Forced cooling device in sand casting of large steel casting

Abstract

The utility model discloses a forced cooling device in large steel casting sand mold casting, and relates to the technical field of sand mold forging, the forced cooling device comprises a casting mold assembly and a cooling assembly; the cooling assembly comprises an air blower, a liquid nitrogen tank and cooling pipes, the output end of the air blower is connected with the liquid nitrogen tank, the outlet end of the liquid nitrogen tank is connected with the cooling pipes, the cooling pipes are spiral, a plurality of air conveying holes are formed in the cooling pipes, a plurality of heat absorption columns are arranged on the outer walls of the cooling pipes, and a plurality of heat dissipation columns are arranged on the inner walls of the cooling pipes; the air blower is arranged to blow liquid nitrogen into the cooling pipe, the steel casting in the casting mold assembly releases heat to the sand mold, the cooling pipe absorbs heat of the sand mold, and therefore cooling of the sand mold and the steel casting is achieved, the spiral cooling pipe is arranged, the contact area of the cooling pipe and the sand mold is increased, the heat conduction capacity is enhanced, and the cooling speed of the steel casting is increased; and the quality problems of sand burning, shrinkage and the like caused by non-uniform temperature in the steel casting are reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of sand forging, in particular to a forced cooling device in sand forging of large steel castings. BACKGROUND

[0002] In the sand forging process of large steel castings, due to the characteristics of large volume and thick wall, the cooling process is often slow, which can easily lead to uneven internal temperature distribution and further cause problems such as sand sticking and shrinkage defects. In order to solve these problems, forced cooling devices are widely used in the sand forging process of large steel castings. The basic principle of the forced cooling device is that the forced cooling device sets up a cooling medium delivery system inside or around the casting, uses the flow of the cooling medium to take away the heat of the casting, thereby accelerating the cooling process. Common cooling media include compressed air, water or other cooling liquids.

[0003] In existing casting technology, when a sand mold is used to cast a workpiece, the molded piece cannot be removed from the sand core until the molten metal poured into the mold cavity has completely cooled and formed.

[0004] However, the sand core material itself has strong heat preservation performance, making it difficult for heat to be quickly dissipated, which slows down the cooling process of the workpiece and significantly extends the molding time of the workpiece, significantly reducing the casting efficiency. This natural cooling method not only takes a long time, but also easily causes uneven temperature inside the workpiece, thereby causing quality problems such as sand sticking and shrinkage. CONTENT OF THE INVENTION

[0005] The purpose of the present application is to provide a forced cooling device in sand forging of large steel castings to improve the problem that the natural cooling method takes a long time and easily causes uneven temperature inside the workpiece, thereby causing quality problems such as sand sticking and shrinkage.

[0006] The application provides a forced cooling device in sand forging of large steel castings, which adopts the following technical scheme:

[0007] A forced cooling device in sand forging of large steel castings, comprising a mold assembly and a cooling assembly; the cooling assembly comprises a blower, a liquid nitrogen tank and a cooling pipe, the output end of the blower is connected with the liquid nitrogen tank, the outlet end of the liquid nitrogen tank is connected with the cooling pipe, the cooling pipe is provided with a plurality of groups, and the cooling pipe is in a spiral shape.

[0008] By adopting the technical scheme, the liquid nitrogen is blown into the cooling pipe by the air blower, the cast steel part in the mold assembly releases heat to the sand mold, and the cooling pipe absorbs the heat of the sand mold, so that the cooling of the sand mold and the cast steel part is realized.

[0009] Optionally, the mold assembly comprises an upper mold and a lower mold, the upper mold and the lower mold are attached, and a cavity is arranged between the upper mold and the lower mold, and the cooling pipe is arranged outside the two sides of the cavity.

[0010] By adopting the technical scheme, the cooling pipe is arranged on both sides of the cavity, the temperature of the cast steel part is relatively uniform, and the shrinkage of the cast steel part caused by uneven temperature is avoided, thereby affecting the product quality.

[0011] Optionally, one end of the cooling pipe is provided with a communication device, the communication device communicates with a group of cooling pipes, one side of the communication device is provided with a gas pipe, and the communication device is communicated with the liquid nitrogen tank through the gas pipe.

[0012] By adopting the technical scheme, the liquid nitrogen delivery speed of the cooling pipe on both sides of the cast steel part is uniformed by arranging the communication device, the temperature on both sides of the cast steel part is averaged, and the product quality of the cast steel part is affected by avoiding uneven temperature.

[0013] Optionally, the gas pipe is provided with a gas valve.

[0014] By adopting the technical scheme, the opening and closing of the cooling assembly and the control of the flow rate of the gas flow in the cooling pipe are facilitated by arranging the gas valve, so that the controllability of the device is improved, and the cooling speed is adjusted in cooperation with the cast steel part.

