JP2005350697A - Electroplating method and electroplating device for box-shaped work - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroplating method and an electroplating device for a box-shaped work by which, in the case the inside face of a box-shaped work such as a box nut is subjected to surface treatment by dipping the same into a liquid bath, a satisfactory plating film is formed. <P>SOLUTION: A box-shaped work having a box-shaped space is dipped into a plating liquid of an electroplating bath in such a manner that an opening part thereof turns downward, a suction tube is inserted into the box-shaped space of the box-shaped work from the opening part or the edge part of the suction tube is located in the vicinity of the opening part, and gas present in the box-shaped space and/or fluid as the plating liquid is sucked with the suction tube under negative pressure. By the suction of the gas, the plating liquid progresses into the box-shaped space and is filled therein, and by plating treatment under voltage, a plating film is formed at the inside face of the box-shaped space in the box-shaped work. Alternatively, the plating liquid is discharged with the suction tube so as to form the plating film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrolytic plating method and an electrolytic plating apparatus for a bag-like workpiece.

  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. 19 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. 19 (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 supporting collar 202 is formed in multiple stages as in the immersion holder 201 of FIG. 19, 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 electrolytic plating method and an electrolytic plating apparatus for a bag-like workpiece that forms a good plating film when the inner surface of a bag-like workpiece such as a cap nut is subjected to surface treatment by being immersed in a liquid tank. Is to provide.

Means for Solving the Problems and Effects of the Invention

The electrolytic plating method of the bag-shaped workpiece of the present invention for solving the above problems is as follows.
A bag-shaped workpiece having a bag-shaped space is immersed in the plating solution of the electrolytic plating tank with the opening facing downward, and a suction tube is inserted into the bag-shaped space of the bag-shaped workpiece from the opening or in the vicinity of the opening. Position the end of the suction tube, suck the gas and / or plating fluid present in the bag-like space with the suction tube under negative pressure, and allow the plating solution to flow into the bag-like space through the opening. In this case, a voltage for electroplating is applied to the bag-shaped workpiece, including the inner surface of the bag-shaped space, and a plating film is formed with a plating solution.

  Conventionally, when the bag-like workpiece opening is immersed in the plating solution with the opening facing downward, the bag-like space contains a gas such as air, and the plating solution does not enter the bag-like space. It was difficult to plate the entire inner surface of the space. By inserting the suction pipe into the opening by the above method or by positioning the end of the suction pipe in the vicinity of the opening and sucking the gas or plating solution in the bag-like space, the plating solution is put in the bag-like space. Since it flows and enters and the bag-shaped space can be filled with the plating solution, a plating film can be formed over the entire inner surface. Since it is made to flow, the efficiency of the plating process is improved, and the plating process can be performed in a short time.

Furthermore, the electrolytic plating method of the bag-like workpiece of the present invention for solving the above-described problems is as follows.
A bag-shaped workpiece having a bag-shaped space is immersed in the plating solution of the electrolytic plating tank with the opening facing downward, and a discharge pipe is inserted into the bag-shaped space of the bag-shaped workpiece from the opening or in the vicinity of the opening. The end of the discharge pipe is positioned, the plating solution pressurized from the discharge pipe is discharged into the bag-shaped space, and the gas and / or plating solution existing in the bag-shaped space is made to flow through the opening. Alternatively, after flowing, a voltage for electrolytic plating is applied, and the plating film is formed with a plating solution including the inner surface of the bag-like space on the bag-like workpiece.

  Insert the discharge pipe from the opening of the bag-like workpiece immersed in the plating solution with the opening facing downward as described above, or position the end of the discharge pipe in the vicinity of the opening, and form the bag from the discharge pipe. By discharging the plating solution into the space, gas such as air in the bag-like space is expelled, and the plating solution can enter the entire region of the bag-like space to fill the entire interior of the bag-like space with the plating solution. . Thereby, the whole inner surface can be plated.

  When the plating solution is discharged from the discharge pipe, the bag-shaped workpiece may move due to the discharge pressure. Therefore, the plating solution is discharged from the discharge pipe in a state where the bag-like workpiece is restrained from the outside of the bag-like workpiece and the movement thereof is prevented. Restraining from the outside means, for example, suppressing the head that is a non-opening portion on the side opposite to the opening portion or suppressing the outer flange portion. By doing so, the bag-like workpiece can be fixed, and the movement of the bag workpiece can be prevented by the jet of the plating solution from the discharge pipe.

