Device and method for forming inside three-dimensional finned tube by multi-edge ploughing and extruding

Patent metadata

Field	Value
Publication number	US-10807145-B2
Application number	US-201816153777-A
Country	US
Kind code	B2
Filing date	Oct 7, 2018
Priority date	Nov 10, 2016
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

A device for forming inside three-dimensional finned tube by multi-edge ploughing and extruding, comprises a machine frame, a machine head, a supporting mechanism, an axial feeding mechanism and a cutter assembly for forming inside fins. The machine head, the supporting mechanism and the axial feeding mechanism are axially mounted on the machine frame in sequence. The cutter assembly for forming inside fins is mounted on the feeding mechanism. One end of a metal tube to be machined for forming inside three-dimensional fins is clamped on a chunk of a rotary main shaft of the machine head, and the other end thereof is placed on the supporting mechanism. The rotary main shaft of the machine head provides the rotation power for the metal tube, and the axial feeding mechanism drives the cutter assembly to move linearly along a coaxial line of the metal tube and the cutter assembly.

First claim

We claim:

1. A device for forming an inside three-dimensional finned tube by multi-edge ploughing and extruding, comprising: a machine frame ( 1 ), a machine head ( 3 ) capable of providing rotation power, a supporting mechanism ( 4 ), an axial feeding mechanism ( 5 ) and a cutter assembly for forming inside fins;
wherein the machine head ( 3 ), the supporting mechanism ( 4 ) and the axial feeding mechanism ( 5 ) are axially mounted on the machine frame ( 1 ) in sequence; the cutter assembly for forming inside fins is mounted on the axial feeding mechanism ( 5 ); one end of a metal tube ( 7 ) to be machined for forming inside three-dimensional fins is clamped on a chunk of a rotary main shaft of the machine head ( 3 ), and the other end thereof is placed on the supporting mechanism ( 4 ); the metal tube ( 7 ) is coaxial with the cutter assembly for forming inside fins; the rotary main shaft of the machine head ( 3 ) provides the rotation power for the metal tube ( 7 ); and the axial feeding mechanism ( 5 ) drives the cutter assembly for forming inside fins to move linearly along a coaxial line of the metal tube ( 7 ) and the cutter assembly for forming inside fins;
wherein the cutter assembly for forming inside fins comprises a multi-edge cutter ( 6 - 4 ), a handle ( 6 - 3 ) and a connecting rod ( 6 - 2 ); and the multi-edge cutter ( 6 - 4 ) is mounted on one end of the handle ( 6 - 3 ) and the other end of the handle ( 6 - 3 ) is inserted into a front end of the connecting rod ( 6 - 2 ), and a rear end of the connecting rod ( 6 - 2 ) is fixed to the feeding mechanism ( 5 );
wherein a convex bar ( 6 - 5 ) is defined on the handle ( 6 - 3 ); the front end of the connecting rod ( 6 - 2 ) is in a cylindrical structure with an annular permanent magnet ( 6 - 1 ) sleeved therein, and a slot ( 6 - 6 ) corresponding to the convex bar ( 6 - 5 ) is defined on the front end of the connecting rod ( 6 - 2 ); when the handle ( 6 - 3 ) is inserted into the connecting rod ( 6 - 2 ), the convex bar ( 6 - 5 ) and the slot ( 6 - 6 ) limit the handle ( 6 - 3 ) to move circumferentially relative to the connecting rod ( 6 - 2 ); under a magnetic force of the annular permanent magnet, the handle ( 6 - 3 ) is attracted to the connecting rod ( 6 - 2 ).

2. The device according to claim 1 , wherein all of edges ( 6 - 8 ) of the multi-edge cutter ( 6 - 4 ) are in the same conical structure with a taper degree of 10° ˜ 30°, and the edges ( 6 - 8 ) are symmetrically distributed around an annular base.

3. The device according to claim 2 , wherein an extracting mechanism ( 2 ) for extract the handle ( 6 - 3 ) is mounted at a left side of the machine head ( 3 ), and comprises a cylinder ( 2 - 2 ) and a pneumatic chuck ( 2 - 3 ) arranged at an end of a piston of the cylinder ( 2 - 2 ); and the piston of the cylinder ( 2 - 2 ) is retracted after the pneumatic chuck ( 2 - 3 ) clamps an end of the handle ( 6 - 3 ) so as to extract the handle ( 6 - 3 ) axially from the connecting rod ( 6 - 2 ).

