A high-precision, low-cost, uniform-wall-thickness single-screw pump hollow rotor forming equipment and process

Abstract

The present invention discloses a high-precision, low-cost, equal-wall-thickness single-screw pump hollow rotor forming device and process, comprising a forming mold, a pressure mechanism, a seamless steel pipe and a feeding mechanism, wherein the forming mold comprises an upper mold and a lower mold, a lower slide seat and an upper slide seat are installed on the upper side of the pressure mechanism, and the upper slide seat is located on the upper side of the lower slide seat, the lower mold and the upper mold are respectively fixed on one end of the lower slide seat and the upper slide seat close to each other, a rack arranged along its transverse length direction is fixed on one side of the feeding mechanism, a clamping mechanism is slidably connected to the upper end of the feeding mechanism, a second servo motor is fixed to the upper end of the base of the clamping mechanism, a gear is fixed to the output shaft end of the second servo motor, the gear and the rack are meshed for transmission, and a clamping claw for clamping the seamless steel pipe is rotatably connected to one side of the clamping mechanism. The raw materials of the present invention are widely available and low in price, the equipment requirements are simple, and the process links are few, which can greatly reduce the processing cost of the hollow rotors with thick walls such as single-screw pumps.

Description

Technical Field

[0001] The invention relates to the technical field of single screw pump component production, and in particular to high-precision, low-cost, uniform-wall-thickness single screw pump hollow rotor molding equipment and technology. Background Art

[0002] In single screw pumps, hollow rotors have advantages over solid rotors, such as light weight, material saving, and easy installation. Generally, the hollow rotor of a single screw pump of the same specification is 50%-80% lighter than a solid rotor. Since the rotor rotates eccentrically in the stator cavity, the hollow rotor can significantly reduce vibration and start-up torque, which can extend the service life of the single screw pump.

[0003] Since the rotor of a single screw pump needs to have an interference fit with the stator cavity, the interference fit amount needs to be within a suitable range, so there are high requirements for the lead accuracy, eccentricity and cross-sectional dimension accuracy of the hollow rotor. This places high demands on the molding equipment process of the equal wall thickness hollow rotor. High process requirements greatly increase the production cost. For this reason, the present invention proposes a high-precision, low-cost equal wall thickness single screw pump hollow rotor molding equipment to solve the above problems. Summary of the invention

[0004] (I) Purpose of the invention

[0005] In order to solve the technical problems existing in the background technology, the present invention proposes a high-precision, low-cost, equal-wall-thickness single-screw pump hollow rotor forming equipment. The raw materials are widely available and low-priced, the equipment requirements are simple, and the process links are few, which can greatly reduce the processing cost of single-screw pumps and other hollow rotors with equal wall thickness.

[0006] (II) Technical solution

[0007] The present invention provides a high-precision, low-cost, uniform-wall-thickness single-screw pump hollow rotor forming device, comprising a forming mold, a pressure mechanism, a seamless steel pipe and a feeding mechanism, wherein the forming mold comprises an upper mold and a lower mold, a lower slide seat and an upper slide seat are installed on the upper side of the pressure mechanism, and the upper slide seat is located on the upper side of the lower slide seat, the lower mold and the upper mold are respectively fixed on one end of the lower slide seat and the upper slide seat that are close to each other, a rack arranged along the transverse length direction of the feeding mechanism is fixed on one side, a clamping mechanism is slidably connected to the upper end of the feeding mechanism, a second servo motor is fixed to the upper end of the base of the clamping mechanism, a gear is fixed to the end of the output shaft of the second servo motor, the gear and the rack are meshed for transmission, a clamping claw for clamping the seamless steel pipe is rotatably connected to one side of the clamping mechanism, and the other end of the seamless steel pipe is located between the upper mold and the lower mold, a first servo motor is fixed to the upper end of the clamping mechanism, a synchronous pulley is connected to the end of the output shaft of the clamping mechanism, and the synchronous pulley is synchronously driven and connected with the clamping claw through a synchronous belt.

[0008] Preferably, the sides of the upper mold and the lower mold that are close to each other are both processed with cavity curved surfaces.

[0009] Preferably, the inlet end of the cavity after the upper mold and the lower mold are molded together forms a circle with a diameter of D1, and the outlet end cavity after the upper mold and the lower mold are molded together forms a circle with a diameter of D2, and D1 is larger than D2, and D1 is connected to D2 through a special smooth cavity surface.

[0010] Preferably, the circle with the diameter D1 is not concentric with the circle with the diameter D2.

