QUICK-CHANGE HOLDER, QUICK-CHANGE CHISEL HOLDER SYSTEM, MILLING ROLLER FOR A ROAD MILLING MACHINE, AND ROAD MILLING MACHINE

Abstract

The invention relates to a quick-change holder for a quick-change chisel holder system for fastening a rotationally symmetrical milling chisel to a milling roller of a road milling machine, comprising a quick-change holder body, a chisel shank receptacle running along a longitudinal center axis in the quick-change holder body for receiving a chisel shank of the milling tool, a quick-change holder cone, which is formed by the quick-change holder body, lies in extension of the chisel shank receptacle, and for this purpose is designed to be clamped in an at least partially complementary holder receptacle of a basic holder of the quick-change chisel holder system, a tension means bearing arranged on the quick-change holder cone and designed to engage a tension means, with which the quick-change holder cone can be clamped on the basic holder in the direction of a cone axis of the quick-change holder cone, wherein the chisel shank receptacle and the tension means bearing are designed in such a way that the longitudinal center axis and the cone axis lie in a common plane and are angled relative to one another in this common plane. Furthermore, the invention relates to a quick-change chisel holder system and a milling roller.

Claims

1. A quick-change holder for a quick-change chisel holder system for fastening a milling tool, which is rotationally symmetrical, to a milling roller of a road milling machine, comprising: a quick-change holder body; a chisel shank receptacle running along a longitudinal center axis in the quick-change holder body for receiving a chisel shank of the milling chisel; a quick-change holder cone, which is formed by the quick-change holder body, lies at least partially in extension of the chisel shank receptacle and is designed to be clamped in an at least partially complementary holder receptacle of a basic holder of the quick-change chisel holder system; and a tension means bearing arranged on the quick-change holder cone and designed to engage a tension means with which the quick-change holder cone can be clamped on the basic holder in the direction of a cone axis of the quick-change holder cone, wherein the chisel shank receptacle and the tension means bearing are formed in such a way that the longitudinal center axis and the cone axis lie in a common plane and are angled relative to one another in this common plane.

2. The quick-change holder according to claim 1, wherein the longitudinal center axis and the cone axis are angled relative to one another by at least 3°, preferably by at least 5°, particularly preferably by at least 8° and ideally by at least 10°.

3. The quick-change holder according to claim 1, wherein it is designed in such a way that the longitudinal center axis and the cone axis meet at an intersection point, and in that the intersection point is located in the quick-change holder, in particular in the chisel shank receptacle.

4. The quick-change holder according to claim 1, wherein the longitudinal center axis passes through a lateral surface of the quick-change holder cone without overlapping and/or intersects an extrapolated continuation of the lateral surface of the quick-change holder cone outside the lateral surface at an intersection point.

5. The quick-change holder according to claim 1, wherein the quick-change holder body has a support shoulder, which at least partially runs around an entrance of the chisel shank receptacle and ends in a support plane, and in that the support plane is arranged perpendicularly to the longitudinal center axis and/or is intersected at an angle other than 90° by the cone axis.

6. The quick-change holder according to claim 1, wherein the quick-change holder body comprises a basic grip, which has a gripping arm designed to engage in a groove on the basic holder, and in that the longitudinal center axis is angled away from the basic grip, and in particular away from the gripping arm, with respect to the cone axis.

7. A quick-change chisel holder system for fastening a milling chisel to a milling roller of a road milling machine, in particular with a milling chisel, comprising a basic holder and a quick-change holder according to claim 1.

8. A milling roller for a road milling machine, wherein the milling roller is designed to rotate about a roller rotation axis and comprises a quick-change chisel holder system according to claim 7 fastened to the milling roller and a milling chisel with a chisel tip fastened thereto.

9. The milling roller according to claim 8, wherein an angle between the longitudinal center axis of the chisel shank receptacle and a straight line which starts perpendicularly from the roller rotation axis and runs through the chisel tip is at most 37°, preferably at most 35°, particularly preferably at most 32° and ideally at most 30°.

10. The milling roller according to claim 8, wherein an angle between the longitudinal center axis and an outer lateral surface of the milling roller is greater than an angle between the cone axis and the outer lateral surface of the milling roller.

