Method and system for dispensing spray wax and break strip extrusion material - Patents.com

Abstract

The present disclosure relates to methods and systems provided that include a thermal fuser having a heated hose connected to a heated dispensing gun. The present disclosure also provides methods and systems for automating the creation and joining of break strips.

Description

[Technical field]

[0001] Priority and Incorporation by Reference This application claims priority to U.S. Provisional Patent Application No. 63 / 046518, filed June 30, 2020, and U.S. Provisional Patent Application No. 63 / 049475, filed July 8, 2020, the disclosures of each of which are incorporated by reference in their entireties herein.

[0002] The present disclosure relates to methods and apparatus for use in the automated construction and / or preparation of wax molds usable in lost wax casting. [Background technology]

[0003] Casting metal products using the lost-wax process is an ancient and well-known method that is still widely used in fields including jewelry making, dentistry, art, industry, etc. In industrial applications, lost-wax casting is also known as investment casting, and is commonly used in engineering and manufacturing applications to create precision metal parts.

[0004] Traditionally, lost wax casting is a manual process, where the wax mold is assembled by hand, which is laborious, time-consuming, and allows for a large degree of variability in part placement. Once the worker has gathered all the necessary parts, they begin the assembly process. Using templates, branding irons, melted wax, and other methods, they assemble the multiple parts of the wax mold according to the working standards of the specific wax mold. During the assembly process, the worker must place each part in its specific location, customize the multiple parts to fit by trimming or melting them to size, and then place them in the desired location.

[0005] To verify that each part in the wax mold meets the quality requirements of the finished product, the wax mold is then moved to an inspection station where a worker manually verifies the positioning of each part and its supporting structures by sliding a template over each part / structure, one at a time, and rotating the assembled wax mold to verify each position.

[0006] The lost-wax casting process includes the steps shown in Figure 1: pouring wax, assembling the pattern, making the shell, dewaxing, pouring metal, and removing the shell to obtain the finished product. In this process, a wax mold is immersed in a ceramic slurry that hardens to form a ceramic shell (shelling). The wax mold is created by assembling wax pieces into the shape of a weldment. These pieces are created by injection molding, 3D printing, or other (usually additive) manufacturing methods. These solid wax pieces are then welded (fused) together by hand using a hot iron, melted liquid wax, or a combination of both.

[0007] The shell is then heated and the wax removed (dewaxing). The next step in the process is usually metal injection, although sometimes additional preparation of the shell (shell preparation) may need to be done prior to metal injection, which may involve the deliberate crushing or removal of parts of the ceramic shell.

[0008] During shell preparation, the shell can crack in an unexpected manner, which can lead to damage or complete loss of the shell. To help prevent this problem, break strip features are added to the pattern assembly. Break strips are bar, ring, or zigzag shaped features that aid in shell preparation and provide a fault line in the shell that prevents cracks from propagating to undesired areas of the shell.

[0009] Break strips are components that are typically injection molded and manually assembled into the pattern assembly, which requires additional time, personnel, processes, tools, and materials.

[0010] Attempts to automate this process require precise precision of its components and each step of the process, including not only the placement and welding of parts in the wax mold, but also the measurement and inspection of the wax mold.

[0011] Wax molds constructed for the lost wax process typically use molten wax and a dropper to dispense the wax onto or between the components and / or substrates. The wax is melted using a hot plate and tin pan or hot pot by setting the temperature of the hot plate or hot pot to the melting point temperature of the particular wax being used.

[0012] The process requires the worker to insert a dropper into molten wax, draw the wax up into the dropper, and then manually dispense the wax onto the desired surface by squeezing the dropper's rubber bulb to release the desired amount of wax (Figure 6).

[0013] The process of using a dropper and molten wax is not viable for an automated wax mold assembly process. Having an operator manually draw up and dispense wax using a dropper does not fit within the scheme of an automated wax mold assembly cell process. Additionally, applying wax to components and substrates manually introduces significant operator-to-operator and sequence-to-sequence variability.

