Dual core forming machine

Abstract

A machine for production of cores for use in castings includes a platform for supporting two core boxes and a split filler head having dual discharge channels for simultaneously injecting core sand into two core boxes and for simultaneously applying curing gas to core sand injected the two into core boxes.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to method and apparatus for the production of cores used for the creation of cavities in an object formed by casting.

[0003] 2. Background Art

[0004] In forming an object by casting, a mold with an inner cavity defining the outer contour of a product to be cast is commonly used. To form a cavity within the casting, a core shaped in the form of the cavity to be formed is typically positioned within the mold. Such cores are commonly produced by a molding process using a core-forming machine. The core forming machine typically includes a core box formed by two opposing mold plates, each provided with a cavity shaped in the form of one half of the core to be formed. The two mold plates are forced together and held together under pressure, to create a cavity defining the core. Core forming machines typically include a sand magazine that is temporarily positioned over the opening in the core box in the core forming process, and sand is forced from the magazine into the opening in core box, typically by compressed air or the like, to form the desired core. The sand magazine is then moved away and a gas magazine is moved into position over the opening and a suitable curing gas is injected into the mold under pressure to cure the sand in the core cavity. Certain additional steps such as vibrating, pressing, vacuum drawing of the core sand, or the like, all well known in the art, may be performed to assure that the core sand flows into all of areas of the mold. The mold plates are then separated to allow the core to be removed.

[0005] A problem with known core forming machines is that they are typically complex and expensive to build and operate and, since each of the necessary core production steps has to be performed individually for each core, it tends to be a time consuming process.

SUMMARY OF THE INVENTION

[0006] These and other problems in the prior art are overcome in accordance with the invention by core making apparatus wherein core forming steps, such as filling, injecting curing gas, etc. are applied to multiple core boxes, simultaneously and in parallel, by the use of a single sand magazine and a single gas magazine, under control of a single control complex that controls the core making process and that may perform such additional steps as vibrating, pressing, etc. of the multiple core boxes, simultaneously. In a particular embodiment of the invention, multiple core boxes are disposed adjacent each other and are provided with filler openings. A multi-channel, filler head is provided adjacent upper filler openings of the core boxes, whereby the multiple core boxes are filled simultaneously. Furthermore, a curing gas may be applied simultaneously to the multiple core boxes, via a multi-channel gassing head.

[0007] Advantageously, by the use of a core forming machine incorporating the principles of this invention, a plurality of casting cores may be formed in a time period not substantially greater than typically required for the forming of a single core. Furthermore, modifications to existing core forming apparatus in accordance with the present invention for increasing the output of the core forming apparatus, are relative inexpensive to implement.

[0008] In accordance with one aspect of the invention, a center section is mounted between two core boxes to be filled simultaneously. Advantageously, the center section serves to assure proper alignment of two core boxes with the multi-channel filler and gassing heads.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a front elevational view of a core forming machine incorporating principles of the invention;

[0010] FIG. 2 is a partial cutaway view of the core-forming machine of FIG. 1 showing the sand magazine in a discharge position;

[0011] FIG. 3 is a cross-sectional view along line 3-3 of FIG. 2;

[0012] FIG. 4 is a top elevational view along line 4-4 of FIG. 1; and

[0013] FIG. 5 is a cross-sectional view along line 5-5 of FIG. 1.

DETAILED DESCRIPTION

[0014] Shown in FIG. 1 is core-forming apparatus 100 arranged for simultaneously forming two cores for use in castings. The core forming apparatus includes a table 104 having a table top 105, supported on legs 106. Resting on the table top 105 are two separate core boxes 101, 102. The two core boxes are separated by a center section 130 extending in a direction perpendicular to the table top 105. The center section 130 is mounted to table top 105 via one or more bolts 139 and serves as an upstanding support for separating the two core boxes 101, 102. As depicted in the drawings, the core boxes 101, 102 each comprise two separate core box halves 101A, B and 102A, B, respectively. Further supported on the table top 105 are pressure application units 131, 132. Each of the pressure application units includes: a pressure unit 131A, 132A; a pressure application head, 131B, 132B; and a piston rod 131C, 132C. A piston rod extends from each pressure unit to the corresponding pressure application head. Such pressure units are well known in the art and may be hydraulic or pneumatic pressure units, or the like, adapted to apply sufficient pressure to hold the separate halves of core boxes tightly together during the core forming process. The center section 130 is preferably made of steel or similar material, sufficient to withstand pressure applied by the pressure application units 131, 132. Alignment rods 140A,B and 141A,B extend between the pressure units 131A, 132A and through the box halves 101A, B and 102A,B, as well as through the center section 130, and serve to align the core boxes 101, 102.

