Clamping system and base, collet chuck and rotary tool therefor and method for mounting the rotary tool in the clamping system
09878376 · 2018-01-30
Assignee
Inventors
Cpc classification
B23B2231/2032
PERFORMING OPERATIONS; TRANSPORTING
Y10T29/49826
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B23B31/008
PERFORMING OPERATIONS; TRANSPORTING
Y10T279/17923
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B23B2260/026
PERFORMING OPERATIONS; TRANSPORTING
Y10T409/30952
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B23B2231/2024
PERFORMING OPERATIONS; TRANSPORTING
Y10T279/17418
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B23B2231/2091
PERFORMING OPERATIONS; TRANSPORTING
International classification
B23B31/20
PERFORMING OPERATIONS; TRANSPORTING
B23B31/117
PERFORMING OPERATIONS; TRANSPORTING
B23B31/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The invention provides a clamping system (1) for a rotary tool (70), for example a milling cutter or drill. The clamping system (1) includes a base element (10), a collet (30) and a clamping nut (50), said clamping nut (50) friction-locking the rotary tool (70) within the base element (10) with the collet (30). In order to avoid a relative rotation of the base element (10) and the collet (30), the clamping system (1) has a form locking anti-twist protection which blocks a rotation of the collet (30) relative to the base element (10).
Claims
1. A clamping system (1) for rotating tool (70) with a shaft (74), comprising: a. a base element (10), comprising a chuck for turning, milling or other rotating machines and similar with a receiving bore hole (12); b. a collet (30) with a tool bore hole (32) for the rotating tool (70), wherein the collet (30) is removably arranged in the receiving bore hole (12) of the base element (10) and is preloadable with friction locking relative to the base element (10) for providing rotational fixation wherein a clamping nut (50) axially forces the collet (30) into the receiving bore hole (12) of the base element (10); and c. a first rotation safety which blocks a rotation of the collet (30) relative to the base element (10) wherein the first rotation safety is provided by at least two catch elements (40) provided on the collet (30) in a distance to a longitudinal axis (R), wherein the catch elements engage recesses (20) on the base element (10) that are shaped complementary to the catch elements (40) in order to form a form locking connection and wherein the catch elements (40) are advantageously configured as a plug in components in form of engagement lugs that engage recesses (20) that are open in the radially inward direction so that a radial inside of the engagement lugs is configured for contacting the shaft (74) of the rotating tool (70).
2. The clamping system (1) according to claim 1, further comprising: three catch elements (40) arranged symmetrically about the longitudinal axis R of the receiving bore hole (12).
3. The clamping system (1) according to claim 2, wherein the collet (30) includes the catch elements (40) at a face oriented towards the base element (10) that extend parallel to the longitudinal axis R, wherein the catch elements engage correspondingly shaped recesses (20) in the base element (10).
4. A collet for a clamping system according to claim 1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The preferred embodiments of the present invention are now described with reference to the accompanying drawing figures, wherein:
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DETAILED SPECIFICATION
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(38) In order to attach the rotating tool 70 in the clamping system 1, the collet 30 with the rotating toll 70 is axially pressed into the receiving bore hole 12 of the base element through a clamping device. Advantageously a clamping nut 50 is used as an axial clamping device wherein the clamping nut is threaded through an inner thread 52 at the clamping nut 50 onto a thread 16 on the base element 10 at a tool side end of the base element 10. While the clamping nut 50 is threaded onto the base element 10 the clamping nut 50 forces the collet 30 into the receiving bore hole 12 so that a friction locking connection between the base element 10, the collet 30 and the rotating tool 70 is established. Also other devices can be used as collet clamping devices as they are described for example in DE 157 29 249 C2 and DE 44 05 242 A1.
(39) It is furthermore preferred according to the invention to use a collet 30 in combination with the base element 10 wherein the collet can be pressed into the receiving bore hole 12 of the base element 10 without using a clamping nut 50. Collets 30 of this type are designated in the subsequent description as press collets in order to emphasize the aspect of the lacking clamping nut. Press collets of this type are shrunk for example into the receiving bore hole 12 of the base element 10 in that the base element has been inductive heated before. Such attachments of press collets in the base element 10 without using a clamping nut 50 are generally known in the art. With respect to the advantageous press collet according to the invention it is being emphasized that these press collets have the same configurative properties as the collet described in the application documents as long as the configurative features of the collet 30 do not relate to an interaction with the clamping nut 50. Therefore the press collet is configured with the same configurative association with the base element 10, the rotating tool 70 and a reduction sleeve 60 as it is the case for the collet 30 according to the different embodiments according to the invention.
