Countersinking tool with tool centering controlled by pressure device

Abstract

The invention relates to a pressure device-controlled countersinking tool (1), which has one or more cutting tools (7) arranged in a rotatably driven base body (2), the tools being operable in their pivoting position by means of a feed pressure device (13), wherein at least one tool (7) is actuated via at least one piston-cylinder unit (24, 25) actuated by the pressure device (13), wherein the at least one tool (7) is pivotally mounted on a bearing pin (9) configured as a pivot axis (9a) and can be pivoted out of a tool cavity (5) arranged in a tool housing (3), wherein a centering device (21, 23; 42, 43) is arranged between the tool (7) and a tool window (6) of the base body (2) at a radial distance (44, 45, 46) from the pivot axis (9a) and in the pivoting region of the at least one tool (7).

Description

Technical Field

[0001] The subject matter of the invention is a countersinking tool controlled by a pressure device according to the preamble of claim 1 . Background Art

[0002] Such a countersinking tool is known, for example, from DE 10 2009 012 996 A1 which dates back to the same applicant.

[0003] In accordance with the description therein according to paragraphs 0001 to 0005, the invention relates to a countersinking tool defined therein, which is designed both as a reverse countersinking tool and as a forward countersinking tool.

[0004] The invention further relates to a countersinking tool having one or two pivotable tools, wherein each tool can be actuated by its own piston-cylinder unit or both tools can be actuated together by a single piston-cylinder unit.

[0005] In the case of an arrangement of two knives, it is also preferred that one knife can be pivoted out at the front of a knife window provided in the knife housing, while the other knife can be pivoted out from behind the knife window using a complementary movement sequence.

[0006] However, for the sake of simplicity, the following description assumes that there is only one tool to which the piston-cylinder unit actuated by the pressure device is assigned, although the invention is not limited to the arrangement of a single tool. Regarding the operation of such a pressure device-controlled countersinking tool, reference is generally made to the subject matter of DE 10 2009 012 996 A1.

[0007] EP 2 589 451 B1, which dates back to the same applicant, describes a further pressure-means-controlled countersinking tool having a piston-cylinder unit, wherein reference is made to the disclosure of EP 2 589 451 B1 with regard to the design and the manner of operation.

[0008] However, the invention is not limited to a tool of a countersinking tool which can be pivoted out under the action of centrifugal force.

[0009] Therefore, the present invention also provides a pressure device-controlled countersinking tool, in which the pivoting-out process or the pivoting-back process or both pivoting processes are performed with any driving force.

[0010] The above-mentioned pressure device-controlled countersinking tool, which can be traced back to the same applicant, can be optimized with regard to the countersinking accuracy and the reproducibility of the countersink produced in the bore of the workpiece.

[0011] During operation of a countersinking tool according to the subject matter of DE 10 2009 012 996 A1 or EP 2 589 451 B1, it has been found that the necessary play must be present in the bearing bore for pivotally supporting at least one tool so that the (at least one) tool can be pivoted out of the tool window without problems without risking a tool bearing breakage. This results in a maximum countersinking accuracy and countersinking reproducibility of + / - 0.2 mm. Summary of the invention

[0012] The object of the present invention is therefore to develop a pressure-device-controlled countersinking tool of the type mentioned at the outset, such that the countersinking accuracy and the countersinking reproducibility are significantly improved.

[0013] In order to achieve the above object, the present invention is characterized by the technical teaching of claim 1 .

[0014] The technical teaching according to the invention firstly achieves the advantage that a countersinking accuracy of at least + / -0.1 mm can be achieved.

[0015] This is an important step forward, since, up to now, countersinking tools controlled using pressure devices could not achieve this kind of countersinking accuracy.

[0016] By installing a special radially acting tool centering device in the tool housing, the tool can be centered in a positively locking and play-free manner during the machining process. However, the necessary axial play in the tool bearing can be maintained at the same time.

[0017] This type of centering enables very high reproducibility of countersinking with very low scatter.

[0018] Due to the corresponding manufacturing precision, this centering also enables absolute countersinking accuracy, which meets the expanding requirements on the market.

