Method for preventing sinking of a core for casting a whole cast mixed-flow runner

Abstract

The application relates to a method for preventing sinking of a cast mixed-flow integrally-cast runner group core, which comprises the following steps: 1) preparing a runner sand core; 2) preparing a support frame, the support frame comprising a base and a stand column, the bottom of the stand column being fixedly connected with the base, the top of the stand column being connected with a plurality of hook rings along the outer periphery, and the hook rings being hung with a traction device; 3) combining a plurality of single sand cores, the bottom of each single sand core being supported by a vertical plate; the upper circumferential surface of the combined runner sand core being fixed by winding with a bandage; 4) placing the support frame in the central hole of the runner sand core and connecting the traction device with the runner sand core; 5) tightening the traction device and then taking out the vertical plate supporting the runner sand core; 6) welding and fixing the runner sand core; 7) installing an outer sand mold outside the runner sand core; and 8) pouring. The support device is installed in the middle part of the runner sand core, the combined runner sand core is tightened towards the center, the sinking of the core after the sinking of the integrally-cast runner group core is prevented, and the position and size of the middle blade of the integrally-cast runner are controlled.

Description

Technical Field

[0001] This invention relates to the field of casting, and in particular to a method for preventing the sinking of a core assembly of a mixed-flow integral casting impeller. Background Technology

[0002] The main cast steel components of hydroelectric power generation equipment include the runner and hub. During operation, the runner withstands enormous alternating loads and is subjected to the impact of high-pressure water and silt. The blades are prone to corrosion, therefore, the quality requirements for the castings are very high. Mixed-flow integrally cast runners have the upper crown, blades, and lower ring cast as a single unit. The blade profile dimensional accuracy and surface roughness requirements are high, and flaw detection is quite rigorous. For large cast steel components, the sand mold size itself is relatively large, and the weight of the sand mold is considerable. The lower core is prone to sinking, leading to blade deformation. Once the blades are deformed, subsequent repair is impossible, resulting in the scrapping of the casting. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for preventing the sinking of the core of a casting mixed-flow integral casting impeller, and to control the dimensions of each part of the casting.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A method for preventing sinking of a cast mixed-flow integral casting impeller core includes the following steps:

[0006] 1) Make a rotary sand core. The rotary sand core is composed of multiple individual sand cores. Each individual sand core has a metal core frame inside. The top outer side of each individual sand core has a lifting ring that is fixedly connected to the metal core frame.

[0007] 2) Make a support frame, which includes a base and a column. The bottom of the column is fixedly connected to the base. The base is made with a diameter 5-10mm smaller than the center hole of the rotating sand core. Multiple hooks are evenly distributed around the top of the column. A traction device is hung on the hooks. Support plates are staggered on the column body.

[0008] 3) Combine multiple individual sand cores, with a vertical plate supporting the bottom of each individual sand core; the upper circumferential surface of the combined rotary sand core is fixed with straps.

[0009] 4) Place the support frame in the center hole of the rotating sand core, and connect the traction device to the lifting ring of the rotating sand core. The traction devices are opposite each other to keep the rotating sand core balanced.

[0010] 5) Operators climb the support plate, adjust the tightening traction device in pairs, and then remove the vertical plate supporting the sand core of the rotating wheel;

[0011] 6) Weld and fix the cores of adjacent individual sand cores at the bottom of the rotating sand core;

[0012] 7) The external sand mold is installed on the outside of the rotating sand core;

[0013] 8) Pouring.

[0014] The traction device includes a hand-operated hoist and a steel wire rope.

[0015] Compared with existing technologies, the beneficial effects of this invention are:

[0016] This invention installs a support device in the middle of the sand core of the rotary wheel. After the core is assembled, the sand core of the rotary wheel is tightened towards the center to prevent the core from sinking after the core is installed in the integral casting rotary wheel. This controls the position and size of the blades in the integral casting rotary wheel and ensures product quality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a cross-sectional view of the present invention.

[0019] In the diagram: Sand core A, base 1, column 2, hook 3, traction device 4, support plate 5, center hole 6, upright plate 7, lifting ring 8; binding strap 9. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] like Figures 1-2 A method for preventing sinking of a cast mixed-flow integral casting impeller core includes the following steps:

[0024] 1) Make a rotating sand core A. The rotating sand core A is composed of multiple individual sand cores. Each individual sand core has a metal core frame inside. The top outer side of each individual sand core has a lifting ring 8 that is fixedly connected to the metal core frame.

