A method of milling a ship propeller

Abstract

The present application relates to a kind of milling methods for ship propeller, prepare the required spindle semi-finished product of spindle, blade semi-finished product, the diameter of spindle semi-finished product is same with the diameter of spindle finished product, the length of spindle semi-finished product is greater than the length of spindle finished product, the size of blade semi-finished product is greater than the size of blade finished product, then the prepared spindle semi-finished product, blade semi-finished product is welded to form propeller semi-finished product, and positioning hole is processed in the long axis direction of spindle semi-finished product side, then the propeller semi-finished product after welding is sent to the special milling system and is milled, the milling of propeller semi-finished product is completed.The milling method of the present application adopts the mode of welding first and then milling, and realizes accurate milling through the cooperation of special milling system, and the angle between the spanwise direction of milled blade and the backward extension line of spindle is 50° only once milling, with high machining precision and convenient processing.

Description

Technical Field

[0001] This invention relates to the field of ship propeller manufacturing, specifically a milling method for ship propellers. Background Technology

[0002] A ship's propulsion system is an energy converter within its propulsion mechanism. It transforms the power generated by the engine into thrust, overcoming the resistance of the water and propelling the ship forward. The most common type is the propeller, but other types include paddle wheels, waterjet propulsion, jet propulsion, ducted propulsion, and rotary propulsion. In a broader sense, propulsion systems also include poles, oars, rudders, towlines, and sails that rely on human or wind power to propel a ship. Modern transport ships mostly employ reactive propulsion, with propellers being the most widely used.

[0003] Currently, existing propeller blades rotate primarily in a plane perpendicular to the shaft, resulting in large outer diameters, significant drag, particularly pressure drag and form drag. Furthermore, their large cross-sectional area necessitates substantial lateral space for installation. Based on this, patent CN105151258B proposes a cylindrical conical impeller marine propulsion system, comprising a main shaft, a support frame, a conical impeller, and a cylindrical casing. The main shaft is mounted on the support frame via bearings. The conical impeller includes a front disc, a rear ring, and several uniformly distributed identical blades. The blades have airfoil-shaped cross-sections. The roots of all blades are mounted on the front disc, and the tips of all blades are mounted on the rear ring. The angle between the blade's extension direction and the rearward extension line of the main shaft is acute. The front disc of the conical impeller is connected to the main shaft. The main shaft is located in front of the conical impeller, and power is input from the main shaft. The conical impeller is entirely within the cylindrical casing. Power is transmitted through the main shaft to drive the conical impeller, drawing water from the front into the cylindrical outer casing and then expelling it from the rear. The propeller in this patent is highly efficient, requiring a much smaller outer diameter and less drag compared to traditional propeller propellers for the same thrust.

[0004] The main challenge in manufacturing the aforementioned propeller lies in the blades. After machining, it is crucial to ensure that the angle between the blade's hypotenuse and the rearward extension of the main shaft is 50° after the blade is connected to the main shaft. The current manufacturing method involves first machining the main shaft and blades separately, and then welding the blades to the main shaft. This method is affected by various factors, such as the out-of-roundness of the main shaft's circumference, the parallelism of the blade-main shaft connection surface, and the thickness of the weld. Consequently, the angle between the blade's hypotenuse and the main shaft after connection may not reach 50°, resulting in low machining accuracy. This necessitates secondary adjustments, which is extremely troublesome. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a milling machining method for ship propellers with high machining accuracy.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: a milling method for a ship propeller, the propeller including a main shaft and several blades connected to the outer circumference of the main shaft, the blades having an airfoil-shaped cross-section, and the blades having an angle of 50° between their extension direction and the rearward extension line of the main shaft. The innovation lies in that the milling method includes the following steps:

[0007] S1: First, prepare the semi-finished spindle and blade products required for machining the spindle and blades. The diameter of the semi-finished spindle is the same as the diameter of the finished spindle, the length of the semi-finished spindle is greater than the length of the finished spindle, and the size of the semi-finished blade is greater than the size of the finished blade.

[0008] S2: Then, the prepared main shaft semi-finished product and blade semi-finished product are welded together to form the propeller semi-finished product, and a positioning hole is machined on one side of the main shaft semi-finished product in the long axis direction.

[0009] S3: The welded thruster semi-finished product is then sent to a dedicated milling system for milling. The dedicated milling system includes...

[0010] The feeding area, milling area, and discharging area are set up sequentially.

