EP0034745A1 - Control slide valve for viscous matter pumps - Google Patents

Abstract

The invention relates to a control spool (1) for thick matter pumps which, in a flat housing divided into halves, has a control spool (1) which can be moved back and forth with at least one slide rod (11) for the alternate opening and closing of one each penetrating the housing and of the thick matter has flow channel (3,4) and is designed for the purpose of full wear protection, which is not only easy to install in the housing, but can also be removed from it when it is used up and is to be replaced with a free wear protection that the slide plate (10) and the slide rod (11) in a surrounding and with lining rings (39, 40) for the housing channels (3,4) provided closure shell (9) are movable, which consist of several, each from one side the slide rod (11) can be assembled onto hollow bodies (7, 8) that can be threaded and into a recess (37) in the inner sides (33) of the housing halves (5, 6) fo can be inserted with a positive fit.

Description

The invention relates to a control slide for thick matter pumps, which in a flat housing divided into halves has a control slide movable back and forth with at least one slide rod for the alternate opening and closing of each channel passing through the housing and through which the thick matter flows.

The invention relates in particular to the pumping of thick materials which contain abrasive and possibly also fine-grained solids. Therefore suitable The invention particularly applies to concrete pumps because concrete contains sharp-edged aggregates and cement slurry, which also sets under water. With its flat housing, the control slide valve according to the invention can be installed, for example, in a pipe switch between the flanges of a downpipe and a feed or discharge pipe. However, it is preferably installed on concrete pumps between the bottom of a prefilling container and the discharge pipes of a two-cylinder piston pump and / or the delivery line and the discharge pipes.

High demands must be placed on such control spools, because their proper work may not only be used to convey thick matter. Decisive over considerable heights and distances with correspondingly high pressures, but also the quality of the pumped thick matter depends on it, for example when conveying concrete. On the one hand, therefore, the highly stressed parts of the slide must be protected against wear from the sharp-edged components of the thick material, on the other hand, a good seal, in particular against the leakage of the fine components, e.g. the cement slurry demands, the loss of which deteriorates the quality of the concrete.

The control slide described at the beginning is already known (DBP 19 05 706). The seal to the outside is provided by a stuffing box, which surrounds pipes that are drawn onto the two ends of the slide rod and move with it during the back and forth movement of the control slide in the parting plane of the housing in front of the openings of the two channels arranged side by side.

Experience has shown, however, that wear occurs between all moving and immovable parts of the spool valve because fine-grained solids are forced into the gaps that are necessarily between moving and stationary structural parts, where they have a rubbing effect on the parts and harden gradually; if parts of hydraulic cement are involved, the hardening may cause the housing halves to can no longer be separated.

One of the problems with wear is tried to solve by inserting and attaching wear plates in the housing on particularly highly stressed housing parts. These wear plates are solid bodies made of appropriate metal alloys, which consist of a relatively tough and wear-resistant steel. The success that can be achieved with this is of course limited to the relevant parts of the housing and therefore does not offer full wear protection. Replacing the wear surface means loosening the fastenings, e.g. Screws, welds, advance.

Attempts have also been made to solve the problem of wear by designing the valve housing in composite casting. However, such housings are very complicated and involve corresponding casting difficulties. Slider housings, which are protected with a highly wear-resistant surface on the entire area through which the thick material flows, cannot be produced economically according to this proposal.

The invention has for its object to provide a full wear protection in the above sense, which is not only easy to install in the housing, but can also be removed from it when it is used up and should be replaced with a fresh wear protection.

According to the invention, this object is achieved in that the slide plate and the slide rod are movable in a surrounding them and provided with lining rings for the housing channels wear shell, which can be assembled from several hollow bodies that can be threaded onto the slide rod from one side and into a recess on the inside the housing halves can be positively inserted. According to a preferred embodiment of the invention it is provided that the boundary edges running perpendicular to the flat sides of the wear shell provided with the lining rings have roof-shaped bevels which are assigned corresponding inclined surfaces on the boundary edges of the housing recess receiving the wear shell.

The design of the wear protection in the form of the described, insertable into the housing halves, which is assembled from several hollow bodies beforehand over the flat slide and the slide rod, completely removes the housing from the action of the thick material and the moving parts. An alloy containing chromium and vanadium is particularly suitable as the material for the wear shell to be cast, which is adjusted to a certain extent to reduce the risk of breakage.

