CN114951540A - Elbow forming equipment and method - Google Patents

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

A kind of elbow forming equipment and forming method

technical field

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

Background technique

Copper-nickel alloy is a material with excellent resistance to seawater corrosion and marine biofouling. It also has excellent cold and hot processing properties and welding properties, and is widely used in the fields of ships and marine engineering.

Copper-nickel alloy high pressure elbow is a kind of forged elbow, including plug welding (SW), brazing (CB), thread (NPT) and other forms. For example, the publication number is CN209393910U Chinese utility model patent, which discloses a A space corner elbow die, including an upper die and a lower die, the upper part of the upper die is fixedly connected to the forging press through an upper connecting plate, the lower end of the upper die is provided with an upper forging surface, and the upper forging surface includes A horizontal first forging surface and an obliquely upward second forging surface, the lower die is provided with a lower forging surface, and the lower forging surface includes a third forging surface that cooperates with the first forging surface and a second forging surface that cooperates with the second forging surface. The upper forging surface is provided with a curved upper semicircular groove that turns from the first forging surface to the second forging surface, and the lower forging surface is provided with a curved upper semicircular groove matching the upper semicircular groove. The curved lower semicircular groove from the third forging surface to the fourth forging surface; through this die, the bending and pressing method can be used to prepare a space corner elbow. The shape and inner hole size of the elbow are close to the finished size, and only the welding groove at the end needs to be processed. , which can save the cost of raw materials, heat treatment, and machining. Its traditional process adopts integral solid die forging, specifically, using the movement of the upper die and the lower die to form a closed space on the press, so that the metal fills the interior to obtain the shape of the blank. This method not only has a low material utilization rate (deficient). 50%), and the forming process needs to go through a series of steps such as pier thickening - die forging - trimming, etc., and the production efficiency is low.

SUMMARY OF THE INVENTION

In view of this, the present invention aims to provide an elbow forming equipment, which adopts a convex punch to form a blank with a hole, and solves the problems of low production efficiency, material waste, and low material utilization rate.

In order to achieve the above object, the technical scheme of the present invention is achieved in this way:

A device for forming an elbow, comprising: a mold with a cavity, the cavity includes a feeding cavity and a molding cavity, the feeding cavity is provided with an inlet on the side wall of the mold, and the feeding cavity is The cavity extends to the inside of the mold and communicates with the molding cavity, and the molding cavity is curved; the mold includes:

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.

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

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

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

Further, 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.

Further, 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.

Further, 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.

Further, the molding machine also includes:

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.

A method for forming an elbow, characterized in that, a method for forming an elbow by the above-mentioned forming equipment, 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.

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

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

The advantage of this technical solution is that the produced high-pressure elbow product meets the requirements of various technical indicators, effectively solves the problems of low material utilization, high cost and low efficiency of the existing high-pressure elbow forming method, and can achieve 0.5-inch to 2-inch , 45° and 90° forming of copper-nickel alloy high-pressure elbows, improve material utilization and forming efficiency, improve the quality stability and dimensional accuracy of high-pressure elbow blanks, reduce defects such as black skin and inclusions, and reduce cost.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

FIG. 1 is an exploded view of an elbow 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 numbers:

100-mold, 110-lower mold, 111-cavity, 1111-feed cavity, 1112-molding cavity, 112-positioning hole, 1121-first positioning hole, 1122-second positioning hole, 120-upper mold, 200 -shower.

Detailed ways

It should be noted that the embodiments of the present invention and the features of the embodiments may be combined with each other under the condition of no conflict.

The descriptions involving "first", "second", "upper", "lower", etc. in the present invention are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implying the indicated technology number of features. Thus, features defined as "first", "second", "upper", "lower" may expressly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the technical solutions between the embodiments can be combined, it is within the protection scope of the present invention. Inside.

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

As shown in FIG. 1 , an elbow forming equipment includes: a mold 100 and a forming machine. As shown in FIG. 2, the mold 100 is provided with a cavity 111, the cavity 111 includes a feed cavity 1111 and a molding cavity 1112, the feed cavity 1111 is provided with an inlet on the side wall of the mold 100, and the The feeding cavity 1111 extends toward the inside of the mold 100 and communicates with the molding cavity 1112 , and the molding cavity 1112 is curved; the mold 100 includes a lower mold 110 and an upper mold 120 . Two opposite lower mold cavities are arranged on both sides of the lower mold 110; two opposite upper mold cavities are arranged on both sides of the upper mold, and the upper mold 120 is fastened on the lower mold 110, Each of the lower mold cavities and the corresponding one of the upper mold cavities are relatively fastened to form an integral mold cavity 111 . The molding machine includes a punch 200 , one of which is provided on both sides of the mold 100 corresponding to each of the cavity 111 , and the punch 200 can reciprocate relative to the feed cavity 1111 .