[0019] The machining process generates an axial machining force on the tool, which in a first preferred embodiment presses the tool with its centering groove against a housing-side centering pin in the tool housing and centers and fixes it in a form-fitting manner along its centering axis. Here, the circular contoured contact surface of the transversely extending centering groove provided in the tool bears in a form-fitting manner against a complementary, likewise circularly extending contact surface of the housing-side centering pin and centers the tool on its centering axis on the housing-side centering pin extending in the longitudinal direction of the tool.

[0020] The centering device according to the invention thus prevents a radial movement of the tool along the centering axis.

[0021] In other words, this means that the centering device according to the invention prevents a displacement play movement of the tool in the bearing pin in the bearing opening on the basic body side.

[0022] The centering device is preferably designed such that it carries out a positive-locking centering of the tool along the centering axis in the operating state of the tool pivoted out, wherein in the pivoted-in state such centering is not necessary.

[0023] The centering device is preferably arranged at a certain distance from the bearing pin with play in the bearing opening.

[0024] In addition to the above-mentioned first preferred embodiment, there are several other embodiments for the construction of the centering device, all of which have in common that, at least in the pivoted state of at least one tool, a protrusion or recess arranged on the tool is engaged in a shape-locking manner in a recess or protrusion on the configured tool housing side.

[0025] In a first preferred embodiment of the invention, it is provided that the centering device comprises a centering groove provided on the tool at the foot, whose longitudinal extension is oriented perpendicular to the centering axis of the tool and which in the machining position engages in a positively locking manner with a centering pin on the housing side.

[0026] The foot-side centering groove is accordingly designed as a transverse groove in the foot region of the tool and interacts with a part of the housing-side centering pin by means of a positive fit.

[0027] In another embodiment of the invention, a kinematic reversal of the first exemplary embodiment can be provided, wherein a centering pin is arranged on the foot side of the tool and can engage in a laterally extending centering groove on the housing side.

[0028] In all the embodiments involved, it is particularly advantageous if the centering pin has a circular contour and the upper part of its outer circumference protrudes from its receiving opening (on the tool or on the housing) and there forms a centering surface for engaging in a centering groove (on the tool or on the housing).

[0029] To simplify the description, the following description is based on a first kinematic configuration, in which the centering pin is arranged on the housing side and is mounted in a housing-side receiving bore, and the complementary centering groove is designed as a transversely extending centering groove on the foot side of the tool.

[0030] This simplified description is given only for simplicity, and the invention is not limited to this kinematic embodiment.

[0031] In any case, it is easier from a manufacturing technology point of view to mount a centering pin on the housing side than to mount such a centering pin on the foot side of the tool.

[0032] When the centering pin is mounted on the housing side, it is preferably configured to be replaceable. Therefore, it can be pulled out from its transverse hole along its longitudinal extension direction.

[0033] The centering pin can thus have different material properties compared to the material of the tool and can also be replaced if there are signs of wear.

[0034] The centering pin can also be designed as a spring element which, in the pivoted-out state, engages in a centering groove designed as a transverse groove on the foot side of the tool.

[0035] This can be a locking eccentric connection.

[0036] In a further embodiment of the invention, the centering device comprises a centering projection which is arranged on the upper side or the foot side of the tool and which in the machining position can engage in a positively locking manner with a complementary centering groove on the housing side.

[0037] During operation, it is found that the tool and its centering groove or its centering projection are pressed against the centering pin or centering groove in the tool housing by the axial machining forces generated by the machining process, and the tool is positively centered along the centering axis and fixed in the tool housing.

[0038] It is ensured here that the main machining forces are transmitted via the contact point in the tool window into the tool housing and not via the pivot bearing comprising the bearing pin and the receiving bore.

[0039] This is why initially in countersinking tools belonging to the prior art sufficient play had to be provided in the tool bearing.

[0040] However, according to the invention it is now provided that the only remaining radially acting degree of freedom influencing the countersinking result is eliminated by the new centering device.

[0041] The chip removal, which plays a major role in the subject matter of DE 10 2009 012 996 A1, plays only a minor role in the current system, since a sufficient flushing function with cooling lubricant is provided during the machining process.

