Double carriage for automatic tool change in core making machines for casting

Abstract: A double carriage has been prepared for automatic tool change in core making machines for casting, where there are two sets of motorized rollers capable of receiving and expelling these tools; a carriage where there is a rolling frame, with wheels that are motorized by means of a reduction motor, where there is another reduction motor in each of the two operative sectors which activates the corresponding group of rollers, through an intermediary transmission shaft; in addition the carriage embodies handling devices for the tools in order to permit and facilitate their periodic cleaning. These devices consist of a support on which a tipper arm is assembled, which is activated by a hydraulic cylinder; on this arm there is also a plate, on guides, which contains clamps to secure the box of bores; the plate is moved by a hydraulic cylinder; this structure is a simple one when the carriage is used for boxes of cores of vertical opening and double when these are of horizontal opening.

Description: This invention refers to a double carriage for automatic tool change, in core making machines for casting according to the preamble of claim 1. The purpose of such a carriage is evidently to collect from the machine any jigs or tools that have already been used, and replace them with new ones, in an fully automatic performance. ANTECEDENTS OF THE INVENTION. In any core making machine for casting it is clearly essential to replace the tool at the end of each work process corresponding to obtaining a certain core for casting. The tools or boxes of cores are in themselves heavy tonnage parts, which create problems of handling during transportation, and different solutions are used, ranging from bridge cranes to different kinds of motorized carriages, for the obvious purpose of transferring the tools from the corresponding warehouse to the machine and vice versa. Any of these solutions, irrespective of their more or less structural complexity, presents the fundamental problem that it is impossible to establish an automatic control system for changing tools, and the work process calls for an important manual participation. For the tool change, in core making machines for casting, are used carriages wherein are established two sets of rollers being qualified to receive, either simultaneously or not, respective tools or core boxes, being said carriages properly motorized for achieving the access and further ejection of the tools to the carriage. These carriages seem to be useful by their function but very early carriages with respect to the adaptation possibilities to the transported tools or implements, being used as simple transport tables. In order to overcome this problem, the applicant is also holder of Spanish patent application ES.8602461, that was withdrawn by the own titular before its publication and which describes a plant for changing tools in core blower machines, which permits the tool change to be carried out in a fully automatic way. However, in the solution which was offered in that application, although the required objectives were reached, two important problems nevertheless remained: on the one hand, the carriage that was used as means for transporting the jibs is structurally complex and consequently expensive, and on the other hand no means are envisaged in that plant that permit the boxes of cores to be cleaned periodically, and this is necessary because agglomerant sand accumulates in them, which means that unless these are cleaned periodically and relatively frequently, the boxes of cores lose measurements, the air inlet filters may become blocked and the elements that eject the manufactured cores may become clogged. Thus, in a core production process for casting, at predetermined periods of time, the boxes must be taken out of the machine, cleaned and suitably fitted in the machine again. In the plant for automatic tool change mentioned above, no specific measures have been envisaged for these jobs. German Patent DE-3.706.879 has to be stood out, which relates to an installation for moulding manufacture, wherein it is described a production process, which object is the optimization of same by using a closed transport system, but that does not relates in detail which will be the elected option for said transportation which undoubtedly will depend of the volume and weight of the pieces to be manipulated. At present, another existing solution can be observed in PCT Patent application WO84/04061, wherein it can be observed a foundry plant and a manoeuvring apparatus used in said foundry plant. This apparatus which forms part of the general state of the art, deals with a cores manoeuvrer adapted to the transportation of same, and as such, it uses a gripper and transport system completely adapted for a specific kind of cores, neither it serving for other workings nor having the flexibility which has the transport element inside a plant. The above mentioned problems are solved by the features of claim 1. DESCRIPTION OF THE INVENTION The carriage for automatic change of tool, that is proposed in the invention, has been designed to satisfactorily overcome this problem, in the two above-mentioned aspects, and this carriage, in itself, is a far more simple solution from a structural point of view, with the consequent cheapening in costs which this represents, from the point of view of