DE102013214151B4 - Set-up element, machine bed and machine tool - Google Patents

Abstract

According to one embodiment of the invention, an erection element (1) is provided which has a first conical-shaped element (2) which can be connected to a machine bed. The positioning element (1) also has a second conical-shaped element (4), which is arranged below the first element (2). The second element (4) is connected to a drive device (5), wherein by means of the drive device (5) the second element (4) is displaceable relative to the first element (2) along a first direction so that a tapered end of the second Element (4) on a common end of the first element (2) moves, while a bottom (8) of the first element (2) on an upper surface (9) of the second element (4) rests. By moving the second element with respect to the first element, an operative connection is created between the upper side of the second element and the lower side of the first element such that a distance (A) between the upper side (10) of the first element and the lower side (11 ) of the second element increases.

Description

The invention relates to an erection element, a machine bed and a machine tool.

Machine tools usually have three or more mounting elements which are arranged on an underside of the machine bed of the machine tool. If the machine tool is set up on the floor of a workshop, the entire weight of the machine tool rests on the erection elements, since these represent the only load-bearing connection elements between the machine bed and the floor.

GB 2 011 350 A shows a hydrostatic adjusting device, especially for adjustments under load, wherein the device comprises at least one wedge for the dissolution of a force, a pair of support members having sliding surfaces, with which the wedge is in contact via a fluid working medium, which is supplied under pressure and at least one adjustment member connected to the wedge to form a load chain. At least one support element and the end of the load chain opposite the wedge are fixed to each other at a predetermined distance.

DE 44 29 813 A1 shows a leveling shoe with a base plate, a cover plate and a wedge disposed therebetween, by means of a rotatably and axially immovably mounted horizontal screw, on which engaging in the base plate and the cover plate, against these in the vertical direction freely vreschiebliches and in the direction of Screw is screwed into this fixed anchoring member, more or less deep between the base plate and cover plate is inserted, so that the vertical distance between the base plate and cover plate is thereby changed, the screw in the wedge in the region of its head-side end and in the region of its opposite free end rotatable is stored.

DD 2 80 716 A1 shows a device for angle-adjustable alignment of parts in precision engineering and microelectronics and for use on machine tools, two plates bearing points by rolling elements and an expanding mandrel with slotted expansion sleeve and are secured together by compression springs. A nut is connected via differential thread with a spindle whose slider acts as wedge gear in the expansion sleeve. By turning the nut, a lowering or raising of the top plate in the region of the expansion sleeve is achieved.

DE 102 29 823 A1 shows a method for determining at least one coordinate of a structure in the measurement volume of a coordinate measuring machine mounted on variable tilt supports, comprising the steps of: detecting a measured value for the at least one coordinate, detecting a value for the inclination of the coordinate measuring machine. DE 102 29 823 A1 includes, as a further step, a correction of the measured value for the at least one coordinate as a function of the detected value for the inclination of the coordinate measuring machine.

The object underlying the invention is to provide a set-up with which a fast and permanent height adjustment of a machine bed of a machine tool is possible.

To solve the problem, the invention was a set-up according to claim 1, machine beds according to claims 10 and 11 and a machine tool according to claim 21 ready. Advantageous embodiments and developments of the inventive concept can be found in the subclaims.

According to one embodiment of the invention, a positioning element for use in a machine tool is provided, which has a first conical-shaped element that can be connected to a machine bed of the machine tool. The positioning element further comprises a second conical-shaped element ("wedge shoe"), which is arranged below the first element. The second element is connected to a drive device, wherein by means of the drive device, the second element is displaceable relative to the first element along a first direction so that a tapered end of the second element moves toward a common end of the first element, while a bottom of the first Elements rests on an upper side of the second element. By moving the second element relative to the first element, an operative connection is created between the upper side of the second element and the lower side of the first element such that a distance between the upper side of the first element and the lower side of the second element increases.

By using a drive device can be dispensed with a manual adjustment of the positioning, which is time-consuming. Thus, a quick adjustment of the positioning is guaranteed. Furthermore, due to the construction of the positioning element, a high rigidity of the positioning element is ensured, which ensures that the machine bed of the machine tool does not permanently deform even when strong oscillations or vibrations occur.

The second element is so by means of the drive direction along a second, opposite to the first direction opposite to the direction slidable first element, that the tapered end of the second element moves towards a tapered end of the first element, and a distance between the upper side of the first element and the underside of the second element decreases.

In other words, assuming that the first direction is the X-direction formed parallel to the ground, moving the second element along the first direction causes "expansion" of the positioning member in the Z-direction perpendicular to the X-direction. If, however, the second element is displaced along the second direction, the expansion of the positioning element in the Z direction is reduced. In this way, the machine bed can be raised and lowered relative to the ground in the Z direction.

The operative connection between the top of the second member and the bottom of the first member is a self-locking operative connection which causes a displacement of the second member along the second direction to be opposed by a frictional force when a compressive force is applied from the bottom of the first member to the top of the first member second element is applied, such that a displacement of the second element along the second direction is omitted, as long as the pressing force is below a certain threshold value. In other words, the second element "locks" in a relative position with respect to the first element as long as the compressive force exerted by the machine bed on the first element on the top of the second element is below a certain threshold. If the compressive force of the machine bed is below this threshold, then force must be actively applied to move the second element along the second direction. Advantage of a self-locking operative connection is that a relative position of the second element with respect to the first element even with a variation of the force exerted by the machine bed on the top of the second element compressive force can be kept constant with little effort by the drive means, whereby the height adjustment of the machine bed with respect of the soil can be kept permanently constant by means of the positioning element.

The self-locking operative connection (frictional force) between the upper side of the second element and the lower side of the first element can be achieved, for example, by friction coefficients of the upper side of the second element and the lower side of the first element and / or cone angle of the first element and the second element , which lie directly on each other, be chosen accordingly. The cone angle of the first element determines how strongly the first element tapers from its propagated end towards the tapered end. Similarly, the cone angle of the second element determines how much the second element tapers from its propagated end towards the tapered end.

