JP2010007158A - Surface treatment line for sack-shaped workpiece and surface treatment method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment line for a sack-shaped workpiece, which has an improved technology of applying a rust preventive oil so as to optimize the amount of the rust preventive oil to be applied on the surface of the plated film in the surface treatment for the sack-shaped workpiece, and to provide a surface treatment method therefor. <P>SOLUTION: The surface treatment line which forms a predetermined plated film on the sack-shaped workpiece having a sack-shaped space 5 while transporting the sack-shaped workpiece and then applies a rust preventive oil to the plated film includes: a rust preventive oil immersion section which immerses the sack-shaped workpiece in such an attitude of the sack-shaped space 5 as to make the aperture 6 direct upward; a workpiece attitude conversion section which converts the attitude of the sack-shaped workpiece so that the aperture 6 of the sack-shaped space 5 directs downward, when the sack-shaped workpiece is raised, and then makes the rust preventive oil flow down by its own weight; and the first oil-removing section which is arranged in the sack-shaped space 5 of the sack-shaped workpiece of which the attitude has been converted, sucks air in the sack-shaped space 5 together with the rust preventive oil which deposits in the sack-shaped space 5, or jets a compressed air into the sack-shaped space to make the rust preventive oil depositing therein scattered or further sucks air in the sack-shaped space 5 together with the rust preventive oil which remains in the space after the compressed air has been jetted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface treatment line and a surface treatment method for a bag-like workpiece for performing a plating treatment or the like on a bag-like workpiece such as a cap nut.

  A bag-like work such as a cap nut as a hub nut for fixing a vehicle wheel to the hub is subjected to a surface treatment such as plating for decoration or rust prevention. In such surface treatment, a workpiece holding jig having a tree branch shape is used to convey the bag-like workpiece to each processing step (see Patent Document 1).

  A bag-like workpiece is inserted and held in each branch of the workpiece holding jig so that the elastic force of the spring acts, and the bag-like workpiece in such a state is degreased, alkaline, acid, or multilayered. Surface treatments such as plating treatment are performed by carrying out each treatment step in various plating tanks for forming a plating film, a washing tank between each treatment tank, and the like in a series of flows.

Japanese Patent Laid-Open No. Sho 62-127498

  And in such a surface treatment process, the rust preventive oil is applied to the surface of the bag-like workpiece on which the plating treatment has been completed, and is shipped from the factory. However, if the amount of rust-preventive oil applied is greater than necessary, the film of rust-preventive oil on the surface of the cap nut's female thread will become thick, affecting the tightening torque during use and failing to tighten with the original tightening torque. Also, the development of anti-rust oil coating technology to solve problems such as excess rust preventive oil adhering to other related equipment and affecting the operation of the equipment in the handling process in the subsequent packaging process. It is desired.

  The object of the present invention is to provide a bag-like workpiece surface treatment line and surface treatment with improved rust-preventive oil application technology so as to optimize the amount of rust-preventive oil applied to the plating surface in the surface treatment of the bag-like workpiece. It is to provide a method.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above problems, the surface treatment line of the bag-shaped workpiece of the present invention is such that after a predetermined plating film is formed on the bag-shaped workpiece having a bag-shaped space, a rust preventive oil is applied to the plating film. In the surface treatment line, with the posture with the opening of the bag-shaped space facing upward, the rust-preventing oil immersion portion for immersing the bag-shaped workpiece in the rust-preventing oil; and At the time, it is disposed in the bag-shaped space of the bag-shaped workpiece that has been converted into a posture, the workpiece posture conversion portion that converts the opening of the bag-shaped space downward and the rust preventive oil flows down by its own weight, The air in the bag-like space is sucked together with the rust-preventing oil adhering thereto, or the compressed air is injected into the bag-like space to scatter the anti-rust oil adhering thereto, or Rust preventive oil that leaves the air in the bag-like space after the jet, Both the first oil removing section that sucks together and the bag-like workpiece are rotated about its central axis so that the antirust oil adhering to the outer surface of the bag-like workpiece is scattered by centrifugal force. And a second oil removing unit.

