Machining tool

Abstract

The invention relates to a machining tool with which a cutting machining at a workpiece surface (25) or in a workpiece bore can be carried out when the tool is rotated about a tool axis (W), wherein the machining tool has at least one flexible damping element (9) and wherein, during the cutting machining, the machining tool, via its damping element (9), lies against the workpiece surface (25) or the workpiece bore, whereby tool vibrations and workpiece vibrations can be reduced. According to the invention, the tool has a coolant channel (27) which has at least one channel outlet (29) in the region of the contact point of the damping element (9) with the workpiece surface (25).

Description

Technical Field

[0001] This invention relates to machining tools. Background Technology

[0002] For example, such a machining tool can be implemented as a milling tool for plunge milling or face milling. In this case, the tool may have a face cutting edge. During milling, the milling tool rotates about a tool axis perpendicular to the workpiece surface and moves along the workpiece surface with a feed motion transverse to the tool axis.

[0003] During milling, a cutting force is applied to the end face of the milling cutter. This cutting force causes the cutter to shift translationally, resulting in tool bending. The tool remains bent until sufficient preload is established, at which point it quickly returns to its original position. This process repeats very rapidly during milling, causing tool vibration and consequently affecting the surface quality of the workpiece.

[0004] Tool holders equipped with vibration damping measures are known from EP 2 399 698 B1. Tools for machining metal with vibration damping measures are known from EP 1 339 517 B1. Drills with vibration dampers are known from EP 1 292 417 B1. Summary of the Invention

[0005] The purpose of this invention is to provide a machining tool in which tool vibration during cutting can be avoided in a structurally simple manner.

[0006] This invention generally relates to machining tools that, when rotated about their axis, can be used to perform machining on the surface of a workpiece or in a workpiece hole. According to one aspect of the invention, the machining tool has at least one yielding / flexible / flexible damping element. During cutting, the machining tool comes into contact with the workpiece surface or workpiece hole via its damping element, particularly under pressure, thereby reducing tool and workpiece vibration.

[0007] The core of this invention lies in applying a preload to the workpiece and preventing vibration by means of a damping element positioned at the machining tool, through a clamping force. The machining tool can be, for example, a plunge milling cutter. In this case, the cutting tool makes its first contact with the workpiece via the damping element. The clamping force applied by the damping element increases with the tool feed.

[0008] Alternatively, when milling a workpiece from one side (in a plane), a machining tool can be used. In this method, the milling tool makes initial contact with the workpiece at the cutting edge. As the tool continues to penetrate the workpiece material, a damping element presses against the workpiece. The clamping force generated in this way prevents vibration of the workpiece or the tool.

[0009] In one technical embodiment, the damping element in the non-use position can extend beyond at least one tool cutting edge or tip. During the cutting process, the damping element can be adjusted to the use position, wherein, with the extension removed and preferably with the establishment of a return force, the damping element is adjusted to the height of the tool cutting edge to ensure cutting action / cutting engagement between the tool cutting edge and the workpiece surface.

[0010] Preferably, the damping element is supported in the machining tool in a stroke-adjustable manner. In the non-use position, the damping element can be supported against the tool's forward stop (Vorhub-Anschlag) by means of a damping mass. Furthermore, the damping element can retract from the forward stop in the use position, especially when a return force is established. When force is introduced during cutting, energy absorption occurs, wherein the damping mass deforms, and the introduced force is at least partially eliminated.

[0011] In a preferred embodiment variation, during machining, the damping element may be in contact with the workpiece surface or workpiece hole in the axial and / or radial directions, especially under pressure. In this case, the damping element's stroke can be adjusted between a used position and an unused position in the axial and / or radial directions.

[0012] In a specific implementation variation, the cutting edge of the tool can be an end face cutting edge, which is arranged together with the vibration damping element at the tip of the machining tool.

[0013] To achieve the lifting motion, the damping element can be adjusted between a forward stop and a return stop. The axial or radial distance between the forward stop and the return stop defines the maximum stroke length.

[0014] In the technical implementation, damping elements, forward stops, return stops, and / or damping mass blocks may be components of the stroke adjustment unit. The stroke adjustment unit may be arranged within the receiving profile of the machining tool, particularly a hollow cylindrical profile. The hollow cylindrical receiving profile may be open at the end side at the tool tip.