The drive device may be connected, for example, with the common end of the second element. The drive device can be any drive device, for example an electric, hydraulic or pneumatic drive device.

The first element may be made of steel, for example. The advantage here is that the first element thereby has a high rigidity. Alternatively, other materials may be used. At least the upper region of the second element can be formed, for example, from gray cast iron. The combination of the materials steel for the first element and cast iron for the second element offers the advantage that a good self-locking effect between the bottom of the first element and the top of the second element can be achieved.

The force with which the drive device moves the second element in the first direction or in the second direction is advantageously infinitely adjustable. Thus, the extension of the set-up, that is, the height adjustment of the positioning, by means of appropriate force adjustment is infinitely adjustable.

Advantageously, the positioning element has a U-shaped third element, wherein a lower part of the third element is arranged below the second element. Upper ends or end portions of the third element are opposite side walls of the first element. The third element is movable relative to the first element. As the second member is moved in the first direction, a relative distance between the bottom of the third member and the bottom of the first member is increased. The third element serves as a guide which prevents the second element, when displaced along the first or second direction, from being moved in a direction which is perpendicular to the first / second direction and lies in a plane in which also the first / second direction runs. The third element thus adapts to the expansion of the positioning element.

Advantageously, each of the upper ends of the third element has an elongate recess, each of which faces one of the side walls of the first element, with a respective pin attached to respective side walls opposite the recesses of the first element. Each pin engages in one of the recesses, wherein upon moving the second member along the first direction, the third member is moved away from the first member such that the pins in the recesses slide toward upper ends of the recesses. Similarly, as the second member is moved along the second direction, the third member is moved toward the first member such that the pins in the recesses slide towards lower ends of the recesses (provided a corresponding compressive force acts from below on the third member). Thus, in a simple mechanical manner, a guide of the second element along the first or the second direction and an adjustment of the third element to the extension of the positioning element allows.

The invention further comprises a machine bed with at least one of the above-described installation elements.

According to one embodiment of the invention, a machine bed for a machine tool is provided, wherein the machine bed has a plurality of set-up elements which are provided on an underside of the machine bed. The machine bed has first set-up elements whose relative orientation with respect to the underside of the machine bed is fixed during operation of the machine tool. This means, in particular, that the relative positions (distances) of the ends of the first set-up elements (adjustment position) facing away from the underside of the machine bed with respect to the underside of the machine bed are immutable during operation of the machine tool. The first set-up elements allow a defined height adjustment of the machine bed with respect to the ground due to their static inherent rigidity and the rigid attachment to the machine bed during operation of the machine tool. Furthermore, the machine bed second Aufstellelemente the embodiments described above, which are adjustable in height, for example, infinitely adjustable in height, are configured. This means that their relative orientation with respect to the underside of the machine bed is changeable. This means, in particular, that the relative positions (distances) of the ends of the second set-up elements (adjustment position) facing away from the underside of the machine bed are adjustable with respect to the underside of the machine bed, for example infinitely adjustable. The height adjustment of the second set-up can be done in particular during operation of the machine tool. D. h., The second erection elements may be configured so that they are moved during the individual steps of the machine tool such as milling, drilling or moving a carriage, and / or before, after or between respective steps. The advantage of this embodiment is that the installation of the machine bed during operation of the machine tool can be optimized for the respective operating state. The second set-up can also, as far as appropriate, be moved outside the operation of the machine tool.

In order to stabilize the machine bed, the second set-up elements are designed such that between a first state in which the ends of the second set-up elements do not touch a floor located below the machine bed, and a second state in which the ends of the second set-up elements touch the ground, can be moved. For example, the second set-up elements can be moved relative to the underside of the machine bed in such a way that a pressure which the second set-up elements exert on the ground in the second state causes no or only negligible deformation or tensioning of the machine bed. The ends of the second set-up elements need not necessarily touch the ground in the second state, it is also possible, depending on the application, to move the ends of the second set-up elements with respect to the bottom such that in the second state a small gap (smaller than in the first state) between the ends of the second erection elements and the ground. This gap can be chosen so that sit at low vibrations of the machine bed, the ends of the second erection elements on the ground and thus at least slightly stabilizing effects are effective. This ensures that the method of the second erection elements from the first state to the second state, that is to say when adjusting the second set-up elements, has no disadvantageous effects on the machine bed. If the second set-up elements are in the second state, they can be "clamped" (locked in this position), i. H. a force that would be applied from the ground to the second set-up elements would be transmitted more strongly to the machine bed compared to the second state. In this way, it is possible to "bring the second set-up elements" already "in position" "preventive", and then to develop their effect as needed within a very small time interval selectively (to "clamp"). This allows a quick response to undesirable effects such as vibrations of the machine bed, that is, unexpected, spontaneously occurring vibrations can be compensated directly, although the second set-up elements are not initially "armed" (locked).

During the operation of the machine tool, the second set-up elements can be adjusted in height so that when the machine tool is loaded with a load or when the load on the machine tool is being moved, a local deformation occurs of the machine bed that would be caused by the loading / process is prevented or reduced. Alternatively or additionally, during the operation of the machine tool, the second set-up elements can be adjusted in height so that vibrations of the machine bed, which are generated by the operation of the machine tool, are damped. Alternatively or additionally, during operation of the machine tool, the second set-up elements can be adjusted in height so that the machine bed is specifically locally deformed. Alternatively or additionally, during operation of the machine tool, the second set-up elements may be adjustable in height in such a way that deformations of the machine bed due to a temporal change in the height profile of the floor or due to unevenness of the floor are avoided or reduced. For example, during operation of the machine tool, the second set-up elements can be adjusted in height so that a) they are brought into operative connection with the ground below the machine bed, and b) the active compound is dissolved again after a certain period of time, wherein steps a) and b) be repeated as many times as possible so that deformations of the machine bed due to a change in the height profile of the soil over time or compensated be reduced. The method of the second set-up can also be done in these embodiments, where appropriate, outside the operation of the machine tool. The activation of the second set-up elements can be designed such that each of the second set-up elements can be controlled individually (ie independently of the other set-up elements at the height of the operation and in the force with which the set-up elements are moved). "Active connection" in this context means that the second set-up elements are in contact with the ground and exert a force on them (and vice versa), at least when the machine bed and the floor move relative to each other.

