tank by advance, stop, descend, rise and advance. After these steps are completed, the load / unload station is returned to, and the dipping holder 21 together with the cap nut 1 is removed from the connecting portion 74. Instead, another dipping holder 21 that holds a large number of untreated cap nuts 1 is used. Is attached to the connecting portion 74.

  Next, each step will be described. Prior to the electrolytic plating process, a pre-process such as degreasing is performed. The main ones are a degreasing process in the degreasing tank 51, an electrolysis (scale removal) process in the cathodic acid electrolytic tank 52, a pickling process in the pickling tank 54, an electrolytic degreasing (activation) process in the anodic electrolytic degreasing tank 56, and neutralization. This is a neutralization step in the tank 57. Between these, washing tanks 53, 55, and 58 are disposed and cleaned. When the pre-process is completed, a plating process is subsequently performed. The plating process is performed by a semi-gloss tank 59, a Tri Ni tank 60, a gloss Ni 61, a Joule Ni tank 62, and a chromium tank 64. Moreover, it wash | cleans with the water-washing tanks 63,65,66, and is dried with the drying tank 67, and the processed nut is removed by the load / unload station (not shown), An unprocessed container nut Is installed. That is, the immersion holder 21 is intermittently moved and repeatedly immersed in each of the liquid tanks 51 to 66 and various processes are performed. When the intermittent movement is stopped, the respective immersion holders 21 are lowered at the same time, so that steps such as degreasing, washing, and plating are performed in parallel.

  Here, paying attention to one immersion holder 21, the respective steps for the plurality of cap nuts held thereon will be described in order. At the load / unload station, a large number of cap nuts supplied to the process line (circular conveyance path) via the immersion holder 21 are moved forward from the station by a certain amount and stopped. Alkaline degreasing is performed by dipping (lowering) in (degreasing layer 51). Next, after being pulled up (raised) and moved forward by a certain amount, the cathodic acid electrolysis step is performed in the electrolytic cell 52 to remove the scale generated in the cap nut by heat treatment (expand the scale). Subsequently, the water is pulled up (raised), moved forward by a certain amount, and then immersed (lowered) in the water rinsing tank 53, and the water washing step 53 is performed. After the rinsing, the cap nut is lifted (together with the immersion holder 21) and moved forward by a certain amount, and this time the cap nut is immersed (lowered) in a sulfuric acid solution or the like (pickling bath 54).

  Then, the cap nut is immersed in a predetermined alkaline solution (anodic electrolytic degreasing bath 56) in order to improve the plating after the sulfuric acid solution and the like are washed in the washing bath 55 in the same washing step as described above. Then, an anodic electrolytic degreasing step for activating the surface is performed. Furthermore, it passes through the neutralization process (neutralization tank 57) and the water washing process (water washing tank 58) similar to the above to reach the plating process.

  In the plating step, nickel plating is performed in each of the semi-gloss tank 59, the tri-Ni tank 60, the gloss Ni tank 61, and the joule Ni tank 62. A large number of cap nuts are immersed (lowered) in the plating tank 57 while being held by the immersion holder 21, and a plating layer is formed on the cap nut. In the semi-gloss tank 59, as will be described later, inner plating and outer plating are performed. In each of the subsequent Ni tank 60, gloss Ni tank 61, and Joule Ni tank 62, outer plating is performed.

  By such a plating process, semi-gloss plating can be applied to the inner surface and bright plating can be applied to the outer surface. Since the outer surface can be glossy finished, a decorative effect can be secured. That is, the inner surface and the outer surface can be finished as different plating layers. In addition, since the entire inner surface can be plated, not only a rust prevention effect can be obtained on the inner surface, but the inner surface can be thinly finished with semi-gloss plating, so that it is easy to ensure the accuracy of the screw.

  When this plating step is completed, the plate is moved forward by a certain amount, and then immersed in the water rinsing tank 63 and washed with water. And it is further immersed in the chromium tank 64, and chromium plating is given. Subsequently, the baths 65 and 66 in the washing step are reached, where the plating solution is washed.

  The use of the immersion holder 21 is not necessarily limited to the plating process as described above. If necessary, a partial plating process can be omitted, or a further process can be performed.

