INSERT, TOOL, DEVICE AND METHOD FOR MANUFACTURING MOLDED PARTS WITH A REDUCTION

Abstract

The present invention relates to a tool insert for producing recessed molded parts, comprising a first component, a second component separate from the first component and having a projection extending toward the first component, an extension element disposed between the first and second components and movable with the first component, and an opening in the extension element into which the projection of the second component can enter, wherein the outer circumference of the extension device increases and the opening is closed by the projection. The invention also relates to a tool, a device, and a method for producing recessed molded parts.

Description

INSERT, TOOL, DEVICE AND METHOD FOR MANUFACTURING MOLDED PARTS WITH A REDUCTION FIELD OF INVENTION The invention relates to an insert, a tool, a device, and a method for producing molded parts with a recess, in particular molded parts in the millimeter range. BACKGROUND OF THE INVENTION Injection molding tools and devices are used primarily to produce molded parts made of plastic. Increasing miniaturization also necessitates molded parts with recesses, despite their small size. A recess can be used to mechanically connect a molded part to other parts, for example, by breaking it apart. Core draws, or cores, are often used in injection molding processes to create recesses or threads. Both core draws and cores can vary in their application, at least in some aspects. A core draw is a core that is divided in an injection molding machine, where a central core is tapered and can pull the outer core portions inward or push them outward by means of an axial movement. A core draw uses an axial or radial movement to move segments of the core draw so that a notch or thread can be created. Document DE 10 2011 011 784 Al relates to a collapsible core as part of a tool for plastic injection molding, in particular for a tool for injection molding recessed objects. The collapsible core has at least three main segments and three intermediate segments. Document DE 10 2012 208 563 Al relates to a foldable core as part of a tool for producing injection-molded or die-cast parts. The invention is described using an embodiment in which at least three outer segments are arranged around the core and mounted on the tool such that they can only move radially. An inner segment is arranged between two adjacent outer segments, which can also only move radially. Due to their structure and function, folding cores and core extractors require many separate segments. Because of the large number of segments, both systems have a significant diameter and length. The smallest diameter of a recess or opening in a molded part that can be created using these systems is approximately 12 mm. Further reduction is not possible because the segments cannot be reduced any further without compromising the extraction function of the core or folding core. Therefore, the aforementioned systems are not suitable for the production of small molded parts, i.e., molded parts with an inner diameter of less than 12 mm that have at least one recess. SUMMARY OF THE INVENTION Therefore, it is an objective of the present invention to provide simple devices and methods with which small molded parts with a recess can be produced. The objective is achieved by means of an insert according to claim 1, a tool according to claim 10, a device according to claim 11, and a method for producing molded parts with a recess according to claim 12. Other advantageous embodiments of the invention can be found in the dependent claims, the description, and the drawings. In particular, the objective is achieved by means of an insert for a tool for producing molded parts with a recess, having a first component, a second component, spaced from the first component and having a projection extending into the first component, an extension element located between the first and second components, and preferably movable with the first component, and an opening in the extension element into which the projection of the second component can enter, wherein the outer circumference of the extension element increases and the opening is closed by the projection. The insert is specifically an injection molding insert for an injection molding tool. The insert allows for the formation of at least one recess in a molded part. The insert's structure remains simple, and it can be very small in size. As a result, even very small molded parts with a recess can be produced. Since the extension mechanism is located only on the outer circumference of the insert, it can have a solid core. The solid core, preferably a shaft, provides stability to the insert. Furthermore, both the solid core and the insert itself can be reduced to almost any size without compromising the insert's functionality. Preferably, a collapsible core also includes a hollow cylinder in which, for example, a prestressing element is arranged. The first and / or second component preferably has a maximum outside diameter of less than 15 mm, preferably less than 12 mm, and even more preferably less than 10 mm. Due to the size of the outside diameter of the forming components, gaps or openings with the same diameters can be formed within a molded part. This allows the extension element to expand gradually without additional assistance. The extension element preferably comprises an extension ring. An extension ring is a component that is easy to manufacture. Therefore, its acquisition is easy and inexpensive. Furthermore, an extension ring can be changed easily and quickly, simplifying the maintenance of the insert and / or tool. Preferably, the opening has a shape complementary to that of the projection, so that the opening closes with the projection inserted. The closed opening