CN101947647B

CN101947647B - Tire mold low-pressure casting method capable of eliminating deformation of patterned ring

Info

Publication number: CN101947647B
Application number: CN2010102748362A
Authority: CN
Inventors: 张灿伟; 王彬; 李强
Original assignee: SHANDONG WANTONG MOULD CO Ltd
Current assignee: SHANDONG WANTONG MOULD CO Ltd
Priority date: 2010-09-02
Filing date: 2010-09-02
Publication date: 2012-09-19
Anticipated expiration: 2030-09-02
Also published as: CN101947647A

Abstract

The invention discloses a tire mold low-pressure casting method capable of eliminating deformation of a patterned ring, which comprises: joining gypsum molds to form a nonstandard round gypsum mold, and positioning the nonstandard round gypsum mold on a lower metal mold of a coasting mold cavity; processing upper and lower horizontal positioning grooves on the external circumference of the gypsum mold; forming the coasting cavity by using the gypsum mold serving as a core mold and upper and lower metal molds, and obtaining an aluminum alloy tire mold casting after molten aluminum is solidified; dividing a tire mold into single patterned block castings; positioning the patterned block castings by a planar positioning reference and a cylindrical positioning reference and machining to obtain standard patterned blocks; and joining the standard patterned blocks by a process device to obtain an entire tire mold. The patterned blocks produced by the method retain the characteristics of uniform chemical ingredients, consistent metallic structure and uniform coefficient of thermal expansion of ring coasting. The gravity block coating mature machining process adopted in a later period greatly improves the overall quality of the mold and obviously reduces cost.

Description

Eliminate the tire-mold low-pressure casting method of pattern ring distortion

Technical field

The present invention relates to a kind of tire-mold low-pressure casting method of eliminating the pattern ring distortion in the aluminium alloy tire-mold low pressure casting field.

Background technology

At present, the production method one of aluminium alloy tire-mold has four kinds, lathe engraving, spark machined, low repoussage circle casting and gravity individual cast.Lathe engraving precision is high, but for complicated a little decorative pattern, it is powerless just to seem, there is a large amount of wedge angle positions in the tire-mold decorative pattern, and circular cutter can't be processed.In addition, the steel disc on the mould is inlayed very difficulty.Though spark machined can partly solve the wedge angle problem, and is powerless equally for intricate detail,, lose precision soon because consumption of electrode is too fast.Electric spark belongs to three-dimensional processing, for the decorative pattern that must carry out the processing of five coordinates, just can only take approximate processing, the tyres for passenger cars mould that can not be used to have relatively high expectations.This method exists steel disc to inlay a difficult problem equally.Whole circle low pressure casting and piecemeal gravitational casting are the methods of extensively taking at present.Theoretically, these two kinds of methods can be produced the complicated arbitrarily tire-mold of decorative pattern, do not exist steel disc to inlay problem.But also there is long-term insurmountable problem in these two kinds of methods, perplex industry development always.Whole circle low pressure casting is to utilize polylith withdrawing pattern gypsum mould to be spliced into the gypsum tire model; Fixedly the tire gypsum mould guarantees geometry and each piece position relative position then; The tire gypsum mould is filled die cavity as core pattern liquid aluminium under the effect of pressure be frozen into aluminium alloy tire-mold foundry goods; Carry out machined profile (die shape) size then, the place one's entire reliance upon precision of tire plaster cast of die cavity part (tire profile) can not be revised after the casting.Whole circle low pressure casting require gypsum mould piece together the circle specification requirement high, piece together circle difficulty relative positional accuracy big, each piece gypsum mould and cannot say for sure that so ovalizing deflection appears in card casting back pattern ring easily.Individual cast is to utilize terrestrial gravitation to fill with withdrawing pattern gypsum mould casting mold downwards by the liquid aluminium gravity flow to be frozen into aluminium alloy tire-mold foundry goods; Then every block of tire-mold foundry goods is carried out machined; With its polylith tire-mold die cavity part (tire profile) splicing, reach the physical dimension requirement of tire through process unit.So so its process defectives such as pore is mingled with occur easily because casting process carries out being mingled with gas easily in when cast liquid aluminium under natural environment; Its gravitational casting be again monolithic carry out cause the casting time longer; The chemical composition of the pattern block of casting and last piece pattern block can occur than large deviation at first; Each casting mold cooling condition also is difficult to be consistent, and this causes each pattern block interior tissue difference to occur, has influence on mould and die accuracy retention time and service life.

