A near-net-shape forming method for a pump housing of a wet-winding motor main pump

Abstract

The application discloses a near-net forming method for a pump shell of a CAP1400 wet-winding motor main pump, and belongs to the technical field of the forming of the pump shell of the CAP1400 wet-winding motor main pump. The method comprises the following steps: S1, performing multiple upsetting and elongating on a pump shell blank until the pump shell blank reaches a set state; S2, placing the pump shell blank on a profiling lower die, and stamping the pump shell blank by using a stepped mandrel to realize the profiling forming of a straight pipe nozzle shape of the pump shell, a variable cross-section inner cavity of the pump shell and a straight pipe nozzle inner hole; S3, rotating and upsetting the pump shell blank; and S4, placing the pump shell blank after the rotation of the pump shell blank on an anvil of a lower die to realize the forming of a single-side pipe nozzle of the pump shell. The application solves the technical problems of the profiling forging of the variable cross-section inner cavity of the pump shell, the straight pipe nozzle shape, the straight pipe nozzle inner hole and the single-side pipe nozzle of the pump shell of the CAP1400 wet-winding motor main pump, realizes the near-net forming of the pump shell, improves the product utilization, shortens the product processing period, and greatly reduces the production and manufacturing cost of the pump shell of the CAP1400 wet-winding motor main pump.

Description

Technical Field

[0001] This invention relates to the field of metal material forming technology, and in particular to a near-net-shape forming method for the main pump casing of a wet-wound motor. Background Technology

[0002] The reactor coolant circulation main pump is a crucial power unit in a nuclear power plant, serving as the power source for the coolant circulation system. Its function is to drive the high-speed, stable circulation of coolant in the primary loop to cool the reactor core and transfer heat to the secondary loop, while simultaneously cooling the core to prevent fuel element burnout. The main pump operates in an extremely harsh environment, especially the pump casing, which is subjected to prolonged exposure to high temperatures, high corrosion, and high radiation. Therefore, the pump casing requires extremely high safety and reliability. Previously, third-generation nuclear power coolant pump casings were forged as a single piece; however, this method suffered from low steel ingot utilization and long processing cycles. Summary of the Invention

[0003] Therefore, it is necessary to provide a near-net-shape forming method for the main pump casing of a wet-wound motor to address the aforementioned technical problems.

[0004] A near-net-shape forming method for the main pump casing of a wet-wound motor includes the following steps:

[0005] S1. The pump casing blank is upset and drawn multiple times until it reaches the set state;

[0006] S2. Place the pump casing blank on the lower mold and use a stepped mandrel to stamp the pump casing blank to achieve the straight nozzle shape of the pump casing, the variable cross-section inner cavity of the pump casing and the inner hole of the straight nozzle.

[0007] S3. Perform rotary upsetting on the pump casing blank;

[0008] S4. After rotating the pump casing blank by an angle, place it on the lower anvil to achieve single-sided nozzle forming of the pump casing.

[0009] In one embodiment, step S1 includes:

[0010] S11. Upset the pump casing blank to a height H1, and then forcefully draw it to a length D1.

[0011] S12. Continue to upset the pump casing blank to a height H2, then draw it with strong pressure to a length D2, and then cut the handle and bottom with gas cutting. The height H1 is greater than the height H2, and the length D1 is less than the length D2.

[0012] S13. Upset the pump casing blank to the set state.

[0013] In one embodiment, in step S2, the lower mold includes a lower mold body, and a forming hole is formed at the center of the lower mold body; the stepped core includes two shafts connected coaxially, the two shafts have different diameters and have a draft angle between them;

[0014] The stepped mandrel can penetrate the interior of the pump housing blank and squeeze the bottom of the pump housing blank into the mortise for forming. The inner cavity size of the pump housing is the size of the large end of the stepped mandrel.

[0015] In one embodiment, step S3 includes:

[0016] S31. An upper mold ring is fixed on the lower mold for shaping, and the upper mold ring is sleeved on the outside of the pump housing blank.

[0017] S32. Use a wide anvil and turntable fixture to rotate and upset the punched pump casing blank to fill the upper die ring.

