A push-bending die with adjustable pipe diameter and bending radius

Abstract

A push-bending die with adjustable pipe diameter and bending radius belongs to the technical field of metal pipe bending forming equipment and is used to bend pipes with different pipe diameters and bending radii. Its technical solution is as follows: the lower end of the guide block is connected to the upper bending die, and the center of the guide block has a guide hole along the length direction. The diameter of the guide hole matches the diameter of the bent pipe. The two side walls of the fixed block clamp and fasten the upper bending die to the lower bending die. The lower end face of the upper bending die and the upper end face of the lower bending die slide in the longitudinal direction through relative longitudinal sliding grooves and sliding flat keys respectively. The lower end face of the upper bending die and the upper end face of the lower bending die respectively have multiple groups of relative transverse adjustment grooves. Transverse adjustment grooves with different spacings are selected and fixed with adjustment flat keys. The present invention has a simple structure and is easy to use. It does not require the replacement of the bending die. The diameter and bending radius of the bent pipe can be adjusted. Metal pipes with different pipe diameters and bending radii can be bent, which reduces production costs and improves efficiency.

Description

Technical Field

[0001] The invention relates to a push-bending die with adjustable pipe diameter and bending radius, belonging to the technical field of metal pipe bending forming equipment. Background Art

[0002] Thin-walled metal bent tubes are widely used in all industrial sectors, including machinery, steel, chemicals, petroleum, mining, construction, transportation, electrical appliances, vehicles, and aerospace. The materials and geometries of bent tubes vary greatly depending on the specific product requirements, necessitating tailored design and manufacturing. To date, a variety of bending methods have been developed, including bending, roll bending, press bending, and push bending. These methods offer varying advantages, but typically, the same set of bending dies used in these methods can only produce tubes with a fixed diameter and bend radius. Changes in diameter or bend radius require replacement of the dies.

[0003] Chinese Patent No. ZL200710093018.0 discloses a bending die capable of bending pipes of varying outer diameters. By adjusting the shape of the bending die's grooves, the patent enables bending of pipes of varying outer diameters using a single die, significantly improving production efficiency and reducing die costs. However, the patent focuses on bending dies and is not applicable to other types of pipe bending dies. Furthermore, the bending radius of the die cannot be changed.

[0004] Free bending (also known as 3D roll bending, MOS bending, etc.), proposed by Japanese scholars, is a flexible tube bending process based on CNC technology [MURATA M, OHASHI N, SUZUKI H. New Flexible Penetration Bending of A Tube: 1st Report, A Study of MOS Bending Method[C]. Transactions of the Japan Society of Mechanical Engineers Series C, 1989, 55(517):2488-2492]. It can achieve complex tube bending with continuously varying bending radius in any direction in space. Three-axis, five-axis, and six-axis three-dimensional free bending equipment developed by the German company J.NEU has been successfully applied in the industrial field. However, these free bending equipment are not only complex and costly, but also require a set of molds that are limited to forming tubes of a specific diameter.

[0005] In summary, most of the existing pipe bending methods can only meet the requirements of bending pipes with a single pipe diameter and bending radius. The free bending equipment in the existing technology that can bend complex pipes with multiple continuously changing bending radii has a complex structure and high cost, and a set of molds can only form pipes of a specific diameter, with a long development cycle, high operating cost and low efficiency. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a push-bending die with adjustable pipe diameter and bending radius. This push-bending die can adjust the diameter and bending radius of the bent pipe, thereby achieving the purpose of being able to bend metal pipes with different pipe diameters and bending radii, greatly improving the application range of the pipe bending die, thereby reducing production costs and improving efficiency.

