The present disclosure relates generally to a molding tool. More particularly, but not exclusively, the present disclosure relates to an improved device, system, and method capable of producing a molded component with an undercut.
Whether it be for structural, functional, and/or aesthetic purposes, molded articles often require undercuts. An undercut is any indentation or protrusion in the shape of a molded article that prevents simple ejection of the component from a straight-pull mold. Undercuts are generally divided into two categories: external undercuts extending outwardly from an exterior of the article, and interior undercuts extending inwardly within an interior of the article. An exemplary external undercut is illustrated in
The exemplary methods by which undercuts are achieved typically impart movement of a component of the mold associated with the undercut in a direction transverse to the direction of the mold opening. For example, a side-action or side-pull mold includes an additional component that moves separately from the mold and withdraws (sideways) during mold opening to allow the molded article to be ejected (vertically). A simple side-action mold can include a pin that creates a hole within the component and moves transverse the direction of the opening of the mold. The extra component having independent movement increases the complexity of the mold as well as the molding machine.
Another exemplary method includes a slide mechanism comprising a portion of the molding surface that, during mold opening, moves angularly to provide clearance for the undercut to pass the molding surface. For example, U.S. Pat. No. 4,854,849 to Sudo discloses a mold having two inclined slide cores that move in both a direction parallel to the ejecting direction, and in a direction perpendicular to the same so as to permit the undercut of the molded article to clear the slide core. Another similar process is disclosed in U.S. Pat. No. 6,039,558 to Park et al. The use of slide mechanisms undesirably requires a considerable number of moving components and occupies considerable space within the mold. Further, should the design of the undercut change, the entire mold and/or molding operation must be redesigned or replaced. Still further, the increased complexity of the moving components provide for little error in the molding operation, increasing the likelihood of suboptimal molded articles or temporary failure of the molding operation. Therefore, a need exists in the art to provide an improved device, system and method that requires fewer moving components to improve consistency and reliability of molding operations.
Still another exemplary method for producing molded articles with undercuts uses collapsible cores. Prior to the advent of collapsible cores, molded components having threads were either “jumped” or unscrewed from the mold. If the material comprising the undercut is flexible enough, the mold can jump the threads of the article over counterposing threads of the mold. Another process utilizing elastically deformable material to produce undercuts is disclosed in U.S. Pat. No. 4,378,044 to Suchan. If jumping is not an option, an unscrewing machine built into the mold can unscrew the part from the core. Unscrewing molds are considered among the most complex of all molds, and are limited in their application to threads. The added complexity often limits the number of articles that could otherwise be molded with a single mold.
A collapsible core can provide undercuts by radially collapsing inward during mold closing and radially expanding outward during mold opening. One exemplary system is disclosed in U.S. Pat. No. 4,502,659 to Stephenson et al. The system incorporates a mold member with a socket-like head comprised of a plurality of segments each defining a portion of the mold cavity. During mold opening, the segments radially flare outward to provide clearance for the external undercut to be ejected from the mold. The advent of collapsible cores, including reverse collapsible cores and dovetail collapsible cores, advanced undercut molding in several respects; however, these devices and processes are associated with several shortcomings. For example, the tolerancing and fit between the segments are critical to producing flash-free molding (i.e., “flash” is the excess material attached to a molded product typically caused by the leakage of material between two surfaces of the mold). Further, collapsible cores are generally limited to cylindrical or radially symmetrical articles.
The aforementioned methods of producing articles with undercuts typically cannot be extended to increasingly complex shapes. Of particular interest to the present disclosure is for use in creating airflow diverter ducts. A set of exemplary vane like shapes are shown in
United States Patent Publication No. 2007/0210472 to D′Inca et al. discloses a method for molding an article with a composite that requires compressing a sheet of premixed composite between two mold halves. After compression, the method undesirably requires further processing to remove excess material. Further, since the reference is concerned only with manufacturing the vanes or the blades (of a turbine), an undercut is not of concern, and standard compressive molding operations can be utilized.
Therefore, a need in the art exists for a tool used in a molding operation that is capable of producing complex articles having undercuts. A further need exists in the art to produce such articles using composites with relative ease. The properties of the composite should be fully preserved. The tool should not require more than minimal excess materials such as flash be removed from the article after the molding operation.
