Patent Application
20190193145
The present invention relates to an air set sand molding apparatus.
Mold patterns are used to for making sand molds, which include sand mold patterns, sand mold parts, and sand mold cores used in the metal casting process. A pattern is formed in the sand mold and casting fluid is poured into the sand mold. The sand mold can be formed using a method referred to as air set molding. In air set molding, a mixture of sand, a resin, and a catalyst is poured into a molding flask that includes a pattern. The pattern is at least a portion of the cast tooling or part. The mixture cures in the molding flask to create the sand mold. The cured sand mold must be removed from the molding flask, which presents many challenges. To remove the sand mold, the molding flask is turned over or upside down so that the sand mold drops out of the molding flask by gravity. However, this often times damages the sand mold or the sand mold does not fall out of the molding flask by gravity. If the sand mold does not fall out of the molding flask, the user often times hits the molding flask to urge the sand mold out of the molding flask. Hitting the molding flask (e.g., with a hammer) can damage the molding flask and/or the sand mold. The molding flask is intended to be used multiple times. Dropping the sand mold by gravity can damage the sand mold.
In one embodiment, the invention provides an air set molding apparatus configured to form a sand mold, the apparatus includes a pattern mounting plate including an ejection pin aperture, a molding flask on the pattern mounting plate, the molding flask having a closed lower end and an open upper end. The molding flask including an ejection pin aperture in the closed lower end, an ejection pin movable relative to the pattern mounting plate and the molding flask, the ejection pin movable through the ejection pin aperture of the pattern mounting plate and the ejection pin aperture of the molding flask between a lowered position and a raised position. As the ejection pin moves from the lowered position to the raised position, the ejection pin lifts the sand mold through the open upper end of the molding flask.
In another embodiment the invention provides an air set molding apparatus configured to form a sand mold, the apparatus includes a pattern mounting plate including an ejection pin aperture, an ejection plate movable relative to the pattern mounting plate between a lowered position and a raised position, and an ejection pin coupled to the ejection plate for movement with the ejection plate between the lowered position and the raised position. The ejection pin is movable through the ejection pin aperture of the pattern mounting plate as the ejection plate moves from the lowered position to the raised position to lift the sand mold away from the pattern mounting plate.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
As will be discussed below, the air set molding apparatus 10 automatically and easily removes a cured sand mold 14 (
Referring to
The frame 20 supports the pattern mounting plate 18 above the floor at a convenient working height for the user. For example, in some embodiments, the frame 20 holds the plate 18 about 30 to 40 inches above the floor. The frame 20 includes supports 30 and panels 32. The panels 32 are removably coupled to the supports 30 to that the user can access components within the frame 20 and hidden by the panels 32.
Referring to
The pattern 12 is located inside the molding flask 16 below the open upper end 40 of the molding flask 16. In the illustrated embodiment, the pattern 12 is formed in the bottom wall 36 of the flask 16 and then the sidewalls 38 are attached to the bottom wall 36. In other embodiments, the sidewalls 38 can be already or permanently attached to the bottom wall 36. In other embodiments, the pattern 12 can be separate component that is set on the bottom wall 36 rather than being integrally formed in the bottom wall 36. The ejection pin apertures 42 of the molding flask 16 are located outside the part pattern 12. That is, the apertures 42 form no part of the part pattern 12 and do not interfere with the part pattern 12. Rather, the apertures 42 are located through the flat area of the bottom wall 36.
Referring to
The ejection plate 50 includes several ejection pin apertures 58. The ejection pin apertures 58 are arranged in columns and rows similar to the pattern mounting plate 18. The location of the apertures 58 of the ejection plate 50 relate or match up with the location of the apertures 22 of the mounting plate 18. That is, each of the apertures 58 of the ejection plate 50 lines up with one of the apertures 22 of the mounting plate 18. The pin apertures 58 of the ejection plate 50 are sized to receive an ejection pin 52 to couple the ejection pin 52 for movement up and down with the ejection plate 50 related to the pattern mounting plate 18. For example, in one embodiment, the pin apertures 58 are blind bores, not through bores, in the plate 50 to support the pins 52 for movement with the plate 50. In other embodiments, the pins 52 have an interference fit with the apertures 58.
The air set sand molding apparatus 10 further includes a drive 62 that moves the ejection plate 50 between the raised and lowered position. The illustrated drive 62 includes hydraulic cylinders 64 that raise the plate 50 and allow the plate 50 to be lowered when desired. A double rack and pinion system 66 is utilized to ensure that plate 50 is raised and lowered in a level and even manner and so that one part of the plate 50 does not raise or lower at a different rate. It should be understood that the drive 62 is just one of many possible drive devices that could be used to raise and lower the ejection plate 50. In other embodiments, other suitable drives can be used, such as electric motors, pneumatic or pressurized air, etc.
In operation, the ejection plate 50 starts in the lowered position so that the upper ends 54 of the ejection pins 52 are about flush with the bottom wall 36 of the molding flask 16. The user fills the molding flask 16 with a mixture of sand, catalyst, resin, and an activator. The mixture fills in around the part pattern 12 while the user typically strikes the mixture off using the sidewalls 38 of the flask 16 as a guide to create a level surface 70 (see
The air set sand molding apparatus 10 and ejection system can easily be reconfigured for use with a different molding flasks and patterns simply by moving the location of the ejection pins 52 on the ejection plate 50. The pins 52 are uncoupled or removed from the ejection plate pin apertures 58 and repositioned into different apertures 58 depending on the shape and size of the new pattern and molding flask. The pattern mounting plate 18 also has several pin apertures 22, as discussed above, so that the pins 52 can pass through the plate 18 to lift the sand mold as discussed above.
Thus, the invention provides, among other things, an air set molding apparatus that automatically and easily removes the sand mold from the molding flask with very low risk of damage to the sand mold and the molding flask. Various features and advantages of the invention are set forth in the following claims.