the carriage manufacture itself and its subsequent maintenance. In addition, this carriage incorporates means that allow for a periodic cleaning of the boxes of cores, thus resolving the second side to the problem. More specifically speaking, this carriage is basically formed of a rolling frame, where one of its shafts is a drive shaft, worked by a reduction motor; this carriage slides along rails laid out for this purpose on the floor between the core making machine and the corresponding tool warehouse. There is furthermore another set of reduction motors on this frame which are designed to activate the rollers which mobilize the tools in their movement to the machine and their subsequent extraction, and also during their movement to the warehouse and extraction from here. Obviously there are two reduction motors to activate the rollers because there are two work zones on the frame, since this is a double carriage, one for transporting the tool that is to be implanted in the machine, and the other to receive the tool which is in an operative state in the machine and which must be withdrawn before the new tool is implanted. On this basic structure of the carriage, which is self-sufficient for feeding and extracting tools as regards the machine for making cores for casting, there is an ancillary mechanism for periodic cleaning of the boxes of cores. This ancillary mechanism with the same basic confection, offers two specific performances depending on the kind of boxes of cores that are to be handled, because there are, as we know, boxes of cores that have vertical opening device and boxes of cores that have horizontal opening device. Specifically in the first case, namely boxes of cores that have vertical opening, there is a box frame in these boxes, inside which are the core ejectors, and on this frame there is a lower middle box, and on this, completing the unit, is an upper half box of cores. In this type of box, the ideal situation for cleaning it is an upright arrangement of the upper half box of cores, which furthermore should be shifted laterally in respect of the lower half box of cores; the ancillary mechanism is accordingly implemented on a support secured to the carriage frame, in correspondence with each end, namely with each of its operative sectors. A lever is joined articulately to this support, which is worked with the help of a hydraulic cylinder. At the free end of this lever, with the aid of guides and the assistance of another hydraulic cylinder, it receives a shifting plate, which contains clamps for the upper half box, so that this plate can adopt a horizontal position, can approach the entire box of cores through the drive of the corresponding hydraulic cylinder, maintaining this horizontal situation; it can secure the upper half box through the clamps that are associated with it, and then go up and finally tilt, as the arm does so in respect of the lower side support, through the other hydraulic cylinder; the upper half box consequently assumes an upright position and is displaced outwards in respect of the rest of the box of cores, which is the best position for cleaning. When the box of cores has a horizontal opening, in which case there is also a lower box frame with two side adjacent boxes which are designed to be separated from one another by moving horizontally in respect of each other, the mechanism is very similar to the above case, having the only exception that the structure described is double, that is to say, there are two plates, one for each half of the box of cores, which are now arranged parallelly and vertically in fixture phase, and which after being secured and with the clamps described in the above case, are moved and spaced, activated by corresponding hydraulic cylinders and at the end of this spacing phase they tilt, specifically when the levers to which these plates are joined on the corresponding lower supports do so, and by action of respective hydraulic cylinders which relate each support to its corresponding lever, and in this case a complete independence is obtained between the two halves of the so-called box of cores and the box-holder frame, which ensures an optimum positioning for the different elements of the box of cores, for their cleaning. DESCRIPTION OF THE DRAWINGS To complete the description which is being made and in order to help understand the, features of the invention better, a set of drawings is included in this application, and forms an integral part of it, and where the following has been shown by way of illustration but should in no way be considered restrictive: Figure 1.- Shows a diagrammatic side section of a double carriage for automatic tool change in bore making machines for casting, executed in accordance with the object of this invention, where the cleaning means for the boxes of cores have not yet been implanted. Figure 2.- Shows a side view of this same assembly as given in figure 1. Figure 3.- Shows a similar representation as Figure 1, but here the carriage furthermore embodies the ancillary mechanism which permits the cleaning of boxes of cores, specifically the execution corresponding to the case where the opening of these boxes of cores is performed in an upright direction. Figure 4.- Shows a side view of the assembly represented in the above figure. Figure 5.- Shows in a similar representation as that of figure 3, a carriage that holds an ancillary cleaning mechanism suitable for boxes of cores, whose opening is performed horizontally. Figure 6.