WO2020057680A1

WO2020057680A1 - Fixing device for machine tools

Info

Publication number: WO2020057680A1
Application number: PCT/DE2019/000237
Authority: WO
Inventors: Hermann Oesterle
Original assignee: Oesterle + Partner Gbr (Vertretungsberechtigte Gesellschafter: Hermann Oesterle, Talstr. 21, 72202 Nagold, De Und Harald Oeschger, Hauptstr. 78/1, 79312 Emmendingen, De)
Priority date: 2018-09-17
Filing date: 2019-09-11
Publication date: 2020-03-26
Also published as: DE102018007414A1

Abstract

The invention relates to a fixing device for machine tools for fixing at least one tool holder (2) to a tool carrier (3), comprising a first fastening device (4) with clamping screws for fixing the tool holder (2) in a positionally accurate manner on the tool carrier (3) under the action of an alignment device (5) between a contact surface (6) of the tool holder (2) and a supporting surface (7) of the tool carrier (3), and comprising a second fastening device (8) in the manner of a quick-action clamping device (9) having at least one clamping shaft (10) protruding from the tool holder (2), wherein said clamping shaft can be guided in a receptacle (11) in the tool carrier (3) and can be locked by at least one clamping device (12) of the quick-action clamping device (9). The clamping device (12) comprises at least one clamping element (13) and an actuating element (14) for the clamping element (13). The clamping element (13) is supported on a control surface (15) which lies radially opposite the clamping shaft (10) in the receptacle (11). When the actuating element (14) is actuated, the control surface (15) moves in the circumferential direction of the clamping shaft (10). The clamping element (13) performs a movement directed radially to/from the clamping shaft (10), which brings about a fixing of the clamping shaft (10) in the receptacle (11) which can be released and locked in a form-fitting manner.

Description

Fixing device for machine tools

The invention relates to a fixing device for machine tools for fixing at least one tool holder to a tool holder, according to the preamble of claim 1. DE 10 2008 048 206 B4 describes a fixing device for machine tools for fixing at least one tool holder to a tool holder formed as a tool turret . A first fastening device formed from tensioning screws is used here for the precise fixing of the tool holder on the tool carrier. The clamping screws are arranged in bores on corner areas of a rectangular base body of the tool holder and penetrate through the bores, to which threaded bores in the corner areas of a support surface on the tool carrier are assigned. The screw heads of the clamping screws, which are accessible at the top of the rectangular base body of the tool holder, each have a hexagon socket, so that the clamping screws can be tightened by means of a tool, and a contact surface on the underside of the tool holder is thereby precisely positioned on the contact surface of the tool holder under the effect of an alignment device and is tense.

Locking devices with screw fastenings take a lot of time when changing and aligning the tool holder, which affects the economy of a machine tool.

DE 195 48 151 Al describes a tool fixing device for machine tools, with a tool holder, which has a contact surface and

has a cylinder-like clamping shank projecting from this for clamping the tool. A tool carrier in the form of a turret disk with a large number of tool stations, each of which has a support surface and a receptacle for the clamping shank, is used to clamp a respective shank in the respective receptacle. An alignment device between the contact and support surface is used to precisely position the respective tool holder on the turret disk.

The machine tools already in use and on the market therefore have different fixing devices with screw fastening systems or quick-action clamping systems. There are also many different alignment systems for exact, repeatable positioning of tool holders on tool carriers. The set-up or tool change times of such machines are sometimes disproportionately long. In addition, different tool holders are not always compatible with different tool carriers.

DE 10 2017 007 905 A1 by the applicant describes a fixing device for machine tools for fixing at least one tool holder to a tool carrier, with a first fastening device with clamping screws for precisely fixing the tool holder to the tool carrier under the effect of an alignment device between a contact surface of the tool holder and a support surface of the tool carrier.

In order to enable a combination of different tool carriers with different tool holders, a second fastening device in the form of a quick-action clamping device is provided on the fixing device, which has a clamping shaft protruding from the tool holder, which can be guided into a receptacle in the tool carrier and with at least one clamping device of the quick-clamping device can be locked. This means that an existing tool holder with a screw fastening system and a tool holder with a clamping shank and a radial or gripping

can also be used for a quick release device on the same tool carrier.

