Device for producing molded concrete blocks, and method for producing molded concrete blocks

Abstract

The invention relates to a device for producing molded concrete blocks, comprising • a mold lower part (5) in which at least one mold cavity (11) is formed and • a mold upper part (19) comprising at least one pressure piece (21) with a lower face (31) facing the mold cavity (11), an upper face (33) facing away from the mold cavity (11), and lateral surfaces (35), wherein the pressure piece (21) has a plurality of fluid openings (43) on the lower face (31) and / or on the lateral surfaces (35) and is designed to engage into the mold cavity (11) such that when the pressure piece (21) is engaged, a fluid can be introduced into the mold cavity (11) from the plurality of fluid openings (43) and / or when the pressure piece (21) is engaged, a fluid can be discharged out of the mold cavity (21) from the plurality of fluid openings (43).

Description

[0001] DEVICE FOR PRODUCING CONCRETE SHAPED BLOCKS AND METHOD FOR PRODUCING CONCRETE SHAPED BLOCKS

[0002] The invention relates to a device with a lower mold part and a upper mold part for producing concrete blocks and a method for producing concrete blocks.

[0003] A device for producing concrete blocks comprises a lower mold and an upper mold. The lower mold is open at the top and bottom, with the bottom closed by a horizontal base. The lower mold comprises one or more cavities into which the concrete mix is ​​poured. The upper mold has a stamping unit for compacting the concrete mix in the cavities. The stamping unit comprises pressure pieces that can engage with the cavities of the lower mold. Pressure pieces are also called pressure plates. The device compacts the concrete mix by means of the engaging pressure pieces to form one or more concrete blocks.

[0004] The pressure pads used in production serve as stamping plates to form the surface of the concrete blocks. Conventionally, the pressure pad is a cut and dimensioned shaped sheet. The surface of the pressure pad, which rests on the concrete mix, can be milled and can be smooth, for example, or with three-dimensional contours or embossing.

[0005] During block production, the concrete mix is ​​poured into the upper openings of the mold cavities and then compressed by the pressure plates, which are lowered into the mold cavities through the upper openings using a load-bearing unit. Vibration of the base solidifies the concrete mix into dimensionally stable concrete blocks. The concrete blocks are then removed from the mold through the lower openings of the mold cavities, and the pressure plates are removed.

[0006] A typical process for forming concrete blocks from layered concrete mix involves filling the mold using a first filling carriage. The concrete mix is ​​pre-compacted by immersing the pressure pad. The load is then lifted with the pressure pads to enable filling of the mold using a second filling carriage. Layering the concrete mix creates a two-layer concrete block with a core concrete and a facing concrete applied on top. After filling, the main compaction of the layered concrete mix takes place. The pressure pad is immersed in the mold cavity, and the concrete mix is ​​compacted by pressure from above and shock vibration. Compaction continues until the concrete mix has shrunk to the desired, product-dependent block height. The mold is then lifted to demold the block layer, with the pressure pad still resting on the block surface. The pressure pad is then lifted off the block.In the exemplary production described, the properties of the demoulded block are determined by the concrete mix filled in and the compaction process.

[0007] Problems during production can arise from the pressure pad becoming stuck to the compacted concrete mix during demoulding. When the pressure pad is lifted from the block surface, the negative pressure can damage the block surface, with sections of the surface being torn out with the lifting pressure pad. The risk of surface damage can be reduced by lifting the pressure pad slowly, which not only reduces the negative pressure but also the production speed. Furthermore, the production process described above limits the options for adjusting special properties of the blocks, such as color, color gradient, chemical properties, via the filling process or even varying them during the production process, since the same blocks are produced in every production cycle.The moisture values ​​of the facing concrete are also limited to a narrow range, as excess water cannot escape from the mold cavity and the stone surface.

[0008] CN 1 13 547 612 A discloses a method and apparatus for producing bricks. During brick production, materials are distributed in a mold cavity to form a blank, a press head is pressed down into the mold cavity to compact and press the blank, and water is pumped out.

[0009] DE 10 2007 030 324 A1 shows a device for producing cement products, in particular tiles, comprising a mold and a press with a press head as well as drainage devices in the press head.

