WO1989007996A1 - Tool change system - Google Patents

Abstract

A tool change system with a holder (1) for a tool (4) to be held by means of an expansion mandrel and/or for a workpiece, with thin outer wall regions in the holder, a shifting device for generating a hydrostatic pressure for deforming the thin outer wall regions, with a first piston and a second chamber system filled with a hydraulic medium, is characterized in that the first chamber system contains several mutually communicating chambers (28) aligned in groups of at least one chamber so that the tool can be centred and/or chucked in any desired position in the holder.

Description

 DESCRIPTION

Tool changing system

The invention relates to a tool changing system with a receiving body for a tool and / or workpiece to be picked up by means of a stretching device, with thin-walled outer wall areas in the mounting which are adjacent to a first chamber system filled with a pressure medium, with a displacement device , with which a hydrostatic pressure can be generated in the first chamber system, whereby the thin wall areas against the one to be absorbed

Tools are applied, that the same in the receiving cen- trierbar and / or exciting durable, ben with a first Kol¬ and filled with a pressure medium second Kammer¬ system that verbun¬ flow-connected with the first chamber system ^'as well as with the is connected to the first piston in such a way that a pressure can be built up in the second and thus also in the first chamber system by moving this piston. is.

Tool changing systems of various types are known in which hydraulic fluid is used as the pressure medium. In a known version of a tool change system, the tool to be clamped is centered via a holding cone. Another known embodiment uses a cylindrical receptacle, e.g. B. the so-called ABS system. These tool clamping systems are secured and fastened, for example, by means of a bolt system which clamps the tool changing system in the spindle, or by means of a cylinder screw (expansion screw) which is arranged centrally and connects the tool changing system to the spindle. A disadvantage of all previous systems are the poor roundness, due to the functional principle! properties. The previous tool change systems are susceptible to contamination due to their "open" design. The ABS system has further disadvantages due to tension in the area and the inadequate controllable influence of the entire tension state. Removable parts, such as unsecured screws, represent danger points of previous tool change systems. As a result, these clamping systems are unsuitable when it comes to the highest precision in concentricity and repeat accuracy. However, these properties are of crucial importance, especially for high-speed machining.

A tool changing system of the generic type, which has a first chamber system with only a single chamber, is not optimal in terms of its centering properties, which in turn has a negative effect on the concentricity and repeat accuracy. In addition, there is a high manufacturing cost, which places narrow limits on the economic use of such a tool changing system.

The invention has for its object to provide a tool changing system of the type mentioned, which is characterized by best concentricity and good repeatability and at the same time opens the way to a simplified and therefore cheaper production. The tool changing system should also be able to be inserted into the receptacle without play. For safety reasons, there should not be any easily removable parts. The Werk¬ tool change system should also insensitive against pollution Ver¬ ^"z. B. by cooling water and chips and his ness same time feature a high elasticity and great rigidity, which is absolutely necessary in view of the required high precision.

This object is achieved by the features characterized in claim 1, the secondary claims 2, 3, 24, 42, 45. The tool changing system according to the invention is characterized in accordance with claim 1 in that the first chamber System contains several communicating chambers, which are aligned in groups of at least one chamber so that the tool can be centered and / or held in an exciting manner in the receiving body. A very high centering accuracy can be achieved by dissolving the first chamber system into several independent chambers, since it is possible to first center the tool / workpiece specifically over certain contact surfaces and then to clamp it in the receptacle.

According to the independent claim 2, the tool changing system according to the invention is additionally characterized by a device for locking the tool, which has a particularly advantageous effect when such tool changing systems are used in the context of fully automatic production. According to the characterizing feature of independent claim 3, the pressure-generating displacement device has at least one first piston in the form of an annular piston, the central longitudinal axis of which coincides with the longitudinal axis of the receiving body, and the first chamber system contains one or more chambers communicating with one another. Such a tool change system has a simple structure, as a result of which the costs of manufacture 1 can be reduced and nevertheless a high degree of precision can be maintained.

According to the independent claim 24 of the body Aufnahme¬ consists of ^'at least two parts, namely a base unit and a stretching unit. The stretching unit has the receptacle for a workpiece and / or tool to be held and the holding area of the base unit and the stretching unit are designed such that the first chamber system can be produced by joining the base unit and the stretching unit. By dividing the receiving body into two parts, which are then joined together, the Manufacture of the same is significantly simplified, which significantly reduces the production costs.

Regardless of whether the receiving body in two parts, i. H. is provided with expansion part and base part, with several chambers, with a device for locking or with a displacement device, the basic unit is constructed from an outer base body and an inner base body according to the characterizing features of claim 42, the expansion unit is attached to the inner base body, a spring unit is present between the inner base body and the outer base body, and the outer base body is suitable for inclusion in a machine tool and forms a play-free bearing unit for the inner base body, which is only one Relative displacement activating the spring unit in the longitudinal direction of the axis of rotation of the basic unit enables. This makes it possible for the outer basic unit to be supported in the holder of a machine tool and then, after applying a further clamping stroke, to support the inner basic unit on corresponding flange surfaces of the machine tool by means of existing flange contact surfaces, as a result of which a very rigid construction is achieved overall becomes. In addition, the distance between the tool and the machine tool is always constant, which has a favorable effect on the handling and production speed in the context of a fully automatic manufacturing operation.

