DE3902000A1 - Broadcaster - Google Patents

Abstract

A broadcaster for pourable spreading material, especially fertiliser, consists of a supply container with at least one adjustable outflow orifice and with an outflow shaft which adjoins the latter and out of which the spreading material emerges in a jet-like manner in a falling stream, and of a centrifugal disc which rotates thereunder about an axis arranged offset to the outflow and which has at least one throwing blade which extends over the entire radial extension of the spreading-material jet relative to the circumference of the centrifugal disc and which forms, in cross-section, a U-profile fastened with its lower leg to the centrifugal disc. To reduce uncontrolled rebound losses, provision is made for the outflow shaft and/or the upper leg of the throwing blade to be designed and arranged in such a way that the particles reflected as a result of rebound effects during the penetration of the throwing blade into the spreading-material jet are deflected into the throwing blade or captured by the latter and accelerated outwards.

Description

The invention relates to a centrifugal broadcaster capable spreading material, in particular fertilizer, consisting of a Storage container with at least one adjustable spout opening and an adjoining outlet shaft which the spreading material exits in a jet stream, and one underneath about an axis offset to the outlet running centrifugal disc with at least one spreader vane, which extends over the entire radial extent of the spreading material jet extends to the circumference of the centrifugal disc and in cross section forms a U-profile with its lower leg on the Centrifugal disc is attached.

As with all types of spreader, you are also with a slingshot spread carefully, one over the spread, if possible even distribution of the spreading material, i.e. an over to achieve a constant spreading density. This The target is most likely with relatively small spreading quantities and / or small spread. The scatter pattern then shows one  flat-triangular course, the maximum (peak) in the In the middle behind the spreader lies flat on both sides falls off. The actual working width of the spreader is that width at which 50% of the desired spread rate have been brought. By appropriate connection driving then an overlap of the scatter patterns can be achieved in such a way that the spreading amounts of each trip add up so that over the entire scattered area an almost uniform spreading density is obtained. The greater the spread rate, the more so the spreading pattern increases the steeper the spreading pattern down to the side and the more difficult it is, by way of Such driving overlap of the scatter patterns reach, which leads to an even spreading density. Also there is an increase in the effective working width. Over-fertilization is also found in the middle area, which is primarily due to the so-called impact losses is to be fed. These are those grit particles that are not controlled by the spreader vanes but when the spreader wing enters the fertilizer beam accelerated in any direction by impact processes or be distracted.

With even larger spreading quantities / spreading widths the spreading pattern shows in addition to a strong cant in the middle area behind the Centrifugal spreader, mainly on the aforementioned impact losses can be attributed, one more on each side Cant. Overall, this results in a wavy shape Course of the scatter pattern with a relatively steep slope towards the outside falling flanks. Because with a larger working width also amount of grit to be poured in is referred to here so-called "quantity effect" to differentiate it from before called "impact effect". That arises from the "quantity effect" Irregularity in the spread pattern can be seen when connecting do not eliminate driving.  

In order to reduce the negative effects, in particular the "quantity effect", four spreader vanes are symmetrically arranged on the centrifugal disc instead of two spreader vanes, for example. The - otherwise only slight - improvement in terms of the "quantity effect" usually leads to a deterioration in the effects of the "impact effect". Attempts have also been made to counter the problem with adjustable throwing vanes in order to provide the spreading material with different exit angles depending on the spreading width. With all known measures, there is at most a slight improvement, but not an even approximate elimination of the disadvantageous consequences of the "quantity effect" and the "impact effect".

The invention has for its object in a slingshot spreader of the structure mentioned above, in particular the impact reduce losses and thus a more even spread to achieve picture.

This object is achieved in that the Discharge shaft and / or the upper leg of the spreader vane are designed and arranged such that the one immersing the throwing wing in the spreading material jet by impact effects reflected particles deflected into the spreader vanes or captured by it and accelerated to the outside.

While with the known centrifugal spreaders with two or four Throwing wings caused by uncontrolled reflections when turning on dipping the spreader wing into the scattering material Particles mainly in the middle area behind the Collect spreader and there to a disproportionate cause large scattering density, these particles are caused by the inventive design of the outlet shaft and / or upper leg of the spreader wing and its arrangement and  Assignment to each other so distracted that they turn into the Spreader wings reach or are caught by it, so that these particles through the spreader wing to the outside be accelerated and the throwing flow in a controlled manner leave gel.