[0011] The conveying unit is used to realize the flow of workpieces between the feeding area, the milling processing area, and the discharging area. It includes at least a conveyor belt and a conveyor motor. Several workpiece placement seats are installed on the conveyor belt and arranged in parallel along the conveying direction of the conveyor belt. The workpiece placement seat includes a movable seat and a fixed seat. The movable seat and the fixed seat are in rolling engagement. A vertically arranged positioning column for accommodating the semi-finished spindle assembly is also provided on the upper surface of the movable seat.

[0012] The milling unit, located in the milling processing area, includes a milling base, a milling assembly for milling the workpiece, a clamping assembly for clamping the workpiece, a calibration assembly for calibrating the initial position of the workpiece, and a rotary assembly for driving the movable seat to rotate.

[0013] The detection control unit includes a photoelectric sensor for detecting the presence of a workpiece in the milling area, a camera for real-time monitoring of the workpiece in the milling area, a displacement sensor for detecting the vertical movement of the milling assembly, and a controller for control. The photoelectric sensor, camera, and displacement sensor are all connected to the input terminal of the controller, and the output terminal of the controller is connected to the conveyor motor, calibration assembly, milling assembly, and rotary assembly to control the operation of the conveyor motor, calibration assembly, milling assembly, and rotary assembly.

[0014] The welded semi-finished propeller workpiece is placed on the workpiece placement seat by hand, and the semi-finished propeller workpiece is moved between the feeding area, milling area and discharge area by the conveyor belt;

[0015] S4: The controller sends a signal to the conveyor motor, which starts the conveyor belt and drives the semi-finished product from the feeding area to the milling processing area.

[0016] S5: The photoelectric sensor detects whether there is a pusher semi-finished workpiece in the milling area, and the photoelectric sensor transmits the signal to the controller. If a pusher semi-finished workpiece is detected to have reached the specified position, proceed to step S6; if no pusher semi-finished workpiece is detected to have reached the specified position, repeat step S5.

[0017] S6: The controller sends a signal to the conveyor motor, which stops the conveyor belt from working. The camera takes a picture of the semi-finished pusher and sends the picture to the controller. The controller judges whether the position of the semi-finished pusher needs to be calibrated based on the received image data. If calibration is required, proceed to step S7; otherwise, proceed to step S8.

[0018] S7: The controller sends a signal to the calibration component, which drives the propeller semi-finished product to rotate a certain angle, so that the first blade semi-finished product of the propeller semi-finished product rotates to the required processing position. After rotating to the position, the controller controls the calibration component to stop the calibration.

[0019] S8: The controller sends a signal to the milling component, which then performs milling on the semi-finished blade. The displacement sensor detects the movement position of the milling component and transmits the detected position signal to the controller. After receiving the position signal, the controller determines whether the milling component has milled to the correct position. If it has, the process proceeds to step S9. If it has not, step S8 is repeated.

[0020] S9: The milling component returns to its original position, and the camera then takes pictures of the semi-finished pusher and sends the pictures to the controller. The controller judges whether all the semi-finished blades have been milled based on the received image data. If not, proceed to step S10. If all the milling has been completed, proceed to step S11.

[0021] S10: The controller sends a signal to the rotating component, which drives the movable seat to rotate by a fixed angle, thereby causing the propeller semi-finished product to rotate by a corresponding fixed angle, so that the next blade semi-finished product of the propeller semi-finished product rotates to the processing position, and repeats step S8 to perform milling processing on the blade semi-finished product.

[0022] S11: The controller sends a signal to the conveyor motor, which starts the conveyor belt to work and move the milled pusher semi-finished product from the milling area to the discharge area, thus completing the milling process of the pusher semi-finished product.

[0023] Furthermore, the conveying unit includes a first conveying bracket and a second conveying bracket, with the first conveying bracket located on the feeding side of the milling base and the second conveying bracket located on the discharging side of the milling base. An annular conveyor belt is installed on the first and second conveying brackets, and several workpiece placement seats arranged in parallel along the conveying direction of the conveyor belt are installed on the conveyor belt. Each workpiece placement seat includes a movable seat and a fixed seat arranged vertically. The fixed seat is directly fixed to the conveyor belt, and the movable seat and the fixed seat are in rolling engagement. A vertically arranged positioning post for accommodating the semi-finished spindle assembly is also provided on the upper surface of the movable seat.