completely seals the extension element, preventing any molding compound from penetrating the gaps. The volume of the protrusion is preferably greater than the volume of the opening in its base state. This size difference has the effect of forcing or separating the extension element when the protrusion is inserted into the opening. This increases the reach of the extension element. On the other hand, the separation generates an opposing compressive force on the extension element within the protrusion, so that both parts are tightly pressed together. Furthermore, at least the first component, the extension element, and the second component in the longitudinal direction of the insert are preferably compressed and held in the desired position by a clamping force applied to the insert through the halves of a tool, creating a closed sealing surface. This prevents gaps into which the molding compound could inadvertently penetrate. The first component and the extension element preferably have a smaller outer diameter than the second component in its base state. This has the advantage that the leading end of the insert can be easily separated from the resulting molded part by moving it in the direction of the second component. Furthermore, it is possible, for example, by extending the extension element to the outer diameter of the second component, to create a recess in the area of ​​the first component in a molded part. The greater the difference in outer diameter between the first component with the extension element in its base state and the second component, the deeper the recess can be. In particular, the outer diameter of the extension element in its extended state, i.e., with the projection fully inserted, does not have to match the outer diameter of the second component. Preferably, the extension element is held loosely in its alignment with respect to the first component by means of clamping. Loose mounting has the advantage that the extension element is held in a specific position or orientation with respect to the first component, but its size or circumference can change. Clamping it in a specific position or orientation ensures that the opening of the extension element and the projection of the second component are always opposite each other. In particular, in the case of an extension ring, the clamping means prevent displacement or slippage around the X-axis. The aforementioned objective is also achieved, in particular, by a tool for producing molded parts with a recess, which has at least two tool halves and an insert, wherein at least two tool halves surround the insert in the closed state and form at least one cavity, so that a molded part with at least one recess can be formed. The tool is, in particular, an injection molding tool. Specifically, the tool can produce molded parts with a recess and dimensions in the millimeter range and / or cavities or openings with diameters of less than 12 mm. The aforementioned objective is also achieved in particular by a device for producing molded parts with a recess, which has at least one tool and at least one nozzle configured to introduce molten molding compound, preferably under pressure, into recesses in the tool. The device is, in particular, an injection molding device. The aforementioned objective is also achieved in particular by a method for producing molded parts with a recess, preferably using a tool and / or device, wherein the method has the following steps: Encircling an insert using at least two halves of the tool, so that at least one recess is formed, whereby the circumference of an extension element in the insert is increased and closed by encircling, injecting a molding compound into at least one recess, curing the molding compound so that a molded part is formed, and opening the halves of the tool, reducing the circumference of the extension element in the insert to its size in the base state. In this method, the circumference of the extension element increases or decreases when the mold halves are closed or opened. Active enlargement or reduction of the extension element in the insert is not required. As a result, the insert can have a very simple structure and very small dimensions. Therefore, this method can be used to produce very small molded parts with a recess. The method preferably includes injection molding or die casting. In particular, molded parts made of plastic can be produced using this method. Such molded parts are used as plugs in cable assemblies, partly due to their electrically non-conductive properties. The closing step preferably comprises the following steps: bringing at least one half of the tool into contact with a first component of the insert, wherein the extension element can be moved with the first component in relation to a second component, moving one towards the other, further enclosing the insert, the first component with the extension element and the second component, inserting, further enclosing the insert, a projection in the second component in an opening in the extension element, so that the circumference of the extension element increases and the opening is closed by the projection. By placing one half of the tool in contact with the insert, the tool halves not only shape the external part but also enlarge or reduce the size of the extension element in the insert. Since the enlargement or reduction is performed using the tool halves, the insert can be manufactured more simply. This method can be used regardless of the size of the part being produced. Preferably, in the closing step, the second component moves against a pushing force in the direction of the first component, and the pushing force pushes the first component away from the second component in the tool-opening step. The directions of movement and pressure are reversible. This means that in the moving-to-each-other