Casting process method of ultra-large propeller blade fillet shrinkage-proof cavity

Abstract

According to the casting process method for the ultra-large propeller blade fillet shrinkage-proof cavity, the outer side of a propeller hub of a propeller is annularly provided with blades, a dead head is arranged above the large-diameter end of the propeller hub, a feeding channel is arranged between the outer side of the upper end of the propeller hub and the dead head, the hot pitch circle of the outer side of the feeding channel and the hot pitch circle of the inner side of the propeller hub are A, and the hot pitch circle of the outer side of the feeding channel is B; the technological method has the advantages of being high in feeding efficiency, convenient to operate, high in casting quality and the like, the quality of the roots of the blades is good by additionally arranging a patch on the propeller hub, 100% no-fillet shrinkage cavity of a large propeller is achieved, the casting quality is improved, and manual operation is easy; the operation is convenient.

Description

Technical Field

[0001] The present invention belongs to the technical field of propeller blade casting technology, and specifically relates to a casting process method for preventing shrinkage holes in rounded corners of super-large propeller blades. Background Art

[0002] As we all know, ocean-going ships specifically refer to ships that are approved by my country to participate in international route operations and engage in ocean-going transportation. The ships can navigate by relying on propellers. Propellers are devices that convert the engine's rotational power into propulsion force by rotating blades in the air or water. They have been widely used in the field of ship power.

[0003] With the promotion of "energy conservation and carbon reduction", large ships have become lighter and many early ships have undergone energy-saving modifications, with propellers being an important part of the process.

[0004] The direction of propeller modification is to improve propulsion efficiency, reduce pulse vibration, and reduce starting load, so the modified propellers are generally large in diameter and small in hub, and the front end of the hub is farther from the blade. Because the hub is small and thin, and the shrinkage compensation distance is farther, the riser and hub are cooled first during propeller casting, and the blade fillet is cooled later, which violates the sequential solidification of the casting, so the blade fillet is very likely to produce shrinkage holes and shrinkage. Summary of the invention

[0005] In order to solve the above problems, this paper proposes a casting process method for preventing shrinkage holes in rounded corners of super-large propeller blades. A blade is provided in a ring shape on the outer side of the propeller hub, and a riser is provided above the large-diameter end of the hub. A shrinkage compensation channel is provided between the outer side of the upper end of the hub and the riser. The thermal pitch circle between the outer side of the shrinkage compensation channel and the inner side of the hub is A, and the thermal pitch circle between the rounded corners of the blades and the inner side of the hub is B. This process method has the advantages of high shrinkage compensation efficiency, convenient operation, and high casting quality. By adding subsidies to the hub, the quality of the blade root is good, achieving 100% rounded shrinkage hole-free large propellers, improving the casting quality, and simple operation for workers; the operation is convenient.

[0006] The specific casting process of the propeller is as follows: making a mold of a propeller hub and blades; adding a feeding channel in an annular thickening manner on the outer side of the large diameter of the upper end of the hub; the feeding channel is gradually expanded from bottom to top to thicken and widen the wall thickness of the hub at the upper end of the blade, so that the thermal pitch circle ratio of the feeding channel and the blade is A / B=0.9-1.1; then a riser is arranged on the upper end surface of the feeding channel and the hub, and an insulation layer is arranged on the outer side of the riser, and the inner surface of the insulation layer is flush with the outer surface of the feeding channel; after unpacking, the mold can be repaired and painted, and then the mold can be baked and poured; during the pouring process, the feeding channel is used to improve the feeding effect of the molten metal, and the hub is supplemented and the root of the blade is strengthened; finally, after the pouring is completed, the feeding channel is removed to complete the casting of the propeller.

[0007] The hub is in the shape of a tapered conductive cylinder, with the upper end of the hub being the large diameter end and the lower end of the hub being the small diameter end. A number of blades are equidistantly arranged in a ring on the outer side of the middle part of the hub. A fillet with an arc transition is provided at the connection between the root of the blade and the outer side of the hub. The fillet of the blade and the thermal node circle on the inner side of the hub are inscribed circles tangent to the fillet and the inner edge at three points. The interior of the blade is interconnected with the interior of the shrinkage feeding channel. The hub and the blade are an integral casting. In order to ensure that the root of the blade is fully connected to the outer side of the hub, the root of the blade is connected to the hub in an arc transition manner, thereby increasing the connection strength between the blade and the hub and the overall quality of the blade.