[0018] In one embodiment, the outer wall of the upper mold ring is flush with the outer wall of the lower mold, and a through hole is provided on one side of the outer wall of the upper mold ring.

[0019] In one embodiment, in step S4, the lower anvil includes an anvil body, the upper surface of which has an arc-shaped groove, and the outer side wall of the upper mold ring and the outer side wall of the lower mold mate with the arc-shaped groove.

[0020] In one embodiment, step S4 includes:

[0021] S41. After rotating the pump casing blank with the upper mold ring, the lower mold and the stepped core rod as a whole by 90°, place it in the arc-shaped groove of the lower anvil.

[0022] S42. A punch is used to press the upper side wall of the pump casing blank through the through hole to form a single-sided nozzle.

[0023] In one embodiment, the punch includes a head and a punch rod connected to each other, the outer diameter of the punch rod being adapted to the inner diameter of the single-sided nozzle.

[0024] The aforementioned near-net-shape forming method for the pump casing of the wet-winding motor main pump solves the technical challenges of profile forging the pump casing's variable cross-section inner cavity, straight nozzle shape, straight nozzle inner hole, and single-sided nozzle in the CAP1400 wet-winding motor main pump casing. It achieves near-net-shape forming of the pump casing, improves product utilization, shortens product processing cycle, and significantly reduces the production and manufacturing cost of the CAP1400 wet-winding motor main pump casing. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the pump casing of the present invention.

[0027] Figure 2 This is a schematic diagram showing the state of the pump casing blank during the first upsetting and high-pressure drawing of the present invention;

[0028] Figure 3 This is a schematic diagram showing the state of the pump casing blank during the second upsetting and high-pressure drawing of the present invention;

[0029] Figure 4 This is a schematic diagram showing the state of the pump casing blank being upset to a set state according to the present invention;

[0030] Figure 5 This is a schematic diagram of the state of step S2 of the present invention;

[0031] Figure 6 This is a schematic diagram showing the straight nozzle shape, the pump housing variable cross-section inner cavity, and the straight nozzle inner hole after the simulation forming of the present invention.

[0032] Figure 7 This is a schematic diagram of the stepped mandrel of the present invention;

[0033] Figure 8 This is a schematic diagram of the lower mold structure of the present invention;

[0034] Figure 9 This is a schematic diagram of the state before upsetting and peeling in step S3 of the present invention;

[0035] Figure 10 This is a schematic diagram of the state after upsetting in step S3 of the present invention;

[0036] Figure 11 This is a schematic diagram of the connection structure between the upper mold ring and the lower mold of the present invention;

[0037] Figure 12 This is a schematic diagram of the state of the single-sided nozzle before molding in step S4 of the present invention.

[0038] Figure 13 This is a schematic diagram of the state of the single-sided nozzle after molding in step S4 of the present invention.

[0039] Figure 14 This is a schematic diagram of the punch structure of the present invention;

[0040] Figure 15This is a schematic diagram of the lower anvil structure of the present invention. Detailed Implementation

[0041] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0042] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0044] See Figure 1-15 As shown, an embodiment of the present invention provides a near-net-shape forming method for the main pump casing of a wet-wound motor, comprising the following steps:

[0045] S1. The pump casing blank 1 is upset and drawn multiple times until it reaches the set state;

[0046] S2. Place the pump housing blank 1 on the lower mold 2 and use the stepped mandrel 3 to stamp the pump housing blank 1 to achieve the forming of the straight nozzle shape 11, the variable cross-section inner cavity 12 of the pump housing and the straight nozzle inner hole 13.

[0047] S3. Rotary upsetting is performed on the pump casing blank 1;

[0048] S4. After rotating the pump casing blank 1 by an angle, place it on the lower anvil 4 to form the single-sided nozzle 14 of the pump casing.

