WO2008107558A1

WO2008107558A1 - Static carousel

Info

Publication number: WO2008107558A1
Application number: PCT/FR2008/000076
Authority: WO
Inventors: Alfred Reiter; Eric Costantini
Original assignee: Cinetic Automation Sa
Priority date: 2007-01-22
Filing date: 2008-01-22
Publication date: 2008-09-12
Also published as: FR2911522B1; DE602008002053D1; FR2911522A1; EP2112961A1; FR2911521B1; FR2911521A1; ATE476271T1; EP2112961B1

Abstract

The invention relates to an automated production line for metal parts, that comprises at least equipments for preparing the molten metal, core preparation equipments, moulding equipments, and finishing equipments, characterised in that said equipments are fixed, and in that the production line includes a first polyarticulated casting robot (5) for the transport from the equipments for preparing the molten metal to the moulding equipments, a second polyarticulated robot (6) for transporting the assembled cores from the core preparation equipments to the moulding equipments, and a third stripping polyarticulated robot (7) for stripping the parts from the moulds once they have solidified and for transporting them to a downstream station.

Description

STATIC CARROUSEL

The invention relates to a new concept of automated production line for metal parts, in particular by gravitational casting. Automated production lines of metal pieces by gravity casting of the state of the art include:

- a set of machines for preparing mussels (shells, cores);

- Melting furnaces and / or maintaining the liquid metal; - A casting site whose function is to pour the liquid metal into the molds, and when the part is solidified, to extract it from its mold;

- various downstream installations (cooling, coring, demasseling, etc.) depending on the type of part produced and the desired level of finish.

Typically an installation of the prior art comprises a carousel which carries 4 to 8 molding equipment called shellers. European Patent No. 1626830 discloses a casting chain of the prior art, organized around a carousel. The shells consist of a frame that carries the different parts of the fixed or mobile mold (traps - drawers). The rotation of the carousel makes it possible to transport each sheller successively in front of each unit of work, among which is:

a unit for producing assembled cores;

- A remoulding unit which consists of placing the assembled core in the mold.

a casting unit for pouring the metal melt into the molds;

units for cooling the metal in the molds;

an extraction unit for extracting all the solidified metal and the cores.

In general, upstream, a buffer stock of cores connects the core production unit to the carousel. Downstream, there is a set of means for ensuring the final cooling and completion of the parts. Although adopted in most existing installations, this provision no longer responds appropriately to the requirements of modern production lines, particularly in terms of flexibility, ergonomics, maintainability and safety: s - the arrangement of shells on a carousel in rotation limits the possibilities of intervention and maintenance and makes dangerous the changes of molds and any intervention of the operators;

the replacement of a mold is impossible when the other molds are in the production phase; 0 - the possibilities of modulation of the cycle time depending on the piece produced are limited by construction;

- the concentration of equipment around the carousel creates an extremely congested area that does not facilitate maintenance operations.

- Finally, the implementation of the carousel, whose moving part generally weighs more than 30 tons, is expensive and requires to carry and distribute on the carousel all energies, including gas, water, electricity, and hydraulic fluids.

The object of the present invention is to overcome these disadvantages by proposing a production line using fixed workstations.

(while they were mobile in the carousel solution) and to make mobile the robots realizing the operations of rewinding, casting and extraction

(previously fixed). Properly implemented, this arrangement makes it possible to eliminate the drawbacks of the casting carousel and to offer a flexible and flexible industrial tool.

As such, the invention relates, in its most general sense, to an automated production line for metal parts comprising at least equipment for preparing molten metal, molding equipment, equipment for preparing cores, and equipment for finishing, characterized in that said mold preparation and finishing equipment are stationary, and in that the production line comprises a first poly-articulated casting robot (5) for transporting the molten metal to the equipment a second poly-articulated robot (6) for transporting cores assembled from core preparation equipment to molding equipment and a third poly-articulated extraction robot (7) for extracting mold parts after they have solidified and for transport to a downstream station . Preferably, the production line according to the invention comprises, in a path of movement of said robots, successively a first zone

(1) for the implantation of one or more equipment for preparing the molten metal, a second zone (2) for the implantation of a plurality of molding equipment and for the implantation of the equipment for preparing the cores (2A), a third zone (3) for the implantation of one or more finishing equipment for the molded parts, and a fourth zone for preparing the cores.

Advantageously, said robot moving path is a single-lane path, the first robot being movable between the molten metal preparation zone and the second robot, and the third robot being movable between the second robot and the zone of the robot stations. finish.

According to a first variant, said path of displacement is linear. According to another variant, said displacement path is arched, closed or circular. The production line according to the invention may comprise at least two equipment for preparing the molten metal loaded with metals of different natures.

The invention also relates to a process for the preparation of molded parts which comprises three main steps of extraction of the molded part, re-molding of the cores and casting of the metal, said steps being carried out by three mobile robots (5 to 7) between a zone for preparing the molten metal

(1), a molding zone (2) and a finishing zone (3).

It also allows to include manual operations (sampling for control, inspection, maintenance, small series) in optimal safety and ergonomic conditions.

