Chisel holder

Abstract

The invention relates to a chisel holder (30) for an earth working machine, in particular for a road milling machine, a stabilizer, a recycler, or a surface miner, having a support body (35) which has a chisel receiving area (32) or supports at least one cutting tip in the region of a working side, said support body (35) supporting a plug-in attachment (44) directly or indirectly on a plug-in attachment side. The plug-in attachment (44) has a plug-in attachment longitudinal axis (44.2), said plug-in attachment longitudinal axis (44.2) lying on a central longitudinal plane (ME) of the chisel holder (30), and the support body (35) has two front machined surfaces (41.1, 41.2) which form a machined surface pair, are at an angle to one another so as to form a transverse support angle (α) and at least part of which are provided in front of the plug-in attachment (44). The plug-in attachment (44) has, on its front side, at least one convex front shaft contact surface (45), and a cross-section (SF) through the chisel holder (30), said cross-section running parallel to and at a distance from the central longitudinal plane (ME), intersects one of the two front machined surfaces (41.1, 41.2) of the machined surface pair and the front shaft contact surface (45). According to the invention, in order to improve the process of securing the chisel holder in a lower part, the front cross-sectional edge (SK) of the machined surface (41.1, 41.2) and the front cross-sectional edge (45.3) of the front shaft contact surface (45) of the cross-section (SF) form an undercut angle (γ), said undercut angle (γ) equaling at least 103° and at most 114°.

Description

[0001] Chisel holder

[0002] The invention relates to a chisel holder for a soil cultivation machine, in particular for a road milling machine, a stabilizer, a recycler or a surface miner, with a support body which has a chisel receptacle in the area of ​​a working side or at least carries a cutting tip, wherein the support body indirectly or directly carries a plug socket on a plug socket side, wherein the plug socket has a plug socket longitudinal axis, wherein the plug socket longitudinal axis lies in a central longitudinal plane of the chisel holder, wherein the support body has two front cutting surfaces forming a pair of cutting surfaces, which are angled to each other such that they enclose a transverse support angle and which are arranged at least partially in front of the plug socket, wherein the plug socket has at least one convex front shank contact surface on its front side.and wherein a cutting surface running parallel and at a distance from the central longitudinal plane through the chisel holder intersects one of the two front cutting surfaces of the cutting surface pair and the front shank contact surface.

[0003] In a chisel holder according to the invention, the insertion point is arranged in the area of ​​the underside of the chisel holder. Opposite this, the chisel holder forms its upper side on its machining side. When the chisel holder is used as intended, the front side is located at the front of the chisel holder in the feed direction, and the back side is located at the rear of the chisel holder in the feed direction.

[0004] In a chisel holder according to the invention, its central longitudinal plane can be the plane that encloses the central longitudinal axis of the chisel receptacle and the longitudinal axis of the insertion point. Preferably, the bearing surface formed by the chisel receptacle is perpendicular to the central longitudinal plane. In a chisel holder according to the invention, the central longitudinal plane can preferably form a plane of symmetry of the chisel holder, at least for some areas. This means, in particular, that at least some of the functional surfaces or functional components of the chisel holder described below are designed symmetrically relative to the central longitudinal plane.

[0005] Functional surfaces or functional components here refer to surfaces or components that are essential for the function of the chisel holder and its fixation in the corresponding lower part; these are in particular the functional surfaces and functional components explained in more detail in the following application text:

[0006] - Front and / or rear wear surfaces

[0007] - inclined surfaces

[0008] - front and / or rear stock mounting surface

[0009] - Shaft widening

[0010] - Chisel holder, as well as the associated support section and the bearing surface

[0011] - Screw pressure surface

[0012] - Ejector socket

[0013] - and / or cylinder section

[0014] Particularly advantageous are not only the functional surfaces and functional components formed on the support body, but also the fact that the entire support body is designed symmetrically to the central longitudinal plane.

[0015] It is also preferred that not only the functional surfaces and functional components formed at the plug-in connection, but the entire plug-in connection is symmetrical to the central longitudinal plane.

[0016] The symmetrical design allows for simple manufacturing, for example by forging, and ensures that the tool holders can be interchanged with respect to their mounting position on the milling drum. Furthermore, with regard to the functional surfaces and components exposed during operation, this results in predictable and consistent wear behavior independent of the mounting location. In such tool holders according to the invention, the two front cutting surfaces can be arranged completely or partially on both sides of the central longitudinal plane. Preferably, the two front cutting surfaces each form the same angle with the central longitudinal plane.

[0017] In the case of chisel holders according to the invention, the central longitudinal plane may run in the direction of the feed direction.

[0018] Preferably, the central longitudinal axis of the chisel holder lies in the central longitudinal plane.

[0019] The removal surfaces of the chisel holders according to the invention can be designed as flat surfaces completely or at least partially.

[0020] From EP 2 729 666 A2, a chisel holder is known which has a support body. The support body has a chisel receptacle on its machining side. A round-shank chisel can be inserted into this chisel receptacle. Furthermore, the support body has a projecting socket on its side facing away from the machining side. Front cutting surfaces are provided in the area in front of the socket, and rear cutting surfaces are provided in the area behind the socket. The front and rear cutting surfaces are arranged in pairs at an angle to each other. The front cutting surfaces form a transverse support angle. The rear cutting surfaces are also arranged at a transverse support angle to each other. The chisel holder can be inserted into a socket of a base part with its socket in the direction of the socket's longitudinal axis.The cutting motion is limited by the front and rear cutting surfaces, which abut corresponding surfaces on the lower part. A pressure screw is used to fix the chisel holder in the lower part, acting on a pressure surface of the socket. During operation, unexpectedly high load forces may act on the chisel. These strong load forces occur during exceptional operating events. For example, a chisel may strike a particularly hard object during operation, such as a manhole cover on a road milling machine. Under this load, a strong force component acts against the feed direction, which is transmitted from the chisel holder to the lower part. It is essential to ensure that the chisel holder is securely held in the lower part to prevent damage.

[0021] The object of the invention is to provide a chisel holder of the type mentioned above, which is securely held on a lower part receiving the chisel holder even under heavy loads.

[0022] The object of the invention is achieved by the front cutting edge of the removal surface and the front cutting edge of the front shaft contact surface of the cutting surface running parallel and at a distance from the central longitudinal plane enclosing an undercut angle, wherein this undercut angle is at least 103° and at most 114°.

[0023] The chisel holder rests with its front shank contact surface against a corresponding mating surface on the base. Due to the angle of the shank contact surface relative to the front cutting surface(s) at the undercut angle, a positive-locking connection is created between the shank contact surface and the corresponding mating surface of the base. This positive locking action acts in the direction of the longitudinal axis of the plug-in end, opposite to the assembly direction. In the event of an overload, this positive-locking connection prevents the plug-in end from moving out of the socket in the base. Thus, the chisel shank remains securely fixed, and significantly higher loads can be transmitted in the event of an overload.

[0024] According to one embodiment of the invention, the front shank contact surface forms a partially cylindrical surface, and the contact cylinder axis of the partially cylindrical surface of the front shank contact surface and the longitudinal axis of the plug-in attachment form an angle that opens towards the free end of the plug-in attachment. This arrangement results in a particularly stable, positive-locking fixation of the chisel holder with undercut in the lower part. Preferably, the contact cylinder axis of the partially cylindrical surface of the front shank contact surface and the longitudinal axis of the plug-in attachment lie in the central longitudinal plane.

[0025] The partially cylindrical surface does not necessarily have to strictly adhere to a cylindrical shape in the geometric sense. If the chisel holder is, for example, a forged part, then the cylindrical shape can deviate from the strict geometric form within the scope of manufacturing tolerances and / or exhibit burrs resulting from the forging process.

[0026] In particular, it may be provided that the longitudinal axis of the plug-in connection and the contact cylinder axis of the partially cylindrical outer surface of the front shaft contact surface run in the central longitudinal plane in order to enable the most uniform load distribution possible.

[0027] It has been shown that, particularly in the application area for road milling machines, the axial angle between the contact cylinder axis of the partially cylindrical outer surface of the front shaft contact surface and the plug-in longitudinal axis in the range between 2° and 10° is suitable to ensure secure fastening of the chisel holder in the event of overload.

[0028] One possible embodiment of the invention is such that the plug-in connector has a screw receptacle with a flat screw pressure surface on its rear side, opposite the front shaft contact surface, and that the screw pressure surface and the front cut edge of the front shaft contact surface in the cut surface and / or the screw pressure surface and the contact cylinder axis enclose an acute pressure angle with each other, the pressure angle preferably being selected in the range between 30° and 45°. In this way, a sufficiently high clamping force is transmitted between the shaft contact surface and the associated mating surface of the lower part to secure the positive locking connection. Furthermore, this pressure angle also generates a sufficiently high pull-in force in the direction of the plug-in connector's longitudinal axis. This allows the front wear surfaces to be pressed against opposing front support surfaces of the lower part with high clamping force.

[0029] In conjunction with the undercut angle described above between the front shank contact surface and the front cutting surfaces (or the longitudinal axis of the socket), a less steep arrangement of the screw pressure surface is possible, since, in addition to a purely frictional connection to secure the chisel, as in the prior art, the positive locking created in the longitudinal direction of the socket now also holds the socket in the socket according to the invention. In other words, the angle between the screw pressure surface and the front shank contact surface can be chosen to be larger.