[0024] The milling unit includes a milling base, a milling assembly, a clamping assembly, a calibration assembly, and a rotation assembly;

[0025] The milling base includes a milling bracket and a machining base plate mounted on the milling bracket, the machining base plate being located within the conveyor belt;

[0026] The milling assembly includes a milling seat and a milling cutter mounted on a milling support. The milling seat includes a vertically arranged first milling seat and a second milling seat. The first milling seat is directly fixed to the milling support. A pair of parallel guide rails are also installed on the side of the first milling seat. Both guide rails are inclined, and the angle between the upward extension line of the guide rail and the vertical plane is 50°. A slider that cooperates with the guide rail is installed on the side of the second milling seat. A lead screw is also provided between the two guide rails. A lead screw nut that cooperates with the lead screw is also installed on the second milling seat. The lead screw is driven to rotate by a motor mounted on the first milling seat, which drives the second milling seat to reciprocate along the guide rail. The milling cutter is mounted on the second milling seat and is driven to rotate by a milling motor mounted on the second milling seat.

[0027] The clamping assembly includes a clamping plate disposed above the processing base plate. The clamping plate is driven by a clamping cylinder to move closer to or away from the processing base plate, and the clamping plate and the clamping cylinder are movably connected.

[0028] The calibration assembly includes a calibration motor and a calibration gear. The calibration motor is mounted on a milling bracket, and the calibration gear is connected to the output end of the calibration motor. A toothed structure that meshes with the calibration gear is also provided on the outer wall of the movable seat. The calibration gear is located on one side of the machining base plate.

[0029] The rotating assembly includes a rotary motor and a rotary gear. The rotary motor is mounted on a milling bracket, and a rotary gear is connected to the output end of the rotary motor. The rotary gear meshes with the toothed structure of the movable seat, and the rotary gear is located on the other side of the machining base plate.

[0030] Furthermore, the rolling fit between the movable seat and the fixed seat is specifically as follows: a first groove is formed at the bottom of the movable seat, the first groove is T-shaped, a first protrusion is connected to the top of the fixed seat and embedded in the first groove, the first protrusion is T-shaped, and a first planar bearing is also provided between the first protrusion and the first groove.

[0031] Furthermore, the connection between the clamping plate and the clamping cylinder is as follows: a second groove is opened at the top of the clamping plate to accommodate the piston rod of the clamping cylinder, the second groove is in the shape of an inverted T, a section of the piston rod of the clamping cylinder that is embedded in the second groove is also in the shape of an inverted T, and a second planar bearing is also provided between the piston rod of the clamping cylinder and the second groove.

[0032] The advantages of this invention are: the milling method of this invention adopts the method of welding first and then milling, and achieves precise milling with the cooperation of a dedicated milling machining system. Only one milling operation is needed to ensure that the angle between the extension direction of the milled blade and the backward extension line of the spindle is 50°, resulting in high machining accuracy and convenient machining.

[0033] In the design of the dedicated milling system, the conveyor unit utilizes a workpiece placement seat on the conveyor belt to transport the semi-finished propeller components, thus achieving fixed-point conveying and preventing relative displacement between the semi-finished propeller components and the conveyor belt during transport. Furthermore, the workpiece placement seat employs a combination of movable and fixed seats, enabling both placement and rotation of the semi-finished propeller components. This facilitates the use of the same milling assembly to mill all the blade semi-finished components. The positioning pins of the movable seat serve to position the semi-finished propeller components relative to the movable seat, preventing relative movement during transport.

[0034] The milling unit is designed with the cooperation of milling components, clamping components, calibration components and rotation components to realize the clamping, calibration and rotation operations of the propeller semi-finished product, which provides a foundation for the subsequent automatic milling processing of the propeller semi-finished product.

[0035] The rolling fit between the movable seat and the fixed seat is achieved by using the first groove, the first protrusion, and the first plane bearing. This not only connects the movable seat and the fixed seat but also enables the relative rotation of the movable seat relative to the fixed seat, providing a foundation for the rotation during the subsequent milling process of the semi-finished propeller.

[0036] The connection between the clamping plate and the clamping cylinder is achieved by using a second groove and a second plane bearing to connect with the piston rod of the clamping cylinder. This not only connects the piston rod to the clamping plate but also enables relative rotation between the clamping plate and the piston rod, providing a foundation for rotation during the subsequent milling process of the propeller semi-finished product. Attached Figure Description

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0038] Figure 1 This is a schematic diagram of the milling system specifically used in this invention.

[0039] Figure 2 This is a schematic diagram showing the connection between the movable seat and the fixed seat in this invention.

[0040] Figure 3 This is a schematic diagram of the cooperation between the first milling base and the second milling base in this invention.

[0041] Figure 4 This is a schematic diagram showing the connection between the clamping plate and the clamping cylinder in this invention.

