CN113926871A

CN113926871A - Cold extrusion forming die for press elbow and elbow forming method

Info

Publication number: CN113926871A
Application number: CN202111407572.8A
Authority: CN
Inventors: 颜怡; 绕华兵
Original assignee: New Torch Technology Co ltd
Current assignee: New Torch Technology Co ltd
Priority date: 2021-11-24
Filing date: 2021-11-24
Publication date: 2022-01-14

Abstract

The invention provides a clamping elbow cold extrusion forming die and an elbow forming method, and relates to the technical field of clamping elbow cold extrusion forming dies and forming methods. Through rotatory injection lubricating oil of rotatory nozzle to the pipe inner wall, make lubricating oil evenly splash on the internal perisporium of pipe, lubricating oil gets into the die cavity along the pipe flows down, lubricates the removal of pipe blank in the die cavity to effectively reduced coefficient of friction, played fine lubricated effect, showing the cold extrusion forming effect that has promoted the elbow, avoid the elbow to appear wrinkling and defect such as cross section distortion.

Description

Cold extrusion forming die for press elbow and elbow forming method

Technical Field

The invention relates to the technical field of elbow forming dies and forming methods, in particular to the technical field of clamping and pressing elbow cold extrusion forming dies and forming methods.

Background

The elbow is a pipe joint used for pipe turning or changing fluid direction, the proportion of the elbow in all pipe fittings used in a pipe system is about 80%, the elbow is made of common materials such as cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, nonferrous metal and plastics, different forming processes are required to be selected for elbows of different materials or wall thicknesses, and the traditional metal elbow forming processes comprise casting or post-cold-heading machining, hot-push forming, stamping-butt welding and the like. However, products produced by the processes have long existence period, large blank machining allowance, pollution caused by a pouring process, high technical content required by a welding forming process and the like. The cold extrusion forming process has been rapidly developed in recent years due to the advantages of convenience, rapidness, attractive appearance of an elbow, uniform wall thickness, small size deviation and the like, and the traditional cold extrusion forming process comprises the following steps: putting the diameter core rod into a die, and applying axial extrusion to the tube blank through a punch head to enable the tube blank to generate plastic deformation; and removing the mold, and removing the diameter core rod to obtain the elbow. However, the following disadvantages exist with this approach: firstly, the friction coefficient is large, and the friction coefficient is large when the tube blank is subjected to plastic deformation in a die, so that the defects of wrinkling, cross section distortion and the like of a formed elbow are caused; secondly, after extrusion is finished, the diameter core rod is firmly clamped on the tube blank and is difficult to remove.

Disclosure of Invention

The invention provides a clamping elbow cold extrusion forming die and an elbow forming method, and solves the problems that in the prior art, a cold extrusion forming process is large in friction coefficient and a diameter core rod is difficult to remove.

The technical scheme of the invention is realized as follows:

a cold extrusion forming die for a press elbow comprises a base, a pair of movable dies, a pair of opening and closing oil cylinders, a core die, a pressing oil cylinder, a punch, a rotary nozzle and a guide cylinder, wherein the pair of movable dies are respectively movably arranged on the base through a guide mechanism, corresponding cavities are respectively arranged on the opposite side parts of the paired movable dies, the core die is detachably and fixedly arranged in the cavities of the paired movable dies, the paired opening and closing oil cylinders are respectively and fixedly arranged on the base, piston rods of the paired opening and closing oil cylinders are respectively and fixedly connected with the paired movable dies, the downward-pressing oil cylinder is fixedly arranged on the base through a bracket, the guide cylinder is fixedly arranged on the bracket, and is corresponding to the upper end part of the cavity, the punch is fixedly arranged on a piston rod of the lower pressure oil cylinder, the lower part of the punch is provided with a pressing step surface, the punch is movably inserted in the guide cylinder, and the rotary nozzle is arranged at the lower end part of the punch.