[0030] A particularly preferred embodiment of the invention is such that the socket has a cylindrical section with a front partial cylindrical surface in an area between the support body and the front shank contact surface, and that the cylinder axis of this cylindrical section runs along the longitudinal axis of the socket. It has been shown that the stresses acting in the socket are more evenly distributed in the area of ​​the cylindrical section, thus increasing the overall load-bearing capacity of the chisel holder. In the event of overheating, the cylindrical section acts similarly to a tensile shank.

[0031] One possible embodiment of the invention is such that, alternatively or additionally to the front partial cylinder surface, the cylinder section has a rear partial cylinder surface, which is arranged on the rear side of the plug-in fitting opposite the front partial cylinder surface, and that preferably the front partial cylinder surface and / or the rear partial cylinder surface are arranged in the direction of the longitudinal axis of the plug-in fitting in the area between the pressure surface of the screw receptacle and the support body. An arrangement with a front partial cylinder surface and a rear partial cylinder surface creates a stress-efficient force transmission between the front shaft contact and the support body.The cylinder axes of the front and rear partial cylinder surfaces preferably run parallel to the longitudinal axis of the plug-in connection in the central longitudinal plane, wherein the longitudinal axis of the plug-in connection is preferably equidistant from both cylinder axes, or coincides with the cylinder axis of the front partial cylinder surface, or with the cylinder axis of the rear partial cylinder surface. Particularly preferably, the front and rear partial cylinder surfaces share a common cylinder axis that is identical to the longitudinal axis of the plug-in connection.

[0032] A chisel holder according to the invention can, for example, be designed such that a shank extension is arranged in the area between the front shank contact surface and the support body, which transitions the plug-in end into the support body, and that the shank extension widens the cross-section of the plug-in end at least partially in the direction towards the support body and radially to the longitudinal axis of the plug-in end. Preferably, the shank extension extends at least partially in the area of ​​the front of the plug-in end, and preferably the shank extension is continuous. The shank extension increases the cross-section of the plug-in end in the front area. Particularly high stresses occur here in the case of overload. Thus, this measure contributes to reducing the stresses in the transition area between the plug-in end and the support body.If the shaft widening extends all the way around, the lateral stability of the chisel holder is also increased to a significant degree, without resulting in a substantial increase in installation space.

[0033] Advantageously, the shaft widening is arranged in the area of ​​the front of the plug-in connection between the support body and the cylinder section.

[0034] Another embodiment of the invention provides for a rear shank contact surface on the rear side of the plug-in attachment opposite the front shank contact surface, preferably in the transition area of ​​the plug-in attachment into the support body, i.e., in the end region opposite the free end of the plug-in attachment. The rear shank contact surface can have two lateral contact surfaces angled towards each other, preferably with an angle between 45° and 100°, preferably between 50° and 90°, and most preferably between 66° and 76°. The rear shank contact surface serves to transfer forces introduced into the chisel holder into the lower part in the event of overload. Preferably, under normal operating conditions, the rear shank contact surface does not, or only partially, bear against the lower part.In the event of overload, these side contact surfaces press against the lower part due to elastic deformation of the chisel holder. This provides additional support that counteracts the deformation of the chisel holder. The side contact surfaces are preferably angled relative to each other so that they at least hinder rotation of the socket around its longitudinal axis within the socket. An angle between 45° and 100° prevents a non-self-releasing clamping mechanism from forming between the rear shank and the lower part in the event of overload. Furthermore, these angled side contact surfaces, in combination with corresponding mating surfaces on the lower part, form a wedge-like structure that, in the event of overload, leads to a reversible elastic deformation of the lower part, thus dissipating the stresses.It has been shown that this spring effect is particularly advantageous when the side contact surfaces are angled between 50° and 90°. An angle between 66° and 76° is especially suitable for use with road milling machines. The aforementioned shank widening results in a particularly robust design of the chisel holder in the transition area between the socket and the support body. Especially in the event of an overrun, the forces can be absorbed and reliably transferred to the lower part.

[0035] If the side mounting surfaces are at an angle between 45° and 100° to each other, they are particularly suitable for transferring the forces into the transition area.

[0036] Particularly in the case of chisel holders where two flat rear cutting surfaces are provided that are angled to each other, the effects mentioned above are especially advantageous if the side contact surfaces are angled in the range between 30° and 75° (high component strength; self-releasing clamping in case of overload), 35° to 70° (spring effect) or 45° to 55° (road milling machine).

[0037] Particularly in the case of chisel holders where a flat rear cutting surface is provided, or where two flat rear cutting surfaces are provided that are parallel to each other, especially aligned with each other, the effects mentioned above are particularly advantageous if the side contact surfaces are angled in the range between 37° and 87° (high component strength; self-releasing clamping in case of overload), 42° to 82° (spring effect) or 57° to 67° (road milling machine).

[0038] Space optimization results when it is planned that the rear stock assembly is formed at least partially by the stock widening.

[0039] Preferably, the side contact surfaces are each assigned to one side of the tool holder, and the angle enclosed between the side contact surfaces opens towards the front of the tool holder. Preferably, one side contact surface extends completely or partially to one side of the central longitudinal plane, and the other side contact surface extends completely or partially to the opposite side of the central longitudinal plane. It has been shown that, in the case of overload, effective stress relief occurs when the angle between the side contact surfaces opens in the feed direction, i.e., towards the front of the tool holder.

[0040] One possible embodiment of the invention involves connecting the side contact surfaces indirectly or directly to one another via an overload contact surface. This overload contact surface provides an additional support point in the event of an overload. Specifically, in the event of an overload, the side contact surfaces may initially be available to transfer the force from the chisel holder to the lower part. If the deformation of the chisel holder is particularly pronounced, the overload contact surface also comes into contact with the lower part. The overload contact surface thus creates a boundary to limit excessive stress and deformation of the lower part in the area of ​​the side contact surfaces.

[0041] By positioning the overload contact surface on the shaft extension, a larger transmission area can be achieved to dissipate forces in the event of an overload. This reduces the surface pressures and results in lower overall stresses in the larger cross-section of the shaft extension.

[0042] This more robust design is particularly suitable in conjunction with the undercut fixing of the plug-in end in the socket described above. This stable fastening of the plug-in end in the socket now generates significantly higher forces in the transition area between the plug-in end and the support body of the chisel holder.

[0043] An alternative to the invention provides that the support body has at least one rear cutting surface, wherein the at least one rear cutting surface is arranged at least partially behind the plug-in end in the feed direction, and wherein it is preferably provided that the at least one rear cutting surface is at an angle to the front cutting surfaces.

[0044] The object of the invention is also achieved with a chisel holder for a soil cultivation machine, in particular for a road milling machine, a stabilizer, a recycler, or a surface miner, with a support body which has a chisel receptacle in the area of ​​a working side or at least carries a cutting tip, wherein the support body indirectly or directly carries a plug socket on a plug socket side, wherein the plug socket has a plug socket longitudinal axis, wherein the plug socket longitudinal axis lies in a central longitudinal plane of the chisel holder, and wherein the plug socket has at least one convex front shank contact surface on its front side.In this context, it may be specifically provided that the front shank contact surface forms a partially cylindrical surface, and that the contact axis of the partially cylindrical surface and the longitudinal axis of the socket enclose an angle that opens towards the free end of the socket. With such a chisel holder, one or more of the following listed measures may be implemented.

[0045] M1 Chisel holder, characterized in that the plug-in longitudinal axis (44.2) of the plug-in extension (44) and the contact cylinder axis (Z) of the partially cylindrical outer surface of the front shank contact surface (45) run in the central longitudinal plane (ME).

[0046] M2 chisel holder according to measure M1, characterized in that the axis angle (cp) between the contact cylinder axis (Z) of the partially cylindrical outer surface of the front shank contact surface (45) and the plug-in longitudinal axis (44.2) is in the range between 2° and 10°.

[0047] M3 chisel holder according to one of the measures M1 or M2, characterized in that the plug-in extension (44) opposite the front shank contact surface (45) has a screw receptacle (47) with a flat screw pressure surface (47.1) on its rear side, and that the screw pressure surface (47.1) and the front cutting edge (45.3) of the front shank contact surface (45) in the cutting surface (SF) and / or the screw pressure surface (47.1) and the contact cylinder axis (Z) enclose a pressure angle (o) with each other, wherein the pressure angle (o) is selected in the range between 30° and 45°.

[0048] M4 chisel holder according to one of measures M1 to M3, characterized in that the plug-in extension (44) has a cylindrical section (44.5) with a front partial cylindrical surface (44.3) in an area between the support body (35) and the front shank contact surface (45), and that the cylinder axis of this cylindrical section (44.5) runs along the longitudinal axis (44.2) of the plug-in extension.

[0049] M5 chisel holder according to measure M4, characterized in that the cylinder section has a rear partial cylinder surface (44.4) which is arranged on the rear side of the plug-in extension (44) opposite the front partial cylinder surface (44.3) and that preferably the front partial cylinder surface (44.3) and the rear partial cylinder surface (44.4) are arranged in the direction of the plug-in extension longitudinal axis (44.2) in the area between the pressure surface (47.1) of the screw receptacle (47) and the support body (35).

[0050] M6 chisel holder according to one of measures M1 to M5, characterized in that a shank widening (44.1 ) is arranged in the area between the front shank contact surface (45) and the support body (35), which transitions the plug-in extension (44) into the support body (35), that the shank widening (44.1 ) widens the cross-section of the plug-in extension (44) in the direction towards the support body (35) and radially to the plug-in extension longitudinal axis (44.2), that the shank widening (44.1 ) extends at least partially in the area of ​​the front of the plug-in extension (44), and that the shank widening (44.1 ) is preferably formed circumferentially.