Preferably, during operation of the machine tool, the second set-up elements can be configured to be height-adjustable automatically by means of a drive unit (ie the drive unit does not have to be operated manually). By way of example, the machine bed can have sensors by means of which operating parameter values such as deformations or vibrations of the machine bed can be detected, the control unit determining the second set-up elements as a function of detected operating parameter values (which are determined by the sensors or active process observers), such as vibration velocity or geometric measured variables (eg. geometric dimensions of a component) automatically height-adjusted. Alternatively, the drive unit can also be operated manually. For example, the drive unit may have a user interface in which a certain height adjustment of the second set-up elements can be activated during operation of the machine tool at the push of a button.

The machine bed or the machine tool can have a memory unit in which assignment data are stored, which assign operating states of the machine tool respective individual settings (height / force) of the second set-up elements, wherein in a certain operating state of the machine tool the drive unit adjusts the second set-up elements according to the assignment data , The current or future operating state can be detected using (passive) sensors such. As vibration or velocity sensors, or using active, intelligent process observers such. As cameras that determine the geometry of a workpiece and judge. The advantage of this embodiment is that the machine tool can access the effect of additional set-up elements (the second set-up elements) as needed. If, for example, a work step in which the machine bed is not or hardly vibrated is switched in one step, in which the machine bed is set in strong oscillations, a selection of second set-up elements can thus be selectively adjusted in their relative orientation with respect to the underside of the machine Machine bed procedures are that the machine bed is additionally stabilized by the second set-up.

The transition from the first state to the second state can, for example, be effected by using a positioning element according to one of the above-described embodiments, by causing the second element along the first direction only with a very small force by means of the driving device, which is too weak to to cause lifting of the first element in the direction of the underside of the machine bed as soon as the second setting element touches the ground. This ensures that the method of the second erection elements from the first state to the second state, that is to say when adjusting the second set-up elements, has no disadvantageous effects on the machine bed. Starting from this state, the clamping (locking), for example, be effected by the second element is moved a little further along the first direction or the force of displacement is increased (which optionally also the self-locking effect is activated or increased and thus for the clamping / locking can be used). D. h., The second erection elements may be configured so that they can be converted from the second state to a third state in which, compared to second state, the force is increased, with which the drive device shifts the second element in the first direction. Increasing this force causes the lower ends of the second set-up elements to be pushed against the ground with greater force (locking / clamping). If alternatively second set-up elements are used (see below) which use hydraulic cylinders, then the locking / clamping takes place by closing a corresponding valve, with which pressure fluid is supplied. If the force with which the lower ends of the second set-up elements are pushed against the ground, strong enough, the first elements are raised towards the bottom of the machine bed, and thus also raised the machine bed (targeted deformation of the machine bed).

This makes it possible to divide the process of the method of the second erection elements into two steps: In a first step, the second set-up elements are transferred to the second state so that they just do not touch the ground or touch the ground, but between the first element and There is still a certain amount of play in the second element. Thus, no or only a slight stabilization of the machine bed takes place. The stabilizing effect of the machine bed unfolds fully only when the second element is moved further (possibly with increased force) in the first direction, since then the second set-up touch the ground or the game between the first element and the second element disappears. Thus, it is possible to "preemptively" bring the second set-up elements "in position", and then to unfold their effect as needed within a very short time interval selectively by the second element is moved a little further along the first direction or the force of displacement is increased.

Advantageously, the machine tool / machine bed can be provided with a control device which controls the method of the second set-up elements. For example, the control device can be configured such that the second set-up elements are transferred from the third state to the first state or the second state at specific time intervals, and, starting from the first or second state, back to the third state. In other words: By means of the control device, the height position and the force of the second set-up elements can be adjusted as needed, d. H. be increased or decreased. This makes it possible to automatically ensure at regular intervals that the second set-up elements still touch the ground, d. H. To prevent that due to deformations of the soil or in the machine bed, the second set-up elements no longer touch the ground. In order to determine whether the second set-up elements have already been successfully transferred from the first state to the second state, for example, a suitable sensor may be provided on the second set-up elements or elsewhere.

The number of first set-up elements can be three. Thus, the advantages of the so-called three-point installation are guaranteed. By three-point installation is meant, for example, that two of the first set-up elements are located at a first end of the machine bed and one of the first set-up elements is arranged at a second end of the machine bed between (eg, but not necessarily centered) the other two set-up elements is. An imaginary connection of the first set-up elements would therefore result in a triangle.

According to one embodiment of the invention, it is possible to switch between the states described below: In a first state, the second set-up elements can be moved so that no contact or contact, but no significant operative connection between the second set-up elements and the floor, also not at Load on the machine bed ("completely disengaged"). In this state, which may be the normal state, then only the first set-up elements have an operative connection with the ground, which can have a 3-point geometry, for example. Due to the 3-point geometry, in the first state, the machine tool can operate in precision mode. In a second state, the second set-up elements can be moved so that in the normal state of the machine bed no significant force is exerted by the second set-up elements on the machine bed ("engaged", but "bias" = + - zero), but under load of the machine bed the machine bed would be supported by the second set-up elements (by their inherent rigidity). In a third state, the second set-up elements can be moved so that a small force is exerted by the second set-up elements on the machine bed (("engaged", "preload"> zero), but the force is too low to a deformation In this state, however, there are slight local deformations of the machine bed in the region of the second set-up elements, which is the machining accuracy of the machine tool as a whole In a fourth state, the second set-up elements can be moved in such a way that a high force is exerted on the machine bed by the second set-up elements ("pretensioning">> Zero), the force being sufficient to cause deformation of the machine bed, which affects the machining accuracy of the machine tool as a whole. The machine bed can thus be deliberately "straddled" or "directed" in this state. This can be useful, for example, when the machine bed or the machine tool is subjected to a high load in order to compensate for the deformation of the machine bed normally caused by the load in the first place, or to achieve a specific damping characteristic.