However, desires regarding the manufacture and the cost of such a fixing device remain open. Based on this prior art, the invention is therefore based on the object of specifying a fixing device for machine tools which, on the one hand, enables a combination of a wide variety of tool carriers with a wide variety of tool holders, which is simple and inexpensive to produce, and which on the other hand enables precise operation of a machine tool. ne allowed with minimal manufacturing tolerances of workpieces.

The object is achieved with a fixing device with the features of claim 1.

Characterized in that the clamping device is formed in a very compact form with at least one clamping element and an actuating element for actuating the clamping element, the clamping element being supported on an inclined surface or control surface which is radially opposite the clamping shaft in the receptacle and when the actuating element is actuated the inclined surface moves in the circumferential direction of the clamping shaft and the clamping element thereby executes a movement directed radially towards / from the clamping shaft, which causes the clamping shaft to be positively and releasably fixed in the receptacle, an inexpensive fixing device is created which enables the tool holder changing times to be minimized.

The essential components of the fixing device are arranged in the receptacle for the clamping shank itself, so that in relation to the manufacture of the fixing device essentially only the receptacle has to be redesigned and no particularly complex modifications to the

Tool holders are required, which would also significantly weaken the cross section of the tool holder.

With the fixing device according to the invention, tool holders with screw fastening systems and tool holders with quick-release devices can be used on one and the same tool carrier. The possible uses of tool holders already available to a user without a quick-action clamping system, as well as tool holders with a quick-action clamping system and clamping screws, or tool holders that can only be fixed with a quick-action clamping system, are expanded by the fixing device according to the invention.

Preferred embodiments of the invention result from the subclaims.

The clamping element preferably engages in a radial groove which is arranged around the circumference of the clamping shaft. The clamping element can be made small, so that a small space requirement, in particular in the radial direction of the clamping shaft, results for the fixing device. In a preferred exemplary embodiment, the clamping element is fixed to a fixed axis of rotation arranged in the receptacle in the tool carrier and thus enables a permanent function of the fixing device.

A control element having the inclined surfaces or control surfaces can be arranged so as to be displaceable along a control surface of the clamping element under the action of the actuating element such that the clamping element swivels into the radial groove of the clamping shaft with an arresting flank when the actuating element is actuated. This creates a radial and axial force in the clamping shank, which allows it to be centered and fixed on the mount without play. The tensioning device is thus designed in the manner of a bayonet lock, which can be operated with little wear and often.

In one embodiment of the fixing device, the axis of rotation for the clamping element is supported indirectly on a support element on the receptacle in the tool carrier. The support element, the axis of rotation and the clamping element can thus be preassembled and then inserted and fixed in the receptacle.

The support element is preferably formed as a ring, on which at least two clamping elements are located diametrically opposite one another and are fixed to the support element via respective axes of rotation. The inner diameter of the ring is selected so that the clamping shaft can be passed through with radial play. Four clamping elements are preferably arranged on the ring in a cross arrangement, each diametrically opposite one another. This results in a rotationally symmetrical arrangement of the clamping elements around the clamping shaft, which can thereby be centered and fixed well in the receptacle.

The actuating element for displacing the inclined surface relative to the tensioning element is preferably formed as a screw which engages with its thread in a toothed section of the control element and, when the screw is actuated, sets the control element in a rotary movement about a longitudinal axis of the receptacle. This causes a radial displacement of the locking flank of the clamping element to / from the radial groove of the clamping shaft. The actuating element formed as a screw is introduced in a cylindrical guide in the manner of a bore in the tool holder, the bore being guided by a face other than the support surface of the tool carrier. The bore represents a minimal cross-sectional weakening compared to other systems on the market. The screw is held axially immovable in the guide and can therefore exert tensile or compressive forces on the control element when turning.

The control element is particularly preferably formed as a ring, on the inside of which the inclined surfaces for the actuation of the tensioning elements are arranged

and on the outside of which the toothed section or a toothing extending around the entire circumference of the ring is arranged, in which the thread of the actuating element engages. Such an exemplary embodiment of the control element is particularly simple and inexpensive to manufacture.

If a toothing is chosen around the entire circumference of the control element, it can be mounted independently with respect to its rotational position in relation to the clamping shaft.

The respective support element, which is formed as a ring, and the control element preferably have the same outside and inside diameter and, in a functional position of the fixing device, lie one above the other with a respective sliding surface, so that they can be rotated relative to one another, or that the control element is opposite the support element, which is stationary, can be twisted.

