Method for producing a component having at least one cavity, and build and production device for producing such a component

Abstract

The invention relates to a method for producing a component having at least one cavity, in which first an injection molding material is introduced into an injection molding cavity (4) of an injection molding tool (5) at at least one material injection point, and then in order to produce the cavity, a fluid is injected into the injection molding cavity (4) at a fluid injection point, the bullet head (1) is pressed against the injection molding material in the injection molding cavity (4) along the movement path, so that a part of the injection molding material is pushed out of the injection molding cavity (4). According to the invention, the bullet head (1) is asymmetrical with respect to the longitudinal axis (7) thereof extending through the centre of gravity (9) of the bullet head (1), said longitudinal axis (7) extending through a discontinuous point (12) of the bullet head (1) on the side facing away from the fluid injection site and / or the geometric centre of gravity of the front side (11) of the bullet head (1). The invention also relates to a bullet (1) and a manufacturing device (2) for manufacturing a component having at least one cavity.

Description

Technical Field

[0001] The invention relates to a method for producing a component having at least one cavity, wherein firstly, an injection material is introduced into an injection cavity of an injection mold at at least one material injection point, and then, to produce the cavity, a projectile / projectile is pressed through the injection material in the injection cavity along a movement path by injecting a fluid into the injection cavity at a fluid injection point, so that a portion of the injection material is pushed out of the injection cavity. The invention also relates to a projectile for producing the component and a production device for producing the component. Background Art

[0002] For example, the publication DE 10 2008 215 592 B3 is known from the prior art. It describes a projectile for a casting device for producing hollow castings, wherein the casting device comprises a mold cavity, a filling device for filling the mold cavity with a flowable casting material, and a pushing device by which the projectile can be driven into the material filled into the mold cavity, preferably through the material, wherein the projectile extends along a longitudinal axis of the projectile, wherein the projectile has a non-rotationally symmetrical cross section at least in an axial contour section of its longitudinal extension.

[0003] Furthermore, publication DE 10 2010 015 452 B3 discloses a method for injection molding a molded part having at least two sections with different outer diameters, wherein a cavity located inside the molded part is produced by driving a projectile in the conveying direction through the still molten injectable material in the direction of the longitudinal axis of the molded part, for which purpose a pressurized fluid is introduced into the cavity behind the projectile in the conveying direction, which pressurized fluid pushes the projectile in the conveying direction. In order to achieve a wall thickness that is as constant as possible when the outer dimensions of the molded part vary, it is provided that a projectile is used that has at least one elastic or plastic section, which is limited by a space that the pressurized fluid can enter when pushing the projectile, wherein the volume of the space can be changed depending on the fluid pressure, wherein the pressure of the pressurized fluid is controlled or regulated in such a way that the space is enlarged and / or reduced in such a way that the effective outer diameter of the projectile has a predetermined value over the advancing path in the conveying direction. Summary of the invention

[0004] The object of the present invention is to specify a method for producing a component having at least one cavity which has advantages over known methods and in particular allows a reliable execution of the injection molding process with a high degree of process reliability.

[0005] According to the invention, this object is achieved by a method for producing a component having at least one cavity having the features of claim 1. It is provided that the projectile is asymmetrical about its longitudinal axis extending through the center of gravity of the projectile, the longitudinal axis extending through the geometric center of gravity of the projectile discontinuity on the side facing away from the fluid injection site and / or the front side of the projectile.

[0006] Advantageous embodiments of the invention with suitable improvements are given in the dependent claims. It should be pointed out that the exemplary embodiments described in the description are not restrictive; on the contrary, any modifications of the features disclosed in the description, the claims and the figures are possible.

[0007] The method described is used to produce a component, in particular when using a corresponding production plant which is configured and designed to carry out the method. In principle, the component is produced by injection molding, i.e. by introducing an injection molding material into an injection mold cavity of an injection mold which is a component of the production plant. In particular, the injection mold is an injection mold, preferably a multi-part injection mold, which is opened or can be opened to remove the produced component.

[0008] The injection material is introduced into the injection mold cavity at at least one material injection site. There may be only one single material injection site or the introduction may take place at a plurality of material injection sites spaced apart from one another. If a material injection site or at least one material injection site is mentioned within the scope of the description, the discussion is always equivalent and can be applied similarly to a plurality of material injection sites or each of a plurality of material injection sites.