A primary object, feature, and/or advantage of the present disclosure is to improve on or overcome the deficiencies in the art.
Another object, feature, and/or advantage of the present disclosure is to provide a tool or insert used in a molding operation capable of more efficiently producing complex articles having undercuts. The tool or insert is advantageously removable from within the molded component after the molding operation.
Still another object, feature, and/or advantage of the present disclosure is reusability of the insert after the molding operation. Contrary to molding operations in which the insert is melted or otherwise destroyed from within the molded component to reveal the undercut, the present disclosure contemplates removing the insert in a non-destructible manner. Such reusability minimizes expense and lead time in manufacturing.
Still yet another object, feature, and/or advantage of the present disclosure is a system and method capable of producing a variety of non-uniform component shapes. The shapes need not be symmetrical, radially symmetrical, or otherwise uniform. A plurality of pieces can be positioned in an assembled configuration to comprise the insert. The plurality of pieces each have a geometry to be removed from within the molded component, often sequentially, after the molding operation. The geometry of the pieces, and the means by which the pieces are interlocked results in an article having an undercut with minimal excess material such as flash.
Another object, feature, and/or advantage of the present disclosure includes modularity when utilizing a plurality of inserts. One or more of the inserts can be interconnected via a bottom tool structure to create increasingly complex articles using advanced composite materials. The bottom tool structure has simple geometry for easy cleaning, upkeep, and reuse. Further, the bottom tool structure advantageously includes protrusion, pins, or other means to locate, orient, position and/or secure each of the inserts to the structure.
Still another object, feature, and/or advantage of the present disclosure is to provide a design in which the insert can quickly be removed from the molded component. The base assembly can include a post member that is drafted for easy removal from within the insert. The removal of the post member generates a cavity into which at least one of the pieces can be moved or collapsed to initiate the sequential removal of the pieces, and thus the insert. A bore can extend through the post member and provide for improved supply and/or removal of heat from the insert during or after the molding operation. Further, a connecting member can be disposed within a countersink associated with the post member and removably secured to a cap. The configuration provides improved interlocking of the pieces to reduce flash.
Another object, feature, and/or advantage of the present disclosure includes the ability to incorporate the device and system into a compression molding operation using zone-based active tool heating and cooling using air to manage temperature of the mold tool surface via arrayed heating of the ram and/or base, forced air heating and cooling using multiple airstreams, and heat removal with exhaust routes. Together with the central bore configured to supply and/or remove heat from the insert during or after the molding operation, the temperature of the molded component can be controlled with increased precision. Such precision maintains the mechanical and other physical properties of the molded material, which is of utmost importance when using advance composites during fabrication of ducting used to divert airflow.
These and/or other objects, features, and advantages of the present disclosure will be apparent to those skilled in the art. The present disclosure is not to be limited to or by these objects, features and advantages. No single embodiment need provide each and every object, feature, or advantage.
According to at least one aspect of the present disclosure, an improved device for producing a molded component having an undercut is provided. The device includes an insert comprised of a plurality of separate pieces individually removable from the molded component. One of the plurality of separate pieces is collapsible or movable into the cavity within the insert for subsequent removal from the molded component. The cavity can be created by removal of a base assembly having a post member. The remaining pieces are iteratively or sequentially collapsible into the cavity for subsequent removal from the molded component. Each of the pieces can have a different geometry. The pieces can be metallic, ceramic, a combination thereof, or of any suitable material to the demands of the molding operation.
One exemplary material of the pieces can comprise P20 tool steel. In contemplating other materials such as aluminum, copper, and/or beryllium copper, the ideal material transfers heat quickly and absorbs very little. Therefore, a high thermal conductivity and low heat capacity is preferable. The thermal diffusivity (i.e., the ratio of conductivity to capacity) can also be considered in light of the softness and cost of the material. Thus, aluminum has suitable thermal diffusivity, but is inherently soft. Beryllium copper is a preferable material, but is expensive to fabricate the pieces. The present disclosure contemplates that the pieces can be constructed from beryllium copper, but also embedded with copper and/or aluminum as appropriate. Further, the present disclosure contemplates printing the pieces using three-dimensional printing technologies as commonly known in the art.