4. The device according to claim 1 , wherein the supporting mechanism ( 4 ) includes a support ( 4 - 1 ) defined with a working position ( 4 - 4 ) for placing the metal tube ( 7 ); three clamping cylinders ( 4 - 2 ) are symmetrically distributed on the support ( 4 - 1 ); a claw ( 4 - 3 ) is mounted at an end of a piston of each clamping cylinder ( 4 - 2 ), and a rotatable roller ( 4 - 3 a ) is mounted at an end of each claw ( 4 - 3 ); rollers ( 4 - 3 a ) are symmetrically distributed around the working position ( 4 - 4 ); and when the metal tube ( 7 ) is placed into the working position ( 4 - 4 ), rollers ( 4 - 3 a ) are in rolling contact with a circumference of the metal tube ( 7 ), for providing support and positioning for the rotating metal tube ( 7 ).

5. The device according to claim 1 , wherein the axial feeding mechanism ( 5 ) is a lead screw feeding mechanism, which comprises a lead screw and a slider mounted on the lead screw; when the lead screw is rotated, the slider is driven to move axially; and the connecting rod ( 6 - 2 ) is fixed on the slider.

6. The device according to claim 1 , wherein the multi-edge cutter ( 6 - 4 ) is fixed on the front end of the connecting rod ( 6 - 2 ) by a nut.

7. A method for forming inside three-dimensional finned tube, realized by adopting the device according to claim 3 , and comprising following steps:
1) placing the metal tube ( 7 ) with an internal threaded structure into the working position ( 4 - 4 ) of the supporting mechanism ( 4 ) axially, wherein an end of the metal tube ( 7 ) is fixed on a chunk of a rotary main shaft of the machine head ( 3 ), and keeping the metal tube ( 7 ) being coaxial with the multi-edge cutter ( 6 - 4 );
2) driving the metal tube ( 7 ) to rotate by the rotary main shaft of the machine head ( 3 );
3) starting the axial feeding mechanism ( 5 ) to drive the multi-edge cutter ( 6 - 4 ) to move continuously and axially toward the metal tube ( 7 , wherein the edges ( 6 - 8 ) of the multi-edge cutter ( 6 - 4 ) cut a raised part of the internal threaded structure simultaneously to divide the raised part into two parts when the multi-edge cutter ( 6 - 4 ) enters the metal tube ( 7 ); an arc edge of the edge ( 6 - 8 ) ploughs to form a groove and a conical rear cutter surface extrudes the groove outwards simultaneously, for expanding the groove and forming a discontinuous inside three-dimensional fins higher than the raised part of the internal threaded structure; and
4) keeping the axial feeding mechanism ( 5 ) feeding until the discontinuous inside three-dimensional fins are formed in the entire side wall of the metal tube ( 7 );
after the discontinuous inside three-dimensional fins are formed in the entire side wall of the metal tube ( 7 ), extending the multi-edge cutter ( 6 - 4 ) out of an end of the metal tube ( 7 ); stopping the machine head ( 3 ) and the axial feeding mechanism ( 5 ); retracting the piston of the cylinder ( 2 - 2 ) after the pneumatic chuck ( 2 - 3 ) of the extracting mechanism ( 2 ) clamps an end of the handle ( 6 - 3 ) and extracting the handle ( 6 - 3 ) axially from the connecting rod ( 6 - 2 ); and moving the axial feeding mechanism ( 5 ) backward to an initial position.

Assignees

• Univ South China Tech

Inventors

• Wan Zhenping
• Huang Shufeng
• Zou Shuiping
• Lu Longsheng
• Tang Yong

Classifications

• B21D53/06 Primary

  of metal tubes · CPC title

• B21D53/085

  with fins places on zig-zag tubes or parallel tubes · CPC title

• B21C37/207

  with helical guides · CPC title

• F28F1/40

  the means being only inside the tubular element · CPC title

• F28F1/36

  the means being helically wound fins or wire spirals · CPC title