[0009] As the injection molding material, preferably a thermoplastic is used. It can also be provided that the injection molding material is a composite material, in particular a fiber composite material. In this case, the injection molding material has a matrix composed of plastic, in particular a thermoplastic, and reinforcing fibers, such as carbon fibers, glass fibers, aramid fibers, basalt fibers or natural fibers. The injection molding material can have a metal content to make it electrically conductive.

[0010] The manufactured component should have at least one cavity. There may be only one single cavity, but alternatively a plurality of cavities may be produced in the component. These cavities may always be spaced apart from one another or at least partially merge into one another. If a cavity or at least one cavity is mentioned, the discussion is equivalent and preferably applies to each of the plurality of cavities, as long as they are present. Preferably, the cavity is a channel-shaped or tubular cavity and, in this respect, has an elongated shape. The cavity can be designed for a targeted adjustment of the rigidity of the component, so that the cavity improves the load-bearing capacity of the component. For example, the component is a component of a motor vehicle battery, in particular a battery tray, a battery tray cover or a cooling plate.

[0011] In principle, the cavity can be produced during the subsequent process of injection molding, for example by means of a chip removal method. However, this is very complex and also results in a high demand for the injection molding material. For this reason, it is provided that the cavity is produced by means of a bullet during the injection molding, i.e. when the injection molding material is in a flowable state in the injection mold cavity. For this purpose, the injection molding material preferably has a temperature above its glass transition temperature or crystallization temperature.

[0012] After the injection molding material has been introduced into the injection molding cavity, the projectile is moved along the movement path through the injection molding cavity and thus through the injection molding material. The movement path can always extend in a straight line. However, it is preferably provided that the movement path has at least one bend or turn. For example, it is provided that the movement path extends partially in a straight line and partially in a curved line, in particular, a curved area of ​​the movement path is received between two straight areas of the movement path, or vice versa.

[0013] In order to form the cavity, the bullet pushes a part of the injection material by the movement of the bullet. This part of the injection material is pushed out of the injection mold cavity by the bullet. For example, it is provided that the injection material is pushed in a way that the material is pressed from the rear, so that the injection material is guided out of the injection mold cavity through the gate. Preferably, the bullet is also moved out of the injection mold cavity through the gate. Subsequently, the bullet is led out of the hot runner of the injection mold into the cold runner. Alternatively, however, the pushing of the injection material can also be carried out by blowing.

[0014] The bullet is moved by injecting a fluid into the injection mold cavity at the fluid injection site. The fluid pushes the bullet forward from the fluid injection site and causes it to pass through the injection mold cavity, i.e., when a cavity is formed. It can be provided that the bullet remains in the injection mold cavity until the injection molding is completed and is thus removed from the injection mold cavity together with the component. Alternatively, it is provided that the bullet is passed through the injection material and pushed out of the injection mold cavity by means of the fluid, so that after the injection molding is completed, the component can be removed or demoulded from the injection mold cavity independently of the bullet.

[0015] In this regard, injection molding is carried out when using so-called projectile injection technology (PIT). More precisely, it is projectile assisted injection molding, which is also referred to as projectile assisted injection molding (PAIM). Injection molding is carried out by dispensing and plasticizing injection molding material, and subsequently, injection molding material is introduced into the injection mold cavity. In order to achieve reliable component molding and high process reliability, it is preferably provided with re-pressurization (Nachdrücken) of injection molding material, that is, before the projectile is pressed through the injection molding material. In addition, it can be provided that before the projectile is moved through the injection molding material, the injection molding material introduced into the injection mold cavity is first at least partially cooled. For example, the projectile is made of metal, ceramic or polymer. In any case, the melting temperature of the material used for the projectile is higher than the melting temperature of the injection molding material in contact with it.

[0016] But in any case, the movement of the bullet is before the component is demoulded, that is, before the component is taken out of the injection mold cavity, in particular before the injection mold is opened for demoulding. The bullet moves through the injection material to form a cavity. The advantage of using a bullet is that a substantially constant wall thickness is generated at least along a straight line of movement path when using a symmetrical bullet. The known bullets used for this approach usually have an outer contour that is symmetrical about its longitudinal center axis. For example, when observed in a cross section, the bullet is always circular or at least almost circular along its longitudinal center axis.

