Manufacturing method for grip member for insertion tube in heat exchanger, manufacturing method for heat exchanger using said grip member, and air conditioner and/or outdoor unit having said heat exchanger

• US 9,656,355 B2
• Filed: 07/20/2012
• Issued: 05/23/2017
• Est. Priority Date: 07/20/2011
• Status: Active Grant

• Current Assignee: Kyoshin Kogyo Co., Ltd. (Rhythm Co., Ltd.)
• Original Assignee: Kyoshin Kogyo Co., Ltd. (Rhythm Co., Ltd.)
• Inventors: Tokura, Kenji
• Primary Examiner(s): Afzali, Sarang
• Assistant Examiner(s): Hidalgo-Hernandez, Ruth G
• Application Number:
  US14/233,722
• Publication Number:
  US 20140124184A1
• Time in Patent Office: 1,768 Days
• CPC Class Codes: B21D 41/028 expandable mandrels
• CPC Class Codes: B21D 53/08 of both metal tubes and sheet metal connecting tubes in openings B21D39/06
• CPC Class Codes: B23P 15/26 heat exchangers or the like making heat exchangers by methods covered by other subclasses B21D53/02
• CPC Class Codes: F28D 1/0475 the conduits having a single U-bend
• CPC Class Codes: F28F 1/30 the means being attachable to the element F28F1/32 takes precedence
• CPC Class Codes: F28F 1/32 the means having portions engaging further tubular elements
• CPC Class Codes: F28F 2255/00 Heat exchanger elements made of materials having special features or resulting from particular manufacturing processes
• CPC Class Codes: Y10T 29/49378 Finned tube

Abstract

The invention provides a tube-grasping body for grasping an insert tube in a heat exchanger, and heat exchanger production methods and apparatuses utilizing the tube-grasping body, wherein the tube-grasping body enables enlarging and connecting an insert tube to a heat radiating fin for producing a heat exchanger, while still keeping the total length of insert tubes at an almost same level even after the enlargement; and the tube-grasping body is connected at its exterior to a guide-pipe.

Claims

1. A production method for a tube-grasping body (3) of a heat exchanger through pipe utilized by a heat exchanger production apparatus, which is also connectable at an exterior of a tube-enlarging mandrel (2), for moving back and forth, along said tube-enlarging mandrel (2) which is penetrable from an opening (7b) of a hairpin tube (7) inserted into a heat radiating fin (6) of the heat exchanger (5);

and is also equipped with a plurality of tube-contacting parts (3f), capable of radially expanding or axially compressing in a cross direction of a longitudinal length of said hairpin tube (7); and

is also equipped with slopes (3b) which are formed beforehand and has a predetermined slope, slanting gradually in a widening direction toward the opening (7b) of the hairpin tube, wherein each of the slopes (3b) is formed to a bigger slant by curve and spread a width of each of multiple slits (3a), and formed on an exterior surface of each of said tube-contacting parts (3f); and

which also radially expands or axially compresses each of said tube-contacting parts (3f), by a sliding means which moves back and forth in a longitudinal direction of the hairpin tube, along said slopes (3b) of the tube-contacting parts (3f), said production method comprising;

producing the tube-grasping body (3) having the plurality of tube-contacting parts (3f) with bumps (3e) that protrude into an axial direction of the tube-grasping body (3) which comprises;

a) cutting with a prescribed depth inside the tube-grasping body (3), which has a prescribed total length, at one end positioned at the opening (7b) of the hairpin tube (7) to an other end, forming a swelling part (3z) that bulges to the axial direction of the tube-grasping body (3) to form a smaller inner diameter;

b) after forming the swelling part (3z), forming the multiple slits (3a) of a prescribed width (3u) in the longitudinal direction with a prescribed length and width from one end of the tube-grasping body (3) to the other end of the tube- grasping body (3) in order to form the tube-contacting part (3f) that can freely compress and expand radially in the longitudinal direction of hairpin tube (7) of tube-grasping body (3) and therefore, through the multiple slits (3a), divide the swelling part (3z) by a number of the multiple slits (3a) and forming the plurality of tube-contacting parts (3f) having the bumps (3e) that protrude into the axial direction of the tube-grasping body (3); and

c) spreading the multiple slits (3a) from a prescribed point towards the direction of the opening (7b) of the hairpin tube (7) so as to have an expanded width (3x) gradually curved wider than the prescribed width (3u) to form a degree of inclination of each of the slopes (3b) provided on the exterior surface of each tube-contacting part (3f), which inclines in an expanding direction towards the opening (7b) of the hairpin tube (7), larger than a degree of inclination of each of the slopes (3b) when the slits (3a) were formed.