[0042] Figure 5 This is a schematic diagram showing the cooperation between the movable seat, the calibration component, and the rotation component in this invention. Detailed Implementation

[0043] The following embodiments are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the invention to the scope of the embodiments described.

[0044] The propulsion unit includes a main shaft and several blades connected to the outer circumference of the main shaft. The blades have an airfoil-shaped cross-section, and the angle between the blade's span direction and the rearward extension line of the main shaft is 50°.

[0045] The milling method for ship propellers of the present invention is achieved through the following steps:

[0046] S1: First, prepare the semi-finished spindle and blade products required for processing the finished spindle and blade products. The semi-finished spindle and finished spindle are both cylindrical, and the diameter of the semi-finished spindle is the same as that of the finished spindle. The length of the semi-finished spindle is greater than that of the finished spindle. The finished blade is a right-angled trapezoidal plate, and the right-angled waist of the finished blade is fixed to the outer wall of the finished spindle. The angle between the extension direction of the inclined waist of the finished blade and the extension line of the finished spindle is 50°. The semi-finished blade is a rectangular plate, and the size of the semi-finished blade is greater than that of the finished blade.

[0047] S2: Then, the prepared main shaft semi-finished product and blade semi-finished product are welded to form the propeller semi-finished product, and a positioning hole is machined on one side of the main shaft semi-finished product in the long axis direction. The positioning hole is a cylindrical hole and is located in the middle of the main shaft semi-finished product.

[0048] S3: The welded thruster semi-finished product is then sent to a dedicated milling system for milling.

[0049] like Figures 1-5 As shown in the schematic diagram, the dedicated milling system includes

[0050] The feeding area 1, milling processing area 2, and discharging area 3 are set up in sequence.

[0051] The conveying unit is used to realize the flow of workpieces between the feeding area 1, the milling processing area 2, and the discharge area 3. It includes a first conveying bracket set at the feeding area 1 and a second conveying bracket set at the discharge area 3. A ring conveyor belt 4 is installed on the first conveying bracket and the second conveying bracket. The conveyor belt 4 is driven by a conveying motor installed on the first conveying bracket or the second conveying bracket. Several workpiece placement seats 5 are installed on the conveyor belt 4 and arranged in parallel along the conveying direction of the conveyor belt 4.

[0052] like Figure 2 As shown in the schematic diagram, the workpiece placement seat 5 includes a movable seat 51 and a fixed seat 52 arranged vertically. The fixed seat 52 is directly fixed to the upper end surface of the conveyor belt 4. Both the movable seat 51 and the fixed seat 52 are disc-shaped, and the size of the movable seat 51 is larger than that of the fixed seat 52. This design allows the size of the fixed seat 52 installed on the conveyor belt 4 to be smaller, which is convenient for cooperating with the ring-shaped conveyor belt 4 and realizing the movement of the workpiece placement seat 5 along a ring track.

[0053] The movable seat 51 and the fixed seat 52 are in a rolling engagement. Specifically, the movable seat 51 has a first groove at its bottom end, which is T-shaped. A first protrusion 53, also T-shaped, is connected to the top of the fixed seat 52 and embedded in the first groove. Two first planar bearings 54 are positioned between the first protrusion 53 and the first groove, located on the upper and lower sides of the first protrusion 53 respectively. These two bearings allow the movable seat 51 to rotate stably relative to the first protrusion 53. This rolling engagement between the movable seat 51 and the fixed seat 52, utilizing the first groove, the first protrusion 53, and the first planar bearings 54, not only connects the movable seat 51 to the fixed seat 52 but also enables relative rotation of the movable seat 51 relative to the fixed seat 52, providing a foundation for subsequent rotation during the milling process of the semi-finished propeller.

[0054] A vertically positioned positioning post 55 for holding the semi-finished spindle assembly is also provided on the upper surface of the movable seat 51. When placing the semi-finished spindle assembly, the positioning hole of the semi-finished spindle assembly is aligned with the positioning post 55, and the semi-finished spindle assembly is placed directly on the movable seat 51 to achieve the placement of the pusher semi-finished assembly.

[0055] The milling unit located in the milling processing area 2 includes a milling base, a milling assembly for milling the semi-finished propeller workpiece, a clamping assembly for clamping the semi-finished propeller workpiece, a calibration assembly for calibrating the initial position of the semi-finished propeller workpiece, and a rotating assembly for driving the movable seat 51 to rotate.