  By forming the above-described configuration, after forming a predetermined plating film, a rust preventive oil immersing step of immersing the bag-like workpiece in the rust preventive oil, and a suction step of sucking the bag-like space of the bag-like workpiece or / and It is possible to provide a surface treatment method in which the first oil removing step including the spraying step for spraying and the second oil removing step for rotating the bag-shaped workpiece to disperse the antirust oil are continued. In addition, the first oil removing unit sucks or / and sprays the bag-shaped space, further reduces the amount of oil attached to the bag-shaped space, and further scatters the rust-preventing oil on the surface of the bag-shaped workpiece by centrifugal force. Therefore, if the bag-shaped workpiece is, for example, a cap nut, the amount of the rust-preventing oil adhering to the female thread portion is reduced. An increase in tightening torque during use can be prevented, and oil adhesion to other parts during subsequent handling can also be reduced.

  In order to solve the above-mentioned problem, the suction amount sucked by the first oil removing unit of the surface treatment line of the bag-like workpiece of the present invention and the injection amount to be injected are variably controlled. Thereby, the adhesion amount of the rust preventive oil in the bag-like space of the bag-like workpiece can be optimized. Further, the second oil removing portion of the surface treatment line controls the rotational speed of the shaft rotation so that the rust preventive oil on the surface of the bag-like workpiece is formed in a film shape, Since the rust-preventive oil in the bag-shaped space and the surface of the bag-like workpiece is in the form of a film, the amount of adhesion is small and the amount of rust-preventive oil used can be reduced. It is difficult to grow, and dripping and oil adhesion to other places can be reduced.

  In order to solve the above-described problem, the suction or / and injection by the first oil removing unit is performed during the shaft rotation operation of the bag-like workpiece of the surface treatment line of the bag-like workpiece of the present invention. The process time for bag-like workpieces can be shortened, leading to improved productivity. In addition, since the suction is performed after the injection in the first oil removal step, the oil mist of the rust preventive oil generated at the time of the injection can also be removed by suction, so that the oil mist can be prevented from scattering. , Can maintain the surrounding environment.

  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 is provided with a main body 2 having a female thread portion 4 and a cap portion 3 that closes an opening opposite to the screw-in side of the male screw member of the main body 2. A bag-like space 5 is formed by a portion into which the tip of a male screw member such as a bolt enters. Such a cap nut 1 is conveyed in a series of flow for surface treatment such as cleaning, rust prevention, plating treatment, etc. after forging, further threading by rolling or cutting, welding of the cap part 3 and heat treatment. However, each process is implemented.

  FIG. 2 is a diagram showing a surface treatment line L for performing a surface treatment such as a plating treatment of the cap nut 1. In FIG. 2, the surface treatment line L starts from a workpiece supply unit 7 for supplying the cap nut 1 disposed on the line base end side La, and the surface-treated cap nut disposed on the line end side Lb. 1 and a work discharge unit 8 for discharging 1.

  Further, between the workpiece supply unit 7 and the workpiece discharge unit 8 in the surface treatment line L, various treatment liquid tanks and various treatment units for performing each surface treatment step such as plating treatment are provided. In this example, a plating process such as nickel chrome plating is applied to the cap nut 1, rust preventive oil is applied to the cap nut 1 after the plating process is completed, and discharged for subsequent processes or shipment.

  In addition, the workpiece supply unit 7 and the workpiece discharge unit 8 in the surface treatment line L are connected by a circulation conveyance path 9. The circulating transport path 9 may be any path as long as an endless track such as a chain is circulated by a driving device (not shown) such as a motor.

  As shown in FIG. 3, a work holder 10 for holding and transporting the cap nut 1 is disposed in the circulation transport path 9. The workpiece holder 10 includes a center pin 10b extending from the holder body 10a and left and right pins 10c arranged symmetrically with respect to the center pin 10b. Using these three pins, the cap nut 1 is held on the tip side. The left and right pins 10c can be elastically deformed to such an extent that the distance between them is changed, and the tip end portion is bent outward.