The solution according to the invention consists in using three poly-articulated robots moving linearly (alternately in a circular path) to the ground.

Each robot is assigned to a particular operation: the first robot ("casting") transports the molten metal from the holding furnaces to the molds;

- the second robot ("remoulding") is used to transport the cores from a supply conveyor to the shells. - The third robot ("extraction") is used to extract the parts of the shellers after they are solidified and to transport them, either on the cooling mat or on an intermediate treatment station (finishing station, de-reuse machine). It also ensures the transfer of the part from said intermediate processing stations and the cooling mat. Depending on the constraints of cadence and cycle time, the functions of extraction and remoulding could be performed by a single robot equipped with 2 clamps or a device for changing clamps.

The robots circulate on the same rail to serve alternately the different machines arranged on either side of this rail (alternatively outside the circle formed by the rail), which are typically 6 in view of the time required to casting and solidification of the pieces. A different number of casting machines is possible, as one can imagine any kind of geometric configuration of these machines depending on the implementation constraints of the line.

The invention will be better understood on reading the description which follows, with reference to the appended drawings relating to nonlimiting examples of embodiment where:

- Figure 1 shows a schematic view of a production line according to the invention, in a linear configuration;

- Figure 2 shows a schematic view of a production line according to the invention, in a linear configuration, during the extraction phase of the molded part;

- Figure 3 shows a schematic view of a production line according to the invention, in a linear configuration, during the phase of depositing a molded part on a finishing equipment; - Figure 4 shows a schematic view of a production line according to the invention, in a linear configuration during the output phase of the molded part;

- Figure 5 shows a schematic view of a production line according to the invention, in a linear configuration, during the return phase at the beginning of a new cycle;

- Figure 6 shows a schematic view of a production line according to the invention, in a circular configuration;

- Figure 7 shows a schematic view of a production line according to the invention, in a circular configuration, during the extraction phase of the molded part;

- Figure 8 shows a schematic view of a production line according to the invention, in circular configuration, during the phase of depositing a molded part on a finishing equipment; - Figure 9 shows a schematic view of a production line according to the invention, in circular configuration during the output phase of the molded part;

- Figure 10 shows a schematic view of a production line according to the invention, in a circular configuration, during the return phase at the beginning of a new cycle.

Figure 1 shows a general view of the production line of molded metal parts according to the invention. The chain is organized in three main zones: - a first zone (1) of implantation of the furnaces (8),

a second zone (2) for implanting the molds,

a third zone (3) of finishing equipment.

A path (4) traverses these three zones (1 to 3), and allows the movement of three robots (5 to 7):

a first poly-articulated casting robot (5) for transporting the molten metal from the oven to the mold,

a second poly-articulated remoulding robot (6) for transporting the cores from a supply conveyor to the shells, - A third robot (7) poly-articulated extraction for extracting parts shellers after solidification and for transport to a downstream station.

The first zone (1) is intended to receive one or more furnaces intended for melting of the metal intended for molding. Each oven can process a different alloy bath.

This first zone (1) also comprises a ladle skin blowing station (9), intended to remove the alumina skin that forms, in contact with the air, in the ladle after pouring into the molds.

Depending on the type of oven, the first robot (5) draws in the oven using the ladle attached to the end of the articulated arm in the case of a direct-setting furnace, or takes the ladle previously filled with a dose of molten metal in the case of a metering furnace. The first robot (5) then moves to one of the shellers (10, 11, 12, 13, 14, 15) in the second zone (2).

The robot (5) then controls the displacement of the ladle above the mold to cause the filling of the latter according to a casting law specific to each part reference. Each law of casting is configurable in the control system of the installation. The size of the ladle and its level of filling are defined according to the weight of the piece and its various casting appendages.

The introduction of the liquid metal is mainly due to the gravity in the mold of the shellfish according to the principle of gravity casting. To facilitate this casting, and according to the applications, the sheller who carries the mold may be tilting.

The filling is achieved by the sole action of the weight of the metal, the mold must be designed so that the footprint in its entirety is filled.

The second zone comprises shellfish (10,11,12,13,14,15) carrying the different parts of each mold (20,21,22,23,24,25).

Each mold (20 to 25) has a pouring basin for filling. The feeding of a mold by gravity comprises 3 phases controlled by the first robot (5). 1 - First phase: Pouring into the pouring basin of the mold, according to a programmable casting law.

2 - Second phase: From this basin, the filling of the impression by the molten metal is carried out by the pouring down, the feed and attack channel. By penetrating into the mold the metal flushes the air by air drafts.

3 - Third phase: The masselottage, which serves to compensate the contraction of the metal of the part at the time of solidification.

In order to avoid cavities being created at the moment of this contraction, nourishing masses or reserves of liquid metal, called flyweights, are filled at the time of casting.

The second robot (6) moves in the zone (2) and (2A), between the shellers (10 to 15) and the nucleus preparation station (2A).

At these or these stations are presented already assembled cores or, as the case may be, parts of cores which will be assembled by the robot (6) before the removal operation in the concerned mold (20 to 25).

