DE2108289A1 - Sprue device for the shaping processing of plastics formed from several liquid components, in particular of cell-forming plastics - Google Patents

Description

ANKERWERK NÜRNBERG GMBH, S5 NUREMBERG, RENNWEG 37

Sprue device for the shaping processing of Plastics that are formed from several liquid components, in particular of cell-forming plastics

The present invention relates to a sprue device for the shaping of a plurality of liquids Components of forming plastics, in particular of cell-forming Plastics, with an attached to the relevant shape bush-like guide body and a piston mounted in this guide body so as to be rotatable and longitudinally displaceable, wherein dEach liquid components via the guide body / piston combination get into the respective mold cavity.

They are already used for processing liquid plastics Devices similar to finished articles have become known in various embodiments. According to one embodiment, the injection of the mixed liquid components is carried out into the mold with an injection tube, which is arranged above the liquid level forming in the mold cavity, accomplished, whereby a closing of the gate opening of the injection tube by hand or at the injection process by means of automatic acting devices by means of a stopper connects.

According to a further proposal, the injection takes place mixed liquid components into the mold using

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a 3-way valve attached to the mold, which when finished of the injection precedent manually or automatically is brought into the closed position. This system allows injection both above and below the liquid mirror.

By means of another known device, in the first place Line can be achieved that the leading to the mold cavity Channel for the injection of the liquid material during the plastic article production of plastic residues is kept free. For this purpose, a bush-like guide body is attached to the mold, in which a piston is rotatable and longitudinally displaceable is stored. The * piston has a longitudinal notch (injection channel) which faces the mold cavity Front side does not break through. The liquid plastic gets through the side wall of the piston into the mold cavity, namely through one or more orifices running at an angle to the longitudinal axis of the piston or the bore. With the side Arrangement of one or more mouths, by choosing the size of these mouths and by turning the piston the aim is to ensure that the plastic is injected in the preferred direction within the mold cavity can. The injection process can, however, only be triggered when the piston having the orifices is open enough protrudes into the mold cavity. Keeping or cleaning the mouths and injection port, however, is only possible if

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when the.KoIben takes its "rearward position and the Supply line for the cleaning agent with the mouths and thus is in communication with the injection port.

A mixing chamber to be attached to molds has also become known, in which the respective Components are mixed together. The components circulate before the start of each mold filling negative pressure. This means that the components reach the mixing chamber via separate lines and from there are transferred to the respective one Tank returned. The injection process is triggered by the fact that only the opposing nozzle openings released at the same time.

The presentation of these known devices alone should have shown that the previous proposals are afflicted with various shortcomings. In the case of the first-mentioned arrangement with the injection tube, it is disadvantageously noticeable that the injection tube has to be laboriously closed after each filling process. This Vei'schließen is to be cleaned while in terms of time an obstacle to the subsequent cleaning process by which at least a portion of the injection pipe by means of compressed air and / or rinsing liquid ^1. Since a special mixing device must also be connected upstream of the injection tube, a cleaning process is also necessary with regard to the mixing unit. Mold partiBic disadvantages also result from the fact that with the arrangement of the injection tube above the liquid forming in the mold cavity

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there are certain restrictions regarding the design are to be accepted. In addition, the liquid materials enter the mold as a free jet via the injection tube, whereby in most cases there is a risk of turbulence. Air inclusions are the result, which then lead to lead to faulty areas in the finished part. And finally it should be pointed out that in many cases there is an injection tube Cure sprues that have to be removed with additional rework.

The arrangement in which the 3-way valve is used, has essentially the same disadvantages. In addition, however, there is the fact that for the flushing or rewinding process the 3-way valve must be switched so that the connection to the mold cavity is closed and at the same time a free one Connection between atmosphere and mixed canoe is established.

