EP3929358A1 - Salt spreading unit - Google Patents

Abstract

A winter service gritter for a road service vehicle comprises a grit reservoir, a grit distribution unit that has at least one grit distribution unit that is driven in rotation and has throwing blades (8) on its upper side (O) and a feed unit that feeds the at least one grit disc (5 ) charged on its upper side (O) with grit removed from the grit reservoir (3). A central mixing projection (9) protrudes upwards from the spreading disc (5) on its upper side (O). Between the mixing projection (9) and the throwing blades (8) there is a ring zone free of throwing blades. And the scattering disc (5) has at least in an outer ring zone (R), which extends over 60% to 70% of the radius of the scattering disc (5), a radially downward gradient of between 1° and 12°.

Description

The present invention relates to a winter service spreader for a road service vehicle, comprising a spreading material storage container, at least one rotatingly driven spreading plate equipped with throwing blades on its upper side and having spreading material distribution unit, which has the at least one spreading plate on its upper side from the Litter material storage container charged with removed litter.

Winter service spreaders of this type are used every year to combat icy roads - by spreading, if necessary, moistened, thawing (e.g. salt) and / or dulling (e.g. grit) spreading material on traffic routes. There is also extensive prior art in printed literature, for example in the form of DE 10 2011 106 086 A1 , EP 1 491 686 A2 , EP 2 052 114 B1 , EP 1 636 428 B1 , DE 10 2016 114 420 A1 , DE 10 2005 012 886 A1 , JP 2012 144 888 A , JP 2011 094 450 A , JP 2010 024 723 A , JP 2007 120 287 A , CN 11 070 0177 A , CN 11 062 9725 A , CN 10 614 9617 B , CN 10 264 4258 A , CN 20 834 6742 U , CN 20 818 3637 U , CN 20 800 9347 U , CN 20 354 6665 U and RU 152 457 U1 .

Spreaders with centrifugal discs are also known in the field of agriculture, where they are used, in particular, for spreading fertilizer. In this regard, the prior art is, for example, the DE 1 222 728 B and the DE 35 29 452 A1 . However, given the different materials, their specific properties and characteristics as well as the different requirements and operating conditions, fertilizer spreaders and Winter service spreaders are regularly not interchangeable. In any case, no satisfactory results can be achieved with winter service spreaders when applying fertilizer to agricultural areas; and vice versa, the results that can be achieved using fertilizer spreaders in combating ice do not meet the existing high requirements.

It has also already been proposed, but without a practically feasible technical implementation being presented, to make the spreading plate of a winter road spreader adjustable in such a way that it either rises radially outward with an incline or falls with a incline.

Particularly with a view to minimizing environmentally damaging effects - as well as the costs of combating icy roads - great attention has been paid to achieving the most homogeneous spreading pattern possible, i.e. the most homogeneous spread of the spreading material over the spreading width, with the most exact adherence possible in the further development of generic winter service spreaders in recent years a given dosage. The progress that has been made is remarkable as long as the spread does not vary too much. However, the results are not yet satisfactory if the width of the traffic area to be covered by a winter road spreader changes significantly during a spreading operation, ie the spreading width has to be adapted to the local conditions within a considerable range. Especially for spreading applications, which, in addition to sections with medium and large spreading widths, also section sections with contain comparatively small spread, there is a lack of satisfactory solutions.

The present invention is aimed at making a contribution to solving this problem.

According to the present invention, the above-mentioned object is achieved in a surprisingly simple manner in that, as stated in claim 1, in a winter service spreader of the type specified at the beginning, the spreader plate is characterized by a plurality of positively synergetically interacting features in their specific combination by having a central mixing projection protruding upwards from the spreading plate on its upper side, between the mixing projection and the throwing blades there is an annular zone free of throwing blades and the spreading plate at least in an outer ring zone which extends over 60% to 70% of the radius of the spreading plate , has a radially outward downward gradient between 1 ° and 12 °, preferably between 3 ° and 8 °.