[0015] Optionally, the end of the cooling pipe away from the communication device is connected with a gas outlet pipe, and the gas outlet pipe extends to the outside of the mold assembly.

[0016] By adopting the technical scheme, the heated gas is discharged through the gas outlet pipe, and the heat in the mold assembly is taken away.

[0017] Optionally, a plurality of gas inlet holes are arranged on the cooling pipe.

[0018] By adopting the technical scheme, the low-temperature gas in the cooling pipe can enter the sand mold through the gas inlet hole, the temperature in the sand mold is lowered, and the sand mold is wrapped by the low-temperature gas through free diffusion, so that the overall cooling of the sand mold is uniform.

[0019] Optionally, a plurality of heat absorption columns are arranged on the outer wall of the cooling pipe, and a plurality of heat dissipation columns are arranged on the inner wall of the cooling pipe.

[0020] By adopting the technical scheme, the heat absorption column is inserted into the sand mold to absorb heat in the sand mold, the temperature of the cast steel part is reduced through heat transfer, the heat absorption column conducts heat to the heat dissipation column, the low-temperature gas in the cooling pipe absorbs the heat of the heat dissipation column, the performance of the cooling pipe for absorbing high temperature is further improved, and the cooling speed of the cast steel part is accelerated.

[0021] Optionally, the upper mold top surface is provided with a pouring opening, and a plurality of auxiliary air holes are arranged around the pouring opening.

[0022] By adopting the technical scheme, the cast steel part is poured by inputting raw materials through the pouring hole, the gas input into the sand mold through the auxiliary air hole is discharged from the mold assembly after absorbing heat in the sand mold.

[0023] Optionally, the upper mold and the lower mold are connected and provided with a fixing member.

[0024] By adopting the technical scheme, the upper mold and the lower mold are stably fixed by the fixing member, so that the forming quality of the cast steel part is avoided.

[0025] In summary, the present application has at least one of the following beneficial technical effects of the forced cooling device in large-scale cast steel sand mold casting:

[0026] 1. The liquid nitrogen is blown into the cooling pipe by the air blower, the cast steel part in the mold assembly releases heat to the sand mold, the cooling pipe absorbs the heat of the sand mold, thereby realizing the cooling of the sand mold and the cast steel part, the spiral cooling pipe is arranged, the contact area between the cooling pipe and the sand mold is increased, the heat conduction capacity is enhanced, the cooling speed of the cast steel part is accelerated, and the phenomenon of temperature unevenness in the cast steel part is reduced, thereby causing quality problems such as sand sticking and shrinkage;

[0027] 2. The communication device is arranged to uniformly control the liquid nitrogen delivery speed of the cooling pipes on both sides of the cast steel part, average the temperature on both sides of the cast steel part, and avoid the influence of temperature unevenness on the product quality of the cast steel part;

[0028] 3. The heat absorption column is inserted into the sand mold to absorb heat in the sand mold, the temperature of the cast steel part is reduced through heat transfer, the heat absorption column conducts heat to the heat dissipation column, the low-temperature gas in the cooling pipe absorbs the heat of the heat dissipation column, the performance of the cooling pipe for absorbing high temperature is further improved, and the cooling speed of the cast steel part is accelerated. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the forced cooling device in large-scale cast steel sand mold casting.

[0030] Figure 2 It is a schematic diagram for embodying the structure of the mold assembly in the embodiment.

[0031] Figure 3is a schematic diagram for embodying the cooling pipe structure in the embodiment.

[0032] Figure 4 is a schematic diagram for embodying the heat absorbing column structure in the embodiment.

[0033] In the figure, 1, mold assembly; 11, upper mold; 12, lower mold; 13, cavity; 2, cooling assembly; 21, air blower; 22, liquid nitrogen tank; 23, cooling pipe; 231, heat absorbing column; 232, heat dissipating column; 233, gas delivery hole; 3, communication device; 4, gas delivery pipe; 5, gas valve; 6, gas outlet pipe; 7, pouring opening; 8, auxiliary gas hole; 9, fixing member. DETAILED DESCRIPTION

[0034] The following will be described in detail with reference to the accompanying drawings. Figure 1 - the accompanying drawings Figure 4 , the present application will be further described in detail.

