CN112808941A

CN112808941A - Sand core of exhaust pipe casting and casting method thereof

Info

Publication number: CN112808941A
Application number: CN202011597365.9A
Authority: CN
Inventors: 李�诚; 纳建虹; 田鑫
Original assignee: Kocel CSR Foundry Ltd
Current assignee: Kocel CSR Foundry Ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-05-18
Anticipated expiration: 2040-12-30
Also published as: CN112808941B

Abstract

A sand core of an exhaust pipe casting belongs to the technical field of casting and is used for solving the shrinkage porosity defect of the exhaust pipe casting and comprises a bottom core, an intermediate core and a cover core, wherein the bottom core and the cover core are used for forming the external outline of the exhaust pipe casting, and the intermediate core is used for forming the inner cavity structure of the exhaust pipe casting; the bottom core, the middle core and the cover core are printed by a 3DP printing technology. The mode that the whole exhaust pipe inner cavity structure of this technical scheme was cast through improving the upper and lower type mould assembling molding of wood pattern technology among the prior art does not have chill direct production technology, also promptly the exhaust pipe inner cavity structure has been formed by the intermediate level is whole, has avoided the flash on the inner chamber to surface quality and the size precision of exhaust pipe inner cavity have been promoted through 3DP printing technique. Meanwhile, cold iron is arranged on the flange plate end faces at the two ends of the main pipeline of the exhaust pipe, so that the compactness of the pipeline wall is improved, and the exhaust pipe can be used at the use level from the civil level to the military level.

Description

Sand core of exhaust pipe casting and casting method thereof

Technical Field

The invention relates to the technical field of casting, in particular to a casting method of an exhaust pipe.

Background

The exhaust pipe is one of important parts of a medium-speed diesel engine, and is used for respectively discharging waste gas after combustion in a combustion chamber according to the working sequence of cylinders of the diesel engine to play a role in exhaust and flow guide. Because of direct contact with high-temperature waste gas, the working environment is severe, and meanwhile, in order to ensure that the gas flow discharge does not influence the power of the diesel engine, high-temperature resistant vermicular graphite cast iron is often adopted for casting. However, the assembling flange of the vermicular cast iron exhaust pipe end usually has the defects of shrinkage porosity and the like in casting, and cold iron is required to be added to eliminate the defects. However, the exhaust pipe castings are all thin-wall pipeline castings, and the end heads are interfered by core heads, so that the chill is inconvenient to place.

Disclosure of Invention

In view of the problem that the chill is inconvenient to place when the assembling flange surface is loosened by the chill in the casting process of the exhaust pipe casting, the sand core of the exhaust pipe casting needs to be provided, and the chill can be arranged on the core head of the pipeline sand core, the integral casting of the pipeline part of the exhaust pipe casting is realized, and the casting quality is improved by reasonably arranging the core splitting surface of the exhaust pipe sand core and arranging the core head on the pipeline core of the exhaust pipe sand core.

A sand core of an exhaust pipe casting comprises a bottom core, an intermediate core and a cover core, wherein the bottom core and the cover core are used for forming the external outline of the exhaust pipe casting, and the intermediate core is used for forming the inner cavity structure of the exhaust pipe casting; the bottom core, the middle core and the cover core are formed by printing through a 3DP printing technology, so that the surface quality and the size precision of the exhaust pipe casting are improved.

Further, the middle core is provided with a main pipeline sand core and a branch pipeline sand core, core heads are arranged at two ends of the main pipeline sand core, and cold iron is arranged on the core heads and used for playing a chilling role, so that the main pipeline is made of more compact materials, and the shrinkage porosity defect which possibly occurs is avoided, and therefore the exhaust pipe casting is promoted to the military grade from the civil grade.

Furthermore, because the pipe wall of the exhaust pipe casting is thin, the chilling block is set as a sand-isolating chilling block, so that the chilling effect of the chilling block becomes softer, and the defects of early solidification and the like caused by over-chilling are avoided.