[0042] In this way it is ensured that the centering device according to the invention is free of chips.

[0043] The positive-locking and thus sealing engagement of the tool-side centering element in the associated, housing-side, complementary centering element also plays a role here, since the centering device is protected against the intrusion of chips by the positive-locking engagement.

[0044] The centering device is, so to speak, self-sealing during the machining process, since the form-fitting engagement prevents chips from penetrating into the centering device.

[0045] If chips accumulate in the centering device, they are removed when the tool is pivoted into the centering device.

[0046] If only the deburring of the bore in a back countersinking operation is described in one of the dependent claims, this is not to be understood as restrictive.

[0047] The present invention relates to all modes of operation of the countersinking tool, whether deburring is performed in a forward or backward countersinking operation.

[0048] In another preferred embodiment, it can be provided that additional, further centering devices for centering the tool along the centering axis are arranged on the side of the tool window.

[0049] It is therefore provided that not only the top-side or foot-side centering device according to the invention is arranged between at least one tool and a surface provided in the tool housing, but also further centering devices arranged perpendicular thereto are arranged in the side surfaces of the tool window.

[0050] The inventive subject matter of the present invention derives not only from the subject matter of the individual patent claims but also from the mutual combination of the individual patent claims.

[0051] All information and features disclosed in the document including the summary, and in particular the spatial configurations shown in the drawings, may be claimed as essential to the invention, provided that they are novel individually or in combination compared with the prior art. The use of the terms "essential" or "according to the invention" or "essential to the invention" is subjective and does not mean that the features named in this way must be an integral part of one or more patent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In the following, the invention is explained in more detail with reference to the accompanying drawings which show only one embodiment.

[0053] Further features and advantages of the invention which are essential to the invention emerge from the drawings and their description.

[0054] In the attached figure:

[0055] Figure 1 A cross-sectional view of a countersinking tool with radial centering of the tool, controlled by a pressure device, is shown;

[0056] Figure 2 A perspective view of the tool is shown;

[0057] Figure 3 shows a perspective view of a preferred embodiment of the knife;

[0058] Figure 4 Shown according to Figure 3 A side view of the tool showing further details;

[0059] Figure 5 Shown according to Figure 1Countersinking tool with tool retraction;

[0060] Figure 6 Shown according to Figure 1 A countersinking tool located at a countersinking position with a tool extending therefrom;

[0061] Figure 7a Shown with Figure 6 The same refers to the illustration of the detail Z of the drawing;

[0062] Figure 7b Shows Figure 7a Details of the drawings Z;

[0063] Figure 8 Shows the relative Figure 6 A first embodiment of the change; and

[0064] Fig. 9 Shows the relative Figure 6 A second alternative embodiment. DETAILED DESCRIPTION

[0065] exist Figure 1 A preferred embodiment of the countersinking tool 1 is shown, which mainly includes a cylindrical base body 2, which is driven to rotate around its longitudinal axis in the direction of arrow 20 and in the opposite direction, wherein a feed hole 14 is arranged in the upper area of ​​the base body 2, through which the pressure device 13 is pressed into the cylindrical space 25 of the base body 2 in the direction of arrow 15.

[0066] In the cylinder space 25, the piston 24 is supported movably in the direction of the longitudinal extension of the base body and, when it moves, a piston rod driving head component 29 fastened thereto via a suitable pressure element, which head component is part of a control pin 27, which is driven movably in the longitudinal hole 12 of the base body and whose pin end 30 acts on the free, pivotable end of the tool 7 pivotably supported on the supporting pin 9.

[0067] The actuation of the control pin 27 in the direction of the arrow 28 takes place against the force of a compression spring 31 , the lower end of which bears against a stop 32 on the housing side.

[0068] In this way, a return of the spring load of the control pin 27 is ensured when the pressure means action of the pressure means 13 on the piston 24 is removed.

[0069] Instead of a spring return, other return drives can also be used.

[0070] In order to limit the stroke of the piston 24 , a locking screw 33 is screwed into the base body 2 , which locking screw projects with its pin-side end into the displacement path of the piston 24 .