^ In connection with the third of the known arrangements problems of the same kind arise by and large. It is true that closing the injection channel is not considered cumbersome but it is also a costly, time-consuming cleaning process in the mouth area necessary. A mixing device and the liquid materials must also be connected upstream of the injection channel enter the mold as a free jet. When the mold has been filled, the respective mouth of the piston is still there for the purpose of cleaning exactly in the plane of an annular space

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and finally, an orifice can only be enlarged or reduced by changing the piston will.

With the still known mixing chamber in which after the Principle of high pressure countercurrent injection 'is worked, Although the mixing process can be placed in the area of the mold cavity, this arrangement is also different Associated disadvantages. Because the jet exit cross-sections in the mixing chamber are determined by the nozzle diameter used therefore, certain stocks of different nozzles must be available for several throughput quantities of liquids be. In addition to this disadvantage of storage, there is also the fact that the liquid materials are also used here as free jets get into the mold cavity, which increases the risk of turbulence and thus the inclusion of Air is given. Since the components circulate under pressure before and after the mold filling process, there is also increased Energy consumption also recorded a constant leakage loss. In addition, it occurs in similar devices due to the difference in viscosity of the individual components (ratio up to about 1:10) a pre- or post-run of one or more of the Components, whereby the quality of the molded part is affected. Knowing this In fact, attempts are still being made to eliminate the pre-run and post-run by additional units such as accumulators and throttles.

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The invention is based on the object of a sprue device for the shaping processing of several to create liquid components forming plastics, with which the aforementioned disadvantages are eliminated and With which an economical, universal use is guaranteed, especially with a simple, clear structure can.

This object is achieved in that the sleeve-like guide body is arranged displaceably in the wall of the respective mold that the supply lines for the liquid components are housed in the sleeve-like guide body and via nozzle-like bores in a trained in the bush-like guide body mixing or. Sprue area open and that in the mixing or sprue area Piston is mounted so movably independently of the displacement drive of the sleeve-like guide body that the Mischbzw. Sprue space can be completely or partially filled and, depending on the position of the piston, a closure or a complete or partial one Opening one or more of the nozzle-like holes is feasible. According to a special feature in this context is "provided that the creation of a Sprue ring gap in the mold cavity of the bush-like guide body with its end face in the immediate vicinity the opposite boundary surface can be brought .. Um to transfer the required movements to the piston

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can, according to the invention, on the one hand, the housing of the All-drive means for the piston movements with the bush-like guide body rigidly, but detachably connected while on the other hand, the driving part of the drive means with the Piston is brought into rigid, but releasable connection. The drive means for the movements can be advantageous of the piston consist of a pressure-medium operated piston-cylinder unit. To the same way on the socket-like To be able to transmit the necessary movements to guide body, according to the invention, on the one hand, the housing of the drive means becomes for the guide body movements rigidly but detachably connected to the form, while on the other hand the driving Part of the drive means with the housing of the drive means responsible for the movements of the piston in rigid, but detachable connection is brought. Here, too, the drive means for the movements of the Bush-like guide body consist of a pressure-medium operated piston-cylinder unit. An additional feature is to see that the movements of the piston and / or the movements of the sleeve-like guide body by stops be limited.

In a further embodiment of the invention it is provided that the nozzle-like bores in the sleeve-like guide body are arranged opposite one another and that the axes of the holes lie in one plane. In this context

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it is also thought that the exit cross-sections of the nozzle-like holes even during a Foriufüllvorganges can be changed. And finally the piston can be rotatably mounted and its front side as an inclined surface be trained while at the same time. or independently the circumferential surface of the piston for the purpose of discharging leakage fluid Has foul grooves. All or some of these catch grooves can form closed drainage circles, it is also provided that the catching grooves and / or the Abführkx'eise via channels of the bush-like guide body can be brought into connection with the free atmosphere.

