GB2189417A - Automated line for production of castings - Google Patents

Abstract

An automated line for production of castings comprises production process units and a transport means for conveying casting moulds between these production process units. The transport means is made in the form of a closed overhead power- and-free conveyor (7) provided with a multitude of trolleys (8) with hangers (9) for accommodation of casting moulds (10). The hangers (9) are provided with heat shields (11, 12) disposed one over the other for independent vertical movement and a furnace (3) for calcining the moulds (10) and a unit (5) for cooling the castings have roofs with through longitudinal slots for passing the hangers (9) and water-cooled guideways which interact with the heat shields (11, 12) of the hangers when the hangers (9) pass through these units. Each hanger (9) is provided with a means (21) for accommodation of the casting moulds, hinged to the hanger (9) so that the center of gravity of the means (21) is disposed below the pivot of the hinged joint. <IMAGE>

Description

SPECIFICATION Automated linefor production of castings The present invention relates to a ceramic shell mould precísíon-investmentcasting and more particularly, to automated casting lines intended for calcining ceramic shell moulds, metal pouring and cooling of castings.

Thepresentinvention may be most advantageously employed for mass production of precision castings on automated flow casting lines, using burn-out and/or investment patterns and operating under conditionsofaflexible production readily readjustableformeeting different production process require merits At presentthe operations involving calcination of shell moulds, pouring of metal and cooling of castings are accomplished, using the following basic versions ofthe prodution processes:: (a) flasklesscalcination of ceramic shell moulds without a filling material and pouring of metal into the moulds withoutthefilling material; (b) calcination in flasks of ceramic shell moulds preliminarily bedded down in a cold filling material and pouring ofmetal into the moulds in thefilling material; (c) flaskless calcination of ceramic shell moulds followed by bedding them down in a hot filling material before metal pouring; (d) calcination in flasks of ceramicshell moulds without a filling material followed by bedding the shell moulds down in a hotfilling material before metal pouring.

Existence ofthe above-mentioned versions ofthe production process ensuring calcination of casting moulds, pouring of metal and cooling of castings and use ofthe respective versions of different installations and automated lines for calcination ofceramic shell moulds, pouring of metal and cooling of castings are caused by the fact that none ofthe known production lines can coverthe whole variety of casting nomenclatures and differences in used moulding materials, to provide combination of a high quality with a decrease in the manufacturing cost and to attain at the same time a high productivity.

Known in the prior art is a mechanized closed flow line for production of castings (cf. Investment Casting by Shklennik, Ozerov, Moscow, "Mashinostroenie", 1984, pp.345,346, Fig. 10.6), comprising an installation for moulding cold shells in a filling material in flasks, athrough calcining furnace, a casting roller tabie,acooling chamber, aflaskshake-outand a convayorfor return of empty flasks. The flasks are moved along the guide rails with the aid of pushers.

Location ofthe installation for moulding the shells in a filling material upstream of the calcining furnace and consequently the moulding ofthe cold shells in a cold filling material results in that the heating of the shell mouldsto a calcining temperature becomes a prolonged process and requires a substantial consumption of energy, as a greater portion ofthe heat is spent for heating the filling material and the flasks. When the entire mould is heated in a flask, it is the external layer ofthefiiling material which is heated first and while expanding at heating this layer compresses the shell mould and causes cracks and distortion ofthe mould geometric shape. Besides, the periodical heating of the flasks leads to premature failure thereof caused by cracks.As a result, the consumption of steel for repairing the flasks and replenishing the stock of flasks is substantially increased.

From the point of view of cutting down the spoilage of shell moulds, reducing the period of calcining the shell moulds and ensuring the economy of energy, a automated lineforcalcining the shell moulds, pouring of metal and cooling ofcastings embodied according to USSR Inventor's Certificate No. 231,747 is more effective and comprises a through furnace for calciningthemouldswithoutafilling material,a moulding mechanism, casting and cooling chambers, and a transport means for conveying the moulds in the sequence ofthe production process operations, made in the form of an overhead load-carrying conveyor whose principle of operation is based on a simultaneous movement of stopping of all the hangers disposed at a definite spacing.However, such a conveyorfeaturing a rigid kinematic connection cannot ensure the flexibility required for accomplishing all possible versions ofthe production process operations the duration ofwhich may be substantially different.

Wider engineering capabilities are inherent in an automated line for production of castings (cf. USSR Inventor's Certificate No. 768,537), comprising arranged in the sequence ofthe production process operations a unitforloadingceramicshell moulds, a calcining furnace, a moulding mechanism, a pouring unit, a cooling chamber and a transport means for conveying the moulds between the production process units. Used as a transport means is a car-type periodic-action conveyor made in the form of rail tracks on which the cars carrying removable pallets for accommodation of moulds are periodically conveyed. For passing through the calcining furnace a shell mould is placed in the pallet without being moulded in the filling material.After leaving the calciningfurnacethepalletwiththeshell mould is covered with an enclosure and moulded in the filling material by means of a moulding mechanism. Then the shell mould is delivered tothe pouring unit.