  The process in the electrolytic plating line using the immersion holder 21 will be described with reference to FIG. The cap nut 1 held by the immersion holder 21 is sequentially immersed in the liquid tank in the pretreatment process, the surface is cleaned, and after being washed in the water washing tank 58, it is moved to the semi-gloss tank 59 in the plating process. In the semi-gloss tank 59, inner plating and outer plating are performed. As shown in (a), the immersion holder 21 moved onto the semi-gloss plating tank 59 is lowered and immersed in the semi-gloss plating tank 59 as shown in (b). The semi-gloss plating tank 59 is provided with a flow assisting tool 85 having a nozzle 86. A flow aid is shown in FIG. The flow assisting tool 85 has a plurality of nozzles 86 on the upper surface. The nozzle 86 is formed with a through hole (not shown), and the through hole is connected to a pipe 87 connected to the lower surface of the flow assisting tool 85. Then, as shown in FIG. 6, the pipe 87 is connected to the pump 75 from the lower surface of the flow assisting tool 85.

  As shown in FIG. 6B, the through hole 28 (see FIG. 3) of the base portion 27 of the immersion holder 21 contacts the nozzle 86 formed on the upper surface of the flow assisting tool 85. When inner plating is performed, the sliding plate 26 is set at the raised position.

  The position of the sliding plate 26 of the inner plating and outer plating immersion holder 21 in the semi-gloss tank 59 will be described with reference to FIG. Internal plating is applied on the left side of the figure, and external plating is applied on the right side. After the cap nut 1 is washed in the water washing tank 58 as shown in FIG. 5A, first, the sliding plate 26 is moved up to the front part (left side of the figure) of the semi-gloss tank 59 and the base part 27 is penetrated. In a state where the hole 28 is in contact with the nozzle 86 of the flow assisting tool 85, inner plating is applied to the cap nut 1. As shown in the figure, the stopper 37 may be provided in the liquid tank, and the sliding plate 26 may be placed on the stopper 37 so that the sliding plate 26 is in the raised position. Alternatively, the immersion holder 21 may be provided with a driving device such as a motor and moved up and down. These are support member relative position conversion devices. FIG. 4B is an enlarged view of the tip portion of the protruding tube 25. When the sliding plate 26 is in the raised position, the tip portion of the protruding tube 25 is not in contact with the inner surface of the cap nut 1 as shown on the left side of the drawing. In this state, inner plating can be performed. Subsequently, as shown on the right side of (a), the outer surface plating is applied to the cap nut 1 with the sliding plate 26 in a lowered position at the rear part (right side of the drawing) of the semi-gloss tank 59. The enlarged view of the front-end | tip part of a protruding tube is shown on the right side of (b). When the sliding plate 26 is in the lowered position, the tip portion of the protruding tube 25 is in contact with the inner surface of the cap nut 1 as shown in the figure. In this state, a voltage can be applied to perform external plating. The sliding plate 26 is lowered at the front part (left side in the figure) and the sliding plate 26 is raised at the rear part (right side in the figure), and plating is performed in the order of outer plating and inner plating. Also good.

  The voltage application in the case of performing a plating process can be performed by forming a voltage application section that becomes an energization device as shown in FIG. (A) is a figure for demonstrating the electrode application part of the semi-gloss tank 59. FIG. In the front part (left side in the figure) of the semi-gloss tank 59, inner plating is performed, and in the rear part (right side in the figure), outer surface plating is performed. The voltage application units 76 and 78 are negative voltage application units that can apply a negative voltage, and the voltage application unit 77 is a positive voltage application unit that can apply a positive voltage. Then, the immersion holder 21 is installed in the voltage application units 76, 77, 78.

  As shown in FIG. 9 (b), when inner plating is performed, the immersion holder 21 is installed in the voltage application units 76 and 77. A negative voltage is applied from the voltage application unit 76 to the support shaft 23a by the power line 79a. Further, a positive voltage is applied from the voltage application unit 77 to the support shaft 23b by the power supply line 79b.

  The inner plating process will be described with reference to FIG. When the inner plating is performed, the sliding plate 26 is set to the raised position. As a result, the head surface 6 of the bag-shaped space of the cap nut 1 and the tip surface 29 of the protruding tube 25 are not in contact with each other and have a gap. In this state, it is immersed in the semi-gloss tank 59, and the immersion holder 21 is installed in the voltage application sections 76 and 77 as shown in FIG. 9, and the negative is supported from the one support shaft 23a to the guide shaft 24a, and the other support is supported. A positive voltage is applied from the shaft 23b to the guide shaft 24b. The guide shaft 24 a and the base portion 27 are electrically insulated by the insulating portion 11. Further, the sliding plate 26 and the guide shaft 24 b are electrically insulated by the insulating portion 13. As a result, a negative voltage is applied to the outer surface of the cap nut 24 from the guide shaft 24 a and the sliding plate 26. Further, a positive voltage is applied to the protruding tube 25 from the guide shaft 24 b and the base portion 27. Since the cap nut 1 is negative and the protruding tube 25 inserted into the bag-like space is applied positively, the inner surface of the cap-like nut 1 is plated. If an external anode is installed and the anode is energized, the outer plating can be performed simultaneously with the inner plating.