[0015] Preferably, the forward stop can be implemented as a stop sleeve, through which the damping element can be guided with adjustable stroke. When axial clearance is formed, the return stop can be spaced axially from the forward stop. Furthermore, the damping element can have a large-diameter annular flange that works in conjunction with the forward and return stops. The large-diameter annular flange can overlap the end of the stop sleeve and be guided with adjustable stroke between the end of the stop sleeve and the return stop.

[0016] The damping mass can be, for example, an elastomer and / or can be supported between the return stop and the damping element, especially the large-diameter annular flange of the damping element.

[0017] Regarding functional expansion, it is preferable that the forward stop and / or return stop can be height-adjustable, for example, along the tool axis. In this case, the positions of the forward stop and / or return stop can be set, thereby allowing the positioning of the used and / or unused positions to be changed in the axial direction.

[0018] In a variation of the implementation, the damping element may be a sleeve-shaped hollow profile that is guided coaxially along the tool axis in a stroke-adjustable manner. Alternatively and / or additionally, the damping element may have an element head that can contact the workpiece surface during machining.

[0019] Preferably, the machining tool is equipped with a coolant supply section to cool or lubricate the contact area between the damping element and the workpiece. Preferably, the coolant supply section may have coolant channels within the tool. The coolant channels may have at least one channel outlet in the region of contact between the damping element and the workpiece surface. Preferably, the hollow profile of the damping element is part of the coolant channels. In this case, at least one channel outlet may be constructed in the head of the damping element.

[0020] In a variation of the first embodiment, the head of the damping element may be spherically shaped to have a vertex portion located on the tool axis. During cutting, the head of the damping element comes into point-like contact with the workpiece surface at its vertex portion under pressure.

[0021] As an alternative, the damping element can be constructed in a ring shape, so that a ring-shaped contact is generated under pressure during machining. Attached Figure Description

[0022] The embodiments are illustrated below with the aid of accompanying drawings. Wherein:

[0023] Figure 1 and Figure 2 The different views of the milling tool are shown accordingly;

[0024] Figures 3 to 9 Different views of other embodiments are shown accordingly. Detailed Implementation

[0025] exist Figure 1 The image shows a partial perspective view of the milling cutter in the region of its tip 1. The milling cutter has a columnar base with a clamping shank (not shown) on its side opposite to the tip 1. At the tip 1 of the milling cutter, a total of three circumferentially distributed end face cutting edges 3, 5, and 7 are arranged in a circumferentially distributed manner.

[0026] The damping element 9 can be adjusted in stroke between the forward stop 11 and the return stop 13, with a maximum adjustable stroke length h. Figure 2).exist Figure 2 In this design, the forward stop 11 is implemented as a stop sleeve, in which the damping element 9 is guided. The stop sleeve 11 is screwed into the hollow cylindrical receiving portion 10 of the milling tool, which is open at the end side at the tool tip 1. With an axial clearance 14 formed, the return stop 13 is spaced apart from the end side 15 of the stop sleeve by an axial distance a. The damping element 9 is implemented as a sleeve-shaped hollow profile, whose stroke can be adjusted coaxially along the tool axis W. The damping element 9 has a large-diameter annular flange 17 on one side, which overlaps the end side 15 of the stop sleeve and allows for stroke adjustment between the end side 15 of the stop sleeve and the return stop 13. Furthermore, according to Figure 2 The damping mass 19 is constructed as an elastic body and is supported between the return stop 13 and the large-diameter annular flange 17 of the damping element 9.

[0027] exist Figure 2 In this configuration, both the stop sleeve 11 and the return stop 13 are threadedly engaged 21 with the hollow cylindrical tool receiving portion 10. In this way, the axial position of the stop sleeve 11 and / or the return stop 13 can be set.

[0028] exist Figure 2 The damping element 9 is shown in the non-use position N. In the non-use position N, the element head 23 of the damping element extends beyond the end face cutting edges 3, 5, and 7 by an extension amount Δx.

[0029] exist Figure 3 The diagram shows a milling cutter during the cutting of workpiece surface 25. In this case, the damping element 9 is in the use position G, in which the damping element 9 is adjusted to the height of the tool cutting edges 3, 5, 7 when the extension amount Δx is canceled and when the return force is established, so as to ensure the cutting action of the tool cutting edges 3, 5, 7 on the workpiece surface 25.

[0030] exist Figure 3 In the position G shown in the figure, the vibration damping element 9 has its element head 23 pressed against the workpiece surface 25 under pressure, thereby reducing the vibration of the tool and the workpiece.