[0056] The milling base includes a milling bracket 6 and a machining base plate 61 mounted on the milling bracket 6. The milling bracket 6 is a cuboid frame structure welded together by several horizontal bars, vertical bars and vertical bars. The milling bracket 6 is located between the first conveying bracket and the second conveying bracket, and the side of the milling bracket 6 closer to the first conveying bracket is the feeding side, and the side of the milling bracket 6 closer to the second conveying bracket is the discharging side. The machining base plate 61 is located inside the conveyor belt 4.

[0057] The milling assembly includes a milling seat 7 mounted on a milling bracket 6 and a milling cutter, such as... Figure 3 As shown in the schematic diagram, the milling base 7 includes a vertically arranged first milling base 71 and a second milling base 72. The first milling base 71 is directly fixed to the milling bracket 6 by bolts. A pair of parallel guide rails 73 are also installed on the side of the first milling base 71. Both guide rails 73 are inclined, and the angle between the upward extension line of the guide rails 73 and the vertical plane is 50°. A slider corresponding to the two guide rails 73 is installed on the side of the second milling base 72. A lead screw 74 is also provided on the first milling base 71 between the two guide rails 73. The two sides of the lead screw 74 are mounted on the bearing housing through the cooperation of bearings. The first milling base 71 has a lead screw 74 that is also inclined. The inclination angle of the lead screw 74 is the same as that of the guide rail 73. The second milling base 72 is also equipped with a lead screw nut that cooperates with the lead screw 74. The lead screw 74 is driven to rotate by the first motor installed on the first milling base 71, which drives the second milling base 72 to reciprocate along the long axis of the guide rail 73. The milling cutter is installed on the second milling base 72 and is driven to rotate by the milling motor installed on the second milling base 72. As the second milling base 72 tilts, it drives the milling cutter to tilt, thereby realizing the oblique milling of the blade semi-finished product.

[0058] The clamping assembly includes a clamping plate 8 disposed above the machining base plate 61. The clamping plate 8 is driven to move closer to or away from the machining base plate 61 by a clamping cylinder 81 mounted on the milling bracket 6. The clamping cylinder 81 is a pneumatic cylinder or a hydraulic cylinder, and the clamping plate 8 and the clamping cylinder 81 are movably connected.

[0059] like Figure 4 As shown in the schematic diagram, the connection between the clamping plate 8 and the clamping cylinder 81 is as follows: A second groove, shaped like an inverted T, is formed at the top of the clamping plate 8 to accommodate the piston rod of the clamping cylinder 81. The section of the piston rod embedded in this groove is also inverted T-shaped. Two second planar bearings 83 are provided between the piston rod and the second groove, located on the upper and lower sides of the section of the piston rod embedded in the groove, respectively. The connection between the clamping plate 8 and the clamping cylinder 81, using the second groove and the second planar bearings 83, connects the clamping plate 8 to the piston rod. This connection between the piston rod and the clamping plate 8 allows for relative rotation between them, providing a foundation for rotation during the subsequent milling process of the semi-finished propeller.

[0060] The calibration assembly includes a calibration motor and a calibration gear 9. The calibration motor is mounted on the milling bracket 6 via a motor mounting base. The calibration gear 9 is connected to the output end of the calibration motor. A toothed structure 56 that meshes with the calibration gear is also provided on the outer wall of the movable base 51. The calibration gear 9 is located on one side of the machining base plate 61.

[0061] The rotating assembly includes a rotary motor and a rotary gear 10. The rotary motor is mounted on the milling bracket 6 via a motor mounting base. A rotary gear 10 is connected to the output end of the rotary motor. The rotary gear 10 meshes with the tooth structure 56 of the movable seat 51. The rotary gear 10 is located on the other side of the machining base plate 61.

[0062] The detection control unit includes a photoelectric sensor for detecting the presence of a workpiece in the milling area, a camera for real-time monitoring of the workpiece in the milling area, a displacement sensor for detecting the vertical movement of the milling assembly, and a controller for control. The photoelectric sensor, camera, and displacement sensor are all connected to the input terminal of the controller. The output terminal of the controller is connected to the conveyor motor, the calibration motor of the calibration assembly, the clamping cylinder 81 of the clamping assembly, the first motor of the milling assembly, the milling motor, and the rotary motor of the rotary assembly, and is used to control the actions of the conveyor motor, the calibration assembly, the milling assembly, the clamping assembly, and the rotary assembly.

