EP2646653B1 - Chisel holder - Google Patents

Description

The invention relates to a chisel holder for a soil cultivation machine, in particular a road milling machine, a mining machine or the like, with a support body to which a plug attachment is connected directly or indirectly to one plug attachment side, the support body having two first and two second removal surfaces which are at an angle to each other stand, and wherein the support body has a machining side which has a chisel receptacle.

From the U.S. 3,992,061 a chisel holder is known which forms a support body with an integrally molded plug-in attachment. The support body is penetrated by a cylindrical bore designed as a chisel receptacle. A machining tool, in the present case a round shank chisel, can be inserted into the chisel holder. The support body has two removal surfaces at an angle to one another, which serve to support on corresponding support surfaces of a base part. The base part has a plug-in receptacle into which the chisel holder with its plug-in attachment can be inserted interchangeably. In the assembled state, the removal surfaces of the chisel holder rest on the support surfaces of the base part. In order to maintain a fixed area allocation, a clamping screw is used which clamps the plug-in attachment in the plug-in receptacle of the base part.

During the processing operation, the processing tool engages in the substrate to be processed. In doing so, high machining forces are transmitted. These are transferred from the machining tool to the chisel holder. There they are passed on to the base part via the removal surfaces.

During the machining operation, the direction of force and also the amount of force vary under otherwise identical conditions, solely due to the fact that the machining tool forms a chip (comma chip) that thickens from the entry point to the exit point. In addition, the direction of force varies and the amount depending on various parameters such as the milling depth, the feed rate, the material to be processed, etc. The in the U.S. 3,992,061 The illustrated embodiment of a chisel holder cannot dissipate the machining forces with a sufficiently long service life, particularly at high feed speeds. In particular, the abraded surfaces quickly deflect. In addition, the plug attachment is also exposed to high bending stresses and there is a risk that a plug attachment breakage will occur after component fatigue. From the DE 34 11 602 A1 another chisel holder is known. This has a support body which is supported via projections on a base part. A clamping part is formed on the support body and can be clamped to the base part via wedge connections.

The U.S. 4,828,327 shows a chisel holder which is designed as a solid block and is penetrated by a chisel holder. Furthermore, the chisel holder has a threaded receptacle which is in alignment with a screw receptacle of a base part. A fastening screw can be passed through the screw receptacle and screwed into the threaded receptacle of the chisel holder. When the fastening screw is tightened, the chisel holder is drawn into an L-shaped recess in the base part and supported there on support surfaces. The chisel holders described above are usually arranged protruding on the surface of a milling drum tube. During the machining operation, transverse forces also occur which act transversely to the tool feed direction. These transverse forces can with the in the U.S. 4,828,327 bit holders described are not always received with sufficient stability. In particular, these transverse forces are transmitted into the fastening screw, which is then subjected to strong shear stress.

US 2008/0093912 A1 discloses a chisel holder which has a chisel receptacle in the area of a machining side. A chisel can be set in this chisel holder. The chisel holder can be attached to a base part attach, wherein the base part is connected to a rotary body of a milling machine. A separate holder is used to fix the chisel holder on the base part. Using this holder and a clamping piece, as well as a suitable clamping screw, the chisel holder can be clamped to the base part.

WO 2010/051593 A1 discloses another tool combination in which a chisel holder can be connected to a base part. The chisel holder again has a chisel receptacle for a chisel. In this solution, too, a separate holder is used with which the chisel holder can be fixed on the base part. In the assembled state, the chisel with a chisel shank passes through both a receiving bore in the chisel holder and a receiving bore in the holder and thus enables the chisel holder to be fastened to the base part without screws.

Out DE 10 2005 017 760 A1 a tool combination with a chisel holder and a base part emerges as known. The chisel holder has two surfaces which are set at an angle to one another and which are provided on a plug-in attachment. These surfaces can also be brought to bear against inclined opposing surfaces of the base part in order to be able to bring about a wedge-shaped bracing of the chisel holder on the base part with the aid of a screw connection.

In the DE 10 2005 010 678 A1 describes a tool holder system with a chisel holder and a base part. The chisel holder has two support surfaces which are arranged at an angle to one another. In the assembled state, one of the two support surfaces is supported directly on a counter surface of a base part. The second support surface rests on the base part with an elastic layer in between. A similar design also comes from the DE 10 2005 055 544 A1 as known. In this tool system, the chisel holder is supported with respect to the base part by means of elastic elements, namely a heavy-duty clamping sleeve.

U.S. 6,619,756 D1 discloses a tool system in which a toothing is provided in the interface area between a chisel holder and a base part. The setting angle of the chisel holder in relation to the base part can be varied via this toothing.

