Method and mould for producing plastic containers, in particular fuel containers, by internal pressure forming
阅读说明:本技术 用于通过内部压力成形制造塑料容器尤其燃料容器的方法和模具 (Method and mould for producing plastic containers, in particular fuel containers, by internal pressure forming ) 是由 R·贝尔林 C·米恩特克维茨 于 2019-03-12 设计创作,主要内容包括:本发明涉及一种用于通过内部压力成形制造塑料容器的方法,包括步骤:-在构造带有模具空腔的成形模具(100)的模具件(110、120)之间布置软管状的预成形件;-闭合成形模具(100)并通过内部压力由预成形件成形或预成形容器,其中预成形件的环绕区段通过模具间隙被压入围绕模具空腔的腔室中并在该腔室中相对于带有固定的内部的保持夹爪(141)和可移动的外部的撕下夹爪(142)的夹爪对被挤压;-侧向推移外部的撕下夹爪(142),从而在外部的撕下夹爪(142)和内部的保持夹爪(141)之间的环绕区段被撕开,并且该容器被分成两个容器半体(230、240)。本发明还涉及一种适合用于执行该方法的成形模具(100)。(The invention relates to a method for producing plastic containers by internal pressure forming, comprising the steps of: -arranging a hose-like preform between mould parts (110, 120) of a forming mould (100) configured with a mould cavity; -closing the forming die (100) and forming or preforming the container from the preform by means of internal pressure, wherein the surrounding section of the preform is pressed through the die gap into a chamber surrounding the die cavity and is pressed in the chamber against a jaw pair with a fixed inner holding jaw (141) and a movable outer tear-off jaw (142); -laterally displacing the outer tear-off jaw (142) so that the surrounding section between the outer tear-off jaw (142) and the inner holding jaw (141) is torn off and the container is divided into two container halves (230, 240). The invention also relates to a forming die (100) suitable for carrying out the method.)
1. A method for manufacturing a plastic container (260) by internal pressure forming, comprising the steps of:
-arranging a hose-like preform (200) between mould parts (110, 120) of a forming mould (100) configured with a mould cavity (130);
-closing the forming die (100) and forming or preforming a container (220) from the preform (200) by means of internal pressure, wherein a surrounding section (210) of the preform (200) is pressed through a die gap (160) into a chamber (150) surrounding the die cavity (130) and is pressed in this chamber (150) relative to a jaw pair (140) with a fixed inner holding jaw (141) and a movable outer tear-off jaw (142);
-laterally advancing the outer tear-off jaw (142) so that the surrounding section between the outer tear-off jaw (142) and the inner holding jaw (141) is torn off and the container (220) is divided into two container halves (230, 240).
2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,
it is characterized in that the preparation method is characterized in that,
the forming tool (100) between the inner holding jaw (141) and the outer tear-off jaw (142) is cooled or heated by means of a temperature control element (145).
3. The method according to claim 1 or 2, comprising the further step of:
-opening the forming mould (100), wherein each one container half (230, 240) remains in a respective mould part (110, 120);
-fastening at least one insert (250) at least one of the container halves (230, 240);
-closing the forming mould (100), wherein the container halves (230, 240) are spliced; and blow-molding the spliced container, which is formed as completed herein;
-opening the forming mould (100) and de-moulding the finished container (260).
4. The method of claim 3, wherein the first and second light sources are selected from the group consisting of,
it is characterized in that the preparation method is characterized in that,
the mold pieces (110, 120) travel closer to each other when closing the forming mold (100) for forming the container (260) than when closing for preforming the container (220).
5. A forming die (100) for forming a hose-like preform (200) by internal pressure, in particular for manufacturing a plastic container (260) by using a method according to any one of the preceding claims, comprising:
-two mould parts (110, 120) which are configured with a mould cavity (130) and are movable relative to each other;
-at least one cavity (150) surrounding the mould cavity (130); and
-a pair of jaws (140) arranged around the mould cavity (130) in the chamber (150), with a fixed inner holding jaw (141) and a movable outer tear-off jaw (142).