The design of the spreading plate according to the invention makes it possible to achieve a very high spreading pattern quality even with comparatively small spreading widths, without the quality of the spreading pattern being impaired as a result. In implementing the present invention, the working area of a winter road spreader (also) designed to sprinkle wide traffic routes can be extended substantially downwards, ie into the area of narrow traffic routes. This results in a winter service spreader with a previously unknown flexibility of use while at the same time providing a high quality spreading pattern over the entire area of use.

A possible explanation for the wide range of possible uses of the winter service spreader according to the invention could be that, due to the specific design of the spreading plate, two different phenomena can be used to a greater or lesser extent depending on the speed when spreading the spreading material . At rather high speeds of the spreading plate, as is essentially the case with the state of the art, the spreading material is primarily ejected or thrown with a considerable (throwning) effect of the throwing vanes; This applies to the operation of the spreader according to the invention intended for the spreading of wide traffic routes, whereby values of about 500 / min to 600 / min, possibly also 650 / min, are to be regarded as typical maximum speed of normally dimensioned spreading discs. In contrast, when the spreading plate rotates at comparatively low speeds, the spreading material is distributed by a type of "trickling" that is more relevant, in which the spreading material under the action of gravity is inclined downwards to a greater extent than in the case of high speeds Surface of the spreading plate moves outwards and leaves the spreading plate (at a comparatively low speed) according to the inclination of the surface of the spreading plate. Precisely because of the combination of the two effects, namely that the spreading material leaves the spreading plate with only a comparatively low "throwing speed" and the "throwing direction" imprinted on the spreading material has a downward component, can be, as explained above, under Use of the spreader device according to the invention (also) serve very small spreading widths with the formation of a spreading pattern that meets high quality requirements.

In this context, the central (co-rotating) mixing projection protruding upwards from the top of the spreader plate is important, in particular in connection with the further characteristic feature that there is a gap between the central mixing projection and the throwing vanes, the throwing vanes each other In words, do not extend as far as the mixing projection, but end radially inward at a distance from this. When the spreading material is applied to the spreading plate, at least a substantial part of the spreading material hits the mixing projection; For this purpose, the stream of scattering material is directed specifically against the mixing projection - by means of a corresponding configuration of the feeding unit that feeds it, which is matched to the scattering plate. In this way, the mixing projection, which can be designed in the form of a cylinder or truncated cone structured on its surface, provides an initial distribution of the spreading material on the spreading plate, which helps the formation of a very homogeneous spread pattern even and especially at very low speeds of the spreading plate. The ring zone that surrounds the mixing projection and is free of throwing blades promotes the homogeneous distribution of the spreading material on the spreading disc, which further promotes a uniform spreading pattern, especially at low spreading disc speeds.

A second effect could also serve as an explanation for the fact that, when using the present invention, with a very good quality spread pattern, it is also possible to spread very narrow traffic routes. Because of the inclination of the spreading plate, the movement of the spreading material on the spreading plate from the center to the edge, based on the effect of centrifugal forces, is caused by gravity supported, which reduces the risk that - at low speeds of the spreading disc - spreading material remains on the spreading plate and / or adheres to it, is reduced. This enables a stable spreading operation, which is characterized by maintaining a movement pattern of the spreading material on the spreading plate within a narrow band, even at very low speeds. With the spreading devices according to the invention - depending on the individual spreading material - a spreading operation that is stable in the above sense can be carried out even at (minimal) spreading disc speeds of only 75 / min. Even tests with spreader disc speeds of only 50 / min were successful.

According to a first particularly preferred embodiment of the invention, the annular zone, which has a downward gradient, is designed to be conical. In this way, the effects set out above can be achieved to a particularly pronounced extent.

