Stepped pipe member and stepped pipe member production method

Patent metadata

Field	Value
Publication number	US-11774013-B2
Application number	US-201816623555-A
Country	US
Kind code	B2
Filing date	Jul 5, 2018
Priority date	Jul 6, 2017
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

Formed in series along an axial-direction end portion of a large-diameter pipe member, in the following order from the pipe end, are: a large-diameter-pipe pipe-end expanding portion; a large-diameter-pipe reduced-diameter portion; a large-diameter-pipe bulging portion; and a tapered portion. Formed in series along an axial-direction end portion of a small-diameter-pipe member, in the following order from the pipe end, are: a small-diameter-pipe pipe-end expanding portion; a small-diameter-pipe enlarged-diameter portion; and a small-diameter-pipe bulging portion. The outer cylindrical surface of the small-diameter-pipe enlarged-diameter portion is in close contact with the inner circumferential surface of the large-diameter-pipe reduced-diameter portion; the inner cylindrical surface of the large-diameter-pipe bulging portion and the outer circumferential surface of the small-diameter-pipe pipe-end expanding portion are engaged; and the inner circumferential surface of the large-diameter-pipe pipe-end expanding portion and the outer cylindrical surface of the small-diameter-pipe bulging portion are engaged.

First claim

The invention claimed is:

1. A stepped pipe member comprising:
a connection in which one end portion of a large-diameter pipe member in an axial direction is secured to one end portion, in the axial direction, of a small-diameter pipe member having a smaller outer diameter than an outer diameter of the large-diameter pipe member,
wherein a large-diameter-pipe pipe-end expanding portion, a large-diameter-pipe reduced-diameter portion having a smaller outer diameter than an outer diameter of the large-diameter-pipe pipe-end expanding portion, a large-diameter-pipe bulging portion having a shape characteristic of a Lorentz force generated inside of the respective pipe members at a time when the small diameter pipe member is inserted in the large-diameter pipe member, and a larger maximum outer diameter than the outer diameter of the large-diameter-pipe reduced-diameter portion, and a tapered portion having a maximum outer diameter which is larger than the maximum outer diameter of the large-diameter-pipe bulging portion, and a minimum outer diameter which is smaller than the maximum outer diameter of the large-diameter-pipe bulging portion, are formed at the one end portion, in the axial direction, of the large-diameter pipe member so as to be continuous with one another in this order from a pipe end,
wherein a small-diameter-pipe pipe-end expanding portion, a small-diameter-pipe enlarged-diameter portion having a smaller outer diameter than an outer diameter of the small-diameter-pipe pipe-end expanding portion, and a small-diameter-pipe bulging portion having a shape characteristic of a Lorentz force generated inside of the respective pipe members at a time when the small-diameter pipe member is inserted in the large-diameter pipe member, and a larger outer diameter than the outer diameter of the small-diameter-pipe enlarged-diameter portion are formed at the one end portion, in the axial direction, of the small-diameter pipe member so as to be continuous with one another in this order from a pipe end,
wherein an inner circumferential surface of the large-diameter-pipe reduced-diameter portion is in close contact with an outer circumferential surface of the small-diameter-pipe enlarged-diameter portion,
wherein an inner circumferential surface of the large-diameter-pipe bulging portion is engaged with an outer circumferential surface of the small-diameter-pipe pipe-end expanding portion, and
wherein an inner circumferential surface of the large-diameter-pipe pipe-end expanding portion is engaged with an outer circumferential surface of the small-diameter-pipe bulging portion,
wherein a stiffener is secured to an outer circumferential surface of the large-diameter-pipe reduced-diameter portion and
wherein a length from a top of the lame-diameter-pipe bulging portion to the stiffener is larger than an expanding length defined by a free end of the small-diameter-pipe pipe-end expanding portion from the stiffener.

2. The stepped pipe member according to claim 1 , wherein the expanding length of the small-diameter pipe pipe-end expanding portion from the stiffener is 5% to 30% of a width of the stiffener in the axial direction.

3. The stepped pipe member according to claim 1 , wherein a length from a top of the small-diameter-pipe bulging portion to the stiffener is larger than an expanding length of the large-diameter-pipe pipe-end expanding portion from the stiffener.

4. The stepped pipe member according to claim 1 , wherein an expanding length of the large-diameter-pipe pipe end expanding portion from the stiffener is 5% to 30% of a width of the stiffener in the axial direction.

5. The stepped pipe member according to claim 1 , wherein a thickness of the large-diameter-pipe member is larger than a thickness of the small-diameter-pipe member.

Assignees

• Kobe Steel Ltd
• Toyota Motor Co Ltd

Inventors

• Imamura Yoshihaya
• Imai Chieko

Classifications

• F16L13/141 Primary

  by crimping or rolling from the outside · CPC title

• B21D51/16

  characterised by the use of the objects (making heat exchangers B21D53/02) · CPC title

• B62D25/145 Primary

  having a crossbeam incorporated therein · CPC title

• B62D29/008

  predominantly of light alloys, e.g. extruded · CPC title

• F16L13/14

  made by plastically deforming the material of the pipe, e.g. by flanging, rolling · CPC title