Precision casting structure of impeller

Abstract

The utility model relates to a precision casting structure of an impeller, which is characterized in that the precision casting structure comprises a sprue part, a sprue, a side runner and an impeller cavity, the sprue part is arranged above the sprue, the impeller cavity is connected to two sides of the sprue, the impeller cavity is provided with a liquid inlet opposite to the sprue, the sprue part is connected to the bottom surface of the impeller cavity through the sprue, and the side runner is connected to the bottom surface of the impeller cavity through the sprue. The sprue part is connected to the end face of the impeller cavity through the side pouring gate. The utility model aims to change the casting structure of the impeller from the original straight downward hanging structure to the horizontal hanging structure, so that the area of the horizontal cross section of the impeller cavity is obviously reduced, the influence of the buoyancy of molten metal on the structure of the impeller cavity is effectively decomposed, and the service life of the impeller cavity is prolonged. The influence of the core floating phenomenon on the impeller structure is relieved to a great extent, the production qualification rate and the process yield are improved, and economic benefits are greatly increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to precision casting technical field, especially a precision casting structure of impeller. BACKGROUND

[0002] Impeller refers to the wheel disc equipped with moving blades, in the structure of the canned motor pump, the motor rotor is directly connected with the impeller, thereby achieving the effect of no seal and no leakage, in order to reduce the failure rate of the canned motor pump, the impeller of the canned motor pump is usually integrally cast by using the lost wax method casting process, so that the impeller has excellent properties such as high temperature resistance, cavitation resistance and high strength.

[0003] The traditional impeller shell structure is mainly straight down hanging, the part made into the impeller is designed into the structure of rear cover, blade and front cover from top to bottom, the riser is arranged above the axis of the rear cover, and the side gate is arranged between the riser and the rear cover and is circumferentially distributed, thereby reducing defects such as gas hole and shrinkage hole, however, when the impeller with large diameter and narrow runner is produced, the thickness of the front cover and the rear cover of the impeller after casting is often not the same, and even the rear cover of part of the finished product appears to be transparent.

[0004] By checking the cross section of the wax tree mold and the shell produced during production, it is found that the structure size of the wax mold and the shell is relatively stable, according to the elimination method, the problem occurs in the process of pouring the metal liquid, according to the cross section analysis of the finished impeller, the reason is that when the metal liquid enters the shell, part of the shell structure is soaked in the un-solidified metal liquid, due to the great buoyancy of the metal liquid, the runner part of the shell made into the blade is forced to move upward, resulting in the core floating phenomenon that the front cover is thick and the rear cover is thin of the finished product, thereby seriously affecting the structural strength of the impeller, and causing the high rejection rate of the impeller. UTILITY MODEL CONTENTS

[0005] In order to overcome the defects in the background art, the utility model adopts the technical scheme of a precision casting structure of impeller, which comprises a sprue, a straight gate, a side gate and an impeller cavity, the sprue is arranged above the straight gate, the impeller cavity is connected to the two sides of the straight gate, the impeller cavity is provided with a liquid inlet facing away from the straight gate, the sprue is connected to the bottom surface of the impeller cavity through the straight gate, and the sprue is connected to the end surface of the impeller cavity through the side gate.

[0006] By changing the casting structure of the impeller from a straight down-hanging structure to a horizontal-hanging structure, the horizontal cross-sectional area of the impeller cavity is significantly reduced, the influence of the metal liquid buoyancy on the impeller cavity structure is effectively decomposed, the influence of the core floating phenomenon on the impeller structure is greatly relieved, the processed impeller meets the G2.5 requirement after dynamic balance test, the structure is smooth in exhaust, the internal wall thickness is uniform, the impeller cavities are symmetrically distributed on both sides of the sprue part, the structure of one out of two improves the production efficiency of the impeller, and the qualified rate of batch production is as high as 95%, the process scheme not only improves the quality, but also improves the process yield, the process yield reaches 53% for the impeller with a large diameter, and the economic benefit of the enterprise is improved.

[0007] The utility model further provides, the sprue is equipped with first runner, second runner and third runner which are connected with the impeller cavity from top to bottom.