According to a further very essential development of the invention, the tool changing system is characterized in that a locking device is provided which is present in the locked state with little play, ie floating in the receiving body. This floating bearing ensures that the clamped tool can always be precisely aligned in the base body; when the thin wall regions in the base body holding the tool are expanded, the thin ones that expand inward shift Wall areas the workpiece together with the locking device in the exact position for the workpiece. Such a tool changing system is not only precisely positionable in a simple manner, but also safe to use, since if the pressure built up by the pressure medium drops, the workpiece cannot fall out of the base body due to its locking. Special embodiments for such a locking device can be found in subclaims 46 to 49.

Other further developments of the invention are presented in the remaining subclaims and in the following description of the figures.

The tool change system according to the invention will now be explained in more detail with reference to FIGS. 1 to 14 of the attached drawings in terms of its function and its structure. The following show:

Figure 1 is a schematic diagram of the tool changing system.

Fig. 2 is a schematic diagram of the cam ring;

3 shows the development of the cam ring according to FIG. 2;

4 shows a further section through the tool change system according to FIG. 1;

Fig. 5 is a sectional view of the tool changing system of FIG. 1, through the expansion chambers in the untensioned

Status;

6 shows a sectional illustration of the tool changing system according to FIG. 1, through the expansion chambers in the clamped state with the workpiece; Fig. 7 is a Schn tdarstel ung 1 ^"by the tool change - the system of Figure 1, wherein only one expansion chamber.

8 shows a basic illustration of a further embodiment of the tool changing system;

9 shows a principle of a tool change system which is tensioned via a spiral ring;

10 is a sectional view through the spiral ring, transverse to the central axis;

11 shows a basic illustration of a tool change system which is tensioned via a pull rod;

12 shows a basic illustration of a tool change system which is tensioned via a spring assembly;

13 shows a sectional illustration of a tool change system with a base unit and an expansion unit, the base unit t having an inner and outer base body and the inner base body being mounted in the outer base body;

Fig. 14 is a section tdarstel! by a tool changing system with an expansion unit and a base unit, the expansion unit having recesses from its side facing the base unit to form the first chamber system;

15 shows a sectional view through a tool changing system with a base unit, stretching unit and locking device through the stretching unit; 16 shows a sectional view through the tool changing system according to FIG. 15 along the line 16-16.

A base body 1 of a tool changing system is firmly connected to a receptacle 3 by means of several screws 2. The receptacle 3 is designed as a steep taper, for example. The screws 2 are secured against unintentional loosening. The connection of receptacle 3 and base body 1 can also be carried out in other ways, for. B. by gluing, soldering, welding or as a one-piece design.

The tool 4 is inserted into the receiving bore 5 of the basic body 1, locking pins 7 being pushed radially outward with the insertion part 6 which forms a front-side taper. As a result, locking pins 8 are made

their initial position pressed against springs 9. Finally, if the tool 4 is in contact with a flat system 10 of the receptacle 3, the locking pins 7 automatically snap into an annular groove 11 in the tool 4 due to the action of the spring 9 and the locking pin 8 and thus secure the tool.

The tooling 4 is centered and clamped via a cam ring 12. The cam ring 12 has one or more bevels 13 or 23, the angle of inclination of which can be different.

As can be seen from Fig. 1 and Fig. 4, the clamping piston 14, 24 engage in these bevels 13, 23 clamping piston 14, ^"24 a. By rotating the cam ring 12 are these bevels 13, 23 with their D chtungselementen 15, 25 axially displaced and in each case a specific defined hydrostatic pressure p or p is generated in two separate chamber systems 16 or 26, the chambers 18 and the expansion chambers 28 are thereby produced with the respective pressure via ring channels 17 or 27 Each chamber 18 interacts with a clamping bolt 20, which in turn presses against a locking pin 7. The desired pressures p, p can be set as desired by the design dimensioning of the clamping pistons 14, 24 Pressure increase per degree of rotation of the cam ring 12 is determined by the respective angle of inclination of the bevels 13, 23.

In order to obtain optimal concentricity, it is advantageous according to the invention to carry out the centering process of the tool and the clamping of the tool one after the other. Both processes are carried out by means of the cam ring 12, the chronological sequence of these processes being determined by the design parameters, such as, for. B. the choice of bevels 13, 23, the diameter of the clamping pistons 14, 24 and the clamping bolt 20 and thus the pressure generated in the chamber system. When the cam ring 12 is actuated manually by means of a turnbuckle or automatically by a gripper system, the centering process is first initiated (see FIG. 4). over the angled surface 23 of the cam ring 12 and the clamping piston 24 with the sealing member 25 is transmitted 28 a hydrostatic pressure p in the chamber system 26 generates and n via the annular channel 27 to a plurality of expansion chamber ^'. These expansion chambers 28 represent cylindrical indented cutouts and, in accordance with FIGS. 5, 6, are designed such that the pressure p _z generated by the actuation of the cam ring 12 causes a certain deformation 29 of the expansion chamber 28, corresponding to FIG. 6. The wall thickness s of the expansion chambers 28 is adapted to the particular clamping task. 5, 6, the tool 4 is centered on the center of the axis. This process can be seen from FIGS. 5, 6, where, for example, four groups of two expansion chambers 28 are circumferentially evenly distributed.

Another arrangement or distribution of the expansion chambers 28 can also be carried out. The individual expansion chambers 28 can also be operated separately, i. H. if necessary, different hydrostatic pressures must also be applied. This can be advantageous according to the invention if the tool 4 initially has a certain measurable offset in the tool changing system, which is compensated for by the choice of a certain pressure distribution within the expansion chambers 28.

Instead of a large number of individual expansion chambers 28 (FIGS. 5, 6), it is also conceivable and possible according to the invention to use a single, centrally arranged expansion chamber 30, corresponding to FIG. 7.

