Casting mold structure for casting automobile differential shell
By improving the mold structure and sand core design in the casting of automotive differential housings, eliminating independent hot spots, and achieving feeding compensation at the shaft head and spherical shaft hole positions, the problems of complex processes and high costs were solved, resulting in the production of differential housings without internal defects, reducing production costs and increasing yield.
Patent Information
- Application Number
- CN202423243937.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-12-27
AI Technical Summary
The existing automotive differential housing casting process has the problems of complex procedures and high costs, especially the difficulty in avoiding the generation of internal defects during the feeding process.
An improved mold structure is adopted, including setting a riser at the maximum hot spot and extending its side 5mm into the casting, and separating it from the casting with a sand core. Combined with a specific sand core design, independent hot spots are eliminated, enabling feeding at the shaft head and spherical shaft hole positions, and avoiding the use of chills for rapid cooling.
The reduction of the cold ironing process increased the yield rate, lowered production costs, and produced automotive differential housing castings free of internal defects, thus improving economic efficiency.
Smart Images
Figure CN223642727U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the field of foundry technology, and concretely relates to a casting structure for casting automobile differential housing. BACKGROUND
[0002] At present, the working mode in the field of casting is generally that a casting mold (a casting mold) is manufactured and designed according to the products required by customers, then the mold is used to pour liquid metal to cast corresponding products. During the solidification process of the castings, the most important thing is to compensate through risers to ensure the appearance and internal defects of the castings. The risers with different functions are different in form, size and opening position, therefore, the design of the risers should consider the properties of the cast alloy and the characteristics of the castings. For the alloy with large volume shrinkage during solidification and the alloy that tends to form concentrated shrinkage holes, the main role of the riser is to compensate for the liquid shrinkage of the metal liquid in the mold cavity and the shrinkage during the solidification process of the casting to obtain a dense casting without shrinkage holes. When the castings cool in the mold, the thinnest part solidifies first, and its shrinkage can be compensated by the nearby thicker part; when the thicker part solidifies, it can be compensated by the thickest part; when the thickest part, i.e. the hot spot, solidifies, if it cannot be compensated externally, a large shrinkage hole will be formed at the place. In this case, the role of the riser is to compensate for the hot spot part of the casting, so it should be placed above or on the side of the thickest part of the casting, and its solidification should be later than that of the thickest part of the casting. The automobile differential housing has complex structure, many independent hot spots and high internal defect requirements, and usually needs cold iron auxiliary cooling or uses multiple risers for compensation to reduce internal defects; however, this method will lead to complex process and high production cost. CONTENT OF THE UTILITY MODEL
[0003] The utility model solves the technical problems that a casting structure for casting automobile differential housing is provided, the problems of complex process and high cost of the existing process are solved, and the compensation of specific positions is realized through the modification of the riser structure to avoid the generation of internal defects.
[0004] According to the technical scheme of the utility model, the utility model provides a casting structure for casting automobile differential housing, the differential housing casting includes a shaft head at the top end, a spherical shaft hole side wall at the side and a lock pin hole region between the shaft head and the spherical shaft hole side wall, one riser is adjacently arranged on each side of the differential housing casting, the riser is connected with the spherical shaft hole side wall of the differential housing casting through a riser neck at the side; a riser extension part is further formed above the riser neck, the riser extension part is arranged towards the differential housing casting, and the position of one end of the riser extension part close to the differential housing casting corresponds to the lock pin hole region and the lower part of the shaft head; there is a gap between the riser extension part and the differential housing casting.
[0005] Further, the shape of the riser extension near one end of the differential housing casting matches the shape of the outer side surface of the differential housing casting.
[0006] Further, a first sand core is further included, which matches the outer side of the shaft head and the lock pin hole area of the differential housing casting, and separates the riser extension from the differential housing casting to form a gap between the riser extension and the differential housing casting after pouring.
[0007] Further, a second sand core is further included, which is located on the outer side surface of the spherical shaft hole side wall of the differential housing casting and in the inner cavity of the differential housing casting.
[0008] Further, a third sand core is further included, which is located below the second sand core and corresponds to the cavity structure below the spherical shaft hole side wall of the differential housing casting.
