Shell core structure of bottom fork sand core

Abstract

A shell core structure of a bottom fork sand core comprises a bottom fork sand core upper shell core and a bottom fork sand core lower shell core, the front end of the bottom fork sand core upper shell core is a first bottom fork head forming part, the middle of a first bottom fork plug forming part is a first auxiliary positioning part, and the rear end of the bottom fork sand core upper shell core is a first bottom fork double-fork-arm forming part. A first positioning part is arranged in the middle of the first bottom fork double-fork-arm forming part, a first weight reduction groove which is concave inwards is formed in the bottom fork sand core upper shell core, a second bottom fork head forming part is arranged at the front end of the bottom fork sand core lower shell core, and a second auxiliary positioning part is arranged in the middle of the second bottom fork plug forming part. The rear end of the bottom fork sand core lower shell core is a second bottom fork double-fork-arm forming part, the middle part of the second bottom fork double-fork-arm forming part is a second positioning part, the inner part of the bottom fork sand core lower shell core is a second weight reduction groove which is concave inwards, and the bottom fork sand core upper shell core and the bottom fork sand core lower shell core are mutually connected and fixed to form the bottom fork sand core.

Description

Technical Field

[0001] This utility model relates to the field of flat fork sand cores, specifically to the shell-core structure of flat fork sand cores. Background Technology

[0002] The swingarm is one of the most important components of a motorcycle. After lightweight design, swingarm parts are all hollow structures internally while maintaining overall vehicle strength. In the casting process design of swingarm components, the hollow internal structure is formed using sand cores. Currently, the sand cores used in swingarm casting are solid structures. This structure significantly increases the weight of the sand core, consequently increasing the cost of coated sand. Furthermore, solid sand cores increase the amount of combustion gases generated by the coated sand during casting, and these gases cannot be effectively expelled.

[0003] Therefore, the structure of the flat fork sand core needs to be improved. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a shell-core structure for flat fork sand cores. This type of flat fork sand core is lightweight, and the cost of using coated sand is lower.

[0005] The purpose of this utility model is achieved by the following solution: a shell-core structure for a flat fork core, comprising an upper shell core and a lower shell core. The front end of the upper shell core is a first flat fork fork head forming part, the middle part of the first flat fork plug forming part is a first auxiliary positioning part, the rear end of the upper shell core is a first flat fork double fork arm forming part, the middle part of the first flat fork double fork arm forming part is a first positioning part, and the interior of the upper shell core is an inwardly recessed first weight-reducing groove. The front end of the lower shell core is a second flat fork fork head forming part, the middle part of the second flat fork plug forming part is a second auxiliary positioning part, the rear end of the lower shell core is a second flat fork double fork arm forming part, the middle part of the second flat fork double fork arm forming part is a second positioning part, and the interior of the lower shell core is an inwardly recessed second weight-reducing groove. The upper shell core and the lower shell core are connected and fixed to each other to form a flat fork core.

[0006] The lower end face of the shell wall at the connection point of the upper shell of the flat fork sand core is provided with a connecting protrusion surrounding the upper shell of the flat fork sand core, and the upper end face of the shell wall at the connection point of the lower shell of the flat fork sand core is provided with a connecting groove surrounding the lower shell of the flat fork sand core. The connecting protrusion is installed in the connecting groove to form a stop structure, thereby connecting and fixing the upper shell of the flat fork sand core and the lower shell of the flat fork sand core.

[0007] A first reinforcing protrusion is provided in the middle of the first weight-reducing groove of the upper shell core of the flat fork sand core, and a second reinforcing protrusion is provided in the middle of the second weight-reducing groove of the lower shell core of the flat fork sand core.

[0008] The shell wall thickness of the upper shell of the flat fork sand core is 5-15mm, and the shell wall thickness of the lower shell of the flat fork sand core is 5-15mm.

[0009] Sand discharge holes are provided between the first positioning part and the second positioning part, as well as between the first auxiliary positioning part and the second auxiliary positioning part.

[0010] Two positioning seats are respectively provided on the bottom two forks of the second flat fork double fork forming part of the flat fork sand core lower shell core.

[0011] The advantages of this utility model are: 1. The overall weight of the sand core is reduced by more than one-third, which reduces the cost of using coated sand.

[0012] 2. The hollow internal structure is conducive to the storage of combustion gases generated during the casting process, which greatly improves the casting qualification rate and thus reduces the overall product production cost. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a schematic diagram of the upper shell core structure of the flat fork sand core;

[0015] Figure 3 This is a schematic diagram of the lower shell core structure of the flat fork sand core;

[0016] Figure 4 This is a cross-sectional view of the present invention;

[0017] Figure 5 This is a schematic diagram of the bottom structure of the lower shell core of the flat fork sand core. Detailed Implementation

