DE1238829B - Device for pressing hollow blocks in a mold by means of cores that are expandable in cross section - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

B28c

German KL: 80 a - 43/15

Number: 1238 829

File number: W 28493 V / 80 a

Filing date: September 1, 1960

Opened on: April 13, 1967

The invention relates to a device for pressing hollow blocks in a form by means of Elastic cores that are stretchable in cross-section, in which the bottom and / or cover of the mold is placed in a mold frame can be pushed in and one end of the core is attached to the bottom or cover of the mold or with its holder protrudes through this and can be pulled out of the molding with its fastening is.

In the known pressing devices of this type, the core has an elastically stretchable jacket, which is inflated by a pressure medium. This design of the core has various disadvantages. Through hard and sharp-edged foreign inclusions in the ceramic raw material to be pressed in the mold damage to the surface of the elastic core sheath can easily occur, which is then caused by the constant stretching of the core sheath will continue to tear over time. Tearing on is favored by an overstretching of the injured areas, which occurs when due to coarser or larger grains of clay or Carelessness the filling of the molding box is less at this point. It is also used for generating the compressed air with a pressure of 15 to 20 atmospheres and for the permanent maintenance of this pressure requires a relatively large amount of energy, taking into account that for economical production at least a few thousand moldings have to be produced in the device per day and thus the pressing process must take place as quickly as possible. This requires a considerable amount of air, if the molding to be pressed has a volume of more than 6 to 8 or even of has more than 201, as is the case with large format bricks. The one for controlling the pressure medium The necessary valves are prone to failure in the rough operation of a brick factory. By the limited Cross-sections of the control valves also require considerable time for the injection and discharge of the compressed air required, whereby the number of shapes to be pressed with the device in the unit of time is limited is. Also, such a pressing device is not for the supply line of the pressing agent Arrangement on a turntable suitable, but this is useful for the production of large numbers of molded parts in the time unit is desired.

To avoid these disadvantages of pressing devices with inflatable cores, according to the invention, in the device of the type described above, the or each elastic core is so massive that it is compressible, and a mechanical device actuated by the press is provided, with a device for pressing Hollow blocks
in a form by means of being stretchable in cross section
Cores

Applicant:

Dipl.-Ing. Eugen Wiest,

Friedrich Nawrath, Untereichen on Jllertissen

Named as inventor:

Dipl.-Ing. Eugen Wiest,

Friedrich Nawrath, Untereichen on Jllertissen

which the core is to be compressed directly in the longitudinal direction to enlarge its cross-section.

Compressible elastic means in compression molding are known per se, but only in the case of a device for molding insulating bodies for spark plugs and similar small ceramic bodies from fine ceramic powder. There mold blocks made of soft rubber are enclosed in the mold frame, each of which contains a cavity for receiving the ceramic powder. When the bottom and top of the mold are pressed into the mold frame with a pressure of about 70 kg / cm ² and higher, the rubber assumes flow properties and, like a liquid, exerts the same pressure on the ceramic material in the cavity from all sides and compacts it so to a molding.

In the manufacture of flat clay slabs, it is known thereby recesses in one of the plate surfaces for the plates to adhere to one Produce mortar layer that in the form of a rubber sheet with short compressible massive Projections are inserted, which form the depressions in the surface, and, since they are made of rubber allow easy pulling out of the indentations, even if, as intended there, in the edge area, viewed from the center of the panel, are directed obliquely outwards. With the manufacture This process has nothing to do with hollow blocks.

