Toolholder and cutting tool

Abstract

A toolholder has a plurality of receptacles for at least one respective cutting insert. For each receptacle, the toolholder comprises a clamping element associated with the receptacle and a hydraulic channel associated with the corresponding clamping element. Each clamping element is hydraulically adjustable between a closed position and an opened position via the associated hydraulic channel. Furthermore, the toolholder is configured such that the clamping elements in the closed position clamp the associated cutting inserts into the corresponding receptacle for the cutting operation and thus fix them to the toolholder and release them in the opened position so that the cutting inserts can be detached from the toolholder, in particular in a tool-free manner. Furthermore, a cutting tool is provided having a toolholder according to any one of the preceding claims and at least one cutting insert.

Claims

1. A toolholder having a plurality of receptacles for at least one respective cutting insert, wherein the toolholder comprises for each receptacle a clamping element associated with the receptacle and a hydraulic channel associated with the corresponding clamping element, wherein each clamping element is hydraulically adjustable between a closed position and an opened position via the associated hydraulic channel, wherein the toolholder is configured such that the clamping elements clamp the associated cutting inserts in the receptacles in the closed position for the cutting operation and thus fix them to the toolholder and release them in the opened position, such that the cutting inserts can be detached from the toolholder.

2. The toolholder according to claim 1, wherein the hydraulic channels are part of a hydraulic system and are fluidly connected to one another.

3. The toolholder according to claim 2, wherein the toolholder comprises a filling opening for filling the hydraulic system, wherein the filling opening is arranged on a front face of the toolholder that is provided so as to oppose a prime mover when the toolholder is mounted on the prime mover for the cutting operation.

4. The toolholder according to claim 1, wherein the toolholder has an adjustment element by means of which the pressure of the hydraulic system can be adjusted.

5. The toolholder according to claim 4, wherein the adjustment element can be adjusted between a first position in which the clamping elements are in the opened position and a second position in which the clamping elements are in the closed position.

6. The toolholder according to claim 4, wherein the adjustment element is arranged on a side of the toolholder that is provided so as to not oppose a prime mover when the toolholder is mounted on the prime mover for the cutting operation.

7. The toolholder according to claim 1, wherein the clamping elements are plungers, each of which is slidably supported in a cylinder recess.

8. The toolholder according to claim 1, wherein the toolholder for each clamping element comprises a resetting element associated with the corresponding clamping element that biases the associated clamping element to the opened position or the closed position.

9. The toolholder according to claim 1, wherein the cutting inserts are detached from the toolholder in a tool-free manner.

10. The toolholder according to claim 1, wherein the toolholder is manufactured by means of an additive manufacturing process.

11. The toolholder according to claim 10, wherein the additive manufacturing process is 3D printing.

12. A cutting tool having a toolholder according to claim 1 and at least one cutting insert (22).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further advantages and features will emerge from the following description and from the accompanying drawings. The figures show:

[0019] FIG. 1 in a side view, a cutting tool according to the invention with a toolholder according to the invention and a plurality of cutting inserts,

[0020] FIG. 2 in a plan view, the cutting tool from FIG. 1,

[0021] FIG. 3 the cutting tool in a sectional view along the plane C-C in FIG. 1,

[0022] FIG. 4 the cutting tool in a sectional view along the plane B-B in FIG. 1,

[0023] FIG. 5 the cutting tool in a sectional view along the plane A-A in FIG. 1 in a closed position in which the cutting inserts are fixed,

[0024] FIG. 6 the cutting tool in a sectional view along the plane A-A in FIG. 1 in an opened position in which the cutting inserts are released,

[0025] FIG. 7 the cutting tool according to a further embodiment in a sectional view along the plane A-A in FIG. 1 in a closed position in which the cutting inserts are fixed, and

[0026] FIG. 8 the cutting tool according to the further embodiment in a sectional view along the plane A-A in FIG. 1 in an opened position in which the cutting inserts are released.

DETAILED DESCRIPTION

[0027] In FIG. 1, a cutting tool 10 is shown with a toolholder 20 and a plurality of cutting inserts 22, each arranged in a receptacle 24 of the toolholder 20.

[0028] The toolholder 20 is manufactured by means of an additive manufacturing process, for example by means of a 3D printing process.

[0029] In the illustrated embodiment, the cutting tool 10 is a turntable mill having six receptacles 24 (see FIG. 2) for six respective cutting inserts 22 and an axis of rotation R about which the turntable mill rotates in the cutting operation.

[0030] Generally, the cutting tool 10 can be any cutting tool, in particular any rotating cutting tool.

[0031] Additionally or alternatively, in an alternative embodiment, the cutting tool 10 can comprise any number of receptacles 24, but at least two.

[0032] The cutting inserts 22 each have a cutting body 26 (see FIG. 5), which is configured for machining a workpiece, and a tensioning element 28, by means of which the cutting body 26 is fastened to the toolholder 20.

[0033] To fasten the cutting inserts 22, the toolholder 20 has six clamping elements 30, each associated with a respective receptacle 24 and configured so as to clamp the tensioning element 28 arranged in the corresponding receptacle 24, as will be explained in further detail below.

