Sliding component, method for producing sliding component, and device for producing sliding component

Patent metadata

Field	Value
Publication number	US-10384301-B2
Application number	US-201315023739-A
Country	US
Kind code	B2
Filing date	Oct 16, 2013
Priority date	Oct 16, 2013
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

A piston shoe as a sliding component includes a base section, which is made of steel, and a sliding section having a sliding surface, which is made of copper alloy and joined to the base section. The base section and the sliding section are joined, with a base section joint region being formed in the base section, the base section joint region including a base section joint surface that is a surface joined to the sliding section and having smaller grains than other regions in the base section.

First claim

The invention claimed is:

1. A sliding component, comprising:
a sliding section having a sliding surface, and made of copper alloy; and
a base section made of steel or cast iron, and joined to the sliding section,
the base section, including:
a base section joint surface that is a surface joined to the sliding section; and
a base section joint region including the base section joint surface and having smaller grains than other regions in the base section,
wherein the base section joint region has a thickness, in a direction perpendicular to the base section joint surface, that is greater in a region including an outer surface of the sliding component than in an inside of the sliding component, and

the sliding section including:
a sliding section joint surface that is a surface joined to the base section; and
a sliding section joint region including the sliding section joint surface and having a lower hardness than other regions in the sliding section,
wherein the sliding section joint region has a thickness, in a direction perpendicular to the sliding section joint surface, that is smaller than the thickness of the base section joint region.

2. The sliding component according to claim 1 , wherein the sliding section joint region has a thickness of 0.2 mm or less in the direction perpendicular to the sliding section joint surface.

3. The sliding component according to claim 1 , wherein the copper alloy is high-strength brass.

4. The sliding component according to claim 3 , wherein
the high-strength brass constituting the sliding section includes precipitates having a higher hardness than a matrix, and
the precipitates in the sliding section joint region are smaller in size than the precipitates in other regions in the sliding section.

5. The sliding component according to claim 4 , wherein the sliding section joint region includes a precipitate aggregate as an aggregate of the precipitates in a region, within the sliding section joint region, that is in contact with the sliding section joint surface.

6. The sliding component according to claim 3 , wherein the sliding section joint region has a higher volume fraction of a phase than other regions in the sliding section.

7. The sliding component according to claim 1 , wherein the sliding section joint region has a thickness in the direction perpendicular to the sliding section joint surface that is substantially the same in the region including an outer surface of the sliding component and in an inside of the sliding component.

8. A method for producing a sliding component, comprising the steps of:
preparing a base member made of steel or cast iron and a sliding member made of copper alloy;
heating a region, within the base member, including a base member contact surface that is a surface of the base member coming into contact with the sliding member to a temperature not lower than the A 1 transformation point by causing the base member brought into contact with the sliding member to slide relatively to the sliding member to generate frictional heat; and
joining the base member and the sliding member by letting the region including the base member contact surface cooled to a temperature lower than the A 1 transformation point in the state where the heated base member is held in contact with the sliding member,
wherein in the step of heating the region including the base member contact surface to a temperature not lower than the A 1 transformation point and in the step of joining the base member and the sliding member, the sliding member is restrained on an outer peripheral side of a sliding member contact surface that is a surface of the sliding member coming into contact with the base member,
wherein the base member includes a base member joint surface that is a surface joined to the sliding member and a base member joint region including the base member joint surface and having smaller grains than other regions in the base member, the base member joint region having a thickness, in a direction perpendicular to the base member joint surface, that is greater in a region including an outer surface of the sliding component than in an inside of the sliding component, and
wherein the sliding member includes a sliding member joint surface that is a surface joined to the base member and a sliding member joint region including the sliding member joint surface and having a lower hardness than other regions in the sliding member, the sliding member joint region having a thickness, in a direction perpendicular to the sliding member joint surface, that is smaller than the thickness of the base member joint region.

9. The method for producing a sliding component according to claim 8 , wherein in the step of heating the region including the base member contact surface to a temperature not lower than the A 1 transformation point, the base member rotates relatively to the sliding member while being pressed against the sliding member, without changing its position relative to the sliding member.

10. The method for producing a sliding component according to claim 8 , wherein the copper alloy is high-strength brass.

11. The method for producing a sliding component according to claim 10 , further comprising the step of forming, in a region, within the sliding member, that is in contact with the sliding member contact surface, a region having a higher volume fraction of a phase than other regions in the sliding member by heating the sliding member in the state where the base member and the sliding member are joined.

Assignees

• Komatsu Mfg Co Ltd

Inventors

• Shibata Yoshitaka
• Amano Masaharu
• Tsumura Takuya
• Nakata Kazuhiro

Classifications

• F04B27/0886

  Piston shoes · CPC title

• F04B1/124

  Pistons · CPC title

• F03C1/0605

  Adaptations of pistons (pump pistons F04B1/124, F04B53/14) · CPC title

• B23K20/12 Primary

  the heat being generated by friction; Friction welding · CPC title

• F04B1/126

  Piston shoe retaining means · CPC title