Finally there is a device for the production of undercut, for anchoring a bitumen layer or the like. Serving recesses in the top of paving blocks are known. These dovetail recesses are

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in each case by moving one of two against each other - but should always expose the same external dimensions Parts made of existing stamps. They sit. In addition, there is the ceramic raw material The end face of the punch is a predetermined pressing pressure on a rigid component for each molding provided that is to be exposed to the hollow core interior, the different filling must conically tapered and over compression springs on 5 of the molding box by different volumes a stamp plate is supported, on which a hollow to be generated by the cores hollow spaces out of cylindrical Rubber stamp is attached, which will be matched when. With the known, by a Pressing in the stamp with its lower edge pressure medium inflatable cores can be used the conical surface of the rigid body is filled with different fillings by the more or less acts and expands as soon as the rigid io large inflation of the kernels are compensated for. Stamp part by the counterpressure of the material in order to compensate for this in accordance with the the form comes to a standstill. The hollow rubber invention provided compressible core to stamp Thus, when press-fitting to form the rich, the core, which is advantageously dovetail-shaped at its end Wells widened, sometimes from a cup-shaped core shoe as it is known from inflatable cores. 15 is held, with its core shoe in a holding

A compressible core according to the invention tion of the core-forming sleeve is slidably arranged would of course make no sense if you put him and the core shoe directly or indirectly on in a mold box of constant volume with a pre-tensioned spring provided in the sleeve would build, since yes the volume of the elastic would be supported. The spring receives such a front core is not changed during the upsetting process, but tension that with little filling of the molding box because in this process only the core is sufficiently compressed in its core Shape is reshaped. When the device is used. Is the molding box filled normally or stronger Manufacture of hollow blocks, in which the compression-filled as normal, so leaves that between the individual capable core is used, however, the mold cores or these and the mold frame are together and / or cover, ζ. B. by means of a press, 25 quantity pressed raw material a further cross-section in the mold frame can be pressed in. enlargement not too. The pressing pressure then causes

Due to the press stroke, however, a compression is a sliding back of the core shoe against the front Molding compound mainly only in the area of the tensioned spring.

of the mold bottom moved by the press and / or If the core is only at one end on the mold -deckels, so at the ends of the cores, achieved where 30 lid or bottom or one through an opening a compressible bracket is attached, which is able to withstand the cross-section and protrudes through it, Larger core can have no or only limited effect in the opposite end of the core. As is well known, it is with the help of simple mold covers or bases overlying the stamps press due to the strong friction of the molding compound provided during the actual press stroke on the side walls it is not possible to close one at the same time through the core end so far, moderate compression of a loose molding compound over that practically no ceramic material, but air to reach the entire height of the molding. can emerge. With a device according to the invention However, the fact that the mold bottom and cover converge, in which the upsetting force of one in the mold is approaching, becomes at the same time a volume reduction frame that can be pressed into the mold cover or base Modification of the molding box contents obtained, so that it is applied through 40 to the free end of the core, can when the core is compressed, cross-sections on this mold cover or base with the Sectional enlargement of the projections cooperating in the central area of the free core end Mold box located raw material, which should not be provided now.

can evade, is compressed, although the core should be more advantageous at its free end.

Volume of the nuclei not increased. 45 be dome-shaped in order to achieve a gradual

A solid core is practically insensitive to the transition of the cross-sections in the hollow building block

against injuries. The plant to produce an effect. To with such a shape of the core

Pressure medium with the associated lines and a uniform transmission of the upsetting pressure

Valves are no longer needed. The pressing process is done directly without getting the whole core cross-section, the core is

Interposition of an auxiliary medium causes. 50 expediently at its free end with a

The device is particularly simple if a curved cap made of metal or the like is provided,

the upsetting of the core is caused by the fact that, in the case of cores, in relation to the diameter

Having one end of the core long for upsetting by one exists in upsetting

Mold cover that can be pressed into the mold frame, the risk of the core buckling to the side,

is to be charged. The pressure of the press is 55. To prevent this, the core can be equipped with a

then provided on the mold cover at the same time both on the longitudinal bore and with this on one

the raw material as well as the core or the rod-shaped core support. For

Cores exercised, these to the extent of their reduction in friction between the core support and

