JP7770201B2 - Fluidized dip coating device and method for manufacturing wiring member having insulating coating - Google Patents

Description

This disclosure relates to a fluidized bed dip coating device and a method for manufacturing wiring components with insulating coatings using the device.

Conventionally, insulated busbars, which have a plate-shaped conductor made of a conductive material and an insulating layer disposed on the conductor, have been used as wiring components for transmitting current within power conversion devices such as inverters and converters. One known method for manufacturing insulated busbars involves fluidized dip coating, in which a fluidized bath is provided in a tank containing a powder coating material such as a thermosetting resin, in which compressed air is injected through a porous partition at the bottom to fluidize the powder coating. The insulating layer is then formed by immersing the conductor in the fluidized bath (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2021-48001

Patent Document 1 describes a method for manufacturing an insulated busbar in which a preheated conductor is immersed in powder paint flowing in a tank to apply the powder paint to the outer periphery of the conductor, and then heat treatment is performed to harden the applied powder paint, thereby forming an insulating layer around the outer periphery of the conductor. It also describes how the amount of powder paint attached to the conductor can be made uniform by changing the immersion direction of the conductor in the tank each time it is immersed.

However, when the conductor is pulled out of the powder paint tank, more powder paint than necessary accumulates on the top surface of the conductor and in the mounting holes in the conductor. If heat treatment to harden the conductor is performed in this state, there are issues such as the molten paint dripping and the hardened paint blocking the mounting holes.

This disclosure has been made in response to the above-mentioned problems. It aims to provide a fluidized bed dip coating device that can prevent excessive accumulation of powder paint on the top edge of a workpiece or inside a mounting hole when applying powder paint to workpieces of various shapes using fluidized bed dip coating.

The fluidized bed coating apparatus of the present disclosure is characterized by comprising a support housing equipped with a transport jig holding section, a fluidized bed for fluidizing powder paint, a transport jig held by the transport jig holding section and suspending the object to be coated above the fluidized bed, a lifting drive section provided in the support housing and lowering the transport jig until the object to be coated is immersed in the fluidized bed and lifting the object to be coated out of the fluidized bed, and a first drive section which is a shake-off drive section provided in the lifting portion of the lifting drive section and which is raised and lowered together with the transport jig and the object to be coated by the lifting drive section and which vibrates the transport jig in an up and down direction.

The method for manufacturing an insulating coated conductor according to the present disclosure comprises: (a) heating the conductor at a first temperature; (b) after step (a), using a lifting drive unit to lower the conductor from above a fluidization tank in which the powder paint is flowing, immersing it in the powder paint, and adhering the powder paint to the conductor; and (c) after step (b), using the lifting drive unit to lift the conductor from the powder paint and apply acceleration to the conductor alternately in an upward and downward direction , wherein the acceleration applied to the conductor in step (c) is characterized in that the application of acceleration to the conductor is performed by a shaking-off drive unit that is provided in a lifting portion of the lifting drive unit and that raises and lowers the object to be coated and the transport jig that suspends the object to be coated by the lifting drive unit, and that vibrates the transport jig in an up and down direction .

The fluidized bed dip coating device disclosed herein is capable of immersing an object to be coated in a fluidized bed of powder paint, then lifting it up, and then applying alternating upward and downward acceleration to the object to lift it up from the fluidized bed and lower it back down into the fluidized bed. This shakes off any excess powder paint that has accumulated, preventing molten paint from dripping during heat treatment for curing and preventing the hardened paint from clogging the mounting holes.

