CN1041716A

CN1041716A - Precision casting technology for die impression

Info

Publication number: CN1041716A
Application number: CN 88109110
Authority: CN
Inventors: 刘钟嶽
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-10-08
Filing date: 1988-10-08
Publication date: 1990-05-02

Abstract

The present invention relates to a kind of technology that adopts casting method mfg. moulding die die cavity.The method of existing mfg. moulding die is to adopt machining.Also have and adopt the casting method mfg. moulding die, process the press-moulding die of a mold cavity conjugation earlier with machining process but still need.Such processing method increases and time-consuming taking a lot of work the cost of mould.The present invention directly makes product as the press-moulding die molded surface, makes the mould material with expandable polystyrene and makes fusible pattern, and cost is reduced greatly, makes generally to make the hot investment casting mfg. moulding die become possibility.

Description

Precision casting technology for die impression

The present invention relates to a kind of technology that adopts casting method mfg. moulding die die cavity.

Disclose a kind of technology with the hot investment casting mfg. moulding die on the United States Patent (USP) 4220190, this technology is to make the press-moulding die of a mold cavity earlier, makes fusible pattern with press-moulding die, with heat proof material fusible pattern is wrapped, again fusible pattern is removed, form casting cavity, cast then.The press-moulding die that this technology is used is to adopt machining process to make, thereby the degree true to nature of processing is difficult to guarantee.General mold cavity output is little, and many all is single-piece production, thereby press-moulding die is general only with once, causes cost height, waste so greatly.This is an one of the main reasons of failing to realize popularizing use hot investment casting mfg. moulding die die cavity so far.The cured matrix manufacturing fusible pattern of this process using, cured basic fusible pattern will produce certain contraction, when making the large mold die cavity, will produce bigger error.And use paraffin wax also to need large-scale temperature control to melt cured equipment, increased investment.Adopting paraffin wax to make fusible pattern is to fail to realize the main cause that large mold is made with hot investment casting.Bury generally employing type of the filler sand that fusible pattern is used, the husky hot coefficient of type is little, and heat radiation is slow, makes the metal grain of foundry goods bigger, and this makes the undercapacity of mold cavity.

The objective of the invention is to overcome above-mentioned the deficiencies in the prior art and a kind of improved precision casting technology for die impression is provided, it has precision height, characteristics that cost is low.

The precision casting process that the present invention adopts is: do a mold cavity press-moulding die earlier, make fusible pattern with press-moulding die, hanging on fusible pattern forms shell, and the fusible pattern after the hanging is imbedded in the filler, and take out casting, cooling back.Its special character is: the molded surface of mold cavity press-moulding die directly uses sample, and the mould material of making fusible pattern adopts expandable polystyrene, and filler adopts shot.

Directly the method for making the press-moulding die molded surface with sample can be, elder generation imbeds half of sample in the sand, on the sapin face, brush waterglass liquid, irritate gypsum at sample on second half, after the gypsum sets, half of sample is embedded in the gypsum, removes sand and waterglass liquid layer, makes press-moulding die molded surface and die joint.

The present invention compared with prior art has following advantage:

1。Directly adopt sample to make the press-moulding die molded surface, saved the machining operation, especially solved difficulty large-scale, complicated, the manufacturing of single-piece mold cavity, improved the precision and the degree true to nature of mold cavity, cost is low, and save time, material-saving, province's energy.

2。Adopt foaming mould material to make fusible pattern, especially adopt expandable polystyrene, good water absorption, structural strength is higher, shrinks for a short time, and can be full of framed interior space fully with certain pressure, has improved casting accuracy and degree true to nature.

3. adopt shot to make filler, the hot coefficient of shot is big, and leaves bigger space between the shot, rapid heat dissipation, refinement casting crystalline grain, improved intensity.

