DE2933869A1 - METHOD AND DEVICE FOR CASTING A SUB-BOX MOLD - Google Patents

Description

-S-

32 474

Sintokogio Ltd., Nagoya / Japan

Method and apparatus for casting a

sub-box shape

The invention relates to a method for producing a shape, in particular a lower box shape, wherein the Ünterkastenform is produced in that pressurized air is filled into the space through the molding sand, which is formed by the upper box and the core in order to compact and solidify the molding sand, in particular the sand in the immediate vicinity of the core, after which the molding sand is compressed as a whole.

The present invention also relates to an apparatus to carry out the procedure.

In the production of an upper and lower mold by the aforementioned method, problems then arise when a Mold plate core is used. That is, when the molding sand moves towards the core under high pressure, in itself or between the and the molding box deep

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If there are recesses, the molding sand is not sufficiently brought to the surface of the core, while at Moving the sand with low pressure, the part of the molding sand which is in the vicinity of the core is not enough is highly compressed, so that the shape produced does not have sufficient hardness.

Therefore, it is impossible to make a complicated lower mold at the same time as an upper mold according to the aforementioned method to manufacture.

The object of the invention is to avoid the aforementioned disadvantages.

To solve this problem, a method is proposed which is characterized in that molding sand in a Space between an upper box and a pressure plate is filled, which is slidably arranged in the upper box is and is provided with a device for blowing compressed air in the upward direction that on the top of the upper box containing the molding sand, a core with a plurality of air outlet holes is arranged that of the blowing device formed in the pressure plate is first supplied with compressed air so that the molding sand moves in the direction Moved on the core that from the blower then in a further process step compressed air with a Flow rate or a pressure is supplied which is greater than that of the supplied compressed air, so that the Density of the molding sand in the vicinity of the core increases and that the pressure plate is moved upwards to the molding sand squeeze all together.

Further details, features and advantages of the invention emerge from the following description of the FIGS accompanying drawings purely schematically illustrated embodiments. Show it:

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Figures 1 to 3 are sectional views of the mold making steps of a method according to the invention.

In the drawings, the reference numeral 1 denotes a lower box tilting frame, which by cylinder 2 in vertical Direction can be moved. In the lower opening of the lower box tilting frame 1 is a pressure or squeeze plate 5 is provided, which is attached to a piston rod 4 which can be moved upward. An airtight seal 5a is inserted along the peripheral wall of the pressure plate 5 so that the latter is airtight into the lower box tilting frame 1 is used. The pressure plate 5 has upper and lower walls that form a chamber 6. Located in the top wall air flow openings 7 through which the chamber 6 communicates with the outside. The lower wall of the Pressure plate 5 is provided with a bore 8 through which compressed air can be introduced. To the hole 8 is a flexible compressed air line 9 is connected, the other end of which is connected to a compressed air source (not shown) is in communication via a main line system 12 including a shutoff valve 10 and a flow regulating valve 11.

The main line system 12 has a first by-pass line system 13 connected, which is connected upstream of the flow regulating valve 11 to bypass the valves 11 and 10 branches off from the main line system 12 and then downstream of the shut-off valve 10 converges again with the main line system. The first by-pass line system 13 is with a first by-pass shut-off valve 10a and upstream of the first by-pass shut-off valve 10a with a first by-pass flow regulating valve 11a. The first By-pass line system 13 is in turn connected to a by-pass line system 14, which is upstream of the Flow regulating valve 11a to bypass the valves

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11a and 10a branches off from the first by-pass line system and downstream of the first by-pass shut-off valve 10a converges again with the first by-pass line system 13. The second by-pass line system 14 is with a second by-pass shut-off valve 10b and with a second By-pass flow regulating valve 11b is provided, which upstream of the second by-pass shut-off valve 10b.

Above the lower box tilting frame 1 hollow roller conveyors 15 are arranged, which are at a distance from each other, so that the Lower box tilting frame 1 can be moved up between these. On the hollow roller conveyor 15 is an upper box 16 can be placed, which can be moved in the direction of or away from the surface of the lower box.

On the upper case 16, a mold plate core 17 is arranged, which in the direction of and from the upper case 16 on the the side opposite the sub-box 1 is moved (the opposite side is shown in the illustration in the top of the drawings). The core 17 is provided with a recess 19 which is formed in the core itself is. The core 17 is also provided with recesses 18, which lie between the core 17 and the upper box 16. These Openings are difficult to fill with molding sand. The core 17 consists of an upper and lower core section, between which a chamber 20 is formed, which is in communication with the outside. The core 17 is still provided in the lower core section with narrow channels 21 which are in communication with the chamber 20. The channels 21 are arranged in a greater number in the bottom surfaces of the recesses 18, 19 than in the other areas the same. In the channels 21, not shown, ventilation ports are used.