1 is a front view showing the appearance of a fluidized bed dip coating apparatus 100 according to the first or second embodiment. FIG. 1 is a side view showing the appearance of a fluidized bed dip coating apparatus 100 according to the first or second embodiment. FIG. 1 is a perspective view showing the appearance of a wiring member 32A having an insulating coating manufactured using a fluidized bed dip coating apparatus 100 in accordance with the first or second embodiment. FIG. 10 is a flowchart S100 showing a method for manufacturing a wiring member having an insulating coating according to the first embodiment. 10 is a perspective view showing a manufacturing process of step S101 or S201 of the manufacturing method of a wiring member having an insulating coating in the first or second embodiment. FIG. FIG. 10 is a perspective view showing the manufacturing process of step S102 or S202 of the manufacturing method for a wiring member having an insulating coating according to the first or second embodiment. 10 is a front view showing the manufacturing process of step S103 or S203 of the manufacturing method for a wiring member having an insulating coating in the first or second embodiment. FIG. 10 is a front view showing the manufacturing process of step S105 or S205 of the manufacturing method for a wiring member having an insulating coating in the first or second embodiment. FIG. FIG. 10 is a front view showing the manufacturing process of step S106 of the method for manufacturing a wiring member having an insulating coating in the first embodiment. 10 is a front view showing the manufacturing process of step S107 or S207 of the manufacturing method for a wiring member having an insulating coating in the first or second embodiment. FIG. 7 is a cross-sectional view of the conductor 30A shown in FIG. 6 taken along the line XX immediately before being placed in a heat treatment furnace in step S109 in the case where step S107 of the method for manufacturing a wiring member having an insulating coating in embodiment 1 is not performed. 7 is a cross-sectional view of the XX portion of the conductor 30A shown in FIG. 6 immediately before being placed in a heat treatment furnace in step S109 in the method for manufacturing a wiring member having an insulating coating according to the first embodiment. 10 is a flowchart S200 showing a method for manufacturing a wiring member having an insulating coating according to the second embodiment. FIG. 11 is a front view showing the manufacturing process of step S206 of the method for manufacturing a wiring member having an insulating coating in the second embodiment. 7 is a cross-sectional view of the XX portion of the conductor 30A shown in FIG. 6 immediately before being placed in a heat treatment furnace in step S209 in the method for manufacturing a wiring member having an insulating coating according to the second embodiment.

Embodiment 1.
FIG. 1 is a front view showing the exterior of a fluidized dip coating apparatus 100 according to a first embodiment. FIG. 2 is a side view showing the exterior of the fluidized dip coating apparatus 100 according to the first embodiment. The fluidized dip coating apparatus 100 is composed of a fluidization tank 10 and a conveying unit 20. The fluidization tank 10 has a perforated plate 12 with a plurality of holes 11 formed in the lower portion of the fluidization tank 10. The fluidization tank 10 can fluidize the powder coating material 13 contained in the fluidization tank 10 by introducing compressed gas 14 from the underside of the perforated plate 12 toward the powder coating material 13 contained in the fluidization tank 10. Here, the gas 14 is, for example, air or an inert gas.

The transport unit 20 also has a support housing 21, a support column 22, an elevation drive unit 23, a shake-off drive unit 24, and a transport jig holder 25. The transport jig holder 25 is provided on the support housing 21 and holds the transport jig 27, which is suspended from the workpiece 30 using a suspender 26, to prevent it from falling. The transport jig holder 25 can also detachably hold the transport jig 27.

As shown in Figures 1 and 2, the conveying unit 20 is installed so that the conveying jig 27 held by the conveying jig holding unit 25 can be positioned above the flow bath 10. In Figures 1 and 2, as an example, a single linear-shaped object to be coated 30 is hung from the conveying jig 27, but this is not limited to this, and multiple objects to be coated of the same shape or multiple objects to be coated of different shapes may also be used.

The lifting drive unit 23 is provided on the support housing 21. The lifting drive unit 23 can lower a transport jig 27 arranged above the fluidization tank 10 toward the fluidization tank 10, and then lift the lowered transport jig 27 above the fluidization tank 10. The lifting drive unit 23 is, for example, a lifting actuator.