[0009] Further, the width of the gap between the riser extension and the differential housing casting is 5mm.
[0010] Further, a pouring system is further included, which includes a sprue cup, and the axis of the sprue cup is vertically arranged, and the axis of the differential housing casting is vertically arranged.
[0011] Further, the lower end of the main runner is connected with a plurality of transverse branch runners, and the branch runners are connected with the riser and / or the differential housing casting.
[0012] Further, the branch runner is only connected with the riser.
[0013] Further, the differential housing casting is a plurality of rings distributed around the outside of the main runner, and there is a riser between two adjacent differential housing castings, and each riser has two riser necks and two riser extensions.
[0014] Compared with the prior art, the beneficial technical effects of the present application are as follows:
[0015] The riser is arranged at the maximum thermal node, the riser side extends to a position, for example, 5mm away from the casting, the locking pin hole part is wrapped, the riser is separated from the casting by using the sand core, the original riser neck is not changed, the shaft head position thermal node is connected with the riser neck position thermal node, the independent thermal node is eliminated, the shaft head part can be compensated, and the internal defects are avoided; the original automobile differential shell has a plurality of independent thermal nodes, the spherical shaft hole position is compensated by the riser, and the shaft head position thermal node is difficult to compensate, and cold iron is often used for cooling to reduce the internal defects; the scheme utilizes the changed riser structure and the sand core, and the spherical shaft hole position and the shaft head position are compensated at the same time, cold iron is not needed for cooling, the automobile differential shell casting produced has no internal defects, the cold iron process is reduced, the yield is improved, the production cost is reduced, and the economic benefit is improved. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 is a front view structural schematic diagram of a differential shell casting and a riser provided by the utility model.
[0017] Figure 2 is Figure 1 a three-dimensional structural schematic diagram of a riser part in the embodiment shown.
[0018] Figure 3 is Figure 1 a three-dimensional structural schematic diagram in a state of having a sand core in the embodiment shown.
[0019] Figure 4 is a three-dimensional structural schematic diagram of an integral casting formed by a casting structure provided by the utility model.
[0020] Figure 5 is a result diagram obtained by analyzing and simulating an original process structure by using a mold flow analysis software.
[0021] Figure 6 is a result diagram obtained by analyzing and simulating a structure of the utility model by using a mold flow analysis software.
[0022] EXPLANATION OF REFERENCE NUMERALS IN DRAWINGS:
[0023] 1, differential shell casting; 11, shaft head; 12, locking pin hole region; 13, spherical shaft hole side wall; 2, riser; 21, riser neck; 22, riser extension; 3, gap; 41, first sand core; 42, second sand core; 43, third sand core; 51, sprue cup; 52, main runner; 53, sub-runner. DETAILED DESCRIPTION
[0024] This utility model provides a casting mold structure for casting automotive differential housings, which solves the problems of complex processes or high costs in existing processes, and achieves feeding at specific locations by modifying the riser structure, thus avoiding the generation of internal defects.
[0025] Please see Figure 1 , Figure 2 This utility model discloses a casting mold structure for casting automotive differential housings, used to produce differential housing castings 1. The differential housing is an existing structure; a typical differential housing casting 1 includes a shaft head 11 at the top, a spherical shaft hole sidewall 13 on the side, and a locking pin hole area 12 between the shaft head 11 and the spherical shaft hole sidewall 13. The shaft head 11 refers to the structure at the top of the differential housing; the inner wall of the differential housing cavity is generally spherical or near-spherical, and on the side (… Figure 1 The front and rear sides of the spherical shaft hole 13 have through holes, and the spherical shaft hole sidewall 13 refers to the sidewall of the spherical cavity next to the through hole. Figure 1 (The center is located on the left and right sides); the locking pin hole area 12 refers to the part of the differential housing that is diagonally above the side wall of the cavity, corresponding to the locking pin hole and its surrounding area.
