EP0670763A1

EP0670763A1 - Method and device for producing concrete pipes of uniform length

Info

Publication number: EP0670763A1
Application number: EP94929501A
Authority: EP
Inventors: Giuseppe Colle
Original assignee: COLLE SpA
Current assignee: COLLE SpA
Priority date: 1993-09-30
Filing date: 1994-09-30
Publication date: 1995-09-13
Also published as: WO1995009073A1

Abstract

The invention concerns a method and device for producing concrete pipes of uniform length, the device having a core (1), an outer wall (2) and a pressure ram (11). The core (1) is displaceable coaxially inside the outer wall (2) and forms, together with the outer wall (2), an annular space in which the concrete pipe (T) is moulded. A significant innovation in the method proposed is that fact that the concrete is fed into the annular space through an impeller wheel (7, 7') which is mounted on top of the core (1) and creates, towards the end of the pipe-production process, a concrete-free space in which is collected the excess concrete displaced by the ram (11) when it closes off the annular space. This prevents, in particular, excess concrete from dripping on to the inside wall of the pipe or falling on to the floor of the machine, thus avoiding the need to clean these surfaces.

Description

Method and device for the production of concrete pipes of uniform height

description

The invention relates to a method and a device for the production of concrete pipes of uniform height with a core, an outer jacket and a press die, the core being displaceable coaxially within the outer jacket and forming an annular space with the outer jacket for forming a concrete pipe.

A fundamental innovation of the method according to the invention is that an impeller which operates the concrete filling and which is attached to the upper part of the core creates a free space for receiving the excess concrete without impairing the quality of the concrete pipe produced and without contaminating machine parts.

With the previous concrete pipe forming machines, it is practically impossible to regulate and tare the filling of the concrete in such a way that the concrete quantity required for a uniform vibro compaction and for a uniform pipe height is exactly achieved. Pipes are obtained which have uniform technical properties due to uniform vibro compaction, but the overall height of which differs by a few centimeters due to small differences in the amount of concrete poured and compressed.

In order to overcome this disadvantage, an impeller for distributing the concrete is attached to the upper part of the mandrel, which is shaped in such a way that the filled concrete is distributed not only radially but also in height in order to completely fill the pipe casting mold at the pipe end to ensure before starting with the final compression, with which the final height is specified.

REPLACEMENT BLAπ (RULE 26) A uniform pipe height is achieved in that the predetermined height is already loaded with the concrete to be compressed when the press ram is lowered to this height.

When lowering the mandrel and the attached impeller, however, the excess concrete pressed against the inner wall of the press ram falls back onto the impeller, so that the

Inside walls of the manufactured concrete pipe as well as the bottom of the machine become contaminated with concrete residues, which necessitates continuous cleaning and material loss.

The main aim of the present invention is to provide a method and a device for producing concrete pipes with uniform technical properties and always uniform height, the excess concrete required not adversely affecting the quality of the pipes produced.

In particular, it should be prevented that the excess concrete drips onto the inner walls of the concrete walls produced or falls onto the floor of the machine, which is associated with a corresponding cleaning effort.

Another object of the present invention is to catch the excess concrete and reuse it when pouring the next pipe.

In addition, the present invention is intended to eliminate the stoppages which are caused by the unavoidable excess of concrete or by the cleaning of the contaminants associated therewith. These and other objectives are achieved with the method according to the invention and the device proposed for its implementation. The use of an impeller is provided, with which a suitable space for receiving and collecting the excess concrete material is created, so that it can be reused when casting the next tube.

The collecting space created by the impeller for the excess concrete can, for example, have the shape of an annular groove arranged near the core edge by suitable shaping of the impeller.

It is also within the scope of the invention to make the collecting space concave by means of a different structural shape of the impeller, wherein at the same time an annular collecting area can also be provided on the circumference of the core.

An advantageous further development of the solution according to the invention is to provide the press ram with wipers so that the excess concrete which settles on the press ram can be stripped off the press ram and used for the casting of the next concrete pipe.

The invention is explained in more detail below on the basis of the exemplary embodiments shown in the drawing. Show it:

Fig. 1 is a side view of a portion of an axially sectioned mold for concrete pipes, in which an impeller for horizontal distribution of the concrete is installed, which are provided with outer scraper plates which ensure the formation of a gutter or drainage groove to absorb the excess concrete;

FIG. 2 shows a top view of the casting mold according to FIG. 1;

Fig. 3 is a side view of a portion of an axially cut mold shown in Figure 1 during the manufacturing phase, in which the excess concrete is pressed by the press ram into the groove previously formed by the impeller.

