KR20080065943A - Method of compacting support particulates - Google Patents

Abstract

A method for densely compacting support particulates is provided to make support media flow into voids by moving free surfaces of the support media filled into voids, over the dynamic angle of repose by setting the direction of the voids formed on walls of the patterns or a mold again by the combination of rotating and tilting motions. A method for densely compacting particulate media for a mold(10) or patterns comprises the steps of: arranging the mold or pattern in particulate media formed in a container; applying the united operation of vibration, rotation, and tilting to the container in making the particulate media flow in to fill up voids(V) formed on the mold or pattern walls; tilting the container for a first axial line; and tilting the container for a second axial line.

Description

How to compactly compress support particles {METHOD OF COMPACTING SUPPORT PARTICULATES}

1 is a longitudinal cross-sectional view of a ceramic cell mold with voids in the outer mold wall.

Figure 1A illustrates an example cylindrical mold having a channel-shaped annular void intricately formed in an outer mold wall radially spaced from the riser towards the flask wall, with the flask filled with support particles such as sand. A cross-sectional view of a casting flask containing.

FIG. 1B is an enlarged view showing the state in which the support medium has penetrated into the channel-shaped void, which is allowed at the static stop angle of the support particles.

Figure 2 shows that the channel shaped voids 1 and 4 are completely filled and the remaining channel shaped voids are only partially filled due to the small tilt of the flask, and tilting supports the edge of the flask. FIG. 1 shows the flask of FIG. 1 tilted to enhance the flow of the particle medium into the channel-shaped void, constrained by the overflowing motion.

Figure 3 shows, with sufficient vibration, that a large inclination angle fills the channel-shaped voids 1 to 4 to reinforce the support particles in the void, with the cap forming a particle medium by gravity, which is greater than possible without the cap. FIG. 1 shows the flask of FIG. 1 with a floating lid made of a material of higher density than the bulk density of the medium, which prevents the outflow of the medium in the medium.

4 shows the longitudinal axis of the flask, which is completely filled with channel shaped voids 1 to 4 and the medium acts deeper towards the channel shaped voids 5 and 8 with openings facing downwards. Figure 1 shows the flask of FIG. 1 after being rotated slowly about 180 degrees about L).

FIG. 5 shows the axis L, which shows that the channel shaped voids 1 to 5 are completely filled with dense compression medium and the remaining channels are no longer filled at this inclination angle regardless of the duration of the compression process. The same flask is shown after several rotational cycles centered.

FIG. 6 is a lost foam pattern of an engine block in a support particle medium, showing an engine block pattern with an internal oil channel-forming passageway in communication with the outer surface of the pattern, showing that the pattern is tilted to 45 degrees. cross-sectional view of a casting flask with a pattern).

Fig. 7A shows a lost foam casting flask installed in a circular reinforcement rib and a circular flange in a longitudinal cross section of a square cross section, the flask containing a lost foam pattern corresponding to a pair of engine cylinder heads attached to the riser. And the flask is filled with the support medium, and before the flask is tilted, a rectangular lid with an opening for the injection cup is shown positioned on the surface of the medium, the force vector along the axis of the flask in the lid weight It is shown larger than the counter vector in the wedge of the medium above the stop angle.

7B is a top view of the casting flask of FIG. 7A.

8A is an elevational view, in partial cross section, of a compression device for rotating the casting flask with the engine block pattern of FIG. 6 while inclined between selected angles of inclination;

8B is a top view of the apparatus of FIG. 8A.

9 is an elevational view of a compression test cell with complexly shaped channel shaped voids similar to voids 5 in FIGS. 1-5 completely filled with compressed sand in the practice of the present invention.

Figure 10A is a schematic representation of a test cell showing the theoretical compression sequence.

11A is an elevational view of a self-contained device in accordance with an embodiment of the present invention for compactly compressing a support medium around an anti-gravity cast ceramic cell mold before the container is tilted.

FIG. 11B is an enlarged cross-sectional view of the enclosed area of FIG. 11A. FIG.

FIG. 11C is an elevational view of the self-containing device of FIG. 11A, with the optional components shown in cross section for convenience, after the container is inclined to the selected tilt angle.

FIG. 11D is a view taken in the direction of the arrow 11D of FIG. 11C.

11E is a partial elevation view of a drive motor for an Acme screw.

12A is an elevational view of an apparatus according to another embodiment of the present invention in which the support medium is densely compressed around a counter-gravity cast ceramic mold after the container is tilted using a harness pulled by a hand winch.

12B is a top view of the apparatus of FIG. 12A.

Figure 13 is a perspective view of a hydraulically operated compression device in accordance with another embodiment of the present invention for compactly compressing a support medium around a ceramic cell mold or temporary pattern.

14 is an isometric view of another hydraulically operated compression device in accordance with another embodiment of the present invention for compactly compressing a support medium around a ceramic cell mold or temporary pattern.

Figure 15 is an enlarged cross sectional view of the multifunctional floating lid of Figure 14;

FIG. 16 is a perspective view of the apparatus of FIG. 14 showing the flask inclined past the horizontal direction.

FIG. 17 is a partial perspective, partial cross-sectional view of the flask lid component of FIGS. 14 and 16. FIG.

FIG. 18 is a perspective view of the apparatus of FIG. 14 showing a vibrator mounted directly to a casting flask, the main structure of which is expanded to accommodate the vibrator rotating into the flask. FIG.

Explanation of symbols for main parts of the drawings

10, 310: mold 12: color 20, 320: casting flask

30, 330: support particle medium 40, 340: lid 100: support deck

113: frame 133: cradle 265: motor

271: lever 350: nest

V: void GV: gravity vector OP: aperture

The present invention relates to a method and apparatus for densely compressing support particles for casting molds or fugitive patterns in a container.

Metal casting is known to allow ceramic cell molds to compactly compress support particles, such as sand of flexible motion, into the vessel during casting to surround and support the outside. U.S. Patent 5,069,271 and other documents describe such casting methods. Another casting method described the foam pattern of the article being cast covered with a heat resistant coating to compactly compress and support the support particles, such as sand, in the container during the casting called so-called lost foam casting to surround and support the outside. US Pat. Nos. 4,085,790, 4,616,689, and 4,874,029 describe such lost foam casting methods.

Compressing support particles surrounding the outside of a ceramic cell mold or foam pattern in a casting flask (container) is a demanding process. First, support particles, such as loose sand, have to flow into the deep voids about the outside of the cell mold or foam pattern. In order to improve the free flow of sand, the bridging of the particles must be eliminated. The particles must then be integrated and hardened to structurally support the ceramic cell mold or foam pattern. The cell mold may be very fragile depending on the cell mold wall thickness and surface properties of the foam pattern coated with the refractory material. The two requirements are contrary to each other.

Simple vibrations of casting flasks have been used in the past to consolidate and strengthen support particles over all outer sections of a mold or pattern. The vibration of the casting flask should be severe enough to cause the conversion and strengthening of the support particles, but not so severely that it will not crush or damage soft and fragile molds or patterns.

To facilitate the filling of long, narrow channel-shaped voids outside the cell mold or fire-resistant coated foam pattern, the cell mold or foam pattern is oriented so that the channel-shaped void is vertical or nearly vertical. It must be When this structure is not possible, most compression processes solve this problem by adjusting the filling rate to fill the casting flask. Only the upper part of some free surface of the support particles flows easily, so this approach fills the particle medium until it reaches a level of horizontal channel-shaped voids that are difficult to fill, and the moving particles move to the end of the channel-shaped voids. It is necessary to wait the process of filling the particles until they have a chance. At this time, the filling of the casting flask is repeated until the particles reach the void, which is difficult to fill next. Confidence in this technique depends on precise vibration and particle addition, means, and control of the exact fill level.