step, the first component can also move in the direction of the second component, or both components can move toward each other. This also applies analogously to the tool-opening step. The pushing force has the effect of returning the insert to its ground state, where the outer diameter of the extension element is smallest, once the insert closure or pressure on the components is released. The insert structure remains simple and is also suitable for very small inserts and / or tools. BRIEF DESCRIPTION OF THE FIGURES Furthermore, other advantages and features of the present invention are evident from the following description of preferred embodiments. The features described therein and above can be implemented individually or in combination, provided that the features do not contradict each other. The following description of preferred embodiments is made with reference to the accompanying drawings. It is shown: bebenn / zznz / B / YiAi Figure 1 shows a perspective view of one type of insert; Figure 2 shows a longitudinal side view of the insert modality shown in Figure 1; Figure 3 shows a plan view of one type of insert; Figure 4 shows a schematic representation of a tool mode with the insert mode of Figure 3; and Figure 5 shows the schematic representation of Figure 4 with injected molding mass to form a type of molded part with a recess. DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows one embodiment of an insert 1. The insert 1 has a first and a second component 10, 20, which are preferably arranged on a common axis 3. Along axis 3, the first and second components 10, 20 can be moved closer to and further from each other. Preferably, the second component 20 is fixed to axis 3 and the first component 10 is movable. In the illustrated embodiment, the first component 10 is depicted as a cylindrical component. Other shapes, such as a parallelepiped shape, are possible in alternative embodiments. The outside diameter DI of the first component 10 may be the same along axis 3 or may be designed differently at different sections. Preferably, the outside diameter DI of the first component 10 is smaller at a front end 14 that is far from the second component 20. In one embodiment, the outside diameter DI may gradually increase from the front end 14. In the illustrated embodiment, the first component 10 also has two radial projections 12, 13—a first and a second. The radial projections 12, 13 serve as supports for an extension element 30. To enable the extension element 30 to interact with the second component 20, the radial projections 12, 13 are arranged on one side of the first component 10 that faces the second component 20. In the illustrated embodiment, the radial projections 12, 13 extend radially outward from axis 3. The length to which the radial projections 12, 13 extend radially outward can vary. The radial projections 12, 13 can also be formed only in sections in the circumferential direction. Both radial projections 12, 13 are spaced apart to accommodate the extension element 30 between them. The first radial projection 12 can also be brought into direct contact with the second component 20 of insert 1 (see figure 4).The first radial projection 12 preferably has a passage opening 12a that allows a projection 22 of the second component 20 to pass through the first radial projection 12 in an opening 32 of the extension element 30. In the embodiment shown in Figure 1, the second component 20 is cylindrical. In alternative embodiments, the second component 20 may have other shapes, such as a parallelepiped. In particular, the cylinder may taper in the direction of the first component 10 to an outer diameter D3 of the first component 10. The second component 20 may be connected to other components on the opposite side from the first component 10. In particular, the second component 20 may rest against a contact surface 5. The contact surface 5 may support the second component 20 and, if the second component 20 is movable about axis 3, serve as a stop. The second component 20 has at least one projection 22 in the longitudinal X direction along axis 3 on a side facing the first component 10. The projection 22 is preferably wedge-shaped and tapers in the direction away from the second component 20. In particular, the projection 22 extends, preferably from axis 3, radially outward to an outer diameter D2 of the second component 20. In alternative embodiments, the projection 22 may also extend radially outward shorter or longer than the outer diameter D2 of the second component 20. In an alternative embodiment, more than one projection 22 may also be arranged on the second component 20. The projection 22 preferably has a flattened tip. Thus, the projection 22 can be butted against a surface, for example, the second radial projection 13 of the first component 10.The surface of the projection 22 is preferably smooth, so that when the projection 22 has been fully inserted into the opening 32 of the extension element 30, the opening 32 is tightly closed. Between the first and second components 10, 20, an extension element 30 is arranged. The extension element 30 preferably comprises an elastic component, for example, made of metal or plastic. In the embodiment shown in Figures 1 to 5, the extension element 30 is an extension ring. In alternative embodiments, the extension element 30 may also have other shapes that increase its circumference by introducing at least one element. One alternative embodiment is a rectangular extension element into which at least one, preferably four, protrusions are inserted, so that the circumference of the extension element increases on all four sides. In further alternative embodiments, the extension element may have a pentagonal, hexagonal, etc., geometry. The extension ring 30 shown in Figures 1 to 5 has at least one opening 32. Preferably, the