Cylinder device, metal sliding component, and method for producing metal sliding component

Patent metadata

Field	Value
Publication number	US-12049707-B2
Application number	US-202017621416-A
Country	US
Kind code	B2
Filing date	Jun 5, 2020
Priority date	Jun 26, 2019
Publication date	Jul 30, 2024
Grant date	Jul 30, 2024

Abstract

This cylinder device includes a tubular cylinder that has an opening portion on at least one end side, a metal rod that protrudes through the opening portion of the cylinder, and a sliding contact member that is provided at the opening portion of the cylinder and comes into sliding contact with the rod. A chromium plating film is provided on a surface of the rod. An aspect ratio of an average crystallite diameter in a film thickness direction to an average crystallite diameter in an in-plane direction in the chromium plating film is 0.2 or smaller.

First claim

The invention claimed is:

1. A cylinder device comprising:
a tubular cylinder that has an opening portion on at least one end side;
a metal rod that protrudes through the opening portion of the cylinder; and
a sliding contact member that is provided at the opening portion of the cylinder and comes into sliding contact with the rod,
wherein a chromium plating film is provided on a surface of the rod, and
wherein an aspect ratio of an average crystallite diameter in a film thickness direction to an average crystallite diameter in an in-plane direction in the chromium plating film is 0.2 or smaller.

2. The cylinder device according to claim 1 ,
wherein the average crystallite diameter of the crystallites in the in-plane direction is 60 nm or larger.

3. The cylinder device according to claim 1 ,
wherein the crystallites have a crystal orientation which becomes a preferred azimuth in which (111) planes are aligned in the in-plane direction.

4. A metal sliding component comprising:
a chromium plating film on a surface of a metal base material,
wherein an aspect ratio of an average crystallite diameter in a film thickness direction to an average crystallite diameter in an in-plane direction of crystallites in the chromium plating film is 0.2 or smaller.

5. The metal sliding component according to claim 4 ,
wherein the average crystallite diameter of the crystallites in the in-plane direction is 60 nm or larger.

6. The metal sliding component according to claim 4 ,
wherein the crystallites have a crystal orientation which becomes a preferred azimuth in which (111) planes are aligned in the in-plane direction.

7. The metal sliding component according claim 4 ,
wherein the metal base material is a rod.

8. A method for producing a metal sliding component comprising:
a step of forming a chromium plating film in which an aspect ratio of an average crystallite diameter in a film thickness direction to an average crystallite diameter in an in-plane direction of crystallites is 0.2 or smaller,
wherein the step of forming a chromium plating film comprises a step of immersing a metal base material in a plating solution having a temperature of 60° C. or higher on a flowing terminal side and an outlet temperature of 90° C. or lower, and
a step of applying a current to the plating solution.

9. The method for producing a metal sliding component according to claim 8 ,
wherein the step of applying a current includes a step of applying a current density becomes 350 ASD or higher when the metal base material is immersed in the plating solution and a current is applied thereto.

10. The method for producing a metal sliding component according to claim 8 ,
wherein a plating film is formed using a plating solution containing 99 mass % or more of chromium as the plating solution.

11. The method for producing a metal sliding component according to claim 8 ,
wherein a plating solution containing an organic sulfonic acid is used as the plating solution.

12. The method for producing a metal sliding component according to claim 8 ,
wherein the average crystallite diameter of the crystallites in the in-plane direction is caused to be 60 nm or larger.

13. The method for producing a metal sliding component according to claim 8 ,
wherein the crystallites have a crystal orientation which becomes a preferred azimuth in which (111) planes are aligned in the in-plane direction.

Assignees

• Hitachi Astemo Ltd

Inventors

• OHNUKI Takuma
• Nakano Hiroshi

Classifications

• C25D7/04

  Tubes; Rings; Hollow bodies · CPC title

• C25D5/617

  Crystalline layers · CPC title

• F16F9/32

  Details · CPC title

• C25D3/10 Primary

  characterised by the organic bath constituents used · CPC title

• C25D7/10

  Bearings · CPC title