Rotary cutting tool

Abstract

A rotary cutting tool (10) has a tool shank (12) and at least one guide pad (21, 22) fastened on an outer circumference (26) of the tool shank (12) and having a radially outer fluid groove (24). The guide pad (21, 22) has an inlet channel (38) via which the fluid groove (24) is fluidly connected to an internal fluid line (32) in the tool shank (12).

Description

Technical Field

[0001] The invention relates to a rotary cutting tool having a tool shank and at least one guide pad which is fastened to the outer circumference of the tool shank and has a radial outer fluid groove. Background Art

[0002] Such rotary cutting tools having guide pads are known.

[0003] Guide pads are used to support and guide the rotating cutting tool on the workpiece during the cutting operation to ensure a defined cut. To keep friction to a minimum, the guide pads are supplied with lubricant, which is provided via holes and grooves in the tool shank and via a separate cap on the tool shank.

[0004] This design of a rotary cutting tool is very complex to manufacture and also has the disadvantage that the diameter size of the rotary cutting tool is severely limited. Summary of the invention

[0005] The problem addressed by the present invention is to provide a rotary cutting tool which can be manufactured without much effort and which provides an efficient lubricant supply.

[0006] This problem is solved by a rotary cutting tool having a tool shank and at least one guide pad fastened on the outer circumference of the tool shank and having a radially outer fluid groove. The guide pad has an inlet channel via which the fluid groove is fluidically connected to an internal fluid line in the tool shank.

[0007] It has been creatively found that in this way, the rotary cutting tool can be designed with low complexity and can be manufactured at low cost. Because the fluid supply ends in the fluid groove, the fluid is directly provided at the required position, that is, at the guide pad. This makes the fluid supply particularly effective and efficient. In addition, this design has the advantage that the rotary cutting tool can be compact and can have a particularly small diameter. The fluid is made available by the groove in the wide section outside the pad. Because the guide pad has an inlet channel, a defined connection to the internal fluid pipeline is ensured so that the fluid can reliably flow from the internal fluid pipeline to the fluid groove during operation.

[0008] According to one embodiment, the inlet channel is arranged radially on the inner side of the guide pad, so that the connection to the internal fluid line is particularly short.

[0009] In particular, the inlet channel is directly fluidly connected to the internal fluid line.

[0010] The guide pad may have an internal fluid channel extending in the longitudinal direction of the guide pad, via which the inlet channel is fluidically connected to the fluid groove. Since the fluid supply passes through the internal fluid channel and thus through the guide pad, the fluid can be provided in the fluid groove particularly efficiently and effectively.

[0011] The fluid groove extends parallel to the guide pad.

[0012] Furthermore, it can be provided that the guide pad has at least one through hole, via which the fluid channel is fluidically connected to the fluid groove. The position and geometry of the through hole define the manner in which the fluid flows from the fluid channel into the fluid groove. In particular, the amount of fluid that flows into the fluid groove through the through hole during operation can be determined in this way.

[0013] In one embodiment, at least one through hole has a circular cross section and thus opens into the fluid recess in a locally restricted area.

[0014] In an alternative embodiment, at least one through hole has a polygonal cross-section.

[0015] In a further embodiment, at least one through hole has an elongated cross section and extends over at least 50%, in particular over at least 90%, of the longitudinal extent of the fluid groove. In other words, the through hole here is designed as a slot. This design has the advantage that the through hole opens into the fluid groove over a large part of the longitudinal extent of the fluid groove, so that during operation, the fluid flows into the fluid groove over a particularly large area.

[0016] Additionally or alternatively, when viewed in the radial direction, the inlet channel may not overlap with the at least one through hole, or the inlet channel may not be arranged directly radially opposite to the at least one through hole. Because the inlet channel is axially offset or spaced apart from the through hole, the fluid cannot flow out of the inlet channel into the through hole in the radial direction during operation, but is diverted in the fluid channel. This ensures that the fluid is evenly distributed in the fluid channel, particularly at low pressure.

[0017] The fluid channel may have a first end section and a second end section, the second end section being located opposite the first end section in the longitudinal direction. The inlet channel opens into the fluid channel in the first end section, and at least one through hole opens into the fluid channel in the second end section. This ensures that the fluid flows uniformly through substantially the entire fluid channel during operation, in particular at low pressure.