When using the device according to the invention, there are a whole range of advantages, some of which are surprising. So, first of all, there is no separate one apart from the sprue device itself Mixing or feeding head necessary. The invention also avoids using the full cross section of a nozzle bore to have to bring special arrangements into the mold cavity. There can also be time delays caused by the flushing or the cleaning process occur, are switched off, as well as the use of cleaning agents during the course of the process comes in omission. At the same time, any possible impairment of the components through cleaning agent residues is avoided avoided. The invention also makes it possible to optimally close the mold cavity, and between that of the Form facing part of the sprue device. There is also no uneven exit energy box variation of the

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record more and also include the use and the storage of different nozzles is a thing of the past. This is also avoided with considerable energy consumption connected constant circulation of the components under pressure and it also succeeds in the pre- and post-carriage effectively turn off. Furthermore, a particular advantage can be seen in the creation of an optimal inflow option, since the Free jet and thus air inclusions that result in uncontrollable turbulence are eliminated. In the same way It is advantageous that the formation of sprue bars no longer has to be taken into account, because it can not only do this Material, but also corresponding rework on the molded parts can be saved. And finally, it should be special are in the interest of processing companies if the sprue device according to the invention is not only in connection with a special shape can be used.

See the schematic shown in the drawings Exemplary embodiments are intended to explain the invention in more detail will. Show it:

Fig. 1 is a plan view of the sprue device according to the invention, parts thereof and the indicated shape are shown in section,

FIG. 2 shows a detail from FIG. 1 in an enlarged illustration, partly also in section, and

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Fig. 3 shows a detail from Fig. 2, but according to a different one Embodiment.

According to Fig. 1, the socket-like guide body 1 is in the Wall of the existing in this embodiment of the two mold halves 2 and 3 mold arranged displaceably. • In the position shown, the end face 4 of the bushing-like guide body 1 runs flush with the inner wall of the mold cavity 5 and is thus shaping. So that the bush-like guide body 1 can be shifted within the shape 2, 3, so that it is steplessly or stepwise can be introduced into the foam cavity 5 to an unlimited extent, the housing or the cylinder 6 of the drive means for the movements of the sleeve-like guide body 1 with the Form 2.3 rigidly but detachably connected via support bodies or support bars 7 and 8. In the cylinder 6 is a bilateral with Piston 9 which can be acted upon by pressure is mounted vex'schiebbar, the has a piston rod 10 penetrating the two end faces of the cylinder 6. While that of the shape 2,3 averted The end of the piston rod 10 has a thread 11, onto which lock nuts 12 can be screwed, that of the shape 2, 3 The facing end of the piston rod 10 is brought into a rigid, but releasable connection with the housing or the cylinder 13. As can be seen in particular from FIG. 2, is also in the cylinder a piston 14 which can be pressurized on both sides can be displaced stored, the piston rod 15 penetrates the face facing the mold 2, 3 and with the piston 16, which is in the mixing b ^ w.

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Sprue space 17 of the bush-like ig-en guide body 1 is displaceable is arranged, is in a cohesive connection. Above Support members IS and 19 is the piston-cylinder unit 13,14,15 with the bush-like guide body 1 rigid., but detachable tied together.

The displacement movements of the piston 16 within the Mischbzw. Sprue space 17 is created by the fact that the cylinder 13 located piston 14 either over the opening 20 or is acted upon via the opening 21 with a pressure medium. That further provided according to the invention is unlimited Introducing the bush-like guide body 1 into the foam cavity 5 is effected in that a pressure medium is pressed into the cylinder 6 via the opening 23. Should the socket-like Guide body 1 are withdrawn again from the mold cavity 5, then-the piston 9 via the other opening 22 pressurized. It is clear that these movements of the sleeve-like guide body 1 and of the piston-cylinder unit 13, 14, 15 are carried out together, the independence of the drive for the piston 16 being guaranteed, of course remain. The stepless or, if necessary, also stepwise Movements of the bushing guide body 1 or the piston 16 can be limited by stops 12 or 24 and 25.

