Split type differential shell loam core improved structure

Abstract

The utility model discloses an improved structure of a split type differential shell loam core, and belongs to the technical field of differential shell loam cores. Comprising a core box, cavities, differential shell loam cores and shaft necks, the multiple cavities are formed in the core box, the differential shell loam cores are arranged in the cavities and used for forming inner cavities of differential shells in the casting process, the differential shell loam cores comprise the shaft necks, and chilling blocks are arranged on the differential shell loam cores and located at the shaft necks. The utility model solves the problem that the shrinkage porosity at the flange can be improved by increasing the modulus of the riser and the riser neck in the prior art, but the shrinkage porosity at the shaft neck cannot be solved, and the shrinkage porosity is improved by adjusting the loam core structure at the shaft neck and solidifying the shaft neck at first under the chilling effect of the chiller in the process of putting the chiller at the shaft neck.

Description

Technical Field

[0001] The utility model relates to the technical field of differential housing cores, and particularly relates to an improved structure of a split differential housing core. Background Art

[0002] During the casting production of split differential housings, an auxiliary core needs to be placed. The material grade is QT550-10, the tensile strength is ≥550 Mpa, the elongation is ≥10, and there are welding requirements for the flange surface, with the requirement that pearlite <45%. Considering the comprehensive product structure and material requirements, high silicon is needed to meet the performance, which increases the tendency of shrinkage porosity. Especially at the journal, shrinkage porosity will occur during the machining process, affecting the product performance. The prior art can improve the shrinkage porosity at the flange by increasing the modulus of the riser and the riser neck, but it cannot solve the shrinkage porosity at the journal because the journal is an isolated hot spot and cannot receive the feeding of molten iron in the later stage of solidification. Content of the Utility Model

[0003] The purpose of the utility model is to provide an improved structure of a split differential housing core. By adjusting the core structure at the journal and applying the process of placing chill blocks at the journal, under the chilling effect of the chill blocks, the journal solidifies first, thereby improving the shrinkage porosity, and solving the problem that in the prior art, increasing the modulus of the riser and the riser neck can improve the shrinkage porosity at the flange, but cannot solve the shrinkage porosity at the journal.

[0004] To achieve the above purpose, the utility model provides the following technical solution: an improved structure of a split differential housing core, including a core box, a cavity, a differential housing core, and the journal. Multiple cavities are arranged inside the core box, and a differential housing core is arranged inside the cavity, which is used to form the inner cavity of the differential housing during the casting process. The differential housing core includes the journal, and chill blocks are arranged on the differential housing core and located at the journal.

[0005] Preferably, the chill blocks adopt long chill blocks.

[0006] Preferably, the chill blocks adopt short chill blocks.

[0007] Preferably, both the long chill blocks and the short chill blocks are in the shape of a cylindrical tube with an internal opening.

[0008] Preferably, the long chill blocks include a large-diameter part and a tapered part that are coaxially and integrally arranged up and down.

[0009] Preferably, both the tapered part and the large-diameter part have a smooth surface, and the large-diameter end of the tapered part is equal to the outer diameter of the large-diameter part.

[0010] Preferably, the outer diameter of the chill blocks is 30 - 80 mm smaller than the diameter of the inner side surface of the matching core box.

[0011] Preferably, the surface of the chill blocks is coated with a coating for removing the chill blocks.

[0012] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0013] 1. An improved structure of a split differential case core in the present utility model adjusts the core structure at the journal. By applying the under-chill process at the journal, under the chilling effect of the chill, the journal solidifies first, thus improving shrinkage porosity. The chill is inversely buckled inside the core in the form of an inverted draw mold, so that the chill will not fall off. During the core-making process, the worker manually places the pre-coated chill into the core cavity, and the operation is convenient.

[0014] 2. An improved structure of a split differential case core in the present utility model uses short chills. The chills are small and can be recycled, which is convenient for collection. The use of chills can reduce the consumption of core-coated sand, saving costs. Moreover, the surface of the chills is coated, and the chills and the castings can automatically fall off, reducing the cost of manually removing the chills. There is no problem in processing, which can effectively solve the shrinkage porosity problem at the journal and does not affect the product performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the core box structure of the present utility model;

[0016] Figure 2 is a schematic diagram of the long-chill differential case core structure of the present utility model;

[0017] Figure 3 is a schematic diagram of the short-chill differential case core structure of the present utility model;

[0018] Figure 4 is a schematic cross-sectional structure diagram of the short-chill differential case core of the present utility model.