6. The forming die (100) of claim 5,
it is characterized in that the preparation method is characterized in that,
at each of the two die parts (110, 120), a clamping jaw pair (140) with a fixed inner holding clamping jaw (141) and a movable outer tear-off clamping jaw (142) is arranged.
7. Forming die (100) according to claim 5 or 6,
it is characterized in that the preparation method is characterized in that,
a temperature control element (145) is arranged between the inner tear-off jaw (141) and the outer tear-off jaw (142).
8. Forming die (100) according to any of claims 5 to 7,
it is characterized in that the preparation method is characterized in that,
the outer tear-off jaw (142) is fastened at a slide (170) which at the same time laterally delimits the chamber (150).
9. Forming die (100) according to any of claims 5 to 8,
it is characterized in that the preparation method is characterized in that,
having a first closed position and a second closed position.
10. Forming die (100) according to claims 8 and 9,
it is characterized in that the preparation method is characterized in that,
the first and second closed positions are achieved by different travel paths of the slider (170).
Technical Field
The present invention relates to a method and a mould (or tool, Werkzeug) for producing plastic containers, in particular fuel containers, by internal pressure forming and in particular by blow forming (or blow forming, or blastormen).
Background
In blow molding, a heated and therefore fluid-viscous preform made of a thermoplastic material is blown open in a blow mold of a given shape by means of a gas, for example by means of compressed air, and is pressed against a mold wall of the given shape or against an inner wall of the mold cavity. After blowing, the hollow body produced by blowing is cooled in a mold until it possesses sufficient form rigidity and can be demolded. In a common method variant, a tubular preform is used, which can be produced directly beforehand by Extrusion (or Extrusion, Extrusion molding, or Extrusion blow molding) (so-called Extrusion blow molding).
Plastic containers for motor vehicles, such as in particular fuel containers (fuel tanks), can be produced by blow molding. Sometimes, various inserts, such as, for example, a level sender (or fill level sender, i.e., a villstandsgeber), venting and degassing elements, pumps, filters, anti-sloshing walls, valves, fastening elements, etc., have to be arranged in the interior of such plastic containers. Current efforts aim at introducing as many or all inserts into plastic containers as possible already during the manufacture of the plastic containers, which requires accessibility to the interior of the container.
Possible solutions are described in patent documents DE 10064801 a1, DE 102009030492 a1 and DE 102012001928 a 1.
Patent documents DE 102013203085 a1 and EP 2769825 a1, which form the closest prior art, describe a blow molding method (and apparatus) for producing hollow bodies, in particular fuel containers, in which a soft tubular preform is arranged between two parts of a blow mold, the blow mold not being completely closed, the preform being hermetically closed in the region of its ends and the interior region of the preform being subjected to a pressure medium in the gaseous state, so that the preform presses against the inner wall of the blow mold and performs the hollow body. In order to achieve a simple separation of the preform into two halves, it is provided that parts of the preform are gripped by means of clamping devices arranged at the blow mold and the preform is torn apart into two half pieces between the clamping devices, respectively. The clamping device has a clamping element which is displaceable in the opening and closing direction of the blow mold part and a stop edge which is arranged opposite to the end face thereof, wherein a groove is formed between the clamping element and the stop edge, into which groove the material of the preform is pressed in a bulge-like manner (or bulge-like manner, wulstartig) and which is displaced in order to clamp the material of the preform or the stop edge.
German patent application 102017202839.4 describes a method and a mold for producing plastic containers by internal pressure forming, in particular blow forming, of a preform, which is pressed out of a mold cavity and is gripped outside the mold cavity by means of a gripping device. By laterally pushing the gripping device, the gripped section is torn off at a tear-off edge arranged outside the mold cavity, and the formed container is divided into two container halves.
