1. Pattern design
Pattern is the process equipment used to form the mold cavity. Pattern directly affects the geometric shape, dimensional accuracy, surface accuracy, internal quality, production efficiency and economy of the casting. The gear oil pump is used for mass production of small castings, and the solid structure pattern is selected, so the wood pattern is selected. The wood pattern has the advantages of light weight, short production cycle, easy processing and molding, convenient use, and low price.
2. Sand box design
2.1 Size of sand box
According to the sand consumption, the height of the sand box is 180 mm. Frame size in sand box (length × The determination of width) is related to the size of the pattern, the number of castings placed in the box, the size and position of the gating system and the amount of sand. The length and width of the sand box of the designed gear oil pump shall be a multiple of 50mm or 100mm, and the height shall be a multiple of 20mm or 50mm. To sum up, the length of the sand box is 400 mm and the width is 250 mm.
2.2 Box wall structure
Simple sand box for manual molding is adopted. Generally, thick straight box wall is adopted, without inner and outer flanges, which is easy to make and easy to drop sand.
2.3 Sand box positioning
Because of the manual modeling, the positioning pin is used to locate the sand box for the pin.
3. Sand core design
The fixing and positioning part of the sand core used in casting is called the core head, which refers to the sand core part that does not contact with the metal and extends out of the casting.
The core head only plays the role of fixing and positioning the sand core in the mold cavity. The simple sand core has only one core head, and the complex sand core has two or more core heads. The diameter of sand core in the design is large, so 1 core head is selected. The core head and core base size shall match each other to ensure the correct installation of sand core. Design of vertical core head: the core head placed vertically in the sand mold is called vertical core head.
3.1 Core head height
In the design, the diameter of sand core is φ 86 mm, without upper core head.
According to Table 6.17 of Foundry Technology, the height of lower core head is 20~25 mm, and its height is 20 mm.
3.2 Core head inclination
According to Table 6.18 of Foundry Technology, if the height of the lower core head is 20mm, the slope is 5 °.
3.3 Core head clearance
For the convenience of core removal, a space is usually reserved between the core head and the core base
Gap. According to Table 6.19 of Foundry Technology, the type of casting mold is wet
The gap is 0.5 mm.