EP1780375A1 - Cutting tooth for earth working equipment - Google Patents

Abstract

Cutting tooth has foot to sit in a seat on the ground treatment appliance and at least one main cutting part is located on the cutting foot on the head side to treat the ground material. To enlarge the treatment area of the main cutting piece situated on the foot, a further post cutting piece is provided. It has a different cutting design compared to the main cutting piece. The post cutting piece has a pin blade. The main cutting piece has at least one wedge-shaped blade.

Description

The invention relates to a cutting tooth for a harrow, in particular for a cutting wheel of a trench cutter according to the preamble of claim 1. Such a cutting tooth has a tooth root for receiving in a holder of the harrow and at least one head cutting element arranged on the main cutting element for processing soil material.

Such cutting teeth are for example from the DE 297 20 261 U1 and the DE 87 15 141 U1 known and used in civil engineering trench wall milling for the production of slot walls. The cutting teeth can be used in particular in wheel milling, where they are arranged on the lateral surfaces of the cutting wheels. For producing a slot, the cutting wheels are set in rotation and lowered into the ground, wherein the cutting teeth break up and loosen the soil material present on the cutting wheels so that they can be sucked off, for example by means of a pump, and / or processed into a suspension.

Milling wheels for tillage are often constructed disc-like over an underlying, in particular cylindrical, wheel body, wherein the disc axis coincides with the axis of rotation of the cutting wheel. In the disc areas of the cutting wheel, the cutting teeth and optionally their holders are arranged.

Between these discs arranged on the Fräsradrahmen, fixed reamer between the cutting teeth and possibly also their holder engage. During the milling process, the scrapers form counterholds and give them a firm resistance, so that counter pressure on the moving cutting teeth causes even harder stone material to be broken.

The known cutting teeth have a shaft-like tooth root for receiving in the Fräszahnhaltern. At an upper edge of the cutting tooth, a carbide cutting edge for cutting the upcoming soil is provided.

The width of the cutting tooth cutting edge is chosen above all depending on the soil to be worked. For harder rock material a narrower cutting width is generally advantageous. By reducing the cutting width, a higher contact pressure can be achieved with otherwise identical milling design, which increases the milling progress, especially in hard geologies. There are therefore known cutting teeth, in which the cutting edge is formed narrower than the underlying end face of the tooth root.

In order to avoid excessive wear of the comparatively wider tooth roots and possibly also the Fräszahnhalter in such cutting teeth with a narrow cutting width, it is necessary to arrange a plurality of cutting teeth behind one another on a circumferential line of the cutting wheel angularly. This ensures that the cutting-free Zahnfußabschnitte and the holder are cut free by circumferentially subsequent cutting teeth. Alternate inclination of the cutting teeth by a few degrees to the side may also be required to cut free the clearing areas located between the milling toothed disc areas. For angled arrangement In particular, their holders can be arranged laterally inclined on the circumference of the cutting wheel of the teeth.

However, a laterally tilted arrangement of the individual cutting teeth on the cutting wheel makes it necessary for different types of cutting teeth to be arranged on one and the same cutting wheel. In principle, each angular position requires its own milling tooth type designed for this angular position. Thus, it may be necessary for the inclined holders that the carbide cutting edge is offset depending on the tooth inclination on the right or left side with respect to the middle of the cutting teeth, whereas with non-inclined cutting teeth the cutting edge is arranged centrally.

This makes it necessary to keep a variety of Fräszahnausführungen stock on the site in an uneconomical way. In addition, there is the danger that when replacing the cutting teeth for the respective inclination unsuitable cutting tooth is installed, which can lead to premature wear and increased spare parts costs.

The object of the invention is to provide a particularly economical and versatile cutting tooth, which is particularly suitable for harder soil geologies.

The object is achieved by a cutting tooth with the features of claim 1. Preferred embodiments are given in the dependent claims.

The cutting tooth according to the invention is characterized in that, in order to widen the processing cross section of the main cutting element, at least one further recutting element is provided on the head side on the tooth root, which has a different cutting edge design compared to the main cutting element.

