CN210435109U

CN210435109U - Pipe bending die and pipe bending assembly of thin-wall round pipe

Info

Publication number: CN210435109U
Application number: CN201920882704.4U
Authority: CN
Inventors: 何正林; 倪雪辉; 胡涛; 麦佩龙; 黄起建; 陈龙龙; 王琳; 张行; 宋威
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2020-05-01
Anticipated expiration: 2029-06-12

Abstract

The utility model provides a pipe bending mould and return bend subassembly of thin-walled circular tube, this pipe bending mould is including the portion of bending and the extension that link to each other, the portion of bending is located the tip of extension, the first surface of extension is provided with first recess, the second surface of extension is provided with the second recess, be provided with the third recess in the portion of bending, the both ends of third recess communicate with first recess and second recess respectively, the cross section of third recess is smooth curve structure, smooth curve structure is including consecutive first oval arc section, arc section and the oval arc section of second, the arc section is located the tank bottom of third recess, first arc section and second arc section are located the outside of arc section place circle. The utility model discloses a third recess that the bending die will be used for buckling the thin-walled pipe sets up to complicated curve structure, has increased the cross-sectional area of third recess effectively, has improved the inboard metal volume that flows to the outside along circumference of thin-walled pipe, can effectively restrain the problem that the inner wall corrugates because of the inner wall bodiness appears.

Description

Pipe bending die and pipe bending assembly of thin-wall round pipe

Technical Field

The utility model relates to a return bend field specifically is a pipe bending mould and return bend subassembly that relates to a thin wall pipe.

Background

The thin-wall round tube (the wall thickness is 0.1mm to 0.5mm) meets the requirements of light weight, strengthening and toughening and low energy consumption of products, and is widely applied to the industries of household appliances, aerospace, automobiles and the like. For example, the serpentine bends in the condenser and evaporator are formed by bending thin-walled round tubes through a bending die.

Structure of a prior art bending mould referring to fig. 1, the prior art bending mould comprises a bending part 100 and an extension part 200 connected with each other, the bending part 100 is located at an end of the extension part 200, an upper surface of the extension part 200 is provided with a first groove 201, and a lower surface of the extension part 200 is provided with a second groove (not visible in fig. 1). A third groove 101 is formed in the bending portion 100, and two ends of the third groove 101 are respectively communicated with the first groove 201 and the second groove. Referring to fig. 2 and 3, fig. 2 is a front view of a conventional pipe bending mold, fig. 3 is a sectional view taken in a direction a-a of fig. 2, a cross section of the third groove 101 is semicircular, and cross sections of the first groove 201 and the second groove are semicircular as same as a cross section of the third groove 101. The strip-shaped thin-walled circular tube is bent along the third groove 101 of the bending part 100 to form a bent tube, the metal flowing direction of the thin-walled circular tube in the tube bending process refers to fig. 4 and 5, fig. 4 is a schematic view of the axial flowing of the metal of the thin-walled circular tube in the tube bending process, fig. 5 is a schematic view of the circumferential flowing of the metal of the thin-walled circular tube in the tube bending process, in the axial direction, the outer side material of the thin-walled circular tube is subjected to tensile stress to enable the metal to flow towards two; the inner side material of the thin-wall circular tube is stressed by pressure, so that the metal flows to the center, and the inner wall is thickened. In the circumferential direction, the inner side material of the thin-wall circular tube flows outwards, and the circumferential flowing result has the tendency of simulating the thickening of the inner wall and the thinning of the outer wall. Because the metal axial flow of the thin-wall circular tube is greater than the circumferential flow, the problem of wrinkling of the inner wall is easy to occur in the bending forming process.

Disclosure of Invention

The utility model discloses a first purpose provides a bending die of thin wall pipe.

A second object of the present invention is to provide a pipe bending assembly.

