EP3259447A1

EP3259447A1 - Pick comprising a support element with a centering insert

Info

Publication number: EP3259447A1
Application number: EP17720767.7A
Authority: EP
Inventors: Ulrich Krämer; Heiko Friederichs
Original assignee: Betek GmbH and Co KG
Current assignee: Betek GmbH and Co KG
Priority date: 2016-05-12
Filing date: 2017-04-28
Publication date: 2017-12-27
Anticipated expiration: 2037-04-28
Also published as: KR20200078688A; JP6548747B2; PT3608504T; AU2017245306A1; AU2017245306B2; CA2982108A1; BR122022014393B1; US20200378254A1; US11131188B2; BR112017021807B1; TWI635214B; RU2683440C1; CN107614831A; ES2940057T3; CN107614831B; FI3608504T3; US10738610B2; EP3259447B1; RS64064B1; US20180073359A1

Abstract

The invention relates to a pick, in particular a round-shank pick, comprising a pick head and a pick shaft, comprising a support element which has a seat surface on the lower face and a centering projection that protrudes beyond the seat surface. The centering projection has a centering surface which runs at an angle to the central longitudinal axis of the pick and which transitions directly or indirectly into the seat surface, and the support element is interrupted along the central longitudinal axis by a receiving bore with an internal diameter D for receiving the pick shaft. A collar height, which is measured in the direction of the central longitudinal axis between a centering projection end facing away from the seat surface and the seat surface or between the end of the centering projection and an inner termination of an opening recessed into the support element relative to the seat surface, is designed such that the ratio between the internal diameter D, the receiving bore of the support element, and the collar height is smaller than 8 and/or the collar height is greater than an axial clearance of the pick mounted in a pick holder. The pick is characterized by reduced wear.

Description

Chisel with a support element with a spigot

The invention relates to a chisel, in particular round shank chisel, with a chisel head and a chisel shank, with a support member having on its underside a seat surface and a projecting beyond the seat centering, wherein the centering has a center axis inclined to the center of the chisel extending centering indirectly or passes directly into the seat and wherein the support element is pierced along the central longitudinal axis of a receiving bore having an inner diameter D, for receiving the drill collar.

The invention further relates to a tool system with a chisel, in particular a round head chisel, which has a chisel head and a chisel shaft, with a support element which has on its underside a seat surface and a centering projection projecting beyond the seat surface, wherein the centering lug extends inclined to the central longitudinal axis of the chisel Centering surface which merges directly or indirectly into the seat surface, wherein the support element is pierced along the central longitudinal axis of a receiving bore having an inner diameter D, for receiving the chisel shank, with a chisel holder for receiving the chisel shank, wherein the Chisel holder facing the support member has a wear surface for supporting the seat and a centering receptacle for receiving the spigot of the support element.

Such a bit or such a tool system are known from DE102014104040A1. Starting from a cutting element, the diameter of the chisel head increases towards a collar, which is followed by a chisel shaft. The cylindrically executed chisel shaft is held by means of a clamping sleeve in a chisel holder in a holding approach of a chisel holder. The fixing by means of the clamping sleeve allows a rotation of the bit about its central longitudinal axis, while an axial movement is blocked. Between the chisel head and the retaining lug a support member is arranged, is guided by the central receiving bore of the drill collar. Towards the chisel head, the support element has a recess bordered by an edge, the bottom of which represents a support surface on which the chisel head rests with a bearing surface. Towards the bit holder, the support element forms a seat surface, which merges toward the center of the support element into a centering surface of a centering projection running obliquely to the central longitudinal axis of the bit. In the transition region between the centering surface and the seat surface, a groove is arranged, which has a depth of at least 0.3 mm with respect to the seat surface. The upper side of the retaining lug of the chisel holder is formed to the chisel head corresponding to the underside of the support element. It has a wear surface on which the seat surface of the support element rests. The centering approach of the support element is guided radially in a centering of the holding approach. Due to the wear of the wear surface during operation of the tool assembly with the chisel, a bead is formed on the wear surface of the chisel holder in the region of the groove of the support element, which engages in the groove. By this engagement, an additional lateral guidance of the support element is achieved. At the same time, the penetration of waste material into the area of the bit receptacle is at least reduced by the groove and the bead engaging therein, as a result of which the rotatability of the bit is preserved and wear is reduced. In order to ensure the rotation of the bit about its central longitudinal axis, an axial play of the bit in the bit holder is desired. It is intended for larger chisel a larger game than for smaller chisel. If the axial clearance exceeds the height of the centering shoulder, then the lateral guidance of the support element is lost by the centering shoulder. This leads to increased wear of both the support member and the chisel holder.

From DE 60209235 T2 a disc for a rotary cutting bit is known. The disc has a plurality of ribs on its front facing the bit head. These may have a curved shape and be distributed uniformly over the circumference of the disc. On the opposite back evenly distributed recesses may be formed in the disc. Towards a central receiving bore of the disk, the rear side has a centering projection with a bevelled edge extending inclined to the central longitudinal axis of the disk. This protrudes when mounted disc in a corresponding chamfer, which is arranged circumferentially to a bit holder of a chisel holder, resulting in a lateral guidance of the disc. By the ribs and recesses, the support surface of the disc is reduced, resulting in an improved rotation of the disc.

Also in this arrangement, due to the permissible axial clearance of the assembled bit, the lateral guidance of the disc can be lost by the centering approach with the chisel raised at maximum, thereby significantly increasing the wear of the disc itself and the chisel holder. In particular, a wobbling movement of the disc thus enabled can lead to uneven wear of the end face of the chisel holder, as a result of which it chamfers and thus wears out more quickly. Furthermore, in a tapered worn end side, the rotatability of the bit can be restricted or blocked, which leads to a one-sided and rapid wear of the bit. The radially oriented ribs and recesses lead to no additional lateral guidance of the disc. It is therefore an object of the invention to provide a bit with an improved wear behavior. It is a further object of the invention to provide a tooling system with such a bit.