A basic idea of the invention can be seen in the fact that the entire processing width of the cutting tooth is not made available by a single cutting element, but rather to provide a plurality of cutting elements on the tooth head, which are laterally offset from one another transversely to the milling direction. According to the invention, a plurality of different types of cutting are combined for clearing soil material over the entire processing width. Experiments have shown that with such a cutting edge design compared to previously known types of teeth with a single cutting edge, especially in harder soils, higher milling progress can be achieved.

This observation may be due to the fact that the individual cutting elements do not tear the pending soil independently. Thus, a major cutting element leading in the direction of the milling can weaken the pending rock structure outside its geometric cross-section and thus pre-solve it. For complete processing of this pre-dissolved rock through the trimmer only a comparatively low cutting performance is required, which can be applied by simply designed cutting elements.

Thus, according to the invention, for example, a cutting tooth can be provided with a main cutting element which is narrower with respect to the holder and / or the tooth root, in order to be able to machine harder soils and thereby achieve a sufficient milling progress. The main cutting element can be attached, for example, frontally centered on the tooth root. In order to ensure the free-cutting function of the tooth, additional trimmers are provided according to the invention, which can be arranged in particular symmetrically to the main cutting element. These reamers broaden the overall processing cross section of the cutting tooth. Therefore, with a small main cutting element and thus good milling progress, a total milling width greater than the width of the tooth root and / or its holder is achieved. Thus, with the cutting teeth according to the invention, the holders and the clearing areas arranged between the cutting wheel disks can be reliably cut free with good milling progress without the inclination of the cutting teeth being required for this purpose.

The invention thus makes it possible to provide only a single Fräszahntyp for a large part of the tooth positions on the cutting wheel, which significantly minimizes the cost of spare parts and also significantly reduces the risk of faulty dental installation. The invention makes it possible to equip with a tooth stock almost the entire cutting disc.

For a particularly good milling progress in a variety of soil geologies, it is advantageous that the main cutting element has at least one wedge-shaped cutting edge. The cutting edge of the main cutting element then has a longitudinal extension and can also be referred to as a linear cutting edge. A wedge-shaped cutting edge is particularly well suited for cutting the upcoming soil, especially on hard soils.

Furthermore, it is advantageous that the recutting element has at least one pin cutting edge. In particular, such a pencil cutting edge can be cone-shaped, wherein the cone can, for example, have a round or oval base surface. A pencil cutting edge is particularly well suited for the final cutting of the soil material already loosened by the main cutting element. In addition, the arrangement of an additional pin edge due to their small footprint reduces the total contact pressure of the trench wall cutter only slightly, so that the milling progress of the main cutting element is at most slightly affected. In addition are Pen cutting also comparatively inexpensive and require a relatively small soldering surface on the tooth root. The pencil edge can also be referred to as a point cutting edge. For a good milling progress, it is usually advantageous that the main cutting element has a more aggressive cutting edge compared to the Nachschneidelement.

Suitably, at least the two cutting elements made of hard metal, for the tooth root from the point of view of economy, a less hard material can be used. The tooth root is, in particular together with receptacles for the cutting elements, advantageously made of cast metal.

A particularly cost-effective and at the same time powerful cutting tooth is given by the fact that the Nachschneidelement has a round shank chisel. Such a round shank chisel typically has a shank and a cross-sectionally larger head arranged thereon, on the end of which a hard metal pin is provided. The round shank bit can be designed as a simple cutting pin.

According to a preferred embodiment of the invention, it is advantageous that at least one receiving sleeve, in particular with a circular or elliptical inner cross section, is provided on the tooth root, in which the at least one regrooving element, preferably interchangeable, is arranged. As a result, a particularly simple constructed and versatile cutting tooth is obtained.

According to the invention, the main cutting element is aligned for root removal in a main cutting direction on the tooth root. The main cutting direction can also be referred to as a milling direction and in particular represents the direction in which the cutting tooth due to the pure rotational movement of the cutting wheel moved tangentially. Perpendicular to the direction of milling extends the feed direction of the cutting tooth, which corresponds in particular to the radial direction of the cutting wheel. Suitably, the Zahnfußlängsachse runs at least approximately parallel to the feed direction.

