CN101186107B

CN101186107B - Plastic piece shaping method

Info

Publication number: CN101186107B
Application number: CN2006101184756A
Authority: CN
Inventors: 朱旻; 柴琦佺; 侯剑锋; 王健
Original assignee: Yanfeng Visteon Automotive Trim Systems Co Ltd
Current assignee: Yanfeng Automotive Trim Systems Co Ltd
Priority date: 2006-11-17
Filing date: 2006-11-17
Publication date: 2011-10-26
Anticipated expiration: 2026-11-17
Also published as: CN101186107A

Abstract

The invention relates to a plastic part forming method, comprising the following steps that a slush-molding die is provided with a bent trough arris and a process arris; a distance L is arranged between the bent trough arris and the process arris; the cuticle of the plastic part made by the slush-molding die is provided with a cuticle bent trough and a cuticle process trough respectively corresponding to the bent trough arris and the process arris on the slush-molding die; the cuticle at one side of the cuticle process trough far away from the cuticle bent trough is torn; the foaming disposal is carried out to the residual cuticle; the residual cuticle is automatically bent when foaming. The edge of the cuticle of the original plastic part is added with a section of bent edge which is adopted for blocking escaped material. When foaming, the foam firstly impacts the bent trough and small amount of foams enter the second area; as the cuticle is bent, the cuticle is tightly jointed with the framework; furthermore, the escaped gas in advance jacks the cuticle on the internal surface of the framework and escapes to two sides along the second area.

Description

Plastic piece shaping method

Technical field

The present invention relates to a kind of plastic piece shaping method, specifically, is the plastic piece shaping method that is used for fascia and other inside gadgets.

Background technology

The development trend of current fascia and inside gadget, the functional diversities of structure and more the outward appearance of fashion more and more become the magic weapon that the developer captures the consumer, and in the fascia driver's eyesight the focus that becomes more attractive in appearance of common part.A kind of product that relates to the instrument board outward appearance is wherein disclosed among the European granted patent EP 0768160, shown in Fig. 1 (side sectional view), it provides a kind of light plastic with good appearance to become the mould product, comprise a core skeleton 91 and be arranged on the exocuticle that has foam 92 on this core outer surface part zone, can not produce the waste of the next skin material of the necessary epidermis technology of common technology sideband when the advantage of this product is to make exocuticle, and save simultaneously and removed the necessary cutting technique in epidermis technology limit.For instrument board technology, sometimes in order to hide remaining technology limit, cutting back, instrument board framework 91 has to be decomposed into upper body and two skeletons of lower body by being welded together, and therefore adopts this structure that the bigger free degree is arranged in the shape-designing of skeleton.Described plastic pattern with core is coating PUR foam 93 above, and foam 93 tops are coating epidermis 92, and in the edge of epidermis 92, core will have a V-type groove 94, and epidermis 92 is directly imbedded in the core groove 94, and is withstood when foaming by foam 93.

The forming method of this plastic pattern may further comprise the steps:

Be layered in the foaming mould lower mode cavity epidermis 92 and the location, skeleton 91 is positioned at mould top and is fixed, and when mould was closed, epidermis 92 was just accurately corresponding with core skeleton 91 positions; Cast foam 93 also makes it be full of gap between skeleton 91 and the epidermis 92 at foamed material, makes foam 93, skeleton 91 and epidermis 92 seamless integrating.

During the foamed material foaming, the pressure between skeleton 91 and the epidermis 92 is owing to the successive reaction of foamed material increases.Correspondingly, thus the foamed material that the sidewall of epidermis 92 is inflated is expressed on the skeleton 91 corresponding indent sidewalls and is forming sealing.Residual gas will be discharged along pre-set exhaust position 95 in the die cavity, and then foamed material flows to epidermis 92 edges and outside extruding skeleton 91 sidewalls simultaneously, finally cause the sidewall of epidermis 92 and the skeleton 91 can be by strong and firm sealing.

But still there are some shortcomings in above scheme, as shown in Figure 1, such as pressing the excessive outer surface that causes foamed material to spill into model in can't guaranteeing fully when foaming, causes the rising of percent defective.

