CN101693262A - Method for preparing pipe bending part by adopting eccentric extrusion forming - Google Patents

Abstract

A method for preparing pipe bending parts by eccentric extrusion molding, in which a metal billet is extruded by an eccentric extrusion molding device, the eccentric extrusion molding device includes a mold forming part, a mold fixing part and a pressurizing part; the mold forming part includes a concave Die, punch, mandrel and extrusion ring, the discharge end of the die has a taper, the mold forming part is an eccentric structure; the fixed part of the mold includes the lower die, the fixed ring and the upper die, and the center of the lower die is equipped with a discharge The pressure part includes a pressure plate, a guide post and a guide sleeve, and the pressure plate can move up and down along the guide post through the guide sleeve. The advantages of the present invention are: in the extrusion molding device for pipe bending parts, the concave die and punch of the mold forming part adopt an eccentric structure design, and the pipe bending parts are extruded and prepared by controlling the eccentricity. Simple, the pipe bending parts have uniform wall thickness, no wrinkle, no distortion in cross section, reliable quality, and wide application prospects.

Description

A method for preparing pipe bending parts by eccentric extrusion

(1) Technical field

The invention relates to the preparation technology of pipe bending parts, in particular to a method for preparing pipe bending parts by eccentric extrusion.

(2) Background technology

As the application fields of pipe bending parts become more and more extensive, pipe bending parts are widely used in aerospace, automobile, shipbuilding and other industries, and the requirements for bending quality and forming process of pipes are getting higher and higher. There are defects such as thinning and cracking of the outer wall, thickening, wrinkling and cross-sectional distortion of the inner wall in the parts produced by the traditional pipe bending method.

(3) Contents of the invention

The object of the present invention is to solve the above existing problems and provide a method for preparing pipe bending parts by eccentric extrusion molding with reasonable structure, simple process, reliable quality, uniform wall thickness, no wrinkle, and no distortion in cross section.

Technical scheme of the present invention:

A method for preparing pipe bending parts by eccentric extrusion molding. Metal blanks are extruded by an eccentric extrusion molding device. The eccentric extrusion molding device includes a mold forming part, a mold fixing part and a pressurizing part; the mold forming part includes a concave Die, punch, mandrel and extrusion ring. The discharge end of the die has a taper. The punch is composed of two cylinders and an end plate. The mold forming part is an eccentric structure, that is, the center line of the die and the punch. There is an eccentric distance between the center line of the mandrel; the fixed part of the mold includes a lower template, a fixed ring and an upper template. There is a discharge port in the center of the formwork, the mold forming part is located in the fixed ring, the upper end of the mandrel is fixed in the groove of the upper formwork through a beam, and the lower end of the mandrel is located at the conical exit of the die; the pressurizing part includes a pressurizing plate, Guide post and guide sleeve, the pressure plate is fixed with the end plate of the punch through pins and screws, the lower end of the guide post is fixed with the lower template and the fixing ring, the guide sleeve is fixed with the pressure plate, the guide post passes through the guide sleeve and is connected with the guide The sleeve is a dynamic fit, and the pressure plate can move up and down along the guide post through the guide sleeve. The technical parameters of the extrusion molding of the metal billet are the billet temperature from room temperature to 400° C., and the pressure of the hydraulic press to 100 t.

The taper of the discharge end of the die is 45°-60°.

The eccentricity is 0˜d/2, and d is the diameter of the mandrel.

Working principle of the present invention:

The present invention extrudes the metal billet through an eccentric extrusion molding device. When the hydraulic press acts on the punch through the pressure plate, the billet moves downward under the action of the punch. The use of eccentric structure design leads to unbalanced flow of metal at the conical outlet of the die, so that the pipe is bent and deformed, and then the bent pipe fittings we need are obtained. The metal flow is controlled by the speed difference generated by the eccentric structure, and different bending angles and shapes of pipe bending parts can be formed.

The advantages of the present invention are: in the extrusion molding device for pipe bending parts, the concave die and punch of the mold forming part adopt an eccentric structure design, and the pipe bending parts are extruded and prepared by controlling the eccentricity. The utility model has the advantages of simple, uniform wall thickness, no wrinkle, no distortion of the cross section, reliable quality, and wide application prospects.

(4) Description of drawings

Figure 1 is a schematic diagram of the structure of an eccentric extrusion molding device.

Figure 2 is a schematic top view of the eccentric extrusion molding device.