opening cuts through the ring 30. In particular, the opening 32 has a shape that is complementary to the shape of the projection 22. A complementary shape means that when the projection 22 is fully inserted into the opening 32, it seals the opening tightly, with the volume of the opening 32 in the ground state being less than the volume of the projection 22. If the projection 22 is fully inserted into the opening 32, the opening 32 closes, and the circumference or outer diameter D3 of the extension element 30 increases by the increase in volume due to the insertion of the projection 22. Preferably, the opening 32 has a width B3 that narrows in the X direction away from the second component 20, i.e., decreases.The outer diameter D3 of the extension element 30 in a base state, i.e., without an inserted projection 22, preferably corresponds to a maximum outer diameter D3 of the first component 10 at at least one of the radial projections 12, 13 (see Figure 2 and Figure 3). Preferably, the extension element 30 also has at least one clamping means by which the extension element 30 can be loosely held in a position relative to the first component 10. The extension element 30 must be held loosely to allow its circumferential size to change freely. Furthermore, the extension element 30 must be held in a position that ensures the projection 22 of the second component 20 can engage with the opening 32 of the extension element 30. In one embodiment, the clamping means has a projection inside the extension element 30. The projection can be inserted or clamped into a corresponding recess in the first component 10, thereby holding the extension element 30 in place without tightening.By changing the circumference of the extension element 30, the protrusion of the clamping means can radially vary its engagement depth with the corresponding depth in the first component 10 while maintaining its predetermined position. In a preferred embodiment, the clamping means has a wedge-shaped protrusion inside the extension ring 30 that fits into a corresponding wedge-shaped recess in the first component 10. In alternative embodiments, other configurations of the clamping means are possible. Therefore, other shapes of protrusions and / or recesses can be used, for example, rounded shapes and / or multiple protrusions and recesses, or the recess can be located in the extension element 30 and the protrusion in the first component 10. Figure 3 shows one embodiment of insert 1 in a top view, in which the protrusion 22 and the opening 32 are clearly visible. Insert 1 is in the base state, i.e., the protrusion 22 is outside the opening 32. Preferably, a pushing element, such as a spring, causes insert 1 to be placed in the base state. Furthermore, the tip of the protrusion 22 is preferably located in the immediate vicinity of the opening 12a on the first radial protrusion 12. As a result, when the first component 10 is displaced a length B1 in the X direction relative to the second component 20, the protrusion 22 is fully inserted into the opening 32. The same applies when the second component 20 is moved in the opposite direction. The width B3 of the opening 32 preferably varies along the longitudinal X-axis. The profile of width B3 preferably corresponds to the profile of width B2 of the projection 22. As a result, the projection 22 fits snugly within the opening 32. In particular, the volume of the projection 22 is greater than the volume of the opening 32 in the base state. After the projection 22 is inserted into the opening 32, the volume of the space between the opposite surfaces of the extension element 30 in the opening 32 increases to the volume of the projection 22. At the same time, the opening 32 is closed by the projection 22. As a result, the circumference of the extension element 30 can be increased from a smaller circumference in the base state to a larger one in the extended state. The size of the circumferential change H can be predetermined, for example, by the width B3 of the opening in the base state and / or the width B2 of the projection 22.The change in circumference H determines the depth of a recess 52 that can be produced in a molded part 50. The depth of the recess 52 can be influenced by other structures. Figure 4 schematically shows one embodiment of a tool 40 without pre-filled molding compound. In the tool 40, at least two tool halves 41, 42 are closed. The first tool half 41 is preferably arranged on a nozzle side of the tool 40, on which at least one nozzle for introducing molten molding compound into the tool 40 may be arranged. The second tool half 42 is preferably arranged on an ejector side of the tool 40, on which ejectors for demolding or ejecting a molded part 50 may be arranged. In other embodiments, the arrangement of the tool halves 41, 42 may also be different. The insert 1 is preferably arranged on the second tool half 42 or on the ejector side.In alternative embodiments, insert 1 may be arranged in the first half of tool 41 or on the nozzle side, or insert 1 may consist of sections that are arranged partly on the ejector side and partly on the nozzle side and that are joined when insert 1 is surrounded by the tool halves 41, 42. The first tool half 41 has, in particular, an additional part 41a for internal shaping of the molded part 50 that can be produced. The additional part 41a may have any shape. In an alternative embodiment, the first tool half 41 is in direct contact with insert 1, in particular with the first component 10 of insert 1. In Figure 4, the extension element 30 is in the extended state. The transition of the extension element 30 from the base state to the extended state is described as follows: When at least two tool halves 41, 42 are closed, the insert 1 moves in direction XI toward the first tool half 41, 41a. The movement in direction XI is