It is the object of the invention to create a chisel holder of the type mentioned at the beginning, which is characterized by increased stability.

This object is achieved by a chisel holder according to claim 1. Further advantageous configurations are described in the dependent claims.

According to the invention, the support body has two first and two second removal surfaces, the two first removal surfaces being at an angle to one another and the two second removal surfaces being at an angle to one another. Furthermore, the chisel holder according to the invention is characterized in that the first removal surfaces diverge from the plug attachment side in the direction of the machining side and that the second removal surfaces diverge from the plug attachment side towards the processing side. The removal surfaces therefore form a prism-shaped support in the area of the plug-in attachment side and here enable a reliable transmission of force from the chisel holder to the base part. This direct support also reduces the load on the plug-in attachment during the machining operation. The arrangement of the removal surfaces according to the invention also takes into account the force profile that typically varies in soil cultivation tools, so that a longer service life can be achieved overall. According to the invention, it is also provided that the first removal surfaces are arranged at least partially in front of the plug-in attachment in the feed direction and the second removal surfaces in the feed direction at least partially behind the plug-in attachment. This construction takes particular account of the varying force curve during the machining operation, and the plug-in attachment is further relieved of machining forces.

According to a preferred embodiment of the invention, it can be provided that the surface normals of the first and / or second removal surfaces each point to their chisel holder side as seen in the tool advance direction. Accordingly, when the chisel holder is used on a milling drum tube, for example, the removal surfaces are arranged inclined to the axis of rotation of the milling drum tube. With this arrangement, transverse forces that arise during the machining operation can also be reliably absorbed, which leads to a further optimization of the service life.

The first and / or second removal surfaces particularly preferably enclose an obtuse angle, in particular in the range between 100 ° and 140 °. These

Angular arrangement guarantees that the chisel holder can be easily inserted into a base part even in confusing places and in rough construction site conditions, so that a reliable assignment of the removal surfaces to the support surfaces of the base part is guaranteed. In addition, it is prevented that jamming occurs even after a long period of use, during which the abraded surfaces may work off a little compared to the supporting surfaces. This means that the chisel holder can always be easily changed. In addition, this angular inclination of the first and / or second removal surfaces guarantees reliable removal of the machining forces. The opening angle depicts the wide range of directions from which the transverse forces can act in the course of work access and through changes in the other parameters.

If this angle range between the first removal surfaces is particularly preferably between 100 ° and 120 ° and / or the angle range between the second removal surfaces is between 120 ° and 140 °, then the tool system is optimized in particular for use in road milling applications and the load conditions that occur .

A chisel holder according to the invention can be designed in such a way that the removal surfaces are at least partially connected to one another via a transition cut in the area of the plug attachment side. Accordingly, the abraded surfaces do not meet at the apex, so that there is no sharp-edged angular transition that can be damaged. In addition, with the transition section and in conjunction with the base part, a follow-up area can also be created. Accordingly, when the removal surfaces and / or the support surfaces of the base part work away, the chisel holder can continuously move into this readjustment space, the removal surfaces always remaining in contact with the support surfaces. In particular, the planar system is retained even if the chisel holder has to be exchanged for a new one on the existing base part, and that too several times.

Particularly preferably, the plug-in attachment is at least partially connected to the plug-in attachment side in the area of the removal surfaces. This enables the removal surfaces to be assigned directly to the plug-in attachment, which leads to a smaller component size and also offers an optimized flow of forces.

A chisel holder according to the invention can be characterized in that the longitudinal axis of the plug-in attachment and the central longitudinal axis of the prisms formed by the first or second removal surfaces enclose an angle in the range between 100 ° and 130 °. Here, too, an optimal flow of forces is achieved through this design feature.

It is preferably provided that the first removal surfaces form, at least in some areas, the underside of a front apron. The front apron usually covers a front area of the base part and thus protects it from wear. The fact that the front apron is now also used to attach the removal surfaces results in a compact design and the chisel holder can be easily manufactured.

It can furthermore be provided that the second removal surfaces form, at least in some areas, the underside of a rear support attachment. Under certain operating conditions, a large part of the forces is transmitted via the rear support attachment. In a design that provides a chisel holder, for example a bore, on the chisel holder to accommodate a machining tool, in particular a round shank chisel, it is optimally provided that the central longitudinal axis of the chisel holder is arranged at least in some areas between the removal surfaces. In this way, on the one hand, a good distribution of forces of the machining forces introduced via the machining tool on both removal surfaces can be achieved. Furthermore, the chisel holder can also be positioned in different orientations relative to a milling drum tube, while the reliable transmission of force is maintained.

