Core assembling method using ceramil wool and multi control valve manufacturing method using the same

Abstract

The present invention relates to a core assembly method using ceramic wool to minimize the occurrence of burrs within a valve and a method for manufacturing a multi-control valve using the same. The core assembly method comprises the steps of: forming a first divided core and a second divided core, respectively, by joining them so as to be stacked vertically to form a single core; stacking ceramic wool of the same cross-section on a plurality of second joining portions of the second divided core to the first divided core; and stacking the first divided core on the second divided core, wherein a plurality of first joining portions that are vertically joined to the plurality of second joining portions are each stacked on the plurality of second joining portions using the ceramic wool as a medium. According to this, as the ceramic wool interposed at the joint between the divided cores in the molding die possesses refractory properties, it does not burn due to the high-temperature molten metal and maintains its shape, thereby preventing the phenomenon of molten metal penetration, and preventing the formation of burrs in the connecting passage formed by the joint between the divided cores in the multi-control valve after casting is completed.

Description

Technology Field

[0001] The present invention relates to a method for assembling a core for casting a multi-control valve for construction machinery, and more specifically, to a method for assembling a core using ceramic wool to minimize the occurrence of burrs within the valve, and a method for manufacturing a multi-control valve using the same. Background Technology

[0002] Generally, since all movements of construction machinery such as excavators and cranes are controlled by hydraulic valves, these hydraulic valves are referred to as the brain nerves of the construction machinery. Recently, hydraulic valves applied to high-capacity construction machinery, such as 90-ton class excavators, are manufactured as so-called multi-control valves in which multiple valves are integrated into a single body.

[0003] Therefore, as shown in FIG. 1, the multi-control valve (10) has an internal structure in which a number of fluid passages are intricately intertwined, so a core of a complex shape must be inserted into the mold for casting.

[0004] At this time, considering the complexity of the core structure, conventionally, a method of assembling two or more divided cores (21, 22) by bonding them together as shown in FIG. 2, that is, a method of applying an adhesive (30) to the joint area between the divided cores (21, 22) and attaching them to each other through this medium was used.

[0005] However, in the casting environment inside the mold, the adhesive (30) of the joint area was burned and lost due to the high-temperature molten metal, causing the molten metal to penetrate. As a result, as shown in FIG. 3, a burr formed in the connecting passage (11, 12) formed by the split core (21, 22) in the cast multi-control valve (10), causing a problem of blocking the flow path.

[0006] Furthermore, there was a problem that it was practically impossible to remove the burr because the above connecting passages (11, 12) were located in the deep part of the valve (10). The problem to be solved

[0007] Accordingly, the objective of the present invention is to provide a method for assembling cores that can prevent the occurrence of burrs at the connection points between divided cores during casting, and a method for manufacturing a multi-control valve using the same. means of solving the problem

[0008] To achieve the above objective, the present invention provides a method for assembling a core, comprising the steps of: forming a first divided core and a second divided core, respectively, by joining them so as to be stacked vertically to form a single core; stacking a ceramic wool of the same cross-section on a plurality of second joining portions of the second divided core to the first divided core; and stacking the first divided core on the second divided core, wherein a plurality of first joining portions that are joined vertically to the plurality of second joining portions are each stacked on the plurality of second joining portions via the ceramic wool.

[0009] Here, the assembly method of the core may further include the step of fixing the vertically stacked state between the first and second divided cores by attaching a pair of mold fixing frames, consisting of left and right sides, to both the left and right sides of the vertically stacked first and second cores.

[0010] Meanwhile, to achieve the above objective, the present invention provides a method for manufacturing a multi-control valve for construction machinery, characterized by comprising the steps of: inserting a core assembled by the assembly method described above into a space within a mold; injecting and cooling molten metal into the mold in which the core is inserted; and withdrawing the casting from the mold and removing the core. Effects of the invention

[0011] As described above, according to the core assembly method and the method for manufacturing a multi-control valve using the same according to the present invention, the ceramic wool interposed at the joint portion between divided cores in the casting environment within the mold has refractory properties, so it does not burn due to the high-temperature molten metal and maintains its shape, thereby preventing the phenomenon of molten metal penetration. Consequently, it is possible to prevent the formation of burrs in the connecting passage formed by the joint portion between the divided cores in the multi-control valve after casting is completed. Brief explanation of the drawing

