JP7617621B2 - Plated parts - Google Patents

Description

The present invention relates to a plated part in which a plating process is applied to a part having a through hole.

There is a plated part in which a plating process is applied to the inner peripheral surface, which is formed so that the inner diameter of the cylindrical part gradually changes in the axial direction. In this plated part, the thickness of the plating film is also gradually changed (for example, Patent Document 1).

Japanese Patent Application Publication No. 11-302895

In the case of Patent Document 1, the thickness of the plating film applied to the inner peripheral surface gradually increases or decreases in the axial direction, and the thickness of the plating film at one of the aperture portions is thicker than that at the inside in the axial direction. This can cause inconvenience when using the resulting plated parts, and there is room for improvement.

The present invention was made in consideration of the above problems, and relates to a plated component in which a plating layer of an appropriate thickness is applied to the inner surface of a circular through hole.

The present invention relates to a plated component in which a plating layer is applied to the inner surface of a circular through hole of a workpiece having a circular through hole with both ends open, characterized in that a tapered expanded diameter portion that expands in diameter toward the opening is formed on each of the two ends of the inner surface of the circular through hole, the thickness of the plating layer is thicker toward the center than at both ends of the circular through hole when viewed in the depth direction from both ends of the circular through hole, and the thickness of the plating layer in the expanded diameter portion is thicker on the inner back side than on the opening side of the expanded diameter portion .

The technology provided by the present invention makes the plating layer thicker on the center side than on both edges of the circular through hole, so that when the resulting plated part is used, for example, when inserting a shaft rod into the circular through hole from either open end, it is possible to reduce catching resistance.

FIG. 2 is a diagram showing the appearance of a cylindrical part (a part to be machined). 1 is a cross-sectional view of a circular through hole of a cylindrical part cut in the length direction. 1 is a cross-sectional view of a cylindrical part having a circular through hole with an enlarged diameter portion provided at the edge thereof. FIG. 1 is a conceptual diagram showing an example of a plating processing apparatus that is applied when producing a plated component of the present invention. FIG. 1 is a conceptual diagram showing an example of a plating processing apparatus that is applied when producing a plated component of the present invention. 1 is a diagram showing the positions of symbols attached to the inner peripheral surface of a circular through hole of the present invention. FIG. 1 is a diagram showing the thickness of a plating film 30 applied to a circular through hole 20 of the component (Example 1). FIG. FIG. 11 is a diagram showing the thickness of a plating film 30 applied to a circular through hole 20 of the component (Example 2). 13 is a diagram showing the thickness of a plating film 30 applied to the enlarged diameter portion 21 of the contact portion (upper surface) 11 of the circular through hole 20 of the component in Example 2. FIG. 13 is a diagram showing the thickness of a plating film 30 applied to the enlarged diameter portion 22 of the contact portion (bottom surface) 12 of the circular through hole 20 of the component in Example 2. FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, an overview of this embodiment will be described.
The plated part 10 of this embodiment (hereinafter, may be referred to as this part) is a part in which a plating layer is applied to the inner circumferential surface of a circular through hole 20 with both ends open, which is formed in a cylindrical workpiece 10 shown in Fig. 1. The size of the cylindrical workpiece 10 is not limited, but in this embodiment, the cylindrical workpiece 10 has a diameter of about 20 mm at the abutment portion (top surface) 11 and the abutment portion (bottom surface) 12, and a length of about 50 mm. The cylindrical workpiece 10 is made of a metal material, and the type of metal may be a specific metal or an alloy. In this embodiment, the cylindrical workpiece 10 is made of an iron-based alloy such as steel.
1, the circular through hole 20 is a cylindrical hole formed vertically from the center of the abutment portion (top surface) 11 of the cylindrical workpiece 10 toward the abutment portion (bottom surface) 12. The ratio of the outer diameter of the cylindrical workpiece 10 to the outer diameter of the circular through hole 20 may be any value. In this embodiment, the cylindrical workpiece 10 used has a circular through hole 20 with a diameter of about 2 mm.
The outer and inner circumferential surfaces of the cylindrical workpiece 10 may be processed in any manner, but it is preferable that the surfaces are processed to a high degree of surface precision by cutting, grinding, polishing, etc. This is because the surface roughness of the workpiece to be plated has a large effect on the finish of the plating and the corrosion resistance.
The types of plating that can be applied to the cylindrical workpiece 10 include chrome plating, hard chrome plating, nickel plating, zinc plating, gold plating, silver plating, etc. In this embodiment, the plating process is performed using chrome plating.