The automated line according to USSR Inventor's Certificate No. 768,537 may be used for different versions ofthe production processes dealing with calcination of ceramic shell moulds, pouring of metal and cooling of castings. The operating flexibility of this line is ensured bythe use of a car-type conveyor which has individual drives at separate production process stations. Depending on the production requirements,this conveyor makes it possible to retard or accelerate the movement of individual cars, to store upthecars beforetheshake-outoperationandto perform additional operations at the expense ofthe off-cycle time without reducing the installation pro ductivitywhich could not be achieved by the abovementioned installations provided with a rigid transport system.

Howeverthe design features ofthe cars andtheir drive system do not allow the production process to be quickly changed over fro one version to another one, do not allow a quick and simple introduction of changes in the layout ofthe production process units, and especially do not allowthetransportsystemto be extended to a fettling section which is desirable forfull automation ofthe production process. Because ofthe above-mentioned disadvantages the automated line according to USSR Inventor's Certificate No. 768,537 does not meetthe requirements of a modern multiple nomenclature mass production of precision castings.

In addition, operation ofthe installation according to USSR Inventor's Certificate No. 768,537 involves unnecessary economic losses resulting from a number of design features ofthe given installation. For example, servicing of thetransport system necessi tatesconstruction of spacious basement rooms lead ing to extra expenses. Calcination ofthe ceramic shell moulds is accompanied by excessive losses of heat energyspentfor heating of pallets in which the shell moulds are installed on a layerofsand. Besides, the periodical heating oftheflasks causes premature failure thereof because of cracking.This results in excessive consumption of high-temperature steel for repair ofthe flasks and replenishment oftheir stock.

The invention is aimed at providing such an automated lineforproduction ofcastings,the construction of which will possess wide engineering capabilities for effecting all known versions ofthe production process operations along with a high quality of castings.

This aim is attained by that in an automated line for production of castings, comprising arranged in the sequence of the production process operations a unit for loading casting moulds, a furnaceforcalciningthe casting moulds, a unit for pouring metal in casting moulds, a unitfor cooling castings in the moulds, a unitforunloading castings and a transport means for conveying the casting moulds between the production process units, according to the invention the transport means is made intheform of a closed overhead power-and-free conveyor having a continuously moving chain with pushers and a multitude of trolleys mounting the hangers for accommodation of casting moulds, provided with at least two heat shields disposed one over the other for independent vertical movement, and stops for braking and locking the trolleys in the sequence ofthe production process operations,while thefurnace for calcining the casting moulds and the unit for cooling the castings have roofs with through longitudinal slots for passing the hangers and are provided with water-cooled guideways interacting with the heat shields ofthe hangers when the latter are passing through these units, each hanger being provided with a means for accommoda- tion of casting moulds, hinged to the hanger so that the center of gravity ofthe means is arranged below the pivot ofthe hinged joint.

Such an embodiment ofthe automated line makes it possible to effectany layouts (includingturns, ascents and descents), to ensure a high travelling speed with minimum production losses of the cycle time which is of paramount importance, for example,forconveying the casting moulds from the calcining furnace to the pouring station, to combinethe conveying ofthe moulds with the production operations, for example, with heating of the moulds and cooling ofthe castings, to store up the moulds at the production process stations for an unlimited time and in an unlimited quantity, and to mount a multitude of the moulds on each hanger,forexample,fromoneto50 pieces, depending on the volume of a prepared alloy.

This also makes it possible to automatically accomplish the production process operations independent ly of one anotheratdifferentstations, andthe units associated with release of heat may be extended or shortened to a required length, depending on the production process requirements and productivity of the automated line.

It is desirable that in one of the preferred embodi ments ofthe automated line for production of castings and more particularly in the case of using an inexpensive moulding material such as for example, sand or pulverulent quartz, each means for accommodation of a casting mould should be made in the form of a box pallet with a bottom for receiving a filling material, and the automated line should be additional ly equipped with a means for heating the filling material and loading the palletswith a hotfilling material, disposed downstream of the rnace for calcining the casting moulds and provided with a through slot for passing the hangers, and a unitfor vibroramming ofthefilling material in the pallet, disposed downstream ofthe pallet loading means, while a unitfor cooling of castings should be made in theform of chambers disposed in tandem and intended for crystallization and cooling of castings, with a drum tilter installed between the chambers and intended for removal offilling material from pallets and provided with longitudinal slots for passing the power-and4reeconveyor hangers and means for riddling and conveying a removed filling material to the means for its heating.

Such an embodiment of the automated line makes it possible to use inexpensive and noncritical materials for production ofhigh-quality castings along with a high degree of automation ofthe production processes and a simultaneous decrease in the heat losses.

The unitfor unloading of castings may suitably be made in theform of a drum tilterfor removal of castings, provided with a spring-loaded plate mount ing avibratorand astationary plate secured onthe tilter body and provided with slots for passing the hangers, the spring-loaded and stationary plates being arranged oppositelyto each other on different sides ofthe conveyor hangers, and both the plates are adapted to interactwith a pallet on the hanger,while the plate mounting the vibrator is provided with a guide baffle.

Such an embodimentofthe unitforunloading of castings makes it possible to automate a labourconsuming and harmful production operation associated with release of substantial quantities of heat and dust, to ensure a guaranteed removal of castings and remainderofthefilling materialfromthepallets during an incomplete turn ofthetilterand at small differences in height, without using complicated transferfacilities.