[0017] Known warheads are at most warheads in which a bridge extending in the longitudinal direction of the warhead extends outwards in the radial direction starting from a circular cross section. The bridge thus protrudes beyond the base body of the warhead in the radial direction and extends parallel to the longitudinal center axis of the warhead or the base body. In this respect, it has its maximum extension in a direction oriented parallel to the longitudinal center axis of the warhead.

[0018] A bullet that is always circular in cross section can only be used to produce a circular cavity. This bullet ensures high process reliability because, due to its symmetrical design, the bullet does not tilt during movement through the injection molding material. On the contrary, if the bullet has a bridge, the bridge is used to form a groove in the component. Due to the bridge, the center of gravity of the bullet changes. If suitable structural countermeasures are not taken at the bullet, the injection molding process must be controlled so that the bullet does not tilt. This leads to a reduction in the speed at which the bullet can be pressed through the injection molding material.

[0019] In order to flexibly design the shape of the cavity on the one hand and to achieve high process stability on the other hand, it is provided according to the invention that the bullet has a longitudinal axis extending through the center of gravity of the bullet. The bullet is designed to be asymmetrical with respect to the longitudinal axis. Preferably, the bullet has a profile that is closed in the circumferential direction, that is, a profile without interruptions. In particular, there are no notches or the like extending in the axial direction based on the longitudinal axis at the outside of the bullet. This achieves that the wall thickness of the manufactured component is extremely uniform. In addition, the longitudinal axis extends through the geometric center of gravity of the bullet discontinuity and / or the front side of the bullet.

[0020] For example, the asymmetric form of the bullet is understood to mean that, when observed in a cross section, the bullet is significantly different from a circle, and in particular, the size of the bullet in the horizontal direction is greater than its size in the vertical direction. Preferably, the size in the horizontal direction is at least 2 times, at least 3 times or at least 4 times greater than its size in the vertical direction. For example, when observed in a cross section, the bullet is flat over its entire width, and on the other hand, again in the cross section, the bullet is continuously curved. Alternatively, the bullet is polygonal or polygonal in the cross section. Preferably, the form of the bullet is different from a quadrilateral, in particular a square. For example, the bullet is at least pentagonal or at least hexagonal.

[0021] The center of gravity of the warhead is understood in particular to be the geometric center of gravity of the warhead, in particular the geometric center of gravity in the cross section in which the warhead has its maximum dimension in the radial direction based on the longitudinal axis. In this regard, the center of gravity can be the geometric center of gravity of the entire warhead, i.e. the volume center of gravity of the warhead, or alternatively the geometric center of gravity in the cross section of the warhead along the longitudinal axis of the warhead, i.e. the surface center of gravity in the cross section in which the maximum cross section or the maximum cross-sectional area of ​​the warhead is preferably present over the entire warhead.

[0022] It can be provided that the longitudinal axis is at least partially offset from the center in the projectile and accordingly cannot be referred to as a longitudinal center axis. Particularly preferably, the longitudinal axis is arranged parallel to the direction of movement of the projectile along the movement path. In other words, the projectile can be pressed through the injection molding material in such a way that the longitudinal axis is always parallel to the direction of movement of the projectile along the movement path. Preferably, the projectile is moved through the injection molding material in such a way that the center of gravity is always located on the movement path. In particular, the movement direction is understood to be a tangent to the movement path at the center of gravity.

[0023] The discontinuity of the bullet is understood to be an edge, corner or tip of the bullet. Here, the discontinuity should not be explained in a mathematical sense, but in a technical sense. In this regard, the discontinuity is the point where multiple faces of the bullet or multiple edges of the bullet converge. Preferably, the discontinuity of the bullet is located on its front side, that is, on its side facing away from the fluid injection point. In particular, the discontinuity is located at the front end of the bullet, that is, at the very front end of the bullet.

[0024] Alternatively or additionally, the longitudinal axis extends through the geometric center of gravity of the front side of the bullet. The front side is understood to be the front end of the bullet, so that the geometric center of gravity is located on the side of the bullet facing away from the fluid injection site or at the frontmost end of the bullet. In particular, the geometric center of gravity is in the bullet cross section on the front side of the bullet.