In order to realize above-mentioned first purpose, the utility model provides a bending die is including the portion of bending and the extension that link to each other, the portion of bending is located the tip of extension, the first surface of extension is provided with first recess, the second surface of extension is provided with the second recess, be provided with the third recess in the portion of bending, the both ends of third recess communicate with first recess and second recess respectively, first surface sets up with the second surface relatively, wherein, the cross section of third recess is smooth curve structure, smooth curve structure is including the first oval arc section that links to each other in proper order, arc section and the oval arc section of second, the arc section is located the tank bottom of third recess, first arc section and second arc section are located the outside of arc section place circle.

According to the scheme, the third groove for bending the thin-wall circular tube is set to be of a complex curve structure, the cross sectional area of the third groove is effectively increased, the metal amount flowing outwards along the circumferential direction on the inner side of the thin-wall circular tube is increased, and the problem that the inner wall is wrinkled due to thickening of the inner wall can be effectively solved.

The surface of the bending part is also provided with a thickened part, the thickened part is provided with an opening, and the opening is communicated with the third groove.

Therefore, the deformation of the thin-wall circular tube along the radial direction in the pipe bending process can be reduced by limiting the thickened part on the thin-wall circular tube.

In a further aspect, the size of the opening is gradually reduced from outside to inside. The advantage of setting up like this is convenient for take out the thin wall pipe behind the return bend.

The further proposal is that the thickness of the thickened part is h, the radius of the circle where the arc section is located is r, and h is more than 0 and less than r/4. Experiments show that when r and h satisfy the relational expression, the radial size of the thin-wall circular tube can be kept, and the material of a pipe bending die can be reduced.

Still further, the surface of the third groove is coated with a lubricating coating.

Therefore, the friction force between the thin-wall circular tube and the tube bending die can be reduced by coating the lubricating coating, the forming difficulty can be reduced, and the thin-wall circular tube can be conveniently taken out after the tube is bent.

In order to realize above-mentioned second purpose, the utility model provides a return bend subassembly, including clamp mould, return bend mould, core bar and die-supporting, the return bend mould adopts above-mentioned return bend mould, presss from both sides the mould butt on the thin wall pipe outside first recess, and the die-supporting butt is on the thin wall pipe outside the second recess, and in the core bar inserted the thin wall pipe, the one end of core bar extended to the juncture of second recess and third recess.

Drawings

Fig. 1 is a structural view of a conventional bending die.

Fig. 2 is a front view of a conventional bending die.

Fig. 3 is a sectional view taken in the direction of a-a in fig. 2.

FIG. 4 is a schematic axial flow diagram of metal from a thin-walled round tube during a pipe bending process.

FIG. 5 is a schematic view of the circumferential flow of metal from a thin-walled round tube during a pipe bending process.

Fig. 6 is a structural diagram of an embodiment of the bending die of the present invention.

Fig. 7 is a front view of the bending die of the present invention.

Fig. 8 is a sectional view taken in the direction B-B in fig. 7.

Fig. 9 is an enlarged view of a structure of a portion C in fig. 8.

FIG. 10 is a cross-sectional view of the elbow assembly and thin-walled round tube during elbow forming.

The present invention will be further explained with reference to the drawings and examples.

Detailed Description

Bending die embodiment

Referring to fig. 6 to 9, the bending die 1 of the present embodiment includes a bending portion 10 and an extension portion 20 connected to each other, and the bending portion 10 and the extension portion 20 are integrally formed. The bending part 10 is located at the end of the extension part 20, a first surface (the upper surface shown in fig. 6) of the extension part 20 is provided with a first groove 21, a second surface (the lower surface shown in fig. 6) of the extension part 20 is provided with a second groove (not visible in fig. 6), and the first surface and the second surface are arranged oppositely; a third groove 11 is formed in the bending portion 10, and two ends of the third groove 11 are respectively communicated with the first groove 21 and the second groove. The surface of the bend 10 is also provided with a thickening 12.