The principle of the invention can be used in many ways realize and optimize. According to one embodiment provided that the outlet shaft at least along its The entry side of the spreading wing in the fertilizer jet opposite lying limit with flexible, in the direction of rotation of the throw Wing is evasive strips of material provided in the The trajectory of the throwing wing protrude, the training is preferably made so that the flexible material brush against the boundaries of the downcomer are assigned to them when passing through the throwing wing do not dodge the fertilizer jet into the fertilizer jet. The flexible strips of material are expediently as bristles or bristle bundle made of plastic.

Due to the aforementioned design, when immersing the Throwing wing into the scattering jet on the opposite lying side using the flexible material strips leads and held together. In particular, it is avoided that the scattering material jet during this immersion, as with be Known centrifugal spreaders, burst, that is, one large part of the particles reflected in all directions and - without getting into the spreader wing - uncontrolled splash. The responsible impulse forces between spreader vanes and particles and the particles with each other that are taken up by the flexible material strips and steamed or even eliminated. This ensures that the spreader wing while passing by the outlet Fertilizer jet over its entire cross section and the particles are accelerated outwards. Plastic bristles  are particularly suitable because, on the one hand, they are one have sufficient flexibility to remove the spreader wing soft, on the other hand have a high resilience, to get back into the after passing the throwing wing to align the vertical starting position. They are also today sufficient plastic bristles available wear-resistant. The training according to the invention is also ensures that even with centrifugal discs with four throws wings that are usually featured for larger spreads can be seen that the impact losses do not increase as is usual.

Another preferred embodiment is characterized by this from that the upper leg of the U-profile of each throwing wing at least with its leading edge and in the out Section passing by in parallel in one plane a short distance from the lower edge of the outlet chute is arranged below this, preferably further it is provided that the upper leg of each throwing wing of its leading edge against the direction of rotation Formation of a clearance angle is inclined downwards.

Regardless of the inclination of the spreader vanes relative to the Horizontal ones, especially one for large bedding intended plate-like formation of the centrifugal disc Be sure that the spreader vanes rise outwards is safe asked that the upper leg always immediately below Swipe past half of the lower edge of the drain shaft. Thereby will be the number of particles in the gap between the upper leg and the lower edge of the outlet shaft advised and not accelerated sufficiently, minimized. Due to the still provided clearance angle, under which the upper Leg is employed, it follows that the throwing wing only strikes the fertilizer jet with the leading edge, while the fertilizer emerging behind the leading edge particles fall on the inclined open area and predominantly after  reflected at the rear and towards the centrifugal disc so that they can be gripped by the next spreader wing. Furthermore, the backflow of the fertilizer jet is caused by the clearance angle in the outlet chute, which leads to an uncontrolled change in the Throughput leads, reduced or avoided.

Another advantageous embodiment is characterized by this out that the leading edge of the upper leg of each throw wing at the inner end of the web and in one Forward curvature in a straight line, given to the web if parallel section merges, it is also advantageous is when each spreader wing has its inner end over it Center of the slinger on the other side enough.

This embodiment ensures that the front running edge of the spreading wing when entering the fertilizer beam always hits the fertilizer particles so that they be accelerated to the outside. The exact off formation of the curvature and the extension of the throwing wing its inner end to the respective location and shape of the Aus opening or the outlet shaft are adjusted.

In a further preferred embodiment it is provided that the upper leg of each spreader wing in its outer section, the - seen from the center of the slinger - beyond the Outlet shaft is located higher than the lower edge of the outlet shaft.

While the upper leg in the area of the outlet shaft runs just below its lower edge the leg in the outer section of the spreader wing above the lower edge of the outlet shaft with the result that the - seen from the center of the centrifugal disc - mainly particles ricocheting outwards from the higher one Legs are caught and deflected into the spreading wing,  in order to accelerate to the outside in a controlled manner to become.

The measure that the web of the U- Profiles of each throwing wing in its outer section with his at the transition to the higher leg inner edge on a radius of the centrifugal disc is slightly larger than the one that is radially on furthest outer boundary of the outlet shaft.