[0011] Preferably, the intersection of the mold cavity and part of the parting surface or all of the parting surface has a chamfer R1 within a specific size range;

[0012] The upper mold and the lower mold can be composed of one or more molds;

[0013] After the upper mold and the lower mold are molded together, a spiral cavity identical to the single screw pump rotor is formed on one side of the outlet end, and a chamfer can be provided at the intersection of the cavity and part of the parting surface or all of the parting surface.

[0014] Preferably, the first servo motor and the second servo motor are both controlled by a numerical control system or a PLC and can be linked, and the numerical control system or the PLC control also controls the opening and closing of the lower slide seat and the upper slide seat of the pressure mechanism.

[0015] A single screw pump hollow rotor forming process using the above-mentioned device comprises the following steps:

[0016] S1. Select seamless steel pipe as the blank material of the hollow rotor, and make the surface of the seamless steel pipe smooth by turning or polishing;

[0017] S2. Clamp one end of the seamless steel pipe on the clamping mechanism, and put the other end into the cavity of the forming mold. At this time, the pressure mechanism drives the upper mold to separate from the lower mold;

[0018] S3, the CNC system controls the second servo motor and the first servo motor to drive the feeding mechanism to move forward and the clamping mechanism to rotate, so that the seamless steel pipe moves forward a short distance and rotates an angle. The distance of advancement and the angle of rotation of the seamless steel pipe make the part in the mold always move along the cavity of the upper mold and the lower mold as much as possible;

[0019] S4. After the seamless steel pipe stops moving, the numerical control system issues a command to disable the second servo motor, and the second servo motor loses its holding torque, so that the movement of the clamping mechanism on the feeding mechanism is not constrained;

[0020] S5. The numerical control system controls the lower slide and the upper slide on the upper side of the pressure mechanism to move toward each other, driving the upper and lower molds to close the mold. During the closing process, the mold gradually presses the straight seamless steel pipe into a spiral shape. Since the diameter D1 of the seamless steel pipe is gradually compressed to the spiral pipe diameter D2 during the pressing process, the seamless pipe metal undergoes radial plastic deformation. The plastic deformation process allows the metal to produce metal memory and overcome elastic deformation, so that the cross-sectional diameter and lead of the hollow rotor reach a higher precision.

[0021] S6. Since the plastic deformation process of the seamless steel pipe will generate a certain axial force and cause the seamless steel pipe outside the mold to move slightly in the axial direction, the movement of the clamping mechanism in the axial direction of the seamless steel pipe is not constrained. The clamping mechanism slides on the feeding mechanism under the axial force, thereby offsetting the adverse effects of the movement;

[0022] S7, after the relative movement of the lower slide and the upper slide drives the upper mold and the lower mold to close and reach a certain pressure, the CNC system issues a command to control the lower slide and the upper slide to move in the opposite direction and drive the upper mold and the lower mold to separate;

[0023] S8. After the upper mold and the lower mold are separated by a distance, the CNC system issues an instruction to repeat steps S3-S7. Through the repeated action, the seamless steel pipe is gradually compressed into a spiral single-screw pump hollow rotor.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] By using seamless steel pipes as raw materials, the purchase cost of raw materials can be reduced. By using upper and lower molds with special cavities, the process requirements during production can be simplified, greatly reducing the processing cost of thick-walled hollow rotors such as single-screw pumps. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a front view of a high-precision, low-cost, uniform-wall-thickness single-screw pump hollow rotor forming device proposed by the present invention;

[0027] Figure 2 A side view of an upper mold and a lower mold in a high-precision, low-cost, uniform-wall-thickness single-screw pump hollow rotor molding device proposed by the present invention;

[0028] Figure 3 This is another side view of the upper mold and the lower mold in the high-precision, low-cost, equal-wall-thickness single-screw pump hollow rotor molding equipment proposed by the present invention.

