Base for accommodating a chisel holder

Abstract

The invention relates to a base (10) for accommodating a chisel holder (30), comprising a main body (13) which has a holder seat (14) for accommodating the chisel holder (30), the holder seat (14) having: a socket (18); at least one front supporting surface (15.1, 15.2), which is located at least partially in front of and / or to the side of the socket (18); and at least one rear supporting surface (16.1, 16.2), which is located at least partially behind the socket (18). In order to ensure that a chisel holder (30) mounted in the base (10) remains securely fastened even under exceptionally high loads, the present invention is designed so that the main body (13) has two clamping surfaces (18.5, 18.6) of a rear overload support section (18.4) in the insertion area that leads into the socket (18), each clamping surface (18.5, 18.6) facing a side of the main body (13).

Description

[0001] Lower part for holding a chisel holder

[0002] The invention relates to a lower part for receiving a chisel holder with a base body which has a holder receptacle for receiving the chisel holder, wherein the holder receptacle has a plug-in receptacle, wherein the holder receptacle has at least one front support surface which is arranged at least partially in front of and / or laterally to the side of the plug-in receptacle and wherein the holder receptacle has at least one rear support surface which is arranged at least partially behind and / or laterally to the side of the plug-in receptacle.

[0003] In a lower part according to the invention, the plug-in receptacle is integrated into the upper surface of the lower part. The plug-in receptacle can extend from the upper surface towards the underside, preferably all the way to the underside, in the form of an opening. Preferably, the underside of the lower part has a connection surface by means of which the lower part can be positioned and fastened onto a milling drum tube. When the lower part is used as intended, the front side is located at the front of the lower part in the feed direction, and the rear side is located at the rear of the lower part in the feed direction.

[0004] In a lower part according to the invention, a plane of symmetry may be formed. This means, in particular, that not the entire lower part needs to be symmetrical about this plane of symmetry, but rather that the functional surfaces or functional components of the lower part described below are designed symmetrically relative to the plane of symmetry.

[0005] Functional surfaces or functional components refer to surfaces or components that are essential for the function of the lower part and for fixing a chisel holder in the lower part. These may include, in particular, the functional surfaces and functional components described in more detail in the following application text:

[0006] - Front and / or rear support surfaces

[0007] - Front shaft support surface

[0008] - Clamping surfaces and / or securing surface of a rear overload support area

[0009] - Holder mount

[0010] - Plug socket

[0011] - And / or screw mount

[0012] The symmetrical design allows for simple manufacturing, for example by forging, and ensures that the tool holder can be interchanged at any mounting location 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.

[0013] In the lower parts according to the invention, it is particularly possible that two front support surfaces are arranged completely or partially on both sides of the plane of symmetry. Preferably, the two front support surfaces each form the same angle with the plane of symmetry.

[0014] In the case of sub-parts according to the invention, the plane of symmetry may run in the feed direction or substantially in the feed direction.

[0015] Preferably, the central longitudinal axis of the plug receptacle lies in the plane of symmetry.

[0016] At least part of the support surfaces of the lower parts according to the invention can be designed as flat surfaces, either completely or at least partially. A chisel holder comprising a support body is known from EP 2 729 666 A2. 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 plug-in projection on its side facing away from the machining side. Front cutting surfaces are provided in the area in front of the plug-in projection, and rear cutting surfaces are provided in the area behind the plug-in projection. 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 on a base part with its socket facing in the direction of the socket's longitudinal axis. The insertion movement is limited by the front and rear cutting surfaces, which abut corresponding support surfaces on the base part. A pressure screw is used to fix the chisel holder in the base part, acting on a pressure surface of the socket.

[0017] During operation, unexpectedly high stress forces may act on the chisel. These strong stress forces occur during exceptional operational events. For example, a chisel might strike a particularly hard object during operation, such as a manhole cover on a road milling machine. In this situation, 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 to both the holder and the lower part.

[0018] The object of the invention is to provide a lower part of the type mentioned above, which guarantees a secure fastening of the chisel holder in the lower part even under heavy loads.

