GB2057318A - Apparatus for manufacturing foundry cores - Google Patents

Abstract

The apparatus has means (7) for fastening upper and lower halves of core boxes together before entry to a heating chamber (10), means (11, 13) for unfastening them, means (14) for delivering finished cores and means (2, 3) for returning empty core boxes to a transfer table (4) for a further operational cycle. Each box has two horizontal rods (26) with conical elements (27) located in its bottom half which cooperate with two vertical bars (20) mounted on the top half and having at their bottom ends slots and conical orifices cooperating with the conical elements (27). <IMAGE>

Description

SPECIFICATION Apparatus for manufacturing foundry cores The invention relates to apparatus for manufacturing foundry cores in a heated chamber. The invention can be employed at automotive engineering, sanitary engineering, electrical engineering, machine building, and other industrial production works requiring production.

The invention provides apparatus for manufacturing foundry cores, comprising a supporting frame formed with two tiers, the bottom tier carrying a transportation means and transfer tables, and the top one, sand preparation and pressing mechanisms, a pusher with a crosspiece, a heating chamber, and mechanisms for disassembling the core boxes and delivering a finished core, the apparatus being provided with a device for fastening together halves of the core boxes, located before the heating chamber, and a device mounting behind the heating chamber and intended for unfastening the halves of the core boxes, each of the core boxes containing two horizontal rods with conical elements, placed in the bottom half of the core boxes and cooperating with the above devices for fastening and unfastening the core boxes, and two vertical rods secured to the top half of the core boxes and having at their bottom ends slots and conical orifices intended for cooperating with the conical elements of the horizontal rods.

It is advisable for the device for fastening the halves of the core boxes to comprise horizontal piston actuators hinged to the pusher crosspiece, and for the device for unfastening the halves of the core boxes to comprise a bracket with adjustable stops, mounted on the mechanism for disassembling the core boxes.

In operation the transfer table lifts a heated core box from the transportation means and delivers it to the pressing mechanism. The devices for fastening the halves of the core box act upon the horizontal rods thereof in a mannerthatthe conical elements of the horizontal rods enter the conical orifices of the vertical rods. This results in their wedging so that both halves of the core box are reliably fastened.

This operation eliminates the need for holding the halves of the core boxes together after pressing and substantially reduces the cycle of operation of the apparatus. The devices for fastening the halves of the core box are hinged to the pusher crosspiece, this preventing accidents should the mobile elements fail to return to initial position. The pressing mechanism packs sand prepared by the sand preparation mechanism, into the core box the core box is sealed and directly transferred by the pusher to the heating chamber which holds a number of other core boxes. As soon as a first core box is pushed into the heating chamber, the last core box is discharged into the zone of action of a mechanism for delivering a finished core which pulls the core box over to the transfer table.At the end of stroke, the horizontal rods of the core box meet the adjustable stops of the brackets mounted on the mechanism for disassembling the core boxes, and the core boxes are returned to initial position. This gives rise to a wedging action which unfastens the halves of the core box. The conical elements of the horizontal rods are moved out of the conical orifices of the vertical rods, and, simultaneously, the core box is unsealed. In this manner, the movement of the bore box upon the transfer table is put to good advantage, fulfilling two additional operations, the necessary length of movement being determined by the adjustable stops provided on the mechanism for disassembling the core boxes, which opens the core box, whereas the vertical rods are disengaged from the horizontal rods owing to the provision of slots.

Once the core is removed, the core box is reassembled by the mechanism for disassembling the core boxes and lowered by the transfer table upon the transportation means which returns the core box to the pressing mechanism station.

The multi-station apparatus is built in two tiers so as to minimize the width thereof and facilitate its siting on existing floor space. The apparatus roughly doubles the manufacturing capacity (as compared with conventional apparatus) and stabilizes the quality of cores. It should be emphasised that reliable fastening of the halves of the core box from the moment when fluid sand is packed therein to the moment when the core box is disassembled substantially reduces the pollution of the mechanisms and makes the core manufacturing process cleaner.

The invention will now be described by way of example with reference to the accompanying drawings, in which; Figure 1 is a general view of apparatus for manufacturing foundry cores; Figure 2 is a view along arrow A in Figure 1; Figure 3 is a section on line Ill-Ill in Figure 2; Figure 4 is a section on line IV-IV in Figure 3; Figure 5 is a section on line V-V in Figure 3; and Figure 6 is a view along arrow B in Figure 5.