The drum tilterfor removal offilling material from pallets may also be advantageously provided with a spring-loaded plate mounting a vibrator and a stationary plate secured on the tilter body and provided with slots for passing the hangers, disposed oppositely to each other on differentsidesoftheconveyour hangers, and both the plates should be adapted to interact with a pallet on the hanger, and the plate mountingthevibratorshould be provided with a guide baffle,whilethestationary plate should be provided with a grate cover having an actuator and pivotally secured to this plate which has slots for passing the hangers.

Such an embodiment ofthe tilter makes it possible to automate the operation of a rapid removal of hot filling material having a temperature of 600-900"C,to regulate the cooling rate of castings, to reduce surface decarburization of steel castings and thus to improve the quality of castings and atthe same time to perfect conveying operations at the expence of conveying the castings at a suitable heightand eliminating the pits and trestles, to shorten the path of conveying a hot filling material and to cut down the losses of heat in the process of conveying.

Besides, the power-and-free conveyor may be provided with an additional closed storing-up conveyortrack having a pallet removing means, associated with the closed overhead power-and-free con veyorby automatic track switches, a first ofwhich is installed upstream ofthe cooling chamber and a second one is installed downstream ofthe unit for unloading of castings.

Such an embodiment of the power-and-free conveyor makes it possible to provide minimal conveying and production process routes fortravelling of the pallets, viz. the presence of an additional closed storing-up conveyor allows distorted orfailed pallets to be removed without stopping the main production process conveyor, i.e. without loss of the cycle time and permitsrepairand maintenanceoperationsto be successfully carried out on the main conveyortrack.

It is desirable that in another embodiment of the automated line for production of castings, each meansforaccommodationofmouldsshould be made readily removable in the form of a platform with vertical and/orinclined pinsforarrangementofthe moulds.

Such an embodimentofthemeansforaccommoda- tion of the moulds makes it possible in some cases to calcine the moulds when the pouring cup thereof is facing down and to remove the investment patterns without melting them out preliminarilyand with a minimum ofthe pattern remainder left for burning.

It is desirablethat in still another embodiment of the automated line for production of castings, each meansforaccommodation ofmouldsshould be made in the form of a ceramic platform with a sand bed.

Such an embodiment ofthe means for accommodation of moulds makes it possible in some cases to calcinethe shell moulds made of high-grade moulding materials without a subsequent moulding of the shells in a hot filling materil and to pour metal in the obtained moulds without the filling material.

It is advantageous that in the automated line for production of castings, a calcining furnace should have the entrance and exitthereof communicated with each other by a circulating gas conduit.

Such an embodiment ofthe automated line makes it possible to rationally use the furnace heat and to provide uniform heating ofthe moulds.

The invention will now be described, byway of example, with reference to accompanying drawings, in which: Fig. 1 diagrammatically illustrates a general view of an automated line for production of castings, accord ing to the invention; Fig. 2 illustrates a hanger secured to an overhead power-and-free conveyor and means for accommodation of casting moulds on a platform.

Fig. 3 illustrates a top view ofthe platform for accommodation of casting moulds taken along the arrow A; Fig. 4 illustrates a view ofthe hanger in the direction of movement thereof, taken along the arrow B; Fig. 5 diagrammatically illustrates a sectional view taken along the line V-V of Fig. 1; Fig. 6 illustrates a sectional view of th e auto mated line taken on a pouring unit along the lineVI-VI of Fig.

1; Fig. 7 illustrates a sectional view ofthe automated line on a cooling chamberaiongthe lineVII-VII of Fig. 1; Fig. 8 is a sectional view ofthe automated line taken on a unitfor unloading of castings along the line VIII-VIII of Fig. 1; Fig. 9 diagrammatically illustrates a general view of anembodimentofthebutomated line; Fig. 10 diagrammatically illustrates a meansfor accommodation of casting moulds in a pallet; Fig. 11 diagrammatically illustrates a sectional view ofatilterfor removal of castings; Fig. 12 diagrammatically illustrates a sectional view ofatilterfor removal of filling material; Fig. 13 diagrammatically illustrates automated track-switches of an overhead power-and-free conveyor;; Fig. 14diagrammatically illustrates stops of hangers at the production process stations; Fig. 15 diagrammatically illustrates a sectional view ofthetilterforremovaloffilling material, revolved through an angle of 120"; Fig. 16 diag ram matica lly il l ustrates a side view of thetilterfor removal offilling material; Fig. 17 diagrammatically illustrates a means for arrangement of casting moulds on vertical pins.

Referring now to Fig. 1, there is diagrammatically illustrated a general view of an automated line for productionofcastings. Itwill beapparenttothose skilled intheartthatvariousembodimentsofthe automated line units and means and alterations in the relative position thereof may be readily made without departing from the spirit and scope ofthe invention as defined in the appended claims.