A particularly good milling progress can be achieved in that the main cutting element is arranged ahead of the Nachschneidelement in the main cutting direction leading the tooth root. Advantageously, the main cutting element is provided at the front side, at the end face facing the adjacent soil material, at the tooth root. In particular, it can protrude at least in sections over the end face of the tooth root in the main cutting direction. Suitably, the main cutting element is preceded by a cutting support region arranged at the top end on the tooth root, on which in turn the recutting element and optionally its receptacle are provided.

A particularly high contact pressure and thus a particularly good Fräsfortschnitt can be achieved in that the cutting width of the main cutting element is smaller than the width of the tooth root. The cutting width of the main cutting element can generally vary over its height. In particular, the dimension of the removal cross section of the main cutting element perpendicular to the main cutting direction and perpendicular to the feed direction of the cutting tooth can be understood as the cutting width.

A further advantageous embodiment of the cutting tooth according to the invention is characterized in that, when viewed in the main cutting direction, the recutting element protrudes laterally over the main cutting element and in particular over the tooth root. Preferably, the Nachschneidelement protrudes on both sides beyond the main cutting element or the tooth root, for which purpose at least two recutting elements can be provided. Such an arrangement allows a safe free cutting of the tooth root and possibly arranged on the cutting wheel spaces for Räumerelemente. In particular, a protrusion protruding transversely to the direction of advance and / or the longitudinal axis of the tooth root is understood to mean a lateral protrusion.

A cutting tooth with a particularly reliable free-cutting function results from the fact that at least two recutting elements are provided. Suitably, when viewed in the main cutting direction on both sides of the main cutting element each a Nachschneidelement is arranged. A cutting tooth that is particularly suitable and thus robust for receiving the operating forces is obtained in that the main cutting element, the recutting elements and in particular the tooth root are constructed with mirror symmetry. The plane of symmetry is suitably in the main cutting direction.

The milling progress can be further improved by the fact that the main cutting element has at least one longitudinal cutting edge running transversely to the main cutting direction. The longitudinal cutting edge is suitably followed by two secondary cutting edges in a V-shaped manner. While the longitudinal cutting edge suitably extends approximately in the feed direction, the secondary cutting edges suitably extend transversely to the feed direction from the cutting tooth center to the longitudinal sides of the tooth root. Preferably, two or more slitters are provided parallel to each other.

The cutting tooth according to the invention can also be used as a folding tooth, which is tilted in response to the rotation angle of the cutting wheel to cut free axially displaced bottom regions. If the cutting tooth is to be used as a folding tooth, then it is advantageous for the at least one regrooving element, viewed in the main cutting direction, to be arranged only to one side of the main cutting element. Advantageously, the recutting element is arranged so that it tilts when tilted folding tooth, so if the longitudinal axis of the tooth deviates from the radial direction of the cutting wheel, the pending below the cutting wheel floor.

A milling tooth according to the invention can also be used as a so-called caliber tooth, which is arranged on the axially outer outer disks of the cutting wheel in order to cut free the outer region of the cutting wheel, that is to say its end surfaces. Also in this case, the recutting element is preferably arranged only on one side with respect to the main cutting element. If the cutting tooth is to be used as a caliber tooth, then at least one further cutting element is suitably arranged on the tooth root on the side of the cutting tooth on which the recutting element is also located. Preferably, the further cutting element is constructed identically with the recutting element and in particular has a pin cutting edge. Suitably, the further cutting element is arranged on the tooth root below the re-cutting element. Preferably, a plurality of cutting elements are provided in the longitudinal direction of the tooth root. As a result, the cutting action in the outer region of the cutting wheel can be improved.

In particular, when used as a folding tooth or as a caliber tooth, it is advantageous that the longitudinal cutting edge is offset laterally relative to a center plane of the tooth root when viewed in the main cutting direction. In a caliber tooth, the longitudinal cutting edge is suitably offset from the recutting element, with a folding tooth from the recutting element path. In the case of a caliber tooth, the longitudinal cutting edge is preferably offset to the outside of the cutting wheel.