It has been shown that an optimal force distribution of the forces to be removed into longitudinal and transverse forces is achieved if it is provided that the angle between the central longitudinal axis of the prism of the first removal surfaces and the central longitudinal axis of the chisel holder is in the range between 40 ° and 60 °, particularly preferably between 45 ° and 55 °, and / or that the angle between the central longitudinal axis of the prism of the second removal surfaces and the central longitudinal axis of the chisel holder is in the range between 70 ° and 90 °, particularly preferably between 75 ° and 85 °. These angular positions also guarantee that the chisel holder does not reach an excessively large construction width due to the inclination of the removal surfaces, and thus a material-optimized construction is guaranteed.

According to a further embodiment variant of the invention, it can be provided that the chisel receptacle merges into a flushing channel, and that the flushing channel emerges at least in some areas in the area between the second removal surfaces. The flushing channel is therefore arranged in such a way that the abraded surfaces do not meet at a point.

Particularly preferably, the first and the second removal surfaces each form a removal surface pair, in which the removal surfaces are each inclined in a V-shape. The V-shaped inclination of the removal surfaces creates prisms in the sense of tool device construction. These two prisms guarantee a stable support of the chisel holder against the base part. The prisms formed by the first or second removal surfaces have a central longitudinal axis. This central longitudinal axis lies in the bisector plane that is formed between the two removal surfaces.

If it is additionally provided that a first removal surface of the first removal surface pair and a second removal surface of the second removal surface pair are inclined to each other at an angle, preferably in the range between 120 ° and 160 °, and the removal surface pairs form a support area, then the chisel holder can be in a Correspondingly designed angled chisel holder receptacle of the base part can also be used and stably supported therein. A corresponding arrangement applies to the remaining surfaces of the first and second pairs of ablation surfaces, ie the two prisms are set at an angle to one another and in turn form a prism. The opening angle represents the wide range of directions from which the longitudinal forces can act in the course of tool engagement and through changes in the other parameters.

Furthermore, it is conceivable that the central longitudinal axis of the plug-in attachment is in the angular range from -10 ° to + 10 ° to the bisector of the first and / or second pair of removal surfaces. In this way, when the chisel holder is clamped to the base part, a uniform pre-tension is applied. It is particularly preferred that the central longitudinal axis of the plug-in attachment is in the angular range of -2 ° to + 2 ° to the bisector of the first and / or second pair of removal surfaces.

A chisel holder according to the invention can also be characterized in that the surface normals of the first and / or second removal surfaces run inclined to the feed direction, so that transverse forces can be reliably transmitted.

A particularly preferred embodiment of the invention is such that a plane receiving the angle bisector is arranged between the first and / or the second removal surfaces, and that the plug-in attachment is arranged symmetrically to this plane. Due to this symmetrical design, the chisel holder can also be attached to different mounting positions of a milling drum tube or the like, or this has the advantage that only one variant is required and does not have to work with left and right chisel holders.

In order to relieve the plug attachment and protect it from fatigue fractures, it is provided according to a variant of the invention that the connection area of the plug attachment to the support body is arranged at least 80% in the area of the removal surface pair formed by the first removal surfaces.

Figur 1

eine Kombination eines Basisteils und eines Meißelhalters in perspektivischer Seitenansicht;

Figur 2

die Darstellung gemäß Figur 1 in Explosionsansicht;

Figur 3

den Meißelhalter gemäß den Figuren 1 und 2 in Frontansicht;

Figur 4

den Meißelhalter gemäß den Figuren 1 bis 3 in Rückansicht;

Figur 5

den Meißelhalter gemäß den Figuren 1 bis 4 in Seitenansicht von links;

Figur 6

die Darstellung gemäß Figur 5 im Vertikalschnitt durch die Mittelquerebene des Meißelhalters;

Figur 7

den Meißelhalter gemäß den Figuren 1 bis 6 in Seitenansicht von rechts und teilweise im Schnitt;

Figur 8

einen in Figur 5 mit VIII-VIII markierten Schnittverlauf;

Figur 9

einen in Figur 7 mit IX-IX markierten Schnittverlauf;

Figur 10

einen in Figur 7 mit X-X markierten Schnittverlauf;

Figur 11

die Werkzeugkombination gemäß Figur 1 in Draufsicht;

Figur 12

einen in Figur 11 mit XII-XII markierten Schnittverlauf;

Figur 13

den Meißelhalter gemäß Figur 5 in Ansicht von vorne;

Figur 14

den Meißelhalter in Ansicht von hinten; und

Figur 15

den Meißelhalter in einer gedrehten Seitenansicht.