[0008] Further, the impeller cavity comprises a front cover part, a blade part and a rear cover part connected in sequence, the liquid inlet is arranged on the front cover part, and the sprue is connected to the rear cover part through the first runner, the second runner and the third runner respectively.

[0009] By adopting the above technical scheme, the liquid inlet structure of the impeller is relatively complex, the sprue is connected to the rear cover part instead of the front cover part, so that the stability of the liquid inlet and the blade part structure is maintained, the surface roughness of the formed impeller reaches Ra3.2, and the resistance during the working of the impeller is reduced.

[0010] The utility model further provides, the center of rear cover part is equipped with cylindrical part, second runner is connected in cylindrical part, rear cover part is equipped with circular ring part towards the direction of sprue, first runner, third runner are symmetrically distributed in both sides of circular ring part.

[0011] By adopting the above technical scheme, the sprue is connected to the rear cover part through the first runner, the second runner and the third runner respectively, the number of runners is increased to reduce the pressure loss, the first runner, the second runner and the third runner are all connected to the thick wall of the impeller, the metal liquid is ensured to fill the impeller cavity sufficiently, product defects are reduced, when the total shell is made, the multi-runner structure is the air duct required in the dry shell, the total shell is beneficial to drying and the structural strength of the total shell is increased, and the manufacturing period is shortened.

[0012] The utility model further provides, the sprue part is connected to the end face of the blade part through the side runner.

[0013] By adopting the above technical scheme, the side runner and the sprue can be filled to the impeller cavity synchronously and quickly, the local overheating of the impeller cavity can be avoided, and the impeller is beneficial to forming.

[0014] The utility model further provides that the bottom of the sprue is provided with a residue accumulation part.

[0015] Further, the runner is provided with a slag accumulation part at the bottom of the third runner.

[0016] The slag accumulation part is formed at the bottom of the runner to store slag, so that the impurities in the molten metal enter the impeller cavity, thereby improving the quality of casting.

[0017] The utility model discloses a precision casting process of impeller, comprising the following steps:

[0018] S1, water -soluble core preparation: through water -soluble core mold injection molding is made water -soluble core and is ready for use,

[0019] S2, wax mold forming: two water -soluble cores are placed respectively in both sides of wax mold mold, and wax mold piece is made by molding machine, and sprue rod is set on the wax mold piece,

[0020] S3, wax mold shell preparation: the wax mold piece is soaked in the water solution, and the water -soluble core is hydrolyzed, and after complete hydrolysis, it is dried, S4, making the shell: the wax mold piece is evenly adhered to the slurry and adheres to the modeling material, and is solidified into the shell,

[0021] S5, total shell forming: repeating S4 step, making multilayer shell, wax mold is dewaxed, and after baking, the total shell of precision casting structure with impeller is formed,

[0022] S6, casting forming: the molten metal is poured into the runner part of the total shell, and flows to the impeller cavity through the straight runner and the side runner, and after casting, the workpiece is cooled,

[0023] S7, casting forming: the total shell is removed, so that the workpiece embryo with the casting port is obtained, the excess runner part is cut off, and after polishing, the final forming is obtained.

[0024] Further, in the above S2, the water -soluble core is provided with a protruding part, a fan cavity circumferentially distributed around the protruding part, and a positioning block arranged on the outer surface of the water -soluble core, and the water -soluble core is clamped on both sides of the wax mold mold.

[0025] Further, in the above S2, when the wax mold piece is made, the wax material is heated to 60±2 DEG C by the molding machine, the wax liquid is injected into the wax mold to form the wax mold piece, and the sprue rod is arranged on the wax mold piece, the injection pressure is 5MPa, and after standing for 2min, the wax mold is opened and the wax mold piece is taken out.

[0026] In the above S3, the wax mold piece is soaked in the water solution for 480min, the water -soluble core is completely hydrolyzed and air dried, and the air drying time is 120min.

[0027] In S5, the wax mold is repeatedly and uniformly adhered with the slurry and the molding material to form a six-layer shell, the wax mold is placed into a drying machine for a dewaxing treatment, the dewaxing temperature is 175 DEG C, the dewaxing time is 10 min, the baking temperature is 1100 DEG C, and the baking time is 1 h, so that the total shell with the impeller precision casting structure is formed;

[0028] Compared with the prior art, the utility model has the advantages that:

[0029] 1. The utility model discloses a casting structure of an impeller, which changes the original straight down hanging structure into a horizontal hanging structure, so that the horizontal cross-sectional area of the impeller cavity is obviously reduced, the influence of metal liquid buoyancy on the impeller cavity structure is effectively decomposed, and the influence of the core floating phenomenon on the impeller structure is greatly relieved.