A cross-sectional view of a cylindrical workpiece 10 is shown in Fig. 2. Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1. As shown in Fig. 2, a circular through-hole 20 is provided with a constant diameter from the center of abutment portion (top surface) 11 of the cylindrical workpiece 10 toward abutment portion (bottom surface) 12.
As shown in Fig. 3, tapered enlarged diameter portions 21 and 22 are provided on both edges of the circular through hole 20. The enlarged diameter portion 21 is on the contact portion (upper surface) 11 side, and the enlarged diameter portion 22 is on the contact portion (upper surface) 12 side, with a flat portion 23 provided between them. In the circular through hole 20 of this embodiment, the diameter of the flat portion 23 is about 2 mm, and the end diameters of the enlarged diameter portions 21 and 22 are formed to be larger than 2 mm.

The plating processing apparatus 200 of this embodiment will be described with reference to FIG.
A cylindrical workpiece 10 and electrodes (anode and cathode) are immersed in a plating tank 100 containing a plating solution, and a current is passed through the electrodes to form a plating film on the cylindrical workpiece 10 by electrolytic plating to produce a plated part 10. In this embodiment, a chromium oxide solution is used as the plating solution.
Here, a method for providing the cylindrical workpiece 10 and electrodes in the plating processing apparatus 200 will be described.
As shown in Fig. 4, a cylindrical workpiece 10 is placed on a metal cathode 120. A plurality of cylindrical workpieces 10 are placed on the cathode 120 so that a plating film can be applied to the plurality of cylindrical workpieces 10 at the same time. At this time, a resin spacer (not shown) is provided between the cylindrical workpieces 10 so that they do not come into contact with each other. The state in which the cylindrical workpieces 10 are placed on the cathode 120 is shown in Fig. 5.
As shown in FIG. 5, when a cylindrical workpiece 10 is placed on a metal cathode 120 having a concave shape, the cylindrical workpiece 10 and the cathode 120 are in contact with each other, so that the cathode 120 and the cylindrical workpiece 10 are electrically connected, and it becomes possible to apply a plating film 30 to the cylindrical workpiece 10. In addition, by making the cathode 120 concave, the cylindrical workpiece 10 can be contacted at two or more points, and thus the cylindrical workpiece 10 can be stably placed. Therefore, it becomes possible to apply a high-quality plating film to the inner circumferential surface of the circular through hole 20. In addition, by making the cathode 120 concave, a gap is provided between the cathode 120 and the cylindrical workpiece 10, and thus the cylindrical workpiece 10 can be placed in a state in which the plating liquid can flow. By placing the cylindrical workpiece 10 in this manner, it becomes possible to apply a high-quality plating film.
Then, as shown in FIG. 4, the anode 110 is provided so as to penetrate the circular through-hole 20 of the cylindrical workpiece 10. In this embodiment, the anode 110 can be, for example, a thin wire made of a metal material. However, the material used for the anode 110 is not limited to this. In this embodiment, the anode 110 is a thin wire with a diameter of about 0.5 mm. By adopting the thin wire anode 110 in this manner, it is easy to penetrate and arrange it in the circular through-hole 20. In addition, for example, both ends of the anode 110 that penetrates the circular through-holes 20 of a plurality of cylindrical workpieces 10 are provided on a predetermined plate member, and the plate member is warped, so that the anode 110 can be arranged at a predetermined position (predetermined axis) of the circular through-hole 20 without bending. This makes it possible to apply a high-quality plating film 30 to the inner peripheral surface of the cylindrical workpiece 10.
By performing plating processing using such a plating processing device 200, it is possible to apply a high-quality plating film 30 to the inner surface of the circular through hole 20 of the cylindrical workpiece 10 placed within the plating processing device 200.