The advantage of the embodiment according to FIGS. 5, 6 is that the tool changing system can be constructed very stiffly due to the large number of expansion chambers 28. The expansion chambers -28 can also be easily manufactured and manufactured is another advantage.

The clamping process of the tool 4 is initiated by further turning the cam 12. This is done in analogy to the centering process of the tool already described (cf. FIG. 1).

Due to the hydrostatic pressure p generated, the sealing element 19 and clamping bolt 20 are pressed firmly against the locking pin 7. The locking pins 7 cause a force component in the axial direction, which is greater than the centering force acting in the radial direction, via a bevel 21 of the pin 7 and the annular groove 11. This can be done constructively by specifying the respective chamber pressures p and p. As a result, the tool 4 is pressed firmly against the plane system 10 in the longitudinal direction. In accordance with the invention this ensures that the central axis of the tool 4 and the central axis of the tool changing system are aligned in parallel and centered at the same time.

The tool 4 is thus securely clamped and centered. Additional mechanical securing in the event of a possible drop in pressure in the hydraulic system 16, 17, 18 is achieved by a plurality of securing balls 22 which limit the paths of the locking pins 7. The tool 4 is thus secured in two ways. This is particularly important in the case of automatically controlled manufacturing processes.

Changing (resolve) the tool 4 is also carried out via the ^cams' ring 12, but in the reverse direction. When releasing the pressure and thus releasing the locking, the balls 22 slide more or less into the cam ring, so that the locking pin 7 can move sufficiently far outwards.

To ensure good repeatability of the concentricity of tool 4 and at the same time a clear term fixation z. B. to reach the tool cutting edges, a positioning pin 31 is provided according to the invention, which is provided in the area of the plane contact 10 between the tool 4 and the base body 1.

In many applications it is desirable to supply coolant directly to the cutting edges through the tool 4. In Fig. 1, a coolant channel is designated 32. The sealing element 33 prevents contamination of the tool changing system.

It is of course conceivable and possible according to the invention to adapt the holder 3 of the tool changing system to the respective application. Z are widely used. B. steep taper, morse taper or cylindrical receptacles.

Another embodiment of the tool changing system according to the invention consists in designing the receptacle 3 of a tool changing system in such a way that it can be inserted into a second tool changing system and centered and clamped therein. This makes it possible, for example, to simulate an extension of the drive axis or to hold tools with different clamping diameters. This increases the flexibility of this clamping system with regard to its use.

As mentioned, the tool changing system can be operated manually, for example by means of a suitable wrench, or automatically. In the case of automatic actuation, it makes sense to lock the cam ring 12 by means of gripping pliers and to rotate the cam ring 12 and thus to actuate the tool change system via the spindle drive of the machine.

The tool changing system according to the invention can be used for the most varied fields of application. It is conceivable and possible to clamp tools of the most neat kind as well as to hold workpieces for clamping purposes. The symmetrical structure and the rigid design are of decisive advantage, in particular at high rotational frequencies. The system is therefore preferably suitable for high-speed machining. At the same time, through the selected arrangement of the expansion chambers 28 and their structural design, the tool changing system has a vibration-damping effect. This ensures a high surface quality of the workpieces to be machined and a simultaneous increase in tool life. It is therefore readily apparent that an important application of this tool changing system is in the area of modern manufacturing processes. In particular, this is due to the features mentioned such as highest round! Accuracy, double security when clamping, insensitivity to dirt, rigid construction with large clamping forces and increased service life of the insert tools achieved through good vibration damping properties.

In FIG. 8 is a schematic ^'diagram of another Ausfüh¬ tion the tool change system illustrated. A clamping nut 34 meshes on an external thread 35 present on a base body 1.1. By screwing in the clamping nut 34 by means of the thread 35, it is displaced in the axial direction. Contamination of the thread 35 and of an annular piston 36, which corresponds functionally to the tensioning piston 24 and which is present radially symmetrically to the longitudinal axis, is prevented by a sealing element 37. If the clamping nut 34 r is actuated, the annular piston 36 is simultaneously displaced accordingly. To reduce the friction losses, several balls 38 or other friction-reducing elements are provided here. The annular piston 36 generates a hydrostatic pressure in the chamber system 40 via the ring-shaped sealing element 39, which is supplied via capillaries 41 to a centrally arranged expansion chamber 28.1. The deformation and thus the clamping force of the tool change can therefore be achieved via the clamping nut 34 Systems can be adjusted dosed. In FIG. 8 a tool 4.1 is provided with a shaft 42 slotted at its end. Through this invention The design of the tool shank 42 ensures that, as a result of the centrifugal force at high rotational frequencies, an additional holding force is generated which acts as an additional dynamic stabilization. 05

FIG. 9 shows the basic illustration of a tool change system which is stretched over a spiral ring. A tool 4.2 is inserted into a base body 1.2, which is clamped and fixed via a spiral ring 43

10 will. For this purpose, spiral-shaped recesses 44 are machined into the spiral ring 43, in which one or more locking pins 7.1 are guided, which serve to fix the position of a tool 4.2, and further spiral-shaped recesses 45 are used to tension pistons 24.1 and sealing

15 elements 25.1 axially displaced and a hydrostatic pressure is generated in the chamber system 26.1, which clamps the tool 4.2 and / or workpiece non-positively via the expansion chamber 28.2.