[0051] M7 chisel holder according to measure M6, characterized in that the plug extension widening (44.1 ) is arranged in the area of ​​the front of the plug extension (44) between the support body (35) and the cylinder section (44.5).

[0052] M8 chisel holder according to one of measures M1 to M7, characterized in that a rear shank support (48) is arranged on the rear side of the plug-in extension (44) opposite the front shank support surface (45), which has two side support surfaces (48.1 ) angled to each other, wherein it is preferably provided that the angle between the side support surfaces (48.1 ) is selected in the range between 45° and 100°, preferably between 50° and 90°, particularly preferably between 66° and 76°.

[0053] M9 chisel holder according to measures M8, characterized in that the rear shank base (48) is formed at least partially by the shank widening (44.1 ).

[0054] M10 Chisel holder according to one of measures M8 or M9, characterized in that the side contact surfaces (48.1) are each assigned to one side of the chisel holder (30) and that the angle enclosed between the side contact surfaces (48.1) opens towards the front of the chisel holder (30). M1 1 Chisel holder according to one of measures M8 to M10, characterized in that the side contact surfaces (48.1) are connected to each other directly or indirectly via an overload contact surface (48.2).

[0055] M12 chisel holder according to one of measures M1 to M11, characterized in that the support body (35) has at least one rear cutting surface (43.1 , 43.2), wherein the at least one rear cutting surface (43.1 , 43.2) is arranged at least partially behind the plug-in extension (44) in the feed direction (V), and wherein it is preferably provided that the at least one rear cutting surface (43.1 , 43.2) is at an angle to the front cutting surfaces (41.1 , 41.2).

[0056] In the chisel holders according to the invention, or in those described above, the front shank contact surface may also have a convex, in particular a partially cylindrical, shape, and preferably, the front shank contact surface forms two sub-surfaces spaced apart from each other by a groove, the groove extending in the direction of the longitudinal extension of the plug-in end. A wide support distance in the circumferential direction of the plug-in end is achieved via the two spaced-apart sub-surfaces. Furthermore, an anti-rotation device, which is installed in the lower part, can engage in the groove formed between the two sub-surfaces. This ensures the correct orientation of the plug-in end in the plug-in receptacle during normal operation.

[0057] According to one embodiment of the invention, at least one side contact surface of the rear shank contact can form a rear cutting edge in the cut surface, the rear cutting edge and / or the overload contact surface of the rear shank contact can run parallel to the longitudinal axis of the plug-in connection and / or parallel to the contact cylinder axis, or the rear cutting edge and / or the overload contact surface can run at an angle to the longitudinal axis of the plug-in connection and / or at an angle to the contact cylinder axis, preferably with an angle of less than 5°. Such chisel holder designs result in particularly good overload resistance, as the chisel holder remains reliably clamped in the lower part in which it is mounted, even under overload conditions.

[0058] The object of the invention is also achieved with a tool system comprising a chisel holder and a lower part, wherein the lower part has a plug-in receptacle, wherein the chisel holder is mounted in the plug-in receptacle with a plug-in extension, wherein the lower part has support surfaces on which the chisel holder is supported with cutting surfaces of a support body, that the plug-in extension rests at the front in the feed direction with a front shank contact surface against a front shank support surface of the plug-in receptacle, that a pressure screw acts on the opposite rear of the shank, pressing the shank contact surface against the front shank support surface.To ensure the secure fixation of the plug-in end in the plug-in receptacle of the lower part in the event of overload, a positive locking connection is provided between the shank support surface and the front shank contact surface, acting in the direction of the plug-in end longitudinal axis, which blocks any displacement of the chisel holder relative to the lower part in the direction out of the plug-in receptacle.

[0059] The invention will be explained in more detail below with reference to an embodiment illustrated in the drawings. The drawings show:

[0060] Figure 1 shows a tool system with a lower part and a chisel holder in side view.

[0061] Figure 2 shows the tool system according to Figure 1 in a perspective view from behind,

[0062] Figure 3 shows the tool system according to Figures 1 and 2 in the side view opposite Figure 1,

[0063] Figure 4 shows the tool system according to Figures 1-3 in a perspective view from the front, Figure 5 shows a chisel holder in a perspective front view,

[0064] Figure 6 shows the chisel holder according to Figure 5 in combination with a pressure screw and in a perspective side view,

[0065] Figure 7 shows the chisel holder according to Figures 5 and 6 in a perspective view from below,

[0066] Figure 8 shows the chisel holder according to Figures 5-7 in a sectional view,

[0067] Figure 9 shows the chisel holder according to Figures 5-8 in longitudinal section along its central longitudinal plane,

[0068] Figure 10 shows the lower part of the tool system according to Figures 1-4 in a perspective side view,

[0069] Figure 11 shows the lower part according to Figure 10 in a perspective view from behind,

[0070] Figure 12 shows the tool system according to Figures 1-4 in longitudinal section,

[0071] Figure 13 shows the tool system according to Figures 1-4 along the line shown in Figure 3 with

[0072] shown section path from XLIII to XLIII,

[0073] Figure 14 shows another representation of the chisel holder according to Figures 5-9 in a view from below and

[0074] Figure 15 shows a section along the section line marked XV-XV in Figure 6, which runs perpendicular to the longitudinal axis of the plug insertion.

[0075] Figure 1 shows a tool system with a lower part 10 and a tool holder 30 attached to it. The lower part 10 has a connection side 11, which may have a contact surface, preferably concave. By means of this connection side 11, the lower part 10 can be placed on the convex outer surface of a (not shown) milling drum tube and suitably attached to it, for example by means of a weld.

[0076] The lower part 10 may be provided with lateral recesses 12 in the transition area to the connection side 11. These recesses 12 can be used to receive welding material to form a tack weld.

[0077] The base body 13 of the lower part 10 forms the lower connection side 11. This base body 13 has a front face 13.1 facing forward in the feed direction V and a rear face 13.2 facing backward in the feed direction V. The lower part 10 is bounded laterally by side surfaces. The feed direction V runs from left to right in Figure 1. This feed direction V results from the intended use of the tool holder 30 or the tool system.

[0078] It may be provided that at least one paragraph 13.3 is present in the area of ​​at least one of the side surfaces in order to form a material drainage area.

[0079] As shown in Figure 10, the lower part 10 may have a retaining receptacle 14. The retaining receptacle 14 has front support surfaces 15.1, 15.2, which are arranged at least partially in front of a plug-in receptacle 18. The plug-in receptacle 18 may be formed as a through-hole or as a recess in the base body 13 of the lower part 10.

[0080] Preferably, a recess 15.3 is arranged between the two front support surfaces 15.1, 15.2 in the area in front of the plug receptacle 18. The two front support surfaces 15.1, 15.2 are arranged at an angle to each other, as can be seen particularly in Figure 11. This angle opens towards the top of the lower part 10. Furthermore, the lower part 10 may have at least one rear support surface 16.1, 16.2 in its area facing the rear side 13.2. In the present embodiment, two rear support surfaces 16.1, 16.2 are used. The rear support surfaces 16.1, 16.2 are aligned with each other, so that they are arranged on the same plane. However, it is also conceivable that the two rear support surfaces 16.1, 16.2 are at an angle to each other, preferably forming an obtuse angle.

[0081] The two rear support surfaces 16.1, 16.2 are each formed by support sections 19.3. The support sections 19.3 may form parts of a projection 19.2. Preferably, the two projections 19.2, each forming a support section 19.3, are spaced apart from each other transversely to the feed direction V.

[0082] Figure 10 illustrates that the two rear support surfaces 16.1, 16.2 can also be connected to each other by a transition section 16.3. The transition section 16.3 can then also be used to support the chisel holder 30.

[0083] As shown in Figure 10, a front support surface 15.1, 15.2 transitions into a rear support surface 16.1, 16.2 on both sides of the lower part 10. Advantageously, recesses 17, which can be groove-like, are provided between the front support surfaces 15.1, 15.2 and the associated rear support surfaces 16.1, 16.2. Thus, the front support surfaces 15.1, 15.2 are spatially separated from the rear support surfaces 16.1, 16.2 to form defined support areas.

[0084] Figure 10 shows that the socket 18 can be equipped with an insertion extension 18.1 at its upper end. This insertion extension serves to facilitate the insertion of a plug-in end 44 of the chisel holder 30 (see Figure 5).

[0085] An overload support area 18.4 can be provided in the area of ​​the plug receptacle 18. This overload support area 18.4 preferably has two clamping surfaces 18.5, 18.6, which are arranged at an angle to each other. The two laterally arranged clamping surfaces 18.5, 18.6 can be connected by means of a locking surface 18.7. The locking surface 18.7 also extends at an angle to the clamping surfaces 18.5, 18.6. Preferably, each clamping surface 18.5, 18.6 forms the same angle with the locking surface 18.7, which is preferably obtuse.

[0086] With the chisel holder 30 mounted, at least a part of the functional surfaces and functional sections of the lower part 10, in particular the clamping surfaces 18.5, 18.6, the front support surfaces 15.1 15.2, the rear support surfaces 16.1 , 16.2, the insertion extension 18.1 and / or the shank support surface 18.2 described below, can be arranged symmetrically to a central longitudinal plane ME of the chisel holder 30.

