EP1725770A1

EP1725770A1 - Viscous matter piston pump

Info

Publication number: EP1725770A1
Application number: EP05715556A
Authority: EP
Inventors: Manfred Lenhart
Original assignee: Friedrich Wilhelm Schwing GmbH
Current assignee: Friedrich Wilhelm Schwing GmbH
Priority date: 2004-02-26
Filing date: 2005-02-25
Publication date: 2006-11-29
Also published as: CN1946936A; KR20060133593A; RU2006132458A; CA2557146A1; BRPI0507901A; WO2005083267A1; US8123504B2; DE102004009363A1; AU2005217734B2; JP4950874B2; JP2007524038A; CN100523495C; CA2557146C; AU2005217734A1; ES2273621T1; DE102004009363B4; KR100865565B1; RU2350781C2; US20080038131A1

Abstract

The invention relates to a multi-cylinder viscous matter piston pump (1), for transporting in particular concrete. Said pump comprises at least two transport cylinders (3, 5), which transport the viscous matter from a pre-filled container (7) into a transport conduit and a changeover valve (9) for the alternate connection of the transport cylinder to the transport conduit. Said valve comprises at least two rotatable valve bodies that have a respective conduit section (15L, 17L) between one of the respective transport cylinders and the transport conduit and that are connected downstream of the transport cylinder to a collecting tube (19). The inventive changeover valve (9) comprises at least, preferably two substantially rotational rotary valves (15, 17; 15', 17'; 15', 17'), each of which comprises a straight conduit section (15L, 17L) for connecting the associated transport cylinder (3, 5) to the transport conduit and at least one section that blocks said connection. The invention also relates to a method for operating said viscous matter pump in a continuous transport mode.

Description

PISTON DICK FUEL PUMP

The present invention relates to a thick matter pump with the features of the preamble of claim 1. In a broader sense, it also relates to the control of such thick matter pumps.

Piston thick matter pumps have been used for a long time, in particular to convey concrete on construction sites. As a rule, they are designed as hydraulically operated piston pumps, usually two-cylinder, which convey the concrete through hoses or pipes. In the following, we will always speak of concrete conveyance in simplified form. However, the invention is not limited to the use in concrete feed pumps, but can be used for all similar thick matter pumps.

Such pumps have to feed a single delivery line with two alternately filled cylinders and associated pistons. Each filled cylinder is connected to the delivery line via a switchable roller switch. The piston then pushes the concrete out (pump stroke) while the parallel piston is moved back to refill the cylinder with concrete (suction stroke). At the end of each stroke, the direction of movement of the cylinder pistons is reversed and the pipe switch changed, so that pump and suction strokes alternate constantly. The two pump pistons are preferably driven hydraulically and coupled to one another, so that they basically work in opposite directions.

Common pipe switches (DE 29 33 128 C2) are arranged so that they can be set back and forth between two switching end positions, in which they alternately establish the connection between the cylinder openings and the delivery line on the one hand and on the other hand the standard filling container. This results in discontinuous funding.

US 3,063,129 describes a concrete pump with continuous delivery, in which the changeover valve or its diverter consists of a so-called rock slide valve. His Waist opening is connected downstream as an outlet, but is pivotally connected to the mouth of the delivery line. Its kidney-shaped hem opening (inlet, upstream) is long enough to cover the openings of both delivery cylinders at the same time. During operation, the pipe switch executes a continuously oscillating swiveling movement, the axis of which is coaxial with the mouth of the delivery line. The swivel angle of the pipe switch is approximately 50 ° on both sides of a central position.

The pistons of the delivery cylinders are controlled in interaction with the current position of the pipe switch so that at the moment the two cylinder openings are covered by the hem opening, one cylinder is at the end and the other at the beginning of a pump stroke. The funding moves smoothly from one cylinder to the other. In the known control, the same time period is used for the suction stroke and the pump stroke of each piston. There is consequently no simultaneous delivery of both cylinders.

As a result of the only one-sided mounting of this known pipe switch on the side of the delivery line and the support and sealing surfaces essentially circumscribing only the hem opening, the significant acting tilting moments cannot be fully absorbed by the known construction. It cannot be ruled out that considerable leakage losses then occur in the sealing area between the hem opening of the pipe switch and the delivery cylinders due to gap formation, which in turn jeopardize the realization of an actually continuous delivery.

The British patent 1,063,020 describes as a generic state-of-the-art a multi-cylinder thick matter and concrete pump, the change-over valve in one embodiment of which comprises two rotary slide valves, each of which can be controlled by its own lifting cylinder (also in the form of a rock slide valve). Their outlet openings are connected to a common downpipe, which in turn is connected downstream to the delivery line. Each rotary valve can work with either a single or two pump cylinders. A synchronized control of the rotary slide valve is addressed, but with this known pump and control, continuous delivery of the delivery cylinders into the common delivery line is neither intended nor possible. It is also known to equip thick matter pumps of the type in question with an insertion station, with the aid of which a cleaning body for removing unused thick matter remaining in the delivery line can be introduced. This insertion station includes, for example, a motor / hydraulically movable chamber slide with at least two chambers of the same cross section. In the idle state of the loading station, one chamber forms a section of the delivery line, while the other chamber is freely accessible. In the latter, the said cleaning body can be inserted manually from the outside. For a cleaning process, the loading station is switched to a working position when the thick matter pump is shut down, in which the chamber containing the cleaning body now replaces the other chamber within the delivery line. Sodami can be pressed through the delivery line using compressed air, pushing the remaining thick material in front of it. However, these known insertion stations must be provided in addition to the changeover valve discussed above.

The invention is based on the object of specifying an improved thick matter pump and a method for controlling a thick matter pump with a continuous flow.

This object is achieved according to the invention with regard to the thick matter pump with the features of patent claim 1, with regard to the control method with the features of the independent claim 23.

The features of the dependent claims subordinate to the independent claims indicate advantageous developments of the invention.