4 shows a side view of a partial area of a cut mold for concrete pipes, in which an impeller for the radial distribution of the concrete is installed, which also distributes the concrete over its own working surface, so that the press ram has a sufficient amount of concrete to be pressed finds before it reaches bottom dead center;

FIG. 5 shows a top view of the casting mold according to FIG. 4;

6 is a side view of a portion of the axially cut mold shown in FIG 4 during the operation of the press ram to form the upper tube edge.

7 shows a side view of a structure for the press ram in axial section with a pair of wipers for bringing together and recovering the excess concrete that accumulates when pouring concrete pipes;

Fig. 8 is a plan view along the section line II - II according to FIG. 7, wherein one stripper is cut and the other stripper is shown in a top view;

Fig. 9 is a side view of the upper part of the mold for concrete pipes along the cutting line

III - III according to Figure 8, wherein the structure is inserted into the outer shell of the mold.

Fig. 10 is a side view of the upper part of the mold according to FIG. 9, with the press ram in its fixed lowest position, and

11 is a partially sectioned side view of the mold in the position in which the core and the press ram with the structure are in their respective starting positions.

Matching individual parts are denoted in each case with the same reference numerals.

The method according to the invention can be carried out both with an impeller 7, which forms an annular collecting space on the outer edge of the core head 3 for receiving the excess concrete, and with an impeller 7 ', in the center of which the excess concrete can be accommodated.

In Fig. 1, a mold for concrete pipes is shown, which has a cylindrical core 1 and an outer jacket 2, in which the core 1 is arranged coaxially. The core 1 is provided with a core head 3 with a reduced diameter, which carries and guides a drive shaft 4. The core head 3 is connected to the cylindrical part of the core 1 via an annular disk 5 connected, which preferably sinks inwards and is provided with a bead 6 in the embodiment shown here.

An impeller 7, which consists of an impeller body with an edge 8 and has blades 9 for distributing the supplied concrete and stripping plates 10, is firmly connected to the drive shaft 4. The illustrated mold also has a press die 11 which is provided with a cylindrical guide 12 which forms a cavity 13. The press ram is designed so that it gives the tube T to be shaped the desired strength and gives the tube end or the tube edge the desired shape.

Using the impeller 7 shown in FIGS. 1 to 3, the method according to the invention comprises the following operations:

At the beginning of the tube production, the outer jacket 2 is firmly connected to a work surface, while the core 1 is flush with a lower mold surface, not shown, of the mold.

The concrete is fed into the mold from above using conventional means, so that it falls on the impeller 7 arranged above the core head 3.

With the beginning of the concrete supply, the rotation of the impeller 7 and the gradual upward movement of the core 1 also begin, so that the supplied concrete is thrown against the inner wall of the outer casing 2. In a manner known per se, the concrete pipe T is continuously shaped with the upward movement and the vibration of the core 1 up to its upper edge. The core 1 comes near the top of the part to be molded Concrete pipe T, the concrete supply is stopped. The vane wheel 7 continues to rotate about its axis in this phase, so that it distributes the material still present on it with the blades 9 and exposes an annular channel freed from the concrete conglomerate with the outer scraper plates 10.

As shown in FIG. 1, the impeller 7 is now stopped and the press ram 11 is lowered, which compresses the concrete supplied by the impeller 7 into the annular space delimited by the core 1 and the outer casing 2. It can be seen that the press ram 11 displaces the excess amount of concrete C which is not required or required for the production of a concrete tube via the edge bead 6. There, however, the ring-shaped channel has previously been exposed by the scraper plates 10 of the impeller 7, so that the excess concrete C is pressed by the press ram 11 via the bead 6 into the area above the ring disk 5.

As shown in Fig. 3, the ram 11 is lowered to the height of the bead 6 of the core 1 to give the pipe to be molded the desired compression and height. 3 clearly shows that the excess concrete C is collected at the point which was previously created by the rotation of the stripping plates 10 of the impeller 7, as a result of which the excess concrete falls off and contamination associated therewith is reliably prevented.

When the manufacture of a tube is complete, the core 1 lowers together with the impeller 7 and the excess material C collected on the top of the core without this material being deposited on the inner surface of the tube. After the finished concrete pipe is removed and the core 1 is in relation to the outer jacket 2 in is in its lower starting position, the concrete supply is restarted for the production of the next concrete pipe and the impeller 7 is set in rotation again, the previously collected excess material C being reused together with the new material for casting a new pipe so that no material is lost.