Another problem with this approach is that in some compression processes, the upper part of the cell mold or foam pattern is supported from above, while the lower section is partially embedded in the vibrating support particle medium to move the casting flask. Flexural movements occurring in a mold or pattern cause distortion of the mold or pattern and cracks in the mold walls or cracks in the pattern coating.

As an attempt to solve the above problem, there is a method described in US Pat. No. 6,457,510, which correlates with each other to tune the four vibrators and shake the four casting flasks in part to cause the support particles to move laterally. This involves changing the direction of rotation and the eccentric phase angle. This process, however, requires specific vibration-vector changing means adapted to the voids of the geometry in the form of passages. Moreover, the controlled shaking motion is constrained to one plane perpendicular to the axis of the four vibrators. Finally, the compression process of this patent, like all compression processes, is in constant engagement with gravity when trying to flow the support medium.

The present invention provides a method and apparatus for densely compressing a support particle medium to a casting mold or temporary pattern in a container, comprising a systematic system for vibrating the container, rotating the container, and tilting the container in relation to the gravity vector. Using a combination of steps, the mold or pattern orientation is altered in such a way that the support particle medium is induced to fill a simple composite void in the mold or pattern wall. A support particle medium is induced to flow into the voids, where the particles are captured and strengthened by gravity and vibration vectors that change with respect to the mold or pattern during the implementation of the method.

One embodiment of the present invention is to alter the mold or pattern orientation with respect to the gravity vector, including continuously vibrating, continuously rotating, and continuously tilting the vessel. Another embodiment of the present invention involves tilting the container at increasing tilt angles while compacting the particle medium. The vessel is subjected to rotation and vibration continuously or intermittently at each increasing tilt angle. Another embodiment of the present invention includes a step in which the container is rotated and vibrated while the container is inclined at a fixed tilt angle with respect to the gravity vector.

The present invention densely compresses the support particle medium with respect to gravity casting molds or patterns as well as counter gravity casting molds or patterns.

In an embodiment of the method to illustrate the invention, a mold or transient pattern is placed in the flask and the flask is filled with the support particle medium. The flask is set such that the vessel vibrates and rotates about the first axis continuously while being inclined continuously or fixedly about the second axis with respect to the gravity vector. The combination of tilting against vessel vibration, rotation, and gravity vectors causes channels, chambers, crevices, and other voids formed into specific structures of the mold or pattern wall to be repeatedly and systematically reorientated, such that The free face of the support particle medium in the void is moved past the dynamic angle of repose and caused to flow into the void by the combined action of the continuously altered orientation and vibration of the hole. The systematic repeating operation of such flasks will eventually fill the voids formed into the mold or pattern wall with compressed support particle media eventually. If the orientation of the voids circulates while rotating so that the openings of the voids face downward, the support particles reinforce the particle medium blocking the void openings and prevent them from exiting the voids. The lid is optionally placed on the upside facing side of the particle medium in the container to increase the angle at which the container is tilted during the compression method.

In an embodiment of the device describing the present invention, the container is disposed in the rotatable fixture and the first motor is installed to rotate the fixture such that it can rotate about the container about the first axis. The fixture is in turn arranged in a tiltable frame and a second motor is installed to tilt the frame so that the container is tilted about a second axis with respect to the gravity vector. One or more vibrators are disposed on a table that supports the frame, on the frame, on the fixture, and / or in the container. A source of support particles is provided to fill the container with particles after the mold or pattern is received in the container.

The compression method and apparatus of the present invention have the advantage that they specify a minimum portion and do not require complex particle supply means. In addition, the compression method and apparatus of the present invention may be practiced to compactly compress the support particle media for gravity casting molds or temporary patterns, as for countergravity casting molds or temporary patterns.

The above and other advantages will be more readily understood from the following description with reference to the accompanying drawings.

The present invention uses a vessel in combination with a vessel inclined relative to a gravity vector, vessel rotation, and vessel vibration to alter the orientation of the mold or pattern in a manner that induces the support particles to fill a simple plurality of voids in the mold or pattern wall. It is to provide a method and apparatus for compressing support particles within a temporary pattern such as a plastic pattern or a casting mold such as a ceramic cell mold. The present invention is used to compactly compress support particles into voids around any type of mold or temporary pattern used in metal or alloy castings where action to support the mold or pattern is required.

Referring to FIG. 1 for illustrative purposes as a non-limiting technique, a thin walled ceramic cell mold 10 may be subjected to counter gravity casting as described in US Pat. No. 5,069,271, the disclosure of which is incorporated herein by reference. It has a plurality of mold cavities (10b) and the central riser passage (10a) in communication via the riser passage and each gate passage (10g) to receive the molten metal or alloy. Generally, the ceramic cell mold 10 is formed by a well-known lost wax process, and the temporary (eg wax or plastic) pattern assembly (not shown) is repeated until it is reinforced to the required cell mold wall thickness. It is put into a ceramic slurry, the excess ceramic slurry is discharged, it is coated with the coarse ceramic stucco, and it dries. The temporary pattern is then selectively removed away from the ceramic cell mold, and the ceramic cell mold is heated to give sufficient strength for the molten metal or alloy to be cast there. The cell mold 10 includes the above-described patents for casting molten metal or alloy at opposite gravity into the mold cavity 10b and the ceramic closure member 12 'and through the riser passage 10a upwards. A ceramic collar 12 is provided in communication with the same fill tube (not shown). The present application is practiced with a ceramic cell mold having an arbitrary cell mold wall thickness that needs to support the cell mold wall during the casting process.

The present application is not limited to being practiced with a ceramic cell mold of the type shown in FIG. 1 casting a metal or alloy at opposite gravity, which can be carried out by gravity casting a metal or alloy and in any type of casting mold. As the non-limiting substrate for the purpose of explanation only, a ceramic cell mold supported by a support particle medium for gravity casting of a metal or alloy is used in practicing the present invention. Similarly, the application is embodied in a temporary pattern, such as a plastic (eg, polystyrene) foam pattern, on a container as a non-limiting substrate described for illustrative purposes, which pattern is optionally coated with a thin fire resistant coating on the outer side of the pattern. It can be.

As shown in FIG. 1, the ceramic cell mold 10 includes an outer structure that forms a plurality of elongated channel- or crevis-shaped voids around the outer surface or wall of the mold. The voids V extend in the lateral direction (generally in the radial direction) in relation to the riser passage 10a. For example, the voids V are formed between the laterally extending mold sections 10s forming each mold cavity 10b. By the way, the void V may have any shape and / or orientation correlated with the riser passageway depending on the particular external structure of the mold used. 1 is a simplified illustration to illustrate a representative void V filled with densely compressed support particles according to the present invention.

1A additionally illustrates a casting flask (container) 20 containing an example cylindrical casting mold 10 belonging to the support particle medium 30, wherein the mold 10 is an inner wall of the flask 20. FIG. With elongated channel-shaped annular voids (V) intertwined, for example, located on the outer mold wall (10w) radially outwardly from the riser passageway (10a) in the direction toward. Void (V) is shown with a modified structure to illustrate other void shapes filled with dense compressed support particles (eg, dry sand) by practicing the present invention.