While in the pumps according to the US and GB patents set out above, the rock-shaped rotary slide valves are arranged essentially exposed in the thick matter collecting container and have to be driven with a certain eccentricity around their axis of rotation through the thick matter mass in the normal filling container, with the Implementation of the changeover valve with two essentially smooth-walled cylindrical (preferably drum-shaped) rotary valves, an arrangement which is significantly less exposed to the resistance of the thick material, in particular the concrete, for the preferred application. will create. This applies on the one hand to the abrasive stress, but also to the stress caused by the dynamic pressure in the delivery line or the delivery cylinders.

In the area of the rotary valve, the thick material is not deflected under pressure, as is the case with the known rocker valve, but essentially only guided straight through pipe sections. The concrete flows from the delivery cylinders are only brought together in the collecting pipe (also downpipe). This contributes significantly to the pressure relief of the actual slide and has a reducing effect not only on the bearing forces, but also on the frictional forces when the rotary valve is switched over. Consequently, this design solution also achieves a noticeable reduction in the mechanical wear on the movable and fixed components of the changeover valve.

It should be noted that although a two-cylinder thick matter pump is dealt with as the preferred application, the design according to the invention can also be readily transferred to pumps with three or more cylinders, a rotary slide valve generally being associated with each delivery cylinder.

To equip the changeover valve (guide structure and rotary slide valve) with slide guides, with friction and abrasion-resistant materials and, if necessary, with wearing parts, it will be possible to use means known per se, so that there is no need to go into this here. The same applies to the seals between the rotary valves and the openings of the delivery cylinder and the collector pipe.

According to the invention, it is advantageous if the rotary slide valves can assume three different positions, namely a line position, a block position and an inlet position. These three positions correspond to a structure or a subdivision of the rotary valve into three different sections, namely a line section, a block section and an inlet section. The names of the sections or positions speak for themselves and are discussed in connection with the description of the attached figures.

Deviating from the three-way division mentioned above, other variants are also possible. So z. B. a block position on both sides between the line position and the inlet position ing are provided, which results in a division of the rotary slide valve over its circumference by appropriate sections.

In a further variant, the aforementioned three-way division can be doubled by providing two inlet positions and two line positions and two block positions or the corresponding section for each rotary slide valve. In this latter variant, z. B. the following sequence: inlet section - block section - line section - inlet section - block section - line section.

h In all variants, the sections are preferably arranged evenly distributed over the circumference of the rotary slide valve, with angles of 120 ° for the triple division, those of 90 ° for the quadruple division and those of 60 ° for the six-division. Continuous rotary operation of the rotary valves is particularly suitable for the latter two variants.

It is advantageously possible to design / prefabricate the sections mentioned as individual modules and to assemble them in the required arrangement. Overall, a control box or control frame with the required valve paths or functions is created. Possibly. This design favors the simple replacement of individual, prematurely worn or damaged modules or sections, especially if you provide detachable connections between them.

It goes without saying that the two rotary valves are expediently constructed identically to one another or at least in mirror image; However, deviations can arise due to the installation space in the linkages of the respective drives.

A very significant advantage of the solution according to the invention is the option, which is relatively easy to implement, of using at least one, if not both, rotary slide valves of the changeover valve as an insertion station (s) for cleaning bodies. The short line sections of the rotary valve and the delivery line must be cleaned during breaks in operation of the pump, ie residues of thick matter or concrete remaining in it must be removed. In an advantageous further development, the invention provides access to the rotary valves. This can e.g. B. by means of flaps that are normally closed, but open said access after opening.

For this purpose, a separate cleaning or insertion position of the rotary valve or valves can be provided. According to an advantageous further development, however, the inlet position of the rotary slide valve is also used as an insertion position for cleaning bodies. This is possible because in this inlet position the cross-section of the rotary valve has no function and is also depressurized.

With the prior art discussed at the outset, such a combination is neither provided nor readily possible.

The rotary vane can be operated oscillating or rotating (rotating). Hydraulic actuating cylinders are preferably used as drives for the rotary slide valves, which pivot or rotate the rotary slide valve around their axes of rotation using connecting rods and / or cranks. A possible embodiment is discussed in the generic prior art GB-PS 1 063 020. However, other suitable rotary actuators, e.g. B. electric motors, rack drives etc. are used. Provided that the flow paths of the rotary valves are not affected, a belt or belt drive can also be considered. For this purpose, the rotary valve is covered on a (possibly stepped) part of its circumference by a band (flat, wedge, toothed, multi-V belt), which on the other hand is guided via a drive shaft. For such belt drives, of course, each rotary valve can also be equipped with a pulley specially arranged on its axle shaft.

Further details and advantages of the subject matter of the invention will become apparent from the drawing of an exemplary embodiment and its detailed description that follows below.

They show in a highly simplified and purely schematic representation Figure 1 is a perspective view of the ensemble of the thick matter pump along with secondary components. Figure 2 is a frontal view in partial section of a double rotary slide switch valve according to the invention. 3 is a view of a section through the central axis of the feed cylinder of the thick matter pump according to FIG. 2 (line BB) to illustrate the arrangement of the feed cylinder, the changeover valve and the collecting pipe; 4 shows a sectional side view of the changeover valve in a position suitable for inserting a cleaning body; 5 shows a path-time diagram of the phase-shifted strokes of both pistons of the thick matter pump over the respectively assigned positions of the two rotary valves, FIG. 6 shows a first embodiment variant of the rotary valve of the changeover valve, FIG. 7 shows a second embodiment variant of the rotary valve.

1 shows a perspective view of an outline of a thick matter pump 1 with two delivery cylinders 3 and 5 lying next to one another in parallel, a funnel-shaped prefilling container 7 open at the top and a changeover valve designated overall by 9. The latter is arranged in a housing or a guide structure 11 on the bottom of the prefilling container 7. Near the bottom of the trough-like guide structure 11, a maintenance flap 13, only indicated here and always closed in the normal state, can be provided on the side facing the conveying cylinders 3 and 5, the function of which is still to be discussed.