[0029] In the figure: 1 pressure mechanism, 2 lower slide seat, 3 upper slide seat, 4 upper mold, 5 lower mold, 6 seamless steel pipe, 7 clamping claw, 8 clamping mechanism, 9 first servo motor, 10 synchronous belt, 11 second servo motor, 12 gear, 13 rack, 14 feeding mechanism. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] like Figure 1-3 As shown, the present invention proposes a high-precision, low-cost, uniform-wall-thickness single-screw pump hollow rotor forming device, including a forming mold, a pressure mechanism 1, a seamless steel pipe 6 and a feeding mechanism 14, the forming mold includes an upper mold 4 and a lower mold 5, a lower slide 2 and an upper slide 3 are installed on the upper side of the pressure mechanism 1, and the upper slide 3 is located on the upper side of the lower slide 2, the lower mold 5 and the upper mold 4 are respectively fixed on the ends of the lower slide 2 and the upper slide 3 that are close to each other, a rack 13 arranged along its transverse length direction is fixed on one side of the feeding mechanism 14, and the upper end of the feeding mechanism 14 is fixed with a rack 13 arranged along its transverse length direction. A clamping mechanism 8 is slidably connected, a second servo motor 11 is fixed to the upper end of the base of the clamping mechanism 8, a gear 12 is fixed to the end of the output shaft of the second servo motor 11, the gear 12 is meshed with the rack 13 for transmission, one side of the clamping mechanism 8 is rotatably connected to a clamping claw 7 for clamping the seamless steel pipe 6, and the other end of the seamless steel pipe 6 is located between the upper mold 4 and the lower mold 5, a first servo motor 9 is fixed to the upper end of the clamping mechanism 8, a synchronous pulley is connected to the end of the output shaft of the clamping mechanism 8, and the synchronous pulley is synchronously transmitted with the clamping claw 7 through a synchronous belt 10.

[0032] In an optional embodiment, the sides of the upper mold 4 and the lower mold 5 that are close to each other are both processed with cavity curved surfaces.

[0033] In an optional embodiment, the inlet end of the cavity after the upper mold 4 and the lower mold 5 are molded together forms a circle with a diameter of D1, and the outlet end of the cavity after the upper mold 4 and the lower mold 5 are molded together forms a circle with a diameter of D2, and D1 is greater than D2, and D1 is connected to D2 through a special smooth cavity surface.

[0034] In an optional embodiment, the circle with the diameter D1 is not concentric with the circle with the diameter D2.

[0035] In an optional embodiment, the intersection of the mold cavity and a part of the parting surface or the entire parting surface has a chamfer R1 within a specific size range;

[0036] The upper mold 4 and the lower mold 5 can be composed of one or more molds;

[0037] After the upper mold 4 and the lower mold 5 are molded together, a spiral cavity identical to the single screw pump rotor is formed on one side of the outlet end, and a chamfer can be provided at the intersection of the cavity and part of the parting surface or all of the parting surface.

[0038] In an optional embodiment, the first servo motor 9 and the second servo motor 11 are both controlled by a CNC system or PLC and can be linked, and the CNC system or PLC control also controls the opening and closing of the lower slide 2 and the upper slide 3 of the pressure mechanism 1.

[0039] A single screw pump hollow rotor forming process using the above-mentioned device comprises the following steps:

[0040] S1, selecting a seamless steel tube 6 as a blank material for the hollow rotor, and polishing the seamless steel tube 6 by turning or polishing to make its surface smooth;

[0041] S2, clamp one end of the seamless steel pipe 6 on the clamping mechanism 8, and put the other end into the molding die cavity, at this time, the pressure mechanism 1 drives the upper die 4 to separate from the lower die 5;

[0042] S3, the numerical control system controls the second servo motor 11 and the first servo motor 9, drives the feeding mechanism 14 to move forward and the clamping mechanism 8 to rotate, so that the seamless steel pipe 6 moves forward a short distance and rotates an angle, and the distance of advancement and the angle of rotation of the seamless steel pipe 6 make the part in the mold always move along the cavity of the upper mold 4 and the lower mold 5 as much as possible;

[0043] S4, after the seamless steel pipe 6 stops moving, the numerical control system issues a command to disable the second servo motor 11, and the second servo motor 11 loses the holding torque, so that the movement of the clamping mechanism 8 on the feeding mechanism 14 is not constrained;

[0044] S5, the numerical control system controls the lower slide 2 and the upper slide 3 on the upper side of the pressure mechanism 1 to move toward each other, driving the upper mold 4 and the lower mold 5 to close the mold. During the closing process, the mold gradually presses the straight seamless steel pipe 6 into a spiral shape. Since the diameter D1 of the seamless steel pipe 6 is gradually compressed to the spiral pipe diameter D2 during the pressing process, the seamless pipe metal undergoes radial plastic deformation. The plastic deformation process allows the metal to produce metal memory and overcome elastic deformation, so that the cross-sectional diameter and lead of the hollow rotor reach a higher precision;

[0045] S6. Since the plastic deformation process of the seamless steel tube 6 generates a certain axial force and causes the seamless steel tube 6 outside the mold to move slightly in the axial direction, the movement of the clamping mechanism 8 in the axial direction of the seamless steel tube 6 is not constrained at this time, and the clamping mechanism 8 slides on the feeding mechanism 14 under the axial force, thereby offsetting the adverse effects of the movement;

