CN114951540A

CN114951540A - Elbow forming equipment and method

Info

Publication number: CN114951540A
Application number: CN202210691353.5A
Authority: CN
Inventors: 杨青云; 马俊普; 周振亚
Original assignee: 725th Research Institute of CSIC
Current assignee: 725th Research Institute of CSIC
Priority date: 2022-06-17
Filing date: 2022-06-17
Publication date: 2022-08-30

Abstract

The invention relates to the technical field of forming and processing of bent tubular parts, in particular to a device for forming an elbow. An elbow forming equipment includes: a mold and a forming machine. The mold is provided with a cavity, the cavity includes a feed cavity and a molding cavity, and the molding cavity is curved; the upper cavity of the mold is fastened to the lower mold, and each lower cavity corresponds to a corresponding upper cavity. The relative snap-fit forms an integral cavity. The forming machine includes a punch, one of which is provided on both sides of the die corresponding to the cavity. The elbow forming equipment of the present invention has the following advantages: the product meets the requirements of various technical indicators, effectively solves the problems of low material utilization rate, high cost and low efficiency, and can realize 0.5-inch to 2-inch, 45 The forming of copper-nickel alloy high-pressure elbow with ° and 90 ° improves the material utilization rate and forming efficiency, improves the quality stability and dimensional accuracy of the high-pressure elbow blank, reduces defects such as black skin and inclusions, and reduces costs.

Description

Elbow forming equipment and method

Technical Field

The invention relates to the technical field of forming and processing of bent tubular parts, in particular to forming equipment and a forming method of an elbow.

Background

The copper-nickel alloy is a material with excellent seawater corrosion resistance and marine organism pollution damage resistance, has excellent cold and hot processing performance and welding performance, and is widely applied to the fields of ships and ocean engineering.

The copper-nickel alloy high-pressure elbow is a forged elbow and comprises a plurality of forms of insert welding (SW), brazing (CB), threads (NPT) and the like, for example, the chinese utility model patent with publication number CN209393910U discloses a spatial corner elbow mold, which comprises an upper mold and a lower mold, the upper part of the upper section die is fixedly connected on the forging press through an upper connecting plate, the lower end of the upper section die is provided with an upper forging surface, the upper forging and pressing surface comprises a horizontal first forging and pressing surface and an obliquely upward second forging and pressing surface, the lower die is provided with a lower forging and pressing surface, the lower forging and pressing surface comprises a third forging and pressing surface matched with the first forging and pressing surface and a fourth forging and pressing surface matched with the second forging and pressing surface and inclined upwards, the upper forging surface is provided with a curved upper semicircular groove turning from the first forging surface to the second forging surface, the lower forging surface is provided with a curved lower semicircular groove which is matched with the upper semicircular groove and turns from the third forging surface to the fourth forging surface; the space corner elbow can be prepared by adopting a bending pressing method through the die, the shape and the inner hole size of the elbow are close to the size of a finished product, only the end part welding groove needs to be processed, and the cost of raw materials, heat treatment and machining can be saved. The traditional process adopts integral solid die forging forming, particularly, a closed space is formed between the movement of an upper die and a lower die on a press, so that metal is filled in the press to obtain the shape of a blank, the method has low material utilization rate (less than 50 percent), and a series of steps of upsetting, die forging, trimming and the like are required in the forming process, so that the production efficiency is low.

Disclosure of Invention

In view of this, the present invention aims to provide an elbow forming apparatus, which can form a blank with a hole at one end by using a convex punch, and solve the problems of low production efficiency, material waste, low material utilization rate, etc.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

an elbow forming apparatus comprising: the die is provided with a die cavity, the die cavity comprises a feeding cavity and a forming cavity, the feeding cavity is provided with an inlet on the side wall of the die, the feeding cavity extends towards the interior of the die and is communicated with the forming cavity, and the forming cavity is bent; the mold comprises:

the lower die is provided with two opposite lower cavities at two sides;

the upper die is buckled on the lower die, and each lower die cavity and the corresponding upper die cavity are buckled oppositely to form an integral die cavity;

a molding machine, comprising:

and the punch is arranged on two sides of the die corresponding to each cavity, and can reciprocate relative to the feeding cavity.

Further, the molding cavity comprises two straight parts and a bending part, and the bending part is arranged between the two straight parts.

Further, the included angle of the axis between the two straight-through parts is 90 degrees or 135 degrees.