Accompanying drawing and drawing are described as follows:

Fig. 1 is the three-view diagram of sample;

Fig. 2 is the sample three-view diagram that buries behind the sand;

Fig. 3 is the sample front view behind the filling gypsum;

Fig. 4 is the sample front view that takes off behind the sand;

Fig. 5 be put combination framed, put into the sample side view behind the foaming mould material;

Fig. 6 is for feeding the sample side view after steam mould material expands;

Fig. 7 is fusible pattern figure;

Fig. 8 sloughs the gypsum of fusible pattern and the side view of sample;

The shell figure of Fig. 9 for forming after the hanging;

Figure 10 is shell and the fusible pattern figure that is embedded in the shot;

The present invention will be described in further detail embodiment in conjunction with the accompanying drawings.

Fig. 1 has represented the three-view diagram of sample.At first change line on sample, line 1 is a parting line, and it is one fen two halves of sample, and A is a duplicate surface, and B is a non duplicate surface.Line 2 is the allowance line.

In Fig. 2, the duplicate surface A of sample is buried by sand 3, and the face that sands flat is concordant with allowance line 2, brushes glass metal on the face of sanding flat, and is level and smooth to guarantee the face that sands flat.

In Fig. 3, on non-system face B, put grouting frame 4, in frame, pour calcium plaster 5 into, after gypsum 5 solidifies, sample is fixed on the gypsum.

In Fig. 4, remove grouting frame 4 after the gypsum sets, and sample and gypsum are turned over together, remove sand and waterglass liquid layer, with the equating of gypsum plane, form gypsum die joint and press-moulding die molded surface.

In Fig. 5, it is framed 6 to put die mould on duplicate surface A, on die mould is framed many air-vents is arranged.Put into a certain amount of expandable polystyrene 7 in die mould is framed, the amount of polystyrene can be calculated in advance, can be full of whole die mould framed 6 after guaranteeing to expand.

In Fig. 6, sample, gypsum 5, die mould framed 6 and expandable polystyrene 7 are put into steam chest 8, and feeding steam, expandable polystyrene 7 expands under the heating of steam, and it is framed to be full of whole die mould with certain pressure, it can guarantee that the sample surfaces and the sample surfaces that form are just the same on fusible pattern, improved degree true to nature.

Fig. 7 has represented to make the fusible pattern that the mould material forms with expandable polystyrene 7.

Fig. 8 has represented to take off sample and the gypsum behind the fusible pattern.

In Fig. 9, hanging on fusible pattern forms shell 9, and shell 9 forms for the dried back of slurries that makes in the common hot investment casting.

In Figure 10, the fusible pattern after the hanging is put into sandbox 11, and bury with shot 10, to cast then, the fusible pattern by polystyrene 7 is made after running into molten iron, is fused into gas, runs away from the pore that is stayed.Shot 10 has not only play a part to reinforce shell 9, and the more important thing is has increased radiating rate, makes the grain refinement of foundry goods, has improved intensity.After the casting cooling, take out foundry goods, just become a mold cavity, finish the technology of hot investment casting mfg. moulding die die cavity.

In above-mentioned technology, can also after hanging, carry out roasting to the fusible pattern that has shell, can strengthen the intensity of shell like this.In roasting, the polystyrene fusible pattern is run away gasification, forms a casting cavity.Then shell is imbedded and burnt casting in the shot.

Claims

1, a kind of precision casting technology for die impression, its technical process is, does a mold cavity press-moulding die earlier, makes fusible pattern with press-moulding die, hanging on fusible pattern, form shell, the fusible pattern after the hanging is imbedded in the filler, take out casting, cooling back, it is characterized in that, the molded surface of mold cavity press-moulding die directly uses sample, and the mould material of making fusible pattern adopts expandable polystyrene, and filler adopts shot.

2, according to the described precision casting technology for die impression of claim 1, it is characterized in that, directly the method for doing the press-moulding die molded surface with sample is, earlier half of sample imbedded in the sand, on the face of sanding flat, brushed waterglass liquid, irritate gypsum on second half at sample, after the gypsum sets, half of sample is embedded in the gypsum, removes sand and waterglass liquid layer, makes press-moulding die molded surface and die joint on gypsum.