CN106540976A - A kind of shaped device and its moulding process of the long tubing of hydrostatic extrusion magnesium alloy - Google Patents

Abstract

The invention discloses a forming device for hydrostatically extruding long magnesium alloy pipes and a forming process thereof. The forming device includes a first fixing frame, a second fixing frame, a supporting cylinder, a mould, an extrusion cylinder, a pressure medium exchange plate, a belt High pressure hydraulic pump with extrusion shaft and piercing needle. The support cylinder, mold, extrusion cylinder, pressure medium exchange plate and perforating needle are placed in the first fixed frame, and the high-pressure hydraulic pump with the extrusion shaft is placed in the second fixed frame. The present invention cancels the mold core structure and adopts the traveling perforating needle structure, which avoids the instability problem of the long mold core, can obtain longer-length magnesium alloy pipes, improves production efficiency, and has a simple structure and fewer parts, thereby making the cost low , High reliability.

Description

A forming device and forming process of hydrostatically extruded magnesium alloy long pipe

technical field

The invention belongs to the technical field of metal forming, and in particular relates to a forming device for hydrostatically extruding long magnesium alloy pipes and a forming process thereof.

Background technique

Common processing methods for magnesium alloys include casting, rolling, extrusion, stamping, hot forging, etc. Although casting is currently the main processing method for magnesium alloys, the performance of magnesium alloy castings is low and there are many defects, which are far from meeting the requirements for magnesium alloy parts in the field of national defense and military affairs. The strength, ductility and other mechanical properties of the extruded magnesium alloy products are significantly improved. In the conventional mechanical extrusion process, the rough billet will rub against the extrusion cylinder, and the surface quality of the obtained magnesium alloy product is poor.

The Chinese patent application number is CN201310108301.1 patent application, which discloses a mold with a core, which can perform expansion extrusion and contraction extrusion of magnesium alloy pipes. However, due to the use of the core structure, the stability of the core will decrease significantly with the increase of the length, making it difficult to obtain long pipes.

Contents of the invention

The object of the present invention is to provide a forming device for hydrostatically extruding long magnesium alloy pipes and a forming process thereof, which solves the problem that magnesium alloy materials are difficult to plastically form and the length of magnesium alloy pipes formed by hydrostatic extrusion is relatively short.

The technical solution to realize the object of the present invention is: a forming device for hydrostatically extruding magnesium alloy long pipes, including a first fixing frame, a second fixing frame, a support cylinder, a mold, an extrusion cylinder, a pressure medium exchange plate, a belt A high-pressure hydraulic pump with an extrusion shaft and a perforating needle; the support cylinder, mold, extrusion cylinder, pressure medium exchange plate and perforating needle are all placed in the first fixed frame, and the high-pressure hydraulic pump with an extrusion shaft is placed in the second inside the mount.

The first fixed frame includes a movable beam, a first fixed beam and N uprights, N≥4, and the movable beam and the first fixed beam are fixedly connected to the two ends of the N uprights respectively to form a frame structure together; There is a first through hole in the center, one end of the supporting cylinder is fixed at the center of the movable beam, and the other end is fixedly connected with the mold, and the other end of the mold is provided with a magnesium alloy billet to be processed, which is inserted into the extrusion cylinder, and the perforating needle is fixed on the On the magnesium alloy billet; the other end of the extrusion cylinder is fixedly connected with the pressure medium exchange plate, and the pressure medium exchange plate is fixed at the center of the first fixed beam; the center of the pressure medium exchange plate is provided with a second through hole, and the center of the first fixed beam is provided with a The second through hole has the same diameter as the third through hole, and the second through hole is connected with the third through hole.

The second fixed frame includes a second fixed beam, a third fixed beam and N uprights, N≥4, and the second fixed beam and the third fixed beam are fixedly connected to both ends of the N uprights respectively, forming a frame structure together ;The base of the high-pressure hydraulic pump with the extrusion shaft is fixed at the center of the third fixed beam, and one end with the extrusion shaft is fixed at the center of the second fixed beam, and the extrusion shaft passes through the second through hole and the third through hole into the extrusion barrel.

The inner diameter of the support cylinder is not smaller than the diameter of the first through hole.

An L-shaped through hole is provided on the pressure medium exchange plate, so that the inner cavity of the extrusion cylinder communicates with the outside world.