[0010] EP 1 281 494 A2 shows a device for compressing powder, such as is used for the production of ceramic tiles. A punch with a porous surface allows the powder to be deaerated during compression.

[0011] E 88 09 498 U1 shows a device for producing a concrete layer. The press plate is made of an elastically deformable material to facilitate its removal.

[0012] The object is to provide an improved device and an improved method for solving the above problems. To solve the object, a device for producing precast concrete blocks is provided. It comprises a lower mold part in which at least one mold cavity is formed, and an upper mold part comprising at least one pressure piece with a bottom side facing the mold cavity and an top side facing away from the mold cavity, as well as side surfaces. The pressure piece can be lowered such that it engages in the mold cavity. The pressure piece has a plurality of fluid openings on the bottom side and / or on the side surfaces, wherein a fluid can be conducted from the plurality of fluid openings and / or a fluid can be discharged into the plurality of fluid openings.

[0013] The method for producing a concrete block comprises the following steps: filling a mold cavity with a concrete mixture; compacting the concrete mixture by means of a pressure piece which is lowered, engages in the mold cavity and presses on the concrete mixture; directing a fluid from fluid openings in the pressure piece onto the concrete mixture or diverting a fluid from the concrete mixture into fluid openings in the pressure piece; lifting the pressure piece from the compacted concrete mixture.

[0014] The pressure piece, which is lowered into the mold cavity, also known as the mold chamber, and engages with it to compact the concrete mix, has an additional function: It directs a fluid, i.e. a liquid or a gas, onto the concrete mix or from it. The fluid directed from or drained into the plurality of fluid openings is released from the fluid openings or sucked into them when the pressure piece is lowered and resting on the concrete mix. Introduction and drainage advantageously take place at the beginning, during or at the end of the compaction step, when the concrete mix is ​​in the mold cavity, and before demolding or formwork removal, i.e. the removal of the concrete mix compacted into blocks from the mold. Alternatively, the fluid can also be directed onto the concrete mix that has already been compacted into block before or when the pressure piece is lifted off.

[0015] The fluid guided through the fluid openings on the underside of the pressure piece is directed onto the surface of the concrete mix on which the pressure piece rests. This creates further design freedom for the concrete block that goes beyond the conventional compaction process and the selection of the concrete mix. Advantageously, the concrete block can be colored or other properties of the concrete block can be changed, allowing the concrete block to be provided with additional functions. For example, an impregnation that creates a hydrophobic surface or a luminescent agent can be applied during the forming and / or demolding process. In one embodiment, the device is designed to introduce colors or liquid concrete mix additives, in particular to change the surface quality of the block.The introduction of the fluid also offers the advantage of varying the design and / or properties of the blocks during the production process by varying the introduction, without requiring any equipment retooling. In other words, the block design can be modified in terms of color, color gradient, or fine surface structure after each cycle. This results in greater block product variety despite using the same mold and the same concrete mix. This, of course, also means greater flexibility.

[0016] The fluid is a liquid or a gas. By introducing a gas, such as compressed air, between the die and the formed block during the removal of the die, the risk of surface damage to the block is reduced and the speed of the lifting die can be increased. Applying compressed air is an aid during demolding because it allows for better and faster demolding, improved product quality, and faster cycle times.

[0017] In the designs described above, the fluid is typically introduced or discharged through the fluid openings on the underside. Alternatively or additionally provided fluid openings on the side surfaces allow fluid introduced between the pressure piece and the mold cavity wall to reduce friction during the compaction step. In this case, the fluid on the pressure piece flanks is a lubricant or lubricating oil and minimizes wear between the pressure piece and the mold cavity walls. Compressed air from the fluid openings on the side surfaces can facilitate the removal of the pressure pieces from bricks that have not yet been demoulded.

[0018] The engaging pressure piece allows the fluid from the concrete mix to be diverted into the fluid openings, reducing the moisture content of the concrete mix in the mold cavity and, in particular, absorbing liquid from the surface. This allows for a moister, and therefore easier to fill, concrete mix, especially facing concrete, from which moisture is removed by the pressure piece after filling.

[0019] The advantages described above are also accompanied by higher cycle rates and longer service life.