[0015] Further shown in FIG. 1 is a sand hopper 150, supported on an upstanding support 153. Disposed in alignment with the sand hopper 150 is sand magazine 110 supported on brackets 156, 157 mounted on a rotatable shaft 155. The sand magazine 110 is provided with a filler head 111. Also shown in FIG. 1 is a gas magazine 120 provided with a gassing head 121 and supported on brackets 166, 167 mounted on a rotatable shaft 165. A control unit 160 controls the filling of the sand magazine 110 from the hopper 150 and the charging of the gas magazine 120 from a gas supply, in a standard and well-known fashion. Furthermore, the control unit 160 controls movement sand magazine 110 and the gas magazine 120 from a filling position, as depicted in FIG. 1, to an unloading position in alignment with the core boxes 101, 102. Sand magazines and gas magazines and control units, such as the control unit 160, are well known in the art and commercially available.

[0016] Further shown in FIG. 1, are a filler head 111, attached to the sand magazine 110, and a gassing head 121, attached to the gas magazine 120. Shown in FIG. 2 is a front elevational view of the core boxes 101, 102 and a partial cut-away view of the sand magazine 110, rotated 90 degrees from a sand loading position depicted in FIG. 1. As shown in FIG. 2, the split filler head 111 has two separate discharge channels, i.e. conduits 111A, 111B. A cross-sectional view of the split filler head 111, along line 3-3 of FIG. 1 is shown in FIG. 3. In the present embodiment, the gas magazine 120 is provided with a split filler head 121 having a configuration identical to the split filler head 111.

[0017] During core forming operation, the sand magazine 110 is initially disposed in alignment with a sand hopper 150, as depicted in FIG. 1, and is supported on a support bracket 155 in a standard fashion. The control unit 160 controls operation of the sand hopper 150, as well as movement of the sand magazine head 110 and charging and moving of the gas head 120, in a standard fashion. The control unit 160 also controls the rotatable shafts 155 to which sand magazine support brackets 156 and 157 are mounted, as well as the rotatable shaft 165, to which the gas head support brackets 166, 167 are mounted. In a normal sequence of operations, the control unit 160 moves the sand head 110 from the loading position of FIG. 1 to a position wherein the sand magazine 110 is in alignment with the sand hopper 150 and controls the sand hopper 150 to discharge a specified amount of core sand into the sand magazine 110. Thereafter, the control unit 160 moves the sand magazine 110 from the loading position to an unloading position by rotating the shaft 155 by 90 degrees and lowering it such that the filler head 111 is adjacent upper surfaces of the two core boxes 101, 102, as depicted in FIG. 2. In this position, the sand magazine 110 is positioned for filling the two core boxes 101, 102, simultaneously. The simultaneous transfer of sand from the single sand head to the two core boxes via the filler head 111, is controlled in a standard fashion by the control unit 160 by opening an internal valve (not shown in the drawing) in the sand magazine 110. In this manner, the split filler head 111 allows the two core boxes 101, 102 to be filled simultaneously via the two separate legs 111A, 111B depicted in FIGS. 2 and 3.

[0018] FIG. 4 is a top elevational view along line 4-4 of FIG. 1. FIG. 4 shows the upper surface of the core boxes 101, 102 separated by the center section 130. As depicted in FIG. 4, the core boxes 101, 102 are provided with filler openings 145, 146, respectively. When the split filler head 111 is properly aligned with the core boxes 101, 102, the openings 145, 146 of the core boxes are aligned with the openings 111A, 111B, respectively, of the filler head 111 shown in FIG. 3. Similarly, when the split gas head 121 is aligned with the core boxes 101, 102, the openings 145, 146 are aligned with the openings 111A, 111B. Further shown in FIG. 4 are support rods 140 and 140A. Support rod 140A is disposed behind the support rods 140 and is not visible in FIGS. 1 and 2.

