CN102107230B - Shaping device for preparing bent tube by virtue of differential-velocity extrusion of dual male dies - Google Patents

Abstract

A forming device for preparing pipe bending parts by differential extrusion with double convex dies. The extrusion forming device includes a mold forming part, a mold fixing part and a guide part; the mold forming part includes a die, a punch, a mandrel and an extrusion block; The mold fixing part includes a base fixing plate, a support seat, a slide plate, and a die fixing plate; the guiding part of the mold includes a guide column, a guide sleeve, a top plate, and a base fixing plate. The invention has the advantages that: the mold adopts horizontal extrusion, which increases the length range of extruded bent pipe fittings. The concave mold and the concave mold fixing plate of the mold forming part are all in the form of blocks, which is convenient for the removal of the workpiece and the re-extrusion of the blank after the extrusion is completed. The mandrel fixing plate is guided by the guide rod and the dovetail groove, and is ejected manually by the screw rod. The center line of the die, the punch and the mandrel are in a straight line, which is easy to assemble and adjust. By changing the extrusion speed of the punches A and B, the extrusion speed difference between the punches A and B is manufactured, and the difference is used to prepare the pipe bending parts. The device has a reasonable structure, simple process, and the wall thickness of the pipe bending parts Uniform and wrinkle-free, no distortion in cross-section, reliable quality, and wide application prospects.

Description

A forming device for preparing pipe bending parts by differential extrusion of double convex die

technical field

The invention relates to the preparation technology of medium and thin-walled pipe bending parts, in particular to a device that adopts double-convex dies to extrude pipes that are arbitrarily curved on a plane.

Background technique

With the development of forming equipment and manufacturing technology, pipe bending parts with complex shapes appear more and more frequently in industrial fields, especially in high-tech industrial fields, such as aircraft, ships, automobiles, gas pipelines, and some stand. Because the use of curved pipe fittings instead of the original wire or plastic pipes can reduce weight and improve durability. With the widespread application of pipe bending parts, people have higher and higher requirements on the bending quality and forming process of pipe materials. Most of the curved pipe fittings produced by traditional methods such as push bending and rolling bending have some defects, such as the reduction of the outer wall. Defects such as thinness and cracking, thickening of the inner wall, wrinkling, and cross-sectional distortion, and the bending angle and direction of the pipe fittings are limited, and arbitrary bending cannot be achieved.

Contents of the invention

The invention provides a double-convex differential speed extrusion molding device capable of bending in different directions in the same plane, the range of bending angle is 90°-180°, and the bending angle is controlled.

Technical scheme of the present invention is:

A forming device for preparing pipe bending parts by adopting double-convex differential extrusion, characterized in that: the extrusion forming device includes a mold forming part, a mold fixing part and a guide part; the mold forming part includes a die, a punch, and a mandrel And the extrusion block, the upper part of the concave mold cavity is cylindrical, the discharge end is a conical frustum, the punch is semi-circular (see Figure 5-f), the centerline of the concave mold, the centerline of the punch, the centerline of the billet and the mandrel The center line coincides, and the billet is concentric; the fixed part of the mold includes the base fixed plate, the support seat, the slide plate, and the die set plate. Die connection, half of the die fixing plate is fixed on the base fixing plate, and the base fixing plate is fixed on the support plate; the center of the base fixing plate is provided with a discharge port, the mold forming part is located in the die fixing plate, and the mandrel is embedded in the In the slide plate, the lower end of the mandrel is located at the conical exit of the die; the guide part includes a guide column, a guide sleeve, a top plate, a base fixing plate, and a slide plate. , to ensure the accurate sliding of the skateboard.

The truncated cone at the discharge end of the concave mold has a taper of 45° to 60°, a height h of the truncated cone of 15mm to 30mm, and the height of the extrusion cylinder is the height of the cylinder in the concave mold cavity H≥50mm.

The wall thickness of the curved pipe fittings is 3mm≥t≥0.5mm; the bending angle is 180°≥α≥90°.

Set the height of punch A to H _A , the height of punch B to H _B , the height of the blank to H, the speed of punch A to V _A , and the speed of punch B to V _B , the following must be satisfied:

When V _A >V _B ,

When V _B >V _A ,

The speed difference between punch A and punch B multiplied by the time for the fast punch to squeeze the entire billet must be less than the height of the slow punch.

The concave mold and the concave mold fixing plate of the mold forming part are all in the form of blocks, which is convenient for taking out the workpiece and re-extruding the blank after the extrusion is completed.