Compression in the cross-section increase and thereby the core becomes the core support advantageously

the upset pressure exerted on him or her partially hollow and executed with radial openings and the

point as the compression pressure on the cavity of the core support created in the middle

The area of the molding box is filled with a lubricating liquid that reduces the friction between

wear. see the elastic core and its support

Different fillings of the molding box are reduced.

not to be avoided, as the raw material as granular 6 ₅ To ensure a good seal of the liquid-filled

Well poured into the molding box and reach the cavity to the outside and a good one

Grains of different sizes up to 10 mm through connection between the domed cap or the

can have knives. The finished molded part holder with the elastic cylindrical body

To achieve the core, this can each have an annular recess on its end faces, in which protrudes an annular collar on the cap or in the core shoe.

The core support can be firmly connected at the upper end to the domed cap located at the free end and be slidably guided at the lower end in the core shoe and / or in the holder.

In order to reduce the compression pressure required for changing the shape of the core, the core at least in the middle of its longitudinal extension with a closed, preferably cylindrical and be formed of a liquid-filled cavity. If fluid is spoken of here, it should thus also other fluids that can transmit a pressure, possibly also under pressure standing gas.

The required deformation work depends on the volume of the material to be formed. In the case of the core formed with a cavity, the volume of the material is elastic is deformable, less, so that the work of deformation is less because the liquid has no work of deformation records. However, the cross-sectional enlargement is for a certain degree of compression the same, since the liquid as well as the rubber or the like, of which the elastic core is made, is incompressible is. The remaining cross-section of the core must still remain so strong that this quickly returns to its original shape when the upset pressure is removed and the core is withdrawn from the molded molding.

To support the expansion of the central area of the core during compression, the with Liquid-filled cavity of the core or the core support can be connected to a pressure source and the means be such that the introduction of a predetermined amount of pressure fluid in this cavity depending on the application of the longitudinal pressure for upsetting the Kerns takes place. This can be done in that a pump is used as the pressure source, which of the Press the device is to be operated during the press stroke.

It can also be provided with such a pump every single press core by using the hollow Core support a piston is attached, which slides in a cylinder filled with the liquid, which is arranged within the core holder. The cylinder can be connected to the core shoe and slide with this in the holder. Because the hollow core support is in the core holder during the upsetting process slides, is thus simultaneously with the application of the upsetting pressure on the core in the core itself an internal pressure is generated.

In order to compensate for an uneven filling of the molding box, the with liquid filled cavities at least some of the cores are interconnected. Compensating a uneven molding box filling can also be obtained or improved in that the with the liquid-filled cavities of the cores are connected to a pressure equalization chamber, the is limited by a piston or a membrane, which is on a pretensioned compressed air cushion or a preloaded spring is supported. This pressure equalization space can also be used in each case by the one in the Bracket provided cylinder itself be formed, for. B. by the attached to the core support Piston in the cylinder opposite an opposed piston is arranged, which is on a preloaded Spring supports. If, during further upsetting, the cross-section of the core is due to a larger filling of the molding box can no longer be enlarged further, liquid is transferred from the cavity into the Pressure equalization chamber pressed and with it the piston

ίο against the pre-tensioned air cushion or the pre-tensioned one Spring shifted.

The invention is illustrated more schematically below with reference to the hand Drawings of exemplary embodiments explained in more detail.

F i g. 1 shows, in longitudinal section, a first embodiment of a device for pressing hollow blocks with the features of the invention, namely on the right side of the figure is the device Shown in front of and on the left during the pressing process;

F i g. 2 shows the detail II from FIG. 1 on an enlarged scale;

Fi g. 3, 4 and 5 show in section part of a further embodiment of a device according to the invention during different stages of pressing;

F i g. 6 shows the detail VI from FIG. 3 on an enlarged scale;
7, 8 and 9 show part of a third embodiment of a device according to the invention during different stages of pressing, and

F i g. 10 shows the detail X from FIG. 7 on an enlarged scale.