The automated line 1 for production of castings made according to the invention comprises a unit 2 for loading and a furnace 3 for calcining of casting moulds, arranged in the sequence of the production process operations. In a preferred embodiment of the invention the calcining furnace is made up of five sections 3a, 3b, 3c, 3d, 3e which differfrom one another by temperature conditions. Further follow a unit4forpouring metal inthecasting moulds,a unit (chamber 5) for cooling the castings in the casting moulds and a unit 6 for unloading the casting .A transport means integrates the above-mentioned units and is made in theform of an overhead power-and-free conveyor7 which propels a multitude oftrolleys 8 provided with hangers 9 (Fig. 2) accommodating casting moulds 10. The hangers 9 are provided with at least two.heat shields 11 and 12 disposed one above th e the otherforindependentvertical movement.The heat shields 11, 12 are.interacting with water-cooled guideways 13 and 14 (Fig. 1) made in width on bbth sides of a longitudinal slot 15 (Fig. 5) ofthe calcining furnace 3 (Fig. 1) for passing rods of the hanger 9 (Fig. 2). In the same way the heat shields 11 and 12 interact with the guideways of other units featuring an intensive release of heat, for example, with guideways 16 and 17 (Fig. 7) ofthe unit5for cooling the castings in the moulds. When the hangers are stored up the presence ofthe heatshields 11 and 12 makes it possible to devise a dual uniterrupted heat shield which substantially reduces the losses of heat and to preventthe units ofthetransport means 7 (Fig.

1) from being heated in excess ofthe permissible limits. For stopping and locking the trolleys 8 in the sequence ofthe production process operations, there are installed stops 8a, 8b, 8c, 8d, 8e the number of which is governed by the numberof halts ofthe hanger necessaryforaccomplishing the production process operations or by the need for storing up the hangers. The hauling trolleys 8 are put in motion by means of pushers 18 (Fig. 2) secured on a chain 19 of the power-and-free conveyor r provided with a combined take-up and drive station 20 (Fig. 1).

Each hanger 9 (Fig. 2) is provided with a means (platform 21 foraccommodation ofthe casting moulds 10, coupled to the hanger with the aid of a hinged joint22sothatthe centre of gravity ofthe casting moulds and the means (platform) 21 for accommodation thereof is below the pivot ofthe hinged joint.

The automated line is provided with an automatic control system. The overhead power-and-free conveyor 8.(Fig. 2) employed in the automated line comprises a hauling track with a hauling chain 19 mounting pushers 18 arranged with a preset spacing and a load-carrying track 23 disposed in parallel with the hauling track.

The load-carrying track 23 mounts a head trolley 24 and an endtrolley25 hinged to each other bymeansof a coupling 26. Hinged to the head trolley 24 are a front stop 27 adapted for coming in contactwith the pusher 18 and forturning clockwise, and a rear stop 28 adapted forturning counter-clockwise. The head trolley 24 has a counterweight 29 with a swing jaw 30 which make up a receiving slot, and the reartrolley 25 mounts a lever 31 adapted to enterthe receiving slot when thetrolleys are coupled.

The coupling 26 has two axles 32 (Fig. 2,4) arranged exactly in a horizontal position relative to the conveyor track and the hanger 9 (Fig. 2) is secured on these axles with the aid of a plate 33 (each hanger on the conveyor track is provided with an individual pair of trolleys).

The plate 33 has radiused slots 34 which atthe top terminate in precisely bored semiholes suited to the size ofthe axles 32.

By means of a traverse 35 (Figs. 2,4) and two rods 36 the platform 21 is pivotally connected to the plate 33 through the medium of a hook 37 (Fig. 2) having an open jaw. The lower shield 11 with a heat-insulating coating adaptedforvertical movement is suspended from the tranverse 35 on the underside by means of flexible ties (chains), and the upper shield 12 with a central slot for receiving the traverse 35 is freely seated on a supporting plate 38 (Fig. 4) above the traverse 35 in parallel with the lowershield 1 i,The shield 12 is adapted for vertical movement and is also provided with a heat-insulating coating.The shields 11,12 (Fig. 2) are provided with entry bent-up ends for convenience in joining. Depending on the dimensions thecasting mouldsmaybearrangedontheplatform 21 in one row 1 Oa (Fig. 3) or in a multitude of rows 10b.

The platform 21 is rated in size for accommodation of from3to 30 casting moulds.

The calcining furnace 3 (Fig.1) of a multiple-zone type is provided with a gas or other heating means (not shown). Afirst zone 3a has no burners and may be heated with a hot air delivered to each flaskwith the ceramic mould block (not shown) by means of a fan through a special circulating gas conduit and a distributing system.

The longitudianl slot 15 (Fig. 5) for passing the hangers 9 is provided in the roof ofthe furnace 3 throughoutthe entire length thereof.

Further in the sequence of the production process operations follows a pouring station the embodiment ofwhich depends on the productivityofthe automated line, kind ofcastingsto be obtained and onthe method of metal pouring. In a simple embodiment, as is illustrated in Fig. 6, it is essentially a pouring station 39equippedwitha pouring ladletransportation system.

Further in the direction of the conveyor movement followstheunit5forcooling of castings which is essentially a chamber with a longitudinal slot made in the roofthereoffor passing the hangers 9. The heat shields 11,12 slide along the guideways 16, 17. The chamber is also provided with an exhaust ventilation system (not shown); a forced ventilation and a water sprinkling system may also be employed.

Mounted atthe exit ofthe cooling chamber is a unit for removal of castings which may be made in the form of known manipulators ortilters; one embodi mentthereofwill be disclosed herein below.