It also includes a sealing device, a sealing device is provided at the connection between the extrusion cylinder and the pressure medium exchange plate, and a sealing device is provided at the connection between the extrusion cylinder and the mold. The sealing device is an O-shaped sealing ring and a metal triangular pad. device to achieve static sealing.

It also includes a sealing ring, and a sealing ring is provided at the connection between the pressure medium exchange plate and the extrusion shaft to realize dynamic sealing.

The frame structure is a quadrilateral frame structure.

A forming process for hydrostatically extruded magnesium alloy long pipes, the steps are as follows:

Step 1), according to the need, perform homogenization heat treatment on the magnesium alloy billet to be processed, and process a blind hole matching the perforating needle at one end of the billet.

Step 2): Press the magnesium alloy billet in step 1) into the mold with a hydraulic extruder, and the two have an interference fit, and the part of the mold and the magnesium alloy billet has a taper to ensure the initial sealing of the magnesium alloy billet.

Step 3) After coating the perforating needle with grease, put it into the blind hole of the magnesium alloy blank.

Step 4) Install a sealing device at the mold, insert the magnesium alloy billet assembled with the mold and one end of the perforating needle into the extrusion cylinder for docking.

Step 5), dock the other end of the mold with the support cylinder and assemble.

Step 6), pass the movable beam through the Zhang column, adjust the parallelism between the movable beam and the first fixed beam, and fix the supporting cylinder.

Step 7) Use a low-pressure hot oil pump connected to an external hydraulic system to fill the extrusion barrel with high-temperature extrusion medium.

Step 8), start the high-pressure hydraulic pump, and the extrusion shaft enters the extrusion cylinder filled with high-temperature extrusion medium under the push of the high-pressure hydraulic pump, generating a pressure field with a pressure greater than 500MPa, and the magnesium alloy billet is squeezed between the mold and the perforating needle out to obtain a shaped pipe.

Compared with the prior art, the present invention has significant advantages in that: (1) ultra-high pressure hydrostatic extrusion of magnesium alloy pipes can be realized; (2) magnesium alloy pipes with longer length can be formed; Under the action of pressure, it is extruded in the mold at one time to achieve high precision, no need for finishing, and the product is close to net shape; (4) Easy to operate, controllable production process, low risk factor, few parts of the device, and high reliability high.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the hydrostatically extruded magnesium alloy long pipe forming device of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, a forming device for hydrostatically extruding magnesium alloy long pipes adopts a four-beam and four-column horizontal structure, including a first fixing frame, a second fixing frame, a supporting cylinder 3, a mold 4, an extrusion cylinder 5, a pressing Medium exchange disc 8, high pressure hydraulic pump 11 with extrusion shaft 7 and perforating needle 16.

The supporting cylinder 3, the mold 4, the extruding cylinder 5, the pressure medium exchange plate 8 and the perforating needle 16 are all placed in the first fixed frame, and the high-pressure hydraulic pump 11 with the extruding shaft 7 is placed in the second fixed frame.

The first fixed frame includes a movable beam 1, a first fixed beam 9 and N upright columns 2, N≥4, and the movable beam 1 and the first fixed beam 9 are fixedly connected to both ends of the N upright columns 2 respectively to form a frame structure , the center of the movable beam 1 has a first through hole, one end of the support tube 3 is fixed at the center of the movable beam 1, and the other end is fixedly connected with the mold 4, and the other end of the mold 4 is provided with a magnesium alloy blank 17 to be processed, and it is stretched Into the extrusion cylinder 5, the perforating needle 16 is fixed on the magnesium alloy blank 17. The other end of the extrusion cylinder 5 is fixedly connected with the pressure medium exchange plate 8 , and the pressure medium exchange plate 8 is fixed at the center of the first fixed beam 9 . The center of the pressure medium exchange plate 8 is provided with a second through hole, and the center of the first fixed beam 9 is provided with a third through hole having the same diameter as the second through hole, and the second through hole and the third through hole are connected.

The second fixed frame includes a second fixed beam 10, a third fixed beam 12 and N columns 2, N≥4, and the second fixed beam 10 and the third fixed beam 12 are fixedly connected to the two ends of the N columns 2 respectively, together form a frame structure. The base of the high-pressure hydraulic pump 11 with the extrusion shaft 7 is fixed at the center of the third fixed beam 12, and one end with the extrusion shaft 7 is fixed at the center of the second fixed beam 10, and the extrusion shaft 7 passes through the second through hole And the third through hole extends into the extrusion barrel 5.