(40) The collet 30 preferably has a shape that advantageously tapers in a conical manner in the direction of the base element 10, wherein the tapering shape is formed by a radially outer enveloping surface 34. The enveloping surface 34 is supported at an inner enveloping surface 18 of the receiving bore hole 12 of the base element 10, wherein the receiving bore hole 12 is configured complementary to the outer shape of the collet 30. Advantageously the conical shape of the receiving bore hole 12 and of the radially outer enveloping surface 34 has an inclination angle of 8 to 2, even more preferably less than 3 or between 2 and 2.5 with reference to the rotation axis or longitudinal axis R. These angles of the conical shape are therefore preferred because it is only possible in this angular range that the maximum surface that is available for the clamping effect between the collet and the base element can actually be implemented for the clamping effect. Besides the conical shape of the collet 30 and the receiving bore hole 12 of the base element 10 additional cylindrical sections or other shapes are also conceivable at the collet 30 in order to support a reliable arrangement of the collet 30 in the base element 10.
(41) According to a preferred configurative embodiment of the present invention the collet 30 tapers in a direction of the base element 10 in a polyhedral (not illustrated) or substantially polyhedral shape. The radially outer enveloping surface 34 is therefore made from plural substantially polyhedral surfaces arranged about the longitudinal axis of the collet 30. Preferably these substantially polyhedral surfaces are cambered and connected with one another through rounded edges 35. A respective embodiment of collets 30 of this type is illustrated in
(42) Thus, the substantially polyhedral shape of the clamping nut 30 and the receiving bore hole 12 of the base element 10 form the first rotation safety.
(43) In analogy to the substantially polyhedral shape each substantially polyhedral shape of the components of the clamping system 1 can also be configured as a polyhedron.
(44) These substantially polyhedral surfaces of the radially outer enveloping surface 34 are supported at the substantially polyhedral inner enveloping surface 18 of the receiving bore hole 12 of the base element 10 that is configured complementary to the radially outer enveloping surface 34. The inner enveloping surface 18 accordingly has substantially polyhedral edges 19 which cooperate with the substantially polyhedral edges 35 of the collet 30. Thus, also according to this configurative alternative the receiving bore hole 12 is configured complementary to the outer shape of the collet 30. Furthermore the same rules apply for the angular arrangement of the substantially polyhedral surfaces as described supra in conjunction with the conical shape of the collet. Using the collet 30 in a substantially polyhedral shape implements a form locking connection between the collet 30 and the base element 10 after inserting the collet 30 in the receiving bore hole 12 of the base element 10. This form locking connection provides a rotation safety of the collet 30 and of the base element 10 relative to one another at least about the longitudinal axis of the collet 30. In case the base element 10 has a centrally arranged receiving bore hole the substantially polyhedral shape of the collet 30 within the receiving bore hole 12 implements a rotation safety about the longitudinal axis and rotation axis R of the clamping system 1.
(45) Based on the advantageous substantially polyhedral or polyhedral shape of the collet 30 which can also be generalized as a non circular shape, the collet has a cross section that is shaped as a triangle, a pentagon or a star in order to only recite a few selected embodiments. Based on the substantially polyhedral or polyhedral shape of the collet the catch elements 40 described infra in more detail which engage the provided recesses 20 can be omitted since based on the shape of the collet 30 a sufficient rotation safety between the base element 10 and the collet 30 is provided.
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(48) Another preferred embodiment of the clamping system 1 is illustrated in
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(50) Furthermore the collet 30 includes plural elongated slots 36 that are distributed in circumferential direction and essentially extend in axial direction, wherein the slots 36 at least partially penetrate the collet 30 in radial direction and are respectively provided at least in an axial section of the collet 30. The number of slots 36 and their width can be sized so that the clamping portion of the collet 30 is limited to a particular range. This way concentricity of the clamping system can be increased since among other things tilting errors of the collet 30 within the base element 10 are reduced. By the same token it is preferred in the present clamping system 1 to use the collet 30 without slots 36.
(51) In order to prevent or block a rotation of the collet 30 in the base element 10 relative to the base element 10 through the clamping nut 50 as an alternative to the rotation safety described supra the clamping system 1 according to the invention includes another rotation safety. This rotation safety is implemented through form locking cooperation of configurative elements at the base element 10 and the collet 30. Form locking elements that interact in this manner are advantageously configured at radially contacting sides like for example the radially outer enveloping surface 34 and the inner enveloping surface 18 of the base element 10. It is furthermore preferred to provide form locking elements at opposite faces of the base element 10 and collet 30 which are arranged perpendicular to the rotation axis of the longitudinal axis R of the elements of the clamping system 1. In this case the form locking elements are configured substantially parallel to the rotation axis R.