In addition to material selection, the mass and geometry of the pieces is critical to reducing cycle time. The present disclosure contemplates several means by which to optimize mass and geometry. In an exemplary embodiment, the pieces 38 can be hollow while ensuring suitable contact patch to the heat source. The hollowing can be achieved through through-holes or three-dimensional printing with an internal cavity. In at least some aspects of the present disclosure, the hollow pieces can include a material with high thermal conductivity, including but not limited to aluminum, copper and/or beryllium copper.
According to at least one aspect of the present disclosure, a system for producing a molded component includes an insert configured to be removable from the molded component and having a plurality of pieces configured to be positioned into an assembled configuration. Each of the pieces is comprised of a plurality of contact surfaces each between at least two of the plurality of pieces in the assembled configuration, an outer boundary extending between the contact surfaces, an inner boundary extending between the contact surfaces and opposite the outer boundary, and an upper boundary opposite a lower boundary. The upper boundary and the lower boundary are separated by the outer boundary, the inner boundary, and the contact surfaces. The inner boundaries of the pieces collectively define a cavity within the insert in the assembled configuration. The outer boundaries of the pieces collectively define a periphery of the insert in the assembled configuration. The molded component is associated with the periphery of the insert. The pieces can be assembled such that each of the pieces is adjacent to exactly two other pieces.
Due to the relative dimensions of the insert and the molded component, the insert can be prevented from being wholly inserted or removed from the molded component in the assembled configuration. However, at least one of the pieces is removable from the molded component through the cavity. More particularly, the inner boundary of at least one of the pieces is sized to be slidable, movable, or collapsible into the cavity such that the piece is removable from the molded component through the cavity. The pieces can be configured to be sequentially removed from the molded component.
A base member is configured to be removably positionable adjacent the lower boundary of the pieces in the assembled configuration, and a post member extends upwardly from the base member. The post member is configured to be removably positioned within the cavity in the assembled configuration. The base member and the post member are removed from the insert prior to subsequent and/or sequential removal of the plurality of pieces from the molded component.
The system can further include an upper retention feature associated with the upper boundary of each of the pieces. The upper retention features collectively define an upper retention member of the insert. A counterposing retention member can be configured to removably connect with the upper retention member to interlock the plurality of pieces in the assembled configuration. The system can further include a lower retention feature associated with the lower boundary of each of the pieces. The lower retention features collectively define a lower retention member of the insert. A base retention feature can be associated with the base member and configured to removably connect with the lower retention member to interlock the plurality of pieces in the assembled configuration.
A plurality of inserts can be arranged into an array interconnected by a bottom tool structure. The molded component can include a matrix of cells. Each of the inserts is associated with one of the cells. The bottom tool structure can be operatively connected to a compression molding machine. In one embodiment, the compression molding machine further comprises a ram and a base that provide for active forced air heating and cooling of the molded component.
According to at least one aspect of the present disclosure, a mold system can include a mold and an array of inserts configured to be removably inserted into the mold. Each of the inserts comprises a plurality of pieces configured to be assembled, a cavity within the insert at least partially bounded by the pieces. The mold and the array of inserts produce a molded component having a plurality of cells each associated with an undercut. The undercuts of the molded component prevent removal of the inserts from the molded component. At least one of the pieces associated with each of the inserts is slidable, movable, or collapsible into the cavity so as to be removable from the molded component. The relative dimensions between the inserts and the undercuts can require the pieces of each of the inserts be removed through one of the plurality of cells of the molded component in sequence.
A post member extends through the cavity, is connected to a base member, and removable from within each of the inserts. The pieces, the base member, and the post member are configured to interlock to comprise each of the inserts. During removal, the post member is removed prior to removal of the pieces associated with the same insert. A bottom tool member can connect all of the inserts in the array. In an exemplary embodiment, the plurality of cells of the molded component are arranged in a rectangular matrix.