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The flow regulating valve 11 is set so that Compressed air is supplied in such an amount that is sufficient to pass the molding sand 23 through the pressure plate 5 to convey incoming compressed air at low speed upwards. The regulating valve 11a is set so that that compressed air is supplied in such a large amount that is sufficient to generate a high pressure in the molding sand 23 as a result of the pressure loss in the molding sand 23 and the channels 21. The flow regulating valve 11b is set so that that compressed air is supplied in an amount sufficient to prevent the raised molding sand 23 falls down.

In the accompanying drawings are another top and bottom box and another pressure plate for simplicity for the sake of omission, which are normally arranged above the top of the core 17.

In a device of the type described above, the upper box 16 is moved onto the lower box 1, in which the pressure plate 5 is located. Cylinders 2, 2, 3 are then actuated to lower the lower box 1 and the pressure plate 5 to move upwards and lift the upper box 16 from the roller conveyors 15 by a small amount and then to stop. A predetermined amount of molding sand 23 is then from a funnel (not shown) into a Filled space, which is formed by the lower box 1, the pressure plate 5 and the upper box 16. Thereupon a core 17 is placed on top of the upper box 16. The cylinders 2, 2, 3 are then actuated to the To press the upper box 16 against the underside of the core 17, as shown in FIG.

The valve 10 is opened for a predetermined period of time so that compressed air from the compressed air source via the line 9,

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the bore 8, the chamber 6 and the air flow openings 7 can flow to molding sand 23. The flow of compressed air introduced by the aforementioned process is used to move upwards of the molding sand 23 at a low speed. The molding sand flows into a recess 18 with many narrow channels in the bottom surface, so that the recesses 18 and 19 are filled with the molding sand 23. The compressed air reaches the outside via the channels 21 and the chamber 20.

Accordingly, the molding sand 23 abuts violently against projections of the core 17, and is pressed into the recesses 18, 19, but without being solidified so that the density of the molding sand 23 in the recesses 18, 19 in is increased sufficiently.

When the valve 10 is then closed and the valve 10a is opened for a predetermined period of time, compressed air flows in the same way previously mentioned. The compressed air flows in such a large capacity that under the molding sand 23 a high pressure is generated. This increases the density of the molding sand, which is close to the surface of the core 17 is significantly increased, which solidifies the sand. (Fig. 2). When the valve 10a is closed and the second By-pass shut-off valve 10b is open, the piston rod is 4 of the cylinder 3 extended and thereby the pressure plate 5 moved upwards so that the molding sand 23 as a whole is compressed (Fig. 3). The falling of the molding sand 23 is prevented by opening the second by-pass shut-off valve 10b prevented. This state continues until the compressing operation of the pressure plate 5 is started. If the molding sand cannot fall down, the second by-pass line system 14 with the second by-pass shut-off valve 10b and the second by-pass flow regulating valve 11b can be omitted.

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The purpose of the compression process corresponds to that described above Way is to solidify and compact the molding sand, which is insufficient and is less compacted than the molding sand, which is pressed onto the surface of the core 17 by means of the compressed air became. This compression process has a little effect on the molding sand, which is already highly compressed by the compressed air became.

When the cylinders 2, 2, 3 are moved back to lower the lower box and the pressure plate 5, the upper box becomes 16 moves away from core 17 and returns to roller conveyors 15. At that time, a lower box molding was made in the Upper box 16 shaped.

The release of the lower box shape from the upper box can easily be done in that compressed air through the channels 21 on the Molding sand 23 is directed. Another line system 14a with a three-way valve 10c is used for this purpose, wherein the three-way valve 10c is arranged between the channels 21 and the second by-pass system 14. Of the Lower box tilting frame Ί and the pressure plate 5 are removed from the upper box 16 when they are reduced by a small amount moved down.

The lower box shape is with the upper box, which has been returned to the roller conveyors 15, in one Molding assembly position transferred without the top facing down. The lower box shape is then with united in an upper box shape, which at the same time on the other half of the core, i.e. on the other side of the Kerns 17 was made so as to create a complete shape.

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After an upper box containing a lower box shape is carried away an empty upper case is inserted into the device and the above-described process is repeated.

In the aforementioned embodiment, the upper box is on top of the lower box tilting frame 1 to and from this moved away to make a sub-box shape. However, the lower box tilting frame 1 can be eliminated so that the pressure plate 5 is placed directly on the upper box 16. In this case the completed The mold is removed from the upper mold box 16.

In the embodiment described, the flow rate is the compressed air supplied through the pressure plate 5 is regulated. The same effect can also be achieved by that the pressure of the compressed air is regulated.

Although the shutoff valve 10 is closed when the first by-pass shutoff valve 10a is opened, it may be at the same time the shut-off valve 10 remain open.