[0071] A cylinder space 26 is also provided in the base body 2, through which a flushing agent flow flows from the pressure means 13, which is guided downward into the tool chamber 5 via a bypass opening 17 extending in the extension of the tool housing 3. In this way, it is ensured that the tool chamber 5 is fully flushed by the pressure means 13 and that the entire tool chamber 5 remains free of chips.

[0072] Tool housing 3 is preferably detachably arranged on base shell 2 , and at least one fastening screw 4 serves to connect the two parts.

[0073] Figure 1 The tool 7 is shown pivoted out of the tool window 6 in its machining position, wherein the entire countersinking tool 1 is driven in rotation in the rotational direction 20 .

[0074] The tool 7 is pivotally supported in the supporting hole 16 (see Figure 2 ) in which the two parts 9, 16 constitute a horizontal pivot axis 9a.

[0075] During the machining process, the lateral cutting edge 8 on the tool 7 engages with a hole edge (not shown in detail) of the hole, which is deburred and / or countersunk.

[0076] In the prior art, the tool 7 pivoted out in the countersinking position still had an undesirable degree of freedom in the bearing bore 16 , which is now eliminated by the centering device according to the invention.

[0077] Undesirable degrees of freedom in Figure 7b A radial displacement 47 along a centering axis 48 in the direction of arrows 39 , 40 is shown.

[0078] According to the invention, the centering device in the preferred first embodiment comprises a centering groove 21 introduced on the underside of the tool 7 at the foot end, which is designed as a transverse groove and whose longitudinal extension is parallel to the longitudinal extension of the bearing pin and the bearing opening 16 .

[0079] In order to eliminate the play in the directions of the arrows 39, 40 and to ensure centering along the centering axis 48, it is provided that the receiving hole 22 introduced in the bottom of the tool window 6 in the illustrated machining position (see Figure 7b ) accommodates a centering pin 23 of preferably circular contour, which protrudes from the receiving opening 22 only with its upper outer periphery in order to ensure centering on the complementary contact surfaces 35, 36 of the centering groove 21 via its peripheral centering surface.

[0080] from Figure 2 It can also be seen that the pin end 30 of the control pin 27 acts on the control surfaces 18 , 19 spaced apart from one another in order to move the tool from the extended machining position in the direction of the arrow 10 into its pivoted-in position.

[0081] From the combination Figure 7b of Figure 7a Further details may be identified.

[0082] The machining process generates an axial machining force 34 which presses the tool 7 with the centering groove 21 against the centering pin 23 in the tool housing 3 and centers and fixes it in a form-locked manner in the arrow direction 39 and the arrow direction 40, thereby eliminating radial movements 47 acting in these directions 39, 40 and defining a centering axis 48, which prevents the tool 7 from moving in the tool housing 3 in the arrow directions 39, 40.

[0083] Here, Figure 3 and 4 The tool 7 is shown with its lateral cutting edge 8 , wherein it can be seen that the preferred centering groove 21 is provided as a transverse groove at a distance 44 from the bearing opening 16 on the foot side of the tool.

[0084] The centering groove 21 has a centering angle 41 which is complementary to the outer circumference of the centering pin 23, which is mounted substantially without play but preferably replaceably in the receiving opening 22 in the tool housing 3. Only the upper outer circumference of the centering pin 23 protrudes from the receiving opening 22, so that a contact surface complementary to the outer circumference of the centering pin 23 is produced at the contact points 37, 38 on the tool side.

[0085] and Figure 6 compared to, Figure 5 Shown in accordance with Figure 5 In the pivoted-in state of the tool, the centering device is not engaged, ie the entire pivotable part of the tool 7 is accommodated in the tool cavity 5 .

[0086] Only when based Figure 6 When the tool 7 moves in the direction of the arrow 11 into its extended and radially centered machining position, the contact points 37, 38 of the tool 7 are positively engaged in accordance with Figure 7b On the upper outer periphery of the centering pin 23.