[0014] Automating the break strip requires an extra component (the break strip) that must be created by injection molding, cutting from a longer piece, or other methods. Creating the break strip itself requires additional costs (time, personnel, process, tooling, materials, and handling). Also, the break strip must be manually attached to the pattern assembly.

[0015] The small size, length and flexibility of the break strips make them difficult to handle with automation, and it is not feasible to automate the dropper welding process. Summary of the Invention

[0016] According to an aspect of the present disclosure, a method and system is provided that includes a thermal melter having a heated hose connected to a heated dispensing gun.

[0017] According to another aspect of the present disclosure, a method and system are provided for automating the creation and bonding of break strips to a shell, pattern, or pattern assembly plate.

[0018] These and other embodiments, objects, features, and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, and the appended claims. [Brief description of the drawings]

[0019] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate various embodiments, objects, features, and advantages of the present disclosure.

[0020] [Figure 1] FIG. 1 shows a process diagram of the investment casting method. [Diagram 2] FIG. 2 shows a thermal melter. [Diagram 3] FIG. 3 shows a heated hose. [Figure 4]FIG. 4 shows a heated dispensing gun. [Diagram 5] FIG. 5 shows the components of the system. [Figure 6] FIG. 6 shows the manual application of break strips to a pattern assembly plate. [Figure 7] FIG. 7 shows the automated application of break strips to a pattern assembly plate.

[0021] Throughout the figures, the same reference numerals and characters are used for like features, elements, components or portions of the illustrated embodiments, unless otherwise stated. Moreover, while the present disclosure will now be described in detail with reference to the figures, it is done so in connection with the exemplary embodiments. It is intended that changes and modifications can be made to the exemplary embodiments described without departing from the true scope and spirit of this disclosure, as defined by the appended claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the following exemplary embodiments are merely examples for implementing the present disclosure, and may be appropriately modified or changed depending on the individual configuration of an apparatus to which the present disclosure is applied and various conditions. Thus, the present disclosure is by no means limited to the following exemplary embodiments.

[0023] This disclosure has some exemplary embodiments and relies on patents, patent applications, and other references for details known to those skilled in the art. Thus, when a patent, patent application, or other reference is cited or repeated in this specification, it should be understood that it is incorporated by reference in its entirety for all purposes, not just the propositions set forth herein.

[0024] In one embodiment of the present disclosure, a method of dispensing spray wax is provided, comprising providing a wax dispensing system including a thermal melter and a heated dispensing gun, the thermal melter and the heated dispensing gun being connected via a heated hose, opening a solenoid valve to initiate a flow of wax from the thermal melt, dispensing wax from the heated dispensing gun, and closing the solenoid valve to stop the flow of wax.

[0025] In certain embodiments, the heated dispensing gun is removably mounted to a distal end of the robotic arm. A programmable logic controller (PLC) can be configured to open and close the solenoid valve, where the PLC opens the solenoid valve for a predetermined amount of time such that the same amount of wax is dispensed over multiple dispenses.

[0026] In other embodiments, a heated dispensing gun includes a nozzle with a retracted and extended needle, which can provide binary control of wax dispensing: retracting the needle stops wax dispensing, and wax dispensing occurs only when the needle is extended.

[0027] In a further embodiment, the molten wax maintains approximately the same temperature while traveling from the thermal melter through the heated hose to the heated dispensing gun.

[0028] According to one embodiment of the present disclosure, a system for dispensing spray wax is provided that includes a thermal melter and a heated dispensing gun connected to each other via a heated hose, a solenoid valve for starting / stopping the flow of wax from the thermal melter that is opened and closed by a programmable logic controller (PLC), and a proportional-integral-derivative (PID) controller configured to control the temperature of the thermal melter, the heated hose, and the heated dispensing gun.

[0029] In certain embodiments, the system is used in combination with an automated robotic system, and the heated dispense gun of the system can be mounted (removably or not) on the distal end of a robotic arm that can be in communication with a controller that directs movement of the arm and control of the heated dispense gun.

[0030] In another embodiment, a system is provided that includes a hot wax spray applicator mounted to a distal end of a robotic arm, which in certain embodiments may be a heated dispensing gun.

