Abstract
The invention relates to a chisel (10) having a chisel head (11) and a chisel shaft (17), wherein near its end facing away from the chisel head the chisel shaft has a threaded portion having a thread (19), wherein the chisel head holds a chisel tip (20) made of a hard material, and wherein near the side facing the chisel shaft the chisel head is provided with a supporting surface (15). Especially when superhard hard materials are used for the chisel tip, a load-optimized chisel design is obtained by a domed supporting surface (15).
Claims
1. A chisel for a ground processing machine, the chisel comprising: a chisel head including a curved support face integrally formed on the chisel head, the curved support face including at least one of a spherical and an ellipsoid curve, the chisel head further including a tool receiving member, the tool receiving member including at least one of an outer polygonal member and a recess formed in the chisel head; a chisel shaft connected to the chisel head such that the support face faces the chisel shaft, the chisel shaft including a thread portion opposite the chisel head, the thread portion including a thread, the chisel shaft having a longitudinal center axis; and a chisel tip carried by the chisel head, the chisel tip including a hard material aligned along the longitudinal center axis.
2. The chisel of claim 1, wherein the tool receiving member is the outer polygonal member.
3. The chisel of claim 2, wherein the outer polygonal member is an outer hexagonal member.
4. The chisel of claim 1, wherein the tool receiving member is the at least one recess formed in the chisel head.
5. The chisel of claim 1, the chisel head further comprising a discharge face arranged between the chisel tip and the tool receiving member.
6. The chisel of claim 5, the chisel head further comprising a chisel tip receiver opposite the chisel shaft.
7. The chisel of claim 1, the chisel tip including an operating portion which includes at least one of diamond, polycrystalline diamond, natural diamond, synthetic diamond, vapor-deposition diamond, silicon-bonded diamond, cobalt-bonded diamond, thermally stable diamond, cubic boron nitride, a diamond-infiltrated material, a diamond-tipped matrix, a diamond-impregnated carbide, and a material having a comparable hardness to diamond.
8. The chisel of claim 1, the chisel shaft including a reduced diameter expansion portion between the thread portion and the chisel head.
9. The chisel of claim 8, wherein the expansion portion extends at least 20 mm and a maximum of 50 mm along a longitudinal center axis of the chisel shaft.
10. The chisel of claim 1, in combination with: a nut retained on the thread portion; wherein the chisel further includes a transition region located between the chisel head and the chisel shaft, the transition region including a transition diameter; the chisel shaft including a constant shaft cross-section from the chisel head toward the thread portion; and the thread portion including a thread portion diameter substantially similar to the transition diameter.
11. The combination of claim 10, the nut including a nut seal portion.
12. The combination of claim 10, the nut including a securing portion having blocking faces on a periphery of the nut.
13. The combination of claim 12, the blocking faces including curved face portions.
14. The combination of claim 13, wherein each of the blocking faces merge into an adjacent blocking face in a curved transition.
15. The chisel of claim 1, the chisel head including at least one of a peripheral projection and a peripheral recess arranged on the support face.
16. The chisel of claim 15, wherein the at least one of a peripheral projection and a peripheral recess extends concentrically relative to the chisel shaft.
17. The chisel of claim 1, in combination with: a holder configured to receive the chisel shaft, the holder including a chisel head receiver diameter; and wherein the chisel head includes a maximum chisel head diameter greater than the chisel head receiver diameter.
18. A chisel for a around processing machine, the chisel comprising: a chisel head including a curved support face integrally formed on the chisel head; a chisel shaft connected to the chisel head such that the support face faces the chisel shaft, the chisel shaft including a thread portion opposite the chisel head, the thread portion including a thread, the chisel shaft having a longitudinal center axis; and a chisel tip carried by the chisel head, the chisel tip including a hard material aligned along the longitudinal center axis; wherein the chisel shaft includes a reduced diameter expansion portion between the thread portion and the chisel head; wherein the expansion portion extends at least 20 mm and a maximum of 50 mm along a longitudinal center axis of the chisel shaft; and wherein the expansion portion includes a uniform circular cross-section.
