OPTIMIZED CONNECTION STRUCTURE FOR METAL PIPE FITTING AND IMPLEMENTING METHOD THEREOF

Abstract

An optimized connection structure includes: pipe fittings (1) which is provided with radial through holes (13) about the periphery of the connecting part, multifunctional plugs (2, 20) which include: a plugging body (21) at the tail end, a groove (23) in the middle, and a large and a small positioning steps (22, 24) arranged in the inner holes of the tail ends of the pipe fittings (1), and a connecting member (3) which may be of a cast/forged composite structure, wherein an inner layer and an outer layer of metal rings (42, 41) and a plurality of radial and axial metal posts (43, 44) connecting the pipe fittings (1).

Claims

1. An optimized connection structure of metal tubes wherein the structure comprising: tubes, a multi-functional insert positioned in the inner end of a tube and a tube connector, in which one of the tubes contains radical through holes around the joint part and the center lines of the through holes are parallel to the tube's transverse section; the said multi-functional insert comprising: a block positioned at the end, a groove or a through hole in the middle and small and big shoulders at the top, wherein the big shoulder comprising: an axial hole or a through channel located at the external surface which connects the said groove or through hole, and a circular surface intersects with the inner side of the tube connector; the tube connector comprising: an inner metal ring, an outer metal ring, and several radical and axial metal bars connecting the rings which cover the tubes and the multi-functional insert and formed into a single, three dimensional structure with high toughness and strength during the forging process.

2. The optimized connection structure as claimed in claim 1, wherein the tube is selected from a group consisting of a top tube, a down tube, a seat tube, a seat stay, a chain stay and a front tube of bicycle frame, and a front fork of bicycle; the tube connector is positioned at the end of the connection part of the seat tube which connects the top tube and the two seat stays with the seat tube, and the connection part comprising: an inner hole and a through hole, which are locally counterbored along axial direction and diameter direction in order to fit the top tube and the seat stays during the seat tube forming process.

3. The optimized connection structure as claimed in claim 2, wherein the said multi-functional insert is selected from a group consisting of a two-port insert for top tube, a two-port insert for down tube, an insert for the seat tube, an insert for the seat stay, an insert for the chain stay, a double-insert for a dropout, a double-insert for a fork crown or an insert for a front dropout, and the multi-functional insert is a shape of circular, flat or irregular structure, wherein the small shoulder at the top and the block positioned at the end of the insert are of the same transverse shape and dimension, which could sliding fit within the inner side of the said tube, and the insert is a shape of flat structure, and the radical section thickness of the middle and top of the insert are less than that of the block at the insert end.

4. The optimized connection structure as claimed in claim 3, wherein the double-insert for the dropout is of an integrated structure with the insert being of circular or flat.

5. The optimized connection structure as claimed in claim 3, wherein the double-insert for the fork crown is of an integrated structure with the insert being of circular, flat or irregular, and a circular groove is positioned on the double-insert to fix the stem, and a through hole is positioned on the double-insert connecting the insert groove of stem and the crown lug.

6. The optimized connection structure as claimed in claim 2, the tube is selected from a group consisting of a head tube, a seat tube lug, a bottom bracket, a dropout lug, a front dropout lug and a crown lug; and the tube connector is formed by die forging and die casting, and the tubes and the multi-functional insert inside tubes, as inlaid parts, help secure and form connection parts to achieve connection with high strength by being pre-positioned in corresponding location in the forging and casting die.

7. The optimized connection structure as claimed in claim 6, the seat tube, the seat stay, the chain stay and the head tube connects the top tube and the down tube, the seat tube lug connecting the seat tube, the top tube and the seat stay, a bottom bracket connecting the seat tube, the down tube and the chain stay, the double-insert for dropout connecting the seat stay and the chain stay and the dropout connector, and the head tube, the seat tube lug, the bracket, the dropout lug and the double-insert for dropout are made of aluminum, and the top tube, the down tube, the seat tube, wherein the seat stay and the chain stay are made of steel.