- Shows, finally, a top view of the assembly represented in figure 5. PREFERENT EXECUTION OF THE INVENTION Based on these figures and more specifically figures 1 and 2, it can be observed how the carriage that we are now proposing is formed from a frame 1, which contains wheels 2, where those corresponding to one of its shafts are drive wheels and receive the movement of a reduction motor 3 secured to the actual frame 1, through transmission 4, where wheels 2 are designed to move the carriage on rails 5 which have been duly implanted on floor 6 and which communicate the coremaking machine or machines for casting with the corresponding tool warehouse. Inside frame 1 there are two groups of rollers 7-7', at the ends, which are designed to receive each of the tools, driven by respective reduction motors 8-8', whose outlet sprocket 9 transmits the movement to a sprocket 10 which is joined to a shaft 11 from which, at its ends and through sprockets 12, transmits the movement to sprockets 13 associated with the shaft of rollers 7 or 7'. Thus an extremely simple structure is obtained for the carriage, and it is capable of receiving two tools at the same time, at each of its end sectors, specifically at its sets of rollers 7 and 7', as we can observe in figures 3, 5 and 6. Using this basic structure for the carriage, which is maintained for any type of box of cores, this carriage is completed with an ancillary mechanism, for which two specific executions have been foreseen, depending on the type of boxes of cores which have to be handled; these executions are shown respectively in figures 3 and 4 and in figures 5 and 6. Specifically, in figures 3 and 4, as has already been mentioned, a complete carriage has been shown for use with boxes of cores whose opening is made vertically and where there is a lower box frame 14, a lower half box of cores 15 and an upper half box of cores 16. In this specific case, frame 1 is joined to a support 17 at each end corresponding to its two operative sectors, and to this support 17, through articulation 18, an arm 19 is attached, which tilts due to the effect of a hydraulic cylinder 20; arm 19 adopts an elbow shape, so that this arm can adopt the vertical position shown in figure 3 or a horizontal arrangement where it rests on top of the box of cores. At the end of arm 19 there is a set of slide guides 21 which are attached to a plate 22 which is actuated by a hydraulic cylinder 23; plate 22 embodies two sets of clamps 24 which are worked by hydraulic cylinders 25 and designed to grasp the upper half box of cores 16, as shown in figures 3 and 4. Based on this structure and an assembly of the different elements which make up the box on the set of rollers 7, the opposite to what is shown in figures 3 and 4, the ancillary mechanism and drive action of cylinder 20, is capable of adopting a horizontal arrangement for plate 22 where this plate faces the box of cores in the assembly allowing this rear plate later on to drop, by effect of cylinder 23, until it meets the upper half box of cores 16, when the actuation of cylinders 25 provokes closure of clamps 24 and the consequent locking of the upper half box of bores 16; the opposite drive action of cylinder 23 is then performed, to lift the half box 16, and also an opposite drive action of cylinder 20, so that arm 19 is tilted until it reaches the cleaning position, which is clearly visible in figure 3. In the specific case where the carriage is used for horizontal opening boxes of cores, boxes of cores where there is a box holder frame 26 and two boxes of cores or tool 27-27', as is specially observed in figure 5, the ancilliary mechanism basically maintains the structural features of the above case, although with slight modifications and with the exception that the structure for each box of cores is double, that is to say, there are two lower supports 17' joined to frame 1 of the carriage, in counter-position in respect of the box of cores 26-27-27', to which are joined articulately through points 18' respective levers 19', which are tilted by effect of these hydraulic cylinders 20', having the peculiarity that these levels now adopt an upright position, when arranged to hold the box of bores, compared with the horizontal position of the above case; each of these arms 19' have a plate 22' which is moved by effect of a hydraulic cylinder 23', also on guides; the plate has a number of opposing sets of clamps 24', which are worked by hydraulic cylinders 25'. In this case, the manoeuvre on the box of cores for cleaning these cores commences when plates 22' are brought near to the two boxes of cores 27-27', through the action of hydraulic cylinders 23'; when these plates make contact with these boxes 27-27', cylinders 25' are activated to effect the closure of clamps 24', and after boxes 27-27' are made secure, cylinders 23' work in the opposite direction, specifically spacing the plates, until the limit situation shown in figure 5; it is then that the lower hydraulic cylinders 20' are activated, making arms 19' tilt in the direction of the arrows shown in figure 5, in order to reach the final position for cleaning the boxes of cores 27-27', permitting a similar manoeuvre and, in the opposite direction, after cleaning, to carry out the new setting of elements 26-27-27' that form the box, so that this can continue performing its job as a tool.