The pistons belonging to the delivery cylinders 3 and 5 are not shown. Both pistons are driven independently of one another (preferably hydraulically) and can basically assume any relative positions and speeds as part of their strokes and their control. However, it is also possible to operate them hydraulically coupled. Both cylinders and pistons have the same diameter, e.g. B. 250 mm.

The guide structure contains two drum-shaped rotary valves 15 and 17, which form the valve body of the changeover valve 9. The rotary slide valve 15 is assigned to the feed cylinder 3, the rotary slide valve 17 belongs to the feed cylinder 5. Only via the changeover valve 9 or the valve paths of the rotary slide valve get thick material into the delivery cylinders 3 and 5, and only via this switch valve do these delivery cylinders eject the thick material into the delivery line, not shown here, as will be described in detail later. Finally, a collecting or downpipe 19 with a flange 21 is provided downstream of the changeover valve 9 for connecting the delivery line. The collecting pipe 19 and the beginning of the delivery line are advantageously at the same height as the axis of the delivery cylinders 3 and 5.

The guide structure 11 is flanged to the open ends of both (lying) delivery cylinders 3 and 5. The thick material to be conveyed by the thick matter pump gets into its interior from above from the prefilling container 7, preferably only into the space of the “gusset” between the two rotary valves 15 and 17. This gusset forms an extension of the funnel of the prefilling container 7 downwards, and the thick matter only gets to where it is finally also sucked into the cylinders. The design provides that both rotary valves each have an inlet channel that can be fed from this gusset (FIGS. 2, 3).

The openings of both delivery cylinders 3 and 5 each open out within the wall surfaces of the guide structure 11 covered by the drum-shaped rotary slides 15 and 17, respectively, in the lower region on both sides of the aforementioned gusset. As a result, when the thick matter is sucked into the feed cylinder, the greatest possible fill level of thick matter remains above the cylinder openings.

The guide structure 11 could indeed be designed as an open, in particular frame-like or frame-like scaffold. However, it is preferably constructed as an essentially closed box with a plurality of function-related openings. In its upper area in particular, it is kept so wide open that an undisturbed inflow of the thick matter is also guaranteed directly at the bottom of the prefilling container to the changeover valve. In addition to the upper opening, an open side towards the conveyor cylinders will also be necessary.

Fig. 2 is used for a more detailed discussion of the design of the changeover valve 9 and its rotary slide valve 15 and 17. The feed cylinders 3 and 5 are concealed here in the longitudinal direction behind the guide structure 11. The lower part of the prefilling container 7 is here again indicated by dashed lines. It can be seen that it leads like a funnel into the above-mentioned upper gusset formed by the lateral surfaces of the rotary valves. At the bottom of the gusset, a partition 11T of the guide structure 11 can be seen, which ends between the two rotary valves at the point where they are closest to one another. It would also be conceivable (not shown) to pull the partition 11T higher between the rotary valves 15 and 17, e.g. B. up to the upper edge of the guide structure 11 in order to divide the thick material flows intended for the feed cylinders early.

Both rotary valves 15 and 17 can be positioned within the guide structure 11 about axes of rotation 15A and 17A in three different predefined switching positions. They are mounted on both sides (on the side of the delivery cylinder and on the side of the collector tube), so that the mobility of the rotary valve is always ensured, even with high external forces. This is done with the help of a drive system to be discussed later, in oscillating (swivel) mode or in rotary (rotary) mode. You have to convey the connection between the prefilling container 7 and the delivery cylinders 3 and 5 on the one hand and the delivery cylinders and the manifold 19 together with the delivery line connected to them on the other. For this purpose, they include three different functional sections, each of which follows one another on pitch circles 15T / 17T about the axes of rotation offset by 120 ° and are designed identically for both rotary valves. Therefore, they are described together below.

An inlet section 15E / 17E is intended to guide thick matter from the prefilling container 7 into the respectively assigned delivery cylinder 3. It is therefore open upwards (in the radial direction) to the prefilling container and laterally (parallel to the axis of rotation) to the feed cylinder. In its functional position (inlet position), it lies exactly between the openings of the respective delivery cylinder and the manifold. Therefore, their surface sides facing away from the conveying cylinders, that is to say toward the collecting tube 19, are expediently closed by sealing surfaces. Consequently, in the inlet position of a rotary slide valve there is no connection to the collecting tube or this remains closed with respect to the prefilling container 7. As will become clearer later, this enables a conveying operation of the other conveying cylinder during the refilling of the one conveying cylinder in the sense of continuous conveyance. In order to deflect the thick matter by 90 ° from the radial inlet from the prefilling container into the axial outlet to the respective feed cylinder, the inlet sections are preferably provided with a chute, that is to say a spherically curved channel section; one could also provide a correspondingly angled knee tube, possibly with a funnel-shaped radial inlet, and integrate it into the structure of the rotary valve. The free cross section of the inlet section preferably corresponds approximately to the cross section of the delivery cylinder and preferably forms an (deflection) angle of 90 °.

Offset 120 ° clockwise along the pitch circle 15T / 17T, the inlet section 15E is followed by a blocking or block section 15B / 17B. It only has the task of shutting off the connection between the respective delivery cylinder and the manifold 19 on both sides, and is therefore without any flow leading function.

A line section 15L / 17L follows, offset by a further 120 ° along the pitch circle 15T / 17T, which very preferably comprises a short, in particular straight pipe section which is open on both sides and has the same clear cross section (250 mm diameter) as the delivery cylinder. This coordination of the shape and size of the line section 15L can be seen well in FIG. 2 as in FIG. 3 (left). It is constantly filled with thick matter during operation of the changeover valve and the thick matter pump.

As already mentioned above, the sections mentioned can be viewed as individual modules that can be prefabricated and assembled to form a rotary valve. Overall, the rotary slide valves 15 and 17 each form a 3/3-way valve with their part of the guide structure 11, with the inlet chutes, the openings of the delivery cylinders and the openings of the collecting pipe as paths and with the three positions described above.