  When the cap nut 1 is mounted, a force is applied to the left and right pins 10c to narrow the distance between the two, and when the cap nut 1 is inserted into the bag-like space 5 through the opening 6 of the cap nut 1 The elastic deformation force is applied to the inner surface of the bag-like space 5 of the cap nut 1, and the tip is caught, so that it is not easily removed due to vibration caused by movement when transported through the circulation transport path 9.

  As shown in FIG. 4, the workpiece holder 10 holds the cap nut 1 individually, and the posture of the circulating nut 9 during the conveyance of the bag nut 1 in the circulation conveyance path 9 is set so that the opening 6 of the bag-like space 5 faces upward. The transfer movement is connected to the attitude conversion mechanism 11 that converts the opening 6 into an attitude in which the opening 6 faces downward (in this example, obliquely downward), and is controlled to move by the endless track of the circulation transfer path 9. It is connected to the body 9a.

  FIG. 5 is a conceptual diagram showing the posture inversion mechanism 11. In FIG. 5, the fixed plate 11a to which the workpiece holder 10 is fixed is connected to a drive mechanism 11b such as a cylinder or a motor that is operated by hydraulic pressure or air pressure. And the fixed plate 11a is moved by the action | operation of this drive mechanism 11b, and the attitude | position of the cap nut 1 hold | maintained with the workpiece holder 10 is changed.

  Further, as shown in FIG. 6, in the workpiece supply unit 7, the cap nuts 1 with the posture with the opening 6 facing upward are aligned (in this example, 10 are arranged, the long side is 5 rows and the short side is 2 rows) ) A rectangular transfer tray 7a that is placed and waits is disposed. The transfer tray 7a is controlled to move to the standby position X1 in the circulation conveyance path 9. As described above, when the plurality of cap nuts 1 are transferred to the circulation conveyance path 9 (standby position X1) of the surface treatment line 6, the plurality of work holders 10 are held so that the plurality of cap nuts 1 are collectively held. Is fixed in a state of being suspended from the fixing plate 11a.

  Returning to FIG. 2, in the surface treatment line L, as various treatment liquid tanks used for the surface treatment of the cap nut 1, a degreasing tank 12 for performing degreasing, a cathodic acid electrolytic tank 13 for performing scale removal, activation is performed. An anodic electrolytic degreasing tank 14, various plating tanks 15 in which nickel chrome plating is performed, and a rust preventive liquid tank 16 in which rust preventive oil is applied.

  Moreover, the plating performed in the various plating tanks 15 in which nickel chrome plating is performed is nickel plating as a lower layer, and in this case, for example, there is a semi-bright nickel plating or a bright nickel plating. It is also possible to perform semi-gloss and gloss plating sequentially in separate plating tanks. Further, a chromium plating is applied to the nickel plating layer as an upper layer.

  Moreover, it is various plating tanks 15 in the surface treatment line L, and is a chrome plating tank 15a in which chrome plating is performed so that the plating film of the cap nut 1 is nickel chrome plating; A workpiece cleaning unit 17 used for a workpiece cleaning process for cleaning the cap nut 1 formed with a predetermined plating film between the liquid tank 16 with room temperature water or warm water, and a workpiece cleaning process by the workpiece cleaning unit 17. And a workpiece drying unit 18 used in a workpiece drying process for drying the cap nut 1 having undergone the above.

  The work cleaning unit 17 is connected to a plurality of cleaning tanks 17 a for water cleaning and hot water cleaning in the circulation conveyance path 9. Moreover, the washing tank 17a of the workpiece washing unit 17 located immediately before the workpiece drying unit 18 is washed with warm water (about 40 to 50 ° C.).

  Further, the work drying unit 18 removes water droplets attached to the surface of the cap nut 1 by jetting compressed air, and water on the surface of the cap nut 1 from which water droplets have been removed by the water droplet removing device 18a. And a drying device 18b for removal.

