US3327767A

US3327767A - Method and apparatus for making cored casting molds

Info

Publication number: US3327767A
Application number: US464903A
Authority: US
Inventors: Charles M G Wallwork
Original assignee: Individual
Current assignee: HERMAN Corp A PA CORP
Priority date: 1964-06-19
Filing date: 1965-06-18
Publication date: 1967-06-27
Anticipated expiration: 1984-06-27
Also published as: NL6507879A; GB1057547A; BE665501A; DE1508740A1; DK113463B; ES314413A1; AT261133B

Description

June 1967 c. M. G. WALLWORK 3,327,767

METHOD AND APPARATUS FOR MAKING CORED CASTING MOLDS Filed June 18, 1965 7 Sheets-Sheet '1 FIG. 7.

METHOD AND APPARATUS FOR MAKING CORED CASTING MOLDS June 27, 1967 c. M. G. WALLWORK 3,

METHOD AND APPARATUS FOR MAKING CORED CASTING MOLDS Filed June 18, 1965 '7 Sheets-Sheet 3 FIG. 3

June 27, 1967 c. M. G. WALLWORK 3,327,767

METHOD AND APPARATUS FOR MAKING CORED CASTING MOLDS 7 Sheets-Sheet 4 Filed June 18, 1965 FIG. 4.

June 27, 1967 METHOD AND APPARATUS FOR MAKING CORED CASTING MOLDS Filed June 18, 1965 7 sheets-sheet *3 c. M. G. WALLWORK 3,327,767

June 27, 1967 c. M. G. WALLWORK 3,327,767

METHOD AND APPARATUS FOR MAKING. CORED CASTING MOLDS Filed June 18, 1965 '7 Sheets-Sheet 6 F/G.- 6(a).

V I Lg: Amy

I 8 FIG. 6(d).

Filed June 18, 1965 June 27, 1967 c. M. G. WALLWORK 3,32

METHOD AND APPARATUS FOR MAKING CORBD CASTING MOLDS 7 Sheets-Sheet '7 United States Patent 3,327,767 METHOD AND APPARATUS FOR MAKING CGRED CASTING MGLDS Charles M. G. Wallwork, Abbotts Moss, Chester Road, Mere, Knutsford, England Filed June 18, 1965, Ser. No. 464,903

Claims priority, application Great Britain, June 19, 1964,

25,366/ 64 8 Claims. (Cl. 164-18) This invention relates to foundry cores. These are normally made by one of various well-known methods, by hand, followed by baking in an oven, or by blowing into a hot or cold core-box, and then the cores thus formed are placed by hand in the drag of the mould box before the core is placed finally in position for pouring.

Where there are several cores to be placed it has been proposed to mount the cores in a jig, clamp them in place on it, and then to place the whole jig on the drag and to release the clamps so that the cores then lie in the drag in their correct positions and the jig is lifted clear.

It is an aim of the invention to provide a still further speeding-up of the steps of making and placing the cores in foundry moulds. According to the invention it is now proposed to form the cores, preferably by blowing, in a core box in their correct final relative poistions and then, using the core box itself as a jig, to transfer the cores, still in the core box, directly to the mould.

In this way a whole step is eliminated and the cores never leave the core box in which they are made until they are in position in the mould. Handling of the cores, with possible risk of damage is eliminated and furthermore they cannot be placed in the mould incorrectly. Preferably all the cores that the mould requires are blown simultaneously, although in some situations with complicated moulds further cores, separately made, could still be added manually or mechanically.

The core-making and placing method according to the invention is especially applicable to automatic moulding plant, and in particular to the automatic moulding machine forming the subject of our British Patent No. 803,- 332. In that machine moulds formed between a pair of opposed pattern plates are displaced laterally from the point of moulding and then pushed out of the slider in which they are formed, so as to join a line of previously formed moulds. The vertical faces of the adjacent moulds are in contact and the cavities into which the metal is poured are formed between those faces.

In applying the present invention to such a machine we mount a core-blowing plant adjacent to the start of the line of moulds and provide a mechanism for transferring the core-box from the blowing position to a position in which it engages the exposed vertical face of the end mould of the line, the cores being then transferred to that face whilst the core-box is Withdrawn before the next mould is pushed out of the slider to join the line.