In the position of the switching valve 9 shown in FIG. 2, the inlet section 17E of the rotary slide valve 17 is in its active position which is open to the gusset space (the feed cylinder 5 is refilled with new thick material), while the line section 15L of the rotary slide valve 15 is at the same time the connection between the feed cylinder 3 and the Collecting tube 19 forms so that the feed cylinder 3 can eject thick matter. In FIG. 5, which will be discussed later, this corresponds to phase 7 of the movement phases of the changeover valve. The exactly reversed functional position of the changeover valve is shown in phase 3 of FIG. 5.

If a block section 15B / 17B lies in front of the opening of the respective delivery cylinder, then the delivery cylinder on the one hand and the collecting tube on the other hand are closed by this. After filling with thick matter, the affected delivery cylinder can thus travel a short pre-compression stroke in order to adapt the drain in the freshly filled thick matter to the drain in the delivery line connected to the collecting pipe. At the same time, the sealing surface towards the collecting pipe 19 in turn prevents an effect on the drain in the delivery line.

The sectional view of FIG. 3 clearly shows on the right the geometrical coordination of the inlet section 17E together with the channel 17S of the rotary slide valve 17 on the delivery cylinder 5, as well as the position of the sealing surface 17D in front of the opening of the sealing pipe 19. from the radial outside) only flow into the opening of the feed cylinder 5 (axially) via the channel 17S; the same applies to the corresponding inlet position of the rotary valve 15.

On the left in Fig. 3 you can clearly see the correspondence of the cross sections of the feed cylinder 3 and the line section 15L of the rotary valve 15. The exercise structure 11 is in turn provided with openings HZ on the cylinder side and towards the header pipe 19 with openings HS, each having the same cross section as the feed cylinder or have the line sections.

You can also see the basic drum shape of the rotary valve 15 and 17 here. B. be made as round boxes from flat material, insert pieces such as pipe and channel sections etc. In particular, one can see here the arrangement of cutting rings known per se from conventional rock slide valves on both sides of the line section 15L and on the cylinder-side opening of the inlet section 17E. Furthermore, the two block sections 15B and 17B are sealed sealing plates which, like the cutting rings, are pressed onto the inner walls of the guide structure with the aid of elastic rings or the like and slide on them when the rotary valve is pivoted. In this way, they support the reliable function of the changeover valve 9. The cutting rings surround the openings 11Z or 1 IS of the guide structure in the inlet or line position of the respective rotary valve, the sealing plates close them off in the block position. The inner walls of the guide structure 11 will have to be equipped with appropriate wear plates, as are well known per se from the prior art.

It is conceivable to provide a common sealing plate for the block section and the inlet section on the surface side of the rotary slide valves 15 and 17 facing the collecting pipe 19, which sealing plate could then extend along the pitch circle with an approximately kidney shape along an angle of approximately 150 °.

It is not absolutely necessary to make the walls of the guide structure 11 completely closed, especially since the rotary valves 15 and 17 are securely mounted on their axes of rotation 15A and 17A. However, for safety reasons (penetration of foreign bodies, prevention of unintentional reaching into the vehicle and similar accident risks), it may be advantageous to keep them closed. In particular, in the lower positions of the inlet sections 15E and 17E (which were at least partially filled with thick material after the last suction process), thick material cannot be prevented from getting into the lower troughs of the guide structure. It may therefore make sense to perforate the bottom of the guide structure (ie the two tub parts, which are clearly visible in FIG. 2 and adjoin the partition 11T downwards) and / or to provide them with drain flaps so that, for. B. can drain through gaps between the rotary valve and the guide structure penetrating water. Possibly. it is even possible to provide an emptying opening through which the thick matter can automatically fall out of the inlet sections under the influence of gravity.

In addition, it may be expedient to provide sealing strips on the outer radial surface of the rotary valve on the two radial outer edges of each inlet section, said sealing strips extending in the axial direction of the rotary valve and sliding on the inner walls of the guide structure. as soon as the inlet section reaches a non-active position. This could largely prevent the thick material in the inlet section from being smeared on said walls and ultimately blocking the rotation of the rotary valve.

The diameter of the rotary valve is about 800 mm in this illustration, i.e. slightly more than three times the inside diameter of the delivery cylinder. This dimension can be reduced if necessary if the partial circles 15T and 17T can be designed with smaller diameters with the same functionality of the valve body. The thickness or depth of the rotary valve (dimension seen in the longitudinal direction of the delivery cylinder) can of course be adapted to the installation conditions according to the respective requirements. In order to offer the largest possible inlet cross-section for the chutes, however, it should not be smaller than the cross-section of the delivery cylinder itself and will therefore be around 300 mm. The depth of the guide structure - without pipe connections and drive parts - thus reaches around 350 mm, with a height of around 850 mm and a width of around 1650 mm.

This sectional view also shows the shape and the technical function of the collecting tube 19 even better. It is designed in a manner known per se as a downpipe, the two legs of which are connected directly to a rotary slide valve 15 or 17 and the "collar" or output flange 21 of the latter The free cross-section of the downpipe is smaller in the collar area (approx. 180 mm diameter) than in the mouth area to the rotary valves.

The overall design of the changeover valve 9 is very compact due to the chosen design of the immediately adjacent rotary valve. As can also be seen in FIG. 2, the sections 15L and 17E relevant for the flows when filling and ejecting the delivery cylinders are almost at the same height in their respective functional positions with the axes of rotation 15A and 17A, that is to say they move laterally above on both sides of the partition 11T only insignificantly from their closest possible proximity. The lateral distances between the feed cylinders 3 and 5 and the overall width of the collecting tube 19 thus remain sufficiently small. Fig. 4 shows of the Dickstoffφumpe 1 only in this view of the lying delivery cylinder 3 in the region of its open (discharge) end. The second feed cylinder 5 is hidden behind the feed cylinder 3 in the direction of view. The flap 13 mentioned above can be seen here, once in the closed position (drawn through) and once in the open (dash-dotted) position. The line section 15L of the rotary valve 15 is in its lowest position at the level of the flap 13. It should be noted in this connection that such a valve 13 can be provided for each rotary valve 15 and 17, but due to the close proximity of both rotary valves in the guide structure a common maintenance and emptying flap could also be provided for both rotary valves 15 and 17. It would then of course have to be sufficiently wide to allow unimpeded intervention (in particular the insertion of cleaning bodies) in both rotary valves (or in their line section).