According to at least one aspect of the present disclosure, a method for molding items is provided. The method includes the step of performing a molding operation to produce a molded component. An insert having a plurality of pieces is removed from the molded component. To do so, a post member extending through the insert is removed, thereby creating a cavity. A first piece is moved into the cavity of the insert, thereby making the first piece removable from the molded component. The first piece is removed from the molded component, thereby creating an updated cavity. A second piece is moved into the updated cavity, thereby making the second piece removable from the molded component. The second is removed from the molded component. The method can be iteratively repeated for each of the pieces of the insert.
The method can further comprise the step of removing a retention cap configured to interlock the plurality of pieces. The method can further include the step of trimming a crown portion of the molded component to expose a plurality of cells extending through the molded component. Further, an array of the inserts can be positioned on a bottom tool structure via pins associated with the bottom tool structure and corresponding structures associated with the insert.
Illustrated embodiments of the disclosure are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein, and where:
In molding operations configured to produce mold components with an undercut, such as the component 10 illustrated in
In embodiments where a plurality of inserts 26 are incorporated, each of the plurality of inserts 26 is configured to interface to a bottom tool structure 34. The bottom tool structure 34 is generally a plate-like structure with geometries 36 configured to position, orient, and/or secure each of the inserts 26. In one exemplary embodiment illustrated in
As commonly known in compression molding and as disclosed herein, the molding operation is generally associated with a ram and a base. In embodiments wherein one or more inserts 26 are operably connected to the bottom tool structure 34, the bottom tool structure 34 is removably secured to the base of the compression molding machine.
One of the primary objects and advantages of the present disclosure includes the insert 26 being removable from the molded component 30 having an undercut. To achieve this object and advantage, the insert 26 is comprised of a plurality of pieces 38. Referring to
Each of the plurality of pieces 38 is comprised of a plurality of contact surfaces 40, an outer boundary 42, an inner boundary 44, an upper boundary 46, and a lower boundary 48. The contact surfaces 40 are each between at least two of the plurality of pieces 38 in the assembled configuration. With references to
The molded component is associated with the periphery 58 of the insert 26. More particularly, when the insert 26 is disposed within a mold of the molding operation, the material(s) are molded and compressed about the periphery 58 of the insert 26 such that the molded component generally is shaped to periphery 58 and the mold.
Referring to
One exemplary base assembly 66 is illustrated in
With reference to
Thus, in the illustrated embodiment of
To further interlock the plurality of pieces 38 together, the post member 70 of the base assembly 66 can include a bore 84 extending through the post member 72. With reference to
The method by which the insert 26 is removed from a molded component will now be explained. One or more inserts in the assembled configuration are inserted within a mold. As disclosed, a singular insert 26 can be inserted into a mold 62, similar to the embodiment illustrated in
The molding operation is performed, in which material is heated and compressed via a ram over the cap(s) 82 of the one or more inserts 26. The cap(s) 82 can be dome-shaped so as to facilitate material flow in between the insert 26 and the mold 62 and/or between each of the inserts 26. The dome shape can further minimize material usage, which advantageously provides for lower material costs. The material is heated and compressed in between the insert 26 and the mold 62 and/or between each of the inserts 26. The cap 82 can be designed to advantageously direct flow of the heated material to control knit lines and/or overall mold flow. For example, controlling overall mold flow can advantageously orient and/or align fibers within the composite matrix, which can enhance mechanical properties of the fiber-reinforced composite.
After the molding operation is complete, the one or more inserts 26 and the molded component are removed from the mold. In certain embodiments, the bottom tool member 34 is used, thereby resulting in the molded component with the one or more inserts 26 disposed within the same. As previously disclosed, if an undercut is associated with the molded component, a typical mold insert cannot be removed from the same.