In particular with a view to good results with large spreading widths (and correspondingly high speeds of the spreading plate), the throwing vanes, according to yet another advantageous development of the invention, are preferably inclined forward in the direction of rotation of the spreading plate. Said inclination supports a concentration of the litter moving along the throwing shovels at the foot area of the respective throwing shovel in order to form a "scattering material jet". In the foot area of the throwing blades, the angle of incidence of the throwing blades with respect to the spreading plate surface is preferably between 60 ° and 90 °, in particular approximately 70 ° to 85 °. It is particularly favorable when the forward inclination of the throwing blades increases above their height, ie when the Throwing blades protrude less steeply in an area at a distance from the surface of the spreading plate than adjacent to the surface of the spreading plate, ie in its foot area. The inclination can change continuously over a larger area of the extension of the throwing blades, so that the throwing blades appear arched. From a manufacturing point of view, however, an angled design of the throwing vanes with two flat regions of the throwing vanes that merge into one another at a more or less pronounced edge is particularly advantageous.

Yet another preferred development of the invention is characterized in that the height of the throwing vanes decreases radially outward. This favors a concentration in terms of height of the spreading material thrown off in a fan-shaped manner by the spreading plate at high rotational speeds and, accordingly, a comparatively small fluctuation range. For a particularly favorable spread pattern with rather small spreading widths (and correspondingly low spreading disc speeds), on the other hand, it has an advantageous effect if the base line of the throwing vanes on the spreading disc increasingly lags against the direction of rotation as the distance from the center increases. The deviation of the base line from a radial reference line is particularly preferably at least 10 °. Such a pronounced inclination of the throwing vanes with respect to the direction of rotation or circumferential direction again proves to be favorable with regard to a homogeneous spread pattern with small spread widths.

As far as the number of throwing shovels is concerned, it turns out to be for spreaders that are used for sprinkling traffic routes with widths between about 2m and about 6m should be suitable, between six and twelve, preferably between eight and twelve, particularly preferably between nine and eleven throwing shovels as favorable. When this operating range is shifted in the direction of higher spreading widths, a reduction in the number of throwing blades tends to be advantageous, so that, taking all circumstances into account, a number of exactly eight throwing blades can prove to be particularly favorable.

Finally, it proves to be advantageous if the radially inner delimitation of the throwing vanes is at an increasing distance from the axis of rotation with increasing height. This applies in particular to the presence of a central distribution projection (see above). In this way, the litter that bounces on and off the distribution projection can be better "caught" by the throwing vanes and directed onto the surface of the spreading plate in order to be thrown off according to its inclination. This is also favorable for the development of the trickle effect explained above.

Fig. 1

in Seitenansicht ein Streugerät nach der vorliegenden Erfindung,

Fig. 2

in perspektivischer Ansicht schräg von oben den Streuteller des Streugeräts nach Fig. 1 samt Wurfschaufeln und Mischkegel und

Fig. 3

in Seitenansicht den Streuteller nach Fig. 2 ohne Wurfschaufeln und Mischkegel.

The present invention is explained in more detail below with reference to a preferred exemplary embodiment illustrated in the drawing. It shows

Fig. 1

a side view of a spreader according to the present invention,

Fig. 2

in a perspective view obliquely from above the spreading plate of the spreader after Fig. 1 including throwing shovels and mixing cones and

Fig. 3

the spreader disc in side view Fig. 2 without throwing shovels and mixing cones.

The spreader 1 shown in the drawing is suitable for being mounted on a conventional carrier vehicle. Since this is well known from the prior art, the carrier vehicle was not shown. The spreader 1 also corresponds to the state of the art with regard to its basic structure, so that a detailed description is dispensed with and the latter (see, for example, FIG DE 10 2005 012 886 A1 ) can be referenced. In short, it comprises, in the usual way, a spreader frame 2, a spreading material storage container 3 supported thereon, a spreading material distribution unit 4 with a motorized spreading plate 5 which is driven to rotate about an essentially vertical axis X, and a feed unit 6. The latter in turn comprises a chute 7, which feeds the litter to the spreading plate 5, which is drawn off from the litter reservoir 3 in a metered manner by means of a screw conveyor. The spreading plate 5 is equipped with throwing blades 8 on its upper side O. Furthermore, a frustoconical central mixing projection 9 (mixing cone 10), which is profiled on its circumference, projects upwards from the spreader plate 5 on its upper side O.