Disclosure of Invention
The object of the present invention is therefore to provide a further method and a device for producing plastic containers by internal pressure forming of tubular preforms, which do not have at least one of the disadvantages associated with the prior art, or at least only to a reduced extent.
This object is achieved by the method according to the invention with the features of patent claim 1 and by the shaping tool (device) according to the invention, in particular a blow-molding tool with the features of the claims. Preferred developments of the invention emerge analogously from the dependent patent claims, the following description and the drawings for both inventive subjects. Accordingly, a device or mold feature may accompany (or complement, i.e., einhergehen) a corresponding method feature and vice versa.
The method according to the invention has at least the following steps carried out in this order:
-arranging a hose-like preform between the mould parts of the (open) forming mould which are configured with the mould cavity;
closing the shaping mold (by advancing the mold parts toward one another in the closing direction) and shaping or at least preforming the container from the preform by means of internal pressure, i.e. by generating internal pressure with a gaseous pressure medium in the interior region of the preform, wherein the surrounding section (or surrounding section, i.e. the umlaufender abcchnitt) of the preform is pressed into a chamber surrounding the mold cavity through the mold gap (which is present or is also present between the mold parts) and is pressed in this chamber against the jaw pair with the fixed inner holding jaw and the movable outer tear-off jaw;
the outer tear-off jaw is pushed laterally, as a result of which the surrounding section outside the mold cavity between the moved, in particular outwardly moved, outer tear-off jaw and the fixed inner holding jaw is torn off, and as a result the container is divided into two container halves.
The lateral displacement of the tear-off jaws takes place with the forming tool closed. In other words, the forming die does not have to be opened in order to separate the formed or preformed container into two container halves. Lateral displacement is to be understood in particular to mean that the tear-off jaws are moved transversely to the closing direction or closing axis of the forming tool or tool part. Transverse here means that the axis of movement of the tear-off jaw preferably occupies an angle of between 45 ° and 90 ° and particularly preferably between 60 ° and 90 ° with respect to the closing axis. The tear-off jaw is in particular moved substantially perpendicularly (90 °) to the closing direction. The tear-off jaws are each moved outwardly (laterally outwardly) in this case, i.e. away from the mold cavity.
Furthermore, the method according to the invention may additionally have intermediate steps, sub-steps, preparation steps and/or further steps which are not elaborated on. The method according to the invention is preferably carried out with a forming or blow-forming tool according to the invention and can therefore have the preceding steps:
-providing a forming or blow-forming mould according to the invention.
The forming die used preferably comprises two die parts (die halves or die sides) configured with a cavity section. Preferably, a jaw pair is arranged around the mould cavity at each of the two mould parts, with an inner (i.e. facing the mould cavity), fixed holding jaw and an outer (i.e. facing away from the mould cavity), movable tear-off jaw. The clamping jaws are elements which protrude, i.e. protrude into the chamber and are configured, for example, in the form of rakes, clamps, blades, etc. The preform is pressed onto the clamping jaws in the relevant section by internal pressure, wherein a form fit (in particular without accompanying perforations) is obtained, for example by pressing the material of the preform over the clamping jaws in a bulge-like manner, and a tearing force can be exerted thereon on the relevant section. The area required for reliable tearing can be kept very small here. In addition, no gripping or clamping means are required.
Preferably, the shaping tool is (locally) cooled or heated in the region between the inner holding jaw and the outer tear-off jaw by means of a temperature control element. The material properties of the preform are thereby influenced in the relevant region by targeted cooling or heating in such a way that tearing is facilitated (for example, by brittle fracture or melt separation).
In order to be able to generate the internal pressure required for container forming in the hose-like preform, the preform is closed in a gas-tight manner at its axial ends. The tubular preform can be closed in a gas-tight manner, for example by welding, during the arrangement or during the closing of the shaping tool. However, the closed preform may also be provided as a prefabricated initial product. Gas (and also air) may already be enclosed in the closed preform so that when the forming die is closed an internal pressure sufficient for container forming is generated. However, the internal pressure is preferably generated by blowing a gaseous pressure medium into the interior of the closed preform, in particular by means of at least one blowing mandrel. According to a further method sequence, the container can be substantially completely formed or only preformed.