The second erection elements of the machine bed can generally be any devices which have self-locking mechanisms and / or force transmission mechanisms and / or damping mechanisms in order to reinforce / stabilize the erection effect. In particular, the second set-up elements of the machine bed can be designed in the same way as the set-up elements described in the preceding embodiments. Alternatively or additionally can be provided as a second set-up elements, the static inherent rigidity is adjustable. Such set-up elements may be formed, for example, as a hydraulic cylinder, each having a movable relative to the underside of the machine bed piston. The method of the piston can be effected, for example, by pressurizing the piston with a pressurized fluid. For this purpose, the hydraulic cylinder, for example, have a pressurized fluid supply line via which the pressure fluid can be fed to the piston. Advantageously, the pressure fluid supply line to a valve, via which the pressure fluid supply line can be closed or opened. In this case, the static inherent rigidity of the positioning elements can be achieved by opening (low inherent rigidity) and closing (high intrinsic rigidity) of the valve ("clamping").

If a machine bed has different types of second set-up elements, the different second set-up elements can be selectively activated as required. For example, damping of the machine bed can be activated as required by selectively activating damping mounting elements, whereas selective activation of "rigid" mounting elements can be used specifically for purposes which require a very high inherent rigidity of the mounting elements, for example for straightening or deforming the machine bed.

The invention furthermore has a machine tool (of any type, such as, for example, a milling machine, lathe, grinding machine, etc.) with a machine bed according to the invention. Such a machine tool in particular allows the following advantages: an increase in the cutting power in heavy-duty cutting; an increase in machine accuracy, as the machine bed is better supported when moving the axes; a general increase in productivity and performance due to increased drive dynamics (controller gains, jerk); and a better surface quality by vibration reduction with the use of damping Aufstellelementen.

The invention will be explained in more detail below with reference to the figures in an exemplary embodiment. Show it:

1 a schematic perspective view of a positioning element according to an embodiment of the invention in a state A;

2 a schematic perspective view of the in 1 shown Aufstellelements in a state B;

3 a schematic perspective view of the in 1 shown positioning element from a different perspective;

4 a schematic perspective view of the in 1 shown Aufstellelements from a still different perspective;

5 a cross-sectional view of the in 1 shown Aufstellelements;

6 a schematic perspective view of a machine bed of a conventional machine tool;

7 a schematic perspective view of a machine bed of a machine tool according to an embodiment of the invention;

8th a schematic cross-sectional view of different states second set-up in a machine bed of a machine tool according to an embodiment of the invention; and

9 shows a schematic representation of an optionally deployable positioning element according to an embodiment of the invention.

In the figures, identical or corresponding areas, components or component groups are identified by the same reference numerals. The drawings are schematic in nature, d. H. not necessarily true to scale.

1 shows a positioning element 1 according to an embodiment of the invention. The positioning element 1 has a first conical-shaped element 2 on, that via a fastening device 3 with a machine bed (not shown) of a machine tool is connectable. Furthermore, the set-up element 1 a second conical-shaped element 4 on, that is below the first element 2 is arranged. Further, a drive device 5 provided with the second element 4 connected is. By means of the drive device 5 is the second element 4 opposite the first element 2 slidable along a first direction (X-direction) such that there is a tapered end 6 of the second element 4 to a common ending 7 of the first element 2 moved to while a bottom 8th of the first element 2 on a top 9 of the second element 4 rests. In this way is between the top 9 of the second element 4 and the bottom 8th of the first element 2 produces an operative connection, such that there is a distance A between an upper side 10 of the first element 2 and a bottom 11 of the second element 4 increased. D. h., By moving the second element 4 along the first direction becomes the first element 2 pushed away upwards in the Z-direction.

In 1 is shown a state in which the second element 4 just in operative connection with the first element 2 has entered. That is, the second element would be 4 by means of the drive device 5 in a direction opposite to the first direction, the second direction (negative X direction) would be moved between the top 9 of the second element 4 and the bottom 8th of the first element 2 a gap (game) arise. In 2 is a state of in 1 shown positioning element 1 shown after the second element 4 opposite the first element 2 further along the first direction (X direction) has been moved. Regarding the in 1 shown state of the positioning is a distance A 'between the top 10 of the first element 2 and the bottom 11 of the second element 4 enlarged ("expansion" of the positioning element in the Z direction). The increase of the distance A in A 'results from the fact that by the displacement of the second element 4 along the first direction X, a lifting (shifting) of the first element 2 along the Z-direction is effected.

Order from the in 2 shown state of the positioning element 1 in the in 1 change state shown, the drive device 5 so driven that the second element 4 opposite the first element 2 along the second direction (negative X direction) is shifted. For this purpose, the drive device exercises 5 on the second element 4 a tensile force. While moving the second element 4 along the second direction, the distance A 'decreases continuously until the in 1 shown distance A is taken.

The between the top 9 of the second element 4 and the bottom 8th of the first element 2 existing active compound is preferably a self-locking operative connection (frictional force), which causes a displacement of the second element 4 along the second direction is opposed to a frictional force that is so great that a displacement of the second element 4 is omitted along the second direction, inasmuch as a compressive force, via the fastening element 3 on top 10 of the second element 2 and above it on the top 9 of the second element 4 is applied, is below a certain threshold, and thus a traction (if any) of the drive means 5 with which the second element 4 in the second direction is below a certain threshold. In other words, the frictional force at the interface between the first element 2 and the second element 4 caused by the pressure force of the fastener 3 on the first element 2 is generated, prevents the second element 4 along the second direction back to the drive device 5 is shifted, even if the drive device 5 such a displacement does not oppose any counteracting force. The frictional force, which is necessary to achieve the self-locking, by appropriate design of the top 9 of the second element 4 as well as the bottom 8th of the first element 2 be achieved, ie by appropriate choice of the friction coefficient of the top 9 and the bottom B. Further, the frictional force by a cone angle α of the first element 2 and a cone angle β of the second element 4 to be influenced.