Here, the anode 110 used in this embodiment will be further described.
As described above, in this embodiment, a thin wire of a metal material is used for the anode 110, but when the anode 110 is inserted through the circular through hole 20 of the cylindrical workpiece 10 and installed, the anode 110 facing the position where the plating layer on the inner periphery of the circular through hole 20 is to be thicker is used. That is, although the anode 110 is a thin wire, the thickness (diameter) is not uniform, and when the cylindrical workpiece 10 is installed, the anode 110 is used such that the anode 110 facing the center side is thicker than the positions facing both ends of the circular through hole 20. By using such an anode 110, the distance between the inner periphery of the circular through hole 20 and the anode 110 is shorter at the position facing the center side than at the positions facing both ends of the circular through hole 20, so that plating grows more easily and it becomes possible to apply a thick plating film 30 to the center side. In addition, as will be described in detail later, in this component, the plating film 30 is made thicker at the position facing the center side than at the positions facing both ends of the circular through hole 20, and the thickness of the plating film 30 varies depending on the position of the enlarged diameter portions 21, 22. This is also made possible by adjusting the distance between the inner circumferential surface of the circular through hole 20 and the anode 110 by adjusting the thickness of the anode 110.

Next, the thickness of the plating film 30 applied to the inner peripheral surface of the circular through hole 20 of the plated component 10 produced in this embodiment will be described with reference to Figures 7 to 10. The thickness of the plating film 30 applied to the inner peripheral surface of the circular through hole 20 of the plated component 10 produced was observed under a microscope, and the results are shown in Figures 7 to 10.
As shown in FIG. 3, the circular through hole 20 of the cylindrical workpiece 10 has tapered enlarged diameter portions 21 and 22 on both edges. A flat portion 23, in which the diameter of the circular through hole 20 is constant, is provided between the enlarged diameter portions 21 and 22. For the sake of explanation, symbols A1 to A5, B to F, and G1 to G5 are attached to positions from edge to edge on the inner circumferential surface of the circular through hole 20 as shown in FIG. 6. Note that A1 to A5 and G1 to G5 are symbols attached to the enlarged diameter portions 21 and 22, respectively, and B to F are symbols attached to the flat portion 23. Also, the plating film 30 shown in FIG. 6 is depicted as having a uniform thickness, but the thickness of the actual plating film 30 may vary depending on the position on the inner circumferential surface of the circular through hole 20.

Example 1
FIG. 7 shows the results of measuring the thickness of the plating film 30 applied to the inner surface of the circular through hole 20 of the plated component 10 produced by plating only the inner surface of the circular through hole 20 at various positions on the inner surface.
As is clear from FIG. 7 , the thickness of the plating film 30 is formed to be thicker on the central side (e.g., flat portion 23) than on the edge portions (e.g., enlarged diameter portion 21 on the abutment surface (top surface) 11 side and enlarged diameter portion 22 on the abutment surface (bottom surface) 12 side).
The plating film 30 thus applied has the following effects. When the axial rod is inserted into the circular through hole 20 of the plated component 10, the catching resistance near the entrance (edge) can be suppressed. In addition, in order to suppress the catching when inserting the axial rod into the circular through hole 20, the enlarged diameter portions 21 and 22 are provided near the entrance, and the catching resistance near the entrance (edge) can be suppressed by both the shape of the circular through hole 20 and the thickness of the plating film 30. Furthermore, by applying the plating film 30 so that the thickness gradually increases from the opening end (A1 or G5 shown in FIG. 6) toward the innermost end (A5 or G1 shown in FIG. 6) in the enlarged diameter portions 21 and 22, the catching resistance near the entrance (edge) can be further suppressed. In addition, by providing a portion where the plating film 30 is thick on the central side (for example, the flat portion 23), the rattling of the axial rod inserted into the circular through hole 20 can be suppressed. In addition, by providing a thicker portion of the plating film 30 near the center of the central portion, it is possible to better avoid interference between the inner surface of the circular through hole 20 and the axial rod even if axial wobble occurs in the axial rod, compared to when this thicker portion is formed near the end portion rather than near the center of the flat portion 23.

The thickness of the plating film 30 in the region including the center in the depth direction of the flat portion 23 (from C to E in FIG. 6) gradually increases in one direction. In this way, when the thickness of the plating film 30 is formed to be thicker toward the center than at both ends, the thickness is gradually increased, which makes it possible to efficiently rotate the plated component 10 with respect to the shaft rod. Similarly, when the plated component 10 is fixed and the shaft rod is rotated, the shaft rod can be efficiently rotated.
As is clear from Fig. 7, the position (E in Fig. 6) where the thickness of the plating film 30 is maximum in the flat portion 23 is biased toward one side from the center in the depth direction. This has the following effects. For example, when a shaft rod inserted through the plated component 10 is rotated, axial wobble may occur. However, by providing the position where the plating film 30 is maximum in thickness, which is formed at a position biased toward one side from the center, on the side where axial wobble occurs, it is possible to suppress axial wobble. Therefore, the position (direction) where the plated component 10 is provided can be selected depending on the environment in which the plated component 10 is used, so that the plated component 10 can be used universally.