The use of the impeller 7 'shown in FIGS. 4 to 6 necessitates an adaptation of the work steps of the method according to the invention. The special design of this impeller makes it possible to distribute the concrete over its own rotating surface.

The device shown in FIGS. 4 to 6 has a core 1 and an outer jacket 2 arranged coaxially therewith, which enable the formation of pipes from vibro-compacted concrete in a manner known per se. The core 1 has a flat or slightly concave core head 3 with a through hole for receiving and supporting a shaft 4. The shaft 4 rotates the impeller 7 ', on the arms of which blades 9 are attached. The core 1 is preferably provided with an oblique bead 6 on the outer edge of its core head 3. In order to collect the concrete by the vibration of the core 1 in the center of the core head 3, this is slightly recessed. In this construction of the impeller 7 ', the method according to the invention comprises the following steps:

In the starting position, the core 1 with the impeller 7 'is located at the lower end of the mold, the impeller 7' being set in rotation. At the same time, the core 1 is gradually raised so that the concrete, which has meanwhile been poured into the casting mold, is distributed by the impeller 7 ' becomes. In a manner known per se, almost the entire tube is shaped.

Thanks to the special shape of the impeller 7 ', the concrete is also distributed over the rotating surface. As shown in FIG. 4, a sufficient amount of material is obtained in the vicinity of the press ram 11 already in the phase when the latter is still in the upper starting position and the core 1 has not yet reached its maximum height.

According to the invention, the core 1 is stopped shortly before it has reached the highest position and the rotation of the impeller 7 'is stopped, a metered amount of concrete D being fed in even further. As shown in FIG. 4, this metered amount of concrete D accumulates on the core head 3 due to the vibration of the core 1. Then the supply of concrete D is stopped and the ram 11 is lowered to a set height which corresponds to the desired height of the concrete pipe to be produced.

Subsequently or simultaneously, the core 1 is raised to the upper end position and the impeller 7 'is rotated again. The material collected in the center of the impeller 7 'is thus thrown partly into the end region of the tube to be formed and partly onto the inner wall of the guide 12 of the press ram 11. The distribution of the material D collected on the core head 3 of the core 1, whether in the final phase described above or in the normal casting phase, is facilitated by the use of at least one scraper 14 which is attached to one of the arms of the impeller 7 ' .

As shown in Fig. 6, the renewed effect

Rotation of the impeller 7 'under further, more gradually Raising the core 1 so that the accumulated concrete D is distributed on the upper end portion of the concrete tube T and on the inner wall 13 of the ram 11. In this way it is ensured that a sufficient amount of material is supplied to the concrete pipe to be produced, which is compressed to a perfect pipe shape and height with the already supplied concrete under the action of the press ram 11 and the vibrations emanating from the core 1.

The impeller 7 'is stopped as soon as the ram 11 reaches its bottom dead center and the core 1 reaches its top position. To demold the finished tube, the core 1 is moved into its starting position, while the press ram 11 is raised with the outer jacket 2 upwards. In this phase, the concrete previously thrown from the impeller 7 'into the cavity 13 against the wall 12 of the ram 11 is released. The excess concrete falling from the wall 12 is absorbed by the bead 6 and guided by the vibration of the core 1 into the center of the concave core head 3.

As a result, the excess concrete as a whole is collected in the center of the core head 3 and piled up to form a material cone D, so that deposits of concrete residues on the inner pipe wall and any contamination of the machine are avoided. In addition, the collected concrete is reused after the renewed commissioning of the impeller 7 'when casting the next pipe.

The method described above can also be carried out using a differently designed impeller which has a similar construction to the impeller shown in FIGS. 3 to 6, but in which additional blades or outer plates or vanes of special design can be attached, through which an annular receiving space is created on the bead 6.

The method according to the invention described above and the device proposed for carrying it out have already made significant progress with respect to the quality of the concrete pipes produced therewith compared to known concrete pipe casting machines. Problems have arisen, however, in the recovery of the excess concrete with regard to the deposition of

Concrete residues are shown because the concrete tends to adhere to the press ram 11 and to come loose when the core 1 moves downward, so that concrete residues falling down can be deposited on the inner wall of the freshly formed pipe.

These problems are solved by the further development of the method according to the invention described below and the device proposed for carrying it out.

7 and 8 that the press die 11 is firmly connected to a series of struts 30 which rigidly connect it to a head plate 31, on which a connecting plate 32 is preferably fixedly attached. A shaft for an axial movement of the press ram 11 can also be attached to this connecting plate 32. This creates a structure A for receiving and actuating wipers 34 and 35 and for actuating the ram 11.