  If the cap nut is simply immersed in the plating solution 48 while being held by the immersion holder 21, the inner surface is not sufficiently plated because a gas such as air is present in the bag-like space 5 of the cap nut 1. . Therefore, when inner plating is performed, as shown in FIG. 11A, the gas or liquid in the bag-like space 5 is sucked by a pump 75 as a negative pressure suction device connected to the protruding tube 25 and the flow assisting tool 85. To do. By sucking the gas in the bag-like space 5, the plating solution 48 in the liquid tank flows into the bag-like space and can fill the bag-like space. That is, a voltage for electrolytic plating is applied while flowing the plating solution by suction. Or you may make it apply a voltage after making it flow. Conventionally, since the plating solution 48 does not penetrate into the flange portion of the bag-like space due to the gas filled in the bag-like space 5, the plating process can be performed only around the opening of the bag-like space. The bag-like space 5 can be filled with the plating solution 48 by sucking into the bag nut, and a positive electrode (protruding tube 25) is disposed opposite to the inner surface of the bag nut 1 so that a sufficient current flows through the inner surface of the bag nut. Therefore, the entire inner surface of the cap nut 1 can be plated. When the suction is further continued, the plating solution 48 flows, and a favorable plating process can be performed. Alternatively, as shown in (b), as a pressure discharge device, for example, a pump may be used, and the plating solution 48 may be ejected from the protruding tube 25 into the bag-like space of the cap nut to perform the plating process. By spraying, the entire inner surface can be plated. In this case, since pressure is applied to the inner surface, the cap nut 1 may be forcibly fixed by holding the head portion 1 of the cap nut with a fixing member 41 as shown in FIG. Or you may make it hold | suppress the flange part 7 with the fixing member 42, as shown in FIG.12 (b). In FIG. 11, the protruding tube is inserted into the bag-like space, but the same processing may be performed with the end positioned near the opening as shown in FIG. Also in this case, the inside of the bag-like space 5 can be filled with the plating solution 48, and a sufficient current can flow through the inner surface of the cap nut 1.

  Next, outer plating will be described with reference to FIG. When external plating is performed, the sliding plate 26 is set at the lowered position. Then, a negative voltage is applied to the support shaft 23b, the guide shaft 24b, the base portion 27, and the protruding tube 25 by the voltage application unit 78 (see FIG. 9). Further, a negative voltage is applied to the support shaft 23 a, the guide shaft 24 a, the sliding plate 26, and the base portion 27 from the voltage application unit 78. When the sliding plate 26 is in the lowered position, the head surface 6 of the bag-like space of the cap nut 1 is in contact with the tip surface 29 of the protruding tube 25. For this reason, a negative voltage is applied from the protruding tube 25 to the cap nut 1. Further, as shown in FIG. 15, an anode 91 is installed in the semi-gloss tank 59. In this way, the outer surface of the cap nut 1 can be plated by setting the cap nut 1 side to a negative voltage and the anode side to a positive voltage.

  Further, FIG. 16 shows an example in which an auxiliary anode 92 is installed in addition to the anode 91 in the liquid tank. FIG. 16 shows the liquid tank as viewed from above. The anode 91 which is a positive electrode part is installed facing both sides in the liquid tank. Auxiliary anodes 92, which are a plurality of auxiliary electrode portions, are installed between the anodes. The cap nuts 1 held by the immersion holder 21 are respectively installed in the area surrounded by the auxiliary anode. In this arrangement, from one anode 91, the first auxiliary electrode portion row, the first plating object row, the second auxiliary electrode portion row, the second plating object row, the third auxiliary electrode portion row, etc. The partial rows and the plated object rows are alternately arranged, the n + 1 auxiliary electrode portion row (n is a positive integer) next to the nth plated material row, and the other anode 91.