For example, consider a cylindrical mold 10 having a plurality of complex structures of voids V, as shown in cross section in FIG. 1A. Once the mold 10 is placed in the flask 20 and the flask is filled with the support particles, a small amount of particle medium 30, which is determined at a static stop angle, is shown in FIG. ) Will flow into. Vibration of the flask 20 will allow a small amount of the top of the particle medium 30 in the flask 20 to flow, but will not lead to much more particle medium flowing into each void V.

If the flask 20 is inclined at a fixed inclination angle A with respect to the gravity vector GV as shown in Fig. 2, the particle medium 30 has an upper opposed opening OP and is tilted approximately downward. It will easily flow into the photo void (V). The voids 1 and 4 shown in FIG. 1A are completely filled with a soft (dry) particle medium, while the voids 2 and 3 are only partially filled before the particle medium begins to flow over the edge of the flask. Vibration will enhance the motion of the particle medium flowing into the void, thereby increasing the strength of the particle medium in the void. In addition, vibration will cause more media to flow in the flask 20.

As the particle medium 30 flows into the void V and is compactly compressed, the medium from above flows along the gravity vector to replace the void. As a "bubble" it is useful to make the void visible. As the medium slowly flows downward, this "bubble" becomes rarified media and moves upward against the gravity vector until it encounters a surface that cannot penetrate. If this happens, the “bubble” will form a void under the face. Depending on its shape and orientation, the face will capture "bubbles". For example, a plane that is perpendicular to the gravity vector will capture "bubbles". Compression in one zone is at the expense of compression that failed in another zone. In an embodiment of the present invention, the void “bubbles” are systematically oriented back to the capture surface to escape. If the “bubble” hits the inclined flask wall, the bubble will move along the flask wall until it escapes through the upper open side of the particle medium 30.

When a loosely fitted lid 40 made of a material of higher density than the bulk density of the particle medium is placed on the top side of the particle medium 30 (FIG. 3), the flask 20 is placed over the edge of the flask. It can be tilted at a significant steep angle so that it does not overflow. The force received from the weight of the lid 40 perpendicular to the surface of the medium is greater than the lifting force due to the wedges of the particle medium 30 produced at a stop angle as described in FIG. 7A. Because of this fact, the flask 20 can be tilted to 45-50 degrees without flowing the particle medium 30. As shown in FIG. 3, at an angle of inclination made possible by the lid 40, more voids V are completely filled with the particle medium. Vibration of the flask 20 speeds up the filling of the voids and densifies the particle medium after the voids are completely filled. As the particle medium fills the voids and dense in the flask and voids, the generated rare media "foam" acts as a path from under the lid 40 to the top side of the particle medium, exiting along the rim of the lid. . As a result, the upper face of the particle medium 30 is lowered, causing the lid 40 to be placed deeper into the flask 20.

When the inclined flask 20 rotates slowly about its longitudinal axis L, the void V, which is radial in the riser passage 10a of the mold 10, is upward as shown in FIG. This moves to the point facing the opening OP. Thus, each void receives the particle medium during the rotation cycle of the flask. 4 shows the mold after half rotation. The voids facing downward do not lose the particle medium because the particle medium compressed outside the void blocks the opening OP. If the rotational speed is a sufficient slow speed, the voids 1 to 4 will be filled in one rotation. By the way, with respect to the voids 5, 8, during circulation when the opening OP for the void faces downward, the particle medium will move deeper into the void, and a temporary gap in the particle medium column at the void. (temporary gap). After the flask has been rotated several times, the zigzag voids 5 are completely filled with densely compressed particle media as shown in FIGS. 5 and 10L.

As the lean media “bubbles” rise vertically along the gravity vector, the passage through the media is distorted by rotation and spirals in a direction towards the flask inner wall. If the "bubbles" hit random obstacles that could not penetrate the medium, they would build up under those obstacles. If the obstacle is a mold surface, it will release a “bubble” facing up during the rotation cycle of the flask. Thus, in the end, the lean medium “foam” hits the flask inner wall and, due to the rotation of the inclined flask, caused the flask inner wall to escape through the exposed top surface of the particle medium as described above. Will spiral up along the spiral.

This particle medium and lean medium “bubble” transfer process is characterized by random void V, regardless of its complexity, while the entire section of the void is tilted downward during at least a portion of the rotation cycle of the flask 20. Will fill completely). The inclination must be greater than the rest angle of the particle medium to accommodate the given vibration imparted to the flask 20. This angle is hereafter referred to as the dynamic angle of repose of the particle medium and is much less than the static stop angle.

In Fig. 5, the voids 6, 7, 8 cannot be completely filled under the above-mentioned flask vibration, rotation and tilting conditions. This is because the end of the void 6 is inclined upwards during the entire cycle of rotation of the flask and the last two sections of the voids 7, 8 are always blocked by the fourth section which is inclined upwards. The voids 6, 7, 8 will be filled by another embodiment of the present invention as described below.

Although the voids V are shown in the plane containing the flask longitudinal direction (rotatable) axis L in FIGS. 1-5, the voids are inclined downward during the rotation cycle of the flask 20. While it is, it may be directed in any direction to be filled with the particle medium 30. Also, if the voids 6-8 in Figures 1-5 are oriented in a "plane perpendicular to the longitudinal (rotatable) axis of the flask" void (plane parallel to the container bottom) void Is easily filled with the densely compressed particle medium by vibration and rotation of the inclined vessel as described above.

9 is a compression test cell (template or pattern) having a tangled channel-shaped void V similar to the void 5 shown in FIGS. 1-5, completely filled with compressed sand by the practice of the present invention. (P) section is an elevation view of). In particular, the compression test cell is constructed of polystyrene rods sandwiched between flat transparent acrylic acid plates (AP). The compression test cell is formed of a channel-shaped void having a 1½ x 1½ inch area of 36 inches in length, similar to the shape of the void 5 in FIGS. In the vertical orientation as shown, a compression test cell is placed at the bottom of a 30 inch deep cylindrical flask, and the flask is filled with dry Calimo22 support medium for 32 seconds. The flask does not vibrate during the filling process. The flask was then inclined at a fixed tilt angle of 30 degrees to the gravity vector (vertical), vibrated to less than 1G, and 2 minutes in a centrifugal casting machine capable of tilting, rotating and weakly vibrating for initial testing purposes. While it is rotated at 6rpm.

This combination of oscillation and rotation of the flask while the flask is inclined at a fixed tilt angle for 2 minutes ensures that the distorted channel-shaped voids of the test cell are completely filled with compactly compressed cast sand.

In contrast, a contrast test using the same casting machine, the same test cell, and the same support medium was carried out using only the flask vibration conditions described above. That is, the flask was not tilted and rotated at a fixed angle of inclination of 30 degrees. The contrast test only partially filled the channel-shaped voids over the upper polystyrene rods with loose media. That is, over 90% of the channel-shaped voids remain empty and not filled with support media.