preferably carried out by means of the second tool half 42, at least until the insert 1, in particular its front end 14, abuts the first tool half 41, 41a. The insert 1, and in particular the second tool half 42, then moves further in direction XI, where the second component 20 is pressed in the direction of the first component 10, preferably against a pre-tensioning force. The pre-tensioning force is preferably provided by a spring or a similar component.As the movement continues, the projection 22 slides in direction XI within the opening 32 of the extension element 30, increasing the circumference of the extension element 30. Simultaneously, the projection 22 closes the opening 32. In the fully expanded state shown in Figure 4, the outer diameter D3 of the extension element 30 corresponds to the outer diameter D2 of the second component 20. The extension element 30 projects radially beyond the first and second radial projections 12, 13. This results in a notch 34 between the extension element 30 and the second component 20, at least in the region of the first radial projection 12. In alternative embodiments, the second component 20 can slide over the first radial projection 12 and form a notch 34 by chamfering its outer periphery.The notch 34 preferably extends circumferentially over at least 50%, more preferably over at least 75% of the circumference. The more the notch 34 extends in the circumferential direction, the larger the radial recess area. The free end of the projection 22 rests against the second radial projection 13 along the X-axis, the second radial projection 13 serving as a stop. The opening 32 is completely closed to prevent the entry of any molding compound. In particular, the second tool half 42 generates a compressive force on the insert 1 in the XI direction, such that a front surface of the second component 20 presses against the expansion element 30 and generates prestress. Due to the prestress, the molten material is prevented from penetrating the voids unintentionally. In an alternative embodiment, the extension element 30 may have a chamfer or recess, at least in sections in the circumferential direction, on one side facing the second component 20. At least one complementary chamfer or projection, arranged on the second component 20 where its front face is in contact with the extension element 30, may fit into this chamfer or recess. This is particularly possible when the second component 20 slides over the first radial projection 12. The mutually complementary chamfers are preferably wedge-shaped. Specifically, the area of ​​the extension element 30 facing the opening 32 expands radially. When engaged, the complementary chamfers support the alignment of the extension element 30 in the desired shape, particularly circular or round. Figure 5 shows how the molding compound, in particular the hot melt, is introduced into at least one recess 44 of the tool 40. At least two tool halves 41, 42 completely enclose the insert 1. The molding compound can be introduced by an injection process or a pressure injection process. Once the molding compound has hardened in the tool 40, at least two tool halves 41, 42 open so that the molded part 50 can be removed. In particular, the notch 34 forms an internal projection 54 on the molded part 50, such that the insert 1 with the extension element 30 in the extended state cannot be separated from at least two tool halves 41, 42. To release the insert 1 from the molded part 50, the extension element 30 must change from the extended state to the base state.The transition from the extended state to the ground state is described below: When at least two tool halves 41 and 42 are opened, the first component 10 moves in the XI direction along with the first tool half 41, preferably due to preload. In the process, the extension element 30 moves away from the projection 22, and the projection 22 moves away from the opening 32. The extension element 30 transitions from the extended state to its ground state, with the circumference or outer diameter D3 of the extension element 30 decreasing. When the extension element 30 is in the ground state, the extension element 30 and the internal projection 54 do not support each other when moving along the X-axis. The insert 1 then exits the molded part 50 in the X2 direction. This can be supported by an ejector. The molded part 50 produced is preferably made of plastic. In particular, molded part 50 is used as a connector for electrical lines in cable assembly. Specifically, molded part 50 is small in size, i.e., on the order of millimeters. The outside dimensions of molded part 50, or the outside diameter of a housing, are preferably less than 20 mm, more preferably less than 15 mm, and even more preferably less than 10 mm. The inside diameter of a recess cut into molded part 50 is preferably less than 12 mm. The depth of at least one recess is preferably less than 15%, more preferably less than 1%, and even more preferably less than 5% of the diameter of the extension element in its base state.In particular, the depth of a recess can be adjusted by means of a difference H, whereby the outside diameter of the extension element 30 increases in the extended state compared to the base state. The insert 1 preferably comprises several extension elements 30, which can be brought to an extended state, in particular one after the other or in parallel, so that a molded part 50 with several recesses 52 can be produced. REFERENCE LIST insert shafts contact surface first component frPfrenn / zznz / E / YiAi 12 first radial projection 13 second radial projection 14 front end 10 second component 22 projection 30 extension element 32 opening 34 notch 40 tool 41 first tool half 41st additional piece frPfrenn / zznz / E / YiAi 42 second half of tool 44 gap 50 molded part 52 recess interior projection