The inner edge of the web at the transition to the higher one Leg section therefore runs on the outside directly at the end Passage shaft over, so that there is also the possibility the reflection of particles to the rear is eliminated.

In the aforementioned embodiment, it is useful if the higher leg in the outer section of the litter wing arranged parallel to the bottom of the storage container is. The leg lies in the outer section of the spreader vane so high that such particles are also detected, the uncontrolled outward at a flat angle be inflected.

Another embodiment of the invention stands out by out that the web and the upper leg of each throw wing at its inner end at one in the center of the sluice the disc arranged cylindrical cap abut, is also advantageous if the upper leg on the inner End abuts the cap over the entire length of its edge.

With the aforementioned embodiment, the spreader wing is on its inner end, as it were, closed. This will make it far avoided avoiding that when entering the throwing wing in the Scattering material particles are reflected inwards or  possibly reflected particles captured and the Centrifugal field of the throwing wing are exposed.

Preferably, the training is such that the front running edge of the upper leg at one of the contact points of the bridge on the cap in the extension of the bridge approximately on the opposite side of the cap, in a first Curvature with increasing radial distance from the axis of the The centrifugal disc is pulled forward and with one on it subsequent opposite curvature into an approximately to the web parallel straight line passes, advantageously the first curvature of the leading edge is approximately spiral.

In this way, on the one hand, the width of the upper leg widened in the area near the center of the centrifugal disc, the throwing wing is therefore lower overall, so that more particles can be captured. On the other hand, the Curvature of the leading edge as it enters the Scattering material jet an impulse force on the particles that furthest is directed outwards. This applies in every rotation position of the throwing wing, so that this also gives the possibility of a Reflection of the particles on the leading edge that this ricochets inside, is largely excluded.

By the further measure that the cap is the obvious The lower edge of the outlet shaft protrudes upwards, is white terhin ensures that even between the lower edge of the Outlet shaft and the upper leg particles not after be splashed inside, rather they are from the cap slowed down and at most stand out behind the spreader vanes the slinger. This advantage is still be favors that the radius of the cap is slightly smaller than that Radius, which on the axis of the slinger on the white test the inner limit of the outlet shaft.  

Usually the centrifugal discs are from below driven by a drive shaft, for example is connected to the PTO via a bevel gear. For this purpose, the drive shaft has a hub which is attached to the slinger. According to the invention now the cap for attaching the centrifugal disc to the hub serve.

A further preferred embodiment is characterized by this from that the throwing wing at its outer end, from the upper Outgoing leg, sloping downwards.

While the particles are predominant in small quantities move outwards in the lower part of the spreader vane, climb with larger spreading quantities upwards until the spreading wing is occupied over its entire height. With even larger litter quantities build up within the spreader wing certain layer thickness due to the different Acceleration of the particles in the different layers lead to irregularities in the spread pattern. Due to the Ab leave the bevel moving in the spreading wing Particles the spreader wing earlier than the parts moved below kel. This results in practical tests as shown have an even spread pattern even with large ones Spread. The bevel can only be part of the Extend height or over the entire height, so that the Particles are released on different radii and thus reach different throwing distances.

Finally, according to an expedient embodiment, the outlet shaft can have a cross section to be taken downwards from the outlet opening. Similar to the upper leg of the spreader vane , which is positioned at a clearance angle, this feature primarily serves to prevent the spreading material from backing up in the discharge chute as the spreader vane passes by, thereby avoiding quantity errors in particular.

The invention is based on one in the drawing reproduced embodiment described. In the Show drawing:

Fig. 1 is a schematic partial view of a two disc spreader;

Fig. 2 is a scatter image diagram;

. Fig. 3 is a view similar to Figure 1 of a first embodiment of the invention;

FIG. 4 shows a top view of the centrifugal discs according to FIG. 3;

FIG. 5 shows the cross sectional profile of the spreading blade;

Figure 6 is a plan view of a centrifugal disc, in a further embodiment.

FIG. 7 shows a representation of a further exemplary embodiment similar to FIG. 1;

Fig. 8 is an enlarged partial view of the centrifugal disc shown in Fig. 7 in the right part and

Fig. 9 is a view corresponding to FIG. 1 of a further embodiment.