Thus, the method described above consists in principle in that compressed air is generated in such an amount that which is sufficient to move the molding sand upwards from the pressure plate at low speed so as to remove the molding sand to press into the deep recesses of the core. A large amount of compressed air then flows to the molding sand around it to compress to a high density, especially in the area which is in the immediate vicinity of the Kerns lies. Then the molding sand is compressed as a whole by placing the pressure plate on the molding sand is moved. Despite the deep recesses in the core and between the core and the upper box, the molding sand can completely fill the recesses while ensuring high compression of the molding sand. That

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The method according to the invention is highly effective in particular when it is used to produce a lower box shape in connection with a mold plate core (match plate type pattern). In addition, a produced lower box shape can be combined with the other molded part without the top side having to be tilted downwards. This serves
preventing the mold from being damaged during handling.

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Claims (12)

32 474 Sintokogio Ltd., Nagoya / Japan Method and apparatus for casting a Lower box shape Method of casting a sub-box shape, thereby characterized in that molding sand is in a space between an upper box and a pressure plate is filled, which is arranged displaceably in the upper box and with a device for blowing is provided by compressed air in an upward direction that on top of the upper box containing the molding sand a core with a large number of air outlet holes is arranged that compressed air is first supplied from the blowing device formed in the pressure plate is that the molding sand moves in the direction of the core, that of the blower then in a further process step Compressed air is supplied with a flow rate or a pressure which is greater than that of the supplied Compressed air so that the density of the molding sand in the vicinity of the core increases and that the pressure plate after 030046/0582 ORIGINAL INSPECTED - ο - is moved above to compress the molding sand as a whole. 2. The method according to claim 1, characterized that the molding sand is in a space which is formed by the upper box, that a lower box is arranged below the upper box and that the pressure plate is used in the lower box is. 3. The method according to claim 1 or 2, characterized that in a third process step compressed air in an amount or with a pressure is supplied, which is less than the flow rate or the air pressure of the supplied in the second phase Compressed air. 4. The method according to claim 2, characterized in that the upper box, the lower box and the pressure plate are assembled such that the pressure plate is inserted into the sub-box that the upper box is placed on top of the lower box and that the lower box is moved upwards to to hold the upper case on it. 5. The method according to claim 4, characterized that the molding sand is used in the lower box before the upper box on the lower box is put on. 6. The method according to claim 1 , characterized in that compressed air is blown downwardly via air outlet bores located in the core in order to remove the core from the completed lower box shape. Ü30046 / 0582 7. Device for producing a ünterkastenform and for Implementation of the method according to at least one of Claims 1 to 6, characterized by a vertically movable upper box (1), a sliding plate (5) inserted in the molding box (1), a core (17) which is provided with a plurality of air outlet bores (21) and which can be placed on the upper box (16) is, by means of means for supporting the core (17) over the upper box, means for moving upwards of the upper box for placing the same on the core (17), a device located in the pressure plate (5) (7, 8, 9) for blowing in compressed air and a device for optionally supplying different compressed air Flow rate or different pressure to the blower. 8. Apparatus according to claim 7, characterized that the pressure plate (5) inside - Has a chamber (6) that the blowing device in the top of the pressure plate (5) is provided and consists of a plurality of air outlet bores (7), which are in communication with the chamber (6). 9. Device according to claims 7 and / or 8, characterized in that a A plurality of line systems (12, 13, 14) a compressed air source connects with the blower that each line system has a shut-off valve (10, 10a> 10b) and a flow or pressure regulating valve (11, 1ta, Hb). 10. The device according to at least one of claims 7 to 91, characterized in that the pressure plate (5) is provided with an airtight seal (5a) which runs along the peripheral wall of the pressure plate and rests against the inner wall of the upper box. ο r, π, 11. The device according to at least one of claims 7 to 1o, characterized in that a device (14a, 1oc) is provided to optionally to connect the air conveying device to a device by means of the compressed air through the core located outlet openings to the bottom of the upper case (16) can be guided, the easier it is to remove the finished lower box shape after its completion. 12. Device for producing a lower box shape and for performing the method according to the claims 1 to 6, characterized by a vertically movable lower box (1), one slidable therein inserted pressure plate (5), a device with which an upper box (16) in a position above the lower box (1) can be brought, a core (17) with a plurality of air outlet bores (21), which in the upper box (16) can be used, a device for transferring the core (17) over the brought into position Upper box (16), a device for moving upwards of the lower box (1) together with the pressure plate (5) so as to place the upper box on the lower box and the core (17) to be aligned on the upper box (16), a blowing device provided on the pressure plate (5), can be blown with the compressed air towards the core and through a device for the optional introduction of Compressed air of different amounts or different pressure in the molding box. 03CC4S / 0532