[0007] The technical solution to the above technical problems is:

[0008] The cam is a kind of push-bending die with adjustable pipe diameter and bending radius, which includes an upper bending die, a lower bending die, a guide block, a fixed block, a sliding flat key and an adjusting flat key. The upper bending die and the lower bending die are respectively the same square steel blocks, the lower plate surface of the upper bending die and the upper plate surface of the lower bending die are relatively stacked, the upper center of the upper bending die is provided with a square groove, the lower center of the upper bending die is provided with an upper die forming hole, the center of the square groove is provided with a circular hole connected with the upper die forming hole, the center of the lower bending die is provided with a lower die forming hole, the lower die forming hole of the lower bending die is relatively connected with the upper die forming hole of the upper bending die, the guide block is an upright rectangular steel block, the two ends of the guide block are squares matching the square groove of the upper bending die, the lower end of the guide block is embedded in the square groove of the upper bending die, the center of the guide block is provided with a guide hole along the length direction, the diameter of the guide hole matches the diameter of the bent pipe, the lower end of the guide hole is relatively connected with the upper end of the upper die forming hole, the fixed block is a U-shaped block, the fixed block The two fixing plates are respectively fixed to the top and bottom of the U-shaped member, and the fixing plates are respectively fixed to the top and bottom of the U-shaped member.

[0009] The above-mentioned push-bending die with adjustable pipe diameter and bending radius, the depth of the square groove of the upper bending die is 1 / 2 of the thickness of the upper bending die, the upper die forming hole at the lower part of the upper bending die is a conical hole, the annular circumferential surface of the conical hole has a circular arc protruding toward the central axis of the circular hole, the small diameter end of the conical hole is relatively connected to the central circular hole of the square groove, and the large diameter end of the conical hole is relatively connected to the upper end of the lower die forming hole of the lower bending die.

[0010] The above-mentioned push-bending mold with adjustable pipe diameter and bending radius, the lower mold forming hole of the lower bending mold is a vertical unequal diameter circular hole, the diameters of the two ends of the lower mold forming hole are larger than the middle diameter, and the circumference of the hole wall of the lower mold forming hole is a circular arc surface protruding toward the central axis of the lower mold forming hole.

[0011] The above-mentioned push-bending die with adjustable pipe diameter and bending radius, the U-shaped top surface of the fixed block is vertical, the U-shaped top surface of the fixed block is located on one side of the upper bending die and the lower bending die, the two side walls of the U-shape of the fixed block are respectively opposite to the upper end surface of the upper bending die and the lower end surface of the lower bending die, and there are two threaded holes on the side wall of the fixed block opposite to the upper end surface of the upper bending die, and the tightening screws are screwed into the threaded holes and tightly connected to the upper end surface of the upper bending die.

[0012] The above-mentioned push-bending mold with adjustable pipe diameter and bending radius, the two longitudinal sliding grooves on the lower end face of the upper bending mold and the two longitudinal sliding grooves on the upper end face of the lower bending mold are respectively located in the middle position of the two end edges of the upper bending mold and the two end edges of the lower bending mold, the length, width and depth of the two longitudinal sliding grooves on the lower end face of the upper bending mold are respectively the same as the length, width and depth of the two longitudinal sliding grooves on the upper end face of the lower bending mold, the upper half and lower half of the two sliding flat keys are respectively embedded in the relative longitudinal sliding grooves at both ends of the upper bending mold and the lower bending mold.

[0013] The above-mentioned push-bending mold with adjustable pipe diameter and bending radius, the multiple transverse adjustment grooves of the lower end face of the upper bending mold and the upper end face of the lower bending mold are respectively located in the middle position of the two end edges of the lower end face of the upper bending mold and the two end edges of the upper end face of the lower bending mold, the length, width and depth of the transverse adjustment groove of the lower end face of the upper bending mold are respectively the same as the length, width and depth of the transverse adjustment groove of the upper end face of the lower bending mold, the multiple transverse adjustment grooves of the lower end face of the upper bending mold are respectively combined with the multiple transverse adjustment grooves of the upper end face of the lower bending mold, the offset δ between the combined upper bending mold and the lower bending mold corresponds to the bending radius of the bent pipe, the two adjustment flat keys are respectively embedded in a group of transverse adjustment grooves combined with the lower end face of the upper bending mold and the upper end face of the lower bending mold, and the upper bending mold and the lower bending mold are positioned, and after positioning, the upper mold forming hole of the upper bending mold and the lower mold forming hole of the lower bending mold match the bending radius of the bent pipe.