The device, designated as a whole by 1, according to FIG. 1 has one consisting of four side walls Mold frame 2, one attached to the upper end of a ram 3 mold bottom 4 and one Mold cover 6 attached to an upper ram 5. Mold bottom and cover fit exactly into the mold frame and can be pressed into it. The side walls can be around Hinge pins 7 extending parallel to the mold bottom 4 are pivoted outward, as on the right side of Fig. 1 is shown in dashed lines.

In the mold frame there is a number of cores 8 made of solid rubber, which are from the The mold bottom 4, in which they are held in a cylindrical recess 9, extend towards the mold cover 6. As shown in Fig. 2, the mold bottom 4 adjacent end of the cores 8 of one Enclosed core shoe 10, which is slidably guided in the recess 9 and is located therein on an abutment 11 supports. The abutment is firmly connected to a shaft 12, which extends through a hole 13 in the ground the recess 9 extends outward. On the threaded, emerging from the bottom 4 of the mold End of the shaft 12 a nut 14 is screwed, with the help of which a between the Abutment and the bottom of the recess 9 arranged spring 15 is biased. Instead of the pen can also be another elastically deformable member, e.g. B. a rubber cushion or an air cushion is used will. The pretensioned spring 15 holds the abutment 11 in its position.

The pressing process takes place as follows: After locking the side walls of the Form frame 2 and the filling of the at this time

7 8

point already connected from the bottom of the mold bottom 4 cap 26 made of metal, which sits on the core closed mold frame with the ceramic. Opposite the cap is in the with the raw material the mold cover 6 is first placed on the upper die firmly connected mold cover 6 in the mold frame a round opening 27 is provided,
and then simultaneously with the mold- 5 The gaps between the mold bottom 18 and the bottom are pressed continuously into the mold frame- sleeve 21 and between the sleeve 21 and the. When the mold cover 6 rests against the free core shoe 10 with the sealing upper end of the cores 8 (not shown here), the compression is a medium against the penetration of ceramic without the involvement of the cores, which are subsequently sealed as material.

Pre-compression is called, completed. 10 In FIG. 3 have a shaped lid 6 and a shaped bottom

At the end of the pre-compression, this device acts like 18 the starting position at the start of the pre-compression.

a simple punch press with which there is no compression. For the purpose of pre-compression, the

the molding compound is essentially only pressed into the mold cover 6 in the mold frame

Cover and bottom adjacent areas reached and at the same time raised the base plate 16, the

is, a depth effect of the compression pressure i ₅ via the spacer bolts 19 the mold bottom 18 in the

however, it is absent because the friction of the molding compound pushes in on the mold frame. The in the

Mold frame and the core walls, the air trapped with increasingly loose molding compound through the in

Mender compression of the molding compound increases, the openings 27 located on the mold cover

Pressing pressure consumes. escape outside. Except for the large openings 27

If now the mold cover 6 and mold bottom 4 after 20, a variety of

Termination of the pre-compression by pressing the number of smaller openings for air to escape

Stamp 3 and 5 are brought closer to each other, so each will be provided from the inside

while the cores 8 compressed in the longitudinal direction. Expand through to the outside of the wall to avoid any obstructions

to prevent the increase in cross-section occurring during upsetting.

the molding compound is placed between the cores 8 and 25 The length of the spacer bolts 19 is dimensioned so that neighboring cores and the side walls of the form- that after the necessary for the pre-compression frame 2 compressed in the transverse direction. Characterized the stroke of the ram 3 of the mold bottom 18 with the also in the middle area of the ceramic upper edge of the sleeve 21 is aligned and the basic raw material produced molding approximately the same plate 16 rests against the intermediate plate 17. In the dense packing of the clay grains achieved as in FIG. 4 is the pressing device after completion of the Vorreich of the rams 3 and 5 shown in the compression molding.