Further, the core mold comprises a cylindrical mold, an inner arc mold, an outer arc mold and a locking bolt, the cylindrical mold is in a cylindrical shape with the front end closed and the rear end opened, the inner arc mold and the outer arc mold are respectively and fixedly connected with the front end of the cylindrical mold in a detachable mode through the locking bolt, and the head of the locking bolt is located in the cylindrical mold.

Furthermore, a through hole is formed in the front end portion of the column die, threaded holes are formed in the end portions of the inner arc die and the outer arc die respectively, and the locking bolts penetrate through the through holes and are in threaded connection with the threaded holes of the inner arc die and the outer arc die respectively.

Furthermore, the guide mechanism comprises a guide groove, the guide groove is fixedly arranged on the base, the paired movable dies are respectively and movably clamped on the guide groove, a guide rod is arranged on one movable die, a guide hole corresponding to the guide rod is formed in the other movable die, and one movable die is inserted into the guide hole of the other movable die through the guide rod.

Furthermore, a first oil discharge hole is formed in the front end of the column die, corresponding positioning notches are formed in the opposite side portions of the paired moving dies respectively, a positioning boss is arranged at the rear end of the column die and clamped in the positioning notches of the paired moving dies, a second oil discharge hole communicated with the cavity is formed in the positioning boss, and a third oil discharge hole corresponding to the second oil discharge hole is formed in the paired moving dies.

Furthermore, the rotary nozzle comprises a shell, a hollow shaft, a ring sleeve, paired radial bearings, paired thrust bearings, a sealing ring and a nozzle body, wherein an oil duct is arranged inside the punch, an oil nozzle communicated with the oil duct is arranged on the punch, the shell is fixedly arranged at the lower end part of the punch, the hollow shaft is movably inserted into the shell, an annular limiting plate is arranged on the hollow shaft, the paired thrust bearings are respectively sleeved outside the hollow shaft and positioned at the upper side and the lower side of the annular limiting plate, the paired radial bearings are respectively sleeved outside the hollow shaft, the ring sleeve is clamped in the shell, the ring sleeve is positioned between the paired radial bearings, a ring groove is arranged on the outer peripheral wall of the hollow shaft above the thrust bearings, the sealing ring is clamped in the ring groove and contacted with the inner wall of the shell, a pore passage communicated with the oil duct and the hollow shaft is arranged on the shell, and the lower end part of the hollow shaft penetrates out of the shell, the spray head body is fixedly arranged on the lower end part of the hollow shaft and communicated with the hollow shaft, and inclined holes uniformly distributed along the circumferential direction are formed in the side wall of the spray head body.

An elbow forming method based on a clamping elbow cold extrusion forming die comprises the following steps:

step 1: the tube blank is placed in the upper parts of the guide cylinder and the cavity, the punch is driven to move downwards through the downward pressing oil cylinder, and the downward pressing step surface of the punch is abutted to the upper end surface of the tube blank;

step 2: the lower pressing oil cylinder drives the punch to extrude the tube blank, so that the tube blank moves in the cavity, the tube blank is limited by the inner wall of the cavity and the core die and is bent, and meanwhile, lubricating oil is sprayed to the inner wall of the tube blank in a rotating mode through the rotating nozzle to lubricate the movement of the tube blank in the cavity;

and step 3: the paired movable dies are driven to open through the paired opening and closing oil cylinders, the tube blank and the core die clamped in the tube blank are taken out, tools are used for stretching into the column die from the rear part of the column die, the locking bolts are dismounted, the column die is separated from the inner arc die and the outer arc die respectively, then the column die is taken out from the tube blank, and then the outer arc die and the inner arc die are taken out from the tube blank in sequence, so that the elbow forming of the tube blank is completed.

The invention adopts the technical proposal to achieve the following beneficial effects:

1. drive the punch through the lower pressure hydro-cylinder and extrude the pipe, when making the pipe remove in the die cavity, through rotatory nozzle to the rotatory injection lubricating oil of pipe inner wall, make the even splash of lubricating oil on the internal perisporium of pipe, lubricating oil gets into the die cavity along the pipe flows down, lubricate the removal of pipe blank in the die cavity, thereby effectively reduced coefficient of friction, played fine lubricated effect, show the cold extrusion moulding effect that has promoted the elbow, avoid the elbow to appear wrinkling and defect such as cross section distortion.