10A to 10L are diagrams illustrating the charging operation sequence generated in the process of filling and compressing the molded channel-shaped void V in FIG. 9 of the test cell. This sequence is described for the purpose of describing the present application only, and it is to be understood that the sequence is not intended to limit the present application. Referring to FIG. 10A, the test cell is positioned laterally in a vertical flask (not shown) having an open end E of the test cell that is initially forced to the left in FIG. 10A. The flask is oriented in a vertical direction with an open end facing upwards (eg, see FIG. 1A). Casting sand 30 is then introduced into the flask until the test cell is filled in the casting sand. At 10 A, only a portion of the casting sand was shown around the test cell in the flask for convenience. 10B to 10L, the casting sand 30 surrounding the test cell is omitted for convenience. FIG. 10A is a diagram illustrating sand replenishment made only for a static stop angle after filling a vertical flask. FIG. FIG. 10B shows the extent to which the particle medium (sand) is transferred into the void after the filled flask is inclined at an angle of inclination of 30 degrees and the open end E of the test cell is transferred to a position where the systematic rotation partially faces upwards. It is a figure where the starting orientation of the test cell with respect to the axis of rotation is not critical. In FIG. 10C, the inclined flask is rotated 180 degrees more about the longitudinal axis at 6 rpm, while oscillating below 1 G with slugs of the particle medium shown to flow deeper into the channel. In FIGS. 10D-10K, vibration and rotation of the inclined flask is followed and the particle medium continues the sequential flow into the void until the void is filled with compressed casting sand as shown in FIG. 10L. Through the drawings, it will be understood how the void "bubbles" are classified by the incoming medium and how the "bubble" section acts out of the channel in an opposite flow from the medium. Substantially filling and compressing the voids was done by twelve full revolutions of the flask.

As noted above, the present invention is practiced by densely compressing the support particle media for casting molds or temporary patterns suitable for use in gravity or counter gravity casting processes.

Gravity Casting Embodiment

7A and 7B illustrate a flask 20 'using a gravity cast lost foam pattern 10' disposed in the flask, with the flask filled with the support particle medium 30 '. The following description is for the purpose of description and not of limitation. The flask or vessel 20 'is made of steel or other suitable material, and may take any form, such as, for example, a cylindrical flask or a flask having a square or other polygonal cross section.

Transient pattern 10 'includes an injection cup 10a', riser 10s ', and a pair of engine cylinder head patterns 10p' connected to riser 10s 'by gating 10g'. Pattern 10 ′ is generally made of polystyrene coated with a fire resistant thin layer (eg, ½ mm), which is a non-limiting substrate and is a mica or silica base material.

The flask 20 'has a circular flange 20a' and a circular intervening reinforcement rib 20b 'to facilitate the rolling operation in the compression apparatus of Figures 8A and 8B.

8A and 8B show an apparatus for compressing a particle medium 30 'against a lost foam engine block pattern 10 "shown in more detail in FIG. 6 disposed in the particle medium 30' in a flask 20 '. The following description is for the purpose of description and not of limitation: The support particle medium 30 'comprises dry casting sand or any other free-flow refractory particles, which is typical. The particles are thus non-binding particles free of resin or other binders as described in US Pat. No. 5,069,271. The support particles are optionally in a mold or in a flask 20 'according to the present invention. It bonds in a limited range that does not adversely affect the properties of the support particles that are densely compressed into the fluid relative to the pattern.

Referring to Fig. 8A, the apparatus includes a conventional vibration compression table (base) T '(shown schematically). Optionally or in addition, the separating vibrator may be shown in Figure 11A; 12A and 12B; 14, 16 and 18 can be used in the manner shown. The tilting of the flask 20 'at a selected inclination angle with respect to the gravity vector is described below and shown in FIGS. 11A, 11B, 11C, 12A, 12B, 13, 14, and 16, which are arranged on the vibration table T. And the optional trunnion mechanism shown in FIG. As a technique for illustrative purposes, not limitation of the present application, a trunnion support column 17 'is installed on the table T' so that the rotatable nest 50 'accommodates the flask 20'. Support the shanghai frame 13 'which is arranged to

The flask 20 'is positioned in the nest 50' before the nest 50 'moves up and down in the frame 13'. The nest 50 'includes a base plate 50a' on which the flask 20 'is disposed. The nested base plate 50a 'has a cylindrical recess to receive the bottom of the flask 20'. The nested base plate 50a 'is placed in three crowned roller bearings B1' separated by 120 degrees from the support post 13b 'to the frame 13', so as to surround the circular base plate 50a 'of the flask. It is set to the center by four or more roller bearings B2 'at the support flange 13f' which engages with. Gear motor 60 'rotates nest 50' with drive belt 62 'which engages belt-receiving groove 50g' on base plate 50a '.

While the flask 20 'is directed perpendicular to the nest 50', the pattern 10 "is placed in the flask, and a suitable particle source, such as a hopper (not shown), in which the flask is overhead Is filled with support particle medium 30 ', such as dry casting sand, before the flask is tilted, a rectangular loosely installed free-floating lid 40' with an opening for the injection cup 10a 'is provided at the top of the particle medium. Placed on a surface to prevent overflow when the tilt angle exceeds the stop angle of the particle medium. The injection cup 10a "extends through the lid opening to form a crucible or other melt-holding vessel (not shown). Is exposed to accommodate the molten metal or alloy that is cast as shown in Figure 8B in a gravitational manner. The force vector along the flask's axis at the weight of the lid 40 'is greater than the opposite vector from the wedge of the particle medium 30' above the static stop angle, as shown in Figure 8A. This fact allows the sides of the flask and the top side of the particle medium to remain square when the flask is tilted to 50 degrees. As the medium solidifies, the lid is placed deeper into the flask. When the flask returns to the upright position, the top face of the medium is horizontal.

Vibration of the table T 'and rotation of the flask 20' begins while the flask 20 'is oriented vertically in the nest 50', although the invention is not limited to this sequence. Next, the nest 50 'is inclined to the trunnion support column 17' (only one shown) at a fixed tilt angle with respect to the gravity vector, as shown in Figure 8A. The inclined flask 20 'is provided with two or more rollers disposed on the standing side plate 13s' of the frame 13 'in a manner that engages the circular intermediate rib 20b' of the flask as shown in Figure 8B. The bearing B3 'is supported to rotate in an inclined position. Vibration and rotation of the flask during inclination is continuously carried out on the pattern 10 ", in particular on the engine block pattern, until the voids are filled with densely compressed casting sand.

For further explanation, a lost foam engine block pattern 10 "having an internal oil passage 10p" is shown in FIG. In Figure 6, a flask with an engine block pattern is subjected to parallel vibrations against gravity as shown, even if vibrations in any direction are used to practice the present invention, while the flask is tilted as shown. You will receive a rotation. As the flask rotates, the longest oil channel (101p ") is inclined at 45 degrees. The oil channel (10pp") perpendicular to the longest oil passage is -45 degrees in sinusoidal shape due to rotation. Varies between and +45 degrees. The remaining short oil channel 10sp "extends in and out of the withdrawal plane as shown. This oil channel or passage 10sp" is also changed between -45 degrees and +45 degrees by rotation. During the compression test, substantially the engine block pattern 10 "will pivot several inches away from the flask's axis of rotation (vertical axis) L. As a complete revolution occurs during each orbital revolution of the pattern, the pattern ( The 10 ") oil channel has the same effect of filling and compacting the casting sand.

The apparatus of FIGS. 7A, 7B, 8A and 8B is for use in any mold or pattern that requires the support of a compressed particle medium during gravity casting. In the gravity casting embodiment of the present invention described in Figures 7A, 7B, 8A and 8B, the inclined rotary compression method according to the present invention includes the following.

The casting flask 20 'is fixed to a variable-tilt, rotary nest or fixture 50' on top of a conventional compression table T '. The mold or pattern 10 'is loaded into the flask by hand in a typical manner without vibration of the flask. For example, a small amount of casting sand is placed in the flask and the pattern is gently pushed into the casting sand. In production, the pattern is supported in the flask by a fixture (not shown) at the beginning of the flask filling cycle. Vertical flasks are filled with support particle media such as casting sand by conventional means. In order to shorten the compression process slightly, the flask 20 'will be vibrated during the filling operation, but this operation is not necessary at this point. (If no vibration is introduced during the filling process, no vibration isolator will be needed for the mold-loading fixture.) If not enough particle medium is introduced to maintain the orientation of the mold or pattern, the mold or The pattern will be released and the remaining flask will be filled.