[0087] Preferably, the overload support area 18.4 with its clamping surfaces 18.5 and 18.6 and the securing surface 18.7 is formed by the insertion extension 18.1, or is arranged in the area of ​​the insertion extension 18.1, in order to achieve a compact design.

[0088] Figures 10 and 11 further show that a front shaft support surface 18.2 facing the front side 13.1 is formed within the socket 18. The front shaft support surface 18.2 may be interrupted by a recess 18.3, so that partial surfaces of the front shaft support surface 18.2 are formed on both sides of the recess 18.3. The recess 18.3 may, in particular, be groove-shaped. The recess 18.3 may extend from the underside, in particular the connection side 11, of the base body 13 in the direction of the longitudinal extent of the socket 18. A shaped element (not shown), in particular a clamping sleeve, a dowel pin, or the like, may be received in the recess 18.3. The shaped element extends partially into the area of ​​the socket 18. This is more clearly visible in Figure 12.

[0089] A screw receptacle 19 is provided on the reverse side of the base body 13 of the lower part 10. A fastening screw, in particular a pressure screw 20, can be screwed into the screw receptacle 19, as shown in Figure 12. Preferably, access to the screw receptacle 19 is protected in the area between the two projections 19.2 (see Figure 2). The screw receptacle 19 can be incorporated into a surface section 19.1 that extends transversely between the two projections 19.2. The projections 19.2 are bounded by boundary surfaces 19.4 facing the screw receptacle 19. This is shown in Figure 11.

[0090] The screw receptacle 19 opens into the area of ​​the plug-in receptacle 18 of the base body 13, as illustrated in Figure 12. Preferably, the base body 13 has a recess 19.5, as shown in Figure 12, adjacent to the opening of the screw receptacle 19. The recess 19.5 forms a receiving area that is set back from the plug-in receptacle 18. This receiving area facilitates the insertion of the chisel holder 30 into the plug-in receptacle 18.

[0091] As illustrated in Fig. 10, the plug receptacle 18 may have, in the insertion direction, i.e. in the direction of the longitudinal extension of the plug receptacle 18 from top to bottom, an at least partially circumferential hollow cylinder section 18.8, either indirectly or directly behind the insertion extension 18.1.

[0092] The screw receptacle 19 may open into the plug receptacle 18 at its rear. The front shaft support surface 18.2 is preferably arranged in the plug receptacle 19 opposite the opening of the screw receptacle 19.

[0093] The hollow cylinder section 18.8 is arranged in the insertion direction between the insertion extension 18.1 and the mouth area of ​​the screw receptacle 19 and / or between the front shaft support surface(s) 18.2 and the insertion extension 18.1.

[0094] Figures 5 to 8 illustrate the construction of the chisel holder 30. As these illustrations show, the chisel holder 30 has a support body 35. As described below, the support body 35 has a chisel receptacle 32 with a central longitudinal axis M on the machining side and a socket 44 with a socket longitudinal axis 44.2 on an opposite socket end. As shown in the exemplary embodiment, the central longitudinal axis M and the socket axis 44.2 define the central longitudinal plane ME of the chisel holder 30.

[0095] A support section 33 is integrally formed on the support body 35 in the area of ​​one machining side. This support section 33 is preferably designed as a projection or may have a projection. The support section 33 forms at least part of the tool holder 32. Preferably, the tool holder 32 is designed as a bore and has the central longitudinal axis M. The central longitudinal axis M of the tool holder 32 is clearly visible in the longitudinal section shown in Figure 9. Alternatively, a cutting tip MS can also be provided on the support body 35 on the machining side, in particular attached directly or indirectly. This is symbolically represented as an alternative with a dashed line in Figure 6.

[0096] At its free end, the support section 33 forms a bearing surface 31, which preferably extends radially to the central longitudinal axis M of the chisel holder 32. The bearing surface 31 is particularly preferably continuous.

[0097] The support surface 31 serves to support a wear-resistant disc of a (not shown) round-shank chisel. Such a round-shank chisel is inserted with its chisel shank into the chisel holder 32 of the chisel holder 30. The wear-resistant disc is arranged between the support surface 31 and a head of the round-shank chisel and is freely rotatable about the central longitudinal axis M of the chisel holder 32.

[0098] A centner's projection 31.1 can be formed in the area of ​​the bearing surface 31. This centner's projection 31.1 can, for example, be designed as a circumferential bead. The centner's projection 31.1 serves to center the wear-protection disc described above on the bearing surface 31. For this purpose, the wear-protection disc can be provided with a circumferential groove on its underside, on the side facing the bearing surface 31. The centner's projection 31.1 engages in this circumferential groove, while the underside of the wear-protection disc rests on the bearing surface 31.

[0099] The support section 33 can be designed with one or more wear markings 33.1. If several wear markings 33.1 are used, they are preferably spaced apart from each other in the direction of the central longitudinal axis M of the chisel holder 32, as can be seen in Figure 5. The wear markings 33.1 can, for example, be designed as grooves that are at least partially circumferential. This is also shown in Figure 5.

[0100] The support section 33 is connected to the support body 35 via a transition section 34. Preferably, the transition section 34 widens the support section 33 in the direction of the support body 35, at least in some areas.

[0101] The support body 35 may have a skirt 35.1 on its front side, which is arranged at least partially in front of the support section 33. The skirt 35.1 may be equipped with recesses 35.2 to enable improved material transport and thus better wear resistance of the chisel holder 30.

[0102] For improved stiffness, the support section 33 may be coupled to the support body 35 by means of stiffening struts 35.3. The stiffening struts 35.3 can extend to both sides and / or along the rear side of the support section 33, as shown in Figures 4 and 6.

[0103] The chisel holder 30 is bounded by side surfaces 35.4 in the area of ​​its sides, which extend from its front to its rear. The side surfaces 35.4 preferably have frontal chamfers 35.5 to taper the apron 35.1 in an arrow-like shape at the front. This improves material removal during operation. At the front, the support body 35 has a front piece 35.6, which preferably borders the apron 35.1 at the front.

[0104] As shown in Figure 7, the chisel holder 30 may have an ejector receptacle 36 on its rear side. The ejector receptacle 36 preferably has two functions.

[0105] Firstly, the ejector receptacle 36 serves to hold an ejector tool, which provides access to the chisel receptacle 32. Using the ejector tool, a chisel held in the chisel receptacle 32 can then be driven out in the direction of the central longitudinal axis M of the chisel receptacle 32.

[0106] The second function of the ejector receptacle 36 is to remove debris material that has accumulated in the area of ​​the chisel receptacle 32 during operation. This debris material is conveyed radially outwards through the ejector receptacle 36.

[0107] As further illustrated in Figure 7, the ejector receptacle 36 is bounded by two side surfaces 36.1. Alternatively, the ejector receptacle 36 may be bounded on its top side by a cover section 36.3. Preferably, the ejector receptacle 36 is bounded by both side surfaces 36.1 and by the cover section 36.3. The side surfaces 36.1 may transition into the cover section 36.3 by means of a rounded transition. Preferably, the rounded transition is formed by a radius between 2 mm and 8 mm to reduce the risk of contamination accumulation.

[0108] Preferably, the deck section 36.3 is arranged parallel to the support surface 31 to achieve improved discharge efficiency. This is illustrated in Figure 9.

[0109] The side surfaces 36.1 of the ejector receptacle 36 can transition into the contour of the chisel receptacle 32 via transition sections 36.2. Figure 7 illustrates that the ejector receptacle 36 extends from an inner opening area 36.4 outwards to the rear of the chisel holder 30 to an ejector passage opening 36.5.

[0110] Figure 14 illustrates that the width of the ejector receptacle 36 can widen, at least in some areas, towards the outside, i.e., towards the ejector passage opening 36.5. Preferably, the width of the ejector receptacle 36 widens continuously. For this purpose, the side surfaces 36.1 can, for example, be arranged at an angle to each other and enclose an opening angle p. This opening angle p can preferably be in the range between 20° and 45°, more preferably between 25° and 40°, particularly preferably between 30° and 35°, or especially between 29° and 34°. Preferably, the central longitudinal plane ME of the chisel holder 30 can correspond to the bisector of the opening angle p.

[0111] In the area of ​​the end of the ejector receptacle 36 facing the chisel holder 32, the ejector receptacle 36 forms a minimum inner transverse dimension 36.6, and in the area of ​​the ejector passage opening 36.5, a maximum outer transverse dimension 36.7. The ratio of the outer transverse dimension 36.7 to the inner transverse dimension 36.6 is preferably selected in the range between 1.3 and 2.2, more preferably between 1.5 and 2, and most preferably between 1.7 and 1.9. If the chisel holder 30 is used in a road milling application, it has proven advantageous if the outer transverse dimension is at least 30 mm.

[0112] As shown in Figures 9 and 12, it can alternatively or additionally be provided that the ejector receptacle 36 has an outlet height hA in the area of ​​the ejector passage opening 36.5 and an inlet height hE in the area of ​​the transition of the ejector receptacle 36 into the chisel receptacle 32. The inlet height hE and the outlet height hA are measured in the direction of the central longitudinal axis M of the chisel receptacle 32. As Figure 9 shows, the inlet height and the outlet height hE and hA are measured here starting from the cover section 36.3. Preferably, the inlet height hE is greater than the outlet height hA. To achieve good conveying efficiency, it is preferably provided that the ratio of the inlet height hE to the outlet height hA is selected in the range between 0.6 and 0.9.