Both rings are axially immovable in the receptacle with a snap ring which engages in a groove in the receptacle. This results in simple assembly and, if necessary, disassembly of the rings and clamping elements. In addition, the installation space requirement of such an arrangement is minimal.

The respective control flank and the locking flank of each clamping element are formed in the manner of circular arc sections or circular arc segments and are tapered to one another. All clamping elements are identical. The arc radius of the locking flank is adapted to the radius of the radial groove in the clamping shank. The arc radius of the control flank is adapted to the radius of the inclined surfaces in the control element.

The clamping shank itself can be cylindrical or with one or more reductions in diameter from its end facing the contact surface of the tool holder to the end facing away from the contact surface

be educated. The clamping shank can be formed in the manner of DIN 69880 and have at least one cylindrical length range. The clamping shank can also be formed as a tool shank for BMT tool carrier systems.

A multiplicity of tool holders and fixing devices can be arranged on a tool carrier.

With the fixing device according to the invention, a conversion possibility for tool holders and tool carriers with screw connections is created in order to provide them with a quick-action clamping device that is simple to manufacture and requires little modification work. The quick-action clamping device can also be referred to and understood as a bayonet hollow clamping device.

The invention will now be described in more detail with reference to exemplary embodiments and shown with the aid of the drawings. Show it:

1 shows a longitudinal section through a fixing device for machine tools;

FIG. 2 shows a cross section through the fixing device in FIG. 1 along the line II-II;

3 shows a further cross section through the fixing device in FIG. 1;

Fig. 4 is a plan view of a quick release device; Fig. 5 is a perspective view of the quick release device in Fig. 4; and

Fig. 6 is a perspective view of a tool carrier with recesses for receiving the quick release device shown in Figs. 4 and 5.

In Fig. 1, a tool holder 2 for rotating tools is shown, which is clamped with its base body with a fixing device 1 according to the invention on a tool carrier 3. The fixing device 1 has a first fastening device 4, which consists of six clamping screws, not shown, which are to be screwed into threaded bores 36 shown schematically in FIG. 6 in the tool carrier 3 and is formed from a clamping shaft 10. When fixing, a contact surface 6 on the tool holder 2 comes into precise contact with a contact surface 7 on the tool carrier 3 under the action of an alignment device 5. In addition to the first fastening device 4 formed from the clamping screws (not shown) and the threaded bores 36, the fixing device 1 according to the invention has one further, second fastening device 8, which makes it possible to use the tool holder 2 in the shortest possible time by means of a quick-release device 9 of the second fastening device 8 on the tool carrier, even without using the first fastening device 4

Set time. The quick release device 9 is shown in FIG. 1 and with its essential components in FIG. 5 in a perspective view and is also referred to in technical terms as a vertical bayonet hollow tensioner.

The clamping shank 10 used by the second fastening device 8, as shown in FIG. 1, is formed as a hollow shank and projects axially through a drive shaft 37 for the tool, not shown, on the tool holder 2. The clamping shaft 10 is part of the quick-action clamping device 9 and is screwed into the base body of the tool holder 2 with a centering seat. It protrudes vertically from its contact surface 6 in order to be able to be locked without play in a substantially cylindrical receptacle 11 in the tool carrier 3 with a clamping device 12 of the quick-clamping device 9.

For the operative connection of the clamping shaft 10 to the clamping device 12, the clamping shaft 11 has an end 35 facing away from the contact surface 6

Radial groove 16 with a further lower flank 38 which runs conically to a longitudinal axis 26 of the receptacle 11.

4 and 5, four clamping elements 13 arranged in a cross arrangement engage in the radial groove 16, the clamping elements 13 being diametrically opposed and the clamping shaft 10 or around its radial groove 16 each in a 90 ° arrangement encompassing each other to come to lie in the recording 1 1. An actuating element 14 in the manner of a screw 23 with a trapezoidal thread 24 causes during rotation a movement of the clamping elements 13 radially from / to the radial groove 16, each of which is located on a control or inclined surface 15 which the clamping shaft 10 in the Support seat 11 radially opposite, support.