The chisel-related object of the invention is achieved in that a measured in the direction of the central longitudinal axis between one of the seat bottom end of the spigot and the seat surface or between the end of the spigot and an inner end of a recessed relative to the seat in the support member molded recess height collar is designed such that the ratio between the inner diameter D, the receiving bore of the support member and the collar height is less than 8 and / or that the collar height is greater than an axial clearance of the mounted in a bit holder chisel. Mounted on a chisel holder, the seat surface of the support element lies on a wear surface of the chisel holder. In this case, the centering lug engages in a formed in the wear surface centering and thus leads to a radial stabilization of the positions of the support element. If a recess formed in the seat, so engages a neck of the chisel holder in this. By a ratio smaller than 8 between the inner diameter D, the receiving bore of the support member and the collar height sufficient locking of a lateral movement of the support member is ensured. Preferably, the collar height is greater than the expected over the life expectancy of the chisel selected maximum axial play. The centering approach thus leads to a lateral stabilization of the support element even when in the axial play maximally extracted from the bit holder chisel. As a result, the wear of the support element and the wear surface of the chisel holder can be significantly reduced. This is especially true at an uneven axial load of the support element. Such an uneven axial load results in insufficient lateral stabilization of the support element to an asymmetric and thus increased wear of the wear surface of the holder. Due to the improved lateral guidance of the support element according to the invention, a more accurate centering of the guided in the receiving bore of the support member bit, whereby an asymmetric wear of the wear surface is avoided or at least reduced. The low wear of the support element and the wear surface as well as the improved centering of the bit stabilizes the rotational movement of the bit. This causes a more uniform wear and thus an increase in the service life of the bit. The centering approach leads in cooperation with the centering to a labyrinth-like seal. As a result, the penetration of space material and dust into the area of the bit holder and the bit shank is at least reduced. Due to the selected ratio of less than 8 between the inner diameter D, the receiving bore of the support member and the collar height, a sufficient seal is ensured so that no or only a few foreign substances reach the area of the bit holder and the chisel shank and block the rotational movement of the chisel. This reduces the wear of the bit.

Preferably, it can be provided that the ratio between the inner diameter D, the receiving bore and the collar height is less than 7.5, preferably less than 7.0, more preferably less than 6.5. At a ratio smaller than 7.5, a good lateral guidance is achieved even with directly acting on the support element lateral forces, for example by abschlagendes space material. By a ratio of less than 7.0, the lateral guidance is again improved, so that the simultaneous action of axially aligned, unevenly distributed over the support member forces and radial-acting transverse forces does not lead to a wobbling motion of the support element with a high wear caused thereby. At a ratio of less than 6.5 sufficient lateral guidance is also achieved towards the end of the service life of the support member and the chisel, if the axial play of the chisel is optionally increased by the already occurring wear.

A radially acting guide of the support element and thus of the chisel with at the same time good rotatability of the support element and the chisel can be achieved in that the centering lug and / or the recess are arranged circumferentially to the receiving bore. The lateral guidance of the support element can be further improved in that a plurality of recesses of the same or different depth or at least one spiral extending around the spigot recess are formed in the seat and that the ratio between the inner diameter D, the receiving bore of the support member and the collar height to a the recesses or the grooves of the spiral recess, preferably the ratio between the inner diameter D, the receiving bore and the largest to a recess or a groove determined collar height is less than 8. By several radially juxtaposed recesses and corresponding thereto and engaging in the recesses approaches of the chisel holder, the projected area is maintained in the axial direction, the contact surface between the bit holder and the support member in the radial direction is, however, increased. As a result, larger lateral forces can be absorbed. At the same time, the contact surface between the bit holder and the support element is increased, whereby the surface pressure and consequently also the wear is reduced. By the adjacent recesses and engaging therein approaches the sealing effect against penetrating space material is also significantly improved. Due to the ratio of smaller 8 between the inner diameter D, the receiving bore of the support member and the collar height a sufficient radial guidance of the support element and thus the chisel is achieved even in the context of the axial clearance maximum of the wear surface lifted support member.

A further improvement of the lateral guidance and the sealing and thus the rotatability and the wear of the bit can be achieved in that a guide web projects at a distance from the centering projection over the adjacent seat surface. The guide web advantageously engages in a recessed into the wear surface of the chisel holder and corresponding to the guide web bridge recording.

The spigot is advantageously received in a molded into the bit holder centering and rotatably mounted therein. The integrally formed on the seat surface of the support member guide bar then grinds during the Operation of the chisel in the just running wear surface of the chisel holder. In order to achieve a sufficient lateral guidance of the support element before the guide web has ground a web recording in the bit holder, it may be provided that the recess between the spigot and the guide web is formed and that the spigot over the adjacent seat has a greater height than the guide bar.

An essential prerequisite for a low wear of the bit, the support member and the chisel holder is the easy and free rotation of the support member and the bit about the central longitudinal axis of the bit. The rotation can be improved by transitions between the centering surface, the seat, the recess and / or the guide bar straight or rounded. Sharp and rotation blocking edges are avoided.

A good lateral guidance of the support element can result from the fact that the depth of the recess relative to the seat is greater than or equal to 0.3mm, preferably between 0.3mm and 2mm, more preferably between 0.5mm and 1, 5mm. If the recess chosen smaller than 0.3 mm, there is no sufficiently pronounced approach for a sufficient lateral stabilization of the support element. Recesses to a depth of 2mm give a good sealing effect (labyrinth seal) between the lug and the recess. If the depth of the recess between 0.5mm and 1, 5mm chosen, so there is a good combined effect between sealing and side guide.