8. The optimized connection structure as claimed in claim 7, wherein the head tube, the seat tube lug, the bracket and the dropout lug are made of magnesium while the top tube, the down tube, the seat tube, the seat stay, the chain stay and the double-insert for dropout are made of titanium, or the said head tube, the said seat tube lug; the bracket and the dropout lug are made of aluminum while the top tube, the down tube, the seat tube, the seat stay, the chain stay and the double-insert for dropout are made of titanium; or the head tube, the seat tube lug, the bracket, the double-insert for dropout, the dropout lug, the seat tube, the seat stay and the chain stay are made of magnesium while the top tube and the down tube are made of titanium.

9. The optimized connection structure as claimed in claim 2, the tube is selected from a group consisting of a fork stem, a front fork, an insert for front dropout, a crown lug connecting the stem and the front fork, a front dropout lug and a double-insert for crown connecting the front fork and an insert for front dropout; the double-insert for crown, the crown lug, the front dropout lug, the insert for front dropout are made of aluminum while the front fork and the stem are made of steel.

10. The optimized connection structure as claimed in claim 9, wherein the double-insert for crown, the crown lug, the front dropout lug, the insert for front dropout are made of aluminum while the front fork and the front stem are made of steel; or the double-insert for crown, the crown lug, the front dropout lug and the insert for front dropout are made of magnesium while the front fork and the front stem are made of titanium; or the double-insert for crown, the crown lug, the front dropout lug and the double-insert for front dropout are made of aluminum while the from fork and the front stem are made of titanium.

11. An optimized method of connecting metal tube wherein comprising: 1) machining an end face, through a hole or through a groove of metal or nonmetal tubes; 2) CNC machining a multi-functional insert; 3) chamfering, chip removing, dressing and drying tubes and the multi-functional insert, and performing micro-arc oxidation surface insulation surface when two different metal materials are connected; 4) stuffing the multi-functional insert that matches with the tube into joint end of the tube; 5) putting one or multiple tubes stuffed with multi-functional insert on the corresponding location of bottom die in the casting and forging combo-machine, securing together and closing the molds together by coordinating the PLC controlling, holding temperature of stock oven and mold heating and cooling system, then injecting molding filling with liquid lamellar flowing into the mold to fill the cavity inside the connector, the tubes and the multi-functional insert, and the combo-machine automatically controlled by PLC performing press forging which and keeps the force till it finally forms the connection parts after the temperature of the metal is cooled to semi-solid temperature, when one connection part forms an inner metal ring and an outer metal ring which are connected by numerous small radical or axial metal bars, and the rings and bars together with the forged and casted tubes and the multi-functional insert are finally forged and formed into one single, three dimensional structures with high toughness and strength.

12. A method for using the optimized connection structure of metal tube fitting claimed in claim 1 wherein connecting frame and front fork of bicycles, electric bikes with or without pedals, electric or pneumatic motorcycles and electric cars.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1 shows a typical casting and forging compound connection of a metal tube.

[0050] FIG. 2 shows a casting and forging compound connection of each part of a bicycle frame.

[0051] FIG. 3 shows the structure of a T type connection insert for circular tube in a bicycle frame or a front fork of this invention.

[0052] FIG. 4 shows the structure of an angle connection insert for circular tube in a bicycle frame of this invention.

[0053] FIG. 5 shows the structure of an angle connection insert for a flat tube in a bicycle frame of this invention.

[0054] FIG. 6 shows a connection structure for a double insert for dropouts in a bicycle of this invention.

[0055] FIG. 7 shows a casting and forging compound connection of each part of a bicycle front fork of this invention.

[0056] FIG. 8 shows the structure of a circular double insert for front fork crown in a bicycle of this invention.

[0057] FIG. 9 shows the structure of a flat double insert for front fork crown in a bicycle of this invention.