[0020] In one embodiment, the upper mold part comprises at least one fluid reservoir in the pressure piece, which includes a fluid connection on the top side of the pressure piece. The majority of the fluid openings extend to the fluid reservoir, so that the fluid can be directed from the fluid reservoir through the fluid openings and vice versa. The pressure piece is supplied with the fluid or removed via the fluid connection. The fluid reservoir distributes the fluid to the fluid openings or collects the sucked-in fluid before being removed via the fluid connection. In addition, the hollow fluid reservoir reduces the weight of the pressure piece.

[0021] The fluid openings can be formed as holes in the underside and / or the side surfaces. The holes can extend straight from the reservoir to the underside or to the side surfaces. Due to their typically small diameter, they can also be referred to as "pore channels." The fluid openings are arranged in a grid-like pattern, i.e., in a regular pattern, or irregularly on the underside of the printed part. The arrangement on the side surfaces can also be regular or irregular. There are several degrees of freedom in the design of the fluid openings. For example, they can be round, elliptical, or rectangular.

[0022] Alternatively, a porous layer can form the majority of the fluid openings. The porous layer has small cavities that are interconnected like a sponge, through which the fluid can flow. In one embodiment, such a porous layer can be formed by interconnected particles, between which the cavities for the flowing fluid extend.

[0023] The printed parts described above can be manufactured additively, for example, through 3D printing. This allows for a more flexible design of the printed part geometry than with conventional manufacturing. This method also allows for a hollow support structure to be incorporated into the printed parts, and their printing surface can be designed with holes or porosity.

[0024] In one embodiment, the device is designed to conduct the fluid in a timed manner from the plurality of fluid openings, in particular into the mold cavity, or to divert it from the mold cavity into the plurality of fluid openings, such that the conduction or diversion only occurs when the pressure piece is lowered onto the concrete mixture and advantageously engages the mold cavity. Through the timed operation, the fluid is directed onto the concrete mixture or diverted from the concrete mixture in the mold cavity in a timed or time-dependent manner when the pressure piece is lowered and rests on the concrete mixture.

[0025] In the process for producing a precast concrete part, the fluid is introduced or discharged when the pressure piece rests on the concrete mixture.

[0026] This step is advantageously performed in a timed manner during the phase in which the pressure piece rests on the concrete mix. The concrete mix is ​​advantageously in the mold cavity during this step, so that the step can be performed in conjunction with compaction.

[0027] In one embodiment, the fluid can be directed onto the concrete mix to color the concrete mix and / or change its surface texture. This step can be performed multiple times, so that different fluids are introduced one after the other. Spatial differentiation is also possible, so that one fluid is directed onto one or more areas on the surface of the concrete mix, and another fluid is directed onto another or several other areas on the surface of the concrete mix.

[0028] In an alternative embodiment, the fluid is introduced as a lubricant between the side walls of the mold cavity and the side surfaces extending between the top and bottom of the pressure piece. In one embodiment, one fluid is introduced into the concrete mix, and another fluid is introduced as a lubricant between the side walls of the mold cavity and the pressure piece. In one embodiment, compressed air is introduced between the pressure piece and the concrete mix during lift-off to assist the detachment of the pressure piece from the block and prevent cracking of the surface.

[0029] In one version, liquid is sucked out of the concrete mix to reduce the moisture content of the concrete mix and to remove liquid standing on the surface.

[0030] Of course, the process can also combine different introduction or discharge steps, and the pressure piece can be designed so that different fluids are introduced or discharged using the same pressure piece. Such a pressure piece can have one or more fluid reservoirs. For example, liquid can first be sucked out of the concrete mix, followed by a color and then an impregnation. Another example involves first applying colors and then forcing compressed air between the block and the pressure piece.

[0031] Below, some examples are explained in more detail using the drawings. They show:

[0032] Figure 1 is a perspective side view of an embodiment of a device for producing concrete blocks,

[0033] Figure 2 shows an embodiment of a pressure piece in a schematic sectional view,

[0034] Figure 3 shows the embodiment of a pressure piece from below,

[0035] Figure 4 shows a region of an embodiment of a pressure piece from below, Figure 5 shows a region of another embodiment of a pressure piece from below,

[0036] Figure 6 shows a region of another embodiment of a pressure piece from below,

[0037] Figure 7 shows a further embodiment of a pressure piece in a schematic sectional view, and

[0038] Figure 8 shows a further embodiment of a pressure piece in a schematic sectional view.

