Combined compression-molding device for tapered body, and compression molding method

Abstract

A combined compression-molding device for a tapered body, and a compression molding method. The device comprises: a punch (1), a die (5), a stripper fixing plate (2), a blank positioning ring (3), a prestress ring (6) and an ejector pin (7), wherein the die (5) is mounted in the prestress ring (6), the ejector pin (7) is inserted into a bottom-end hole of the die (5), the blank positioning ring (3) is mounted in a top-end hole of the die (5), and the stripper fixing plate (2) is mounted on the top end of the die (5) and the top end of the prestress ring (6). The compression molding method comprises: step one, placing a blank positioning ring (3) at the top of a die (5); step two, placing a blank (4) into the die (5); step three, taking out the blank positioning ring (3), and mounting a stripper (21) in a stripper fixing plate (2); step four, moving a punch (1) downwards to compress the blank (4); step five, moving the punch (1) upwards and withdrawing same from a cavity of the die (5); and step six, taking out the stripper (21), and ejecting out a part (8).

Description

Conical body composite extrusion forming device and extrusion forming method Technical Field

[0001] The present invention relates to an extrusion forming device and an extrusion forming method, and in particular to a conical body composite extrusion forming device and an extrusion forming method, belonging to the technical field of metal hot forming. Background Art

[0002] Conical metal structural parts are widely used in missile launches and aircraft structures. Conical materials are mostly made of difficult-to-process materials such as high-strength steel and high-temperature alloys. Their functions determine the high dimensional accuracy requirements of the parts, while their structure makes it difficult to form the parts. Usually, rods are directly cut to the final part shape, or the extruded blanks obtained after extrusion are cut. The former has serious material waste and low production efficiency, which is not in line with the concept of green manufacturing and is not conducive to controlling production costs. The latter has relatively high material utilization and production efficiency. However, the extruded blank is prone to tilting during forming using the current ordinary extrusion forming method, and the extrusion forming accuracy cannot be guaranteed, and it may even cause the blank to crack. In this case, a large cutting allowance needs to be reserved for the extruded blank. Therefore, it is necessary to develop new precision extrusion forming methods to improve extrusion forming accuracy, reduce cutting allowance, and improve material utilization.

[0003] Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the extruded billet is prone to tilting during the extrusion forming method, the extrusion forming accuracy cannot be guaranteed, and even the billet cracks, and a large cutting processing allowance needs to be reserved for the billet after extrusion, and further provide a conical body composite extrusion forming device and extrusion forming method.

[0005] The technical solution of the present invention is:

[0006] A conical body composite extrusion forming device comprises a punch and a die, and also comprises a stripper plate fixing plate, a blank positioning ring, a prestressed ring and a push rod; the die is installed in the prestressed ring, the push rod is inserted in the bottom end hole of the die, the blank positioning ring is installed in the hole at the top end of the die, and the stripper plate fixing plate is installed on the top end of the die and the top end of the prestressed ring.

[0007] Furthermore, it also includes a stripper plate; the stripper plate is an annular plate, and the stripper plate is disassembled and installed on the stripper plate fixing plate.

[0008] Furthermore, an annular groove is processed radially on the inner side wall of the stripper plate fixing plate, and the stripper plate is installed in the annular groove of the stripper plate fixing plate.

[0009] Furthermore, the stripper plate fixing plate is an annular sleeve, the prestressed ring is an annular cylinder, the die is a circular cylinder, the center hole of the circular cylinder is composed of a conical hole and a circular hole connected, the blank positioning ring is a conical sleeve, the outer cylindrical surface of the conical sleeve is a conical surface, and the center hole of the conical sleeve is a circular through hole.

[0010] Furthermore, the die is mounted on the inner side wall of the prestressed ring, the conical surface of the blank positioning ring is mounted in the conical hole at the top of the die, and the ejector pin is mounted in the circular hole of the die.

