CN211248202U

CN211248202U - Sand box device of large-scale annular wind power casting

Info

Publication number: CN211248202U
Application number: CN201922422042.5U
Authority: CN
Inventors: 郑仲渊; 洪广琪
Original assignee: Ningbo Lulin Machinery Casting Co ltd
Current assignee: Ningbo Lulin Machinery Casting Co ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-08-14
Anticipated expiration: 2029-12-27

Abstract

A sand box device for a large annular-hole wind power casting comprises a sand box and molding sand; the molding sand is filled in a sand box, forms a cavity and is internally provided with a mold core, and is characterized in that the mold core comprises a core bar and a core sand layer coated outside the core bar; the core rod is formed by a metal pipe with a plurality of through holes uniformly distributed on the side wall, and the top of the metal pipe is connected with an exhaust pipeline. The metal tube helps to conduct and dissipate heat, and at the same time, the hollow metal tube can also occupy a larger volume to reduce the amount of molding sand. The requirements on the material of the metal pipe are not high, and a galvanized steel pipe can be generally adopted. For some castings with high process requirements, alloy steel pipes containing copper can be adopted to increase the heat conducting property and ensure the structural strength of the castings.

Description

Sand box device of large-scale annular wind power casting

Technical Field

The utility model belongs to the technical field of the casting, specifically a sand box device of large-scale annular wind-powered electricity generation foundry goods.

Background

Wind power product castings are very large in size and weight, and accordingly, large-volume sand boxes are needed for casting. For a ring hole type casting in a wind power product, a core is required to assist in forming the ring hole. Because of the large size of such annular rings, the sand usage of the cores is also large. The large amount of the molding sand brings about a problem of low cooling speed of the casting in addition to a problem of cost. Slower cooling rates have an adverse effect on the quality of the casting, such as local grain size.

Disclosure of Invention

In order to solve the technical problem, the utility model provides a sand box device for large-scale annular wind power castings, which comprises a sand box and molding sand; the moulding sand is contained in a sand box and constitutes a moulding cavity in which a core is housed, which is generally supported by a core holder inside the moulding cavity. The mold core comprises a core rod and a core sand layer coated outside the core rod; the core rod is formed by a metal pipe with a plurality of through holes uniformly distributed on the side wall, and the top of the metal pipe is connected with an exhaust pipeline.

Further, the top end of the exhaust pipeline extends upwards out of the top surface of the sand box; the outer diameter of the exhaust pipe is smaller than that of the metal pipe.

Generally, a pipe communicating with the exhaust pipe of the core rod may be previously formed in the molding sand of the molding box by a mold. However, this brings difficulty to the design and manufacture of the mold, and is not as reasonable as the scheme.

Furthermore, a plurality of metal pipes forming the core are provided; the metal tubes are parallel to each other and symmetrical about the axis of the core, and the sand is filled between the metal tubes.

Alternatively, the metal tube constituting the core rod has one end, and the axis of the metal tube coincides with the axis of the core.

Furthermore, a plurality of metal pipes are vertically arranged in the molding sand between the cavity and the inner wall of the sand box to form an auxiliary heat dissipation layer, and the molding sand is filled between the metal pipes.

And a cavity side wall layer is arranged between the cavity and the auxiliary heat dissipation layer and is made of molding sand.

The metal tube helps to conduct and dissipate heat, and at the same time, the hollow metal tube can also occupy a larger volume to reduce the amount of molding sand. The requirements on the material of the metal pipe are not high, and a galvanized steel pipe can be generally adopted. For some castings with high process requirements, alloy steel pipes containing copper can be adopted to increase the heat conducting property and ensure the structural strength of the castings.

Drawings

FIG. 1 is a schematic cross-sectional view of the flask apparatus;

FIG. 2 is a schematic view of a metal tube;

in the figure: the sand box comprises a sand box 1, a cavity 2, a cavity side wall layer 3, an auxiliary heat dissipation layer 4, a molding sand layer 5, a metal pipe 6, a mold core 7, a core rod 8, a core sand layer 9, an exhaust pipeline 10, a vent pipe 11, a through hole 12 and a connecting hole 13.

