Rotary tool

Abstract

The invention relates to a rotary tool (10), the tool body (12) of which extends between a driven end (16) and a front end (18) along a central axis of rotation (14), the rotary tool comprising: a receiving region for receiving a deburring element (30) which is movable relative to the axis of rotation along a radial axis of movement between an inner position and an outer position; and a fluid channel (20) which is fluidically connected to the receiving region in order to apply fluid pressure to the deburring element, wherein the rotary tool has a mechanical spring which generates a preloading force and pushes the deburring element radially outwards into the outer position and preloads the deburring element in the outer position, and wherein, depending on a fluid pressure prevailing in the fluid channel, an additional force acting radially outwards can be applied or is applied to the deburring element.

Description

[0001] Applicant:

[0002] botek Präzisionsbohrtechnik GmbH

[0003] Längenfeldstraße 4

[0004] 72585 Riederich

[0005] 06400052WG 19.12.2025

[0006] TLG / TLG

[0007] Title: Rotary Tool

[0008] Description

[0009] The invention relates to a rotary tool which extends with a tool body along a central axis of rotation between a driven end and a front end, with a receiving area for receiving a deburring element which is movable with respect to the axis of rotation along a radial axis of movement between an inner position and an outer position, with a fluid channel which is fluidly connected to the receiving area for applying fluid pressure to the deburring element.

[0010] From EP 1 863 610 B1, a rotary tool with a deburring element is known which can be moved from an inner position to an outer position by means of fluid pressure. In the outer position, a deburring edge of the deburring element projects beyond the circumference of a tool body, so that the deburring edge can remove a workpiece burr and / or create a chamfer in a workpiece.

[0011] The present invention is based on the objective of providing a rotary tool that is suitable for a wide variety of operating conditions.

[0012] This task is solved in a rotary tool of the type mentioned above by the fact that the rotary tool has a mechanical spring which generates a preload force and pushes the deburring element radially outwards into the outer position and preloads the deburring element in the outer position, whereby, depending on a fluid pressure in the fluid channel, the deburring element can be subjected to or is subjected to an additional force acting radially outwards.

[0013] The rotary tool according to the invention has a deburring element which, regardless of the operating conditions, is subjected to a preload force generated by the mechanical spring. This spring forces the deburring element into its outer position, so that it assumes a defined position along its axis of movement, at least in a state where the rotary tool is not engaged with a workpiece. When the rotary tool engages with a workpiece, the mechanical spring generates a preload force that presses a deburring edge of the deburring element against the workpiece area to be deburred. According to the invention, the rotary tool can be used in this way without any fluid pressure in the fluid channel. In the simplest case, the rotary tool according to the invention can therefore be operated without an external fluid supply.

[0014] Furthermore, the rotary tool according to the invention can be used in cases where a cooling and / or lubricating fluid is required, which is supplied to and exits the fluid channel of the rotary tool, for example, to cool and / or lubricate an engagement point of a deburring edge of the deburring element with a workpiece. It is possible to use comparatively low fluid pressures, so that the additional force acting on the deburring element due to the low fluid pressure is comparatively low, and in particular can be smaller than the preload force provided by the mechanical spring. Nevertheless, even a low additional force contributes to stabilizing a deburring process and counteracting an undesired radial inward retraction of the deburring element.

[0015] The rotary tool according to the invention can also be used in cases where it is desired to apply a particularly high compressive force to the deburring element, for example, for the engagement of the rotary tool in a workpiece made of a particularly hard material. In these cases, a higher fluid pressure can be provided, thus making a correspondingly increased additional force available. This additional force is, for example, equal to the preload force generated by the mechanical spring, or the additional force is greater than the preload force. It is also possible to vary the additional force acting on the deburring element by changing the fluid pressure, for example, to enable the production of chamfers with a predetermined chamfer profile.

[0016] The rotary tool according to the invention is therefore suitable for a wide variety of operating conditions. These operating conditions include different fluids, different fluid pressures, different workpiece geometries, and different workpiece materials.

[0017] According to a preferred embodiment, the mechanical spring is a compression spring. A compression spring, in particular a helical compression spring, can be easily arranged in a rear region of the deburring element, i.e., on a side of the deburring element facing away from the deburring edge.

[0018] A particularly simple positioning of the mechanical spring results when it passes through the fluid channel, especially transversely to a longitudinal extent of the fluid channel. This has the advantage that, at least for a portion of the mechanical spring, the installation space already provided by the fluid channel can be utilized. This arrangement is particularly preferred when the mechanical spring is fluid-permeable in the direction of flow of the fluid channel, as is the case, for example, with a helical compression spring.