Claims

1. Insert for a tool (40) for producing molded parts with a recess, having: a first component; a second component separate from the first component and having a projection extending into the first component; an extension element disposed between the first and second components and preferably movable with the first component; and an opening in the extension element into which the projection of the second component can enter, wherein the outer circumference of the extension element is increased and the opening through the projection is closed.

2. Insert according to claim 1, wherein the first and / or second component has a maximum outside diameter of less than 15 mm, preferably less than 12 mm, more preferably less than 10 mm.

3. Insert according to claim 1 or 2, wherein the extension element is held between two radial projections of the first component.

4. Insert according to one of claims 1-3, wherein the first and / or second component has a cylindrical shape.

5. Insert according to any of claims 1-4, wherein the projection is wedge-shaped and tapers away from the second component.

6. Insert according to any of claims 1-5, wherein the extension element comprises an extension ring.

7. Insert according to any of claims 1-6, wherein the opening has a shape complementary to the projection so that the opening is closed with the inserted projection.

8. Insert according to any of claims 1-7, wherein the volume of the projection is greater than the volume of the opening in the base state.

9. Insert according to one of claims 1-8, wherein the extension element is held loosely in its alignment with respect to the first component by means of clamping means.

10. A tool for producing recessed molded parts, comprising: at least two tool halves; and an insert according to any of claims 1-9; wherein at least two tool halves enclose the insert in the closed state and form at least one recess, so that a molded part with at least one recess can be formed. frPfrenn / zznz / E / YiAi 11. Device for producing recessed molded parts having: at least one tool according to claim 10; and at least one nozzle configured to introduce molten molding compound, preferably under pressure, into the recesses of the tool.

12. A method for manufacturing recessed molded parts, preferably using a tool according to claim 10 and / or a device according to claim 11, wherein the method comprises the following steps: enclosing an insert with the aid of at least two tool halves, so as to form at least one recess, wherein the enclosure increases and surrounds the circumference of an extension element in the insert; injecting a molding compound into at least one recess; curing the molding compound to form a molded part; and opening the tool halves, reducing the circumference of the extension element in the insert to its base state size.

13. Method according to claim 12, wherein the method comprises an injection molding method or compression molding.

14. Method according to claim 12 or 13, wherein the encirclement step comprises the steps of: bringing at least one half of the tool into contact with a first component of the insert, wherein the extension element is movable with the first component relative to a second component; moving towards each other while further encircling the insert, the first component with the extension element and the second component; inserting, while further encircling the insert, a projection on the second component into an opening in the extension element, such that the circumference of the extension element increases and the opening is closed by the projection.

15. Method according to claim 14, wherein the second component moves in the direction of the first component against a pressure force in the approach stage between them, and in the step of opening the tool halves, the push force pushes the first component away from the second component.