The method according to the invention may furthermore have the following steps carried out in this order:
-opening the forming mould by advancing the mould parts apart from each other, wherein a respective one of the container halves remains in the respective mould part;
-fastening at least one insert at least one of the container halves, in particular at the inner side;
-reclosing the forming tool by advancing the tool parts toward one another, wherein the container halves are joined together in a material-fit manner, for example, with a hot, subsequently heated or adhesive-provided edge, to form a container or a container balloon;
blow-molding the spliced container by applying the inner region of the container with a gaseous pressure medium, whereby the container is pressed against the inner wall section of the mold cavity and is thereby completely formed, i.e. whereby the final shape of the container to be manufactured is achieved (splicing and blow-molding may be performed sequentially, simultaneously or, in case of a corresponding sealing, also in reverse order);
-trimming the containers if necessary, in particular by means of a peripheral cutting device of the forming die;
opening the forming mold and demolding the finished plastic container provided with the insert.
Preferably, the mold pieces travel closer together when being reclosed for forming or completing the formed container (second closed position) than when previously closed for preforming the container (first closed position).
The forming tool according to the invention, wherein it is in particular a blow forming tool, comprises at least the following components:
-constructing two mould parts with mould cavities and movable relative to each other;
-at least one cavity (outer cavity) surrounding the mould cavity; and
a pair of jaws arranged in the chamber around the mold cavity with a fixed inner holding jaw and a movable or drivable, in particular laterally movable, outer tear-off jaw, which is provided for dividing the previously formed container into two container halves as explained above.
Furthermore, it is preferably provided that a temperature control element is arranged between the outer tear-off jaw and the inner holding jaw of the jaw pair for (local) cooling or heating as described above.
The external tear-off jaws can be fastened to a slide, in particular a laterally displaceable or movable slide, which at the same time laterally (i.e. laterally outwards) delimits a cavity around the mold cavity. The slides are preferably arranged as slides or slide pairs opposite one another at the two mould parts. The displacement of the slide can be effected by means of a suitable adjusting drive, for example a hydraulic cylinder, or else by means of a wedge-shaped slide mechanism.
Preferably, the forming die according to the invention has a first closed position for preforming the container and a second closed position for forming the container, in which the die parts are advanced closer together. The first and second closing positions can be realized by different (lateral) travel paths of the slides, in particular such that the opposing slides can occupy an inner position (starting position) which allows a first closing position between the mould parts and at least one outer position (end position) which is offset from one another, which allows a second closing position between the mould parts.
Drawings
Further features and advantages of the invention emerge from the following description with reference to the drawings. The features shown in the figures of the drawings and/or described below can be generic features of the invention independently of certain combinations of features, and the invention is accordingly modified.
Fig. 1 to 6 illustrate the manufacture of a plastic container according to the invention in schematic sectional views.
Detailed Description
The blow-
At the beginning of the manufacturing process, the preferably extruded, hose-like preform 200 is closed off air-tightly at its axial ends and positioned between the
After the blow-
When the blow-
The blow-
The
Upon this reclosing of the
The produced plastic container 260 with the
Alternatively to the operating method described above, it can be provided that, without preforming, on the first closure of the forming
REFERENCE SIGNS LIST
100 blow molding die
110 mould part
115 base plate
120 mould part
125 base plate
130 mould cavity
135 die segment
137 cutting device
140 jaw pair (plurality)
141 holding jaw
142 tear-off jaw
145 temperature regulating element
150 chamber
151 sub-chamber
152 sub-chamber
160 die gap
170 sliding block
190 heating device
200 preform
220 container
230 container half
240 container half
250 parts (multiple)
260 plastic container
A waste material
S direction of closure
v vertical line.
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