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

Figure 1

a combination of a base part and a chisel holder in a perspective side view;

Figure 2

the representation according to Figure 1 in exploded view;

Figure 3

the chisel holder according to the Figures 1 and 2 in front view;

Figure 4

the chisel holder according to the Figures 1 to 3 in rear view;

Figure 5

the chisel holder according to the Figures 1 to 4 in side view from the left;

Figure 6

the representation according to Figure 5 in vertical section through the central transverse plane of the chisel holder;

Figure 7

the chisel holder according to the Figures 1 to 6 in side view from the right and partially in section;

Figure 8

one in Figure 5 section line marked VIII-VIII;

Figure 9

one in Figure 7 cutting line marked with IX-IX;

Figure 10

one in Figure 7 cutting line marked with XX;

Figure 11

the tool combination according to Figure 1 in plan view;

Figure 12

one in Figure 11 with XII-XII marked cutting course;

Figure 13

the chisel holder according to Figure 5 in front view;

Figure 14

the chisel holder in a view from the rear; and

Figure 15

the chisel holder in a rotated side view.

Figure 1 shows a tool combination consisting of a base part 10 and a chisel holder 20. The chisel holder 20 is interchangeably connected to the base part 10. The base part 10 has a solid base body 13 which has a lower connection side 11. This connection side 11 has a concave curvature, the curvature being selected according to the outer diameter of a milling drum tube. The base part 10 can thus be placed with its connection side 11 on the outside of the milling drum tube and welded to it. The base body 13 has a projection on the front side, which is delimited on the side by inclined surfaces 14 and on the front side by inclined surfaces 15. The inclined surfaces 15 are set at an angle to one another and the inclined surfaces 14 adjoin the inclined surfaces 15 at an angle. This results in an arrow-shaped geometry of the base part 10 on the front side, which leads to a better clearing effect of the base part 10.

As the Figure 2 illustrates, a chisel holder receptacle 16 with a plug-in receptacle 16.7 is incorporated into the base part 10. The plug-in receptacle 16.7 penetrates the base body 13 completely and thus opens into the connection side 11. A threaded receptacle 18 is incorporated into the base part 10, which opens into the plug-in receptacle 16.7 (see FIG Figure 12 ). The chisel holder receptacle 16 has first support surfaces 16.1 and second support surfaces 16.2. The first support surfaces 16.1 form a first support surface pair and the second support surfaces 16.2 form a second support surface pair. The supporting surfaces 16.1, 16.2 are each arranged at an angle to one another in each supporting surface pair. Furthermore, the support surfaces 16.1 are each set at an angle to the support surfaces 16.2, so that an obtuse-angled chisel holder receptacle 16 results. In the transition area between the individual support surfaces 16.1 and 16.2, additional spaces 16.3, 16.4, 16.5 are provided in the form of recesses. In the area of the supplementary space 16.5 is Furthermore, a recess 16.6 is provided, which creates a transition from the chisel holder receptacle 16 to the threaded receptacle 18.

How Figure 2 As can further be seen, a surface 17 is formed around the entry into the threaded receptacle 18, which is laterally bounded by inclined surfaces, the inclined surfaces opening in a divergent manner towards the rear of the base part 10. In this way, the surface 17 and thus a tool holder 43 of a pressure screw 40 can be easily cleaned. The pressure screw 40 has a threaded section 41 with which it can be screwed into the threaded receptacle 18. Furthermore, the pressure screw 40 is designed with a pressure shoulder 42 in the form of a truncated conical pin which is integrally formed on the threaded section 41.

How Figure 2 further shows, the chisel holder 20 can be connected to the base part 10. The chisel holder 20 has a support body 21 which is equipped with an apron 22 on the front. The apron 22 carries a web 22.1, formed in one piece, which rises upwards from the apron 22. A projection 23, which terminates in a cylindrical section 24, is also coupled in one piece to the support body 21. The cylindrical section 24 is provided with wear markings, which in the present case are designed as circumferential grooves 26. The cylindrical section 24 terminates with a support surface 25 which concentrically surrounds the bore entry of a chisel receptacle 27. The chisel receptacle 27 merges into the support surface 25 via a bevel-shaped insertion section 27.1.

How Figure 4 shows, the chisel receptacle 27 is designed as a through hole. The support body 21 is provided with a rear recess which serves as a flushing channel 28. The flushing channel 28 consequently opens the chisel receptacle 27 radially outward in the area of its bore exit. Thus, debris particles that have entered the chisel receptacle 27 during the use of the tool can be conveyed out radially through the flushing channel 28.