[0031] As shown in FIG. 2, an exemplary heat melt machine typically used for heat melt wax applications is depicted. The exemplary heat melt machine includes an electrical component housing door 1, a control panel 2, a tank lid 3, a side panel 4, a tank 5, a hose / gun receptacle 6, a tank isolation valve 7, a manifold 8, a pressure control valve 9, a filter 10, a pump 11, fittings 12, and a motor 13. It is within the scope of this disclosure that other similar or different model melting machines can be used within the scope of this disclosure. To allow for automation of wax dispensing, the wax melt machine is configured to melt and control the appropriate temperature of the wax to a liquefied state. In one embodiment, the machine is fitted with a proportional integral derivative (PID) control to control the temperature of the wax in the tank 5 along with a heated hose 14 (shown in FIG. 3) and a heated dispensing gun 15. The use of the heated hose 14 and heated dispensing gun 15 allows for better control of the temperature of the melted wax and provides a more consistent temperature. Pump 11 controls the flow of wax as required through heated hose 14 and heated dispensing gun 15 .

[0032] The heated dispensing gun 15 shown in FIG. 4 is operated by a programmable logic controller (PLC) 16. A solenoid valve may be opened and closed to start and stop the flow of wax from the melter through the heated hose 14 and the heated dispensing gun 15. The heated dispensing gun 15 may be operated and its position controlled by an end-of-arm attachment to a robot in an automated system, and in some embodiments, the robot may be a six-axis robot. An exemplary system according to the present disclosure is provided in FIG. 5, which may include a melter in fluid communication with the heated hose 14, which is further in fluid communication with the heated dispensing gun 15. The heated dispensing gun 15 may then be used in an automated system to apply molten wax during the process of preparing a wax mold for use in investment casting.

[0033] In one embodiment, the system including a heated hose and a heated dispensing gun and the method for dispensing wax using the same provide significant advantages when used in preparing molds for use in lost wax molding. The disclosed system and method provide greater repeatability and accuracy of the placement of molten wax on the component and / or mold substrate. In one embodiment, PLC control ensures that the same amount of wax is dispensed each time the solenoid is actuated, improving repeatability and reducing variability between successive uses. Improved repeatability of the wax placement position is provided by the use of the disclosed system and method with an automated system with robotic control, such as a 6-axis robotic control.

[0034] In embodiments of the present disclosure, there is superior temperature control of the wax via PID temperature control compared to that found in uncontrolled systems such as when wax is applied manually via a dropper. In certain embodiments, the heated dispensing gun 15 has improved on / off control with needle extension and retraction to the nozzle tip, which provides binary control of wax dispensing without dripping or stringing of wax, which is an improvement over off-the-shelf wax dispensing devices.

[0035] In a further embodiment, as shown in FIG. 7, the system and method of dispensing wax via a heated dispensing gun and heated hose can be utilized to improve systems and processes for use in lost wax casting, such as automated extrusion of break strip.

[0036] In a further embodiment, a method for creating a break strip is provided that comprises providing a hot wax spray applicator and moving the hot wax spray applicator across a surface for a predetermined time while extruding wax at predetermined locations to create the break strip.

[0037] In certain embodiments, the method includes providing an automated system, where the hot wax spray applicator can be mounted on a distal end of a robotic arm that can be in communication with a controller that directs movement of the arm and control of the hot wax spray applicator. Such a controller can cause the robotic arm to activate the hot wax spray applicator to extrude wax. Furthermore, the robotic arm can manipulate the hot wax spray applicator to extrude wax in a predetermined pattern at predetermined locations, thereby creating the break strip.

[0038] In other embodiments, the system and method provides a controlled temperature for the wax, where the temperature of the wax is approximately the same from the tank through the heated hose and into the hot wax spray applicator. The disclosed system and method further provides controlled pressure of the wax during extrusion. In certain embodiments, the hot wax spray applicator is a heated dispensing gun.