[0019] This task is accomplished by providing the base body with two clamping surfaces of a rear overload support area in the insertion area into the socket, with each clamping surface facing one side of the base body. The rear overload support area is specifically designed to transfer forces from the rear of the chisel holder's socket into the overload support area of ​​the lower part, to which the chisel holder is mounted, in the event of an overload. The two spaced-apart clamping surfaces ensure effective force transmission at different points, creating a support distance that is also well-suited for moment transmission. This improves the operational reliability of the entire tool system, and especially the lower part, in the event of an overload.Furthermore, the fact that the overload support area is at least partially integrated into the plug socket enables a space-saving design.

[0020] According to a preferred embodiment of the invention, it can be provided that the clamping surfaces each have a flat surface part, that these surface parts are angled to each other in a V-shape, and that these surface parts enclose an angle with each other, preferably in the range between 45° and 100°, more preferably between 50° and 90°, particularly preferably between 66° and 76°.

[0021] According to a variant of the invention, it can also be provided that these surface parts enclose an angle with each other in the range between 30° and 75°, preferably in the range between 35° and 70°, particularly preferably in the range between 45° and 55°, or that these surface parts enclose an angle with each other in the range between 37° and 87°, preferably in the range between 42° and 82°, particularly preferably in the range between 57° and 67°.

[0022] The V-shaped or angled positioning further restricts the movement of the chisel holder relative to the lower part; for example, the freedom of movement in the circumferential direction of the socket is restricted, so that rotation of the chisel holder relative to the lower part is hindered, especially in the case of overrun.

[0023] An angled positioning of the two clamping surfaces in the range between 45° and 100° enables a design in which a robust geometry of the chisel shank of the chisel holder can be realized in the overload support area. This improves the component strength. Particularly good force transmission is achieved in an angle range between 50° and 90°.

[0024] If the chisel holder has side contact surfaces corresponding to the clamping surfaces of the base, and these side contact surfaces bear against the clamping surfaces at least in the case of overload, then a kind of elastic spring system is formed. In the case of overload, the side contact surfaces move the clamping surfaces outwards, so that the acting force is reduced by the spring action.

[0025] If the angle between the clamping surfaces is chosen to be in the range between 66° and 76°, this results in good power transmission, especially in road milling applications, and prevents the chisel holder from being clamped in the rear overload support area of ​​the lower part in the event of overload.

[0026] Preferably, the clamping surfaces are at least partially designed as flat surfaces so that a defined force transmission is achieved. However, it is also conceivable that the clamping surfaces are contoured, for example curved, according to the desired application.

[0027] According to one embodiment of the invention, it can be provided that the rear overload support area has a securing surface which is arranged between the two clamping surfaces.

[0028] Forces can also be transmitted via the safety surface in the event of an overload. In particular, it may be the case that, initially, either the clamping surfaces or the safety surface with the chisel holder comes into contact. If the overload is particularly severe, then either the safety surface or the clamping surfaces come into contact to provide additional support.

[0029] To avoid stress concentrations in the lower part, the securing surface can be designed to transition indirectly or directly laterally into the clamping surfaces via rounded transitions and / or flat transition surfaces (chamfers). This also reduces the risk of the chisel holder becoming jammed in the rear overload support area of ​​the lower part.

[0030] One possible embodiment of the invention is such that the two clamping surfaces and the securing surface each form an angle, with these two angles preferably being equal. Preferably, the angle between the clamping surfaces and the securing surface is selected to be in the range of 40° to 68°. This angle range is particularly suitable for soil cultivation machines in road construction. For road milling machines and stabilizers, an angle range between 45° and 62.5° is preferably suitable. An angle range particularly suitable for road milling machines lies in the range of 52° to 57°.