The sand core of the exhaust pipe casting further comprises a first core splitting surface and a second core splitting surface, the first core splitting surface is parallel to the second core splitting surface, the first core splitting surface passes through the highest line of the main pipe sand core, and the second core splitting surface passes through the lowest line of the main pipe sand core, so that the middle core can form a complete inner cavity structure of the exhaust pipe casting.

The technical scheme of the invention has the beneficial effects that: the mode that the whole exhaust pipe inner cavity structure of this technical scheme was cast through improving the upper and lower type mould assembling molding of wood pattern technology among the prior art does not have chill direct production technology, also promptly the exhaust pipe inner cavity structure has been formed by the intermediate level is whole, has avoided the flash on the inner chamber to surface quality and the size precision of exhaust pipe inner cavity have been promoted through 3DP printing technique. Meanwhile, cold iron is arranged on the flange plate end faces at the two ends of the main pipeline of the exhaust pipe, so that the compactness of the pipeline wall is improved, and the exhaust pipe can be used at the use level from the civil level to the military level.

Drawings

FIG. 1 is a schematic view of an exhaust pipe structure;

FIG. 2 is a schematic view of the sand core structure of the exhaust pipe;

FIG. 3 is a schematic illustration of a split core explosion;

FIG. 4 is a schematic view of an intermediate core;

wherein, 1-exhaust pipe casting; 2-main pipeline sand core; 3-branch pipeline sand cores; 4-chilling; 5-cover core; 6-an intermediate core; 7-bottom core; 8-core print baffle.

Detailed Description

In order to more clearly illustrate the technical solutions of the present invention, the technical solutions of the present invention are described in detail with reference to the accompanying drawings, and it is obvious that the following descriptions are some exemplary embodiments of the present invention, and it is obvious for those skilled in the art that other solutions can be obtained according to the embodiments without creative efforts.

In order to minimize the sand-iron ratio for casting the exhaust pipe casting, the casting process is designed by horizontally casting one box and two pieces, and the technical scheme of the invention is shown in figures 1 to 4, and the specific embodiment is as follows.

As shown in fig. 1, which is a schematic structural diagram of an exhaust pipe casting, a first core splitting surface and a second core splitting surface are arranged on two parallel lines along the highest point and the lowest point of a flange of a main pipeline, the first core splitting surface and the second core splitting surface are parallel to each other, and an inner cavity structure of the exhaust pipe casting is completely arranged between the first core splitting surface and the second core splitting surface. As shown in fig. 1, in order to achieve the minimum sand-iron ratio, two exhaust pipes are arranged in one production, the two exhaust pipes are arranged in an L shape, and a branch pipe is positioned inside the L shape. The arrangement mode realizes the lowest sand-iron ratio of casting of the exhaust pipe casting.

The utility model provides a psammitolite of blast pipe foundry goods, includes lid core 5, middle core 6 and end core 7, lid core 5 with end core 7 is used for forming the outside profile of blast pipe foundry goods, middle core 6 is used for forming the inner chamber structure of blast pipe foundry goods, just lid core 5, middle core 6 and end core 7 are printed by 3DP technique and are formed to further promote the surface quality of blast pipe foundry goods psammitolite, and then guaranteed the quality and the size precision on surface of blast pipe foundry goods.

The middle core 6 is provided with two exhaust pipe sand cores which are arranged in an L shape, the branch pipe sand cores 3 are located on the inner side of the L shape, so that the other pipe opening of the main pipe sand core 2 is located on the edge of the middle core 6, the external outline of the middle core 6 is a rectangular frame, and the edge of the rectangular frame is the minimum sand-eating amount limit for casting the two exhaust pipe sand cores which are arranged in the L shape. The main pipeline sand core is characterized in that a core head is arranged on the flange plate end face of the main pipeline sand core, and a sand-isolating chilling block is placed at the position of the core head to adjust the temperature field of the molten metal in the main pipeline cavity, so that the molten metal in the main pipeline cavity can be uniformly solidified, and a main pipeline with uniform and compact texture is obtained. Because set up the core head's the reason for make the shared space grow of trunk line psammitolite, and do not change under the size of the outer profile rectangle frame of middle core 6 and the condition of minimum sand eating volume, will be located two core head overlap joints on two tops of L type on the edge of rectangle frame, and empty the overlap joint on middle core 6 rectangle frame edge on the core head corresponds the core sand on the edge of part, also make two that are located two tops of L type the core head exposes in the rectangle frame of middle core 6, also not by rectangle frame parcel, or said, the edge of the outer profile rectangle frame of middle core 6 is discontinuous, locates the disconnection at two tops of L type. The rectangular frame of the bottom core 7 is provided with a core print baffle 8, the position of the core print baffle 8 corresponds to the direction of the break of the middle core 6, and the thickness and the height of the core print baffle 8 are just matched with the frame and the core print of the middle core 6. The core print baffle 8 is provided with two cores on the bottom core 7 corresponding to the exhaust pipes of one box and two pieces.