Further, the diameter of the forming cavity near the two ends is larger than that of the middle part.

Further, be equipped with location structure on the mould, location structure includes:

at least two lower grooves are arranged on the surface of the lower cavity opening of the lower die, and the two lower grooves are arranged along the mutually vertical direction;

at least two upper grooves are arranged on the surface of the opening of the upper cavity of the upper die, and the two upper grooves are arranged along the mutually vertical direction;

when the upper die is buckled with the lower die, each lower groove is buckled with a corresponding upper groove to form a positioning hole;

and one positioning pin is arranged in each positioning hole.

Furthermore, two first positioning holes are respectively arranged on two sides of the die in the width direction, and the two first positioning holes are coaxially arranged;

and two second positioning holes are respectively arranged on two sides of the die in the length direction and are symmetrically arranged relative to the central line in the width direction.

Further, the punch is in a stepped shaft shape, and the diameter of one end close to the die is smaller than that of the end far away from the die.

Further, the molding machine further includes:

the lower die is fixed on the base;

the upper die is fixed on the upper plate, and the upper plate can move relative to the base;

a driver on which the punch is mounted.

A method of forming a bent pipe, characterized by a method of forming a bent pipe by the forming apparatus according to any one of the above, the forming method comprising:

s100, blanking: manufacturing a bent pipe blank through a bar stock;

s200, heating a blank, namely putting the blank into a heating device, and heating to 950-980 ℃;

s300, forming: placing the heated blank into a feeding cavity of a lower die, placing positioning pins into lower grooves of the lower die, buckling an upper die on the lower die, moving a punch from an inlet of the die to the blank direction, opening the upper die after moving to a preset position, and driving the punch to return by a driver to take out a semi-finished workpiece;

s400, acid washing: cleaning the surface oxide skin of the semi-finished workpiece;

s500, machining: machining according to design requirements, wherein machining comprises machining an inner hole of a workpiece;

s600, surface treatment, including polishing and sand blasting treatment of the surface of the workpiece, and meeting design requirements.

Further, the operations of the two blanks are performed simultaneously at least in steps S200 and S300.

Compared with the prior art, the elbow forming equipment has the following advantages:

the technical scheme has the advantages that the manufactured high-pressure elbow product meets the requirements of various technical indexes, the problems of low material utilization rate, high cost and low efficiency of the existing high-pressure elbow forming method are effectively solved, the forming of the copper-nickel alloy high-pressure elbows of 0.5-2 inches, 45 degrees and 90 degrees can be realized, the material utilization rate and the forming efficiency are improved, the quality stability and the size precision of the blank of the high-pressure elbow are improved, the defects of black skin, inclusion and the like are reduced, and the cost is reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is an exploded view of a bend forming apparatus according to an embodiment of the present invention;

fig. 2 is a perspective view of a lower mold according to an embodiment of the present invention.

Description of reference numerals:

100-die, 110-lower die, 111-die cavity, 1111-feeding cavity, 1112-forming cavity, 112-positioning hole, 1121-first positioning hole, 1122-second positioning hole, 120-upper die and 200-punch.

Detailed Description

It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

The descriptions in this document referring to "first", "second", "upper", "lower", etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," "upper," "lower," may explicitly or implicitly include at least one of the feature. In addition, the technical solutions in the embodiments may be combined with each other, but it is necessary that a person skilled in the art can realize the combination, and the technical solutions in the embodiments are within the protection scope of the present invention.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1, a molding apparatus for a bend includes: a mold 100 and a molding machine. As shown in fig. 2, the mold 100 is provided with a cavity 111, the cavity 111 comprises a feeding cavity 1111 and a forming cavity 1112, the feeding cavity 1111 is provided with an inlet at the side wall of the mold 100, the feeding cavity 1111 extends towards the interior of the mold 100 and is communicated with the forming cavity 1112, and the forming cavity 1112 is curved; the mold 100 includes a lower mold 110 and an upper mold 120. Two opposite lower cavities are arranged on two sides of the lower die 110; two opposite upper cavities are arranged on two sides of the upper die, the upper die 120 is buckled on the lower die 110, and each lower cavity and the corresponding upper cavity are buckled oppositely to form an integral cavity 111. The molding machine includes punches 200, one for each cavity 111, on both sides of the die 100, and the punches 200 are reciprocally movable with respect to the feed cavity 1111.

