Composite core

Abstract

The invention discloses a composite core which is characterized in that a carbonizable layer or a thermoplastic plastic layer or a solidified glue layer is arranged on the outer side of an inner core bearing shrinkage pressure of a metal casting and forging piece, and a high-temperature-resistant delayed heat conduction layer is arranged on the contact surface of the inner core and metal to jointly form a combined core. The high-temperature-resistant delay heat conduction layer is in contact with high-temperature molten metal, when the mold is pressurized, the carbonizable layer, the thermoplastic plastic layer or the curing glue layer can bear pressure, and after pressurization is completed, heat in the molten metal is conducted to the carbonizable layer, the thermoplastic plastic layer or the curing glue layer through the high-temperature-resistant delay heat conduction layer to carbonize the carbonizable layer respectively. The inner core is easy to take out when the thermoplastic plastic layer is melted and the glue layer is solidified to lose efficacy, and the inner core can also be taken out after being heated after being demoulded, and can be used for liquid die casting, die casting or low-pressure and gravity casting.

Description

Technical Field

[0001] The invention relates to a core for liquid or semi-solid metal molding, in particular to a composite core. Background Art

[0002] In metal casting, liquid metal forging, and die-casting processes, many hollow structures require core shaping. Existing core materials often use sand core structures in gravity and low-pressure casting, which are contaminated after molding and during processing. Liquid metal forging and die-casting processes must use mold steel and must be preheated during use. In particular, the liquid metal forging process requires a large draft angle to complete the process smoothly. When a workpiece with multiple internal cavities is required, it is difficult to complete. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides a composite core, which can effectively solve the deficiencies in the prior art.

[0004] The present invention is achieved through the following technical solutions: a composite core, consisting of an inner core, a carbonizable layer, and a high-temperature resistant and delayed heat-conducting layer. The outer side of the inner core that bears the shrinkage pressure of the casting and forging is provided with a carbonizable layer, and the outer side of the carbonizable layer and the metal contact surface are provided with a high-temperature resistant and delayed heat-conducting layer.

[0005] As a preferred technical solution, the carbonizable layer is a carbonizable material, such as wood, bamboo chips or biomass materials.

[0006] As a preferred technical solution, the high temperature resistant delayed heat conduction layer is aluminum silicate fiber, asbestos fiber or high temperature resistant coating.

[0007] The composite core of the present invention is composed of an inner core thermoplastic plastic layer and a high-temperature resistant and delayed heat-conducting layer. The outer side of the inner core that bears the shrinkage pressure of the casting and forging is provided with a thermoplastic plastic layer, and the outer side of the thermoplastic plastic layer and the metal contact surface are provided with a high-temperature resistant and delayed heat-conducting layer.

[0008] As a preferred technical solution, the high temperature resistant delayed heat conduction layer is aluminum silicate fiber, asbestos fiber or high temperature resistant coating.

[0009] The composite core of the present invention consists of an inner core solidified glue layer and a high-temperature resistant and delayed heat conduction layer. The outer side of the inner core that bears the shrinkage pressure of the casting and forging is provided with a solidified glue layer, and the outer side of the solidified glue layer and the metal contact surface are provided with a high-temperature resistant and delayed heat conduction layer.

[0010] As a preferred technical solution, the high temperature resistant delayed heat conduction layer is aluminum silicate fiber, asbestos fiber or high temperature resistant coating.

[0011] The beneficial effects of the present invention are as follows: a carbonizable layer or a thermoplastic plastic layer or a solidified glue layer is provided on the outside of the inner core that bears the shrinkage pressure of the metal casting and forging, and a high-temperature resistant delay heat conduction layer is provided on the contact surface with the metal to form a combined core. In the pressure casting or liquid die forging process, the high-temperature molten metal is in contact with the high-temperature molten metal. When the mold is pressurized, the carbonizable layer, the thermoplastic plastic layer or the solidified glue layer can withstand the pressure. When the pressurization is completed, the heat in the molten metal is conducted to the carbonizable layer or the thermoplastic plastic layer or the solidified glue layer through the high-temperature delay heat conduction layer, carbonizing the carbonizable layer, melting the thermoplastic plastic layer, and rendering the solidified glue layer ineffective, so that the inner core is easy to remove. The inner core can also be removed by heating after demolding. It can be used for liquid die casting, die casting or low-pressure, gravity casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1 A three-dimensional diagram of a casting of the present invention;