Two blanks can be put into the above-mentioned mold 100 at the same time, and two elbows can be simultaneously produced by two punches 200 respectively. The produced high-pressure elbow products meet the requirements of various technical indicators, effectively solving the problems of low material utilization, high cost and low efficiency of the existing high-pressure elbow forming methods, and can achieve 0.5-inch to 2-inch, 45° and 90° ° The forming of high-pressure copper-nickel alloy elbows improves material utilization and forming efficiency, improves the quality stability and dimensional accuracy of high-pressure elbow blanks, reduces defects such as black skin and inclusions, and reduces costs.

Specifically, the molding cavity 1112 includes two straight parts and one curved part, and the curved part is disposed between the two straight parts.

A curved product is produced by a molding cavity 1112 having a curved portion disposed between two straight portions.

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

The included angle between the two straight parts of the bent product can be greater than 0° and less than 180°, and the bent pipe product between 90° and 180° is easy to manufacture. In this embodiment, the commonly used 90° and 135° are preferred. angle.

Further, the diameter near the two ends of the molding cavity 1112 is larger than the diameter of the middle part.

The forming cavity 1112 with the above structure can directly manufacture the ends of the internal thread parts at both ends of the elbow, and it is also convenient to make the two ends into a hexagonal shape by machining and other methods in the later stage, without forging and then by welding or machining. Processing the outer surface of the elbow reduces the processing steps and reduces the processing cost.

Further, a positioning structure is provided on the mold, and the positioning structure includes: a lower groove, an upper groove and a positioning pin (not shown in the figure). At least two mutually perpendicular lower grooves are provided on the surface of the lower cavity opening of the lower mold. At least two mutually perpendicular upper grooves are provided on the surface of the upper cavity opening of the upper mold. When the upper mold and the lower mold are fastened together, each lower groove is fastened with a corresponding upper groove to form a positioning hole 112 . One of the positioning pins is provided in each of the positioning holes.

The upper die 120 and the lower die 110 are accurately matched by inserting locating pins into at least two mutually perpendicular locating holes, and the corresponding upper and lower cavities will not be misaligned, thereby ensuring product quality.

As a preferred manner, one first positioning hole 1121 is respectively provided on both sides of the mold 100 in the width direction, and the two first positioning holes 1121 are coaxially provided. A second positioning hole 1122 is provided on both sides along the length direction of the mold 100 , and the two second positioning holes 1122 are symmetrically arranged with respect to the center line in the width direction.

Two positioning holes 112 are respectively provided in the two directions of length and width, and one of them is on the same straight line, and the other is symmetrical with the center line, which further ensures the precise fit of the upper die 120 and the lower die 110 .

Further, the punch 200 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.

When the blank is extruded by the punch 200, the rod-shaped blank is extruded along the molding cavity to form a curved rod-shaped, and at the same time, the smaller diameter part of the end of the punch 200 is inserted into the middle of the rod-shaped blank, and the rod-shaped blank is preliminarily processed into A cylindrical shape with a blind hole, the blind hole is located on the side of the elbow close to the feed cavity, and the side away from the feed cavity is still solid. The inner hole is processed. The process steps of subsequent mechanical processing are saved, and the processing cost is reduced.

Further, the forming machine further comprises: a base (not shown in the figure), an upper plate (not shown in the figure) and a driver (not shown in the figure). The lower mold 110 is fixed on the base. The upper mold 120 is fixed on the upper plate, and the upper plate can move relative to the base. The punch 200 is mounted on the driver.

The above-mentioned base, upper plate and driver constitute the main part of the forming machine. In this embodiment, the preferred forming machine is a multi-directional die forging machine or a three-way forming machine.

A method for forming an elbow, characterized in that, a method for forming an elbow by the above-mentioned forming equipment, the forming method comprising:

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

Cut the metal bar of the required specification into sections on the sawing machine according to the required length. Each specification of high-pressure elbow corresponds to a bar of a certain size as a blank. The 45° and 90° elbows of the same specification use the same diameter bar. The specification of the high-pressure elbow that can be produced by the invention is 0.5 inches to 2 inches.

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

The intermediate frequency induction heater is used to heat the blanks. The blanks are arranged in two rows and heated at the same time. Two pieces are heated at a time. The intermediate frequency induction heater adjusts the power of the induction coil to 20-100KW through the power supply, and the blanks continue from the pusher end of the intermediate frequency induction heater. For feeding, the pusher pushes the billet to move in the intermediate frequency furnace inductor at a frequency of 2 to 4 pieces/min. The billet is heated to 950℃～980℃, and the heated billet is continuously pushed out of the furnace.