The fertilizer spreader shown schematically and in sections in FIG. 1 has a funnel-shaped storage container 1 with a bottom 2 , outlet openings 3 arranged therein and adjoining outlet ducts 4 which extend downward ver. A stirrer 5 which loosens the fertilizer and keeps it free-flowing is arranged within the storage container 1 . Below the bottom 2 of the reservoir 1 , a centrifugal disc 6 is arranged under each outlet shaft 4 , the axis of rotation of which is offset to the outside relative to the outlet shaft 4 . Each slinger has at least one, in the embodiment shown two throwing wings 8 , which extend from the center of the slinger to the outside. The centrifugal disks 6 and the stirrer 5 are driven, for example, by the power take-off of a tractor via bevel gearboxes, which are accommodated in the gearbox housing 9 , which is shown schematically.

The centrifugal disks 6 are plate-shaped in the embodiment shown in FIG. 1 with an upwardly rising wall, so that the throwing vanes 8 accordingly run inclined upwards. This training is particularly suitable for large spreading widths in order to achieve favorable ballistics for the fertilizer particles leaving the centrifugal disc 6 .

A typical spread pattern for a certain working width generated by a centrifugal broadcaster according to FIG. 1 is shown in the diagram according to FIG. 2, in which the spread density (weight per area) is plotted over the spread width. Four characteristic scatter patterns for four different scatter quantities a , b , c and d are shown, with a < b < c < d . The ordinate coincides with the longitudinal axis of the tractor or the direction of travel. From Fig. 2 it can be seen that with smaller spreading quantities, the spreading density drops steadily outwards from a maximum behind the tractor. The larger the spread rate, the more pronounced the cant in the tractor axis. From a certain spreading quantity, a spreading pattern is formed, as is shown in FIG. 2 using curve d, the largest spreading quantity. It is no longer a steady curve, rather it has a depression in addition to the central elevation towards the outside and then an elevation at the end, from which the scattering density then drops much more steeply. The curve d applies, for example, to a centrifugal disc with two spreader vanes. If, on the other hand, it has four spreader vanes, then the two side elevations are not or less pronounced, but the middle elevation is much more pronounced.

In the case of small and medium spreading quantities, the off Compensate for thinning in the outer area by the fact that Connection driving ensures an overlap of the scatter patterns is so that there is only one over the entire sprinkled area weakly wavy scatter pattern results. With larger spreading quantities compensation is only possible in the peripheral areas Lich, however, neither the average cant nor the subsequent sinks and also extremely poor compensate for the two side elevations.

While the average elevation arises almost exclusively from the so-called impact effect or from the impact losses, that is to say from those fertilizer particles which are not detected in a controlled manner by the wing 8, but rather on the disc itself and on the spreader vanes 4 running along the outlet shaft 8 are reflected and are mainly deposited in the middle, the two lateral exaggerations are caused by the so-called volume effect and are primarily attributable to fluid flow processes that cannot be influenced in the spreader vane. Even with an increasing working width, the impact losses increase due to the necessarily larger volume throughput, as does the volume effect.

Fig. 3 shows a first embodiment of the invention, in which 4 flexible material strips 10 , for example in the form of plastic bristle bundles, are arranged on the outside of the outlet shaft. They run essentially vertically and protrude into the movement path of the throwing vanes 8 . They are, as Fig. 4 shows, arranged at all limits of the outlet shaft 4 , at which they can dodge wings when immersed in the grit jet so that they can not affect the grit jet. The scattering material beam is thus bordered and guided by the flexible material strips 10 at these limits, in particular the particles cannot be reflected forwards and inwards. On the other hand 10 the flexible strip of material in the direction of rotation, as soon as they are detected by the vanes. 8

The spreader vanes 8 are preferably made of a U-shaped profile, ie, as can be seen in FIG. 5, consist of an approximately perpendicular web 11 , a lower leg 12 , by means of which the spreader vanes 8 are fastened to the centrifugal disc 6 , and one upper leg 13 . The upper's angle 13 is advantageously inclined towards the rear from the leading edge 14 , which first enters the scattering material jet, so that a clearance angle is created.

Fig. 6 shows first in the wing shown on the left with dash-dotted lines 13 ' a spreader wing, which is drawn at its inner end beyond the center of the centrifugal disc to the other side. The leading edge 14 'is attached to the web at the inner end and runs with a curvature 14 ''into the straight-line section which runs approximately parallel to the web.