2. When the punch is used for extruding the pipe blank and the core die needs to be taken out of the pipe blank, firstly, a tool is used for stretching into the column die from the rear part of the column die, the locking bolt is dismounted, the column die is separated from the inner arc die and the outer arc die respectively, then the column die is taken out of the pipe blank, and then the outer arc die and the inner arc die are taken out of the pipe blank in sequence.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a sectional view A-A of the cold extrusion molding die for a snap bend of the present invention shown in FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 1 at B;

FIG. 4 is an enlarged view of a portion of FIG. 1 at C;

FIG. 5 is a cross-sectional view taken along line N-N of FIG. 4;

FIG. 6 is an enlarged partial schematic view of FIG. 1 at D;

FIG. 7 is a cross-sectional view of the cold extrusion mold for a snap bend of the present invention shown in FIG. 1 taken along line M-M;

FIG. 8 is a schematic structural diagram of the movable mold shown in FIG. 1;

fig. 9 is a schematic view of the structure of the core mold;

FIG. 10 is a cross-sectional view of FIG. 9;

FIG. 11 is a top view of FIG. 9;

FIG. 12 is a right side view of FIG. 9;

FIG. 13 is a left side view of FIG. 9;

FIG. 14 is an enlarged partial schematic view at H of FIG. 2;

figures 15 and 16 are schematic views of a method of forming bends in accordance with the present invention;

FIG. 17 is an enlarged partial schematic view of FIG. 15 at W;

FIG. 18 is an enlarged partial schematic view at R of FIG. 16;

figure 19 is a schematic view of the elbow after forming.

In the drawings, the parts corresponding to the reference numerals are as follows:

1-a base, 2-a movable die, 3-an opening and closing oil cylinder, 4-a downward-pressing oil cylinder, 5-a punch, 6-a rotary spray head, 7-a guide cylinder, 8-a guide groove, 9-a guide rod, 10-a guide hole, 11-a piston rod of the opening and closing oil cylinder, 12-a cavity, 13-a positioning notch, 14-a column die, 15-an inner arc die, 16-an outer arc die, 17-a locking bolt, 18-a first oil discharge hole, 19-a positioning boss, 20-a second oil discharge hole, 21-a bracket, 22-a bracket, 23-a piston rod of the downward-pressing oil cylinder, 24-an oil passage, 25-an oil nozzle, 27-a shell, 28-a hollow shaft, 29-a ring sleeve, 30-a radial bearing, 31-a thrust bearing and 32-a sealing ring, 33-a spray head body, 34-an annular limiting plate, 35-a hole channel, 36-an inclined hole, 37-a pipe blank, 38-a clearance, 39-a through hole, 40-a threaded hole, 41-a third oil discharge hole and 42-a downward pressing step surface.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 14, a cold extrusion forming die for a press elbow comprises a base 1, a pair of movable dies 2, a pair of opening and closing oil cylinders 3, a core die, a pressing oil cylinder 4, a punch 5, a rotary nozzle 6 and a guide cylinder 7, wherein the pair of movable dies 2 are respectively and movably mounted on the base 1 through guide mechanisms, and the specific structures of the guide mechanisms and the specific connection relation with the base 1 are as follows: the guide mechanism comprises guide grooves 8, the guide grooves 8 are fixedly installed on the base 1, the paired movable dies 2 are movably clamped on the guide grooves 8 respectively, a guide rod 9 is arranged on one movable die 2, a guide hole 10 corresponding to the guide rod 9 is formed in the other movable die 2, and one movable die 2 is inserted into the guide hole 10 of the other movable die 2 through the guide rod 9.

