The present invention relates to a cooling assembly and method for manufacturing same.
Standard injection molding arrangements and processes require long cycle times and have additional costs associated with secondary machinery and/or tooling. Generally, a part is molded within a cavity mold and then demolded. In one known attempt to improve prior standard methods the end of arm tooling is modified by using porous aluminum in order to try to demold injection molded parts more quickly. However, this attempt has been disadvantageous. Manufacturing of such a cooling tool for demolding is time consuming and extremely expensive.
Accordingly, a cooling assembly and method for making same is desired, which has integrated structural cooling features that reduce cycle time and also reduces tooling costs while increasing the speed of manufacturing of such cooling tooling.
The present invention is directed to a cooling apparatus and a process operable for making same. There is provided a cooling apparatus having a cooling box mounted directly to a demolding robot. The cooling box has integrated cooling and attachment features. There is provided a net fit between the cooling box, and the cavity inside of the molded part being manufactured, to allow the cooling cycle time to be reduced as the molded part finishes the cooling cycle in the end of arm tooling while the mold is closed and starts making the next molded part. At least one portion of the cooling box includes a three dimensional (3D) printed portion that is partly solid and partly micro porous. A vacuum is pulled through the walls of the cooling box allowing for part demolding and/or fixturing while cooling.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
There is provided an end of arm cooling fixture that is microporous and allows for reduced injection molding cycle time, e.g., at least 20% reduction in cycle time, low cost tooling, and which is a three-dimensional (3D) printable part nest that is at least 60% porous stainless steel.
Referring generally to
The solid portion, generally shown at 22, of the housing 16 is integrally formed with the tool nest portion 20, and is operably mounted directly to a demolding robot, generally shown at 24, e.g., attachable to the robot using integrated robot attachment features such as threaded screw bosses, mounting plates, support ribs. The demolding robot 24 is connected to the rear of the housing 16 opposite the front where the tool nest 20 is located. Alternatively, the demolding robot 24 is connectable to the top or bottom of the cooling apparatus 10 depending on particular applications and working cell parameters.
The tool nest portion 20 has an integrally formed at least one curved surface portion 26 and at least one flange portion 30 operably configured to net fit to the molded part 14 to be demolded. At least one lip 34 extends from the flange portion 30 to contact the outer edge of the molded part 14 and is disposed between this outer edge and the solid portion 22 of the housing 16. In a preferred embodiment, the curved surface 26 of the tool nest portion 20 substantially forms a hemisphere-shape or semicircle-like cross-section protruding into the internal chamber 18 and forms an open area to laterally receive the molded part 14 therein. When loaded into the cooling box 12, the curve surface 26 generally follows the outer contour of the cavity section of the molded part 14. When the cooling apparatus 10 retrieves the molded part 14, a first outer surface 28 of the molded part 14 is selectively held in engagement with the curved surface 26 and a second outer surface 32 of the molded part 14 is selectively held in engagement with the flange portion 30. Other cross-sections of the cooling apparatus 10 and all features are contemplated such that any structural features described herein will be implementable on any other molded part application/dimensions and suitably adjusted to net fit to the molded part to be demolded.
The cooling box 12 also has a plurality of integrated internal cooling ribs or fins 36 integrally formed with and extending from the tool nest portion 20 into the internal chamber 18 to improve the cooling cycle time to a predetermined temperature. The ribs 36 are preferably solid and extend linearly from the rear of the tool nest portion 20 toward the back of the cooling box 12. The ribs 36 are spaced apart a predetermined operable amount and arranged parallel with one another. The ribs 36 also have various lengths.
At least one port 38 is operably provided in the housing 16 of the cooling box 12. A vacuum line 40 is operably coupled thereto and in fluid communication with the internal chamber 18 for providing a vacuum through the cooling box. Preferably, there is provided integration of vacuum line attachment features for connection to the vacuum line 40. The vacuum line 40 is coupled to a vacuum unit suitable to selectively remove a predetermined amount of air from the internal chamber 18 and create a predetermined pressure differential between the internal chamber 18 and atmosphere. A vacuum or vacuum force is generated operable to demold and cool the molded part 14 for a predetermined duration before the molded part 14 is released from the tool nest portion 20. The cooling cycle is reduced since the molded part 14 finishes the cooling cycle in the cooling apparatus 10 while the mold is closed and starts making the next part(s). Optionally, at least one additional vacuum port, generally shown at 42, is provided through the tool nest portion 20.
Further, in accordance with the present invention 3D printing techniques and machinery are operably configured and adjusted to 3D “print” the end of arm cooling box 12 that is to be net fit to the cavity side of the molded part 14 to be demolded. A fully assembled form fitting cooling box 12 is provided. The cooling box 12 is mounted directly to the demolding robot 24 and is a net fit to the cavity inside of the molded part 14. This allows the cooling cycle to be cut, e.g., by at least half, since the molded part 14 finishes the cooling cycle in the end of arm tooling (cooling box 12) while the mold is closed and starts making the next part. The printed cooling box 12 is solid and microporous, preferably, 60% solid and 40% microporous. This allows for improved demolding and cooling cycle times. Additional vacuum ports 42 can be formed into the cooling box, e.g., through the microporous tool nest portion 18 when printing the cooling box 12, to additionally help aid in part demolding and fixturing while cooling a predetermined amount.
The embodiments of the present invention improve cycle time over standard injection molding processes, e.g., improvement in cycle time is at least 25%. The improved cycle time is made without substantial cost, which is a significant benefit over conventional systems/methods, and can help to eliminate secondary machinery or tooling. Using 3D printing allows for the manufacturing of an at least partially porous cooling box. The cost of “printing” and sintering such cooling tools is significantly lower. The speed of manufacturing cooling tools is significantly improved, e.g., builds cooling box 12 overnight. By way of non-limiting example, the build rate is at least ¼ inch per hour. Stainless steel powder, aluminum powder, magnesium powder and the like or other suitable materials can be used for the cooling box 12.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
This application is a PCT International Patent Application and claims benefit of U.S. Provisional Patent Application No. 61/886,938 filed Oct. 4, 2013. The disclosure of the above application is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2014/059070 | 10/3/2014 | WO | 00 |
Number | Date | Country | |
---|---|---|---|
61886938 | Oct 2013 | US |