[0113] Figure 9 illustrates that the ejector receptacle 36 forms an inlet cross-section EQ in the inner opening area and an outlet cross-section AQ at the ejector passage opening 36.5, wherein the inlet cross-section EQ and the outlet cross-section AQ are each measured perpendicular to the central longitudinal plane ME of the chisel holder 30. Preferably, the ratio of the area of ​​the outlet cross-section AQ to the area of ​​the inlet cross-section EQ is selected to be in the range between 1.0 and 1.5, preferably between 1.0 and 1.4, and most preferably between 1.1 and 1.3.

[0114] As the illustrations show, the tool holder 30 has a central longitudinal plane ME. Figure 12 shows a longitudinal section through the tool holder 30 along the central longitudinal plane ME. As the illustration shows, the central longitudinal axis M of the tool receptacle 32 lies in the central longitudinal plane ME. Additionally, the longitudinal axis 44.2 of the socket 44 may lie in the central longitudinal plane ME. This is also illustrated in Figure 12. Preferably, the central longitudinal plane ME runs in the feed direction V, as shown in Figure 12.

[0115] As shown in Figures 5 and 6, the support body 35 has a support section 40 formed on the underside of the chisel holder 30. The support section 40 has two front cutting surfaces 41.1, 41.2. These front cutting surfaces 41.1, 41.2 are arranged on both sides of the central longitudinal plane in the central longitudinal plane of the chisel holder 30. Preferably, as illustrated in the drawings, the front cutting surfaces 41.1, 41.2 are each completely located on their respective side of the chisel holder 30, laterally adjacent to the central longitudinal plane, and do not penetrate the central longitudinal plane.

[0116] It is conceivable that the two front cutting surfaces 41.1, 41.2 are connected to each other by means of a follow-up surface 42. The follow-up surface 42 penetrates the central longitudinal plane ME. The front cutting surfaces 41.1, 41.2 enclose a transverse support angle α, as shown in Figure 5. Preferably, this angle α should be in the range between 100° and 120°. The bisector of this angle α preferably lies in the central longitudinal plane ME.

[0117] As the drawings illustrate, a plug-in extension 44 is arranged on the underside of the chisel holder 30, preferably integrally formed. The front cutting surfaces 41.1, 41.2 are arranged at least partially in the feed direction in front of the plug-in extension 44. This is illustrated in Figure 6.

[0118] The support section 40 further comprises at least one rear cutting surface 43.1, 43.2. In the illustrated embodiment, two rear cutting surfaces 43.1, 43.2 are used, which in this embodiment lie in one plane and are spaced apart from each other at least partially perpendicular to the central longitudinal plane ME. The two rear cutting surfaces 43.1, 43.2 are positioned at a longitudinal support angle β relative to the front cutting surface 41.1, 41.2, each associated with one of the sides of the chisel holder 30. The longitudinal support angle β between the front cutting surface

[0119] The angle of the angle between 41.1 or 41.2 and the associated rear cutting surface 43.1 or 43.2 is preferably selected in the range between 120° and 160°. The angle bisector may be positioned such that it intersects the central longitudinal plane ME.

[0120] Figure 7 shows that the front removal surfaces 41.1 , 41.2 each transition into the rear removal surfaces 43.1 , 43.2 via an inclined surface 42.1.

[0121] The inclined surfaces 42.1 may extend in the area between two transverse edges. The front transverse edge facing the front of the chisel holder 30 forms a transition between the front cutting surface 41.1,

[0122] 41.2 and the inclined surface 42.1. The rear transverse edge facing the rear of the chisel holder 30 forms a transition between the inclined surface 42.1 and the associated rear cutting surface 43.1, 43.2. The inclined surfaces 42.1 thus transition directly into the front cutting surfaces 41.1, 41.2 and rear cutting surfaces 43.1, 43.2, respectively. However, an indirect transition is also conceivable, for example by means of a rounded transition. As shown in Figures 3 and 6, the inclined surfaces 42.1 can form an obtuse angle with both the associated front cutting surface 41.1, 41.2 and the rear cutting surface 43.1, 43.2; it is particularly preferred that the inclined surfaces form the same angle with the front cutting surfaces 41.1, 41.2 and with the rear cutting surfaces 43.1, 43.2.

[0123] The arrangement of the front and rear removal surfaces 41.1, 41.2, 43.1, 43.2 and the inclined surfaces 42.1 is preferably symmetrical to the central longitudinal plane.

[0124] The plug-in fitting 44 preferably has a cylindrical section 44.5, as shown in Figure 6. The cylindrical section 44.5 can have a front partial cylindrical surface 44.3 and / or a rear partial cylindrical surface 44.4 oriented opposite to the feed direction V.

[0125] Preferably, the maximum distance between the respective two transverse edges of the inclined surfaces 42.1, measured parallel to the central longitudinal plane ME and perpendicular to the plug-in attachment longitudinal axis 44.2, is smaller than the extent of the cylindrical section 44.5 of the plug-in attachment 44, measured parallel to the central longitudinal plane ME. The maximum distance X (see Figure 15) between the two transverse edges, measured parallel to the central longitudinal plane ME and perpendicular to the plug-in attachment longitudinal axis 44.2, should (see Figure 15) preferably be smaller than 0.7 times, and preferably smaller than 0.5 times, the maximum extent maxE of the cylindrical section 44.5 of the plug-in attachment 44, measured parallel to the central longitudinal plane ME and perpendicular to the plug-in attachment longitudinal axis 44.2, as illustrated in Figure 15.

[0126] The drawings (see especially Figure 7) illustrate that the two transverse edges of the inclined surfaces 42.1 extend at an angle £ <90° from the front of the chisel holder 30 towards the rear of the chisel holder 30, relative to the central longitudinal plane ME. This is shown by way of example in Figure 7 at one of the transverse edges. Preferably, the inclined surfaces 42.1 are designed as flat surfaces extending at an angle £ <90° to the central longitudinal plane ME, with the angle £ opening towards the rear of the chisel holder 30 and towards the top of the chisel holder 30, as shown in Figure 7. Accordingly, it is also possible that the two inclined surfaces 42.1 are V-shaped to each other in view along the longitudinal axis 44.2 of the insertion attachment and diverge in the direction from the front of the chisel holder 30 towards the rear (i.e. opposite to the feed direction V) of the chisel holder 30 (see figure).Figure 14) and / or diverge from the underside of the chisel holder 30 towards the top of the chisel holder 30 (see Fig. 6).

[0127] Preferably, the inclined surfaces 42.1 enclose an angle with each other which is selected in the range of 110° to 150° to achieve a compact design.

[0128] The socket 44 of the chisel holder projects from the underside of the chisel holder 30, as shown, for example, in Figure 6. Advantageously, the socket 44 has a three-part structure. This structure is divided, in the direction of the socket's longitudinal axis 44.2, into a first, lower shank section, which has a front shank contact surface 45 and a rear screw pressure surface 47.1; a second, middle shank section, which has the cylindrical section 44.5; and a third, upper shank section, which has a shank widening 44.1.

[0129] The second middle section is located between the first and third shaft sections.

[0130] Advantageously, the extension of the first, lower shaft section in the direction of the longitudinal axis 44.2 of the plug-in connection may be at least 30% of the maximum length of the plug-in connection 44 in this direction, in order to ensure, in the assembled state, a stable transmission of the forces of the pressure screw 20 and a stable contact of the shaft contact surface 45 with a shaft support surface 18.2 of a lower part. Additionally or alternatively, the extension of the second, middle shaft section in the direction of the longitudinal axis 44.2 of the plug-in connection may be at least 10% of the maximum length of the plug-in connection 44 in this direction, in order to ensure sufficient extensibility of the plug-in connection 44 in the direction of the longitudinal axis 44.2 of the plug-in connection.

[0131] Additionally or alternatively, the extension of the third, upper shaft area in the direction of the plug-in longitudinal axis 44.2 may be at least 5% of the maximum length of the plug-in shank 44 in this direction in order to achieve good load transfer from the chisel holder 30 to the lower part 10 in the event of overload.

[0132] The rear removal surfaces 43.1 , 43.2 are clearly identifiable, at least in some areas, arranged in the feed direction V behind the plug-in extension 44.

[0133] The plug-in connector 44 transitions into the support body 35 at its end facing the support body 35 via a shaft extension 44.1. The shaft extension 44.1 widens the cross-section of the plug-in connector 44 in the direction towards the support body 35 and radially to the plug-in connector's longitudinal axis 44.2, at least in certain areas. Preferably, the shaft extension 44.1 is formed at least in certain areas circumferentially around the plug-in connector 44.

[0134] The shaft extension 44.1 may widen the cross-section of the plug-in section 44, at least in some areas, at least in the transition to the rear wear surfaces 43.1, 43.2. Additionally or alternatively, the shaft extension 44.1 may widen the cross-section of the plug-in section 44, at least in some areas, in the transition to the two lateral inclined surfaces 42.1. Additionally or alternatively, the shaft extension 44.1 may widen the cross-section of the plug-in section 44, at least in some areas, in the transition to the two front wear surfaces 41.1, 41.2.