The wipers 34 and 35 are preferably shaped in the form of a segment of a circle or bent and have at least one upper part which is provided with a reinforcement angle 36, 37. The strippers 34 and 35 are connected to the struts 30 via elastic connecting pieces 33. Brackets 38 are attached to the reinforcement brackets 36 and 37, which, together with brackets 39 and 40 attached in the opposite manner and firmly attached to the underside of the head plate 31, enable the assembly of oil-hydraulic cylinders 41 for each of the two wipers 34 and 35.

As indicated in FIG. 8 by the dashed lines at 34a, the actuation of the hydraulic cylinders 41 leads to the fact that the wipers 34 and 35, which are pivotably attached to the elastic connecting pieces 33, change from a spread position to an approximated position. The structure A also has boundary plates 42 and 43, which are similar to the struts 30, but are arranged radially to the elastic connecting pieces 33 and stops 44 and 45 for limiting the maximum stroke of the wipers 34 actuated by the cylinders 41 and 35.

9 to 11 show that the structure A according to FIGS. 7 and 8 can be built on the upper part of the casting mold shown in FIGS. 4 to 6, with the same ram 11 as previously described , while the upper drive part is built differently. According to the present improvement, the bead 6 of the core 1 can be simplified compared to the previously described embodiment in order to make it easier to push the material together.

The function of the structure A will now be described below.

The structure A is built with the wipers 34 and 35 on the upper part of the outer casing 2 and actuated by means of a conventional shaft, which results in an axial movement and a mutual rotation of the ram 11 enables.

The production of a concrete pipe T now takes place in the course of normal operations until the formation of the upper edge region of the pipe begins, so that the impeller 7 'easily distributes the concrete over the predetermined height.

After these known operations,

Impeller 7 'stopped and the downward stroke of structure A initiated with the ram 11. As shown in FIG. 9, the press ram 11 compresses the concrete during the downward stroke and presses the excess material onto the top of the core 1, where it is deposited. The downward movement of the structure A ends when the position determined for the desired tube height is reached.

After the structure A has been completely lowered, the core 1 is again raised slightly to the level of the press ram 11, so that the casting of the tube T is ended and the excess material is separated from the concrete processed in the manufacture of the tube T. When the core 1 reaches the height of the press ram 11, the impeller 7 'is set in motion again while the core is raised somewhat, so that the excess material which has already accumulated on the edges of the core 1 against the inner walls of the strippers 34 and 35 and against the inner surface of the radial limit plates 42 and 43 is thrown. As shown in FIG. 10, the material which is radially flung out in this way settles on the upper surface of the press ram 11, where it forms a circular crown C.

This is followed by the known operations for demolding the tube T with the lowering of the core 1 and the lifting of the outer jacket 2 in a manner known per se, but with the essential advantage that no excess material falls down, which settles on the inner wall of the tube produced or contaminates the machine.

If the tube T is removed from the mold, the core 1 is in its lowest position. The outer jacket 2 can then be lowered to start pouring the next pipe, while the structure A is left in its raised position to allow the passage of the conveyor belt for the supply of the new concrete material required for the production of the next pipe ¬ lichen. This situation is shown in FIG. 11.

In this position, the hydraulic cylinders 41 are actuated so that the wipers 34 and 35 move towards one another from the starting position. As a result, the excess material C, which has deposited on the upper surface of the press ram 11, is pushed off and passed onto the core head 3, where it is collected for the casting of the next tube.

With the recovery of the excess concrete C and the renewed delivery of fresh concrete, a new work cycle begins for the production of a new concrete pipe T, the core 1 being raised again and the impeller 7 'being set in rotation again.

The one disclosed above. Further development of the method according to the invention and the device proposed for carrying it out has been described with reference to the impeller 7 'according to FIGS. 4 to 6. However, it is also possible for the structure A to be used in conjunction with the impeller 7 shown in FIGS. 1 to 3. The structural design of structure A can of course also be modified. An example is the possibility of mounting a different number of wipers 34 and 35 and limiting plates 42 and 43. It is also possible to provide other actuation systems for the wipers or to combine one or more work steps.

The embodiment of the invention is not limited to the preferred exemplary embodiments specified above. Rather, a number of variants and modifications are conceivable which make use of the solution shown, even in the case of fundamentally different designs.