[0030] 2. The utility model discloses a multi-gate structure design, which ensures that the metal liquid is fully filled, and when the total shell is manufactured, the multi-gate structure is beneficial to air drying and shortens the manufacturing period.

[0031] 3. The impeller cavity is symmetrically distributed on both sides of the gate part, the structure of one out of two improves the production efficiency of the impeller, ensures the size precision and surface quality of the impeller, is suitable for batch production, improves the production qualified rate and process yield, and greatly increases economic benefits.

[0032] 4. The shrinkage area is transferred from the original impeller interior to the straight gate, the straight gate is cut together with other gates, the overall part of the impeller is not affected by the shrinkage area, the internal structure of the valve core part is more compact, and the production qualified rate of the valve core part is improved.

[0033] The embodiments of the utility model will be further described below with reference to the drawings. DRAWINGS

[0034] Figure 1 It is a structure schematic view of the precision casting structure of the impeller of the utility model;

[0035] Figure 2 It is a sectional view of the impeller of the utility model;

[0036] Figure 3 It is a perspective view of the water-soluble core of the utility model;

[0037] Figure 4 It is a process flow chart of the utility model;

[0038] Figure 5 It is a structure schematic view of the casting structure of the traditional production impeller;

[0039] Figure 6 It is a structure schematic view of the shrinkage area of the casting structure in the utility model;

[0040] Wherein: 1 - impeller cavity, 2 - gate, 3 - straight gate, 4 - side gate, 5 - first gate, 6 - second gate, 7 - third gate, 8 - straight gate, 9 - water soluble core, 10 - liquid inlet, 11 - front cover, 12 - blade part, 13 - rear cover, 14 - cylindrical part, 15 - ring part, 16 - protruding part, 17 - impeller cavity, 18 - positioning block; DETAILED DESCRIPTION

[0041] As Figure 1 , 2 shown, the utility model provides a precision casting structure of impeller, including gate 2, straight gate 3, side gate 4 and impeller cavity 1, gate 2 is located at the top of straight gate 3, impeller cavity 1 is connected to both sides of straight gate 3, and straight gate 3 is provided with first gate 5, second gate 6 and third gate 7 connected with impeller cavity 1 from top to bottom, and impeller cavity 1 is provided with liquid inlet 10 facing away from straight gate 3, gate 2 is connected to the bottom surface of impeller cavity 1 through straight gate 3, and gate 2 is connected to the end surface of impeller cavity 1 through side gate 4.

[0042] In the embodiment, impeller cavity 1 includes front cover 11, blade part 12 and rear cover 13 connected in sequence, liquid inlet 10 is arranged at front cover 11, straight gate 3 is connected to rear cover 13 through first gate 5, second gate 6 and third gate 7 respectively, and the liquid inlet 10 of front cover 11 faces away from straight gate 3, which is beneficial to the natural formation of the structure at the liquid inlet 10.

[0043] In the embodiment, cylindrical part 14 is arranged at the center of rear cover 13, second gate 6 is connected to cylindrical part 14, rear cover 13 is provided with ring part 15 in the direction facing straight gate 3, first gate 5 and third gate 7 are symmetrically distributed on both sides of ring part 15, the number of gates is increased to ensure that the metal liquid fills impeller cavity 1 sufficiently, and when the total shell is made, the multi-gate structure is the air duct required inside the dry shell, which is beneficial to drying the total shell and shortening the manufacturing cycle.

[0044] In the embodiment, gate 2 is connected to the end surface of blade part 12 through side gate 4, side gate 4 and straight gate 3 can be filled to impeller cavity 1 synchronously and quickly, which can avoid local overheating of impeller cavity 1 and is beneficial to the molding of impeller.