Depending on the application, the materials of the first element 2 and the second element 4 be selected suitable. Should a high rigidity of the positioning element 1 be assured, so can the first element 2 as well as the second element 4 be made of correspondingly hard materials.

For example, the first element 2 made of steel and the second element 4 (at least its upper part) are made of gray cast iron.

As in 1 and 2 shown is the drive device 5 with a common end of the second element 4 connected. However, it is also conceivable, the drive device 5 with the tapered end 6 of the second element 4 to connect, in so far thereby the height adjustment of the first element 2 is not affected.

In 3 and 4 is that in 1 and 2 shown Aufstellelement 1 to see from further perspective views. Clearly visible in 3 and 4 a U-shaped third element 13 in that it is designed or arranged such that a lower part 14 of the third element 13 below the second element 4 is arranged, and upper end portions 15 of the third element 13 sidewalls 16 of the first element 2 are opposite. When moving the second element 4 in the first direction becomes a relative distance B between the lower part 14 of the third element 13 and the bottom 8th of the first element 2 increased.

Each end section 15 of the third element 13 has an elongated recess 17 on, each one of the side walls 16 of the first element 2 are opposite. The elongated recesses 17 are aligned parallel to the Z direction. On the side walls 16 of the first element 2 is each a pen 18 attached, with each pen 18 in one of the recesses 17 engages, and wherein when moving the second element 4 in the X direction, the third element 13 relative to the first element 2 removed, leaving the pins 18 towards the top ends of the recesses 17 slide, ie in the direction of those ends of the recesses 17 that of the top 10 of the second element 2 are facing. The tensions 17 thus act as a guide means for controlled movement of the third element 13 along the Z direction and opposite. Once the pins 18 at the upper ends of the extension 17 can strike, the third element 13 not be moved further in the direction opposite to the Z direction. On the other hand, if the pins 18 at a lower end of the recesses 17 can strike, the third element 13 not be moved further in the Z direction. The third element 13 prevents the second element from moving along the first direction in a direction perpendicular thereto (Y-direction).

In 5 By way of example, a selection of parameters is shown with which the positioning element 1 can be effectively operated in self-locking. It is assumed that the third element 13 made of steel, the first element 2 also made of steel, and the second element 4 made of gray cast iron. Furthermore, it is assumed that the static friction coefficient μHaft of steel on gray cast iron is between 0.18 and 0.24, and the sliding friction coefficient μGleit of steel on gray cast iron is between 0.17 and 0.24. It is assumed that the bottom 8th of the first element 2 as well as the top 9 of the second element 4 are such that these friction coefficients are met. From the above assumptions, it can be calculated that there is a self-locking effect between the first element 2 and the second element 4 from a cone angle α of less than 9.65 degrees (arctan 0.17). In this embodiment, to ensure that a self-locking effect occurs, assume a cone angle α of 6 degrees. Furthermore, it is assumed that the drive device 5 a hydraulically or pneumatically operated cylinder 19 having a stroke of 40 mm and a piston diameter of 25 mm. As operating pressure of the drive device 5 be 115 bar accepted.

From the above assumptions, the following balance of forces results: The maximum compressive force F cylinder, that of the cylinder 19 on the second element 4 is exercised to shift it along the first direction is 5645 Newton. The tensile force of the cylinder 19 with which the second element 4 back to the drive device 5 is pulled along the second direction, is a maximum of 3333 Newton. It follows that a maximum vertical force F Vertical, by moving the second element 4 on the first element 2 is exercised at 8067 Newton. The force F self-locking resulting from the self-locking effect is 2098 Newtons. The vertical hub S, over which the first element 2 along the Z-axis is 4.18 mm. The above calculation is merely exemplary.

6 shows a conventional machine bed 31 , at the bottom 32 several installation elements 33 are provided. The erection elements 33 are arranged in a three-point arrangement: a first set-up element 31 is located centrally with respect to a connecting line between a second and a third positioning element 32 . 33 , wherein the first raising element 31 at a first end 34 of the machine bed 31 , and the second and third positioning element 32 . 33 at a second end 35 of the machine bed 31 is arranged. In the 6 shown geometry of the three-point lineup 33 is merely exemplary and not mandatory; For example, the first installation element needs 31 not necessarily centered with respect to the connecting line between the second and the third positioning element 32 . 33 be arranged. The erection elements 33 are constant in their rigidity. The relative orientation of the positioning elements 33 with respect to the bottom 32 of the machine bed 31 (ie the relative position of the machine bed 31 groundbreaking ends of the erection elements 33 with respect to the bottom 32 of the machine bed 31 ) can be changed manually, for example by means of screws, in this embodiment, the relative position of the erection elements 33 is changeable with respect to a Z-direction.

The three-point setup has the advantage that the machine bed 31 even when setting up on uneven ground 37 not or only slightly braced or deformed. When using the three-point setup thus the working accuracy depends on the machine bed 31 arranged machine tool or only to a very limited extent by the flatness of the soil 37 from. This makes it possible to spend a machine tool with three-point installation from one location to another location without a new adjustment of the erection would be absolutely necessary. An advantage of this is in particular that the flatness of the soil 37 no or only low requirements must be made in order to ensure a sufficient working accuracy or long-term stability of the machine tool.

A disadvantage of the in 6 shown machine bed 31 is that the erection elements 33 Vibrations in the machine bed 31 can only compensate inadequately.