In Fig. 2 u. a. in the middle of the figure in a central plan view of the receptacle 1 1 on the base of which parts of the clamping device 12, namely the clamping elements 13 positioned in a cross arrangement, are shown, each of which is pivotably attached to a fixed axis of rotation 17 arranged in the receptacle 11 in the tool carrier 3 are. As illustrated in FIG. 4 in an enlarged plan view of the tensioning device 12, and as can be seen in FIG. 5, the tensioning elements 13 are arranged on a support element 21 formed as a ring 22 on which the axes of rotation 17 are fixed and protrude from its end face . The same reference numbers apply to the same components.

The ring 22 is supported radially on the base of the receptacle 11 in the assembled state. Another ring 29 is placed over the ring 22 and rests on the end face of the support element 21 or ring 22 in a sliding manner. The further ring 29 forms a control element 18 which has four areas, in each of which a clamping element 13 comes to rest, and on the inside 30 of which a control or inclined surface 15 is arranged.

With a respective control flank 19, each clamping element 13 bears against an inclined surface 15. Each inclined surface 15 takes an acute angle to the circumferential surface of the clamping shaft 10, so that when the control element 18 rotates, the clamping elements 13, which are fixedly arranged on their respective axis of rotation 17, move radially inwards towards the clamping shaft 10 or swivel. A respective locking flank 20 opposite the respective control flank 19 of a tensioning element 13 is pressed into the radial groove 16 of the tensioning shank, slides on the conical, further flank 38 of the radial groove 16 and pulls up the tensioning shank 10, an axial force and a radial force impressing this, in the receptacle 1 1, whereby the contact surface 6 and the bearing surface 7 come to rest on each other without play.

On its outside 31, the ring 29 has a toothed section 25 which, in the exemplary embodiment shown, is guided around the entire outer circumference of the ring 29.

The actuating element 14, which is formed as a screw 23, engages in the toothed section 25 and, when actuated, causes the control element 18 to rotate about the longitudinal axis 26 of the receptacle 11.

The actuating element 14 is supported in a guide 27 radially and also axially against pivoting. A guide 27 in the manner of a bore is shown in FIG. 6. A guide 27 is provided for each tool carrier 3 and is guided from a respective end face 28 of the tool carrier 3 to the respective toothed section 25 of the control element 18.

As shown in FIG. 4, in a particularly preferred exemplary embodiment of the fixing device 1, the respective control flank 19 and the locking flank 20 are formed on the tensioning elements 13 in the manner of an arc segment. The circular arc segments are each conical to each other. An outer diameter D of each support element 21 and of a control element 18 is of the same size, so that the clamping device 12 is easy to manufacture and assemble.

For this purpose, the support element 21 with the clamping element 13 and its axes of rotation 17 together with the support element 21 is moved into the receptacle 11 of the tool carrier 3 along the longitudinal axis 26 and in a cylindrical fit at the base of the receptacle with a snap ring 32 which is in a Groove 33 arrives in the receptacle 1 1, axially immovably secured.

The clamping shaft 10 can be designed in various ways. It can be designed in the manner of DIN 69880 and have at least one cylindrical length range. It can also be formed with a diameter reduction, as shown in FIG. 1, its diameter decreasing from an end 34 facing the contact surface 6 on the tool holder 2 to the end 35 facing away from the contact surface 6.

Oesterle & Partner

Place Talstrasse 21

72202 Nagold

Reference list

(1) fixing device

(2) tool holder

(3) Tool carrier

(4) fastener, first

(5) Alignment device

(6) contact surface

(7) contact surface

(8) fastener, second

(9) quick release device

(10) tension shaft

(1 1) recording

(12) tensioning device

(13) clamping element

(14) actuator

(15) Bevel, control surface

(16) radial groove

(17) axis of rotation

(18) control

(19) control edge

(20) locking flank

(21) support element

(22) ring

(23) screw

(24) thread, on 23

(25) gear section

(26) longitudinal axis, v. 1 1

(27) Leadership, for 14

(28) face

(29) ring

(30) inside, v. 29

(31) outside, v. 29

(32) Snap ring

(33) groove

(34) end, v. 10th

(35) end, v. 10th

(36) threaded hole

(37) drive shaft

(38) flank (D) outer diameter, v. 18, 21

Claims

1. Fixing device for machine tools for fixing at least one tool holder

(2) on a tool carrier

(3), with a first fastening device

(4) with clamping screws for precise positioning of the tool holder (2) on the tool carrier (3) below

Effect of an alignment device

(5) between a contact surface

(6) of the tool holder (2) and a support surface

(7) of the tool carrier (3), and with a second fastening device

(8) in the manner of a quick release device

(9) with at least one clamping shank protruding from the tool holder (2)