[0019] It is further preferred if the mechanical spring is supported at a supporting end against a counter bearing of the tool body and applies the preload force to a preload force-bearing surface of the deburring element at a pressing end. This allows for direct force transmission of the preload force into the deburring element while requiring minimal installation space.

[0020] It is further preferred if the counter bearing is provided by a local enlargement of the fluid channel. Such an enlargement can be produced in a simple manner, for example by a bore machined into the tool body.

[0021] Furthermore, it is possible that the local extension accommodates a section of the mechanical spring, with a boundary of the local extension serving as a positioning and guiding surface for the mechanical spring.

[0022] For example, local extension is provided by a hollow cylindrical section of the tool body.

[0023] It is particularly preferred if the preload force absorption surface is annular, which enables the mechanical spring to introduce force into the deburring element in a manner concentric to the axis of movement.

[0024] It is further preferred that the deburring element has an additional force-bearing surface that can be subjected to, or is subjected to, fluid pressure. This allows the deburring element to be subjected to the pressure of the fluid flowing through the fluid channel in a defined manner. For example, the additional force-bearing surface is circular and concentric to the axis of movement of the deburring element. It is also possible that the aforementioned preload force-bearing surface of the deburring element can be subjected to fluid pressure, and that the additional force thus results from the product of the fluid pressure and the sum of the preload force-bearing surface and the additional force-bearing surface.

[0025] It is particularly preferred that the preload force absorption surface and the additional force absorption surface are arranged concentrically to each other with respect to the axis of movement, so that a centric force introduction into the deburring element can be provided under all operating conditions, i.e. a force introduction which is collinear to the axis of movement of the deburring element.

[0026] It is further preferred if the preload force-bearing surface and the additional force-bearing surface are arranged offset from each other along the axis of movement. This makes it possible to provide an additional bearing surface for an end of the mechanical spring facing the deburring element in the area of ​​an offset between the aforementioned surfaces. This bearing surface is, for example, cylindrical.

[0027] In principle, it is possible for the fluid pressure to be provided solely by compressed air. Preferably, the fluid pressure is provided by compressed air containing oil mist, which is used for minimum quantity lubrication. However, it is also possible for the fluid pressure to be provided by a (liquid) emulsion.

[0028] Another preferred embodiment provides that the rotary tool has a retaining insert for holding the deburring element on the tool body, wherein the retaining insert is detachably connected to the tool body by means of an additional element. In the simplest case, the additional element can be provided by a fastening screw, which fixes the retaining insert to the tool body. The retaining insert, thus attached to the tool body, secures the deburring element radially outwards, so that it remains in the receiving area.

[0029] In an advantageous embodiment, the holding insert has a guide surface for guiding the deburring element along the axis of movement. Such a guide surface counteracts tilting of the deburring element in its receiving area.

[0030] It is further preferred if the holding insert has an anti-rotation surface to prevent the deburring element from rotating around the axis of movement. This ensures that the orientation of a deburring edge of the deburring element relative to the tool body is maintained, regardless of any engagement with the workpiece material. The anti-rotation surface may also act as an additional guide surface for guiding the deburring tool along the axis of movement.

[0031] It is particularly preferred that the deburring element is held with play on the retaining insert, preferably wherein the play is between 0.01 mm and 0.06 mm, and more specifically wherein the play is between 0.02 mm and 0.05 mm. Such play exists, for example, between the guide surface of the retaining insert and a cylindrical or semi-cylindrical outer surface of the deburring element and / or between the anti-rotation surface and another, for example, flat surface of the deburring element.

[0032] The aforementioned clearance between the deburring element and the retaining insert refers to the total range of motion between the deburring element and the retaining insert in a plane perpendicular to the axis of movement of the deburring element. This allows for a very small gap to be maintained between the deburring element and the retaining insert. This gap is small enough to maintain the fluid pressure acting on the deburring element, but also large enough to allow minimal fluid leakage through the gap towards the deburring edge of the deburring element. This is particularly advantageous when using a minimum quantity lubrication fluid (e.g., compressed air with oil mist).

[0033] According to the invention, it is possible for the rotary tool to be a deburring tool designed exclusively for deburring and / or for producing a chamfer on a workpiece.