[0018] like Figures 1 to 5As shown, a shell-core structure for a flat fork core includes an upper shell core 1 and a lower shell core 2. The front end of the upper shell core 1 is a first flat fork fork head forming part 1-1, the middle part of the first flat fork head forming part 1-1 is a first auxiliary positioning part 1-4, the rear end of the upper shell core 1 is a first flat fork double fork arm forming part 1-2, and the middle part of the first flat fork double fork arm forming part 1-2 is a first positioning part 1-3. The interior of core 1 has an inwardly recessed first weight-reducing groove 3. The front end of the lower shell core 2 of the flat fork core is a second flat fork fork head forming part 2-1, the middle part of the second flat fork head forming part 2-1 is a second auxiliary positioning part 2-4, the rear end of the lower shell core 2 of the flat fork core is a second flat fork double fork arm forming part 2-2, the middle part of the second flat fork double fork arm forming part 2-2 is a second positioning part 2-3, and the interior of the lower shell core 2 of the flat fork core has an inwardly recessed second weight-reducing groove 4. The lower end face of the shell wall at the connection point of the upper shell core 1 of the flat fork core is provided with a connecting protrusion 1-5 surrounding the upper shell core 1 of the flat fork core, and the upper end face of the shell wall at the connection point of the lower shell core 2 of the flat fork core is provided with a connecting groove 2-5 surrounding the lower shell core 2 of the flat fork core. The connecting protrusion 1-5 is installed in the connecting groove 2-5 to form a stop structure, connecting and fixing the upper shell core 1 and the lower shell core 2 of the flat fork core to form the flat fork core. A first reinforcing protrusion 3-1 is provided in the middle of the first weight-reducing groove 3 of the upper shell core 1 of the flat fork sand core, and a second reinforcing protrusion 4-1 is provided in the middle of the second weight-reducing groove 4 of the lower shell core 2 of the flat fork sand core. The reinforcing protrusions can increase the strength of the sand core shell. The shell wall thickness of the upper shell core 1 of the flat fork sand core is 5-15mm, and the shell wall thickness of the lower shell core 2 of the flat fork sand core is 5-15mm. The thickness of the sand core shell is adjusted according to different casting products. A sand discharge hole 5 is provided between the first positioning part 1-3 and the second positioning part 2-3, and between the first auxiliary positioning part 1-4 and the second auxiliary positioning part 2-4. Two positioning seats 2-6 are respectively provided on the two forks at the bottom of the second flat fork double fork arm forming part 2-2 of the lower shell core 2 of the flat fork sand core. The positioning seats 2-6 are used for height positioning of the sand core.

[0019] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications made to the present utility model by those skilled in the art without departing from the spirit of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A shell-core structure for a flat-forked sand core, characterized in that: The system includes a flat fork core upper shell (1) and a flat fork core lower shell (2). The front end of the flat fork core upper shell (1) is a first flat fork fork head forming part (1-1), the middle part of the first flat fork head forming part (1-1) is a first auxiliary positioning part (1-4), the rear end of the flat fork core upper shell (1) is a first flat fork double fork arm forming part (1-2), the middle part of the first flat fork double fork arm forming part (1-2) is a first positioning part (1-3), and the interior of the flat fork core upper shell (1) is an inwardly recessed first weight-reducing groove (3). The front end of the lower shell core (2) is the second flat fork fork head forming part (2-1), the middle part of the second flat fork plug forming part (2-1) is the second auxiliary positioning part (2-4), the rear end of the flat fork sand core lower shell core (2) is the second flat fork double fork arm forming part (2-2), the middle part of the second flat fork double fork arm forming part (2-2) is the second positioning part (2-3), the interior of the flat fork sand core lower shell core (2) is the inwardly recessed second weight reduction groove (4), the flat fork sand core upper shell core (1) and the flat fork sand core lower shell core (2) are connected and fixed to each other to form the flat fork sand core.

2. The shell-core structure of the flat fork sand core according to claim 1, characterized in that: The lower end face of the shell wall at the connection point of the upper shell core (1) of the flat fork sand core is provided with a connecting protrusion (1-5) surrounding the upper shell core (1) of the flat fork sand core, and the upper end face of the shell wall at the connection point of the lower shell core (2) of the flat fork sand core is provided with a connecting groove (2-5) surrounding the lower shell core (2) of the flat fork sand core. The connecting protrusion (1-5) is installed in the connecting groove (2-5) to form a stop structure, thereby connecting and fixing the upper shell core (1) of the flat fork sand core and the lower shell core (2) of the flat fork sand core.

3. The shell-core structure of the flat fork sand core according to claim 1, characterized in that: A first reinforcing protrusion (3-1) is provided in the middle of the first weight-reducing groove (3) of the upper shell core (1) of the flat fork sand core, and a second reinforcing protrusion (4-1) is provided in the middle of the second weight-reducing groove (4) of the lower shell core (2) of the flat fork sand core.

4. The shell-core structure of the flat fork sand core according to claim 1, characterized in that: The shell wall thickness of the upper shell core (1) of the flat fork sand core is 5-15 mm, and the shell wall thickness of the lower shell core (2) of the flat fork sand core is 5-15 mm.

5. The shell-core structure of the flat fork sand core according to claim 1, characterized in that: Sand discharge holes (5) are provided between the first positioning part (1-3) and the second positioning part (2-3) and between the first auxiliary positioning part (1-4) and the second auxiliary positioning part (2-4).

6. The shell-core structure of the flat-forked sand core according to claim 1, characterized in that: Two positioning seats (2-6) are respectively provided on the bottom two forks of the second flat fork double fork forming part (2-2) of the flat fork sand core lower shell core (2).

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