Since the respective line section is completely separated from the delivery line in this position, there is no increased drain in it. In normal operation, this flap (s) will not be subjected to any pressure load, so that they do not have to be designed to be particularly strong and also do not have to be sealed particularly well. Apart from this, suitable measures will ensure that the flap 13 cannot be opened when the thick matter pump and the changeover valve are running in the conveying mode, and that the changeover valve cannot be adjusted while the flap is open.

After opening the flap or flaps 13, thick material still located in the line sections 15L / 17L can easily be removed. In normal operation of the changeover valve, this is of course not necessary, since this relatively small amount or column of thick matter is expelled again to the collecting pipe and the conveying line during the next delivery or discharge stroke of the respective delivery cylinder.

After opening the flap 13, a cleaning body 23 (also indicated by dash-dotted lines in FIG. 4) can in any case be inserted into the line section 15L or 17L (previously emptied by hand). After the flap 13 has been closed, it can be brought into the line section by switching the rotary valve between the openings of the respective delivery cylinder or the collecting tube 19. Then he is z. B. with compressed air, which is supplied via a supply, not shown here, between the feed cylinder and the rotary valve, through the manifold 19 and the feed line to free these lines from the remaining thick matter.

Passing a cleaning body through both branches of the collecting or downpipe 19 also clears both of them, whereby the thoroughness of cleaning the delivery line may be increased by double running through a cleaning body (successively through both branches of the collecting tube and then through the common delivery line) can. It goes without saying that the same cleaning body 23 can be used twice in succession or different cleaning bodies can be used for both processes.

By suitable shaping of the collecting pipe 19 in the gusset area and / or by simultaneous supply of drain in its two branches, it can be ensured that the cleaning body does not get caught in the collecting pipe branch which has already been cleared during a second pass.

5, a path-time diagram of the delivery pistons along with the phases of movement of the rotary valves 15 and 17 of the changeover valve 9, the actual delivery process and the control of the increase material and its changeover valve are now shown and detailed after introduction of all essential components of the thick matter pump and its periphery discussed. The two pistons of the delivery cylinders 3 and 5 are represented here only as reference symbols K3 and K5 at the beginning of the respective diagram line. The movement sequence or cycle of the piston K3 is dashed, that of the piston K5 is drawn solid.

Said movement phases of the changeover valve, the reduced schematic representation of which corresponds to the view of FIG. 2, are numbered from 1 to 8 and plotted side by side in the diagram over a time axis and separated from one another by vertical lines. The functional sections of the rotary valve are again provided with the associated reference numerals. In phase 1, both rotary valves 15 and 17 are in their “passage position”, ie their line sections 15L and 17L are simultaneously in front of the openings of the delivery cylinders 3 and 5 (hereinafter also the starting position). Both delivery cylinders 3 and 5 are therefore simultaneously with the collecting pipe 19 and the connected delivery line. None of the delivery cylinders communicates with the prefilling container 7.

According to phase 1 of the diagram, the piston K3 of the delivery cylinder 3 moves to the end of a pumping stroke, while the piston K5 of the (freshly filled) cylinder 5 is just beginning its new pumping stroke after precompression. Both pistons are moved parallel and in the same direction at a relatively low speed. This can be referred to as a "constant phase".

Phase 2 is a transition of the delivery cylinder 3 between the pump stroke and the suction stroke. The rotary valve 15 was pivoted — preferably after the piston K3 had stopped — by 120 ° in a clockwise direction, while the rotary valve 17 remained stationary. The opening of the delivery cylinder 3 is now tightly closed by the block section 15B, its piston K3 is briefly at rest before the change in its stroke direction. The delivery cylinder 3 is completely closed off from the collecting pipe 19. This intermediate or block position of the rotary valve 15 safely avoids any fluidic short circuit between the one pumping and the other suction suction cylinder.

In this phase, which is relatively short in time, the rotary slide valve 15 can move continuously; if necessary, it can be slowed down or stopped briefly if the sealing surfaces of the block section 15B are short. However, this phase is preferably completed quickly.

In the meantime, the piston K5 is still in the pump stroke, as can also be seen in the diagram phase 2. The incline of its movement is now steeper, ie its feed rate is increased to a normal dimension (e.g. doubled) compared to the previous constant phase 1. This ensures a constant flow of thick matter in the delivery line compared to phase 1. In phase 3, the rotary valve 15 was now swiveled clockwise by a further 120 °. He is now in his inlet position; its inlet section 15E lies in front of the opening of the delivery cylinder 3. At the same time, the rotary slide valve 17 is still in its “line position”, which still allows delivery from the delivery cylinder 5 into the delivery line.

The diagram shows in phase 3 that the piston K5 continues to run at full speed or at full pump power, while the piston K3 executes a suction stroke, preferably with a gentle start and stop, but overall at a higher speed than in the pump stroke (“suction phase As a result of the regularly occurring (weight) pressure of the thick matter in the prefilling container and its aerodynamic guidance on the chute 15S, the delivery cylinder 3 is optimally filled.

In this phase too, a temporary stopping of the oscillating or rotating movement of the rotary slide valve 15 can be advantageous, so that the entire suction stroke can take place when the delivery cylinder 3 is fully open.