  As shown in FIG. 7, the water droplet removing device 18 a is configured to move the bag nut 1 conveyed in a posture in which the opening 6 of the bag-shaped space 5 faces downward by the work holder 10 that holds and conveys the bag nut 1. A plurality of lower nozzles 18 a 1 for injecting compressed air toward the opening 6 of the cap nut 1 and a plurality of upper nozzles 18 a 2 for injecting compressed air toward the cap portion 3 of the cap nut 1 are provided. These nozzles are connected to a compressed air supply (not shown).

  Further, as shown in FIG. 8, the drying device 18 b includes a tunnel-shaped drying furnace 18 b 1 that allows a plurality of cap nuts 1 that are collectively conveyed by a plurality of workpiece holders 10 to pass through the circulation conveyance path 9. Has been placed. In this example, a hot air supply device 18b2 for supplying hot air of about 200 ° C. is connected to the drying furnace 18b1, and the hot air is supplied into the drying furnace 18b1 from the supply port 18b3 so as to be a device using convection heat transfer drying. . In addition, a partition wall 18b4 for making the contact between the cap nut 1 and the hot air uniform is provided in the drying furnace 18b1 in a direction orthogonal to the conveying direction. In place of convection heat transfer drying, radiation heat transfer drying mainly using infrared rays can also be employed.

  As shown in FIG. 9, the rust preventive oil application part 19 having the rust preventive liquid tank 16 used in the rust preventive oil application process in which the rust preventive oil is applied is circulated downstream of the work drying part 18 in the transport direction. It is connected to the workpiece removal position X2 provided in the conveyance path 9.

  A base end side 20a of the transfer conveyance path 20 for moving the cap nut 1 is connected to the work removal position X2 outside the circulation conveyance path 9 (lower side in the figure). A rust preventive liquid tank 16 and a work rotating device 21 as a work rotating part are connected in series to the end side 20b of the transfer conveyance path 20.

  The transfer conveyance path 20 is provided with a rectangular moving tray 20c that is controlled to reciprocate between a base end side 20a and a terminal end side 20b. In addition, a rectangular temporary storage tray 8a for temporarily storing a plurality of cap nuts 1 after the drying process is disposed at the workpiece removal position X2. Further, as shown in FIG. 10, a chuck device for placing the cap nut 1 placed on the temporary placement tray 8a on a rectangular moving tray 20c waiting on the proximal end side 20a of the transfer conveyance path 20. 22 is provided. The chuck device 22 is provided with a plurality of chuck portions 22a for individually gripping the cap nuts 1. The chuck portion 22a grips the cap nut 1 by a pair of chuck claws 22b that are controlled to open and close using air pressure.

  Further, as shown in FIG. 11, there is provided a moving tray transfer machine 23 that is controlled to reciprocate between the terminal end side 20 b of the transfer transfer path 20 and the rust prevention liquid tank 16. The movable tray transporter 23 conveys the rust preventive liquid tank 16 while holding an arbitrary portion (for example, both sides on the short side or both ends on the long side) of the movable tray 20c on which the cap nuts 1 are aligned and placed. . The rust preventive liquid tank 16 is provided with a receiving member 16a that is controlled to be moved up and down to constitute a rust preventive oil immersion portion. The receiving member 16a performs a rust preventive oil immersing step for immersing the moving tray 20c in the rust preventive oil and a pulling step for lifting the cap nut 1 from the rust preventive oil in the rust preventive liquid tank 16.

  Further, as shown in FIG. 12, there is provided a rust preventive liquid tank 16 and a moving tray moving machine 24 for performing reciprocal movement control between the rust preventive liquid tank 16 and an intermediate position X3 between the work rotating device 21. . The moving tray moving machine 24 moves to the intermediate position X3 while holding an arbitrary portion of the moving tray 20c on the receiving member 16a.

  Further, the moving tray moving machine 24 includes a cylinder operated by hydraulic pressure or air pressure, a motor, etc. in order to reverse the moving tray 20c moved to the intermediate position X3 and make the opening 5 of the cap nut 1 face downward. A reversing mechanism 25 is provided as a workpiece posture changing unit including a driving mechanism (not shown). The reversing mechanism 25 only needs to reverse the moving tray 20c so that the cap nut 1 is not dropped during the reversing. For example, as shown in FIG. 13, the cap nut 1 of the moving tray 20c is held between the upper and lower mesh members 25a, and the upper and lower mesh members 25a are reversed, or the pair of ( One is a case in which the cap nut 1 is held between two moving trays 20c and reversed.