[0034] However, it is possible that the rotary tool has additional functions. In particular, it is possible that the rotary tool has at least one cutting edge provided separately from the deburring element and is a drilling and deburring tool. In this case, a fluid supplied in the fluid channel of the rotary tool can be used not only to cool and / or lubricate the deburring edge of the deburring element, but also simultaneously to cool and / or lubricate the at least one cutting edge. The cutting edge can be provided as an integral part of the tool body or by a cutting insert that is detachably connected to the tool body. A wide variety of cutting inserts can be used, for example, indexable inserts.

[0035] Further features and advantages of the invention are the subject of the following description of preferred embodiments.

[0036] The drawing shows:

[0037] Fig. 1 a perspective view of a design form of a rotary tool;

[0038] Fig. 2 shows a perspective view of an assembly of the rotary tool in enlarged representation, the assembly comprising a deburring element, a holding insert and an additional element;

[0039] Fig. 3 shows a perspective view of the deburring element;

[0040] Fig. 4 shows a partial section of a front end of the rotary tool;

[0041] Figs. 5a to 5g

[0042] Sectional views of successive steps for deburring a workpiece bore and producing a chamfer; and Fig. 6 a perspective view of another embodiment of a rotary tool in the form of a drilling deburring tool.

[0043] In the drawing, a rotary tool is designated as a whole by the reference numeral 10. The rotary tool 10 has a tool body 12 that extends along a central axis of rotation 14 between a (rear) driven end 16 and a front end 18.

[0044] A fluid channel 20 is arranged in the tool body 12, extending parallel to the axis of rotation 14 between the driven end 16 and the front end 18. The fluid channel 20 is supplied with fluid from the driven end 16; the fluid exits for cooling and / or lubrication at at least one fluid outlet 22, 24. For example, a fluid outlet 22 is provided, which is arranged on an end face 26 of the front end 18 of the tool body 12.

[0045] Additionally or alternatively, a fluid outlet 24 is provided, which is arranged on a circumferential surface 100 of the tool body 12 and which is connected to the fluid channel 20 via an additional channel 28, see Figure 4.

[0046] The rotary tool 10 has a deburring element 30 which is movable along an axis of movement 32 radial to the central axis of rotation 14. The deburring element 30 can assume an inner position, in which it is arranged further inwards in the radial direction (see Figure 5d). The deburring element 30 can also assume an outer position, in which it is arranged further outwards in the radial direction (see Figure 5a).

[0047] The deburring element 30 extends along a deburring element axis 34, which, in the installed state of the deburring element 30, runs collinearly to the axis of movement 32. The deburring element 30 extends along the deburring element axis 34 between a rear end 36 and a front end 38.

[0048] At the front end 38, a deburring edge 40, preferably arcuate, is arranged, which defines a deburring plane 42. The deburring plane 42 is preferably oriented parallel to the axis of rotation 14. The deburring plane 42 forms a boundary of an end-face material section 44 of the deburring element 30. The material section 44 has an end face 43, which adjoins the deburring plane 42 and is oriented perpendicular to the deburring element axis 34.

[0049] The material section 44 is held on a main section 46 of the deburring element 30.

[0050] The main section 46 has an outer surface 48 that is at least partially cylindrical. The main section 46 also has a flat surface 50 extending parallel to the deburring element axis 34, which is bounded in the rear direction by a securing surface 52.

[0051] At its rear end 36, the deburring element 30 has a circular end face which forms an additional force-bearing surface 54. The additional force-bearing surface 54 is arranged on a cylindrical bearing section 56 which is connected to the main section 46 of the deburring element 30.

[0052] The diameter of the bearing section 56 is smaller than the diameter of the main section 46, so that an annular preload force absorption surface 58 is provided in the transition between the bearing section 56 and the main section 46.

[0053] To hold the deburring element 30 on the tool body 12, the rotary tool 10 has a holding insert 60, which in turn is detachably connected to the tool body 12 by an additional element 62, in particular by a fastening screw.

[0054] The holding insert 60 has a through-opening 64 in which the deburring element 30 is guided along its axis of movement 32. The through-opening 64 is bounded by a guide surface 66 that is at least partially hollow and by a preferably flat anti-rotation surface 68.

[0055] The guide surface 66 is larger than the outer surface 48 of the deburring element 30 and has clearance. The anti-rotation surface 68 is arranged with clearance to the flat surface 50 of the deburring element 30.

[0056] The securing surface 52 of the deburring element 30 lies - in the outer position of the deburring element 30 - against a rear side 70 of the holding insert 60.