[0034] In an alternative embodiment, more than one cutting insert 22 can be arranged in each receptacle 24, which can be clamped together for fastening by the clamping element 30 associated with the receptacle 24.

[0035] The cutting inserts 26 in the present embodiment are indexable inserts, and the tensioning elements 28 are tensioning bolts.

[0036] In principle, the cutting body 26 and the tensioning elements 28 can each be designed as desired.

[0037] In an alternative embodiment, the cutting inserts 22 do not have separate tensioning elements 28. In this case, the clamping elements 30 are respectively configured so as to clamp the corresponding cutting body 26 directly or via an integral piece in the associated receptacle 24 with a clamping element 28 connected to the cutting body 26.

[0038] The clamping elements 30 are each part of a clamping mechanism 32 that is associated with the corresponding receptacle 24 and hydraulically actuatable.

[0039] For this purpose, the toolholder 20 comprises a hydraulic system 34 having a preferably annular reservoir 36 (see FIG. 3), as well as six hydraulic channels 38, each associated with a clamping mechanism 32 and fluidly connected to the reservoir 36.

[0040] In operation, the hydraulic system 34 is filled with a hydraulic fluid that can be supplied to or removed from the hydraulic system 34 via a filling opening 40 (see FIG. 2).

[0041] The filling opening 40 is arranged on a front face 42 of the toolholder 20, which opposes a prime mover (not shown) when the toolholder 20 is fastened to the prime mover for the cutting operation.

[0042] Furthermore, the hydraulic system 34 has an adjustment channel 44 (see FIG. 4) extending from the reservoir 36 to a circumferential side 46 of the toolholder 20 and in which an adjustment element 48 of the toolholder 20 is arranged.

[0043] In the present embodiment, the adjustment element 48 is a compression screw, which can be screwed into the adjustment channel 44 in an adjustment direction S, in order to increase the force with which the adjustment element 48 presses on the hydraulic fluid in the hydraulic system 34, and thus to increase the pressure in the hydraulic system 34, or which can be released counter to the adjustment direction S, in order to reduce the force with which the adjustment element 48 presses on the hydraulic fluid in the hydraulic system 34, and thus to lower the pressure in hydraulic system 34.

[0044] Unlike the front face 42, the circumferential side 46 does not lie opposite the prime mover when the toolholder 20 is fastened to the prime mover for the cutting operation. Thus, the adjustment element 48 is also accessible on the prime mover in the assembled state of the toolholder 20.

[0045] The clamping mechanisms 32 are designed so as to be substantially identical to one another. Thus, the construction and function of the clamping mechanisms 32 will be exemplified below using a clamping mechanism 32 and with reference to FIGS. 5 and 6.

[0046] The clamping mechanism 32 has a cylinder recess 50 in which the clamping element 30 is axially slidably supported and opens into the receptacle 24 with one axial end.

[0047] At the opposite axial end, the cylinder recess 50 is closed by a plug 52.

[0048] Between the plug 52 and the clamping element 30, a biasing element 54 is arranged in the form of a spiral spring, which elastically biases the clamping element towards the receptacle 24.

[0049] The hydraulic channel 38 associated with the clamping mechanism 32 opens into the cylinder recess 50 and is configured so as to hydraulically adjust the clamping element 30 in the axial direction.

[0050] In order to ensure that hydraulic fluid remains in the hydraulic system 34 during operation and does not escape into receptacle 24 via the cylinder recess 50, the clamping mechanism 32 can comprise a sealing device, such as a piston washer.

[0051] In this context, the clamping element 30 forms a plunger that can be adjusted between a closed position (see FIG. 5), in which an axial end 56 of the clamping element 30 projects into the receptacle 24 and clamps the cutting insert 22 in the receptacle 24, and an opened position (see FIG. 6) in which the clamping element 30 releases the cutting insert 22 so that it can be removed from the receptacle 24 and thus separated from the toolholder 20.

[0052] In the present embodiment, the closed position is defined by a low pressure level in the hydraulic system 34, such that the spring force of the resetting element 54 is sufficient in order to press the clamping element 30 against the cutting insert 22 in the receptacle 24 counter to the hydraulic pressure.

[0053] The axial end 56 engages with a notch 58 in the tensioning element 28 and thus abuts the tensioning element 28, whereby the cutting insert 22 is reliably clamped and fixed to the toolholder 20.

[0054] The opened position is defined by a high pressure level in the hydraulic system 34, which is large enough for the clamping element 30 to compress the resetting element 54 and thus be adjusted towards the plug 52.

[0055] In order to prevent the cutting insert 22 from falling out of the receptacle 24 in the opened position due to its own weight, the toolholder 20 comprises a retaining device 60 associated with the receptacle 24, which holds the cutting insert 22 in the receptacle 24 under a bias.

[0056] For this purpose, the retaining device 60 has a pressure piece 62 in the form of a ball and an elastic element 64 in the form of a spiral spring, which pushes the pressure piece 62 against the cutting insert 22 with low pressure.