Example 2
Figures 8 to 10 are diagrams showing the results of simultaneously plating the inner surface of the circular through hole 20, the enlarged diameter portion 21 on the abutment surface (top surface) 11 side, and the enlarged diameter portion 22 on the abutment surface (bottom surface) 12 side, and measuring the thickness of the plating film 30 applied to the inner surface of the circular through hole 20 of the plated component 10 at various positions on the inner surface.
As shown in Fig. 8, similarly to Fig. 7, the plating film 30 is formed thicker on the central side (e.g., flat portion 23) than on the edge (e.g., enlarged diameter portion 21 on the abutment surface (top surface) 11 side and enlarged diameter portion 22 on the abutment surface (bottom surface) 12). In addition, by gradually increasing the thickness of the plating film 30 from the opening end (A1 or G5 shown in Fig. 6) toward the innermost end (A5 or G1 shown in Fig. 6) in the enlarged diameter portions 21 and 22, it is possible to further suppress the catching resistance near the entrance (edge). In addition, by providing a portion where the plating film 30 is thicker on the central side (e.g., flat portion 23), it is possible to suppress the rattling of the shaft rod inserted into the circular through hole 20. In addition, by providing a thicker portion of the plating film 30 near the center of the central portion, it is possible to better avoid interference between the inner surface of the circular through hole 20 and the axial rod even if axial wobble occurs in the axial rod, compared to when this thicker portion is formed near the end portion rather than near the center of the flat portion 23.

The thickness of the plating film 30 in the region including the center in the depth direction of the flat portion 23 (from C to E in FIG. 6) gradually increases in one direction. In this way, when the thickness of the plating film 30 is formed to be thicker toward the center than at both ends, by gradually increasing the thickness in one direction, it becomes possible to efficiently rotate the plated component 10 with respect to the shaft rod. Similarly, when the plated component 10 is fixed and the shaft rod is rotated, it becomes possible to efficiently rotate the shaft rod.
As is clear from Fig. 8, the position (C in Fig. 6) where the thickness of the plating film 30 is maximum in the flat portion 23 is biased toward one side from the center in the depth direction. This has the following effects. For example, when a shaft rod inserted through the plated component 10 is rotated, axial wobble may occur. However, by providing the position where the plating film 30 is maximum in thickness, which is formed at a position biased toward one side from the center, on the side where axial wobble occurs, it is possible to suppress axial wobble. Therefore, the position (direction) where the plated component 10 is provided can be selected depending on the environment in which the plated component 10 is used, so that the plated component 10 can be used universally.

FIG. 9 is a diagram showing in detail the thickness of the plating film 30 of the enlarged diameter portion 21 on the abutment surface (top surface) 11 side, and FIG. 10 is a diagram showing in detail the thickness of the plating film 30 of the enlarged diameter portion 22 on the abutment surface (bottom surface) 12 side.
As is clear from FIG. 9, the thinnest region (e.g., A3) is formed between the open end (e.g., A1) and the innermost end (e.g., A5) of the enlarged diameter portion 21. Similarly, as is clear from FIG. 10, the thinnest region (e.g., G4) is formed between the open end (e.g., G5) and the innermost end (e.g., G1) of the enlarged diameter portion 22. In this way, by making the plated film 30 at the open end (e.g., A1) of the enlarged diameter portion 21 and the open end (e.g., G5) of the enlarged diameter portion 22 thick, it is possible to prevent chipping of the plating at the edge portion, which may occur when inserting the shaft rod. Furthermore, although the plated film 30 at the open end is made thick, it is possible to secure the hole diameter of the enlarged diameter portion 21 and the enlarged diameter portion 22 by forming a thin region once and gradually increasing the thickness from the thin region (e.g., A3 or G4). Furthermore, even if the plating film 30 is made thicker at the open ends of the enlarged diameter portions 21 and 22, a thin region is provided, so that the hole diameter of the enlarged diameter portions 21 and 22 can be ensured.