[0057] The rotary tool 10 comprises a mechanical spring 72, which is designed in particular as a compression spring. The mechanical spring 72 extends between a supporting end 74 and a pressing end 76 along a spring axis 78, which runs parallel, preferably collinear, to the axis of movement 32 of the deburring element 30.

[0058] The pressing end 76 applies a preload force to the annular preload force absorption surface 58, acting radially outwards with respect to the axis of rotation 14.

[0059] Starting from its circumferential surface 100, the tool body 12 has a pocket-shaped recess 80 for receiving the holding insert 60, compare Figure 4 (holding insert 60 not shown there).

[0060] Radially inwards, a receiving area 82 for receiving the deburring element 30 adjoins the recess 80. The receiving area 82 is fluidly connected to the fluid channel 20.

[0061] On a side of the fluid channel 20 facing away from the receiving area 82, a local extension 84 of the fluid channel 20 is provided. The local extension 84 forms a counter bearing 86 for supporting the supporting end 74 of the mechanical spring 72.

[0062] The mechanical spring 72 passes through the fluid channel 20, with the spring axis 78 preferably perpendicular to the

[0063] The longitudinal extent of the fluid channel 20 is arranged.

[0064] Preferably, the spring axis 78 intersects with the axis of rotation 14, which simultaneously corresponds to the central axis of the fluid channel 20. The rotary tool 10 shown in Figures 1 to 4 is a deburring tool, meaning it has only a deburring function.

[0065] However, it is possible that the rotary tool 10 is a drilling and deburring tool which has at least one cutting edge 88 provided separately by the deburring element 30, compare Figure 6. The at least one cutting edge 88 can be provided by the tool body 12 or by a cutting insert 90, in particular by an interchangeable cutting insert with two cutting edges 88.

[0066] The drilling and deburring tool can also have fluid outlets known per se, for example at least one fluid outlet 22a, 22b in the area of ​​an end face at the front end 18 of the rotary tool 10 and / or a fluid outlet 24 arranged on the circumferential surface of the tool body 12.

[0067] The following describes the function of the rotary tool 10 using the example of a rotary tool 10 designed as a deburring tool, corresponding to the rotary tool 10 shown in Figures 1 to 4. This functional description can be transferred to a drilling and deburring tool as shown in Figure 6 (with the exception that a drilling and deburring tool also produces a bore).

[0068] Figure 5a shows a workpiece 90 with a bore 92 extending along an axis 94 between a first end 96 and a second end 98. The rotary tool 10 is initially in a starting position, disengaged from the bore 92. Due to the preload force of the mechanical spring 72, the deburring element 30 assumes an outer position in which the deburring edge 40 of the deburring element 30 projects radially beyond the circumferential surface 100 of the tool body 12. The deburring element 30 assumes this outer position regardless of whether a fluid is present in the fluid channel 20 and regardless of whether such a fluid is pressurized. In this way, the deburring element 30 assumes a defined position along its axis of movement 32 and is thus preloaded in the outer position.

[0069] Starting from the initial state described above, the rotary tool 10 is inserted with its front end 18 into the first end 96 of the bore 92 and is driven and rotated around the axis of rotation 14.

[0070] Figures 5b and 5c show a state in which the deburring edge 40 comes into contact with a workpiece edge 102 of the first end 96 of the bore 92 to be deburred. By applying radial outward pressure to the deburring element 30, the deburring edge 40 is pressed against the workpiece edge 102, so that the workpiece edge 102 is deburred and a chamfer 104 is preferably produced, see Figure 5d.

[0071] During the deburring of the workpiece edge 102 and, if applicable, during the production of the chamfer 104, it is possible to apply an additional force to the deburring element 30, which depends on the pressure of a fluid located in the fluid channel 20. This pressure acts on the additional force-bearing surface 54 (and also on the preload force-bearing surface 58), so that the deburring element 30 is not only forced radially outwards by the mechanical spring 72, but also by an additional hydraulic force. It is possible to vary the fluid pressure within the fluid channel 20, so that during the deburring of the workpiece edge 102 and, if applicable, during the production of the chamfer 104, the deburring edge 40 is subjected to different total forces. In this way, the chamfer width and shape can be influenced.

[0072] When the deburring element 30 has left the area of ​​the workpiece edge 102 and, if applicable, the chamfer 104, and plunges deeper into the bore 92 of the workpiece 90, the deburring element 30 is forced into its inner position, in which the end face 43 (compare Figures 2 and 3) slides along the wall of the bore 92 without cutting material (compare Figure 5d). In this state, the deburring edge 40 is located at the level of the circumferential surface 100.