frame pressed mold bottom 4 and the mold pressing is continued by removing the mold cover 6. bottom 18 and shaped cover 6 continue towards one another

When the mold bottom 4 approaches and moves, the cores 8 are

Form cover 6 the upsetting pressure at a core 8 35 device upset. The caps 26 close the

Via the openings 27 in the mold cover, which are opened by the bias of the spring 15, so far that no

given value because the core in its further cross-ceramic material, however, continues to leak air

elongation is hindered, which z. B. can occur if can. At the same time, the

at this point the mold frame with a denser pack holding cap 26 for a central application of the

kung was filled, this core 8 can against the 40 compression pressure and for its even distribution

Effect of its spring 15 in the recess 9 in across the cross section of the core. The one with the cap

evade the mold bottom 4. 26 connected core support 8 a secures the core during

B ei the pressing device according to FIG. 3 is the core 8 rend of upsetting against buckling,
provided with a core support 8 a. The mold base During the upsetting process, the entire mold is made up of several individual base structures, ie base plate 16, intermediate plates, namely one with plate 17 and mold base 18, with which in FIG. 4 of the base plate 16 connected to the press plunger 3, showed mutual position in the mold frame with an intermediate plate 17 and the actual mold inserted, the intermediate plate being pushed away from the base 18, the base plate 16 and the mold base 18 lifting from their support, not shown. The 50 F i g. 5 shows the pressing device after completion, on which the intermediate plate 17 is slidable during the pressing process. In the event of a hindrance to transverse expansion, is. On the intermediate plate 17, which can also rest on the core with support not shown in this device, a cup-shaped sleeve 21 is provided when the spring 15 is pressed together towards the flange ring 20 when it overstresses the preload of the spring that steps through one in the bottom of the mold 18 55.

The opening 22 located in the mold frame is then pressed when the molded block is finished, press stretching is carried out. Inside the sleeve 21 is, as shown in Fig. 6, stamp5 with form cover6 and press ram3 closer can be seen, the core 8 with the Keraschuh 10 withdrawn. The base plate 16 also goes here slidingly guided. As with the device downwards and takes the mold bottom 18 with it. Da-Fig. 1 and 2, the core shoe 10 is on a counter 60 and the intermediate plate 17 also returns to the bearing 11 supported, the back by a preloaded basic position shown in Fig. 3, in which they Spring 15 is held in place. The abutment rests on their support. The kernels relax 11 and the shaft 12 are here however with a self, so that the mold is opened and the axial bore 23 is provided. This hole is used to lift the molded stone from the press cores as a guide for the axially through the core 8 and 65, for example by lifting the mold bottom an opening 25 in the bottom of the core shoe 10 with the shaped stone, in which the intermediate plate 17 stretching core support 8 a. At the free end of the lifted by the support, not shown Kerns8 (see Fig.3) is the core support8α with a will.

Claims (1)