[0018] According to one embodiment, the fluid groove extends over at least 50%, in particular over at least 75%, of the longitudinal extent of the guide pad, whereby sufficient fluid is provided on the guide pad during operation to reliably and completely wet the guide pad with fluid on its guide surface, in particular over the entire longitudinal extent of the guide pad.

[0019] According to a further embodiment, the tool shank does not have fluid grooves on the outer circumference, so the tool shank can be designed with less complexity.

[0020] Furthermore, it can be provided that the internal fluid line has a central main channel and a transverse channel, wherein the main channel is fluidically connected to the fluid groove via the transverse channel. In this way, the tool shank can be produced particularly easily.

[0021] Additionally or alternatively, at least one guide pad can be fastened in a receiving groove on the outer circumference of the tool shank. This ensures a defined and secure fastening of the guide pad.

[0022] In one embodiment, at least two guide pads distributed around the circumference are provided in order to particularly effectively support and guide the rotating cutting tool during the cutting operation.

[0023] The guide pads may be evenly distributed around the circumference.

[0024] Furthermore, at least one cutting insert can be fastened in the region of an axial end of the tool shank in order to machine a workpiece in a cutting operation.

[0025] In a further embodiment, at least one guide pad protrudes radially relative to the outer circumference in order to provide a defined guidance and to keep the friction between the rotating cutting tool and the workpiece low during the cutting operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other advantages and features will be apparent from the following description and the accompanying drawings. The accompanying drawings show:

[0027] - FIG. 1 shows a perspective view of a rotary cutting tool according to the invention having a first guide pad and a second guide pad,

[0028] - FIG. 2 shows the rotary cutting tool of FIG. 1 in a top view,

[0029] - FIG. 3 shows the rotary cutting tool in a sectional view along the plane AA in FIG. 2 ,

[0030] - FIG. 4 shows a side view of the first guide pad of FIG. 1 according to a first embodiment,

[0031] - FIG. 5 shows the first guide pad in a sectional view along the plane BB in FIG. 4 ,

[0032] - FIG. 6 shows the first guide pad in a sectional view along the plane CC in FIG. 4 ,

[0033] - FIG. 7 shows a side view of the first guide pad of FIG. 1 according to a second embodiment,

[0034] - FIG. 8 shows the first guide pad in a sectional view along the plane DD in FIG. 7 ,

[0035] - FIG. 9 shows the first guide pad in a sectional view along the plane EE in FIG. 7 ,

[0036] - FIG. 10 shows a side view of the second guide pad of FIG. 1 according to the first embodiment,

[0037] - FIG. 11 shows the second guide pad in a sectional view along the plane FF in FIG. 10 ,

[0038] - FIG. 12 shows the second guide pad in a sectional view along the plane GG in FIG. 10 ,

[0039] - FIG. 13 shows a side view of the second guide pad of FIG. 1 according to a second embodiment,

[0040] - FIG. 14 shows the second guide pad in a cross-sectional view along the plane HH in FIG. 13 , and

[0041] - FIG. 15 shows the second guide pad in a sectional view along the plane JJ in FIG. 13 . DETAILED DESCRIPTION

[0042] FIG. 1 shows a rotary cutting tool 10 having a tool shank 12 and an axis of rotation X. In the embodiment of FIG.

[0043] The rotating cutting tool 10 is a reamer here.

[0044] In principle, the rotary cutting tool 10 can be any rotary cutting tool, such as a drill or a countersink.

[0045] The rotary cutting tool 10 also has two axially spaced apart cutting blades 14 , one of which is secured to an axial end 16 of the tool shank 12 .

[0046] In alternative embodiments, the rotary cutting tool 10 may have any number of cutting blades 14 , with each cutting blade secured at any location on the tool handle 12 .

[0047] In the exemplary embodiment shown, the cutting blade 14 is an indexable blade.

[0048] The rotary cutting tool 10 also has two first guide pads 21 and three second guide pads 22 , each of which has a fluid groove 24 .

[0049] The guide pads 21 , 22 consist of carbide.

[0050] In an alternative embodiment, the guide pads 21 , 22 consist of ceramic or a diamond-like material such as polycrystalline diamond (PCD).

[0051] According to one embodiment, the guide pads 21 , 22 are manufactured using an additive manufacturing process, for example by 3D printing, so that even complex geometries can be produced without difficulty.

[0052] The first guide pad 21 and the second guide pad 22 are each arranged at an angle α of 120° to one another (see FIG. 2 ) on the outer circumference 26 of the tool shaft 12 .