In the automated line 1 for production of castings, the shell moulds 10 are loaded on the platform 21 in the unit 2 by an operator. After installation ofthe moulds (from 3 to 30 pieces on one platform) the stop 8a with a lock is disengaged and the platform 21 with the moulds 10 is fed intothefurnace 3 graduallyfilling it up to the stop 8b. After the furnace 3 is completely loaded the hangers 9 will be stored up beforethe furnace 3 on a section ofthe conveyor7 which is controlled by sensors (not shown) ofthe control system. The furnace 3 is made up of sections (3a, 3b, 3c, 3d, 3e) the number of which is governed by the production process time and productivity of the automated line.

To provide for a more uniform heating and eco nomy of heat, the sections ofthe furnace may be equipped with conduits through which a hot gas will be circulated.

Afterthe ceramic moulds are calcined and provided the metal and the ladle are ready, the stop 8b is disengaged and thetrolleys 8 arefed one byonefor pouring uptothe stop 8c. The trolleys 8 are fed for pouring as required or automatically at definite time intervals. The trolleys are conveyed from the pouring station to the cooling unit5bytheoperatoror automatically. In the cooling unit5the hangers 9 are stored up beginning with thestop8d and are keptiri the chamber during a time period required for crystallization ofthe castings. Then the castings are unloaded by the unit 6 (Fig. 8) for unloading of castings.

If ordinary quartz sands are used as refractory materials, it is preferred to employ an alternate embodiment ofthe automated line illustrated in Fig. 9.

In this case, each means for accommodation of a casting mould is made intheform ofa box pallet 40 (Fig. 10) with a bottom for receiving a filling material.

Therefore,theautomated line41 (Fig. 9) is additionally provided with a means 42for heating thefilling material anda means 43for loading the pallets40with the hot filling material, and both means are disposed downstream of thefurnace 3forcalcining the casting moulds 8 and are also provided with a through slot for passing the hangers andwithaunit44forvibroram- ming the filling material in the pallets, disposed downstream ofthe pallet loading means.In this case the unitforcooling of castings is made in the form of chambers 45 and 46 disposed in tandem and intended respectively forcrystallization and cooling of castings, and a drum tilter47 provided with a longitudinal slot 48 for passing the hangers is disposed between the chambers 45 and 46, and is intended for removal of the filling material from the pallets. The chambers 45 and 46 used respectivelyforcrystallization and cooling of castings are provided in much the same way asthe calcining furnace 3 with longitudinal slots for passing the hangers 9 ofthe power-and-free conveyor 7, while the tilter47 has a means 49 for riddling and conveying the removed filling material to the means 42 for its heating.

The unit 6 for unloading of castings may suitably be made in theform of a drum tilter 50 provided with a bath 51 for sprinkling of castings, a spring-loaded plate 52 (Fig. 11) with a vibrator 53, and a stationary plate 54 secured on the tilter body and provided with slots 55 for passing the hangers 9. The spring-loaded and stationary plates 52,54 are disposed oppositely to each other on different sides ofthe conveyor hangers 9, and both the plates are adapted for interaction with the pallet 40, while the plate 52 with the vibrator 53 is provided with a guide baffle 56.

The automated line may also be provided with a unified drum tilter47 (Figs. 9,12) for removal of filling materialfrom the pallets, made similarlytothe drum tilter 50for removal of castings and also equipped with the spring-loaded plate 52 with the vibrator 53 and the stationary plate 54 secured on the tilter body and provided with the slots 55 for passing the hangers 9The spring-loaded and stationary plates 52,54 are also secured oppositely to each other on different sides ofthe conveyor hangers 9, and are adapted for interacting with the pallet 40, while the plate 52 with the vibrator 53 is also provided with the guide baffle 56. However, in contrast to the tilter 50 (Fig. 11) for unloading ofcastings,thetilter47 (Fig. 12)forremoval offilling material from the pallets is additionally provided with a grate cover 57 and its actuator 58, pivotally secured on the stationary plate 54 by means of a hinged joint 59.

It is likewise desirable thatthe automated line in additon to the main transport means, viz. the closed overhead power-and-free conveyor 7 (Fig. 9) should be provided with an additonal closed storing-up conveyortrack60with a pallet removing means 61 associated with the main power-and-free conveyor by means of automatic track switches 62 and 63, one of which, viz. the facing switch 62 is disposed upstream ofthe cooling chamber and the other one, viz. the trailing switch 63 is disposed downstream ofthe unit2 for unloading of castings.

Referring now to Fig. 9, there is illustrated an alternate embodiment ofthe automated line. The line comprisesthe calcining furnace 3, the means 43for loading palletswith a hot filling material,the unit 44 forvibroramming ofthefilling material,the unit4for metal pouring, the chamber 45 for crystallization of metal, the drum tilter 47 for removal of the filling material,thecooling cham ber 46 and the dru m tilter 50 for removal of castings, arranged in the sequence ofthe production process operations. The overhead power-and-free conveyor7 with the hangers 9 (Fig. 12) carrying the pal lets 40 with the ceramic mould blocks passes through all the above-mentioned units.On a section between the entrance of the cooling chamber 46 and the exitof the tilter 50 the conveyor is provided with the closed storing-up conveyortrack 60 associated with the main conveyor track by the facing switch 62 and the trailing switch 63 made in the form of a pivotally secured switch tongue 64 (Fig. 13)with an actuator 65. The pallet removing means 61 (Fig. 9) is mounted on said storing-up conveyortrack60. The automated line is provided with a manipulator6for removal of castings unloaded from the drum tilter 50 onto transport means (not shown).The automated line is also provided with additional stops 67-71 made in the form of a driven gate 72 (Fig. 14) disposed respectively at the exit of the furnace 3, at the station of the means 43 for loading of pallets with a filling material, atthestation ofthe unit44forvibroramming, atthe station of the tilter 47, atthe exit of the cooling chamber 46 and in the pallet removing means 61.