The mechanism necessary for transferring the corebox from the blowing position to the placing position can take any suitable form. In a preferred arrangement the cores are preferably blown in the orthodox manner, i.e. downwards from a blowing head above the core-box, the latter being horizontal. The core-box then has to be turned to the vertical position and moved into line with the axis of the line of moulds, the final movement being an axial one, i.e. in a horizontal direction perpendicular to the plane of the faces of the core-box and of the mould. As the cores engage the mould, means come into action for urging the cores and the core-box apart, so that as the core-box is withdrawn the cores remain in the mould. These means could be in the form of ejector pins, mechanically, hydraulically or pneumatically operated but preferably, according to a further feature of the invenice tion, we simply use compressed air, conveniently feeding it through the same holes that were used for the escape of air during blowing of the cores.

The invention will now be further described by way of example with reference to the acompanying drawings, in which:

FIGURE 1 is a plan view of a part of the automatic casting equipment that forms the subject of our British Patent No. 803,332, showing the disposition of the coremaking equipment of the present invention;

FIGURE 2. is a plan view of the core-making equipment to a larger scale;

FIGURE 3 is an elevation of the lower part of the coremaking equipment, looking in the direction of the arrow in FIGURE 2;

FIGURE 4 is an elevation showing the upper part of the core-making equipment in greater detail;

FIGURE 5 is an elevation looking from the left in FIG- UR-E 4; and

FIGURE 6 shows in diagrammatic form at (a) to (d) the successive steps in the formation of the cores.

FIGURE 7 is a perspective view, looking partially from below, of a cover plate through which the cores are gassed.

Referring first to FIGURE 1, the automatic casting equipment shown comprises a moulding machine 1 in which there is a transversely moving slide 2, somewhat like the slide of a slide projector for transparencies, and this slide has two openings (not shown) which, by horizontal reciprocating movement of the slide, are alternately brought into alignment with a pair of opposed pattern plates (not shown) carried on the ends of hydraulic rams 3. Sand blown into the opening in the slide is squeezed between the pattern plates to form a mould in the form of a rectangular block of sand with pattern impressions in both its vertical faces. When the slide 2 is then moved horizontally this mould comes into alignment with a line 4 or 4' of previously produced moulds and a ram 5 or 5' then operates to push the mould out of the opening in the slide to join the line and form the end mould of the line, the whole line being simultaneously advanced by a distance equal to the thickness of one mould.

This equipment is more fully described in the specification of our British Patent No. 803,332 and it will be appreciated that, while the newly-formed mould is being pushed out of one opening in the slide 2, a further mould is being formed in the other opening, and-moulds are delivered alternately to the two lines 4 and 4'. Casting cavities are formed by the co-operation of the mating faces of every adjacent pair of moulds, metal being poured into them further down the line. i

Just after the ram 5 or 5' has pushed the nearly formed mould out of the slide 2 to join the line 4 or 4' and the ram has then withdrawn, the pattern impression in the face of the mould is exposed. This is the instant at which we have the opportunity to insert the cores and, according to the present invention, we form the cores and then transfer them directly from the core-box to the mold. Therefore we mount the blowing head, for forming the cores, close to the mould and provide a mechanism which transfers part of the core-box back and forth between the position in which the cores are formed and the position in which they are transferred to the mould.

The blowing head could be placed directly over the axis of the line 4 or 4', simplifying the geometry of the movement of the core-box, but in practice we find it better to displace the blowing head to one side, keeping it clear of the moulding machine, and to accept slightly greater complication in the transferring mechanism.