Corresponding cavities 12 are respectively arranged on the opposite side parts of the paired movable dies 2, the core die is detachably and fixedly arranged in the cavities 12 of the paired movable dies 2, and the specific structure of the core die and the specific connection relation with the movable dies 2 are as follows: the core die comprises a column die 14, an inner arc die 15, an outer arc die 16 and a locking bolt 17, the column die 14 is in a cylindrical shape with a closed front end and an open rear end, the inner arc die 15 and the outer arc die 16 are respectively and fixedly connected with the front end part of the column die 14 through the locking bolt 17 in a detachable mode, the head part of the locking bolt 17 is positioned in the cylindrical column die 14, corresponding positioning notches 13 are respectively formed in the opposite side parts of the paired moving dies 2, a positioning boss 19 is arranged at the rear end part of the column die 14, and the positioning boss 19 is clamped in the positioning notch 13 of the paired moving dies 2. The specific connection relationship among the inner arc mold 15, the outer arc mold 16, the locking bolt 17 and the column mold 14 is as follows: the front end of the column die 14 is provided with a through hole 39, the ends of the inner arc die 15 and the outer arc die 16 are respectively provided with a threaded hole 40, and the locking bolts 17 are respectively arranged in the through holes 39 in a penetrating way and are respectively in threaded connection with the threaded holes 40 of the inner arc die 15 and the outer arc die 16. A first oil discharge hole 18 is formed at a front end portion of the column mold 14, a second oil discharge hole 20 communicating with the cavity 12 is formed in the positioning boss 19, and third oil discharge holes 41 corresponding to the second oil discharge hole 20 are formed in the paired movable molds 2.

The pair of opening and closing oil cylinders 3 are respectively and fixedly arranged on the base 1, piston rods 11 of the pair of opening and closing oil cylinders 3 are respectively and fixedly connected with the pair of movable dies 2, the pressing oil cylinder 4 is fixedly arranged on the base 1 through a bracket 21, the guide cylinder 7 is fixedly arranged on the bracket 21 through a bracket 22 and corresponds to the upper end part of the cavity 12, the punch 5 is fixedly arranged on a piston rod 23 of the pressing oil cylinder 4, a pressing step surface 42 is arranged at the lower part of the punch 5, the punch 5 is movably inserted into the guide cylinder 7, and the rotary spray head 6 is arranged at the lower end part of the punch 5.

The specific structure of the rotary spray head 6 and the specific connection relationship with the punch 5 are as follows: the rotary spray head 6 comprises a shell 27, a hollow shaft 28, a ring sleeve 29, a pair of radial bearings 30, a pair of thrust bearings 31, a sealing ring 32 and a spray head body 33, an oil duct 24 is arranged in the punch 5, an oil nozzle 25 communicated with the oil duct 24 is arranged on the punch 5, the shell 27 is fixedly arranged at the lower end part of the punch 5, the hollow shaft 28 is movably inserted in the shell 27, an annular limiting plate 34 is arranged on the hollow shaft 28, the pair of thrust bearings 31 are respectively sleeved outside the hollow shaft 28 and positioned at the upper side and the lower side of the annular limiting plate 34, the pair of radial bearings 30 are respectively sleeved outside the hollow shaft 28, the ring sleeve 29 is clamped in the shell 27, the ring sleeve 29 is positioned between the pair of radial bearings 30, a ring groove is arranged on the outer peripheral wall of the hollow shaft 28 above the thrust bearings 31, the sealing ring 32 is clamped in the ring groove and is contacted with the inner wall of the shell 27, the casing 27 is provided with a duct 35 communicating with the oil passage 24 and the hollow shaft 28, the lower end of the hollow shaft 28 penetrates out of the casing 27, the sprinkler body 33 is fixedly mounted on the lower end of the hollow shaft 28 and is communicated with the hollow shaft 28, and the side wall of the sprinkler body 33 is provided with inclined holes 36 uniformly distributed along the circumferential direction.