7 shows a machine bed 31 ' according to a first embodiment of the invention, which eliminates this disadvantage. The machine bed 31 ' corresponds in its construction to the in 6 shown machine bed 31 , In addition, however, are second set-up 33 ' provided with respect to the bottom 32 of the machine bed 31 are designed movable in height, ie, the relative positions of the machine bed 31 groundbreaking ends 40 the second erection elements 33 ' with respect to the bottom 32 of the machine bed 31 are by moving the second set-up 33 ' changeable. The erection elements 33 ' are movable in this embodiment with respect to the Z-axis, but the invention is not limited thereto. For example, it would also be possible to use the second set-up elements 33 ' to move with respect to an axis which is inclined at an arbitrary angle with respect to the Z-axis. The second set-up elements 33 ' may advantageously be in 1 to 5 shown installation elements 1 However, the invention is not limited thereto.

The second set-up elements 33 ' can, as in 37 shown at the end 40 with an elastic layer 36 be provided, ie with a layer of a material whose elasticity, compared with the other components of the second set-up 33 ' , is increased.

8th shows a schematic cross-sectional view of in 7 shown second erection elements 33 ' in different states according to an embodiment of the invention. In a first state A, there are the second set-up elements 33 ' in a position relative to the Z-axis, in which it is below the machine bed 31 located ground 37 do not touch. The second set-up elements 33 ' are convertible from the first state A to a second state B, in which these the ground 37 touch. The second set-up elements 33 ' are in this case movable so that a pressure, the second set-up 33 ' in the second state B on the ground 37 exercise, no or only negligible deformation / distortion of the machine bed 31 causes. In other words, only a slight pressure on the second element 4 the second erection elements 3 ' along the second direction (negative X direction) would be enough to make the second element 4 in the direction of the drive device 5 to press. The second set-up elements 33 ' are further from the second state B in a third state C can be converted, in which, compared to the second state B, on the second element 4 by means of the drive device 5 applied force is increased in the direction of the X direction. In other words, in the third state C, the pressure would be in the second state B for pushing back the second element 4 in the direction of the drive device 5 sufficient, not enough. In the second state B, the second installation elements 33 ' a weak support of the machine bed 31 , in the third state C a strong support.

The second set-up elements 33 ' are switchable in any manner between the states A, B and C back and forth. Thus, for example, at regular intervals from the third state C in the first state A are returned by the second set-up elements 33 ' in the direction of the machine bed 31 be moved, then, starting from the first state A, again in the second state B and from this to the third state C to be transferred. In this way, for example, in the meantime resulting bumps in soil 37 or deformations in the machine bed 31 leading to unwanted gaps between the ends 40 the second erection elements 33 ' and the floor 37 lead, be eliminated, thus ensuring that at any time a support of the machine bed 31 done by the second set-up. Conversely, as a result, can also arise in the meantime arches of the soil 37 to the machine bed 31 ' leading to deformation / distortion of the machine bed 31 ' lead, be balanced by the ends 40 the second erection elements 33 ' a little further to the machine bed 31 ' be drawn.

As has become clear from the foregoing description, embodiments of the invention make it possible to retain the advantage of the three-point installation by continuing to place the machine tool on three first set-up elements 33 stands. In addition, however, supportive installation elements 33 ' on the machine bed 31 ' appropriate. The specific design of the supporting installation elements 33 ' is not on the in 1 to 5 limited embodiments shown.

9 shows a schematic representation of an optionally usable positioning element 93 according to an embodiment of the invention. In this embodiment, the positioning element 93 as a hydraulic cylinder 98 designed, the one relatively to the bottom 2 of the machine bed 91 movable piston 99 having. The piston 99 is moved, in which this with a pressurized fluid 910 is applied to the hydraulic cylinder 98 via a pressure fluid line 911 is supplied. In the pressure fluid line 911 is a valve 912 provided, via which the pressure fluid line 911 can be opened or closed. Will the positioning element 93 transferred from a first state A to a second state B, the hydraulic cylinder 98 over the pressure fluid line 911 pressure fluid 910 fed, causing the piston 99 in the direction of the ground 97 emotional. The pressure with which the pressurized fluid 910 the piston 99 is applied in state B is so low that the lower end 915 of the piston 99 when putting on the ground 97 neither the ground 97 still the machine bed 1 deformed, ie that of the piston 99 on the hydraulic cylinder 98 applied force is too low to deformation / strain in the machine bed 91 at which the hydraulic cylinder 98 is fixed to evoke. Will the positioning element 93 transferred from the second state B in a third state C, the valve 12 closed, bringing that into the hydraulic cylinder 98 located pressure fluid 910 no longer via the pressure fluid line 911 from the hydraulic cylinder 98 can move out. This allows the piston 99 even when subjected to a high force on the ends 915 only to a small extent from the ground 97 in the direction of the hydraulic cylinder 98 be moved, ie the rigidity of the hydraulic cylinder 98 is increased from the second state B. To return from state C back to state B or A, the valve can 913 be opened, which is closed in the states A and B, which pressurized fluid from the hydraulic cylinder 98 over the pressure fluid line 914 can be dissipated. Then the valve can 913 closed and the valve 912 be opened.

The embodiments according to the invention are based on the following considerations of the inventors: Experiments with machines with more than three set-up points have shown that the working accuracy of a machine tool is reduced if the preload of the set-up elements is not adjusted exactly or if subsidence phenomena occur in the floor or in the set-up elements comes. On the other hand, an installation of the machine tool at more than three set-up points (i.e., the use of more than three set-up elements, so-called multipoint installation) has the advantage that the machine bed is better supported, whereby vibrations of the machine bed can be better damped or completely suppressed. In particular, in heavy cutting the multipoint installation has great advantages, since chatter vibrations can form only to a small extent.

In order to combine the advantages of the three-point installation and the multipoint installation, the combination of three rigid and several passive elastic erection elements was examined. It turns out, however, that even elastic erection elements must be made with a great force if they are to have a sufficient supporting effect on the machine bed. As a result, the machine bed is also deformed by elastic mounting elements. The conflict with the use of additional elastic erection elements is therefore that they must be stiff on the one hand in order to support the machine bed sufficiently, but on the other hand they must have sufficient elasticity, so subsidence in the ground or an incorrect setting of the rigid erection not Change forces on the machine bed.