[0014] The beneficial effects of the present invention are:

[0015] The lower end of the guide block of the present invention is connected to the upper bending die, and the center of the guide block has a guide hole along the length direction. The diameter of the guide hole matches the diameter of the bent pipe. The diameter of the bent pipe can be adjusted by replacing the guide block with a guide hole of different diameters; the fixed block is a horizontally placed U-shaped clamping block, and the two side walls of the fixed block are respectively clamped on the upper end face of the upper bending die and the lower end face of the lower bending die to fasten the upper bending die and the lower bending die; the lower end face of the upper bending die and the upper end face of the lower bending die can be positioned horizontally through relative longitudinal sliding grooves and sliding flat keys, and can slide longitudinally, and the relative position of the upper die forming hole and the lower die forming hole can be adjusted to realize the adjustment of the radius of the bent pipe; the lower end face of the upper bending die and the upper end face of the lower bending die respectively have multiple groups of relative transverse adjustment grooves, and different bending radius values ​​can be determined by selecting transverse adjustment grooves with different spacings and fixing them with adjustment flat keys.

[0016] The present invention has a simple structure and is easy to use. It changes the original push-bending die with a fixed aperture and a fixed bending radius into a combined structure. The combined structure can adjust the diameter and bending radius of the bent pipe, and can bend metal pipes with different diameters and bending radii. The adjustment process is quick and convenient, which greatly improves the application range of the pipe bending die, reduces production costs, and improves efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 It is a structural diagram of the upper bending die;

[0019] Figure 3 It is a structural diagram of the lower bending die;

[0020] Figure 4 It is a schematic diagram of the offset δ between the upper bending die and the lower bending die being 4 mm;

[0021] Figure 5 It is a schematic diagram of the offset δ between the upper bending die and the lower bending die being 6 mm;

[0022] Figure 6 It is a schematic diagram of the offset δ between the upper bending die and the lower bending die being 8 mm;

[0023] Figure 7 Schematic diagram of a bent pipe with an offset δ of 8 mm between the upper bending die and the lower bending die and an initial outer diameter of 8 mm;

[0024] Figure 8 Schematic diagram of a pipe bend with an offset δ of 8 mm between the upper bending die and the lower bending die and an initial outer diameter of 10 mm;

[0025] Figure 9Schematic diagram of a pipe bend with an offset δ of 8 mm between the upper bending die and the lower bending die and an initial outer diameter of 12 mm;

[0026] Figure 10 Schematic diagram of a pipe bend with an offset δ of 6 mm between the upper bending die and the lower bending die and an initial outer diameter of 8 mm;

[0027] Figure 11 Schematic diagram of a pipe bend with an offset δ of 6 mm between the upper bending die and the lower bending die and an initial outer diameter of 10 mm;

[0028] Figure 12 Schematic diagram of a pipe bend with an offset δ of 6 mm between the upper bending die and the lower bending die and an initial outer diameter of 12 mm;

[0029] Figure 13 It is a schematic diagram of a pipe bending using an existing push-bending die.

[0030] The markings in the figure are as follows: upper bending die 1, lower bending die 2, guide block 3, fixed block 4, square groove 5, upper die forming hole 6, lower die forming hole 7, guide hole 8, longitudinal sliding groove 9, transverse adjustment groove 10, sliding flat key 11, adjustment flat key 12, tightening screw 13, bent pipe 14, and misalignment amount δ. DETAILED DESCRIPTION

[0031] The present invention is composed of an upper bending die 1, a lower bending die 2, a guide block 3, a fixed block 4, a sliding flat key 11, an adjusting flat key 12, and a pressing screw 13.