[0025] As the projectile moves along the displacement path, the discontinuity or the center of gravity is located in front of the projectile, i.e., it penetrates the injection molding material first. The described arrangement of the longitudinal axis achieves a high longitudinal stability of the projectile during its displacement through the injection molding material, so that tilting is virtually avoided even at high displacement speeds and thus a high process reliability is achieved.

[0026] A refinement of the present invention provides that as a projectile, a projectile is used which has a base body and a guide bridge protruding from the base body in a radial direction based on the longitudinal axis, the guide bridge completely surrounding the base body in a circumferential direction. The projectile has a base body and a guide bridge. The guide bridge completely and continuously surrounds the base body in a circumferential direction based on the longitudinal axis and extends outward from the base body in a radial direction, i.e., protrudes from the base body in a radial direction.

[0027] Preferably, the guide bridge protrudes uniformly beyond the base body in the radial direction, i.e., always has a defined extension in the radial direction in the circumferential direction. Accordingly, the guide bridge has the same shape as the base body, but is designed to have larger dimensions in the radial direction. For example, the guide bridge protrudes beyond the base body in the radial direction by at least 1 mm, at least 2 mm, or at least 4 mm. Additionally or alternatively, the protrusion is at most 8 mm, at most 6 mm, or at most 4 mm. In particular, the protrusion is 1 mm to 8 mm, 2 mm to 6 mm, or approximately or exactly 4 mm.

[0028] Preferably, the guide bridge is the part of the projectile which is located outermost in the radial direction and in this respect defines the wall thickness of the component to be manufactured. Preferably, the guide bridge has a dimension in the axial direction of at least 10%, at least 15% or at least 20% of the total extension of the projectile in the axial direction. Additionally or alternatively, the guide bridge has a dimension in the axial direction of at most 30%, at most 25% or at most 20% of the total extension of the projectile in this direction.

[0029] Preferably, the guide bridge is limited by a guide surface on its side located on the outside in the radial direction. The guide surface thus closes the guide bridge outward in the radial direction. The guide surface can extend continuously in the circumferential direction, i.e., for example, always continuously curved, or partially straight and partially continuously curved. However, it can also be provided that the guide surface consists of a plurality of partial surfaces that are adjacent to each other at an angle in the circumferential direction. This means that two of the partial surfaces intersect each other at an angle greater than 0° and less than 180°.

[0030] Preferably, the guide surface in the circumferential direction always extends parallel to the longitudinal axis in the axial direction, so that the guide bridge has the shape of a straight cylinder with an arbitrary base surface. However, it can also be provided that the guide surface is angled relative to the longitudinal axis. In this case, the angle of inclination of the guide surface relative to the longitudinal axis is preferably always the same in the circumferential direction. This type of projectile design allows particularly reliable guidance during movement along the movement path and thus high process reliability.

[0031] A refinement of the invention provides that the fluid pressure of the injected fluid is adjusted as a function of the position of the projectile relative to the path of travel. For example, it is provided that the fluid pressure is adjusted to a certain theoretical pressure, in particular adjusted to the theoretical pressure. This allows a uniform movement of the projectile along the path of travel. Particularly preferably, additionally or alternatively, the fluid pressure is adjusted as a function of the geometry of the cavity. Additionally or alternatively, input parameters of the manufacturing device are taken into account in the determination of the fluid pressure. Particularly preferably, the fluid pressure is adjusted with the aid of artificial intelligence, for example when using artificial neural networks and / or deep learning. The described approach again achieves a particularly high process reliability.

[0032] A refinement of the present invention provides that the bullet is arranged in the injection mold cavity before the injection molding material is introduced into the injection mold cavity. This means that the bullet is covered by the injection molding material during the introduction of the injection molding material. Therefore, after the injection molding material is introduced, the bullet is already at the starting point of the movement path in its initial position and can move along the movement path from here. Alternatively, it is provided that the bullet is inserted only after the injection molding material is introduced into the injection mold cavity, in particular through the corresponding receiving portion. Both variants enable the reliable manufacture of the cavity by means of the bullet.