Claims: Double carriage for automatic tool change in core making machines for casting, of the type that embodies a frame on which there are two sets of rollers capable of simultaneously or otherwise receiving respective tools or boxes of cores, duly motorized to establish access of the tools in the carriage and their subsequent expulsion, characterized in that it is made up of a supporting frame (1) with wheels (2) that run on rails (5) operatively implanted on the ground (6), in correspondence with the work line of the carriage; a reduction motor (3) is joined to the frame which transmits the movement to the shaft of two of the above-mentioned wheels, to mobilize the carriage; in addition this frame and in correspondence with the two ends or operative sectors of the carriage, embodies other reduction motors (8, 8') which transmit movement to sets of rollers (7, 7') that contain the tools; this transmission is carried out, for each of these sets of rollers, with the help of an intermediary shaft (11), which receives the movement from the reduction motor and transmits it in turn to the two side alignments of rollers (10, 12) of the corresponding set; on this carriage and in correspondence with each of its two ends or operative sectors an ancillary handling mechanism has been designed for the tools or boxes of cores, to open and place them in a suitable position for their periodic cleaning. Double carriage for automatic tool change in core making machines for casting, in accordance with claim 1, chararacterized in that the ancillary mechanism, and specifically the carriage application for boxes of cores for vertical opening, is implemented on a support (17) which is secured to the frame of the carriage (1) in correspondence with each end or operative sectors; there is an arm (19) which is joined articulately to the support (17), and which tilts by effect of a hydraulic cylinder (20); at the free end of this arm there is a set of guides (21) along which a plate (22) makes contact with this arm, and which is moved by a second hydraulic cylinder (23) at the end of which there are clamps (24) which are also activated by hydraulic cylinders (25) and designed to secure the upper half box of cores (16), all this so that the plate (22) can face the box of cores or tool assembly, in a horizontal position, can drop until it makes contact with the upper half box of cores (16), can grasp it with the above-mentioned clamps (24), can go up independently from the lower half box of cores and the corresponding box frame and lastly can tilt sideways until this upper half box of cores adopts an ideal position for cleaning. Double carriage for automatic tool change in core making machines for casting, in accordance with claim 1, characterized in that the ancillary mechanism, when the carriage is used for handling boxes of cores with horizontal opening, is implemented, for each of the two operative sectors of the carriage, on two supports (17') which are joined to the frame (1), encircling the group of rollers; a tipping arm (19') is joined to each of these supports (17') and is also activated by a hydraulic cylinder (20'); at the free end of this arm (19') and via guides, there is also a plate (22'), which is moved by a hydraulic cylinder (23') and has fastening clamps (24') for the two side portions of the box of cores or tool; these clamps (24') are also secured with the help of hydraulic cylinders (25'), so that from an upright position and maximum spacing for these plates, these can bring the two halves of the box of cores together until contact is made with them; it is then that these are secured by means of the clamps (24') which close; these plates (22') then withdraw again until they are spaced wide apart, dragging the corresponding portions of the boxes of cores (27, 27'), so as to then tilt the arms (19') downwards and outwards, also dragging along with them the two portions of the box, until an ideal position is reached to clean them.

Inventors: ARANA ERANA AGUSTIN, ARANA ERANA, AGUSTIN
Applicants: ERANA AGUSTIN ARANA, ARANA ERANA, AGUSTIN
Application year: 1988
Main classification: B22C9
IPC codes: B22C19