[0019] In the core forming process, two cores are formed simultaneously by depositing core sand, specifically formulated for use in forming cores, in the two core boxes 101, 102. The core box halves 101A, 101B are forced together and against the center section 130 by pressure applied by the hydraulic unit 131A to application head 131B. Similarly, the core box halves 102A, 102B are forced together and against center section 130 by the pressure applied by the hydraulic unit 132A to application head 132B. The pressure applied by the hydraulic units 131A, 132A is preferably applied simultaneously and with substantially equal pressure.

[0020] After completion of the filling of the core boxes 101, 102 with core sand, the sand magazine 110 is removed to the position shown in FIG. 1 and the gas magazine 120 is moved into the position previously occupied by the sand magazine 110. All under control of the control unit 160. As depicted in FIGS. 1 and 5, the gas magazine 120 is provided with a split gassing head 121 having two separate discharge openings 160, 161. The openings 160, 161 are to be aligned with the openings 145 and 146 of the core boxes 101, 102, respectively. In this manner, a curing gas is applied simultaneously to the two core boxes 101, 102 from the gas magazine 120.

[0021] FIG. 5 is a cross-sectional view of gassing head 121 along line 5-5, showing openings 160, 161 for discharging a well-known curing gas, or the like into the core boxes 101, 102. When positioned adjacent the core boxes 101, 102 the two separate legs of the filler head 121 are in alignment with openings 145, 146 of the core boxes 101 and 102, respectively. An appropriate curing gas is forced from the gas magazine 120 into the core boxes 101, 102 in a standard fashion to solidify the sand deposited in the core boxes from the sand magazine 110. Thereafter, the gas magazine 120 is removed to the position depicted in FIG. 1 and the pressure plates 131B, 132B are retracted by operation of the hydraulic cylinders 131C, 132C, respectively. The newly formed cores may then be removed from the core boxes 101 and 102 in a standard fashion.

[0022] To prepare the core boxes for a next cycle of core forming, the hydraulic units 131A and 132A are again activated to return the core boxes to the closed position depicted in FIG. 1. Furthermore, the gas magazine 120 is moved to a position over the core boxes 101, 102, in the manner depicted for the sand magazine 110 in FIG. 2, and a purging gas is applied to the core boxes in preparation for a next cycle of core forming. Thereafter, the gas magazine 120 is once again returned to the position shown in FIG. 1 and a new cycle of core forming, described above, may be initiated.

Claims

1. A core forming machine for simultaneously forming a plurality of cores for use in a casting process, the core forming machine comprising:

a core box support platform having an upper surface and having a center position and first and second opposite ends;

a first pressure application unit disposed adjacent the first opposite end;

a second pressure application unit disposed adjacent the second opposite end;

a first core box for forming a first core and disposed adjacent the first pressure application unit;

a second core box for forming a second core and disposed adjacent the second pressure application unit;

said pressure application units operable to apply forces to the first and second core boxes for urging the first and second core boxes toward each other.

2. The core forming machine in accordance with claim 1 wherein the first and second core boxes each comprise an upper surface and a filler opening in each upper surface and wherein the core forming machine further comprises a sand magazine movable to a position adjacent the first and the second core boxes for simultaneously depositing core sand in the first and second core boxes.

3. The core forming machine in accordance with claim 2 and further comprising a split filler head disposed between the sand magazine and the first and second core boxes, the filler head having a first discharge channel for depositing core sand in the filler opening of the first core box and a second discharge channel for depositing core sand in the filler opening of the second core box.

4. The core forming machine in accordance with claim 1 wherein the first and second core boxes each comprise an upper surface and a filler opening in each upper surface and wherein the core forming machine further comprises a gas magazine movable to a position adjacent the core boxes for simultaneously injecting a curing gas in the first and second core boxes.

5. The core forming machine in accordance with claim 4 and further comprising a split filler head disposed between the gas magazine and the first and second core boxes, the split filler head having a first discharge channel for directing a curing gas into the filler opening of the first core box and a second discharge channel for directing a curing gas into the filler opening of the second core box.

6. The core box forming machine in accordance with claim 1 and further comprising an upstanding post disposed between the first the second core boxes.

7. The core box forming machine in accordance with claim 6 wherein the upstanding post is mounted to the support platform.

8. The core box forming machine in accordance with claim 3 and further comprising an upstanding post disposed between the first and the second core boxes.

9. The core box forming machine in accordance with claim 8 wherein the upstanding post is mounted to the support platform.