The inner diameter of the support cylinder 3 is not smaller than the diameter of the first through hole.

The frame structure is a quadrilateral frame structure.

An L-shaped through hole is provided on the pressure medium exchange plate 8, so that the inner cavity of the extrusion cylinder 5 communicates with the outside world. Through the L-shaped through hole, the low-pressure oil pump connected to the external hydraulic system will squeeze with a certain pressure and temperature. The medium 6 is injected into the extrusion barrel 5 .

A sealing device 18 is provided at the connection between the extrusion cylinder 5 and the pressure medium exchange plate 8, and a sealing device 18 is provided at the connection between the extrusion cylinder 5 and the mold 4. The sealing device 18 is an O-shaped sealing ring and a metal triangular pad. Device 18 realizes static sealing. A sealing ring 14 is provided at the joint between the pressure medium exchange disc 8 and the extruding shaft 7 to realize dynamic sealing.

A forming process for hydrostatically extruded magnesium alloy long pipes, the steps are as follows:

Step 1), according to the need, perform homogenization heat treatment on the magnesium alloy billet to be processed, and process a blind hole matching the perforating needle at one end of the billet.

Step 2): Press the magnesium alloy billet in step 1) into the mold with a hydraulic extruder, and the two have an interference fit, and the part of the mold and the magnesium alloy billet has a taper to ensure the initial sealing of the magnesium alloy billet.

Step 3) After coating the perforating needle with grease, put it into the blind hole of the magnesium alloy blank.

Step 4) Install a sealing device at the mold, insert the magnesium alloy billet assembled with the mold and one end of the perforating needle into the extrusion cylinder for docking.

Step 5), dock the other end of the mold with the support cylinder and assemble.

Step 6), pass the movable beam through the Zhang column, adjust the parallelism between the movable beam and the first fixed beam, and fix the supporting cylinder.

Step 7) Use a low-pressure hot oil pump connected to an external hydraulic system to fill the extrusion barrel with high-temperature extrusion medium.

Step 8), start the high-pressure hydraulic pump, and the extrusion shaft enters the extrusion cylinder filled with high-temperature extrusion medium under the push of the high-pressure hydraulic pump, generating a pressure field with a pressure greater than 500MPa, and the magnesium alloy billet is squeezed between the mold and the perforating needle out to obtain a shaped pipe.

Example 1

Referring to Fig. 1, a forming device for hydrostatically extruding magnesium alloy long pipes adopts a four-beam and four-column horizontal structure, including a first fixing frame, a second fixing frame, a supporting cylinder 3, a mold 4, an extrusion cylinder 5, a pressing Medium exchange disc 8, high pressure hydraulic pump 11 with extrusion shaft 7 and perforating needle 16.

The supporting cylinder 3, the mold 4, the extruding cylinder 5, the pressure medium exchange plate 8 and the perforating needle 16 are all placed in the first fixed frame, and the high-pressure hydraulic pump 11 with the extruding shaft 7 is placed in the second fixed frame.

The first fixed frame comprises a movable beam 1, a first fixed beam 9 and four columns 2, and the movable beam 1 and the first fixed beam 9 are fixedly connected to the two ends of the four columns 2 respectively, forming a rectangular frame structure together, wherein the movable The beam 1 is a movable beam, which is convenient for fixing and installing the mold 4 and the extrusion cylinder 5 during the forming process. There is a first through hole in the center of the movable beam 1, which is convenient for forming pipes to pass through. One end of the support tube 3 is fixed in the center of the movable beam 1, and the other end is fixedly connected with the mold 4. The other end of the mold 4 is provided with a magnesium alloy blank to be processed. 17, and extend it into the extrusion cylinder 5, and the perforating needle 16 is fixed on the magnesium alloy blank 17. The other end of the extrusion cylinder 5 is fixedly connected with the pressure medium exchange plate 8, and the pressure medium exchange plate 8 is fixed at the center of the first fixed beam 9. The center of the pressure medium exchange plate 8 is provided with a second through hole, and the center of the first fixed beam 9 is provided with a third through hole having the same diameter as the second through hole, and the second through hole and the third through hole are connected. Two ends of the four columns 2 are respectively provided with nuts 13, and the support cylinder 3, the mold 4, the extrusion cylinder 5 and the pressure medium exchange plate 8 are fixed between the movable beam 1 and the first fixed beam 9 by the nuts 13.