The positions of the core-making apparatus for the two

lines

4 and 4 are shown at 7 and 7' in FIGURE 1.-The

blowing head itself is not shown in FIGURE 1. The transferring mechanism as shown in FIGURES 2 and 3 will only be briefly described here. The core-box, to be described more fully later, comprises two parts, an upper part B and a lower. part A, with the cavities in which the cores are formed disposed partly in one and partly in the other. The lower core-box part A is carried on an arm 15 pivotally mounted to turnabout an inclined axis on a carriage 14 which. can slide on apair of guide bars 11 and 12 on the upper end of a swinging structure comprising pairs of arms 8 and 9. Hydraulic rams 13, 16 and 17 cause the various movements and, as described more fully in the specification of our co-pending patent application, the lower core-box portion A can be moved, by actuation'of the rams, between a position in which it is horizontal with its core-receiving face uppermost, and a position in which its core-receiving face is vertical and lies against the exposed face of the. last mould to join the line 4.

When it is horizontal, the part A lies immediately below the part B, which in its turn lies immediately below the blowing head, shown at H. As shown in FIGURES 4 and the head H is vertically movable on guide pillars 19 under thecontrol of hydraulic rams 20 and the upper core-box part B is vertically movable on the head H under the control of hydraulic rams 21. There is also a cover plate S which can slide horizontally with respect to the upper core-box part B under the control of hydraulic rams 22, between a position in which it is clear of the core-box and a position in which it closes off the upper face of the core-box.

, A mixture of sand and binder is fed in a known manner from a hopper (not shown) disposed above the blowing head H, the supply of material in the hopper being maintained automatically by level-sensing devices. In the upper end of the blowing head H there is a butterfly valve V (or it could be a slide valve) controlling the admission of the sand-binder The cores are formed continuously and automatically by operation in sequence of hydraulic, rams controlling the various movements of the valve V, the head H, the cover plate S and the upper core-box B in a manner to be described with reference to FIGURE 6. The cavities in the core-box are placed so that the cores are in their correct relative positions and when the lower corebox part A is moved by the linkage of FIGURES 2 and 3 to transfer-the cores directly into the mould the corebox thus effectively forms a. jig to hold them in these correct relative positions.

y The wholesquence of blowing the cores and transferring each set after blowing is tuned to synchronise with the production of the moulds in the machine shown in FIGURE 1, so that moulds and sets of cores are'formed in step.

The core-blowing sequence will now be described in greater detail with reference to FIGURE 6. Starting at (a), with the valveV open, the upper core-box part B clamped against the underside of the blowing head H, and the cover plate S withdrawn, there will be a charge of sand-resin mix in the head H. Pressing of a start button will close the valve V and lower the head H and part B down onto the part A, clamping the two parts of the core-box together and also clamping them securely against the perforated lower wall of the head H (FIG- URE 6 (b)). Compressed air isnow admitted through the double side wall of the head H to blow the sand through its perforated lower wall into the core cavities in the box formed by the parts A and B, the excess air escaping through exhaust ports (not shown). After the pressure has been lowered by opening exhaust valves in the head H, the head is lifted, but with the simultaneous application of pressure to the rams 21 so that the upper core-box part B remains clamped to the core-box part A. At the same time the valve V opens to allow a new charge of sand-resin mix into the head H and the cover 4 plate S moves in to cover the now-exposed upper face of the core-box part B. This is shown in FIGURE 6(0).

Where the automatic moulding machine is producing a mould every few seconds it is clearly vital for the curing of the cores to be rapid enough to keep up with this. We use a process in which the cores are cured by gassing, for example with carbon dioxide. The gas is admitted via a pipe P through the cover plate S, which is shown in FIGURE 7 and which has a hollow underside S allowing the gas to permeate the cores and escape through suitable vents. Gas could be admitted through the bot tom box part in addition to or instead of through the cover plate S. Any other known curing or baking method, such as dielectric or radio frequency heating could equally well be used.

When curing or baking is complete, which can be within two or three seconds, the upper core-box part B is lifted, together with the cover plate. As it is lifted, compressed air is fed to the upper faces of the cores through the cover plate S to hold the cores themselves down in the lower box part A, as shown in FIGURE 6 (d). As the part B rises, the cover plate S is withdrawn, allowing the upper face of this part to return into engagement with the blowing head H as it was at the start.

