EP3048242B1 - Wear protection cap - Google Patents

Description

The invention relates to a wear protection cap for a chisel holder assembly.

From the DE 10 2009 059 188 A1 a bit holder arrangement is known. This includes a base part and a chisel holder. The base part can be welded onto the outer surface of a milling drum tube. Then, the chisel holder can be replaceably attached to the base part. On the surface of the milling drum tube, a plurality of bit holder assemblies are fixed. They are preferably placed against each other so that the base parts form a clearing and Ladewendel. In the chisel holder, a chisel, preferably a rotatable round shank chisel, be interchangeable recorded. The from the DE 10 2009 059 188 A1 known chisel holder assemblies are used in mining, preferably open pit. During the machining operation, the chisels cut into the substrate to be removed and trigger material. The worn material flows laterally from the chisel and the chisel holder and then enters the area of the base parts that form the clearing and loading helix. Consequently, then transport the base parts of the space material in the region of the center of the Fräswalzenrohres. There it is then conveyed to a loading conveyor.

The material causes depending on its nature, a different levels of wear due to Abrassionsvorgängen. While softer formations such as coal tend to be less worn, significant wear can occur in iron ore containing materials. The chisels are subject to particularly severe wear and must therefore be changed at regular intervals. The chisel holders, on the other hand, are designed to last the life of a large number of chisels. The base part as the most expensive unit of the bit holder arrangement should offer a particularly long service life. In order to delay the cost-intensive exchange of the base parts, it is known from the prior art to weld armor plates in the form of steel sheets on particularly endangered areas of the base parts. This process in the Erstbestückung a milling drum is time-consuming, since a variety of filigree components must be handled, however, this can be achieved by a longer life. However, it has been shown that especially in the area of the weld seams the sheets are subject to increased wear. The heat generated by the welding process reduces the strength of the steel sheet in the area adjacent to the weld. Accordingly, there is a greater wear here compared to the other surface areas of the steel sheet. The armor plates accordingly solve uncontrolled by component failure after a certain period of use of the base part. The use of filler metal is time consuming and costly and thus increases the parts cost.

From the state of the art also other wear protection systems are known. For example, build-up welds directly on chisel holder or base parts applied by chisel holder assembly. In this way, an effective wear protection can be achieved, but the cost of applying the welds is considerable.

From the state of the art DE199 02 766 A1 a wear protection cap is known, which is designed as a forged part and has a wall portion with regions with different wall thickness. Two mutually spaced side walls are formed as wall sections and transferred via transition sections in the top wall.

From the DE 39 31 838 A1 a wear protection cap is known, which has three mutually angled side walls, which are merged into a top wall. In the top wall an opening is incorporated. The protective cap serves to cover a chisel holder. Through the opening a chisel can be inserted through its chisel shaft into a hole in the chisel holder.

It is an object of the invention to provide a wear protection system for a bit holder assembly with which an effective and durable protection of the bit holder assembly can be achieved.

This object is achieved with a wear protection cap which has wall sections for covering surface areas of the base part of the bit holder arrangement, wherein the wall sections are integrally connected to one another. The wear protection cap is designed as a casting or as a forged part, wherein a wall portion forms a top wall, which merges into a thickening, facing away from the thickening of the top wall, a front wall is connected as a further wall portion, wherein the front wall and the top wall are at an angle. Two mutually spaced side walls are formed as wall sections and are transferred via transition sections in the top wall. In the transition region between at least one of the side walls and the top wall, a thickening is arranged, which merges into the thickening in the transition region between the top wall and the front wall.

Because the wear protection cap is designed as a metal casting or metal forged part, uniform material properties can be achieved both in the region of the wall sections and in the region of the transition regions connecting the wall sections. Accordingly, both the wall portions and the transition areas between the wall portions provide equal material wear characteristics. Furthermore, with the wear protection caps in the form of metal castings or metal forgings various design variations can be achieve that are not feasible with the known sheet steel parts so. The wall sections are wear-optimized with different wall thickness, in particular a varying wall thickness curve formed. Accordingly, zones of greater wall thickness are pronounced in areas where heavy wear occurs. Zones that are exposed to less Abrassion, however, can be performed with a thinner cross-section material optimized. Furthermore, with the erfindungsgsmäßen original or formed parts also individually tailored to the application, flow-optimized Create geometries. This favors a low-wear drainage of the removed material.

According to the invention, the transitions between two wall sections are also designed with a larger wall thickness than at least one of the wall sections in order to provide a special wear protection here.