11. A road milling machine, wherein it comprises a milling roller according to claim 8.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention is explained in more detail below with reference to the exemplary embodiments shown in the figures, which show schematically:

[0022] FIG. 1 is a side view of a road milling machine;

[0023] FIG. 2 is a perspective side view of a milling roller;

[0024] FIG. 3 is a side view of a quick-change chisel holder system with a milling chisel;

[0025] FIG. 4 is a sectional view through the quick-change chisel holder system according to FIG. 3;

[0026] FIG. 5 is a perspective side view of a quick-change holder;

[0027] FIG. 6 is a sectional view through a prior art quick-change holder with a milling chisel;

[0028] FIG. 7 is a sectional view through a prior art quick-change holder;

[0029] FIG. 8 is a perspective side view of a prior art change holder;

[0030] FIG. 9 is a sectional view of a first embodiment of a quick-change holder with a milling chisel;

[0031] FIG. 10 is a sectional view of a first embodiment of a quick-change holder;

[0032] FIG. 11 is a perspective side view of a first embodiment of a quick-change holder;

[0033] FIG. 12 is a sectional view of a second embodiment of a quick-change holder with a milling chisel;

[0034] FIG. 13 is a sectional view of a second embodiment of a quick-change holder;

[0035] FIG. 14 is a perspective side view of a second embodiment of a quick-change holder;

[0036] FIG. 15 is a prior art milling chisel at the moment of contact with the ground; and

[0037] FIG. 16 is a milling chisel at the moment of contact with the ground.

DETAILED DESCRIPTION

[0038] Components that are identical or have the same effect are designated with the same reference signs in the figures. Repeated components are not necessarily designated separately in each figure.

[0039] FIG. 1 shows a road milling machine 1, here in particular a cold miller of the center-rotor type. However, the invention is also applicable to road milling machines of the rear-rotor type. The road milling machine 1 comprises a machine frame 3 with a driver's cab 2. The machine frame 3 is supported by movement means 6, which in the exemplary embodiment shown are crawler tracks, but could also be wheels. The road milling machine 1 further comprises a milling roller 9 rotatably mounted in a milling roller box 7 about a roller rotation axis 10 running horizontally and transversely to a working direction a. The road milling machine 1 is itself mounted in a milling roller box 7. The road milling machine 1 is designed to be self-propelled and has a drive motor 4 which provides the necessary drive energy to operate the road milling machine 1. The drive engine 4 is typically an internal combustion engine, for example a diesel internal combustion engine. Alternatively, it can also be an electric motor. During operation, the road milling machine 1 moves in the working direction a over the ground 8 and mills it off. The loosened ground material is transported away from the milling roller box 7 and transferred to a conveyor device 5. The conveyor device 5 in turn transfers the milled material to a transport vehicle (not shown), for example a truck, which then transports it away. Some or all of the movement means 6 can be height-adjustable relative to the machine frame 6 by means of lifting devices, usually so-called lifting columns, in order to be able to vary the milling depth, for example.

[0040] FIG. 2 shows a perspective side view of the milling roller 9. This has a preferably substantially hollow-cylindrical roller tube 11, which can be connected to a drivetrain via a drive connection 12. A plurality of milling tools 39, which will be described in more detail below, are preferably arranged on the outer lateral surface of the milling roller 9. Furthermore, side cutters 13 can be arranged on the shown end face of the milling roller 9, which cut a lateral clearance for the milling roller 9 in the ground 8 during operation.