Two blanks can be simultaneously placed in the die 100, and two bends can be simultaneously formed by the two punches 200, respectively. The manufactured high-pressure elbow product meets the requirements of various technical indexes, effectively solves the problems of low material utilization rate, high cost and low efficiency of the existing high-pressure elbow forming method, can realize the forming of the copper-nickel alloy high-pressure elbows of 0.5-2 inches, 45 degrees and 90 degrees, improves the material utilization rate and the forming efficiency, improves the quality stability and the size precision of the blank of the high-pressure elbow, reduces the defects of black skin, inclusion and the like, and reduces the cost.

Specifically, the molding cavity 1112 comprises two straight portions and a curved portion, and the curved portion is disposed between the two straight portions.

A curved article is made by a forming cavity 1112 having a bend disposed between two through-going portions.

The angle between the two straight-through portions of the curved article can be greater than 0 ° and less than 180 °, and bends between 90 ° and 180 ° are easier to manufacture, with the usual angles of 90 ° and 135 ° being preferred in this embodiment.

Further, the diameter of the molding cavity 1112 is larger near both ends than in the middle.

The end heads of the internal thread parts at the two ends of the bent pipe can be directly manufactured through the forming cavity 1112 with the structure, the two ends of the bent pipe can be conveniently manufactured into hexagons in the later period through modes such as machining, the outer surface of the bent pipe is not required to be machined through modes such as welding or machining after forging, machining procedures are reduced, and machining cost is reduced.

Further, be equipped with location structure on the mould, location structure includes: lower groove, upper groove and locating pin (not shown). At least two lower grooves perpendicular to each other are provided on the surface of the lower cavity opening of the lower mold. And at least two mutually vertical upper grooves are arranged on the surface of the opening of the upper cavity of the upper die. When the upper mold is buckled with the lower mold, each lower groove is buckled with a corresponding upper groove to form a positioning hole 112. And one positioning pin is arranged in each positioning hole.

The upper die 120 and the lower die 110 are accurately matched by inserting the positioning pins into at least two mutually vertical positioning holes, the upper die cavity and the lower die cavity are correspondingly not staggered, and the quality of a product is ensured.

Preferably, one first positioning hole 1121 is provided along each of both sides in the width direction of the die 100, and the two first positioning holes 1121 are coaxially provided. One second positioning hole 1122 is disposed along each of both sides of the mold 100 in the longitudinal direction, and the two second positioning holes 1122 are symmetrically disposed with respect to a center line in the width direction.

Two positioning holes 112 are respectively arranged in the length direction and the width direction, one group is in the same straight line, and the other group is symmetrical to the central line, so that the precise matching of the upper die 120 and the lower die 110 is further ensured.

Further, the punch 200 is in a stepped shaft shape, and the diameter of the end close to the die is smaller than the diameter of the end far away from the die.

When extruding the blank through drift 200, form crooked calabash with bar-shaped blank along the shaping chamber extrusion, insert bar-shaped blank in the middle of the less part of diameter through the tip of drift 200 simultaneously, tentatively process bar-shaped blank into the tube-shape that has the blind hole, this blind hole is located the elbow one side that is close to the feeding chamber, and the one side of keeping away from the feeding chamber still is solid, treats that the whole elbow forges and presses the shaping back and processes the hole of opposite side again through later stage machining. The process steps of subsequent machining are saved, and the machining cost is reduced.

Further, the molding machine further includes: a base (not shown), an upper plate (not shown) and a driver (not shown). The lower mold 110 is fixed to the base. The upper die 120 is fixed to the upper plate, which is movable relative to the base. The punch 200 is mounted on the driver.

The base, upper plate and driver described above constitute the main parts of the forming machine, and in this embodiment, the forming machine is preferably a multi-directional swaging machine or a three-way forming machine.

A method of forming a bend, characterized by a method of forming a bend by the forming apparatus as claimed in any one of the above, the forming method comprising:

s100, blanking: manufacturing a bent pipe blank through a bar stock;

the method comprises the steps of cutting metal bars with required specifications into sections on a sawing machine according to required lengths, using the bars with certain sizes corresponding to high-pressure elbows of various specifications as blanks, and using the bars with the same diameters for 45-degree elbows and 90-degree elbows of the same specification, wherein the specifications of the high-pressure elbows which can be manufactured by the method are 0.5-2 inches.

the blank is heated by a medium-frequency induction heater, the blank is arranged into two rows and is heated simultaneously, two blanks are heated at each time, the power of an induction coil is adjusted to 20-100 KW by the medium-frequency induction heater through a power supply, the blank is continuously fed from a material pusher end of the medium-frequency induction heater, the material pusher pushes the blank to move in an inductor of a medium-frequency furnace according to the frequency of 2-4 blanks per minute, the blank is heated to 950-980 ℃, and the heated blank is continuously pushed out of a hearth.