[0011] An extrusion forming method of a conical body composite extrusion forming device is implemented according to the following steps:

[0012] Step 1: Place the blank locating ring on top of the conical hole of the die;

[0013] Step 2: Place the blank into the die through the blank positioning ring, so that the ejector pin is pressed into the groove at the bottom of the blank, and the top of the blank overlaps the bottom of the blank positioning ring;

[0014] Step 3: Remove the blank positioning ring and install the stripper plate into the slot of the stripper plate fixing plate;

[0015] Step 4: Start the downward movement of the punch to extrude the blank, so that the material at the bottom of the blank flows downward and the material at the top of the blank flows upward, and finally the blank fills the concave mold cavity;

[0016] Step 5: Move the punch upward and exit the concave mold cavity;

[0017] Step 6: Remove the stripper plate and move the ejector pin upward to eject the part from the concave mold cavity.

[0018] Furthermore, in step 2, the blank is placed into the die through the blank positioning ring, and the overlapping length L between the top of the blank and the bottom of the blank positioning ring is 5 mm to 10 mm.

[0019] Furthermore, when the blank is placed in the die in step 2, the shape of the blank is an integrated structure with an inverted truncated cone section at the bottom and a cylindrical section at the top, the height of the cylindrical section is H1, the height of the inverted truncated cone section is H2, and the ratio of H1 to H2 is in the range of 5:3 to 5:4.

[0020] Furthermore, in step 2, the depth of the groove at the bottom of the blank is 15 mm to 20 mm.

[0021] Compared with the prior art, the present invention has the following effects:

[0022] The present invention uses a composite hot extrusion method to achieve the precise forming of a double-sided hollow cone. A blank positioning ring is used to position the blank, ensuring that the blank is accurately positioned initially and coaxially with the die when placed. The blank shape comprises cylindrical and truncated cone sections of a certain length, which not only stabilizes the center of gravity of the blank during extrusion but also ensures a high material utilization rate. Furthermore, the outer surface of the truncated cone section fits against the inner wall of the die, and the groove at the bottom of the blank cooperates with the ejector pin, both of which position the blank during extrusion, reliably preventing the blank from tilting during extrusion and maintaining axial symmetry of the part after extrusion. This improves extrusion forming accuracy, reduces final forming cutting allowance, increases material utilization, and reduces manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic diagram of a double-sided hollow cone part 8;

[0024] FIG2 is a schematic diagram of a blank 4;

[0025] FIG3 is a schematic structural diagram of a device for precision composite extrusion of a double-sided hollow cone;

[0026] FIG4 is a schematic diagram showing a state where a blank 4 is placed in a die 5;

[0027] Figure 5 is a schematic diagram of the state where the stripper plate is installed after the blank positioning ring 3 is removed;

[0028] Figure 6 is a schematic diagram of the initial state before extrusion;

[0029] FIG7 is a schematic diagram of the extrusion molding completion state. DETAILED DESCRIPTION

[0030] Specific embodiment 1: This embodiment is described in conjunction with Figures 3 to 7. This embodiment is a conical body composite extrusion forming device, which includes a punch 1 and a die 5, and it also includes a stripper plate fixing plate 2, a blank positioning ring 3, a prestressed ring 6 and a push rod 7; the die 5 is installed in the prestressed ring 6, the push rod 7 is inserted in the bottom end hole of the die 5, the blank positioning ring 3 is installed in the hole at the top of the die 5, and the stripper plate fixing plate 2 is installed on the top of the die 5 and the top of the prestressed ring 6.

[0031] In this embodiment, the punch 1 is used to extrude the cavity at the top of the part, and the blank fixing ring 3 is placed on the top of the inner cavity of the die 5 to ensure that the blank 4 is placed in the center position of the die 5 and remains vertical before extrusion.

[0032] Specific Embodiment 2: This embodiment is described with reference to Figures 5-7 . This embodiment provides a conical composite extrusion forming device, further comprising a stripper plate 21; this is an annular plate that can be removed and mounted on a stripper plate fixing plate 2. The stripper plate 21 is mounted within a slot in the stripper plate fixing plate 2 and is used to remove the extruded part 8. The remaining components and connections are identical to those of Specific Embodiment 1.

[0033] Specific embodiment three: This embodiment is described with reference to Figures 5-7. This embodiment is a conical body composite extrusion forming device. An annular groove is radially machined on the inner side wall of the stripper plate fixing plate 2, and the stripper plate 21 is installed in the annular groove of the stripper plate fixing plate 2. The other components and connection relationships are the same as those of specific embodiment two.