[0032] Figure 1 The lower end of the guide block 3 is connected to the upper bending die 1, and the lower bending die 2 is placed below the upper bending die 1. The fixing block 4 is a horizontal U-shaped clamping block, and the side walls of the fixing block 4 clamp the upper bending die 1 and the lower bending die 2 in place. The bent pipe 14 is bent through the guide hole 8 in the center of the guide block 3, the upper die forming hole of the upper bending die, and the lower die forming hole of the lower bending die. By replacing the guide block 3 with a guide hole 8 of different diameters, the diameter of the bent pipe 14 can be adjusted; by adjusting the relative position of the upper bending die 1 and the lower bending die 2 longitudinally, the bending radius of the bent pipe 14 can be adjusted.

[0033] Figure 1 、 3 It shows that the upper bending die 1 is a square steel block, with a square groove 5 in the upper center of the upper bending die 1, and an upper die forming hole 6 in the lower center of the upper bending die 1. The upper die forming hole 6 in the lower part of the upper bending die 1 is a conical hole, and there is a circular hole in the center of the square groove 5 connected to the upper die forming hole 6.

[0034] Figure 1 、 2The depth of the square groove 5 in the upper bending die 1 is half the thickness of the upper bending die. The square groove 5 is used to accommodate the guide block 3. The annular circumference of the conical hole in the upper die forming hole 6 below the square groove 5 has a circular arc that bulges toward the central axis of the circular hole. The small diameter end of the conical hole in the upper die forming hole 6 is oppositely connected to the central circular hole of the square groove 5, and the large diameter end of the conical hole in the upper die forming hole 6 is oppositely connected to the upper end of the lower die forming hole 7 of the lower bending die 2. The bent pipe 14 enters the lower die forming hole 7 of the lower bending die 2 through the upper die forming hole 6.

[0035] Figure 1 、 3 The lower bending die 2 is a square steel block identical to the upper bending die 1, with the lower plate surface of the upper bending die 1 and the upper plate surface of the lower bending die 2 stacked relative to each other. A lower die forming hole 7 is located in the center of the lower bending die 2, which is connected to the upper die forming hole 6 of the upper bending die 1. The lower die forming hole 7 of the lower bending die 2 is an upright circular hole of unequal diameter, with the diameters at both ends being larger than the center diameter. The circumference of the hole wall of the lower die forming hole 7 is a circular arc surface that protrudes toward the central axis of the lower die forming hole 7.

[0036] Figure 1 The guide block 3 is an upright rectangular steel block. Its ends are square, matching the square grooves 5 of the upper bending die 1. The lower end of the guide block 3 is embedded in the square grooves 5 of the upper bending die 1. A guide hole 8 is defined along the center of the guide block 3 along its length. The diameter of the guide hole 8 matches the diameter of the bent tube 14. The lower end of the guide hole 8 is connected to the upper end of the forming hole 6 of the upper die. In use, by replacing the guide block 3 with a guide hole 8 of different diameters, bent tubes 14 of varying diameters can be bent.

[0037] Figure 1 It is shown that the U-shaped top surface of the fixed block 4 is vertical, and the U-shaped top surface of the fixed block 4 is located on one side of the upper bending die 1 and the lower bending die 2. The two side walls of the U of the fixed block 4 are respectively opposite to the upper end surface of the upper bending die 1 and the lower end surface of the lower bending die 2. There are two threaded holes on the side wall of the fixed block 4 opposite to the upper end surface of the upper bending die, and the tightening screw 13 is screwed into the threaded hole to be tightly connected with the upper end surface of the upper bending die 1.