Fig. 6 also shows with solid lines an optimized embodiment in which a cylindrical cap 15 is arranged in the center of the centrifugal disc 6 . The throwing vanes 8 rest with their inner end on the cylindrical outer surface of the cap 15 . For example, the web 11 of the throwing wing 8 ends with its vertical inner edge 16 on the jacket of the cap 15 , while the upper leg 13 is pulled inward beyond this inner edge 16 . The leading edge of the leg 13 starts approximately at a point 17 on the cap 15 , which is an extension of the web 11 . From there, the leading edge runs outward in a spiral curvature 18 . This is followed by an oppositely directed curvature and finally the leading edge 14 merges into a linear section that terminates on the outside.

The radial distance of the inner boundary of the outlet chute 4 is, as shown in FIG. 7, slightly larger than the radius of the cap 15 . Furthermore, the cap 15 projects above the lower edge of the outlet shaft 4 , so that a complete closure is given in the center. In the Ausführungsbei of FIG game. 7 can also be seen that the upper's angle 13 is deposited in the outer portion of the throwing blade 8. Details of this can be seen in FIG. 8. The leg 13 has in the area outside the outlet shaft 4 an elevated portion 20 , which is in particular higher than the lower edge of the outlet shaft and in the exemplary embodiment shown is arranged in a plane parallel to the bottom 2 . The inner edge 21 of the web 11 formed at the transition lies on a radius that is slightly larger than that of the outer boundary of the outlet shaft 4 . The same design is of course also possible with such slingshots, which are not curved in the manner of plates, but are designed as simple horizontal plates, in which case the upper leg 13 and its outer section 20 lie in parallel planes, which in turn are parallel to the lower one Leg 12 can lie.

Fig. 8 also shows that the throwing wing 8 is chamfered at its outer end from above to the outside, so that the particles accelerated outward in the upper region of the throwing wing 8 let the throwing wing ver earlier or on smaller radii than the moving below Particle.

The centrifugal disc 6 is driven by a drive shaft 23 which is provided with a hub 24 . This can have an external thread onto which the cap 15 can be screwed. In this way, by means of the cap 15, the sluice derscheibe 6 braced on a collar 25 of the hub 24 . To take a driver pin 26 is also angeord net on the collar 25 , which passes through the slinger 6 and engages in a groove on the cap 15 .

Finally, the embodiment of FIG. 9 shows a downcomer 4 , the free cross section of which extends from the outlet opening 3 downward, so that the throughput is not negatively influenced by backflow effects.

Claims (20)