[0033] A refinement of the invention provides that the bullet is arranged in the injection mold cavity in such a way that the injection mold fluid injector for injecting the fluid engages in the guide receiving portion of the bullet. The fluid injection for moving the bullet along the movement path is completed using the fluid injector. Therefore, the fluid enters the injection mold cavity through the fluid injector. In order to achieve a reliable alignment of the bullet, the bullet has a guide receiving portion. The bullet is arranged in such a way that the fluid injector is located in the guide receiving portion.

[0034] Preferably, the guide receiving portion is designed so that the projectile is supported on the fluid injector in the radial direction. Therefore, after the fluid injector is arranged in the guide receiving portion, the fluid injector rests on the projectile at a plurality of locations spaced apart from each other in the circumferential direction, so that the projectile is securely held in a positively locking manner in the radial direction. For example, respective two of these locations are diagonally opposite to each other.

[0035] Preferably, the guide receptacle is designed symmetrically with respect to the longitudinal axis, so that the longitudinal axis extends in a manner that passes centrally through the guide receptacle. As a result, the projectile is driven by the fluid in its center of gravity, so that together with the projectile design described further, tilting of the projectile is reliably prevented. The described approach allows reliable alignment of the projectile and thus high process reliability.

[0036] A further development of the invention provides that the bullet is inserted into a recess of the injection mold which surrounds the fluid injector and is adapted in shape and / or size to the bullet. The recess is located in a wall of the injection mold which delimits the injection mold cavity. The recess surrounds the fluid injector, i.e. the fluid injector is arranged in the recess and extends, for example, from the bottom of the recess in the direction of an access opening of the recess, via which the recess transitions into the injection mold cavity. Preferably, the fluid injector extends from the recess into the injection mold cavity.

[0037] In order to achieve particularly reliable positioning of the projectile, the projectile is inserted into the recess. In this case, the recess is adapted to the projectile, i.e., adapted in shape and / or in size. This means that, viewed in cross section, the shape of the recess corresponds to the shape of the projectile. Preferably, this also applies to the size. Therefore, it is particularly preferred that the recess is designed so that the projectile inserted into the recess is held in the recess in a positively locked manner in the radial direction by the projectile resting against the edge of the limiting recess. As a result, particularly reliable positioning of the projectile is achieved again.

[0038] A development of the invention provides that, in addition to the cavity, at least one further cavity is produced in the component, in particular by means of a further projectile and / or by fluid injection. The production of a plurality of cavities in the component has already been indicated. Both the cavity and the further cavity are components of these multiple cavities. The cavity and the further cavity can be produced in the component in a manner that is always spaced apart from one another. However, it can also be provided that the cavities at least partially merge into one another.

[0039] For example, another cavity is manufactured by means of another bullet preferably designed similarly to the already described bullet. It can be provided that the other bullet is identical to the bullet. Alternatively, the other bullet has different shapes and / or different sizes to manufacture cavities of different forms or sizes. Preferably, the other bullet is also pressed through the injection molding material by means of the injection of a fluid, i.e., along another movement path at least partially spaced apart from the movement path. But it can also be provided that the other cavity is manufactured only by the injection of a fluid, i.e., without using another bullet. In any case, a flexible component form is achieved.

[0040] A development of the invention provides that at least one insert is overmolded and / or post-molded with an injection molding material in an injection molding cavity. The insert is inserted into the injection molding cavity before the injection molding material is introduced into the injection molding cavity. Preferably, the insert is made of a material different from the injection molding material. For example, the insert is made of metal. With the aid of the insert, the properties of the component, in particular its rigidity, can be adjusted in a targeted manner. Preferably, the insert is pretreated in such a way that the injection molding material bonds better to it. For example, the surface of the insert is heat treated, in particular with the aid of plasma.

[0041] The invention further relates to a projectile for producing a component having at least one cavity, in particular for carrying out a method according to an embodiment of the invention within the scope of the description, wherein the projectile is arranged and designed to be arranged in an injection cavity of an injection mold, into which injection material can be introduced at at least one material injection point, and in order to produce the cavity, the projectile is pressed along a movement path through the injection material in the injection cavity by injecting a fluid into the injection cavity at a fluid injection point, so that a portion of the injection material is pushed out of the injection cavity. It is provided that the projectile is asymmetrical about its longitudinal axis extending through the center of gravity of the projectile, the longitudinal axis extending through the geometric center of gravity of the projectile discontinuity located on the side facing away from the fluid injection point and / or the front side of the projectile.