[0031] To prevent damage to the workpiece surface 25 at the contact point between the damping element 9's head 23 and the workpiece surface 25, a coolant supply system with coolant channels 27 is provided for the milling cutter. The coolant channels extend coaxially with the cutter axis W within the milling cutter. The hollow internal profile of the damping element 9 is also part of the coolant channels 27, through which coolant is directly guided to the element head 23, and then guided to the contact point via channel outlet 29.

[0032] Here, the stroke length h of the damping element provided by the stroke adjustment unit must be greater than the extension amount Δx of the damping element 9 present in the non-use position N.

[0033] Figure 4 China corresponds to Figure 2 The view illustrates another embodiment variation. Their construction and operating principles are the same as those in the foregoing exemplary embodiments. Figure 1 or Figure 2 different, Figure 4 The element head 23 is not flat, but spherically protruding; that is, the apex S is located on the tool axis W. Here, the channel outlet 29 is located directly at the apex S. Compared to the previous embodiment, this method induces a substantially point-like contact under pressure between the damping element 9 and the workpiece surface 25.

[0034] Figure 5 Another embodiment is shown, in which the milling cutter does not have end face cutting edges 3, 5, 7, but instead has side cutting portions 31, 33 axially spaced from the cutter tip 1. Figure 5 The milling cutter shown performs milling on the workpiece side 35, which is oriented parallel to the cutter axis W. At the start of the cutting process, the cutter makes initial contact with the workpiece surface 25 via the cutter side cutting portions 31 and 33 during the feed motion. As the cutter continues to penetrate the workpiece material, a time-delayed contact occurs between the damping element 9 and the workpiece surface 25 under pressure.

[0035] exist Figure 6 Another machining tool is shown. Unlike the previous embodiment, in... Figure 6 In this configuration, the damping element 9 is constructed in a ring shape. In this case, during cutting, a ring-shaped contact is generated under pressure, wherein the tool cutting edge 37 is constructed radially outside the ring-shaped damping element 9. Figure 6 In this configuration, the outlet 29 of the coolant passage 27 is directly positioned within the annular damping element 9. In contrast, in... Figure 7 In this configuration, the channel outlet 29 is positioned within the annular damping element 9, and also radially inward of the annular damping element 9. This differs from the previous configuration. Figure 8 In this design, the damping element 9 does not have a channel outlet 29, while the channel outlet 29 of the coolant channel 27 is located only radially inside the annular damping element 9.

[0036] Figure 9 Another embodiment is shown, in which the damping element 9 is compliantly supported not only in the axial direction but also in the radial direction. Thus, during the cutting process, the milling tool can also be additionally laterally supported on the workpiece.

[0037] List of reference numerals

[0038] 1 blade tip

[0039] 3, 5, 7 cutting edges

[0040] 9. Vibration damping components

[0041] 10. Contains outline

[0042] 11 Stop sleeve

[0043] 13 Return Stop

[0044] 15. Stop sleeve end side

[0045] 17. Larger diameter annular flange

[0046] 19 Vibration damping mass blocks

[0047] 21 Threaded joint

[0048] 23 Component Head

[0049] 25. Workpiece surface

[0050] 27 Coolant passage

[0051] 29 Exit Channel

[0052] 31, 33 Cutting edge of the tool

[0053] 35. Side of the workpiece

[0054] 37 Cutting edge of the tool

[0055] a Axial spacing

[0056] h Travel length

[0057] Δx extension amount

[0058] G Location

[0059] N Non-use location

[0060] S is the vertex.

Claims

1. A machining tool that, when rotating about a tool axis (W), can perform cutting operations at a workpiece surface (25), wherein, The machining tool has at least one yieldable damping element (9), wherein during cutting, the machining tool abuts against the workpiece surface (25) via its damping element (9), thereby reducing tool vibration and workpiece vibration. The tool is characterized by having a coolant channel (27) having at least one channel outlet (29) in the region of contact between the damping element (9) and the workpiece surface (25). The damping element (9) is adjustable in stroke between a forward stop (11) and a return stop (13), wherein the forward stop (11) is implemented as a stop sleeve through which the damping element (9) passes in an adjustable stroke manner. A damping mass (19) is supported between the return stop (13) and the damping element (9). The forward stop (11) and the return stop (13) are height-adjustable in the axial direction to set a working position (G) and a non-working position (N).