S300. Forming: put the heated blank into the feed cavity of the lower mold, place one high-temperature blank in each of the two cavities of the mold, and put the positioning pins into the lower grooves of the lower mold to place The upper die is fastened on the lower die, and the driver drives the punch to move from the die inlet to the direction of the blank, and drives the punches on both sides to form a closed space with the upper and lower dies respectively, so as to realize the synchronous hot extrusion forming of a single two-piece high-pressure elbow, and move to the pre-extrusion. After setting the position (the shape of the elbow is formed according to the design requirements, and the position near the inner hole on the side of the feed cavity is initially processed and formed), 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;

The oxide skin on the surface of the high-pressure elbow blank is cleaned with a special acid solution for copper alloys. The acid solution is 5%HNO3+15%H2SO4+80%H2O (volume ratio). Put the blank into the special cleaning tool, and then put it into the whole In the acid solution, it is required that the acid solution can completely submerge the pipe fittings, and soak in the pickling solution for 5 minutes. When the oxide scale on the surface of the blank is not completely removed, the soaking time is extended by 5 minutes until the surface oxide scale is completely washed away.

S500. Machining: Machining is carried out according to the design requirements, including machining the inner hole of the workpiece, and the dimensions and surface roughness of the workpiece meet the design requirements;

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

Grind the outer surface of the high-pressure elbow pipe fittings according to the surface roughness requirements of the drawings, use an electric angle grinder to remove local defects of the pipe fittings, and polish the outer surface to ensure a uniform and smooth surface.

Use 120-mesh brown corundum to sandblast the surface of the high-pressure elbow, and use a sandblasting machine to fully spray the pipe fittings to make the surface of the pipe fittings smooth, clean, evenly glossy, and free of stains.

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

Hereinafter, the above-mentioned molding method will be described with specific examples.

Example 1:

The present invention has been applied to the forming of EEMUA234 standard 1-inch 90° high pressure elbow, and the material is CuNi90/10 alloy, specifically:

Cutting material: use φ40 specification CuNi90/10 bar, saw cutting length L=78mm/piece, weight 0.88kg/piece, which is 24.1% less than 1.16kg/piece in die forging process.

Heating: The power of the intermediate frequency induction heater is adjusted to 40KW through the power supply, the pushing frequency is 2 pieces/30 seconds, the tube blank is continuously placed at the end of the pusher, and the heating temperature is 950℃～980℃.

Forming: Take out two pieces of high-temperature blanks and place them in the left and right forming cavities of the lower die at the same time. Operate the press to close the upper and lower dies, and the left and right cylinder punches move towards each other to extrude the bar to form two pieces of copper-nickel at a time. For the alloy high pressure elbow blank, because the punch is convex, it penetrates into the material to obtain a blank with a hole, and its size meets the machining requirements.

Pickling: The oxide skin on the surface of the high-pressure elbow blank is cleaned with a special acid solution for copper alloys. The acid solution completely submerges the pipe fittings, and the soaking time is 5 minutes.

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

Grinding: Use an electric angle grinder to remove local defects of the pipe fittings, and polish the outer surface to ensure a uniform and smooth surface.

Sandblasting: 120-mesh brown corundum is used to blast the surface of the high-pressure elbow, so that the surface of the pipe fittings is smooth, clean, uniform in luster, and free of stains.

Example 2:

The invention has been applied to the forming of EEMUA234 standard 2-inch 45° high-pressure elbows, and the material is CuNi90/10 alloy, specifically:

Cutting material: use φ70 specification CuNi90/10 bar, sawing machine saw cutting length L=97mm/piece, weight 3.34kg/piece, which is 22.1% less than 4.29kg/piece in die forging process.

Heating: The power of the intermediate frequency induction heater is adjusted to 60KW through the power supply, the pushing frequency is 2 pieces/40 seconds, the tube blank is continuously placed at the end of the pusher, and the heating temperature is 950℃～980℃.

Forming: Take out two pieces of high-temperature blanks and place them in the left and right forming cavities of the lower die at the same time. Operate the press to close the upper and lower dies, and the left and right cylinder punches move towards each other to extrude the bar to form two pieces of copper-nickel at a time. For the alloy high pressure elbow blank, because the punch is convex, it penetrates into the material to obtain a blank with a hole, and its size meets the machining requirements.

Pickling: The oxide skin on the surface of the high-pressure elbow blank is cleaned with a special acid solution for copper alloys. The acid solution completely submerges the pipe fittings, and the soaking time is 5 minutes.

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

Grinding: Use an electric angle grinder to remove local defects of the pipe fittings, and polish the outer surface to ensure a uniform and smooth surface.

Sandblasting: 120-mesh brown corundum is used to blast the surface of the high-pressure elbow, so that the surface of the pipe fittings is smooth, clean, uniform in luster, and free of stains.

Other embodiments of the invention will readily occur to those skilled in the art upon 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 that follow the general principles of the invention and include common knowledge or conventional techniques in the art not disclosed by this disclosure . The specification and examples are to be regarded as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

It should be understood that the present invention is not limited to the precise structures described above and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims (10)

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.

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