  And each auxiliary electrode part row | line | column is located in the 1/2 pitch point of the pitch between row | line | columns of a to-be-plated thing row | line | column (work row | line | column), and each electrode pitch of an auxiliary electrode part row | line | column and to-be-plated thing row | line | column (work row | line | column) ) Between the workpieces is shifted by a half pitch. That is, the auxiliary electrode portion is formed at a symmetrical position with respect to each workpiece. Further, paying attention to one cap nut 1a and viewing the surrounding auxiliary electrode portions, auxiliary electrode portions (auxiliary anodes) 92a, 92b, 92c, and 92d are arranged at the four corners of the rectangle. That is, the auxiliary electrode portion 92a and the auxiliary electrode portion 92d are disposed at the target position with respect to the cap nut 1a, and similarly, the auxiliary electrode portion 92b and the auxiliary electrode portion 92c are disposed at the target position with respect to the cap nut 1a. ing. Each auxiliary electrode part is arranged in the position which does not interfere with the immersion movement of the plating solution tank to the plating solution tank.

  Then, a positive voltage is applied to the anode 91 and the auxiliary anode 92, and a negative voltage is applied to the support shaft 23b, the guide shaft 24b, the base portion 27, the protruding tube 25, and the cap nut 1 by the voltage application unit 78 as described above. Is done. In this manner, the outer surface of the cap nut 1 can be plated. Since the auxiliary anode 92 is installed so as to surround the cap nut 1, the current can flow stably and uniformly, and the outer surface can be plated with a more uniform thickness.

  FIG. 17 shows a cross-sectional view of the liquid tank. As shown in FIG. 16, anodes 91 are installed on one side and the other side of the liquid tank, and an auxiliary anode 92 is installed between the anodes 91. The cap nuts 1 and the auxiliary anodes 92 soaked by the jig are alternately arranged. As a result, a voltage can be uniformly applied to the cap nut, and the plating process can be efficiently performed so as to have a plating thickness with little variation. Moreover, you may make it an auxiliary electrode part (auxiliary anode) install in an immersion holder, without installing in a plating tank.

  Another method of inner plating will be described with reference to FIG. As shown in (a), the cap nut 1 held by the sliding plate 126 of the immersion holder is moved onto the plating solution 48. Then, the plating solution is ejected from the protruding tube 125 on the liquid surface. By spraying the plating solution, the entire inner surface of the cap nut 1 can be plated. At this time, the head of the cap nut 1 and the like may be suppressed and fixed so that the cap nut does not move due to the ejection pressure. When the inner plating process is completed, as shown in (b), the cap nut is dipped in the plating solution to perform outer plating.

  The processing liquid circulation method will be described with reference to FIG. FIG. 19 shows a plating bath 151, for example a semi-gloss bath. The plating tank 151 is provided with an outflow pipe 135, a pump 75, and an inflow pipe 136. The cap nut 1 is held by the immersion holder and immersed in the plating tank 151 so that the tip of the outflow pipe 135 is inserted into the bag-like space of the cap nut 1. Alternatively, the protruding tube may be inserted into the bag-like space like the above-described immersion holder 21 and connected to the outflow tube 135 via the flow assisting device 85. In this state, a voltage is applied to the cap nut 1 to perform plating. At this time, gas or liquid in the bag-like space of the cap nut 1 is sucked by the pump 75. The outflow pipe 135 and the pump 75 and the sucked gas or liquid are introduced into the plating tank 151 through the inflow pipe 136. Thereby, a flow occurs in the treatment liquid in the plating tank 151, and the plating efficiency can be increased.

  The present invention can be applied to a cap nut 301 as shown in FIG.

  In order to confirm the above effects, plating treatment was performed, and the thickness of the plating layer of the cap nut was measured. It was confirmed that the inner surface was sufficiently covered by plating over the entire area.

  Furthermore, using an anode and an auxiliary anode, the outer plating was applied to the nut, and the plating thickness was measured using an overcurrent nondestructive film thickness meter. There was little variation in the measurement location, and almost the same film thickness could be obtained. From the above tests, it was confirmed that when the anodes on both sides and the auxiliary anode were used, the variation in the outer plating film thickness was small and the plating treatment was performed uniformly.

  The suction or ejection of gas or liquid in the bag-shaped space in the above inner plating, the immersion holder, and the auxiliary anode for this purpose are not limited to nickel plating. Furthermore, if a to-be-plated object is a workpiece | work which has a bag-shaped space, it will not be restricted to a cap nut. By performing the inner surface plating and the outer surface plating in different processes, the inner surface and the outer surface can be finished in different plating layers.