[0039] In the figures, identical or functionally equivalent components are provided with the same reference numerals.

[0040] With reference to Figure 1, a first embodiment of a device for producing concrete blocks is explained below.

[0041] The device is shown in a perspective side view and, as is customary in the art, comprises a vibrating table 1 on top of which is located a production board 3. Arranged on the production board 3 is a lower mold part 5 which has an exchangeable insert 7 with recesses surrounded by a frame 9, wherein the insert 7 is exchangeable in the frame 9. The recesses surrounded by the frame 9 form mold cavities 11. On two opposite sides, the frame 9 has holding struts 13 which create a connection between the frame 9 and a respective receptacle 15. In one embodiment, the holding struts 13 can also be part of the receptacles 15. The two receptacles 15 are arranged on four guide columns 17 which, as is customary in the art, are arranged in the region of the corners of the lower mold part 5 and surround the area outside the vibrating table 1.Opposite the cavities 11 is the upper mold part 19, which has a plurality of plate-shaped pressure pieces 21, the dimensions of which approximately correspond to the recesses of the mold cavities 11. The pressure pieces 21 are connected via pressure stamps 23 to a loading device 25, which in turn is connected on the side facing away from the upper mold part 19 to a ram plate 27, which is guided on the guide columns 17 and can be actuated by a hydraulic press via a stamp 29.

[0042] During concrete block production, the mold cavities 11 are filled with a concrete mixture. The concrete mixture is compacted by inserting the pressure pieces 21, and refilling produces a layered concrete mixture. After filling, the main compaction of the layered concrete mixture takes place. The pressure pieces 21 are inserted into the mold cavities 11, and the concrete mixture is compacted by pressure from above and shock vibration of the moving vibrating table 1, thus forming blocks. The mold is then raised to demould the block layer. The pressure pieces 21 are then lifted off the blocks.

[0043] The pressure pieces 21 are designed such that they can introduce a fluid, i.e. a liquid or a gas, into the mold cavities 11 or discharge it therefrom.

[0044] Figure 2 schematically shows an embodiment of a pressure piece 21 in a lateral sectional view. The pressure piece 21, also referred to as a pressure plate, has features in superimposed layers with different functionality. The pressure piece 21 comprises a bottom side 31 facing the mold cavity 11 (not shown in Figure 2) and an opposite top side 33 as well as peripheral side surfaces 35 between them. A fluid reservoir 37 is arranged inside the pressure piece 21, to which at least one fluid connection 39 extends on the top side 33. The fluid reservoir 37 is designed as a cavity inside the pressure piece 21. Support structures 47 can optionally be provided, for example struts on the reservoir walls and / or columnar supports in the reservoir interior. A honeycomb structure is also conceivable. The support structures 47 are shown in dashed lines in Figure 2.Optionally, structures are provided that support the distribution of the fluid in the fluid reservoir 37. The fluid reservoir 37 in the pressure piece 21 is a layer for stabilization and fluid distribution.

[0045] The upper side 33 is the mounting side of the pressure piece 21, to which it is attached to the pressure stamp 23 (not shown in Figure 2). It can have threads and bores as fastening means 41 in order to attach it to the pressure stamp 23, for example by screw connections. The fluid connection 39 can be designed as a through-bore to the fluid reservoir 37. A fluid can be introduced into the fluid reservoir 37 or sucked out of it via the fluid connection 39. The mounting side, also referred to as the screw-on side, is used to supply the fluid reservoir 37 with fluids or to remove them from the fluid reservoir 37, for example by means of a pumping or suction device (not shown in Figure 2), which can be a component of the device. The mounting side is a layer for fixing and supplying and / or removing fluid.