20 shows a sectional illustration transverse to the central axis through the spiral ring 43. The locking pins 7.1 are here, for example, introduced into the fixing groove 46 of the tool 4.2, the locking pins 7.1 are guided over the spiral recesses 44. 25th

In the embodiment of tool changing system of FIG. 11 is a tool 4.3 and / or the workpiece via a drawbar ^'47 which is centrally passed through a spindle 48 of the Werk¬ generating machine, tensioned. A thread 49 is provided here as an example to secure the tool 4.3. The tool 4.3 is seated in a base body 1.3, which in turn is to be fastened in the spindle 48. Both the tool in the base body and the base body In the spindle are held by means of the stretching technology. When the pull rod 47 is actuated 35, a tensioning piston 24.2 with the sealing element 25.2 is simultaneously axially displaced and a hydrostatic pressure is generated in a chamber system 26.2 in the base body 1.3. This pressure is generated via first capillaries 41.1 fed to a first expansion chamber 28.3, which is present in the outer circumferential area of the base body. Further capillaries 41.2 branch off from this expansion chamber 28.3 to form a further expansion chamber 28.4, which is present in the inner peripheral region of the base body 1.3. The base body can be clamped in the spindle via the first expansion chamber 28.3 and the tool can be clamped in the base body via the second expansion chamber 28.4. The tool 4.3 can also be non-positively centered and clamped.

In the embodiment of the tool change system according to FIG. 12 _. the force required to actuate the tensioning piston 24.3 is applied by a spring assembly 50, in this case, for example, a disk spring assembly, which is introduced into the base body 1.4. The spring assembly 50 transmits its force via an intermediate element 51 to one or more transmission pins 52, which in turn actuate both the tensioning piston 24.3 and the locking pin 7.2. The locking pins 7.2 engage in a fixing groove 46, which is located in a tool 4.4, ^' egg n. By way of an eccentric 53, the spring assembly 50 can be tensioned again, for example.

It is also possible to actuate the tensioning piston 24.3 in the axial direction via a toothed operation. More activities possible ^! i th are also conceivable and possible, but should not be detailed here.

This work always talks about clamping a tool. However, the tool changing system according to the invention can also be used to solve more general clamping tasks. The hydraulic expansion chuck 60 shown in FIG. 13, which is suitable for use in a work spindle 62 (shown only schematically) with a cone, has a first base body 64, a second base body 66 and an expansion sleeve 68 which can be inserted into the first base body 64 with a cylindrical receptacle 69. The expansion sleeve 68 designed as a cylindrical sleeve has on its outside an upper annular groove-like recess 70 and a lower annular groove-like recess 71. The expansion sleeve 68 is guided in the first base body 64 by means of a first press fit 72 and a second press fit 74 within a bore 75 present in the first base body 64.

To fix the position of the expansion sleeve 68 in the first base body 64, a fixing device, in the special embodiment example a union nut 76, is provided. In the case of larger dimensions, the design of the fixing device as a flange ring can be considered. The thread of the union nut 76 engages in an external thread provided on the first base body 64. As an additional security measure, the thread surfaces of the union nut 76 and those of the external thread can be glued together. The expansion sleeve 68 and the first base body 64 are designed in the end region facing the workpiece to be clamped in such a way that the expansion sleeve 68 is pressed onto the first base body 64 via corresponding contact surfaces 77 when the union nut 76 is screwed in, as a result of which both an axial fixation and a torque ¬ ment fixation of the expansion sleeve 68 is guaranteed.

In the area between the upper groove-like recess 70 and the lower annular groove-like recess 71, the wall thickness of the cylindrical sleeve of the expansion sleeve 68 is somewhat reduced. Above the upper annular groove-like recess 70 and below the lower annular groove-like recess 71, an O-ring is arranged in the wall of the first base body as a sealing means, so that when the expansion sleeve 68 is inserted in the first base body 64, the expansion ring 68 Rings 78 lying outer wall areas of the expansion sleeve 68 and the wall of the bore 75 of the first base body 64, a chamber system is formed. By pressurizing this chamber system, a workpiece / tool introduced into the receptacle 69 of the expansion sleeve 68 is centered or clamped. The O-rings 78 are special plastic rings that ensure the tightness of the chamber system even with large pressures.

An ^'this chamber system includes an existing basic body 64 in the first oil passage 80 on, with about the chamber system

Hydraulic oil is supplied. This oil passage 80 is not engaged with one another in Fig. 13 in detail dargestell th ^'zwei¬ th chamber system in connection which can be acted upon in a conventional manner with pressure, whereby the expansion sleeve in the region between the annular groove-like recesses 70, 71 to the rotational axis R expands the hydraulic expansion chuck and thereby enables centering and / or clamping of a workpiece.

If a union nut to secure the position of the expansion sleeve is to be dispensed with, a pin can alternatively be provided in the area below the lower annular groove-like recess of the expansion sleeve. In a further embodiment, a flanged edge is provided in the region of the opening of the bore 75 of the base body 64, which is deformed accordingly after the expansion sleeve has been installed in order to secure the expansion sleeve in its installed position.

In a further embodiment, the end face of the stretching unit could be smooth and with a larger size

Diameter as shown in Fig. 3 are executed. The expansion sleeve then has, as it were, a circumferential, transversely projecting collar on the end face, through which it can be fastened to the first base body with the aid of, for example, screws, rivets or the like. The expansion unit thus receives an axial fixation as well as a torque fixation. Instead of providing two circumferential annular groove-like recesses, it is also possible to arrange longitudinal grooves on the outside of the cylindrical sleeve of the expansion sleeve, the areas between the longitudinal grooves having a smaller wall thickness, so that appropriate sealing measures can also be used to join them together _. a chamber system is created from the expansion sleeve and base body.