[0041] An embodiment of a milling tool 39 is shown in FIG. 3. The milling tool 39 preferably comprises a quick-change chisel holder system 14 with a basic holder 15 and a quick-change holder 16. A milling chisel 17 is in turn preferably mounted on or in the quick-change holder 16. A cross-section through the milling tool 39 according to FIG. 3 is shown in FIG. 4. FIG. 5 in turn shows a perspective view of the quick-change holder 16 alone. The basic holder 15 preferably has a fastening foot 18, by means of which the basic holder 15 can be fastenable to the outer lateral surface 38 of the roller tube 11. In addition, the basic holder 15 preferably comprises a holder receiving part 19, in which a holder receptacle 33 can be arranged. The holder receptacle 33 is preferably complementary to the quick-change holder cone 34 formed by the quick-change holder body 20 of the quick-change holder 16. In the assembled state, the quick-change holder 16 is preferably mounted with the quick-change holder cone 34 in the holder receptacle 33, more specifically in such a way that the lateral surface K of the quick-change holder cone 34 lies flat, and preferably at least partially running around the cone axis Z, against the inner surface of the holder receptacle 33. A tension device 25 with a tension means 36, for example a screw, is preferably provided for fastening the quick-change holder 16 to the basic holder 15. The tension means 36 preferably penetrates the basic holder and projects into the holder receptacle 33. The quick-change holder cone 34 is in turn preferably provided with a tension means bearing 37, for example a bore with an internal thread, which can be designed to receive the tension means 36. Overall, the tension device 25 and in particular the tension means bearing 37 of the quick-change holder 16 is preferably designed in such a way that the tensile force of the tension means 36 on the quick-change holder 16 acts along the cone axis Z. In particular, the tensile force of the tension means 36 presses the lateral surface K of the quick-change holder cone 34 against the inner surface of the holder receptacle 33 of the basic holder 15. In this way, forces acting on the milling chisel 17 and the quick-change holder 16 during operation of the milling roller 9 can be efficiently transmitted to the basic holder 15 and thus likewise to the roller tube 11 of the milling roller 9. This type of force transmission between the quick-change holder 16 and the basic holder 15 via the quick-change holder cone 34 is furthermore a defining feature of a quick-change chisel holder system 14 with quick-change holder cone 34 and distinguishes it from other quick-change chisel holder systems.

[0042] In addition, a chisel shank receptacle 30 is preferably arranged in the quick-change holder body 20. The chisel shank receptacle 30 is in particular a cylindrical cavity which is complementary to a chisel shank 31 of the milling chisel 17. It preferably has a longitudinal center axis L which corresponds in particular to the rotation axis of the cylindrical cavity, and in the assembled state of the milling chisel 17 likewise to the rotation axis of the milling chisel 17. The rotation axis of the milling chisel 17 preferably corresponds here both to the structural rotation axis of the rotationally symmetrical milling chisel 17, which is in particular a round-shank chisel, and to the rotation axis about which the milling chisel 17 can rotate during operation of the milling roller 9. The chisel shank receptacle 30 is preferably arranged along the cone axis Z and lies in particular on the cone axis Z. The chisel shank receptacle is preferably designed to receive the chisel shank 31 and a clamping sleeve 32, wherein the clamping sleeve 32 at least partially surrounds the chisel shank 31 and, by way of an interlocking fit, prevents an axial displacement and thus a pulling out or falling out of the milling tool 17 from the chisel shank receptacle 30. The chisel shank receptacle 30 is preferably at least partially surrounded by a support shoulder 35 on the side of the quick-change holder body 20 opposite the tension means bearing 37 or the quick-change holder cone 34. The support shoulder 35 preferably runs around the chisel shank receptacle 30 at least partially and in particular completely. In addition, the support shoulder 35 preferably forms a support surface lying in the support plane A. The support plane A is preferably arranged perpendicularly to the longitudinal center axis L. The support shoulder 35 preferably serves as an abutment for a wear plate 28 resting against it, which likewise preferably completely runs around the chisel shank receptacle 30 and against which the chisel head 27 of the milling chisel 17 bears by means of a rear abutment. In addition to the chisel shank 31 and the chisel head 27, the milling chisel 17 also comprises, in particular, a chisel tip 26, which is typically formed at least partially from hard metal. During operation of the road milling machine 1 or the milling rollers 9, the milling chisel 17 is preferably designed to be rotatable about the longitudinal center axis L, which leads to uniform wear of the milling chisel 17.

[0043] In addition, the quick-change holder body 20 preferably forms a basic grip 21. The basic grip 21 preferably comprises a web region 22 and a gripping arm 23. The web region 22 preferably comprises an upward curvature which is directed away from the gripping arm and from the basic holder or from the quick-change holder cone 34 and which serves to comminute lumps of milling material thrown around during milling operation and to absorb the wear occurring during this process instead of the basic holder 15. The gripping arm 23 in turn is preferably complementary to a groove 24 on the basic holder 15 and in particular engages in this groove 24. Forces directed away from the milling roller 9 can preferably be introduced by way of an interlocking fit from the quick-change holder 16 into the basic holder 15 via the gripping arm 23. This gripping arm 23 and the corresponding force transmission from the quick-change holder 16 to the basic holder 15 is also a typical feature of quick-change chisel holder systems 14 with quick-change holder cone 34.