The casting method of the exhaust pipe casting comprises the following steps:

1) drawing a three-dimensional model of the exhaust pipe casting according to the pattern of the exhaust pipe casting, arranging the three-dimensional models of the two exhaust pipe castings into an L shape, and arranging a pouring system;

2) embedding the three-dimensional model with the pouring system in a cube with the minimum sand-holding amount, and then performing shell extraction treatment to obtain a core package of the exhaust pipe casting;

3) dividing the mold core package into a cover core, a middle core and a bottom core according to the positions of the core dividing surface I and the core dividing surface II;

4) the generated slice data of the cover core, the middle core and the bottom core are issued to 3DP printing equipment, and the cover core, the middle core and the bottom core are printed out through the 3DP printing equipment;

5) cleaning and coating the cover core, the middle core and the bottom core, and then matching the cover core, the middle core and the bottom core, namely recombining the cover core, the middle core and the bottom core into an integral cube;

6) and (4) casting after the pouring gate is configured, and obtaining the exhaust pipe casting after condensation.

The above embodiment is only a description of a typical application of the technical solution of the present invention, and may be reasonably expanded without creative efforts.

Claims

1. The sand core of the exhaust pipe casting is characterized by comprising a bottom core, an intermediate core and a cover core, wherein the bottom core and the cover core are used for forming the external outline of the exhaust pipe casting, and the intermediate core is used for forming the inner cavity structure of the exhaust pipe casting; the bottom core, the middle core and the cover core are printed by a 3DP printing technology.

2. The sand core for an exhaust pipe casting as recited in claim 1, wherein said intermediate core is provided with a main pipe sand core and a branch pipe sand core, and core heads are provided at both ends of said main pipe sand core, and chill is provided on said core heads.

3. The sand core of an exhaust pipe casting as recited in claim 2, wherein said chills are sand insulated chills.

4. The exhaust pipe casting sand core of claim 3, further comprising a parting surface one and a parting surface two, wherein the parting surface one is parallel to the parting surface two, the parting surface one passes through the highest line of the main pipe sand core, and the parting surface two passes through the lowest line of the main pipe sand core.

5. The sand core for an exhaust pipe casting as recited in claim 2, wherein the two core taps of said main pipe sand core located at the two top ends of the L-shape are overlapped with the edges of the rectangular frame of said intermediate core, and the edges of the rectangular frame at said overlapped portions are broken.

6. The sand core for an exhaust pipe casting as recited in claim 5, wherein a core print baffle is further provided on said bottom core.

7. The sand core of an exhaust pipe casting as recited in claim 6, wherein said core print dam cooperates with the break in the intermediate core to complete the intermediate core.

8. The casting method of the exhaust pipe casting is characterized by comprising the following steps of:

drawing a three-dimensional model of the exhaust pipe casting according to the pattern of the exhaust pipe casting, arranging the three-dimensional models of the two exhaust pipe castings into an L shape, and arranging a pouring system;

embedding the three-dimensional model with the pouring system in a cube with the minimum sand-holding amount, and then performing shell extraction treatment to obtain a core package of the exhaust pipe casting;

dividing the mold core package into a cover core, a middle core and a bottom core according to the positions of the core dividing surface I and the core dividing surface II;

and issuing the generated slice data of the cover core, the middle core and the bottom core to 3DP printing equipment, and printing the cover core, the middle core and the bottom core through the 3DP printing equipment.