Working principle of the present invention:

In the present invention, the metal billet is formed by a double-convex differential extrusion molding device, and the extrusion force is applied to the punches A and B respectively through the hydraulic device, and the punches A and B obtain different pressures under the action of their respective extrusion forces. speed. The punches A and B move toward the billet to extrude the billet. Because the movement speeds of the punches A and B are different, the forces exerted by the punches A and B on the billet are also different, and the two ends of the billet that are in contact with the punches A and B are subjected to different forces, so the material flow speeds at both ends of the billet are also different. . There is a speed difference between the punches A and B, so that the blanks they act on produce an uneven speed field during the downward extrusion process. This uneven velocity field is manifested in the fact that the flow velocity of each particle is different when the material flows out, and the velocity difference of each material particle leads to the bending of the tube blank when it flows out. By controlling the unbalanced field of the metal material flow, that is, controlling the speed difference between the punch A and the punch B, it is possible to form pipe bends with arbitrary bends and different shapes in the same plane.

The invention has the advantages that: the mold adopts horizontal extrusion, which increases the length range of extruded bent pipe fittings. The concave mold and the concave mold fixing plate of the mold forming part are all in the form of blocks, which is convenient for the removal of the workpiece and the re-extrusion of the blank after the extrusion is completed. The mandrel fixing plate is guided by the guide rod and the dovetail groove, and is ejected manually by the screw rod. The center line of the die, the punch and the mandrel are in a straight line, which is easy to assemble and adjust. By changing the extrusion speed of the punches A and B, the extrusion speed difference between the punches A and B is manufactured, and the difference is used to prepare the pipe bending parts. The device has a reasonable structure, simple process, and the wall thickness of the pipe bending parts Uniform and wrinkle-free, no distortion in cross-section, reliable quality, and wide application prospects.

Description of drawings

Fig. 1 and Fig. 2 are schematic diagrams of the device structure of the dual-convex differential extrusion molding plane arbitrarily curved pipe fittings.

Fig. 3 and Fig. 4 are cross-sectional schematic diagrams of A-A of the device for forming a planar arbitrary bending pipe fitting by double-convex differential extrusion.

Figure 5 is a schematic diagram of a three-dimensional structure of a typical part.

In Figure 1-4: 1. Guide column 2. Base fixed plate 3. Die insert 1, 2 4. Blank 5. Extrusion block A, B 6. Die fixed plate 1, 2 7. Sliding plate 8. Guide Set-1 9. Guide column 10. Top plate 11. Punch A, B 12. Screw-1 13. Support seat 14. Screw 15. Screw fixing plate 16. Round pin-1 17. Screw-2 18. Hex nut 19 .Mandrel 20.Screw-3 21.Screw-3 22.Guide sleeve-2 23.Guide post 24.Screw-4 25.Screw-5 26.Round pin-2 27.Round pin-3

In Fig. 5: Fig. 5-a Die insert 1; Fig. 5-b Die insert 2; 5-c Combination diagram of die insert; 5-d Blank;

Figure 5-e extrusion block combination; Figure 5-f punch diagram; 5-g mandrel; Figure 5-h slide plate

Detailed ways

Example 1:

Double-convex differential extrusion forming device for preparing pipe bending parts. The extrusion forming device includes a mold forming part, a mold fixing part and a guide part; the mold forming part includes die inserts 1 and 2, a mandrel 19 and an extrusion block A and B, the die inserts 1 and 2 are respectively fixed on the die fixing plates 1 and 2 by screws 24 and pins 25, the punch is composed of two semicircular cylinders, the die is composed of die inserts, and the core The geometric center line of the shaft and the punch is on the same straight line after the mold is assembled; the fixed part of the mold includes the base fixing plate 2, the support seat 13, the slide plate 7, the die fixing plate 6, and the die fixing plate 6-2 has a dovetail groove , the slide plate 7 and the die fixing plate are sliding fit, the die fixing plate 6-2 is fixed on the base fixing plate 2 through the screw 21 and the pin 27, and the base fixing plate 2 is fixed on the support seat through the screw 17 and the pin 16 On 13, base fixed plate 2, support seat 13, slide plate 7, die fixed plate 6 during processing and manufacturing, the contact surface between them requires high flatness and parallelism, guarantees the accurate positioning and operation of mould. There are two forms of mold guides, namely dovetail grooves, guide pillars, and guide sleeves. The mandrel 19 is fixed on the slide plate 7, and the slide plate 7 makes the mandrel accurately enter the concave mold cavity through the sliding of the dovetail groove, the guide column 9 and the guide sleeve 8. The block type die fixing plates 6-1 and 6-2 are guided by guide posts 23 and guide sleeves 23, and are fastened by screws 24. Die inserts and die fixing plates are made into blocks to facilitate the storage of blanks and the removal of workpieces. The pressing part of the mold is the punch and the extrusion block. When the plunger of the hydraulic press carries the punch to run, the punch first enters the sliding plate of the fixed mandrel. There is a small gap between the guide column and the guide sleeve of the mold to ensure the accurate sliding of the punch. After the punch is in contact with the extrusion, the extrusion block extrudes the billet to cause plastic deformation.