For common chisel sizes and associated chisel holder suitable support elements can be obtained in that the support member has a receiving bore with an inner diameter D, of 20mm and the collar height is greater than 2.5mm and / or that the support member has a receiving bore with an inner diameter D, 22mm and the collar height is greater than 2.75mm and / or that the support member has a receiving bore with an inner diameter D, of 25mm and the collar height is greater than 3.125mm and / or that the support member has a receiving bore with a Inner diameter D, of 42mnn and the collar height is greater than 5.25mnn. For smaller chisels, for example for fine milling, support elements with an inner diameter D, the receiving bore of 20mm or 22mm and a collar height of at least 2.5mm or 2.75mm are suitable. For chisels of medium size, support elements with an inner diameter D, the receiving bore 25mm and a collar height of 3.125mm are suitable. For large chisel and associated chisel holder support elements with 42mm inner diameter D, the receiving bore and a collar height of at least 5.25mm can be used. With a ratio of less than 8 between the inner diameters D, the mounting holes of the support elements and the respective collar height correspondingly higher centering lugs are provided for larger support elements. This ensures that there is sufficient lateral guidance of the support elements for larger chisels with correspondingly larger occurring forces and a larger axial play of the chisel.

The object of the invention relating to the tool system is achieved in that a centering height measured in the direction of the central longitudinal axis between one end of the wear surface and the wear surface or between the end of the centering attachment and a maximum point of a projection projecting beyond the wear surface is designed such that the ratio between the inner diameter D, the receiving bore of the support member and the centering height is less than 8 and / or that the collar height is greater than an axial clearance of the bit mounted in a bit holder.

Due to the ratio smaller than 8 between the inner diameter D, the receiving bore of the support member and the centering a good lateral guidance of engaging in the centering centering approach is achieved. If the collar height is greater than the axial clearance of the chisel mounted in the chisel holder, the good lateral guidance is still achieved even if the chisel is pulled out of the chisel holder within its maximum allowable axial play and the support element in the region of the gap thus formed between the chisel head and the chisel holder in the axial direction can. The required centering height is provided correspondingly larger for larger support elements and thus for larger tool systems. As a result, a good lateral guidance of the support element is achieved even with large tool systems with a correspondingly larger allowable axial play of the bit. At the same time, a pronounced, labyrinth-like sealing portion is created by the centering and the engaging therein centering approach of the support element, which makes the penetration of foreign bodies in the field of bit storage at least difficult.

Both the lateral guidance and the sealing effect can be improved in that the supporting element rests with its seating surface on the wear surface of the chisel holder and that at least one projection of the chisel holder projecting beyond the wear surface is designed corresponding to a recess of the support element formed in the seat surface and this protrudes. The approach and correspondingly the recess may be formed throat-shaped or trapezoidal or multi-level in different contour sections.

The lateral guidance and the sealing effect can be further improved by the fact that the support element has a guide web, which projects beyond the adjacent seat surface and that the bit holder has a molded into the wear surface and corresponding to the guide web support receiving, in which projects the guide web. Combinations are also conceivable in which the seat surface of the support element has at least one guide web and at least one recess and the wear surface corresponding thereto has at least one web receptacle and at least one projection.

According to a particularly preferred embodiment of the invention, it can be provided that the approach and / or the bridge recording are attached by a shaping process in the manufacture of the bit holder on the wear surface and that the corresponding recess and / or the corresponding guide web during operation of the Werkzeugsystenns are formed by abrasion of the seat and / or that the recess and / or the guide bar are attached by a shaping process in the production of the support member to the seat and that the corresponding approach and / or the corresponding web recording during operation of the Werkzeugsystenns by abrasion the wear surface are formed. It must be profiled in the production of only one component, namely the bit holder or the support element accordingly. The profiling then grinds during operation in the opposite component. The grinding process can be done over several chisel changes. Advantageously, the harder component is profiled. Particularly preferably, the profiling takes place on the seat surface of the support element. Corresponding lugs and web recordings are then ground during operation in the wear surface of the chisel holder. The Einschieifen takes place advantageously during rotational movements of the support element. In this case, the support element is guided radially by its centering in the centering of the chisel holder.

The invention will be explained in more detail below with reference to an embodiment shown in the drawings. Show it:

1 shows a side view of a tool system with a chisel in its mounting position on a chisel holder

FIG. 2 shows a detail marked II in FIG. 1

Figure 3 shows a schematic representation of the wear of a

Wear surface of a chisel holder in a known

support element

Figure 4 in a sectional side view a detail

Support element in a first embodiment and

Figures 5-14 in schematic side sectional views one each

Section of a support element in other versions. FIG. 1 shows a side view of a tool system according to the prior art with a chisel 10 in its mounting position on a chisel holder 40. The chisel 10 designed as a round shank chisel has a chisel head 13 with a chisel tip 14 made of a hard material, for example hard metal. Opposite the chisel tip 14, a cylindrical centering section 12 is formed on the chisel head 13, which merges via a taper section 12.1 into a cylindrical chisel shaft 11.

The bit holder 40 has a base part 41, to which a lower side projecting tab 42 is formed. The base member 41 also carries a one-piece molded retaining lug 43, in which a bit holder 46 is introduced as a cylindrical bore. In this case, the bit receptacle 46 is designed as a through hole, which is open at its two longitudinal ends. The plug projection 42 facing away from the end of the bit holder 46 opens into a cylindrical portion 44 of the retaining projection 43. On the outer periphery of the retaining projection 43 wear marks 45 are provided in the form of circumferential rings.

The chisel 10 is held on its chisel shank 1 1 by means of a fastening sleeve 20 in the bit holder 46 of the chisel holder 40. The mounting sleeve 20 has for this purpose retaining elements 21 which engage in a circumferential groove 15 of the drill collar 1 1. Furthermore, the fastening sleeve 20 has a clamping slot 23. This makes it possible that the fastening sleeve 20 made of resilient material is pressed due to its residual stress against the wall of the bit holder 46 and so fixed to this. The bit 10 is thus rotatable about its longitudinal axis, but held axially fixed in the bit holder 46. In this case, the axial bearing allows a direction indicated by a double arrow, defined axial play 50 of the bit 10 to allow easy rotation of the bit 10.