Reference list

1 core A structure

2 outer jacket C excess concrete 3 core head D metered amount of concrete

4 drive shaft T concrete tube

5 washer

6 bead

7 impeller 7 'impeller

8 rand

9 blades

10 scraper plates

11 ram 12 cylindrical guide / wall

13 cavity

14 wipers 30 struts

31 end plate 32 connecting plate

33 elastic connector

34 wipers

34a swiveled-in scraper

35 wipers 36 reinforcement angle

37 reinforcement angle

38 bracket

39 bracket

40 bracket 41 hydraulic cylinder

42 boundary plate

43 Boundary plate

44 stop

45 stop

Claims

claims

1. Process for the production of concrete pipes of uniform height with a core (1), an outer jacket

(2) and a press ram (11), which form an annular space for forming a concrete pipe (T), characterized in that the concrete is fed into the annular space via an impeller (7, 7 ') arranged on the head side of the core (1) , with which a concrete-free round space is created in the final phase of the pipe production, into which the excess concrete displaced by the press ram (11) at the end of the annular space is collected, in order to then be used against wipers (34, 35) to be flung where it is recovered after the mold has been emptied for a new operation.

2. The method according to claim 1, characterized in that the supply of the concrete is interrupted before the core (1) has reached the position corresponding to a predetermined tube height, and the impeller (7, 7 ') is rotated until the concrete still present on it is distributed in the annular space and the impeller (7) has created on its outer circumference a concrete-free round channel in which the excess concrete displaced by the subsequently lowered press ram (11) is collected.

3. The method according to claim 1, characterized in that the supply of the quantity of concrete (D) required for the production of the concrete tube (T) takes place gradually and continuously on the head (3, 5) of the core (1) and is distributed into the casting mold with an impeller (7, 7 ') and that the concrete supply is interrupted and the upper end of the concrete pipe (T) is is formed, the excess concrete displaced by the press ram (11) being collected on the head side of the core (1) in the round channel created by the impeller (7, 7 ').

4. The method according to claim 1 or 3, characterized gekenn¬ characterized in that the rotation of the impeller (7, 7 ') is interrupted, namely before the core (1) has reached a position corresponding to a predetermined tube height, which is used to produce the upper At the end of the concrete pipe (T), the required amount of concrete (D) is accumulated on a surface (3, 5) by vibrations, the press ram (11) is lowered to the given pipe height and the core (1) is raised to its upper end position.

5. The method according to claim 3, characterized in that the upward stroke of the core (1) and the rotation of the impeller (7 ¹ ) before reaching a predetermined tube height corresponding end position of the core (1) and interrupted in the formation of the upper At the end of the concrete pipe (T), the required amount of concrete (C) accumulated on the head (3, 5) of the core (1) and then with renewed rotation of the impeller (7 ¹ ) and further lifting of the core (1) against the wipers ( 34, 35) is thrown.

6. The method according to any one of the preceding claims, characterized in that the excess concrete (C) is deposited on the press ram (11), from where it is pushed off with at least one stripper (34, 35) and on the head side of the core (1) is directed.

7. Device for carrying out the method

Claim 1, characterized in that the wing ' wheel (7, 7 ') for creating a space for receiving the excess concrete on the outer circumference is provided with at least one scraper plate (10) and / or a blade (9).

8. Apparatus for performing the method according to claim 1, characterized in that the impeller

(7 ¹ ) is provided on its outer circumference with blades (9) which are rotatably arranged around a recess for the accumulation of the amount of concrete (D) required to produce the upper end of the concrete tube (T).

9. The device according to claim 7 or 8, characterized gekenn¬ characterized in that the head side (3) of the core (1) is concave.

10. Apparatus according to claim 7 or 8, characterized gekenn¬ characterized in that the core (1) has a diameter-reduced core head (3), which extends beyond a circumferential outer edge (8) of the impeller (7 '), at the min ¬ at least a scraper plate (10) to create a concrete-free round gutter above an annular disc (5) of the core (1) is attached.

11. The device according to claim 8, characterized in that the impeller (7 ') is provided in the region of the recess with a scraper (14).

12. Device according to one of claims 7 to 11, characterized in that the press ram (11) is provided with at least one scraper (34, 35) with the excess concrete which has been deposited on the press ram (11) the top of the core (1) can be pushed off.

13. The apparatus according to claim 12, characterized in that the scraper (34,35) pivotally connected to a structure (A) of the press ram (11) and is pivotable via a hydraulic cylinder (41) or a similar mechanism.

14. The apparatus of claim 12 or 13, characterized gekenn¬ characterized in that the press ram (11) is connected to at least one limiting plate (42,43) which has a stop (44,45) which the pivoting movement of the scraper ( 34.35) limited.