(10) which in a recording

(1 1) can be guided in the tool carrier (3) and can be locked with at least one clamping device (12) of the quick-clamping device (9), characterized in that the clamping device

(12) at least one tensioning element

(13) and an actuator

(14) for the clamping element (13) and the clamping element (13) on a control surface

(15), which lies radially opposite the clamping shaft (10) in the receptacle (1 1), and when the actuating element (14) is actuated, the control surface (15) moves in the circumferential direction of the clamping shaft (10) and the clamping element (13 ) executes a movement directed radially to / from the clamping shaft (10), which movement locks and locks in a form-fitting manner

Fixing the clamping shaft (10) in the receptacle (1 1).

2. Fixing device according to claim 1, characterized in that the clamping element (13) in a radial groove

(16), which is arranged around the circumference of the clamping shaft (10).

3. Locking device according to claim 1 or 2, characterized in that the clamping element (13) on a fixed, in the receptacle (1 1) in the tool carrier (3) arranged axis of rotation

(17) is fixed and that a control element having the control surface (15)

(18) under the action of the actuating element (14) on a control flank

(19) of the

Clamping element (13) is arranged to be displaceable along that the clamping element (13) with a locking flank

(20) swings into the radial groove (16) of the clamping shaft (10) when the actuating element (14) is actuated. 4. Fixing device according to claim 3, characterized in that the

The axis of rotation (17) for the clamping element (13) is supported indirectly in the receptacle (1 1) in the tool carrier (3) via a support element (21).

5. Fixing device according to one of claims 1 to 4, characterized in that the support element

(21) is formed as a ring (22) and that on the ring

(22) at least two diametrically opposed ones

Clamping elements (13) are arranged over respective axes of rotation (17).

6. Fixing device according to claim 5, characterized in that four clamping elements (13) are arranged in a cross arrangement on the support element (21). 7. Fixing device according to one of claims 1 to 6, characterized in that the actuating element (14) in the manner of a screw

(23) is formed with its thread

(24) in a gear section

(25) of the control element (18) engages and that the control element (18) rotates about a longitudinal axis when the screw (23) is actuated

(26) of the receptacle (1 1) in the tool carrier (3).

8. Fixing device according to one of claims 1 to 7, characterized in that the actuating element (14) in a guide (27) axially

is supported and that leadership

(27) in the manner of a hole made by another face

(28) as the support surface (6) of the tool carrier (3) in or the tool carrier (3) to the toothed portion (25) of the control element (18) is formed.

9. Fixing device according to one of claims 1 to 8, characterized in that the control element (18) as a ring

(29) is formed on the inside

(30) the control surfaces (15) for the clamping elements (13) are arranged and on the outside thereof

(31) the toothed section (25) or a toothing extending around the entire circumference of the ring (29) is arranged, into which the thread (24) of the actuating element (14) engages.

10. Fixing device according to one of claims 4 to 9, characterized in that the bearing element (21) and the control element (18) have the same outer diameter (D) and by means of a snap ring

(32), which engages in a groove (33) in the receptacle (1 1), are axially immovably secured.

11. Locking device according to one of claims 1 to 10, characterized in that the respective control flank (19) and the locking flank (20) of the clamping element (13) are each formed in the manner of a circular segment and the circular arc segments tapering towards one another on the clamping element (13) are arranged.

12. Fixing device according to one of claims 4 to 1 1, characterized in that the clamping elements (13), the control element (18) and the support element (21) for mounting in the receptacle (1 1) of the tool carrier (3) along the longitudinal axis (26) of the receptacle (1 1) and are fixed in the receptacle (1 1).

13. Locking device according to one of claims 1 to 12, characterized in that the clamping shaft (10) is cylindrical or with a diameter reduction from its, the contact surface (6) of the tool holder (2) facing end (34) to the, the contact surface (6) facing end (35) is provided.

14. Fixing device according to one of claims 1 to 13, characterized in that the clamping shaft (10) is formed in the manner of DIN 69880 ge and has at least one cylindrical length range or that the clamping shaft (10) as a tool shaft for BMT tool carrier systems (base mounted turret) is formed.

15. Fixing device according to one of claims 1 to 14, characterized in that a plurality of tool holders (2) and fixing devices (1) are arranged on a tool carrier (3).