[0135] As can be seen in Figures 5 and 6, the shaft extension 44.1 widens the cross-section of the plug-in connector 44. It can be provided that the shaft extension 44.1 widens the cross-section of the plug-in connector 44 in the area of ​​the two sides associated with the side surfaces 35.4. Preferably, the shaft extension 44.1 extends laterally with widening sides to both sides of the plug-in connector 44 from the rear rear area to the front front area of ​​the plug-in connector 44, widening the cross-section of the plug-in connector 44 in these areas towards the support body 35 and radially towards the plug-in connector longitudinal axis 44.2. Preferably, the greatest extent LE of the widening sides in the direction of the plug-in connector longitudinal axis 44 is2 at least 5%, preferably at least 10%, particularly preferably at least 14% of the maximum length LS of the plug-in end 44, measured in this direction (see Figure 6). The maximum length LS of the plug-in end 44 extends over the shaft widening 44.1 to the support body 35 and preferably includes the greatest extent LE of the widening sides, as Figure 6 clearly shows.

[0136] It has proven advantageous if the widening sides of the shaft widening 44.1 extend over at least 50% of the maximum extent maxE of the cylindrical section 44.5 of the plug-in extension 44, which runs parallel to the central longitudinal plane ME and perpendicular to the plug-in extension longitudinal axis; it is particularly preferred that the widening sides of the shaft widening 44.1 extend over the entire depth of the plug-in extension 44, and in particular are formed circumferentially.

[0137] Preferably, or alternatively, the shaft extension 44.1 can also widen the rear area of ​​the plug-in socket 44. Particularly preferred, as the drawings show, is that the shaft extension 44.1 is continuous.

[0138] In the present embodiment, the front wear surfaces 41.1, 41.2 transition via a rounded transition of the shaft extension 44.1 into the extension sides of the shaft extension 44.1, as shown in Figure 6. The extension sides of the shaft extension 44.1 extend convexly and arcuately to the front end region of the plug-in socket 44. The shaft extension 44.1 can form a rear shaft contact surface 48. The rear shaft contact surface 48 has two side contact surfaces 48.1, which are spaced apart from each other. In particular, the side contact surfaces 48.1 can be angled relative to each other in a V-shape.

[0139] As shown in Figure 7, the side contact surfaces 48.1 of the rear shaft assembly 48 can each transition laterally into an associated widening side of the shaft widening 44.1, preferably being that one of the side contact surfaces 48.1 extends at least partially laterally next to one side of the central longitudinal plane ME and the other side contact surface 48.1 extends at least partially laterally next to the opposite side of the central longitudinal plane ME.

[0140] Figure 6 further illustrates that it is also possible for the inclined surface 42.1 to transition laterally into the shaft widening 44.1 via a rounding transition, in particular via a relief groove 49.

[0141] The support body 35, in particular at least a part of the functional surfaces molded onto the support body 35, the front and / or the rear cutting surface 41.1, 41.2, 43.1 and 43.2 and / or the inclined surfaces 42.1 can transition into the shaft extension 44.1 via a rounded transition. The rounded transition is part of the shaft extension 44.1.

[0142] As the illustrations show, the side contact surfaces 48.1 may enclose an angle that preferably opens towards the front of the chisel holder 30.

[0143] Preferably, the side contact surfaces 48.1 may form an angle with each other in the range of 45° to 100°, preferably between 50° and 90°, and particularly preferably between 66° and 76°. Correspondingly, the clamping surfaces 18.5, 18.6 of the rear overload support area 18.4 of the lower part 10 may be angled relative to each other in the range of 45° to 100°, preferably between 50° and 90°, and particularly preferably between 66° and 76°, as shown in the illustrations. In a possible embodiment of a chisel holder 30, the angle formed by the side contact surfaces 48.1 may also be in the range of 30° to 75°, preferably between 35° and 70°, and particularly preferably between 45° and 55°. Such a design is particularly recommended if it is intended that a chisel holder 30 has two flat rear cutting surfaces 43.1 , 43.2 are provided, which are angled relative to each other, as described above, for example. Correspondingly, the clamping surfaces 18.5, 18.6 of the rear overload support area 18.4 of the lower part 10 can preferably be angled relative to each other in the range between 30° and 75°, preferably between 35° and 70°, and particularly preferably between 45° and 55°, as shown in the illustrations. Preferably, the clamping surfaces 18.5, 18.6 are parallel to the respective associated side contact surfaces 48.1.

[0144] In a further embodiment of a chisel holder 30, the angle between the side contact surfaces 48.1 can also be selected in the range of 37° to 87°, preferably in the range of 42° to 82°, and particularly preferably in the range of 57° to 67°. Such a configuration is particularly recommended when a chisel holder 30 is provided with a flat rear cutting surface 43.1, 43.2 or with two flat rear cutting surfaces 43.1, 43.2 that are parallel to each other, in particular aligned with each other, as described above, for example. Correspondingly, the clamping surfaces 18.5, 18.6 of the rear overload support area 18.4 of the lower part 10 can preferably be angled to each other in the range between 37° and 87°, preferably between 42° and 82°, and particularly preferably between 57° and 67°, as shown in the illustrations.Preferably the clamping surfaces 18.5, 18.6 are parallel to the respective associated side contact surfaces 48.1.

[0145] Figure 14 shows that each side contact surface 48.1 is arranged completely or partially laterally next to the central longitudinal plane ME, such that each side contact surface 48.1 is assigned to one side of the chisel holder 30. Preferably, the side contact surfaces 48.1 do not penetrate the central longitudinal plane ME, as shown in Figure 14. In this case, it is preferably the case that the two side contact surfaces 48.1 are connected to each other directly or indirectly via an overload contact surface 48.2.

[0146] It is conceivable that the two side contact surfaces 48.1 are indirectly connected to the overload contact surface 48.2 via a rounded transition 48.3. Preferably, the side contact surfaces 48.1 and the overload contact surface 48.2 each form the same angle and / or the side contact surfaces 48.1 and the overload contact surface 48.2 are symmetrical relative to the central longitudinal plane ME. Preferably, the overload contact surface 48.2 is designed as a flat surface. The side contact surfaces 48.1 can also be designed as flat surfaces.

[0147] The drawings illustrate that the overload support surface 48.2 and / or the side support surfaces 48.1 can at least partially transition into the rear removal surfaces 43.1, 43.2 or the single rear removal surface 43.1, 43.2.

[0148] Figure 8 illustrates that the plug-in attachment 44 has a shaft section which preferably includes at least a partial cylindrical section 44.5. The cylindrical section 44.5 may have a front partial cylindrical surface 44.3 and / or a rear partial cylindrical surface 44.4 oriented opposite to the feed direction. Preferably, the cylindrical section 44.5 forms an at least partially circumferential cylinder, which may be interrupted only by one or more lateral indentations 44.6, as shown in Figure 8. The cylinder axis of the cylindrical section 44.5 preferably aligns with the longitudinal axis 44.2 of the plug-in attachment and is particularly preferably located in the central longitudinal plane ME.

[0149] Preferably, the cylinder section 44.5 adjoins the shank extension 44.1. In a chisel holder 30 according to the invention, the widening sides of the shank extension 44.1 may transition laterally, at least partially, into the front and / or rear partial cylinder surface 44.3, 44.4 via rounded transitions, and / or the side contact surfaces 48.1 of the rear shank contact 48 transition at least partially into the rear partial cylinder surface 44.4 via rounded transitions, and / or the overload contact surface 48.2, facing away from the support body 35, transitions at least partially into the rear partial cylinder surface 44.4 via a rounded transition.

[0150] In the region of its free end, the plug-in connector 44 has a front shaft assembly, as illustrated in Figures 5 and 6. The front shaft assembly has a front shaft contact surface 45. Preferably, the front shaft contact surface 45 forms two convex sub-surfaces 45.1, 45.2. The front shaft contact surface 45 and / or at least one of the sub-surfaces 45.1, 45.2 can preferably form a partial cylindrical surface of a cylinder with a contact to the cylinder axis Z, as can be seen, inter alia, in Figures 8 and 9.

[0151] Particularly preferred is the arrangement of the two partial surfaces 45.1, 45.2 spaced apart from each other, with a groove 46 preferably formed in the spaced area. The groove 46 serves to receive the aforementioned shaped element, which is inserted into the recess 18.3 of the lower part 10. This ensures alignment of the chisel holder 30 with respect to the lower part 10 and prevents rotation.

[0152] The groove 46 extends in the direction of the longitudinal extension of the plug-in extension 44 and preferably parallel to the contact cylinder axis Z and / or inclined to the plug-in extension longitudinal axis 44.2. The inclination angle of the groove 46 (in particular of the groove base) relative to the plug-in extension longitudinal axis 44.2 can preferably be selected in the range between 2° and 10°.

[0153] Figure 8 illustrates that the front convex shank contact surface 45, with its sub-surfaces 45.1, 45.2, can be arranged in a special way. Figure 8 illustrates a cross-sectional surface SF of the chisel holder 30, which is formed by a cutting plane SE. The cutting plane SE runs parallel to and at a distance from the central longitudinal plane ME through the chisel holder 30. The cutting plane SE intersects at least one of the two front cutting surfaces 41.1, 41.2 of the cutting surface pair and the front shank contact surface 45.

[0154] As the drawing shows, a front cutting edge SK of the cutting surface 41.1, 41.2 and a front cutting edge 45.3 of the front shank contact surface 45 are formed in the cut surface. The front cutting edge 45.3 and the front cutting edge SK enclose an undercut angle y of at least 103° and at most 114°. Preferably, the undercut angle y opens towards the front, i.e., in the feed direction V, as shown in Figure 8. The function of this undercut angle y will be explained in more detail later.

