CN103658535A

CN103658535A - Investment casting process of large copper impeller

Info

Publication number: CN103658535A
Application number: CN201410003488.3A
Authority: CN
Inventors: 王桂青; 刘燕; 任国成
Original assignee: Shandong Jianzhu University
Current assignee: Shandong Jianzhu University
Priority date: 2014-01-06
Filing date: 2014-01-06
Publication date: 2014-03-26

Abstract

The invention provides an investment casting process of a large copper impeller, wherein a fusible mould module is formed by welding and combining the fusible mould of a direct sprue and riser wax mould and that of an impeller, and a combination method comprises the following steps that the direct sprue and riser wax mould is on the opposite of an impeller disc; a shell which is manufactured by the shell hanging of the fusible mould is roasted, packed and cast, wherein a packing material is divided into three layers; a cold iron plate is arranged at the bottom of a sand box; the shell is placed on the cold iron plate; the lower part of the shell is a copper impeller body, and dry sand is filled around; the upper part of the shell is a cast riser, and an aluminum silicate heat insulation material layer is filled around. The three-layer packing structure helps to form sequential solidification from bottom to top, and the feeding role of a riser is fully played; the impeller disc is arranged at the bottom of a cast position, can be contacted with cold iron, is first solidified, and molten metal at the upper part is fully fed. If a large copper impeller casting is produced by a process scheme provided by the invention, the finished product rate of the casting can reach 98 percent.

Description

A kind of full form casting process of large-scale copper impeller

Technical field

The present invention relates to model casting field, especially the model casting of copper impeller casting.

Background technology

Model casting is a kind of special precision casting technique, is applicable to various alloy materials, high for dimension precision requirement, and casting structure is complicated, and unmanageable part, is particularly suitable for producing with model casting.

The technological process of model casting is: the assembling → hanging sand → dewaxing → Baking → cast of wax-pattern compacting → wax-pattern, wherein wax-pattern packaging technology and shell cooling condition have important impact to casting quality.

Certain large-scale copper impeller casting, blade dimensions precision and surface roughness require high, with model casting, produce, background production technology is: the easy fusible pattern of low temperature mould material, silicasol case, wax-pattern packaging technology as shown in Figure 1, the sprue rising head (2) of holding concurrently is positioned at hub disk (B) side, and roasting cast after dry sand is filled out in shell vanning; By background production technology, produce, the main waste product defect of copper impeller casting is that wheel disc (B) locates to occur serious shrinkage depression, and shown in the S of Fig. 1, percent defective reaches 50%.

Summary of the invention

In order to solve the wheel disc shrinkage depression waste product problem of above-mentioned large-scale copper impeller casting, the invention provides a kind of improved copper impeller full form casting process.

The present invention for the technical scheme that solves its technical problem and provide is: a kind of improved large-scale copper impeller wax-pattern packaging technology and shell vanning technique, wax-pattern packaging technology of the present invention as shown in Figure 2, impeller hub centre bore (D) directly casts out, and the sprue rising head (2) of holding concurrently is positioned at the opposite of hub disk (B); After Baking, case, vanning figure as shown in Figure 3, shell after high-temperature roasting (1) is put into sandbox (2), wherein packing material is divided into three layers, and chill plate (5) is placed in sandbox bottom, and chill plate (5) is laid shell (2) above, shell bottom is copper impeller body position, fill out dry sand (4) around, shell top is dead head position, fills out aluminum silicate insulation material layer (3) around.

The invention has the beneficial effects as follows: three layers of vanning structure are conducive to form consecutive solidification from bottom to top, give full play to the feeding effect of rising head; Hub disk is positioned at the bottom of pouring position, contacts with chill, first solidifies, and can obtain the abundant feeding of upper metal liquid; Impeller hub central bore casts out, and has reduced the thermal center area of a circle, has improved technique recovery rate simultaneously, has reduced processing capacity.Utilize process program provided by the invention to produce certain large-scale copper impeller casting, hub disk shrinkage depression defect disappears, and casting yield reaches 98%.

Accompanying drawing explanation

Fig. 1 is the large-scale copper impeller of background technology wax-pattern packaging technology figure

(1) copper impeller in figure, (2) sprue rising head of holding concurrently, A. copper impeller hub position, B. copper hub disk position, C. copper impeller blade position

Fig. 2 is the large-scale copper impeller of the present invention wax-pattern module group assembling artwork

(1) copper impeller in figure, (2) sprue rising head of holding concurrently, A. copper impeller hub position, B. copper hub disk position, C. copper impeller blade position, D. copper impeller hub endoporus

Fig. 3 is the large-scale copper impeller of the present invention investment casting shell vanning figure

(1) shell in figure, (2) sandbox, (3) aluminum silicate insulation material, (4) dry sand, (5) chill plate

The specific embodiment

The compacting of wax-pattern and welding: suppress respectively copper impeller body wax-pattern and the sprue rising head wax-pattern of holding concurrently, the rising head wax-pattern (2) of then sprue being held concurrently welds together by shown in Fig. 2 with copper impeller wax-pattern (1): the sprue rising head wax-pattern (2) of holding concurrently is positioned at the opposite of hub disk (B);

Shell processed: technique is prepared shell routinely, shell dewaxing;

Baking, vanning, cast: by dewaxing after shell routinely technique carry out high-temperature roasting, then by shown in Fig. 3, case: first roasting shell (1) is placed into the chill plate (5) of sandbox (2) above, shell (1) top is built with asbestos board, start to fill out dry sand, after dry sand fills up copper impeller housing around, recycle silicon acid aluminum fiber material fills up rising head around, then pours into a mould.

Claims

1. the full form casting process of a large-scale copper impeller, comprise compacting, wax-pattern assembling, shell processed, Baking and the cast of wax-pattern, it is characterized in that: the sprue rising head wax-pattern of holding concurrently is positioned at the opposite of copper hub disk, vanning cast after Baking, packing material is divided into three layers, and chill plate is placed in sandbox bottom, above chill plate, lays shell, shell lower copper impeller is filled out dry sand around, and shell top dead head is filled out aluminum silicate insulation material layer around.