Furthermore, the use of additional pure damping elements without static inherent rigidity was examined by the inventors, such. B. hydraulic cylinder. Such elements yield when the floor is lowered, but do not exert any static forces on the machine bed and therefore can not deform it. Their supportive effect they develop only by the fact that these occurring vibrations oppose damping forces. The disadvantage of using purely damping elements is that their ends must be firmly connected to the floor and the machine bed so that they can develop their vibration-damping effect. An attachment to the ground by gluing or pegging is always associated with damage to the foundation.

The conflict outlined above is due to the in 1 - 5 embodiment shown canceled: When extending the piston 19 in the X direction can be a force acting on the second element 4 is exercised so low that this machine bed 31 ' not deformed. If necessary, the through the piston 19 on the machine bed 31 ' applied force can be increased, so that the machine bed 1' is well supported.

• – Das Maschinenbett 31' kann nicht durch eine falsche Einstellung der ersten Aufstellelemente 33 verformt werden;
• – Es ist kein Ausrichten des Maschinenbetts 31' notwendig, da es zunächst immer auf den drei festen, starren ersten Aufstellelementen 33 steht und die zweiten Aufstellelemente 33' erst anschließend mit geringer Kraft ausgefahren werden können. Auch beim Versetzen der Werkzeugmaschine bleibt die Arbeitsgenauigkeit der Werkzeugmaschine ohne erneutes Ausrichten der starren ersten Aufstellelementen 33 erhalten;
• – An die Genauigkeit und das Setzverhalten des Fundaments (des Bodens 37 sowie der ersten Aufstellelementen 33) werden keine besonderen Anforderungen gestellt;
• – Die zweiten Aufstellelemente 33' können nach jedem Bearbeitungsschritt oder zwischen den Bearbeitungsschritten nachgespannt werden, so dass die Aufstellung auch langfristig stabil bleibt;
• – Es ist keine dauerhafte Befestigung der zweiten Aufstellelemente am Boden 37 notwendig.
• – Eine optionale schwingungsdämpfende Schicht 36 am Ende 40 des zweiten Aufstellelements 33' verringert zwar die Steifigkeit des Aufstellelements 33', die höhere Dämpfung wirkt sich aber teilweise besser auf das Zerspanverhalten der Werkzeugmaschine aus. Zudem geht die Vorspannung des zweiten Aufstellelements 33' nicht so leicht verloren, wenn der Aufstellfuß, d. h. das Ende 40 des Aufstellelements 33', eine gewisse Elastizität besitzt.

Compared to the multipoint constellations described above, this arrangement has many advantages:

• - The machine bed 31 ' can not be due to an incorrect setting of the first set-up elements 33 be deformed;
• - There is no alignment of the machine bed 31 ' necessary, since it always first on the three fixed, rigid first set-up elements 33 stands and the second set-up elements 33 ' can then be extended with little force. Even when moving the machine tool, the working accuracy of the machine tool remains without re-aligning the rigid first erection elements 33 receive;
• - To the accuracy and setting behavior of the foundation (the soil 37 as well as the first set-up elements 33 ) no special requirements are made;
• - The second set-up elements 33 ' can be re-tensioned after each processing step or between the processing steps so that the setup remains stable over the long term;
• - There is no permanent attachment of the second set-up elements on the ground 37 necessary.
• - An optional vibration damping layer 36 at the end 40 of the second set-up element 33 ' Although reduces the rigidity of the positioning element 33 ' However, the higher damping effect in part better on the Zerspanverhalten of the machine tool. In addition, the bias of the second set-up goes 33 ' not so easily lost when the foot, ie the end 40 of the erection element 33 ' , has a certain elasticity.

For large machines with more than 70 Set-up can be described in the preceding embodiments combination of three-point installation (three first set-up 33 ) and second erection elements 33 ' be used several times. Because the machine bed 31 However, machine tools of this size are no longer intrinsically rigid and have a very high rigidity of all set-up elements 33 . 33 ' advantageous.

By pressure variation (eg, based on the use of a calibration table), the geometry of the machine bed can be determined 31 z. B. set or hold at high loads spherical, this increases the geometric accuracy during processing. In general, it can be specified in a calibration table which processing steps / loads of the machine tool / machine bed activate the second set-up elements 33 ' requires, and to what extent (width of the passage of the second erection elements 33 ' and the power of the process). This functionality opens up the possibility of reducing the cross-section height of the machine bed 31 , which has a positive effect on the ergonomics and allows a reduction of the table height of the toolmashine. Also a mass reduction of the machine bed 31 and a reduction in the height of the machine bed 31 is conceivable. The low height and the compact dimensions of the installation elements 33 ' allow easy integration of the same in the machine bed 31 ,

Claims (21)