19. The chisel of claim 18, the curved support face including at least one of a spherical and an ellipsoid curve.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The invention is explained in greater detail below with reference to embodiments illustrated in the drawings, in which:
(2) FIG. 1 is a side view and a partially sectioned view of a chisel,
(3) FIG. 2 is a perspective view of the chisel according to FIG. 1,
(4) FIG. 3 is a plan view of the chisel according to FIGS. 1 and 2,
(5) FIGS. 4 and 5 are perspective views of a nut,
(6) FIG. 6 is a plan view of the nut according to FIGS. 4 and 5,
(7) FIG. 7 is a line of section indicated VII-VII in FIG. 6,
(8) FIGS. 8 and 9 are perspective views of a chisel holder,
(9) FIG. 10 is a side view of the chisel holder according to FIGS. 8 and 9,
(10) FIG. 11 shows a line of section indicated XI-XI in FIG. 10,
(11) FIG. 12 is an exploded view of a chisel holder changing system,
(12) FIG. 13 is a side view and sectioned view of the chisel holder changing system according to FIG. 12,
(13) FIG. 14 is a side view of a chisel,
(14) FIG. 15 is a perspective view of a milling roller of a road milling machine,
(15) FIG. 16 is a side view and partially sectioned view of a chisel,
(16) FIG. 17 shows a detail indicated in FIG. 16,
(17) FIG. 18 is a sectioned view of a chisel holder,
(18) FIG. 19 is a section detail taken from FIG. 18,
(19) FIGS. 20 and 21 show another alternative construction of a chisel,
(20) FIG. 22 is a section through a chisel holder changing system,
(21) FIG. 23 is a side view and partially sectioned view of a chisel holder according to FIG. 22,
(22) FIGS. 24 to 27 are side views of different versions of chisel holder changing systems.
DETAILED DESCRIPTION
(23) FIG. 1 shows a chisel 10 having a chisel head 11 on which a chisel shaft 17 is integrally formed. The chisel head 11 has at the end thereof facing away from the chisel shaft 17 a receiving member 12 which is constructed in this instance in the form of a blind-hole-like bore. A chisel tip 20 is inserted into this receiving member 12. The chisel tip 20 has a connection portion 23 which may comprise hard metal. The connection portion 23 has at the end thereof facing away from the chisel shaft 17 a receiving member in which a carrier member 22 is inserted. The carrier member 22 comprises a hard material, for example, hard metal. It is provided at the free end thereof with a hard material coating 21. The hard material coating 21 is in this instance formed by a superhard material. In this instance, it is, for example, possible to use a material which has a similar hardness to diamond. In particular, the hard material coating 21 may comprise polycrystalline diamond. The carrier member 22 is connected to the connection portion 23 by means of a suitable connection. For example, a solder connection may be provided. The connection portion 23 may be connected to the chisel head 11 in the chisel receiving member 12 by means of a suitable connection. For example, a solder connection may be selected. The construction of the chisel tip 20, comprising the connection portion 23 and the carrier member 22 which is connected thereto with a hard material coating 21 can be produced in a simple manner. The spatially smaller carrier member 22 may be coated in a suitable coating installation with the hard material coating. The connection portion 23 of wear-resistant material is structurally larger than the carrier member 22 and therefore has a high capacity for wear.
(24) It is also conceivable for the entire chisel tip 20 to be constructed integrally. The chisel tip could then comprise, for example, hard metal. It is further conceivable for the chisel head 11 itself to be provided with a hard material coating which forms the chisel tip and which is preferably of superhard material. The component complexity can thereby be considerably reduced.
(25) Alternatively, it is also conceivable for the hard material coating 21 to be applied directly to the connection portion 23 with the carrier member 22 being omitted.
(26) Alternatively, the connection portion 23 could also be constructed integrally with the carrier member 22, which would lead to a similar chisel tip, as in the preceding example, only the interface would be different.