In this embodiment, the inner diameter of the elbow is 20mm, the wall thickness is 3mm, the blank is 5052 aluminum alloy, the taper of the discharge end of the die is 59°, the radius of the spherical surface is 20mm, the pressure of the hydraulic press is 100t, and there is a central hole in the center of the blank. The temperature is room temperature.

The working procedure of this embodiment is: after the assembly mold is completed and fixed on the horizontal hydraulic press, the blank 4 is put into the die insert 3, the upper end of the mandrel 19 is fixed on the slide plate 7, and the lower end of the mandrel 19 passes through the extrusion The block 5 and the blank 4 are located at the outlet end of the die insert 3; the punches 11-A and 11-B undertake the loading of the hydraulic press, and act on the blank 4 through the extrusion blocks 5-A and 5-B. The horizontal hydraulic press acts on the punches 11-A and 11-B differently, so that the punches 11-A and 11-B obtain different extrusion speeds under different extrusion forces. The punches 11-A and 11-B move toward the billet to extrude the billet. Because the movement speeds of the punches A and B are different, the forces exerted by the punches A and B on the billet are also different, and the two ends of the billet that are in contact with the punches A and B are subjected to different forces, so the material flow speeds at both ends of the billet are also different. . There is a speed difference between the punches A and B, so that the blanks they act on produce an uneven speed field during the downward extrusion process. This uneven velocity field is manifested in the fact that the flow velocity of each particle is different when the material flows out, and the velocity difference of each material particle leads to the bending of the tube blank when it flows out. By controlling the unbalanced field of the metal material flow, that is, controlling the speed difference between the punch A and the punch B, the pipe is bent, so as to obtain the pipe bending parts we need.

The pipe bending piece prepared in this embodiment has uniform wall thickness, no wrinkle, no distortion in cross section, and has broad application prospects.

Claims (1)

1. a double-convex-mold differential pushes the shaped device for preparing pipe bending part, it is characterized in that: extrusion forming device comprises mould molding part, mould fixing part and targeting part; Mould molding partly comprises die, punch, mandrel and crushing block, and it is cylindrical that concave die cavity top is divided into, and discharge end is the frustum of a cone, and punch is semi-annular shape, die, and the center line of punch, blank center line overlap with the plug center line, and blank is material with one heart; Mould fixing part comprises base fixing plate, supporting seat, slide plate, die block, die block has dovetail groove, be slidably matched between slide plate and die block, die block is connected with die, half of die block is fixed on base fixing plate, and base fixing plate is fixed on gripper shoe; The center of base fixing plate is provided with discharging opening, and mould molding partly is positioned at die block, and mandrel is embedded in slide plate, and the plug lower end is positioned at die conical outlet place; Targeting part comprises lead, guide pin bushing, top board, base fixing plate, slide plate, and guide pin bushing is fixed in slide plate, joins for little gap cunning between lead and guide pin bushing; The height of setting punch A is H _A, the height of punch B is H _B, the height of blank is H, the speed of punch A is V _A, the speed of punch B is V _B, must satisfy:

V _A＞V _BThe time, $V_A-V_B<\frac{H_B\&times;V_A}{H};$

V _B＞V _AThe time, $V_B-V_A<\frac{H_A\&times;V_B}{H};$

The frustum of a cone of described die discharge end, tapering are 45 °～60 °, and frustum height h is 15mm～30mm, and the recipient height is columniform height H 〉=50mm in concave die cavity;

The device moulding bending pipe fitting wall thickness 3mm 〉=t of institute 〉=0.5mm; Angle of bend is 180 °＞α 〉=90 °;

Die, the die block of described mould molding part all adopt block form, are convenient to push the taking-up of workpiece after completing and the extruding again of blank.

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