Figure 3 shows that the support body 21 has first removal surfaces 29.1 in the area of the skirt 22. These removal surfaces 29.1 are at an obtuse angle ε ₁ to one another (see Figure 13 ) and are connected to one another via a transition section 29.2. The angle ε ₁ between the first removal surfaces 29.1 corresponds to the angle between the first support surfaces 16.1 of the base part 10.

Figure 4 shows that the back of the support body 21 has downwardly facing second removal surfaces 29.4. The second removal surfaces 29.4 are at an angle ε ₂ to one another (see Figure 14 ), the angle ε ₂ between the second removal surfaces 29.4 here also corresponding to the angle between the second support surfaces 16.2 of the base part 10. While the first removal surfaces 29.1 merge into one another by means of the transition section 29.2, a transition area is formed between the second removal surfaces 29.4 by the flushing channel 28 and a transition section 29.5.

The removal surfaces 29.1 and 29.4 each form pairs of removal surfaces in the form of a prism. These prisms have a central longitudinal axis MLL which is formed in the bisector plane between the two first removal surfaces 29.1 and the second removal surfaces 29.4. In the Figures 13 and 14 these planes bisecting the angle are marked with WE. The central longitudinal axis is indicated there with MLL, wherein the central longitudinal axis MLL can in principle be at any position within the bisector plane.

The Figures 3 and 4 show in conjunction with the Figures 13 and 14 that the first removal surfaces 29.1 and also the second removal surfaces 29.4 diverge starting from the plug-in attachment side towards the processing side. In the present example, the surface normals correspondingly converge on the removal surfaces 29.1, 29.4 from the plug-in attachment side to the processing side. The surface normals therefore converge in the area of the tool engagement point in which the machining forces are introduced into the tool system.

The use of two pairs of removal surfaces, each with the first and second removal surfaces 29.1 and 29.4, optimally takes into account the variance of the machining forces during tool engagement. A comma span is created while the tool is being used. With this chip formation, not only the amount of force changes, but also the direction of force. Accordingly, at the beginning of the tool engagement, the machining force acts in such a way that it is more likely to be diverted via the pair of removal surfaces formed by the first removal surfaces 29.1. As the tool engagement progresses, the direction of the machining force rotates and is then increasingly diverted via the pair of removal surfaces formed by the second removal surfaces 29.4. Accordingly, the angle γ '(see Figure 5 ) be designed between the pairs of removal surfaces so that the variance of the machining force is taken into account, and this machining force always acts in the prisms formed by the pairs of removal surfaces.

In the Figures 3 and 9 the central transverse plane MQ of the chisel holder 20 is marked. The chisel holder is mirror-symmetrical to this central transverse plane MQ so that it can be installed on a milling drum as a right or left part.

In the Figures 3 and 4 the feed direction is marked with the usual arrows. The bit holder sides are arranged transversely to the feed direction. The surface normals of the removal surfaces 29.1 and 29.4 thus each point to their side of the chisel holder viewed in the tool feed direction and downwards, as shown in FIGS Figures 3 and 4 becomes clear. In Figure 5 this fact is shown again in a side view.

However, the processing force does not only act in the direction of the image plane Figure 5 , but rather also in the transverse direction. These transverse force components are then _{ideally absorbed via the angular inclination (ε 1} , ε ₂ ) of the removal surfaces 29.1, 29.4. Since the machining forces scatter less in the transverse direction at the beginning of the tool engagement, the angle ε _{1 can} also be selected to be smaller than ε ₂ .

Figure 5 further shows that a plug-in attachment 30 is integrally formed on the support body 21 and merges into the first removal surfaces 29.1 and the second removal surfaces 29.4 via a rounded transition 29.3. The plug-in attachment 30 is arranged in such a way that it essentially, in the present case around 90%, adjoins the support body 21 in the region of the first removal surfaces 29.1. The plug-in attachment 30 carries two contact surfaces 31.1 on the front. These are how Figure 3 can be seen, designed as convex cylinder surfaces. The contact surfaces 31.1 extend longitudinally and parallel to the central longitudinal axis M (see FIG. Figure 5 ) of the plug-in extension 30. The contact surfaces 31.1 are therefore also parallel to one another. The contact surfaces 31.1 are arranged at a distance from one another in the circumferential direction of the plug-in attachment 30. They have the same radius of curvature and are arranged on a common pitch circle. The radius of curvature corresponds to half the pitch circle diameter. A recess 31.2 is provided in the area between the contact surfaces 31.1, the contact surfaces 31.1 running parallel to the recess 31.2. The recess can have a wide variety of shapes, for example it can be a simple surface. In the present exemplary embodiment, the recess 31.2 forms a depression that is concave between the contact surfaces 31.1. The concavity is designed in such a way that a partially cylindrical geometry results. The recess 31.2 does not extend over the entire length of the plug-in attachment 30, but only over a partial area, like this Fig. 13 reveals. The recess 31.2 is open to the free end of the plug-in attachment 30, that is, in the plug-in direction. The recess 31.2 also opens radially outwards without undercuts. Opposite the contact surfaces 31.1, the plug-in extension 30 has a pressure screw receptacle 32 on the rear side, which is equipped with a pressure surface 32.1.