For the introduction of the liquid components into the mixing or sprue space 17, there are feed lines in the bushing-like guide body 1 26 and 27 housed, which via nozzle-like Bohruntfon 28 and 29 in the mixed or sprue rnua? 3 7 open. The düson-Ιίί ',' ΊΊ T'Jobrun ^ tiji 2o and 29 wordon riabi-i vorzui'swoiKP .so; uj ;; e-

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arranges that they are opposite each other and that their axes are in one plane. Thus, for the purpose of changing the exit cross-sections in the nozzle-like bores 28 and 29, steplessly adjustable cone column can be formed are in the bores 28 and 29 actuators 30 and'31 voi-seen, the run out at their end facing the mixing or sprue space 17 in a cone or truncated cone. The change in situation the actuators 30 and 31 can mechanically for the respective work phase with the aid of known devices, be effected hydraulically, pneumatically or electrically.

So that in the mold cavity 5 no leakage or none Material residues can get through and therefore no impairment of the piston movements is to be feared the piston 16 has catch grooves for the purpose of discharging leakage fluid. The catch grooves of the circumference and / or the Follow the axis line of the piston 16. In this context, it is also useful if all or some of the gripping grooves Form closed discharge circuits 34 and 35. Furthermore, each component can have one or more fan groove discharge circuits be assigned. With reference to Fig. 2. this means that the component emerging from the bore 28 the discharge circuit 34 is assigned, while on the other side the bore 29 and the discharge circuit 35 to a certain extent form a unit. It has also proven to be advantageous to use individual grooves to separate the individual discharge circles 34, 35

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to separate from each other. Despite everything, leakage amounts · two x * eaktionsf ähigex · components in the separating grooves 36, so would have these in it and also form a natural, secure seal. The same advantages also arise with regard to on the circumferential grooves 32 and 33. Finally, TJm also includes leakage fluids Abfühx'en are in the socket-like Guide body 1 channels 37 and 38 incorporated, which circles with the 'catching grooves 32,33,36 and / or the catching groove Abfühi-34,35 can be brought into connection.

According to the embodiment of FIG. 3 "is a piston 16 'mounted pers 1 movable, whose end face is formed according to the invention 39 as an inclined surface. The ^r through the supply lines 26 and 27' in the mixing or AngußraLim 17 of the sleeve-like Führungsköi or via the As already indicated, components that reach nozzle-like bores 28 'and 29' in the mixing or pouring space 17 generally do not have the same viscosity. It is therefore necessary to be able to create not only the same but also different beam outlet cross-sections in the nozzle-like bores 28 'and 29' lying opposite one another. This happens according to the present example, without having to arrange actuators in the nozzle-like bores 28 'and 29', in that the piston 16 'has its inclined end face 39 brought into the plane of the jet outlet quor.sohnitLo the desired location rotated wix-d. The rotation is done by means of known and therefore not sewing.'r dart; · «? .st eil tu ν devices either mechanically,

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hydraulic, pneumatic or electric. Of course, the piston 16 can also have catching grooves 32 *, 36 and / or catching groove discharge circles 34 ^r , 35.

For the required stoichiometric metering of the components Before the mixing process, a defined dosage in the known form of suitable pumps (piston pumps, gear pumps, etc.) carried out. The pumps mentioned are connected to the mixing or sprue chamber 17 via the supply lines 26, 27, 26 or 27 and connected via corresponding hoses.

The functional sequence for a working cycle is as follows: It is assumed that the metering pumps begin to deliver and the pressure set on a pressure valve in the line system via the supply lines 26, 27 or 26 ¹ , 27 ^r into the nozzle-like bores 28, 29 or 28, 29 'build up. At this point in time, the nozzle-like bores are still closed by the piston 16, 16. At the same time, the sprue device is moved from the rest position into the injection position, that is, the bush-like guide body 1, together with the piston-cylinder unit 13, 14, 15, assumes a position indicated by the dash-dotted line 40, as shown in FIG. There is thus a gap between the end face 4 of the bush-like guide body and the opposing boundary surface of the Formhohl.raunen 5, the width of which can be changed as required. This is achieved in that the piston 9 (Fig. 1) is acted upon with pressure via the opening 23, whereby the Ko'hen-

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rod ΙΟ, the piston-cylinder unit 13,14,15, the support members 18,19 and the bush-like guide body 1 in the Form 2.3 can be moved into the position described. The path that is to be covered here by the guide body 1 can go through mechanical stops 12 limited v / ground.