[0087] The relationship just described is Figure 7b , in which a centering axis 48 is also indicated symbolically, which eliminates the radial displacement 47 indicated by the arrows 39 , 40 and holds the tool centered and form-fittingly on the upper outer circumference of the centering pin 23 .

[0088] The centering pin 23 can be inserted into the assigned fit of the receiving opening 22 without play.

[0089] This means that it has no play in the receiving opening 22 and is fixed there.

[0090] However, in another embodiment not shown in the drawings, the centering pin 23 can also be received in the receiving hole 22 in a replaceable manner.

[0091] It can then be knocked out of the receiving opening 22 in order to be replaced with a suitable tool.

[0092] Furthermore, the material of centering pin 23 is independent of the material of tool housing 3 , which means that centering pin 23 can also be made of a hardened metal material.

[0093] It may also be composed of a metal that is softer than the material of the knife.

[0094] It may also consist of a plastic material.

[0095] In another embodiment not shown in detail in the figures, it can also be provided that the centering pin 23 is designed as a spring pin, so that its outer circumference is prestressed radially outwardly by a spring.

[0096] When the centering groove 21 arranged on the foot side of the tool 7 rests on the centering pin 23 designed as a spring pin, a positive-locking snap connection occurs between the tool-side groove and the housing-side spring pin.

[0097] When the tool is pivoted in the direction of arrow 10 to its Figure 5 When the hinge is swung into position, the snap connection is released again.

[0098] Figure 8 and Fig. 9 Two further embodiments of the centering device are shown, wherein Figure 8 It can be seen that the centering device at a distance 45 from the pivot axis 9a of the bearing pin 9 is formed by a projection 43 formed on the foot side of the tool 7, which does not have to extend over the entire width of the tool. It can also be point-shaped or composed of a plurality of centering projections 43 arranged at a distance from each other.

[0099] One or more centering projections 43 protruding from the foot side of tool 7 then engage in a form-fitting manner in an associated, complementary centering groove 42 or a centering projection recessed in the bottom surface of tool window 6 .

[0100] There are multiple options for this as well.

[0101] One or more half-open centering grooves on the foot side of tool window 6 can be arranged adjacent to one another and oriented on the same transverse line.

[0102] In another embodiment, it can be provided that centering groove 42 formed so as to be recessed in the foot side of the tool window extends over the entire width of the tool window.

[0103] The same illustration also applies to Fig. 9 The kinematic transformation of the centering recess is shown.

[0104] Using the same information given above, it can be seen there that the centering arrangement 42 , 43 is not arranged on the foot side of the tool 7 , but on the opposite side, namely at a distance 46 from the pivot axis 9 a of the bearing pin 9 .

[0105] For the construction of the components of the centering device shown here, the following applies: Figure 8 The centering devices 42, 43 in FIG.

[0106] Overall, with the arrangement of the centering devices 21 , 23 ; 42 , 43 described here, a precisely defined centering axis 48 is achieved and radial displacements 47 in the directions of the arrows 39 , 40 are effectively eliminated.

[0107] It is important that the centering device prevents the tool from moving along the centering axis 48 rather than tilting.

[0108] The tilting does not have to be taken up or eliminated by the centering device, since the tool bears against the left and right surfaces of the tool window in this direction and its degrees of freedom are therefore sufficiently limited.

[0109] Compared to conventional countersinking tools according to the prior art, the countersinking accuracy can thus be improved by a factor of ten.