The second base body 66 has a conical shape, the outer wall regions 79 of which are inclined in accordance with the cone 1 of the work spindle 20. In the second base body 66, the first base body 64 is mounted without play, in such a way that a relative displacement between the two base bodies in the direction of the axis of rotation R of the hydraulic expansion chuck 60 is possible, but a relative movement perpendicular to the axis of rotation R is prevented.

The first base body 64 has flange regions 82 which protrude beyond the second base body 66 and which at least in regions have outer surfaces 84 which are designed in accordance with the shape of the opposite outer surfaces of the working spindle 62.

13, the above-described mounting of the first base body 64 in the second base body 66 is ensured by means of linear ball bearings 86. Between the first base body 64 and the second base body 66, a plate spring assembly 87 is arranged symmetrically to the rotation axis R. When the hydraulic expansion chuck 60 is introduced, the same is first drawn into the conical recess of the spindle by means of a pull bolt 88. As a result, the outer surface 79 of the second base body 66 lies against the inner wall of the spindle cone. Now the first base body 64 can be drawn further into the spindle by means of the pull bolt 88. This is a in the plate spring assembly 87

Spring force built up, which acts on the second base body 66 and presses it into the spindle. After a predeterminable clamping stroke has been reached, the outer surfaces 84 lie down of the flange areas 82 of the first base body 64 to the corresponding outer wall areas of the work spindles 62. This additional application of the flange areas 82 of the first base body 64 results in a substantially larger support surface for the expansion chuck 60 on the spindle 62, which results in an overall stiffer construction, which is beneficial for the round! accuracy of the chuck affects. With such a design of the expansion chuck it also has a favorable effect that the distance between the tool and the spindle is constant, and the precision of machining when fully automatic gripping devices for such expansion chucks are used can thereby be significantly improved .

In order to protect the linear ball bearing 86 against penetrating drilling water or other contaminants, sealants, for example an O-ring 89 present in the wall of the second basic body 66, are present between the first basic body 64 and the second basic body 66.

In the hydraulic expansion chuck 90 shown in FIG. 14 there is a base body 92 suitable as a taper 1 cone and an expansion sleeve 96 containing the receptacle 94 for a workpiece. The expansion sleeve 96, like the expansion sleeve according to FIG. 13, is fixed in the installed state with respect to the position of the base body 92 by means of a union nut 98. The expansion sleeve 96 is also guided by means of a first press fit 100 and a second press fit 102 in the corresponding contact surfaces of the base body 92.

From the side facing the base body 92, the expansion sleeve 96 initially has open recesses 104 which are arranged parallel to the axis of rotation R of the expansion chuck 90 and which, when the expansion sleeve 96 is installed, form the first chamber system in the base body 92. According to FIG. 14, this chamber system is formed by an annular recess 104 arranged around the receptacle 94. The sealing This chamber system 104 is operated by means of an O-ring 106 which is introduced into the recess 104 and is, for example, mounted on a support ring 108, this Teflon ring being supported on an inserted steel ring 110. In the installed state of the expansion sleeve 96, the steel ring is supported on a correspondingly opposite flat surface of the base body 92. This steel ring 110 is used as an insert and is used to set the active clamping length of the expansion sleeve 96.

The recesses 104 are preferably produced by electrical discharge machining.

A bore 112, which forms the first half of an oil channel, adjoins the recess 104 and runs obliquely downwards. A corresponding second bore 114 is present in the base body 92 and forms the other half of the oil channel. A further chamber system adjoins this oil channel, which can be loaded with the pressure required for clamping a workpiece, and which is not shown in FIG. 14.

To simplify installation, a circumferential ring channel 116 is provided on the outside of the expansion sleeve 96 facing the base body 92 at the level of the opening of the first bore 112, so that the expansion sleeve 96 can be installed in any rotated position relative to the base body 92 without the hydraulic Connection of the first half 112 of the oil channel and the second half 114 of the oil channel is interrupted. This ring channel 116 is sealed by means of two 0-rings correspondingly arranged on the outside or inside of the ring channel 116.

In another embodiment according to the invention, instead of the circumferential circular recess, individual cylindrical recesses are arranged, which are present on a circle arranged concentrically for receiving the expansion unit. In a further variant, the formation of an annular channel is dispensed with. Instead, there are special guide units which only allow the expansion sleeve and base unit to be joined together in a certain orientation, so that the opening of the first bore comes to lie exactly above the opening of the second bore and thus a continuous oil channel is created.

In the hydraulic expansion chuck 120 shown in FIG. 15, only its upper part, the base body 122, is shown in section. An expansion sleeve 124 is inserted in this base body 122. It is designed in its upper and lower area as a cylindrical sleeve such that it fits snugly in the area of its upper and lower end-side outer wall areas in the longitudinal bore 130 of the base body 122.

In its central area, this expansion sleeve 124 has a circumferential annular bead 132. Its transverse extent is such that it also fits snugly in the base body 122 with a fit 134 or 136, 138.

To fix the position of the annular bead 132 in the base body 122, a pressure sleeve 140 with an L-shaped cross section is used, which rests against the annular bead 132 both from above and laterally. Their pressing contact on the annular bead 132 is ensured by means of a screw 142, which can be screwed 144 into the base body 122 such that it can exert a corresponding pressure on this pressure sleeve 140. The annular bead 132 is thus clamped in the longitudinal direction between the pressure sleeve 140 and the base body 122.