In the automated line illustrated in Fig. 9 the calcining furnace 3,the unit4for metal pouring, the chamber 45 for crystallization of castings, the powerand-free conveyor7 with the hangers 9 are analogous in principle to the units illustrated in Fig. 1 and described in detail herein before.

The means 42 for heating the filling material and the means43forloading palletswith a hot filling material are essentially a lined bath disposed between the two parallel tracks of the conveyor so that one of its tracks passing out ofthe furnace 3 crosses the roof which covers the bath and has a through slot for passing the hangers, similarto the slot 15 (Fig. 5).

The heating bath is filled with a refractory sand material. Mounted on the bath bottom is a tubular manifold connected to a natural gas supply source (not shown). The manifold creates a fluidized layer in the bath. Provided in the bath body in the direction of movementoftheconveyor7 are ports73 and 74 intended respectivelyfor letting theflasks in and out, andthemeans43forloadingpalletswitha hotsand.

One ofthe bath side walls has a loading port75for delivery of a refractory filling material from the drum tilter47. The unit44forvibroramming of the filling material is installed in the sequence of the production process operations attheexit ofthe heating bath. The unit 44 comprises a vibrator and a device for regulating the degree of sand ramming in the pallet 40 (Fig. 10) to avoid breakage ofthe moulds 10.

Installed at the exit of the crystallization chamber 45 (Fig. 9) and coaxially therewith is the drum tilter 47 (Figs. 9, 12) intended for removal ofthe filling material and provided with the th rough slot 48 for passing the hangers9,and ports for letting the pallets40 in and out.

The drum tilter47 (Fig. 12) is designed for removal of a filling material from a pallet and essentially consists oftwo rims 76,76' (Figs. 12,16) secured by longitudinal braces 77 (Fig. 12), 78 and 79. Secured to each ofthe rims is the end ofthe chain of a chain transmission 80 associated with a drive. Fastened by means of the braces 78 and 79 is a supporting plate on which the vibratory impact spring-loaded plate 52 with the vibrator 53 is secured by means of springs 81.

The plate 52 is designed fortransmitting the impact vibration to the pallet 40 on the hanger 9. Secured on said plate 52 is the dumping guide baffle 56 the end of which atturning ofthetiltersets up (Fig. 15) flush with a riddling means (vibrating chute) 49 connecting it with the loading port 75 (Fig. 9) for delivery ofthe filling material in the means 42 for its heating.

Thestationary counter-impact plate 54 (Fig.12) 12) is disposed diametrically opposite to the plate 52 and is secured by the brace 77. The drum body is supported by rollers 82,83,84 and provided with an adjusting roller 85. The hinged grate cover 57 designed to prevent casting from falling out is pivotally secured to the plate 54forangularturning. The grate cover57 is pivotally associated with the actuator 58 which is also pivotally secured to the drum body. The plate 54and the grate cover 57 are provided with slots for passing the rods 36 (Fig. 10) ofthe hangers. Thetilter isturned by means of a drive 86 (Fig. 16).

Disposed further in the direction of movement of theconveyor7 (Fig. 9) is the through type cooling chamber46 (Fig.7) with a through slot made in the roofthereoffor passing the hangers. The chamber 46 is equipped with a ventilation system (not shown) and is made similarly to the crystallization chamber45.

The drum tilter 50 (Fig. 9) for removal of castings is installed at the exit ofthe cooling chamber 46. The drum tilter 50 is similar in design to thetilter47, howevertheformeris not provided with the grate cover 57 (Fig. 12) andtheactuator58.

The pallet removing means 61 (Fig. 9) arranged on a branch ofthe main track of the conveyor 7 is essentiallyaforksecured on a driven carriage (not shown) and adaptedforvertical reciprocating motion.

The fork has an inclination corresponding to the inclination ofthe jaw of hooks 87 (Fig. 12) ofthe hanger 9.

The automated line operates in the following way.

The conveyor 7 (Fig. 9) is provided with the unit 2 for loading the ceramic moulds 10 (Fig. 10) in theflasks of the pallet 40. After the moulds are loaded the operator disengages the stop 8a (Fig. 9) and the hangers 9 with the moulds lOarefedin thefurnace 3, gradually filling it. When the furnace is completely charged the hangers will be stored up infrontofthefurnaceon a section ofthe conveyor 7 under the control of sensors (not shown) ofthe control system. When a preset number ofthe hangers are stored up in front ofthe furnace 3the pouring station ofthe unit4 receives a signal allowing the hangersto be fed for metal pouring (automatic mode).At the same time the stop 8b is disengaged and the pushers8 (Fig. 2) of the conveyor hauling track 19 engages the hanger 9 and conveys itto the stop 67 of the means 43 for loading the pallets with a filling material.