[0155] Figure 8 further illustrates that the projections of the plug-in longitudinal axis 44.2 and the cutting edge 45.3 into the central longitudinal plane ME form a shaft angle. <p miteinander einschließen. Dieser Schaftwinkel <p öffnet sich zum freien Ende des Steckansatzes 44 hin. Der Schaftwinkel <p ist vorzugsweise im Bereich zwischen 2° und 10°, besonders bevorzugt im Bereich zwischen 2° und 8°, gewählt.

[0156] As shown in Figure 9, the front shaft contact surface 45 preferably forms a partially cylindrical surface. Preferably, the contact cylinder axis Z of the partially cylindrical surface of the front shaft contact surface 45 and the longitudinal axis 44.2 of the plug-in connector enclose an angle q that opens towards the free end of the plug-in connector 44.

[0157] The axial angle q between the contact cylinder axis Z of the partially cylindrical surface of the front shaft contact surface 45 and the longitudinal axis 44.2 of the plug-in attachment can be selected in the range between 2° and 10°, preferably in the range between 2° and 8°, to ensure secure anchoring of the plug-in attachment 44 in the plug receptacle 18 of the lower part 10. It should be noted again that the cylinder axis of the cylinder section 44.5 is preferably formed by the longitudinal axis 44.2 of the plug-in attachment. Due to the inclination of the contact cylinder axis Z relative to the longitudinal axis 44.2 of the plug-in attachment, the partially cylindrical surface formed by the front shaft contact surface 45 is inclined relative to the cylinder section 44.5 by the axial angle q, preferably in the range between 2° and 10°, and particularly preferably between 2° and 8°.

[0158] In the embodiment illustrated in Figure 9, it is provided that, particularly for reasons of symmetry, the plug-in longitudinal axis 44.2 of the plug-in attachment 44 and the contact cylinder axis Z of the partially cylindrical outer surface of the front shaft contact surface 45 run in the central longitudinal plane ME.

[0159] A particularly preferred embodiment of a chisel holder 30 according to the invention can be such that the front cutting edge 45.3 of the shank contact surface and the contact cylinder axis Z run parallel to each other and the axis angle q and the shank angle <p sich somit entsprechen, wie Figur 9 veranschaulicht.

[0160] Figure 8 illustrates that it may be provided that at least one side contact surface 48.1 of the rear shaft contact surface 48 forms a rear cutting edge 48.1.1 in the cutting surface SF in the section plane SE. It may be provided that

[0161] 1. the rear cutting edge 48.1.1 and / or the overload contact surface 48.2 runs parallel to the plug-in longitudinal axis 44.2 and / or parallel to the contact cylinder axis Z, or that the rear cutting edge 48.1.1 and / or the overload contact surface 48.2 runs at an angle T to the plug-in longitudinal axis 44.2 and / or at an angle to the contact cylinder axis Z, wherein preferably the angle T is selected to be less than 5°.

[0162] 2. The rear cutting edge 48.1.1 and / or the overload support surface 48.2 is at an angle w to the front cutting edge 45.3, the angle w preferably opening towards the insertion side of the chisel holder 30, as shown in Figure 8. Preferably, the angle w between the front cutting edge 45.3 and the rear cutting edge 48.1.1 and / or the overload support surface 48.2 is selected in the range of 0.5° to 7°, preferably in the range of 1.5° to 6°, and particularly preferably in the range of 2.5° to 5°. In this way, a secure load transfer via the rear shank support 48 is guaranteed, especially in the case of overload.

[0163] As shown in Figure 8, among others, the plug-in attachment 44 has a screw receptacle 47 on its rear side, which forms a flat screw pressure surface 47.1. The screw pressure surface 47.1 penetrates the central longitudinal plane ME. The plane in which the screw pressure surface 47.1 lies is at a pressure angle o to the front cutting edge 45.3 or to the contact cylinder axis Z of the cylinder that forms the convex front shaft contact 45. This pressure angle o is preferably selected in the range between 30° and 45°.

[0164] Figures 6 and 8 show the spatial arrangement of the pressure screw 20 to the screw receptacle 47 in the assembled state of the chisel holder 30.

[0165] As illustrated in Figure 14, a relief groove 49 and / or a rounded transition can be arranged in the transition area between the shaft widening 44.1 and the support section 33 of the support body 35. The geometry formed by the relief groove 49 and / or the rounded transition can at least partially surround the plug-in extension 44. A sealing element (not shown) may be accommodated in this relief groove 49 and / or in the area of ​​the rounded transition, which at least partially surrounds the plug-in extension 44.

[0166] A stress-optimized design is achieved in such a construction when a concave rounded transition of the plug-in end 44 is provided to guide it into the shank extension 44.1. Additionally or alternatively, the shank extension 44.1 can also have a transition geometry with a relief groove 49 and / or a rounded edge, by which it transitions into the support body 35. To mount the chisel holder 30 to the lower part 10, the plug-in end 44 is inserted with its free end into the plug-in receptacle 18. The insertion extension 18.1 facilitates the insertion of the plug-in end 44.

[0167] The insertion movement of the plug-in end 44 into the plug-in receptacle 18 is limited by the front support surfaces 15.1, 15.2 and the rear support surfaces 16.1 and 16.2 of the lower part 10. The chisel holder 30 abuts these support surfaces 15.1, 15.2, 16.1, 16.2 with its front cutting surfaces 41.1, 41.2 and its rear cutting surfaces 43.1, 43.2.

[0168] The pressure screw 20 can be screwed into the screw receptacle 19 of the lower part 10. The pressure screw 20 then contacts the screw pressure surface 47.1 of the screw receptacle 47. This draws the chisel holder 30 into the socket 18. While the pressure screw 20 is being tightened, the front shaft contact surface 45 slides along the front shaft support surface.

[0169] 18.2 and the chisel holder 30 is pulled into the socket 18. Once the chisel holder 30 has reached its mounting position, the front cutting surfaces 41.1, 41.2 are pressed onto the front support surfaces 15.1, 15.2 and the rear cutting surfaces

[0170] 43.1, 43.2 are pressed onto the rear support surfaces 16.1, 16.2. Simultaneously, the front shaft support surface 45 is also pressed against the front shaft support surface 18.2 of the lower part 10. Thus, the chisel holder 30 is securely fixed in the lower part 10.

[0171] The rear shank support 48, with its side contact surfaces 48.1, is positioned a short distance from the associated clamping surfaces 18.5, 18.6 of the lower part 10. This is illustrated in Figure 13. Furthermore, the overload contact surface 48.2 is positioned a distance from the clamping surface 18.7 of the lower part 10. Preferably, this distance is chosen to be less than 2 mm, preferably less than 1 mm, in order to minimize the formation of the chisel holder 30 in the event of an overload. If an overload now acts on the chisel holder 30, the chisel holder 30 is elastically deformed, and the side contact surfaces 48.1 come into contact with the associated clamping surfaces 18.5, 18.6. Thus, additional support of the chisel holder 30 is achieved. If the overload is particularly high, the clamping surfaces 18.5, 18.6 are elastically deformed and deflect outwards towards the corresponding sides of the chisel holder 30. Then the overload contact surface 48.2 comes into contact with the clamping surface 18.7.Thus, the deflection movement of the clamping surfaces 18.5, 18.6 is limited in order to avoid damage to the lower part 10 and to additionally obtain a further support area to absorb the overload.

[0172] After the overload event has ended, the chisel holder 30 returns to its original position as shown in Figure 13.

[0173] In the event of overload, stress conditions arise in the chisel holder 30 that attempt to move the plug-in end 44 of the chisel holder 30 out of the plug-in receptacle 18 in the direction of the plug-in end's longitudinal axis 44.2. Since, as described above, the front shank contact surface 45, together with the front cutting surfaces 41.1, 41.2, each encloses the undercut angle y, which is selected in the range between at least 103° and at most 114°, an undercut acting in the direction of the plug-in end's longitudinal axis 44.2 is created, thus generating a positive-locking connection in the direction of the plug-in end's longitudinal axis 44.2. This positive-locking connection therefore prevents the plug-in end 44 from being pulled out of the plug-in receptacle 18 in the event of overload.

[0174] Figure 2 illustrates that, with the chisel holder 30 mounted, an ejector tool can be guided through the ejector receptacle 36 towards the chisel holder 32. Since the ejector receptacle 36 widens radially towards the central longitudinal axis M of the chisel holder 32, ample space is provided for the ejector tool. This facilitates the removal of the chisel.

[0175] During machining, the machining forces are transferred from the tool holder 30 to the lower part 10. The force is transferred from the front cutting surfaces 41.1, 41.2 and the rear cutting surfaces 43.1, 43.2 of the tool holder 30 to the front support surfaces 15.1, 15.2 and the rear support surfaces 16.1, 16.2 of the lower part 10. As the tool usage time increases, the front cutting surfaces 41.1, 41.2 and the rear cutting surfaces 43.1, 43.2 and / or the front support surfaces 15.1, 15.2 and the rear support surfaces 16.1 and 16.2 may wear down. This causes the tool holder 30 to shift relative to the lower part 10. By using the inclined surfaces 42.1, which are opposite the lower part 10 in the area of ​​the recesses 17, a generous settling space (see Figure 3) is created which compensates for this wear.Thus, the chisel holder 30 can continue to be reliably and as intended supported on the front and rear support surfaces 15.1 , 15.2 , 16.1 , 16.2 of the lower part 10.