The illustrated apparatus for manufacturing foundry cores includes a supporting frame 1 formed with two tiers, the bottom one carrying a transportation means 2 and transfer tables 3 and 4, and the top one carrying a sand preparation mechanism 5, a pressing mechanism 6, a pusher 7 with a crosspiece 8 (Figure 2) having piston actuators 9 hinged thereto, a heating chamber 10, a mechanism 11 for disassembling core boxes with brackets 12 and adjustable stops 13, and a mechanism 14 for delivering finished cores.

A core box 15 (Figures 2 and 3) contains a top half 16 and a bottom half 17 locked one to another by pins 18 and bushings 19. The top half 16 carries on diagonally opposite sides vertical rods 20 (Figure 4) with conical orifices 21 and slots 22 (Figure 6) and built-in gates 23 serving to seal the core box 15. The bottom half 17 incorporates ejectors 24 and bushings 25 intended as guides for horizontal rods 26 with conical elements 27. Sand is charged into the core box through inlet orifices 28. The apparatus operates as follows.

The transfer table 4 lifts the core box 15 from the transportation means 2 and delivers it to the pressing mechanism 6. The piston actuators 9 move the horizontal rods 26 of the core box 15 inside the bushings 25 so as to engage the conical elements 27 of the horizontal rods 26 in the conical orifice 21 of the vertical rods 20. This produces a wedging effect which locks together the halves of the core box 15.

The pressing mechanism 6 packs sand through the inlet orifices 28, the sand being supplied by the preparation mechanism 5. The gates 23 are moved to close the orifices 28, and the core box is sealed and directed by the pusher 7 into the heating chamber 10, which accommodates several other core boxes. As a fresh core box is charged into the heating chamber, a previous core box is discharged therefrom into the zone of action of the mechanism 14 for delivering finished cores. The mechanism 14 pulls the core box from the heating chamber 10 onto the transfer table 3, which is then in the top position.

At the end of a stroke, the horizontal rods 26 meet the adjustable stops 13 of the mechanism 11 for disassembling core boxes and are guided by bushings 25 into their initial position. This produces a wedging effect which opens the halves of the core box. The conical elements 27 of the horizontal rods 26 are moved out of the conical orifices 21 of the vertical rods 20. Simultaneously, the core box is unsealed, and its gates 23 return to their initial position.

The mechanism 11 for disassembling core boxes opens the core box, and the vertical rods 20 disengage themselves from the horizontal rods 26 owing to the slots 22. Once a core is pushed out by the ejectors 24 and removed from the core box, the core box is re-assembled and lowered by the transfer table 3 upon the transportation means 2, which moves it toward the transfer table 4. Another cycle of operation of the apparatus starts when the transfer table 4 moves upwa:- s together with the core box.

The apparatus described above provides a roughly double efficiency as compared with existing coremaking machines, while retaining high dimensional and geometric accuracies of cores.

Claims (3)

1. Apparatus for manufacturing foundry cores by pressing fluid sand into heated cores boxes, comprising a supporting frame formed with two tiers, the bottom tier accommodating a transportation means and transfer tables, and the top tier accommodating a sand preparation and pressing mechanism, a pusher with a crosspiece, a heating chamber, and mechanisms for disassembling core boxes and delivering finished cores, the supporting frame also carrying a device for fastening halves of the core boxes together, located upstream of the heating chamber, and a device for unfastening the halves of the core boxes, mounted downstream of the heating chamber, each of the core boxes being provided with two horizontal rods with conical elements, located in its bottom half and cooperating with the said devices for fastening and unfastening the halves of the core boxes, and two vertical rods secured to the top half of each core box and having at their bottom ends slots and conical orifices cooperating with the conical elements of the horizontal rods.

2. Apparatus as claimed in claim 1, wherein the device for fastening the halves of the core boxes comprises two horizontal piston actuators hinged to the crosspiece of the pusher, whereas the device for unfastening the halves of the core boxes comprises brackets with adjustable stops, mounted on the mechanism for disassembling the core boxes.

3. Apparatus for manufacturing foundry cores, substantially as described with reference to, and as shown in, the accompanying drawings.