(27) The portion of the chisel head 11 forming the receiving member 12 has a discharge face 13 which expands from the chisel tip 20 in the direction toward the shaft 17. That discharge face 13 may in particular be constructed in a concave manner, as clearly shown in FIG. 1. Adjacent to the discharge face 13, the chisel head 11 forms a tool receiving member 14. This is constructed in this instance as an external hexagonal member, as shown in FIG. 3. The external hexagonal member has a conventional wrench width for fitting a commercially available tool. Adjacent to the tool receiving member 14, the chisel head 11 forms a support face 15. The support face 15 is curved in a spherical manner. In the present embodiment, a simple-to-produce, convex ball contour is used as a spherical curvature. The chisel shaft 17 is formed centrally on the support face 15 so that the support face 15 extends in a uniform manner about the longitudinal center axis M of the chisel shaft 17. The coupling of the chisel shaft 17 to the chisel head 15 is carried out in a tension-optimized manner via a transition 16 which is formed by a rounded portion. The chisel shaft 17 has a cylindrical region, which forms an expansion portion 17.1. In the region of the free end of the chisel shaft 17, a thread 19 is cut on the chisel shaft 17. A recess 18 is provided between the thread 19 and the chisel shaft 17.
(28) Via the thread 19, the chisel can be screwed to the nut 30 shown in FIGS. 4 to 7. As these drawings show, the nut 30 has a sealing portion 31 in the form of a cylindrical attachment. In the outer periphery of the sealing portion 31 there is formed a groove which can clearly be seen in FIG. 7. This groove serves to receive a seal 32 which is constructed in this instance as an O-ring. A securing portion 33 adjoins the sealing portion 31. The securing portion 33 has blocking faces 34 which are constructed in a concave-curved manner. The blocking faces 34 merge into each other via convex transition portions 35. As shown in FIG. 6, the nut 30 has five blocking faces 34 which are arranged so as to be distributed in a uniform manner with the same angular spacing over the outer periphery of the nut 30. The thread 36 extends through the nut 30. In a state adjacent to the thread 36, the nut 30 has in the region of the sealing portion 31 a radial impact face 37.
(29) FIGS. 8 to 11 show a chisel holder 40 for receiving the chisel 10 shown in FIGS. 1 to 3. The chisel holder 40 has a base portion 41 which has a cylindrical outer contour. At the upper end thereof, the chisel holder 40 has a cylindrical attachment 42. The cylindrical attachment 42 may include, in a non-limiting example, at least one surface contour 43 such as at least one of a peripheral projection and a peripheral recess arranged on the base portion 41. In this instance, the diameter of the cylindrical attachment 42 is selected to be slightly larger than the diameter of the base portion 41. The cylindrical attachment 42 forms a counter-face 44 which is constructed so as to be curved in a spherical manner and concave. The chisel holder 40 merges in a manner adjacent to the counter-face 44 into a chisel receiving member 45 which is constructed as a bore in this instance. In a state facing away from the counter-face 44, the chisel receiving member 45 opens in a sealing portion 46 which is constructed in a bore-like manner as an inner cylinder. A seal receiving member is introduced in the wall region delimiting the sealing portion 46. The seal receiving member may, as illustrated in this instance, be constructed as a peripheral groove 46.1.