The position of the changeover valve 9 in phase 4 of FIG. 4 corresponds to phase 2. The rotary slide valve 15 has now been pivoted back from the inlet position by 120 ° counterclockwise. Now, as can be seen from the diagram, the piston K3 of the delivery cylinder 3 (closed again by the block section 15B of the rotary valve 15) can pre-compress the thick material just sucked in at low speed over a very short stroke, preferably to the operating pressure prevailing in the delivery line (" Pre-compression phase "). This is recommended in view of gases sucked in with the thick matter (air bubbles) and the counterpressure present from the collecting pipe 19 and the delivery line in order to avoid impacts in the system if the cylinder opening in the subsequent phase from the line section 15L The rotary slide valve 15 can also be briefly stopped or in any case braked here.

The K5 piston is in the final stages of its pumping stroke, still at full speed. With regard to the position of the change-over valve 7, phase 5 corresponds exactly to phase 1 (starting position, "same phase"). The rotary valve 15 has been pivoted backwards by a further 120 °. The phase 5 also shows that the pistons K3 and K5 are now visible with reversed roles (related to phase 1) start their phase-shifted play anew with a simultaneous pump delivery at reduced speed. The cycle of movement of the rotary valve 17 now begins.

Phase 6 is a mirror image of phase 2; Now the piston K3 alone pumps at full speed, while the block section 17B of the rotary slide valve 17 tightly closes the delivery cylinder 5 after it has been pivoted through 120 ° and its piston K5 is at rest according to diagram phase 6.

Phase 7 corresponds to phase 3 as a mirror image. As already mentioned above, FIG. 2 also shows this phase. The rotary valve 17 is pivoted clockwise by a further 120 °. The feed cylinder 5 is refilled. Its piston K5 runs back to its starting position according to diagram phase 7, and thick material flows into the feed cylinder 5 via the inlet section 17E. At the same time, the delivery cylinder 3 is at full pump capacity, its piston K5 at full feed speed.

With phase 8 corresponding to phase 4, piston K5 compresses the newly filled thick matter again after pivoting rotary valve 17 counterclockwise by 120 °, while piston K3 enters the final phase of its pumping stroke. In the diagram, a full operating cycle of the two-cylinder thick matter pump has now been completed, the rest of the process begins again with phase 1.

To clarify the speeds, pressures and forces that occur during operation of the thick matter pump with continuous delivery, it should be mentioned that the entire sequence of phases 1 to 8 takes place within only 6 seconds, as indicated by the labeled time axis below the diagram. The pistons of the feed cylinder have to go through strokes of approx. 1 m in length, while the total strokes of the rotary valves are in a range of around 500 to 600 mm. For further interpretation of the diagram in FIG. 5, it should first be repeated that in phases 1 and 5 both pistons simultaneously pump thick matter into the collecting pipe 19 and into the delivery line. During these phases, their speeds are matched to one another in such a way that their total delivery corresponds to that of a piston only at its normal feed speed. This, together with the pre-compression phase of the newly starting piston, achieves a practically bumpless constant delivery rate of the thick matter pump.

In all other phases, only one of the pistons is in pumping mode and it then preferably runs at a constant speed. The static drain in the branch of the collecting pipe 19 which is in each case then inactive corresponds to the pressure in the delivery line. It is securely intercepted by the sealing surfaces 15D and 17D of the rotary valve located in the block and / or inlet position.

The design of the changeover valve according to the invention and a targeted feed control of the delivery pistons make it possible, in the phases of the common pumping strokes, to achieve an output of the thick matter pump that is constant compared to the individual pumping power of a piston, and thus to practically eliminate the pulsation of the thick matter flow in the delivery line. This benefits in particular the precompression of the thick matter in phases 4 and 8, by which it is avoided that when the freshly filled feed cylinder 3 or 5 is opened, a drakless “buffer space” is connected to the feed line 13. The volume of each in the the “activated” line section 15L or 17L of thick material is certainly negligible with regard to such a buffer effect.

Although the precompression steps (phases 4 and 8) exert considerable forces on the rotary valves 15 and 17, these are, however, safely absorbed and removed by their robust yet relatively simple pivot bearing within the guide structure 11. Here again the advantage of the permanent connection of the downstream end of the collecting pipe 19 to the delivery line comes into play. The instantaneous positions of the pistons K3 and K5 and the rotary slide valve 15 and 17 can be recorded with suitable sensors (position transducers, position switches, drain sensors etc.), if necessary directly on the respective drives. These sensors feed their position signals to a preferably central control unit of the thick matter pump, which in turn controls the drives of the delivery pistons K3 and K5 and the changeover valve 9.

In particular, it controls a reduction of their feed speeds in the moments of simultaneous conveying of both conveying cylinders. It is not absolutely necessary to control both pistons at half the speed, but in principle one piston could also be used, for B. control to 1/3 of full speed and the other to 2/3 of full speed (provided the same diameter and total strokes). The goal remains a constant flow of the thick matter in the delivery line.

Furthermore, during the period in which the freshly filled delivery cylinder is closed by the block section of the assigned rotary slide valve 15 or 17, the control unit has to stop the changeover valve temporarily or to switch to slow running, on the one hand, and to control the precompression stroke of the associated piston on the other hand. This may also require a drain sensor, which can be arranged in the cylinder, in the piston, or also in the branch of the manifold 19 loaded with the drain. A blocking of the rotary valve 15 and 17 by excessive pressure during the pre-compression can of course be safely excluded by means of pressure limiters or the like.

Also in other phases, e.g. B. the same phase, the transition phase and the inlet or suction phase, a slow running of the rotary valve 15/17 or a temporary standstill can also be advantageous between the reversal points. Overall, one will have to carefully weigh the downtimes and shifting times of the rotary valves so that on the one hand the available flow cross-sections are not reduced too much by overlapping the block sections with the openings of the feed cylinders, and on the other hand no excessive pushing speeds are necessary. In the interest of speedy operation of the pump, however, it is preferable to minimize downtimes of the rotary valves as far as possible or to avoid them altogether. In principle, it is also possible to control a rotating operation instead of the oscillating operation of the rotary valves 15 and 17 shown in FIG. 5 with reversing phases. For the transition between the line position and the inlet position, it is not absolutely necessary to maintain a separate block position, since the inlet sections with the sealing plates 15D and 17D are also able (as already mentioned earlier) to meet the requirements of the delivery line intercept acting Drack. This results in the option of continuing to turn the rotary valve directly from the line position to the inlet position, instead of going through the block position first.