The wear protection cap is, as mentioned above, formed as a casting or as a metal forging. Accordingly, the wear protection cap is designed as a hot-formed part, in particular as a forged part, since higher wear resistance can be achieved here. Furthermore, can be realized with forged parts more diverse design options, such as varying cross-sectional profiles, as mentioned above.

For a low wear a continuous flow of Abraummateriales is advantageous. Accordingly, it can be provided according to a variant of the invention that at least a part of the wall sections is connected via rounding transitions into each other.

A particularly preferred variant of the invention provides that the wall sections are arranged such that they are suitable for forming a form-locking connection in the direction of the forces acting on the wear protection cap with the bit holder arrangement during the machining operation. In this way, a quasi-self-fixing construction of the wear protection cap is achieved. The wear protection cap can accordingly be fastened to the bit holder arrangement with simply designed fixing means. In particular, these fixing agents can be accommodated in areas where there is little risk of wear. In this Relation and also in connection with other variants of wear protection caps described in this patent application can be used as a fixative welds, in particular stitching or stitching points that connects the wear protection cap with the bit holder assembly.

The wear protection cap is adapted for use on a base portion of the bit holder assembly. Here it offers effective protection of the comparatively expensive component of the bit holder arrangement.

The wear protection cap has on the base part a wall portion in the form of a top wall, which merges via a transition section in a thickening, the thickening of the top wall turns away turned away in a front wall as a further wall section at an angle. This construction protects the extremely wear-prone front area of a base part. The thickening in the transition region between the top wall and the wall section brings an additional wear volume in favor of a long service life. Particularly preferably, the thickening forms a rounding transition to minimize the Abrassionsvorgänge here.

Furthermore, it is provided that two spaced-apart side walls are formed as wall sections and are transferred via transition sections in the top wall. The side walls protect the side areas of the base part and are thus ultimately associated with the transport area of the clearing and loading spiral of a milling drum. In addition, the side walls form a positive connection between the wear protection cap and the bit holder arrangement against forces acting laterally. Also in the transition region between the side walls and the top wall thickenings are provided. Due to the pitch of the spiral clearing and loading helices, a pressure side facing the delivery area is created, at which a particularly heavy wear takes place. Especially In this area of the pressure side, the provision of a thickening is advantageous.

In the context of the invention, it may further be provided that the top wall is recessed in a trough-like manner by means of the transition regions which lead into the thickenings. Thus, an expansion area for the bypassed waste material is formed in favor of less abrasion. Furthermore, the thickenings provide a protective barrier for the regions of the top wall which are in the opposite direction to the direction of movement, so that these regions are made wear-optimized. In particular, then, for example, a screw connection can be arranged in the trough-like region, which fixes a bit holder of the bit holder arrangement on the base part.

As mentioned above, the base parts may be fixed to each other on the surface of the milling drum tube to form a clearing and loading helix. In order to maintain the distance allocation of the base parts to each other, a recess is formed in a wear protection cap according to the invention in the transition region between the front wall and a laterally adjoining side wall. In the region of the recess, the base parts can be placed next to one another.

• Fig. 1 eine Meißelhalter-Anordnung mit Verschleißschutzkappen in perspektivischer Darstellung,
• Fig. 2 ein Basisteil der Meißelhalter-Anordnung gemäß Fig. 1 mit einer Verschleißschutzkappe in perspektivischer Explosionsdarstellung,
• Fig. 3 und 4 die Verschleißschutzkappe gemäß Fig. 2 in verschiedenen Ansichten,
• Fig. 5 einen Meißelhalter der Meißelhalter-Anordnung gemäß Fig. 1 zusammen mit einer nicht erfindungsgemäßen Verschleißschutzkappe in perspektivischer Darstellung und
• Fig. 6a bis 6e die Verschleißschutzkappe gemäß Fig. 5 in verschiedenen Ansichten.

The invention will be explained in more detail below with reference to exemplary embodiments illustrated in the drawings.
Show it:

• Fig. 1 a chisel holder arrangement with wear protection caps in perspective view,
• Fig. 2 a base part of the bit holder assembly according to Fig. 1 with a wear protection cap in a perspective exploded view,
• 3 and 4 the wear protection cap according to Fig. 2 in different views,
• Fig. 5 a bit holder of the bit holder assembly according to Fig. 1 together with a non-inventive wear protection cap in perspective and
• Fig. 6a to 6e the wear protection cap according to Fig. 5 in different views.

Fig. 1 shows a bit holder assembly, as is typically used in a surface miner. The bit holder arrangement has a base part 10 and a bit holder 40.