[0031] One possible embodiment of the invention is such that the socket has an insertion extension in the area of ​​the upper surface of the base body, which widens the cross-section of the socket from the underside of the base body towards the upper surface and radially outwards, and that the clamping surfaces and / or the locking surface are arranged at least partially within the insertion extension and at least partially define it. The insertion extension can be used to accommodate a shank extension of the chisel holder, the shank extension being arranged in the area of ​​the chisel holder's insertion point. This allows for a strengthening of the insertion point's cross-section in this particularly vulnerable transition area. Furthermore, this area, in which the chisel holder has been reinforced, can now be effectively used to reliably transfer the applied load forces from the chisel holder to the lower part in the event of an impact.

[0032] The shank extension of the chisel holder may widen the cross-section of its insertion point, at least in some areas, as it transitions to the rear cutting surfaces. Additionally or alternatively, the shank extension may widen the cross-section of the insertion point, at least in some areas, as it transitions to the lateral inclined surfaces of the chisel holder. Additionally or alternatively, the shank extension may widen the cross-section of the insertion point, at least in some areas, as it transitions to the two front cutting surfaces of the chisel holder.

[0033] If the insertion extension is designed to have side sections that extend laterally from the two clamping surfaces of the base body and from the rear of the base body towards the front, then recessed receiving sections of the insertion extension are also formed in the area of ​​the sides of the lower part. These sections can accommodate material thickenings of the shank extension of the tool holder. This significantly improves the lateral stability of the tool system, especially in overload situations.

[0034] Within the scope of the invention, it can be the case, in particular, that the insertion extension extends all around the plug receptacle.

[0035] According to one embodiment of the invention, the rear support surface can transition into a front support surface on both sides of the base body via a recess recessed into the base body, preferably designed as a rounded transition. Alternatively, the rear support surfaces can transition into a front support surface on each side of the base body via a recess recessed into the base body, preferably designed as a rounded transition. This creates distinct front and rear support surfaces, resulting in improved functionality during operation. In particular, the recess forms a retraction space. The chisel holder can retract into this retraction space as the support surfaces wear down.If, in addition, a clamping surface of the rear overload support area is provided, at least partially, in the area of ​​the recesses, then the rear overload support area can be integrated into the lower part in a space-saving manner. Furthermore, the recess in the area of ​​the clamping surface creates a material weakening that promotes the deformability of the clamping surface in the event of an overload and thus contributes to more effective force transmission. A particularly preferred embodiment of the invention is such that at least one front shaft support surface of a front shaft assembly is provided in the socket and facing the underside of the base body, and that the front shaft support surface is arranged on the side of the socket opposite the rear overload support area.The front shank support surface can be used to securely support the chisel holder's insertion point in the socket, while simultaneously the insertion point rests against the support surfaces of the lower part's mounting bracket. A pressure screw, for example, can be applied to the rear of the insertion point, clamping the chisel holder to the lower part. In the event of an overload, the pressure applied to the front shank support surface and the rear overload support area creates a support gap along the longitudinal axis of the insertion point. This support gap effectively dissipates bending stresses acting on the insertion point in the event of an overload.

[0036] Preferably, the front shank support surface can be divided into two sub-surfaces by means of a recess formed in the base body. A positive locking element can preferably be inserted into the recess, which secures the chisel holder against rotation relative to the lower part in the circumferential direction of the shank receptacle.

[0037] According to a particularly preferred embodiment of the invention, the front shank support surface may have a partial cylindrical surface of a hollow cylinder, and the cylinder axis of this hollow cylinder may form a clamping angle between 5° and 15°, preferably between 9° and 12°, with the clamping surfaces of the overload support area and / or the overload contact surface of the overload support area. This clamping angle ensures a positive locking connection of the chisel holder in the lower part in the event of an overload, against the front shank support surface on the one hand and the rear overload support area on the other. This positive locking connection prevents displacement of the plug-in end in the plug receptacle in the event of an overload. Thus, undefined deformation states that could lead to excessive loading and consequently damage to the lower part are prevented or limited.

[0038] A lower part according to the invention can, for example, be characterized in that the two front support surfaces are separated from each other at the front by means of a recess, preferably being arranged opposite the overload support area.