[0038] Figure 1 、 2Figures 3 and 4 show that the lower end surface of the upper bending die 1 has longitudinal sliding grooves 9 on opposite ends of the edge. The longitudinal sliding grooves 9 are perpendicular to the edges of the square body of the upper bending die 1 and are located midway between the two ends of the upper bending die 1. The upper end surface of the lower bending die 2 has longitudinal sliding grooves 9 on opposite ends of the edge, which are opposite to the longitudinal sliding grooves 9 on the lower end surface of the upper bending die 1. The length, width, and depth of the two longitudinal sliding grooves 9 on the lower end surface of the upper bending die 1 are identical to those on the upper end surface of the lower bending die 2. The upper and lower ends of the two sliding keys 11 are respectively embedded in the longitudinal sliding grooves 9 on the opposite ends of the upper and lower bending dies 1 and 2. The upper and lower bending dies 1 and 2 slide with the sliding keys 11 along the length of the longitudinal sliding grooves 9. The longitudinal sliding grooves 9 and sliding keys 11 enable the upper and lower bending dies 1 and 2 to slide relative to each other in the longitudinal direction without causing any lateral displacement. The longitudinal sliding can cause the upper die forming hole 6 of the upper bending die 1 and the lower die forming hole 7 of the lower bending die 2 to move in the longitudinal direction, thereby changing the curvature of the bent pipe passing through the upper die forming hole 6 and the lower die forming hole 7, thereby achieving the purpose of adjusting the bending radius of the pipe.

[0039] Figure 1 、 2 3 shows that the other two opposite ends of the lower end face of the upper bending die 1 and the upper end face of the lower bending die 2 have a plurality of corresponding transverse adjustment grooves 10, and the plurality of transverse adjustment grooves 10 are respectively perpendicular to the edges of the square bodies of the upper bending die 1 and the lower bending die 2. The plurality of transverse adjustment grooves 10 on the lower end face of the upper bending die 1 and the upper end face of the lower bending die 2 are respectively located in the middle position of the two end edges of the lower end face of the upper bending die 1 and the two end edges of the upper end face of the lower bending die 2. The length, width and depth of the plurality of transverse adjustment grooves 10 on the lower end face of the upper bending die 1 and the upper end face of the lower bending die 2 are the same and can be matched arbitrarily.

[0040] Figure 1 、 2 3 shows that the multiple transverse adjustment grooves 10 on the lower end face of the upper bending die 1 are respectively combined with the multiple transverse adjustment grooves 10 on the upper end face of the lower bending die, and the offset amount δ between the combined upper bending die 1 and the lower bending die 2 corresponds to the bending radius of the bent pipe 14, and the two adjustment flat keys 12 are respectively embedded in a group of transverse adjustment grooves 10 combined with the lower end face of the upper bending die and the upper end face of the lower bending die, and position the upper bending die 1 and the lower bending die 2. After positioning, the upper die forming hole 6 of the upper bending die 1 and the lower die forming hole 7 of the lower bending die 2 match the bending radius of the bent pipe 14.

[0041] Specifically, the center axis spacings of the four transverse adjustment slots 10 of the upper bending die 1 are 12 mm, 12 mm, and 12 mm, respectively, while the center axis spacings of the four transverse adjustment slots 10 of the lower bending die 2 are 14 mm, 14 mm, and 14 mm, respectively. The distances between the center axis of the four transverse adjustment slots 10 of the upper bending die 1 and the end surface of the upper bending die 1 are 29 mm, 41 mm, 53 mm, and 65 mm, respectively, while the distances between the center axis of the four transverse adjustment slots 10 of the lower bending die 2 and the end surface of the lower bending die 2 are 31 mm, 45 mm, 59 mm, and 73 mm, respectively.

[0042] Figure 4 、 5 Figures 6 and 7 show that when the offset δ between the upper bending die 1 and the lower bending die 2 is 4 mm, the second transverse adjustment slot 10 of the upper bending die 1 is aligned with the second transverse adjustment slot 10 of the lower bending die 2 and secured by the adjustment flat key 12. When the offset δ between the upper bending die 1 and the lower bending die 2 is 6 mm, the third transverse adjustment slot 10 of the upper bending die 1 is aligned with the third transverse adjustment slot 10 of the lower bending die 2 and secured by the adjustment flat key 12. When the offset δ between the upper bending die 1 and the lower bending die 2 is 8 mm, the second transverse adjustment slot 10 of the upper bending die 1 is aligned with the third transverse adjustment slot 10 of the lower bending die 2 and secured by the adjustment flat key 12.