The lower core-box part A is now swung down to a vertical position by rotation of the arm 15, and then this arm, complete with the carriage 14, is swung across by ram 17 until the face of the part A from which the cores project is aligned with, but spaced from, the exposed face of the end mould in the line 4. The carriage 14 now moves on the guide bars 11 and 12 to bring the cores into the moulding cavity, which of course has recesses placed to receive them.

Then, as the carriage 14 is moved in the reverse direction to move the box part A away from the mould, air pressure is admitted within the part A to act on the cores and hold them in the mould, pushing them out of the box part A. Instead of air pressure, we could use ejector pins, operated in any suitable manner, for example by pneumatic or hydraulic cylinders.

The box part A now returns to the position shown in FIGURE 6 (a) and the whole core-making and placing sequence is repeated, the squence being tuned to synchronise with the production and placing of a fresh mould in the line 4 to receive the new cores.

As mentioned earlier, the actual disposition of the coreblowing head could be different from that shown. Likewise the linkage that transfers the core-box part A from the blowing position to "the discharging position could take any one of a number of different forms. The coreblowing head could operate horizontally instead of vertically and this would simplify the transfer movement but the blowing process is less satisfactory.

Instead of being cured by gassing, the cores could be cured by heat, in which case the core-box wouldbe pro vided with suitable heating elements.

It will be understood furthermore that, although the invention has been described in conjunction with a particular automatic mould-making machine, the invention could equally well be applied to orthodox moulding equipment the only essential being that the moulds or mould-halves are brought in succession to a predetermined position for the insertion of the 'cores.

Iclaim:

1. A method of making cored casting moulds comprising the steps of forming a first double sided sand-mould with a mould surface on each of two opposite sides thereof, each of said mould surfaces forming a part of a casting cavity and at least one of them being in-the form of a depression in its respective side of the mould; blowing a core in a cavity of a core-box at a position displaced from said mould; moving at least a part of said core-box with said core to a position in which it lies adjacent to the mould with the core engaging in said depressions on one side of said mould; withdrawing said core-box part from said mould while simultaneously urging said corebox part and said core apart whereby to cause said core to remain in said depression in said mould; forming a second double sided sand-mould with a mould surface on each of two opposite sides thereof; moving said second mould to a position in which it completes said casting cavity within which said core remains; blowing a second core in a cavity of a core-box at a position displaced from said first and second moulds; moving at least a part of said core-box with said core to a position in which it lies adjacent to that side of the second mould remote from said first mould and with the core engaging in the depression on that side of said second mould remote from said first mould; withdrawing said core-box from said second mould while simultaneously urging said core-box part and core apart whereby to cause said core to remain in said casting cavity; forming a third double sided sandmould; and moving said third mould to' a position in which it completes said casting cavity of said second mould, the foregoing process being continued indefinitely with successive cores and moulds.

2. The method of claim 1 including the step of applying pressure to the cores to hold them in the casting cavities while said core-box parts are withdrawn.

3. The method of claim 2 wherein said pressure is applied by air.

4. A method of making cored casting moulds comprising the steps of forming a first double sided sand-mould with a mould surface on each of two opposite sides thereof, each of said mould surfaces forming a part of a casting cavity having therein a plurality of depressions blowing a plurality of cores in cavities of a core-box at a position displaced from said mould, said cavities having relative positions with respect to each other corresponding to the relative positions of the depressions in each of said mould surfaces, moving at least a part of said core-box with said cores to a position in which it lies adjacent to the mould with the cores engaging in said depressions on one side of said mould, withdrawing said core-box part from said mould while simultaneously urging said corebox part and said cores apart whereby said cores remain in said depressions in said mould, forming a second double sided sand-mould with a mould surface on each of two opposite sides thereof, moving said second mould to a position in which it completes said casting cavity within which said cores remain, blowing cores in a cavity of a core-box at a position displaced from said first and second moulds, moving at least a part of said last-mentioned core-box with said core to a position in which it lies adjacent tothat side of the second mould remote from said first mould and with the cores engaging in the depressions on that side of the second mould remote from said first mould, withdrawing said last-mentioned core-box from said second mould while simultaneously urging said core-box part and said cores apart whereby to cause said cores to remain in said casting cavity, forming a third double-sided sand-mould, and moving said third mould to a position in which it completes said casting cavity of said second mould, said foregoing process being continued indefinitely with successive cores and moulds.