[0046] The underside 31 is the surface of the pressure piece 21, which is used to press onto the concrete mix in the mold cavity 11. In this exemplary embodiment, it has a circumferential bevel 45. The underside is a layer that forms the block surface. A plurality of fluid openings 43 on the underside 31 extend to the fluid reservoir 37. In this exemplary embodiment, the fluid openings 43 are regularly arranged. The perforated layer between the fluid reservoir 37 and the underside 31 has holes with a small diameter, which can also be referred to as pore channels. The layer with the fluid openings 43 designed as holes can, for example, have a thickness of approximately 9 mm. Overpressure or underpressure, in particular due to the introduced or sucked-off fluid, at the fluid connection 39 causes the fluid to escape from the fluid openings 43 or to suck the fluid from the mold cavity 11 into the fluid openings 43.The holey, permeable layer with the fluid openings 43 is a functional layer by means of which the fluid is introduced into the mold cavities 11 or discharged therefrom.

[0047] During operation, the fluid is filled through the fluid connection 39, which is designed as a through-bore, is distributed in the fluid reservoir 37 with its filling and support structure, is conveyed through the fluid openings 43 to the underside 31, which serves as the mirror side, and exits from the fluid openings 43. Alternatively, during operation, the fluid can be sucked in through the fluid openings 43. The supply and discharge of the fluid into the fluid reservoir 37 is carried out, for example, by a pumping or suction device, which is advantageously part of the device.

[0048] Figure 3 shows the underside 31 of the pressure piece 21 from Figure 2. This is the mirror side that rests on the concrete mixture. The fluid openings 43 are arranged in a grid pattern, i.e. in a regular pattern, on the underside 31 and extend to the bevel 45. In an alternative embodiment, they can also be spaced further from the bevel 45 than from other fluid openings 43. In this exemplary embodiment, the fluid openings 43 are arranged on the smooth mirror surface in a rectangular pattern as a regularly arranged structure. With a larger number of fluid openings 43, the distances between the fluid openings 43 would be smaller. With a larger number of fluid openings 43, the distances between the fluid openings 43 would be larger. The arrangement of the fluid openings 43 can depend on the fluid used, in particular whether it is a liquid or a gas, and can be adapted to user-specific requirements.

[0049] In an alternative embodiment, the fluid openings 43 may be arranged on the underside 31 irregularly, equal to or similar to a random distribution, instead of in a regular pattern.

[0050] Figures 4 to 6 show a section of the undersides 31, i.e., the mirror sides, of various embodiments of a pressure piece 21, which differ in terms of the shape of the fluid openings, in particular their bore cross-section. Figure 4 shows fluid openings 43 with a rectangular contour. Figure 5 shows fluid openings 43 with a round contour. Figure 6 shows fluid openings 43 with an elliptical contour.

[0051] Figure 7 schematically shows a further embodiment of a pressure piece 21 in a sectional view.

[0052] The pressure piece 21 has more than one fluid reservoir 37 with a fluid connection 39 on the top side 33. A plurality of fluid openings 43 on the bottom side 31 extend to the fluid reservoirs 37. The fluid openings 43 are formed in a porous layer 49 on the bottom side 31. The porous layer 49 has small cavities that are connected to one another like a sponge, through which the fluid can flow. Such a porous layer 49 can also be formed by interconnected particles between which the cavities extend. It can be formed, for example, by sintering. By providing several fluid reservoirs 37, different fluids can be introduced into the concrete mixture in a spatially differentiated manner.

[0053] The embodiments described above are designed so that a fluid is released or absorbed via the fluid openings 43 during the production process.

[0054] When producing a concrete block, the mold cavity 11 is filled with a concrete mixture. The concrete mixture is compacted by the lowered pressure piece 21, which engages in the mold cavity 11 and presses on the concrete mixture. Optionally, another concrete mixture can be poured in as facing concrete. The concrete mixture is compacted by the pressure piece 21, which engages in the mold cavity 11 and presses on the concrete mixture. Compaction is assisted by vibration. The formwork is then demolded and the pressure piece 21 is lifted off the compacted concrete mixture, which forms the block. During the production of the concrete block, when the pressure piece 21 engages, a fluid is directed from fluid openings 43 in the pressure piece 21 into the mold cavity 11 and / or when the pressure piece 21 engages, a fluid is drained from the concrete mixture into the fluid openings 43. The introduction can also take place when the stone has already been demoulded by the pressure piece 21 still in place.