Below the annular bead 132 there is an annular gap between the base body 122 and the longitudinal bore 130 such that a lower chamber 146 surrounding the expansion sleeve in a ring-like manner is formed by the latter. This chamber 146 is sealed towards the bottom by an O-ring 148, which in turn is between an upper support ring 149 and a lower support ring. ring 150 is present. The presence of the ring 149 allows the amount of pressure medium in the lower chamber 146 to be reduced.

Above the annular bead 132 there is an annular gap which also surrounds this area and which, like the lower chamber 146, represents an upper chamber 152. This chamber 152 is sealed at the top by an O-ring 154, which in turn is supported in a positional manner on a support ring 156.

In the longitudinal direction across the annular bead 132, there are two longitudinal bores 158, 160. These two bores open into an annular groove 162 or 164, which is triangular in cross section in the drawing, and which have a line connection with the lower chamber 146 and with the upper chamber 152. In the present example sfal 1, the lower annular groove 162 is connected to an oil supply (not shown in more detail) via a tap hole which represents an oil channel 166. The pressure medium flowing through the oil channel 166 thus passes into the lower annular groove 162 and from there into the lower chamber 146 and through the two longitudinal bores 158 and 160 into the upper annular groove 164 and further into the upper chamber 152 0-rings 148 and 154 prevent this pressure medium from escaping in the longitudinal direction upwards and downwards from the chambers 146 and 152, respectively. An additional 0-rings 168 or 170 between the annular bead 132 and the pressure sleeve 144 or the base body 122 also prevents the pressure medium from escaping in these areas. With a corresponding pressure build-up in this pressure medium, the walls of the expansion sleeve 124, which are adjacent to the lower chamber 146 or upper chamber 152, are expanded so that a tool inserted into the longitudinal bore 190 of the expansion sleeve 124 in these areas,. H. twice in the longitudinal direction, is held in the base body 122.

In the ring bead 132 is from one side - in the drawing right side - from a transverse bore 172 through this ring bead available. In this transverse bore 172 there is a locking device 174 designed as a rotating part, the outer dimensions of which are smaller than the diameter of the bore, so that it sits in this transverse bore 172 with play. The longitudinal extent of this locking device, which is designed as a clamping bolt, ie its extension in the transverse direction, is somewhat smaller than the clear dimensions of the base body 122 in this area, so that it also sits with play in the base body 122 in the transverse direction. In its intersection with the longitudinal bore 130, this clamping bolt 174 has a longitudinal bore 176. A tool seated in the longitudinal bore 190 can thus be inserted through the clamping bolt 174 unhindered. To prevent a tool from immersing itself too deeply in the base body 122, a snap ring 178 is provided in the lower region of the expansion sleeve 124 and serves as a support for the lower end of a tool.

From the side, ie in the transverse direction, there is a transverse bore 180 in the clamping bolt 174, which is equipped with an internal thread and which ends in the region of the longitudinal bore 176. A clamping screw 184 is screwed into this transverse bore 180. A tool inserted in the longitudinal bore 190 can be held by means of this clamping screw 184. This hold can be ensured by positive and / or non-positive connection with the tool shank. The clamping screw 184 is accessible from the outside through a lateral bore 186 provided in the base body 122. Because the clamping screw 184 is fastened to the clamping bolt 174, but the latter is floatingly supported in the base body 122, the tool locked by the clamping screw 184 is also floatingly supported in the base body. When activating the print medium, an already locked tool can be moved in the transverse direction so that it is exactly aligned axially. Despite the floating position of the clamping bolt 174 in the annular bead 132 and thus in the expansion sleeve 124, twisting or tilting of this clamping bolt 174 around a vertical axis through the bilateral end face rounded training 189, which is adapted to the corresponding internal curvature of the base body at this point, practically excluded. The expansion chuck 120 described above has the great advantage that the locking effect caused by the clamping screw 184 is integrated into the expansion sleeve 124 and cannot impair the expansion movements caused by the expansion sleeve 124. The lock is used to secure the tool in the base body in the event of pressure loss in the hydraulic system, for example.