Between the chisel head 13 and the chisel holder 40, a disc-shaped support member 30 is arranged, as shown in more detail in Figure 2, wherein the Outer contour of the disc-shaped support member 30 follows a geometric shape and / or an arbitrary shape.

For operation, the bit holder 40 is mounted with its insertion projection 42 in a corresponding holder on a milling drum, not shown, a milling machine. The chisel 10 is fastened by means of the fastening sleeve 20, together with the support element 30, to the holding lug 43 of the chisel holder 40. During operation, the bit 10 is guided by a rotational movement of the milling drum through the space material. In this case, the bit 10 rotates automatically due to acting forces, so that a uniform radial wear of the bit 10 is achieved.

FIG. 2 shows a detail of the tool system marked II in FIG. 1 with a chisel 10 and a support element 30 according to the prior art. The chisel head 13 is completed in the direction of the chisel shank 1 1 with a collar 13.2, which forms a support surface 13.1. This rests on a support surface 32 of the support element 30. The support surface 32 is formed within a receptacle 31 on the top of the support member 30. It is correspondingly limited on the outside by an edge 31 .1. On the opposite side of the support surface 32, the support member 30 has a seat surface 33, with which it rests on a wear surface 47 of the cylindrical portion 44 of the holding lug 43. The support member 30 is constructed substantially rotationally symmetrical to a central longitudinal axis (M) of the bit 10. The seat 33 passes over a circumferential recess 35 in an inclined to the central longitudinal axis M extending centering surface 34.1 of a spigot 34 over. As clearly illustrated in FIG. 2, the centering lug 34 of the support element 30 is inserted into a correspondingly shaped centering receptacle 48 of the chisel holder 40.

Along the central longitudinal axis (M), the support member 30 has a receiving bore 39 through which a guide portion 36 is formed for guiding the bit 10. In the assembly position, the centering portion 12 of the drill collar 1 1 is associated with the guide portion 36. This way arises between the guide portion 36 and the centering 12 a pivot bearing. It is important to ensure that the outer diameter of the cylindrical centering 12 is matched to the inner diameter D, the receiving bore 39 in the guide portion 36 that a free rotation between the support member 30 and the centering 12 is maintained. The play between these two components should be chosen so that the smallest possible lateral offset (transverse to the central longitudinal axis of the bit (10)) is formed. As already shown in FIG. 1, the centering section 12 merges into the cylindrical tool shank 11 after a tapering region 12.

The chisel shaft 1 1 is held by means of the mounting sleeve 20 in the retaining lug 43 of the chisel holder 40. At its upper end, the fastening sleeve 20 has a chamfer 22.

During operation, the bit 10 may rotate about the central longitudinal axis. The free rotation ensures that the bit 10 wears evenly over its entire circumference. In the process, the support element 30 which is loosely placed and held by the centering section 12 of the tool shank 12 also rotates, as a result of which the rotatability of the chisel 10 as a whole is further improved. By the rotation and the high mechanical load of the bit 10 also a wear of the bit holder 40, mainly in the upper portion 44 of the holding lug 43 is carried out by the load, the wear surface 47 is abraded. The present wear of the holding projection 43 can be evaluated via the wear marks 45 shown in FIG.

As a result of the relative movement between the support element 30 and the retaining lug 43, the wear surface 47 of the retaining lug 43, which is flat in the new state, grinds into the recess 35 of the support element 30, as shown in FIG. As a result of a projection 47.1 forming in accordance with the contour of the recess 35, the support element 30 receives an additional lateral guidance, which has a positive effect on the rotatability of the support element 30 and thus of the bit 10. The centering surface 34.1 merges tangentially into the surface of the recess 35, so that no edges hindering rotation are formed. Accordingly, the surface of the recess 35 via a rounding section without sharp edges in the seat 33 via. The recess 35 counteracts with its radially outer surface portion forces acting radially inwardly on the support member 30. Radially outward forces counteract the radially inner surface portion. This reduces the force which must be absorbed by the centering surface 34.1, which leads in this area to a reduced surface pressure and correspondingly to a reduced wear. In addition, this support also counteracts a wobbling movement in the disk plane of the support element 30, which causes a reduction in wear on the bit holder 40. Furthermore, the recess serves with its milled out of the wear surface 47 counterpart as a labyrinthine seal. Abraummaterial, which passes between the seat 33 and the wear surface 47, is prevented by this seal further advancement and thus enters only to a reduced extent in the region of the chisel shank 1. 1

FIG. 3 shows, in a schematic illustration, the wear of the wear surface 47 of the bit holder 40 in a known support element 30 and in the case of an asymmetrical loading of the support element 30. The disk-shaped support element 30 is in the embodiment shown by a flat support surface 32 and an opposite, likewise flat running Seating 33 limited. The centering projection 34 is integrally formed with its centering surface 34.1 circumferentially to the central receiving bore 39 on the seat surface 33. The receiving bore 39 has an inner diameter D, 58. On the side of the support surface 32, the receiving bore 39 has an insertion phase 36.1.

The asymmetric load is represented by two arrows of different lengths, which symbolize a first force 55.1 and a comparatively larger second force 55.2. The asymmetrical introduction of force can be caused for example by the position of the bit holder 40 to the direction of rotation of the milling drum. Such a non-uniform axial load results in a larger lateral movement (radial movement 54) of the support member 30 to an asymmetric wear on the wear surface 47 of the chisel holder 40th Dies is indicated by a relative to a plane perpendicular to the central longitudinal axis M extending plane by a wear angle 56 inclined course of the wear surface 47. The radial movement 54 is made possible with insufficient lateral guidance of the support element 30. As a result of such asymmetrical wear of the wear surface 47, the chisel 10 leading support element 30 is inclined to the central longitudinal axis M on the wear surface 47. Thus, the receiving bore 39 is not aligned exactly to the central longitudinal axis M of the bit holder 46. By this incorrect position, the smooth rotation of the chisel 10 can be hindered or prevented.