  Then, support the bag-like work in a state where the head surface opposite to the opening of the bag-like space of the bag-like work and the end of the suction pipe or the discharge pipe are not in contact with each other. By sucking the fluid to be filled or discharging the plating solution from the discharge pipe, a plating film is formed by electrolytic plating including the inner surface of the bag-shaped space on the bag-shaped workpiece. Thus, the fluid flow can be made smooth by making the tip of the suction tube or the discharge tube not contact the inner surface of the bag-like workpiece. Note that the tip portion may be in contact with the inner surface of the bag-shaped workpiece as long as the tip portion is insulated from the bag-shaped workpiece and the fluid can flow.

  Further, while applying a negative voltage to the bag-like workpiece, the fluid filling the bag-like space is sucked from the suction pipe, or the plating solution is discharged from the discharge pipe. Thus, a plating process can be performed by applying a negative voltage to a bag-shaped workpiece.

  The bag-shaped workpiece is a bag nut in which one opening of the nut body is covered in a bag shape with a cap portion. More specifically, for example, a hub nut. As long as one opening is covered with a cap in a bag shape, the inner surface can be plated by the above method without being limited thereto.

The electrolytic plating apparatus for bag-like workpieces of the present invention for solving the above problems is as follows.
A plating tank for storing a plating solution in which a bag-shaped workpiece having a bag-shaped space is immersed;
In the plating tank, a workpiece holding member that holds the bag-like workpiece in a state in which the opening portion thereof is directed downward,
A suction tube that is inserted into the bag-like space of the bag-like workpiece immersed in the plating solution in a state of being held by the workpiece holding member, or whose end is positioned in the vicinity of the opening;
A negative pressure suction device for sucking a fluid that is a gas and / or a plating solution present in the bag-like space into a suction pipe under a negative pressure, and causing the plating solution to flow through the opening in the bag-like space;
An energizing device for applying a voltage for electrolytic plating while flowing or after flowing.

  With the above configuration, the bag-like workpiece can be held by the workpiece holding member, immersed in the plating solution, and the gas or plating solution present in the bag-like space of the bag-like workpiece can be sucked from the suction pipe. As a result, the plating solution in the plating tank newly enters the bag-shaped space to fill the bag-shaped space, and the inner surface forming the bag-shaped space can be plated.

Moreover, the electroplating apparatus for the bag-like workpiece of the present invention is:
A plating tank for storing a plating solution in which a bag-shaped workpiece having a bag-shaped space is immersed;
In the plating tank, a workpiece holding member that holds the bag-like workpiece in a state in which the opening portion thereof is directed downward,
A discharge pipe inserted into the bag-like space of the bag-like workpiece immersed in the plating solution in a state of being held by the workpiece holding member, or having an end positioned in the vicinity of the opening;
A pressure discharge device that discharges the pressurized plating solution from the discharge pipe to the bag-shaped space and causes the gas and / or the plating solution present in the bag-shaped space to flow through the opening;
An energizing device for applying a voltage for electrolytic plating while flowing or after flowing.

  With the above configuration, the bag-like workpiece is held by the workpiece holding member, immersed in the plating solution, and the plating solution is ejected into the bag-like space of the bag-like workpiece, thereby expelling the gas and plating solution present in the bag-like space. A new plating solution can enter the bag-like space to form a plating film on the inner surface forming the bag-like space.

  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 tank 61, a Joule Ni tank 62, and a chromium tank 64. Moreover, it wash | cleans by the water-washing tanks 63,65,66, and is dried by the drying tank 67, and the processed nut is removed by the load / unload station (not shown), and an untreated bag 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, it is pulled up (raised) from here, moved forward by a certain amount, and then immersed (lowered) in the water rinsing tank 53 to carry out the water washing step. 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 can apply a negative voltage, and the voltage application unit 77 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 cap nut 1 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 of the bag-like space due to the gas filled in the bag-like space 5, the plating treatment can only be performed around the opening of the bag-like space 5, By sucking in such a manner, the bag-like space 5 can be filled with the plating solution 48, and a positive electrode (protruding tube 25) is arranged facing the inner surface of the bag nut 1 so that a sufficient amount of 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 to eject the plating solution 48 from the protruding tube 25 into the bag-like space 5 of the cap nut and 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 3 of the cap nut 1 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. Anodes 91 are placed opposite to each other in the liquid tank. A plurality of auxiliary anodes 92 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. 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.