(30) The chisel holder 40 has at the end thereof facing away from the cylindrical attachment 42 a holder receiving member 47. FIGS. 8 and 11 allow the structure of the holder receiving member 47 to be seen more clearly. As can be seen from these illustrations, the holder receiving member 47 is constructed as an internal receiving member in the chisel holder 40. It is delimited by five retention faces 47.1 which are curved in a convex manner. The retention faces 47.1 merge into each other via concave transition portions 47.2. The curvature of the retention faces 47.1 and the transition portions 47.2 is constructed to be adapted to the curvature of the blocking faces 34 and the transition portions 35 of the nut 30. Accordingly, the nut 30 can be guided from the rear end of the chisel holder 40 with the sealing portion 31 through the region of the holder receiving member 47 and pushed into the region of the sealing portion 46. The insertion movement of the nut 30 is blocked by means of the impact face 37 which comes to rest on a stop 46.2 of the sealing portion 46. In this assembly state, the seal 32 engages in the groove 46.1 of the sealing portion 46 so that the transition region between the outer contour of the nut 30 and the inner contour of the sealing portion 46 is sealed. The blocking faces 34 are arranged opposite the retention faces 47.1. The transition portions 35 and 47.2 are also opposite each other. In this manner, a non-rotatable arrangement of the nut 30 in the holder receiving member 47 is achieved. Since the seal 32 is retained in a manner clamped between the nut 30 and the chisel holder 40, the nut 30 is retained in a non-releasable manner.
(31) FIG. 12 is an exploded view of a chisel holder changing system in which the chisel holder 40 is secured in a suitable manner to a lower portion 50, for example, welded. The lower portion 50 has for this purpose a securing portion 51 which in accordance with the cylindrical contour of the base portion 41 of the chisel holder 40 has a concave recess. The securing portion 51 is formed by a carrier portion 52 of the lower portion 50. The carrier portion 52 is formed integrally on a base portion 54 by means of a transition portion 53. The base portion 54 has a lower support face 55. With the support face 55, the chisel holder 40 can be placed on the outer face of a cutting roller pipe and can be secured thereto in a suitable manner, for example, welded.
(32) FIG. 13 shows the above-described assembly position of the nut 30 in the holder receiving member 47. The chisel 10 can be inserted with the chisel shaft 17 thereof past the counter-face 44 into the chisel receiving member 45. In this instance, the expanding counter-face 44 facilitates the introduction movement of the chisel 10. When the thread 19 of the chisel 10 strikes the nut 30, the chisel 10 can be screwed with the thread 19 thereof into the thread 36 of the nut 30. This screwing-in movement can first be carried out by hand until the support face 15 comes to rest on the counter-face 44. Subsequently, a suitable tool can be placed on the tool receiving member 14. The chisel 10 can then be rotated with the tool and, in this instance, the threaded connection between the thread 19 and the thread 36 can then be tensioned. In order to ensure reliable fixing of the chisel 10 during the processing operations which are intended to be carried out, a high tightening torque has to be selected. In this instance, the support faces 15 and the counter-face 44 press each other. As a result of this pressing action, a seal between the chisel head 11 and the counter-face 44 is brought about in such a manner that no contamination can be introduced. Via the high torque, the expansion portion 17.1 of the chisel shaft 17 is resiliently deformed. This resilient deformation portion, in the event of loads acting on the chisel tip 20 in an impact-like manner, prevents the threaded connection between the nut 30 and the chisel shaft 17 from being able to be released. The selected geometry of the concave blocking faces 34 and the convex retention faces 47.1 enable increased force transmission regions with respect to conventional, elongate surface portions, as are conventional with nuts. Of course, the retention faces 47.1 may also be curved in a concave manner and the blocking faces 34 may accordingly be curved in a convex manner.
(33) The convex/concave pairings selected prevent for the selected high tightening torques a plastic deformation of the blocking faces 34 or the retention faces 47.1 from being able to be produced. Consequently, in particular the holder receiving member 47 remains in the desired form and during the chisel change a new nut 30 can be inserted in a reproducible manner.
(34) During the tool engagement, the chisel tip 20 strikes the substrate which is intended to be cut and cuts into it. In this instance, the material cut slides off the chisel tip 20. As a result of the large forces present in the region of the chisel tip 20, a great abrasive attack is brought about in this instance. This attack is taken into account by the structure of the chisel 10 with the connection portion 23, which comprises hard material, for example, hard metal. After the material removed has passed the connection portion 23, it reaches the region of the discharge face 13. It has then already lost a large proportion of its abrasive nature and can be safely guided further by the discharge face 13. In this instance, it is guided radially outward from the discharge face 13 and discharged from the tool receiving member 14 and the chisel holder 40 so that where possible it is not subjected to wear or is subjected only to slight wear.