The shake-off drive unit 24 is provided on the support housing 21. In order to shake off excess powder paint 13 accumulated on the object to be coated 30, the shake-off drive unit 24 can vibrate the conveying jig 27 up and down at short intervals while the lifting drive unit 23 lowers the conveying jig 27 to a height where the object to be coated 30 does not come into contact with the powder paint 13 in the fluidization tank 10. In addition, by vibrating the conveying jig 27 up and down, the object to be coated 30 can be vibrated up and down via the hanging device 26.

In other words, by driving the shake-off drive unit 24, the transport jig 27 is vibrated in the vertical direction, and acceleration in the vertical direction can be applied to the workpiece 30 via the hanging device 26, alternately in the upward and downward directions. The shake-off drive unit 24 is, for example, a shake-off actuator. Here, the shake-off drive unit 24 is not necessarily required, and the lift drive unit 23 may vibrate the transport jig 27 in the vertical direction at short intervals in addition to lowering and raising the transport jig 27 toward the fluidization tank 10. Here, the vertical direction refers to the direction in which the transport jig 27 is raised upward from the fluidization tank 10 and lowered into the fluidization tank 10.

The powder coating material 13 used in fluidized bed dip coating using the fluidized bed dip coating device 100 can be either a thermosetting or thermoplastic coating material. When the powder coating material 13 is a thermosetting coating material, for example, a coating material using epoxy, polyester, epoxy polyester, acrylic, or the like as the base resin is used. When the powder coating material 13 is a thermoplastic coating material, for example, a coating material using vinyl chloride, polyethylene, nylon, saturated polyester, or the like as the base resin is used.

Figure 3 shows, as an example of the object 30 to be coated in embodiment 1, a wiring member 32A on which an insulating coating 31A is applied by fluidized dip coating using a fluidized dip coating apparatus 100 to a conductor 30A. That is, the wiring member 32A has an insulating coating 31A formed on the surface of the conductor 30A by fluidized dip coating using the fluidized dip coating apparatus 100. The thickness of the insulating coating 31A needs to be changed depending on the voltage applied to the wiring member 32A; for example, an insulating coating 31A with a thickness of 0.1 mm to 3 mm is applied.

Wiring member 32A is used, for example, as a wiring member for conducting large amounts of current in a distribution board or control panel. However, the use of wiring member 32A is not limited to this. Furthermore, terminal portion 33A, which is the portion of wiring member 32A that connects to another terminal, is provided with terminal portion mounting hole 34A. Furthermore, insulating coating portion mounting hole 35A is provided in the insulating coating portion provided with insulating coating 31A. For example, bolts can be passed through terminal portion mounting hole 34A, insulating coating portion mounting hole 35A, or both terminal portion mounting hole 34A and insulating coating portion mounting hole 35A to secure the wiring member to a distribution board or control panel.

In embodiment 1, a straight-line wiring member 32A is shown as an example of a wiring member, but since wiring member 32A is formed to fit the size and wiring path of the switchboard or control panel, it may have various shapes, such as multiple bends. Furthermore, materials used for conductor 30A include, for example, copper, aluminum, or alloys or clad materials primarily composed of copper or aluminum.

Figure 4 shows a flowchart S100 illustrating a method for manufacturing a wiring member having an insulating coating in embodiment 1. Figures 5 to 10 show the manufacturing process for wiring member 32A in the main steps of flowchart S100. Here, a method for manufacturing wiring member 32A when using a thermosetting paint or a thermoplastic paint as powder coating 13 is described. Note that the main difference between the manufacturing methods using a thermosetting paint and a thermoplastic paint is the heat treatment step; when a thermoplastic paint is used, the heat treatment step S109 for hardening is not required.

First, in step S101, a surface preparation is performed, such as removing oil and dirt adhering to the surface of the conductor 30A shown in Figure 5. Next, in step S102, as shown in Figure 6, a masking member 36 is provided on the conductor 30A after the surface preparation to prevent the powder coating material 13 from adhering to the terminal portions 33A provided at both ends of the conductor 30A. Here, the masking member 36 is, for example, a heat-resistant film or sheet.