  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. 18 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.

  Note that the present invention can be applied to a cap nut 301 as shown in FIG. 20 as a bag-like workpiece.

  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. 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 (9)

  A bag-shaped workpiece having a bag-shaped space is immersed in a plating solution in an electrolytic plating tank with its opening facing downward, and a suction tube is inserted into the bag-shaped space of the bag-shaped workpiece from the opening or the opening An end of a suction pipe is positioned in the vicinity, and a gas and / or a fluid that is a plating solution existing in the bag-like space is sucked by the suction pipe under a negative pressure, and the plating solution is put into the bag-like space by the opening. A voltage for electroplating is applied while flowing through or after flowing, and the plating film is formed by the plating solution including the inner surface of the bag-like space on the bag-like work. Electrolytic plating method for bag-like workpieces.   A bag-shaped workpiece having a bag-shaped space is immersed in a plating solution in an electrolytic plating tank with its opening facing downward, and a discharge pipe is inserted into the bag-shaped space of the bag-shaped workpiece from the opening or of the opening. The end of the discharge pipe is positioned in the vicinity, the plating solution pressurized from the discharge pipe is discharged into the bag-shaped space, and the gas and / or plating solution present in the bag-shaped space is discharged through the opening. A bag shape characterized by applying a voltage for electrolytic plating while flowing or flowing, and forming a plating film with the plating solution including the inner surface of the bag-shaped space on the bag-shaped workpiece. Electrolytic plating method for workpieces.   The electrolytic plating method for a bag-shaped workpiece according to claim 2, wherein the plating solution is discharged from the discharge pipe in a state where the bag-shaped workpiece is restrained from the outside of the bag-shaped workpiece and prevented from moving.   The suction pipe supports the bag-like work in a state where the head surface of the bag-like work opposite to the opening of the bag-like space does not contact the suction pipe or the end of the discharge pipe. By sucking the fluid filling the bag-shaped space from or by discharging the plating solution from the discharge pipe, the bag-shaped workpiece includes the inner surface of the bag-shaped space and is plated by electroplating. The method of electrolytic plating of a bag-like workpiece according to any one of claims 1 to 3, wherein:   5. The fluid according to claim 1, wherein the fluid filling the bag-like space is sucked from the suction pipe or the plating solution is discharged from the discharge pipe while applying a negative voltage to the bag-like work. The electrolytic plating method for the bag-like workpiece according to Item.   The method for electroplating a bag-like workpiece according to any one of claims 1 to 5, wherein the bag-like workpiece is a bag nut in which one opening of a nut body is covered with a cap at a bag shape.   The method for electrolytic plating a bag-shaped workpiece according to any one of claims 1 to 6, wherein the bag-shaped workpiece is a hub nut. A plating tank for storing a plating solution in which a bag-shaped workpiece having a bag-shaped space is immersed;
In the plating tank, a work holding member that holds the bag-shaped work in a state in which the opening of the bag-shaped work faces downward,
A suction tube inserted into the bag-like space of the bag-like workpiece immersed in the plating solution in a state of being held by the workpiece holding member, or having an end positioned in the vicinity of the opening; ,
A negative pressure suction device for sucking a fluid that is a gas and / or a plating solution existing in the bag-like space into the suction pipe under a negative pressure and causing the plating solution to flow through the opening in the bag-like space; ,
A current-carrying device that applies a voltage for electroplating while flowing or after flowing;
An electroplating apparatus for bag-like workpieces, comprising: A plating tank for storing a plating solution in which a bag-shaped workpiece having a bag-shaped space is immersed;
In the plating tank, a work holding member that holds the bag-shaped work in a state in which the opening of the bag-shaped work faces downward,
A discharge pipe inserted into the bag-like space of the bag-like workpiece immersed in the plating solution in a state of being held by the workpiece holding member, or having an end positioned in the vicinity of the opening; ,
A pressure discharge device that discharges the pressurized plating solution from the discharge pipe into the bag-shaped space, and causes the gas and / or the plating solution present in the bag-shaped space to flow through the opening;
A current-carrying device that applies a voltage for electroplating while flowing or after flowing;
An electroplating apparatus for bag-like workpieces, comprising:

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