[0043] Figure 7 、 8 9 shows that when the offset δ between the upper bending die 1 and the lower bending die 2 is 8 mm, replacing the guide block 3 with a guide hole 8 of different diameters can perform bending operations on the bent pipe 14 with an initial outer diameter of 8 mm, an initial outer diameter of 10 mm, and an initial outer diameter of 12 mm.

[0044] Figure 10 、 11 , 12 show that when the offset δ between the upper bending die 1 and the lower bending die 2 is 6 mm, replacing the guide block 3 with a guide hole 8 of different diameters can perform bending operations on the bent pipe 14 with an initial outer diameter of 8 mm, an initial outer diameter of 10 mm, and an initial outer diameter of 12 mm.

[0045] Figure 7-12 It is shown that the offset δ between the upper bending die 1 and the lower bending die 2 is different, and the bending radius of the final formed pipe is different, which means that this type of mold can be used to bend pipes with multiple bending radii with only one set of molds; at the same time, it is only necessary to replace the guide block 3 with different center hole sizes to achieve bending of pipes with different initial outer diameters. The mold and forming process are simple and feasible.

[0046] The bending forming die of the present invention has less contact area with the pipe during the bending process. The reduction of the friction area not only reduces die wear, but also facilitates the metal flow of the pipe, reduces the thinning degree of the outer side, and improves the forming quality.

[0047] Figure 13 It shows that the existing push-bending mold uses a fixed guide hole and bending mold, which can only bend pipes with one diameter and bending radius, greatly reducing work efficiency.

[0048] The method of use of the present invention is as follows:

[0049] (1) According to the diameter of the pipe to be bent, select a guide block 3 with a corresponding guide hole 8, and insert the lower end of the guide block 3 into the square groove 5 of the upper bending die 1;

[0050] (2) According to the shape of the pipe to be bent, determine the offset δ between the upper bending die 1 and the lower bending die 2, move the upper bending die 1 along the sliding flat key 9, so that the offset δ between the upper bending die 1 and the lower bending die 2 meets the requirements of the bending radius, and the upper bending die 1 and the lower bending die 2 corresponding to the offset δ are opposite to each other in the transverse adjustment groove 10;

[0051] (3) Insert the adjustment flat key 12 into the relative transverse adjustment slots 10 of the upper bending die 1 and the lower bending die 2, and adjust the flat key 12 to position the upper bending die 1 and the lower bending die 2 in the longitudinal direction;

[0052] (4) Tighten the clamping screw 13 of the fixing block 4 on the upper end surface of the upper bending die 1 to fix the upper bending die 1 and the lower bending die 2;

[0053] (5) Install the mold on the press and place the tube into the guide hole 8 in the guide block 3;

[0054] (6) Start the press, and the tube blank is fed along the guide hole 8 of the guide block 3 under the action of the end pushing force, and contacts the annular hole wall of the upper die forming hole 6 of the upper bending die 1 and the lower die forming hole 7 of the lower bending die 2, thereby realizing the bending of the tube blank;

[0055] (7) Take out the elbow 14 and measure its dimensions;

[0056] (8) If the size of the bent pipe 14 is qualified, the production is completed; if there is a deviation in the size of the pipe fitting, the offset δ between the upper bending die 1 and the lower bending die 2 is adjusted, and the above steps are repeated until the size of the pipe fitting is qualified.

[0057] An embodiment of the present invention is as follows:

[0058] The length of the upper bending die 1 is 100 mm, the width is 100 mm, and the thickness is 20 mm. The side length of the square groove 5 is 40 mm and the height is 10 mm. The upper end diameter of the upper die forming hole 6 is 15 mm, the lower end diameter is 35 mm, and the height is 10 mm.

[0059] The length of the lower bending die 2 is 100 mm, the width is 100 mm, and the thickness is 20 mm. The upper diameter of the lower die forming hole 7 is 35 mm, the middle diameter is 15 mm, and the lower diameter is 35 mm.