[0026] A single casting structure can be configured to simultaneously form one or more differential housing castings 1. Each differential housing casting 1 has a riser 2 adjacent to each other on both sides. The riser 2 is connected to the spherical shaft hole sidewall 13 of the differential housing casting 1 via a riser neck 21. Above the riser neck 21, a riser extension 22 is formed on the riser 2. The riser extension 22 extends towards the differential housing casting 1, and the end of the riser extension 22 closest to the differential housing casting 1 corresponds to the locking pin hole area 12 and the lower part of the shaft end 11. There is a gap 3 between the riser extension 22 and the differential housing casting 1. In other words, the end of the riser extension 22 extends close to the differential housing casting 1, but does not contact the differential housing casting 1. The riser 2 and the differential housing casting 1 are connected only through the riser neck 21. More specifically, for example, the width of the gap 3 between the riser extension 22 and the differential housing casting 1 is 5 mm.
[0027] More specifically, the shape of the end of the riser extension 22 near the differential housing casting 1 matches the shape of the outer surface of the differential housing casting 1, such as... Figure 1 , 2 As shown, the upper part of the end of the riser extension 22 has a nearly vertical arc surface (or inclined surface or other curved surface) corresponding to the shaft head 11, and the lower part of the end of the riser extension 22 has an inclined arc surface (or spherical surface, inclined surface or other curved surface) corresponding to the locking pin hole area 12. The riser neck 21 and the main body of the riser 2 can be selected as existing conventional structures or other feasible structures. The riser neck 21 is located on the lower side of the riser 2, and the riser extension 22 is separated from the riser neck 21.
[0028] Further, referring to Figure 3 , the riser and the casting structure are formed by means of the sand core structure. The sand core includes a first sand core 41 which is matchedly covered on the outer side of the shaft head 11 and the lock pin hole area 12 of the differential housing casting 1, and the first sand core 41 separates the riser extension 22 from the differential housing casting 1 to form the gap 3 between the riser extension 22 and the differential housing casting 1 after pouring, and the inner side of the first sand core 41 is also used to form the outer side of the upper part of the differential housing casting 1.
[0029] Further, the second sand core 42 (in Figure 3 , filled with diagonal patterns to more clearly show its structure) is matchedly located on the outer side of the spherical shaft hole side wall 13 of the differential housing casting 1 and in the inner cavity of the differential housing casting 1. The second sand core 42 is used to form the inner side structure of the differential housing casting 1, and the through holes of the upper end and the side; optionally, the second sand core 42 also has a riser pit (crater) for forming the bottom (at least part of) of the riser 2 and the bottom of the riser neck 21, and the rest of the riser 2 is formed by the upper and lower mold parts of the mold.
[0030] For the differential housing structure in the embodiment, the third sand core 43 is also included, which is located below the second sand core 42, and the third sand core 43 corresponds to the cavity structure (or other structures which need to be formed by sand cores) below the spherical shaft hole side wall 13 of the differential housing casting 1.
[0031] More specifically, referring to Figure 4 , the pouring system is also included, which includes a sprue cup 51, the axis of which is vertically arranged, and the axis of the differential housing casting 1 is also vertically arranged, and the riser 2 is also vertically arranged. The vertically arranged main runner 52 is connected below the sprue cup 51, and the lower end of the main runner 52 is connected with multiple transversely arranged sub-runners 53, which are connected with the riser 2 and / or the differential housing casting 1. In the embodiment, since the differential housing casting 1 is surrounded by the sand core, the sub-runner 53 is only connected with the riser 2.
[0032] Further, in the embodiment, the differential housing casting 1 is multiple which is distributed in a ring around the outside of the main runner 52, and there is one riser 2 (in other words, sharing one riser) between two adjacent differential housing castings 1, and each riser 2 has two riser necks 21 and two riser extensions 22. It is conceivable that, as Figure 4In the shown embodiment, the angle between the two riser extensions 22 on each side of the differential housing casting 1 is for example 180°, and the angle between the two riser extensions 22 on each riser 2 is less than 180°, forming a uniform regular polygonal structure; in other possible embodiments, for example in a mold in which only several differential housing castings 1 are arranged side by side in the vertical plane, the angle between the two riser extensions 22 on each riser 2 is 180°.