[0046] S7, after the relative movement of the lower slide 2 and the upper slide 3 drives the upper mold 4 and the lower mold 5 to close and reach a certain pressure, the CNC system issues a command to control the lower slide 2 and the upper slide 3 to move in the opposite direction and drive the upper mold 4 and the lower mold 5 to separate;

[0047] S8. After the upper mold 4 and the lower mold 5 are separated by a distance, the numerical control system issues an instruction to repeat steps S3-S7. Through the repeated action, the seamless steel pipe 6 is gradually compressed into a spiral single-screw pump hollow rotor.

[0048] Working principle: Since the rotor of the single-screw pump needs to have an interference fit with the stator cavity, the amount of interference fit needs to be within an appropriate range, so there are high requirements for the lead accuracy, eccentricity and cross-sectional size accuracy of the hollow rotor. This places high demands on the forming equipment process of hollow rotors with equal wall thickness. High process requirements greatly increase the production cost. In this embodiment, one end of the seamless steel pipe 6 is clamped on the clamping mechanism 8, and the other end is placed in the molding mold cavity. At this time, the pressure mechanism 1 drives the upper mold 4 to separate from the lower mold 5, and the numerical control system controls the second servo motor 11 and the first servo motor 9 to drive the feeding mechanism 14 to advance and the clamping mechanism 8 to rotate, so that the seamless steel pipe 6 advances a short distance and rotates an angle. The distance of advancement of the seamless steel pipe 6 and the angle of rotation make the part in the mold always move along the cavity of the upper mold 4 and the lower mold 5 as much as possible. After the movement of the seamless steel pipe 6 stops, the numerical control system issues an instruction to disconnect the second servo motor 11, so that the movement of the clamping mechanism 8 on the feeding mechanism 14 is not constrained. The numerical control system controls the lower slide 2 and the upper slide 3 on the upper side of the pressure mechanism 1 to move toward each other, driving the upper mold 4 and the lower mold 5 to close the mold. During the closing process, the mold gradually presses the straight seamless steel pipe 6 into a spiral shape. Due to the seamless steel pipe 6 during the pressing process The diameter D1 is gradually compressed to the spiral tube diameter D2, causing the seamless tube metal to produce radial plastic deformation. The plastic deformation process will allow the metal to produce metal memory and overcome elastic deformation, so that the cross-sectional diameter and lead of the hollow rotor reach a higher precision. Since the plastic deformation process of the seamless steel tube 6 will generate a certain axial force and cause the seamless steel tube 6 outside the mold to produce a slight axial movement, at this time, the movement of the clamping mechanism 8 in the axial direction of the seamless steel tube 6 is not constrained, and the clamping mechanism 8 slides on the feeding mechanism 14 under the axial force, thereby offsetting the adverse effects of the movement. The relative movement of the lower slide 2 and the upper slide 3 drives the upper mold 4 and the lower mold 5 to close the mold and reach a certain pressure. The CNC system issues an instruction to control the lower slide 2 and the upper slide 3 to move in the opposite direction and drive the upper mold 4 and the lower mold 5 to separate. After the upper mold 4 and the lower mold 5 are separated by one end distance, the CNC system issues an instruction to repeat the seamless steel tube 6 to advance a short distance and rotate an angle and subsequent actions. Through this repeated action, the seamless steel tube 6 is gradually compressed into a spiral single-screw pump hollow rotor.