  Returning to FIG. 12, the intermediate position X3 constitutes a part of the first oil removing section whose movement is controlled so as to enter the opening 6 (downward) of the cap nut 1 in the moving tray 20c. A plurality of suction nozzles 26 as suction portions are provided. The suction nozzle 26 is connected to a suction source (a suction pump or a suction generator using compressed air) having a suction function (not shown). The suction nozzle 26 sucks and removes the air in the bag-like space 5 of the cap nut 1 together with the excess rust preventive oil adhering to the inner surface thereof, so that the oil removing step by the suction step is performed. It is also possible to use the suction nozzle 26 in common so as to inject compressed air. In this case, a compressed air supply source (not shown) is connected via a switching valve (not shown). In addition to the suction nozzle 26, it is also possible to use another injection nozzle 26a similar to the lower nozzle 18a1 that injects compressed air. Also in this case, the injection nozzle 26a is configured as an injection unit whose movement is controlled so as to enter the bag-like space 5 of the bag nut 1, and the compressed air is injected into the bag-like space 5 to prevent it from adhering thereto. An oil removing process is performed by an injection process in which the rust oil is scattered to reduce the amount of extra rust preventive oil adhering to the inner surface of the bag-like space 5 of the cap nut 1. The combination of this suction process and the injection process constitutes a first oil removal section that can perform the first oil removal process. By this first oil removing portion, the rust preventive oil adhering to the female thread portion 4 of the cap nut 1 is reduced, so that an increase in tightening torque when the cap nut 1 is used and other locations during subsequent handling. It is possible to reduce oil adhesion to the water. Further, the suction amount sucked by the suction nozzle 26 and the spray amount ejected by the spray nozzle 26a are variably controlled.

  Further, as shown in FIG. 14, a workpiece transfer machine 27 that is controlled to reciprocate between the intermediate position X <b> 3 and a workpiece rotating device 21 as a workpiece rotating unit is provided. The workpiece transfer machine 27 can employ the same one as the above-described chuck device 22. By this work transfer machine 27, the plurality of cap nuts 1 in the inverted moving tray 20c are transferred to the work rotating device 21 which is a part of the second oil removing unit.

  The work rotating device 21 as the second oil removing unit (work rotating unit) is used in the second oil removing step (work rotating step). As shown in FIG. 15, the work rotating device 21 is provided with a plurality of rotating shafts 21a corresponding to the plurality of cap nuts 1. The rotating shaft 21a includes a driven pulley 21b fixed to the lower end side, a motor and the like. The rotation is controlled in a predetermined direction by a belt 21e spanned between the drive pulley 21d of the rotation drive source 21c. The rotating shaft 21a is provided with a pair of left and right spring members 21f inserted into the opening 6 of the cap nut 1. The rotating shaft 21a and the rotating shaft 21a are arranged so as to rotate the cap nut 1 about its central axis by elastic force. I try to rotate together.

  In addition, an external thread portion (not shown) that engages with the female thread portion 4 of the cap nut 1 can be provided on the rotary shaft 21a so that it can rotate together. Further, by configuring the rotary shaft 21a with a cylindrical hollow member, the rotary shaft 21a can be provided with a suction function such as the above-described suction nozzle 26 or an injection function such as the spray nozzle 26a. .

  Next, a surface treatment method for the bag-like workpiece will be described. A plurality of cap nuts 1 are set on the transfer tray 7a in the workpiece supply section 7 of the surface treatment line L shown in FIG. 2 with the opening 6 facing upward. The transfer tray 7a is transferred to the standby position X1 in the circulation conveyance path 9. Thereafter, the plurality of workpiece holders 10 that have reached the upper position of the standby position X1 are lowered by an elevating mechanism (not shown), and the workpiece holders 10 simultaneously hold a plurality of cap nuts 1 with the opening 6 facing upward. .