A cap nut as an example of a bag-like workpiece in which an immersion holder is used. Example of immersion holder. The expanded sectional view of an immersion holder. The expansion perspective view of an immersion holder. An example of a plating line. The figure explaining operation | movement of the immersion holder in a plating processing line. The figure explaining a flow aid. The figure explaining the use condition of the immersion holder in inner surface plating and outer surface plating. The figure explaining the voltage application part of a liquid tank. The figure explaining the position of a sliding plate and voltage application in inner surface plating. The figure explaining the attraction | suction or discharge of the gas and liquid for performing inner surface plating. The figure explaining fixation of a cap nut. The figure which shows the case where a protruding tube is located in the opening part vicinity. The figure explaining the position of a sliding plate and voltage application in outer surface plating. The figure explaining the anode in a liquid tank. The figure explaining an anode and an auxiliary anode. Sectional drawing of the liquid tank which has arrange | positioned the auxiliary anode. The figure explaining the plating process by discharge of a process liquid. The figure explaining the circulation of a process liquid. The figure explaining the conventional immersion holder and plating process. The figure of the cap nut as other examples of a bag-like work.

Explanation of symbols

1 Cap nut 21 Immersion holder 24 Guide shaft 25 Projection tube 26 Sliding plate 27 Base part 59 Semi-gloss tank 72 Transfer line 75 Pump 76, 77, 78 Voltage application part 91 Anode 92 Auxiliary anode

Claims (7)

A bath for storing a plating solution for processing an object to be plated;
A negative voltage application unit that is installed in the liquid tank and applies a negative voltage to the object to be plated;
A positive electrode part installed in the liquid tank and applied with a positive voltage;
A plurality of auxiliary electrode portions installed at positions in the liquid tank surrounding the immersed object to be plated;
An electroplating apparatus characterized in that a plating process is performed by immersing the object to be plated in a plating solution in the liquid bath.   2. The electrolytic plating apparatus according to claim 1, wherein the positive electrode portion is installed on one surface of the liquid tank and the other surface facing the positive electrode portion, and a plurality of the auxiliary electrode portions are installed between the positive electrode portions.   A plurality of the objects to be plated are held on the same surface by a holder and immersed in the liquid tank, and the auxiliary electrode is on the same surface as the objects to be plated and symmetrically with respect to the objects to be plated. The electroplating apparatus of Claim 1 or 2 with which the part is installed.   The said to-be-plated object is hold | maintained with a holder, the to-be-plated object is immersed in the said liquid tank with a holder, and a negative voltage is applied to the said to-be-plated object via the said holder. The electroplating apparatus of any one of Claims.   From the one positive electrode portion, the auxiliary electrode portion row and the plated object row are alternately arranged, the n + 1 auxiliary electrode portion row (n is a positive integer) next to the nth plated row, The electroplating apparatus of any one of Claims 1 thru | or 4 located in a line with the said other said positive electrode part. A holder for holding workpieces, which are individual objects to be plated, at predetermined intervals so as to form two or more linear and parallel rows is immersed in the plating bath together with the multiple rows of workpieces held there. Assuming that the plurality of workpiece rows are substantially parallel to the liquid surface of the plating bath,
An auxiliary electrode row in which a plurality of auxiliary electrodes are arranged at a predetermined interval is arranged on both sides of each row in the plurality of workpiece rows so as to be parallel to the workpiece row, and each auxiliary electrode row has a pitch between the workpiece rows. The pitch between the rows of the auxiliary electrode rows and the pitch between the workpiece rows are made equal to each other so as to be located at a ½ pitch point, and the pitch between the workpieces in the workpiece row and the inside of the auxiliary electrode row The pitch between the electrodes of the auxiliary electrode is equal to each other, and the pitch between the electrodes of the auxiliary electrode row and the pitch between the workpieces of the workpiece row are shifted by a half pitch. / 2 When each auxiliary electrode of the auxiliary electrode row is positioned in a staggered manner at a pitch point, and attention is paid to one piece of work, it is on a rectangular diagonal line centering on the one piece. The auxiliary electrode is arranged in the plating solution tank at a position where the auxiliary electrode does not interfere with the immersion movement of the holder into the plating solution tank so that the auxiliary electrode is located at four positions that are equidistant from the center corresponding to the four corners. An electroplating apparatus characterized by comprising: The electroplating apparatus according to claim 1, wherein the object to be plated is a bag-shaped workpiece having a bag-shaped space, and the bag-shaped workpiece is plated.

Images