Figures 6 and 9 illustrate that the recess 31.2 between the two contact surfaces 31.1 has a concavely curved geometry, and in particular can form a partially cylindrical cross section.

In the Figures 7 to 10 the design of the plug-in attachment 30 is detailed. Figure 9 clearly shows the concave bulge of the recess 31.2, which is attached to the convex contact surfaces 31.1 adjoins. Out Figure 10 it becomes clear that the plug-in attachment 30 has a substantially circular or oval cross-sectional configuration in its area adjoining the contact surfaces 31.1.

Figure 8 illustrates the area of the pressure screw receptacle 32, the pressure surface 32.1 being set at an angle δ to the central longitudinal axis M of the plug-in attachment 30. This setting angle δ is preferably in the range between 20 ° and 60 ° in order to achieve an optimal pull-in effect of the chisel holder 20.

Figure 7 also shows that the pressure surface 32.1 is arranged at a distance A from the connection area of the plug-in attachment 30 to the support body 21.

The contact surfaces 31.1 are arranged at a distance B from the connection area of the plug-in attachment 30 to the support body 21. The centroid of the contact surfaces 31.1 is arranged at a distance C from the centroid of the pressure surface 32.1.

To mount the chisel holder 20 in the base part 10, the plug-in attachment 30 is inserted into the plug-in receptacle 16.7. The insertion movement is limited by the first and second removal surfaces 29.1, 29.4, which abut against the first and second support surfaces 16.1, 16.2.

As the Figures 1 and 12th can be seen, the assignment is made in such a way that the transition section 29.2 is above the supplementary space 16.4, the supplementary space 16.5 is bridged by the transition section 29.5 and the lateral supplementary spaces 16.3 are bridged by the angular area between the first and second removal surfaces 29.1, 29.4 is formed. The spacing of the bit holder 20 in the area of these readjusting spaces 16.3, 16.4, 16.5 ensures that the chisel holder 20 can move into the readjusting spaces 16.3, 16.4, 16.5 during the machining operation when the removal surfaces 29.1, 29.4 and / or the support surfaces 16.1 , Process 16.2. This applies in particular when the chisel holder 20 is worn in the existing base part 10 can be exchanged for new ones. To fix the prescribed installation state, the pressure screw 40 is screwed into the threaded receptacle 18. The pressure shoulder 42 presses with its flat end surface onto the pressure surface 32.1 and thus causes a pull-in force which acts in the direction of the central longitudinal axis M of the plug-in attachment 30. At the same time, however, the pressure screw 40 is also positioned at an angle to the central longitudinal axis M of the plug-in attachment 30 that a clamping force acting in the direction towards the front is also introduced into the plug-in attachment 30. This clamping force is transmitted via the contact surfaces 31.1 into the corresponding concave counter surface of the cylindrical section of the plug-in receptacle 16.7. The spacing of the contact surfaces 31.1 via the recess 31.2 guarantees that the plug-in attachment 30 is reliably fixed via the two support areas formed laterally by the contact surfaces 31.1. In this way, the surface pressures that occur are kept low, in particular also over the two contact surfaces 31.1, which leads to a reliable fixation of the plug-in attachment 30.

Because the chisel holder 20 can be readjusted in the readjustment spaces 16.3, 16.4, 16.5 in the event of wear, effective wear compensation can be made, with the removal surfaces 29.1, 29.4 projecting beyond the support surfaces 16.1, 16.2 at every point, so that in the event of wear, the Support surfaces 16.1, 16.2 are worn evenly without creating a so-called beard or burr. This configuration is particularly advantageous when the base part 10, as is usually required, has a service life that lasts for several life cycles of the bit holders 20. Unworn chisel holders 20 can then always be securely clamped and held on a partially worn base part 10. The repair of a machine in which the tool system formed from the base part 10 and chisel holder 20 is used is thus also simple. A large number of tool systems are usually mounted on such a machine, for example a road milling machine or a surface miner. The base part is usually welded onto the surface of a milled roller tube. If all or some of the chisel holders 20 are worn, they can simply be replaced with new ones that have not been worn or partially worn chisel holders 20 (which can be used for rough finishing work, for example) are exchanged.

