PRODUCTION METHOD OF TUBE-GRASPING BODY FOR GRASPING AN INSERT TUBE IN A HEAT EXCHANGER, AND PRODUCTION METHOD OF HEAT EXCHANGER USING APPARATUS UTILIZING SUCH TUBE-GRASPING BODY, AND AIR-CONDITIONER AND/OR ITS OUTDOOR UNIT WITH A HEAT EXCHANGER PRODUCED BY SUCH METHOD AND/OR APPARATUS

摘要

PRODUCTION METHOD OF TUBE-GRASPING BODY FOR GRASPING AN INSERT TUBE IN A HEAT EXCHANGER, AND PRODUCTION METHOD OF HEAT EXCHANGER USING APPARATUS UTILIZING SUCH TUBE-GRASPING BODY, AND AIR-CONDITIONER AND/OR ITS OUTDOOR UNIT WITH A HEAT EXCHANGER PRODUCED BY SUCH METHOD AND/OR APPARATUS The current 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 said tube-grasping body enables to enlarge and connect an insert tube to a heat radiating fin for producing a heat exchanger, still keeping the total length of insert tubes at an almost same level even after the enlargement; and said tube-grasping body is connected at its exterior to the guide-pipe. For example, the current invention can be used for producing any of following heat exchangers: a downsized heat exchanger where the gap (pitch) between each of the tube-grasping bodies is minimized, still avoiding contact with neighboring guide-pipes by allocating a tube-grasping body which is connected at its exterior to the guide-pipe, to each of straight tubes or hairpin tubes; and a heat exchanger where the gap between various types of insert tubes with different diameters and/or the gap between insert tubes is significantly reduced, for any of the following example cases: the case where the gap between straight tubes or hairpin tubes inserted into a heat radiating fin is reduced, in a heat exchanger downsized for savings in energy or cost, and/or the case where said gap between tubes being inserted in a zigzag pattern into a heat radiating fin is reduced, and/or the case where said gap is reduced, due to insertion of tubes in multiple columns such as columns of 3, 4, or etc. This can be connected externally to the tube-enlarging mandrel (2) from one end of the tube-grasping body (3) having a total length of the predetermined order positioned at the other end of the opening (7b) of the tube (7), and a tube-grasping body (3) at one end near the inner tube-grasping body (3), which is cut by cutting with the prescribed depth inside the said tube-grasping body (3) at one end, forming a swelling part (3z) that bulges to the axial direction of the tube-grasping body (3) to form a smaller inner diameter. After the site swelling part (3z), in order to form a tube-contacting part (3f) with a plurality of tube-contacting parts (3f) having bumps (3e) that can freely compress and expand radially in the longitudinal direction of the tube (7) tube-grasping body (3), multiple slits (3a) of prescribed length and width (3u) along the longitudinal direction of the tube-grasping body (3), and from one end to the other end of the tube-grasping body (3), are formed in the axial direction of the tube-grasping body (3) by dividing the number of slits (3a) and swelling parts (3z) by the multiple slits (3a) of the formed tube-contacting part (3f). A characteristic of this method is that each of the slits (3a), at a prescribed point, in the direction of the opening (7b) of the tube (7), spreads so as to have an expanded width (3x) which is gradually curved larger the prescribed width (3u), thereby providing the tube-contacting part (3f) on the exterior surface. Moreover, the degree of inclination of the slope (3b) in a direction that extends toward the opening (7b) of the tube (7), from the formation process of the predetermined position on the tube-contacting part (3f) that is greater than the degree of inclination when the slits (3a) are formed, the tube-grasping body (3) having a plurality of tube-contacting parts (3f) with bumps (3e) that protrude into the axial direction of the tube-grasping body (3) can be produced.