EP2021548B1 - Waved clearing bar - Google Patents

Description

The invention relates to a Räumbeiste for the plow blade of a snow plow which is provided in its remote from the road to be cleared area with a substantially planar mounting neck, which is intended to be grasped by fasteners and fixed to the plow blade, wherein at least parts of the fastening means extending in the direction of travel out of the plane of the attachment neck, wherein the cross section of the Räumleiste is bounded transversely to the longitudinal extent of a contour having in the road near two linear sections, of which the first portion is arranged with respect to the direction of travel of the snowplow so in that, when driving the snow plow, it scraps the snow off the road and conveys it upwards, while the second section runs parallel to the road surface and serves as a footprint exposed to constant wear and, over the entire length of the scraper blade or at least t in the region of the fastening means, the cross-section of the scraper above the first linear portion is bounded by a curved contour which passes between the road and the fastening neck lying outside the plane of the fastening neck vertex

Such Räumschilde are from the German utility model DE 81 29 044 U1 and DE 87 07 182 U1 as well as from the German patent DE 44 04 969 B4 the same applicant.

The scraper is a wearing part that is attached to the roadside end of the snowplow clearing blade. The scraper She is pushed onto the asphalt, scratches the snow from the road and leads it into the plow blade, which pushes the collected snow aside.

A conventional prior art scraper bar shows FIG. 1 , The curved plow blade 1 of a snow plow is guided in the direction of travel F along the road 2. At the street-side, lower end of the plow blade 1, a scraper blade 3 is mounted, with which the plow blade 1 presses against the road 2. At its upper end, the scraper 3 has a substantially planar attachment neck 4, with which the scraper blade 3 is attached to the Räumschlid 1. The attachment takes place with the aid of fastening means 5, which grip the scraper in the region of the fastening neck 4 and fix it on the plow blade 1. The fastening means 5 are usually screws (as in FIG. 1 represented and at the DE 81 29 044 U1 ) or clamping claws, which grip the scraper over a large area and press against the lower end of the Räumschlids 1. Klemmpratzen shows the DE 30 38 121 A1 , In addition, special fortifications are known, such as from the DE 101 47 393 A1 the same applicant.

When advancing in the direction of travel F, the scraper triggers 3 lying on the road 2 snow 6 and directs it upwards in the direction of the curved plow blade 1. Especially with fast clearances on highways, which are performed at 40 km / h, it comes because of the fast Flow speed of the snow to not insignificant Schneeverwirbelungen in the dozer blade, the foothills reach the windshield of the clearing vehicle and can clog them with snow. The driver's view is considerably limited. In the patent literature, some publications are known, which deal with the keeping away of the resulting in the plow blade snow vortex from the windshield. As an example, here are the US 5,309,653 and the DE 299 01 383 U1 ,

Both documents describe a large expenditure on equipment to curb the effects of snow whirling caused in the ploughshare. They do not recognize and treat the root cause of the problem. This can be seen in the parts of the fastener that stand out from the plane of the attachment neck out. These parts - in FIG. 1 The recorded snow 6 is swirled just below the screw head 7 in a turbulence zone 8, so that sets in the plow blade 1 a highly turbulent snow flow, whose foothills enforce the windshield, unless suitable interception devices are provided here.

Even if in particular screw heads occupy only a small portion of the total width of a scraper, investigations by the applicant show that even these small flow resistances exert considerable negative influence on the snow flow within the plow blade at the transition between scraper blade and plow blade. When using the Klemmpratzen this problem occurs even more unpleasant. The said not only applies to Räumleisten with a completely flat front, as in the FIG. 1 shown example, but also for Räumlelsten with a curved contour at the cross section, as shown in the DE 81 29 044 U 1 or the DE 44 04 969 B4 are known. As long as the contour is curved in the manner disclosed therein, the snow flow is also guided past the fastening means, which is why turbulence also occurs here.

The problems discussed above occur in a prior art ( EP 0 284 582 A2 ) known dozer blade with attached scraper not on. There, the scraper is namely provided with a plurality of each rotating about its longitudinal axis ice scraper teeth, seen in the longitudinal direction of the scraper have a distance from each other and replace with their rounded tips the ice from the road surface. In the process, the detached ice essentially passes between the ice-scraping teeth, so that the problems discussed above with snow flowing up quickly do not occur.