[0039] It is also conceivable that the rear support surfaces are separated from each other by a transition section recessed into the base body, and that this transition section is located in the area of ​​the rear overload support zone. This separation of the rear support surfaces from at least parts of the overload support zone achieves improved functionality. In particular, material deformations that occur during operation in the area of ​​the rear support surfaces, the clamping surfaces, and / or the securing surface will then not impair the functionality of the adjacent functional components or surfaces.

[0040] Therefore, it may also be provided that the transition section has a surface area set back from the rear support surfaces, which at least partially merges into the clamping surfaces and / or the securing surface. As the foregoing explanations clarify, rear support surfaces may be arranged adjacent to the transition section on both sides. These may be aligned with each other or angled to each other, particularly at an obtuse angle.

[0041] The object of the invention is also achieved with a tool combination comprising a lower part according to any one of claims 1 to 13 and a chisel holder, wherein the chisel holder is inserted into the socket of the lower part by means of a plug-in socket and the chisel holder is supported by wear surfaces on the support surfaces of the lower part, and wherein the chisel holder has a rear shank with side contact surfaces that face the clamping surfaces. The invention is explained in more detail below with reference to an embodiment illustrated in the drawings. The drawings show:

[0042] Figure 1 shows a tool system with a lower part and a chisel holder in side view,

[0043] Figure 2 shows the tool system according to Figure 1 in a perspective view from behind,

[0044] Figure 3 shows the tool system according to Figures 1 and 2 in the side view opposite Figure 1,

[0045] Figure 4 shows the tool system according to Figures 1-3 in a perspective view from the front.

[0046] Figure 5 shows a chisel holder in a perspective front view,

[0047] Figure 6 shows the chisel holder according to Figure 5 in combination with a pressure screw and in a perspective side view,

[0048] Figure 7 shows the chisel holder according to Figures 5 and 6 in a perspective view from below,

[0049] Figure 8 shows the chisel holder according to Figures 5-7 in a sectional view,

[0050] Figure 9 shows the chisel holder according to Figures 5-8 in longitudinal section along its central longitudinal plane,

[0051] Figure 10 shows the lower part of the tool system according to Figures 1-4 in a perspective side view,

[0052] Figure 11 shows the lower part according to Figure 10 in a perspective view from the rear, Figure 12 shows the tool system according to Figures 1-4 in longitudinal section,

[0053] Figure 13 shows the tool system according to Figures 1-4 along the cutting path shown in Figure 3 with XIII-XIII,

[0054] Figure 14 shows another representation of the chisel holder according to Figures 5-9 in a view from below and

[0055] 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.

[0056] Figure 1 shows a tool system with a base 10 and a chisel holder 30 attached to it.

[0057] The lower part 10 has a connection side 11, which may have a contact surface, preferably concavely curved. 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 fastened to it, for example by means of a weld.

[0058] 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.

[0059] 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. It may be provided that at least one shoulder 13.3 is present in the area of ​​at least one of the side surfaces to form a material discharge area.

[0060] 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.

[0061] 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.

[0062] It is also possible that the lower part 10 has 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 one 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.

[0063] 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.

[0064] 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. 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, there are recesses 17 between the front support surfaces 15.1, 15.2 and the associated rear support surfaces 16.1, 16.2, which can be groove-like. 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.

[0065] 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).

[0066] 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.

[0067] 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.

[0068] 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, or arranged within, the insertion extension 18.1 to achieve a compact design. Figures 10 and 11 further show that a front shaft support surface 18.2 facing the front face 13.1 is formed within the plug receptacle 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. It is possible that the recess 18.3 extends from the underside, in particular the connection side 11, of the base body 13 in the direction of the longitudinal extent of the plug receptacle 18. In the recess 18.3 can accommodate a (not shown) shaped body, in particular a clamping sleeve, or a dowel pin or the like. The shaped body extends partially into the area of ​​the plug receptacle 18. This is more clearly visible in Figure 12.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] As described below, the support body 35 has a tool holder 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 plane ME of the tool holder 30 can be defined by the central longitudinal axis M and the socket axis 44.2.