[0008] The shape of the feeding channel is an annular external casting channel, the upper end of the feeding channel is flush with the upper end of the hub, the lower end of the feeding channel is connected to the root fillet of the blade, the inner diameter of the feeding channel is connected to the outer diameter of the hub, the hot pitch circle of the outer side of the feeding channel and the inner side of the hub is an inscribed circle tangent to the three points of the outer side, the inner side and the upper side. According to the physical properties of the copper alloy, the hub is increased to increase the wall thickness of the hub at the upper end of the blade, and the feeding channel is gradually expanded from bottom to top to ensure the smooth flow of the feeding channel, so as to improve the feeding effect of the molten metal.

[0009] The shape of the riser is an outward-expanding cup-shaped casting riser, and an insulating layer is provided on the outer annular surface of the riser. The inner diameter of the bottom end of the insulating layer is flush with the outer diameter of the top end of the feeding channel. The large-diameter riser not only includes the upper end of the hub, but also includes the feeding channel, thereby ensuring the casting effect of the feeding channel, and also ensuring that the insulating layer is arranged on the outside of the feeding channel, thereby ensuring the insulating effect of the riser.

[0010] Beneficial effects:

[0011] This process method has the advantages of high shrinkage compensation efficiency, easy operation, and high casting quality. By adding compensation to the hub, the root quality of the blade is good, achieving 100% rounded shrinkage hole-free for large propellers, improving the casting quality, and is simple for workers to operate and easy to operate.

[0012] The hub and the blade are an integral casting. In order to ensure that the root of the blade is fully connected to the outside of the hub, the root of the blade is connected to the hub in an arc transition manner, thereby increasing the connection strength between the blade and the hub and the overall quality of the blade.

[0013] According to the physical properties of copper alloy, the hub is increased to thicken and widen the wall thickness of the hub at the upper end of the blade, so as to form a feeding channel that is gradually expanded from bottom to top to ensure the smooth flow of the feeding channel and improve the feeding effect of the molten metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a schematic diagram of a casting cross section of a casting process method for preventing shrinkage holes at rounded corners of a super-large propeller blade;

[0015] In the figure; 1. hub, 2. blade, 3. feeding channel, 4. riser, 5. insulation layer. DETAILED DESCRIPTION

[0016] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0017] Hub 1, blades 2, feeding channel 3, riser 4, thermal insulation layer 5.

[0018] like Figure 1 As shown;

[0019] The hub 1 is in the shape of a conical conduction cylinder, the upper end of the hub 1 is a large diameter end, the lower end of the hub 1 is a small diameter end, a plurality of blades 2 are arranged in an annular manner at equal intervals on the outer side of the middle of the hub 1, the root of the blade 2 is connected to the outer side of the hub 1 with a rounded corner with an arc transition, the rounded corner of the blade 2 and the hot section circle of the inner side of the hub 1 are the inscribed circles of the three points tangent to the rounded corner and the inner edge, the inside of the blade 2 is connected to the inside of the shrinkage feeding channel 3, the shape of the shrinkage feeding channel 3 is an annular external casting channel, and the shrinkage feeding channel 3 The upper end of the feeding channel 3 is connected to the upper end of the hub 1 and is flush with each other, the lower end of the feeding channel 3 is connected to the root fillet of the blade 2, the inner diameter of the feeding channel 3 is connected to the outer diameter of the hub 1, the outer side of the feeding channel 3 and the inner side of the hub 1 are thermal nodal circles that are tangent to the outer side, the inner side and the upper side at three points, the shape of the riser 4 is an outward-expanding cup-shaped casting riser 4, and the outer annular surface of the riser 4 is provided with an insulation layer 5, and the bottom inner diameter of the insulation layer 5 is flush with the top outer diameter of the feeding channel 3.