The preferred embodiment of the invention also leads to the fact that the thick materials penetrating into the gaps between moving parts and stationary parts meet wear-resistant material on the stationary parts that make up the shell. The tough metal alloys mentioned at the beginning, from which the wear shell can be cast, are particularly suitable for this purpose. The assembly of such a shell requires only clean surfaces, on which the positive connection occurs, which holds the wear shell against the moving parts of the control slide during operation. Dismantling is easy because when the housing halves are lifted off the wear shell, the beveled surfaces lead to corresponding force components in the surface levels, which apply shear forces to the bonds, which are immediately released as a result.

Preferably, the control slide according to the invention is simplified in that the wear shell is divided into identical hollow bodies. For this purpose, the wear shell is divided into equal halves along a parting plane perpendicular to the parting plane of the housing, which form a structural unit with the lining rings. Such an embodiment creates the possibility of realizing the wear shell with a relatively simple casting.

For this reason, it also makes sense to divide the control valve housing, which receives the wear shell, into equal halves. For this reason, according to another embodiment of the invention, the recess in the housing receiving the wear shell is formed half in one of the two congruent housing halves. On the other hand, it is of course advisable to reduce the size of the wear shell to what is absolutely necessary. In one embodiment of the invention, this is achieved in that the wear shell, which is rectangular in the housing plane, has guide tubes for a slide rod arranged on at least one of its long sides and with its hollow bodies and on the other long side has a guide link for the edge plate of the slide plate, which is in one piece with the hollow bodies, and that the narrow sides of the wear shell between the end faces of the guides are curved in accordance with the lining rings. This also results in a shape for the wear shell, which has surfaces which have a locking effect in all directions and therefore improves the positive locking.

• Fig. 1 in Draufsicht ein geöffnetes Schiebergehäuse gemäß der Erfindung,
• Fig. 2 ein geschlossenes Schiebergehäuse im Schnitt längs der Linie II-II der Fig. l,
• Fig. 3 das Zusammenbauen der Verschleißschale über der Schieberplatte in einer ersten Phase und in perspektivischer Darstellung,
• Fig. 4 in der Fig. 3 entsprechender Darstellung eine weitere Phase beim Zusammenbauen des Verschleißschutzes,
• Fig. 5 in den Fig. 3 und 4 entsprechender Darstellung die fertig zusammengebaute Verschleißschale,
• Fig. 6 in ebenfalls perspektivischer Darstellung das Einlegen der Teile in das geöffnete Gehäuse und
• Fig. 7 in der Fig. 6 entsprechender Darstellung das geschlossene Gehäuse nach Fertigmontage.

The details, further features and other advantages of the invention result from the following description of an embodiment with reference to the figures in the drawing; show it

• 1 is a top view of an open valve housing according to the invention,
• 2 is a closed valve housing in section along the line II-II of Fig. L,
• 3 the assembly of the wear shell over the slide plate in a first phase and in perspective,
• 4, in a representation corresponding to FIG. 3, a further phase when assembling the wear protection,
• 5 in FIGS. 3 and 4 corresponding representation of the fully assembled wear shell,
• Fig. 6 is also a perspective view of the insertion of the parts in the open housing and
• Fig. 7 in the Fig. 6 corresponding representation of the closed housing after assembly.

The housing shown in Figs. 1 and 2 is schematic compared to the representations in Figs. 3 to 7, i.e. reproduced in a simplified line. This illustration is intended to show the basic structure of the control slide valve according to the invention, which is designated by 1. The flat valve housing 2 then has two juxtaposed, made of a thick material, e.g. Channels 3, 4 through which concrete flows and, as can be seen in FIG. 2, are assembled from two identical halves 5 and 6, respectively. On the inside, both halves have a recess for receiving the wear shell 9, which in turn is divided into two equal halves 7, 8. The wear shell encloses the flat slide plate shown in dash-dotted lines at 10 in FIG are. i.e. run in the housing. Since the wear shell 9 is inserted in a form-fitting manner in a closed recess 12 of the housing 2, the housing has corresponding recesses at 14 and 15, through which the slide rod 11 is guided to the outside. These recesses are lined with wear sleeves 16 and 17, respectively.

As can be seen from FIG. 2, the wear shell 9 has roof-shaped attachments on its outer edges Inclined surfaces 18 and 19, which cooperate with correspondingly beveled surfaces 20 and 21 of the housing.

These inclined surfaces are installed wherever no curved surfaces of the housing or the wear shell are required. In the exemplary embodiment, this is only the case in the region of the tubular guide parts 22, 23 of the wear shell 9 which are provided for the slide rod 11. These parts have rounded outer edges, as can be seen at 25 in FIG. 2.

It is also not absolutely necessary to attach the inclined surfaces 18, 19 or 20, 21 over an edge that affects the entire surface, because the detaching effect when separating the housing halves can already be sufficient if the inclined surfaces are only arranged on the outside on the edges in question .