The cutting wheels can, with the exception of the non-existent Nachschneidelements basically as in the DE 297 20 261 U1 and the DE 87 15 141 U1 be described and can be described in one in the DE 87 15 141 U1 described Fräszahnhalter be inserted. Aside from a wheel cutter, the cutting teeth according to the invention can in principle also be used on a chain cutter. A trench wall cutter designed to use the cutting teeth according to the invention advantageously has two pairs of cutting wheels which are arranged axially parallel to the underside of a frame.

Fig. 1

eine perspektivische Ansicht eines ersten Ausführungsbeispiels eines erfindungsgemäßen Fräszahns;

Fig. 2

eine Seitenansicht des Fräszahns aus Fig. 1;

Fig. 3

eine Rückansicht des Fräszahns aus Fig. 1;

Fig. 4

eine Draufsicht des Fräszahns aus Fig. 1;

Fig. 5

ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Fräszahns, der als Klappzahn ausgebildet ist, in perspektivischer Ansicht;

Fig. 6

eine Seitenansicht des Fräszahns aus Fig. 5;

Fig. 7

eine Frontansicht des Fräszahns aus Fig. 5;

Fig. 8

eine Draufsicht des Fräszahnes aus Fig. 5;

Fig. 9

ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Fräszahns, der als Kaliberzahn ausgebildet ist, in perspektivischer Ansicht;

Fig. 10

eine Seitenansicht des Fräszahns aus Fig. 9;

Fig. 11

eine Rückansicht des Fräszahns aus Fig. 9; und

Fig. 12

eine Draufsicht des Fräszahns aus Fig. 9.

The invention will be explained in more detail with reference to preferred embodiments, which are shown schematically in the figures. In the figures show:

Fig. 1

a perspective view of a first embodiment of a cutting tooth according to the invention;

Fig. 2

a side view of the cutting tooth of Fig. 1;

Fig. 3

a rear view of the cutting tooth of Fig. 1;

Fig. 4

a plan view of the cutting tooth of Fig. 1;

Fig. 5

a further embodiment of a cutting tooth according to the invention, which is designed as a folding tooth, in a perspective view;

Fig. 6

a side view of the cutting tooth of Fig. 5;

Fig. 7

a front view of the cutting tooth of Fig. 5;

Fig. 8

a plan view of the cutting tooth of Fig. 5;

Fig. 9

a further embodiment of a cutting tooth according to the invention, which is designed as a caliber tooth, in a perspective view;

Fig. 10

a side view of the cutting tooth of Fig. 9;

Fig. 11

a rear view of the cutting tooth of Fig. 9; and

Fig. 12

a top view of the cutting tooth of FIG. 9th

Similar elements are identified in all embodiments with the same reference numerals.

A first embodiment of a cutting tooth according to the invention is shown in FIGS. 1 to 4. The cutting tooth has on its lower side on a tooth root 10 for receiving in a Fräszahnhalter. The tooth root 10 is formed in the side view (FIG. 2) in a U-shape with two parallel end edges and a rounded foot portion. At the two end sides of the cutting tooth, which extend approximately radially in an arrangement on a cutting wheel, and in the foot region of the tooth root 10, a longitudinal groove 16 is formed with a substantially V-shaped cross-section. The longitudinal groove 16 is part of a positive connection, via which the cutting tooth is releasably secured in the cutting tooth holder, not shown.

The tooth root 10 also has a transverse hole 17 which intersects both the longitudinal groove 16 and the adjacent solid part of the tooth root 10. The transverse hole 17 serves to receive a shear pin in order to secure the cutting tooth 10 in the milling tooth holder. Next to the tooth root 10 is another transverse hole 18 is provided, which can serve to insert a tool when pulling out the cutting tooth from the Fräszahnhalter.

For milling operation, the cutting tooth is inserted via its tooth root 10 into the cutting tooth holder on a cutting wheel. The cutting wheel is set in rotation around its cutting wheel axis, whereby the cutting tooth is moved tangentially in a main cutting direction 60. At the same time the cutting wheel is retracted linearly into the ground, whereby a movement of the cutting tooth in the direction perpendicular to the main cutting direction 60 extending feed direction 65 results.