[0060] The height of the guide block 3 is 40 mm, the side length of the square on the top surface is 40 mm, and the diameters of the guide holes 8 are 8.5 mm, 10.5 mm, and 12.5 mm respectively;

[0061] The length of the fixing block 4 is 80 mm, the width is 30 mm, the height is 60 mm, and the distance between the two side walls is 40 mm;

[0062] The longitudinal sliding groove 9 has a length of 20 mm, a width of 6 mm and a depth of 3 mm;

[0063] The transverse adjustment slots 10 are 20 mm long, 6 mm wide, and 3 mm deep. The center axis spacings of the four transverse adjustment slots 10 in the upper bending die 1 are 12 mm, 12 mm, and 12 mm, respectively. The center axis spacings of the four transverse adjustment slots 10 in the lower bending die 2 are 14 mm, 14 mm, and 14 mm, respectively. The distances between the center axis of the four transverse adjustment slots 10 in the upper bending die 1 and the end face of the upper bending die 1 are 29 mm, 41 mm, 53 mm, and 65 mm, respectively. The distances between the center axis of the four transverse adjustment slots 10 in the lower bending die 2 and the end face of the lower bending die 2 are 31 mm, 45 mm, 59 mm, and 73 mm, respectively.

[0064] The sliding flat key 11 has a length of 20 mm, a width of 6 mm, and a thickness of 6 mm;

[0065] Adjust the length of the flat key 12 to 20 mm, the width to 6 mm, and the thickness to 6 mm;

[0066] The offset amounts δ are 4 mm, 6 mm, and 6 mm respectively.

Claims

1. A push-bending die with adjustable pipe diameter and bending radius, characterized by: The invention comprises an upper bending die (1), a lower bending die (2), a guide block (3), a fixed block (4), a sliding flat key (11), and an adjusting flat key (12). The upper bending die (1) and the lower bending die (2) are respectively identical square steel blocks. The lower plate surface of the upper bending die (1) and the upper plate surface of the lower bending die (2) are stacked relative to each other. A square groove (5) is provided at the upper center of the upper bending die (1). An upper die forming hole (6) is provided at the lower center of the upper bending die (1). A circular hole is provided at the center of the square groove (5) and is connected to the upper die forming hole (6). A lower die forming hole (7) is provided at the center of the lower bending die (2). The lower die forming hole (7) of (2) is connected to the upper die forming hole (6) of the upper bending die (1), the guide block (3) is a vertical rectangular steel block, the two ends of the guide block (3) are squares that match the square groove (5) of the upper bending die (1), the lower end of the guide block (3) is embedded in the square groove (5) of the upper bending die (1), the center of the guide block (3) has a guide hole (8) along the length direction, the diameter of the guide hole (8) matches the diameter of the bend (14), the lower end of the guide hole (8) is connected to the upper end of the upper die forming hole (6), the fixed block (4) is a U-shaped block, the fixed block ( The two side walls of the U-shape of 4) are respectively clamped on the upper side of the upper bending die (1) and the lower side of the lower bending die (2), and the opposite two end edges of the lower end surface of the upper bending die (1) and the opposite two end edges of the upper end surface of the lower bending die (2) are respectively provided with opposite longitudinal sliding grooves (9), and the longitudinal sliding grooves (9) are respectively perpendicular to the two end edges of the upper bending die (1) and the lower bending die (2). Two sliding flat keys (11) are respectively embedded in the opposite longitudinal sliding grooves (9) at the two ends of the lower end surface of the upper bending die (1) and the two ends of the upper end surface of the lower bending die (2). The upper bending die (1) and the lower bending die (2) are arranged along the longitudinal sliding grooves ( 9) is in sliding fit with the sliding flat key (11) in the longitudinal direction, and the other two opposite ends of the lower end surface of the upper bending die (1) and the upper end surface of the lower bending die (2) are respectively provided with a plurality of corresponding transverse adjustment grooves (10), the plurality of transverse adjustment grooves (10) are respectively perpendicular to the two end edges of the upper bending die (1) and the lower bending die (2), and the distances between the plurality of transverse adjustment grooves (10) are not equal, and two adjustment flat keys (12) are respectively embedded in a group of transverse adjustment grooves (10) opposite to the lower end surface of the upper bending die (1) and the upper end surface of the lower bending die (2) to position the upper bending die (1) and the lower bending die (2); The depth of the square groove (5) of the upper bending die (1) is 1 / 2 of the thickness of the upper bending die (1); the upper die forming hole (6) at the lower part of the upper bending die (1) is a conical hole; the annular circumferential surface of the conical hole has an arc that protrudes toward the central axis of the hole; the small diameter end of the conical hole is connected to the central circular hole of the square groove (5); and the large diameter end of the conical hole is connected to the upper end of the lower die forming hole (7) of the lower bending die (2); The lower die forming hole (7) of the lower bending die (2) is a vertical unequal diameter circular hole, the diameters of the two ends of the lower die forming hole (7) are larger than the middle diameter, and the circumference of the hole wall of the lower die forming hole (7) is a circular arc surface protruding toward the central axis of the lower die forming hole (7).