[0063] In the design of the dedicated milling system, the conveying unit utilizes a workpiece placement seat on the conveyor belt 4 to achieve fixed-point conveying of the propeller semi-finished product, thus avoiding relative displacement between the propeller semi-finished product and the conveyor belt during the conveying process. Furthermore, the workpiece placement seat employs a combination of a movable seat 51 and a fixed seat 52, enabling both placement and rotation of the propeller semi-finished product. This facilitates the use of the same milling assembly to mill all the blade semi-finished products. The positioning pin 55 of the movable seat 52 serves to position the propeller semi-finished product relative to the movable seat 52, preventing relative movement during transport. Positioning is achieved simply by embedding the positioning pin 55 into the positioning hole of the spindle semi-finished product, which is very convenient.

[0064] The milling unit is designed with the cooperation of milling components, clamping components, calibration components and rotation components to realize the clamping, calibration and rotation operations of the propeller semi-finished product, which provides a foundation for the subsequent automatic milling processing of the propeller semi-finished product.

[0065] The design of the detection and control unit employs photoelectric sensors, cameras, displacement sensors, and controllers to work in conjunction with the milling, clamping, calibration, and rotation components. This controls the automatic opening and closing of the milling, clamping, calibration, and rotation components without manual operation, reducing human intervention and providing a solid foundation for enterprise automation.

[0066] The welded semi-finished propeller workpiece is placed on the workpiece placement seat by hand, and the semi-finished propeller workpiece is moved between the feeding area 1, the milling processing area 2, and the discharge area 3 by the conveyor belt 4.

[0067] S4: The controller sends a signal to the conveyor motor. After receiving the start signal, the conveyor motor starts and drives the conveyor belt 4 to work. The conveyor belt 4 then drives the semi-finished product from the feeding area 1 to the milling processing area 2.

[0068] S5: The photoelectric sensor detects whether there is a pusher semi-finished workpiece in the milling area, and transmits the signal to the controller. If a pusher semi-finished workpiece is detected to have reached the specified position, proceed to step S6. When the pusher semi-finished workpiece reaches the specified position, the tooth structure 56 of the movable seat 51 is engaged with the calibration gear 9 and the rotating gear 10. If no pusher semi-finished workpiece is detected to have reached the specified position, repeat step S5.

[0069] S6: The controller sends a stop signal to the conveyor motor. After receiving the stop signal, the conveyor motor stops working, causing the conveyor belt 4 to stop conveying as well. After the conveyor belt 4 stops conveying, the camera takes a picture of the semi-finished pusher and sends the picture to the controller. The controller judges the received image data to determine whether the position of the semi-finished pusher needs to be calibrated. If calibration is required, proceed to step S7; otherwise, proceed to step S8.

[0070] S7: The controller sends a calibration signal to the calibration component. After receiving the signal, the calibration component starts the calibration motor, which drives the calibration gear 9 to rotate. The meshing of the calibration gear 9 with the tooth structure 56 of the movable seat 51 causes the movable seat 51 to rotate by a certain angle. The rotation of the movable seat 51 will cause the propeller semi-finished product to rotate accordingly, so that the first blade semi-finished product of the propeller semi-finished product rotates to the required processing position. After rotating to the position, the controller controls the calibration motor to stop the calibration, thus completing the calibration of the position of the propeller semi-finished product.

[0071] S8: The controller sends a signal to the milling assembly, which then performs milling on the blade semi-finished product. During milling, firstly, after receiving the signal from the controller, the clamping cylinder 81 drives the clamping plate 8 downward to clamp the pusher semi-finished product. Then, after receiving the signal from the controller, the first motor drives the lead screw 74 to rotate, causing the second milling block 72 to move downward. While the second milling block 72 is moving downward, the milling motor receives the signal from the controller and drives the milling cutter to work, thus milling the blade semi-finished product during the downward movement of the second milling block 72 to process the inclined waist of the blade semi-finished product. During the downward movement of the second milling block 72, the displacement sensor detects the downward movement position of the second milling block 72 and transmits the detected position signal to the controller. After receiving the position signal, the controller determines whether the milling assembly has milled to the correct position. If the milling is in place, proceed to step S9; otherwise, repeat step S8 to continuously mill the blade semi-finished product.

[0072] S9: The milling assembly returns to its original position, that is, the second milling base 72 moves upward under the drive of the first motor, the milling motor stops working, the milling cutter stops milling, and then the camera takes pictures of the pusher semi-finished product and sends the pictures to the controller. The controller judges whether all blade semi-finished products have been milled based on the received image data. If not, proceed to step S10. If all milling has been completed, proceed to step S11.