After the flask is loaded with the filling material (registered by the time relay ofthe control system) the stops 8b, 67 and 68 are disengaged. As a result, a next flask is conveyed from the furnace 3 into the means 43 for loading the flasks with a filling material and the loaded flask is fed in the unit44forvibroramming of the filling material. Then said stops are again engaged, the flask is locked (notshown) and the vibratory plate is advanced to the flask. The time of ramming is registered by the time relay of the control system (not shown). After the ramming process is completed the command is again received for disengagement of the stops 8b, 67 and 68. As a result, the flasks are again moved one by one from station to station.This alternation of the flasks continues until the operatoratthe station ofthe pouring unit4stops this movement by depressing the stop button ofthe control system. The stop 8b blocks the furtherfeeding of the flasks from the calcining furncefor moulding.

The moulded flasks are fed in succession to the station ofthepouring unit4.Thenumberofflasksatsaid station is regulated by the operator. Afterthe metal pouring thestop 8c is disengaged and thefilled mould is fed in the crystallization chamber45which is gradually charged with theflasks carrying thefilled moulds. Upon crystallizationtheflask is fed in thetilter 47. At the same time the stop 8d is disengaged and the flask is accurately locked in the tilter47. After the flask is locked the stop 8d is once again engaged. Then the tilter47 is switched forturning by means of the drive 86 (Fig. Fig.16).The fibrato r 53 (Fig. 12) andthevibrating chute 49 (Fig. 15) are simultaneously switched into operation. The tilter 47 is turned through 120 . As a result, the grate cover 57 (Fig. 12) turns and covers the flask so that the casting is prevented from falling out and onlythefilling material is allowed to pour out of theflask.Thefilling material is returned alongthe vibrating chute 49to the bath of the means 42 for a repeated heating and for loading intheflask. Inthe process of vibration the plate 52 strikes the flask, thereby contributing to a rapid removal ofthe filling material. Due to such a design the conveying vibrating chute 49 is arranged with a small difference in height.

Operating time of the vibrator 53 is controlled by the time relays ofthe control system. Then the tilter 47 is reversed and the stop 69 (Fig. 9) is disengaged. The grate cover 57 (Fig. 12) is returned in the original position. Furthertheflaskwith the casting passes to the cooling chamber46 (Fig. 9) and a next hanger is received from the crystallization chamber 45, as the stop 69 is disengaged simultaneously with disengagement of the stop 8d. After the flask with the casting has cooled the stop 70 is disengaged and the flask is fed in the tilter 50 up to the stop 88 (engaged). The stop 70 is engaged, thereby preventing a nextflaskfrom passing out ofthe chamber 46.The flask is locked in the tilter 50 which togetherwith the vibratory impact plate is switched into operation similarly to the tilter 47.

The casting passes onto an intake tray from which it is removed by the manipulator 66 and transferred further for mechanical treatment. Then the tilter 50 is reversed, the stop 88 is disengaged and an empty flask is delivered to the station oftheflask loading unit 2 up to the stop 8a. Then the cycle is repeated.

If it is required to replace flasks (for repair, and so forth) the trailing switch 63 is closed and the flasks pass from the tilter 50 to the storing-up conveyor track 60, where from the are delivered to the removing means 61 uptothestop71.

In the removing means 61 the fork is raised by the carriage (not shown) and removes the flask from the hooks 87 (Fig. 12) ofthe hanger 9. Then the fork together with the removed flask is lowered and the flask is taken away. At this station repaired or new flasks are suspended from said hooks in the reverse sequence. Then the stop 71 (Fig. 9) is disengaged and the facing switch 62 is opened, and the flask is passed on the main track ofthe conveyor7towardsthe chamber46.Aftera required numberoftheflasks have been passed, the stop 71 is engaged and the facing switch 62 closed.

Thetrolleys are stored up intheform ofan uninterrupted row in the following way. Using any gate 72 (Fig. 14) ofthe stop, block the movement of the firsttrolley, then the pusher 18 (Fig. 2) brings a next trolley to the first one. As a result, the lever31 ofthe preceding trolley enters the slot ofthe successive trolley, formed by the counterweight 29 with the swing jaw30. Furthercoupling ofthetrolleysis accomplished in thesimilarway. In the process of storing up the uppershield 12 and the lowershield 11 of the hangers are joined by their entry ends with the successive shields, thereby forming a solid roof.In this case the lowertier of shields bears on the top of the furnace, the crystallization or cooling chambers covering the open slot in the roof thereof, while the uppertier of shields protects the hauling track 19 and the load-carrying track 23 ofthe conveyor 7 against heat radiation, thereby preventing seizing and premature wear of the tracks and also reducing the heat tosses.

Embodiment of the cooling chamber in the form of two chambers: the crystallization chamber45 and the cooling chamber 46 made it possible to cutdown their length and energy consumption, as in thefirst chamberwherein the process of crystallization takes placetheflaskcontainsthefilling material, while in the cooling chambertheflaskwith the casting is rapidly cooled in the absence ofthe filling material. Such cooling conditions also eliminate decarburization of the castings, practically excluding rejects caused by decarburization. The need for a filling material is substantially reduced and the service life of flasks is also increased.Separate removal ofthefilling material and castings makes it possible to return the hot filling material (t =700-800 C) to the installation for its moulding in the flask, thereby reducing the consumption of energy for heating. Thefilling material may be removed from the flasks after the crystallization of castings is completed.