3 to 7, the details of the control slide can be seen more clearly.

6 and 7, the housing halves 5, 6 have a plurality of bores 30 which can be aligned with one another and receive fastening screws 31 which hold the two housing halves 5 and 6 together. The two housing halves 5 and 6 are the same cast parts, and the wear shell also consists of two identical hollow bodies 7, 8.

For assembly, one half 34, 35 of a recess 37 is provided on the inside 33 of each housing half 5, 6, which receives the wear shell 9. The recess is designed so that the wear shell with a flat middle part 38 let the lining rings 39, 40 protrude from the plane of its outer surfaces for the channels 3, 4 provided in the housing halves 5, 6. The pipe guides 22, 23 at 41 and a guide link 42 at 43 are also fitted.

As shown in FIG. 3, a guide bar 44 runs in the guide link 42, which is formed in one piece on the slide plate 10 and which has a fastening bar 45 on the opposite side with which it is connected to the slide rod 11.

According to the exemplary embodiment, the wear shell 9, e.g. Fig. 1 reveals, along a perpendicular to the division plane of the housing dividing plane 46 divided into equal halves, which are realized with the two hollow bodies 7, 8. Each hollow body forms a structural unit with the lining rings 39, 40 and the parts of the link 42 or the guide tubes 23 assigned to it. As a result of the position of the parting plane 46 described, a narrow side of the wear shell 9 is formed on each half 7, 8. On this narrow side 47 are the faces 48, 49 of the guide tubes 22, 23 or the guide 42 which are offset according to the exemplary embodiment. In between there is a curvature 50 which corresponds to the curvature of the lining rings 39, 40.

As can be seen in FIG. 3, the hollow body 7 is first threaded onto the guide rod 11 from the left. It can then be pushed so far to the right until the guide bar 44 or the subsequent curvature of the slide plate 10 for contact with the corresponding inner sides of the Hollow body 40 come. In a corresponding manner, the hollow body 8 is pushed onto the rod 11 from the right as shown in FIG. 4 until both hollow bodies touch at the parting plane 46, which is shown in FIG. 5.

The parts assembled in this way are, according to FIG. 6, from above into the lower housing half 6, i.e. inserted into the half 35 of the recess located there after the wear bushings 16, 17 described at the outset have been threaded onto the ends of the slide rod 11. Then the upper housing half 5 can be closed so that the screws 31 can be inserted and tightened.

The housing can be positively attached between flanges due to the peripheral recesses 53-56 provided on its circumference.

The slide rod 11 cooperates on both sides with a piston which runs in cylinders pressurized with oil, which are used as a drive for the slide plate.

Claims (6)

1.Control spool for thick matter pumps, which in a flat housing divided into halves has a control spool which can be reciprocated with at least one spool for alternately opening and closing one of the passages passing through the housing and through which the thick matter flows, characterized in that the slide plate ( 10) and the slide rod (1) are movable in a wear shell (9) enclosing them and provided with a lining groove (39, 40) for the housing channels (3, 4). The wear shell consists of several, each from one side onto the slide rod (11 ) threadable hollow bodies (7, 8) can be assembled and inserted into a recess (37) of the inner sides (33) of the housing halves (5, 6) in a form-fitting manner. 2. Control spool according to claim 1, characterized in that the outer edges of the lining rings (39, 40) and the perpendicular to the with the lining rings (39, 40) provided flat sides (38) of the wear shell (9) extending boundary edges roof-shaped slopes (18 , 19), to which corresponding inclined surfaces (20, 21) on the boundary edges of the housing recess (37) receiving the wear shell (9) are assigned. 3. Control slide according to claim 1 or 2, characterized in that the wear shell (9) along a perpendicular to the parting plane of the housing dividing plane (46) is divided into equal halves which form a structural unit with the lining rings (39, 40). 4. Control slide according to one of claims 1 to 3, characterized in that the wear shell (9) receiving recess (37) is each half in one of the two congruent housing halves (5, 6). 5. Control spool according to one of claims 1 to 4, characterized in that the rectangular wear shell (9) arranged in the housing plane on at least one of its long sides, with its hollow bodies (7, 8), integral guide tubes (22, 23) for the The slide rod (11) or on the other long side has a guide bar (42) for the edge (44) of the slide plate (10), which is in one piece with the hollow bodies (7, 8), and that the narrow sides of the wear shell (9) between the end faces ( 48, 49) of the guides (22, 23; 42) are curved in accordance with the lining rings (39, 40). 6. Control slide according to one of claims 1 to 5, characterized in that the end faces (48, 49) of the guides are offset from one another.

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