The second fixed frame includes a second fixed beam 10, a third fixed beam 12 and four columns 2, and the second fixed beam 10 and the third fixed beam 12 are fixedly connected to the two ends of the four columns 2 respectively to form a rectangular frame. structure. The base of the high-pressure hydraulic pump 11 with the extrusion shaft 7 is fixed at the center of the third fixed beam 12, and one end with the extrusion shaft 7 is fixed at the center of the second fixed beam 10, and the extrusion shaft 7 passes through the second through hole And the third through hole extends into the extrusion barrel 5. Nuts 13 are respectively provided at both ends of the four upright columns 2 , and the high-pressure hydraulic pump 11 is fixed between the second fixed beam 10 and the third fixed beam 12 through the nuts 13 .

The inner diameter of the support cylinder 3 is not smaller than the diameter of the first through hole.

An L-shaped through hole is provided on the pressure medium exchange plate 8, so that the inner cavity of the extrusion cylinder 5 communicates with the outside world. Through the L-shaped through hole, the low-pressure oil pump connected to the external hydraulic system will have a certain pressure and temperature. The medium 6 is injected into the extrusion barrel 5 .

A sealing device 18 is provided at the connection between the extrusion cylinder 5 and the pressure medium exchange plate 8, and a sealing device 18 is provided at the connection between the extrusion cylinder 5 and the mold 4. The sealing device 18 is an O-shaped sealing ring and a metal triangular pad. Device 18 realizes static sealing. A sealing ring 14 is provided at the joint between the pressure medium exchange disc 8 and the extruding shaft 7 to realize dynamic sealing.

A forming process for hydrostatically extruded magnesium alloy long pipes, the steps are as follows: ① according to the needs, perform homogenization heat treatment on the magnesium alloy billet 17 to be processed, and process a blind hole matched with the perforating needle 16 at one end of the billet; ② use The hydraulic extrusion machine presses the magnesium alloy billet 17 in step ① into the mold 4, and the two are interference fit. The part of the mold 4 and the magnesium alloy billet 17 has a taper to ensure the initial sealing of the magnesium alloy billet 17; After the needle 16 is coated with grease, put it into the blind hole of the magnesium alloy billet 17; ④ Install the sealing device 18 at the mold 4, and put the mold 4 with the magnesium alloy billet 17 and one end of the perforating needle 16 into the extrusion cylinder 5 Docking; ⑤ docking and assembling the other end of the mold 4 with the supporting cylinder 3; ⑥ passing the movable beam 1 through the vertical column 2, adjusting the parallelism between the movable beam 1 and the first fixed beam 9, and fixing the supporting cylinder 3 with the set nut 13 ;⑦Use the low-pressure (less than 70 MPa) hot oil pump of the external hydraulic system to squeeze the high-temperature extrusion medium 6 and fill the extrusion cylinder 5; In the extrusion cylinder 5 of the high-temperature extrusion medium 6, a pressure field with a pressure greater than 500 MPa is generated, and the magnesium alloy billet 17 is extruded between the die 4 and the perforating needle 16 to obtain a shaped pipe.

If you want to obtain pipes with different wall thickness ratios, you only need to adjust the structural dimensions of the perforating needle 16, the magnesium alloy blank 17 and the mold 4, and repeat the above steps.

Since the molding device for hydrostatically extruded long magnesium alloy pipes according to the present invention cancels the mold core structure and adopts the accompanying perforating needle structure, the problem of instability of the long mold core is avoided, thereby obtaining longer magnesium alloy pipes . The device of the invention has a simpler structure and fewer parts, so that the cost is lower and the reliability is higher.