At the top of the tooth root 10, a main cutting element 20 made of hard metal is arranged. The main cutting element is polyhedron-like and has a wedge-shaped longitudinal cutting edge 22 which extends perpendicular to the main cutting direction 60 approximately parallel to the feed direction 65 and to the longitudinal axis of the tooth root 10 from the tooth root 10 upwards.

The main cutting element 20 is arranged frontally on the cutting tooth, wherein the longitudinal cutting edge 22 protrudes beyond the underlying end face of the tooth root 10. At the top of the main cutting element 20, two secondary cutting edges 23, 23 'are provided, which branch off from the longitudinal cutting edge 22 in a V shape. In this case, the secondary cutting edges 23, 23 'extend transversely to the main cutting direction 60 to the outside. On its rear side facing away from the longitudinal cutting edge 22, the main cutting element 20 is supported by a cutting support region 14, the height of which decreases with increasing distance from the main cutting element 20.

Behind the frontally arranged main cutting element 20, two recutting elements 30, 30 'are provided on the head side on the tooth base 10. As in Figs. 1 and 4 using the example of Nachschneidelements 30, the recutting elements 30, 30 'each have a round shank bit 33 with a conical tip area. At the top of the round shank chisel 33, a conical pin cutting edge 32 made of hard metal is arranged.

For holding the Nachschneidelemente 30, 30 'are on the head side of the tooth root 10 in the rear portion of the cutting support portion 14 has two receiving sleeves 37, 37' is provided. In these receiving sleeves 37, 37 ', which may in particular have a round or an elliptical inner cross-section, the round shank chisel 33 of the Nachschneidelemente 30, 30' are inserted. The Nachschneidelemente 30, 30 'are arranged so that their pencil cutting edges 32 seen in the main cutting direction 60 laterally, that is transversely to the feed direction 65, project beyond the main cutting element 20, so that the entire Abtragungsquerschnitt the cutting tooth wider than the geometric width of the main cutting element 20 and the Secondary cutting 23, 23 'is. As can be seen in particular from FIGS. 3 and 4, the pencil cutters 32 also protrude laterally beyond the underlying tooth root 10, so that the regrooving elements 30, 30 'cut free the tooth over its entire width. In the feed direction 65, the pin cutting edge 32 and the upper end of the longitudinal cutting edge 22, from which the secondary cutting edges 23, 23 'extend, are arranged approximately at the same height.

The Nachschneidelemente 30, 30 'are arranged behind the main cutting element 20, that is, the cutting edges 22, 23, 23' of the main cutting element 20 rush the pencil cutting edges 32 of the Nachschneidelemente 30, 30 'in the main cutting direction 60 ahead.

The longitudinal axes of the round shank chisel 33 of the two regrooving elements 30, 30 'are arranged approximately V-shaped relative to each other. The longitudinal axes are opposite to the feed direction 65 tilted both in the main cutting direction 60 and to the sides of the cutting tooth.

As can be seen in particular FIGS. 3 and 4, the main cutting element 20 is arranged centrally on the end face of the tooth, wherein the longitudinal cutting edge 22 extends in the middle of the end face. The entire cutting tooth together with the main cutting element 20 and the Nachschneidelementen 30, 30 'is constructed mirror-symmetrically, the longitudinal cutting edge 22 of the main cutting element 20 is located in the plane of symmetry.

A further embodiment of a cutting tooth according to the invention, which can be used in particular as a folding tooth, is shown in FIGS. 5 to 8. The tooth root 10 of this cutting tooth substantially corresponds to the tooth root of the cutting tooth of FIGS. 1 to 4 and will therefore not be explained again.

The cutting tooth illustrated in FIGS. 5 to 8 differs from the previously described cutting tooth essentially in that the main cutting element 20 is arranged not centrally but laterally offset on the end face of the cutting tooth. In contrast to the above-described cutting tooth, according to the embodiment of FIGS. 5 to 8, a recutting element 30 is additionally provided only on one side of the main cutting element 20. Here, the Nachschneidelement 30 is disposed on that side of the tooth root 10, of which the main cutting element 20 is offset from the tooth center away.