[0044] The quick-change holder body 20 additionally preferably has an expulsion opening 29. The expulsion opening 29 is preferably arranged on the side of the quick-change holder body 20 opposite the basic grip 21 and, in particular, represents a cavity which leads from the outside of the quick-change holder body 20 to the chisel shank receptacle 30 and is connected thereto. The rear end of the chisel shank 31 is therefore preferably accessible from the outside through the expulsion opening 29. In order to ensure this accessibility in the fully assembled state of the quick-change chisel holder system 14, a corresponding expulsion opening 29 is preferably likewise provided in the basic holder 15 and extends from the outside of the basic holder 15 into the holder receptacle 33 and is connected thereto. In particular, the expulsion opening 29 in the basic holder 15 is designed in such a way that it is in communication with the expulsion opening 29 in the quick-change holder 16 when the quick-change holder 16 is mounted in the basic holder 15. Overall, the expulsion opening 29 therefore preferably provides open access to the rear end of the chisel shank 31 of the milling chisel 17, starting from the outside of the quick-change chisel holder system 14. A tool can therefore be inserted through the expulsion opening 29 and comes into contact with the chisel shank 31 so that this can be expelled, for example with targeted hammer blows.

[0045] The longitudinal center axis L of the chisel shank receptacle 30 is preferably angled relative to the cone axis Z by the angle W.sub.3. Preferably, the longitudinal center axis L and the cone axis Z lie in a common plane so that they meet at an intersection point X. The intersection point X is preferably located within the spatial extent of the quick-change holder 16. Particularly preferably, the intersection point X is located in the cylindrical cavity of the chisel shank receptacle 30. In particular, the longitudinal center axis L is angled away from the basic grip 21 relative to the cone axis Z by the angle W.sub.3. In particular, this refers to that portion of the longitudinal center axis L that is remote from the quick-change holder cone 34 and the tension means bearing 37, respectively. In other words, that half of the longitudinal center axis L which is angled away from the basic grip 21 is located behind the intersection point X of the cone axis Z and the longitudinal center axis L, coming from the quick-change holder cone 34 or the tension means bearing 37. By contrast, that half of the longitudinal center axis L which is directed towards the quick-change holder cone 34 or the tension means bearing 37 can be inclined towards the basic grip 21 due to the angulation between the longitudinal center axis L and the cone axis Z. The corresponding angulation preferably ensures that the chisel tip 26 of a milling chisel 17 mounted on the quick-change holder 16 is oriented away from the milling roller 9 or the outer lateral surface 38 of the roller tube 11. The longitudinal center axis L and also the milling chisel 17 are therefore preferably positioned more steeply in relation to the outer lateral surface 38 as a result of the angulation, which brings with it the advantages described for thin-layer milling.

[0046] As shown in particular in FIG. 4, the angle W.sub.4 between the cone axis Z and the outer lateral surface 38 of the roller tube 11 is preferably smaller than the angle W.sub.5 between the longitudinal center axis L and the outer lateral surface 38 of the roller tube 11. The difference between the angles W.sub.4, W.sub.5 corresponds in particular to the angulation between the longitudinal center axis L and the cone axis Z. In the shown exemplary embodiment of FIG. 4, the angle W.sub.3 is for example 8°, the angle W.sub.4 for example 44°, and the angle W.sub.5 for example 52°. As already mentioned, the support plane A of the support shoulder 35 is preferably arranged perpendicularly to the longitudinal center axis L. It follows from this that the support plane A is preferably not oriented perpendicularly to the cone axis Z. The angle W.sub.6 between the support plane A and the cone axis Z is therefore preferably an angle not equal to 90°. The angle W.sub.6 is, for example, 90° plus the angle W.sub.3 between the longitudinal center axis L and the cone axis Z, in the shown exemplary embodiment in FIG. 4 therefore 98°, for example.

[0047] As can also be seen in particular from FIG. 4, the longitudinal center axis L preferably does not intersect the lateral surface K of the quick-change holder cone 34. Although the longitudinal center axis L preferably passes through the lateral surface K of the truncated cone forming the quick-change holder cone 34, it preferably only penetrates its base surface and its top surface, but not the lateral surface K. However, if an extrapolated continuation K′ of the lateral surface K is considered, wherein the extrapolated continuation K′ lies outside the actual, real existing surface of the quick-change holder cone 34, it is preferred that the longitudinal center axis L intersects the extrapolated continuation K′ of the lateral surface K at an intersection point Y. The intersection point Y, in turn, preferably lies within the spatial extension of the basic holder 15. Additionally or alternatively, it can be provided that the intersection point Y is the point closest to the outer lateral surface 38 of the roller tube 11 of a section which is taken through the extrapolated continuation K′ of the lateral surface K and which is guided perpendicularly to the cone axis Z.