[0073] S10: The controller sends a rotation signal to the rotary motor of the rotary component. After receiving the rotation signal, the rotary motor starts working and drives the rotary gear 10 to rotate a certain angle. This angle is determined by the number of blade semi-finished products. The angle of each rotation is 360° / the number of blade semi-finished products. The rotation of the rotary gear 10 will drive the movable seat 51 to rotate by a corresponding fixed angle through meshing with the tooth structure 56 of the movable seat 51. This will drive the propeller semi-finished product to rotate by a corresponding fixed angle, so that the next blade semi-finished product of the propeller semi-finished product rotates to the processing position. After rotating to the position, the rotary motor stops working and repeats step S8 to perform milling processing on the next blade semi-finished product.

[0074] S11: The controller sends a start signal to the conveyor motor. After receiving the start signal, the conveyor motor starts working and drives the conveyor belt 4 to work. The conveyor belt 4 drives the milled pusher semi-finished product from the milling processing area 2 to the discharge area 3 to complete the milling processing of the pusher semi-finished product.

[0075] The semi-finished propellers from the discharge area 3 are then sent to the cutting center, where the semi-finished main shaft and blades are cut to obtain the finished propellers of the required size.

[0076] The milling method of the present invention adopts a welding-then-milling approach, and achieves precise milling with the help of a dedicated milling machining system. Only one milling operation is needed to ensure that the angle between the extension direction of the milled blade and the rearward extension line of the spindle is 50°, resulting in high machining accuracy and convenient machining.

[0077] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A milling method for a marine propeller, the propeller comprising a main shaft and several blades connected to the outer circumference of the main shaft, the blades having an airfoil-shaped cross-section, and the blades having an angle of 50° between their span direction and the rearward extension line of the main shaft, characterized in that: The milling process includes the following steps: S1: First, prepare the semi-finished spindle and blade products required for machining the spindle and blades. The diameter of the semi-finished spindle is the same as the diameter of the finished spindle, the length of the semi-finished spindle is greater than the length of the finished spindle, and the size of the semi-finished blade is greater than the size of the finished blade. S2: Then, the prepared main shaft semi-finished product and blade semi-finished product are welded together to form the propeller semi-finished product, and a positioning hole is machined on one side of the main shaft semi-finished product in the long axis direction. S3: The welded thruster semi-finished product is then sent to a dedicated milling system for milling. The dedicated milling system includes... The feeding area, milling area, and discharging area are set up sequentially. The conveying unit is used to realize the flow of workpieces between the feeding area, the milling processing area, and the discharging area. It includes at least a conveyor belt and a conveyor motor. Several workpiece placement seats are installed on the conveyor belt and arranged in parallel along the conveying direction of the conveyor belt. The workpiece placement seat includes a movable seat and a fixed seat. The movable seat and the fixed seat are in rolling engagement. A vertically arranged positioning column for accommodating the semi-finished spindle assembly is also provided on the upper surface of the movable seat. The milling unit, located in the milling processing area, includes a milling base, a milling assembly for milling the workpiece, a clamping assembly for clamping the workpiece, a calibration assembly for calibrating the initial position of the workpiece, and a rotating assembly for driving the movable seat to rotate. The milling assembly includes a milling seat and a milling cutter mounted on a milling support. The milling seat includes a vertically arranged first milling seat and a second milling seat. The first milling seat is directly fixed to the milling support. A pair of parallel guide rails are also installed on the side of the first milling seat. Both guide rails are inclined, and the angle between the upward extension line of the guide rail and the vertical plane is 50°. A slider that cooperates with the guide rail is installed on the side of the second milling seat. A lead screw is also provided between the two guide rails. A lead screw nut that cooperates with the lead screw is also installed on the second milling seat. The lead screw is driven to rotate by a motor mounted on the first milling seat, which drives the second milling seat to reciprocate along the guide rail. The milling cutter is mounted on the second milling seat and is driven to rotate by a milling motor mounted on the second milling seat. The detection and control unit includes a photoelectric sensor for detecting the presence of a workpiece in the milling area, a camera for real-time monitoring of the workpiece in the milling area, a displacement sensor for detecting the vertical movement of the milling assembly, and a controller for control. The photoelectric sensor, camera, and displacement sensor are all connected to the input terminal of the controller, and the output terminal of the controller is connected to the conveyor motor, calibration assembly, milling assembly, and rotary assembly to control the operation of the conveyor motor, calibration assembly, milling assembly, and rotary assembly. The welded semi-finished propeller workpiece is placed on the workpiece placement seat by hand, and the semi-finished propeller workpiece is moved between the feeding area, milling area and discharge area by the conveyor belt; S4: The controller sends a signal to the conveyor motor, which starts the conveyor belt and drives the semi-finished product from the feeding area to the milling processing area. S5: The photoelectric sensor detects whether there is a pusher semi-finished workpiece in the milling area, and the photoelectric sensor transmits the signal to the controller. If a pusher semi-finished workpiece is detected to have reached the specified position, proceed to step S6; if no pusher semi-finished workpiece is detected to have reached the specified position, repeat step S5. S6: The controller sends a signal to the conveyor motor, which stops the conveyor belt from working. The camera takes a picture of the semi-finished pusher and sends the picture to the controller. The controller judges whether the position of the semi-finished pusher needs to be calibrated based on the received image data. If calibration is required, proceed to step S7; otherwise, proceed to step S8. S7: The controller sends a signal to the calibration component, which drives the propeller semi-finished product to rotate a certain angle, so that the first blade semi-finished product of the propeller semi-finished product rotates to the required processing position. After rotating to the position, the controller controls the calibration component to stop the calibration. S8: The controller sends a signal to the milling component, which then performs milling on the semi-finished blade. The displacement sensor detects the movement position of the milling component and transmits the detected position signal to the controller. After receiving the position signal, the controller determines whether the milling component has milled to the correct position. If it has, the process proceeds to step S9. If it has not, step S8 is repeated. S9: The milling component returns to its original position, and the camera then takes pictures of the semi-finished pusher and sends the pictures to the controller. The controller judges whether all the semi-finished blades have been milled based on the received image data. If not, proceed to step S10. If all the milling has been completed, proceed to step S11. S10: The controller sends a signal to the rotating component, which drives the movable seat to rotate by a fixed angle, thereby causing the propeller semi-finished product to rotate by a corresponding fixed angle, so that the next blade semi-finished product of the propeller semi-finished product rotates to the processing position, and repeats step S8 to perform milling processing on the blade semi-finished product. S11: The controller sends a signal to the conveyor motor, which starts the conveyor belt to work and move the milled pusher semi-finished product from the milling area to the discharge area, thus completing the milling process of the pusher semi-finished product.