In step S103, as shown in FIG. 7, the conductor 30A provided with the masking member 36 is suspended from a transport jig 27 using a suspender 26. The transport jig 27 is a heat-resistant member with sufficient rigidity to suspend a coating object 30 such as the conductor 30A. The transport jig 27 also has a connecting portion that connects the suspender 26. The conductor 30A is suspended from the transport jig 27 by the suspender 26, and can swing around the connecting portion of the transport jig 27 as a base point. The connecting portion is not shown in FIG. 7.

Next, in step S104, the conductor 30A suspended from the transport jig 27 is preheated by placing the conductor 30A in a heat treatment furnace and heating it. Here, the conductor 30A is placed in the heat treatment furnace together with the transport jig 27 while suspended from the suspender 26, for example. A diagram showing the heat treatment process in step S104 is omitted.

The time for preheating the conductor 30A is, for example, the time until the conductor 30A reaches the same temperature as the temperature inside the heat treatment furnace. Furthermore, if the powder coating 13 is a thermosetting coating, the temperature inside the heat treatment furnace for preheating is approximately 100°C to 200°C, which is higher than the melting point of the powder coating 13. Furthermore, if the powder coating 13 is a thermoplastic coating, the temperature inside the heat treatment furnace for preheating is approximately 200°C to 300°C. The temperature inside the heat treatment furnace to which the conductor 30A is heated for preheating is the first temperature described in the claims.

Next, the conductor 30A, which has been heated to a temperature equivalent to that inside the heat treatment furnace, is removed from the heat treatment furnace, and the transport jig 27 is held by the transport jig holder 25 provided in the transport section 20 of the fluidized bed coating apparatus 100. Then, in step S105, as shown in FIG. 8, the conductor 30A suspended from the transport jig 27 is transported above the fluidized bed tank 10. In other words, the conductor 30A suspended from the transport jig 27 is positioned above the fluidized bed tank 10.

Next, in step S106, as shown in FIG. 9, the lifting drive unit 23 provided on the support housing 21 of the transport unit 20 of the fluidized bed dip coating apparatus 100 is driven to lower the conductor 30A to a height where it is fully immersed in the powder paint 13 flowing in the fluidized bed tank 10. The conductor 30A is then immersed in the powder paint 13 for a preset time, thereby adhering the powder paint 13 to the conductor 30A. Here, by setting the immersion time, which is the time the conductor 30A is immersed and remains in the powder paint 13, to 10 seconds or less, it is possible to shake off excess powder paint 13 in the next process, step 107.

After the conductor 30A has been immersed in the powder paint 13, in step S107, the lifting drive unit 23 is driven to lift the conductor 30A, as shown in FIG. 10. The height to which the conductor 30A is lifted is set so that the conductor 30A does not come into contact with the powder paint 13 within the fluidization tank 10. By keeping the conductor 30A within the fluidization tank 10 in this way, it is possible to prevent the powder paint 13 shaken off the conductor 30A from leaking out of the fluidization tank 10.

Furthermore, in step S107, the shake-off drive unit 24 provided on the support housing 21 of the transport unit 20 of the fluidized bed dip coating apparatus 100 is driven to move the transport jig 27, from which the conductor 30A is suspended, alternately upward and downward multiple times in a short cycle. That is, by vibrating the transport jig 27 vertically, the conductor 30A is vibrated vertically via the suspending device 26. In other words, by driving the shake-off drive unit 24, the transport jig 27 is vibrated vertically, and acceleration is applied alternately upward and downward to the conductor 30A via the suspending device 26. Here, the upward direction refers to the direction in which the transport jig 27 is pulled upward from the fluidized bed 10, and the downward direction refers to the direction in which the transport jig 27 is lowered into the fluidized bed 10.

Here, by applying an acceleration of, for example, 8 to 12 G to the conductor 30A in the upward and downward directions, the excess powder paint 13 that has accumulated on the conductor 30A can be lifted up and shaken off. The number of times that the conductor 30A is vibrated in the up and down directions is, for example, 8 to 12 times. Here, each movement in the upward and downward directions is counted as one vibration.