(35) Since the chisel 10 cannot rotate, it is first worn away at one side. This is permissible up to a specific wear limit. Then, the chisel 10 is released by means of the appropriate tool which engages on the tool receiving member 14. Subsequently, the nut 30 can be pulled from the holder receiving member 47 and inserted therein again in a rotated state. As a result of this rotation, the thread intake in the thread 36 is also arranged in a rotated position with respect to the chisel holder 40. When the same chisel 10 is again screwed to the nut 30, wherein the same tightening torque is again preferably intended to be selected, then the chisel head 11, and consequently the chisel tip 20 opposite the chisel holder 40, moves into abutment in a correspondingly rotated position. The processing side of the chisel 10 is then formed by a non-worn chisel tip location.
(36) In the present embodiment, 5 blocking faces 34 which are arranged in a state distributed in a uniform manner with respect to each other are provided on the nut 30. Accordingly, the chisel 10 may also be secured at five mutually rotated locations to the chisel holder 40. It has been found that such an arrangement is particularly advantageous when the chisel 10 is used for the purpose of fine-milling of road surfaces. When rotated by the extent of a blocking face 34, the chisel 10 can then be worn in a manner optimized in terms of wear, wherein at the same time a high surface quality of the milled road surface is retained. When six blocking faces are used, optimized use of the chisel tip 20 in terms of wear is not achieved, as is possible with 5 blocking faces. When four blocking faces are used, there is an excessively high variance in the surface quality when the chisel tip 20 is intended to be used completely. Furthermore, when 5 blocking faces are used, that is to say, an uneven number of blocking faces 34, it is also possible to operate in such a manner that the chisel 10 is always rotated to the extent of two blocking faces 34. In this manner, a continuous uniform wear of the chisel for the purpose of high surface qualities of the milled surface can be achieved.
(37) FIG. 14 shows another construction variant of a chisel 10. This chisel is constructed in an identical manner to the chisel 10 according to FIGS. 1 to 3 with the exception of the structure of the chisel shaft 17. Reference may therefore be made to the corresponding statements above. Furthermore, the nut 30 according to FIGS. 4 to 7 can be screwed to the thread 19 of the chisel 10, and it can accordingly be fitted in the chisel holder 40 according to FIGS. 8 to 11.
(38) The chisel shaft 17 of the chisel 10 according to FIG. 14 has an expansion portion 17.1 which is constructed in the form of a cross-section reduction in order to achieve improved expansion behavior.
(39) FIG. 15 shows a milling roller 60 which has a milling roller pipe 61. A large number of chisel holders 40 according to FIGS. 8 to 11 are directly secured, for example, welded, to the surface 62 of the milling roller pipe 60. The chisel holders carry the chisels 10, for example, according to FIGS. 1 to 3. As described above, the chisel holder changing systems may accordingly also be fitted in accordance, for example, with FIGS. 12 and 13 with the milling roller pipe 61. To this end, the lower portions 50 are placed with the support faces 55 thereof on the surface 62 and welded to the milling roller pipe 60.
(40) FIGS. 16 to 19 show an alternative construction of the invention to FIG. 1 to 13 or 14, wherein the chisel 10 and the chisel holder 40 are slightly modified. In order to prevent repetition, reference may therefore be made to the above statements and only the differences will be discussed below. As can be seen in FIGS. 16 and 17, in the region of the support face 15 a peripheral recess 15.1 is formed in a groove-like manner. It extends concentrically about the chisel axis M. FIGS. 18 and 19 show the chisel holder 40 which in the region of the counter-face 44 has a peripheral projection 44.1. It is constructed in a bead-like manner and also extends concentrically about the longitudinal center axis of the chisel holder 40. The positioning of the projection 44.1 is selected in such a manner that, in the assembled state of the chisel 40, it engages in the recess 15.1. In this manner, a labyrinth-like seal is formed in the region of the support face 15/counter-face 44, and impedes the introduction of dirt into the region of the chisel receiving member 45. Furthermore, the support face 15 is interrupted with the recess 15.1 so that reliable surface contact with respect to the counter-face 44 is always ensured, even with production-related deviations from the ideal shape.