[0049] The aforementioned near-net-shape forming method for the pump casing of the wet-wound motor main pump solves the technical challenges of profile forging of the pump casing variable cross-section inner cavity 12, straight nozzle shape 11, straight nozzle inner hole 13, and single-sided nozzle 14 of the CAP1400 wet-wound motor main pump casing. It achieves near-net-shape forming of the pump casing, improves product utilization, shortens product processing cycle, and significantly reduces the production and manufacturing cost of the CAP1400 wet-wound motor main pump casing.

[0050] In one embodiment of the present invention, step S1 includes:

[0051] S11. Upset the pump casing blank 1 to a height H1, and then forcefully draw it to a length D1.

[0052] S12. Continue to upset the pump casing blank 1 to a height H2, and then forcefully draw it to a length D2. After drawing, cut the handle and bottom with an oxy-acetylene torch. The height H1 is greater than the height H2, and the length D1 is less than the length D2.

[0053] S13. Upset the pump casing blank 1 to the set state.

[0054] In this embodiment, the pump casing blank 1 is given a sufficient forging ratio through two upsetting processes (H1 and H2) and two high-pressure drawing processes (D1 and D2) to ensure the overall compaction of the pump casing blank 1. In other embodiments of the present invention, the pump casing blank 1 may undergo more than three upsetting and high-pressure drawing processes to further ensure its compaction.

[0055] In one embodiment of the present invention, in step S2, the lower mold 2 includes a lower mold body 21, and a forming hole 22 is formed at the center of the lower mold body 21; the stepped core rod 3 includes two shafts connected coaxially, the two shafts have different diameters and have a draft angle between them.

[0056] The stepped mandrel 3 can penetrate the interior of the pump housing blank 1 and squeeze the bottom of the pump housing blank 1 into the shaped hole 22 for forming.

[0057] In this embodiment, the pump housing blank 1 is stamped by a stepped mandrel 3. The stepped mandrel 3 can penetrate the interior of the pump housing blank 1 to achieve the imitation forming of the pump housing variable cross-section inner cavity 12 and the straight nozzle inner hole 13. The bottom of the pump housing blank 1 is squeezed into the shaped hole 22, and the straight nozzle outer shape 11 can be directly formed according to the shape of the shaped hole 22. The forming is simple and convenient, and all parts of the forging are deformed to ensure good final performance.

[0058] In one embodiment of the present invention, step S3 includes:

[0059] S31. An upper mold ring 5 is fixed on the lower mold 2, and the upper mold ring 5 is sleeved on the outside of the pump housing blank 1.

[0060] S32. Using a wide anvil 6 and a turntable fixture, the punched pump casing blank 1 is rotated and upset to fill the upper die ring 5. This reduces the gap between the pump casing blank 1 and the upper die ring 5, so that the pump casing blank 1 is basically fixed in the cavity formed by the lower mold 2 and the upper die ring 5, which facilitates the subsequent forming of the single-sided nozzle 14.

[0061] In one embodiment of the present invention, the outer wall of the upper mold ring 5 is flush with the outer wall of the lower mold 2, and a through hole 51 is provided on one side of the outer wall of the upper mold ring 5. This ensures that the outer wall surfaces of the upper mold ring 5 and the lower mold 2 are aligned, avoiding interference with other components.

[0062] In one embodiment of the present invention, in step S4, the lower anvil 4 includes an anvil body 41, and an arc-shaped groove 42 is formed on the upper surface of the anvil body 41. The outer side wall of the upper mold ring 5 and the outer side wall of the contouring lower mold 2 cooperate with the arc-shaped groove 42. In this way, the upper mold ring 5 and the contouring lower mold 2 can be placed into the lower anvil 4 as a whole to increase the contact area with the arc-shaped groove 42 and improve the stability of the single-sided nozzle 14 during molding.

[0063] In one embodiment of the present invention, step S4 includes:

[0064] S41. After rotating the pump casing blank 1 with the upper mold ring 5, the lower mold 2 and the stepped core rod 3 by 90°, place it in the arc-shaped groove 42 of the lower anvil 4.

[0065] S42. The upper side wall of the pump housing blank 1 is extruded by the punch 7 through the through hole 51 to form a single-sided nozzle 14.