2. The push-bending die with adjustable pipe diameter and bending radius according to claim 1, characterized in that: The U-shaped top surface of the fixing block (4) is placed vertically, and the U-shaped top surface of the fixing block (4) is located on one side of the upper bending die (1) and the lower bending die (2). The two side walls of the U-shape of the fixing block (4) are respectively clamped on the upper side of the upper bending die (1) and the lower side of the lower bending die (2). There are two threaded holes on the side wall of the fixing block (4) opposite to the upper side of the upper bending die (1), and the tightening screws (13) are screwed into the threaded holes to be tightly connected with the upper side of the upper bending die (1).

3. The push-bending die with adjustable pipe diameter and bending radius according to claim 1, characterized in that: The two longitudinal sliding grooves (9) on the lower end surface of the upper bending die (1) and the two longitudinal sliding grooves (9) on the upper end surface of the lower bending die (2) are respectively located in the middle positions of the two end edges of the upper bending die (1) and the lower bending die (2); the length, width and depth of the two longitudinal sliding grooves (9) on the lower end surface of the upper bending die (1) are respectively the same as the length, width and depth of the two longitudinal sliding grooves (9) on the upper end surface of the lower bending die (2); the upper half and the lower half of the two sliding flat keys (11) are respectively embedded in the opposite longitudinal sliding grooves (9) at the two ends of the upper bending die (1) and the lower bending die (2).

4. The push-bending die with adjustable pipe diameter and bending radius according to claim 1, characterized in that: The plurality of transverse adjustment grooves (10) on the lower end surface of the upper bending die (1) and the upper end surface of the lower bending die (2) are respectively located in the middle of the two end edges of the lower end surface of the upper bending die (1) and the two end edges of the upper end surface of the lower bending die (2); the length, width and depth of the transverse adjustment grooves (10) on the lower end surface of the upper bending die (1) are respectively the same as the length, width and depth of the transverse adjustment grooves (10) on the upper end surface of the lower bending die (2); the plurality of transverse adjustment grooves (10) on the lower end surface of the upper bending die (1) are respectively the same as the plurality of transverse adjustment grooves (10) on the upper end surface of the lower bending die (2). The transverse adjustment grooves (10) are combined with each other, and the offset δ between the combined upper bending die (1) and the lower bending die (2) corresponds to the bending radius of the bent pipe (14). Two adjustment flat keys (12) are respectively embedded in a group of transverse adjustment grooves (10) combined with the lower end surface of the upper bending die (1) and the upper end surface of the lower bending die (2), and the upper bending die (1) and the lower bending die (2) are positioned. After positioning, the upper die forming hole (6) of the upper bending die (1) and the lower die forming hole (7) of the lower bending die (2) match the bending radius of the bent pipe (14).

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