5. Apparatus for making cored casting moulds comprising means for forming a double sided sand-casting mould having a mould surface on each of two opposite sides, each of said surfaces being a part of a casting cavity and having at least one depression therein, means for blowing at least one core in a cavity of a core-box at a position displaced from said mould, means for moving at least a part of said core-box with said core to a position in which it lies adjacent to the mould with the core engaging in said depression on one side of said mould, means for withdrawing said core-box part from said mould while simultaneously urging said core-box part and said core apart whereby said core remains in said depression in said mould, means for forming a second doublesided sand-mould with a mould surface on each of two opposite sides thereof, means for moving said second mould to a position in which it completes said casting cavity within which said core remains, means for blowing a second core in a cavity of a core-box at a position displaced from said first and second moulds, means for moving at least a part of said last-mentioned core-box with said core to a position in which it lies adjacent to that side of the second mould remote from said first mould and with the core engaging in the depression on that side of said second mould or remote from said first mould, means for withdrawing said last-mentioned coreboX from said second mould while simultaneously urging said core-box part and said core apart whereby to cause said core to remain in said casting cavity, means for forming a third double-sided sand-mould and means for moving said third mould to a position in which it completes said casting cavity of said second mould.

6. The apparatus of claim 5 wherein each of said coreboxes comprises upper and lower parts meeting in a horizontal plane and having at least one core cavity therein, a core-blowing head associated with said core-box, means for displacing said lower core-box part, complete with the core in the cavity thereof, from said blowing head to a position in which the upper horizontal face of said lower core-box part is vertical and is in face-to-face engagement with the casting cavity in the vertical face of said mould, and means for holding the core in the depression in said casting cavity as said lower core-box part is withdrawn.

7. The apparatus of claim 5, wherein each mould surface has a plurality of depressions therein, and wherein each core-box has a plurality of core-cavities therein corresponding in number and position to the depressions in said mould surface.

8. The apparatus of claim 5, wherein the means for urging said core-box parts and said cores apart comprise air jets.

References Cited UNITED STATES PATENTS 1,756,602 4/1930 Morris et al 2237 2,871,527 2/1959 Wallwork 222.0 3,060,534 10/1962 Enzenbacher 22-493 3,181,207 5/1965 Schaible et al. 2220 .T. SPENCER OVERHOLSER, Primary Examiner. MARCUS U. LYONS, Examiner. E. MAR, Assistant Examiner.

Claims

1. A METHOD OF MAKING CORED CASTING MOULDS COMPRISING THE STEPS OF FORMING A FIRST DOUBLE SIDED SAND-MOULD WITH A MOULD SURFACE ON EACH OF TWO OPPOSITE SIDES THEREOF, EACH OF SAID MOULD SURFACES FORMING A PART OF A CASTING CAVITY AND AT LEAST ONE OF THEM BEING IN THE FORM OF A DEPRESSION IN ITS RESPECTIVE SIDE OF THE MOULD; BLOWING A CORE IN A CAVITY OF A CORE-BOX AT A POSITION DISPLACED FROM SAID MOULD; MOVING AT LEAST A PART OF SAID CORE-BOX WITH SAID CORE TO A POSITION IN WHICH IT LIES ADJACENT TO THE MOULD WITH THE CORE ENGAGING IN SAID DEPRESSIONS ON ONE SIDE OF SAID MOULD; WITHDRAWING SAID CORE-BOX PART FROM SAID MOULD WHILE SIMULTANEOUSLY URGING SAID COREBOX PART AND SAID CORE APART WHEREBY TO CAUSE SAID CORE TO REMAIN IN SAID DEPRESSION IN SAID MOULD; FORMING A SECOND DOUBLE SIDED SAND-MOULD WITH A MOULD SURFACE ON EACH OF TWO OPPOSITE SIDES THEREOF; MOVING SAID SECOND MOULD TO A POSITION IN WHICH IT COMPLETES SAID CASTING CAVITY WITHIN WHICH SAID CORE REMAINS; BLOWING A SECOND CORE IN A CAVITY OF A CORE-BOX AT A POSITION DISPLACED FROM SAID FIRST AND SECOND MOULDS; MOVING AT LEAST A PART OF SAID CORE-BOX WITH SAID CORE TO A POSITION IN WHICH IT LIES ADJACENT TO THAT SIDE OF THE SECOND MOULD REMOTE FROM SAID FIRST MOULD AND WITH THE CORE ENGAGING IN THE DEPRESSION ON THAT SIDE OF SAID SECOND MOULD REMOTE FROM SAID FIRST MOULD; WITHDRAWING SAID CORE-BOX FROM SAID SECOND MOULD WHILE SIMULTANEOUSLY URGING SAID CORE-BOX PART AND CORE APART WHEREBY TO CAUSE SAID CORE TO REMAIN IN SAID CASTING CAVITY; FORMING A THIRD DOUBLE SIDED SANDMOULD; AND MOVING SAID THIRD MOULD TO A POSITION IN WHICH IT COMPLETES SAID CASTING CAVITY OF SAID SECOND MOULD, THE FOREGOING PROCESS BEING CONTINUED INDEFINITELY WITH SUCCESSIVE CORES AND MOULDS.