[0053] Thus, three second guide pads 22 are evenly distributed around the circumference 26 .

[0054] Furthermore, the first guide pad 21 is arranged axially spaced apart from the second guide pad 22 .

[0055] In the present exemplary embodiment, the first guide pad 21 is arranged at the axial end 16 .

[0056] In principle, the rotary cutting tool 10 can have any number of guide pads 21 , 22 , each of which is fastened at any position on the tool shaft 12 , except for at least one first guide pad 21 or one second guide pad 22 .

[0057] In particular, in one embodiment, the rotary cutting tool 10 may not have the first guide pad 21 or may not have the second guide pad 22 .

[0058] The guide pads 21 , 22 are each fastened in a correspondingly designed receiving groove 28 on the outer circumference 26 .

[0059] For example, the guide pads 21 , 22 are connected to the tool shaft 12 by material bonding, in particular by gluing or welding.

[0060] Additionally or alternatively, the guide pads 21 , 22 may be connected to the tool shaft 12 in a form-fitting and / or press-fitting manner, for example via a screw connection.

[0061] Furthermore, the guide pads 21 , 22 are fastened on the tool shank 12 in such a way that the radially outer guide surface 30 of each of the guide pads 21 , 22 protrudes radially relative to the outer periphery 26 .

[0062] In this case, the fluid groove 24 is arranged in or opens into the guide surface 30 of the corresponding guide pad 21 , 22 , respectively.

[0063] To supply fluid to the fluid groove 24 during operation, the tool handle 12 has an internal fluid line 32 (see FIG. 3 ) that is fluidly connected to the fluid groove 24 .

[0064] The fluid is, for example, a lubricant, in particular a cooling lubricant.

[0065] In the present exemplary embodiment, the internal fluid line 32 has a central main channel 34 and five transverse channels 36 which are fluidically connected to the main channel 34 and extend radially to the outer periphery 26 and are respectively associated with one of the guide pads 21 , 22 .

[0066] The transverse channels 36 each end radially opposite an inlet channel 38 which is arranged in the underside 40 of the respective guide pad 21 , 22 .

[0067] The underside 40 is arranged opposite the guide surface 30 and is therefore arranged radially inwardly.

[0068] During operation, fluid flows from the central main channel 34 (connected to a fluid source), via the transverse channels 36 , through the inlet channels 38 , into the guide pads 21 , 22 , and from there out of the guide pads 21 , 22 via the fluid grooves 24 and to the guide surface 30 .

[0069] In this case, the tool shaft 12 itself has no external fluid grooves, in particular not on the outer circumference 26 .

[0070] This means that during operation, fluid for lubricating the guide pads 21 , 22 is provided substantially via the fluid grooves 24 in the guide pads 21 , 22 .

[0071] In this case, the internal fluid line 32 is fluidly connected directly to the inlet passage 38 , such that during operation, fluid flows directly out of the internal fluid line 32 into the inlet passage 38 .

[0072] In an alternative embodiment, the tool shank 12 may additionally have external fluid grooves on the outer circumference 26 for lubricating the guide pads 21 , 22 .

[0073] In all embodiments, the tool shaft 12 may have a fluid outlet or nozzle through which fluid is provided to components or sections of the rotary cutting tool 10 other than the guide pads 21 , 22 , in particular to the cutting blade 14 , during operation.

[0074] The proportion of fluid reaching the guide pads 21 , 22 , in particular the guide surface 30 , via these fluid outlets or nozzles is negligible compared to the proportion of fluid provided directly to the guide surface 30 via the fluid groove 24 .

[0075] 4 to 6 , the structure of the first guide pad 21 according to the first embodiment will now be described.

[0076] The fluid groove 24 of the first guide pad 21 has a longitudinal extent I in the longitudinal direction Q which is approximately 80% of the longitudinal extent L of the first guide pad 21 .

[0077] The longitudinal direction Q extends in the axial direction, ie parallel to the axis X of rotation.

[0078] In alternative embodiments, the fluid groove 24 may extend over any proportion of the longitudinal extent L, but preferably extends over at least 50%, in particular at least 75%.

[0079] The first guide pad 21 has an internal fluid channel 42 and a through hole 44 , via which the inlet channel 38 is fluidically connected to the fluid groove 24 .

