A kind of gas auxiliary forming device
Technical field
The present invention relates to mould applications, be specifically related to a kind of gas auxiliary forming device.
Background technology
Along with expanding economy, people are more and more higher to the requirement of shape of product and presentation quality.The product very thick for product wall thickness, appearance requirement is very high, be to guarantee product surface outward appearance and product strength, air-auxiliary injection forming (GAIM) technological break-through the restriction of conventional injection molding, can be applied to neatly the moulding of various products.Gas assisted injection molding technology refers to injects melt by Compressed Gas, and first solidify melt and mold wall contact position, and continue to flow forward along a line of least resistance in melt flows forward position under the driving of gases at high pressure simultaneously, until be full of whole die cavity.Goods are cooling in the situation that keeping gas pressure, in cooling procedure, gas is exerted pressure from inside to outside, guarantee that article outer surface is close to mold wall, and penetrate by gas secondary, from inside, supplement the volume contraction of bringing because of melt solidifying, after goods cooled and solidified, get rid of again gases at high pressure, die sinking, completes a molding cycle.
But for the production of the larger media lines of diameter, still there is larger Residual Wall Thickness in GAIM technique, be accompanied by larger remaining wall thickness, also can exist melt because of the danger that Action of Gravity Field flows downward along die wall, make this technology have limitation.Although in recent years newly occur that water shaping technology can partly solve this technology problem, it is complicated that the auxiliary technique of the relative gas of water assist mold moulding process is wanted.Equipment manufacturing cost is higher, it is the auxiliary 3 times of prices of gas that a water additionally arranges standby, the auxiliary development starting of water is simultaneously more late, the stability of water shaping technique and the qualification rate of goods, also need further to optimize and improve, in the process of water shaping, along with the different moulding material of product, have layer phenomenon of wearing in various degree, this device is between these two kinds of technologies, in conjunction with the shaping characteristic of two kinds of techniques.
The links such as key technology major control gas injection, exhaust and the air pressure control of the auxiliary injection mo(u)lding of gas.Gas injection pressure is controlled the uniformity that will affect product wall thickness not in place.Particularly gas in long straight air flue penetrate evenly and steadily, moulding hollow rate is larger.But near gas inlet, easily produce erratic fluctuations.In variable cross-section and L shaped air flue, gas penetrate easy generation finger-type effect.Exhaust does not have a great impact the quality of goods smoothly.This is the technical problem that we generally face solution.
Summary of the invention
The invention provides a kind of gas auxiliary forming device, can solve the drawback that the melt that exists in the pipe production that diameter is larger flows downward along die wall because of Action of Gravity Field, simultaneously simple in structure, low cost.
In order to solve the problems of the technologies described above, the present invention is achieved by following technical proposals: a kind of gas auxiliary forming device, comprise air tube main body, it is characterized in that, also comprise the parts that move ahead of being located at described air tube main body one end and mating with this end face, in described air tube main body, be provided with the air flue that air feed stream passes through, one end of described air flue passes an end of described air tube main body, and be connected with air intake duct by valve, the other end of described air flue passes the end that described air tube main body is provided with the parts that move ahead.During work, front and back mould matched moulds, throat-fed, after injection moulding is full, stop injection moulding, the parts that now move ahead stretch into goods inside, valve open, gas is filled into goods inside by air flue under air pressure, at the pressurize product parts that promote to move ahead simultaneously, advances, and the inner unnecessary material of goods flows out goods by flash groove simultaneously.The parts that move ahead are moved forward by air pressure to make the wall thickness of goods even, and the phenomenon that does not exist not solidified melt to flow downward along die wall because of Action of Gravity Field.
As preferably, in described air tube main body, be also provided with the second air flue, described the second air flue runs through end and the air drain that described air tube main body is provided with the parts that move ahead, and described air drain is for losing heart.After goods complete, can be inside and outside pressure balanced by losing heart, facilitate die sinking.
As preferably, described valve is ball valve, and described ball valve offsets with the elastic component that is placed in described air flue.Ball-valve structure is simple, durable, good airproof performance.
As preferably, described elastic component is spring.
As preferably, described air tube main body is fixed in base, and described base comprises the first base and the second base, and described air tube main body is stuck in the first base and the second base by the step-like projection on it.Described air tube main body is fixed, be conducive to the stability in die manufacture.
As preferably, described air tube main body and described the first base contact-making surface are provided with the first sealing ring, and described air tube main body and described the second base contact-making surface are provided with the second sealing ring, and described the first base and the second base contact-making surface are provided with the 3rd sealing ring.These sealing rings have guaranteed the air-tightness of device, can when at logical gases at high pressure, not find gas leakage, install simple simultaneously.
Compared with prior art, the present invention has following beneficial effect: the present invention has avoided the phenomenon that in gas assisted injection molding technology, not solidified melt flows downward along die wall because of Action of Gravity Field, guarantee the even of wall thickness, reduced percent defective, saved cost.
The present invention is simple in structure, and cost is low, easy to operate.
Accompanying drawing explanation
Fig. 1 is cutaway view of the present invention.
Fig. 2 is the end view drawing contacting with the parts that move ahead of air tube main body in the present invention.
The specific embodiment
Below in conjunction with accompanying drawing and the specific embodiment, the present invention is described in further detail: a kind of gas auxiliary forming device, comprise air tube main body 3, the parts 5 that move ahead of being located at described air tube main body 3 one end and mating with this end face, in described air tube main body 3, be provided with the air flue 31 that air feed stream passes through, one end of described air flue 31 passes an end of described air tube main body 3, and be connected with air intake duct 7 by valve, the other end of described air flue 31 passes the end that described air tube main body 3 is provided with the parts 5 that move ahead.In described air tube main body 3, be also provided with the second air flue 11, described the second air flue 11 runs through end and the air drain 9 that described air tube main body 3 is provided with the parts 5 that move ahead, and described air drain 9 is for losing heart.In present embodiment, described valve is ball valve 1, and described ball valve 1 offsets with the elastic component that is placed in described air flue 31.In present embodiment, described elastic component is spring 2.Described air tube main body 3 is fixed in base, and described base comprises the first base 12 and the second base 13, and described air tube main body 3 is stuck in the first base 12 and the second base 13 by the step-like projection 14 on it.Described air tube main body 3 is provided with the first sealing ring 8 with described the first base 12 contact-making surfaces, and described air tube main body 3 is provided with the second sealing ring 4 with described the second base 13 contact-making surfaces, and described the first base 12 and the second base 13 contact-making surfaces are provided with the 3rd sealing ring 10.
During work, air tube main body 3 is arranged in base, guarantees the sealing of sealing ring, front and back mould matched moulds, throat-fed, after injection moulding is full, stops injection moulding, the parts 5 that now move ahead stretch into goods 6 inside, logical gases at high pressure from air intake duct 7, ball valve 1 is opened, and gas is filled into goods 6 inside by air flue 31 under air pressure, at the pressurize product parts 5 that promote to move ahead simultaneously, advance, the inner unnecessary material of goods 6 flow out goods 6 by flash groove simultaneously.The parts 5 that move ahead are moved forward by air pressure to make the wall thickness of goods 6 even, and the phenomenon that does not exist not solidified melt to flow downward along die wall because of Action of Gravity Field.After the complete pushing out product 6 of current line parts 5, stop injecting gas, in product, gas flows out goods 6 by the second air flue 11 and air drain 9, rear mold is opened, line position oil cylinder return, pushing-off product, ejecting mechanism return, put the parts 5 that move ahead, again injection moulding whole system is simple for structure, reliable, and repair and replacement are convenient, and cost is low, efficiency of assembling is high, highly versatile.