[0077] 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. 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 tool holder 32. The bearing surface 31 is particularly preferably continuous.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] It is conceivable that the two front removal surfaces 41.1, 41.2 are connected to each other by means of a secondary surface 42. The secondary surface 42 penetrates the central longitudinal plane ME.

[0099] 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.

[0100] 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.

[0101] 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 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 bisector of this angle may be positioned such that it intersects the central longitudinal plane ME.

[0102] 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.

[0103] 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,

[0104] 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, respectively.

[0105] 43.2. However, an indirect transition is also conceivable, for example by means of a rounding 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] The drawings (see especially Figure 7) illustrate that the two transverse edges of the inclined surfaces 42.1 run at an angle of £ <90° in the direction 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.

[0110] Preferably, the inclined surfaces 42.1 are designed as planar 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. Alternatively, the two inclined surfaces 42.1 can be arranged in a V-shape relative to each other in a view along the longitudinal axis 44.2 of the insertion attachment and diverge 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 14) and / or diverge from the underside of the chisel holder 30 towards the top of the chisel holder 30 (see Figure 6).

[0111] 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.

[0112] 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.

[0113] The second middle section is located between the first and third shaft sections.

[0114] Advantageously, the extension of the first, lower shaft area in the direction of the plug-in longitudinal axis 44.2 may be at least 30% of the maximum length of the plug-in section 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.

[0115] Additionally or alternatively, the extension of the second, middle shaft area in the direction of the plug-in longitudinal axis 44.2 may be at least 10% of the maximum length of the plug-in 44 in this direction to ensure sufficient elongation of the plug-in 44 in the direction of the plug-in longitudinal axis 44.2.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] It is possible that the shaft extension 44.1 widens 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, it is possible that the shaft extension 44.1 widens the cross-section of the plug-in section 44, at least in some areas, in the transition to the two lateral inclined surfaces.

[0120] 42.1 widened. Additionally or alternatively, it may be provided that the shaft widening 44.1 widens the cross-section of the plug-in insertion 44 at least in the area of ​​the transition to the two front wear surfaces 41.1 , 41.2.

[0121] 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.

[0122] 44.1 to the support body 35 and preferably includes the greatest extent LE of the widening sides, as clearly shown in Figure 6.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] The stock extension 44.1 may form a rear stock support 48. The rear stock support 48 has two side contact surfaces 48.1, which are spaced apart from each other. In particular, the side contact surfaces 48.1 may be angled relative to each other in a V-shape.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] Preferably, the side contact surfaces 48.1 can be arranged at an angle to 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 can be arranged at an angle 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.

[0132] In one possible embodiment of a chisel holder 30, the angle between the side contact surfaces 48.1 may be selected to be in the range of 30° to 75°, preferably in the range of 35° to 70°, and particularly preferably in the range of 45° to 55°. Such a configuration is particularly recommended when a chisel holder 30 is provided with two flat rear cutting surfaces 43.1, 43.2 that 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 may preferably be angled relative to each other in the range of 30° to 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] The drawings illustrate that the overload contact surface 48.2 and / or the side contact surfaces 48.1 can transition at least partially into the rear wear surfaces 43.1, 43.2 or the single rear wear surface 43.1, 43.2. Figure 8 illustrates that the plug-in attachment 44 has a shaft section which preferably has 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 cylinder section 44.5 preferably aligns with the plug-in longitudinal axis 44.2 and is particularly preferably located in the central longitudinal plane ME.

[0137] Preferably, the cylinder section 44.5 connects to the shaft widening 44.1.

[0138] In a chisel holder 30 according to the invention, the widening sides of the shank widening 44.1 may transition laterally, at least partially, into the front and / or the 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.

[0139] 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.

[0140] 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.

[0141] 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°.

[0142] 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.

[0143] 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.

[0144] 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. Ausweislich Figur 9 kann es vorzugsweise so sein, dass die vordere Schaft- Anlagefläche 45 eine teilzylindrische Mantelfläche bildet. Hierbei ist es vorzugsweise so, dass die Anlage-Zylinderachse Z der teilzylindrischen Mantelfläche der vorderen Schaft-Anlagefläche 45 und die Steckansatz-Längsachse 44.2 miteinander einen Achsenwinkel q einschließen, der sich hin zum freien Ende des Steckansatzes 44 öffnet.