S300, forming: the heated blank is placed into a feeding cavity of a lower die, 1 high-temperature blank is placed in each of two cavities of the die, positioning pins are placed into lower grooves of the lower die, an upper die is buckled on the lower die, a driver drives punches to move towards the blank direction from a die inlet, the punches on two sides are driven to form closed spaces with the upper die and the lower die respectively, single-time synchronous hot extrusion molding of double-piece high-pressure elbows is realized, after the punches are moved to preset positions (elbow shape molding according to design requirements and positions close to the primary processing molding of inner holes on one side of the feeding cavity), the upper die is opened, the driver drives the punches to return, and semi-finished workpieces are taken out.

cleaning oxide skin on the surface of a high-pressure elbow blank by adopting special acid liquor for copper alloy, wherein the formula of the acid liquor is 5% of HNO3+ 15% of H2SO4+ 80% of H2O (volume ratio), putting the blank into a special cleaning tool, then putting the blank into the acid liquor integrally, requiring the acid liquor to completely submerge a pipe fitting, soaking the pipe fitting in the acid liquor for 5min, and prolonging the soaking time by taking 5min as a unit until the oxide skin on the surface of the blank is completely removed.

S500, machining: machining according to design requirements, wherein the machining comprises machining of an inner hole of a workpiece, and all sizes and surface roughness of the workpiece meet the design requirements;

The outer surface of the high-pressure elbow pipe fitting is polished according to the requirement of the surface roughness of the drawing, an electric angle grinder is adopted to remove the local defects of the pipe fitting, and the outer surface is polished to ensure the uniform and smooth surface.

The surface of the high-pressure elbow is subjected to sand blasting by adopting 120-mesh brown corundum, and the pipe fitting is fully sprayed by using a sand blasting machine during the sand blasting, so that the surface of the pipe fitting is smooth, clean, uniform in gloss and free of stains.

The molding method will be described below with specific examples.

Example 1:

the invention is applied to the forming of the EEMUA234 standard 1-inch 90-degree high-pressure elbow, and the material is CuNi90/10 alloy, which comprises the following specific steps:

blanking: the cutting length L of CuNi90/10 bar stock with the diameter of 40 specification is 78 mm/piece, the weight is 0.88 kg/piece, and the reduction is 24.1% compared with the die forging process of 1.16 kg/piece.

Heating: the power of the medium-frequency induction heater is adjusted to 40KW by a power supply, the material pushing frequency is 2 pieces/30 seconds, the tube blank is continuously put into the material pusher, and the heating temperature is 950-980 ℃.

Molding: and simultaneously taking out two high-temperature blanks and respectively placing the two high-temperature blanks into a left forming cavity and a right forming cavity of the lower die, operating the press to close the upper die and the lower die, and extruding the blanks by the left cylinder punch and the right cylinder punch in opposite motion to form the two copper-nickel alloy high-pressure elbow blanks in a single forming process.

Acid washing: and cleaning the oxide skin on the surface of the high-pressure elbow blank by using the special acid liquor for the copper alloy, wherein the acid liquor completely submerges the pipe fitting, and the soaking time is 5 min.

Machining: and machining the inner hole of the blank according to the drawing requirements.

Polishing: an electric angle grinder is adopted to remove local defects of the pipe fitting, and the outer surface is polished to ensure the surface to be uniform and smooth.

Sand blasting: the surface of the high-pressure elbow is subjected to sand blasting by adopting 120-mesh brown corundum, so that the surface of the pipe fitting is smooth, clean, uniform in gloss and free of stains.

Example 2:

the invention is applied to the forming of EEMUA234 standard 2-inch 45-degree high-pressure elbows, and the material is CuNi90/10 alloy, which specifically comprises the following steps:

blanking: the cutting length L of CuNi90/10 bar stock with the diameter of 70 specification is 97mm per piece, the weight is 3.34kg per piece, and the reduction is 22.1% compared with 4.29kg per piece in the die forging process.