2. The production method for the tube-grasping body of the heat exchanger through pipe according to claim 1, wherein each of the slopes (3b), which inclines in the direction extending towards the opening (7b) of the hairpin tube (7), is formed by cutting or grinding the exterior of the tube-grasping body (3) before forming the multiple slits (3a) of the prescribed width (3u).

3. The production method for the tube-grasping body of the heat exchanger through pipe according to claim 1, wherein the step of spreading the multiple slits (3a) from the prescribed point towards the direction of the opening (7b) of the hairpin tube (7) so as to have an expanded width (3x) that is gradually curved wider than the prescribed width (3u) to form the degree of inclination of each of the slopes (3b) provided on the exterior surface of each tube-contacting part (3f), which inclines in the direction extending towards the opening (7b) of the hairpin tube (7), larger than the degree of inclination of slope (3b) when the multiple slits (3a) were formed, is performed by inserting a cone-liked jig or a cylindrical jig equipped with a plurality of acute convex-like bumps to be inserted in the longitudinal direction from one end of the tube-grasping body (3) to the other end into the multiple slits (3a) from the prescribed point towards the direction of the opening (7b) of the hairpin tube (7).

4. A production method for a tube-grasping body (3) of a heat exchanger through pipe utilized by a heat exchanger production apparatus, which is also connectable at an exterior of a tube-enlarging mandrel (2), for moving back and forth, along said tube-enlarging mandrel (2) which is penetrable from an opening (7b) of a tube (7) inserted into a heat radiating fin (6) of the heat exchanger (5);

and is also equipped with a plurality of tube-contacting parts (3f), capable of radially expanding or axially compressing in a cross direction of a longitudinal length of said tube (7); and

is also equipped with slopes (3b) which are formed beforehand and has a predetermined slope, slanting gradually in a widening direction toward the opening (7b) of the tube, wherein each of the slopes (3b) is formed to a bigger slant by curve and spread a width of each of multiple slits, and formed on an exterior surface of each of said tube-contacting parts (3f); and

which also radially expands or axially compresses each of said tube-contacting parts (3f), by a sliding means which moves back and forth in a longitudinal direction of the tube, along said slopes (3b) of the tube-contacting parts (3f), comprising;

producing the tube-grasping body (3) having the plurality of tube-contacting parts (3f) with bumps (3e) that protrude into an axial direction of the tube-grasping body (3) which comprises;

a) cutting with a prescribed depth inside the tube-grasping body (3), which has a prescribed total length, at one end positioned at the opening (7b) of the tube (7) to an other end, forming a swelling part (3z) that bulges to the axial direction of the tube-grasping body (3) to form a smaller inner diameter;

b) before and after forming the swelling part (3z), grinding or cutting to form a peripheral slope (3m) of an end-line (3o) of one end of tube-grasping body (3) that slopes in a direction extending towards the opening (7b) of the corresponding tube (7);

c) forming the multiple slits (3a) of a prescribed width (3u) in a longitudinal direction with a prescribed length and width from one end of the tube-grasping body (3) to the other end of the tube-grasping body (3) in order to form the tube-contacting part (3f) that can freely compress and expand radially in the longitudinal direction of tube (7) of tube-grasping body (3) and therefore, through the multiple slits (3a), divide the swelling part (3z) by a number of the multiple slits (3a) and forming the plurality of tube-contacting parts (3f) having the bumps (3e) that protrude into the axial direction of the tube-grasping body (3); and

d) spreading the multiple slits (3a) from a prescribed point towards the direction of the opening (7b) of the tube (7) so as to have an expanded width (3x) that is gradually curved wider than the prescribed width (3u) to form a degree of inclination of each of the slopes (3b) provided on the exterior surface of each tube-contacting part (3f), which inclines in an expanding direction towards the opening (7b) of the tube (7), larger than a degree of inclination of each of the slopes (3b) when the slits (3a) were formed.