When replacing, the pressure screw 40 is first loosened. The worn chisel holder 20 with its plug-in attachment 30 can then be pulled out of the plug-in receptacle 16.7 of the base part 10 and removed. The new (or partially worn) chisel holder 20 is then inserted with its plug-in attachment 30 into the plug-in receptacle 16.7 of the base part 10. If necessary, the pressure screw 40 can now be replaced with a new one. It is then screwed into the base part 10 and braced with the chisel holder 20 in the manner described above.

Figure 12 shows that the base part 10 carries a projection 50 which protrudes into the plug-in receptacle 16.7. In the present case, this projection 50 is formed by a cylinder pin which is driven into a partially cylindrical recess 19 from the connection side 11. The partially cylindrical recess 19 surrounds the cylinder pin by more than 180 ° of its circumference, so that it is held captive. The area of the cylindrical pin protruding into the chisel receptacle 27 engages in the recess 31.2 between the contact surfaces 31.1. When inserting the plug-in attachment 30 into the plug-in receptacle 16.7, the projection 50 reliably threads into the recess 31.2, which is open towards the free end of the plug-in attachment 30. An alignment of the chisel holder 20 with respect to the base part 10 is thus achieved. This alignment guarantees that the first and second removal surfaces 29.1, 29.4 now come to rest precisely on the support surfaces 16.1, 16.2, so that incorrect assembly is ruled out. Furthermore, the projection 50 and the geometrically adapted recess 31.2 in the form of a key-lock principle prevent an incorrect chisel holder 20 from being accidentally installed on the base part 10.

The angular relationships of the chisel holder 20 according to the invention will be discussed in greater detail below.

Figure 5 shows that the central longitudinal axis 24.1 of the chisel receptacle 27 is at an angle α or ϕ to the longitudinal alignment of the transition section 29.2 or 29.5 and thus also to the central longitudinal axis MLL of the prism formed by the first removal surfaces 29.1 and / or the second removal surfaces 29.4. The angle α can be between 40 ° and 60 ° or ϕ in the range between 70 ° and 90 °.

Figure 5 further shows that when the removal surfaces 29.1 and 29.4 are projected into a plane transverse to the feed direction (projection correspondingly Figure 5 ) the removal surfaces 29.1 and 29.4 are angled to one another at an angle γ in the range between 40 ° and 60 °, or that the opening angle between the
Transition sections 29.2 and 29.5 in the longitudinal direction according to Figure 5 is between 120 ° and 140 °. Correspondingly, the angle γ 'between the central longitudinal axes MLL of the two prisms formed by the removal surfaces 29.1 and 29.4 (removal surface pairs) is in the range between 120 ° and 140 °. Furthermore, with such a projection of the removal surfaces 29.1, 29.4, the first removal surfaces 29.1 are at an angle β and the second removal surfaces 29.4 are at an angle μ to the central longitudinal axis M of the plug-in attachment 30. The same applies here to the central longitudinal axes MLL of the prisms. The angles β and μ can be in the range between 100 ° and 130 °, preferably in the range between 110 ° and 120 °.

Figure 13 shows that the first removal surfaces 29.1 enclose an angle ε ₁ . This angle ε ₁ should preferably be in the range between 100 ° and 120 °. The bisector of this angle ε ₁ lies in a plane and Figure 13 shows that the plug attachment 30 is arranged symmetrically to this plane.

In the same way, the rear, second removal surfaces 29.4 are also made corresponding to one another at an angle ε ₂ , as is the case here Figure 14 shows. However, the angle ε ₂ can deviate from the angle ε ₁ and in the present exemplary embodiment can be between 120 ° and 140 ° and the plug-in attachment 30 is also arranged and equipped symmetrically to the bisector plane of this angle ε _2.

Figure 15 shows that a first removal surface 29.1 of the first removal surface pair and a second removal surface 29.4 of the second removal surface pair are positioned at an angle ω to one another and form a support area.