[0073] Starting from the state according to Figure 5d, it is possible to move the rotary tool 10 further towards the second end 98, so that the deburring element 30 is again freed outside the bore 92 and adjacent to the second end 98 and is forced back into its outer position, either (only) by the action of the mechanical spring 72 or also supported by fluid pressure that is present in the fluid channel 20 (compare Figure 5e).

[0074] The following description preferably refers to a (still) rotating rotary tool 10: Starting from a state according to Figure 5e, the rotary tool 10 is moved again towards the workpiece 90, so that the deburring edge 40 comes into contact with a workpiece edge 106 to be deburred at the second end 98 of the bore 92, compare Figure 5f. If necessary, a chamfer 108 can be produced in the area of ​​the workpiece edge 106, compare Figure 5g. To complete the machining of the bore 92, the rotary tool 10 exits again at the first end 96, with the deburring element 30 sliding along the chamfer 104 with the deburring edge 40 and finally returning to its outer position.

Claims

Patent claims 1. A rotary tool (10) extending with a tool body (12) along a central axis of rotation (14) between a driven end (16) and a front end (18), with a receiving area (82) for receiving a deburring element (30) which is movable along a radial axis of movement (32) between an inner position and an outer position with respect to the axis of rotation (14), with a fluid channel (20) which is fluidly connected to the receiving area (82) for applying fluid pressure to the deburring element (30), characterized in that the rotary tool (10) has a mechanical spring (72) which generates a preload force and pushes the deburring element (30) radially outwards into the outer position and preloads the deburring element (30) in the outer position, wherein, depending on a fluid pressure applied in the fluid channel (20), the deburring element (30) can be subjected to an additional force acting radially outwards or is subject to charges.

2. Rotary tool (10) according to claim 1, characterized in that the mechanical spring (72) is a compression spring.

3. Rotary tool (10) according to one of the preceding claims, characterized in that the mechanical spring (72) penetrates the fluid channel (20), in particular transversely to a longitudinal extent of the fluid channel (20).

4. Rotary tool (10) according to one of the preceding claims, characterized in that the mechanical spring (72) is supported with a supporting end (74) on a counter bearing (86) of the tool body (12) and applies the preload force to a preload force receiving surface (58) of the deburring element (30) with a pressing end (76).

5. Rotary tool (10) according to claim 4, characterized in that the counter bearing (86) is provided by a local extension (84) of the fluid channel (20).

6. Rotary tool (10) according to claim 4 or 5, characterized in that the preload force receiving surface (58) is annular.

7. Rotary tool (10) according to one of the preceding claims, characterized in that the deburring element (30) has an additional force absorption surface (54) that can be subjected to or is subjected to fluid pressure.

8. Rotary tool (10) according to claim 7 with reference to one of claims 4 to 6, characterized in that the preload force receiving surface (58) and the additional force receiving surface (54) are arranged concentrically to each other with respect to the axis of movement (32).

9. Rotary tool (10) according to claim 7 or 8, each with reference to one of claims 4 to 6, characterized in that the preload force absorption surface (58) and the additional force absorption surface (54) are arranged along the The axis of movement (32) is arranged offset from each other.

10. Rotary tool (10) according to one of the preceding claims, characterized in that the fluid pressure is provided by compressed air, preferably by compressed air containing oil mist.

11. Rotary tool (10) according to one of the preceding claims, characterized in that the rotary tool (10) has a holding insert (60) for holding the deburring element (30) on the tool body (12), wherein the holding insert (60) is detachably connected to the tool body (12) by means of an additional element (62).

12. Rotary tool (10) according to claim 11, characterized in that the holding insert (60) has a guide surface (66) for guiding the deburring element (30) along the axis of movement (32).

13. Rotary tool (10) according to claim 11 or 12, characterized in that the holding insert (60) has an anti-rotation surface (68) for preventing the deburring element (30) from rotating about the axis of movement (32).

14. Rotary tool (10) according to one of claims 11 to 13, characterized in that the deburring element (30) is held with play on the holding insert (60), preferably wherein the play is between 0.01 mm and 0.06 mm, in particular wherein the play is between 0.02 mm and 0.05 mm.

15. Rotary tool (10) according to one of the preceding claims, characterized in that the rotary tool (10) is a deburring tool.

16. Rotary tool (10) according to any one of claims 1 to 14, characterized in that the rotary tool (10) has at least one cutting edge (88) provided separately from the deburring element (30) and is a drilling and deburring tool.

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