Joint unit and method for assembling joint unit

Patent metadata

Field	Value
Publication number	US-12055243-B2
Application number	US-202318178704-A
Country	US
Kind code	B2
Filing date	Mar 6, 2023
Priority date	Mar 7, 2022
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

Provided is joint unit having a resin tube, a joint structure, and a nut, the joint structure has a guide part that guides the outer circumferential face of the resin tube, a protrusion that forms an insertion groove between the guide part and the protrusion, and a fixing part that fixes the resin tube inserted in the insertion groove, the tip of the protrusion is located closer to a main body than the tip of the guide part, the nut has a recessed part having an inner diameter greater than a first outer diameter of the guide part and smaller than a second outer diameter of the fixing part, and the tip of the fixing part in contact with the recessed part bites into the outer circumferential face of the resin tube in a state where the nut is fastened to the joint structure.

First claim

What is claimed is:

1. A joint unit comprising:
a resin tube in which a liquid transferring channel extending along an axis is formed and whose cross section orthogonal to the axis is circular;
a joint structure formed in a shaft shape along the axis, having an external thread in an outer circumferential face of the joint structure, and configured to be attached to an end of the resin tube; and
a nut formed in a cylindrical shape along the axis and having an internal thread formed in an inner circumferential face of the nut, the internal thread being configured to be engaged with the external thread,
wherein the joint structure comprises
a main body,
at least one guide part formed in a part in a circumferential direction about the axis so as to protrude along the axis from the main body and configured to guide an outer circumferential face of the resin tube,
a protrusion formed in a shaft shape so as to protrude along the axis from the main body and forming an insertion groove between the guide part and the protrusion, the resin tube being inserted in the insertion groove, and
at least one fixing part formed in a part in the circumferential direction so as to protrude along the axis from the main body and configured to fix the resin tube inserted in the insertion groove,
wherein a coupling channel extending along the axis and configured to couple the liquid transferring channel and another channel is formed in the main body and the protrusion,
wherein a tip of the protrusion is located closer to the main body than a tip of the guide part,
wherein the nut has a recessed part having an inner diameter that is larger than a first outer diameter of the guide part and smaller than a second outer diameter of the fixing part, and
wherein a tip of the fixing part in contact with the recessed part bites into the outer circumferential face of the resin tube in a state where the nut is fastened to the joint structure.

2. The joint unit according to claim 1 ,
wherein the joint structure has a plurality of guide parts arranged spaced apart by intervals in the circumferential direction and a plurality of fixing parts arranged spaced apart by intervals in the circumferential direction, and
wherein the fixing parts are arranged between a pair of the guide parts arranged adjacent to each other.

3. The joint unit according to claim 1 , wherein the recessed part has a bottom against which the tip of the guide part is abutted.

4. The joint unit according to claim 1 , wherein the tip of the fixing part is located closer to the main body than the tip of the protrusion.

5. The joint unit according to claim 1 , wherein a biting part protruding toward the protrusion in a radial direction orthogonal to the axis and configured to bite into the outer circumferential face of the resin tube is formed at the tip of the fixing part.

6. The joint unit according to claim 1 , wherein a length of the protrusion along the axis is three or more times an outer diameter of the protrusion.

7. The joint unit according to claim 1 , wherein a length from the tip of the protrusion to the tip of the guide part is 0.2 or more times an inner diameter of the guide part.

8. The joint unit according to claim 1 , wherein an outer diameter of the resin tube is 3 or more times and 15 or less times an inner diameter of the resin tube.

9. The joint unit according to claim 8 , wherein the resin tube has an inner diameter of 0.1 mm or greater and 1.0 mm or less.

10. A method for assembling a joint unit, wherein the joint unit comprises
a resin tube in which a liquid transferring channel extending along an axis is formed and whose cross section orthogonal to the axis is circular,
a joint structure formed in a shaft shape along the axis, having an external thread in an outer circumferential face of the joint structure, and configured to be attached to an end of the resin tube, and
a nut formed in a cylindrical shape along the axis and having an internal thread formed in an inner circumferential face of the nut, the internal thread being configured to be engaged with the external thread,
wherein the joint structure comprises
a main body,
a guide part formed so as to protrude along the axis from the main body and configured to guide an outer circumferential face of the resin tube,
a protrusion formed in a shaft shape so as to protrude along the axis from the main body and forming an insertion groove between the guide part and the protrusion, the resin tube being inserted in the insertion groove, and
a fixing part formed so as to protrude along the axis from the main body and configured to fix the resin tube inserted in the insertion groove,
wherein a coupling channel extending along the axis and configured to couple the liquid transferring channel and another channel is formed in the main body and the protrusion,
wherein a tip of the protrusion is located closer to the main body than a tip of the guide part, and
wherein the nut has a recessed part having an inner diameter that is larger than a first outer diameter of the guide part and smaller than a second outer diameter of the fixing part,
the method comprising:
an insertion step of guiding the outer circumferential face of the resin tube by the guide part and inserting the protrusion in the liquid transferring channel; and
a fixing step of fastening the nut to the joint structure to cause the fixing part to come into contact with the recessed part and cause the tip of the fixing part to bite into the outer circumferential face of the resin tube.

Assignees

• Surpass Ind Co Ltd

Inventors

• Imai Hiroshi
• Hasunuma Masahiro

Classifications

• F16L25/14

  Joints for pipes of different diameters or cross-section · CPC title

• F16L25/0018

  Abutment joints · CPC title

• F16L21/06

  with a divided sleeve or ring clamping around the pipe ends (flanged joints F16L23/00; couplings of the quick-acting type F16L37/00) · CPC title

• F16L33/035

  fixed by means of teeth or hooks · CPC title

• F16L19/14

  the rings being integral with one of the connecting parts · CPC title