[0042] The advantages of this design of the warhead for manufacturing the component or this approach for manufacturing the component have been pointed out. Both the warhead for manufacturing the component and the method for manufacturing the component can be improved according to the embodiments within the scope of the description, so that reference is made to these embodiments in this regard.

[0043] A further development of the invention provides that the guide bridge protrudes continuously from the base body of the projectile in the radial direction based on the longitudinal axis in the circumferential direction. Such a design of the projectile has already been indicated. The guide bridge serves to reliably guide the projectile along the movement path in the radial direction based on the longitudinal axis. The guide bridge protruding from the base body serves in particular as a sealing bridge and in this respect prevents the injection molding material from flowing excessively through the projectile. This design of the projectile enables the production of components with particularly thin walls.

[0044] A further development of the invention provides that the guide bridge protrudes uniformly from the base body. In this respect, the guide bridge has a constant distance from the base body in the radial direction on the circumference of the base body. This reliably prevents the projectile from tilting.

[0045] Finally, the present invention relates to a manufacturing device for manufacturing a component having at least one cavity, in particular for carrying out a method according to an implementation scheme within the scope of the description, wherein the manufacturing device is arranged and designed to first introduce injection molding material into an injection mold cavity of an injection mold at at least one material injection site, and then, in order to manufacture the cavity, a projectile is pressed through the injection molding material in the injection mold cavity along a movement path by injecting a fluid into the injection mold cavity at a fluid injection site, thereby pushing a portion of the injection molding material out of the injection mold cavity.

[0046] It is provided that the bullet is asymmetrical about its longitudinal axis extending through the center of gravity of the bullet, which extends through the geometric center of gravity of the bullet discontinuity located on the side facing away from the fluid injection site and / or the front side of the bullet. With regard to advantages and possible advantageous improvements, reference is again made to the other embodiments of the description.

[0047] The features and feature combinations described in the specification, in particular the features and feature combinations described in the following description of the figures and / or shown in the figures, can be used not only in the respectively given combination, but also in other combinations or alone, without departing from the scope of the present invention. Thus, embodiments that are not explicitly shown or described in the specification and / or the figures but can be derived from or deduced from the described embodiments are also considered to be included in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention will be described in more detail below based on the embodiments shown in the drawings without limiting the present invention. The drawings show:

[0049] Figure 1 A first schematic diagram showing a warhead in a first embodiment,

[0050] Figure 2 A second schematic diagram showing the warhead in the first embodiment,

[0051] Figure 3 A first schematic diagram showing a warhead in a second embodiment,

[0052] Figure 4 a second schematic diagram showing a warhead in a second embodiment, and

[0053] Figure 5 A third schematic diagram shows the warhead in the second embodiment. DETAILED DESCRIPTION

[0054] Figure 1A schematic diagram of a projectile 1 in a first embodiment is shown, which is used in a production device 2 for producing a component (not shown). A fluid injector 3 is shown in the production device 2, which is used to introduce a fluid into an injection mold cavity 4 of an injection mold 5 (only shown schematically) of the production device 2. The production device 2 is used to produce a component, in which a cavity is produced when using the projectile 1. For this purpose, the injection molding material is first introduced into the injection mold cavity 4, and then the projectile 1 is pushed along a displacement path through the injection molding material located in the injection mold cavity 4.

[0055] Before the projectile is moved along the displacement path, the projectile 1 is arranged in the injection mold cavity 4 in such a way that the fluid injector 3 engages in the guide receptacle 6 of the projectile 1. Preferably, the fluid injector 3 and the guide receptacle 6 are designed in such a way that the fluid injector 3 is held in a positively locking manner in the radial direction with reference to the longitudinal axis 7. In order to further improve the positioning of the projectile 1, a recess 8 is provided in the injection mold 5, into which recess the projectile 1 is inserted before the projectile is moved along the displacement path.

[0056] The projectile 1 has a center of gravity 9, which is the geometric center of gravity in a cross section of the rear side 10 of the projectile 1. In this respect, the center of gravity 9 is located on the side of the projectile 1 facing the fluid injector 3, or in a corresponding cross section based on the longitudinal axis 7. The longitudinal axis 7 extends through the center of gravity 9. The longitudinal axis extends in the direction in which the projectile 1 has its largest dimension. In particular, the longitudinal axis intersects not only the rear side 10 of the projectile 1 but also its front side 11.