  The cap nut 1 held in this way is plated while being sequentially conveyed to a degreasing tank 12, a cathodic acid electrolytic tank 13, an anodic electrolytic degreasing tank 14, and various plating tanks 15 as various processing liquid tanks disposed in the circulation conveyance path 9. Processing is performed. In addition, the water washing tank 27 is arrange | positioned between the various process liquid tanks, and the water washing process between each process is performed.

  And the cap nut 1 after forming a predetermined plating film is conveyed in the washing | cleaning part 17 to the some washing tank 17a arrange | positioned sequentially from the conveyance direction upstream of the circulation conveyance path 9. FIG. A workpiece cleaning process is performed in which the surface of the cap nut 1 is cleaned in multiple stages with room temperature water or hot water in the plurality of cleaning tanks 17a of the workpiece cleaning unit 17. The cap nut 1 that has undergone the workpiece cleaning process is conveyed to the workpiece drying unit 18. A workpiece drying process is performed in which the moisture of the cap nut 1 is removed by the workpiece drying unit 18.

  As shown in FIG. 7, the workpiece drying process of the workpiece drying unit 18 is performed by first moving the cap nut 1 held by the workpiece holder 10 by the operation of the posture changing mechanism 11 and the opening 6 of the cap nut 1. Converted to a downward posture. Thereafter, the compressed air is sprayed from the plurality of lower nozzles 18a1 of the water droplet removing device 18a to the bag nut 1 held by the work holder 10, and the water droplets in the bag-like space 5 are blown off and removed. A water droplet removing step is performed in which the water droplets on the surface of the cap nut 1 are blown off by the compressed air sprayed from the upper nozzle 18a2. In this way, by substantially removing the water droplets adhering to the cap nut 1 by the compressed air, it is possible to reduce the burden on the drying device 18b (drying furnace 18b1) used in the subsequent drying step (to save energy). It becomes.

  Then, the cap nut 1 from which the water droplets on the surface have been removed in this manner is converted into a posture with the opening 6 facing upward by the operation of the posture changing mechanism 11 while being held by the work holder 10. Thereafter, a drying process is performed in which moisture such as the surface of the cap nut 1 and pinholes of the plating film is removed by being transferred to the drying furnace 18b1 of the drying device 18b shown in FIG. 8 and passing through the drying furnace 18b1. .

  Then, the cap nut 1 which passed the workpiece | work drying process progresses to the antirust oil application process performed in the antirust oil application part 19 which is the next process. In this rust preventive oil application step, the cap nut 1 removed from the workpiece holder 10 and placed on the temporary placement tray 8a at the workpiece removal position X2 of the circulation conveyance path 9 is, as shown in FIG. 22 is held by a chuck claw 22b facing downward, and is placed on a moving tray 20c waiting on the proximal end side 20a of the transfer conveyance path 20. The transfer tray 20c is moved to the end side 20b of the transfer conveyance path 20 (see FIG. 9). Thereafter, as shown in FIG. 11, the transfer tray 20 c is held by the moving tray transporter 23 and is moved to the receiving member 16 a of the rust prevention liquid tank 16 as a rust prevention portion. The receiving member 16a performs a rust preventive oil immersing step for immersing the movable tray 20c in the rust preventive oil and a pulling step for pulling the movable tray 20c from the rust preventive oil.