[0080] The fluid channel 42 extends in the longitudinal direction Q and has a first end section 46 and a second end section 48 which is arranged opposite the first end section 46 in the longitudinal direction Q.

[0081] In this embodiment, the fluid channel 42 has an oval cross-section (see FIG. 5 ).

[0082] In alternative embodiments, the fluid passage 42 may have any cross-section, such as circular, polygonal, or rectangular.

[0083] The inlet channel 38 extends in the radial direction R and opens into the fluid channel 42 in a first end section 46 .

[0084] The cross section of the inlet channel 38 is circular here.

[0085] In principle, the inlet channel 38 can have any cross section. Preferably, however, the cross section is designed to be complementary to the cross section of the associated transverse channel 36 .

[0086] The through-opening 44 extends in the radial direction R and opens into the fluid channel 42 in a second end section 48 .

[0087] The cross section of the through-opening 44 is circular here.

[0088] In principle, the through-hole 44 can have any cross-section.

[0089] In the present embodiment, the inlet passage 38 and the through hole 44 are arranged to be spaced apart from each other in the longitudinal direction Q such that they do not overlap each other when viewed in the radial direction R.

[0090] In alternative embodiments, the inlet channel 38 and the through-hole 44 may each be arranged at any position in the longitudinal direction Q, or may open into the fluid channel 42 .

[0091] During operation, fluid flows from the inlet channel 38 , via the fluid channel 42 , through the through-hole 44 , into the fluid groove 24 , and is thus made available at the guide surface 30 .

[0092] With reference to Figures 7 to 9, a first guide pad 21 according to a second embodiment will now be described. The same reference numerals are used for components and features known from the above-described embodiments, and in this respect reference is made to the preceding explanations.

[0093] Compared to the first exemplary embodiment of the first guide pad 21 , the second exemplary embodiment of the first guide pad 21 has a further through-opening 44 which opens centrally in the longitudinal direction Q into the fluid channel 42 .

[0094] Of course, further through-openings 44 may open into the fluid channel 42 at any point, for example in the first end section 46 .

[0095] In principle, in alternative embodiments, the first guide pad 21 may have any number of through holes 44 .

[0096] In embodiments having multiple through-holes 44, the through-holes may be identical or individually designed.

[0097] During operation, fluid flows from the inlet channel 38 , via the fluid channel 42 , through the through-hole 44 , into the fluid groove 24 , and is thus made available at the guide surface 30 .

[0098] With reference to Figures 10 to 12, a second guide pad 22 according to a first embodiment will now be described. The same reference numerals are used for components and features known from the above-described embodiments, and in this respect reference is made to the preceding explanations.

[0099] The fluid groove 24 of the second guide pad 22 has a longitudinal extent I in the longitudinal direction Q which is approximately 95% of the longitudinal extent L of the second guide pad 22 .

[0100] Compared to the first guide pad 21 , the second guide pad 22 has no internal fluid channel 42 and no through-hole 44 .

[0101] In the illustrated embodiment, the inlet passage 38 opens into the fluid groove 24 .

[0102] During operation, fluid flows from the inlet channel 38 directly into the fluid groove 24 and is thus made available at the guide surface 30 .

[0103] With reference to Figures 13 to 15, a second guide pad 22 according to a second embodiment will now be described. The same reference numerals are used for components and features known from the above-described embodiments, and in this respect reference is made to the preceding explanations.

[0104] In contrast to the first embodiment of the second guide pad 22 , the second embodiment of the second guide pad 22 has an internal fluid channel 42 and a through-hole 44 via which the inlet channel 38 is fluidically connected to the fluid groove 24 .

[0105] The through hole 44 has an elongated cross section and is therefore slot-shaped.

[0106] In the present embodiment, the through hole 44 has a length P in the longitudinal direction Q which corresponds to approximately 95% of the longitudinal extent I of the fluid groove 24 .

[0107] In alternative embodiments, the length P may be any proportion of the longitudinal extent I of the fluid groove 24 , such as at least 50%, in particular at least 90%.

[0108] During operation, fluid flows from the inlet channel 38 , via the fluid channel 42 , through the through-hole 44 , into the fluid groove 24 , and is thus made available at the guide surface 30 .

[0109] In yet other alternative embodiments, the through hole 44 may be omitted such that the fluid groove 24 opens directly into the fluid channel 42 .

[0110] In this case, during operation, fluid flows from the inlet channel 38 , via the fluid channel 42 , directly into the fluid groove 24 , and is thus made available at the guide surface 30 .