[0110] Reference numerals list

[0111] 1. Countersinking tools

[0112] 2. Matrix

[0113] 3. Tool housing

[0114] 4. Fastening threaded parts

[0115] 5. Tool cavity

[0116] 6. Tool window

[0117] 7. Knives

[0118] 8. Chip cutting edge

[0119] 9. Support pin

[0120] 9a. Pivot axis

[0121] 10. Arrow direction

[0122] 11. Arrow direction

[0123] 12. Longitudinal hole

[0124] 13. Pressure devices

[0125] 14. Feed hole

[0126] 15. Arrow direction

[0127] 16.(7) Support hole

[0128] 17.Bypass hole

[0129] 18. Control Surface

[0130] 19. Control Surface

[0131] 20. Rotation direction

[0132] 21. (7) Centering groove

[0133] 22. (3) Receiving hole

[0134] 23. Centering pin

[0135] 24. Piston

[0136] 25. Tank space

[0137] 26. Tank space

[0138] 27. Control pin

[0139] 28. (27) Arrow direction

[0140] 29. (27) Head part

[0141] 30.(27) Pin end

[0142] 31.Compression spring

[0143] 32. Stopper

[0144] 33. Stop screw

[0145] 34. Axial processing force

[0146] 35. (21) contact surface

[0147] 36. (21) contact surface

[0148] 37. Snap position

[0149] 38. Snap position

[0150] 39. Arrow direction

[0151] 40. Arrow direction

[0152] 41. Centering angle

[0153] 42.(3) Centering groove

[0154] 43. (7) Centering protrusion

[0155] 44. Distance (between 9a and 21)

Claims

1. A pressure device-controlled countersinking tool, the countersinking tool having one or more cutting tools arranged in a rotatably driven base body, the tools being operable in their pivoted positions by means of a feed pressure device, wherein at least one tool is actuated via at least one piston-cylinder unit actuated by the pressure device, wherein the at least one tool is pivotably mounted on a bearing pin configured as a pivot axis and can be pivoted out of a tool window arranged in a tool housing, characterized in that A centering device is arranged at a radial distance from the pivot axis and in the pivot region of at least one tool between the tool and the tool window of the tool housing, wherein: The centering device comprises a centering groove arranged on the tool at the foot side, the longitudinal extension of which is oriented perpendicular to the centering axis of the tool and which in the machining position engages in a positively locking manner with a centering pin on the housing side; and / or The centering device comprises a centering projection which is arranged on the upper side or on the foot side of the tool and which can engage with a centering groove on the housing side in the machining position.

2. The pressure device controlled countersinking tool according to claim 1, characterized in that: The centering device secures the tool against radial movement in the direction of the arrow along the centering axis.

3. The pressure device controlled countersinking tool according to claim 1 or 2, characterized in that: The centering device secures the tool against a displacement play movement of the bearing pin in the bearing opening on the base body.

4. The pressure device controlled countersinking tool according to claim 1, characterized in that: The housing-side centering pin is of circular contour, is inserted in a housing-side receiving opening and projects with its upper part of the outer circumference out of the receiving opening and forms there a centering surface for engaging in a centering groove of the tool.

5. The pressure device controlled countersinking tool according to claim 4, characterized in that: The housing-side centering pin is replaceably accommodated in the housing-side accommodation hole.

6. The pressure device controlled countersinking tool according to claim 1, characterized in that: The tool and its centering groove or its centering projection are pressed against the centering pin or the centering groove in the tool housing by means of the axial machining forces generated by the machining process, and the tool is positively centered along the centering axis and fixed in the tool housing.

7. The pressure device controlled countersinking tool according to claim 1, characterized in that: When centering the tool, the two tool-side contact surfaces of the centering groove rest against complementary cylindrical contact surfaces of the housing-side centering pin, and in the process the tool is centered in the tool housing along the centering axis in a positively locking and play-free manner.

8. The pressure device controlled countersinking tool according to claim 1, characterized in that: In the retracted state, the tool penetrates the hole to be countersunk on the rear side of the workpiece and, in the extended state from the tool window, produces a countersunk hole in the hole on the rear side of the workpiece.

9. The pressure device controlled countersinking tool according to claim 1, characterized in that: The tool is centered in the tool window in the axial direction along the center axis of the bearing pin or the bearing opening.

10. The pressure device controlled countersinking tool according to claim 1, characterized in that: The main machining forces of the tool can be transmitted into the tool housing via the contact point of the tool on the tool window.

11. The pressure device controlled countersinking tool according to claim 1, characterized in that: The only remaining radially acting degree of freedom which influences the countersinking result is eliminated by the centering device.

12. The pressure device controlled countersinking tool according to claim 1, characterized in that: The centering pin can be replaced in the event of wear.

13. The pressure device controlled countersinking tool according to claim 1, characterized in that: Additional centering devices for centering the tool are arranged on the sides of the tool window.

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