Furthermore, the more times the conductor 30A is vibrated up and down, the more excess powder paint 13 can be shaken off. However, if the number of vibrations is too many, the temperature of the conductor 30A will drop, and when the conductor 30A is again immersed in the powder paint 13 in the fluidization tank 10, the powder paint 13 will not adhere to the conductor 30A. Therefore, it is best to set the number of vibrations up and down taking into account the temperature drop of the conductor 30A.

The suspender 26 may be, for example, a heat-resistant rod-shaped member such as a metal rod or wire with a diameter of 1 mm to 9 mm, a strip-shaped member such as a metal ribbon, or a combination of a rod-shaped member and a strip-shaped member. By using such a member for the suspender 26, the suspender 26 can be deflected by vibrating the transport jig 27 in the vertical direction, thereby increasing the acceleration applied to the conductor 30A. This improves the effectiveness of shaking off excess powder paint 13 that has accumulated on the conductor 30A.

So far, we have explained that in step S107, by vibrating the conductor 30A in the vertical direction, alternating acceleration in the upward and downward directions is applied to the conductor 30A, thereby shaking off excess powder paint 13. However, this is not limited to this. For example, even if the conductor 30A is vibrated in an oblique vertical direction, which is a direction at an angle to the vertical direction, vertical acceleration can be applied by a component force, making it possible to shake off excess powder paint 13.

Furthermore, in step S107, the shake-off drive unit 24 in the transport unit 20 of the fluidized bed dip coating apparatus 100 is driven to apply acceleration to the conductor 30A in the vertical direction. However, this is not limited to this. For example, acceleration may be applied alternately in the upward and downward directions to the conductor 30A by vibrating the transport jig 27 in the vertical direction using the lift drive unit 23 that raises and lowers the transport jig 27.

Next, in step S108, it is confirmed whether the preset number of dippings has been reached. The preset number of dippings is set in advance as the number of dippings required to achieve the required thickness of the coating film 40 formed by applying the powder coating material 13 to the surface of the conductor 30A. The number of dippings is set using previously obtained data indicating the relationship between the number of dippings and the thickness of the coating film 40. The number of dippings is counted each time step S106 is processed. The thickness of the coating film 40 can be measured, for example, by cutting the conductor 30A after dipping and observing the cross section.

If the number of immersions has not reached the preset number of immersions in step S108, the process returns to step S106 along the No arrow in flowchart S100, and the conductor 30A is again immersed in the powder paint 13 in the fluidization tank 10. On the other hand, if the number of immersions has reached the preset number of immersions, the process of adhering the powder paint 13 to the conductor 30A ends, and the process proceeds to the next process, step S109, along the Yes arrow in flowchart S100.

In step S109, the conductor 30A is placed in a heat treatment furnace and heated to melt and harden the coating film 40 by heat treatment. A diagram showing the heat treatment process in step S109 is omitted here.

In step S109, the conductor 30A, which has a coating film 40 formed by adhering powder coating material 13 and is suspended from the transport jig 27, is heated in a heat treatment furnace to harden the coating film 40 and form an insulating coating 31A. Here, the conductor 30A is left in the heat treatment furnace until the coating film 40 hardens, and is then removed from the heat treatment furnace after the hardening time has elapsed.

When using a thermosetting paint, the temperature inside the heat treatment furnace for hardening the coating film 40 is preferably 160°C to 190°C. Here, the temperature inside the heat treatment furnace for hardening the coating film 40 is the second temperature described in the claims. Furthermore, when using a thermoplastic paint, the coating film 40 cools and hardens as the temperature drops, forming a coating that functions as the insulating coating 31A, so no heat treatment is required for hardening.