Summary of the invention

The object of the invention is exactly the problems referred to above that exist to prior art, in conjunction with the advantage separately of whole circle low pressure casting and two kinds of casting methods of piecemeal gravitational casting, proposes a kind of tire-mold low-pressure casting method of eliminating the pattern ring distortion.

Its technical scheme is: at first, each piecemeal plaster mold grows at circumferencial direction in advance during the design plaster mold, is non-standard toroidal plaster cast after its splicing, and navigates on the bottom die of casting mold cavity; Its two, the upper and lower upper and lower horizontal location groove that is processed with concentric respectively in the plaster cast neighboring; Its three, metal mold on the casting mold cavity is installed in the neighboring of plaster cast, plaster cast constitutes casting mold cavity as core pattern and upper and lower metal mold, liquid aluminium is frozen into aluminium alloy tire-mold foundry goods after filling casting mold cavity along the bottom die running channel; Its four, after the tire-mold foundry goods cooling, again the aluminium alloy tire-mold is cut into the pattern block foundry goods of monolithic; Its five, then every block of pattern block foundry goods is machined into standard standard pattern block through plane positioning benchmark (P) and cylinder positioning reference (C) location; Through process unit the standard pattern block is spliced into whole tire-mold at last.

The plaster mold of forming plaster cast is the 4-12 piece, and the pattern block foundry goods that the aluminium alloy tire-mold is cut is the 4-12 piece.

Current the most frequently used whole circle low pressure casting and two kinds of methods of gravity individual cast are merged in the present invention, have complementary advantages.The pattern block of its production has been inherited the characteristics that whole circle Casting Chemistry composition is identical and metallographic structure is consistent, and particularly thermal coefficient of expansion is identical for each pattern block mechanical performance, in use expansion gap can not occur.Improved common low pressure casting yield rate and reduced technology difficulty, the later stage is adopted the ripe mechanical processing technique of gravity individual cast, and the mold integral quality is greatly improved, and cost also obviously reduces.

Description of drawings

Accompanying drawing 1 is the casting installation diagram of an embodiment of the present invention;

Accompanying drawing 2 is the pattern block foundry goods sketch mapes after cutting;

Accompanying drawing 3 is outline drawings of the standard aluminum alloy tire grinding tool pattern block after the processing;

Accompanying drawing 4 is existing whole circle low pressure casting pattern ring distortion enlarged diagrams;

Accompanying drawing 5 is that the back whole circle low pressure casting pattern ring of cutting of Fig. 4 is out of shape enlarged diagram;

Accompanying drawing 6 is to the 1 tolerance compensating sketch map of pattern block among Fig. 4.

The specific embodiment

Do further statement below in conjunction with accompanying drawing:

Map 1, each piecemeal plaster mold at circumferencial direction longer (pattern block of similar Fig. 5), utilizes polylith withdrawing pattern plaster mold to be spliced into plum blossom lobe shape plaster cast 3, and navigates on the bottom die 2 of casting mold cavity structure in advance when at first designing plaster mold; Its two, the upper and lower upper and lower horizontal location groove that is processed with concentric respectively in plaster cast 3 neighborings; They are three years old; Metal mold on the casting mold cavity 1 is installed in the neighboring of plaster cast; Plaster cast constitutes casting mold cavity as core pattern and upper and lower metal mold, and liquid aluminium is frozen into aluminium alloy tire-mold foundry goods (mid portion is by plasterboard 4 shutoff) after filling casting mold cavity along bottom die running channel 5; They are four years old; After the cooling of tire-mold foundry goods; Through aluminium alloy pattern blocks of tire mold foundry goods 6 (see figure 2)s through sawing pattern ring piecemeal formation monolithic on sawing machine behind cleaning gypsum mould, the car rising head; Then every block of pattern blocks of tire mold foundry goods is carried out machining through plane positioning benchmark P and cylinder positioning reference C location, remove pattern blocks of tire mold foundry goods Central Plains plaster mold in advance in the long position of circumferencial direction; Through the existing processes device its polylith tire-mold die cavity part (tire profile) is spliced to the physical dimension requirement of tire at last, Vehicle Processing pattern block cylindrical guarantees pattern block inside and outside with one heart, be processed into aluminium alloy pattern blocks of tire mold 7 (see figure 3)s.Through process unit the standard pattern block is spliced into whole tire-mold at last.