(41) In place of the projection 44.1, it is also possible to use a ring, for example, a sealing ring, in particular a commercially available O-ring or a copper ring or a similar metal ring. This may be laid in a peripheral groove of the chisel holder 40 in the region of the counter-face 44. With the region thereof which protrudes over the counter-face 44, this sealing ring then engages in the recess 15.1.
(42) FIGS. 20 and 21 show another embodiment of a chisel 10. This chisel is constructed in accordance with the chisel 10 according to FIGS. 1 to 3, for which reason, in order to prevent repetition, only the differences are intended to be discussed below. The chisel head 11 is provided with a plurality of tool receiving members 14 on an outer periphery. These may be formed as recesses in the outer contour of the chisel head 11. The recesses are open in a radially outward direction and in an axially upward direction. Consequently, a tool can be readily fitted from the chisel tip 20. Furthermore, the tool receiving members 14 cannot become clogged with waste material or are easy to clean where applicable.
(43) FIGS. 22 to 27 show various embodiments of chisel holder changing systems, in which the above-described chisels 10 can be used together with the nut 30 according to FIGS. 4 to 7. In these drawings, for the identification of identical or equivalent components, the same reference numerals as above are used. Reference may therefore be made in full to the statements above.
(44) FIG. 22 shows a tool holder changing system having a tool holder 40, which carries at a base portion 41 an integrally formed plug type attachment 48. A cylindrical attachment 42 is further formed on the base portion 41. In the region of the cylindrical attachment 42, a counter-face 44 corresponding to the counter-face 44 is again constructed in accordance with the chisel holder 40 according to FIGS. 8 to 11. In the base portion 41 and the cylindrical attachment 42, there is formed a chisel receiving member 45 which terminates in a sealing portion 46. The sealing portion 46 is again adjoined by the holder receiving member 47, in which the nut 30 according to FIGS. 4 to 7 is inserted. In this instance, the nut 30 again has a securing portion 33 with blocking faces 34. The blocking faces 34 cooperate with retention faces 47.1 of the chisel holder 40 in order to secure the nut 30 in a rotationally secure manner. The nut 30 is again sealed with the sealing portion 31 thereof and the seal 32 on the sealing portion 46 of the chisel holder 40.
(45) As can further be seen in FIG. 22, the chisel 10 with the thread 19 is screwed into the thread 36 of the nut 30 until the impact face 37 strikes the chisel holder 40.
(46) The chisel holder 40 is inserted with the plug type attachment 48 thereof into a plug type receiving member of a lower portion 50. The chisel holder 40 is supported with respect to the lower portion 50 and is retained in the lower portion 50 with a pressure screw 56 which acts on the plug type attachment 48.
(47) FIG. 23 shows the combination of the chisel holder 40 with the chisel 10, as described above with reference to FIG. 22.
(48) FIG. 24 shows another chisel holder changing system. Accordingly, there is again used a chisel holder 40 which receives the chisel 10 and the nut 30 in the manner described above. The chisel holder 40 is retained in a lower portion 50 with a plug type attachment which cannot be seen in FIG. 24.
(49) FIG. 25 shows a construction variant of a chisel holder changing system having a chisel holder 40 and a lower portion 50.
(50) FIG. 26 shows another construction variant of a chisel holder changing system having a chisel holder 40 and a lower portion 50 which receives the chisel holder 40.
(51) FIG. 27 discloses a tool system having a chisel holder 40, in which the chisel 10 is inserted. The chisel holder 40 can be placed directly on the surface 62 of a milling roller pipe 60 and secured thereto, for example, welded.