The cross section of the third groove 11 is a smooth curve structure, the smooth curve structure includes a first elliptical arc segment 110, an arc segment 111 and a second elliptical arc segment 112 which are connected in sequence, and the arc segment 111 is located at the bottom of the third groove 11. The circle of the circular arc segment 11 is a circle O1, and the first circular arc segment 110 and the second circular arc segment 112 are located outside the circle O1. The thickened portion 12 is provided with an opening 120, the opening 120 is communicated with the third groove 11, and the opening size of the opening 120 is gradually reduced from outside to inside, i.e. the side wall of the opening 120 is arranged as an inclined plane.

The thickness of the thickened portion 12 is h, and in the present invention, the thickness h of the thickened portion 12 is a vertical distance from the innermost side to the outermost side of the opening 120. The circle O1 has a radius r, and h and r satisfy the following relationship: h is more than 0 and less than r/4.

In the pipe bending process, in order to reduce the friction force between the thin-wall round pipe and the pipe bending die, the lubricating coating is coated on the surface of the third groove 11, so that the forming difficulty is reduced, and the thin-wall round pipe is convenient to take out after being bent.

Elbow assembly embodiments

Referring to fig. 10, fig. 10 is a cross-sectional view of a pipe bending assembly and a thin-walled circular pipe during pipe bending forming, wherein the pipe bending assembly comprises a clamp die 2, a pipe bending die 1, a core rod 3 and a support die 4. Referring to fig. 6 to 9, in the process of forming the bent pipe, one end of the thin-walled circular pipe 5 is located in the second groove 22, and the thin-walled circular pipe 5 is bent and formed along the third groove 11; after the pipe bending is carried out, the other end of the thin-wall circular pipe 5 is positioned in the first groove 21, the supporting die 4 abuts against the thin-wall circular pipe 5 outside the second groove 22, and the clamping die 2 abuts against the thin-wall circular pipe 5 outside the first groove 21. The core rod 3 is inserted into the thin-wall circular tube 5, and one end of the core rod 3 extends to the junction of the second groove 22 and the third groove 11.

Finally, it should be emphasized that the above-described embodiments are merely preferred examples of the present invention, and are not intended to limit the invention, as those skilled in the art will appreciate that various changes and modifications may be made, and any and all modifications, equivalents, and improvements made, while remaining within the spirit and principles of the present invention, are intended to be included within the scope of the present invention.

Claims

1. The pipe bending die for the thin-wall round pipe comprises a bending part and an extending part which are connected, wherein the bending part is positioned at the end part of the extending part, a first groove is formed in the first surface of the extending part, a second groove is formed in the second surface of the extending part, a third groove is formed in the bending part, two ends of the third groove are respectively communicated with the first groove and the second groove, and the first surface and the second surface are oppositely arranged;

the method is characterized in that:

the cross section of third recess is smooth curve structure, smooth curve structure includes consecutive first elliptical arc section, circular arc section and second elliptical arc section, the circular arc section is located the tank bottom of third recess, first elliptical arc section with the second elliptical arc section is located the outside of circular arc section place circle.

2. The bending die according to claim 1, wherein:

the surface of the bending portion is further provided with a thickened portion, an opening is formed in the thickened portion, and the opening is communicated with the third groove.

3. The bending die according to claim 2, wherein:

the opening size of the opening is gradually reduced from outside to inside.

4. The bending die according to claim 2, wherein:

the thickness of the thickened part is h, the radius of a circle where the circular arc section is located is r, and h is more than 0 and less than r/4.

5. The bending die according to any one of claims 1 to 4, wherein:

the surface of the third groove is coated with a lubricating coating.

6. The return bend subassembly is including pressing from both sides mould, return bend mould, core bar and die holder, its characterized in that:

the bending die adopts the bending die according to any one of claims 1 to 5, the clamping die abuts against the thin-walled circular tube outside the first groove, the supporting die abuts against the thin-walled circular tube outside the second groove, the core rod is inserted into the thin-walled circular tube, and one end of the core rod extends to the junction of the second groove and the third groove.