  Further, as shown in FIG. 12, the moving tray moving machine 24 moves the moving tray 20c on the receiving member 16a to the intermediate position X3 while holding it. At this position, as shown in FIG. 13, the moving tray 20c is turned upside down by the reversing mechanism 25 (work posture changing portion), and the opening 5 of the cap nut 1 faces downward, so that the opening of the cap nut 1 is opened. The rust preventive oil is caused to flow down from its own weight from 6 to remove excess rust preventive oil inside the cap nut 1. Thereafter, the suction nozzle 26 as the suction portion shown in FIG. 12 is moved so as to be disposed in the bag-like space 5 of the bag nut 1, and suction for removing excess rust preventive oil adhering to the inner surface of the bag-like space 5 is performed. The process (see FIG. 16 (a)) and / or the injection nozzle 26a is moved so as to be disposed in the bag-like space 5 of the bag nut 1, and excess rust preventive oil adhering to the inner surface of the bag-like space 5 is removed. The injection process (refer FIG.16 (b), (c)) to perform is performed. Moreover, the suction process (refer FIG.16 (d)) by the suction nozzle 26 can also be performed simultaneously with or after the injection process by the injection nozzle 26a. In this case, since the oil mist M of the rust-preventing oil generated at the time of injection can also be removed by suction (oil mist suction process) by the suction nozzle 26, the oil mist M can be prevented from scattering, so that the surrounding environment can be maintained. it can. Further, the same oil removing process can be performed by the suction nozzle 26 having both the suction function and the injection function. In other words, it is arranged in the bag-like space 5 of the cap nut 1 whose posture has been changed, and the air in the bag-like space 5 is sucked together with the rust preventive oil adhering thereto, or the bag-like space 5 Compressed air is injected into the rust preventive oil adhering thereto, or after the injection, the air in the bag-like space 5 is sucked together with the rust preventive oil remaining in the space. The oil removal process is performed. As a result, the rust preventive oil adhering to the female threaded portion 4 of the cap nut 1 is reduced, thereby increasing the tightening torque when the cap nut 1 is used and attaching oil to other locations during subsequent handling. It can be reduced.

  Subsequently, as shown in FIG. 14, the cap nut 1 of the moving tray 20 c is held by the chuck claw 22 b that faces the horizontal direction in the chuck device 22 of the workpiece transfer machine 27, and the second oil removing unit (work rotating unit). As a workpiece rotating device 21. As shown in FIG. 15, the cap nut 1 transferred to the workpiece rotating device 21 is held so as to rotate together with the rotary shaft 21a, and adheres to the outer surface of the cap nut 1 by the rotation of the rotary shaft 21a. The work rotation process is performed as a second oil removal process in which the rust preventive oil being removed is scattered in the form of oil droplets. The removal of the rust preventive oil by the centrifugal force is such that the rotational speed of the rotary shaft 21a is controlled so that the rust preventive oil remains in the form of a film on the surface of the cap nut 1. As a result, the rust preventive oil adhering to the female threaded portion 4 of the cap nut 1 is reduced, thereby increasing the tightening torque when the cap nut 1 is used and attaching oil to other locations during subsequent handling. It can be reduced. Further, if the rotary shaft 21a has a suction function, the suction step can be performed during the rotation operation.

  In this rust preventive oil application process, since the moisture of the cap nut 1 is removed by hot air in the drying process of the previous process, the unapplied part due to repelling of the rust preventive oil can be eliminated. Moreover, the surface treatment line L which can advance to a rust prevention oil application | coating process continuously from such a dry state can be constructed | assembled. This makes it possible to remove moisture that has entered fine pinholes in the plating film, for example, and it is easy for rust preventive oil to enter the pinholes from which the moisture has been removed, thereby improving the rust prevention effect. It becomes.

The surface of a cap nut which is a bag-like work, and a sectional view. The conceptual diagram of the surface treatment line of the bag-shaped workpiece | work of this invention. Schematic of each state of a workpiece holder. Schematic of the attitude | position conversion state of a workpiece | work holder. The conceptual diagram of an attitude | position conversion apparatus. The partial schematic of the line base end side in a surface treatment line. Schematic of the water droplet removal apparatus of a workpiece | work drying part. Schematic of the drying apparatus of a workpiece | work drying part. The partial schematic diagram of the line termination side in a surface treatment line. Schematic of the workpiece | work movement between a line terminal side and a transfer conveyance path. Schematic of workpiece transfer from a transfer conveyance path to a rustproof oil tank. Schematic between a rust prevention oil tank and a workpiece | work rotation apparatus. The schematic diagram of the work reversal state by a reversing mechanism. Schematic which transfers the reversed workpiece | work to a workpiece | work rotation apparatus. Schematic of a work rotation device. The schematic diagram which shows the state of each process of a 1st oil removal process.