As soon as the mentioned functions are fulfilled, a pressure medium is introduced into the cylinder 13 via the opening 20, whereby the piston 16, 16 'moves backwards and thus into its injection position (limited by the adjustable stop 25). The nozzle-like bores 28, 29 and 28 ¹ , 29 * are thereby completely or partially open (see, for example, FIG. 3). The mixing and injection process begins automatically, the duration of which can be limited by a timer. The mixing process takes place in the mixing or sprue space 17, while the eddy-free introduction of the component mixture into the mold cavity 5 according to the invention can be ensured in that the flow occurring immediately at the sprue is immediately applied to the opposite boundary surface of the mold cavity 5. This advantageous forced guidance of the inflowing component mixture is brought about by the narrow annular outflow gap which is created between the mold cavity delimiting surface and the end face 4 of the bush-like guide body 1.

After the injection time has elapsed, the piston 16, 16 ^{r is brought} back into the position shown in FIG

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nozzle-like bores 28,29 or 28 ^! , 29 'are immediately vex-closed. This is achieved by applying pressure medium to the piston 14 via the opening 21. At the same time, however, the piston 9 is also pressurized via the opening 22, so that the starting position according to FIG. 1 is reached again within a very short period of time. As can also be seen from FIG. 1, the end face of the sleeve-like guide body 1 closed by the piston 16 runs flush with the inner wall of the mold cavity 5 and is thus shaping. This means that the formation of sprue bars can be avoided in an astonishingly simple manner and corresponding caching can be dispensed with.

When the finished molded part is removed from the mold after the end of the dwell time, a new work cycle can begin Start.

The metering pumps cooperating with the described device according to the invention are advantageously activated early after the nozzle-like bores 28, 29 and 28 ¹ , 29 ^! switched off by the piston 16, 16 'to generate energy for. to save the pump actuator. As long as the metering pumps are still working with the bores 28, 29 or 28 ', 29 ¹ closed, the liquid components can be returned to the tank in a known manner via pressure relief valves located in the line system.

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Claims (17)