Claims

EXPECTATIONS 01) Tool changing system, with - a receiving body (1, 3) for a tool (4) and / or workpiece to be picked up by means of an expansion clamping device, thin-walled outer wall areas in the receptacle, which are adjacent to a first chamber system (28, 30) filled with a pressure medium, - A displacement device (12, 34, 43, 47, 50) with which a pressure can be generated in the first chamber system, as a result of which the thin wall areas can be placed against the tool to be picked up in such a way that the same can be centered in the pickup and / or is excitingly durable, - a first piston (24, 36), - A second chamber system (26, 40) filled with a pressure medium, which is connected in line with the first chamber system (28, 30) and with the first piston (24, 36) in such a way that by displacing this piston in the second and thus also in the first chamber system Pressure can be built up, so that this first chamber system contains several communicating chambers (28), which are aligned in groups of at least one chamber in such a way that the tool can be centered and / or held securely in the receiving body. 02) tool change system ^" according to the preamble of claim 1, characterized in that - The receptacle has a device (7, 42, 47) for locking the tool (4) and - The first chamber system contains one (30) or more (28) chambers communicating with each other. 03) tool changing system according to the preamble of claim 1, characterized in that - The pressure-generating displacement device (12, 34, 43, 47, 50) has at least one first piston in Has the shape of an annular piston (36), the central longitudinal axis of which coincides with the longitudinal axis of the receiving body, and - The first chamber system contains one (30) or more (28) communicating chambers. 04) Tool changing system according to claim 3, so that the receptacle has a device (42) for locking the tool (4). 05) Tool changing system according to one of claims 1 to 3, d a d u r c h g e k e n n z e i c h n e t that the chambers (28, 30) are substantially cylindrically shaped, the longitudinal axis of each chamber being aligned parallel to the longitudinal axis of the receiving body. 06) Tool changing system according to one of claims 1 to 3, characterized in that the displacement device has a cam ring (12) on which there is at least one slope (13, 23) which is in engagement with the first piston (24) that by adjusting the cam ring the piston is displaceable and so the Pressure can be generated in the carn system. 07) Tool changing system according to one of claims 1 to 3, d a d u r c h g e k e n n z e i c h n e t that the displacement device is a clamping nut (34) which engages with the first piston (36) so that the piston is displaceable by adjusting this nut and so Pressure can be generated in the chamber system. 9/07996 _ ₂₆ _ 08) Tool changing system according to one of claims 1 to 3, characterized in that the displacement device has a pull or push rod (47) which engages with the first piston (24.2) so that the piston can be moved and displaced by adjusting this rod . _is, the pressure in the chamber system generated. 09) Tool changing system according to one of claims 1 to 3, characterized in that the displacement device is an elastic _. Element (50) is seated, which is in engagement with the piston in such a way that the piston can be actuated by this elastic element and the pressure in the chamber system can thus be generated. 10) Tool change system according to claim 9, d a d u r c h g e k e n n z e i c h n t that the elastic element can be tensioned by an eccentric. 11) Tool changing system according to claim 2 or 3, characterized in that ^■ - the pressure p generating displacement device has at least one second piston (14), - At least one movably guided locking member (7) is present in an indentation in the tool (11) is submersible, a further displaceable piston (20) presses against the locking member (-7), a third (18) and fourth (16) filled with pressure medium and interconnected chamber system is present, - The fourth chamber system (16) with the second piston (14) and the third chamber system (18) with the further piston (20) are connected so that depending on the size of the existing in the third chamber system Pressure p of the other pistons can be displaced to different extents, so that the locking member can also be inserted to different extents in the tool and thereby the Tool can be pressed in the longitudinal direction of the receiving body against a system (10). 12) tool changing system according to claim 11, 05 d a d u r c h g e k e n e z e i c h n e t that the locking member is a pin movably guided transversely to the longitudinal axis of the tool, against which an elastic element (9) presses so that the pin can be moved transversely to the longitudinal axis in its direction. 10th 13) Tool changing system according to claim 2 or 3, characterized in that the pressure-generating Verschiebeinein¬ device (43, 50, 52) also acts on the locking member (7.1, 7.2) 15, which in the tool (4.2, 4.4) existing indentation (46) can be guided in a submersible manner. 14) Tool changing system according to claim 13, d a d u r c h g e k e n n z e i c h n e t that 20 - the locking device is a ring (43), - In the ring at least a first spiral recess (44), in which the locking member (7.1) can be supported, and at least one second spiral recess (45) is present, in which the first piston (24.1) can be supported. 25th 15) Tool change system according to claim 13, characterized in that the displacement device generating the pressure contains an elastic element (50) which acts both on the first piston (24.3) and on the locking member (7.2) . 16) Tool change system according to claim 15, d a d u r c h g e k e n n z e i c h n e t that ^■ 35 between the elastic element (50) and piston (24.3) DZW. elastic element (50) and locking member (7.2) there is at least one intermediate member (52) which has a first area on the piston and a second area on the locking r pressing member is pressed. 17) Tool changing system according to one of claims 1 to 3, characterized in that the two longitudinally opposite end regions of the receiving body are designed such that a first tool changing system can be inserted with its one end region in the other end region of a second tool changing system and in one Tool comparable way can be centered there and / or clamped or locked. 18) Tool changing system according to claim 2 or 3, d a d u r c h g e k e n e z e i c h n e t that the receiving body has perforations in which cantilevers, which protrude from a tool sitting in the receiving body, are immersed. 19) Tool changing system according to claim 18, so that the cantilever members are at wide rotational frequencies of the tool away from the same spreading shank areas (42). 20) Tool changing system according to one of claims 1 to 3, d a d u r c h g e k e n n z e i c h n e t that a positioning device between the tool and the Recording is present, its ^{"longitudinal} axis can be preselected with a certain position of the Werk¬ zeugs respect. 21) Tool changing system according to claim 20, d a d u r c h g e k e n e z e i c h n e t that the positioning device is a pin (31). 22) Tool changing system according to one of claims 1 to 3, characterized in that at least one channel (32) for supplying coolant to the tool ^• is present in the receptacle, with at least one sealing element (33) preventing contamination of the tool changing system is. 23) Tool changing system according to one of claims 1 to 3, characterized in that the pressure which can be generated in the chamber systems can be set such that the chronological sequence of the centering, clamping or locking process can be determined. 