1. Centrifugal spreader for free-flowing spreading material, in particular special fertilizer, consisting of a storage container with at least one adjustable outlet opening and an adjoining outlet shaft, from which the litter emerges in a jet-like manner, and one below it about an axis arranged offset to the outlet around the running centrifugal disc with at least one spreader vane, which extends over the entire radial extent of the scattering jet to the circumference of the centrifugal disc and forms a U-profile in cross section, which is attached to the centrifugal disc with its lower leg, characterized in that the outlet shaft ( 4 ) and / or the upper leg ( 13 ) of the throwing wing ( 8 ) are designed and arranged such that the particles reflected when the throwing wing ( 8 ) is immersed in the scattering material beam by impact effects are deflected into the throwing wing or caught by it and accelerated to the outside . 2. Centrifugal broadcaster according to claim 1, characterized in that the outlet shaft ( 4 ) at least along its entry side of the spreader vane ( 8 ) in the fertilizer jet opposite boundary with flexible, in the direction of rotation of the spreader vane material strip ( 10 ) is provided in protrude into the trajectory of the throwing wing ( 8 ). 3. Centrifugal broadcaster according to claim 1 or 2, characterized in that the flexible material strips ( 10 ) are arranged at those limits of the downcomer ( 4 ) at which they do not evade into the fertilizer jet when passing through the throwing vane ( 8 ) by the fertilizer jet. 4. Centrifugal broadcaster according to one of claims 1 to 3, characterized in that the flexible material strips ( 10 ) are formed as a bristle or bristle bundle made of plastic. 5. Centrifugal broadcaster according to one of claims 1 to 4, characterized in that the upper leg ( 13 ) of the U-profile of each spreader vane ( 8 ) at least with its leading edge ( 14 ) and in the section passing by on the outlet shaft ( 4 ) a level parallel to the lower edge of the outlet shaft with a small amount was arranged below this. 6. Centrifugal broadcaster according to one of claims 1 to 5, characterized in that the upper leg ( 13 ) of each throwing blade ( 8 ) from its leading edge ( 14 ) is inclined ent against the direction of rotation to form a clearance angle downwards. 7. Centrifugal broadcaster according to one of claims 1 to 6, characterized in that the leading edge of the upper leg ( 13 ) of each throwing blade ( 8 ) attaches to the web ( 11 ) at its inner end and in a forward curvature in a straight line, if necessary, parallel section passes to the web. 8. Centrifugal broadcaster according to one of claims 1 to 7, characterized in that each throwing blade ( 8 ) with its inner end over the center of the centrifugal disc ( 6 ) extends to the other side. 9. Centrifugal broadcaster according to one of claims 1 to 8, characterized in that the upper leg ( 13 ) of each throwing blade ( 8 ) in its outer section ( 20 ), which - seen from the center of the centrifugal disc ( 6 ) - beyond the outlet shaft ( 4 ) is located higher than the lower edge of the outlet shaft. 10. Centrifugal broadcaster according to one of claims 1 to 9, characterized in that the web ( 11 ) of the U-profile of each throwing blade ( 8 ) in its outer section with its inner edge ( 21 ) located at the transition to the higher leg ( 20 ) ) lies on a radius of the centrifugal disc ( 6 ), which is little larger than that which is the radially outermost limit of the outlet shaft ( 4 ). 11. Centrifugal broadcaster according to one of claims 1 to 10, characterized in that the higher leg ( 20 ) is arranged in the outer portion of the spreader vane ( 8 ) parallel to the bottom ( 2 ) of the storage container ( 1 ). 12. Centrifugal broadcaster according to one of claims 1 to 11, characterized in that the web ( 11 ) and the upper leg ( 13 ) of each throwing blade ( 8 ) at its inner end ( 16 , 17 ) at one in the center of the centrifugal disc ( 6th ) arranged cylindrical cap ( 15 ). 13. Centrifugal broadcaster according to one of claims 1 to 12, characterized in that the upper leg ( 13 ) bears at the inner end over the entire length of its edge on the cap ( 15 ). 14. Centrifugal broadcaster according to one of claims 1 to 13, characterized in that the leading edge ( 14 ) of the upper leg ( 13 ) at one of the contact point ( 16 ) of the web ( 11 ) on the cap ( 15 ) in the extension of Web approximately opposite point of the cap ( 15 ) attaches, in a first curvature ( 18 ) with increasing radial distance from the axis ( 7 ) of the scraper disc ( 6 ) is pulled forward and with a subsequent curvature ( 19 ) in one approximately parallel straight line to the web ( 11 ). 15. Centrifugal spreader according to one of claims 1 to 14, there characterized in that the first curvature of the front running edge is approximately spiral. 16. Centrifugal broadcaster according to one of claims 1 to 15, characterized in that the cap ( 15 ) projects upwards beyond the lower edge of the outlet shaft ( 4 ) which is close to it. 17. Centrifugal broadcaster according to one of claims 1 to 16, characterized in that the radius of the cap ( 15 ) is slightly smaller than the radius of the innermost limit of the outlet shaft ( 4 ) with respect to the axis ( 7 ) of the centrifugal disc ( 6 ) ). 18. Centrifugal broadcaster according to one of claims 1 to 17, with a drive shaft arranged below the centrifugal disc, on the hub of which the centrifugal disc is fastened, characterized in that the cap ( 15 ) for fastening the centrifugal disc ( 6 ) on the hub ( 24 ) serves. 19. Centrifugal broadcaster according to one of claims 1 to 18, characterized in that the throwing wing ( 8 ) is chamfered downwards at its outer end from the upper leg ( 13 , 20 ). 20. Centrifugal broadcaster according to one of claims 1 to 19, characterized in that the outlet shaft ( 4 ) has a cross section which increases from the outlet opening ( 3 ) downwards.