Although the main cutting element 20 in itself has a mirror symmetry, the entire cutting tooth is not mirror-symmetrical due to the offset of the main cutting element 20 and the only one-sided arrangement of the Nachschneidelements 30.

A further embodiment of a cutting tooth according to the invention, which can be used in particular as a caliber tooth, is shown in FIGS. 9 to 12. The tooth root 10 of this tooth, in turn, essentially corresponds to the tooth root 10 of the cutting tooth of FIGS. 1 to 4 and will therefore not be explained again.

In contrast to the above-described cutting teeth, the main cutting element 20 of the embodiment of FIGS. 9 to 12 has a width transverse to the main cutting direction 60 that is greater than the width of the underlying tooth root 10, that is, the main cutting element 20 is laterally on one side over the tooth root 10 over. In this case, the longitudinal cutting edge 22 is arranged eccentrically offset on the main cutting element 20 in the direction of the lateral projection.

Also in the embodiment of Figs. 9 to 12, only a single Nachschneidelement 30 is provided, seen in the main cutting direction 60 on the side of the cutting tooth on which the main cutting element 20 projects beyond the tooth root 10.

Relative to the feed direction 65, the pin edge 32 of the re-cutting element 30 is arranged approximately at the same height of the main cutting element 20. Below the re-cutting element 30, two further cutting elements 77, 78 are arranged laterally on the tooth base 10, which also have round shank bits. The longitudinal axes of the round shank chisel of the further cutting elements 77, 78 thereby run approximately parallel to the longitudinal axis of the round shank chisel of the regrooving element 30. However, these can also be offset from one another in the main cutting direction 60.

The main cutting elements 20 of the embodiments of FIGS. 5 to 12 respectively close on their the Nachschneidelementen 30 facing away from longitudinal sides approximately flush with the underlying flanks of the tooth roots 10 from.

Claims (10)

Milling tooth for a harrow, in particular for a cutting wheel of a trench cutter, with - A tooth base (10) for receiving in a holder of the harrow and at least one main cutting element (20) arranged at the top end on the tooth root (10) for processing soil material, characterized , - That for broadening the Abarbeitungsquerschnittes of the main cutting element (20) at the head end on the tooth root (10) at least one further Nachschneidelement (30) is provided, which compared with the main cutting element (20) has a different cutting edge design. Milling tooth according to claim 1,
characterized,
that the main cutting element (20) has at least one wedge-shaped cutting edge, and
in that the regrooving element (30) has a pin cutting edge (32). Milling tooth according to one of claims 1 or 2,
characterized ,
in that the regrooving element (30) has a round shank chisel (33). Milling tooth according to one of claims 1 to 3,
characterized ,
in that at least one receiving sleeve (37), in particular with a circular or oval inner cross section, is provided on the tooth root (10), in which the at least one regrooving element (30), preferably interchangeable, is arranged. Milling tooth according to one of claims 1 to 4,
characterized , - That the main cutting element (20) for a Bodenabtragung in a main cutting direction (60) is aligned with the tooth root (10), and - That the main cutting element (20) with respect to the Nachschneidelement (30) in the main cutting direction (60) leading to the tooth root (10) is arranged. Milling tooth according to one of claims 1 to 5,
characterized ,
that the cutting width of the main cutting element (20) is smaller than the width of the tooth base (10). Milling tooth according to one of claims 1 to 6,
characterized ,
in that the trim-cutting element (30) projects laterally beyond the main cutting element (20) and in particular over the tooth root (10) when viewed in the main cutting direction (60). Milling tooth according to one of claims 1 to 7,
characterized ,
in that at least two recutting elements (30) are provided, wherein the main cutting element (20), the recutting elements (30) and in particular the tooth root (10) are preferably constructed mirror-symmetrically. Milling tooth according to one of claims 1 to 8,
characterized ,
in that the main cutting element (20) has at least one longitudinal cutting edge (22) extending transversely to the main cutting direction (60), to which two secondary cutting edges (23, 23 ') adjoin in a V-shaped manner. Milling tooth according to claim 9,
characterized,
that the longitudinal edge (22) with respect to a center plane of the tooth base (10) is laterally offset as seen in the main cutting direction (60).

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