After confirming that the coating film 40 formed on the conductor 30A has hardened, in step S110, the masking members 36 provided on the terminal portions 33A provided on both ends of the conductor 30A are removed. This allows the production of a wiring member 32A, as shown in Figure 3, which has an insulating coating 31A in areas other than the terminal portions 33A.

Next, the effects of the manufacturing method for wiring members having an insulating coating in embodiment 1 will be described using Figures 11 and 12. Figure 11 shows a cross-sectional view of the X-X portion of conductor 30A in Figure 6 immediately before being placed in a heat treatment furnace in step S109, when step S107 in flowchart S100 is not performed.

As shown in Figure 11, powder paint 13 softened or melted by the preheated conductor 30A adheres to the surface of the conductor 30A, forming a coating film 40A. Furthermore, more powder paint 13 than necessary for the coating film 40A adheres in powder form inside the insulating coating mounting hole 35A and on the top surface 37A of the conductor. If the process proceeds to step S109 in this state and the product is placed in a heat treatment furnace to harden the coating film 40A, problems may arise, such as the paint drooping due to the excess powder paint 13 melting and becoming fluid, or the hardened paint clogging the insulating coating mounting hole 35A.

On the other hand, Figure 12 shows a cross-sectional view of the X-X portion of the conductor 30A in Figure 6 immediately before being placed in the heat treatment furnace in step S109 after processing step S107 in flowchart S100. As shown in Figure 12, the coating film 40B formed on the surface of the conductor 30A is able to shake off excess powder paint 13 adhering to the inside of the insulating coating mounting hole 35A and the top surface 37A of the conductor 30A by applying acceleration alternately upward and downward in step S107. This prevents problems such as sagging of the powder paint due to excess powder paint 13 melting and becoming fluid, or the hardened paint clogging the insulating coating mounting hole 35A.

As shown in Figures 1 and 2, the fluidized bed dip coating apparatus 100 in embodiment 1 is composed of a fluidized bed tank 10 and a conveying unit 20. The conveying unit 20 also has a support housing 21, a support column 22, an elevation drive unit 23, a shake-off drive unit 24, and a conveying jig holder 25. The shake-off drive unit 24 can vibrate the conveying jig 27 up and down at short intervals in order to shake off excess powder paint 13 accumulated on the workpiece 30.

In other words, the fluidized dip coating apparatus 100 has the feature of being able to apply alternating upward and downward acceleration to the workpiece 30 via the hanging device 26 by vibrating the transport jig 27 in the vertical direction. Furthermore, the shake-off drive unit 24 is not necessarily required, and the lift drive unit 23 may have the function of vibrating the transport jig 27 in the vertical direction at short intervals in addition to lowering and lifting the transport jig holder 25 toward the fluidized bath 10. This allows for the powder paint 13 that has accumulated in excess of the workpiece 30 to be shaken off after the workpiece 30 is lifted from the powder paint 13 in the fluidized bath 10 during fluidized dip coating.

Furthermore, the method for manufacturing an insulating coated wiring member in embodiment 1 using the fluidized bed dip coating apparatus 100 includes step S107, in which, after lifting the conductor 30A from the powder coating material 13 in the fluidized bed tank 10, the conductor 30A is vibrated in an up-and-down direction to shake off any excess powder coating material 13 that has accumulated. This prevents the molten coating material from dripping during the heat treatment for hardening in step S109, and prevents the hardened coating material from clogging the insulating coating mounting hole 35A.

In other words, after the conductor 30A is lifted from the powder paint 13 in the fluidization tank 10, the transport jig 27 is vibrated in the vertical direction, and alternating upward and downward acceleration is applied to the conductor 30A via the hanging device 26. This shakes off any excess powder paint 13 that has accumulated, preventing molten paint from dripping during the heat treatment for hardening and preventing the hardened paint from clogging the insulating coating mounting hole 35A.

Embodiment 2.
Next, a method for manufacturing a wiring member having an insulating coating according to the second embodiment will be described with reference to a flow chart S200 shown in Fig. 13. In the second embodiment, only the differences in the configuration from the first embodiment will be described.