FIG. 4 shows a side sectional view of a detail of a support element 30 according to the invention in a first embodiment.

The support surface 32 is arranged in the receptacle 31 for mounting the chisel head 13. In the opposite seat surface 33, a groove-shaped recess 35 is formed in the support surface 32 in the transition to the centering surface 34.1 of the spigot 34. The recess 35 has a first radius 35.1 in a range between 0.5 mm and 6 mm, in this case of 1, 5 mm. The depth of the recess 35 relative to the seat surface 33 is preferably in a range between 0.3 mm and 2 mm, preferably between 0.5 mm and 1, 5 mm, in this case at 1, 0 mm. The recess 35 merges into the seat surface 33 via a rounded region with a second radius 35. 2. The transition from the recess 35 to the centering surface 34.1 is rectilinear. Thus, edges between the centering 34.1, the recess 35 and the seat 33 are avoided, whereby the free rotation of the mounted support member 30 is improved about the central longitudinal axis M.

A vertex 35.5 forms an inner end 53 of the recess 35. Facing away from the seat surface 33, the centering projection 34 is closed by a web-shaped end 34.2. A collar height 52 is represented by a double arrow. The collar height 52 represents in the present embodiment, measured in the direction of the central longitudinal axis M distance between the end 34.2 of the centering projection 34 and the end 53 of the recess 35. In the embodiment shown, the recess 35 is formed in the seat surface 33 of the support member 30. Mounted, the support element 30 lies with its seat surface 33 on the wear surface 47 of the chisel holder 40 shown in FIG. If the wearing surface 47 is flat until it has passed into the centering receiver 48, the projection 47.1 grinds into the recess 35 during use of the tool system and the support element 30 rotating about the central longitudinal axis M. Alternatively, it can also be provided that the projection 47.1 corresponding to the recess 35 is already formed on the wearing surface 47 during the production of the bit holder 40. In this case, the approach 47.1 already have its final, adapted to the recess 35 contour. It is also possible that the projection 47.1 in the manufacture of the bit holder 40 is adapted only approximately to the contour of the recess 35. The final contour of the projection 47.1 then results during use of the tool system, in which the projection 47.1 einschleift into the recess 35. According to a further possible embodiment, the seat 33 may be executed without molded recess 35. Instead, the projection 47.1 is integrally formed on the wear surface 47 of the bit holder 40. During operation, the projection 47.1 now grinds into the wear surface 33 of the support element 30 and thus forms the recess 35.

An outer diameter 51 of the support member 30 and the inner diameter 58 of the receiving bore 39 of the support member 30 are each marked by an arrow. The outer diameter 51 corresponds in the illustrated embodiment, an outer diameter 57 of the seat 33rd

According to the collar height 52 is designed such that the ratio between the inner diameter 58 of the receiving bore 39 of the support member 30 and the collar height 52 assumes a value less than 8. The collar height 52 is predetermined by the axial dimensioning of the centering projection 34 and the recess 35. At a ratio smaller than 8 between the inner diameter 58 of the receiving bore 39 of the support member 30 and the collar height 52 a good lateral guidance of the support member 30 and thus of the chisel 10 is ensured. In particular, the collar height 52 is designed such that it is greater than the axial play 50 of the bit 10 and thus of the support member 30. The dimensioning of the collar height 52 in response to the inner diameter 58 of the receiving bore 39 of the support member 30 takes into account the larger allowable axial play 52 for larger tool systems. Thus, regardless of the tool size always sufficient lateral guidance of the support member 30 and thus of the chisel 10 is guaranteed.

Due to the voltage applied to the centering 48 centering 34.1 a good radial guidance of the support member 30 is achieved even when within the allowable axial play 50 maximum deflection of the bit 10 from the bit holder 46. Through the recess 35 and the engaging therein projection 47.1 of the bit holder 40, a further lateral guidance of the support member 30 is achieved. Lateral movements or tumbling movements of the support element 30 can be safely avoided. Thereby, the wear of the support member 30 and the chisel holder 40 can be significantly reduced. An asymmetrical wear of the wear surface 47 with an uneven loading of the support member 30, as described for Figure 2, can be avoided or at least significantly minimized. Due to the absence of angular offset of the wear surface 47 as a contact surface of the support member 30 and thus of the bit 10, based on the central longitudinal axis M, a consistently good rotation of the bit 10 and the support member 30 is achieved. An exact lateral guidance of the bit 10 by conditioning its centering portion 12 of the drill shank 1 1 to the guide portion 36 of the support member 30. By the exact lateral guidance of the support member 30 and thus the bit 10 and thus reduced wear of the support member 30 and the chisel holder 40 stabilization of the rotational movement of both the support member 30 and the chisel 10 is achieved. As a result, the wear, in particular of the bit 10 and the chisel head 13 can be reduced. Furthermore, at a ratio smaller than 8 between the inner diameter 58 of the receiving bore 39 of the support member 30 and the collar height 52 an improved sealing effect against penetrating foreign matter by the interlocking contours of the support member 30 and the top of the holding lug 43 of the chisel holder 40 is achieved as in tool systems with a ratio greater than or equal to 8. Thus, for example, less waste material penetrates into the area of the bit receptacle 46, whereby the wear in this area is reduced and the rotatability of the bit 10 is ensured.

The easy rotation of the support member 30 and the chisel 10 is further obtained by the rounded or rectilinear and thus edge-free transitions between the centering surface 34.1, the receptacle 35 and the seat 33. Sharp transitions easily cause the support member 30 to tilt relative to the bit holder 40 and prevent rotation. This can be avoided by the rounded or rectilinear transitions.

FIGS. 5 to 14 each show a section of a support element 30 in further explanations in schematic lateral sectional views.