The third zone (3) may include the various finishing stations: the breaking of the cores to separate the piece (s) that has just been poured, the core of sand. It is therefore to break the core, for example on a vibrating table or manually, with instruments such as hammers or electric or pneumatic chipping hammers, sand removal and recycling, breaks jets to separate the room of different appendages casting, and heat and / or chemical treatments to improve the mechanical characteristics of the parts obtained in aluminum casting.

The operations performed by the robots (5 to 7) comprise three main steps:

- extraction of the molded part,

- remmoulage of the nuclei, and

- casting of metal. The three mobile robots on a linear axis, or on a circular axis evolve in the following order:

1 - articulated poly robot (7) for extracting the molded part,

2 - Articulated poly robot (6) for re-molding assembled cores, 3 - Articulated poly robot (5) for casting metal.

The extraction robot (7) and the remoaming robot (6) are stationed in the area (2A) and (3).

In a production cycle, the sequence of operations is as follows:

during the extraction phase of the molded part (FIG. 2), the casting robot (5) is waiting in the zone of the furnaces with the casting ladle stationed above the bath (8) or according to the case is ready to grab a ladle. The extraction robot (7) manipulates the molded part to extract it from the mold (22),

- The next step illustrated in Figure 3 is to remove the casting at the finishing station and results in the evolution of the extraction robot (7) in the finishing area (3).

The second remoulding robot (6) is positioned in front of the mold to be treated and deposits the cores. At the same time the first casting robot (5) draws in the furnace to fill the ladle, or as appropriate seizes a ladle.

the following step illustrated by FIG. 4 has for object the removal of the piece on the conveyor belt (30).

The remoulding robot (6) moves towards the zone (2B) ₁ followed by the casting robot (5) which is positioned in front of the shell maker (22) to be treated. In parallel, the extraction robot loads a finalized part (31) onto a conveyor, in general, for transfer to a cooling tunnel.

- The next step illustrated in Figure 5 is the return of the robot (5) to the furnaces. Simultaneously, the casting robot (5) returns to the zone (1) to blow the ladle. In parallel, the remoaming robot (6), followed by the extraction robot (7), is positioned in the zone of the next sheller to be treated. Figures 6 to 10 show an alternative embodiment in circular configuration. The equipment comprises a closed displacement path, in the described example of circular shape. Three poly-articulated robots (5, 6, 7) move on this circular path. These robots (5, 6, 7) can be positioned each in front of any one of the workstations. Each workstation has an area closed by a partition wall (102) with the station following an access door (101) whose opening is locked when the workstation is active. This access door (101) allows an operator to access the equipment arranged inside the workstation in a secure manner. A second access door (103) provided on the moving path side allows access to the arm of one of the robots. This door (103) is lockable when the workstation is idle, to allow maintenance operations safely.

Figure 7 shows a schematic view of a production line in circular configuration, during the extraction phase of the molded part.

Figure 8 shows a view of the production line, in a circular configuration, during the phase of depositing a molded part on finishing equipment.

Figure 9 shows a view of the production line, in circular configuration, during the exit phase of the molded part.

Figure 10 shows a view of the production line, in a circular configuration, during the return phase at the beginning of a new cycle.

Claims

1 - Automated production line for metal parts comprising at least equipment for preparing molten metal, molding equipment, equipment for preparing cores, and finishing equipment, characterized in that said equipment for preparing molds and are fixed, and in that the production line comprises a first poly-articulated mobile robot (5) for casting, for the transport of the molten metal to the molding equipment, a second mobile robot (6) poly- articulated for transporting cores assembled from core preparation equipment to molding equipment and a third poly-articulated extraction robot (7) for extracting mold parts after they have solidified and for their transport on a downstream station.

2 - A production line according to claim 1, characterized in that it comprises, in a path of movement of said robots, successively a first zone (1) for the implantation of one or more equipment for preparing the molten metal, a second zone (2) for the implantation of a plurality of molding equipment and for the implantation of the core preparation equipment (2A), and a third zone (3) for the implantation of one or more several finishing equipment of the molded parts, and a fourth zone of preparation of the cores.

3 - production line according to claim 2, characterized in that said robot moving path is a single-lane path, the first robot being movable between the molten metal preparation zone and the second robot, and the third robot being mobile between the second robot and the area of the finishing stations.

4 - production line according to claim 2 or 3, characterized in that said path of movement is linear.

5 - production line according to claim 2 or 3, characterized in that said path is arched, closed or circular. 6 - Production line according to at least one of the preceding claims, characterized in that it comprises at least two equipment for preparing the molten metal loaded with metals of different natures.

7 - production line according to at least one of the preceding claims, characterized in that it comprises only a first mobile robot (5) poly-articulated casting, for the transport of molten metal from the metal preparation equipment in fusion to the molding equipment, a second poly-articulated mobile robot (6-7) for transporting the cores assembled from the core preparation equipment to the molding equipment and for extracting the mold parts after that they are solidified and for their transport on a downstream station.

8 - Process for preparing molded parts, characterized in that it comprises three main steps of extraction of the molded part, remmoulage of the cores and casting of the metal, said steps being carried out by three mobile robots (5 to 7) between a molten metal preparation zone (1), a molding zone (2) and a finishing zone (3).