[0039] As shown in FIG. 6, in traditional usage, the break strips are extruded and then separately attached to the desired location, for example, by applying molten wax with a dropper. In one embodiment, the disclosed system and method includes a hot wax spray applicator, such as a heated dispensing gun, that is moved across a desired surface, including the surface of a pattern assembly plate, to extrude break strips of a desired shape, size, and location. In other embodiments, the system and method for break strip extrusion allows for automated control of the wax temperature and pressure, along with automated positioning of the wax extrusion. In such an embodiment, the hot wax spray applicator is controlled by an automated system, including being operated and its position controlled by an end-of-arm attachment to a robot in the automated system, in some embodiments, the robot may be a six-axis robot. In other embodiments, a wax dispensing system and method using the same as described above to dispense the break strips can be implemented.

[0040] It is an aspect of the presently disclosed system and method that it is not necessary to create a separate part that must be welded to the pattern assembly, thereby allowing the present system and method to avoid all of the associated labor and tooling costs inherent in the manual break strip extrusion process, although material is still required. The system and method is easily automated and can be incorporated into a fully automated mold assembly process.

[0041] The embodiments of the present disclosure may be implemented by a computer of a system or apparatus that reads and executes computer-executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more fully referred to as a "non-transitory computer-readable storage medium") to perform the functions of one or more of the above-described embodiments, and / or by a computer of a system or apparatus that includes one or more circuits (e.g., application specific integrated circuits (ASICs)) to perform the functions of one or more of the above-described embodiments. The embodiments of the present disclosure may also be implemented by a method performed by a computer of a system or apparatus, for example, by reading and executing computer-executable instructions from a storage medium to perform the functions of one or more of the above-described embodiments, and / or by controlling one or more circuits to perform the functions of one or more of the above-described embodiments. The computer may include one or more processors (e.g., central processing unit (CPU), microprocessing unit (MPU)) and may include a separate computer or a network of separate processors for reading and executing the computer-executable instructions. The computer-executable instructions may be provided to the computer, for example, from a network or a storage medium. The storage medium may include, for example, one or more hard disks, random access memory (RAM), read only memory (ROM), storage of a distributed computing system, optical disks (compact disks (CDs), digital versatile disks (DVDs), Blu-ray Disc (BD)™, etc.), flash memory devices, memory cards, etc. The I / O interface may be used to provide a communications interface to input / output devices, which may include keyboards, displays, mice, touch screens, touchless interfaces (e.g., gesture recognizers), printing devices, light pens, optical storage devices, scanners, microphones, cameras, drives, communications cables, and networks (either wired or wireless), etc.

[0042] definition In the description, specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. In other instances, well-known methods, procedures, components, and circuits have not been described in detail to avoid unnecessarily lengthening the present disclosure.

[0043] As used herein, when an element or portion is referred to as being "on," "on," "connected," or "coupled" to another element or portion, it is understood that it may be "on," "on," "connected," or "coupled" directly to that other element or portion, or there may be intervening elements or portions. In contrast, when an element is referred to as being "directly on," "directly connected," or "directly coupled" to another element or portion, there are no intervening elements or portions. When the term "and / or" is used, it includes any and all combinations of one or more of the associated listed items, if any.

[0044] Spatially relative terms such as "under," "beneath," "below," "lower," "above," "upper," "proximal," "distal," and the like may be used herein for ease of description in describing the relationship of an element or feature shown in the various figures to another element or feature(s). However, it should be understood that these spatially relative terms are intended to encompass various orientations of the device in use or operation in addition to the orientation shown in the figures. For example, if the device in the figures were inverted, elements described as "below" or "beneath" other elements or features would be oriented "above" those other elements or features. Thus, a relative spatial term such as "below" can encompass both an orientation above and below. The device may be otherwise oriented (rotated 90 degrees or to other orientations) and the spatially relative descriptors used herein should be interpreted accordingly. Similarly, the relative spatial terms "proximal" and "distal" may be interchangeable where applicable.

[0045] As used herein, the term "about" means, for example, within 10%, within 5%, or less. In some embodiments, the term "about" can also mean within the error of measurement.