[0145] The axial angle q between the contact cylinder axis Z of the partially cylindrical outer surface of the front shaft contact surface 45 and the plug-in longitudinal axis 44.2 can be selected in the range between 2° and 10°, preferably in the range between 2° and 8°, to enable secure anchoring of the plug-in end 44 in the plug receptacle 18 of the lower part 10.

[0146] It should be noted again at this point 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 axis angle q, preferably in the range between 2° and 10°, particularly preferably between 2° and 8°.

[0147] 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.

[0148] 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. Figur 8 veranschaulicht, dass es vorgesehen sein kann, dass zumindest eine Seiten- Anlagefläche 48.1 der hinteren Schaftanlage 48 in der Schnittebene SE eine hintere Schnittkante 48.1.1 in der Schnittfläche SF bildet. Es kann vorgesehen sein, dass

[0149] 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°.

[0150] 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.

[0151] 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°.

[0152] 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.

[0153] 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.

[0154] A stress-optimized design is achieved in such a construction when a concave rounded transition of the plug-in section 44 is provided to guide the plug-in section 44 into the shaft extension 44.1. Additionally or alternatively, the shaft extension 44.1 can also be provided with a transition geometry featuring a relief groove 49 and / or a rounded surface, by which it transitions into the support body 35.

[0155] To mount the chisel holder 30 to the base 10, the plug-in extension 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 extension 44.

[0156] 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.

[0157] 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.

[0158] 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

[0159] 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.

[0160] 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.

[0161] 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. The overload contact surface 48.2 then comes into contact with the clamping surface 18.7. This limits the deflection of the clamping surfaces 18.5, 18.6 to prevent damage to the lower part 10 and to provide an additional support area for distributing the overload.

[0162] After the overload event has ended, the chisel holder 30 returns to its original position as shown in Figure 13.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] As the tool's operating 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. The use of the inclined surfaces 42.1, which face the lower part 10 in the area of ​​the recesses 17, creates a generous space for this wear (see Figure 3). This compensates for the wear. Thus, the tool holder 30 can continue to be reliably and correctly supported on the front and rear support surfaces 15.1, 15.2, 16.1, 16.2 of the lower part 10.

Claims

Claims 1. Lower part (10) for receiving a chisel holder (30), comprising a base body (13) which has a holder receptacle (14) for receiving the chisel holder (30), wherein the holder receptacle (14) has a plug-in receptacle (18), wherein the holder receptacle (14) has at least one front support surface (15.1, 15.2) which is arranged at least partially in front of and / or laterally to the plug-in receptacle (18), and wherein the holder receptacle (14) has at least one rear support surface (16.1, 16.2) which is arranged at least partially behind and / or laterally to the plug-in receptacle (18), characterized in that the base body (13) has two clamping surfaces (18.5, 18.6) of a rear overload support area (18.4) in the insertion area into the plug-in receptacle (18), and that the clamping surfaces (18.5, 18.6) each have one side of the base body (13) are facing.

2. Lower part (10) according to claim 1, characterized in that the clamping surfaces (18.5, 18.6) each have a flat surface portion, that these surface portions are angled relative to each other in a V-shape, and that these surface portions enclose an angle with each other preferably in the range between 45° and 100°, preferably between 50° and 90°, particularly preferably between 66° and 76°, or that these surface portions enclose an angle with each other in the range between 30° and 75°, preferably in the range between 35° and 70°, particularly preferably in the range between 45° and 55°, or that these surface portions enclose an angle with each other in the range between 37° and 87°, preferably in the range between 42° and 82°, particularly preferably in the range between 57° and 67°.

3. Lower part (10) according to claim 1 or 2, characterized in that the rear overload support area (18.4) has a securing surface (18.7) which is arranged between the two clamping surfaces (18.5, 18.6).