[0025] 2) Make a support frame, which includes a base 1 and a column 2. The bottom of the column 2 is fixedly connected to the base 1. The diameter of the base 1 is 5-10mm smaller than the center hole 6 of the rotating sand core. Multiple hooks 3 are evenly distributed along the outer perimeter of the top of the column 2. A traction device 4 is hung on the hooks 3. Support plates 5 are staggered on the column body of the column 2.

[0026] 3) Combine multiple individual sand cores, with a vertical plate 7 supporting the bottom of each individual sand core; the upper circumferential surface of the combined rotary sand core A is fixed by wrapping with straps 9;

[0027] 4) Place the support frame in the center hole 6 of the rotating sand core A, and connect the traction device 4 to the lifting ring 8 of the rotating sand core A. The traction devices are opposite each other to keep the rotating sand core balanced.

[0028] 5) The operators climb up the support plate 5, adjust and tighten the traction device 4 in pairs, and then take out the vertical plate 7 supporting the sand core A of the rotating wheel.

[0029] 6) Weld and fix the cores of adjacent individual sand cores at the bottom of the rotating sand core A;

[0030] 7) The outer sand mold is installed on the outside of the rotating sand core A;

[0031] 8) Pouring.

[0032] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention. Furthermore, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. In addition, various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the spirit of the present invention, and should also be considered as the content disclosed by the present invention.

[0033] To make the objectives, technical solutions, and technical effects of this invention clearer, the technical solutions in the embodiments of this invention are now described clearly and completely. However, the embodiments described below are only some embodiments of this invention, not all embodiments. All other embodiments obtained by those skilled in the art in conjunction with the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] Example

[0035] A method for preventing sinking of a cast mixed-flow integral casting impeller core includes the following steps:

[0036] 1) Make a rotating sand core A. The rotating sand core A is composed of 13 individual sand cores. Each individual sand core has a metal core frame inside. The top outer side of each individual sand core has a lifting ring 8 that is fixedly connected to the metal core frame.

[0037] 2) Make a support frame, which includes a base 1 and a column 2. The bottom of the column 2 is fixedly connected to the base 1. The diameter of the base 1 is 8mm smaller than the center hole 6 of the rotary sand core. Four hooks 3 are evenly distributed around the top of the column 2. A hand chain hoist is hung on the hooks 3. Support plates 5 are staggered on the column body of the column 2.

[0038] 3) Assemble the individual sand cores, with a vertical plate 7 supporting the bottom of each individual sand core; the upper circumferential surface of the assembled rotary sand core A is wrapped and fixed with nylon straps 9;

[0039] 4) Place the support frame in the center hole 6 of the rotary sand core, and connect the hand chain hoist and wire rope to the lifting ring 8 of the rotary sand core. The hand chain hoists are opposite each other to keep the rotary sand core balanced.

[0040] 5) Operators climb the support plate, adjust and tighten the hand chain hoist in pairs, and then remove the vertical plate 7 supporting the sand core A of the rotating wheel;

[0041] 6) Weld and fix the cores of adjacent individual sand cores at the bottom of the rotating sand core A;

[0042] 7) The outer sand mold is installed on the outside of the rotating sand core A;

[0043] 8) Pouring.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preventing sinking of a cast mixed-flow integral casting impeller core, characterized in that, Includes the following steps: 1) Make a rotary sand core. The rotary sand core is composed of multiple individual sand cores. Each individual sand core has a metal core frame inside. The top outer side of each individual sand core has a lifting ring that is fixedly connected to the metal core frame. 2) Make a support frame, which includes a base and a column. The bottom of the column is fixedly connected to the base. The base is made with a diameter 5-10mm smaller than the center hole of the rotating sand core. Multiple hooks are evenly distributed around the top of the column. A traction device is hung on the hooks. Support plates are staggered on the column body. 3) Combine multiple individual sand cores, with a vertical plate supporting the bottom of each individual sand core; the upper circumferential surface of the combined rotary sand core is fixed with straps. 4) Place the support frame in the center hole of the rotating sand core, and connect the traction device to the lifting ring of the rotating sand core. The traction devices are opposite each other to keep the rotating sand core balanced. 5) Operators climb the support plate, adjust the tightening traction device in pairs, and then remove the vertical plate supporting the sand core of the rotating wheel; 6) Weld and fix the cores of adjacent individual sand cores at the bottom of the rotating sand core; 7) The external sand mold is installed on the outside of the rotating sand core; 8) Pouring.

2. The method for preventing sinking of a casting mixed-flow integral casting impeller core according to claim 1, characterized in that, The traction device includes a hand-operated hoist and a steel wire rope.

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