[0033] Please refer to Figure 5 , Figure 6 , the thermal station chart obtained by analyzing and simulating through the mold flow analysis software; it can be seen that, in the prior art structure of Figure 5 , there is an independent thermal station in the upper part of the differential housing casting (dark part) which is not eliminated, while in the structure of the present application in Figure 6 , there is no thermal station in the differential housing casting.
[0034] In summary, in the mold structure for casting the automobile differential housing of the present application, the riser is arranged at the maximum thermal station, the side of the riser extends to a distance of for example 5 mm from the casting, the locking pin hole part is wrapped, and the riser is separated from the casting by using a sand core, so that the original riser neck is not changed, the thermal station at the shaft head position is connected with the thermal station at the riser neck position, the independent thermal station is eliminated, the shaft head part is supplemented, internal defects are avoided, the original automobile differential housing has multiple independent thermal stations, the shaft hole position is supplemented by the riser, while the thermal station at the shaft head position is difficult to supplement and is often cooled by cold iron to reduce the generation of internal defects; the present application uses the changed riser structure and sand core to supplement the shaft hole position and the shaft head position, cold iron is not needed, the automobile differential housing casting produced has no internal defects, the cold iron process is reduced, the yield is improved, the production cost is reduced, and the economic benefit is improved.
Claims
1. A mold structure for casting an automobile differential case, the differential case casting (1) including a shaft head (11) at a top end, a spherical shaft hole side wall (13) at a side surface, and a lock pin hole area (12) between the shaft head (11) and the spherical shaft hole side wall (13), characterized in that, Two sprues (2) are arranged adjacent to two sides of each differential housing casting (1), the sprues (2) are connected with the side wall (13) of the differential housing casting (1) through the sprue neck (21), the sprue (2) is further provided with a sprue extension (22) above the sprue neck (21), the sprue extension (22) is arranged extending towards the differential housing casting (1), the position of the end of the sprue extension (22) close to the differential housing casting (1) corresponds to the lock pin hole area (12) and the lower part of the shaft head (11), the sprue extension (22) and the differential housing casting (1) have a gap (3) therebetween.
2. The mold structure for casting an automobile differential case according to Claim 1, wherein The shape of the end of the sprue extension (22) close to the differential housing casting (1) matches the shape of the outer side of the differential housing casting (1).
3. The mold structure for casting the automobile differential case according to Claim 1, wherein Further comprising a first sand core (41), the first sand core (41) matches the outer side of the shaft head (11) and the lock pin hole area (12) of the differential housing casting (1), the first sand core (41) separates the sprue extension (22) from the differential housing casting (1) to form the gap (3) between the sprue extension (22) and the differential housing casting (1) after pouring.
4. The mold structure for casting of an automobile differential case according to Claim 3, wherein Further comprising a second sand core (42), the second sand core (42) is located on the outer side of the side wall (13) of the differential housing casting (1) and in the inner cavity of the differential housing casting (1).
5. The mold structure for casting an automobile differential case according to Claim 4, wherein Further comprising a third sand core (43), the third sand core (43) is located below the second sand core (42), the third sand core (43) corresponds to the cavity structure below the side wall (13) of the differential housing casting (1).
6. The mold structure for casting an automobile differential case according to any one of claims 1 to 5, characterized by, The width of the gap (3) between the sprue extension (22) and the differential housing casting (1) is 5mm.
7. The mold structure for casting the automobile differential case according to any one of claims 1 to 5, characterized by, Further comprising a gating system, the gating system comprises a sprue cup (51), the axis of the sprue cup (51) is vertically arranged, the axis of the differential housing casting (1) is vertically arranged.
8. The mold structure for casting of an automobile differential case according to claim 7, characterized by A vertical main runner (52) is connected below the sprue cup (51), a plurality of horizontal sub-runners (53) are connected to the lower end of the main runner (52), the sub-runners (53) are connected with the sprues (2) and / or the differential housing castings (1).
9. The mold structure for casting the automobile differential case according to Claim 8, wherein The sub-runners (53) are only connected with the sprues (2).
10. The mold structure for casting the automobile differential case according to Claim 8, wherein The differential housing castings (1) are arranged in a ring around the outside of the main runner (52), there is one sprue (2) between two adjacent differential housing castings (1), each sprue (2) has two sprue necks (21) and two sprue extensions (22).