- 1Ί - claims 1. / Sprue device for the continuous processing of plastics formed from several liquid components, in particular of cell-forming plastics, with a bush-like guide body attached to the mold in question and a piston mounted in this guide body so that it can rotate and move longitudinally, the liquid components via the combination Guide body / piston get into the respective mold cavity, characterized in that the bush-like guide body (1) is arranged displaceably in the wall of the respective mold (2, 3), that the supply lines (26, 27, 26 ¹ , 27 ^F ) for the liquid components are housed in the socket-like Fülirungskörper (1) and open via nozzle-like bores (28, 29, 28 ', 29') in a formed in the socket-like guide body mixing or sprue space (17) and that in the mixing or. Sprue area (17) a piston (16, 16 ^? ) Is mounted so that it can be moved independently of the displacement drive of the bush-like guide body (1) so that the mixing or sprue area (17) can be completely or partially filled and, depending on the position of the piston (16 , 16 ^F ) a closure or a complete or partial opening of one or more of the nozzle-like bores (28, 29, 28 ', 29 ^f ) can be carried out. -18- f- 209836/0996. ^ß * D OR / q _{/ nal} 3 G - 2. VoiTxchtung according to claim 1, characterized in that to create an annular gate gap in the mold cavity (5) of the bush-like guide body (1) with its end face (4) can be brought into the immediate vicinity of the opposite boundary surface. '3. Device according to one or both of the preceding claims, characterized in that on the one hand the housing of the drive means for the movements of the piston (16, 16 ') is rigidly but detachably connected to the bush-like guide body (1), while on the other hand the driving part of the drive means with the piston (16, 16 ¹ ) is brought into rigid, but releasable connection. 4. Device according to one or more of the preceding claims 1 to 3, characterized in that the drive means for the movements of the piston (16, 16 ') consists of a pressure medium-operated piston-cylinder unit (13, 14, 15) consists. 5. Device according to one or more of the preceding claims 1 to 4, characterized in that on the one hand the housing of the drive means for the movements of the bush-like guide body (1) with the mold (2, 3) is rigidly but detachably connected, while on the other hand the The driving part of the drive means is brought into a rigid but detachable connection with the housing (13) of the drive means responsible for the movements of the piston (.16, 16 ^f). -10- 2 0 9 8 3 6/0996 _ 19 - 6. Device according to one or more of the preceding claims 1 to 5, characterized in that the drive means for the movements of the bush-like guide body (1) consists of a pressure medium-operated piston-cylinder unit (6, 9, 10). 7. Device according to one or more of the preceding claims 1 to 6, characterized in that the movements of the piston (16, 16 *) and / or the movements of the socket-like Guide body (1) are limited by stops (12, 24, 25). 8. Device according to one or more of the preceding claims 1 to 7, characterized in that the nozzle-like bores (28, 29, 28 ^f , 29 ¹ ) in the bush-like guide body (1) are arranged opposite one another and that the axes of the bores ( 28, 29, 28 ^T , 29 ¹ ) lie in one plane. 9. Device according to one or more of the preceding claims 1 to 8, characterized in that for the purpose of changing the outlet cross-sections of the nozzle-like bores (28, 29, 28 ^!, 29 ^l ) are formed in these continuously adjustable cone gaps. 10. Device according to one or more of the preceding claims 1 to 8, in particular according to claim 9, characterized in that the setting of the cone gaps by actuators (3O, 33) takes place at their mixing or sprue -20- 209836/0996 ^ß AD ORIGINAL space (17) facing end in a cone or truncated cone run out and their position changes are effected mechanically, hydraulically, pneumatically or electrically. 11. The device according to one or more of the preceding claims 1 to 9, characterized in that the piston (16 ^f ) is rotatably mounted and the end face (39 ) of the "piston (16 ') is designed as an inclined surface. 12. Device according to one or more of the preceding claims 1 to 11, characterized in that dex 'piston (16, 16 ') for the purpose of discharging leakage fluid, catch grooves having. 13. Device according to one or more of the preceding claims 1 to 11, in particular according to claim 12, characterized in that the catch grooves of the circumference line and / or follow the axis line of the piston (16, 16 '). 14. Device according to one or more of the preceding claims 1 to 11, in particular according to claims 12 and 13, characterized in that all odex · some of the catch grooves Form closed discharge circuits (34, 35, 34 ', 35') for the leakage fluid. -21-. 209836/0996 15. Device according to one or more of the preceding claims 1 to 11, in particular according to claims 12 to 14, characterized in that one or more catching groove discharge circles (34, 35, 34 ', 35') are assigned to each component are. 16. Device according to one or more of the preceding claims 1 to 11, in particular according to claims 12 to 15, characterized in that the catching groove discharge circles (34, 35, 34 ', 35') are separated from one another ^{by individual grooves (36, 36 1).} 17. Device according to one or more of the preceding claims 1 to 11, in particular according to Claims 12 to 16, characterized in that the catch grooves (32, 33, 32 ', 33', 36, 36 ') and / or the catch groove filling circles (34, 35, 34', 35 ') can be brought into connection with the free atmosphere via channels (37, 38) of the bush-like guide body (1). Considered publication: German utility model 6 92 9 596 209836/0996 Blank page