Referring to fig. 15 to 18, an elbow molding method based on a clamping elbow cold extrusion molding die comprises the following steps:

step 1: the tube blank 37 is placed in the upper parts of the guide cylinder 7 and the cavity 12, when the tube blank 37 is placed in the guide cylinder 7, the punch 5 and the piston rod 23 of the lower pressing oil cylinder 4 can be detached firstly, after the tube blank 37 is placed in the guide cylinder 7, the punch 5 is fixedly installed on the piston rod 23 of the lower pressing oil cylinder 4, the punch 5 is driven to move downwards by the lower pressing oil cylinder 4, and the lower pressing step surface 42 of the punch 5 is abutted against the upper end surface of the tube blank 37;

step 2: the punch 5 is driven by the pressing-down oil cylinder 4 to extrude the tube blank 37, the tube blank 37 moves in the cavity 12, the tube blank 37 enters a gap 38 between the inner wall of the cavity 12 and the outer wall of the core mold, the blank tube 37 is restrained by the inner wall of the cavity 12 and the core mold, the blank tube 37 is plastically deformed, the blank tube 37 is bent, meanwhile, the oil nozzle 25 is communicated with high-pressure lubricating oil, after the high-pressure lubricating oil flows through the oil duct 24, the pore canal 35, the hollow shaft 28 and the rotary spray head 6, is sprayed from the inclined hole 36 of the rotary spray head 6, when the high-pressure lubricating oil is sprayed from the inclined hole 36, the rotating nozzle 6 is driven to rotate under the reaction force of the fluid, so that the rotating nozzle 6 rotationally sprays lubricating oil to the inner wall of the tube blank 37, lubricating the movement of the blank tube 37 in the cavity 12, and discharging the lubricating oil entering the cavity 12 from the first oil discharge hole 18, the second oil discharge hole 20 and the third oil discharge hole 41;

and step 3: the paired movable dies 2 are driven by the paired opening and closing cylinders 3 to open, the pipe blank 37 and the core die clamped in the pipe blank 37 are taken out, a tool is used to extend into the column die 14 from the rear part of the column die 14, the locking bolt 17 is removed, the column die 14 is separated from the inner arc die 15 and the outer arc die 16 respectively, then the column die 14 is taken out from the pipe blank 37, the outer arc die 16 and the inner arc die 15 are taken out from the pipe blank 37 in sequence, the elbow forming of the pipe blank 37 is completed, and the pipe blank 37 is made into an elbow as shown in fig. 19.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The utility model provides a card presses cold extrusion of turn-buckle mould, its characterized in that, includes base (1), mated movable mould (2), mated opening and shutting hydro-cylinder (3), mandrel, pushes down hydro-cylinder (4), drift (5), rotatory nozzle (6) and guide cylinder (7), mated movable mould (2) are respectively through guiding mechanism movable mounting on base (1), seted up corresponding die cavity (12) respectively on the relative lateral part of mated movable mould (2), mandrel detachably fixed mounting is in die cavity (12) of mated movable mould (2), mated opening and shutting hydro-cylinder (3) fixed mounting is respectively on base (1), piston rod (11) of the hydro-cylinder (3) that opens and shuts in pairs respectively with mated movable mould (2) fixed connection, push down hydro-cylinder (4) through bracket (21) fixed mounting on base (1), guide cylinder (7) fixed mounting is on bracket (21), the punch head (5) is fixedly arranged on a piston rod (23) of the lower pressure oil cylinder (4), a pressing step surface (42) is arranged at the lower part of the punch head (5), the punch head (5) is movably inserted into the guide cylinder (7), and the rotary spray head (6) is arranged at the lower end part of the punch head (5).

2. The press bending head cold extrusion molding die of claim 1, wherein the core die comprises a cylindrical die (14), an inner arc die (15), an outer arc die (16) and a locking bolt (17), the cylindrical die (14) is cylindrical with a closed front end and an open rear end, the inner arc die (15) and the outer arc die (16) are respectively and fixedly connected with the front end part of the cylindrical die (14) in a detachable way through the locking bolt (17), and the head part of the locking bolt (17) is positioned in the cylindrical die (14).

3. The press elbow cold extrusion molding die as claimed in claim 2, wherein a through hole (39) is formed at the front end portion of the column die (14), threaded holes (40) are respectively formed at the end portions of the inner arc die (15) and the outer arc die (16), and the locking bolts (17) are respectively inserted into the through holes (39) and are respectively in threaded connection with the threaded holes (40) of the inner arc die (15) and the outer arc die (16).

