DE3118102A1 - UNPACKING DEVICE FOR MOLDING MACHINES IN FOUNDRY SYSTEMS - Google Patents

Description

Patern to walte Dipl.-Ing. Curt Wallach

η, Dipl.-Ing. Günther Koch

Dipl.-Phys. Dr Tino Haibach

Dipl.-Ing. Rainer Feldkamp

D -8000 Munich 2 Kaufingerstraße 8 Telephone (0 89) 24 02 75 Telex 5 29 513 wakai d

Date: 7th time I98I

Our reference: 17 192 - Κ / Αρ

Applicant: Neechi Societä per Azioni

Via RIsmondo, 78
27IOO Pavia
Italy

Title: Unpacking device for molding machines in

Foundry plants

The invention relates to an unpacking device in foundries and casting machines, in particular at such foundries can be used in which the molding boxes automatically after the casting station and then to be transferred to the following workstations. In the forming station, the model carrier plate moves from below up the molding box, which, as soon as it has reached a certain height, is locked and filled with sand which is then tamped down by the usual devices will.

After the molding process is completed in this way, will the model carrier plate is lowered together with the molding box and stopped when the height of the transport level is reached is. The model plate continues to lower, causing the actual unpacking operation to begin, at its end the molding box makes its way from the molding station and he will then replaced by a new molding box.

The operations described so far are characteristic of the already known systems. Constant use However, the molding boxes cause deformation, especially as a result of the high temperatures they encounter during the casting process are exposed. So it happens often enough that after a certain time, as a result of the deformations, the lower The surface of the molding box is no longer exactly in the storage plane that is used by the unpacking rollers or the bumpers Transport level is formed after the forming station.

As a result of these uncertain storage conditions, the molding box pushed away at the beginning of the unpacking process that he had a assumes different storage position on the rollers. This relative displacement between the molding box and the model results

certain stresses on the solidified sand, and in certain cases this causes at least the formation of cracks the less elastic parts and those parts whose unpacking causes certain problems anyway. To these difficulties to avoid was the bearing surface of the molding boxes periodically subjected to a sole grinding process so that the ground was level again. This grinding process required not inconsiderable cost, and after a long time the height of the molding boxes became unacceptable reduced so that they had to be replaced as a whole.

In view of the high costs for the molding boxes and in view of the production losses in the case of defective molding boxes it has proven necessary to study different solutions to the problem. Task of the present The invention is to find a particularly favorable solution in this regard. The technical problem to be solved was there therein, a new uniform bearing surface for the flasks to create, i.e. a plane that is able to adapt itself if this is necessary in order to to compensate for possible deformations to which the storage level of the molding boxes was subjected.

The solution to this technical problem is characterized by that four hydraulic cylinders with pistons are introduced which are operated so that they are self-aligning Form bearing elements so that the molding boxes adapt themselves during the unpacking process. Also is the piston associated with a locking system in order to stop the movement of the molding boxes in connection with the Model carrier table, which while it continues its downward movement, carries out the unpacking process correctly.

An exemplary embodiment of the invention is described below with reference to the drawing. In the drawing show:

Fig. 1 is a schematic exploded perspective view of the invention Contraption;

Fig. 2 is a plan view of the device of Fig. 1;

Fig. 3 shows a detail of the device according to Fig. 1;

FIG. 4 shows a section along the line 4-4 in FIG. 3i

5 shows a pneumatic circuit diagram of the device.

In Fig. 1, the reference numeral 10 denotes a molding box, which consists of four vertical walls 12 and two frames, namely an upper frame 14 and a lower frame I5, which limit the side walls. Characterized in that the molding box in vertical planes parallel to the transverse axis or the The longitudinal axis of the molding box is divided, the contours of the walls are given the shape of a "C".

This configuration depends on the transmission system of the From molding boxes that are transported on roller guides 16.

The molding box rests on its way to the Foritfstation the rollers with the lower surface of the upper frame 14, and he is on these guide rollers by special arms moved, which are pneumatically operated. In addition to the forming station, the roll walls are designed so that the rolls

are aligned on a bottom line in such a way that the flask is on them with the bottom surface of the lower frame 15 (Fig. 2) rests so that the vertical shifts can be carried out during the Forming process and during unpacking are required, as will be explained below.

The model carrier table 18 is located in the forming station, which is provided with two vertical pins 20 which fit into corresponding holes 22 made on the frame 14 and 15 of the molding box 10 are provided.

The model support table 18 is rigidly connected to the piston rod 24 of a piston 26, which is in a single-acting pneumatic cylinder 28 (Fig. 5) runs, and so the table follows the movements of the piston rod and is held by the body 29 led. With the inner walls of the plates 30 (Fig. 2) are four small cylinders 32 with correspondingly small pistons 34 is provided, the function of which is described in detail below with reference to FIGS. 1 and 5.

Via a rod 36, a cam 38 is connected to the model support table 18, which actuates some valves that the successive phases of the molding process and the unpacking process controls, as described in connection with the pneumatic circuit diagram according to FIG. Hereinafter Referring to FIGS. 3 and 4, one of the four cylinders 32 will be described in detail.

In the upper part of the cylinder there is a piston 34 which is operated hydraulically. The hydraulic oil that is used in the tanks 102 and 1C8 (Fig. 5), flows into the cylinder from below through a hole 42 (Fig. 3) and

passes through a circular chamber 44 and lines 46 as well via a bore 48 and a hole 50 (Fig. 4) in the cylinder, in the lower part of the cylinder is a locking device attached to the oil flow and ultimately the movement of the piston 34 prevented in a given direction.