[0034] Specific embodiment 4: This embodiment is described with reference to Figures 5-7. This embodiment is a conical composite extrusion forming device. The stripper plate fixing plate 2 is an annular sleeve, the prestressing ring 6 is an annular cylinder, the die 5 is a circular cylinder, the center hole of the circular cylinder is a connecting tapered hole and a circular hole, and the blank positioning ring 3 is a tapered sleeve with a tapered outer surface and a circular through-hole at its center. Other components and connections are the same as those in specific embodiment 1.

[0035] Specific embodiment five: This embodiment is described in conjunction with Figure 5. This embodiment is a conical body composite extrusion forming device, in which the die 5 is installed on the inner wall of the prestressed ring 6, the conical surface of the blank positioning ring 3 is installed in the conical hole at the top of the die 5, and the push rod 7 is installed in the circular hole of the die 5.

[0036] The top of the ejector pin 7 is an integrated cylindrical protrusion, a disc-shaped body, and a bottom end. The cylindrical protrusion is seated in the groove 41, and the disc-shaped body is installed in the circular hole of the blank positioning ring 3. The ejector pin 7 is used to eject the extruded part 8 from the die 5. The other components and connection relationships are the same as those of the first embodiment.

[0037] Specific embodiment six: This embodiment is described in conjunction with Figures 2 to 7. This embodiment is an extrusion forming method of a conical body composite extrusion forming device, and the method is implemented according to the following steps:

[0038] Step 1: Place the blank positioning ring 3 on top of the tapered hole of the die 5;

[0039] Step 2: Place the blank 4 into the die 5 through the blank positioning ring 3, so that the push rod 7 is pressed into the groove 41 at the bottom of the blank 4, so that the top of the blank 4 coincides with the bottom of the blank positioning ring 3;

[0040] Step 3: Take out the blank positioning ring 3 and install the stripper plate 21 into the slot of the stripper plate fixing plate 2;

[0041] Step 4: Start the punch 1 to move downward to extrude the blank 4, so that the material at the bottom of the blank flows downward and the material at the top of the blank flows upward, and finally the blank fills the concave mold cavity;

[0042] Step 5: Move the punch 1 upward and exit the cavity of the die 5;

[0043] Step 6: Take out the stripper plate 21, and move the ejector pin 7 upward to eject the part 8 from the cavity of the die 5.

[0044] Specific Embodiment 7: This embodiment is described with reference to Figure 4 . This embodiment describes an extrusion forming method for a conical composite extrusion forming apparatus. In step 2, the blank 4 is placed into the die 5 via the blank positioning ring 3 . The overlap length L between the top of the blank 4 and the bottom of the blank positioning ring 3 is 5 to 10 mm. This technical solution ensures that the blank 4 is accurately positioned initially when placed in the die 5 and remains coaxial with the die 5. Other components and connections are the same as those in Specific Embodiment 6.

[0045] Specific embodiment eight: This embodiment is described in conjunction with Figures 5-7. This embodiment is an extrusion forming method of a conical body composite extrusion forming device. When the billet 4 is placed in the die 5 in step two, the billet 4 is in the shape of an integrated structure with an inverted truncated cone section at the bottom and a cylindrical section at the top. The height of the cylindrical section is H1, the height of the inverted truncated cone section is H2, and the ratio of H1 to H2 ranges from 5:3 to 5:4. The above technical solution can facilitate the maintenance of a stable center of gravity of the billet during the extrusion process while ensuring a high material utilization rate. The other components and connection relationships are the same as those of specific embodiment six.

[0046] Specific Embodiment 9: This embodiment is described with reference to Figures 5-7 . This embodiment describes an extrusion method for a conical composite extrusion forming apparatus. In step 2, the depth of the groove 41 at the bottom of the blank 4 is 15 to 20 mm. Using this technical solution, after the blank 4 is placed in the die 5 , a gap is formed between the bottom groove 41 and the ejector pin 7 . This, combined with the flattened cone section of the blank and the die, prevents the blank from tilting during extrusion, resulting in an axially symmetrical part after extrusion. Other components and connections are identical to those in Specific Embodiment 6.