Heating: the power of the medium frequency induction heater is adjusted to 60KW by a power supply, the material pushing frequency is 2 pieces/40 seconds, the tube blank is continuously put into the material pusher, and the heating temperature is 950-980 ℃.

Molding: and simultaneously taking out two high-temperature blanks and respectively placing the two high-temperature blanks into the left forming cavity and the right forming cavity of the lower die, operating the press to close the upper die and the lower die, and performing opposite motion on the left cylinder punch and the right cylinder punch to extrude the bars for forming so as to realize single-forming of two copper-nickel alloy high-pressure elbow blanks.

Polishing: an electric angle grinder is adopted to remove local defects of the pipe fitting, and the outer surface is polished to ensure the surface to be even and smooth.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1. a kind of forming equipment of elbow, is characterized in that, comprises:

The mold is provided with a cavity, the cavity includes a feed cavity and a molding cavity, the feed cavity is provided with an inlet on the side wall of the mold, and the feed cavity extends to the inside of the mold and is connected to the mold. The forming cavity is connected, and the forming cavity is in a curved shape; the mold comprises:

a lower mold, two opposite lower mold cavities are arranged on both sides of the lower mold;

Upper mold, two opposite upper mold cavities are arranged on both sides of the upper mold, the upper mold is fastened on the lower mold, each of the lower mold cavity and a corresponding upper mold cavity Relatively fastened to form an integral said cavity;

Forming machines, including:

A punch is provided on both sides of the mold corresponding to each of the cavity, and the punch can move back and forth relative to the feed cavity.

2. The bending device according to claim 1, characterized in that,

The molding cavity includes two straight parts and one curved part, and the curved part is arranged between the two straight parts.

3. The device for forming an elbow according to claim 2, characterized in that,

The included angle of the axes between the two through portions is 90° or 135°.

4. The bending device according to claim 3, characterized in that,

The diameter near the two ends of the molding cavity is larger than the diameter of the middle part.

5. The elbow forming equipment according to claim 1, characterized in that,

A positioning structure is provided on the mold, and the positioning structure includes:

At least two lower grooves are arranged on the surface of the lower cavity opening of the lower mold, and the two lower grooves are arranged in mutually perpendicular directions;

At least two upper grooves are provided on the surface of the upper cavity opening of the upper mold, and the two upper grooves are arranged in mutually perpendicular directions;

When the upper mold is fastened with the lower mold, each lower groove is respectively fastened with a corresponding upper groove to form a positioning hole;

A positioning pin, one of the positioning pins is arranged in each of the positioning holes.

6. The elbow forming equipment according to claim 5, characterized in that,

A first positioning hole is provided on both sides along the width direction of the mold, and the two first positioning holes are coaxially arranged;

A second positioning hole is provided on both sides along the length direction of the mold, and the two second positioning holes are symmetrically arranged with respect to the center line in the width direction.

7. The elbow forming equipment according to claim 1, characterized in that,

The punch is in the shape of a stepped shaft, and the diameter of the end close to the die is smaller than the diameter of the end away from the die.

8. The elbow forming equipment according to claim 1, wherein the forming machine further comprises:

a base, on which the lower die is fixed;

an upper plate, the upper mold is fixed on the upper plate, and the upper plate can move relative to the base;

a driver on which the punch is mounted.

9. A method for forming an elbow, characterized in that, a method for forming an elbow by the forming equipment according to any one of claims 1 to 8, the forming method comprising:

S100, blanking: make a billet of a bent pipe from a bar;

S200, heating the blank, placing the blank into a heating device, and heating to 950°C-980°C;

S300. Forming: put the heated blank into the feed cavity of the lower mold, put the positioning pins into the lower grooves of the lower mold, fasten the upper mold to the lower mold, and press the punch from the mold inlet to the blank After moving to the preset position, the upper die is opened, the driver drives the punch back, and the semi-finished workpiece is taken out;

S400, pickling: cleaning the oxide scale on the surface of the semi-finished workpiece;

S500, machining: machining according to the design requirements, including machining the inner hole of the workpiece;

S600, surface treatment, including grinding and sandblasting the surface of the workpiece to meet the design requirements.

10. The method for forming an elbow according to claim 9, wherein,

At least in steps S200 and S300, the operation of the two blanks is performed simultaneously.