[0057] The longitudinal axis 7 oriented in this way intersects with a discontinuous portion 12 of the bullet 1, which is located on the front side 11 of the bullet, that is, on the side of the bullet 1 facing away from the fluid injector 3. In the illustrated embodiment, the discontinuous portion 12 is formed by the edge of the bullet 1. For example, the longitudinal axis 7 intersects the edge in the center. Preferably, the edge extends parallel to the following transverse axis of the bullet 1, that is, in the direction of the transverse axis, the bullet 1 has its second largest dimension. The transverse axis is perpendicular to the longitudinal axis 7 and is also perpendicular to the vertical axis. In the direction of the longitudinal axis 7, the bullet 1 has a length, in the direction of the transverse axis, the bullet has a width, and in the direction of the vertical axis, the bullet has a height. The length is greater than the width and the height, the width is less than the length and greater than the height, and the height is less than the length and less than the width.

[0058] The projectile 1 has a base body 13 and a guide bridge 14 protruding from the base body 13 in the radial direction with reference to the longitudinal axis 7. The guide bridge 14 is delimited on the outside in the radial direction by a guide surface 15, which is a straight cylindrical circumference. Preferably, the guide bridge 14 is arranged on the rear side 10 of the projectile 1 or forms the rear side at the same time. In this regard, the guide surface 15 surrounds the center of gravity 9 in the circumferential direction.

[0059] Figure 2 A second schematic diagram of a bullet in its first embodiment is shown. This figure shows that the bullet 1 has a plurality of guide receptacles 6 for a plurality of fluid injectors 3. The guide receptacles 6 all lead into a receptacle 16, which is made on the rear side 10 of the bullet and itself receives two guide receptacles 6. The receptacle 16 is limited radially outwardly by an edge 17, which is designed to be continuous in the circumferential direction. The edge 17 is formed by the guide bridge 14, which overlaps the guide surface 15, especially when viewed in the axial direction. The arrow 18 indicates the direction of movement of the bullet 1 along the already mentioned movement path. Here, the movement direction is arranged parallel to the longitudinal axis 7 along the entire movement path.

[0060] Figure 3 A schematic diagram of a warhead 1 in a second embodiment is shown, and a manufacturing device 2 is partially shown. The second embodiment of the warhead 1 is similar to its first embodiment, so that reference is made to the above embodiments and only the differences are pointed out below. The difference lies mainly in the shape of the warhead. In the first embodiment, the guide surface 15 always or at least mostly has a continuous direction in the circumferential direction, while now the direction is discontinuous. In this regard, the guide surface 15 is composed of a plurality of partial surfaces, wherein respective two of these partial surfaces intersect each other at an angle greater than 0° and less than 180°.

[0061] In particular, the guide bridge 14 is trapezoidal or at least approximately trapezoidal, viewed as a whole. The discontinuity 12 is formed by the tip of the bullet 1, at which the base 13 of the bullet 1 converges conically. It can be seen that the discontinuity 12 corresponds to the geometric center of gravity of the front side 11 of the bullet 1 or is located in this geometric center of gravity. In this regard, the longitudinal axis 7 extends through this geometric center of gravity. In the example shown, the longitudinal axis 7 extends through the corresponding geometric center of gravity not only on the rear side 10 but also on the front side 11 in the corresponding cross section. At the same time, the longitudinal axis 7 is oriented parallel to the guide surface 15. As a result, a particularly reliable guide is achieved while having good sealing.

[0062] It can be seen that the warhead consists of a plurality of differently shaped sections in the direction of the longitudinal axis 7. The first region is received in the guide bridge 14. The second region is directly adjacent to the first region and is polygonal. The size of the second region decreases in the direction away from the guide bridge 14 in the axial direction. The third region is directly adjacent to the second region, and the cross section of the third region is circular. For example, the third region is conical or conical, or the third region - as shown in the figure - is always circular in cross section and has a size that decreases with increasing gradient over its entire extension in the radial direction.

[0063] Figure 4The schematic diagram of the warhead 1 is shown again in its second embodiment. The same applies to Figure 5 .