[0066] In this embodiment, the remaining parts of the pump housing blank 1 are fixed on the upper die ring 5, the lower die 2 and the stepped mandrel 3. When the punch 7 passes through the through hole 51 and squeezes the upper side wall of the pump housing blank 1, the corresponding part of the pump housing blank 1 will extend along the through hole 51, thereby realizing the molding of the single-sided nozzle 14.

[0067] In one embodiment of the present invention, the punch 7 includes a head 71 and a punch 72 connected to each other, the outer diameter of the punch 72 being adapted to the inner diameter of the single-sided nozzle 14. Thus, the inner hole of the single-sided nozzle 14 can be directly stamped using the punch 72, reducing subsequent processing steps.

[0068] In summary, this invention solves the technical challenges of forging the pump housing's variable cross-section inner cavity 12, straight nozzle shape 11, and single-sided nozzle 14 in the CAP1400 wet-winding motor main pump casing, achieving near-net-shape forming of the pump housing. This improves product utilization and significantly reduces the manufacturing cost of the CAP1400 wet-winding motor main pump casing. The pump housing body achieves good final performance through the contouring of the inner cavity and nozzle inner hole, with deformation in all parts of the forging. The straight nozzle shape and the contouring of the pump housing's variable cross-section inner cavity and straight nozzle inner hole are achieved through stamping using a stepped mandrel 3. The single-sided nozzle 14 is formed by punching holes in the outer die ring.

[0069] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The embodiments described above merely illustrate several implementations of the present invention and should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for near-net-shape forming of the main pump casing of a wet-wound motor, characterized in that, Includes the following steps: S1. The pump casing blank is upset and drawn multiple times until it reaches the set state; S2. Place the pump casing blank on the lower mold and use a stepped mandrel to stamp the pump casing blank to achieve the straight nozzle shape of the pump casing, the variable cross-section inner cavity of the pump casing and the inner hole of the straight nozzle. S3. Perform rotary upsetting on the pump casing blank; S4. After rotating the pump casing blank by an angle, place it on the lower anvil to achieve single-sided nozzle forming of the pump casing; Step S3 includes: S31. An upper mold ring is fixed on the lower mold for shaping, and the upper mold ring is sleeved on the outside of the pump housing blank. S32. Use a wide anvil and turntable fixture to rotate and upset the punched pump casing blank to fill the upper die ring; Step S4 includes: S41. After rotating the pump casing blank with the upper mold ring, the lower mold and the stepped core rod as a whole by 90°, place it in the arc-shaped groove of the lower anvil. S42. The upper sidewall of the pump housing blank is extruded by the punch through the through hole opened on one side of the outer wall of the upper die ring to form a single-sided nozzle. Step S1 includes: S11. Upset the pump casing blank to a height H1, and then forcefully draw it to a length D1. S12. Continue to upset the pump casing blank to a height H2, then draw it with strong pressure to a length D2, and then cut the handle and bottom with gas cutting. The height H1 is greater than the height H2, and the length D1 is less than the length D2. S13. Upset the pump casing blank to a set state; In step S2, the lower mold includes a lower mold body, and a forming hole is opened at the center of the lower mold body; the stepped core rod includes two shafts connected coaxially, the two shafts have different diameters and have a draft angle between them; The stepped mandrel can penetrate the interior of the pump housing blank and squeeze the bottom of the pump housing blank into the mortise for forming. The inner cavity size of the pump housing is the size of the large end of the stepped mandrel.

2. The near-net-shape forming method for the main pump casing of a wet-wound motor as described in claim 1, characterized in that, The outer wall of the upper mold ring is flush with the outer wall of the lower mold.

3. The near-net-shape forming method for the main pump casing of a wet-wound motor as described in claim 2, characterized in that, In step S4, the outer wall of the upper mold ring and the outer wall of the lower mold conforming to the arc-shaped groove cooperate with each other.

4. The near-net-shape forming method for the main pump casing of a wet-wound motor as described in claim 3, characterized in that, The punch includes a head and a punch rod connected to each other, the outer diameter of the punch rod being adapted to the inner diameter of the single-sided nozzle.

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