[0057] The tensioning element 28 here has a position notch 66, with which the pressure piece 62 can engage in order to keep the tensioning element 28 in a defined position.

[0058] The position notch 66 is preferably positioned such that the tensioning element 28 is arranged in the receptacle 24 when the pressure piece 62 engages with the position notch 66, such that the cutting insert 22 is reliably fixed when the clamping element 30 is adjusted from the opened position into the closed position.

[0059] In order to fasten the cutting inserts 22 to the toolholder 20, the clamping elements 30 are initially adjusted together into the opened position in that the hydraulic pressure is increased by setting the adjustment element 48 to the high pressure level.

[0060] The position which the adjustment element 48 occupies in the opened position of the clamping elements 30 defines a first position of the adjustment element 48.

[0061] Subsequently, the cutting inserts 22 are inserted into the receptacles 24 in which they are held in position by means of the retaining devices 60.

[0062] Finally, the clamping elements 30 are adjusted together into the closed position, in that the hydraulic pressure is reduced by setting the adjustment element 48 to the low pressure level.

[0063] The position which the adjustment element 48 occupies in the closed position of the clamping elements 30 defines a second position of the adjustment element 48.

[0064] In this way, all cutting inserts 22 are effectively clamped in the receptacles 24 and thus securely fastened to the toolholder 20 for the cutting operation.

[0065] In this context, it is advantageous to have a display associated with the adjustment element 48 which marks the first and second positions, such that the adjustment element 48 can be reliably set to these positions.

[0066] Additionally, or alternatively, the toolholder 20 can comprise a pressure display indicating the hydraulic pressure in the hydraulic system 34, in particular the high pressure level and the low pressure level to which the opened or closed position is associated.

[0067] In order to separate the cutting inserts 22 from the toolholder 20 again, the clamping elements 30 are adjusted together to the opened position in that the adjustment element 48 is reset to the first position.

[0068] As a result, the cutting inserts 22 are no longer clamped in the receptacles 24, but are merely held in the receptacles 24 by the retaining devices 60 such that the cutting inserts 22 can be removed from the receptacles 24 with little force by hand and thus without tools.

[0069] A cutting tool according to a second embodiment will now be described based on FIGS. 7 and 8. For the components known from the above embodiment, the same reference numerals are used, and reference is made in this respect to the foregoing explanations.

[0070] By contrast to the embodiment shown in FIGS. 5 and 6, in which the clamping elements 30 are in the opened position when the hydraulic pressure is at the high pressure level, and in the closed position when the hydraulic pressure is at the low pressure level, the clamping mechanisms 32 of the toolholder 20 are designed according to the second embodiment such that the clamping elements 30 are in the closed position when the hydraulic pressure is at the high pressure level and in the opened position when the hydraulic pressure is at the low pressure level.

[0071] The hydraulic channels 38 here respectively open into the cylinder recess 50 between the associated clamping element 30 and the plug 52, such that the clamping element 30 is pushed towards the receptacle 24 by the hydraulic pressure.

[0072] In this context, the resetting elements 54 are arranged so as to bias the clamping elements 30 into the opened position.

[0073] In the present embodiment, the resetting elements 54 are arranged in receptacle 24 between a front face 68 of the tensioning element 28 and an opposing wall 70 of the receptacle 24 when the cutting inserts 22 are inserted into the receptacle 24.

[0074] Thus, the resetting elements 54 push the tensioning element 28 away from the wall 70 and the clamping element 30 away from the receptacle 24, respectively.

[0075] Furthermore, according to the second embodiment, the toolholder 20 has no retaining devices 60.

[0076] Of course, according to an alternative embodiment, the toolholder 20 can have corresponding retaining devices 60.

[0077] In all embodiments, in this manner, a toolholder 20 as well as a cutting tool 10 with a toolholder 20 is provided, to which cutting inserts 22 can be fastened and replaced with little effort.

[0078] The hydraulic system 34 ensures that all clamping elements 30 are reliably adjustable between the closed and the opened positions together via a single adjustment element 48.

[0079] The invention is not limited to the embodiments shown. Individual features of one embodiment can in particular be combined as desired with features of other embodiments, in particular independently of the other features of the corresponding embodiments.

LIST OF REFERENCE NUMERALS

[0080] 10 Cutting tool [0081] 20 Toolholder [0082] 22 Cutting inserts [0083] 24 Receptacle [0084] 26 Cutting body [0085] 28 Tensioning element [0086] 30 Clamping element [0087] 32 Clamping mechanism [0088] 34 Hydraulic system [0089] 36 Reservoir [0090] 38 Hydraulic channel [0091] 40 Filling opening [0092] 42 Front face [0093] 44 Adjustment channel [0094] 46 Circumferential side [0095] 48 Adjustment element [0096] 50 Cylinder recess [0097] 52 Plug [0098] 54 Resetting element [0099] 56 Axial end [0100] 58 Notch [0101] 60 Retaining device [0102] 62 Pressure piece [0103] 64 Elastic element [0104] 66 Position notch [0105] 68 Front face [0106] 70 Wall