In addition, the open 2001-353735 of Japan Patent also discloses similar products like and scheme, as shown in Figure 2, its improvements are that the crooked end at epidermis 81 has increased the projection 83 of several places away from the inner concave wall of skeleton 82, so just make when foamed material 84 foaming, even its excessive space of perhaps at first filling up projection 83 formation could be continued excessive, because along with the prolongation expanded material of time can harden gradually, thereby reduce overflowing of foam more, but still can't reach zero-fault in the actual production, and because this technology is last one moulding process of this product, there are not follow-up repairing means, in case occur that fluid is excessive will directly to cause scrapping of product to cause unnecessary waste.It proposes this scheme simultaneously also needs to drop into more energy and time in the processing of epidermis 81, because go out back the hook structure in little positional configuration like this, many materials can't satisfy its performance requirement.

Summary of the invention

The technical problem to be solved in the present invention is, a kind of forming method of plastic pattern is provided, and can both satisfy the foaming requirement, can overcome bad the escaping of causing of epidermis and reinforced seal again and expect to scrap.

In order to achieve the above object, technical scheme of the present invention is as follows:

A kind of plastic piece shaping method comprises the steps: to be provided with curved slot corner angle and technology corner angle on slush mold; Be provided with a segment distance L between curved slot corner angle and the technology corner angle; Epidermis with above-mentioned slush mold manufacturing working of plastics has epidermis curved slot and epidermis technology groove on the epidermis, respectively curved slot corner angle and the technology corner angle on the corresponding slush mold; Tear the epidermis of epidermis technology groove off away from epidermis curved slot one side; To processings of foaming of residue epidermis, residue epidermis bending automatically when foaming.

Described epidermis technology groove is than the crooked groove depth of epidermis.

Described distance L is 6～10mm.

The height of described curved slot corner angle is 1.5～1.8mm.

The width of the bottom of described curved slot corner angle is 2mm.

The height of described technology corner angle is 2～2.5mm.

The width of the bottom of described technology corner angle is 2mm.

Epidermis edge at original working of plastics increases by one section curved edges, utilizes this curved edges to escape to expect shutoff.At when foaming foam impact bending groove at first, have a spot of foam and enter second area, because epidermis bending, it is very tight that epidermis and skeleton are fitted, and the gas of escaping from advance can withstand on epidermis the skeleton inner surface, and escape to two side ends along second area, so second area itself also has good degassing function.Therefore foam enters and seldom has foam behind the second area and escape from this zone.Even there is fragmentary foam to enter the 3rd zone, also in the 3rd zone, digested, can be not excessive to epidermal surface.

Description of drawings

Fig. 1 is existing a kind of structural representation that becomes the molding materials and parts;

Fig. 2 is the structural representation of existing another kind of one-tenth molding materials and parts;

Fig. 3 is the structural representation of the one-tenth molding materials and parts of embodiments of the invention;

Fig. 4 is the structural representation of the made slush mold of plastic piece shaping method of the present invention;

Fig. 5 is the structural representation of the made epidermis of plastic piece shaping method of the present invention.

The specific embodiment

According to Fig. 1 to Fig. 5, provide preferred embodiment of the present invention, and described in detail below, enable to understand better function of the present invention, characteristics.

As shown in Figure 3, increase by one section 6～10mm curved edges, utilize this curved edges to escape to expect shutoff at the epidermis edge of original working of plastics.At when foaming foam 4 impact bending groove 14 at first, have a spot of foam and enter zone 12, because epidermis 1 bending, can make epidermis 1 and skeleton 2 fit very tight, and the gas of escaping from advance can withstand on epidermis 1 skeleton 2 inner surfaces, and escape to two side ends (be vertical paper direction in the diagram) along zone 12, therefore regional 12 itself also have good degassing function.Therefore seldom have foam after foam enters regional 12 and escape from this zone.Even there is fragmentary foam to enter zone 13, also in zone 13, digested, can be not excessive to epidermis 1 surface.