[0019] In the figure: 1. Core box; 2. Cavity; 3. Differential case core; 301. Journal part; 4. Long chill; 401. Large-diameter part; 402. Tapered part; 5. Short chill. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0021] To solve the technical problem in the prior art that although the shrinkage porosity at the flange can be improved by increasing the modulus of the riser and the riser neck, the shrinkage porosity at the journal cannot be solved, please refer to Figures 1-4 , the following technical solutions are provided:

[0022] Embodiment 1

[0023] In this embodiment, an improved structure of a split differential case core includes a core box 1, a cavity 2, a differential case core 3, and a journal part 301. A plurality of cavities 2 are provided inside the core box 1, and a differential case core 3 is provided inside the cavity 2, which is used to form the inner cavity of the differential case during the casting process. The differential case core 3 includes a journal part 301, and chill blocks are provided on the differential case core 3, and the chill blocks are located at the journal part 301. By using the chill block process at the journal part 301, under the chilling effect of the chill blocks, this part solidifies first, thereby improving shrinkage porosity.

[0024] The chill block uses a long chill block 4, and the long chill block 4 is a cylindrical shape with an internal opening.

[0025] The long chill block 4 includes a large-diameter part 401 and a tapered part 402 that are coaxially and integrally arranged up and down. Both the tapered part 402 and the large-diameter part 401 have smooth surfaces, and the large-diameter end of the tapered part 402 is equal to the outer diameter of the large-diameter part 401. By using the long chill block 4, although the degree of supercooling is too large, which will cause white cast iron on the inner diameter machining surface, it has the advantages of no flash on the inner diameter and no need for grinding, and can solve the shrinkage porosity at the journal part 301.

[0026] Embodiment 2

[0027] In this embodiment, the chill block uses a short chill block 5, and the short chill blocks 5 are all cylindrical shapes with internal openings. By using the short chill block 5, although the inner diameter needs to be ground and a part of the inner diameter is formed into a flash by being carried out by the outer mold, it has the advantages of a small chill block, low cost, and no machining problems, and can effectively solve the shrinkage porosity problem at the journal part 301 without affecting the product performance.

[0028] It should be noted that through trial production, using this embodiment is more conducive to cost savings.

[0029] The outer diameter of the chill block is 50 mm smaller than the diameter of the inner side surface of the supporting core box 1.

[0030] The surface of the chill block is coated with a coating for removing the chill block, and the chill block and the casting can automatically fall off, reducing the cost of manually removing the chill block.

[0031] Working principle: During core making, the chill block is buckled inside the core in the form of an inverted draw mold, and the unilateral distance between the outer side surface of the chill block and the inner side surface of the core box 1 is 25 mm. Then, it is filled and compacted with resin sand. During the core making process, the manually applied chill block with coating is placed into the cavity 2, and it is convenient to operate. When demolding, the chill block is taken out together with the differential case core 3.

[0032] It should be noted that, in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0033] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model.

Claims

1. An improved structure of a split-type differential shell mud core, comprising a core box (1), a mold cavity (2), a differential shell mud core (3) and a journal (301), characterized in that: A plurality of cavities (2) are provided inside the core box (1), a differential shell mud core (3) is provided inside the mold cavity (2), and is used to form an inner cavity of the differential shell during the casting process, the differential shell mud core (3) includes a shaft neck (301), and a chill is provided on the differential shell mud core (3), and the chill is located at the shaft neck (301).

2. The improved split-type differential shell mud core structure according to claim 1 is characterized in that: The chiller is a long chiller (4).

3. The improved split-type differential shell mud core structure according to claim 2 is characterized in that: The chiller is a short chiller (5).

4. The improved split-type differential shell mud core structure according to claim 3 is characterized in that: The long chill (4) and the short chill (5) are both cylindrical with an internal opening.

5. The improved split-type differential shell mud core structure according to claim 2 is characterized in that: The long chill (4) comprises a large-diameter portion (401) and a tapered portion (402) coaxially arranged in an integral manner up and down.

6. The improved split-type differential shell mud core structure according to claim 5, characterized in that: The surfaces of the tapered portion (402) and the large-diameter portion (401) are both smooth, and the large-diameter end of the tapered portion (402) is equal to the outer diameter of the large-diameter portion (401).

7. The improved split-type differential shell mud core structure according to claim 1 is characterized in that: The outer diameter of the cold iron is 30 to 80 mm smaller than the diameter of the inner side surface of the matching core box (1).

8. The improved split-type differential shell mud core structure according to claim 1 is characterized in that: The surface of the chill is coated with a coating for removing the chill.

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