[0111] In principle, in alternative embodiments, the fluid groove 24, the inlet channel 38, the fluid channel 42 and / or the through hole 44 may adjoin or open into the axial end face 50 of the second guide pad 22 in the longitudinal direction Q. This allows the fluid to be guided to different locations via a plurality of guide pads 21, 22 arranged one behind the other in the longitudinal direction Q and / or over a longer distance.

[0112] Additionally or alternatively, the guide pads 21 , 22 can be designed with multiple parts, in particular with sections which adjoin each other in the longitudinal direction Q.

[0113] Furthermore, in further embodiments, the inlet channel 38 can open into the axial end face 50 and thereby be fluidically connected to a correspondingly designed internal fluid line 32 .

[0114] In all embodiments, a rotary cutting tool 10 is provided in this way which, due to its particularly simple design, can be manufactured without difficulty.

[0115] The invention is not limited to the embodiments shown. Individual features of one embodiment can be combined with features of other embodiments as required, in particular independently of other features of the corresponding embodiment.

[0116] In particular, the first guide pad 21 may have features of the second guide pad 22 and vice versa.

Claims

1. A rotary cutting tool (10) comprising a tool shank (12) and at least one guide pad (21, 22), the at least one guide pad being fastened to the outer circumference (26) of the tool shank (12) and having a radial outer fluid groove (24), characterized in that: The guide pads (21, 22) have an inlet channel (38) via which the fluid groove (24) is fluidically connected to an internal fluid line (32) in the tool shank (12).

2. The rotary cutting tool (10) according to claim 1, characterized in that: The inlet channel (38) is arranged radially on the inner side of the guide pads (21, 22).

3. The rotary cutting tool (10) according to claim 1 or 2, characterized in that: The guide pads (21, 22) have an internal fluid channel (42) which extends in a longitudinal direction (Q) of the guide pads (21, 22) and via which the inlet channel (38) is fluidically connected to the fluid groove (24).

4. The rotary cutting tool (10) according to claim 3, characterized in that: The guide pads (21, 22) have at least one through hole (44), and the fluid channel (42) is fluidically connected to the fluid groove (24) via the at least one through hole.

5. The rotary cutting tool (10) according to claim 4, characterized in that The at least one through hole (44) has a circular or polygonal cross-section.

6. The rotary cutting tool (10) according to claim 4, characterized in that The at least one through hole (44) has an elongated cross section and extends over at least 50%, in particular at least 90%, of the longitudinal extent (P) of the fluid groove (24).

7. The rotary cutting tool (10) according to any one of claims 4 to 6, characterized in that When viewed in a radial direction (R), the inlet channel (38) does not overlap with the at least one through hole (44).

8. The rotary cutting tool (10) according to claim 7, characterized in that The fluid channel (42) has a first end section (46) and a second end section (48), the second end section being positioned opposite to the first end section in the longitudinal direction (Q), wherein the inlet channel (38) opens into the fluid channel (42) in the first end section (46), and the at least one through hole (44) opens into the fluid channel (42) in the second end section (48).

9. The rotary cutting tool (10) according to any one of the preceding claims, characterized in that The fluid groove (24) extends over at least 50%, in particular at least 75%, of the longitudinal extent (L) of the guide pads (21, 22).

10. The rotary cutting tool (10) according to any one of the preceding claims, characterized in that The tool shaft (12) has no fluid grooves (24) on the outer circumference (26).

11. The rotary cutting tool (10) according to any one of the preceding claims, characterized in that The internal fluid line (32) has a central main channel (34) and a transverse channel (36), wherein the main channel (34) is fluidically connected to the fluid groove (24) via the transverse channel (36).

12. The rotary cutting tool (10) according to any one of the preceding claims, characterized in that The at least one guide pad (21, 22) is fastened in a receiving groove (28) on the outer circumference (26) of the tool shank (12).

13. The rotary cutting tool (10) according to any one of the preceding claims, characterized in that At least two guide pads (21, 22) are provided distributed over the outer circumference (26).

14. The rotary cutting tool (10) according to any one of the preceding claims, characterized in that At least one cutting blade (14) is fastened in the region of an axial end (16) of the tool shank (12).

15. The rotary cutting tool (10) according to any one of the preceding claims, characterized in that The at least one guide pad (21, 22) protrudes radially relative to the outer circumference (26).

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