Referring to
In an alternative exemplary embodiment, a post member is not required. In such an embodiment, at least one of the pieces will not be associated with an undercut such that it can be slidably removed from the molded component. Consider the insert 26 of
Referring now to
The size and shape of the cavity 56 and the pieces 38 are such that at least one of the pieces 38 can slidably move into the cavity 56. With reference to
Next, Piece C is moved within the further updated cavity 100 in a direction of arrow 102 such that the outer boundary 44 of Piece C is within the narrowest portion 92 of the molded component 60, thereby making Piece C removable from the molded component 60, as illustrated in
In some embodiments, after the final piece 38 is removed, the cap 82 remains within the molded component, as illustrated in
From the above method of removing the insert 26 from the molded component 60, it is readily appreciated that the primary objects and advantages of the present disclosure are achieved by providing an insert 26 having a plurality of separate pieces 38 individually removable from a cavity 56/96/100/104 within the insert 26. In doing so, each one of the plurality of separate pieces 38 is slidable, movable, or collapsible or movable into the cavity 56/96/100/104 prior to subsequent removal. While the exemplary embodiment includes four pieces, any number of pieces can be utilized without deviating from the objects of the present disclosure. The present disclosure contemplates two, three, five, six, seven or greater pieces can be designed to be iterative or sequentially movable within a cavity then subsequently removed from the molded component.
Furthermore, in the exemplary embodiment, Pieces A and B and Pieces C and D were substantially the same. Based on such design, while the disclosure indicates Piece B is moved into the cavity 56 first, followed by Piece A, this need not be the case. In the exemplary embodiment described, Piece A could have been moved into the cavity 56 first. Based on relative dimensions, however, Pieces C and D must remain within the molded component until after both Pieces A and B were removed, after which either Piece C or Piece D could be removed followed by the other. In such a respect, there is a sequential nature to the order in which the pieces must be removed: (i) Piece A or B, (ii) the remaining of Piece A or B, (iii) Piece C or D, and (iv) the remaining of Piece C or D. Furthermore, it can be readily appreciated that the base assembly 66, and more particularly the post member 70, must be removed prior to removal of the plurality of pieces 38 associated with the same insert 26.
While the exemplary embodiment discloses symmetry such that Pieces A and B and Pieces C and D are substantially the same geometry, the present disclosure contemplates that each piece could have a different geometry. In such embodiments, the sequential order in which the pieces must be removed could be more constrained. Together with embodiments in which greater than four pieces are utilized, the insert could become increasingly complex. Yet utilizing greater than four pieces, especially smaller pieces, can provide for molded components with undercuts of increasingly complex shape.
The present disclosure emphasizes that the present invention can be used to any periphery having an undercut, with the molded component 60 being but one exemplary embodiment. Thus, while the disclosed mold component 60 is a rectangular prism including a periphery 58 comprised of four arcuate surfaces, not all sides need to include undercuts. In a preferred embodiment, two opposing sides of the insert can be substantially planar, and the two remaining opposing sides of the insert can be arcuate and parallel. Each of the inserts being an arcuate structure results in a geometry similar to vanes 16 of the component 10 illustrated in
In the context of producing airflow diverter ducts or similar molded components having a matrix of cells 32 (e.g., 30 of
In a preferred embodiment, the interconnected array 28 is connected to the bottom tool structure 34 for use in a compression molding operation. One exemplary compression molding operation is illustrated in
Referring to
The disclosure is not to be limited to the particular embodiments described herein. In particular, the disclosure contemplates numerous variations for the improved removable insert, system, and method capable of producing a molded component with an undercut. For example, the present disclosure envisions the removal of each of the pieces of an insert is automated by robotics. For another example, the inner boundary 44 of the pieces 38 need not be planar, but could be arcuate, tiered in a staircase configuration, and the like. In such an embodiment, the post member 70 would have a counterposing design and drafted for removal from the insert 26 to create the cavity 56. The foregoing description has been presented for purposes of illustration and description. It is not intended to be an exhaustive list or limit any of the disclosure to the precise forms disclosed. It is contemplated that other alternatives or exemplary aspects are considered included in the disclosure. The description is merely examples of embodiments, processes or methods of the disclosure. It is understood that any other modifications, substitutions, and/or additions can be made, which are within the intended spirit and scope of the disclosure. For the foregoing, it can be seen that the disclosure accomplishes at least all that is intended.
The previous detailed description is of a small number of embodiments for implementing the disclosure and is not intended to be limiting in scope. The following claims set forth a number of the embodiments of the disclosure with greater particularity.