If the flask can be tilted above an angle at which the particle medium can flow, a loosely fitted lid 40 'is positioned at the top surface of the particle medium 30' at this time. The lid has an opening for the injection cup 10a 'of the pattern.

The vibration of the compression table T 'starts with the rotation of the flask about the vertical longitudinal axis L, and the flask 20' is tilted at a compression tilt angle with respect to the gravity vector. For most molds or patterns 10 'having a plurality of voids, an angle of inclination of 30 to 35 degrees is sufficient, and a lid 40' is not necessary.

Flask 20 'is inclined at a fixed angle of inclination ("A") in which the flask is vibrated and rotated continuously or intermittently.

Optionally, while continuously and intermittently vibrating and rotating the flask, the flask 20 'is continuously inclined to a 30-35 degree tilt angle ("A") in a vertical position and, if necessary, is vertical in a forward and backward manner. Return to position

In addition, the flask 20 'is a technique for describing, not limiting its contents, and continuously or intermittently during the time that the container is at each angular position (eg, 10 degrees, 20 degrees, etc.). During vibration and rotation of the vessel, which may occur, increases between the vertical position and the 30 ° -35 degree tilt angle ("A"), such as up to 10 degrees, 20 degrees, and then 30 degrees for a period of time in the vertical orientation. Inclined to Then, the sequence is from 30 degrees to 20 degrees in a certain time, such as vessel rotation and vessel vibrations that occur continuously or intermittently during the time the vessel is at each angular position (eg, 10 degrees, 20 degrees, etc.). And then up to 10 degrees, can be reversed.

Substantially, when carrying out the oblique rotational compression method of the present invention in which the flask is continuously inclined during compression, it is desirable to have a rotational cycle frequency of the flask which is a plurality of inclination cycle frequencies of the flask. In the description for the purpose of description, not limiting the contents, if the flask is rotated at a constant 2 rpm, the flask is circulated in a gentle and continuous state at an inclination angle from 0 degrees (vertical) to an inclined angle, Within a minute thereafter it returns to the 0 degree position. This cycle is repeated until full compression is reached. Such a parameter results in the same opportunity, causing all voids in the mold or pattern symmetrically oriented about the axis of rotation to be filled irrespective of orientation.

For support particle media in which a combination of rotational speed, frequency of vibration and magnitude of vibration is compressed, the inclination angle is defined at the point where the downward flow of the particle medium 30 'at its upper face matches exactly at the rate of rotation of the upper surface of the particle medium. Find out. As long as this angle of inclination is not exceeded, the top face of the particle medium 30 'will be parallel to the rim of the flask 20' and at the level when the flask 20 'returns vertically. The 45 degree inclination angle shown in Figures 6-8 is best for a lost form pattern with a long length of complicated passages, such as an oil channel in the engine block. The floating lid 40 'is necessary to prevent the sand from overflowing.

Flask rotation speeds between 1/2 and 2 rpm are preferred for most molds or patterns. Slow rotational speeds cause the voids V to be horizontal and nearly horizontal so that they incline past the static stop angle of the particle medium for several seconds during each rotation. This fact allows the void to be filled with sufficient time. Very slow rotational speeds will result in longer length compression cycles for complex zigzag motion voids such as voids 5 in FIGS. 1-5, as several rotations will be required to fill the voids.

The high rotational speed changes the void orientation before the medium flow to the void is established. The action of centrifugal force at a sufficiently high speed and radius of rotational motion begins to make the rotation unfavorable. For example, if the flask is rotated at 60 rpm, the void (V) inclined at 30 degrees relative to the vessel axis L having an opening of at least 5 inches in the flask's axis of rotation, which is a component of the gravity vector operating along the void. ) Becomes neutral with centrifugal acceleration and prevents the particle medium from flowing into the void.

At slower rotational speeds slower than 10 rpm, the centrifugal force is virtually negligible and can be ignored. As described above, due to the inclination angle (tilt angle) of the flask, the horizontal void, which rotates to easily partially face upward, is filled in a situation where the combined gravity and vibration are affected. As the flask rotates, the filled voids face downward in part during half the rotation cycle. However, they will not be emptied because their openings are now blocked by the compressed particle medium blocking the openings. Particle media compressed around the mold or pattern prevents the mold or pattern from lifting up in the flask, and thus the mold or pattern does not need to be supported during the compression cycle.

Since the mold or pattern is independent of suspension and does not adhere to non-vibration elements such as mold-loaded fixtures, the distortion of the mold or pattern is minimized.

Deep depth or distortion voids or large-capacity voids with small openings OP will not be completely filled during one rotation cycle. However, this is not a problem. As the free surface in the void rotates past the dynamic stop angle, the flow of particle medium is reset. Thus, it is now rotated over the void, and thus the remaining compressed medium becomes fluid and flows downward again into the void (shown in FIG. 10). The conventional particle compression technique could not do this.

Bridging of the particle media granules or particles will occur randomly. If the crosslinking action occurs near or near the narrow opening of the inner void (e.g., the opening OP of Figure 1A), then the flow of the particle medium into the void forms a dome-shaped auxiliary void formed in place in the opening or void. Will be temporarily blocked by. However, the rotation of the flask converts the secondary dome-shaped voids on its sides and causes collapse of the dome-shaped voids. That is, it resets the media flow for the void. Once the voids are completely filled, gravity and vibration reinforce the particle medium in the void, while the voids are tilted past the dynamic stop angle of the particle medium. If there is no free side left in the void, no more fluidity of the particle medium will occur except above the free side.

The compression cycle is completed by returning the flask to the vertical orientation to stop the vibration and rotation.

Figure 13 illustrates an embodiment of another apparatus of the present invention used to cast a mold or pattern to gravity or counter gravity. FIG. 13 shows a hydraulically actuated compression device attached to the support deck 100 of a conventional compression table (base) T. FIG. The flask 120 is supported by a rotating nest (fixed) 150, which nest is disposed in the nest support frame 113 which can be inclined in turn. The nest support frame 113 is supported by a trunnion post or post 117 secured by a pivot pin 135 (only one is shown) and can be tilted (in a pivotal manner). The trunnion support column 117 is mounted on the deck 100 and is in a fixed base pad 141. The nest support frame 113 has a bow-shaped runner 132 that slides on the bow-shaped rail 133a of the cradle 133 attached or fixed to the base pad 141. The vibration goes from the table (base) T to the rail 133a of the cradle 133 and then to the runner 132 of the nest support frame 113 having the flask 120 thereon, the flask 120 To the base pad 141.

The cradle and runner facility also serves as a centralizing device around the coaxial trunnion pivot pin 135 (only one shown). The flask 120 is operated in the manner described above centering on the pivot pin 135 by operation of the hydraulic cylinder 136 whose one end is connected to the cradle 133 and the other end is connected to the outside of the flask 120. Will tilt. While the flask is rotating, the upper half of the flask is in a pair of roller bearings B3. The lower end of the flask 120 is placed in a cylindrical rotary nest 150 disposed in the nest support frame 113. The nest 150 is independent of the rotation of the combined radial / trust bearing (hidden in the figure). The nest 150 is rotated by the hydraulic motor through the friction drive by the pneumatic tire (hidden in the figure). The flask 120 houses a mold or pattern (not shown) of the type described above and a particle medium (not shown) of the type described above that compresses the mold or pattern.