Claims (7)

1. A forming device for hydrostatically extruding magnesium alloy long pipes, characterized in that: it includes a first fixing frame, a second fixing frame, a support cylinder (3), a mold (4), an extrusion cylinder (5), a press Medium exchange plate (8), high-pressure hydraulic pump (11) with extrusion shaft (7) and perforating needle (16); support cylinder (3), mold (4), extrusion cylinder (5), pressure medium exchange The disk (8) and the piercing needle (16) are both placed in the first fixed frame, and the high-pressure hydraulic pump (11) with the extrusion shaft (7) is placed in the second fixed frame; The first fixed frame includes a movable beam (1), a first fixed beam (9) and N uprights (2), N≥4, and the movable beam (1) and the first fixed beam (9) are respectively fixed on The two ends of N columns (2) together form a frame structure; the center of the movable beam (1) has a first through hole, one end of the support tube (3) is fixed in the center of the movable beam (1), and the other end is connected with the mold (4 ), the other end of the mold (4) is provided with a magnesium alloy blank (17) to be processed, and it is extended into the extrusion cylinder (5), and the perforating needle (16) is fixed on the magnesium alloy blank (17); The other end of the extrusion cylinder (5) is fixedly connected with the pressure medium exchange plate (8), and the pressure medium exchange plate (8) is fixed at the center of the first fixed beam (9); the center of the pressure medium exchange plate (8) is provided with a second hole, the center of the first fixed beam (9) is provided with a third through hole having the same diameter as the second through hole, and the second through hole and the third through hole are connected; The second fixed frame includes a second fixed beam (10), a third fixed beam (12) and N uprights (2), N≥4, the second fixed beam (10) and the third fixed beam (12) They are fixedly connected to both ends of N upright columns (2) to form a frame structure together; the base of the high-pressure hydraulic pump (11) with an extrusion shaft (7) is fixed at the center of the third fixed beam (12), with One end of the extrusion shaft (7) is fixed at the center of the second fixed beam (10), and the extrusion shaft (7) extends into the extrusion cylinder (5) through the second through hole and the third through hole. 2. The forming device for hydrostatically extruding long magnesium alloy pipes according to claim 1, characterized in that: the inner diameter of the support cylinder (3) is not smaller than the diameter of the first through hole. 3. The forming device for hydrostatically extruding magnesium alloy long pipes according to claim 1, characterized in that: the pressure medium exchange plate (8) is provided with an L-shaped through hole, so that the extrusion cylinder (5) The inner cavity communicates with the outside world. 4. The forming device for hydrostatically extruding magnesium alloy long pipes according to claim 1, characterized in that it further comprises a sealing device (18), and the extrusion cylinder (5) is connected to the pressure medium exchange plate (8) A sealing device (18) is provided at the junction of the extrusion cylinder (5) and the mold (4). The sealing device (18) is an O-ring and a metal triangular gasket. (18), to achieve static sealing. 5. The forming device for hydrostatically extruding magnesium alloy long pipes according to claim 1, characterized in that: it also includes a sealing ring (14), the connection between the pressure medium exchange plate (8) and the extrusion shaft (7) A sealing ring (14) is provided to realize dynamic sealing. 6 . The forming device for hydrostatically extruding long magnesium alloy pipes according to claim 1 , wherein the frame structure is a quadrilateral frame structure. 7 . 7. The forming process based on the forming device of the hydrostatically extruded magnesium alloy long pipe according to claim 1, is characterized in that, the steps are as follows: Step 1), according to needs, perform homogenization heat treatment on the magnesium alloy billet (17) to be processed, and process a blind hole matched with the perforating needle (16) at one end of the billet; Step 2), using a hydraulic extrusion machine to press the magnesium alloy billet (17) in step 1) into the mold (4), the two have an interference fit, and the mold (4) and the magnesium alloy billet (17) have a taper , to ensure the initial sealing of the magnesium alloy billet (17); Step 3), after coating the perforating needle (16) with grease, put it into the blind hole of the magnesium alloy blank (17); Step 4), install the sealing device (18) at the mold (4), put the magnesium alloy billet (17) and the piercing needle (16) on the mold (4) into the extrusion cylinder (5) for docking; Step 5), docking and assembling the other end of the mold (4) with the support cylinder (3); Step 6), pass the movable beam (1) through the column (2), adjust the parallelism between the movable beam (1) and the first fixed beam (9), and fix the support tube (3); Step 7), use the low-pressure hot oil pump connected to the external hydraulic system to fill the extrusion cylinder (5) with the high-temperature extrusion medium (6); Step 8), start the high-pressure hydraulic pump (11), the extrusion shaft (7) enters the extrusion cylinder (5) filled with high-temperature extrusion medium (6) under the push of the high-pressure hydraulic pump (11), and the pressure is greater than 500MPa In the pressure field, the magnesium alloy billet (17) is extruded between the die (4) and the perforating needle (16) to obtain a shaped pipe.