9 10 The in Fig. The third embodiment shown in Fig. 7 is different from the one made exclusively from solid rubber differ from the previous one in the standing nuclei. The core is supported during the other form of formation of the nuclei. These are upset here via the fluid located in the space 32 provided with a hollow core support 28, which is fluid on the piston 39. The upsetting pressure increases as can be seen more clearly from FIG. 10, by a 5 over the value given by the spring 15, so Opening 29 in the bottom of the core shoe 10 extends. the piston 39 and thus also the core give way At the lower end, the core support 28 consists of the bottom, with the core shoe 10 having a cylinder a piston 30 made of one piece or is on a 31 and piston 30 and 39 move together, such attached. This piston 30 slides in a die on the cap 35 or on the core shoe downwardly extending cylinder 3i on the manio brought collars 36 and 37 prevent the under one tel of the core shoe 10. The space 32 below the considerable pressure standing between core support Piston is about the opening 33 with the hollow and core reaching liquid to the end space of the core support 28 in connection. Exit above that of the core. of the core shoe 10 is the core support 28 with preferential In the F i g. 9 is the device after completion as shown distributed over their length at a distance of 15 of the pressing process. Are the press rams 3 Neten lateral openings 34 are provided. and 5 withdrawn again, it relaxes On the free core facing the mold cover 6 and presses between the core end during upsetting of the core 8 is a support with the core support 28 and the liquid returned to the core Cap 35 connected. From this cap as well as from the cavity of the core support and the space 32 back. The bottom of the core shoe 10 extends annular 20 The strength of the webs of the shaped stone between the Collar 36 or 37 in corresponding recesses of the individual cores depends essentially on the in the core. Degree of filling with raw material. As with the device described above, the filling can also be increased by adjusting the filling height the core shoe 10 is enlarged in a cup-shaped sleeve above the core and the core off slidably guided, which is denoted here by 38. In the 25 produces less elastic material, so that the from the core shoe 10 downwardly protruding cylinder 31 core not already through during the pre-compression if the piston 30 is opposite another, the forces are compressed, which over the molding compound Piston 39 is provided, which the abutment 11 at on the free end of the core or via the friction the previously described devices correspond to the material acting on its lateral surfaces. It and like this by a pre-tensioned 3 °, cores of different lengths can also be understood Spring 15 is held in place. The turn when the degree of filling and thus the web space 32 between the piston 30 and 39 as well as the thickness across the cross-section of the shaped stone under the cavity of the core support 28 are intended to be different with a liquid. filled. The cores can have any cross-sectional shape The sleeve 38 holding the core is, like the sleeve 35, so that molded bricks with from the cylindrical 21 in the device described above, produced with different openings in the form of threes a flange ring 20 on the intermediate plate 17 can be loaded. solidifies. The intermediate plate rests again on the lower target of the pre-compression and the other supports, which are only shown schematically and which are achieved with closing compression of the cores. 40 are designated. +0 can be increased, the filling can Fig. 7 shows the pressing device at the beginning of the mold frame by shaking the mold frame Pressing process. Fonnboden 18 and shaped cover 6 loading and / or individual or all cores during the are found in their starting position. The pre-fill can be enlarged. The ceramic raw material is sealed in. The mold frame is lined with rubber on the inside Way as shown in FIG. 3 and 4, with the rubber lining on the mold walls only tert. In this case, however, the base plate 16 does not extend as far as the height of the fully pressed to the intermediate plate 17, but to which is by molded stone. In the areas where Formsie sleeve extending therethrough 38. In Fig. 8 the bottom and mold cover is sliding on the walls, loading device after completion of the pre-compaction, there is no rubber coating shown on the molding box. The molded cover 6 is now with the cap 5 ° walls so that metal surfaces slide on each other. 35 at the upper end of the core support 28 in contact, by a correspondingly profiled rubber covering and the mold bottom 18 is at the same height can rough the shaped stones in a known manner with the upper edge of the sleeve 38. or profiled surfaces are given on which- After pre-compaction, the base plate 16 will adhere particularly well to the mortar, with mold bottom 18 and mold cover 6 white 55 ter approached, the intermediate plate 17, as claims:
in Fig. 9, lifts from its support 40 and, as in the previously described device 1. Device for pressing hollow construction lines, the cores are compressed. When upsetting in a mold by means of cores expanding in cross-section, the piston 30 located at the lower end of each core 60 barer elastic cores, at which mold bottom support, places the piston 30 in the space 32 and / or cover into a mold frame in the hollow core support 28 located liquid can be pressed and the core with one end at the under pressure and presses it through the lateral ÖS mold bottom or cover is attached or with openings 34 in the core support between the core and its holder through this and core support, with the core below the pressure 65 with its fastening out of the molding, the liquid is detached from the core support and can be pulled out, characterized in that it bulges (FIG. 9). With this design of the core, that the or each elastic core (8) is so much less force for upsetting the cores that it is compressible, and that . - - 709 549/251