[0055] The fluid introduction or discharge into or from the mold cavity 11 takes place in a time-dependent manner, so that it advantageously takes place when the pressure piece 21 engages in the mold cavity and rests on the concrete mixture so that the fluid introduction or discharge takes place on or from the concrete mixture.

[0056] During compaction, a liquid fluid can advantageously be applied to the surface of the concrete mix. Such a fluid can be a dye, a concrete mix additive for creating a functional surface, such as an impregnation, or something else.

[0057] The introduction of colors enables the production of bricks in contrasting colors. The surface of the bricks can be colored completely in one color or in a color mix, also known as a color mix. The latter can be achieved if different colors are introduced one after the other. In a pressure piece 21 with several fluid reservoirs 37, each of which is only connected to a portion of the fluid openings 43, the fluid can be applied to the concrete mix in a spatially differentiated manner, so that, for example, one color is only applied to certain areas of the brick surface or different colors are applied to different areas. In this way, bricks can also be produced in a color mix. The colors can be positioned individually.In one embodiment, the positioning of color spots on the stone surface can be randomized by varying the color composition and / or amount of color in the fluid reservoir(s) 37 during production.

[0058] The use of a pressure piece 21 for introducing one or more fluids offers the user greater flexibility and a greater product variety of blocks produced with the same mold and the same concrete mixture. The block design can be easily modified by selecting the fluid, even in each production cycle, particularly with regard to color, color gradient, and fine surface structure. This reduces the time required to produce different block designs, as time-consuming retooling of the device for different designs is no longer necessary. The block can additionally or alternatively be formed with an additional functional surface, for example, an impregnation, i.e., a hydrophobic surface, or a luminous surface by applying a light source.In another production embodiment, compressed air is directed through the fluid openings 43 onto the concrete mix to enable faster demolding. Compressed air also reduces the risk of surface damage when lifting the pressure piece 21, so that the surface of the block is sealed and no tearing of the block surface occurs. This results in increased production quality and faster cycle times during production.

[0059] Of course, the introduction of a liquid fluid, whether for coloring or creating a functional surface, can also be followed by the introduction of compressed air to combine the aforementioned advantages. The compressed air also cleans the fluid openings 43 during each production step, thus reducing the risk of clogging during production. This process can be carried out with a pressure piece 21, only one fluid reservoir 37, or with multiple fluid reservoirs 37.

[0060] In a further embodiment, liquid is sucked in from the concrete mix through the fluid openings 43 and drained away. This procedure, with particularly moist concrete mixes during the compaction process, allows excess liquid, especially water, to be sucked away from the stone surface. This method can be carried out with a pressure piece 21 with only one fluid reservoir 37 or with multiple fluid reservoirs 37. The draining can take place before introducing another fluid, for example, for coloring.

[0061] Figure 8 schematically shows a further embodiment of a pressure piece 21 in a sectional view. In this embodiment, the pressure piece 21 has two separate fluid reservoirs 37, each with fluid connections 39. One is arranged circumferentially and adjacent to the side surfaces 35. Fluid openings 43, designed as channels, extend from the fluid reservoir 37 to the side surfaces 35. Another fluid reservoir 37 is arranged in the central region of the pressure piece 21. Fluid openings 43, designed as channels, extend from the underside 31 to this fluid reservoir 37.

[0062] The provision of two fluid reservoirs allows the use of two different fluids. Fluid designed as a lubricant is discharged through the fluid openings 43 on the side surfaces 35 to reduce friction between the pressure piece 21 and the walls of the mold cavity 11 (not shown in Figure 8). For example, paint and / or compressed air can be discharged and / or liquid can be suctioned off via the fluid openings on the underside 31.

[0063] It is also possible, in one embodiment, to provide fluid openings only on the side surfaces in order to reduce friction during compression.

[0064] The features specified above, those in the claims, and those evident from the illustrations can be advantageously implemented both individually and in various combinations. The invention is not limited to the described embodiments, but can be modified in many ways within the scope of expert knowledge.