Claims (18)

1. Bit holder for a soil working machine, in particular a road milling machine, with a support member (21), to which an insertion projection (30) is connected indirectly or directly on an insertion projection side, wherein the support member (21) has two first and two second bearing surfaces (29.1, 29. 4), the two first bearing surfaces (29.1) being at an angle (ε1) to one another, the two second bearing surfaces (29.4) being at an angle (ε2) to one another, and the support member (21) having a working side facing away from the insertion projection, which working side has a bit receptacle (27),
   wherein the first bearing surfaces (29.1) diverge from the insertion projection side towards the working side,
   wherein the second bearing surfaces (29.4) diverge from the insertion projection side in the direction towards the working side,
   and wherein the two first bearing surfaces (29.1) are arranged at least partially in front of the insertion projection (30) in the tool advance direction (v) and the two second bearing surfaces (29.4) are arranged at least partially behind the insertion projection (30) in the tool advance direction (v).
2. Bit holder according to claim 1,
   characterized in
   that the surface normals of the first and/or second bearing surfaces (29.1, 29.4) each point to their respective toolholder side viewed in the tool advance direction (v).
3. Bit holder according to claim 1 or 2,
   characterized in
   that the first and/or second bearing surfaces (29.1, 29.4) enclose an obtuse angle (ε1, ε2), in particular in the range between 100° and 140°, in particular preferably the first bearing surfaces (29.1) are set in the range between 100° and 120° relative to one another, and/or in that the second bearing surfaces (29.4) are set in the range between 120° and 140° relative to one another.
4. Bit holder according to one of the claims 1 to 3,
   characterized in
   that the bearing surfaces (29.1, 29.4) are connected to one another in the region of the insertion projection side at least locally via a transition segment (29.2, 29.5).
5. Bit holder according to one of the claims 1 to 4,
   characterized in
   that the insertion projection (30) is at least partially connected to the insertion projection side in the region of the bearing surfaces (29.1, 29.4).
6. Bit holder according to one of the claims 1 to 5,
   characterized in
   that the longitudinal axis of the insertion projection (30) and the longitudinal center axis (MLL) of the prisms formed by the first or second bearing surfaces (29.1, 29.4) enclose an angle (β, µ) in the range between 100° and 130°.
7. Bit holder according to any one of claims 1 to 6,
   characterized in
   that the first bearing surfaces (29.1) form, at least locally, the underside of a front skirt (22).
8. Bit holder according to one of the claims 1 to 7,
   characterized in
   that the second bearing surfaces (29.4) form, at least locally, the underside of a rearward support projection.
9. Bit holder according to one of claims 1 to 8,
   characterized in
   that the central longitudinal axis (24.1) of the bit receptacle (27) is arranged, at least locally, between the first and/or second bearing surfaces (29.1, 29.4).
10. Bit holder according to one of the claims 1 to 9,
    characterized in
    that the angle (α) between the longitudinal center axis (MLL) of the prism of the first bearing surfaces (29.1,) and the central longitudinal axis (24.1) of the bit receptacle (27) is in the range between 40° and 60°, particularly preferably between 45° and 55°.
11. Bit holder according to any one of claims 1 to 10,
    characterized in
    that the angle (ϕ) between the central longitudinal axis of the prism of the second bearing surfaces (29.4) and the central longitudinal axis (24.1) of the bit receptacle (27) is in the range between 70° and 90°, particularly preferably between 75° and 85°.
12. Bit holder according to any one of claims 1 to 11,
    characterized in
    that the bit receptacle (27) merges into a flushing conduit (28), and in that the flushing conduit (28) emerges at least locally in the region between the second bearing surfaces (29.4).
13. Bit holder according to one of the claims 1 to 12,
    characterized in
    that the first and the second bearing surfaces (29.1, 29.4) each form a pair of bearing surfaces, in which the bearing surfaces (29.1 to 29.1 and 29.4 to 29.4) are each set in a V-shape relative to one another.
14. Bit holder according to claim 13,
    characterized in
    that in each case a first bearing surface (29.1) of the first pair of bearing surfaces and a second bearing surface (29.4) of the second pair of ablation surfaces are set at an angle (ω) to one another, preferably in the range between 120° and 160°, and form a support region.
15. Bit holder according to one of claims 13 or 14,
    characterized in
    that the central longitudinal axis of the insertion projection (30) is in the angular range of -10° to +10° with respect to the angle bisector of the first and second pair of bearing surfaces.
16. Bit holder according to any one of claims 1 to 15,
    characterized in
    that the surface normals of the first and/or second bearing surfaces (29.1, 29.4) run inclined to the tool advance direction (v).
17. Bit holder according to one of the claims 1 to 16,
    characterized in
    that a plane accommodating the angle bisector is arranged between the first and/or the second bearing surfaces (29.1, 29.4), and in that the longitudinal axis of the insertion projection (30) is arranged symmetrically with respect to this plane.
18. Bit holder according to one of claims 1 to 17,
    characterized in
    that at least 80% of the connection region of the insertion projection (30) to the support member (21) is arranged in the region of the pair of bearing surfaces formed by the first bearing surfaces (29.1).

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