Furthermore, the disclosure US 1,944,307 a grading device for deepening and leveling a running along a paved road unpaved side strip, with a plurality of attached to a carrier leveling plates, which are profiled wavy at its front. They cover this Leveling plates completely behind the carrier, so that the flowing over the plates, detached from the road surface material can not encounter any flow resistance. Thus, the problem discussed above does not arise here either.

Based on the prior art of the type mentioned, the present invention has the object, the scraper blade for the snow blade of a snowplow educate so that a turbulent flow within the ploughshare is largely avoided, thus obstructing snowdrifts in the windshield of the spacecraft without to avoid additional equipment expense.

To solve this problem, the invention proposes, starting from a dozer blade of the type mentioned above, that the tangent to the curved contour is aligned parallel to the plane of the fastening neck, and that the tangent to the curved contour in a lying between the road and vertex adjacent point of the vertex pierces the plane of the fastening neck.

By inventively provided training the contour of the front of the scraper is formed between the first linear section and the mounting neck a streamlined hump, in the "snow shadow" are the protruding parts of the fastener. Thus, an impact of the snow on these flow obstacles and thus a swirling and cumming of the snow is effectively avoided.

The wave profile according to the invention need not be maintained over the entire length of the scraping. It is sufficient in principle to provide it only in the field of fasteners. However, the geometry of the scraping becomes more complex, the contour changes over the length, it creates different cross-sections. In the interest of manufacturing costs, it is therefore advisable to maintain the contour of the invention over the entire length of the scraper.

The shield effect of the hump is particularly effective when the vertex is as close as possible to the protruding part of the fastener Geometrically, this is achieved when the vertex of the vertex in the plane of the attachment neck has a smaller distance to the protruding part of the fastener than to the intersection of the plane with the road. The distances mentioned are each measured as measured within the plane. Due to wear of the scraper, the vertex "wanders" in the direction of the road; the distance of the vertex to the intersection decreases over the life of the scraper. Thus, the wear limit of the scraper is about reached when the distance of the vertex to the road is smaller than the protruding part.

The turbulence-free flow of snow in the ploughshare also has a positive effect on the evacuation: The sliding behavior of the scraper is improved, the snow is thrown by the wavy profile a little in the direction of travel and loosened by the wind and therefore flows better in the ploughshare from the side. The clearance is thereby reduced, the power requirement of the clearing vehicle decreases.

This effect is particularly effective when the vertex is in front of the plane, or even better, in front of the parts of the attachment means that are out of the plane of the attachment neck. "Before" is understood here in the direction of travel ahead.

As mentioned above, a scraper is a wearing part that wears at its street-side end. In known in the prior art scraper - see. FIG. 1 and DE 81 29 044 U1 - Is provided in the entire wear area of the scraper a constant footprint. With the curved contour according to the invention a variable thickness of the scraper in the direction of travel is accompanied by the wear area, which leads to uneven wear. To compensate for this, it is proposed to make the contour linear below the vertex. To compensate for a wavy contour on the front, it is also possible to provide on the back of the contour a sole point, the tangent of which is aligned parallel to the plane of the fastening neck.

The aerodynamically optimized scraper is preferably made of rubber. Since the rubber surface is too soft for the abrasive snow flow, it is recommended to reinforce the contour of the scraper at least in sections with steel. It is then a so-called sandwich scraper made of rubber and steel.

Conveniently, a hard material body is embedded in the rubber. This hard body slows the wear of the scraper on the road. The hard material body may optionally be embodied as a ceramic molded body or as a hard metal core surrounded by a steel shell. The ceramic molded body has the advantage that it can be produced by a sintering process, which allows a great deal of freedom in terms of the contour of the molded body. Thus, it is possible to let the contour of the molding run parallel to the contour of the scraper, whereby the proportion of ceramic in the wear surface always remains constant. The sintering process of the carbide core does not allow this, so it must be made with a linear contour. A flow dynamic not optimized scraper with carbide core describes the applicant in its disclosure DE 10 2004 029 165 A1 ,

As an alternative to rubber or sandwich designs, the invention can also be implemented as a solid steel scraper.

Fig. 1:

Herkömmliche Räumleiste im Querschnitt (Stand der Technik);

Fig. 2:

erfindungsgemäße Räumleiste im Querschnitt;

Fig. 2x:

Vergrößerung der Figur 2 im Bereich des Scheitelpunkts;

Fig. 3:

Strömungsverhalten der Räumleiste aus Figur 2;

Fig. 4:

Ausführungsform einer nicht erfindungsgemäßen Räumleiste im Querschnitt.