In order more to clearly demonstrate technical scheme of the present invention and its technical characterstic, be described further below in conjunction with prior art and 4,5 and 6 pairs of principles of the present invention of accompanying drawing:

The pattern ring that common whole circle low-pressure casting method is produced such as Fig. 4 (among the figure for intuitively exaggerative consciously distortion), circularity is difficult to guarantee, almost all has ovalizing deflection, among the figure shown in " actual tire tip circle " curve.Maximum deformation quantity appears between C point and the D point, and the numerical value of CD is between 0.3mm to 1.5mm generally speaking.Distortion like this occurs, represent that this pattern ring is seriously overproof.Passenger tire has strict demand to tire top diameter dimension, and circle is beated (maximum radius and minimum the poor of radius, just the W value among Fig. 4 of allowing of allowing) must be less than 0.25mm.Sometimes be that oval effect is not obvious, but diameter integral is less than normal or bigger than normal.Can find out that from last figure pattern ring has become ellipse, the actual tire tip circle of 8 pattern blocks is all undesirable.Want to correct, must use special frock to stretch or push and offset distortion.This only is approximate shaping, does not have accuracy guarantee, also needs at last to repair remaining deflection by hand, and precision is not high.

We arrange these 8 pattern blocks once again now, let the tire tip circle of each pattern block all be placed on the ideal position, just let the tire tip circle all fall between maximum standard round and the minimum sandards circle, and are as shown in Figure 5.As can beappreciated from fig. 5, after pattern block moved to normal place, tire tip circle and standard round were identical basically, but

pattern block

1 and 5 and the standard round difference bigger.

Be that example is analyzed with pattern block 1 now, tolerance compensating sketch map as shown in Figure 6, the B point drops within the minimum sandards circle among Fig. 6 a, and the B point drops between two standard rounds among Fig. 6 b.Be example explanation with the 700mm diameter now, if maximum distortion appears in the tire tip circle, this moment, CD=1.5mm about the then corresponding about 0.221mm of AB value, can find out that B point fallen in minimum sandards justifies, and had exceeded tolerance.Be moved to the left pattern block 1 shown in Fig. 6 b now, A point and B point all can drop between the minimum and maximum standard round.In the actual production; Ovalizing deflection is mostly between 0.3 to 1.5mm; Corresponding AB value is between 0.044 to 0.221, and therefore this method can be eliminated the casting distortion fully, thus we when casting each piece pattern block in advance in grow some technology of circumferencial direction; Both can satisfy the requirement in footpath, tire tire top, be convenient to the machining needs in later stage again.

For later stage machining is carried out centering, also reserved positioning reference on the plaster cast.See that from die angle be exactly going up mo(u)ld bottom half has more positioning reference, as shown in Figure 2 is the pattern block foundry goods of cast with the present invention, compare with the pattern block of common piecemeal cast, more than the upper and lower mould two positioning references, be used for later stage machining.Benchmark P is used for levelling pattern block end face and bottom surface, and benchmark C is concentric with the tire tip circle, and main effect is to navigate to pattern block on the position that can satisfy tolerance, is example with pattern block 1, navigate to pattern block the position of Fig. 6 b, just must utilize benchmark C.

Claims

1. eliminate the tire-mold low-pressure casting method that pattern ring is out of shape for one kind; It is characterized in that: at first; Each piecemeal plaster mold grows at circumferencial direction in advance during the design plaster mold, is non-standard toroidal plaster cast after its splicing, and navigates on the bottom die of casting mold cavity; Its two, the upper and lower upper and lower horizontal location groove that is processed with concentric respectively in the plaster cast neighboring; Its three, metal mold on the casting mold cavity is installed in the neighboring of plaster cast, plaster cast constitutes casting mold cavity as core pattern and upper and lower metal mold, liquid aluminium is frozen into aluminium alloy tire-mold foundry goods after filling casting mold cavity along the bottom die running channel; Its four, after the tire-mold foundry goods cooling, again the aluminium alloy tire-mold is cut into the pattern block foundry goods of monolithic; Its five, then every block of pattern block foundry goods is machined into standard standard pattern block through plane positioning benchmark (P) and cylinder positioning reference (C) location; Through process unit the standard pattern block is spliced into whole tire-mold at last.

2. the tire-mold low-pressure casting method of elimination pattern ring distortion according to claim 1 is characterized in that: the plaster mold of forming plaster cast is the 4-12 piece, and the pattern block foundry goods that the aluminium alloy tire-mold is cut is the 4-12 piece.