The present invention is not limited to the above-described embodiment, and various modifications and improvements are possible.
In this embodiment, the distance between the inner peripheral surface of the circular through hole 20 and the anode 110 is adjusted according to the thickness of the anode 110, so that the plating film 30 of different thicknesses is applied to the inner peripheral surface of the circular through hole 20, but this is not limited thereto. For example, by forming a thin oxide film on the surface of the anode 110 facing both ends (positions where the plating film 30 is thinly applied) of the inner peripheral surface of the circular through hole 20, the part where the oxide film is formed has a higher electrical resistance than the part where the oxide film is not formed, so that the amount of electricity passing through the part where the oxide film is not formed is larger. As a result, it is possible to apply a thicker plating film 30 to the inner peripheral surface of the circular through hole 20 facing the part where the oxide film is not formed, compared to the inner peripheral surface of the circular through hole 20 facing the part where the oxide film is formed. In this way, the electrical resistance of the surface of the anode 110 may be adjusted to apply a plating film 30 of different thicknesses to the inner peripheral surface of the circular through hole 20.

In this embodiment, the generated plated part 10 is rotated for use, but this is not limited to the above, and the part may be used in a fixed state. Also, the shape of the part 10 to be machined and the shape of the circular through hole 20 are merely examples, and other shapes may be used.

<Additional Notes>
The above embodiment encompasses the following technical ideas.
(1) A plated component having a circular through hole with both ends open formed in a workpiece, the circular through hole having an inner peripheral surface coated with a plating layer,
A plated component, characterized in that the thickness of the plating layer is thicker at a center portion of the circular through hole than at both ends of the circular through hole when viewed in a depth direction from both ends of the circular through hole.
(2) A plated component as described in (1), characterized in that a tapered enlarged diameter portion that enlarges in diameter toward the opening is formed at each of the two ends of the inner surface of the circular through hole, and the thickness of the plating layer in the enlarged diameter portion is thicker on the inner back side than on the opening side of the enlarged diameter portion.
(3) A plated component as described in (2), characterized in that the thickness of the plating layer in the enlarged diameter portion increases monotonically from the opening end of the enlarged diameter portion toward the innermost end thereof.
(4) A plated component as described in (2), characterized in that the plating layer in the enlarged diameter portion has a region of thinnest thickness between the opening end and the innermost end of the enlarged diameter portion.
(5) A plated component described in any one of (2) to (4), characterized in that a flat portion is formed on the inner surface of the circular through hole between one of the enlarged diameter portions and the other of the enlarged diameter portions, and the thickness of the plating layer in a region including the center of the depth direction in the flat portion gradually increases in one direction.
(6) A plated component as described in (5), characterized in that the position where the thickness of the plating layer is maximum in the flat portion is biased toward the one direction from the center portion in the depth direction.

10: Part to be processed/Part to be plated 11: Contact surface (upper surface)
12 Contact surface (bottom surface)
20 Circular through hole 21 Enlarged diameter portion on the contact surface (top surface) side 22 Enlarged diameter portion on the contact surface (bottom surface) side 23 Flat portion 30 Plating film 100 Plating tank 110 Anode 120 Cathode 200 Plating processing device

Claims (5)

A plated component is provided in which a plated layer is applied to an inner peripheral surface of a circular through hole of a workpiece having a circular through hole with both ends open,
a tapered portion having a diameter increasing toward the opening is formed on each of the two ends of an inner circumferential surface of the circular through hole,
A plated component characterized in that the thickness of the plating layer is thicker at the center than at both ends of the circular through hole when viewed in the depth direction from both ends of the circular through hole, and the thickness of the plating layer in the enlarged diameter portion is thicker on the inner back side than on the opening side of the enlarged diameter portion . 2. The plated component according to claim 1 , wherein the thickness of the plating layer in the enlarged diameter portion increases monotonically from the open end of the enlarged diameter portion toward the innermost end thereof. 2. The plated component according to claim 1 , wherein the plating layer in the enlarged diameter portion has a region having a thinnest thickness between an open end and an innermost end of the enlarged diameter portion. A plated component as described in any one of claims 1 to 3, characterized in that a flat portion is formed on the inner surface of the circular through hole between one of the enlarged diameter portions and the other of the enlarged diameter portions, and the thickness of the plating layer in a region including the center portion in the depth direction of the flat portion gradually increases in one direction. 5. The plated component according to claim 4 , wherein the position where the thickness of the plating layer is maximum in the flat portion is biased toward the one direction from the center portion in the depth direction.

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