2. The machining tool according to claim 1, characterized in that, The return stop (13) is spaced apart from the forward stop (11) by an axial spacing (a) with an axial clearance (14). The damping element (9) has a large-diameter annular flange (17) that overlaps the end side (15) of the stop sleeve (11) and can be adjusted by a stroke length (h) between the end side (15) of the stop sleeve and the return stop (13).

3. The machining tool according to claim 1, characterized in that, The damping element (9) extends beyond at least one cutting edge (3, 5, 7) or tip (1) of the tool in the axial direction in the non-use position (N), and the damping element (9) is adjusted to the use position (G) during the cutting process.

4. The machining tool according to claim 1, characterized in that, In the operating position (G), the damping element (9) is adjusted to the height of the tool cutting edge (3, 5, 7) to ensure cutting contact between the tool cutting edge (3, 5, 7) and the workpiece surface (25).

5. The machining tool according to claim 3 or 4, characterized in that, The damping element (9) is supported in the cutting tool in a way that allows for adjustable stroke. In the non-use position (N), the damping element (9) presses against the tool's forward stop (11) by means of the damping mass block (19). The damping mass block (19) eliminates the energy introduced during cutting by deforming.

6. The machining tool according to claim 3 or 4, characterized in that, The damping element (9) retracts from the forward stop (11) by a stroke length (h) in the use position (G).

7. The machining tool according to claim 3 or 4, characterized in that, During the cutting process, the damping element (9) is in contact with the workpiece surface (25) along the axial direction.

8. The machining tool according to claim 3 or 4, characterized in that, The damping element (9) can adjust its stroke along the axial direction.

9. The machining tool according to claim 5, characterized in that, The cutting edges (3, 5, 7) of the cutting tool are end face cutting edges. The damping element (9) and the end face cutting edges (3, 5, 7) are all arranged at the tip (1) of the machining tool.

10. The machining tool according to claim 5, characterized in that, At least one of the damping element (9), forward stop (11), return stop (13) and damping mass block (19) is a component of a stroke adjustment unit that can be installed in a hollow cylindrical receiving profile (10) of the machining tool that is open at the end side at the tool tip (1).

11. The machining tool according to claim 1 or 2, characterized in that, The damping element (9) is a sleeve-shaped hollow profile that can be adjusted at least along the tool axis (W).

12. The machining tool according to claim 1 or 2, characterized in that, The damping element (9) has an element head (23) that can contact the workpiece surface (25).

13. The machining tool according to claim 1 or 2, characterized in that, The hollow profile of the damping element (9) is part of the coolant channel (27), and at least one channel outlet (29) is constructed in the region of the element head (23) of the damping element (9).

14. The machining tool according to claim 1 or 2, characterized in that, The head (23) of the damping element (9) is constructed in an arch shape with a vertex (S) located on the tool axis (W), through which a point-like contact with the workpiece surface (25) can be basically established.

15. The machining tool according to claim 1 or 2, characterized in that, The damping element (9) is constructed in a ring shape to produce a ring-shaped contact during cutting. The cutting edge (37) of the tool is arranged radially outside the ring-shaped damping element (9), and at least one channel outlet (29) of the coolant channel (27) is located in the ring-shaped damping element (9).

16. The machining tool according to claim 15, characterized in that, At least one channel outlet (29) of the coolant channel (27) is located radially inside the annular damping element (9).

17. The machining tool according to claim 1 or 2, characterized in that, The machining tool is a milling tool used for plunge milling, wherein the first tool contact between the tool and the workpiece surface (25) is achieved by a damping element (9) during the feed motion, and the clamping force generated in the damping element (9) increases as the tool feeds.

18. The machining tool according to claim 1 or 2, characterized in that, The cutting tool is a milling tool. The tool is used to mill the side (35) of the workpiece that is oriented parallel to the tool axis (W). During the feed motion, the tool makes the first contact between the tool and the side (35) of the workpiece through the cutting edge (37). The damping element (9) only comes into contact with the surface (25) of the workpiece when the tool continues to penetrate into the workpiece material.

19. The machining tool according to claim 1, characterized in that, The cutting tool comes into contact with the workpiece surface (25) under pressure via its damping element (9).

20. The machining tool according to claim 3, characterized in that, The damping element is adjusted to the working position when the axial extension (Δx) is canceled and when the return force is established.

21. The machining tool according to claim 5, characterized in that, During the cutting process, the damping element (9) is in contact with the workpiece surface (25) along the axial direction.

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