[0048] FIGS. 6-14 show a comparison of the prior art (FIGS. 6-8) with a first exemplary embodiment (FIGS. 9-11) and a second exemplary embodiment (FIGS. 12-14) of the invention, showing a cross-section through the quick-change holder 16 with a milling chisel 17 (FIGS. 6, 9 and 12), a cross-section through the quick-change holder 16 alone (FIGS. 7, 10 and 13), and a side view of the quick-change holder 16 (FIGS. 8, 11 and 14). FIGS. 6-8 show the prior art as also detailed in EP 2 425 951 A1. In the prior art, the longitudinal center axis L and the cone axis Z are parallel to each other and coaxial, i.e. the two axes are identical. In other words, the longitudinal center axis L and the cone axis Z have an infinite number of intersection points. By contrast, in the exemplary embodiments of the invention according to FIGS. 9-14, the longitudinal center axis L and the cone axis Z are not identical, but are angled relative to each other. However, they preferably lie in the same plane so that they have, in particular, exactly one intersection point X. In the exemplary embodiment according to FIGS. 9-11, the angle W.sub.3 between the longitudinal center axis L and the cone axis Z is, for example, 4°, while in the exemplary embodiment according to FIGS. 12-14 it is, for example, 8°.

[0049] As can be seen in particular from a comparison of FIGS. 6-8 concerning the prior art with the exemplary embodiments of the invention according to FIGS. 9-14, it is preferred that only the orientation of the chisel shank receptacle 30 and the support shoulder 35, which are each tilted by the angle W.sub.3, changes compared to the prior art. In particular, all shapes and surfaces of the quick-change holder 16 which come into contact with the basic holder 15 in the assembled state of the quick-change chisel holder system 14 are unchanged compared to the prior art, so that one and the same basic holder 15, as known from the prior art, can also be used in combination with a quick-change holder 16 according to the invention. For the use of the quick-change holder 16 according to the invention, it is therefore not necessary to manufacture a separate basic holder 15 or to mount it on the milling rollers 9. This leads to reduced manufacturing and usage costs of the system according to the invention. Furthermore, a quick-change holder 16 according to the invention can be retrofitted particularly easily to existing milling rollers 9 by simply attaching it to the basic holders 15 already present there in the usual manner Conversion of an existing milling roller 9 for upcoming thin-layer milling work is therefore also possible quickly and easily.

[0050] FIGS. 15 and 16 show a comparison between a milling tool 39 according to the prior art (FIG. 15) and a milling tool 39 according to the invention (FIG. 16) in working operation of the milling roller 9. In particular, FIGS. 15 and 16 show the moment during operation when the milling chisel 17 comes into contact with the ground 8 to be milled off. For this purpose, the milling roller 9 rotates about the roller rotation axis 10. The path curve along which the chisel tip 26 of the milling chisel 17 moves as a result of this rotation is referred to as the cutting circle S. The angle W.sub.1 lies between the longitudinal center axis L and a straight line R which starts perpendicularly from the roller rotation axis 10 and runs through the chisel tip 26. The straight line R thus starts radially from the roller rotation axis 10 and intersects the chisel tip 26. In the prior art case shown in FIG. 15, the angle W.sub.1 is greater than in the case of the milling tool 39 according to the invention, which is shown in FIG. 16. In the specific example shown, the angle W.sub.1 is 40° in FIGS. 15 and 32° in FIG. 16. In the invention, it is preferred that the angle W.sub.1 is 40° minus the angle W.sub.3 between the longitudinal center axis L and the cone axis Z. This results in the angle W.sub.2, which is between the longitudinal center axis L and a vertical V, being reduced compared to the prior art. In the example shown, the angle W.sub.2 is 24° on the left and 16° on the right. In the invention, it is preferred that the angle W.sub.2 is 24° minus the angle W.sub.3 between the longitudinal center axis L and the cone axis Z. As can be seen from FIG. 15, this ensures that the milling chisel 17 is oriented more steeply to the ground 8 at the moment of contact with the ground than in the prior art. This results in a more even load on the milling chisel and the quick-change holder, particularly in thin-layer milling, so that they wear more evenly and have a longer service life overall.