With reference to Fig. 2 the base part 10 will be explained in more detail below. As this illustration shows, the base part 10 is formed in one piece and has two side parts 11. These are arranged spaced from each other. Between the side parts 11, a plug-in receptacle 13 is formed. In the region of its underside 12, the base part 10 is provided with a concave surface. With this concave surface, the base part 10 can be placed flat on the surface of a not shown Fräswalzenrohres. It can then be fixed there on the Fräswalzenrohr with welds. In the region of its front side, the base part 10 has a front attachment to the side parts 11. This approach is bounded on the front side by a front surface 15 and a further front surface 16. The two front surfaces 15 and 16 are at an angle to each other and are via a transition section 15.1 merged into each other. The transition section 15.1 is designed as a rounding transition. In the region of the front surface 15, two mutually parallel spaced threaded receptacles 14 are introduced into the front approach of the base part 10. The threaded receptacles 14 open in the region of the plug-in receptacle 13 Fig. 2 can still recognize, the outer surfaces of the side parts 11 are passed over rounding transitions 15.2 in the front surfaces 15 and 16. In the area of the plug-in receptacle 13, the front attachment forms two mutually angled support surfaces 13.1. In this case, the support surfaces 13.1 may be formed as flat surfaces. Rearward, the plug-in receptacle 13 is also limited by two support surfaces 13.2. These two support surfaces 13.2 may also be formed flat and may extend in the direction of the central longitudinal axis of the plug-in receptacle 13. In the region of its rear side, the base part 10 is closed with a rear wall which forms a rear end surface 17.

With the base part 10, the wear protection cap 20 can be installed. As Fig. 2 can recognize, the wear protection cap 20 is integrally formed. It has a cover wall 21, which merges on the front side via a rising transition region 23 into a thickening 24.1. The thickening 24.1 serves to increase the material thickness of the wear protection cap 20. Accordingly, the wear protection cap 20 in the region of the thickening 24.1 has a greater wall thickness than the cover wall 21. Laterally, the top wall 21 also passes over a transition region 23 in a thickening 24.2. Here, too, a thickened cross-sectional area is formed. The top wall 21 is provided with two arcuate recesses 22. These recesses 22 merge into edge sections 22.1, which are employed in a V-shaped manner with respect to one another. The edge sections 22.1 terminate in further edge sections 22.2. The wear protection cap 20 has two side walls 27 and 28, which are arranged spaced from each other. Front side, the wear protection cap 20 is closed with a front wall 26. The side walls 27, 28 each go through rounding transitions 29 in the cover side of the wear protection cap 20 over. The side wall 28 passes via the rounding transition 29 directly into the top wall 21. The side wall 27 merges via the rounding transition 29 in the thickening 24.2. Furthermore, the front wall 26 passes over the rounding transition 25 in the thickening 24.1.

Fig. 2 shows further that the Verschißißschutzkappe 20 has a recess 20.1 in the region of the front wall 26 and in the front side region of the side wall 28.

For mounting the wear protection cap 20, this is placed over the base part 10. The two side walls 27 and 28 come to lie on the outer sides of the side parts 11. The top wall 21 lies with its rear side on the front surface 15. The front wall 26 is located on the back of the front surface 16. In the region of the recess 20.1, the base part 10 is exposed at the corner transition between the front surface 16 and the outside of the side part 11. In this area, another base member 10, which is not shown in the drawing, queued to form the clearing and loading helix on the Fräswalzenrohr. The two recesses 22 release the threaded receptacles 14. For securing the wear protection cap 20 to the base part 10 welded joints are used. For example, these may be located at wear-prone locations. In particular, for example, stitching seams may be provided in the region of the side walls 27, 28.

In Fig. 5 the bit holder 40 of the bit holder assembly is shown in exploded perspective view. As can be seen from this illustration, the bit holder 40 has a holding projection 44, to which an insertion projection 41 is integrally formed. The retaining lug 44 has a bit holder 45 in the form of a bore. Around the bore entry of the bit holder 45 around an annular seat 45.1 is arranged. Following the seat 45.1, the retaining lug 44 forms a inclined to the central longitudinal axis of the bit holder 45 extending discharge surface 46. The discharge surface 46 is the deck side in a lateral surface 47 and laterally in side parts 48 via. The retaining lug 44 has in the region of its underside two angularly arranged support surfaces 43.