(52) Further preferably the rotation safety between base element 10 and collet 30 is implemented through at least one axially extending catch element 40 which engages a complementary recess 20 at the base element 10. Since the recess 20 for the engaging catch elements 40 forms an undercut in rotation direction about the rotation axis R a rotation of base element 10 and collet 30 relative to one another is locked and blocked.
(53) While three catch elements 40 and three recesses 20 shaped corresponding thereto are advantageously provided the number of catch elements 40 and recesses 20 is variable.
(54) With reference to the circumference of base element 10 and collet 30 and the distance to the rotation axis R the catch elements 40 and the recesses 20 are symmetrically and/or evenly arranged about the longitudinal axis R of the collet 30 in order to prevent for example an imbalance of the clamping system 1. According to the preferred embodiment of the clamping system 1 illustrated in
(55) In a kinematic reversal of the described form locking rotation safety between the base element 10 and the collet 30 it is also preferred to provide the catch elements 40 at the base element 10 and to provide the recess 20 at the collet 30. In the same way a mixed arrangement of the drive elements 40 and the recesses 20 at the base element and the collet 30 is conceivable. As another alternative of the form locking rotation safety an engaging teething at radially and/or axially opposite sides of base element 10 and collet 30 is implementable. For this purpose the enveloping surfaces 18 and 34 and the surfaces 22 and 44 of the base element 10 and the collet 30 are suitable. Advantageously the catch elements 40 and the associated recesses 20 are arranged symmetrically and evenly distributed about the rotation axis R. This additionally achieves a high level of concentricity and balancing when implementing the present invention which is not achievable in the prior art e.g. with conventional roller chucks. This concentricity and balance is also achievable with the same configurative embodiments for press collets without clamping nut.
(56) Alternatively and/or as a supplement to the rotation safety described supra a rotation safety is provided through the cooperation of the clamping nut 50 with the collet 30. The clamping nut 50 is threaded through the thread 52 onto the outer thread 16 of the base element 10 in order to clamp the collet 30 within the receiving bore hole 12 of the base element 10 in this manner. After the collet 30 has been clamped within the base element 10 through the clamping nut 50 a form locking connection between the clamping nut 50 and the collet 30 is established. This form locking connection can be implemented for example through interlocking or blocking with a pin. Since the clamping nut 50 is attached through the threads 52, 16 at the base element 10 the form locking connection between the clamping nut 50 and the collet 30 provides a rotation safety between the collet 30 and the base element 10.
(57) During the installation of the rotating tool 70 in the clamping system 1 the collet 30 is initially arranged in the receiving bore hole 12 of the base element 10. Thus, the catch elements 40 engage the provided recess 20 and provide the rotation safety discussed supra without additional installation complexity. Subsequently the shaft 74 of the rotating tool 70 is inserted into the tool receiving bore hole 32 and the collet 30 is clamped with the clamping nut 50 or with another clamping method for press collets. It is also preferred to insert the collet 30 or the press collet with already installed rotating tools 70 into the base element 10 and then clamp it in the base element 10 through the clamping nut 50 or respective clamping methods. Preferably the clamping nut 50 illustrated in
(58) According to
(59) According to another preferred embodiment of the present invention the clamping system 1 includes a rotation safety which blocks a rotation to the rotating tool 70 relative to the collet 30. For this purpose the tool receiving bore hole 32 of the collet 30 includes a non circular substantially polyhedral or polyhedral radial contour as illustrated in
(60) Complementary to the substantially polyhedral inner contour of the collet 30 of
(61) The substantially polyhedral shapes described supra are advantageously also configured polyhedral or generally non circular.
(62) According to another preferred embodiment according to the present invention the collet 30 includes a pull out safety for a rotating tool 70 for the collet 30. Form locking pull out safeties are described in EP 2 004 351 B1 which are referred to regarding a detailed description of the configurative properties of pull out safeties of this type.
(63) In order to implement the pull out safety at least one recess or pass through opening 46 is configured at the radially inner enveloping surface 38. A catch member 80 is fitted in the at least one recess or pass through opening 46, preferably a type of slider (c.f.
(64) The catch member is configured to that it protrudes at least partially into the centric tool receiving bore hole 32 of the collet 30. After inserting the rotating tool 70 into the collet 30 the catch member 80 engages at least one locking groove at the shaft 74 of the rotating tool 70. This way a form locking connection between the locking groove 72 and the engaging catch member 80 is provided. The at least one locking groove 72 is preferably arranged like a thread at the cylindrical tool shaft 74 starting at a face of the cylindrical shaft 74 and along the enveloping surface of the cylindrical shaft 74. The locking groove 72 arranged on the enveloping surface of the cylinder shaft 74 of the rotating tool 70 have a left pitch for left hand rotating tools 70 and a right pitch for right hand rotating tools 70.