[0020] Implementation examples;

[0021] a. Making a mold for the hub 1 and blades 2 of the propeller;

[0022] b. Adding a feeding channel 3 in an annular thickened manner on the outer side of the large diameter of the upper end of the hub 1;

[0023] c. The wall thickness of the hub 1 at the upper end of the blade 2 is thickened and widened by gradually expanding the feeding channel 3 from bottom to top, so that the thermal pitch circle ratio of the feeding channel 3 and the blade 2 is A / B=0.9-1.1;

[0024] d. Then, a riser 4 is provided on the upper end surface of the feeding channel 3 and the hub 1, and a thermal insulation layer 5 is provided on the outer side of the riser 4, and the inner side surface of the thermal insulation layer 5 is flush with the outer side surface of the feeding channel 3;

[0025] e. After unpacking, shape and paint can be applied before baking and pouring;

[0026] f. During the pouring process, the shrinkage channel 3 is used to improve the shrinkage effect of the molten metal, and the hub 1 is supplemented and the root of the blade 2 is strengthened;

[0027] g. Finally, after the pouring is completed, the shrinkage feeding channel 3 is removed to complete the casting of the propeller.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A casting process for preventing shrinkage holes at rounded corners of super-large propeller blades, wherein the outer side of the propeller hub is provided with blades in an annular shape, and a riser is provided above the large-diameter end of the hub, characterized in that: A feeding channel is provided between the outer side of the upper end of the hub and the riser, the outer side of the feeding channel and the inner side of the hub have a thermal pitch circle A, the fillet of the blade and the inner side of the hub have a thermal pitch circle B, and the specific casting process of the propeller is as follows; a. Making molds for propeller hubs and blades; b. Add a feeding channel in an annular thickened manner on the outer side of the large diameter of the upper end of the hub; c. The wall thickness of the hub at the upper end of the blade is thickened and widened by gradually expanding the feeding channel from bottom to top, so that the thermal pitch circle ratio of the feeding channel and the blade is A / B = 0.9-1.1; d. Then, a riser is provided on the upper end surface of the feeding channel and the hub, and a thermal insulation layer is provided on the outer side of the riser, and the inner surface of the thermal insulation layer is flush with the outer surface of the feeding channel; e. After unpacking, shape and paint can be applied before baking and pouring; f. During the pouring process, the shrinkage channel is used to improve the shrinkage effect of the molten metal, and the hub is supplemented and the root of the blade is strengthened; g. Finally, after pouring is completed, the shrinkage channel is removed to complete the casting of the propeller.

2. The casting process for preventing shrinkage holes in fillet corners of super-large propeller blades according to claim 1 is characterized in that: The hub is in the shape of a conical conductive cylinder, the upper end of the hub is a large diameter end, the lower end of the hub is a small diameter end, and a plurality of blades are equidistantly arranged in an annular manner on the outer side of the middle of the hub.

3. The casting process for preventing shrinkage holes in fillet corners of super-large propeller blades according to claim 1, characterized in that: The root of the blade is connected to the outer side of the hub with a fillet of arc transition. The fillet of the blade and the thermal node circle of the inner side of the hub are inscribed circles tangent to the fillet and the inner edge at three points. The interior of the blade is connected to the interior of the shrinkage channel.

4. The casting process for preventing shrinkage holes in fillet corners of super-large propeller blades according to claim 1, characterized in that: The feeding channel is in the shape of an annular external casting channel, the upper end of the feeding channel is flush with the upper end of the hub, the lower end of the feeding channel is connected to the root fillet of the blade, the inner diameter of the feeding channel is connected to the outer diameter of the hub, and the thermal node circle of the outer side of the feeding channel and the inner side of the hub is an inscribed circle tangent to the three points of the outer side edge, the inner side edge and the upper end edge.

5. The casting process for preventing shrinkage holes in fillet corners of super-large propeller blades according to claim 1, characterized in that: The shape of the riser is an outward-expanding cup-shaped casting riser, and an insulating layer is arranged on the outer annular surface of the riser. The inner diameter of the bottom end of the insulating layer is flush with the outer diameter of the top end of the feeding channel.

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