[0058] Among the above drawings: 1. metal tube, 2. multi-functional insert, 3. connector, 10. top tube, 11. inner hole of tube, 12. transverse section of tube, 13. radical through hole of tube, 14. down tube, 15. seat tube, 16. seat stays, 17. chain stays, 18. counterbored outer circle of seat tube, 19. radical through hole of seat tube, 20. T shape insert for circular tube, 21. block, 22. small shoulder for positioning, 23. ring groove for circular insert, 24. big shoulder for positioning, 25. axial through hole for insert, 26. intersecting circular surface, 27. lightening hole in insert, 28. circular angle insert, 29. flat angle insert, 30. block thickness of flat insert, 31. connection part thickness of flat insert, 32. connecting through hole of flat insert, 34. double insert for dropouts, 35. positioning groove in seat tube, 36. connected through hole in double insert, 37. circular double insert for crown, 38. flat double insert for crown, 39. insert for front dropout, 40. head tube, 41. outer ring, 42. inner ring, 43. radical connecting bar, 44. axial connecting bar, 45. external surface of connecting convex, 46. inner hole of head tube, 48. dropout lug, 49. bracket, 50. seat tube lug, 51. through hole fitting top tube, 52. through hole fitting seat stays, 58. crown lug, 59. front dropout lug, 60. front stem, 61. front fork, 62. radial through hole in front fork.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] The embodiments are described in more details below in order to explain this invention with the solution as premise. This invention is not to be limited in scope by the embodiments disclosed herein, and any that are functionally equivalent are within the scope of the invention.

The First Embodiment

[0060] Referring to FIG. 2, FIG. 3 and FIG. 4, the first embodiment is composed of connection with high toughness and strength among frame head tube 40, top tube 10 and down tube 14 as well as the tube material combination:

[0061] 1.1) Top tub 10 and down tube 14 are made of Ti3Al2.5V titanium seamless circular tube with wall thickness as 0.8 mm, inner hole diameter as 30.0 mm; 6 through holes around connection part of top tube 10 and down tube 14 are formed using mechanical or laser with 0=7.0 mm; head tube 40 is formed by casting and forging combo-machine with AZ80A-T4/T6 magnesium ingot while insert 20 and 28 are formed by lathe with AZ80A-T4/T6 magnesium bar.

[0062] 1.2) Chamfering, chip removing, dressing and drying the tubes and t insert;

[0063] 1.3) Performing micro-arc oxidation insulation on insert surface.

[0064] 1.4) Stuffing insert 20 and insert 28 into joint end of the top tube 10 and down tube 14.

[0065] 1.5) Putting top tube 10 and down tube 14 on the corresponding location of bottom die of head tube 40 in the casting and forging combo-machine, keeping temperature of the casting and forging mold at 200230 C., securing together and closing the molds together by coordinating the PLC controlling, then injecting molten magnesium keeping at 680730 C. through channel into the mold barrel of head tube 40 to perform molding filling with liquid lamellar flowing with the cavity in head tube 40: the molten magnesium flow radical through hole 13 of top tube 10 and down tube 14 and axial through hole 25 of insert and enter the ring groove 23 in insert and fill all the cavities; after a while when molten magnesium temperature is cooled down to 570585 C., the combo-machine automatically controlled by PLC performs press forging on head tube 40 and keeps specific press as 6085 MPa till it finally forms the connection parts. Now head tube 40 forms an inner magnesium ring 42 and an outer ring 41 which are connected by a radical magnesium bar 43 and an axial magnesium bar 44. The rings together with connection part connecting insert 20, top tube 10 and down tube 14 are finally forged and formed into one single, three dimensional structures with high toughness and strength.

The Second Embodiment

[0066] Referring to FIG. 2, FIG. 3 and FIG. 5, the second embodiment is composed of connection with high toughness and strength among frame seat tube 50, top tube 10 and seat stay 16 as well as the tube material combination.

[0067] 2.1) The inner hole at the end of seat tube 15 connection part is locally counterbored with axial length=50.0 mm, increased wall thickness=1.00 mm and increased radical diameter=8.0 mm. The through holes 51 and 52 fitting top tube 10 and seat stay 16 respectively are formed in the intermediate connection part of top tube 10 and seat stay 16. The width of seat stay 16 inner hole is 12.1 mm. The thickness 30 of block at end of the flat angle insert 29 is 12.0 mm. The clearance when sliding fit the seat stay and the angle insert is 0.1 mm while the thickness at middle and top is 7.0 mm. Except for top tube 10 made of Ti3AL2.5V seamless titanium tube, seat tube 15, seat stay 16 and all the inserts are made of 7050-T4/T6 titanium seamless tube and bar.