This closure device consists of a small piston 52 which is displaceable within a sleeve 54 and as conical valve body is formed on one side, which fits into an opening 56 which the channel 46 with the Hole 48 connects. The opposite side of the small piston 52 is connected to the air inlet 60, which in turn is in communication with a pneumatic device which operates the entire unpacking device.

A line is also located in the cylinder 32 (FIG. 3) 62 to introduce the oil into the top of the cylinder through a hole 64 to move the piston down.

The mode of operation of the device is described below in conjunction with FIG. 5, in which, for the sake of clarity, only those elements are shown which are directly related to the mode of operation of the device. To understand the operation, it is sufficient to realize that the lines I53 and I53 ^{1 represent} the air supply lines, while the lines 149 and I5I are connected to the rest of the pneumatic circuit. The line 151 is under pressure in the lifting phase of the model support table 18 and when it is lowered it is depressurized. The line 149 is depressurized in the lifting phase and is under pressure in the lowering phase. When the molding box 10 has reached the molding station, it delivers a pneumatic signal of the connection to the preprocessing valve I50 via the line I5I. This valve

150 connects the general air supply I53 to one Auxiliary valve 154, which, like valve I50, switches itself. The valve 154 allows air to the cylinder 25 arrive, which moves the piston 26 and the model support table 18 and the molding box 10 carried thereby upwards.

When the table 18 in its upward movement reaches a height at which its cam 38 the valve 166 switches, a pneumatic switchover signal is supplied to valve 100, which is connected to main supply line I53 ' communicates. As a result, the compressed air reaches the tank 102 and forces the oil into the line at 102 104 and into the cylinder 32 to the unpacking piston 34 upwards to move.

After the upper end position on the path of movement has been reached, the model carrier table 18 is actuated by the cam 38 the valve I68. This switches itself over and sends the air from the line I5I to the auxiliary valve I70 and switches this around.

The air reaches a double acting cylinder I73, whereby the piston 175 is shifted to the left and a mechanical block 177 of the piston rod 24 of the piston 26 is operated. In this way, the molding box 10 is in its sand loading and in its tamping position for the molding process kept.

At the end of this operation, the lowering phase begins: The valve 168 is vented via I5I, which enters the venting phase enters, and the valve I70 is switched over via line 149, which is activated by air after the cylinder

to send, causing the piston 175 to move to the right again and the piston 26 releases. At the end of the movement, the piston 175 toggles the valve 144, and consequently If the air from line 149 reaches the auxiliary inlet of valve I50, which switches itself over and the valve I54 transferred to the venting position. Since the piston 26 is no longer fed, this begins together with to move the molding box 10 and the model support table 18 downward under the action of gravity. At the beginning of Lowering movement switches the model carrier table with the cam 38, the valve 166, which is switched and the air can be reversed by tank 102. The molding box 10 is now at the bottom in its lowered position on the unpacking piston 34, which are automatically aligned and a safe Form support for the molding box.

At the end of the movement of approximately 100 mm, the cam 38 actuates the valve I80, which supplies a pneumatic signal to the switchover valve 182. The air reaches the connection 60 (FIG. 4) via the supply line I06, so that the oil shutdown device 5I is actuated. The piston 52 (Fig. 4) is pressed against the surface 56 and closes the oil channel. In this way, the molding box is locked and held in place by four oil cushions, each of which comes to lie between the locking piston 52 and the piston 34 (FIG. 4).

The model support table 18 continues to move downward, making the unpacking process more convenient It is carried out in a manner that does not run the risk of cracking the weaker parts of the mold.

When the lowest position is reached, the auxiliary lever falls

from the flakes 3 °

of the valve I8o / ab, so that the valve 182 is again in the

- li -

ventilation phase is switched, which in turn the oil barrier device 5I is transferred to the ineffective position.

In this position, the valve 164 is switched, which in turn is in communication with the valve 110 , which allows air to pass from the line I53 to the tank I08. Thus, the oil actuates the piston 34 in the cylinder J2 and causes a downward movement, so that the molding box 10 can rest on the carrier rollers at the end of its downward movement and can leave the mold station.

Claims (3)

Claims 1. Unpacking device for molding machines in foundries that have a transport system, with which the molding boxes are transferred by rolling, with a model support table in the molding and unpacking station, which comes to lie under the molding box and this is vertical raises and lowers, characterized in that it is equipped with a carrier surface, which is formed by self-aligning elements to the usual storage level of the molding box, which is formed by the conveyor rollers to replace during the unpacking process. 2. Unpacking device according to claim 1, characterized in that the elements that form the storage level are made from There are four hydraulic cylinders, the pistons of which are actuated so that self-aligning bearing elements be created relative to the molding box while the lowering phase is carried out, and that Locking means for the piston are provided to prevent the molding box movement relative to the model support table stop and stop the downstroke when the unpacking process is performed. 3. Unpacking device according to claims 1 and 2, characterized in that that the blocking of the piston in a predetermined position is accomplished by a piston which 3113102 slidable within a sleeve made in one piece with each piston, and that the piston is designed at one end so that it works as a valve body, which blocks the flow of the oil feeding the cylinders.