Ball joint and method for manufacturing ball joint

Patent metadata

Field	Value
Publication number	US-10495139-B2
Application number	US-201615571916-A
Country	US
Kind code	B2
Filing date	Mar 1, 2016
Priority date	May 11, 2015
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

This ball join includes a ball stud with a spherical ball section and a shaft-shaped shaft section and a holder that rotatably bolds the ball section, and has a machining surface subjected to cutting in a welded portion obtained by welding the ball section and the shaft section, and the machining surface has a curve-shaped first corner section. In addition, a method for manufacturing this ball joint includes a welding step of welding the ball section and the shaft section and a cutting step of forming the machining surface by subjecting the welded portion obtained by welding the ball section and the shaft section to cutting, and the cutting step executes processing including forming the curve-shaped first corner section on the machining surface. Consequently, a ball joint with a large oscillation angle can be obtained.

First claim

The invention claimed is:

1. A ball joint comprising:
a ball stud with a spherical ball section and a shaft-shaped shaft section;
a holder that rotatably holds the ball section;
a welded portion obtained by welding the ball section and the shaft section; and
a machining surface subjected to cutting formed on the ball stud, the holder, and the welded portion,
wherein the machining surface has a curve-shaped first corner section,
wherein the shaft section of the ball stud comprises: a truncated-cone-shaped section in a truncated cone shape; a collar-shaped flange section; and a recess formed between the truncated-cone-shaped section and the flange section,
the truncated-cone-shaped section and the recess are connected to each other with a curve-shaped second corner section,
the first corner section is formed larger in curvature radius than the second corner section, and
wherein the first corner section is formed axially between and adjacent to the welded portion and the ball stud.

2. The ball joint according to claim 1 , wherein at least a part of the first corner section is arranged on the ball section.

3. A ball joint comprising:
a ball stud with a spherical ball section and a shaft-shaped shaft section;
a holder that rotatably holds the ball section;
a welded portion obtained by welding the ball section and the shaft section; and
a machining surface subjected to cutting formed on the ball stud, the holder, and the welded portion,
wherein the machining surface has a curve-shaped first corner section,
wherein a metallic structure at a central part of the welded portion obtained by welding the ball section and the shaft section indicates a sign that fine pearlite is precipitated in a crystal grain boundary, and
wherein the first corner section is formed axially between and adjacent to the welded portion and the ball stud.

4. The ball joint according to claim 3 , wherein at least a part of the first corner section is arranged on the ball section.

5. A method for manufacturing a ball joint comprising: a ball stud with a spherical ball section and a shaft-shaped shaft section; and a holder that rotatably holds the ball section, the method including:
a welding step of welding the ball section and the shaft section; and
a cutting step of forming a machining surface formed on the ball stud, the holder, and the welded portion by subjecting a welded portion obtained by welding the ball section and the shaft section to cutting,
wherein the cutting step subjects the machining surface to processing including a step of forming a curve-shaped first corner section,
wherein the welding step executes processing for precipitating fine pearlite in a crystal grain boundary of a metallic structure by cooling after welding at a central part of the welded portion obtained by welding the ball section and the shaft section, and
wherein the first corner section is formed axially between and adjacent to the welded portion and the ball stud.

Assignees

• Thk Co Ltd

Inventors

• Nishide Tetsuhiro
• Horie Takuya
• Kashiwagura Satoshi

Classifications

• F16C11/0609 Primary

  made from two or more parts · CPC title

• F16C11/0614

  the female part of the joint being open on two sides · CPC title

• F16C11/0633

  the linings being made of plastics · CPC title

• F16C2226/36

  by welding · CPC title

• Y10T29/49666

  with metallurgical bonding · CPC title