4. The press bending head cold extrusion molding die of claim 1, wherein the guide mechanism comprises a guide groove (8), the guide groove (8) is fixedly installed on the base (1), the paired movable dies (2) are respectively and movably clamped on the guide groove (8), a guide rod (9) is arranged on one movable die (2), a guide hole (10) corresponding to the guide rod (9) is formed in the other movable die (2), and one movable die (2) is inserted into the guide hole (10) of the other movable die (2) through the guide rod (9).

5. The press-bending cold extrusion molding die of claim 2, wherein a first oil discharge hole (18) is formed at the front end of the column die (14), corresponding positioning notches (13) are formed on the opposite side portions of the paired moving dies (2), a positioning boss (19) is formed at the rear end of the column die (14), the positioning boss (19) is clamped in the positioning notch (13) of the paired moving dies (2), a second oil discharge hole (20) communicated with the cavity (12) is formed on the positioning boss (19), and a third oil discharge hole (41) corresponding to the second oil discharge hole (20) is formed on the paired moving dies (2).

6. The cold extrusion molding die for the press bending head according to claim 1, wherein the rotary nozzle (6) comprises a housing (27), a hollow shaft (28), a ring sleeve (29), a pair of radial bearings (30), a pair of thrust bearings (31), a sealing ring (32) and a nozzle body (33), an oil passage (24) is arranged inside the punch (5), an oil nozzle (25) communicated with the oil passage (24) is arranged on the punch (5), the housing (27) is fixedly arranged at the lower end part of the punch (5), the hollow shaft (28) is movably inserted into the housing (27), an annular limiting plate (34) is arranged on the hollow shaft (28), the pair of thrust bearings (31) are respectively sleeved outside the hollow shaft (28) and positioned at the upper side and the lower side of the annular limiting plate (34), and the pair of radial bearings (30) are respectively sleeved outside the hollow shaft (28), the ring sleeve (29) is clamped in the shell (27), the ring sleeve (29) is positioned between the paired radial bearings (30), a ring groove is formed in the outer peripheral wall of the hollow shaft (28) positioned above the thrust bearing (31), the sealing ring (32) is clamped in the ring groove and is in contact with the inner wall of the shell (27), a pore passage (35) communicated with the oil passage (24) and the hollow shaft (28) is formed in the shell (27), the lower end part of the hollow shaft (28) penetrates out of the shell (27), the spray head body (33) is fixedly installed on the lower end part of the hollow shaft (28) and is communicated with the hollow shaft (28), and inclined holes (36) uniformly distributed along the circumferential direction are formed in the side wall of the spray head body (33).

7. The elbow forming method based on the clamping elbow cold extrusion forming die of claim 2 is characterized by comprising the following steps:

step 1: the tube blank (37) is placed in the upper parts of the guide cylinder (7) and the cavity (12), the punch (5) is driven to move downwards through the pressing cylinder (4), and the pressing step surface (42) of the punch (5) is abutted against the upper end surface of the tube blank (37);

step 2: the lower pressing oil cylinder (4) drives the punch (5) to extrude the tube blank (37), so that the tube blank (37) moves in the cavity (12), the tube blank (37) is limited through the inner wall of the cavity (12) and the core die, the tube blank (37) is bent, and meanwhile, lubricating oil is rotationally sprayed to the inner wall of the tube blank (37) through the rotary spray head (6), so that the movement of the tube blank (37) in the cavity (12) is lubricated;

and step 3: the paired movable dies (2) are driven to open through the paired opening and closing oil cylinders (3), the tube blank (37) and the core die clamped in the tube blank (37) are taken out, a tool is used for extending into the column die (14) from the rear part of the column die (14), the locking bolt (17) is dismounted, the column die (14) is separated from the inner arc die (15) and the outer arc die (16) respectively, then the column die (14) is taken out of the tube blank (37), the outer arc die (16) and the inner arc die (15) are taken out of the tube blank (37) in sequence, and elbow forming of the tube blank (37) is completed.