Claims

Claims 1. Chisel holder (30) for a soil cultivation machine, in particular for a road milling machine, a stabilizer, a recycler, or a surface miner, with a support body (35) which has a chisel receptacle (32) or carries a cutting tip in the area of ​​a working side, wherein the support body (35) indirectly or directly carries a plug socket (44) on a plug socket side, wherein the plug socket (44) has a plug socket longitudinal axis (44.2), wherein the plug socket longitudinal axis (44.2) lies in a central longitudinal plane (ME) of the chisel holder (30), wherein the support body (35) has two front cutting surfaces (41.1, 41.2) forming a cutting surface pair.2) having, which are at an angle to each other such that they enclose a transverse support angle (a) and which are arranged at least partially in front of the plug-in end (44), wherein the plug-in end (44) has at least one convex front shank contact surface (45) on its front side, and wherein a cutting surface (SF) running parallel and at a distance from the central longitudinal plane (ME) through the chisel holder (30) intersects one of the two front cutting surfaces (41.1, 41.2) of the cutting surface pair and the front shank contact surface (45), characterized in that the front cutting edge (SK) of the cutting surface (41.1, 41.2) and the front cutting edge (45.3) the front shaft contact surface (45) of the cutting surface (SF) enclose an undercut angle (y), wherein this undercut angle (y) is at least 103° and at most 114°, and / or that the front shaft contact surface (45) forms a semi-cylindrical shell surface, wherein the contact cylinder axis (Z) of the semi-cylindrical shell surface of the front shaft contact surface (45) and the plug-in longitudinal axis (44.2) enclose an axis angle (q) with each other, which opens towards the free end of the plug-in plug (44).

2. Chisel holder (30) according to claim 1, characterized in that the plug-in longitudinal axis (44.2) of the plug-in extension (44) and the contact cylinder axis (Z) of the partially cylindrical outer surface of the front shaft contact surface (45) run in the central longitudinal plane (ME).

3. Chisel holder (30) according to claim 1 or 2, characterized in that the axial angle (q) between the contact cylinder axis (Z) of the partially cylindrical outer surface of the front shank contact surface (45) and the plug-in longitudinal axis (44.2) is in the range between 2° and 10°.

4. Chisel holder (30) according to one of claims 1 to 3, characterized in that the plug-in end (44) has a screw receptacle (47) with a flat screw pressure surface (47.1) on its rear side opposite the front shank contact surface (45), and that the screw pressure surface (47.1) and the front cutting edge (45.3) of the front shank contact surface (45) in the cutting surface (SF) and / or the The screw pressure surface (47.1) and the contact cylinder axis (Z) enclose an acute pressure angle (o) with each other, wherein the pressure angle (o) is preferably selected in the range between 30° and 45°.

5. Chisel holder (30) according to one of claims 1 to 4, characterized in that the plug-in extension (44) has a cylindrical section (44.5) with a front partial cylindrical surface (44.3) in an area between the support body (35) and the front shank contact surface (45), and that the cylinder axis of this cylindrical section (44.5) runs along the longitudinal axis (44.2) of the plug-in extension.

6. Chisel holder according to claim 5, characterized in that the cylinder section has a rear partial cylinder surface (44.4) which is arranged on the rear side of the plug-in attachment (44) opposite the front partial cylinder surface (44.3) and that preferably the front partial cylinder surface (44.3) and the rear partial cylinder surface (44.4) are arranged in the direction of the plug-in attachment longitudinal axis (44.2) in the area between the pressure surface (47.1) of the screw receptacle (47) and the support body (35).

7. Chisel holder according to one of claims 1 to 6, characterized in that a shank widening (44.1) is arranged in the area between the front shank contact surface (45) and the support body (35), which extends the plug-in extension (44) into the support body (35) such that the shaft widening (44.1 ) increases the cross-section of the plug-in end (44) at least in some areas in the direction towards the support body (35) and radially to the plug-in end longitudinal axis (44.2), wherein it is preferably provided that the shaft widening (44.1 ) extends at least in some areas in the region of the front of the plug-in end (44), and that the shaft widening (44.1 ) is preferably formed circumferentially.

8. Chisel holder according to claim 7, characterized in that the shank widening (44.1 ) is arranged in the area of ​​the front of the plug-in extension (44) between the support body (35) and the cylinder section (44.5).

9. Chisel holder according to one of claims 1 to 8, characterized in that a rear shank support (48) is arranged on the rear side of the plug-in extension (44) opposite the front shank support surface (45), which has two side support surfaces (48.1 ) angled to each other, wherein it is preferably provided that the angle between the side support surfaces (48.1 ) is selected in the range between 45° and 100°, preferably between 50° and 90°, particularly preferably between 66° and 76°.

10. Chisel holder according to any one of claims 1 to 8, characterized in that a rear shank support (48) is arranged on the rear side of the socket (44) opposite the front shank support surface (45), the rear shank support having two side support surfaces (48.1) angled to each other, wherein preferably the angle between the side support surfaces (48.1) is selected in the range between 30° and 75°, preferably between 35° and 70°, and most preferably between 45° and 55°, or that the angle between the side support surfaces (48.1) is selected in the range between 37° and 87°, preferably in the range between 42° and 82°, and most preferably in the range between 57° and 67°.

11. Chisel holder according to claim 9 or 10, characterized in that the rear shank assembly (48) is formed at least partially by the shank widening (44.1).

12. Chisel holder according to one of claims 9 to 11, characterized in that the side contact surfaces (48.1 ) are each assigned to one side of the chisel holder (30) and that the angle enclosed between the side contact surfaces (48.1 ) opens towards the front of the chisel holder (30).

13. Chisel holder according to one of claims 9 to 12, characterized in that the side contact surfaces (48.1 ) are connected to each other indirectly or directly via an overload contact surface (48.2).

14. Chisel holder according to one of claims 1 to 13, characterized in that the support body (35) has at least one rear cutting surface (43.1 , 43.2), wherein the at least one rear cutting surface (43.1 , 43.2) is arranged at least partially behind the insertion point (44) in the feed direction (V), and wherein it is preferably provided that the at least one rear cutting surface (43.1 , 43.2) is at an angle to the front cutting surfaces (41.1 , 41.2).

15. Chisel holder (30) for a soil cultivation machine, in particular for a road milling machine, a stabilizer, a recycler, or a surface miner, with a support body (35) which has a chisel receptacle (32) in the area of ​​a working side or at least carries a cutting tip, wherein the support body (35) indirectly or directly carries a plug socket (44) on a plug socket side, wherein the plug socket (44) has a plug socket longitudinal axis (44.2), wherein the plug socket longitudinal axis (44.2) lies in a central longitudinal plane (ME) of the chisel holder (30), wherein the plug socket (44) has at least one convex front shank contact surface (45) on its front side, characterized in that that the front shaft contact surface (45) forms a semi-cylindrical shell surface, and that the contact cylinder axis (Z) of the semi-cylindrical shell surface and the plug-in longitudinal axis (44.2) enclose an axis angle (q) with each other, which opens towards the free end of the plug-in end (44).

16. Chisel holder according to claim 15, characterized in that the support body (35) has two front cutting surfaces (41.1 , 41.2) forming a pair of cutting surfaces, which are at an angle to each other such that they enclose a transverse support angle (a) and that the front cutting surfaces (41.1 , 41.2) are arranged at least partially in front of the insertion end (44) in the feed direction (V).

17. Chisel holder according to one of claims 1 to 16, characterized in that the plug-in end (44) has at least one convex, in particular a partially cylindrical, front shank contact surface on its front side, and wherein it is preferably provided that the front shank contact surface forms two partial surfaces (45.1, 45.2) which are spaced apart from each other by a groove (46), wherein the groove (46) extends in the direction of the longitudinal extent of the plug-in end (44), wherein it is particularly provided that the groove (46) is inclined to the longitudinal axis (44.2) of the plug-in end and / or parallel to the contact cylinder axis (Z).

18. Chisel holder according to one of claims 1 to 17, characterized in that at least one side contact surface (48.1 ) of the rear shank contact (48) forms a rear cutting edge (48.1 .1 ) in the cutting surface (SF), that the rear cutting edge (48.1.1 ) and / or the overload contact surface (48.2) of the rear shank contact (48) runs parallel to the plug-in longitudinal axis (44.2) and / or parallel to the contact cylinder axis (Z), or that the rear cutting edge (48.1.1 ) and / or the overload contact surface (48.2) runs at an angle (T) TO the plug-in longitudinal axis (44.2) and / or at an angle to the contact cylinder axis (Z), wherein it is preferably provided that the angle (T) is selected to be less than 5°.

19. Tool system comprising a tool holder (30) and a lower part (10), wherein the lower part (10) has a socket (18), wherein the tool holder (30) is mounted in the socket (18) with a socket projection (44), wherein the lower part (10) has support surfaces (15.1, 15.2, 16.1, 16.2) on which the tool holder (30) is supported with cutting surfaces (41.1, 41.2, 43.1, 43.2) of a support body (35), that the socket projection (44) bears against a front shank support surface (18.2) of the socket (18) in the feed direction (V) with a front shank contact surface (45), that a pressure screw (20) acts on the opposite rear side of the shank, pressing the shank contact surface (45) against the front The shaft support surface (18.2) presses, characterized in that between the shaft support surface (18.2) and the front shaft contact surface (45) a longitudinal axis (44) is formed in the direction of the plug insertion longitudinal axis.2) the plug-in end (44) forms a positive locking connection which blocks an offset of the chisel holder (30) relative to the lower part (10) in the direction out of the plug-in receptacle (18).

20. Tool system according to claim 19, comprising a chisel holder (30) according to any one of claims 1 to 18.

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