[0012] FIG. 1 is a perspective view of a multi-control valve according to the prior art, FIG. 2 is a partial enlarged view of a core according to the prior art, FIG. 3 is a cross-sectional view of the multi-control valve of FIG. 1, FIGS. 4 and 5 are schematic diagrams of the steps of a core assembly method according to an embodiment of the present invention. FIG. 6 is a flowchart of a method for manufacturing a multi-control valve according to an embodiment of the present invention, FIG. 7 is a perspective view and an internal enlarged view of a multi-control valve manufactured according to an embodiment of the present invention. Specific details for implementing the invention

[0013] A core assembly method according to an embodiment of the present invention, as shown in FIG. 4, involves forming a second divided core (42) that forms the lower part of the core, placing it on the floor, and then stacking ceramic wool (50) on each of the multiple joining parts (42a) formed on the top. The ceramic wool (50) has the same cross-section as the joining part (42a) and is made of a uniform thickness.

[0014] Next, the first divided core (41) forming the upper part of the core is stacked on the second divided core (42) as shown in 5. At this time, a plurality of connecting parts (41a) formed at the bottom of the first divided core (41) are stacked so that they each correspond to a plurality of connecting parts (42a) formed at the top of the second divided core (42). Accordingly, the upper and lower connecting parts (41a, 42a) are stacked so that their cross-sections match through a ceramic wool (50).

[0015] Meanwhile, since the multiple ceramic wools (50) mediating between the upper and lower split cores (41, 42) do not have adhesive properties, a pair of left and right mold fixing frames (61, 62) for fixing the stacked split cores (41, 42) are attached to both the left and right sides of the stacked split cores (41, 42). On the inner surface of each mold fixing frame (61, 62), an upper coupling groove (61a, 62a) and a lower coupling groove (61b, 62b) are formed to insert and connect the side portions of the upper and lower split cores (41, 42), thereby fixing the connection state of the upper and lower stacked split cores (41, 42) through these.

[0016] The core (40), formed by combining and fixing the upper and lower divided cores (41, 42) as described above, is first inserted into a mold for casting a multi-control valve as shown in FIG. 6 (S1), and then molten metal is injected into the mold and then cooled (S2). The casting obtained after cooling is withdrawn from the mold, and then the core, which is filled to form an internal flow path, is removed, thereby completing the molding of the multi-control valve (70 in FIG. 7).

[0017] When examining the screen of the multi-control valve (70) formed in this manner, as shown in the enlarged view of FIG. 7, it can be confirmed that a smooth flow path (71) is formed at the connection point between the split cores (41, 42), that is, at the point mediated by the ceramic wool (50).

[0018] Meanwhile, the assembly method of the core and the manufacturing method of the multi-control valve described above are merely examples to aid in understanding the present invention, and therefore the scope of rights or technical scope of the present invention, as defined by the claims or equivalents described below, is not limited to what has been described above. Explanation of the symbols

[0019] 40: Medium 41: First dividing middleman 41a: Connection site 42: Second partitioner 42a: Connection site 50: Ceramic wool 61, 62: Mold fixed frame 61a, 62a: Upper coupling groove 61b, 62b: Lower coupling groove 70: Multi-control valve 71: Euro

Claims

Claim 1 delete Claim 2 A method for assembling cores, comprising the steps of: forming a first divided core and a second divided core, respectively, by combining them to form a single core by stacking them vertically; stacking ceramic wool of the same cross-section on a plurality of second connecting portions of the second divided core to the first divided core; stacking the first divided core onto the second divided core, wherein a plurality of first connecting portions that are vertically connected to the plurality of second connecting portions are stacked on the plurality of second connecting portions using the ceramic wool as a medium; and further comprising the step of fixing the vertically stacked state between the first and second divided cores by attaching a pair of mold fixing frames to both the left and right sides of the vertically stacked first and second divided cores. Claim 3 delete Claim 4 A method for manufacturing a multi-control valve for construction machinery, comprising the steps of: inserting a core assembled by the assembly method of claim 2 into a space within a molding die together with a fixed frame inside the mold; injecting and cooling molten metal into the molding die into which the core is inserted; and withdrawing the casting from the molding die and removing the core.

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