Set-up element ( 1 ), - with a first conical-shaped element ( 2 ), with a machine bed ( 31 ) is connectable, - with a second conical-shaped element ( 4 ), which is below the first element ( 2 ), and - with a drive device ( 5 ) connected to the second element ( 4 ), - wherein by means of the drive means ( 5 ) the second element ( 4 ) compared to the first element ( 2 ) is displaceable along a first direction so that a tapered end ( 6 ) of the second element ( 4 ) to a widened end ( 7 ) of the first element ( 2 ), while an underside ( 8th ) of the first element ( 2 ) on a top side ( 9 ) of the second element ( 4 ) rests, which between the top ( 9 ) of the second element ( 4 ) and the underside ( 8th ) of the first element ( 2 ) an active connection is produced, such that a distance (A) between the upper side ( 10 ) of the first element ( 2 ) and the underside ( 11 ) of the second element ( 4 ), the second element ( 4 ) by means of the drive device ( 5 ) along a second, opposite to the first direction so opposite the first element ( 2 ) is displaceable, that the tapered end ( 6 ) of the second element ( 4 ) on a tapered end of the first element ( 2 ), and between the underside ( 8th ) of the first element ( 2 ) and the top ( 9 ) of the second element ( 4 ) an active connection is produced, such that a distance (A) between the upper side ( 10 ) of the first element ( 2 ) and the underside ( 11 ) of the second element ( 4 ), and - wherein the operative connection between the top ( 9 ) of the second element ( 4 ) and the underside ( 8th ) of the first element ( 2 ) is a self-locking active compound which causes a displacement of the second element ( 2 ) is opposed to a frictional force along the second direction when a pressing force from the underside ( 8th ) of the first element ( 2 ) on the top ( 9 ) of the second element ( 4 ), such that a displacement of the second element ( 4 ) is omitted along the second direction as long as the compressive force is below a certain threshold. Set-up element ( 1 ) according to claim 1, characterized in that the self-locking operative connection between the upper side ( 9 ) of the second element ( 4 ) and the underside ( 8th ) of the first element ( 2 ) is achieved by frictional coefficients of the upper side ( 9 ) of the second element ( 4 ) and the underside ( 8th ) of the first element ( 2 ) and cone angle (α, β) of the first element ( 2 ) and the second element ( 4 ) are selected accordingly. Set-up element ( 1 ) according to one of claims 1 to 2, wherein the drive device ( 5 ) with the widened end ( 12 ) of the second element ( 4 ) connected is. Set-up element ( 1 ) according to one of claims 1 to 3, wherein the first element ( 2 ) consists at least partially of steel. Set-up element ( 1 ) according to one of claims 1 to 4, wherein the second element ( 4 ) consists at least partially of gray cast iron. Set-up element ( 1 ) according to one of claims 1 to 5, wherein the drive device ( 5 ) is an electrical, hydraulic or pneumatic device. Set-up element ( 9 ) according to one of claims 1 to 6, wherein a force with which the drive device ( 5 ) the second element ( 4 ) is moved in the first direction or in the second direction, is infinitely adjustable. Set-up element ( 1 ) according to one of claims 1 to 7, further comprising a U-shaped third element ( 13 ), with a lower part ( 14 ) of the third element ( 13 ) below the second element ( 4 ), and upper end portions ( 15 ) of the third element ( 13 ) Side walls ( 16 ) of the first element ( 2 ) and when moving the second element ( 4 ) in the first direction a relative distance (B) between the lower part ( 14 ) of the third element ( 13 ) and the underside ( 8th ) of the first element ( 2 ) is increased. Set-up element ( 1 ) according to claim 8, wherein each of the upper end sections ( 15 ) of the third element ( 13 ) a recess ( 17 ), each one of the side walls ( 16 ) of the first element ( 2 ) and on corresponding opposite side walls ( 16 ) of the first element ( 2 ) one pen each ( 18 ), each pen ( 18 ) in one of the recesses ( 17 ) and when moving the second element ( 4 ) the third element ( 13 ) so from the first element ( 2 ) is moved away, that the pins ( 18 ) in the recesses ( 17 ) towards upper ends of the recesses ( 17 ) slide. Machine bed, with at least one positioning element according to one of claims 1 to 9. Machine bed for a machine tool, which is attached to a lower side ( 2 ) a plurality of positioning elements ( 33 . 33 ' ), wherein first set-up elements ( 33 ) are provided whose relative orientation with respect to the underside ( 32 ) of the machine bed ( 31 ) is fixed during operation of the machine tool, wherein additional second set-up elements ( 33 ' ) are provided during operation of the machine tool with respect to the underside ( 32 ) of the machine bed ( 31 ' ) are infinitely adjustable in height, characterized in that the second set-up elements ( 33 ' ) are designed such that these between a first state in which the ends of the second set-up elements ( 33 ' ) one below the machine bed ( 31 ' ) ( 37 ) and a second state in which the ends of the second set-up elements ( 33 ' ) the ground ( 37 ), can be moved. Machine bed ( 31 ' ) according to claim 11, wherein the second set-up elements ( 33 ' ) are configured according to one of claims 1 to 9, or are Aufstellelemente whose static inherent rigidity is adjustable. Machine bed according to claim 11 or 12, wherein the second set-up elements ( 33 ' ) are so height-adjustable during operation of the machine tool that when loading the machine tool local deformation of the machine bed, which would be caused by the load is prevented or reduced. Machine bed according to one of claims 11 to 13, wherein the second set-up elements ( 33 ' ) are so height adjustable during operation of the machine tool that vibrations of the machine bed, which are generated by the operation of the machine tool, are damped. Machine bed according to one of claims 11 to 14, wherein the second set-up elements ( 33 ' ) are so height-adjustable during operation of the machine tool that the machine bed is specifically locally deformed. Machine bed according to one of claims 11 to 15, wherein the second set-up elements ( 33 ' ) are so height adjustable during operation of the machine tool that deformations of the machine bed due to a temporal change in the height profile of the soil or due to unevenness of the soil are avoided or reduced. Machine bed according to claim 16, wherein the second set-up elements ( 33 ' ) are adjusted in height during operation of the machine tool so that a) they are brought into operative connection with the ground below the machine bed, and b) the active compound is dissolved again after a certain period of time, wherein the steps a) and b) are repeated periodically, such that deformations of the machine bed due to a temporal change of the height profile of the soil are compensated or reduced. Machine bed according to one of claims 11 to 17, wherein the second set-up elements ( 33 ' ) during operation of the machine tool by means of a drive unit are automatically height adjustable. Machine bed according to claim 18, wherein the machine tool sensors or active observation devices by means of which operating parameter values such as deformations or vibrations of the machine bed are detectable, wherein the drive unit, the second set-up elements ( 33 ' ) is adjusted in height as a function of detected operating parameter values. Machine bed according to claim 18 or 19, with a storage unit in which allocation data are stored, the operating states of the machine tool respective settings of the second set-up elements ( 33 ' ), wherein in a certain operating state of the machine tool, the drive unit, the second set-up elements ( 33 ' ) height-adjusted according to the assignment data. Machine tool, with a machine bed ( 31 ' ) according to any one of claims 10 to 20.

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