In the embodiments shown in Figures 5 to 1 1 and 13 and 14, the support members 30 on a flat support surface 32. Alternatively, however, it is in each case possible, according to the embodiment of FIG. 4, to provide a receptacle 31 bordered by an edge 31. 1 on the upper side of the support element 30. The receptacle 31 then forms the support surface 32, on which the chisel head 13 rests with its bearing surface 13.1. At the transition from the support surface 32 in the guide portion 36 an introduction chamfer 36.1 is arranged. Alternatively, the transition may also be rounded.

In the embodiments according to FIGS. 5 to 12, the outer diameter 51 of the support element 30 corresponds to the outer diameter 57 of the respective seat surface 33. In the exemplary embodiments according to FIGS. 13 and 14, a fold 38 is arranged around the seat surface 33. Of the Outer diameter 51 of the support member 30 is correspondingly larger than the outer diameter 57 of the associated seat 33 in these embodiments.

In the exemplary embodiment of a support element 30 shown in FIG. 5, a guide web 37 is arranged on the seat surface 33. The guide web 37 extends at a distance from the centering projection 34. It has a trapezoidal contour with inclined to the seat surface 33 extending side surfaces. Toward the bit holder 40, the guide webs 37 are closed by a seat surface section 33.1. The recess 35 is formed between the centering projection 34 and the guide web 37. It also has a trapezoidal contour. The conclusion 53 of the recess 35 is formed by a contact surface 35.3. In the embodiment shown, the abutment surface 35.3 lies in the same plane as the seat surface 33 laterally of the guide web 37. Towards the central longitudinal axis M, the abutment surface 35.3 merges into the inclined centering surface 34.1 of the centering projection 34. The centering projection 34 is closed by its web-shaped end 34.2 to the bit holder 40 out.

The collar height 52 is measured in the direction of the central longitudinal axis between the end 34.2 of the centering projection 34 and the end 53 of the recess 35, as shown by a double arrow. The ratio between the inner diameter 58 of the receiving bore 39 of the support member 30 and the collar height 52 is less than 8, in the present case less than 6.5, selected. As a result, a good lateral guidance of the support element 30 and a good sealing effect against penetrating foreign substances with the described advantages is achieved. At a ratio of less than 6.5 sufficient lateral guidance is also achieved towards the end of the service life of the support member 30 and the chisel 10, if the axial play 50 of the chisel 10 is optionally increased by the wear already occurred.

It is conceivable to form the collar height 52 on the centering projection 34 with a longitudinal extent, which leads to a ratio between the inner diameter 58 of the receiving bore 39 of the support element 30 and the collar height 52, which is greater than 8. As a result, improved support of the centering surface 34.1 on the inner surface of the bit receptacle 46 and / or an improved support of the outer surface of the collar height 52 can be achieved with the outer surface of the free area of the drill collar.

Mounted the guide bar 37 rests on the wear surface 47 of the chisel holder 40. Due to the rotation of the support element 30, it grinds into the wear surface 47 and thus forms a corresponding web receptacle in the end face of the chisel holder 40. Characterized both the lateral guidance of the support member 30 and the sealing effect is significantly improved.

Notwithstanding the illustrated embodiment, the transition from the centering 34.1 to the contact surface 35.3 and / or the transition from the contact surface 35.3 to the adjacent side surface of the guide web 37 and / or the transition from the opposite side surface of the guide webs 37 to the adjacent seat 33 rounded be. Also, the transitions from the side surfaces to the seat surface portion 33.1 may be rounded. Sharp edges can be avoided. This leads to an improved rotatability of the support element 30.

In the support element 30 shown in FIG. 6, a trapezoidal guide web 37 is likewise arranged on the side of the support element 30 facing the bit holder 40. A formed between the guide bar 37 and the spigot 34 recess 35 has a throat-shaped contour. The radius of the recess 35 is chosen so that its surface merges tangentially into the centering surface 34.1 and the adjacent side surface of the guide web 37. The collar height 52 corresponds to the distance running in the direction of the central longitudinal axis M between the end 34.2 of the centering projection 34 and the apex 35.5 of the throat-shaped recess 35. The combination of the centering projection 34, the recess 35 and the guide web 37 is used in conjunction with a correspondingly shaped wear surface 47 of a chisel holder 40 has achieved a good sealing effect against penetrating material. The seat surface 33 of the support element 30 shown in FIG. 7 passes directly into the centering surface 34. 1 of the centering projection 34. In the outer region of the seat 33, a groove-shaped recess 35 is embedded in the seat 33. The collar height 52 is measured along the central longitudinal axis M between the end 34.2 of the centering projection 34 and the apex 35.5 of the groove-shaped recess 35. The comparatively far outwardly arranged on the support member 30 recess 35 results in a particularly good stabilization of the rotational movement of the support member 30th

FIG. 8 shows a support element 30 with a multi-stage recess 35 and a guide web 37. The centering surface 34.1 extends into the recess 35 and there transitions into a contact surface 35.3 arranged transversely to the central longitudinal axis M, in particular perpendicularly to the central longitudinal axis M. At the contact surface 35.3 joins as a further recess of the recess 35, a groove-shaped portion 35.4. The surface of the groove-shaped region 35.4 merges tangentially into the adjacent side surface of the guide web 37. The trapezoidal shaped guide web 37 forms a seat surface portion 33.1, which is connected via the outer side surface of the guide web 37 with the further seat surface 33. The contact surface 35.3, the seat surface portion 33.1 and the outer seat 33 extend transversely, in particular perpendicular to the central longitudinal axis M. The contact surface 35.3 is further formed in the support member 30 as the seat 33. The collar height 52 is between the end 34.2 of the spigot 34 and the Vertex 35.5 measured as a conclusion 53 of the groove-shaped portion 35.4 of the recess 35.

The different levels in which the support surface 33, the support surface portion 33.1 and the contact surface 35.3 are arranged, lead both to a good lateral guidance of the support member 30 as well as to a good sealing effect.