In order on epidermis, to make this effect, need do change to the epidermis mould.With common slush mold is example, as shown in Figure 4, two

cusped edges

31,32 should be arranged on the slush mold after the change, one of them is curved slot corner angle 31, another is technology corner angle 32, distance between the end 311 of curved slot corner angle 31 and the end 321 of technology corner angle 32 is 6～10mm, this distance and cuticular border development length correspondence.Curved slot corner angle 31 are to be generation epidermis curved slot 14 as shown in Figure 5, the width of these curved slot corner angle 31, and promptly the distance between the both ends 311,312 is 2mm.The height of curved slot corner angle 31, promptly end 313 is 1.5～1.8mm to the distance between 311,312 lines of both ends.Whole curved slot corner angle 31 can make triangle or point is circular-arc, so that produce epidermis curved slot 14 shown in Figure 5.Technology corner angle 32 are to be generation epidermis technology groove 15 as shown in Figure 5, the width of these technology corner angle 32, and promptly the distance between the both ends 321,322 is 2mm; The height of technology corner angle 32, promptly end 323 is 2～2.5mm to the distance between 321,322 lines of both ends; Main purpose is in order after the slush moulding shaping unnecessary technology cuticular border to be removed along groove is manual.The setting of concrete size should be determined according to skeleton or core counter structure, guarantees that epidermis has enough crooked radians, but also unsuitable long, otherwise wrinkling easily during the epidermis foaming.Herein epidermal thickness will be weakened during the epidermis moulding.Technology groove should be darker, directly removes with hand when being convenient to produce, and curved slot should be more shallow, and purpose is in order to make the epidermis bending, and can not be torn easily.

The epidermis that roto casting is produced as shown in Figure 5, the epidermis 16 usefulness hands outside the right side epidermis technology groove 15 directly tear off because epidermis technology groove 15 places are very thin, this epidermis 16 is easy to remove.Epidermis after removing as shown in Figure 3, therefore the curved slot in left side 14 is not easy to be torn because residual thickness is thicker.Automatically crooked when foaming,

form zone

12,13.

Contrast traditional HPI (High Performance Injection) foaming technique, the present invention can significantly reduce the probability that the HPI limit escapes to expect, adopt the product of traditional envelope material technology nearly 1/3 to escape material, can remedy part through follow-up repairing and escape to expect defective, but more serious still can only scrapping.The present invention can accomplish substantially that the HPI limit does not have and escape material, has improved the qualification rate of HPI foaming greatly, has alleviated the labour intensity of follow-up repairing, and has improved productive temp.

The front provides the description of HPI foaming inhibition being escaped to expect implementation method, so that any technical staff in this area can use or utilize the present invention.Fig. 3 is the typical case that this method of a usefulness is implemented.This method implementation result is conspicuous to those skilled in the art, can be applied to total principle described here in other enforcements.Thereby, the embodiment shown in the present invention will be not limited to here, and the wide region of principle that should disclose and new feature according to meeting here.

Claims

1. a plastic piece shaping method comprises the steps:

Curved slot corner angle and technology corner angle are set on slush mold;

Be provided with a segment distance L between curved slot corner angle and the technology corner angle;

Epidermis with above-mentioned slush mold manufacturing working of plastics has epidermis curved slot and epidermis technology groove on the epidermis, respectively curved slot corner angle and the technology corner angle on the corresponding slush mold;

Tear the epidermis of epidermis technology groove off away from epidermis curved slot one side;

Carrying out the HPI foaming makes the residue epidermis crooked automatically.

2. plastic piece shaping method as claimed in claim 1 is characterized in that, described epidermis technology groove is than the crooked groove depth of epidermis.

3. plastic piece shaping method as claimed in claim 2 is characterized in that, described distance L is 6～10mm.

4. plastic piece shaping method as claimed in claim 3 is characterized in that, the height of described curved slot corner angle is 1.5～1.8mm.

5. plastic piece shaping method as claimed in claim 4 is characterized in that, the width of the bottom of described curved slot corner angle is 2mm.

6. plastic piece shaping method as claimed in claim 5 is characterized in that, the height of described technology corner angle is 2～2.5mm.

7. plastic piece shaping method as claimed in claim 6 is characterized in that, the width of the bottom of described technology corner angle is 2mm.