[0014] Figure 2 A side view of a casting of the present invention;

[0015] Figure 3 Schematic diagram of gravity casting of a casting according to the present invention;

[0016] Figure 4 It is a schematic diagram of liquid die forging of the present invention;

[0017] Figure 5 This is a schematic diagram of liquid die forging in the prior art;

[0018] Figure 6 This is a schematic diagram of a core with a carbonized layer according to the present invention;

[0019] Figure 7 Schematic diagram of a core with a carbonized layer for shrinkage according to the present invention;

[0020] Figure 8 This is a schematic diagram of a core with a taxation layer according to the present invention;

[0021] Figure 9 This is a schematic diagram of a core with a shrinking surface and a glue layer according to the present invention;

[0022] Figure 10 Schematic diagram of a core with a thermoplastic plastic layer according to the present invention;

[0023] Figure 11Schematic diagram of a core with a shrinking surface and a thermoplastic plastic layer according to the present invention;

[0024] Figure 12 Schematic diagram of liquid die forging of multiple upper dies of the present invention;

[0025] Description of reference numerals:

[0026] 1. Metal casting or liquid forging; 2. Sand casting outer mold; 3. Sand casting core; 4. Liquid forging lower mold; 5. Liquid forging upper mold (core); 51. Prior art liquid forging upper mold (core); 6. Composite upper mold inner core; 7. High-temperature resistant heat-conducting delay layer; 8. Carbonizable layer; 9. Shrinkage surface carbonizable layer; 10. Glue curing layer; 11. Shrinkage surface glue curing layer; 12. Thermoplastic plastic layer; 13. Shrinkage surface thermoplastic plastic layer; 14. Multi-mold liquid casting; DETAILED DESCRIPTION

[0027] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.

[0028] Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0029] Example 1

[0030] like Figure 1 The metal casting or forging part is a hollow container-like product with a size of 200mm*200mm*60mm. Figure 4 The figure shows a schematic diagram of liquid die forging, in which 4 is the liquid die forging lower die, 5 is the liquid die forging upper die (core), after the molten metal is poured into the liquid die forging lower die 4, the liquid die forging upper die (core) 5 is pressurized in the lower die under the action of pressure P in the figure to form a metal casting or liquid forging 1, wherein the upper die structure is as shown in FIG. Figure 6As shown, 6 is the composite upper mold core, 7 is the high temperature resistant heat conduction delay layer, 8 is the carbonizable layer, there is a carbonizable layer on the upper mold core, the carbonizable layer is made of carbonizable material, such as wood, cardboard or other carbonizable materials. In this embodiment, 1 mm thick kraft cardboard is used as the carbonizable layer, and the carbonizable layer is wrapped with a layer of high temperature resistant heat conduction delay layer, which is made of heat-resistant material, such as aluminum silicate fiber and other heat-resistant materials. In this embodiment, 1 mm thick aluminum silicate paper is glued to the outside of the carbonizable layer. When the upper mold assembly contacts the metal liquid, the high temperature resistant The heat-resistant temperature of the heat-conducting delay layer is higher than the temperature of the molten metal. At the same time, the pressure die forging is completed before the heat of the molten metal is conducted to the carbonized layer and causes the carbonized layer to be carbonized. When the die forging is completed, the heat in the molten metal is conducted to the carbonizable layer, and the carbonization process of the carbonizable layer begins. After the carbonization of the carbonized layer, the composite upper die inner core 6 is very easy to separate from the metal casting or liquid forging 1. The carbonization process can use the heat of the molten metal itself to be conducted to the carbonized layer through the high-temperature resistant heat-conducting delay layer to carbonize the carbonized layer, or the forging and the upper die can be heated together to carbonize the carbonized layer. Figure 7 The carbonizable layer 9 is present only on the shrinkage surface of the forging, i.e., around the inner core 6 of the composite upper die. Figure 5 The prior art liquid forging upper die (core) 51 shown can set the draft angle to 0°.