The plug-in projection 41 has at the rear two mutually angled salaried bearing surfaces 41.1. In the area of the front side of the plug-in projection 41 is equipped with two pressure surfaces 42. The pressure surfaces 42 extend at an angle of less than 90 ° to the central longitudinal axis of the plug-in extension 41. The bit holder 40 can be installed with the above-described base part 10. For this purpose, the bit holder 40 is inserted with its plug-in projection 41 in the plug-in receptacle 13 of the base part 10. In the mounted state, the bit holder 40 is supported with its bearing surfaces 41.1 flat on the support surfaces 13.2 and with its two support surfaces 43 on the surface of the support surfaces 13.1 from. To fix the chisel holder 40, two fastening screws 30 (see Fig. 2 ) screwed into the screw receptacles 14. Pressure approaches of the fastening screws 30 then act on the pressure surfaces 42 of the bit holder 40 a. In this case, the bit holder 40 is pressed with its support surfaces 43 and the bearing surfaces 41.1 on the corresponding support surfaces 13.1, 13.2 of the base member 10. The assembly of the chisel holder 40 can be made with mounted wear protection cap 20.

As Fig. 5 can be seen further, a wear protection cap 50 can be installed with the bit holder 40. This wear protection cap 50 is detailed in the Fig. 6a to 6e shown. Accordingly, the wear protection cap 50 has a front wall 54 which is pierced by an opening 51. The opening 51 is bounded by an annular peripheral edge 52. Following the edge 52, the front wall 54 has a chamfer 53. The front wall 54 forms laterally spreading wing-like approaches, as the Fig. 6b For example, lets recognize. In the area of the free ends of the wing-shaped projections rearwardly projecting side walls 57 are integrally formed. The side walls 57 are also integrally connected to a top wall 55. The top wall 55 is also integrally connected to the front wall 54 in connection. As the Fig. 6b and 6e can recognize, the front wall 54 has a convex elevation. In the area of the convex elevation, a recess 56 is provided at the rear.

Fig. 5 shows further that the wear protection cap 50 are attached to the bit holder 40. In this case, the front wall 54 sits with its rear side on the discharge surface 46. The top wall 55 is supported on the lateral surface 47. The two side walls 57 face the outsides of the side parts 48. To attach the wear protection cap 50 welds are again provided on wear-prone locations. These connect the wear protection cap 50 with the bit holder 40. In the assembled state, the opening 51 of the wear protection cap 50 provides access to the bit receptacle 45. In addition, the opening 51 is dimensioned so that the seat 45.1 is free. This can be connected to the bit holder 40 a round shank chisel. The round shank chisel can be held with its round shank in the chisel holder 45, wherein the round shank chisel with its chisel head simultaneously supported on the seat surface 45.1.

If the wear caps 20 and 50 wear during operation, so they can be replaced if necessary. For this purpose, only the connecting means, for example, here, the stitching seams must be separated. This can be done on site with a corresponding cutting device. The worn wear caps 20 and 50 can then be replaced with new wear caps 20, 50. These are then fastened to the base part 10 and the bit holder 50 again. This repair can be done with a short repair time, reducing machine downtime.

The wear protection cap 20 has, in the context of the invention as wall sections, the side walls 27, 28, the front wall 26 and the top wall 21. The wear protection cap 50 has as wall sections the front wall 54, the top wall 55 and the side walls 57. The wall sections of the wear protection cap 20 are integrally connected to one another, wherein the wear protection caps are formed as a metal casting or metal forging.

Claims (5)

1. A wear protection cap (20) for a chisel holder arrangement, wherein the wear protection cap (20) is designed for use on a base part (10) of the chisel holder arrangement, comprising wall sections (21, 26, 27, 28) for covering surface regions of the base part, wherein the wall sections are integrally connected to one another and the wear protection cap (20) is formed as a cast part or as a forged part, wherein a wall section has a top wall (21) which merges into a thickened portion (24.1), wherein a front wall (26), facing away from the top wall (21), is connected as a further wall section to the thickened portion (24.1), wherein the front wall (26) and the top wall (21) are arranged at an angle to one another, wherein two side walls (27, 28) arranged at a distance from one another are designed as wall sections and are merged via transition sections into the top wall (21), and wherein a thickened portion (24.2) is arranged in the transition region between at least one of the side walls (27, 28) and the top wall (21), said thickened portion merging into the thickened portion (24.1) in the transition region between the top wall (21) and the front wall (26).
2. The closure cap (20) according to claim 1, characterised in that at least one part of the wall sections is merged into another by means of rounded transitions (25, 29).
3. The closure cap (20) according to claim 1 or 2, characterised in that the wall sections are arranged in such a way that same are suitable during machining use to form a form-fit connection with the base part in the direction of the forces acting on the wear protection cap.
4. The closure cap (20) according to one of claims 1 to 3, characterised in that the top wall (21) is set back in a trough-like manner by means of the transition regions (23) merging into the thickened portions (24.1, 24.2).
5. The closure cap (20) according to one of claims 1 to 4, characterised in that a recess (20.1) is formed in the transition region between the front wall (26) and a laterally adjoining side wall (28).

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