In the figure: 1. Die 2. Punch 3. Mandrel 4. Extrusion ring 5. Lower template 6. Fixing ring 7. Upper template 8-1, 8-2. Pin 9-1, 9-2. Screw 10. Outlet 11. Beam 12. Pressure plate 13. Guide column 14. Guide sleeve 15. Pin 16. Screw 17. Blank

(5) Specific implementation methods

Example:

A method for preparing pipe bending parts by eccentric extrusion molding. Metal blanks are extruded by an eccentric extrusion molding device. The eccentric extrusion molding device includes a mold forming part, a mold fixing part and a pressurizing part; the mold forming part includes a concave Die 1, punch 2, mandrel 3 and extrusion ring 4, the discharge end of die 1 has a taper, punch 2 is composed of two cylinders and an end plate, and the molding part of the mold is an eccentric structure, that is, the die 1 and the center line of the punch 2 and the center line of the mandrel 3 are provided with an eccentric distance; the fixed part of the mold includes the lower template 5, the fixing ring 6 and the upper template 7, and the fixing ring 6 is located between the lower template 5 and the upper template 7 The lower template 5 and the upper template 7 are respectively fixed by pins 8-1, 8-2 and screws 9-1, 9-2. The center of the lower template 5 is provided with a discharge port 10, and the molding part of the mold is located in the fixed ring 6. , the upper end of the mandrel 3 is fixed in the groove of the upper template 7 through the beam 11, and the lower end of the mandrel 3 is located at the tapered exit of the die 1; The plate 12 is fixed to the end plate of the punch 2 through pins 15 and screws 16, the lower end of the guide post 13 is fixed to the lower template 5 and the fixing ring 6, the guide sleeve 14 is fixed to the pressure plate 12, and the guide post 13 passes through the guide sleeve 14 And with the guide sleeve 14 for dynamic cooperation, the pressure plate 12 can move up and down along the guide post 13 through the guide sleeve 14 . The blank 17 is placed in the die 1 , and the blank 17 is pressed by the press through the pressure plate 12 , the punch 2 and the extrusion ring 4 .

In this embodiment, the inner diameter of the elbow is 20mm, the wall thickness is 3mm, the bending radius is 60mm, the blank is 5052 aluminum alloy, the taper of the discharge end of the die is 45°, and the eccentricity of the eccentric structure of the die and the punch is 10mm. The pressure of the hydraulic press is 100t, there is a middle hole in the center of the billet, and the temperature is room temperature.

The working procedure of this embodiment is: place the die 1 in the fixed ring 6, then put the blank 17 into the die 1, the upper end of the mandrel 3 is seated in the groove of the upper template 7 through the beam 11, and the mandrel 3 The lower end passes through the extrusion ring 4 and the blank 17 is located at the outlet end of the die 1; the pressure plate 12 accepts the pressure of the press, and acts on the extrusion ring 4 through the punch 2. Due to the design of the eccentric structure, the same Under the extrusion force of the billet 17, the metal flow on the side with more volume is faster than the side with less volume, so the imbalance of metal flow at the exit is formed. This imbalance of metal flow makes the pipe bend, and we obtain The required pipe bends.

The pipe bending piece prepared in this embodiment has uniform wall thickness, no wrinkle, no distortion in cross section, and good use effect.

Claims (4)

1. method that adopts eccentric extrusion forming to prepare pipe bending part is characterized in that: with the metal stock extrusion modling, the eccentric extrusion forming device comprises mould molding part, mould fixing part and pressures partially by the eccentric extrusion forming device; Mould molding partly comprises die, punch, plug and extrusion ring, the discharge end of die has tapering, punch constitutes one by two cylinders and end plate, and mould molding partly is an eccentric structure, promptly is provided with eccentric throw between the center line center line of die and punch and the plug center line; Mould fixing part comprises lower bolster, retainer plate and cope match-plate pattern, retainer plate is fixed by pin and screw and lower bolster and cope match-plate pattern between lower bolster and cope match-plate pattern and respectively, the center of lower bolster is provided with discharging opening, mould molding partly is positioned at retainer plate, the plug upper end is fixed in the groove of cope match-plate pattern by crossbeam, and the plug lower end is positioned at die conical outlet place; Pressures partially comprises increased pressure board, guide pillars and bushes, increased pressure board is fixed by the end plate of pin and screw and punch, and the lower end of guide pillar and lower bolster and retainer plate are fixed, and guide pin bushing and increased pressure board are fixed, guide pillar pass guide pin bushing and with guide pin bushing for movingly, increased pressure board can move up and down along guide pillar by guide pin bushing.

2. prepare the method for pipe bending part according to the described employing eccentric extrusion forming of claim 1, it is characterized in that: the technological parameter of described metal stock extrusion modling is that the pressure of blank temperature room temperature～400 ℃, hydraulic press is 100t.

3. prepare the method for pipe bending part according to the described employing eccentric extrusion forming of claim 1, it is characterized in that: the tapering of described die discharge end is 45 °～60 °.

4. prepare the method for pipe bending part according to the described employing eccentric extrusion forming of claim 1, it is characterized in that: described eccentric throw is 0～d/2, and d is the diameter of plug.

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