Countergravity Casting

The apparatus shown in FIGS. 11A-11E is used for any mold or pattern that requires compressed particle media support during anti-gravity casting.

11A-11E illustrate a self-contained apparatus for compressing the support particle medium 230 around the anti-gravity casting ceramic cell mold 210 in the flask 220. The apparatus may also be used well for the purpose of compressing the support particle media for different types of gravity-injected molds or different types of lost foam patterns. It may only be necessary to vary the bottom of the flask 210 and the mold clamping fixture.

In FIG. 11C, the ceramic filling tube 211 is fixed to the cell mold 210. The cell mold is described as ceramic cell mold 10 in FIG. 1 and is described in US Pat. No. 5,069,271 described herein as a reference. Of the type described. The mold 210 is positioned in the casting flask 220 such that the tube 211 protrudes from the bottom of the flask 210. Flask 210 is filled with support particle medium 230 and covered with lid 240 when the flask is tilted to the point where particle medium 230 can overflow from the flask. The flask 210 is placed in a cylindrical nest (fixed) 250 comprising a base plate 250a supported by three crowned roller bearings B1 supported at the bottom of the tiltable frame 213. .

The nest support frame 213 is supported by a trunnion 235 located in the column 217 of the main frame (base) 218. Each pillar has a plate 217a attached to the pillar for mounting the electric vibrator 222 in the combined orientation. The vibrator may be mounted perpendicular to the axis for lateral vibration or horizontally for vertical vibration. The vibrator is basically mounted to make linear vibrations, reverse rotations, or rotate in the same direction for circular vibration patterns. Vibration frequency and amplitude can be adjusted. The compression device is supported by four pneumatic vibration isolation devices 221. In these installations, the entire device vibrates.

Rotation of flask 220 is achieved by gear motor 260 where flask nest 250 is diverted by drive belt 262. The tilting motion of the frame 213 is controlled by the other gear motor 265 and the drive belt 267, which in turn operates on the lever 271 to control the Acme nut attached to the rod 270 which tilts the frame. (Acme) The screw 269 is turned and made. Large amplitude vibrations greater than 1G cause unacceptable wear on brass acme nuts. The inclined flask 220 is supported in rotation by two or more roller bearings B3 disposed on the inclined frame 213 to support the sides of the flask.

In the opposite gravity casting embodiment of the present invention, the inclined rotary compression method according to the present invention is similar to the technology described above in the gravity casting embodiment except for the following.

The ceramic cell mold 210 is permanently assembled in a ceramic tube 211 that allows the melt to enter through the mold.

The anti-gravity casting embodiment includes the following steps. The vertical flask 220 shown in FIG. 11A is filled with a support particle medium 230, such as casting sand, by any conventional means. The flask 220 may be vibrated during the charging operation so that the compression process is slightly shorter, but it is not necessary to do so at this time. (If vibration is not introduced during the charging process, the vibration isolator may Not required for loading fixtures.)

If the flask is inclined past the point at which the media flows over the rim, the floating lid 240 is placed on the exposed side to contain the media 230.

Vibration of the main frame 218 by the vibrator 222 is initiated with the rotation of the flask about the vertical axis L, which is inclined in continuous increments or fixed in the manner described above with respect to the gravity vector. Inclined at an angle of inclination. For most molds or patterns with a plurality of cavities, a maximum angle of inclination of 30 degrees to 35 degrees is sufficient, and a lid is not necessary.

For the support particle medium which is compactly compressed by combining the rotational speed, the frequency of vibration and the amplitude of the vibration, the inclination angle is selected at the point where the downward flow of the particle medium matches the upper face with the rotation rate of the upper face. As long as this angle of inclination is not exceeded, the particle media top face is parallel to the rim of the flask and will be flat when the flask returns vertically.

Flask rotation speeds between 1/2 and 2 rpm do the best work for most molds or patterns. Due to the inclination angle (tilt angle) of the flask, the horizontal void, which partially rotates upwards, is easily filled under the influence of the combined gravity and vibration. Rotation of the flask partially faces downwardly filled voids during the half cycle. However, the void will not be emptied because the opening (eg OP) is now blocked by the densely compressed particle medium.

The compressed particle media around the mold or pattern prevented the mold or pattern from lifting up in the flask so that the mold or pattern did not need to be supported during the compression cycle.

Since the mold or pattern is not attached to non-vibration elements such as mold-loaded fixtures and is independent of floating motion, the warping of the mold or pattern is minimized. Large-capacity voids or deep depths or distorted voids with small openings will not be completely filled during one rotation cycle. However, this is not a problem. As the free face in the void rotates past the dynamic stop angle, the flow of the particle medium is reset. It is now rotated over the voids, and the remaining compression medium becomes a fluid and flows back down into the voids (see Figure 10). Conventional particle compression techniques will not do this.

Crosslinking of the particle media granules or particulates will occur randomly. If crosslinking occurs near or at the opening of the narrow inner void, the flow of particle medium to the void is temporarily blocked by the dome-shaped auxiliary voids formed in place at the void or in the opening. However, the rotation of the flask will convert the secondary dome-shaped voids on its sides, causing the dome-shaped voids to collapse, restoring the flow to the voids.

When the voids are completely filled, gravity and vibration make the particle medium more firm to the void, while the voids are tilted past the dynamic stop angle of the particle medium. Since there is no free side left in the void, the fluidity of the particle medium will no longer occur at or near the void.

The compression cycle is completed by returning the flask in an orientation perpendicular to FIG. 11A, stopping rotation and vibration. Of course, counter-gravity casting, which sends molten metal or alloy upwards through the riser passageway into the mold cavity of the cell mold 210, operates in a different way than gravity casting, which is described in detail in US Pat. No. 5,069,271. Is described.

12A and 12B show a device similar to the device shown in FIGS. 11A and 11B, with a flask tilting mechanism including a harness 280 pulled by a hand winch 282. Only thing is different. This tilting facility has the advantage of not being affected by vibrations greater than 1G. Reference numerals used in FIGS. 12A and 12B have been used in connection with similar parts of FIGS. 11A and 11B.

With the compression efficiency of the variable gravity and vibration vectors in relation to the mold or pattern, vibration amplitudes are not so absolutely necessary as would be required in conventional compression techniques. In many cases where compression is applied, vibration acceleration of less than 1G is sufficient. At amplitudes below 1 G, the flask maintains contact with the support bearings, the compression noise is low, and can accommodate equipment wear. The apparatus of Figs. 11-13 will work well at this low amplitude.

The results measured by the accelerometer indicate that vibrations in one plane cause vibrations in all directions for the unregulated flask, as shown in Figs. Thus, the position and orientation of the vibrator (s) is relatively insignificant. Preferably, the vibrator is attached to the stationary component of the compression device, for added convenience.