(65) Thus the at least one locking groove 72 can also be axially configured or with an axial partial component and thus entirely or partially parallel to the rotation axis R wherein the locking groove 72 still operates as a rotation safety for the tool 70 within the clamping system 1. In this context the locking grooves 72 at the tool shaft 74 are configured screw shaped, helical, curved or as a bayonet groove and can thus also include axial and/or straight sections.
(66) The embodiment illustrated in
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(68) With respect to the catch members 80 it is additionally advantageously to arrange these in the recesses or pass through opening 46 in a replaceable and thus retrofitable manner.
(69) Furthermore
(70) It is feasible that the tool shaft 74 of the rotating tool 70 to be inserted into the tool receiving bore hole 32 is configured thin enough so that it cannot be clamped in the tool receiving bore hole 32. In order to still be able to use the rotating tool 70 a reducer sleeve 60 is inserted as a compensation and intermediary element between the tool shaft 74 and the collet 30. An exemplary embodiment of a clamping system with the reducer sleeve 60 is illustrated in
(71) The clamping system 1 of
(72) The present invention furthermore provides a clamping system 3 for rotating tools 70 as illustrated according to preferred embodiments in
(73) When using friction clamping systems 3 according to the prior art it can occur that the rotating tool is rotated relative to the base element 10 through a high torque that occurs during chipping. In order to block this relative rotation between base element 110 and rotating tool 70 the receiving bore hole 112 of the base element 110 has a non circular outer contour. An outer shape of the tool shaft 74 of the rotating tool 70 is in turn adapted it to the cross sectional shape of the receiving bore hole 112 so that the rotating tool 70 after insertion into the receiving bore hole 112 of the base element 110 forms a form locking connection with the base element 110. This means that a relative rotation between the base element 110 and the rotating tool 70 is blocked.
(74) According to a preferred embodiment of this clamping system 3 according to the invention without collet as illustrated in
(75) Based on the complementary shape of tool shaft 74 and receiving bore hole 112 a rotation safety is provided which blocks in addition to the friction locking or form locking connection between the base element 110 and the tool shaft 74 of the rotating tool 70 a relative rotation of the tool shaft 74 within the base element 110 about its longitudinal axis and/or the longitudinal axis of the rotating tool 70. Thus also this rotation safety supports stability and firm connection of the clamping system 3 so that for example integrity of the clamping system 3 is provided during heavy duty chipping operations. Preferably the receiving bore hole 112 in the base element 110 is arranged concentric with the rotation axis or longitudinal axis R of the base element. However there are also other applications for the invention in which the receiving bore hole 112 is eccentrically provided in the base element 110.
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(77) In order to further configure the tool shaft 74 and the receiving bore hole 112 of the base element 110 reference is made to the description of the clamping system 1 described supra which applies equally to the clamping system 3.
(78) With reference to
(79) In order to install the clamping system 3 the rotating tool 70 is directly inserted into the receiving bore hole 112 of the base element 110 and clamped or the rotating tool 70 is used in combination with the reducer sleeve 160 in the receiving bore hole 112 and then clamped in the same manner as the installation of the clamping system 1 is performed. Through inserting the rotating tool 70 with or without reducer sleeve in the receiving bore hole 112 of the base element 110 the rotation safety between rotating tool 70 and base element 110 is automatically implemented since the surfaces of rotating tool 70, reducer sleeve 160 and base element 110 that are configured complementary to one another are supported at one another. The same applies for the installation method of the clamping system according to
REFERENCE NUMERALS AND DESIGNATIONS
(80) 1 clamping system 10; 110 base element 12; 112 receiving bore hole 14 tool side face 16 thread 18; 118 inner enveloping surface 19; 119 substantially polyhedral or polyhedral edge 20 recess 22 surfaces 30 collet 32 tool receiving bore hole 34 radially outer enveloping surface 35 substantially polyhedral or polyhedral edge 36 axial slots 38 radially inner enveloping surface 39 substantially polyhedral or polyhedral edge 40 catch element, engagement lug 42 radially inner profile 44 profile surface 46 recess or pass through opening 50 clamping nut 52 inner thread 54 thread start of inner thread 56 contact end 58 safety distance 60; 160 reducer sleeve 62; 163 radially outer sleeve shape 64; 164 edges of substantially polyhedral or polyhedral radially outer sleeve shape 66; 166 radially inner sleeve shape 68; 168 edges of polyhedral or substantially polyhedral radially inner sleeve shape 70 rotating tool 72 locking groove 74 tool shaft 75 substantially polyhedral or polyhedral edge 80 catch member, slider 84 base plate 90 support element