[0049] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-precision, low-cost, uniform-wall-thickness single-screw pump hollow rotor forming equipment, characterized in that: The invention comprises a forming die, a pressure mechanism (1), a seamless steel pipe (6) and a feeding mechanism (14), wherein the forming die comprises an upper die (4) and a lower die (5), a lower slide seat (2) and an upper slide seat (3) are installed on the upper side of the pressure mechanism (1), and the upper slide seat (3) is located on the upper side of the lower slide seat (2), the lower die (5) and the upper die (4) are respectively fixed on one end of the lower slide seat (2) and the upper slide seat (3) close to each other, a rack (13) arranged along the transverse length direction of the feeding mechanism (14) is fixed on one side, and a clamping mechanism (8) is slidably connected to the upper end of the feeding mechanism (14), and the clamping mechanism (8) is provided on the upper end of the feeding mechanism (14). A second servo motor (11) is fixed to the upper end of the base of the mechanism (8), a gear (12) is fixed to the end of the output shaft of the second servo motor (11), the gear (12) is meshed with the rack (13) for transmission, one side of the clamping mechanism (8) is rotatably connected to a clamping claw (7) for clamping the seamless steel pipe (6), and the other end of the seamless steel pipe (6) is located between the upper mold (4) and the lower mold (5), the upper end of the clamping mechanism (8) is fixed to the first servo motor (9), the end of the output shaft of the clamping mechanism (8) is connected to a synchronous pulley, and the synchronous pulley is synchronously connected to the clamping claw (7) through a synchronous belt (10); The upper mold (4) and the lower mold (5) are both processed with cavity curved surfaces on the sides close to each other; After the upper mold (4) and the lower mold (5) are molded together, the inlet end of the mold cavity forms a circle with a diameter of D1, and after the upper mold (4) and the lower mold (5) are molded together, the outlet end of the mold cavity forms a circle with a diameter of D2, and D1 is larger than D2, and D1 is connected to D2 through a special smooth mold cavity curved surface; The circle with a diameter of D1 is not concentric with the circle with a diameter of D2; The intersection of the mold cavity and a part of the parting surface or the whole parting surface has a chamfer R1 within a specific size range; The upper mold (4) and the lower mold (5) are composed of one or more molds; After the upper mold (4) and the lower mold (5) are molded together, a spiral cavity identical to the rotor of the single screw pump is formed on one side of the outlet end, and a chamfer is provided at the intersection of the cavity and a part of the parting surface or the entire parting surface; The first servo motor (9) and the second servo motor (11) are both controlled by a numerical control system or a PLC and can be linked, and the numerical control system or the PLC also controls the opening and closing of the lower slide seat (2) and the upper slide seat (3) of the pressure mechanism (1).

2. A single screw pump hollow rotor forming process using the device according to claim 1, characterized in that: The following steps are involved: S1. Selecting a seamless steel pipe (6) as a blank material for the hollow rotor, and polishing the seamless steel pipe (6) to make its surface smooth by turning or polishing; S2, clamping one end of the seamless steel pipe (6) on the clamping mechanism (8), and placing the other end into the cavity of the forming mold, at which time the pressure mechanism (1) drives the upper mold (4) to separate from the lower mold (5); S3, the numerical control system controls the second servo motor (11) and the first servo motor (9) to drive the feeding mechanism (14) to move forward and the clamping mechanism (8) to rotate, so that the seamless steel pipe (6) moves forward a short distance and rotates at an angle, and the distance of advancement and the angle of rotation of the seamless steel pipe (6) are such that the portion of the seamless steel pipe (6) in the mold always moves along the cavities of the upper mold (4) and the lower mold (5) as much as possible; S4, after the seamless steel pipe (6) stops moving, the numerical control system issues a command to disable the second servo motor (11), so that the second servo motor (11) loses its holding torque, and the movement of the clamping mechanism (8) on the feeding mechanism (14) is not constrained; S5, the numerical control system controls the lower slide seat (2) and the upper slide seat (3) on the upper side of the pressure mechanism (1) to move toward each other, driving the upper mold (4) and the lower mold (5) to close the mold. During the closing process, the mold gradually presses the straight seamless steel pipe (6) into a spiral shape. Since the diameter D1 of the seamless steel pipe (6) is gradually compressed to the spiral pipe diameter D2 during the pressing process, the seamless pipe metal undergoes radial plastic deformation. The plastic deformation process allows the metal to produce metal memory and overcome elastic deformation, so that the cross-sectional diameter and lead of the hollow rotor reach a higher precision; S6. Since the plastic deformation process of the seamless steel pipe (6) generates a certain axial force and causes the seamless steel pipe (6) outside the mold to move slightly in the axial direction, the movement of the clamping mechanism (8) in the axial direction of the seamless steel pipe (6) is not constrained. The clamping mechanism (8) slides on the feeding mechanism (14) under the axial force, thereby offsetting the adverse effects of the movement; S7, the relative movement of the lower slide (2) and the upper slide (3) drives the upper mold (4) and the lower mold (5) to close and reach a certain pressure, and then the numerical control system issues a command to control the lower slide (2) and the upper slide (3) to move in the opposite direction and drive the upper mold (4) and the lower mold (5) to separate; S8. After the upper mold (4) and the lower mold (5) are separated by a certain distance, the numerical control system issues an instruction to repeat steps S3-S7. Through the repeated actions, the seamless steel pipe (6) is gradually compressed into a spiral single-screw pump hollow rotor.

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