Detailed Description

The present disclosure is further described with reference to the following drawings and detailed description:

referring to fig. 1, the sand box device for the large annular wind power casting comprises a sand box and molding sand; the moulding sand is contained in a flask and constitutes a moulding cavity in which a core is housed (supported by a core holder inside the moulding cavity). The mold core comprises a core rod and a core sand layer coated outside the core rod; the core bone is formed by steel pipes with a plurality of through holes uniformly distributed on the side wall, and the tops of the steel pipes are connected with an exhaust pipeline.

In the embodiment, there are a plurality of steel pipes constituting the core; a plurality of steel pipes are parallel to each other and are symmetrical around the axis of the mold core, and molding sand is filled between the steel pipes. Furthermore, a vent pipe is connected between the steel pipes, the top of only one steel pipe is connected with an exhaust pipeline, and all the steel pipes exhaust air through the exhaust pipeline.

In another form, the core is formed from a single steel tube having an axis coincident with the axis of the core.

In this example, a plurality of steel pipes are vertically arranged in the molding sand between the cavity and the inner wall of the sand box to form an auxiliary heat dissipation layer, and the molding sand is filled between the steel pipes.

And a molding sand layer is also arranged on the bottom surface of the sand box and is made of molding sand. The thickness of the sand layer may be about 60 mm.

As shown in FIG. 2, the steel pipe has a plurality of regular through

holes

12 and 1 pair of connecting holes 13 on its side wall. The connecting hole is used for connecting the vent pipe between two adjacent steel pipes. The function of the connection hole 13 is the same as that of the general through hole 12 when there is no snorkel connection.

Because the molding sand is formed by mixing silica sand, clay or bonding materials, water and the like, the molding sand has certain viscosity (the shape of the molding sand is similar to that of asphalt concrete for paving a pavement), and under the condition that the through holes are not large, the molding sand leaking into the cavity in the steel pipe is less and even does not leak into the molding sand.

In practice, it has also been found that metal tubes with open side walls have good venting properties.

The molding sand is formed by mixing silica sand, clay or bonding materials and water, and after the molding sand is heated, the bonding materials, the water and the like generate gas, if the gas cannot be fully diffused out, the gas reversely permeates into molten steel in a cavity, part of the gas is discharged out of the cavity from a riser, and the other part of the gas affects a casting. In order to exhaust the air, the molding sand of the flask is additionally provided with air holes.

The steel pipes of the sand box are provided with the through holes, and the through holes are beneficial to the gas in the molding sand to be drilled into the hollow steel pipes and can be discharged in time.

Claims

1. A sand box device for a large annular-hole wind power casting comprises a sand box and molding sand; the molding sand is filled in a sand box, forms a cavity and is internally provided with a mold core, and is characterized in that the mold core comprises a core bar and a core sand layer coated outside the core bar; the core rod is formed by a metal pipe with a plurality of through holes uniformly distributed on the side wall, and the top of the metal pipe is connected with an exhaust pipeline.

2. The sand box device for large-scale annular wind power castings according to claim 1, wherein the top end of the exhaust duct extends upward beyond the top surface of the sand box; the outer diameter of the exhaust pipe is smaller than that of the metal pipe.

3. The sand box device for large-scale annular wind power castings according to claim 1 or 2, wherein a plurality of metal pipes constituting the core are provided; the metal tubes are parallel to each other and symmetrical about the axis of the core, and the sand is filled between the metal tubes.

4. The apparatus for molding sand boxes for large-scale annular wind power castings according to claim 1 or 2, wherein there is one metal pipe constituting the core, and the axis of the metal pipe coincides with the axis of the core.

5. The sand box device for large-scale annular wind power castings according to claim 1 or 2, wherein a plurality of metal pipes are vertically arranged in the molding sand between the cavity and the inner wall of the sand box to form an auxiliary heat dissipation layer, and the molding sand is filled between the metal pipes.

6. The sand box device for large-scale annular wind power castings according to claim 5, wherein a cavity side wall layer is arranged between the cavity and the auxiliary heat dissipation layer, and the cavity side wall layer is made of molding sand.