[0065] Reference symbol

[0066] I Vibrating table

[0067] 3 Production board

[0068] 5 Mold base

[0069] 7 Use

[0070] 9 frames

[0071] II Mold cavity

[0072] 13 Support strut

[0073] 15 recording

[0074] 17 Guide column

[0075] 19 Upper mold part

[0076] 21 Pressure piece

[0077] 23 printing stamps

[0078] 25 Loading device

[0079] 27 Bärplatte

[0080] 29 stamps

[0081] 31 subpage

[0082] 33 Top

[0083] 35 side surface

[0084] 37 Fluid reservoir

[0085] 39 Fluid connection

[0086] 41 Fasteners

[0087] 43 Fluid opening

[0088] 45 chamfer

[0089] 47 Support structure porous layer

Claims

Claims:

1. Device for the production of concrete formwork blocks with - a mold base (5) in which at least one mold cavity (11) is formed, and - comprising a mold upper part (19) comprising at least one pressure piece (21) with a bottom surface (31) facing the mold cavity (11) and a top surface (33) facing away from the mold cavity (11) as well as side surfaces (35), wherein the pressure piece (21) is retractable such that it engages in the mold cavity (11), and wherein the pressure piece (21) has a plurality of fluid openings (43) on the bottom surface (31) and / or on the side surfaces (35) and wherein a fluid is conductable from or into the plurality of fluid openings (43).

2. Device according to claim 1, wherein, with the pressure piece (21) lowered, the fluid can be directed from the plurality of fluid openings (43) into the mold cavity (11) or, with the pressure piece (21) lowered, the fluid can be directed from the plurality of fluid openings (43) out of the mold cavity (11).

3. Device according to claim 1 or 2, wherein the upper part of the mold (19) comprises at least one fluid reservoir (37) in the pressure piece (21) which includes a fluid connection (39) on the upper side (33) of the pressure piece (21), and wherein the majority of the fluid openings (43) extend to the fluid reservoir (37).

4. Device according to one of the preceding claims, wherein the fluid openings (43) are formed as holes in the underside (31) and / or in the side surfaces (35).

5. Device according to one of the preceding claims, wherein the fluid openings (43) are arranged in a grid pattern or irregularly on the underside (31) of the pressure piece (21).

6. Device according to one of the preceding claims, wherein the fluid openings (43) are round or elliptical or rectangular.

7. Device according to one of the preceding claims, wherein a porous layer (49) forms the majority of the fluid openings (43).

8. Device according to one of the preceding claims, which is configured to direct the fluid in a timed manner from the plurality of fluid openings (43) or to direct it from the mold cavity (11) into the plurality of fluid openings (43).

9. Device according to one of claims 3 to 8, which is configured to direct the fluid into the pressure piece (21) via the fluid connection (39) or to draw the fluid out of the pressure piece (21) via the fluid connection (39).

10. Device according to one of the preceding claims, which is configured to direct compressed air, paint, concrete mix additive or lubricant from the majority of the fluid openings (43) or is configured to drain liquid from the mold cavity (21).

11. Method for manufacturing a concrete formwork block comprising: - Filling a mold cavity (11) with a concrete mixture, - Compaction of the concrete mixture by a pressure piece (21) which is lowered, engages in the mold cavity (11) and presses on the concrete mixture, - Directing a fluid from fluid openings (43) in the pressure piece (21) onto the concrete mixture or diverting a fluid from the concrete mixture into fluid openings (43) in the pressure piece (21), and - Lifting the pressure piece (21 ) from the compacted concrete mixture.

12. Method according to claim 11, wherein the concrete mixture is in the mold cavity (11) when guiding or diverting the fluid.

13. Method according to claim 11 or 12, wherein the fluid colors the concrete mixture or changes its surface texture or alters its chemical or physical properties.

14. Method according to claim 11 or 12, wherein the fluid is directed as a lubricant between lateral mold cavity walls and side surfaces (35) of the pressure piece (21).

15. Method according to claim 11 or 12, wherein compressed air is directed between the pressure piece (21) and the concrete mixture.

16. Method according to claim 11 or 12, wherein liquid is extracted from the concrete mixture.

17. Method according to any one of claims 11 to 16, wherein the fluid is directed out of the fluid openings (43) or is directed into the fluid openings (43) in a timed manner.

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