2. The method of claim 1, wherein: The conveying unit includes a first conveying bracket and a second conveying bracket. The first conveying bracket is located on the feeding side of the milling base, and the second conveying bracket is located on the discharging side of the milling base. An annular conveyor belt is installed on the first and second conveying brackets. Several workpiece placement seats are installed on the conveyor belt and arranged in parallel along the conveying direction of the conveyor belt. The workpiece placement seat includes a movable seat and a fixed seat arranged vertically. The fixed seat is directly fixed on the conveyor belt. The movable seat and the fixed seat are in rolling fit. A vertically arranged positioning post for accommodating the semi-finished spindle assembly is also provided on the upper surface of the movable seat. The milling unit includes a milling base, a milling assembly, a clamping assembly, a calibration assembly, and a rotation assembly; The milling base includes a milling bracket and a machining base plate mounted on the milling bracket, the machining base plate being located within the conveyor belt; The clamping assembly includes a clamping plate disposed above the processing base plate. The clamping plate is driven by a clamping cylinder to move closer to or away from the processing base plate, and the clamping plate and the clamping cylinder are movably connected. The calibration assembly includes a calibration motor and a calibration gear. The calibration motor is mounted on a milling bracket, and the calibration gear is connected to the output end of the calibration motor. A toothed structure that meshes with the calibration gear is also provided on the outer wall of the movable seat. The calibration gear is located on one side of the machining base plate. The rotating assembly includes a rotary motor and a rotary gear. The rotary motor is mounted on a milling bracket, and a rotary gear is connected to the output end of the rotary motor. The rotary gear meshes with the toothed structure of the movable seat, and the rotary gear is located on the other side of the machining base plate.

3. The method of claim 2, wherein: The rolling fit between the movable seat and the fixed seat is specifically as follows: a first groove is opened at the bottom of the movable seat, the first groove is T-shaped, a first protrusion is connected to the top of the fixed seat and embedded in the first groove, the first protrusion is T-shaped, and a first planar bearing is also provided between the first protrusion and the first groove.

4. The method of claim 2, wherein: The connection between the clamping plate and the clamping cylinder is as follows: a second groove is opened at the top of the clamping plate to accommodate the piston rod of the clamping cylinder. The second groove is in the shape of an inverted T. The section of the piston rod of the clamping cylinder that is embedded in the second groove is also in the shape of an inverted T. A second planar bearing is also provided between the piston rod of the clamping cylinder and the second groove.

Images