[0035] A forced cooling device in sand casting of large steel castings, referring to Figure 1 , Figure 3 , Figure 4 , comprising a mold assembly 1 and a cooling assembly 2; the cooling assembly 2 comprises an air blower 21, a liquid nitrogen tank 22 and a cooling pipe 23, the output end of the air blower 21 is provided with a pipeline connected with the liquid nitrogen tank 22, a communication device 3 is arranged between the outlet end of the liquid nitrogen tank 22 and the cooling pipe 23, the communication device 3 is a closed shell with good air tightness, the communication device 3 is provided with a gas delivery pipe 4 on one side, the gas delivery pipe 4 is communicated with the outlet end of the liquid nitrogen tank 22, the gas delivery pipe 4 is provided with a gas valve 5 for controlling the opening, closing and flow rate of the gas delivery pipe 4, the cooling pipe 23 is provided with several groups, specifically two groups, one group has two cooling pipes 23, one group is arranged in the upper mold 11 and the lower mold 12 respectively, the communication device 3 communicates one group of cooling pipes 23 and the gas delivery pipe 4, the communication device 3 and the cooling pipe 23 are detachably connected by insertion, which is convenient for opening the mold of the steel casting;

[0036] The cooling pipe 23 is in a spiral shape, the cooling pipe 23 is fixedly connected with a gas outlet pipe 6 at the end away from the communication device 3, the gas outlet pipe 6 extends to the outside of the mold assembly 1, which is convenient for discharging the gas after absorbing heat, a plurality of gas delivery holes 233 are formed in the cooling pipe 23, the gas delivery holes 233 are arranged through the inner wall of the cooling pipe 23, a plurality of heat absorbing columns 231 are arranged on the outer wall of the cooling pipe 23, a plurality of heat dissipating columns 232 are arranged on the inner wall of the cooling pipe 23, the heat dissipating columns 232 and the heat absorbing columns 231 are arranged in pairs, the cooling pipe 23 is made of a metal material with good thermal conductivity, and the heat absorbing columns 231 and the heat dissipating columns 232 are made of a material with better thermal conductivity;

[0037] Reference Figure 1 , Figure 2The casting mold assembly 1 comprises an upper mold 11 and a lower mold 12, the upper mold 11 and the lower mold 12 are attached, a fixing part 9 is arranged at the connecting part of the upper mold 11 and the lower mold 12, the upper mold 11 and the lower mold 12 are tightly connected through the fixing part 9, the fixing part 9 is a fixing plate arranged on both sides of the upper mold 11 and the lower mold 12, the upper mold 11 and the lower mold 12 are fixed and connected through the threaded holes arranged on the fixing plate, the upper mold 11 is provided with a pouring port 7 on the top surface, the upper mold 11 and the lower mold 12 are internally provided with a cavity 13 for pouring and molding the cast steel part, cooling pipes 23 are arranged on both sides of the cavity 13, a plurality of auxiliary air holes 8 are arranged around the pouring port 7, and the auxiliary air holes 8 cooperate with the air conveying holes 233 to flow and conduct heat in the sand mold.

[0038] The implementation principle of the embodiment of the application is:

[0039] In actual work, after pouring is completed, the micro-open valve 5 is opened, the air blower 21 inputs air into the liquid nitrogen tank 22 to become low-temperature gas, the low-temperature gas is synchronously input into the upper mold 11 and the lower mold 12 through the communicating vessel 3, and the cavity 13 is cooled through the spiral cooling pipes 23 on both sides of the cavity 13, the heat absorbing column 231 and the heat radiating column 232 help the cooling pipes 23 to exchange heat, the air conveying holes 233 input the low-temperature gas into the sand mold, the low-temperature gas is discharged through the auxiliary air holes 8, the gas in the cooling pipes 23 is discharged through the air outlet pipe 6, the cast steel part is rapidly cooled, and the quality problems such as sand sticking and shrinkage of the cast steel part are reduced.

[0040] The embodiments of the specific embodiment are the preferred embodiments of the application, and are not limited to the protection scope of the application, wherein the same parts are indicated by the same reference numerals. Therefore, equivalent changes made according to the structure, shape and principle of the application should be covered in the protection scope of the application.

Claims

1. A forced cooling device in sand casting of large steel castings, characterized in that: Including casting module assembly (1), cooling assembly (2), the cooling assembly (2) includes air blower (21), liquid nitrogen tank (22) and cooling pipe (23), the air blower (21) output end is connected with liquid nitrogen tank (22), the liquid nitrogen tank (22) outlet end is connected with cooling pipe (23), the cooling pipe (23) is provided with several groups, the cooling pipe (23) is spiral.

2. A forced cooling device in sand casting of large steel castings according to claim 1, characterized in that: The casting module assembly (1) includes upper die (11) and lower die (12), the upper die (11) lower die (12) is attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die (12) are attached, and the upper die (11) and the lower die ( 3. A forced cooling device in sand casting of large steel castings according to claim 1, characterized in that: ​ 4. A forced cooling device in sand casting of large steel castings according to claim 3, characterized in that: ​ 5. A forced cooling device in sand casting of large steel castings according to claim 1, characterized in that: ​ 6. A forced cooling device in sand casting of large steel castings according to claim 1, characterized in that: ​ 7. A forced cooling device in sand casting of large steel castings according to claim 1, characterized in that: ​ 8. A forced cooling device in sand casting of large steel castings according to claim 2, characterized in that: ​ 9. A forced cooling device in sand casting of large steel castings according to claim 2, characterized in that: ​

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