[0068] 2.2) Chamfering, chip removing, dressing and drying the tubes and t insert.

[0069] 2.3) Performing micro-arc oxidation insulation on surface of seat tube 15, two seat stays and inserts.

[0070] 2.4) Stuffing insert 20 and two flat inserts 29 into inner hole of joint end of the top tube 10 and seat tube 16.

[0071] 2.5) Putting the counterbored seat tube 15, top tube 10 stuffed with circular T shape insert 20 and seat stay 16 stuffed with flat angle insert 29 on the corresponding location of bottom die of seat tube 50 respectively in the casting and forging combo-machine, keeping temperature of the casting and forging mold at 200250 C., securing together and closing the molds together by coordinating the PLC controlling, then injecting molten aluminum keeping at 690720 C. through channel into the mold barrel of seat tube 50 to perform molding filling with liquid lamellar flowing with the cavity in seat tube 50: the molten aluminum flow radical through hole 13 of top tube 10 and seat stay 16 and axial through holes 25 and 23 of circular T shape insert 20 and flat angle insert 29 and fill all the cavities at left and right side of seat tube; after a while when molten aluminum temperature is cooled down to 580595 C., the combo-machine automatically controlled by PLC performs press forging on seat tube 50 and keeps specific press as 85110 MPa till it finally forms the connection parts. Now seat tube 50 forms an inner aluminum ring 42 and an outer ring 41 which are connected by a radical aluminum bar 43 and an axial aluminum bar 44. The rings together with connection part connecting top tube 10, top tube insert 20, two seat stays 16 and two flat angle inserts 29 are finally forged and formed into one single, three dimensional structures with high toughness and strength.

The Third Embodiment

[0072] Referring to FIG. 27 and FIG. 9, the third embodiment is composed of connection with high toughness and strength among crown lug 58, front stem 60 and two seat stays 62 at right and left side as well as the tube material combination.

[0073] 3.1) Two seat stays are made of Ti3AL2.5V seamless titanium tube, stem 60, insert 20, double insert for crown 38 and crown lug 58 are made of 7050-T4/T6 titanium seamless tube, bar and ingot.

[0074] 3.2) Chamfering, chip removing, dressing and drying the tubes and t insert.

[0075] 3.3) Performing micro-arc oxidation insulation on surface of insert and tube.

[0076] 3.4) Stuffing insert 20 into inner hole of joint end of the stem 60 then putting it into positioning groove in seat tube 35 of double insert for crown 38, aligning axial through 25 in the insert with through hole 36 in double insert for crown 38, spot welding symmetrically at joint part between insert 20 and double insert for crown 38 for following connection.

[0077] 3.5) Stuffing the left and right blocks, which are spot welded on stem 60 and double insert for crown 38, into the two front forks at right and left side, which are connected with dropout insert; putting this part on the corresponding location of bottom die of crown lug 58 in the casting and forging combo-machine, keeping temperature of the casting and forging mold at 200250 C., securing together and closing the molds together by coordinating the PLC controlling, then injecting molten aluminum keeping at 690720 C. through channel into the mold barrel of crown lug 58 to perform molding filling with liquid lamellar flowing with the cavity in crown lug 58: the molten aluminum flows the radical through hole 13 in stem 60, the axial through hole 25 in insert 20, the radical through hole 62 in the left and right front forks 61, and horizontal through hole 32 in double insert for crown 38 and fill all the cavities inside crown lug 58; after a while when molten aluminum temperature is cooled down to 580595 C., the combo-machine automatically controlled by PLC performs press forging on the crown lug 58 and keeps specific press as 85110 MPa till it finally forms the connection parts. Now the crown lug 58 forms an inner aluminum ring 42 and an outer ring 41 which are connected by a radical aluminum bar 43 and an axial aluminum bar 44. The rings together with connection part connecting stem 60, seat tube insert 20, two seat stays 61 and double insert for crown 58 are finally forged and formed into one single, three dimensional structures with high toughness and strength.