[0046] In this specification, terms such as first, second, third, etc. may be used to describe various elements, components, regions, portions, and / or sections. It should be understood that these elements, components, regions, portions, and / or sections are not limited by these terms. These terms are merely used to distinguish one element, component, region, portion, or section from another region, portion, or section. Thus, a first element, component, region, portion, or section discussed below can also be referred to as a second element, component, region, portion, or section without departing from the teachings of this specification.

[0047] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting. The use of the terms "a," "an," "the," and similar referents in the context of describing the present disclosure (especially in the context of the appended claims) shall be construed to include both the singular and the plural, unless otherwise indicated herein or otherwise clear from the context. The terms "comprising," "having," "includes," "including," and "containing" shall be construed as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise stated. In particular, when these terms are used herein, they specify the presence of the described features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof not expressly stated. The description of ranges of values ​​herein is merely intended to serve as a shorthand notation for referring individually to each separate value falling within the range, and each separate value is incorporated herein as if it were individually set forth herein, unless otherwise indicated herein. For example, if a range of 10-15 is disclosed, 11, 12, 13, and 14 are also disclosed. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clear from the context. The use of any examples or exemplary language (e.g., "such as") provided herein is intended merely to make the disclosure more clear, and does not limit the scope of the disclosure unless otherwise stated in the claims. No language in this specification should be construed as indicating that any element not recited in the claims is essential to the practice of the disclosure.

[0048] It should be understood that the methods and configurations of the present disclosure can be incorporated in the form of various embodiments, only a few of which are disclosed herein. Variations of those embodiments will be apparent to those skilled in the art upon reading the above description. The inventors anticipate that those skilled in the art will adopt such variations as necessary, and intend that the present disclosure be practiced otherwise than as specifically described herein. Accordingly, the present disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, the present disclosure encompasses any combination of the above-described elements in all possible variations thereof, unless otherwise indicated herein or otherwise apparent from the context.

Claims

1. 1. A method for dispensing spray wax for use in lost wax molding, comprising: providing a wax dispensing system comprising a heat melter and a heated dispensing gun connected together via a heated hose; opening a solenoid valve to initiate wax flow from said thermal melter; dispensing the wax from the heated dispensing gun; closing the solenoid valve to stop the flow of wax; Equipped with The thermal melter is configured to melt the wax to a liquefied state; The method wherein the heated hose and the heated dispensing gun are heated such that the temperature of the wax is the same from the thermal melt through the heated hose to the heated dispensing gun.

2. The method of claim 1 , wherein the heated dispensing gun is removably mounted to a distal end of a robotic arm.

3. The method of claim 1 , wherein a programmable logic controller (PLC) is configured to open and close the solenoid valve.

4. 4. The method of claim 3, wherein the PLC opens the solenoid valve for a predetermined amount of time such that the same amount of wax is dispensed over multiple dispenses.

5. The method of claim 1 , wherein the heated dispensing gun comprises a nozzle having an extending and retracting needle.

6. 2. The method of claim 1, wherein the heated dispensing gun has a nozzle configured to dispense wax when a needle extends from a tip of the nozzle and to stop dispensing wax when the needle retracts from the tip of the nozzle.

7. 10. The method of claim 1, wherein the molten wax maintains approximately the same temperature while traveling from the thermal melt through the heated hose to the heated dispensing gun.

8. 1. A spray wax dispensing system comprising: a thermal melter configured to melt the wax to a liquefied state; a heated dispensing gun connected to the thermal melt via a heated hose; a solenoid valve that starts and stops the flow of wax from the thermal melter, the solenoid valve being triggered by a programmable logic controller (PLC) to open and close; a proportional-integral-derivative (PID) controller configured to control temperatures of the thermal melter, the heated hose, and the heated dispensing gun such that the temperature of the wax is the same from the thermal melter through the heated hose to the heated dispensing gun; A system comprising:

9. The system of claim 8 , wherein the system is used in combination with an automated robotic system.

10. 10. The system of claim 9, wherein the heated dispensing gun is removably mounted to a distal end of a robotic arm.

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