The spreading plate 5, ie its upwardly facing surface exposed to the spreading material applied, has an outer ring zone R with a downward gradient. This is conical (with an angle of inclination A of about 5 °) and extends, surrounding the mixing cone 10, over about 65% of the radius of the spreading plate 5. The throwing vanes 8 are on the ring zone R, which has a downward gradient of the spreading plate 5, keeping a distance from the mixing cone 10. They are inclined forward in the direction of rotation B of the spreading plate 5, wherein in the foot region of the throwing blades 8, ie near the surface of the Spreading plate 5, the angle of attack C of the throwing blades 8 with respect to the spreading plate surface is about 80 °.

At a distance from the spreading plate surface, the throwing vanes 8 are bent forward in the direction of rotation B, so that the forward inclination of the throwing vanes 8 increases over their height. Since the distance between the relevant edge K and the spreading plate surface decreases with increasing distance from the spreading plate axis X, the height of the throwing vanes 8 also decreases radially outward. The radially inner delimitation 11 of the throwing blades 8 has an increasing distance from the axis of rotation X with increasing height. Incidentally, the throwing vanes 8 are not oriented radially, but rather positioned in relation to the circumferential direction U in such a way that the base line 12 of the throwing vanes 8 on the surface of the spreading plate 5 increasingly lags against the direction of rotation B as the distance from the center increases.

Claims (10)

Winter service spreader (1) for a road service vehicle, comprising a spreading material storage container (3), a spreading material distribution unit (4) with at least one rotatingly driven spreading plate (5) equipped with throwing blades (8) on its upper side (O) and a Feeding unit (6) which feeds the at least one spreading plate (5) on its upper side (O) with spreading material withdrawn from the littering material storage container (3),
whereby
a central mixing projection (9) protrudes upwards from the spreading plate (5) on the top side (O), between the mixing projection (9) and the throwing blades (8) there is an annular zone free of throwing blades and the spreading plate (5) at least in an outer one Annular zone (R), which extends over 60% to 70% of the radius of the spreading plate (5), has a gradient between 1 ° and 12 ° directed radially outwards and downwards. Winter service spreader according to claim 1, characterized in that the downward gradient is between 3 ° and 8 °. Winter service spreader according to Claim 1 or Claim 2, characterized in that the annular zone (R) having a downward gradient is designed to be conical. Winter service spreader according to one of Claims 1 to 3, characterized in that the mixing projection (9) is designed in the form of a cylinder or truncated cone. Winter service spreader according to one of Claims 1 to 4, characterized in that the throwing blades (8) are inclined forwards in the direction of rotation (B) of the spreading plate (5). Winter service spreader according to claim 5, characterized in that the forward inclination of the throwing blades (8) increases over their height. Winter service spreader according to claim 5 or claim 6, characterized in that in the foot area of the throwing shovels (8) the angle (C) of the throwing shovels (8) with respect to the surface of the spreading disc is between 60 ° and 90 °. Winter service spreader according to one of Claims 1 to 7, characterized in that the height of the throwing vanes (8) decreases radially outwards. Winter service spreader according to one of Claims 1 to 8, characterized in that the base line (12) of the throwing shovels (8) on the spreading plate (5) increasingly lags against the direction of rotation (B) with increasing distance from the center. Winter service spreader according to one of Claims 1 to 9, characterized in that the radially inner limitation (11) of the throwing shovels (8) has an increasing distance from the axis of rotation (X) with increasing height.

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