Typically, during the entire compression process, the flask needs to be rotated in less than 12 hours. Optionally, the flask is rotated at least 360 degrees and then rotated in reverse 360 degrees. This rotational vibration can be repeated several times as necessary. Each 360 degree rotational vibration has the same effect as two consecutive rotations in the same direction. In general, vibrations of 2 to 6 can achieve full compression. This technique allows the vibrator 322 to be placed directly on the flask 320 to easily power the vibrator mounted directly to the flask, as shown in FIG. An advantage of this embodiment is that more vibration energy is transferred to the particle medium (not shown) in the flask 320. The flange 320f of the casting flask 320 is bolted to, clamped or otherwise supported to the hub or nest (fixed) 350, which hub or nest is supported in connection with FIGS. 14 and 15. As described below, it is held in a tilting platform frame 352 having an impact resistant composite plate that is used as a bearing face between the flange, hub, or nest 350 and the platform frame 352. The hub or nest 350 is rotated by a drive belt 362 driven by the hydraulic motor 360. The tilting operation of the platform frame 352 up to 180 degrees is accomplished completely by the hydraulic actuator 355 disposed on the column 317 mounted to the table T. The table is mounted to the pneumatic vibration isolation device 321. The flask is sealed by a lid (described but not shown in connection with FIGS. 14 and 15). The width of the pillar 317 is made wide to accommodate a vibrating device that rotates like a flask. The advantage of this change is that more vibration energy is transferred to the medium in the flask.

If vibration amplitudes greater than 1G are desired and low noise levels are desired, then the casting flask needs to be fixed to the rotational and vibrational components of the compression device. 14-18 illustrate such an embodiment, in which the flange 320f of the casting flask 320 is bolted or clamped to the hub or nest 350, which hub or nest is flanged 351 and the platform frame. Is maintained between 352. Hub or nest 350 rotates at composite bearing face 349 as shown in FIG. This assembly is captured between the retaining flange 351 and the platform 352. The hub 350 is rotated through a drive belt 362 driven by the hydraulic motor 360. The inclination of the platform 352 up to 180 degrees is made by a hydraulic actuator 355 disposed on the pillar 317, which is mounted to the table T. The table is mounted on four pneumatic vibration isolation devices 321.

The flask 320 is sealed with a lid 340 overlying the support medium 330. The lid includes a rotary union 361 connected to a vacuum source, such as a vacuum pump (not shown), and an inflatable rim seal tube 340t. The inflatable rim seal tube 340t provides an airtight seal against the wall of the flask 320. The lid 340 has a screen 359 through which only air can pass, not through the particle medium 330, such that the flask is partially emptied through the plenum 372 disposed in the lid 340. Allow. The plenum 372 communicates with the vacuum pump by fitting F1 of rotary union 361 and air pump by fitting F2, as shown in FIG. 17 with a compatible rotary union. In communication with the inflating seal 340t. The plenum 372 has radial fins 372a to provide a reinforcement for the screen 359. Atmospheric pressure causes the elastic membrane 363 of the lid 340 to swell up and conform to the top of the particle medium in the flask. The flask is emptied partially in vacuum (eg, 3-4 psi vacuum) via rotary union 361 and plenum 372. The pressure difference set across the lid 340 is used to retain the mold or pattern and the particle medium in the flask as the flask is reversed or reversed across the horizon, as shown in FIG. The lid 340 with the inflatable rim seal tube 340t is maintained by atmospheric pressure acting on the partially emptied flask 320.

During compression, the vibrations of the flask 320 were mounted on two pillars or two electric vibrators 322 ′ of the type shown in FIGS. 14 and 16, mounted directly on the flask 320 as in FIG. And / or provided by vibrator 322. The device is mounted to four pneumatic vibration isolation devices 321 supporting the table T.

During the compression operation on the mold 310, the top surface of the particle medium 330 descends as the particle medium is compressed into the void V in the mold 310 (or pattern) in the flask. The lid 340 is retracted into the flask regardless of the flask orientation by the pressure difference between the partial vacuum in the flask 320 and the external atmospheric air pressure to maintain engagement with the top surface of the particle medium. An airtight, movable sealing operation between the adjacent wall of the flask 320 and the lid 340 is maintained by the inflatable rim sealing tube 340t.

The apparatus of FIGS. 14-18 using with oscillation amplitudes greater than 1G replaces ball roller bearings with radial and thrust bearings 349 made of impact resistant low friction plastic as described in FIG. It differs from an Example. Optionally, two large-diameter angular contact ball bearings (not shown) can be used with the rotating nest captured between them. Regardless of whether there is no loose component hitting freely, the noise and collision force are adjusted as in Figs.

As described above, the casting flask 320 is bolted, clamped or otherwise secured to the rotatable hub or nest 350 interposed between the components of the slope platform. Since the rotary motion hub or nest 350 with the flask 320 fixed to the hub or nest is limited to the range in which they can rotate and tilt, the vibration transmitted to the flask maintains its orientation properties to a greater extent and And the auxiliary vibration outside the surface of a vibration vector becomes small. This fact is achieved by simultaneously changing both the gravity and vibration vectors associated with the mold or pattern in the flask in a gentle, continuous and systematic manner. While the hydraulic motor provides rotation to the nest 350, the hydraulic actuator tilts the platform 352 or continuously at a fixed tilt angle until it reaches 280 degrees.

The flask contains a ceramic cell mold 310 with a filling tube 311. The flask has a lid 340 with an expandable tube seal 340t along its circumference and a rotary union 361 that partially empties the flask and seals expansion. Optionally, an inner tube type check valve (not shown) is used for the expandable tube seal 340t to eliminate air passages in the rotary union for seal 340t. The lid has a flexible membrane that is exposed to atmospheric air on one side and to the flask interior on the other side. Once flask 320 is installed in a mold or pattern filled with loose particle media 330 covered by lid 340, the seal 340t is expanded and flask 320 is expanded to 3-4 psi vacuum. It will be emptied.

At this point, the casting flask 320 may be set up completely opposite. Atmospheric pressure will support the lid 340 and the contents of the flask independent of its orientation.

While compressing the particle medium 330 in the apparatus of FIGS. 14-18, the particle medium flows into the voids in the mold or pattern and is compressed. A "bubble" containing lean media will develop and move to the upper point of flask 320. If the flask is tilted past the horizontal plane, the top point will be at the bottom edge of the flask. Floating upwards, "bubbles" diffuse at a stop angle and accumulate due to any impassable obstacles encountered in the upward passage. With the flask standing upside down, an air gap is formed at the bottom of the flask. As the rotating flask is tilted again in the vertical direction, an air gap is formed spirally along the flask wall up to the top of the flask, where the air gap is taken in by the lid 340 set in the flask to take up some space and The remaining space is then blown out of the flask by atmospheric pressure and filled by the flexible membrane 363. Air displaced within the flask exits through screen 359 at the bottom center of lid 340. Pressure from lid 340 and flexible membrane 363 further compresses the top layer of the medium. If the flask is upside down again, the pressure remains compressed. By tilting the partially emptied flask circulated repeatedly and simultaneously rotating and vibrating the flask systematically, all voids and lean media volumes are channeled along the flask wall and erased through the screen 359 at the lid 340. do.

In carrying out such a more complicated slope rotating compression method of the present invention, it is desirable to have a rotational cycle frequency which is a complex tilting cycle frequency. For example, if the flask rotates at a constant 2 rpm, the next flask is circulated gently and continuously at an inclination angle from 0 degrees to 180 degrees and then returns to 0 degrees in the next minute. This cycle is repeated until full compression is achieved. This parameter results in all voids in the mold or pattern being filled at the same opportunity, regardless of orientation. The apparatus described in Figures 14-18 completely fills all the voids shown in Figures 1-5 with a compressed particle medium.