Explanation of symbols

1 Cap nut (bag-shaped workpiece)
DESCRIPTION OF SYMBOLS 5 Bag-shaped space 6 Opening part 17 Work washing | cleaning part 18 Work drying part 18a Water droplet removal apparatus 18b1 Drying furnace 19 Antirust oil application part 26 Suction nozzle 26a Injection nozzle

Claims (9)

After forming a predetermined plating film on a bag-shaped workpiece having a bag-shaped space, in a surface treatment line in which rust preventive oil is applied to the plating film,
In a posture with the opening of the bag-shaped space facing upward, a rust-preventing oil immersion portion for immersing the bag-shaped workpiece in the rust-preventing oil,
When pulling up from the rust preventive oil of the bag-like workpiece, a workpiece posture changing unit that converts the rust preventive oil to flow down by its own weight by converting the opening of the bag-like space downward.
Arranged in the bag-shaped space of the bag-shaped workpiece whose posture has been changed, the air in the bag-shaped space is sucked together with the rust preventive oil adhering thereto, or the compressed air is injected into the bag-shaped space A first oil removing section that scatters the rust preventive oil adhering thereto, or sucks the air in the bag-like space together with the rust preventive oil remaining in the space after the jetting,
A second oil removing unit that rotates the bag-shaped workpiece around its central axis and scatters the antirust oil adhering to the outer surface of the bag-shaped workpiece by centrifugal force;
A surface treatment line for bag-like workpieces, comprising:   2. The bag-shaped workpiece surface treatment line according to claim 1, wherein the suction amount sucked by the first oil removing unit and the spray amount to be sprayed are variably controlled.   The said 2nd oil removal part was made to control the rotation speed of a shaft rotation so that the antirust oil of the outer surface of a bag-shaped workpiece | work might be formed in a film | membrane form, It is characterized by the above-mentioned. The surface treatment line for the bag-shaped workpiece described.   The surface treatment line for a bag-shaped workpiece according to any one of claims 1 to 3, wherein suction or / and jetting are performed by the first oil removing unit during a shaft rotation operation of the bag-shaped workpiece. . In a surface treatment method in which a predetermined plating film is formed on a bag-shaped workpiece having a bag-shaped space, and then a rust preventive oil is applied to the plating film,
In a posture with the opening of the bag-shaped space facing upward, a rust-preventing oil immersing step of immersing the bag-shaped workpiece in the rust-preventing oil,
When pulling up from the rust preventive oil of the bag-like workpiece, the workpiece posture conversion step of converting the rust preventive oil to flow down by its own weight by converting the opening of the bag-like space downward.
Arranged in the bag-shaped space of the bag-shaped workpiece whose posture has been changed, the air in the bag-shaped space is sucked together with the rust preventive oil adhering thereto, or the compressed air is injected into the bag-shaped space A first oil removing step of scattering the rust preventive oil adhering thereto, or sucking the air in the bag-shaped space together with the rust preventive oil remaining in the space after the jetting,
A second oil removing step in which the bag-like workpiece is rotated about its central axis, and the antirust oil adhering to the outer surface of the bag-like workpiece is scattered by centrifugal force;
A surface treatment method for a bag-like workpiece, comprising:   The bag-shaped workpiece surface treatment method according to claim 5, wherein suction is performed after the jetting in the first oil removing step.   The bag-shaped workpiece surface treatment method according to claim 5 or 6, wherein the suction amount and the injection amount to be sucked in the first oil removing step are variably controlled.   8. The second oil removing step according to claim 5, wherein the rotational speed of the shaft rotation is controlled so that the antirust oil on the surface of the bag-like workpiece is formed in a film shape. The surface treatment method for a bag-like workpiece according to item 1.   The surface treatment method for a bag-shaped workpiece according to any one of claims 5 to 8, wherein suction or / and jetting in the first oil removing step is performed during the shaft rotation operation of the bag-shaped workpiece. .

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