The vibratory plate 52 introduced in thetilters sets up the impact vibration transmitted to the flask which facilitates removal of the filling material and also effectively cleans the castings from the burnt-on sand.

When storing upthe hangers the shields 11 and 12 provided thereon make it possibleto setup an uninterrupted shield the lowertier of which covers the through slot in the calcining furnace and in the crystallization and cooling chambers, thereby reduc ing the losses of heat a nd the u pper tier protects the conveyor movable elements from the thermal effect.

Embodiment of each of the hangers with two axles 32 makes it possible to accomplish, without any seizing, complicated vertical manipulations with the hangers when they are conveyed through the production process units.

Provision ofthe dumping guide baffles 64 in the filters makes it possible to dispense with pits. All the basic production process equipment of the automated line is arranged on one storey.

The proposed automated line may also be operated without using a filling material for which purpose it is necessaryto disconnect from the control system the means 43 for loading of flasks with filling material, the unit44forvibroramming offilling material and the drum tilter47 for removal offilling material.

There are fairly frequent cases in practice when the pattern compound is removed (melted orburned out) from the moulds in furnaces, in which case the moulds are arranged as illustrated in Fig. 17 with the pouring cup facing down. It is preferred that in the automated line an embodiment of the means for accommodation of moulds should be made readily detachable in the form of a platform 89 with vertical and/or inclined pins 90.

The automated line operates in much the same way as the line described with a reference to Fig. 1.

Thus an embodiment ofthe automated linefor production of castings disclosed hereinabove and other possible embodimaents thereof make it possible to use the units of series production, to arrange them for obtaining differentve,rsions in compliance with a given layout and productivity and to effectthe most rational layouts with a minimum of expenditures.

Claims (9)

1. An automated I i ne for production of castings comprising arranged inthesequenceoftheproduction process operations a unitfor loading casting moulds, a furnace for calcination of casting moulds, a unitfor pouring of metal into casting moulds, a unit for cooling of castings in the casting moulds, a unit for unloading of castings and atransportmeansfor conveying the casting moulds between the production process units,wherein thetransport means is made in the form of a closed overhead power-and-free conveyor having a continuously moving chain with pushers and a multitude oftrolleyswith hangers for accommodation of casting moulds, provided with at least two heat shields disposed one overthe otherfor independent vertical movement, and stops for braking and locking the hangers in the sequence of the production process operations, and the furnace for calcining the casting moulds and the unitforcooling the castings have roofs with through longitudinal slots for passing the hangers and water-cooled guideways interacting with the heat shields ofthe hangers when the hangers pass through these units, each hanger being provided with a means for accommodation of the casting moulds, hinged to the hanger so that the center of gravity of the means is disposed below the pivot ofthe hinged joint.

2. An automated line as claimed in Claim 1, wherein each means for accommodation of casting moulds is made in the form of a box pallet with a bottom for receiving a filling material and the automated line is additionally equipped with means for heating the filling material and loadingthe hot filling material into the pal lets, installed downstream ofthe furnace for calcining the casting moulds and provided with a through slot for passing the hangers, and with a unitforvibroramming of the filling material in the pallet, disposed downstream of the means for loading the pallet, and the unit for cooling of castings is made in the form of chambers disposed in tandem and intended respectively forcrystalliz,ation and cooling of castings and a drum tilter disposed between the chambersfor removingthefilling material from the pallets and provided with longitudinal slots four passing the hangers ofthe power-and-free conveyor and equipped with means for riddling and conveying the removed filling material to the means for its heating.

3. An automated line as claimed in Claim 2, wherein the unitfor unloading of castings is made in the form of a drum tilterfor removal of castings, provided with a spring-loaded plate with a vibrator and a stationary plate secured on the tilter body and provided with slotsforpassing the hangers, the spring-loaded and stationary plates being disposed oppositely to each other on different sides of the conveyor hangers, and both the plates being adapted to interactwith the pallet on the hanger, while the plate with the vibrator being provided with a guide baffle.

4. An automated line as claimed in Claim 2, wherein the drum tilterfor removal ofthe filling material from the pallets is provided with the springloaded plate with the vibrator and the stationary plate secured on the tilter body and provided with the slots for passing the hangers, disposed oppositely to each other on different sides of the conveyor hangers, and both the plates are adapted to interact with the pallet on the hanger, while the plate with the vibrator has the guide baffle and the stationary plate has a grate cover with an actuator, and is pivotally secured to this plate provided with the slots for passing the hangers.

5. An automated line as claimed in Claim 2, wherein the power-and-free conveyor is provided with an additional closed storing-up conveyor track having a means for removal of pallets and associated with the power-and-free conveyor by automatic track switches, a first of which is disposed upstream of the cooling chamber and second one, is disposed downstream of the unit for unloading of castings.

6. An automated line as claimed in Claim 1, wherein each meansforaccommodation of a casting mould is made readily removable in the form of a platform with vertical and/or inclined pins forarrangementofthe moulds.

7. An automated line as claimed in Claim 1, wherein each means for accommodation ofthe casting moulds is made in the form of a ceramic platform with a sand bed.

8. An automated line as claimed in any ofthe preceding Claims, wherein the calcining furnace has its entrance and exit communicated with each other through the medium of a circulating gas conduit.

9. An automated line as claimed in any of the preceding Claims, substantially as herein before describedwith reference to and as illustrated in the accompanying drawings.