4. Lower part (10) according to claim 3, characterized in that both clamping surfaces (18.5, 18.6) enclose an angle with the securing surface (18.7), wherein these two angles are preferably equal, wherein it is preferably provided that the angle between the clamping surfaces (18.5, 18.6) and the securing surface (18.7) is selected in the range between 40° and 68°, preferably between 45° and 62.5°, particularly preferably between 52° and 57°.

5. Lower part (10) according to one of claims 3 or 4, characterized in that the two clamping surfaces (18.5, 18.6) each transition into the securing surface (18.7) via a rounding transition.

6. Lower part (10) according to one of claims 1 to 5, characterized in that the plug receptacle (18) has an insertion extension (18.1) in the area of ​​the upper side of the base body (13), which extends the cross-section of the plug receptacle (18) in the direction from the underside of the base body (13) towards the upper side of the base body (13) and radially outwards, and that the clamping surfaces (18.5, 18.6) and / or the locking surface (18.7) are arranged at least partially in the insertion extension (18.1) and limit it at least partially.

7. Lower part (10) according to claim 6, characterized in that the insertion extension (18.1 ) has side sections which extend laterally to the base body (13) following the two clamping surfaces (18.5, 18.6) and which extend in the direction from the rear (13.2) of the base body (13) towards the front (13.1 ).

8. Lower part (10) according to one of claims 1 to 7, characterized in that the rear support surface (16.1 , 16.2) transitions on both sides of the base body (13) into a front support surface (15.1 , 15.2) via a recess (17) recessed into the base body (13), which is preferably designed as a rounded transition, or that the rear support surfaces (16.1 , 16.2) each transition laterally to the base body (13) via a recess (17) recessed into the base body (13), which is preferably designed as a rounded transition, into a front support surface (15.1 , 15.2), and that in the area of ​​the recesses (17) a clamping surface (18.5, 18.6) of the rear overload support area is arranged at least partially.

9. Lower part (10) according to one of claims 1 to 8, characterized in that at least one front shaft support surface (18.2) of a front shaft assembly is provided in the plug receptacle (18) and facing the underside of the base body (13), that the front shaft support surface (18.2) is arranged on the side of the plug receptacle (18) opposite the rear overload support area (18.4), wherein it is preferably provided that the front shaft support surface (18.2) is provided by means of a recess provided in the base body (13). (18.3) is divided into two sub-areas.

10. Lower part (10) according to one of claims 1 to 9, characterized in that the front shaft support surface (18.2) has a partial cylindrical surface of a hollow cylinder, and that the cylinder axis of this hollow cylinder with the clamping surfaces (18.5, 18.6) of the overload support area (18.4) and / or the overload contact surface (18.4) of the overload support area (18.4) encloses a clamping angle in the range between 5° and 15°, preferably in the range between 9° and 12°.

11. Lower part (10) according to one of claims 1 to 10, characterized in that the two front support surfaces (16.1, 16.2) are separated from each other at the front by means of a recess (15.3), wherein it is preferably provided that the recess (15.3) is opposite the overload support area (18.4) is ordered.

12. Lower part (10) according to one of claims 1 to 11, characterized in that the rear support surfaces (16.1, 16.2) are separated from each other by means of a transition section (16.3) recessed into the base body (13) and that the The transition section (16.3) is located in the area of ​​the rear overload support area (18.4).

13. Lower part (10) according to claim 12, characterized in that the transition section (16.3) has a surface area set back from the rear support surfaces (16.1 ,16.2) which at least partially transitions into the clamping surfaces (16.1 , 16.2) and / or the securing surface (18.7).

14. Tool combination comprising a lower part (10) according to one of claims 1 to 13 and a chisel holder (30), wherein the chisel holder (30) is inserted into the socket (18) of the lower part (10) with a plug-in extension (44) and the chisel holder (30) is supported with cutting surfaces (41.1 , 41.2 , 43.1 , 43.2) on the support surfaces (15.1 , 15.2 , 16.1 , 16.2) of the lower part (10) and wherein the chisel holder (30) has a rear shank support (48) with side contact surfaces (48.1 ) which are opposite the clamping surfaces (18.5, 18.6).

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