In the exemplary embodiment of the support element 30 shown in FIG. 9, concentrically arranged recesses 35 are formed around the centering projection 34 in the support element 30. It forms a wave-like contour whose Surface represents the seat 33. By way of derogation, it may also be provided that the recesses 35 are formed by a groove that spirals around the centering shoulder 34. The collar height 52 is measured between the end 34.2 of the centering projection 34 and the vertex 35.5 of the innermost recess 35. For adjacent recesses 35 of different depth, the collar height 52 is preferably determined at the end 53 of the deepest recess 35. By virtue of the recesses 35 arranged circumferentially relative to the centering lug 34, good rotatability of the support element 30 is ensured. Furthermore, the engagement of corresponding lugs 47.1 of the chisel holder 40 leads to a good sealing effect. Due to the wavy contour, the projected in the axial direction surface remains equal to a flat surface, so that the axial support effect is maintained. The radially effective surface is significantly increased by the side edges of the recesses 35. As a result, lateral forces can be better absorbed. The waveform increases the area of contact between the support member 30 and the bit holder 40 shown in FIG. Thereby, the surface pressure between the support member 30 and the bit holder 40 is reduced, resulting in reduced wear and improved rotation.

FIG. 10 shows a support element with a flat seat surface 33, in which two concentric, groove-shaped recesses 35 are incorporated. In this arrangement, a good rotation, good lateral stabilization and a good sealing effect against penetrating space material can be achieved.

The supporting element 30 shown in FIG. 1 1 has a seat 33 extending rectilinearly but oriented obliquely to the central longitudinal axis M. In this case, the maximum recess in the support element 30 is formed in the rounded out transition region of the centering surface 34.1 in the wear surface 33. Both the centering surface 34.1 and the wear surface 33 act by their orientation obliquely to the central longitudinal axis M radially stabilizing to the position of the support member 30. The collar height 52 is from the end 34.2 of Centering approach 34 to the conclusion 53 measured in the transition region from the centering surface 34.1 to the wear surface 33.

In the support element 30 shown in FIG. 12, both the support surface 32 and the seat surface 33 run obliquely to the central longitudinal axis M. The support surface 32 and the seat surface 33 are preferably arranged plane-parallel to one another. The largest measured in the direction of the central longitudinal axis M distance between the end 34.2 of the centering 34 and the seat 33 results to the outer edge of the support member 30, so that this distance forms the collar height 52. In this exemplary embodiment, too, both the centering surface 34. 1 and the seat surface 33 oriented obliquely to the central longitudinal axis M act on the support element 30 in a radially stabilizing manner.

FIG. 13 shows a support element 30 with an outer fold 38. The centering surface 34. 1 of the centering projection 34 merges into the planar support surface 33. The support surface 33 is preferably aligned perpendicular to the central longitudinal axis M. The outer diameter 57 of the seat 33 is selected to be slightly larger than the diameter of the wear surface 47 of the chisel holder 40. Mounted in the embodiment shown rectangular bent portion 38 extends in the direction of the chisel holder 40. Mounted around the upper portion 44 of the retaining lug 43 and thus leads to an additional lateral stabilization of the support member 30. Furthermore, the fold 38 protects the area between the chisel holder 40 and the support member 30 from penetrating material. In order to avoid tilting of the support element 30, the transitions from the centering surface 34.1 into the seat surface 33 or from the seat surface 33 to the fold 38 can be rounded. The collar height 52 is marked as a distance between the end 34.2 of the centering portion 34 and the seat 33 by a double arrow.

Also, Figure 14 shows a support member 30 with a retaining lug 43 of the chisel holder 40 encompassing fold 38. The seat 33 is in this case curved inward. As a result, compared to the embodiment shown in Figure 13 improved lateral guidance as well as a improved rotation around the central longitudinal axis M of the support member 30 achieved. The distance between the end 34.2 of the centering projection 34 and the inner end 53 of the seat 33 corresponds to the collar height 52.

In all embodiments of the invention shown, the respective collar height 52 is greater than the permissible axial play 50 of the bit 10 and thus the support member 30 designed. As a result, sufficient lateral guidance of the support element 30 is achieved even with a maximum deflection of the bit 10 from the bit receptacle 46. Due to the different possible contours of the chisel holder 40 facing side of the support member 30 and the correspondingly designed top of the chisel holder 40, the lateral guide and the seal against penetrating foreign bodies can be adapted to the appropriate requirements. Essential here is the ratio smaller 8 between the inner diameter 58 of the receiving bore 39 of the support member 30 relative to the respective collar height 52, since from this ratio, the radial movement of the support member 30 is blocked so that increased wear, as he by a radial movements of the Support member 30 is caused is excluded.

Experiments by the Applicant have shown that, for example, the formation of a spigot 34, a guide bar 37 and / or a recess 35 with an interrupted contour, for example, as web-like contours or more distributed over the contours individual recesses 35 the Einschleifverhalten a rotating bit on the end face of the holder shaft positively favors. As a result, it should be noted that the ground centering projection 34 forms a so-called labyrinth seal on the end face of the holder shaft, so as to protect the inner bore 39 from undesirable contamination or dirt from the forming cavity between a centering projection 34, a guide bar 37 and / or a recess 35 and the end face of a holder shaft due to an axial displacement of the chisel can be derived specifically. In this case, such interruptions additionally in a radial longitudinal extent different lengths are formed to further improve the discharge of contaminants.

Furthermore, the derivative of the pressure occurring in the holder due to the rotational movement of the bit can be improved.