[0047] The present invention has been disclosed above with reference to preferred embodiments, but this is not intended to limit the present invention. Any person skilled in the art who, without departing from the scope of the technical solution of the present invention, can make slight changes or modifications to the above-disclosed structures and technical contents to produce equivalent embodiments with equivalent changes, all of which still fall within the scope of the technical solution of the present invention.

Claims

1. A conical body composite extrusion forming device, comprising a male die (1) and a female die (5), characterized in that: It also includes a stripper plate fixing plate (2), a blank positioning ring (3), a prestressed ring (6) and a push rod (7); the die (5) is installed in the prestressed ring (6), the push rod (7) is inserted into the bottom end hole of the die (5), the blank positioning ring (3) is installed in the hole at the top end of the die (5), and the stripper plate fixing plate (2) is installed on the top end of the die (5) and the top end of the prestressed ring (6).

2. The conical body composite extrusion forming device according to claim 1, characterized in that: It also includes a stripping plate (21); the stripping plate (21) is an annular plate, and the stripping plate (21) is detachably mounted on the stripping plate fixing plate (2).

3. The conical body composite extrusion forming device according to claim 2, characterized in that: An annular groove is processed radially on the inner side wall of the stripper plate fixing plate (2), and the stripper plate (21) is installed in the annular groove of the stripper plate fixing plate (2).

4. The conical body composite extrusion forming device according to claim 1, characterized in that: The stripper plate fixing plate (2) is an annular sleeve, the prestressed ring (6) is an annular cylinder, the die (5) is a circular cylinder, the center hole of the circular cylinder is composed of a tapered hole and a circular hole connected, the blank positioning ring (3) is a tapered sleeve, the outer cylindrical surface of the tapered sleeve is a tapered surface, and the center hole of the tapered sleeve is a circular through hole.

5. The conical body composite extrusion forming device according to claim 4, characterized in that: The die (5) is mounted on the inner side wall of the prestressed ring (6), the conical surface of the blank positioning ring (3) is mounted in the conical hole at the top of the die (5), and the push rod (7) is mounted in the circular hole of the die (5).

6. An extrusion forming method using the conical body composite extrusion forming device according to any one of claims 1 to 5, characterized in that: The method is implemented according to the following steps: Step 1: Place the blank positioning ring (3) on top of the tapered hole of the die (5); Step 2: Place the blank (4) into the die (5) through the blank positioning ring (3), so that the push rod (7) is pushed into the groove (41) at the bottom of the blank (4), so that the top of the blank (4) overlaps with the bottom of the blank positioning ring (3); Step 3: Take out the blank positioning ring (3) and install the stripper plate (21) into the slot of the stripper plate fixing plate (2); Step 4: Start the punch (1) to move downward to extrude the blank (4), so that the material at the bottom of the blank flows downward and the material at the top of the blank flows upward, and finally the blank fills the concave mold cavity; Step 5: Move the punch (1) upward and exit the cavity of the die (5); Step 6: Take out the stripper plate (21), and move the ejector rod (7) upward to eject the part (8) out of the cavity of the die (5).

7. The extrusion forming method of the conical body composite extrusion forming device according to claim 6, characterized in that: In step 2, the blank (4) is placed into the die (5) through the blank positioning ring (3), and the overlapping length L between the top of the blank (4) and the bottom of the blank positioning ring (3) is 5 mm to 10 mm.

8. The extrusion forming method of the conical body composite extrusion forming device according to claim 6, characterized in that: When the blank (4) is placed in the die (5) in step 2, the shape of the blank (4) is an integrated structure with an inverted truncated cone section at the bottom and a cylindrical section at the top, the height of the cylindrical section is H1, the height of the inverted truncated cone section is H2, and the ratio of H1 to H2 is in the range of 5:3 to 5:

4.

9. The extrusion forming method of the conical body composite extrusion forming device according to claim 6, characterized in that: In step 2, the depth of the groove (41) at the bottom of the blank (4) is 15 mm to 20 mm.

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