[0045] In the embodiment, the bottom of straight gate 3 located at third gate 7 is provided with slag accumulation part 8, the slag accumulation part 8 is formed at the bottom of straight gate 3 to store slag, which reduces the impurities in the metal liquid from entering impeller cavity 1, thereby improving the quality of casting.

[0046] The working principle of the utility model discloses, when metal liquid pours from the pouring part 2, metal liquid flows to the impeller cavity 1 on both sides through the sprue 3 and the side sprue 4 respectively, the liquid level in the impeller cavity 1 gradually rises, the horizontal cross section area of the impeller cavity 1 is small, effectively decomposes the influence of the buoyancy of metal liquid to the total shell structure, greatly relieves the influence of the core floating phenomenon to the impeller structure.

[0047] Combining Figure 3 、 4 The utility model discloses a precision casting process of impeller, comprising the following steps:

[0048] S1, water-soluble core preparation: through water-soluble core mold injection molding is made water-soluble core 9 and is ready for use;

[0049] S2, wax mold forming: two water-soluble cores 9 are placed on both sides of the wax mold respectively, and the protruding part 16 of water-soluble core 9 faces outward, when installing, water-soluble core 9 is positioned in the wax mold through the fan cavity 17 and the positioning block 18, the wax material is heated to 60±2 DEG C by the molding machine, the wax liquid is injected into the wax mold to form a wax mold piece, and a pouring rod is arranged on the wax mold piece, the injection pressure is 5MPa, the wax mold is opened and the wax mold piece is taken out after standing for 2min.

[0050] S3, wax mold shell preparation: the wax mold piece is soaked in the water solution and stands for 480min, the water-soluble core 9 is completely hydrolyzed and air dried, and the air drying time is 120min.

[0051] S4, making the shell: the wax mold piece is uniformly adhered to the slurry and adheres to the modeling material, and is solidified and formed into a shell;

[0052] S5, total shell forming: six layers of shells are made by repeating the step S4, the wax mold is put into the drying machine for dewaxing treatment, the dewaxing temperature is 175 DEG C, the dewaxing time is 10min, the baking temperature is 1100 DEG C, and the total shell with the precision casting structure of the impeller is formed after baking for 1h;

[0053] S6, casting forming: the 1620 DEG C metal liquid after smelting is poured into the pouring part 2 of the total shell, and flows to the impeller cavity 1 through the sprue 3 and the side sprue 4, and the workpiece is cooled after casting, and the workpiece is cooled after casting for 2h;

[0054] S7, casting forming: the total shell is removed, so that the workpiece embryo with the casting port is obtained, the excess pouring part is cut off, and the final forming is carried out after polishing.

[0055] The above are the preferred embodiments of the application, not limited to the protection scope of the application, so: all equivalent changes made according to the structure, shape, principle of the application should be covered in the protection scope of the application.

Claims

1. A precision cast structure of an impeller, characterized by, The gate part, the sprue, the side gate and the impeller type cavity are included, the gate part is arranged above the sprue, the impeller type cavity is connected to the two sides of the sprue, the impeller type cavity is provided with a liquid inlet facing away from the sprue, the gate part is connected to the bottom surface of the impeller type cavity through the sprue, the gate part is connected to the end surface of the impeller type cavity through the side gate, and the bottom of the sprue is provided with a slag accumulation part.

2. A precision cast construction of an impeller according to claim 1, characterized in that: The sprue is provided with the first runner, the second runner and the third runner from top to bottom and connected to the impeller type cavity.

3. A precision cast construction of an impeller according to claim 2, characterized in that: The impeller type cavity includes the front cover part, the blade part and the rear cover part connected in sequence, the liquid inlet is arranged on the front cover part, and the sprue is connected to the rear cover part through the first runner, the second runner and the third runner.

4. A precision cast construction of an impeller according to claim 3, characterized in that: The center of the rear cover part is provided with a cylindrical part, the second runner is connected to the cylindrical part, the rear cover part is provided with a circular ring part in the direction of the sprue, and the first runner and the third runner are symmetrically distributed on the two sides of the circular ring part.

5. A precision cast construction of an impeller as defined in claim 3, wherein: The gate part is connected to the end surface of the blade part through the side gate.

6. A precision cast construction of an impeller as defined in claim 2, wherein: The sprue is provided with a slag accumulation part at the bottom of the third runner.

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