24) Tool changing system according to one of claims 1 to 3 or according to the preamble of claim 1, d a d u r c h g e k e n n z e i c h n e t that - the receiving body consists of at least two parts, a basic unit (64, 92) and an expansion unit (68, 96), - the base unit (64, 92) has a receiving area for the stretching unit (68, 96), - The stretching unit (68, 96) has the receptacle (69, 94) for a workpiece and / or tool to be accommodated, and - The receiving area of the base unit (64, 92) and the stretching unit (68, 96) are designed such that by joining the base unit (64, 92) and stretching unit (68, 96) the first chamber system (70, 71; 104) can be generated. 25) Tool change system according to claim 24, g e k e n n z e i c h n e t d u r c h - A fixing device which effects the axial fixing and rotating fixing of the stretching unit to the base unit. 26) Tool changing system according to claim 25, so that the fixing device is designed as a union nut (76, 98) or as a flange ring with a thread. 27) Tool changing system according to claim 26, characterized in that the thread of the union nut (76, 98) or the flange 'ring is additionally glued to a counter thread corresponding to the base unit. 28) Tool changing system according to claim 25, characterized in that the expansion unit is pinned to the base unit. 29) Tool change system according to claim 24, characterized in that the stretching unit (68) is designed as an essentially cylindrical sleeve with recesses (70, 71) arranged on the outside of the sleeve and the base unit (64) in its receiving area has a corresponding bore for receiving the cylindrical sleeve, so that in the assembled state of the expansion unit (68) and base unit (64) the wall of the recesses and the corresponding opposite wall area of the bore of the base unit (64) the chambers (70, 71 ) form the first chamber system. 30) Tool changing system according to claim 29, so that the recesses arranged on the outside of the sleeve have at least one annular groove. 31) Tool changing system according to claim 29, characterized in that the recesses arranged on the outside of the sleeve have two spaced ring grooves (70, 71), with a further, a smaller depth than that in the entire area between these ring grooves (70, 71) Ring grooves having a circumferential recess is present. 32) Tool changing system according to claim 29, characterized in that the recesses arranged on the outside of the sleeve have at least one longitudinal groove. 33) Tool changing system according to one of claims 24 to 32, characterized in that between the wall of the expansion unit (68) and the wall of the base unit (64) sealing means (78) are present and the walls at least in some areas with a press fit (72, 74) to each other! lie. 34) Tool changing system ■ according to claim 33, so that the sealing rings are provided with O-rings (78). 35) Tool changing system according to claim 24, characterized in that recesses are formed in the stretching unit (96) from its side facing the base unit (92), which in the assembled state of the base unit (92) and the expansion unit ( 96) 'form the chambers (104) of the first chamber system. 36) Tool changing system according to claim 35, characterized in that the recesses (104) run parallel to the longitudinal axis of the stretching unit (96). ^■ 37) Tool changing system according to claim 35 or 36, so that the recesses (104) are produced by electroerosion. 38) Tool change system according to claim 35 or 36, characterized in that in the end region of the recesses (104) facing the base unit (92) of the expansion unit (96) there are sealing means (106). 39) Tool changing system according to claim 38, characterized in that between the sealing means (106) and the receiving area of the base unit (92) the cross section of the recesses (104) 05 expansion unit (96) adapted chucks (110) are available. 40) Tool changing system according to claim 35 or 36, d a d u r c h g e k e n n z e i c h n e t that 10, the recesses have a cylindrical cross-section and are present on a cross arranged concentrically to accommodate the expansion unit. 41) Tool changing system according to claim 35 or 36, 15 d a d u r c h g e k e n e z e i c h n e t that there is only one recess (104) which is arranged in a ring around the receiving region (94) of the stretching unit (96). Z0 42) Tool changing system according to the preamble of claim 1 or one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that - The basic unit in turn consists of at least two parts, an outer outer body (66) and an inner one 25 basic bodies (64), the expansion unit (68) is fastened to the inner base body (64), - A spring unit is present between the inner base body (64) and the outer base body (66) and 30 - the outer base body (66) is suitable for inclusion in a machine tool and forms a backlash-free bearing unit (86) for the inner base body (64), which is only a relative displacement (66) activating the spring unit (87) in the longitudinal direction of the Rotation axis (R) of the basic unit 35 possible. 43) Tool changing system according to claim 42, characterized in that the inner base body is mounted in linear roller bearings (87). 44) Tool changing system according to claim 25, so that the stretching unit has a circumferential, transversely projecting collar on the front side, through which it can be fastened to the base body. 45) Tool changing system according to one of claims 1 to 3 or according to the preamble of claim 1, d a d u r c h g e k e n n z e i c h n e t that the locking device (174, 184) in the locked state with little play, d. H. is floating in the receiving body (122). 46) Tool change system according to claim 45, so that the receiving body consists of at least two parts, a basic unit (122) and an expansion unit (124), - the basic unit (122) has a receiving area for the stretching unit (124), - the stretching unit (124) has the receiving for a workpiece and / or tool to be picked up, the receiving area of the base unit (122) and the expansion unit (124) ^{'are designed} such that the first chamber system (146, 152) can be produced by joining the base unit and expansion unit, - • on the stretching unit (124) there is a circumferential collar (132) extending in the transverse direction, at least one line connection (158, 160) is provided through this collar (132), through which the areas of the first chamber system (146, 152) present in the longitudinal direction above and below this collar can be tightly connected, - There is a radial transverse bore (172) in this collar (132), - A cylindrical part (174) is present in the transverse bore (172) with little play to the same, - In the cylindrical part (174) there is a bore running in the longitudinal direction. (176) is present through which the tool and / or workpiece can be passed, - In the cylindrical part (174) there is a transverse bore (180) with an internal thread with respect to the longitudinal direction, which ends in the longitudinal bore (176) and in which a screw part (184) can be screwed is. 47) Tool changing system according to claim 46, so that a molded part (140) can be pressed against the stretching unit (124) in such a way that the stretching unit (124) is tightly present between this molded part 140 and the base body 122. 48) Tool changing system according to claim 47, so that the molded part (140) can be pressed in the longitudinal direction against the collar (132) of the stretching unit (124) by means of a screw part (142) which can be screwed onto the base body. 49) Tool changing system according to claim 46, so that a hole (186) is provided in the base body (122) through which the screw part (184) can be handled.