Claims

claims

1 . Chisel (10), in particular round shank chisel, with a chisel head (13) and a chisel shank (11), with a supporting element (30) having on its underside a seat surface (33) and a centering projection (34) protruding beyond the seat surface (33) ), wherein the centering lug (34) has a centering surface (34.1) inclined to the central longitudinal axis (M) of the chisel (10) which merges directly or indirectly into the seat surface (33) and wherein the support element (30) extends along the central longitudinal axis ( M) of a receiving bore (39) with an inner diameter D, (58) for receiving the drill shank (1 1) is broken,

characterized,

in that, in the direction of the central longitudinal axis (M), an end (34.2) of the centering projection (34) and the seat surface (33) facing away from the seat surface (33) or between the end (34.2) of the centering projection (34) and an inner end (53 ) a collar height (52) which is recessed in relation to the seat surface (33) and recessed into the support element (30) is designed such that the ratio between the inner diameter D, (58) of the receiving bore (39) of the support element (30) and the collar height (52) is less than 8 and / or that the collar height (52) is greater than an axial clearance (50) of the bit (10) mounted in a bit holder (40).

2. chisel (10) according to claim 1,

characterized,

the ratio between the inner diameter D, (58) of the receiving bore (39) and the collar height (52) is less than 7.5, preferably less than 7.0, particularly preferably less than 6.5.

Chisel (10) according to claim 1 or 2,

characterized,

that the centering projection (34) and / or the recess (35) are arranged circumferentially to the receiving bore (39).

A bit (10) according to any one of claims 1 to 3,

characterized,

in that a plurality of recesses (35) of the same or different depth or at least one recess (35) extending spirally around the centering lug (34) are formed in the seating surface (33) and that the ratio between the inner diameter D, (58) of the receiving bore (39) the support element (30) and the collar height (52) to one of the recesses (35) or the grooves of the spiral recess (51), preferably the ratio between the inner diameter D, (58) of the receiving bore (39) and the largest to a recess (35) or a groove determined collar height (52) is less than 8.

A bit (10) according to any one of claims 1 to 4,

characterized,

a guide web (37) projects beyond the adjacent seat surface (33) at a distance from the centering shoulder (34).

Chisel (10) according to claim 5,

characterized,

in that the recess (35) is formed between the centering lug (34) and the guide web (37), and that the centering lug (34) has a greater height than the adjacent web (33) than the guide web (37).

7. bit (10) according to any one of claims 1 to 6,

characterized,

that transitions between the centering surface (34.1), the seat surface (33), the recess (35) and / or the guide web (37) are rectilinear or rounded.

8. chisel (10) according to one of claims 1 to 7,

characterized,

that the depth of the recess (35) relative to the seat surface (33) is greater than or equal to 0.3mm, preferably between 0.3mm and 2mm, more preferably between 0.5mm and 1.5mm.

9. chisel (10) according to one of claims 1 to 8,

characterized,

the support element (30) has a receiving bore (39) with an inner diameter D, (58) of 20 mm and the collar height (52) is greater than 2.5 mm and / or that the support element (30) has a receiving bore (39) with a Inner diameter D, (58) of 22mm and the collar height (52) is greater than 2.75mm and / or that the support element (30) has a receiving bore (39) with an inner diameter D, (58) of 25mm and the collar height ( 52) is greater than 3.125 mm and / or that the support element (30) has a receiving bore (39) with an inner diameter D, (58) of 42 mm and the collar height (52) is greater than 5.25 mm.

10. Tool system with a chisel (10), in particular round shank chisel, which has a chisel head (13) and a chisel shank (11), with a support element (30) which has on its underside a seat surface (33) and one above the seat surface (33). 33) protruding centering lug (34), wherein the centering lug (34) has a center axis (M) of the bit (10) inclined centering surface (34.1) which merges directly or indirectly into the seat surface (33), wherein the support element ( 30) along the central longitudinal axis (M) of a receiving bore (39) having an inner diameter D, (58) for receiving the drill shank (1 1) is broken, with a bit holder (40) for receiving the drill shank (1 1), wherein the bit holder ( 40) the support element (30) facing a wear surface (47) for supporting the seat surface (33) and a centering receptacle (48) for receiving the spigot (34) of the support element (30),

characterized,

in that, in the direction of the central longitudinal axis (M), one end of the centering receptacle (48) and the wear surface (47) facing away from the wear surface (47) or between the end of the centering receptacle (48) and a maximum point of a projection protruding beyond the wear surface (47) (47.1) measured centering height is designed such that the ratio between the inner diameter D, (58) of the receiving bore (39) of the support member (30) and the centering height is less than 8 and / or that the collar height (52) is greater than an axial Play (50) of the bit (10) mounted in a bit holder (40).

1 1. Tool system according to claim 10,

characterized,

in that the support element (30) rests with its seat surface (33) on the wear surface (47) of the chisel holder (40) and that at least one projection (47.1) of the chisel holder (40) projecting beyond the wear surface (47) corresponds to one in the seat surface (33) formed recess (35) of the support member (30) is formed and projects into this.

12. Tool system according to claim 10 or 1 1,

characterized,

in that the support element (30) has a guide web (37) which protrudes beyond the adjacent seat surface (33) and that the tool holder (40) has a molded into the wear surface (47) and to the guide web (37). has corresponding web recording, in which the guide web (37) protrudes.

Tool system according to one of claims 10 to 12,

characterized,

in that the projection (47.1) and / or the web support are attached to the wear surface (47) by a shaping process during production of the tool holder (40) and that the corresponding recess (35) and / or the corresponding guide web (37) during the Operation of the tool system by abrasion of the seat surface (33) are formed and / or that the recess (35) and / or the guide web (37) by a molding process in the manufacture of the support member (30) on the seat surface (33) are mounted and the corresponding projection (47.1) and / or the corresponding web receiver are formed during operation of the tool system by abrasion of the wear surface (47).

Tool system according to one of claims 1 to 13,

characterized,

that the centering projection 34, the guide web 37 and / or the recess 35 has an interrupted contour profile.

Tool system according to one of claims 1 to 14,

characterized in that the interruptions in the contour curve have one or more radial longitudinal extents of different lengths.