6 and 7 each show variants of the design of the rotary slide valve of the changeover valve 9, which, however, are also basically divided into sections with three different functions. Components having the same function have the same reference numerals as in FIGS. 1 to 5. While in FIG. 6 two rotary valves 15 'and 17' are each designed with six sections, the rotary valves 15 "and 17" of FIG. 7 each have four. Regardless of this, these types of switch valve can basically be connected to the same thick matter pump as the type previously discussed. In both FIGS. 6 and 7, the feed cylinders 3 and 5 are indicated by their reference numerals in the area on both sides of the upper gusset between the rotary slide valves.

The rotary valves 15 'and 17' of FIG. 6 each have two inlet sections 15E and 17E, two pipe sections 15L and 17L and two block sections 15B and 17B; for the sake of clarity, these are not all provided with reference numerals, since the assignments result directly from the pairwise identical representation. Overall, this results in an angular division of 60 ° for the control of the changeover valve 9, that is to say exactly half of the rotary valves 15 and 17 from the previous example.

In contrast, according to FIG. 7, the rotary slide valves 15 "and 17" have an angular division of 90 ° between the individual sections, two block sections 15B and 17B lying diametrically opposite one another and a line section along the pitch circle 15L / 17L and an inlet portion 15E / 17E between them. Overall, this results in an angular division of 90 ° for the control of the changeover valve 9.

These rotary valves 15 ', 17' or 15 ", 17" can be used to implement both a circulation control and an oscillating control, in which case the flowchart in FIG. 5 can be transferred with corresponding modifications. Basically, the operation of the thick matter pump equipped therewith does not change compared to the version with only three functional sections, but with an increase in the number of sections shorter switching paths and thus a further improved continuous conveying operation of the thick matter pump can be achieved.

The four-part rotary valve 15 "and 17" with its double block sections enable continuous rotation. It can be seen that in each case when turning further through 90 °, one of the paired block sections 15B / 17B always follows the line section 15L / 17L or the inlet section 15E / 17E.

Claims

Expectations:

1. Multi-cylinder thick matter pump (1) for conveying in particular concrete, the at least two conveying cylinders (3, 5) convey the thick matter from a prefilling container (7) into a conveying line and a changeover valve (9) for alternately connecting the conveying cylinders to the conveying line is assigned, which comprises at least two rotatable valve bodies (15, 17; 15 ', 17'; 15 ", 17"), each of which comprises a line section (15L, 17L) between each of the delivery cylinders and the delivery line and downstream of the delivery cylinder a manifold (19) are connected, characterized in that the changeover valve (9) comprises at least, but preferably two, substantially rotatably movable rotary valves (15, 17; 15 ', 17'; 15 ", 17"), each of which is used for Connecting the respective delivery cylinder (3, 5) assigned to it with the delivery line provided straight line section (15L, 17L) and at least one section blocking the connection.

2. Dickstofφumpe according spoke 1, characterized in that the switching valve (9) comprises a guide structure provided with openings for passage of thick matter flows (11) for the rotary valve (15, 17; 15 ', 17'; 15 ", 17").

3. Dickstofφumpe according spoke 2, characterized in that the filling structure (11) is firmly connected to the prefilling container (7) so that the rotary valve (15, 17; 15 ', 17'; 15 ", 17") or their inlet openings are always in contact with the filled thick matter.

4. Dickstoffφumpe according spoke 2 or 3, characterized in that the guide structure (11) is substantially box-shaped or frame-like and for each rotary valve (15, 17; 15 ', 17'; 15 ", 17") a fixed, in particular axle bearing (15A, 17A) on both sides.

5. Dickstoffφumpe according to any one of the preceding claims, characterized in that the rotary valve (15, 17; 15 ', 17'; 15 ", 17") within the guide structure (11) by pivoting about an axis of rotation (15A, 17A) in each case at least two different positions can be positioned, namely a line position in which the Can eject the delivery cylinder into the collecting tube (19) and a blocking or inlet position in which the delivery cylinder can suck in thick matter from the prefilling container (7).

6. Dickstofφumpe according to any one of the preceding claims, characterized in that the rotary slide valve (15, 17; 15 ', 17'; 15 ", 17") are constructed identically or in mirror image to each other.

7. Dickstofφumpe according spoke 5 or 6, characterized in that the rotary valve (15, 17; 15 ', 17'; 15 ", 17") are drum-shaped and are rotatably mounted on both sides in their guide structure (11).

8. Dickstoffφumpe according to any one of the preceding claims, characterized in that a rotary valve (15, 17; 15 ', 17'; 15 ", 17") is divided along its circumference into at least three sections, one of which is the line section (15L, 17L ) and another of which is an inlet section (15E, 17E).

9. Dickstoffφumpe according to claim 8, characterized in that the inlet section (15E, 17E) comprises a radially directed with respect to the axis of rotation (15A, 17A) of the rotary valve open inlet and an outlet parallel to the said axis of rotation to the feed cylinder.

10. Dickstoffφumpe according spoke 8 or 9, characterized in that a deflection device (15S, 17S) is provided in the inlet section (15E, 17E) of the rotary valve.

11. Dickstoffφumpe according to claim 8 or 9 or 10, characterized in that between the line from section and the inlet section, a block section (15B, 17B) is provided without a flow function.

12. Dickstofφumpe according to any one of claims 8 to 11, characterized in that the sections of the rotary valve are arranged on a common pitch circle (15T, 17T) with uniformly offset distances.