The method for manufacturing a wiring member having an insulating coating in embodiment 2 differs from embodiment 1 only in that step S206 of flowchart S200 is used instead of step S106 of flowchart S100 in embodiment 1. Also, in embodiment 2, the fluidized bed dip coating apparatus 100 is used, just like in embodiment 1.

Furthermore, in the first embodiment, it was explained that the fluidized bed dip coating apparatus 100 can vibrate the transport jig 27 vertically at short intervals when the transport jig 27 is lowered to a height where the powder coating material 13 does not touch the workpiece 30. In the second embodiment, the fluidized bed dip coating apparatus 100 has the additional feature of being able to vibrate the transport jig 27 vertically at short intervals even when the workpiece 30 is immersed in the fluidized bed 10.

Figure 13 shows a flowchart S200 illustrating a method for manufacturing a wiring member having an insulating coating in embodiment 2. Note that steps S201 to S205 and S207 to S210 in flowchart S200 are similar to steps S101 to S105 and S107 to S110 in flowchart S100 in embodiment 1, and therefore detailed description thereof will be omitted.

Figure 14 shows the manufacturing process for wiring member 32A in step S206 of flowchart S200. Other major manufacturing steps are shown in Figures 5 to 8 and 10. In step S206, conductor 30A, which has been preheated in step S204, is lowered to a height that allows it to be fully immersed in powder paint 13 flowing in fluidization tank 10.

Then, with the conductor 30A immersed in the fluidization tank 10, the shake-off drive unit 24 is driven to vibrate the conveying jig 27 in the vertical direction, and the conductor 30A is vibrated in the vertical direction within the powder paint 13 in the fluidization tank 10 via the hanging device 26.

In addition, in step S206, the shake-off drive unit 24 provided on the support housing 21 of the conveying unit 20 of the fluidized bed dip coating apparatus 100 is driven to vibrate the conductor 30A in the vertical direction. However, this is not limited to this, and for example, the conductor 30A may be vibrated in the vertical direction using the lifting drive unit 23 that raises and lowers the conveying jig 27. Here, the vertical direction refers to the upward direction, which is the direction in which the conveying jig 27 is pulled up from the fluidized bed 10, and the downward direction, which is the direction in which the conveying jig 27 is lowered into the fluidized bed 10.

After step S206 is completed, the wiring member 32A having the insulating coating 31A can be manufactured by following steps S207 to S210, which are similar to steps S107 to S110 in flowchart S100 of embodiment 1.

Next, the effects of the manufacturing method of a wiring member having an insulating coating in embodiment 2 will be described using Figure 15. Figure 15 shows an X-X cross-sectional view of the conductor 30A shown in Figure 6 immediately before being placed in the heat treatment furnace in step S209 of flowchart S200. As shown in Figure 15, the powder coating material 13 softened or melted by the preheated conductor 30A adheres to the surface of the conductor 30A, forming a coating film 40C. In addition, the thickness of the coating film 40C adhered to the lower surface 38A of the conductor 30A is prevented from becoming thinner than the thickness of the coating film 40C on the upper surface 37A and side surface 39A of the conductor 30A.

The powder coating material 13 adhering to the underside 38A of the conductor 30A is more susceptible to the effects of gravity and is more likely to fall than the upper surface 37A and side surfaces 39A of the conductor 30A. Therefore, in step S206, by vibrating the conductor 30A vertically within the powder coating material 13, the powder coating material 13 is actively pressed against the underside 38A of the conductor 30A, increasing the amount of powder coating material 13 adhering to the underside 38A of the conductor 30A and making the thickness of the coating film 40C on the underside 38A thicker than in embodiment 1.

In this way, as shown in Figure 14, the fluidized bed dip coating apparatus 100 in embodiment 2 can vibrate the transport jig 27 vertically at short intervals while the workpiece 30 is immersed in the fluidized bed 10. This actively presses the underside of the workpiece 30 against the powder paint 13, thereby increasing the amount of powder paint 13 that adheres to the underside of the workpiece 30.