The present invention will now be explained in more detail by means of exemplary embodiments. For this show:

Fig. 1:

Conventional scraper in cross section (prior art);

Fig. 2:

Scraper strip according to the invention in cross section;

Fig. 2x:

Magnification of the FIG. 2 in the area of the vertex;

3:

Flow behavior of the scraper FIG. 2 ;

4:

Embodiment of a non-inventive scraper in cross section.

In the FIG. 2 illustrated scraper strip 3 according to the invention is fixed instead of a conventional scraper on the street-side end of a plow blade 1 by means of existing fasteners 5 on the mounting neck 4. Seen from the front, the planar mounting neck 4 extends within an imaginary plane 9. Due to the principle, parts 7 of the fastening means 5 protrude in the direction of travel F from the plane 9 to grip the mounting neck 4 and can fix. In FIG. 2 the fastener is designed as a simple screw. The part 7, which rises out of the plane 9, is the screw head 7. Nevertheless, parts of a clamping claw or a special attachment could protrude.

The in FIG. 2 represented cross section of the Räumleiste 3 is bounded by a contour that includes curved and linear sections. The contour is designed almost over its entire circumference as a curved contour 10, only in the region of the plane 9 of the fastening neck 4 and at its street end, the curved contour 10 is replaced by linear sections 11a, 11b, which will be explained later. The curvature of the Curved contour 10 can be described mathematically with the aid of tangents, which in each case conform to the contour 10 at one point.

Between road 2 and mounting neck 4, the curved contour 10 has a vertex 12; the associated tangent 13 extends here parallel to the plane 9 of the attachment neck 4. Immediately below the apex 12, in the direction of the road 2, is a neighboring point 14 whose tangent 15 pierces the plane 9 in a puncture point 16 below the apex 12. The neighboring point 14 is located at an infinitesimal distance below the apex 12. Since this is graphically barely representable and the puncture point 16 would be very far outside the drawing area, the neighboring point 14 is shown a bit further down shifted. In the embodiment shown, the contour 10 is concavely curved at the apex. In a convex curvature in the context of the invention, the puncture point 16 would be above the apex 12.

According to the concave curvature of the vertex 12 is in the embodiment of FIG. 1 Seen in the direction of travel before the imaginary plane 9. His vertical distance to the plane 9 is chosen so large that it projects beyond the protruding from the plane 9 parts 7. By felling the solder from the apex 12 to the plane 9, the imaginary soldering point 120 is found. The distance of the soldering point 120 to the screw head 7 is smaller in the plane 9 than the distance of the soldering point 120 to the imaginary intersection 160 of the plane 9 the road 2. By this constellation, the screw head 7 is comparatively close to the vertex.

In its region near the road, the scraper 3 has two linear sections 11a, 11b, a first 11a approximately transverse to the direction of travel F, a second 11b parallel to the asphalt surface of the road 2. The first linear region 11a extends over the preferred wear region h of FIG clearing bar. It serves to scrape the snow from the road and to promote towards the curvature in the area of the apex 12. The second linear Area 11b serves as a footprint of the scraper 2 and is constantly sanded.

On the back of the scraper 3, its contour 10 passes through a sole point 17, the tangent 171 of which also runs parallel to the plane 9 of the neck region 4. From the second linear section 11b to the sole point 17, the contour 10 describes a curvature which ensures an approximately constant axial thickness of the scraping strip 3 over the preferred wear area h, so that the wear is as uniform as possible. It is also possible to drive the scraper blade 3 beyond the preferred wear area h, in extreme cases to the roadside approach of the mounting collar 4. However, the effect according to the invention is lost as soon as the scraper blade 3 is worn beyond the apex 12.

The Räumleiste 3 consists in its interior of rubber, which is reinforced on the contour with vulcanised steel (not shown). In the wear region h, a hard material body 18 is embedded whose contour runs essentially parallel to the contour 10 of the scraper blade 3 in this region. The green compact of a ceramic hard material body can be shaped accordingly and then sintered. The hard material body 18 may extend over the entire length of the scraping strip 3 or a plurality of columnar hard material bodies may be embedded next to one another in the scraping strip 3.