13. Dickstofφumpe according to any one of claims 8 to 12, characterized in that the sections of the rotary valve (15, 17; 15 ', 17'; 15 ", 17") are designed as individual modules and in particular are releasably connected together.

14. Dickstoffφumpe according to any one of claims 8 to 13, characterized in that the rotary slide valve (15 ', 17') are divided into six sections, including two pipe sections (15L, 17L), two inlet sections (15E, 17E) and two block sections ( 15B, 17B).

15. Dickstoffφumpe according to any one of claims 8 to 13, characterized in that the rotary valve (15 ", 17") are divided into four sections, including a line section (15L, 17L), an inlet section (15E, 17E) and two block sections ( 15B, 17B).

16. Dickstoffφumpe according to any one of the preceding claims, characterized in that it at least one for removing thick material from the line section (15L, 17L) of a rotary valve (15, 17; 15 ', 17'; 15 ", 17") provided flap ( 13) includes.

17. Dickstoffφumpe according spoke 16, characterized in that a common flap for several rotary valves (15, 17; 15 ', 17'; 15 ", 17") is provided.

18. Dickstofφumpe according to any one of the preceding claims, characterized in that the rotary slide valve (15, 17; 15 ', 17'; 15 ", 17") can be driven and positioned independently of one another, in particular with the aid of hydraulic lifting cylinders.

19. Dickstofφumpe according spoke 18, characterized in that the drive for the rotary valve comprises a acting on the axis of rotation of the rotary valve and driven by a lifting cylinder crank mechanism.

20. Dickstoffφumpe according spoke 18, characterized in that a wrap around the axis of rotation of a rotary valve (15, 17; 15 ', 17'; 15 ", 17") is provided.

21. Dickstoffφumpe according to any one of the preceding claims, characterized gekemizeich in that the line section (15L, 17L) of the rotary valve (15, 17; 15 ', 17'; 15 ", 17") comprises a cylindrical tube with the same diameter as the delivery cylinder.

22. Dickstoffφumpe according to any one of the preceding claims, characterized in that it comprises a control unit, which of position transmitters, the current positions of the changeover valve and the rotary valve and the delivery piston of the delivery cylinder are supplied and which drives the rotary valve and the delivery piston cyclically control according to a predetermined travel-time sequence.

23. A method of operating a thick matter pump, in particular a thick matter pump (1) according to the preceding claims, for continuous conveyance, which thick matter pump has at least two open-sided delivery cylinders (3, 5) with delivery pistons (K3, K5) and a changeover valve (9) with independent Rotatable slide valves (15, 17; 15 ', 17'; 15 ", 17"), which can be controlled in relation to one another to the movement of the delivery pistons, each have at least one line section (15L, 17L) for connecting an assigned delivery cylinder to a delivery line and an inlet section ( 15E, 17E) for sucking in thick matter from a prefilling container (7) through the assigned delivery cylinder (3, 5), a cyclical phase of the delivery piston (K3, K5) being cyclically controlled, during which at least two rotary valves (15, 17; 15 ', 17'; 15 ", 17") are in a line position, in which their line sections (15L, 17L) the assigned delivery cylinders at the same time Connect the continuous ejection of thick matter to the delivery line.

24. The method according spoke 23, according to which the delivery pistons (K3, K5) are controlled in the synchronized phase so that they are coordinated in such a way that the amount of thick matter pumped by them is at least approximately the same as when conveyed by a piston (K5 or K3) alone during the suction stroke of the other piston (K3 or K5).

25. The method according to spoke 23 or 24, in which, at the beginning of the pumping stroke of each delivery piston (K3, K5) of each delivery cylinder (3, 5), the opening of which is temporarily closed by means of a block section (15B, 17B) of the rotary slide valve and this piston a precompression stroke performs.

26. The method according spoke 25, characterized in that each pump stroke of a piston at least one pre-compression phase (phases 4/8), a first uniform phase (phases 1/5), a pump phase (phases 2 to 4/6 to 8) and a second Gleichlauφhase (phase 5/1) includes.

27. The method according to any one of the preceding method claims, characterized in that during the same phase both feed pistons (K3, K5) are driven at the same speed, in particular at half the normal speed of their further pumping stroke.

28. The method according to any one of the preceding method claims, characterized in that a pumping phase is followed by a transition phase (phase 2/6) with one delivery piston at a standstill during the continuous pumping stroke of the other delivery piston.

29. The method according to any one of the preceding method claims, characterized in that the suction stroke of each piston (phase 3/7) runs faster than its pump stroke, in particular between a transition phase (phase 2/6) and a pre-compression phase (phase 4/8) is included ,

30. The method according spoke 29, characterized in that each suction stroke of a piston comprises a start-up and a run-down ramp at a reduced speed.

31. The method according to any one of the preceding method claims, characterized in that the rotary slide valves (15, 17; 15 ', 17'; 15 ", 17") are slowed down or temporarily stopped in the same phase.

32. Method according to one of the preceding method claims, characterized in that the rotary slide valves (15, 17; 15 ', 17'; 15 ", 17") are slowed down or temporarily stopped in a pre-compression phase.

33. Method according to one of the preceding method claims, characterized in that the rotary slide valves (15, 17; 15 ', 17'; 15 ", 17") are slowed down or temporarily stopped in a transition phase.

34. Method according to one of the preceding method claims, characterized in that the rotary slide valves (15, 17; 15 ', 17'; 15 ", 17") are slowed down or temporarily stopped in a suction phase.

35. Method according to one of the preceding method claims, characterized in that the rotary slide valve (15, 17; 15 ', 17'; 15 ", 17") during breaks in operation of the thick material be positioned in an operating position that allows the removal of remaining thick matter and, if necessary, the insertion of a cleaning body.

36. The method according spoke 35, characterized in that the operating position is the inlet position of the rotary valve.

37. Wrong according to spoke 35 or 36, characterized in that a safety device for preventing a start of the rotary valve is activated during the removal and / or insertion process.