[0031] Example 2

[0032] What is different from Example 1 is that the carbonizable layer is made by pulp molding and then bonded to the inner core 6 with glue.

[0033] Example 3

[0034] like Figure 8 As shown, the difference from Example 1 is that the glue curing layer 10 is used instead of Figure 6 The carbonizable layer 8 in the liquid die forging is completed. When the heat of the metal liquid is transferred to the glue solidification layer 10 through the high temperature resistant heat conduction delay layer 7, the glue solidification layer is aged under the action of high temperature, so that the composite upper die inner core 6 is easily separated from the liquid forging 1. Figure 9 Only the periphery of the composite upper mold inner core 6 is provided with a shrinkage surface glue solidified layer 11 .

[0035] Example 4

[0036] like Figure 10 As shown, the difference from Examples 1 and 2 is that a thermoplastic plastic layer 12 is used instead of the carbonizable layer 8 and the glue curing layer 10, and a 1 mm polyethylene heat shrink film is wrapped around the outside of the inner core. Hot air is used to make the heat shrink film adhere tightly to the inner core, and then a 1 mm thick aluminum silicate paper is pasted on the outside. After the liquid die forging is completed, when the heat of the metal liquid is transferred to the thermoplastic plastic layer through the high temperature resistant delay heat conductive layer 7, the thermoplastic plastic layer is melted, making it easy to separate the composite upper die inner core 6 from the liquid forging 1. Figure 11It is a composite upper mold core with a shrinkage surface thermoplastic layer 13.

[0037] Example 5

[0038] like Figure 12 As shown, unlike the above embodiments, it is a schematic diagram of liquid die forging with multiple upper dies, and the composite upper dies are multiple, which respectively shape the metal liquid under pressure and move out from the lower die together with the liquid forging. After moving out, the inner core of each composite upper die is easily separated from the multiple upper die liquid casting 14 due to the carbonization of the carbonizable layer 8 or the failure of the glue curing layer or the melting of the thermoplastic plastic layer.

[0039] Example 6

[0040] The difference from the above embodiments is that it can be the same as gravity pouring and low pressure pouring.

[0041] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined in the claims.

Claims

1. A composite core, characterized in that: It consists of an inner core, a carbonizable layer, and a high-temperature resistant and delayed heat-conducting layer. The outer side of the inner core that bears the shrinkage pressure of the casting and forging is provided with a carbonizable layer, and the outer side of the carbonizable layer and the metal contact surface are provided with a high-temperature resistant and delayed heat-conducting layer.

2. The composite core according to claim 1, characterized in that: The carbonizable layer is a carbonizable material, such as wood or bamboo chips or biomass materials.

3. The composite core according to claim 1, characterized in that: The high temperature resistant delayed heat conduction layer is aluminum silicate fiber, asbestos fiber or high temperature resistant coating.

4. A composite core, characterized in that: It consists of an inner core thermoplastic plastic layer and a high temperature resistant and delayed heat conduction layer. The outer side of the inner core that bears the shrinkage pressure of the casting and forging is provided with a thermoplastic plastic layer, and the outer side of the thermoplastic plastic layer and the metal contact surface are provided with a high temperature resistant and delayed heat conduction layer.

5. The composite core according to claim 4, characterized in that: The high temperature resistant delayed heat conduction layer is aluminum silicate fiber, asbestos fiber or high temperature resistant coating.

6. A composite core, characterized in that: It consists of an inner core solidified glue layer and a high temperature resistant delayed heat conduction layer. The outer side of the inner core that bears the shrinkage pressure of the casting and forging is provided with a solidified glue layer, and the outer side of the solidified glue layer and the metal contact surface are provided with a high temperature resistant delayed heat conduction layer.

7. The composite core according to claim 6, characterized in that: The high temperature resistant delayed heat conduction layer is aluminum silicate fiber, asbestos fiber or high temperature resistant coating.

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