The flow behavior of the scraper blade according to the invention FIG. 2 is in FIG. 3 shown. The snow 6 lying on the road 2 is released from the first linear section 11a and accelerated in the direction of the apex 12. Since the contour of the scraper blade behind the apex 12 lowers in the direction of the fastening neck 4, the snow stream 19 retains its flow direction parallel to the plane 9 and flows past the protruding parts 7 of the fastening 5 without being swirled there. In the plow blade 1, he is directed accordingly to the side. From the linear portion 11a to the attachment neck 4, the corrugated portion of the contour forms a streamlined projection in the region of the apex 12 in which "Snow shadow" the protruding parts 7 of the fastener 5 are. A swirling or cumming of the snow is thus effectively avoided.

FIG. 4 shows an embodiment of a non-inventive scraper. This is largely symmetrical and has in the preferred wear area h a particularly long linear portion 11 a, in which a hard material body 18 is located from a surrounding of a steel shell 20 hard metal core 21. Since the contour of the hard metal core can not assume any free-form surface, its contour is essentially linear and extends parallel to the linear section 11a in the preferred wear region h.

Claims (11)

1. Clearing bar for the clearing blade (1) of a snowplough, which, in the area facing away from the road (2) to be cleared, is provided with a substantially planar attachment neck (4) which is intended to be gripped by attachment means (5) and fixed to the clearing blade (1), wherein at least parts (7) of the attachment means (5) rise out of the plane (9) of the attachment neck (4) in the direction of travel (F), wherein the cross-section of the clearing bar (3) is delimited transverse to its longitudinal extension by a contour which has in the area close to the road two linear sections (11 a, 11 b), of which the first section (11 a) is arranged in relation to the direction of travel (F) of the snowplough such that, when the snowplough moves, it scrapes the snow from the road and conveys it upwards, while the second section (11 b) runs parallel to the road surface and serves as the contact area constantly exposed to wear, and wherein, over the whole length of the clearing bar (3) or at least in the area of the attachment means (5), the cross-section of the clearing bar (3) above the first linear section (11a) is delimited by a curved contour (10) which passes through an apex (12) lying outside of the plane (9) of the attachment neck (4) between road (2) and attachment neck (4), characterized in that the tangent (13) to the curved contour (10) at the apex (12) is aligned parallel to the plane (9) of the attachment neck (4), and in that the tangent (15) to the curved contour (10) at a neighbouring point (14) to the apex (12) lying between road (2) and apex (12) penetrates the plane (9) of the attachment neck (4).
2. Clearing bar (3) according to claim 1, characterized in that the apex (12) has a plumb point (120) in the plane (9) of the attachment neck (4), wherein the distance, measured within this plane (9), of this plumb point (120) from the projecting part (7) of the attachment means (5) is less than the distance, measured within this plane (9), of the plumb point (120) from the intersection point (160) of this plane (9) with the road (2).
3. Clearing bar (3) according to claim 1 or 2, characterized in that the apex (12), seen in the direction of travel (F), is located in front of the plane (9) of the attachment neck (4).
4. Clearing bar (3) according to claim 3, characterized in that the apex (12), seen in the direction of travel (F), is located in front of the projecting parts (7) of the attachment means (5).
5. Clearing bar (3) according to one of the previous claims, characterized in that the contour (10) between attachment neck (4) and road (2) passes through a bottom point (17) located behind the plane (9) of the attachment neck (4), wherein the tangent (171) to the contour (10) at the bottom point (17) is aligned parallel to the plane (9) of the attachment neck.
6. Clearing bar (3) according to one of the previous claims, characterized in that the clearing bar (3) is made at least partly of rubber.
7. Clearing bar (3) according to claim 6, characterized in that the contour (10) of the clearing bar (3) is reinforced with steel, at least in sections.
8. Clearing bar (3) according to claim 6 or 7, characterized in that at least one hard-material body (18) is embedded in the rubber.
9. Clearing bar (3) according to claim 8, characterized in that the hard-material body (18) is a ceramic shaped body the contour of which runs parallel to the contour (10) of the clearing bar.
10. Clearing bar (3) according to claim 9, characterized in that the hard-material body (18) is a hard-metal core (21) surrounded by a steel casing (20).
11. Clearing bar (3) according to claims 1 to 5, characterized in that the clearing bar (3) is made of steel.

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