DE20100892U1 - Mixing screw of a feed mixer with cutting knives - Google Patents

Description

B. Strautmann & Sons
GmbH & Co.
49196 Bad Laer

Mixing auger of a feed mixer equipped with cutting knives

The invention relates to a mixing screw of a feed mixer equipped with cutting blades according to the preamble of claim 1.

Such mixing augers fitted with cutting blades are well known in mobile feed mixers which are equipped with at least one vertical mixing auger. However, in these known designs, the power required for the mixing work, especially with long-fibered, tough shark and leaf material and when breaking up highly compacted large bales, can be relatively high, since depending on the blade position and the design of the blade edge, stalks or leaves, such as corn cobs, often wrap around the blade edge in a hairpin shape and thus prevent the cutting work. The cutting blades fitted with accumulations of feed generate high resistance forces during the mixing process and delay the mixing process considerably.

According to patent application DE 19829867, a design is known for mixers with an adjustable loading box in which controlled drivers on the edges of the mixing screw can be designed as cutting blades. The very complex, expensive design only shows a limited cutting effect in a partial area, since the driving effect is due to a compulsory mechanical control.

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Another design is known from the European patent application EP0880890, which provides for the power requirement for mixing, partly by changing the drive range and partly by controllable cutting blades, whereby the cutting blades can only be adjusted all at once via a manually operated control valve.

The present invention has set itself the task of avoiding an unnecessary increase in the power requirement and the extension of the mixing time, as they arise due to the hairpin-shaped feed accumulations in front of the cutting blades, by means of simple measures on the individual cutting blades in such a way that the feed accumulations are stripped off by pivoting the cutting blades and the cutting blades then pivot automatically back to their starting position, i.e. each individual cutting blade is automatically controlled by the feed accumulations that form.

The invention is described below by way of examples and illustrated in the drawings.

Fig. 1 shows the side view of a feed mixer with a mixing auger.

Fig. 2 shows the perspective view of a mixing screw with
different designs of the cutting blades.

The mixing auger 4) is arranged vertically in the mixing chamber 3) of a feed mixer 1) shown as a trailer vehicle and is driven by the power take-off shaft of a towing vehicle (not shown) via the power connection by means of a cardan shaft 2).

The feed types to be mixed are fed into the mixing chamber 3) from above.

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The feed introduced is caught and chopped by the mixing screw 4), consisting of the central tube 5) and the screw spiral 6) tapering from bottom to top, and the cutting blades 7) - 9) arranged on it. During the mixing process, the feed falls down the side walls of the mixing chamber 3) and is guided back up again by the screw spiral 6). The cutting blades 7) - 9) cut up long-fibered material, which speeds up the mixing process and improves the homogenization of the feed. Wedges 19) that can be gradually swiveled into the mixing chamber 3) can be adjusted as required to influence the mixing process.

The cutting knives 7) - 9) work free-standing without counter-blades. To ensure that feed that accumulates in a hairpin shape around a knife edge 11) does not hinder the cutting work, which leads to an increase in the power requirement, a pivot point 12) is provided on the cutting knife 7), around which it pivots from the cutting position A) to a position B) as feed begins to accumulate in front of the knife edge 11) by the increasing pressure on the cutting knife 7) against the resistance of a leaf spring 13). The feed accumulation is now stripped off at a flatter cutting angle. The leaf spring 13) then pivots the cutting knife 7) back to its original cutting position A).

In a further embodiment, a cutting knife 8) is shown, which is also arranged so as to be pivotable about a pivot point 1.2) and to which a pressure cylinder 15) engages, which is equipped with a pressure reservoir 14) with a set preload pressure as a response threshold. If a cutting resistance is reached on the cutting knife 8) due to accumulations of feed in front of the knife edge 11) that correspond to the level of the preload pressure, the cutting knife 8) pivots back, the accumulation of feed slides off, then the pressure medium previously delivered by the pressure cylinder 15) to the pressure reservoir 14) is returned to the pressure cylinder 15), the cutting knife 8) then returns to its initial cutting position.

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Where feed of the same or similar composition is continuously mixed, the cutting blades 9) can be permanently adapted to the feed conditions and firmly mounted without automatic resetting, whereby they are received and screwed to the auger spiral 6) with a hole pattern 20) formed from at least two beams 21) and 22), optionally on a beam 21) or 22).

The holes on the beams 21) and 22) can be connected by elongated holes 23). In this case, a continuous adjustment is possible, whereby an adjustment of the cutting blades 9) due to the working pressure can be avoided by an adjustment device 24), e.g. by a screw with a lock nut.

Instead of the hole pattern arrangement in the screw spiral 6), it is possible to transfer the hole pattern arrangement accordingly to the cutting blades 9).

After the mixing process is completed, the slide valve 25) is opened and the feed is discharged through the hatch 26) onto a conveyor belt 27), which deposits the feed in the feed aisle.

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Claims (11)

1. Mixing screw of a feed mixer equipped with cutting knives, which is arranged vertically in a mixing chamber and which is equipped with cutting knives on the outer diameter of its screw spiral which tapers conically from bottom to top, characterized in that the cutting knives 7 )-9) are each arranged so as to be pivotable about a pivot point 12 ) and are individually adjustable. 2. Mixing screw equipped with cutting knives according to claim 1, characterized in that the cutting knives 7 ) and 8) are held in their set position by a restoring force or are automatically returned to this position. 3. Mixing screw equipped with cutting knives according to claims 1 and 2, characterized in that the restoring force is generated by a leaf spring ( 13 ). 4. Mixing screw equipped with cutting knives according to claims 1-3, characterized in that the restoring force is generated by one or more spiral leg or shaped springs. 5. Mixing screw equipped with cutting knives according to claims 1-4, characterized in that the restoring force is generated by a pressure medium accumulator (14 ). 6. Mixing screw equipped with cutting knives according to claim 1, characterized in that the cutting knives 9 ) are arranged optionally on a beam 21 ) or 22 ) of a V-shaped hole pattern 20 ). 7. Mixing screw equipped with cutting knives according to claims 1 and the like, characterized in that the cutting knives 9 ) pivot about a pivot point 12 and are continuously adjustable within the elongated holes 23 ) in the screw spirals 6 ). 8. Mixing screw equipped with cutting knives according to claims 1, 6 and 7, characterized in that the cutting knives 9 ) can be fixed by means of an adjusting device 24 ). 9. Mixing screw equipped with cutting knives according to claims 1, 6, 7 and 8, characterized in that the V-shaped hole pattern ( 20 ) is arranged on the cutting knife. 10. Mixing screw equipped with cutting knives according to claims 1, 6, 7, 8 and 9, characterized in that a V-shaped hole pattern is present on both the screw and the cutting knife. 11. Mixing screw equipped with cutting knives according to claims 1, 2 and 5, characterized in that the pressure medium reservoir (14 ) is arranged within the central tube (5 ).