Furthermore, by using flowchart S200, which is the method for manufacturing a wiring member having an insulating coating in embodiment 2, in addition to the effects of the method for manufacturing a wiring member having an insulating coating in embodiment 1, it is possible to increase the amount of powder coating 13 that adheres to the underside 38A of the conductor 30A, and prevent the thickness of the coating film 40C on the underside 38A from becoming thinner than the thickness of the upper surface 37A and side surface 39A of the conductor 30A. This reduces variation in the thickness of the insulating coating 31A on the wiring member 32A.

10 fluidization tank, 11 hole, 12 perforated plate, 13 powder coating material, 14 gas, 20 transport unit, 21 support housing, 22 support column, 23 lifting drive unit, 24 shake-off drive unit, 25 transport jig holder, 26 lifting tool, 27 transport jig, 30 object to be coated, 30A conductor, 31A insulating coating, 32A wiring member, 33A terminal portion, 34A terminal portion mounting hole, 35A insulating coating portion mounting hole, 36 masking member, 37A upper surface, 38A lower surface, 39A side surface, 40, 40A, 40B, 40C coating film, 100 fluidization dip coating device, S100, S200 flowchart.

Claims (8)

a support housing including a transport jig holder;
a fluidization tank for fluidizing the powder coating material;
a conveying jig that is held by the conveying jig holding section and that suspends the object to be coated above the fluidization tank;
an elevation drive unit provided in the support housing, which lowers the transport jig until the object to be coated is immersed in the fluidization tank and then lifts the object to be coated out of the fluidization tank;
A fluidized bed coating apparatus comprising: a first drive unit which is a shake-off drive unit provided in the lifting and lowering portion of the lifting and lowering drive unit, which is raised and lowered together with the conveying jig and the object to be coated by the lifting and lowering drive unit, and which vibrates the conveying jig in the vertical direction. The fluidized bed dip coating apparatus according to claim 1 , wherein the object to be coated is suspended from the transport jig via a suspension tool. the shake-off drive unit is disposed at a position closer to the fluidization tank than the lifting drive unit,
The fluidized bed dip coating apparatus according to claim 1 or 2, wherein the transport jig holding unit is disposed closer to the fluidized bed than the shake-off drive unit. (a) heating an electrical conductor at a first temperature;
(b) after the step (a), a step of lowering the conductor from above the fluidization tank in which the powder paint is fluidized by a lifting drive unit to immerse the conductor in the powder paint, thereby adhering the powder paint to the conductor;
(c) after the step (b), lifting the conductor from the powder paint by the lifting drive unit and applying acceleration to the conductor alternately in an upward and downward direction ,
The application of acceleration to the conductor in step (c) is performed by a shaking-off drive unit that is provided on the lifting and lowering part of the lifting drive unit, which raises and lowers the object to be coated together with the transport jig that suspends the object to be coated, and vibrates the transport jig in the vertical direction . The method for manufacturing a wiring member having an insulating coating according to claim 4, further comprising: (d) a step of heating the conductor to which the powder coating is applied at a second temperature after step (c). The method for manufacturing a wiring member having an insulating coating according to claim 4 or 5, wherein in step (c), acceleration is applied alternately in the upward and downward directions to the conductor at a height within the fluidization tank where the conductor does not come into contact with the powder paint flowing within the fluidization tank. A method for manufacturing a wiring member having an insulating coating according to any one of claims 4 to 6, wherein in step (b), the conductor is vibrated in an up-and-down direction while immersed in the powder coating. the shake-off drive unit vibrates the conveying jig in the up-and-down direction at a position closer to the fluidization tank than the position of the lifting drive unit;
The method for manufacturing a wiring member having an insulating coating according to any one of claims 4 to 7, wherein the transport jig holding unit holds the transport jig at a position closer to the flow tank than the shake-off drive unit.