5. APPARATUS FOR MAKING CORED CASTING MOULDS COMPRISING MEANS FOR FORMING A DOUBLE-SIDED SAND-CASTING MOULD HAVING A MOULD SURFACE ON EACH OF TWO OPPOSITE SIDES, EACH OF SAID SURFACES BEING A PART OF A CASTING CAVITY AND HAVING AT LEAST ONE DEPRESSION THEREIN, MEANS FOR BLOWING AT LEAST ONE CORE IN A CAVITY OF A CORE-BOX AT A POSITION DISPLACED FROM SAID MOULD, MEANS FOR MOVING AT LEAST A PART OF SAID CORE-BOX WITH SAID CORE TO A POSITION IN WHICH IT LIES ADJACENT TO THE MOULD WITH THE CORE ENGAGING IN SAID DEPRESSION ON ONE SIDE OF SAID MOULD, MEANS FOR WITHDRAWING SAID CORE-BOX PART FROM SAID MOULD WHILE SIMULTANEOUSLY URGING SAID CORE-BOX PART AND SAID CORE APART WHEREBY SAID CORE REMAINS IN SAID DEPRESSION IN SAID MOULD, MEANS FOR FORMING A SECOND DOUBLESIDED SAND-MOULD WITH A MOULD SURFACE ON EACH OF TWO OPPOSITE SIDES THEREOF, MEANS FOR MOVING SAID SECOND MOULD TO A POSITION IN WHICH IT COMPLETES SAID CASTING CAVITY WITHIN WHICH SAID CORE REMAINS, MEANS FOR BLOWING A SECOND CORE IN A CAVITY OF A CORE-BOX AT A POSITION DISPLACED FROM SAID FIRST AND SECOND MOULDS, MEANS FOR MOVING AT LEAST A PART OF SAID LAST-MENTIONED CORE-BOX WITH SAID CORE TO A POSITION IN WHICH IT LIES ADJACENT TO THAT SIDE OF THE SECOND MOULD REMOTE FROM SAID FIRST MOULD AND WITH THE CORE ENGAGING IN THE DEPRESSION ON THAT SIDE OF SAID SECOND MOULD OR REMOTE FROM SAID FIRST MOULD, MEANS FOR WITHDRAWING SAID LAST-MENTINED COREBOX FROM SAID SECOND MOULD WHILE SIMULTANEOUSLY URGING SAID CORE-BOX PART AND SAID CORE APART WHEREBY TO CAUSE SAID CORE TO REMAIN IN SAID CASTING CAVITY, MEANS FOR FORMING A THIRD DOUBLE-SIDED SAND-MOULD AND MEANS FOR MOVING SAID THIRD MOULD TO A POSITION IN WHICH IT COMPLETES SAID CASTING CAVITY OF SAID SECOND MOULD.