[0064] List of reference numerals:

[0065] 1 Warhead

[0066] 2 Manufacturing Equipment

[0067] 3 Fluid Syringes

[0068] 4 Injection mold cavities

[0069] 5Injection mold

[0070] 6. Guide receiving part

[0071] 7 Vertical axis

[0072] 8 recesses

[0073] 9 Center of Gravity

[0074] 10 Rear

[0075] 11 Front

[0076] 12 Discontinuities

[0077] 13 Matrix

[0078] 14 Guide bridge

[0079] 15 Guide surface

[0080] 16 Reception Department

[0081] 17 Edge

[0082] 18 Arrow

Claims

1. A method for producing a component having at least one cavity, wherein: First, a molding material is introduced into an injection mold cavity (4) of an injection mold (5) at at least one material injection point, and then, in order to produce a cavity, a fluid is injected into the injection mold cavity (4) at the fluid injection point, and a bullet (1) is pressed through the molding material in the injection mold cavity (4) along a movement path, thereby pushing a part of the molding material out of the injection mold cavity (4), It is characterized in that The bullet (1) is asymmetric about its longitudinal axis (7) extending through the center of gravity (9) of the bullet (1), and the longitudinal axis (7) extends through a discontinuity (12) of the bullet (1) located on the side facing away from the fluid injection site and / or the geometric center of gravity of the front side (11) of the bullet (1).

2. The method according to claim 1, characterized in that: As a projectile (1), a projectile is used which has a base body (13) and a guide bridge (14) which projects beyond the base body (13) in a radial direction relative to a longitudinal axis (7) and which completely surrounds the base body (13) in a circumferential direction.

3. The method according to any one of the preceding claims, characterized in that The projectile (1) is arranged in the injection mold cavity (4) in such a way that the fluid injector (3) of the injection mold (5) for injecting the fluid engages in the guide receptacle (6) of the projectile (1).

4. The method according to any one of the preceding claims, characterized in that The bullet (1) is inserted into a recess (8) of an injection mold (5) surrounding the fluid injector (3) and adapted in shape and / or size to the bullet (1).

5. The method according to any one of the preceding claims, characterized in that In addition to the cavity, at least one further cavity is produced in the component.

6. The method according to any one of the preceding claims, characterized in that At least one insert part is overmolded and / or post-molded with an injection molding material in an injection molding cavity (4).

7. A method for producing a component having at least one cavity, in particular a projectile (1) for carrying out the method according to any one or more of claims 1 to 6, wherein: The bullet (1) is arranged and designed to be disposed in an injection mold cavity (4) of an injection mold (5), into which injection material can be introduced at at least one material injection point, and in order to produce a cavity, a fluid is injected into the injection mold cavity (4) at the fluid injection point, and the bullet is pressed through the injection material in the injection mold cavity (4) along a movement path, so that a part of the injection material is pushed out of the injection mold cavity (4), It is characterized in that The bullet (1) is asymmetric about its longitudinal axis (7) extending through the center of gravity (9) of the bullet (1), and the longitudinal axis (7) extends through a discontinuity (12) of the bullet (1) located on the side facing away from the fluid injection site and / or the geometric center of gravity of the front side (11) of the bullet (1).

8. The bullet according to claim 7, characterized in that The guide bridge (14) protrudes continuously in the circumferential direction from the base body (13) of the projectile (1) in the radial direction based on the longitudinal axis (7).

9. A warhead according to any one of the preceding claims, characterised in that The guide bridge (14) protrudes uniformly from the base body (13).

10. A production device (2) for producing a component having at least one cavity, in particular for carrying out the method according to any one or more of claims 1 to 6, wherein: The manufacturing device (2) is arranged and designed to first introduce the injection molding material into the injection mold cavity (4) of the injection mold (5) at at least one material injection point, and then, in order to produce the cavity, the projectile (1) is pressed through the injection molding material in the injection mold cavity (4) along a movement path by injecting a fluid into the injection mold cavity (4) at the fluid injection point, thereby pushing a part of the injection molding material out of the injection mold cavity (4), It is characterized in that The bullet (1) is asymmetric about its longitudinal axis (7) extending through the center of gravity of the bullet (1), and the longitudinal axis (7) extends through the geometric center of gravity of the discontinuity (12) of the bullet (1) located on the side facing away from the fluid injection site and / or the front side (11) of the bullet (1).

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