This embodiment of the present invention can also be used to compress the particle medium around the gravity casting mold. Regardless of the geometry of the flask, the lid is constructed of a sealable flexible membrane as described above. The injection cup in the casting mold is temporarily sealed and the entire casting mold with the injection cup is covered with the support medium. The lid is installed in the chamber, the lid seal is inflated and the flask is emptied to 3-4 psi below atmospheric pressure. Here, the flask can be completely reversed during the compression process. The low pressure difference across the lid is sufficient to hold the contents of the flask. After the compression is complete, the flask is returned to verticality, the lid is removed, and a sufficient amount of media is removed to expose sufficient casting medium to the casting infusion cup.

As a base material which does not limit the present invention as described below by performing an inclined rotary compression process, it has various advantages. The void recesses and horizontal overhangs remoted in the mold or pattern will be sufficiently filled with compressed media, and the face of any free particle media buried deeply under the compressed support particle media during at least one quarter of each flask rotation cycle. Again filling the voids, and the crosslinking action by the media particles or granules, results in crosslinking dome-shaped auxiliary voids as described above, which may result in crosslinking on the sides and top such that the dome-shaped auxiliary voids collapse or fill. It was effectively eliminated by systematic tilting. In addition, the distortion of the mold or pattern is minimized since the mold or pattern does not need to be supported and the gravity vector changes steadily smoothly in relation to the mold or pattern during compression. The feed rate of sending the particle medium to the flask is not altered as in current roast foam compression systems. The flask is quickly filled and then compacted. The vibration vector of the compression table does not change. Instead, the mold or pattern orientation changes systematically in relation to the vibration and gravity vectors. The compression method is partially independent, and no specific compression trick is required for other molds or patterns.

Although the present invention has been described in connection with an optional embodiment, a person of ordinary skill in the art may make modifications, adaptations, or similar formulas without departing from the spirit of the appended claims. It should be understood that the present invention includes all such facts.

Claims (41)

A method of densely compressing a particle medium for a mold or pattern, the method comprising: Disposing the mold or pattern on the particle medium in the container; In a manner of introducing the particle medium to fill the mold or pattern wall with voids, the vessel being subjected to a combined action of vibration, rotation, and tilting. The method of claim 1, comprising rotating the container about the first axis and tilting the container about the second axis. The method of claim 2, wherein the container is rotated about a longitudinal axis. 3. The method of claim 2 wherein the second axis is perpendicular to the first axis. The method of claim 1, comprising continuously, oscillating, rotating, and tilting the vessel such that the mold or pattern orientation with respect to the gravity vector is changed. 6. The compression method according to claim 5, wherein the rotating step comprises the step of vibrating one or more times between one rotation in the first direction in accordance with the rotation made in the opposite reverse direction. The method of claim 1 including tilting the container to increase the tilt angle during compaction of the particle medium. 8. The method of claim 7, wherein the vessel is subjected to rotation and vibration in each tilt angle increment. The method of claim 1, wherein the container is subjected to rotation and vibration while the container is tilted at a fixed tilt angle. The method of claim 1, wherein the combination of rotational and tilting motions causes the voids formed by the outer walls of the mold or pattern to be continuously and repeatedly redirected so that the free surface of the particle medium in the voids moves past the dynamic stop angle. And causing a particle medium to flow into the void by vibrations associated with constant change orientations of the voids in relation to the gravity vector. 11. The method of claim 10 wherein the combination of rotational and tilting motions positions the opening in the void to face downward. 12. The method of claim 11 wherein the reinforced particle medium in the flask blocks the downward facing opening to prevent the particle medium from exiting the void. 11. The method of claim 10, wherein the combination of rotational and tilting motions moves the opening into the voids face upward again again so that the particle medium flows back into the voids. 11. The method of claim 10, wherein when the void is completely filled with the particle medium, the strengthening of the particle medium is such that vibration and gravity act in combination while the void is inclined downward and the opening to the void faces upward. Compression method characterized in that the configuration. The method of claim 10 wherein the container has a final step of returning to a vertical orientation after compacting the particle medium. 16. The method of claim 15, comprising leveling the particle medium after the flask has returned to normal orientation by vibration or manual leveling. 12. The method of claim 10, comprising, on the free face of the particle medium in the flask, a material of denser density than the bulk density of the particle medium, comprising disposing a lid. 18. The method of claim 17, wherein the unregulated lid prevents the particle medium from overflowing in the flask as the flask is tilted past the stop angle of the particle medium. 19. The method of claim 18, comprising tilting the container at an angle of up to 50 degrees with respect to the initial vertical position. 18. The method of claim 17, comprising at least partially sealing the lid against the flask such that a subambient pressure can be set in the vessel. 21. The method of claim 20, comprising moving the lid with a pressure differential across the lid in such a way that it decreases during compression independent of the vessel orientation and remains in engagement with the top surface of the particle medium. . 22. The method of claim 21, wherein the portion or all of the lid comprises a flexible membrane that initially maintains contact with the media surface at differential pressure across the membrane. 21. The method of claim 20, wherein the lid is in communication with the vacuum source via a rotary union and the lid is rotated with the container. 21. The compression method according to claim 20, comprising the step of subjecting the container to continuous rotation and vibration while continuously inclining in a forward and backward direction up to 180 degrees between a vertical, upright and reverse orientation. The method of claim 1, comprising temporarily covering the injection cup of the gravity casting mold in the container with the particle medium prior to compression, and removing the particle medium to a sufficient extent to open the injection cup after compression. Way. The method of claim 1, wherein the anti-gravity mold with the protruding fill tube is disposed in the vessel with the fill tube protruding out of the vessel. 27. The method of claim 26, comprising clamping the fill tube while the flask is filled with the particle medium until the mold is covered with the particle medium. 28. The method of claim 27, wherein after compacting the particle medium, a casting lid is placed on top of the medium, and the surface is worked to remove any possible voids on the surface. The method of claim 1, wherein the particle medium is compressed with respect to the ceramic cell mold. The method of claim 1, wherein the particle medium is compressed against a refractory fugitive pattern. 2. The method of claim 1, wherein the container with the mold or pattern is filled with the particle medium while the container is subjected to a combined action of vibration, tilt, and rotation. The method of claim 1, wherein the container with the mold or pattern is partially or completely filled with the particle medium before the container is subjected to a combined motion of vibration, tilt, and rotation. An apparatus for compressing a particle medium against a mold or pattern, the compression apparatus comprising: A container accommodating a mold or pattern, a rotary fixture on which the container is disposed, a first motor for rotating the fixture to impart rotation to the container about a first axis, and a tilt on which the fixture is disposed ( tiltable frame, a second motor that tilts the frame to tilt the container about the second axis, a base on which the tiltable frame is disposed, and a vibrator disposed on at least one of the base, frame, fixture or container. Compression device comprising a. 34. A compression device as claimed in claim 33 wherein the fixture comprises a rotatable nest disposed in the roller bearing on the inclined frame. 34. The compression device of claim 33, wherein the inclined frame is supported by trunnions to the column connected to the base. 36. The compression device of claim 35, wherein the fixture comprises a rotatable hub to which the vessel is secured, the hub being secured to the inclined platform. 37. The compression device of claim 36, wherein the hub is rotated on the inclined platform by a belt drive. 34. The compaction apparatus of claim 33, further comprising a lid containing a material having a higher density than the bulk density of the particle medium, the lid being received in a container on the top side of the particle medium. 39. The compression apparatus of claim 38, wherein the lid comprises a flexible airtight membrane that is exposed to atmospheric pressure on the opposite side of the particle medium to seal and coincide with the top surface when the top surface is changed by compression. 40. The compression device of claim 39, wherein the lid comprises an inflatable seal. 40. The compression device of claim 39, wherein the lid includes a rotary union in communication with the vacuum source.

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